Updated data dissemination methods for updating old replicas in ad hoc networks

In this paper, we propose two updated data dissemination methods to not only reduce the number of accesses to old replicas, but also to improve the data accessibility in ad hoc networks where data items are updated regularly. In the first method, when a mobile host updates a data item, it disseminates the updated data item after the flooding of with invalidation reports. In the second method, two newly connected mobile hosts disseminate updated data items with each other after the flooding with invalidation reports.     

Determination of Ring-OSF Position in Czochralski Silicon Single Crystals by Numerical Analysis of Distribution of Grown-in Defects

A numerical analysis technique that incorporates Voronkov's model were examined and used to estimate the distribution of defects during crystal growth. By comparisons of the distribution of the density of LSTD and the position of R-OSF in non-nitrogen-doped (non-N-doped) and nitrogen-doped (N-doped) silicon crystals, it is found that the results of the numerical analyses agree with practically evaluated data. The observations suggest that the R-OSF nucleus is a VO2 complex that is formed by bonds between oxygen atoms and residual vacancies consumed during the formation of void defects. This suggests that Voronkov's model can be used to accurately predict the generation and growth of defects in silicon crystals. This numerical analysis technique was also found to be an effective method of estimating the distribution of defects in silicon crystals during crystal growth.     

Properties of graphite prepared from boron-doped pitch as an anode for a rechargeable Li ion battery

Boron-doped graphites were derived from a naphthalene-based pitch mixed with para-xylene glycol (PXG) or dimethyl para-xylene glycol (DMPXG) as a cross-linking agent and three types of boron-containing compounds as a graphitization catalyst, and their anode performances were investigated. The structural analysis of the obtained graphites revealed that PXG functioned mainly as a two-dimensional cross-linking agent during the heat treatment process and DMPXG functioned partially as a three-dimensional. The average interlayer spacing decreased and lattice constant, a₀, and graphitizability increased with increasing the amount of boron atoms added. The result indicated that the carbon atoms were replaced by boron atoms. The anode performance was improved by the enhancement of graphitizability. The structural parameters and anode performance of boron-doped graphites did not depend on the kind of boron-containing compounds but the amount of boron atoms added in pitch and the kind of cross-linking agent.     

Efficient synthesis of nonnatural mutants in Escherichia coli S30 in vitro protein synthesizing system

Factors that affect the efficiency of in vitro synthesis of mutant proteins that contain nonnatural amino acids were investigated. The process of the nonnatural mutagenesis consists of chemical aminoacylation of a tRNA that contains a 4-base anticodon, followed by in vitro synthesis in the presence of an mRNA that contains the corresponding 4-base codon. Detailed studies on the time courses of the synthesis revealed two major factors that suppress the yield of nonnatural mutants compared with the wild-type protein. First, a cyclic tRNA that exists as a by-product of the chemical aminoacylation inhibits the protein synthesis. Second, the very short lifetime of a tRNA aminoacylated with a nonnatural amino acid limits the protein yield. As a simple and practical way of surmounting these factors, aminoacyl tRNA was added into the in vitro system at 5 min after the start of the synthesis. The addition increased the protein yield up to the level of conventional proteins in the in vitro system.     

红外相机CASCAM的电动系统设计

介绍了红外相机CASCAM的电动系统设计。系统采用AT90S8515单片机和TA8435集成芯片组成驱动电路的核心,通过电机选择电路和位置反馈电路实现对步进电机的选择驱动和定位、复位。系统采用MAXIM232芯片实现单片机和上位机之间的串行通讯。系统软件以汇编语言编制,并给出了系统程序框图。经实验验证,该系统运行可靠,达到了设计要求。     

An aqueous suspension system for phospholipase D-mediated synthesis of PS without toxic organic solvent

Enzymatic synthesis of PS by phospholipase D (PLD)-mediated transphosphatidylation in an aqueous media was investigated. The purpose of this study was to establish a novel synthetic method where no toxic organic solvents were used. An attempt to react soybean lecithin (simply dispersed in an aqueous buffer) with an aqueous solution of l-serine and PLD was unsuccessful, giving only 20% of PS. By contrast, a suspension of lecithin adsorbed on fine powders such as silica was effectively converted into PS in an aqueous solution of l-serine and PLD. After screening various powders for use as the lecithin adsorbent, calcium sulfate was found to be the best with respect to lecithin conversion. In addition, calcium sulfate did not require prior adsorption of lecithin (i.e., the reaction proceeded effectively simply by adding the powder to an aqueous mixture of lecithin, l-serine, and PLD). With this “aqueous suspension system” of calcium sulfate, up to 180 mg/mL lecithin was completely converted, resulting in more than 80% PS in 24 h. The synthesized PS could easily be recovered from the powder by extracting with a mixture of n-hexane, ethanol, and diluted HCl.     

Adaptive searching and replication of images in mobile hierarchical peer-to-peer networks

Due to the limitation of resources in mobile handheld devices and bandwidth constraints in wireless networks, it is important to efficiently manage image content and traffic to improve network throughput and response time. The efficient distribution of images in wireless networks is based on many parameters like the quality of service requirement, available bandwidth, restricted memory and diverse user profiles. We consider digital images as data objects accessed in a hierarchical mobile ad-hoc peer-to-peer network, referred as M-P2P. Our objective is to optimize the number of replicas of images in such a network architecture based on the resource limitations of the requesting peers equipped with miniature mobile devices as well as of wireless constraints in mobile ad-hoc networks (MANET). While replicating images, fragments of different resolution and their residues are used to optimize the traffic in the network and to decrease the search turnaround time. We call this replication algorithm as Ada-Rep. Performance evaluation is done by simulating Ada-Rep, base replication and uniform replication methods to evaluate parameters such as response time, failure rate, memory usage, traffic etc. Our results prove the efficiency and better performance of Ada-Rep.     

Power generation of the touching Cu/Bi-Te/Cu composites under the periodically alternating temperature gradients

The thermo-emf ΔV of the touching p- and n-type Cu/Bi-Te/Cu composites with different thicknesses of t _Bi-Te and t _Cu was measured as a function of time by alternating the temperature difference ΔT at periods of T = 20, 60, 120, 240 and ∞ sec, where t _Bi-Te was varied from 0.1 to 2.0 mm and t _Cu from 0 to 4.0 mm. As a result, ΔV changes significantly with t _Bi-Te, t _Cu and T. The effective thermo-emf ΔV _eff increases significantly with an increase of 1/T and exhibited a local maximum at 1/T = 1/240 s⁻¹. The resultant | α | and the effective temperature difference ΔT _eff were increased significantly by optimizing t _Bi-Te and t _Cu at 1/T = 1/240 s⁻¹. The power generation ΔW _eff (= ΔV _eff²/4R _calc) estimated using the measured ΔV _eff and calculated R _calc also exhibited a local maximum at 1/240 s⁻¹ for an optimum combination of t _Bi-Te = 0.1 mm and t _Cu = 2.0 mm, so that the maxima ΔW _eff at 1/T = 1/240 s⁻¹ for the p- and n-type composites were 2.28 and 2.92 times higher than those obtained at 1/T = 0 s⁻¹. This significant increase in ΔW _eff is owing to both the increase in ΔT _eff and the increase in ZT due to the increase in |α|. The power generation was thus found to be enhanced significantly by imposing the alternating temperature gradients on touching Cu/Bi-Te/Cu composites.     

A novel spacer‐free panel structure and glass for FEDs

Abstract— A new design for an FED envelope, composed of box‐shaped front glass, sheet‐like rear glass, and metal members, has been devised. This design structure is effective in reducing tensile stress induced by vacuum at the sealing points. Also, a new glass composition, a new physical tempering method, and a lead‐free hermetic sealing material have been developed. As a result, a novel lightweight spacer‐free panel structure for FEDs has been developed by integrating these new technologies. It will assist in maximizing the essential advantages of FED such as high image quality, high reliability, and low cost.