Absorbance definition

The combination of Beer-Lambert s law and the absorbance definition tells us that mathematically for monochromatic radiation both the Napierian and decadic absorbance of a solution consisting of a transparent solvent containing a solute are a linear function of the following factors ... 

Several additional terms related to the absorption of x-radiation require definition energy of a x-ray photon is properly represented in joules but more conveniently reported in eV fluence is the sum of the energy in a unit area intensity or flux is the fluence per unit time and the exposure is a measure of the number of ions produced in a mass of gas. The unit of exposure in medicine is the Rn ntgen, R, defined as the quantity of radiation required to produce 2.58 x C/kg of air. The absorbed dose for a tissue is a measure of energy dissipated per unit mass. The measure of absorbed dose most... 

Tb allium, which does not occur naturaHy in normal tissue, is not essential to mammals but does accumulate in the human body. Levels as low as 0.5 mg/100 g of tissue suggest thallium intoxication. Based on industrial experience, 0.10 mg /m of thallium in air is considered safe for a 40-h work week (37). The lethal dose for humans is not definitely known, but 1 g of absorbed thallium is considered sufficient to kHl an adult and 10 mg/kg body weight has been fatal to children. In severe cases of poisoning, death does not occur earlier than 8—10 d but most frequently in 10—12 d. Tb allium excretion is slow and prolonged. For example, tb allium is present in the feces 35 d after exposure and persists in the urine for up to three months. 

Tray Efficiencies in Plate Absorbers and Strippers Compn-tations of the nnmber of theoretical plates N assnme that the hqnia on each plate is completely mixed and that the vapor leaving the plate is in eqnihbrinm with the liqnid. In actnal practice a condition of complete eqnihbrinm cannot exist since interphase mass transfer reqnires a finite driving-force difference. This leads to the definition of an overall plate efficiency... 

Is it likely to eause skin eontamination or be absorbed through the skin (NB some materials have a definite Sk notation in EH 40.)... 

The indolinol character of eseretholemethine is indicated by the fact that the methiodide on treatment with picric acid yields a diquaternary pierate (m.p. 170°) with the loss of the hydroxyl group. More definite proof is afforded by the oxidation of eseretholemethine with ammoniaeal silver nitrate or potassium ferricyanide, when a dehydroeseretholemethine (oxyeseretholemethine of Polonovski), pierate, m.p. 199°, is produced which is assumed to have formula (VI), since on exhaustive methylation it yields trimethylamine and an unsaturated product (deep-red pierate, m.p. 103°), which absorbs two atoms of hydrogen, forming 5-ethoxy-l 8-dimethyl-S-ethyl-2-indolinone (VII), colourless cubes, m.p. 68°. The... 

A uniform definition of a failure and a method of classifying failures is essential if data from different sources are to be compared. The anatomy of a failure includes the initiating or root cause of a failure that is propagated by contributory causes and results in a failure mode—the effect by which a failure occurs or is observed. Modes include failure to operate, no output, failure to alarm on demand. The end result of a failure sequence is the failure effect, such as no fluid is pumped to the absorber, or a tank overflows. As discussed in Appendix A of IEEE Std. 500-1984, only the equipment failure mode is relevant for data that are needed in a CPQRA. The failure model used in this book is based upon those in the IEEE publication and IPRDS. ... 

Buffers are solutions that tend to resist changes in their pH as acid or base is added. Typically, a buffer system is composed of a weak acid and its conjugate base. A solution of a weak acid that has a pH nearly equal to its by definition contains an amount of the conjugate base nearly equivalent to the weak acid. Note that in this region, the titration curve is relatively flat (Figure 2.15). Addition of H then has little effect because it is absorbed by the following reaction ... 

Such binary borides (p. 145), carbides (p. 297) and nitrides (p. 417) as are formed have been referred to already. The ability of the metals to absorb molecular hydrogen has also been alluded to above. While the existence of definite hydrides of nickel and platinum is in doubt the... 

Aufnahme-fahigkeit, /. absorbability, absorptivity, absorbing power capacity. -ge-Bchwindigkeit, /. absorption rate, -kolbeu, m. absorption flask, -pipette,/, a pipet calibrated to take up a definite volume. Cf. Ausflusspipette. -vermogen, n. absorptive power. 

It must be emphasised that the heat q which appears in the definition of entropy (equation 20.137) is always that absorbed (or evolved) when the process is conducted reversibly. If the process is conducted irreversibly and the heat absorbed is q, then q will be less than q, and q/T will be less than AS the entropy change (equation 20.137). It follows that if an irreversible process takes place between the temperatures Tj and 7 , and has the same heat intake q at the higher temperature 7 2 as the corresponding reversible process, the efficiency of the former must be less than that of the latter, i.e. 

The more dense, more mature peas sink and are drawn off near the bottom of the separator, while the less dense, less mature peas float and are carried off at the top. During the process the peas absorb salt, and unless it is removed by thorough washing enough may be retained to make the product objectionable to the taste. In a packing specification it is necessary to state the amount of salt that will be tolerated. Available methods for the determination of salt are not applicable to production-line control. One which is sufficiently simple and rapid for this purpose is definitely needed. 

The variation of specific heat with temperature was discovered by Dulong and Petit in 1819. It explains why so many different heat units exist (cf. 5), and requires the definition of specific heat to be so framed as to allow for this variation. For this purpose we replace the finite changes by infinitesimal ones. If SQ units of heat are absorbed when unit mass of a substance is raised in temperature from 6— SO) to 0- - SO) underspecified conditions, the true specific heat at the temperature 0 is ... 

Definition.—The heat absorbed in producing a change of physical state or chemical composition of a system, at constant temperature and pressure, is called the latent heat of the given transition, and is measured by the number of calories absorbed during the transition of unit mass of the substance from the initial to the final state. 

Let us consider a mass m of solid solute, and a mass M of solvent, brought together in a calorimeter. When the whole has passed into a homogeneous solution at the original temperature, a quantity of heat Q will have been absorbed. We now set, by wTay of definition ... 

The first definite production of plutonium metal was made in November, 1943 by Baumbach and coworkers (1958). Approximately 35 micrograms of PuFi in a small thoria crucible in a high vacuum was reacted with barium metal at 1400 C to yield plutonium metal. The metal was found to have a silvery lustre, a density of about 16 grams j>er cubic centimeter and it rapidly absorbed hydrogen at about 210 C to form a black powder subsequently identified as PUH3 (a proof that metal had been produced). 

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