bluuebunny/crossref_metadata_2025_split huggingface dataset:
Examination of vehicle impact against stationary roadside objects
Authors: Karapetkov S , Dimitrov L , Uzuniv Hr , Dechkova S 
Published: October 2019

Abstract
In this paper, a model of a car impact against a fixed roadside objects/safety barrier is presented and discussed to solve a mixed task: to determine the pre-impact velocity of the vehicle center of mass taking into consideration the recorded post-impact final rest position. The principle of conservation of mechanical energy was applied, whereas the energy of the rigid barrier deformation was estimated by the finite element method/FEM for an elasto-plastic body. FEM analysis was performed by integrating SolidWorks - SW Simulation software, the output data being the deformation of the safety barrier in the three dimensional space subjected to limited boundary conditions. The post-impact car motion was modelled by a multiscale spatial model, well established in modern accident reconstruction. The findings of the study point out the precision and accuracy of the crash pattern revealed in the accident reconstruction and essential in clarifying the situation with appropriate real facts. Two cases involving real-world head-on accident collisions against a fixed flexible barrier and a tank body are considered, which exemplify the adopted method.
Optimal design of self-retaining full complement cylindrical roller bearings
Authors: Ursache C , Barili A , Tudose L , Tudose C 
Published: October 2019

Abstract
Due to the presence of the ribs on both sides of the outer ring, the self-retaining full complement (cageless) cylindrical roller bearings have a very interesting particularity: the outer ring must be heated to create enough room between the already mounted rollers to allow the last roller to be inserted in the row. In addition, after cooling down, the rollers must support each other with a certain small clearance. For this reason, the internal geometry of the bearing as well as the precision of execution are more than critical. On the other hand, one of the most important problem in rolling bearing design is to establish the optimal set of internal dimensions in order to obtain the maximum value of the basic radial dynamic load rating. Pursuing this goal, in this paper, the optimal design of certain self-retaining cylindrical roller bearing is performed by means of the PSO (Particle Swarm Optimization) algorithm. In this approach two design variables were considered (the roller diameter and the diameter of the inner ring raceway) and both geometrical and thermal constraints were taken into account. A study referring to the sensitivity of the design to the small variation of the geometrical parameters is also presented.
Experimental determination of plastic gear durability
Authors: Hlebanja G , Hriberšek M , Erjavec M , Kulovec S 
Published: October 2019

Abstract
There are many plastic materials (POM, PA66, PEEK, …) and material combinations available. The question is which combination is the correct one. It depends on many factors, like expected durability and price, means of production, e.g. injection moulding or cutting, lubrication, microstructure, fillers, etc. The available data bases and data sheets do not present conclusive results. So, it is of the utmost importance for a company to produce effective tests which could present correct results for each individual case.
The gear tooth flank profile could be also optimized. S-gear shape is characterized by a convex concave contact in meshing start and end areas. This implies improved properties in comparison to involute gears, like lower contact pressure, less sliding and lower frictional losses, stronger root and improved oil film when lubricated.
The paper presents some material properties for the combinations which were tested on the fatigue test benches, presents testing rigs, refers to experiments and discusses results.
An application of multicriteria optimization in selection of the two-speed two-carrier planetary gear trains
Authors: Troha S , Stefanović-Marinović J , Rončević B , Anđelković B , Milovančević M , Marković K 
Published: October 2019

Abstract
This paper outlines the optimum selection procedure for a two-speed planetary gear train with four external shafts based on two design and operational criteria: radial dimensions and efficiency. The paper outlines how to quickly determine the structure and important basic parameters of two-speed planetary gear trains that meet predefined transmission requirements. The procedure is followed by a numerical example in which the optimal two-speed planetary gear train is selected, defined by the teeth number of the central gears, modules and transmission ratios. The relevance of the presented results is reflected in the fact that these transmissions offer significant advantages in systems which require speed change under load.
Analysis of the influence of direction of helical teeth in the universal helical gear reducer on service life of the bearings that support the reducer shaft
Authors: Rackov M , Kuzmanović S , Knežević I , Čavić M , Penčić M , Stefanović D , Dragoi M V 
Published: October 2019

Abstract
The paper analyses the problems of the influence of direction of helical teeth in the universal helical gear reducer on service life of the bearings that support the reducer shaft, i.e. on the overall load carrying capacity of universal gear reducer. Directions of helical teeth for all gear units is adopted in that way that the overall axial force at the reducer shaft is lowest as possible, i.e. axial forces of a shaft are in counterbalance. It is a practice the same output gear pair is used within a helical gear reducer made in universal casing for two- and three-stage gear reducer. However, these gears are produced with different directions of helical teeth in order to obtain the lowest axial force on the fifth geared shaft. However, some gear reducer manufacturers, trying to simplify the production and reduce the number of manufactured components, produce the gears with the same helical teeth direction for both two- and three-stage gear reducers. In that way, they do not reduce the value of axial force on the fifth geared shaft in three-stage gear unit, but they make addition of axial forces that certainly affects the service life of the bearings and thus the overall load carrying capacity of the gearbox. Analysing the concrete case, this paper researches the justification of implementation this procedure.
Transmission characteristics of simple cycloid drive with stepped planets
Authors: Mackic T , Tica M , Šuba R 
Published: October 2019

Abstract
Simple cycloid drive is a type of high-sensitive gear train, by which it is possible to realize high transmission ratios in single-stage. Their advantage is also reflected in the compactness and simplicity of production, as well as achieving greater efficiency compared to conventional planetary drive train. In this paper, the basic equations for obtaining the transmission ratios, torque and efficiency of simple cycloid drive with stepped planets are shown. The dependence between basic transmission ratio and basic efficiency was also examined to find the optimum value of the transmission ratio and determine the point at which the self-locking occurs.
The use of the gas flow model to improve the design of the piston-rings-cylinder system of a diesel engine
Authors: Koszalka G 
Published: October 2019

Abstract
The article presents the results of simulation research aimed at assessing the impact of selected dimensions of the rings and piston on the ring-pack operation and developing proposals of changes that will improve its performance. The object of the research was a diesel engine for delivery vehicles. A mathematical model of the ring-pack developed by the author of this work was used for the research. The results have shown that with restrictions imposed by the engine manufacturer regarding the scope of modernization, it is possible to significantly reduce or even eliminate the reverse gas flow from the inter-ring space to the combustion chamber, but this must be done at the expense of increased blow-by. The effect of proposed changes on the axial displacement of the rings in the grooves has also been discussed.
Passenger car steering pull and drift reduction considering suspension tolerances
Authors: De Rosa M , De Felice A , Fragassa C , Sorrentino S 
Published: October 2019

Abstract
Pull to side, Steering wheel misalignment and Drift leeward are handling anomalies affecting passenger cars travelling on straight paths. They represent a cost factor in the automotive industry, occurring in small but not negligible percentage of the overall car production. The present contribution is aimed at understanding which are their causes in terms of suspension tolerances, and at reducing their extent, in the specific case of vehicles with front Double wishbone suspension and rear Five arms suspension. The most influential parameters on handling irregularities have been identified through a design of experiment analysis. Then, after performing a sensitivity analysis by multibody virtual modelling, a correlation with experimental data from presetting and wheel aligner benches has provided sufficient information for setting tolerance thresholds, able to keep the handling anomalies under study within acceptable bounds. Pull to side and Steering wheel misalignment have been found to be mainly related to the set up phase of wheel angles (front camber angles influencing Pull to side, front and rear toe angles influencing Steering wheel misalignment), while the main cause of Drift leeward has been identified with (rear) ride steer.
Synthesis of Bi2FexNbO7 films applied as a catalyst for hydrogen production using visible-light photo-electrolysis
Authors: Scharnberg A R A , Pavlovic A , Alves A K 
Published: October 2019

Abstract
The seek for feasible sustainable mobility alternatives is a major concern of the society nowadays. By its turn, the production of hydrogen represents one of the main lines of study on clean energy, since hydrogen presents the possibility of storage and association with other renewable energy sources. In this regard, photo-electrolysis is a promising option for hydrogen generation. This process optimizes the electrolysis of water by using external energy to increase the potential of a photo-electrode, which must be a material that absorbs sunlight (usually a semiconductor activated by solar radiation), promoting the generation of H2 at the cathode. Titanium dioxide (TiO2) is the most applied semiconductor in photocatalytic applications. However, the band gap of this material limits its activity only under UV light, disregarding about 90% of incident solar radiation. Researchers explore catalysts that can be activated under visible light, such as bismuth-based mixed oxide semiconductors, which have attracted interest because of their excellent stability, visible light absorption, and photocatalytic properties. This research aims to develop and characterize photo-anodes based on bismuth, niobium and iron oxides (Bi2FexNbO7), for production of hydrogen via photo-electrolysis of water. The films were produced by the sol-gel process and deposited under a conductive glass slide by dip-coating. The effect of the iron concentration was evaluated by UV-Vis spectroscopy and SEM analysis, in order to estimate its hydrogen production potential.
Space use by animals on the urban fringe: interactive effects of sex and personality
Authors: Wat Katie K Y , Herath Anushika P H M , Rus Adrian I , Banks Peter B , Mcarthur Clare 
Published: October 2019

AbstractPersonality traits shape individual perceptions of risks and rewards, and so, should affect how animals value and use their environment. Evidence is emerging that personality affects foraging, space use, and exploitation of novel environments such as urban habitat. But the influence of personality is also hypothesized to be sex-dependent when primary motivation for space use differs between sexes, as often occurs in polygynous species. We tested the influence of personality traits, interacting with sex, on space use by the polygynous common brushtail possum, Trichosurus vulpecula, in an urban-woodland boundary in Sydney, Australia. We quantified personality traits, including exploration, using behavioral assays in an artificial arena. We also GPS-tracked free-ranging individuals, and measured range size, core area: home range, and proportional urban range. We found that personality traits affected space use either as a main effect or, as predicted, an interaction with sex. More exploratory animals, regardless of sex, had higher core area: home range ratios and proportionally larger ranges within urban habitat. However, less exploratory females yet more exploratory males had larger ranges. Our findings provide new insight into movement ecology by demonstrating, for the first time, the sex-dependent influence of personality. The demonstrated influence of personality on urban use by possums also suggests a personality filter for wildlife, as populations transition into urban areas. Finally, as individuals at the interface between urban and natural habitat are also a conduit between the two, a corollary of our findings is that there may be personality-mediated spread of disease across this boundary.
A Gaussian copula approach for dynamic prediction of survival with a longitudinal biomarker
Authors: Suresh Krithika , Taylor Jeremy M G , Tsodikov Alexander 
Published: October 2019

Summary
Dynamic prediction uses patient information collected during follow-up to produce individualized survival predictions at given time points beyond treatment or diagnosis. This allows clinicians to obtain updated predictions of a patient’s prognosis that can be used in making personalized treatment decisions. Two commonly used approaches for dynamic prediction are landmarking and joint modeling. Landmarking does not constitute a comprehensive probability model, and joint modeling often requires strong distributional assumptions and computationally intensive methods for estimation. We introduce an alternative approximate approach for dynamic prediction that aims to overcome the limitations of both methods while achieving good predictive performance. We separately specify the marker and failure time distributions conditional on surviving up to a prediction time of interest and use standard variable selection and goodness-of-fit techniques to identify the best-fitting models. Taking advantage of its analytic tractability and easy two-stage estimation, we use a Gaussian copula to link the marginal distributions smoothly at each prediction time with an association function. With simulation studies, we examine the proposed method’s performance. We illustrate its use for dynamic prediction in an application to predicting death for heart valve transplant patients using longitudinal left ventricular mass index information.
African Multi-Site 2-Year Neuropsychological Study of School-Age Children Perinatally Infected, Exposed, and Unexposed to Human Immunodeficiency Virus
Authors: Boivin Michael J , Chernoff Miriam , Fairlie Lee , Laughton Barbara , Zimmer Bonnie , Joyce Celeste , Barlow-Mosha Linda , Bwakura-Dangarembizi Mutsawashe , Vhembo Tichaona , Ratswana Mmule , Kamthunzi Portia , McCarthy Katie , Familiar-Lopez Itziar , Jean-Philippe Patrick , Coetzee Joan , Abrahams Nasreen , Gous Hermien , Violari Avy , Cotton Mark F , Palumbo Paul E 
Published: October 2019

AbstractBackgroundChildren living with human immunodeficiency virus (HIV) are at neuropsychological risk for cognitive and motor dysfunction. However, few prospective, multi-site studies have evaluated neuropsychological outcomes longitudinally among perinatally infected African children who received early antiretroviral treatment (ART).MethodsWe enrolled 611 children aged 5 to 11 years at 6 sites (South Africa [3], Zimbabwe, Malawi, Uganda). Of these, there were 246 children living with HIV (HIV+) who were initiated on ART before 3 years of age in a prior clinical trial comparing nevirapine to lopinavir/ritonavir (International Maternal Pediatric Adolescent Acquired Immunodeficiency Syndrome Clinical Trials [IMPAACT] P1060); 183 age-matched, exposed but uninfected (HEU) children; and 182 unexposed and uninfected (HUU) children. They were compared across 3 assessment time points (Weeks 0, 48, and 96) on cognitive ability (Kaufman Assessment Battery for Children, second edition [KABC-II]), attention/impulsivity (Tests of Variables of Attention [TOVA]), motor proficiency (Bruininks-Oseretsky Test, second edition [BOT-2]), and on the Behavior Rating Inventory of Executive Function (BRIEF). The cohorts were compared using linear mixed models, adjusting for site, child’s age and sex, and selected personal/family control variables.ResultsThe HIV+ cohort performed significantly worse than the HEU and HUU cohorts for all KABC-II, TOVA, and BOT-2 performance outcomes across all 3 time points (P values &lt; .001). The HUU and HEU cohorts were comparable. For the KABC-II planning/reasoning subtests, the HIV+ children showed less improvement over time than the HUU and HEU groups. The groups did not differ significantly on the BRIEF.ConclusionsDespite initiation of ART in early childhood and good viral suppression at the time of enrollment, the HIV+ group had poorer neuropsychological performance over time, with the gap progressively worsening in planning/reasoning. This can be debilitating for self-management in adolescence.
Geopolitics, Nationalism, and Foreign Direct Investment: Perceptions of the China Threat and American Public Attitudes toward Chinese FDI
Authors: Zeng Ka , Li Xiaojun 
Published: October 2019

Abstract
The rapid increase in recent years of Chinese outbound foreign direct investment (FDI) has prompted growing scholarly interest in its economic and political implications for host countries. However, relatively little attention has been paid to how concerns over the rise of China may shape public attitudes towards such investment. This article tests the link between threat perception and preferences for FDI in the United States. We argue that, due to heightened geopolitical concerns and nationalism, perceptions of the China threat negatively affect how the American public views the impact of incoming Chinese FDI. Using a survey experiment, we show that respondents are indeed less likely to support Chinese FDI when primed with information that highlights the security and economic threats posed by China than when they receive no such priming. Furthermore, causal mediation analyses reveal that the treatment effects of security and economic threats are mediated by respondents’ concerns about the challenges that Chinese FDI poses to national security as well as to American economy.
Mechanistic definition of the cardiovascular mPGES-1/COX-2/ADMA axis
Authors: Kirkby Nicholas S , Raouf Joan , Ahmetaj-Shala Blerina , Liu Bin , Mazi Sarah I , Edin Matthew L , Chambers Mark Geoffrey , Korotkova Marina , Wang Xiaomeng , Wahli Walter , Zeldin Darryl C , Nüsing Rolf , Zhou Yingbi , Jakobsson Per-Johan , Mitchell Jane A 
Published: October 2019

Abstract

Aims
Cardiovascular side effects caused by non-steroidal anti-inflammatory drugs (NSAIDs), which all inhibit cyclooxygenase (COX)-2, have prevented development of new drugs that target prostaglandins to treat inflammation and cancer. Microsomal prostaglandin E synthase-1 (mPGES-1) inhibitors have efficacy in the NSAID arena but their cardiovascular safety is not known. Our previous work identified asymmetric dimethylarginine (ADMA), an inhibitor of endothelial nitric oxide synthase, as a potential biomarker of cardiovascular toxicity associated with blockade of COX-2. Here, we have used pharmacological tools and genetically modified mice to delineate mPGES-1 and COX-2 in the regulation of ADMA.

Methods and results
Inhibition of COX-2 but not mPGES-1 deletion resulted in increased plasma ADMA levels. mPGES-1 deletion but not COX-2 inhibition resulted in increased plasma prostacyclin levels. These differences were explained by distinct compartmentalization of COX-2 and mPGES-1 in the kidney. Data from prostanoid synthase/receptor knockout mice showed that the COX-2/ADMA axis is controlled by prostacyclin receptors (IP and PPARβ/δ) and the inhibitory PGE2 receptor EP4, but not other PGE2 receptors.

Conclusion
These data demonstrate that inhibition of mPGES-1 spares the renal COX-2/ADMA pathway and define mechanistically how COX-2 regulates ADMA.
Image fusion of integrating fluoroscopy into 3D computed tomography in guidance of left atrial appendage closure
Authors: Mo Bin-Feng , Wan Yi , Alimu Abudushalamu , Sun Jian , Zhang Peng-Pai , Yu Ying , Chen Mu , Li Wei , Wang Zhi-Quan , Wang Qun-Shan , Li Yi-Gang 
Published: October 2019

Abstract

Aims
We evaluated the feasibility of left atrial appendage (LAA) closure guided by the image fusion of integrating fluoroscopy into 3D computed tomography (CT).

Methods and results
A total of 117 consecutive patients who underwent LAA closure with or without the image fusion were matched (1:2). Each LAA closure step of the Image fusion group was guided by the preprocedure CT and image fusion, especially in the plan of LAA measurement and transseptal puncture. All patients were successfully implanted with a WATCHMAN closure device. Comparing the two groups, the mean number of recapture times and the number of devices per patient of the Image fusion group were significantly lower (0.4 ± 0.5 vs. 0.7 ± 0.8, P = 0.031 and 1.0 ± 0.2 vs. 1.1 ± 0.3, P = 0.027, respectively). The one-time successful deployment rate by the support of the image fusion was higher than in the control group (66.7% vs. 44.9%, P = 0.026). Each case of the Image fusion group was completely occluded with one transseptal puncture, while five of the Non-image fusion group required redo transseptal punctures. During the 45-day follow-up, both group cases presented occlusion efficiency and no major adverse cardiac events were observed.

Conclusion
Image fusion technique integrating fluoroscopy into the 3D CT is safe and feasible which can be easily incorporated into the procedural work-flow of percutaneous LAA closure. The fusion image can play an important alternative role in the plan of LAA measurement and transseptal puncture site for improving the LAA closure procedure.
Relapse of aortopulmonary window 41 years after patch closure
Authors: Fukumoto Yuichiro , Hosoba Soh , Takagi Sho , Goto Yoshihiro 
Published: October 2019

Abstract
In this study, we describe a rare case of a 45-year-old man with a recurrence of aortopulmonary window (APW) 41 years after the initial patch closure for an APW at the age of 4. He presented with persistent cough and exertional dyspnoea. Imagings revealed a recurrence of APW, ascending aorta saccular aneurysm, and severe mitral and tricuspid regurgitation. Re-patch closure, ascending aortic replacement, and mitral and tricuspid annuloplasties were performed, followed by an uneventful postoperative course. The relapse of APW in the remote postoperative period is extremely rare.