• 천문학회보
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• 제44권2호
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• pp.60.3-60.3
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• 2019

Binary systems of a white dwarf showing mass transfer activities are classified into cataclysmic variables and symbiotic stars. In the case of cataclysmic variables, the companion is usually a late type main sequence star filling its Roche lobe, where material is transferred through the inner Lagrangian point to form an accretion disk around the white dwarf. The disk becomes unstable and highly viscous when the surface density exceeds the critical density, leading to dwarf nova outbursts. In contrast, symbiotic stars are wide binary systems having a giant as the mass donor. Some fraction of giant stellar wind is accreted to the white dwarf giving rise to various symbiotic activities. In particular, half of symbiotics show Raman O VI at 6830 and 7088, which are important spectroscopic probe of mass transfer process. Monitoring observations using 1 m class telescopes will produce valuable information regarding the mass loss and mass transfer to white dwarf stars, shedding much light on the last stage of stellar evolution of low and intermediate mass stars.

• Steel and Composite Structures
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• 제48권2호
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• pp.235-250
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• 2023

The present paper examines the stability analysis of the buckling differentiae of the small-scale, non-uniform porosity-dependent functionally graded (PD-FG) tube. The high-order beam theory and nonlocal strain gradient theory are operated for the mathematical modeling of nanotubes based on the Hamilton principle. In this paper, the external radius function is non-uniform. In contrast, the internal radius is uniform, and the cross-section changes along the tube length due to these radius functions based on the four types of useful mathematical functions. The PD-FG material distributions are varied in the radial direction and made with ceramics and metals. The governing partial differential equations (PDEs) and associated boundary conditions are solved via a numerical method for different boundary conditions. The received outcomes concerning different presented parameters are valuable to the design and production of small-scale devices and intelligent structures.

• 센서학회지
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• 제32권4호
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• pp.213-218
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• 2023

Triboelectric nanogenerators (TENGs) have emerged as a highly promising energy harvesting technology capable of harnessing mechanical energy from various environmental vibrations. Their versatility in material selection and efficient conversion of mechanical energy into electric energy make them particularly attractive. TENGs can serve as a valuable technology for self-powered sensor operation in preparation for the IoT era. Additionally, they demonstrate potential for diverse applications, including energy sources for implanted medical devices (IMDs), neural therapy, and wound healing. In this review, we summarize the potential use of this universally applicable triboelectric energy harvesting technology in the disinfection and blocking of pathogens. By integrating triboelectric energy harvesting technology into human clothing, masks, and other accessories, we propose the possibility of blocking pathogens, along with technologies for removing airborne or waterborne infectious agents. Through this, we suggest that triboelectric energy harvesting technology could be an efficient alternative to existing pathogen removal technologies in the future.

• Journal of Plant Biotechnology
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• 제44권2호
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• pp.191-202
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• 2017

Chemical compounds from four different tissues of the kenaf plant (Hibiscus cannabinus), a valuable medicinal crop originating from Africa, were examined to determine its potential for use as a new drug material. Leaves, bark, flowers, and seeds were harvested to identify phytochemical compounds and measure antioxidant activities. Gas chromatography mass spectrometry analyses identified 22 different phytocompounds in hexane extracts of the different parts of the kenaf plant. The most abundant volatile compounds were E-phytol (32.4%), linolenic acid (47.3%), trisiloxane-1,1,1,5,5,5-hexamethyl-3,3-bis[(trimethylsilyl)oxy] (16.4%), and linoleic acid (46.4%) in leaves, bark, flowers, and seeds, respectively. Ultra-high performance liquid chromatography identified the major compounds in the different parts of the kenaf plant as kaemperitrin, caffeic acid, myricetin glycoside, and p-hydroxybenzoic acid in leaves, bark, flowers, and seeds, respectively. Water extracts of flowers, leaves, and seeds exhibited the greatest DPPH radical scavenging activity and SOD activity. Our analyses suggest that water is the optimal solvent, as it extracted the greatest quantity of functional compounds with the highest levels of antioxidant activity. These results provide valuable information for the development of environmentally friendly natural products for the pharmaceutical industry.

• 한국축산식품학회지
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• 제37권5호
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• pp.743-751
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• 2017

During slaughtering, animal blood is typically discarded, resulting in water pollution. However, this discarded blood has valuable components, such as immunoglobulin (Ig). Although several studies have been conducted to develop methods for effective recycling of slaughterhouse blood, they have not been commercially utilized in Korea. Here, we extracted an Ig-rich fraction from porcine blood that was then subjected to various in vitro tests, including pathogen growth inhibition, antigenic cross-reactivity, and anti-toxin activity. The porcine immunoglobulin concentrate (PIC) was effectively purified by eliminating other components, such as albumin, and consisted of approximately $63.2{\pm}2.9%$ IgG and $7.2{\pm}0.4%$ IgM on a protein basis. The results showed that it significantly suppressed the growth of pathogenic bacteria, and bound to all tested pathogens, including both gram-positive and gram-negative species, although the degree of activity differed according to strain. The PIC bound to two types of lipopolysaccharide (LPS) obtained from Escherichia coli O111:B4 and Salmonella enterica serotype typhimurium in a concentration-dependent manner. In addition, the PIC restored the proliferation activity of the lymphoblast K-562 cells when co-incubated with pathogenic LPS. These results confirm that the PIC prepared in this study is a potentially valuable functional food material or diet supplement as an alternative to antibiotics that can protect animals from pathogenic bacteria.

• 디자인학연구
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• 제13권3호
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• pp.293-302
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• 2000

인류의 문화 유산가운데 하나인 고전(古典)은 인류가 정보를 전달하고 의사소통을 하는데 있어 문자와 그림을 표현한 각종 전적류 가운데 역사적으로 가치 있는 기록이다. 이러한 고전들은 세월의 흐름에 따라 마멸, 훼손되거나 자연 산화함으로써 원본의 보존문제가 심각하게 대두되었으며, 이 고전들을 이용한 학술 연구에 많은 지장을 초래하고 있다. 이에 따라 세계 각지의 도서관과 미술관, 박물관에서 고전의 디지털화가 추진되어 자료의 손상을 막고, 보존성을 높이는 방법을 연구하고 있다. 고전의 디지털화는 단순히 고전을 디지털 이미지로 전환하는 것만을 의미하지 않는다. 고정밀의 디지털화상을 만들어 놓음으로써 고전이 가지고 있는 내용뿐만이 아니라 서지학적, 미술적, 고고학적인 자료로서의 가치를 유지하면서도 보존성을 높이고, 나아가이 디지털 자료를 네트워크를 통해 정보를 공유함으로써 보다 발전된 학술적 연구를 촉진하도록 하는데 의미가 있다. 본 연구는 고전을 디지털 화상처리 하는데 있어서 제반 원리와 방법을 고찰하고, 그 문제점과 의의를 연구함으로써 보다 효과적인 활용방법을 모색하는데 그 목적이 있다.

• 자원리싸이클링
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• 제16권3호
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• pp.27-33
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• 2007

구리, 주석 등의 유가금속을 다량 함유하고 있는 폐전기전자 스크랩으로부터 유가금속을 회수하는 것은 자원 재활용 측면에서 매우 중요하다. 본 연구에서는 폐동슬래그를 슬래그 형성제로 활용하여 폐전기전자 스크랩으로부터 유가금속을 추출하기 위한 새로운 공정이 제시되었다. 제안된 공정은 슬래그 형성제로 동 제련소에서 배출되는 폐동슬래그를 재활용한다는 장점이 있다. 각 실험에서는 일정한 비율로 혼합된 폐전기전자 스크랩과 폐동슬래그의 혼합시료를 보조 슬래그 형성제인 CaO와 함께 고온 용융되었다. 실험 결과 폐전기전자 스크랩에 함유된 구리와 주석이 Cu-Fe-Sn 합금상으로 각각 95% 이상, 85% 이상 추출되었다.

• 한국의사학회지
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• 제24권1호
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• pp.111-117
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• 2011

"Classified Assemblage of Medical Prescriptions(醫方類聚)" is a valuable material which can explain about historical records of East Asian medicine till 15th century. We can also konw what were regarded as important idea by contemporary doctors of Korean in 'Chosun' dynasty. And, Epilepsy is the one of the olddest diseases with a humankind history for a long time. All the concetps of disease including epilepsy in East Asia has been developed and specilized. So, we can find out some valuable facts from Epilepsy section in "Classified Assemblage of Medical Prescriptions". First, 'Epilepsy' was mixed with 'Mad', 'Spasm' before 7th century but after than, it had been divided into in detail. Since 14th century, we can find out that it was separated with 'Spasm' completely. In conclusion, 'Epilepsy' concept in "Classified Assemblage of Medical Prescriptions" at 15th century is similar with mordern 'Epilepsy' concept. Second, We can find out that 'Epilepsy disease' was divided into 'Five epilepsy' before 7th century, and divided into 'external cause', 'internal cause', 'external & internal cause' in 12th century. And, it also was divided into 'yin' or 'yang' epilepsy. So, 'Epilepsy' concept in " Classified Assemblage of Medical Prescriptions" at 15th century can be divided into 'yin' or 'yang' generally, and also it is similar with 'Acute and slow shock'. Especially, 'yinyang' of epilepsy is related to organs & bouls, depth & shallow, interior & exterior, not cold & heat definitely. From now on, the researches about how it had been understood in East Asia can help to find out modern significance of Korean medicine. and, it would be helpful for comprehensive study about "Classified Assemblage of Medical Prescriptions" from these researches in each section.

• 자원리싸이클링
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• 제21권4호
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• pp.76-85
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• 2012

조명기기는 일반적으로 램프벌브 내에 수은을 포함하고 있기 때문에 그대로 폐기하면 환경오염 등을 야기하는 우려가 있다. 한편, 조명기기의 수명은 방전특성의 저하 등에 근거하기 때문에 형광체층의 구성 재료인 형광체는 회수, 재생함으로써 재생형광체로서 재이용할 수가 있다. 또한, 유리벌브를 구성하는 유리재료에 관해서도 재이용이 가능하다. 본 연구에서는 폐조명기기의 재활용기술에 대한 특허와 논문을 분석하였다. 분석범위는 1977년~2011년까지의 미국, 유럽연합(EU), 일본, 한국의 등록/공개된 특허와 SCI 논문으로 제한하였다. 특허와 논문은 키워드를 사용하여 수집하였고, 기술의 정의에 의해 필터링하였으며 특허와 논문의 동향은 연도, 국가, 기업, 기술에 따라 분석하여 나타내었다. 폐조명기기로부터 금속을 회수하는 방법으로 산에 침지시켜 희토류 금속을 회수하는 기술이 주종이었으며 무해화 기술은 필터를 이용하여 수은을 제어하는 기술이 대부분이었다.

• International Journal of Reliability and Applications
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• 제7권1호
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• pp.27-39
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• 2006

Many real world cases in material failure analysis do not follow perfectly the normal distribution. Forcing of the normality assumption may lead to inaccurate predictions and poor product quality. We examine the failure process of the internal bond (IB or tensile strength) of medium density fiberboard (MDF). We propose a forced censoring technique that closer fits the lower tails of strength distributions and better estimates extremely smaller percentiles, which may be valuable to continuous quality improvement initiatives. Further analyses are performed to build an accelerated common-shaped Weibull model for different product types using the $JMP^{(R)}$ Survival and Reliability platform. In this paper, a forced censoring technique is implemented for the first time as a software module, using $JMP^{(R)}$ Scripting Language (JSL) to expedite data processing, which is crucial for real-time manufacturing settings. Also, we use JSL to automate the task of fitting an accelerated Weibull model and testing model homogeneity in the shape parameter. Finally, a package script is written to readily provide field engineers customized reporting for model visualization, parameter estimation, and percentile forecasting. Our approach may be more accurate for product conformance evaluation, plus help reduce the cost of destructive testing and data management due to reduced frequency of testing. It may also be valuable for preventing field failure and improved product safety even when destructive testing is not reduced by yielding higher precision intervals at the same confidence level.