• 대한약리학회지
• /
• 제13권2호
• /
• pp.67-73
• /
• 1977

The nitrogen sparing effect of intravenous 3% amino acid solution was compared with 5% dextrose solution in 30 patients who were undergoing surgical operations or radiation therapy. Infusion of 3% amino acid solution or 5% dextrose solution was given before and immediately after operations or irradiation and continued for 6 days. Infusion of solutions through peripheral vein was well tolerated and not experienced any specific hematologic or blood chemistry change in all patients subjected throughout the experiment. The patients received 3% amino acid solution showed low blood glucose and insulin level, but significantly high blood urea nitrogen and ketone body. In patients receiving amino acids, as compared with those receiving dextrose, mean cumulative six day nitrogen losses were significantly lower($63.95{\pm}2.12$ Gm and $79.12{\pm}2.43Gm$ respectively). The nitrogen sparing effect of amino acids is probably due to decreased glucose and insulin levels allowing greater endogenous fat mobilization.

• Nutrition Research and Practice
• /
• 제13권4호
• /
• pp.323-332
• /
• 2019

BACKGROUND/OBJECTIVES: The aim of this study was to analyze specific foods influencing absolute nutrient intake and between-person variations of nutrient intake among Korean preschoolers. SUBJECTS/METHODS: This study included 2,766 participants aged 1-5 years in the 2009-2013 Korea National Health and Nutrition Examination Surveys. Dietary data were obtained from a 24-h dietary recall method. Major food sources of absolute nutrient intake were evaluated based on percent contribution of each food. To assess the contribution of specific foods to between-person variations in nutrient intake, stepwise multiple regressions were performed and cumulative $R^2$ was used. RESULTS: White rice and milk were main food sources of energy, protein, carbohydrate, phosphorus, iron, potassium, thiamin, riboflavin, and niacin. The percentage of fat contributed by milk was 21.3% which was the highest, followed by pork, soybean oil, and egg. White rice accounted for 25% and 40% of total variability in total energy and carbohydrate intakes, respectively. About 39% of variation in calcium intake was explained by milk while 40% of variation in phosphorous intake was explained by cheese. The top 10 foods contributing to between-person variations in nutrient intakes were similar with food items that mainly contributed to absolute nutrient intakes. The number of foods explaining 90% of absolute amounts of nutrient intakes varied from 28 for vitamin A to 80 for iron. CONCLUSIONS: This study identified specific foods that contributed to absolute nutrient intakes and between-person variations in nutrient intakes among Korean preschoolers. Our findings can be used to develop dietary assessment tools and establish food-based dietary guidelines for young children.

• Structural Engineering and Mechanics
• /
• 제88권2호
• /
• pp.117-128
• /
• 2023

On February 6, 2023, Türkiye woke up with a strong ground motion felt in a wide geography. As a result of the Kahramanmaraş, Pazarcık and Elbistan earthquakes, which took place 9 hours apart, there was great destruction and loss of life. The 2023 Kahramanmaraş earthquakes occurred on active faults known to pose a high seismic hazard, but their effects were devastating. Seismic code spectra were investigated in Hatay, Adıyaman and Kahramanmaraş where destruction is high. The study mainly focuses on the investigation of ground motion parameters of 6 February Kahramanmaraş earthquakes and the correlation between ground motion parameters. In addition, earthquakes greater than Mw 5.0 that occurred in Türkiye were compared with certain seismic parameters. As in the strong ground motion studies, seismic energy parameters such as Arias intensity, characteristic intensity, cumulative absolute velocity and specific energy density were determined, especially considering the duration content of the earthquake. Based on the study, it was concluded that the structures were overloaded far beyond their normal design levels. This, coupled with significant vertical seismic components, is a contributing factor to the collapse of many buildings in the area. In the evaluation made on Arias intensity, much more energy (approximately ten times) emerged in Kahramanmaraş earthquakes compared to other Türkiye earthquakes. No good correlation was found between moment magnitude and peak ground accelerations, peak ground velocities, Arias intensities and ground motion durations in Türkiye earthquakes. Both high seismic components and long ground motion durations caused intense energy to be transferred to the structures. No strong correlation was found between ground motion durations and other seismic parameters. There is a strong positive correlation between PGA and seismic energy parameter AI. Kahramanmaraş earthquakes revealed that changes should be made in the Turkish seismic code to predict higher spectral acceleration values, especially in earthquake-prone regions in Türkiye.

• 대한기계학회논문집A
• /
• 제29권9호
• /
• pp.1235-1242
• /
• 2005

A district heating(DH) system supplies environmentally-friend heat and is appropriate for reduction of energy consumption and/or air pollutions. The DH transmission pipe, composed of supply and return pipes, has been used to transmit the heat and prevent heat loss during transportation. The two types of pipes are operated at a temperature of $75\~115^{\circ}C\;and\;40\~65^{\circ}C$, respectively, with an operating pressure of less than 1.568MPa. The objectives of this paper are to systematize data processing of transition temperature and investigate its effects on fatigue life of DH pipes. For the sake of this, about 5 millions temperature data were measured during one year at ten locations, and then available fatigue lift estimation schemes were examined and applied to quantify the specific thermal fatigue life of each pipe. As a result, a relational database management system as well as reliable fatigue lift evaluation procedures is established for Korean DH pipes. Also, since the prototypal evaluation results satisfied both cycle-based and stress-based fatigue criteria, those can be used as useful information in the future fer optimal design, operation and energy saving via setting of efficient condition and stabilization of water temperature.

• 한국지반공학회논문집
• /
• 제20권8호
• /
• pp.147-158
• /
• 2004

국내 액상화 상세평가에 관한 시방내용을 살펴보면, 지진을 정현하중으로 고려한 등가전단응력개념에 기초하여 전단응력을 달리한 3회 이상의 액상화 발생 실내진동시험을 수행하고 이를 토대로 액상화 저항응력비 곡선을 도시하여 지진규모별로 적용할 것을 명시하고 있다. 즉, 현행 액상화 상세평가에서는 실내진동시험결과인 응력, 변형률, 과잉간극수압, 유효응력, 응력 경괴의 변화 등의 다양한 결과들을 효과적으로 이용하지 못하고 최대전단응력과 액상화 발생시 진동재하횟수라는 단순한 시험결과만을 이용하여 액상화 평가를 수행한다. 본 연구에서는 현행 액상화 상세평가에서의 단순한 시험결과의 이용을 탈피하여 응력, 변형률, 그리고, 과잉간극수압 시간이력들과 응력-변형률 상관관계 및 유효응력경로 등의 다양한 실내진동시험 결과를 토대로 액상화 발생메카니즘을 포함한 지반의 동적저항상태를 분석하였다. 특히, 과잉간극수압의 영향을 고려한 동적 유효응력경로가 지반의 동적거동을 효과적으로 구분하여 나타낼 수 있는 점을 발견하고 이를 토대로 지반의 동적상태를 점진적 응력감소, 급진적 응력감소, 그리고 액상화 후 극한상태의 3단계로 구분하였다. 또한, 액상화 현상이 실제적으로 점진적 응력감소에서 급진적 응력감소로 전환되는 시점에서 대변형을 동반하여 발생한다는 사실을 발견하고 이를 액상화 상태전환시점으로 정의하였으며 이러한 액상화상태전환시점이 압축제하 또는 인장재제하로 하중방향이 바뀌는 시점에서 발생하는 점을 반영하여 1/4주기별 시험결과분석에 기초하여 저항특성을 나타내었다. 그리고, 본 연구를 통해 제안된 액상화 저항특성에 대한 타당성 검토를 위해 과잉간극수압으로 인해 발생하는 지반재료 내부에서 소산되는 에너지 개념과 기제안된 교란상태개념에 기초한 액상화 저항특성과 비교하였다. 연구결과, 제안된 누적 소성 전단변형률은 액상화 발생의 원인이 되는 과잉간 극수압의 영향을 합리적으로 표현하고 있을 뿐만 아니라 진동하중으로부터 소산되는 재료 내부의 에너지 변화를 신뢰성 높게 표현하고 있는 것으로 나타났다. 특히, 제안된 지반의 한계 저항특성의 경우, 기제안된 교란도 함$.$수에 기초한 수치해석방법보다 정확하게 대변형의 영향을 포함하지 않고 한계상태를 표현하고 있는 것으로 나타났다.

• Journal of Nutrition and Health
• /
• 제16권4호
• /
• pp.296-302
• /
• 1983

국가적(國家的) 차원에서의 국민영양소요양(國民營養所要量)을 확립하는데 중요한 지표(指標)가 되는 한국인(韓國人) 평균1인1일당(平均1人1日當) 영양소요양(營養所要量)설정의 필요성에 의하여, 1980년도(年度) 경제기획원인구(經濟企劃院人口)센서스 자료(資料)와 FAO한국협회(韓國協會)가 1980년(年) 제(第)3 차 (次) 개정(改定)한 한국인영양권장양으로부터 한국인(韓國人) 평균(平均)1인(人)1일당(日當) 영양소요양(營養所要量)을 계산(計算)하였다. 즉 영양소별(營養素別) 평균(平均)1인(人)1일당(日當) 영양소요양(營養所要量)은 에너지 2,200 kcal, 단백질(蛋白質) 70 g, 칼슘 0.72 g, 철(鐵) 14 mg, 비타민 A 1,900 IU, 비타민 C 50 mg, 비타민$B_{1}$ 0.9 mg, 비타민 $B_{2}$ 1.2 mg 그리고 나이아신당양(當量)은 15 mg이었다.

• Journal of Radiation Protection and Research
• /
• 제38권4호
• /
• pp.166-171
• /
• 2013

While high-dose ionizing radiation results in long term cellular cytotoxicity, chronic low-dose (<0.2 Gy) of X- or ${\gamma}$-ray irradiation can be beneficial to living organisms by inducing radiation hormesis, stimulating immune function, and adaptive responses. During chronic low-dose-rate radiation (LDR) exposure, whole body of mice is exposed to radiation, however, it remains unclear if LDR causes changes in gene expression of the whole brain. Therefore, we aim to investigate expressed genes (EGs) and signaling pathways specifically regulated by LDR-irradiation ($^{137}Cs$, a cumulative dose of 1.7 Gy for total 100 days) in the whole brain. Using microarray analysis of whole brain RNA extracts harvested from ICR and AKR/J mice after LDR-irradiation, we discovered that two mice strains displayed distinct gene regulation patterns upon LDR-irradiation. In ICR mice, genes involved in ion transport, transition metal ion transport, and developmental cell growth were turned on while, in AKR/J mice, genes involved in sensory perception, cognition, olfactory transduction, G-protein coupled receptor pathways, inflammatory response, proteolysis, and base excision repair were found to be affected by LDR. We validated LDR-sensitive EGs by qPCR and confirmed specific upregulation of S100a7a, Olfr624, and Gm4868 genes in AKR/J mice whole brain. Therefore, our data provide the first report of genetic changes regulated by LDR in the mouse whole brain, which may affect several aspects of brain function.

• 비파괴검사학회지
• /
• 제20권5호
• /
• pp.412-423
• /
• 2000

응력확대계수와 음향방출 발생 관계를 이용해 균열 길이 및 균열 검출 능력을 평가할 수 있는 새로운 접근 방법을 파괴역학적인 관점에서 제시하였다. 이를 위해 강 교량 부재인 SWS 490B 강의 피로 균열 활동도를 음향방출 시험을 통해 관찰하였다. 표준 CT 시편에 대한 피로균열 진전 시 AE 특성을 관찰하는 실험을 진행하였으며, 기존의 AE 파라미터 분석은 물론 응력확대계수와 AE 발생거동 사이의 관계를 논의하였다. CT 시편 실험 결과에서 균열 성장 길이, AE 최대진폭, AE 에너지, AE hit 발생율 등과 같은 특정 변수들은 응력확대계수 값이 증가함에 따라 이들 값도 증가하는 경향을 나타내었다. 또한 피로사이클 수에 따른 AE 에너지의 변화는 균열진전에 대한 활동성을 평가하는데 사용되는 효과적인 변수중의 하나임을 보여 주었으며, AE 에너지 분석은 균열 활동도와 AE 변수 사이의 관계를 평가하는데 사용될 수 있을 것으로 판단된다.

• 한국정밀공학회지
• /
• 제3권1호
• /
• pp.40-49
• /
• 1986

Crack, craze and void are common defects which may be found in the bulk of polymeric materials such as either themoplastics or thermosets. The healing phenomena, autohesion, of these defects are known to be a intrinsic material property of various polymeric materials. However, only a few experimental and theoretical investigations on crack, void and craze healing phenomena for various polymeric materials have been reported up to date [1, 2, 3]. This may be partly due to the complications of healing processes and lacking of appropriate theoretical developments. Recently, some investigators have been urged to study the healing phenomena of various polymenic materials since the significance of the use of polymer based alloys or composites has been raised in terms of specific strength and energy saving. In the earlier published reports [1, 2, 3, 4], the crack and void healing velocity, healing toughness and some other healing mechanical and physical properties were measured experimentally and compared with predicted values by utilizing a simple model such as the reptation model under some resonable assumptions. It seems, however, that the general acceptance of the proposed modeling analyses is yet open question. The crack healing processes seem to be complicate and highly dependent on the state of virgin material in terms of mechanical and physical properties. Furthermore, it is also strongly dependent on the histories of crack, craze and void development including fracture suface morphology, the shape of void and the degree of disentanglement of fibril in the craze. The rate of crack healing may be a function of environmental factors such as healing temperature, time and pressure which gives different contact configurations between two separated surfaces. It seems to be reasonable to assume that the crack healing processes may be divided in several distinguished steps like stress relaxation with molecular chain arrangement, surface contact (wetting), inter- diffusion process and com;oete healing (to obtain the original strength). In this context, it is likely that we no longer have to accept the limitation of cumulative damage theories and fatigue life if it is probable to remove the defects such as crack, craze and void and to restore the original strength of polymers or polymer based compowites by suitable choice of healing histories and methods. In this paper, we wish to present a very simple and intuitive theoretical model for the prediction of healed fracture toughness of cracked or defective polymeric components. The central idea of this investigation, thus, may be the modeling of behavior of chain molecules under healing conditions including the effects of chain scission on the healing processes. The validity of this proposed model will be studied by making comparisons between theoretically predicted values and experimentally determined results in near future and will be reported elsewhere.

• 한국양식학회지
• /
• 제19권4호
• /
• pp.247-253
• /
• 2006

본 실험은 치어기 넙치에 잇어서 ${\beta}-1,3$ 글루칸을 사료내 첨가시 성장, 비특이적 면역반응 및 질병저항성에 미치는 영향을 조사하기 위하여 사료내 ${\beta}-1,3$ 글루칸을 수준별 첨가하여 실시였다. 실험어는 평균무게 3.2 g인 넙치 치어를 사용하였으며, 기초사료에 ${\beta}-1,3$ 글루칸을 대조구, ${\beta}-1,3$ 글루칸 0.01, 0.025%, 0.05% 및 0.1%를 각각 첨가하여 총 5개 실험구로 3반복배치하여 6주간 실시하였다. 총 6주간의 성장 실험결과, 면역증강물질인 ${\beta}-1,3$ 글루칸의 첨가에 따르는 사료효율과 단백질전환효율에 있어서 ${\beta}-1,3$ 글루칸 0.1%를 공급한 사료구가 대조구와 다른처리구에 비하여 유의하게 높은 값을 나타냈다(P<0.05). 증체율과 일간성장율에 있어서는 ${\beta}-1,3$ 글루칸 0.1%를 공급한 사료구가 대조구, ${\beta}-1,3$ 글루칸 0.01%, 0.025%를 첨가한 구보다 유의하게 높은 값을 나타내었지만 ${\beta}-1,3$ 글루칸 0.05%구와는 유의한 차이가 없었다. 비만도에 있어서는 ${\beta}-1,3$ 글루칸 0.05%와 0.1%를 첨가한 구가 대조구와 첨가구보다는 유의적으로 높았다. 헤마토크리트치는 ${\beta}-1,3$ 글루칸 0.05%와 0.1%첨가한 실험구가 대조구와 ${\beta}-1,3$ 글루칸을 0.01%와 0.025%를 첨가한 실험구에 비하여 유의하게 높은 값을 나타내었다(P<0.05). 혈청내 GOT에 있어서 ${\beta}-1,3$ 글루칸 0.05%와 0.1%를 첨가한 실험구가 대조구, ${\beta}-1,3$ 글루칸 0.01%와 0.025%를 첨가한 실험구보다 유의하게 낮은 값을 나타내었다(P<0.05). 비특이적 면역반응 결과에 있어서는 ${\beta}-1,3$ 글루칸을 0.05%와 0.1%를 첨가한 실험구가 혈청의 lysozyme 활성 및 두신 phagocyte의 chemiluminescent(CL) 반응에서 대조구, ${\beta}-1,3$ 글루칸 0.01%와 0.025%를 첨가한 실험구보다 유의하게 높은 값을 나타내었으나, 보체대체활성의 경로에 있어서는 전실험구간의 유의한 차이를 보이지 않았다. 공격 실험 결과에서는 ${\beta}-1,3$ 글루칸을 첨가한 실험구가 대조구에 비하여 초기폐사율이 낮음을 확인할수 있었으며, 상기 결과를 토대로, 넙치 치어의 경우 ${\beta}-1,3$ 글루칸을 0.05% 이상 0.1% 미만을 사료에 첨가하는 것이 성장, 사료효율 증진, 항산화능 및 질병저항성에 가장 좋은 효과를 나타낼 수 있을 것을 사료된다.