• Title/Summary/Keyword: 열 실험

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Evaluation of Skin Dose and Image Quality on Cone Beam Computed Tomography (콘빔CT 촬영 시 mAs의 변화에 따른 피부선량과 영상 품질에 관한 평가)

  • Ahn, Jong-Ho;Hong, Chae-Seon;Kim, Jin-Man;Jang, Jun-Young
    • The Journal of Korean Society for Radiation Therapy
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    • v.20 no.1
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    • pp.17-23
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    • 2008
  • Purpose: Cone-beam CT using linear accelerator attached to on-board imager is a image guided therapy equipment. Because it is to check the patient's set-up error, correction, organ and target movement. but imaging dose should be cause of the secondary cancer when taking a image. The aim of this study is investigation of appropriate cone beam CT scan mode to compare and estimate the image quality and skin dose. Materials and Methods: Measurement by Thermoluminescence dosimeter (TLD-100, Harshaw) with using the Rando phantom are placed on each eight sites in seperately H&N, thoracic, abdominal section. each 4 methods of scan modes of are measured the for skin dose in three time. Subsequently, obtained average value. Following image quality QA protocol of equipment manufacturers using the catphan 504 phantom, image quality of each scan mode is compared and analyzed. Results: The results of the measured skin dose are described in here. The skin dose of Head & Neck are measured mode A: 8.96 cGy, mode B: 4.59 cGy, mode C: 3.46 cGy mode D: 1.76 cGy and thoracic mode A: 9.42 cGy, mode B: 4.58 cGy, mode C: 3.65 cGy, mode D: 1.85 cGy, and abdominal mode A: 9.97 cGy, mode B: 5.12 cGy, mode C: 4.03 cGy, mode D: 2.21 cGy. Approximately, dose of mode B are reduced 50%, mode C are reduced 60%, mode D are reduced 80% a point of reference dose of mode A. the results of analyzed HU reproducibility, low contrast resolution, spatial resolution (high contrast resolution), HU uniformity in evaluation item of image quality are within the tolerance value by recommended equipment manufacturer in all scan mode. Conclusion: Maintaining the image quality as well as reducing the image dose are very important in cone beam CT. In the result of this study, we are considered when to take mode A when interested in soft tissue. And we are considered to take mode D when interested in bone scan and we are considered to take mode B, C when standard scan. Increasing secondary cancer risk due to cone beam CT scan should be reduced by low mAs technique.

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Antibacterial Activity of Sodium Phytate Against Salmonella typhimurium in Meats (식육에서 피틴산염의 Salmonella typhimurium균에 대한 항균효과)

  • Baek, Dong-Jin;Hue, Jin-Joo;Lee, Yea-Eun;Lee, Ki-Nam;Nam, Sang-Yoon;Yun, Young-Won;Jeong, Jae-Hwang;Lee, Sang-Hwa;Lee, Beom-Jun
    • Journal of Food Hygiene and Safety
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    • v.22 no.4
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    • pp.382-387
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    • 2007
  • The approval of use of certain food-grade phosphates as food additives in a wide variety of meat products greatly stimulated research on the applications of phosphates in foods. Phytic acid is a natural plant inositol hexaphosphate constituting 1-5% of most cereals, nuts, legumes, oil seeds, pollen, and spores. In this study, we investigated antibacterial activity of sodium phytate (SPT) against Salmonella typhimurium in tryptic soy broth with different pHs and in chicken, pork and beef. In tryptic soy broth, SPT at the concentrations of 0.1, 0.5, and 1.0% effectively inhibited the growth of Salmonella typhymurium in a concentration-dependent manner. At pH 5.5-7.0 similar to meat pHs, 1% SPT almost completely inhibited the bacterial growth. The inhibitory effect of SPT was stronger at pH 7.0 than pH 5.5. In chicken, pork, and beef, SPT at the concentrations of 0.1, 0.5, and 1% significantly inhibited the growth of Salmonella typhimurium in a dose-dependant manner (p<0.01). The addition of 1% SPT in the meats significantly increased the meat pHs. These results indicate that SPT is very effective for inhibition of bacterial growth as a muscle food additive for increasing food safety and functions.

Evaluation of Selective Media for Isolation of Staphylococcus aureus from Agricultural Products (농산물 중 Staphylococcus aureus의 분리를 위한 선택배지 평가)

  • Kim, Se-Ri;Lee, Seo-Hyun;Seo, Min-Kyoung;Kim, Won-Il;Park, Kyeong-Hun;Yun, Hye-Jeong;Yoon, Yo-Han;Yoo, Soon-Young;Ryu, Kyoung-Yul;Yun, Jong-Chul;Kim, Byung-Seok
    • Journal of Food Hygiene and Safety
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    • v.27 no.2
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    • pp.169-175
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    • 2012
  • Five kinds of selective media, such as mannitol salt agar (MSA), Baird-Parker agar (BPA), Baird-Parker supplemented with rabbit plasma fibrinogen (BPA+RPF), CHROMagar Staphylococcus aureus (CSA), and Petrifilm Staph Express count system (Petrifilm), were compared to recommend the optimum selective media for isolation of Staphylococcus aureus from agricultural products. Seventy four target and non target bacteria were inoculated on five selective media to analyze sensitivity and specificity. In the recovery test of injured S. aureus cells, S. aureus was exposed to acid (1% lactic acid for 10 min), heat ($60^{\circ}C$ for 90s), and cold ($-20^{\circ}C$ for 1h) conditions. And artificially contaminated agricultural products (iceberg lettuce, green pepper, and cherry tomato) was enumerated on five selective media. The sensitivity of BPA+RPF, CSA, Petrifilm, MSA, and BPA were 100%, 100%, 100%, 90.5%, 90.5%, respectively. In addition, the specificity of BPA+RPF, CSA, MSA, BPA and Petrifilm were 100%, 100%, 84.6%, 75.0%, 67.3%, respectively. However, no difference among five selective media was observed in recovery on injured S. aureus cell and enumeration from agricultural products. This results suggest that BPA+RPF and CSA are the optimum media for detection of S. aureus from agricultural products.

Comparison on the Dosimetry of TLD and PLD by Dose Area Product (DAP(Dose Area Product)를 이용한 TLD와 PLD의 선량 측정 비교)

  • Choi, Jae-Ho;Kang, Gu-Jun;Chang, Seo-Goo
    • The Journal of the Korea Contents Association
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    • v.12 no.3
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    • pp.244-250
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    • 2012
  • The results of analyzing the difference between performances of individual dosimeters on this research subjecting the PLD and TLD, which are the official personal dosimeters, through dosimetry are as follows. After scanning the integral dose using an automatic scanner, the values of two devices that went through dose adjustment process had a statistical difference in TLD and PLD measurements under each filming conditions which were 70kVp, 200mA, 0.012sec and 42kVp, 100mA, and 0.012sec (p<0.001 and p<0.001 respectively). As for the difference of measurement value between DAP and the two particles under 70kVp, 200mA, 0.012sec filming condition, TLD had a value lower than DAP average value by $44.2mGy{\cdot}cm^2$ and PLD had a value of $246.8mGy{\cdot}cm^2$ which was lower than DAP average value by $15.5mGy{\cdot}cm^2$, while under 42kVp, 100mA, 0.012sec filming condition, TLD had a value lower than DAP average value by $17.9mGy{\cdot}cm^2$ and PLD had a value of $82.6mGy{\cdot}cm^2$ which was lower than DAP average value by 7.6$mGy{\cdot}cm^2$. Also, compared to PLD, each of 10 devices measured dose value in TLD had a larger deviation between the particles, and for a reproducibility test which repeatedly measured one particle, PLD had ${\pm}1%$ which was lower than TLD's ${\pm}2%$. As such, PLD had a superior performance result in dose measurement capacities aspect compared to TLD, and therefore we could verify that PLD is more appropriate and advantageous in managing radiation-related task performing worker's personal radiation exposure management in the diagnostic radiation field.

Effects of Passtein® Supplements on Protein Degradability, Ruminal Fermentation and Nutrient Digestibility (패스틴®첨가가 단백질 분해율과 반추위 발효 및 영양소 소화율에 미치는 영향)

  • Choi, Y.J.;Choi, N.J.;Park, S.H.;Song, J.Y.;Um, J.S.;Ko, J.Y.;Ha, J.K.
    • Journal of Animal Science and Technology
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    • v.44 no.5
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    • pp.549-560
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    • 2002
  • This study, including two in vitro experiments and an in vivo experiment were conducted to evaluate effects of Passtein$^{(R)}$ on crude protein degradability, ruminal fermentation characteristics and nutrient digestibility. In in vitro experiment protein degradability was examined using borate-phosphate buffer and neutral detergent, and using protease from Stroptomyces griseus at 39$^{\circ}C$ for 0, 2, 4, 8, 12, and 48 h. In addition, an in vivo experiment was conducted in a switch back design and ruminal fermentation and nutrient digestibility were determined. Four ruminal-fistulated Holstein cows weighing 300kg in mean body weight randomly allotted to 2 treatments (control and Passtein$^{(R)}$ supplementation). Although there was no significant difference on protein fraction between treatments, it appears that Passtein$^{(R)}$ supplementation decreased buffer soluble protein fraction compared to control. Protein degradability was not affected by Passtein$^{(R)}$ from 0 h to 4 h, but decreased at 12 h and 48 h compared to control. Degradation of immediately degradable fraction was higher in Passtein$^{(R)}$ treatment, but degradation of fermentable fraction was lower in Passtein$^{(R)}$ treatment compared to control. The pH and $NH_3$-N concentration tended to increase in Passtein$^{(R)}$ treatment, but VFA production, microbial counts and enzyme activity tended to decrease in Passtein$^{(R)}$ treatment compared to control. In addition, nutrient digestibility in the total tract tended to increase in Passtein$^{(R)}$ treatment compared to control.

A Study on Trust and Commitment between Buyer and Supplier of Industrial Parts, and Their Usage of Information Technology (산업재 부품 구매자와 공급자의 신뢰와 몰입, 그리고 정보기술의 이용에 관한 연구)

  • Kim, Jong-Hun;Yun, Hui-Taek
    • Proceedings of the Korean DIstribution Association Conference
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    • 2006.08a
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    • pp.47-68
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    • 2006
  • This study aims to determine the association structure of the behavioral relationship variables, such as trust, commitment, cooperation, communication and coercive power, in the relationship between the buyers and suppliers of industrial parts. It also investigates the impact of the use of IT technologies on the relationships quality. Data was collected from 216 part suppliers of machinery, electronics and automobiles located in Incheon. Data supported all of the proposed hypotheses. First, it was confirmed that parts suppliers' trust in buyers leads to the commitment into relationships with buyers. Second, cooperation and communication showed a positive influence on parts suppliers' trust in buyers, and coercive power gave a negative influence on trust. Third, the use of IT technologies like Internet and E-Mail between parts suppliers and buyers was verified to have generally a positive influence on the quality of relationships. At the same time, cooperation and communication were confirmed to have a positive influence on each other, and cooperation and coercive power as well as communication and coercive power were confirmed to have negative influence on each other. This study is a pioneering attempt to examine the relationships between suppliers and buyers of industrial parts, and the influence IT technologies on the relationship quality. Also, the findings will be practically much helpful to find how to reinforce the relationships between parts suppliers and buyers.

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Studies on the Packaging and Preservation of Kimchi (우리나라 김치의 포장과 저장방법에 관한 연구)

  • Lee, Yang-Hee;Yang, Ick-Whan
    • Applied Biological Chemistry
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    • v.13 no.3
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    • pp.207-218
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    • 1970
  • Studies were carried out to develope the most economical and practical methods of packaging and preservation of kimchi, so commercialization of kimchi manufacture could proceed rapidly. The results obtained may be summarized as following. (1) It is generally established that the acceptable range of lactic acid content of kimchi is between 0.4% and 0.75%. Based on sensory evaluation, kimchi having lactic acid content below 0.4% and above 0.75% was not edible, and the time of optimum taste corresponded to the vicinity of 0.5% of lactic acid content. For the refrigeration storage with or without preservatives, the packaging kimchi in plastic film must be done at the lactic acid content of 0.45%, for lactic acid fermentation will continue slowly after the packaging. However, for the heat sterilized kimchi the packaging should be done at the 0.5% of lactic acid content for the best because lactic acid fermentation is completely stopped after the packaging. (2) Polyethylene, polypropylene, and polycello were chosen as suitable packaging materials. Polyethylene is cheapest among them but kimchi packaged in this film was damaged frequently in handling process and gave off kimchi flavor. On the other hand polypropylene also gave off kimchi flavor, but its higher mechanical strength gave better protection to kimchi and it had superior display effect due to the transparancy. Therefore polypropylene made much better packaging material. Polycello proved to be the best packaging material from the standpoint of physical characteristics but its price is higher than that of other plastic films. To be effective, the thickness of plastic films for packaging kimchi must exceed 0.08mm. (3) Keeping property of kimchi appeared to be excellent by means of freezing. However, by the time the frozen kimchi was thawed out at room temperature, moisture loss due to drip was extensive, rendering the kimchi too stringy. (4) Preservation of kimchi at refrigerated temperatures proved to be the best method and under the refrigerated condition the kimchi remained fresh as long as 3 months. The best results were obtained when kimchi was held at $0^{\circ}C$. (5) In general, preservatives alone were not too elective in preserving kimchi. Among them potassium sorbate appeared to be most effective with the four fold extension of self-life at $20^{\circ}C$ and two fold extension at $30^{\circ}C$. (6) In heat sterilization the thickness of packaged kimchi product had a geat effect upon the rate of heat penetration. When the thickness ranged from 1.5 to 1.8cm, the kimchi in such package could be sterilized at $65^{\circ}C$ for 20 minutes. Kimchi so heat treated could be kept at room temperature as long as one month without apparent changes in quality. (7) Among combination methods, preservation at refrigerated and heat sterilization could be favorably combined. When kimchi was stored at $4^{\circ}C$ after being sterilized at $65^{\circ}C$ for 20 minutes, it was possible to preserve the kimchi for more than 4 months.

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Antioxidant and Sensory Properties of Hot Water Extract of Liriope Tubers treated at Various Preprocess (전처리방법에 따른 맥문동 열수 추출물의 항산화성과 관능 특성)

  • Yang, Mi-Ok
    • Journal of the East Asian Society of Dietary Life
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    • v.23 no.5
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    • pp.645-653
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    • 2013
  • The results of examining total soluble solid, reducing sugar, antioxidant and sensory properties regarding LTD (Liriope Tuber Dried), LTSD (Liriope Tuber Steamed and Dried), LTASD (Liriope Tuber Alcohol-Steamed and Dried), LTDR (LTD Roasted), LTSDR (LTSD Roasted) and LTASDR (LTASD Roasted) are as follows : Total soluble solid content of the roasted samples (LTDR, LTSDR and LTASDR) was more than those of all dried samples (LTD, LTSD and LTASD). According to roasting conditions, total sugar and reducing sugar are significantly greater than the raw and dried sample (LTD) in all heat-treated samples. The browning index was significantly higher in all roasted samples. In particular, LTASDR had a high browning index. Further, the antioxidative activity of the roasted LT samples were higher than that of all dried LT samples. In particular, the LTASDR sample showed significantly high figures in DPPH scavenging activity, ABTS scavenging activity, Nitrite scavenging activity and xanthine oxidase inhibitory activity. Sensory properties showed an increased acceptance in all evaluation items among roasted samples. In this study, hot water extracts of steamed or alcohol-steamed roasted LT samples had a higher antioxidative effect than that of LTD or LTDR and attained positive results by getting high scores in the overall sensory evaluation. Therefore, when using Liriope tuber in making beverages or herbal recipes, it is appropriate to dry and roast before steaming or spreading with alcohol when treating LT.

Assessment of Physiological Activity of Entomopathogenic Fungi with Insecticidal Activity Against Locusts (풀무치에 대하여 살충활성을 보유한 곤충병원성 진균의 생리활성 평가)

  • Lee, Mi Rong;Kim, Jong Cheol;Lee, Se Jin;Kim, Sihyeon;Lee, Seok Ju;Park, So Eun;Lee, Wang Hyu;Kim, Jae Su
    • Korean journal of applied entomology
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    • v.56 no.3
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    • pp.301-308
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    • 2017
  • Locusts, Locusta migratoria (Orthoptera: Acrididae) are periodical unpredictable agricultural pests worldwide and cause serious damage to crop production; however, little consideration has been given to the management of this pest. Herein, we constructed a locust-pathogenic fungal library and confirmed that some fungi could be used as resources for locust management. First, the entomopathogenic fungi were collected from sampled soils using a Tenebrio molitor-based baiting system. For the locust assay, a locust colony was obtained from the National Institute of Agricultural Science and Technology. A total of 34 entomopathogenic fungal granules, which were produced by solid cultures, were placed in the plastic insect-rearing boxes (2 g/box) and nymphs of locust were contained in the box. In 3-7 days, mycosis was observed on the membranous cuticles of the head, abdomen, and legs of locusts. In particular, Metarhizium anisopliae, M. lepidiotae, and Clonostachys rogersoniana exhibited high virulence against the locust. Given that the 34 isolates could be used in field applications, their conidial production and stability (thermotolerance) were further characterized. In the thermotolerance assay, Paecilomyces and Purpureocillium isolates had higher thermotolerance than the other isolates. Most of the fungal isolates produced ca. >$1{\times}10^8conidia/g$ on millet grain medium. In a greenhouse trial, the granular application of M. anisopliae isolate on the soil surface resulted in 85.7% control efficacy. This work suggests that entomopathogenic fungi in a granular form can be effectively used to control the migratory locust.

Synthesis and Characterization of Magnetic Core-shell ZnFe2O4@ZnO@SiO2 Nanoparticles (Magnetic Core-shell ZnFe2O4@ZnO@SiO2 Nanoparticle의 합성과 성질에 관한 연구)

  • Yoo, Jeong-Yeol;Lee, Young-Ki;Kim, Jong-Gyu
    • Journal of the Korean Chemical Society
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    • v.59 no.5
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    • pp.397-406
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    • 2015
  • ZnO, II-VI group inorganic compound semi-conductor, has been receiving much attention due to its wide applications in various fields. Since the ZnO has 3.37 eV of a wide band gap and 60 meV of big excitation binding energy, it is well-known material for various uses such the optical property, a semi-conductor, magnetism, antibiosis, photocatalyst, etc. When applied in the field of photocatalyst, many research studies have been actively conducted regarding magnetic materials and the core-shell structure to take on the need of recycling used materials. In this paper, magnetic core-shell ZnFe2O4@SiO2 nanoparticles (NPs) have been successfully synthesized through three steps. In order to analyze the structural characteristics of the synthesized substances, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR) were used. The spinel structure of ZnFe2O4 and the wurtzite structure of ZnO were confirmed by XRD, and ZnO production rate was confirmed through the analysis of different concentrations of the precursors. The surface change of the synthesized materials was confirmed by SEM. The formation of SiO2 layer and the synthesis of ZnFe2O4@ZnO@SiO2 NPs were finally verified through the bond of Fe-O, Zn-O and Si-O-Si by FT-IR. The magnetic property of the synthesized materials was analyzed through the vibrating sample magnetometer (VSM). The increase and decrease in the magnetism were respectively confirmed by the results of the formed ZnO and SiO2 layer. The photocatalysis effect of the synthesized ZnFe2O4 @ZnO@SiO2 NPs was experimented in a black box (dark room) using methylene blue (MB) under UV irradiation.