Selectivity, molecular

The half-electron method can also apply to triplet states. For this calciilatioit. IlyperCheni populates selected molecular orbitals with pairs of half electron s. The final energy is computed by assigning the proper spins. 

Table 1. Hole Mobilities of Selected Molecular and Polymeric Materials ...

Table 2. p-QjCt, and E and Some Hole Mobilities, cm /V s, of Selected Molecular and Polymeric Materials ... 

Synthetic Fuels. Hydrocarbon Hquids made from nonpetroleum sources can be used in steam crackers to produce olefins. Fischer-Tropsch Hquids, oil-shale Hquids, and coal-Hquefaction products are examples (61) (see Fuels, synthetic). Work using Fischer-Tropsch catalysts indicates that olefins can be made directly from synthesis gas—carbon monoxide and hydrogen (62,63). Shape-selective molecular sieves (qv) also are being evaluated (64). 

Pores Even porous membranes can give very high selectivity. Molecular sieve membranes exist that give excellent separation factors for gases. Their commercial scale preparation is a formidable obstacle. At the other extreme, UF,3 separations use Knudsen flow barriers, with aveiy low separation factor. Microfiltration (MF) and iiltrafiltra-tion (UF) membranes are clearly porous, their pores ranging in size from 3 nm to 3 [Lm. Nanofiltration (NF) meiTibranes have smaller pores. 

Because of their selectivity, molecular sieves offer advantages over silica gel, alumina or activated charcoal, especially in their very high affinity for water, polar molecules and unsaturated organic compounds. Their relative efficiency is greatest when the impurity to be removed is present at low concentrations. Thus, at 25° and a relative humidity of 2%, type 5A molecular sieves adsorb 18% by weight of water, whereas for silica gel and alumina the figures are 3.5 and 2.5% respectively. Even at 100° and a relative humidity of 1.3% molecular sieves adsorb about 15% by weight of water. 

TABLE 4. Selected molecular parameters of methyl phenyl sulfone (from gas-phase electron diffraction) and p-methylsulfonylbenzoic acid (from X-ray crystallography)... 

TABLE 5. Selected molecular parameters (A, deg) of 3-bromo-26-thietane 1,1-dioxide in the gas phase37 and in the crystal56... 

For a review, see Stevens, T.S. Watts, W.E. Selected Molecular Rearrangements Van Nostrand-Reinhold Princeton, 1973, p. 192. 

For books, see Mayo, P. de Rearrangements in Ground and Excited States, 3 vols. Academic Press NY, 1980 Stevens, T.S. Watts, W.E. Selected Molecular Rearrangements Van Nostrand-Reinhold Princeton, 1973. For a review of many of these rearrangements, see Collins, C.J. Eastham, J.F. in Patai The Chemistry of the Carbonyl Group, vol. 1 Wiley NY, 1966, p. 761. See also the series Mechanisms of Molecular Migrations. 

Narayanan S. Concepts, principles and applications of selected molecular biology techniques in clinical biochemistry. Adv Clin Chem 1996 32, 1-38. 

Table 2.3. Comparison of the selected molecular parameters for intrazeolitic complexes of TMI...

We will then examine other flexible polymer crystallization instances which may be interpreted, at least qualitatively, in terms of the bundle model. We will concentrate on crystallization occurring through metastable mesophases which develop by quenching polymers like isotactic polypropylene, syndiotactic polypropylene etc. In principle also hexagonal crystallization of highly defective polymers, and order developing in some microphase-separated copolymer systems could be discussed in a similar perspective but these two areas will be treated in future work. A comparison between the bundle approach and pertinent results of selected molecular simulation approaches follows. 

Qi, P. Vermesh, O. Grecu, M. Javey, A. Wang, Q. Dai, H. Peng, S. Cho, K. J. 2003. Toward large arrays of multiplex functionalized carbon nanotube sensors for highly sensitive and selective molecular detection. Nano Lett. 3 347-351. 

MSDW [Mobil selective dewaxing] A catalytic dewaxing process which uses a catalyst containing a shape-selective molecular sieve and a noble metal. 

In this section, we present an application to chemical sensing of the nano-sized HRI-coated LPGs. This time the sPS overlay is used both as HRI material to enhance the sensitivity of the LPG and as a selective molecular sieve to collect... 

Comparison of Selected Molecular Fukui Function and Softness Compliants... 

Selected ion monitoring (SIM) Detection of selected molecular ions or fragments quantitation Low High... 

De Benedetti, P.G., Fanelli, F., Menziani, M.C., Cocchi, M., Testa, R. and Leonardi, A. (1997) Alpha 1-adrenoceptor subtype selectivity molecular modelling and theoretical quantitative structure-affinity relationships. Bioorganic el Medicinal Chemistry, 5, 809-816. 

Though electrophoretic separations were historically first studied in free solutions, more recent developments have extended its application to solid supports, including polyacrylamide, agarose, and starch gels. The purpose of a solid support is to suppress convection current and diffusion so that sharp separations may be retained. In addition, support gels of controlled pore sizes can serve as size-selective molecular sieves to enhance separation - smaller molecules experience less frictional resistance and move faster, while larger molecules move slower. Therefore, separation can be achieved based on molecular size. 

Table 14.1 Selected molecular properties of PAMAM, PPI and PBzE dendrimers- ... 

Table V. Results from Selected Molecular Dynamics Studies of Water Near Hydrophobic Surfaces.

---