• 한국식품영양과학회지
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• 제38권6호
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• pp.742-749
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• 2009

총각김치의 최적 숙성을 위한 발효온도 조건 확립 및 계절별 총각김치의 품질 특성에 대한 기초자료를 제시하고자 봄, 여름, 겨울 총각김치를 저장 온도에 따른 발효 양상을 살펴보았다. 총각김치의 pH의 변화는 계절별 김치의 영향보다는 저장 온도에 따른 영향이 컸다. 총각김치의 산도 변화는 계절 및 온도의 영향을 모두 받았는데, 발효 온도가 높을수록 계절의 영향이 크게 나타났다. 발효온도 $15{\sim}20^{\circ}C$에서 저장한 봄 총각김치의 초기 산도 상승은 급격하였다. 이에 반해 여름 총각김치의 산도변화는 모든 발효 온도에서 가장 낮았는데 이는 여름무의 환원당의 함량이 가장 낮았기 때문으로 생각된다. Leuconostoc sp.와 Lactobacillus sp.의 증식은 전형적인 발효 양상을 따랐으며 $10^{\circ}C$에서 발효시킨 총각김치의 유산균의 증식이 $5^{\circ}C$에서 발효시킨 김치보다 활발한 것으로 나타났다. 총각김치의 조직감의 변화는 발효 온도보다는 계절적 영향이 큰 것으로 나타났다. 겨울 총각김치는 저장기간 중 김치의 조직감이 잘 유지되는데 반해 봄 및 여름총각김치는 담금 후 조직감이 급격히 감소하였다. 총각김치의 관능평가 중 종합적인 평가는 여름과 겨울김치가 유사하였으나 겨울 총각김치의 가식기간이 길었다. 관능검사에서 가장 높은 평가를 받은 총각김치는 $10^{\circ}C$에서 발효시킨 겨울총각김치이었다.

• The Korean Journal of Physiology
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• 제16권1호
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• pp.13-23
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• 1982

Effects of external pH and potassium concentrations on the electrical and mechanical properties were investigated on rabbit papillary muscle. Papillary muscles were perfused in horizontal chamber with Tris Tyrode solutions and action potential along with isometric tension was recorded simultaneously. Potassium concentrations were varied between 1 and 12 mM at low(6.9), normal(7.4) and high (7.9) external pH. The following results were obtained: 1) On rasing the potassium concentration from 1 to 12 mM resting membrane potentials decreased from $-88.8{\pm}2.8$ to $-66.4{\pm}1.2\;mV$ at normal pH and the amplitude of action potential decreased from $115.1{\pm}0.7$ to $97.5{\pm}2.8\;mV$. On lowering the potassium concentration, membrane hyperpolarized and at 1 mM potassium concentration resting potentials were $-107{\pm}2.2\;mV$. Duration of action potential especially $APD_{60}{\sim}APD_{90}$ increased($APD_{90}$: $214{\pm}15.8\;ms$ at 1 mM $K^+$ to $287{\pm}18.1\;ms$ at 12 mM $K^+$). 2) During acidosis membranes hyperpolarized by more than 20 mV within 1 min. and then slow recovery was observed during the following 10 min. During alkalosis membranes depolarized about 10 mV, which were maintained until washing with normal Tyrode solutions. 3) On lowering the external pH(7.9-6.5), duration of action potential increased progressively and it was most prominent at pH 6.5 and $K^+$ 1mM. 4) Magnitude of developed tension was $0.6{\pm}0.14\;g/mm^2$ at normal pH and potassium concentration (stimulus frequency : 60/min). Relative isometric tension to normal value increased along the increment of stimulus frequency($44.2{\pm}4.2%$ at 6/min to $271{\pm}86.7%$ at 180/min). Force-frequency relations were altered quantitatively during the perfusion with different external pH solutions. 5) Developed tension did not show marked variation within the range of $2{\sim}8\;mM$ potassium concentrations. Positive inotropism was observed at less than 2 mM $K^+$ and negative inotropism beyond 12 mM $K^+$ concentrations. From the above results we concluded that the effects of potassium ion concentration on electrical and mechanical properties of rabbit papillary muscle are related to the changes in surface negative charge due to acid base disturbances.

• Journal of Biosystems Engineering
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• 제25권3호
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• pp.213-220
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• 2000

Grafting of fruit-bearing vegetables has been widely used to increase the resistance to soil-borne diseases, to increase the tolerance to low temperature or to soil salinity, to increase the plant vigor, and to extend the duration of economic harvest time. After grafting, it is important to control the environment around grafted seedlings for the robust joining of a scion and rootstock. Usually the shading materials and plastic films are used to keep the high relative humidity and low light intensity in greenhouse or tunnel. It is quite difficult to optimally control the environment for healing and acclimation of grafted seedlings under natural light. So the farmers or growers rely on their experience for the production of grafted seedling with high quality. If artificial light is used as a lighting source for graft-taking of grafted seedlings, the light intensity and photoperiod can be easily controlled. The purpose of this study was to develop a prototype system for the graft-taking enhancement of grafted seedlings using artificial lighting and to investigate the effect of air current speed on the distribution of air temperature and relative humidity in a graft-taking enhancement system. A prototype graft-taking system was consisted by polyurethane panels, air-conditioning unit, system controller and lighting unit. Three band fluorescent lamps (FL20SEX-D/18, Kumho Electric, Inc.) were used as a lighting source. Anemometer (Climomaster 6521, KANOMAX), T-type thermocouples and humidity sensors (CHS-UPS, TDK) were used to measure the air current speed, air temperature and relative humidity in a graft-taking system. In this system, air flow acted as a driving force for the diffusion of heat and water vapor. Air current speed, air temperature and relative humidity controlled by a programmable logic controller (UP750, Yokogawa Electric Co) and an inverter (MOSCON-G3, SAMSUNG) had an even distribution. Distribution of air temperature and relative humidity in a graft-taking enhancement system was fairly affected by air current speed. Air current speed higher than 0.1m/s was required to obtain the even distribution of environmental factors in this system. At low air current speed of 0.1m/s, the evapotranspiration rate of grafted seedlings would be suppressed and thus graft-taking would be enhanced. This system could be used to investigate the effects of air temperature, relative humidity, air current speed and light intensity on the evaportranspiration rate of grafted seedlings.

• Journal of Animal Science and Technology
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• 제49권4호
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• pp.531-538
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• 2007

본 연구는 소, 돼지, 닭의 부산물인 신장, 간, 기관으로부터 황산콘드로이틴을 추출하고 추출수율을 극대화할 수 있는 추출조건을 탐색하고자 실시하였다. 추출방법은 일반추출방법, 열수추출방법 및 효소가수분해 추출방법을 이용하였으며 각 추출방법에 따른 수율 및 추출물내의 황산 콘드로이틴의 양을 측정하였다. 추출방법간의 비교에서 일반추출법(대조구) 보다 열수추출과 효소가수분해 추출의 수율이 더 높게 나타났으며 유의적인 차이를 보였다(P<0.05). 효소가수분해 추출에서 식육부산물 중 가장 높은 값을 나타낸 것은 닭 기관, 소 기관, 소 간 순이었다(P<0.05). 모든 추출방법 간에 있어서 소기관의 황산콘드로이틴 함량이 가장 높았으며 효소가수분해 추출방법에 의한 소기관의 황산콘드로이틴 함량이(21.19±1.82) 가장 높은 수치를 나타내었다(P<0.05). 추출물의 수율에 영향을 미치는 에탄올에 의한 추출물 분별침전에서는 에탄올 농도가 증가할수록 황산콘드로이틴 수율이 증가하였다. 결론적으로 식육부산물로부터 황산콘드로이틴을 추출하는데 있어 효소가수분해방법이 가장 좋은 결과를 나타내었다.

• The Korean Journal of Physiology and Pharmacology
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• 제11권1호
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• pp.1-7
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• 2007

Altered environmental gravity, including both hypo- and hypergravity, may result in space adaptation syndrome. To explore the characteristics of this adaptive plasticity, the expression of immediate early gene c-fos mRNA in the vestibular related tissues following an exposure to hypergravity stimulus was determined in rats. The animals were subjected to a force of 2 g (twice earth's gravity) for 1, 3, or 12 h, and were examined poststimulus at 0, 2, 6, 12, and 24 h. RT-PCR (reverse transcription polymerase chain reaction) and real-time quantitative RT-PCR were adopted to analyze temporal changes in the expression of c-fos mRNA. The hypergravity stimulus increased the expression of c-fos mRNA in the vestibular ganglion, medial vestibular nucleus, inferior vestibular nucleus, hippocampus, cerebellum, and cortex. The peak expression occurred at 0 h poststimulation in animals stimulated with hypergravity for 1 h, and at 6 h poststimulus in those stimulated for 3 h. In contrast, those stimulated for 12 h exhibited dual peaks at 0 and 12 h poststimulus. Bilateral labyrinthectomy markedly attenuated the degree of c-fos mRNA expression. Glutamate receptor antagonist also dramatically attenuated the degree of c-fos mRNA expression. These results indicate that expression of c-fos mRNA in response to hypergravity occurs in the vestibular related tissues of the central nervous system, in which peripheral vestibular receptors and glutamate receptors play an important role. The temporal pattern of c-fos mRNA expression depended on the duration of the hypergravity stimulus.

• Asian-Australasian Journal of Animal Sciences
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• 제32권1호
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• pp.126-136
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• 2019

Objective: This study was performed to compare fat content, reducing sugar contents, sensory traits, and fatty acid (FA) and volatile compound profiles in longissimus thoracis (LT) among Korean cattle (KC), Holstein (HO), and Angus (AN) steers. Methods: Twelve LT samples (about 500 g each) of KC with an average age of $31{\pm}0.42months$, an average carcass weight of $431{\pm}12.5kg$, and a quality grade (QG) of 1+ were obtained from the joint livestock products market. Twelve LT samples of HO cattle with an average age of $24{\pm}0.54months$, an average carcass weight of $402{\pm}7.81kg$, and a QG of 2 were also obtained from the same market. Twelve LT samples of AN steers with an average age of about 20 months and a QG of choice were purchased from a beef delivery company. After slaughter, samples were kept at $4^{\circ}C$ for 42 days and prepared for immediate analysis or stored at appropriate conditions. The chemical composition, color, pH, shear force, collagen content, reducing sugars, sensory evaluation, FA composition, and volatile compound content for each LT sample were analyzed. Results: The LT of KC had the highest (p<0.05) fat content, the highest reducing sugar content, and the highest scores in the sensory evaluation (flavor, tenderness, juiciness, and overall acceptance). All the sensory traits were positively correlated (p<0.001) with intramuscular fat and reducing sugar content. Several FAs and volatile compound profiles varied among the breeds. KC LT had the highest (p<0.05) concentrations of acetaldehyde, 3-methyl butanal, and 3-hydroxy-2-butanone, and these volatile compounds were positively correlated (p<0.05) with all the sensory traits. Conclusion: Variations in fat content and reducing sugar contents and FA and volatile compound profiles may contribute to differences in the sensory quality of LT among breeds.

• 수산해양기술연구
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• 제57권3호
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• pp.236-245
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• 2021

In this study, a drifting test using a experimental vessel (2,966 tons) in the northern waters of Jeju was carried out for the first time in order to obtain the fundamental data for drift. During the test, it was shown that the average leeway speed and direction by GPS position were 0.362 m/s and 155.54° respectively and the leeway rate for wind speed was 8.80%. The analysis of linear regression modes about leeway speed and direction of the experimental vessel indicated that wind or current (i.e. explanatory variable) had a greater influence upon response variable (e.g. leeway speed or direction) with the speed of the wind and current rather than their directions. On the other hand, the result of multiple regression model analysis was able to predict that the direction was negative, and it was demonstrated that predicted values of leeway speed and direction using an experimental vessel is to be more influential by current than wind while the leeway speed through variance and covariance was positive. In terms of the leeway direction of the experimental vessel, the same result of the leeway speed appeared except for a possibility of the existence of multi-collinearity. Then, it can be interpreted that the explanatory variables were less descriptive in the predicted values of the leeway direction. As a result, the prediction of leeway speed and direction can be demonstrated as following equations. Ŷ₁= 0.4031-0.0032X₁+0.0631X₂-0.0010X₃+0.4110X₄ Ŷ₂= 0.4031-0.6662X₁+27.1955X₂-0.6787X₃-420.4833X₄ However, many drift tests using actual vessels and various drifting objects will provide reasonable estimations, so that they can help search and rescue fishing gears as well.

• Journal of Animal Science and Technology
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• 제63권3호
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• pp.545-562
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• 2021

A 3 yr experiment was conducted to evaluate the influence of diet and feeding location on animal performance, carcass characteristics, whole blood counts, and internal parasite burden of lambs assigned to 1 of 4 treatments: 1) confinement fed 71% alfalfa, 18% barley pellet, 5% molasses, 0.013% Bovatec, 6.1% vitamin/mineral package diet (CALF), 2) confinement fed 60% barley, 26% alfalfa pellet, 4% molasses, 2.5% soybean-hi pro, 0.016% Bovatec, 7.4% vitamin/mineral package diet (CBAR), 3) field fed 71% alfalfa, 18% barley pellet, 5% molasses, 0.013% Bovatec, 6.1% vitamin/mineral package diet (FALF), and 4) field fed 60% barley, 26% alfalfa pellet, 4% molasses, 2.5% soybean-hi pro, 0.016% Bovatec, 7.4% vitamin/mineral package diet (FBAR). A year × location interaction was detected for ending body weight (BW), average daily gain (ADG), and dry matter intake (DMI); therefore results are presented by year. In all years, cost of gain and DMI were greater for CALF and FALF than for CBAR and FBAR feed treatments (p ≤ 0.03). In yr 2 and 3 field treatments had greater ending BW and ADG than confinement treatments. For all years, diet did not affect ending BW or ADG. In yr 1 dressing percent and rib eye area were greater for field finished lambs than confinement finished (p ≤ 0.02) and Warner-Bratzler shear force was greater for CALF and FALF (p = 0.03). In yr 2 lambs in FALF and FBAR treatments had greater leg scores and conformation than CALF and CBAR (p = 0.09). In yr 1, FALF had a greater small intestine total worm count than all other treatments. In yr 1, ending Trichostrongyle type egg counts were greater for FALF (p = 0.05). In yr 2, ending Nematodirus spp. egg counts were greater for FALF and lowest for CBAR (p < 0.01). Abomasum Teladorsagia circumcinta worm burden was greater in CALF than all other treatments (p = 0.07) in yr 2. While field finishing lambs with a grain- or forage-based diet we conclude that it is possible to produce a quality lamb product without adverse effects to animal performance, carcass quality or increasing parasite burdens.

• 한국항해항만학회지
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• 제44권6호
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• pp.439-446
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• 2020

세계적인 환경오염 규제 및 IMO(국제해사기구)의 선박 연료 황 함유량 제한으로 LNG를 선박의 연료로 사용하는 연구 및 사업이 활발히 진행되고 있다. 본 연구에서는 기존 연구를 통해 개발된 부유식 LNG 벙커링 터미널(FLBT, Floating LNG bunkering terminal)을 대상으로, STS LNG 벙커링 작업을 위해 이접안 하는 과정을 벙커링 셔틀선의 환경하중을 모형시험과 수치해석으로 평가하였다. 고차경계요소법을 이용한 수치해석으로 가까운 위치에서 상호작용 하는 4척 선박들의 파랑표류력 변화를 검토하였다. 다양한 이접안 거리에 따라 파랑표류력이 크게 변함을 확인 했다. 모형시험은 선박해양플랜트연구소의 해양공학수조에서 이루어졌다. 모형시험에서는 예인선을 모사하여 대상선박을 밀고 당길 수 있는 치구를 고안하였으며 접안시 마찰력 등의 영향 없이 선박을 밀 수 있도록 하였다. 모형시험 결과 LNG벙커링 선박은 대부분의 1년 환경조건에서 안전한 이접안이 가능하였다. 파랑 방향에 따라 안정성의 차이가 존재함으로, FLBT의 Heading conrol 기능을 적용하여 횡파를 피한다면 더욱 안정적인 운용이 가능할 것이다.

• 한국초지조사료학회지
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• 제42권2호
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• pp.96-102
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• 2022

본 연구에서는 미생물 첨가제와 사일로 밀도가 총체벼 곤포 사일리지의 영양소 함량, 발효특성 및 호기적 안전성에 미치는 영향을 규명하고자 수행하였다. 미생물 첨가와 사일로 밀도는 사일리지의 영양소 함량에 영향을 미치지 않았다. 하지만, INO 시험구에서 lactate 함량, lactate와 acetate 비율 및 LAB는 감소하였고, propionate 함량, yeast 및 호기적 안전성은 증가하였다. 사일로 밀도는 pH와 lactate 함량에 영향을 미쳤으나, 처리 구간 차이는 매우 적었다. 이상의 결과에서, L. brevis 5M2와 L. buchneri 6M1을 포함한 혼합형 LAB 첨가제 사용은 총체벼 곤포 사일리지의 호기적 안전성 개선에 유리하며, 사일로 밀도는 베일 압력이 430~770 kgf/cm²일 때 정상적인 사일리지 발효가 일어나는 것으로 확인되었다.