• Bulletin of the Korean Chemical Society
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• v.28 no.3
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• pp.369-372
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• 2007

A fast and simple high-performance liquid chromatography (HPLC) method for the simultaneous determination of four pesticides having fungicide properties has been proposed for Panax ginseng, C. A. Meyer grown for 4, 5, or 6 years. Analytical separation was performed on C18 columns using ultraviolet detector under gradient conditions. Spiked blank samples were used as standards to counteract the matrix effect observed in the chromatographic determination. The HPLC response for all pesticides was linear, with determination coefficients > 0.9986. The average rate of recovery for pesticides spiked with 2 fortification levels was > 72% with relative standard deviations < 9%. The limits of quantification (LOQ) ranged from 0.03 to 0.16 ppm. These LOQs were lower than the respective maximum residue limits (MRL) established by the Korean Food and Drug Administration (KFDA), except for cyazofamid. The proposed method was used to determine pesticide residue levels in samples of ginseng obtained from Jeonnam Province (Republic of Korea). None of the pesticides were found in ginseng samples grown for 4, 5, or 6 years.

• The Korean Journal of Pain
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• v.24 no.2
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• pp.100-104
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• 2011

Background: Myofascial pain syndrome (MPS) is a regional musculoskeletal pain disorder that is caused by myofascial trigger points. The objective of this study was to determine the prevalence of MPS among chronic back pain patients, as well as to identify risk factors and the outcome of this disorder. Methods: This was a prospective observational study involving 126 patients who attended the Pain Management Unit for chronic back pain between 1st January 2009 and 31st December 2009. Data examined included demographic features of patients, duration of back pain, muscle(s) involved, primary diagnosis, treatment modality and response to treatment. Results: The prevalence of MPS among chronic back pain patients was 63.5% (n = 80). Secondary MPS was more common than primary MPS, making up 81.3% of the total MPS. There was an association between female gender and risk of developing MPS ($x^2$ = 5.38, P = 0.02, O.R. = 2.4). Occupation, body mass index and duration of back pain were not significantly associated with MPS occurrence. Repeated measures analysis showed significant changes (P < 0.001) in Visual Analogue Score (VAS) and Modified Oswestry Disability Score (MODS) with standard management during three consecutive visits at six-month intervals. Conclusions: MPS prevalence among chronic back pain patients was significantly high, with female gender being a significant risk factor. With proper diagnosis and expert management, MPS has a favourable outcome.

• Advances in materials Research
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• v.4 no.1
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• pp.45-60
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• 2015

This paper aimed to investigate the effect of MWCNTs on properties of slag Geopolymeric mortar. Geopolymeric matrices containing different MWCNTs concentrations (0.0, 0.1, 0.2, 0.3 and 0.4 % by weight of the used binder) were synthesized. The Geopolymer mortar composed of aluminosilicate slag to sand (1:2), while the alumino silicate source binder composed of 50% air cooled slag and 50%water cooled slag both passing a sieve of $90{\mu}m$, while the sand passing a sieve of 1 ml. The materials prepared at water/binder ratios in a range of 0.34-0.39% depending on the added MWCNT, whereas the Gelenium Ace-30 superplasticizer used in the ratio of 1.4-2.2% from the total dry weight for better dispersion of MWCNT under sonication for 15 min. Alkaline activation of the Geopolymer mortar was carried by using of 6% NaOH. Curing was performed under temperature of $40^{\circ}C$ and 100% R.H. Results showed that the addition of MWCNTs enhanced the resulting amorphous geopolymer structure with marked decrease in the drying shrinkage as well as water absorption specially when using 0.1% MWCNT, while further increase in MWCNTs results in agglomeration in MWCNT within the matrix and so hinder the propagation of Geopolymerization reaction and negatively affect the formed geopolymer structure.

• Journal of Marine Bioscience and Biotechnology
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• v.3 no.1
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• pp.42-47
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• 2008

Sudan is the largest country in Africa with an area of $2,505,810km^2$, of water constitutes $129,810km^2$, and cultivable land is 34%. Sudan has a total land boundary of 7,687 km with 9 border countries. This vast country embraces different vegetation patterns reflecting various climatic zones, grading from tropical rain forests in the south through semi-tropical savannah to arid zone in the extreme north, with annual rainfall ranging from 1,600 mm in the south to 25 mm in the north. The aquaculture industry is not developed as yet. Because of their basic characteristics, the Sudan inland and marine capture fisheries are of a small-scale and semi-industrial nature. The demand for fish and fish preparations is growing steadily. The animal resources sector (which includes fisheries) contributes 21% of Sudan GDP. The contribution of fisheries to Sudanese GDP is currently marginal. The per caput supply is only 1.6 kg/year, which is mostly obtained by capture fish landings. Despite the fact that fisheries GDP is extremely low, fish and fish preparations contribute to the food security of a wide sector of the rural and urban communities. Fisheries also provide work opportunities in the form of secondary employment as a source of income that indirectly contributes to household food security.

• Journal of the Korean Society of Systems Engineering
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• v.16 no.2
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• pp.1-15
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• 2020

Nuclear power plants in South Korea are operated to cover the baseload demand. Hence they are operated at 100% rated power and do not deploy power tracking control except for startup, shutdown, or during transients. However, as the contribution of renewable energy in the energy mix increases, load follow operation may be needed to cover the imbalance between consumption and production due to the intermittent nature of electricity produced from the conversion of wind or solar energy. Load follow operation may be quite challenging since the operators need to control the axial power distribution and core reactivity while simultaneously conducting the power maneuvering. In this paper, a systems engineering approach for multi-physics load follow simulation of APR1400 is performed. RELAP5/SCDAPSIM/MOD3.4/3DKIN multi-physics package is selected to simulate the Korean Advanced Power Reactor, APR1400, under load follow operation to reflect the impact of feedback signals on the system safety parameters. Furthermore, the systems engineering approach is adopted to identify the requirements, functions, and physical architecture to provide a set of verification and validation activities that guide this project development by linking each requirement to a validation or verification test with predefined success criteria.

• Steel and Composite Structures
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• v.38 no.5
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• pp.583-597
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• 2021

This article develops a nonclassical model to analyze bending response of squared perforated microbeams considering the coupled effect of microstructure and surface stress under different loading and boundary conditions, those are not be studied before. The corresponding material and geometrical characteristics of regularly squared perforated beams relative to fully filled beam are obtained analytically. The modified couple stress and the modified Gurtin-Murdoch surface elasticity models are adopted to incorporate the microstructure as well as the surface energy effects. The differential equations of equilibrium including the Poisson's effect are derived based on minimum potential energy. Exact closed form solution is obtained for bending behavior of the proposed model considering the classical and nonclassical boundary conditions for both uniformly distributed and concentrated loads. The proposed model is verified with results available in the literature. Influences of the microstructure length scale parameter, surface energy, beam thickness, boundary and loading conditions on the bending behavior of perforated microbeams are investigated. It is observed that microstructure and surface parameters are vital in investigation of the bending behavior of perforated microbeams. The obtained results are supportive for the design, analysis and manufacturing of perforated nanobeams that commonly used in nanoactuators, nanoswitches, MEMS and NEMS systems.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.7
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• pp.63-79
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• 2022

Past studies on the influence of corporate social responsibility (CSR) activities on firms have been inconsistent, highlighting the significance of examining how CSR affects the performance of Malaysian government-linked companies (GLCs). The study aims to investigate the impact of CSR dimensions (economic, legal, ethical, and philanthropic) on firm performance from 2016 to 2020 using a sample of 31 GLCs from the top 100 companies under the Main Board of Bursa Malaysia. A total of 35 GLCs were selected as the study sample size based on the top 100 businesses listed under the board of Bursa Malaysia as of 31 December 2020. The study employed correlation and multiple linear regression models to examine the relationship between CSR dimensions and firm performance. Financial performance is evaluated using accounting-based models of return on assets (ROA) and return on equity (ROE) and market-based models of earnings per share (EPS) and market value (MV). The CSRHub database was employed to collect information on the performance of company CSR dimensions. The findings suggested a significant positive relationship between ethical and philanthropic CSR and firm performance regarding ROE. Thus, GLCs prioritized ethical and philanthropic CSR over other dimensions.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.4
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• pp.381-389
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• 2022

Studies examining the interplay between brand transgression and brand forgiveness is notably sparse especially in the context of Southeast Asian banking customers. The purpose of this research is to add to the existing literature by examining the impact of brand transgression, which is represented by negative past experience image incongruence, and corporate wrongdoing on brand forgiveness among Islamic banking customers in Malaysia. The increasing surge in interest in unfavorable brand relationships has sparked concerns about its impact on brand forgiveness. As a result, this theoretical argument, which lacks empirical proof, has to be statistically tested. The current study was conducted utilizing a non-probability purposive sampling technique among clients in the Klang Valley who had poor experiences with Islamic banking services. Data analysis included descriptive statistics, exploratory factor analysis, and multiple regression on a total of 211 valid replies. The findings show that two elements of brand transgression, image inconsistency, and corporate wrongdoing, have a major impact on brand forgiveness. However, the other dimension namely negative past experience was found to be non-significant to brand forgiveness. Research implications and directions for future studies are also discussed in this paper.

• Coupled systems mechanics
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• v.12 no.4
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• pp.315-335
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• 2023

The building sector has seen a huge increase in the use of lightweight concrete recently, which might result in saving in both cost and time. As a result, the study has been done on various types of concrete, including lightweight (LC), heavyweight (HC), and ordinary concrete (OC), to understand how they react to earthquake loads. The comparisons between their responses have also been taken into account in order to acquire the optimal reaction for various materials in building work. The findings demonstrate that LWC building models are more earthquake-resistant than the other varieties due to the reduction in building weight which can be a curial factor in the resistance of earthquake forces. Another crucial factor that was taken into study is the combination of various types of concrete [HC, LC, and OC] in the structural components. On the other hand, the bending moments and shear forces of LC had reduced to 17% and 19%, respectively, when compared to OC. Otherwise, the bending moment and shear force demand responses in the HC model reach their maximum values by more than 34% compared to the reference model OC. In addition, the results show that the LCC-OCR (light concrete column and ordinary concrete roof) and OCC-LCR (ordinary concrete for the column and light concrete for the roof) models' responses have fewer values than the other types.

• Steel and Composite Structures
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• v.49 no.6
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• pp.667-684
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• 2023

In the context of finite element method, a computational simulation is presented to study and analyze the dynamic behavior of regularly perforated functionally graded rotating beam for the first time. To investigate the effect of perforation configurations, both regular circular and squared perforation patterns are studied. To explore impacts of graded material distributions, both axial and transverse gradation profiles are considered. The material characteristics of graded materials are assumed to be smoothly and continuously varied through the axial or the thickness direction according the nonlinear power gradation law. A computational finite elements procedure is presented. The accuracy of the numerical procedure is verified and compared. Resonant frequencies, axial displacements as well as internal stress distributions throughout the perforated graded rotating cantilever beam are studied. Effects of material distributions, perforation patterns, as well as the rotating beam speed are investigated. Obtained results proved that the graded material distribution has remarkable effects on the dynamic performance. Additionally, circular perforation pattern produces more softening effect compared with squared perforation configuration thus larger values of axial displacements and maximum principal stresses are detected. Moreover, squared perforation provides smaller values of nondimensional frequency parameters at most of vibration modes compared with circular pattern.