• Journal of Electrical Engineering and Technology
• /
• v.11 no.1
• /
• pp.117-124
• /
• 2016

Solar photovoltaic pumping system is one of most important of renewable energy applications especially in rural areas. Besides, the control strategy for standalone solar pumping system based on induction motor and without DC/DC converter has been widely studied and discussed in the literature. This topology is of great concern due its economic issues, especially when a standard frequency converter (SFCs) with scalar control is used instead of a dedicated PV inverter. This paper proposes an external control module to generate SFCs frequency reference in order to ensure both maximum power point tracking (MPPT). We present method of modeling and control of photovoltaic pumping system based centrifugal pump controlled by new improved incremental conductance in order to optimize the price and operation of pumping system this MPPT algorithm have many advantages like can be eliminate proportional integral controller It is a low cost solution since it requires no additional power equipment. The induction motor driven pump that is powered by a solar array is controlled by the indirect field oriented control (IFOC). The effectiveness of the proposed approach is illustrated by simulations carried out under Matlab Software. The experimental results are compared with simulation results.

• Korean Journal of Pharmacognosy
• /
• v.38 no.3 s.150
• /
• pp.258-262
• /
• 2007

In the present study, we investigated the antioxidant activity of methanol extract and its organic fractions (n-hexane, $CH_2Cl_2$, EtOAc, n-BuOH and $H_2O$) of Capsiccum annuum leaves against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. As results, methanol extract, and its ethyl acetate and n-butanol fractions showed good scavenging effect at 100 ${\mu}g/ml$. Four compounds were isolated from the ethyl acetate fraction through silica gel and Sephadex LH-20 column chromatographies. Their chemical structures were elucidated as apigenin (1), vanillic acid (2), uracil (3) and apigenin $7-O-{\beta}-D-apiofuranosyl(1{\rightarrow}2)-{\beta}-D-glucopyranoside$ (4) by comparison of spectral data with those in reference. $IC_{50}$ value of compound 2 was 14.7 ${\mu}g/ml$, while compounds 1, 3 and 4 had no effect on the DPPH radical.

• Journal of Sericultural and Entomological Science
• /
• v.39 no.1
• /
• pp.17-21
• /
• 1997

Oral application of fenoxycarb, O-ethyl N-(2-(4-phenoxyphenoxy)ethyl) carbamate, the commercial formulation Insegar, on the 1st day of the 3rd instar made no difference in the egg laying and the hatchability as compared to 750 grains for the number of eggs laid, 53 grains for the number of the resideual eggs unlaid, 749 grains for the number of fertirized eggs, 97% for the total hatchability, and 95% for the useful hatchability as in the control but on the first day of the 4th instar, the number of the remainder eggs in the ovary increased by 2.4 folds, and reduced number of the eggs laid, number of unfertilized eggs, the hatchabillity and useful hatchability by 39%, by 66%, by 68% and by 72%, respectively. When diluted Insegar was applied topically every other two days from the pupae to the moth at concentration of 10-6, 10-7, 10-8, 10-9, 10-10 the number of eggs laid, the number of the unfertilized eggs, the total hatchability and the useful hatchability were decreased. More severe decrease took place as concentration lowered and the earlier application.

• Journal of Wellbeing Management and Applied Psychology
• /
• v.2 no.2
• /
• pp.1-11
• /
• 2019

This study empirically examined the effect of female director on tax aggressiveness of listed insurance firms in Nigeria. The main objective of this research was to empirically investigate the effect of female board members on tax aggressiveness, determine the composition and representation of female directors on the board of insurance companies, find out how tax aggressive are listed insurance firms and apply the BLAU (1977) index method to measure female director representation as a departure from conventional approaches specifically in the Nigerian context in the reference period, 2014 to 2018. The population of the study consists of all the quoted insurance firms as at 31st December, 2016. A sample of twenty eight (28) quoted insurance firms was selected and data were collected over the period. Inferential statistic consisting of the General Method of Moment was used for the data analysis. The results obtained reveal that board size is negative and exerts significant impact on tax aggressiveness in insurance firms in Nigeria. The study therefore recommends that the Federal government has to come up with a policy to respond to the marginalization of female on the insurance firm corporate board in Nigeria. The aim of this policy thrust should be targeted at reducing politics and biasness against women on the corporate boards of listed insurance firms.

• Journal of Microbiology and Biotechnology
• /
• v.7 no.4
• /
• pp.250-257
• /
• 1997

A new sensing system based on the immobilization of luminescent bacteria, photobacterium phosphoreum, was proposed for continuous real-time monitoring of pollutants. The response curves demonstrate that Photobacterium phosphoreum immobilized on the strontium alginate were very sensitive to seven reference chemicals used. The significant inhibitory concentrations for bioluminescence emission were 5 ppm for Pb$(NO_3)_2$), $NiCl_2$, $CdCl_2$, 50 ppm for $NaASO_2$, 0.1 ppm for $HgCl_2$, 0.5 ppm for pentachlorophenol and less than 5 ppm for SDS, respectively. The alginate mixed-cells (AMC) retained their luminescence during experimental period (29 days) under storage condition of $-80^{\circ}C$. The variables affecting performance of continuous flow through monitoring (CFTM) was optimized in order to ensure stability and efficiency. The flow through cell with strontium-alginate immobilized luminescent bacteria was tested with salicylate and 4-nitrophenol. A rapid response of luminescence was recorded by time drive mode in bioluminescence spectrometer after exposure to both toxicants.

• Mass Spectrometry Letters
• /
• v.4 no.1
• /
• pp.18-20
• /
• 2013

Headspace solid phase micro-extraction gas chromatography/flame ionization detection (HS-SPME-GC/FID) method was compared with headspace gas chromatography/mass selective detection (HS-GC/MS). Organic solvent-spiked urine as well as urine samples from workspace was analyzed under optimal condition of each method. Detection limit of each compound by HS-SPME-GC/FID was $3.4-9.5{\mu}g/L$, which enabled trace analysis of organic solvents in urine. Linear range of each organic solvent was $10-400{\mu}g/L$, with fair correlation coefficient between 0.992 and 0.999. The detection sensitivity was 4 times better than HS-GC/MS in selected ion monitoring (SIM) mode. Accuracy and precision was confirmed using commercial reference material, with accuracy around 90% and precision less than 4.6% of coefficient of variance. Among 48 urine samples from workplace, toluene was detected from 45 samples in the range of $20-324{\mu}g/L$, but no other solvents were found. As a method for trace analysis, SPME HS GC/FID showed high sensitivity for biological monitoring of organic solvent in urine.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.3
• /
• pp.17-27
• /
• 2020

The research aims to investigate the impact levels of determinants on the conversion of financial statements from Vietnamese accounting standards (VAS) to International financial reporting standards (IFRS) in the multinational firms in Vietnam. The method of data collection was done through the survey and subjects are accountants in Multinational Firms doing business in Hanoi and ten neighboring provinces. After checking the information on the votes, there are 170 questionnaires with full information for data entry and analysis. We use Cronbach's Alpha, EFA analysis and run regression model to investigate the impact levels of each independent variable on dependent variable of the conversion of VAS financial statements to IFRS. The results show that five determinants including Economic, Politics, Law, Culture, and Conditions for implementation have positive relationships with the conversion of VAS financial statements to IFRS. In particular, Economic determinant is the most strongest. Based on the findings, some recommendations are given for improving the conversion of VAS financial statements to IFRS of multinational firms doing business in the context of Vietnam. The results are considered a useful reference for firms when making financial statements to transparently change the financial statement information and improve the quality of financial statement information.

• The Journal of Industrial Distribution & Business
• /
• v.9 no.2
• /
• pp.17-26
• /
• 2018

Purpose - The purpose of this study is to provide a formalized process of decision making for companies or organizations that need to make various decisions in the age of uncertainty. Therefore, this study aimed to proposes a strategic decision-making approach citing the relatively easily accessible using IPA(important-performance analysis) and SWOT/AHP analysis. Research design, data, and methodology - To be specific, the first step is to derive necessary attributes and conduct IPA. The second step is to subdivide the IPA results into internal strength and weakness factors and the external opportunity and threat factors, hierarchize those factors, and weight them accordingly. The third step is to build a causality model to propose a method of supporting a rational decision making. Results - The foregoing approach seems to facilitate the diversification of decision-making strategies by helping businesses or organizations to measure and analyze the attributes needed for certain decisions. Additionally, the perceived importance and satisfaction (or achievement) usage of those derived attributes can be used as the reference data for SWOT/AHP analysis. Conclusions - The proposed stepwise approach is applicable to businesses or organizations in need of making stepwise decisions in line with their retained competencies in comparison to conventional or intuitive decision-making practices.

• Journal of Computing Science and Engineering
• /
• v.7 no.3
• /
• pp.168-176
• /
• 2013

Long-term evolution (LTE) is emerging as a major candidate for 4G cellular networks to satisfy the increasing demands for mobile broadband services, particularly multimedia delivery. Multiple-input multiple-output (MIMO) technology combined with orthogonal frequency division multiple access and more efficient modulation/coding schemes (MCS) are key physical layer technologies in LTE networks. However, in order to fully utilize the benefits of the advances in physical layer technologies, the MIMO configuration and MCS need to be dynamically adjusted to derive the promised gains of 4G at the application level. This paper provides a performance evaluation of video traffic with variations in the physical layer transmission parameters to suit the varying channel conditions. A quantitative analysis is provided using the perceived video quality as a video quality measure (evaluated using no-reference blocking and blurring metrics), as well as transmission delay. Experiments are performed to measure the performance with changes in modulation and code rates in poor and good channel conditions. We discuss how an adaptive scheme can optimize the performance over a varying channel.

• Journal of Nutrition and Health
• /
• v.28 no.5
• /
• pp.434-441
• /
• 1995

The model rats with postmenopausal osteoporosis were comparatively observed with regard to the effects of bovine ash and calcium phosphate on calcium metabolism. The modelling design involved the five week-old week-old female SD-strain rats ovariectomized and fed a low-Ca diet(20% casein, 0.06% Ca and 0.38% P) for three weeks. The rats were divided into five groups, one of which was fed the low-Ca diet(basal), and the rest of which were divided into five groups, one of which was fed the low-Ca diet(basal), and the rest of which were fed four kinds of Ca-supplemental diets(20% protein, 1.06% Ca and 0.8% P) for three weeks. The Ca-suplements diets contained two kinds of Ca sources, bovine bone ash(BBA) or calcium phosphate, tribasic [Ca3(PO4)2] and two kinds of protein sources, casein or isolated soy protein(ISP). The model rats of postmenopausal osteoporosis fed basal diet showed a significant decrease in Ca utilization in reference to serum Ca concentration, breaking force of bone, Ca and P contents of bone, and Ca absorption and retention. However, the supply of Ca for three weeks demonstrated the improved utilization of Ca. One step further, BBA was more effective than calcium phosphate in improving Ca utilization in ISP-fed groups. On the other hand, no significant difference was seen in casein-fed groups. It is to conclude that BBA could be more effective in accelerating Ca utilization under vulnerable dietary or physiological conditions such as vegetable protein intake and osteoprosis.