• Journal of Korean Society of Water and Wastewater
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• v.33 no.6
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• pp.457-467
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• 2019

Because non-point source pollution is very closely related to hydrological characteristics, its importance is highly emphasized nowadays along with accelerating climate change. Especially for Korea, the non-point source pollution and its control are entirely depending on runoff, precipitation, drainage, land use or development, based on geographical and topographical reasons of Korea. Many studies reported the physical (e.g., apparatus- and natural-type facilities, etc.) and chemical methods (e.g., organic and inorganic coagulants, etc.) of controling non-point pollutant source pollution, however, those are needed to be reconsidered along with climate change causing the unexpected patterns and amounts of precipitation and strengthen complexity of social community. The objectives of this study are to assess recent situations of non-point source pollution in Korea and its control means and to introduce possible effective ways of non-point source pollution against climate change in near future.

• Food Science of Animal Resources
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• v.27 no.1
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• pp.8-15
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• 2007

Conjugated linoleic acid (CLA) was chemically synthesized using the alkaline isomerization method of com oil. CLA-TG was synthesized by reaction with sodium methoxide. Five different treatments were devised based on differences in the amount of CLA-TG added into the pressed han. for controls, 10% of pork back fat among the total component was only added without any CLA-TG. For the first treatment, 5% of CLA-TG among the lard component added into the press ham was replaced. For the 2nd, 3rd and 4th treatments, 10%, 15% and 20% of CLA-TG was respectively replaced. Pressed ham manufactured using CLA-TG was vacuum packaged and then stored for 1, 7, 14, 21 and 28 days at $4^{\circ}C$. Samples were analyzed for chemical composition, physico-chemical properties (pH, color), and texture characteristics. Typical chemical composition characteristics (moisture, crude protein, crude fat) were not significantly different between controls and CLA-TG treatment groups. Crude fat content of CLA-TG treatment groups was significantly lower than that of controls (p<0.05). pH values of controls was higher than that of CLA-TG treatment groups. The pH of control and CLA-TG treatment groups increased significantly as the storage period increased (p<0.05). Meat color (CIE $L^*,\;b^*$) of CLA-TG treatment groups was higher than that of controls. $a^*$ values were decreased by replacement of CLA-TG, but appeared to be unaffected by storage length. There was no significant difference in texture between controls and CLA-TG treatment groups. Based on these findings, we conclude that the physico-chemical properties and texture characteristics of manufactured pressed ham were not affected by CLA-TG addition. Also, our results indicate that high-quality pressed ham can be manufactured with CLA accumulation.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.3
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• pp.378-384
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• 2007

Three microorganisms and one chemical preservative were tested for their effects on the fermentation and aerobic stability of whole-crop wheat, sorghum and maize silages. Wheat at the early dough stage, sorghum at the late milk stage and maize at the one-third milk line stage were harvested and ensiled in 1.5-l anaerobic jars untreated or after the following treatments: control (no additives); Lactobacillus plantarum (LP) at $1.0{\times}10^6$ colony-forming units (CFU)/g of fresh forage; L. buchneri (LB) at $1.0{\times}10^6$ CFU/g; Propionibacterium acidipropionici (PA) at $1.0{\times}10^6$ CFU/g; and a formic acid-based preservative (FAP) at 3 ml/kg of fresh forage weight. Three jars per treatment were sampled on d 90 after ensiling, for chemical and microbiological analysis. At the end of the ensiling period, 90 d, the silages were subjected to an aerobic stability test lasting 5 d. In this test, $CO_2$ produced during aerobic exposure was measured along with chemical and microbiological parameters which serve as spoilage indicators. The silages inoculated with LP had higher concentration of lactic acid compared with the controls and the other treated silages (p<0.05). The controls and LP-inoculated silages spoiled upon aerobic exposure faster than LB, PA and FAP-treated silages. The controls and LP-inoculated silages spoiled upon aerobic exposure faster than LB, PA and FAP-treated silages due to more $CO_2$ production (p<0.05) in these two groups and development of yeasts unlike the other groups. In the experiment, the silages treated with LB, PA and FAP were stable under aerobic conditions. However, the numbers of yeasts was higher in the LP-inoculated wheat, sorghum and maize silages compared with the LB, PA and FAP-treated silages. The LB, PA and FAP improved the aerobic stability of the silages by causing more extensive heterolactic fermentation that resulted in the silages with high levels of acetic and propionic acid. The use of LB, PA and FAP as silage additives can improve the aerobic stability of whole-crop wheat, sorghum and maize silages by inhibition of yeast activity.

• Journal of The Korean Digital Architecture Interior Association
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• v.12 no.4
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• pp.87-95
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• 2012

Autoclaved lightweight concrete (ALC), also known as autoclaved aerated concrete (AAC), is a lightweight, precast building material that simultaneously provides structure, insulation. ALC is a unique building material. Because of its cellular nature, it is lightweight, self-insulating, as well as sound and fireproof. ALC products include blocks, wall panels, floor and roof panels, and lintels. Recently, the use of ALC has became increasingly popular. However, ALC have high water absorption, low compressive strength and popout the origin of the low surface strength in its properties. Thus, this study is to improve the fundamental strength by controls of increasing of admixtures and chemical reactants. Admixtures make use of meta kaolin and silica fume, chemical reactants make use of sodium silicate and sodium hydroxide. From the test result, the ALC using admixtures and chemical reactants have a good fundamental properties compared with plain ALC. These good fundamental properties is caused by the admixtures and chemical reactants of ALC by the reason of the micro filling effect and chemical binding of C-S-H gel, tobermolite and quartz.

• Biomedical Science Letters
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• v.23 no.3
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• pp.155-160
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• 2017

Biomedical laboratory is full of risks. Risk could be biological, chemical, radioactive, mechanical, physical, fire and electrical. All possible risks need to be identified, evaluated and controlled. A risk management system must be in place to prevent accident or loss of lives and to improve overall workplace safety and productivity. Safety in laboratory is a combination of appropriate risk management system, engineering controls and technical facilities, administrative controls and safety procedures and practices. Laboratory safety culture must be developed so that exposure to hazards for laboratory personnel, community and environment will be minimized or eliminated. In this review, importance of safety in a biomedical laboratory and risk management will be discussed.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.2
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• pp.304-309
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• 2013

In chemical, medical or biology laboratories Fume Hoods are basic facilities which can protect researchers from dangerous gas as blowing the contaminated air outside. After the air inside the laboratory room is sucked into the hume hood, then, it is blew out by a fan rotated by an AC induction motor. In addition, a damper controls the inside opening of a duct, which the air flows through. The face velocity, air velocity through the front door, have to be kept constant as the set value even though the opening of the door is varied. However, conventional fume hood used to be operated by operator's manual switches. So that, in this paper an automatic control system is developed which controls the face velocity by adjusting the rotating speed of the blow motor and the opening of the damper. Experiments show that this developed system can be used at such laboratories.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.591-596
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• 2001

Micron-size mechanical devices are becoming more prevalent, both in commercial applications and in scientific inquiry. Within the last decade, a dramatic increase in research activities has taken place, mostly due to the rapidly expanding growth of applications in areas of MEMS(Micro-Electro-Mechanical Systems), bioengineering, chemical systems, and advanced energy systems. In this study, we have described the effects of vortex viscosity variation on the flowfields in a micro-slot between rotating surfaces of revolution using a micropolar fluid theory. In order to solve this problem, we have used boundary layer equations and applied non-zero values of the microrotation vector on the wall. The results are compared with the corresponding flow problems for Newtonian fluid. Results show that the coefficient $\delta$ controls the main part of velocity ${\upsilon}_x$ and the coefficient M controls the main part of microrotation component ${\Omega}_{\theta}$.

• Proceedings of the Ginseng society Conference
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• 1993.09a
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• pp.164-170
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• 1993

Panax ginseng has been reported to protect animals or to help them recover from physical, chemical, or biological stress. The antistress effects of ginseng were evaluated through the measurement of adrenal ascorbic acid, rectal temperature, and plasma level of glucose. lipids and corticosterone. During the treadmill experiments of the antifatigue study, the groups of rats receiving P. ginseng or P. quinquefolius extracts were consistently found to leave fewer fecal boli on the wheel compared with controls. This phenomenon may be due to the reported antistress effects of ginseng. Another possibility could be that the Panax species examined produced anticholinergic effects which in turn inhibited the production of fecal boli. After an anticholinergic study. employing physostigmine and atropine as controls, anticholinergic effect was found not essential for the decrease of fecal boli number left on the wheels during antifatigue studies. The results were consistent with the antistress activity reported previously. Even though the active constituents responsible for the antistress effects of ginseng remained to be determined, the fecal boli counts for stressed rats can be employed as a new protocol for evaluating the antistress effects of ginseng.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4441-4444
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• 2012

Background: Polymorphisms of the Taq I gene have been associated with prostate cancer risk. Methods:We applied a fixed-effects model to combine odds ratios (ORs) and 95% confidence intervals (95% CI). The Egger's test was carried out to evaluate potential publication bias. Results: A total of 10 case-control studies enrolling 1,141 prostate cancer patients and 1,685 controls were included in this meta-analysis. Compared with the T allele, the OR for the C allele was 0.81 (0.70-0.94). The ORs for CT and CC+CT genotypes were 0.86 (0.74-1.01) and 0.84 (0.73-0.97) compared to wide type genotype (homozygote TT). Conclusions: The present meta-analysis suggests that the TF gene Taq I polymorphism may reduce the prostate cancer risk in Asian populations.

• Safety and Health at Work
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• v.10 no.3
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• pp.355-361
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• 2019

Background: Painters in the automotive sector are routinely exposed to volatile organic solvents, and the levels vary depending on the occupational health and safety controls enforced at the companies. This study investigates the levels of exposure to organic vapors and the existence of controls in the formal economy sector in southern Colombia. Methods: This is an exploratory study of an observational and descriptive character. An analysis of solvents is conducted via the personal sampling of painters and the analysis of samples using the National Institute for Occupational Safety and Health 1501 method. The amount of solvents analyzed varied according to the budget allocated by the companies. The person in charge of the occupational safety and health management system was interviewed to learn about the exposure controls implemented at the companies. Results: A medium exposure risk for toluene was found in one company. Another presented medium risk for carbon tetrachloride, xylene, ethylbenzene, and n-butanol. The others showed low risk of exposure and that the controls implemented were not sufficient or efficient. Conclusion: These results shed light on the working conditions of these tradespeople. The permissible limits established by Colombian regulations for the evaluated chemical contaminants were not exceeded. However, there were contaminants that exceeded the limits of action. The analysis of findings made it possible to propose improvements in occupational safety and health management systems to allow the optimization of working conditions for painters, prevent the occurrence of occupational diseases, and reduce costs to the country's health system.