bluuebunny/crossref_metadata_2025_split huggingface dataset:
Commutation Loss in Hydrostatic Pumps and Motors
Authors: Mommers Robin , Achten Peter , Achten Jasper , Potma Jeroen 
Published: December 2021

Abstract
In mobile hydraulic applications, more efficient machinery generally translates to smaller batteries or less diesel consumption, and smaller cooling solutions. A key part of such systems are hydrostatic pumps and motors. While these devices have been around for a long time, some of the causes of energy loss in pump and motors are still not properly defined. This paper focuses on one of the causes of energy loss in pumps and motors, by identifying the energy loss as a result of the process of commutation.
By nature, all hydrostatic pumps and motors have some form of commutation: the transition from the supply port to the discharge port of the machine (and vice versa). During commutation, the connection between the working chamber and the ports is temporarily closed. The chamber pressure changes by compression or decompression that is the result of the rotation of the working mechanism. Ideally, the connection to one of the ports is opened once the chamber pressure equals the port pressure. When the connection is opened too early or too late, energy is lost.
This paper describes a method to predict the commutation loss using a lumped parameter simulation model. To verify these predictions, experimental data of a floating cup pump was compared to the calculated values, which show a decent match. Furthermore, the results show that, depending on the operating conditions, up to 50% of all losses in this pump are caused by improper commutation.
Noise Attenuation in a Secondary Controlled Electro-Hydraulic Actuator Using an Extended Kalman Filter
Authors: Simonsen Niklas , Sørensen Emil Munk , Binsbergen-Galán Mikkel van , Kleine Stine Flindt Hornemann , Nielsen Mikkel Hvid , Schmidt Lasse 
Published: December 2021

Abstract
Conventionally, variable-speed electro-hydraulic linear actuators utilize the speed control loops of electric machines and associated drives to control the pump flows, thereby realizing primary control functions. An alternative control approach is secondary control, which realizes a pressure coupling between the motor/pump and cylinder via the electromagnetic motor torque, with a flow reaction. Secondary controls in such drives has theoretically been shown to enable significantly higher control band-widths compared to primary control approaches. The theoretical bandwidth improvement is possible as the secondary control approach utilizes the faster dynamics of the electric machine, whereas the primary control approach revolves about the slower hydraulic dynamics present in the speed control loop. This paper considers the design and implementation of a secondary control function in a variable-speed electro-hydraulic actuator test bench, in order to validate the properties of such controls. Initial results show that the proposed secondary control approach is highly sensitive to measurement noise, which proves to be a limiting factor for the achievable control bandwidth, if smooth operation of the system is to be maintained. To attenuate the noise impact an extended Kalman filter is proposed in conjunction with the secondary control approach. Results demonstrate that the inclusion of the extended Kalman filter significantly reduces the impact of signal noise on the internal drive states, thereby enabling increased bandwidth and expanding the application range for this control method.
Investigating the Condition Monitoring Potential of Oil Conductivity for Wear Identification in Electro Hydrostatic Actuators
Authors: Duensing Yannick , Richert Oliver , Schmitz Katharina 
Published: December 2021

Abstract
To meet future goals of more electric airplanes conventional hydraulic airplane control systems, consisting of redundant centralized pumps within the airplane’s fuselage, need to be substituted for compact electro-hydraulic actuators (EHA). The capsulated architecture of EHAs results in higher safety due to separate hydraulic circuits, simple practicability of redundancy, decreased maintenance because of simplified error location detection as well as an overall reduction in weight and complexity of the airplane control system. Currently, EHAs are only used as backup devices as the reliability does not achieve normative requirements for a frontline application. Thus, recent studies aim to increase the reliability. The axial piston pump of current EHA is the source of most failures. High dynamic requirements and challenging operation points and environments result in wear of contact pairs such as swash plate/piston shoes, pistons/cylinder block and cylinder block/valve plate. In the scope of the project MODULAR at ifas one goal is to increase the robustness of the contact surfaces. A second goal addresses the topic of developing a condition monitoring approach to constantly track the pumps’ health status. Next to signals such as pressures and temperatures, acceleration and oil status signals describing the actual particle contamination are needed. In this contribution different methods of oil status detection are explained and the method of electric conductivity analysis for condition monitoring is further investigated. Filtered HLP46 is used and impurities in form of metallic powders are added. Furthermore, degraded oil of a disc-on-disc Tribometer test bench is measured and compared.
Novel Methods and Technologies for Assessing Usability of Off-Road Machines in R&D Phase - The Lutergo Laboratory
Authors: Zhidchenko Victor , Hekmatmanesh Amin , Handroos Heikki , Kilpeläinen Asko , Kauranen Kari 
Published: December 2021

Abstract
A novel intelligent experimental research environment (LUTERGO laboratory) for developing the usability of off-road machines was created at LUT University. The environment combines a real-time simulator and an experimental system for measuring human body responses when driving the virtual prototypes of machines. Based on the quantities measured from the operator, such as heart rate, electrodermal, muscular, and brain activity, the stress level of the operator can be evaluated. It is assumed that by combining simulated machine data and biosignals, the usability of every virtual prototype of a new machine can be assessed during the R&D process. This is an alternative to a traditional approach when usability is studied with physical prototypes after conceptual R&D phases using qualitative data from questionnaires.
The paper describes the structure and capabilities of the LUTERGO laboratory. Results of the initial tests are presented, which studied the influence of hydraulic valve dynamics on excavator vibration and operator biosignals. The results show that the biosignal parameters used as stress indicators change following the variation of time constant for directional valves controlling the main boom cylinders of the excavator. The paper concludes with future research directions using the novel environment.
Gain-Scheduled Position Control of a Pneumatic Muscle Actuator
Authors: Cotton Matthew , Plummer Andrew 
Published: December 2021

Abstract
Pneumatic artificial muscles (PAMs) are high power-to-weight ratio actuators with considerable potential in biomimetic robotics and orthotics due to their similarities with human skeletal muscle. However, precise position control is difficult to achieve due to the highly nonlinear nature of the actuators and the pneumatic systems driving them. A wide range of nonlinear controllers have been proposed to-date, but none have been shown to be entirely satisfactory, and are often optimised for only one region of the PAM’s travel.
In this paper, a gain-scheduled position controller is designed that aims to achieve equal tracking performance across the entire travel of the PAM. Selected scheduling variables include actuator displacement and error direction, with controller gains defined by ‘normalisation curves’ determined by data from open-loop characterisation tests. The experimental system consists of a Festo PAM, a pair of on-off valves driven by pulse-width modulated signals, and sensors for PAM displacement and pressure. Controller performance is tested using several dynamic position tracking tests, and the results are compared to an equivalent linear controller. The gain-scheduled approach successfully counteracts the differing inflation / deflation dynamics of the system, showing improved tracking performance over the linear controller with considerably less variability due to operating region.
Investigating the Influence of Design Parameters on the Fluid-Structure Interaction in Fast Switching Valves
Authors: Pedersen Henrik C. , Andersen Torben O. , Bender Niels C. 
Published: December 2021

Abstract
When considering digital displacement machines, one of the key elements are the fast switching valves. However, the dynamic requirements and conflicting design objectives mean that designing these fast-switching valves is a complex process, which pushes the technology to the limit. Optimization approaches are therefore required just to find feasible and, secondly, optimal solutions. However, dynamic CFD simulation is required to accurately describe dynamic fluid effects as fluid stiction, -drag and -end damping. This limits the possibilities to use optimization approaches due to the computational burden imposed, the need for dynamic mesh generation, and the design parameterization. Hence, this paper investigates analytical approximations and the error size introduced by simplifying dynamic fluid friction effects into a lumped parameter form.
Specifically, the article presents a comprehensive parameter study of selected design parameters’ influence on the fluid forces in fast switching annulus valves, based on both analytical expressions and results derived from dynamic CFD simulations. The focus is primarily on describing the effects and size of the flow forces resulting from changes in parametric design parameters that influence the flow geometry. The results reveal a fair correlation between the fluid force predicted by the rapidly executable lumped model and the CFD model.
Prostate-specific membrane antigen positron emission tomography compared to multiparametric MRI for prostate cancer diagnosis: a protocol for a systematic review and meta-analysis
Authors: Zhao Yi , Morka Naomi , Simpson Benjamin Scott S , Freeman Alex , Kirkham Alex , Kelly Daniel , Whitaker Hayley C , Emberton Mark , Norris Joseph M 
Published: December 2021

IntroductionThe introduction of multiparametric MRI (mpMRI) has improved almost every aspect of the prostate cancer diagnostic pathway. However, the novel imaging technique, prostate-specific membrane antigen positron emission tomography (PSMA PET) may have demonstrable accuracy in detecting and staging prostate cancer. Here, we describe a protocol for a systematic review and meta-analysis comparing mpMRI to PSMA PET for the diagnosis of suspected prostate cancer.Methods and analysisA systematic search of MEDLINE, EMBASE, PubMed and Cochrane databases will be conducted. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines will be followed for screening, data extraction, statistical analysis and reporting. Included papers will be full-text articles providing original data, written in English articles and comparing the use of PSMA PET with mpMRI in the diagnosis of prostate cancer. All studies published between July 1977 and March 2021 will be eligible for inclusion. Study bias and quality will be assessed using Quadas-2 score. To ensure the quality of the reporting of studies, this protocol is written following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols 2015 checklist.Ethics and disseminationEthical approval will not be required for this systematic review. Findings will be disseminated through peer-reviewed publications and presentations at both national and international conferences.PROSPERO registration numberCRD42021239296.
Comparison of embolization strategies for mixed plexiform and fistulous brain arteriovenous malformations: a computational model analysis of theoretical risks of nidus rupture
Authors: Jain Mika S , Telischak Nicholas A , Heit Jeremy J , Do Huy M , Massoud Tarik F 
Published: December 2021

BackgroundHigh-flow fistulas related to plexiform nidi are found in 40% of large brain arteriovenous malformations (AVMs). Endovascular occlusion of intranidal fistulas before plexiform components is empirically considered safe, but potential ensuing dangerous re-routing of flow through plexiform vessels may in theory raise their rupture risk. It remains unclear whether it is safer to embolize plexiform or fistulous vessels initially. We used a novel biomathematical AVM model to compare theoretical hemodynamic changes and rupture risks on sequential embolizations of both types of nidus vessels.MethodsWe computationally modeled a theoretical AVM as an electrical circuit containing a nidus consisting of a massive stochastic network ensemble comprising 1000 vessels. We sampled and individually simulated 10 000 different nidus morphologies with a fistula angioarchitecturally isolated from its adjacent plexiform nidus. We used network analysis to calculate mean intravascular pressure (Pmean) and flow rate within each nidus vessel; and Monte Carlo analysis to assess overall risks of nidus rupture when simulating sequential occlusions of vessel types in all 10 000 nidi.ResultsWe consistently observed lower nidus rupture risks with initial fistula occlusion in different network morphologies. Intranidal fistula occlusion simultaneously reduced Pmeanand flow rate within draining veins.ConclusionsInitial occlusion of AVM fistulas theoretically reduces downstream draining vessel hypertension and lowers the risk of rupture of an adjoining plexiform nidus component. This mitigates the theoretical concern that fistula occlusion may cause dangerous redistribution of hemodynamic forces into plexiform nidus vessels, and supports a clinical strategy favoring AVM fistula occlusion before plexiform nidus embolization.
Morphology and Late Pleistocene–Holocene sedimentation of the Strait of Istanbul (Bosphorus): a review
Authors: Çağatay M. Namık , Eriş K. Kadir , Erdem Zeynep 
Published: December 2021

Abstract
The Bosphorus (Istanbul) Strait is a natural strait that connects the Black Sea with the Aegean Sea via the Sea of Marmara and the Dardanelles Strait. It is a 31 km-long and 3.5 km-wide winding channel, with an irregular bottom morphology. It has depressions up to 110 m deep, and two sills with depths of 35 and 58 m in the south and north, respectively. Presently, a two-layer water exchange exists through the strait, with the Mediterranean and Black Sea waters forming the lower and upper layers, respectively. The Bosphorus channel extends as shelf valleys on the Black Sea and Sea of Marmara shelves. However, it operated as a river valley or an estuary during the stadial lowstand periods.
The infill sedimentary succession of the Bosphorus channel is up to 100 m thick above the Paleozoic–Cretaceous basement with an irregular topography. The oldest sediments are sandy to muddy fluvial–lacustrine facies of late Pleistocene age, which are preserved only in up to 160 m-deep scoured depressions of the basement. They are overlain by mid–late Holocene estuarine–marine shelly sandy to muddy sediments with patches of bioherms and shelly lag deposits.

The Bosphorus outlet areas of the Black Sea and Sea of Marmara are characterized by a submarine fan and a shelf valley, respectively. The fan system in the Black Sea started depositing
c.
900 years after the initial vigorous marine water incursion at
c.
8.4
14
C ka BP. On the Marmara shelf, extension of the Bosphorus channel is a sinuous shelf valley with a channel–levee complex that was deposited by the Black Sea outflow during 11–10
14
C ka BP. Catastrophic floodings of the Sea of Marmara by torrential Black Sea outflows during the Greenland Interstadial melt-water pulses, as well as the strong Mediterranean current towards the Black Sea during the interglacial periods, were responsible for carving out the Bosphorus channel and the shelf valleys, as well as removing the sediments belonging to the earlier periods.
Analgesic Use and Circulating Estrogens, Androgens, and Their Metabolites in the Women's Health Initiative Observational Study
Authors: Hurwitz Lauren M. , Shadyab Aladdin H. , Tabung Fred K. , Anderson Garnet L. , Saquib Nazmus , Wallace Robert B. , Wild Robert A. , Pfeiffer Ruth M. , Xu Xia , Trabert Britton 
Published: December 2021

AbstractThough studies have observed inverse associations between use of analgesics (aspirin, NSAIDs, and acetaminophen) and the risk of several cancers, the potential biological mechanisms underlying these associations are unclear. We investigated the relationship between analgesic use and serum concentrations of estrogens, androgens, and their metabolites among postmenopausal women to provide insights on whether analgesic use might influence endogenous hormone levels, which could in turn influence hormone-related cancer risk. The study included 1,860 postmenopausal women from two case–control studies nested within the Women's Health Initiative Observational Study. Analgesic use was reported at study baseline. Fifteen estrogens and estrogen metabolites and 12 androgens and androgen metabolites were quantified in baseline serum by LC/MS-MS. Linear regression with inverse probability weighting, stratified by menopausal hormone therapy (MHT) use, was used to estimate adjusted geometric mean concentrations of each hormone by analgesic use. Among women not currently using MHT (n = 951), low-dose aspirin (&lt;100 mg) use was associated with a higher serum concentration of estrone, estradiol, and 2, 4, and 16 hydroxylated metabolites. Use of regular-dose aspirin (≥100 mg), non-aspirin NSAIDs, and acetaminophen was not associated with serum concentrations of estrogens, androgens, or their metabolites. This study highlights the importance of examining aspirin use by dose and suggests that low-dose aspirin may influence endogenous estrogen concentrations.Prevention relevance:This study explores a potential pathway by which analgesic medications such as aspirin may prevent hormone-related cancers. The findings support a positive association between low-dose aspirin use and endogenous estrogens, indicating that further elucidation of the interplay between low-dose aspirin, estrogen concentrations, and cancer risk is needed.
Blockade or Deletion of IFNγ Reduces Macrophage Activation without Compromising CAR T-cell Function in Hematologic Malignancies
Authors: Bailey Stefanie R. , Vatsa Sonika , Larson Rebecca C. , Bouffard Amanda A. , Scarfò Irene , Kann Michael C. , Berger Trisha R. , Leick Mark B. , Wehrli Marc , Schmidts Andrea , Silva Harrison , Lindell Kevin A. , Demato Ashley , Gallagher Kathleen M.E. , Frigault Matthew J. , Maus Marcela V. 
Published: December 2021

Abstract

Chimeric antigen receptor (CAR) T cells induce impressive responses in patients with hematologic malignancies but can also trigger cytokine release syndrome (CRS), a systemic toxicity caused by activated CAR T cells and innate immune cells. Although IFNγ production serves as a potency assay for CAR T cells, its biologic role in conferring responses in hematologic malignancies is not established. Here we show that pharmacologic blockade or genetic knockout of IFNγ reduced immune checkpoint protein expression with no detrimental effect on antitumor efficacy against hematologic malignancies in vitro or in vivo. Furthermore, IFNγ blockade reduced macrophage activation to a greater extent than currently used cytokine antagonists in immune cells from healthy donors and serum from patients with CAR T-cell–treated lymphoma who developed CRS. Collectively, these data show that IFNγ is not required for CAR T-cell efficacy against hematologic malignancies, and blocking IFNγ could simultaneously mitigate cytokine-related toxicities while preserving persistence and antitumor efficacy.

Significance:
Blocking IFNγ in CAR T cells does not impair their cytotoxicity against hematologic tumor cells and paradoxically enhances their proliferation and reduces macrophage-mediated cytokines and chemokines associated with CRS. These findings suggest that IFNγ blockade may improve CAR T-cell function while reducing treatment-related toxicity in hematologic malignancies.
See interview with Stefanie R. Bailey, PhD, recipient of the 2023 Blood Cancer Discovery Award for Outstanding Journal Article: https://vimeo.com/847433865
See related content by McNerney et al., p. 90 (17).
This article is highlighted in the In This Issue feature, p. 85
Potential Role of IFNγ Inhibition in Refractory Cytokine Release Syndrome Associated with CAR T-cell Therapy
Authors: McNerney Kevin O. , DiNofia Amanda M. , Teachey David T. , Grupp Stephan A. , Maude Shannon L. 
Published: December 2021

Summary:
Here we review the pathophysiology and management of cytokine release syndrome (CRS) secondary to immunotherapy, and potential options for CRS refractory to IL6 inhibition and glucocorticoids, for which there are no proven treatments. To illustrate, we describe a patient with B-cell acute lymphoblastic leukemia who developed refractory grade 4 CRS following CD19-directed chimeric antigen receptor T-cell therapy, treated with tocilizumab, methylprednisolone, siltuximab, and the IFNγ inhibitor emapalumab, with complete remission from leukemia for 12 months.
See related article by Bailey et al., (15).
Reducing Health Care Burden of Emergency General Surgery with a 24-Hour Dedicated Emergency General Surgery Service
Authors: Roy J. David , Hardy W. Johnson , Roberts Morgan E. , Stahl Joseph E. , Butts C. Caleb , Simmons Jon D. , Barber William H. 
Published: December 2021

Background Emergency general surgery (EGS) diagnoses account for 11% of surgical admissions and 50% of surgical mortality. In this population, 7 specific operations are associated with 80.3% of deaths, 78.9% of complications, and 80.2% of hospital costs. In 2016, our institution established a comprehensive in-house EGS service. Herein, we hypothesize that formation of a dedicated EGS service is associated with a significant reduction in morbidity for patients undergoing the most common EGS procedures. Methods All patients undergoing one of the most common EGS procedures within 2 days of admission were identified from 1/1/2013 to 5/9/2019 via a retrospective chart review. Patients were cohorted as pre- and post-EGS implementation. The primary outcome measure was the overall complication rate. Secondary endpoints included mortality, individual complication rate, time to operation, overnight operation, and length of stay. Finally, both cohorts were benchmarked to national outcomes. Results 718 patients met inclusion criteria (pre-EGS = 409 and post-EGS = 309). Overall complication rate decreased significantly (19.8% vs 13.9%, P = .0387) and overnight operations increased significantly in the post-EGS group (7.8%-16.5%, P = .0003). Pre-EGS complications were higher than national data in all but 1 procedure group, whereas post-EGS complications rates were lower in all but 2 categories. Discussion Implementation of a dedicated EGS service line was associated with a significant decrease in complication rate among the most complication-prone EGS procedures. Number of operations within 24 hours did not increase significantly; however, overnight operations did increase. Our results indicate that establishing a service-specific EGS line is reasonable and beneficial.