Changes in hepatic key enzymes of dairy calves in early weaning production systems

The objective of the present study was to describe plasma hormonal and metabolite profile and mRNA expression levels and activities of the enzymes pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEPCK), and acetyl-coenzyme A (CoA) carboxylase in the liver of male Holstein calves before (1 and 3 wk of age) and after (8, 13, and 19 wk of age) weaning at 6 wk of age. The mean plasma concentration of acetate and β-hydroxybutyrate increased, and that of plasma lactate and nonesterified fatty acids decreased with week, particularly after weaning. Plasma glucose concentration was lowest at 8 wk of age. The mean plasma concentration of insulin and glucagon did not change with time, and that of cortisol was greatest at 1 wk of age. In the liver, enzyme activity of PC was greatest at 1 wk of age and decreased with time. There was a significant relationship between the activity and the mRNA level for PC. Activity of PEPCK also decreased with week. Acetyl-CoA carboxylase activity tended to decrease with week, and activity at 13 wk of age was lower than that at other times. Expression of PC mRNA, but not that of PEPCK and acetyl-CoA carboxylase α, decreased with week. We conclude that the hepatic gluconeogenic enzymes and acetyl-CoA carboxylase activities tend to decrease with age, reflecting changes in plasma metabolites in early weaning production systems.     

Hardware‐oriented ant colony optimization and its application to dynamic route guidance problem

Ant colony optimization (ACO) is based on the behavior of food gathering of ants and it is a powerful search tool particularly when applying it to combinatorial optimization problems. However, ACO has the inherent problem of substantial processing time, because it requires a lot of repetitive calculations. In this article, we propose novel hardware‐oriented ACO (H‐ACO) to reduce processing time. H‐ACO adopts new integer arithmetic instead of conventional floating point arithmetic in the optimization process and it achieves high‐speed processing while keeping the quality of solutions. In addition, H‐ACO reduces the hardware resources, accelerates the clock frequency, and improves the latency, if it is implemented as a dedicated hardware. Furthermore, we also propose a new route guidance algorithm which combines H‐ACO with Dijkstra's algorithm and it can be applied to a dynamic route guidance problem. Experiments using actual map data demonstrate the validity of the proposed route guidance algorithm. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Preparation and electrochemical properties of pure lithium cobalt oxide films by electron cyclotron resonance sputtering

Positive Li–Co–O films for all-solid-state thin-film lithium batteries were prepared by electron cyclotron resonance (ECR) sputtering using Li_xCoO₂ targets (x = 1.0, 1.2, 1.7 and 2.0). The Li–Co–O films prepared using the x = 1.0, 1.2 and 1.7 targets contained a Co₃O₄ impurity phase with high-temperature phase LiCoO₂. The film prepared using the x = 2.0 target was found to contain only a pure LiCoO₂ phase by Raman spectrometry and the inductively coupled plasma/atomic emission spectrometry (ICP/AES) method, and a thin-film battery using this film exhibited good electrochemical properties as a result of the improved utilization of the positive film.     

Determination of potent odorants in apple by headspace gas dilution analysis

Gas chromatography-olfactometry with headspace gas dilution analysis was used to evaluate the odor potencies of volatile compounds in Fuji apple. To improve the resolution of volatile compounds, the dilution analysis was conducted on two types of capillary columns with different polarities. Thirty three and 20 compounds were identified on DB-WAX and DB-5 columns, respectively. Methyl 2-methylbutanoate, isobutyl acetate, ethyl butanoate, ethyl 2-methylbutanoate, isopentyl formate, butyl acetate and hexyl acetate as well as hexanal were important odor contributors in the headspace gas of apple on the basis of high Flavor Dilution (FD) factors. Threshold values-in-air of these compounds were also estimated from the relationships between their FD factors and concentrations. Methyl 2-methylbutanoate and ethyl 2-methylbutanote were considered as the most potent odorants because of their lowest threshold values. In addition, the threshold values-in-air of isopentyl formate, isopentyl acetate and butyl isobutanoate, which have never been reported, were estimated at 0.149, 1.95 and 0.00607 μl/l, respectively.     

Characteristics of neutralization of acids by newly isolated fungal cells

Soil microorganisms play an important role in maintaining soil pH at levels suitable for other soil organisms. To clarify the biological neutralization mechanism in soil, we isolated soil microorganisms showing a high ability to neutralize acids and studied their characteristics. From our taxonomic study, three isolated strains were identified as filamentous fungi, namely Mucor sp., Aspergillus fumigatus, and Aureobasidium pullulans. These strains could secrete basic materials, such as ammonia, for neutralization, grow in the medium at pH 4.0 and increase the pH of the medium to approximately 8.0. These microbial cells could neutralize not only nitric acid but also sulfuric and hydrochloric acids. The strains could also grow by utilizing nitric acid as a sole nitrogen source. In the soil containing these organisms, the pH was maintained in the neutral range by the buffering action of basic materials that they secrete. These results suggest that these fungal cells are useful for protecting the soil from acidification by acid rain.     

Characterization of electrical properties and photosensitivity of SnS thin films prepared by the electrochemical deposition method

Using the electrochemical deposition (ECD) method, we prepared tin sulfide thin films, which are suitable for the absorption layer in solar cells because of its bandgap energy (1 eV). We first optimized pulse-form biasing for ECD by characterizing deposited samples with scanning electron microscope, Auger electron spectroscopy and X-ray diffraction measurements. Then, we investigated the electrical properties of deposited SnS thin films and the properties of contacts with several different metals. Furthermore, we observed the photoconductivity of the films by means of photoelectrochemical measurements. From these results, we confirmed that the SnS thin films show p-type conduction.     

Performance evaluation of membrane on catalyst module for hydrogen production from natural gas

We have been developing a hydrogen production module with a Pd-based membrane on catalyst (MOC) from natural gas. The MOC module is expected to be more compact and cheaper than the conventional hydrogen production module. To evaluate the hydrogen production performance of the MOC module and to clear the factor that dominates the effective hydrogen production, we compared the reforming performance of the catalytic support without hydrogen permeable membrane and the MOC module at various reaction conditions. As a result, it was cleared that hydrogen permeation through the membrane improves the methane conversion drastically in the MOC module by comparing with the support only module and changing the experimental conditions.     

The effect of neutron irradiation on the fiber/matrix interphase of silicon carbide composites

Given the good stability of mechanical properties of silicon carbide (SiC) under neutron irradiation, the ultimate irradiation tolerance of SiC composite materials may be limited by the fiber/matrix interphase, which is critically important to the performance of these composites. This study investigates the irradiation stability of pyrolytic carbon (PyC) monolayer and PyC/SiC multilayer interphases by tensile and single fiber push-out test techniques. Neutron irradiation was performed to doses of 0.7-7.7 dpa at temperatures from 380 to 1080 °C. Both interfacial debond shear strength and interfacial friction stress apparently decrease by irradiation, although this is not so dramatic when T_irr < 1000 °C. In contrast, the interfacial shear stresses are most affected by the higher temperature irradiation (>1000 °C). Noteworthy, these irradiation effects depend on the type of interphase material, i.e., for the pyrolytic carbon or multilayer SiC variants studied. In the range of irradiation temperature and dose, the degradation in interfacial shear properties, while measurable, is not of a magnitude to degrade the mechanical performance of the composites. This was observed for both interphase types studied. In particular, the proportional limit tensile stress decreases slightly by irradiation while the tensile fracture strength undergoes very minor change.     

Volume of a liquid drop detaching from a sphere

A theoretical and experimental study is conducted to investigate the detached volume from a pendant drop on the surface of a sphere. Observation of drop detachment by high‐speed video camera reveals that the movement of the upper part of the neck of the drop is quite slow compared to that of the detaching lower part. The surface profile of the upper part was calculated approximately as a static problem using the axisymmetric Laplace equation. Using the drop profile, the system energy, including the work done by the solid–liquid wetting behavior, was calculated. Based on the condition of minimum energy, the volume of the detached part V was calculated. The volume V increases with the sphere diameter and approaches the value for the pendant drop attached to a plate. In addition, V is strongly dependent on the wettability between the sphere and the liquid and decreases with the receding contact angle. The detached volume of the water drop was measured for spheres of porous brick of various diameters. The experimental and theoretical results were found to be in good agreement. © 2010 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/htj.20305