Antifertility agents: 5. Synthesis of 2,2-dimethyl-3,4-diphenyl-5,6-benzochromenes and 1,1-dimethyl-2,3-diphenylphenalenes

3-phenyl-4-(p-(beta-pyrrolidinoethoxy)- HCl, HC1, 2,2-dimethyl-3-phenyl-4(p-(beta-pyrrolidinoethoxy) -phenyl)-5,6-benzochromene-HCl, 1,1-dimethyl-2,3-diphenyl-4-(beta-pyrrolidinoethoxy) -phenalene, and 1,1-dimethyl-2-phenyl-3-(p-(beta-pyrrolidinoethoxy) -phenyl)-4-beta-pyrrolidinoethoxy phenalene were synthesized from 5,6-benzocoumarins. When tested in rats at 10 mc/kg orally for 5 days for antiimplantation activity, they were ineffective.     

Polymerization of olefins through heterogeneous catalysis. III. Polymer particle modelling with an analysis of intraparticle heat and mass transfer effects

Propylene and ethylene polymerization in liquid and gas media are described by a multigrain particle model. Intraparticle heat and mass transfer effects are investigated for a range of catalyst activities. For slurry polymerization, intraparticle mass transfer effects may be significant at both the macroparticle and microparticle level; however, for normal gas phase polymerization, microparticle mass transfer effects appear more likely to be important. Intraparticle temperature gradients would appear to be negligible under most normal operating conditions.     

ABSORPTION OF GASES IN GROWING DROPLETS

The situation where a stationary droplet in a supersaturated medium is growing by condensation of a vapor and simultaneously absorbing a gas is theoretically analyzed to study the effect of growth on absorption rate. The absorption rate is assumed to be liquid phase diffusion controlled, and the unsteady state liquid phase diffusion equation with moving boundary has been solved by a similarity technique. The results indicate that for fast droplet growth rates, induced by relatively high degrees of supersaturation, the absorption rate is significantly enhanced, leading to higher solute concentration near the surface than that observed for a similar droplet of finite size. For slow growth rates, the results are not significantly different from the quasi-stationary results.     

A low-power inverter-based Σ△ analog-to-digital converter for audio applications

This paper presents a design for a low-power,high-resolution audio Σ△ analog-to-digital converter(ADC)based on a novel gain-boost class-C inverter.The gain-boost class-C inverter behaves as a sub-threshold amplifier,thereby minimizing power dissipation.The proposed ADC chip is fabricated in a SMIC 65-nm CMOS process with a die area of 0.63 mm2.With 1.2 V of supply voltage,the ADC chip achieves a peak signal-tonoise-plus-distortion-ratio(SNDR)of 92 dB and a dynamic range(DR)of 97 dB over the 20 kHz audio band,consuming only 1.13 mW.These results make the ADC particularly suitable for portable electronics applications.     

Cuticular hydrocarbons and defensive compounds ofReticulitermes flavipes (Kollar) andR. santonensis (feytaud): Polymorphism and chemotaxonomy

Colonies ofReticulitermes flavipes andR. santonensis were collected from the southeastern United States (Georgia) and the southwest of France (Charente-maritime). Defensive compounds and cuticular hydrocarbons were identified by gas chromatography-mass spectrometry and quantified by gas chromatography using an internal standard for each caste and all colonies. These analyses show that although the cuticular hydrocarbons ofR. santonensis in Europe andR. flavipes in Georgia are identical, their relative proportions are different. However, the defensive compounds synthesized by their soldiers are different. A strong chemical polymorphism between sympatric colonies ofR. flavipes in the SW United States was detected in terms of both the hydrocarbons of the workers and soldiers and in the defensive secretions of the soldiers. The six defensive secretion phenotypes are based on the presence or absence of terpenes whereas the cuticular hydrocarbon phenotypes are based on significant differences in the proportions of the various components. A multivariate analysis (analysis of principal components) clearly permitted discrimination of four phenotypes (three inR. flavipes and one inR. santonensis) without intermediates. The hydrocarbons responsible for these variations were identified, and it was shown that the variations are neither seasonal nor geographic. The phenotypes of the cuticular hydrocarbons (workers and soldiers) and defensive compounds are linked in each colony, forming in three groups inR. flavipes Georgia, one subdivided into four subgroups according to the defensive secretion phenotypes. The role of these polymorphisms is discussed and ethological tests indicate that the chemical polymorphism do not determine aggressive behavior. The taxonomic significance of these results is considered and two hypothesis are formulated: (1) We only detected a strong genetic polymorphism in one unique species, and we believe thatR. santonensis was introduced into Europe in the last century from oneR. flavipes colony. (2) Chemical variability characterizes the sibling species that can be grouped into the same subspeciesR. flavipes. Unknown mechanisms of reproductive isolation separate them.     

Attraction of adult sweet potato weevils,Cylas formicarius elegantulus (Summers), (Coleoptera: Curculionidae), to sweet potato leaf and root volatiles

A dual-choice olfactometer was developed to study the responses of sweet potato weevils,Cylas formicarius elegantulus (Summers), to volatiles from the sweet potato,Ipomoea batatas (L.) Lam. Both males and females were attracted by volatiles from sweet potato leaves and a methylene chloride leaf extract. Females, but not males, responded to volatiles from storage roots and a methylene chloride root extract. Leaves and storage roots from four sweet potato cultivars (Centennial, Jewel, Resisto, and Regal) were attractive to female weevils; however, the attractant response varied with cultivar. GC profiles from leaf and root extracts, and GC-MS analysis of leaf extract, for Jewel cultivar enabled the volatile peaks to be identified as sesquiterpenes.     

Aromatisation ofn-heptane over ZSM-5 prepared without the aid of a template

ZSM-5 was prepared without the aid of an organic template. Effect of synthesis parameters on its catalytic activity in aromatisation ofn-heptane are discussed. Addition of seed material increased the crystallinity of the ZSM-5 phase. The catalytic activity was comparable with a sample prepared using an organic template. Formation of higher amount of C_9– aromatics was observed over the non-templated zeolite.     

The dynamic behavior of continuous polymerization reactors—II Nonisothermal solution homopolymerization and copolymerization in a CSTR

The possible types of dynamic behavior have been determined for a CSTR in which bulk or solution free radical polymerization is carried out. To illustrate the methodology, the expected behavior of reactors for vinyl acetate or methylmethacrylate homopolymerization and vinyl acetate-methylmethacrylate copolymerization has been explicitly determined. The monomer feed ratios, solvent concentrations, and reactor cooling capacity which allow multiple steady states and limit cycles have been carefully mapped.     

Continuance of mHealth services at the bottom of the pyramid: the roles of service quality and trust

Continued usage of information systems (or, IS continuance) has proven to be a critical success parameter for ICT implementation at the top of the global economic pyramid. However, there are few studies which have explored continued IS usage at the bottom of the economic pyramid (BOP) though it represents the majority of the world’s population. To fill this knowledge gap, this study develops an mHealth continuance model at the BOP framing the impact of two post adoption expectation beliefs (i.e., perceived service quality and perceived trust). This study extends ECM (expectation confirmation model) perspective synthesizing the extant literature on continued IS usage, service quality and consumer trust. The proposed model was empirically tested within the context of mHealth (mobile health) services at the BOP, applying PLS (partial least squares) under a cross sectional study. The findings confirm that both perceived service quality and perceived trust have significant explanatory power under an integrated ECM providing superior prediction of continuance intentions. The study concludes by discussing conceptual contributions, practical implications, limitations and future research directions.     

Considerations for Information Systems “Backsourcing”: A Framework for Knowledge Re-integration

Backsourcing is motivated by opportunities arising from changes in the business situation, redefinition of the character of outsourced service declining in quality or due to the discovery of flaws in the contract. The situation of backsourcing clearly has major implications for an organization in terms of monetary investments, IS infrastructure and changes in employee requirements during and after the process. The paper considers a detailed analysis of two case studies of backsourcing reported from JP Morgan Chase (USA) and Sainsbury (UK). A major contribution of the paper is to identify important strategies to be followed in backsourcing projects to ensure efficient knowledge re-integration.