On the fourth-order accurate compact ADI scheme for solving the unsteady Nonlinear Coupled Burgers' Equations

The two-dimensional unsteady coupled Burgers' equations with moderate to severe gradients, are solved numerically using higher-order accurate finite difference schemes; namely the fourth-order accurate compact ADI scheme, and the fourth-order accurate Du Fort Frankel scheme. The question of numerical stability and convergence are presented. Comparisons are made between the present schemes in terms of accuracy and computational efficiency for solving problems with severe internal and boundary gradients. The present study shows that the fourth-order compact ADI scheme is stable and efficient

Is composite noise necessary for sudden death of entanglement?

The finite time disentanglement or entanglement sudden death, when only one part of the composite system is subjected to a single noise, is examined. While it is shown that entanglement sudden death can occur when a part of the entangled mixed state is subjected to either amplitude noise or phase noise, local action of either of them does not cause entanglement sudden death in pure entangled states. In contrast, depolarizing noise is shown to have an abilitiy to cause sudden death of entanglement even in pure entangled states, when only one part of the state is exposed to it. The result is illustrated through the action of different noisy environments individually on a single qubit of the so-called X class of states and an arbitrary two-qubit pure state.Comment: 6 pages, 4 figures; Version 3: Accepted for publication in the Results in Physics: Comments welcom

Towards High-order Methods for Rotorcraft Applications

This work presents CFD results obtained with an efficient, high-order, finite-volume scheme. The formulation is based on the variable extrapolation MUSCL-scheme, and high-order spatial accuracy is achieved using correction terms obtained through successive differentiation. The scheme is modified to cope with physical and multiblock mesh interfaces, so stability, conservativeness, and high-order accuracy are guaranteed. Results with the proposed scheme for steady flows, showed better wake and higher resolution of vortical structures compared with the standard MUSCL, even when coarser meshes were employed. The method was also demonstrated for unsteady flows using overset and moving grids for the UH-60A rotor in forward flight and the ERICA tiltrotor in aeroplane mode. The present method adds CPU and memory overheads of 47% and 23%, respectively, in performing multi-dimensional problems for routine computations

Prediction of Helicopter Rotor Hover Performance using High Fidelity CFD Methods

No abstract available

A Two-Stage GIS-Based Suitability Model for Siting Biomass-to-Biofuel Plants and its Application in West Virginia, USA

Woody biomass has been considered of low value because the cost of removal generally exceeded market price. New, valued-added markets to offset removal costs are necessary for utilization to be effective. In recent years the use of biomass as feedstock for biofuel production in the United States has been on the rise. A variety of liquid fuels can be produced from woody biomass; ethanol is one of the most promising. This study presents a two-stage approach to selecting woody biomass-based biofuel plants using Geographical Information System (GIS) spatial analysis and the multi-criteria analysis ranking algorithm of compromise programming. Site suitability was evaluated to minimize direct cost for investors and potential negative environmental impacts. The first step was to create a site suitability index using a linear fuzzy logic prediction model. The model involved 15 variables in three factor groups: (1) general physical conditions, (2) costs, and (3) environmental factors. The weights of the cost factors were determined using pairwise comparisons in the Analytical Hierarchy Process (AHP). The value of site suitability was reclassified into three categories (non-suitable, low-suitable, and high-suitable) using different classification methods. With a feasible plant location defined as an industrial site within the most suitable area, the second stage of the analysis used compromise programming to compare the potential sites. The criteria used to rank the potential sites included fuzzy distance to woody biomass, highways, railways, commercial airports, communities, and available parcel size. The AHP was used to compute the relative importance of each criterion. The top ten suitable sites were determined, and sensitivity analyses were conducted to derive the most preferred sites. The approach was successful in taking a large amount of non-commensurate spatial data and integrating a site-based ranking algorithm to find the top locations for biomass plants. It also has great potential and applicability to other suitability and site selection studies

Clostridium difficile Infection in Patients Discharged from US Short-stay Hospitals, 1996–20031

Clinicians should be aware of the increasing risk of C. difficile–associated disease and make efforts to control its transmission

Ears of the Armadillo: Global Health Research and Neglected Diseases in Texas

Neglected tropical diseases (NTDs) have\ud been recently identified as significant public\ud health problems in Texas and elsewhere in\ud the American South. A one-day forum on the\ud landscape of research and development and\ud the hidden burden of NTDs in Texas\ud explored the next steps to coordinate advocacy,\ud public health, and research into a\ud cogent health policy framework for the\ud American NTDs. It also highlighted how\ud U.S.-funded global health research can serve\ud to combat these health disparities in the\ud United States, in addition to benefiting\ud communities abroad

Relationships among different geographical groups, agro-morphology, fatty acid composition and RAPD marker diversity in Safflower ( Carthamus tinctorius )

Patterns of geographical diversity, and the relationship between agro-morphological traits and fatty acid composition were assessed for 193 safflower (Carthamus tinctorius) accessions representing forty countries. Accessions were assigned to eight groups based on geographical proximity. Cluster and Principal Component analyses were performed to assess patterns of diversity among the accessions and to select the most distant accessions from each of eight groups for analysis of randomly amplified polymorphic DNA (RAPD) markers. There was a large amount of diversity for agro-morphological traits, fatty acid composition, and RAPD markers. Most correlations among different traits were rather low. Plant height showed a positive correlation with days to flowering (r=0.63**). Palmitic acid was positively correlated with stearic acid and oleic acid values, and negatively correlated with linoleic acid (P<0.01). Oleic acid and linoleic acid showed a strong negative correlation (r=−0.89**). The first three principal components together explained 59% of the variation, however, neither principal component analysis (PCA) nor marker analysis revealed a clear relationship between diversity pattern and geographical origin. Accessions from some geographical regions tended to group together, such as accessions from South Western Asia, Central Western Europe, and the Mediterranean region. The correlation between the morphological matrix and the genetic matrix based on RAPD markers was not significant (r=0.027). Wide diversity in safflower germplasm indicates a considerable potential for improving this crop for both agronomic and quality trait

Contraception use among Muslim women in Alexandria, Egypt: a descriptive pilot study

Background: This pilot study aimed to create a questionnaire survey directed to understand knowledge gaps related to contraception among Muslim women in Alexandria, Egypt, so potential interventions could be designed to enable more informed decision-making. The project was a mixed-method, cross-sectional study using a questionnaire survey.Methods: Participants were randomly selected at outpatient clinics at Alexandria university hospitals in September and October 2020. The inclusion criteria were to be an 18 year old or older woman and able to give consent. The recruitment goal for this pilot study was 100 participants. The consented participants were interviewed about demographics, socio-structural and contraception use. The questionnaire was tested using a focus group of 11 women. The study data was collected using KoBoToolbox and exported to the SPSS software for descriptive analysis. The primary outcome was to validate the survey questionnaire and the secondary outcome to assess knowledge regarding contraception methods and emergency contraception.Results: The age of study participants ranged from 18-60 with a mean of 34 years. Almost all participants had previously heard of various contraceptive methods and 75% used them before. The majority did not know about emergency contraception. Most respondents had a favorable attitude toward family planning, and their primary sources of information were family and friends.Conclusions: Preliminary findings show that most women knew about contraception methods, though few of them heard of emergency contraception. Because of the patriarchal nature of Egyptian society, family planning education should target the whole population