• Journal of Food Hygiene and Safety
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• v.8 no.1
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• pp.17-23
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• 1993

In an attempt to quantitate and qualitate residual antibiotics and antibacterial agents n meat simultaneously, we studied a gas chromatogrphy-mass spectrometry (GC/MS) analysis. For a simultaneous analysis of macrolide antibiotics such as erythromycin and tylosin in meat, the homogenization with MeOH, defatting with n-hexane, extraction with CHCl3, elution with CHCl3 : MeOH=2:1 from Sep-Pak silica cartridge, acid gydrolysis, back extraction with CHCl3, and quantitation by selected ion monitoring(SIM) mode after trimethylsilyl derivatization were performed. The recoveries of erythromycin and tylosin (CV,%) at 10 ppm fortification level were 90.59(4.89) and 45.91(0.20) , and the detection limits of those were 0.02 and 2.0 $\mu\textrm{g}$/g beef, respectively. From these results, the developed analytical method using GC/MS-SIM mode allows excellent detection and quantitation of residual macrolide antibiotics in meats, using complementary method with bio-assay.

• Journal of the Korean Vacuum Society
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• v.17 no.1
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• pp.1-8
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• 2008

We analyzed the characteristics of water leakage from cooling components of the storage ring in the Pohang Light Source. The water leaks led localized pressure bumps and abnormal pressure changes. The leakage also changed the residual gas compositions depending not only on the position between leakage place to gas analyzer but also on on/off switching of ion pump and electron beam. We found that the residual gas analysis of $CH_4$, CO, NO was useful in determining water leaks.

• Journal of Environmental Science International
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• v.22 no.9
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• pp.1105-1113
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• 2013

This paper attempted to estimate the emissions of HFC-134a from scrap truck as a result of measuring the residual quantities of HFC-134a in air conditioner of scrap truck. We measured the residual amounts in the scrap truck of 138 by applying commercial recover for refrigerants. The average residual rate(disposal-phase emission factor) is reported to be $44.3{\pm}3.3%$ within a confidence interval of 95%. Recent year model trucks exhibit the higher residual rates. Little variation, however, is observed in regard to vehicle size. The HFC-134a emission quantity from scrap truck in 2011 is estimated to be 55,908 $tCO_2$-eq that demonstrates 21.4% increase to compare with that in 2007. As the numbers of truck have increased dramatically during the last two decades, the emissions of HFC-134a from scrap truck would increase sharply in the next coming years. HFC-134a is a very high GWP greenhouse gas. therefore have to reduce the emissions from the scrap truck and need to find ways to recycle. The chemical compositions of refrigerants from scrap truck are quite similar to those of new refrigerants, suggesting that the refrigerants from scrap truck could be reused as refrigerant.

• Journal of Korean Society for Quality Management
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• v.45 no.4
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• pp.649-664
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• 2017

Purpose: This paper introduces the technology of prognostics for Industry 4.0 and presents its application procedure for fitness-for-service assessment of natural gas pipelines according to ISO 13374 framework. Methods: Combining data-driven approach with pipe failure models, we present a hybrid scheme for the gas pipeline prognostics. The probability of pipe failure is obtained by using the PCORRC burst pressure model and First Order Second Moment (FOSM) method. A fuzzy inference system is also employed to accommodate uncertainty due to corrosion growth and defect occurrence. Results: With a modified field dataset, the probability of failure on the pipeline is calculated. Then, its residual useful life (RUL) is predicted according to ISO 16708 standard. As a result, the fitness-for-service of the test pipeline is well-confirmed. Conclusion: The framework described in ISO 13374 is applicable to the RUL prediction and the fitness-for-service assessment for gas pipelines. Therefore, the technology of prognostics is helpful for safe and efficient management of gas pipelines in Industry 4.0.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.1
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• pp.28-36
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• 2001

In this study, a zero-dimensional two zone model is developed to investigate the effects of valve overlap period and valve lift on combustion and gas exchange process in SI engine. The simulation results show that the predicted data has good agreements with experimental ones. The useful information of combustion and gas exchange process such as residual gas fraction, cylinder pressure, mass flow rate and volumetric efficiency can be obtained and the effects of engine variables on combustion processes and performances can be evaluated.

• Journal of Preventive Medicine and Public Health
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• v.3 no.1
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• pp.17-22
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• 1970

By using Siregnost FD 91 body plethysmograph, we measured thoracic gas volume (TGVe) at end of expiration in 19 healthy subjects aged 20-43 years in order to compare with functional residual capacity (FRC) measured by closed circuit method. The results obtained were as follows 1. Mean values of TGVe and FRC were $3.395{\pm}0.5851{\ell},\;and\;3.393{\pm}0.618{\ell}$, respectively. 2. A advantage of the body phethysmographic method for measuring thoracic gas volume was that it were rapid, safe, and easy to perform, requires no gas sample for chemical analysis, and measured TGVe several times.

• Journal of Korea Society of Industrial Information Systems
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• v.20 no.4
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• pp.25-37
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• 2015

The early studies indicated that the firm with monopoly power is likely to engage in X-inefficiency such as a managerial slack. The reflection of the X-inefficiency theory has led to the issue that the public sector may be more inefficient than the private sector. In Korea like other many countries the electricity gas water service which can be considered as natural monopoly have been provided mostly by the public sector. In order to provide the empirical evidence to the argument that the public sector may be more inefficient than the private sector this paper estimated the four types of Solow residual which is called the total factor productivity in the electricity gas water service industry with the associated empirical model and compared its productivity with one in the manufacturing industry. The empirical results do not support the argument that the public sector may be more inefficient or less productive than the private sector.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.6 s.165
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• pp.943-951
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• 1999

The welded structure unnecessarily remains residual stress due to the very high heating of local region and lastly cooling. The residual stress sometimes causes fracture initiation of welded structures. In this paper, distribution and magnitude of tensile and compressive residual stresses in the TIG(Tungsten Inert Gas) welded aluminum alloy such as Al5083-H112 are measured by using the hole-drilling method. Furthermore, the effects of residual stresses in the TIG welded aluminum CCT(Center Crack Tension) and SEN(Single Edge Notched) Specimens on the fatigue crack propagation behavior are analyzed. The fatigue cracks initiated at residual stresses region are influnced by tensile and compressive residual stresses. However, the effects are found to be released fast for both cases according to the cyclic loads and extension of crack length.

• Journal of Welding and Joining
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• v.33 no.1
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• pp.72-79
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• 2015

Evaluation of fracture toughness of welded structures has a significant influence on the structural design. However the residual stresses is redistributed while the welded structures is cut for preparing specimens. This study investigated an effect of the welding residual stress redistribution on the impact absorption energy of Charpy specimen. SA516Gr70 steel plate by at the flux cored arc welding (FCAW) and gas tungsten arc welding(GTAW) was cutting. Specimens for Charpy impact testing were taken from the welded plate. Two material removal mechanisms (wire cutting and water jet) were used to make the specimens. Welding residual stress and redistribution residual stress were measured using the XRD (X-Ray Diffraction) method. The amount of redistribution of residual stress depends on the different material removal mechanism. Redistribution of residual stress of reduced the impact absorption energy by 15%.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.3
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• pp.406-413
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• 2014

A study was conducted to compare the effect of halal slaughter without stunning and gas stun killing followed by bleeding on residual blood content and storage stability of rabbit meat. Eighty male New Zealand white rabbits were divided into two groups of 40 animals each and subjected to either halal slaughter without stunning (HS) or gas stun-kill (GK). The volume of blood lost during exsanguination was measured. Residual blood was further quantified by determination of haemoglobin content in Longissimus lumborum (LL) muscle. Storage stability of the meat was evaluated by microbiological analysis and measuring lipid oxidation in terms of thiobarbituric acid reactive substances (TBARS). HS resulted in significantly higher blood loss than GK. HS had significantly lower residual haemoglobin in LL muscle compared to GK. Slaughter method had no effect on rabbit meat lipid oxidation at 0, 1, and 3 d postmortem. However, at 5 and 8 days of storage at $4^{\circ}C$, significant differences (p<0.05) were found, with meat from the GK group exhibiting significantly higher levels of MDA than that from HS. At day 3, greater growth of Pseudomonas aeroginosa and E. coli were observed in the GK group (p<0.05) with B. thermosphacta and total aerobic counts remained unaffected by slaughter method. At days 5 and 7 postmortem, bacterial counts for all tested microbes were affected by slaughter method, with GK exhibiting significantly higher growth than HS. It can be concluded that slaughter method can affect keeping quality of rabbit meat, and HS may be a favourable option compared to GK due to high bleed out.