Acylation of Benzene over Clay and Mesoporous Si-MCM-41 Supported InCl3, GaCl3 and ZnCl2 Catalysts

Liquid phase acylation of benzene by acyl chloride (e.g., benzoyl chloride, butyryl chloride or phenyl acetyl chloride) over InCl₃, GaCl₃ and ZnCl₂ supported on commercial clays (viz. montmorillonite-K10, montmorillonite-KSF and kaolin) or high silica mesoporous MCM-41 at 80°C has been investigated. The Mont.-K10 and Si-MCM-41 supported InCl₃ and GaCl₃ catalysts showed high activity in the acyation of benzene by benzoyl chloride even in the presence of moisture in the reaction mixture. The redox function of the supported InCl₃, GaCl₃ or ZnCl₂ catalysts seems to play a very important role in the acylation process.     

Biomicrofluidics: Recent trends and future challenges

Biomicrofluidics is an active area of research at present, exploring the synergy of microfluidics with cellular and molecular biology, biotechnology, and biomedical engineering. The present article outlines the recent advancements in these areas, including the development of novel lab-on-a-chip based applications. Particular emphasis is given on the microfluidics-based handling of DNA, cells, and proteins, as well as fundamental microfluidic considerations for design of biomedical microdevices. Future directions of research on these topics are also discussed.     

Men's work and family lives in India: The daily organization of time and emotion.

This article examines daily patterns of work and family life for a sample of middle-class men in northern India. One hundred fathers of 8th graders provided information on their hour-to-hour time use and subjective states, by means of the experience sampling method. They reported little time spent on family work but substantial amounts of time with their children and thinking about their families. At their jobs, they reported high levels of attention but more negative emotion. By contrast, the home sphere elicited lower attention, more favorable affect, and more feeling of choice. Unlike for American samples, little relationship was found between experience at work and home, including little influence of men's work emotions on the family in the evening. These findings reflect how strong traditional family roles in India shape men's daily lives. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of a surface-tension gradient on the performance of a micro-grooved heat pipe: an analytical study

We investigate effects of surface-tension gradients on the performance of a micro-grooved heat pipe in this work. The surface-tension gradient force is accounted for in the present model, and expressions for radius of curvature, liquid pressure, liquid velocity, and maximum heat throughput are found analytically using a regular perturbation technique. With a favorable surface-tension gradient, the liquid pressure drop across the heat pipe can be decreased by ∼90%, and the maximum heat throughput can be increased by ∼20%. In contrast, using an unfavorable surface-tension gradient, the liquid pressure drop increases by ∼150%, and the maximum heat throughput decreases by ∼15%. For the same values of the favorable and unfavorable surface-tension gradients, the unfavorable effect is more pronounced than the favorable one. The effects of the surface-tension gradients are found to be increasing with the corner angle of a polygonal heat pipe. Adverse effects of the surface-tension gradient could be due to the variations in the liquid temperature and/or surfactant concentration. Nevertheless, a favorable situation where the surface-tension gradient can facilitate the liquid flow in a heat pipe can also be obtained using a suitable surfactant, surface charge, etc., and then the performance of a micro heat pipe can be improved.     

Instruction set extensions for software defined radio

Software defined radios provide programmable solutions for implementing the physical layer processing of multiple communication standards. Mobile devices implementing these standards require high-performance processors to perform high-bandwidth physical layer processing in real time. In this paper, we present instruction set extensions for several important communication algorithms including cyclic redundancy checking, convolutional encoding, Viterbi decoding, turbo decoding, and Reed–Solomon encoding and decoding. We also present hardware designs for implementing these extensions, along with estimates of their area, critical path delay, and power consumption. The performance benefits of these extensions are evaluated using a supercomputer-class vectorizing compiler and the Sandblaster low-power multithreaded processor for software defined radio. The proposed instruction set extensions provide significant performance improvements at relatively low cost, while maintaining a high degree of programmability.     

Motion estimation based color transfer and its application to color video compression

In this paper a novel scheme for color video compression using color transfer technique is proposed. Towards this, a new color transfer mechanism for video using motion estimation is presented. Encoder and decoder architectures for the proposed compression scheme are also presented. In this scheme, compression is achieved by firstly discarding chrominance information for all but selected reference frames and then using motion prediction and discrete cosine transform (DCT) based quantization. At decompression stage, the luminance-only frames are colored using chrominance information from the reference frames applying the proposed color transfer technique. To integrate color transfer mechanism with hybrid compression scheme a new color transfer protocol is defined. Both compression scheme and color transfer work in YCbCr color space.

A semi-analytical model for species transport in combined electroosmotic and pressure driven microflows with surface adsorption�Cdesorption reactions

We derive semi-analytical solutions for solutal concentration distribution in microfluidic channels under the combined action of pressure-driven and electroosmotic transport, considering the effects of adsorption–desorption reactions at the substrate–fluid interface. Within the pertinence of common bio-microfluidic applications, we obtain the spatio-temporal evolution of analyte concentration by solving the corresponding eigen value problems on species transport with non self-adjoint operators, yielding non-orthogonal eigen functions. We analyze the implications of the relative strengths of the pressure-driven and electroosmotic flow components towards dictating the strongly interconnected reaction–advection–diffusion transport. We also discuss various interesting limiting cases, including the situations in which the solutal concentration band effectively propagates in the microchannel as a shock front. For such cases, we obtain the propagation velocity of the band as an explicit function of the relative strengths of the respective flow actuation mechanisms and the other significant parameters pertinent to the surface reactions.     

Measurement and performance issues of transport protocols over 10 Gbps high-speed optical networks

With the integration of IP and optical technology, a high-speed optical network (of the order of 10Gbps) has emerged to support international research cooperation such as massive scientific data transfer and next generation Internet related research. Therefore, it is critical to explore the issues of measurement and evaluation on the performance of transport protocols over 10 Gbps high-speed optical networks. To the best of our knowledge, this is the first work that presents a measurement study on a variety of networking environments. The objectives of this paper are as follows: (i) determine the suitability of TCP parameters such as Jumbo Frame size, buffer sizes of a TCP sender and a receiver; (ii) evaluate TCP performance measurement tools and emulation tools over 10 Gbps high-speed optical networks; and (iii) compare performance of TCP variants with different metrics, such as throughput and fairness, by varying delays and randomized losses controlled with software emulators. The result shows that selection of emulation and performance measurement tools matters for the accurate measurement of TCP performance. The performance of TCP variants is highly impacted by the Linux TCP/IP stack tuning. Finally we present that overall and detailed performance, such as throughput and fairness, of each TCP variant is dependent on different network environments, such as packet loss rate and propagation delay.     

Production of Flexible Transparent Conducting Films of Self‐Fused Nanowires via One‐Step Supersonic Spraying

Scalable and economical manufacturing of flexible transparent conducting films (TCF) is a key barrier to widespread adoption of low‐cost flexible electronics. Here, a simple, robust, and scalable method of flexible TCF formation using supersonic kinetic spraying is demonstrated. Silver nanowire (AgNW) suspensions are sprayed at supersonic speed to produce self‐sintered films of AgNWs on flexible substrates. These films display remarkably low sheet resistance, <10 Ω sq^?1, combined with high transmittance, >90%. These electrically conducting, transparent, and flexible coatings can be deposited over a 100 cm² area in ≈30 s. Theoretical analysis reveals the underlying physical mechanism behind self‐sintering, showing that self‐sintering is enabled by the high velocity of impact in supersonic spraying.