bluuebunny/crossref_metadata_2025 huggingface dataset:
Migrant workers’ engagement with labour market intermediaries in Europe: symbolic power guiding transnational exchange
Authors: Samaluk Barbara
Published: September 2015

This article explores the strategies of migrant workers from post-socialist Central and Eastern Europe (CEE) within the process of transnational exchange characterized by transnational labour market intermediaries that have substantially altered the former national bilateral employment relations. Utilizing a Bourdieuian conceptual framework it examines Slovenian and Polish workers’ migration strategies and struggles to acquire and convert capitals within the process of transnational exchange and upon arrival in the UK. The article uncovers the (self-)colonial cultural capital embodied in CEE workers’ habitus that drives their strategies to take up various working and training opportunities in the UK in order to acquire (trans)nationally recognized cultural capital. This labour of acquisition drives Polish and Slovenian workers to seek specific cross-cultural and ethnic-niche intermediary services that can manipulate the most reliable symbolic signs in order to make profits from migrant worker-consumers. In this regard the article also exposes inter- and intra-ethnic variations.
Synthesis and properties of a new halogen-free flame-retardant epoxy resin curing agent
Authors: Liang Bing , Wang Gang , Hong Xiaodong , Long Jiapeng , Tsubaki Noritatsu
Published: September 2015

A novel intumescent flame-retardant curing agent, poly-( meta-xylylenediamine spirocyclic pentaerythritol bisphosphonate) (PMXSPB), was synthesized and subsequently characterized using Fourier transform infrared, proton nuclear magnetic resonance, and mass spectroscopies. PMXSPB was used as a flame-retardant and curing agent for preparing halogen-free flame-retarded epoxy (EP) resins. The thermal stability, mechanical properties, flame resistance, and morphology of the char layer of flame-retarded EP resins were investigated using thermogravimetric analysis, tensile and Charpy impact tests, limiting oxygen index (LOI), the UL94 test, and scanning electron microscopy, respectively. The results demonstrated that the addition of PMXSPB improved the flame resistance of EP resin composites, and the residual char ratio at 600°C was significantly increased. The flame-retarded composites filling with 3.01% phosphorus content (EP 100 g and PMXSPB 35 g) exhibited the best combination of properties, including a higher glass transition temperature (147°C), good thermal stability, an initial weight loss temperature of 269°C, and an LOI of 31.2. The vertical burning test reached the UL94 V-0 level, and the tensile and impact strengths were 51 MPa and 4.8 kJ m−2, respectively.
Continuous motion of a novel 3-CRC symmetrical parallel mechanism
Authors: Chen Ziming , Cao Wen-ao , Ding Huafeng , Huang Zhen
Published: September 2015

Parallel mechanisms (PMs) with three degrees of freedom (DOFs) have been studied extensively, especially the PMs with two rotational and one translational DOFs (2R1T PMs). One major problem of the 2R1T PMs is the inherent parasitic motion. In this paper, a novel 2R1T symmetrical parallel mechanism with no parasitic motion is proposed and studied. The moving platform and the base of this mechanism are mirror symmetric with respect to a mid-plane. This moving platform can realize continuous rotation about any axis or any point on the mid-plane and can have continuous translation along the normal line of the mid-plane. The constraint and motion characteristics of this mechanism are analyzed. The kinematics solutions and the Jacobian matrix are derived. The singularities of this PM are discussed. In the end, several numerical examples are given to show the continuous rotations and continuous translations of this PM. This kind of PMs has outstanding advantages of easy path planning and controlling.
Using nonlinear jumps to estimate cubic stiffness nonlinearity: An experimental study
Authors: Tang Bin , Brennan MJ , Lopes V , da Silva S , Ramlan R
Published: September 2015

Attempts are being made to improve mechanical design by using nonlinearity rather than eliminating it, especially in the area of vibration control and in energy harvesting. In such systems, there is a need to both predict the dynamic behavior and to estimate the system properties from measurements. This paper concerns an experimental investigation of a simple identification method, which is specific to systems in which the behavior is known to be similar to that of a Duffing-type system. It involves the measurement of jump-down frequencies and the amplitudes of displacement at these frequencies. The theoretical basis for the method is briefly described as, is an experimental investigation on a beam-shaker system. The results are comparable with those determined by the restoring force surface method. The method described in this article has the advantage that the data can be collected and processed more easily than the restoring force surface method and can be potentially more suitable for the engineering community than existing identification measures.
Understanding micropitting in gears
Authors: Clarke A , Evans HP , Snidle RW
Published: September 2015

Micropitting is a serious form of erosive wear, which can occur on the teeth of transmission gears. It is associated with roughness effects and surface fatigue and has become a particular problem in the speed-increasing gearboxes of wind turbines. This paper reviews the contributions which the authors have made towards an understanding of the basic mechanism of micropitting in gears based on analysis of the contact mechanics and elastohydrodynamic lubrication (EHL) of gear tooth surfaces under realistic operating conditions. Results are presented which demonstrate the crucial influence of EHL film thickness in relation to roughness (the ‘Λ ratio’) on predicted contact and near-surface fatigue. The important effect of plastic deformation, which takes place during the initial stage of running-in of gears, has also been investigated, and it has been shown that significant residual effects occur, which can contribute to the early formation of surface-initiated cracks.
Profiles evolutionary design and evaluation of mixing performance of screw elements for intermeshing counter-rotating twin-screw kneader
Authors: Wei Jing , Zhou Dongming , Zhang Aiqiang , Yang Yuliang , Chen Dabing
Published: September 2015

The profile designs of screw elements are very crucial to improving the mixing performance for the intermeshing counter-rotating twin-screw kneader. In order to find the inherent law among different profiles of screw elements and to derive a mathematical model which evolves different types of end cross-section profiles of screw elements, a universal mathematical model of end cross-section profiles of screw elements is presented in this work. Different types of profiles of screw elements, including those traditionally used can be obtained by evolutionary design method after changing the tooth number of female and male elements and other design parameters. Several typical screw elements with different types of end cross-section profiles are selected to analyze the mixing performance. Spatial flow patterns in flow channel of the screw elements are presented with particle tracking analysis by using mesh superposition technology. The mixing performance of different screw elements including distributive and dispersive mixing, contrastive analysis for some parameters, such as residence time distribution density function, segregation scale, rate of stretching, rate of shear, etc. are proposed. The results in this paper provide a data basis for the profiles selection of screw element for intermeshing counter-rotating twin-screw kneader.
Controlled synchronization of two nonidentical homodromy coupling exciters driven by inductor motors in a vibratory system
Authors: Kong Xiangxi , Chen Xiaozhe , Dou Jingxin , Zhang Xueliang , Wen Bangchun
Published: September 2015

In this work, the controlled synchronization of two nonidentical homodromy coupling exciters driven by inductor motors in a vibratory system is investigated. According to the previous works, using small parameter perturbation method deduces the conditions of implementing self-synchronous motion of two exciters. The shortage of self-synchronization method in design of vibratory system is found. The controlled synchronization method is proposed by employing sliding mode control and proportional–integral method on two inductor motors based on the master-slave control strategy to replace the self-synchronization. The stability of the controllers is proved by Lyapunov theorem. The performances of the control system are demonstrated by numerical simulation, which shows the controlled synchronization method is feasible. Additionally, the effects of various uncertainties including internal parameter perturbations and external disturbances on the control system are discussed, which indicate the proposed controllers have a good robustness.
Scaled tests and numerical simulations of rail vehicle collisions for various train sets
Authors: Li Rui , Xu Ping , Peng Yong , Xie You-qi
Published: September 2015

This paper investigates the energy absorption and dissipation pattern in train-to-train collisions. For this purpose, simplified scaled rail vehicle models were designed based on the energy-absorbing characteristics of honeycomb-based structures under static loading, and scaled tests were performed under dynamic loading. In this study, a one-eighth-scale model of train-to-train collisions for a three-car set was tested, and the corresponding displacement–time and velocity–time curves were obtained. The extents of energy absorption and dissipation were also calculated. Also, finite element simulations were conducted to simulate one-eighth-scale train collisions for three-car, five-car and eight-car sets. The finite element numerical simulation of scaled train collisions produced results that were consistent with experiment results. The simulation results also indicated that train sets do not significantly affect energy absorption and dissipation pattern. The energy-absorbing structure at the front of a train plays a major role in the collisions. Moving cars absorb slightly more energy than stationary cars in both the scaled test and finite element simulations.
A hybrid model for the prediction of low–frequency noise emanating from a concrete box-girder railway bridge
Authors: Zhang Xun , Li Xiaozhen , Zhang Jianqiang , Song Lizong , Li Yadong
Published: September 2015

Concrete box-girder bridges are widely used on high-speed railway and urban rail transit lines; however, the low-frequency noise generated by these systems has not been intensively studied. The prediction of bridge-radiated noise is a complicated procedure and can require prohibitively long computational times. This paper presents a hybrid finite element and statistical energy analysis (hybrid FE–SEA) procedure for the prediction of bridge-radiated noise, with the aim of reducing computational time while still guaranteeing accuracy. A simplified train–bridge coupling model is first introduced and solved in the frequency range 20–200 Hz; the wheel–rail interaction force is calculated and taken as the vibration excitation. The hybrid FE–SEA model is then constructed, in which the rail and ballastless track are modeled as the SEA subsystems and the bridge girder components as the FE subsystems. The bridge-radiated noise is finally estimated by considering each vibrating component of the bridge as a flat plate. The procedure is applied to predict the vibration and noise emanating from a simply supported concrete box-girder bridge with a standard span of 32 m, and the computed results are compared with those obtained from in-situ measurements. The numerical results are in good agreement with measured data, and comparisons between computed and measured results reveal that the noise radiation from adjacent spans needs to be considered at a perpendicular distance of 25 m from the track’s centerline. Furthermore, the vibration transmission mechanism and the acoustic contribution performance are investigated, based on the validated numerical model. The results show that the vibrational energy of the top slab has the highest value; however, the vibration of the flange cannot be ignored. Therefore, the top slab and the flange, which may respectively account for 50% and 25% of the overall noise contribution at far-field points, should be given priority when formulating noise-mitigation measures.
The active control of the lateral movement of a motor suspended under a high-speed locomotive
Authors: Yao Yuan , Zhang Xiaoxia , Liu Xu
Published: September 2015

In order to improve the dynamic performance of high-speed locomotives, an active control method for the movement of a suspended motor is proposed, in which a damper is replaced by an actuator. A simplified mechanical model of the flexible suspension system is established to study its dynamics and create an active control strategy. Then, a multi-body dynamic model of the locomotive is simulated to obtain the conditions for optimal control. The results show that a smaller damping of the lateral suspension is conducive to improving the dynamic performance of the locomotive; the system has a theoretical optimum damping ratio of between 0.1 and 0.3. A small level of damping results in a large lateral displacement of the suspended system, which cannot be allowed to occur due to space limitations. The optimal control is used with the aim of reducing the lateral vibration amplitude of the suspended motor system and bogie frame. The active control of the suspension system improves the lateral dynamic performance of the locomotive and effectively limits the lateral displacement of the suspended system relative to the bogie frame. Compared with a passive suspension approach, the lateral forces on the wheelset are reduced by up to 25% at speeds between 140 and 180 km/h on straight track, and the nonlinear critical speed is increased from 390 to 480 km/h.
The use of dynamic response to evaluate and improve the optimization of existing soft railway catenary systems for higher speeds
Authors: Nåvik Petter , Rønnquist Anders , Stichel Sebastian
Published: September 2015

An increasing demand for reduced travel times requires the exploitation of the full capacity of existing overhead railway catenary systems. This need has become an issue in Norway, as the majority of existing catenary systems are designed for a maximum speed of 130 km/h. In many regions, plans to reconstruct the railway line do not exist. Therefore, existing catenary sections must be optimized to increase a train’s velocity and reduce the total travel time. In this paper, the dynamic response is evaluated in an optimization investigation of an existing soft catenary system. A dynamic investigation that considers finite element models of existing soft railway catenary sections with original tension forces, current tension forces and suggested new tension forces for velocities at and above the design speed is conducted. The dynamic response is quantified by the interpretation of spectral densities and variations in their peak values. Due to more movement at mid-span than at the pole support, the effects from altering the tension forces and increasing the speed can be more accurately described and estimated by considering the dynamic content of the response at mid-span instead of the peak uplift at the pole support. A 23% increase in speed is possible for the system with the best tested new tension force setting, in which only the dynamic response and uplift at the pole support are considered.
Preliminary suitability analysis of carrier approach guidance and recovery of land-based aircraft
Authors: Hernando Jose-Luis , Martinez-Val R
Published: September 2015

Due to geopolitical, technical and economic reasons, Harrier V/STOL airplanes will soon be retired from service. Since many Navies rely on these aircraft for their combat capability, this will imply a severe operational trouble. One of the replacement possibilities is to modify ground-based designs and make them compatible with carrier operations. This paper presents the initial results of a study aimed at assessing existing ground-based combat airplanes from the point of view of their approach guidance and recovery compatibility with midsize aircraft carriers. The analysis includes operational and performance aspects, describes the complexity of these manoeuvres, and identifies the key variables intervening, crucial for carrier suitability.
A novel topology optimization method for composite beams
Authors: Ren Yiru , Jinwu Xiang , Zheqi Lin , Tiantian Zhang
Published: September 2015

A new topology optimization design method for aircraft composite beam under various loads is proposed. The cross-sectional stiffness characteristics of composite beam with arbitrary geometry are obtained using finite element method. Both of the warping and shear deformation are considered. To obtain better beam cross section, a multi-material optimization model including anisotropic and isotropic materials is employed. The density of candidate material at each element is designated as the design variables and updated with Sequence Linear Programming (SLP) of accurate gradient-based sensitivity. To avoid checkerboard problem, sensitivity filtering approach is used. Topology design of composite beam cross section with weight constraint is presented for square and airfoil cross section under various loads. The results show that the proposed method is suitable for the optimization design of composite beam, and innovative structures could be given. The external loads have great influence on the final topology shape of beam cross section.
How urban poor community leaders define and measure poverty
Authors: Boonyabancha Somsook , Kerr Thomas
Published: September 2015

This paper describes how urban poor community leaders in six nations (Cambodia, Nepal, the Philippines, Sri Lanka, Thailand and Vietnam) worked together to define poverty, assess its causes, and suggest how best to measure it and address it. Their work drew on over a thousand detailed household expenditure surveys from different settlements in a range of cities in the six nations. Five distinct groups could be distinguished among these urban poor households, and the work suggested that two poverty lines were needed. The community leaders also reviewed national and international poverty lines and found these to be incompatible with reality, especially the US$ 1.25/person/day poverty line. The paper draws some conclusions and describes plans for the country teams to further this work, including engaging with their national governments over the definition and measurement of urban poverty.
HIV prevalence, sexual behaviours and engagement in HIV medical care among an online sample of sexually active MSM in Venezuela
Authors: Perez-Brumer Amaya G , Oldenburg Catherine E , Biello Katie B , Novak David S , Rosenberger Joshua G , Mimiaga Matthew J
Published: September 2015

In Venezuela, members of a social and sexual partner networking site for men who have sex with men (MSM) completed an online survey regarding sexual behaviours and HIV medical care. Among the 2851 respondents, self-reported HIV prevalence was 6.6%. Of participants living with HIV, 73.2% reported taking antiretroviral medication and 56.6% reported complete adherence within the past month. Participants living with HIV were more likely to be older (aOR = 1.04 per one-year increase in age, 95% CI: 1.02, 1.06) and diagnosed with a sexually transmitted infection in the previous year (aOR 3.26, 95% CI: 2.11, 5.04). These data provide further understanding of the HIV epidemic among MSM in Venezuela, and potential targets for HIV prevention interventions.
Routine HIV testing in acute medical admissions in a high prevalence area reduces morbidity and mortality of HIV: a full cycle audit
Authors: Hill-Tout Rachel , Cormack Ian , Elgalib Ali
Published: September 2015

Late HIV diagnosis in the UK remains a major cause of morbidity and mortality. In line with British HIV Association recommendations, we implemented routine HIV Screening in Croydon University Hospital Acute Medical Unit in London after an audit in 2011 revealed very high levels of late diagnosis. Our re-audit assessed the impact of Acute Medical Unit screening and found that patients identified by screening, compared to those tested due to clinical suspicion of HIV, were significantly less likely to be diagnosed late, had fewer AIDS-defining illnesses and shorter hospital admissions. In addition, screening identified patients who were not in traditional ‘high-risk’ groups and patients who had defaulted HIV care and who subsequently re-engaged with care.
Ureaplasma parvum and Mycoplasma genitalium are found to be significantly associated with microscopy-confirmed urethritis in a routine genitourinary medicine setting
Authors: Cox Ciara , McKenna James P , Watt Alison P , Coyle Peter V
Published: September 2015

Summary

Inflammation of the urethra defined by an excess of polymorphonuclear leukocytes in the absence of sexually transmitted Chlamydia trachomatis and Neisseria gonorrhoeae is called non-chlamydial non-gonococcal urethritis (NCNGU). Although Mycoplasma genitalium is now recognised as causing a sexually transmitted infection, the clinical significance of the other Mollicute species is less clear. This study used specific real-time quantitative polymerase chain reaction assays to detect and quantify four Mollicute species, M. genitalium, M. hominis, Ureaplasma urealyticum and U. parvum, in urine specimens from men with and without NCNGU. A total of 165 urine specimens from male patients attending a genitourinary medicine clinic were eligible for the study, with microscopy-confirmed (≥5 polymorphonuclear leukocytes in urethral swab) NCNGU in 75 (45.5%) and non-confirmed NCNGU in 90 (54.5%). Chi-squared statistical analysis indicated a significantly higher prevalence of U. parvum (17.3% vs. 5.6%; p = 0.03) and M. genitalium (12% vs. 0%; p < 0.001) in NCNGU. In a subset analysis, M. genitalium was also significantly ( p = 0.03) higher in men who have sex with men (MSM; 13.5%) compared to non-MSM (3.1%). No significant associations were reported for U. urealyticum and M. hominis. In conclusion, this study supports a clinically significant role in NGNCU for both U. parvum and M. genitalium.
Notification following new positive HIV test results
Authors: Huang Ya-Lin A , Hutchinson Angela B , Hollis NaTasha D , Sansom Stephanie L
Published: September 2015

Client notification of a new HIV diagnosis is critical for timely access to treatment and reduction in behaviours associated with HIV infection. It is also an important input in HIV transmission and disease progression models. We used national, Centers for Disease Control and Prevention-funded HIV testing events data collected through the National HIV Prevention Program Monitoring and Evaluation system to update estimates of the proportion of newly identified HIV-positives notified of their status. We compared estimates from 2008 to 2010 across test technologies, settings, and HIV risk groups. In 2010, notification following a positive rapid test was 99.6% compared with 99.3% in 2008. Notification following a positive conventional test was 81.5% in 2010 compared with 80.8% in 2008. To realise the full promise of early HIV diagnosis and treatment for the prevention of additional HIV cases, efforts to ensure prompt notification following a new HIV diagnosis will be crucial.
Administration of tenofovir disoproxil fumarate-based antiretroviral therapy in an HIV-infected patient following unilateral nephrectomy
Authors: Biagi Mark , Badowski Melissa , Chiampas Thomas , Young Jeremy , Vaughn Pyrai , Shicker Louis , Patel Mahesh
Published: September 2015

Summary

We report the use of efavirenz 600 mg/emtricitabine 200 mg/tenofovir disoproxil fumarate 300 mg, once daily in a 47-year-old black man with a solitary kidney and human immunodeficiency virus (HIV). In 1990, he underwent radiation, chemotherapy, and ultimately, a unilateral nephrectomy for Wilms' tumor. Because of previous reports of tenofovir disoproxil fumarate-induced nephrotoxicity, our objective was to evaluate and monitor our patient's renal function over the course of 19 months based on serum creatinine, estimated creatinine clearance using the Cockroft-Gault equation, estimated glomerular filtration rate using the modification of diet in renal disease formula and urinalyses. After experiencing gastrointestinal side effects from other antiretroviral agents, our patient was switched to efavirenz/emtricitabine/tenofovir disoproxil fumarate in June 2013. At baseline, his serum creatinine was 1.35 mg/dL, estimated creatinine clearance 68.7 mL/min (based on actual body weight of 71.8 kg), estimated glomerular filtration rate 72.9 mL/min/1.73 m2, with a CD4 cell count of 119 cells/mm3 (5%) and an undetectable HIV viral load. In March 2015, his weight was 73.2 kg, serum creatinine 1.42 mg/dL, estimated creatinine clearance 65.2 mL/min, estimated glomerular filtration rate 68.1 mL/min/1.73 m2, with a CD4 cell count of 120 cells/mm3 (10%) and an undetectable HIV viral load. Other authors have reported tenofovir-induced nephrotoxicity in patients with a solitary kidney. Our patient had no evidence of nephrotoxicity over the course of 19 months on tenofovir disoproxil fumarate-based antiretroviral therapy (ART). He maintained adequate renal function, comparable to his baseline renal function. Our case report suggests that a tenofovir disoproxil fumurate-based ART may be a viable option for some patients with a solitary kidney. Additional studies and data are needed considering this is a small and relatively unstudied population.
A case of mixed connective tissue disease with pseudo-pseudo Meigs’ syndrome (PPMS)-like features
Authors: Cheah C K , Ramanujam S , Mohd Noor N , Gandhi C , D Souza Beryl A , Gun S C
Published: September 2015

Pseudo-pseudo Meigs’ syndrome (PPMS) has been reported to be a rare presentation of patients with systemic lupus erythematosus (SLE). However, such a presentation is not common in other forms of connective tissue disease. We presented a case of gross ascites, pleural effusion, and marked elevation of CA-125 level (PPMS-like features) that led to a diagnosis of MCTD. The patient responded to systemic steroid therapy.
Climate Change, Extreme Weather Events, and Human Health Implications in the Asia Pacific Region
Authors: Hashim Jamal Hisham , Hashim Zailina
Published: September 2015

The Asia Pacific region is regarded as the most disaster-prone area of the world. Since 2000, 1.2 billion people have been exposed to hydrometeorological hazards alone through 1215 disaster events. The impacts of climate change on meteorological phenomena and environmental consequences are well documented. However, the impacts on health are more elusive. Nevertheless, climate change is believed to alter weather patterns on the regional scale, giving rise to extreme weather events. The impacts from extreme weather events are definitely more acute and traumatic in nature, leading to deaths and injuries, as well as debilitating and fatal communicable diseases. Extreme weather events include heat waves, cold waves, floods, droughts, hurricanes, tropical cyclones, heavy rain, and snowfalls. Globally, within the 20-year period from 1993 to 2012, more than 530 000 people died as a direct result of almost 15 000 extreme weather events, with losses of more than US$2.5 trillion in purchasing power parity.
Transnational Education Remodeled
Authors: Knight Jane
Published: September 2015

Transnational education (TNE), interpreted as the mobility of education programs and providers between countries, has dramatically changed in scope and scale during the last decade. New actors, new partnerships, new modes of delivery, and new regulations are emerging. This has resulted in a proliferation of TNE terms and mass confusion in how they are used. The purpose of this article is to develop a common TNE framework of categories and definitions which can be used by both TNE sending and host countries. The framework needs to be robust enough to distinguish between different forms of TNE but flexible enough to be used by a wide range of institutions/countries around the world. Key elements common to twinning, franchise, joint/double/multiple degree programs as well as international branch campuses, cofounded institutions, franchise universities, and distance education are closely examined to ensure that the framework clearly differentiates between collaborative TNE and independent TNE modes of delivery. Much is at stake in terms of quality assurance, enrollment planning, policy/regulatory development, and the monitoring of trends if the proliferation and confusion among TNE terms continue. Different uses of the TNE framework are discussed, including the need for an internationally agreed-upon set of definitions as a precursor to developing an international protocol for worldwide collection of TNE data, similar to what United Nations Educational Scientific and Cultural Organization (UNESCO) and Organisation for Economic Co-Operation and Development (OECD) do for international student mobility.
Multi-objective geometry optimization of the Fish Bone Active Camber morphing airfoil
Authors: Woods Benjamin KS , Friswell Michael I
Published: September 2015

This work presents the development of a design optimization code for the geometry of the Fish Bone Active Camber morphing airfoil concept, which has been under development at Swansea University. This concept employs a biologically inspired architecture to provide highly anisotropic structural compliance, which creates smooth and continuous camber changes of large magnitude. Previous work has shown that this concept is capable of large lift coefficient control authority and significant reductions in drag over traditional trailing edge flaps. Further development of the concept requires a more robust design methodology that allows for an automated and thorough search of the available design space in order to optimize the aero-structural and system-level performance of the concept. To this end, this research extends a previously developed fluid–structure interaction analysis into a useful design tool by embedding it within a multi-objective structural optimization routine based on a genetic algorithm. The three objective functions of aerodynamic drag, added mass, and actuation energy are minimized concurrently. Example results from a specific operating condition are shown. Examination of the Pareto frontiers and the objective values of the population at large give insight into the structural behavior of the morphing concept. The objectives of mass and energy are found to be strongly competing, but good compromise points exist. The drag objective is found to be less sensitive than the others, with low drag being achievable across a range of designs with both low mass and low energy requirements, although the Pareto frontiers formed are not as well populated with regard to drag.
Experimental forward and inverse modelling of magnetorheological dampers using an optimal Takagi–Sugeno–Kang fuzzy scheme
Authors: Askari Mohsen , Li Jianchun , Samali Bijan , Gu Xiaoyu
Published: September 2015

An evolving encoding scheme is presented in this article for a fuzzy-based nonlinear system identification scheme, using the subtractive fuzzy C-mean clustering and a modified version of non-dominated sorting genetic algorithm. This method is able to automatically select the best inputs as well as the structure of the fuzzy model such as rules and membership functions. Moreover, three objective functions are considered to satisfy both accuracy and compactness of the model. The developed method is then employed to identify both forward and inverse models of a highly nonlinear structural control device, that is, magnetorheological damper. Experimental results showed that the proposed evolving Takagi–Sugeno–Kang fuzzy model can identify and grasp the nonlinear behaviour of magnetorheological damper very well with minimal number of inputs and fuzzy rules.
Feasibility of self-pre-stressing concrete members using shape memory alloys
Authors: Ozbulut Osman E , Hamilton Reginald F , Sherif Muhammad M , Lanba Asheesh
Published: September 2015

Shape memory alloys are a class of smart materials that recover apparent plastic deformation (∼6%–8% strain) after heating, thus “remembering” the original shape. This shape memory effect can be exploited for self-post-tensioning applications, and NiTi-based shape memory alloys are promising as shape memory effect is possible at elevated temperatures amenable to practical application compared to conventional NiTi. This study investigates the feasibility of self-post-tensioned concrete elements by activating the shape memory effect of NiTiNb, a class of wide-hysteresis shape memory alloys, using the heat of hydration of grout. First, the microstructure characterization of the NiTiNb wide-hysteresis shape memory alloys is discussed. Then, the tensile stress-induced martensitic transformations in NiTiNb shape memory alloy tendons are studied. Next, the temperature increase due to the heat of hydration of four commercially available grouts is investigated. Pull-out tests are also conducted to investigate the bond between the grout and shape memory alloy bar. Results show that the increase in temperature due to hydration heat can provide significant strain recovery during a free recovery experiment, while the same temperature increase only partially activates the shape memory alloys during a constrained recovery.
Guided Lamb wave–based structural health monitoring using a novel wave packet tracing method for damage localization and size quantification
Authors: Kim Inho , Chattopadhyay Aditi
Published: September 2015

In guided Lamb wave–based structural health monitoring, the interpretation of collected signals is a complex task because of the dispersive and multi-modal characteristics of guided Lamb waves. In this work, a novel wave packet tracing method for damage localization and size quantification is presented. This method involves creating time–space representations of the guided Lamb waves collected at a series of locations with a spatially dense distribution along paths at pre-selected angles with respect to the direction normal to the direction of wave propagation. The fringe patterns due to wave dispersion, which depends on the phase velocity, are selected as the primary features that carry information regarding the wave propagation and scattering. Simulated damage of various sizes, shapes, and locations is analyzed to visually and quantitatively demonstrate the wave packet tracing method.
Modeling of unstable behaviors of shape memory alloys during localization and propagation of phase transformation using a gradient-enhanced model
Authors: Badnava Hojat , Kadkhodaei Mahmoud , Mashayekhi Mohammad
Published: September 2015

In this article, a multi-dimensional gradient-enhanced constitutive model of shape memory alloys is developed. The model is developed to capture unstable behaviors of shape memory alloys during both the forward and reverse phase transformations. Also, influence of loading history on the start of the phase transformation during both forward and reverse transformations is considered in the model by introducing new transformation limits and phase fraction formulations. The model is implemented in a finite element code, and using a numerical framework, effects of loading, boundary condition, inhomogeneous deformations, imperfection, and geometry on the unstable behaviors of different shape memory alloy samples during nucleation and phase transformation are investigated. The obtained results are compared with the available experimental and numerical results in the literature. The obtained results show that the gradient enhancement removes pathological localization effects which would typically result from the softening influence. In addition, the numerical study proves that the mode can capture the basic features of phase transformation front patterns and their evolution during transformations.
Including the Family Member in Interdisciplinary Team Meetings
Authors: Graybill Emily , Esch Rachel C. , Vinoski Erin , Truscott Stephen , Torres Anna , Daniel Kirnel , Crenshaw Mark , Crimmins Daniel
Published: September 2015

This study explored the interaction patterns of family members of individuals with disabilities in a simulated interdisciplinary team problem-solving process. Participants included 15 members of a training cohort within a Leadership Education in Neurodevelopmental and Related Disabilities program. Family trainees and non-family trainees engaged in a simulated team discussion at two points during the training year (Time 1 and Time 2). To understand how family members and other professionals interact in interdisciplinary problem-solving meetings, we applied three coding schemes to the interdisciplinary team discussions to measure language similarity, dominance and domineeringness, problem solving, and balance of power. The results suggested there were trends in the communication dynamics between family trainees and non-family trainees at Time 1 and Time 2. For example, language similarity between groups was high at both Time 1 and Time 2, yet families were less successful at controlling the team conversation at Time 2. The implications of these and other results are discussed.
Farmworker Housing
Authors: Arcury Thomas A. , Summers Phillip
Published: September 2015

Migrant and seasonal farmworkers often reside in poor housing conditions which expose them to numerous hazards. These housing conditions are an issue of environmental health and justice. The photographs in this essay illustrate the living conditions confronted by farmworkers, offering a visual context for the reviews published in this issue of New Solutions. Farmworker housing conditions are often shocking to those who have not visited farmworker communities. Continued research is needed to document these conditions, how they affect the health of farmworkers, and provide leverage in the struggle to improve farmworker housing conditions.
Farmworkers Make Their Voices Heard in the Call for Stronger Protections from Pesticides
Authors: Brennan Kerry , Economos Jeannie , Salerno Marco M.
Published: September 2015

Farmworkers are calling for stronger workplace protections to prevent pesticide exposure and reduce health risks for workers and their families. In 1992, the U.S. Environmental Protection Agency (EPA) promulgated the Worker Protection Standard (WPS) as the primary set of regulations protecting the nation's 1–2 million farmworkers from occupational pesticide exposure. After more than 20 years, the EPA proposed revisions to the WPS. The proposed revisions were posted in the Federal Register and made available for public comment on 19 March 2014. In response to these revisions, farmworker organizations conducted outreach in agricultural communities to document and submit farmworkers' first–hand accounts of pesticide exposure as public comments. Through this process, farmworkers—a typically underrepresented, poorly protected, and disenfranchised population—made their voices heard and advocated for changes to improve their health and safety. Their comments in this article articulate the need for stronger workplace protections and enforcement measures to reduce health risks for workers, families, and communities.
Characteristics Associated With Sleep Duration, Chronotype, and Social Jet Lag in Adolescents
Authors: Malone Susan Kohl , Zemel Babette , Compher Charlene , Souders Margaret , Chittams Jesse , Thompson Aleda Leis , Lipman Terri H.
Published: September 2015

Sleep is a complex behavior with numerous health implications. Identifying sociodemographic and behavioral characteristics of sleep is important for determining those at greatest risk for sleep-related health disparities. In this cross-sectional study, general linear models were used to examine sociodemographic and behavioral characteristics associated with sleep duration, chronotype, and social jet lag in adolescents. One hundred and fifteen participants completed Phase I (self-reported sleep measures), and 69 of these participants completed Phase II (actigraphy-estimated sleep measures). Black adolescents had shorter free night sleep than Hispanics. Youth with later chronotypes ate fewer fruits and vegetables, drank more soda, were less physically active, and took more daytime naps. Based on these findings, recommendations for individual support and school policies are provided.
A Case of Ectopic ACTH-Producing Pulmonary Carcinoid Arising in an Extralobar Pulmonary Sequestration
Authors: Sato Seijiro , Kitahara Akihiko , Koike Terumoto , Hashimoto Takehisa , Ohashi Riuko , Kameda Yoichi , Tsuchida Masanori
Published: September 2015

Ectopic adrenocorticotrophic hormone (ACTH)–producing bronchopulmonary carcinoid arising in a bronchopulmonary sequestration is extremely rare. The case of a 67-year-old woman with a 1.7-cm nodule in the mediastinal side of the left lower lobe is presented. At 52 years of age, she was diagnosed as having ACTH-dependent Cushing’s syndrome (CS). However, no ectopic source of ACTH-secretion was detected. Seven years later, she underwent a bilateral adrenalectomy because of aggravation of her health condition. This time, tumor excision was performed by thoracoscopic surgery. The tumor adhered sparsely to the mediastinal pleura and the left lower lobe and was bluntly separated from these tissues. Pathologically, the tumor was a typical carcinoid arising in an extralobar pulmonary sequestration. Immunohistochemical staining confirmed the secretion of ACTH by bronchopulmonary carcinoid tumor cells. After surgery, the serum ACTH level was almost normalized, and the dexamethasone (1 mg) suppression test showed significant suppression of ACTH.
Frozen Section Interpretation of Pancreatic Margins
Authors: Liu Yong-Jun , Smith-Chakmakova Faye , Rassaei Negar , Han Bing , Enomoto Laura M. , Crist Henry , Hollenbeak Christopher S. , Karamchandani Dipti M.
Published: September 2015

Intraoperative assessment of pancreatic parenchymal margin during pancreatectomies is challenging and misinterpretation by the pathologist is a cause of incorrect frozen section (FS) diagnosis. Although the current literature supports that pancreatic margin FS diagnosis and its accuracy has no impact on the patient outcome for pancreatic ductal adenocarcinoma (PDAC) patients and reexcision in an attempt to achieve a negative intraoperative pancreatic margin after positive FS is not associated with increased overall survival; still it remains a routine practice in many institutions. To this end, we sought to assess the interobserver variation and accuracy of FS diagnosis between subspecialized gastrointestinal/pancreatobiliary (GI) and general pathologists. Seventy seven consecutive pancreatic parenchymal margin FSs performed on pancreatectomies for PDAC from 2010 to 2013 were retrieved at our institution. These were retrospectively evaluated by 2 GI and 2 general pathologists independently without knowledge of the original FS diagnosis or the final diagnosis. The specificity, sensitivity, positive predictive value, negative predictive value, and accuracy of GI versus general pathologist was 97.8% versus 87.5%, 61.1% versus 66.7%, 78.6% versus 41.4%, 95% versus 95.2%, and 93.5% versus 85.1%, respectively. The interobserver agreement between GI and general pathologists was fair (κ = .337, P < .001). The interobserver agreement between 2 GI pathologists was fair (κ = .373, P = .0005) and between 2 general pathologists was slight (κ = .195, P = .042). Although overall accuracy of subspecialized GI pathologists was higher than that of general pathologists, none had an accuracy of 100%. Our study reaffirms the challenging nature of these FSs.
The Gross Appearance of a NUT Midline Carcinoma
Authors: Wasserman Jason K. , Purgina Bibianna , Sekhon Harmanjatinder , Gomes Marcio M. , Lai Chi
Published: September 2015

The NUT midline carcinoma (NMC) is a recently described and highly aggressive tumor that usually involves the head and neck and anterior mediastinum. Most patients with NMC present with metastases and are often treated with neoadjuvant chemotherapy and/or radiation therapy. As a consequence, surgical specimens are often piecemeal excisions demonstrating treatment effect. In this report, we provide what is to the best of our knowledge the first complete gross description of NMC resected in toto and without prior treatment. The patient in this case underwent a pneumonectomy for a lung mass with curative intent. On gross examination, the tumor was found to be arising from the mediastinum with a smooth border, and demonstrated only minimal invasion of the surrounding structures. However, lymphovascular invasion was present throughout and there was extensive involvement of surrounding lymph nodes. The gross appearance of the tumor in this case reaffirms that NMC is an aggressive malignancy that usually metastasizes before it invades locally.
Effect of Obesity on Total Ankle Arthroplasty Outcomes
Authors: Schipper Oliver N. , Denduluri Sahitya K. , Zhou Ying , Haddad Steven L.
Published: September 2015

Background:

The purpose of this study was to evaluate the effect of obesity on intermediate- to long-term implant failure rates and survivorship after total ankle arthroplasty.

Methods:

A chart review was performed for all patients who underwent primary total ankle arthroplasty between 2004 and 2009 with a minimum 5-year follow-up. Patients were separated into a reference group with a body mass index less than 30 kg/m2 and an obese group with an index greater than or equal to 30 kg/m2. Minimum 5-year follow-up outcomes were available for 49 patients in the obese group and 48 patients in the nonobese group. Mean follow-up was 8.2 ± 2.0 years (range, 5.1-11.5 years) in the reference group and 7.7 ± 2.0 years (range, 5.0-11.9 years) in the obese group ( P = .26).

Results:

Based on multivariable logistic regression, obese patients had a significantly greater probability of implant failure by final follow-up (adjusted odds ratio, 2.8 [95% CI, 1.04-7.53]; P = .04). Cox regression analysis of 5-year implant survivorship showed no significant difference between the 2 groups (adjusted hazard ratio, 1.89 [95% CI, 0.77-4.65]; P = .17). When compared with obese patients with inflammatory or posttraumatic arthritis, obese patients with osteoarthritis demonstrated a significantly decreased 5-year survivorship (adjusted hazard ratio, 3.73 [95% CI, 1.05-10.43]; P = .04).

Conclusion:

This study demonstrated an increased long-term risk of implant failure among obese patients that was not seen in the intermediate term. Furthermore, obese patients with primary osteoarthritis were found to have a significantly decreased 5-year implant survivorship after ankle arthroplasty as compared with obese patients with inflammatory or posttraumatic arthritis and therefore should be counseled appropriately when deciding between arthroplasty and arthrodesis.

Level of Evidence:

Level III, retrospective comparative series.