bluuebunny/crossref_metadata_2025 huggingface dataset:
Religious Environmentalism and Environmental Religion in America
Authors: Berry Evan
Published: October 2013

This essay aims to offer a rudimentary map of the subfield of religion and ecology by describing three distinct scholarly responses to the challenge leveled by Lynn White's influential 1967 article. It articulates an organizational view of the field by accounting for the three most prevalent perspectives on the antagonism between religion and environmentalism. The first, ecotheological apologism, looks to resuscitate “Judeo‐Christian” theology from the critique that it is inherently anti‐ecological. The second, sociological operationalization, forgoes normative engagement in favor of descriptive measurement, seeking to describe in empirical terms the environmental beliefs and behaviors of religious individuals in contemporary society. The third, theoretical functionalism, works to soften the very distinction between religious tradition and ecological morality. Examining the sources and outcomes of these scholarly divergences provides a reasonable account of the development of religion and ecology as an area of study and brings to the fore the challenges presently facing the subfield. In conclusion, the essay describes the exchanges among these scholarly threads and suggests how they might be woven together more closely.
Christianity and Food: Recent Scholarly Trends
Authors: Patterson Barbara A. B. , Banks Shirley M.
Published: October 2013

Today's scholarship on Christianity's relationships with, to, and through foods, performatively, theologically, and ethically, must address global constituents and claims. Recent scholarship on Christianity and food moves from the usual markets of textual research, socio‐cultural histories, and ethnography to more interdisciplinary approaches stirred by global Christian communities and concerns. This article highlights shifts in more traditional, field‐related scholarship about Christianity and food while demonstrating why global Christian perspectives not only build from that research but also push beyond it. The field‐related scholarship is reviewed using four frames or categories, offered as organizing and heuristic help. They are the following: socio‐cultural and comparative; lived religion and ethnography; feminist, womanist, and liberatory; and global. Two types of material broadly inform these frames: historical and textual, and ethnographic and lived or practiced religion. The current and future diversity, needs, and claims of global Christian communities and contexts cannot be contained or wedged into scholarship traditionally bound to these field‐situated approaches. Scholarship related to Christianity, and food must embrace interdisciplinary and innovative strategies shared among world‐wide scholars and practitioners. From questions about community identity, to celebratory feasting and observant fasting during, cultural and seasonal cycles, including Eucharist and earth care, the future of research in global Christianity and food promises a feast of possibilities. Scholars will find a rich range of challenging issues involving faith and practice tuned to global viewpoint on ritual and performance, theologies, colonial resistances, and global alliances and politics.
Swami Vivekananda (1863–1902) 150 Years on: Critical Studies of an Influential Hindu Guru
Authors: Beckerlegge Gwilym
Published: October 2013

Swami Vivekananda has been recognised as one of the most influential but arguably controversial Hindu gurus of the last two centuries. In this year of the 150th anniversary of Vivekananda's birth, this article will examine the concerns and approaches that have come increasingly to characterise etic scholarship concerning Vivekananda's life and legacy. Referring as a starting point to an earlier historiographical review completed in the early 1990s, the article then explores how scholarly studies have revisited the question of the nature of Vivekananda's influence on Hindu nationalism (Hindutva) and have come to give greater prominence to his role in the globalisation of yoga.
Income Shares Revisited
Authors: Izyumov Alexei , Vahaly John
Published: October 2013

A number of recent studies claim that when properly computed, factor income shares across countries at different levels of development are essentially uniform. This note evaluates the methodology behind such findings and offers estimates using newly available data. The results for a group of 55 developed, developing, and transition economies for the period 1990–2008 lead us to reject the hypothesis of factor share convergence.
The meaning of ethically charged encounters and their possible influence on professional identity in Norwegian public health nursing: a phenomenological hermeneutic study
Authors: Dahl Berit Misund , Clancy Anne , Andrews Therese
Published: October 2013

Background

In today's health care, new health reforms focus on market values and demands of efficiency influence health workers' professional practice. Norwegian public health nurses work mainly with healthy populations, but the children, families and young people they meet can be in vulnerable and even dependent situations. Strategies in coping with ethically challenging encounters can be important for the identity of the profession.

Aim

The aim of the study was to illuminate public health nurses' experiences of being in ethically charged encounters and to reflect upon how these experiences can influence their professional identity.

Method

A purposive sample of 23 Norwegian public health nurses with experience ranging from 0.5 to 25 years narrated about their work‐related experiences. The interviews were interpreted with a phenomenological hermeneutic method inspired by the philosophy of Paul Ricoeur.

Findings

Four themes were identified: feeling responsible, being committed, feeling confident and feeling inadequate. These experiences were related to both work and private life and involved an emotional commitment to the well‐being of children, young people and families.

Conclusion

On the basis of the findings, it can be estimated thatPHNs are committed to their work, and defending children's rights is a strong driving force. Responsibility for service users is a deciding factor that can overshadow institutional demands. It seems as if value conflicts mobilised courage which is essential in maintaining moral strength. This is in turn important for a strong professional identity and can have positive implications for the quality of public health nursing work.
Rye Pm8 and wheat Pm3 are orthologous genes and show evolutionary conservation of resistance function against powdery mildew
Authors: Hurni Severine , Brunner Susanne , Buchmann Gabriele , Herren Gerhard , Jordan Tina , Krukowski Patricia , Wicker Thomas , Yahiaoui Nabila , Mago Rohit , Keller Beat
Published: October 2013

The improvement of wheat through breeding has relied strongly on the use of genetic material from related wild and domesticated grass species. The 1RS chromosome arm from rye was introgressed into wheat and crossed into many wheat lines, as it improves yield and fungal disease resistance. Pm8 is a powdery mildew resistance gene on 1RS which, after widespread agricultural cultivation, is now widely overcome by adapted mildew races. Here we show by homology‐based cloning and subsequent physical and genetic mapping that Pm8 is the rye orthologue of the Pm3 allelic series of mildew resistance genes in wheat. The cloned gene was functionally validated as Pm8 by transient, single‐cell expression analysis and stable transformation. Sequence analysis revealed a complex mosaic of ancient haplotypes among Pm3‐ and Pm8‐like genes from different members of the Triticeae. These results show that the two genes have evolved independently after the divergence of the species 7.5 million years ago and kept their function in mildew resistance. During this long time span the co‐evolving pathogens have not overcome these genes, which is in strong contrast to the breakdown of Pm8 resistance since its introduction into commercial wheat 70 years ago. Sequence comparison revealed that evolutionary pressure acted on the same subdomains and sequence features of the two orthologous genes. This suggests that they recognize directly or indirectly the same pathogen effectors that have been conserved in the powdery mildews of wheat and rye.
Braid group actions via categorified Heisenberg complexes
Authors: Cautis Sabin , Licata Anthony , Sussan Joshua
Published: October 2013

We construct categorical braid group actions from 2-representations of a Heisenberg algebra. These actions are induced by certain complexes which generalize spherical (Seidel–Thomas) twists and are reminiscent of the Rickard complexes defined by Chuang–Rouquier. Conjecturally, one can relate our complexes to Rickard complexes using categorical vertex operators.
The Chabauty–Coleman bound at a prime of bad reduction and Clifford bounds for geometric rank functions
Authors: Katz Eric , Zureick-Brown David
Published: October 2013

Let $X$ be a curve over a number field $K$ with genus $g\geq 2$, $\mathfrak{p}$ a prime of ${ \mathcal{O} }_{K} $ over an unramified rational prime $p\gt 2r$, $J$ the Jacobian of $X$, $r= \mathrm{rank} \hspace{0.167em} J(K)$, and $\mathscr{X}$ a regular proper model of $X$ at $\mathfrak{p}$. Suppose $r\lt g$. We prove that $\# X(K)\leq \# \mathscr{X}({ \mathbb{F} }_{\mathfrak{p}} )+ 2r$, extending the refined version of the Chabauty–Coleman bound to the case of bad reduction. The new technical insight is to isolate variants of the classical rank of a divisor on a curve which are better suited for singular curves and which satisfy Clifford’s theorem.
Characterization of a Computational Fluid Dynamics Thermocouple Model Subjected to Stochastic Environmental Forcing Using Moment Based Analysis
Authors: Weinschenk Craig G. , Ezekoye O. A.
Published: October 2013

With increasing requirements for model validation when comparing computational and experimental results, there is a need to incorporate detailed representations of measurement devices within the computational simulations. Thermocouples are the most common temperature measurement transducers in flames and fire environments. Even for the relatively simple thermocouple transducer, the coupling of heat transfer mechanisms particularly under unsteady flow conditions leads to interesting dynamics. As experimentalists are well aware, the experimentally determined thermocouple values are not the same as the local gas temperatures and corrections are often required. From the computational perspective, it is improper then to assume that the predicted gas temperatures should be the same as the temperatures that an experimentalist might measure since the thermal characteristics of the thermocouple influence the indicated temperature. The thermal characteristics of simulated thermocouples in unsteady flame conditions are investigated. Validation exercises are presented to test the underlying thermocouple model. The thermocouple model problem is examined for a quasi-steady problem in which the gas temperature and surrounding walls are assumed to be random and described by probability density functions (PDFs). Differences are noted between the predicted thermocouple response and expected response. These differences are interpreted from the perspective of what modeling artifacts might drive the differences.
Improvement of Forced Convection Cooling Due to the Attachment of Heat Sources to a Conducting Thick Plate
Authors: Reza Hajmohammadi Mohammad , Campo Antonio , Nourazar S. Salman , Masood Ostad Amir
Published: October 2013

It is proposed that a conductive thick plate is placed between a heat source and a cold flowing fluid to improve the forced convection cooling performance. Detailed numerical work is carried out to determine the optimal thickness of the conductive thick plate which minimizes the peak temperature. It is shown that the thick plate significantly reduces the excess temperature of heat sources, by way of conducting the heat current in an optimal manner. It is shown that the reduction in the excess temperature of heat sources depends upon the Reynolds number of the fluid flow and the material thermal conductivity. Correlations for the optimum plate thickness and reduction in excess temperature of heat sources are presented, which could be useful for the practitioners.
Force Controlled Manipulation of Biological Cells Using a Monolithic MEMS Based Nano-Micro Gripper
Authors: Abbasi Ali A. , Ahmadian M. T.
Published: October 2013

Nano-micro grippers are able to pick-transport-place the micro or nanometer–sized materials, such as manipulation of biological cells or DNA molecules in a liquid medium. This paper proposes a novel monolithic nano-micro gripper structure with two axis piezoresistive force sensor which its resolution is under nanoNewton. The results of the study have been obtained by the simulation of the proposed gripper structure in Matlab software. Motion of the gripper arm is produced by a voice coil actuator. The behavior of the cell has been derived using the assumptions in the literatures. Moreover, two simple PID controllers, one for control of the gripper motion and another for control of the force during manipulation of a biologic cell, have been implemented. Although the proposed gripper has not been fabricated, since the geometrical dimensions of the proposed gripper is the same as previously developed electrothermally actuated micro-nano gripper, the results of force control have been also compared with it. The simulated results with the very simple PID force controller which has a more rapid response than previously developed electrothermally actuated micro-nano gripper show that the designed gripper has the potential to be considered and fabricated for manipulation of biological cells in the future.
Utilization of Least Square Support Vector Machine (LSSVM) for Electrical Resistivity Prediction of the Zn-Mn-S Nanocrystalline Semiconductor Films
Authors: Abbasi Ali A. , Ahmadian M. T.
Published: October 2013

In this investigation, application of the least square support vector machine (LSSVM) for modeling of the electrical resistivity of the magnetic Zn-Mn-S nanocrystalline semiconductor films has been described. The model has been trained based on the experimental data obtained from a published work by Sreekantha Reddy et al. The model inputs are temperature and variations in the concentrations of Zn, Mn. The results indicate that LSSVM is able to be used for accurate prediction of the electrical resistivity of the Zn-Mn-S nanocrystalline semiconductor films.
New Type of Transmission Screw Nuts With Structure of Steel-Backing/Self-Lubrication Composite Lining
Authors: Sun Yousong , Zhou Xianhui , Cheng Yongqi , Wei Liangmo , Li Chunmei
Published: October 2013

Transmission screw nuts with structure of steel-backing/self-lubrication composite lining have the advantages of high bearing capacity and low friction coefficient. Two materials and fabricating methods of linings were developed for the new screw nuts. Lubrication grooves on the female thread surfaces of the nuts were made during fabricating. One material was based on Carbon-Fabric/Epoxy (CFR/EP) and the lining was fabricated by pasting. The other was based on Carbon-Fiber/Epoxy (CF/EP) and the lining was fabricated by injecting. Experiments showed that in comparison with bronze nuts, the friction coefficients of CFR/EP and CF/EP nuts were reduced by 54% and 36% respectively, and the transmission efficiency increased by 50% and 29% respectively. The bearing capacities of the composite nuts were also increased. Differing from all metal-metal screws, the static frictions of the new screws were lower than the dynamic. It would have great effects on screw dynamic characteristics and need further researches.
Numerical Simulation and Experimental Research on Wrinkle Defect During Hot Bar Rolling Process
Authors: Chen Lin , Xu Chun
Published: October 2013

In the paper, surface wrinkle defect occurring during hot bar rolling process is studied with the combination of FEM simulation method and experimental method. The effect of entry width and the fillet radii of billet on displacement velocity and profile on billet corner is simulating analyzed. The calculated results have the same regularity as the experiment with continuous casting billet. It is found that the shallow crack or deeply fissures on the surface of workpiece are observed with the increase of the entry width and decrease of fillet radii of billet. All of crack regions are ditches with different sizes on the surface in optical microscope. At the same time, the flowing velocity of metal on billet corner is quite different from FEM simulation, some have so negative movement that resulting in ditches in the profile. Simulated results had the same tendency of formation of crack as the experimental results. Either result reveals that the main reason inducing surface wrinkle defect to occur during hot bar rolling process is the opposite flowing velocity of metal on billet corner.
A Concentrator of E. coli in Water Flow
Authors: Mayeed Mohammed S. , Newaz Golam M.
Published: October 2013

The objective of this research is to design and optimize a mini/micro-channel based concentrator of E. coli and integrate it with an acoustic wave biosensor. A computational research has been carried out using the state of the art computational software, CFD-ACE with water as bacteria bearing fluid. E. coli bacteria have been modeled as random discrete particles tracked by solving the Lagrangian equations. The design challenges are to achieve high particle to water ratio, high enough Reynolds number to avoid bacteria swimming, and various particle boundary conditions. The optimized design has achieved concentration of more than an order of magnitude higher than the inlet concentration at a flow velocity much higher than the bacteria swimming speed under various particle-boundary interactions. Bypass channels have been used to separate concentrated water-particle mixture and to put this mixture directly onto the biosensor’s bacteria detecting surface for safe and precise installation of the biosensor in the fluidic chip.
Biomechanics of Regular and Lateral Stair Climbing
Authors: Almashqbeh S. F.
Published: October 2013

The kinematic and kinetic differences between two styles of stair climbing, namely regular stair climbing (RSC) and lateral stair climbing (LSC), was studied. A four-step wooden stair instrumented with two force plates was used as the action platform. The kinematic and kinetic recordings were collected using a 6-camera, 2-force plate commercial three-dimensional motion analysis system. The LSC activity was subdivided into LSCL activity, where the right leg was the leading leg, and LSCT.
A Novel Look at the Performance of the Cyclorotor Propulsion System for Air Vehicles
Authors: Páscoa José C. , Dumas Antonio , Trancossi Michele
Published: October 2013

A system in which a rotating-wing device, comprising several pitching blades, turns around an axis along the span of the blades is called a cyclorotor. During the azimuthal rotation of the blades they also experience a change in the pitch angle. For each of the blades its pitch is varied cyclically by mechanical means such that the blades experience positive angles of attack at both the top and bottom positions of the azimuth cycle. The resultant unsteady motion of each blade can then be summed up into a resultant lift and drag forces. An almost instantaneous variation of magnitude and direction of the total cyclo rotor thrust can be obtained by changing the amplitude and phase of the cyclic blade pitch. In this rotor, conversely to classical propellers, each spanwise blade element operates at similar flow velocities, Reynolds numbers and incidence, this allows an easier blade optimization to achieve the best aerodynamic efficiency. Further, the cyclorotor is based on using dynamic pitching in order to delay stall and in this way increase the lift produced by the blades. Realistic flying vehicles have only be presented for the MAV-scale, its use on large scale vehicles turns problematic, herein we will analyze its stopovers. Finally, a very advantageous characteristic is the possibility to achieve almost instantaneous thrust variation in any direction perpendicular to the rotational axis, this will result in an air vehicle with a much better maneuverability, as compared with vehicles powered by classical rotor systems. This comes at a cost of a larger structure which might lead to a weight penalty.
A Fluid-Structure Interaction Model of Atherosclerosis at Abdominal Aorta
Authors: Al-Rawi M. A. , Al-Jumaily A. M. , Lu J. , Lowe A.
Published: October 2013

Atherosclerosis is a form of cardiovascular disease that is a major contributing factor to death and disability worldwide. This study uses computational fluid dynamics (CFD) models as a cost effective and non-invasive method to determine the location and condition of atherosclerosis segments on the arterial wall. It also investigates changes in the abdominal aorta geometry including the inner and outer diameters, the length of the disease segments and the thickness of the arterial wall on the development of disease. Three groups of unhealthy conditions are assumed with each group having eight cases, which are compared to the control case of healthy condition. An invasive catheter pulsatile blood flow is imposed at the ascending aorta and pressure waveforms data is imposed at the four outlets of the aorta and also used to validate the present models. The results show that the stress phase angle at the brachial artery could be correlated to the early stages of atherosclerosis development at the abdominal aorta. This can be detected by measured values of the systolic wall shear stress and elastic strain intensity which increases due to the forward pulse wave resulting from atherosclerosis, while the diastolic values of stresses decreases due to the delay of the backward waves which reach the brachial artery. The three scenarios of atherosclerosis show that the forward and backward waves, which can be attributed to changes in the diameter, length and thickness of the abdominal aorta, can be non-invasively used to diagnose cardiovascular diseases.
Development of Grinding Robot System for Engine Cylinder Liner’s Oil Groove
Authors: Jeon D. J. , Noh T. Y. , Jung C. W. , Lee Y. S. , Oh Y. C.
Published: October 2013

An engine for marine propulsion and power generation consists of several cylinder liner-piston sets. And the oil groove is on the cylinder liner inside wall for the lubrication between piston and cylinder. The grinding processes of oil groove have been carried by manual work so far, because of the diversity of the shape. Recently, we developed an automatic grinding robot system for oil groove grinding of engine cylinder liners. It can cover various types of oil grooves and adjust its position by itself. The grinding robot system consists of a robot, a grinding tool head, sensors, a control system and setting equipment. The robot automatically recognizes the cylinder liner’s inside configuration by using a laser distance sensor and a vision sensor after the cylinder liner is placed on setting equipment. And grinding programs are generated on the basis of measured data. The grinding system of oil groove incorporating an industrial robot was successfully developed and can cover various cylinder types efficiently in this field. The developed system helps to increase productivity of cylinder liner and remove difficult works.
Fabrication and Characterization of Starch Based Bagasse Fiber Composite
Authors: Mehanny Sherif , Farag Mahmoud , Rashad R. M. , Elsayed Hamdy
Published: October 2013

Environmentally-friendly, biodegradable, “green” composites were fabricated from starch-based matrix and bagasse (sugar cane waste) fibers. Native corn starch was mixed with glycerin and water, emulsified then added to the bagasse fibers previously prepared and treated by NaOH. The composite was preheated, then pressed for 30 minutes at 5 MPa and 170°C. SEM showed good adhesion between fibers and matrix up to 60wt% fibers. Density measurements showed low porosity for all composite samples up to 60wt% fibers. Both the tensile and flexural strengths increased as the fiber weight fraction increased from 0% to 60%. Water Uptake and thermal degradability tests showed higher stability for composite with increasing fiber content. The results show that the 60wt% bagasse fiber starch-based composite is an eco-friendly and inexpensive candidate for many applications.
Comprehensive Engineering: A New Concurrent Engineering to Reduce Cost and Increase Productivity Across Industries
Authors: Fukuda Shuichi
Published: October 2013

Concurrent Engineering (CE) realized faster time to market with great reduction of time, cost and energy. This old version of CE, however, focused its attention to production within an individual industry. It is process-focused.

It is pointed out that if we expand CE from individual industry to a group of industries, greater increase of productivity and reduction of cost can be achieved.

In this new version of industry-focused CE, overlaps will be eliminated and common functions across industries are pursued.

Such seamless engineering will bring us a great reduction of energy consumption and it will contribute a great deal toward the establishment of the green society.
Aerodynamic Instability Modes for a Load Slung From a Helicopter
Authors: Sharma Sumant , Komerath Narayanan , Smith Marilyn , Raghav Vrishank
Published: October 2013

The aerodynamic-dynamic interaction of a load slung from a helicopter in flight can lead to divergent oscillations. In this paper, interactions between degrees of freedom are explored through fundamental simulation and wind tunnel experiments of generic shapes. Video analysis of the behavior of loads in a wind tunnel provides insights into dynamic behavior, and reveals the difference in behavior of the same model between wind tunnels of different sizes. A compound pendulum motion in a plane orthogonal to a steady freestream is first studied. Even with proximate walls, a purely symmetric single degree of freedom oscillation does not amplify. The addition of an out-of-phase force as a simplified model for yaw effects, leads to amplification or damping under some conditions. Wall effects amplify this interaction further. This level of simulation enables guidance to develop metrics for unsteady wall interference in dynamic testing. Results to-date set the context for future work in refining the aerodynamic and dynamic models, including tether and vehicle dynamics. Incorporation of quasi-steady and unsteady loads data from wind tunnel measurements and computational fluid dynamics would enable prediction of the linear superposition stage leading towards divergence. Comparison of simulaiton results to measured parameters from wind tunnel experiments shows relative agreement.
Numerical Simulation of Nanopulse Penetration of Biological Matters Using the ADI-FDTD Method
Authors: Zhu Fei , Dai Weizhong
Published: October 2013

Study of the nanopulse bioeffects is important to ensure the appropriate application with nanopulse in biomedical and biotechnological settings. In this article, we develop an alternating-direction implicit (ADI) finite-difference time-domain (FDTD) scheme coupled with the Cole-Cole expression for dielectric coefficients of biological tissues to simulate the electromagnetic fields inside the biological tissues when exposed to nanopulses. The scheme is then tested by numerical examples with two different biological tissues. Numerical results show that the proposed ADI-FDTD scheme breaks through the Courant, Friedrichs, and Lewy (CFL) stability condition and provides a stable solution with a larger time step, where the conventional FDTD scheme fails. Results also indicate that the computational time can be reduced when using a larger time step.
Finite Element Analysis of a Frictionally Damped Slender Endmill
Authors: Madoliat Reza , Hayati Sajad
Published: October 2013

This paper primarily deals with suppression of chatter in end-milling process. Improving the damping is one way to achieve higher stability for machining process. For this purpose a damper is proposed that is composed of a core and a multi fingered hollow cylinder which are shrink fitted in each other and their combination is shrink fitted inside an axial hole along the tool axis. This structure causes a resisting friction stress during bending vibration. Using FEA-ANSYS the structure is simulated. Then a parameter study is carried out where the frequency response and the depth of cut are calculated and tabulated to obtain the most effective configuration. The optimal configuration of tool is fabricated and finite element results are validated using modal test. The results show a high improvement in performance of the tool with proposed damper. Good agreement between experiments and modeling is obtained.
Functionally Heterogeneous Porous Scaffold Design for Tissue Engineering
Authors: Khoda A. K. M. B. , Koc Bahattin
Published: October 2013

Most of the current tissue scaffolds are mainly designed with homogeneous porosity which does not represent the spatial heterogeneity found in actual tissues. Therefore engineering a realistic tissue scaffolds with properly graded properties to facilitate the mimicry of the complex elegance of native tissues are critical for the successful tissue regeneration. In this work, novel bio-mimetic heterogeneous porous scaffolds have been modeled. First, the geometry of the scaffold is extracted along with its internal regional heterogeneity. Then the model has been discretized with planner slices suitable for layer based fabrication. An optimum filament deposition angle has been determined for each slice based on the contour geometry and the internal heterogeneity. The internal region has been discritized considering the homogeneity factor along the deposition direction. Finally, an area weight based approach has been used to generate the spatial porosity function that determines the filament deposition location for desired bio-mimetic porosity. The proposed methodology has been implemented and illustrative examples are provided. The effective porosity has been compared between the proposed design and the conventional homogeneous scaffolds. The result shows a significant error reduction towards achieving the bio-mimetic porosity in the scaffold design and provides better control over the desired porosity level. Moreover, sample designed structures have also been fabricated with a NC motion controlled micro-nozzle biomaterial deposition system.
Residual Stress Evaluation in Machined Surfaces of Copper by Molecular Dynamic Simulation
Authors: Wang Yachao , Ji Chunhui , Shi Jing , Liu Zhanqiang
Published: October 2013

Residual stresses in machined surfaces are often regarded as a determining factor of component service life. However, little work has been conducted to investigate the distribution of residual stresses in machined surfaces at nano-scale. In this paper, an MD simulation study is performed to study the residual stresses in machined surfaces of single crystal copper by diamond tools. We adopt a fixed cutting speed of 400m/s, vary depth of cut from 0.5nm to 1.5 nm, and change the tool rake angle from −30° to +30°. The results are then compared and discussed in the following aspects. First, it is found that both tool rake angle and depth of cut affect the morphologies of the formed chips, and as well as the cutting force evolution during machining process. Second, the normal residual stress in the tangential direction is more significant and has a clearer pattern than those in other directions for all the simulation cases. As such, the focus of the study is on this particular stress component. Third, with the increase of depth of cut, the maximum tensile residual stress decreases, and the residual stress becomes compressive at a shorter distance into the machined surface. Also, the use of negative rake angle makes the residual stress overall more tensile when closer to surface, and more compressive as the depth into surface further increases. It is actually consistent with traditional metal machining theory. The use of negative tool rake angle requires a larger thrust force, and this in turn overall makes the residual stress more compressive.
Application of Pulse Wave Analysis in a Personal Health Monitoring Device
Authors: Malinin Len , Naumov Valery
Published: October 2013

Pulse wave (PW) is a physiological event, observable and measurable in the arterial system during blood circulation. One of characteristics that can be determined from a PW record is heart rate variability (HRV), an indication of beat-to-beat alterations in the heart rate. HRV is an accurate and reliable reflection of several physiological factors modulating the normal rhythm of the heart. HRV has escalated in use as an important diagnostic tool which indicates the balance between sympathetic and parasympathetic branches of the autonomous nervous system (ANS) and the synchronization between them. HRV patterns are also sensitive to changes in emotional state and can be used to distinguish positive and negative emotions. However, HRV is just one of characteristics that can be extracted from a good quality pulse wave record. Other characteristics of the PW in the time and frequency domains can serve as an indication of the status of a cardio-vascular system.

Modern personal health monitoring tools, which use data processing capability of smartphones and personal computers, make daily or even continuous HRV analysis available for users who are affected by sedentary life style, high stress, and fatigue. The practical application of the PW monitoring requires, besides software and electronic, selection of clinically meaningful characteristics of the pulse wave and communicating them to a non-medical user. For this purpose, it is proposed to use, in addition to HRV, to use the characteristics based on duration of the four phases of the pulse wave, and compare them with the baseline level obtained for the same user under non-stressed conditions. Deviations from the baseline are presented to the user. Correlation of these readings with objective parameters of the cardio-vascular system is supported by clinical data.
Evaluation of Effective Elastic Mechanical Properties of Graphene Sheets
Authors: Alzebdeh Khalid I.
Published: October 2013

The mechanical behaviour of a single-layer nanostructured graphene sheet is investigated using an atomistic-based continuum model. This is achieved by equating the stored energy in a representative unit cell for a graphene sheet at atomistic scale to the strain energy of an equivalent continuum medium under prescribed boundary conditions. Proper displacement-controlled (essential) boundary conditions which generate a uniform strain field in the unit cell model are applied to calculate one elastic modulus at a time. Three atomistic finite element models are adopted with an assumption that force interactions among carbon atoms can be modeled by either spring-like or beam elements. Thus, elastic moduli for graphene structure are determined based on the proposed modeling approach. Then, effective Young’s modulus and Poisson’s ratio are extracted from the set of calculated elastic moduli.

Results of Young’s modulus obtained by employing the different atomistic models show a good agreement with the published theoretical and numerical predictions. However, Poisson’s ratio exhibits sensitivity to the considered atomistic model. This observation is supported by a significant variation in estimates as can be found in the literature. Furthermore, isotropic behaviour of in-plane graphene sheets was validated based on current modeling.
Analysis of Knob Traces Based on Changes in Armrest’s Length and Central Axis Location of Grahamizer
Authors: Kim Jong Hyun , Chun Keyoung Jin , Hong Jae Soo , Kim Chang Won , Hong Jung Hwa
Published: October 2013

The hemiparalysis, which is a widely known side effect of the disease, requires consistent and accurate rehabilitation exercise treatment. The Grahamizer is a representative piece of equipment for such treatment. Because it consists of a double pivot system, under exercise, the irregularly moving pivots could create an unintended movement and malfunction. Using the Grahamizer, this study analyzed movement patterns based on changes in the armrest’s length and the central axis location for a stable and accurate upper limb rehabilitation exercise.

Eight healthy subjects participated in the study. The Grahamizer, which allows the length of the armrest and the central axis location to be adjusted, was used for experimental equipment. The length could be adjusted to five levels (280mm, 220mm, 160mm, 100mm, and 40mm), and the location ranged from 5 levels to 1 level based on the length of the arm support (280mm: 5positions, 220mm: 4positions, 160mm: 3positions, 100mm: 2positions, 40mm: 1position). A marker located above a knob traced the knob’s movements. The experiment was conducted three times. Each subject held the knob and implemented rotational movements passively, with an angular velocity of 30°/s. After integrating the subjects’ movement traces, the tendency was analyzed. A previous study provided an analysis of the elbow and shoulder joint movements under a normal upper-body rotation movement. This study on movement traces was conducted based on those results.

Longer armrest lengths and greater distances between the central axis location and knob showed greater stability for the rotation movements. Remarkable results were found for changes in the axis location. However, smaller distances between the axis location and knob revealed larger movement traces. A previous study found, when a counterclockwise rotation was defined as 0°∼360°, that an elbow motion of 0°∼180° is flexion and 180°∼360° is extension. The shoulder joint motions are similar: 0°∼90°: medial rotation, 90°∼180°: lateral rotation, 180°∼270° medial rotation, and 270°∼360°: lateral rotation. According to the previous study, with a larger trace (smaller distance between the axis location and knob), the rotation movements of the elbow and shoulder are more accurate from 0° to 180° than from 180° to 360°.

The experiment confirmed that the Grahamizer’s armrest axis location has an impact on movement traces, and changes in the traces prevented the intended joint exercise. Under the circumstances, the location is an important design variable when developing the Grahamizer.
Effects of Variable Non-Central Locations of Bonded Double Doubler Joint System on Free Flexural Vibrations of Orthotropic Composite Mindlin Plate or Panel Adherents
Authors: Yuceoglu U. , Güvendik Ö.
Published: October 2013

This study investigates the “Effects of Variable Non-Central Locations of Bonded Double Doubler Joint System on Free Flexural Vibrations of Orthotropic Composite Mindlin Plate or Panel Adherents”. The problem is theoretically analyzed and is numerically solved in terms of the natural frequencies and the corresponding mode shapes of the entire “System”. The “Bonded Double Doubler Joint System” and the “Plate of Panel Adherents” are considered as dissimilar “Orthotropic Mindlin Plates”. In all plate elements, the transverse shear deformations and the transverse and rotary moments of inertia are included in the analysis. The relatively very thin adhesive layers in the “Bounded Joint Region” are assumed to be linearly elastic continua with transverse normal and shear deformations. The “damping effects” in the adhesive layers and in all plate elements of the “System” are neglected. The sets of the “Dynamic Mindlin Equations” of both upper and lower “Doubler Plates” and the “Plate or Panel Adherents” and the adhesive layer equations are combined together with the orthotropic stress resultant-displacement expressions resulting in a set of “Governing System of PDE’s” in a “special form”. By making use of the “Classical Levy’s Solutions”, in aforementioned “Governing PDE’s” and following some algebraic manipulations and combinations, the “Governing System of the First Order Ordinary Differential Equations” are obtained in compact “state vector” forms. Thus, the “Initial and Boundary Value Problem” at the beginning is finally converted into a “Multi-Point Boundary Value Problem” of Mechanics (and Physics). These analytical results developed facilitate the present method of solution that is the “Modified Transfer Matrix Method (MTMM) (with Interpolation Polynomials)”. The final set of the “Governing System of ODE’s” is numerically integrated by means of the “MTMM with Interpolation Polynomials”. In this way, the natural frequencies and the mode shapes of the “Bonded System”, depending on the variable non-central location of the “Bonded Double Doubler Joint System” are computed for several sets of the far left and the far right “Boundary Conditions” of the “Orthotropic Plate or Panel Adherents”. It was observed that, based on the numerical results, the mode shapes and their natural frequencies are very much affected by the variable position (or location) of the “Bonded Double Doubler Joint” in the “System”. It was also found that as the “Bonded Double Doubler Joint” moves from the central position in the “System” towards the increasingly non-central position, the natural frequencies (in comparison with those of the central position) changes, respectively. The highly-stiff “Bonded Double Doubler Joint Region” becomes “almost stationary” in all modes in “Hard” Adhesive cases.
Degradation Mechanism of Hot Water Immersed Glass SMC
Authors: Hamano Kotatsu , Yang Yuqiu , Zhang Zhiyuan , Hamada Hiroyuki
Published: October 2013

Due to its high productive, low cost and excellent properties, sheet molding compound (SMC) is widely used in many areas, including automobiles, aerospace, electronics, defense, energy, recreational and home-related industries. At current study, SMC molding panels were cut from bath tab moldings, and tensile specimens in two directions were prepared from the panel. The materials were made of 25mm-length glass fiber, unsaturated resin and other filler. Hot water immersion test was conducted at 90 °C until 1500 hours from one side and double side of the plate. Not only elastic modulus and tensile strength but also initial fracture stress obtained from both stress-strain curve and acoustic emission (AE) measurement were obtained. According to initial fracture stress’s change, it is found that the degradation behavior depended on the interfacial properties. Also it was shown that initial fracture stress can be used as allowable design stress.
Development of a Predictive Design Methodology for Structural Polymers Subject to Long-Term Loadings
Authors: Jackson Julie R. , Vallee Glenn E.
Published: October 2013

A methodology for designing polymeric service components for resistance to creep rupture is presented. One of the major difficulties encountered when designing service components that must carry loads for extended periods of time, particularly at elevated temperatures, is the prevention of failures caused by creep rupture. Creep rupture typically occurs at stresses well below the static or quasi static failure stresses commonly used to evaluate the safety of the design. A predictive method is therefore required to guard against such failures.

A Delrin 100 polymer is studied and its creep and creep rupture characteristics at temperatures ranging from 23°C to 85°C are determined. These properties are then used to formulate viscous creep and creep rupture models for use in the commercially available ABAQUS finite element program. The creep material model uses standardized creep test data, and the creep rupture model utilizes an element failure criteria used to predict the time to failure under various stress and temperature conditions. These material models are verified experimentally by performing creep and creep rupture tests at elevated temperatures, and reasonable agreement is seen. An axisymmetric finite element model of a typical service component used in a construction hand tool is then developed using the creep and creep rupture models developed for use in ABAQUS. Creep rupture is predicted over a range of loads and temperatures which are expected in service. Two creep rupture test fixtures are then designed for testing of the service component studied using ABAQUS. These fixtures are used to perform testing of two components simultaneously, and are capable of being loaded into an oven together to allow testing at elevated temperatures to be performed. The prediction of the time to creep rupture under actual service conditions computed by ABAQUS shows reasonable agreement with the component testing.

A methodology for designing components for resistance to creep rupture failures is then developed which focuses on the determination of maximum allowable stresses for a given set of life and loading conditions. The methodology described in this report is validated experimentally by modifying the geometry of the service component to increase the maximum stress to a level which results in a creep rupture failure as predicted by ABAQUS. The component is tested at an elevated temperature and failure at a time near that predicted in the finite element analysis is seen. It is concluded that the utilization of this design methodology can increase service life at the temperatures and load levels seen in service.
Flight Simulation of a Hybrid Projectile to Estimate the Impact of Launch Angle on Range Extension
Authors: Wilhelm Jay P. , Jackson Edward R. , Browning Patrick , Huebsch Wade , Mucino Victor , Gautam Mridul
Published: October 2013

A Hybrid Projectile (HP) currently under design at West Virginia University was simulated to estimate the effects of barrel launch angle and flight position of wing deployment. The projectile is similar to a standard 60mm mortar, except that is has been equipped to achieve extended range. A Simulink model was developed based upon external ballistics. The flight performance of the WVU-HP-60 was compared to a standard M720 60mm mortar. The developed HP was considered to be a tube-launched UAV, that transforms, not directly after launch but sometime after for optimal gliding, and must be modeled with different flight profiles because after transformation the aerodynamics drastically change. Two models of the UAV were created to allow for design of controllers. They were the launch model and the projectile flight model. It was found that the projectile may exit the barrel with a two degree variation of launch angle. The simulations show that range extension is still viable, with this barrel exit variation, to within 10% of the maximum achievable range. A confidence area was also developed to determine how far the launch angle and wing deployment position could stray and still maintain a significant amount of range extension.