Numerical Study of Die Design for PVC Foam Extrusion

Nafiz Ahmed Badhan,김시조 한국유변학회 2021 Korea-Australia rheology journal Vol.33 No.3

Bubble growth inside the die is one of the critical issues in the PVC foam extrusion process. Burning and clogging might have occurred when bubble growth exceeds the critical size, leading to non-uniform outlet velocity and pressure profile inside the die. Therefore, a design modification for die geometry is necessary. This study aims to suppress the bubble generation by making the pressure inside the die greater than the bubble nucleation pressure and to make the velocity distribution uniform at the die exit. A new concept of adding choker bars inside different dies (namely, T-die, fishtail die, and coat-hanger die) is proposed. Three choker bars consecutively placed one after another inside the dies slit sections were numerically simulated to observe and discuss the effects of the proposed geometric shape on the outlet velocity profile in the nonisothermal generalized Newtonian flow. The results show that the velocity distributions at the exit of the die were nearly uniform in all three dies. Among the dies, the fishtail die shows the best outlet velocity uniformity. The pressure values inside all dies are found to be higher than the nucleation pressure except at the last 0.5 mm near the die outlet. This confirmed that the bubble growth could only begin near the 0.5 mm die outlet region in all dies.

EPOXY RESIN의 정확도와 인상재와의 친화성에 관한 연구

장수경,장익태,임순호,Chang, Su-Kyoung,Chang, Ik-Tae,Yim, Soon-Ho 대한치과보철학회 1999 대한치과보철학회지 Vol.37 No.3

The indirect technique for making cast restoration requires that dies be as accurate and durable as possible. Currently, stone is the most commonly used material for die. However, it has some problems such as the weakness in its strength and low abrasion resistance. Recently, epoxy resin die systems have become available. The purpose of this study was to examine two commercially available resin die systems and evaluate some characteristics for their clinical performance. This study evaluated the dimensional accuracy of epoxy resins and their wettability with impression materials. In this study, the first experiment was about dimensional accuracy of different die materials. The master model was made of stainless steel. 10 models were made of two epoxy resins (Die-epoxy, Tri-epoxy) and a die stone (Fujirock) each. Occlusal diameter (Dimension I), occluso-gingival height (Dimension II), and interabutment distance (Dimension III) were measured in each model. Next, the contact angles of die materials with impression materials were observed. The blocks were made of polyether, hydrophilic additional silicone, polysulfide impression materials. By drop-ping the same amount (0.05ml) of Tri-epoxy, Die-epoxy, and die stone on the blocks, 10 samples of each die material were made. After setting of materials, the contact angles were measured. The results of this study were as follows. 1. The expansion of stone die and the shrinkage of resin dies in occlusal diameter were observed, and stone and Tri-epoxy were expanded and Die-epoxy was shrinked in occluso-gingival height. There was little change among materials in interabutment distance (p<0.05). 2. In comparison with the master model Tri-epoxy had the least variation in measurement of the three die systems examined. Die-epoxy was next, and die stone showed the greatest variation. 3. The compatibility of die stone for polyether, hydrophilic additional silicone, polysulfide decreased in order, wherease epoxy materials had the decreased compatibility for polyether and polysulnde, hydrophilic additional silicone in order. It was not statistically different between polyether and polysulfide (p<0.05). 4. The contact angles of Tri-epoxy, Die-epoxy, die stone were getting bigger in order.

정보의 웰-다잉(Well-dying)을 위한 입법론적 검토

이경규(Lee, Kyung Gyu),안세훈(An, Se Hoon) 한국정보법학회 2014 정보법학 Vol.18 No.3

인류의 역사는 ‘자유 신장을 위한 전쟁’이라 단언해도 좋을 만큼, 자유는 인류에게 중요한 가치이다. 그러나 스마트폰의 출현으로 어디서든 인터넷 접속이 가능한 유비쿼터스 시대가 도래하였고, 인간의 편의를 위해 발전된 정보통신기술로 인해 장구한 역사 속에서 인류가 피 흘리며 쌓아온 자유가 침해되고 있다. 이미 빅데이터에 대해 사람들은 두려움을 느끼고 있으며, 메시지를 보내는 사람이 수신자가 1∼10초내 메시지를 볼 수 있도록 제한한 ‘스냅챗’까지 등장하였다. 2014년 5월 이런 현실을 인식한 ECJ이 판결이 등장하였다. 이미 온라인서비스제공자의 정책, 각 국의 법에 알게 모르게 ‘잊힐 권리’가 녹아들어 있음에도 불구하고 ‘잊힐 권리’가 논의된 첫 판결이라는 점에서 이번 ECJ 판결의 의의가 크다. 많은 나라가 ‘잊힐 권리’의 필요성을 인정하면서도 이를 명시적으로 인정하지 않는 이유는 정보를 어떻게 통제하며, 누가 통제권을 행사할 것인지, 어떻게 행사할 것인지 등의 많은 문제들이 산재되어 있기 때문이다. 즉 ‘정보의 Well-dying’이 우리의 발목을 잡고 있는 것이다. 이에 본 논문에서는 ECJ판결과 우리나라의 관련 현행법을 간략히 살펴본 후, ‘잊힐 권리’와 함께 ‘정보를 어떻게 Well-dying시킬 것인지’를 정보유형별로 나누어 논의하겠다. ‘잊힐 권리’를 포괄적으로 인정하게 되면 인류의 중요 가치인 자유가 과도하게 침해될 뿐만 아니라, 정보의 성격에 따라 ‘잊힐 권리’의 행사가 차별적으로 인정되는것이 타당하기 때문이다. 그러므로 ‘잊힐 권리’ 행사여부에 초점을 맞추기 보다는, 정보유형을 나눈 후 이에 따라 개별적으로 판단하여 ‘정보의 Well-dying’을 위한 입법적⋅ 기술적 해결방안을 논의하겠다. 정보의 Well-dying문제는 누가 정보통제권을 행사할수 있는지, 어느 정도의 범위까지 인정할 것인지, 현재 기술 및 자치적 규정으로 해결 가능한지 여부 등에 관한 것으로 정보의 Well-dying에 대한 논의가 선행되어야 ‘잊힐권리’가 실질적으로 행사될 수 있다. 현 ECJ판결도 ‘잊힐 권리’를 전면적으로 인정하지 않은 데에는 현재 구체적 개념, 근거, 내용 및 한계가 불명확한바 현실적으로 도입하기에 많은 문제가 있음을 인식한 결과이다. 그러므로 규제자의 책임성이 새로운 사회적 문제가 될 수 있음을 인식하고 이를 견제하기 위하여 우리에게 가장 중요한 가치가 무엇인지를 상기하며, 이러한 구체적인 정보의 유형에 따라 삭제권 인정여부를 법제화 한다면 ‘정보의 Well-dying’과 함께 잊힐 권리와 관련된 문제들을 보다 합리적이고 명확하게 해결할 수 있을 것이다. As affirmed in the human history, Freedom is of very much importance; in the ubiquitous era, however, human rights and liberty are paradoxically threatened by the advanced information and communication technologies for the convenience of human beings; and for fear of big data abuses, people need a defensive application, such as ‘Snapchat’ where a message recipients are allowed only 1 to 10 seconds to see it. Under this climate, there comes a recent judgement of ECJ, the first case on the ‘right to be forgotten’. While many countries recognize the needs for a ‘right to be forgotten’, yet does not acknowledge it explicitly, there are many problems not to be solved, such as how to control the information; who and how to exercise control; in other words, the ‘Well-dying of information’. In this paper, after briefly discussed the current laws and the relevant judgement of ECJ, some legal aspects of the ‘right to be forgotten’ will be discussed; dividing the information type and how the information well die. The ‘right to be forgotten should be recognized as limited and discriminatory depending on the type of the information, rather than comprehensive right; therefore, we discuss the legislative and technological solutions for the’ Well-dying of information’ at each type of information divided by the subjects and controller of the informations; that are, who can exercise control over the information, whether to admit the extent of the degree, the current technology and autonomous regulation to resolve the debate about the ‘Well-dying of information’. Recent ECJ ruling also does not accept the ‘right to be forgotten’ as a comprehensive right; because the concept, legal basis, scope and limitation of the ‘right to be forgotten’ is not clear and much to be left for future discussion. Therefore, it should be appreciated that the responsibility of the information controller and regulation thereon; the legislation associated with the ‘Well-dying of information’ and ‘right to be forgotten’ based on the type of specific information will be able to clearly resolve the problems.

구약성경의 웰 다잉(Well Dying)의 원리에 관한 연구

김남일 ( Nam Il Kim ) 개혁주의생명신학회 2016 생명과 말씀 Vol.16 No.-

안락사에 대한 세계 각국의 논쟁을 뜨겁다 못해 경쟁적이기까지 하다. 2014년 벨기에가 18세 미만의 미성년자들에 대한 안락사를 법으로 허용한 이래 세계 각국들은 안락사에 대한 논쟁에 불을 붙였다. 우리나라도 소극적 안락사를 법적으로 허용하는 나라가 되었는데(2016년 1월 8일) 이는 소극적 안락사로 인해서 발생할 수 있는 의료권의 남용이나, 환자 선택권의 오용을 불러올 수 있는 것과 마찬가지라고 생각한다. 이에 필자는 안락사를 찬성하고 진보적으로 발전시키려고 하는 시대에 영향을 받는 그리스도인들을 향해서 성경적 웰 다잉이 과연 무엇인지, 그 원리는 무엇인지, 그리고 구약성경에서 웰 다잉을 하고 죽은 사람들을 소개하려고 한다. 이를 위해서 안락사에 대한 간략한 서술을 한 후 구약성경이 생명과 고통, 죽음에 대해서 어떤 시각으로 다루고 있는지를 살펴보았다. 또한 많은 고통 가운데서도 고통의 영적인 의미를 발견하고 평안한 죽음을 맞이했던 네명의 사람을 소개함으로 진정한 웰 다잉이란 고통의 시간을 줄이기 위해서 나의 생명을 내 마음대로 죽이는 것이 아니라 하나님 안에서 고통과 죽음의 의미를 받아들이면서 주어진 삶을 최선을 다해서 살다가 하나님 안에서 죽는 것임을 강조하였다. An argument on the Well Dying of the whole world are getting hotter and competitive. Since Belgium permitted the law for the well dying for under 18 age, many nations are getting participate to this argument. Korea also one of the permitted the adult well dying(passive) in the world(2016, 1, 8), it means we have a possibility to argue about the proceeding into the positive well dying. For example, mis(wrong)-using of the medical rights, choosing rights of the patients and it will be a cause of more serious ethical arguments. In this time, I would like to propose the biblical conception on the well dying in the Old Testament to all christian those who is getting influencer from the out of biblical sources include a few sample characters in the Bible. In chapter I described on the argument which are happening in the world. And in chapter 2, I introduced briefly about the well dying with a few arguments. In chapter 3, I tried to introduce about the conception of the life, pain and the death according to the OT standpoint. And in chapter 4, I mentioned on the well dying persons Abraham, Isaac, Joseph and king David. Ot is full of well died persons story. And finally in chapter 5, I made a conclusion on this article. This article is not focused on agreement or not to the well dying but focused on the conditions for the well dying based on the OT. Therefore it has a limitation like agreement or disagreement to the well dying. Rather I tried to survey the principals for the well dying according to the OT. True well dying is just not only choose problem but enjoy myself in God.

청소년의 민주시민성 교육을 위한 DIE-논쟁 학습 모형의 개발과 그 효과에 관한 연구

구민정,권재원 한국사회과교육연구학회 2007 사회과교육 Vol.46 No.2

A Study on Developing DIE-Debate Class Model and its Effect on Adolescent's Democratic Citizenship Jae Won, Kwon(Kodeok Middle School), Min Jung, Koo(Kangil Middle School) This study is about developing DIE-Debate Class model and experiment to test its effect on adolescent's democratic citizenship. To consolidate Democracy in Korea, the education to enlarge democratic citizenship of adolescents is very important. The debate class model has been recommended as the best class model for this purpose. But there have been several problems make it difficult to apply debate class in Korean classroom. DIE can fix these problems through supplying virtual experience to students and motivate their interest using Drama. In this study authors developed DIE-debate class model that combinate debate class and DIE, using debate as Follow up of DIE and operated an experiment to verify its effects on adolescents' democratic citizenship. The result is that DIE-debate class was more effective than debate class in fostering adolescents' democratic citizenship. 이 연구는 DIE-논쟁 학습 모형의 개발과 이것의 청소년의 민주시민성 교육에 미치는 효과를 검증하기 위한 실험이다. 한국 민주주의의 공고화를 위해 청소년의 민주시민성 교육은 매우 중요하다. 논쟁학습은 이를 위한 좋은 도구로 권장되었다. 그러나 이것의 적용을 어렵게 만드는 한국 교실 고유의 문제들이 있다. DIE는 연극을 이용하여 학생들의 흥미를 유발하고 가상의 체험을 제공하여 이 문제를 보완할 수 있다. 이에 이 연구에서는 DIE의 팔로우업 단계에 논쟁학습을 결합한 DIE-논쟁학습 모형을 개발하고 그 효과를 검정하기 위해 실험을 실시하였다. 240명의 청소년을 표본으로 실시한 실험결과 DIE-논쟁학습이 논쟁학습보다 청소년의 민주시민성 향상에 더 큰 효과를 보이는 것으로 나타났다.

Numerical Simulation of Die Characteristics for Different Dies in Film Casting Extrusion Processes

( Ju Hyun Kim ),( See Jo Kim ) 한국고무학회 2020 엘라스토머 및 콤포지트 Vol.55 No.4

In this study, three different die geometries were selected to understand the die characteristics in the film casting extrusion processes. First, large and small-scale T-dies were numerically simulated to observe the scaled-down effect on the flow inside the dies. Second, three different dies-keyhole, linear tapper coat-hanger die (LTCD), and curved tapper coathanger die (CTCD)-were numerically observed and discussed according to the mass flow rate. Finally, the die exit velocity profiles and die characteristics were observed and discussed based on the power-law index for the LTCD die. These numerical simulations and numerical data will aid the optimization of the die design in industrial fields.

형벌법규에 대한 위헌결정의 효력을 둘러싼 쟁점 ― 위헌결정의 소급효제한과 그 제한시점을 중심으로 ―

남복현 한국공법학회 2014 공법연구 Vol.43 No.1

Das Koreanische Parlament hat am 20. Mai 2014 § 47 II ff. KVerfGG geändert, so dass die Rechtsfolge von der Verfassungswidrigkeitsentscheidung über die Bestimmungen, die die Strafe im Sinne des Strafrechts auferlegt, eingeschränkt wird, insb. ueber die Einschränkung der Rückwirkung und ihren hinaufzugehenden Zeitpunkten. Wenn es eine solche Bestimmung fuer verfassungswidrig erklärt hatte, bedeutete die Nichtigkeit ihrer Wirkung als Rechtsfolge prinzipiell ganz rückwirkend. Aber nach der Änderung des KVerfGG, ist es anders geworden: wenn das Verfassungsgericht eine Bestimmung für verfassungswidrig erklärt, wird ihre Wirkung grundsätzlich rückwirkend vernichtigt, dennoch mit der Ausnahme: wenn es im Gegensatz dazu schon einmal sie fuer verfassungsmässig erklaert hatte, wird die Wirkung jetziger Verfassungswidrigentscheidung nur bis zum nächsten Tag der vorherigen Entscheidung rückwirkend vernichtet. Es liegt daran, dass die Nebenwirkung nicht so leicht oder einfach wäre, wenn man nur das Prinzip bzw. die rückwirkend Vernichtung ohne weiteres angenommen wuerde wie früher. Um den Sinn der Änderung dieses KVerfG richtig zu erfassen, soll man sie unter dem Gesichtpunkt von den Beziehungen zwischen zwei Klagen betrachten. Dabei soll eine Verfassungsmässigkeitsentscheidung in der vorigen Klage gefallen sein, und der Klaeger in der späteren bzw. nachfolgenden Klage den Prozess gewinnen (natürlich auch in der verschiedenen Form wie Verfassungswidrig-, Unvereinbar-, Soweit-verfassungswidrig- oder Soweit-verfassungsmässigkeitsentscheidung). Noch eine Bedingung kommt hinzu: der Prüfungsgegenstand in der vorigen Klage und der nachfolgenden soll als das Gleiche bewertet werden koennen. Erst danach kann die neu geänderte Bestimmung des KVerfGG angewendet werden. Der Zweck dieser Änderung des KVerfGG liegt darin, die Rechtssicherheit bzw. die alte, also durch die vorige, als verfassungsmässig schon erklärte Entscheidung etablierte Ordnung soweit zu erhalten. Die Änderung dieses Gesetzes dient in der Zukunft auch dazu, die Verfassungsgerichtstätigkeit viel lebendiger als bisher zu machen. Früher hat sich das KVerfG vor den Verfassungswidrigentscheidungen immer zurückhaltend oder davon ausweichend bewegen. Dennoch kann es jetzt bzw. nach dieser Änderung etwa aktiver als früher werden, weil es dem KVerfG nicht mehr braucht, vor den alten, voll rückwirkenden Wirkungen dieser Art von den Verfassungswidrigentscheidungen zu fuerchten. Dem KVerfG ist solche Last zur Zeit schliesslich vom Herzen genommen. Aber noch ungelöst bleiben einige Problemen, wie weit die Rückwirkung erschliessen wuerde, ob sie nur auf den Fällen der vorigen Verfassungsmässigkeitsentscheidungen eingeschränkt werden sollte, und ob auch die Umstände ins Betracht gebracht werden sollte, dass die/der Beklagte schon nach der als schuldhaft verurteilten Entscheidung unter dem Vollzug steht. Und zwar wird jede Bedürftigkeit nach den Unvereinbarentscheidungen nach der Änderung auf keinen Fall erschöpft. Schliesslich wird dem Verfassungsgericht noch insoweit es eingeräumt, wie es die Entscheidungsvariante anders als bisher weiter gestalten werden sollte. 우리 국회는 지난 2014. 5. 20. 형벌법규에 대한 위헌결정의 소급효를 제한하는 것과 관련해서 헌재법 제47조 제2항 이하를 개정하였다. 종래에는 형벌법규에 대해 위헌결정이 선고되면 소급적으로 그 효력이 상실되는 것으로 규정하였다. 그런데 개정법률은 형벌법규가 위헌결정되면, 원칙적으로는 소급적으로 그 효력이 상실되지만, 종전에 합헌결정이 있었을 경우에는 그 결정이 있은 다음 날까지만 소급하여 효력을 상실하는 것으로 규정하였다. 종전에는 합헌으로 결정하였으나 나중 사건에서 위헌으로 결정하였을 경우에도 심판대상인 법률조항이 그 제정(내지 개정)시점에 획일적으로 소급하여 효력을 상실하도록 하는 것은 부작용이 적지 않다는 지적에 반응한 것이었다. 이번의 개정입법을 이해하려면, 전소와 후소의 관계라는 시각에서 접근해야 한다. 전소에서는 합헌결정이 이루어졌어야만 하고, 후소에서는 청구인용 형태의 결정(위헌결정, 헌법불합치결정, 한정위헌결정, 한정합헌결정)이 이루어졌어야 한다. 또한 이번의 개정입법이 적용되기 위해서는 전소와 후소의 관계에 있어 심판대상의 동일성이 인정되어야 한다. 동일성이 인정되지 않으면 이 개정입법이 적용되지 아니한다. 이번의 개정입법은 법적 안정성을 확보하고 종래의 합헌결정으로 만들어진 질서를 존중한다는 의미를 지니기도 한다. 그런가 하면 이번의 개정입법은 헌법재판의 활성화에도 기여할 것이다. 형벌법규의 위헌결정이 지닌 소급효로 인해 그 결정이 미칠 파급효과가 우려되어, 실체적 형벌법규에 대한 위헌결정이 회피되었거나 변형결정이 적극 활용되었음은 부인할 수 없음이 종래 우리 헌재 결정의 실제이었다. 그런 부담을 대폭 완화하였다는 점이다. 이번 개정입법의 문제점으로는 소급효의 제한범위를 둘러싼 논란의 여지, 종전에 합헌결정이 있었던 경우만으로 한정한 점, 유죄의 확정판결이 집행중인지의 여부를 고려하지 않은 점 등이다. 그리고 위헌결정의 소급효를 제한하는 입법이 마련되었다고 해서 형벌법규에 대한 헌법불합치결정의 필요성이 완벽하게 해소된 것은 아니다. 게다가 헌법재판소가 달리 정할 필요성이 완전하게 없어진 것도 아니다.

카테터 튜빙 압출에서 다이의 형상에 따른 고분자 용융체의 흐름특성

조한수,류민영 한국고분자학회 2018 폴리머 Vol.42 No.2

The plastic tubing in catheter is manufactured by extrusion. In this study, computer simulation was performed and results were compared for two types of dies, specifically, straight die and crosshead die for the extrusion of catheter tubing. A spider leg supports the mandrel in the straight die and this die is attached to the extruder in the same line. For the crosshead die, mandrel contains helical grooves and the die is attached to the extruder at an angle of 90o. The pressure, velocity, streamline, wall shear stress, and residence time in the two types of dies were analyzed and compared through computer simulation. The velocity difference in the die land region where the size of catheter tubing is determined between the two types of dies was large whereas the pressure drops in the two dies were similar. A complex flow pattern was observed in the crosshead die and subsequently, the residence time in the crosshead die was three times longer that of the straight die. Wall shear stress in the crosshead die was much smaller than that of the straight die. Thus, more stable extrusion of catheter tubing is expected for the crosshead die.

전조가공 방식의 Worm Roll Cylindrical Dies의 소재특성 및 절삭성에 관한 연구

崔昌燮 弘益大學校 産業技術硏究所 2007 産業技術 Vol.17 No.-

The purpose of this study is research into and develop the component rolling dies the primary processmg tool to produce precise and reliable which must be on of the core parts of motor Study for the strength plan and the life improvement of the Dies, use and fatigue life of Dies element about Form Rolling Cylindrical Dies of worms and for naterial and manufacturing technique of dies elements. Form Rolling Dies or produce the products ensured an accuracy and a trust of shaft main part of motor. In Research and Development, Studied about the shaft of automobile motors and the Form Rolling Dies of worms and for the material and the manufacturing technique the use and fatigue life of Dies elements, life improvement of Dies. SKDll or other alloy steel materials for dies to be cold working were tested to examine. life characteristics. These materials were subject to wearing and fatigue tests to examine their life. Local dies products were examined for materials, hardness and shapes depending on their manufacturing. Heat treatment, composition and mechanic properties of the materials The cutting property of worm dies material was exarnined.

The Processing Technology of Soy Protein Meat Analog Using Twin-Screw Extruder - Heat Transfer Analysis of Cooling Die -

Lee G.H. Korean Society for Agricultural Machinery 2005 Agricultural and Biosystems Engineering Vol.6 No.1

Soy protein meat analog was produced using a twin-screw extruder attached with a cooling die. Heat transfer analysis was performed for cooling dies with various die sizes at the four different moisture contents of feed during extrusion process. The experimental design consisted of two cooling die widths (30 and 60 mm), three cooling die lengths (100, 200, and 300 mm), four product moisture contents (71.2, 67.0, 61.6 and 55.8%), and water and water plus ethylene glycol as cooling material. When water was used as cooling medium, the values of equivalent overall heat transfer coefficient $(U_e)$ for each die width of 30 and 60 mm were in the range of 187.0 - 341.4 and $358.5-191.6W/m^2^{\circ}C$ depending on the size of die length. Convective heat transfer coefficients between cooling water and inside die wall of cooling channel $(h_c)$ for both die widths of 30 and 60 mm were 588.5, 416.1, and $339.8W/m^2^{\circ}C$ for each die length of 100, 200, and 300 mm. Convective heat transfer coefficients between product and inside die wall of product channel $(h_p)$ for each die width of 30 and 60 mm were in the range of $434.6-888.1W/m^2^{\circ}C$ and $460.7-1014.5W/m^2^{\circ}C$ depending on the size of die length. When water plus ethylene glycol was used as cooling medium, the values of $U_e$ were in the range of $143.9-319.6W/m^2^{\circ}C$ and $177.8-332.7W/m^2^{\circ}C$ for each die width of 30 and 60 mm depending on the size of die length.