Effects of polyglycerol esters of fatty acids and ethylene‐vinyl acetate co‐polymer on crystallization behavior of biodiesel

Biodiesel fuels (BDF) have many problems in the cold due to their crystallization properties. In particular, precipitation of large crystals of high‐melting fractions in BDF at low temperatures remarkably changes cold flow property of BDF and, thereby, it increases the values of cold filter plugging point. In this study, we evaluated polyglycerol esters of fatty acids (PGE) and ethylene‐vinyl acetate co‐polymer (EVA) as chemical additives to improve the cold flow property of palm oil‐based FAME (PFME). The results of solid fat content measurement indicate that the simultaneous addition of PGE and EVA showed synergistic effects on suppression of crystallization of PFME, however such effect was not observed when EVA was used alone. DSC thermograms indicated that the PGE additives not only decreased the crystallization temperature but also kinetically suppressed the crystal growth. Polarized light microscopy showed that the simultaneous addition of PGE and EVA led to the formation of considerably small and fine‐dispersed crystals of PFME. These results indicate that combined effects of PGE and EVA caused the formation of fine‐dispersed PFME crystals, which could improve the viscous properties of palm oil‐based BDF at relatively cold temperatures.     

Difference in the detection limits of flaws in the depths of multi-layered and continuous aluminum plates using low-frequency eddy current testing

We examined the difference in the detection limits of flaws in the depths of multi-layered and continuous aluminum plates using low-frequency eddy current testing. The detection limits were measured by using a magneto-resistive sensor. Comparing the frequency of an applied magnetic field, the detection limit at 50 Hz is deeper than that at 1 kHz. Comparing the sample structure, the detection limit in the multi-layered samples is deeper than that in the continuous samples. These results are likely due to the differences in the skin depth and conductivity of the sample.     

Purification and properties of beta-N-acetylglucosaminidase from Vibrio alginolyticus H-8

Beta-N-acetylglucosaminidase [EC 3.2.1.30] from Vibrio alginolyticus H-8 was purified by column chromatography on DEAE-Sepharose FF, phenyl-Sepharose HP, Superdex 200HR, and Mono Q. The molecular weight of the enzyme was estimated by SDS-gel electrophoresis (SDS-PAGE) to be 75 kDa. The pI was 4.6. The activity was inhibited by Ag+, Hg2+, iodoacetate, p-chloromercuribenzoate, and N-ethylmaleimide.     

pH measurement in the vicinity of a cathode evolving hydrogen gas using an antimony microelectrode

An antimony microelectrode was prepared by quenching a molten Sb–Sb2O3 mixture (2% Sb2O3). The local pH in the vicinity of a cathode evolving hydrogen gas was directly measured using the microelectrode. The local pH during electrolysis of KCl-glycine aqueous solutions was increased by proton consumption; however, the increment decreased with increasing concentrations of glycine, a buffering agent. The diffusion-limiting current density of hydrogen evolution involving proton reduction was controlled by the concentrations of the proton-donating species: protonated-glycine +H3NCH2COOH and H3O+ ions. A plot of the current density against the sum of the concentrations gives a single straight line passing through the origin. The phenomena are discussed in terms of electrodeposition processes of base metals.     

Multivariate evaluation of prognostic determinants for renal cell carcinomas which are metastatic at initial diagnosis

To clarify the relative importance of clinicopathological factors potentially affecting the survival of individuals initially diagnosed as having metastatic renal cell carcinoma (RCC), univariate and multivariate analyses using Cox's proportional hazards model were performed for 111 RCC patients who were admitted to four hospitals in Nagoya, Japan, between 1978 and 1993. Survival time was calculated from the date of diagnosis to the date of death or the end of May, 1995. Nineteen factors (17 clinically applicable before treatment and 2 histological in nature) were included for assessment. Univariate analysis revealed that 10 of the total 19 factors were significantly associated with patient survival. Multivariate analysis found 7 factors to be statistically significant determinants. Survival was further evaluated by categorizing the patients into three groups according to the number of the 7 factors. These groups showed clearly different survivals (log-rank test, p < 0.0001), confirming the importance of the 7 factors as definite determinants. They should therefore prove to be of advantage for classifying metastatic RCC patients when designing clinical prospective studies of immunotherapy and chemotherapy.     

Effect of annealing on d.c. conductivity of V2O5-SnO-TeO2 glasses

The d.c. conductivity (σ) of V₂O₅-SnO-TeO₂ glasses prepared by the press-quenching method was studied at temperatures from room temperature (RT) to 473 K, and the effect of annealing on σ was investigated. The conductivity of 50V₂O₅·20SnO·30TeO₂ glass was determined to be 3.98×10⁻⁴ Scm⁻¹ at 473 K and was unchanged for annealing (6–48 h) at 493 K, lower than T_g = 501 K, while its density increased with annealing time. These glasses were found to be n-type semiconductors, and the conduction was confirmed to be due to adiabatic small polaron hopping for V₂O₅ ≧ 50 mol%, and non-adiabatic for V₂O₅ < 50 mol%. The activation energy for conduction, W, decreased with annealing time. Variations in oxygen molar volume of the glasses with annealing time inferred a change in glass structure, from loosely to closely packed, resulting in a decrease in vanadium ion spacing with annealing. This caused an increase in the polaron band width, producing a decrease in polaron hopping energy and W. The effect of annealing time on the density of 50V₂O₅·20SnO·30TeO₂ glass was explained adequately by Winter's formula.     

Visual learning and recognition of 3-d objects from appearance

The problem of automatically learning object models for recognition and pose estimation is addressed. In contrast to the traditional approach, the recognition problem is formulated as one of matching appearance rather than shape. The appearance of an object in a two-dimensional image depends on its shape, reflectance properties, pose in the scene, and the illumination conditions. While shape and reflectance are intrinsic properties and constant for a rigid object, pose and illumination vary from scene to scene. A compact representation of object appearance is proposed that is parametrized by pose and illumination. For each object of interest, a large set of images is obtained by automatically varying pose and illumination. This image set is compressed to obtain a low-dimensional subspace, called the eigenspace, in which the object is represented as a manifold. Given an unknown input image, the recognition system projects the image to eigenspace. The object is recognized based on the manifold it lies on. The exact position of the projection on the manifold determines the object's pose in the image.A variety of experiments are conducted using objects with complex appearance characteristics. The performance of the recognition and pose estimation algorithms is studied using over a thousand input images of sample objects. Sensitivity of recognition to the number of eigenspace dimensions and the number of learning samples is analyzed. For the objects used, appearance representation in eigenspaces with less than 20 dimensions produces accurate recognition results with an average pose estimation error of about 1.0 degree. A near real-time recognition system with 20 complex objects in the database has been developed. The paper is concluded with a discussion on various issues related to the proposed learning and recognition methodology.     

Evaluation of the Fatigue Characteristics of Laser-processed Hot Work Tool Steel Based on Reliability

It is reported that laser-processing is effective to repair the heat checks, which are fine shallow cracks on a surfaceof die-casting dies.     

Nb3Al AND Nb3(Al,Ge) SUPERCONDUCTING TAPES BY LASER BEAM ANNEALING

Nb₃Al AND Nb₃(Al,Ge) tapes with excellent superconducting properties have been fabricated using high energy density laser beam irradiation, irradiations were carried out continuously on Nb-25at%AI and Nb-20at%Al -5at%Ge tapes prepared by powder metallurgical processing. With the high power density and short irradiation time, the tape could be heated and cooled much faster than a tape heat treated by conventional methods. The results were fine structure and large critical current density J_c values at high magnetic fields. J_c at 23 Tesla was over 10⁴ A/cm². This value was much greater than that obtained from a commercial Nb₃Sn superconductor. New continuous irradiation systems have been developed for scale-up development. Nb₃Al tapes 10 m in length were successfully fabricated. There was some scatter in J_c along the tape length. Small coil tests in magnetic fields indicated that the tape had excellent stability against a flux jump and mechanical strain.     

Synthesis of l-theanine using enzyme/mesoporous silica conjugates under high pH conditions

We present a new enzymatic process for synthesis of l-theanine using glutaminase combined with immobilization technique on a mesoporous silica (MPS). The MPS was firstly attempted to modify with zirconia in order to enhance the durability against the reaction under high pH conditions. The glutaminase on the MPS successfully catalyzed the reaction for the synthesis of l-theanine. The glutaminase/MPS conjugate was subsequently recovered and employed for the reaction again. The conjugate showed the corresponding activity to the first synthesis. This indicates that the conjugate functions as a catalyst for synthesis of l-theanine, having the operational stability sufficient for reuse.