• Title/Summary/Keyword: Material Removal

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A STUDY ON TOOTHBRUSH ABRASION OF CERVICAL RESTORATIVE MATERIALS (치경부 심미수복재의 잇솔질 마모에 관한 연구)

  • Baik, Byeong-Ju;Yang, Jeong-Sook;Lee, Doo-Cheol;Kim, Jae-Gon
    • Journal of the korean academy of Pediatric Dentistry
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    • v.28 no.1
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    • pp.118-128
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    • 2001
  • This study was performed to evaluate the toothbrush abrasion characteristics of seven commercially available light-cured cervical restorative materials one resin-modified glass-ionomer material(Fuji II LC) three polyacid-modified composites(Compoglass, Dyract, F2000), and three light-cured composites(Heliomolar, Palpique Estelite, UniFil F). All samples were stored in distilled water at $37^{\circ}C$ for 10 days. 2.0N of weight was loaded during the test and the abraded surfaces were examined with profilometer and SEM after 100,000 cycles. The results obtained were summarized as follows; 1. The highest hardness value of 79.7 was observed in the FT group and the lowest value of 20.0 was observed in the HM group. Results of Tukey test showed that an overall significant difference was indicated except the CG and DR groups(p<0.05). 2. The highest surface roughness was observed in the FL group and the lowest was observed in the UF group. Results of Tukey test showed the significant difference between the FL or FT and UF groups(p<0.05). 3. Statistically higher abrasion and surface roughness were observed for the dentifrice of paste type, Perio A+, than for that of gel paste type, Tom & Jerry. 4. The surface roughness values increased on the abraded surfaces because of the protrusion of filler particles due to selective removal of matrix resin.

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Effect of Bagging Material and Removal Time on Soluble Solid and Fruit Color of Oriental Melon(Cucumis melo L. var makuwa Makino) (봉지종류 및 제거시기가 참외의 당도 및 색도에 미치는 영향)

  • Shin, Yong-Seub;Lee, Ji-Eun;Yeon, Il-Kweon;Do, Han-Woo;Cheung, Jong-Do;Kang, Chan-Ku;Choi, Chung-Don;Choi, Seng-Yong
    • Journal of Bio-Environment Control
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    • v.17 no.2
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    • pp.157-161
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    • 2008
  • This experiment was conducted to make eatable fruit of oriental melon with peel, we covered oriental melon fruit with pear, apple and grape paper bag. Temperature inside paper bags was lower than air temperature in daytime but reversed in night. Relative humidity inside paper bags was higher than outside humidity in daytime but reversed in night. Covering with paper bags seemed to make fruit length shorter, fruit width narrower, flesh thickness thinner and fruit weight heavier but no difference was found among treatments. Soluble solid contents of flesh and placenta seemed lower with covering with paper bags but also difference did not find among treatments. Increasing of soluble solid contents of fruits was observed at 5 days after removing paper bags but not immediately at removing paper bags. Fruit hardness and chromaticity were dropped by covering paper bags. Decrease of fruit hardness by covering paper bags made more eatable with peel but more study have to be taken to improve chromaticity and soluble solid of fruits.

Trichloroethylene (TCE) Removal Capacity of Synthesized Calcium Sulfoaluminate Minerals in Hydrated Cement-based Materials (합성 Calcium Sulfoaluminate계 시멘트 수화물의 Trichloroethylene (TCE) 제거능)

  • Ha, Min-Gyu;Ghorpade, Praveen A.;Kim, Jeong-Joo;Park, Joo-Yang
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.4
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    • pp.1463-1469
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    • 2013
  • Portland cement used as binding material in combination of ferrous iron for reductive dechlorination of chlorinated organics is already widely studied topic by several researchers. However there is no clear evidence about the component solely responsible in cement for trichloroethylene (TCE) dechlorination. Many researchers suspect that the ettringite, monosulfate phases associated with hydration of cement are responsible active agents for TCE dechlorination. This study deals with synthesizing different pure crystalline minerals like ettringite and monosulfate phases of cement hydration and check individual phase's TCE dechlorinating capacity in combination with ferrous iron. The results indicated that the synthesized minerals showed no reduction capacity for TCE. The findings in the present study is significant as it shows that ettringite and monosulfate phases which were suspected minerals by previous researchers for TCE dechlorination are not reactive. Hence it is suspected that some other mineral or mineral form in cement phase could be responsible for TCE degradation.

Intercalary Tricortical Iliac Bone Graft in the Surgical Treatment of Nonunion of Midshaft Clavicular Fractures (쇄골 간부 불유합에서의 개재 삼면피질 장골 이식술)

  • Cho, Chul-Hyun;Jang, Hyung-Gyu
    • Clinics in Shoulder and Elbow
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    • v.15 no.1
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    • pp.32-36
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    • 2012
  • Purpose: The purpose of this study was to evaluate the radiologic and clinical outcomes after intercalary tricortical iliac bone graft with plate fixation for the nonunion of midshaft clavicular fractures. Material and Methods: Between September 2007 and May 2011, 10 patients who were treated by the intercalary tricortical iliac bone graft, with plate fixation for clavicle nonunion, were studied. The mean follow-up period was 30.7 (12~57) months. After the sclerotic bone was excised to the bleeding cortical bone, we interposed the tricortical iliac bone to provide structural support and restore clavicle length, and then fixed the plate and screws. The radiologic outcomes on the serial plain radiographs and clinical outcomes, according to UCLA, ASES and Quick DASH scores, were analyzed. Results: Bony union was obtained in all cases (100%) and the average union time was 18.4 (14~24) weeks. The average respective UCLA and ASES scores improved from 16.7 and 52.1 preoperatively to 27.4 and 83.6 postoperatively (p<0.05). The average Quick DASH score was 40.5, at the final follow-up. Complications were 2 shoulder stiffness, and one case had removal of device and arthroscopic surgery at 11 months, postoperatively. There were no implant failure or infection. Conclusion: Intercalary tricortical iliac bone graft, with plate fixation for the nonunion of midshaft clavicular fractures, is a good option that can provide structural support and restore clavicle length, as well as high union rate.

External Fixation of Retaining Ligament in Correction of Facial Disfigurement in Type-1 Neurofibromatosis Patients (유지 인대의 외부 고정을 통한 제1형 신경섬유종증 환자의 안면부 변형 교정)

  • Myung, Yu-Jin;Lee, Yoon-Ho
    • Archives of Plastic Surgery
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    • v.38 no.3
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    • pp.257-262
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    • 2011
  • Purpose: In neurofibromatosis patients, complete surgical excision of the mass is almost impossible and surgical treatment usually consists of multiple serial excisions that only result in a debulking effect. Remnant tumor mass has a gravitational effect on facial soft tissues that leads to sagging of skin and soft tissue, and eventually, facial disfigurement and asymmetry. The purpose of our surgical method is to perform soft tissue lifting with longer lasting effect with less surgical risk of damaging facial nerve and vessels. With external fixation using K-wire or surgical screw, the procedure only called for a short incision length and had additional adhesive properties that enabled anchoring of soft tissue in a lifted position for a longer postoperative period. Methods: A total of 5 neurofibromatosis patients (NF-1) visited our clinic for mass reduction and face lifting. The age of patients ranged from 13 to 42 (mean 28.8 years), and most patients had a long history of multiple excisions in the past. Face lifting was performed in 2 different areas, the periorbital area in 3 patients, and the midface in 2 patients. The materials used in fixation of retaining ligament were K-wire (n=3) and titanium screw (n=2). Results: Follow up period was from 5 month to 3 years and 1 month (mean=2 years and 1 month). All patients conveyed satisfaction with the results and no major complications were reported. The lifting effect lasted for as long as 3 years, and there were no complaints of relapse of soft tissue depression or sagging within the operated area. 1 patient (M/13) needed secondary k-wire insertion and additional mass excision in 1 year and 10 months postoperatively due to tumor growth. In two patients with K-wire fixation, mild dimpling and tenderness were observed in the follow up period, but in about 2 months postoperatively, dimpling was relieved and there was no need for removal of fixating material. Conclusion: Surgical lifting in neurofibromatosis patients can be challenging, for mass excision cannot be done completely and gravitational effect by residual mass can be persistent. External fixation of the retaining ligament in patients with neurofibromatosis can give satisfactory results-for incision length is relatively shorter, and the lifting effect can last longer compared to other various face lifting techniques.

The Local Effect after Surgery in Non-small Cell Lung Cancer (비소세포성 폐암에서 수술 후의 국소 제어효과)

  • Sa, Young-Jo;Jeon, Hyun-Woo;Lee, Sun-Hee;Wang, Young-Pil;Park, Jae-Kil
    • Journal of Chest Surgery
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    • v.40 no.5 s.274
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    • pp.356-361
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    • 2007
  • Background: Recent progress in the surgical therapy for lung cancer is one of the best examples of the successful evolution of clinical medicine. We reviewed our experience to evaluate the surgical outcomes in patients with non-small cell lung cancer. Material and Method: We reviewed clinical records of 432 consecutive patients with proven non-small cell lung cancer who underwent complete removal of the primary tumor together with hilar and mediastinal lymph nodes from 1995 to 2005. The clinical characteristics, surgical methods, and recurrence patterns were analyzed. Result: Lobectomy was the most common procedure (66.7%) performed and sleeve lobectomy was the least (5.6%). In 179 patients (42.6%) the recurrence was noted and the regional recurrence (67 cases, 16.0%) was less than systemic recurrence (112 cases, 26.7%). The main sites of regional recurrence were hilum (25 cases, 37.3%) and ipsilateral mediastinum (54/432 cases, 25.4%). The hospital mortality rate was 2.8% (12/432 cases) and resection-morbidity rate was 12.5% (54/432 cases). Conclusion: The low recurrence rate, especially regional recurrence rate indicated that our surgical procedures with preoperative measures were considered useful and effective.

A Study on the Utilization with the Protein Forthification Material of Skip-jack Dark Meat Protein by Enzymatic Hydrolysis (효소 분해에 의한 가다랭이 혈합육 단백질 농축물의 단백질 보강제로서의 이용에 관한 연구)

  • 우강융;배영정
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.24 no.2
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    • pp.323-329
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    • 1995
  • For the effective utilization of dark meat separated as by-product from skip-jack canning, the dark meat concentrate(DPC) was prepared by removal of extractable materials with ethanol from dried dark meat. Dark meat protein hydrolysate(DPH) was prepared by the hydrolysis of DPC with ${\alpha}-chymotrypsin$. ${\alpha}-Chymotrypsin$ hydrolysed DPC to the extend of 79% during 10hr. The solubility over a pH range 1~12 showed similar trend on the both of DPH and DPC. The highest solubility was 81% on the DPH and was 36% on the DPC at pH 3. The lowest solubility was 65% on the DPH and was 22% on the DPC at pH 7. The content of total free amino acid was higher in the DPC than in the DPH, but the content of total essential free amino acid was higher in the DPH. Especially, the contents of taurine in the DPC and DPH were much higher than those of other amino acids. The result of sensory evaluation on the fish sauce analogue showed good taste, color and odor at the supplemented level of 8g DPH per 100ml of raw solution of fish sauce analogue and didn't show signifcaint difference compared with market fish sauce(p<0.05). On the preparation of surimi gel, 2% substitution of DPH for the supplemented starch was the most appropriate level.

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Comparison of Tariff Structures of Forest Products Between Korea and China (한-중 임산물관세구조 비교분석)

  • Chang, Cheol-Su;Lee, Sang-Min
    • Journal of Korean Society of Forest Science
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    • v.97 no.1
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    • pp.102-112
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    • 2008
  • The main purpose of this study is to provide informations by comparing and analyzing tariff structures for the upcoming FTA negotiation between Korea and China. China is the biggest trade partner of Korea, sharing 33% of total trade value of forest products. However, import takes majority of trade value and it grows constantly. The results of FTA negotiation may have large impacts on Korean forest industry. The conclusions indicate that China subdivides items more complicatedly, and impose lower tariffs on forest products except stone than Korea. Besides, China has tariff escalation system that imposes lower duties on raw material than the manufactured, and also charges different rates of tariff on items of the same heading number according to the degrees of manufacturing. Furthermore, Korea imposes adjustment duties and didn't grant concessions on plywood and board items for protection of domestic industries, however, China already made concessions on all items. As a result of this, it will be unavoidable for Korea to increase import value from China, and tariff removal will have more negative impacts on Korea than China.

Subvalvular Septal Myectomy and Enlargement of the Narrow Aortic Root in Patients with Aortic Valve Replacement

  • Schulte, H.D.;Birchs, W;Horstkotte, D;Kim, Y.H.;Kerstholt, J;Preusse, C.J.;Winter, J
    • Journal of Chest Surgery
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    • v.22 no.2
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    • pp.220-224
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    • 1989
  • In candidates for aortic valve replacement [AVR]it is our primary intention to implant the largest possible vale prosthesis of at least 23 mm in diameter in patients with severe valvular aortic stenosis. However, in many patients there is an additional subvalvular asymmetric septal hypertrophy which in some cases may cause an postextrasystolic increase of the LV-aortic gradient. Another component of the aortic stenosis syndrome is a narrow valvular ring, or a combination of both. After complete removal of the diseased valve and decalcification the narrow aortic ring [< 23 mm] can be widened firstly by transaortic subvalvular septal myectomy- [TSM] thus unfolding the left ventricular outflow tract[LVOT]and secondly by extending the oblique aortic incision into the aortic valve ring or further down into the anterior leaflet of the mitral valve. The sub-and supra-valvular defect will be closed by patch enlargement of the aortic root [PEAR] using autologous pericardium. These techniques allow a considerable enlargement of the valvular ring of about 4 to 10 mm in circumference. In a retrospective study using a computerized program, 847 patients with AVR [1980-1984]were reviewed to evaluate the intraoperative hemodynamic results mainly concerning relief of the transvalvular gradient. In 626 patients AVR was performed, 151 patients had double valve replacement [AVR+MVR], and 70 patients had AVR plus additional surgical procedures. Concentrating on the AVR-group [n=626] there were 103 patients with TSM, 24 patients with PEAR and 20 patients with TSM+PEAR which demonstrated that in a total, of 147 patients of this groups [23.5%] an additional procedure was necessary. The Statistical evaluation of the intraoperative pressure measurements before and after AVR in relation to the size of the implanted prostheses indicated the lowest preoperative mean gradient in patients with AVR alone, the highest in patients who afforded TSM plus PEAR. However, after AVR the mean gradients in all three groups were very low [mean 5 to 10 mmHg]. These data indicate that in patients with a narrow aortic ring and additional considerable ASH, TSM and PEAR are suitable techniques to enlarge the aortic root to enable the implantation of an adequate aortic valve prosthesis. Long-term controls have shown that autologous pericardium is a qualified graft material for the ascending aorta.

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The Effects of SO2 and NH3 on the N2O Reduction with CO over MMO Catalyst (MMO 촉매와 CO 환원제에 의한 N2O 분해에서 SO2 및 NH3 영향 연구)

  • Chang, Kil Sang;You, Kyung-Chang
    • Applied Chemistry for Engineering
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    • v.20 no.6
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    • pp.653-657
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    • 2009
  • Nitrous oxide is a typical greenhouse gas which is produced from various organic or fossil fuel combustion processes as well as chemicals producing plants. $N_2O$ has a global worming potential of 310 times that of $CO_2$ on per molecule basis, and also acts as an ozone depleting material in the stratosphere. However, its removal is not easy for its chemical stability characteristics. Most SCR processes with several effective reducing agents generally require the operation temperature higher than $450^{\circ}C$, and the catalytic conversion becomes decreased significantly when NOx is present in the stream. Present experiments have been performed to obtain basic design data of actual application concerning the effects of $SO_2$ and $NH_3$ on the interim and long term activities of $N_2O$ reduction with CO over the mixed metal oxide (MMO) catalyst derived from a hydrotalcite-like compound precursor. The MMO catalysts used in the experiments, have shown prominent activities displaying full conversions of $N_2O$ near $200^{\circ}C$ when CO is introduced. The presence of $SO_2$ is considered to show no critical behavior as can be met in the $NH_3$ SCR DeNOx systems and the effect of $NH_3$ is considered to play as mere an impurity to share the active sites of the catalysts.