Interpenetrating polymer networks based on nitrile rubber and metal methacrylates

Interpenetrating polymer networks (IPNs) based on nitrile rubber (NBR) as first component and zinc dimethacrylate (ZnDMA), aluminum trimethacrylate (AlTMA), or zirconium tetramethacrylates (ZrTeMA) as second component were synthesized. Sequential IPNs (SeqIPN) were formed by two routes such as compression molding (CM) and swelling/curing (SC). The IPNs were found to have superior properties compared to metal oxide/hydroxide‐filled NBR. Tensile strength has increased to a large extent while maintaining appreciable elongation. Total crosslink density (covalent and ionic) was found to increase in the order NBR/metal oxide or hydroxide < SeqIPN(CM route) < SeqIPN (SC route). IPNs are found to retain high storage modulus even in the rubbery region. It is observed that change of technique for IPN formation has drastically changed the modulus of the present system. Decrease in tan δ value and inward shifting of peaks were observed because of IPN formation. Morphology of SeqIPN by SC process was found to be more uniform compared to others. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 2542–2548, 2006     

Effect of calcination temperature and heating rate on the optical properties and reactivity of rice husk ash

Rice husk is an agricultural waste and its conversion to value added products makes it a secondary resource material. On heating, rice husk gives ash with >90% by weight of silica with some carbon and other nonmetallic and metallic impurities. Silica of high purity, chemical reactivity and white color can be produced from rice husk by controlling the heating conditions and this material finds wide industrial applications. Properties of the ash depend upon various pretreatments and calcination conditions. The present work deals with the investigation on a rice husk sample from the state of Andhra Pradesh in India. The raw husk and its acid treated form were calcined at different conditions such as temperatures, soaking periods and heating rates. Lime reactivity, surface area, brightness and color values of the ash samples were measured. The high potassium content in the husk has been found to inhibit the carbon removal during ashing which affected the color as well as reactivity of the ash. Properties of the ash samples from the untreated and acid treated husk have been compared and correlated with the formation conditions.     

Identification of novel transmembrane gene sequence and its use for cell-surface targeting of beta subunit of human chorionic gonadotropin

We identified a 685-nucleotide gene fragment that codes for the transmembrane and cytoplasmic domains of glycoprotein of the LEP strain rabies virus and carried out experiments designed to express a novel fusion protein on the cell surface. The cDNA encoding the membrane anchor sequence was fused in the correct reading frame to the 3' end of the cDNA encoding the beta subunit of human chorionic gonadotropin (beta(h)CG), a secretory glycoprotein that is used as an antigen for a contraceptive vaccine being developed in our laboratory. The fusion gene cassette was placed under the control of a vaccinia virus early promoter and cloned in a host-restricted fowlpox viral vector. The recombinants, when used to infect mammalian cells that do not allow the replication of fowlpox virus, expressed the N-terminal 135 amino acid residues of beta(h)CG anchored in the cell membrane by the 75-amino acid C-terminal sequence derived from rabies virus glycoprotein. This hybrid protein is correctly processed post-translationally and transported efficiently to the plasma membrane of non-permissive cells such that the anchored beta(h)CG molecule retains the correctly folded native antigenic epitope(s).     

Integrated directional couplers with photodetectors by hydridevapour phase epitaxy

The hydride vapour-phase-epitaxial crystal growth technique has been used to realise integrated waveguide-photodetectors and, for the first time, integrated directional coupler-photodetectors for detection in the 1.3 μm to 1.55 μm wavelength range. The GaInAsP waveguides which formed the directional couplers had propagation losses of 2±0.5 dB/cm and more than 90% of the guided light was coupled into the photodetectors. The directional couplers were symmetric with respect to the launch port and had 3 dB coupling lengths of about 1.45 mm     

Reliability analysis of multistorey frames

The paper presents a parametric study of different independent variables to study their effect on final rotations, sidesway, end moments and reactions. It is found that while there is practically no effect on final end moments and reactions, the displacements varied. Later, the distribution function of different dependent variables; namely rotation, sidesway, end moment and reaction is obtained. The estimation of these dependent variables is also made. It is found that the maximum variation from the mean value is in the case of rotation. The minimum variation is found to be in the case of vertical reactions.     

Quadratic Approximation to Linear Loss Integrals for Some Non-Normal Distributions

This paper develops an estimate of the linear loss integral for three distributions: Student's t, Beta, and Negative Binomial. The proposed estimating equation is a multivariable nonlinear function which is developed in two stages. First, the integral is approximated by a quadratic function of the right-tail probability. Next, the estimated coefficients of the quadratic equation are regressed on the parameters of the distribution. Limitations, extensions, and applications of the estimates are fully discussed, and tables are provided to display sample accuracy.     

Protein and gossypol extractability from cottonseed flour

The extractability of protein and free-gossypol from fully gossypolised cottonseed flour was investigated. The various parameters studied include (i) effect of pH (ii) effect of salts and (iii) the combined effect of pH and salts. The results indicated that it is possible to obtain a protein isolate free from free-gossypol by alkaline extraction at pH values of 9 and 10. Highest protein extraction (57%), highest protein recovery (96%) and highest protein content of the precipitate (75%) occurred at pH 10. In general, dilute aqueous electrolytes did not accomplish significantly higher extracta-bilities although they resulted in comparatively lower free-gossypol contents in the protein precipitate. However, with 1.0m CaCl2 protein extraction was 75% but both protein recovery (61%) and the protein content of the precipitate (61%) was comparatively low. Extraction in the presence of salts and alkali did not improve protein extractability and gave a protein isolate high in free-gossypol content.     

Inventory control for lognormal demand

This paper develops an explicit but approximate solution to the reorder point inventory model for lognormal lead time demand. Solution to the same model under a constraint on fraction of demands backordered is also obtained. Both solutions are extended to cover the three- and four-parameter lognormal families, and the methods are illustrated with hypothetical data.     

High field conduction in a double layer polymeric photoreceptor

Xerographic characteristics such as (i) maximum acceptance potential, (ii) quantum efficiency, (iii) reciprocity nature and (iv) dynamic law have been evaluated for a polymeric double layer system. The double layer consists of poly(9-vinyl anthracene) base on aluminium substrate, having an over-layer of 1.0μm poly(n-vinyl carbazole). It was found to have good xerographic properties and can be used effectively in xerography.