bluuebunny/crossref_metadata_2025 huggingface dataset:
Computerized Database Decision Management System in Production Traveler Sheet
Authors: Dou Yangqing , Liu Yucheng
Published: June 2016

A production traveler sheet is a document which is filled by people, records how a product is manufactured and how many steps need to be followed during the process period. Problems arise when manual work is negatively impacted because production traveler sheet are either deficient, incomplete and time consuming. In this paper a production traveler sheet shows how aircraft skin is assembled and traveled. A lean tool, value stream mapping and computerized database management system were used to analyze the production traveler sheet for automatic assembling of aircraft skin. Through the application of lean concept and computer database system, lead time saving and manufacturing efficiency are obtained by reducing or eliminating non-value activities and process time.
Household Cooking Range Tipover Accident Reconstruction Case Study
Authors: Brickman Dennis B. , Sanders Steven A.
Published: June 2016

A safety engineering accident investigation was conducted to analyze the circumstances surrounding an unwitnessed household child fatality allegedly associated with a cooking range tipover. An accident reconstruction utilizing child dummies was performed to address various cooking range tipover scenarios. Results of the accident reconstruction case study indicate that the child’s death is inconsistent with a cooking range tipover event.
Results From Calculating the Acceleration at an ELR Using Measured Responses From Four Steering-Induced Rollover Crashes
Authors: Arndt Mark William , Wiechel John F.
Published: June 2016

Four steer-induced rollover crashes were analyzed by calculating the local three-dimensional accelerations at hypothetical seat positions’ Emergency Locking [seat belt] Retractor (ELR). The method for calculating the local acceleration was described in a recent Society of Automotive Engineers (SAE) paper and assumed three-dimensional rigid body motion, recorded acceleration and recorded roll rates at the center of gravity. For a threshold of 0.7 g, results demonstrated that intervals in the vehicle’s response that may cause the ELR’s inertial sensor to move into a neutral zone were limited to localized high-magnitude negative vertical acceleration events during the rollover segment with a maximum calculated duration of 31.7 ms. Changing the threshold to 0.35 g reduced the interval count by 70 percent and maximum duration by approximately 50 percent. Results of the analysis were consistent with prior published research that noted limited and brief periods of instances in rollover crashes when the inertial sensor may be in a neutral zone. Calculating an interval that a vehicle’s response may allow a retractor to move into a neutral zone did not mean that a specific retractor will move into a neutral zone. To asses if a specific retractor will move into a neutral zone its performance should be analyzed. As identified in prior research, occupant kinematics analysis was necessary in determining whether an inertial sensor in a neutral zone during a rollover event will result in belt spool out. It is beyond the scope of the paper to include a complete analysis of occupants’ kinematics.
Interface Integrity Evaluation of Explosively Welded Metallic Structures
Authors: Du Jikai , Jerred Christopher , Ladd Katrina M. , Delfanian Fereidoon
Published: June 2016

Explosively bonded tubes have been applied in high pressure and high temperature environments, such structures are usually consisting of dissimilar metals which are very difficult to be welded together by other conventional welding methods. In this study, various experimental techniques were used for the evaluation of interface integrity between steel major tube and tantalum donor tube. First, X-ray diffraction technique was used to profile the residual stress levels in the tantalum donor tube before bonding and steel major tube after bonding, especially the hoop stress level which is critical to quality control. Also, other experimental techniques including digital microscopy for interface geometrical features, X-ray fluorescence spectroscopy for interface compositions, and nano-hardness testing for materials strength at micro/nano scale were further applied to explain bonding mechanisms and to quantify bonding interface conditions. Then nondestructive ultrasound C-scan technique was used to create acoustic images of the bonding interfaces and the results showed that the technique has the potential to find weak interface and to further quantify good and poor bonds. Finally, destructive testing techniques were used to measure the interface shear and tensile strength and to study the interface failure mechanisms, and the results agree well with other experimental techniques.
Analysis of Influence of FCB Test on 1000MW Steam Turbine Safety
Authors: Xie Dan-mei , Yang Yi , Chen Chang , Hu Peng-fei , Guo Jie , Jiang Wei
Published: June 2016

The capacity of power grid in China increases rapidly. Because of the reliability of multi-infeed DC system in the grid, power system damping is relatively weak. Realizing isolated island operation of thermal power units with FCB (fast cut back) ability is considered to be the best solution of quick restoration of power grid. Taking a 1000MW USC (Ultra-supercritical) unit as an example, based on the data of the unit’s load refection tests, this paper conducts a look at several aspects of research: (1) predicting the maximum speed rise of rotor during FCB process with different loads by using Simulink; (2) predicting the water level of deaerator and condenser during FCB process with different loads by same method; (3) predicting the highest exhausted steam temperature of HP cylinder during FCB process with different loads by using FEM; (4) comparing these key parameters with FCB test data, it shows that the predicted results agree with test data very well. (5) analyzing the influence of FCB test on the safety and life loss of the thermal equipment.
Microstructural Characterization of Sm-Co Magnets
Authors: Victoria Patricia Iglesias , Yin Weimin , Gupta Surendra K. , Constantinides Steve
Published: June 2016

Samarium cobalt permanent magnets have been widely used for their excellent intrinsic magnetic properties such as very high Curie temperature, high anisotropy fields and most importantly excellent temperature coefficients of induction and coercivity. These materials have continuing industrial interest especially for applications operating at elevated temperatures and in the presence of high demagnetizing fields, such as particle accelerators, high frequency traveling wave tubes (TWTs), servo-motors and automotive and aerospace applications. An area of opportunity for improving performance of SmCo magnets is increasing magnet toughness — resistance to fracture.

Like all other sintered rare earth magnetic materials, SmCo magnets are based on intermetallic compounds which are intrinsically brittle and can crack in the course of fabrication, machine work, and installation in the application. Increased toughness would also reduce handling sensitivity of magnetized magnets. For many years, studies on SmCo magnets have been focused on their magnetic properties, but the mechanical characteristics, strengthening and toughening mechanisms have been rarely reported. Understanding the phase and structural transformations induced in the SmCo magnets during the manufacturing process offers insight into potential modifications — chemical or processing-related. In this study, microstructural characterizations of 1:5 and 2:17 Sm-Co magnets were carried out using optical and scanning electron microscopes. In scanning electron microscopy (SEM), backscattered electron imaging and energy dispersive X-ray (EDX) microanalysis were used to investigate different phases and oxides. Finally, crystal structure of the magnets was studied using an X-ray diffractometer (XRD). The study correlates the microstructure characterization with the thermal processing history of different grades of SmCo magnets.
Microstructure Evolution and Bond Formation at the Contact Interface During Ultrasonic Consolidation Process
Authors: Zhang Song , Zheng Lili , Zhang Hui
Published: June 2016

In this paper a cellular automata-finite elements (CAFE) model is developed by combining traditional finite elements (FE) model and cellular automata (CA) model. The microstructure under different process conditions of ultrasonic consolidation (UC) process for Al 7075 is studied. It is found that higher energy input process conditions (higher applied load and sonotrode oscillation amplitude, lower sonotrode travel speed) will lead to a higher value of dynamic recrystallization (DRX) fraction for UC deposited foils. The mean dislocation density of the UC deposited material will increase with the applied load while it decreases with the increase of sonotrode travel speed and oscillation amplitude.
Intermetallic Compound Formation in Al/Mg Friction Stir Welded (FSW) Butt Joints
Authors: El Chlouk Z. G. , Ayoub G. , Kridli G. T. , Hamade R. F.
Published: June 2016

In this work, friction stir welding (FSW) is used to produce butt joints of 3-mm-thick sheets of AZ31B magnesium alloy to two different aluminum alloys: AA1100 (minimum 99% aluminum) and AA6061 (97.9% Al). The paper reports on utilizing metallurgical techniques to determine the distribution profiles of elemental aluminum and magnesium within the joints were produced using energy dispersive x-ray spectroscopy (EDX). Furthermore, X-ray diffraction (XRD) was used to identify the intermetallic compounds that form in the joints as a result of the stirring action at processing temperatures. Measurements confirmed the presence of primary intermetallic compounds in the welded joints and were identified to be the α-phase (Al12Mg17) and the β-phase (Al3Mg2). Lastly, micro-hardness studies were conducted at the intermetallic-compounds-rich locations resulting in hardness profiles.
A Decade of Experience With Small Specimen Testing to Evaluate Mechanical Properties of Materials
Authors: Prakash Raghu V.
Published: June 2016

Small specimen testing has become popular in the recent times, due to the need for material property evaluation using limited volume samples available from processing techniques, scoop extraction of materials. There are several methods of direct and in-direct mechanical property evaluation such as: automated ball indentation, miniature tensile testing, small punch testing, shear punch testing and miniature specimen impact testing. Most of these techniques provide a correlation with standard specimen test data through empirical relationships.

This paper summarizes work done at the author’s Institution during the last decade on small specimen testing, with specific reference to spherical ball indentation (both static as well as cyclic indentation), shear punch and small punch testing on a number of metallic materials. Specific examples of how the material degradation due to prior damage (plastic deformation, fatigue, creep) are discussed.
Probabilistic Assessment of Fatigue Life in Fiber Reinforced Composites
Authors: Shiri Saeed , Pourgol-Mohammad Mohammad , Yazdani Mojtaba
Published: June 2016

In this paper, a stiffness-based model is initially assessed for fatigue damage analysis of composite structures. The model is evaluated with three sets of experimental data. A residual strength model is coupled to the choice model and a modified model is developed. Numerical results show that the modified model leads to improvement of predicted fatigue lives for two-stage loadings. To determine the variations of the predicted fatigue lives, probabilistic assessment is done by Monte-Carlo simulation. Normal distribution is fitted with good agreement to the histogram and empirical CDF of the numerical life predictions.
Characterization of Nitinol as a Servo-Biomimetic for Facial Muscles
Authors: Mestre Oliver , Riofrio Jose , Shin Moochul
Published: June 2016

This paper presents the electrodynamic characterization of Nitinol wire and investigates its potential as a servo-actuator that can be utilized to recreate complex low-power muscle movements, such as those in facial muscle groups. Nitinol (NiTi) is a type of shape memory alloy (SMA) which recovers its original length after experiencing large deformation when heated above an austenite finish temperature. This shape memory effect is associated with the phase transformation between the martensite phase and austenite phase. By varying a current through the Nitinol wire, its temperature can be accurately controlled and by extension so can its internal strain or stress. The purpose of this work is twofold: 1) to examine the causal relationships between current, temperature, strain and stress in the Nitinol wire, and 2) to demonstrate the feasibility of a simple closed-loop control system such that this type of wire can be used as a servo-actuator in both position control and force control applications. Experimental results show a basic level of servo-control, achieving successful position and force tracking of a command signal. These results demonstrate the feasibility of creating networks of Nitinol wires which can mimic complex motion patterns of certain facial muscle groups.
Mechanical Properties of Paper Thermosetting Resin Composites by Various Paper Materials
Authors: Kitamura Takanori , Zhang Qianjin , Ito Kanta , Teramura Suguru , Zhang Zhiyuan , Yang Yuqiu , Hamada Hiroyuki
Published: June 2016

Recycling and reusing is a noticeable method for environment protecting. Recycled paper is one of the most successful cases as it contributes to energy saving, low cost, low wood consumption and environmental protection. During paper recycling process, many different kinds of raw materials can be used. Paperboards made of different raw materials showed different properties. In this study, three kinds of raw materials were selected to fabricate paperboards respectively combining with thermosetting resin, paperboards reinforced plastic composite was laminated by hand layup method. Detailed observation were carried out to analysis the molding stations including the tensile property which was investigated on both unnotched and notched specimens, besides, to investigate the anisotropy, tensile test was conducted on the specimens both in machine rolling direction and transverse direction. SEM was also employed to observe the materials and fracture area respectively.
Dynamic Response of Polyvinyl Alcohol(PVA)-Hydrogel With Different PVA Concentrations
Authors: Han Changwan , Park Seonghun , Kim Hanjong
Published: June 2016

Polyvinyl Alcohol-Hydrogel (PVA-H) is a biomaterial used for manufacturing contact lenses as well as for the medium of drug delivery. Previous studies have also showed that PVA-H exhibits superior biocompatibility with hydrophilic elastic nature. The aim of this study is to examine the possible usage of the PVA-H as cartilage replacement material by determining the static and dynamic mechanical properties of PVA-H with different ratios of polyvinyl alcohol (PVA) and phosphate buffered saline (PBS) compositions.

Three different types of PVA-H specimens were made by changing the ratio of PVA (Sigma-Aldrich) and PBS (Sigma-Aldrich) compositions (PVA-H1: 10 wt% PVA and 90 wt% PBS; PVA-H2: 20 wt% PVA and 80 wt% PBS; PVA-H3: 25 wt% PVA, 45 wt% PBS and DMSO 30 wt%). Static and dynamic tensile tests under the loading frequencies of 0.001, 0.01, 0.1, and 1 Hz were carried out to measure the biomechanical properties of PVA-H1, -H2 within PBS solution and -H3 within PBS/ DMSO solution.

The equilibrium Young’s moduli (EY) of PVA-H1, -H2 and -H3 evaluated from the static displacement control were 84.2±35.1 kPa (n=10), 254±32.2 kPa (n=10) and 588±38.9 kPa (n=5), respectively. The amplitudes of dynamic tensile moduli were varied from 86.3±33.4 kPa (n=10) at 0.001 Hz to 96.9±42.0 kPa (n=10) at 1 Hz for PVA-H1, from 282.7±26.4 kPa (n=10) at 0.001 Hz to 309.1±32.2 kPa (n=10) at 1 Hz for PVA-H2 and from 643.8±49.8 kPa (n=10) at 0.001 Hz to 747.7±67.7 kPa (n=5) at 1 Hz for PVA-H3. According to the current results, the frequency dependence of the magnitude of the dynamic modulus confirms the viscoelastic nature of PVA-H material. However, it can be noted that the dynamic modulus increases by up to a factor of 1.15 for PVA-H1, 1.22 for PVA-H2 and 1.27 for PVA-H3, showing insignificant viscoelasticity compared with that for cartilage. The result that static and dynamic moduli of PVA-H3 are larger than those of PVA-H1 and PVA-H2 also suggests that the amount of PVA composition in PVA-H plays an important role in improving both static and dynamic mechanical strengths of PVA-H material. The phase angle decreased from 5.2±2.1 ° at 0.001 Hz to −0.3±1.7 ° at 1 Hz for PVA-H1, from 5.6±0.6 ° at 0.001 Hz to −0.3±0.7 ° at 1 Hz for PVA-H2 and from 8.2±1.1 ° at 0.001 Hz to 0.7±0.7 ° at 1 Hz for PVA-H3.
Lateral Compressive Properties of Paper Tube
Authors: Suda Mitsunori , Yang Jiahui , Kitamura Takanori , Ito Kanta , Wada Kenji , Zhang Zhiyuan , Yang Yuqiu , Hamada Hiroyuki
Published: June 2016

Recycled paper is helpful to reduce trash discharge, save resource and cost. Tube is one of the most common structures of recycled paper in application. It is an excellent choice for packing. It’s also used in the construction of temporary structures for both exhibition spaces or for rapid-recovery shelters in emergency operations. As paper tubes are laminated by paperboards which are inherent anisotropy materials, the researches on mechanical property and fracture behavior became complicated. In the current study, paperboards used for paper tubes were tested on universal testing machine to investigate their basis mechanical properties. Then, paper tubes fabricated with different kinds of paperboard and number of ply were used to investigate lateral compressive properties by Instron universal testing machine. And, a camera was employed to record the fracture process of paper tube during compression process. The fracture mechanism of paper tubes were discussed and analyzed during compressed process based on the load-displacement curves and detailed observation. Additionally, ls-dyna software was used to conduct numerical simulation and analyze stress distribution of paper tube during lateral compression.
Prediction of Transformation-Induced Residual Stresses During Gas Nitriding of H13 Steels Using Phase Field Approach
Authors: Akhtar Syed Sohail , Abubakar Abba Abdulhamid , Arif Abul Fazal M.
Published: June 2016

Gas nitriding is a common surface treatment practice to improve the wear resistance of AISI H13 hot extrusion die cavities. However, due to the presence of complex and sharp features of die cavities, it has been observed that non-uniform nitride layer develops in these regions. Moreover, the formation of compound layer in the surface vicinity of nitrided surfaces leads to the development of transformation-induced stresses. The present work presents the application of the phase field method in predicting the evolution of the nitride layers and associated residual stresses during the gas nitriding of AISI H13 tool steels. Nitriding process is modeled and simulated in line with experimental set-up which uses automated two-stage controlled nitriding process. Some representative samples having commonly used geometric features are manufactured and nitrided for validation purpose. Both experimental and numerical results are found in close agreement in terms of nitrogen concentration and corresponding micro-hardness profiles. The results show that high stresses are induced at the surface due to formation of the nitride layers and these stresses are found to be higher at the sharp corners. In view of the current results, some process and design strategies are suggested for improved and more effective nitriding treatment of hot extrusion dies used in the industry.
Vacuum Infusion for Processing Thermosetting Composites Containing High Loading Solid Fillers
Authors: Fang Xudong , Hong Yifeng , Bi Chao , Yao Donggang
Published: June 2016

A new processing route for making thermosetting materials and products containing high loading solid fillers including waste solid scraps and natural mineral fillers was investigated. Traditionally, solid fillers are incorporated into thermosetting polymers by liquid-state mixing. However, due to the high viscosity in mixing, high loading above 50% by weight is difficult to achieve. The new process overcomes this hurdle by a two-step processing strategy. First, solid fillers are placed in the mold and compacted to conform to the mold shape. Next, with the mold closed, a thermosetting resin is infused by vacuum into the particulate preform and after curing to form the desired product. In the exploratory study, epoxy and mineral particles including sand were chosen as material systems for feasibility demonstration. Thermal analysis and rheology were performed to assist in understanding of the fluid flow in heated porous media to achieve an optimized process window for rapid infusion. The results indicated that epoxy matrix composites with extremely high solid filler loading exceeding 70% by weight, as well as with complex external geometry, can be successfully produced. The resulting material is structurally uniform and its mechanical properties can be adjusted by changing the composition and makeup of the filler materials.
Fostering Ethical, Social, Environmental, Health, and Safety Awareness in Tomorrow’s Engineers and Technologists
Authors: Hanks J. Craig , Tate Jitendra , Fazarro Dominick , Trybula Walt , McLean Robert J. C. , Dutta Satyajit , Allhoff Fritz , Barton Seth , Russell Zach
Published: June 2016

This paper reports on our work developing a set of modular courses to intended to help foster Ethical, Social, Environmental, Health, and Safety Awareness in Tomorrow’s Engineers and Technologists. We focus on emerging technologies, and especially nanotechnology. In the last decade nanotechnology has made myriad inroads into mainstream society. It is merely one of many exciting new ways that science and technology are changing how we live and think. Along with these developments in science and technology come new industries, and new challenges. This requires heightened awareness of health and safety risks, ethical and social considerations, and environmental implications of their work. This need is not limited to nanotechnologies, nor revolutionary technologies, but should be an integral part of all engineering work.

Our NSF-funded project is developing and introducing introductory and advanced curricula for online and face-to-face course modules taught as full courses or infused into existing courses. The courses and modules are being developed and piloted with the guidance of an advisory council made up of nanotechnology leaders from academia and industry. One important goal of the project is to recruit, engage, prepare, and encourage students from traditionally underrepresented groups to careers in Science and Engineering, with a focus on Nanotechnology.

In this paper we explain the origin of the project and how we developed the course modules, review the first semesters teaching from these modules, and examine our initial results and evaluations.
Making Ethics Education Personal
Authors: Hoffman Allen H.
Published: June 2016

Accredited engineering programs are required to provide instruction in ethics. A primary goal of ethics education is to develop and improve a student’s ability to recognize situations involving ethical decisions and to encourage development of a personal framework by which to decide what to do. A major challenge in ethics education is to personalize situations that are typical of those that the students will likely encounter. This paper presents techniques that enable a faculty member to act as a facilitator in the discussion of ethics rather than as an instructor.
Effect of Boron Nitride Nanoparticles on the Mechanical Properties of Carbon Fiber Reinforced Polymeric Composites
Authors: Ghazizadeh Mahdi , Estevez Joseph E. , Kimbro Evan T. , Kelkar Ajit D.
Published: June 2016

The mechanical properties of three phase nano-modified carbon fiber reinforced polymeric composites (CFRP) fabricated using Heated Vacuum Assisted Resin Transfer Molding (HVARTM) is investigated. Eight layers of carbon fiber plain weave mats were stacked in quasi isotropic layup and Epoxy 862 resin (non–modified and modified with Boron Nitride Nanoparticles (BNNPs)) was used. For mechanical properties characterization, three ASTM tests were performed. These tests included Tension Test (ASTM D3039), Compression Test (ASTM D6641) and Flexural Bending Test (ASTM D7264). The behavior of control and nano-modified composite laminates were compared. Results indicated that even small percentage of Boron Nitride Nanoparticle can significantly affect mechanical behavior of CFRP as well as progressive failure mechanisms.
Magnetostrictive Self-Diagnosing Smart Bolts
Authors: Sevostianov Vladislav
Published: June 2016

The paper presents the concept of self-diagnosing smart bolts and its experimental validation. In the present research such bolts are designed, built, and experimentally tested. As a key element of the design, wires of Galfenol (alloy of iron and gallium) are used. This material shows magnetostrictive properties, and, at the same time, is sufficiently ductile to follow typical deformation of rock bolts, and is economically affordable. Two types of Galfenol were used: Ga10Fe90 and Ga17Fe83. The wires have been installed in bolts using two designs — in a drilled central hole or in a cut along the side — and the bolts were tested for generation of the magnetic field under three-point bending loading. To measure the magnetic field in the process of deformation, a magnetometer that utilizes the GMR effect was designed, built, and compared with one utilizing the Hall effect. It is shown that (1) magnetic field generated by deformation of the smart bolts at the stress level of plastic deformation is sufficient to be noticed by the proposed magnetometer; however, the magnetometer using Hall effect is insufficient; (2) Ga10Fe90 produces higher magnetic fields than Ga17Fe83; (3) the magnetic field in plastically bended bolts is relatively stable with time.
Recovery of Paper Fibers From TetraPak® Packaging: Material and Energetic Valorization of the Remaining Fraction
Authors: Castro Alexandra , Vilarinho Cândida , Araújo Jorge , Carvalho Joana
Published: June 2016

In this study, a methodology was developed for the treatment/valorization of all the constituent fractions of TetraPak ®, proposing pyrolysis technology for the recycling of plastic and aluminum fraction, resulting in the recovery process of the paper fibers. In percentage these three elements are distributed approximately as follows: 70% of cardboard (kraft paper), 25% of low-density polyethylene (LDPE) and 5% of aluminum foil [1, 2, 3, 4]. It was developed an integrated and innovative methodology that starts with the recovery of the paper fibers, which must reintegrate the production cycle of the packaging company. Followed by the valorization of the remaining fraction, this fraction consists in plastic and aluminum, and is valorized through a pyrolysis process. The pyrolysis process is an irreversible chemical modification of compounds by the action of heat and in the absence of oxygen. This technology are used for energy recovery, which causes thermal degradation of the compounds in anoxic environment, and is therefore considered an environmentally friendly technology and it is considered one of the alternative routes for treatment of waste TetraPak ® packaging [4]. The pyrolysis tests were carried out in laboratory reactor at different temperatures (between 300 and 500°C). At the end of this process the aluminum was recovered and it was produced a synthesis gas with added value. This produced gas was constituted by CO, H2, CO2 e CH4 with maximum values recorded of 5000, 3200 e 7.5 ppm e 40%, respectively. The laboratory test were confirmed by the analysis of the thermal behavior by DTA/TGA and it was confirmed that the temperature of 500°C is the most indicated for energetic valorization of the aluminum, paper and plastic fraction.
Magnetoelastic Analysis of Sandwich Cellular Cylinders
Authors: Akbarzadeh A. H. , Fu J. W. , Chen Z. T. , Pasini D.
Published: June 2016

This paper examines the time-harmonic eigenstrain behavior of a magnetoelastic sandwich cylinder with solid and cellular material layers. A sandwich panel subjected to an external magnetic field is assumed to endure an eigenstrain with a cubic polynomial radial distribution in the sandwich core. Using asymptotic homogenization, the effective material properties of the cellular material are determined as a function of relative density for various cell topologies, that are used in the cellular layers of a cylinder under given magnetic field. Bessel, Struve, and Lommel functions are used to obtain semi-analytic solutions for a sandwich cylinder with perfectly and imperfectly bonded interfaces. The results are first verified with those available in the literature of composite cylinders with solid material layers. Then the paper studies the role that cell topology, relative density, and bonding type at the layer interfaces play on the time-harmonic magnetoelastic responses. The numerical results reveal that the proper choice of relative density, cell topology, and cellular layer configuration can reduce the weight and stress regime, as well as improve the dynamic response of a sandwich cylinder subjected to a given magnetic field.
Design of New Multifunctional Galling-Corrosion Testing Apparatus
Authors: Azzi M. , Bitar-Nehme E. , Klemberg-Sapieha J. E.
Published: June 2016

Galling of materials is a severe surface damage characterized by macroscopic material removal when two solid surfaces experience relative sliding under high load. This mode of wear is of particular interest in applications where design constraints require assembly components to slide against each other without adequate lubrication. Examples are high-pressure ball valve with metal-to-metal seal contact, sheet metal forming process and medical/food processing instruments where lubrication is sometimes non-existent due contamination concerns. In addition to sliding at high load, materials in these applications can be exposed to aggressive environments which lead to combined tribological and corrosive degradation phenomena. Progress in this field depends largely on the understanding of the interaction between corrosion and wear processes. In this paper, we describe a new testing instrument capable of testing galling and sliding wear behavior under dry and wet conditions. Design of this instrument is guided by ASTM standards G98 for galling, G99 for pin-on-disk, G133 for ball-on-flat and G199 for tribocorrosion.

Galling configuration consists of two concentrically aligned hollow cylindrical specimen loaded along their longitudinal axis with constant load (max 5000 N). The upper specimen is held stationary while the lower specimen is rotated a number of cycles at a selected speed. During the test, the friction torque is measured using special torque/thrust load cell. For the combined galling/corrosion test, the specimen’s contact surface is submerged in an electrolytic solution and three-electrode type electrochemical cell is set-up using the specimens as working electrode. Galling/corrosion tests can be performed under open circuit potential or under controlled potentials. In the first type, the corrosion potential is monitored before, during and after rubbing, whereas in the second type, the corrosion potential and corrosion current are controlled before, during and after rubbing. In addition to galling, the instrument can also be used to conduct pin-on-disk and ball-on-flat tests under dry and wet conditions.
3D Stochastic Modeling of Columnar-to-Equiaxed Transition During the Solidification of Alloy 718
Authors: Nastac Laurentiu , Zhang Daojie
Published: June 2016

An efficient three-dimensional (3D) stochastic model for simulating the evolution of dendritic crystals during the solidification of alloys was developed. The model includes time-dependent computations for temperature distribution, solute redistribution in the liquid and solid phases, curvature, and growth anisotropy. The 3D model can run on PCs with reasonable amount of RAM and CPU time and therefore no parallel computations are needed. 3D mesoscopic computations at the dendrite tip length scale were performed in this study to simulate the formation of the columnar-to-equiaxed transition in alloy 718. Comparisons between microstructure predictions obtained via 2D and 3D stochastic modeling are also presented.
Application of Principles From the Scrum Agile Method to a Prototype Vehicle Control Development Cycle
Authors: Bonderczuk Derek , Currier Patrick , Nelson Matthew
Published: June 2016

Traditional methods for organization of controls development tend not to facilitate the speedy completion of complex tasks such as development of an experimental vehicle control system, particularly when staffing levels are low. This paper proposes the use of Scrum Agile software development methods to streamline the control development cycle for a prototype vehicle. The EcoCAR 2 competition vehicle at Embry-Riddle Aeronautical University is used as a case study for this implementation. Specific protocols and workflows for development are outlined and examples of implementation on the EcoCAR 2 vehicle are provided. Implementation results indicate that the method allowed for an aggressive development schedule for the vehicle software without compromising reliability, maintainability, or upgradeability.
Evaluation of Mechanical Properties at the Knit Line Interface in a Complex Multi-Cell PVC Extrusion
Authors: Grudzinski J. J. , Fischer R. , Talaga R. L. , Guarino V. , Pla-Dalmau A. , Fagan J. E. , Grozis C.
Published: June 2016

In order to form internal cells in PVC extrusions, the die requires an insert or internal member that the material flows past. These inserts are supported to the outer die structure by so-called spiders that pass through to the outer wall of the extrusion die. The extruded material must separate and then recombine as it passes over the spider. The material must then form a bond at this interface shortly before exiting the die. These interfaces are referred to as knit-lines. In a recent project involving a large and complex PVC extrusion, difficulty was encountered in developing these knit lines within the webs of the extrusions. Upon visual inspection, these interfaces appeared to be without bond over portions of the cross section. However, mechanical testing in the worst knits revealed that bonding had occurred with the knit providing 85% of the bulk material strength although without supporting any significant ductility. At the same time, knits at different parts of the extrusions showed ductility comparable with the base material. Altering the process variables showed a means for improvement in the webs but this was limited by other constraints. In this work we describe the character of the knitlines and the resulting mechanical properties along with the testing methodology.
A Decision Model for Selecting the Optimum Oil Production Profile Using Multi Criteria Decision Making and Social Choice Theory
Authors: Keivanpour Samira , Haleh Hassan , Ganjavi Hamed Shakouri
Published: June 2016

Applying a MCDM model has many benefits for decision makers in the course of oil field master development plans preparation and evaluation. In this study, a multi-criteria decision making model is proposed in order to achieve an optimum production profile. The most important criteria and parameters for selection of best production profile are identified. These parameters are derived by several interviews with Iranian oil Industry’s experts. The candidate alternatives for production profile are ranked using a combination of group decision making approach and social choice theory. The degree of group consensus is evaluated by using a statistic model to confirm the validity of decision making model.
Influence of ZnSe capping of CdSe layers in the growth mode of ZnCdMgSe/CdSe/ZnCdMgSe heterostructures
Authors: Alfaro-Martínez Adrián Darío , Hernández-Calderón Isaac , Tamargo Maria C.
Published: June 2016

The authors present a photoluminescence study of the optical and structural properties of ZnSe/CdSe/ZnSe layers grown by atomic layer epitaxy, embedded within barriers of ZnCdMgSe lattice-matched to the InP (001) substrate. The authors show that a few ZnSe monolayers surrounding the CdSe layer inhibit quantum dot formation and induce the growth of quantum islands of CdSe. For the case of a 2 monolayers coverage of CdSe, quantum islands of 1 and 2 monolayers thickness were observed. These quantum islands (or quantum terraces) present intense luminescence even at room temperature.
Body Composition, Neuromuscular Performance, and Mobility: Comparison Between Regularly Exercising and Inactive Older Women
Authors: Rava Anni , Pihlak Anu , Ereline Jaan , Gapeyeva Helena , Kums Tatjana , Purge Priit , Jürimäe Jaak , Pääsuke Mati
Published: June 2016

The purpose of this study was to evaluate the differences in body composition, neuromuscular performance, and mobility in healthy, regularly exercising and inactive older women, and examine the relationship between skeletal muscle indices and mobility. Overall, 32 healthy older women participated. They were divided into groups according to their physical activity history as regularly exercising (n = 22) and inactive (n = 10) women. Body composition, hand grip strength, leg extensor muscle strength, rapid force development, power output, and mobility indices were assessed. Regularly exercising women had lower fat mass and higher values for leg extensor muscle strength and muscle quality, and also for mobility. Leg extensor muscle strength and power output during vertical jumping and appendicular lean mass per unit of body mass were associated with mobility in healthy older women. It was concluded that long-term regular exercising may have beneficial effects on body composition and physical function in older women.
TNF-insulin crosstalk at the transcription factor GATA6 is revealed by a model that links signaling and transcriptomic data tensors
Authors: Chitforoushzadeh Zeinab , Ye Zi , Sheng Ziran , LaRue Silvia , Fry Rebecca C. , Lauffenburger Douglas A. , Janes Kevin A.
Published: June 2016

Data-driven modeling identifies a mechanism for insulin to suppress proinflammatory signals.
Sestrin regulation of TORC1: Is Sestrin a leucine sensor?
Authors: Lee Jun Hee , Cho Uhn-Soo , Karin Michael
Published: June 2016

Sestrin2 may not be a leucine sensor for mTORC1.
Augmented noncanonical BMP type II receptor signaling mediates the synaptic abnormality of fragile X syndrome
Authors: Kashima Risa , Roy Sougata , Ascano Manuel , Martinez-Cerdeno Veronica , Ariza-Torres Jeanelle , Kim Sunghwan , Louie Justin , Lu Yao , Leyton Patricio , Bloch Kenneth D. , Kornberg Thomas B. , Hagerman Paul J. , Hagerman Randi , Lagna Giorgio , Hata Akiko
Published: June 2016

Blocking a BMP signaling pathway may ameliorate neurological defects in patients with fragile X syndrome.
BMP signaling turns up in fragile X syndrome: FMRP represses BMPR2
Authors: Broihier Heather T.
Published: June 2016

Reducing bone morphogenetic protein (BMP) signaling may reverse neuroanatomical defects in fragile X syndrome.
LXR maintains cholesterol balance through a noncoding RNA
Authors: VanHook Annalisa M.
Published: June 2016

A noncoding RNA induced by the liver X receptor binds the transcriptional cofactor RALY and inhibits the expression of genes involved in cholesterol biosynthesis.
New connections: Making discoveries in complex data sets
Authors: Gough Nancy R.
Published: June 2016

Computational approaches reveal signaling mechanisms hidden in complex data sets.
Micromanaging puberty
Authors: Ferrarelli Leslie K.
Published: June 2016

An intricate microRNA-regulated network controls the onset of puberty in mice.
Horizontal Transfer of Carbapenemase-Encoding Plasmids and Comparison with Hospital Epidemiology Data
Authors: Hardiman C. A. , Weingarten R. A. , Conlan S. , Khil P. , Dekker J. P. , Mathers A. J. , Sheppard A. E. , Segre J. A. , Frank K. M.
Published: June 2016

Carbapenemase-producing organisms have spread worldwide, and infections with these bacteria cause significant morbidity. Horizontal transfer of plasmids carrying genes that encode carbapenemases plays an important role in the spread of multidrug-resistant Gram-negative bacteria. Here we investigate parameters regulating conjugation using an
Escherichia coli
laboratory strain that lacks plasmids or restriction enzyme modification systems as a recipient and also using patient isolates as donors and recipients. Because conjugation is tightly regulated, we performed a systematic analysis of the transfer of
Klebsiella pneumoniae
carbapenemase (
bla
KPC
)-encoding plasmids into multiple strains under different environmental conditions to investigate critical variables. We used four
bla
KPC
-carrying plasmids isolated from patient strains obtained from two hospitals: pKpQIL and pKPC-47e from the National Institutes of Health, and pKPC_UVA01 and pKPC_UVA02 from the University of Virginia. Plasmid transfer frequency differed substantially between different donor and recipient pairs, and the frequency was influenced by plasmid content, temperature, and substrate, in addition to donor and recipient strain. pKPC-47e was attenuated in conjugation efficiency across all conditions tested. Despite its presence in multiple clinical species, pKPC_UVA01 had lower conjugation efficiencies than pKpQIL into recipient strains. The conjugation frequency of these plasmids into
K. pneumoniae
and
E. coli
patient isolates ranged widely without a clear correlation with clinical epidemiological data. Our results highlight the importance of each variable examined in these controlled experiments. The
in vitro
models did not reliably predict plasmid mobilization observed in a patient population, indicating that further studies are needed to understand the most important variables affecting horizontal transfer
in vivo
.
Inhibition of LpxC Increases Antibiotic Susceptibility in Acinetobacter baumannii
Authors: García-Quintanilla Meritxell , Caro-Vega José M. , Pulido Marina R. , Moreno-Martínez Patricia , Pachón Jerónimo , McConnell Michael J.
Published: June 2016

LpxC inhibitors have generally shown poor
in vitro
activity against
Acinetobacter baumannii
. We show that the LpxC inhibitor PF-5081090 inhibits lipid A biosynthesis, as determined by silver staining and measurements of endotoxin levels, and significantly increases cell permeability. The presence of PF-5081090 at 32 mg/liter increased susceptibility to rifampin, vancomycin, azithromycin, imipenem, and amikacin but had no effect on susceptibility to ciprofloxacin and tigecycline. Potentiating existing antibiotics with LpxC inhibitors may represent an alternative treatment strategy for multidrug-resistant
A. baumannii
.
Pyrazinamide Is Active against Mycobacterium tuberculosis Cultures at Neutral pH and Low Temperature
Authors: den Hertog Alice L. , Menting Sandra , Pfeltz Richard , Warns Matthew , Siddiqi Salman H. , Anthony Richard M.
Published: June 2016

For the past decades, an acidic pH has been used to render
Mycobacterium tuberculosis
susceptible to pyrazinamide for
in vitro
testing. Here, we show that at the standard breakpoint concentration and reduced culture temperatures, pyrazinamide (PZA) is active against tuberculosis (TB) at neutral pH. This finding should help unravel the mechanism of action of PZA and allow drug susceptibility testing (DST) methods to be optimized.
Differences in the Molecular Epidemiology and Antibiotic Susceptibility of Clostridium difficile Isolates in Pediatric and Adult Patients
Authors: Kociolek Larry K. , Gerding Dale N. , Osmolski James R. , Patel Sameer J. , Snydman David R. , McDermott Laura A. , Hecht David W.
Published: June 2016

The rising incidence of
Clostridium difficile
infections (CDIs) in adults is partly related to the global spread of fluoroquinolone-resistant strains, namely, BI/NAP1/027. Although CDIs are also increasingly diagnosed in children, BI/NAP1/027 is relatively uncommon in children. Little is known about the antibiotic susceptibility of pediatric CDI isolates.
C. difficile
was cultured from
tcdB
-positive stools collected from children diagnosed with CDI between December 2012 and December 2013 at an academic children's hospital. CDI isolates were grouped by restriction endonuclease analysis (REA). MICs were measured by agar dilution method for 7 antibiotics. Susceptibility breakpoints were based on guidelines from CLSI and/or the European Committee on Antimicrobial Susceptibility Testing (EUCAST). MICs and REA groupings of
C. difficile
isolates from 74 adult patients (29 isolates underwent REA) from a temporally and geographically similar adult cohort were compared to those of pediatric isolates. Among 122 pediatric and 74 adult isolates, respectively, the rates of resistance were as follows: metronidazole, 0% and 0%; vancomycin, 0% and 8% (
P
= 0.003); rifaximin, 1.6% and 6.7% (
P
= 0.11); clindamycin, 18.9% and 25.3% (
P
= 0.29); and moxifloxacin, 2.5% and 36% (
P
= <0.0001). Only 1 of 122 (0.8%) BI/NAP1/027 isolates was identified among the children, compared to 9 of 29 (31%) isolates identified among the adults (
P
= <0.0001). The 3 moxifloxacin-resistant pediatric isolates were of REA groups BI and CF and a nonspecific group. The 2 rifaximin-resistant pediatric isolates were of REA groups DH and Y. The 21 clindamycin-resistant pediatric isolates were distributed among 9 REA groups (groups A, CF, DH, G, L, M, and Y and 2 unique nonspecific REA groups). These data suggest that a diverse array of relatively antibiotic-susceptible
C. difficile
strains predominate in a cohort of children with CDI compared to adults.
Validation and Application of a Dried Blood Spot Assay for Biofilm-Active Antibiotics Commonly Used for Treatment of Prosthetic Implant Infections
Authors: Knippenberg Ben , Page-Sharp Madhu , Salman Sam , Clark Ben , Dyer John , Batty Kevin T. , Davis Timothy M. E. , Manning Laurens
Published: June 2016

Dried blood spot (DBS) antibiotic assays can facilitate pharmacokinetic (PK)/pharmacodynamic (PD) studies in situations where venous blood sampling is logistically difficult. We sought to develop, validate, and apply a DBS assay for rifampin (RIF), fusidic acid (FUS), and ciprofloxacin (CIP). These antibiotics are considered active against organisms in biofilms and are therefore commonly used for the treatment of infections associated with prosthetic implants. A liquid chromatography-mass spectroscopy DBS assay was developed and validated, including red cell partitioning and thermal stability for each drug and the rifampin metabolite desacetyl rifampin (Des-RIF). Plasma and DBS concentrations in 10 healthy adults were compared, and the concentration-time profiles were incorporated into population PK models. The limits of quantification for RIF, Des-RIF, CIP, and FUS in DBS were 15 μg/liter, 14 μg/liter, 25 μg/liter, and 153 μg/liter, respectively. Adjusting for hematocrit, red cell partitioning, and relative recovery, DBS-predicted plasma concentrations were comparable to measured plasma concentrations for each antibiotic (
r
> 0.95;
P
< 0.0001), and Bland-Altman plots showed no significant bias. The final population PK estimates of clearance, volume of distribution, and time above threshold MICs for measured and DBS-predicted plasma concentrations were comparable. These drugs were stable in DBSs for at least 10 days at room temperature and 1 month at 4°C. The present DBS antibiotic assays are robust and can be used as surrogates for plasma concentrations to provide valid PK and PK/PD data in a variety of clinical situations, including therapeutic drug monitoring or studies of implant infections.