bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Situ Investigation of Load-Dependent Nonlinearities in Tangential Stiffness and Damping of Spherical Contacts
Authors: Eriten Melih , Chen Shixuan , Usta Ahmet D. , Yerrapragada Karthik 
Published: September 2020

Abstract
Seemingly stationary (pre-sliding) interfaces between different materials, parts, and components are major sources of compliance and damping in structures. Classical pre-sliding contact models assume smooth elastic contact and predict that frictional slip leads to a well-defined set of stiffness and damping nonlinearities. However, reported data deviate from those predictions, and literature lacks a conclusive evidence leading to those deviations. In this work, the authors measure tangential stiffness and damping capacities inside a scanning electron microscope (SEM) while monitoring contacts between a rigid spherical probe and two materials (high-density polyethylene (HDPE) and polyurethane elastomer). Measured force, displacement, contact area, stiffness, and damping are then compared with predictions of classical models. In situ SEM images synchronized to the tangential force–displacement responses are utilized to relate the degree of plasticity and geometric alterations to stiffness and damping nonlinearities. In agreement with the classical models, increasing tangential loads cause softening in contacts under light normal preloads. In contrast, stiffness for HDPE increases with increasing tangential loads at heavy normal preloads due to plasticity and pileups over the contact. Material damping is prevalent for all loading cases in polyurethane samples thanks to nearly fully adhered contact, whereas for only light tangential loads in HDPE. With increasing tangential loading, specific damping capacity of HDPE contacts increases tenfold. This nonlinear increase is due to plastic shearing and frictional losses induced by tangential loading. Those findings suggest that predictive interface models should include geometric alterations of contact, plasticity, and material damping.
Gas and Water Rate Forecasting of Coalbed Methane Reservoirs Based on the Rescaled Exponential Method
Authors: Guo Xiao , Zhang Tongyi , Di Dejia , Qin Xing , Zhai Yujia , Du Juan , Mao Jun 
Published: September 2020

Abstract
The traditional production data analysis (PDA) techniques for gas wells largely relied on the implement of pseudo-functions and related type curve methods. Recently, Ye and Ayala (2012 “A Density Diffusivity Approach for the Unsteady State Analysis of Natural Gas Reservoirs,” J. Nat Gas Sci. Eng., 7, pp. 22–34.) proposed a new rescaled exponential method which can successfully capture the behavior of gas well under boundary-dominated flow (BDF) conditions with the density-based parameters. In this paper, this rescaled exponential method is extended in coalbed methane (CBM) reservoirs by accounting for the two-phase flow behavior, and the variable permeability characteristics in the coal seams that caused by mechanical compression, desorption shrinkage, and the desorption effect. The two-phase rescaled exponential solution for CBM reservoir is derived by modifying the definition of two-phase pseudo-pressure and total compressibility. The proposed rescaled method can evaluate reserve in a convenient and accurate way. Results show that the proposed modification of the original rescaled exponential approach can successfully predict the production of CBM reservoirs compared with the results of commercial numerical simulator (GEM-CMG) and production data of the field cases on the condition of constant bottom hole pressure.
Comparative Study of Various Constant-Pressure Compressed Air Energy Storage Systems Based on Energy and Exergy Analysis
Authors: Mazloum Youssef , Sayah Haytham , Nemer Maroun 
Published: September 2020

Abstract
The balance between supply and demand for electricity is mainly disrupted by the growing contribution of renewable energy sources to the electrical grid since these sources are intermittent by nature. Therefore, the energy storage systems, mainly those of considerable size, become essential to restore the electricity balance. The compressed air energy storage (CAES) system is one of the mature technologies used to store electricity on a large scale. Therefore, this article discusses the energy and exergy analysis of different configurations of a constant-pressure CAES system to improve its overall efficiency and energy density. The exergy efficiency of our basic adiabatic configuration using water as thermal storage medium is 56.4% and the energy density is 12.17 kWh/m3. The results show that the CAES system using a packed bed of quartzite rock as thermal storage medium has the best efficiency (67.2%) and energy density (17 kWh/m3) among adiabatic systems. The diabatic CAES systems could have a net efficiency up to 70.1% and an energy density up to 31.95 kWh/m3 by using combustion chambers. Finally, the waste heat recovery from other installations such as a gas turbine power plant has the potential to improve the energy density to 20.53 kWh/m3 without using fossil fuel sources.
Numerical Investigation of the Plasma-Assisted MILD Combustion of a CH4/H2 Fuel Blend Under Various Working Conditions
Authors: Mousavi Seyed Mahmood , Kamali Reza , Sotoudeh Freshteh , Karimi Nader , Lee Bok Jik 
Published: September 2020

Abstract
The effects of plasma injection upon MILD combustion of a mixture of methane and hydrogen are investigated numerically. The injected plasma includes the flow of a highly air-diluted methane including C2H2, C2H4, C2H6, CH, CH2, CH3, CO, and CO2. The results show that among all the constitutes of plasma, CH3 is the most effective in improving the characteristics of MILD combustion. Injection of this radical leads to the occurrence of reactions at a closer distance to the burner inlet and thus provides longer time for completion of combustion. Further, mass fractions of OH, CH2O, and HCO are considerably affected by the injections of CH3, indicating structural modifications of the reacting flow. Importantly, as Reynolds number of the plasma flow increases, the volume and width of the flame decrease, while the formations of prompt and thermal NOx are intensified. However, injection of CH3, as plasma, reduces the emission of thermal NOx.
The Effect of Dissolved Cavern on the Fracture Propagation in Vuggy Carbonate Reservoir
Authors: Guo Tiankui , Tang Songjun , Li Yanchao , Zhou Fujian , Tan Bijun , Qu Zhanqing , Ling Kegang 
Published: September 2020

Abstract
The acid-fracturing is applied wildly to simulate the formation in vuggy carbonate reservoirs. But it does not figure out clearly the mechanism of fracture propagation while fracture encountering dissolved cavern, and there are few researches considering the influence of dissolved cavern on fracture propagation. In order to study fracture propagation regularity in vuggy carbonate reservoirs, numerical simulations are carried out by the seepage–stress–damage coupling equation based on the damage mechanics theory and the accuracy of the model is validated by comparison with experimental results. Some factors influencing the fracture propagation such as dissolved cavern, formation parameters, and construction parameters are considered. The simulation results show that there are four fracture propagation forms after the fracture encountering dissolved cavern, namely, block, crossing over directly, crossing over after deflection, and deflection. The entire process of injecting the pressure curve can be divided into five stages: initial initiation zone, encountering dissolved cavern pressure released zone, the dissolved cavern inside builds the pressure zone, re-ruptured zone, and fracture propagation zone. The horizontal principal stress difference of the formation controls the tendency of fracture propagation and the generation of branch fractures. It is easy to generate branch fractures under the condition of low horizontal principal stress. The increase in horizontal principal stress limits the deformation of fracture, making it more convenient for fracture to extend toward the maximum horizontal principal stress. The study results are significant for optimizing fracturing construction plans and improving the probability of connection between fracture and dissolved cavern.
A New Low-Damage Drilling Fluid for Sandstone Reservoirs With Low-Permeability: Formulation, Evaluation, and Applications
Authors: Wang Chengwen , Wang Yanji , Kuru Ergun , Chen Erding , Xiao Fengfeng , Chen Zehua , Yang Daoyong 
Published: September 2020

Abstract
Drilling-induced formation damage is the key factor dominating the failure of the development of hydrocarbon reservoirs with low-permeability (i.e., tight formation). In this paper, a new low-damage drilling fluid was formulated, evaluated, and applied to well-drilling operations in a sandstone oil reservoir with low-permeability in the Shengli Oilfield, China. To formulate this low-damage drilling fluid, filter-cake forming agents were used to prevent fluid loss, inhibitors were used to enhance the shale inhibition of the fluid, surfactants were used to minimize water block, and inorganic salts were used to enhance compatibility. A holistic experimental approach combining micro-computed tomography (CT), scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FT-IR), and X-ray diffraction (XRD) techniques was designed to identify the underlying interactions between new and conventional drilling fluids and rock samples as well as the corresponding damage mechanisms, demonstrating the significant mitigation effects of the newly formulated drilling fluid on formation damage, which mainly results from the hydration of clay minerals and the invasion of solid particles. The newly formulated low-damage drilling fluid then extended its applications to well-drilling operations with excellent performance. Not only can the new low-damage drilling fluid avoid non-fracturing stimulation, but also reduce the drilling operational costs and time, minimize the formation damage, and facilitate extending the reservoir life for a longer time.
Lifetime visual outcomes of patients undergoing trabeculectomy
Authors: Chen Ruth , King Anthony J 
Published: September 2020

Background
The most important outcome for patients undergoing trabeculectomy is to maintain the quality of life in their remaining years. This study quantifies end of life vision in terms of visual acuity (VA) and visual field status.

Methods
A prospective service evaluation of patients undergoing trabeculectomy (from 2000 to 2012) who died prior to the study evaluation point (November 2018). Demographic data including socioeconomic status were collected and change in clinical measurement for the cohort between time of surgery and death was measured.

Results
160 of 659 patients had died (24.3%), 4 were excluded due to insufficient data, leaving 156 patients (196 eyes) for evaluation. Male-to-female ratio was 3:2, 86% of patients were Caucasian. Mean age at surgery on first eye was 76.5 years (SD 9.0). Life expectancy post-trabeculectomy was 7.5 years (0.1–17.2). Mean change in VA was logarithm of the mean angle of resolution (LogMAR) 0.32 (SD 0.59) and visual field mean deviation progressed at a median of −0.44 dB/year (from −5.98 to 3.9) for eyes with at least a year of follow-up. Severe vision loss (loss of ≥10 letters on LogMAR) occurred in 78 eyes (40%) of which 18 (9%) were due to glaucoma, 69 patients (44%) required glaucoma drops at end of life.

Conclusion
Trabeculectomy is successful in slowing or preventing further glaucoma progression and thus maintaining visual function in the majority of eyes for the remainder of life. For those with severe vision loss at the end of life, only one in four was due to further progression of their glaucoma.
Impact of intraocular lens characteristics on intraocular lens dislocation after cataract surgery
Authors: Mayer-Xanthaki Christoph Fidel , Pregartner Gudrun , Hirnschall Nino , Falb Thomas , Sommer Michael , Findl Oliver , Wedrich Andreas 
Published: September 2020

Background
To assess the influence of intraocular lens (IOL) characteristics on IOL dislocations after cataract surgery.

Methods
Patients who underwent cataract surgery at the Department of Ophthalmology Graz, Austria, between 1996 and 2017 were included and medical records were reviewed. Cox proportional-hazard regression models were used to assess the influence of IOL characteristics on IOL dislocation.

Results
From 68 199 eyes out of 46 632 patients (60.2% women, mean age: 73.71 SD±10.82 years), 111 (0.16%) had an in-the-bag (ITB) disloaction and 35 (0.05%) had an out-of-the-bag (OTB) dislocation. The HRs adjusted for predisposing factors significantly associated with a higher risk for an ITB dislocation were 2.35 (95% CI, 1.45 to 3.8) for hydrophilic IOLs, 2.01 for quadripode IOLs (95% CI, 1.04 to 3.86) and 1.61 (95% CI, 1.04 to 2.48) for haptic angulation. A lower risk was observed for three-piece IOLs (HR=0.58, 95% CI, 0.34 to 0.98) and larger overall IOL diameter (HR=0.79, 95% CI, 0.66 to 0.95). For an OTB dislocation, the HR associated with a higher risk was 18.81 (95% CI, 5.84 to 60.58) for silicone IOLs and 2.12 (95% CI, 0.62 to 7.29) for hydrophilic IOLs. Larger overall IOL diameter (HR 0.40, 95% CI; 0.25 to 0.63) showed a lower risk.

Conclusion
Hydrophilic IOLs, quadripode IOLs and haptic angulation were associated with a higher risk for an ITB dislocation, whereas three-piece IOLs and a larger overall diameter were associated with a lower risk. Risk factors for OTB dislocation were silicone IOLs, hydrophilic IOLs and a smaller overall IOL diameter.
Drug retention, inactive disease and response rates in 1860 patients with axial spondyloarthritis initiating secukinumab treatment: routine care data from 13 registries in the EuroSpA collaboration
Authors: Michelsen Brigitte , Lindström Ulf , Codreanu Catalin , Ciurea Adrian , Zavada Jakub , Loft Anne Gitte , Pombo-Suarez Manuel , Onen Fatos , Kvien Tore K , Rotar Ziga , Santos Maria Jose , Iannone Florenzo , Hokkanen Anna-Mari , Gudbjornsson Bjorn , Askling Johan , Ionescu Ruxandra , Nissen Michael J , Pavelka Karel , Sanchez-Piedra Carlos , Akar Servet , Sexton Joseph , Tomsic Matija , Santos Helena , Sebastiani Marco , Österlund Jenny , Geirsson Arni Jon , Macfarlane Gary , van der Horst-Bruinsma Irene , Georgiadis Stylianos , Brahe Cecilie Heegaard , Ørnbjerg Lykke Midtbøll , Hetland Merete Lund , Østergaard Mikkel 
Published: September 2020

ObjectivesTo explore 6-month and 12-month secukinumab effectiveness in patients with axial spondyloarthritis (axSpA) overall, as well as across (1) number of previous biologic/targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs), (2) time since diagnosis and (3) different European registries.MethodsReal-life data from 13 European registries participating in the European Spondyloarthritis Research Collaboration Network were pooled. Kaplan-Meier with log-rank test, Cox regression, χ² and logistic regression analyses were performed to assess 6-month and 12-month secukinumab retention, inactive disease/low-disease-activity states (Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) <2/<4, Ankylosing Spondylitis Disease Activity Score (ASDAS) <1.3/<2.1) and response rates (BASDAI50, Assessment of Spondyloarthritis International Society (ASAS) 20/40, ASDAS clinically important improvement (ASDAS-CII) and ASDAS major improvement (ASDAS-MI)).ResultsWe included 1860 patients initiating secukinumab as part of routine care. Overall 6-month/12-month secukinumab retention rates were 82%/72%, with significant (p<0.001) differences between the registries (6-month: 70–93%, 12-month: 53–86%) and across number of previous b/tsDMARDs (b/tsDMARD-naïve: 90%/84%, 1 prior b/tsDMARD: 83%/73%, ≥2 prior b/tsDMARDs: 78%/66%). Overall 6-month/12-month BASDAI<4 were observed in 51%/51%, ASDAS<1.3 in 9%/11%, BASDAI50 in 53%/47%, ASAS40 in 28%/22%, ASDAS-CII in 49%/46% and ASDAS-MI in 25%/26% of the patients. All rates differed significantly across number of previous b/tsDMARDs, were numerically higher for b/tsDMARD-naïve patients and varied significantly across registries. Overall, time since diagnosis was not associated with secukinumab effectiveness.ConclusionsIn this study of 1860 patients from 13 European countries, we present the first comprehensive real-life data on effectiveness of secukinumab in patients with axSpA. Overall, secukinumab retention rates after 6 and 12 months of treatment were high. Secukinumab effectiveness was consistently better for bionaïve patients, independent of time since diagnosis and differed across the European countries.
Echoes of 2HDM inflation at the collider experiments
Authors: Modak Tanmoy , Oda Kin-ya 
Published: September 2020

AbstractWe study the correlation between the constraints on general two Higgs doublet model from Higgs inflation and from collider experiments. The parameter space receives meaningful constraints from direct searches at the large hadron collider and from flavor physics if $$m_H$$

m
H

, $$m_A$$

m
A

, and $$m_{H^\pm }$$

m

H
±

are in the sub-TeV range, where H, A, and $$H^\pm $$

H
±

are the CP even, CP odd, and charged Higgs bosons, respectively. We find that in the parameter region favored by the Higgs inflation, H, A, and $$H^\pm $$

H
±

are nearly degenerate in mass. We show that such near degeneracy can be probed directly in the upcoming runs of the Large Hadron Collider, while the future lepton colliders such as the International Linear Collider and the future circular collider would provide complementary probes.
The global geometrical property of jet events in high-energy nuclear collisions
Authors: Chen Shi-Yong , Dai Wei , Zhang Shan-Liang , Zhang Qing , Zhang Ben-Wei 
Published: September 2020

AbstractWe present the first theoretical study of medium modifications of the global geometrical pattern, i.e., transverse sphericity ($$S_{\perp }$$

S
⊥

) distribution of jet events with parton energy loss in relativistic heavy-ion collisions. In our investigation, POWHEG + PYTHIA is employed to make an accurate description of transverse sphericity in the p + p baseline, which combines the next-to-leading order (NLO) pQCD calculations with the matched parton shower (PS). The Linear Boltzmann Transport (LBT) model of the parton energy loss is implemented to simulate the in-medium evolution of jets. We calculate the event normalized transverse sphericity distribution in central Pb + Pb collisions at the LHC, and give its medium modifications. An enhancement of transverse sphericity distribution at small $$S_{\perp }$$

S
⊥

region but a suppression at large $$S_{\perp }$$

S
⊥

region are observed in A + A collisions as compared to their p + p references, which indicates that in overall the geometry of jet events in Pb + Pb becomes more pencil-like. We demonstrate that for events with 2 jets in the final-state of heavy-ion collisions, the jet quenching makes the geometry more sphere-like with medium-induced gluon radiation. However, for events with $$\ge 3$$

≥
3

jets, parton energy loss in the QCD medium leads to the events more pencil-like due to jet number reduction, where less energetic jets may lose their energies and then fall off the jet selection kinematic cut. These two effects offset each other and in the end result in more jetty events in heavy-ion collisions relative to that in p + p.
Parallelism in Randomized Incremental Algorithms
Authors: Blelloch Guy E. , Gu Yan , Shun Julian , Sun Yihan 
Published: September 2020

In this article, we show that many sequential randomized incremental algorithms are in fact parallel. We consider algorithms for several problems, including Delaunay triangulation, linear programming, closest pair, smallest enclosing disk, least-element lists, and strongly connected components.
We analyze the dependencies between iterations in an algorithm and show that the dependence structure is shallow with high probability or that, by violating some dependencies, the structure is shallow and the work is not increased significantly. We identify three types of algorithms based on their dependencies and present a framework for analyzing each type. Using the framework gives work-efficient polylogarithmic-depth parallel algorithms for most of the problems that we study.
This article shows the first incremental Delaunay triangulation algorithm with optimal work and polylogarithmic depth. This result is important, since most implementations of parallel Delaunay triangulation use the incremental approach. Our results also improve bounds on strongly connected components and least-element lists and significantly simplify parallel algorithms for several problems.
Fundamental elements of constant volt/hertz induction motor drives based on dSPACE DS1104 controller
Authors: Mahsahirun Siti Nursyuhada , Nik Idris Nik Rumzi , Yusof Zulkifli Md. , Sutikno Tole 
Published: September 2020

An induction motor (IM) has been the workhorse of the industry for decades. It is due to its robustness, simple construction, requiring less maintenance and cheap. One of the most widely adopted IM drive control schemes for industrial applications is the open-loop constant V/Hz. In this paper, the important elements of an open-loop constant V/Hz drives are presented. These include the fundamental concept of a constant V/Hz scheme, the voltage source inverter (VSI) and its modulation schemes. Techniques that are commonly used to solve problems of low-speed operation and rotor speed regulation are briefly described. Simulations using MATLAB/Simulink package are used to help in illustrating these fundamental concepts. Finally, simple laboratory-scale experiments are conducted to implement the constant V/Hz control scheme on a ¼ hp induction motor. The constant V/Hz control is implemented using the DS1104 controller board with the C codes automatically generated from the Simulink model. A closer look at the current waveform when fref=25 Hz and 12 Hz and its respective Fourier analysis are presented. The results show that the high-frequency harmonic contents around the switching frequency can be observed for both cases, and the voltage waveform presents more spike noises in constrast to current waveform.
Robust non-linear control of a hybrid water pumping system based on induction motor
Authors: Massaq Zakaria , Abounada Abdelouahed , Ramzi Mohamed 
Published: September 2020

This contribution presents a non-linear control of a hybrid pumping system supplied with a photovoltaic generator and a battery. This system is employed for delivering a continuous volume of water whatever the climatic conditions. In the DC side, a boost converter is controlled with the indirect double integral sliding mode controller (DISMC) for maximum power point tracking (MPPT). The DISMC is suitable for MPPT because it gives a fast response and reduces the amplitude of power oscillations. Then, a bidirectional buck-boost converter is adopted to ensure the energy management between the battery and the DC-bus, and this converter is controlled with integral sliding mode control (ISMC) theory. The non-linear predictive control (NPC) is chosen to drive an induction motor (IM), the NPC is known by its fast dynamic and high capacity to reject disturbances. The hybrid system is modelled in MATLAB/Simulink software. During simulations, the DISMC-MPPT is compared with other techniques such as sliding mode controller (SMC) MPPT and integral SMC MPPT, the DISMC provides the best tracking performances under different irradiances. Moreover, the designed controller for the bidirectional converter regulates the DC-link voltage with better performances than the classical PI controller. Lastly, the NPC regulates the speed of the IM with high robustness.