Low-temperature phase transformation in Li-10 at. % Mg

It is not known whether impaired hematopoiesis noted during human immunodeficiency virus (HIV) infection results from infection of stem/progenitor cells or of cells of the bone marrow microenvironment. Normal adherent primary stromal layers were exposed to HIV to determine which of this mixture of endothelial cells, fibroblasts, and macrophages are susceptible to the virus. Viral p24 in supernatants was noted with monocytotropic HIV-1Ada, HIV-1Ba-L, and HIV-1JR-FL but not with lymphotropic HIV-1LAI nor HIV-1MN strain, and only stromal macrophages expressed the viral antigens. Coculture of the layers with PHA-activated normal lymphocytes failed to rescue lymphotropic virus. No p24 was produced when macrophage-depleted stromal cells were exposed to either HIV-1Ba-L or HIV-1LAI; proviral DNA was then amplified by PCR in cells exposed to either virus, though coculture with lymphocytes rescued only HIV-1Ba-L. Altogether, these data indicate that macrophages are the major targets of HIV in cultured stromal layers. As virus replication in macrophages did not affect the profile of major cytokines involved in regulating hematopoiesis, HIV infection could alter hematopoiesis by other as yet unspecified mechanisms.     

New ceramer high optical abrasion resistant transparent coating materials based on functionalized melamine and a tris(m-aminophenyl)phosphine oxide compound

Summary The synthesis of new high optical abrasion resistance coating materials has been undertaken by functionalizing melamine and tris(m-aminophenyl)phosphine oxide with a triethoxysilane containing reagent. These highly functionalized compounds have been used for coating a bis-phenol-A polycarbonate substrate by the sol-gel method. Preliminary data shows the abrasion resistance of the polymer substrate is considerably improved when it is coated by these optically clear materials.     

Afterburner [network-independent card for protocols]

Many current implementations of protocols such as the Transmission Control Protocol/Internet Protocol (TCP/IP) are inefficient because data are often accessed more frequently than necessary. Three techniques that reduce the need for memory bandwidth are proposed. The techniques are copy-on-write, page remapping, and single-copy. Afterburner, a network-independent card that provides the services that are necessary for a single-copy protocol stack, is described. The card has 1 MByte of local buffers and provides a simple interface to a variety of network link adapters, including HIPPI and asynchronous transfer mode (ATM). Afterburner can support transfers to and from the link adapter card at rates up to 1 Gbit/s. An implementation of TCP/IP that uses the features provided by Afterburner to reduce the movement of data to a single copy is discussed. Measurements of the end-to-end performance of Afterburner and the single-copy implementation of TCP/IP are presented     

Solubilization of Glibenclamide with β-Cyclodextrin & its Derivatives

Gilbenclamide, a widely used potent hypoglycaemic agent was solubllized using β -Cyclodextrin and β -Cyclodextrin derivatives. Complexes were prepared by kneading method in a molar ratio of 1:1 of the drug and the cyclodextrlns respectively. The Glibenclamide β -Cyelocextrin complex was characterized and evaluated by I.R. studies, Differential Scanning Calorimotry 6 X-ray diffractometry. The in-vitro dissolution rates of drug from inclusion complexes of β Cyclodextrins and its derivatives were compared. A significant Improvement In dissolution lor, rates of Gllbenclamide was observed with Inclusion complexes of all the Cyclodextrins. However, the solubilizing effect was more in case of β-Cyclodextrin derivatives.     

An improved Gaussian approximation for probability of bit-erroranalysis of asynchronous bandlimited DS-CDMA systems with BPSK spreading

This paper analyzes probability of bit-error (P_e) performance of asynchronous bandlimited direct-sequence code-division multiple-access systems with binary phase-shift keying spreading. The two present methods of P_e analysis under bandwidth-efficient pulse shaping: the often-cited standard Gaussian approximation and the characteristic function (CF) method suffer from either a low accuracy in regions of low P_e (< 10^-3) or a prohibitively large computational complexity. The paper presents an alternate method of P_e analysis with moderate computational complexity and high accuracy based on a key observation. A sequence of chip decision statistics (whose sum yields a bit statistic) forms a stationary, m-dependent sequence when conditioned on the chip delay and phase offset of each interfering signal. This observation permits the generalization of the improved Gaussian approximation previously derived for the rectangular pulse and the derivation of a numerically efficient approximation based on the CF method. Numerical examples of systems using the square-root raised-cosine and IS-95 pulses illustrate THE P _e performance, user capacity and the accuracy of the proposed method     

UNIDIRECTIOX4L CUSS FIBRE DRYING KINETICS

The paper presents the results of research in the convection drying of unidirectional glass fibre bobbins on the basis of which the relations are suggested required to calculate the process of drying in the design of drying equipment.     

On the reliability of computer predictions of the geomechanical behaviour of rock-salt

Geomechanical aspects of the storage of radioactive waste in salt formations have been studied extensively using finite element methods over the last 20 years. In consequence a range of computer programs and associated modelling techniques have been assembled. The paper is based on a benchmark exercise to compare the predictive abilities of a number of these programs and highlights the difficulties of making reliable a-priori estimates of long term behaviour.     

Wear in check valves due to flow induced motion

Experiments showing the frequency and amplitude of the flow induced motion of the gate for a 2- and a 4-in. swing check valve have been performed. The gate motion is due to turbulence in approach flow. We have found the dominant turbulent frequency of the approach flow is about half the natural frequency of the valves. The valves appear to be almost critically damped. Because of this, the valves respond almost as they would to a static force of the magnitude characteristic of the turbulent fluctuation in the flow. Both the dimensionless exciting force and the damping ratio have been found to be independent of valve size so the above statements are true for larger valves also. The recommended valve oscillation amplitudes and frequencies are used to calculate the wear at the shaft and at the stop. For an unpegged check valve, such as one of the 10-in. valves which was used at the San Onofre Nuclear Generation Station, it was found that shaft bearing wear would amount to 0.27 in.³/year and stop wear to 0.03 in.³/year.