• Earthquakes and Structures
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• 제10권3호
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• pp.717-733
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• 2016

Trapezoidal Cemented Sand and Gravel Dam, namely Trapezoid CSG, is a new type of dam. Due to lack of dynamic studies in the field of CSG dam, this research was performed to analyze Trapezoidal CSG dam using dynamic Finite element method with ABAQUS Software. To investigate possible earthquake-induced damages, fragility curves are plotted based on damage index, the length of the cracks created at the dam base and the area of cracked elements in the dam. The seismic analysis indicated that minimum and maximum tensions are generated in the heel and toe of the dam, respectively. According to the fragility curves, with increase in PGA, the possibility of the exceeding the defined limit state is increased. However, the rate of increment is significantly reduced after PGA=0.4 g. Also, the same result is achieved for the second limit state. The "area of cracked elements" is more conservative criterion than the "crack length at the dam base", especially at PGA<0.4 g. As conclusion, CSG dams, despite of being made of poor materials in comparison with concrete dams, show good resistance, and even in some situations, better performance than the weighted concrete dams.

• Structural Engineering and Mechanics
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• 제69권5호
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• pp.557-566
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• 2019

The reservoir basin bedrock produced significant impact on the long-term service safety of super-high arch dams. It was important for accurately identifying geomechanical parameters and its evolution process of reservoir basin bedrock. The deformation modulus mechanism research methods of reservoir basin bedrock deformation modulus for super-high arch dams was carried out by finite element numerical calculation of the reservoir basin bedrock deformation and in-situ monitoring data analysis. The deformation modulus inversion principle of reservoir basin bedrock in a wide range was studied. The convergence criteria for determining the calculation range of reservoir basin of super-high arch dams was put forward. The implementation method was proposed for different layers and zones of reservoir basin bedrock. A practical engineering of a super-high arch dam was taken as the example.

• The Korean Journal of Physiology and Pharmacology
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• 제25권1호
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• pp.39-49
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• 2021

High fructose diet is associated with the global metabolic syndrome (MtS) pandemic. MtS develops in early life, depending on prenatal and postnatal nutritional status. We hypothesized that ovariectomy increases the chances of developing MtS in adult offspring following high fructose intake by the mother. Pregnant C57BL/6J mouse dams drank water with or without 20% fructose during pregnancy and lactation. After weaning, the pups were fed regular chow. The offspring were evaluated until they were 7 months of age after the mice in each group, both sexes, were gonadectomized at 4 weeks of age. The offspring (both sexes) of the dams who had high fructose intake developed MtS. In the offspring of dams who drank tap water, orchiectomy increased the body weight gain and body fat accumulation, while ovariectomy increased the body fat accumulation as compared to the sham controls. In the offspring of dams with high fructose intake, orchiectomy decreased the body weight gain, body fat accumulation, visceral adiposity, and glucose intolerance, while ovariectomy exacerbated all of them as compared to the sham operations. These data indicate that ovariectomy encourages the development of MtS in adult offspring after maternal high fructose intake, while orchiectomy prevents the development of MtS. The sex difference indicates that male and female sex hormones play contradictory roles in the development of MtS.

• Geomechanics and Engineering
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• 제24권5호
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• pp.443-456
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• 2021

Structural design of the vertical displacements and shear strains in the earth fill (EF) dams has great importance in the structural engineering problems. Moreover, far fault earthquakes have significant seismic effects on seismic damage performance of EF dams like the near fault earthquakes. For this reason, three dimensional (3D) earthquake damage performance of Oroville dam is assessed considering different far-fault ground motions in this study. Oroville Dam was built in United States of America-California and its height is 234.7 m (770 ft.). 3D model of Oroville dam is modelled using FLAC3D software based on finite difference approach. In order to represent interaction condition between discrete surfaces, special interface elements are used between dam body and foundation. Non-reflecting seismic boundary conditions (free field and quiet) are defined to the main surfaces of the dam for the nonlinear seismic analyses. 6 different far-fault ground motions are taken into account for the full reservoir condition of Oroville dam. According to nonlinear seismic analysis results, the effects of far-fault ground motions on the nonlinear seismic settlement and shear strain behaviour of Oroville EF dam are determined and evaluated in detail. It is clearly seen that far-fault earthquakes have very significant seismic effects on the settlement-shear strain behaviour of EF dams and these earthquakes create vital important seismic damages on the swelling behaviour of dam body surface. Moreover, it is proposed that far-fault ground motions should not be ignored while modelling EF dams.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.33-33
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• 2023

In this article, the challenges of Iran and the world are compared to the management of available water resources. Especially in recent years, according to the climatic changes that have occurred all over the world and the changes in the rainfall patterns, and the corresponding changes in the management of water resources, the situation in Iran is being investigated. According to the available information, the amount of water on the planet is estimated to be about 1.36 billion cubic kilometers, which covers about 71% of the earth's surface. However, about 97.5% of the water in the world is salty ocean water and only 2.5% is fresh. Therefore, only 0.025% of the total water on the planet will be usable. According to United Nations statistics, 61% of the world's water consumption is in agriculture, 23% in industry, and 8% for drinking, household, and health purposes. Considering the large number of dams in Iran, only 6% of all dams are used to produce electric energy, which is a significant difference compared to the world (approximately 19%).

• Asian-Australasian Journal of Animal Sciences
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• 제20권11호
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• pp.1625-1630
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• 2007

A simulation study was conducted to evaluate the effect of reciprocal cross on the detection and characterization of Mendelian QTL in $F_2$ QTL swine populations. Data were simulated under two different mating designs. In the one-way cross design, six $F_0$ grand sires of one breed and 30 $F_0$ grand dams of another breed generated 10 $F_1$ offspring per dam. Sixteen $F_1$ sires and 64 $F_1$ dams were randomly chosen to produce a total of 640 $F_2$ offspring. In the reciprocal design, three $F_0$ grand sires of A breed and 15 $F_0$ grand dams of B breed were mated to generate 10 $F_1$ offspring per dam. Eight $F_1$ sires and 32 $F_1$ dams were randomly chosen to produce 10 $F_2$ offspring per $F_1$ dam, for a total of 320 $F_2$ offspring. Another mating set comprised three $F_0$ grand sires of B breed and 15 $F_0$ grand dams of A breed to produce the same number of $F_1$ and $F_2$ offspring. A chromosome of 100 cM was simulated with large, medium or small QTL with fixed, similar, or different allele frequencies in parental breeds. Tests between Mendelian models allowed QTL to be characterized as fixed (LC QTL), or segregating at similar (HS QTL) or different (CB QTL) frequencies in parental breeds. When alternate breed alleles segregated in parental breeds, a greater proportion of QTL were classified as CB QTL and estimates of QTL effects for the CB QTL were more unbiased and precise in the reciprocal cross than in the one-way cross. This result suggests that reciprocal cross design allows better characterization of Mendelian QTL in terms of allele frequencies in parental breeds.

• Toxicological Research
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• 제21권1호
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• pp.23-29
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• 2005

A developmental study of CONP01, a new antiarthritic agent, was conducted in Sprague-Dawley rats. Dosage of CONP01 0, 111, 333, and 1000 mg/kg/day were administered to dams orally from day 6 to day 16 of gestation. Two-third of dams per group were subjected to caesarean section on day day 20 of pregnancy for examination of their fetuses, and the remaining one-third of dams per group were allowed to deliver naturally for postnatal examination of their offspring. There was no change in the dams body weights, food consumptions, specific clinical sings and gross findings. There was significant decrease only in the absolute and relative weights of right ovary in 111 mg/kg treatment group, when compared with the vehicle control, whereas other organ weights were not changed. Moreover, no increase in the frequencies of external, visceral and skeletal malformation of fetuses were observed in the treated groups. These results suggest that the oral NOAEL (no observed adverse effect level) of CONP01 may be over 1,000 mg/kg in dams and fetuses of rats.

• 한국환경복원기술학회지
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• 제11권2호
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• pp.40-54
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• 2008

Small and large dams are installed in the course of a stream for maintaining the water level of the stream or obtaining agricultural water. Currently about 18,000 of them are installed in Korea to supply water. However, the environmental problems of small dams are well known : the interruption of stream eco-corridors, deterioration of water quality in the upper reaches of the small dam, changes in the habitats of riparian organisms, damages to the stream scenery. In a very few of these small dams artificial eco-corridors like fishways are installed, but the number is very minimal.Accordingly, to efficiently restore stream eco-corridors by removing these small dams, it will be necessary to closely examine physical impacts, such as changes in the riverbed and changes in the shape of the stream caused by the removal, chemical impacts, such as changes in water quality, and transport and accumulation of contaminated sediments and biological impacts, such as changes in the habitats of organisms, and develop related technologies in advance, and have these technologies verified through demonstration application in the sites. In this study, we analyzed the physical, chemical and ecological impacts of the removal of the above-mentioned small dams, and conducted a research on the demonstration small dam removal project for a spot investigation. As a result, the small dam removal will restore the eco-corridor, there by improving the habitat of fishes and crustaceans. The number of major underwater organisms inhabiting the Gokreungcheon, such as Korean spotted sleepers, Chinese minnows, Microphysogobio yaluensis, Abbottina rivularis, stone morokos, striped shinners, long-nosed barbels, and Chinese mitten crabs, is expected to increase, and the food chain in the ecosystem will improve so that species diversity will improve as well.

• Asian-Australasian Journal of Animal Sciences
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• 제6권4호
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• pp.497-507
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• 1993

Four truncation selection schemes (SSs) were framed to predict and compare the age structures and genetic responses under the influence of various factor employing the scheme-specific algorithms. Two paths of selection, sires (bulls' sires) and dams (bulls' dams) to breed young bulls were considered. Among variable factors, four levels (0.3, 0.5, 0.7, 0.9) of precision of evaluation, five levels (0.0, 0.05, 0.10, 0.15, 0.20 genetic standard deviation) of genetic differences among age classes and 4 levels of proportions selected (for bulls' sire, 0.05, 0.10, 0.125, 0.25, and for bulls' dams 0.02, 0.04, 0.05, and 0.10) contemplated on both paths of selection. The number of age classes for bulls' dams and bulls' sires were 4 or 8 and 2 or 4, respectively. The stayability across age classes for bulls' dams was assumed to be 0.80 or 0.60. The candidates for selection for bulls' sires were equally distributed (0.5 or 0.25) across the age classes. The SS1 (selection on same proportions as candidates' distribution) revealed longest generation lengths and lowest yearly genetic responses. The average ages were youngest and yearly genetic responses were highest in SS4 (selection at each age-specific truncation point with the same average genetic superiority of selected parents across the ages) and followed by SS3 (selection at each agespecific truncation point with same predicted genetic values) and SS2 (selection at common truncation point on phenotypic values) in a population with overlapping generations. The results revealed the importance of choosing suitable selection scheme to acquire maximum yearly genetic responses especially when the genetic differences among age classes are large and the precision of evaluation is relatively low.

• 대한수의학회지
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• 제43권4호
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• pp.657-666
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• 2003

The present study was undertaken to evaluate the potential adverse effects of 2-BP on pregnant dams and embryo-fetal development after maternal exposure during the gestational days (GD) 6 through 19 in Sprague-Dawley rats. The test chemical was administered subcutaneously to pregnant rats at dose levels of 0, 375, 750 and 1250 mg/kg/day. During the test period, clinical signs, mortality, body weights and food consumption were examined. All dams were subjected to caesarean section on GD 20 and their fetuses were examined for external, visceral and skeletal abnormalities. At above 750 mg/kg, toxic effects including signs of toxicity, suppressed body weight, decreased gravid uterine weight and reduced food intake were observed in pregnant dams. An increase in the fetal deaths, a decrease in the litter size, a reduction in the fetal body weight and an increase in the incidence of fetal morphological alterations were also found. There were no adverse effects on either pregnant dams or embryo-fetal development at a dose level of 375 mg/kg. These results suggest that a 14-day subcutaneous dose of 2-BP is embryolethal and teratogenic at above 750 mg/kg/day in pregnant rats. In the present experimental condition, the no-observed-adverse-effect level of 2-BP is considered to be 375 mg/kg/day for dams and embryo-fetuses, respectively.