bluuebunny/crossref_metadata_2025 huggingface dataset:
Engineering Design and Education: A Case Study on Designing a Competition Fuel Efficient Vehicle Through Experiential Learning
Authors: Lu Wen Feng , Lim Hong Wee , Goh Kim Hoo
Published: June 2012

Engineering design involves a series of steps that lead to the creation of a product, a system, or a service to meet desired needs. The design and creation of innovative solutions to challenging engineering design problems require young engineers to be immersed in an education environment which challenges and nurtures the thought process and provides the necessary hands-on experience in design. There is increasing convergence in opinions that problem-based and experiential learning should be more integrated with the science-based engineering programs. Experiential learning is the key to engaging students to learn effectively. This paper describes an experiential learning experience for a group of undergraduate students in National University of Singapore (NUS) to design a competition fuel efficient vehicle. The students started with engineering design process and went through a series of steps to design, manufacture, assemble, test and compete in a specifically built prototype urban concept car for the competition with the experiential learning experience. Components of the competition vehicle, from chassis to diminutive parts, such as wheel uprights and motor mounts, have been carefully designed, properly analyzed and fabricated in a teamwork environment. The result is a futuristic fuel efficient urban concept car that won many awards in the competition. The team also took the initiative to promote eco-friendliness and raise awareness with the design of fuel efficient car to battle environmental issues like climate change, pollution, and energy crisis.
Early Design Stage Reliability Analysis Using Function-Flow Failure Rates
Authors: O’Halloran Bryan M. , Stone Robert B. , Tumer Irem Y.
Published: June 2012

In this paper, failure rates for function-flow pairs are presented. This data creates an opportunity for the designer to move reliability analysis earlier in the design process. The function-flow failure rates can be used to make design decisions before components are selected giving the designer increased knowledge to explore alternative options. A reliability block diagram approach has been adopted to evaluate the reliability of three designs at both the functional and component level. The results show that the bounds from the functional reliability overlap those of the component reliability.
Configuration of a Novel Sub-Millimeter Resolution Piezoelectric Actuator Based Wearable Tactile Display System for Blind Individuals
Authors: Naidu Prakash C. R. J. , Yechangunja Ramesh , Srinivasan Mandayam A.
Published: June 2012

This paper presents the work conducted towards the realization of a novel tactile display system, first using block type piezoelectric actuators and later using cantilever type piezoelectric actuators. The system is particularly useful for blind users to communicate with computers through touch, but also has many potential applications in several other fields such as virtual reality, gaming, and other general communication interfaces for sighted users. Although piezoelectric actuators have been used in the past in electronic Braille and other systems, there is no reported configuration that can achieve sub-millimeter center-to-center resolution in an array of programmable actuation pins that act as interfaces in contact with a human body part such as a finger. This paper reports development of a wearable tactile display device: (a) built of block type actuators and its characterization showing that the perception was not adequate for certain purposes; (b) further, a novel arrangement with considerable improvement in perception wherein- (i) two or more vibrating stimulation pins can be located close to each other at the plane of contact with a finger, and (ii) actuated by means of piezoelectric bending elements arranged in a cantilever configuration partially overlapping each other in multiple planes. A significant feature of the unique configuration reported in this paper is that vibratory stimulation can be achieved at finer spatial resolutions than hitherto achieved.
A New Fractional Order Observer Design for Fractional Order Nonlinear Systems
Authors: Dadras Sara , Momeni Hamid Reza
Published: June 2012

In this paper, a class of fractional order systems is considered and simple fractional order observers have been proposed to estimate the system’s state variables. By introducing a fractional calculus into the observer design, the developed fractional order observers guarantee the estimated states reach the original system states. Using the fractional order Lyapunov approach, the stability (zero convergence) of the error system is investigated. Finally, the simulation results demonstrate validity and effectiveness of the proposed scheme.
Sustainable Manufacturing Analysis Using Activity Based Costing in SysML
Authors: Romaniw Yuriy , Bras Bert , Guldberg Tina
Published: June 2012

This paper outlines an approach for dynamic, multi-scale modeling of manufacturing systems using an Activity Based Cost structure. The purpose of these models is to assess the sustainability of the manufacturing system and aid as a quick, first principle analysis tool for comparing alternatives. The models are constructed using a computer-aided version of the object oriented modeling language SysML. The model, known as the Activity Based Object Oriented Manufacturing Model (or ABOOM Model), is capable of decomposing a system from multiple perspectives, using the same library of activities reducing redundancy and complexity while increasing modularity. The model is built in MagicDraw SysML, using ParaMagic and Mathematica to parse and simulate the model and return numerical results. This paper builds on a project previously presented in its infancy at IDETC/CIE 2009. This paper presents a functional model structure now that the project has matured and nears the next phase of implementation. Executable hypothetical case study instance structures are presented as well as results from a validation experiment performed since the project was first presented. This paper summarizes the results from the case studies as well as the conclusions from the validation experiment.
Online Material Characterization Using Full-Field Strain Measurement
Authors: Furukawa Tomonari , Pan Jan Wei , Michopoulos John G. , Iliopoulos Athanasios
Published: June 2012

This paper presents and reviews an online methodology which characterizes materials using full-field strain measurement. The proposed methodology utilizes the principle of conservation of energy and formulates both the deterministic technique based on the pseudoinverse analysis and the stochastic technique based on the Kalman filter in terms of recursive linear equations. The methodology further describes the derivation the average Frobenius norm and the differential entropy as recursively computable measures enabling the evaluation of the well-posedness of the material characterization problem as well as the uncertainty of the identified constants. Comparative studies have identified that the deterministic identification is a particular case of the stochastic identification, whilst the adequacy and significance of both the average Frobenius norm and the differential entropy was reconfirmed.
Operational Space Impulse Momentum Algorithm for Flexible Multibody Systems With Generalized Topologies
Authors: Mukherjee Rudranarayan M.
Published: June 2012

This paper presents a new methodology for modeling discontinuous dynamics of flexible and rigid multibody systems based on the impulse momentum formulation. The new methodology is based on the seminal idea of the divide and conquer scheme for modeling the forward dynamics of rigid multibody systems. While a similar impulse momentum approach has been demonstrated for multibody systems in tree topologies, this paper presents the generalization of the approach to systems in generalized topologies including many coupled kinematically closed loops. The approach utilizes a hierarchic assembly-disassembly process by traversing the system topology in a binary tree map to solve for the jumps in the system generalized speeds and the constraint impulsive loads in linear and logarithmic cost in serial and parallel implementations, respectively. The coupling between the unilateral and bilateral constraints is handled efficiently through the use of kinematic joint definitions. The generalized impulse momenta equations of flexible bodies are derived using a projection method.
Effects of Bearing Radial Internal Clearance on Dynamic Behavior and Bifurcations in Planetary Gears
Authors: Guo Yi , Parker Robert G.
Published: June 2012

This study investigates the dynamics of planetary gears where nonlinearity is induced by bearing clearance. Lumped-parameter and finite element models of planetary gears with bearing clearance, tooth separation, and gear mesh stiffness variation are developed. The harmonic balance method with arc-length continuation is used to obtain the dynamic response of the lumped-parameter model. Solution stability is analyzed using Floquet theory. Rich nonlinear behavior is exhibited in the dynamic response, consisting of nonlinear jumps and a hardening effect induced by the transition from no bearing contact to contact. The bearings of the central members (sun, ring, and carrier) impact against the bearing races near resonance, which leads to coexisting solutions in wide speed ranges, grazing bifurcation, and chaos. Secondary Hopf bifurcation is the route to chaos. Input torque can significantly suppress the nonlinear effects caused by bearing clearance.
Nonlinear Dynamics of Piecewise Smooth Systems and Damage Identification
Authors: Vestroni Fabrizio , Casini Paolo , Giannini Oliviero
Published: June 2012

This paper addresses the study of the nonlinear dynamics of non-smooth systems representative of beams with breathing cracks. The aim is to use the nonlinear characteristics of the system response to identify the damage in cracked structures that behave similarly to bilinear systems and hence exhibit nonlinear phenomena in the dynamic response even for low damage levels. The idea is supported by the study of a piecewise smooth 2-DOF model where a wide variety of nonlinear phenomena has been evidenced, which include among others the bifurcations of super-abundant modes and a number of resonances greater than the system degrees of freedom. All these phenomena are strongly dependent on the stiffness discontinuity which is governed by the damage parameter. A novel method able to detect crack severity and position through measurements of the system nonlinear response has been developed and a cantilever beam with a breathing crack is considered as a numerical test case. The inverse procedure is tested by identifying the position and depth of a crack using pseudo-experimental data; the results show a strong robustness of the method even in the case when the data are affected by measurement errors.
Coalition Formation for Unmanned Quadrotors
Authors: Mancini A. , Benini A. , Frontoni E. , Zingaretti P. , Longhi S.
Published: June 2012

Today Unmanned Aerial Vehicles (UAVs) and in particular quad-rotors represent novel platforms to accomplish a wide set of missions as surveillance, Search & Rescue, inspection, photogrammetry. The main limitation of these vehicles is represented by the restricted operating area. The area is mainly limited by power supplies (batteries or fuel). A strategy to overcame this limitation is to increase the number of vehicles forming a coalition. The main benefit of coalition formation are the extended mission range and the capability to increase the sensorial set. Each vehicles is a part of a dynamic network that must be properly coordinated in order to optimize all the available resources. In this paper a new framework for simulation of unmanned vehicles in cooperative scenarios is first presented. The framework is based on the interaction of a physics-engine, which simulates the dynamics of vehicles and their interaction with world increasing the realism of simulation, and a simulation environment where the high-level strategy is designed/developed. A Model Predictive Control (MPC) is then introduced to solve the problem of leader-follower applied to quad-rotors. Using the developed framework and the MPC technique is possible to easily instantiate the coalition minimizing also a cost function. The obtained results from the control strategy point of view show that positioning error at steady state is equal to zero. The MPC allows also the modelling of different conflicting constraints as the control actions, positioning error, and fuel/energy consumption.
A Joint-Coding Scheme With Crosstalk Avoidance
Authors: Zhou Lei , Wu Ning , Ge Fen
Published: June 2012

The reliable transfer in Network on Chip can be guaranteed by crosstalk avoidance and error detection code. In this paper, we propose a joint coding scheme combined with crosstalk avoidance coding with error control coding. The Fibonacci numeral system is applied to satisfy the requirement of crosstalk avoidance coding, and the error detection is achieved by adding parity bits. We also implement the codec in register transfer level. Furthermore, the schemes of codec applying to fault-tolerant router are analyzed. The experimental result shows that “once encode, multiple decode” scheme outperforms other schemes in trade-off of delay, area and power.
Affect Prediction for Emotional Design: A Comparison Study of Physiological and Subjective Self-Report Data
Authors: Zhou Feng , Qu Xingda , Jiao Jianxin Roger , Helander Martin G.
Published: June 2012

Emotional design has attracted much attention due to its important role in the development of products and services towards high value-added user satisfaction and performance enhancement. However, how to predict users’ affective states in real time and without having to interrupt the user is critical to emotional design. This study compared affect prediction between using physiological measures and using self-report subjective measures. Specifically, an experiment was designed to elicit seven different affective states using standardized affective pictures as visual stimuli. Each stimulus was presented for 6 seconds and multiple physiological signals were measured, including facial electromyography, respiration rate, electroencephalography, and skin conductance response. Subjective ratings were also recorded immediately after stimulus presentation. Three data mining methods (i.e., decision rules, k-NN, and decomposition tree) based on the rough set theory were applied to construct prediction models from physiological measures and subjective measures, respectively. We obtained the highest mean prediction rate at 73.69% for physiological models and 52.43% for subjective models, respectively, across the 7 affective states. It demonstrates that physiological data are able to predict better result than subjective self-report data did and that physiological computing offers great potential for the development of emotional design.
Prospect of Design for Mass Customization and Personalization
Authors: Jiao Roger J.
Published: June 2012

The prevailing practice of design for mass customization manifests itself through a configure-to-order paradigm, which means to satisfy explicit customer needs and built upon legacy design. With pervasive connectivity and interactivity of the Internet and sensor networks, personalization has been witnessed in a number of industry sectors as a promising strategy that makes the market of one a reality. This positioning paper envisions an extension to design for mass customization and personalization (DFMCP). By exploiting implicit market demand information and revealing latent customer needs, DFMCP aspires to assist customers in making better informed decisions, and to the largest extent, to anticipate customer satisfaction and adapt to customer delight. Based on a multiverse of user experience, product differentiation and co-creation, the key issues of DFMCP are discussed.
Case Study of Chinese SMEs Oriented Environmental Impact Assessment on Refrigerator Production
Authors: Yu Suiran , Tao Jing , Yang Qingyan , Zhang Jianpu , Yin Fengfu
Published: June 2012

This paper presents a Life Cycle Assessment (LCA) case study aiming at assisting Chinese Small and Medium Enterprises (SMEs) to identify the environmental improvement opportunities. A typical refrigerator SME located in suburb of Shanghai is visited for data collection. Besides, related project reports, academic papers, and LCA software and databases are referred for necessary data. Environment inventory of manufacturing a typical Chinese household refrigerator model is calculated and analyzed. Results show that ABS components are the major contributors to energy consumption; production of rubber (for gaskets), MDI (for insulation) and packaging materials are the most water polluting processes, while phosphatizing treatment of compartment plates and door panels generates most of the waste water with phenol; the majority of CO2 (eq.) and SO2 (eq.) is emitted during ABS component and steel sheet production while the use of F-containing coolant causes most of the CFC-11(eq.) emission, which is the major cause of ozone depletion. The opportunities of environmental improvements are then assessed by sensitivity and economical analysis. It is suggested that for refrigerator manufacturing SMEs, reduction in ABS use and eco-optimized packaging solutions are the most cost-effective measures for environmental improvements. Also, there are improvement potentials in material and energy utility management of SMEs. However, considering their limited management capability and access to resources and information, SMEs needs support from the public sector in entrepreneurship and environmental education, technological and financial help and regulatory protection for sustainable development.
Correlation Between Impulse and Compliance Based Methods in Rigid Body Collisions
Authors: Gharib Mohamed , Hurmuzlu Yidirim
Published: June 2012

Impact problems arise in many practical applications. The need of obtaining an accurate model for the inelastic impact is a challenging problem. In general, two approaches are common in solving the impact problems: the impulse-momentum and the compliance based methods. The former approach included the coefficient of restitution which provides a mechanism to solve the problem explicitly. While the compliance methods are generally tailored to solve elastic problems, researchers in the field have proposed several mechanisms to include inelastic losses. In this paper, we present a correlation between the coefficient of restitution in the impulse-momentum based method and the contact stiffness in the compliance methods. We conducted numerical analysis to show that the resulting solutions are indeed identical for a wide range of impact conditions. The numerical results showed that, the two methods can produce similar outcomes if they satisfied a set of end conditions.
Topology Optimization of Spacers for Maximizing Permeate Flux on Membrane Surface in Reverse Osmosis Channel
Authors: Oh Seungjae , Wang Semyung , Park Minkyu , Kim Joonha
Published: June 2012

The objective of this study is to design spacers using fluid topology optimization in 2D crossflow Reverse Osmosis (RO) membrane channel to improve the performance of RO processes. This study is an initial attempt to apply topology optimization to designing spacers in RO membrane channel. The performance was evaluated by the quantity of permeate flux penetrating both upper and lower membrane surfaces. A coupled Navier-Stokes and Convection-Diffusion model was employed to calculate the permeate flux. To get reliable solutions, stabilization methods were employed with standard finite element method. The nine reference models which consist of the combination of circle, rectangular, triangle shape and zigzag, cavity, submerge configuration of spacers were simulated. Such models were compared with new model designed by topology optimization. The permeate flux at both membrane surfaces was determined as an objective function. In addition, permissible pressure drop along the channel and spacer volume were used as constraints. As a result of topology optimization as the permissible pressure drop changes in channel, characteristics of spacer design development was founded. Spacer design based on topology optimization was reconstructed to a simple one considering manufactuability and characteristics of development spacer design. When a simplified design was compared with previous 9 models, new design has a better performance in terms of permeate flux and wall concentration at membrane surface.
Transmission System Improvements in Actuating a Desktop Haptic Strip for Exploration of Virtual Objects
Authors: Covarrubias Mario , Bordegoni Monica , Cugini Umberto , Antolini Michele
Published: June 2012

This paper describes the servo actuated transmission system required to drive a desktop haptic strip interface. The haptic strip is a mechatronic device which is used for exploration of virtual surfaces with aesthetic value. The simulation of tasks, such as the exploration of aesthetic real surfaces made by industrial designers in order to check the quality of prototypes, require full hand contact with the shape on a one-to-one scaled representation of the object. Our mechatronic device allows a continuous, free hand contact on a developable real plastic tape actuated by a servo-controlled mechanism in which is used the tessellation approach. In fact, the triangular mesh simplifies the conformation of the developable real surface as the virtual one. This paper discusses the design concept, novel kinematics and mechanics, improvements of the transmission system and control for the Desktop Strip.
Wireless Charging of Electric Vehicles: A Review and Experiments
Authors: Ma Chengbin , Fu Minfan , Zhu Xinen
Published: June 2012

In this paper, the technologies for electric vehicle wireless charging are reviewed including the inductive coupling, magnetic resonance coupling and microwave. Among them, the magnetic resonance coupling is promising for vehicle charging mainly due to its high efficiency and relatively long transfer range. The design and configuration of the magnetic resonance coupling based wireless charging system are introduced. A basic experimental setup and a prototype electric vehicle wireless charging system are developed for experimental and research purposes. Especially the prototype system well demonstrates the idea of fast and frequent wireless charging of supercapacitor electric vehicles using magnetic resonance coupling. Though the idea of wireless energy transfer looks sophisticated, it is proved to be a handy technology from the work described in the paper. However, both component and system-level optimization are still very challenging. Intensive investigations and research are expected in this aspect.
Fractional Integration of Generalized Bessel Function of the First Kind
Authors: Malik Pradeep , Mondal Saiful R. , Swaminathan A.
Published: June 2012

Generalizing the classical Riemann-Liouville and Erde´yi-Kober fractional integral operators two integral transforms involving Gaussian hypergeometric functions in the kernel are considered. Formulas for composition of such integrals with generalized Bessel function of the first kind are obtained. Special cases involving trigonometric functions such as sine, cosine, hyperbolic sine and hyperbolic cosine are deduced. These results are established in terms of generalized Wright function and generalized hypergeometric functions.
A Methodology for Remote Debug, Test and Maintenance Based on IEEE 1588
Authors: Ro¨ssler Peter , Ho¨ller Roland , Zauner Martin
Published: June 2012

This work describes a new methodology for the purpose of remote testing, debugging and maintenance of networked electronic and mechatronic systems which makes use of the IEEE 1588 high-precision clock synchronization protocol. After the underlying concepts of IEEE 1588 are briefly sketched, the paper describes how functionalities like testing, debugging and maintenance can benefit from a network-wide notion of time as provided by the IEEE 1588 standard. An implementation of the IEEE 1588 protocol with support for test, debug and maintenance as well as links to the integration of the proposed concept into existing tools are presented. Further, the proposed approach is discussed under consideration of recent standardization efforts. Finally, a case study from the area of automotive electronics is described.
An Exploratory Study to Fill the Gap Between Co-Design Tools and Industrial Applications
Authors: Peruzzini Margherita , Mengoni Maura , Germani Michele
Published: June 2012

This paper deals with the application of remote collaborative environments in product design, in particular for design review activities. In this context, companies actually face some troubles: limited knowledge about available tools, difficulty in coming to know and using innovative systems, and complexity in evaluating the impact of the technology on design collaboration. The present research suggests a novel collaborative environment (the CoReD platform) that merges system simplicity, project-oriented approach and customizable functions. It defines a metric-based protocol considering both performances and cognitive aspects to assess collaboration quality and then monitors design review sessions within three industrial Consortia. Research contributions are to answer two main questions: how to arrange a low-cost co-design environment and how to effectively evaluate the human-system interaction and collaborative performance in industrial use. Experimental results highlight that the CoReD platform is able to efficiently improve collaborative processes by affecting both product-process performance and human-based collaboration, mainly thanks to: system architecture simplicity, low cost, high customizable functionalities and ease of use for remote design. However, results demonstrate also that significant advantages can be achieved only if industrial partners have a good level of technical expertise and high motivation to collaborate each other.
Mechanical Sensing for Reformer Internal Diameter Data Capturing
Authors: Tang Liqiong , Fukuoka Morio , Tait Peter
Published: June 2012

Reformer tubes are commonly used in process industry. They are high cost components. The service life of reformer tubes is primarily determined by creep damage. To successfully manage the reformer tubes requires balancing creep life against the production gains of higher temperatures. The key to this requires an ongoing knowledge of the condition of the tubes. Monitoring the diametrical change of the tubes caused by creep damage is one of the most popular methods used in industry. However, the available reformer tube diametrical checking systems are very expensive. This paper presents a novel mechanical sensing unit for reformer tube diametrical measuring. The system is low cost and meets the industrial company specified requirements. Test and field trials made on the prototype gave a very encouraging result. With further study, it is expected that a robust and cost effective reformer tube diametric measuring system can be developed.
Path Tracking of a Fixed-Wing Autonomous Aerial Vehicle by High Order Sliding Mode Control
Authors: Castan˜eda Cuevas Herman , de Leo´n Morales Jesu´s , Olgui´n-Di´az Ernesto
Published: June 2012

In this paper, a robust control algorithm, based on sliding modes techniques, designed for trajectory tracking is applied to a fixed-wing small Autonomous Aerial Vehicle (AAV). Based on a mathematical modeling, parameters identification, and aerodynamics of both the AAV fuselage and its mobile surfaces a full dynamical model is obtained, where the control is proven. However, for control design, simplified versions of the motion models are studied resulting in simplified independent controller for the roll, pitch and yaw trajectories. Due to the nature of such controller, time derivative of control variables are needed but not available. Numerical differentiators also based on sliding modes are used in order to estimate those derivatives. Simulation results are given to illustrate the performance of the proposed tracking controller under parametric and unmodeled dynamics.
Microcontroller-Based Reformer Tube Internal Diameter Data Acquisition
Authors: Tang Liqiong , Fukuoka Morio , Tait Peter
Published: June 2012

Reformer tubes are high cost components in process industries. The service life of the reformer tubes is primarily ended by creep damage, which is caused by operation at high pressure and temperature. As a result of the creep damage, the geometry of reformer tubes changes especially the diameter. Therefore, monitoring the diametric changes of the reformer tubes is able to help to judge the degree of creep —damage. Different sensors, methodologies and techniques are proposed to obtain and monitor the diametric data of the reformer tubes. However, the cost of the dominant systems available is hard for majority of the industrial companies to afford. This paper presents a novel design of a microcontroller-based, wireless data acquisition system for obtaining reformer tube internal diameter data. The system focused on using cost effective components and methodologies. Tests made on the prototype showed that the system is able to reliably transmit reformer tube internal diametric data to a computer located on top of the reformer tube in real time.
Optimal Choice of Intra-Platoon Spacing Based on μ-Jump Maneuvers
Authors: Bassi L. , Braghin F. , Politi G. , Sbrosi M. , Zuin A.
Published: June 2012

Platooning deals with the automatic control of a line of road vehicles travelling with small spacing among each other. Thus, advantages in terms of higher road capacity and lower fuel consumptions can be achieved. One critical issue is the determination of the spacing between platoon vehicles. Usually emergency braking simulations with vehicles having different braking capabilities and roads characterized by different friction conditions are used to determine this spacing also considering effects of automatic control delays. In this paper a different and more critical condition is used to determine the target inter-vehicular spacing: emergency braking simulation on a road surface characterized by μ-jump conditions. Such maneuver, in which tire-road friction switches abruptly and repeatedly between high and low, is the typical maneuver adopted for assessing the performances of critical vehicle safety control logics such as ABS and ESP control algorithms.
Exome Sequencing Can Improve Diagnosis and Alter Patient Management
Authors: Dixon-Salazar Tracy J. , Silhavy Jennifer L. , Udpa Nitin , Schroth Jana , Bielas Stephanie , Schaffer Ashleigh E. , Olvera Jesus , Bafna Vineet , Zaki Maha S. , Abdel-Salam Ghada H. , Mansour Lobna A. , Selim Laila , Abdel-Hadi Sawsan , Marzouki Naima , Ben-Omran Tawfeg , Al-Saana Nouriya A. , Sonmez F. Müjgan , Celep Figen , Azam Matloob , Hill Kiley J. , Collazo Adrienne , Fenstermaker Ali G. , Novarino Gaia , Akizu Naiara , Garimella Kiran V. , Sougnez Carrie , Russ Carsten , Gabriel Stacey B. , Gleeson Joseph G.
Published: June 2012

Exome sequencing of 118 patients with neurodevelopmental disorders shows that this technique is useful for identifying new pathogenic mutations and for correcting diagnosis in ~10% of cases.
Myocardial Infarction Triggers Chronic Cardiac Autoimmunity in Type 1 Diabetes
Authors: Gottumukkala Raju V. S. R. K. , Lv HuiJuan , Cornivelli Lizbeth , Wagers Amy J. , Kwong Raymond Y. , Bronson Roderick , Stewart Garrick C. , Schulze P. Christian , Chutkow William , Wolpert Howard A. , Lee Richard T. , Lipes Myra A.
Published: June 2012

Acute myocardial infarction triggers an autoimmune attack on the heart in a mouse model of type 1 diabetes and in human type 1 diabetic patients.
Blocking an Immune Inhibitor: Small Step or Giant Leap?
Authors: Obhrai Jagdeep S.
Published: June 2012

Cancer patients with an array of ligand-positive tumors can be treated safely with an antibody that blocks an inhibitory immune receptor.
You Can Run, But You Can’t Hide
Authors: Oviedo-Orta Ernesto
Published: June 2012

A humanized model provides a new way to study the bone marrow niches where some malignant cells “hide” during chemotherapy.
Evaluation of the Andromas Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry System for Identification of Aerobically Growing Gram-Positive Bacilli
Authors: Farfour E. , Leto J. , Barritault M. , Barberis C. , Meyer J. , Dauphin B. , Le Guern A.-S. , Leflèche A. , Badell E. , Guiso N. , Leclercq A. , Le Monnier A. , Lecuit M. , Rodriguez-Nava V. , Bergeron E. , Raymond J. , Vimont S. , Bille E. , Carbonnelle E. , Guet-Revillet H. , Lécuyer H. , Beretti J.-L. , Vay C. , Berche P. , Ferroni A. , Nassif X. , Join-Lambert O.
Published: June 2012

Matrix-associated laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) is a rapid and simple microbial identification method. Previous reports using the Biotyper system suggested that this technique requires a preliminary extraction step to identify Gram-positive rods (GPRs), a technical issue that may limit the routine use of this technique to identify pathogenic GPRs in the clinical setting. We tested the accuracy of the MALDI-TOF MS Andromas strategy to identify a set of 659 GPR isolates representing 16 bacterial genera and 72 species by the direct colony method. This bacterial collection included 40
C. diphtheriae
, 13
C. pseudotuberculosis
, 19
C. ulcerans
, and 270 other
Corynebacterium
isolates, 32
L. monocytogenes
and 24 other
Listeria
isolates, 46
Nocardia
, 75
Actinomyces
, 18
Actinobaculum
, 11
Propionibacterium acnes
, 18
Propionibacterium avidum
, 30
Lactobacillus
, 21
Bacillus
, 2
Rhodococcus equi
, 2
Erysipelothrix rhusiopathiae
, and 38 other GPR isolates, all identified by reference techniques. Totals of 98.5% and 1.2% of non-
Listeria
GPR isolates were identified to the species or genus level, respectively. Except for
L. grayi
isolates that were identified to the species level, all other
Listeria
isolates were identified to the genus level because of highly similar spectra. These data demonstrate that rapid identification of pathogenic GPRs can be obtained without an extraction step by MALDI-TOF mass spectrometry.
Low sperm counts in genitourinary medicine clinic attendees: results from a case–control study
Authors: Carne Christopher A , Chilcott Sian , Palmer Christopher , Green Oliver , Bridge Simeon , Walsh Richard , Gramy-Mason Anna , O'Donovan Maria
Published: June 2012

Objectives

To conduct a case–control study of abnormalities in the semen of genitourinary (GU) medicine clinic attendees compared with general practice (GP) controls and in patients with asymptomatic and symptomatic non-specific urethritis (NSU) before and after the urethritis resolves.

Methods

Rates of semen abnormalities were compared between the different groups (19 with symptomatic and 27 with asymptomatic NSU, seven with symptomatic non-NSU and 64 clinic controls) and between clinic attendees and 417 patients attending GP for the first investigation of possible infertility. Those with symptomatic or asymptomatic NSU gave repeat semen samples on resolution of the NSU.

Results

The study included 117 clinic volunteers. They were shown to have statistically significantly worse total sperm counts (p=0.002), volume of semen (p<0.001) and percentage of abnormal forms (p<0.04) compared with 417 GP controls. Compared with the rest of the clinic volunteers, asymptomatic NSU patients had statistically significantly lower total sperm counts (p<0.02). Asymptomatic NSU patients had statistically significantly lower total sperm counts compared with symptomatic NSU patients (p<0.02). Compared with GP controls, clinic controls had statistically significantly inferior total sperm counts (p=0.009) and semen volume (p<0.001).

Conclusions

GU clinic attendees are more likely to have abnormalities of semen than patients attending GP for the first check for possible infertility. A high rate of abnormal semen findings are found in patients with and without NSU but the highest rate occurred in those with asymptomatic NSU. Is asymptomatic NSU therefore pathogenic and does it require treatment like symptomatic NSU?
Analytic energies and wave functions of the two-dimensional Schrödinger equation: ground state of two-dimensional quartic potential and classification of solutions
Authors: Tichý Vladimír , Kuběna Aleš Antonín , Skála Lubomír
Published: June 2012

New analytic solutions of the two-dimensional Schrödinger equation with a two-dimensional fourth-order polynomial (i.e., quartic) potential are derived and discussed. The solutions represent the ground state energies and the corresponding wave functions. In general, the obtained results cannot be reduced to two one-dimensional cases.
Cylindrical or spherical dust-ion acoustic soliton in an adiabatic dusty plasma with electrons following a q-nonextensive distribution
Authors: Eslami Parvin , Mottaghizadeh Marzieh , Pakzad Hamid Reza
Published: June 2012

Using the reductive perturbation technique, a cylindrical and (or) spherical Korteweg – de Vries (KdV) equation is derived for a dust-ion acoustic solitary wave (DIASW) in an unmagnetized dusty plasma, whose constituents are adiabatic ion ﬂuid, nonextensive electrons, and negatively charged static dust particles. The solution of the modiﬁed KdV equation in nonplanar geometry is numerically analyzed. The change of the DIASW structure due to the effect of the geometry, nonextensive parameter, dust density, and ion temperature is investigated by numerical calculation of the cylindrical and (or) spherical KdV equation. It is found that both compressive and rarefactive type DIA waves are obtained depending on the plasma parameter.
Half-metallic ferromagnetism in Wurtzite MS (M = Li, Na, and K)
Authors: Moradi M. , Rostami M. , Afshari M.
Published: June 2012

The magnetic properties of MS (M = Li, Na, K) compounds in a Wurtzite structure at zero pressure are investigated by using first principle calculations and the pseudopotential self-consistent method based on density functional theory. It is shown that MS compounds in Wurtzite structure are half-metallic ferromagnets with a magnetic moment of μB per formula unit and half-metallic gaps of 0.24, 0.52, and 0.62 eV for LiS, NaS, and KS, respectively. We also consider the effect of pressure on the half-metallicity of these compounds and we find that LiS, NaS, and KS in Wurtzite structure maintain their half-metallicity up to lattice compressions of 9%, 37%, and 60%, respectively, and as a result one can grow them over the semiconductors in Wurtzite structures that are produced experimentally. These properties cause Wurtzite MS compounds to be appropriate choices to create useful devices in spintronics.
Autoionization resonances in the argon iso-electronic sequence
Authors: George Juby , Pradhan G.B. , Rundhe Milind , Jose Jobin , Aravind G. , Deshmukh P.C.
Published: June 2012

We report results of theoretical studies of 3s → np and 2s → np autoionization resonances, respectively, in the 3p and the 2p photoionization cross sections of a few members (Ar, K+, Ca2+, Fe8+, Zn12+, and Kr18+) of the argon isoelectronic sequence, within the framework of the relativistic random phase approximation and using the relativistic multichannel quantum defect theory. The present approach would enable analysis of complex atomic spectra especially of atomic and (or) ionic species that are found in stellar gases in a computationally economical way. The shape profiles of the autoionization resonances have been analyzed in the present work using appropriate Fano parameters. The quantum defects determined for some of the lower or intermediate excited states are found to be in good agreement with the experimental and (or) theoretical results.
Transformation of Rice’s small perturbation solution for rough surface scattering into the high frequency reciprocal physical and geometric optics solutions
Authors: Bahar Ezekiel
Published: June 2012

A step by step transformation of the low frequency small height and slope perturbation solution into the high frequency reciprocal and dual, physical and geometrical optic solutions is presented. The familiar Kirchhoff approximations for the fields impressed by the incident plane wave upon the rough surfaces results in nonreciprocal solutions. It is shown that the surface element scattering coefficients based on the Kirchhoff approximations agree with the corresponding reciprocal physical optics solutions only at the stationary phase, specular points on the rough surfaces. While the Kirchhoff approximations and physical optics approximations are based on the characterization of the surface fields by Fresnel reflection coefficients, the corresponding surface element scatter coefficient derived for the small perturbation solution and the full wave solutions are based on the imposition of boundary conditions for the tangential components of the electric and magnetic fields. A flow graph schematically depicting the relationships between these solutions for the scattered fields is also presented.
Asymptotic behavior of eigenenergies of nonpolynomial oscillator potentials V(x) = x2N + (λx m1)/(1 + gx m2)
Authors: Nanayakkara Asiri
Published: June 2012

Analytic semiclassical energy expansions of nonpolynomial oscillator (NPO) potentials V(x) = x2N + (λx[Formula: see text])/(1 + gx[Formula: see text]) are obtained for arbitrary positive integers N, m1, and m2, and the real parameters λ and g using the asymptotic energy expansion (AEE) method. Because the AEE method has been previously developed only for polynomial potentials, the method is extended with new types of recurrence relations. It is then applied to the preceding general NPO to obtain expressions for quantum action variable J in terms of E and the parameters of the potential. These expansions are power series in energy and the coefficients of the series contain parameters λ and g explicitly. To avoid the singularities in the potential we only consider the cases where both λ and g are non-negative at the same time. Using the AEE expressions, it is shown that, for certain classes of NPOs, if potentials have the same N, and the same m1 – m2 or m1 – 2m2 then they have the same asymptotic eigenspectra. It was also shown that for certain cases, both λ and –λ as well as g and –g will produce the same asymptotic energy spectra. Analytic expressions are also derived for asymptotic level spacings of general NPOs in terms of λ and g.
VAN DER WAALS FRICTION: A HAMILTONIAN TEST-BED
Authors: BARTON GABRIEL
Published: June 2012

In the van der Waals regime (neglecting relativity and retardation), we find the power P generated by friction between two Drude-modelled dissipative half-spaces, at fixed separation and relative speed u, admitting only low u and low temperatures. This requires only elementary quantum mechanics; but the results can serve as partial checks on calculations in the fully retarded Casimir regime. They also raise questions regarding (i) the frequency-distribution of P; (ii) the status of predictions about Casimir forces generally, insofar as they feature parameters like conductivities with their empirical temperature-dependence; and (iii) calculations of heat transfer, insofar as they assume fluctuations in the two bodies to be uncorrelated.
VACUUM SUPERCONDUCTIVITY, CONVENTIONAL SUPERCONDUCTIVITY AND SCHWINGER PAIR PRODUCTION
Authors: CHERNODUB M. N.
Published: June 2012

In a background of a very strong magnetic field a quantum vacuum may turn into a new phase characterized by anisotropic electromagnetic superconductivity. The phase transition should take place at a critical magnetic field of the hadronic strength (Bc ≈ 1016 Tesla or eBc ≈ 0.6 GeV 2). The transition occurs due to an interplay between electromagnetic and strong interactions: virtual quark–antiquark pairs pop up from the vacuum and create — due to the presence of the intense magnetic field — electrically charged and electrically neutral spin-1 condensates with quantum numbers of ρ mesons. The ground state of the new phase is a complicated honeycomblike superposition of superconductor and superfluid vortex lattices surrounded by overlapping charged and neutral condensates. In this talk we discuss similarities and differences between the superconducting state of vacuum and conventional superconductivity, and between the magnetic-field-induced vacuum superconductivity and electric-field-induced Schwinger pair production.
THE HEISENBERG–EULER EFFECTIVE ACTION: 75 YEARS ON
Authors: DUNNE GERALD V.
Published: June 2012

On this 75th anniversary of the publication of the Heisenberg–Euler paper on the full nonperturbative one-loop effective action for quantum electrodynamics I review their paper and discuss some of the impacts it has had on quantum field theory.
CASIMIR EFFECT: THEORY AND EXPERIMENTS
Authors: LAMBRECHT ASTRID , REYNAUD SERGE
Published: June 2012

The Casimir effect is a crucial prediction of Quantum Field Theory which has fascinating connections with open questions in fundamental physics. The ideal formula written by Casimir does not describe real experiments and it has to be generalized by taking into account the effects of imperfect reflection, thermal fluctuations, geometry as well as the corrections coming from surface physics. We discuss these developments in Casimir physics and give the current status in the comparison between theory and experiment after years of improvements in measurements as well as theory.
REPULSIVE CASIMIR EFFECTS
Authors: MILTON K. A. , ABALO E. K. , PARASHAR PRACHI , POURTOLAMI NIMA , BREVIK IVER , ELLINGSEN S. Å.
Published: June 2012

Like Casimir's original force between conducting plates in vacuum, Casimir forces are usually attractive. But repulsive Casimir forces can be achieved in special circumstances. These might prove useful in nanotechnology. We give examples of when repulsive quantum vacuum forces can arise with conducting materials.
NEW CONSTRAINTS ON YUKAWA-TYPE INTERACTIONS FROM THE CASIMIR EFFECT
Authors: MOSTEPANENKO V. M. , BEZERRA V. B. , KLIMCHITSKAYA G. L. , ROMERO C.
Published: June 2012

Measurements of the Casimir force are used to obtain stronger constraints on the parameters of hypothetical interactions predicted in different unification schemes beyond the Standard Model. We review new strong constraints on the Yukawa-type interactions derived during the last two years from recent experiments on measuring the lateral Casimir force, Casimir force in configurations with corrugated boundaries and the Casimir–Polder force. Specifically, from measurements of the lateral Casimir force compared with the exact theory the strengthening of constraints up to a factor of 24 millions was achieved. We also discuss further possibilities to strengthen constraints on the Yukawa interactions from the Casimir effect.
COSMIC STRINGS STABILIZED BY FERMION FLUCTUATIONS
Authors: WEIGEL HERBERT , QUANDT MARKUS , GRAHAM NOAH
Published: June 2012

We provide a thorough exposition of recent results on the quantum stabilization of cosmic strings. Stabilization occurs through the coupling to a heavy fermion doublet in a reduced version of the standard model. The study combines the vacuum polarization energy of fermion zero-point fluctuations and the binding energy of occupied energy levels, which are of the same order in a semiclassical expansion. Populating these bound states assigns a charge to the string. Strings carrying fermion charge become stable if the Higgs and gauge fields are coupled to a fermion that is less than twice as heavy as the top quark. The vacuum remains stable in the model, because neutral strings are not energetically favored. These findings suggest that extraordinarily large fermion masses or unrealistic couplings are not required to bind a cosmic string in the standard model.