bluuebunny/crossref_metadata_2025 huggingface dataset:
Low‐Tilt Monophasic and Biphasic Waveforms Compared with Standard Biphasic Waveforms in the Transvenous Defibrillation of Ventricular Fibrillation
Authors: BENNETT JOHAN R. , DARRAGH KAREN M. , WALSH SIMON J. , ALLEN DESMOND J. , SCOTT MICHAEL , STEVENSON MICHAEL , ADGEY JENNIFER A.A. , ANDERSON JOHN M.C.J. , MANOHARAN GANESH
Published: October 2013

Background

Commercially available implantable defibrillators utilize a high‐tilt waveform. Studies in atrial fibrillation and transthoracic defibrillation of ventricular fibrillation (VF) have shown improved defibrillation efficacy using low‐tilt (LT) waveforms. We investigated the feasibility, efficacy, and safety of a LT waveform in the transvenous defibrillation of VF and hypothesized that it would be more efficacious than standard tilted biphasic (STB) waveforms.

Methods and Results

The investigation was performed in four phases in a porcine model: an efficacy study of LT monophasic waveforms (n = 9), an efficacy study of LT biphasic waveforms (n = 9), a comparison study between the most successful LT waveforms and clinically available STB waveforms (n = 15), and a safety study (n = 9). A total of 1,056 shocks were delivered (phase 1: 288, phase 2: 288, phase 3: 480). The LT biphasic 8/4‐ms waveform was significantly more likely to successfully defibrillate than the LT monophasic and STB waveforms with an odds ratio of 122.3 (95% confidence interval: 32.5, 460.2, P < 0.001). The calculated defibrillation threshold (E50) for the LT 8/4‐ms waveform was 12.7 J compared to 43.5 J and 45.5 J for STB waveforms 6/6 ms and 8/4 ms, respectively, and 47.7 J for LT 12‐ms waveform. The LT 8/4‐ms waveform had no lasting detrimental effect on cardiac function, and any transient hemodynamical or biochemical changes observed were comparable to those observed with STB waveforms.

Conclusion

LT waveforms are effective and appear safe in transvenous defibrillation in a porcine model of VF. The LT biphasic 8/4‐ms waveform is more efficacious than conventional waveforms.
A novel membrane‐bound E3 ubiquitin ligase enhances the thermal resistance in plants
Authors: Liu Zhi‐Bin , Wang Jian‐Mei , Yang Feng‐Xi , Yang Liang , Yue Yu‐Fei , Xiang Jun‐Bei , Gao Mei , Xiong Fang‐Jian , Lv Dong , Wu Xian‐Jun , Liu Ning , Zhang Xun , Li Xu‐Feng , Yang Yi
Published: October 2013

High temperature stress disturbs cellular homoeostasis and results in a severe retardation in crop growth and development. Thus, it is important to reveal the mechanism of plants coping with heat stress. In this study, a novel gene that we identified from Brassica napus, referred to as BnTR1, was found to play a key role in heat stress response in planta. BnTR1 is a membrane‐bound RINGv (C4HC3) protein that displays E3 ligase activity in vitro. We demonstrated that modest expression of BnTR1 is sufficient to minimize adverse environmental influence and confers thermal resistance on development without any detrimental effects in B. napus and Oryza sativa. Our investigation into the action mechanism indicates that BnTR1 is likely to be involved in mediating Ca2+ dynamics by regulating the activity of calcium channels, which further alters the transcripts of heat shock factors and heat shock proteins contributing to plant thermotolerance. Hence, our study identified BnTR1 as a novel key factor underlying a conserved mechanism conferring thermal resistance in plants.
Evaluation of a relapse‐prevention program for methamphetamine‐dependent inmates using a self‐teaching workbook and group therapy
Authors: Matsumoto Toshihiko , Imamura Fumi , Kobayashi Ohji , Wada Kiyoshi , Ozaki Shiro , Takeuchi Yoshio , Hasegawa Masahiko , Imamura Yoko , Taniya Yuko , Adachi Yasumori
Published: October 2013

Aim

The aim of this study was to evaluate the effect of a relapse‐prevention program for methamphetamine (MAP)‐dependent inmates in a prison.

Methods

Participants were 251 male inmates with MAP‐abuse problems. We compared scores on the Self‐efficacy Scale for Drug Dependence (SSDD) and the Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES) before and after intervention with a self‐teaching workbook and group therapy.

Results

For all participants, only SSDD scores increased during the pre‐intervention period. SOCRATES‐8D scores increased after the start of the intervention using the self‐teaching workbook, and both SSDD and SOCRATES‐8D scores increased when group therapy was implemented. Changes in scores in participants with moderate and high MAP dependence were considerably different from the scores of those with low dependence during the pre‐intervention and the self‐teaching workbook periods.

Conclusion

Intervention using a self‐teaching workbook and group therapy in prisons might be effective for inmates with more than moderate severity of MAP abuse.
Targeted photochemotherapy in alopecia areata
Authors: Açıkgöz Gürol , Yeşil Hakan , Çalışkan Ercan , Tunca Mustafa , Akar Ahmet
Published: October 2013

Background/Purpose

Alopecia areata (AA) is a common cause of localized non‐scarring alopecia. Usage of targeted UVA after the topical application of 8‐methoxypsoralen (8‐MOP) is one of the rising treatment modalities for AA. Our aim was to assess the efficacy and safety of topical 8‐MOP plus targeted UVA phototherapy in the treatment of patchy AA.

Methods

Seven patchy AA patients were treated by topical 8‐MOP application to the lesions followed by UVA irradiation 3 times a week, with 15 to 24 sessions in total. At the end of the treatment all patients were evaluated for response on a four‐point scale (0 = no hair, 1 = white vellus hair, 2 = regrowth cosmetically acceptable for the patient, 3 = complete hair growth).

Results

The mean cumulative UVA dose was from 7.5 to 39.6 J/cm2. For all 7 patients, average response score was calculated as 2, which means cosmetically acceptable regrowth.

Conclusion

Targeted UVA phototherapy combined with topical 8‐MOP may be an effective and safe alternative treatment protocol for patchy AA, which should be kept in mind in order to choose the best for the patient, especially for patients incompatible with other treatments that are systemic and invasive.
Costs and benefits of hormone‐regulated plant defences
Authors: Vos I. A. , Pieterse C. M. J. , van Wees S. C. M.
Published: October 2013

Plants activate defence responses to protect themselves against microbial pathogens and herbivorous insects. However, induction of defences comes at a price, as the associated allocation costs, autotoxicity costs and ecological costs form fitness penalties. Upon pathogen or insect attack, resources are allocated to defences instead of to plant growth and reproduction, while above‐ and below‐ground interactions with beneficial organisms may also be disturbed. The phytohormones salicylic acid and jasmonic acid are major players in the regulation of induced defences and their associated fitness costs. Hormone‐controlled signalling pathways cross‐communicate, providing the plant with a finely tuned defence regulatory system that can contribute to a reduction of fitness costs by repressing ineffective defences. However, this sophisticated regulatory system causes ecological costs, because activated resistance to one organism can suppress resistance to another. Moreover, the system can be hijacked by invading organisms that manipulate it for their own benefit. Priming for enhanced defence emerged as a defence mechanism with limited fitness costs. Because priming results in a faster and stronger activation of defence only after pathogen or insect attack, the limited costs of the primed state are often outweighed by the benefits in environments with pathogen or herbivore pressure. The balance between protection and fitness is crucial for a plant's success and is therefore of great interest for plant breeders and farmers. By combining molecular knowledge and ecological relevance of defence mechanisms, one can gain fundamental insight into how and why plants integrate different immune signals to cope with their natural multitrophic environment in a cost‐effective manner.
Reactive oxygen species modulate the differential expression of methionine sulfoxide reductase genes in Chlamydomonas reinhardtii under high light illumination
Authors: Chang Hsueh‐Ling , Tseng Yu‐Lu , Ho Kuan‐Lin , Shie Shu‐Chiu , Wu Pei‐Shan , Hsu Yuan‐Ting , Lee Tse‐Min
Published: October 2013

Illumination of Chlamydomonas reinhardtii cells at 1000 (high light, HL) or 3000 (very high light, VHL) µmol photons m−2 s−1 intensity increased superoxide anion radical (O2•–) and hydrogen peroxide (H2O2) production, and VHL illumination also increased the singlet oxygen (1O2) level. HL and VHL illumination decreased methionine sulfoxide reductase A4 (CrMSRA4) transcript levels but increased CrMSRA3, CrMSRA5 and CrMSRB2.1 transcripts levels. CrMSRB2.2 transcript levels increased only under VHL conditions. The role of reactive oxygen species (ROS) on CrMSR expression was studied using ROS scavengers and generators. Treatment with dimethylthiourea (DMTU), a H2O2 scavenger, suppressed HL‐ and VHL‐induced CrMSRA3, CrMSRA5 and CrMSRB2.1 expression, whereas H2O2 treatment stimulated the expression of these genes under 50 µmol photons m−2 s−1 conditions (low light, LL). Treatment with diphenylamine (DPA), a 1O2 quencher, reduced VHL‐induced CrMSRA3, CrMSRA5 and CrMSRB2.2 expression and deuterium oxide, which delays 1O2 decay, enhanced these gene expression, whereas treatment with 1O2 (rose bengal, methylene blue and neutral red) or O2•– (menadione and methyl viologen) generators under LL conditions induced their expression. DPA treatment inhibited the VHL‐induced decrease in CrMSRA4 expression, but other ROS scavengers and ROS generators did not affect its expression under LL or HL conditions. These results demonstrate that the differential expression of CrMSRs under HL illumination can be attributed to different types of ROS. H2O2, O2•– and 1O2 modulate CrMSRA3 and CrMSRA5 expression, whereas H2O2 and O2•– regulate CrMSRB2.1 and CrMSRB2.2 expression, respectively. 1O2 mediates the decrease of CrMSRA4 expression by VHL illumination, but ROS do not modulate its decrease under HL conditions.
Methods for Equine Preantral Follicles Isolation: Quantitative Aspects
Authors: Leonel ECR , Bento‐Silva V , Ambrozio KS , Luna HS , Costa e Silva EV , Zúccari CESN
Published: October 2013

Contents

The aim of this study was to test the use of mechanical and mechanical‐enzymatic methods, saline solution (SS), and PBS solution for the manipulation and isolation of mare ovarian preantral follicles (PAFs). The ovaries were subjected to mechanical isolation (mixer) alone or in association with enzymatic digestion (collagenase). Incubation times of 10 and 20 min were employed. In the first group, 4.1 ± 4.9 PAFs were harvested with the mechanical‐enzymatic method vs 71.1 ± 19.2 with the mechanical procedure, showing a significant difference between methods; using SS and PBS, these numbers were 35.7 ± 34.3 and 39.6 ± 39.6, respectively, with no significant difference between solutions. In the second group, there was significant difference between methods, with 7.1 ± 10.6 follicles harvested with the mechanical‐enzymatic method vs 63.2 ± 22.9 with the mechanical procedure; using SS and PBS, means were 35.5 ± 36.4 and 34.9 ± 31.1, respectively. The mechanical method proved more effective than the mechanical‐enzymatic approach. Both SS and PBS can be used as a media for equine PAFs preparation.
Acquired hypogammaglobulinemia in HIV‐positive subjects after liver transplantation
Authors: Gregg K.S. , Barin B. , Pitrak D. , Ramaprasad C. , Pursell K.
Published: October 2013

Introduction

As more solid organ transplantations are performed in patients infected with human immunodeficiency virus (HIV), post‐transplant complications in this population are becoming better defined.

Methods

Using serum samples from the Solid Organ Transplantation in HIV: Multi‐Site Study, we studied the epidemiology of acquired hypogammaglobulinemia (HGG) after liver transplantation (LT) in 79 HIV‐infected individuals with a median CD4 count at enrollment of 288 (interquartile range 200–423) cells/μL. Quantitative immunoglobulin G (IgG) levels before and after LT were measured, with moderate and severe HGG defined as IgG 350–500 mg/dL and <350 mg/dL, respectively. Incidence, risk factors, and associated outcomes of moderate or worse HGG were evaluated using Kaplan–Meier estimator and proportional hazards (PH) models.

Results

The 1‐year cumulative incidence of moderate or worse HGG was 12% (95% confidence interval [CI]: 6–22%); no new cases were observed between years 1 and 2. In a multivariate PH model, higher pre‐transplant model for end‐stage liver disease score (P = 0.04) and treated acute rejection (P = 0.04) were both identified as significant predictors of moderate or worse HGG. There was a strong association of IgG levels <500 mg/dL with non‐opportunistic serious infection (hazard ratio [95% CI]: 3.5 [1.1–10.6]; P = 0.03) and mortality (3.2 [1.1–9.4]; P = 0.04). These associations held after adjustment for important determinants of infection and survival among the entire cohort.

Conclusion

These results suggest that a proportion of HIV‐positive LT recipients will develop clinically significant HGG after transplantation.
Non‐cervical human papillomavirus‐related disease
Authors: Lippiatt Jonathan , Powell Ned , Tristram Amanda
Published: October 2013

Key content

Human papillomavirus (HPV) is associated with neoplastic disease at sites other than the cervix.

Cancer caused by HPV may behave differently to other cancers at the same site.

The presence of HPV alone is not sufficient to demonstrate a causal association.

HPV vaccination has the potential to impact on disease burden beyond cervical cancer.

Learning objectives

To understand the spectrum of disease caused by HPV.

To review the management of HPV‐associated disease in pregnancy.

To be aware that future research into HPV‐related disease may alter management.

Ethical issues

What advice should women be given regarding their sexual partners?

Should boys be offered HPV vaccination?
Loss‐of‐function of OsSTN8 suppresses the photosystem II core protein phosphorylation and interferes with the photosystem II repair mechanism in rice (Oryza sativa)
Authors: Nath Krishna , Poudyal Roshan Sharma , Eom Joon‐Seob , Park Yu Shin , Zulfugarov Ismayil S. , Mishra Sujata R. , Tovuu Altanzaya , Ryoo Nayeoon , Yoon Ho‐Sung , Nam Hong Gil , An Gynheung , Jeon Jong‐Seong , Lee Choon‐Hwan
Published: October 2013

STN8 kinase is involved in photosystem II (PSII) core protein phosphorylation (PCPP). To examine the role of PCPP in PSII repair during high light (HL) illumination, we characterized a T–DNA insertional knockout mutant of the rice (Oryza sativa) STN8 gene. In this osstn8 mutant, PCPP was significantly suppressed, and the grana were thin and elongated. Upon HL illumination, PSII was strongly inactivated in the mutants, but the D1 protein was degraded more slowly than in wild‐type, and mobilization of the PSII supercomplexes from the grana to the stromal lamellae for repair was also suppressed. In addition, higher accumulation of reactive oxygen species and preferential oxidation of PSII reaction center core proteins in thylakoid membranes were observed in the mutants during HL illumination. Taken together, our current data show that the absence of STN8 is sufficient to abolish PCPP in osstn8 mutants and to produce all of the phenotypes observed in the double mutant of Arabidopsis, indicating the essential role of STN8‐mediated PCPP in PSII repair.
Respiratory arrest following ingestion of wild mushrooms in 3 dogs (2006–2011)
Authors: Brandin Anna C. , Meola Stacy D. , Mazzaferro Elisa M.
Published: October 2013

Objective

To describe the clinical course, treatment, and outcome of 3 dogs with respiratory arrest following mushroom ingestion.

Case Series Summary

Three dogs were presented for mushroom toxicosis that developed respiratory arrest. Two of the dogs were treated with diazepam just prior to the development of respiratory arrest; 1 dog received no medications prior to respiratory arrest. Of the 3 dogs, 1 was euthanized and the remaining 2 recovered fully with assisted and mechanical ventilation.

New or Unique Information Provided

This is the first documentation of respiratory arrest associated with mushroom toxicosis in dogs.
Emergency visits and occupational hazards inGermanShepherd police dogs (2008–2010)
Authors: Parr Joanna R. , Otto Cynthia M.
Published: October 2013

Objective

To describe the most common reasons for emergency medical visits in working police dogs.

Design

Retrospective case control study.

Animals

Two hundred threeGermanShepherd dogs (GSDs); 138 police dog visits by 74 dogs and 138 pet (control) dog visits by 129 dogs.

Procedures

Medical records of allGSDs seen in the emergency service (ES) at theUniversity ofPennsylvaniaVeterinaryHospital from July 2008 to July 2010 were reviewed. The recorded diagnoses from policeGSD ESvisits (defined as a new problem or new episode of a recurrent problem) were compared to those of randomly chosen petGSD ESvisits.

Results

There were significantly more intact male policeGSDs than petGSDs. PoliceGSDs were significantly younger than petGSDs. The most common presenting complaint in both groups was gastrointestinal disease (eg, vomiting, diarrhea, gastric dilatation and volvulus). PetGSDs were significantly more likely to present for geriatric conditions (eg, central nervous system disease, cardiovascular disease, and neoplastic conditions). Orthopedic issues were significantly more common in policeGSDs.

Conclusions and Clinical Relevance

PoliceGSDs are more likely to present for orthopedic injuries and less likely to present for geriatric diseases. Gastrointestinal disease is not unique to the workingGSDand was equally represented in both populations. Preventative measures for allGSDs should focus on minimizing gastrointestinal disease. Preventive strategies focusing on physical fitness and conditioning as well as selective breeding programs may help reduce orthopedic injuries in policeGSDs.
Aerodynamic Study of a Tricycle Wheel Subsystem for Drag Reduction
Authors: Driant Thomas , Remaki Lakhdar , Fellouah Hachimi , Moreau Stéphane , Desrochers Alain
Published: October 2013

This paper deals with a computational fluid dynamics (CFD) and experimental drag analysis on an isolated rotating wheel subsystem (including its accessories: tire, suspension, A-arms, and fender) of a motor tricycle vehicle with two wheels in front. The main goal of the present work is to study the effect of the fender on the wheel subsystem drag and its optimization. The Star CCM+ commercial code was used for the numerical simulations. Different flow conditions were simulated and some results were validated by comparison to wind tunnel experimental results. To perform drag optimization, several aerodynamic fender shapes were designed and simulated as part of the subsystem. A drastic drag reduction up to 30.6% compared to the original wheel subsystem was achieved through numerical simulations.
Numerical Modeling and Validation of Supersonic Two-Phase Flow of CO2 in Converging-Diverging Nozzles
Authors: Yazdani Miad , Alahyari Abbas A. , Radcliff Thomas D.
Published: October 2013

Carbon dioxide is an attractive alternative to conventional refrigerants due to its low direct global warming effects. Unfortunately, CO2 and many alternative refrigerants have lower thermodynamic performance resulting in larger indirect emissions. The effective use of ejectors to recover part of the lost expansion work, which occurs in throttling devices, can close this performance gap and enable the use of CO2. In an ejector, the pressure of the motive fluid is converted into momentum through a choked converging-diverging nozzle, which then entrains and raises the energy of a lower-momentum suction flow. In a two-phase ejector, the motive nozzle flow is complicated by the nonequilibrium phase change affecting local sonic velocity and leading to various types of shockwaves, pseudo shocks, and expansion waves inside or outside the exit of the nozzle. Since the characteristics of the jet leaving the motive nozzle greatly affect the performance of the ejector, this paper focuses on the details of flow development and shockwave interaction within and just outside the nozzle. The analysis is based on a high-fidelity model that incorporates real-fluid properties of CO2, local mass and energy transfer between phases, and a two-phase sonic velocity model in the presence of finite-rate phase change. The model has been validated against the literature data for two-phase supersonic nozzles and overall ejector performance data. The results show that due to nonequilibrium effects and delayed phase change, the flow can choke well downstream of the minimum-area throat. In addition, Mach number profiles show that, although phase change is at a maximum near the boundaries, the flow first becomes supersonic in the interior of the flow where sound speed is lowest. Shock waves occurring within the nozzle can interact with the boundary layer flow and result in a ‘shock train’ and a sequence of subsonic and supersonic flow previously observed in single-phase nozzles. In cases with lower nozzle back pressure, the flow continues to accelerate through the nozzle and the exit pressure adjusts in a series of supersonic expansion waves.
Forensic Engineering Analysis of Ejected Cartridge Case Patterns for the Reconstruction of Firearms-Related Incidents
Authors: Knox Michael A.
Published: October 2013

Firearms-related incidents present an important area of study for forensic engineers. Analysis of bullet trajectories, examination of firearms failures, and the study of wound dynamics and projectile injuries are some of the topics to which the forensic engineer can offer valuable knowledge and insight for the purpose of reconstructing a shooting incident in a forensic context.

One specific topic of study that forensic engineers engaging in the reconstruction of firearms-related incidents should clearly understand is the nature and distribution of ejected cartridge case patterns left at a crime scene after the discharge of semi-automatic firearms. While studies have been conducted into the effects that firearm design, ammunition, grip, stance, and movement have on the distribution of ejected cartridge cases, few, if any, of these studies have involved any type of engineering analysis.

This paper will address the nature of engineering analysis applicable to the distribution of ejected cartridge cases at a crime scene by specifically addressing mechanical issues related to the design and maintenance of the firearm itself, the flight characteristics of ejected cartridge cases, and the restitution of cartridge cases that collide with intermediary objects.

Experimental results will be presented, and testing methodologies will be discussed. Methods for simulating cartridge case ejection patterns based on testing data using Monte Carlo methods will be covered. Application of testing data and simulation to actual casework will be demonstrated.
Effect of Cutting Parameters on Surface Roughness When Milling Hardened AISI D2 Steel (56 HRC) Using Taguchi Techniques
Authors: Shammari Ahmed Zaidan Mohammed , Amwead Kamal Ati , Hadi Auday Shaker
Published: October 2013

The tool steel identifying AISI D2 is commonly used for cold working operations, such as sheet metal forming, cold extrusion and forging operation. To perform in these applications, they must have excellent strength, hardness, and wear resistance. The aim of the present study is to find optimal process parameters for end milling of hardened steel AISI D2 (56 HRC) using Taguchi method. A L25 array, Taguchi’s signal-to-noise ratio and ANOVA are employed to determine effects of many control factors (spindle speed, feed rate, and depth of cut) on surface roughness. In this paper, results show that the spindle speed is most influencing parameters.
Automated Procedures for Robust and Efficient Solution of Over-Constrained Multibody Dynamics
Authors: Wehage Roger A.
Published: October 2013

The basic steps of a computer-based methodology that generates optimized runtime algorithms to achieve robust, stable, and efficient solution of constrained, multibody dynamics are summarized. The concept of using processors operating in the background to improve many aspects of an executing program’s performance on arbitrary models is introduced. Among the many optimizing tasks, algorithm processors extract model topology from body and joint descriptions, set up recursive spatial kinematics and generalized dynamics algorithms, block-partition constraints and apply Gaussian elimination with complete pivoting to identify and change dependent and independent variable sets, convert constraints into row-reduced, echelon form, permute the constrained generalized equations to achieve stable and efficient solutions, and set up recursive sparse uncoupling and solve algorithms to minimize fills and operations count. To accomplish these tasks, processors assess model-specific algorithm requirements and use this information to generate source and destination memory pointer arrays and arrays of pointers to structures and optimized functions. In essence, they wire and rewire runtime algorithms as needed to maintain robust, stable, and efficient solutions throughout a simulation.
The Use of Non-Dimensional Parameters to Study Stress in Lithium-Ion Battery Electrode Storage Particles
Authors: Purkayastha Rajlakshmi T. , McMeeking Robert M.
Published: October 2013

Mechanical degradation is thought to be one of the causes of capacity fade within Lithium-Ion batteries. In this work we develop a coupled stress-diffusion model for idealized spherical storage particles, which is analogous to the development of thermal strains. We then non-dimensionalize the model and identify three important parameters that control the development of stress within these particles. We can therefore use a wide number of values for these parameters to make predictions about the stress responses of different materials. The maximum stress developed within the particle for different values of these parameters are plotted as stress maps. A two dimensional model of a battery was then developed, in order to study the effect of particle morphology.
The Dynamics of Plug Zones in Elasto-Plastic Flows in Unsteady Flow in Circular Tubes
Authors: Letelier Mario F. , Siginer Dennis A. , Ahumada Juan L. , Stockle Juan S.
Published: October 2013

Purely oscillatory flow of an elasto-plastic fluid in round tubes is analyzed. A combined linear Maxwell-Bingham model is used to characterize the fluid behavior.
Critical Entropy Threshold: An Irreversible Thermodynamic Theory of Fatigue
Authors: Whaley P. W.
Published: October 2013

A theoretical model for material fatigue is described using irreversible thermodynamics to quantify fatigue damage by the generation of microplastic entropy. The microplastic entropy generated quantifies the microplastic deformation, commonly accepted as the mechanism of fatigue damage in polycrystalline materials. A stochastic model for microplastic deformation is utilized to calculate the expected values of tensile stress–strain, cyclic stress–strain, microplastic strain energy density and the microplastic entropy generated. When the cumulative microplastic entropy generated in cyclic loading exceeds the critical microplastic entropy threshold calculated from tensile tests, failure occurs. Calculated fatigue life with 99% tolerance limits (99% confidence) compares favorably to data for 6061-T6 aluminum rod and sheet specimens. Model parameters are determined from tensile tests and simple cyclic tests, decreasing the high cost of fatigue testing for parameter identification. This new theory has the potential to significantly decrease the cost of characterizing the fatigue properties of new materials.
Solving Huge Gyroscopic Eigenproblems With AMLS and Subspace Iteration
Authors: Voss Heinrich , Yin Jiacong , Chen Pu
Published: October 2013

The Automated Multilevel Sub-structuring (AMLS) method is a powerful technique for computing a large number of eigenpairs with moderate accuracy for huge definite eigenvalue problems in structural analysis. It also turned out to be a useful tool to construct a suitable ansatz space for orthogonal projection methods for gyroscopic problems. This paper takes advantage of information gained from AMLS to improve the obtained eigenpairs via a small number of subspace iteration steps.
Comparison Between PIV Results and CFD Simulations of Air Flows in a Thin Electronics Casing Model
Authors: Ishizuka Masaru , Hatakeyama Tomoyuki , Kibushi Risako , Nishino Yasushi , Nakagawa Shinji
Published: October 2013

The aim of this study was to acquire benchmark test data for simulating computational fluid dynamics in thin electronic equipment. Flow in the model of thin electronic equipment was measured by using particle image velocimetry PIV). Dummy components were placed in the model and their configurations altered. The temperature rise of a heat source in the model was also measured and the cooling performance examined. The PIV measurement results revealed the changes in flow with changes in the configuration of the components. Comparison of the experimental results with numerical results showed good agreement in terms of the overall velocity field.
Preserving Passenger Comfort Through RWI Analysis
Authors: Colino Mark P. , Rosenstein Elena B.
Published: October 2013

The air conditioning systems designed for passenger rail cars typically exchange heat with the outside air environment; when the trains operate within tunnels, the effectiveness of the air conditioning systems may diminish if the tunnel is too warm. Therefore, one of the traditional activation modes associated with rail tunnel ventilation systems is summertime cooling — for the purpose of maintaining onboard passenger comfort. However, summertime cooling modes can be problematic from the standpoints of fan operating pressure (i.e. an opposing air pressure is created whenever trains approach ventilation shafts), energy consumption and emergency preparedness (i.e. fans operating in the wrong direction when a fire is detected).

In this paper, the thermal comfort of rail transportation passengers was studied in detail using the Relative Warmth Index (RWI) analyses to determine if the combination of: warm outdoor weather, the tunnel heat-sink effect, the rail coach design air temperature and typical commuting scenarios necessitated running the tunnel fans in a summertime cooling mode to preserve passenger comfort. If the summertime cooling mode could be eliminated, or even minimized, the tunnel ventilation usage/operating costs would be reduced, the fans would have a longer service life and the system would have greater overall availability for emergency events.
Dilatational Spherical Wave Propagations of Multiple Energy Sources in Viscous Fluid-Saturated Elastic Porous Media
Authors: Han Lu , Dai Liming
Published: October 2013

Biot developed a representative model for the propagation of stress waves in a porous elastic solid containing a compressible viscous fluid, which is the fundamental theory about wave propagation in porous media. The solution proposed in that work has the same form under the model with or without fluid viscosity, though it is conflicted with the energy dissipation when the viscosity of flow is involved. In this study, the solution under the viscosity model has been modified with the exponential time dissipation term introduced to different forms under light and heavy viscosity, which complies with Biot’s oscillation form when there is no damping caused by fluid viscosity, and makes more sense as less oscillatory when the viscosity becomes large, as the energy will be dissipated in that case.
Energy Modelling of Modern Residence in Egypt
Authors: Khalil Dalia E. , Medhat Ahmed A. , Khalil Essam E.
Published: October 2013

The present paper aims to develop/investigate an innovative approach for affordable houses for the medium income families, forming the major category of the Egyptian society using Design-Builder simulation and emphasizing the mechanical HVAC systems and their impact on energy consumption. Design-Builder ( a simulation user-friendly interface) for Energy-Plus (an energy simulation engine for energy modeling in buildings, heating, cooling, lighting, ventilating and other energy flows) is utilized to create a “virtual environment” in which the HVAC system effect is studied. Extensive field surveys are made to collect data regarding occupancy behavior, light and equipment schedules and other mechanical systems usage in such application. The majority of surveys indicated that split system (heat pumps) + mechanical ventilation (exhaust fan for bathroom and kitchen) are most common in the Egyptian society. The subject facility is located in Cairo, Egypt. The layout of this building/house has been developed by research architects in the Housing & Building National Research Centre HRBC taking into their consideration the medium income citizens, [1] needs and limited budget, the energy efficiency concepts as well as the previous work carried in the field of sustainable architecture. The individual buildings are formed of three floors containing twelve 100 m2 apartments. Each apartment consists of three bedrooms, a bathroom, a kitchen and a lounge.
The Response of Composite Plates to Underwater Blast
Authors: Schiffer Andreas , Tagarielli Vito L. , Cocks Alan C. F. , Petrinic Nik
Published: October 2013

Laboratory-scale fluid-structure interaction (FSI) experiments are performed in order to examine the response of submerged, clamped composite plates to dynamic loading by underwater shock waves. Experiments are conducted in a recently developed transparent shock tube [1] and allow measurements of deflection history and cavitation processes. Analytical models are implemented for the underwater blast response of orthotropic composite plates and analytical predictions are compared to those of explicit finite element (FE) simulations and to experimental evidence.
Numerical Modelling of the Dip Coating Problem
Authors: Abdelkader Filali , Khezzar Lyes , Mitsoulis Evan
Published: October 2013

Flow behavior of Newtonian and Bingham fluids flow in a dip coating process was numerically analyzed using finite element and finite volume techniques. To capture the free surface location, two techniques have been considered; the remeshing technique embedded in the finite element code Polyflow and the Volume of Fluid model incorporated in the finite volume code FLUENT. In contrast to the first technique, the later does not require a prior approximate knowledge of the final free surface shape and requires less resource. A fairly good agreement is observed for both techniques with numerical results available in the literature for both Newtonian and Bingham fluid cases.
Modeling and Simulation of Dielectrophoretic Particle Assembly
Authors: Hossan Mohammad Robiul , Dutta Prashanta
Published: October 2013

In this paper, we present a comprehensive study of dielectrophoretic particle assembly using hybrid immersed interface-immersed boundary method where both dielectrophoretic and hydrodynamic forces are evaluated with interface resolved approach instead of point-particle method. Immersed interface method is employed to capture physics of electrostatics in a fluid media with embedded particles, while immersed boundary method is used to study hydrodynamics with rigid and/or flexible immersed boundaries. Unlike existing studies, dielectrophoretic force is obtained using Maxwell’s stress tensor; a comparative study between Maxwell stress tensor and effective dipole moment methods are presented. This hybrid method is employed to demonstrate the dielectrophoretic particle assembly for both similar and dissimilar particles. In a fluid media, the similar particles form a chain parallel to the applied electric field, while the dissimilar particles form a chain perpendicular to the applied electric field. These results are consistent with the recent experimental observations.
Microwave Heating of Multi-Layered Composites for Bonding
Authors: Mani Kasi B. , Hossan Mohammad R. , Dutta Prashanta
Published: October 2013

A detailed theoretical analysis has been carried out to study selective heating of multilayered dielectric composite under microwave heating by solving an unsteady energy equation with an electric field and frequency dependent heat source term. The source term is computed from simplified Maxwell’s equations under plane wave assumption. Analytical solution obtained from this study is used to understand the effect of layer thickness on temperature distribution in a thin layer of poly-aniline sandwiched between two polymer (PMMA) substrates. It is found that dielectric properties, sample thickness and processing time have significant influence on the microwave heating pattern. The highly dielectric poly-aniline absorbed more microwave power than that of PMMA and attained temperature above the melting point of PMMA in less than 2 minutes. These results show that localized melting of PMMA can be achieved using household microwave. This analytical investigation on multi-layered composites will provide a significant insight to understand and overcome the challenges of selective heating and localized bonding technique.
GPU-Based Simulations to Analyze the Effect of Heat Source in Mixed Convection
Authors: Qazi Nabeel A. , Akhtar Imran , Khalid M. Saif Ullah
Published: October 2013

Thermo-fluids applications are studied, both experimentally and numerically, due to its applications in various engineering and scientific problems. With the growing computer technology, numerical simulations are often employed to analyze thermofluid phenomenon. In this paper, we study the effect of heat source and sink in mixed convection in a lid-driven square cavity. Many applications require efficient computation of flow and temperature field data for cooling and other control purposes. We develop an explicit numerical methodology, both on CPU and GPU platforms, to solve the governing equations. The numerical scheme is implemented sequentially on a CPU and in parallel on a GPU using CUDA programming language. We vary the size and locations of the heated wall, along with the inclination of cavity, to study its effect on convection. In terms of parallel performance, GPU provides speed-up ranging from 3 to 13 depending on the problem configuration.
Subharmonic Orbits of Rectangular Thin Plate With Parametrically and Externally Excitations
Authors: Zhang Wei , Sun Min , Wang Qian , Chen Jianen
Published: October 2013

In this paper, the bifurcations of subharmonic orbits for a four-dimensional rectangular thin plate with parametrically and externally excitations is considered for the first time. The formulas of the rectangular thin plate are derived by using the von Karman-type equation, the Reddy’s third-order shear deformation plate theory and the Galerkin’s approach. The unperturbed system is composed of two independent planar Hamiltonian systems such that the unperturbed system has a family of periodic orbits. The problem addressed here is the determination of sufficient conditions for some of the periodic orbits to generate subharmonic orbits after periodic perturbations. Thus, based on periodic transformations and Poincaré map the subharmonic Melnikov method is improved to enable us to analyze directly the non-autonomous nonlinear dynamical system, which is applied to the non-autonomous governing equations of motion for the parametrically and externally excited rectangular thin plate. The results obtained here indicate that subharmonic motions can occur in the rectangular thin plate. The method succeeds in establishing the existence of subharmonics in perturbed Hamiltonian systems as well as in discussing their bifurcations. Numerical simulation is also employed to find the subharmonic motions of the parametrically and externally excited rectangular thin plate.
Integration Between Gas Turbines and Concentrated Parabolic Trough Solar Power Plants
Authors: Cipollone Roberto , Cinocca Andrea
Published: October 2013

Parabolic Trough Concentrating Solar Power plants (PT-CSP) technology has the capability to give, in the mean future, a strong contribution to the electrical energy generation. In the long term, inside a new framework of relationships concerning energy production, many aspects would justify a significant contribution to the phase out of fossil sources use.

The paper concerns about a theoretical modeling aimed at improving the performances of CSP which approaches the energy generation from a system point of view. Thanks to it, the attention is focused on the use of gases as heat transfer fluid inside the solar receivers and on the possibility to use it as working fluid inside unconventional gas turbines for a direct electricity generation.

The success of this concept is related to the possibility to increase the fluid temperature above the actual maximum values: this requires that the receiver efficiency has to be recalculated as a function of the fluid temperature.

An innovative integration between the solar field and the gas turbine power plant, modified in order to maximize thermal energy conversion, is discussed.
Experimental Investigation of Double Rows Film Cooling on Vane Pressure Side
Authors: Elnady T. , Hassan I. , Kadem L. , Lucas T.
Published: October 2013

An experimental investigation has been performed to study the effect of hole shape and position on the cooling performance of a gas turbine stator. Two rows of laid-back fan-shaped holes are placed on the pressure side of a scaled vane in a two-dimensional cascade and compared with two identical rows of standard cylindrical exit. Both hole shapes have the same base diameter and were investigated at three different blowing ratios (1, 1.35, and 1.7) with the same coolant flow rate used in each case. The experiments are conducted for the first row of holes only, then for the second row only, and finally for both two rows together at a 0.9 density ratio. The mainstream inlet Reynolds number based on the true chord is 1.4E5 and the exit Mach number is 0.23. The local distributions of the heat transfer coefficient and film cooling effectiveness are obtained using a transient TLC technique. The second row of holes, with by a higher local radius of curvature, shows a 40% decrease in the cooling effectiveness as well as a 10% increase in the heat transfer coefficient near downstream of the hole compared with that obtained by the first hole. The double injection provides a slight increase in the cooling effectiveness and a lower heat transfer coefficient due to the favorable interaction between both injections.
Holographic Microwave Imaging Array for Early Breast Cancer Detection
Authors: Wang Lulu , Simpkin Ray , Al-Jumaily A. M.
Published: October 2013

This paper presents a new Holographic Microwave Imaging Array (HMIA) technique for early breast cancer detection, which is based on microwave holography and aperture synthesis imaging techniques. Using published data for the dielectric properties of normal breast tissues and malignant tumours, a two-dimensional (2D) mathematical model was developed under the MATLAB environment to demonstrate the proposed imaging technique. The computer simulations showed that tumours as small as 2 mm in diameter anywhere within the breast could be successfully detected. The significant imaging improvement was achieved by optimizing antenna array configurations to offer the best possibility of detecting tumours of various size, shape and position.
MHD Free Convection Flow Past an Impulsively Started Infinite Vertical Plate With Thermal Stratification and Radiation
Authors: Deka Rudra Kt. , Neog Bhaben Ch.
Published: October 2013

An exact solution to the one-dimensional unsteady natural convection flow past an impulsively started infinite vertical plate with combined effect of thermal stratification and radiation under the influence of transverse magnetic field is presented. The solutions for fluid velocity, temperature are obtained by the Laplace transformation technique. Comparison is made between the solutions with and without thermal stratification and the differences in both the cases are presented graphically. Comparison reveals that thermal stratification has significant impact on convection flow past vertical plates on radiating MHD flows.
Experimental Investigation of Flame Extinction Limits of Propane and Jet A Fuel
Authors: Grisanti Maria A. , Parthasarathy Ramkumar N. , Gollahalli Subramanyam R.
Published: October 2013

Flame extinction experiments were conducted using propane (with and without additives) and Jet A (in partially premixed and diffusion flame modes). A single-flame counter-flow burner configuration was used to measure the extinction limits. The set-up consisted of two contoured nozzles (exit diameter of 6.4 mm), designed to produce top-hat velocity profiles at the exit with a separation distance of 12.7 mm between them. A cooling system, which consisted of a submersible water pump, water reservoir and a split aluminum cooling jacket, was used to cool the top burner and avoid heating of the top burner by the hot buoyant flame products. A nitrogen shield was used to protect the flame from air entrainment and perturbations from the surroundings. A heating system was used to vaporize the liquid Jet A fuel in air or nitrogen maintained at a temperature up to 325 °C. For premixed propane flames, as the stretch rate increased from 364 s−1 to 462 s−1, the volumetric percentage of propane varied from 2.23% to 2.83% at lean extinction. These results, when modified suitably to take into account that only air was fed from the top burner, agreed well with previous results obtained from twin-flame configurations. For a given stretch rate, the propane flame extinguished at a richer condition when nitrogen or carbon dioxide was added to the air stream. Also, carbon dioxide was more effective in extinguishing the flat flame than nitrogen. The flame extinction limits were measured for Jet A for stretch rates varying between 218.7 s−1 and 412.9 s−1. It was found that the Jet A flames in diffusion mode were more resistant to extinction than those in the premixed mode.
On Dynamics of Spinning Structures
Authors: Gupta K. K. , Ibrahim A.
Published: October 2013

This paper provides details of developments pertaining to vibration analysis of gyroscopic systems, that involves a finite element structural discretization followed by the solution of the resulting matrix eigenvalue problem by a progressive, accelerated simultaneous iteration technique. Thus Coriolis, centrifugal and geometrical stiffness matrices are derived for shell and line elements, followed by the eigensolution details as well as solution of representative problems that demonstrates the efficacy of the currently developed numerical procedures and tools.
Nonlinear Vibration of a Thin-Plate Workpiece During High Speed Milling Under 1:1 Internal Resonance Condition
Authors: Zhang Wei , Zhou Rui , Zu Jean W. , Wang Qian
Published: October 2013

In this paper, the nonlinear vibration of a thin-plate workpiece during milling process is investigated. The thin-plate workpiece is modeling as a cantilevered thin plate. The equations of motion for the thin-plate workpiece are derived based on the Kirchhoff-plate theory and the von Karman strain-displacement relations by using the Hamilton’s principle. By applying the Galerkin’s approach, the resulting equations are reduced to a two-degree-of-freedom nonlinear system with external excitations. Considering the case of 1:1 internal resonance, the method of Asymptotic Perturbation method is utilized to obtain the averaged equations of the cantilevered thin-plate workpiece. Numerical method is used to study nonlinear dynamics of the cantilevered thin plate and get the two-dimensional phase portraits, waveforms phase, three-dimensional phase and frequency spectrum phase. The result shows that the cantilevered thin-plate workpiece exhibits the complex dynamic behavior with the increase of the amplitude of the forcing excitation.