Coliform bacteria

Coliform bacteria are defined as Rod shaped Gram-negative non-spore forming and motile or non-motile bacteria which can ferment lactose with the production of acid and gas when incubated at 35–37°C. Due to the limited ability of certain coliform bacteria to ferment lactose, the definition has changed to bacteria containing the enzyme B-galactosidase, they are a used indicator of sanitary quality of foods and water. Coliforms can be found in soil and on vegetation. While coliforms themselves are not causes of serious illness, they are easy to culture, their presence is used to indicate that other pathogenic organisms of fecal origin may be present; such pathogens include disease-causing bacteria, viruses, or protozoa and many multicellular parasites. Coliform procedures are performed in anaerobic conditions. Typical genera include: Citrobacter Enterobacter Hafnia Klebsiella EscherichiaEscherichia coli can be distinguished from most other coliforms by its ability to ferment lactose at 44°C in the fecal coliform test, by its growth and color reaction on certain types of culture media.

When cultured on an eosin methylene blue plate, a positive result for E. coli is metallic green colonies on a dark purple media. Can be cultured on Tryptone Bile X-Glucuronide to appear as blue or green colonies after incubation period for 24 hours. Escherichia coli have an incubation period of 12–72 hours with the optimal growth temperature being 37°C. Unlike the general coliform group, E. coli are exclusively of fecal origin and their presence is thus an effective confirmation of fecal contamination. Most strains of E. coli are harmless. Infection symptoms and signs include bloody diarrhea, stomach cramps and fever; the bacteria can cause pneumonia, other respiratory illnesses and urinary tract infections. An easy way to differentiate between different types of coliform bacteria is by using an eosin methylene blue agar plate; this plate is inhibitory to Gram bacteria, will produce a color change in the Gram bacterial colonies based on lactose fermentation abilities. Strong lactose fermenters will appear as dark blue/purple/black, E.coli colonies will be dark colored, but will appear to have a metallic green sheen.

Other coliform bacteria will appear as thick, slimy colonies, with non-fermenters being colorless, weak fermenters being pink. Bacteriological water analysis Coliform index Fecal coliform Indicator bacteria Pathogenic Escherichia coli

Battle of Lauffeld

The Battle of Lauffeld known as Lafelt, Lawfeld, Maastricht or Val, took place on 2 July 1747, during the War of the Austrian Succession. A French army of 80,000 commanded by Marshal Saxe faced a combined British, Dutch and Austrian force of 60,000, led by the Duke of Cumberland. Under Saxe, arguably the most talented general of his generation, the French had conquered much of the Austrian Netherlands between 1744 to 1746. Cumberland intended to retake Antwerp in the spring of 1747 but failed to move enough. Saxe exploited a series of mistakes by Cumberland and only counterattacks by the Allied cavalry enabled the bulk of his army to withdraw in good order. Defeat ended Allied hopes of regaining lost ground and the French captured Bergen op Zoom in September Maastricht in May 1748. However, the cost of the war meant France's financial system was on the verge of collapse, while the British naval blockade caused severe food shortages, their position worsened in October 1747, when the British naval victory of Second Cape Finisterre left them unable to defend their merchant shipping or trade routes.

Both sides now wanted peace. When the War of the Austrian Succession began in 1740, Britain was focused on the 1739-1748 War of Jenkins' Ear with Spain, fought in the Caribbean. British and Dutch troops in Flanders did so as part of the army of Hanover. Supported by British financial subsidies, by the end of 1746 Austria had defeated Spanish efforts to regain possessions in Northern Italy lost in the 1713 Treaty of Utrecht. Austria acquired the Austrian Netherlands in 1713 only because neither the British or Dutch would allow the other to control it and retaining it was not a strategic priority. Maria Theresa now wanted peace. One reason France entered the war was to reduce the post-1713 expansion of British commercial strength, viewed as a threat to the European balance of power. By 1747, British trade had recovered from its post 1739 decline and was expanding once again, while the French economy was being strangled by their naval blockade. Victory at Rocoux in October 1746 confirmed French control of the Austrian Netherlands but failed to force Britain to end the war.

Declaring war on the Dutch made the immediate situation worse, since their previous neutrality meant they were the main carriers of French imports and exports. By 1747, the French financial system was on the verge of collapse, accompanied by severe food shortages. France began bilateral negotiations with Britain at Breda in August 1746 but these proceeded since the British envoy Lord Sandwich was under instructions to delay, hoping their position in Flanders would improve; the war continued. Although the British economy was impacted by the cost of the war, the government was far better equipped to finance it; the Duke of Newcastle wanted to continue the war and recover lost ground in the Austrian Netherlands. He hoped the death of Philip V in July 1746 provided an opportunity for Britain to entice Spain to end their long-standing alliance with France. By minimising French forces elsewhere, Saxe was able to assemble a field army of 120,000 men for the 1747 campaign; the defeat of the Jacobite Rising allowed Cumberland to transfer troops back to Flanders and prepare for an offensive.

The plan was to capture Antwerp in February but bad weather, lack of transport and war weariness meant the Allies were not ready to take the field until early May. Meanwhile, Saxe sent a detachment under Contades to take Fort Liefkenhock, north of Antwerp, while a second under Count Löwendahl seized Sas van Gent and Eekels in the Dutch province of Zeeland; the latter inspired an Orangist Coup in Zeeland, which led to William IV being appointed first hereditary Stadtholder of all seven Dutch provinces. This meant Antwerp was now too well-defended to attack, while the move into Zeeland threatened Cumberland's supply lines, forcing him to protect the key Dutch city of Maastricht. A detachment under von Daun was instructed to advance towards Tongeren, held by a force under Clermont-Tonnerre. Ligonier and the Allied cavalry were sent to occupy the Tongeren-Maastricht road, which ran along a ridge parallel to the River Meuse, but found the French in possession; the Allies halted and the infantry camped overnight in the villages of Vlytingen and Lauffeld.

As at Rocoux, the Austrians were on the right, holding the villages of Grote and Kleine Spouwen, now part of the Belgian town of Bilzen. A steep ravine in front protected them from a direct assault; the next day was overcast and it began raining making movement slow and difficult. An exchange of artillery fire began at 6:00 am, which continued until 8:30; the British and German infantry left the villages where they had spent the night, having first set them on fire to prevent their use by the French, formed up on open ground. Based on his experience at Fontenoy, Ligonier urged the villages be used as fortified positions. Saxe interpreted this confusion as Cumberland ordering a general retreat across the Meuse and around 10:30 sent troops into what he assumed were now empty villages. While true of

Benedict–Webb–Rubin equation

The Benedict–Webb–Rubin equation, named after Manson Benedict, G. B. Webb, L. C. Rubin, is an equation of state used in fluid dynamics. Working at the research laboratory of M. W. Kellogg Limited, the three researchers rearranged the Beattie–Bridgeman equation of state and increased the number of experimentally determined constants to eight. P = ρ R T + ρ. A modification of the Benedict–Webb–Rubin equation of state by Professor Kenneth E. Starling of the University of Oklahoma: P = ρ R T + ρ 2 + ρ 3 + α ρ 6 + c ρ 3 T 2 exp ⁡,where ρ is the molar density; the 11 mixture parameters are calculated using the following relations A 0 = ∑ i ∑ j x i x j A 0 i 1 / 2 A 0 j 1 / 2 B 0 = ∑ i x i B 0 i C 0 = ∑ i ∑ j x i x j C 0 i 1 / 2 C 0 j 1 / 2 3 D 0 = ∑ i ∑ j x i x j D 0 i 1 / 2 D 0 j 1 / 2 4 E 0 = ∑ i ∑ j x i x j E 0 i 1 / 2 E 0 j 1 / 2 ( 1 −