• Journal of the Korean Society for Nondestructive Testing
• /
• v.35 no.4
• /
• pp.239-244
• /
• 2015

Each biological tissue has endemic electrical characteristics owing to various differences such as those in cellular arrangement or organization form. The endemic electrical characteristics change when any biological change occurs. This work is a preliminary study surveying the changes in the electrical characteristics of biological tissue caused by radiation exposure. For protection aganinst radiation hazards, therefore the electrical characteristics of living tissue were evaluated after development of the automatic control measurement system using LabVIEW. No alteration of biological tissues was observed before and after measurement of the electrical characteristics, and the biblogical tissues exhibited similar patterns. Through repeated measurements using the impedance/gain-phase analyzer, the coefficient of variation was determined as within 10%. The reproducibility impedance phase difference in electrical characteristics of the biological tissue did not change, and the tissue had resistance. The absolute value of impedance decreased constantly in proportion to the frequency. It has become possible to understand the electrical characteristics of biological tissues through the measurements made possible by the use of the developed. automatic control system.

• Environmental Engineering Research
• /
• v.13 no.1
• /
• pp.33-40
• /
• 2008

Levels of arsenic in stream and reservoir waters affected by an abandoned gold mine were examined. The abandoned mine has been left without proper civil and remedial works preventing potential environmental hazards. Field and laboratory chemical analyses revealed that the stream waters downgradient from the mine area were severely contaminated with arsenic and furthermore the reservoir water, 2-3 km away from the mine, also contained substantial levels of As, far exceeding the Korean stream water standard. Relatively higher pH values (6.5-9.4) enhanced mobility of As and mainly sustained substantial As concentration in waters. Chemistries of the stream water, groundwater and reservoir water were dominated by two main factors including effects of mine effluent and anthropogenic agricultural activities. Considering that there has been a substantial As input to the reservoir and the reservoir water has been used for agricultural and domestic uses, immediate remedial works are essentially required.

• Biomedical Science Letters
• /
• v.23 no.3
• /
• pp.155-160
• /
• 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 Industrial and Engineering Chemistry
• /
• v.68
• /
• pp.79-86
• /
• 2018

Although the intrinsic characteristics of DNA molecules and carbon nanotubes (CNT) are well known, fabrication methods and physical characteristics of CNT-embedded DNA thin films are rarely investigated. We report the construction and characterization of carboxyl (-COOH) group-modified multi-walled carbon nanotube (MWCNT-COOH)-embedded DNA and cetyltrimethyl-ammonium chloride-modified DNA (DNA-CTMA) composite thin films. Here, we examine the structural, compositional, chemical, spectroscopic, and electrical characteristics of DNA and DNA-CTMA thin films consisting of various concentrations of MWCNT-COOH. The MWCNT-COOH-embedded DNA and DNA-CTMA composite thin films may offer a platform for developing novel optoelectronics, energy harvesting, and sensing applications in physical, chemical, and biological sciences.

• Journal of Food Hygiene and Safety
• /
• v.20 no.1
• /
• pp.36-42
• /
• 2005

The purpose of this study is to develope a HACCP model for Korean traditional cookies. Prerequisite program and HACCP plan were proposed and analyzed for Yugwa. After analysing hazards of raw material and manufacturing processes, CCP, CL and control methods were presented. Pathogenic microorganisms were detected at the Korean traditional cookies plant. It gave a clue that general sanitation control procedures should be implemented for safe traditional cookie products. Hazard analysis of raw materials and processing of Korean traditional cookies, determination of critical control points and critical limits at the plant lead to present a model of HACCP plan. Implementation of HACCP can be carried out using a HACCP model. Critical control point of Yugwa production were determined as frying process. Biological and chemical hazards were presented for CCP determination.

• Journal of the FoodService Safety
• /
• v.3 no.1
• /
• pp.38-44
• /
• 2022

This study investigated the microbiological hazards in the manufacturing processes of Naengmyeon. Sanitary indicative bacteria, such as aerobic plate counts and coliforms as well as pathogenic bacteria, were examined from raw materials, manufacturing processes, working area, 17 utensils and equipment. The aerobic plate counts for raw materials and arrowroot starch estimated as 0.77±0.68~5.02±0.28 and 5.02±0.28 log CFU/g, respectively. Coliforms were detected from wheat flour, buckwheat flour, and potato starch. Staphylococcus aureus was detected to be 0.61±1.06 log CFU/g in wheat flour and 0.20±0.35 log CFU/g in buckwheat flour. During the manufacturing process, aerobic plate counts for kneading process were 4.54±0.34 log CFU/g. But after the press out and heat process, contamination of aerobic plate counts and coliforms decreased and remained at a low level until the release process. Aerobic plate counts before washing disinfection of screw were 3.28±0.62 log CFU/100 cm², the level of which was high in utensils and equipment that had contact with employees or water. These results represent not only an important indicator for the hygienic level but also a scientific basis for analyzing biological hazards, which lead to the introduction of HACCP for the production of safe and hygienic cold noodles processed by manufacturers.

• Journal of Food Hygiene and Safety
• /
• v.30 no.1
• /
• pp.28-34
• /
• 2015

This study is to investigate microbiological hazards which can be used as fundamental data to adequately control leeks hazards and develop leeks GAP model for those who want to get GAP system. The microbiological investigations on cultivation environments (soil and water), crops (leeks), personal hygiene (workers' hands, clothes and gloves) and working tools (boxes) have been conducted for one year, so the period was classified under non-cultivation, cultivation, and post harvest. Total bacteria was detected from soil (4.0~6.7 log CFU/g), leeks (4.6~5.1 log CFU/g), hands (ND~3.3 log CFU/hand) and gloves ($ND{\sim}5.4\;log\;CFU/cm^2$) while nothing was detected from the other samples. The coliform contamination of leeks (4.8~5.0 log CFU/g) was more high than that of soil (3.9~4.2 log CFU/g). In case of foodborne pathogens, only B. cereus was detected at the level of 0.5~4.6 log CFU/g (or hand, $100cm^2$). Fungi was observed at the level of 2.1~3.8 log CFU/g (or hand, $100cm^2$) excepting water and some working tools. These results demonstrate that the contamination of leeks is comparatively higher than that of soil sample. The reason may be the cross-contamination by biological hazards presenting on soil. Therefore, it is necessary to properly control soil and fertilizer for safety against biological hazards.

• Journal of Food Hygiene and Safety
• /
• v.27 no.2
• /
• pp.152-160
• /
• 2012

The objective of this study was to analyze hazards for the growing stage of 6 tomato farms (A, B, C; soli farms, D, E, F; Nutriculture farms) located in Gyeongsangnam-do to establish the good agricultural practices (GAP). A total of 144 samples for analyzing hazards collected from cultivation environments (irrigation water, soil, nutrient solution, and air) and personal hygiene (hands, gloves, and cloths) were assessed for biological (sanitary indications and major food borne pathogens) and chemical hazards (heavy metals). Total bacteria, coliform, and fungi were detected at levels of 0.2-7.2, 0.0-6.1, and 0.0-5.4 log CFU/g, mL, hand or 100 $cm^2$, respectively. Escherichia coli were only detected in the soil sample from B farm. In case of pathogens, Bacillus cereus was detected at levels of 0.0-4.4 log CFU/(g, mL, hand or 100 $cm^2$), whereas Staphylococuus aureus, Listeria monocytogenes, E. coli O157, and Salmonella spp. were not detected in all samples. Heavy metals as a chemical hazard were detected in soil and irrigation water, but levels of them were lower than the permit limit. In conclusion, chemical hazard levels complied with GAP criteria, but biological hazards at the growing stage of tomato farms were confirmed. Therefore a proper management to prevent microbial contamination is needed.

• Korean Journal of Food Science and Technology
• /
• v.36 no.6
• /
• pp.1032-1040
• /
• 2004

Biological, physical, and chemical hazards in raw manufacturing processes of Saengshik, powdered raw grains and vegetables, were analyzed to identify critical control points (CCPs). In raw materials, total plate and coliform counts ranged 2.82-8.23 and $1.40-6.57\;{\log}_{10}\;CFU/g$, respectively. In final products, total plate counts, except for Lactobacillus spp., were $1.51-7.40\;{\log}_{10}\;CFU/g$. During processing steps, both total plate and coliform counts decreased after washing, whereas no changes were observed after freeze-drying. Physical hazards, such as contents of metal and other contaminants, and chemical hazards, such as moisture content, were assessed. Suggested CCPs for Saengshik were: washing process for controlling microbial contamination, freeze-drying process for controlling moisture content to prevent deterioration and growth of microorganisms, and pulverization process for controlling contamination of foreign substances such as metals. These results will provide guideline to apply HACCP system standards to this product.

• Journal of Food Hygiene and Safety
• /
• v.24 no.2
• /
• pp.162-168
• /
• 2009

This study was conducted the analysis of food safety incidents between January 1998 and October 2008 using media reports. Total number of food safety incident was 569 through the study period. The average of food safety incident per year and month was 51.7and 4.9, respectively. The top 10 food types involved in the lists of food safety incidents were as follows; marine products, meat and meat products, confectionaries, beverages, special nutritional food, teas, noodles, soy and bean paste sauces, and milk and milk products etc. The top 10 single foods also were as follows; ready-to eats, meat, confectionary, health support foods, steeping tea, infant formula, meat products, ginseng products, foods for body weight control etc. Of the total 569 incidents, 247 (43.4%) were related with chemical hazards involving pesticide, food additives etc, biological hazards were 126 (22.1 %), and physical hazards were 97 (17.0%) incidents. In analysis stage in the food chain at which breakdown in food safety occurred, primary production were the most common stage with 364 (64%) incidents, and incidents at the manufacture handling and distribution stages were with 151 (26.5%), and 44 (7.7%), respectively. The results of this study can be used as a better data for risk analysis or food safety strategies.