• 반도체디스플레이기술학회지
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• 제21권1호
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• pp.103-107
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• 2022

Scaffolds are the structures that safely protect sensors in various parts of the body. Because of scaffolds must protect sensors from load, the tensile strength of the scaffolds must be higher than 750 kgf/cm². Currently, the tensile strength of scaffolds made with the 3d printer is 714 kgf/cm². We confirm that the tensile strength of the scaffolds increase using air with high nitrogen concentration. In this study, we conducted experiments to find nitrogen concentrations in which the tensile strength of the specimen is higher than 750 kgf/cm². The nitrogen control device and the nitrogen concentration sensor were installed in the chamber type 3d printer. The nitrogen concentration inside the 3d printer was changed by 5 % from 80 % to 100 %. Specimens of ASTM D 638 standard were produced under changed nitrogen concentration. We measured the tensile strength of specimens. We compared the tensile strength of specimens produced under each nitrogen concentration. We confirmed that when air with nitrogen concentration of 90 % was used, the tensile strength of scaffolds were 762 kgf/cm².

• Journal of Biosystems Engineering
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• 제15권4호
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• pp.328-338
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• 1990

The objective of this study was to develop automatic systems of nutrient solution management for optimal nutrient solution environment and labor saving in water culture which enables factory crop production. In this study, an automatic control system and its driving program are developed to prepare, supply, and recover nutrient solution and to keep the optimal solution concentration level using microcomputers. Based on this study, the following conclusions are obtained: 1. The concentration measured by the system using oscillating circuit designed and built in this study, gave good agreements with the actual nutrient solution. 2. In water culture, the period of 12 hours for measuring concentration, pH, and temperature of the nutrient solution was optimum. Addition of control solution due to the decrease of the nutrient solution concentration is required in every 3 to 5 days. 3. It is estimated that the period of the whole solution change is 15 days, however, further research is needed to assure it. In addition, this period must be shortened in the future. 4. Both the hardware and software of the developed optimal nutrient solution control system in the water culture are working very well, however, it is necessary to develop a more economical one-chip micro controller to substitute for the microcomputer.

• 한국염색가공학회지
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• 제9권2호
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• pp.41-49
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• 1997

To control free formaldehyde release from fabric finished with N-methylol compounds, resin finished cotton fabric was treated with resorcinol solution, dried and cured. Factors affecting to control formaldehyde release have been investigated. It was shown that the aftertreatment with resorcinol greatly suppressed the free formaldehyde release. Up to concentration of about 5% of resorcinol, the concentration of resorcinol effected on the control of free and evolved formaldehyde. And at high concentration of resorcinol, however, the concentration became rather insensitive to contol formaldehyde release. Addition of some salt catalysts such as ammonium chloride, zinc nitrate, sodium acetate and ammonium acetate, was effective in decreasing formaldehyde release. Considering the effect on the control of formaldehyde and crease recovery, ammonium acetate was concidered to be the best catalyst. It was observed that the optimum curing temperature for the resorcinol treatment was about 15$0^{\circ}C$, and that the curing time did not affected formaldehyde release over three minutes. Although the treatment of resorcinol had a little adverse effect on crease recovery of resin finished fabric, this effect could be negligible.

• 한국환경농학회지
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• 제42권3호
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• pp.231-238
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• 2023

We analyzed the variations in the CO₂ concentration and temperature between a CO₂-enriched and control greenhouse. We cultivated Alstroemeria 'Hanhera' in the two greenhouses and assessed the growth parameters (stem length, stem thickness, and the number of flowers) and yield. The CO₂-enriched greenhouse had a CO₂ generator that produced CO₂ at rate of 0.36 kg/h and its windows were programmed to open when the temperature exceeded 20℃ and close when it dropped below 15℃. The control greenhouse had no additional CO₂ supplementation, and its windows were programmed to open when the temperature exceeded 20℃ and close at approximately 17:00. In the morning, CO₂ concentration remained above 500 ppm in the CO₂-enriched greenhouse, which was higher than that in the control greenhouse (approximately 370 ppm). The ventilation effect only through the side windows to reduce the temperature in both greenhouses did not appear dynamically. CO₂ supplementation promoted plant growth, resulting in a significant increase in plant yield of over 60% compared to that of the control greenhouse. Our findings suggest that elevated CO₂ concentration in the morning can significantly promote the growth and development of Alstroemeria during the winter.

• Journal of Preventive Medicine and Public Health
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• 제21권2호
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• pp.351-356
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• 1988

To evaluate the possible functional role of serum nickel during the process of parturition, 15 serum samples were collected and analysed for the nickel concentrations in each 3 groups(Group 1 for the period during parturition, Group 2 for the period from delivery of fetus to delivery of placenta, and Group 3 for the period after delivery of placenta) of normal, uncomplicated full term vaginal delivery and one control group composed of healthy unmarried women in 3rd decades of age. Data revealed that average serum nickel concentration of Group 2($26.6{\mu}g/l$) and Group 1($22.2{\mu}g/l$) were significantly higher than that of Control group($13.7{\mu}g/l$), but Group 3's($13.8{\mu}g/l$) was almost same as Control group's. There were significant negative correlation between age and serum nickel concentration in group 2, and a tendency of higher nickel concentration in women who have no previous experiences of pregnancy than who have previous experiences of pregnancy, although it was not significant. These result could be indicative of close causal relationship between serum nickel concentration and the entire process of parturition.

• 대한수의학회지
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• 제56권4호
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• pp.205-208
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• 2016

The aim of the present study is to investigate the potential influence of obesity as a factor in 5-hydroxytryptamine (5-HT) concentration in myxomatous mitral valve disease (MMVD) dogs. Fifty-five client-owned dogs were enrolled in a randomized trial. Dogs were classified by echocardiography into healthy (control), mild, and moderate to severe MMVD groups. Each group was subclassified by using a 9-point body condition score (BCS); lean (BCS 5-6/9) and obese groups (BCS 7.5-9/9). Dogs with moderate to severe MMVD had lower serotonin (5-HT) concentrations than the control group (p = 0.03). Dogs with moderate to severe MMVD (p = 0.017) had lower serum 5-HT concentrations than the control group in the obese group (BCS 7.5-9/9). Significant difference was found between the lean and obese groups (p = 0.015) which are not consider severe in the MMVD group. These results suggested that 5-HT concentration was decreased with the increasing severity of MMVD, and obesity might be taken into consideration when interpreting the serotonin concentration in MMVD dogs.

• 인간식물환경학회지
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• 제22권2호
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• pp.199-207
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• 2019

The purpose of this study was to investigate the mood states and concentration of students when they see the natural scenery indoors throughout the Free Semester Program (FSP) of middle school. The subjects were total 180 students comprised of 60 students in the group viewing natural scenery, 60 students in the group viewing urban scenery and 60 students in the control group from the first year of middle school located in Daejeon, and the experiment was carried out from September 3 to October 30, in 2018. The results showed that tension, depression, anger, fatigue and confusion were decreased and vigor was increased significantly in group viewing natural scenery compared to group viewing urban scenery and the control group. Ratings of 'pleasant,' 'natural,' and 'calm' were increased and concentration was also improved significantly in the group viewing natural scenery compared to the group viewing urban scenery and the control group. This indicates that positive effects can be anticipated on the improvement of mood states and concentration by developing indoor program viewing natural scenery for people who have difficulties in outdoor activities.

• 한국의류산업학회지
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• 제6권3호
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• pp.393-398
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• 2004

This research offers recycling method of NaOH from mercerizing process of cotton fabric. The measuring system of NaOH concentration was designed for the mercerizing process and tested for various conditions which can be occurred in factory. The accuracy of the system was varied as the testing condition was changed. As the concentration of sulfuric acid used for titrating NaOH decreased, the accuracy of measuring system increased. The concentration of NaOH for waste water collected from mercerizing process was measured by 5.2%. As the ratio of newly mixed NaOH increased, moisture regain. water absorbency and whiteness of the specimen increased. The bending rigidity(B) and shear rigidity(G) decreased, as the ratio of newly mixed NaOH increased.

• Asian-Australasian Journal of Animal Sciences
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• 제16권1호
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• pp.88-95
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• 2003

The objective of the present study was to determine the effect of exogenous bovine somatotropin on the mammary function in late lactating crossbred Holstein cows. Twelve 87.5% late lactating Holstein cows, approximately 30 weeks postpartum, were divided into two groups of 6 animals each. Animals in the control group were given sodium bicarbonate buffer by subcutaneous injection, while animals in the treated group were given recombinant bovine somatotropin (bST) by subcutaneous injection with 500 mg of bST (14 day prolonged-release bST). After bST injection, milk yield significantly increased from the control level on day 8 to day 20 (p<0.05) with a concomitant increase in mammary blood flow (p<0.01). An increase in mammary blood flow in response to bST treatment was greater than an increase in milk production. An increased plasma concentration of IGF-I coincided with an increase in mammary blood flow in animals treated with bST. There were no significant changes in the concentration of arterial plasma glucose concentration, the arteriovenous concentration difference (A-V difference) and mammary extraction ratio while the mammary glucose uptake increased when compared to the control group. The concentration of arterial plasma triglyceride decreased throughout the experimental period in animals give bST. The plasma concentration of acetate, and the mammary uptake for acetate significantly increased (p<0.05) after bST treatment. The action of bST did not affect the plasma concentration, A-V difference and extraction ratio across the mammary gland for $\beta$-hydroxybutyrate. The concentrations of milk fat and lactose tended to increase during bST treatment. Milk protein concentration initially increased in the first few days and decreased after bST injection when compared to the pretreated period. The present results indicated that bST could affect the mammary function in late lactating cows by increase in milk yield involving changes in both extra-mammary and intra-mammary mechanisms. The exogenous bST exerted its galactopoietic action through an increase in circulating IGF-I of the late lactating Crossbred Holstein cattle.

• 대한예방한의학회지
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• 제13권2호
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• pp.77-87
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• 2009

Purpose : To evaluate the effects of Samultang(SMT) on the metals in the dams and fetuses Method : SMT(Decoction) was administered orally using different concentrations to pregnant Sprague-Dawley rats for 20days after being assigned randomly to 5 groups. Each group has 11 dams. Pregnant rats were sacrificed at the 20th day of gestation and metal concentration in the dams and fetuses was observed using a ICP-MS and mercury analyzer. Results : Hg concentration in the blood of dams was lower in the $SMT{\times}1$, $SMT{\times}2$, $SMT{\times}4$group than VC(Vehicle Control) and Control group. Hg concentration in the organs of dams was lower in the $SMT{\times}1$, $SMT{\times}2$, $SMT{\times}4$ group than VC, Control group. Whereas Cd concentration in the organs of fetuses was getting lower as increasing SMT dose, Hg concentration in the organs of fetuses was getting higher as increasing SMT dose. Discussion and Conclusion : There were not any significant harmful differences of metal concentration in the dams and fetuses treated by SMT. Particularly, SMT showed the possibility of efficacy to reduce the concentration of Hg in dams but to increase the concentration of Hg in fetuses. The mechanism of reduction is not yet proven. A hypothesis says there is a possibility of the chelation effect between the essential elements of herbs and heavy metals. Another hypothesis is the possibility of Hg transmission from dam to fetus. Further study should be conducted to make guidelines for the safe use of herbal medicine.