bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancement of Dry Sliding Tribological Characteristics of Perforated Zirconia Toughened Alumina Ceramic Composite Filled With Nano MoS2 in High Vacuum
Authors: Ghosh Kunal , Mazumder Subhrojyoti , Hirani Harish , Roy Poulomi , Mandal Nilrudra
Published: September 2020

An innovative approach was adopted for fabricating zirconia toughened alumina (ZTA)-MoS2 self-lubricating ceramic composites with the inclusion of hydrothermally synthesized nano MoS2 through the micropores of perforated ZTA ceramics. This method avoided the exposure of MoS2 in high-temperature environment due to its in-sensitiveness during traditional sintering techniques. Different weight percentages (wt%: 0, 5, 10, and 15) of graphite were incorporated to produce porous ZTA ceramics with the help of cold press sintering followed by insertion of nano MoS2 into the matrices. Best tribological characteristics were obtained with 10 wt% graphite-ZTA-MoS2 specimen which offered an improvement of ∼66% in coefficient of friction (COF) and ∼96% in specific wear rate when dry sliding tests were carried out against silicon nitride (Si3N4) in high vacuum (5.0 × 10−4 mbar). Nano MoS2 was sheared off at the contacting interface during sliding under load which showed a good tribological characteristics of the composite. Delamination was found as the dominating wear mechanism in ZTA-MoS2 composites during wear tests.
A Transient Mixed Elastohydrodynamic Lubrication Model for Helical Gear Contacts
Authors: Chimanpure A. S. , Kahraman A. , Talbot D.
Published: September 2020

In this study, a non-Newtonian, transient, isothermal, mixed elastohydrodynamic lubrication (EHL) model is proposed for helical gear contacts. The model accounts for nonelliptical contacts subject to spatially varying sliding and rolling velocity fields that are not aligned with any principal axis of the contact region, which is the case for helical gear contacts. The time-varying changes pertaining to key contact parameters and relative motion of roughness profiles on mating tooth surfaces are captured simultaneously to follow the contact from the root to the tip of a tooth while accounting for the transient effect due to relative motions of the roughness profiles. Actual tooth load distributions, contact kinematics, and compliances of helical gear contacts are provided to this model by an existing helical gear load distribution model. Measured three-dimensional roughness profiles covering the entire meshing zone are incorporated in the analyses to investigate its impact on the EHL conditions as well as mechanical power loss. Results of a parametric sensitivity study are presented to demonstrate the influence of operating conditions and surface roughness on the EHL behavior and the resultant gear mesh mechanical power loss of an example helical gear pair. The accuracy of the proposed mixed-EHL model is assessed by comparing the mechanical power loss predictions to available experimental results.
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

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

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

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

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

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

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

Objectives

To 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.

Methods

Real-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)).

Results

We 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.

Conclusions

In 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

We 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

We 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.
Acrophobia Quantified by EEG Based on CNN Incorporating Granger Causality
Authors: Hu Fo , Wang Hong , Wang Qiaoxiu , Feng Naishi , Chen Jichi , Zhang Tao
Published: September 2020

The aim of this study is to quantify acrophobia and provide safety advices for high-altitude workers. Considering that acrophobia is a fuzzy quantity that cannot be accurately evaluated by conventional detection methods, we propose a comprehensive solution to quantify acrophobia. Specifically, this study simulates a virtual reality environment called High-altitude Plank Walking Challenge, which provides a safe and controlled experimental environment for subjects. Besides, a method named Granger Causality Convolutional Neural Network (GCCNN) combining convolutional neural network and Granger causality functional brain network is proposed to analyze the subjects’ noninvasive scalp EEG signals. Here, the GCCNN method is used to distinguish the subjects with severe acrophobia, moderate acrophobia, and no acrophobia in a three-class classification task or no acrophobia and acrophobia in a two-class classification task. Compared with the mainstream methods, the GCCNN method achieves better classification performance, with an accuracy of 98.74% for the two-class classification task (no acrophobia versus acrophobia) and of 98.47% for the three-class classification task (no acrophobia versus moderate acrophobia versus severe acrophobia). Consequently, our proposed GCCNN method can provide more accurate quantitative results than the comparative methods, making it to be more competitive in further practical applications.
Comparative study between a discrete vortex method and an immersed boundary–lattice Boltzmann method in 2D flapping flight analysis
Authors: Suzuki Kosuke , Kato Takeshi , Tsue Kotaro , Yoshino Masato , Denda Mitsunori
Published: September 2020

Numerical analysis of the flapping flight of insects has attracted great attention because of the expectation for insect-inspired micro air vehicles. A lot of numerical methods for the insect flight have been proposed, and they can be classified into two categories: inviscid flow solvers and viscous flow solvers. The discrete vortex method (DVM) has been regarded as a successful method in the first category, and the immersed boundary–lattice Boltzmann method (IB-LBM) has recently been developed as an efficient method in the second category. However, a detailed comparative study between these methods has not been sufficiently performed. In this study, we compare the DVM with the IB-LBM in two-dimensional flapping flight analysis. As a result, it is found that the aerodynamic forces obtained by the DVM are comparable to those by the IB-LBM, when the effect of separated vortices is not so accumulated, and when the forward speed of the model is smaller than the flapping speed. In addition, the DVM has a difficulty in estimating the aerodynamic torque. In terms of the computational time, the DVM is much faster than the IB-LBM. This result suggests that the DVM can be used for massive parametric studies or optimizations in flapping flight analysis, although there remain many issues in its accuracy.
Study on the electron mobility related with ohmic contact width in AlGaN/GaN HEMTs
Authors: Yang Ming , Ji Qizheng , Su Xinguang , Zhang Weihong , Wang Yuanyuan , Wang Lei , Hu Xiaofeng , Yuan Qingyun , Feng Peiyuan , Liu Yang
Published: September 2020

For the fabricated AlGaN/GaN high electron mobility transistors (HEMTs) with different Ohmic contact widths, the gate-channel electron mobility is obtained experimentally. Mobility curves show very different values and trends. This phenomenon is investigated with the scattering theory in AlGaN/GaN HEMTs. The reason for the different mobility curves is found to be attributed to the different polarization charge distributions at the AlGaN/GaN interface. The AlGaN/GaN HEMT with a smaller Ohmic contact width corresponds to positive additional polarization charge near the Ohmic contact. The AlGaN/GaN HEMT with a larger Ohmic contact width corresponds to negative additional polarization charge near the Ohmic contact. Changing the Ohmic contact width will be a new dimension to optimize the characteristics of AlGaN/GaN HEMTs effectively.
Geometric phase for “dark” subspaces in coherent population trapping
Authors: Yakovleva T. S. , Rostom A. M. , Tomilin V. A. , Il’ichov L. V.
Published: September 2020

The concept of geometric phase acquired by a quantum state during its evolution is generalized to the subspace of states of evolving quantum system. Physical motivation of this generalization comes from the effect of coherent population trapping. Under certain conditions, there exists a two-dimensional “dark” subspace of atomic ground states that does not interact with the external radiation. The structure of this “dark” subspace depends on the local field amplitude. We show that certain mathematical difficulties in finding the geometric phase for “dark” subspaces can be circumvented with the help of the orthogonal “bright” subspace.
Braille and Morse Code Based Tactile Information Coding and its Applications
Authors: Huang Wenbo , Wang Changyuan , Jia Hongbo
Published: September 2020

Tactile sensing has recently been used in pattern recognition technology for pilots’ posture information and environmental information. Human tactile sensing is limited, however, through control of the spatial distribution and vibration intensity of each contact in the tactile stimulation array, the accuracy, convenience, and comfort of the tactile device can be comprehensively improved. Moreover, the recognition rate of most current flight posture information methods is low. In this paper, the principle of vibration haptic coding is optimized. A combined coding scheme of “vibration [Formula: see text] sequence” is used to recognize pilot’s flight posture. A novel triangular coding scheme is proposed for the first time. Compared to other commonly used coding schemes such as “needle scheme“ and “rectangle scheme”, experimental results show that the triangular coding scheme is 1.5% more accuracy with response time reduced by nearly 1.25s in recognition pilots’ flight posture information.
Delay-Sensitive Network Selection and Offloading in LTE-A and Wi-Fi Heterogeneous Networks
Authors: Yang Chun-Chuan , Chen Jeng-Yueng , Mai Yi-Ting , Wang Yi-Chih
Published: September 2020

LTE-Advanced (LTE-A) offloading is concerned about alleviating traffic congestion for the LTE-A network, which includes the core network and the radio access network (RAN). Due to the scarcity of the radio resource, offloading for the LTE-A RAN is more critical, for which an efficient way is to integrate Wi-Fi with LTE-A to form a heterogeneous RAN environment. An LTE-A UE (User Equipment) with the wi-fi interface can therefore access the Internet via an LTE-A base station of Evolved Node B (eNB) or a wi-fi Access Point (AP). In this paper, wireless network selection for UEs with delay-sensitive traffic in the heterogeneous RAN of LTE-A and wi-fi is addressed. Based on the queueing model of M/G/1, a novel network selection and offloading scheme, namely Delay-Sensitive Network Selection and Offloading (DSO), is proposed. The average system time at LTE-A eNBs and wi-fi APs calculated according to M/G/1 is used for network selection as well as offloading operations in DSO. The benefit of DSO in terms of satisfying the delay budget of UEs and load balancing is demonstrated by the simulation study.
Frequency-Compensated Bulk-Driven TIA Suitable for Low-Voltage Low-Power Applications
Authors: Bansal Urvashi , Gupta Maneesha , Raj Niranjan
Published: September 2020

The importance of a transimpedance amplifier in an optical transceiver is very well known. In this paper, a novel CMOS design of the bulk-driven transimpedance amplifier (BD-TIA) is given where the bridge-shunt peaking-based frequency compensation technique is exploited to improve frequency response. A pre-existing active inductor has been used for the same. The electrical characteristics and functioning of this inductor simulator make it a suitable alternative to both floating and grounded spiral inductors. In order to verify the workability of the proposed circuit, it has been simulated with TSMC CMOS 0.18[Formula: see text][Formula: see text]m process parameters. The proposed circuit is useful in low-voltage low-power VLSI applications as it uses a single supply of 0.75[Formula: see text]V. The power consumption of BD-TIA is very low, being 0.37[Formula: see text]mW, because a standard MOSFET has been replaced by a bulk-driven MOSFET (BDMOS), while the 3-dB bandwidth is observed to be 4.5[Formula: see text]GHz. The mathematical investigation and small signal analysis show that the simulation results are in good agreement.
SUPERWETTABILITY-BASED CHEMICAL PROCESSES
Authors: WANG SHA-SHA , JIN LING-ZHI , YU XIANG , XING ZHOU-HAO
Published: September 2020

The special wettability of surfaces has attracted intensive research interests and leads to a rapidly developing field collectively known as the “superwettability” system. As a new member of this system, superwettability-based chemical processes advance the applications of superwettability from single surface functions to a broader space. This review briefly introduces the latest developments in this field, including superwettability-based miniature reactors, highly effective catalytic electrodes, gaseous reactant channels and solid/liquid/gas triphase edge-growth. The reaction types cover electrochemical reaction, polymerization, crystal precipitation and catalytic process. We believe there are abundant unimaginable possibilities along with challenges in this newly emerging promising field. We hope this review will inspire researchers with different backgrounds to use superwettability concept in their reaction systems flexibly and provide a new exploitation for the superwettability system.
PARTICLE SHAPE-INDUCED CORRELATION EFFECT IN RANDOM DEPOSITION IN 1+1 DIMENSION AND RELATED EFFECT IN BALLISTIC DEPOSITION
Authors: DAS S. K. , BANERJEE D. , ROY J. N.
Published: September 2020

This work is a systematic computational study of random and ballistic deposition (BD) in 1+1 dimension for deposition of two differently shaped particles. The effect of particle shape and size on different growth parameters has been reported. It has been observed that when the shape of the particle gets changed, the surface that evolves following the mechanism of random deposition (RD) model shows acute correlation effect. The growth appeared with two regions along with saturation with two acutely different slopes, one of which is around 0.5 and, other is nearly 0.33. This shows that initially, the deposition obeys the RD model, while when particle shape changes correlation gets introduced, the deposition mechanism obeys the law of BD. Same when applied in the case of BD, it had been observed that introduction of this artificial correlation introduces another region in the growth regime separating the entire regime into three parts along with saturation. In each case, different critical exponents were calculated along with the other associated parameters like porosity, growth velocity, etc. Also, it has been shown that porosity has profound effect on size and shape of the particle deposited and it varies between 0 and 0.5 for the surfaces evolved by RD model whereas the same has value between 0.75 and 0.6 in the case of BD.
EFFECTS OF ELECTRODE DISTANCE ON MECHANICAL AND TRIBOLOGICAL PROPERTIES OF HYDROGENATED DLC FILMS DEPOSITED BY DC-PULSE PECVD
Authors: WU KUN-YAO , ZHAO GENG-RUI , LI ZHAO , GONG ZHEN-BIN
Published: September 2020

Hydrogenated diamond-like carbon (DLC) films were deposited by DC-pulse plasma-enhanced chemical vapor deposition (PECVD) under the different electrode distances. Effects of the electrode distances on the microstructural, mechanical, and tribological properties of the obtained films were investigated by high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), Raman spectrum, Fourier transform infrared spectroscopy (FTIR), nano-indenter, and reciprocating ball-on-disc tester, respectively. The results indicate that the thickness of the films decreased with the increased electrodes distances. The films have the highest internal stress, highest hydrogen concentration, and lowest friction coefficient at the 54[Formula: see text]mm electrode distance, which are resulted from the highest sp3 content formed at this feature distance. The wear rates also have similar variations. The film formed at 54[Formula: see text]mm distance also shows the lowest hardness and elastic modulus with values of 6.2 and 29.1[Formula: see text]GPa.
Mechanical Analysis of Functionally Graded Porous Structures: A Review
Authors: Wu Helong , Yang Jie , Kitipornchai Sritawat
Published: September 2020

Functionally graded porous structures (FGPSs), characterized by a continuous spatial gradient in both porosity and material properties, have been considered as the new generation lightweight structures. Research activities on FGPSs have grown rapidly in recent years. This paper is devoted to review the existing research works on FGPSs and to highlight the important advances in this emerging area. It consists of: (i) a brief introduction of porous materials and Functionally graded porous materials (FGPMs); (ii) an elaboration of the key factor and micromechanical models related to material properties of FGPMs; (iii) a comprehensive review of mechanical analysis of FGPSs; (iv) a detailed discussion of the main challenges and future research directions; (v) a conclusion.
Medial and semimedial left quasigroups
Authors: Bonatto Marco
Published: September 2020

In this paper, we investigate the class of semimedial left quasigroups, a class that properly contains racks and medial left quasigroups. We extend most of the results about commutator theory for racks collected in [M. Bonatto and D. Stanovský, Commutator theory for racks and quandles, preprint (2019), arXiv:1902.08980.] and we provide a structure theorem for finite medial connected racks.
Process Optimization of Curcumin-Loaded Coconut Oil and Honey Nanoemulsion for Better Skin Permeation
Authors: Md Saari Nur Hulwani , Chua Lee Suan , Hasham Rosnani
Published: September 2020

This study was focused on the optimization of preparing a curcumin-loaded coconut oil and honey nanoemulsion using a low energy emulsifying technique. Curcumin is a bioactive compound with low bioavailability and stability. Response surface methodology (RSM) with Box Behnken design was used to optimize the base formulation based on the three independent variables such as honey (1–3%), virgin coconut oil (1.0–1.5%) and Tween 80 (5.0–9.0%) to obtain low particle size (10.11[Formula: see text]nm), polydispersity index (0.27) and turbidity (0.24–1.11) system. Subsequently, the second optimization was carried out after curcumin was loaded into the base formulation. Another three independent variables such as polyethelene glycol (0.8–1.5%), curcumin (0.01–0.1%) and honey (1.8–2.4%) were used to produce the nanorange of particle size (14.32[Formula: see text]nm), narrow polydispersity index (0.152), and high encapsulation efficiency (98.0%). The curcumin-loaded nanoemulsion was found to have high stability with only 8.5% increment in particle size after storage for three months at 4∘C and 45∘C. The radical scavenging activity of encapsulated curcumin in nanoemulsion was decreased ([Formula: see text]%) compared to free curcumin. Nanoemulsion appeared to increase in vitro release rate of curcumin by about 42%, especially for the first 2[Formula: see text]h in Franz diffusion cell using rat skin.
Catalytic Vapor Phase Oxidation of Glycerol to Glyceric Acid Over Activated Carbon Supported Gold Nanocatalysts
Authors: Kumar Ashish , Belwal Mamta , Mohan Varun , Maurya Radha Raman , Vishwanathan Venkataraman
Published: September 2020

A series of activated carbon (AC) supported Au nanocatalysts with different loadings of Au were prepared by using the homogeneous deposition–precipitation (HDP) method. The samples were characterised with myriad techniques such as X-ray diffraction (XRD), CO-chemisorption, N2 adsorption–desorption measurements, transmission electron microscopy (TEM), inductively coupled plasma-optical emission spectrometer (ICP-OES) and X-ray photoelectron spectroscopy (XPS) to understand the structural and textural properties in detail. The catalysts were tested for the vapour phase oxidation of glycerol to glyceric acid under base-free medium in an aerobic condition at normal atmospheric pressure. The Au/AC nanocatalysts with smaller size Au particles ([Formula: see text][Formula: see text]nm) showed higher glycerol conversion and selectivity for glyceric acid, and also a longer catalyst life. While the larger Au particles ([Formula: see text][Formula: see text]nm) showed less activity and selectivity. Among all the nanocatalysts tested, the 1.0[Formula: see text]wt.% Au/AC sample having smaller particle size of Au showed the best catalytic performance in terms of glycerol conversion and glyceric acid selectivity. These results suggest that the oxidation activities of Au/AC nanocatalysts are strongly influenced by the size of Au nanoparticle, nature of the support material and through a metal-support interaction.
An enhanced particle swarm optimization with distribution fields appearance model for object tracking
Authors: Hu Quanyi , Qin Peng , Yang Jie , Fong Simon
Published: September 2020

This paper presents an improved Particle Swarm Optimization tracker, representing target with Distribution Fields (DFs) to solve problems of how to effectively represent the appearance model and adapt to the change of environment. First, Categorized Particle Swarm Optimization (CPSO) makes good use of identifying selected object model by integrating based on the performance of categorized particles and it achieves an efficient algorithm in object tracking. Then, compared with the traditional target representation such as color, gradient, filter responses, etc. DFs build image descriptors that are able to make object smoothing and keep pixel values. To provide a better tracking result in different videos, this paper finds a more efficient way by using an appearance model which adopts the DFs layer with CPSO to build tracking procedure. The experiments show higher performances than another four state-of-the-art approaches on several sequences videos.
Matching Co-innovation Project Types to Diverse Customer Relationships: Perspective of an Industrial Technology Supplier
Authors: Lehtimäki Tuula , Komulainen Hanna
Published: September 2020

Co-innovation between suppliers and their customers provides important benefits but is not without challenges. Especially in technologically complex industrial context co-innovation projects need careful planning and preparing. Through eight cases, this qualitative study takes the perspective of the supplier and empirically identifies three types of supplier-customer co-innovation projects and for each project type, the supplier’s co-innovation goal, potential matching customer relationships, and related managerial benefits and challenges are described. The results contribute to the co-innovation research by presenting a framework for matching supplier’s co-innovation goals to customer relationship types, which brings out the variety of co-innovation projects that even a single supplier can face and must manage.
The restrained k-rainbow reinforcement number of graphs
Authors: Shaebani Saeed , Kosari Saeed , Asgharsharghi Leila
Published: September 2020

Let [Formula: see text] be a positive integer and [Formula: see text] be a simple graph. A restrained[Formula: see text]-rainbow dominating function (R[Formula: see text]RDF) of [Formula: see text] is a function [Formula: see text] from the vertex set [Formula: see text] to the family of all subsets of [Formula: see text], such that every vertex [Formula: see text] with [Formula: see text] satisfies both of the conditions [Formula: see text] and [Formula: see text] simultaneously, where [Formula: see text] denotes the open neighborhood of [Formula: see text]. The weight of an R[Formula: see text]RDF is the value [Formula: see text]. The restrained[Formula: see text]-rainbow domination number of [Formula: see text], denoted by [Formula: see text], is the minimum weight of an R[Formula: see text]RDF of [Formula: see text]. The restrained[Formula: see text]-rainbow reinforcement number [Formula: see text] of [Formula: see text], is defined to be the minimum number of edges that must be added to [Formula: see text] in order to decrease the restrained [Formula: see text]-rainbow domination number. In this paper, we determine the restrained [Formula: see text]-rainbow reinforcement number of some special classes of graphs. Also, we present some bounds on the restrained [Formula: see text]-rainbow reinforcement number of general graphs.
Codes from incidence matrices of some Bouwer graphs
Authors: Saranya R. , Durairajan C.
Published: September 2020

We examine the [Formula: see text]-ary linear codes from incidence matrix of the Bouwer graph [Formula: see text] with vertex set [Formula: see text] and two vertices are adjacent if they can be written as [Formula: see text] and [Formula: see text] where either [Formula: see text] or [Formula: see text] differs from [Formula: see text] in exactly one position, say the [Formula: see text]th position, where [Formula: see text] All the main parameters of the codes are obtained as [Formula: see text] Also, we determine linear codes from incidence matrices of Bouwer graphs [Formula: see text] and all the main parameters of the codes are obtained as [Formula: see text] All the above codes can be used for full error correction by permutation decoding.
Analysis of statistical dependencies between intellectual characteristics and gaming ability, measured with the aid of a computer game
Authors: Margolis A. A. , Kuravsky L. S. , Artemenkov S. L. , Voitov V. K. , Shepeleva E. A. , Gavrilova E. V. , Ermakov S. S.
Published: September 2020

The aim of this paper is testing a computer game as an alternative tool for the assessment of intelligence and creativity of school children. The relevance of the research task is determined by the growing interest in practical psychology in the use of computer games as a special diagnostic tool in educational process. There are two original factor models that have been developed and the structural equation modeling of measured parameters has been carried out. The relationships between game dynamic and final individual results in the computer game, on the one hand, and psychometric intelligence and divergent creativity, on the other, are presented. Weak correlation between the above-mentioned and individually measured intellectual and creativity characteristics of the participants with the computer game results was discovered. Consideration of these characteristics in the form of a common latent factor makes it possible to identify the corresponding dependencies only in some cases when there is a dividing the sample into groups according to their ability level. Particularly, the dynamics of game scoring allows to refer participants to the target group with a certain level of abilities (high intelligence and creativity versus low intelligence and creativity), and it is the high level of psychological traits that determines effectiveness in the game behavior, but not vice versa. The qualitative ratios of the two groups of subsets of participants were revealed: weak, medium and strong players and players with three different levels of psychological abilities. The prospects for the further use of computer games for assessment of cognitive abilities in the measurement of combination of psychological abilities are discussed.
A Semi-Analytic, Numerically Efficient Model for Low-Frequency Sound Scattering by an Infinite Cylinder Located Near a Boundary
Authors: Baynes Alexander B. , Godin Oleg A.
Published: September 2020

Scattering of sound by a target can be described as a wave radiated by virtual point sources inside the target. In the Rayleigh scattering regime, the strength of the virtual sources can be calculated analytically. When a target is located close to the ocean surface or another reflecting boundary, reflections of the incident and single-scattered waves from the boundary lead to multiple scattering from the target, with the target being insonified by nearby virtual sources. At low frequencies and for shallow targets, the distance from a virtual source to the target is not necessarily large compared to the acoustic wavelength or the target’s dimensions. Then, multiple orders of scattering make significant contributions and incident wave fields that cannot be approximated as a plane wave. This paper takes advantage of the virtual source concept and recently derived explicit analytic representations of 2D acoustic Green’s functions in unbounded fluids with inclusions of a circular cross-section, to develop a simple, intuitive, and numerically efficient model of multiple scattering. Scattering from soft, hard, and fluid targets is considered. The model is used to study the acoustic field in the vicinity of cylindrical targets near a pressure release surface or a hard bottom.
Do Religious Contexts Elicit More Trust and Altruism? Decision-Making Scenario Experiments
Authors: Ruffle Bradley J. , Sosis Richard
Published: September 2020

We design a decision-making scenario experiment on Facebook to measure subjects’ altruism and trust towards attendees of religious service, a fitness class and a local music performance. Secular and religious subjects alike display significantly more altruism and trust towards the synagogue attendees than attendees of the other two non-religious venues. We also find that secular subjects are just as altruistic towards synagogue and prayer group attendees as religious subjects are. These findings support recent theories that emphasize the pivotal role of religious context in arousing high levels of prosociality.