Carbonium Ion and Hydridocobalt Intermediates in the Acidic Phase Transfer Catalyzed Reactions of Olefins and Dienes with Cobalt Carbonyl

The intermediates mentioned in the title are probably involved in the hydrogenation of olefins and dienes; bidentate phosphine and arsine cobalt complexes are useful reagents for these reactions.     

Preparation,characterization and thermal properties of PMMA/n-heptadecane microcapsules as novel solid–liquid microPCM for thermal energy storage

This study is focused on the preparation, characterization and thermal properties of microencapsulated n-heptadecane with polymethylmethacrylate shell. The PMMA/heptadecane microcapsules were synthesized as novel solid–liquid microencapsulated phase change material (microPCMs) by emulsion polymerization method. The chemical and thermal characterization of the microPCMs were investigated using scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). The diameters of microPCMs were found in the narrow range (0.14–0.40 μm) under the stirring speed of 2000 rpm. The spherical surfaces of microPCMs were smooth and compact. The DSC results show that microPCMs have good energy storage capacity. Thermal cycling test showed that the microPCMs have good thermal reliability with respect to the changes in their thermal properties after repeated 5000 thermal cycling. TGA analyses also indicated that the microPCMs degraded in three steps and have good thermal stability. Based on all results, it can be considered that the PMMA/heptadecane microcapsules as novel solid–liquid microPCMs have good energy storage potential.     

Thermal energy storage by poly(styrene-co-p-stearoylstyrene) copolymers produced by the modification of polystyrene

A series of poly(styrene-co-p-stearoyl styrene) copolymers as novel polymeric solid–solid phase-change materials (SSPCMs) were synthesized by the modification of polystyrene with stearoyl chloride. The chemical structure and crystalline morphology of the synthesized copolymers were determined with Fourier transform infrared spectroscopy and polarized optical microscopy, respectively. The thermal energy storage properties and thermal stability of the SSPCMs were investigated with differential scanning calorimetry and thermogravimetric analysis, respectively. In addition, the thermal conductivity of the SSPCMs was measured with a thermal property analyzer. Moreover, thermal cycling tests showed that the copolymers had good thermal reliability and chemical stability after being subjected to 5000 heating/cooling cycles. The synthesized poly(styrene-co-stearoyl styrene) copolymers as novel SSPCMs have considerable potential for thermal energy storage and temperature-control applications. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Characteristics of CFRP retrofitted hollow brick infill walls of reinforced concrete frames

The mechanical characteristics of infill walls retrofitted with carbon fiber reinforced polymer (CFRP) sheets are really important for the realistic prediction of seismic performance of the vulnerable reinforced concrete (RC) frames retrofitted through CFRP strengthened infill walls. In this study, 36 hollow brick wall specimens were tested either under uniaxial compression or diagonal tension before and after retrofitting externally with CFRP sheets. The test parameters are the dimensions of the walls, the orientation of holes of bricks, the type of mortar, the amount of CFRP sheets and the details of strengthening application. At the end of the tests, a significant contribution of CFRP sheets on the mechanical characteristics of hollow brick walls was observed in terms of several important structural design parameters such as Young and shears moduli, axial and shears strengths as well as the deformation capacity. Finally, the strength and deformability characteristics of the walls and frames retrofitted with CFRP sheets were predicted analytically. The predictions were in good agreement with the experimental data.     

A universal low-noise analog receiver baseband in 65-nm CMOS

In this paper, a novel universal receiver baseband approach is introduced. The chain includes a post-mixer noise shaping blocker pre-filter, a programmable-gain post mixer amplifier (PMA) with blocker suppression, a differential ramp-based novel linear-in-dB variable gain amplifier and a Sallen–Key output buffer. The 1.2-V chain is implemented in a 65-nm CMOS process, occupying a die area of 0.45 mm². The total power consumption of the baseband chain is 11.5 mW. The device can be tuned across a bandwidth of 700-KHz to 5.2-MHz with 20 kHz resolution and is tested for two distinct mobile-TV applications; integrated services digital broadcasting-terrestrial ISDB-T (3-segment f _c = 700 kHz) and digital video broadcasting-terrestrial/handheld (DVB-T/H f _c = 3.8 MHz). The measured IIP3 of the whole chain for the adjacent blocker channel is 24.2 and 24 dBm for the ISDB-T and DVB-T/H modes, respectively. The measured input-referred noise density is 10.5 nV/sqrtHz in DVB-T/H mode and 14.5 nV/sqrtHz in ISDB-T mode.     

Objective and subjective socioeconomic status and susceptibility to the common cold.

Objective: We ask whether subjective socioeconomic status (SES) predicts who develops a common cold when exposed to a cold virus. Design: 193 healthy men and women ages 21-55 years were assessed for subjective (perceived rank) and objective SES, cognitive, affective and social dispositions, and health practices. Subsequently, they were exposed by nasal drops to a rhinovirus or influenza virus and monitored in quarantine for objective signs of illness and self-reported symptoms. Main Outcome Measures: Infection, signs and symptoms of the common cold, and clinical illness (infection and significant objective signs of illness). Results: Increased subjective SES was associated with decreased risk for developing a cold for both viruses. This association was independent of objective SES and of cognitive, affective and social disposition that might provide alternative spurious (third factor) explanations for the association. Poorer sleep among those with lesser subjective SES may partly mediate the association between subjective SES and colds. Conclusions: Increased Subjective SES is associated with less susceptibility to upper respiratory infection, and this association is independent of objective SES, suggesting the importance of perceived relative rank to health. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multirelational k-Anonymity

k-Anonymity protects privacy by ensuring that data cannot be linked to a single individual. In a k-anonymous data set, any identifying information occurs in at least k tuples. Much research has been done to modify a single-table data set to satisfy anonymity constraints. This paper extends the definitions of k-anonymity to multiple relations and shows that previously proposed methodologies either fail to protect privacy or overly reduce the utility of the data in a multiple relation setting. We also propose two new clustering algorithms to achieve multirelational anonymity. Experiments show the effectiveness of the approach in terms of utility and efficiency.     

Seismic base isolation using low-cost Scrap Tire Pads (STP)

This paper focuses on the experimental studies conducted on the development of no-cost seismic base isolation pads using scrap automobile tire pads (STP). The mechanical and dynamic properties of STP specimens made from different tire brands, with different number of layers, and orientations are evaluated experimentally. The tests are conducted using (a) axial compression tests, (b) lumped mass small displacement free vibration, and (c) large displacement (inclined plate and reverse-cyclic) static shear tests. The results of these STP tests are compared among themselves and against a commercially available laminated rubber bearing specimen. A general relationship has been proposed which formulates the stiffness differences between the two principal directions of rectangular pads. The paper includes three hypothetical design applications for the use of STPs. STPs are prepared by placing 18 cm × 20 cm cut tread sections layers of car tires on top each other. Larger size STPs can also be formed by placing longer strips of tread sections (integer multiples of tread width) side by side in alternating direction layers or using a woven structure. Test results have shown that the friction between tire layers is sufficient to keep layers intact. Although STP application cannot eliminate foundation-basement structural requirements, it presents advantages such as low-technology no-cost pad, weight reduction, ease of handling, simple shear stiffness adjustment by changing the number of layers, and environmental benefits by recycling scrap tires.     

Determination of important biochemical properties of honey to discriminate pure and adulterated honey with sucrose (Saccharum officinarum L.) syrup

The aims of the present study were to determine biochemical properties of honey samples and to discriminate pure and adulterated honey produced by the standard bee feeding method (control honey), the shaking method (pure blossom honey), and overfeeding (100 kg/colony syrup) with sucrose syrup (adulterated honey). The biochemical properties evaluated were moisture, ash, acidity, hydroxymethylfurfural (HMF), specific sugars (i.e. fructose, glucose, fructose–glucose, sucrose, and maltose), diastase activity, δ¹³C value (honey), δ¹³C value (protein), electrical conductivity, potassium, vitamin C, and proline. Fifteen honey samples were analyzed by discriminant analysis stepwise method. Proline, electrical conductivity and sucrose were found as discriminative characters of samples. Based on these three properties 100% of original group cases (samples) correctly classified in their real group. We found that the honey produced by feeding with 100 kg sucrose syrup per colony contained the sucrose as low as pure blossom honey. Therefore, the sugar (sucrose, fructose and glucose) content of honey cannot be used to distinguish between adulterated (sucrose syrup) and pure blossom honey.