MORE study

Apparently a negative AP with Q < 90° can be found for particular pore geometries [53]. A different type of water repellency is desired to prevent the deterioration of blacktop roads consisting of crushed rock coated with bituminous materials. Here the problem is that water tends to spread into the stone-oil interface, detaching the aggregate from its binder [54]. No entirely satisfactory solution has been found, although various detergent-type additives have been found to help. Much more study of the problem is needed. 

Detailed analyses of the above experiments suggest that the apparent steps in k E) may not arise from quantized transition state energy levels [110.111]. Transition state models used to interpret the ketene and acetaldehyde dissociation experiments are not consistent with the results of high-level ab initio calculations [110.111]. The steps observed for NO2 dissociation may originate from the opening of electronically excited dissociation chaimels [107.108]. It is also of interest that RRKM-like steps in k E) are not found from detailed quantum dynamical calculations of unimolecular dissociation [91.101.102.112]. More studies are needed of unimolecular reactions near tln-eshold to detennine whether tiiere are actual quantized transition states and steps in k E) and, if not, what is the origin of the apparent steps in the above measurements of k E). 

The first observation of the enantioselective properties of an albumin was made in 1958 (28) when it was discovered that the affinity for L-tryptophan exceeded that of the D-enantiomer by a factor of approximately 100. This led to more studies in 1973 of the separation of DL-tryptophan [54-12-6] C22H22N2O2, on BSA immobilized to Sepharose (29). After extensive investigation of the chromatographic behavior of numerous racemic compounds under different mobile-phase conditions, a BSA-SILICA hplc column (Resolvosil-R-BSA, Macherey-Nagel GmvH, Duren, Germany) was... 

It is not surprising that it is difficult to insert lithium between parallel layers which are randomly stacked. When lithium intercalates between AB stacked layers, a shift to AA stacking occurs [26]. It is likely that the turbostratically stacked layers are pinned by defects (which can only be removed near 2300°C ) preventing the rotation or translation to AA stacking. Thus, we can understand why varies as 372(1-P), the fraction of layers with AB registered stacking. More studies of the details of the voltage profiles in Fig. 7 can be found elsewhere [6,7,27]. 

Carbon nanotubes were first thought of as perfeet seamless eylindrieal graphene sheets —a defeet-free strueture. However, with time and as more studies have been undertaken, it is elear that nanotubes are not neeessarily that perfeet this issue is not simple bc-eause of a variety of seemingly eontradictory observations. The issue is further eomplicated by the faet that the quality of a nanotube sample depends very mueh on the type of maehine used to prepare it[l]. Although nanotubes have been available in large quantities sinee 1992[2], it is only recently that a purification method was found[3]. So, it is now possible to undertake various accurate property measurements of nanotubes. However, for those measurements to be meaningful, the presence and role of defeets must be elearly understood. 

Expansion must always be kept in mind. The question of multiplying the number of units or increasing the size of the prevailing unit or units merits more study than can be given here. It suffices to say that one must exercise engineering Judgment. 

As can be seen from the survey, only a limited number of alkyl pyrroles are polymerized, actually dimerized, by acid in ether or in water. The dimerizable pyrroles include all those which have free adjacent a- and jS-positions, that is 2- and 3-methyl-, 2-isopropyl-, and 2,3-dimethyl-pyrrole. It must be repeated that no homogeneous product has yet been obtained from 3-methylpyrrole, and this reaction deserves more study. 

Another natural polymer that needs a fresh look into its structure and properties is bitumen [123], also called asphaltines, that are used in highway construction. Although a petroleum by-product, it is a naturally existing polymer. It primarily consists of polynuclear aromatic and cyclocaliphatic ring systems and possesses a lamellar-type structure. It is a potential material that requires more study, and high-performance materials such as liquid crystalline polymer (LCP) could be made from it. 

A wide variety of complexes are formed by both metals in the +2 oxidation state indeed, it is the most important one for palladium. The complexes can be cationic, neutral or anionic. Both Pd2+ and Pt2+ are soft acids so that many stable complexes are formed with S or P as donor atoms but few with O-donors, though there are important ammines. There are pronounced similarities between corresponding palladium and platinum complexes the latter are more studied (and less labile). 

Hence, many results are contradictory and much more studies are needed. These studies must be carried out using well-defined conditions and particularly low concentrations of the reactive groups. 

Of the two classes, the sulfones have received more study, but there is enough information on the sulfoxides to provide a meaningful comparison between them. Such a comparison is made more complete by including the corresponding sulfides and indeed the sulfone/sulfoxide/sulfide structural variations will be one of the central considerations of our treatment. 

It is rather surprising that more studies in this area have not been reported, especially since the yield in the case of diphenyl sulphoxide oxidation is good and the product is easily separable from other materials formed in the electrochemical cell. Presumably more reports will be forthcoming in the next few years, especially for the oxidation of aryl sulphoxides. 

Of the possible substituting ions, COi ion is by far the most important followed by Na, S04 and Mg. The most common form of natural apatite in sedimentary rocks is francolite, a substituted form of carbonate fluorapatite deposited in marine systems. The substitution of col ior>s into the mineral lattice has a substantial effect on apatite solubility (Jahnke, 1984). More studies are required, however, before the effects of all substituting ions are imderstood and an accurate assessment of the solubility of complex, natural apatites can be made. 

Although more studies have been devoted to the mechanism of the acylation of amines with carboxylic esters than with other reagents, the mechanistic details are not yet entirely clear.In its broad outlines, the mechanism appears to be essentially Bac2. ° Under the normal basic conditions, the reaction is general base... 

Clearly, more studies are needed to delineate more precisely the phenomenology of inhalant use disorders, including the phenomenology of anesthetic... 

Exposures of Children. More studies are needed to assess the exposures of children living in agricultural areas to methyl parathion residues in air, soil, or water. More studies are also needed to assess the exposures of children in the general population to residues of methyl parathion that might be present in food, milk, or water, or on contaminated clothing and skin from occupationally exposed household members. 

The heat loss to the melting polymer was assumed (for a first order approximation) to be negligible compared to the heat loss by convection. This is one area of the model which could profit from more study to determine the exact magnitude of energy exchange with the polymer. 

Although more studies need to be performed to study the scope and generality of this system, the use of amine hydrochloride salts as initiators for controlled NCA polymerizations shows tremendous promise. Fast, reversible deactivation of a reactive species to obtain controlled polymerization is a proven concept in polymer chemistry, and this system can be compared to the persistent radical effect employed in all controlled radical polymerization strategies [37]. Like those systems, success of this method requires a carefully controlled matching of the... 

The anxiety disorders are common and surprisingly disabling conditions. Studies on the health economics of generalized anxiety disorder, panic disorder, social anxiety disorders and obsessive compulsive disorder document the cost to the individual and to society. Attention has focused on the major psychiatric disorders such as depression, schizophrenia and the dementias. Studies suggest that many anxiety disorders are of early onset and too often chronic they are quite common and impose a heavy burden on society. More studies will be needed to discern the fine grain in the survey material and to identify more precisely the location and type of societal costs. These factors will vary from country to country, from district to district, between men and women and between various age groups. 

More studies are required to determine if certain subgroups (large vessel atherothrombosis or patients perceived to be at high risk of recurrent embolism) may benefit from urgent anticoagulation. 

A study in Massachusetts found that exposure was associated with leukemia in children. In studies with people, there are many factors that are not fully understood. More studies need to be done to establish the relationship between exposure to trichloroethylene and cancer. 

A regular fine structure causing maximal hydrogen bonding between the molecules reduces the possibility of reversible processes and therefore reduces the gel-forming properties of the compound. Other polysaccharides with different types of monomers or with branched chain structures can be treated in a similar manner. However, much more study of their fine structure and the accessibility of their functional groups is necessary. 

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