Coupled-Mode Analysis of an NRD-Guide Coupler Based on Singular Perturbation Technique

A coupled-mode formulation for an NRD-guide coupler is presented using the singular perturbation technique. The first-order and second-order perturbations are taken into account in the analysis and the coupled-mode equations based on the eigenmodes of each waveguide in isolation are derived. The propagation constants obtained by these equations are compared with those by the exact theory, conventional coupled-mode theory, and improved coupled-mode theory. The numerical results of present formulation are in good agreement with the exact theory and superior to those of the other formulations.     

Epitaxially grown zinc-blende structured Mn doped ZnO nanoshell on ZnS nanoparticles

Zinc oxide in the bulk as well as in the nanocrystalline form is thermodynamically stable in the wurtzite structure. However, zinc oxide in the zinc-blende structure is more useful than that in the wurtzite structure due to its superior electronic properties as well as possibility of efficient doping. Therefore, zinc oxide shell is grown epitaxially on zinc sulphide core nanoparticles having zinc-blende structure. It is shown that doping of manganese could be achieved in zinc oxide nanoshell with zinc-blende structure.     

Design and cost analysis of low head simple reaction hydro turbine for remote area power supply

This paper is aimed at exploring the performance characteristics of a simple reaction hydro turbine for power generation. Using principles of conservation of mass, momentum and energy, the governing equations have been identified for an ideal case of no frictional losses. The paper also describes the conception of a cross-pipe rotor for remote area electricity production. Using the ideal governing equations an optimized geometry of the rotor was selected for the working head of 5 m. Theoretical analysis of the self-governing characteristics has been presented. Experiments were carried out for 2, 3, 4 and 5 m head and evaluated against theoretical results. Split pipe turbine model is presented with detail layout, while different methods of experimentation are explored for different output requirements with varied heads. Various losses in the system are discussed, quantified and included in the graphical format. It is also demonstrated that the experimental power outputs do not have the same tendencies as theoretical predictions and decreases due to jet interference beyond a certain rotational speed as it passes the maximum power point.     

Validation of fully implicit method for simulation of flows with interfaces using primitive variables

This paper describes applications of the fully implicit procedure for computing flow of two immiscible fluids. Six problems in two and three dimensions are solved to highlight effects of grid size, pressure smoothing, TVD convection scheme and geometric and fluid dynamic evaluations of surface tension force. Free surface and cavity flows are considered in which effect of sloshing, interface merger and splitting as well as splashing are included. Wherever possible, present solutions are compared with results of previous experiments and/or numerical computations. Computational details such as grid size, time step, under-relaxation factors, mass/volume conservation are reported.     

Three outbreaks of foodborne botulism caused by unsafe home canning of vegetables--Ohio and Washington, 2008 and 2009

Foodborne botulism is a potentially fatal paralytic illness caused by ingestion of neurotoxin produced by the spore-forming bacterium Clostridium botulinum. Historically, home-canned vegetables have been the most common cause of botulism outbreaks in the United States. During 2008 and 2009, the Centers for Disease Control and Prevention (CDC) and state and local health departments in Ohio and Washington State investigated three outbreaks caused by unsafe home canning of vegetables. We analyzed CDC surveillance data for background on food vehicles that caused botulism outbreaks from 1999 to 2008. For the three outbreaks described, patients and their family members were interviewed and foods were collected. Laboratory testing of clinical and food samples was done at the respective state public health laboratories. From 1999 to 2008, 116 outbreaks of foodborne botulism were reported. Of the 48 outbreaks caused by home-prepared foods from the contiguous United States, 38% (18) were from home-canned vegetables. Three outbreaks of Type A botulism occurred in Ohio and Washington in September 2008, January 2009, and June 2009. Home-canned vegetables (green beans, green bean and carrot blend, and asparagus) served at family meals were confirmed as the source of each outbreak. In each instance, home canners did not follow canning instructions, did not use pressure cookers, ignored signs of food spoilage, and were unaware of the risk of botulism from consuming improperly preserved vegetables. Home-canned vegetables remain a leading cause of foodborne botulism. These outbreaks illustrate critical areas of concern in current home canning and food preparation knowledge and practices. Similar gaps were identified in a 2005 national survey of U.S. adults. Botulism prevention efforts should include targeted educational outreach to home canners.     

A Novel real-time dosimetry technique based on radiation-induced surface activation

A novel real-time dosimetry technique based on radiation-induced surface activation (RISA) phenomenon has been proposed that is similar to ultraviolet surface activation known typically in anatase-type titanium dioxide. It has been found that the RISA phenomenon occurs on the surface of an oxidised semiconductor or oxidised metal film by radiation incidence. The RISA dosemeter has the following advantageous characteristics: (1) output of the RISA dosemeter is proportional to the dose equivalent rate in harsh environments, (2) fluctuation of output of the RISA dosemeter irradiated by (60)Co gamma-rays is <2.5% beyond the total dose equivalent of 1.8 MSv, (3) the transient current observed in simple insulators for a few seconds or more after onset of irradiation was not detected in the RISA dosemeter and (4) this dosemeter worked well even at high temperatures.     

Generation and Progress Behavior of Strain-Induced Abnormally Large Grains in Superalloy 718

Metallurgical and Materials Transactions A - Herein, the behavior associated with strain-induced abnormally large grains in superalloy 718 was investigated using compression testing and subsequent...     

Effect of heparin on high glucose induced proliferation and expression of matrix metalloproteinases in normal human mesangial cells

Background The pathogenesis of diabetic nephropathy (DN) is a complex pathophysiological process.Its precise mechanism is not fully known. In recent years it has been recognized that synthesis of various extracelluar matrix (ECM) components may increase, and that degradation of ECM may decrease in DN. It was reported heparin could inhibit mesangial cells proliferation in vitro. The main aim of this study is to explore whether heparin inhibits proliferation of mesangial cells grown in high glucose concentration and to measure the effect of heparin on matrix metalloproteinases (MMPs) expression in mesangial cells. Methods The medium contained either low glucose (5 mmol/L) or high glucose (25 mmol/L). The concentrations of heparin in the culture medium were 0, 25, 50,100, 200 or 400 μg/mL. A metabolic (WST-1) assay was used to measure mesangial cell proliferation and Western blot analysis was used to measure MMPs expression of mesangial cells. Results Normal human mesangial cell (NHMC) proliferation was higher in high glucose (HG) medium than in low glucose (LG) medium. They showed a 1.93 fold expansion after 72 h in high glucose in contrast to a 1.63 fold expansion in low glucose. In the presence of heparin, mesangial cells proliferation was inhibited, which was more obvious at high glucose concentrations than at low glucose concentrations. In high glucose, with heparin concentration of 50, 100, 200 and 400 μg/mL, the mesangial cells showed a 0. 61 fold, 0.52 fold, 0.52 fold and 0.41 fold reductions in cell number compared to cells grown without heparin. In low glucose, only concentrations of 200 μg/mL and 400 μg/mL showed reduction in cell number, namely 0.54 fold and 0.45 fold, when compared to cells grown without heparin. In Western blot analysis,MMP1, MMP2, MMP3 and MMP9 was expressed by mesangial cells expressed in both high and low glucose concentrations, which was more prominent in high glucose medium. Incubation of heparin further increased expression of MMP1, MMP2, MMP3 and MMP9. Conclusions This study suggests that glucose can accelerate mesangial cell proliferation while heparin can reduce proliferation, being more obvious at high glucose concentrations. Higher glucose concentrations led to increased MMP expression, which may take part in the regulation of mesangial matrix synthesis and degradation. Addition of heparin resulted in a corresponding increase in MMP expression, most notably at high glucose concentrations, indicating a potentially renoprotective role in DN.     

Management of gap non-union of tibia by tibialisation of ipsilateral vascular fibula

Community health, psychiatric, and pediatric nurses who work with young children and their families often assess the family's sleep and rest patterns, especially in relation to children's sleep disturbances. Nurses have traditionally taken a rigid approach on this issue that excludes culturally diverse options. The author uses examples from her own nursing education and from cross-cultural research to demonstrate the cultural bias favoring separation of child from parent. The article explores options for broadening nurses' assessment of family sleeping arrangements and designing interventions that take into consideration culturally diverse values and habits. Implications for nursing practice include greater trust-building and mutual learning.