• 소성∙가공
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• 제14권4호
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• pp.360-367
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• 2005

The injection-molded plastic parts have many surface defects: warpage, weldline, flowmark, zetting, scratching, shading and so on. As weldline was one of the major surface defects in the case of desktop monitor, warpage and surface shrinkage are the bigger problems of LCD monitor in the pursuit of light weight and thinner thickness of parts. Some measures to improve these defects were introduced in this paper. Based on these, the laboratory work to find out the optimum processing conditions and to get the best parts was repeated injection moulding try-out after reflecting these improvements. The defects of warpage and surface shrinkage was significantly improved after the improvements in the case of the 20.1 inch even if in the 15 and 17inch case the warpage size was a lttle over the allowed specification because of not taking the measure for parts design within the allowable limits from the required specification in the cause of cost down.

• Archives of Plastic Surgery
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• 제45권6호
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• pp.550-556
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• 2018

Background To achieve improvements in intramuscular injection, autologous fat grafting, and gluteal artery perforator flaps in infants and children, the relationships of computed tomography (CT)-determined gluteal muscle thickness (MT) and subcutaneous tissue thickness (SCT) with age and body mass index (BMI) were analyzed. Methods Gluteal SCT and MT at ventrogluteal (VG) and dorsogluteal (DG) sites were measured in a standardized manner in 350 patients aged 0 to 6 years who had visited a tertiary hospital and had undergone abdominopelvic CT between January 2005 and December 2016. Recorded measurements were analyzed using one-way analysis of variance and stepwise multiple regression to identify the factors that were most closely related to MT and SCT. Results Subcutaneous tissue at VG sites was thinner than at DG sites, but not significantly so in any age group. Muscles tended to be thinner at VG sites in 4 to 7-year-old, but thicker at VG sites in 1 to 3-year-old, though the differences were not significant. MT in the VG and DG regions was found to be related to age, and SCT in these regions to be related to age and BMI. Conclusions The VG and DG sites should be considered as alternatives for intramuscular injection in infants and children when the anterolateral site is problematic. In addition, considering the gluteal MT and SCT of infants and children should help produce good results in autologous fat grafting and gluteal artery perforator flap harvesting.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.99-102
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• 2009

The recent LCD TV market has made efforts to produce thinner, brighter, and clearer products, and experienced the rapid light source replacement from a line source of light CCFL to a point source of light LED. In particular, LGP(Light Guiding Panel) among key parts composing BLU(Back Light Unit) has limits of the injection molding technology as well as the mold design, its processing and manufacturing technology so that it is hard to produce large LGP over 40 inch. To produce large light-guide panels over 40 inch under the injection molding process, a mold 3D model was developed in the design process before manufacturing a mold and structure unification was processed through CAE analysis. As a result, it was possible to construct the mold design process, and it is expected to manufacture the optimized mold by applying the mold design and manufacturing process of large-scale rapid injection-compression molding that will be produced in the future.

• 대한치과교정학회지
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• 제12권1호
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• pp.7-14
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• 1982

In this study, effects of cyclophosphamide on the growth of the mandibular condyle head were investigated with Spraque-Dawley rats of the 28 days of age. Rats were devided into four groups. Three were used as experimental groups, and one as control. Each rat in experimental group was injected intraperitoneally with cyclophosphamide repeatedly three times, 20mg/kg for the first group, 40mg/kg for the second, and 60mg/kg for the third each time. Rats in control group were injected with physiological saline in the same method. Rats in each group were sacrificed at 5, 10, and 15 days following the last injection. The specimens were stained with H-E, toluidine blue, PAS, and alcian blue. The results were as follows; 1. In experimental group, with increasing the injection doses, the thickness of the condylar cartilage from the transitional zone to the hypertrophic zone became thinner than in control group. 2. Weaker metachromasia to toluidine blue and less positive reaction to PAS were seen. 3. In primary marrow cavity the fewer trabecular was formed, The direction of trabecular formation became obscuerer, and the lower density of bone was resulted in.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제22권2호
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• pp.142-154
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• 2000

The purpose of this study is to evaluate the difference in healing of $Medpor^{(R)}$ implants of two different thickness (1.5mm and 4.5mm) and the effects of methylprednisolone on the healing process. Light microscopic and scanning electron microscopic examinations, and hardness measurement were made in 100 rats 2, 4, or 8 weeks postoperatively. The 1.5mm thin implants were taken better than the 4.5mm thick implants. The inflammatory responses were reduced after application of methylprednisolone with arrangement and amount of bone matrix deposited being more irregular and reduced in bulk than in the control group. To hasten postoperative healing after $Medpor^{(R)}$ implantation, the thinner material should be used and steroid injection should be avoided.

• Archives of Reconstructive Microsurgery
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• 제6권1호
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• pp.80-86
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• 1997

The lateral arm flap was reported first by Song et al. in 1982, and Katsaros and colleagues described an anatomic study and clinical cases in 1984. This flap is thin, has relatively constant vascular anatomy, and provides relatively acceptable scar at the donor site. Despite its many advantages its wide application has been limited by its short vascular pedicle with small diameter of lumen, and its small skin paddle. We studied its anatomical structure to get longer length of vascular pedicle, wide diameter and thinner part of flap beyond the lateral condyle through 6 fresh cadaver dissection and dye injection study. We experienced 21 cases of lateral arm free flaps and 26 cases of forearm free flaps from May, 1992 to January, 1996. We compared its usefulness with forearm free flaps in the aspects of donor morbidity, operative factors, quality of flap, and versatility. In conclusion, lateral arm flap can replace the role of forearm flap in most cases so that patient's donor morbidity can be reduced especially in the women.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1116-1121
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• 2004

In this study, the effect of central fuel injection on a coaxial laminar $CH_{4}/air$ flame was experimented at the defined premixing condition(${\Phi}=1.90$, ${\sigma}=50/75/100%$, x/D=10). The partial premixing parameter are the equivalence ratio that total fuel is fixed at 200cc/min, the fuel split degree which means the percentage of fuel entering the outer tube to the total amount, and the mixing distance indicating the nonreactant mixture's homogeneity between inner tube top and burner exit. The object is to investigate the flame structure and chemiluminescence characteristics of laminar partial premixed flame as changing mixing parameters. The radical signal was acquired from ICCD camera and PMT. Each intensity was compared with Abel inverted value for measuring the effect of background light on the peak signal location and the intensity at central preheat zone. The results show that the peak location of each radical was broaden as the fuel split degree increasing because the mixing quality was enhanced. and $OH^{\ast}$ is a good indicator for flame front between reaction and preheat zone. At last $CH_{2}^{\ast}$ has the same tendency with $CH^{\ast}$ but a thinner reaction zone than $CH^{\ast}$ due to a rapid decay on the burned gas side.

• 한방안이비인후피부과학회지
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• 제10권1호
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• pp.1-38
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• 1997

This study was performed to investigate the effects of Kamigyemyoungsan and each compositive herbs on the intravascular coagulation and subcutaneous hematoma. The intravascular coagulation was induced by the injection of endotoxin into the caudal vein of the rats. These rats were treated with endotoxin after administering orally extracts of Kamigyemyoungsan and each compositive herbs. Then the number of platelet, prothrombin time, the concentration of fibrinogen and FDP(fibrinogen degration product), hematocrit and RBC and WBC were measured. The subcutaneous hematoma was induced by the subcutaneous injection of the autologous whole blood to produce clotting in situ in rats. Then the extracts of Kamigyemyoungsan and each compositive herbs were administered orally. The lesions were then dissected and observed. The results were obtained as follows ; 1. The number of platelets of the trial groups was increased as compared with the control group, and revealed significance in sample Ⅰ. 2. The concentration of fibrinogen of the trial groups was increased as compared with the control group, and revealed significance in sample Ⅰ, sampleⅡ and sample Ⅴ. 3. The prothrombin time was shortened significantly in the trial groups, except sampleⅡ and sampleⅣ as compared with the control group. 4. The concentration of FDP decreased in the trial groups, and revealed significance in sample Ⅰ and sample Ⅵ as compared with the control group. 5. The hematocrit significantly increased in sample Ⅰ, sampleⅢ and sample Ⅵ as compared with the control group. 6. The number of RBC significantly increased in sample Ⅵ only as compared with the control group. 7. The number of WBC significantly increased in the trial groups, except sampleⅣ and sample Ⅵ as compared with the control group. 8. Histologically, the lesions in the trial groups showed significantly thinner fibroblastic neomembrane than the control group, except sampleⅢ. According to the above results, it is considered that Kamigyemyoungsan and each compositive herbs have inhibitive effects on the thrombosis and the fibroblastic neomembrane development. Therefore, it seems to be applicable to the diseases related to thrombosis and hematoma.

• 한국조명전기설비학회지:조명전기설비
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• 제2권1호
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• pp.65-74
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• 1988

광표시전극의 저항이 작은 NESA glass($In_2O_3$ 또는 $SnO_2$)로 Electro Chromism Display 소자를 마들어 주입하밀도, 광학밀도 그리고 응답특성 등을 착소광현상으로 실험한 결과, $WO_3$와 Cell내에 광전기화학반응을 일으키기 쉬운 물질이 함유된 경우에는 착소광의 반복이 가능하였고 착광특성이 좋았다. 착소광전압이 높을수록 전극저항이 낮을수록 또 $WO_3$박막이 얇을수록 반응특성이 좋아졌다. 따라서 Electro Chromism(EC)의 현상을 분석한 결과 착소광소자로서 시계, 계기, 행선안내판 등에 쓰이는 실용가능성을 발견하였다.

• 한국공작기계학회논문집
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• 제18권2호
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• pp.130-136
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• 2009

Semi-solid casting(SSC) of magnesium alloys is increasingly being used to produce high quality components. This process is similar to the injection molding of plastics and is called thixomolding. Using this process, higher strength, thinner wall sections and tighter tolerances without porosity are obtained. The high strength and low weight characteristics of magnesium alloys render the high-precision fabrication of thin-walled components with large surface areas. They are widely used for the IT, auto and consumer electronics industries. However, warpage of the thin-walled sections degrade quality of the parts produced in the SCC process. To produce thin-walled magnesium alloy parts, the geometry of gating system on the quality of the finished products should be clearly studied. In this paper, to minimize warpage of the thin-walled sections, Taguchi method is applied to the optimal design of the gate geometry in the thixomolding process. Width, height, length and angle of the gating system are selected for the robust design parameters. Effectiveness of the robust design is verified through the CAE software.