C. J. Wu¹, C. Y. Chou¹, C. N. Han¹, K. N. Chiang²

CMES-Computer Modeling in Engineering & Sciences, Vol.41, No.1, pp. 49-68, 2009, DOI:10.3970/cmes.2009.041.049

Abstract In this paper, the atomistic-continuum mechanics method (ACM) is applied for carbon nanotube modeling. The atomistic-continuum mechanics is based on the transformation of chemical bonds between atoms in molecular mechanics into appropriate elements in finite element method and continuum mechanics. Spring elements are treated as chemical bonds between carbon atoms in carbon nanotube, whose force-displacement function is determined by the Reactive Empirical Bond Order (REBO) potential model. The advantages and unique feature of ACM method is same analytical model can be used for both tensile and vibration analyses, and most importantly, there are no prior More >

Andrew J. Macnab, Lynn Stothers

Canadian Journal of Urology, Vol.15, No.5, pp. 4241-4248, 2008

Abstract Introduction: Near infrared spectroscopy (NIRS) is a non-invasive optical technique able to monitor changes in the concentration of oxygenated and deoxygenated hemoglobin in the bladder detrusor during bladder filling and emptying.
Objective: To evaluate the ability of a new NIRS instrument and algorithm to classify male patients with LUTS as obstructed or unobstructed based on comparison with classification via conventional invasive urodynamics (UDS).
Method: Male patients with LUTS were recruited and underwent uroflow and urodynamic pressure flow studies with simultaneous transcutaneous NIRS monitoring following measurement of post residual volume (PVR) via ultrasound. Data analysis first classified each subject… More >

G. Papaioannou¹, G. Nianios¹, C. Mitroyiannis¹, S.Tashman², K.H. Yang²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.8, No.1, pp. 7-12, 2008, DOI:10.3970/icces.2008.008.007

Abstract Little is known about in vivo menisci loads and displacements in the knee during strenuous activities. We have developed a method that combines biplane high-speed dynamic radiography (DRSA) and a subject-specific finite element model for studying in vivo meniscal behavior. In a very controlled uniaxial compression loading condition, removing of the pressure sensor from the model can result in relatively large errors in contact and cartilage stress that are not reflected in the change of meniscal displacement. More >

M-A Lavoie¹, A. Gakwaya¹, M. Nejad Ensan², D.G. Zimcik²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.2, No.4, pp. 111-118, 2007, DOI:10.3970/icces.2007.002.111

Abstract This paper reviews numerical methods that are currently available to simulate bird strike as well as the theory of the event. It also summarizes important parameters and provides guidelines as to how to set up the analysis and how to evaluate a model. The information provided is based on physical properties and available results regarding a bird and its behaviour upon impact. The simulations have been performed with LS-DYNA 970 but can be done in similar dynamic finite elements analysis codes. More >

Joseph G. Lawrence, Arunan Nadarajah¹

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.3, pp. 247-254, 2007, DOI:10.3970/fdmp.2007.003.247

Abstract A simplified 2D pseudo steady state model was developed for an atmospheric chemical vapor deposition (CVD) process on glass. This is used to study the feasibility of converting a continuous coating process to one with discrete glass plates with a gap between them. A preliminary estimate employing mass transfer correlations suggested that there would be significant concentration variations due to the gap between the plates. More detailed studies were done by solving the model numerically employing a finite difference scheme with a vorticity-stream function formulation, and employing the commercial computational fluid dynamics program FIDAP which… More >

Pierre I Karakiewicz, Jean-Baptiste Lattouf, Paul Perrotte, Luc Valiquette, François Bénard, Michael McCormack, Catherine Ménard, Thierry Lebeau, Serge Benayoun, Alvaro Ramirez, Simon Ouaknine, Fred Saad

Canadian Journal of Urology, Vol.12, No.2, pp. 2588-2592, 2005

Abstract Objective: The accuracy of 1997 Partin Tables' lymph node invasion (LNI) predictions exhibits important variability in different testing populations. We explored the LNI predictive accuracy in radical prostatectomy (RP) patients from Montreal, Canada. Moreover, we assessed the extent of change in predictive accuracy related to a modification of PSA coding from categorical to continuous.
Methods: We used pretreatment serum PSA, clinical stage, and biopsy Gleason sum from 537 men treated with RP to compare predicted and observed rates of LNI. Accuracy was quantified with receiver-operating characteristics curves.
Results: Accuracy was 0.760 in 369 evaluable patients, when categorically coded More >

P. I. Karakiewicz¹, P. Perrotte², L. Valiquette², F. Benard², M. McCormack², C. Menard², M. McNaughton Collins³, J. C. Nickel⁴

Canadian Journal of Urology, Vol.12, No.5, pp. 2816-2823, 2005

Abstract Introduction: The NIH Chronic Prostatitis Symptom Index (CPSI) is recommended in the clinical evaluation of men with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). However, its use is not possible in French speakers, as it has not been validated in this population. We performed a linguistic validation of the CPSI.
Methods: Linguistic translation followed the forward-backward-forward technique and relied on professional medical translators, bilingual health professionals, and patient input. Along with the SF-12, the translated version was administered to a convenience sample of men presenting for pre-vasectomy visits (controls) and to consecutive patients with established CP/CPPS (cases). Men… More >

Canadian Journal of Urology, Vol.12, No.6, pp. 2873-2879, 2005

Abstract Background: Assessment of prostate cancer (PCa) specific and generic health-related quality-of-life (HRQOL) is frequently omitted due to several obstacles, such as respondent burden and infrastructure-related limitations. We attempted to reduce the number of items of two commonly used HRQOL assessment tools, namely the UCLA PCa Index (PCI) and the RAND SF-12, with the intent of generating the most parsimonious, yet psychometrically valid and reliable HRQOL assessment tool.
Methods: The PCI and SF-12 were administered to 2415 radical prostatectomy patients, and re-tested in a convenience sample of 35 men with PCa. Multivariate linear regression models defined the most… More >

N. D. Ngo, K. K. Tamma¹

CMES-Computer Modeling in Engineering & Sciences, Vol.1, No.3, pp. 57-72, 2000, DOI:10.3970/cmes.2000.001.359

Abstract In the process modeling via Resin Transfer Molding (RTM) for thick composite sections, multi-layer preforms with varying thermophysical characteristics across the different layers, or for geometrically complex mold geometries with varying thicknesses, the assumption of a thin shell-like geometry is no longer valid. The flow in the through thickness direction is no longer negligible and current practices of treating the continuously moving flow front as two-dimensional and the temperature and cure as three-dimensional are not representative of the underlying physics. In view of these considerations, in the present study, the focus is on the non-isothermal… More >

K. Garikipati¹, V.S. Rao², M.Y. Hao³, E. Ibok⁴, I. de Wolf⁵, R. W. Dutton⁶

CMES-Computer Modeling in Engineering & Sciences, Vol.1, No.1, pp. 65-84, 2000, DOI:10.3970/cmes.2000.001.065

Abstract This work is based upon a careful rendering of mechanics and mathematics to describe the phenomena that influence the stress engendered by the Shallow Trench Isolation process. The diffusion-reaction problem is posed in terms of fundamental mass balance laws. Finite strain kinematics is invoked to model the large expansion of SiO₂, dielectrics are modelled as viscoelastic solids and annealing-induced density relaxation of SiO₂ is incorporated as a history-dependent process. A levelset framework is used to describe the moving Si/SiO₂ interface. Sophisticated finite element methods are employed to solve the mathematical equations posed for each phenomenon. These include More >