Design and analysis of zero cogging torque brusless DC motor for spaceeraft applications

Abstract Control moment gyroscopes (CMG) are used in modern satellite applications for attitude control of satellites References [1] S. P. Bhat and P. Tiwari, "Controllability of spacecraft attitude using control moment gyroscopes," IEEE Transactions on Automatic Control, vol. 54,NO. 3, pp. 585-590, March 2009. [2] R. P. Praven, "Design and analysis of zero cogging torque brusless DC motor for spaceeraft applications," Proc. International Conference ECTI-CON, pp. 254-258, May 2010

A practical culture technique for enhanced production of manganese peroxidase by Anthracophyllum discolor Sp4

In this study, different growth conditions of Anthracophyllum discolor Sp4 including the effect of agitation, additions of lignocellulosic support, inducer and surfactant were evaluated on the MnP production in Kirk medium using a culture system made up of the tubes containing the glass bead . The highest MnP production (1,354 U/L on day 13) was obtained when the medium was supplemented with wheat grain and 0.25 mM MnSO4 as inducer, under static conditions at 30°C. Two isoenzymes were purified (35 and 38 kDa respectively). MnP presented a maximal activity in the pH range between 4.5 and 5.5, a relatively high temperature tolerance (50ºC) and a high catalytic activity for 2,6-dimethoxyphenol and hydrogen peroxide

In vitro

In this study, in vitro and in vivo effects of some commonly used fungicides, antibiotics, and various chemicals on isolated and purified catalase from Phanerochaete chrysosporium were investigated. The catalase was purified 129.10-fold by using 60% ammonium sulfate and 60% ethanol precipitations, DEAE-cellulose anion exchange and Sephacryl-S-200 gel filtration chromatographies from P. chrysosporium growth in carbon- and nitrogen-limited medium for 12 days. The molecular weight of native purified catalase from P. chrysosporium was found to be 290 +/- 10 kDa, and sodium dodecyl sulfate (SDS)-PAGE results indicated that enzyme consisted of four apparently identical subunits, with a molecular weight of 72.5 +/- 2.5 kDa. Kinetic characterization studies showed that optimum pH and temperature, K-m and V-max values of the purified catalase which were stable in basic region and at comparatively high temperatures were 7.5, 30 degrees C, 289.86 mM, and 250,000 U/mg, respectively. The activity of purified catalase from P. chrysosporium was significantly inhibited by dithiothreitol (DTT), 2-mercaptoethanol, iodoacetamide, EDTA, and sodium dodecyl sulfate (SDS). It was found that while antibiotics had no inhibitory effects, 45 ppm benomyl, 144 ppm captan, and 47.5 ppm chlorothalonil caused 14.52, 10.82, and 38.86% inhibition of purified catalase, respectively. The inhibition types of these three fungicides were found to be non-competitive inhibition with the K-i values of 1.158, 0.638, and 0.145 mM and IC50 values of 0.573, 0.158, 0.010 mM, respectively. The results of in vivo experiments also showed that benomyl, captan and chlorothalonil caused 15.25, 1.96, and 36.70% activity decreases after 24-h treatments compared to that of the control

Relationship between organizational commitment and organizational silence: A study in the insurance industry

In the study, it was aimed to determine the effect of organizational commitment on organizational silence. In this context, the related research was conducted on 416 employees working in an insurance sector company in Istanbul. In the study, after the concepts of organizational commitment and organizational silence are presented in a theoretical framework, to measure organizational commitment; the scale of organizational commitment by Meyer and Allen, which Wasti and Can translated into Turkish and adapted, and the organizational silence scale developed by Dyne et al. (Journal of Management Studies 40(6), 1359–1392) was used to measure organizational silence. As a result of the questionnaires, the data were evaluated and the relationship between organizational commitment and organizational silence was tried to be explained. The results of multiple regression analysis, which measures the effect of organizational commitment on organizational silence, were interpreted by correlation analysis, which measures the relationships of organizational commitment and organizational silence subdimensions. The results of the T-tests and ANOVA (F) tests, which measure the relationship between demographic variables and research variables, are also included. As a result of the analyzes, it was found that among the subdimensions of organizational commitment, continuing commitment, normative and emotional commitment, only continuing commitment and emotional commitment had a significant effect on accepting silence