#especially with LIME!!!!!!! mm m mm m m m.

[ricopop]

WOOAAOOW!!!!!!!!!!! i lovr OCTONAUTS!!!!!!!

[greatworldwar2]

• Hotchkiss H35

The Hotchkiss H35 or Char léger modèle 1935 H was a French cavalry tank developed prior to World War II. The Hotchkiss H35 was adopted in 1936 by the French Cavalry arm.

In 1926, it had been decided to provide armour support to the regular infantry divisions by creating autonomous tank battalions equipped with a light and cheap infantry tank, a char d'accompagnement. In 1933, the Hotchkiss company under its own initiative presented a plan to produce a design. This was made possible by the application of a new technology to produce cast steel sections to construct an entire hull. On June 30th, 1933, this proposal was approved by the Conseil Consultatif de l'Armement. On August 2nd, 1933 the specifications were issued: a weight of 6 long tons (6.1 t) and 30 mm (1.2 in) armour protection all around. Three prototypes were ordered from Hotchkiss, but the French industry as a whole was also invited to provide alternative proposals for a nouveau char léger. On January 18th, 1935, the first Hotchkiss prototype, not yet made of armour steel, was presented to the Commission d'Expérience du Matériel Automobile (CEMA) at Vincennes; it was a machine gun-armed tankette without turret. It was tested until 4 March 1935, when it was replaced by the second identical prototype to be tested until May 6th. Both had to be rejected because new specifications had been made on June 21st, 1934 that increased the desired armour thickness to 40 mm (1.6 in).

On August 19th, the third prototype was delivered, equipped with a cast APX turret and featuring a redesigned hull; it was tested until September 20th and accepted. On November 6th, 1935 a first order was made for 200 vehicles. Though it should have been completed between July 1936 and July 1937, the first production vehicle was in fact delivered on September 12th, 1936. A first additional orders had already been made of 92 on September 7th, 1936, to be completed in November 1937. A third one of 108 vehicles followed in January 1937, to be completed in September 1938. By January 1st, 1937 132 hulls had been produced. None of these had at that date yet been fitted with a turret. The first series vehicle was again extensively and intensively tested until 4 December 1936. The testing soon showed that its cross-country handling qualities were unacceptably poor. It was simply impossible to safely steer the vehicle on a somewhat bumpy surface, posing an extreme danger to nearby friendly infantry. The Infantry therefore initially rejected any further procurement. Eventually, in 1937, it decided to accept only the last hundred tanks to equip just two battalions with the type. For political reasons however, stopping production of the tank was unacceptable. As a result the first three hundred vehicles of the production run were offered to the Cavalry, which was forced to accept them because it would not have been granted a budget for other tanks anyway. The H 35 was, at 28 km/h (17 mph), also somewhat faster than the Renault R35, which was capable of 20 km/h (12 mph), although in practice its average speed was lower than that of the R 35 because of its inferior gear box.

The Hotchkiss H35 was a small vehicle, 4.22 m (13.8 ft) long, 1.95 m (6.4 ft) wide and 2.133 m (7.00 ft) tall and weighing 10.6–11.37 t (10.43–11.19 long tons). The hull consisted of six cast armour sections, bolted together: the engine deck, the fighting compartment, the front of the hull, the back of the hull and two longitudinal sections left and right forming the bottom. The hull was made water-tight by cementing these sections together with Aslic, a product based on tar mixed with lime. The casting allowed for sloped armour, avoiding shot traps, to optimise the chance of deflection but the protection levels did not satisfy the Infantry. Maximum armour thickness was not the specified 40 mm (1.6 in) but 34 mm (1.3 in). There were persistent quality problems, worsened by the fact that many subcontractors had to be used: at first the armour was made much too soft; when hardness was increased it became brittle and hence developed weak spots. There was a crew of two. The driver sat at the right front, behind a large cast double hatch and next to the combined gearbox and steering unit. Behind him was a round escape hatch in the bottom of the hull. Driving the vehicle was very hard work. The Hotchkiss lacked the Cleveland differential ("Cletrac") of its Renault competitor, and it responded unpredictably to changes of direction. The brakes could not sufficiently compensate for this, being too weak, especially when driving down-slope.

No less troublesome was the gearbox: it was difficult to engage the highest fifth gear and so the theoretical top speed of 27.8 km/h (17.3 mph) was rarely reached. There was one reverse gear. The inevitable rough handling of the tank by the driver resulted in much wear and tear. Mechanical reliability was poor. The suspension consisted of three bogies per side—each formed of two bell cranks arranged as "scissors" with springs at the top. Each bogie carried two rubber-rimmed wheels. The bogies superficially resembled the R35 type, but used horizontal helical springs instead of rubber cylinders. The sprocket was at the front, the idler which itself was sprung to automatically control tension at the rear. There were two top rollers. The tank was powered by a 78 hp six-cylinder 86 x 100 3485 cc engine which was on the left of the engine compartment. A 160-litre fuel tank on the right, combined with a twenty litres reserve reservoir, gave a range of 129 km (80 mi) or eight hours on a varied terrain. Also a cooling fan drew air through the radiator and was also expected to cool the fuel tank. The trench-crossing capacity was 1.8 m (5.9 ft), the wading capacity 85 cm (33 in). The APX-R turret was the same standard type as used on the R35 and R40 tanks, made of 40 mm (1.6 in) cast steel and armed with the short 37 mm SA 18 gun, which had a maximum armour penetration of only 23 mm (0.91 in). Traverse of the turret was with a handwheel. The commander sat in a saddle suspended from the turret. The tank carried about 100 rounds for the gun, and 2,400 rounds for the coaxial 7.5 mm Reibel machine gun – the 37 mm ammunition racked on the left hand side of the hull, the 7.5 mm ammunition on the right side in fifteen circular magazines with 150 rounds each; a final magazine was to be at the ready on the machine-gun itself.

For access there was a hatch at the back of the turret. When opened, the commander could sit on it for better observation, but this left him very vulnerable and slow to reach the gun. The alternative was to fight closed-up, observing through the vertical slits or the visor of the hatchless cupola. The Cavalry liked neither this arrangement nor the weak gun. The latter problem was lessened somewhat by enlarging the breech so that special rounds with a larger charge could be used. This increased muzzle velocity to about 600 m/s (2,000 ft/s) and maximum penetration to about 30 mm (1.2 in). In the Spring of 1940 the original diascopes of the Chrétien type were gradually replaced with episcopes, offering more protection.

In the Cavalry arm, the main user at first, the Hotchkiss tanks replaced as main combat tanks the light AMR 33 and AMR 35 vehicles, that for want of a better type had been used to form the bulk of the first two Cavalry armoured divisions. As the new medium SOMUA S35 was initially produced in very limited numbers, until early 1939 the Hotchkiss equipped three of the four divisional tank regiments. In April 1940 the 342e CACC (Compagnie Autonome de Chars de Combat or "Independent Tank Company") was sent to Norway after Operation Weserübung, the German invasion of that country, having first been intended to form part of an expeditionary force to assist Finland in the Winter War. This autonomous company, equipped with fifteen Char léger modèle 1935 H modifié 39, all with short guns, fought in the later phase of the Battles of Narvik, after having landed on May 7th. According to the official army acceptance lists, at the start of World War II 640 Hotchkiss tanks had been delivered. The inventories deviate slightly: of the 300 H35s allocated to the Cavalry, 232 were fielded by ten cavalry squadrons, 44 were in depot, eight in factory overhaul and sixteen in North Africa. Of the H39s, sixteen were used by the Cavalry in North Africa and six in depot; 180 were fielded by four Infantry tank battalions and fourteen were in the Infantry matériel reserve. It was decided to concentrate most Allied production capacity for light tanks into the manufacture of a single type, and the Hotchkiss tank was chosen as it had the necessary mobility to be of use in the many armoured divisions the Entente planned to raise for the expected decisive summer offensive of 1941. To this end British and Portuguese heavy industry had to assist in producing the cast armour sections. It was hoped to increase production to 300 a month in October 1940, and even 500 a month from March 1941, the sections of 75 of which to be provided by Britain in exchange for a monthly delivery of nine Char B1s.

These plans were disrupted by the Battle of France. In May 1940 the type equipped in the Cavalry units two tank regiments (of 47) in each of the three Mechanised Light Divisions and served as AMR in the 9th and 25th Mechanised Infantry Division. Furthermore, sixteen vehicles were part of the 1er RCA in Morocco. In the Infantry it equipped the two autonomous battalions mentioned above and two battalions of 45 in each of the three Divisions Cuirassées, the latter with the H39 variant. Most Hotchkiss tanks were thus concentrated in larger motorised units, in the armoured divisions supplementing the core of heavier tanks, though they were mismatched. Following the French defeat in the Battle of France about 550 Hotchkiss tanks were captured and used by the Germans as Panzerkampfwagen 35H 734(f) or Panzerkampfwagen 38H 735(f); most for occupation duty. Like the French, the Germans made no clear distinction between a H38 and a H39; and fitted many with a cupola with a hatch. Panzer-Abteilung 211 was deployed in Finland during Operation Barbarossa, equipped with Hotchkiss tanks. In 1944, three of its vehicles were converted to 7.5 cm self-propelled guns. German H35/39s also saw action in Yugoslavia with 7.SS-Freiwilligen-Gebirgs-Division "Prinz Eugen", 12. Panzer-Kompanie z.b.V. and I./Panzer-Regiment 202. In 1942 a project was launched to make use of French equipment as carrier platforms for heavier guns, directed by Major Alfred Becker, an artillery officer who was a mechanical engineer by trade. He had experience making similar conversions with captured Belgian and British vehicles. Some vehicles were modified into munition carriers or artillery tractors (Artillerieschlepper 38H(f)) or rocket-launchers (Panzerkampfwagen 35H(f) mit 28/32 cm Wurfrahmen). In June 1943, 361 Hotchkiss tanks were still listed in the German Army inventories as 37 mm gun tanks; this number had decreased to sixty in December 1944.

Three Hotchkiss tanks of the "H39" version had been exported by France to Poland in July 1939 for testing by the Polish Bureau of Technical Studies of Armoured Weapons, with a view to a larger purchase. During the German invasion of Poland in 1939 the Hotchkiss tanks, together with three Renault R 35 tanks, were organised into an ad hoc "half company" unit under lieutenant J. Jakubowicz, formed on September 14th, 1939 in Kiwerce, Poland. The unit joined the "Dubno" task force and lost all of its tanks during the marches and fighting against German and Soviet armies, due to fuel shortages. In North Africa, 27 vehicles (thirteen H35 and fourteen H39) were officially serving in the 1e Régiment de Chasseurs d'Afrique and were allowed to remain there by the armistice conditions; another five were hidden in Morocco. They fought the Allies during the opening stages of Operation Torch, the Allied invasion of French North Africa, near Casablanca in November 1942, destroying four M3 Stuart light tanks. The regiment then joined the allied cause and was re-equipped with M4 Sherman medium tanks in the summer of 1943. After the war, some Hotchkiss tanks were used by French security forces in the colonies, such as French Indochina, and occupation forces in Germany. Ten H39s were clandestinely sold to Israel, they were shipped from Marseilles to Haifa in 1948.

One Hotchkiss H35 and nine Hotchkiss H35s modifié 39 have survived to this present day, all of the modifié 39 were further modified by the Germans during World War II.

[snicketstrange]

The contents of the sugar bowl were radioactive

This is a new hypothesis about the SB. I believe that I finally found something that closes all the gaps. The hypothesis is that within the SB that belonged to Esme you will find radioactive stones (or powder from radioactive stones). Let's just use as an example something that exists in our universe: Uranium. Now let's look at the reasons. The deadly fungus MM can be used as a weapon of mass destruction. But not any kind of weapon of mass destruction. It is a biological weapon. Kit hinted that if Olaf got his hands on SB, we would be in a scenario almost as bad as if Olaf got his hands on SB. So, I deduce that just something that can be used as a weapon of mass destruction could be almost as bad as MM. (Note .: Like MM, uranium can also be used for good, to produce electricity.) Kit said: "The sugar bowl is on its way to the hotel even as we speak, and I'd hate to think what would happen if our enemies got ahold of it. I can't imagine anything worse, except perhaps if our enemies somehow got ahold of the Medusoid Mycelium. " (TPP chapter 2) Radioactive stones like uranium can be used both to produce atomic bombs and to produce dirty bombs, that is, use the power of radiation to cause death. In addition, Esmé stated that the content of the SB was found on a kind of mission, where many volunteers died. Notice what she said: "Then you know all about the sugar bowl," Esmé said, "and what's inside. You know how important that thing was, and how many lives were lost in the quest to find it. You know how difficult it was to find a container that could hold it safely, securely, and attractively. You know what it means to the Baudelaires and what it means to the Snickets. " (TPP chapter 9) Uranium is a radioactive element, so it makes sense that volunteers have died from not using adequate protection. (note: Some believe that the volunteers died in the search for the container set with the contents. But if you read this section carefully you will clearly see that the deaths happened when a team was looking for "that thing", and "that thing" is the that we had inside the SB. We know that this is because shortly afterwards Esmé said it was difficult to find a container that could contain that. The container found was the sugar bowl itself.) In addition, speaking of electrical energy, it is possible that uranium was used to create the nuclear reactor that served as propulsion for submarine Q. And so it was Kit who built the submarine. After all, according to Esmé, the Snickets had a special relationship with the content of the SB. Submarine Q is different from submarine C in a fundamental and very prominent issue: there are only two crew members and a captain. On the other hand, submarine C needs human propulsion, and so it needed slaves to be captured in order for the submarine to work. Captain W seems to know a lot about the SB's content, which may indicate that his submarine's propulsion was related to the SB's content. In addition, when refined using lime, uranium is white and could easily be mistaken for sugar. Esmé stated that it was necessary to find a beautiful and safe container for the contents of the SB. Why "safe"? Because it would be necessary to contain radiation. That's why SB ended up in GG. Dewey and Kit threw objects from the headquarters window so that those objects would land in a safe place in the ocean. But SB ended up in a very different and unknown (and not at all safe) place. This probably happened because SB was made of lead, a material that has a very high specific gravity. (Lead is capable of containing radiation.) Thus, the SB behaved differently from all other objects thrown out the window, because it was made of lead. And the SB was made of lead to contain the uranium radiation inside it. There is one more interesting detail. Uranium generates energy through nuclear fission. What is Nuclear fission if not a small schism with the power to wreak havoc? The Schism that happens inside the nucleus represents very well the VFD Schism that ended up generating great Unfortunate Events. Daniel Handler probably came up with this idea when looking up synonyms for the word "schism" in a dictionary. But the evidence doesn't stop there. During the VFD construction committee meeting, Olaf removed an item from a box, and everyone was alarmed about it. At first I thought that item could be MM, but it doesn't make sense for MM to be kept in a box. It makes more sense that a radioactive stone research had been stored inside a lead box. So soon someone asked Olaf to put the stone back in the box, to avoid the effects of radiation. At that time, Esme had not yet found a beautiful container for uranium, but she soon resolved that. She used the SB itself, which was probably made of lead.

Note the excerpt: Chapter 3 of LSTUA: E: We're not going anywhere, you fools. O: Take a look at this! (gasps from quite a few people) L: Egad! M: Put that back in its box immediately! O: Not until I issue the following demands: Radiation is deadly, but it does not kill immediately, especially if it comes from stones found in nature. Olaf could hold such a stone for a few minutes, threatening everyone present, and yet health problems did not arise immediately. Still, M believes that in a box, that thing would not do any more damage. This fits perfectly with a radioactive stone, and when we associate this event with the fact that Esmé said it was difficult to find a beautiful and safe container to contain what was inside the SB, it all makes sense.

It is true that at the meeting someone mentions something about the secret of the SB, but this only indicates that many volunteers had a SB that served some other purpose. Esmé simply used the SB that belonged to her to store the stone that the team of volunteers had acquired on the mission where many of them died.

[annieboltonworld]

Juniper Publishers-Open Access Journal of Environmental Sciences & Natural Resources

Study of Heavy Metal Pollution in Arid and Semi-Arid Regions Due to Mining Activity: Sonora and Bacanuchi Rivers

Authored by GJ León-García

Abstract

A study of the Sonora and Bacanuchi rivers was conducted to assess the mobility and bioavailability of heavy metals. These rivers were affected by a spill caused by the mining activity of the region, which is considered the most important ecological disaster in the modern history of Mexico. BCR sequential extraction was performed to determine geochemical phases in which metals are found. The evaluation of heavy metal contamination was performed using Enrichment Factor (EF) and Geoaccumulation index (Igeo). Sediments showed high concentrations (mg/kg) of Cu (8-716), Cr (8-90), Fe (7,300-52,400), Mn (80-938), Ni (6-48), Pb (14-210) and Zn (41-470). Metal concentrations in geochemical phases exhibited the following order: residual>Fe/Mn oxides> exchangeable>organic matter. The order of mobility and/or bioavailability of metals was: Mn>Cu>Ni>Pb>Zn>Fe>Cr. EF showed an anthropogenic enrichment in both rivers for Cu, Cr, Mn, Ni, Pb and Zn, mainly derived from the mining activity. Values of Igeo were classified as non-contaminated to moderately contaminated. The Bacanuchi river showed moderate to strong contamination of Cu and Pb. The quality criteria comparisons (LEL and SEL) indicate both rivers are contaminated by metals and represent a danger to biota, due to the high metal mobility and bioavailability.

Keywords: Metals; Bioavailability; Sediments; Bacanuchi and Sonora rivers

Introduction

Sediments are the result of the deposition of particles that bring along material of rocks and minerals, heavy metals, organic matter, among others. Sediment deposition occurs by entrainment of both organic and inorganic particles [1]. Sediments play an important role in transportation of nutrients, metals and other pollutants through river systems to the oceans and seas of the world [2]. Contamination of sediments by heavy metals can occur naturally or anthropogenically [3]. The most important anthropogenic activities are the agricultural, industrial, manufacturing, and mining activities. Heavy metals are among the most common pollutants and their ecological impact is due to their toxicity, high persistence and non- degradability in the environment [4,5]. Sediments concentrate metals from aquatic systems and represent a suitable and strategic means for conducting pollution monitoring studies [6].

In sediment, metals can be found in different chemical species, and depending on the species in which it is found, bioavailability, mobility and its toxicity can be determined. The determination of the total metal content can be useful for sediment characterization; However, it does not provide enough information on the bioavailability or toxicity of metals [7,8].

Sequential extraction is a technique that is widely used for the determination of chemical speciation and possible associations between metals and sediment components [9]. The sequential extraction method proposed by the Community Bureu of Reference (BCR) classifies metals into three fractions: fraction I exchangeable and acid soluble fractions; fraction II reducible fraction or Fe and Mn oxide-associated fraction; fraction III oxidizable fraction or fraction bound to organic matter [10]. If the metal corresponds to the first geochemical fractions, it will be more bioavailable, that is, it will be more available to participate in metabolic reactions of living beings and, therefore, it will be potentially more toxic or bioaccumulable, depending on the type of metal and its concentration.

In order to estimate the there is an environmental impact due to metals and the level of contamination; there are parameters such as the enrichment factor (EF) and the Geoaccumulation index (Igeo) [5]. EF establishes whether the concentration of a metal comes from a natural or an anthropogenic source. Igeo determines the extent of metal pollution in sediments, considering the concentration of that metal in baseline samples [11]. In Mexico, the mining industry is a productive sector which contributes economically, historically and culturally, and it will continue to be one of the pillars in the development and growth of the country. However, there is a strong environmental impact attributed to the mining activity, especially when accidents occur, or when improper management of the process or damages occur in any stage of the mining cycle.

In Mexico, there are documented accidents, particularly in the Sonora region, where spills of acid solutions containing metals, have been dumped and have caused a negative impact to the environment [12-14]. In August 2014, a 40,000 m3 spill of acid waste, with high concentration of copper sulfate and low pH values, was reported from a mining dam located in the region of Cananea, Sonora affecting the Bacanuchi river stream, which is tributary of the Sonora river. The main metal contaminants contained in the spilled solution were: copper, aluminum, cadmium, chromium, iron, manganese and lead, which levels were above Mexican standards [15]. This spill is considered the most important ecological disaster in modern history of Mexico, and to our knowledge, there is no previously published information regarding the fate of such pollutants in the Sonora river system.

Based on the above, a study was carried out in the Bacanuchi and Sonora rivers, which objectives are: a) to estimate the origin and level of contamination by heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) in the sediments, based on EF and Igeo; b) to estimate the distribution of heavy metals in the different geochemical fractions of the sediments; c) to study the chemical behavior (re-mobilization) of the heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) in the geochemical fractions of sediments that may be available to biota and that may endanger human health, and c) to contribute to the study of aquatic ecosystems contaminated by mining activities in arid and semiarid regions in Mexico.

Methodology

Reagents and Apparatus

All reagents used in this research were analytical grade (Baker, Mexico). Deionized water (DI) was used in all the tests. All the glassware and equipment used to collect samples were prepared by soaking them in a 20 % (v/v) HNO3 solution for 3 days and then rinsed with DI water to reduce contamination risk by heavy metals. Hydrogen potential (pH) was determined using a portable pHmeter Thermo Scientific Orion 3-star benchtop. The measurement of heavy metal concentrations was determined using a Perkin Elmer atomic absorption Analyst 400 equipment. The wavelengths (nm) used for the analyses are: Cd 228.8, Cu 324.8, Cr 357.9, Fe 248.3, Mn 279.5, Ni 232.0, Pb 283.3 and Zn 213.9, respectively.

Study Area

The study area is located within the Cananea municipality, northeast of the state of Sonora, Mexico (Figure 1). In this area, one of the world's largest copper deposit is located, with an estimated production of 1.4x109 kg Cu, and smaller concentrations of Ag, Au, Pb, and Zn [16]. These mineral deposits can be found predominantly as pyrite, chalcopyrite, bornite, and, in a lesser extent, as galena. The total area of the mine is about 12 to 16 km2, and the waste dumps and heap leach pads occupy an area of 1,000 hectares, which have been originated throughout the life of the mine. Arroyo Las Tinajas has its origin near Represo Tinajas 1, located inside the mining facilities. The path of the Tinajas stream flows to the south where it joins the Bacanuchi river. Then, the Bacanuchi river joins the Sonora river near the town of Arizpe, Sonora. Subsequently, the Sonora river flows into Presa El Molinito, near the city of Hermosillo, Sonora.

The predominant climate in the region is tempered, semi-arid climate, with a maximum, minimum, and average annual temperature of 25, 10, and 18°C, respectively. Some researchers have reported environmental pollution associated with abnormal concentrations of metals in the Bacanuchi and Sonora rivers [17]. The rivers of Bacanuchi and Sonora are a vital source of water for most economical activities of the region, i.e., agricultural and livestock activities, besides being a water supply for nearby localities, such as Hermosillo, capital of the state of Sonora [13,17].

Sample Collection and Analysis

A field sampling campaign was conducted in October 2014, on the Bacanuchi and Sonora rivers. Sediment samples were collected from a total of 11 sampling stations (Figure 1). Samples were taken at three different points within the same sampling station, to make up a composite sample. One of the points was taken at the center of the river and the other two were taken at each riverside, at a depth of10 cm, using a polyethylene nucleator. Once collected, samples were put on ice and then transported to the laboratory for their further preparation and analysis. After collection, a reduction in volume was made using the cone and quartet method [18], then, they were grounded to a size smaller than 100 meshes (0.149|im) using a porcelain mortar. Hydrogen potential (pH) was determined using a Thermo Scientific Orion 3-star bench-top pH meter [18]. Sulfates were determined using the BaCl2 precipitation method according to Method 980.02 [19]. Sediment texture was also determined [20]. Sediment samples were divided into four fractions: clay (<0.004 mm), lime (0.063 0. 004 mm), sand (2-0.063 mm), and gravel (> 2 mm).

Analysis of Total Heavy Metals and Sequential Extraction

The sediments were totally digested with an acid mixture (HNO3-HF-HClO4) in a Teflon vessel. Residues were then dissolved with HNO3 and boric acid (2%) and diluted with deionized water to a volume of 100 mL. Total concentrations of Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn were analyzed by atomic absorption spectroscopy. A sequential extraction procedure was performed following recommendations of the Community Bureu of Reference (BCR) [10]. Heavy metals were divided into three fractions according to the sequential extraction method: Fraction I (exchangeable and acid soluble fraction): sediment samples were extracted with acetic acid 0.11 mol L-1 for 16 h. Fraction II (Fe/Mn oxides): The residue from the previous extraction is then extracted by hydroxylamine hydrochloride 0.5 mol L-1 for 16 h. Fraction III (oxidable fraction or bound to organic matter): The residue is then oxidized with H2O2 8.8 mol L-1 and then, it is extracted with ammonium acetate 1.0 mol L-1. Residual fraction. The residual metal concentrations were determined by digestion with aqua regia. After each extraction, samples were centrifuged at 3,000 g during 20 min, at room temperature. Each extract was separated and retained in a stoppered polyethylene container for analysis. The determination of the metal concentrations was carried out using a Perkin Elmer atomic absorption equipment Analyst 400.

Quality Control

Sediment samples were analyzed by duplicate. Certified reference standard NIST 2702 (Inorganic Marine Sediment) were analyzed by triplicate and were treated similarly to sediment samples, to reduce matrix interferences and to validate accuracy and precision. Blanks were analyzed by triplicate. Five standards were used to get the calibration curve for each metal in the atomic absorption analyses, and high correlation coefficients (r > 0.9990) were obtained. Metal concentrations in the reference standard NIST were within 91-105% of the reference concentrations, which is acceptable.

Determination of Enrichment Factor and Geoacumulation Index

The enrichment factor (EF) is used to evaluate whether a sediment is enriched naturally or anthropogenically and, it has been commonly used to infer anthropogenic influences [6]. The EF method normalizes the concentrations of heavy metals with respect to a reference metal, the most common being Al and Fe [21]. Some authors propose that normalization with Fe is more adequate because of its relatively high natural concentration in the Earth's crust, since its distribution is not usually associated with the appearance of other metals [22,23]. For this reason, in the present study, Fe was used as a normalizing element. EF can be calculated using the following formula [5,24].

EF = (MxFeb)/(MbFex)

Where Mx and Fex are the concentrations of the metal and Fe in the sample; while Mb and Feb are the metal and Fe concentrations in a baseline sample. Igeo has been widely used to calculate levels of heavy metal contamination in sediments [25]. In the present study, the Igeo was calculated using the following equation [26].

Igeo = log2 [(Cn)/(1.5Bn]

Where Cn is the concentration of the element in the sample, and Bn is the concentration of the same element in a baseline sample. The geoaccumulation index comprises seven classes: Igeo ≤ 0 (class 0, uncontaminated); 0 27]. In the present study, baseline concentrations correspond to stream sediments located within the study area; however, they have not been polluted by the mining activity of the region [28]. On the other hand, a correlation analysis was performed to investigate the relationship between the studied heavy metals (Cd, Cu, Cr, Fe, Mn, Ni, Pb, Zn) and the physicochemical properties of the sediments.

Results and Discussion

Sediment Characterization

Sediments collected in the Bacanuchi river presented, mainly, a sandy texture (67 to 85 wt%), Represo Tinajas 1, presented a gravel-sandy texture (41 to 51wt%), meanwhile, the fine fractions (limes and clay) where present in a lesser extent. The previous fraction represented less than 5% of the total amount. In the Sonora river, sediments presented the following texture types: sand (34 to 77.5 wt%), gravel (7 to 50.6 wt%), silt and clay (<12%). The textural features in both rivers are similar (except the fine fraction). In both rivers the fractions of sands and gravel are much larger than the finer fractions in the sediments of both rivers. Studies have reported similar results [16]. Previous studies report that variations in the particle size of the sediments are related to the patterns of water flow [29]. The textural analysis shows texture is strongly dependent on the water flow processes affecting the area.

Regarding the distribution of metals in the different granulometric fractions of the sediments, the results indicate that the sand fraction plays a primordial role in the storage of metals. In this fraction, the metal levels fluctuated in the following percentages: Cu (54 - 89 %), Cr (52 - 89 %), Fe (51 - 89 %), Mn (53 - 88 %), Ni (48 - 88 %), Pb (46 - 86 %) and Zn (51 - 84 %). In the gravel fraction, significant amounts of metals were also observed: Cu (7 - 37%), Cr (6 - 39%), Fe (7 - 41%), Mn (10- 40%), Ni (8 - 43%), Pb (11 - 46%) and Zn (12 - 41%). Results indicate most of the metals were found in the coarse fractions (sands) and in the sand and gravel fractions for Represo Tinajas 1. Other studies have reported similar behaviors [16,30]. The results obtained in the Bacanuchi river sediments are different from those reported by other studies in the literature, which shows that the content of metals in sediments is mostly associated with particle size [29].

Physical and Chemical Characterization of Sediments

In Table 1, the results of the physicochemical analysis of sediments of the Sonora and Bacanuchi rivers are presented.Regarding to pH, the stations closer to the source of contamination (Represo Tinajas 1, pH 3.1), such as Arroyo Tinajas and Bordo de Contention were the ones with the lowest pH values (4.14 to 4.4), respectively. These sampling stations received the spill of Fe/Cu acid solutions from Represo Tinajas 1 in August 2014. The rest of the sampling stations showed a pH ranging from 7.46 to 8.56. The acidic conditions favor the mobilization of metals in sediments, increasing their solubility as the pH decreases [31]. An acidic pH value in a sediment may indicate that, under certain conditions, some metals found in the site may be dissolved when pluvial runoff occurs and thus be mobilized to other areas. On the other hand, the concentration of sulfates in both rivers fluctuated in the range of 0.02 to 1.7%. The highest concentration of sulfates occurred in Represo Tinajas 1 (1.7%), which is the source of contamination. The results of sulfates in sediments of the Bacanuchi and Sonora rivers (including Represo Tinajas 1) are low compared to other studies. Previous research report high concentrations of sulfates (4.51-5.63%) in sediments of the San Pedro river contaminated by the mining activity of the region [13].

* Source of contamination

BDL Below detection limit

Total Metal Determination in Sediment Samples

Total metals concentrations (mg/kg) in the Bacanuchi river fluctuated in the following ranges: Cd (Table 1). The Mn presented its maximum concentration (938 mg/kg) at Presa El Molinito (discharge), because it is located in a mineralized area. The mineralized areas (mineral deposits) influence the composition of aquatic systems, through the release of large amounts of metal ions [32]. Studies performed in the region where this reservoir is located have reported similar concentrations of Mn [33].

As for the behavior of the total metals concentration in the Bacanuchi river, the following order was observed: Fe>Cu>Mn>Zn>Pb>Cr>Ni. In the Sonora river, the order was as follows: Fe>Mn>Zn>Cu>Pb>Cr>Ni. Compared to other rivers in the world, total concentrations of Cu, Fe, Mn, Pb and Zn were much higher in the Bacanuchi river (except Paracatu river), while Cr and Ni were lower (Table 2). The Sonora river also had high concentrations of Cu, Mn, Pb and Zn with respect to sediments of the Tiaozi, Kuitum and Wei rivers, but lower than those reported in the Bacanuchi and Paracatu rivers (except Mn) [6,20,32,34].

Geochemical Distribution of Heavy Metals in Sediments

In Figure 2, the distribution of the metals in the different geochemical fractions of the sediment is presented.

Fraction I (Exchangeable and Acid Soluble Fraction): This fraction is generally considered as the bioavailable portion of metals and, if they are present at high enough concentrations, they may be toxic to aquatic organisms [35-37]. In the Bacanuchi river, the minimum and maximum concentrations (mg/kg) were Cu (7 - 149), Fe (27 - 141), Mn (11 - 201), Ni (1 - 2.70) and Zn (3 - 23). In the Sonora river, the concentrations were as follows: Cu (4,37].

Mobility and bioavailability in the Bacanuchi river were as follows: Mn>Cu>Fe>Zn>Ni; and in the Sonora river: Mn>Fe>Cu>Zn>Ni, therefore, metals accumulated in this fraction are more susceptible to be mobilized by changes in environmental conditions. Adsorption-desorption reactions, or a decrease in pH, change the ionic composition and could therefore remobilize metals in this fraction and turn them back to surface water where they may represent a potential hazard to the environment [37]. Cd, Cr and Pb presented values below the detection limit (

Fraction II. Fraction related to Fe/Mn oxides: In this fraction, metals are strongly bound to Fe/Mn oxides; however, they are thermodynamically unstable under anoxic conditions [38] and, therefore, they could be dissolved in the water column and thus mobilized [39]. The minimum and maximum concentrations (mg/kg) in the Bacanuchi river were: Cd and Cr (Figure 2). In the Sonora river had the following concentrations: Cu (1 - 12), Cr (

The highest concentrations of metals (Cu, Fe, Mn, Pb) were detected in the sediments of the Bacanuchi river, while in the Sonora river they were Cr, Ni and Zn. Mobility and bioavailability in the Bacanuchi river were as follows: Fe>Mn>Cu>Zn>Pb>Ni; and in the Sonora river: Fe>Mn>Pb>Zn>Cu>Ni. The fraction II presented the highest values with respect to the FI; it can be inferred that metals belonging to this fraction will have higher mobility and bioavailability than FI, and this will depend on changes in the pH and/or redox conditions of the sediment [24,38].

Fraction III. Fraction Associated with Organic Matter and Sulfides: The minimum and maximum concentrations (mg/ kg) of metals in the Bacanuchi river are Cu (3 - 104), Cr (Figure 2). In both rivers Cd and Pb were not detected (

Mobility and bioavailability in the Bacanuchi river were as follows: Fe>Cu>Mn>Zn>Ni>Cr; and in the Sonora river: Fe>Mn>Cu>Zn>Ni>Cr. It has been reported that the organic fraction (sulfides) is considered the most important component in the adsorption of metals in sediments. Some studies have reported high concentrations of metals associated with organic matter [2,38,40]. Some metals such as Cu can form complexes with organic matter, so that during their decomposition can cause their release into the environment.

Residual Fraction: Metals in this fraction are less harmful to the environment, because this fraction is chemically stable and biologically inactive [24]. Therefore, they are not likely to negatively impact surface water quality [2]. In the present study, the highest concentrations of most metals, in both rivers, were detected in this fraction. The Bacanuchi River presented the following percentages: Cu (35 - 51), Cr (98 - 100), Fe (84 - 93), Mn (29 - 77), Ni (71 - 95), Pb (83 - 91) and Zn (71 - 84). In the Sonora river, the percentages were Cu (16 - 75), Cr (79 - 99), Fe (90 - 95), Mn (10 - 60), Ni (Figure 2). Other studies have reported results similar to those obtained in the present research [8,13,16,41]. Metal concentrations in this fraction can be used as baseline data for the evaluation of the river system pollution. The stability of this fraction is controlled by the mineralogy and the extent of physicochemical weathering of the sediment [24].

Non-Residual Fraction: Metals in the non-residual fraction indicate the occurrence of anthropogenic contributions due to activities developed on areas nearby the river, such as mining and urban activities (untreated wastewater discharge). The non-residual metal fraction (FI+FII+FIII) was analyzed since this fraction is more bioavailable than the residual one. In the Bacanuchi river, the percentages of heavy metals in the nonresidual fraction fluctuated in the following ranges: Cu (48 - 65), Cr (4,42]. The possible metal mobility in the non-residual fraction, for the Bacanuchi and Sonora rivers, is as follows: Mn>Cu>Ni>Zn>Fe>Cr and Ni>Pb>Mn>Cu>Zn>Cr>Fe, respectively. For both rivers, high metal concentrations were observed in the non-residual fraction, hence, a high mobility and bioavailability are possible. Therefore, these metals may have an impact on water quality and a harmful effect on biota.

Enrichment Factor and Geoaccumulation Index

In the present study, the enrichment factor (EF) was calculated using sediment baseline samples that are not affected by the rivers under study or by anthropogenic activities [28]. The results of EF of each metal in both rivers fluctuated in the following ranges: Cu (0.7 - 8.9), Cr (0.4 - 3.8), Mn (0.4 - 3.6), Ni (0.7 - 5.5), Pb (0.4 - 8.9) and Zn (0.7 - 2.8) (Table 3). In most sampling stations, the EF value for Cu, Cr, Mn, Ni, Pb and Zn was above 1.0, indicating an enrichment that may be attributed to the mining activity of the region, specifically in the Bacanuchi river. Regarding Igeo, in the Bacanuchi river, the Bacanuchi station (before confluence) presented an Igeo of 2.1 for Cu indicating a moderate and strong contamination; the Poblado Bacanuchi and the Bacanuchi (before confluence) stations had Igeo values of 1.4 and 2.1 for Pb, presenting moderate and strong contamination. In the Sonora river, the Sinoquipe station presented a value of 1.0 for Cr, indicating a null to moderate contamination (Table 3).

Spearman Correlation Analysis

To analyze the association between Physical parameters and total metal content, a Spearman correlation analysis was used, since most parameters do not have a normal distribution. Results indicate there was a positive correlation among metals such as Cu, Fe, Ni, Pb, Zn and the gravel fraction (r = 0.29 to 0.36); while sand fraction had negative correlations with Cu, Fe, Ni, Pb and Zn (r = -0.28 to -0.43) (Table 4). The fraction of silt had a positive correlation with Cu, Fe, Mn, Ni, Pb and Zn (r = 0.30 to 0.70), while the clay fraction was positively related to Fe, Mn and Zn (r = 0.51 to 0.64). Similarly, other studies report a strong correlation between heavy metals and particle size, being silt and clay the fractions most associated to metals due to their large specific surface area in which metals are adsorbed [43]. In general, most metals had a positive correlation between each other (r = 0.46 to 0.91), which may indicate a strong mineralogical association coming from the same origin, that is, the mining activity of the region. This agrees with data reported by other studies [43,44]. On the other hand, Cu, Fe, Mn, Pb and Zn showed a positive correlation with sulfates (r = 0.33 to 0.59), indicating that they may be associated as sulfates. Regarding pH, all metals (including sulfates) had negative correlations with pH values (r = -0.32 to -0.97). parameters, grain size and total metals of surface sediment.

*Significant at 0.05 level; "significant at 0.1 level

Sediment Quality Criteria

Total metal concentrations were compared to the Low Effect Level (LEL) and the Severe Effect Level (SEL) criteria, [45,46]. If metal concentration is higher than the LEL, that metal may moderately affect biota, and if the metal exceeds the SEL criterion, the metal may severely affect biota. Most of the sampling stations in both rivers exceeded the LEL quality criterion for Cr, Cu, Fe, Mn, Ni, Pb and Zn, thus a moderate effect on biota is possible (Table 5). The SEL criterion was only exceeded for Cu in the Bacanuchi river (Arroyo Tinajas, Bordo de Contention and Bacanuchi (before confluence)), and Fe in the Poblado Bacanuchi Station. This suggests that there could be a severe effect caused by Cu and Fe, to the biota. Previous research has reported similar results in San Pedro river sediments contaminated by mining activity in the state of Sonora, Mexico [16].

*Sampling stations that exceeded LEL and SEL levels.

Conclusion

A study was carried out to evaluate the mobility and bioavailability of heavy metals in sediments of the Sonora and Bacanuchi rivers, affected by the mining activity. The Bacanuchi river presented the highest levels of heavy metals, which concentrations had the following descending order: Fe>Cu>Mn>Zn>Pb>Cr>Ni>Cd. The Sonora river had the following order: Fe>Mn>Zn>Pb>Cu>Cr>Ni>Cd. Sediments in both rivers presented a sandy texture, with high concentrations of most of the analyzed metals. The sequential extraction study showed that the predominant order of metals was as follows: residual>Fe/Mn oxides>exchangeable>organic matter. However, a significant percentage of metals were associated with the nonresidual fraction, which represents anthropogenic contributions due to the region's mining activity. The potential mobility of metals in the non-residual fraction had the following order: Mn>Cu>Ni>Pb>Zn>Fe>Cr.

EF showed an enrichment of anthropogenic origin in both rivers for Cu, Cr, Mn, Ni, Pb and Zn, indicating an enrichment that may be derived from the mining activity of the region, specifically in the Bacanuchi river. Most Igeo values were within the classification of non-contaminated to moderately contaminated. Bacanuchi station (before confluence), showed moderate to strong contamination of Cu and Pb. In both rivers, the LEL criterion was exceeded for Cr, Cu, Fe, Mn, Ni, Pb and Zn, and therefore, a moderate effect on biota is expected. The SEL criterion was only exceeded for Cu and Fe in the Bacanuchi River. This may represent a danger to the biota of both rivers, due to their high mobility and bioavailability.

This study has generated important information on the concentration of metals, their mobility/bioavailability, and their possible effect on biota. However, future studies on water and sediment chemistry (including biota) are required to fully assess the Bacanuchi and Sonora rivers. These studies are particularly important due to the spill occurred in August 2014, in the Cananea region of Sonora, Mexico, which consequences have not yet been fully evaluated.

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Week 2 - Glass materials exploration research

Week 2

Develop materials exploration models to consider:

Glass:

Glass is basically made of these three raw materials: Soda, Lime, and Silica. The proportions of these materials can vary widely. Various types of glass can have other substances (especially metal oxides) or not have all three of these components. The molecules almost take on a random arrangement, which gives the material its transparency. This also explains the isometric quality of the glass.

Form:

Solid, transparent material, coloured non coloured through powdered/liquid dye. Made from natural and abundant raw materials (sand, soda ash and limestone) that are melted at very high temperature to form a new material. Normal float glass has a slightly greenish tint. This colouring can mainly be seen along the edge of the glass and is caused by the naturally existing ferric oxide in the raw materials. By selecting extremely ferric oxide-poor raw materials, or by undergoing a chemical bleaching process, the melt can be turned into an absolutely colour-neutral, extra white glass. Tinted glass can be produced using coloured mass. Chemical additives in the mixture allow green, grey, blue, reddish and bronze coloured glass to be produced during certain production floating line periods. Changing glass colour in the vat naturally means a considerable amount of work and increased cost due to scrap and loss in productivity. Thus, it is only produced for special campaigns. Most of today’s glass production is float glass, with thicknesses usually ranging from 2 – 25 mm and a standard size of 3.21 x 6 m that is used for further processing.

Textures:

Glass can be textured or untextured, depending on the method at which it was molded and made. It can be smooth or rough. The texture of the glass can be drastically changed if shattered or broken e.g can become sharp and unappealing.

Lighting Opportunities:

Lighting can be used in a range of ways with glass. Due to glass having a transparent from, light is able to fully shine through a sheet of glass. If glass has been fogged or textured light (natural or unnatural) is still able to fully reflect through that piece of glass. The only exception is when an added oxide or power is added to the glass which stops the transparency, therefore stopping the reflection of light.  Glass can also be mirrored where the light is able to be seen on one side not the other.

Structural Opportunities:

Glass can be thin and delicate or thick and robust. Through the design of the glass the more secure it becomes. E.g a curved vase is likely more durable than a sheet of glass. However Glazed areas have to be considered more as a part of the structure than as a barrier element, separating the comfortable inside space to the exterior environment. This structural glass is subjected to numerous loads, such as wind, snow, thermal stresses, people weight and impact. Glass has a different behaviour than other structural material, which needs to be understood to make an efficient use of glass in buildings. In effect, glass has very good mechanical properties (compressive strength...), but the main drawback is its brittleness. Unlike steel, glass cannot accommodate local high stresses. Instead, it cracks and, when the level of energy is so high that the cracks propagate on the glass' surfaces, it fractures. Glass can fracture without warning, and for this reason is under used in construction.

Joints and Connections:

Very smooth glass pieces can be joined by diffusion welding simply by heating the materials under pressure. The surfaces to be joined are pressed against each other at room temperature, which causes the surface layers up to a depth of some nanometre to break so that centres of physical contact form. Another form of creating connections is by using an adhesive. If glass is being joined onto a metal structure, the most common process is through Glass and metal can bond together by purely mechanical means, which usually gives weaker joints, or by chemical interaction, where the oxide layer on the metal surface forms a strong bond with the glass. The acid-base reactions are the main causes of interaction between glass-metal in the presence of metal oxides on the surface of metal. After complete dissolution of the surface oxides into the glass, further progress of interaction depends on the oxygen activity at the interface.

Expressing existing & new:

Today glass is often used in flat slab, sheet like structures which creates a modern and sleek look for new building designs. Looking back at how glass used to be structured and designed in spaces was often more playful and fun e.g Use of stain glass geometry and textured surfaces.

[siva3155]

300+ TOP HIGHWAY ENGINEERING Interview Questions and Answers

HIGHWAY ENGINEERING Interview Questions for freshers and experienced :-

road construction interview questions 1.What is Highway Engineering? Highway engineering is an engineering discipline branching from civil engineering that involves the planning, design, construction, operation, and maintenance of roads, bridges, and tunnels to ensure safe and effective transportation of people and goods. 2. What Is The History Of Highway Engineering? History of highway engineering : The history of highway engineering gives us an idea about the roads of ancient times. Roads in Rome were constructed in a large scale and it radiated in many directions helping them in military operations. Thus they are considered to be pioneers in road construction. In this section we will see in detail about Ancient roads, Roman roads, British roads, French roads etc. 3. Explain About Ancient Roads? Ancient Roads : The first mode of transport was by foot. These human pathways would have been developed for specific purposes leading to camp sites, food, streams for drinking water etc. The next major mode of transport was the use of animals for transporting both men and materials. Since these loaded animals required more horizontal and vertical clearances than the walking man, track ways emerged. The invention of wheel in Mesopotamian civilization led to the development of animal drawn vehicles. Then it became necessary that the road surface should be capable of carrying greater loads. Thus roads with harder surfaces emerged. To provide adequate strength to carry the wheels, the new ways tended to follow the sunny drier side of a path. These have led to the development of foot-paths. After the invention of wheel, animal drawn vehicles were developed and the need for hard surface road emerged. Traces of such hard roads were obtained from various ancient civilization dated as old as 3500 BC. The earliest authentic record of road was found from Assyrian empire constructed about 1900 BC. 4. Explain Roman Roads? The earliest large scale road construction is attributed to Romans who constructed an extensive system of roads radiating in many directions from Rome. They were a remarkable achievement and provided travel times across Europe, Asia minor, and north Africa. Romans recognized that the fundamentals of good road construction were to provide good drainage, good material and good workmanship. Their roads were very durable, and some are still existing. Roman roads were always constructed on a firm - formed sub grade strengthened where necessary with wooden piles. The roads were bordered on both sides by longitudinal drains. The next step was the construction of the agger. This was a raised formation up to a 1 meter high and 15 m wide and was constructed with materials excavated during the side drain construction. This was then topped with a sand leveling course. The agger contributed greatly to moisture control in the pavement. The pavement structure on the top of the agger varied greatly. In the case of heavy traffic, a surface course of large 250 mm thick hexagonal flag stones were provided. A typical cross section of roman road is given in Figure 1 The main features of the Roman roads are that they were built straight regardless of gradient and used heavy foundation stones at the bottom. They mixed lime and volcanic puzzolana to make mortar and they added gravel to this mortar to make concrete. Thus concrete was a major Roman road making innovation. 5. Explain French Roads? The next major development in the road construction occurred during the regime of Napoleon. The significant contributions were given by Tresaguet in 1764 and a typical cross section of this road is given in Figure 1. He developed a cheaper method of construction than the lavish and locally unsuccessful revival of Roman practice. The pavement used 200 mm pieces of quarried stone of a more compact form and shaped such that they had at least one flat side which was placed on a compact formation. Smaller pieces of broken stones were then compacted into the spaces between larger stones to provide a level surface. Finally the running layer was made with a layer of 25 mm sized broken stone. All this structure was placed in a trench in order to keep the running surface level with the surrounding country side. This created major drainage problems which were counteracted by making the surface as impervious as possible, cambering the surface and providing deep side ditches. He gave much importance for drainage. He also enunciated the necessity for continuous organized maintenance, instead of intermittent repairs if the roads were to be kept usable all times. For this he divided the roads between villages into sections of such length that an entire road could be covered by maintenance men living nearby. 6. Explain British Roads? The British government also gave importance to road construction. The British engineer John Macadam introduced what can be considered as the first scientific road construction method. Stone size was an important element of Macadam recipe. By empirical observation of many roads,he came to realize that 250 mm layers of well compacted broken angular stone would provide the same strength and stiffness and a better running surface than an expensive pavement founded on large stone blocks. Thus he introduced an economical method of road construction. The mechanical interlock between the individual stone pieces provided strength and stiffness to the course. But the inter particle friction abraded the sharp interlocking faces and partly destroy the effectiveness of the course. This effect was overcome by introducing good quality interstitial finer material to produce a well-graded mix. Such mixes also proved less permeable and easier to compact. 7. Explain Modern Roads? The modern roads by and large follow Macadam's construction method. Use of bituminous concrete and cement concrete are the most important developments. Various advanced and cost-effective construction technologies are used. Development of new equipments help in the faster construction of roads. Many easily and locally available materials are tested in the laboratories and then implemented on roads for making economical and durable pavements. Scope of transportation system has developed very largely. Population of the country is increasing day by day. The life style of people began to change. The need for travel to various places at faster speeds also increased. This increasing demand led to the emergence of other modes of transportation like railways and travel by air. While the above development in public transport sector was taking place,the development in private transport was at a much faster rate mainly because of its advantages like accessibility, privacy, flexibility, convenience and comfort. This led to the increase in vehicular traffic especially in private transport network. Thus road space available was becoming insufficient to meet the growing demand of traffic and congestion started. In addition, chances for accidents also increased. This has led to the increased attention towards control of vehicles so that the transport infrastructure was optimally used. Various control measures like traffic signals, providing roundabouts and medians, limiting the speed of vehicle at specific zones etc. were implemented. With the advancement of better roads and efficient control, more and more investments were made in the road sector especially after the World wars. These were large projects requiring large investment. For optimal utilization of funds, one should know the travel pattern and travel behavior. This has led to the emergence of transportation planning and demand management. 8. What is the Highway Planning In India? Highway planning in India : Excavations in the sites of Indus valley, Mohenjo-dero and Harappan civilizations revealed the existence of planned roads in India as old as 2500-3500 BC. The Mauryan kings also built very good roads. Ancient books like Arthashastra written by Kautilya, a great administrator of the Mauryan times, contained rules for regulating traffic, depths of roads for various purposes, and punishments for obstructing traffic. During the time of Mughal period, roads in India were greatly improved. Roads linking North-West and the Eastern areas through gangetic plains were built during this time. After the fall of the Mughals and at the beginning of British rule, many existing roads were improved. The construction of Grand-Trunk road connecting North and South is a major contribution of the British. However, the focus was later shifted to railways, except for feeder roads to important stations. 9. Explain Jayakar Committee? The first World war period and that immediately following it found a rapid growth in motor transport. So need for better roads became a necessity. For that, the Government of India appointed a committee called Road development Committee with Mr.M.R. Jayakar as the chairman. This committee came to be known as Jayakar committee. Jayakar Committee : In 1927 Jayakar committee for Indian road development was appointed. The major recommendations and the resulting implementations were: Committee found that the road development of the country has become beyond the capacity of local governments and suggested that Central government should take the proper charge considering it as a matter of national interest. They gave more stress on long term planning programme, for a period of 20 years (hence called twenty year plan) that is to formulate plans and implement those plans with in the next 20 years. One of the recommendations was the holding of periodic road conferences to discuss about road construction and development. This paved the way for the establishment of a semi-official technical body called Indian Road Congress (IRC) in 1934 The committee suggested imposition of additional taxation on motor transport which includes duty on motor spirit, vehicle taxation, license fees for vehicles plying for hire. This led to the introduction of a development fund called Central road fund in 1929. This fund was intended for road development. A dedicated research organization should be constituted to carry out research and development work. This resulted in the formation of Central Road Research Institute (CRRI) in 1950. 10. What About Nagpur Road Congress? Nagpur road congress 1943 : The second World War saw a rapid growth in road traffic and this led to the deterioration in the condition of roads. To discuss about improving the condition of roads, the government convened a conference of chief engineers of provinces at Nagpur in 1943. The result of the conference is famous as the Nagpur plan. A twenty year development programme for the period (1943-1963) was finalized. It was the first attempt to prepare a co-ordinated road development programme in a planned manner. The roads were divided into four classes: National highways which would pass through states, and places having national importance for strategic, administrative and other purposes. State highways which would be the other main roads of a state. District roads which would take traffic from the main roads to the interior of the district . According to the importance, some are considered as major district roads and the remaining as other district roads. Village roads which would link the villages to the road system. The committee planned to construct 2 lakh kms of road across the country within 20 years. They recommended the construction of star and grid pattern of roads throughout the country. One of the objective was that the road length should be increased so as to give a road density of 16kms per 100 sq.km.

HIGHWAY ENGINEERING Interview Questions 11. What is Bombay Road Congress? The length of roads envisaged under the Nagpur plan was achieved by the end of it, but the road system was deficient in many respects. The changed economic, industrial and agricultural conditions in the country warranted a review of the Nagpur plan. Accordingly a 20-year plan was drafted by the Roads wing of Government of India, which is popularly known as the Bombay plan. The highlights of the plan were: It was the second 20 year road plan (1961-1981) The total road length targeted to construct was about 10 lakhs. Rural roads were given specific attention. Scientific methods of construction was proposed for the rural roads. The necessary technical advice to the Panchayaths should be given by State PWD's. They suggested that the length of the road should be increased so as to give a road density of 32kms/100 sq.km The construction of 1600 km of expressways was also then included in the plan. 12. Define Lucknow Road Congress ? Lucknow road congress 1984 : This plan has been prepared keeping in view the growth pattern envisaged in various fields by the turn of the century. Some of the salient features of this plan are as given below: This was the third 20 year road plan (1981-2001). It is also called Lucknow road plan. It aimed at constructing a road length of 12 lakh kilometres by the year 1981 resulting in a road density of 82kms/100 sq.km The plan has set the target length of NH to be completed by the end of seventh, eighth and ninth five year plan periods. It aims at improving the transportation facilities in villages, towns etc. such that no part of country is farther than 50 km from NH. One of the goals contained in the plan was that expressways should be constructed on major traffic corridors to provide speedy travel. Energy conservation, environmental quality of roads and road safety measures were also given due importance in this plan. 13. What Is The Sequence Of Four Stages Of Survey In A Highway Alignment? map study reconnaissance prelimi­nary survey detailed survey 14. What Is The Effect Of Grade On Safe Overtaking Sight Distance? To increase it on both descending and ascending grades. HIGHWAY ENGINEERING Questions and Answers Pdf Download Read the full article

[cement-epc-blog]

Wear - resistant treatment of lime production bin in cement factory

Product introduction:https://www.cementepc.net/epc/

Limestone silo of raw material batching station is composed of main silo and buffer silo, all made of steel plate.Upper main warehouse for Φ 8 m straight cylinder, the lower as the cone, the thickness of the steel plate to 8 mm;Buffer warehouse upper cone, the lower part for the irregular polyhedron, the main buffer material, easy to clear the role of blocking.Because of its small area, short production cycle and convenient installation, the steel limestone warehouse is adopted by most cement factories. However, in production, there is a big problem of inner wall wear. We have improved it.

1. Questions and analysis

(1) due to the large size of limestone, sometimes more than 120mm, plus the large drop of limestone into the bin, and the central cutting, will form a cone heap in the middle of the bin, and then roll around, hitting the inner wall of the steel bin, causing damage to the bin.Especially in the case of raw material storage in advance, the limestone impact force is greater, especially for the cone buffer bin greater harm.

2) in the production, limestone is used the most in the raw material ratio. For the 6000t/d production line, the amount used per hour is about 360t.Due to the impact of limestone for a long time, coupled with the friction of materials on the wall in the process of falling, the steel plate will become thinner and thinner, and eventually will be worn through leading to leakage, which not only pollutes the environment, but also increases the labor intensity of workers. If not handled in a timely manner, there are certain safety risks.

2 solutions

In order to avoid the above situation, it is necessary to do wear-resisting, impact resistant treatment to the inner wall of limestone bin.At the beginning, we laid polymer polyethylene wear-resistant board on the inner wall of the warehouse.This kind of plank has certain wear resistance, but impact resistance is bad, polyethylene board fell off phenomenon appeared after using a few months, service life is shorter, wasted financial capacity not only, also caused certain harm to warehouse.What's more, if the polyethylene plate that falls off is large and not found in time, it will affect the normal operation of the grinding belt and the vertical grinding, and even cause shutdown.

After several attempts, the following methods were finally adopted:

(1) on the straight part of the warehouse, the warehouse wall, the material can contact area of pavement to replace the old steel wire adhesive tape, and then fixed with heavy head bolt through tape in the warehouse wall, and near the tape along the perpendicular to the warehouse wall welding keep-off plate 100 mm wide, prevent material impact tape edge, so to protect the adhesive tape and prolonging its service life.

It should be noted that when drilling the rubber belt, the diameter of the drill bit should be close to the distance between the two adjacent strands of steel wire, and the force should be appropriate, not too large, not too small, and often water the drill bit to cool, to prevent the drill bit from breaking.As the steel tape is heavy, it should be divided into small pieces about 1m long by cutting machine before installation, which is convenient for installation.In addition, after the bolts are tightened, weld the nut and screw together to prevent the bolts from loosing and falling off.

(2) weld 100mm wide flat steel into a 400mm×400mm grid on the inner wall of the main bin cone, and the same 100mm wide flat steel into a 200mm×200mm grid on the inner wall of the buffer bin, and then install polyethylene wear-resistant board in the grid.During production, the material is stored on the grid, and the function of abrasive material is finally achieved, avoiding direct contact between the material and the inner wall of the steel bin.

3 the effect

After a period of production, we checked into the warehouse and found that the grid was basically filled with materials, including fine powder and block limestone. The effect was very ideal.Up to now, limestone bin has been used safely for more than a year, without any abnormal phenomenon, has a very good protective effect to steel bin, extended the service life of steel bin.

If you have any more questions about cement plants, please contact us. We will reply to you as soon as possible.

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[sickficprompts]

That Plague Fic I promised

So this is quite old now... Probably over a year old. It’s a Doctor Who fic based around the timebaby idea. There’s a whole backstory to the OCs here, but even posting this risks this blog getting found by someone who doesn’t know about it... so I’m not tagging it and you’re not getting other fics with these characters... I did want to show you the plague fic though. Enjoy! If you reblog, please don’t use Doctor Who tags and especially not River tags. Thanks!

NOTE: I believe there was going to be a chapter 3, but I actually don’t remember what was supposed to happen exactly. Just assume everyone lived, kay? :P 

Mothering:

She knew something was wrong before, but it became quite obvious when a head fell in her salad.

Renee jumped out of her chair, knocking it backwards, when the man across the thin table collapsed into her dish and his own. Everyone went silent. Even the sounds of metal against ceramic cut off.

Then there was chaos.

She hadn't know what was wrong exactly before. The residents of the palace she'd happened upon were uneasy, so she was a little unsure of accepting the dinner invitation presented to her by the child she'd found playing alone and needing someone to dress up.

Renee regretted taking the long gown when the chaos ensued; how was she to escape when she could barely walk without tripping?

In the throng, she heard shouts of the plague reaching them and the guard not being good enough. Someone screamed to save Astrea: the little girl Renee had played with earlier in the day.

For once, Renee didn't feel like the monsterous attendant in The Red Death. She was part of the crowd: scared and hoping to get out of this situation alive.

She pushed past the people, wondering how many may be unknowingly infected. Maybe she was unknowingly infected.

Renee had to get back to the little girl's room. She'd hidden the vortex manipulator there, deep in the wardrobe, to protect it when she wanted to make over Renee. If Astrea, only six and a half, had managed to use the device once, she wasn't sure if she could figure out how to get back.

A maid stopped her in a corridor by raising a clawed hand. Her face was not angry but curious. “Ma'am, who are you?”

“Hi,” she said, out of breath. “I'm Renee. I really have to get going.”

“Are you human?” She cocked her head to the side. Astrea really didn't look that different from a human child, aside from having owl ears and skin of a slightly more red tone. “Are you the human girl Astrea spoke of? She said she dressed you in her sister's clothes. Yes, those do appear to be Camilla's. Sad, that is.”

“I'm sorry?”

“Are you delirious? Have you the plague too? The elder princess!”

“What happened to her?” The woman stepped closer to Renee and tried to place her hand on the thirteen year old's face. She stepped back. “What are you doing?”

“You must be ill. Have you no brain?”

Renee glared at her.

“My apologies ma'am, but it is all that anyone will talk about. I'm not sure how you missed it. Camilla died of plague just before the Mrs decided to move the family here to the island. They all were tested first of course: no plague.”

“Someone brought it apparently,” Renee told her. “A man just passed out in his dinner.”

Her eyes widened in horror. “Girl, we must leave here quickly! I've noticed the early symptoms in others. I thought I was paranoid!”

Renee nodded. “I'm trying. That's why I've got to go.”

“Good luck to you.”

“Thanks.” Renee started walking again, and the maid hurried off.

She made it around the corner that lead to one last hallway before she froze.

One wall was lined with windows, and leaning against one was River Song. Her face was pale, nearly gray, and her eyes were downward cast. She didn't seem to notice Renee. All her focus was on her feet. On foot shakily slid forward. Her left shoulder was leaned against the window, and her right hand grasped at the frame with knuckles barely paler than the rest of her skin.

Renee couldn't move for a second.

Then River reached a long, red curtain, and hesitated. Slowly, she followed it up to the ceiling and back down to the floor, but when she stumbled and grabbed it for balance, it offered no support and the entire rod fell with her.

Renee rushed forward but not fast enough. River let out a simple, “Mmph!” of pain as she fell, the curtain pooled over her, and the rod hit her back in a single second.

“Mom?” Renee whispered. She pushed the rod and curtains off River and turned her over. She'd fainted. Her skin was burning hot and damp, almost sticky. “Oh god...”

What was she supposed to do now? She didn't even know what plague this was! She didn't have the history of the universe memorized... or the future. Which one was it?

River's eyes opened slightly, and Renee bent over her. She almost said 'Mom' again, but she realized River wouldn't know to answer to that and said, “River?”

She blinked.

“River?”

River groaned and averted her eyes. “M' fine...”

“River, you're not fine. You have the plague.”

She closed her eyes again. “Just dizzy...”

“I guess that's what Amy was talking about.” Renee remembered Amy's reaction to finding out Renee had gone a full week without telling her she'd fractured her ankle, and she hadn't been treated in that time at all. Rory was more upset, but Amy just sighed and said she really was River's daughter.

“What?” River opened her eyes slightly again. “Amy?”

Knowing perfectly well what she had meant, Renee said, “No. I'm Renee.”

“Renee?” River looked up at the window. “No.”

“I'm going to get something and be right back, okay? Then I'll help you.”

She shook her head, slowly. “No.”

“Why? What is it?”

“Contagious.”

Renee let herself sigh a laugh. “I've been here all day. I probably have it too.”

“Day... How'd you get here?”

Well, she was going to find out anyway when Renee came back with it. “A vortex manipulator.”

“Mm... Me too. Bad call.”

“I'd say so. I'll be right back.”

But she didn't want to leave River there. What would they do to her if they found her? If she remembered her Earth history correctly, at the very least, she'd likely be quarentined; maybe she'd be thrown outside or locked in a room. Either way, Renee wouldn't be able to get to her.

“If I help you, could you walk?”

River nodded, but Renee didn't believe her. After the ordeal with the curtains, she wondered if her mom would be able to make it to the end of the hallway, let alone to the other side of the palace.

“Okay. On the count of three?”

River nodded again.

“One.” Renee wrapped her arm around River's shoulders. “Two.” She hooked her forearms into River's underarms. “Three.” She pulled the older woman up and the two struggled to balance. Renee stumbled to her knees, bringing River with her, but managed to get back up. “You okay?”

There was no answer. She looked down at her mom, hunched over as much as she could be while still being supported. Her lips were pressed into a thin line.

“River?”

“Mm Hm...” She said without looking at her.

Still not convinced, Renee moved them slowly down the corridor. Her hearts were pounding. She was waiting for them to get caught, for them both to get in trouble.

It didn't happen. They got to Astrea's room without a hitch, and Renee helped River to sit on a fluffy couch before venturing into the wardrobe. At the very back, under a pair of lime green heels, she found the vortex manipulator.

“Who are you?” someone asked outside the door.

Renee froze.

“Ma'am, are you alright? What happened?” There was a shuffling noise, someone walking over the shag carpet, and then she heard them take a sharp breath. “Oh no!”

Renee knew she had to get River out of this, whatever it was, so she stumbled her way over the shoes and through the satin to get her.

Over the shoes and through the satin, to grandmother's house we go... her mind sang.

Another maid was standing by the door with her hand over her mouth, trying not to breath, and an older woman knelt in front of River, looking worried.

“Danya,” the maid said, sounding scared, “I must insist that you back away from her. She's infected.”

River had curled up on the couch and was nearly asleep. She murmered something that Renee doubted any of them understood and closed her eyes.

“I don't care,” Danya said. She pushed a curl behind River's ear. “It'll be all right my dear.”

“Danya,” the maid said, “Ma'am... I don't advise this.”

“Camilla's hair was similar. She looks like an older Camilla.” The woman was clearly sad, grieving, and Renee remembered the woman in the hallway saying that the Mrs had moved the family here after her eldest daughter had died. This must be the queen.

“Excuse me,” Renee said, hurrying forward. They couldn't mess up this time, whatever time this was. It affected a queen, a leader. They already may have messed up the family.

She looked up and threw her hands over her mouth. “Oh!”

The maid shook her head sadly. “No, ma'am.”

She stood and went to Renee so quickly, Renee didn't have time to move away. “Where did you get that dress? Are you the girl Astrea told me about? She was right. You look so much like Camilla.” She looked between River and Renee. “Do you have relation?”

Renee figured River was too out of it to process this. She nodded. “She's my mom.”

“Oh, sweetheart...” The woman's face fell.

“It's okay. I'm going to figure this out. If I can, I'll come back and help you all.” The promise was sort of true. She didn't know what she was going to do, but if she knew she could come back and fix this for them, she would.

“Where are you going? We're in quarentine.”

Renee raised her wrist. “This is a bit out of your time. Well, actually, it's a bit over your head. I'm sure there's at least a few agents floating around by now.”

She went to River and tried to rouse her. “River, can you hear me?”

“Girl,” the maid said, “Ma'am, why do you call her by name?”

Renee looked up a moment but quickly went back to gently shaking River's shoulder. “She doesn't know who she is to me. She can't. River? River, can you hear me?”

She moved a little, her breath changing the slightest bit. Renee nearly slumped into the seat beside her mother with relief.

“River, wake up.”

“Mmm?”

“We're going to go through the vortex now.”

She opened her eyes a little. They were unfocused but managed to amble their way around to each face and then to the vortex manipulator on Renee's wrist. Renee held it up to show her the coordinates. River murmured something uninteligable.

“We're going to Amy and Rory's,” Renee said, in case that had been what River had been trying to inquire about. She took River's hand with that which held her vortex manipulator and took one last look up at Astrea's mother. “Good luck.”

Then, Renee pressed the button, and they were in the vortex.

Chapter Two

Renee appeared in her room and River immediately fell with a gasp. Renee helped her onto the bed as she looked around, disoriented.

“This isn't my appartment,” she said, confused.

“I know. It's okay.”

“But where are we? What is all this?” She motioned around her widely as if to show Renee something that was surrounding them.

“Um, my room?”

“But...” She looked even more confused, and Renee realized this might be worse than she originally thought.

“Why don't you lay down, and I'll be right back.”

After a moment, River nodded, and Renee convinced her to lay back.

“Stay here,” she said, her tone firm.

River gave half a pout but nodded and went back to looking around the room. Before Renee had made it outside the door, she heard the sound of her mothers hand brushing against the wall and her weak voice. “It's like kittens... but scales.”

What did that even mean?

Renee headed downstairs. She didn't know what time it was, and she honestly didn't care. It was dark, so she went to Amy and Rory's room and flicked on the lights.

Amy sat up with a flourish, her eyes wide and rimmed with the purple of stress. “Renee?”

“I need Rory. Now.”

Without question, Amy turned and shook him. “Rory, wake up.”

“Mmph.”

Renee went over to help. “Rory, refusing to get up right now would likely be unintentionally what lead your daughter to and early and unwarrented death and therefor the nonexistance of your granddaughter, who I must remind you is me.”

He rolled over and looked at her. “One,” he mumbled, “Where do you read this stuff? Two, my daughter?”

Amy had focused intently on Renee's face. “Melody? She's here?”

Renee nodded. “Yeah, but-”

Amy was already out of bed and almost out of the room. Rory struggled into a sitting position.

“Amy!” Renee called after her. She was rushing up the stairs. “Amy, you-”

“Shush.”

She went straight into Renee's room. Renee was close enough by this point to hear the intake of breath. She pushed the door the rest of the way open as Amy was finally forming words. “Melody... What happened?”

Renee sighed. “I had a bit of a run in with a plague. We just happened to be in the wrong place at the wrong time at the same time.”

River was watching Amy intently, her look curious. “Mother? I can't see past all the- What is it again?” She looked to Renee for answers. Renee slumped against the door in defeat.

“It's the fever. That's what it is.”

“A fever? Whose fever? Is someone sick?”

Amy frowned and went to River more slowly now. “Sweetie, you're sick. Renee brought you home, so we can take care of you.”

“Um, yeah,” Renee said. Rory was coming up the stairs now. “I mostly came so Rory could help me.”

Amy looked a little disappointed, but she didn't argue.

Rory came in looking rustled and tired, but his face turned to shock upon seeing River in the bed. “You found her?”

“It's early River,” she warned. “We haven't met, but we sort of met up with a plague.”

“What sort of plague?” he asked, suspicious of their adventures by nature.

“The dead-princess and all-the-upper-class-is-quarentined sort of plague,” she admitted guiltily. “Which means we're going to have to sort of quarentine the house... Also, we have to find a cure.”

Rory looked tired. Amy looked ready to cry. River? She kept twirling Amy's hair in one hand and her own in the other, muttering something about how all blonde hair feels like cat fur, but all red hair feels like bunny fur, and The Doctor's hair feels like a dog's soft ear, and his hair would make a lovely blanket if that were possible without cutting it which she would never condone.

“Where were you?” Rory asked.

“The vortex manipulator has the coordinates. I don't really remember to be honest. I just kind of typed them in at random.”

“I thought we agreed you weren't going to do that anymore after your run in with Queen Victoria.”

Renee just shrugged.

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Fujifilm announces the launch of its all new iconic Instax mini 9

Fujifilm India Pvt Ltd., today, announced the launch of its new iconic instax mini 9 instant camera. Building on the worldwide success of instax mini 8, instax mini 9 will share the same iconic design and ease of use as its predecessor. It is priced at Rs 5,999.

In order to further wow its customer, the refreshed range sports versatile features by keeping in mind the latest trends. To meet especially the needs of the selfie lovers, the camera comes with a selfie mirror, close to the lens, to achieve the best angle. The new instax Mini 9 is also equipped with a close-up lens in addition to features such as automatic exposure measurement for aperture settings and high-key mode that enables users to take brighter photos – perfect for portraits.

This stylish, compact camera is the perfect tool for parties, festivals, events and days out, allowing users to capture more fun in retro prints with a simple point and shoot motion.  The instax mini 9 comes in five trendy new colors, “Flamingo Pink”, “Lime Green”, “Cobalt Blue”, “Smoky White” and “Ice Blue” designed to appeal to a broad range of consumers including the millennials, photo enthusiasts, young parent and almost anyone with an eye for design and creativity.

 Instant Photography has experienced much interest in recent years and instax has found favor amongst a broad range of customers including youth, female, school children and photo enthusiasts. One single physical print which captures a one-off moment has become more and more valuable amidst a modern avalanche of highly edited digital shots.

Commenting on the occasion, S.M.RAMPRASD, HOD- Image Capturing, Fujifilm India Pvt. Ltd. said, “Our Instax range is a unique product, the only one of its kind that enables users to create instant photos that can remain with them forever. Our Instax range of cameras has gained huge popularity over the years. The Sales Volume Trend for Instax has crossed 6.6 Million units globally in FY 2016 which clearly indicates its success worldwide. We are very excited to welcome our new iconic camera – the Instax mini 9 into the instax family equipped with upgraded technology and advanced features. The new product has been designed keeping in mind the ever changing preferences of the Indian youth, offering unique features to complement the needs of these young customers.” 

The Instax Mini 9 joins the instax family along with mini 25, mini 70, mini 90, Wide 300 and mini hello kitty.  

Main Features

1) Selfie mirror - Enjoy taking selfies!

You can check your framing with the mirror next to the lens.

  2) Close-up lens attachment

Close-up shooting up to 35cm away is possible

 3) Brightness adjustment

Specifications

 Product

instax mini 9

Film

FUJIFILM instax mini film

Picture Size

62 mm × 46 mm

Lens

2 components, 2 elements, f=60 mm, 1:12.7

Viewfinder

Real image finder 0.37× with target spot

Shooting range

0.6 m and beyond

Shutter Speed

1/60 sec.

Exposure Control

Manual switching system (LED indicator in exposure meter)

Film Feeding Out

Automatic

Film Developing Time

Approximately 90 seconds (Varies depending on the ambient temperature)

Flash

Constant firing flash (automatic light adjustment) Recycle time: 0.2 sec. to 6 sec. (when using new batteries)Effective flash range: 0.6 m – 2.7 m

Power Supply

Two AA-size 1.5V alkaline batteries Capacity: 100 shots (Approximately10 INSTAX mini 10-sheet film packs with new AA batteries)

Auto power off time.

5 min

Others

Exposure counter (number of unexposed films), film pack confirmation window

Dimensions

116 mm × 118.3 mm × 68.2 mm

Weight

307g (without batteries, strap and film pack)

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[siva3155]

300+ TOP HIGHWAY ENGINEERING Interview Questions and Answers

HIGHWAY ENGINEERING Interview Questions for freshers and experienced :-

road construction interview questions 1.What is Highway Engineering? Highway engineering is an engineering discipline branching from civil engineering that involves the planning, design, construction, operation, and maintenance of roads, bridges, and tunnels to ensure safe and effective transportation of people and goods. 2. What Is The History Of Highway Engineering? History of highway engineering : The history of highway engineering gives us an idea about the roads of ancient times. Roads in Rome were constructed in a large scale and it radiated in many directions helping them in military operations. Thus they are considered to be pioneers in road construction. In this section we will see in detail about Ancient roads, Roman roads, British roads, French roads etc. 3. Explain About Ancient Roads? Ancient Roads : The first mode of transport was by foot. These human pathways would have been developed for specific purposes leading to camp sites, food, streams for drinking water etc. The next major mode of transport was the use of animals for transporting both men and materials. Since these loaded animals required more horizontal and vertical clearances than the walking man, track ways emerged. The invention of wheel in Mesopotamian civilization led to the development of animal drawn vehicles. Then it became necessary that the road surface should be capable of carrying greater loads. Thus roads with harder surfaces emerged. To provide adequate strength to carry the wheels, the new ways tended to follow the sunny drier side of a path. These have led to the development of foot-paths. After the invention of wheel, animal drawn vehicles were developed and the need for hard surface road emerged. Traces of such hard roads were obtained from various ancient civilization dated as old as 3500 BC. The earliest authentic record of road was found from Assyrian empire constructed about 1900 BC. 4. Explain Roman Roads? The earliest large scale road construction is attributed to Romans who constructed an extensive system of roads radiating in many directions from Rome. They were a remarkable achievement and provided travel times across Europe, Asia minor, and north Africa. Romans recognized that the fundamentals of good road construction were to provide good drainage, good material and good workmanship. Their roads were very durable, and some are still existing. Roman roads were always constructed on a firm - formed sub grade strengthened where necessary with wooden piles. The roads were bordered on both sides by longitudinal drains. The next step was the construction of the agger. This was a raised formation up to a 1 meter high and 15 m wide and was constructed with materials excavated during the side drain construction. This was then topped with a sand leveling course. The agger contributed greatly to moisture control in the pavement. The pavement structure on the top of the agger varied greatly. In the case of heavy traffic, a surface course of large 250 mm thick hexagonal flag stones were provided. A typical cross section of roman road is given in Figure 1 The main features of the Roman roads are that they were built straight regardless of gradient and used heavy foundation stones at the bottom. They mixed lime and volcanic puzzolana to make mortar and they added gravel to this mortar to make concrete. Thus concrete was a major Roman road making innovation. 5. Explain French Roads? The next major development in the road construction occurred during the regime of Napoleon. The significant contributions were given by Tresaguet in 1764 and a typical cross section of this road is given in Figure 1. He developed a cheaper method of construction than the lavish and locally unsuccessful revival of Roman practice. The pavement used 200 mm pieces of quarried stone of a more compact form and shaped such that they had at least one flat side which was placed on a compact formation. Smaller pieces of broken stones were then compacted into the spaces between larger stones to provide a level surface. Finally the running layer was made with a layer of 25 mm sized broken stone. All this structure was placed in a trench in order to keep the running surface level with the surrounding country side. This created major drainage problems which were counteracted by making the surface as impervious as possible, cambering the surface and providing deep side ditches. He gave much importance for drainage. He also enunciated the necessity for continuous organized maintenance, instead of intermittent repairs if the roads were to be kept usable all times. For this he divided the roads between villages into sections of such length that an entire road could be covered by maintenance men living nearby. 6. Explain British Roads? The British government also gave importance to road construction. The British engineer John Macadam introduced what can be considered as the first scientific road construction method. Stone size was an important element of Macadam recipe. By empirical observation of many roads,he came to realize that 250 mm layers of well compacted broken angular stone would provide the same strength and stiffness and a better running surface than an expensive pavement founded on large stone blocks. Thus he introduced an economical method of road construction. The mechanical interlock between the individual stone pieces provided strength and stiffness to the course. But the inter particle friction abraded the sharp interlocking faces and partly destroy the effectiveness of the course. This effect was overcome by introducing good quality interstitial finer material to produce a well-graded mix. Such mixes also proved less permeable and easier to compact. 7. Explain Modern Roads? The modern roads by and large follow Macadam's construction method. Use of bituminous concrete and cement concrete are the most important developments. Various advanced and cost-effective construction technologies are used. Development of new equipments help in the faster construction of roads. Many easily and locally available materials are tested in the laboratories and then implemented on roads for making economical and durable pavements. Scope of transportation system has developed very largely. Population of the country is increasing day by day. The life style of people began to change. The need for travel to various places at faster speeds also increased. This increasing demand led to the emergence of other modes of transportation like railways and travel by air. While the above development in public transport sector was taking place,the development in private transport was at a much faster rate mainly because of its advantages like accessibility, privacy, flexibility, convenience and comfort. This led to the increase in vehicular traffic especially in private transport network. Thus road space available was becoming insufficient to meet the growing demand of traffic and congestion started. In addition, chances for accidents also increased. This has led to the increased attention towards control of vehicles so that the transport infrastructure was optimally used. Various control measures like traffic signals, providing roundabouts and medians, limiting the speed of vehicle at specific zones etc. were implemented. With the advancement of better roads and efficient control, more and more investments were made in the road sector especially after the World wars. These were large projects requiring large investment. For optimal utilization of funds, one should know the travel pattern and travel behavior. This has led to the emergence of transportation planning and demand management. 8. What is the Highway Planning In India? Highway planning in India : Excavations in the sites of Indus valley, Mohenjo-dero and Harappan civilizations revealed the existence of planned roads in India as old as 2500-3500 BC. The Mauryan kings also built very good roads. Ancient books like Arthashastra written by Kautilya, a great administrator of the Mauryan times, contained rules for regulating traffic, depths of roads for various purposes, and punishments for obstructing traffic. During the time of Mughal period, roads in India were greatly improved. Roads linking North-West and the Eastern areas through gangetic plains were built during this time. After the fall of the Mughals and at the beginning of British rule, many existing roads were improved. The construction of Grand-Trunk road connecting North and South is a major contribution of the British. However, the focus was later shifted to railways, except for feeder roads to important stations. 9. Explain Jayakar Committee? The first World war period and that immediately following it found a rapid growth in motor transport. So need for better roads became a necessity. For that, the Government of India appointed a committee called Road development Committee with Mr.M.R. Jayakar as the chairman. This committee came to be known as Jayakar committee. Jayakar Committee : In 1927 Jayakar committee for Indian road development was appointed. The major recommendations and the resulting implementations were: Committee found that the road development of the country has become beyond the capacity of local governments and suggested that Central government should take the proper charge considering it as a matter of national interest. They gave more stress on long term planning programme, for a period of 20 years (hence called twenty year plan) that is to formulate plans and implement those plans with in the next 20 years. One of the recommendations was the holding of periodic road conferences to discuss about road construction and development. This paved the way for the establishment of a semi-official technical body called Indian Road Congress (IRC) in 1934 The committee suggested imposition of additional taxation on motor transport which includes duty on motor spirit, vehicle taxation, license fees for vehicles plying for hire. This led to the introduction of a development fund called Central road fund in 1929. This fund was intended for road development. A dedicated research organization should be constituted to carry out research and development work. This resulted in the formation of Central Road Research Institute (CRRI) in 1950. 10. What About Nagpur Road Congress? Nagpur road congress 1943 : The second World War saw a rapid growth in road traffic and this led to the deterioration in the condition of roads. To discuss about improving the condition of roads, the government convened a conference of chief engineers of provinces at Nagpur in 1943. The result of the conference is famous as the Nagpur plan. A twenty year development programme for the period (1943-1963) was finalized. It was the first attempt to prepare a co-ordinated road development programme in a planned manner. The roads were divided into four classes: National highways which would pass through states, and places having national importance for strategic, administrative and other purposes. State highways which would be the other main roads of a state. District roads which would take traffic from the main roads to the interior of the district . According to the importance, some are considered as major district roads and the remaining as other district roads. Village roads which would link the villages to the road system. The committee planned to construct 2 lakh kms of road across the country within 20 years. They recommended the construction of star and grid pattern of roads throughout the country. One of the objective was that the road length should be increased so as to give a road density of 16kms per 100 sq.km.

HIGHWAY ENGINEERING Interview Questions 11. What is Bombay Road Congress? The length of roads envisaged under the Nagpur plan was achieved by the end of it, but the road system was deficient in many respects. The changed economic, industrial and agricultural conditions in the country warranted a review of the Nagpur plan. Accordingly a 20-year plan was drafted by the Roads wing of Government of India, which is popularly known as the Bombay plan. The highlights of the plan were: It was the second 20 year road plan (1961-1981) The total road length targeted to construct was about 10 lakhs. Rural roads were given specific attention. Scientific methods of construction was proposed for the rural roads. The necessary technical advice to the Panchayaths should be given by State PWD's. They suggested that the length of the road should be increased so as to give a road density of 32kms/100 sq.km The construction of 1600 km of expressways was also then included in the plan. 12. Define Lucknow Road Congress ? Lucknow road congress 1984 : This plan has been prepared keeping in view the growth pattern envisaged in various fields by the turn of the century. Some of the salient features of this plan are as given below: This was the third 20 year road plan (1981-2001). It is also called Lucknow road plan. It aimed at constructing a road length of 12 lakh kilometres by the year 1981 resulting in a road density of 82kms/100 sq.km The plan has set the target length of NH to be completed by the end of seventh, eighth and ninth five year plan periods. It aims at improving the transportation facilities in villages, towns etc. such that no part of country is farther than 50 km from NH. One of the goals contained in the plan was that expressways should be constructed on major traffic corridors to provide speedy travel. Energy conservation, environmental quality of roads and road safety measures were also given due importance in this plan. 13. What Is The Sequence Of Four Stages Of Survey In A Highway Alignment? map study reconnaissance prelimi­nary survey detailed survey 14. What Is The Effect Of Grade On Safe Overtaking Sight Distance? To increase it on both descending and ascending grades. HIGHWAY ENGINEERING Questions and Answers Pdf Download Read the full article