• Molecules and Cells
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• v.45 no.7
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• pp.502-511
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• 2022

Bacterial volatile compounds (BVCs) exert beneficial effects on plant protection both directly and indirectly. Although BVCs have been detected in vitro, their detection in situ remains challenging. The purpose of this study was to investigate the possibility of BVCs detection under in situ condition and estimate the potentials of in situ BVC to plants at below detection limit. We developed a method for detecting BVCs released by the soil bacteria Bacillus velezensis strain GB03 and Streptomyces griseus strain S4-7 in situ using solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS). Additionally, we evaluated the BVC detection limit in the rhizosphere and induction of systemic immune response in tomato plants grown in the greenhouse. Two signature BVCs, 2-nonanone and caryolan-1-ol, of GB03 and S4-7 respectively were successfully detected using the soil-vial system. However, these BVCs could not be detected in the rhizosphere pretreated with strains GB03 and S4-7. The detection limit of 2-nonanone in the tomato rhizosphere was 1 µM. Unexpectedly, drench application of 2-nonanone at 10 nM concentration, which is below its detection limit, protected tomato seedlings against Pseudomonas syringae pv. tomato. Our finding highlights that BVCs, including 2-nonanone, released by a soil bacterium are functional even when present at a concentration below the detection limit of SPME-GC-MS.

• Journal of Industrial Technology
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• v.18
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• pp.203-208
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• 1998

Fatigue tests were performed to examine the 4 parameter method for specimens prepared by various heat treatment which resulted in different mechanical properties. Obtained main results are as follows. (1) Samples treated by austempering did not show the expected improvement of fatigue limit although hardness and strength increased. This is attributed to the fact that defect sensitivities of materials increase as increasing of hardness and tensile strength, it is also shown that the graphites acting as stress concentration place become larger by austempering heat treatment than by normal annealing. (2) It is very reasonable to predict the fatigue limit of ductile irons with 4 parameter method based on ${\sigma}_{TS}$, $H_v$, ${\Delta}K_{th}$ and ${\sqrt{area}}_{max}$. (3) The half-austempering treatment appeared to be more useful than the full-austempering method to improve the fatigue limit in the spheroidal graphite cast iron with multi defective material.

• Advances in Computational Design
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• v.8 no.3
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• pp.191-217
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• 2023

The objective of this study was to evaluate the foundation structure of a 3.6-MW wind turbine generator (WTG) installed offshore in Western Korea. The ultimate limit state (ULS) and fatigue limit state (FLS) of the multi-pile steel foundation (MSF) installed at the Saemangeum offshore wind farm were structurally investigated using the finite element (FE) software, ANSYS Workbench 19.0. According to the ULS analysis, no plastic deformation was found in any of the components constituting the substructure. At the same time, the maximal stress value reached the calculation limit of 335 MPa. According to the FLS results, the stress concentration factor (SCF) ranged from 1.00 to 1.88 in all components. The results of this study can be applied to determine the optimal design for MSFs.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.2
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• pp.123-136
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• 2013

Objectives: This paper was prepapred to report airborne asbestos fiber concentrations in asbestos textile, brake-lining, commutator, and building materials manufacturing industries, and some other asbestos related industries in Korea from 1994 to 2006. Methods: Airborne asbestos data that have been sampled and analyzed in the above industries during 1994-2006 were collected. These data were reviewed to scrutinize the qualified data based on the records such as sampling and analyzed method and quality control procedures. All asbestos data were generated using the National Institute for Occupational Safety & Health (NIOSH) Method 7400. Results: Average concentration of asbestos fiber was 2.14 fibers/cc(0.02-15.6 fibers/cc) in the asbestos textile industry, 0.26 fibers/cc(0.01-1.01 fibers/cc) in the building-materials industry, 0.15 fibers/cc(0.01-0.93 fibers/cc) in the brake-lining manufacturing industry, and 0.14 fibers/cc(0.03-1.36 fibers/cc) in the commutator producing industry. For these industries, the percentage of samples of which asbestos fiber concentrations above the limit of exposure(0.1 fibers/cc) was 97.6% in the asbestos textile industry, 62.3% in the building-materials industry, 53.5% in the brake-lining manufacturing industry, and 34.3% in the commutator producing industry. Asbestos fiber concentration was below the limit of exposure in the gasket producing, petrochemistry, musical instrument producing industries, and the brake-lining exchange operations. Conclusions: Airborne asbestos fiber level in the asbestos textile, brake-lining producing, commutator and building-material producing industries was above the limit of exposure, but in the gasket producing, petrochemistry, musical instrument producing industries and the brake-lining exchange operations were below the limit of exposure.

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.2
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• pp.25-30
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• 2021

This study investigated how the indicators of quality control are improved by proficiency in the measurement of phosphate concentration. In addition, analysis equipments were to be compared to see if there were any differences in measurements depending on the type of analysis device. In order to find out the effect of the proficiency of the analyst on the analysis results, three analysts measured phosphate concentration seven times in accordance with the Korean water pollution test standards, and met the quality control indices if repeated more than five times. The limit of quantification for phosphate was calculated at 0.02 mg/L. If the analysis devices are different, the absorbance and concentration of the samples near the limit of quantification are statistically significant difference.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.3 no.1
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• pp.68-80
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• 1996

Long-term hemodialysis(HD) patients manifest various signs of protein and caloric malutrition due to poor intake of nutrients and other causes. Poor nutritional status increases the mortality and morbidity rates in HD patients. Thus, mataintnance of adequate nutritional status has been a major task in taking care of patients receiving HD. This study was to evaluate the nutritional status of HD patients and to clarify the degree of nutritional deficit based on usual dietary intake, anthropometric and biochemical indicators. Sixty HD patients comprised a HD group, while the control group consisted of 60 healthy adults whose age and sex matched those of the HD group. Nutritional status was evaluated by dietrary intake using instant nutritional scale, anthropometric measures, serum protein concentrations and the number of lymphocytes. The data were analyzed by using Chi-square test and unpaired t-test. The results are as follows. 1. Regarding usual dietary intake of HD group. 1) Estimated caloric intake was significantly lower than the recommended daily allowance(RDA) and among them, 35% were taking calories less than 85% of the RDA. 2) Estimated protein intake was significantly higher than the RDA and among them 40% were taking protein more than 115% of the RDA. 3) Estimated fat intake was lower than the RDA. 4) Vitamin A, B, $B_1,\;B_2$, C and niacin in take was lower than the RDA respectively. 5) Estimated ferrous intake was within the normal limit the RDA while estimated calcium intake was higher than the RDA. 6) Both calorie and protein intake were higher for the 10 patients who had been under continuous ambulatory peritoneal dialysis than for the patients under HD from the beginning. 2. Regarding anthropometric measures : 1) Body mass index(BMI), midarm circumference(MAC), and triceps skinfold thickness(TSF) were lower in the HD group than in the control group. 2) Among HD group, 47.1% were within the normal limit of BMI, while 86.7% were within the same limit in the control group. 3) Among HD group, 35.0% were within the normal limit of MAC, while 83.3% were within the same limit in the control group. 4) Among HD group, only 8.3% were normal, 30.3% were mild deficit status of TSF, while 50% were normal and 48.3% were mild deficit status in the control group. 3. Regarding biochemical laboratory tests 1) Albumin, transferrin concentrations and the number of lymphocytes were lower in HD group than in the control group. 2) Among HD group, 98.3% were within the normal limit of albumin concentration and all were within the same limit in the control group. 3) Among HD group, only 11.7% were within the normal limit of transferrin concentration, while 81.7% were within the same limit in the control group. 4) Among HD group, 25% were within the normal limit, while 93.3% were within the same limit in the control group. The above findings suggest that HD patients were in nutritional deficit status. Adequate diet therapy and periodical evaluation of the nutritional status in HD patients are needed. Accordingly, it turned out that anthropometric measures were very reliable parameters and easy to use to evaluate nutritional status. So nurses are encouraged to adopt anthropometric measures to examine nutritional deficit status of HD patients.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.2
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• pp.145-157
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• 1999

Wood dust is created when machines are used to cut or shape wood materials. Industries of high risk of wood dust exposure are sawmills, dimension mills, furniture industries, and carpenters, etc. Health effects associated with wood dust exposure includes dermatitis, allergic respiratory effects and cancer. Health effects of wood dus t are mainly depend on the concentration, dust size and exposure time. This study were carried out to evaluate the concentration and particle size distribution of wood dust during working processes. The subjects of this study were 53 workers exposed to wood dust in 7 furniture factories and 5 musical instruments, and 5 sawmill factories. The average total wood dust concentrations measured by personal cascade impactor were $1.82{\pm}2.31mg/m^3$ in primary manufacture, $3.59{\pm}1.72mg/m^3$ in s econdary manufacture, $5.09{\pm}1.46mg/m^3$ in sanding operation. Mass median diameters of hardwoods dust were $3.36{\mu}m$ in primary manufacture, $4.25{\mu}m$ in secondary manufacture, $4.21{\mu}m$ in sanding operation. softwoods dust were $3.39{\mu}m$ in primary manufacture, $4.34{\mu}m$ in secondary manufacture. Particle size distributions showed a nearly the same pattern in each working processes. The sample concentration of all hardwood dust exceeded the Threshold Limit Value(TLV) and 20.8% of the softwood dust exceeded the Threshold Limit Value. The range of size distribution were $0.5-10{\mu}m$ in the soft and hardwood dust. The respirable dust of soft and hardwood took up 59% and above. Therefore new threshold limit value for wood dust should be needed in Korea. Also, it should be done for various studies on health effects related to occupational exposure of wood dust.

• Journal of Radiation Protection and Research
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• v.38 no.4
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• pp.234-236
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• 2013

Some of radioactive contamination is unavoidable in the facilities using the unsealed radioactive material. The primary purpose of radioactive contamination control in the workplace with contamination concern is the effects from the potential intake of radioactive material into the body. This paper provides procedures to estimate the level of internal exposure for the worker based on the conservative assumptions and simple calculations. They consist of two processes; to calculate air concentration of radioactive material and annual intake by inhalation with contaminated air and to compare each of them to Derived Air Concentration and Annual Limit on Intake mentioned in the related notification. The procedures are applicable to make a decision on practical requirements for monitoring air contamination and internal exposure of worker as follows; needs for measurement of air contamination and internal exposure and acquisition of information on the design of the ventilation system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.5
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• pp.1220-1226
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• 2007

As the industry of 21C has been developed, the gas industry has grown and it has not only the convenience but also the riskiness fer using. Especially, the energy and environment problems have been getting serious after the modern industry revolution. Therefore, the demand of gas as an eco-friendly energy source is getting increased. With the demand of gas, the installation and use of gas boiler is also increased, so human life injury by the waste gas(CO) of boiler goes on increasing every year. Therefore, we want to find out the harm to human body through the study on the concentration of CO by the length of the curved exhaust tube of boiler. The allowable concentration of CO is 50ppm. The length of the one-meter-three-curved tube after three minutes is applicable to 50ppm of the threshold limit values of CO. Also, five meters exceed the threshold limit values of CO after five minutes. Strangely, the concentration of CO is under the threshold limit values from two to four meters.

• Journal of the Korean Institute of Gas
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• v.11 no.2 s.35
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• pp.65-70
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• 2007

The explosion phenomenon and hazard estimate of LP gas, the study was examined into variation of oxygen concentration and LP gas concentration. As the result of experiment, the lower explosive limit was decreased as the increased at concentration of LP gas and 21% of oxygen concentration. Minimum oxygen concentration was 14.5%. 12.0%, 11.5% at 1.0, 1.5 and 2.0 bar respectively. And maximum explosion pressure was increased for $6.46kg/cm^2,\;9.41kg/cm^2\;and\;13.49kg/cm^2$ according to increased of pressure. The speed of flame propagation was increased as the higher with initial pressure of LP gas.