Jin Yeon Cho¹, Jae Mo An², You Me Song¹, Seungsoo Lee¹, Dong Whan Choi¹

CMES-Computer Modeling in Engineering & Sciences, Vol.9, No.1, pp. 1-18, 2005, DOI:10.3970/cmes.2005.009.001

Abstract A displacement welding technique is proposed to carry out coupled analysis of the integrated whole model which consists of independently modeled finite element substructures. In the proposed method, the incompatible displacement fields in the interfaces of independently modeled substructures are directly welded together through a blended function that is newly defined in the transient region of mismatching interface. To construct the blended function, the moving least squares function, which does not require well-defined nodal connectivity, is utilized along with the original finite element shape function. The meshless character of the moving least squares function makes More >

W. J. Ferguson¹, B. Palananthakumar²

CMES-Computer Modeling in Engineering & Sciences, Vol.8, No.3, pp. 201-216, 2005, DOI:10.3970/cmes.2005.008.201

Abstract Environmental and safety issues associated with landfill gas require the control of off-site migration. Mathematical modelling can assist in the understanding of the processes and mechanisms controlling gas migration from municipal waste disposal sites. This paper presents the development and application of a mathematical model that simulates landfill gas migration within a partially saturated soil. This model accounts for two-phase flow and incorporates multi-component (methane, carbon dioxide, dry air and moisture) transport in the gas and liquid phases together with concomitant heat migration. The governing system of fully coupled non-linear partial differential equations of the… More >

Wanlin Guo^1,2, Huajian Gao²

CMES-Computer Modeling in Engineering & Sciences, Vol.7, No.1, pp. 19-34, 2005, DOI:10.3970/cmes.2005.007.019

Abstract A systematic investigation is performed on energy dissipation related interaction force associated with interlayer motion of sliding, rotation and telescoping between any two possible neighboring carbon nanotubes. In particular, we analyze the interlayer corrugation energy and sliding, rotation and telescoping resistance force associated with the Lennard-Jones potential as well as a registry-dependent graphitic potential. It is found that the interlayer resistance associated with both of these potentials can vary with the morphology, length and diameter of the two tubes. Energy dissipation related fluctuation of the resistant force can be as low as 10^-18N/atom between the most More >

Sean van Diepen, John Grantmyre

Canadian Journal of Urology, Vol.11, No.1, pp. 2139-2140, 2004

Abstract Double-J ureteral stents facilitating the drainage of urine from the kidney to the bladder are widely used. Stents designed for patient self-removal are commonplace. We report a case of urosepsis that lead to the incidental discovery of a failed self-removal of a double-J ureteral stent. The retrieval cord broke during self-removal and the patient mistook the string for the stent. Adequate patient education is essential to assure successful self-removal. More >

Shabbir M. H. Alibhai¹, Laurence H. Klotz²

Canadian Journal of Urology, Vol.11, No.1, pp. 2110-2117, 2004

Abstract Introduction: Most treatment studies of localized prostate cancer are observational in nature. The recent publication of a large randomized trial of radical prostatectomy (RP) versus watchful waiting (WW) has focused increased attention on the treatment of localized prostate cancer. We reviewed all published randomized trials that compared different primary treatment modalities for localized prostate cancer.
Materials and methods: We performed a comprehensive Medline search from 1966 to March 2003 to identify all English-language randomized trials of RP, external-beam radiotherapy (EBRT), brachytherapy, watchful waiting, and primary androgen-deprivation therapy in localized prostate cancer.
Results: Nine publications dealing with four separate… More >

Daxiang Cui¹, Cengiz S. Ozkan², Sathyajith Ravindran³, Yong Kong¹, Huajian Gao¹

Molecular & Cellular Biomechanics, Vol.1, No.2, pp. 113-122, 2004, DOI:10.3970/mcb.2004.001.113

Abstract Experiments on encapsulating Pt--labelled DNA molecules inside multiwalled carbon nanotubes (MWCNT) were performed under temperature and pressure conditions of 400K and 3 Bar. The DNA-CNT hybrids were purified via agarose gel electrophoresis and analyzed via high resolution transmission electron microscopy (HR-TEM) and energy dispersive X-ray spectroscopy (EDX). The results showed that the Pt-labelled DNA molecules attached to the outside walls of CNTs could be removed by electrophoresis. The HR-TEM and EDX results demonstrated that 2-3% of the Pt-labelled DNA molecules were successfully encapsulated inside the MWCNTs. The experimental study complements our previous molecular dynamics simulations More >

Wan-Sul Lee, Kie-Chan Kwon, Bong-Kyu Kim, Ji-Hyon Cho, Sung-Kie Youn¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.3, pp. 279-286, 2004, DOI:10.3970/cmes.2004.005.279

Abstract A numerical approach for eigenvalue analysis of the electrostatically tunable micro-mechanical actuators is presented. An efficient algorithm for calculating the natural frequency shifting in the micro-mechanical actuators due to applied DC turning voltage is proposed. In the calculations of the coupled field problem, the three-dimensional FEM/BEM approaches and iterative staggered algorithm are employed. The numerical examples for actually fabricated actuators are presented and the numerical analysis results are compared with experimental data. More >

Humihiko Gotou¹, Takashi Kuwataka¹, Terumasa Nishihara¹, Tetsuo Iwakuma¹

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.2, pp. 319-328, 2003, DOI:10.3970/cmes.2003.004.319

Abstract The stiffness equation in finite displacement problems is often derived from the virtual work equation, partly in order to avoid the complicated formulation based on the potential functional. Describing the virtual rotational angles by infinitesimal rotational angles about three axes of the right-angled Cartesian coordinate system, we formulate tangent stiffness equations whose rotational degrees of freedom are described by rotational angles about the three axes. The rotational degrees of freedom are useful to treat three rotational components in nodal displacement vectors as vector components for coordinate transformation, when non-vector components like Euler's angles are used More >

David G. Bell, Marc Anthony Fischer

Canadian Journal of Urology, Vol.9, No.1, pp. 1470-1474, 2002

Abstract The establishment and maintenance of effective urinary tract drainage for patients with malignant extrinsic ureteric obstruction is a formidable challenge for the urologist. We have utilized an alternative method of urinary diversion, called Palliative Subcutaneous Tunneled Nephrostomy Tubes (PSTN), for long term urinary tract drainage when intracoropreal stenting has failed or is not tolerated. PSTN provides a simple and effective method of external urinary diversion and preservation of renal function. This technique should be an option in the armamentarium of urologists for management of malignant ureteral obstruction. More >

Yansong Wang¹, Q. Jane Wang¹, Chih Lin²

CMES-Computer Modeling in Engineering & Sciences, Vol.3, No.4, pp. 517-530, 2002, DOI:10.3970/cmes.2002.003.517

Abstract Many mechanisms, such as computer hard drives, gear trains, and machine tool spindle systems, operate under both axial and radial loads, which should be respectively supported by a thrust and a journal bearing. By utilizing the end face of the shaft of a journal bearing as a thrust bearing, a coupled journal-thrust bearing system can be formed. This paper presents a mixed lubrication model developed to investigate the lubrication of this coupled bearing system. A conformal-mapping method is used in the model formulation to facilitate a universal flow description. The performance of typical coupled bearing More >