Other Factors

Deficiency in other nutrients, e.g., minerals, protein, etc., also causes structural changes in tissues. Deficiency of individual amino acids (e.g., tryptophan) produces well-defined histological alteration, and deficiency of certain essential fatty acids, the importance of which was first described by Burr and Burr also results in pathological changes in tissues. In female rats lack of these fatty acids causes cessation of estrus, fetal resorp- 

Persson, Supplement 2, Acta Societ. Medic. Upsaliensis (1953). 

and 22. Sections through the head of a fetal rat of a folic acid-deficient mother. Distortion and deorientation of optic cups may be seen. 

Effects of graded doses of vitamin C on the response of the periosteum of guinea pig femur to an injury inflicted 1 week previously. 

All animals probably harbor bacteria and sometimes protozoans and other primitive organisms in their alimentary tracts this state may be considered normal. The balance maintained by the host and these microorganisms is undoubtedly influenced by the character of the alimentary tract and the food eaten by the host. Therefore, in considering the role of microorganisms in a particular host, reference must repeatedly be made to the physical and chemical state of the food. This being so, it is understandable that different species of animal with different feeding habits should possess fauna and flora that may be characteristic of the species. The feeding habits, however, may not be the only factor concerned, for the environ- 

For a field detector, portability is another important factor to be considered. Portability, or whether the device can be transported, includes any support equipment required for operation. If transport and operation by a single person are considered important, then portability means a lightweight device. In situations where vehicle transport is acceptable or desirable, larger and heavier equipment (which in turn provide better detection and more refined analyses) carried by a vehicle are considered porfable. 

Field defecfors must be transported from place to place by ground, rail, water, and air transport, and are subjected to extreme environmental conditions in storage. Rough handling in emergency situations is to be expected. Therefore, detector durability is another consideration. 

Operator training requirements are another factor to consider. Detector quality is only as good as an operator s understanding of instmment features and functions. Many modem instruments require a certain amount of special training to fully utilize their capabilities. Fortunately, most field detectors are designed to be user friendly very little training is required to operate and maintain them. 

Operation costs should include equipment purchase, maintenance, and consumables costs. Cost comparisons should be based on the cost per analysis per chemical. For example, the purchase price of certain colorimetric detectors may seem relatively low but each analysis will incur additional consumables costs. Thus, the final cost of an operation could be relatively high compared to automatic continuous types of devices due to the cost of required consumables. Thus, although an automatic detector may cost tens of thousands of dollars initially, it does not require large amounts of consumables, it detects a number of chemicals at once, and it has a very long operational life. 

There are other secondary concerns, such as the time required to clean the residual from the previous sample, waste generation, storage effects, maintenance frequency, whether the device can be easily decontaminated, and whether data can 

There are at least three other factors that have a smaller but important effect on the final choice of coordination number symmetry, the softness of the ions, and spatial constraints. 

The reason why the coordination number is 6 and not 7 is discussed in Section 6.4 below. 

In Section 4.5 it was shown that the bonding strengths of soft cations are less well defined than those of hard cations since they are able to form stable compounds with anions having a wider range of anion bonding strengths. Consequently they also display a wider range of coordination numbers. Thus the soft Zn + cation is found in four and six coordination in contrast to the similar, but hard, cation which is usually found only in 6-coordination. Most hard 

Spatial constraints can also influence the coordination number and can often explain, for example, why the same cation can occur with more than one coordination number in the same crystal. However, a full treatment of spatial constraints requires an understanding of crystallographic symmetry, so further discussion is deferred to Part III which deals with the chemistry of extended three-dimensional solids. 

LNAPL recovery projects require careful planning, operation, and management. Some additional factors become important at unforeseen times. Recovery of free product often produces flammable vapors at concentrations that can violate air quality standards if freely released. Vapor treatment should be considered early in the design process. Storage of flammable liquids in appropriate containers is necessary. 

secure operating conditions are sometimes difficult to maintain, especially at locations where staff is not continually present. Safe operations of the site, and protection of workers and neighbors, may represent a significant but necessary expense to the project. 

Organic chemicals dissolved in groundwater originate from a release source, which may be point source (defined leak) or it may emanate from an area source, such as a mass of contaminated soil. Once dissolved, the chemicals disperse into the ground-water by molecular diffusion and advection (combined as dispersion), both of which are influenced by equilibrium distribution relationships with the aquifer materials. 

The presence of polymers, either adsorbed on colloidal particles or free in solution, can lead to other interesting effects. For example, if a high-molecular-weight polymer is present at low concentration, remote segments of a polymer chain may be adsorbed on separate particles, causing them to be drawn together (bridging flocculation). The presence of an excess of non-adsorbed polymer can also result in flocculation (depletion flocculation). These and other special cases will be discussed in Chapter 9. 

Combining the values of Fellgett s and Jacquinot s advantages, FT-IR spectrometers should be about 2000 times more sensitive than grating spectrometers that operate in the mid-infrared. In practice, however, smaller values are found. To understand why this is the case, we must consider other components in these spectrometers. The same types of source are used in both types of instruments, so we will neglect any discussion of this component. This cannot be said of the detector, however. 

A typical value for the NEP of a thermocouple used in a grating spectrometer with a 15-Hz chopper is 1 x 10 W This number increases (i.e., dete- 

The typical NEP of a DTGS detector for a modulation frequency of 15 Hz is 2 X 10 W [i.e., about 20 greater (i.e., worse) than that of a thermocouple]. 

The efficiency of a diffraction grating can approach 85% at the wavelength for which it is optimized. Nonetheless, the efficiency falls off quickly on either side of 

A good description of all the factors contributing to the efficiency of an FT-IR spectrometer has been reported by Mattson [10]. He measured the effect of several different parameters that include beamsplitter efficiency, Fresnel losses at the substrate and compensator plate, reflection losses at the mirrors, radiation obscured by the mounting hardware for the HeNe laser, the emissivity of the source, and losses caused by imperfect optical alignment. He calculated the overall efficiency ( in Eq. 7.8) as being 0.096. This value is in accord with the value of 0.10 used in Section 7.1 to estimate the SNR of a commercial FT-IR spectrometer. 

Sleep apnea has been shown to be a risk factor for glaucoma in some studies (Pearson, 2000). Myopia may be another risk factor for glaucoma (Daubs and Crick, 1981). The relatively thin eye wall and large globe in severely nearsighted people suggest a possible susceptibility to stretching under the influence of lOP. The association between factors such as concurrent cardiovascular disease (Tielsch, 1991) has not been demonstrated consistently. 

In general, the cause of glaucomatous optic neuropathy is unknown. The disease affects the individual axons of the optic nerve, which may die by apoptosis, also known as 

Interleukin-6 (IL-6) is a principal cellular regulatory factor, and also plays a role in bone remodeling. IL-6 exercises its effect by binding to a receptor (IL-6R), which leads to signal transduction and activation of intracellular cascades. Information from studies performed both in vitro and in vivo show IL-6 as an autocrine/paracrine factor of the osteoclasts. Recent studies describe especially increased expression of IL-6R mRNA in the osteoclasts engaged in increased bone resorption. It can be judged that IL-6 itself is in a sophisticated way involved in bone resorption, and that especially the expression of its receptor (IL-6R) correlates with resorption activity of the osteoclasts (LI). 

Establishing the role of these proteins of the HSP class in the process of bone remodeling must be understood as a challenge for further studies (Nl). 

Nitric oxide (NO) is considered to be a factor that participates significantly in bone remodeling, especially as a mediator of cytokines, and their activities in bone tissue. In cell cultures, the presence of NO leads to an increase of activity of alkaline phosphatase, and to an increase of the number of calcified nodules in the primary line of bone osteoblasts (C3). Low NO concentration, on the other hand, led to increased osteoclast formation. Damoulis and Hauschka (Dl) arrived at a similar conclusion the proinflammatory cytokines induce production of NO in various types of cells, including osteoblasts and osteoclasts. It is obvious that each of these cytokines can interfere in the process of bone remodeling independently of the permissive effect of NO. 

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However, there are many other factors to be considered in the choice of reaction path. Some are commercial, such as uncertainties regarding future prices of raw materials and b3q)roducts. Others are technical, such as safety and energy consumption. 

The problem with this approach is obvious. It involves a considerable amount of work to generate a measure of the quality of the sequence, the total vapor load, which is only a guideline. There are many other factors to be considered. Indeed, as we shall see later, when variables such as reactor conversion are optimized, the sequence might well need readdressing. 

Figure 6.29 Furnace stack temperature can be limited by other factors than pinch temperature.

It is clear that, apart from the production regime, other factors may influence the freight values obtained (film type, regeneration quotes, electrolysis unit,. ..). In case of G335SF in combination with STRUCTURIX SILVERFIX, which has a maximum current of 3A and a typical response of 4 A.l/g, I5m of film per day is judged to be the maximum production to meet silver freights below 50 mg/m. ... 

In developing the procedure of testing the features of NDT technological process must be taken into account, particularly, availability of the object for testing, strict characteristics of NDT devices being used and other factors which influence on the accuracy and reliability of measurements. 

Note the presence of the ra prefactor in the absorption spectrum, as in equation (Al.6.87) again its origm is essentially the faster rate of the change of the phase of higher frequency light, which in turn is related to a higher rate of energy absorption. The equivalence between the other factors in equation (Al.6.110) and equation (Al.6.87) under linear response will now be established. 

Often it is possible to resolve vibrational structure of electronic transitions. In this section we will briefly review the symmetry selection rules and other factors controlling the intensity of individual vibronic bands. 

It is only during an evolution (perhaps between sampling points in an FID) that these totals need be divided amongst the various lines in the spectmni. Therefore, one of the factors in the transition probability represents the conversion from preparation to evolution the other factor represents the conversion back from evolution to detection. 

Flere, an underlying matrix, with elements a.p p, sets the probability of attempting a move like F <— F, and the other factor gives the probability of accepting such a move. This scheme only requires a knowledge of the ratio p /iPp ... 

As we shall see later, the limitations imposed by most solvents may prevent us from being able to utilise the very strong basic characteristics of some anions. However, at this point it is more useful to consider other factors affecting the strengths of acids. 

Two factors affect the stability of this orbital. The first is the stabilizing influence of the positively charged nuclei at the center of the AOs. This factor requires that the center of the AO be as close as possible to the nucleus. The other factor is the stabilizing overlap between the two constituent AOs, which requires that they approach each other as closely as possible. The best compromise is probably to shift the center of each AO slightly away from its own nucleus towards the other atom, as shown in figure 7-23a. However, these slightly shifted positions are only correct for this particular MO. Others may require a slight shift in the opposite direction. 

A variant on this procedure produces a first approximation to the molecular mechanics (MM) heat paiameters (Chapters 4 and 5) for C—C and C—H. Instead of atomization energies, the enthalpies of formation of propane and butane (—25.02 and —30.02 kcal mol ) are put directly into the b vector. The results (2.51 kcal mol and —3.76 kcal mol ) are not very good approximations to the heat parameters actually used (2.45 kcal mol and —4.59 kcal mol ) because of other factors to be taken up later, but the calculation illustrates the method and there is rough agreement. 

When the reaction is over, add- concentrated hydrochloric acid to decompose the tsocyanide and pour it away after the odour is no longer discernible. The test is extremely dehcate and will often detect traces of primary amines in secondary and tertiary amines it must therefore be used with due regard to this and other factors. 

The reaction probably must involve two steps, aldolization followed by crotonisation. and depends among other factors on the specific reactivity of the aldehyde and of the methyl, which is influenced both by the nature of the substituents on the ring and bv the nature of the anion (Scheme 35) (57. 58. 657)... 

Sensitizers as well as desensitizers form a reversal oxidoreduction system with silver halides, according to both pH and pAg of the photographic emulsion. But besides the specific influence of the emulsion, the efficiency of a sensitizing dye depends on many other factors such as its adsorption, its spectral absorption, the energetic transfer yield, the dye aggregate to the silver halide, and finally on its desensitizing property in... 

Cyclic conjugation although necessary for aromaticity is not sufficient for it Some other factor or factors must contribute to the special stability of benzene and compounds based on the benzene ring To understand these factors let s return to the molecular orbital description of benzene... 

It IS not possible to tell by inspection whether the a or p pyranose form of a par ticular carbohydrate predominates at equilibrium As just described the p pyranose form IS the major species present m an aqueous solution of d glucose whereas the a pyranose form predominates m a solution of d mannose (Problem 25 8) The relative abundance of a and p pyranose forms m solution depends on two factors The first is solvation of the anomeric hydroxyl group An equatorial OH is less crowded and better solvated by water than an axial one This effect stabilizes the p pyranose form m aqueous solution The other factor called the anomeric effect, involves an electronic interaction between the nng oxygen and the anomeric substituent and preferentially stabilizes the axial OH of the a pyranose form Because the two effects operate m different directions but are com parable m magnitude m aqueous solution the a pyranose form is more abundant for some carbohydrates and the p pyranose form for others... 

Relations which are exact are indicated by an asterisk ( ). Factors in parentheses are also exact. Other factors are within 5 in the last significant figure. 

Two methods have been proposed for the analysis of sulfur in impure samples of pyrite, EeS2. Sulfur can be determined in a direct analysis by oxidizing it to S04 and precipitating as BaS04. An indirect analysis is also possible if the iron is precipitated as Ee(OH)3 and isolated as Ee203. Which of these methods will provide a more sensitive determination for sulfur What other factors should be considered in deciding between these methods ... 

A one-factor-at-a-time optimization is consistent with a commonly held belief that to determine the influence of one factor it is necessary to hold constant all other factors. This is an effective, although not necessarily an efficient, experimental design when the factors are independent. Two factors are considered independent when changing the level of one factor does not influence the effect of changing the other factor s level. Table 14.1 provides an example of two independent factors. When factor B is held at level Bi, changing factor A from level Ai to level A2 increases the response from 40 to 80 thus, the change in response, AR, is... 

After each of the effects is calculated, they are ranked from largest to smallest, without regard to sign, and those factors whose effects are substantially larger than the other factors are identified. The estimated standard deviation for the analysis is given by... 

Under suitable conditions of pressure and other factors, application of a suitable voltage between electrodes immersed in a gas causes a discharge of electric current through the gas. Different... 

Each proton or neutron has an atomic mass close to 1 Da. Neglecting the small electron mass and other factors, the total atomic mass of an element is given by the sum (P + N). 

There is a degeneracy factor of two associated with a n orbital compared with the nondegeneracy of a (7 orbital, so that it might be expected that the integrated intensity of the second band system would be twice that of each of the other two. However, although the second band system is the most intense, other factors affect the relative intensities so that they are only an approximate guide to orbital degeneracies. 

Several other factors must also be considered with respect to heating conditions. At the front end of a vehicle, ie, at the nosetip, the heating rate is most severe, generally decreasing toward the aft end of the vehicle in instances of laminar flow. Because of this variation in heating conditions, the nosetip... 

Another type of experiment to measure separately from other factors consists of saturating packings made from porous materials using a volatile... 

Little is known of the market for acetyl chloride. The production and sales are beUeved to be small, but may have potential for very large scale-up. The total U.S. market may amount to only 500 t annually. Acetyl chloride must be shipped in polyethylene-lined dmms having capacities of only 220 L it must be labeled as a corrosive substance. Acetyl chloride generated captively from purchased raw materials probably has a unit value of no more than 0.92—0.95/kg. Shipping costs and other factors set the price at about 3/kg for the commercial trade. 

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