검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 4,563

        781.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 비용매 유도 상분리와 소결 공정을 혼용하여 기체 및 액체에 대하여 슈퍼플럭스 거동을 보이는 니켈 모세관 지지체를 성공적으로 제조하였다. 니켈 모세관 전구체는 니켈, 폴리술폰, DMAC, PEG를 이용하여 도프용액을 제 조한 후 NIPS 공정에 의하여 제조된 후에, 다양한 소결온도에서 수소 분위기 조건에서 소결하여 니켈 모세관 지지체를 제조 하였다. 최적의 니켈 모세관 지지체는 950°C 소결온도에서 얻어졌는데 외경 722 μm, 내경 550 μm, 두께 94 μm이었다. 니켈 모세관 지지체 기공율은 26%, 평균 기공경은 4 μm이었으며 3차원으로 서로 연결된 기공구조를 갖고 있었다. 그리고 파괴하 중은 2.84 kgf, 파괴 연신율은 13%이었다. 니켈 모세관 지지체의 He, N2, O2, CO2에 대한 단일 기체 투과도는 상온에서 각각 432,327, 281,119, 264,259, 193,143 GPU로 슈퍼플럭스 거동을 보였다. 이는 3차원적으로 서로 연결된 4 μm 크기 마크로기 공을 통하여 viscous flow가 일어났기 때문에 나타나는 현상으로 설명되었다.
        4,000원
        782.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We report a method for preparing rare earth oxides (RexOy) from the recycling process for spent Ni-metal hydride (Ni-MH) batteries. This process first involves a leaching of spent Ni-MH powders with sulfuric acid at 90℃, resulting in rare earth precipitates (i.e., NaRE(SO4)2·H2O, RE = La, Ce, Nd), which are converted into rare earth oxides via two different approaches: i) simple heat treatment in air, and ii) metathesis reaction with NaOH at 70℃. Not only the morphological features but also the crystallographic structures of all products are systematically investigated using field-emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD); their thermal behaviors are also analyzed. In particular, XRD results show that some of the rare earth precipitates are converted into oxide form (such as La2O3, Ce2O3, and Nd2O3) with heat treatment at 1200℃; however, secondary peaks are also observed. On the other hand, rare earth oxides, RExOy can be successfully obtained after metathesis of rare earth precipitates, followed by heat treatment at 1000℃ in air, along with a change of crystallographic structures, i.e., NaRE(SO4)2·H2O → RE(OH)3 → RExOy.
        4,000원
        783.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, a new Co10Fe10Mn35Ni35Zn10 high entropy alloy (HEA) is identified as a strong candidate for the single face-centered cubic (FCC) structure screened using the upgraded TCFE2000 thermodynamic CALPHAD database. The Co10Fe10Mn35Ni35Zn10 HEA is fabricated using the mechanical (MA) procedure and pressure-less sintering method. The Co10Fe10Mn35Ni35Zn10 HEA, which consists of elements with a large difference in melting point and atomic size, is successfully fabricated using powder metallurgy techniques. The MA behavior, microstructure, and mechanical properties of the Co10Fe10Mn35Ni35Zn10 HEA are systematically studied to understand the MA behavior and develop advanced techniques for fabricating HEA products. After MA, a single FCC phase is found. After sintering at 900℃, the microstructure has an FCC single phase with an average grain size of 18 μm. Finally, the Co10Fe10Mn35Ni35Zn10 HEA has a compressive yield strength of 302 MPa.
        4,000원
        784.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 가교막을 poly(2,6-dimethyl-1,4-phenylene oxide)(PPO)에 브롬화반응을 통해 제조한 Br-PPO를 주 사슬로 성공적으로 제조하였고, 키토산과 4차암모늄이 포함된 키토산을 가교제로 사용하였다. 제조된 가교막은 트리메틸아민 용액에 함침하여 후처리를 진행하였다. 그리고 가교도는 가교제 비율을 이용하여 조절하였다. 이렇게 제조된 A-PPO + chitosan 가교막과 A-PPO + QA-chitosan 가교막의 이온교환막으로써의 가능성을 여러 특성평가로 확인하였다. Chitosan을 사용한 가교막보다 QA-chitosan을 사용한 가교막이 가교가 더 잘 이루어졌으며, QA-chitosan의 함량이 증가할수록 이온교환용량이 1.18 meq/g에서 1.53 meq/g까지 증가하는 경향, 함수율이 21.6%에서 42.2%까지 증가하는 경향을 나타내었다.
        4,000원
        785.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Polyvinylidene fluoride (PVDF)의 중공사막 표면에 2번 딥코팅하여 layer-by-layer 방식으로 나노복합막을 제조하 였다. 1차 코팅에서 poly(vinylsulfonic acid)(PVSA)와 Poly(styrene sulfonic acid)(PSSA)의 농도, 이온세기(Ionic strength, IS) 등을 변화시키며 막을 제조하였으며, 2차 코팅 용액으로는 Poly(ethyleneimine) 10,000 ppm I.S = 0.3으로 고정하였다. 막의 특성평가를 위해 각각의 100 ppm NaCl, CaSO4, MgCl2, 그리고 25 ppm Methyl Orange (MO) 공급액에 대한 막의 투과도와 염배제율을 측정하였다. 코팅용액의 코팅 물질의 농도가 올라갈수록 염배제율이 상승하였으며, 본 실험 조건에서 PVSA보다 는 PSSA를 이용하여 제조한 중공사막이 염배제율이 높은 것을 확인하였다. 대표적으로 PSSA 30,000 ppm I.S = 1.0에서 중공사막을 제조하였을 때 25 ppm MO용액의 투과도 1.848 LMH, 염배제율 76.3%로 가장 높은 값을 나타내었다.
        4,000원
        786.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 소와 돼지 식육부산물의 위생처리를 위한 볼텍스 튜브를 이용한 오존수 제조 장치를 개발 하기 위해 수행되었다. 오존가스발생에 있어서 가장 중요한 인자는 원료공기의 온도이며, 위생처리를 위한 오존수 내 오존농도에 크게 영향을 미친다. 이러한 이유 때문에 오존발생기로 유입되는 원료공기의 온도를 낮추기 위해 볼텍스 튜브가 이용되었다. 성능평가의 결과에 의하면, 공기압축기의 배출공기 압력 3~5bar, 볼텍스 튜브의 냉기비율 40~80%와 냉각공기의 압력 0.0~0.4bar가 28.2℃의 주변 공기 온도 하에서 볼텍스 튜브의 냉각공기의 온도에 교호적으로 작용하는 것으로 나타났으며(p<0.05), 최적 조건은 공기압축기의 배출공기 압력 4bar, 볼텍스 튜브의 냉기비율 40%, 냉각공기의 압력 0.3bar이었다. 최적조건과 주변 공기온도 35℃ 하에서 볼텍스 튜브를 이용한 오존수 제조 장치의 성능을 평가한 결과에 의하면, 오존수 내 오존농도가 0.43ppm 이상이었다. 따라서 볼텍스 튜브를 이용한 오존수 제조 장치의 성능이 우수하여 여름철 악조건 하에서도 이용이 가능한 것으로 판단된다.
        4,000원
        789.
        2018.06 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 국민생활안전에 밀접한 영향을 미치는 식품안전 패키징 기술 개발을 위하여, 식품의 신선도를 나타낼 수 있고, 신선식품의 부패 과정에서 발생하는 휘발성 염기질소 등 다양한 부패생성물을 감지하기 위한 색변환 센서기술을 연구하였다. 잉크젯, 바-코팅, 그라비아 등의 다양한 인쇄 방법을 통해 원가 경쟁 력이 우수한 스마트 패키징 제품 개발을 위해 신선육의 부패에 따른 pH 변화 범위 내에서 분명한 색변환 특성을 나타내는 염료와 수용성 고분자 지지체를 활용해 신선도 지시계 용도의 잉크를 제조 한 후, 소고기, 닭고기, 돼지고기 등의 신선육의 부패에 따른 휘발성 염기질소 반응 정도를 측정하여 센서의 감도 및 신뢰도를 연구하였다.
        4,000원
        790.
        2018.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Currently, the Korea Atomic Energy Research Institute (KAERI) is planning to build the Ki-Jang Research Reactor (KJRR) in Ki-Jang, Busan. It is important to safely dispose of low-level radioactive waste from the operation of the reactor. The most efficient way to treat radioactive waste is cement solidification. For a radioactive waste disposal facility, cement solidification is performed based on specific waste acceptance criteria such as compressive strength, free-standing water, immersion and leaching tests. Above all, the leaching test is important to final disposal. The leakage of radioactive waste such as 137Cs causes not only regional problems but also serious global ones. The cement solidification method is simple, and cheaper than other solidification methods, but has a lower leaching resistance. Thus, this study was focused on the development of cement solidification for an enhancement of cesium leaching resistance. We used Zeolite and Loess to improve the cesium leaching resistance of KJRR cement solidification containing simulated KJRR liquid waste. Based on an SEM-EDS spectrum analysis, we confirmed that Zeolite and Loess successfully isolated KJRR cement solidification. A leaching test was carried out according to the ANS 16.1 test method. The ANS 16.1 test is performed to analyze cesium ion concentration in leachate of KJRR cement for 90 days. Thus, a leaching test was carried out using simulated KJRR liquid waste containing 3000 mg·L-1 of cesium for 90 days. KJRR cement solidification with Zeolite and Loess led to cesium leaching resistance values that were 27.90% and 21.08% higher than the control values. In addition, in several tests such as free-standing water, compressive strength, immersion, and leaching tests, all KJRR cement solidification met the waste acceptance or satisfied the waste acceptance criteria for final disposal.
        4,200원
        794.
        2018.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was to demonstrate the comparison of immunological activity between vegetable soup made by fresh and extruded radish in in-vitro (bone marrow-derived macrophages and dendritic cells, and mouse splenocytes) and invivo models. In cell survival tests, extruded radish added to vegetable soup (EVS) and non-extruded radish added to vegetable soup powder (NEVS) were treated with bone-marrow derived macrophages, dendritic cells, and mouse splenocytes, and showed no cytotoxic effect at a dose below 1000 μg/mL. EVS treated cells had greater cell proliferation and cytokine [tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, IL-2, interferon (INF)-γ] production when compared to the NEVS treated group. Cell surface marker (CD 80/86, MHC class I/II) expression in bone marrow-derived macrophages and dendritic cells was evenly increased in the EVS treated group. In in-vivo study, administration of EVS increased for the CD4 and CD8 T cell population in splenocyte and cytokine production (IL-2, IFN-γ, TNF-α) but not Th2 type cytokines (IL-4). Therefore, adding the extruded radish is a more effective method for vegetable soup to increase immunological activity against immune cells.
        4,300원
        795.
        2018.05 구독 인증기관·개인회원 무료
        제조물책임법은 제품의 제조, 설계, 표시상의 결함으로 인해 사용자의 생명이나 신체에 피해나 손실이 발생할 경우 제조물의 결함과 그로 인한 피해 사실이 입증되면 제조업자 등이 손해배상책임을 지게 하는 제도이다. 제조물책임법의 시행으로 기업은 제조물책임 사고로 인한 손실을 예방하고 체계적으로 방어할 수 있는 대응시스템을 구축하여 제품안전사고를 본질적으로 근절하기 위한 책무를 다해야 한다. 그렇지만 최근에 발생한 가습기살균제 사고, 휴대폰 배터리의 결함, 정수기 리콜 등에 의한 피해발생으로 제품의 안전을 근원적으로 확보하고 소비자의 생명과 재산을 보호하는 데 제도적으로 미흡한 점이 발견되어 개선 할 필요성이 대두되었다. 이에 국회에서는 제조물책임법의 실효성을 강조하기 위하여 2017년 3월 제조물책임법의 개정을 통해서 피해액의 최고 3배까지 배상토록 하는 징벌적 배상제도, 소비자에게 피해발생 시 입증책임을 제조업체가 지도록 하는 입증책임의 전환 등을 개정하게 되었다. 이러한 변화는 앞으로 기업 책임의 변화를 예상하게 된다. 따라서 본 연구에서는 개정된 제조물책임법이 기업에 미치는 영향을 살펴보고 기업이 효과적으로 대응할 수 있도록 대응전략을 제시하고자 한다.
        796.
        2018.05 구독 인증기관·개인회원 무료
        The International Organization for Standardization published ISO 9001 Quality Management System– Requirements in 1987 and has revised four times since then. ISO 9001:2015 is the latest edition. This latest edition has two most noticeable changes. The first major change of new edition focuses on performance with an emphasis on Risk-Based Thinking (RBT) to enhance the process approach. The new edition consists of ten clauses whose first three clauses are largely same as older edition but risks are clearly stated and stressed in last seven clauses, emphasizing on Plan-Do-Check-Act cycle at all levels in the organization. The second major change is that the new edition has the same overall structure as other ISO management system standards known as High Level Structure with Annex SL. In this article we aim to statistically analyze minor nonconformities found in different types of transition audits. We try to interpret the findings and summarize the implications of the statistical results.
        797.
        2018.05 구독 인증기관·개인회원 무료
        The 4th industrial revolution is in its progressive form, and its effects are already being revealed throughout society. It has led to a variety of new technologies including artificial intelligence (AI), big data, Internet of Things (IoT), robotics, cyber-physical systems, biotechnology, 3D printers, drones, and Uber. The winds of this revolution are expected to bring many changes to the manufacturing industry. The low-growth global economy and a decline in productivity are prompting a 4th industrial revolution centered on Europe’s Germany, as it needed new growth engines. In Korea, manufacturing industries focused on labor and capital were the center of the industry. The goal was to pursue the first and second industrial revolution led by the developed countries, and to achieve what is called the “Miracle of the Han River”, “The Four Dragons for Asia”, and “The East Asian Miracle”. However, unlike the past, the 4th industrial revolution is not expected to bring about theoretical but substantial changes. The preparations and research into the 4th industrial revolution may seem to be ahead of the major countries, but unfortunately it is far behind the major ones. The United States, China, Germany and Japan are in the process of reorganizing the society, culture and economy in relation to the 4th industrial revolution. Korea`s economy, however, is showing a decline in the growth rate, with the exception of technical hardware and equipment and telecommunications. The 4th industrial revolution is an industry that requires highly specialized knowledge, information, and technology, and if it fails to respond to rapidly evolving technological changes and trends, it is bound to be relegated to the government's position. For small and medium sized manufacturers in particular, the longer the preparation is delayed due to poor environment, structural backwardness, lack of core competencies, and lack of innovation, the more likely they will adjust to social and technological changes caused by the 4th industrial revolution. Accordingly, it is necessary to enhance the importance of preparation for the 4th Industrial Revolution and to take strategic approaches to enhance the sophistication of technologies and the autonomy of small and medium sized manufacturing companies. In this study, we intend to study the manufacturing-ready effects of manufacturing industries based on the level of perception of the company’s 4th industrial revolution. For this purpose, 122 small and medium manufacturing companies were surveyed on the 4th industrial revolution. The survey was conducted for about four months from December 1, 2017 to March 31, 2018. In the case of small and medium sized manufacturing companies, a hypothesis was established on how the perception and preparation of the industrial revolution affects the direct preparation of the 4th industrial revolution. Three assumptions were presented depending on the level of perception of the 4th industrial revolution and the data were drawn from the questionnaire. When comparing the data to the hypothesis, small and medium manufacturing companies should be able to determine the level of interest they have in the 4th Industrial Revolution, and if they are not prepared to do so, they should be able to invest in a certain extent.
        798.
        2018.05 구독 인증기관·개인회원 무료
        We fabricated dual-phase free-standing polymeric membrane for high performance CO2/N2 separation, introducing amphiphilic, CO2-philic copolymer via one-step free radical polymerization, or (2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate)-graft-poly(oxyethylene methacrylate) (PBE). PBE filler partially interacts with Pebax polymer matrix to generate the interconnected CO2 philic network, exhibiting a microphase-separated, or dual-phase behavior in Pebax matrix. The performance of CO2/N2 separation was increased according to the PBE content, with the maximum selectivity at 5 wt%. The enhancement of Pebax/PBE CO2-philic membrane was attributed to the formation of CO2-philic channel consisting of ether oxygens and triazole groups. The best performance was CO2 permeability of 175.3 Barrer and CO2/N2 selectivity of 48.2.
        799.
        2018.05 구독 인증기관·개인회원 무료
        In this study, we prepared thin composite membranes in which a support layer and a selective layer are covalently bonded in a simple method. The graft polymerization was carried out using UV/Ozone on a commercial Poly(sulfone) (PSf) ultrafiltration membrane with Poly((ethylene glycol) methyl ether methacrylate) (PEGMA) possessing CO2affinity. As a result, nano-pores on the surface membrane were covered with PEGMA. The covalent bonding of the composite membranes has the advantage of improving stability. In addition, due to the thin selective layer formed by the graft polymerization, highly gas permeation characteristics are exhibited, and efficient process performance can be expected. The final composite membranes were investigated in terms of their chemical structures and elements, morphology, and gas permeation properties.
        800.
        2018.05 구독 인증기관·개인회원 무료
        Commercial polystyrene-based ion exchange membranes have simple manufacturing processes, they also possess the poor durability due to their brittleness. Poly(ethylene glycol)methyl ether methacrylate with hydrophilic side chain of poly(ethylene glycol) (PEG) was used as a co-monomer to make the membranes have improved flexibility. Hydrophilicity of the anion exchange membrane was able to be adjusted by varying the chain lengths of the PEG polymers. For the preparation of the anion exchange membranes, a porous PE substrate was immersed into monomer solutions and thermally polymerized and crosslinked. The prepared membranes were then subsequently post-aminated using trimethylamine (TMA). The prepared pore-filled anion exchange membranes were evaluated in terms of ion exchange capacity (IEC), electric resistance (ER) and water uptake.