Combustion synthesis and characterization of highly crystalline single phase nickel ferrite nanoparticles

A combustion route of synthesizing highly crystalline single phase nickel ferrite (NiFe₂O₄) spinel nanoparticles using various amounts of dl-alanine as fuel has been reported in this paper. The role of the amount of fuel is found to be significant in the size control and phase purity of nano crystalline samples. The structural, thermal, morphological and magnetic studies have been carried out. XRD patterns reveal the formation of highly crystalline nano NiFe₂O₄ with high degree of phase purity when fuel concentration is maintained at 1 M and 2 M. FTIR spectra also prove the formation of pure nano NiFe₂O₄. The temperature and fuel effects are found to have strong influence on size, structural, and magnetic properties of materials. The magnetic measurements show that the nano NiFe₂O₄ samples exhibit soft ferromagnetism with the highest saturation magnetization Ms at room temperature as 42.53 emu/g.     

Beyond exchange models: Understanding the structure of B2B information systems

This paper provides a framework to characterize the structure of information systems that enable transactions between businesses. We propose that the structure of various inter-organizational information systems, including traditional EDI systems and more recent web based exchanges, can be characterized in terms of four underlying dimensions: control, relational support, integration, and technology dimensions. In our paper we explain and operationalize these dimensions as constructs, and examine how each of them might be affected by inter-organizational relationship or product specific antecedents. We argue that these dimensions are fundamental to more realistically representing an organizations involvement with and use of inter-organizational information systems. Further, we argue that specific product types and preexisting relationships between organizations will be strongly associated with the variables representing the dimensions of Inter-organizational information systems.     

Kinetics of reaction between meta-substituted long chain alkyl phenols and formaldehyde

The reaction between formaldehyde and long chain alkyl phenols as cardanol and 3-pentadecylphenol is found to be of second order, when it is studied in dioxanater (1:1) system in presence of catalyst hydroxide sodium as at 28, 50 and 70°C. Individual methylols were separated and identified by thin layer chromatography. The long alkyl chain in the meta-position of the phenolic nuclei sterically hinders The reactivity of 2-position at 28°C, but at higher temperatures i. e. 50 and 70°C this position gets activated resulting in the formation of various methylols.     

Large-scale preparation of perchlorates directly from sodium chloride

Based on the optimum conditions arrived at in the laboratory experiments, large-scale trials have been carried out for the preparation of sodium perchlorate by the direct oxidation of sodium chloride in a single step using a graphite substrate lead dioxide anode.Two cells of 75 A capacity and one 400 A cell were run continuously at an anode current density of 20 A/dm² and a temperature of 45°–50°C. The cell performance with these anodes is given.Potassium and ammonium perchlorates formed by double decomposing the sodium perchlorate obtained by this method with the respective chlorides are pure and conform to the stringent specifications.Presented at the Eleventh Seminar on Electrochemistry held at Central Electrochemical Research Institute, Karaikudi-3 in November 1970.     

A theory of bipolar synchronization schemes

The aim is to better understand the relationships between choice and concurrency that lead to the good behaviour of distributed systems. In order to do so, we formulate a model based on Petri nets and develop its theory. The model is called bipolar synchronization schemes (bp schemes) and the theory we construct is mainly devoted to synthesising, in a systematic fashion, all well behaved bp schemes. We also provide a computational interpretation of well behaved bp schemes. Through this interpretation the insights gained by developing the theory of bp schemes can be transferred to concurrent programs.     

Energy efficient surveillance system using WVSN with reweighted sampling in modified fast Haar wavelet transform domain

Wireless visual sensor network (WVSN) consists of a large number of nodes that are capable of acquiring, compressing and transmitting images. Surveillance becomes a vital application area of WVSN as they can be deployed in various environments to monitor and collect information. The lifetime of the nodes in the network depends on the energy consumption. Hence in this paper, block compressed sensing (BCS) based image transmission technique that utilizes Energy based Reweighted sampling (ERWS) in Modified Fast Haar Wavelet Transform (MFHWT) domain is proposed to reduce energy consumption considerably. Sparse binary random matrix is used to acquire CS measurements in MFHWT domain. In addition, the proposed technique also maintains the image quality. The developed algorithm is applied and tested for a car parking lot monitoring system. It is evident from the simulation results that the proposed method achieves better PSNR values even for fewer measurements. Experimental analysis is performed using Atmega 128 processor of Mica mote in WinAVR by Atmel. The proposed method has approximately 85.5% lesser energy consumption than other Compressed Sensing (CS) methods. Lossless Entropy Coding is applied to the ERWS measurements and considerable reduction in number of transmitted bits is also achieved. The algorithm has also been tested in WINGZ mote in real time.     

Visual Exploration of High‐Dimensional Data through Subspace Analysis and Dynamic Projections

We introduce a novel interactive framework for visualizing and exploring high‐dimensional datasets based on subspace analysis and dynamic projections. We assume the high‐dimensional dataset can be represented by a mixture of low‐dimensional linear subspaces with mixed dimensions, and provide a method to reliably estimate the intrinsic dimension and linear basis of each subspace extracted from the subspace clustering. Subsequently, we use these bases to define unique 2D linear projections as viewpoints from which to visualize the data. To understand the relationships among the different projections and to discover hidden patterns, we connect these projections through dynamic projections that create smooth animated transitions between pairs of projections. We introduce the view transition graph, which provides flexible navigation among these projections to facilitate an intuitive exploration. Finally, we provide detailed comparisons with related systems, and use real‐world examples to demonstrate the novelty and usability of our proposed framework.     

A comparative study on particle�Cfluid interactions in micro and nanofluids of aluminium oxide

Stable dispersions of micro and nanosized Al₂O₃ particles in ethylene glycol are prepared with the aid of sonication. The temperature dependant acoustic properties such as ultrasonic velocity, adiabatic compressibility, attenuation and acoustic impedance are studied and reported in this paper. In microfluids the particle–fluid interaction is observed to decrease with increase of concentration of particles whereas in nanofluids it is observed to increase up to the critical concentration (0.6 Wt%) and above which the particle–particle interaction dominates due to agglomeration of particles. A range of concentration with significant particle–fluid interaction is identified for effective nanofluid applications.     

实时任务准入控制器的自动合成

在许多实时系统中,同一个计算平台上往往既有硬实时关键计算任务又有软实时非关键计算任务.硬实时任务必须在规定时间内完成,否则将导致系统错乱或崩溃等严重后果.而软实时任务若没有在规定时间内完成,虽会影响系统性能,但不会造成重大后果.为确保每个硬实时任务均在其规定时间内完成,在某些情况下需要拒绝一些软实时任务进入任务队列.文章提出了一种基于控制器自动合成策略的解决方案,通过所设计的准入控制器,对系统产生的每一个新任务自动决定是否准其进入任务队列.准入控制器必须使得所有被准入的任务均在规定时间内完成,并且决策序列满足以线性时态逻辑描述的服务质量要求.文章的主要贡献是提出了判定是否存在准入控制器的算法,该算法能在判定结果为真时构造出一个以有限状态时间自动机表达的准入控制器.     

Connecting Active‐Site Loop Conformations and Catalysis in Triosephosphate Isomerase: Insights from a Rare Variation at Residue 96 in the Plasmodial Enzyme

Despite extensive research into triosephosphate isomerases (TIMs), there exists a gap in understanding of the remarkable conjunction between catalytic loop‐6 (residues 166–176) movement and the conformational flip of Glu165 (catalytic base) upon substrate binding that primes the active site for efficient catalysis. The overwhelming occurrence of serine at position 96 (98 % of the 6277 unique TIM sequences), spatially proximal to E165 and the loop‐6 residues, raises questions about its role in catalysis. Notably, Plasmodium falciparum TIM has an extremely rare residue—phenylalanine—at this position whereas, curiously, the mutant F96S was catalytically defective. We have obtained insights into the influence of residue 96 on the loop‐6 conformational flip and E165 positioning by combining kinetic and structural studies on the PfTIM F96 mutants F96Y, F96A, F96S/S73A, and F96S/L167V with sequence conservation analysis and comparative analysis of the available apo and holo structures of the enzyme from diverse organisms.