• Title/Summary/Keyword: squeezing

Search Result 134, Processing Time 0.021 seconds

Effect of Molding Parameters on Viscosity of Unidirectional Fiber Reinforced Plastic Composites (일방향 섬유강화 플라스틱 복합재의 점도에 미치는 성형인자의 영향)

  • 조선형;안종윤;윤성운
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.9 no.6
    • /
    • pp.41-48
    • /
    • 2000
  • The Compression molding process is widely used in the automotive industry to produce parts that are large, thin, light-weight, strong and stiff. Compression molded parts are formed by squeezing a glass fiber reinforced polypropylene sheet, known a glass mat thermoplastic(GMT), between two heated cavity surfaces. In this study, the anisotropic viscosity of the Unidirectional Fiber-Reinforced Plastic Composites is measured using the parallel plastometer and the composites is treated as an incompressible Newtonian fluid. The effects of molding parameter and fiber contents ratio on longitudinal/transverse viscosity are also discussed.

  • PDF

Effect of Pressure and Initial Polymer Resist Thickness on Low Temperature Nanoimprint Lithography (저온 나노임프린트 공정에서 압력과 폴리머 레지스트 초기 두께의 영향)

  • Kim, Nam-Woong;Kim, Kug-Weon;Sin, Hyo-Chol
    • Transactions of the Korean Society of Machine Tool Engineers
    • /
    • v.18 no.1
    • /
    • pp.68-75
    • /
    • 2009
  • A major disadvantage of thermal nanoimprint lithography(NIL) is the thermal cycle, that is, heating over glass transition temperature and then cooling below it, which requires a significant amount of processing time and limits the throughput. One of the methods to overcome this disadvantage is to make the processing temperature lower Accordingly, it is necessary to determine the effects on the processing parameters for thermal NIL at reduced temperatures and to optimize the parameters. This starts with a clear understanding of polymer material behavior during the NIL process. In this work, the squeezing and filling of thin polymer films into nanocavities during the low temperature thermal NIL have been investigated based upon a two-dimensional viscoelastic finite element analysis in order to understand how the process conditions affect a pattern quality; Pressure and initial polymer resist thickness dependency of cavity filling behaviors has been investigated.

Analytical and experimental postbuckling of conditioned cables

  • Rivierre, L.;Polit, O.;Billoet, J.L.
    • Structural Engineering and Mechanics
    • /
    • v.12 no.6
    • /
    • pp.595-614
    • /
    • 2001
  • This paper studies the behaviour of a homogeneous cable in a horizontal rigid duct and loaded by an axial compressive force. This behaviour is characterized by spatial buckling modes, named sinusoidal and helical, due to friction and total or partial cable locking. The evaluation of critical buckling loads involved by drilling technology has been studied by many authors. This work presents a new formulation, taking the friction effects into account, for the transmission of the axial load during the postbuckling process. New analytical expressions of pitches in both buckling cases are also given. A life-sized bench is presented, which permits to study the laying of optical fiber cables by squeezing them into an underground duct. Finally, analytical solutions are compared with experimental tests and finite element simulations.

The Study of Drilling Technology and Field Cases for Preventing A Lost Circulation in Fractured Reservoirs (균열저류층에서 이수손실방지를 위한 시추기술 및 현장사례 연구)

  • Kim, Hyun Tae;Hong, Si Chan;Yoon, Jae Pil;Park, Yong Chan
    • Economic and Environmental Geology
    • /
    • v.49 no.1
    • /
    • pp.63-75
    • /
    • 2016
  • The ratio of fractured reservoir is very high in oil & gas fields around the world. The demand of drilling technology for fractured reservoir is expected to increase continuously if oil and gas prices are economical. The purpose of the review study is to help operator or driller in selecting of proper drilling technology for preventing a lost circulation in the fractured formation. In order to achieve this goal, fractured reservoir(formation) they are classified into partial lost circulation formation and total lost circulation formation. In case of partial lost circulation formation, the drilling problem can be solved by using LCM(lost circulation material) mud additive and squeezing cement. For shallow depth, total lost circulation formation can be drilled safely and economically with casing drilling method. Also, for deeper depth, problems of total lost circulation in formation can be solved by applying mud cap, which is one of the drilling methods. This was confirmed through field application such as Italy's Medusa-1 field and Qatar's North field.

An improved case by operating the traditional oriental medical remedy with mindfullness to the Hwa-Byung patient suffering from insomnia and physical symptoms (불면(不眠)과 신체증상(身體症狀)을 호소하는 화병 환자에게 한의학적(韓醫學的) 치료(治療)와 마음챙김명상을 병행하여 호전된 1례)

  • Park, Se-Hwan;Seok, Seon-Hee;Kim, Geun-Woo;Koo, Byung-Soo
    • Journal of Oriental Neuropsychiatry
    • /
    • v.19 no.3
    • /
    • pp.231-244
    • /
    • 2008
  • Insomnia is one of the highest frequency neuropsychosis of neuropsychiatry patients and is primarily caused by major depressive disorder. This case study is about a remedy for a 33 year-old woman who has insomnia and intense depressed mood caused by the continuous family jar. Also, she had the feeling of squeezing her body, pouring cold water into her body, anorexia and feeling cold and hot turn and turn. I operated mindfullness with accupuncture, herb-medication and aroma theraphy. Especially, mindfullness and Gagamguibi-tang were effective for relaxation and the sound sleep in quality and quantity. According to this study, the traditional oriental medical remedy such as accupuncture, herb-medication is effective for the cure of insomnia and mindfullness fortifies the oriental medical remedy.

  • PDF

Anti-Pinch System for Power Window Based on Current Information (전류 정보 기반의 파워 윈도우용 안티핀치 시스템)

  • Wibowo, Wahyu Kunto;Jeong, S.K.;Kum, J.S.;Park, S.S.
    • Journal of Power System Engineering
    • /
    • v.16 no.1
    • /
    • pp.98-105
    • /
    • 2012
  • 안티핀치 시스템은 파워 윈도우 상승 시에 인체의 특정 부위가 창문 틈 사이에 끼여 발생하는 치명적인 사고를 방지하기 위한 안전 시스템이다. 이러한 안티핀치 시스템은 물체의 끼임을 검출하는 센서 방식에 따라 접촉식과 비접촉식 두 가지로 크게 구분된다. 본 논문에서는 접촉식의 한 방법으로 전류 정보에 의해 강화된 미국의 안전 규정 FMVSS 118-S5를 만족하는 안티핀치 시스템을 제안한다. 안티핀치 시스템에 사용된 전류 정보는 추가적인 장치의 부착 없이도 기존의 파워 윈도우용 모터 드라이브에 내장된 과전류 검출용 전류 센서를 이용하여 쉽게 얻을 수 있다. 또한 전류 정보는 물체의 끼임을 신속히 검출, 반영함으로써 안티핀치 시스템에 요구되는 반전력 저감에 기여한다. 특히, 본 논문에서는 전류의 임계값이 모터 경년 변화나 운전 조건에 따라 변동하는 문제점을 개선하기 위해 핀치 상태를 효과적으로 판정할 수 있는 자동 임계값 설정 방법을 제안한다. 마지막으로 다양한 실험 및 시험을 통해 제안된 안티핀치 시스템이 FMVSS 118-S5를 만족함을 보인다.

Management of Complex Regional Pain Syndrome Type 1 With Total Spinal Block

  • Ok, Se-Jin;Yang, Jong-Yeun;Son, Ju-Hyung;Jeong, Won-Ju;Lee, Yoon-Sook;Kim, Woon-Young;Park, Young-Cheol
    • The Korean Journal of Pain
    • /
    • v.23 no.1
    • /
    • pp.70-73
    • /
    • 2010
  • Complex regional pain syndrome (CRPS) is a painful and disabling disorder that can affect one or more extremities. Unfortunately, the knowledge concerning its natural history and mechanism is very limited and many current rationales in treatment of CRPS are mainly dependent on efficacy originated in other common conditions of neuropathic pain. Therefore, in this study, we present a case using a total spinal block (TSB) for the refractory pain management of a 16-year-old male CRPS patient, who suffered from constant stabbing and squeezing pain, with severe touch allodynia in the left upper extremity following an operation of chondroblastoma. After the TSB, the patient’s continuous and spontaneous pain became mild and the allodynia disappeared and maintained decreased for 1 month.

Quality of Chest Pain According to Causal Diseases and Description of Chest Pain in Patients with Coronary Artery Diseases in Emergency Departments (응급실을 내원한 흉통 환자의 원인질환에 따른 흉통의 질 및 관상동맥질환자의 흉통 표현)

  • Cheon, Sun Hee;Choe, Myoung Ae
    • Journal of Korean Clinical Nursing Research
    • /
    • v.14 no.3
    • /
    • pp.61-72
    • /
    • 2008
  • Purpose: The purpose was to identify quality of chest pain according to causal diseases and pain expression of patients with coronary artery diseases. Method: Participants were 1,964 patients with pain who visited the emergency department of A hospital from January to December 2006. Data were collected from nurses' and doctors' records as to causal disease, and quality and expression of chest pain. Results: Causal diseases were coronary artery diseases, non-specific chest pain, respiratory diseases, non-coronary artery heart diseases and digestive diseases in that order of frequency. Every disease except respiratory disease caused mostly dull and tract pain, but 63.7% of patients with coronary artery diseases complained of typical angina pain and 24.9% complained of atypical angina pain. Patients with coronary artery diseases mostly used word 'heaviness' in describing their dull pain, and 'squeezing' for tract pain. Both male and female patients who were diagnosed with coronary artery disease complained mostly frequently of dull pain and tract pain. Conclusion: The most common causal disease for patients with chest pain was coronary artery disease. Patients with other diseases also frequently complained of dull and tract pain, the same as patients with coronary artery diseases. A considerable number of patients complained various types of atypical angina pain in coronary artery diseases.

  • PDF

A Viscoelasitc Finite Element Analysis of Thermal Nanoimprint Lithography Process (열-나노임프린트 공정의 점탄성 유한요소해석)

  • Kim, Nam-Woong;Kim, Kug-Weon;Sin, Hyo-Chol
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.14 no.4
    • /
    • pp.1-7
    • /
    • 2007
  • Nanoimprint lithography (NIL) is an emerging technology enabling cost-effective and high-throughput nanofabrication. To successfully imprint a nano-sized pattern, the process conditions such as temperature, pressure, and time should be appropriately selected. This starts with a clear understanding of polymer material behavior during the NIL process. In this work, the squeezing of thin polymer films into nanocavities during the thermal NIL has been investigated based upon a two-dimensional viscoelastic finite element analysis in order to understand how the process conditions affect a pattern quality. The simulations have been performed within the viscoelastic plateau region and the stress relaxation effect has been taken into account.

  • PDF

Design and Analysis of Ball Screw-driven Robotic Gripper (볼 나사 구동형 로봇 그리퍼 설계 및 특성 분석)

  • Kim, Byoung-Ho
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.22 no.1
    • /
    • pp.22-27
    • /
    • 2012
  • This paper presents a ball screw-driven robotic gripper mechanism which is possible to grasp an object and analyzes its kinematic feature for grasping by simulation. For the purpose of identifying the feature of the robot gripper, we try to confirm the kinematics relating the joint space of the driving actuator to the gripper's tip space. To be specific, the proposed robot gripper employs one actuator and a symmetrical closed-chain structure. As a result, the specified robot gripper has an advantage of robustness to external forces structurally, and it is easy to implement simple grasping operations. Also the gripper has a useful squeezing effect for power grasping.