Liquid‐Crystalline Electrolytes for Lithium‐Ion Batteries: Ordered Assemblies of a Mesogen‐Containing Carbonate and a Lithium Salt

Thermotropic liquid‐crystalline (LC) electrolytes for lithium‐ion batteries are developed for the first time. A rod‐like LC molecule having a cyclic carbonate moiety is used to form self‐assembled two‐dimensional ion‐conductive pathways with lithium salts. Electrochemical and thermal stability, and efficient ionic conduction is achieved for the liquid crystal. The mixture of the carbonate derivative and lithium bis(trifluoromethylsulfonyl)imide is successfully applied as an electrolyte in lithium‐ion batteries. Reversible charge–discharge for both positive and negative electrodes is observed for the lithium‐ion batteries composed of the LC electrolyte.     

Protein refolding in nanostructured reversed micelles including a molecular chaperone

Reversed micelles including the molecular chaperone GroEL were applied to the protein refolding of denatured RNase A. The molecular chaperone was successfully functionalized in the water pools of the reversed micelles sharing a structural size of 15-25 nm. The refolding yield of RNase A in the reversed-micelle/GroEL system was much greater than that of spontaneous renaturation. The refolding yield mediated by GroEL in the reversed micelles was strongly dependent on the presence of ATP or Mg2+, suggesting that the GroEL hosted in the reversed micelles was biologically active in the micelles. Under the optimum conditions, this novel refolding technique could completely renature the denatured RNase A in 1 h.     

AC response analysis of C-V curves and quantitative analysis of conductance curves in Al2O3/InP interfaces

The ac signal response of majority carriers has been systematically investigated for Al₂O₃/InP metal-insulator-semiconductor (MIS) interfaces using C-V and the conductance methods. It was revealed by the conductance curve fitting that both slow trap and interface trap responses contribute to a conductance curve at the Al₂O₃/InP interfaces in the depletion bias condition, and that the contribution of slow trap response and large surface potential fluctuation make it difficult to obtain a clear conductance peak. It was found that the conductance curves in high frequency region can be represented by the surface potential fluctuation model. This means that the analysis through the conductance curve fitting is effective in characterizing III-V MIS interfaces.     

A study on condition assessment method of gas‐insulated switchgear. part II. influence of moisture in the SF6, detection of a partial discharge on a spacer,repetition discharge and overheating by incomplete contact

Rationalization of the maintenance of gas‐insulated equipment under operation and lifetime extension based on the results of appropriate diagnosis are necessary to reduce the cost of gas‐insulated equipment. Therefore, condition‐based maintenance (CBM) is required and accurate methods for observing the inside of equipment are important. In this report, we describe a diagnosis method that can be used for actual gas‐insulated equipment, such as to assess the deterioration of the spacers made of epoxy resin and to detect loose connections in the central conductor. The principal results are summarized as follows: (1) The quantity of decomposition gases depends on the moisture and magnitude of the partial discharge. However, decomposition gases were detected even if SF₆ had low moisture content (less than 100 ppm) similar to that used in actual equipment. This means that our method can be applied to actual equipment. (2) It became clear that CF₄ is a typical gas generated by partial discharge on the spacer surface. Therefore, it is possible to diagnose spacer deterioration by monitoring CF₄. (3) Decomposition gases (SF₄, SO₂, SO₄, SO₂F₂) were generated by impulse breakdown, which was assumed to be due to repetition discharge caused by insulation failure and loose connections. (4) SF₆ gas was assumed to be exposed to a loose connection and was heated from room temperature to 800 °C, and the generated decomposition gases were analyzed by FTIR in real time. As a result, the decomposition gases were generated at temperatures above approximately 500 °C in a heating time of 1.5 minutes. Therefore, a loose connection can be detected by analyzing the decomposition gas. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 176(2): 22–30, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21108     

Thermodynamic Measurement of Di-calcium Phosphate

The thermodynamic properties of the CaO-P₂O₅ system are important to develop an effective refining process in the iron and steel industry. In this study, the thermodynamic properties of (CaO)₂P₂O₅ were investigated because the properties are necessary to develop a new dephosphorization process. The vapor of gaseous phosphorus and phosphorus oxide in equilibrium with a mixture of (CaO)₂P₂O₅ and (CaO)₃P₂O₅ at 1373 K to 1498 K (1100 °C to 1225 °C) were detected directly as an ion current by double Knudsen cell mass spectrometry. Comparing the ion currents with those from a mixture of Al₂O₃P₂O₅ and Al₂O₃, which is used as a reference mixture in this study, the Gibbs energy change of the following reaction was calculated:

Decomposition rate control of PLLA plate by heat treatment

It is difficult to control the decomposition rate and the mechanical property of scaffolds after forming the poly(L ‐lactide) (PLLA) scaffolds. The purpose of this study is to control the decomposition rate and mechanical properties of the PLLA plate after forming. We carried out accelerated decomposition experiments using the enzyme on the (PLLA) with various crystallinity, which were prepared by changing the heat treatment condition, and elucidated the relationship between the crystallinity and the decomposition rate. A high positive correlation was observed between the heat treatment temperature and the crystallinity. A high negative correlation was observed between the crystallinity and the decomposition rate. Using the obtained empirical formula, it became possible to calculate the required period to decompose a certain amount of the PLLA if the heat treatment temperature was known. Changing the crystallinity of the PLLA plate could arbitrarily control the decomposition rate of the PLLA plate after forming. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Generation of interstitial boron by minority-carrier injection

The performance of boron-doped CZ Si solar cell is degraded by the light irradiation and/or the minority carrier (electron) injection. To understand these phenomena, ab initio molecular orbital calculations are carried out using a cluster model. The theoretical results indicate that the activation energy for kicking out a substitutional B by the interstitial Si is decreased due to the injected electron. Therefore, the interstitial B is easily produced by the minority carrier injection and then diffuses in the Si crystal, resulting in the generation of the interstitial B and interstitial O defect complex.     

Remedy for round-off error accumulation observed in a neutron diffusion calculation using the multiple reciprocity boundary element method

A round-off error accumulation is observed in a multiple reciprocity computation for a fission neutron source iteration problem when a certain convergence condition is not satisfied. The present paper presents a reformulation of the multiple reciprocity method to remove the numerical problem. The neutron diffusion equation (NDE) is arranged using Wielandt's spectral shift technique in such a way that the convergence condition is always satisfied through source iterations. The boundary integral equation in this case requires the fundamental solution to the standard Helmholtz equation, while the fundamental solution corresponding to the correspoding to the original NDE was one to the modified Helmholtz equation. Except for this, the new multiple reciprocity formulation is identical to the original one for the fission source iteration problems. Some test calculation results indicate that a rapid and stable convergence can be realized using the new method and no round-off error accumulation is observed any more.     

SIZE DISTRIBUTION OF CLUSTERS INHERENT IN RANDOM DISPERSIONS OF EQUAL SPHERES WITH A COAGULATION RADIUS

The spatial structure of a computer-simulated random dispersion of equal spheres is investigated. The sphere of influence, i.e. the coagulation radius, is assumed for each particle without any particle movement. If the distance between sphere centers lies within the coagulation radius, the spheres are regarded as being connected to each other to form a cluster. Various sizes of clusters exist inherently in the random dispersion. The effects of the coagulation radius and the bulk-mean particle volume fraction on the size distribution of clusters are discussed theoretically and experimentally.