• 제목/요약/키워드: dry heat treatment

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A Study on Nitridation and Oxidation Reaction of Titanium Powder (금속티타늄분말의 질화반응과 산화반응에 관한 연구)

  • Lee, Young-Ki;Sohn, Yong-Un;Cho, Young-Soo;Kim, Yong Seog;Kim, Suk-Yoon
    • Journal of the Korean Society for Heat Treatment
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    • v.8 no.2
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    • pp.137-148
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    • 1995
  • The nitridation kinetics of titanium powder were studied by isothermal and non-isothermal (dynamic) methods in high purity nitrogen under I atm pressure. For the comparison with nitridation, the oxidation kinetics of titanium powder were also studied in dry oxygen at I atm pressure. An automatic recording electrobalance was used to measure the weight gain as a function of time and temperature. For the reaction with nitrogen, the nitride was formed at over $700^{\circ}C$. The reaction with nitrogen followed the parabolic rate law, and the activation energy was calculated to be 31 kcal/mol in the isothermal method (above $900^{\circ}C$). The non-stoichiometric TiNx has been synthesized by the nitridation at a proper temperature and time, followed by the homogenizing treatment above $1100^{\circ}C$. In comparison with the stoichiometric $TiN_{1.0}$ and the non-stoichiometric TiNx ($TiN_{0.5}$ and $TiN_{0.65}$), the hot oxidation characteristics of the former is superior to that of the latter. However, both non-stoichiometric nitrides make little difference in the hot oxidation characteristics.

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Inhibitory Effect of Dry-Heat Treatment and Chemical Sanitizers against Foodborne Pathogens Contaminated on the Surfaces of Materials (재질 표면에 오염된 여러 병원성 세균에 대한 건열살균 및 살균소독제의 저해효과)

  • Bae, Young-Min;Heu, Sun-Gi;Lee, Sun-Young
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.9
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    • pp.1265-1270
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    • 2009
  • Pathogens contaminated on the surface of utensils could contribute to the occurrence of outbreaks due to cross-contamination to foods during the food preparation process. Therefore, the efficacy of chemical sanitizers (chlorine-based and alcohol-based commercial sanitizers) and dry-heat ($71^{\circ}C$) on inhibiting biofilms of five foodborne pathogens (Escherichia coli O157:H7, Salmonella Typhimurium, Pseudomonas aeruginosa, Listeria monocytogenes, and Staphylococcus aureus) on the surface of stainless steel and polypropylene were investigated in this study. Initial populations of pathogens were 8.8$\sim$9.3 and 9.4$\sim$10.3 log CFU/coupon on the surface of stainless steel and polypropylene coupon, respectively, and these populations were not significantly reduced when they were treated with water for 5 min at room temperature. Treatments with chlorine sanitizer and dry-heat were not effective on inactivating pathogens on the surfaces of stainless steel and polypropylene. In contrast, treatments with alcohol sanitizer were very effective on inactivating pathogens on the surfaced of stainless steel and polypropylene. Reduction levels ranged from 3.4 to 6.4 log and from 5.5 to 7.4 log CFU/coupon in stainless steel and plastic coupons, respectively. From these results, alcohol-based sanitizer could be used as a potential way for controlling microbial contamination on the surface of utensils, cooking equipment, and other related environments.

A Study on the Syndrome of Soseunggitang(小承氣湯證) in Sanghanlon(傷寒論) (『상한론(傷寒論)』 소승기탕증(小承氣湯證)에 대한 연구(硏究))

  • Bang, Jung-Kyun
    • Journal of Korean Medical classics
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    • v.27 no.1
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    • pp.57-65
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    • 2014
  • Objective : The syndrome of daeseunggitang(大承氣湯證) and the syndrome of soseunggitang(小承氣湯證) are different from pathogenesis of the dry stool(燥屎). Due to the lack of body fluid the syndrome of soseunggitang(小承氣湯證)'s dry stool occurs. However, Soseunggitang(小承氣湯) does not have the appropriate remedy. So I will propose a suitable remedy and I suggest it will be available for disease. Method : Study on the syndrome of soseunggitang in Sanghanlon(傷寒論). Result : The syndrome of soseunggitang and Soseunggitang are not corresponded with each other. The treatment of promoting production of body fluid to relax bowels is necessary for the syndrome of Soseunggitang. Conclusion : Through the analysis, I have the following conclusions. Jeungaegseunggitang(增液承氣湯) is more suitable for the syndrome of soseunggitang. Soseunggitang is suitable for disease accompanied by interior heat and dampness.

Effect of Repeated Quenching Heat Treatment on Microstructure and Dry Sliding Wear Behaviour of Low Carbon PM Steel

  • Gural, Ahmet;Tekeli, Suleyman;Ozyurek, Dursun;Guru, Metin
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.570-571
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    • 2006
  • The mixed atomized iron powders with 0.3% graphite and 1% Ni powders were cold pressed and sintered at $1200^{\circ}C$ for 30 min under pure Ar gas atmosphere. Some of the sintered specimens were intercritically annealed at $760^{\circ}C$ and quenched in water (single quenching). The other sintered specimens were first fully austenized at $890^{\circ}C$ and water quenched. These specimens were then intercritically annealed at $760^{\circ}C$ and re-quenched in water. The experimental results showed that the wear coefficient effectively decreased in the double quenched specimen.

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Prediction of Heat-treatment Time of Black Pine Log Damaged by Pine Wilt Disease (소나무재선충병 피해를 받은 곰솔 원목의 열처리 소요시간 예측)

  • Han, Yeonjung;Seo, Yeon-Ok;Jung, Sung-Cheol;Eom, Chang-Deuk
    • Journal of the Korean Wood Science and Technology
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    • v.44 no.3
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    • pp.370-380
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    • 2016
  • The black pine logs damaged by pine wilt disease in Jeju-do were heat-treated to extend the utilization of domestic trees damaged by pine wilt disease. The heat-treatment of wood requires wood to be heated to $56^{\circ}C$ for 30 min at the core. The average moisture content and top-diameter of the black pine logs were ranged from 46% to 141% and from 180 mm to 500 mm, respectively. And the basic specific gravity and oven-dry specific gravity of the black pine logs were 0.47 and 0.52, respectively. The time required for heat-treatment at $105^{\circ}C$ temperature was ranged from 7.7 h to 44.2 h, depending on moisture content and top-diameter. The temperature distribution was used to predict the time required for heat-treatment of black pine log with various moisture contents and top-diameters using finite difference method. The thermal properties of wood including the thermal conductivity and specific heat in accordance with moisture content were calculated. Heat transfer coefficient for mixed convection in form of adding natural convection and forced convection was used for heat transfer analysis. The error between the measured and predicted values ranged from 3% to 45%. The predicted times required for heat-treatment of black pine log with 50% moisture content and 200 mm, 300 mm, and 400 mm top-diameter were 10.9 h, 18.3 h, and 27.0 h, respectively. If the initial moisture content of black pine log is 75%, heat treatment times of 13.6 h, 22.5 h, and 32.8 h were predicted in accordance with top-diameter. And if the initial moisture content of black pine log is 100%, heat treatment times of 16.2 h, 26.5 h, and 38.2 h were predicted in accordance with top-diameter. When the physical properties of logs damaged by pine wilt disease are presented, these results can be applicable to the heat-treatment of red pine and Korean pine logs as well.

studies on the induction of nuclear and cytoplasmic polyhedrosis viruses by high and low temperature treatment in the silkworm, Bombsx mori L. (고온 및 저온처리에 었어서 가잠 Virus 다각체병의 유발에 대하여)

  • 강석권
    • Journal of Sericultural and Entomological Science
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    • no.11
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    • pp.63-68
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    • 1970
  • The induction of polyhedroses in the silkworm, Bambyx mari L., was investigated treating the 5th instar larvae just after eodysis with high temperature (hot water bath at 40$^{\circ}C$ for 5 minutes or dry heat shock at 40$^{\circ}C$ for 30 minutes) and low temperature (5$^{\circ}C$ for 24 hours). The results obtained were as follows; 1. Comparing between the frequency of nuclear and cytoplasmic polyhedroses induced by cold and heat treatments (hot water bath at 40$^{\circ}C$ for 5 minutes), the induction ratio of the former is clearly less than that of the latter. But if the larvae tested with cold were left at room temperature (25$^{\circ}C$) for 30-120 minutes till the next hot water bath (40$^{\circ}C$) for 5 minutes and water bath (20$^{\circ}C$) for 5 minutes, treatments, the frequency of induced cytoplasmic polyhedrosis was more than that in the case of cold or hot water bath treatment alone. 2. The frequency of nuclear and cytoplasmic polyhedrosis induced by cold and successive heat (dry heat shock at 40$^{\circ}C$ for 30 minutes), left at room temperature (25$^{\circ}C$) ti11 the second treatment, the frequency of nuclear polyhedrosis was less than that of cytoplasmic polyhedrosis. 3. The reaction of nuclear polyhedra to stains also differs sharply from that of the cytoplasmic type. In a smear of nuclear polyhedra on a slide staining with Giemsa solution remains unstained against a stained back ground, in contrast to this, the cytoplasmic polyhedra take up stain readly.

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Formation of Indole Glucosinolates Breakdown Products during Processing Treatment in Cruciferous Vegetables (십자화과 채소의 가공처리 중 Indole Glucosinolate의 분해산물 형성)

  • Shim, Ki-Hwan;Kang, Kap-Suk;Sung, Nack-Kie;Seo, Kwon-Il;Moon, Ju-Seok
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.21 no.1
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    • pp.49-53
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    • 1992
  • The released amount of thiocyanate ion in Cruciferous vegetables treated by wet heat, increased as the reaction time goes by and was maximum value after treatment for 30min, but it was not changed by dry heat treatment. When samples were autolyzed by myrosinase, the amount of thiocyanate ion increased gradually as time goes by, was maximum value after 3hrs and much higher than those in the sample treated by wet. The released amount of thiocyanate ion in each sample showed much in cabbage, Chinese cabbage, radish, kale and mustard in the order. The generated amount of indoleacetonitrile by heat treatment increased as time goes by and the generated amount in each sample determined was high in the order of cabbage, Chinese cabbage and radish.

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Case Report of Unspecified Tremor with Xerostomia Resulting from Psychometric Drug Intake Treated by Traditional Korean Medicine (한방치료로 호전된 상세불명의 떨림과 동반된 정신과계통 약물유발성 구강건조증 치험 1례)

  • Jung, Yu-jin;Kim, Minserh;Hong, Sang-hoon
    • The Journal of Internal Korean Medicine
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    • v.39 no.5
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    • pp.914-928
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    • 2018
  • Objectives: This case report examines the effects of traditional Korean medicine for unspecified tremor with xerostomia caused by psychometric drug intake. Methods: A patient who suffered from unspecified tremor with xerostomia caused by psychometric drug intake was treated with acupuncture, pharmacopuncture, and traditional Korean medicine for 30 days. We provided the patient with herbal medicines including Ondam-tang-gagam (溫膽湯加減), Pumsimgieum-gagam (忿心氣陰加減), and Hoichunyanggyeok-san-gami (回春凉隔散加味). Symptoms were charted and evaluated using the Yin-deficiency questionnaire score, Yin-deficiency scale score, dry mouth symptom questionnaire, and visual analogue scale. Results: After treatment with Korean Medicine and pharmacopuncture, the frequency and degree of tremor has decreased, and degree of Xerostomia also improved. The Scores of Yin-deficiency questionnaire score, Yin-deficiency scale score, dry mouth symptom questionnaire, and visual analogue scale were also improved. And we could see reduction in the level of distribution of gastrointestinal heat at Digital Infrared Thermal Imaging test. The patient's Symtoms (Xerostomia as well as unspecified tremor) were improved after treated with Korean Medicine and pharmacopuncture. Conclusion: Korean medicine treatments may be valuable for xerostomia caused by psychometric drug intake.

Effects of dietary inactivated probiotics on growth performance and immune responses of weaned pigs

  • Kang, Joowon;Lee, Jeong Jae;Cho, Jin Ho;Choe, Jeehwan;Kyoung, Hyunjin;Kim, Sung Hun;Kim, Hyeun Bum;Song, Minho
    • Journal of Animal Science and Technology
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    • v.63 no.3
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    • pp.520-530
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    • 2021
  • This experiment was performed to verify whether dietary heat-killed Lactobacillus rhamnosus (LR) improves growth performance and modulates immune responses of weaned pigs. Ninety-six weaned pigs ([Landrace × Yorkshire] × Duroc; 6.95 ± 0.25 kg body weight [BW]; 28 d old) were randomly allocated to four treatments: 1) a basal diet without heat-killed LR (CON), 2) T1 (CON with 0.1% heat-killed LR), 3) T2 (CON with 0.2% heat-killed LR), and 4) T3 (CON with 0.4% heat-killed LR). Each treatment had six pens with four pigs (6 replicates per treatment) in a randomized completely block design. The heat-killed LR used in this study contained 1 × 109 FU/g of LR in a commercial product. Pigs were fed each treatment for four weeks using a two-phase feeding program to measure growth performance and frequency of diarrhea. During the last week of this study, all diets contained 0.2% chromic oxide as an indigestible marker. Fecal sampling was performed through rectal palpation for the consecutive three days after the four adaptation days to measure apparent total tract digestibility (ATTD) of dry matter, crude protein, and gross energy (GE). Blood sampling was also performed on day 1, 3, 7, and 14 after weaning to measure immune responses such as serum tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1), C-reactive protein (CRP), and cortisol. The heat-killed LR increased (p < 0.05) growth rate, feed efficiency, and ATTD of GE for overall experimental period compared with CON, but reduced (p < 0.05) post-weaning diarrhea. In addition, pigs fed diets contained heat-killed had lower concentrations of serum TNF-α (d 7; p < 0.05), TGF-β1 (d 7; p < 0.10), and cortisol (d 3 and 7; p < 0.05) than pigs fed CON. In conclusion, dietary heat-killed LR improved growth rate, modified immune responses of weaned pigs, and alleviated post-weaning diarrhea.

The Effects of Dietary Turkish Propolis and Vitamin C on Performance, Digestibility, Egg Production and Egg Quality in Laying Hens under Different Environmental Temperatures

  • Seven, Pinar Tatli
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.8
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    • pp.1164-1170
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    • 2008
  • In this study, the effects of propolis and vitamin C (L-ascorbic acid) supplementation in diets were investigated on feed intake (FI), body weight (BW), body weight gain (BWG), feed conversion rate (FCR) and digestibility and on egg production and qualities (weight, mortality, shell thickness) in laying hens exposed to heat stress. A total of 150 Hyline White Leghorn, aged 42 weeks, hens was divided into five groups of 30 hens. Chicks were randomly divided into 1 positive control, 1 control and 3 treatment groups. The chicks were kept in cages in temperature-controlled rooms at $22^{\circ}C$ for 24 h/d (positive control, Thermoneutral, TN group) or $34^{\circ}C$ for 9 h/d from 08.00-17.00 h followed by $22^{\circ}C$ for 15 h (control, heat stress, HS group) and fed a basal diet or basal diet supplemented with vitamin C (250 mg/kg of L- ascorbic acid/kg of diet) or two levels of propolis (2 and 5 g of ethanol extracted propolis/kg of diet). Increased FI (p<0.05) and improvement in FCR (p<0.05), hen day egg (p<0.05) and egg weight (p<0.05) were found in Vitamin C and propolis-supplemented laying hens reared under heat stress conditions. Mortality rate was higher in the control group than TN, vitamin C and propolis groups (p<0.05). Digestibility of dry matter, organic matter, crude protein and ether extract improved with increasing of both dietary vitamin C and propolis (p<0.05). Vitamin C or propolis supplementation did not affect either the percentage shape index, yolk index or haugh unit and albumen index (p>0.05). However, the egg shell thickness and egg shell weight appeared to be increased in Vitamin C and propolis groups in comparison to HS group birds (p<0.05). In conclusion, dietary supplementation of laying hens with anti-oxidants (vitamin C and propolis) can attenuate heat stress-induced oxidative damage. These positive effects were evidenced by increased growth performance and digestibility, improvement of egg shell thickness and egg weight in comparison to non-supplemented birds. Moreover, supplementation with propolis (5 g/kg diet) was the most efficient treatment.