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Diffusion nature

The diffuse nature of orexinergic projections is consistent with combined patterns of expression of the two orexin receptors, which is widespread but differential and often complementary within and even outside the CNS. OX2Rs are found primarily in structures attributed to control of sleq)-wake functions, whereas OXIRs are more abundant in limbic structures controlling aspects of feeding, autonomic outflow, energy homeostasis, and to a lesser extent also REM-sleq). [Pg.911]

Most of the data used for compiling such maps have been obtained for the flow of water and air at near atmospheric temperature and pressure, and scaling factors have been introduced to extend their applicability to other systems. However, beating in mind the diffuse nature of the boundaries between the regimes and the relatively minor effect of... [Pg.184]

Leadbetter AJ, Norris EK (1979) Molec Phys 38 669. There are different contributions which give rise to a broadening a of the molecular centre of mass distribution function f(z). The most important are the long-wave layer displacement thermal fluctuations and the individual motions of molecules having a random diffusive nature. The layer displacement amplitude depends on the magnitude of the elastic constants of smectics ... [Pg.237]

The structural chemistry of the actinides is often similar to that of lighter transition metals, such as Zr and Hf, and to that of the lanthanides however, the diffuse nature of the 5/ orbitals leads to some differences and specifically to interesting magnetic and electrical properties. The actinide sulfides are generally isostructural with the selenides, but not with the analogous tellurides. The binary chalcogenides of uranium and thorium have been discussed in detail [66], but the structural... [Pg.31]

The reaction was studied for all coinage metal nanoparticles. In the case of GMEs the rate follows zero-order kinetics with IT for all the coinage metal cases. The observed IT for the Cu catalyzed reaction was maximum but its rate of reduction was found to be minimum. Just the reverse was the case for Au and an intermediate value was obtained for the Ag catalyzed reaction (Figure 7). The adsorption of substrates is driven by chemical interaction between the particle surface and the substrates. Here phe-nolate ions get adsorbed onto the particle surface when present in the aqueous medium. This caused a blue shift of the plasmon band. A strong nucleophile such as NaBH4, because of its diffusive nature and high electron injection capability, transfers electrons to the substrate via metal particles. This helps to overcome the kinetic barrier of the reaction. [Pg.424]

The interfacial zone is by definition the region between the crystallite basal surface and the beginning of isotropy. Due to the conformationally diffuse nature of this region, quantitative contents of the interphase are most often determined by indirect measures. For example, they have been computed as a balance from one of the sum of the fractional contents of pure crystalline and amorphous regions. The analysis of the internal modes region of the Raman spectrum of polyethylene, as detailed in the previous section of this chapter, was used to quantify the content of the interphase region (ab). [Pg.271]

Eutrophication Problems with eutrophication of river basins do not rely on lack of research, but on the effectiveness of the measures that are difficult to quantify. Furthermore, due to the diffuse nature of this key issue, it is also difficult to select appropriate measures. [Pg.414]

These results were taken to indicate that GeCl2 is non-linear in the gas phase. If the diffuse nature of the bands is due to predissociation, then the dissociation energy of the CIGe-Cl bond is less than 64 kcal. [Pg.30]

The quantum mechanical polarizability is calculated using the DFT, with B3P86 (Becke s three-parameter functional [53] with the non-local correlation provided by Perdew [54]). The basis set used for the water molecules is 6-311 + +G. Because of the very diffuse nature of the anion F, the basis set used is the specially designed, and very extensive, fully uncontracted 14s 9p 6d 2f Gaussian-type orbitals [55]. All the QM calculations were made with the Gaussian98 program [56]. [Pg.144]

The changes in the dipole polarizahilities in solution using continuum theories have been questioned hy van Duijnen et al. [67,68]. While most continuum theories yield an increase in the dipole polarizahility, their studies suggest a reduction, compared to the isolated gas phase result. The present F anion case is interesting in this aspect hecause of the diffuse nature of this reference solute system. A considerahle decrease is obtained here and the trend shows similarity with the results for the diffuse anionic atomic system Cl [52]. [Pg.148]

The primary motivation for the development and application of vibrational optical activity lies in the enhanced stereochemical sensitivity that it provides in relation to its two parent spectroscopies, electronic optical activity and ordinary vibrational spectroscopy. Over the past 25 years, optical rotatory dispersion and more recently electronic circular dichroism have provided useful stereochemical information regarding the structure of chiral molecules and polymers in solution however, the detail provided by these spectra has been limited by the broad and diffuse nature of the spectral bands and the difficulty of accurately modeling the spectra theoretically. [Pg.116]

Cooper A.R. and Kingery W.D. (1963) Dissolution in ceramic systems, 1 molecular diffusion, natural convection, and forced convection studies of sapphire dissolution in calcium aluminum silicate. /. Am. Ceram. Soc. 47, 37-43. [Pg.598]

Solid /8-CrPc reacts reversibly with gaseous NO at ambient temperature to give a 1 1 adduct, which reacts with both py and 02 (Scheme 117).596 No structural information is available on the oxidation product of the nitrosyl complex. In contrast to the /3 form, solid ar-CrPc is unreactive towards either 02 or NO, a difference ascribed to the solid-state structures of the two polymorphs.597 Although the distance between the phthalocyanine planes is similar (340 pm), in both cases the metal-metal distance increases from 340 to 480 pm on going from the a to the /3 form. These distances are sufficient to permit access of 02 or NO in the /8 form, while excluding them from the a form. The addition of py to CrPc(NO) causes the NO stretching band in the IR spectrum to intensify and to sharpen considerably. The diffuse nature of this band in CrPc(NO) indicates the presence of a perturbed NO ligand but the introduction of py causes lattice expansion and eliminates the perturbation. [Pg.925]

In sharp contrast to the large number of experimental and computer simulation studies reported in literature, there have been relatively few analytical or model dependent studies on the dynamics of protein hydration layer. A simple phenomenological model, proposed earlier by Nandi and Bagchi [4] explains the observed slow relaxation in the hydration layer in terms of a dynamic equilibrium between the bound and the free states of water molecules within the layer. The slow time scale is the inverse of the rate of bound to free transition. In this model, the transition between the free and bound states occurs by rotation. Recently Mukherjee and Bagchi [14] have numerically solved the space dependent reaction-diffusion model to obtain the probability distribution and the time dependent mean-square displacement (MSD). The model predicts a transition from sub-diffusive to super-diffusive translational behaviour, before it attains a diffusive nature in the long time. However, a microscopic theory of hydration layer dynamics is yet to be fully developed. [Pg.219]

Note that this primitive single-jump model neglects the diffuse nature of the crystal/liquid interface. [Pg.294]

In a later note,203 they conclude that non-vertical transitions are responsible for the V-N band, and the broad diffuse nature of the spectrum in this region could be caused by two states in close proximity which have the same symmetry as the twisted ethylene. A more extensive series of calculations including Cl and the (9,5)->[4,2] DZ basis set augmented by diffuse functions were carried out by Bender et a/.204... [Pg.25]

As one might expect, the Frost model gives rather poor bond quadrupole moments owing to the diffuse nature of spherical gaussian charge distributions. Amos et al, have additionally extended the calculations to second-order bond properties.64... [Pg.88]


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See also in sourсe #XX -- [ Pg.401 ]




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