bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical Investigations of Leakage Performance Degradations in Labyrinth and Flexible Seals Due to Wear
Authors: Dai Xinbo , Yan Xin , He Kun , Li Jun , Feng Zhenping 
Published: November 2020

Abstract
The finite element analysis (FEA) and computational fluid dynamics (CFD) methods are utilized to investigate the leakage performance degradations in two kinds of flexible seals (i.e., forward bending and backward bending) and two kinds of shroud labyrinth seals (i.e., with straight fins and chamfered fins) in rubbing events. With the existing experimental data, FEA methods for contacting simulations and CFD methods for leakage rate and flow pattern predictions are carefully examined. The wear characteristic and leakage performance between labyrinth seals and flexible seals are compared before and after rub. The results show that, in rubbing process, the labyrinth seal with straight (symmetrical) fins is likely to undergo the mushrooming damage, whereas the labyrinth seal with chamfered (asymmetrical) fins is likely to undergo the tooth-bending damage. In rubbing process, compared with the labyrinth seal, the flexible seal has a superior characteristic in resisting the wear damage due to increased flexibility of fin. For a labyrinth seal with 0.3 mm design clearance and a flexible seal with 0.15 mm design clearance, the 0.5 mm radial displacement of rotor will result in 110% increase of leakage rate for labyrinth seal, and 7% increase of leakage rate for flexible seal after wear. Under the same conditions, the forward bending flexible seal has a lower leakage rate than the backward bending flexible seal before and after rub.
Inversion-Based and Optimal Feedforward Control for Population Dynamics With Input Constraints and Self-Competition in Chemostat Reactor Applications
Authors: Kurth Anna-Carina , Schmidt Kevin , Sawodny Oliver 
Published: November 2020

AbstractThrough chemostat reactors, organisms can be observed under laboratory conditions. Hereby, the reactor contains the biomass, whose growth can be controlled via the dilution rate, respectively, the speed of a pump. Due to physical limitations, input constraints need to be considered. The population density in the reactor can be described by a hyperbolic nonlinear integro partial differential equation (IPDE) of first order. The steady-states and generalized eigenvalues and eigenmodes of these IPDE are determined. In order to track a desired reference trajectory, an optimal and an inversion-based feedforward control are designed. For the optimal feedforward control, the singular arc of the control is calculated and a switching strategy is stated, which explicitly considers the input constraints. For the inversion-based feedforward control, the IPDE is first linearized around the steady-state. To comply with the input constraints, a control system simulator is designed. For the simulation model, the IPDE is approximated using Galerkin's method. Simulations show the functionality of the designed controls and provide the basis for comparison. The inversion-based feedforward control operates well near the steady-state, whereas the performance of the optimal feedforward control is not bounded to the proximity to the steady-state.
Field Performances, Effective Times, and Economic Assessments of Polymer Gel Treatments in Controlling Excessive Water Production From Mature Oil Fields
Authors: Aldhaheri Munqith , Wei Mingzhen , Alhuraishawy Ali , Bai Baojun 
Published: November 2020

AbstractPolymer bulk gels have been widely applied to mitigate excessive water production from mature oil fields by correcting the reservoir permeability heterogeneity. This paper reviews water responses, effective times, and economic assessments of injection-well gel treatments based on 61 field projects. Eight parameters were evaluated per the reservoir type using the descriptive analysis, stacked histograms, and scatterplots. Results show that water production generally continues to increase after the treatment for undeveloped conformance problems. Contrarily, it typically decreases after the reactive gel treatments target developed conformance issues. For the developed problems, gel treatments do not always mitigate the water production where the water cut may stabilize or increase by 17% in 22% of instances. In addition, they often do reduce water production but not dramatically to really low levels where the water cut stays above 70% and reduces by only 10% in most cases. Gel treatments are economically appraised based only on the oil production response, and both water responses (injection and production) are not considered in the evaluation. They have a typical payout time of 9.2 months, cost of incremental oil barrel of 2 $/barrel, and effective time of 1.9 years. In addition, they have better water responses and economics in carbonates than in sandstones and in unconsolidated and naturally fractured reservoirs than in matrix-rock formations. The current review strongly warns reservoir engineers that gel treatments are not superior in alleviating the water production and candidates should be nominated based on this fact to achieve favorable economics and avoid treatment failures.
Interaction of Void Spacing and Material Size Effect on Inter-Void Flow Localization
Authors: Holte Ingrid , Srivastava Ankit , Martínez-Pañeda Emilio , Niordson Christian F. , Nielsen Kim L. 
Published: November 2020

Abstract
The ductile fracture process in porous metals due to growth and coalescence of micron scale voids is affected not only by the imposed stress state but also by the distribution of the voids and the material size effect. The objective of this study is to understand the interaction of the inter-void spacing (or ligaments) and the resultant gradient-induced material size effect on void coalescence for a range of imposed stress states. To this end, three-dimensional finite element calculations of unit cell models with a discrete void embedded in a strain gradient-enhanced material matrix are performed. The calculations are carried out for a range of initial inter-void ligament sizes and imposed stress states characterized by fixed values of the stress triaxiality and the Lode parameter. Our results show that in the absence of strain gradient effects on the material response, decreasing the inter-void ligament size results in an increase in the propensity for void coalescence. However, in a strain gradient-enhanced material matrix, the strain gradients harden the material in the inter-void ligament and decrease the effect of inter-void ligament size on the propensity for void coalescence.
Real-Time Analysis of the Dynamic Foot Function: A Machine Learning and Finite Element Approach
Authors: Tarrade Tristan , Dakhil Nawfal , Behr Michel , Salin Dorian , Llari Maxime 
Published: November 2020

Abstract
Finite element analysis (FEA) has been widely used to study foot biomechanics and pathological functions or effects of therapeutic solutions. However, development and analysis of such foot modeling is complex and time-consuming. The purpose of this study was therefore to propose a method coupling a FE foot model with a model order reduction (MOR) technique to provide real-time analysis of the dynamic foot function. A generic and parametric FE foot model was developed and dynamically validated during stance phase of gait. Based on a design of experiment of 30 FE simulations including four parameters related to foot function, the MOR method was employed to create a prediction model of the center of pressure (COP) path that was validated with four more random simulations. The four predicted COP paths were obtained with a 3% root-mean-square-error (RMSE) in less than 1 s. The time-dependent analysis demonstrated that the subtalar joint position and the midtarsal joint laxity are the most influential factors on the foot functions. These results provide additionally insight into the use of MOR technique to significantly improve speed and power of the FE analysis of the foot function and may support the development of real-time decision support tools based on this method.
Pressure Drop Oscillations With Symmetry Breakdown in Two-Phase Flow Parallel Channels
Authors: Rahman Md Emadur , Singh Suneet 
Published: November 2020

Abstract
Two-phase flow in parallel heated channels is prone to symmetry breakdown resulting in mass flow maldistribution. Moreover, in the presence of compressible volume (CV), such systems also undergo pressure drop oscillations (PDOs). The performances of such systems depend on the effect of these flow instabilities. However, the simultaneous occurrence of these two-phenomena has been rarely reported in the literature. In this work, an approach is applied in a two-channel system to demarcate the parameter space of mass flow rate and inlet temperature into several areas, where these two phenomena take place. The loss in the symmetry in the flow rate is observed as the mass flow rate is varied, which leads to flow maldistribution. The PDO are also observed for specific values of mass flow rate in the system. One unique feature of the parallel channel system is the existence of the oscillatory and stable (albeit asymmetric) states at the same parameter values. For these parameter values, the final state of the system is dependent on the type of initial disturbance. The flow maldistribution due to symmetry breakdown is identified by the pitchfork bifurcation, and oscillations of mass flow rate are identified by the presence of Hopf bifurcation. Moreover, the physical interpretation of the different phenomena in the system is carried out using internal and external pressure drop characteristics curves.
Coupling Effect of State-of-Charge and Strain Rate on the Mechanical Behavior of Electrodes of 21700 Lithium-Ion Battery
Authors: Sonwane Aditya , Yuan Chunhao , Xu Jun 
Published: November 2020

Abstract
As an emerging type of high-density lithium-ion batteries (LIBs) for electric vehicles, 21700 cylindrical batteries may suffer inevitable mechanical vibrations, curbstone impact/penetration, and crash accidents, which probably induce internal short circuit (ISC), thermal runaway, and more catastrophic events such as fire/explosion. Therefore, exploring the mechanical behavior quantitively serves as a cornerstone for a better understanding of the safety behaviors of batteries. This paper focuses on the characterization of the tensile mechanical behavior of the electrodes under different state-of-charges (SOCs) coupled with strain rate effect. In the meantime, a numerical computation model is also established to provide a fundamental understanding of the electrode deformation. We discover that both anodes and cathodes are highly anisotropic at various electrochemical statuses, and strong strain rate dependency can be observed. Results provide an in-depth and systematic characterization of the mechanical behaviors of the electrodes and a powerful tool for the future design, evaluation, and manufacturing of safer batteries.
The inter-relationship between depressed mood, functional decline and disability over a 10-year observational period within the Longitudinal Urban Cohort Ageing Study (LUCAS)
Authors: Dapp Ulrike , Minder Christoph E , Golgert Stefan , Klugmann Björn , Neumann Lilli , von Renteln-Kruse Wolfgang 
Published: November 2020

BackgroundThe WHO defines ‘healthy ageing’ as ‘the process of developing and maintaining the functional ability’. Late-life depression and frailty compromise well-being and independence of older people. To date, there exists little research on the interaction of the dynamic processes of frailty and depression and only a few studies were longitudinal. Conclusions about the direction of effects remained uncertain.MethodsData were obtained from each of the last six biyearly waves (2007–2017) of the Longitudinal Urban Cohort Ageing Study (LUCAS) in Hamburg, Germany, a prospective observational cohort study of manifold aspects of ageing. Screening of predictor and event variables: depressed mood: one question from the 5-item Mental Health Inventory Screening Test; frailty: LUCAS Functional Ability Index, status ‘frail’; disability: one question on need for human help with basic activities of daily living. Kaplan-Meier curves and Cox’s proportional hazards regression were used for time-to-event analyses with shifting baseline.ResultsSample size in 2007 was 2012, average age 76.2 years; ±6.5. Main results were as follows: (1) depression significantly increased the hazard of subsequent frailty (HR=1.581; 95% CI 1.257 to 1.988; p<0.001); (2) frailty significantly increased the hazard of subsequent depression (HR=2.324; 95% CI 1.703 to 3.172; p<0.001); (3) depression significantly increased the hazard of subsequent disability (HR=2.589; 95% CI 1.885 to 3.557; p<0.001) and (4) disability did not significantly increase the hazard of subsequent depression (HR=1.540; 95% CI 0.917 to 2.579; p=0.102).ConclusionOur results suggest an interdependence of the processes of depression and frailty/disability rather than unidirectional dependencies. These observable processes may be representative of underlying unobservable profound life changes. Obviously, there is a need for early screening to initiate appropriate interventions.
Household and area-level social determinants of multimorbidity: a systematic review
Authors: Ingram Elizabeth , Ledden Sarah , Beardon Sarah , Gomes Manuel , Hogarth Sue , McDonald Helen , Osborn David P , Sheringham Jessica 
Published: November 2020

BackgroundNo clear synthesis of evidence examining household and area-level social determinants of multimorbidity exists. This study aimed to systematically review the existing literature on associations between household and area-level social determinants of health (SDoH) and multimorbidity prevalence or incidence in the general population.MethodsSix databases (MedLine, EMBASE, PsychINFO, Web of Science, CINAHL Plus and Scopus) were searched. The search was limited to peer-reviewed studies conducted in high-income countries and published in English between 2010 and 2019. A second reviewer screened all titles with abstracts and a subset of full texts. Study quality was assessed and protocol pre-registered (CRD42019135281).Results41 studies spanning North America, Europe and Australasia were included. Household income and area-level deprivation were the most explored with fairly consistent findings. The odds of multimorbidity were up to 4.4 times higher for participants with the lowest level of income compared with the highest level. Those living in the most deprived areas had the highest prevalence or incidence of multimorbidity (pooled OR 1.42, 95% CI 1.41 to 1.42). Associations between deprivation and multimorbidity differed by age and multimorbidity type. Findings from the few studies investigating household tenure, household composition and area-level rurality were mixed and contradictory; homeownership and rurality were associated with increased and decreased multimorbidity, while living alone was found to be associated with a higher risk of multimorbidity and not associated.ConclusionImproving our understanding of broader social determinants of multimorbidity—particularly at the household level—could help inform strategies to tackle multimorbidity.
Analysis of tumor-infiltrating NK and T cells highlights IL-15 stimulation and TIGIT blockade as a combination immunotherapy strategy for soft tissue sarcomas
Authors: Judge Sean J , Darrow Morgan A , Thorpe Steve W , Gingrich Alicia A , O'Donnell Edmond F , Bellini Alyssa R , Sturgill Ian R , Vick Logan V , Dunai Cordelia , Stoffel Kevin M , Lyu Yue , Chen Shuai , Cho May , Rebhun Robert B , Monjazeb Arta M , Murphy William J , Canter Robert J 
Published: November 2020

PurposeGiven the unmet need for novel immunotherapy in soft tissue sarcoma (STS), we sought to characterize the phenotype and function of intratumoral natural killer (NK) and T cells to identify novel strategies to augment tumor-infiltrating lymphocyte (TIL) function.Experimental designUsing prospectively collected specimens from dogs and humans with sarcomas, archived specimens, and The Cancer Genome Atlas (TCGA) data, we evaluated blood and tumor NK and T cell phenotype and function and correlated those with outcome. We then assessed the effects of interleukin 15 (IL-15) stimulation on both NK and T cell activation and TIGIT upregulation. Finally, we evaluated cytotoxic effects of IL-15 combined with TIGIT blockade using a novel anti-TIGIT antibody.ResultsTILs were strongly associated with survival outcome in both archived tissue and TCGA, but higher TIL content was also associated with higher TIGIT expression. Compared with blood, intratumoral NK and T cells showed significantly higher expression of both activation and exhaustion markers, in particular TIGIT. Ex vivo stimulation of blood and tumor NK and T cells from patients with STS with IL-15 further increased both activation and exhaustion markers, including TIGIT. Dogs with metastatic osteosarcoma receiving inhaled IL-15 also exhibited upregulation of activation markers and TIGIT. Ex vivo, combined IL-15 and TIGIT blockade using STS blood and tumor specimens significantly increased cytotoxicity against STS targets.ConclusionIntratumoral NK and T cells are prognostic in STS, but their activation is marked by significant upregulation of TIGIT. Our data suggest that combined IL-15 and TIGIT blockade may be a promising clinical strategy in STS.
Characteristics and outcomes of COVID-19 associated stroke: a UK multicentre case-control study
Authors: Perry Richard J , Smith Craig J , Roffe Christine , Simister Robert , Narayanamoorthi Saravanan , Marigold Richard , Willmot Mark , Dixit Anand , Hassan Ahamad , Quinn Terence J , Ankolekar Sandeep , Zhang Liqun , Banerjee Soma , Ahmed Urwah , Padmanabhan Nishita , Ferdinand Phillip , McGrane Frances , Banaras Azra , Marks Isobel H , Werring David J 
Published: November 2020

ObjectiveWe set out to determine which characteristics and outcomes of stroke are associated with COVID-19.MethodsThis case-control study included patients admitted with stroke to 13 hospitals in England and Scotland between 9 March and 5 July 2020. We collected data on 86 strokes (81 ischaemic strokes and 5 intracerebral haemorrhages) in patients with evidence of COVID-19 at the time of stroke onset (cases). They were compared with 1384 strokes (1193 ischaemic strokes and 191 intracerebral haemorrhages) in patients admitted during the same time period who never had evidence of COVID-19 (controls). In addition, the whole group of stroke admissions, including another 37 patients who appeared to have developed COVID-19 after their stroke, were included in two logistic regression analyses examining which features were independently associated with COVID-19 status and with inpatient mortality.ResultsCases with ischaemic stroke were more likely than ischaemic controls to occur in Asians (18.8% vs 6.7%, p<0.0002), were more likely to involve multiple large vessel occlusions (17.9% vs 8.1%, p<0.03), were more severe (median National Institutes of Health Stroke Scale score 8 vs 5, p<0.002), were associated with higher D-dimer levels (p<0.01) and were associated with more severe disability on discharge (median modified Rankin Scale score 4 vs 3, p<0.0001) and inpatient death (19.8% vs 6.9%, p<0.0001). Recurrence of stroke during the patient’s admission was rare in cases and controls (2.3% vs 1.0%, NS).ConclusionsOur data suggest that COVID-19 may be an important modifier of the onset, characteristics and outcome of acute ischaemic stroke.
Quadratus lumborum block: an imaging study of three approaches
Authors: Balocco Angela Lucia , López Ana M , Kesteloot Cedric , Horn Jean-Louis , Brichant Jean-François , Vandepitte Catherine , Hadzic Admir , Gautier Philippe 
Published: November 2020

Background and objectivesDifferent injection techniques for the quadratus lumborum (QL) block have been described. Data in human cadavers suggest that the transverse oblique paramedian (TOP) QL3 may reach the thoracic paravertebral space more consistently than the QL1 and QL2. However, the distribution of injectate in cadavers may differ from that in patients. Hence, we assessed the distribution of the injectate after the QL1, QL2, and TOP QL3 techniques in patients.Materials and methodsThirty-four patients scheduled for abdominal surgery received QL blocks postoperatively; 26 patients received bilateral and 8 patients received unilateral blocks. Block injections were randomly allocated to QL1, QL2, or TOP QL3 techniques (20 blocks per each technique). The injections consisted of 18 mL of ropivacaine 0.375% with 2 mL of radiopaque contrast, injected lateral or posterior to the QL muscle for the QL1 and QL2 techniques, respectively. For the TOP QL3, the injection was into the plane between the QL and psoas muscles, proximal to the L2 transverse process. Two reviewers, blinded to the allocation, reviewed three-dimensional computed tomography (3D-CT) images to assess the distribution of injectate.Results and discussionThe QL1 block spread in the transversus abdominis plane (TAP), QL2 in the TAP,andposterior aspect of the QL muscle, whereas TOP QL3 spread consistently in the anterior aspect of the QL musclewithoccasional spread to the lumbar and thoracic paravertebral areas.ConclusionsThe spread of injectate after QL1, QL2, and QL3 blocks, resulted in different distribution patterns, primarily in the area of injection. The TOP QL3 did not result in consistent interfascial spread toward the thoracic paravertebral space.
Macroeconomic impacts of cigarette consumption in Pakistan
Authors: Saleem Wasim , Iqbal Mohammad Asif 
Published: November 2020

BackgroundPakistan has a large population of tobacco users, with about 24 million adults consuming tobacco products in one form or another. There is a dearth of research on the impact of a reduction in tobacco use on Pakistan’s economy which can inform policy-makers on the extent that tobacco control measures would affect macroeconomic indicators such as output and employment.ObjectivesThe objective of this study is to quantify the changes in output, income and employment resulting from changes in cigarette consumption and to quantify the impact of such changes on the overall economy.MethodologyThe study uses the input–output table for the fiscal year 2010–2011 for Pakistan’s economy, to estimate the output, income and employment multipliers. The Leontief input–output model is used to estimate the sectorwise multiplier effects. It estimates direct, indirect and consumption-induced effects of changes in tobacco use on the economy.ResultsThe cigarette industry’s share in large-scale manufacturing and industrial employment is 1.1% and 0.3%, respectively. The estimates of gross output, income and employment multipliers for the cigarette industry have relatively small magnitudes indicating minimal impact on the economy. A simulation analysis based on the latest estimates of price elasticity of cigarette and input–output multipliers, shows that a 10% increase in price will lead to an 11% reduction in cigarette consumption, which translates into annual savings of Pakistani Rupees (Rs) 16 billion by households. Reduction in cigarette consumption will allow individuals to spend their savings on other commodities. For example, spending this amount on food items will lead to a net increase of Rs 40 billion annual output of the economy.ConclusionReduction in tobacco consumption will lead to initial losses to the economy but there will be considerable gains in output, employment and income due to redistribution of tobacco expenditures.