• Title/Summary/Keyword: extrusion failure

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Determination of the Optimal Mixture Ratio for Extrudates of Job's-tear and Wheat Flour by Mixture Design Analysis (혼합실험계획법에 의한 율무와 밀가루의 압출성형 최적 배합 조건 설정)

  • Cho, Seok-Cheol;Kang, Byung-Sun
    • Korean Journal of Food Science and Technology
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    • v.45 no.4
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    • pp.473-477
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    • 2013
  • The aim of this study was to identify the optimal ingredient-mixing ratio of Job's-tear and wheat flour subjected to extrusion. A modified distance-based mixture design analysis was chosen for the experimental design. The results showed that the bending failure force, the a-value, and the water absorbtion index (WAI) value had no correlation with the mixture ratio of Job's-tear and wheat flour. However, the diameter of the extrudates, the L- and b-values, and the water solubility index (WSI) value were all found to be correlated to the mixture ratio. While the first three values were determined using a linear model, the WSI value was determined using a quadratic model. The diameter and color had an inverse correlation to the mixture ratio: the higher the ratio of Job's-tear to wheat flour, the lower the diameter and darker the color. The L- and b-values were found to change in accordance with the mixture ratio of Job's-tear to wheat flour. The lowest WSI value was obtained at a 40:60 ratio of Job's-tear to wheat.

Prediction of Parthenogenetic Developmental Potential by Polar Body Extrusion and First Cleavage on In Vitro Maturation and Development of Porcine Follicular Oocytes (돼지 난모 세포의 Ethanol 처리에 의한 단위 발생에 있어서 극체 방출란과 분할란 선별에 따른 배발달율 비교)

  • Kim, H.J.;Cho, S.R.;Choe, J.Y.;Choi, S.H.;Han, M.H.;Son, D.S.;Lee, S.S.;Sang, B.D.;Ryu, I.S.;Kim, I.C.;Kim, S.J.;Kim, I.H.;Kim, S.K.
    • Journal of Embryo Transfer
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    • v.22 no.2
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    • pp.121-126
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    • 2007
  • The objective of this study was carried out to examine the selection effects of in vitro matured porcine follicular oocytes with polar body extrusion and early cleavage as non-invasive marker to know the developmental competence in advance. The porcine oocytes matured for 48 h were examined the polar body extrusion. The examined oocytes were matured for additional $16{\sim}18h$ and activated with 7% ethanol and cultured in $5{\mu}g/ml$ cytochalasin B for 5 h for diploid formation. The treated oocytes were cultured and examined the cleavage after 48 h and continued culturing for 5 days. The oocytes of 21.9% were discarded in morphological selection and 32.1% oocytes were discarded by failure of first polar body extrusion. The selected oocytes were matured and activated and then after 48 h the cleavage rates were examined. In morphologically selected oocytes, 15.8% oocytes were not cleaved and 52.6% oocytes were normally cleaved and 31.6% oocytes were hyper-cleaved over 8-cell stage. However in the first polar body extruded oocytes, 7.1% oocytes were not cleaved and 73.1% oocytes were normally cleaved and 19.8% oocytes were hyper-cleaved. The morphologically selected embryos that not cleavage-selected were developed in 16.7% up to blastocyst and the morphologically selected and cleavage-selected embryos were developed in 31.7%. The polar body extruded oocytes that were not carried out cleavage selection were developed in 39.0% and the polar body extruded and cleavage-selected embryos were developed 49.0%. The first cleavage timing was examined with 12 h interval after activation. In $0{\sim}12,\;12{\sim}24,\;24{\sim}36,\;and\;36{\sim}48h$ intervals, 4.1%, 68.6%, 19.1%, and 2.3% oocytes were cleaved and 5.9% oocytes were not cleaved until 48 after activation. The cleaved oocytes in each interval were cultured and developed upto blastocyst with 0, 39.1, 9.5, and 0%, respectively. This results suggests that polar body extruded and cleaved at $12{\sim}36h$ embryo has higher developmental potential than the others.

Finite Element Analysis on the Sealing Behavior and Endurance Safety of O-rings with a V-groove (V홈을 갖는 오링의 밀봉거동과 내구 안전성에 관한 유한요소해석)

  • Kim, Chung Kyun
    • Journal of the Korean Institute of Gas
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    • v.17 no.1
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    • pp.73-80
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    • 2013
  • This study presents sealing behavior and endurance safety of V-grooved o-rings as functions of a strain, compression stress, and contact normal stress using a FEM technique. The FEM results on the sealing behavior and endurance safety show that the maximum strain, maximum compression stress, and maximum contact normal stress of V-grooved o-rings are approximately 1.2 times higher than those of conventional solid o-rings. This is why that an o-ring has a V-groove in the center between two overlapped circles, which is very effective in sealing for ball valves, pressure vessels, and gas equipment. And the extrusion failure in V-grooved o-rings does not take place under an increased gas pressure due to a V-groove. This may extend sealing life compared with that of a conventional solid o-ring.

Experimental Investigation on Cracks and Defects of a Valve Sealing Components for a LPG Cylinder (LPG 용기용 밸브의 밀봉부품 크랙 및 결함에 관한 실험적 고찰)

  • Kim, Chung-Kyun;Lee, Byung-Kwan;Kim, Tae-Hwan
    • Journal of the Korean Institute of Gas
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    • v.11 no.1 s.34
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    • pp.23-28
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    • 2007
  • This paper presents an experimental investigation on the sealing defects and cracks of O-rings and a valve packing of a gas valve for a LPG cylinder. O-ring in which stops a gas leakage of a liquefied petroleum gas is very important for a LPG valve safety. Valve packing is to open and close a gas flow port for supplying and charging a LPG fuel. The sealing performance of two sealing units ism related to the leak safety and long lift of a gas valve. The investigated results show that most of O-rings was failed due to a circumferential crack in which is caused by partial press bonding failure near the partition zone and an excess compression rate. Some of the O-ring failure was originated by an extrusion of an excessive leak pressure of a LP gas. Thus, this paper strongly recommends a tight quality control and a safety guarantee system of O-rings and valve packing to guarantee a leak safety and to extend a service lift of a gas valve. At the end, a warranty policy of the sealing units should be adopted for increasing a product quality and safety of a gas valve.

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Clinical evaluation of a new extraction method for intentional replantation (의도적 재식술을 위한 새로운 발치법의 임상 평가)

  • Choi, Yong-Hoon;Bae, Ji-Hyun
    • Restorative Dentistry and Endodontics
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    • v.36 no.3
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    • pp.211-218
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    • 2011
  • Purpose: Intentional replantation (IR) is a suitable treatment option when nonsurgical retreatment and periradicular surgery are unfeasible. For successful IR, fracture-free safe extraction is crucial step. Recently, a new extraction method of atraumatic safe extraction (ASE) for IR has been introduced. Patients and Methods: Ninety-six patients with the following conditions who underwent IR at the Department of Conservative Dentistry, Seoul National University Bundang Hospital, in 2010 were enrolled in this study: failed nonsurgical retreatment and periradicular surgery not recommended because of anatomical limitations or when rejected by the patient. Preoperative orthodontic extrusive force was applied for 2-3 weeks to increase mobility and periodontal ligament volume. A Physics Forceps was used for extraction and the success rate of ASE was assessed. Results: Ninety-six premolars and molars were treated by IR. The complete success rate (no crown and root fracture) was 93% (n = 89); the limited success rates because of partial root tip fracture and partial osteotomy were 2% (n = 2) and 5% (n = 5), respectively. The clinical and overall success rates of ASE were 95% and 100%, respectively; no failure was observed. Conclusions: ASE can be regarded as a reproducible, predictable method of extraction for IR.

Production of Extrudates Formulated from Pacific Sand Lance Sauce By-Product and Dried Biji (까나리 액젓 부산물과 건조 비지를 첨가한 압출성형물의 제조)

  • Han, Gyu-Hong;Kim, Byung-Yong;Lee, Jae-Kwon
    • Korean Journal of Food Science and Technology
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    • v.34 no.2
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    • pp.186-193
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    • 2002
  • This study was conducted to enhance the protein quality of wheat flour extrudates with the addition of fish sauce by-products and dried biji. The experimental design was used to determine the optimum ratio of each ingredient. The compositional and functional properties of test extrudate were measured, and these values were applied to the mathematical models. A canonical form and trace plot showed that the influence of each ingredient on the mixture final product. Protein content of extrudate was increased by the addition of the dried biji, and bending failure stress of extrudate became hardened due to interaction effects between dried biji and pacific sand lance sauce by-product. Also, the addition of dried biji decreased ash and salt contents. An optimum formulation was obtained as 15.83 : 44.17 : 40% with numerical and 15.74 : 44.26 : 26.40% with graphical method (pacific sand lance sauce by-product : dried biji : wheat flour). Based on the growth performance, feed conversion efficiency was slightly lower than control group, but the protein content in feed extrudate increased to a large extent compared to that mixed with wet biji.

Orthodontic protraction of the third molars to the posterior teeth missing area (구치 결손 환자에서 제3대구치의 교정적 활용)

  • Lee, Kang-gyu;Park, Je-Hyeok;Jeon, Jin;Kang, Jae-yoen;Kim, Jong Ghee;Jeon, Young-Mi
    • Journal of Dental Rehabilitation and Applied Science
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    • v.35 no.4
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    • pp.260-269
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    • 2019
  • The prolonged neglect of the posterior teeth missing area may cause mesial drift, extrusion, unexpected movement of the adjacent teeth and alveolar bone loss with occlusion collapse. Therefore it is recommended to treat that area by the prosthesis as soon as possible after tooth missing. However, if orthodontic treatment is applied to move the remained teeth, it can create improved biomechanical dentoalveolar environment. The use of the third molars in teeth missing area provides advantages as optimizing of prosthesis size. However, crown shape, location, soundness of the third molar and possible of eruption failure should be considered. In this case report, two patients closed a second teeth missing site and reduced the size of the first and second teeth missing area for an implant by protraction of impacted third molars. This case reports the considerations for closing or reducing the posterior teeth space with protracting the third molars by comparing two patients.