Measurements of surgeons’ exposure to ionizing radiation dose: comparison of conventional and mini C-arm fluoroscopy

Sung, K. H.,Min, E.,Chung, C. Y.,Jo, B. C.,Park, M. S.,Lee, K. SAGE Publications 2016 The journal of hand surgery. journal of the Britis Vol.41 No.3

<P>This study was performed to measure the equivalent scattered radiation dose delivered to susceptible organs while simulating orthopaedic surgery using conventional and mini C-arm fluoroscopy. In addition, shielding effects on the thyroid, thymus, and gonad, and the direct exposure delivered to the patient's hands were also compared. A conventional and mini C-arms were installed in an operating room, and a hand and an operator phantom were used to simulate a patient's hand and a surgeon. Photoluminescence dosimeters were used to measure the equivalent dose by scattered radiation arriving at the thyroid, thymus, and gonad on a whole-body phantom in the position of the surgeon. Equivalent scattered radiation doses were measured in four groups: (1) unshielded conventional C-arm group; (2) unshielded mini C-arm group; (3) lead-shielded conventional C-arm group; and (4) lead-shielded mini C-arm group. Equivalent scattered radiation doses to the unshielded group were significantly lower in the mini C-arm group than those in the conventional C-arm group for all organs. The gonad in the lead-shielded conventional C-arm group showed the highest equivalent dose among operator-susceptible organs, and radiation dose was reduced by approximately 96% compared with that in the unshielded group. Scattered radiation was not detected in any susceptible organ in the lead-shielded mini C-arm group. The direct radiation dose to the hand phantom measured from the mini C-arm was significantly lower than that measured from the conventional C-arm. The results show that the equivalent scattered radiation dose to the surgeon's susceptible organs and the direct radiation dose to a patient's hand can be decreased significantly by using a mini C-arm rather than a conventional C-arm. However, protective lead garments, such as a thyroid shield and apron, should be applied to minimize radiation exposure to susceptible organs, even during use of mini C-arm fluoroscopy.</P>

Effects of DME mixing on number density and size properties of soot particles in counterflow non-premixed ethylene flames

최재혁,B. C. Choi,S. M. Lee,S. H. CHUNG,K. S. Jung,W. L. Jeong,S. K. Choi,S. K. Park 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.5

In order to investigate the effect of DME mixing on the number density and size of soot particles, DME was mixed in a counter flownon-premixed ethylene flame with mixture ratios of 5%, 14% and 30%. A laser extinction/scattering technique has been adopted tomeasure the volume fraction, number density, and mean size of soot particles. The experimental results showed that the highest soot concentrationswere observed for flames with mixture ratios of 5% and 14%; however, for a mixture ratio of 30% the soot concentrationdecreased. Numerical results showed that the concentrations of propargyl radicals (C3H3) at the 5% and 14% ratios were higher thanthose measured in the ethylene-based flame, and the production of benzene (C6H6) in the 5% and 14% DME mixture flames was alsoincreased. This indicates the crucial role of propargyl in benzene ring formation. These reactions generally become stronger with increasedDME mixing, except for A1 + H2 → A1 + H (-R554) and n-C4H5 + C2H2 → A1 + H (R542). Therefore, it is indicated that addingDME to ethylene flames promotes benzene ring formation. Note that although the maximum C6H6 concentration is largest in the 30%DME mixing flame, the soot volume fraction is smaller than those for the 5% and 14% mixture ratios. This is because the local C6H6concentration decreases in the relatively low temperature region in the fuel side where soot growth occurs.

2, 4-Thiazolidindion Induced Plasticity of Myoblast (C2C12) and Satellite Cells (Porcine) - A Comparative Study

Singh, N.K.,Chae, H.S.,Hwang, I.H.,Yoo, Y.M.,Ahn, C.N.,Lee, H.J.,Park, H.J.,Chung, H.Y. Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.7

This study was conducted to determine the difference between satellite cells (porcine) and myoblasts (C2C12) in their differentiation under the influence of 2, 4-thiazolidindion. C2C12 myoblast cells and porcine satellite cells (isolated from 10 d old $Landrace{\times}Duroc$ piglets) were grown to absolute confluency. Post confluent cells (day 0) were further exposed to adipogenic induction medium along with 2, 4-thiazolidindion ($8{\mu}M$) for 2 d. Thereafter, cells were exposed to 2, 4-thiazolidindion alone every 2 d till day 10 and analysed. The control was cultured in differentiation medium without any treatment. Increased (p<0.05) expression of transcriptional factors i.e. C/EBP-${\alpha}$ and PPAR-${\gamma}$ and transition of cells to adipocyte morphology was noticed from 2 d and 4 d onwards in satellite cells (Porcine) and myoblasts (C2C12) respectively. Myogenesis was observed to be suppressed completely in case of satellite cells compared to myoblasts in response to 2, 4-thiazolidindion. Pax-7 (transcriptional factor) appeared as a sole entity to satellite cells only, as it was not identified in case of myoblasts. Although both the cells were converting to adipoblasts, the degree of their conversion was different in response to 2, 4-thiazolidindion. Therefore, the hypothesis that satellite cells contribute various domains to the growing myoblasts appeared obscured and found to be dependent on the proliferative energy/or degree of fusion. However, it revealed satellite cells as currency to myoblasts/muscle.

농후사료 급여수준이 비거세 한우의 증체와 부위별 지방조직의 지방산 조성에 미치는 효과

송만강,김내수,정정수,최양일,원유석,정재경,최성호 ( M . K . Song,N . S . Kim,C . S . Chung,Y . I . Choi,Y . S . Won,J . K . Chung,S . H . Choi ) 한국축산학회 1998 한국축산학회지 Vol.40 No.5

The study was conducted with 63 Hanwoo bull calves of 193 days old for 19 months(up to 26 month of age) to examine the effect of feeding level of concentrate on the body weight gain, feed requirements and fatty acid composition of adipose tissues of various locations(subcutaneous, abdominal, kidney, intermuscular and intramuscular fats). The calves were allotted into 3 treatments according to the feeding level of concentrate(85, 100 and 115%), and fed concentrates of Grower(7∼10 month of age), Finisher I(11∼16 month of age), Finisher II (17∼20 month of age) and Finisher III(21∼26 month of age). The feeding levels of concentrates for the cattle of 85% and 115% were decreased or increased by 15%, respectively, up to 15 month of age based on the similar body weight to the cattle of 100%. The feeding levels of the concentrates for the cattle of 85% and 100% were continuously increased for the next 2 months, to make same levels as for the cattle of I15%, thereafter amount of concentrate were continuously increased based on the rate of body gain for all the cattle. The cattle were fed in a individual feeding system through the experimental period. The cattle were slaughtered at the ages of 6, 14, 18 and 24 month and adipose tissues were collected to analyze long chain fatty acids. Results observed from the study were summarized as follows Overall mean dry matter intake and body gain per day and feed requirements of Hanwoo bulls during the 19 months of feeding from 193 day old calves were 6.69㎏, 0.95㎏ and 7.06, respectively. Body gain of the Hanwoo bulls during experimental period was greatly affected by the feeding level of concentrate, but feed requirement was improved up to 20 month of age with the decreased feeding level of concentrate. Fatty acids of C_(16:0) C_(18:0) and C_(18:1) in the adipose tissues at various locations of Hanwoo bulls were dominated. The feeding level of concentrate did not affect the fatty acid composition except for C_(16:1) and C_(18:1) in subcutaneous fat, and C_(18:1) and C_(18:2) in intramuscular fat of the cattle that were fed at the level of 85% at the age of 14 month(P$lt;.05). No differences were observed in fatty acid composition of adipose tissues of each location for the cattle of 18 and 24 month of age among treatments. There were tendencies of greater C_(16:1) and C_(18:1) in subcutaneous and intramuscular fats while higher C_(18:0) in abdominal fat. There were also trends of greater unsaturated fatty acid compositions in subcutaneous and intramuscular fats and higher saturated fatty acids in abdominal, kidney and intermuscular fats. Percent C_(18:0) tended to be decreased while C_(16:1) C_(18:1) and C_(18:2) increased with the age of Hanwoo bulls.

H-Y 에 대한 단일클론 항체의 생산 및 그 이용에 관한 연구 1 . H-Y 에 대한 단일클론항체의 생산

심호섭(H . S . Shim),김재화(J . H . Kim),이병철(B . C . Lee),김종배(J . B . Kim),박홍양(H . Y . Park),정길생(K . S . Chung) 한국축산학회 1988 한국축산학회지 Vol.30 No.7

Testis supernatant, a source of H-Y, obtained from BALB/c mice was used to immunize females of same strain. B lymphocytes of mouse producing antibodies to H-Y were fused with SP2/0-Ag 14 myeloma cells and distributed to 384 wells of 96-well microtiter plates. Eighty hybridoma colonies were formed, resulting in 20.8 percent of fusion efficiency. Three strong positive wells from hybridoma colonies were selected for cloning by ELISA and two of them were also found to be positive by indirect immunofluorescence test. Twelve wells of ELISA-positive were selected after cloning and 2D45D4 clones from them were confirmed to produce monoclonal antibodies to H-Y by indirect immunofluorescence test.

CIE L 기준에 의한 PSE 육과 정상육의 육질 및 도체특성에 관한 연구

정일병,이무하,김태헌,이영창,김동훈,김일석,채현석,김웅배 한국축산학회 1998 한국축산학회지 Vol.40 No.6

Two hundreds and twenty two pork carcasses from a commercial breed were investigated for meat quality and carcass traits of PSE and normal pork classified by CIE L value. pH and conductances were taken on 1(pH₁, C₁), 3(pH₃, C₃), 6(pH_6, C_6) and 24 hr postmortem(pHu, C_u). Significant differences between PSE and normal pork were observed in pH₁, pH_u (p $lt; 0.001) and pH₃(p $lt; 0.05). But, no significant difference was found in pH_6. Although, there was no significant difference in C₁, significant differences are found in C₃(p $lt; 0.05), C_6 (p $lt; 0.01) and C_u(p$lt;0.001). The water holding capacity(WHC) were significantly lower(p$lt;0.01) in the PSE compared to the normal pork. The cooking loss were significantly higher(p $lt; 0.05) in the PSE compared to the normal pork. The CIE L value was highly related with NPPC color scale(R²=0.77), moderately related with pH_u (R²=0.45), C_u(R²=0.57), WHC(R²=0.49), cooking loss(R²=0.45) and juiciness(R²=0.43), and poorly related with pH₃(R²=0.27), pH_6(R²=0.27) and conductances(R²=0.05-0.15). Consequently, the results suggest that pork quality classification by CIE L value expresses obvious differences in most of important pork quality parameters like pH₁, pH_u, C_u visual color and WHC.

C language를 위한 Concurrent Programming 환경의 개발

윤용익(Y I Yoon),조주현(J H Cho),정영조(Y C Chung),강석열(S Y. Kang) 한국정보과학회 1988 한국정보과학회 학술발표논문집 Vol.15 No.1

Multiprocessor system이 널리 보급되고 사용됨에 따라 concurrent programming은 더욱 더 중요한 feature가 되어가고 있다. 기존의 C 언어는 concurrent programming을 위한 feature들을 가지고 있지 못하나, 본 논문에서는 concurrent processing이 가능한 Concurrent-C 언어를 설계, 구현하였다. Concurrent feature들을 첨가하는 방법으로는 여러 종류의 runtime library routine들을 제공하여 C program 내에서 이 routine들을 call하는 방식을 사용하였다. Concurrent-C는 UNIX 환경하에서 구현되었으며, 실제로 C compiler를 제공하는 어떠한 OS 상에서도 host machine의 종류에 관계없이 구현될 수 있다.

IA-PID 제어기를 이용한 교류-직류시스템의 동태안정도에 관한 연구

정형환,정현화,왕용필,박희철 동아대학교 생산기술연구소 2001 生産技術硏究所硏究論文集 Vol.6 No.2

In this paper, a method for optimal design of PID controller using the immune algorithm(IA) has been proposed to improve the stability of A.C.-D.C. power system. To design optimal PID controller, formulation of A.C.-D.C. system equation, selection of stability analysis model, formulation immune algorithm and application model of optimal PID controller are proposed in order of the paper. In case of various disturbance, computer simulations have been performed and the proposed IA-PID controller has been compared with base controller which is conventional control technique for dynamics. From simulation results, it is demonstrated that proposed IA-PID controller has good dynamic responses about the disturbance of power system and reliability as compared with the base control.

Catalytic properties of microporous zeolites in the synthesis of octyl glucoside from D-glucose with 1-octanol by single-step direct glucosidation

Chung, K.H.,Lee, S.J.,Lee, H.,Kim, H.,Park, Y.K.,Kim, B.H.,Jung, S.C. Elsevier 2016 Microporous and mesoporous materials Vol.233 No.-

<P>Catalytic properties of various microporous zeolites consisted of different acidic properties and pore topologies were studied in the synthesis of octyl glucoside from D-glucose with 1-octanol by single-step direct glucosidation. The influences of acidic properties and pore topologies of the zeolite catalysts were evaluated relating to the conversion of glucose and selectivities of octyl glucosides. The octyl glucosides could be synthesized conveniently by the single-step direct glucosidation through aging of reactants without further pre-treatment or additional supply of reactant. The reusability of the zeolite catalyst was evaluated to the used zeolite. The high conversion of D-glucose was obtained on H+ ion exchanged FAU (H-FAU) zeolite which has a mild acid strength. The conversion and yield were improved with increasing of acid site amount of the zeolite catalysts. H-FAU zeolite catalysts exhibited high octyl glucopyranoside selectivity owing to relatively a large pore cavity and a high concentration of mild acid sites. The selectivities of the octyl glucoside isomers were mainly depended on the differences of pore structure and concentration of acid sites of the zeolite catalysts. The zeolite used in the reaction was able to reuse through the regeneration process. (C) 2016 Elsevier Inc. All rights reserved.</P>

H-Y 항체에 의한 토끼배의 성조절에 관한 연구 1 . 배의 발달과 형광 발현에 의한 자 웅 수정란의 분리

이창규(C . K . Lee),정구민(K . M . Chung),김수헌(S . H . Kim),임경순(K . S . Im) 한국축산학회 1990 한국축산학회지 Vol.32 No.7

Antisera to histocompatibility (H-Y) antigen were used to immunologically presume the sex of rabbit embryos. H-Y antisera were prepared in inbred SD female rat by repeated immunization of spleen cells from males of same strain. The titre of H-Y antibody in antiserum was examined by mouse sperm cytotoxicity and biological tests. Experiments applied delaying ability of development of embryos in H-Y antiserum and binding ability of FITC labelled second antibody. After culture, embryos were observed their morphological characteristics under phase contrast microscope and detected fluorescence on embryos under fluorescence microscope. After detection of fluorescence, embryos were transfered to normal medium and observed their morphological characteristics. 1. When rabbit morula were treated with H-Y antiserum only, the rate of developed and delayed embryos was 47.2 and 52.8% respectively, and the rate of non-fluorescing and fluorescing embryos was 51.4 and 48.6%, respectively. 2. When rabbit morula were cultured in H-Y antiserum followed by complement, the rate of non-fluorescing and fluorescing embryos was 53.6 and 46.4%. respectively. 3. After detection of fluorescence, the embryos were cultured in normal medium. When embryos were treated with H-Y antiserum only, the rate of arrested and developed embryos was 20.8 and 79.2% respectively. However, when embryos were treated with H-Y antiserum followed by complement, the rate of arrested and developed embryos was 42.9 and 57.1% respectively.