Effect of Mn and C on Age Hardening of Fe–Mn–Al–C Lightweight Steels

Sung‑Won Park,Jun Young Park,Kyong Mox Cho,Jae Hoon Jang,Seong‑Jun Park,Joonoh Moon,Tae‑Ho Lee,Jong‑Ho Shin 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.3

The effects of Mn and C content on the age hardening of Fe–Mn–Al–C lightweight steels, which have austenitic or duplex(austenite and ferrite) microstructures, were investigated. An increase in Mn content induced a delay of the age hardeningthat is caused by the formation of intra-granular κ-carbides. In order to interpret the effect of Mn content, first-principlescalculations were conducted using the supercells of Fe24Al8C8,Fe24Al8C7,Fe24(Al7Mn)C8, and Fe24(Al7Mn)C7. The calculationsshowed that an increase in Mn content could be the source of the delay of the intra-granular κ-carbide formation bysuppressing C atom’ occupation of the vacancy at the body-centered site of L12. An increase in C content accelerated theformation of intra-granular κ-carbides, which induced the intense age hardening, and coarse inter-granular κ-carbides, whichresulted in significant decrease in impact absorbed energy due to inter-granular fracture.

Productivity Loss of Rheumatoid Arthritis Patients according to the Their Stages of the Disease Activity Score

( Sang-Cheol Bae ),( Jin-Hye Cha ),( Jung-Yoon Choe ),( Sung Jae Choi ),( Soo-Kyung Cho ),( Won-Tae Chung ),( Chung-Il Joung ),( Young-Ok Jung ),( Young Mo Kang ),( Dong-Wook Kim ),( Jinseok Kim ),( Y 대한류마티스학회 2018 대한류마티스학회지 Vol.25 No.2

Objective. Productivity loss was compared by 3-stage of disease activity and associations between higher disease activity and high productivity loss were identified. Methods. Data were extracted from Rheumatoid Arthritis (RA) Patient-reported Outcomes Research, which enrolled 2,000 RA patients (>20-year) on disease-modifying-antirheumatic-drugs (DMARDs) (≥ 6-month) from December 2012 to June 2013. This included 1,457 RA patients with the disease activity score (DAS-28-ESR) in their medical charts. Productivity loss in time and indirect cost was estimated using The World Health Organization Health and Work Performance Questionnaire (HPQ). Baseline characteristics and productivity loss outcomes were compared according to DAS-28-ESR groups. Results. 84.4% were females, 54.2% had low DAS-28-ESR (<3.2), and 38.2% and 7.6% had moderate (3.2∼5.1) and high DAS-28-ESR (>5.1). Patients with moderate to high DAS-28-ESR had higher lost productivity time (LPT) and monthly costs of LPT than those with low DAS-28-ESR (time in hours: 110.0±58.4 vs. 132.4±57.2 vs. 71.5±52.0, p<0.0001; monthly costs of LPT in 1,000 Korean won: 1,097±607 vs. 1,302±554 vs. 741±531, p<0.0001). Multiple regression analyses revealed significant associations with high LPT in high (adjusted odds ratio [OR]=3.87, 95% confidence interval [CI]: 2.18∼6.87) and moderate DAS-28-ESR (adjusted OR=1.88, 95% CI: 1.41∼2.52) compared to low DAS-28-ESR. In addition, positive associations with high monthly costs of LPT were observed in high (adjusted OR=3.45, 95% CI: 1.98∼5.99) and moderate DAS-28-ESR (adjusted OR=1.93, 95% CI: 1.43∼2.54) compared to low DAS-28-ESR. Conclusion. Timely therapeutic strategies should be taken into consideration given that the RA patients with moderate to high DAS-28-ESR showed strong associations with high productivity loss for effective management of RA. (J Rheum Dis 2018;25:122-130)

3분과 : 가선집재작업에서의 작업 생산성 및 비용 분석

한원성 ( Won Sung Han ),한한섭 ( Han Sup Han ),김남훈 ( Nam Hun Kim ),차두송 ( Du Song Chu ),조구현 ( Koo Hyun Cho ),민도홍 ( Do Hong Min ),권기철 ( Ki Cheol Kwon ) 한국임학회 2014 한국산림과학회지 Vol.103 No.1

본 연구에서는 임목수확작업에 사용되는 집재기계의 작업효율성을 분석하여 경사가 급한(20° 이상) 작업조건에 적합한 가선계 집재기계를 선정하는데 기초 정보를 제공하고자, 타워야더(RME-300T), 트랙터부착형 집재기(일명: 춘천집재기), 트랙터윈치(FARMI) 등에 의한 집재작업에서의 작업생산성 및 비용을 비교 분석하였다. 평균 흉고직경이 20 cm, 집재거리 60 m, 가로집재거리 10 m, 그리고 기계이용률이 70%인 동일한 작업 조건에서 작업이 이루어질 경우, 타워야더의 1일 집재작업 생산성은 33.04 m3/일, 트랙터부착형 집재기는 38.47 m3/일, 그리고 트랙터윈치는 14.17 m3/일으로 분석되었으며, 이에 따른 집재작업비용은 각각 25,105원/m3, 20,520원/m3, 37,835원/m3으로 나타났다. 동일한 작업조건에서 집재거리에 따른 각 집재기계별 작업효율성을 비교하였을 경우, 집재거리가 40 m 이내로 짧을 경우에는 트랙터윈치에 의한 집재작업이 효율적이며, 40~140 m의 집재거리에서는 춘천집재기가, 140 m 이상의 장거리 집재작업에서는 타워야더가 가장 효율적인 것으로 나타났다. This study was conducted to provide field-based harvesting study information which can be used to select an optimal cable system for certain work conditions on steep grounds (>20° ground slope) in Korea. Toaccomplish this study objectives, we evaluated three cable yarding systems (RME-300T tower-yarder, Chuncheontower-yarder, FARMI tractor winch) working in typical work conditions for their yarding productivity and operational efficiency. Those yarders are commonly used for removing logs or trees on steep grounds in Korea. Under the same work conditions (average DBH of tree to be cut, 20 cm; yarding distance, 60 m; lateral yardingdistance, 10 m; and machine utilization rate, 70%), the average productivities were 33.04 m3/day, 38.47 m3/day, and 14.17 m3/day for RME-300T, Chuncheon tower-yarder, and FARMI, respectively. Our standardized cost comparison study also showed that the yarding cost was highest at 37,835 won/m3 with FARMI, followed byRME-300T at 25,105 won/m3 for the same work conditions. We found the lowest yarding cost with the Chuncheon tower-yarder at 20,520 won/m3 which was resulted primarily from high yarding productivity at theyarding distance (60 m). Our analysis suggested that a small machine such as FARMI could be a low-costyarding machine option for a cable yarding job with a short yarding distance (40 m or less). The Chuncheontower-yarder is well suited for a mid-range yarding distance job in Korea, ranged between 40 to 140 m. Ifyarding distance were longer than 140 m, the RME-300T tower yarder appears to be most cost-effective.

c-형강 및 ebb & flow 방식에 따른 경제성 분석

강승원(Seung Won Kang),박천호(Chun Ho Pak),조용성(Yong Sung Cho) 한국원예학회 2007 원예과학기술지 Vol.25 No.3

Economical efficiency for production of high quality-potted plants was analyzed by types of irrigation system such as conventional fertigation, ebb & flow, and C-channel as subirrigation systems. After cost structure was analyzed, payback period of capital, internal rate return (IRR), and effects of reduced labor cost were estimated. The gross cost of cyclamen-producing farmers using hydroponic systems in automated greenhouses (10a) was about 100 million won. Of the gross cost, installation and operation costs occupied 74% and 25%, respectively. In the C-channel subirrigation system, gross cost was 120 million won approximately. Installation and operation costs occupied 70% and 30%, respectively. Payback period of capital was 4 years for fertigated irrigation and C-channel subirrigation system, whereas it was 5 years for ebb & flow. IRR of ebb & flow and C-channel subirrigation systems was higher than the interest rates of 4.82%, indicating economic efficiency.

Original Articles : Clinical significance of occult hepatitis B virus infection in chronic hepatitis C patients

( Jae Young Jang ),( Soung Won Jeong ),( Sung Ran Cheon1 ),( Sae Hwan Lee1 ),( Sang Gyune Kim ),( Young Koog Cheon ),( Young Seok Kim1 ),( Young Deok Cho1 ),( Hong Soo Kim ),( So Young Jin ),( Yun Soo 대한간학회 2011 Clinical and Molecular Hepatology(대한간학회지) Vol.17 No.3

Background/Aims: We investigated the frequency of occult hepatitis B virus (HBV) infection in anti-hepatitis C virus (HCV)-positive individuals and the effects of occult HBV infection on the severity of liver disease. Methods: Seventy-one hepatitis B virus surface-antigen (HBsAg)-negative patients were divided according to their HBV serological status into groups A (anti-HBc positive, anti-HBs negative; n=18), B (anti-HBc positive, anti-HBs positive; n=34), and C (anti-HBc negative, anti-HBs positive/negative; n=19), and by anti-HCV positivity (anti-HCV positive; n=32 vs. anti-HCV negative; n=39). Liver biopsy samples were taken, and HBV DNA was quantified by real-time PCR. Results: Intrahepatic HBV DNA was detected in 32.4% (23/71) of the entire cohort, and HBV DNA levels were invariably low in the different groups. Occult HBV infection was detected more frequently in the anti-HBc-positive patients. Intrahepatic HBV DNA was detected in 28.1% (9/32) of the anti-HCV-positive and 35.9% (14/39) of the anti-HCV-negative subjects. The HCV genotype did not affect the detection rate of intrahepatic HBV DNA. In anti-HCV-positive cases, occult HBV infection did not affect liver disease severity. Conclusions: Low levels of intrahepatic HBV DNA were detected frequently in both HBsAg-negative and anti-HCV-positive cases. However, the frequency of occult HBV infection was not affected by the presence of hepatitis C, and occult HBV infection did not have a significant effect on the disease severity of hepatitis C. (Korean J Hepatol 2011;17:206-212)

LC, Acute : O-061 ; Mode of cirrhosis related complication in Korean patients with liver cirrhosis -A prospective multicenter cohort study

( Hyun Young Woo ),( Jeong Won Jang ),( Sang Gyune Kim ),( Chang Hyeong Lee ),( Tae Yeob Kim ),( Won Young Tak ),( Sung Kyu Choi ),( Mong Cho1 ),( Jong Young Choi ) 대한간학회 2012 춘·추계 학술대회 (KASL) Vol.2012 No.-

Background: Cirrhosis-related complications are indications for transplantation. However, the mode of complication has not been evaluated so far. To better address this issue, we investigated the mode of cirrhosis related complication and impact of these complications on survival in prospective, multicenter, inception cohort study of subjects with liver cirrhosis presenting with the first onset of decompensated complication. Methods: In this observational study, 1515 patients with the confirmed onset time of the first decompensated complication were enrolled. The mortality risk of cirrhosis-related complications, including ascites, portal hypertensive gastrointestinal bleeding (PHGB), spontaneous bacterial peritonitis (SBP), hepatic encephalopathy (HE), hepatorenal syndrome (HRS), was analyzed in these cirrhotic patients. Result: As the first complication, ascites was the most frequent (53.8%), followed PHGB (36.2%), HE (7.6%), SBP (1.7%) and HRS (0.7%). During follow-up (mean 32±47 months), 484 (31.9%) experienced subsequent decompensations and the proportion of subsequent complication was consistently changed; the proportion of HE, SBP, HRS increased as time progressed. The interval between subsequent decompensative events was progressively shortened. The mortality rate according to the first complication was as follows; Ascites =PHGB> HE=SBP>HRS. The mortality rate of patients experienceing subsequent complication was significantly higher than those without subsequent complication. According to the kinds of subsequent complication, survival of HE was also higher than HRS but lower than ascites or PHGB and similar to that of SBP and this difference of survival disappeared after repeated complication. Conclusion: The mortality risk correlated with initial complication and the risk increases as the number of complication episodes is repeated. Patient`s mean age was 56±11.50 years and 72.1% was male. The cause of liver cirrhosis is hepatitis B virus (38.6%), alcohol (35.5%) and hepatitis C virus (8.9%).

폐가축사체의 농업적 재활용을 위한 가축사체 액상부산물의 액비화 조건 구명

서영진 ( Young Jin Seo ),서동철 ( Dong Cheol Seo ),강세원 ( Se Won Kang ),이상규 ( Sang Gyu Lee ),박주왕 ( Ju Wang Park ),최익원 ( Ik Won Choi ),성환후 ( Hwan Hoo Sung ),강석진 ( Seog Jin Kang ),조주식 ( Ju Sik Cho1 ) 한국환경농학회 2013 한국환경농학회지 Vol.32 No.4

BACKGROUND: Globally, concern about emerging infectious diseases of livestock is growing. For the disposal of the animal carcass, it is necessary to recycle the carcass into an agriculturally usable product. The objective of this study was to investigate the composting conditions of liquid by-product obtained from degradation of animal carcass. METHODS AND RESULTS: Optimum conditions of liquid fertilizer were investigated using different microorganisms, pHs, and volumes of microorganisms (Lactobacillus rhamnosus + Pichia deserticola). Based on the results from the optimum conditions, compost maturity and quality of liquid fertilizer were evaluated for 112 days. The compost maturity of liquid fertilizer were higher in the order of LP(Lactobacillus rhamnosus + Pichia deserticola) > BC(Bacillus cereus) > BS (Bacillus subtilis). The optimum condition under different volumes of LP was injection of 0.5 mL/100 mL. The compost maturity under different pHs were higher in the order of pH 7 > 5 ≥ 9 ÷ 11. The liquid by-product at 56 days after composting was completely decomposed. The concentrations of T-N, T-P and K2O in liquid fertilizer at 56 days were 0.94, 0.17 and 3.78%, respectively, and the sum of those concentrations was 4.89%. CONCLUSION(S): Liquid fertilizer of by-product using pig carcass was decomposed with optimum conditions(LP, pH 7, injection of 0.5 mL/100 mL) in 56 days after composting, and was suitable for official standard of commercial fertilizer.

알레르기 환자에서 한방 이외의 대체 요법의 사용 현황에 대한 다기관 조사

이현정 ( Hyun Jung Lee ),이재현 ( Jae Hyun Lee ),이용원 ( Yong Won Lee ),김철우 ( Cheol Woo Kim ),동헌종 ( Hun Jong Dhong ),박해심 ( Hae Sim Park ),조영주 ( Young Joo Cho ),조진희 ( Jin Hee Cho ),조상헌 ( Sang Heon Cho ),편복양 ( 대한내과학회 2011 대한내과학회지 Vol.80 No.1

Background/Aims: The use of unproven complementary/alternative medicine (CAM) to treat allergies is popular in Korea. We conducted a multicenter survey of the current use of CAM other than herbal medication in Korean allergy patients. Methods: This study enrolled 510 adults with allergic diseases, including asthma, allergic rhinitis, atopic dermatitis, and chronic urticaria, from ten hospitals. They underwent a structured questionnaire interview and clinical assessment of the prevalence, motivation, costs, and subjective assessment of CAM. Results: Of the patients, 16.7% used at least one type of CAM to treat their allergic diseases. Common types of CAM were diet (48.6%), aroma therapy (23.8%), massage (14.3%), breathing exercises (7.6%), baths (5.7%), and mind control (5.7%). The therapeutic effects of CAM included improved in patients using mind control (50%), diet (50%), breathing exercises (75%), and baths (33.3%), but worse in patients using aroma therapy (28%), and massage (26.7%). About 36.4% of the patients used CAM more than four times per year, and the average cost per CAM user was 370,000 won/year. The main reason for trying CAM was `hope to improve my constitution`. Conclusions: CAM is used widely for treating allergic diseases in Korea. Detailed knowledge of CAM and patient education are important. Further studies of the clinical efficacy of CAM are needed. (Korean J Med 2011;80:68-77)

권역심뇌혈관질환센터 사업의 비용-편익 분석

김병호 ( Byung Ho Kim ),감신 ( Sin Kam ),배상근 ( Sang Geun Bae ),김건엽 ( Keon-yeop Kim ),이원기 ( Won Kee Lee ),홍남수 ( Nam-soo Hong ),박형근 ( Hyeung-keun Park ),이혜진 ( Heyjean Lee ),조은정 ( Eun-jung Cho ),채성철 ( Shung C 한국보건정보통계학회 2017 보건정보통계학회지 Vol.42 No.1

Objectives: This study was conducted to investigate economic feasibility of operating Regional Cardiocerebrovascular Centers using cost-benefit analysis. Methods: The current study assessed cost and benefit data collected from nine hospitals which were designated as Regional Cardiocerebrovascular Centers between 2008 and 2010. Results: The operation of Regional Cardiocerebrovascular Centers reduced mortality rate and length of stay due to acute myocardial infarction and stroke and also decreased disability occurred after stroke. The total calculated cost of operating nine Regional Cardiocerebrovascular Centers was 19.85-22.30 billion won and the minimum benefit calculated was 23.98 billion won. Applying the maximum cost and the minimum benefit, the net benefit was 1.68 billion won, which is estimated to 190 million won per Regional Cardiocerebrovascular Center. Conclusions: The present study revealed that the operation of Regional Cardiocerebrovascular Centers was economically beneficial. The benefit would be larger if intangible benefit such as the long-term effects to community hospitals and enhancement of quality of life of patients and their families are considered.

자동착유시스템 설치농가의 설치 후 만족도에 관한 실태조사

기광석,김종형,정영훈,김윤호,박성재,김상범,이왕식,이현준,조원모,백광수,김현섭,권응기,김완영,여준모,Ki, Kwang-Seok,Kim, Jong-Hyeong,Jeong, Young-Hun,Kim, Yun-Ho,Park, Sung-Jai,Kim, Sang-Bum,Lee, Wang-Shik,Lee, Hyun-June,Cho, Won-Mo,Baek, Kwang- 한국축산환경학회 2011 축산시설환경학회지 Vol.17 No.1

본 시험은 국내에 도입되기 시작한 AMS에 대하여 설치 동기, 설치 후 우유생산량과우유품질, AMS 설치계기 및 설치 후 만족도, AMS 운영상 애로점 및 건의사항 등을 조사 분석하였다. 설치 계기가 무엇인가에 대한 응답비율은 노동력 부족 44%, 체험목장으로 전환 25%, 소들의 고능력화에 대응 19% 순이었으며 기타 6%였다. AMS 설치농가의 사육경력은 평균 24.9년, 평균 연령은 53.2세로 나타났으며 가족노동력만으로 경영하는 목장이 조사농가의 38%, 고용+자가노동력 형태의 목장이 63%로 나타났다. 목장의 산유능력은 두당 평균 유량은 1일 $30.9{\ell}$, 평균 유지율 3.9%, 세균수는 9.1천개/$m{\ell}$ 수준이었다. 후계자 육성에 대한 질문에 매우 그렇다라고 응답한 비율은 68%였으며, 보통 18%, 아니다와 매우 아니다라고 응답한 비율은 18%로 나타났다. 시스템 운영현황 및 애로사항을 파악하기 위하여 AMS의 프로그램 주운영자에 대한 질문에 본인 44%, 부인 6%, 자녀 또는 후계자사람이 44%, 기타 6%나 되었다. AMS 운영상 가장 어려운 점에 대한 조사결과, 기기 작동 및 복잡한 프로그램 운영이 각각 31%로 가장 많았다. 그 외 기계 에러 및 고장에 대한 애로사항이 25%이였다. 도태원인에 대하여 유방염 28%, 번식장애 20%, 발굽질환 19%, AMS에 부적합한 유두 배열 12%, 분만 후 대사성질병 7%, 노산 등 기타 14%였다. 시스템 설치 후 유지보수 계약 체결유무 및 비용에 대하여 유지보수 계약 56%, 유지 보수 계약 미체결 44%이었다. 유지보수 계약 평균 계약비용은 연간 658만원 정도였다. 시스템 설치 후 항목별 만족도에 대하여 5점 만점에 3.9점이었으며, 노동력 절감 3.7점, 업체의 A/S 3.6점, 산유량 증가 3.2점, 원유의 체세포 수 저감 2.8점이었다. 시스템 설치 시 고려사항 및 건의사항에 대하여 고가의 장비를 효율적으로 사용하기 위하여 젖소의 유방과 유두 배열이 적합하도록 젖소를 선발하는 것, 시스템을 운용할 수 있는 능력, 적합한 환경, 재정적 능력과 부지 확보, 지속적인 관찰 등이 권장되어야 할 것으로 나타났으며, 설치 업체에 대해서는 컨설팅이 체계화될 필요가 가장 높게 나타났으며 이어서 보다 저렴한 설치와 서비스의 체계화를 요구하는 결과를 보였다. The present survey was conducted to provide basic information on automatic milking system (AMS) in relation to purchase motive, milk yield and quality, customer satisfaction, difficulties of operation and customer suggestions, etc. Purchase motives of AMS were insufficient labor (44%), planning of dairy experience farm (25%), better performance of high yield cows (19%) and others (6%), respectively. Average cow performance after using AMS was 30.9l/d for milk yield, 3.9% for milk fat, 9,100/ml for bacterial counts. Sixty-eight percentage of respondents were very positive in response to AMS use for their successors but 18% were negative. The AMS operators were owner (44%), successor (44%), wife (6%) and company worker (6%), respectively. The most difficulty (31%) in using AMS was operating the system and complicated program manual. The rate of response to system error and breakdown was 25%. The reasons for culling cow after using AMS were mastitis (28%), reproduction failure (19%), incorrect teat placement (12%), metabolic disease (7%) and others (14%), respectively. Fifty-six percentages of the respondents made AMS maintenance contract and 44% did not. Average annual cost of the maintenance contract was 6,580,000 won. Average score for AMS satisfaction measurement (1 to 5 range) was 3.2 with decrease of labor cost 3.7, company A/S 3.6, increase of milk yield 3.2 and decrease of somatic cell count 2.8, respectively. Suggestions for the higher efficiency in using AMS were selecting cows with correct udder shape and teat placement, proper environment, capital and land, and attitude for continuous observation. Systematic consulting was highly required for AMS companies followed by low cost for AMS setup and systematization of A/S.