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        검색결과 1,407

        264.
        2020.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this work, α-Fe2O3 nanocrystals are synthesized by co-precipitation method and used as adsorbent to remove Cr6+, Cd2+, and Pb2+ from wastewater at room temperature. The prepared sample is evaluated by XRD, BET surface area, and FESEM for structural and morphological characteristics. XRD patterns confirm the formation of a pure hematite structure of average particle size of ~ 40 nm, which is further supported by the FESEM images of the nanocrystals. The nanocrystals are found to have BET specific surface area of ~ 39.18 m2 g−1. Adsorption experiments are carried out for the different values of pH of the solutions, contact time, and initial concentration of metal ions. High efficiency Cr6+, Cd2+, and Pb2+ removal occur at pH 3, 7, and 5.5, respectively. Equilibrium study reveals that the heavy metal ion adsorption of the α-Fe2O3 nanocrystals followed Langmuir and Freundlich isotherm models. The Cr6+, Cd2+, and Pb2+ adsorption equilibrium data are best fitted to the Langmuir model. The maximum adsorption capacities of α-Fe2O3 nanocrystals related to Cr6+, Cd2+, and Pb2+ are found to be 15.15, 11.63, and 20 mg g−1, respectively. These results clearly suggest that the synthesized α-Fe2O3 nanocrystals can be considered as potential nano-adsorbents for future environmental and health related applications.
        4,000원
        265.
        2020.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Thermal decomposition of the uranyl phosphate mineral phase meta-ankoleite (KUO2PO4·3H2O) has been considered in relation to high temperature thermal sintering for the immobilisation of a uranyl phosphate containing waste. Meta-ankoleite thermal decomposition was studied across the temperature range 25 – 1200℃ under an inert N2 atmosphere at 1 atm. It is shown that the meta-ankoleite mineral phase undergoes a double de-hydration event at 56.90 and 125.85℃. Subsequently, synthetically produced pure meta-ankoleite remains stable until at least 1150℃ exhibiting no apparent phase changes. In contrast, when present in a mixed waste the meta-ankoleite phase is not identifiable after thermal treatment indicating incorporation within the bulk waste either as an amorphous phase and/or as uranium oxide. Visual inspection of the waste post thermal treatment showed evidence of self-sintering owing to the presence of glass former materials, namely, silica (SiO2) and antimony(V) oxide (Sb2O5). Therefore, incorporation of the uranium phase into the waste as part of waste sentencing and immobilisation via high temperature sintering for the purpose of long-term disposal is deemed feasible.
        4,000원
        266.
        2020.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to present the differentiating factors of B2B salesperson competency through comparing the suppliers and buyers in Korean steel industry in their perception on the importance and priority of B2B salesperson competency. Based on previous studies, analysis on B2B salesperson competency has been analyzed using the B2B salesperson performance competency measure factors and appropriately reorganizing them for better application to the steel industry. The required performance competencies of B2B salesperson can be categorized into 3 different types, namely social exchange competency, advisory sales competency, and skill & knowledge competency. AHP analysis was performed for analyzing the relative importance of B2B salesperson competency based on the factors of previous studies, in which categorization of the aforementioned types had been done. As the result, first, it has been confirmed that there is a difference in 1st layer main factors between the supplier group and buyer group. The supplier group valued the advisory sales competency, while the buyer group valued skill & knowledge competency. Second, it has been proved that there is same result of relative importance in 2nd detailed factors between the supplier group and buyer group. Both group confirmed that customer member, identify customer needs and communication skill are very important factors. Third, as the result of analysis on the gap between B2B salesperson competency of the suppliers and buyers, the gap in the product knowledge and sales team member need improvement for buyer’s satisfaction according to overall results of relative importance and priority. The steel supplier was able to develop B2B salesperson competency according to the buyers’ needs based on the result of this study, and furthermore it is expected that this study will be able to contribute to increase in buyer competitiveness through differentiation in B2B salesperson competency.
        4,500원
        267.
        2020.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of the present study was to determine the best model to describe and quantify the changes in live body weight, height at withers, height at rump, body length and chest girth of Holstein cows raised under Korean feeding conditions for 50 months. The five standard growth models namely polynomial linear regression models, regression of growth variables on the first and second-order of ages in days (model 1) and regression of growth variables on age covariates from first to the third-order (model 2) as well as non-linear models were fitted and evaluated for representing growth pattern of Holstein cows raised in Korean feeding circumstances. Nonlinear models fitted were three exponential growth curve models; Brody, Gompertz, and von Bertalanffy functional models. For this purpose, a total of 22 Holstein cows raised in Korea used in the period from April 2016 to May 2020. Each model fitted to monthly growth curve records of dairy cows by using PROC NLIN procedure in SAS program. On the basis of the results, nonlinear models showed the lower root mean square of error (RMSE) for live body weight, height at withers, height at rump, body length and chest girth (12.22, 1.95, 1.55, 4.04, 2.06) with higher correlation coefficiency (R2) values for live body weight, height at withers, height at rump, body length and chest girth (0.99, 0.99, 0.99, 1.00, 1.00). Overall, the evaluation of the different growth models indicated that the Gompertz model used in the study seemed to be the most appropriate one for standard growth of Holstein cows raised under Korean feeding system.
        4,000원
        268.
        2020.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, through an AHP (Analytic Hierarchy Process) analysis, the internal construction project was designed to analyze the factors affecting the performance of the project and provide suggestions on the quality of communication. To carry out this study, a selection factor was selected by referring to AHP theory and existing prior research. AHP technique was used to collect weights after analysis, examine and analyze gaps. In the interior construction project, the most important factor among the factors influencing the quality of communication to the project performance was communication interaction. Among the sub-factors, accuracy of exchange of information and timeliness of communication were shown in the order of importance. Looking at the results of comprehensive analysis of the first and second layers, the accuracy of information exchange among the elements of communication quality was found to be the number 1 in weight. The timeliness of communication, which is ranked second, and communication that takes place at an appropriate time can lead to efficiency in shortening the project execution period by eliminating unnecessary work. And, Among the factors that affect communication quality, it was analyzed that communication method is not an important factor when compared to other factors. This study shows that quality of communication influences the performance of interior construction projects and provides suggestions for improving communication quality. And it has been confirmed that managing communication quality can act as an important issue that can improve business performance in project execution and production of results.
        4,200원
        269.
        2020.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted at the National Institute of Animal Science from 2010 to 2017. As a variety that is sufficiently productive in the southern regions to replace imported varieties and sufficiently cold-resistant to be cultivated in the central-northern regions, "IR605" was developed and submitted to the Korea Seed & Variety Service in an application for protection. The novel Italian ryegrass variety "IR605" is a diploid with green leaves, a semi-erect growth habit before wintering, and an erect growth habit in the spring. "IR605" was a medium maturing variety with a heading date of around May 15th. "IR605" had a flag leaf width of 9.9 mm, flag leaf length of 26.7 cm, and plant length on the heading date of 100 cm, which was approximately 5 cm longer than "Kowinearly." The stem thickness and ear length of "IR605" are 0.08 mm thicker and 0.5 cm longer than those of "Kowinearly", respectively. The cold-resistance of "IR605" was weaker than that of "Kowinearly", but strong enough to be cultivated in Pyeongchang, Gangwon province. The dry matter yield of "IR605" (9,308 kg/hectare) was 20% higher than that of "Kowinearly", which was further pronounced in the southern region of Haenam, where there was a 52% increased (p < 0.05). The in vitro dry matter digestibility of "IR605" was 68.4% at which was slightly higher than that of "Kowinearly", The total digestible nutrients was 58.5%, which was slightly lower than "Kowinearly". Overall, the feed quality characteristics of "IR605" were similar to those of "Kowinearly".
        4,000원
        270.
        2020.09 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Melia azedarach is commonly used in traditional and folk medicine in Korea and China to treat a variety of diseases including diarrheal, diabetic, rheumatic, and hypertensive disease. The aim of this study was to determine the potential prophylactic and therapeutic effects of Melia azedarach against a broad spectrum of viruses in in vitro cell culture model and the protective effect against different influenza A subtypes in BALB/c mice model. An effective dose of pre-treatment, co-treatment, and post-treatment of Melia azedarach significantly reduced the replication of coxsackievirus, herpes simplex virus, influenza A virus, enterovirus, and bovine rhinovirus in both epithelial and macrophage cell lines. Melia azedarach treatment remarkably promoted the phosphorylation of the key molecules associated with the type-1 interferon and NF-κB signaling pathways. Furthermore, it induced the secretion of type-1 interferon and pro-inflammatory cytokines and the subsequent stimulation of the antiviral state in both epithelial and macrophage cells. Interestingly, oral inoculation of an effective dose of herb extract significantly improved viral clearance in the lungs of BALB/c mice, thus exhibiting protection against several subtypes of influenza A virus. Together with our results indicate that an extracts of Melia azedarach and its components could exhibit a potential natural source of an antiviral drug candidate for a broad spectrum of viruses in animal and humans.
        4,300원