• Journal of Microbiology and Biotechnology
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• v.22 no.5
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• pp.592-599
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• 2012

Bacillus licheniformis ${\alpha}$-amylase (BLA), a thermophilic counterpart of Bacillus amyloliquefaciens ${\alpha}$-amylase (BAA), is an appropriate model for the design of stabilizing mutations in BAA. BLA has 10 more histidines than BAA. Considering this prominent difference, in the present study, three out of these positions (I34, Q67, and P407; located in the thermostability determinant 1 region and Ca-III binding site of BAA) were replaced with histidine in BAA, using the site-directed mutagenesis technique. The results showed that the thermostability of P407H and Q67H mutants had increased, but no significant changes were observed in their kinetic parameters compared to that of the wild type. I34H replacement resulted in complete loss of enzyme activity. Moreover, fluorescence and circular dichroism data indicated a more rigid structure for the P407H variant compared with that of the wild-type BAA. However, the flexibility of Q67H and I34H mutants increased in comparison with that of wild-type enzyme.

• Journal of Integrative Natural Science
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• v.4 no.2
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• pp.91-98
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• 2011

Quantitative structure-activity relationships (QSAR) have been applied for two decades in the development of relationships between physicochemical properties of chemical substances and their biological activities to obtain a reliable statistical model for prediction of the activities of new chemical entities. The fundamental principle underlying the QSAR is that the structural difference is responsible for the variations in biological activities of the compounds. In this work, we developed 3D-QSAR model for a series of 5-Lipoxygenase inhibitors, utilizing comparative molecular field analysis (CoMFA) and Topomer CoMFA methodologies. Our developed models addressed superiority of Topomer CoMFA over CoMFA. The CoMFA model was obtained with $q^2$=0.593, $r^2$=0.939, $Q^2$=0.334 with 6 optimum number of components (ONC). Higher statistical results were obtained with the Topomer CoMFA model ($q^2$=0.819, $r^2$=0.947, ONC=5). Further robustness of developed models was checked with the ANOVA test and it shows F=113 for CoMFA and F=162.4 for Topomer CoMFA model. Contour map analysis indicated that the more requirement of electrostatic parameter for improved potency.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.226-226
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• 2010

Microstructure, magnetic and transport properties of as-deposited electron-doped $La_{1-x}Ce_xMnO_3$ and hole-doped $La_{1-x}Ce_xMnO_3$ films prepared by pulse laser deposition, with x = 0.1 and 0.3, have been investigated. The microstructural analysis reveals that the $La_{1-x}Ce_xMnO_3$ films have a column-like microstructure and a strip-domain phase with a periodic spacing of about 3c, which were not found for the $La_{1-x}Ce_xMnO_3$ ones. At the same time, the experimental results manifest that there is no fundamental difference in the magnetic and the transport properties between electron- and hole-doped manganite films, except the appearance of ferromagnetic response in the low-doped $La_{0.9}Ce_{0.1}MnO_3$ film at temperatures above the Curie point. The observed magnetic behavior, typical for the Griffiths-like phase, for this film is explained by the percolation mechanism of the ferromagnetic transition and by the presence of strip-domain phase which stimulates the magnetic phase separation.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.8
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• pp.453-463
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• 2021

The current study aims to investigate the relationship between CSRD and firm performance, as an indicator for corporate socially responsible behavior, and corporate market performance of listed companies on the Amman stock exchange (ASE). The study adopts a quantitative methodology and utilizes pooled data sets that was collected following content analysis approach of the annual reports for the period 2014 to 2019. The study sample consists of 42 listed companies. The study ran a multiple regression model in order to capture the relationship between the independent variable CSRD and the dependent variable that is Firm performance which was measured using Tobin's Q. The study also utilized five control variables in order to control the hypothesized relationship between CSRD and Firm Performance. The results indicate a negative but significant relationship between CSRD and corporate market performance measured by Tobin's Q. The results stand against the notion of the business case for CSR, and indicate the opposite position, so, the higher CSRD, the lower will be Tobin's Q. Such results support the notion of the institutional theory, and provide an initial evidence for legitimacy seeking behavior in Jordanian companies. However, the results indicate a lower level of awareness of CSR across investors and market players, which support arguments of the difference in market perceptions towards CSR.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.33 no.1
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• pp.9-26
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• 1997

Stokes drift(SD) and Lagrangian discharge(LD) are important factors for analysis of flushing time, tidal exchange, solute transport and pollutant dispersion. The factors should be calculated using the approached method to flow phenomena. The aim of this paper re-examines the previous procedures for computing the SD and LD, and is to propose the new method approached to stratified flow field in the cross-section of coastal region, e.g. Masan Bay. The intensity of velocity near the bottom boundary layer(BBL) depends on the sea-bed irregularity in the coastal estuaries. So we calculated the depth mean velocity(DMV) considering that of BBL omitted in Kjerfve's calculation method. It revealed that BBL effect resulting in application of the bay acts largely on DMV in half more among 1l stations. The new expression of SD and LD per unit width in the cross-section using the developed DMV and proposed decomposition procedure of current were derived as follow : $$Q=u_0+\frac{1}{2}H_1{U_1cos(\varphi_h-\varphi_u)+U_3cos(\varphi_h-\varphi{ud})} LD ED SD$(Q_{skim}+Q_{sk2}) The third term, $Q_{sk2}$, on the right-hand of the equation is showed newly and arise from vertical oscillatory shear. According to the results applied in 3 cross-sections including 11 stations of the bay, the volume difference between proposed and previous SD was founded to be almost 2 times more at some stations. But their mean transport volumes over all stations are 18% less than the previous SD. Among two terms of SD, the flux of second term, $Q_{skim}$, is larger than third term, $Q_{sk2}$, in the main channel of cross-section, so that $Q_{skim}$ has a strong dependence on the tidal pumping, whereas third term is larger than second in the marginal channel. It means that $Q_{sk2}$ has trapping or shear effect more than tidal pumping phenomena. Maximum range of the fluctuation in LD is 40% as compared with the previous equations, but mean range of it is showed 11% at all stations, namely, small change. It mean that two components of SD interact as compensating flow. Therefore, the computation of SD and LD depend on decomposition procedure of velocity component in obtaining the volume transport of temporal and spacial flow through channels. The calculation of SD and LD proposed here can separate the shear effect from the previous SD component, so can be applied to non-uniform flow condition of cross-section, namely, baroclinic flow field.

• Progress in Medical Physics
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• v.21 no.1
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• pp.120-125
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• 2010

For the measurements of an absorbed dose using the standard dosimetry based on an absorbed dose to water the variety of factors, whether big, small, or tiny, may influence the accuracy of dosimetry. The beam quality correction factor ${\kappa}_{Q,Q_0}$ of an ionization chamber might also be one of them. The cylindrical type of ionization chamber, the PTW30013 chamber, was chosen for this work and 9 chambers of the same type were collected from several institutes where the chamber types are used for the reference dosimetry. They were calibrated from the domestic Secondary Standard Dosimetry Laboratory with the same electrometer and cable. These calibrated chambers were used to measure absorbed doses to water in the reference condition for the photon beam of 6 MV and 10 MV and the electron beam of 12 MeV from Siemens ONCOR. The biggest difference among chambers amounts to 2.4% for the 6 MV photon beam, 0.8% for the 10 MV photon beam, and 2.4% for the 12 MeV electron beam. The big deviation in the photon of 6 MV demonstrates that if there had been no problems with the process of measurements application of the same ${\kappa}_{Q,Q_0}$ to the chambers used in this study might have influenced the deviation in the photon 6 MV and that how important an external audit is.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.1
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• pp.1-8
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• 2009

EMMC(Entrapped Mixed Microbial Cell) process which is a kind of active cell immobilizing method was applied to treat fisheries processing wastewater biologically. Kinetic constants were calculated for organic and nitrogen removal and effect of effluent recycling on system performance was evaluated also. Yield coefficient, Y showed relatively low value compared with Y value obtained from conventional activated sludge process. It means that EMMC process can reduce amount of excess sludge significantly compared with conventional activated sludge process. Endogenous respiration coefficient $k_e$ of EMMC process also showed relatively low value compared with that of conventional activated sludge process. Yield coefficient Y, endogenous respiration coefficient $k_e$ and half saturation constant $k_s$ obtained from EMMC process in terms of nitrification were compared with reported value from literature based on suspended growth nitrification system. The value of Y obtained from this study has no difference compared with values obtained from literature review and $k_e$ of this study was low but $k_s$ of this study was high compared than values obtained from suspended growth nitrification system. To evaluate the effect of internal recycling on system performance, system was operated with internal recycling ratio of 1.5Q, 2.0Q, 2.5Q and 3.0Q. increase of internal recycling ratio effect more greatly on improvement of denitrification efficiency than that of nitrification efficiency. Accordingly, optimization of internal recycling ratio has to be based on improvement of anoxic reactor performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.601-610
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• 2021

The tidal current patterns at Keum River Estuary before and after the construction of coastal structures were compared according to the CASES. The depth-integrated and tidal difference treatment applied FLOW2DH numerical model was used for the tidal current predictions. The test conditions consisted of before construction of coastal structures (CASE1), after construction of coastal structures (CASE2), and the addition of watergate operation(CASE1Q and CASE2Q), and present (CASE3). CASE1 showed a stable tidal current pattern, such as a natural estuary. In CASE2, the tidal current velocities and directions of the Keum River Estuary were changed due to the installed coastal structures. In particular, the tidal current velocities of the Gaeya open channel sections (P5~P9) in CASE2 were calculated to be 10~30% larger than that of CASE1. In the case of the Gunsan Inner Harbor (P4), which is closest to the Geum River Estuary, the ebb flow rate was approximately 250~300% faster than that of other CASEs due to the discharge of the watergate operation for 2.7 hours during the ebb of CASE1Q and CASE2Q. This will affect sediment transport, and it is predicted to lead to seabed changes. CASE3 is considered to be entering the stabilization stage according to the simulation of the tidal current velocities and directions of the Keum River Estuary and the surrounding coastal area.

• Korean Journal of Breeding Science
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• v.43 no.4
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• pp.304-310
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• 2011

In previous studies, we reported QTLs for grain weight (GW), qGW3 and for spikelets per panicle (SPP), qSPP3 linked to RM60 on chromosome 3 using advanced backcross lines derived from a cross between Oryza sativa ssp. Indica cv. Milyang 23 and O. glaberrima. The O. glaberrima alleles at this locus increased GW and spikelets per panicle in the Milyang 23 background. To further confirm and narrow down the position of the QTLs on chromosome 3, substitution mapping was performed using five lines containing the target O. glaberrima segment on chromosome 3. The size and position of the O. glaberrima segment on chromosome 3 were different in each line. These lines possessed 3-10 non-target O. glaberrima introgressions in the Milyang 23 background. These five lines were evaluated for seven agronomic traits including 1,000 grain weight and spikelets per panicle and also genotyped with seven SSR markers. Four lines were informative in delimiting the position of QTLs, qGW3 and qSPP3. Two lines with the O. glaberrima segment flanked by SSR markers, RM60 and RM523 displayed significantly higher values than Milyang 23 in GW and SPP whereas two lines without that O. glaberrima segment displayed no difference in GW and SPP compared to Milyang 23. The result indicates that two QTL, qGW3 and qSPP3 are located in the interval between RM60 and RM523 which are 1.2-Mb apart. Introgression lines having QTLs, qGW3 and qSPP3 would be useful materials not only to indentify the relationship between these two yield QTLs, but also to develop high yielding variety via marker-aided selection technology.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.223-231
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• 2022

Covid-19, which has made a huge difference in our daily lives, has also brought major changes to our college education. As the class was changed from the traditional face-to-face class to a non face-to-face class, both teachers and students had difficulties in adapting, and problems such as the occurrence of academic achievement gaps due to non face-to-face classes were also raised. Therefore, this study aims to find out what attitudes students have toward non-face-to-face classes at universities caused by Covid-19. Accordingly, this study tried to identify the types of subjective perceptions college students have toward non-face-to-face classes by applying the Q methodology, and to suggest points for reference in the development and improvement of non-face-to-face classes in the future. Five types were found as a result of analysis using 30 P samples and 34 Q samples. First, learning efficiency-oriented type, second, class participation and communication-oriented type, third, non-face-to-face class active acceptance and utilization type, fourth, dissatisfaction type due to remote system and equipment operation errors, fifth, passive response type according to the situation to be. From the results of this study, it seems that it is necessary to develop an educational method for effective non-face-to-face class considering the characteristics of each type, and the merits of non-face-to-face classes, especially recorded lectures, in terms of learning efficiency, are evident. Therefore, even if face-to-face classes are conducted entirely at universities, it is believed that providing video-recorded lectures in class will be of great help to students' learning.