• Title/Summary/Keyword: cold-stress

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Effect of Moisture Content on Viscosity of Starch Dough (전분반죽의 점도에 미치는 수분함량의 영향)

  • Lee, Boo-Yong;Lee, Chang-Ho;Lee, Cherl-Ho
    • Korean Journal of Food Science and Technology
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    • v.27 no.4
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    • pp.582-592
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    • 1995
  • To measure rheological properties of the starch dough, an Extrusion Capillary Viscometer(ECV) cell was self-made and attached to Instron machine(Model 1140). Apparent viscosities of corn and waxy corn starch doughs were measured and their gelatinization degrees were determined by enzymatic analysis. When corn and waxy corn starch doughs with $36{\sim}52%$ moisture content were heated at $60{\sim}100^{\circ}C$, come-up time of the cold point of doughs decreased from 220 sec to 140 sec with increased in the moisture content. In the measurement range of $36{\sim}52%$ moisture content and $60{\sim}100^{\circ}C$ heating temperature, both corn and waxy corn starch doughs showed pseudoplastic flow behaviors. At the same shear rate, both shear stress and viscosity of starch dough decreased as the moisture content increased. At the moisture content above 44%, the shear stress and viscosity of starch dough decreased as the heating temperature increased from $60^{\circ}C\;to\;70^{\circ}C$, but increased as the heating temperature increased from $80^{\circ}C\;to\;100^{\circ}C$. When the moisture content increased and heating temperature, the gelatinization degree of starch dough increased from about 10% to about 62%. The gelatinization degree of waxy corn starch dough was $15{\sim}20%$ higher than that of corn starch dough under the same gelatinization conditions. The effects of moisture content on the viscosity of starch dough were examined by Arrhenius equation. As the moisture content increased, viscosity of starch dough decreased. But the effect of moisture content was greater in the range of $80{\sim}100^{\circ}C$ than in the range of $60{\sim}70^{\circ}C$ heating temperature.

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Mechanical Properties and Stress-Strain Model of Re-Bars Coldly Bent and Straightened (굽힌 후 편 철근의 기계적 성질과 응력-변형률 모델)

  • Chun, Sung-Chul;Tak, So-Young;Ha, Tae-Hun
    • Journal of the Korea Concrete Institute
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    • v.24 no.2
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    • pp.195-204
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    • 2012
  • In the construction of high-rise buildings, bent re-bars are manually straightened to connect slabs to core-walls, which are usually cast before floor structures. During cold bending and straightening of re-bars, plastic deformation causing work hardening, Bauschinger effect and aging hardening is unavoidable. Tensile tests of coldly bent and straightened re-bars were conducted with test parameters of grade, diameter, and bend radius of re-bars as well as age between bending and straightening. Test results showed that proportional limits were lower and strain hardening occurred without yield plateaus. Inside and outside of re-bars with compression and tension deformations, respectively, during bending showed lower yield points due to Bauschinger effect and no yield plateaus due to work hardening, respectively. When re-bar grade was higher, yield point became significantly lower where Grade 400 re-bars had yield strengths lower than specified yield strength of 400 MPa. Because the surface of re-bar has higher strength than the core of re-bar, Bauschinger effect was more obvious for higher-grade re-bars. When age between bending and straightening was greater, yield strength increased and elongation decreased (i.e. embrittlement occurs). Using measured data, stress-strain relationship for straightened re-bars was developed based on Ramberg-Osgood model, which can be used to evaluate stiffness of joints when straightened re-bars are applied.

A Clinical study on 80 Cases of Alopecia Patients in the Oriental Medicine Clinic (한의원에 내원한 탈모증 환자 80명의 임상적 고찰)

  • Lee, Seung-Min;Yi, Tae-Hoo;Keum, Dong-Ho
    • Journal of Korean Medicine Rehabilitation
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    • v.15 no.2
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    • pp.141-154
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    • 2005
  • Objectives : This study was planned to evaluate clinical status of the alopecia patients who had visited oriental medicine clinic. Methods : 80 patients with alopecia, who had visited oriental medicine clinic from January 2004 to August 2004, were examined. Results & Conclusions : 1. The kinds and incidences of Alopecia : androgenetic alopecia 57.5%(46/80), alopecia areatea 20.0%(16/80), telogen effluvium 16.3%(13/80), seborrheic alopecia 6.3%(5/80). 2. In distribution of sex, the rate of male to female was 1:1 and most patients belonged to 20-30 year old group. 3. The most common onset of age was adolescence(63.8%) and the most common duration of hair loss was 1 to 3 years. 4. Among the 30 male androgenetic alopecia patients, Hamilton's type 4 was most common and among the 16 female androgenetic alopecia patients, Ludwig's type II and III were most common. 5. Family history of baldness in Androgenetic alopecia and alopecia areata were 56.5% and 25.0%, respectively. 6. Self-conscious causes of hair loss : stress(48.8%), irregular eating habits(21.3%), and lack of sleep(20.0%). 7. Associated diseases with alopecia patients : chronic neck pain(58.8%), temporomandibular disorders(55.0%) and seborrheic dermatitis(20.0%). 8. Associated symptoms with alopecia Patients : stress(78.8%), sleep disorders(68.8%), irregular eating habits(55.0%), Hot flush(43.8%), Stool disorders(43.8%), cold hands and feet(37.5%) and menstruation disorders(31.3%). 9. The most common scalp type was oily scalp(70.0%) and the symptoms of scalp were iching, dandruff, pain, inflammation. 10. $Bi{\grave{a}}n$ $zh{\grave{e}}ng$(辨證) of alopecia patients : $xu{\grave{e}}-r{\grave{e}}-f{\bar{e}}ng-z{\grave{a}}u$(血熱風燥) (25.0%), $g{\bar{a}}n-sh{\grave{e}}n-b{\grave{u}}-z{\acute{u}}$(肝腎不足) (23.8%), $shi-r{\grave{e}}-sh{\grave{a}}ng-zh{\bar{e}}ng$(濕熱上蒸) (16.3%), $xu{\grave{e}}-r{\grave{e}}-sh{\bar{e}}ng-f{\bar{e}}ng$(血熱生風) (13.8%), $xu{\grave{e}}-x{\bar{u}}-f{\bar{e}}ng-z{\grave{a}}u$(血熱風燥) (13.8%), $y{\bar{u}}-xu{\grave{e}}-z{\check{u}}-lu{\grave{o}}$(瘀血阻絡) (7.5%).

Ocean Surface Winds Over the Seas Around Korea Measured by the NSCAT(NASA Scatterometer) (NSCAT (NASA Scatterometer)에 의한 한국근해의 해상풍)

  • 이동규
    • Korean Journal of Remote Sensing
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    • v.14 no.1
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    • pp.37-52
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    • 1998
  • The NSCAT(NASA Scatterometer) carried by the japanese Advanced Earth Observing Satellite(ADEOS) was the first high resolution(25 km) device for the direct wind measurement over the ocean. Even it was ceased to operate in lune of 1977 because of the power failure, it gave the first opportunity to the marine meteorologists to study the direct measured ocean wind during its 9 months of operation, especially around Korea. This study is to show monthly mean ocean wind and wind stress curl fields around Korea from January, 1997 to June, 1997. Mean ocean winds in January are predominantly northwesterly and the strongest wind(12 m/s) is found near Vladivostok. The winds in the western East Sea are strongly inf1uenced by the mountain range in Korea and these topographically influenced winds make about five times larger wind stress curl fields than previous estimates based on the weather maps. The calculation of Sverdrup transport in the East Sea shows the possibility of the directional change of the East Korean Cold Current from southward to northward direction caused by the winter wind. The downwelling area near North Korea has maximum estimated speed of 45 m in january and this wind induced downwelling makes good condition for the formation of Intermediate East Sea Water together with vigorous mixing by the strong wind.

Evaluation of Mechanical Performance Considering Prolonged Length of Glass Fiber-Reinforced Composite on Structure Weakness by Thermal Stress at Secondary Barrier in Cryogenic Liquified Gas Storage (극저온 액화가스 화물창 2차방벽 구조 열 응력 취약 부 Prolonged 길이 고려 유리섬유 강화 복합재 기계적 물성 평가)

  • Yeon-Jae Jeong;Hee-Tae Kim;Jeong-Dae Kim;Jeong-Hyun Kim;Seul-Kee Kim;Jae-Myung Lee
    • Composites Research
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    • v.36 no.4
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    • pp.246-252
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    • 2023
  • A secondary barrier made of glass fiber reinforced composites has been installed infinitely using automatic bonding machine(ABM) in membrane type LNG cargo containment system (CCS). At the same time, significant thermal stress due to cryogenic heat shrinkage has occurred in the composite on the non-bonding area between the adhesive fixation at both ends. There have been studies from the perspective of structural safety evaluation taking this into account, but none that have analyzed mechanical property taking an prolonged length into account. In this study, 2-parameter Weibull distribution statistical analysis was used to standardize reliable mechanical property for actual length, taking into account the composite's brittle fracture of ceramic material with wide fracture strength dispersion. Related experimental data were obtained by performing uniaxial tensile tests at specific temperatures below cryogenic condition considering LNG environment. As a result, the mechanical strength increased about 1.5 times compared to -20℃ at -70℃ and initial non-linear behavior of fiber stretched was suppressed. As the temperature decreased until the cryogenic, the mechanical strength continued to increase due to cold brittleness. The suggested mechanical property in this study would be employed to secure reliable analysis support material property when assessing the safety of secondary barrier's structures.

An Analysis Method on Injury Symptoms Utilizing Infrared Thermal Imaging under the Freezing Stress of Hedera helix L. (헤데라 헬릭스 식물의 적외선 열영상에 의한 저온 및 한풍피해에 관한 연구)

  • Seong, Bu-Geun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.6
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    • pp.173-179
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    • 2012
  • The experiments, which analyze the injury symptoms and diagnose growth conditions utilizing IRVT and analyzing each parts of H. helix L., had been held under a low temperature. Greenhouse and outdoor growing Genus hedera had been prepared and compared with each Genus hedera's peak and bottom leaves' surface temperature under the experimental categories $-6^{\circ}C$ and $-12^{\circ}C$. As results, analyzing the surface thermal property of peak part leaves' of outdoor growing Genus hedera, at experimental categories $-6^{\circ}C$, $-12^{\circ}C$ were ranged from $-2^{\circ}C{\sim}-7^{\circ}C$ and $-2^{\circ}C{\sim}-15^{\circ}C$. On the other hand, the surface thermal property of bottom part leaves at experimental categories $-6^{\circ}C$, $-12^{\circ}C$ were ranged $-2^{\circ}C{\sim}-11^{\circ}C$ and $-1^{\circ}C{\sim}-12^{\circ}C$. It appears that the thermal properties of leaves' surface on $-6^{\circ}C$ peaks and $-12^{\circ}C$ bottoms were more broadband than bottoms and peaks. It means that the peaks were more sensitive than bottoms, as like $-2^{\circ}C{\sim}-15^{\circ}C$, $-1{\sim}-12^{\circ}C$. Moreover, as similar results had seen to leaves surface temperature added to cold wind conditions. How the cold wind damaged the outdoor growing Genus hedera, analyzed the surface thermal property by IRVT data under $0^{\circ}C$, $-2^{\circ}C$, $-4^{\circ}C$ condition, it resulted to $-6.2^{\circ}C$, $-6.8^{\circ}C$, $-7.5^{\circ}C$. It appeared more $3.5{\sim}6.2^{\circ}C$ low temperature than experimental setting point. In addition, each parts thurmal property of peaks and bottoms was not similar, it referred to each parts' sensitivities of low temperature were different on the peak and bottom leaves surface temperature.

Study on the Genetic Characteristics of Waterlogging Tolerant Pepper (Capsicum annuum L.) for Breeding Tolerant Varieties against Flooding Stress (내습성 고추 품종 육성을 위한 선발계통의 유전적 특성 구명)

  • Yang, Eun Young;Chae, Soo-Young;Hong, Jong-Pil;Lee, Hye-Eun;Park, Eun Joon;Moon, Ji-hye;Park, Tae-Sung;Roh, Mi-Young;Kim, Ok Rye;Kim, Sang Gyu;Kim, Dae Young;Lee, Sun Yi;Cho, Myeong Cheoul
    • Journal of Life Science
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    • v.27 no.10
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    • pp.1111-1120
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    • 2017
  • This study was conducted to select pepper lines that were tolerant to excessive water injury among the pepper germplasm and investigate the genetic characteristics of those lines to contribute to the breeding of pepper cultivars with stable productivity in abnormal weather. Each of the tolerant and susceptible lines went through immersion treatment, and differentially expressed genes between them were analyzed. The tolerant line showed increased expression of the CA02g26670 gene, which is involved in the CONSTANS protein pathway and regulation of flowering by day length, but it exhibited decreased expressions of CA01g21450, CA01g22480, CA01g34470, CA02g00370 and CA02g00380. The susceptible line showed increased gene expressions of CA02g09720, CA02g21290, CA03g16520, CA07g 02110, and CA12g17910, which are involved in the inhibition of proteolytic enzyme activity, DNA binding, inhibition of cell wall-degrading enzyme, and inhibition of nodulin, respectively. Meanwhile the expressions of CA02g02820, CA03g21390, CA06g17700 and CA07g18230 decreased in the susceptible line, in relation to calcium-ion binding, high temperature, synthesis of phosphocholine and cold stress, respectively. The expressions of genes related to apoptosis and peroxidase increased, while that of CA02g16990, which functions as a nucleoside transporter, decreased in both the tolerant and susceptible lines. Based on the different gene expressions between the tolerant and susceptible lines, further studies are needed on breeding abiotic stress-tolerant lines.

Inter-ramet Physiological Integration Detected in Buffalograss(Buchloe dactyloides (Nutt.) Engelm.) under Water Stress (수분스트레스 하에 있는 버팔로그래스에서 검출된 무성생식체의 생리학적 조정)

  • Qian, Yongqiang;Li, Deying;Han, Lei;Ju, Guansheng;Liu, Junxiang;Wu, Juying;Sun, Zhenyuan
    • Asian Journal of Turfgrass Science
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    • v.23 no.2
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    • pp.331-344
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    • 2009
  • Buffalograss is an important turfgrass species with excellent cold, heat, and drought tolerance. Understanding the physiological integration of buffalograss under heterogeneous conditions helps to develop cultural practices that better use limited resources for uniform turf quality. The objective of this study was to evaluate physiological integration of buffalograss under water deficit stress and the involvement of lipid peroxidation and antioxidants in the process. In one experiment, buffalograss was planted in the center of a four-compartment growth unit. Watering frequencies, once a week(+) and once in two weeks(-), were combined with the sand(S) or peat(P) in each unit to generate five total treatments(P+S-P-S+, P+P+P+P+, S-S-S-S-, P-P-P-P-, and S+S+S+S+). The average number of shoot established from the heterogeneous root-zone medium was higher than the average of four possible homogeneous media. In second experiment, single ramet in Hoagland solution($S_0$) or single ramet in Hoagland solution with 20% PEG-6000($S_s$) were compared with two connectedramets under different treatments. Treatments for connected ramets were young ramet in Hoagland solution($Y_{os}$) and old ramet in Hoagland solution with 20% PEG-6000($O_{os}$), and old ramet in Hoagland solution($O_{ys}$) and young ramet in Hoagland solution with 20% PEG-6000($Y_{ys}$). Lipid peroxidation, antioxidants, and proline showedphysiological integration between ramets subjected to different levels of water stress. Superoxide dismutase(SOD), Guaiacol peroxidase(G-POD), malondialdehyde(MDA), and free proline also showed different time courses and relative activities during the physiological integration.

In Vitro Hepatoprotective Effects of Fermented Curcuma longa L. by Aspergillus oryzae against Alcohol-Induced Oxidative Stress (알코올성 산화적 손상에 대한 발효울금의 간세포 보호 효과)

  • Sung, Heami;Lee, Yoo-Hyun;Jun, Woojin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.6
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    • pp.812-818
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    • 2016
  • Protective effects of fermented Curcuma longa L. (CL) against alcoholic liver damage were investigated in HepG2/2E1 cells. Fermented CL was extracted by cold water (FCC), hot water, 80% ethanol, and methanol. Of the four extracts, the strongest hepatoprotective effect against ethanol-induced oxidative stress was observed in FCC. Pretreatment with FCC also reduced intracellular reactive oxygen species formation compared to ethanol-alone treated cells. FCC also enhanced catalase, glutathione-S-transferase, glutathione reductase, glutathione peroxidase, and superoxide dismutase, and non-enzymatic antioxidative activities such as glutathione compared to alcohol-treated HepG2/2E1 cells. Our findings suggest that FCC might be considered as a useful agent in the prevention of liver damage induced by oxidative stress by increasing the antioxidant defense mechanism.

Comparative Clinical Study between Oriental Medicine and Oriental-western Medicine Treatment on Facial Nerve Paralysis (구안와사(口眼喎斜)에 대한 한의(韓醫) 및 한(韓)·서의(西醫) 협진(協診) 치료(治療)의 임상(臨床) 관찰(觀察))

  • Kang, Mi-Jung;Kim, Kee-Hyun;Hwang, Hyeon-Seo
    • Journal of Acupuncture Research
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    • v.17 no.1
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    • pp.55-66
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    • 2000
  • The following results have been obtaind after examing 72patients with facial paralysis who were hospitalzed and treated through the time period of December 1st, 1996 to November 30th, 1999 at the Department of Acupuncture and Moxibustion of Seoul Oriental Medicine, Kyungwon University. During the examination, those 72 patients were divided into two groups, and One group was treated by oriental-western treatment, the other group was treated by oriental treatment. Oriental treatments were acupuncture and moxibustion, herb medicine, physical treatment and hygienic treatment. The one of main western treatments is steroid therapy. The results were obtained as follows : 1. In regard to signs at the first medical examination, lacrimation was showed highest number and facial paralysis, dysgeusia, hyperacusis were showed in numerical order. 2. In regard to prescription of oriental herb medicine, Kamissangbotang(加味雙補湯) was prescribed in greatest numbers and Boyangwhanotang(補陽還五湯), Kamiboiktang(加味補益湯), Ligigepungtang(理氣祛風湯) were prescribed in numerical order. 3. In regard to treatment number, 10~19 times for treatment was showed highest number and 1~9 times, 20~29 times, 40~49 times were showed in numerical order . 4. In regard to mean treatment times about injury region and main sign, the effect of oriental-western treatment was showed as follows: lacrimal gland disorder, hyperacusis, dysgeusia, facial paralysis were treated for 15.1, 27, 13.2 and 21.4 times, repectively. The effect of oriental treatment was showed as follows: lacrimal gland disorder, hyperacusis, dysgeusia, facial paralysis were treated for 34.8, 22.1, 33.8 and 16.3 times, respectively. 5. In regard ta the effect of treatment about injury region and main sign, oriental-western treatment was showed as follows: cases of lacrimal gland disorder were showed 1 of excellent case, 1 of fair case, 5 of good cases. In hyperacusis patients, there was showed 1 of fair case. In dysgeusia patients, there was showed 1 of excellent case, 3 of fair cases, 1 of good case. In facial paralysis, there were showed 5 of fair cases. Oriental treatment was showed as follows: In lacrimal gland disorder, the excellent were 4 cases, the fair were 10 cases, the good were 3 cases and the poor were 4 cases, In hyperacusis, the fair were 5 cases, the poor 2 cases. In dysgeusia, the excellent were 4 cases, the fair were 1 case, the good were 1 case and the poor was 1 case, In facial paralysis, the excellent were 9 cases, the fair were 4 cases, the good 3 cases and the poor were 3 cases. 6. The effect of total treatment was as follows: 30 cases were showed fair effect, 19 cases were showed excellent effect, 13 cases were showed good effect and 10 cases were showed poor effect. 7. In regard to attack factor, overlabour was showed highest number and wind-cold, mental stress, trauma, ear disease, common cold, dental diseae, reason unknwon were showed in numerical order. 8. In regard to premonitory symptoms, non significant symptoms were in 38 cases, the pain of peri-stylomastoid region were in 38 cases and headache, dysaesthesia of periorbit, dysgeusia, stomatitis, eyelid tic were showed in numerical order. 9. In regard to sex, male were 33 cases and female were 39 cases. The distribution of age was disclosed that thirty, forty, fifty, seventy, sixty, twenty and below twenty years were revealed in turn. Sex and paralytic side were showed as follows: male-left were 15 cases, male-right were 18 cases, female-left were 19 cases and female-right were 19 cases. In regard to attack frequence in month, March was showed highest number and January, April, May, August, October, etc were showed in numerical order. In regard to attack frequence in season, spring was showed highest number and winter, summer, fall were showed in numerical order, but attack frequence between four seasons wasn't showed significant difference.

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