bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental observation on laterally loaded pile in unsaturated silty soil
Authors: Lalicata L.M. , Desideri A. , Casini F. , Thorel L.
Published: November 2018

An experimental study was carried out to investigate the effects of soil partial saturation on the behaviour of laterally loaded piles. The proposed study was conducted by means of centrifuge tests at 100g, where a single vertical pile was subjected to a combination of static horizontal load and bending moment. The study was conducted on a silty soil characterized with laboratory testing under saturated and unsaturated conditions. During flight, two different positions of water table were explored. The influence of density was investigated by compacting the sample with two different void ratios. Finally, the effects of a variation of saturation degree on the pile response under loading were studied by raising the water table to the ground surface. Data interpretation allows drawing different considerations on the effects of partial saturation on the behaviour of laterally loaded piles. As expected, compared to saturated soils, partial saturation always leads to a stiffer and resistant response of the system. However, the depth of the maximum bending moment is related to the position of the water table and the bounding effects induced by partial saturation appear to be more important for loose soils.
Medialization Laryngoplasty in Pediatric Patients With Unilateral Vocal Fold Immobility: A Case Series
Authors: Wolter Nikolaus E. , Ayele Nohamin , Kawai Kosuke , Hseu Anne , Nuss Roger
Published: November 2018

Objectives:

The aims of this study were to describe the impact of laryngoplasty in pediatric unilateral vocal fold immobility (UVFI) and to determine the impact of etiology and technique on voice and swallowing.

Methods:

A retrospective review was conducted of all children with UVFI undergoing medialization laryngoplasty at a pediatric hospital (2010-2017). Data including demographics, etiology, subjective voice quality, and swallowing function were collected.

Results:

The median age at first surgery among 25 patients with UVFI was 11 years (range, 1.2-25 years). The causes of UVFI were iatrogenic (76%), congenital (16%), and idiopathic (8%). A total of 38 laryngoplasties (24 injections, 11 Silastic implants, 3 Gore-Tex) were performed. Postoperatively, 78% of patients reported improvements in voice and 81% in swallowing. The median duration of voice improvement was 1.0 years (range, 0.1-10 years), with no significant difference by etiology or laryngoplasty technique. Patients who were ⩾10 years of age at surgery reported voice improvement significantly more often than patients <10 years of age at surgery (94% vs 61%, P = .04).

Conclusions:

UVFI has a significant impact on health and quality of life. In this study we found that laryngoplasty is an effective way to address both voice and swallowing in pediatric UVFI. A greater proportion of children with improved voice quality were older at injection. Surprisingly, there was no difference in duration of voice improvement between permanent and absorbable materials. Although this duration would be considered acceptable for many injectable materials, the limited duration in permanent implantation techniques may represent the challenges of managing UVFI in the growing larynx of the pediatric population. Injection laryngoplasty with absorbable materials may serve as an adequate method of addressing UVFI in this population.
The Negative Associations Between Materialism and Pro-Environmental Attitudes and Behaviors: Individual and Regional Evidence From China
Authors: Gu Dian , Gao Shuqing , Wang Rong , Jiang Jiang , Xu Yan
Published: November 2018

Previous studies have shown that materialism is related to environmentalism, but unstable findings still exist. To clarify the relationships between materialism and pro-environmental attitudes and behaviors, the present study addressed some methodological issues and provided both individual- and regional-level evidence from China. Using data from the World Value Survey and the Chinese General Social Survey, we observed that materialism was negatively associated with pro-environmental attitudes (Study 1, n = 2,300; Study 2, n = 3,672) and pro-environmental behaviors (Study 2). Moreover, we found that pro-environmental attitudes partially mediated the association between materialism and pro-environmental behaviors in Study 2. We further searched for additional regional evidence in Study 3, and we found that the more materialistic regions are, the more energy is consumed. Results indicate that materialism is associated with decreases in pro-environmental attitudes and behaviors. We conclude with a discussion of the theoretical and practical implications of the research findings.
The Effect of Childhood Conduct Problems on Early Onset Substance Use: An Examination of the Mediating and Moderating Roles of Parenting Styles
Authors: Krohn Marvin D. , Larroulet Pilar , Thornberry Terence P. , Loughran Thomas A.
Published: November 2018

This study examines the role that effective parenting plays in the relationship between childhood conduct problems and the early onset of drug use. Effective parenting is posited to have a direct protective effect on drug use, a moderating effect on the relationship between conduct problems and early onset, and mediate the relationship between conduct problems and early onset. Two-generational panel data are used to examine these relationships among 263 parent–child dyads. Support is found for the direct protective effect of effective parenting on early onset .and for a partial mediating effect of parenting in the relationship between conduct problems and early onset. There was no support found for parenting moderating the risk that is posed by having childhood conduct problems. Implications for preventing childhood conduct problems from resulting in early onset of drug use through enhancing efforts to help parents cope with such problems are discussed.
Insinuation Anxiety: Concern That Advice Rejection Will Signal Distrust After Conflict of Interest Disclosures
Authors: Sah Sunita , Loewenstein George , Cain Daylian
Published: November 2018

When expert advisors have conflicts of interest, disclosure is a common regulatory response. In four experiments (three scenario experiments involving medical contexts, and one field experiment involving financial consequences for both parties), we show that disclosure of a financial or nonfinancial conflict of interest can have a perverse effect on the advisor–advisee relationship. Disclosure, perhaps naturally, decreases an advisee’s trust in the advice. But disclosure can also lead to concern that failure to follow advice will be interpreted as a signal of distrust. That is, rejecting the advice could suggest that the advisee is insinuating that the advisor could be biased by the conflict of interest. We show that this insinuation anxiety persists whether the disclosure is voluntary or required by law and whether the disclosed conflict is big or small, but it diminishes when the disclosure is made by an external source rather than directly by the advisor.
Supervision Strategies and Their Correlates: An Empirical Study of Chinese Community Correctional Staff
Authors: Jiang Shanhe , Lambert Eric G. , Zhang Dawei , Jin Xiaohong
Published: November 2018

While there are different approaches to dealing with offenders sentenced to community corrections, the three major ones are law enforcement (surveillance), therapeutic (rehabilitation), and crime opportunity prevention. Using the study of U.S. community corrections staff by Miller as a guide, the current study examined the supervision strategy used by Chinese community corrections staff in the Hubei province of China. Chinese community corrections staff were more likely to use the therapeutic and crime opportunity prevention approaches than the law enforcement model. Predictors of each of the three offender supervision approaches differed. The results from Chinese staff were similar in many ways to that found among U.S. staff reported by Miller but differed in some areas.
Who Supports Honor-Based Violence in the Middle East? Findings From a National Survey of Kuwait
Authors: Gengler Justin J. , Alkazemi Mariam F. , Alsharekh Alanoud
Published: November 2018

This study reports findings from what is, to the authors’ knowledge, the first nationally representative survey of public attitudes toward honor-based violence (HBV) in a Middle East country affected by such violence, and one of very few if any such national surveys undertaken in any context. In a telephone survey of 1,050 adult citizens of the Arab Gulf state of Kuwait, we collect attitudinal and behavioral measures of support for HBV. Facilitated by vignettes, item order randomization, and other survey best practices designed to reduce social desirability bias, the survey measures both support for HBV in principle and support for legislation permitting it. We also assess the correlates of views toward honor-based crimes, including demographic attributes (age, sex, and education), social indicators (economic status, religiosity, and tribal attachment), and political indicators (political interest, engagement, and ideology). These unique data permit investigation into the individual-level predictors of support for HBV among citizens of a country that has experience with HBV and laws that afford reduced punishment for perpetrators of honor killing. Results reveal, first, considerable levels of public support in Kuwait for HBV. Half of citizens report agreement that physical violence is justified as punishment for female adultery, whereas a third of both men and women say they would support a law permitting violence against a female adulterer. The strongest positive predictors of individual support for HBV are tribal attachment, religiosity, and support for political Islam. Surprisingly perhaps, permissive views of HBV are most likely among the youngest generation of Kuwaitis. The findings have important implications for understanding the factors that help explain the existence and persistence of HBV in the Middle East, in Islamic contexts, and elsewhere where it occurs.
Encouraging Upward Ethical Dissent in Organizations: The Role of Deference to Embodied Expertise
Authors: Bisel Ryan S. , Adame Elissa Arterburn
Published: November 2018

This article demonstrates that when supervisors encourage subordinates to defer to their embodied expertise, subordinates are more likely to voice explicitly moralized upward dissent to an unethical business request. Working adults ( N = 312) were randomly assigned to respond to an unethical business request from their boss in one of three scenarios that varied by how much the supervisor was known for encouraging deference to (a) embodied knowing, (b) intellectual reasoning, or (c) neither (i.e., a baseline control condition). Analyses revealed that participants were more than twice as likely to voice their private moral concerns explicitly with their boss when the supervisor was known for valuing subordinates’ embodied expertise (e.g., “going with your gut feelings”). In addition, participants also reported feeling significantly less communication anxiety in that same condition. Implications for leading organizational ethics conclude the article.
The effects of grooved rubber blocks on stick–slip and wear behaviours
Authors: Wang Xiao Cui , Mo Ji Liang , Ouyang Huajiang , Lu Xiao Dong , Huang Bo , Zhou ZR
Published: November 2018

This work presents an experimental and theoretical combined study of the effects of the elastic rubber blocks with different surface modifications on the friction-induced stick–slip oscillation and wear of a brake pad sample in sliding contact with an automobile brake disc. The experiments are conducted on the customized experimental setup in a pad-on-disc configuration. The experimental results show that (1) the friction system with the plain rubber block still exhibits visible stick–slip oscillation, but the intensity of the stick–slip oscillation is reduced to a certain degree compared with the Original friction system (without rubber block); (2) the grooved rubber blocks display a better ability to reduce the stick–slip oscillation compared with the plain rubber block; (3) the rubber blocks with a vertical groove (perpendicular to the relative velocity) or a horizontal groove (parallel to the relative velocity) or a diagonal groove (45° inclined to the relative velocity) on their surfaces can suppress the stick–slip oscillation more effectively with various degrees of success. The experimental results also reveal the varying effects of the different rubber blocks on wear. To explain the experimental phenomenon reasonably, a theoretical analysis is conducted to investigate the effects of different rubber blocks on both stick–slip oscillation and wear using ABAQUS. Furthermore, the analysis of the contact pressure on the pad interfaces and the deformation of the rubber blocks are studied to provide a possible explanation of the experimental results.
Assessing the influence of the road-tire friction coefficient on the yaw and roll stability of articulated vehicles
Authors: Mendes André de Souza , Fleury Agenor de Toledo , Ackermann Marko , Leonardi Fabrizio , Bortolussi Roberto
Published: November 2018

This article addresses the yaw stability of articulated vehicles by assessing the influence of the road-tire friction coefficient on the convergence region of a particular equilibrium condition. In addition, the boundaries of this region are compared to the boundaries of the non-jackknife and non-rollover regions to distinguish the instability phenomenon, jackknife or roll-over, responsible for this delimitation. The vehicle configuration considered in this analysis is composed by one tractor unit and one towed unit connected through an articulation point, for instance, a tractor-semitrailer combination. A nonlinear articulated bicycle model with four degrees of freedom is used together with a nonlinear lateral force tire model. To estimate the convergence region, the phase trajectory method is used. The equations of motion of the mathematical model are numerically integrated for different initial conditions in the phase plane, and the state orbits are monitored in order to verify the convergence point and the occurrence of instability events. In all cases, the longitudinal force on each tire, such as traction and braking, is not considered. The results show the existence of convergence regions delimited only by jackknife events, for low values of the friction coefficient, and only by rollover events, for high values of the friction coefficient. Moreover, the transition between these two conditions as the friction coefficient is changed is graphically presented. The main contributions of this article are the identification of the abrupt reduction of the convergence region as the value of the friction coefficient increases and the distinction of the instability events, jackknife or rollover, that define the boundaries of the convergence region.
Development of a magnetostrictive material–based electro-hydrostatic actuator with an active rotary rectifying valve
Authors: Zhu Yuchuan , Wang Zhenyu , Fei Shangshu
Published: November 2018

A magnetostrictive material–based electro-hydrostatic actuator with an active rotary valve for fluid rectification is presented in this article, which consists of a magnetostrictive material–based pump, an active rotary valve and a hydraulic cylinder. First, the magnetostrictive material–based pump plunger motion model is established, and the factors that affect the phase lag between the magnetostrictive material–based pump plunger displacement and the input voltage are discussed. Second, the flow area model of the active rotary valve and the kinetic model of the cylinder are established. After that, the phase compensation for the input voltage that influences the synchronous motion between the magnetostrictive material–based pump plunger and the valve spool is investigated. Finally, the simulation model is built in MATLAB/Simulink, and the results are subsequently verified with experimental data. The results indicate that the phase lag of magnetostrictive material–based pump plunger output displacement is mostly influenced by magnetization with a low driving frequency and by an eddy current with a high driving frequency. The compensation angle for the input voltage affects the output flow of the magnetostrictive material–based electro-hydrostatic actuator and the moving direction of the cylinder piston rod. For a magnetostrictive material–based electro-hydrostatic actuator rectified by the active rotary valve, at the driving frequency of 200 Hz, the peak output flow can reach 2.4 L/min, which is much higher than 1.1 L/min of a magnetostrictive material–based electro-hydrostatic actuator rectified by the passive reed valve.
Early Mesolithic activities at ancient Lake Duvensee, northern Germany
Authors: Groß Daniel , Lübke Harald , Schmölcke Ulrich , Zanon Marco
Published: November 2018

The ancient lake Duvensee in Schleswig-Holstein, Germany, is one of the prime locations in northern Europe for early Holocene research. Archaeological sites on the former lakeshore provide vivid illustrations of early Mesolithic life, with bark mats and other organic finds preserved, including evidence for the extensive use of hazelnuts. Although the area has been the subject of research for almost 100 years, a coherent summary of these discoveries has not yet been written. Here we review past research at Duvensee, and give some prospects for further research. We show that the Duvensee sites varied in their structure and chronology. While only a limited number of sites can be connected to hazelnut exploitation, some of them show signs of hafting and retooling and other domestic activities. At a few sites, specific hearths were excavated which can be connected with hazelnut roasting and other subsistence activities. Finally, we show that while most earlier studies focused almost exclusively on archaeological research questions, Duvensee has the potential to reveal not only transformations in human behaviour, but also environmental changes at a detailed scale; we therefore argue for a more holistic perspective and multidisciplinary approach to reconstructing prehistoric landscapes and cultural transformations.
Simulation of the Holocene climate over South America and impacts on the vegetation
Authors: Maksic Jelena , Shimizu Marilia Harumi , de Oliveira Gilvan Sampaio , Venancio Igor Martins , Cardoso Manoel , Ferreira Felipe Alexandre
Published: November 2018

We provide a comprehensive analysis of the Holocene climate and vegetation changes over South America through numerical simulations. Holocene climate for several periods (8 ka, 6 ka, 4 ka, 2 ka, and present) were simulated by an atmospheric general circulation model, forced with orbital parameters, CO2 concentrations, and sea surface temperature (SST), while the analysis of the biome distributions was made with a potential vegetation model (PVM). Compared with the present climate, our four simulated periods of the Holocene were characterized by reduced South Atlantic Convergence Zone intensity and weaker South American Monsoon System (SAMS). The model simulated conditions drier than present over most of South America and gradual strengthening of SAMS toward the present. The Northeast Brazil was wetter because of southward migration of the intertropical convergence zone (ITCZ). Moreover, SST conditions were the main forcing for the climate changes during the mid Holocene inducing larger austral summer southward ITCZ migration. PVM paleovegetation projections are shown to be consistent with paleodata proxies which suggest fluctuations between biomes, despite the fact that ages of dry/wet indicators are not synchronous over large areas of the Amazonian ecosystem. Holocene PVM simulations show distinct retreat in Amazonian forest biome in all four simulated periods. In 6 ka, present caatinga vegetation in Northeastern Brazil was replaced with savanna or dense shrubland. The simulations also suggest the existence of rainforest in western Amazonia and the expansion of savanna and seasonal forest in the eastern Amazon, with shifts in plant community compositions and fragmentation located mostly in ecotone regions. Moreover, our PVM results show that during the Holocene, the Amazonian tropical forest was smaller in area than today, although western Amazonia persisted as a tropical forest throughout the Holocene.
The European Union’s non-contractual liability following country and counterterrorism sanctions: Is there anything to learn from the Safa Nicu Sepahan case?
Authors: Messina Michele
Published: November 2018

This article focuses on the actions aimed at compensating for the damage suffered by natural and legal persons following the imposition of EU country or counterterrorism restrictive measures. The judgments in the Safa Nicu Sepahan case, where the EU Courts deliberated for the first time on the award of non-material damage, constitute the basis for the analysis of the relevant EU jurisprudence in the field often too reluctant to award damages, in accordance with the traditional conservative approach of the EU Courts towards the non-contractual liability of the Union. Despite the award of non-material damages, the judgments in Safa Nicu Sepahan might not necessarily entail a breakthrough towards an increased willingness of EU judges to award damages in the area of country or counterterrorism restrictive measures. They would rather constitute a natural and coherent evolution of the existing case law, strictly related to the specific circumstances of the case.
A new high-torque retarder based on combined effects of magnetorheological fluid and eddy current
Authors: Huang Hui , Chen Shumei , Wang Cheng
Published: November 2018

In this article, a new high-torque retarder combining the effects of magnetorheological fluid and eddy current is researched. The new retarder provides a part of the braking torque generated by the shear stress of the magnetorheological fluid and an additional braking torque generated by the effect of the eddy current on the rotors. This operating concept is realized by a common magnetic excitation circuit generated by a new structure with several separated coils. The configurations and design details of the new retarder, including the structure, material selection, and magnetic circuit, are discussed. The mathematical models of braking torque caused by the magnetorheological fluid and eddy current are also derived. Then, a finite element analysis is performed to verify the magnetic field design of the new retarder. Finally, a prototype is fabricated, and the relevant parameters are tested. The experimental result shows that the new retarder provides not only a stable braking torque at low speed but also a great increment of braking torque varied with rotation speed, which effectively improves the total braking torque compared with conventional magnetorheological retarders.
Frontline Workers’ Career Pathways: A Detailed Look at Washington State’s Medical Assistant Workforce
Authors: Skillman Susan M. , Dahal Arati , Frogner Bianca K. , Andrilla C. Holly A.
Published: November 2018

Medical assistants (MAs) are a rapidly growing and increasingly important workforce. High MA turnover, however, is common and employers report applicants frequently do not meet their needs. We collected survey responses from a representative sample of 3,355 of Washington’s MAs with certified status (MA-Cs) to understand their demographic, education, and employment backgrounds; job satisfaction; and career plans. Descriptive analyses showed 93.0% were female with a $19.91 mean hourly wage, and while generally satisfied, 56.2% indicated they would seek training or employment in another health care occupation within 5 years, with higher percentages among MA-Cs who felt overwhelmed by their workload and/or not satisfied with promotion opportunities. Regression analyses showed Hispanic, Black, and Asian MA-Cs were more likely than White MA-Cs to express interest in other health care careers. Strategies that strengthen MA career pathways and retain qualified workers should reward both employers and MAs and contribute to a stable and diverse workforce.
Authoethnography as an Act of Resistance Against Narratives of Hatred
Authors: Diversi Marcelo , Moreira Claudio
Published: November 2018

On November 8, 2016, a presidential candidate running on a campaign marked by exclusion and hatred against so many Others won the election and the U.S. Executive Branch. We, the authors, went from being concerned with the reverberations of Trump’s narrative of hatred to the shocking realization that we were entering an era of renewed politics of hatred and exclusion. In this article, we talk about how our autoethnography can help us find our common humanity in the spaces between Us and Them. We talk about our hope that autoethnography can help us trouble the simplistic fixed identities of the Other required for campaigns of hatred and exclusion, how it can help us stay anchored to the notion that hope for unconditional inclusion is not a choice but an ontological necessity.
Reverberations and Reverb: Sound Possibilities for Narrative, Creativity, and Critique
Authors: Gershon Walter S.
Published: November 2018

The performative nature of this article simultaneously functions at multiple levels. It is at once an article about, among other things, the significance of the sonic and its qualitative differences from more ocular forms of expression, the inability to discern between that which occurs of its own accord and that which is manufactured, and questions of attention, intention, and expression. It is also an inversion of how sound is most often utilized in scholarship. In this case, rather than sounds explicating text, the text of this article functions as a kind of libretto for the sonic version of this piece.
Living Eastern and Western Understandings of Dialogue and Narrating Practices of Language Revitalization in Tibet
Authors: Kang Dongjing , Rawlins William
Published: November 2018

This essay dramatizes three key characteristics of dialogue shared between Eastern and Western voices. They have been vividly enacted during the first author’s ongoing 7-year ethnographic encounters with Tibetans organizing through communicative relationships to preserve their mother tongue. Emerging from the intertexuality among Zhuang Zi’s and Martin Buber’s ideas and the (auto)ethnographic activities involved in composing this account, the characteristics include boundless bound (the cultivation of immanent freedom), purposeless purpose (dialogue as a process and context for purpose to evolve), and being while becoming (creativity in momentary transformation).
Does Juan Carlos or Nelson Obtain a Larger Price Cut in the Spanish Housing Market?
Authors: Raya Josep Maria , Nicodemo Catia , McMillen Daniel
Published: November 2018

Using a unique dataset and a nonparametric decomposition, we determine whether immigrants with native names, immigrants with foreign names, and natives have different outcomes in Spain’s housing market. Results suggest that immigrants with native names achieve greater discounts relative to immigrants with non-Spanish names. As a robustness check, we prove that this is not due to the country of birth. We observe that most of the difference in price across immigrant groups remains unexplained, which may imply some form of discrimination (pure or statistical) against immigrants with non-native names.
‘We always torment different people, so by definition, we are no bullies’: The problem of definitions in cyberbullying research
Authors: Kofoed Jette , Staksrud Elisabeth
Published: November 2018

In this article, we investigate the power of prevailing definitions within the research field of cyberbullying. We address how these definitions, mostly deriving from developmental psychology, have had a problematic influence on the way researchers, policymakers, practitioners working with interventions, and children and young people themselves approach the challenge of understanding and preventing cyberbullying and its consequences. We analyse how the definition of cyberbullying stemming from developmental psychology is inadequate in addressing the complexities of technologically mediated exclusionary processes in educational- and peer-group settings. The dominant research paradigm has suppressed such complexity by deeming irrelevant the extensive experience with cyberbullying of many children and young people. Thus, we argue that it is necessary for the research field to refine definitional work. Research on cyberbullying needs to draw on a broad spectrum of empirical data and incorporate multiple and diverse theoretical perspectives.
News values on social media: Exploring what drives peaks in user activity about organizations on Twitter
Authors: Araujo Theo , van der Meer Toni GLA
Published: November 2018

Since news circulation increasingly takes place online, the public has gained the capacity to influence the salience of topics on the agenda, especially when it comes to social media. Considering increased scrutiny about organizations, this study aims to understand what causes heightened activity to organization-related topics among Twitter users. We explore the extent to which news value theory, news coverage, and influential actors can explain peaks in Twitter activity about organizations. Based on a dataset of 1.8 million tweets about 18 organizations, the findings show that the news values social impact, geographical closeness, facticity, as well as certain influential actors, can explain the intensity of online activities. Moreover, the results advocate for a more nuanced understanding of the relation between news media and social media users, as indications of reversed agenda-setting patterns were observed.
Numerical and experimental study on hydrodynamic bulbous bow hull-form optimization for various service conditions due to slow steaming of container vessel
Authors: Yin Xun-bin , Lu Yu , Zou Jin , Wan Lei
Published: November 2018

In this article, an innovative hydrodynamic optimization design of bulbous bow hull-form under various service conditions resulting from the slow steaming of container vessel is presented, improving the overall performances for the real multi-variant usage situations more practical than the single specification of design, which includes both numerical computation and experimental validation. Effects of slow steaming–based statistical analysis of the actual operative occurrence during the lifetime is conducted, obtaining a combined probability density distribution of speed and displacement ushering in the evaluation of objective function. Three main component elements of the hydrodynamic optimization procedure that comprises parametric design of bulbous bow hull-form variation part, hydrodynamic numerical solver part, and optimization technique part are established and integrated. The proposed optimization process is subsequently applied to find the optimal bulbous bow of a container carrier for the hipping demand of different speeds and displacement distributed utilization, reducing significantly total conditions resistance of the hull, on a higher level decreasing the operative cost as well as gas emissions of the ship. Finally, there is an experimental campaign carried out between the optimal and original models to validate the numerical optimization computations. The compared investigation has provided a good agreement from the perspective of both numerical and experimental studies, as a result confirming the success of the present optimization framework and the utility value of the proposed optimization consideration on various service conditions during ship design stage.
Optimization of hydropneumatic suspension for articulated wheel loader based on kriging model and particle swarm algorithm
Authors: Zhao Huanyu , Wang Guoqiang , Lv Weidong , Cao Yue , Li Xuefei
Published: November 2018

Articulated wheel loaders that travel on unstructured roads experience severe vibration and poor stability. Introducing suspended axles on wheel loaders, which are traditionally constructed without wheel suspension, is desirable for ride comfort. This study mainly focuses on the parameter optimization of the hydropneumatic suspension to obtain the minimum root mean square of vertical accelerations under different driving conditions, thereby improving the ride comfort of the wheel loader. The multibody model of the wheel loader with hydropneumatic suspension was developed by RecurDyn in co-simulation with MATLAB/Simulink. The vertical acceleration root mean square at the seat position was analyzed when the wheel loader was traveling on class C, D, and E roads with different travel speeds. The surrogate model of the vertical acceleration root mean square with respect to the suspension parameters was established based on kriging method. The established surrogate model was then optimized using particle swarm optimization algorithm. The optimization results of the hydropneumatic suspension parameters of the wheel loader under different road excitations and driving speeds were obtained. Simulation and optimization results show that a well-designed hydropneumatic suspension system can significantly improve wheel loader performance in reducing the vertical acceleration at the seat position compared to a suspension system without optimization.
Dynamic modeling and analysis of the nut-direct drive system
Authors: Wang Zhaoguo , Feng Xianying , Li Peigang , Du Fuxin
Published: November 2018

For ball screw feed system, it has been a common practice that screw shaft is typically supported by bearings at both ends and is driven by a servo motor through coupling. However, this drive method has a relative low dynamic rigidity due to the influence of the support bearings. In this study, the nut-direct drive system is proposed, where the screw shaft is fixed at both ends and the screw nut is driven by the hollow servo motor through the bolted flange. In order to analyze the advantages of the nut-direct drive system compared with the classical drive, the dynamic models of the classical drive and the nut-direct drive are established based on lumped parameter method, respectively. According to the lumped parameter method, the influence of the table position, the length of screw shaft, and the nominal diameter of screw shaft on the natural frequency are analyzed. Furthermore, to analyze the influence of the mechanical system on position tracking accuracy, the mechanical systems of the classical drive and the nut-direct drive are integrated into the control system using the same control parameters, respectively. Results indicate that the nut-direct drive has faster responsiveness and better position tracking accuracy compared with the classical drive.
Fault diagnosis using improved pattern spectrum and fruit fly optimization algorithm–support vector machine
Authors: Wang Bing , Hu Xiong , Wang Wei , Sun Dejian
Published: November 2018

A fault diagnosis method using improved pattern spectrum and fruit fly optimization algorithm–support vector machine is proposed. Improved pattern spectrum is introduced for feature extraction by employing morphological erosion operator. Simulation analysis is processed, and the improved pattern spectrum curves present a steady distinction feature and smaller calculating amount than pattern spectrum method. Support vector machine with fruit fly optimization algorithm which can help seeking optimal parameters is employed for pattern recognition. Experiments were conducted, and the proposed method is verified by roller bearing vibration data including different fault types. The classification accuracy of the proposed approach reaches 87.5% (21/24) in training and 91.7% (44/48) in testing, showing an acceptable diagnosis effect.
Product redesign evaluation: An improved quality function deployment model based on failure modes and effects analysis and 2-tuple linguistic
Authors: Mi Chuanmin , Chen Yetian , Zhou Zhipeng , Lin Ching-Torng
Published: November 2018

An improved quality function deployment model based on integration of design failure mode and effects analysis and 2-tuple linguistic is proposed to guide the design scheme selection in the product redesign process. By adopting the entropy weight approach, the risk priority number of the risk assessment index is improved. Meanwhile, the improved results are fed back in quality function deployment to reassess the target values. In addition, the accuracy of the model on the basis of 2-tuple linguistic is improved in the process of information evaluation and data processing. Finally, the model is applied in the case of gear reducer to demonstrate its applicability. This model can not only improve the product’s reliability, but also enhance the quality of product by taking the customers’ needs and product’s risk priority number into consideration simultaneously and therefore improve the market competitiveness of the products.
A rotary magneto-rheological torque converter for tension regulation
Authors: Gang Li , Cheng-bin Du , Yong Feng
Published: November 2018

In this article, a drum type of transmission device has been developed, which is a double-layer cylinder structure. The working clearance between the inner and the external layers of the device has been filled with intelligent material named magneto-rheological fluid. To use it for tension regulation, theoretical model of its output torque has been constructed based on Bingham’s theory, and the coupling relationship between mechanical structure, electromagnetic circuit, and magneto-rheological fluid is analyzed and simulated using finite element analysis. Higher flux is directed onto the magneto-rheological fluid and greater shear frictions are generated subsequently. The design is practical, and a special seal mechanism which is a combination of magnetic seals and labyrinthine seals is applied in this research to improve sensitivity and to reduce leakage of the device. Then, experiments on prototype indicate that this device has significant advantages of quicker response, larger output, and less heat compared to traditional magnetic particle clutch and some existing disk-type magneto-rheological brakes which were recently reported. The new device may be applied widely in the related winding tension control field in the future.
FDA-Catalyst—Using FDA’s Sentinel Initiative for large-scale pragmatic randomized trials: Approach and lessons learned during the planning phase of the first trial
Authors: Cocoros Noelle M , Pokorney Sean D , Haynes Kevin , Garcia Crystal , Al-Khalidi Hussein R , Al-Khatib Sana M , Archdeacon Patrick , Goldsack Jennifer C , Harkins Thomas , Lin Nancy D , Martin David , McCall Debbe , Nair Vinit , Parlett Lauren , Temple Robert , McMahill-Walraven Cheryl , Granger Christopher B , Platt Richard
Published: November 2018

Background:

The US Food and Drug Administration’s Sentinel Initiative is well positioned to support pragmatic clinical trials. FDA-Catalyst combines direct contact with health plan members and/or providers with data in the Sentinel infrastructure. Here, we describe the rationale, feasibility analyses, and lessons learned from the planning phase of the first large pragmatic trial conducted using the Sentinel Initiative’s delivery system capabilities—IMplementation of a randomized controlled trial to imProve treatment with oral AntiCoagulanTs in patients with Atrial Fibrillation (the IMPACT-AFib trial).

Methods:

During the planning phase, we convened representatives from five commercial health plans, FDA, study coordinating centers, and a patient representative for protocol development, institutional review board preparation, and other activities. Administrative claims data from the plans were included in a retrospective cohort analysis to assess sample size for the trial. Members ≥30 years old with ≥365 days of medical/pharmacy coverage, ≥2 diagnosis codes for atrial fibrillation, a guideline-based indication for oral anticoagulant use for stroke prevention, and no evidence of oral anticoagulant use in the 365 days prior to the index atrial fibrillation diagnosis in 2013 were included. Exclusions for the analysis included other conditions requiring anticoagulation, history of intracranial hemorrhage, and gastrointestinal bleed. We calculated rates of oral anticoagulant use, transient ischemic attack or stroke, and bleeding in the 365 days following the index atrial fibrillation diagnosis.

Results:

A total of 44,786 members with atrial fibrillation with no evidence of recent oral anticoagulant use were identified. In total, 87% (n = 38,759) were classified as having a guideline-based indication for oral anticoagulants. Of those, 33% (n = 12,867) had a new oral anticoagulant dispensed during the following year, 15% (n = 5917) were hospitalized for stroke or transient ischemic attack, and 9% (n = 3469) for bleeding events. This information was used to develop the trial protocol including sample size, power calculations, and level of randomization.

Conclusion:

Sentinel infrastructure generated preliminary data that supported planning and implementation of a large pragmatic trial embedded in health plans. This planning identified unanticipated challenges that must be addressed in similar trials.
Glycocalyx Degradation Is Independent of Vascular Barrier Permeability Increase in Nontraumatic Hemorrhagic Shock in Rats
Authors: Guerci Philippe , Ergin Bulent , Uz Zuhre , Ince Yasin , Westphal Martin , Heger Michal , Ince Can
Published: November 2018

BACKGROUND:

Glycocalyx shedding after traumatic hemorrhagic or septic shock, as well as different resuscitation fluids, has been causally linked to increased vascular barrier permeability (VBP) resulting in tissue edema. In nontraumatic hemorrhagic shock (NTHS), it remains questionable whether glycocalyx degradation in itself results in an alteration of VBP. The composition of fluids can also have a modulatory effect on glycocalyx shedding and VBP. We hypothesized that the shedding of the glycocalyx during NTHS has little effect on VBP and that the composition of fluids can modulate these effects.

METHODS:

Fully instrumented Wistar-albino rats were subjected to a pressure-controlled NTHS (mean arterial pressure of 30 mm Hg) for 60 minutes. Animals were fluid resuscitated with Ringer’s acetate, balanced hydroxyethyl starch (HES) solution, or 0.9% normal saline to a mean arterial pressure of 80 mm Hg and compared with shams or nonresuscitated NTHS. Glycocalyx shed products were determined at baseline and 60 minutes after fluid resuscitation. Skeletal muscle microcirculation was visualized using handheld vital microscopy. VBP changes were assessed using plasma decay of 3 fluorescent dyes (40- and 500-kDa dextran and 70-kDa albumin), Evans blue dye exclusion, intravital fluorescence microscopy, and determination of tissue edema (wet/dry weight ratio).

RESULTS:

All glycocalyx shedding products were upgraded as a result of NTHS. Syndecan-1 significantly increased in NTHS (mean difference, −1668; 95% confidence interval [CI], −2336 to −1001; P < .0001), balanced crystalloid (mean difference, −964.2; 95% CI, −1492 to −436.4; P = .0001), and HES (mean difference, −1030; 95% CI, −1594 to −465.8; P = .0001) groups at the end of the experiment compared to baseline. Hyaluronan levels were higher at the end of the experiment in nonresuscitated NTHS (−923.1; 95% CI, −1216 to −630; P = .0001) and balanced crystalloid (−1039; 95% CI, −1332 to −745.5; P = .0001) or HES (−394.2; 95% CI, −670.1 to −118.3; P = .0027) groups compared to controls. Glycocalyx shedding resulted in microcirculation alterations as observed by handheld video microscopy. Total vessel density was altered in the normal saline (mean difference, 4.092; 95% CI, 0.6195–7.564; P = .016) and hemorrhagic shock (mean difference, 5.022; 95% CI, 1.55–8.495; P = .0024) groups compared to the control group, as well as the perfused vessel density and mean flow index. Despite degradation of endothelial glycocalyx, VBP as determined by 4 independent assays remained intact and continued to be so following fluid resuscitation.

CONCLUSIONS:

NTHS induced glycocalyx shedding and microcirculation alterations, without altering VBP. Fluid resuscitation partially restored the microcirculation without altering VBP. These results challenge the concept that the glycocalyx barrier is a significant contributor to VBP.
Intraluminal Pulmonary Vein Stenosis in Children: A “New” Lesion
Authors: Nasr Viviane G. , Callahan Ryan , Wichner Zachary , Odegard Kirsten C. , DiNardo James A.
Published: November 2018

Pulmonary vein stenosis (PVS) is a rare disorder that leads to progressive narrowing of the extrapulmonary veins. PVS has been reported in both children and adults and in its worse iteration leads to pulmonary hypertension, right ventricular failure, and death. Multiple etiologies of PVS have been described in children and adults. This review will focus on intraluminal PVS in children. Intraluminal PVS has an estimated incidence ranging from 0.0017% to 0.03%. It is associated with conditions such as prematurity, bronchopulmonary dysplasia, necrotizing enterocolitis, Smith-Lemli-Opitz syndrome, and Down syndrome. Cardiac catheterization and pulmonary vein angiography are the gold standard for diagnosis and anatomic delineation. Other imaging modalities including magnetic resonance imaging, chest tomography, and transesophageal echocardiography are increasingly being used. Mortality of PVS in children is approximately 50%. Predictors of mortality include involvement of ≥3 pulmonary veins, bilateral pulmonary vein involvement, onset of PVS in infancy, elevated pulmonary artery pressure or systolic pulmonary artery-to-aortic pressure ratio, right ventricular dysfunction, restenosis after surgery, distal/upstream disease, and disease progression to previously uninvolved pulmonary veins. Treatment includes catheter-based pulmonary vein dilations with or without stenting, surgical interventions, medical therapy, and in some instances, lung transplantation. Cardiac catheterization for PVS involves a comprehensive hemodynamic and anatomic assessment of the pulmonary veins as well as therapeutic transcatheter interventions. Several surgical strategies have been used. Sutureless repair is currently most commonly used, but patch venoplasty, endarterectomy, ostial resection, and reimplantation are used in select circumstances as well. Medical therapies such as imatinib mesylate and bevacizumab are increasingly being used in an effort to suppress the myofibroblastic proliferation seen in PVS patients. Lung transplantation has been used as an alternative treatment strategy for end-stage, refractory PVS. Nonetheless, despite the different innovative approaches used, morbidity and mortality remain high. At present, the preferred treatment strategy is frequent reassessment of disease progression to guide use of catheter-based and surgical interventions in conjunction with medical therapy.