• Journal of the Korea Institute of Building Construction
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• v.17 no.3
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• pp.245-252
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• 2017

Recently, structures such as large retailers, outlets and warehouses have been increasing in accordance with changes in consumption patterns. Since these structures include ultra-flat slab members, they are thoroughly managed to control slab cracking by the plastic and drying shrinkage. In order to control the cracking of the slab member, a chemical crack reduction method is used. In particular, the use of the shrinkage reducing agent has been examined. However, domestic research results are limited. In this study, the shrinkage properties of concrete using shrinkage reducing agent and the drying shrinkage properties according to the mixing factors were investigated. The performance of domestic shrinkage reducing agent was appeared similar to that of overseas high-grade shrinkage reducing agent. As the shrinkage reducing agent usage increased, the drying shrinkage reduction effect increased. At the age of 100 days, the dry shrinkage rate of specimen with the shrinkage reducing agent of 1.5%was shown about half that of the specimen without the shrinkage reducing agent. The shrinkage reducing agent was gound to have no specific performance change for the use of the admixture.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.5
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• pp.247-252
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• 2005

Soil pH is an intensity factor of releasing hydrogen ion which is buffered by aluminum. It depends on pH buffer capacity of Al whether soil pH is governed directly by cations or not. A study was conducted to elucidate the pattern of pH changes by soil EC. Fertilizer and three kinds of organic manures composed of cow and pig and fowl dropping and one kind of rice straw compost were added independently into upland sandy loam soil. This treated soils and four upland soils under plastic film house having different levels in electrical conductivity (EC) were incubated with field capacity at $30^{\circ}C$ for 5, 10, 20 and 40 days. Soil pH varied directly as the cations contained in organic materials according to degree of saturating pH buffer capacity (pBC) of sandy loam soil. pH of the soils under plastic film house was lowered by soil EC due to governing by overplus of cation beyond pBC.

• Water for future
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• v.16 no.4
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• pp.245-252
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• 1983

Recently river water pollution in Korea is given rise to serious problem in aspect of crop production, drinking well, water contamination and etc. Under these urgent situations, it is prime importance to protect water resources from pollutants. An environmental isotope survey of the groundwater form the shallow alluvial and the underlying crystalline rock aquifer of the Han River Basin has been undertaken, Analysis of the data has I) confirmed the hypothesis that the groundwater from the metropolitan area is recharged from the river whereas that form the non-urbanized region of the Basin is replenished by the infiltrating precipitation; ii) shown that crystalline rock aquifers are recharged by the ground water form the overlying alluvium. Old groundwater is a group of wells with tritium values in the range of 0 to 2 TU. These low values indicate that the water sampled was recharged much ealier, at least a few decades, than the other groundwater samples of higher tritium content. The low values in this region may, in fact, reflect the effect of the impermeable clay layers which impede infilteration from the surface. Stable isotope evidence confirmed that a recharge in the karst area occurs at a significantly greater elevation than that to the alluvial aquifer. An analysis of the tritium level collected over an annual cycle suggests that the residence time of groundwater is probably not more than a few months. There does not appear to be any correlation between the trace level of Zn, Mn and Pb in the groundwater and the mechanism of the recharge.

• 대한공업교육학회지
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• v.34 no.1
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• pp.252-273
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• 2009

Due to the importance of biotechnological literacy, the educational community in fields such as technology education, science education, and agricultural education has acknowledged the importance of biotechnology instruction for secondary school. Although recognized as a content organizer in the field of technology education, the actual teaching of biotechnology has not been broadly implemented in technology education classes. In the perspective of expectancy-value theory, technology teachers' motivation is the key factor for affecting the biotechnology instruction. This study investigates Korean technology teachers' motivational beliefs toward biotechnology and its instruction and their perceived ability and value toward biotechnology learning contents. To measure their motivational beliefs and attitudes, a composite on-line survey (fifteen motivational beliefs items, eight biotechnology content items, and related demographic items) was developed. Based on 114 Korean technology teachers' responses the researcher performed a descriptive analysis, independent t-test, and factor analyses (exploratory and confirmatory factor analysis using M-plus 5.0 and SPSS 16.0). Korean technology teachers' abilities toward eight biotechnology contents indicated lowscores while their values were relatively high. Through the independent sample t-test by two demographic variables (gender and professional development), this study found several significant differences in the perceived value. As a preliminary finding of exploratory factor analysis, fifteen items was separated into two motivational constructs of expectancy (6 items) and value (8 items). One item (item #6) was eliminated due to the cross loading. The final findings of this study may have significant implications for professional development regarding biotechnology and its instruction (both in-service and pre-service training) of technology teachers. Also, the confirmatory facctor analysis supported the preliminary finding. Finally, this study recommends that a validity test for other population, investigation for motivational sub-constructs, and in-depth investigation toward biotechnology instruction.

• Animal Bioscience
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• v.35 no.12
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• pp.1911-1920
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• 2022

Objective: This study was performed to determine the apparent metabolizable energy (AME_n) content of tannin-free red/bronze, white/tan and U.S. No. 2 varieties of grain sorghum for feeding Japanese quail and validate their nutrient profile by evaluating effects on performance and carcass traits with full-substitution of corn. Methods: Experiment 1 determined the AME_n content of red/bronze, white/tan, and U.S. No. 2 grain sorghum varieties fed to mixed-sex Japanese quail (Coturnix japonica) (n = 314) at 3 and 6-weeks of age. Analyses were based on a 2×4 factorial treatment design with age and grain types defining the treatments, and a randomized complete block experiment design with cage and trials defining the block. AME_n values were validated by evaluating the performance and carcass traits of Japanese quail (n = 644) from 1 to 40 days of age in Experiment 2 with birds were fed 1 of 4 complete diets. Statistical analyses were conducted on performance data and select individual carcass trait measurements. Results: Determined AME_n values at 3-weeks of age were 3,524±122.03 (red/bronze), 3,252±122.03 (white/tan), and 3,039±123.44 (U.S. No. 2) kcal/kg. At 6-weeks of age, determined AME_n were 3,373±297.35 (red/bronze), 3,279±297.35 (white/tan), and 2,966±298.64 (U.S. No. 2) kcal/kg. Carcass traits showed live body weight (p = 0.0409) and hot carcass weight (p = 0.0234) were greatest in U.S. No. 2; however, carcass yield (p<0.0001) was lowest. No significant differences were observed among treatments for feed intake, feed conversion ratio, breast weight and breast yield (p>0.05). Conclusion: These studies demonstrated that tannin-free grain sorghum varieties may be a potential alternative to corn in quail diets while maintaining growth performance and carcass parameters.

• Journal of Ginseng Research
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• v.47 no.4
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• pp.561-571
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• 2023

Background: Escalating evidence shows that ginseng possesses an antiaging potential with cognitive enhancing activity. As mountain cultivated ginseng (MCG) is cultivated without agricultural chemicals, MCG has emerged as a popular herb medicine. However, little is known about the MCG-mediated pharmacological mechanism on brain aging. Methods: As we demonstrated that glutathione peroxidase (GPx) is important for enhancing memory function in the animal model of aging, we investigated the role of MCG as a GPx inducer using GPx-1 (a major type of GPx) knockout (KO) mice. We assessed whether MCG modulates redox and cholinergic parameters, and memory function in aged GPx-1 knockout KOmice. Results: Redox burden of aged GPx-1 KO mice was more evident than that of aged wild-type (WT) mice. Alteration of Nrf2 DNA binding activity appeared to be more evident than that of NFκB DNA binding activity in aged GPx-1 KO mice. Alteration in choline acetyltransferase (ChAT) activity was more evident than that in acetylcholine esterase activity. MCG significantly attenuated reductions in Nrf2 system and ChAT level. MCG significantly enhanced the co-localization of Nrf2-immunoreactivity and ChAT-immunoreactivity in the same cell population. Nrf2 inhibitor brusatol significantly counteracted MCG-mediated up-regulation in ChAT level and ChAT inhibition (by k252a) significantly reduced ERK phosphorylation by MCG, suggesting that MCG might require signal cascade of Nrf2/ChAT/ERK to enhance cognition. Conclusion: GPx-1 depletion might be a prerequisite for cognitive impairment in aged animals. MCG-mediated cognition enhancement might be associated with the activations of Nrf2, ChAT, and ERK signaling cascade.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.4
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• pp.301-306
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• 2008

Purpose: Recently, a number of patients needed total thyroidectomy and high dose radioiodine therapy (HD-RAI) get increased more. The aim of this study is to evaluate whether pathological staging (PS) and serum thyroglobulin (sTG) level could replace the diagnostic I-123 scan for the determination of therapeutic dose of HD-RAI in patients with differentiated thyroid cancer. Materials and Methods: Fifty eight patients (M:F=13;45, age $44.5{\pm}11.5\;yrs$) who underwent total thyroidectomy and central or regional lymph node dissection due to differentiated thyroid cancer were enrolled. Diagnostic scan of I-123 and sTG assay were also performed on off state of thyroid hormone. The therapeutic doses of I-131 (TD) were determined by the extent of uptakes on diagnostic I-123 scan as a gold standard. PS was graded by the criteria recommended in 6th edition of AJCC cancer staging manual except consideration of age. For comparison of the determination of therapeutic doses, PS and sTG were compared with the results of I-123 scan. Results: All patients were underwent HD-RAI. Among them, five patients (8.6%) were treated with 100 mCi of I-131, fourty three (74.1%) with 150 mCi, six (10.3%) with 180 mCi, three (5.2%) with 200 mCi, and one (1.7%) with 250 mCi, respectively. On the assessment of PS, average TDs were $154{\pm}25\;mCi$ in stage I (n=9), $175{\pm}50\;mCi$ in stage II (n=4), $149{\pm}21\;mCi$ in stage III (n=38), and $161{\pm}20\;mCi$ in stage IV (n=7). The statistical significance was not shown between PS and TD (p=0.169). Among fifty two patients who had available sTG, 25 patients (48.1%) having below 2 ng/mL of sTG were treated with $149{\pm}26\;mCi$ of I-131, 9 patients (17.3%) having $2{\leq}\;sTG\;<5\;ng/mL$ with $156{\pm}17\;mCi$, 5 patients (9.6%) having $5{\leq}\;sTG\;<10\;ng/mL$ with $156{\pm}13\;mCi$, 7 patients (13.5%) having $10{\leq}sTG\;<50\;ng/mL$ with $147{\pm}24\;mCi$, and 6 patients (11.5%) having above 50 ng/mL with $175{\pm}42\;mCi$. The statistical significance between sTG level and TD (p=0.252) was not shown. Conclusion: In conclusion, PS and sTG could not replace the determination of TD using I-123 scan for first HD-RAI in patients with differentiated thyroid cancer.

• Journal of Sasang Constitutional Medicine
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• v.10 no.1
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• pp.235-252
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• 1998

1. Background and Purpose : I intended to be helpful to understand constitutional symptoms of a disease and an application of the prescription through a clinical study of Taeumin Chongsim Yonja Tang. 2. Methods : I studied 125 patients(62 men and 63 women) treated with Taeumin Chongsim Yonja Tang in constitutional clinic of Dongguk Pundang Oriental Hospital. And then I investigated the characteristics of Chongsim Yonja Tang treated patients, remedial values and side effects. 3. Results : Taeumin Chongsim Yonja Tang was used in all age groups both men and women. There were 60 kinds of chief complaints including numbness of hands and feet, headache and fatigue etc. The distributions of remedial values were slightly improved(60.8%), much improved(15.2%), no improved(24.0%) and there was no aggravated patient. Using the prescription, mostly I prescribed only Taeumin Chongsim Yonja Tang without any changing, and added 2-3 herbs to the prescription according to the symptoms of a disease. Taeumin Chongsim Yonja Tang was affected in remedial values by the period of sufferring from illness, treatment and medication. Side effects were diarrhea, indigestion and so on.

• Journal of radiological science and technology
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• v.33 no.3
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• pp.245-252
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• 2010

This study analyzed speed of sound, impedance, attenuation coefficient in accordance with acoustic characteristic standard of body soft tissue corresponding with Annex DD of IEC standard 60601-2-37(2007) which is about tissue mimicking materials (TMM) synthesized by polyurethane as a main material and new type of n-type scatter materials. This study reached the following conclusion after analyzing and evaluating image characteristic with SONOACE 9900 c PRIME (MEDESON Co.) and brightness, maximum penetration with convex probe (2.5~5.0 MHz). When n-type scatter materials are increasingly synthesised 0~8% with prepolymer as a main material and polyol mixture as a catalyst, 1. The more scatter materials are increased, the more sound speed of TMM becomes closely similar to soft tissue. 2. The more scatter materials are decreased, the more acoustic impedance becomes closely similar to soft tissue. 3. The more scatter materials are increased, the more attenuation coefficient is increased. 4. The more scatter materials are increased, the more average brightness of images is increased, but there is threshold. 5. The maximum penetration becomes closely similar to soft tissue at the 6% TMM as a scatter material.

• Journal of Animal Environmental Science
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• v.16 no.3
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• pp.245-252
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• 2010

Disposal methods of managing carcass in Korea livestock production systems include burying, digesting, rendering, carcass dumping to manure pile, dead animal disposer and mini-incinerator. Burying was usually the most practical method of carcass disposal in our livestock farms. Burying, carcass dumping to manure pile, dead animal disposer and mini-incinerator may have environmental regulatory and economic liabilities when used as a means of carcass disposal. In many cases in this survey, these disposal methods offer a poor choice for the producer due to individual site conditions, geology, cost, air emissions, rendering plants. A survey questionnaire that addressed the issues to livestock producers was prepared. The questionnaire addressed two main topics as follows: 1) types of livestock and generation amounts of carcass 2) Number of breeding animals and disposal methods of livestock mortality. A total of 36 livestock producers were interviewed. The results of obtained in this survey were summarized as follows: The number of breeding poultry, swine, beef cow and dairy cow was 251,000, 2,600, 142 and 92 heads per year and the generation amounts of annually carcass was 0.46, 15.32, 0.36, 1.36 tons per year of each poultry, swine, beef cow and dairy cow farms, respectively. The disposal methods of carcass were burying (42%), carcass dumping to manure pile (36%), rendering (8%), incineration (6%), digesting (6%), carcass disposer (2%), respectively. These results can be used as basic information to establish the standard of carcass composting facility.