• Nutritional Sciences
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• 제9권1호
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• pp.42-47
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• 2006

It has been reported that taking a proper amount of calcium and vitamin D helps to increase bone mineral density (BMD) and is effective in decreasing the risk of osteoporosis. This study investigated the supplementary effects of calcium and vitamin D on postmenopausal women who had osteoporosis and used calcium and vitamin D supplements. The study subjects consisted of osteoporotic postmenopausal women who were recruited from the Department of Orthopedics in a university-affiliated hospital. Sixty-seven study subjects were orally administrated 1,000 mg of calcium (calcium carbonate) and 2.5 mg of active vitamin D (1-$\alpha$ hydroxyvitamin D) (cholecalciferol 250 IU) twice a day for a year and a half. BMD and biochemical markers were evaluated and repeated every six months. One year after the intervention test, the bone mineral density of the lumbar spine was significantly increased as compared to the baseline. Six months after supplement administration, the level of serum alkaline phosphatase began to decrease, and afterwards a significant difference was maintained Concentration of 1, 25-dihydroxy-vitamin D at 1.5 years was higher than that of the baseline. In comparison with that of the baseline, the level of urinary hydroxyproline in the study subjects over six months was significantly decreased This study continued that effects such as BMD improvement and changes in biochemical markers appeared at least one year after administration of supplements.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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• pp.221-224
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• 2002

Recently, simulation of Chemical Mechanical Polis hing is becoming more important because Process parameters on the material removal rate are complicated. And pattern-depent effects are a key concern in CMP processes. In this paper, we have been studied the changes of pattern density vs. oxide thickness with Stine's simulation model. We also have estimated the effective density using optimal window size with density mask, and have made a study of the change of oxide thickness as a function of polishing time.

• Corrosion Science and Technology
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• 제7권4호
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• pp.237-242
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• 2008

Physical properties of water, such as dielectric constant and ionic product, significantly vary with the density of water. In the supercritical conditions, since density of water widely varies with pressure, pressure has a strong influence on physical properties of water. Dielectric constant represents a character of water as a solvent, which determines solubility of an inorganic compound including metal oxides. Dissociation equilibrium of an acid is also strongly dependent on water density. Dissociation constant of acid rises with increased density of water, resulting in drop of pH. Density of water and the density-related physical properties of water, therefore, are the major governing factors of corrosion and environmentally assisted cracking of metals in supercritical aqueous solutions. This paper discusses importance of "physical properties of water" in understanding corrosion and cracking behavior of alloys in supercritical water environments, based on experimental data and estimated solubility of metal oxides. It has been pointed out that the water density can have significant effects on stress corrosion cracking (SCC) susceptibility of metals in supercritical water, when dissolution of metal plays the key role in the cracking phenomena.

• 한국작물학회지
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• 제46권2호
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• pp.95-99
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• 2001

Soybean [Glycine max (L.) Merr.) is known to produce the highest total digestible mutrients (TDN) yield among summer grain legumes in Jeju area but little is known about the effects of cultural practices on forage yield and quality. A determinate soybean cv. Baegunkong was planted on 5 June, 20 June, and 3 July and grown at four plant densities (30, 50, 70 and 90 plants $m^{-2}$ in 1998 in Jeju to evaluate the effects of planting date and plant density on the yield and quality of soybean forage. Days to flowering decreased from 47 to 38 days, average plant height from 61 to 51cm and main stem diameter from 6.31 to 5.00mm as planting was delayed from 5 June to 3 July. Average plant height quadratically increased from 45 to 62cm as plant density increased from 30 to 90 plants $m^{-2}$. Planting date did not affect the average dry matter, crude protein, and TDN yields. The average dry matter and TDN yields displayed a quadratic response to plant density and the optimum plant density for both dry matter and TDN yields was estimated about 60 plants $m^{-2}$. Plant density had no effect on crude protein yield. Planting date did not significantly influence forage quality. The crude protein content was not significantly influenced by plant density. Increasing plant density slightly increased acid detergent fiber content but slightly decreased TDN content.

• 한국초전도ㆍ저온공학회논문지
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• 제21권2호
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• pp.40-44
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• 2019

In this study, the effects of the compaction method for (Mg+2B) powders on the apparent density and superconducting properties of $MgB_2$ bulk superconductor were investigated. The raw powders used in this study were nano-sized boron (B) and spherical magnesium (Mg). A batch of a powder mixture of (Mg+2B) was put in a steel mold and uniaxially pressed at 1 ton or 3 tons into pellets. Another batch of the powder mixture was uniaxially pressed at 1 ton and then pressed isostatically at $1800kg/cm^2$ in the water chamber. All pellets were heat-treated at $650^{\circ}C$ for 1 h in flowing argon gas for the formation of $MgB_2$. The apparent density of powder compacts pressed at 3 ton was higher than that at 1 ton. The cold isostatic pressing (CIP) in a water chamber allowed further increase of the apparent density of powder compacts, which influenced the pellet density of the final products ($MgB_2$). The compaction methods (uniaxial pressing and CIP) did not affect the formation of $MgB_2$ and superconducting critical temperature ($T_c$) of $MgB_2$, but affected the critical current density ($J_c$) of $MgB_2$ significantly. The sample with the high apparent density showed high $J_c$ at 5 K and 20 K at applied magnetic fields (0-5 T).

• 한국의류학회지
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• 제39권4호
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• pp.613-624
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• 2015

This study examined: 1) the effect of store density on perceived crowding 2) the difference of perceived price benefit of sale by store density 3) the effect of perceived price benefit and store density on perceived crowding and 4) the effect of perceived crowding and price benefit on shopping behaviors. Store density and perceived crowding were categorized into social and spatial dimensions. Data were collected with 6 (high, medium, and low social and spatial densities) * 2 (sale and no-sale) between-subjects experimental designs. A total of 395 responses were analyzed. The results revealed that social density affected social crowding, but spatial density had no effect on perceived crowding. Price benefit of sale was not different by store density. The sale itself did not affect perceived crowding. Under the social density situation, perceived price benefit reduced spatial crowding and social crowding showed a positive effect on purchase behavior while spatial crowding had a negative effect. However, the most important effect on purchase behavior was price benefit. The study implies that social density (not spatial density) is important for consumer behavior and retail strategies.

• Journal of Nutrition and Health
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• 제29권9호
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• pp.943-949
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• 1996

Bone mineral density depends largely on the status of dietary minerals such as Ca, P, Mg, and F and proteins, physical activities, parathyroid hormone(PTH), calcitonin(CT), and vitamin D. The decrease of bone density often results in bone fractures and osteoporosis which is prevalent among postmenopausal women. This study was intended to examine the role of parathyroid hormone, calcitonin and cholecaliferol in bone density of mice that were fed different dual photon energy beams. We have measured three major parts of the bone : whole body, head and femur. The results are summarized as follows : 1) Bone mineral density (BMD) was more increased by feeding high Ca diet compared to that of the low Ca diet. 2) Both PTH and Vit D3 enhanced BMD in all of the different Ca levels. 3) When the dietary Ca was deequate CT showed a synergistic effect with PTH in boosting bone density, while CT+Vit D3 showed a negative effect. 4) CT tended to inhibit the effect of increasing bone density by PTH and Vit D3 in medium and low Ca groups. 5) The effect of increasing bone density by PTH in the head of mouse increased when dietary Ca was lower : The increment of bone density by PTH in high, medium, and low Ca was 3%, 8%, 19%, respectively. 6) Femur bone density was affected significantly by dietary Ca levels than hormones. The above observations indicate that bone mineral density can be improved by high dietary Ca and hormone injections including PTH, CT and cholecalciferol, and thus proper dietary and hormonal treatment may be used in preventing bone fractures and osteoporosis.

• 한국농공학회지
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• 제18권3호
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• pp.4163-4170
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• 1976

This study was conducted to investigate the effect of starch as a retarder on the maximum dry density and the unconfined compressive strength of soil cement mixtures for varied starch contents (0-3%), cement contents (3-12%), and delay times (0-6hrs) in four soils. The experimental results obtained from maximum dry density and unconfined compressive strength tests are as follows: 1. Maximum dry density and unconfined compressive strength were increased greatly in soil cement mixtues rwhen starch was added as retarder but their value schanged according to soil varieties. 2. Maximum dry density showed at about 0.5 percent to 1.0 percent of starch in KY soil and about 2.0 percent to 2.5 percent in SS soil when delay time was changed in 2.4, and 6 hours in compaction test. 3. The larger content of cement was, the bigger effects of maximum dry density and compressive strength were in soil cement. mixtures. 4. As delay time changed 2.4, and 6 hours in compaction test, 7-day unconfined compressive strength showed the biggest value at about 0.5 percent of starch in KY soil and 2.0 percent in SS soil, and the maximum value of 28-day unconfined compressive strength showed at about 0.5 percent in KY soil and 1.5 percent in SS soil.

• Journal of Nutrition and Health
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• 제37권4호
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• pp.291-301
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• 2004

We studied the effects of soy isoflavones supplementation with exercise on bone mineral density and the urinary excretion of deoxypyridinoline as an index of bone resorption rates in postmenopausal women. A total of 67 postmen-opausal women were assigned to Isoflavone (90 mg/day) or placebo groups. These group were further divided into groups that undergone a regular exercise or a rather sedentary state performing daily activity only. Four groups were Placebo-control group (n = 16), Placebo-exercise group (n = 16), Isoflavone-sedentary group (n = 19) and Isofla-vone-exercise group (n = 16). After the intervention, we compared anthropometric mesurement, dietary recall, bone mineral density (femoral neck, lumbar spine), urinary deoxypyridinoline between the groups and between the pre and post studies. There were no significant differences between the four groups in terms of average age, height, weight, period after menopause at the baseline. The average age of the subjects were 55.2 yrs, average height, weight, period after menopause were 154.7 cm, 59.3 kg, 5.58 yrs, respectively. After eight week intervention period, there were no significant differences between the four groups in bone mineral density, but urinary deoxypyridinoline excretion was significantly decreased both in Isoflavone-sedentary and Isoflavone-Exercise groups. These results suggest that Isofla-vone supplementation alone or with exercise may be preventive measures through the decrease of bone reabsorption rate in post-menopausal subjects. Whereas exercise alone did not appear to be an effective measure in bone loss with these subjects.

• Asian-Australasian Journal of Animal Sciences
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• 제21권2호
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• pp.262-269
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• 2008

The aim of this study was to determine the effects of breeder age and stocking density on performance, carcass characteristics and some stress parameters (H-L ratio, serum glucose, cholesterol and triglyceride levels, tonic immobility test (TI), antibody production, relative asymmetry (RA) and external appearances). This experiment was carried out with 705 one-day old male broiler chicks (Ross 308) obtained from three different ages of broiler breeder (32, 48 and 61 wks). Each age group was randomly divided into two stocking density groups (11.9 and 17.5 broilers per $m^2$) with 5 replications per group. The experimental period was 6 weeks. Broilers from 32 wk-old breeders had lower initial weight (p<0.001), body weight gain of the first 3 week of rearing (p<0.01), the percentage of abdominal fat (p<0.001) and serum cholesterol level (p<0.01); higher percentage of gizzard (p<0.01) and longer TI duration (p<0.001) than those from 48 and 61 wk-old breeders. Broilers reared at 17.5 b/m2 had lower final BW, body weight gain, feed consumption, feather condition and foot health (p<0.001), higher percentage of heart, H-L ratio, serum glucose and cholesterol levels (p<0.001), and longer TI durations (p<0.001). There were no significant interactions in examined parameters except for feed to gain ratio between breeder age and stocking density.