• 자원리싸이클링
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• 제3권1호
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• pp.44-51
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• 1994

PETqudds 부위별로 PET, HDPE, PVC, PP와 같은 여러 가지 다른 종류의 플라스틱으로 이루어져 있어 페 PET병의 재활용을 위하여서는 구성 성분별로 분리가 선행되어야 한다. 본 연구에서는 부상침강법에 의한 분리실험을 실시하였다. 수돗물을 사용하여 라벨을 제거한 후 부상침강 분리시키면 94%의 PET 회수율을 얻을 수 있었다. 라벨이 있을 경우에는 PVC와 PET가 침강하고 PP와 HDPE가 부상하므로 완전히 PET를 회수 할 수 없었다. 따라서 라벨을 제거시킨 후 분리를 시키든지 PVC 라벨의 재질을 PP나 PE로 교체하는 방안이 강구되어야 할 것으로 사료된다. 회수한 PET와 HDPE의 각종 물성을 측정하여 원재료와 비교해 본 결과 이들의 재활용이 가능함을 알 수 있었다.

• IMMUNE NETWORK
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• 제23권4호
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• pp.30.1-30.18
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• 2023

About 0.8 million people die because of hepatitis B virus (HBV) infection each year. In around 5% of infected adults, the immune system is ineffective in countering HBV infection, leading to chronic hepatitis B (CHB). CHB is associated with hepatocellular carcinoma, which can lead to patient death. Unfortunately, although current treatments against CHB allow control of HBV infection, they are unable to achieve complete eradication of the virus. Cytokines of the IFN family represent part of the innate immune system and are key players in virus elimination. IFN secretion induces the expression of interferon stimulated genes, producing proteins that have antiviral properties and that are essential to cell-autonomous immunity. IFN-α is commonly used as a therapeutic approach for CHB. In addition, IFN-γ has been identified as the main IFN family member responsible for HBV eradication during acute infection. In this review, we summarize the key evidence gained from cellular or animal models of HBV replication or infection concerning the potential anti-HBV roles of IFN-γ with a particular focus on some IFN-γ-inducible genes.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2006년도 춘계 종합학술대회 논문집
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• pp.279-284
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• 2006

미디어의 발달로 표현의 영역이 넓어진 영화 예술분야도 급속도로 성장해 왔다. 최근 한국 영화에서도 특수 효과(SFX)의 하나인 컴퓨터 그래픽스(CG)를 이용한 디지털 영화에 관심과 인력이 형성되고 있다. 본 논문에서는 형태가 갖는 게슈탈트 이론에 근거하여 한국 영화에서 3D 애니메이션이 삽입되어 2005년 최고의 흥행을 이루었던 <웰컴투 동막골>을 중심으로 그 조형성을 고찰하였다. 그 결과, 3D 애니메이션을 영화에 삽입함으로써 제작자의 의도에 따라 실사에서 느낄 수 없는 환영성이나 가상적인 세계를 이끌어 갈 수도 있으며 이는 촬영상의 공간의 제약을 받지 않는 자유로운 공간성이 적용되었음을 확인하였다. 또한, 지각의 대상에 전체성을 부여하며 완결을 필요로 하는 게슈탈트 이론에 의해 부분적인 애니메이션의 설정일지라도 영화의 의미를 파악하고 이해할 수 있는 역할을 할 수 있다는 것을 알 수 있었다.

• 한국전기전자재료학회논문지
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• 제25권8호
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• pp.602-610
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• 2012

The powders for the $Na_xWO_3$ (x= 1 and 0.75) sputtering targets were synthesized by the calcination in reductive atmosphere. Near single-phase $NaWO_3$ and single-phase $Na_{0.75}WO_3$ powder targets were prepared. By using the targets, thin films of each composition were deposited by rf magnetron sputtering on the $SiO_2$ (100 nm)/Si substrates and annealed by RTP (rapid thermal processing) for crystallization. In the case of the $NaWO_3$ composition, single-phase $Na_xWO_3$ thin films, where x was believed to be slightly less than 1, were fabricated accompanying the Na-diffusion into the substrates during RTP. However, in the case of the $Na_{0.75}WO_3$ thin film preparation, it was unable to make single-phase thin films. From the phase formation behaviors of both powders and thin films, it was revealed that $Na_xWO_3$ with nonstoichiometric composition of x, which was slightly less than 1, was favorable. The good electrical conduction properties were obtained from the single-phase $Na_xWO_3$ thin films. Their electrical resistivities were as low as $7.5{\times}10^{-4}{\Omega}{\cdot}cm$.

• 동력기계공학회지
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• 제17권5호
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• pp.78-85
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• 2013

A high thermal conductivity material, namely graphene is treated by planetary ball milling machine to transport the heat by increasing the temperature. Experiments were performed to assess the heat transfer enhancement benefits of coating the bottom wall of copper substrate with graphene. It is well known that the graphene is unable to disperse into base fluid without any treatment, which is due to the several reasons such as attachment of hydrophobic surface, agglomeration and impurity. To further improve the dispersibility and thermal characteristics, planetary ball milling approach is used to grind the raw samples at optimized condition. The results are examined by transmission electron microscopy, x-ray diffraction, Raman spectrometer, UV-spectrometer, thermal conductivity and thermal imager. Thermal conductivity measurements of structures are taken to support the explanation of heat transfer properties of different samples. As a result, it is found that the planetary ball milling approach is effective for improvement of both the dispersion and heat carriers of carbon based material. Indeed, the heat transfer of the ground graphene coated substrate was higher than that of the copper substrate with raw graphene.

• Journal of Communications and Networks
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• 제13권5호
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• pp.499-510
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• 2011

Any server offering a routing service in the Internet would naturally be in competition for clients, and clients may need to utilize service from a specific server in order to achieve a desired result. We study the various properties of this competition, such as the fraction of route requests handled by a routing service provider and the fraction of total revenue obtained. As the routing service providers (i.e., servers or routers in this context) compete, they may alter behavior in order to optimize one of the above properties. For example, a service provider may lower the price charged for its service, in order to increase the number of clients served. Our models are based on servers offering a routing service to clients within representative network topologies based on actual Internet sub-graphs. These models provide, a framework for evaluating competition in the Internet. We monitor key aspects of the service, as several variables are introduced into the models. The first variable is the fraction of client requests that will pay more for a better quality route. The remaining requests are normal client requests that are satisfied by the most economical route. The second variable is the fraction of servers who choose to lower service prices in order to maximize the number of client requests served. As this fraction increases, it is more likely that a server will lower the price. Finally, there are some resource constraints applied to the model, to increase the difficulty in providing a routing solution, i.e., to simulate a realistic scenario. We seek to understand the effect on the overall network, as service providers compete. In simple cases, we show that this competition could have a negative impact on the overall efficiency of a service. We show that the routing variety present in the larger models is unable to mask this tendency and the routing service performance is decreased due to competition.

• 한국식품과학회지
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• 제10권2호
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• pp.136-142
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• 1978

혐기성세균(嫌氣性細菌)인 C. saccharoperbutylacetonicum이 동조(同調) 농도(濃度)의 sucrose용액중(溶液中)에서 타(他) 용균효소(溶菌酵素) 또는 항생물질(抗生物質)을 첨가(添加)함이 없이 세포벽(細胞壁)이 급격(急激)히 용해(溶解)되어 구상(球狀)의 균(菌)으로 변화(變化)하는 특이(特異)한 현상(現象)이 확인(確認)되었다. 형성(形成)된 구상(球狀)의 균(菌)은 세포벽(細胞壁)이 완전(完全)히 제거(除去)된 원형질체(原形質體)로서 삼투압(壓) shock에 약(弱)하고 bacteriophage흡착능(吸着能)을 상실하였으며 분열증식(分裂增殖)이 불가능(不可能)하였다. 그러나 생체고분자(生體高分子)의 생합성(生合成)이 가능(可能)하며 mitomycin C처리(處理)에 의(依)하여 bacteriocin을 생산(生産)하였으며 분리(分離)한 phage DNA의 감염(感染)에 의(依)하여 자손(子孫) phage를 생산(生産)하였다. 즉(卽) 동조농도(同調濃度)의 sucrose 용액중(溶液中)에서 유기(誘起)되는 용균(溶菌)에 의(依)하여 생성(生成)된 구상(球狀)의 균(菌)은 세포벽(細胞壁)을 가지지 아니한 원형질체(原形質體)로서 모세포(母細胞)의 균학적(菌學的) 특성(特性)을 계승한 상태(狀態)에 있었으며 전형적(典型的)인 protoplast로 판단(判斷)되었다.

• Structural Engineering and Mechanics
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• 제30권6호
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• pp.713-732
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• 2008

Serviceability and durability of the concrete members can be seriously affected by the corrosion of steel rebar. Carbonation front and or chloride ingress can destroy the passive film on rebar and may set the corrosion (oxidation process). Depending on the level of oxidation (expansive corrosion products/rust) damage to the cover concrete takes place in the form of expansion, cracking and spalling or delamination. This makes the concrete unable to develop forces through bond and also become unprotected against further degradation from corrosion; and thus marks the end of service life for corrosion-affected structures. This paper presents an analytical model that predicts the weight loss of steel rebar and the corresponding time from onset of corrosion for the known corrosion rate and thus can be used for the determination of time to cover cracking in corrosion affected RC member. This model uses fully the thick-walled cylinder approach. The gradual crack propagation in radial directions (from inside) is considered when the circumferential tensile stresses at the inner surface of intact concrete have reached the tensile strength of concrete. The analysis is done separately with and without considering the stiffness of reinforcing steel and rust combine along with the assumption of zero residual strength of cracked concrete. The model accounts for the time required for corrosion products to fill a porous zone before they start inducing expansive pressure on the concrete surrounding the steel rebar. The capability of the model to produce the experimental trends is demonstrated by comparing the model's predictions with the results of experimental data published in the literature. The effect of considering the corroded reinforcing steel bar stiffness is demonstrated. A sensitivity analysis has also been carried out to show the influence of the various parameters. It has been found that material properties and their inter-relations significantly influence weight loss of rebar. Time to cover cracking from onset of corrosion for the same weight loss is influenced by corrosion rate and state of oxidation of corrosion product formed. Time to cover cracking from onset of corrosion is useful in making certain decisions pertaining to inspection, repair, rehabilitation, replacement and demolition of RC member/structure in corrosive environment.

• 대한간호학회지
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• 제30권5호
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• pp.1219-1229
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• 2000

The purpose of this study was to describe and understand how diabetics dealt with the result of the various changes of lifestyle. The grounded theory approach of qualitative research methods was used for building a substantive theory about that. The subjects of this study were 10 clients who experienced diabetes from 4 to 30 years. The data was collected from August 1999 to November 1999 through in-depth interviews utilizing home visitation and telephone interview technique then it was and analyzed simultaneously by a constant comparative method in which the new data was continuously coded into categories and properties according to Strauss & Corbin,s methodology. One hundred six concepts were found and they were grouped into 35 categories and then into 14 categories. The results were as follows difficulty, unable to overcome the changes, disposition, disease process, tiredness, supportive environment, perception, handling, concent- ration, mastering, endurance, avoidance, giving up and tailoring. The core phenomenon was 'tiredness' and these categories were synthesized into one core concept, the process of tailoring. The process of tailoring in diabetics consisted of : 1) going through difficulty of disease management 2) experiencing tiredness from the difficulty of disease management 3) perception of disease from tiredness 4) undergoing various self-management 5) controlling the process of tailoring by one's own method. Six hypotheses were derived from the relation of these concepts and four types were from intensity of tiredness, direction of disposition, type of disease process and the level of supportive environment and perception. This study offers better understanding on diabetic experiences and may facilitate more appropriate interventive strategies to provide support, information and knowledge. The nurses should utilize the results to help diabetics enjoy their lives without any trouble and must continuously develop nursing knowledges and skills.

• Journal of Microbiology and Biotechnology
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• 제27권4호
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• pp.747-758
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• 2017

Chronic wounds, pressure sores, lesions, and infections of microbial origin in bedridden, paralyzed, or malnutrition patients remain the object of study of many researchers. A variety of factors behind the development of these disorders are related to the patient's immune system, making it unable to respond effectively to the treatment of the wound. These factors can be properly controlled, giving particular importance to the ethiology and stage of the wound, as well as the time periods corresponding to the replacement of the dressings. The present research reports a novel foam/soft material, ${{\small}L}$-Cys-g-PCL, with an application for decubitus/pressure ulcers, especially for wounds with a difficult healing process due to infections and constant oxidation of the soft tissues. During this work, the interactions between S. aureus and ${{\small}L}$-Cys-g-PCL foam were studied under conditions that simulate decubitus ulcers; namely, pH and exudate. The effects of duration of grafting (1 or 8 h) and pH (7.0 and 8.9) on wettability, surface energy, swelling, and porosity were also evaluated. Results showed an effective microbicidal activity exhibiting an inhibition ratio of 99.73% against S. aureus. This new ${{\small}L}$-Cys-g-PCL soft material showed saftey to contact skin, ability to be shaped to fill in sunken holes (craters) - pressure ulcers stage III - and to act as a smart material responsive to pH, which can be tailored to develop better swelling properties at alkaline pH where exudates are normally higher, so as to address exudate self-cleaning and prevention of desiccation.