• Korean Journal of Environmental Agriculture
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• v.42 no.1
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• pp.1-7
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• 2023

Super absorbent polymers (SAPs) are hydrophilic molecules that can absorb large amounts of water. This study was conducted to investigate the enhancement of the physicochemical properties of sand soil blended with three SAPs imbibed with 100, 150, and 200-fold water. Three treatments were applied, namely, 100SAP, 150SAP, and 200SAP. The three SAPs were blended at concentrations of 0% (control), 3%, 5%, 7%, and 10% with sand. The pH, electrical conductivity, and cation exchangeable capacity (CEC) of soil blended with the three SAPs were pH 6.35-6.46, 0.09-0.65 dS/m, and 1.42-1.92 cmol_c/kg, respectively, and their capillary porosity, total porosity, and saturated hydraulic conductivity were 21.0-29.3%, 39.2-48.7%, and 272-470 mm/hr. CEC, capillary porosity, total porosity, and saturated hydraulic conductivity of soil were positively correlated with the ratio of the SAPs (p<0.01). These results indicate that blending sand soil with SAPs increased CEC, capillary porosity, and saturated hydraulic conductivity, thus improving the nutrient-retention capacity, water-retention capacity, and permeability of the soil.

• Journal of the Korean Geotechnical Society
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• v.24 no.4
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• pp.23-36
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• 2008

This study describes model tests on instrumented rectangular-shaped passive row piles embedded in horizontal sand-ground undergoing lateral soil movement. We tried to find the property of row piles dependent on the shape of pile, including the position of the pile in row, pile spacing, and soil movement. The results of test are as follows. The lateral earth pressure diagram variously appeared to be triangle, trapezoid and rectangular by shape and position of pile. The outer pile has a larger bending moment than the inner pile in the case of B-type, the inner piles has larger one than outer pile in case of H-type. $R_f$ (the ratio of resistance to lateral soil movement) was found to increase with increasing pile spacing irrespective of pile-shape. Y/L (location of action of lateral resistance force) for $d_s$ (displacement of soil) and $S_h$ (spacing of pile) appeared to be nearly regular position, and H-type is higher than B-type.

• Computers and Concrete
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• v.31 no.5
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• pp.433-442
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• 2023

This study presents the visually observed behavior of fibers embedded in concrete samples that were subjected to a flexural bending test. Three types of fibers such as macro polypropylene, macro polyethylene, and the hybrid of steel and polyvinyl alcohol were mixed with cement by a designated mix ratio to prepare a total of nine specimens of each. The bending test was conducted by following ASTM C1609 with a net deflection of 2, 4, and 7 mm. The X-ray computed tomography (XCT) was carried out for 7 mm-deflection specimens. The original XCT images were post-processed to denoise the beam-hardening effect. Then, fiber, crack, and void were semi-manually segmented. The hybrid specimen showed the highest toughness compared to the other two types. Debonding based on 2D XCT sliced images was commonly observed for all three groups. The cement matrix near the crack surface often involved partially localized breakage in conjunction with debonding. The pullout was predominant for steel fibers that were partially slipped toward the crack. Crack bridging and rupture were not found presumably due to the image resolution and the level of energy dissipation for poly-fibers, while the XCT imaging was advantageous in evaluating the distribution and behavior of various fibers upon bending for fiber-reinforced concrete beam elements.

• Advances in concrete construction
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• v.13 no.2
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• pp.123-132
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• 2022

This paper aims to adapt Multilinear regression (MLR) to predict the strength and toughness of SIFCON containing various pozzolanic materials. Slurry Infiltrated Fibrous Concrete (SIFCON) is one of the most common terms used in concrete manufacturing, known for its benefits such as high ductility, toughness and high ultimate strength. Assessment of compressive strength (CS.), flexural strength (F.S.), splitting tensile strength (STS), dynamic elasticity modulus (DME) and impact energy (I.E.) using the experimental approach is too costly. It is time-consuming, and a slight error can lead to a repeat of the test and, to solve this, alternative methods are used to predict the strength and toughness properties of SIFCON. In the present study, the experimentally investigated SIFCON data about various mix proportions are used to predict the strength and toughness properties using regression analysis-multilinear regression (MLR) models. The input parameters used in regression models are cement, fibre, fly ash, Metakaolin, fine aggregate, blast furnace slag, bottom ash, water-cement ratio, and the strength and toughness properties of SIFCON at 28 days is the output parameter. The models are developed and validated using data obtained from the experimental investigation. The investigations were done on 36 SIFCON mixes, and specimens were cast and tested after 28 days of curing. The MLR model yields correlation between predicted and actual values of the compressive strength (C.S.), flexural strength, splitting tensile strength, dynamic modulus of elasticity and impact energy. R-squared values for the relationship between observed and predicted compressive strength are 0.9548, flexural strength 0.9058, split tensile strength 0.9047, dynamic modulus of elasticity 0.8611 for impact energy 0.8366. This examination shows that the MLR model can predict the strength and toughness properties of SIFCON.

• Korean Journal of Poultry Science
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• v.38 no.3
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• pp.213-223
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• 2011

This study was conducted to test the efficacy of plum (Prunus mume) and red ginseng (Panax ginseng C.A Meyer) marc as stress inhibitors under heat stress and lipopolysaccharide (LPS) challenge in broilers by investigating their effects on blood biochemical parameters, immunoglobulin concentration and splenic cytokine mRNA expressions. A total of one hundred ninety-two 1-d-old male broiler chicks (Ross 308) were divided into 2 stress conditions (heat and LPS) experiments. Each experiment was divided into 4 treatment groups with 8 replicates of 3 birds in each group. NC (negative control, no immune substances), PC (positive control, 25 ppm ${\beta}$-glucan), PM (1% plum marc) and RGM (3% red ginseng marc) treatments were administered with respective substance through water supplementation. During heat stress, The Ca/Mg ratio in PM and RGM was significantly decreased in comparison with that of NC (P<0.05). The immunoglobulin M was significantly lower in PM than in NC (P<0.05). Expression patterns of splenic cytokine mRNAs (IL-1, IL-2 and IL-6) were similar over the treatment. Expression rates of IL-1 and IL-2 in PM were significantly decreased in comparison with NC. Also, expression rates of IL-1, IL-2 and IL-6 were significantly lower in RGM than in NC (P<0.05). In conclusion, the dietary supplementation of plum and red ginseng marc improved coping ability to heat stress by preventing Ca/Mg ratio increment and by inhibiting inflammatory response in broiler chicks. However, it is necessary to determine optimal dietary level of red ginseng marc for improving growth performances in broiler chickens. These results suggest the possibility that plum and red ginseng marc could be used as the stress inhibitor under heat stress and inflammatory response in broiler chicks.

• Journal of Sericultural and Entomological Science
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• v.51 no.2
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• pp.173-179
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• 2013

This study was investigation for primary bionomical characteristics, emergence rate of wintering type pupa and oviposition preference, of Papilio xuthus. The emergence rate of wintering type pupa stored at cold chamber($4{\pm}1^{\circ}C$) was 85%, after 10 months. The average emergence rate of wintering type pupa during storage was 89.6%, and the emergence periods were $7.9{\pm}1.9days$ in room temperature. Mating ratio in large oviposition room, $6,000{\times}6,000{\times}3,500$ mm($W{\times}L{\times}H$), was $86.7{\pm}5.8%$ higher than $63.3{\pm}15.3%$ in small room, $2,500{\times}3,000{\times}2,000$ mm($W{\times}L{\times}H$). But the number of eggs in the large room were $137.0{\pm}16.5$ fewer than $141.7{\pm}20.4$ in the small room. As a result of oviposition preference experiment on three different host plants, 10 mated female laid $141.7{\pm}27.8$ on the leaves of Phellodendron amurensew more than $67.7{\pm}20.6$ on Zanthoxylum schinifolium and $77.0{\pm}21.8$ on Citrus unshiu. The egg periods were $4.4{\pm}0.8$ days after oviposition, and the hatchability was 92.2% in $25^{\circ}C$ room condition. The larval period were $19.9{\pm}2.1$ days in the high temperature, long day condition($25^{\circ}C$, 14L : 10D). The headwidth of each developmental larval stage were $0.72{\pm}0.02$(1st), $1.19{\pm}0.02$(2nd), $1.65{\pm}0.05$(3rd), $2.43{\pm}0.07$(4th), $3.21{\pm}0.12$(5th). The pupal ratio was 91.6%. The pupal period were $8.8{\pm}0.9$ days, and the emergence rate was 92.2%.

• Journal of Animal Environmental Science
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• v.17 no.2
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• pp.131-138
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• 2011

This study was carried out to investigate on the composting characteristics variation accoding to air supply capacity in Pig manure. The composting of pig manure is economical and efficiently process. The fermented compost was added in pig manure mixed with sawdust was composting reators. Air supply capacity levels of fermented compost on the pig manure mixed with sawdust were regulated at 50, 100, 150 and 200$\ell/m^3$/min. respectively. The obtained results can be followed as bellow; The temperature variations of experimental composting piles during composting for the different of T-1 reach $40^{\circ}C$ in 2 days, T-2, T-3 and T-4 reach $60^{\circ}C$ in 2 days and T-3, T-4 maintained until 8 days. The decreases in water contents per each square meter for the different of T-1 (50 l/$m^3$/min), T-2(100 l/$m^3$/min), T-3(150 l/$m^3$/min) and T-4(200 l/$m^3$/min.), The decreases ratio in water contents was T-1, T-2, T-3 and T-4 were 15.4%, 28.8%, 33.4% and 35.2%. The decreases ratio in weight was T-1, T-2, T-3 and T-4 were 7.6%, 15.6%, 16.8% and 16.9% respectively. The variations of oxygen concentration from composting period in case of oxygen discharge concentration T-1, T-2, T-3 and T-4 were 9 ppm. respectively. Fertilizer components after composting were examined. Nitrogen contents of the T-1, T-2, T-3 and T-4 were 0.45%, 0.44%, 0.42% and 0.44%, and P2O5 contents were T-1, T-2, T-3 and T-4 were 0.37%, 0.41%, 0.42% and 0.44% respectively. Therefore, the compost curing air supply of air volumes at least 150$\ell$/min/min. or more to supply the aerobic composting pig manure normally are judged to be possible.

• Pediatric Infection and Vaccine
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• v.11 no.2
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• pp.176-182
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• 2004

Purpose : The etiologic agents of aseptic meningitis remain mostly unknown due to difficulty of viral culture and identification. There was an outbreak of aseptic meningitis in northern area of Seoul from June to August, 2002. We report the clinical features, laboratory data and causative viruses on 196 children with aseptic meningitis during this period. Methods : We retrospectively studied about clinical manifestations and laboratory findings 196 patients diagnosed as aseptic meningitis at Sanggye-Paik hospital. Virus isolation and serotype identification were performed by cell culture and reverse transcription polymerase chain reaction(RT-PCR) of the cerebrospinal fluid. Results : The male to female ratio was 1.39 : 1 and the mean age was 5.8+3 years. The clinical manifestations were fever, headache and vomiting. It occurred mostly in June, July and August. The numbers of peripheral blood leukocytes were $4,800{\sim}24,360/mm^3$. On cerebrospinal fluid examinations, leukocytes were in range of 10~2,000(mean 105)/$mm^3$, protein level in range of 15~171(mean 41.4) mg/dL and glucose level from 16~97(mean 57.9) mg/dL. Viral culture of cerebrospinal fluid showed 3 cases of Echovirus 9, 1 case of 25 and 30. In stool culture, 2 cases of Echovirus 6, 2 cases of Echovirus 13 and 1 case of Echovirus 30 were isolated. Conclusion : The etiologic viruses of the aseptic meningitis in northern area of Seoul in 2002 are presumed to be Echovirus 6, 9, 13, 25, 30.

• Journal of the Korean Society of Radiology
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• v.18 no.5
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• pp.523-529
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• 2024

The purpose of this study is to investigate the effect of differences in grid focal distance used in general radiography on the exposure index and image quality, and to provide useful information for the application of grids in clinical radiography. With AEC applied and SID set to 110 cm, 30 images were obtained for each focus distance of the grid at 110 cm, 140 cm, and 180 cm under the same exposure conditions. The dose was measured using the DAP and ESD, while image quality was evaluated using the SNR and CNR. The exposure index (EI) was determined based on the values shown in the image. EI was derived from the values indicated in the images. The mean DAP values at focus distances of 180, 140, and 110 cm were 10.944±0.613, 10.687±0.516, and 9.74±0.588 cGy·cm², respectively. The ESD values were 1041.75±57.92, 1019.99±49.61, and 930.86±55.77 μGy, while the EI values were 205.97±11.77, 210.59±10.37, and 193.8±11.86. The SNR values were 28.48±0.62, 28.41±0.64, and 27.13±0.72 dB, and the CNR values were 0.09859±0.004276, 0.09864±0.004378, and 0.09026±0.004783 dB. The differences in the mean values were statistically significant (p < 0.01). The values were significantly higher at focal distances of 140 cm and 180 cm compared to 110 cm, but there was no significant difference between the focal distances of 140 cm and 180 cm. The correlation analysis results revealed significant negative correlations between FD and DAP (r = -0.642, p < 0.01), ESD (r = -0.629, p < 0.01), EI (r = -0.376, p < 0.01), SNR (r = -0.615, p < 0.01), and CNR (r = -0.575, p < 0.01) for all variables. The results of this study showed a moderate negative correlation between the focus distance of the grid and the SNR, CNR, DAP, and ESD, and a weak negative correlation with the EI. Therefore, radiological technologists should be aware that even when the same exposure conditions are applied using an AEC system, variations in focus distance of the grid can affect the exposure index, dose, and image quality. Careful consideration is needed when setting the target exposure index.

• Journal of Nutrition and Health
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• v.8 no.1
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• pp.15-37
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• 1975

I. Subject of the study A study on the nutritive value and utilization of powdered seaweeds. II. Purpose and Importance of the study A. In Korea the shortage of food will be inevitable by the rapidly growing population. It will be very important study to develop a new food from the seaweeds which were not used hitherto for human consumption. B. The several kinds of seaweeds have been used by man in Korea mainly as side-dishes. However, a properly powdered seaweed will enable itself to be a good supplement or mixture to certain cereal flours. C. By adding the powdered seaweed to any cereals which have long been staple foods in this country the two fold benefits; saving of cereals and change of dietary pattern, will be secured. III. Objects and scope of the study A. Objects of the study The objects will come under four items. 1. To develop a powdered seaweed as a new food from the seaweeds which have been not used for human consumption. 2. To evaluate the nutritional quality of the products the analysis for chemical composition and animal feeding experiment will be conducted. 3. Experimental cocking and accepability test will be conducted for the powdered products to evaluate the value as food stuff. 4. Sanitary test and also economical analysis will be conducted for the powdered products. B. Scope of the study 1. Production of seaweed powders Sargassum fulvellum growing in eastern coast and Sargassum patens C.A. in southern coast were used as the material for the powders. These algae, which have been not used for human consumption, were pulverized through the processes of washing, drying, pulverization, etc. 2. Nutritional experiments a. Chemical composition Proximate components (water, protein, fat, cellulose, sugar, ash, salt), minerals (calcium, phosphorus, iron, iodine), vitamins (A, $B_1,\;B_2$ niacin, C) and amino acids were analyzed for the seaweed powders. b. Animal feeding experiment Weaning 160 rats (80 male and 80 female rats) were used as experimental animals, dividing them into 16 groups, 10 rats each group. Each group was fed for 12 weeks on cereal diet (Wheat flour, rice powder, barley powder, potato powder, corn flour) with the supplementary levels of 5%, 10%, 15%, 20% and 30% of the seaweed powder. After the feeding the growth, feed efficiency ratio, protain efficiency ratio and ,organs weights were checked and urine analysis, feces analysis and serum analysis were also conducted. 3. Experimental cooking and acceptability test a. Several basic studies were conducted to find the characteristics of the seaweed powder. b. 17 kinds of Korean dishes and 9 kinds of foreign dishes were prepared with cereal flours (wheat, rice, barley, potato, corn) with the supplementary levels of 5%, 10%, 15%, 20% and 30% of the seaweed powder. c. Acceptability test for the dishes was conducted according to plank's Form. 4. Sanitary test The heavy metals (Cd, Pb, As, Hg) in the seaweed powders were determined. 5. Economical analysis The retail price of the seaweed powder was compared with those of other cereals in the market. And also economical analysis was made from the nutritional point of view, calculating the body weight gained in grams per unit price of each feeding diet. IV. Results of the study and the suggestion for application A. Chemical composition 1. There is no any big difference in proximate components between powders of Sargassum fulvellum in eastern coast and Sargassum patens C.A. in southern coast. Seasonal difference is also not significant. Higher levels of protein, cellulose, ash and salt were found in the powders compared with common cereal foods. 2. The levels of calcium (Ca) and iron (Fe) in the powders were significantly higher than common cereal foods and also rich in iodine (I). Existence of vitamin A and vitamin C in the Powders is different point from cereal foods. Vitamin $B_1\;and\;B_2$ are also relatively rich in the powders.'Vitamin A in ·Sargassum fulvellum is high and the levels of some minerals and vitamins are seemed4 to be some influenced by seasons. 3. In the amino acid composition methionine, isoleucine, Iysine and valine are limiting amino acids. The protein qualities of Sargassum fulvellum and Sargassum patens C.A. are seemed to be .almost same and generally ·good. Seasonal difference in amino acid composition was found. B. Animal feeding experiment 1. The best growth was found at.10% supplemental level of the seaweed Powder and lower growth rate was shown at 30% level. 2. It was shown that 15% supplemental level of the Seaweed powder seems to fulfil, to some extent the mineral requirement of the animals. 3. No any changes were found in organs development except that, in kidney, there found decreasing in weight by increasing the supplemental level of the seaweed powder. 4. There is no any significant changes in nitrogen retention, serum cholesterol, serum calcium and urinary calcium in each supplemental level of the seaweed powder. 5. In animal feeding experiment it was concluded that $5%{\sim}15%$ levels supplementation of the seaweed powder are possible. C. Experimental cooking and acceptability test 1. The seaweed powder showed to be utilized more excellently in foreign cookings than in Korean cookings. Higher supplemental level of seaweed was passible in foreign cookings. 2. Hae-Jo-Kang and Jeon-Byung were more excellent than Song-Pyun, wheat cake, Soo-Je-Bee and wheat noodle. Hae-Je-Kang was excellent in its quality even as high as 5% supplemental level. 3. The higher levels of supplementation were used the more sticky cooking products were obtained. Song-Pyun and wheat cake were palatable and lustrous in 2% supplementation level. 4. In drop cookie the higher levels of supplementation, the more crisp product was obtained, compared with other cookies. 5. Corn cake, thin rice gruel, rice gruel and potato Jeon-Byung were more excellent in their quality than potato Man-Doo and potato noodle. Corn cake, thin rice gruel and rice gruel were excellent even as high as 5% supplementation level. 6. In several cooking Porducts some seaweed-oder was perceived in case of 3% or more levels of supplementation. This may be much diminished by the use of proper condiments. D. Sanitary test It seems that there is no any heavy metals (Cd, Pb, As, Hg) problem in these seaweed Powders in case these Powders are used as supplements to any cereal flours E. Economical analysis The price of the seaweed powder is lower than those of other cereals and that may be more lowered when mass production of the seaweed powder is made in future. The supplement of the seaweed powder to any cereals is also economical with the criterion of animal growth rate. F. It is recommended that these seaweed powders should be developed and used as supplement to any cereal flours or used as other food material. By doing so, both saving of cereals and improvement of individual's nutrition will greatly be achieved. It is also recommended that the feeding experiment for men would be conducted in future.