• 수산해양기술연구
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• 제48권1호
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• pp.20-28
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• 2012

The monofilament with 0.304mm of diameter was produced using a polybutylene succinate (PBS) resin, and a gill net was made by it. We investigated the impact of heat setting temperature on the mechanical properties, knot state and height of gill net. Heat treatment was carried out using the high pressure steam machine for 20 minutes at temperature of $55^{\circ}C$, $60^{\circ}C$, $70^{\circ}C$ and $75^{\circ}C$. Before heat treatment, the strength and elongation of PBS monofilament were estimated to be $48.1kg/mm^2$, 23.8% at unknot, $37.6kg/mm^2$, 18.8% at single knot, $26.6kg/mm^2$, 22.9% at double knot in dry condition, respectively. The strength and elongation of PBS monofilament with double knot were decreased as heat setting temperature increased, and the decreasing rate of strength was showed to be higher than that of elongation. It was not found any differences in strength and elongation of PBS monofilament yarn with double knot at the $65^{\circ}C$ and $70^{\circ}C$ of heat setting temperature by 5% significance of T-test, but there was a significant difference at the $70^{\circ}C$ and $75^{\circ}C$ of heat setting temperature. The net's height and length from leg to leg appeared no differences at the $70^{\circ}C$ and $75^{\circ}C$ of heat setting temperature. In results, it was investigated that the PBS monofilament gill net with the maximized physical properties could be manufactured at $70^{\circ}C$ of heat setting temperature using a high pressure steam machine for 20 minutes.

• 농업과학연구
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• 제49권2호
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• pp.341-355
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• 2022

This research was to examine the differences in post-harvest quality of melons depending on the harvest time after fruit setting. Musk melon cultivar 'K3' plants were grown in glass house conditions with a hydroponic system, and the fruits were harvested at 50, 60, and 70 days after fruit setting. The post-harvest characteristics of melons stored at 7℃ were measured over 32 days. The harvested fruits at 50, 60, 70 days after fruit setting did not differ significantly in weight, height, or size. Solid sugar content was highest in the fruits harvested at 70 days after fruit setting, but firmness, L* value, and respiration rate were highest in the fruits harvested at 50 days after fruit setting. When the harvested melons were stored at 7℃, 'K3' melons responded differently according to the harvest days after fruit setting. The major changes during storage of 'K3' melons can be summarized as follows: Firmness, respiration, moisture content, and general appearance index during storage were highest in the melons harvested at 50 days after fruit setting, but soluble solid content, fresh weight loss, and sensory evaluation were high in the melons harvested at 60 and 70 days after one. During storage at 7℃, there were no significant differences in the appearance of 'K3' melons harvested at different periods after fruit setting, but difference in soluble solid content and taste were noted. It is recommended that the fruit of 'K3' melon plants be harvested about 60 days after fruiting to provide consumers with the highest quality for taste and for storage.

• 설비공학논문집
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• 제12권10호
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• pp.879-885
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• 2000

It is a serious subject for energy conservation to prevent the energy loss caused by mixing of heated and cooled air jets in a building which two types of air-conditioning systems are adopted in perimeter and interior zone. The purpose of this paper is to clarify the quantitative and qualitative mechanisms of the mixing loss and to propose preventive methods for it. In this paper, by using the dynamic heat load calculation method, heat extraction loads of a typical office building in Pusan are calculated. According to the results, numerical simulation based on the computational fluid dynamics were peformed in order to measure the mixing loss in physical size HVAC system. Then, the distributions of air temperature and velocity are analyzed in order to grasp the relations by setting temperature differences influence on the mixing loss.

• 한국건축시공학회지
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• 제12권1호
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• pp.87-97
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• 2012

This paper presents a method of estimating the setting time of cement mortar incorporating recycled aggregate powder (RP) and cement kiln dust (CKD) at various curing temperatures by applying an equivalent age method. To estimate setting time, the equivalent age using apparent activation energy (Ea) was applied. Increasing RP and CKD leads to a shortened initial and final set. Ea at the initial set and final set obtained by Arrhenius function showed differences in response to mixture type. These were estimated to be from 10~19 KJ/mol in all mixtures, which is smaller than those of conventional mixture ranging from 30~50 KJ/mol. Based on the application of Ea to Freisleben Hansen and Pederson's equivalent age function, equivalent age is nearly constant, regardless of curing temperature and RP contents. This implies that the concept of maturity is applicable in estimating the setting time of concrete containing RP and CKD. A high correlation was observed between estimated setting time and measured setting time. A multiregression model was provided to determine setting time reflecting RP and CKD. Thus, the setting time estimation method studied herein can be applicable to concrete incorporating RP and CKD in the construction field.

• Journal of Korean Biological Nursing Science
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• 제18권4호
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• pp.231-238
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• 2016

Purpose: The study aimed to evaluate the changes of body temperature and to identify the factors related to changes during surgery in burned patients. Methods: A retrospective study was conducted by reviewing the medical records of 439 adult burned patients who had a surgery under general anesthesia at the Burn Center of a university hospital. Results: After surgery, body temperature of the burned patients declined from $36.6^{\circ}C$ to $35.2^{\circ}C$; 52.2% were hypothermia. There were significant differences in the changes of body temperature according to the participants' characteristics including American society of anesthesiologists physical status, type of burn injury, total burn surface area, range of exposure, operation time, anesthesia time, amount of fluid, blood transfusion, use of tourniquet, and the method of warming therapy. Factors that influence the temperature changes were total burn surface area (${\beta}=0.26$), operation time (${\beta}=0.25$), amount of fluid (0.20), and warming therapy including 'Room temperature setting + Heated circuit + Hot line'(${\beta}=0.09$) and 'Room temperature setting+one of others'(${\beta}=0.08$). Conclusion: Burned patients experienced a decrease of their body temperature during surgery despite of warming therapy. A nursing protocol is needed to provide an appropriate warming therapy based on their characteristics in burned patients.

• 콘크리트학회논문집
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• 제18권6호
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• pp.759-767
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• 2006

본 연구에서는 등가재령개념에 의한 적산온도방법을 이용하여 플라이애쉬를 사용한 초지연 콘크리트의 응결시간 예측방법을 제시하였다. 플라이애쉬 치환 및 초지연제 혼입률 변화에 따른 양생온도별 응결시간은 초지연제 혼입률이 증가하고, 양생온도가 낮을수록 지연되는 것으로 나타났다. 또한 Arrhenius의 함수에 의한 겉보기 활성화 에너지는 배합별로 약간의 차이는 존재하지만 $24{\sim}35KJ/mol$의 범위로 나타났는데, 이는 일반적인 조건에서의 겉보기 활성화 에너지값의 범위인 $30{\sim}50KJ/mol$ 보다 작은 값으로 나타났다. 플라이애쉬 치환율 및 초지연제 혼입률별 겉보기 활성화 에너지를 등가재령식에 대입한 결과 양생온도별로 거의 유사한 값으로 나타나, 응결시간 예측에 등가재령에 의한 적산온도 방법이 효과적으로 적용될 수 있을 것으로 판단되었다. 아울러 등가재령 및 플라이애쉬 치환율 변화에 따른 초지연제 혼입량 추정에 관한 다중상관 회귀 모델을 제안하여 응결시간 및 초지연제 첨가량을 결정할 수 있도록 하였고 회귀 모델에 의한 해석 예측치와 실측치 간에 매우 양호한 상관성을 갖는 것으로 나타났다. 따라서 본 연구에서 제안된 초지연제 혼입률 및 플라이애쉬 치환율별 응결시간 예측 모델은 실무현장에서 초기재령 콘크리트의 응결 시간 평가에 보다 합리적인 품질관리 방법으로 활용이 가능할 것으로 판단된다.

• 한국작물학회지
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• 제47권5호
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• pp.374-378
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• 2002

To evaluate growth habits, fresh pod yield potential, and possibility of early and late seeding, seeding dates were extended from March 21 to June 20 by PE mulching and non-mulching. Soil temperature, under 5cm from surface, above 15$^{\circ}C$ at 10 a.m. in early seeding reached about March 25 in mulching and April 5 to April 12 in non-mulching. Days to emergence and first flowering were accelerated owing to increasing temperature, as seeding was delayed. Days to emergence according to seeding dates reduced 21 to 8 day in mulching and 33 to 10 day in non-mulching. Days to flowering were ranged from 51 to 26 day in mulching and from 69 to 32 day in non-mulching and differences between mulching and non-mulching on each seeding date had 18 to 4 days. Early seedings till April 21 had 160-170 flowers per plant for 8 weeks, while late seedings from May 21 increased more speedily with 200 flower for 6 weeks. Harvesting of fresh peanut, at 80 days after first flowering, was possible from Aug. 1 to Oct. 7 (133-108 days to harvest) by mulching and from Aug. 19 to Oct. 12 (151 to 114 days) by non-mulching. Yields between mulching and non-mulching in early seeding until April 21 had more difference, but in late seeding after May 21 was higher and showed insignificance. Pod setting periods by early and late seeding were about 3 weeks equally. In late seeding pod setting were almost concentrated for front 15 days. In spite of difference of fresh pod weight between two seeding times, the distributions of average of seed weight showed nearly same tendency.

• 한국염색가공학회지
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• 제12권2호
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• pp.89-95
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• 2000

Effect of twist-setting time, temperature and cylinder layer for the physical properties of the twist yarn were investigated by separated 9 layer from yarn cylinder. Obtained results were as follow. Shrinkage of the yarn in middle layer shows high value with heat-permeation and in inner's shows low value because of cylinder hardness. And then yarn thermal shrinkage in outer layers shows more or less high value because twist yarn in the outer layer sets more faster. Concerning to the difference on the yam physical properties among cylinder layers, the changes on physical properties shows significant differences from the 7th layer to the last one. Linear density, T.P.M and initial modulus decreases but snarl index increases.

• 한국농림기상학회지
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• 제23권4호
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• pp.349-355
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• 2021

본 연구는 꽃눈발아기부터 과실비대기까지 야간온도의 조정이 망고 'Irwin' 품종의 개화, 과실특성 및 수체생육에 미치는 영향을 조사함으로써 망고 재배를 위한 적정 야간온도를 구명하고 시설하우스 내부의 온도관리 방안을 모색하고자 수행하였다. 야간온도 처리에 따른 개화기, 만개기, 착과기, 성숙기 그리고 수확기는 온도가 높을수록 빨라지는 경향을 보였다. 꽃대길이는 야간온도가 10℃일때 가장 짧았으며 온도가 높을수록 생육이 좋아졌으나 15℃와 20℃의 처리간에는 유의차는 없었다. 과실 종경과 무게는 야간온도가 15℃와 20℃가 10℃보다 높게 나타났으며 가용성고형물함량(SSC)와 산함량(TA)은 야간온도 처리간에 차이를 보이지 않았다. 그리고 과실의 경도와 과피의 색도는 야간온도가 높을수록 높게 나타났다. 과실 수확이 끝나고 전정을 한 이후 발생한 가지의 생육은 처리간 유의차를 보이지 않았다. 따라서 망고의 시설하우스 재배 시 과실의 수량을 높이고 고품질 과실을 생산하기 위해서는 야간 최저온도를 15℃ 또는 20℃로 설정하는 것이 적절하며 난방비 절감을 위해서는 야간 최저온도를 15℃로 설정하여 재배하는 것이 바람직한 것으로 판단된다.

• 대한물리의학회지
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• 제17권4호
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• pp.37-43
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• 2022

PURPOSE: To find out how wearing a mask due to COVID-19 affects cardiovascular function as the pace of walking changes. METHODS: Forty-nine college students (27 men, 22 women) were subjected to treadmill exercises without masks (Group I) and wearing masks (Group II). The body temperature, heart rate, oxygen saturation, and blood pressure were measured to determine the changes in cardiovascular function. These parameters were measured at rest (Control I), low-intensity (Control II), medium-intensity (Control III), and high-intensity (Control IV) before and after exercise. RESULTS: Significant differences in heart rate were observed between Control III and Control IV, and a significant difference in oxygen saturation was noted in Control IV. Significant differences in the exercise intensity change in Group II were as follows: Body temperature was Control IV compared to Control I and Control II, heart rate was Control III and Control IV compared to Control I and Control II, and Control IV compared to Control III. The heart rate was Control III and Control IV compared to Control I and Control II, Control IV for Control III, oxygen saturation was Control IV compared to Control I, blood pressure was Control II and Control III and Control IV compared to Control I, and Control IV compared to Control II. CONCLUSION: Exercising when wearing a mask affects the cardiovascular system. Therapists should consider the patient's condition when setting the exercise intensity. In particular, therapists should be more careful when setting the exercise intensity of patients with cardiovascular disease.