Warren D. Marcus^1,2, Rodger P. McEver³, Cheng Zhu¹

Molecular & Cellular Biomechanics, Vol.1, No.4, pp. 245-252, 2004, DOI:10.3970/mcb.2004.001.245

Abstract When a cell adhered to another cell or substratum via surface proteins is forced to detach, lipid membrane tethers are often extruded from the cell surface before the protein bond dissociates. For example, during the inflammatory reaction leukocytes roll on the surface of activated endothelial cells. The rolling adhesion is mediated by interactions of selectins with their ligands, e.g., P-selectin glycoprotein ligand (PSGL)-1, which extrudes membrane tethers from the surfaces of both leukocytes and endothelial cells. Membrane tether extrusion has been suggested to regulate leukocyte rolling. Here we examine several factors that may affect forces required to initiate membrane tethers,… More >

C.T. Kwan, C.C. Wang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.1, pp. 1-2, 2011, DOI:10.3970/icces.2011.018.001

Abstract In this paper, a pre-stress die design method for cold backward extrusion with a non simple hollow cylinder die by using response surface method is proposed. The radius of the interface and the absolute interference in the interface of a prestress die are chosen as the design variables. Both the two design variables are set at four levels, and then 16 combinations of design parameters are constituted totally. A finite element based code is utilized to investigate the elastic deformation characteristic under different design parameters, and the response surface method is then employed to synthesize the data sets obtained from… More >

L. Donati, L. Tomesani

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.1, pp. 37-38, 2009, DOI:10.3970/icces.2009.012.037

Abstract In recent years aluminum extruded hollow profiles are increasingly used in near-net shape manufacturing processes such as bending and hydroforming; in fact, by applying these secondary processes, it is possible to obtain very high complex parts, especially for the transport industry. It is known that hollow profiles obtained by direct hot extrusion necessarily have some longitudinal welding lines (so called seam welds) produced inside the die and it is common experience, during secondary forming processes, the appearance of early cracking in proximity of those lines [1,2]. At the same time, the direct hot extrusion is the only process able to… More >

Fatma Kharrat¹, Rania Chaari¹, Mohamed Khlif¹, Loic Hilliou², José A. Covas², Mohamed Haboussi^3,*, Hedi Nouri¹, Chedly Bradai¹

Journal of Renewable Materials, Vol.7, No.9, pp. 891-901, 2019, DOI:10.32604/jrm.2019.06827

Abstract Biocomposite films prepared with melt compounding and film blowing have become a new trend in plastic research to deliver more eco-friendly packages. Polylactic acid (PLA) was melt compounded with minimally processed date palm leaf fiber (DPLF) and converted into films by blown film extrusion. The compounding was done in order to enhance the film mechanical properties in one hand, and to decrease the film production cost in the other hand. In this present study, a reference PLA film and films with 1%, 2%, and 5% of DPLF (weight %) were produced with different process parameters. The spatial variations in films… More >

Meng Li¹, Kanhua Su¹, Zijian Li², Dongjie Li³, Lifu Wan¹

CMES-Computer Modeling in Engineering & Sciences, Vol.113, No.4, pp. 475-495, 2017, DOI:10.3970/cmes.2017.113.475

Abstract With the consideration of the randomness of complex geologic parameters for ultra-deep wells, an uncertainty analysis method is presented for the extrusion load on casing in ultra-deep wells through complex formation at a certain confidence level. Based on the extrusion load model for casing in ultra-deep wells and the prerequisite of integrity of formation-cement ring-casing, the probability and statistics theory is introduced and the sensitivity analysis on the uncertainty of extrusion load on casing is conducted. The distribution types of each formation parameters are determined statistically. The distribution type and distribution function of the extrusion load on casing are derived.… More >

T.W. Dong¹, H.S. Liu¹, S.L. Jiang², L.Gu¹, Q.W. Xiao¹, Z. Yu¹, X.F. Liu³

CMES-Computer Modeling in Engineering & Sciences, Vol.95, No.5, pp. 369-390, 2013, DOI:10.3970/cmes.2013.095.369

Abstract In this paper, we present a free surface flow model with a forced revolving moving boundary for partially filled screw extrusion. The incompressible smoothed particle hydrodynamics (ISPH) is used to simulate this complex flow. A set of organic glass experimental device for this partially filled fluid is manufactured. SPH results are satisfactorily compared with experiment results. The computed free surfaces are in good agreement with the free surfaces obtained from the experiment. Further analysis shows that with the increase of the speed, the average velocity of fluid increases, the effect of centrifugal force begin to show up, the maximum pressure… More >

H. Tang¹, L.C. Wrobel², Z. Fan²

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.2, pp. 129-146, 2007, DOI:10.3970/fdmp.2007.003.129

Abstract This paper presents an overview of diverse extrusion techniques and, in particular, a focused discussion about the rheoextrusion process for semi-solid casting (a novel casting process for the fabrication of high quality metals). The review reveals a wealth of interesting rheological and microstructural features, illustrating qualitative and quantitative data. The analysis is supported by relevant numerical results and examples. It is shown how numerical studies can lead to significant insights into these processes by providing more detailed information on the fundamental mechanisms of morphology development (during phase change) and profile forming. The die filling and solidification behaviours within extrusion dies… More >

Dyi-Cheng¹, Syuan-Yi Syong¹

CMC-Computers, Materials & Continua, Vol.13, No.3, pp. 191-200, 2009, DOI:10.3970/cmc.2009.013.191

Abstract Finite element simulations are performed to investigate the plastic deformation behavior of Ti-6Al-4V titanium alloy during its indirect extrusion through a four-hole die. The simulations assume the die, mandrel and container to be rigid bodies and ignore the temperature change induced during the extrusion process. Under various extrusion conditions, the present numerical analysis investigates the effective stress and profile of product at the exit. The relative influences of the friction factors, the temperature of billet and the eccentricity of four-hole displacement are systematically examined. The simulations focus specifically on the effects of the friction factor, billet temperature and eccentricity ratio… More >