• Title/Summary/Keyword: resistance change

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A Study on Thermal Characteristics of Carbon-Organic Surface Heating Element with Electrodeless Lamp of a Freezer (냉동고 무전극램프 적용 탄소-유기소재 면상발열체의 열 특성에 관한 연구)

  • Lee, Min-Sang;Back, Seong-Hun;Kang, Sung-Soo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.1
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    • pp.1-10
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    • 2020
  • This study deals with the fabrication and thermal characterization of planar heating elements attached to the backside of the reflector used in the electrodeless lamp of a freezer. We tried to solve the problem of the local heat generation of the linear heating element that occurs about 50℃. The homogeneous dispersion and manufacturing excellence of the planar heating element produced were confirmed through SEM and EDS. In addition, the test specimens was prepared according to the change in the ratio of carbon fiber to the basis weight of the planar heating element, and a sample having a basis weight of 50g/㎡ having a content ratio of carbon fiber of 70% was selected. That sample showed low surface resistance of 4.3Ω/sq and high temperature of about 81℃ at 6V. Durability was confirmed by performing repeated bending evaluation of 3000 cycles for the sample. Large area test specimens were prepared to be applied to the actual reflector, insulated by EVA film and analyzed for their thermal characteristics. From 13V application, the temperature of the linear heating element was higher than 50℃ and the average temperature of 68℃ was maximum at 18V.

Influences of Squid Ink Added to Low-Salted Squid Jeot-gal on Its Proteolytic Characteristics (오징어 먹즙 첨가가 저 식염 오징어 젓갈의 단백질분해 특성에 미치는 영향)

  • Oh, Sung-Cheon
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.2
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    • pp.348-355
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    • 2013
  • Squid ink was added to the salt fermented squid by 2% or 4% of concentration and ripened at $10^{\circ}C$ for 8 weeks and at $20^{\circ}C$ for 32days. The effects of the squid ink on the amino nitrogen and muscle protein of salt fermented squid were investigated. The results are as follows; As the salt concentration was decreased and the fermentation temperature raised, amino nitrogen in the salt fermented squid without addition of the squid ink was significantly increased to the latter stage of the ripening and hence fermentations were enhanced. From the change of the protein in the squid muscle in the experiments, dissolution of the myosin heavy chain took place conspicuously in the early stage of the ripening while actin was rarely changed which resulted in the strong resistance to protease. The amino nitrogen content in the salt fermented squid addition of the squid ink has increased to the latter part of the ripening but the range was smaller than no treatment groups. The protein in squid muscle, especially the myosin heavy chain was remarkably dissolved in the middle of the ripening whereas the squid ink added groups of high salt concentration and low temperature showed the tendency of slow proteolysis.

Synergistic Effect of Citric Acid and Pediocin K1, a Bacteriocin Produced by Pediococcus sp. K1, on Inhibition of Listeria monocytogenes

  • KIM, SOO YEON;YOUNG MIN LEE;SUN YOUNG LEE;YEON SOOK LEE;JEONG HWAN KIM;CHEOL AHN;BYUNG CHEOL KANG;GEUN-EOG JI
    • Journal of Microbiology and Biotechnology
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    • v.11 no.5
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    • pp.831-837
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    • 2001
  • Pediocin K1, a bacteriocin produced by Pediococcus sp. K1 isolated from Korean traditional fermented flatfish, inhibited certain strains of Lactobacillus, Streptococcus, and Listeria monocytogenes. Pediocin K1 was found to be stable at $90^{\circ}C$ for 30 min. Among the organisms tested, Listeria monocytogenes was the most sensitive to pediocin K1 and was completely killed when the initial inoculum size of L.monocytogenes cells was equal to or less than $10^3 CFU/ml$. The degree of inibition of Listeria monocytogenes by pediocin K1 increased 10-fold on the addition of citric acid ($0.2\%$) to the medium, thereby showing the synergistic effect of citric acid. Listeria monocytogenes cells resistant to pediocin K1 appeared at a frequency of about $10^-4$/cells. Once developed after exposure to pediocin K1, the resistant phenotype still persisted in the absence of pediocin K1 in successive cultures. This infers that resistance may be attributable to genetic change(s) in the resistant cells.

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Genotype by Dietary Lysine Interaction for Growth and Response to Sheep Red Blood Cells and Escherichia coli Inoculation in Commercial Broiler Chicks

  • Praharaj, N.K.;Reddy, M.R.;Panda, A.K.;Rama Rao, S.V.;Sharma, R.P.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.8
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    • pp.1170-1177
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    • 2002
  • An experiment was conducted to assess the interaction between genotypes and dietary lysine content in commercial broiler chicks by measuring growth, and response to sheep red blood cells (SRBC) and Escherichia coli (E.coli) inoculation. Female chicks from four genotypes (A=Anak 2000; B=Hubbard; C=Cobb and D=Synthetic broiler) were fed four levels of lysine in diet from d old till the end of experiment. The lysine content of the diet was 9.61, 10.51, 11.41 and 12.31 g/kg. Body weights at 0, 14, 28 and 42 d of age and pen-wise feed intake till 14, 28 and 42 d of age were recorded. Production of antibody against SRBC and resistance to E.coli were measured at 5 d of post inoculation (PI) at 43 d of age. Also, response to phytohemaglutinin-P (PHA-P) was measured at 12 and 24 h of PI at 48 d of age. Genotype by dietary lysine interaction was significant for body weights at 14 and 28 d of age, but not at 42 d of age. Genotype by dietary lysine interaction was not significant for feed efficiency, for antibody titers against SRBC, and for air sac lesion score, relative bodyweight change, and relative weights of bursa and spleen in response to E.coli inoculation. However, a significant interaction was observed between the levels of lysine and dosage of SRBC for antibody titers. There was significant genotype by dietary lysine interaction for cutaneous basophilic hypersensitivity (CBH) response to PHA-P at 12 and 24 h of PI. It may be concluded that to obtain optimum body weight and immunity in commercial broilers the dietary lysine requirement may be recommended specific to the genotype.

Current status and prospects for in-feed antibiotics in the different stages of pork production - A review

  • Li, Junyou
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.12
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    • pp.1667-1673
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    • 2017
  • Antibiotics have long been of great benefit for people, both in the medical treatment of human disease and in animal food where they improve the growth performance and feed utilization during animal production. Antibiotics as in-feed supplements affect all stages of pork production, including the gestation, nursing, growing, and finishing stages, although the effects show stage-dependent differences. However, the use of antibiotics in animal feed has become a worldwide concern. This review describes why sub-therapeutic levels of antibiotic additives in animal feed have become an integral part of animal feeding programs for more than 70 years, particularly in pork production. It also discusses the threat of the long-term use of sub-therapeutic levels of antibiotics in pork production. In recent years, the effectiveness of in-feed antibiotics has tended to decrease. This review analyzes this change from various perspectives. First, the equipment used at pig farms has improved dramatically and is more sanitary. Worldwide, more pig farms use pig farrowing crates, gestation crates, piglet nursery crates, flooring devices, piggery ventilation and cooler systems, automatic pig feeders, piggery heating equipment, and artificial insemination systems. In addition, scientists have replaced the use of antibiotics with organic acids, fermented mash, probiotics, prebiotics, minerals, oligosaccharides, enzymes, herbs/flavors, and protein/amino acids, and have improved management and husbandry techniques. In addition, animal welfare legislation has been aimed at improving the quality of the floors and living space, ensuring that animals have permanent access to fresh water, and setting a minimum weaning age. Finally, the prospects and the possibility of replacing antibiotics in pork production are described, in line with recent research results.

Retrospective study of changes in pharyngeal airway space and position of hyoid bone after mandibular setback surgery by cephalometric analysis

  • Cho, Hyun-Woo;Kim, Il-Kyu;Cho, Hyun-Young;Seo, Ji-Hoon;Lee, Dong-Hwan;Park, Seung-Hoon
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.37
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    • pp.38.1-38.6
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    • 2015
  • Background: The posterior movement of mandible was known as the main cause of the changes in the pharyngeal airway space (PAS) and the postoperative obstructive sleep apnea (OSA). The purpose of this study was to know the changes of PAS and position of hyoid bone. Methods: Lateral cephalographies of 13 patients who had undergone sagittal split ramus osteotomy (SSRO) setback surgery were taken preoperatively (T1), postoperatively within 2 months (T2), and follow-up after 6 months or more (T3). On the basis of F-H plane, diameters of nasopharynx, oropharynx, and hypopharynx were measured. The movements of the soft palate, tongue, and hyoid bone were also measured. Results: The amount of mandible setback was $7.5{\pm}3.8mm$. In the measurements of PAS, there was a statistically significant decrease of $2.8{\pm}2.5mm$ in nasopharynx (P < 0.01), and $1.7{\pm}2.4mm$ in oropharynx (P < 0.01) were observed after surgery. The hypopharynx decreased $1.0{\pm}2.1mm$ after surgery and continuously decreased $1.0{\pm}2.8mm$ at follow-up. The changes in hyoid bone position showed the posterior movement only after surgery and posteroinferior movement at follow-up. Conclusions: The PAS such as nasopharynx, oropharynx, and hypopharynx showed relatively high correlation with the amount of mandibular setback. The change of resistance in upper airway may be important for the prevention of OSA after mandibular setback surgery.

Elevation of heart-femoral pulse wave velocity by short-term low sodium diet followed by high sodium diet in hypertensive patients with sodium sensitivity

  • Rhee, Moo-Yong;Kim, Ji-Hyun;Na, Sang-Hoon;Chung, Jin-Wook;Bae, Jun-Ho;Nah, Deuk-Young;Gu, Namyi;Kim, Hae-Young
    • Nutrition Research and Practice
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    • v.10 no.3
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    • pp.288-293
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    • 2016
  • BACKGROUND/OBJECTIVES: We compared changes in heart-femoral pulse wave velocity (hfPWV) in response to low sodium and high sodium diet between individuals with sodium sensitivity (SS) and resistance (SR) to evaluate the influence of sodium intake on arterial stiffness. SUBJECTS/METHODS: Thirty-one hypertensive and 70 normotensive individuals were given 7 days of low sodium dietary approach to stop hypertension (DASH) diet (LSD, 100 mmol NaCl/day) followed by 7 days of high sodium DASH diet (HSD, 300 mmol NaCl/day) during 2 weeks of hospitalization. The hfPWV was measured and compared after the LSD and HSD. RESULTS: The hfPWV was significantly elevated from LSD to HSD in individuals with SS (P = 0.001) independently of changes in mean arterial pressure (P = 0.037). Conversely, there was no significant elevation of hfPWV from LSD to HSD in individuals with SR. The percent change in hfPWV from the LSD to the HSD in individuals with SS was higher than that in individuals with SR. Subgroup analysis revealed that individuals with both SS and hypertension showed significant elevation of hfPWV from LSD to HSD upon adjusted analysis using changes of the means arterial pressure (P = 0.040). However, there was no significant elevation of hfPWV in individuals with SS and normotension. CONCLUSION: High sodium intake elevated hfPWV in hypertensive individuals with SS, suggesting that high sodium intake increases aortic stiffness, and may contribute to enhanced cardiovascular risk in hypertensive individuals with SS.

Effects of vitamin D supplementation on metabolic indices and hs-CRP levels in gestational diabetes mellitus patients: a randomized, double-blinded, placebo-controlled clinical trial

  • Yazdchi, Roya;Gargari, Bahram Pourghassem;Asghari-Jafarabadi, Mohammad;Sahhaf, Farnaz
    • Nutrition Research and Practice
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    • v.10 no.3
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    • pp.328-335
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    • 2016
  • BACKGROUND/OBJECTIVES: Vitamin D plays an important role in the etiology of gestational diabetes mellitus (GDM). This study evaluated the effect of vitamin D supplementation on metabolic indices and hs-C-reactive protein (CRP) levels in GDM patients. SUBJECTS/METHODS: The study was a randomized, placebo-controlled, double-blinded clinical trial. Seventy-six pregnant women with GDM and gestational age between 24-28 weeks were assigned to receive four oral treatments consisting of 50,000 IU of vitamin $D_3$ (n = 38) or placebo (n = 38) once every 2 weeks for 2 months. Fasting blood glucose (FG), insulin, HbA1c, 25-hydroxyvitamin D, lipid profile, hs-CRP, and homeostasis model assessment-insulin resistance (HOMA-IR) were measured before and after treatment. Independent and paired t-tests were used to determine intra- and intergroup differences, respectively. ANCOVA was used to assess the effects of vitamin D supplementation on biochemical parameters. RESULTS: Compared with the placebo group, in the vitamin D group, the serum level of 25-hydroxyvitamin D increased (19.15 vs. -0.40 ng/ml; P < 0.01) and that of FG (-4.72 vs. 5.27 mg/dl; P = 0.01) as well as HbA1c (-0.18% vs. 0.17%; P = 0.02) decreased. Improvements in the lipid profiles were observed in the vitamin D group, but without statistical significance. Significant increases in concentrations of hs-CRP, FG, HbA1c, total cholesterol, and LDL cholesterol were observed in the placebo group. No significant change in fasting insulin and HOMA-IR was observed in either group. CONCLUSIONS: In GDM patients, vitamin D supplementation improved FG and HbA1c but had no significant effects on lipid profile or hs-CRP.

Analysis on the Cultural Phenomena related to the Depiction of Women's Costume in Korean Modern Novels (한국근대소설의 여성복식에 나타난 문화현상 분석)

  • Jeon, Hyun-Sil;Hong, Na-Young
    • Journal of the Korean Society of Costume
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    • v.61 no.6
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    • pp.38-59
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    • 2011
  • This study is based on the periodical discourse of women and their costumes, described in modern novels that were published from late 1890s to the 1930s. New cultural phenomena emerged among Korean women in the period of modernization. In particular, rapid increase of jobs for women and preference for western female body shape are very noticeable phenomena that can be observed in novels of the 1930s. In addition, the symbolic meanings of female costumes are variously described in modern novels according to the periodical and spatial environment and jobs for women. The symbolic meanings are organized as 'Trophysm, Expression of sexuality, Liberation from male-dominated society, Symbolic difference between rural and urban areas, Vanity, Decadence, Mechanism tending to hide and Change of values'. And women's costumes kept changing in the boundary of 'Confliction, Coexistence and Harmonization' of traditional and western costumes. 'Confliction' phenomenon got emerged in novels published between 1900 and 1910. The resistance on traditional costumes that restricted woman's life got spread. But western female costumes as a symbol of new culture could not be generalized but accepted as high fashion. 'Coexistence' phenomenon was appeared in novels of the 1920s. At that time, the modernization for traditional costumes by female students was emerged along with trendy fashion. Also, the frequency of using western fashion items was increased in the Korean society. Therefore, it shows that western costumes in the Korean society became popularized in the coexistence with traditional costumes. 'Harmonization' phenomenon was emerged in novels of the 1930s. In the novels, the emergence of western female costumes, personal preference items, and westernized hair style implies that western costumes were absorbed into the Korean society that had kept traditional costumes.

Novel Enhanced Flexibility of ZnO Nanowires Based Nanogenerators Using Transparent Flexible Top Electrode

  • Gang, Mul-Gyeol;Ha, In-Ho;Kim, Seong-Hyeon;Jo, Jin-U;Ju, Byeong-Gwon;Lee, Cheol-Seung
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.490.1-490.1
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    • 2014
  • The ZnO nanowire (NW)-based nanogenerators (NGs) can have rectifying current and potential generated by the coupled piezoelectric and semiconducting properties of ZnO by variety of external stimulation such as pushing, bending and stretching. So, ZnO NGs needed to enhance durability for stable properties of NGs. The durability of the metal electrodes used in the typical ZnO nanogenerators(NGs) is unstable for both electrical and mechanical stability. Indium tin oxide (ITO) is used as transparent flexible electrode but because of high cost and limited supply of indium, the fragility and lack of flexibility of ITO layers, alternatives are being sought. It is expected that carbon nanotube and Ag nanowire conductive coatings could be a prospective replacement. In this work, we demonstrated transparent flexible ZnO NGs by using CNT/Ag nanowire hybrid electrode, in which electrical and mechanical stability of top electrode has been improved. We grew vertical type ZnO NW by hydrothermal method and ZnO NW was coated with hybrid silicone coating solution as capping layer to enhance adhesion and durability of ZNW. We coated the CNT/Ag nanowire hybrid electrode by using bar coating system on a capping layer. Power generation of the ZnO NG is measured by using a picoammeter, a oscilloscope and confirmed surface condition with FE-SEM. As a results, the NGs using the CNT/Ag NW hybrid electrode show 75% transparency at wavelength 550 nm and small change of the resistance of the electrode after bending test. It will be discussed the effect of the improved flexibility of top electrode on power generation enhancement of ZnO NGs.

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