Secondary Sampling System

Back-up batteries and battery charging equipment Condensate chemical dosing equipment Various tanks for storing chemicals Component cooling water pumps and heat exchangers Power supply for each reactor coolant piunp s variable-speed drive Secondary sampling system Annex Building... 

The secondary sampling system delivers representative samples of fluids from secondary systems to sample analyser packages. 

No design requirements associated with maintaining safety functions are placed on the secondary sampling system. 

From these results it can be postulated that for oxidic glasses a fixed proportion of sputtered secondary neutrals is emitted in an excited state. Such linearities can only be determined for similar matrices, which limits the use of D-factors to sample systems similar to the reference sample system used for the D-factor determination. 

Other designations for samples are bulk sample, primary sample, secondary sample, subsample, laboratory sample, and test sample. These terms are used when a sample of a bulk system is divided, possibly a number of times, before actually used in an analysis. For example, a water sample from a well... 

A bulk sample is the original undivided sample that was taken directly from the bulk system being characterized. A primary sample is the same as a bulk sample. A secondary sample (also subsample) is a part of the primary sample taken to the next step. A laboratory sample is a sample taken to a laboratory for analysis. The laboratory sample could be a primary sample or a subsample. A test sample is that part of a laboratory sample actually measured out for the method used. 

Other designations for samples are bulk sample, primary sample, secondary sample, subsample, laboratory sample, and test sample. These terms are used when a sample of a bulk system is divided, possibly a number of times, before actually being used in an analysis. For example, a water sample from a well may be collected in a large bottle (bulk sample or primary sample), from which a smaller sample is acquired by pouring into a vial to be taken into the laboratory (secondary sample, subsample, or laboratory sample), then poured into a beaker (another secondary sample or subsample), before a portion is finally carefully measured into a flask (test sample) and diluted to make the sample solution. 

Three questions concerning ultrastabilization remain outstanding. They regard the precise mechanism of A1 removal, the nature of the intermediate defect structure (both are depicted schematically in Fig. 38), and the origin of the silicon needed for framework reconstruction. Gas sorption studies (172) indicate that materials prepared in a manner similar to that for sample 4 in ref. 163 (see above) contain a secondary mesopore system with pore radii in the range IS-19 A, suggesting that tetrahedral sites are reconstituted with silicon that, contrary to earlier speculations, does not come only from the surface or from amorphous parts of the sample, but also from its bulk, which may involve the elimination of the entire sodalite cages. 

Multidimensional (or coupled) column chromatography is a technique in which fractions from a separation system are selectively transferred to one or more secondary separating systems to increase resolution and sensitivity, and/or to reduce analysis time. The application of secondary columns is illustrated schematically in Figure 8.1. The smaller the AtT value applied, then the greater is the resolution and number of runs needed to check a certain portion of the sample (5). 

Should any iron(II) reach the anode, it also would be oxidized and thus not require the chemical reaction of Eq. (4.13) to bring about oxidation, but this would not in any way cause an error in the titration. This method is equivalent to the constant-rate addition of titrants from a burette. However, in place of a burette the titrant is electrochemically generated in the solution at a constant rate that is directly proportional to the constant current. For accurate results to be obtained the electrode reaction must occur with 100% current efficiency (i.e., without any side reactions that involve solvent or other materials that would not be effective in the secondary reaction). In the method of coulometric titrations the material that chemically reacts with the sample system is referred to as an electrochemical intermediate [the cerium(III)/cerium(IV) couple is the electrochemical intermediate for the titration of iron(II)]. Because one faraday of electrolysis current is equivalent to one gram-equivalent (g-equiv) of titrant, the coulometric titration method is extremely sensitive relative to conventional titration procedures. This becomes obvious when it is recognized that there are 96,485 coulombs (C) per faraday. Thus, 1 mA of current flowing for 1 second represents approximately 10-8 g-equiv of titrant. 

The principles, sampling systems, control of the measuring device and application of MS for bioprocesses have been summarized by Heinzle [157,158] and Heinzle and Reuss [162]. Samples are introduced into a vacuum (< 10 5 bar) via a capillary (heated, stainless steel or fused silica, 0.3 x 1000 mm or longer) or a direct membrane inlet, for example, silicon or Teflon [72,412]. Electron impact ionization with high energy (approx. 70 eV) causes (undesired) extensive fragmentation but is commonly applied. Mass separation can be obtained either by quadrupole or magnetic instruments and the detection should be performed by (fast and sensitive) secondary electron multipliers rather than (slower and less sensitive) Faraday cups (Fig. 21). 

In all gas analysis systems, precautions have to be taken against, or allowance made for, the condensation of vapours in the sampling system and/or the occurrence of secondary reactions between gaseous primary products, sometimes catalyzed by the surfaces of the reaction vessel or sampling system. 

Secondary sampling port/valves should be installed on various circulating systems. 

The nitrogen adsorption isotherms of the H(3 zeolite and the Ni/H(3-CE samples (Fig. 2) are, as expected, very similar. In the sample prepared by DP, the presence of a hysteresis caused by the formation of a secondary porous system is evidenced in the Ni/H 32 and Ni/Hp4. The shape of the newly formed hysteresis suggests the formation of a laminar type porous structure [21, 22], possibly nickel phyllosilicates. 

It is very likely that the re-combined, primary sample taken from the whole is going to be too large for most powder tests and it, therefore, needs to be sub-divided into secondary or even tertiary sub-samples. This sub-division may be built into the primary sampling system or it may be achieved with a separate sample divider. Allen1 reviewed and tested most methods available for sample splitting and found the one based on the spinning riffler to be the best. 

As was mentioned earlier, the primary sampling system can be operated either in intervals of constant time or constant mass. The constant mass option makes the design and operation of the secondary, subdivision system simpler. It requires a continuous weighing system, like a belt scale, installed near the primary cutter, preferably before it. This monitors the mass flux of the solids conveyed and adjusts the speed of the primary cutter before each cut this generates a primary increment of constant mass, thus preventing collection of excessive amounts which would overload the secondary system and yet always more than the minimum amount specified for the top size if the handling rate is low. 

A HS gas analysis method for the determination of volatile hydrocarbons in sealed containers was described by Loliger (1990). The experimental setup consists of a gas chromatograph equipped with a gas sampling valve, a vacuum pump and a manometer. The sampling system is evacuated to c. 1 mbar, the tin is punctured by a stainless steel plunger, the gas is left to reach equilibrium and a HS sample is subsequently transferred by means of the valve to a column packed with activated alumina. This system allows estimation of Ci-C6 hydrocarbons, which represents final and stable secondary oxidation products, and was applied to various food systems ranging from oils and emulsions to frozen meats and dehydrated cereals, potatoes and milk. 

Mesoporous ZSM-5-S and ZSM-5-M samples prepared by using ordered mesoporous carbon (CMK-3) and disordered carbon rods (C-MCM l) as the hard template, respectively, were compared with the conventional ZSM-5-C in methane aromatization [67] The Mo-ZSM-5-S and Mo-ZSM-5-M catalysts showed similar conversions of methane, but higher yields of aromatics compared with Mo-ZSM-5-C. The mesoporous catalysts were also more stable than Mo-ZSM-5-C. The formation of the secondary mesoporous system within the zeoUte crystal, which may lead to easier access to the active sites for reactants and be favorable for the diffusion of larger molecules formed in the microporous channels during the methane aromatization reaction, account for the better stability of the mesoporous systems. 

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