• Korean Journal of Materials Research
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• v.8 no.8
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• pp.766-774
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• 1998

32$0^{\circ}C$, 40%NaOH 용액의 autoclave에서 약 300wppm의 탄소를 함유하고 있는 15Cr-9Fe-balanced Ni 합금 판상시편에 대해 응력부식 저항성을 조사하였다. 부식시편은 $700^{\circ}C$, 100시간 동안의 열처리로 합금내부에 석출될 수 있는 가능한 한 많은 양의 크롬계 탄화물을 석출시킨 후, 다시 재용해에 의해 크롬계 탄화물의 형태를 조절하는 $800^{\circ}C$-$950^{\circ}C$범위의 최종열처리를 시행하고 급냉시킨 다음 U-자형으로 응력을 가하여 준비되었다. 최종열처리 온도가 올라감에 따라 시편들의 입계응력부식균열(IGSCC ) 전파속도는 $900^{\circ}C$까지는 거의 직선적으로 증가하다가 $950^{\circ}C$에서는 $700^{\circ}C$에서 얻은 값보다도 더 낮게 감소하였다. 즉, 크롬계 탄화물이 재용해되어 그 밀도가 감소함에 따라 IGSCC저항성이 감소하다가 완전히 재용해된 $950^{\circ}C$ 열처리 조건에서 오히겨 가장 큰 IGSCC 저항성을 나타내었다. 이와같은 최조열처리 온도에 따른 니켈계 합금 600의 부식거동은 입계에 존재하는 크롬계탄화물의 형태변화 때문이 아니라 입계에서 탄소-크롬계 탄화물-크롬간의 상평형에 의해 이루어지는 탄소의 입계편석량이 크롬계탄화물이 존재할 때에는 열처리 온도에 따라 증가하다가 그것이 완전히 재용해 되었을 때 가장 낮아지기 때문인 것으로 생각된다.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6523-6526
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• 2012

Objective: This study was designed to investigate treatment efficacy and side effects of concomitant Aisu$^{(R)}$ (docetaxel) with three-dimensional conformal external beam radiotherapy for the treatment of inoperable patients with esophageal cancer. Methods: Inoperable patients were treated with three-dimensional conformal external beam radiotherapy (5/week, 2 GY/day, and total dose 60GY) plus docetaxel ($30-45mg/m^2$, iv, d1, 8). Results: Twenty eight patients met the study eligibility criteria and the response rate was evaluated according to RICIST guidelines. Among 28 patients, 2 achieved CR, 22 PR, 3 SD and 1 patient was documented PD. Mild gastrointestinal reaction and bone marrow suppression were also documented. All treatment related side effects were tolerable. Conclusion: Three-dimensional conformal external beam radiotherapy combined with docetaxel is an active and safe regimen for inoperable patients with esophageal cancer.

• The Journal of Korean Physical Therapy
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• v.14 no.4
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• pp.423-440
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• 2002

The purpose of this study is to investigate the conception and developmental process of stretching in sports physical therapy. This study is to find conception of stretching, feature and effect, principles and fundamental rule, consideration of enforcement and developmental process in order to use the basic material which is very helpful in the every field and the scene of sports needing stretching. Flexibility is the ability to move muscles and joints through their full ranges of motion. Flexibility is developed by stretching. About player who insufficiency of flexibility, patient and disabled person who restrict of range of motion, older adult who reduce of flexibility, promote of flexibility for upgrading stability and efficiency of body on the based of scientific principles is completed by stretching. The method of stretching has been developed with passive stretching, CR, PNF stretching, PIC stretching, MET stretching in the order. The effects that we can get through stretching are as follows : 1. Enhance physical fitness. 2. Optimize learning, practice and performance of many types of skilled movement. 3. Increase mental and physical relaxation. 4. Promote development of body awareness. 5. Reduce risk of joint sprain or muscle strain. 6. Reduce risk of back problem. 7 Reduce muscular soreness. 8. Reduce the severity of painful menstruation for female athletes. 9. Reduce muscular tension. 10. Advance recognition of body.

• Korean Journal of Digital Imaging in Medicine
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• v.13 no.4
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• pp.165-169
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• 2011

The purpose of this study is to compare the measurement result of radiation dose by using standard thoracic phantom and ionization chamber to advice proposal in the shooting condition of chest PA projection at hospitals recently. And to understand the change between radiation dose and resolution in different conditions. The period this study was from August 2010 to September 2010 and the subjects of the study was 3 general hospitals, 4 personal hospitals and 1 laboratory at the college. Finally we study with 6 DR, 1 CR, and 4 F/S equipments. Most hospitals met advice proposal, but some of the hospitals exceed advice dose from the result of our study. We can lower radiation dose about 25% when kVp is lowered about 20% in DR equipment. And we can lower radiation dose about 50% when mAs is lowered about 35%. The image quality was similar to the original in the study. Most hospitals which exceed advice dose were personal hospitals. The reason why it happened is that radiation dose for chest PA projection at personal hospitals is higher than general hospitals and the personal hospitals' equipments are older than general hospitals' equipments. We guess that patients' radiation dose of chest PA projection can be lowered from the result.

• Journal of Environmental Science International
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• v.30 no.12
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• pp.1081-1092
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• 2021

In this study, the effect on the stability of Aerobic Granular Sludge (AGS) caused by an AGS separator was investigated. The AGS separator was a hydrocyclone. The main factors of the AGS separator were filter pore size (0.125~0.600 mm), conical-to-cylindrical ratio (1.5~3.0), and operating time (1~20 min). The AGS/mixed liquor suspended solid (MLSS) ratio gradually increased to 0.500 mm (AGS/MLSS: 84.3±3.0%). AGS was best separated at the conical-to-cylindrical ratio of 2.5 (AGS/MLSS: 84.7±3.3%). As the operating time increased, the AGS separation performance also tended to increase. The shortest AGS separator run time, but the highest AGS separation performance was 10 min (87.0±2.5%). AGS stability was evaluated by operating the selected AGS separator and sequencing batch reactor. The average removal efficiencies of TOC, TCOD_Cr, SS, TN, and TP were 95.7%, 96.9%, 93.0%, 89.0%, and 96.2%, respectively, which met the effluent standards in Korea. In addition, the AGS/MLSS ratio tended to remain constant, and the sludge volume index demonstrated a tendency to decrease from 140 mL/g to 70 mL/g. During the operation, the particles of AGS in optical microscope observations gradually increased.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.7
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• pp.488-494
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• 2012

This study was conducted to determine the optimal ratio of sludges from milk processing industry (MPS), paper-mill industry (PMS) and night-soil treatment plant (NSS) for vermicomposting. Five different ratios, 0 : 80 : 20 (MPS-0), 25 : 60 : 15 (MPS-25), 50 : 40 : 10 (MPS-50), 75 : 20 : 5 (MPS-75), and 100 : 0 : 0 (MPS-100 : control) MPS : PMS : NSS by wet weight were tested in a small plot experiment. The experiment for each mixing ratio was performed for 2 weeks with the three replications. MPS-100 (100 : 0 : 0) only had the highest decomposition rate with 19.9%, followed by MPS-25, MPS-50, MPS-75 and MPS-0 with 19.5, 19.1, 17.6 and 16.7%, respectively. Except for MPS-100, Vermicomposting resulted in increase in ash, T-P, $NO_2{^-}-N$, $NO_3{^-}-N$, Mg, K, As, Cd and Cu, whereas moisture, VS (Volatile Substance), TKN (Total Kjeldahl Nitrogen), $NH_4{^+}-N$, Ca, Hg and Pb were lower in the final cast than the initial feed mixture. Meanwhile Zn showed very slight difference and Cr and Ni did not show any tendency between the feed mixture and the final cast. In the case of MPS-100, where the decomposition rate was the highest, all the heavy metals in the final cast except for Hg were increased. All the vermicomposts produced from five different mixing ratios of the vermicomposting sludges met the Korea Standard as by-product compost.

• Journal of environmental and Sanitary engineering
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• v.16 no.4
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• pp.77-89
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• 2001

The research is intended to evaluate the soil pollution quality of Chungbuk province with Soil Network which is executed every year. The survey executed with Soil Network in 1999 represented that the soil quality of Chungbuk province was relatively good as the average concentrations of contaminants in soil were Cd: 0.146 mg/17g, Cu: 3.143 mgHg, As: 0.636 mg/kg, Hg: 0.012 mg/kg, Pb): 4.505 mg/kg, $Cr^{+6}$ not detected, and the average pH was 6.1. The reckoned soil Pollution score (SPS) of Chungbuk province has been shown much low SPS distribution in the range from 1.6 to 141.7, average 31.0. However, it has been represented relatively high SPS distribution at Chungju, Tanyang, and Chinchon, respectively, It also huts represented high SPS distribution not only at agricultural area and waste area for the Pollution sources but at a paddy field and dry field for land use. The classification of soil pollution class(SPC) based on soil pollution score(SPS) was SPC 1 under 100 of SPS at 212 areas which were 98.6% of total 215 areas and SPC 2 over 100 of SPS at only three area left. There was no area exceeding soil pollution value among the whole Soil Network areas investigated, and the whole average for each items was much lower level th퍼n soil Pollution value was. When the average concentration of heavy metals and the average pH in soil of Chungbuk province are compared with the natural contents of that in Korea, the research is concluded that the average concentration of heavy met is relatively similar to the natural contents of that and the average pH in soil of Chungbuk province is a little higher than the natural contents of that. From this method, soil quality of most of the Soil Network area was estimated to be healthy.

• Environmental Engineering Research
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• v.11 no.6
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• pp.311-317
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• 2006

Feasibility of destroying synthetic and actual leachate containing humic acids and ammonia compounds by supercritical water oxidation (SCWO) was evaluated. In this study, destruction efficiencies of humic acids and ammonia respectively were investigated at various reaction temperatures and residence times under pressure a supercritical pressure (280 atm). To lower reaction temperature, chemical oxidants were used. The experiment was carried out in a cylindrical batch reactor made of Hastelloy C-276 that can withstand high temperature and pressure. Concentrations of humic acids and ammonia were measured using a $COD_{Cr}$ method and an ammonia selective electrode, respectively. The optimal destructive condition of humic acids in the presence of stoichiometric oxygen(air) was 3 min at $380^{\circ}C$, but the temperature could be lowered to subcritical region ($360^{\circ}C$) along with $H_2O_2$ as an oxidant. For ammonia, the optimal destructive condition with air was 5 min at $660^{\circ}C$, but it was possible to operate the process for 3 minutes at $550^{\circ}C$ or 2 min at $600^{\circ}C$ along with $H_2O_2$ as an oxidant. At 2 min and $550^{\circ}C$ along with $H_2O_2$ as an oxidant, humic and ammonia compounds in the actual leachate were easily destructed and the effluent quality met the Korea Standard Leachate Quality.

• Journal of the Korean Wood Science and Technology
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• v.48 no.3
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• pp.271-282
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• 2020

Sewage treatment plants are social infrastructure of cities. The sewage distribution rate in Korea is reaching 94% based on the sewage statistics based in the year of 2017. In Korean sewage treatment plants, use of PAC (Poly Aluminum Chloride) accounts for 58%. It contains a large amount of impurities (heavy metal) according to the quality standards, however, there have been insufficient efforts to reinforce the standards or technically improve the quality, which resulted in secondary pollution problems from injecting excessive coagulant. Also, the increase in the use of chemicals is leading to the increases in the annual amount of sewage sludge generated in 2017 and the need to reuse sludge. As such, this study aims to verify the possibility of reusing sludge by evaluating the stability of heavy metals based on the injection of coagulant mixture during water treatment which uses the torrefield wood powder and natural materials, and evaluating the sedimentation and heating value of sewage sludge. As a result of analyzing heavy metals (Cr, Fe, Zn, Cu, Cd, As, Pb, and Ni) from the coagulant mixture and PAC (10%), Cr, Cd, Pb, Ni, and Hg were not detected. As for Zn, while its concentration notified in the quality standards for drinking water is 3 mg/L, only a small amount of 0.007 mg/L was detected in the coagulant mixture. Maximum amounts of over double amounts of Fe, Cu, and As were found with PAC (10%) compared to the coagulant mixture. Also, an analysis of sludge sedimentation found that the coagulant mixture showed a better performance of up to double the speed of the conventional coagulant, PAC (10%). The dry-basis lower heating value of sewage sludge produced by injecting the coagulant mixture was 3,378 kcal/kg, while that of sewage sludge generated due to PAC (10%) was 3,171 kcal/kg; although both coagulants met the requirements to be used as auxiliary fuel at thermal power plants, the coagulant mixture developed in this study could secure heating values 200 kal/kg higher than the counterpart. Therefore, utilization of the coagulant mixture for water treatment rather than PAC (10%) is expected to be more environmentally stable and effective, as it helps generating sludge with better stability against heavy metals, having a faster sludge sedimentation, and higher heating value.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.7
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• pp.1148-1155
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• 2020

Objective: The objective was to determine standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA) in cereal grains and various co-products fed to growing pigs. Methods: Ten feed ingredients tested were barley (9.3% CP), lupin kernels (31.1% CP), and wheat (11.3% CP) as cereal grains, and 2 sources of corn gluten feed produced in China (21.6% CP) and Korea (24.6% CP), corn gluten meal (65.3% CP), lupin hulls (11.6% CP), rice bran (14.5% CP), soybean meal (44.8% CP), and wheat bran (15.4% CP) as co-products. Ten experimental diets were formulated to contain each ingredient as a sole source of N and an N-free diet was used to correct basal endogenous losses of CP and AA. All diets also contained 0.5% Cr₂O₃ as an indigestible index. A replicated 11×6 incomplete Latin square design with 11 dietary treatments, 6 periods, and 22 animals was employed. Twenty-two barrows with an initial body weight of 64.6±4.9 kg were equipped with a T-cannula in the distal ileum. An experimental period consisted of a 4-d adaptation period and a 2-d collection period. Results: The SID of CP in the barley, lupin kernels, wheat, 2 sources of corn gluten feed, corn gluten meal, lupin hulls, rice bran, soybean meal, and wheat bran were 84.7%, 90.5%, 90.4%, 77.4%, 74.6%, 89.5%, 90.4%, 74.4%, 86.9%, and 63.4% (standard error of the mean [SEM] = 5.3, p = 0.006), respectively. The respective SID values of Lys were 75.5%, 88.4%, 83.9%, 74.7%, 62.4%, 80.3%, 83.9%, 78.5%, 88.0%, and 71.2% (SEM = 3.3, p<0.001), and the SID values of Met were 83.6%, 88.7%, 89.4%, 85.7%, 78.3%, 88.9%, 89.4%, 85.3%, 91.1%, and 77.0% (SEM = 2.4, p<0.001), respectively. Conclusion: The ileal digestibility of protein and amino acids varies among the feed ingredients fed to pigs.