• Journal of Radiation Protection and Research
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• 제29권1호
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• pp.41-48
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• 2004

A safety assessment code, called SAGE (Safety Assessment Groundwater Evaluation), has been developed to describe post-closure radionuclide releases and potential radiological doses for low- and intermediate-level radioactive waste (LILW) disposal in an engineered vault facility in Korea. The conceptual model implemented in the code is focused on the release of radionuclide from a gradually degrading engineered barrier system to an underlying unsaturated zone, thence to a saturated groundwater zone. The radionuclide transport equations are solved by spatially discretizing the disposal system into a series of compartments. Mass transfer between compartments is by diffusion/dispersion and advection. In all compartments, radionuclides ate decayed either as a single-member chain or as multi-member chains. The biosphere is represented as a set of steady-state, radionuclide-specific pathway dose conversion factors that are multiplied by the appropriate release rate from the far field for each pathway. The code has the capability to treat input parameters either deterministically or probabilistically. Parameter input is achieved through a user-friendly Graphical User Interface. An application is presented, which is compared against safety assessment results from the other computer codes, to benchmark the reliability of system-level conceptual modeling of the code.

• 상하수도학회지
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• 제25권4호
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• pp.527-534
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• 2011

In this research, the photocatalytic degradation of dibenzothiophene (DBT) in $TiO_2$ aqueous suspension has been studied. $TiO_2$ photocatalysts are prepared by a sol-gel method. The dominant anatase-structure on $TiO_2$ particles is observed after calcining the $TiO_2$ gel at $500^{\circ}C$ for 1hr. Photocatalysts with various transition metals (Nd, Pd and Pt) loading are tested to evaluate the effect of transition metal impurities on photodegradation. The photodegradation efficiencies with $TiO_2$ including Pt and Pd are higher than pure $TiO_2$ powder. Also we investigated the applicability of $H_2O_2$ to increase the efficiency of the $TiO_2$ photocatalytic degradation of dibenzothiophene. The degradation efficiency increases with increasing dosage of $H_2O_2$ in the range of 0.01M to 0.1M . The effect of pH is investigated; we obtained the maximum photodegradation efficiency at pH 5. In addition, the intermediate analysis found dihydroxyl -dibenzothiophene as a reaction intermediate of dibenzothiophene during the photodegradation.

• 소성∙가공
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• 제19권2호
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• pp.101-106
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• 2010

CB100 is one of the channel type products in the steel beam. In this study, rolling process of CB100 is analyzed by 3D FEM simulation and rolling process. FEM simulation result is compared with rolling process data. Also the intermediate & finishing roll stress analysis is carried out and the suitability of the roll through roll stress resultant analysis is evaluated. In order to decrease the roll stress, new pass schedule is developed for stable load balance between intermediate and finishing rolling stand. Therefore new rolling pass schedule is verified by the analysis results of rolling process and roll stress. By the analysis results, the credibility of rolling process analysis was obtained and it was determined that the possibility of roll damage between intermediate and finishing mill was high. So the new pass schedule was developed. Through the result of rolling process and roll stress analysis, it was obtained that the reduction of roll stress and stable load balance.

• 소성∙가공
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• 제24권3호
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• pp.155-160
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• 2015

One of the most important aspects in multi-stage shape drawing is the proper design of the intermediate dies especially to provide adequate metal distribution. In the current study, a method for designing the intermediate dies has been developed to manufacture hollow linear motion guide rails by multi-stage shape drawing. The design method is based on the modified virtual die method. The effectiveness of the proposed design method was verified by FE-simulations and experiments using Mn55Cr carbon steel. From the results of the FE-simulations and the experiments, the proposed design method led to a drawn product with a sound shape. The dimensional tolerances of the product were within the allowable specified tolerances.

• 한국양식학회지
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• 제13권4호
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• pp.339-351
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• 2000

동해안의 주문진 연안에서 1991년 1월부터 1998년 12월까지 한해성 패류인 참가리비, P. yessoensis의 지속적 생산을 위한 중간육성의 서식환경, 성장, 적정 수용밀도, 육성 적수층, 이식시기, 폐사 및 기형패 발생 등에 관한 연구가 수행되었다. 북한한류의 영향을 받는 연구해역에서 참가리비의 주서식층인 10~30m 층의 수온은 4.7~23.8$^{\circ}C$로 고수온을 보인 1994년과 1997년을 제외하고는 참가리비의 생육에 적합한 5~23$^{\circ}C$ 범위였다. 그러나 고수온과 함께 일교차가 크고 불규칙한 변동이 지속되는 시기에 나타나는 성장저하 및 폐사 현상은 수온과 일부 관련이 있는 것으로 보인다. 염분은 31.5~34.5$^{o}\prime_{oo}$로 생육에 비교적 적합하였고, 투명도는 6.0~18.1m로 일반적으로 식물플랑크톤의 출현량에 따라 변화하였다. Chlorophyll-${\alpha}$의 농도는 0.04~3.51${\mu}$g/L로 빈영양 해역의 특성을 보이고 있으며, 해에 따른 변동이 크고, 특히, 여름철에 현저히 감소하는 시기에 참가리비의 폐사가 일부 나타나는 것으로 보아 수온과 함께 참가리비의 성장을 지배하는 하나의 제안인자임을 시사한다. 치패의 중간육성 이식 가능시기는 7월 중순부터 11월 초순사이로 7~8월(1차)에 고밀도로 이식한 후 9월 중순~11월 초순(2차)에 저밀도로 분산하는 것이 성장과 생존율을 향상시킬 수 있는 것으로 여겨진다. 중간육성채롱(square net cage 35${\times}$35cm)에 의한 치패의 적정 수용밀도는 각고 1.5~3cm 내외 크기에서 본 양성용은 30~40개체, 바닥 씨뿌림 양성용은 80~100개체가 적합하였다. 중간육성 기간 중 수층별 성장은 10~15m 층에서 좋았고, 25m 이하 층에서 느렸다. 그러나 수온변동이 크고, 고수온이 지속되는 시기에는 적정밀도로 분산하여 25m 이하 수층에서 관리하는 것이 폐사를 줄일 수 있었다. 중간육성 기간 중 치패의 일간 성장량은 0.019~0.381mm/day로 1~2월에 낮았고, 3~4월에 높았다. 특히, 수용밀도 50개체 이상으로 중간육성 시에는 여름철에 폐사할 위험성이 증가하므로 반드시 6월 이전에 낮은 밀도로 본 양성을 시작하는 것이 좋을 것으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• 제29권3호
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• pp.404-412
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• 2016

We hypothesized that supplementing finishing diets with palm oil would promote adipogenic gene expression and stearoyl-CoA desaturase (SCD) gene expression in subcutaneous (s.c.) and intramuscular (i.m.) adipose tissues of feedlot steers. Eighteen Angus and Angus crossbred steers were assigned to three groups of 6 steers and fed a basal diet (control), with 3% palm oil, or with 3% soybean oil, for 70 d, top-dressed daily. Tailhead s.c. adipose tissue was obtained by biopsy at 14 d before the initiation of dietary treatments and at 35 d of dietary treatments. At slaughter, after 70 d of dietary treatment, tailhead s.c. adipose tissue and i.m. adipose tissue were obtained from the longissimus thoracis muscle. Palm oil increased plasma palmitic acid and soybean oil increased plasma linoleic acid and ${\alpha}$-linolenic acid relative to the initial sampling time. Expression of AMP-activated protein kinase alpha ($AMPK{\alpha}$) and peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) increased between the initial and intermediate biopsies and declined thereafter (p<0.03). SCD gene expression did not change between the initial and intermediate biopsies but declined by over 75% by the final period (p = 0.04), and G-coupled protein receptor 43 (GPR43) gene expression was unaffected by diet or time on trial. Soybean oil decreased (p = 0.01) $PPAR{\gamma}$ gene expression at the intermediate sample time. At the terminal sample time, $PPAR{\gamma}$ and SCD gene expression was less in i.m. adipose tissue than in s.c. adipose tissue (p<0.05). $AMPK{\alpha}$ gene expression was less in s.c. adipose tissue of palm oil-fed steers than in control steers (p = 0.04) and CCAAT enhancer binding protein-beta ($CEBP{\beta}$) gene expression was less in s.c. and i.m. adipose tissues of palm oil-fed steers than in soybean oil-fed steers (p<0.03). Soybean oil decreased SCD gene expression in s.c. adipose tissue (p = 0.05); SCD gene expression in palm oil-fed steers was intermediate between control and soybean oil-fed steers. Contrary to our original hypothesis, palm oil did not promote adipogenic gene expression in s.c. and i.m. adipose tissue.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2000년도 추계학술대회 논문집
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• pp.17-20
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• 2000

In order to improve the sheet formability of the ferritic stainless steel, the through-thickness textures of the recrystallized sample was modified by means of a thermomechanical treatment. An annealing process between the cold rolling reductions modified the preferred orientations throughout the thickness, which resulted in the modification of the final cold rolling texture as well as the final recrystallization texture. With the help of the modification of the recrystallization texture by the intermediate annealing, improvement of the sheet formability, i.e. an increase of the Lankford value.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.215-219
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• 2009

For the effective manufacture of doubly curved metal plates, a line array roll set (LARS) process is proposed. The suggested process utilizes a pair of upper and lower symmetric roll assemblies. In the process, the initial plate is progressed into the final shape in a stepwise or pathwise manner according to the basic principle of the incremental forming process. In this work, the intermediate shape which is closest to a final shape is proposed to fabricate the desired shape effectively in design of forming schedule. The intermediate shape has homogeneous curvature in a longitudinal and transverse direction so that it can be fabricated easily without complicated controls of rolls in the roll set. The method of approximation using genetic algorithm is proposed and applied to some actual ship hulls to evaluate the efficiency of the algorithm.

• Structural Engineering and Mechanics
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• 제55권1호
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• pp.137-160
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• 2015

The one-way (two-way) flexural strength of RCC prisms (circular slabs) reinforced with glass fiber textiles is addressed. To this end, alkaline-resistant glass fiber textiles with three surface weights were used in the composite, the matrix concrete was designed with zero/nonzero slump, and the textiles were used with/without an intermediate layer provided by epoxy resin and sand mortar. Prisms were tested under a four-point loading apparatus and circular slabs were placed on simple supports under a central load. Effects of the amount and geometry of reinforcement, matrix workability, and the intermediate layer on the ultimate load and deflection were investigated. Results revealed that, with a specific reinforcement amount, there is an optimum textile tex for each case, depending on the matrix mix design and the presence of intermediate layer. Similar results were obtained in one-way and two-way bending tests.

• 한국동물생명공학회지
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• 제36권1호
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• pp.51-58
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• 2021

Kisspeptin, a neuropeptide and the master controller of reproductive axis upstream to GnRH neurons, and its receptor are also expressed in extra-hypothalamic tissues, such as ovaries. As systemic kisspeptin has been shown to modulate follicular dynamics in cattle, we hypothesized that kisspeptin has direct actions on the ovarian follicular development. We also hypothesized that kisspeptin regulation of primordial follicle development is via modulation of VEGF expression. In order to test these hypotheses, we cultured caprine ovarian cortical strips in vitro for 7 days with supplementation of kisspeptin at 1, 10 and 100 µM concentration and observed the development of primordial follicles into intermediate, primary and secondary follicles. We also studied the alteration in the expression profile of VEGF and VEGF transcript variant 2 mRNA during follicular development in the presence of kisspeptin. We confirmed the presence of GPR54 in goat ovaries in our preliminary studies. Supplementation of kisspeptin at 1 and 10 µM concentration facilitated the development of primordial follicles into intermediate, primary and secondary follicles with less number of degenerated follicles while the same at 100 µM resulted in degeneration of follicles. We observed a drastic increase in the expression profile of VEGF and VEGF transcript variant 2 mRNA upon culture which was independent of kisspeptin treatment. In conclusion, our studies show that kisspeptin facilitates ovarian primordial development in vitro.