• Journal of Environmental Health Sciences
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• v.35 no.6
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• pp.510-516
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• 2009

Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) were measured in soil samples of Ansung in Kyonggi-province to investigate concentration distribution of PBDEs and PCBs. The 10 soil samples were collected using a stainless steel hand-held corer that was cleaned before and after each sample using hexane. Total concentration of PBDE and PCBs were 2,205.3 and 348.1 pg/g dry weight (DW) in soil sample, respectively. BDE-209 showed as the most abundant congener in soil samples which was related to imported amount and usage amount of deca-BDE technical mixture in Korea. Also, BDE-99, BDE-47, BDE-100 deposition in soil sample was higher than other congeners and was related to the imported and usage amount reported for penta-BDE technical mixture in Korea. Correlation coefficient between PBDE contribution and technical mixture formulation (Bromokal 70-5DE) were significant (r=0.91, p<0.01) which suggests the influence of sources in this technical mixtures.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.3
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• pp.191-195
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• 2016

This study was carried out to find a new corn cultivar with multiple tillers that is suitable for forage. Materials were developed at the Corn Breeding Laboratory of Chungnam National University. A total of 3,650 accessions were collected domestically and from other countries, including China. Among them, 16 CNU inbreds, tillering and non-tillering, were compared to each other in terms of stem heigh, number of tillers, fresh weight, and dry weight per plant. Of these surveyed traits, the stem heigh at tasseling stage was 140~190 cm and number of tillers per plant ranged from two to four. Fresh weight and dry weight of these lines were higher in the tillered than in the non-tillered sample.

• Journal of Korean society of Dental Hygiene
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• v.12 no.1
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• pp.1-15
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• 2012

Objectives : The purpose of this study was to examine the effect between job stress in jobholders and xerostomia. Methods : 250 jobholders living in Jecheon city were the subjects of this questionnaire. The questionnaire was made up of three contents and 37 items: general characteristic(13), job stress(14), degree & behavior of xerostomia(10). The data were analyzed by two-sample t-test, one-way ANOVA to examine the subjects general characteristics, job stress and degree of xerostomia and were analyzed by Chi-square test to examine the subjects general characteristics, job stress and behavior of xerostomia. Results : Only 215 jobholders were evaluated due to inadequate responses. The results were as follow. 1. As general characteristic of jobholder, male(83.7%) were more than women(16.3%), 30~39 year-old(47%) in age variable, university graduation(63.7%) in the last educational background variable, 2~3 million won(31.2%) in the month average income variable, 1~5 year(33.5%) in tour of duty variable, non-smoker(47.9%) in smoking variable were most. Married(58.6%) were more than unmarried(39.5%). Alcoholic(69.8%) were more than non-alcoholic(30.2%). 2. As classification of job stress, high strain group was 28.4%, active group was 26%, low strain group was 24.2%, passive group was 21.4%. 3. Analysis of effect between general characteristic and degree & behavior of xerostomia showed smoker were statistical significantly higher than non-smoker on 'dry eat', 'Am-sal', 'Night awake', 'Slip-liq'and 'Gumcandy'(p<0.05) and showed alcoholic were statistical significantly higher than non-alcoholic on 'Dry PM', 'Night awake, $H_2O$-bed'(p<0.05). 4. Analysis of effect between job stress and degree & behavior of xerostomia showed hight strain group were statistical significantly higher than low strain group on 'Dry PM', 'Dry-day', 'Am-sal', 'Eff-life'and 'Night awake'(p<0.05). Conclusions : As high strain group were higher than other groups on degree & behavior of xerostomia, stress would be factor that have an effect on xerostomia. Thus consider and management of stress is necessary for diagnosis and treatment of xerostomia.

• Journal of Powder Materials
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• v.28 no.6
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• pp.462-469
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• 2021

Tin/graphite composites are prepared as anode materials for Li-ion batteries using a dry ball-milling process. The main experimental variables in this work are the ball milling time (0-8 h) and composition ratio (tin:graphite=5:95, 15:85, and 30:70 w/w) of graphite and tin powder. For comparison, a tin/graphite composite is prepared using wet ball milling. The morphology and structure of the different tin/graphite composites are investigated using X-ray diffraction, Raman spectroscopy, energy-dispersive X-ray spectroscopy, and scanning and transmission electron microscopy. The electrochemical properties of the samples are also examined. The optimal dry ball milling time for the uniform mixing of graphite and tin is 6 h in a graphite-30wt.%Sn sample. The electrode prepared from the composite that is dry-ball-milled for 6 h exhibits the best cycle performance (discharge capacity after 50^th cycle: 308 mAh/g and capacity retention: 46%). The discharge capacity after the 50^th cycle is approximately 112 mAh/g, higher than that when the electrode is composed of only graphite (196 mAh/g after 50^th cycle). This result indicates that it is possible to manufacture a tin/graphite composite anode material that can effectively buffer the volume change that occurs during cycling, even using a simple dry ball-milling process.

• The Korean Journal of Food & Health Convergence
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• v.5 no.3
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• pp.35-40
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• 2019

In this study, general bacterial counts and coliform counts, which are hygienic indicator microorganisms, were tested for candy, chocolate, and jelly which are easily available and enjoyed around. After dropping each sample on the desk, indoors, and outdoors, it is immediately collected, or washed and collected to confirm the myth of the 3-second rule. Immediately after removing the wrapping paper, each sample was dropped on the desk, indoors, and outdoors, and after 3 seconds from the moment of contact with the surface, and then collected in a sample bag using sterilized sanitary gloves. After the same operation, each sample was rinsed for 5 seconds using sterilized sanitary gloves and sterilized distilled water, and then collected in a sample bag. The number of bacteria detected in non-washing candies was 41 CFU/g at outdoor and the number of bacteria detected in non-washing chocolate was 76 CFU/g at outdoor. The number of bacteria detected in non-washing jellies was 79 CFU/g at outdoor. Coliform group was not detected in all samples. This showed good results at the level of m = 10,000 or less, which is an allowable value suggested in the Food Code. Also, effect of washing on contaminated food was confirmed. This result is remarkably low compared with the microorganism specimens shown in Food Code, and it is confirmed that contamination occurs but not high value. Therefore, the myth of the 3-second rule is true compared to the figures based on Food Code. However, it showed the characteristics of bacteria that could survive and cross-contaminate on dry food surfaces and emphasized the importance of hygiene through food contact to unsanitary surfaces to minimize the risk of food poisoning.

• Animal Bioscience
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• v.37 no.7
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• pp.1196-1203
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• 2024

Objective: A study was conducted to quantify the performance differences of the near-infrared spectroscopy (NIRS) calibration models developed with different degrees of hay sample preparations. Methods: A total of 227 imported alfalfa (Medicago sativa L.) and another 360 imported timothy (Phleum pratense L.) hay samples were used to develop calibration models for nutrient value parameters such as moisture, neutral detergent fiber, acid detergent fiber, crude protein, and in vitro dry matter digestibility. Spectral data of hay samples prepared by milling into 1-mm particle size or unground were separately regressed against the wet chemistry results of the abovementioned parameters. Results: The performance of the developed NIRS calibration models was evaluated based on R², standard error, and ratio percentage deviation (RPD). The models developed with ground hay were more robust and accurate than those with unground hay based on calibration model performance indexes such as R² (coefficient of determination), standard error, and RPD. Although the R² of calibration models was mainly greater than 0.90 across the feed value indexes, the R² of cross-validations was much lower. The R² of cross-validation varies depending on feed value indexes, which ranged from 0.61 to 0.81 in alfalfa, and from 0.62 to 0.95 in timothy. Estimation of feed values in imported hay can be achievable by the calibrated NIRS. However, the NIRS calibration models must be improved by including a broader range of imported hay samples in the modeling. Conclusion: Although the analysis accuracy of NIRS was substantially higher when calibration models were developed with ground samples, less sample preparation will be more advantageous for achieving rapid delivery of hay sample analysis results. Therefore, further research warrants investigating the level of sample preparations compromising analysis accuracy by NIRS.

• Journal of Conservation Science
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• v.30 no.1
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• pp.27-32
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• 2014

The sample book was printed in 1935. Since the books in the early twentieth century were printed using acidic paper, the color of the paper would change to brown over time due to iron corrosion. In addition to corroding iron cores, the acidity of the paper (pH 3.2) also made the paper brown and fragile, as was true in the case of the sample book. To clean the paper of the sample book and to make it strong, we replaced the iron core and performed wet cleaning on the paper to remove contaminants. Then we pressed the sample book dry, and subsequently linening every page with Minoshi($4g/m^2$). Generally, book conservator rebinding the book using wires or threads: however we have devised a new method to rebind the book using colored iron cores. To color the iron core brown, they were dipped in an aqueous coloring solution ($H_2O$, $C_2H_5OH$, $CuSO_4{\cdot}5H_2O$, $FeCl_3{\cdot}6H_2O$); subsequently, a 20% paraloid B-72 was applied to protect the colored iron cores from corrosion.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.6
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• pp.1010-1020
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• 1997

For this study, we did needlework of the sample considering practical aspects of production and consumption of silk, high-quality material for women's clothes, and then analyzed the state of the seam puckering after press and dry cleaning, estimated the Seam Puckering based on the mechanical properties of silk related to machine sewing, and examined the effects which Mechanical Properties have on Seam Puckering closely. Through this, we reach the following conclusion. 1. There are three types of seam puckering for each stage, which are caused bathe smoothness of the surface by press, and the difference between the shrinkage rates of fabric and sewing thread by Dry Cleaning. 2. In analyzing seam puckering classified by each step, seam puckering after sewing the fabric is related to WT negatively, while to RT and W positively. Seam puckering after sewing and pressing the fabric is related to WT, RC, MMD negatively and seam puckering after sewing, pressing anddry cleaning the fabric isrelated to WT negatively, too. 3. Concerning the mechanical properties of the sample with a little seam puckering, WT, LC, WC, RC, MMD, SMD is relatively large while RT, B, 2HB is small. 4. Judging from the result of estimating seam puckering based on mechanical properties, the estimate-formula is satisfied in this study.

• The Korean Journal of Food And Nutrition
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• v.11 no.4
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• pp.444-451
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• 1998

The changes of amine, nitrate and nitrite nitrogen in yellow corvenia were studied during its processing and storage in order to clarify the precursors of N-nitrosamine(NA) formation in the salted and dried yellow corvenia(Gulbi), prepared y using the different salting method like dry and brine salting by pure and curde salt. As a result, during the processing and storage of Gulbi, DMA and TMA contents were significantly increased in the yellow corvenia. And after 40 days storage the increase rate showed 25.7∼45.7, 3.3∼5.6 times higher than those of 0.3, 2.4mg/kg, respectively, while nitrite contents, during its processing and storage, were scarcely changed in the salted and dried yellow corvenia. During the processing and storage, of Gulbi, DMA and TMA contents were less produced in brine salted and dried yellow corvenia using crude salt than in sample prepared using were scarcely changed in the salted and dried yellow corvenia. During the processing and storage of Gulbi, DMA and TMA contents were less produced in brine salted and dried yellow corvenia using crude salt than in sample prepared using pure salt, while the former were more effective than the latter in inhibiting the production of nitrate and nitrite. Therefore, it was revealed that reduction of NA precursors such as DMA, TMA, nitrate and nitrite were more effective in preparing with the brine salting method than with the dry salting method.

• The Korean Journal of Food And Nutrition
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• v.11 no.4
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• pp.452-459
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• 1998

In 7 kinds of Gulbi purchansed from Yosu, Sunchon and Chinju, N-nitrosamine (NA) such as N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA) and N-nitrosodipropylamine(NDPA), were detected and their content was 2.8∼78.3$\mu\textrm{g}$/kg, trace and 0∼1.4$\mu\textrm{g}$/kg, respectively. This experiment was conducted to study the effect of processing conditions on NA formation in the salted and dried yellow corvenia(Guibi), prepared by using the different salting method like dry and brine salting by pure and crude salt. NDMA, NDEA and NDPA were not detected in raw sample, but NDMA content increased in yellow corvenia during its salting (27.6∼37.4$\mu\textrm{g}$/kg), and then drastically decreased in Gulbi stored for 40 days, ranging from 2.8 to 4.3$\mu\textrm{g}$/kg. Content of above NA was inhibited more effectively in the samples prepare with brine salting method than with the dry salting method during its processing and storage. Especially, NA in the sample prepared with brine salted and dried yellow corvenia using the pure salt was detected in the lower concentrations, and that of NDMA, NDEA and NDPA was 2.8∼27.6, trance and ND-2.7$\mu\textrm{g}$/kg, respectively.