• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.12
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• pp.1077-1082
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• 2008

To fabricate a multi-layered piezoelectrics/electrodes structure, the piezoelectrics should be sintered at the temperature lower than $950^{\circ}C$ to use the silver electrode, which is cheaper than the electrodes containing noble metals such as Pd and Pt. Therefore, in this study, we modified the composition of $Pb(Zr,Ti)O_3$-based material as $(Pb_{0.98}Cd_{0.02})(Ni_{1/3}Nb_{2/3})_{0.25}Zr_{0.35}Ti_{0.4}O_3$ to lower the sintering temperature and to improve the piezoelectric properties. Small amount of $MnCO_3$, $SiO_2$, and $Pb_3O_4$ were also added to lower the sintering temperature of the ceramic. The prepared raw powders were mixed by using a ball mill for 24 hours. And then the mixed powders were calcinated for 2 hours at $800^{\circ}C$. The calcinated powders were again crushed with the ball mill for 72 hours. The final powders were pressed for making the shape of ${\emptyset}15\;mm$ disk. The disk-type samples were sintered at temperature range of $850{\sim}950^{\circ}C$. The crystal phases of the sintered specimens were perovskite structure without secondary phases. All of the measured electrical properties such as electromechanical coupling coefficients ($k_p$), mechanical quality factors ($Q_m$), and piezoelectric charge constants ($d_{33}$) were decreased with decreasing the sintering temperatures. The electrical properties measured at the sample sintered at $950^{\circ}C$ were 54% of $k_p$, 503 of $Q_m$, and 390 pC/N of $d_{33}$, respectively. These properties were considered to be fairly good for the application of multi-layered piezoelectric generators or actuators.

• Korean Journal of Food Science and Technology
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• v.28 no.4
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• pp.702-706
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• 1996

Husked barley contained 17.2% dietary fiber and naked barley contained 14.9% dietary fiber. The barley was ground in a Udy cyclotec mill having a 0.5 mm screen and sieved with a 400-mesh screen (38 m openings). Coarse material of naked barley retained by the screen, with a weight yield of 54.1%, contained 7.0% soluble dietary fiber, 13.9% insoluble dietary filer and 20.9% total dietray fiber. As the naked barley flour level increased in bread baking, the water absorption, mixing time, and loaf weight increased, but the loaf volume decreased. Barley flour was added to wheat flour at a replacement level of 10% without a large adverse effect on bread quality, and the dietary fiber content of bread was increased from 3.0% to 5.0%. The soluble dietary fiber content was not changed, but the insoluble dietary fiber content was increased during the baking process.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.2
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• pp.37-42
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• 2008

Defects of corrugated board were limiting factors to the corrugated industry's growth. On-line detecting systems of defects are beneficial to increase profits of the corrugated board companies by reducing base paper consumption, increasing process reliability, and increasing productivity. By replacing naked eye inspection of defects to a defects detecting system, continuous inspection without fatigue may guarantee final products quality. The system was developed, which was consisted of line scan CCD camera, lens, illuminating parts, high speed image processor, software, various input parts, and output parts. First installation location of the system was at before fluting process after base paper unwinding, and surface of liner board was inspected by the system. Second installation location was after fluting process and combining process for liner board. Production loss includes ragged appearance of edge, irregular flute shape, wrong combination of flute, score cracking, defects in base paper, and flute cracking. The production loss was analyzed before and after the system installation at a commercial domestic mill. The production loss ratio was defined as a production loss weight per total production weight. The production loss ratio before the installation was decreased a lot from 1.28%(during 3 months before installation) to 0.76%(during 12 months after the first installation) and to 0.25%(during 6 months after the second installation).

• Food Science of Animal Resources
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• v.30 no.5
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• pp.755-763
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• 2010

Sausages were prepared with fresh chicken breast meat and pork back fat, and formulated with different amounts of added chestnut (Castanea sativa Mill.) peel and ice water to study the effect on the products. The chicken emulsion sausages formulated with 1%, 2%, and 3% added chestnut peel powder were higher in moisture and ash content, and lower in energy values. The cooking loss, emulsion stability, and viscosity of the sausages were improved by the addition of chestnut peel. The fat content, pH, lightness, hardness, and springiness of the chicken emulsion sausage decreased as the amount of chestnut peel levels increased. The chicken emulsion sausages containing 1% and 3% chestnut peel had a higher overall acceptability than the control.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.6
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• pp.964-968
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• 2013

This study investigated the formation of rice dumpling skins with various food additives to improve their texture. Rice (Millyang260 and Hanarum) was obtained from the Rural Development Administration. Rice was milled through an air classifying mill (ACM), and hydroxypropyl methylcellulose (HPMC), xanthan gum, guar gum, carrageenan, or propylene glycol alginate (PGA) was used as food additives. The effects of hydrocolloids on textural were evaluated and rice dumpling skin prepared with additives showed significantly higher values than the control for cooking properties and texture. The presence of hydrocolloids in rice dumpling skin appeared to decrease its weight and volume after cooking. Textural properties of rice dumpling skin with hydrocolloids were similar to the control regardless of cooking condition.

• Composites Research
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• v.31 no.4
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• pp.151-155
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• 2018

Mechanical joint and adhesive joint are two typical joining methods for structures. The adhesive joints distribute the load over a larger area than mechanical joints and have excellent fatigue properties. However, the strength of adhesive joint greatly depends on the environmental conditions and the skill of the operator. Therefore, there is a need for techniques to evaluate the quality of the adhesive joints. The electric resistance method is a very promising technique for detecting defects by measuring the electrical resistance of an adhesive joint in which CNTs are dispersed in an adhesive. In this study, Aluminium-Aluminium adhesive single lap joint specimens were fabricated by using the adhesive dispersing CNTs using a sonicator and a 3-roll mill, and the static strengths and defect detection capabilities of the joints using the electrical resistance method were evaluated according to the CNTs content.

• Environmental Engineering Research
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• v.15 no.3
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• pp.163-166
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• 2010

Pulp and paper mill wastewater has been treated by biological treatment, but the secondary effluent still contains high lignin, chemical oxygen demand, color and total dissolved solids. Tertiary treatment by land application, referred to as 'Project Green,' has been implemented to treat such high quantities of undesirable matters. The impacts of seepage from Project Green diffusing into receiving streams on the water quality and fish pen aquaculture were studied via the integration of technical and social approaches. The determination of the water quality was performed for 13 sampling stations along the receiving stream, including the Chot stream, Chot lagoon and the Pong River. The water quality was generally at normal levels, with the exception of total dissolved solids. The levels of matter were higher at the Chot stream, but became more diluted at the Chot lagoon and the Pong River, respectively. The social approach was conducted through the voluntary participation of the villagers as research assistants for the fish aquaculture study. Fish could grow at three fish pens within the study sites at the location of Project Green, the Chot lagoon and the Pong River. Fish growth at the Chot lagoon was better at the site of Project Green and the Pong River. The integration of technical and social approaches was a meaningful tool not only for the technical feasibility but in helping to solve the conflict between the community and industry.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.1
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• pp.43-49
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• 2018

The aim of the research is to analyze the feasibility of rapid quality evaluation method for blast furnace slag using hydrometer based on the former research of the prediction method for concrete compressive strength using hydrometer. Using this method, it is expected to provide a new application for blast furnace slag quality evaluation easily and rapidly during the receiving inspection. According to the experimental results, the settling time period of hydrometer was delayed with increased fineness of blast furnace slag. By using the regression equation of y = 198 120 x - 193 936(R=0.9398) obtained from the correlation between density of suspension at three minutes and fineness, it was possible to evaluate the quality of blast furnace slag fineness rapidly. Therefore, for ready-mixed concrete receiving inspection, the suggested method can be used as a cheap, a simple, and a rapid inspection method.

• Journal of Environmental Health Sciences
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• v.36 no.6
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• pp.472-479
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• 2010

The purpose of this study was to investigate the concentration of indoor air pollutants at 63 elementary schools, 41 middle schools and 51 high schools in Ulsan from the beginning of May to the end of December, 2008. To assess the indoor air quality of the various classrooms, the 8 indoor air pollutants such as $CO_2$, CO, $NO_2$, $O_3$, $PM_{10}$, TVOCs, HCHO and TBC were measured and analyzed. The mean concentrations of $PM_{10}$ and TBC in the elementary schools were significantly higher than those of middle and high schools (p < 0.01). For the HCHO, the multi-use practice rooms showed an average 1.5 times higher than general classrooms. In schools located in urban areas, the concentrations of CO, $O_3$, $PM_{10}$, HCHO and TBC were lower than in the vicinity of industrial complexes. The exceeding rate of the school air quality maintenance limits in the 6 air pollutants by law were 6.7%, 3.5%, 1.7%, 18.2%, 13.0% and 18.4% for $CO_2$, $NO_2$, $O_3$, $PM_{10}$, HCHO and TBC, respectively. Based on these results $PM_{10}$ and TBC have to be in the order of priority of need to improve the classroom air quality in elementary school of Ulsan.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.4
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• pp.545-551
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• 2005

A feeding trial was conducted to determine whether dietary vitamin C (200 mg/kg) and vitamin E (250 mg/kg) prevent any drops in egg shell quality under heat stress in broiler breeder hens. One hundred and sixty molted Ross broiler breeders were housed randomly in an individual cage at 83 weeks of age. Four dietary treatments with forty hens and four replications per treatment were control (no additional vitamins), vitamin C-, or vitamin E-supplemented and combined supplementation of the two vitamins. After a tenday-adaptation period at 25$^{\circ}C$, the ambient temperature was kept at 32$^{\circ}C$ for a three-week-testing period. Egg production dropped dramatically over week but it did not show a significant change among treatments (p<0.05). However, egg quality parameters such as egg weight, specific gravity, shell thickness, SWUSA, puncture force and shell breaking strength from the birds fed the diet with the combined vitamins C and E were significantly improved over those of the control group during the heat stress period (p<0.05). The hens fed the vitamin C diet improved tibia breaking strength (37.16 kg), statistically higher than the birds fed the control and the vitamin E diets (p<0.05). The hens fed the control diet showed higher serum corticosterone levels, a mean of 5.97 ng/ml, than those of the other treatments (p<0.05). The heat stress resulted in elevated heterophils and decreased lymphocytes in serum, increasing the H/L ratios for all the treatments. However, the increases in H/L ratios were alleviated by feeding the diets containing vitamin C alone or together with vitamin E, although there were no significant differences in the ratio between the two groups (p<0.05). In conclusion, vitamins C (200 mg/kg) and/or E (250 mg/kg) supplemented to the diets for broiler breeder hens could prevent drops in egg shell quality and tibia bone strength under highly stressful environmental temperatures.