Remarkable improvement of NOx–PM trade-off in a diesel engine by means of bioethanol and EGR

In order to realize a premixed compression ignition (PCI) engine, the effects of bioethanol–gas oil blends and exhaust gas recirculation (EGR) on PM–NO_x trade-off have been investigated focusing on ignition delay, premixed combustion, diffusion combustion, smoke, NO_x and thermal efficiency. The present experiment was done by increasing the ethanol blend ratio and ethanol and by increasing the EGR ratio in a single cylinder direct injection diesel engine. It is found that a remarkable improvement in PM–NO_x trade-off can be achieved by promoting the premixing based on the ethanol blend fuel having low evaporation temperature, large latent heat and low cetane number as well, in addition, based on a marked elongation of ignition delay due to the low cetane number fuel and the low oxygen intake charge. As a result, very low levels of NO_x and PM, which satisfies the 2009 emission standards imposed on heavy duty diesel engines in Japan, were achieved without deterioration of brake thermal efficiency in the PCI engine fuelled with the 50% ethanol blend diesel fuel and the high EGR ratio. It is noticed that smoke can be reduced even by increasing the EGR ratio under the highly premixed condition.     

An analysis of a firm’s capacity in Mazda’s Keiretsu

Capacity is defined as the power resulting from the specific position of a company in a network organization. This article extends the theory of network organizations to examine Mazda’s Yokokai Keiretsu, and proposes a new approach to calculating a firm’s capacity in a network. Capacity is divided into two categories, take-in capacity and take-out capacity, and the gap between them is called the capacity difference. We analyze the impact of capacity difference as a determinant of corporate performance in network organizations, thus providing a new perspective for successful corporate management.     

Effects of a membrane formation in the spatial prisoner’s dilemma

A cooperative relationship has been developed among individuals. However, altruistic behavior has little advantage against selfish behavior in the sense of rational terms. If each individual chooses selfish behavior pursuing their own payoff, then altruistic behavior will vanish. Earlier studies proposed mechanisms based on game theory which explained the problem of the difference between theoretical predictions and observation. Furthermore, those studies also considered the mechanisms of protecting a cooperator’s cluster in a spatial prisoner’s dilemma involving spatial strategies and spatial generosity, although they did not rigorously analyze the effects of the membrane for the cooperators. In this article, we report the quantitative effect of the membrane for protecting the cooperators from the exploitation of the defectors.     

Some Attempts at Reducing the Noise of Shuttle Looms

An investigation is described in which several attempts were made to reduce the noise in a shuttle-weaving mill by remodelling the main noise sources on a loom and by enclosing tbe loon in a soundproof cover. It is shown that a marked reduction in the noise level was achieved by enclosure of the picking mechanism. Soundproof looms based on the observations reported have been developed.     

Experimental Investigation and Thermodynamic Calculation of the Phase Equilibria in the Al-Bi-Sn Ternary System

This work first deals with the experimental investigation and thermodynamic calculation in the Al-Bi-Sn ternary system. The phase equilibria at 400 and 500 °C in the Al-Bi-Sn ternary system have been experimentally determined by electron probe microanalysis (EPMA) on the equilibrated alloys. Based on the experimental data determined in the present work, the phase equilibria in the Al-Bi-Sn ternary system have been thermodynamically assessed by using the CALPHAD (CALculation of PHAse Diagrams) method, and a consistent set of thermodynamic parameters leading to reasonable agreement between the calculated results and experimental data was obtained. The additions of Sn can effectively reduce the stable liquid miscibility gap in the Al-Bi binary system and gradually decrease its critical temperature. And the additions of Bi can significantly stabilize the metastable liquid miscibility gap in the Al-Sn binary system. This is shown by an initial decrease in critical temperature with increasing Bi additions.     

Characteristic Analysis of a Micro DC‐DC Converter for Portable Electronic Devices and an Improvement of Transient Response Characteristic

This paper describes the characteristic analysis of a micro DC‐DC converter which integrates inductor, controller and switching devices, and the improvement of the transient response characteristic. The steady‐state operation and the efficiency characteristics of the micro DC‐DC converter are presented as experimental data. The static characteristics are theoretically analyzed with consideration of the DC current characteristics of the inductor. The load transient response characteristics of the micro DC‐DC converter are also analyzed experimentally and theoretically. In addition, the factors responsible for the overshoot and undershoot of the output voltage when the load changes are discussed. Finally, a clamp circuit for reducing the overshoot and undershoot of the output voltage when the load changes is proposed. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 175(3): 56–64, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21081     

Corrosion of high purity Mg, AZ91, ZE41 and Mg2Zn0.2Mn in Hank’s solution at room temperature

This work compared the corrosion of typical Mg alloys (AZ91, ZE41 and Mg2Zn0.2Mn) and high purity (HP) Mg in Hank’s solution at room temperature and in 3% NaCl saturated with Mg(OH)₂. Corrosion was characterised by the evolved hydrogen and the surfaces after immersion. Corrosion in Hank’s solution was weakly influenced by microstructure in contrast to corrosion in the 3% NaCl solution. This is attributed to the formation of a more protective surface film in Hank’s solution, causing extra resistance between the α-Mg matrix and the second phase. The alloys with substantial Zn contents had a shorter incubation period in Hank’s solution.     

Novel function of rare catechin, epigallocatechin-3-(3''-O-methyl)gallate, against cold injury in primary rat hepatocytes

Epigallocatechin-3-(3'-O-methyl)gallate (EGCg-3'-OMe) is a rare component in green tea leaf and its bioactivity is hardly known. In this paper, we report that EGCg-3'-OMe has the function for cold preservation of primary rat hepatocytes. Confluent primary cultured hepatocytes were suspended in a storage solution, culture medium or cell banker (CB). EGCg-3'-OMe was tested as a supplement in the storage solution together with a general cryoprotectant, dimethylsulfoxide (DMSO). After 24 h cold preservation of cells at 4 degrees C followed by 1 h rewarming, cell viability and urea-synthesizing activity, one of the most important liver functions, were measured. EGCg-3'-OMe dose-dependently maintained cell viability and this effect was equal to that of a commercial CB at the highest concentration. Cell viability was also maintained after a further 24 h incubation at 37 degrees C of the cold-preserved hepatocytes. Conversely, urea-synthesizing activity was dose-dependently reduced by EGCg-3'-OMe. Cell protection by EGCg-3'-OMe due to the decrease in metabolic activity in cold-preserved cells was suggested. The decreased hepatic function of cells caused by EGCg-3'-OMe was rescued after a further 24 h incubation of cells at 37 degrees C.