bluuebunny/crossref_metadata_2025 huggingface dataset:
Mitigating the Effects of Landscape Development on Streams in Urbanizing Watersheds
Authors: Hogan Dianna M. , Jarnagin S. Taylor , Loperfido J.V. , Van Ness Keith
Published: September 2013

This collaborative study examined urbanization and impacts on area streams while using the best available sediment and erosion control (S&EC) practices in developing watersheds in Maryland, United States. During conversion of the agricultural and forested watersheds to urban land use, land surface topography was graded and vegetation was removed creating a high potential for sediment generation and release during storm events. The currently best available S&EC facilities were used during the development process to mitigate storm runoff water quality, quantity, and timing before entering area streams. Detailed Geographic Information System (GIS) maps were created to visualize changing land use and S&EC practices, five temporal collections of LiDAR (light detection and ranging) imagery were used to map the changing landscape topography, and streamflow, physical geomorphology, and habitat data were used to assess the ability of the S&EC facilities to protect receiving streams during development. Despite the use of the best available S&EC facilities, receiving streams experienced altered flow, geomorphology, and decreased biotic community health. These impacts on small streams during watershed development affect sediment and nutrient loads to larger downstream aquatic ecosystems such as the Chesapeake Bay.
Interplay between human microglia and neural stem/progenitor cells in an allogeneic co‐culture model
Authors: Liu Jia , Hjorth Erik , Zhu Mingqin , Calzarossa Cinzia , Samuelsson Eva‐Britt , Schultzberg Marianne , Åkesson Elisabet
Published: September 2013

Experimental neural cell therapies, including donor neural stem/progenitor cells (NPCs) have been reported to offer beneficial effects on the recovery after an injury and to counteract inflammatory and degenerative processes in the central nervous system (CNS). The interplay between donor neural cells and the host CNS still to a large degree remains unclear, in particular in human allogeneic conditions. Here, we focused our studies on the interaction of human NPCs and microglia utilizing a co‐culture model. In co‐cultures, both NPCs and microglia showed increased survival and proliferation compared with mono‐cultures. In the presence of microglia, a larger subpopulation of NPCs expressed the progenitor cell marker nestin, whereas a smaller group of NPCs expressed the neural markers polysialylated neural cell adhesion molecule, A2B5 and glial fibrillary acidic protein compared with NPC mono‐cultures. Microglia thus hindered differentiation of NPCs. The presence of human NPCs increased microglial phagocytosis of latex beads. Furthermore, we observed that the expression of CD200 molecules on NPCs and the CD200 receptor protein on microglia was enhanced in co‐cultures, whereas the release of transforming growth factor‐β was increased suggesting anti‐inflammatory features of the co‐cultures. To conclude, the interplay between human allogeneic NPCs and microglia, significantly affected their respective proliferation and phenotype. Neural cell therapy including human donor NPCs may in addition to offering cell replacement, modulate host microglial phenotypes and functions to benefit neuroprotection and repair.
A multivariate view of the evolution of sexual dimorphism
Authors: Wyman M. J. , Stinchcombe J. R. , Rowe L.
Published: September 2013

Sexual differences are often dramatic and widespread across taxa. Their extravagance and ubiquity can be puzzling because the common underlying genome of males and females is expected to impede rather than foster phenotypic divergence. Widespread dimorphism, despite a shared genome, may be more readily explained by considering the multivariate, rather than univariate, framework governing the evolution of sexual dimorphism. In the univariate formulation, differences in genetic variances and a low intersexual genetic correlation () can facilitate the evolution of sexual dimorphism. However, studies that have analysed sex‐specific differences in heritabilities or genetic variances do not always find significant differences. Furthermore, many of the reported estimates of are very high and positive. When monomorphic heritabilities and a high are present together, the evolution of sexual dimorphism on a trait‐by‐trait basis is severely constrained. By contrast, the multivariate formulation has greater generality and more flexibility. Although the number of multivariate sexual dimorphism studies is low, almost all support sex‐specific differences in the G (variance‐covariance) matrix; G matrices can differ with respect to size and/or orientation, affecting the response to selection differently between the sexes. Second, whereas positive values of the univariate quantity only hinder positive changes in sexual dimorphism, positive covariances in the intersexual covariance B matrix can either help or hinder. Similarly, the handful of studies reporting B matrices indicate that it is often asymmetric, so that B can affect the evolution of single traits differently between the sexes. Multivariate approaches typically demonstrate that genetic covariances among traits can strongly constrain trait evolution when compared with univariate approaches. By contrast, in the evolution of sexual dimorphism, a multivariate view potentially reveals more opportunities for sexual dimorphism to evolve by considering the effect sex‐specific selection has on sex‐specific G matrices and an asymmetric B matrix.
Multiple infections, kin selection and the evolutionary epidemiology of parasite traits
Authors: Lion S.
Published: September 2013

The coinfection of a host by several parasite strains is known to affect selective pressures on parasite strategies of host exploitation. I present a general model of coinfections that ties together kin selection models of virulence evolution and epidemiological models of multiple infections. I derive an analytical expression for the invasion fitness of a rare mutant in a population with an arbitrary distribution of the multiplicity of infection (MOI) across hosts. When a single mutation affects parasite strategies in allMOIclasses, I show that the evolutionarily stable level of virulence depends on a demographic average of within‐host relatedness across all host classes. This generalization of previous kin selection results requires that within‐host parasite densities do not vary between hosts. When host exploitation strategies are allowed to vary across classes, I show that the strategy of host exploitation in a focalMOIclass depends on the relative magnitudes of parasite reproductive values in the focal class and in the next. Thus, in contrast to previous findings, lower within‐host relatedness in competitive parasite interactions can potentially correspond to either higher or lower levels of virulence.
Modified Atmosphere Container with Time‐Controlled Gas‐Diffusion Tube for Preserving Fresh Produce
Authors: Kwon Min‐Ji , An Duck Soon , Lee Dong Sun
Published: September 2013

The concept of a fresh produce container equipped with a time‐controlled gas‐diffusion tube was proposed and tested for its effectiveness at modifying the internal atmosphere of the container beneficially, thus preserving the quality of stored spinach. The time‐controlled closing/opening of the properly dimensioned diffusion tube was shown to be useful in attaining a modified atmosphere (MA), which is helpful for quality preservation. A mathematical model of the mass balance of gases in the container, taking care of diffusive gas fluxes through the plastic wall and the tube, convective hydraulic gas flow through the tube and produce respiration, was adopted from the literature and constructed to estimate the gas composition under a variety of design and operation variables, enabling optimization of the system. Cycle time did not affect the averaged container atmosphere at equilibrium, but it did affect the fluctuation levels of the gas composition. Functional relationships between the spinach container atmosphere (i.e., O2 and CO2 concentrations) and independent control variables (i.e., tube dimensions and closed time ratio) were formulated and used to find a container design that gives an MA in the optimal window. A designed prototype container was able to give an optimal MA in agreement with design estimates and offer better spinach quality than the perforated control package, thus verifying the concept and model proposed.

Practical Applications

A time‐controlled opening of gas‐diffusion tube is an innovative concept to attain a desired MA in a fresh produce container. The time‐controlled opening/closing of a properly dimensioned diffusion tube can be programmed using mathematical modeling to attain an MA that is conducive to the produce quality. Proper combination of the closed time ratio and tube dimension yielding the optimal atmosphere of O2 and CO2 concentrations can be found by the approach given in this study. Use of the developed concept can be applied to the reusable containers or packages keeping the product quality and extending the shelf life in the produce supply chain.
Reclassification of captive chimpanzees as endangered would cost lives
Authors: VandeBerg John L.
Published: September 2013

A reclassification of captive chimpanzees as endangered by the US Fish and Wildlife Service (FWS) would have devastating consequences on critical areas of basic biomedical research for which chimpanzees are uniquely suitable as animal models. It also would have a negative impact on the survival of wild chimpanzees and the preservation of the species.
Seasonality of oestrus, ovulation and ovulation rate of Sicilo‐Sarde sheep
Authors: Lassoued N. , Rekik M. , Khenissi S. , Merai A.
Published: September 2013

This study aimed to investigate monthly changes in oestrus and ovulatory activity of Sicilo‐Sarde sheep. Experimental animals comprised 25 adult and 10 maiden ewes at the start of the experiment. For 12 consecutive months (September–August), the females were exposed to natural photoperiod and permanently kept in presence of seven aproned rams. Oestrus was checked daily and ovarian activity was monitored by monthly endoscopies during the last week of each month. Ovulation rate for a particular month was assessed as the sum of corpora lutea or corpora albicans present on both ovaries at the time of endoscopy. Proportions of ewes observed in oestrus at least once a month were lowest in March (24.3%) and highest in June and October (100%). They tended (p < 0.06) to be different according to age, dropping during summer from a common value of 100% in June to 85.7% and 90% in July and then to 57.1% and 70% in August for, respectively, the Adults and Maiden females. Overall, the experimental period, 92.5% and 83.8% of Adult and Maiden ewes ovulated at least once per month (p < 0.01) respectively. Least proportions ovulating, attained 60% and 30% in April for, respectively, Adult and Maiden ewes before peaking up at 100% again in May (p < 0.05). Mean (±SD) ovulation rate of Sicilo‐Sarde sheep is 1.40 ± 0.503. Adult females had a higher (p < 0.001) ovulation rate than Maiden sheep with respective average values of 1.51 ± 0.516 and 1.16 ± 0.373. It varied little between months and decreased in Adults from a maximum value of 1.95 in October to a minimum value of 1.16 in April. It is concluded that benchmarking seasonal variations of reproductive activity in Sicilo‐Sarde breed would be valuable in designing improved management calendars for this breed.
High Patient Satisfaction After Inflatable Penile Prostheses Implantation Correlates with Female Partner Satisfaction
Authors: Vakalopoulos Ioannis , Kampantais Spyridon , Ioannidis Stavros , Laskaridis Leonidas , Dimopoulos Panagiotis , Toutziaris Chrysovalantis , Koptsis Michail , Henry Gerard D. , Katsikas Vasileios
Published: September 2013

Introduction

Patient and female partner satisfaction after implantation of an inflatable penile prosthesis (IPP) assessed by objective means, and the correlation between the partners, is important for determining postoperative sexual life.

Aim

The primary goal was to evaluate patients' erectile function and patients' and their partners' satisfaction after IPP implantation. A secondary aim was to investigate potential determinative factors of satisfaction according to device characteristics, demographics, and cause of erectile dysfunction (ED).

Methods

Ninety patients, who underwent IPP implantation as an alternative to refractory or undesirable medical treatment for ED, were evaluated. Patients who could not or refused to participate, or were out of a relationship, were excluded. The 69 remaining patients were evaluated for their pre- and postoperative erectile function and posttreatment satisfaction for themselves and their partners.

Main Outcome Measures

Preoperative and postoperative scores on the International Index of Erectile Function Questionnaire–five items (IIEF-5) were compared. The Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) was given to males and their female partners. Patient demographics, etiology of ED, and implant characteristics were correlated also with patients' EDITS scores.

Results

Mean IIEF-5 scores demonstrated a significant improvement after IPP implantation: from 8.88 ± 3.75 to 20.97 ± 4.37 (P < 0.001). The mean patients' EDITS score was 75.48 ± 20.54, whereas mean female partners' score was 70.00 ± 22.92, highlighting high posttreatment satisfaction for both. Regression analysis suggested a direct linear correlation of satisfaction between the sexual partners as a degree of satisfaction. There were no statistically significant differences according to level of education or implant characteristics. Concerning the etiology of ED, no conclusions could be made.

Conclusions

Overcoming previous limitations in determining post-IPP implantation satisfaction, our study reiterates high rates of patient and partner satisfaction. Of particular note, patient satisfaction appears independent of prosthesis type and cylinder length.
Are habitat fragmentation, local adaptation and isolation‐by‐distance driving population divergence in wild rice Oryza rufipogon?
Authors: Zhao Yao , Vrieling Klaas , Liao Hui , Xiao Manqiu , Zhu Yongqing , Rong Jun , Zhang Wenju , Wang Yuguo , Yang Ji , Chen Jiakuan , Song Zhiping
Published: September 2013

Habitat fragmentation weakens the connection between populations and is accompanied with isolation by distance (IBD) and local adaptation (isolation by adaptation, IBA), both leading to genetic divergence between populations. To understand the evolutionary potential of a population and to formulate proper conservation strategies, information on the roles of IBD and IBA in driving population divergence is critical. The putative ancestor of Asian cultivated rice (Oryza sativa) is endangered in China due to habitat loss and fragmentation. We investigated the genetic variation in 11 Chinese Oryza rufipogon populations using 79 microsatellite loci to infer the effects of habitat fragmentation, IBD and IBA on genetic structure. Historical and current gene flows were found to be rare (mh = 0.0002–0.0013, mc = 0.007–0.029), indicating IBD and resulting in a high level of population divergence (FST = 0.343). High within‐population genetic variation (HE = 0.377–0.515), relatively large effective population sizes (Ne = 96–158), absence of bottlenecks and limited gene flow were found, demonstrating little impact of recent habitat fragmentation on these populations. Eleven gene‐linked microsatellite loci were identified as outliers, indicating local adaptation. Hierarchical AMOVA and partial Mantel tests indicated that population divergence of Chinese O. rufipogon was significantly correlated with environmental factors, especially habitat temperature. Common garden trials detected a significant adaptive population divergence associated with latitude. Collectively, these findings imply that IBD due to historical rather than recent fragmentation, followed by local adaptation, has driven population divergence in O. rufipogon.
The exception proves the rule? Dual targeting of nuclear‐encoded proteins into endosymbiotic organelles
Authors: Baudisch Bianca , Langner Uwe , Garz Ingo , Klösgen Ralf Bernd
Published: September 2013

Plant cells harbor two types of endosymbiotic organelle: mitochondria and chloroplasts. As a consequence of endosymbiotic gene transfer, the majority of their proteins are encoded in the nucleus and post‐translationally ‘re’‐imported into the respective target organelle. The corresponding transport signals are usually selective for a single organelle, but several proteins are transported into both the mitochondria and chloroplasts.

To estimate the number of proteins with such dual targeting properties in Arabidopsis, we classified the proteins encoded by nuclear genes of endosymbiotic origin according to the respective targeting specificity of their N‐terminal transport signals as predicted by the TargetP software package. Selected examples of the resulting protein classes were subsequently analyzed by transient transformation assays as well as by in organello protein transport experiments.

It was found that most proteins with high prediction values for both organelles show dual targeting with both experimental approaches. Unexpectedly, however, dual targeting was even found among those proteins that are predicted to be localized solely in one of the two endosymbiotic organelles. In total, among the 16 candidate proteins analyzed, we identified 10 proteins with dual targeting properties.

This unexpectedly high proportion suggests that such transport properties are much more abundant than anticipated.
Reading Ornament
Authors: Dembeck Till
Published: September 2013

This paper puts the most fundamental philological operation into the center of the theory of culture: the seemingly trivial act of recognizing the shape of a letter in the “ornamental” abundance of the material text. Culture is described as a comprehensive term for all mechanisms, which interrelate social events with their “scripts,” that is to say, with their proto‐textual foundations. Culture continuously, but variably, determines what is actually significant in the potential ornaments of “social text.” The common quest of philology and cultural studies is to re‐evaluate this text's seemingly ornamental details and to uncover their significance. In order to reunite these only seemingly oppositional approaches, literary scholarship must put genuinely philological operations in the center of its methodological repertoire.
A 1‐year prospective analysis of injuries in amateur and elite fistball
Authors: Runer A. , Runer F. , Neunhäuserer D. , Ring‐Dimitriou S. , Resch H. , Moroder P.
Published: September 2013

The purpose of this study was to examine the incidence and mechanisms of acute injuries in the sport of fistball. No scientific studies on injury characteristics have yet been conducted in this traditional sport game. The study was conducted prospectively over the course of 12 months. During a total of 40.308 h of sport‐specific exposure, 240 players reported 492 injuries, representing an overall injury rate of 12.2 injuries/1000 h of exposure. Most injuries were classified as bagatelle injuries (67.8%). The majority of the injuries were located in the knee (23.5%) followed by the elbow (11.9%) and the hip (11.5%). Ankle injuries resulted in the longest impairment from sports participation. The most common types of injury were abrasions (38.2%), contusions (21.1%), distortions (7.5%) and muscle strains (6.9%). Wrong or insufficient equipment (15.0%) was the most commonly mentioned causes of injury. The data indicate that the injury risk in fistball is rather high; however, the sport should not be considered a high‐risk sport because most of the injuries are slight and do not prevent the players from training or competition. Injury prevention strategies should include the development of fistball‐specific protective equipment with focus on the knee and elbow joint.
Increased mortality rate and suicide in Swedish former elite male athletes in power sports
Authors: Lindqvist A‐S. , Moberg T. , Ehrnborg C. , Eriksson B. O. , Fahlke C. , Rosén T.
Published: September 2013

Physical training has been shown to reduce mortality in normal subjects, and athletes have a healthier lifestyle after their active career as compared with normal subjects. Since the 1950s, the use of anabolic androgenic steroids (AAS) has been frequent, especially in power sports. The aim of the present study was to investigate mortality, including causes of death, in former Swedish male elite athletes, active 1960–1979, in wrestling, powerlifting, Olympic lifting, and the throwing events in track and field when the suspicion of former AAS use was high. Results indicate that, during the age period of 20–50 years, there was an excess mortality of around 45%. However, when analyzing the total study period, the mortality was not increased. Mortality from suicide was increased 2–4 times among the former athletes during the period of 30–50 years of age compared with the general population of men. Mortality rate from malignancy was lower among the athletes. As the use of AAS was marked between 1960 and 1979 and was not doping‐listed until 1975, it seems probable that the effect of AAS use might play a part in the observed increased mortality and suicide rate. The otherwise healthy lifestyle among the athletes might explain the low malignancy rates.
Time‐geographic Derivation of Feasible Co‐presence Opportunities from Network‐constrained Episodic Movement Data
Authors: Versichele Mathias , Neutens Tijs , Claeys Bouuaert Manuel , Van de Weghe Nico
Published: September 2013

Certain datasets on moving objects are episodic in nature – that is, the data is characterized by time gaps during which the position of the object is unknown. In this article, a model is developed to study the sparsely sampled network‐constrained movement of several objects by calculating both potential and feasible (i.e. more likely) co‐presence opportunities over time. The approach is applied to the context of a static sensor network, where the location of an object is only registered when passing a sensor location along a road network. Feasibility is incorporated based on the deviation from the shortest path. As an illustration, the model is applied to a large Bluetooth tracking dataset gathered at a mass event. The model output consists of maps showing the temporal evolution of the distribution of feasible co‐presence opportunities of tracked visitors over the network (i.e. the number of visitors that could have been present together). We demonstrate the model's usefulness in studying the movement and distribution of a crowd over a study area with relatively few sampling locations. Finally, we discuss the results with a special emphasis on the distinction between feasible and actual presence, the need for further validation and calibration, and the performance of the implementation.
Blood transfusion; additional historical aspects. Part 2. The introduction of chemical anticoagulants; trials of ‘Phosphate of soda’
Authors: Boulton F. E.
Published: September 2013

The pioneers of transfusion medicine around the turn of the 19th into the 20th centuries struggled with the awkward propensity of shed blood to clot. This article, a companion to a previous one (Boulton, 2013, Submitted for publication), describes in more detail how they recognised a potential for chemical anticoagulants which led to the introduction for a short period of sodium phosphate to aid blood transfusion: these cases preceded the introduction of citrate (Mollison, 2000, British Journal of Haematology, 108, 13–18).
Myocardial contusion and rib fracture repair in an adult horse
Authors: Peters Sarah T. , Hopkins Amber , Stewart Suzanne , Slack Joanne , de Solis Cristobal Navas
Published: September 2013

Objective

To describe the clinical findings and management of myocardial injury secondary to blunt thoracic trauma and rib fracture in an adult horse.

Case Summary

A 6‐year‐old Warmblood gelding presented for treatment of blunt thoracic trauma. Sonographic examination of the thorax revealed a complete, mildly comminuted fracture of the left 5th rib with a fragment overlying the left atrium and coronary artery, hemothorax, and subjective left ventricular dyskinesis. Evidence of myocardial injury included atrial fibrillation, ventricular ectopy, and increased plasma cardiac troponin I concentration. The rib fracture was repaired under general anesthesia using a wire and plate technique. The atrial fibrillation converted to normal sinus rhythm coincidentally with intraoperative local infusion of mepivicaine in administration of intercostal perineural analgesia. Continuous, resting, and exercising electrocardiograms, serial cardiac troponin I concentrations and echocardiograms were used to monitor the myocardial injury. The horse was discharged after 5 days of hospitalization. Reexaminations 3 and 15 months after the initial trauma showed healing of the fracture and no evidence of myocardial sequelae.

New or Unique Information Provided

To our knowledge, this is the first documentation of the diagnosis and monitoring of myocardial injury secondary to blunt thoracic trauma, as well as surgical repair of a rib fracture in an adult horse. Rib fractures and myocardial trauma can be successfully managed in adult horses and myocardial injury should be considered in cases of thoracic trauma.
Design, Analysis and Optimization of a Micro-CHP System Based on Organic Rankine Cycle for Ultralow Grade Thermal Energy Recovery
Authors: Ziviani Davide , Beyene Asfaw , Venturini Mauro
Published: September 2013

This paper presents the results of the application of an advanced thermodynamic model developed by the authors for the simulation of Organic Rankine Cycles (ORCs). The model allows ORC simulation both for steady and transient analysis. The expander, selected to be a scroll expander, is modeled in detail by decomposing the behavior of the fluid stream into several steps. The energy source is coupled with the system through a plate heat exchanger (PHE), which is modeled using an iterative sub-heat exchanger modeling approach. The considered ORC system uses solar thermal energy for ultralow grade thermal energy recovery. The simulation model is used to investigate the influence of ORC characteristic parameters related to the working medium, hot reservoir and component efficiencies for the purpose of optimizing the ORC system efficiency and power output. Moreover, dynamic response of the ORC is also evaluated for two scenarios, i.e. (i) supplying electricity for a typical residential user and (ii) being driven by a hot reservoir. Finally, the simulation model is used to evaluate ORC capability to meet electric, thermal and cooling loads of a single residential building, for typical temperatures of the hot water exiting from a solar collector.
Grid-Convergent Spray Models for Internal Combustion Engine Computational Fluid Dynamics Simulations
Authors: Senecal P. K. , Pomraning E. , Richards K. J. , Som S.
Published: September 2013

A state-of-the-art spray modeling methodology is presented. Key features of the methodology, such as adaptive mesh refinement (AMR), advanced liquid–gas momentum coupling, and improved distribution of the liquid phase, are described. The ability of this approach to use cell sizes much smaller than the nozzle diameter is demonstrated. Grid convergence of key parameters is verified for nonevaporating, evaporating, and reacting spray cases using cell sizes down to 1/32 mm. Grid settings are recommended that optimize the accuracy/runtime tradeoff for RANS-based spray simulations.
Three-Dimensional Solid Brick Element Using Slopes in the Absolute Nodal Coordinate Formulation
Authors: Olshevskiy Alexander , Dmitrochenko Oleg , Kim Chang-Wan
Published: September 2013

The present paper contributes to the field of flexible multibody systems dynamics. Two new solid finite elements employing the absolute nodal coordinate formulation are presented. In this formulation, the equations of motion contain a constant mass matrix and a vector of generalized gravity forces, but the vector of elastic forces is highly nonlinear. The proposed solid eight node brick element with 96 degrees of freedom uses translations of nodes and finite slopes as sets of nodal coordinates. The displacement field is interpolated using incomplete cubic polynomials providing the absence of shear locking effect. The use of finite slopes describes the deformed shape of the finite element more exactly and, therefore, minimizes the number of finite elements required for accurate simulations. Accuracy and convergence of the finite element is demonstrated in nonlinear test problems of statics and dynamics.
Development of a New Correlation of Gas Compressibility Factor (Z-Factor) for High Pressure Gas Reservoirs
Authors: Mahmoud Mohamed
Published: September 2013

Gas compressibility factor or Z-factor for natural gas system can be determined from Standing-Katz charts using the pseudocritical gas pressure and temperatures. These charts give accurate values for Z-factors. Reservoir simulation softwares need accurate correlations to estimate the values of Z-factor; one of the well-known correlations is Dranchuk and Abou-Kassem (DAK) Correlation. This correlation gives large errors at high gas reservoir pressures, this error could be more than 100%. The error in estimating Z-factor will lead to big error in estimating all the other gas properties such as gas formation volume factor, gas compressibility, and gas in place. In this paper a new accurate Z-factor correlation has been developed using regression for more than 300 data points of measured Z-factor using matlab in addition to other data points at low pressure and temperature from Standing-Katz charts and DAK correlation. Old correlations give good estimation of Z-factor at low gas reservoir pressures below 41.37 MPa (6000 psia), at high pressures the error started to appear. The developed correlation is a function of pseudoreduced pressure and temperature of the gas which makes it simpler than the existing complicated correlations. The new correlation can be used to determine the gas compressibility factor at any pressure range especially for high pressures the error was less than 3% compared to the measured data. The developed correlation is very simple to be used, it just needs the gas specific gravity that can be used to determine the pseudocritical properties of the gas and at last the Z-factor can be determined. A new formula of reduced gas compressibility was developed based on the developed Z-factor correlation which in turn can be used to determine the gas compressibility.
A Numerical Analysis of Hydrogen Underexpanded Jets Under Real Gas Assumption
Authors: Bonelli Francesco , Viggiano Annarita , Magi Vinicio
Published: September 2013

This work examines the fluid dynamic structure of underexpanded gas jets by using a high-performance computing (HPC) methodology in order to untangle the question of whether it is necessary to include the real gas assumption dealing with hydrogen jets. The answer to this question is needed in order to guarantee accurate numerical simulations of such jets in practical engineering applications, such as direct-injection hydrogen engines. An axial symmetric turbulent flow model, which solves the Favre-averaged Navier–Stokes equations for a multicomponent gas mixture, has been implemented and validated. The flow model has been assessed by comparing spreading and centerline property decay rates of subsonic jets at different Mach numbers with those obtained by both theoretical considerations and experimental measurements. Besides, the Mach disk structure of underexpanded jets has been recovered, thus confirming the suitability and reliability of the computational model. To take into account the effects of real gases, both van der Waals and Redlich–Kwong equations of state have been implemented. The analysis of a highly underexpanded hydrogen jet with total pressure equal to 75 MPa, issuing into nitrogen at 5 MPa, shows that the use of real gas equations of state affects significantly the jet structure in terms of temperature, pressure, and Mach number profiles along the jet centerline and also in terms of jet exit conditions, with differences up to 38%.
Control of Uncertain Nonlinear Multibody Mechanical Systems
Authors: Udwadia Firdaus E. , Wanichanon Thanapat
Published: September 2013

Descriptions of real-life complex multibody mechanical systems are usually uncertain. Two sources of uncertainty are considered in this paper: uncertainties in the knowledge of the physical system and uncertainties in the “given” forces applied to the system. Both types of uncertainty are assumed to be time varying and unknown, yet bounded. In the face of such uncertainties, what is available in hand is therefore just the so-called “nominal system,” which is our best assessment and description of the actual real-life situation. A closed-form equation of motion for a general dynamical system that contains a control force is developed. When applied to a real-life uncertain multibody system, it causes the system to track a desired reference trajectory that is prespecified for the nominal system to follow. Thus, the real-life system's motion is required to coincide within prespecified error bounds and mimic the motion desired of the nominal system. Uncertainty is handled by a controller based on a generalization of the concept of a sliding surface, which permits the use of a large class of control laws that can be adapted to specific real-life practical limitations on the control force. A set of closed-form equations of motion is obtained for nonlinear, nonautonomous, uncertain, multibody systems that can track a desired reference trajectory that the nominal system is required to follow within prespecified error bounds and thereby satisfy the constraints placed on the nominal system. An example of a simple mechanical system demonstrates the efficacy and ease of implementation of the control methodology.
Hybrid Optimization and Anti-Optimization of a Stochastically Excited Beam
Authors: Elishakoff Isaac , Dujat Kévin , Lemaire Maurice , Gadiot Guy
Published: September 2013

Random vibrations of the damped Bernoulli–Euler beam with two supports and subjected to a stationary random excitation are studied. The supports are symmetrically placed with respect to the middle cross-section of the beam. We investigate the mean square displacement of the beam with the goal of determining the optimum location of supports in order to minimize the maximum probabilistic response. This study falls in the category of hybrid optimization and anti-optimization, since we are looking for the worst maximum response, constituting the anti-optimization process; subsequently, we are looking for optimization of the structure to make the maximum response minimal by properly the spacing supports.
Improved Skeleton Tracking by Duplex Kinects: A Practical Approach for Real-Time Applications
Authors: Yeung Kwok-Yun , Kwok Tsz-Ho , Wang Charlie C. L.
Published: September 2013

Recent development of per-frame motion extraction method can generate the skeleton of human motion in real-time with the help of RGB-D cameras such as Kinect. This leads to an economic device to provide human motion as input for real-time applications. As generated by a single-view image plus depth information, the extracted skeleton usually has problems of unwanted vibration, bone-length variation, self-occlusion, etc. This paper presents an approach to overcome these problems by synthesizing the skeletons generated by duplex Kinects, which capture the human motion in different views. The major technical difficulty of this synthesis comes from the inconsistency of two skeletons. Our algorithm is formulated under the constrained optimization framework by using the bone-lengths as hard constraints and the tradeoff between inconsistent joint positions as soft constraints. Schemes are developed to detect and re-position the problematic joints generated by per-frame method from duplex Kinects. As a result, we develop an easy, cheap and fast approach that can improve the skeleton of human motion at an average speed of 5 ms per frame.
Analysis of Nonisothermal Deep Drawing of Aluminum Alloy Sheet With Induced Anisotropy and Rate Sensitivity at Elevated Temperatures
Authors: Ghavam Kamyar , Bagheriasl Reza , Worswick Michael J.
Published: September 2013

In this paper, a finite element model is developed for 3000 series clad aluminum alloy brazing sheet to account for temperature and strain rate dependency, as well as plastic anisotropy. The current work considers a novel implementation of the Barlat YLD2000 yield surface in conjunction with the Bergstrom hardening model to accurately model aluminum alloy sheet during warm forming. The Barlat YLD2000 yield criterion is used to capture the anisotropy while the Bergstrom hardening rule predicts the temperature and strain rate dependency. The results are compared with those obtained from experiments. The measured stress–strain curves of the AA3003 aluminum alloy sheet at elevated temperatures and different strain rates are used to fit the Bergstrom parameters and measured R-values and directional yield stresses are used to fit the yield function parameters. Isothermal uniaxial tensile tests and nonisothermal deep drawing experiments are performed and the predicted response using the new constitutive model is compared with measured data. In simulations of tensile tests, the material behavior is predicted accurately by the numerical models. Also, the nonisothermal deep drawing simulations are able to predict the load–displacement response and strain distributions accurately.
Active Shape Control and Phase Coexistence of Dielectric Elastomer Membrane With Patterned Electrodes
Authors: Zou Zhanan , Li Tiefeng , Qu Shaoxing , Yu Honghui
Published: September 2013

Various applications of dielectric elastomers (DEs) have been realized in recent years due to their lightweight, low cost, large actuation and fast response. In this paper, experiments and simulations are performed on the active shape control of DE structures with various two-dimensional patterned electrodes by applying voltage. A DE membrane with a pattern of electrodes is mounted on an air chamber. It is first inflated by air pressure and then further deformed by applying voltage, which actively controls the membrane shape. Under higher voltage, an acrylic membrane with larger actuation can induce shape instability and demonstrate multiphase coexistence behavior. In the framework of electromechanical theory, finite element simulations are carried out and the results are in good agreement with those obtained by experiments.
An Exergoeconomic Analysis of Hybrid Electric Vehicle Thermal Management Systems
Authors: Hamut H. S. , Dincer I. , Naterer G. F.
Published: September 2013

In this paper, exergy analysis of a hybrid electric vehicle thermal management system (TMS) is initially investigated in order to find the areas of inefficiencies and exergy destruction within each system component. In the analysis, advanced exergy modeling is utilized to study both endogenous/exogenous and avoidable/unavoidable exergy destructions for each component of the system and further understand the interactions among the TMS components and determine the underlying reasons behind the exergy destructions. Moreover, this approach is also used to enhance exergoeconomic analyses by calculating the endogenous/exogenous and avoidable/unavoidable portion of the investment and exergy destruction costs (so-called advanced exergoeconomic analysis) in order to improve the cost effectiveness of the system and provide information on how much of the cost can be avoided for each component. Based on the analysis, it is determined that exogenous exergy destruction is small but significant portion of the total exergy destruction in each component (up to 40%, in the chiller and thermal expansion valves) and that large portion of the exergy destruction within the components (up to 70%, in the compressor) could be potentially avoided. Moreover, it is determined that electric battery, compressor, and chiller are dominated by investment cost, whereas the condenser and evaporator are dominated by the cost of exergy destruction in the system.
Experimental Study of Solar Pond Coupled With Forced Circulation Crystallizer as Major Stages of Proposed Zero Discharge Desalination Process
Authors: Farahbod Farshad , Farahmand Sara
Published: September 2013

Pretreatment, solar pond (SP), and forced circulation crystallizer (FCC) are the basic stages of one option to provide the goals of zero discharge desalination (ZDD) process. This work represents the performance of a solar pond that is coupled with forced circulation crystallizer as second and third stages of proposed zero discharge desalination process. The purpose of ZDD in this paper is gathering fresh water and saline crystals from effluent wastewater of the desalination unit of Mobin petrochemical complex. So, the SP unit is constructed after the pretreatment unit to concentrate the treated wastewater to about 20 wt. % as a suited feed for the FCC unit. Effects of solar insolation rate are investigated experimentally, during a year. In addition, the effect of cooling water flow rate of FCC on quality of effluent stream from SP as feed crystallizer is studied in this paper. The experimental results show the maximum evaporation rate from SP is obtained 5 l/(m2·d) when the insolation rate was about 2.5 × 104 kJ/(m2·d). Experiments show the suitable range of crystals growth (710 μm to 830 μm) in FCC is occurred when the cooling water flow rate in condenser is 9 kg/min. The size and the color of produced salt crystals will be optimized in this flow rate and energy consumption is measured as 6.98 kW·h.
Measurements of sputtered neutrals and ions and investigation of their roles on the plasma properties during rf magnetron sputtering of Zn and ZnO targets
Authors: Maaloul L. , Stafford L.
Published: September 2013

Langmuir probe and optical absorption spectroscopy measurements were used to determine the line-integrated electron density, electron temperature, and number density of Ar atoms in metastable 3P2 and 3P0 levels in a 5 mTorr, rf magnetron sputtering plasmas used for the deposition of ZnO-based thin films. While the average electron energy and density of Ar atoms in 3P2 and 3P0 excited states were fairly independent of self-bias voltage, the Ar 3P2-to-electron number density ratio decreased by approximately a factor of 5 when going from −115 V to −300 V. This decrease was correlated to an increase by about one order of magnitude of the number density of sputtered Zn atoms determined by absolute actinometry measurements on Zn I using either Ar or Xe as the actinometer gas. These results were also found to be in excellent agreement with the predictions of a global model accounting for Penning ionization of sputtered Zn particles. The importance of the latter reactions was further confirmed by plasma sampling mass spectrometry showing a double peak structure for Zn ions: a low-energy component ascribed to thermalized ions created in the gas phase (by direct electron impact and by Penning ionization) and a high-energy tail due to ions ejected from the target and reaching quasi-collisionlessly the substrate surface.
Frequency of Resistance in Obligate Anaerobic Bacteria Isolated from Dogs, Cats, and Horses to Antimicrobial Agents
Authors: Lawhon S. D. , Taylor A. , Fajt V. R.
Published: September 2013

Clinical specimens from dogs, cats, and horses were examined for the presence of obligate anaerobic bacteria. Of 4,018 specimens cultured, 368 yielded 606 isolates of obligate anaerobic bacteria (248 from dogs, 50 from cats, and 308 from horses). There were 100 specimens from 94 animals from which only anaerobes were isolated (25 dogs, 8 cats, and 61 horses). The most common sites tested were abdominal fluid (dogs and cats) and intestinal contents (horses). The most common microorganism isolated from dogs, cats, and horses wasClostridium perfringens(75, 13, and101 isolates, respectively). The MICs of amoxicillin with clavulanate, ampicillin, chloramphenicol, metronidazole, and penicillin were determined using a gradient endpoint method for anaerobes. Isolates collected at necropsy were not tested for antimicrobial susceptibility unless so requested by the clinician. There were 1/145 isolates tested that were resistant to amoxicillin-clavulanate (resistance breakpoint ≥ 16/8 μg/ml), 7/77 isolates tested were resistant to ampicillin (resistance breakpoint ≥ 2 μg/ml), 4/242 isolates tested were resistant to chloramphenicol (resistance breakpoint ≥ 32 μg/ml), 12/158 isolates tested were resistant to clindamycin (resistance breakpoint ≥ 8 μg/ml), 10/247 isolates tested were resistant to metronidazole (resistance breakpoint ≥ 32 μg/ml), and 54/243 isolates tested were resistant to penicillin (resistance breakpoint ≥ 2 μg/ml). These data suggest that anaerobes are generally susceptible to antimicrobial drugsin vitro.
Clostridium difficile Genotypes in Piglet Populations in Germany
Authors: Schneeberg Alexander , Neubauer Heinrich , Schmoock Gernot , Baier Sylvia , Harlizius Jürgen , Nienhoff Hendrik , Brase Katja , Zimmermann Stefan , Seyboldt Christian
Published: September 2013

Clostridium difficile
was isolated from 147 of 201 (73%) rectal swabs of piglets from 15 farms of Lower Saxony and North Rhine-Westphalia. In 14 farms, 14 to 100% (mean, 78%) of the animals tested were culture positive. The rate of isolation was 68% postpartum, increased to 94% in animals 2 to 14 days of age, and declined to 0% for animals 49 days of age and older. There was no link between isolation and antibiotic treatment or diarrhea of piglets. Strains were assigned to 10 PCR ribotypes, and up to 4 PCR ribotypes were found to be present at the same time on a farm. The closely related PCR ribotypes 078 (55%) and 126 (20%) were most frequently recovered and were present in 13 of the 14 positive farms. The comparison of multilocus VNTR (variable number of tandem repeats) analysis (MLVA) data from this study and previously published data on human, porcine, and bovine PCR ribotype 078 isolates from 5 European countries revealed genetic differences between strains of different geographic origin and confirmed the relatedness of human and porcine
C. difficile
isolates. This study demonstrated that the human-pathogenic PCR ribotypes 078 and 126 are predominant in piglets in Germany. The results suggest that presence of
C. difficile
is correlated with animal age but not with antibiotic treatment or clinical disease. MLVA indicated that strains of the same geographical origin are often genetically related and corroborated the hypothesis of a close epidemiological connection between human and porcine
C. difficile
isolates.
Scopulariopsis, a Poorly Known Opportunistic Fungus: Spectrum of Species in Clinical Samples and
In Vitro
Responses to Antifungal Drugs
Authors: Sandoval-Denis Marcelo , Sutton Deanna A. , Fothergill Annette W. , Cano-Lira Josep , Gené Josepa , Decock C. A. , de Hoog G. S. , Guarro Josep
Published: September 2013

Ninety-nine isolates of clinical origin, tentatively identified as
Scopulariopsis
or
Microascus
, were morphologically and molecularly characterized by a combined analysis of the D1/D2 domains of the 28S rRNA gene and a fragment of the elongation factor 1-α gene (EF1-α) sequences. The most prevalent species was
Scopulariopsis brevicaulis
(49.4%), followed by
Scopulariopsis gracilis
(14.4%),
Scopulariopsis brumptii
(7.2%),
Microascus cinereus
(5.2%), the
Scopulariopsis candida
species complex (3.1%), and
Microascus cirrosus
(2.1%). The most common anatomic sites of isolation were the respiratory tract (61.6%), superficial tissue (19.2%), and deep tissue or fluid samples (19.2%). The antifungal susceptibilities of the isolates to eight drugs were tested
in vitro
, with all the drugs generally showing poor activity.