bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detection and analysis of coherent structures in the near-field of a turbulent annular swirling jet: an unsteady Reynolds-averaged Navier–Stokes (URANS) simulation
Authors: Zhang Y , Vanierschot M 
Published: October 2019

Abstract
This paper analyses the capabilities of unsteady Reynolds-averaged Navier-Stokes (URANS) simulations to predict the coherent structures found in a swirling jet undergoing vortex breakdown. Recently, tomographic particle image velocimetry experiments of an annular swirling jet at a Reynolds number of 8500 at moderate swirl showed the presence of a double helical structure in the flow field (Vanierschot et al., Physical Review Fluids, 2018). This structure corresponds to the double helix vortex breakdown mode and is rarely observed in turbulent flows. In this study, the same flow topology is simulated using Computational Fluid Dynamics (CFD). Turbulence is modeled using the unsteady RANS methodology with a RNG k-e turbulence model. The coherent structures in the flow field were analysed using the spectral proper orthogonal decomposition technique. Despite the fact that it is known that steady-state RANS simulations using two-equation isotropic turbulence models have problems in accurately describing swirling flows which are highly anisotropic, this study shows that the unsteady variant was able to predict the large scale flow structures and their associated dynamics reasonable well. In particular, similar to the experiments, a double helical structure was found in the flow field. The structure has windings in the counter-swirl direction and it is wrapped around the central breakdown bubble. To the authors knowledge, this study is the first one to show the ability of unsteady RANS to predict not only the presence of the double helix vortex breakdown in the flow field, but also the spatial and temporal structure of it.
Effect of vibration frequency on settlement characteristic of reinforced embankment by geogrid with strengthened nodes using DEM simulation
Authors: Qiu C C , Lin Y L , Ma Y , He M , hong S J 
Published: October 2019

Abstract
Geogrid with strengthened nodes (GSN) is a new reinforcement system that is formed by attaching blocks of a certain thickness to the joints of the longitudinal and transverse ribs of an ordinary biaxial geogrid to form strengthened nodes. A series of discrete element method (DEM) simulations were performed to investigate the dynamic response of GSN-reinforced embankment at various vibration frequencies and compare the reinforcing effect of GSN with that of the ordinary geogrid. It was concluded that the settlement ratio of the loading platen at the top of the unreinforced and reinforced embankment decreases with the increase of the vibration frequency. As the frequency increases, the difference between the settlement ratios decreases, which is especially evident in the reinforced embankment. At the same frequency, GSN performs better in restricting the settlement ratio than the ordinary geogrid, and as the frequency increases, the reinforcing effects of both the ordinary geogrid and GSN decrease. The displacement fields of the simulated embankments were analyzed. It was found that the movement of soil particles below the loading platen is restricted due to the presence of the geogrid, resulting in less settlement of the loading platen and smaller lateral deformation of the embankment slope, compared with the unreinforced embankment. As for the GSN-reinforced embankment, the strengthened nodes provide resistance to soil particles, leading to a more effective reinforcing effect, so that the displacement vectors are even smaller.
Constraint conditional finite element method for off-axial interfacial sliding of fiber reinforced composite
Authors: Kitamura R 
Published: October 2019

Abstract
The main toughening mechanism of Ceramics Matrix Composite (CMC) is the fiber/matrix interfacial debonding and sliding. To simulate of the contact problem (such as interfacial sliding), penalty method etc have been used in general finite element method. But, these method need the repeated calculations, thus the CPU time is long and the accuracy depends on the number of repetitions. On the other hand, in actual CMCs, the fibers are not necessarily oriented along the loading direction, and the fiber diameter also fluctuates along the axis. Therefore, in this study, Constraint Conditional Finite Element Method (CC-FEM) was formulated to analyze the “off-axis interfacial sliding” with high precision and in a short time without repeated calculations. In CC-FEM, the equality of nodal displacements at the interface and the equilibrium of contact forces are assumed as constraint conditions, in which Coulomb's friction law and equivalent friction coefficient were taken into account. In addition, the validity was verified especially for “off-axis interfacial sliding” by comparing with general-purpose finite element software ANSYS. In the both cases of on- and off-axial interfacial sliding, the resultant stress distributions of the fiber and matrix agreed well with those of ANSYS. As compared to the case of on-axial interfacial sliding, the matrix stress recovered more steeply because of the higher equivalent frictional coefficient.
Analysis of boot rail collision resistance in rocket sled test system
Authors: Xiao J , Zhang WW , Xue Q , Gao W B , Zhang L R 
Published: October 2019

Abstract
The shoe-rail resistance to impact of rocket sled was analyzed. Shoe-rail friction resistance was backward calculated with speed, acceleration, weight and gap of shoe-rail. The influencing factor was gain by the continuous contact force model. The relation of shoe-rail resistance to impact with speed, weight and gap of shoe-rail was gained by means of data fitting. Based on the results, the collision resistance coefficient of a new type of sled is calculated. According to the resistance coefficient, the speed of sled is predicted. The predicted results are consistent with the dynamic experimental results.
Derivation of drag calculation model of rocket sled water brake
Authors: Xiao J , Zhang WW , Xue Q , Gao W B , Zhang L R 
Published: October 2019

Abstract
The calculation model of water resistance is derived by using fluid resistance theory. Using the water resistance calculation model, the braking distance calculation model is derived, and the braking distance of the two two-track sled vehicles is estimated. The pre-estimated water resistance, speed, and braking distance of the sled vehicle are in accordance with the actual external measurement results. The correctness of the water resistance calculation model is verified.
Simulation of thermal characteristics of lithium batteries for electric vehicles
Authors: Zhang L W , Yu Y S 
Published: October 2019

Abstract
To study the thermal characteristics of lithium batteries in electric vehicles, a single lithium ion battery under natural convection, forcedair cooling and water cooling conditions were simulated. On this basis, a parallel water-cooling model for battery pack is proposed, and CFD method was used to simulate and analyze the heat characteristics and temperature field distribution of the model at different flow rates, and an optimum flow rate of the cooling water was determined at which the battery pack has the best cooling result and thermal homogeneity corresponding to the given discharge rate.
Influence of bias voltage on structure and mechanical properties of TiCrN-Mo2N-Ni coatings
Authors: Chernogor A V , Blinkov I V , Belov D S , Volkhonskiy A O , Sergevnin V S 
Published: October 2019

Abstract
In this work, the influence of bias voltage on the structure, composition and physical properties of TiCrN-Mo2N-Ni arc Physical Vapor Deposition (arc-PVD) coatings were studied. Multilayer structure formed at all applied bias voltage due to planetary rotation of substrates. Thickness of sublayers range from 1 to 32 nm and defined by the plasma flow intensity from evaporators. Monte-Carlo calculation was used to study structure of prepared coatings. According to calculation and analysis of TEM images, sublayers composed by nitrides mixture. All coating characterized by high hardness, which correlated with residual stress of coatings.
Study on structural failure mechanism of explosive separation device based on the damage constitutive model
Authors: Wang J M , Zhang F , Qin Y L , Hong Y , Jin J F 
Published: October 2019

Abstract
The explosion separation device is the critical factor to ensure the effective separation of the payload and the launch vehicle. The rationality of the structural strength is usually assessed by the real explosion separation test. The separation of components in the deformation and damage is difficult to be obtained. The traditional method, based on the elasto-plastic constitutive, is also unable to simulate the damage of each component in the separation. The traditional strength check can be calculated by the elasto-plastic constitutive relation for large deformation, while the damage simulation can only be obtained by the progressive damage fracture. The metal material dynamic damage constitutive is applied based on the ABAQUES to simulate the damage and failure of the explosion separation. Then the finite element model of the explosion separation device can be established based on the elasto-plastic damage constitutive model, and the process of the ground test of the explosive separation device can be reproduced by the simulation of the corresponding FEM model. And then the weakness of the explosive separation device is finally determined by the calculation results. The experimental results are consistent with the simulation, which confirms the accuracy of the proposed method. The solution idea provides a reference basis for the product design and dynamic damage simulation.
Air compressor fault diagnosis based on lifting wavelet transform and probabilistic neural network
Authors: Yang W S , Su Y X , Chen Y P 
Published: October 2019

Abstract
Due to the wide variety of faults, the components of air compressor fault condition vibration signal are complex. Fault features extracted by conventional time-frequency analysis and multi-resolution analysis are not comprehensive enough to reflect the fault condition of air compressor. To overcome this deficiency, this paper proposes an air compressor fault diagnosis algorithm based on lifting wavelet. Firstly, the vibration signal of the air compressor is decomposed by lifting wavelet; then the statistic such as the peak value and Kurtosis of the decomposition layer is calculated as the fault features. Finally, Probabilistic Neural Network is utilized to classify the fault state. In the experiment, the fault extraction methods such as Wavelet Packet Decomposition and Continuous Wavelet Transform are compared. The results indicate that the fault features extracted by lifting wavelet are more comprehensively to reflect the fault condition of air compressor while other fault character extraction methods need more fault characteristics; the fault diagnosis accuracy by utilizing proposed method is high and the training time is short, which is more suitable for the online fault diagnosis of the actual air compressor.
Numerical simulation study on the effect of different mass flanges on strain growth of cylindrical shell
Authors: Han Y M , Gu W B , Hu Y H , Liu J Q , Wang Z 
Published: October 2019

Abstract
LS-DYNA software was used to establish the three-dimensional finite element simulation calculation model of cylindrical shell, and the effect of different mass flanges on the strain growth within the elastic response range of shell was analyzed and compared. The research found that: when the flange mass was changed, the radial and circumferential strain first peak value of shell basically did not change, while the axial first peak value changed greatly. The variation trend of strain growth response in radial direction and axial direction is basically the same, but the influence of axial strain growth is larger. Compared with the larger mass flange, the smaller mass flange may cause larger strain growth of the shell. Different flange mass only affects the time of strain growth and different frequency parts of excitation strain response, but hardly affects the appearance time of the "dangerous time domain". The longer the dangerous time domain is, the smaller the strain growth factor is.
Numerical study on the ideal interference of aircraft riveting joints
Authors: Sun S 
Published: October 2019

Abstract
The interference is the main parameter affecting the fatigue lifetime of the interference-fit joints. In this paper, the numerical simulation method of the interference-fit riveting process was studied for the object of the aluminium alloy joint commonly used in aircraft. On this basis, the influence of different interferences on the joint life was calculated and determined, which can provide a basis for determining the ideal riveting interference. The numerical simulation results show that the model built in this paper can well describe the whole forming process of the rivet including the overall upsetting and local upsetting. With the increase of the interference, the fatigue lifetime of the joint increases first and then decreases. For the joint structure given in this paper, when the interference is between 2.9% and 3.23%, a higher life increment can be obtained, which is basically consistent with the ideal interference obtained by experiments.
Effects of herringbone grooves on aerodynamic journal bearings based on finite element method
Authors: Gao S Y , Yang S , Shi Y G , Sun P , Chen H 
Published: October 2019

Abstract
Aerodynamic journal bearings are commonly used in high speed machines, which have weaknesses of low steady-state performance specifications. It is of great significance to study the effects of herringbone grooves on the characteristics of aerodynamic journal bearings. This paper investigates effects of herringbone grooves on functions of aerodynamic journal bearings by numerically solving the Reynolds equation based on improved finite element method. The obtained results show that the herringbone grooved aerodynamic journal bearings have a critical speed and they should run at a speed of greater than the critical speed. Ultra-high speeds and low eccentricity ratios are the suitable working conditions of the herringbone grooved aerodynamic journal bearings. The performance of aerodynamic journal bearings is enhanced with advancing groove numbers, and an optimal groove depth is existed with respect to the herringbone grooved aerodynamic journal bearing.
Sex, drugs, and rock ‘n’ roll
Authors: Nanay Bence 
Published: October 2019

Abstract
The experiences that would count as aesthetic in some sense are very diverse, and it is challenging to find something they have in common. ‘Sex, drugs, and rock ‘n’ roll’ considers four influential accounts of aesthetics—focusing on beauty, pleasure, emotion, and ‘valuing for its own sake’—to see just how difficult it is to keep the aesthetic and the non-aesthetic apart. These accounts contain some really important pointers to how we should and how we should not think about the domain of aesthetics. It is then argued that these accounts all point in the same direction, namely, that what is special about aesthetics is the way we exercise our attention in aesthetic experiences.
Aesthetics and the self
Authors: Nanay Bence 
Published: October 2019

Abstract
‘Aesthetics and the self’ explains how we take our aesthetic preferences to be a big part of who we are, but how these preferences change surprisingly quickly and often without us noticing. It compares aesthetic engagement or experience to aesthetic judgements. Making judgements is rarely rewarding, entertaining, or pleasurable. Experiences, on the other hand, can be. But why are aestheticians obsessed with aesthetic judgements? The key concept of ‘Western’ aesthetics has always been that of aesthetic judgement, whereas the vast majority of non-Western aesthetic traditions are not too concerned with aesthetic judgements at all, but with the way our emotions unfold, the way our perception is altered, and the way aesthetic engagement interacts with social engagement.
RNAactDrug: a comprehensive database of RNAs associated with drug sensitivity from multi-omics data
Authors: Dong Qun , Li Feng , Xu Yanjun , Xiao Jing , Xu Yingqi , Shang Desi , Zhang Chunlong , Yang Haixiu , Tian Zihan , Mi Kai , Li Xia , Zhang Yunpeng 
Published: October 2019

Abstract
Drug sensitivity has always been at the core of individualized cancer chemotherapy. However, we have been overwhelmed by large-scale pharmacogenomic data in the era of next-generation sequencing technology, which makes it increasingly challenging for researchers, especially those without bioinformatic experience, to perform data integration, exploration and analysis. To bridge this gap, we developed RNAactDrug, a comprehensive database of RNAs associated with drug sensitivity from multi-omics data, which allows users to explore drug sensitivity and RNA molecule associations directly. It provides association data between drug sensitivity and RNA molecules including mRNAs, long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) at four molecular levels (expression, copy number variation, mutation and methylation) from integrated analysis of three large-scale pharmacogenomic databases (GDSC, CellMiner and CCLE). RNAactDrug currently stores more than 4 924 200 associations of RNA molecules and drug sensitivity at four molecular levels covering more than 19 770 mRNAs, 11 119 lncRNAs, 438 miRNAs and 4155 drugs. A user-friendly interface enriched with various browsing sections augmented with advance search facility for querying the database is offered for users retrieving. RNAactDrug provides a comprehensive resource for RNA molecules acting in drug sensitivity, and it could be used to prioritize drug sensitivity–related RNA molecules, further promoting the identification of clinically actionable biomarkers in drug sensitivity and drug development more cost-efficiently by making this knowledge accessible to both basic researchers and clinical practitioners.
Database URL: http://bio-bigdata.hrbmu.edu.cn/RNAactDrug.
At the end of the line: on kairological history
Authors: Holmes Brooke 
Published: October 2019

AbstractThis essay examines, from a position within Classics, different angles on critiques of historicism and the turn to anachronism in History, Art History, Medieval Studies, and Queer Theory before proposing the idea of ‘kairological history’, on the model of the artist Paul Chan’s ‘kairological art’. On this analysis, ‘kairological history’ engages the critical and creative resources of anachronic thinking alongside tools of historicism (e.g. empiricism, successionism, periodization, alterity) in making choices about ‘telling time’. These choices reflect a critical understanding of how temporality shapes the valuation of the past, particularly in relation to a ‘classical’ past; the negotiation of identity and difference between past and present; and the kinds of communities that history aims to support. The second half of the essay examines two instances of anachronism within the history of anatomy, one from Galen and one from the early twenty-first century. Both cases represent problems that historicism can correct. But the modality of correction, in itself, is anaemic and risks the very teleology that linear history is so often faulted for. The essay therefore explores what gets lost and what gets found when temporality is aligned with linearity, as well as non-linear modes of telling time.
The Hidden Cost of Flexibility: A Factorial Survey Experiment on Job Promotion
Authors: Fernandez-Lozano Irina , González M José , Jurado-Guerrero Teresa , Martínez-Pastor Juan-Ignacio 
Published: October 2019

Abstract
This article analyses the role of gender, parenthood, and work flexibility measures and the mediating role of stereotypes on the likelihood of achieving an internal promotion in Spain. We hypothesize that employers favour fathers over mothers and disfavour flexible workers (flexibility stigma) because they are perceived, respectively, as less competent and less committed. We also hypothesize that employers reflect their gender values in the selection process. These hypotheses are tested using data from a survey experiment in which 71 supervisors from private companies evaluate 426 short vignettes describing six different candidates for promotion into positions that require decision-making and team supervision skills. Several candidate characteristics are experimentally manipulated, while others such as skills and experience in the company are kept constant to minimize the risk of statistical discrimination. Contrary to our expectations, fathers are not preferred in promotion, as they are not perceived as being more competent than mothers. However, we find that flexibility leads to lower promotion scores, partly due to its association with a lack of commitment. Although the statutory right to reduce working hours for care reasons seems a major social achievement, this experiment shows that mothers may be indirectly penalized, as they are the main users of this policy.
Black–White Disparities in Moves to Assisted Living and Nursing Homes Among Older Medicare Beneficiaries
Authors: Jenkins Morales Meghan , Robert Stephanie A 
Published: October 2019

Abstract

Objectives
Investigate black-white disparities in older adults’ moves to assisted living and nursing homes and draw from the Andersen Healthcare Utilization Model to test explanations for any disparities.

Methods
Data are from a nationally representative sample of older community-dwelling Medicare beneficiaries from the 2015 (N = 5,212) National Health and Aging Trends Study (NHATS). We use stepwise multinomial logistic regression to examine black-white disparities in moves out of community housing to assisted living or a nursing home over 2 years, before and after adjusting for predisposing (age, gender), enabling (income, housing tenure, Medicaid, living arrangement) and need (activities of daily living [ADL] limitation, physical capacity, self-rated health, and dementia) factors.

Results
Black older adults are less likely to move to assisted living and are more likely to move to a nursing home compared to white older adults. Black-white disparities in moves to nursing homes are explained by black-white differences in enabling and need factors, whereas black-white disparities in moves to assisted living remain even after adjusting for enabling and need factors.

Discussion
Unmeasured factors related to systemic racism (e.g., residential racial segregation, racial discrimination) and/or black-white differences in care preferences might further explain black-white disparities in moves to assisted living and warrant further investigation.
Strategic technology adoption and entry deterrence in broadband
Authors: Skiti Tedi 
Published: October 2019

AbstractIn this article, we examine the role of strategic investment in the US broadband industry. In particular, we provide evidence that cable incumbents adjust their investment strategy in response to fiber entry threat and that these deterrence strategies have been successful particularly in intermediate sized markets. We compile data on broadband deployment and exogenous franchise agreements for potential fiber entrants at the most local level in New York State. The results indicate that strategic cable investment may negatively affect optical fiber diffusion.