bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical Simulation on Combustor of Impinging Stream Vortex Engine (ISVE)
Authors: Yu Xiaojing , Liu Yang , Pei Jingqiu 
Published: August 2019

Abstract
The impinging stream vortex engine (ISVE), with the advantages of strong thermal protection performance, low cost and simple structure, emerges as the times require. In this paper, the propellant mixing performance, atomization performance, combustion performance and thermal protection performance under different working conditions are calculated and analyzed by numerical simulation for the designed impinging swirl cooling thrust chamber, and the influence of thrust chamber structure on its flow and combustion performance is discussed. The results show that the wall temperature of the thrust chamber is lower than 400K, and the combustion efficiency reaches 93%. The double eddy current structure will strengthen the combustion reaction and make the top temperature of the thrust chamber too high, which will provide theoretical guidance for the next structural design of the thrust chamber.
Effect of grid and time step for predicting hydrodynamic resistance of blunt body
Authors: Wang Lili , Sun Kangning , Cai Yufeng , Jiao Jun , Zhang Jiaxu , Wang Mingzhen , Han Xiaohong , Xu Yongze 
Published: August 2019

Abstract
Taking the amphibious vehicle as an example, the hydrodynamic resistance was obtained by using computational fluid dynamics (CFD). This paper investigated the influent factors which contain mesh generation and time step which influences hydrodynamic calculation, and compared the calculation results with the relevant experimental results. This paper analyzed three factors which affecting amphibious vehicle’s resistance calculation, including the first grid thickness of boundary layer and ratio for extending surface mesh to the computational domain. By means of analyzing different factors, a high calculation precision strategy which could serve as reference for amphibious vehicle’s hydrodynamic resistance was obtained.
Numerical Simulation of Oxygen-Enriched Combustion of Low-Quality Coal in Cement Rotary Kiln
Authors: Li Song , Wang Jingfu 
Published: August 2019

Abstract
On the basis of the original four-channel burner, the oxygen-enriched channel is added to control the oxygen-enriched rate by adjusting the opening of the valve at the entrance of the oxygen-enriched channel. In actual production, the oxygen concentration in rotary kiln can be adjusted more flexibly to meet the combustion needs of different coal types in kiln and realize oxygen-enriched combustion under different oxygen concentration. A physical model of rotary kiln--burner is established in this paper, using FLUENT to increase the oxygen - channel rotary kiln burner structure for numerical simulation of combustion of pulverized coal. The distribution of velocity field, combustion temperature and component concentration field in kiln were analyzed, and the combustion characteristics of pulverized coal in kiln were compared between two kinds of burners. The calculation results show that the addition of oxygen-enriched channels will not cause significant changes in the velocity field in the rotary kiln, and can promote the combustion of pulverized coal in the rotary kiln, thus verifying the feasibility of adding oxygen-enriched channels.
Study on Heat Conduction Characteristics of Heat Insulation Wall Based on Airflow Reverse Osmosis Principle
Authors: Cao Dingyu , Fu Lequn , Lin Chuangting 
Published: August 2019

Abstract
Building energy saving is an important theme in the development of construction industry. It has important significance to achieve wall heat insulation. MATLAB software was utilized to model the heat transfer coefficient and obtain the main factors influencing airflow reverse osmosis principle based on the research of airflow reverse osmosis principle. The influence of seepage layer thickness and seepage velocity on thermal performance of airflow reverse seepage principle was determined and the optimal value was obtained through ANSYS simulation. An energy-saving plate was designed to build a removable house, and the heat conduction characteristics of air reverse osmosis principle were verified by experiments. The simulation results showed that heat conduction characteristics of the heat insulation wall based on airflow reverse osmosis principle were optimal when the thickness of the seepage layer is 40mm and the seepage velocity is 0.008m/s. The experimental results showed that the heat-shielding performance of the wall based on the airflow reverse osmosis principle was improved by 18.56%, and the thermal insulation performance was improved by 24.15% compared with that of the ordinary wall, and heat insulation wall based on airflow reverse osmosis principle had excellent heat conduction characteristics.
Numerical Simulation and Analysis of the dynamic Behaviours on the Spring-loaded Pressure Relief Valve
Authors: Gan Lifeng , Yu Xinhai 
Published: August 2019

Abstract
In this paper, in engineering practice, the computational fluid dynamics method was adopted to study the dynamic characteristics of the spring-loaded pressure relief valve. The effects of different parameters on the dynamic performance were investigated by CFD simulation. In the simulation, the damping coefficient has little influence on the discharge time and reseating pressure of the relief valve. With the decrease of spring stiffness, the reseating time of pressure relief valve increases, and reducing the spring stiffness can effectively reduce the reseating pressure. The reseating pressure decreases with the rise in the distance between the upper adjusting ring and the sealing face. This simulation results can provide a reference for the design and optimization of the structural parameters of the spring-loaded pressure relief valve.
Fluid-Structure Coupling Analysis of Non-linear Reciprocating Piston Seals in Series
Authors: Zhang Shouyuan 
Published: August 2019

Abstract
The reciprocating piston seals are crucial parts in hydraulic system which are widely used in aerospace and military industry. A direct fluid-structure coupling method with high efficiency is proposed for solving the transient Elaso-Hydrodynamic-Lubrication (EHL) problem in hydropneumatic suspension reciprocating piston seal system. Detailed 3D fluid-structure coupling model is built using finite element discretization. Material tests are carried out to obtain the parameters of the 3rd-oder Ogden constitutive model of the rubber O-ring. The sealing performance and friction force of the sealing system are analyzed in different piston speed. The critical speed from mixed lubrication to full film lubrication is obtained.
The application of numerical calculation method in determining the coefficient of S-type Pitot tube
Authors: Li Haiyang , Zhang Liang , Yao Xinhong , Zhang Jinming 
Published: August 2019

Abstract
In this paper, the coefficient of S-type Pitot tube is obtained by using numerical calculation method with the help of the computational fluid dynamics (CFD) software. The process includes designing the three-dimensional geometric models of the S-type Pitot tube being calibrated and the low speed wind tunnel used in calibrating the Pitot, meshing the 3D geometric model, setting calculation model and boundary conditions, solving mesh by using hydrodynamic equations, and obtaining the coefficient of the Pitot tube by post-processing of the calculation results. However, in order to verify the validity of the method, a real flow test of calibrating the K coefficient of S-type Pitot tube was carried out in a low speed wind tunnel. The result shows that all the Pitot tube coefficients at different velocity points have errors of less than 1.5% except for the minimum flow velocity point, which indicates the effectiveness of the numerical method.
Numerical simulation of the churning losses in vehicle rear axle hypoid gear
Authors: Huang Fengyun , Liu Weiteng , Zou Lin , Xu Jinli 
Published: August 2019

Abstract
A simplified 3D flow field numerical model of rear axle including passive bevel gear and the differential housing is established, based on the VOF (Volume of Fluid) model and the RNG k-ε turbulence model. With the model, the transient oil flow distribution and the influence law of speed, viccosity and bolt structure on the velocity field and the power losses is obtained. In general, the churning power losses increases with the rotational speed and viscosity while the rotational speed has more impact than viscosity on the power losses. The fluid region and the flow velocity increases with the rotational speed and the bolt structure causes a high speed area with the larger velocity gradient in the backflow surface of the bolts, implying the bolts can generate additional churning torque.
Network Analysis of Patenting Trends in Energy Efficiency
Authors: Bogomolova A , Balk I , Semenov E , Ivaschenko N 
Published: August 2019

Abstract
One of the most important topics of sustainability research and applications is reaching energy efficiency. In this paper we analysed more than 100,000 of patents related to different aspects of energy efficiency with the issue dates from 1973 to 2019. In the paper we will discuss how network theory can be applied to discover technology trends and apply them to improve sustainability efforts making more educated decision. This paper will demonstrate how patenting trends change with time and how different topics influence each other.
Elaboration of an Algorithm for the Efficient Use of Municipal Solid Waste Landfills
Authors: Rumyantseva A , Berezyuk M , Plastinina I , Rumyantseva E 
Published: August 2019

Abstract
The annual increase in generation and disposal of production and consumer wastes presents an ever pressing environmental, economic, and social challenge for modern industrially developed urbanized territories. As part of the waste management reform, an important issue is the restoration of old landfills for municipal solid waste (MSW). One of possible engineering solutions for the implementation of projects for the reburial of waste from old landfills is excavation of the landfill body with further sorting and extraction of landfill soil and, in some cases, recycled materials. This will reduce the amount of waste subject to reburial. The article examines several options for the implementation of the projects of old landfill restoration. It offers an algorithm for the efficient use of MSW landfills based on the data of environmental and economic analysis of some waste landfill restoration projects.
NaBaR(BO3)2 (R = Dy, Ho, Er and Tm): structurally perfect triangular lattice materials with two rare earth layers
Authors: Guo Shu , Kong Tai , Cava R J 
Published: August 2019

Abstract
We report the crystal growth of NaBaR(BO3)2 (R = Dy, Ho, Er and Tm) by the flux method. In the rhombohedral crystal structures, [RO6] octahedra and planar [BO3] units connect by bridging O atoms, forming triangular layers in the ab plane that are evenly spaced along c. Two perfectly triangular rare earth layers of identical dimension are found. Anisotropic magnetic susceptibility is observed for all; NaBaEr(BO3)2 is nearly isotropic while NaBaTm(BO3)2 is the most anisotropic. Heat capacity measurements reveal no long-range magnetic ordering down to 0.35 K for R = Dy or Er, while the Ho material displays a significant entropy loss. All the magnetic entropy appears to be absent in the Tm case by low temperature, suggesting that a singlet ground state may have formed.
Minimizing Risk and Maximizing Spatial Transferability: Challenges in Constructing a Useful Model of Potential Suitability for an Invasive Insect
Authors: Morey Amy C , Venette Robert C 
Published: August 2019

AbstractForecasting the spread and potential impacts of invasive, alien species is vital to relevant management and policy decisions. Models that estimate areas of potential suitability are useful to guide early detection and eradication, inform effective budget allocations, and justify quarantine regulations. Machine-learning is a rapidly emerging technology with myriad applications, including the analysis of factors that govern species’ distributions. However, forecasts for invasive species often require extrapolation into novel spaces, which may severely erode model reliability. Using the popular machine-learning platform, MaxEnt, we integrate numerous tools and recommendations to demonstrate a method of rigorous model development that emphasizes assessment of model transferability. Our models use Lymantria dispar dispar (L.) (Lepidoptera: Erebidae), an insect brought to the United States in the late 1860s from Europe and subsequently well monitored in spread. Recent genetic analyses provide evidence that the eastern North American population originated in Germany, France, and northern Italy. We demonstrate that models built and assessed using typical methodology for invasive species (e.g., using records from the full native geographic range) showed the smallest extent of extrapolation, but the worst transferability when validated with independent data. Conversely, models based on the purported genetic source of the eastern North American populations (i.e., a subset of the native range) showed the greatest transferability, but the largest extent of extrapolation. Overall, the model that yielded high transferability to North America and low extrapolation was built following current recommendations of spatial thinning and parameter optimization with records from both the genetic source in Europe and early North American invasion.
Klotho, the elusive kidney-derived anti-ageing factor
Authors: Sanchez-Niño Maria Dolores , Fernandez-Fernandez Beatriz , Ortiz Alberto 
Published: August 2019

AbstractChronic kidney disease (CKD) is one of the fastest growing causes of death worldwide. Only early diagnosis will allow prevention of both CKD progression and the negative impact of CKD on all-cause and cardiovascular mortality. Klotho is a protein produced by the kidneys that has anti-ageing and phosphaturic properties, preventing excess positive phosphate balance. There is evidence that Klotho downregulation is one of the earliest consequences of kidney injury. Thus the development of reliable assays to monitor Klotho levels may allow an early diagnosis of CKD and monitoring the impact of therapies aimed at preserving Klotho expression or at preventing CKD progression. However, the performance of Klotho assays has been suboptimal so far. In this issue of Clinical Kidney Journal, Neyra et al. explore methods to improve the reliability of Klotho assays.
Digging the topology of rock art in northwestern Patagonia
Authors: Vargas Fernando E , Lanata José L , Abramson Guillermo , Kuperman Marcelo N , Fiore Danae 
Published: August 2019

AbstractWe present a study on the rock art of northern Patagonia based on network analysis and communities detection. We unveil a significant aggregation of archaeological sites, linked by common rock art motifs that turn out to be consistent with their geographical distribution and archaeological background of hunter-gatherer stages of regional peopling and land use. This exploratory study will allow us to approach more accurately some social strategies of visual communication entailed by rock art motif distribution, in space and time.
Tricuspid regurgitation and long-term clinical outcomes
Authors: Chorin Ehud , Rozenbaum Zach , Topilsky Yan , Konigstein Maayan , Ziv-Baran Tomer , Richert Eyal , Keren Gad , Banai Shmuel 
Published: August 2019

AbstractAimsTricuspid regurgitation (TR) is a frequent echocardiographic finding; however, its effect on outcome is unclear. The objectives of current study were to evaluate the impact of TR severity on heart failure hospitalization and mortality.Methods and resultsWe retrospectively reviewed consecutive echocardiograms performed between 2011 and 2016 at the Tel-Aviv Medical Center. TR severity was determined using semi-quantitative approach including colour jet area, vena contracta width, density of continuous Doppler jet, hepatic vein flow pattern, trans-tricuspid inflow pattern, annular diameter, right ventricle, and right atrial size. Major comorbidities, re-admissions and all-cause mortality were extracted from the electronic health records. The final analysis included 33 305 patients with median follow-up period of 3.34 years (interquartile range 2.11–4.54). TR (≥mild) was present in 31% of our cohort. One-year mortality rates were 7.7% for patients with no/trivial TR, 16.8% for patients with mild TR, 29.5% for moderate TR, and 45.6% for patients with severe TR (P < 0.001). Univariate and multivariate analyses demonstrated a positive correlation between TR severity and overall mortality and rates of heart failure re-admission after adjustment for potential confounders. The proportional hazards method for overall mortality showed that patients with moderate [hazard ratio (HR) 1.15, 95% confidence interval (CI) 1.02–1.3, P = 0.024] and severe TR (HR 1.43, 95% CI 1.08–1.88, P = 0.011) had a worse prognosis than those with no or minimal TR.ConclusionsThe presence of any degree of TR is associated with adverse clinical outcome. At least moderate TR is independently associated with increased mortality.
Long-term survival following on-pump and off-pump coronary artery bypass graft surgery: a propensity score-matched analysis
Authors: Kirmani Bilal H , Guo Hui , Ahmadyur Omaid , Bittar Mohamad N 
Published: August 2019

AbstractOBJECTIVESRecent studies have once again brought into focus the long-term survival following off-pump coronary artery bypass grafting (OPCAB) compared with conventional on-pump coronary artery bypass grafting surgery (ONCAB). The aim of this study was to compare the long-term risk-adjusted survival rates in patients undergoing coronary artery bypass grafting (CABG) using these 2 techniques.METHODSWe undertook a propensity score-matched analysis of 10 293 patients who underwent CABG at our single institution between 2000 and 2016. A logistic regression model was fitted using 14 covariates and their 2-way interactions to calculate an estimated propensity score [area under curve (AUC) 0.69], from which 1:1 nearest neighbour matching was performed. Patient survival was assessed using the Kaplan–Meier method and log-rank test.RESULTSOf the total cohort, 8319 patients had ONCAB and 1974 had OPCAB. Prior to matching, the OPCAB group had marginally higher EuroSCORE [3.7 ± 2.7 vs 3.5 ± 3, median (interquartile range) 3 (2–5) vs 3 (2–5), P = 0.016] and significantly lower average number of grafts per patient (2.39 ± 0.72 vs 2.75 ± 0.48, P < 0.001). Post-matching distributions between OPCAB and ONCAB showed a substantial improvement in balance in preoperative patient characteristics. The 2 surgery groups differed significantly in survival (P < 0.001). OPCAB demonstrated improved long-term survival at 10 years [84.8%, 95% confidence interval (CI) (82.7–86.9%) vs 75.8%, 95% CI (73.4–78.2%)] and 15 years [65.4%, 95% CI (61.4–69.6%) vs 58.5%, 95% CI (54.9–62.3%)]. Results of sensitivity analysis for 1:2 and 1:3 matched data were in concordance with these findings of survival.CONCLUSIONAt our institution, selected patients who underwent OPCAB had lower in-hospital morbidity and improved long-term survival when compared with a matched population of ONCAB patients.
Plastome Reduction in the Only Parasitic Gymnosperm Parasitaxus Is Due to Losses of Photosynthesis but Not Housekeeping Genes and Apparently Involves the Secondary Gain of a Large Inverted Repeat
Authors: Qu Xiao-Jian , Fan Shou-Jin , Wicke Susann , Yi Ting-Shuang 
Published: August 2019

Abstract
Plastid genomes (plastomes) of parasitic plants undergo dramatic reductions as the need for photosynthesis relaxes. Here, we report the plastome of the only known heterotrophic gymnosperm Parasitaxus usta (Podocarpaceae). With 68 unique genes, of which 33 encode proteins, 31 tRNAs, and four rRNAs in a plastome of 85.3-kb length, Parasitaxus has both the smallest and the functionally least capable plastid genome of gymnosperms. Although the heterotroph retains chlorophyll, all genes for photosynthesis are physically or functionally lost, making photosynthetic energy gain impossible. The pseudogenization of the three plastome-encoded light-independent chlorophyll biosynthesis genes chlB, chlL, and chlN implies that Parasitaxus relies on either only the light-dependent chlorophyll biosynthesis pathway or another regulation system. Nesting within a group of gymnosperms known for the absence of the large inverted repeat regions (IRs), another unusual feature of the Parasitaxus plastome is the existence of a 9,256-bp long IR. Its short length and a gene composition that completely differs from those of IR-containing gymnosperms together suggest a regain of this critical, plastome structure-stabilizing feature. In sum, our findings highlight the particular path of lifestyle-associated reductive plastome evolution, where structural features might provide additional cues of a continued selection for plastome maintenance.
Age Differences in Negative, but Not Positive, Rumination
Authors: Emery Lisa , Sorrell Anne , Miles Cassidy 
Published: August 2019

Abstract

Objectives
The main objective of this study was to determine whether there are age differences in positive and negative repetitive thought (ie, rumination).

Method
Young adults (ages 19–39; n = 114) and older adults (ages 60–85; n = 88) completed measures of negative and positive rumination. Bayesian analyses were used to determine whether age differences were present for both negative (young &gt; old) and positive (old &gt; young) rumination.

Results
There was extremely strong evidence for age differences in negative rumination, with lower scores in older adults. In contrast, the evidence was in favor of the null hypothesis for positive rumination.

Discussion
Age-related positivity is better characterized as decreased dwelling on the meaning of negative moods, rather than increased attention to positive ones.
Aberrant mitochondrial function in patient-derived neural cells from CDKL5 deficiency disorder and Rett syndrome
Authors: Jagtap Smita , Thanos Jessica M , Fu Ting , Wang Jennifer , Lalonde Jasmin , Dial Thomas O , Feiglin Ariel , Chen Jeffrey , Kohane Isaac , Lee Jeannie T , Sheridan Steven D , Perlis Roy H 
Published: August 2019

Abstract
The X-linked neurodevelopmental diseases CDKL5 deficiency disorder (CDD) and Rett syndrome (RTT) are associated with intellectual disability, infantile spasms and seizures. Although mitochondrial dysfunction has been suggested in RTT, less is understood about mitochondrial function in CDD. A comparison of bioenergetics and mitochondrial function between isogenic wild-type and mutant neural progenitor cell (NPC) lines revealed increased oxygen consumption in CDD mutant lines, which is associated with altered mitochondrial function and structure. Transcriptomic analysis revealed differential expression of genes related to mitochondrial and REDOX function in NPCs expressing the mutant CDKL5. Furthermore, a similar increase in oxygen consumption specific to RTT patient–derived isogenic mutant NPCs was observed, though the pattern of mitochondrial functional alterations was distinct from CDKL5 mutant–expressing NPCs. We propose that aberrant neural bioenergetics is a common feature between CDD and RTT disorders. The observed changes in oxidative stress and mitochondrial function may facilitate the development of therapeutic agents for CDD and related disorders.