bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of Magnetic Circuit and Finite Element Analysis of Stepped Ferrofluid Seal with Small Sealing Gap
Authors: Zhang Ruibo , Yang Xiaolong , Wang Guohong 
Published: November 2019

Abstract
For the sake of study the pressure capability of ferrofluid seals with small sealing gap, a diverging stepped ferrofluid structure with small sealing gap was designed according to the theory of stepped ferrofluid and magnetic path design, and the length and cross-sectional area of the permanent magnet (NeFeB) are obtained. On the basis of these parameters, the ferrofluid distribution of seal gap is calculated by using the magnetic ferrofluid element method, and the pressure capability is obtained, then the reliability of the magnetic path design is obtained according to the capability of withstand voltage. There are some findings as following after analysis and comparison. It is the magnetic flux leakage at the junction of the pole boot and NeFeB that cause pressure capability calculated by the magnetic path method is lower than that calculated by the finite element method.
Design Method of Engine Room Equipment Layout Based on Improved Fuzzy Comprehensive Evaluation
Authors: Zhigang Huang , Xinyu Zhang , Jingyu Liu 
Published: November 2019

Abstract
Engine room is the place where marine power equipments, pipelines and other equipments are arranged centrally. In order to optimize the design process of engine room equipment layout, this paper proposes a method for the optimization design of engine room layout baesd on improved fuzzy comprehensive evaluation. By constructing the personnel activity space model and equipment space model, formulating the engine room environment constraint conditions dominated by personnel experience factors and obtaining the feasible scheme of engine room equipment layout. By designing the evaluation model of equipment layout plan in the engine room, formulating the evaluation method dominated by fuzzy comprehensive evaluation algorithm and obtaining the optimal layout scheme. Based on fuzzy comprehensive evaluation method, the improved method directly retains the influence of the design experience factors of personnel, which can make engine room equipment layout and pipelines more in line with engineering requirements, as well as provide better equipment accessibility and personnel accessibility.
Structural Optimization for Stiffness and Stochastic Fatigue Life Improvement of a Sport Utility Vehicle Chassis
Authors: Wang Wenlin , Huang Bao , Du Jianming , Cheng Siyuan 
Published: November 2019

Abstract
To further improve the structural dynamic performance of the Land-Wind X-6 chassis, structural optimization was performed: An X-shape cross member with high stiffness is added to the chassis, in addition, the cross member connecting the two torsion bar attachments is also strengthened. Extensive Finite Element Analysis (FEA) demonstrates that the inadequate torsion stiffness has been greatly increased by 102.6% after optimization, and the adequate bending stiffness has also been slightly improved by 3.8%, in addition, the level of local stresses on the chassis has been considerably declined; After optimization, the fatigue life coefficient when the vehicle is running on A-class concrete road at a speed of 110 km/h has been improved by about 40.36%, and that when the vehicle is running on D-class macadam road at a speed of 60 km/h has been improved by about 33.43%. Followed industrial implementation, field test result and product feedback information verify that the structural optimization performed in this study is effective and significant.
Effect of Dynamic Balance Parameters on Vibration of Vertical and Horizontal Rotor System
Authors: Yan Zhong , Ji Wu , Kejin Ding 
Published: November 2019

Abstract
In this paper, a rotor test device for vertical-horizontal conversion is designed. The effects of unbalanced mass, dynamic balance position and other dynamic balance parameters on the vibration response of the rotor system are experimentally analyzed, and the difference of the vibration response of the rotor system between vertical and horizontal States is compared. The test results show that the vibration of the bearing base foot will increase after the dynamic balancing rotor is installed in the vertical shafting in the horizontal state; in order to ensure the dynamic balancing accuracy, the dynamic balancing of the vertical rotor system should be carried out on the vertical system as far as possible, and the aggravation should be carried out far away from the driving end. The research results in this paper can provide necessary support for the determination of dynamic balancing process and the study of dynamic characteristics of vertical rotors.
Modeling and Simulation Study of Intake System Characteristics of Wankel Engine for UAV
Authors: Xiaqing LIU , Minxiang WEI , Rui LIU 
Published: November 2019

Abstract
Starting from the actual working process of Wankel engine, the intake system model of Wankel engine is constructed based on the mean value engine model. The parameters to be determined in the model are identified by the least-square method based on the engine test data. According to the nonlinear characteristics of the intake system, the structure of the model is improved by introducing the speed correction term, and the problem that the error of original throttle air mass flow model is larger under the larger throttle opening is solved. The results of simulation and steady-state test show that the maximum relative error between simulation and experimental values of throttle air mass flow is less than +3% and that between simulation and experiment values of intake pressure is less than +2%.The parameter identification and structure of the model have high precision, which can calculate the basic air intake flow of Wankel engine accurately and shorten the development cycle of the electric control system of Wankel engine.
Transformation of Arctic ecosystems under impact of open-pit extraction of mineral resources
Authors: Selyanina S B , Ponomareva T I , Mikhailova G V , Churakova E Yu , Zubov I N , Yarygina O N 
Published: November 2019

Abstract
The article considers the influence of open-pit mining of diamonds on the state of Arctic ecosystems outside of the zone of the direct impact of the enterprise. To assess changes in natural complexes, a retrospective analysis was carried out on the basis of the data from social surveys of the local population using adapted methodological approaches and comparing descriptions of the biodiversity of aquatic macrophytes made in 1969-1970 and 2018. The comprehensive studies of peat soils and the laboratory modeling of the flow of the saponite into the watercourse were carried out, in order to understand the possible ways of the impact of diamond mining on natural complexes. The shallowing of the river, the change in the nature of soils in the lower reaches of the river, the crowding out a number of native species of aquatic plants by invasive macrophytes were educed. It is shown that saponite interacts with components of bog ecosystems, changes its physicochemical properties and forms intermolecular associates with dissolved organic matter. This contributes to the transport of mineral particles over long distances, to its accumulation in bottom sediments, and to the prolonged desorption, which creates favorable conditions for the introduction of invasive species.
Comparative assessment of drag reduction efficiencies of polymer solutions and surfactants at low temperatures
Authors: Kashlach E S , Berezina E M , Smirnova A S , Berezina I A , Manzhai V N , Fufaeva M S 
Published: November 2019

Abstract
The antiturbulent efficiency of solutions of high molecular weight polymers and that of micellar systems of surfactants are compared. The effect of the structural organization of polymer solutions and colloidal systems on their antiturbulent efficiency is shown. Hydrodynamic and physicochemical approaches are used to interpret the experimental results. It is shown that the use of polymers as drag reducing agents in main oil pipelines is more preferable at low liquid temperatures in northern latitudes (the Arctic).
Structure and properties of invar alloys for MIM technologies
Authors: Kulkov S N , Abdulmenova E V , Shadrin V S , Leonov A A , Levkov R V 
Published: November 2019

Abstract
The paper studied Fe-Ni alloys obtained by sintering from mixtures of powders. Powders with 30-40 wt. Ni were mixed with paraffin and wax binder and then pressed and sintered at 1300 °C during 1 hour. It has been shown that the face centered cubic lattice (γ-phase) and body centered cubic lattice (α-phase) are formed after sintering of powders mixture. The content of the α-phase decreases from 37 % to 2 % with increase of Ni concentration from 30 to 35 wt. % Ni in powders mixture. The average grain size of the γ-phase decreases from 26.5±12.3 μm to 18.3±9.1 μm, and porosity of samples increases from 13±1.4 % to 18.4±1.1 %.The lattice parameter of the γ-phase increases from 3.5849·10−10 m to 3.597·10−10 m and it corresponds to well-known invar alloys. The maximum value of the microhardness of sintered samples is 1.04±0.07 GPa. Thus, alloys obtained by sintering of Fe and Ni powder mixtures has an invar properties typical of cast alloys.
High-Temperature Laminated Ceramic Material Hfc-ZrB2-SiC-ZrO2 for the Development of the Arctic and Siberia
Authors: Burlachenko A G , Mirovoy Yu A , Buyakova S P , Dedova E S , Kulkov S N 
Published: November 2019

Abstract
Ultra-high-temperature ceramics based on zirconium diboride and silicon and hafnium carbides are presented as composites with ceramic matrix and oxidation-resistant surface. Relatively low density, high strength at extreme temperatures and operability at oxidative environment with temperature up to 2000°C make these materials useful for aerospace construction and power engineering. HfC-ZrB2-SiC-ZrO2 systems are presented, structural analysis and the results of temperature tests in high-enthalpy gas are provided. It was demonstrated that high resistance of HfC-ZrB2-SiC-ZrO2 system to high-temperature corrosion is achieved owing to formation of protective oxide layer with variable composition. A key area for the use of the material in the Arctic is the organization of heat-shielding structures in the oil and gas industry.
The influence of stress states on the martensitic transformation in Y-TZP ceramic
Authors: Sablina T.Yu. , Sevostyanova I.N. , Bayanov A.N. , Kulkov S.N. 
Published: November 2019

Abstract
It has been studied the influence of the type of stress state arising during different types of loading - for axial compression, diametral compression (Brazilian test) and three-point bending of Y-TZP ceramics with different grain sizes. It was shown that with increasing grain size of ceramics there is an increase in strength properties. The maximum values of all strength characteristics are fixed for ceramics with a grain size of 1.55 microns. It was found that on the fracture surfaces the formation of a monoclinic phase caused by the tetragonal–monoclinic transformation under the influence of applied stresses after axial compression test, Brazilian test and three-point bending test. As the average grain size increases, the content of the monoclinic phase increases after all types of mechanical tests. For ceramics with the average grain size of 0.53 µm, regardless of the type of loading, the content of the monoclinic phase on the fracture surface was approximately 5-7%. For ceramics with a maximum grain size of 1.55 microns after axial and diametrical compression tests, the content of the transformation phase increased to 27 % and after bending tests up to 39 %. The increased content of the monoclinic phase on the fracture surface after bending tests, in comparison with the axial and diametrical compression tests, is due to a complex stress-strain state, when during deformation areas with tensile and compressive stresses are formed on the fracture surface.
Algorithms and models of multirobot systems and their implementation in ROS
Authors: Shikhman M V , Shidlovskiy S V 
Published: November 2019

Abstract
Conducting research in the Arctic takes place in extreme conditions. In these conditions, it’s effective to use multirobot systems that can function for days under any weather conditions. The article discusses the basic principles of multirobot control systems. Mathematical models for the formation of control actions of multirobot are obtained. The basic methods for modeling multi-robot systems in ROS are described.
Field theory of monochromatic optical beams: I. Classical fields
Authors: Aiello Andrea 
Published: November 2019

Abstract
We study monochromatic, scalar solutions of the Helmholtz and paraxial wave equations (PWEs) from a field-theoretic point of view. We introduce appropriate time-independent Lagrangian densities for which the Euler–Lagrange equations reproduces either Helmholtz and PWEs with the z-coordinate, associated with the main direction of propagation of the fields, playing the same role of time in standard Lagrangian theory. For both Helmholtz and paraxial scalar fields, we calculate the canonical energy-momentum tensor and determine the continuity equations relating ‘energy’ and ‘momentum’ of the fields. Eventually, the reduction of the Helmholtz wave equation to a useful first-order Dirac form, is presented. This work sheds some light on the intriguing and not so acknowledged connections between angular spectrum representation of optical wavefields, cosmological models and physics of black holes.
The Association between Reward Sensitivity and Activity Engagement: the Influence of Delay Discounting and Anhedonia
Authors: Veldhoven Deni Tressova-van , Roozen Hendrik , Vingerhoets Ad 
Published: November 2019

AbstractAimReward sensitivity affects individuals’ motivation to engage in goal-directed behavior. Other concepts, critical for reward appraisal, that potentially influence activity participation encompass delay discounting and anhedonia. The aim of this study was to test the hypothesis that anhedonia and delay discounting influence the relationship between reward sensitivity and activity engagement.MethodsIn total, 37 inpatient patients with an alcohol use disorder (AUD) and 37 matched healthy controls completed the behavioral activation system scale (BAS scale), the Pleasant Activities List (PAL), the Snaith–Hamilton Pleasure Scale (SHAPS) and the Delay Discounting Task (DDT).ResultsPatients differed from controls on SHAPS, DDT-k, PAL substance-related activities (SRA), but not BAS and PAL non-substance-related activities (non-SRA). Correlational analyses revealed a strong correlation between BAS and PAL non-SRA in both patients (r = 0.53) and controls (r = 0.47), but also with PAL-SRA in patients (r = 0.40), although not controls (r = 0.09). BAS was negatively correlated with SHAPS in both groups and with DDT in controls. SHAPS was negatively linked to PAL non-SRA in both groups. The BAS-PAL non-SRA relationship was influenced by discount rates in controls.ConclusionA strong link exists between reward sensitivity and engagement in non-SRA in both groups. Delay discounting affects the reward sensitivity and non-SRA association in healthy controls, while anhedonia did not impact the association between reward sensitivity and engagement in (non-)SRA in both conditions.
Hepatitis C Virus Cure Rates Are Reduced in Patients With Active but Not Inactive Hepatocellular Carcinoma: A Practice Implication
Authors: Ogawa Eiichi , Toyoda Hidenori , Iio Etsuko , Jun Dae Won , Huang Chung-Feng , Enomoto Masaru , Hsu Yao-Chun , Haga Hiroaki , Iwane Shinji , Wong Grace , Lee Dong Hyun , Tada Toshifumi , Liu Chen-Hua , Chuang Wan-Long , Hayashi Jun , Cheung Ramsey , Yasuda Satoshi , Tseng Cheng-Hao , Takahashi Hirokazu , Tran Sally , Yeo Yee Hui , Henry Linda , Barnett Scott D , Nomura Hideyuki , Nakamuta Makoto , Dai Chia-Yen , Huang Jee-Fu , Yang Hwai-I , Lee Mei-Hsuan , Jun Mi Jung , Kao Jia-Horng , Eguchi Yuichiro , Ueno Yoshiyuki , Tamori Akihiro , Furusyo Norihiro , Yu Ming-Lung , Tanaka Yasuhito , Nguyen Mindie H ,   Real-World Evidence from the Asia Liver Consortium Investigators
Published: November 2019

Abstract

Background
Cure rates of hepatitis C virus (HCV) treatment with direct-acting antivirals (DAAs) for patients with active and inactive hepatocellular carcinoma (HCC) may differ, but well-controlled studies are limited. We aimed to evaluate DAA outcomes in a large East Asian HCV/HCC population compared with HCV/non-HCC patients.

Methods
Using data from the Real-World Evidence from the Asia Liver Consortium (REAL-C) registry (Hong Kong, Japan, South Korea, and Taiwan), we used propensity score matching (PSM) to match HCC and non-HCC (1:1) groups for age, sex, cirrhosis, prior treatment, HCV genotype, treatment regimen, baseline platelet count, HCV RNA, total bilirubin, alanine aminotransferase, and albumin levels to evaluate DAA treatment outcomes in a large population of HCV/HCC compared with HCV/non-HCC patients.

Results
We included 6081 patients (HCC, n = 465; non-HCC, n = 5 616) treated with interferon-free DAAs. PSM of the entire study population yielded 436 matched pairs with similar baseline characteristics. There was no statistically significant difference in the overall SVR rate of HCC (92.7%) and non-HCC (95.0%) groups. Rates of treatment discontinuation, adverse effects, and death were also similar between HCC and non-HCC groups. Among patients with HCC, those with active HCC had a lower SVR than inactive HCC cases (85.5% vs 93.7%; P = .03). On multivariable analysis, active HCC, but not inactive HCC, was significantly associated with lower SVR (OR, 0.28; P = .01) when compared with non-HCC.

Conclusions
Active HCC but not inactive HCC was independently associated with lower SVR compared with non-HCC patients undergoing DAA therapy, although cure rate was still relatively high (85%) in active HCC patients.
Net ultrafiltration rate and its impact on mortality in patients with acute kidney injury receiving continuous renal replacement therapy
Authors: Tehranian Shahrzad , Shawwa Khaled , Kashani Kianoush B 
Published: November 2019

AbstractBackgroundFluid overload, a critical consequence of acute kidney injury (AKI), is associated with worse outcomes. The optimal fluid removal rate per day during continuous renal replacement therapy (CRRT) is unknown. The purpose of this study is to evaluate the impact of the ultrafiltration rate on mortality in critically ill patients with AKI receiving CRRT.MethodsThis was a retrospective cohort study where we reviewed 1398 patients with AKI who received CRRT between December 2006 and November 2015 at the Mayo Clinic, Rochester, MN, USA. The net ultrafiltration rate (UFNET) was categorized into low- and high-intensity groups (&lt;35 and ≥35 mL/kg/day, respectively). The impact of different UFNET intensities on 30-day mortality was assessed using logistic regression after adjusting for age, sex, body mass index, fluid balance from intensive care unit (ICU) admission to CRRT initiation, Acute Physiologic Assessment and Chronic Health Evaluation III and sequential organ failure assessment scores, baseline serum creatinine, ICU day at CRRT initiation, Charlson comorbidity index, CRRT duration and need of mechanical ventilation.ResultsThe mean ± SD age was 62 ± 15 years, and 827 (59%) were male. There were 696 patients (49.7%) in the low- and 702 (50.2%) in the high-intensity group. Thirty-day mortality was 755 (54%). There were 420 (60%) deaths in the low-, and 335 (48%) in the high-intensity group (P &lt; 0.001). UFNET ≥35 mL/kg/day remained independently associated with lower 30-day mortality (adjusted odds ratio = 0.47, 95% confidence interval 0.37–0.59; P &lt; 0.001) compared with &lt;35 mL/kg/day.ConclusionsMore intensive fluid removal, UFNET ≥35 mL/kg/day, among AKI patients receiving CRRT is associated with lower mortality. Future prospective studies are required to confirm this finding.
Decentralisation of agri-environmental policy design
Authors: Bareille François , Zavalloni Matteo 
Published: November 2019

Abstract
We theoretically examine the gains of the decentralisation of agri-environmental policy design. We consider a model with homogeneous regions and joint production of local and global public goods from agriculture. Assuming that governments are characterised by different agency costs and knowledge of the PG values, we evaluate whether decentralisation is a suitable strategy to improve the efficiency of agri-environmental payments. We find that partial decentralisation always improves the welfare. We apply our theoretical model to the case of abandoned wetlands in Brittany. We find that national governments are the most suitable to design agri-environmental policies. Our results contribute to reflections on future Common Agricultural Policy.
Is the End of Educational Hypergamy the End of Status Hypergamy? Evidence from Sweden
Authors: Chudnovskaya Margarita , Kashyap Ridhi 
Published: November 2019

AbstractThe reversal of the gender gap in higher education has been a major social transformation: women now outnumber men in higher education in nearly all OECD countries. Patterns of assortative mating have also changed as highly educated women increasingly form relationships with men who have less education (hypogamous unions). In this article, we draw on rich register data from Sweden to ask whether the emergence of hypogamous unions signals the emergence of a new female status dominance in unions. We also consider how the status distribution in these unions compares to homogamous (both highly educated) or hypergamous (he highly educated) unions. We use Swedish register data and study couples who have their first child together. We refer to a multi-dimensional view of status and use indicators of social class background, income, and occupational prestige. We find that in hypogamous unions, women tend to have a higher social class background and occupational prestige, but lower income than their partners. The income gap between partners is not simply a consequence of the gender wage gap, but driven by selection into different union types. Men and women who form hypogamous unions are negatively selected in terms of their income.
Comparison of the gut microbiota of Rana amurensis and Rana dybowskii under natural winter fasting conditions
Authors: Tong Qing , Du Xiao-peng , Hu Zong-fu , Cui Li-yong , Bie Jia , Zhang Qian-zhen , Xiao Jian-hua , Lin Yu , Wang Hong-bin 
Published: November 2019

ABSTRACT
Rana amurensis and R. dybowskii occupy similar habitats. As temperatures decrease with the onset of winter, both species migrate to ponds for hibernation. Our goal was to determine whether different species possess different intestinal microbiota under natural winter fasting conditions. We used high-throughput Illumina sequencing of 16S rRNA gene sequences to analyse the diversity of intestinal microbes in the two species. The dominant gut bacterial phyla in both species were Bacteroidetes, Proteobacteria and Firmicutes. Linear discriminant analysis (LDA) effect size revealed significant enrichment of Proteobacteria in R. amurensis and Firmicutes in R. dybowskii. There were significant differences in the gut microbiota composition between the species. The core operational taxonomic unit numbers in R. amurensis and R. dybowskii shared by the two species were 106, 100 and 36. This study indicates that the intestinal bacterial communities of the two frog species are clearly different. Phylum-level analysis showed that R. amurensis was more abundant in Proteobacteria and Verrucomicrobia than R. dybowskii was This is the first study of the composition and diversity of the gut microbiota of these two species, providing important insights for future research on the gut microbiota and the role of these bacterial communities in frogs.