• 환경위생공학
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• 제17권4호
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• pp.10-18
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• 2002

The changes of conventional clarification processe and an increase in treatment cost are required to meet increasingly stringent regulations related to the treated water quality. Although many enhanced coagulations have introduced to improve organic matter removal, the results to remove color, nitrogen and phosphorus as well as organic material have not been very efficient yet. In this context as new flocculation using calcium hydroxide and magnesum sulfate was carried out. The removal of waste matters such as SS, organic matter, COD, nitrogen and phosphorus contained in stock wastewater was carried out by using the combination of calcium hydroxide and magnesium sulfate. The flocculation was investigated as a function of coagulant dose, pH, mixing time, settling time and coagulant addition modes such as the sequential addition of the two coagulants and the simultaneous addition of them. The flocculation by the combination of calcium hydroxide and magnesium sulfate was compared with that by aluminum sulfate. The mechanism of flocculation was investigated as well. About 60% of COD in stock watewater was removed by flocculation with combination of calcium hydroxide and magnesium sulfate.

• Journal of Periodontal and Implant Science
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• 제32권2호
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• pp.325-338
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• 2002

Bone graft using growth factors and guided tissue regeneration have been used for the regeneration of infrabony defects which caused by periodontal disease. Calcium sulfate which is one of the resorbable barrier materials used for guided tissue regeneration. Platelet rich plasma which is a easy method to obtain the growth factors had many common points but, platelet rich plasma was still studying. This study was the comparative study between bone graft using platelet rich plasma and guided tissue regeneration using calcium sulfate barrier material in clinical view. For the study, 28 sites(2 or 3 wall infrabony defects) were treated. 14 infrabony defects were received surgical implantation of BBP-calcium sulfate composite with a calcium sulfate barrier and the others received BBP mixed with platelet rich plasma. Clinical outcome was accessed 3 and 6 months of postsurgery. 1. There was no statistical difference between CS group and PRP group in pocket depth, gingival recession, clinical attachment level, and probing bone level at baseline. 2. There was statistically significant reduction in probing depth, clinical attachment level, and probing bone level at 3 and 6 months postsurgery(p<0.05). 3. In the probing depth and clincial attachment level PPR group had less improvement than CS group, but there was no statistically difference at 3 and 6 months postsurgery. 4. In the recession PPR group had less recession than CS group, but there was no statistically difference at 3 and 6 months postsurgery. 5. In the probing bone level PPR group had less improvement than CS group, but there was no statistically difference at 6 months postsurgery. In conclusion bone graft using platelet rich plasma and guided tissue regeneration using calcium sulfate barrier showed similar clinical improvement for the treatment of 2 or 3 wall infrabony defects.

• Journal of Korean Neurosurgical Society
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• 제30권5호
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• pp.605-610
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• 2001

Objective : The authors investigated the efficacy of the calcium sulfate(OsteoSet$^{(R)}$ pellets) as an autograft extender when used to perform posterolateral lumbar fusions. Patients and Methods : Twenty patients who underwent lumbar posterolateral arthrodesis for various spinal diseases between October 1999 and March 2000 were evaluated. Arthrodesis was performed by transpedicular screw fixation and bone grafting with a mixture of autograft + calcium sulfate in a 1 : 1 ratio. At time intervals of 1, 2, 3, and 6 months, postoperative radiographs were obtained to review the resorption of calcium sulfate and the evidence of fusion. A modified Lenke scale was used to assess the status of the fusion. Results : At 2 months after operation, the average modified Lenke scale score for the OsteoSet$^{(R)}$ pellets group was 3.8. However at 6 months after operation, the average modified Lenke scale score for the OsteoSet$^{(R)}$ pellets group was 1.8. Resorption of calcium sulfate pellets was revealed in all cases at 6 months after surgery. Conclusion : It is presumed that a combination of calcium sulfate and autograft can play a role as an effective autograft extender in the posterolateral spinal fusion.

• Journal of Periodontal and Implant Science
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• 제27권2호
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• pp.347-361
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• 1997

The present study investigates the effects of DFDB graft combined with Calcium sulfate membrane on the periodontal wound healing in dehiscence defects of dogs. Following the initiation of general anesthesia by I.V. administration of 30mg/kg of pentobarbital, first premolar was extracted and full-thickness flap was elevated from the second to the fourth premolar. The portion of premolars coronal to the alveolar crest was removed and mesial and distal roots separated to produce single rooted teeth. Exposed root canals were sealed with Caviton and covered completely with flaps sutured. Following the healing period of 12 weeks, the surgical sites were uncovered and $4{\times}4mm$ dehiscence defects were surgically created. Those defects with DFDB graft combined with Calcium sulfate membrane following root planing, were designated as test sites and those with flap surgery-only were designated as controls. 1. No foreign-body reaction or inflammation were observed in either groups. Calcium sulfate was completely resorbed in the test sites. 2. Significantly greater amounts of new cementum was observed in test sites compared with the controls. Significant amounts of functionally orientated collagens were observed in the test sites. 3. New bone formation was observed in significantly greater amounts in test sites. The results suggest that combined graft of DFDB and calcium sulfate is extremely biocompatible with a potential for new bone and cementum formation, and functional alignment of periodontal ligaments.

• Journal of Periodontal and Implant Science
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• 제27권1호
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• pp.249-262
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• 1997

The present study investigates the effects of calcium sulfate graft on the periodontal healing in intrabony periodontal defects of dogs. Following the general anesthesia with 30mg/kg pentobarbital injected intravenously, the first premolar was extracted and full-thickness periodontal flap was elevated from the second premolar to the fourth premolar. The portion of premolars coronal to the alveolar crest was removed and mesial and distal roots were separated. Exposed root canals were sealed with Caviton and covered completely with flaps sutured. Following the healing period of 12 weeks, the surgical sited were uncovered and $4{\times}4mm$ intrabony defects were surgically created. Those defects with calcium sulfate graft following the root planing was designated as the test sites and those with flap surgery-only were designated as control sites. The animals were sacrificed after 8 weeks and the healing was histologically analyzed. The results were as follows. 1. No foreign body reaction or inflammation were observed in either groups. Calcium sulfate was completely resorbed in the test sites. 2. New cementum was observed coronal to the notch in both groups. Connective tissue fibers were oriented parallel to the root surface in the controls. Connective tissues were formed in large amount in the sites. 3. Test sites showed marked amount of new bone formation while the control sites showed minimal bone gain. 4. Root resorption was observed in coronal portions of th control Sites. The results suggest that calcium sulfate is a biocompatible graft material with a potential for new bone and cementum formation.

• 한국임상수의학회지
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• 제20권3호
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• pp.351-356
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• 2003

The aim of this experiment was to study the calcium sulfate on early bone consolidation in distraction osteogenesis in the canine mandible. Twelve dogs were used and divided into control group (group A, 4 heads), sodium hyaluronate injection group (group B, 4 heads), mixture of calcium sulfate and sodium hyaluronate injection group (group C, 4 heads). Each group were subdivided into 3 weeks testing group (totally 6 heads) and 5 weeks testing group (totally 6 heads). Mandibular distraction was started at the 5th day after the mandibular osteotomy and continued for 10 days by 1 mm a day. After the distraction on the 10th day of mandibular distraction, 0.5 m1 saline in group A, 0.5 m1 sodium hyaluronate in group B, and 0.5 ml mixture of calcium sulfate and sodium hyaluronate in group C were each injected in mandibular distraction lesion. And X-ray examination, bone mineral density, and histopathological findings were examined. The radiological findings were the most radiopaque in group C, and the most radiolucent in group A in both 3 and 5 week testing group. The level of bone mineral density was also the highest in group C, and the lowest in group C in both 3 and 5 week testing group. The histopathological findings of new bone formation were the most remarkable in group C in both 3 and 5 week testing group. New bone formation of group A was not present in both 3 and 5 week testing group. In conclusion, calcium sulfate is a kind of material that can stimulate early bone formation and can shorten the duration of bone consolidation. And it can be effective in clinical usage.

• 한국건축시공학회지
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• 제19권1호
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• pp.1-7
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• 2019

본 연구에서는 전력구 콘크리트 구조물에서 발생하는 균열저감을 위해 알파형 반수석고를 치환한 콘크리트의 역학적 특성을 평가하였다. 알파형 반수석고의 치환율은 0, 6, 9, 12, 15%로 설정하여, 응결시간, 압축강도, 건조수축을 측정하였으며, 미세구조 및 결정구조의 분석을 실시하였다. 실험 결과, 알파형 반수석고의 치환율이 증가할수록 응결시간이 단축되었으며, 압축강도가 저하되는 경향을 확인하였다. 한편, 알파형 반수석고를 15% 치환할 경우 보통포틀랜드시멘트 콘크리트에 비해 건조수축이 약 60% 저감되는 효과가 나타났다. 따라서, 전력구 콘크리트 구조물에 알파형 반수석고를 치환한 콘크리트를 적용할 경우 균열저감 성능이 향상될 것으로 판단되며, 압축강도의 개선은 필요할 것으로 판단된다.

• Journal of Periodontal and Implant Science
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• 제27권2호
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• pp.363-377
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• 1997

The main goal of periodontal therapy is the regeneration of periodontal tissue which has been lost due to destructive periodontal diseases. Although conventional forms of periodontal therapy show sound clinical results, the healing results in long junctional epithelium. There have been numerous materials and surgical techniques developed for new attachment and bone regeneration. Bone grafts can be catagorized into: autografts, allografts, xenografts and bone substitutes. Synthetic bone substitute materials include hydroxyapatite, tricalcium phosphate, calcium carbonate, and Plaster of Paris. Calcium sulfate has found its use in dental practice for the last 30 years. Recent animal studies suggest that periodontal regeneration in 3 wall intrabony defect may be enhanced by the presence of calcium sulfate. And it is well known that 2 wall & 1 wall defect have less osteogenic potential, So we need to study the effect of calcium sulfate in 1 wall intrabony defect in dogs. The present study evaluates the effects of calcium sulfate on the epithelial migration, alveolar bone regeneration and cementum formation in intrabony defects of dogs. Four millimeter-deep one-wall intrabony defects were surgically created in the mesial aspect of anterior teeth and mesial & distal aspects of premolars. The test group received calcium sulfate grafts with a flap procedure. The control underwent flap procedure only. Histologic analysis following 8 weeks of healing revealed the following results: 1. The lengths of junctional epithelium were: 2.52mm in the control, and 1.89mm in the test group. There was no statistical significance between the two groups. 2. Alveolar bone formation were: 0.61mm in the control, and 1.88mm in the test group. There was a statistically significant difference between the two groups (p<0.05). 3. Cementum formations were: l.lmm in the control, and 2.46mm in the test group. There was a statistically significant difference between the two groups (p<0.05). 4. The length of CT adhesion were: O.97mm in the control, and 0.17mm in the test group. There was no statistically significant differences between the two groups These results suggest that the use of calcium sulfate in intrabony defects has little effect on junctional epithelium migration, but has significant effects on new bone and new cementum formations.

• 한국식품저장유통학회지
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• 제18권5호
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• pp.678-683
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• 2011

떫은감 분말 첨가 두부의 수율, 품질 및 저장성에 응고제의 종류(magnesium chloride, calcium chloride, calcium sulfate, glucono-${\delta}$-lactone)가 미치는 영향을 조사하였다. Glucono-${\delta}$-lactone으로 응고시킨 두부가 가장 높은 수율, hardness, chewness, crispness, overall acceptability 및 가장 낮은 L값, b값, pH, 침지저장액 탁도, 총균수를 보였다. Calcium sulfate와 calcium chloride으로 응고시킨 두부는 비교적 높은 L과 b값을 나타내었다. Magnesium chloride로 응고시킨 두부는 관능적 품질특성(firmness, taste, overall acceptability)이 glucono-${\delta}$-lactone 응고 두부와 상호 유의적인 차이가 없이 비교적 높게 평가되었다. 이러한 결과로써 glucono-${\delta}$-lactone과 magnesium chloride가 떫은감 분말 첨가 두부 제조에 적합한 응고제로 판단된다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.152-153
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• 2022

In this study, the mechanical properties of PHC Pile were investigated using α-calcium sulfate hemihydrate, an industrial by-product with excellent expansion performance. As a result, the compressive strength of PHC pile showed a tendency to be higher than that of general Portland cement (OPC).