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The Marsh test is a highly sensitive method in the detection of arsenic, especially useful in the field of forensic toxicology when arsenic was used as a poison. It was developed by the chemist James Marsh and first published in 1836. [1] The method continued to be used, with improvements, in forensic toxicology until the 1970s. [2]
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- Apparatus Required
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Marsh cone test is a test carried out for discovering the optimum dosage of plasticizers and superplasticizers for various types of cement. We know that the number of plasticizers added to concrete ranges from 0.1 % to 0.5 % of the total weight of cement.
Here is the list of apparatus required to perform the marsh cone test: a. A conical brass vessel is maintained on a wooden stand with a diameter of 50 cm or 80 cm at its base. b. Stopwatch c. The Mortar mixer to blend the cement paste with the preferred water-cement ratio.
The steps of performing the marsh cone test are as follows: 1.First make a cement paste of 1L with a preferred water-cement ratio by keeping 2 kg of cement to it. 2. While making the cement paste, the blending should be done in the mortar mixer. The mortar mixer is utilized to neglect the formation of a lump at the base of the vessel. 3.You can car...
Marsh test, method for the detection of arsenic, so sensitive that it can be used to detect minute amounts of arsenic in foods (the residue of fruit spray) or in stomach contents. The sample is placed in a flask with arsenic-free zinc and sulfuric acid.
The Marsh test is a highly sensitive method in the detection of arsenic, especially useful in the field of forensic toxicology when arsenic was used as a poison. It was developed by the chemist James Marsh and first published 1836.
A chemical test for arsenic in which hydrochloric acid and zinc are added to the sample, arsine being produced by the nascent hydrogen generated. Gas from the sample is led through a heated glass tube and, if arsine is present, it decomposes to give a brown deposit of arsenic metal.
Using the Marsh model, individual ratios of measured-to-calculated concentrations indicated that measured propofol plasma concentrations were underestimated, especially after induction of anaesthesia. The Schnider and Eleveld models tended to overestimate measured plasma concentration throughout anaesthesia (Fig. 1).
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Sep 1, 2008 · With these requirements in mind, let’s look at three possible solutions, one involving a single branch, two-stage helical gear set. A second solution takes the original gear set and splits the two-stage reduction into two branches, and the third calls for using a two-stage planetary or star epicyclic.
