• Title/Summary/Keyword: cold treatment

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Analysis of Rate Equation for Spherodization of Cold Rolled Lamellar Pearlite Structure (가공된 층상조직의 구상화 속도의 해석)

  • Wey, Myeong Yong
    • Journal of the Korean Society for Heat Treatment
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    • v.4 no.2
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    • pp.1-8
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    • 1991
  • The spheroidization of cold rolled lamellar pearlite in annealing at the temperatures between 600 and $700^{\circ}C$ has been studied by quantitative micrography. It was foud that the spheroidization proceeded as two stageh. The first stage was the stage of relieving the stored energy by cold work, the second was the stage of reducing the interface energy between ferrite and cementite. The spheroidization rate combining the spheroidization rate of each stages is described by the following equation : $$d(1/S)/dt=k_3{\cdot}D/_{(1/s)}\{{\sigma}V/_{(1/s)}+k_4{\cdot}{\exp}(-bt)\}$$ Where, S is the total area of the interface between ferrite and cementite per unit volume, D is the diffusion coefficient, ${\sigma}$ is the boundary energy, V is the volume fraction of the cementite, and $k_3$, $k_4$, b are constants.

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Biological Activities of Bamboo Leaf and Quality Characteristics of Buckwheat Cold Noodle Using Bamboo Leaf Powder as a Functional Ingredient (죽엽의 생리활성 및 죽엽분말 첨가 냉면의 제조)

  • Oh Hae Sook
    • Korean journal of food and cookery science
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    • v.20 no.5
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    • pp.498-504
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    • 2004
  • This study was conducted to determine the usefulness of bamboo leaf powder as a functional ingredient for buckwheat cold noodles. The anti oxidative and fibrinolytic activities of bamboo leaf powder were very high, and were further maintained or improved after strong heat treatment. We prepared buckwheat cold noodles using 0%, 3% or 5% of bamboo leaf powder. Only the cohesiveness of the noodle having 5% bamboo leaf powder was lower than that of the noodles contained 0% and 3% bamboo leaf powder. The L-, a- and b-values were significantly different between noodles which contained bamboo leaf powder and those which did not. Nevertheless, the amount of bamboo leaf powder didn't affect the color parameters of buckwheat cold noodles. According to sensory evaluation, the addition of bamboo leaf powder improved the score of color and texture of buckwheat cold noodles, but overall acceptance was not significantly affected. Cooked volume, cooking loss and turbidity of buckwheat cold noodle containing 5% bamboo leaf powder were lower than the others, indicating that adding 5% bamboo leaf powder prevented the softening of the noodles with moist heat. We concluded that the application of bamboo leaf for the production of buckwheat cold noodle will be a good way to intake the biologically active ingredients for good health.

A Case Series of Cold Hypersensitivity in Hands and Feet in Soyangin Cold Pattern Patients (수족냉증을 호소하는 소양인 비수한표한병 환자의 증례보고 7례)

  • Jiyeon Lee;Minwoo Hwang
    • Journal of Sasang Constitutional Medicine
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    • v.35 no.3
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    • pp.12-28
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    • 2023
  • Introduction This study reports case series of Soyangin patients with coldness in hands and feet using Sasang constitutional medicine approach. This study suggests a value of using constitutional medicine indicators as both prognostic and diagnostic tools. Methods Among patients who visited an outpatient clinic, 7 patients were selected based on the criteria. These selected patients were exclusively treated with herbal medicine and monitored every 2 to 4 weeks retrospectively. Results The average treatment period was 8 weeks. Patients with a favorable pattern showed the improvement within 8 weeks, while those with an unfavorable pattern required more time. Discussion This study confirms the significance of Sasang constitutional medicine approach in Soyangin exterior cold syndrome with coldness in hands and feet. It also validates the current coldness in hands and feet as meaningful diagnostic indicator of Soyangin exterior cold syndrome. Furthermore, it highlights the value of original symptoms as prognostic tools.

Microstructure and Mechanical Properties of AA6061/AA5052/AA6061 Complex Sheet Fabricated by Cold-Roll Bonding Process (냉간압연접합법에 의해 제조된 AA6061/AA5052/AA6061 복합판재의 미세조직 및 기계적 성질)

  • Hwang, Ju-Yeon;Lee, Seong-Hee
    • Korean Journal of Materials Research
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    • v.29 no.6
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    • pp.392-397
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    • 2019
  • A cold roll-bonding process is applied to fabricate an AA6061/AA5052/AA6061 three-layer clad sheet. Two AA6061 and one AA5052 sheets of 2 mm thickness, 40 mm width, and 300 mm length are stacked, with the AA5052 sheet located in the center. After surface treatment such as degreasing and wire brushing, sample is reduced to a thickness of 1.5 mm by multi-pass cold rolling. The rolling is performed at ambient temperature without lubricant using a 2-high mill with a roll diameter of 400 mm at rolling speed of 6.0 m/sec. The roll bonded AA6061/AA5052/AA6061 complex sheet is then hardened by natural aging(T4) and artificial aging(T6) treatments. The microstructures of the as-roll bonded and age-hardened Al complex sheets are revealed by optical microscopy; the mechanical properties are investigated by tensile testing and hardness testing. After rolling, the roll-bonded AA6061/AA5052/AA6061 sheets show a typical deformation structure in which grains are elongated in the rolling direction. However, after T4 and T6 aging treatment, there is a recrystallization structure consisting of coarse equiaxed grains in both AA5052 and AA6061 sheets. The as roll-bonded specimen shows a sandwich structure in which an AA5052 sheet is inserted into two AA6061 sheets with higher hardness. However, after T4 and T6 aging treatment, there is a different sandwich structure in which the hardness of the upper and lower layers of the AA6061 sheets is higher than that of the center of the AA5052 sheet. The strength values of the T4 and T6 age-treated specimens are found to increase by 1.3 and 1.4 times, respectively, compared to that value of the starting material.

Microstructure and Mechanical Properties of Cold Roll-Bonded Layered AA6061/AA5052/AA6061/AA5052 Aluminum Alloy Sheet (냉간압연접합된 층상 AA6061/AA5052/AA6061/AA5052 알루미늄합금판재의 미세조직 및 기계적 성질)

  • Jo, Sang-Hyeon;Park, Bo-Bae;Lee, Seong-Hee
    • Korean Journal of Materials Research
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    • v.32 no.3
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    • pp.161-167
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    • 2022
  • A cold roll-bonding process is applied to fabricate an AA6061/AA5052/AA6061/AA5052 layered sheet. Two AA6061 and one AA5052 sheets of 2mm thickness, 40mm width and 300mm length are alternately stacked, then reduced to a thickness of 2.0 mm by multi-pass cold rolling after surface treatment such as degreasing and wire brushing. The rolling is performed at ambient temperature without lubricant using a 2-high mill with a roll diameter of 400 mm at a rolling speed of 6.0 m/sec. The roll-bonded AA6061/AA5052/AA6061/AA5052 layered sheet is then hardened by natural aging (T4) and artificial aging (T6) treatments. The microstructure of the as-roll bonded and the age-hardened Al sheets was revealed by SEM observation; the mechanical properties were investigated by tensile testing and hardness testing. After T4 and T6 aging treatment, the specimens had a recrystallization structure consisting of coarse equiaxed grains in both AA5052 and AA6061 regions. The as-roll-bonded specimen showed a clad structure in which the hardness of AA5052 regions was higher than that of AA6061 regions. However, after T4 and T6 aging treatment, specimens exhibited different structures, with hardness of AA6061 regions higher than that of AA5052 regions. Strengths of T6 and T4 age-treated specimens were found to increase by 1.55 and 1.36 times, respectively, compared to the value of the starting material.

Seed Dormancy and Germination Characteristics of Endemic Elder Species (Sambucus racemosa subsp. pendula) and Common Elder Species (S. williamsii) in Korea

  • Hyo-In, Lim
    • Journal of Forest and Environmental Science
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    • v.38 no.4
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    • pp.284-289
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    • 2022
  • This study was conducted to determine the seed dormancy types of Sambucus racemosa subsp. pendula Nakai and S. williamsii Hance. Low temperature stratification (1, 2, 3, 4 months) and GA3 treatment (1,000 mg/L) were performed on seeds to determine the type of seed dormancy. After the treatment, seeds were placed on a petri dish at 25℃ under light conditions. The germination rate and mean germination time were investigated. Results showed that cold stratification was effective in breaking the dormant state of the seed in both species. In the low temperature stratification treatment, the seed germination performance was improved as the treatment period was prolonged. Gibberellin treatment was effective in breaking the dormant state of S. racemosa subsp. pendula without low temperature stratification. However, S. williamsii did not break the dormant state of the seed by gibberellin treatment without low temperature stratification treatment. In the gibberellin treatment, germination performance was improved according to the low temperature stratification treatment period. As a result of this study, the seeds of S. williamsii have both an intermediate complex and a deep complex morphophysiological dormancy (MPD). In comparison, it was found that the S. racemosa subsp. pendula had intermediate composite MPD.

Effect of Passive Temperature Therapy of the Femoral Muscles on the Countermovement Jump Performance

  • Lee, Jintaek;Panday, Siddhartha Bikram;Byun, Kyungseok;Lee, Jusung;Hwang, Jinny;Moon, Jeheon
    • Korean Journal of Applied Biomechanics
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    • v.29 no.4
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    • pp.227-235
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    • 2019
  • Objective: The purpose of this study was to evaluate the effect of passive-acute temperature therapy of the femoral muscle and dynamic warm-up on the countermovement jump performance. Method: Twenty male track and field athletes from national team underwent three treatments applied on the femoral muscles; cold temperature treatment, thermal treatment and dynamic warm-up. The variables extracted at 2 time points (pre-measurement and post measurement) were the temperature of the left and right femoral muscle, displacement & velocity of centre of mass, peak power out, range of motion and moment & power of the knee joint. Results: There was a statistically significant difference in the temperature of the femoral muscle according to measurement time which was high in the order of thermal treatment, dynamic treatment and cold treatment. The jump height was the highest in the dynamic warm-up with no statistically significant difference for the range of motion of the knee joint. The peak power out at dynamic warm-up and the power of the knee joint were statistically significant according to the treatment and measurement time. Conclusion: Local cold and thermal treatment of femoral muscles at ambient temperature did not improve jump performance, while dynamic warm-up was considered to be effective for maintaining the performance of the activities that require strong muscular power.

Hydrodynamic Characteristics of the Rectangular Type Circulating Fluidized Bed (4각 순환유동층의 수력학적 특성)

  • Hyun, Sang Yeol;Rhee, Kwan Seok
    • Journal of the Korean Society for Heat Treatment
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    • v.10 no.4
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    • pp.232-236
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    • 1997
  • A rectangular type circulating fluidized bed (CFB) with an internal nozzle and two partition walls was proposed. In this modified CFB, an internal nozzle and two slanted partition walls were additionally set in the riser. This cold mode apparatus was made of acrylic resin; the riser was 1500mm high and $1000{\times}1000mm^2$ in the cross sectional area, the internal nozzle was 200mm high and 10mm in the inner diameter, and the partition wall was 7mm thick. Glass beads of $91{\mu}m$ in the mean diameter were employed as bed materials. In the cold mode by using the proposed CFB with an internal nozzle, it was possible to change the particle hold up by changing the gas flow ratio of the nozzle to the total(Qn/Qt). It was found that the inflection point which devided the bed structure between the dense and the dilute phase in the riser varied with Qn/Qt.

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The literature study on classification of cause and the effect of Acupuncture and Moxibustion treatment for Youk Jeol Poung (역절풍(歷節風)의 병인병기(病因病機)와 침구치료(鍼灸治療)에 관(關)한 문헌적(文獻的) 고찰(考察))

  • Yuh, Bok-Jong;Kim, Gi-Hyun
    • Journal of Haehwa Medicine
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    • v.9 no.1
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    • pp.443-459
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    • 2000
  • The Literatural Study on the classification of cause and the effect of Acupuncture and Moxibustion treatment for Youk Jeol Poung was studied from the viewpoint of therapeutic acupuncture and moxibustion effect. And the results were as follows: 1. Youk Jeol Poung is similar to Tong Bi, Ju Bi, Haeng Bi, Tong Poung. 2. The symptoms of Youk Jeol Poung are pain and weakness, difficulty of flexion, swelling and pain, severe pain etc., at night pain is more severe. 3. The cause, mechanism of Youk Jeol Poung is as follow, due to penetration of the wind, cold, moisture, uder situation of whole body is pain. 4. The main treatment is invigorate vital energy and blood, expel wind - evil, promote diuresis, eliminating phlegm, promote blood circulation, cold, heat - clearing. 5. The basal meridian of acupuncture and moxibustion treatment were the channels of Su Jok Sam Yang.

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Effect of cold working and stabilizing treatment on the fatigue properties of aluminum alloy 5083 (알루미늄합금판재(Al5083)의 피로특성에 미치는 냉간압건량과 안정화처리의 영향)

  • 이재순;오택열;박경순
    • Journal of the korean Society of Automotive Engineers
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    • v.5 no.2
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    • pp.31-40
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    • 1983
  • A study was made of the effect of cold working and stabilizing temperature on the fatigue properties of Aluminum alloy 5083. The amount of cold working ranged from 14% to 35% and stabilizing temperature was 120.deg. C-160.deg. C. Rotary bending fatigue test was carried out, and it was found that 1) E specimen that had been cold worked by the cold reduction of 35% and stabilized at 160.deg. C for 2 hours was showed the most excellent fatigue limit and endurance ratio and, 2) By the results of the between crack propagation behavior and stress intensity factor, E specimen was showed the better resistance to fatigue crack growth than others.

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