Improved switching table for direct power control of three-phase PWM rectifier

The switching table based direct power control (ST-DPC) of three-phase PWM rectifier is analysed and an improved switching table (IST-DPC) is presented. The proposed switching schedule improves the quality of line current and results in better dynamic performances. In addition, the predictive direct power control (PDPC) of three-phase boost rectifier is presented and simulation results (in MATLAB/SIMULINK environment) are compared with those generated by ST-DPC and ISD-DPC approaches. Advantages and limitations of each control scheme are highlighted and conclusions regarding applications, quality of current waveforms and burden of calculations are presented

Investigating fish purchase patterns and preferences among the consumers of Sari

The present study aimed at looking into the fish consumption preferences and purchase patterns among 266 households of Sari in order to identify the fish market at Mazandaran province. To do so, a questionnaire was provided to be administered among consumers to state their preferences towards the type of fish species, purchased forms of fish as well as fish purchasing pattern in their family. Descriptive statistics as well as referential analysis was conducted through Friedman Test. Results showed that meat consumption priority among the households of Sari constituted the consumption of poultry meat, lamb, fish and beef, respectively. As to the investigation of fish purchase pattern, it was that almost two-thirds of households in Sari bought fish less than once a month and only a few percentage of them (4.1 percent) purchased them on a weekly basis. It was also revealed that consumers in Sari prefer marine fish more than farmed fish, and cold-water fish more than warm-water fish. Fresh, live and canned fish were the preferred forms of purchase for the consumers in Sari, and other forms of fish such as frozen, smoked and salted fish (total 7.9 percent) were rarely preferred by the consumers. Findings of the current research can contribute to powerful decision-making of companies and suppliers in terms of which product should be provided to the market for more sale. Therefore, recognizing the needs and desires of consumers and understanding their purchase behavior are effective steps to meet their expectations and ultimately increasing fish consumption

Induction motor load generator system using direct torque control method

Implementation of complicated tests for electrical machines usually demands special experimental setups and equipments. Getting to this target, electrical machine test benches are designed and constructed. In this paper, a direct torque controlled (DTC) load generator based on space vector modulation is proposed. To realize system performance with DTC method, classical DTC has been analyzed and is used for modelling the dynamometer. The performance of proposed dynamometer is investigated by simulating different parts of the system in SIMULINK/MATLAB environment and results are presented for several industrial load profiles

Cas Adaptor Proteins Coordinate Sensory Axon Fasciculation.

Development of complex neural circuits like the peripheral somatosensory system requires intricate mechanisms to ensure axons make proper connections. While much is known about ligand-receptor pairs required for dorsal root ganglion (DRG) axon guidance, very little is known about the cytoplasmic effectors that mediate cellular responses triggered by these guidance cues. Here we show that members of the Cas family of cytoplasmic signaling adaptors are highly phosphorylated in central projections of the DRG as they enter the spinal cord. Furthermore, we provide genetic evidence that Cas proteins regulate fasciculation of DRG sensory projections. These data establish an evolutionarily conserved requirement for Cas adaptor proteins during peripheral nervous system axon pathfinding. They also provide insight into the interplay between axonal fasciculation and adhesion to the substrate

A survey on surfactant concentration in southern Caspian Sea

We determined concentration of surfactants as mg/I of LAS using Sublation-Methylen Blue method in the south Caspian Sea coastal areas extending from Astara to Bandar-e-Tourkaman. The method was based on the American Standard Method for Examination of Water and Wastewater. We analyzed 53 water samples and found an average surfactant concentration of 0.019mgi1 with the minimum and maximum being 0.008mg/I and 0.038mgi1 respectively. We conclude that presently, surfactant concentration is not critical in the coastal areas. However, care must be exercised interpreting these results considering the synergistic effects between the surfactants and heavy metals and oil hydrocarbons

Retinoic acid effects on nuclear maturation of bovine oocytes in vitro

In the present study, the effect of all-trans retinoic acid (t-RA) administration during in vitro maturation (IVM) on bovine oocytes maturation was determined. Concentrations of t-RA (RA; 0, 0.25, 0.5 and 1 μM) and 0.1% ethanol (vehicle) were included in the maturation medium. Ovaries collected from the local abattoir were transported to the laboratory in in 0.9% NaCl with 100 IU/ml penicillin and 100 in vitro maturation (IVM) on bovine oocytes maturation was determined. Concentrations of t-RA (RA; 0, 0.25, 0.5 and 1 μM) and 0.1% ethanol (vehicle) were included in the maturation medium. Ovaries collected from the local abattoir were transported to the laboratory in in 0.9% NaCl with 100 IU/ml penicillin and 100  in vitro maturation (IVM) on bovine oocytes maturation was determined. Concentrations of t-RA (RA; 0, 0.25, 0.5 and 1 μM) and 0.1% ethanol (vehicle) were included in the maturation medium. Ovaries collected from the local abattoir were transported to the laboratory in in 0.9% NaCl with 100 IU/ml penicillin and 100 g/ml streptomycin at 30 - 35°C within 1-2 h after collection. The oocytes of antral follicles, 2 to 8 mm in diameter, were recovered by aspiration. After preliminary evaluation, the oocytes were selected and washed four times in HEPES-TCM 199 supplemented with 2% FBS, 0.2 mM sodium pyruvate, 100 IU/ml penicillin and 100 g/ml streptomycin. Then 10 cumulus-oocyte complexes (COCs) were subjected to each droplet of maturation medium and incubated at 38.5°C, 5% CO2 and 95% humidity for 24 h. Maturation medium was bicarbonate-buffered TCM199 supplemented with 10% FBS, 0.2 mM sodium pyruvate, 5 μg/ml bovine FSH, 0.01 IU/ml bovine LH, 100 IU/ml penicillin and 100 g/ml streptomycin. Results show different concentrations of t-RA have no effect on cumulus expansion. The rate of oocytes developing to the MII stage compared to control, vehicle, and 0.25 μM groups was significantly increased with 1 μM t-RA treatment (

Influence of palm oil fuel ash on physico-mechanical properties of prepacked aggregate concrete

Prepacked aggregate concrete (PAC) is a special type of concrete which is made by placing coarse aggregate in a formwork and injecting a grout either by pump or under gravity force to fill the voids. Utilization of pozzolanic materials in traditional concrete has become increasingly extensive, and this trend is expected to continue in prepacked concrete as well. Palm oil fuel ash (POFA) is one of the pozzolanic ashes, which has been recognized as a good pozzolanic material. This paper presents the results of some experimental tests on the performance behavior of POFA in developing physical and mechanical properties of prepacked aggregate concrete. Four concrete mixes namely prepacked concrete with 100% OPC as control, and PAC with 10%, 20% and 30% POFA were cast, and the temperature growth due to heat of hydration in all the mixtures was recorded. It has been found that POFA significantly reduced the temperature rise in prepacked concrete. The compressive and tensile strength, however, increased with replacement of POFA. The results obtained and the observation made in this study suggest that the replacement of OPC by POFA is beneficial, particularly for prepacked mass concrete where thermal cracking due to extreme heat rise is of great concern