Three-dimensional cohesive fracture modeling of non-planar crack growth using adaptive FE technique

AbstractIn this paper, the three-dimensional adaptive finite element modeling is presented for cohesive fracture analysis of non-planer crack growth. The technique is performed based on the Zienkiewicz–Zhu error estimator by employing the modified superconvergent patch recovery procedure for the stress recovery. The Espinosa–Zavattieri bilinear constitutive equation is used to describe the cohesive tractions and displacement jumps. The 3D cohesive fracture element is employed to simulate the crack growth in a non-planar curved pattern. The crack growth criterion is proposed in terms of the principal stress and its direction. Finally, several numerical examples are analyzed to demonstrate the validity and capability of proposed computational algorithm. The predicted crack growth simulation and corresponding load-displacement curves are compared with the experimental and other numerical results reported in literature

Index Analysis Model to Enhance User Comfort in Energy Efficient Buildings

This paper presents the research proposal initiated based on needs of high developing country like Malaysia in energy efficiency studies. The research proposal developed based on a “current†research gap to enhance design related building user comfort criteria towards efficient energy used. Research aims to develop index analysis model to enhance consideration of user comfort towards efficient energy use. The relevant objective and methodology of research in four (4) phases is presented. Firstly, it is to investigate building design attributes related to user comfort in sample size of office buildings. Secondly, it is to capture architectural design related “Energy Efficient†attributes using the same sample size of energy efficient consultants within conducting quantitative interviews. Thirdly, it is to evaluate interrelation of EE attributes versus user comfort attributes with in professional group discussion. Finally, it is to develop index analysis model in consideration of user comfort towards efficient energy used. Accordingly, each objective comply novel findings. In conclusion this paper brief proposed research steps to aims to develop index analysis model to enhance consideration of user comfort towards efficient energy use

Microstructure development, mechanical and tribological properties of a semisolid A356/xSiCp composite

This paper presents the results of experimental investigation on microstructure (size and morphology of eutectic Si), impact toughness and sliding wear properties of A356 Al-Si alloy and composites containing 10, 20 and 25 wt% of SiCp reinforcement produced by semisolid stirring technique. The results revealed that an increase in SiCp content leads to a reduction in the size of eutectic Si and also changes its morphology from plate-like to equiaxed. Furthermore, addition of 10 and 20 wt% silicon carbide reinforcement decreased the impact toughness by 6 and 18%, respectively. A356/25wt%SiCp composite registered the lowest impact toughness with reduction of 33% due to debonding and agglomeration of SiCp in the matrix. The sliding wear results showed that the wear resistance of the composites was significantly higher than that of the matrix alloy due to the increase in hardness as well as reduction in the size and also morphology transformation of eutectic silicon with increase in SiCp content. However, the existence of particle-porosity clustering with increasing the SiCp content to 25 wt% played a significant role in deteriorating the wear behavior of the composite

Length-length, length-weight relationship and relative condition factor of pike, Esox lucius Linnaeus, 1758, in Anzali Wetland (Southwest of the Caspian Sea)

The length-length (LLRs), length-weight (LWR) relationships and relative condition factor (Kn) of 505 specimens of pike, (Esox lucius Linnaeus, 1798) from Anzali Wetland, southwest of the Caspian Sea, were studied from April 2012 through March 2013. The length-length relationships among total length (TL), fork length (FL) and standard length (SL) for pike were found to be highly significant (r2>0.986, P<0.001). The values of b in length-weight relationship in males (3.1495), females (3.1843) and for all specimens (3.2137) indicated isometric growth. Mean relative condition factor for male, female and all specimens were 1.003, 1.004 and 1.008 respectively. The result of LWR could be used for fishery managers to approve appropriate regulations for sustainable fishery management. Few studies have been conducted on these parameters of pike and this is the first report on LLRs, LWR and Kn of pike from Iranian waters

Construction of an internal amplification control for Mycobacterium tuberculosis polymerase chain reaction (PCR) test

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (MTB) which mostly affects the lungs. The disease causes deaths of many people every year. There are different methods to detect MTB such as skin test, staining, culture and molecular techniques. Polymerase chain reaction (PCR) is a simple and rapid method for the detection of MTB; however, positive and negative false results reduce the efficiency of this technique. The aim of this study was to design an internal amplification control (IAC) and apply it in MTB PCR test. PCR technique for MTB was optimized by using specific primers for IS6110 gene. The sensitivity and specificity of the test were determined. IAC was constructed with competitive strategy by PCR-cloning technique and the limitation range was determined. The PCR products of MTB and IAC were 245 and 660 bp, respectively on electrophoresis gel. The IC used in PCR testing of MTB is the competitive form in which the range was between 10 million and 10 bacteria and the most suitable internal control concentration for the mix was 1,000 plasmids. After making IC and using it in MTB amplification, it was observed that IC might guarantee the correctness of PCR reaction.Keywords: Mycobacterium tuberculosis, polymerase chain reaction (PCR), internal control.African Journal of Biotechnology Vol. 12(27), pp. 4277-428

Optimization of Tube Hydroforming Process Using Simulated Annealing Algorithm

AbstractIn this paper, forming parameters of tube hydroforming (THF) process are investigated and optimized using Simulated Annealing optimization algorithm linked with a finite element commercial code. The goal of this research is to obtain the maximum formability of two dimensional (2D) axisymmetric tubes under a failure criteria based on material's forming limit diagram (FLD). The initial approximated pressure loading path is determined by proved theoretical equations. Then the Simulated Annealing algorithm written in Matlab software is combined with a nonlinear structural finite element code ANSYS/ LS-DYNA in order to optimize internal hydraulic pressure. The results are compared by experimental observations and a good agreement was observed between them

Complications and carcinogenic effects of mustard gas - A systematic review and meta-analysis in Iran

Background: Catastrophic effects of mustard gas as a chemical warfare agent have always been a major problem for those exposed to this agent. In this meta-analysis it was tried to evaluate carcinogenesis, ocular, cutaneous and respiratory complications of mustard gas exposure among Iranians who had been exposed to this agent during the Iran-Iraq war. Materials and Methods: In this meta-analysis, the required data were collected using keywords "mustard gas", "sulfur mustard", "cancer", "neoplasm", "respiratory complications", "ocular complications", "lung disease", "chronic complication", "eye", "skin", "cutaneous complication", "carcinogenesis" and their combination with keywords "Iran", "Iranian", "prevalence", "mortality" and their Farsi equivalent terms from the databases of SID, Iranmedex, Magiran, Pubmed, Science Direct, Google Search engine, Gray Literature and Reference of References. To determine the prevalence of each complication and perform meta-analysis, CMA: 2 (Comprehensive Meta-Analysis) software with a randomized model was used. Results: Of the 542 articles found, 7 national articles, consistent with the aims of this study were selected. Metaanalysis of seven papers revealed that cancer risk, especially cancer of the respiratory system was elevated, so that the relative risk (RR) of cancer role of mustard gas was inconsistent from 2/1 to 4 in this survey. Also prevalence of delayed skin disorders due to sulfur mustard was 94.6, pulmonary complications 94.5 and ocular complications 89.9. The incidence of various cancers in victims exposed to mustard gas was 1.7 worldwide where the rate was 2.2 in Iranian victims of the Iraq-Iran war. Conclusions: Based on present study the prevalence of delayed mustard gas related cutaneous, pulmonary and ocular complications is above 90 and risk of carcinogenesis is higher in comparison to worldwide statistics. This may suggest need for long-term and persistent follow-up and rehabilitation procedures es for populations exposed to this agent

Intraoperative hypothermia during cytoreductive surgery for ovarian cancer and perioperative morbidity

OBJECTIVE: To evaluate intraoperative hypothermia as a predictor for morbidity after open abdominal surgery for ovarian cancer. METHODS: This cohort study included 146 women with stage IIIC and IV ovarian cancer who underwent debulking surgery at our institution from January 1, 2001, through December 31, 2003. Hypothermia was defined as end operative temperature lower than 36\ub0 C. Early complications (occurring within 30 days of surgery) included: mortality, infectious morbidities, cardiovascular events, venous thromboembolic (VTE) events, anastomotic leak, readmission, and reoperation. Survival was also evaluated. Logistic regression models were used to adjust for known confounders. RESULTS: The mean age was 63.9\ub111.7 years; 46 (32%) patients had a body mass index higher than 30; mean operative time was 239\ub185 minutes. There were five deaths perioperatively, all in the hypothermic group. Hypothermia was associated with an increased risk of any early complications (34 [42.0%] compared with 11 [16.9%]) with an adjusted odds ratio (OR) of 3.40 (95% confidence interval [CI] 1.48-8.33). For individual complications, hypothermic patients were at higher risk for VTE events with an adjusted OR of 3.53 (95% CI 1.02-16.44); infectious morbidity with an adjusted OR of 2.99 (95% CI 0.97-11.35); and reoperation with an adjusted OR of 4.96 (95% CI 0.80 -95.7). The overall survival was shorter in hypothermic group with a median of 34 compared with 45 months (P=.045); this remained significant for an optimally resected subgroup with a median overall survival of 40 compared with 48 months (P=.049). CONCLUSION: Surgical hypothermia is an independent predictor of early perioperative complications and overall survival after cytoreductive surgery for ovarian cancer. This is a critically important finding, because maintaining normothermia is an inexpensive modifiable factor, which could result in reduced morbidity

Non-conventional therapeutics for oral infections

© 2015 Robert P Allaker and CW Ian Douglas. As our knowledge of host-microbial interactions within the oral cavity increases, future treatments are likely to be more targeted. For example, efforts to target a single species or key virulence factors that they produce, while maintaining the natural balance of the resident oral microbiota that acts to modulate the host immune response would be an advantage. Targeted approaches may be directed at the blackpigmented anaerobes, Porphyromonas gingivalis and Prevotella intermedia, associated with periodontitis. Such pigments provide an opportunity for targeted phototherapy with high-intensity monochromatic light. Functional inhibition approaches, including the use of enzyme inhibitors, are also being explored to control periodontitis. More general disruption of dental plaque through the use of enzymes and detergents, alone and in combination, shows much promise. The use of probiotics and prebiotics to improve gastrointestinal health has now led to an interest in using these approaches to control oral disease. More recently the potential of antimicrobial peptides and nanotechnology, through the application of nanoparticles with biocidal, antiadhesive and delivery capabilities, has been explored. The aim of this review is to consider the current status as regards non-conventional treatment approaches for oral infections with particular emphasis on the plaque-related diseases