bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Ceramic Flat Slide Valve for Hydraulic Applications
Authors: Aengenheister Stefan , Liu Chao , Broeckmann Christoph , Schmitz Katharina 
Published: December 2019

Abstract
With a flat slide valve concept, a reduction in leakage and an increase in service life could be achieved compared to conventional piston spool valves. In order to achieve a reduction in leakage flows and guarantee the adjustability of the valves at the same time, a correct design of the pressure compensation is essential. The level of force depends on the operating point of the valve and the position of the slider. Due to the design of the flat slide valve, it is possible to use ceramic semi-finished products for the main stage, which consists of control plates and a slide plate. The geometries are simple enough to be inexpensively manufactured with sufficient accuracy from a ceramic pre-product using laser cutting technology.
High-tech ceramics are a promising material, which can contribute to an improvement of the performance of the valves. The higher resistance of ceramic materials to abrasive wear further increases the service life of the valves. Furthermore, ceramic materials show lower friction coefficients compared to metallic materials, which is of great importance for the concept of the flat slide valve due to the sliding of the plates on top of each other. However, at the same time the use of ceramics, which are rarely used in hydraulics at the moment, means that the design must be appropriate to the material and must be taken into account when designing the main valve stage. This article presents the concept of the flat slide valve for a proportional 4/3-way valve. Therefore, the design of the pressure compensation is shown and the current design of the main valve stage is presented. This includes the design of the flow channels, which has to be suitable for ceramic materials. The preliminary design of the flow channels were executed with CFD-simulations. With the shown design the function of a 4/3-way valve, known from piston spool valves, can be implemented with a linear behavior between slide plate deflection and opening cross section.
On the Energy Efficiency of Dual Prime Mover Pump-Controlled Hydraulic Cylinders
Authors: Gøytil Petter H. , Padovani Damiano , Hansen Michael R. 
Published: December 2019

Abstract
This paper concerns the energy efficiency of a special class of pump-controlled hydraulic cylinders utilizing two prime movers. The performance of such circuits has been studied previously motivated by their capability of providing an actuator stiffness similar to that of servo valve-controlled systems. This characteristic may improve performance and robustness in applications requiring feedback control. In this paper, the presence of losses similar to that of fluid throttling, in the sense that they occur even in the absence of component inefficiencies, are demonstrated for such circuits and shown to degrade the overall energy efficiency of the system. The conditions under which such losses occur are derived analytically as a function of system parameters and operating conditions and two solutions for their elimination are proposed and verified analytically and numerically. Several implementation options are compared in terms of energy efficiency and component sizing and benchmarked to a conventional servo valve solution. It is shown that with the appropriate implementation, an energy efficiency up to ten times greater than that of a conventional servo valve system may be expected.
Model-Based Control of a Pressure-Compensated Directional Valve With Significant Dead-Zone
Authors: Lampinen Santeri , Koivumäki Janne , Mattila Jouni , Niemi Jouni 
Published: December 2019

Abstract
Hydraulic systems on mobile manipulators and industrial systems often come equipped with pressure-compensated proportional directional control valves with significant dead-zone. These kind of hydraulic valves are well suited for open-loop applications with an operator in control. However, designing closed-loop control for such systems is a challenging task. In this study, we propose a model-based control method for such valves to increase the performance of the current state-of-the-art in industrial robotic manipulator control. The proposed control method rigorously addresses the dynamics of a hydraulic manipulator system with dead-zone compensation for pressure-compensated directional control valves. The proposed method is evaluated with experiments on a commercial heavy-duty breaker boom with Sauer-Danfoss PVG 120 valves. The experimental results show accurate control of the manipulator despite the used slow-response load sensing valves.
Automated Design and Analysis of a Variable Displacement Linkage Motor
Authors: Fulbright Nathaniel J. , Boyce-Erickson Grey C. , Chase Thomas R. , Li Perry Y. , Van de Ven James D. 
Published: December 2019

Abstract
Hydrostatic drives consisting of a variable displacement pump and a low speed high torque (LSHT) motor are frequently used in off-highway vehicles. A variable displacement traction motor is desirable because of the ability to downsize the pump and thereby run the hydrostat at higher efficiency, as well as the possibility of hybridization of the drivetrain. Currently on the market are fixed and discrete speed LSHT radial piston motors and high speed low torque variable displacement axial piston motors. The radial piston motors are displacement dense but are not continuously variable, whereas the axial piston motors are continuously variable but require gearboxes, introducing packaging and robustness concerns. The Variable Displacement Linkage Motor (VDLM) is a LSHT motor that is continuously variable. It offers several benefits over current LSHT motors in that it is highly efficient over its operating range, it has low torque ripple, and it is displacement dense due to its multi-lobed cam and radial packaging. As with the design of any motor, the process is iterative and must be performed whenever performance objectives change. This paper describes an automated method for rapid exploration of the solution space for a variable displacement motor with specific application to the VDLM. This method leads to a motor design that theoretically can achieve 97% efficiency with a torque ripple below 5% at full displacement.
Optimization of a Snap Through Spring for a Hydraulic Valve With Hysteresis Response Behavior
Authors: Scherrer Matthias , Scheidl Rudolf , Manhartsgruber Bernhard 
Published: December 2019

Abstract
The hydraulic binary counter requires switching valves with a hysteretic response. In this paper an elastic snap through element is studied as means for that. The concept is based on a buckling beam which is elastically supported in axial direction in order to adjust its buckling properties with moderate manufacturing precision and to assure a well defined snap through behavior. The elastic support is provided by a cantilever beam. A rigorous optimization is performed heading for a most compact and fatigue durable design which exhibits the required lateral force displacement characteristics. A genetic algorithm is used to find the global design optimum. The stress/displacement properties of each design variant are computed by a compact model of the snap through system. It is derived by a Ritz method to obtain approximate solutions of the nonlinear buckling beam behavior. Its validity is checked by a Finite Element model. A compact design is possible if high strength spring steel is used for the elastic elements.
Analysis of Power Distribution in the Hydraulic Remote System of Agricultural Tractors Through Modelling and Simulations
Authors: Tian Xin , Gomez Josias Cruz , Vacca Andrea , Fiorati Stefano , Pintore Francesco 
Published: December 2019

Abstract
Agricultural tractors make massive use of hydraulic control technology. Being fuel consumption a big concern for agricultural applications, tractors typically use the latest state-of-the-art technology to allow efficient fluid power actuation. Nevertheless, the quantification of the energy loss within the hydraulic system of such applications represents an important step to drive the development of the current technology with cost-effective solutions.
In this paper, the load sensing (LS) circuit that typically equips of the hydraulic remotes is taken as reference. A simulation model has been developed within the Amesim software with the aim of accurately predict the operation of the system including the energy flow from the hydraulic supply to the hydraulic user. The paper particularly details the models of the LS pump and the hydraulic remote valves. Within the research, experimental tests on a reference tractor were designed and executed to allow the model validation. The comparison between the experimental results and the simulation data shows the validity of the model. Furthermore, the model allows highlighting the energy losses in the different components of the system as well as identifying the most favorable operating conditions of the system with respect to energy efficiency. The model can be used in support of future research aimed at formulating a more efficient solution for the hydraulic circuit of agricultural tractors.
Mass Estimation of Self-Contained Linear Electro-Hydraulic Actuators and Evaluation of the Influence on Payload Capacity of a Knuckle Boom Crane
Authors: Ketelsen Søren , Andersen Torben Ole , Ebbesen Morten Kjeld , Schmidt Lasse 
Published: December 2019

Abstract
Self-contained linear hydraulic drives are characterized by having integrated the hydraulic power unit e.g. electrical prime mover, hydraulic pumps etc. and the hydraulic cylinder in a single compact unit. Compared to the hydraulic cylinder itself, the mass of the self-contained linear actuator is significantly larger. For some applications, e.g. crane manipulators the additional mass of the actuators compared to conventional valve-controlled hydraulics, may reduce the payload capacity, which is a central performance parameter. As a case study, a medium sized two link knuckle boom crane is modelled and by assuming the force capability of the hydraulic cylinders to be the limiting factor, the reduction in payload capacity is examined if replacing the knuckle boom cylinder with a self-contained hydraulic cylinder drive. By focusing on seven different hydraulic circuit architectures, this study estimates the mass of compact pump-controlled actuators and investigates to what extent the choice of system topology affects the mass of the actuator, and thus payload capacity of the crane. The results show that the choice of hydraulic circuit architecture may affect both the required amount of installed power and the mass of the self-contained actuator. For the considered knuckle boom crane the estimated mass of the needed 59 kW self-contained actuator ranges from 2300 kg to 2521 kg depending on the hydraulic circuit architecture. The mass of the hydraulic cylinder itself used for conventional valve actuation is estimated to 1674 kg. If the entire working range is considered, installing the heavier self-contained actuator reduces the payload capacity with up to 3 % compared to conventional valve actuation.
Fluid Effects on Mechanical Efficiency of Hydraulic Pumps: Dynamometer Measurements and Molecular Simulations
Authors: Panwar Pawan , Len Michelle , Gajghate Ninaad , Michael Paul , Martini Ashlie 
Published: December 2019

Abstract
The mechanical efficiency of hydraulic pumps is affected by the viscosity of the hydraulic fluid. Viscosity modifiers that thicken the fluid, therefore, play an important role in efficiency. Viscosity modifiers are believed to improve the mechanical efficiency of hydraulic systems partially by enabling formulation with lower molecular weight base oils. Here, this concept was directly tested in a pump dynamometer using mixtures of low traction synthetic poly(alphaolefin) base oils, bis(2-ethylhexyl) adipate ester, and poly(isobutylene). Lower viscosity fluids directly correlated to better mechanical efficiency but decreasing the viscosity of the synthetic base oil by adding viscosity modifier did not have the same effect. However, molecular dynamics simulations showed that solution viscosity was directly correlated to elongation of the polymer under shear which, together with calculations of the critical shear rate range in a pump, suggested ways of designing viscosity modifiers to achieve a specific viscosity profile that maximizes mechanical efficiency.
A Buford Complex in a Division I Collegiate American Football Player
Authors: Wiese Brian W. , Miller Kevin , Godoy Eduardo 
Published: December 2019

A 19-year-old African-American male Division I collegiate American football player with no prior history of shoulder injury presented with right shoulder pain after making a tackle during a game. He was initially diagnosed with a rotator cuff strain with potential underlying labral pathology. Subsequent magnetic resonance imaging arthrogram showed no labral tearing, though a Buford complex was identified. A Buford complex is a normal anatomical labral variant where the anterior labrum is absent and the middle glenohumeral ligament is “cord-like” in structure. This case was managed conservatively since surgical intervention is only recommended if there is a secondary pathology to the shoulder (e.g., type II superior labrum anterior to posterior [SLAP] lesions). Clinicians should be aware of Buford complexes because they can predispose athletes to secondary injuries and can be managed successfully with a conservative rehabilitation approach in the absence of secondary pathology.
The Effect of Pre–Post Differences in Walking, Health, and Weight on Retirees’ Long-Term Quality of Life
Authors: Deka Devajyoti 
Published: December 2019

This research examined the effect of pre–post differences in walking duration, health, and weight on retirees’ long-term quality of life (QoL). It used data from a 2018 randomized mail survey of 483 suburban New Jersey retirees. Ordinary least squares and three-stage least squares models were used. The analysis showed that changes in walking duration during the first 2 years of retirement are directly associated with health change, health change has an effect on long-term QoL, and weight variation of 10 lb or more has an effect on health change and long-term QoL. Although QoL peaks for the sample of retirees at around age 75, people whose average walking duration increased, health improved, and weight did not increase substantially after retirement continued to experience high QoL for a longer time. The results show that people can achieve high long-term QoL by choosing an active lifestyle when transitioning to retirement.
Clinical and economic outcomes among injection-naïve patients with type 2 diabetes initiating dulaglutide compared with basal insulin in a US real-world setting: the DISPEL Study
Authors: Mody Reema , Huang Qing , Yu Maria , Patel Hiren , Zhang Xian , Wang Liya , Grabner Michael 
Published: December 2019

AimsTo report 1-year clinical and economic outcomes from the retrospective DISPEL (Dulaglutide vs Basal InSulin in Injection Naïve Patients with Type 2 Diabetes: Effectiveness in ReaL World) Study.Materials and methodsThis observational claims study included patients with type 2 diabetes (T2D) and ≥1 claim for dulaglutide or basal insulin between November 2014 and April 2017 (index date=earliest fill date). Propensity score matching was used to address treatment selection bias. Change from baseline in hemoglobin A1c (HbA1c) was compared between the matched cohorts using analysis of covariance; diabetes-related costs were analyzed using generalized linear models.ResultsMatched cohorts (903 pairs total; 523 pairs with complete cost data) were balanced in baseline characteristics with mean HbA1c 8.6%, mean age 54 years. At 1 year postindex, dulaglutide patients had significantly greater reduction in HbA1c than basal insulin (−1.12% vs −0.51%, p<0.01), lower medical costs ($3753 vs $7604, p<0.01), higher pharmacy costs ($9809 vs $6175, p<0.01), and similar total costs ($13 562 vs $13 779, p=0.76). Medical and total costs per 1% HbA1c reduction were lower for dulaglutide than basal insulin (medical: $3128 vs $12 673, p<0.01; total: $11 302 vs $22 965, p<0.01), while pharmacy costs per 1% HbA1c reduction were lower without reaching statistical significance ($8174 vs $10 292, p=0.15).ConclusionsIn this real-world study, patients with T2D initiating dulaglutide demonstrated greater HbA1c reduction compared with those initiating basal insulin. Although total diabetes-related costs were similar, the total diabetes-related costs per HbA1c reduction were lower for dulaglutide, highlighting the importance of evaluating effectiveness along with the economic impact of medications.
Social networks, social capital and end-of-life care for people with dementia: a realist review
Authors: Sawyer Joseph M , Sallnow Libby , Kupeli Nuriye , Stone Patrick , Sampson Elizabeth L 
Published: December 2019

Objectives(1) To develop an understanding of how social capital may be conceptualised within the context of end-of-life care and how it can influence outcomes for people with dementia and their families with specific reference to the context and mechanisms that explain observed outcomes. (2) To produce guidance for healthcare systems and researchers to better structure and design a public health approach to end-of-life care for people with dementia.DesignA realist review.Data sourcesMEDLINE, EMBASE, CINAHL and grey literature.AnalysisWe conceptualised social capital as a complex intervention and, in order to understand how change is generated, used realist evaluation methods to create different configurations of context, mechanism and outcomes. We conducted an iterative search focusing on social capital, social networks and end-of-life care in dementia. All study designs and outcomes were screened and analysed to elicit explanations for a range of outcomes identified. Explanations were consolidated into an overarching programme theory that drew on substantive theory from the social sciences and a public health approach to palliative care.ResultsWe identified 118 articles from 16 countries ranging from 1992 to 2018. A total of 40 context-mechanism-outcome configurations help explain how social capital may influence end-of-life care for people with dementia. Such influence was identified within five key areas. These included: (1) socially orientating a person with dementia following diagnosis; (2) transitions in the physical environment of care; (3) how the caregiving experience is viewed by those directly involved with it; (4) transition of a person with dementia into the fourth age; (5) the decision making processes underpinning such processes.ConclusionThis review contributes to the dispassionate understanding of how complex systems such as community and social capital might be viewed as a tool to improve end-of-life care for people with dementia.PROSPERO registration numberCRD42018084524.
Catch-up-ESUS - follow-up in embolic stroke of undetermined source (ESUS) in a prospective, open-label, observational study: study protocol and initial baseline data
Authors: Feil Katharina , Heinrich Johanna , Küpper Clemens , Müller Katharina , Laub Christoph , von Falkenhausen Aenne S , Becker Regina , Wollenweber Frank A , Kääb Stefan , Sinner Moritz F , Kellert Lars 
Published: December 2019

IntroductionSo far there is no uniform, commonly accepted diagnostic and therapeutic algorithm for patients with embolic stroke of undetermined source (ESUS). Recent clinical trials on secondary stroke prevention in ESUS did not support the use of oral anticoagulation. As ESUS comprises heterogeneous subgroups including a wide age-range, concomitant patent foramen ovale (PFO), and variable probability for atrial fibrillation (AF), an individualised approach is urgently needed. This prospective registry study aims to provide initial data towards an individual, structured diagnostic and therapeutic approach in ESUS patients.Methods and analysisThe open-label, investigator-initiated, prospective, single-centre, observational registry study (Catch-up-ESUS) started in 01/2018. Consecutive ESUS patients ≥18 years who give informed consent are included and will be followed up for 3 years. Stratified by age <60 or ≥60 years, the patients are processed following a standardised diagnostic and treatment algorithm with an interdisciplinary design involving neurologists and cardiologists. Depending on the strata, patients receive a transesophageal echocardiogram; all patients receive an implantable cardiac monitor. Patients <60 years with PFO and without evidence of concomitant AF are planned for PFO closure within 6 months after stroke. The current diagnostic and therapeutic workup of ESUS patients requires improvement by both standardisation and a more individualised approach. Catch-up-ESUS will provide important data with respect to AF detection and PFO closure and will estimate stratified stroke recurrence rates after ESUS.Ethics and disseminationThe study has been approved by the responsible ethics committee at the Ludwig Maximilian University, Munich, Germany (project number 17–685). Catch-Up-ESUS is conducted in accordance with the Declaration of Helsinki. All patients will have to give written informed consent or, if unable to give consent themselves, their legal guardian will have to provide written informed consent for their participation. The first observation period of the registry study is 1 year, followed by the first publication of the results including follow-up of the patients. Further publications will be considered according the predefined individual follow-up dates of the stroke patients up to 36 months.Trial registration numberClinicaltrialsregister.gov registry (NCT03820375).
Speaking Up for Fundamental Care: the ILC Aalborg Statement
Authors: Kitson Alison , Carr Devin , Conroy Tiffany , Feo Rebecca , Grønkjær Mette , Huisman-de Waal Getty , Jackson Debra , Jeffs Lianne , Merkley Jane , Muntlin Athlin Åsa , Parr Jennifer , Richards David A , Sørensen Erik Elgaard , Wengström Yvonne 
Published: December 2019

ObjectiveThe International Learning Collaborative (ILC) is an organisation dedicated to understanding why fundamental care, the care required by all patients regardless of clinical condition, fails to be provided in healthcare systems globally. At its 11th annual meeting in 2019, nursing leaders from 11 countries, together with patient representatives, confirmed that patients’ fundamental care needs are still being ignored and nurses are still afraid to ‘speak up’ when these care failures occur. While the ILC’s efforts over the past decade have led to increased recognition of the importance of fundamental care, it is not enough. To generate practical, sustainable solutions, we need to substantially rethink fundamental care and its contribution to patient outcomes and experiences, staff well-being, safety and quality, and the economic viability of healthcare systems.Key argumentsWe present five propositions for radically transforming fundamental care delivery:Value: fundamental care must be foundational to all caring activities, systems and institutionsTalk: fundamental care must be explicitly articulated in all caring activities, systems and institutions.Do: fundamental care must be explicitly actioned and evaluated in all caring activities, systems and institutions.Own: fundamental care must be owned by each individual who delivers care, works in a system that is responsible for care or works in an institution whose mission is to deliver care.Research: fundamental care must undergo systematic and high-quality investigations to generate the evidence needed to inform care practices and shape health systems and education curricula.ConclusionFor radical transformation within health systems globally, we must move beyond nursing and ensure all members of the healthcare team—educators, students, consumers, clinicians, leaders, researchers, policy-makers and politicians—value, talk, do, own and research fundamental care. It is only through coordinated, collaborative effort that we will, and must, achieve real change.