bluuebunny/crossref_metadata_2025 huggingface dataset:
Educating Engineering Students on Probabilistic Risk: Effects on the Perception of Ethics, Professional Responsibility, and Personal Agency
Authors: Gernand Jeremy M.
Published: March 2016

To better understand how improved understanding of uncertainty and probability concepts in an engineering systems context would affect undergraduate engineering students’ perceptions of professional responsibility and ethics as well as personal agency (one’s ability to affect the outcome of events), an assessment of these principles was conducted during a related course.

A course entitled Engineering Risk Analysis was offered and conducted with a mix of undergraduate Mechanical Engineering, Chemical Engineering, Petroleum Engineering, Environmental Systems Engineering, and Architectural Engineering students. This course presented and trained students in the use of system analysis techniques from the disciplines of Reliability Engineering, Policy Analysis, and Economics for understanding how uncertain circumstances interact with technological systems to produce failures and disasters.

As engineering systems become increasingly complex and command greater quantities of energy, the risk of failures even when very rare, become much more severe. While there have been previous initiatives to increase engineering students’ understanding of statistics, probability, and risk, usually in response to previous disasters, this preliminary study is the first to begin to examine how this kind of knowledge affects engineering student’s perceptions of ethics, responsibility, and their concept of how their own individual decisions affect the potential for the failure of complex systems and the consequences of such failures.

Students completed 5 regular survey-based assessments to judge their qualitative and quantitative skills, personal perceptions of the causes of engineering failures, and the professional and ethical responsibilities of engineers. Analysis of the response variance and a linear regression model demonstrated some significant effects after controlling for education, age, and professional work experience.

Results indicate that questions related to probabilistic understanding of risk demonstrated the most significant change during the course. Indicators of agreement with strong professional ethics and greater professional responsibility as well as personal agency did not significantly change during the course. More importantly, while personal choices on risk did not appear to reflect one’s view of how engineers actually do or should treat questions of risk professionally, the amount of previous technical work experience showed a small positive association with increased agreement on statements of ethical responsibility towards workers and the public. These findings suggest that future research is needed to assess the types of instruction and personal experience that can best encourage the combination of strong ethical responsibility and personal agency that could empower engineering students to act when they have the opportunity to reduce risk to workers, the public, or the environment.
Assessment of Pulsatile Blood Flow Models for the Descending Aorta Using CFD
Authors: Kamrath Benjamin D. , Suess Taylor N. , Gent Stephen P.
Published: March 2016

The objective of this research is to develop a computational fluid dynamics (CFD) model of a healthy human aorta from the aortic arch to the femoral arteries to allow for a better understanding of blood flow characteristics in this significant vessel. The increasing number of patients suffering from vascular diseases has accelerated the research in this field. Pulsatile blood flow through the descending aorta has numerous mechanisms that influence the flow characteristics, including non-Newtonian fluid effects, transient effects of the cardiac cycle, and geometries within the aortic vessel, among others. Although CFD has been used to predict flow effects of rather complicated systems, the use of CFD in vascular flow is still largely not understood. This paper compares non-Newtonian fluid effects in the flow of a natural aorta as well as flow effects within the descending aorta, including the ostium flow diverter, which regulates blood flow from the aorta to the renal arteries and was discovered within the last five years. Utilizing Creo Parametric, a 3-dimensional representation of the aorta was created including physical portrayals of the renal, superior mesenteric, common iliac and celiac arteries. This geometry was imported, meshed, and analyzed using a commercially available CFD solver. Using fluid properties of blood previously characterized in prior research, pulsatile flow models were investigated using constant viscosity and the Carreau-Yasuda Non-Newtonian viscosity model. This research compares the Oscillating Shear Index results of the constant viscosity model versus non-Newtonian. Shear stress and velocity profiles are used to study the effects of each assumption on the flow of blood through the descending aorta. This will be done by using a scalar result of the shear stress and the calculated Oscillating Shear Index. Based on previous work, the boundary layers created at the entrance of the renal arteries should be reduced by the presence of the ostium flow diverter. The model with the ostium flow diverter is used in both simulations. Ultimately, the simulation may predict the effects of changes or interventions to the descending aorta caused by assuming constant viscosity or non-Newtonian.
Education 3.0: Transforming Teaching and Learning by Eliminating Lecturing
Authors: Lee Tae-Eog , Cho KiSoon , Kim Eun-Jee
Published: March 2016

Lecturing has been effective for mass education. However, its limitations for learning effectiveness have been well known. Many innovative pedagogies have been developed for increasing interaction and student participation in classes. However, they have not been successfully adopted in most classrooms. On the other hand, the gap on educational quality between the industry and the academia, which is mostly attributable to lecture-based education, has been expanding. We propose a simple and effective strategy to transform teaching and learning to be highly interactive and student-participative by eliminating lecturing from classrooms. After sending lecturing to e-learning, teachers do non-lecturing activities including discussion, Q&A, interactive problem solving, team learning, and labs. We share strategies, feedback, and experiences from a university-wide program for implementing such new teaching and learning.
OrigamiBot-II: An Amphibious Robot With Reconfigurable Origami Wheels for Locomotion in Dynamic Environments
Authors: Jeong Donghwa , Lee Kiju
Published: March 2016

This paper presents a mobile robot with reconfigurable origami wheels, called OrigamiBot-II. The origami wheels, based on the twisted tower design, can contract and extend the width and therefore suitable for amphibious locomotion in an unknown, possibly dynamic, environment. The mechanical design focused on achieving locomotion on various types of ground and water surfaces. To establish wireless communication between the robot and a remote base or another robot, radio frequency (RF) based techniques were investigated and tested for both ground and water environments. The locomotion performance of Origamibot-II was evaluated in two ways: simulations using Gazebo integrated with Robot Operating System (ROS) and physical experiments on various types of surfaces. The simulations showed that the robot moves faster with contracted wheels on a smooth surface than with extend wheels, while expanded wheels provides more traction on a rugged terrain, such as asphalt, than contracted wheels. Physical experiments supported the simulation results and further demonstrated the robot’s amphibious locomotion capability by successfully maneuvering on a variety of ground environments and water surfaces.
Ascertainment of the Archetype Statistical Method for Incident Rate Forecasting Through Forecast Performance Evaluations
Authors: York Jason C. , Gernand Jeremy M.
Published: March 2016

The potential benefits of a safety program are generally, only realized after an incident has occurred. Resource allocation in an organization’s safety program has the imperative task of balancing costs and often unrealized benefits. Management can be wary to allocate additional resources to a safety program because it is difficult to estimate the return on investment, especially since the returns are a set of negative outcomes not manifested.

One way that safety professionals can provide an estimate of potential return on investment is to forecast how the organizations incident rate can be affected by implementing the different resource allocation strategies, and what the expectation for the incident rate would have been without intervention. Safety professionals often trend the performance of their organization’s safety program by benchmarking incident rates against other organizations. Previous studies have employed different statistical forecasting methods to predict how incident rates will react to changes in resource allocation.

This paper analyzes the performance of four statistical forecasting methods employed in previous resource allocation studies along another statistical forecasting method, never before used for incident rate prediction, to ascertain the method that provides the highest level of forecast accuracy. By identifying the most accurate forecasting method, the uncertainty of which method a safety professional should utilize for incident rate prediction is reduced. Incident data from the Mine Safety and Health Administration (MSHA) Part 50, was used to forecast both short and long term incident rates. The performance of each of these forecasting methods were evaluated against one another to determine which method has the highest level of accuracy, lowest bias, and best complexity-adjusted goodness-of-fit metrics.

Evaluation of the performance provides indications that the double exponential smoothing statistical forecasting method can provide the most accurate incident rate predictions. Analysis of forecast bias indicated that the error for the double exponential smoothing method is unbiased, within the acceptable range for tracking signal, and had a level of prediction accuracy above 70%. The results of this observational study indicate that the double exponential smoothing method should be the method to consider for incident rate prediction. Consistent use of the same forecasting methodology amongst safety professionals as part of their safety program’s resource allocation process, will allow for more consistent benchmarking of incident rate prediction.
Shell Element Formulation Based Finite Element Modeling, Analysis and Experimental Validation of Incremental Sheet Forming Process
Authors: Sahu Govind N. , Saxena Sumit , Jain Prashant K. , Roy J. J. , Samal M. K. , Tandon Puneet
Published: March 2016

This paper presents the effect of shell element formulations on the response parameters of incremental sheet metal forming process. In this work, computational time, profile prediction and thickness distribution are investigated by both finite element analysis and experimentally. The experimental results show that the thickness distribution is in good agreement with the results obtained with Belytschko-Tsay (BT) and Improved Flanagan-Belytschko (IFB) shell element formulations. These two shell element formulations do trade-off between computational time and accuracy. For more accurate results, the BT shell element formulation is better and for less computational time with good results, the IFB shell element is preferable. Finally, BT shell element formulation has been chosen for FE Analysis of ISF process in HyperWorks, since the results of thickness distribution and profile prediction is in better agreement with the experimental results as well as the computational time is less among the shell elements.
Finite-Time-Disturbance-Observer-Based Tracking Control of DC Motors With Velocity Constraint
Authors: Dong Z. L. , Yao J. Y. , Xu Z. B. , Ma D. W.
Published: March 2016

The integration design of high tracking performance and velocity constraint for dc motors is present in this paper. When designing advanced controllers for dc motors, it would be best to take the constraint of output velocity into consideration due to performance and/or physical limitations. A barrier Lyapunov function, which grows to infinity when its arguments approach some pre-set limits, is utilized to prevent constraint violation. By ensuring the stabilization of the barrier Lyapunov function, and imposing a hard-bound on associated error signals through the steps of the backstepping design procedure, the system output velocity constraint is guaranteed to be not transgressed. However, potential disturbances, including unmodelled dynamic effects, parametric uncertainties and external disturbances may destroy above theoretical results and degrade the tracking performance. In this paper, a finite time disturbance observer is employed and integrated with the barrier Lyapunov function based backstepping design to achieve the asymptotic tracking without the violation of the velocity constraint meanwhile overcoming the disturbances. Extensive simulation results are provided to illustrate the performance of the proposed control strategy.
Position and Weight Activated Passive Knee Mechanism
Authors: Ramakrishnan Tyagi , Lahiff Christina-Anne , Marroquin Asgard Kaleb , Reed Kyle B.
Published: March 2016

The human knee is a complex and robust system. It is the most important joint for human gait because of its immense load bearing ability. The loss of such an important joint often makes it difficult for a person to ambulate. Because of this and the resulting unnatural application of forces, many trans-femoral amputees develop an asymmetric gait that leads to future complications. Prosthetic knees are required to be well-designed to cope with all variabilities. There have been many prosthetic knee designs, some more complex than others. This paper describes the design and preliminary testing of a novel passive position and weight activated knee locking mechanism for use in lower limb prosthetics. This knee mechanism is designed to be a simple and economical alternative to existing knee mechanisms. The mechanism utilizes the dynamics of the user to lock the knee during stance and unlock during the swing phase. The presence of one moving component and a simple assembly makes this design a good base for customization. Results from testing the knee mechanism shows trends that are different from a normal human knee, which is to be expected. The prosthetic knee is designed to have low friction during swing of the shank and, hence, the flexion and extension angles and angular velocities are larger compared to a normal knee. The kinematics show a cyclic trend that is highly repeatable. Further refinement and testing can make this mechanism more efficient in mimicking a normal knee.
Analysis of Power and Specific Cutting Energy Consumption in Orthogonal Machining of Al 6061-T6 Alloys at Transitional Cutting Speeds
Authors: Warsi Salman S. , Jaffery Hussain I. , Ahmad Riaz , Khan Mushtaq , Akram Sohail
Published: March 2016

Recent researches in machining have revealed that electricity consumption of machine tools accounts for 90% of their environmental impact. Therefore, minimization of energy consumption will not only enhance its economic viability but will also reduce CO2 emissions. Most energy consumption studies present in literature focus on machining at low speeds (up to 500 m/min), whereas the specific cutting energy and power consumption trends at higher speeds have not been thoroughly investigated. This study analyses energy consumption in the machining of aluminium alloy Al-6061 T6 at high cutting speeds (up to 1000m/min and feeds up to 0.4 mm/rev). Full factorial experiments with three replicates were performed for orthogonal machining of AL-6061 T6 alloy which is one of the widely used materials in aerospace, automobiles, defence, sports and biomedical industries. A strict power measurement protocol was followed in accordance with CO2PE! (Cooperative Effort in Process Emission) proposed taxonomy. All the experiments were performed by unused inserts, therefore tool wear effect was not considered for power and energy calculations. The results were analysed using ANOVA and the contribution of speed and feed on energy consumption were quantified. Energy consumption map was prepared for varied speeds and feeds that revealed the presence of the optimum energy zones.
Data Analytics Pipeline for Prediction and Decision Making in Complex Products and Systems Development
Authors: Opiyo Eliab Z.
Published: March 2016

Facilitating data analytics for effective prediction in complex products or systems development is the focus of the research described in this paper. The specific objective was to develop strategies and a data analytics pipeline with a view to supporting exploration of the design space of complex products or systems upfront. The underlying challenges tackled included how to acquire and store raw data gathered by using both the traditional methods and advanced Internet of Things (IoT) devices, how to preprocess and transform raw data into a form suited for data analytics, and how to deal with analytics. A pipeline for data analytics to support decision making in complex products or systems development is proposed and its applicability illustrated with a practical example. The incorporation of advanced analytics techniques into the proposed pipeline allows users to acquire data and to insightfully and intelligently predict aspects such as cost and assembly time early on, and to make decisions based on data that may otherwise deemed to be inaccessible or unusable. This work contributes to the efforts directed toward applying data analytics techniques in a way that can have a profound impact on an engineering product or system development process.
Optimal Positions for Multiple Flexoelectric Actuations on Beams
Authors: Deng B. L. , Li H. , Tzou H. S.
Published: March 2016

Inhomogeneous electric field induces internal stress in flexoelectric materials, which is known as the converse flexoelectric effect. The atomic force microscope (AFM) probe can be applied to actuate the flexoelectric patch laminated on flexible structures and, in turn, induce structural vibrations. In this study, multiple actuators (i.e., combination of multiple AFM probes and flexoelectric patches) are used to suppress the vibration of an elastic cantilever beam. The displacement of the beam under control is obtained by superposition of a mechanical force induced part and an actuator induced part. The optimal actuator positions are selected when the minimal tip displacement of the cantilever beam is achieved. In case studies, only three actuators are used and only first three beam modes are considered. Under resonance conditions where only one mode participates, the optimal positions are obtained and they only depend on the relationship between actuation factor and actuator’s position. The influence of the patch length is discussed, followed by the analysis of control voltages applied to actuators. When the control voltage is so small as to the induced displacement is far less than that induced by the mechanical force, the optimal actuation positions do not vary with the voltage magnitude; while when the voltage is relatively large the actuators keep adjusting their relative optimal positions with respect to the control voltage and the system becomes unstable. Furthermore, as long as the control voltage is relatively small below the stability threshold, the optimal positions do not change as the position where mechanical force placed along the beam. Under the small voltage condition, a smooth relationship between optimal positions and vibration frequency is obtained. There are four jump points of optimal positions and they are related to the tip displacement-actuator position curves under different frequencies. This study serves as the foundation of flexoelectric vibration control with multiple AFM/flexoelectric actuators on flexible structures.
Combustion-Driven Oscillation Mitigation in Large Industrial Combustors
Authors: Kashani Reza
Published: March 2016

Thermoacoustic instability has been reported in various combustion systems including industrial combustors (heaters, boilers, etc.), propulsion systems (rockets, afterburners) and gas turbine combustors. Thermoacoustic instability can be addressed by adding acoustic damping to the combustion environment. In larger industrial applications, tonal acoustic damping solutions such as quarter wave tubes and/or Helmholtz resonators or even active acoustic damping solutions can be used to quiet this instability.

This paper discusses the numerical investigation of mitigating the 30 Hz thermoacoustic instability in a fire-tube 600 horsepower steam boiler. By conducting finite element analysis of the acoustics of the combustion chamber and all the fire-tubes, the 30 Hz mode sympathizing with the heat release dynamics of the chamber is identified. Subsequently, a number of tuned acoustic absorption solutions are experimented with, numerically (on the finite element model of the boiler’s acoustics), and the most suitable (in terms of effectiveness and ease of implementation) candidate solution is identified. Currently, work is underway to implement this solution on the boiler.
Child Resistant Closure Performance Aging Study
Authors: McCarthy Roger L. , Brown Stuart B.
Published: March 2016

Child poisoning has been dramatically reduced by the introduction of child resistant (CR) closures on some common home chemicals and pharmaceuticals. However, “child resistance” (often mischaracterized as “child proof”) is a mechanical design property that is neither well understood nor supported by a body of theory, nor that can be specified from engineering first principles. Instead, child resistance is an empirically developed and verified closure mechanical property derived from closure testing with child subjects, as specified by regulations under the Poison Prevention Packing Act (PPPA). The authors report their longitudinal study of a specific Type III CR closure over a period of decades made with materials from different suppliers over time and using different injection molding tools. The study examines if the property of “child resistance” persisted and if it correlated with the mechanical specifications of the closure actually measured and controlled in the closure manufacturing process. This data is combined with the authors’ mechanical measurements of closure performance. Child resistance, being a complex, empirically tested property, cannot be regularly tested in the normal manufacturing environment. Despite minor manufacturing process and specification changes, if the mechanical specifications are appropriate (e.g. not intended to produce changes in CR mechanical properties) and with adequate quality control, the property of child resistance persists.
A Ventilation Cooling Solution to Improve Thermal Environment of High Energy Density Li-Ion Battery Packs
Authors: Li Zhiqiang , Fan Xiaowei , Wang Fang , He Dasi , Wei Shifei
Published: March 2016

This paper focuses on the cooling solution to a high energy density and large capacity Li-ion battery system which consist of four packs of 26650 cells. The cooling measure is a critical technology for many Li-ion battery systems especially that designed for hybrid electric vehicles, in which, high energy density within a limited space is very common in these systems. Both the safety and efficiency of Li-ion battery cells rely on the temperature which is under control of the battery thermal management system. In this study, temperature fields within battery boxes are simulated with the computational fluid dynamic (CFD) method. With the help of an airconditioner, a cooling solution is proposed for a relatively large dimensional, high energy density Li-ion battery cells array using by vehicles. Through the proposed solution, the maximum single-cell temperature is restricted to a reasonable level, and the maximum temperature difference throughout the battery system is also improved.
3D CFD Analysis of a Twin Screw Expander With Different Real Gas Models for R245fa
Authors: Papes Iva , Abdelli Lazhar , Degroote Joris , Vierendeels Jan
Published: March 2016

With the increasing importance of minimizing primary energy usage and complying with emission restrictions, a significant interest has been developed towards waste heat recovery from industrial processes. A large portion of this energy is available at low temperatures (350K–400K) but it can be relatively efficiently converted into mechanical power using an Organic Rankine Cycle (ORC). Twin screw expanders can be used as an alternative to turbines with their cheap production costs and well proven efficiencies. In this paper, 3D CFD simulations of a twin screw expander using R245fa as the working fluid are performed.

Since the fluid properties show big deviations when using the ideal gas equation of state (EoS), the flow problem has been evaluated using different real gas models. Thermodynamic parameters for the ideal gas EoS, the cubic Aungier Redlich-Kwong EoS and the CoolProp fluid database (open source) were compared in a preliminary study. After that, the models have been included through user-defined functions (UDFs) in ANSYS Fluent and were tested on 3D CFD calculations of a twin screw expander and a simplified expansion model.

Several performance indicators such as mass flow rates, pressure-volume diagrams and power output are used to compare different fluid models for R245fa. From the results of this study, it can be concluded that the ideal gas EoS shows big deviations going closer to the saturation vapor line and the deviation in power comparing to the Aungier Redlich-Kwong EoS is around 8%. Conversely, the Aungier Redlich-Kwong EoS and the CoolProp database present very similar results for this case.
Comprehensive Evaluation of Some Innovative Wind Turbines
Authors: Kulkarni Swanand , Dabeer Prakash , Kale Sandip , Sawant Suresh M.
Published: March 2016

A rapid development in wind turbine technology took place during the Second World War and oil crisis of 1973. It continued during twentieths century, which resulted in turbines with bigger size and more advanced technology. Today, large wind turbines are becoming more competitive in the field of electricity generation because of economical production of electricity and availability at rural and remote locations. They have occupied remarkable share in world renewable power generation among various renewable energy sources. On the other hand small wind turbines are not accepted well because of lack of assured performance, cost, efficiency, etc. Therefore some researchers are trying to develop new wind turbine systems to convert wind energy in to electricity. Innovations in the design wind turbine to make them compatible for household use and also to favor their installations by building more eye-catching, efficient and economical wind turbine. To increase acceptability of wind turbines, wind turbine should satisfy the most of the criteria listed in the present study such as, ability to catch the wind from all the direction, self starting, light weight, inexpensive, maintenance free, low weight tower-top system and hence supporting structure, light weight and efficient generator, efficient wind to mechanical energy conversion and manufacturing simplicity at affordable cost and reliable performance. Present study focused on the innovative wind turbines that installed as an offshore and onshore technology. There are more than one hundred of different innovative wind turbine designs listed research papers, books, magazines and internet. In present paper, innovative design aspects of some of these turbines discussed with the technological challenges. Innovations are in the area of blade profile design, aerodynamic shape of the wind turbine, reduction of noise and vibrations, the material of the blade, mechanical and electronic instruments such as gearbox and electronic power circuit, suitability to the application, etc. The aims of these innovations are improvement in the efficiency of the wind turbine; increase in power output and to lower the overall cost. At the end of paper the technological challenges that these innovations overcome, innovative concept and feasibility of the concept are discussed. These innovations include spiral wind turbine, VAWT with accelerator, Windpax-Collapsible portable wind turbine, multi-rotor wind turbines, diffuser augmented wind turbines and floating wind turbines.
Numerical and Experimental Study of Flow Phenomenon Inside Gas Ejectors With Moist Gases Entrainment
Authors: Wang Yuping , Pellerin Mark , Mohanty Pravansu , Sengupta Subrata
Published: March 2016

Gas ejectors can be found in a wide range of applications such as refrigeration and thrust augmentation. This paper focuses on the study of an ejector used in applications where moist gases are being entrained. In the first part of this work, the gas flow characteristics inside an ejector, as well as the ejector’s performance under various operating and geometric configurations, were studied with a three-dimensional computational model, which was validated against measurement data.

In the second part, focus was given to the potential condensation or de-sublimation phenomena that may occur inside an ejector when water vapor is included in the entrained stream. An experiment using light-attenuation method was performed to verify the presence of a second phase, then the onset of phase change and the phase distribution were obtained numerically. A two-dimensional axis-symmetric model was developed based on the model used in the first part. A series of simulations were performed with various amounts of water vapor added into the entrained flow. It was found that both frost particles and water condensate could form inside the mixing tube depending on the operating conditions and water vapor concentrations. When the concentration exceeds 3%, water vapor could condense throughout the mixing tube. Some preliminary results of the second phase particles formed, e.g. critical sizes and distributions, were also obtained to assist with the design and optimization of gas ejectors used in similar applications.
Configuration Rules for Assembly Line Layouts: An Integrated Approach for the Preliminary Design
Authors: Furini Francesco , Ascheri Andrea , Colombo Giorgio , Ippolito Massimo , Atzeni Eleonora
Published: March 2016

The design and the configuration of manufacturing systems, such as assembly lines layouts, are time consuming activities, mainly based on implicit knowledge and no definite rules. This complicated design process is associated with high costs, long lead times and high probability of risks and reworks. Knowledge Based Engineering (KBE) is a technique that can tackle these issues and support the engineers in the early design steps of a manufacturing system with a comprehensive and systematic approach, into the integrated design in a complex system and its related processes. The purpose of this research involve the use of KBE methodology in order to collect and formalize knowledge about the a case study, the design of an assembly line layout system for the cylinder head valve of a car engine. With the formalization of the case study is possible to create an application of configuration that supports the decision making process during the preliminary design phase. The possibility to extend the process to a multi objective optimization is considered. The methodology should be able to help manufacturing equipment providers to shrink design times, evaluating more alternatives and integrating different activities related to the preliminary design phase of a system. This research proposes a practical approach combining the current research state of the art and a real industrial environment for knowledge extraction and application.
Sensitivity Evaluation of the AGR 3-4 Experiment Thermal Model Irradiated in the Advanced Test Reactor
Authors: Hawkes Grant L. , Sterbentz James W. , Pham Binh T.
Published: March 2016

A temperature sensitivity evaluation has been performed on a thermal model for the AGR-3/4 fuel experiment on an individual capsule. The experiment was irradiated in the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL). Four TRISO fuel irradiation experiments are planned for the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program which supports the development of the Very High Temperature Gas-cooled Reactor under the Next-Generation Nuclear Plant project.

AGR-3/4 is the third TRISO-particle fuel test of the four planned and is intended to test tri-structural-isotropic (TRISO)-coated, low-enriched uranium oxy-carbide fuel. The AGR-3/4 test was specifically designed to assess fission product transport through various graphite materials. The AGR-3/4 irradiation test in the ATR started in December 2011 and finished in April 2014. Forty-eight (48) TRISO-particle fueled compacts were inserted into 12 separate capsules for the experiment (four compacts per capsule).

The purpose of this analysis was to assess the sensitivity of input variables for the capsule thermal model. A series of cases were compared to a base case by varying different input parameters into the ABAQUS finite element thermal model. These input parameters were varied by ±10% to show the temperature sensitivity to each parameter. The most sensitive parameter was the compact heat rates, followed by the outer control gap distance and neon gas fraction. Thermal conductivity of the compacts and thermal conductivity of the various graphite layers vary with fast neutron fluence and exhibited moderate sensitivity. The least sensitive parameters were the emissivities of the stainless steel and graphite, along with gamma heat rate in the non-fueled components. Separate sensitivity calculations were performed varying with fast neutron fluence, showing a general temperature rise with an increase in fast neutron fluence. This is a result of the control gas gap becoming larger due to the graphite shrinkage with neutron damage. A smaller sensitivity is due to the thermal conductivity of the fuel compacts with fast neutron fluence.

Heat rates and fast neutron fluence were input from a detailed physics analysis using the Monte Carlo N-Particle (MCNP) code. Individual heat rates for each non-fuel component were input as well. A steady-state thermal analysis was performed for each sensitivity calculation. ATR outer shim control cylinders and neck shim rods along with driver fuel power and fuel depletion were incorporated into the physics heat rate calculations. Surface-to-surface radiation heat transfer along with conduction heat transfer through the gas mixture of helium-neon (used for temperature control) was used in the sensitivity calculations.
Addressing Thermal Management Concerns for a Power Electronics Module Using an Integrated Micro-Cooling Chip Array Scheme
Authors: Papadopoulos George , Kearney Daniel
Published: March 2016

The field of consumer and power electronics is surging ahead with more sophisticated and powerful devices that are smaller and more capable than before. Proper and efficient thermal management of such devices is increasingly challenging when addressing requirements to reduce size, weight and cost (both manufacturing and operational) while enabling the overall system to operate at higher power densities. The current effort investigates an integrated micro-cooling chip array scheme to address the local thermal management challenges of a baseline power electronic invertor circuit. The chip array is a multi-laminate design that features localized fluidic cells ducted to bring single phase coolant in and out of a heat exchanger section. This paper focuses on a the micro-jet array scheme to address high, localized and spatially varying heat fluxes that may result from a nominal power electronics three-phase inverter module. The design approach considers manufacturability and optimization of the effective cooling performance of the micro-jet array adjacent to the power electronic module. A detailed analysis of the heat exchanger section is performed and the computational results identify the local minimum thermal resistance, the effect of increasing mass flow rate and pumping power and the achievable improvement in heat transfer with a simplistic pin array enhancement.
Technical and Economical Investigation of Wind Power Potential in Kuwait
Authors: Gharbia Yousef A. , Ayoub Haytham
Published: March 2016

The State of Kuwait is considering diversifying its energy sector and not entirely depend on oil. This desire is motivated by Kuwait commitment to reducing its share of pollution, as a result of burning fossil fuel, and to extend the life of its oil and gas reserves. The potential for solar energy in Kuwait is quite obvious; however, it is not the case when it comes to wind energy. The aim of this work was to analyze wind data from several sites in Kuwait and assess their suitability for building large-scale wind farms. The analysis of hourly averaged wind data showed that some sites can have an average wind speed as high as 5.3 m/s at 10 m height. The power density using Weibull distribution function was calculated for the most promising sites. The prevailing wind direction for these sites was also determined using wind-rose charts. The power curves of several Gamesa turbines were used in order to identify the best turbine model in terms of specific power production cost. The results showed that the area of Abraq Al-Habari has the highest potential for building a large-scale wind farm. The payback period of investments was found to be around 7 years and the cost of electricity production was around US Cent 4/kWh.
Simulation on Leakage and Dynamic Characteristics of Leaf Seal
Authors: Han Jie
Published: March 2016

This paper aims to summarize the design principles of traditional leaf seal, and to propose a future innovative use of the charts from the paper. FLUENT 15.0 was used to find the relation between leakage and clearances; the effect of similar parameters on leakage were compared. ABAQUS 6.13 was used to post-process FLUENT pressure field to find the relation between leaf-motion and clearances; the effect of similar parameters on leaf-motion were compared. The results show downstream parameters have greater impact than upstream parameters on leakage. For the leaf movements: increase downstream parameters can lessen the down-motion or increase the up-motion; increase the upstream parameters can strengthen the down-motion. Increase Leaf-axis gap can lessen the up-motion or increase the down-motion. By referring to the motion curve, on-time control can be introduced by designing the seal with movable structures to lower leakage and abrasion.
Optical Flow Measurement of Cavitation in a Converging-Diverging Nozzle Using High-Speed Imagery
Authors: Duong Alan
Published: March 2016

Cavitation is a phenomenon where liquids will vaporize when subjected to low pressures. Essentially, the pressure is reduced sufficiently such that the liquid boils at the given temperature. The highest pressure at which cavitation could occur is called the vapor pressure. However, the pressure associated with the onset of cavitation could be lower than the vapor pressure. This indicates the liquid exists under a meta-stable condition.

The current research is investigating different aspects of cavitation and cavitating flow characteristics. Particle tracking using high-speed photography provided further insight as to what the velocity profile of cavitating flow may resemble. The research has shown that the cavitation that occurred in the current nozzle appears to have a laminar velocity profile. In the experiments that were conducted, it was also observed that as the back pressure of the downstream decreased, the volumetric flow rate would increase. However, a maximum volumetric flow rate was measured once the flow had begun cavitation regardless of the back pressure. This indicated that choked flow conditions likely exist within the nozzle. Choked flow within the nozzle indicates that near the region of the throat the fluid velocity has reached the speed of sound. Using high-speed photography, visualization of flow separation and recirculation was recorded.

The information obtained from the research provides a more detailed description of the velocity profile near the onset of cavitation. The main objectives of this research were to obtain measurements of the overall flow for support of on-going research and analysis of nozzle flow cavitation. This study will provide a foundation for further and more detailed research into cavitation phenomena.
Comparison of three dimensional strain volume reconstructions using SOUPR and wobbler based acquisitions: A phantom study
Authors: Yang Wenjun , Ingle Atul , Varghese Tomy
Published: March 2016

Purpose:

Ultrasound strain imaging is a relatively low cost and portable modality for monitoring percutaneous thermal ablation of liver neoplasms. However, a 3D strain volume reconstruction from existing 2D strain images is necessary to fully delineate the thermal dose distribution. Tissue mimicking (TM) phantom experiments were performed to validate a novel volume reconstruction algorithm referred to as sheaf of ultrasound planes reconstruction (SOUPR), based on a series of 2D rotational imaging planes.

Methods:

Reconstruction using SOUPR was formulated as an optimization problem with constraints on data consistency with 2D strain images and data smoothness of the volume data. Reconstructed ablation inclusion dimensions, volume, and elastographic signal to noise ratio (SNRe) and contrast to noise ratio (CNRe) were compared with conventional 3D ultrasound strain imaging based on interpolating a series of quasiparallel 2D strain images with a wobbler transducer.

Results:

Volume estimates of the phantom inclusion were in a similar range for both acquisition approaches. SNRe and CNRe obtained with SOUPR were significantly higher on the order of 250% and 166%, respectively. The mean error of the inclusion dimension reconstructed with a wobbler transducer was on the order of 10.4%, 3.5%, and 19.0% along the X, Y, and Z axes, respectively, while the error with SOUPR was on the order of 2.6%, 2.8%, and 9.6%. A qualitative comparison of SOUPR and wobbler reconstruction was also performed using a thermally ablated region created in ex vivo bovine liver tissue.

Conclusions:

The authors have demonstrated using experimental evaluations with a TM phantom that the reconstruction results obtained with SOUPR were superior when compared with a conventional wobbler transducer in terms of inclusion shape preservation and detectability.
Validity and Reliability of Two Field-Based Leg Stiffness Devices: Implications for Practical Use
Authors: Ruggiero Luca , Dewhurst Susan , Bampouras Theodoros M.
Published: March 2016

Leg stiffness is an important performance determinant in several sporting activities. This study evaluated the criterion-related validity and reliability of 2 field-based leg stiffness devices, Optojump Next® (Optojump) and Myotest Pro® (Myotest) in different testing approaches. Thirty-four males performed, on 2 separate sessions, 3 trials of 7 maximal hops, synchronously recorded from a force platform (FP), Optojump and Myotest. Validity (Pearson’s correlation coefficient, r; relative mean bias; 95% limits of agreement, 95%LoA) and reliability (coefficient of variation, CV; intraclass correlation coefficient, ICC; standard error of measurement, SEM) were calculated for first attempt, maximal attempt, and average across 3 trials. For all 3 methods, Optojump correlated highly to the FP (range r = .98–.99) with small bias (range 0.91–0.92, 95%LoA 0.86–0.98). Myotest demonstrated high correlation to FP (range r = .81–.86) with larger bias (range 1.92–1.93, 95%LoA 1.63–2.23). Optojump yielded a low CV (range 5.9% to 6.8%), high ICC (range 0.82–0.86), and SEM ranging 1.8–2.1 kN/m. Myotest had a larger CV (range 8.9% to 13.0%), moderate ICC (range 0.64–0.79), and SEM ranging from 6.3 to 8.9 kN/m. The findings present important information for these devices and support the use of a time-efficient single trial to assess leg stiffness in the field.
New Small Plasmid Harboring
bla
KPC-2
in Pseudomonas aeruginosa
Authors: Galetti Renata , Andrade Leonardo Neves , Chandler Michael , Varani Alessandro de Mello , Darini Ana Lúcia Costa
Published: March 2016

The aim of this study was to characterize the genetic context of
bla
KPC-2
in
Pseudomonas aeruginosa
sequence type 244 from Brazil. The
bla
KPC-2
gene was detected in a new small plasmid, pBH6. Complete sequencing revealed that pBH6 was 3,652 bp long and included the Tn
3
resolvase and Tn
3
inverted repeat (IR), a partial copy of IS
Kpn6
, and a putative
ori
region but no
rep
genes. pBH6 replicated stably into
Escherichia coli
strain DH10B and
P. aeruginosa
strain PAO.
Distribution and Relationships of Antimicrobial Resistance Determinants among Extended-Spectrum-Cephalosporin-Resistant or Carbapenem-Resistant Escherichia coli Isolates from Rivers and Sewage Treatment Plants in India
Authors: Akiba Masato , Sekizuka Tsuyoshi , Yamashita Akifumi , Kuroda Makoto , Fujii Yuki , Murata Misato , Lee Ken-ichi , Joshua Derrick Ian , Balakrishna Keshava , Bairy Indira , Subramanian Kaushik , Krishnan Padma , Munuswamy Natesan , Sinha Ravindra K. , Iwata Taketoshi , Kusumoto Masahiro , Guruge Keerthi S.
Published: March 2016

To determine the distribution and relationship of antimicrobial resistance determinants among extended-spectrum-cephalosporin (ESC)-resistant or carbapenem-resistant
Escherichia coli
isolates from the aquatic environment in India, water samples were collected from rivers or sewage treatment plants in five Indian states. A total of 446
E. coli
isolates were randomly obtained. Resistance to ESC and/or carbapenem was observed in 169 (37.9%)
E. coli
isolates, which were further analyzed. These isolates showed resistance to numerous antimicrobials; more than half of the isolates exhibited resistance to eight or more antimicrobials. The
bla
NDM
gene was detected in 14/21 carbapenem-resistant
E. coli
isolates:
bla
NDM-1
in 2 isolates,
bla
NDM-5
in 7 isolates, and
bla
NDM-7
in 5 isolates. The
bla
CTX-M
gene was detected in 112 isolates (66.3%):
bla
CTX-M-15
in 108 isolates and
bla
CTX-M-55
in 4 isolates. We extracted 49 plasmids from selected isolates, and their whole-genome sequences were determined. Fifty resistance genes were detected, and 11 different combinations of replicon types were observed among the 49 plasmids. The network analysis results suggested that the plasmids sharing replicon types tended to form a community, which is based on the predicted gene similarity among the plasmids. Four communities each containing from 4 to 17 plasmids were observed. Three of the four communities contained plasmids detected in different Indian states, suggesting that the interstate dissemination of ancestor plasmids has already occurred. Comparison of the DNA sequences of the
bla
NDM
-positive plasmids detected in this study with known sequences of related plasmids suggested that various mutation events facilitated the evolution of the plasmids and that plasmids with similar genetic backgrounds have widely disseminated in India.