• 한국환경과학회지
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• 제6권4호
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• pp.379-384
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• 1997

The biodegradable characteristics of poly-$\beta$-hydroxybutyrate(PHB) film by fun맥 and soil burial are Investigated. As the results of the American Standards for Testing and Materials(ASTM) method, the you of Aspergillus niger was apparent on the PHB containing plate. This suggests that PHB was utilized as the sole carbon source by Aspergillus niger and ASTM method may have applications as measuring means of biome gradability of polyhydroxyalkanoic acid(PHA). PHB film was studied by monitoring the time-dependant changes in weight loss of PHB film under 30% and relative humidity 80 % during pot-test. As the results of pot-test, PHB film was decomposed about 87 % in 30 days by soul microorganisms. PHB film was more slowly degraded than PHB/HV film.

• Journal of the Korean Wood Science and Technology
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• 제52권2호
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• pp.157-174
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• 2024

This study investigates the influence of varying concentrations of boric acid (BA) preservative on the physical and mechanical properties of light red meranti (LRM) found in Sarawak. LRM or Shorea leprosula samples were treated with various concentrations of BA via the dip diffusion method using American Society for Testing and Materials (ASTM) standards. The physical property, particularly the retention rate and mechanical properties, bending strength, modulus of elasticity (MOE), tensile and compression strength parallel to grain of impregnated and control samples were tested to determine the effects of BA preservative. The retention rate was found to increase with increasing BA concentration and higher surface area to volume ratio. The mechanical properties in terms of the MOE and tensile strength parallel to grain were found to be greater than those of the control samples, whereas the bending strength and tensile strength parallel to grain were lower. Amongst the results, only the retention rate and MOE showed significant interaction effects at 5% level of significance between all factors tested (samples size and BA concentration for retention rate and BA concentration for MOE).

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2000년도 추계수산관련학회 공동학술대회발표요지집
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• pp.256-257
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• 2000

해양의 생물자원 또는 수산생물에게 저해영향을 미치는 오염물질의 농도를 결정하는 수단으로서 현재 전세계적으로 가장 널리 사용되고 있는 것은 표준실내 생물검정시험(Standard Laboratory Bioassay)을 들 수 있다. ASTM(American Society for testing and Materials), OECD(Organization for Economic Cooperation and Development), USEPA(Unated States Environmental Protection Agency)와 같은 단속기관에서는 연안에 방출되는 오염물질에 대한 허용한계농도를 정하기 위하여 급성 독성 결과를 기준으로 하고 있으며, ASTM과 OECD에서는 생육초기독성 시험을, USEPA에서는 생육초기 독성시험과 만성독성을 채택하고 있다. (중략)

• International Journal of Human Ecology
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• 제7권1호
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• pp.77-83
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• 2006

The ability to customize garments for fit in the apparel industry is directly tied to the availability of comprehensive and accurate sets of anthropometrical data for each consumer. The data for apparel sizing systems is available from three major standard/ research organizations: ASTM (American Society for Testing and Materials), ISO (International Standard Organization), and NCHS (National Center for Health Statistics). However, these standards ignore various head shapes and are outdated for the development future head products. This creates a data gap an ever changing multi-cultural society such as the United Sates. Although major government and industry safety organizations recognize the importance of safety for head products, few studies were found to support their reasoning. The purpose of this study is to provide accurate head dimension data for developing safety head products by analyzing various head shapes in the United Sates which includes various ethnic backgrounds. This study was carried out on 105 males in the United States. Factor analysis, cluster analysis, Moreover, Duncan analysis were all used for analyzing various head shapes.

• 한국지반공학회논문집
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• 제39권7호
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• pp.39-48
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• 2023

동상으로 인한 구조물의 피해를 방지하고자 세계 100여개의 국가에서는 토양의 동상민감성을 판정하는 실내실험법에 대해 연구를 진행하였다. 미국과 일본은 알래스카와 홋카이도와 같은 동토지역을 포함하고 있어 동상에 대한 연구가 활발히 진행되었으며, 연구 결과와 현장 적용을 통해 동상민감성 판정 표준 실험법과 기준을 제시하고 있다. 그러나 실험 방법이 복잡하고 공학적인 해설이 부족하며, 결과 분석에 대한 논리가 모호한 부분이 여전히 존재하고 있다. 본 논문에서는 이러한 미국 ASTM(American Society for Testing and Materials)과 일본 JGS(Japanese Geotechnical Society)의 동상 실험법을 동상 실험에 미치는 온도조건, 시료크기, 동결방향, 배수조건 등을 고려하여 면밀히 비교 분석하고, 지금까지 연구결과를 종합하여 향후 국제적인 연구동향에 부합하는 국내 동상민감성 판정 실험법과 기준의 방향을 제시하고자 한다.

• 청정기술
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• 제17권3호
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• pp.215-224
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• 2011

화석연료 사용에 따른 기후 변화 문제 및 자원 고갈에 대한 염려 때문에 바이오 연료는 그 중에서 가장 바람직한 재생에너지 대안이다. 하지만 대량 생산을 할 수 있는 경제성확보가 없으면 바람직하고 현실적인 대안이라 할 수 없다. 실시간 품질측정 시스템 개발은 바이오연료의 대량생산을 위하여 반드시 필요하다. 바이오 연료 중 바이오에탄올은 ASTM (American Society for Testing & Materials) D4806-10과 같은 품질 규격을 따르며 이에 명시된 평가방법을 대량 생산에 적용하려면 여러 어려움이 뒤따른다. 따라서 본 연구에서는 바이오에탄올 제품 품질 분석의 저가격화와 시간단축 및 생산 공정의 모니터링 실시간화를 해결하기 위해 근적외선 분광분석법과 화학계량학의 부분최소 자승법(Partial Least Squares)을 융합한 실시간 분광 모니터링 시스템을 새롭게 제안하였다. 수종의 전처리와 부분최소자승법을 이용하여 모델링한 결과 스펙트럼의 산란 보정, 노이즈 감소, 검량선의 유지보수 등에서 Savitzky-Golay 전처리가 가장 우수함을 보였다. 본 연구를 통해 실시간으로 품질 측정뿐만 아니라 분광분석 장치로 여러 성분을 동시에 측정 가능함을 보임으로서 비용의 절감도 가능할 것으로 예상된다. 그리고 상관계수 R2이 0.99 이상으로 실험실분석의 대체도 가능함을 보였다.

• Nuclear Engineering and Technology
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• 제48권1호
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• pp.200-210
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• 2016

The neutron radiography reactor (NRAD) is a 250 kW Mark-II Training, Research, Isotopes, General Atomics (TRIGA) reactor at Idaho National Laboratory, Idaho Falls, ID, USA. The East Radiography Station (ERS) is one of two neutron beams at the NRAD used for neutron radiography, which sits beneath a large hot cell and is primarily used for neutron radiography of highly radioactive objects. Additional fuel elements were added to the NRAD core in 2013 to increase the excess reactivity of the reactor, and may have changed some characteristics of the neutron beamline. This report discusses characterization of the neutron beamline following the addition of fuel to the NRAD. This work includes determination of the facility category according to the American Society for Testing and Materials (ASTM) standards, and also uses an array of gold foils to determine the neutron beam flux and evaluate the neutron beam profile. The NRAD ERS neutron beam is a Category I neutron radiography facility, the highest possible quality level according to the ASTM. Gold foil activation experiments show that the average neutron flux with length-to-diameter ratio (L/D) = 125 is $5.96{\times}10^6n/cm^2/s$ with a $2{\sigma}$ standard error of $2.90{\times}10^5n/cm^2/s$. The neutron beam profile can be considered flat for qualitative neutron radiographic evaluation purposes. However, the neutron beam profile should be taken into account for quantitative evaluation.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.621-626
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• 2001

Microcellular foaming process was developed at MIT in 1980's to save a quantity of raw materials and improve mechanical properties. There are many process variables in appling microcellular foaming process to the conventional injection molding process. Of all process variables, part dimension control and shrinkage are the most influential on the post molded dimension. The post molding dimensional change of thermoplastic resins is important to tool designers for predicting the specific difference of molded part vs. actual mold cavity. Generally, articles injection molded are smaller in size than the cavity; hence, the term shrinkage factor is used to define the allowance a designer specifies. It is important to consider the factors that influence molded part dimension. According to ASTM Designation: D 955, shrinkage from mold dimensions of molded plastics was measured. In injection molding, the difference between the dimensions of the mold and of the molded article produced therein from a given material may vary according to the design and operation of the mold. In this paper, shrinkage data of molded plastic parts was obtained. It can be an important information for designing optimum mold system in a microcellular foaming injection molding process.

• 터널과지하공간
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• 제30권3호
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• pp.181-192
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• 2020

Pin-on-disk 시험방법은 ASTM에서 제안한 마모시험방법 중 하나이다. 이 시험법에서는 Pin-on-disk 시험에서 나타나는 핀의 나선운동을 간략히 설명하고 있다. 이 방법을 암석공구의 마모성능을 평가하는데 적용하기 위해서는 핀의 등속도 운동을 수학적으로 구현하여야 한다. 먼저 합산속도에 관여하는 2가지 속도성분(핀의 선형이동속도, 디스크의 회전운동)을 정의하였다. 각각의 성분에 대해 아르키메데스 나선방정식의 등속도 조건을 만족하는 미분방정식을 전개하여 수학 해를 도출하여, 풀이의 난해함을 설명하였다. 이를 해결하기 위한 기존 문헌의 근사해를 조사하고, 정확도와 한계점을 분석하였다.

• 한국소음진동공학회논문집
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• 제26권3호
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• pp.235-241
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• 2016

Underwater weapon system is required to structurally strong material, since as it is directly exposed to external shock. It should also be using the lightweight material in order to take advantage of buoyancy. Composite materials meet these requirements simultaneously. Particularly in the case of submarine, composite materials are widely used. It is important to have a high strength enough to be able to withstand external shock, but it is also important to attenuate it. In a method for the shock damping, viscoelastic damping materials are inserted between the high strength composite material as a sandwich structure. Shock attenuation can be evaluated in the loss factor. In ASTM(American Society of Testing Materials), evaluation method of the loss factor of cantilever specimens is specified. In this paper, mode tests of the cantilever are performed by the ASTM standard, in order to calculate the loss factor of the viscoelastic damping material by the specified expression. Further, for verifying of the calculated loss factor, mode test of compound beams is carried out. In addition, the characteristics of the material were analyzed the effect on the loss factor.