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        검색결과 869

        1.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the event of an emergency such as facility shutdown during process operation, the by-product gas must be urgently discharged to the vent stack to prevent leakage, fire, and explosion. At this time, the explosion drop value of the released by-product gas is calculated using ISO 10156 formula, which is 27.7 vol%. Therefore, it does not correspond to flammable gas because it is less than 13% of the explosion drop value, which is the standard for flammable gas defined by the Occupational Safety and Health Act, and since the explosion drop value is high, it can be seen that the risk of fire explosion is low even if it is discharged urgently with the vent stock. As a result of calculating the range of explosion hazard sites for hydrogen gas discharged to the Bent Stack according to KS C IEC 60079-10-1, 23 meters were calculated. Since hydrogen is lighter than air, electromechanical devices should not be installed within 23 meters of the upper portion of the Bent Stack, and if it is not possible, an explosion-proof electromechanical device suitable for type 1 of dangerous place should be installed. In addition, the height of the stack should be at least 5 meters so that the diffusion of by-product gas is facilitated in case of emergency discharge, and it should be installed so that there are no obstacles around it.
        4,000원
        2.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to prepare rice straw silage using cabbage by-product and persimmon peel which are agricultural by-products produced during the same season in Korea. The treatments comprised a commercial corn silage as the control and four rice straw silages (P15-1, P15-2, P30-1, and P30-2) with different levels of persimmon peel supplementation (15%, 30%) and ensiled periods (1 or 2 months). The cabbage by-products were used to adjust silage moisture (approximately 65%). The quality of the experimental silages was evaluated based on organic acid content, palatability to three Holstein dairy cows, and manufacturing cost. In the corn silage, all chemical compositions, except total digestible nutrients and levels of lactic and butyric acids, were significantly (p<0.05) higher than those of the rice straw silages. However, considering the quality analysis using Flieg's score, the rice straw silage supplemented with 30% persimmon peel ensiled for 2 months (P30-2) was estimated as second grade to corn silage, and was relatively better in palatability to dairy cows than the other rice straw silages, which were considered third grade. The manufacturing cost of rice straw silages using cabbage by-product and persimmon peel compared to that of corn silage was reduced by 28%. Consequently, to prepare rice straw silage adjusted to 65% moisture using only cabbage by-products without inoculant, 30% of persimmon peel, 10% of ground corn, and 2% of molasses as a sugar source should be ensiled for at least 2 months.
        4,000원
        6.
        2023.11 구독 인증기관·개인회원 무료
        Molten Salt Reactor, which employs molten salt mixture as fuel, has many advantages in reactor size and operation compared to conventional nuclear reactor. In developing Molten Salt Reactor, the behavior of fission product in operation should be preliminary evaluated for the correct design of reactor and its associated system including off-gas treatment. In this study, for 100 Mw 46 KCl- 54 UCl3 based Molten Salt Reactor with operating life time of 20 year, the fission product behavior was estimated by thermodynamic modeling employing FactSage 8.2. Total inventory of all fission product were firstly calculated using OpenMC code allowing depletion during neutronic calculation. Then, among all inventory, 46 element species from Uranium to Holmium were chosen and given to the input for equilibrium module of Factsage with its mass. In phase equilibrium calculation, for the correct description of solution phase, KCl-UCl3 solution database based on modified quasichemical model in the quadruplet approximation (ANL/CFCT-21/04) was employed and the coexisting solid phase was assumed to pure state. With the assumption of no oxygen and moisture ingress into reactor system, equilibrium calculation showed that 1% of solid phase and of gas phase were newly formed and, in gas phase, major species were identified : ZrCl4 (47%), Xe (33%), UCl4 (14%), Kr (5%), Ar (1%) and others. This result reveals that off-gas treatment of system should account for the appropriate treatment of ZrCl4 and UCl4 besides treatment of noble gas such as Xe and Kr.
        7.
        2023.11 구독 인증기관·개인회원 무료
        Radiation from spent nuclear fuel (SNF) is one of key factors affecting the dissolution process of SNF and the source term from repository. The dissolution rate of uranium dioxide (UO2) matrix of SNF is expected to control the release of radionuclides from SNF in contact with water under geological disposal conditions. Based on the oxidative dissolution mechanism, the solubility of UO2 can increase significantly if the reducing environment near the fuel surface is altered by water radiolysis caused by radiation from SNF. Therefore, the analysis of water radiolysis products such as radicals (·OH, ·OH2, eaq, ·H) and molecules (H3O+, H2, H2O2) is perquisite for studies on the rate of such dissolution process to determine oxidation/dissolution mechanism and related rate constants. In this study we examined the two-known spectroscopic methods developed for H2O2 determination; one is the luminol-based chemiluminescence (luminol-CL) method and the other is the spectrophotometry using ferrous oxidation-xylenol orange complexation (FOX). Their applicability for quantitative analysis of H2O2 in potential aqueous samples from SNF dissolution studies was evaluated in terms of the analytical dynamic range (ADR), the limit of detection (LOD) and the interfering effects of various metal ions possibly present in real samples. The luminol-CL method exploits the chemiluminescence reaction caused by luminol; when in the presence of a metallic catalyst (e.g., Cu2+, Co2+), luminol emits a blue light (425 nm) at pH 10- 11 in response to oxidizing agents such as hydrogen peroxide. Although a flow-through reaction system is routinely employed to enhance the analytical sensitivity we achieved the ADR up to ~200 μM and LOD < 1 μM by a batch-wise CL detection using conventional cuvette cells and an intensified charge-coupled device (ICCD). Interestingly, it turned out that the interfering effects of other metal ions (e.g., UO2 2+, U4+, Fe2+ and Fe3+) is minimal, which should be advantageous for the luminol-CL method to be employed for samples potentially containing other metal ions. On the other hand, the FOX method spectrophotometrically analyzes H2O2 based on the difference in color (or absorption spectra) of Fe-xylenol orange (XO) complexes. Initially, the Fe2+-XO complex was provided in working solutions at pH 3, which was subsequently mixed with samples having H2O2 and allowed for quantitative oxidation of Fe2+ to Fe3+. Typically, by monitoring the absorbance of Fe3+-XO complex at 560-580 nm (λmax) the ADR up to ~100 μM and LOD ~1.6 μM were achieved. However, it is found that interfering effects from M3+ and M4+ ions are significant; these interfering metal ions can form XO complexes so as to directly contribute the measured absorbance. In contrast, the influence from M2+ ions was found to be negligible. To summarize we conclude that both methods can be applied for H2O2 determination for aqueous samples taken from SNF dissolution tests. However, prior to applying the FOX method the metal ion composition in those samples should be thoroughly identified not to overestimate the H2O2 concentration of samples. More details of underlying chemical reactions in both methods will be discussed in the presentation.
        8.
        2023.11 구독 인증기관·개인회원 무료
        Nuclear power plants in Korea stores approximately 3,800 drums of paraffin solidification products. Due to the lack of homogeneity, these solidification products are not allowed to be disposed of. There is therefore a need for the separation of paraffin from the solidification products. This work developed an equipment for a selective separation of paraffin from the solidification product using the vacuum evaporation and condensational recovery method in a closed system. The equipment mainly consists of a vacuum evaporator and a condensational deposition recovery chamber. Nonisothermal vacuum TGAs, kinetic analyses and kinetic predictions were conducted to set appropriate operation conditions. Its basic operability under the established conditions was first confirmed using pure paraffin solid. Simulated paraffin solidification product fixing dried boric acid waste including nonradioactive Co and Cs were then fabricated and tested for the capability of selective separation of paraffin from the simulated waste. Paraffin was selectively separated without entertainment of Co and Cs. It was confirmed that the developed equipment could separate and recover paraffin in the form of nonradioactive waste.
        9.
        2023.11 구독 인증기관·개인회원 무료
        Copper, mainly used as a material for outer canister, generates various corrosion products under aerobic and anaerobic conditions in the operational and/or post-closure phases of the deep geological repository. These products could affect performance of engineering barrier system (EBS) through interaction with surrounding bentonite that makes up the buffer and backfill materials. Accordingly, in this study, we suggested research items to be conducted to minimize degradation of EBS due to copper corrosion products, based on the phenomenological review results for copper corrosion mechanisms and interaction between resultant product and bentonite in the deep geological disposal environment. During the post-closure phase, condition in the disposal facility changes form aerobic to anaerobic over time, and thereby, causes and products of copper corrosion vary. Under aerobic condition, copper corrosion is mainly induced by oxygen (O2) in the repository, chloride (Cl-) and carbonate (CO3 2-) ions from groundwater flowing into the facility, resulting in corrosion products such as cuprite (Cu2O), tenorite (CuO), atacamite (CuCl2·3Cu(OH)2) and malachite (Cu2CO3(OH)2). And, copper corrosion under anaerobic condition is primarily due to hydrogen sulfide (H2S) and sulfate (SO4 2-) in groundwater flowing into the facility, leading to formation of chalcocite (Cu2S) and covellite (CuS) as corrosion products. Depending on environment of the disposal facility, copper corrosion products are dissolved and ionized to Cu2+ in groundwater, and subsequently adsorbed on the nearby smectite. Then, it causes a cation exchange reaction with exchangeable cations in the interlayer of smectite. As a result of reviewing the previous experiments, it was confirmed that Cu2+-exchanged bentonite has a slightly reduced basal spacing and swelling capacity. From the results as above, there is a possibility that performance of EBS may be degraded due to copper corrosion products. To minimize its effect of degradation in the domestic facility, items to be further studied are as follows: (a) Method for reducing copper corrosion such as selection of appropriate material and structure for the canister, and (b) How to control dissolution of copper canister product into groundwater through predicting type and ionization process. The results of this study could be directly used to developing design concept of EBS for the domestic disposal facility and to establishing roadmap of future R&D programs.
        10.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the context of the 4th Industrial Revolution, the rise of electric vehicles and personal mobility is evident. However, regulatory authorities seem to overlook vast opportunities, placing two-wheelers in a deregulated category and focusing mainly on regulations. This paper addresses a notable trend in e-mobility, emphasizing aspects often overlooked in traditional motorcycle regulatory research. Using the industrial life cycle theory as a basis, we identify challenges that have affected traditional combustion-engine two-wheelers and offer insights to navigate similar obstacles in the future. Consequently, the domestic two-wheeler market experienced a brief surge but lacked sustainable growth prospects. However, considering Japan's success in establishing global standards and design dominance in the two-wheeler industry despite its late entry, there appears to be potential for a rebound in the domestic market.
        4,000원
        11.
        2023.10 구독 인증기관·개인회원 무료
        최근 몇 년 전부터 우리나라의 양봉농가에는 전에 경험하지 못했던 이상기후 악재와 초비극 상황인 꿀벌 군집 붕괴현상(Colony collapse disorder, CCD)으로 인하여 최대 60% 이상의 꿀벌이 폐사하거나 사라지는 등 양봉산업 의 막대한 손실을 초래하였다. 본 연구는 복잡하고 다양한 원인으로 약해진 꿀벌의 면역력과 봉군 세력을 향상시 키기 위하여 농업부산물 홍삼박을 활용한 화분떡을 자가제조하여 꿀벌 사양 먹이를 통한 봉군 세력에 어떠한 영향을 미치는지를 구명하고자 수행하였다. 가공부산물 홍삼박을 건조하여 130 mesh 이상 초미립자로 분쇄하 였으며, 조사포닌 725 mg 100-1을 함유하였고 화분떡 총중량의 0.5, 1.0, 2.5, 5.0, 10.0%로 첨가하여 완전하게 혼합 배합하여 화분떡을 제조하였다. 분봉벌은 4월 분봉한 봉군으로 이용하였으며, 2달 동안 1주일 간격으로 대조구 화분떡과 제조한 홍삼박 화분떡 5처리구에 급이하여 봉군의 세력을 조사하였다. 사양 먹이로 급이한 화분떡은 30일간 달관조사에서 대조구와 처리구 모두 꿀벌 먹이로 거부반응은 없었다. 봉군 세력 조사로 4월 분봉벌의 봉군은 1매 2갈로 시작하여 약 한 달 후에 6매 봉판으로 증소되었으며, 이때 조사된 봉군별 봉개율은 대조구 55%(100 기준) 대비 홍삼박 0.5~1.0% 처리구는 58~60%로 +(5~9)% 향상되었던 반면, 홍삼박 2.5% 이상 첨가한 처리구에서는 봉개율이 -(9~20)% 감소하는 경향을 보였다. 그리고 화분떡 먹이 소모량을 조사한 결과, 대조구 평균 96.9%(100) 소모율 대비 홍삼박 0.5% 처리구는 97.7%로 다소 높았으나 홍삼박 2.5% 이상 처리구에서는 점점 감소하는 경향을 보였다.
        12.
        2023.10 구독 인증기관·개인회원 무료
        Phosphine is a common pesticide used to control grain pests in Rice Processing Complex(RPC). However, increasing use of aluminum phosphide caused the occurrence of phosphine resistance pests. In this study, phosphine resistance pests collected at RPC in 2023 was investigated with FAO No. 16 test, Dihydrolipomaide dehydrogenase(DLD) test and amino acid mutation analysis to identify the occurrence of phosphine resistance in Korea. Tested pests were collected in the 7 province 35 region. As a result of the FAO test of 21 regions, all sample were phosphine sensitives. In DLD test and amino acid analysis, 7 region samples were weak resistances. It is required to inspect the RPC and other grain storage continuously to inhibit the widespread of resistant pest.
        13.
        2023.10 구독 인증기관·개인회원 무료
        Historically, the control of stored-product insects has mostly relied on the use of fumigants such as methyl bromide (MB) and phosphine. However, methyl bromide is no longer used for structural fumigations, and phosphine insecticide resistance is rising globally. Methyl benzoate (MBe) is a new green pesticide that occurs naturally as a metabolite in plants. In this study, we evaluated the the potential use of MBe as a fumigant against a variety of stored-product insects. According to our laboratory findings, MBe showed strong fumigation toxicity against the Indian meal moth and flat grain beetle with an LC50 value of 0.1 μL/L and 0.76 μL/1.5 L air, respectively, compared to the other tested insects. Furthermore, no significant differences were observed in susceptibility levels between the lab strain and the phosphine-resistant lesser grain borer and rice weevil. However, the red flour beetle had the highest LC50 value of 8.26 μL/1.5 L air. Overall, MBe seems to be a highly promising candidate for the development of environmentally-friendly alternative fumigants.
        14.
        2023.07 구독 인증기관·개인회원 무료
        Previous research on green product innovation (GPI) has primarily focused on the performance of new product development, neglecting the critical, early fuzzy front-end (FFE) phase. Drawing upon the firm's resource-based view (RBV) and dynamic capabilities perspective, this study explores how co-production affects FFE outcomes (creative idea and product definition proficiency) of GPI and whether joint learning ambidexterity is a mediating mechanism in international buyer-supplier relationships. Additionally, we provide a contingency perspective by considering the moderating role of the innovation ecosystem on the relationship between co-production and joint learning ambidexterity. Finally, this study contributes to a theoretical understanding, analyzing co-production as a predictor, joint learning ambidexterity as a mediator, and innovation ecosystem as a moderator.
        15.
        2023.07 구독 인증기관·개인회원 무료
        Using a tablet (versus a mouse) when shopping online has been shown to increase a shopper’s overall preference. Three studies demonstrate that this effect is robust across various contexts. We hypothesize that consumers will like the products they explore on touch devices (e.g., tablets) because they can more easily imagine using the products (Shen et al., 2016). When given the opportunity to explore the items on the touch devices, even utilitarian products and that this effect will be robust across different contexts.
        16.
        2023.07 구독 인증기관·개인회원 무료
        The popularity of the Korean entertainment industry has been growing worldwide. Various forms of media, such as movies, TV series, music, radio and many more, have been used as a platform to launch and promote new products of many brands. For instance, Laneige – a Korean cosmetic company was successfully placed in the Korean drama – Descendants of the Sun. Previous studies have accounted for various factors in analysing product placement in movies, such as brand familiarity, brand fit, and movie genre. However, the effect of the emotional context of where the product is placed remains unclear. The purpose of the present research is to investigate whether the effectiveness of product placement is influenced by the emotions depicted in the scene, and whether the ethicality of the product matters.
        17.
        2023.07 구독 인증기관·개인회원 무료
        Although influencers establish their reputation and gain popularity by demonstrating expertise toward a specific topic, there is a huge potential to extend their market by tapping into different topics. Specifically, by promoting different types of product categories. However, previous studies tend to have different predictions about the success of this practice. Such that, according to the match-up hypothesis, it is unlikely that the influencer can successfully promote different product categories. On the other hand, Stereotype Content Model (SCM) suggests that influencers might be perceived as competence that overgeneralized to other domains. By conducting a survey to 302 online consumers in Indonesia, this study aims to test two competing routes toward influencer’s success in promoting product categories other than their initial expertise within the fashion context. The findings of this study revealed the primacy of match-up hypotheses, even when the influencers are perceived as competent, it does not mean that consumers are willing to follow their recommendation if it is outside their expertise domain. Only when there is an influencer-product fit, consumers are willing to accept their recommendation. However, perceived competence of the influencers can promote acceptance to follow recommendation on different product categories only when it established trust on the influencer.
        18.
        2023.07 구독 인증기관 무료, 개인회원 유료
        This study investigated the impact of sustainable perceived value (SPV) on fashion consumers. The results revealed that SPV significantly affects customer satisfaction, loyalty, and the positive relationship between satisfaction and loyalty were confirmed, implicating SPV as a valid approach in measuring consumption value of sustainable fashion products.
        4,000원
        19.
        2023.07 구독 인증기관·개인회원 무료
        We investigate the incremental predictive power of three consumer dispositions – xenocentrism, cosmopolitanism and ethnocentrism – on domestic and foreign product purchase intentions, after taking the impact of consumer demographics and product category-specific variables into account. Using data from an online survey of 201 Turkish consumers, hierarchical regression analysis reveals that widely used demographic variables (namely, age, gender and education) do not significantly influence consumer intentions to buy either domestic or foreign clothing products. Of the consumer dispositions, xenocentrism exerts a significant negative effect on domestic product purchase intentions, cosmopolitanism has a positive effect on foreign product purchase intentions, while ethnocentrism shows no effect on either domestic or foreign product purchase intentions. Implications of the findings are considered and future research directions identified.
        20.
        2023.07 구독 인증기관·개인회원 무료
        Firms are increasingly using social media influencers to promote their products. We develop a two-period model to investigate a firm’s strategy for introducing a product via an influencer, where there is uncertainty in the influencer-product match. In the second period, the influencer exerts an effort to promote the product to her followers, who can spread the product information to non-followers via word-of-mouth (WOM). In the second period, the firm sells to the non-followers. We show that the firm’s pricing, production, and commission contract decisions depend on the influencer’s incentive-independent excess payoff from the promotion and on the difference between the WOM effect of followers who do or do not make a purchase rather than the WOM effect of each group. As the influencer’s incentive-independent payoff increase, the firm will increase (decrease) commissison rate and commission rate when the followers’ sensitivity to product price is relatively low (high) compared with that to the influencer’s effort. As the marginal WOM benefit of the first-period sales increases, the firm tends to reduce his unit net profit from sales. The influencer with a medium-sized follower base receives the highest commission rate and exerts the largest promotion effort. While the followers of influencers with a medium-sized follower base may pay the highest price. We also show that (i) there exists a threshold for the probability of match, above which the firm faces zero demand in the first period if an influencer-product mismatch occurs; and (ii) the firm may charge followers a lower price than non-followers, even though followers are less sensitive to price than non-followers. Finally, regarding influencer selection, we find that the firm may not be better off employing an influencer with a larger follower base.
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