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        검색결과 200

        3.
        2024.04 구독 인증기관·개인회원 무료
        산업혁명 이후 화석연료 사용의 급격한 증가와 온실가스 배출이 심해져 온난화 경향이 심각해 탄소 배출을 절감하는 상황이 요구되고 있다. 본 연구는 탄소 격리 효과를 가지고 있는 바이오차와 콘크리 트의 취성을 극복하고 연성을 증가시켜 균열의 발생을 최소화하여 내구성을 향상 시킬 수 있는 PVA (Polyvinyl Acohol)섬유를 활용하여 기존의 콘크리트의 단점을 보완하고, 시멘트 저감 효과와 친환경 성을 갖춘 고연성 섬유보강 시멘트 복합체(ECC)를 제작하여 바이오차 시멘트 대체 비율에 따른 ECC 의 역학적 특성을 분석하고 비교하였다. 바이오차 시멘트 대체 비율 5%를 최대치로 설정하여 시멘트 대체 비율을 1%씩 올려 0%, 1%, 2%, 3%, 4%, 5%까지 설정하여 플로우 시험, 압축강도 실험, 쪼갬 인장 강도 실험, 휨 강도 실험을 진행하였다. 모르타르의 유동성을 평가하기 위해 플로우 시험을 실시 했으나, 바이오차 시멘트 대체 비율에 관계없이 플로우는 큰 차이를 보이지 않았다. 바이오차 시멘트 대체 비율에 따른 강도 비교를 위한 압축강도 실험, 쪼갬 인장 실험에서는 바이오차 시멘트 대체 비율 2%가 가장 높은 값을 보였다. 휨 강도 실험에서는 바이오차 시멘트 대체 비율 3%가 가장 큰 값을 보 였다. 휨 강도 실험에서는 바이오차를 혼입하지 않은 노말 ECC와 비교했을 때 바이오차의 시멘트 대 체율이 높아질수록 강도가 감소하였지만, 압축강도와 쪼갬 인장강도 실험에서는 대체율이 높아지면 강 도가 증가하는 경향이 나타났다.
        4.
        2024.03 구독 인증기관·개인회원 무료
        This study addresses the environmental impact associated with waste management and natural aggregate production. It explores the potential of utilizing Coal Bottom Ash (CBA) and Reclaimed Asphalt Pavement Aggregate (RAPA) as complete replacements, respectively, for fine and coarse aggregates in concrete. Despite their similarities to natural aggregates, CBA and RAPA often end up in landfills. Laboratory tests were conducted, revealing satisfactory performance in drying shrinkage and air void parameters. However, while the flexural strength met design requirements, the compressive and splitting tensile strengths were lower than predicted. The deviation in strength development behavior from natural aggregate concrete (NAC) was attributed to weak agglomerated aggregates in RAPA and the large size of the interfacial transition zone (ITZ) due to the old asphalt coating surrounding RAPA. To enhance the strength behavior, two methods were employed: compaction in the form of roller-compacted concrete and RAPA abrasion carried out by rolling RAPA in a concrete mixer. Compaction improved aggregate interlock, while RAPA abrasion decreased agglomerated aggregates and minimized asphalt coating, reducing ITZ size. These treatments resulted in improvements in compressive, flexural, and splitting tensile strengths, with the combination of both treatments having the most significant effect. Analysis of relationships between flexural, splitting tensile, and compressive strengths indicated that CBA and RAPA concrete behaved more similarly to NAC after the treatments. This research suggests that with appropriate interventions, it is feasible to utilize CBA and RAPA in concrete, contributing to sustainable construction through improved waste management, carbon footprint reduction, and conservation of natural resources.
        5.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        세계적으로 환경에 대한 관심이 커지면서, 탄소 저감 및 탄소 중립을 위한 다양한 연구들이 진행되고 있다. 특히 최 근에는 탄소 포집 및 저장 기술인 CCS(Carbon Capture and Storage)에 주목이 높아졌다. 그뿐만 아니라, 대기 중의 탄소를 효과 적으로 저장하는 특성을 가진 바이오차는 탄소 중립에 기여할 수 있는 방안으로 다양한 연구가 진행되고 있다. 건설 산업에서 는 시멘트 대체재를 활용한 탄소 감소 관련 연구가 진행 중이며, 본 연구에서는 바이오차를 콘크리트 및 모르타르의 시멘트 대 체재로 활용하여 시멘트 사용량을 줄이고, 동시에 콘크리트 및 모르타르 내의 탄소를 포집하고 저장하여 탄소 배출량을 감소시 키고자 한다. 이를 위해 바이오차의 시멘트 치환율을 0%, 10%, 20%로 설정하고, 각각의 경우에 대해 콘크리트 및 모르타르의 슬럼프, pH 농도, 그리고 압축강도를 비교하였다.실험 결과에 따르면, 바이오차의 시멘트 치환율이 증가함에 따라 슬럼프와 압 축강도가 감소하는 경향을 보였으며, pH는 유사한 양상을 나타냈다.
        4,000원
        6.
        2024.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this investigation, samples of the chemical (Hg1-xPbxBa2Ca1.8Mg0.2Cu3O8+δ) were prepared utilizing a solid-state reaction technique with a range of lead concentrations (x = 0.0, 0.05, 0.10, and 0.20). Specimens were pressed at 8 tons per square centimeter and then prepared at 1,138 K in the furnace. The crystalline structure and surface topography of all samples were examined using X-ray diffraction (XRD) and atomic force microscopy (AFM). X-ray diffraction results showed that all of the prepared samples had a tetragonal crystal structure. Also, the results showed that when lead was partially replaced with mercury, an increase in the lead value impacted the phase ratio, and lattice parameter values. The AFM results likewise showed excellent crystalline consistency and remarkable homogeneity during processing. The electrical resistivity was calculated as a function of temperature, and the results showed that all samples had a contagious behavior, as the resistivity decreased with decreasing temperature. The critical temperature was calculated and found to change, from 102, 96, 107, and 119 K, when increasing the lead values in the samples from 0.0 to 0.05, 0.10, and 0.20, respectively.
        4,000원
        7.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Largemouth bass (Micropterus salmoides) is introduced species that has caused aquatic ecology activity both in vitro and in vivo were investigated for the possibility of application of the bass extract as an alternative feed ingredient. Methods: The bass oil was extracted using a 1-L supercritical extractor, while the protein was extracted from 250 g of bass dry matter, which was dissolved in 1 mL of H2O at 50℃. Both oil and protein extracts were evaluated antioxidant activities and the level of DPPH radical scavenging assay and nitric oxide (NO) production assay with lipopolysaccharide response. Oral administration of 6.6 μL/g bass protein and 5.38 μL/g bass oil conducted for investigating serological and physiological effect. Results: DPPH radical scavenging showed similar radical scavenging ability of 50 μM of ascorbic acid at 200 μg of protein and 10% of oil treatment. NO concentration was diminished by the treatment of bass oil. Oral administration of both bass oil and proteins to mice showed that the body weight increase rate of the bass oil treated group was significantly reduced by 1.55 g compared to the other groups. The number of white blood cells (WBC) was increased by 4.52 k/μL in the bass protein-treated group and 4.44 k/μL in the bass oil-treated group compared to the control group. However, the serum IgG level did not show a significant difference between the bass extract-treated groups and the control group. Conclusions: These studies demonstrate that both bass oil and proteins extracted from the bass not only provide excellent effects of antioxidant and immune activity but can also be used as functional food supplements.
        4,200원
        8.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study evaluated the consumers’ demands and points of improvement for restaurant meal replacement through importance–performance analysis by the restaurant meal replacement segment market using food involvement. The results were as follows. First, after segmenting the restaurant meal replacement market using food involvement, it was classified into three markets (multiple involvements, exploration-oriented, and product quality-oriented). Second, an analysis of the importance of restaurant meal replacement selection attributes revealed taste, sanitation, quality, freshness, price, saving time, texture, ingredients, preparation process, and quantity to be highly important. An analysis of the differences according to the market type revealed the multiple involvement type to be more important than other groups, considering the restaurant meal replacement selection attribute element. Third, an analysis of the importance-performance analysis of restaurant meal replacement selection attributes revealed that quantity and price as the selection attributes that needed to be improved first in all three markets. In addition, in the multiple involvement type, food additives appeared as a selection attribute requiring priority improvement, revealing the characteristics of a market that cares about diet and health.
        4,500원
        10.
        2023.11 구독 인증기관·개인회원 무료
        Among the nuclear power plant facility improvement projects, out of a total 10 replacement reactor vessel closure head (RRVCH), five have been replaced, starting with Gori Unit 1, and five, including Hanul Unit 1, Hanbit Units 5 and 6, and Hanul Units 3 and 4 will be replaced in the future. This paper presents the method of treating Latch Housing among radioactive waste generated during the replacement of Hanul Unit 2 (February 2023). Latch Housing controls the control rod by receiving magnetic force from the CRDM’s Coil Stack. Located in the Old Reactor Vessel Head (ORVH) Hot Spot, the range of measured radiation dose rate was 0.3 to 0.8 mSv h-1 (up to 4.5 mSv h-1). The amount of radioactive waste generated was 35.8 Baler-Drum (based on 200L), and the order of treatment was to cut into the Omega Seal of the CRDM, the CRDM and Latch Housing Transfer, the boundary of the CRDM and Latch Housing, the Rod Travel Housing, the Motor Housing and the Latch Assembly, and then transfer and Drumming. In the United States, out of 93 operating reactors, 31 reactor vessel heads have been replaced and 19 reactor vessel heads are scheduled to be replaced. In Korea, 25 reactors are in operation, and two reactors have been permanently shut down. Among them, the nine old reactors for more than 30 years (as of September 2021) are expected to achieve ALARA and reduce radwaste management costs through the management method applied to replace the reactor vessel head.
        11.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper proposes a standardized vehicle body repair manual for vehicles with major damage to the rear side members caused by rear-end collisions. The manual is used to refine the vehicles. Typical work involves replacing large traffic accident modes with new members or modifying and aligning existing members. If repairs are made for various reasons, the members should be attached based on the body of a new vehicle. Unlike new vehicle members, the accident vehicle repair process depends heavily on the operator's skilled skills (i.e., the performance, purpose, level, and quality of the body replacement work due to the nature of the vehicle body replacement work). When repairing or replacing a rear side member of a body repair, three methods of operation are applied because the damage and deformation vary depending on the object of the other party, although the degree of damage varies. There is no standardized manual for side member over-hole replacement, partial replacement, or partial modification, since these repair methods vary depending on the operator's thoughts and angle of view. Therefore, customers should use standardized vehicle repair manuals to ensure that their vehicle receives the same repair when damaged. This study is expected to develop a standardized vehicle repair manual to reduce the drop in used market prices after replacement or repair of rear side members at vehicle repair plants.
        4,000원
        14.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Some patients may not fully recover their daily activity capabilities even after the total hip replacement (THR), and may continue to experience functional limitations for up to a year after the procedure, according to reports. Objectives: The purpose of this study was to examine the effects of machine squat on muscle strength, balance and gait in patients after THR. Design: A randomized controlled trial. Methods: Thirty-three patients after THR were randomly allocated into slide (n=11), reformer (n=11), and control groups (n=11). Each group underwent their respective squat regimens for thirty minutes, seven times a week, for two weeks. Muscle strength changes were assessed using the manual muscle test (MMT), balance was evaluated using the Berg Balance Scale (BBS), and gait analysis was performed using the 10-meter walk test (10MWT). Results: Significant changes in hip flexor and abductor strength were observed in the slide and reformer groups within each group (P<.05). The reformer group showed significant changes in hip extensor strength (P<.05). Significant improvements in BBS were observed in all three groups (P<.05). There were significant changes in 10MWT in the slide and reformer groups (P<.05). A significant difference in hip extensor strength was found between the reformer and control groups after the intervention (P<.0167). Significant differences in BBS were observed between the slide and reformer groups and between the reformer and control groups after the intervention (P<.0167). Conclusion: Our findings suggest that machine squat regimens can be effective for early rehabilitation after THR, improving muscle strength, balance, and gait.
        4,000원
        15.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cars serve as vehicles for the conveyance of both passengers and cargo. Inevitably, traffic accidents constitute a significant facet of vehicular operation. These accidents manifest in various forms, including frontal, rear-end, and lateral collisions. While the resultant vehicular damages may exhibit similarities, they remain inherently distinct. Owing to the intricate nature of automotive body repairs, simplistic adherence to textbook doctrines proves inadequate. The rectification of damaged vehicle bodies hinges upon the practitioner's experiential acumen. Consequently, discourse pertaining to body repair technology necessitates grounding in empirical data encompassing prevailing industry norms and attendant financial implications. Variability in individualized methodologies can engender substantial temporal and monetary outlays within the domain of automotive bodywork. Moreover, the integration of novel material technologies within vehicular structures mandates a perpetual pursuit of knowledge and empirical inquiry into the domain of vehicle body repair procedures, particularly as applied to emerging materials. Compounding this imperative is the unwavering commitment to preserving the safety paradigm from the vehicle owner's perspective, ensuring that restorative interventions subsequent to accidents do not compromise safety benchmarks.
        4,000원
        16.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Car accidents require continuous access to new technologies in the field of maintenance that cannot be achieved by textbook theory alone due to the nature of body repair without the same damage and repair conditions. In the case of vehicle repairs due to unexpected accidents, it is difficult to satisfy the needs of the vehicle owner, so in this study, it is possible to restore them to their original state with improved technology like the vehicle owner. Better maintenance technologies have been explored: complete replacement of side quarter panels, partial replacement and partial modification of side quarter panels, as well as tangible and intangible effects such as not applying depreciation rates due to traffic accidents, preventing environmental pollution and maximizing owner satisfaction.
        4,000원
        17.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to analyse factors related to Home Meal Replacement (HMR) use among university students and to determine the dietary quality according to its consumption. A survey on the consumption of HMR and Nutrition Quotient (NQ) was conducted from September to November 2021. The study included 232 university students (88 males, 144 females) from Chungcheong. The proportion of consumption at least once a week was 71.55% for ready-to-eat foods, 55.60% for ready-to-cook foods, 40.95% for fresh-cut products, and 21.12% for meal-kits. The preference ratings were as follows: ready-to-eat foods, 3.77 out of 5 points, meal-kits, 3.53 points, fresh-cut products, 3.52 points, and ready-to-cook foods, 3.45 points. In terms of satisfaction, convenience (4.06 out of 5 points), taste (3.71 points), variety (3.67 points), and food hygiene (3.62 points) were rated the highest. The scores in the moderation NQ were significantly lower in the groups that consumed ready-to-eat foods (p=0.0002), ready-to-cook foods (p=0.0002), and meal-kits (p=0.0068) at least once a week compared to the groups that consumed them less than once a week. In conclusion, the results will serve as basic data for nutrition education for proper consumption of HMR among university students.
        4,200원
        19.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 본 연구는 무릎관절 치환술 환자를 위한 작업치료 임상 가이드라인을 체계적으로 개발하고자 하였다. 전 세계적으로 무릎관절 치환술을 받은 환자들의 회복과 지역사회 복귀에 있어 작업치료의 역할이 매우 중요하다는 문헌이 보고되고 있으나, 우리나라에서는 관절 치환술 환자를 위한 작업치료가 거의 제공되지 않는다는 현실이 있다. 본 연구에서는 무릎관절 치환술 환자를 위한 근거기반 작업치료 중재를 확인하고 이것을 가이드라인을 통해 제안하고자 한다. 연구방법 : 가이드라인 개발 방법은 영국 작업치료사협회의 「Practice guideline development manual(4th edition)」에서 소개한 절차를 따랐다. Patient/Population, Intervention, Comparison and Outcomes(PICO) 임상 질문 설정은 이해관계자의 의견을 수렴하여 한국의 보건·의료제도를 고려하여 설정하고 이를 바탕으로 체계적 고찰을 진행하였다. 데이터베이스에서 총 7,241건의 논문을 추출하였으며 논문의 질 평가 및 비평적 읽기를 통해 최종 66편의 근거 논문을 선정하였다. 논문의 중재를 바탕으로 가이드라인 내용을 구성하고 권고 강도는 Grading of Recommendations, Assessment, Development, and Evaluations(GRADE) approach 체계를 활용하여 [권고]와 [제안]으로 구분하였다. 결과 : 무릎관절 치환술 환자를 위한 작업치료 임상 가이드라인 권고 내용은 ‘환자 중심’과 ‘서비스 제공 중심’으로 범주화하였다. ‘환자 중심’범주에는 ‘일상생활 활동기능 향상’, ‘정신건강의 안정(불안, 우울 등)’, ‘환자 만족도 증가’, ‘지역사회복귀 향상’을, ‘서비스 제공 중심’범주에는 ‘작업치료사를 포함한 다학제 재활팀 구성’과 ‘작업치료 를 통한 병원 입원 기간 단축’을 위한 내용을 포함하였다. 결론 : 무릎관절 치환술 환자를 위한 작업치료 임상 가이드라인은 수술환자들의 안정적인 지역사회 복귀와 입원 기간 단축에 기여할 것이다. 또한 정형외과 작업치료사 역량 강화를 위한 교육자료로 활용될 수 있으며 의료비 용 감소를 위한 정책 마련에 근거 자료가 될 것이다.
        5,500원
        20.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        우리의 실생활과 산업 현장에서 인공지능·로봇이 일상화되기 시작하면 서 인공지능·로봇에 의한 인간 노동의 대체가 증가하고 있으며, 그 속도 또한 한층 빨라지고 있다. 이에 논 논문은 인공지능·로봇의 상용화에 의 해 발생할 수 있는 인간 노동 및 일자리의 대체에 따른 소득 불평등의 심화와 이에 대한 해결방안으로 제기되고 있는 로봇세 도입의 쟁점과 동 향 등을 분석하는 것을 목적으로 한다. 최근 인공지능·로봇의 상용화와 자동화 시스템의 도입으로 노동과 일자리의 대체가 빠르게 진행되고 있 는 가운데 로봇세 도입 논란이 가열되고 있다. 로봇세 도입에 반대하는 사람은 로봇세의 도입이 조세 형평의 원칙 위배와 기업의 경영 악화로 이어져 자본주의 경제질서의 근간을 저해할 수 있다고 주장한다. 반면에 로봇세 도입에 찬성하는 사람은 인공지능·로봇의 상용화에 따라 일자리 대체와 실업·빈곤 문제가 심각하게 나타나고 있으므로 인간의 일자리 상 실에 대한 보전과 생존권 보장, 그리고 재교육 등을 위한 세수 확보 수 단으로 로봇세의 도입이 필요하다고 주장한다. 이처럼 인공지능·로봇에 의한 인간 노동 및 일자리의 대체 경향이 강하게 나타날수록 로봇세 도 입을 둘러싼 논란은 앞으로 훨씬 더 증폭될 것으로 예상된다.
        6,600원
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