• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1246-1246
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• 2001

The quality of meat is highly variable in many properties. This variability originates from both animal production and meat processing. At the pre-slaughter stage, animal factors such as breed, sex, age contribute to this variability. Environmental factors include feeding, rearing, transport and conditions just before slaughter (Hildrum et al., 1995). Meat can be presented in a variety of forms, each offering different opportunities for adulteration and contamination. This has imposed great pressure on the food manufacturing industry to guarantee the safety of meat. Tissue and muscle speciation of flesh foods, as well as speciation of animal derived by-products fed to all classes of domestic animals, are now perhaps the most important uncertainty which the food industry must resolve to allay consumer concern. Recently, there is a demand for rapid and low cost methods of direct quality measurements in both food and food ingredients (including high performance liquid chromatography (HPLC), thin layer chromatography (TLC), enzymatic and inmunological tests (e.g. ELISA test) and physical tests) to establish their authenticity and hence guarantee the quality of products manufactured for consumers (Holland et al., 1998). The use of Near Infrared Reflectance Spectroscopy (NIRS) for the rapid, precise and non-destructive analysis of a wide range of organic materials has been comprehensively documented (Osborne et at., 1993). Most of the established methods have involved the development of NIRS calibrations for the quantitative prediction of composition in meat (Ben-Gera and Norris, 1968; Lanza, 1983; Clark and Short, 1994). This was a rational strategy to pursue during the initial stages of its application, given the type of equipment available, the state of development of the emerging discipline of chemometrics and the overwhelming commercial interest in solving such problems (Downey, 1994). One of the advantages of NIRS technology is not only to assess chemical structures through the analysis of the molecular bonds in the near infrared spectrum, but also to build an optical model characteristic of the sample which behaves like the “finger print” of the sample. This opens the possibility of using spectra to determine complex attributes of organic structures, which are related to molecular chromophores, organoleptic scores and sensory characteristics (Hildrum et al., 1994, 1995; Park et al., 1998). In addition, the application of statistical packages like principal component or discriminant analysis provides the possibility to understand the optical properties of the sample and make a classification without the chemical information. The objectives of this present work were: (1) to examine two methods of sample presentation to the instrument (intact and minced) and (2) to explore the use of principal component analysis (PCA) and Soft Independent Modelling of class Analogy (SIMCA) to classify muscles by quality attributes. Seventy-eight (n: 78) beef muscles (m. longissimus dorsi) from Hereford breed of cattle were used. The samples were scanned in a NIRS monochromator instrument (NIR Systems 6500, Silver Spring, MD, USA) in reflectance mode (log 1/R). Both intact and minced presentation to the instrument were explored. Qualitative analysis of optical information through PCA and SIMCA analysis showed differences in muscles resulting from two different feeding systems.

• 한국지반환경공학회 논문집
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• 제9권5호
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• pp.37-43
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• 2008

무기질계 주입재는 지반개량 재료로서 기존의 물유리계 재료를 사용할 경우 발생하는 용출현상 및 강도저하를 보완한 시멘트계 급결재와 무기질계 초미립자를 주원료로 하는 순수 무기질 재료를 사용한 것으로서, 시공 후 내구성 및 강도가 우수하고 주입재의 용출 현상이 발생하지 않아 환경오염 문제가 거의없는 영구적인 차수 및 보강에 적합한 친환경적인 재료이다. 본 연구는 지반개량 재료로서 급결성 시멘트계 재료와 순수 무기질 주입재를 주원료로 배합된 MIS(Micro Injection-process System)와 기존에 많이 쓰여지고 있는 물유리계 주입재인 SGR의 내구성 및 친환경적특성을 일축압축강도시험, 내화학성시험, 어독성시험, 화학성분 분석 등의 실험으로 비교 분석 하였다. 일축압축 시험결과 재령 28일 강도는 MIS가 SGR재료에 비해 1.7배 크게 발현 되었고, 재령 40일 이후 SGR재료는 강도가 저하하는 반면 MIS는 지속적으로 증가하는 경향을 보였다. 내화학성시험 결과 MIS의 길이변화율이 물유리계주입재에 비해 10배~25배 작게 나타났다. 그리고, 어독성시험 결과 MIS가 물유리계주입재에 비해 친환경적임이 증명되었고, 화학성분 분석 결과 MIS 용출액이 물유리계주입재의 용출액에 비해 $Cr^{6+}$, Pb, Si 성분이 적게 검출됨을 확인할 수 있었다. 따라서, MIS 주입재는 기존의 SGR 주입재에 비해 고강도로 공기단축 및 기초지반의 구조적 안정성이 우수하며 친환경적이라 지하수오염 등의 문제도 적을 것으로 판단된다.

• Journal of the Korean Wood Science and Technology
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• 제44권4호
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• pp.571-588
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• 2016

Eucalyptus pellita F. Muell is one of pulp woods that is being developed through breeding plantation programs in Indonesia. The research aimed at exploring the chemical and morphological characteristics of fiber, and to determine the rank of plus trees from 4 provenances based on the suitability for pulps. The materials included the plus trees of E. pellita (9 years) from the 2nd generation of progeny tests in Pelaihari, South Borneo. Wood properties under investigation included the chemical properties and morphological fiber characteristics (fiber dimensions and its derived properties). In the present study, data were analyzed using descriptive statistic, Analytic Hierarchy Process (AHP) and Pearson's correlation. Results showed that the chemical properties of E. pellita, i.e. the contents of ethanol-toluene extractives, hot water soluble extractives, holocellulose, alphacelullose, and lignin were $3.08{\pm}1.00%$, $1.41{\pm}0.38%$, $75.26{\pm}2.58%$, $49.02{\pm}2.88%$, and $29.49{\pm}1.86%$, respectively. The average values of wood fiber morphology were $1.02{\pm}0.08$ mm (fiber length), $13.25{\pm}1.64{\mu}m$ (fiber diameter), of $6.94{\pm}1.70{\mu}m$ (lumen diameter), $3.15{\pm}0.52{\mu}m$ (fiber wall thickness), $0.97{\pm}0.30$ (Runkel ratio), $0.57{\pm}0.10$ (Luce's shape factor), $78.21{\pm}10.34$ (slenderness ratio) and $130.91{\pm}33.77{\times}10^3{\mu}m^3$ (solids factor). The AHP scoring rank indicated that the best individuals were 28.4.3.28 (Kiriwo Utara), 12.1.5.28 (North Kiriwo), 19.11.5.45 (Serisa Village), 3.8.4.9 (South Kiriwo), and 6.6.3.15 (South Kiriwo). Pearson correlation analysis showed significant correlations between the levels of fiber length with alpha-cellulose content (r = 0.39) as well as the fiber length with ethanol-toluene extractive contents (r = -0.41).

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.217-222
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• 2003

This study was carried out to investigate the geotechnical characteristics and field application of soil mixed with waste lime. Waste lime used in this study is producted as a by-product in the manufacturing process of making Na$_2$CO$_3$from local chemical factory in Incheon. Currently about 320 milton tons of waste lime are accumulated and annually 100,000 tons are producted. In this study, feasible use of waste lime mixed with granited whathered soil, clay, crushed rock was invesigated through laboratory tests including specific gravity test, sieve analysis, hydrometer analysis, compaction test, CBR test. Field investigations were conducted on the road construction site in Incheon.

• 터널과지하공간
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• 제15권6호
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• pp.411-424
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• 2005

풍화작용은 심부에서 생성된 암석이 지표에서 파괴되고 변질되어 현재의 환경조건과 평형을 이루는 산물을 형성하는 과정이다. 본 연구에서는 국내에서 가장 분포면적이 넓은 화강암질암의 풍화단계별 시료를 채취하여 편광현미경관찰, X-선 회절분석, 전자현미경관찰, 화학분석, 물성시험등을 수행하였다. 실험결과에 의거하여 풍화에 의해 형성되는 2차광물, 특히 점토광물의 형성과정을 확인하였고, 풍화에 따른 암석의 공학적인 성질변화와 물성저하의 메카니즘을 규명하였다.

• 열처리공학회지
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• 제11권4호
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• pp.283-294
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• 1998

This paper presents an investigation why Mn-steel high pressure gas cylinders have been failed in service. The fractured cylinders have been collected to identify the reason of the failure using various methods. The undamaged, new cylinder has also been tested for the base data. We examined the chemical compositions and fracture facets as well as the mechanical properties of the vessels. The microstructural observations of the fractured regions of the cylinder did not indicate the noticeable defects which might cause the failure. The experiments of cylinders on the compositinal and mechanical tests showed that the cylinder was in good shape according the standards of gas pressure vessel. The morphological analysis of the fracture surfaces concluded that the origin of the failure was the local weak segments induced by the external impact to the cylinder, which result in a sudden, fast fracture.

• 한국철도학회논문집
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• 제3권1호
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• pp.34-41
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• 2000

The analysis of static and dynamic characteristics of reinforced roadbed materials was performed through model and laboratory tests. The strength characteristic of reinforced roadbed materials such as HMS-25 and soil were investigated through the unconfined axial compression test, the model soil box test and the combined resonant column and torsional shear test. The unconfined axial compression strength of HMS-25 shows a steady increasement in strength due to the chemical hardening reaction between HMS-25 and water. The result of model soil box test reveals that railroad roadbed of HMS-25 is better than that of soil in several aspects, such as, bearing capacity and settlement. The combined resonant column and torsional shear test result indicates that shear modulus of HMS-25 and soil increase with the power of 0.5 to the confining pressure and linear relationship to normalized shear modulus and damping ratio.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.272-274
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• 2008

A development of hydrazine decomposition catalyst for monopropellant thruster has been performed by Korea Aerospace Research Institute(KARI). The goal of this development is to product a catalyst showing the equivalent performance with space-proven catalysts. Catalyst production and physical/chemical analysis were conducted by Chonnam National University and the analysis result was compared with the result of other catalysts and our own specification. Using the developed prototype catalyst, short firing test was performed in a reactor to verify basic performance of catalyst. After the successful reactor test, hot firing tests were carried out in atmospheric and vacuum condition using 5N thruster to verify durability and safety of catalyst. In this paper, the catalyst development status will be presented.

• Environmental Analysis Health and Toxicology
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• 제31권
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• pp.11.1-11.6
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• 2016

Objectives A hazard assessment of di(2-ethylhexyl) phthalate (DEHP), a commonly used workplace chemical, was conducted in order to protect the occupational health of workers. A literature review, consisting of both domestic and international references, examined the chemical management system, working environment, level of exposure, and possible associated risks. This information may be utilized in the future to determine appropriate exposure levels in working environments. Methods Hazard assessment was performed using chemical hazard information obtained from international agencies, such as Organization for Economic Cooperation and Development-generated Screening Information Data Set and International Program on Chemical Safety. Information was obtained from surveys conducted by the Minister of Employment and Labor ("Survey on the work environment") and by the Ministry of Environment ("Survey on the circulation amount of chemicals"). Risk was determined according to exposure in workplaces and chemical hazard. Results In 229 workplaces over the country, 831 tons of DEHP have been used as plasticizers, insecticides, and ink solvent. Calculated 50% lethal dose values ranged from 14.2 to 50 g/kg, as determined via acute toxicity testing in rodents. Chronic carcinogenicity tests revealed cases of lung and liver degeneration, shrinkage of the testes, and liver cancer. The no-observed-adverse-effect level and the lowest-observed-adverse-effect level were determined to be 28.9 g/kg and 146.6 g/kg, respectively. The working environment assessment revealed the maximum exposure level to be $0.990mg/m^3$, as compared to the threshold exposure level of $5mg/m^3$. The relative risk of chronic toxicity and reproductive toxicity were 0.264 and 0.330, respectively, while the risk of carcinogenicity was 1.3, which is higher than the accepted safety value of one. Conclusions DEHP was identified as a carcinogen, and may be dangerous even at concentrations lower than the occupational exposure limit. Therefore, we suggest management of working environments, with exposure levels below $5mg/m^3$ and all workers utilizing local exhaust ventilation and respiratory protection when handling DEHP.

• 한국지반환경공학회 논문집
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• 제3권2호
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• pp.49-60
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• 2002

퇴적암의 풍화특성을 파악하기 위해서는 풍화과정을 지배하는 암석의 광물조성과 화학성분에 대한 연구가 필요하다. 본 논문에서는 풍화정도에 따른 퇴적암의 특성을 고찰하기 위해서 대구지역에 분포하고 있는 퇴적암을 채취하여 화학 및 광물성분 분석과 물리 및 역학특성 시험을 실시하였다. 화학적풍화지수와 감열감량, 흡수율과 일축압축강도, 풍화지수와 일축압축강도가 좋은 상관관계를 나타내었으며 모암에 함유된 $A_2O_3$, CaO, $Na_2O$, $K_2O$, MgO 등의 화학성분과 조장석(Albite, Ab), 백운모(Muscovite, Ms), 마그네타이트(Magenetite, Mt)등의 광물성분이 풍화와 밀접한 관계가 있었다. 이 시험결과를 토대로 하여 퇴적암에 적용할 수 있는 정량적인 풍화도판정법의 적용성을 제시하자고 하였다.