Skin entrance dose for digital and film radiography in Korean dental schools

Cho, Eun-Sang,Choi, Kun-Ho,Kim, Min-Gyu,Lim, Hoi-Jeong,Yoon, Suk-Ja,,Kang, Byung-Cheol 대한구강악안면방사선학회 2005 Imaging Science in Dentistry Vol.35 No.4

Purpose : This study was aimed to compare skin entrance dose of digital radiography with that of film radiography and to show the dose reduction achievement with digital systems at 11 dental schools in Korea. Materials and Methods : Forty six intraoral radiographic systems in 11 dental schools were included in this study. Digital sensors were used in 33 systems and film was used in 13 systems. Researchers and the volunteer visited 11 dental schools in Korea. Researchers asked the radiologic technician (s) at each school to set the exposure parameters and aiming the x-ray tube for the periapical view of the mandibular molar of the volunteer. The skin entrance doses were measured at the same exposure parameters and distance by the technician for each system with a dosimeter (Multi-O-Meter : Unfors instruments, Billdal, Sweden). Results : The median dose was 491.2 μGy for digital radiography and 1,205.0 μGy for film radiography. The skin entrance dose digital radiography was significantly lower than that of film radiography (p<0.05). Conclusion : Fifty-nine percent skin entrance dose reduction with digital periapical radiography was achieved over the film radiography in Korean dental schools.

연구보문 : 식물환경 ; 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

가축사체 액상부산물을 이용하여 액비의 최적조건(미생물, pH, 미생물 주입량)을 조사하였고, 이들 최적 조건하에서 112일간 부숙하여 액비의 품질을 평가하였다. 가축사체 액상 부산물 액비 부숙시 최적 LP 미생물의 주입량은 0.5 mL/100mL이었으며, pH는 7 조건에서 각각 50점으로 완숙판정을 받았다. 최적조건하에서 112일 동안 부숙시킨 액비의 부숙도 는 부숙 후 28일에 50점을 받아 완숙판정을 받았으며, 부숙기 간이 길어짐에 따라 부숙 56일에는 온도가 60℃를 넘어 최고 점인 55점을 받았고, 이후 온도가 조금씩 낮아져 부숙 후 112 일에는 실온조건에 이르렀다. 완숙된 가축사체 액상부산물 액 비의 품질을 평가해본 결과, 최적조건하에서 부숙시킨 액비의 경우에는 T-N, P2O5 및 K2O의 함량이 28일에 가장 높았으며, 시간이 경과함에 따라 약간 감소하는 경향이었다. 또한, 유해성분(As, Cd, Cu, Cr, Hg, Ni, Pb 및 Zn)의 함량은 28일, 56일 및 112일 부숙시킨 액비에서 모두 비료공정규격 기 준치에 적합하였다. 이상의 결과를 미루어 볼 때 가축사체 액상부산물을 농업적 재활용을 위한 액비화 조건은 pH 7조건 에서 LP 미생물을 0.5 mL/100 mL 주입한 경우이다. 하지 만 본 연구에서 비교된 가축분뇨 발효액은 공시재료(가축사체)가 상이하여 향후 가축사체를 이용한 액비의 부숙도 기준이 개선되어야 할 것으로 판단된다. 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.

Test Observations of 14m Radio Telescope(I)

Cho, Se-Hyung,Auh, Byung-Ryul,Jung, Jae-Hoon,Lee, Chang-Hoon,Kim, Hyun-Goo,Park, Yong-Sun,Roh, Duk-Gyoo,Yim, In-Sung,Kim, Bong-Gyu,Kim, Tu-Hwan 한국천문학회 1987 天文學會報 Vol.12 No.-

High Prevalence of the China 1 Strain of Epstein-Barr Virus in Korea as Determined by Sequence Polymorphisms in the Carboxy-Terminal Tail of LMP1

Cho, Sung-Gyu,Lee, Won-Keun The Microbiological Society of Korea 2003 The journal of microbiology Vol.41 No.2

The Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMPI) exhibits considerable sequence heterogeneity among EBV isolates. Seven distinct EBV strains have been defined based on sequence polymorphisms in the LMPI gene, which are designated China 1, China 2, China 3, Alaskan, Mediterranean, NC, and the B95-8 strains. In this study, we analyzed a 30-bp deletion and sequence variations in the carboxy-terminal region of the LMPl gene in 12 EBV isolates from spontaneous lym-phoblastoid cell lines derived from individuals with non-EBV associated cancers in Korea. Eleven of the 12 isolates showed a 30-bp deletion spanning LMPI amino acids 342 to 353, suggesting a high prevalence of the LMPI 30-bp deletion variant among EBV isolates in Korea. In addition, all 12 isolates had a 15-bp common deletion in the 33-bp repeat region and multiple base-pair changes relative to the prototype B95-8 EBV strain along with variations in the number of the 33-bp repeats. The bp changes at positions 168746, 168694, 168687, 168395, 168357, 168355, 168631, 168320, 168308, 168295, and 168225 were highly conserved among the isolates. Comparative analysis of sequence change patterns in the LMPI carboxy-terminal coding region identified nine 30-bp deletion variants as China 1, two deletion variants as a possible interstrain between the Alaskan and China 1 strains, and a single undeleted variant as a possible variant of the Alaskan strain. These results suggest the predominance of the China 1 EBV strain in the Korean population.

Pulsed Plasma Process for the Flue Gas Removal from the Industrial Incinerator using Peak 200-kV, 10 kA Pulse Modulator

Sung-Duck Jang,Dong-Jun Koh,Jong-Seok Oh,Moo-Hyun Cho,Yoon-Gyu Son 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.44 No.52

The electrical discharge process, especially the pulsed plasma discharge process can be applied to the removal of pollutant gases from industrial plants such as power generation plants and incinerators. Up to now, most of the study has been performed in a laboratory scale with short-term tests due to the lack of a reliable pulse modulator with a high average power. The pulsed corona discharge method shows encouraging results for the removal of NOx and SO2 gases based on smallscale experiments. A 120-kW high average power modulator for industrial applications of the pulsed corona process to remove ue gas has been designed and manufactured. It is one of the largest scale modulator systems in the world for treating NOx and SO2 simultaneously. Its design specications are as follows: an average power of 120 kW, a peak voltage of 200 kV with a full width at half maximum (FWHM) of 500 nsec, a peak current of 10 kA, and a pulse repetition rate of 300 Hz. It is required to have long lifetime and high reliability for commercial plant application because the downtime for maintenance aects plant availability. A high-power, fast semiconductor switch, a magnetic-pulse-compression (MPC) switch, and a fast-pulse transformer are essential components to meet these requirements. The 120-kW high average power modulator has been installed and tested at an industrial incinerator plant with a gas ow of 50,000 Nm3/Hr. This modulator was operated with pulses of up to 150 kV with 500-nsec (FWHM) pulse widths at a 240-Hz repetition rate in a plasma reactor. This paper presents the design details and operational test results. Especially, the dynamic operating characteristics of the MPC modulator combined with the non-thermal plasma reactor were measured, and the SO2 and NOx removal characteristics were analyzed.

Parameter Identification and Control of Nonlinear System Using Neural Network

Gyu Sang Cho,Chae Tak Lim 대한전자공학회 1996 ITC-CSCC :International Technical Conference on Ci Vol.- No.-

Improvement in Performance of SBT-Based Ferroelectric Memory by Blocking Impurities from Capacitor-Level Dielectric

Sang-Hyun Oh,Eui-Seong Hwang,Eun-Seok Choi,Gyu-Dong Park,Jin-Gu Kim,Jin-Yong Seong,Jun-Hee Cho,Keun-Do Ban,Keun-Hwan Noh,Nam-Kyeong Kim,Seaung-Suk Lee,Seok-Won Lee,Seung-Jin Yeom,Soon-Yong Kweon,Suk-K 한국물리학회 2003 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.42 No.IV

We have investigated the ferroelectric properties of integrated Pt/SrBi2Ta2O9 (SBT)/Pt capacitors with capacitor-level dielectric of boron phosphosilicate glass (BPSG). A signicant reduction of remanent polarization (P-P^) was observed in the SBT capacitor as covered with BPSG lm and the polarization decay depended strongly on top electorde size. Detailed analyses showed the degradation resulted from bismuth loss in the surface region of SBT, which is closely related with the impurites diused from BPSG into SBT layer. The degradation of Pt/SBT/Pt ferroelectric capacitor was successfully prevented by inserting SiO2 layer as a impurity blocking layer between the SBT and the BPSG. Thereby device performances of SBT-based ferroelectric memory were also considerably improved.

Risk Management for Hydrogen/natural Gas Pipeline Transportation

Sang-Gyu Cho(조상규),Dong Yeol Lee(이동열),Jeong-Hoon Sa(사정훈) 한국신재생에너지학회 2022 한국신재생에너지학회 학술대회논문집 Vol.2022 No.4

Isolation and Identification of Lactic Acid Bacteria Isolated from a Traditional Jeotgal Product in Korea

Cho, Gyu-Sung,Do, Hyung-Ki The Korean Society of Oceanography 2006 Ocean science journal Vol.41 No.2

Seventeen lactic acid bacterial strains (LAB) were isolated using MRS agar medium from Jeotgal, a Korean fermented food, purchased at the Jukdo market of Pohang. To identify the strains isolated, they were tested by examining their cell morphologies, gram-staining, catalase activity, arginine hydrolase activity, D-L lactate form and carbohydrate fermentation. According to the phenotypic characteristics, three strains were tentatively identified as Lactobacillus spp., ten were Enterococcus spp. (or Streptococcus spp., or Pediococcus spp.) and the rest were Leuconostoc spp. (or Weissella spp.). Five strains among 17 were chosen by preliminary bacteriocin activity test. Four bacterial strains which inhibited both indicator microorganisms were identified by 16S rRNA sequencing. The results are as follows; Leuconostoc mesenteroides (HK 4), Leuconostoc mesenteroides (HK 5), Leuconostoc mesenteroides(HK 11), Streptococcus salivarius(HK 8). In order to check LAB which are showing a high survival rate in gut, we investigated three strains inhibiting both indicator microorganisms in artificial gastric acid and bile juice -all except HK8. The three strains mentioned above grew in extreme low acid conditions.

Retroperitoneal Mucinous Cystadenoma

Gyu Yeol Kim(김규열),Dae Hwa Choi(최대화),Young Chul Lim(임영철),Byung Kyun Ko(고병균),Sang June Park(박상준),Yang Won Nah(나양원),Hong Rae Cho(조홍래),Chang Woo Nam(남창우) 대한외과학회 2008 Annals of Surgical Treatment and Research(ASRT) Vol.74 No.1

일차성 후복막 점액성 낭선종은 흔치 않은 종양으로 여성에게만 발생하며, 수술 전에 정확한 진단을 하기 매우 어렵다. 하지만, 이러한 낭성 종양의 낭액에서의 증가된 암태아성항원의 수치가 일차성 후복막 점액성 낭선종의 유용한 진단 지표가 될 수 도 있다. 완전 절제가 이 종양의 적절한 치료이다. 또한, 수술 중 복강 내 타 장기들을 누르거나 할 필요가 없으며, 소장 및 대장이 손상될 위험을 줄일 수 있다는 측면에서 후복막 접근이 복강 내 접근 보다 유용한 방법일 수 있다. 저자들은 후복막 접근을 통해 성공적으로 절제한 일차성 후복막 점액성 낭선종의 경험을 보고한다. We present a case of a primary retroperitoneal mucinous cystadenoma, which is a relatively rare tumor found exclusively in women. This tumor is difficult to correctly diagnose preoperatively. Although there is little published information regarding the CEA levels in the cystic fluid of cystic tumors arising in the retroperitoneum, a high CEA level in the cystic fluid is a useful diagnostic marker for a primary retroperitoneal mucinous tumor. The appropriate management of retroperitoneal mucinous cystadenomas is the total removal of the cyst. The retroperitoneal approach for retroperitoneal cystic tumors is useful, has a lower risk of traumatizing the bowel than the intra-abdominal approach, and does not require compression of the other organs. We report the successful resection of a retroperitoneal mucinous cystadenoma through the retroperitoneal approach.