고유동 콘크리트용 분리저감형 유동화제의 개발에 관한 기초적 연구

전충근,손성운,김성수,한천구 청주대학교 산업과학연구소 2001 産業科學硏究 Vol.19 No.1

The purpose of this paper is to develope segregation reducing type superplasticizer for high fluidity concrete and to manufacture high fluidity concrete by applying developed segregation reducing type superplasticizer using flowing concrete method in the rane go of 45% of W/C. According to test results, as dosage of superplasticizer increases, it shows that fluidity and bleeding increase, while air content and segregation resistance decrease. It also shows that adding of viscosity agent reduce bleeding and improve segregation resistance. Dosage of AE agent recovers loss of air contents during flowing Procedure. Combination of proper contents of superplasticizer, viscosity agent and AE agent make possible to develope segregation reducing type soperplasticizer According to experimental results, optimal proportion of superplasticizer, viscosity agent and AE agent show to be 1'0.60'0.027 Compressive strength of high fluidity concrete is simihar to comprssive strength of base concrete

골격성 Ⅲ급 부정교합자에서 전진이부성형술을 동반한 하악 후퇴술 후 연조직 외형의 변화

김근령,김성식,손우성,박수병 대한치과교정학회 2008 대한치과교정학회지 Vol.38 No.2

본 연구는 전진이부성형술을 동반한 하악지 시상분할골절단술을 시행한 하악 전돌증을 가진 환자에서 하안면부, 특히 이부의 경조직과 연조직의 변화를 예측하는 데 있어서, 전후관계와 수직적 계측치를 통하여, 경조직의 변화에 따른 연조직의 상대적 변화량에 대해 비교, 분석하여 한국인의 골격성 III급 부정교합자의 악교정 수술시 전진이부성형술이 연조직 외형에 미치는 영향을 알아보고자 시행하였다. 교정치료와 악교정수술을 시행한 골격성 III급 부정교합자 40명을 전진이부성형술을 시행하지 않고 하악지 시상분할골절단술만 시행한 환자 20명(BSSO group, 남자 10명, 여자 10명)과 하악지 시상분할골절단술과 동시에 전진이부성형술을 시행한 환자 20명(Genio group, 남자 10명, 여자 10명)으로 분류하여 수술 직전(T1)과 수술 직후(T2), 수술 최소 6개월 후(T3)의 측모 두부 방사선계측사진을 채득하여 계측 항목의 변화량을 분석하였다. BSSO군에서는 수술 후 경조직 B점, Pogonion, Menton에 대하여 연조직 B점, Pogonion, Menton이 각각 수평적으로 0.997, 0.965, 1.022의 변화율을 보였으며, Genio군에서는 각각 0.824, 0.602, 0.887의 수평적 변화율을 보여서, Genio군에서 연조직 B점, 연조직 Pogonion의 연조직 두께의 감소량이 더 크게 나타났다. 경조직 Pogonion(Pg)의 악교정수술 전과 후의 수평적 변화에 따른 하순의 하방점(Li), 연조직 B점(B')의 변화간의 상관관계계수는 BSSO군에서는 각각 0.833, 0.922인 반면에, Genio군에서는 각각 0.775, 0.799로 BSSO군에 비해서 상관관계가 다소 작은 것으로 나타났다. 이상의 결과에서 하악지 시상분할골절단술을 시행하는 환자에서 전진이부성형술을 동반할 경우에는 골격의 변화에 대해서 연조직의 두께 변화가 다소 적게 나타나므로 수술 시에 이를 고려하여 전진이부성형술을 시행하여야 할 것이다. Purpose: The purpose of this study was to assess the hard and soft tissue changes associated with mandibular bilateral sagittal split osteotomy and genioplasty. Methods: This is a retrospective study of 40 patients who underwent either bilateral sagittal split osteotomy for mandibular setback (BSSO group, n = 20) or in combination with advancement genioplasty (Genio group, n = 20). Lateral radiographs, were taken before and immediately after surgery, and at least 6 months after surgery. Results: Comparing hard and soft tissue changes between the BSSO group and Genio group, there were significant differences in the lower incisor, soft tissue B point (B'), and soft tissue Pogonion (Pg') (P < 0.5). The mean ratio of hard and soft tissue changes for B/B', Pg/Pg', and Menton/soft tissue Menton after surgery in the BSSO group was 0.997, 0.965, and 1.022 respectively, and 0.824, 0.602, and 0.887 respectively in the genio group. Significant differences were found between the two groups. There were significant differences in lip thickness (B-B', Pg-Pg') in the Genioplasty group between pre and postsurgery, but not in the BSSO group. Pogonion to Labrale inferior and B' had a correlation coefficient of 0.833, 0.922, respectively for the BSSO group, and 0.775, 0.799 for the Genio group. Conclusions: The results indicate that there is a significant difference between bilateral sagittal split osteotomy with or without genioplasty in the lower facial esthetics values. The combination of mandibular setback and genioplasty had a smaller change in soft tissue thickness of the symphysis area after surgery than that of mandibular setback only.

FDM 3D Printing of Environmental Friendly and High Strength Bio-based PC Filaments for Baby Toys

( Seong Je Park ),( Ji Eun Lee ),( Jean Ho Park ),( Min-young Lyu ),( Keun Park ),( Myung Sool Koo ),( Sun Chul Jin ),( Ki Yong Kim ),( Yong Son ) 한국고무학회 2017 엘라스토머 및 콤포지트 Vol.52 No.2

Due to the depletion of fossil oil and the increasing oil price, bio-plastic is currently topical. Bio-based plastics are synthesized from plant resources, unlike conventional petroleum-based counterparts. Therefore, the former minimizes global warming and reduces carbon dioxide emission. Fossil polycarbonate (PC)has good mechanical and optical properties, but its synthesis requires bisphenol-A and phosgene gas, which are toxic to humans. To address these problems, the fused deposition 3D printing process (hereafter, FDM) is studied using environmentally-friendly and high-strength bio-based PC. A comparisonof the environmental impact and tensile strength of fossil PC versus bio-based PC is presented herein, demonstrating that bio-based PC is more environmentally-friendly with higher tensile strength than fossil PC. The advantages of bio-based PC are applied in the FDM process for the fabrication of environmentally-friendly baby toys.

Increase of Production Ratio of Pre-selected Superior Dairy Female Offspring by Combination of OPU derived Oocytes and X-bearing Semen

Seong-Su Kim,Byung-Hyun Choi,Kyeong-Lim Lee,Jong-In Jin,Tae-Kwang Suh,Cheol-Ho Son,Chan-Ho Park,Seung-Oh Shin,Kwang-Jin Han,Hyun-Tae Lim,Kyu-Woan Cho,Il-Keun Kong 한국수정란이식학회 2015 한국동물생명공학회지 Vol.30 No.2

This study was designed to evaluate the possibility of increase through dairy female offspring’s ratio by transfer of pre-selected transferrable blastocyst that was produced by pre-selected X-bearing semen with OPU derived oocytes. Elite dairy female cow is demanded strongly compared with male, the so called, farmer wants to produce only an elite female dairy offspring as a candidate female dairy cow for producing milk. In our study, we selected 2 elite dairy bull semen from National Agricultural Cooperative Federation to pre-select X-bearing semen and 5 elite dairy female cows as donor for collecting of OPU derived oocytes. OPU derived embryo production system was carried out an aspiration of immature oocytes from 5 donor cows 2 times per week, total 200 times for 2 to 7 months by an ultrasonographic guided follicular aspiration system and then produced in vitro-produced blastocysts by in vitro maturation, fertilization and culture. Dairy donor semen selected H-319, 320 bull in National Agricultural Cooperative federation was sorted X-bearing semen by flow-cytometer and frozen for using IVF with OPU derived oocytes. Donor cows were selected 5 elite dairy cows from Gyeongju Dairy Cow Community and then disease tests such as 4 kinds of disease before selecting was checked. Oocyte proportion of grade 1 to 3 from total collected oocytes was significantly lower in donor A and B than those in donor C, D and E (82.16 and 70.03% vs. 90.0, 91.78 and 93.57%), respectively (p<0.05). However, number of oocytes per session in donor A, C and E was significantly higher than those in donor B and D (7.77 ± 3.26, 5.85 ± 2.10 and 7.03 ± 2.14 vs. 4.68 ± 2.61 and 5.21 ± 1.97 oocytes), but donor A was significantly higher than donor C (p<0.05). Development to blastocyst in donor B, C and E was significantly higher than those in donor A and D (31.0, 25.0 and 25.0% vs. 14.3 and 4.5%), but donor A was not different in donor C and E (p<0.05). Nine out of 10 blastocysts (90.0%) derived from OPU blastocysts were confirmed male embryos that was induced with Y-bearing semen to confirm sex ratio only. Total 96 blastocysts derived from female bearing semen were transferred into synchronized recipients and then confirmed 42 recipients (43.8%) pregnancy rate, 36 offspring (37.5%) and 91.7% female sex ratio (33 female vs. 3 male offspring). Taken together all data, elite dairy female offspring could be produced effectively by in vitro production system between pre-selected x-bearing semen and OPU derived oocytes that would be influential breeder in the breeding of dairy farm to increase effectively elite dairy offspring ratio as well as net income in the dairy farmer.

High Postnatal Survival and Efficacy of Female-Derived Donor Cells in the Productive of Somatic Cloned Piglets

Seong Keun Cho,Mi Ryung Park,Kyu Chan Hwang,Deug Nam Kwon,Yeo Jeoung Im,Ju Joung Park,Woo Jin Son,Jin Hoi Kim 한국동물번식학회 2003 Reproductive & Developmental Biology(Supplement) Vol.27 No.1s

A Comparison of the Clinical Outcomes of Decompression Alone and Fusion in Elderly Patients with Two-Level or More Lumbar Spinal Stenosis

Son, Seong,Kim, Woo Kyung,Lee, Sang Gu,Park, Chan Woo,Lee, Keun The Korean Neurosurgical Society 2013 Journal of Korean neurosurgical society Vol.53 No.1

Objective : We compared the results of two surgical techniques by retrospective study of 60 elderly patients (65 years or older) who underwent either decompression alone or fusion for the treatment of two-level or more lumbar spinal stenosis. Methods : During the period of 2003 and 2008, two-level or more decompression alone or fusion was performed for lumbar spinal stenosis by three surgeons at our institution. Patients were allocated to two groups by surgical modality, namely, to a decompression group (31 patients) or a fusion group (29 patients). Overall mean age was 71.1 years (range, 65-84) and mean follow-up was 5.5 years (range, 3-9). A retrospective review of clinical, radiological, and surgical data was conducted. Results : No significant difference between the two groups was found with respect to age, follow-up period, surgical levels, or preoperative condition. At the last follow-up, correction of lumbar lordotic angle (determined radiologically) was better in the fusion group. However, clinical outcomes including visual analogue scale, Oswestry Disability Index, and the Odom's criteria were not significantly different in the two groups. On the other hand, surgical outcomes, such as, operation time, estimated blood loss, and surgical complications were significantly better in the decompression alone group. Conclusion : Our findings suggest that decompressive laminectomy alone achieves good outcomes in patients with two-level or more lumbar spinal stenosis, associated with an advanced age, poor general condition, or osteoporosis.

High Postnatal Survival and Efficacy of Female-Derived Donor Cells in the Productive of Somatic Cloned Piglets

Seong Keun Cho,Mi Ryung Park,Kyu Chan Hwang,Deug Nam Kwon,Yeo Jeoung Im,Ju Joung Park,Woo Jin Son,Jin Hoi Kim 한국동물생명공학회(구 한국동물번식학회) 2003 Reproductive & developmental biology Vol.27 No.1

Gastritis Cystica Profunda 를 동반한 위의 염증성 섬유양 용종 1예

손희정,김재준,박철근,전성국,오영륜,고재향 대한소화기내시경학회 1997 Clinical Endoscopy Vol.17 No.5

Inflammatory fibroid polyp(IFP) typically prescnts as a polypoid mass in the gastric antrum. Radiologically and endoscopically, it can be confused with polypoid carcinoma or submucosal stromal tumor. The histogenetic origin of IFP has been controversial, but it is considered as a reactive lesion of the myofibroblastic nature. IFP is rarely concomitant with gastritis cystica profunda(GCP) which is also one of the nonneoplastic inflammatory polyps. We report a case of IFP associated with GCP presenting as a large polypoid mass in the previously unoperated stomach of a 78-year-old woman. The mass was mainly located in the submucosa of the antrum and the cut surface exhibited a myxoid and glistening appearance with partial cystic change. Histologically, the mass showed marked proliferation of spindle cells, small blood vessels and many inflammatory cells, especially eosinophils. Also, there were many variable sized glands composed of gastric foveolar epithelia within the mass. In conclusion, the rarity of these two associated lesions in the present case may cause difficulty in diagnosis, and therefore recognition about these lesions is needed. In addition, this case supports the nature of IFP as being reactive rather than neoplastic.

Novel Zinc Precursors for ZnO Thin Film Deposition by ALD

Seong Ho Han,Raphael Edem Agbenyeke,Ga Yeon Lee,Bo Keun Park,Chang Gyoun Kim,Young Kuk Lee,Seung Uk Son,Taek-Mo Chung 한국진공학회 2020 한국진공학회 학술발표회초록집 Vol.2020 No.8

Synthesis of Cobalt Oxide Film by Thermal Decomposition for Potential Various Applications

Seong Ho Han,Bo Keun Park,Seong Uk Son,Chang Gyoun Kim,Taek-Mo Chung 한국진공학회 2014 한국진공학회 학술발표회초록집 Vol.2014 No.2