Investigation of temperature effect on the mechanical properties of single-walled carbon nanotubes

A temperature-related higher-order gradient continuum theory is proposed for predicting the mechanical properties of single-walled carbon nanotubes (SWCNTs) at various temperatures. It is found that the axial elastic moduli of zigzag (21, 0), armchair (12, 12) and chiral (15, 9) SWCNTs with similar radii approach 0.7 TPa when T = 0 K, but decline slightly on different slopes. These results indicate that the temperature effect influences the axial Young moduli of zigzag SWCNTs less than those of the other types. Moreover, the parameters λ₁ and λ₂ corresponding to the uniform longitudinal and circumferential stretches at different temperatures are also examined, and the results show that with an increasing temperature, all SWCNTs are stretched in the longitudinal direction, while in the circumferential direction, only the zigzag SWCNTs are stretched, whereas the others are compressed.     

Performance of Object Classification Using Zernike Moment

Moments have been used in all sorts of object classification systems based on image. There are lots of moments studied by many researchers in the area of object classification and one of the most preference moments is the Zernike moment. In this paper, the performance of object classification using the Zernike moment has been explored. The classifier based on neural networks has been used in this study. The results indicate the best performance in identifying the aggregate is at 91.4% with a ten orders of the Zernike moment. This encouraging result has shown that the Zernike moment is a suitable moment to be used as a feature of object classification systems.     

Matching algorithms for three-stage bufferless Clos network switches

Three-stage Clos network switches are an attractive solution for future broadband packet routers due to their modularity and scalability. Most three-stage Clos network switches assume either all modules are space switches without memory (bufferless), or employ shared memory modules in the first and third stages (buffered). The former is also referred to as the space-space-space (S/sup 3/) Clos network switch, while the latter is referred to as the memory-space-memory (MSM) Clos network switch. We provide a survey of recent literature concerning switching schemes in the S/sup 3/ Clos network switch. The switching problem in the S/sup 3/ Clos network switch can be divided into two major parts, namely port-to-port matching (scheduling) and route assignment between the first and third stages. Traditionally, researchers have proposed algorithms to solve these issues separately. Recently, a new class of switching algorithms, called matching algorithms for Clos (MAC), has been proposed to solve scheduling and route assignment simultaneously. We focus on the MAC schemes and show that the new class of algorithms can achieve high performance and maintain good scalability.     

Pyomyositis in childhood: a case report

Pyomyositis is a primary infection of skeletal muscle. We report the case of a previously healthy six-year-old who suffered from pyomyositis in the right lower back. He presented with lower back pain and low-grade fever for one week. After a series of laboratory and imaging studies, the diagnosis of right multifidus muscle pyomyositis with abscess formation was made. The patient recovered rapidly after incision and drainage therapy, accompanied by antibiotic treatment. Methicillin-resistant Staphylococcus aureus was cultured from the abscess discharge. It was strongly suspected that herbal medicines and common cold medication the patient had been prescribed before admission to our hospital produced a masking effect that delayed the diagnosis.     

Pattern recognition techniques for the emerging field of bioinformatics: A review

The emerging field of bioinformatics has recently created much interest in the computer science and engineering communities. With the wealth of sequence data in many public online databases and the huge amount of data generated from the Human Genome Project, computer analysis has become indispensable. This calls for novel algorithms and opens up new areas of applications for many pattern recognition techniques. In this article, we review two major avenues of research in bioinformatics, namely DNA sequence analysis and DNA microarray data analysis. In DNA sequence analysis, we focus on the topics of sequence comparison and gene recognition. For DNA microarray data analysis, we discuss key issues such as image analysis for gene expression data extraction, data pre-processing, clustering analysis for pattern discovery and gene expression time series data analysis. We describe current methods and show how computational techniques could be useful in these areas. It is our hope that this review article could demonstrate how the pattern recognition community could have an impact on the fascinating and challenging area of genomic research.     

Clinical Evaluation of Burn Injuries Using an Optical Reflectance Technique

In a multiyear clinical study, the authors tested the reliability of an optical technique for diagnosing tissue damage on burn wounds. Optical reflectivity was measured using a convenient, bedside, noninvasive instrument (the Burn Depth Indicator), which was designed and built by one of the authors. The results show that this optical technique is more accurate than conventional methods for predicting the healing time of burn wounds which are otherwise difficult to assess. The optical properties of burn wounds were modeled using a three layer Kubelka-Munk model. We found that eschar thickness and the volume fraction and oxygen saturation of blood in the dermis determine the optical properties of the burn. These factors, in turn, are known to correlate with the burn depth and healing potential.     

Vibration of symmetrically laminated cantilever trapezoidal composite plates

The paper presents a general numerical method for vibration analysis of symmetrically laminated cantilever thin trapezoidal composite plates. The Rayleigh-Ritz method, along with displacements assumed in the form of 2-D orthogonal polynomials, is used to solve the problems. These 2-D orthogonal polynomials are generated using a proposed recurrence formula. Several numerical examples are presented to demonstrate the accuracy, efficiency and versatility of the method. Natural frequencies and mode shapes for the trapezoidal plates are obtained for different numbers of layers, fibre orientations, and ratios. These results, to the author's knowledge, are first known in the open literature. Thus the present study may provide very useful information to the engineers who work in this area.     

Analysis of laminated composite beams and plates with piezoelectric patches using the element-free Galerkin method

 An efficient meshfree formulation based on the first-order shear deformation theory (FSDT) is presented for the static analysis of laminated composite beams and plates with integrated piezoelectric layers. This meshfree model is constructed based on the element-free Galerkin (EFG) method. The formulation is derived from the variational principle and the piezoelectric stiffness is taken into account in the model. In numerical test problems, bending control of piezoelectric bimorph beams was shown to have the efficiency and accuracy of the present EFG formulation for this class of problems. It is demonstrated that the different boundary conditions and applied actuate voltages affects the shape control of piezolaminated composite beams. The meshfree model is further extended to study the shape control of piezo-laminated composite plates. From the investigation, it is found that actuator patches bonded on high strain regions are significant in deflection control of laminated composite plates. Received: 23 October 2001 / Accepted: 29 July 2002     

Anti-GBM glomerulonephritis in mice lacking nitric oxide synthase type 2

To determine the relationship between quantitative Doppler parameters of portal, hepatic, and splanchnic circulation and hepatic venous pressure gradient (HVPG), variceal size, and Child-Pugh class in patients with alcoholic cirrhosis, we studied forty patients with proved alcoholic cirrhosis who underwent Doppler ultrasonography, hepatic vein catheterization, and esophagoscopy. The following Doppler parameters were recorded: time-averaged mean blood velocity, volume flow of the main portal vein flow, and resistance index (RI) of the hepatic and of the superior mesenteric artery. Doppler findings were compared with HVPG, presence and size of esophageal varices, and Child-Pugh class. There was a significant inverse correlation between portal velocity and HVPG (r = -.69), as well as between portal vein flow and HVPG (r = -.58). No correlation was found between RI in the hepatic artery or superior mesenteric artery and HVPG. No correlation was found between portal vein measurements and presence and size of varices. Severe liver failure was associated with lower portal velocity and flow. In patients with alcoholic cirrhosis, only portal vein blood velocity and flow, but neither hepatic nor mesenteric artery RI, are correlated to the severity of portal hypertension and to the severity of liver failure.