bluuebunny/crossref_metadata_2025 huggingface dataset:
High Dimensional Matching Optimization of Impeller–Vaned Diffuser Interaction for a Centrifugal Compressor Stage
Authors: Qin Ruihong , Ju Yaping , Galloway Lee , Spence Stephen , Zhang Chuhua
Published: July 2020

The matching and interaction between the impeller and vaned diffuser is the most important aerodynamic-coupling between the components of a high-speed centrifugal compressor. Many research studies have been carried out during the last decade, both experimentally and numerically, on the flow mechanisms underlying impeller–vaned diffuser matching and interaction, with the aim of achieving a high-performance stage. However, the published work lacks any study that optimizes the matching of the impeller–vaned diffuser components in the environment of a full compressor stage due to two unresolved issues, i.e., identifying an effective matching optimization strategy and the high dimensional nature of the problem. To tackle these difficulties, four different optimization strategies (i.e., (1) integrated, (2) single component, (3) parallel, and (4) sequential optimization strategies) have been proposed and validated through a high dimensional matching optimization of the Radiver compressor test case published by the Institute of Jet Propulsion and Turbomachinery at Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University. Particular attention has been paid to the slope of the diffuser total pressure ratio characteristic near the surge point to further extend the stage surge margin. The results showed that the integrated optimization strategy was the most effective one for achieving good matching of the impeller–vaned diffuser interaction due to its inherently strong coupling optimization. Compared with the baseline compressor, the optimized stage achieved a gain of 1.2% in total-to-total isentropic efficiency at the peak efficiency point as well as a predicted 26.17% increase in stable operating range. For the stage examined in this study, a fore-loaded design of impeller blade as well as an increased vane angle for the diffuser vane was beneficial to the impeller–vaned diffuser matching. The more uniform spanwise distributions of the impeller discharge flow angle and the diffuser vane incidence presented the opportunity for a more optimized matching of the flow field between the 3D impeller and the 2D vaned diffuser. The outcomes of this work are particularly relevant for the advanced design of high-speed centrifugal compressors.
Out in the Field Versus Inside in the Lab: A Comparison of Design Professionals’ Concept Screening Practices
Authors: Zheng Xuan , Miller Scarlett R.
Published: July 2020

Concept screening is one of the gatekeepers of innovation process and thus is considered a vital component of engineering design. Yet, we know very little about how decisions are made during concept screening or the factors that inform these decisions. This is due, in part, to the fact that most prior work on concept screening in engineering design has focused on student populations or on industry professionals in an experimental setting which is not indicative of the risks and consequences professionals face in their daily work—particularly when it comes to innovative design process. Thus, the current study was developed to identify how the environmental settings (i.e., experimental versus naturalistic) and the role of the professionals in the design process (i.e., idea generators versus executives) impacts the criteria used to screen design ideas. Two studies were conducted including a workshop study with 45 design professionals from two companies in an experimental setting and a participatory ethnographic study with seven design professionals from a small electromechanical company in a naturalistic setting. The results showed stark differences in the criteria used to screen ideas between naturalistic and experimental practices and between idea generators and company executives. In addition, the results showed differences in the factors considered during concept screening between naturalistic and experimental environments. These results are used to identify opportunities for tools and methods that encourage the consideration of creative ideas in the engineering design industry and encourage appropriate risk-taking in engineering design.
Effect of Electric Current Pulse Type on Springback, Microstructure, Texture, and Mechanical Properties During V-Bending of AA2024 Aluminum Alloy
Authors: Mohammadtabar Nafiseh , Bakhshi-Jooybari Mohammad , Gorji Hamid , Jamaati Roohollah , Szpunar Jerzy A.
Published: July 2020

The present work focused on the effect of the electric current pulse type on the springback, microstructure, texture, and mechanical properties during the V-bending process of AA2024 aluminum alloy. In order to investigate this effect, three different forming conditions including conventional V-bending and electrically assisted V-bending with square and sinusoidal pulses were considered. The results indicated that the amount of springback significantly decreased from 45.5 deg (for the sample formed via conventional V-bending) to 24 deg by applying the sinusoidal pulse. Microstructural observations revealed lower stored energy in the samples formed by electric current pulses which resulted in larger grain size compared with the samples formed without electric pulses. In addition, the result showed that the intensity of the 〈111〉||BLD (bend line direction) fiber texture reduced after applying electric current pulses, whereas it was very strong in the sample formed without electric pulses. It was suggested that the electric current pulses led to change the slip plane of the dislocations from {111} to {110} through cross slip. The applying electric current pulses decrease the ultimate tensile strength (UTS) from 471.1 MPa (for the conventional tensile test) to 448.0 and 426.7 MPa for the square and sinusoidal pulses, respectively. On the other hand, the electric pulses improved the formability of the AA2024 alloy owing to the activation of more slip systems, inhibition of dislocation pinning, the promotion of dislocation movement, and the acceleration of restoration mechanisms.
Progress Toward Modeling and Optimization of Sustainable Machining Processes
Authors: Jawahir I. S. , Schoop J. , Kaynak Y. , Balaji A. K. , Ghosh R. , Lu T.
Published: July 2020

The topic of sustainable machining has in recent times emerged as a significant and impactful area of research focus as it directly deals with environmental health and protection, economic growth and prosperity, and societal wellbeing with greater health and wellness. More specifically, sustainable machining at product, process, and system levels deals with reducing negative environmental impact, offering improved energy and resource efficiency, generating a minimum quantity of wastes, providing operational safety, and offering improved personal health. This paper summarizes recent efforts by the world research community in sustainable machining with a systematic approach for the analysis of machining processes that are broadly classified as sustainable, beginning with dry machining, and then near-dry (also known as minimum quantity lubrication (MQL)) and cryogenic machining processes. The paper also extends its analysis to a hybrid mode of sustainable machining that effectively combines cryogenic and MQL machining processes for improved productivity and machining performance. While a significant part of this paper presents experimental analysis, the progress being made in modeling and optimization has also been discussed in the paper. In particular, major challenges involved in model development for practical implementation, with a view to selecting optimum cutting conditions and cutting tool selection, are primarily discussed in the paper. The need for continued modeling efforts for achieving deployable optimized conditions for sustainable machining is highly recognized, and further research is required in numerous fronts integrating the various convergent disciplines such as materials, mechanics, computational sciences, economics, environmental sciences.
Oblique Wave Scattering by a Floating Bridge in the Presence of a Vertical Permeable Flexible Barrier
Authors: Gayathri R. , Kar P. , Behera H. , Sahoo T.
Published: July 2020

The interaction between oblique water waves and floating bridge in the presence of a vertical partial flexible permeable barrier is studied under the assumption of the linear water wave theory in finite water depth. The associated mathematical problem is handled for a solution using the least-squares approximation method. The reflection and transmission coefficients, free surface elevation, wave force acting on the bridge and barrier are computed to study the effects of various wave and structural parameters for three different edge conditions. The study reveals that wave reflection decreases with an increase in porosity, and a reverse pattern is found in the case of wave transmission. As the normalized spacing between the barrier and the floating bridge increases, the reflection coefficient follows a periodically oscillatory pattern. Furthermore, it is noticed that regardless of the barrier configurations, the wave reflection increases for an increase in the angle of incidence. It is also found that the surface-piercing barrier is more efficient than the bottom-standing barrier as a wave barrier. Moreover, the results indicate that by placing a porous flexible barrier at an appropriate position, the wave force on the bridge can be reduced significantly.
Methodology for the Assessment and Optimization of Connection Parameter Combinations for Modular Floating Structures
Authors: Zhang Yuming , Liu Haixiao
Published: July 2020

To obtain an optimum connection parameter combination for modular floating structures of multiple functions, an integrated methodology for the assessment and optimization is proposed in the present work, out of consideration for the balance between the functional performance and economic effect. To illustrate the whole process, two types of modular floating structures, i.e., a modular wave energy converter (WEC) and a modular mobile offshore base (MOB), are taken as the cases. For the two cases, connection configurations are first specified based on structural functions as well as environment conditions; then, quantified measurements are established and studied, based on which the following process of selection of optimization algorithms is done and the optimum solutions are obtained, making up a whole process of specification of the connection parameter combination for modular floating structures. The proposed methodology possesses the potential of offering guidance for the phase of preliminary design of connection structures of modular floating structures.
Efficient Passage-Spectral Method For Unsteady Flows Under Stall Conditions
Authors: Romera David , Corral Roque
Published: July 2020

This paper presents an efficient method of approximating unsteady flows using a block-wise discrete spatial Fourier series for the modeling of three-dimensional non-axisymmetric flows without making any hypothesis about its temporal periodicity. The method aims at capturing the long-wavelength flow patterns that are present in many unsteady problems of industrial interest, such as compressor stability, with a drastic reduction in computational resources. The method is intended to be used to compute flows exhibiting large-scale instabilities and where the fundamental frequency of the problem is not known beforehand. The approach discretizes the domain using a finite number of blocks or passages, where the flow variables at the supposedly periodic boundaries are continuously updated using the spatial Fourier coefficients of a uniformly spaced set of reduced-passage domains. The NASA rotor 67 under the effect of distorted inflow conditions has been used as verification case to demonstrate the effectiveness and viability of the method. The comparison between the passage-spectral method and the full-annulus solution shows that sound solutions can be obtained with a low number of harmonics. The new method has also been applied to investigate the rotating stall inception of the NASA rotor 67 for distorted inlet flows near stall operating conditions. The method is shown to accurately reproduce the full-annulus solution with a few spatial harmonics, capturing the characteristic features of the complex flow induced by the tip leakage vortex breakdown. The computational cost in this application has been reduced by a factor of between three and seven. This number heavily depends on the ratio between the number of retained harmonics to the number of blades.
Cortactin Interacts with Hepatitis C Virus Core and NS5A Proteins: Implications for Virion Assembly
Authors: Nguyen Lap P. , Nguyen Tram T. T. , Nguyen Huu C. , Pham Hang T. , Han Kang Min , Choi Dong Hwa , Park Eun-Mee , Kang Sang Min , Tark Dongseob , Lim Yun-Sook , Hwang Soon B.
Published: July 2020

Cortactin is a cytoskeletal protein that regulates cell migration in response to a number of extracellular stimuli. The functional involvement of cortactin in the virus life cycle is not yet fully understood. The most significant finding is that cortactin strongly interacted with both hepatitis C virus (HCV) core and NS5A. Cortactin is involved in HCV assembly by tethering core and NS5A on the lipid droplets (LDs) with no effect on LD biogenesis. It was noteworthy that HCV NS5A and core activated cortactin by phosphorylation at tyrosines 421 and 466 to regulate cell migration. Collectively, our study shows that cortactin is a novel host factor involved in viral production and HCV-associated pathogenesis.
Polyphosphate Functions
In Vivo
as an Iron Chelator and Fenton Reaction Inhibitor
Authors: Beaufay François , Quarles Ellen , Franz Allison , Katamanin Olivia , Wholey Wei-Yun , Jakob Ursula
Published: July 2020

How do organisms deal with free iron? On the one hand, iron is an essential metal that plays crucial structural and functional roles in many organisms. On the other hand, free iron is extremely toxic, particularly under aerobic conditions, where iron rapidly undergoes the Fenton reaction and produces highly reactive hydroxyl radicals. Our study now demonstrates that we have discovered one of the first physiologically relevant nonproteinaceous iron chelators and Fenton inhibitors. We found that polyphosphate, a highly conserved and ubiquitous inorganic polyanion, chelates iron and, through its multivalency, prevents the interaction of iron with peroxide and therefore the formation of hydroxyl radicals. We show that polyP provides a crucial iron reservoir for metalloproteins under nonstress conditions and effectively chelates free iron during iron stress. Importantly, polyP is present in all cells and organisms and hence is likely to take on this crucial function in both prokaryotic and eukaryotic cells.
FEDS: a Novel Fluorescence-Based High-Throughput Method for Measuring DNA Supercoiling
In Vivo
Authors: Duprey Alexandre , Groisman Eduardo A.
Published: July 2020

DNA represents the chemical support of genetic information in all forms of life. In addition to its linear sequence of nucleotides, it bears critical information in its structure. This information, called DNA supercoiling, is central to all fundamental DNA processes, such as transcription and replication, and defines cellular physiology. Unlike reading of a nucleotide sequence, DNA supercoiling determinations have been laborious. We have now developed a method for rapid measurement of DNA supercoiling and established its utility by identifying a novel regulator of DNA supercoiling in the bacterium
Salmonella enterica
as well as behaviors that could not have been discovered with current methods.
Guanylate Binding Proteins Restrict Leishmania donovani Growth in Nonphagocytic Cells Independent of Parasitophorous Vacuolar Targeting
Authors: Haldar Arun Kumar , Nigam Utsav , Yamamoto Masahiro , Coers Jörn , Goyal Neena
Published: July 2020

The obligate intracellular parasiteLeishmaniacauses the disease leishmaniasis, which is transmitted to mammalian hosts, including humans, via the sandfly vector. Following the bite-induced breach of the skin barrier,Leishmaniais known to live and replicate predominantly inside professional phagocytes. AlthoughLeishmaniais also able to infect nonphagocytic cells, nonphagocytic cells support limited parasitic replication for unknown reasons. In this study, we show that nonphagocytic cells possess an intrinsic property to restrictLeishmaniagrowth. Our study defines a novel role for a family of host defense proteins, the guanylate binding proteins (GBPs), in antileishmanial immunity. Mechanistically, our data indicate that GBPs facilitate the delivery ofLeishmaniainto antimicrobial autolysosomes, thereby enhancing parasite clearance in nonphagocytic cells. We propose that this GBP-dependent host defense program makes nonphagocytic cells an inhospitable host cell type forLeishmaniagrowth.
Lipoprotein
N
-Acylation in
Staphylococcus aureus
Is Catalyzed by a Two-Component Acyl Transferase System
Authors: Gardiner John H. , Komazin Gloria , Matsuo Miki , Cole Kaitlin , Götz Friedrich , Meredith Timothy C.
Published: July 2020

Although it has long been known that
S. aureus
forms triacylated Lpps, a lack of homologs to known
N
-acylation genes found in Gram-negative bacteria has until now precluded identification of the genes responsible for this Lpp modification. Here, we demonstrate N-terminal Lpp acylation and chemotype conversion to the tri-acylated state is directed by a unique acyl transferase system encoded by two noncontiguous staphylococci genes (
lnsAB
). Since triacylated Lpps stimulate TLR2 more weakly than their diacylated counterparts, Lpp
N
-acylation is an important TLR2 immunoevasion factor for determining tolerance or nontolerance in niches such as in the skin microbiota. The discovery of the LnsAB system expands the known diversity of Lpp biosynthesis pathways and acyl transfer biochemistry in bacteria, advances our understanding of Lpp structural heterogeneity, and helps differentiate commensal and noncommensal microbiota.
Plant and Soil Development Cooperatively Shaped the Composition of the
phoD
-Harboring Bacterial Community along the Primary Succession in the Hailuogou Glacier Chronosequence
Authors: Bai Yan , Xiang Quanju , Zhao Ke , Yu Xiumei , Chen Qiang , Ma Menggen , Jiang Hao , Zhang Xiaoping , Penttinen Petri , Gu Yunfu
Published: July 2020

Phosphorus was the key limiting nutrient for soil development during primary succession that occurred in alpine and high-latitude ecosystems with cold and humid climates. The interactions of functional microbiota involved in phosphorus cycling in the rhizosphere under different soil developmental stages along primary succession are still rarely examined. We selected the pioneer species
Populus purdomii
as a model plant to study the
phoD
-harboring bacterial communities in rhizosphere and bulk soils along a mountain glacier chronosequence. Our results showed that the bulk soils and rhizosphere host distinct
phoD
communities and diversity that differentially varied along the chronosequence, describing in detail the development and compositional turnover of the
phoD
community in the course of primary succession and determining the main environmental factors driving the development.
Systematic Analysis of REBASE Identifies Numerous Type I Restriction-Modification Systems with Duplicated, Distinct
hsdS
Specificity Genes That Can Switch System Specificity by Recombination
Authors: Atack John M. , Guo Chengying , Litfin Thomas , Yang Long , Blackall Patrick J. , Zhou Yaoqi , Jennings Michael P.
Published: July 2020

Many bacterial species contain DNA methyltransferases that have random on/off switching of expression. These systems, called phasevarions (phase-variable regulons), control the expression of multiple genes by global methylation changes. In every previously characterized phasevarion, genes involved in pathobiology, antibiotic resistance, and potential vaccine candidates are randomly varied in their expression, commensurate with methyltransferase switching. Our systematic study to determine the extent of phasevarions controlled by invertible Type I R-M systems will provide valuable information for understanding how bacteria regulate genes and is key to the study of physiology, virulence, and vaccine development; therefore, it is critical to identify and characterize phase-variable methyltransferases controlling phasevarions.
Host Genetic Factors Associated with Vaginal Microbiome Composition in Kenyan Women
Authors: Mehta Supriya D. , Nannini Drew R. , Otieno Fredrick , Green Stefan J. , Agingu Walter , Landay Alan , Zheng Yinan , Hou Lifang
Published: July 2020

Globally, bacterial vaginosis (BV) is a common condition in women. BV is associated with poorer reproductive health outcomes and HIV risk. Typically, BV represents a shift in the vaginal microbiome from one that is dominated by
Lactobacillus
to one that is diverse. Despite many women having similar exposures, the prevalence of BV and nonoptimal vaginal microbiome is increased for women of African descent, suggesting a possible role for host genetics. We conducted a genome-wide association study of important vaginal microbiome traits in Kenyan women. We identified novel genetic loci and biological pathways related to mucosal immunity, cell signaling, and infection that were associated with vaginal microbiome traits; we replicated previously reported loci associated with mucosal immune response. These results provide insight into potential host genetic influences on vaginal microbiome composition and can guide larger longitudinal studies, with genetic and functional comparison across microbiome sites within individuals and across populations.
Supplemental Material: Dune-scale cross-strata across the fluvial-deltaic backwater regime: Preservation potential of an autogenic stratigraphic signature
Authors: Wu Chenliang , al. et
Published: July 2020

Additional details on methods and results.
Online supplementation for teaching evidence-based medicine: feasibility of a randomised-controlled trial
Authors: McCall Marcy C , Fanshawe Thomas R , McCartney David , Young Damion , Nunan David , Heneghan Carl
Published: July 2020

Background and Objectives

As teaching technology advances, medical education is increasingly using digital mediums and exploring instructional models such as the flipped classroom and blended learning courses, where the in-class taught sessions are more groups on content delivered before class. Early evidence suggests lectures and foundational material can be equally provided online, but we have low-quality research to be convinced. We aim to test and develop an online evidence-based teaching resource that seeks to improve the availability and scalability of evidence-based medicine (EBM) learning tools. We evaluate the feasibility of a study design that could test for changes in academic performance in EBM skills using an online supplement.

Methods

Mixed-methods feasibility study of a randomised controlled trial (RCT) in an undergraduate medical student cohort.

Results

Of a small cohort (n=34), eight participants agreed to randomisation and completed the study. No study participant completed the EBM supplementary course in full. Students report time-management as a significant barrier in participation, and all aspects of the study and communications should be delivered with efficiency a key consideration.

Conclusion

Randomising students to an online EBM supplement within a medical school programme presents challenges of recruitment and student motivation, but the study design is potentially feasible.
Longitudinal association between near-misses/minor injuries and moderate/severe injuries in industrial settings by presence/absence of depressive symptoms in a nationally representative sample of workers in Japan
Authors: Yamauchi Takashi , Takahashi Kunihiko , Suka Machi , Sasaki Takeshi , Takahashi Masaya , Yoshikawa Toru , Okoshi Hiroto , Umezaki Shigeo , Yanagisawa Hiroyuki
Published: July 2020

Objectives

The association between near-misses/minor injuries and moderate/severe injuries has yet to be investigated longitudinally. This study aimed to examine the longitudinal association between near-misses/minor injuries and moderate/severe injuries by the presence/absence of depressive symptoms using 1-year follow-up data obtained from a nationally representative sample of workers in Japan.

Methods

Of the 18 231 eligible participants at time 1 (T1), 12 127 who responded to the 1-year follow-up survey at time 2 (T2) (response rate: 66.5%; 4370 females and 7757 males; mean age (SD), 45.3 (10.5) years) were included in the analysis. Multivariate logistic regression analyses were performed with the presence/absence of moderate/severe injuries at T2 as the dependent variable.

Results

In total, 36.4% of participants reported depressive symptoms at T1. During the follow-up period, 1.6% of participants reported moderate/severe injuries in industrial settings. After adjusting for relevant variables, participants who reported near-misses (OR=1.7 (95% CI, 1.3 to 2.4)) and minor injuries (OR=2.5 (95% CI, 1.3 to 4.7)) at T1 were more likely to have moderate/severe injuries at T2 compared to those who reported no near-misses/minor injuries. However, this association was stronger in participants who did not have depressive symptoms at T1 than in those who had depressive symptoms.

Conclusions

While the predictive value of near-misses/minor injuries for the occurrence of moderate/severe injuries by the presence/absence of depressive symptoms should be cautiously interpreted, our findings suggest that the development and utilisation of near-miss/minor injury reporting systems may help reduce the likelihood of moderate/severe injuries among workers, especially those without depressive symptoms.
Case of multiple myeloma with cutaneous involvement and aberrant CD3 expression
Authors: Schiavo Luca , Di Palma Stefano , Verganti Sara
Published: July 2020

A six‐year‐old golden retriever presented for a fast‐growing mass at the level of the left mandibular area. Cytological evaluation was consistent with an anaplastic round cell neoplasm. CT scan and abdominal ultrasound showed the presence of a large mass affecting the left mandibular salivary gland, several subcutaneous nodules and generalised intra‐abdominal lymphadenomegaly. The mandibular mass was surgically removed, and histopathology and immunohistochemistry were compatible with plasma cell tumour with aberrant CD3 expression. Complete staging led to the diagnosis of multiple myeloma with skin and salivary gland involvement. After receiving one dose of vincristine, the dog was started on melphalan/prednisolone protocol. After initial improvement, the dog showed signs of progressive disease and was euthanased 35 days after starting treatment due to severe clinical deterioration. Postmortem examination showed infiltration by neoplastic cells in several organs including the heart, the conjunctiva and some abdominal organs.
Stability analysis for cosmological models in f(T, B) gravity
Authors: Franco Geovanny A. Rave , Escamilla-Rivera Celia , Levi Said Jackson
Published: July 2020

In this paper we study cosmological solutions of the f(T, B) gravity using dynamical system analyses. For this purpose, we consider cosmological viable functions of f(T, B) that are capable of reproducing the dynamics of the Universe. We present three specific models of f(T, B) gravity which have a general form of their respective solutions by writing the equations of motion as an autonomous system. Finally, we study its hyperbolic critical points and general trajectories in the phase space of the resulting dynamical variables which turn out to be compatible with the current late-time observations.
The study of temperature regimes of a pipe wall under turbulent regime and supercritical pressures
Authors: Mammadova J. P. , Abdullaev A. P. , Rzayev R. M. , Kelbaliev R. F. , Mammadova S. H. , Musazade I. V.
Published: July 2020

The flow regimes of liquids encountered in engineering practice are mainly turbulent due to their structure, with which the features of such flows at supercritical pressure are considered in the work and some results are compared with similar ones obtained at low Reynolds numbers. Under these conditions, the physical properties of the fluid change sharply in the parietal layer and, depending on the values of the heat flux density and temperature, the area of sharp changes in physical properties can move along the flow cross section. Depending on the influence of these factors, the nature of the fluid flow can change, which affects the patterns of heat transfer and, accordingly, the nature of the distribution of wall temperature. In particular, conditions were identified for the appearance of a primary and secondary improved heat transfer regime. The possibility of the existence of an anomalous behavior of heat transfer during a turbulent flow of aromatic hydrocarbons was revealed, the nature of the distribution of the wall temperature along the length of the experimental tube is examined, and the influence of changes in the thermophysical properties of the substance on it is analyzed. The experimental data for water and toluene with a deteriorated heat transfer mode deviate from the calculated by [Formula: see text]25%.

As is known, the flow regime of fluids in engineering practice is mainly turbulent in structure. Therefore, it is very important to study the characteristics of such flows at supercritical pressure and compare some results with similar results obtained at low Reynolds numbers.
A dynamic time-temperature-dependent process for thermal oxidation of Sn leading to SnOx thin films: Impedance spectroscopy study
Authors: Barreira Enzo A. , Pedrini Luiz F. K. , Boratto Miguel H. , Scalvi Luis V. A.
Published: July 2020

Tin dioxide (SnO2) thin films are obtained from resistive evaporation of metallic Sn followed by thermal oxidation at different temperatures in the range 200–500[Formula: see text]C. Results show that, besides the thickness of the evaporated Sn thin film, the oxidation process of Sn into SnO2 is highly dependent on the annealing time and temperature, presenting tin monoxide (SnO), as an intermediate compound, result of partial oxidation of the metallic Sn at intermediary time and temperature. The optical and electrical properties of the Sn thin films are altered by the oxidation degree of Sn into SnO[Formula: see text]. These important characteristics are evaluated through UV-Vis, SEM, EDS, XRD and Impedance Spectroscopy. Increase in the optical bandgap energy as well as in the surface charge density, verified by electrical impedance, are observed on samples with higher annealing temperature and time, which indicate sequential oxidation process in these films.
Some aspects of the inertial spin model for flocks and related kinetic equations
Authors: Benedetto D. , Buttà P. , Caglioti E.
Published: July 2020

In this paper, we study the macroscopic behavior of the inertial spin (IS) model. This model has been recently proposed to describe the collective dynamics of flocks of birds, and its main feature is the presence of an auxiliary dynamical variable, a sort of internal spin, which conveys the interaction among the birds with the effect of better describing the turning of flocks. After discussing the geometrical and mechanical properties of the IS model, we show that, in the case of constant interaction among the birds, its mean-field limit is described by a nonlinear Fokker–Planck equation, whose equilibria are fully characterized. Finally, in the case of non-constant interactions, we derive the kinetic equation for the mean-field limit of the model in the absence of thermal noise, and explore its macroscopic behavior by analyzing the mono-kinetic solutions.
EFFECT OF OXIDATION TIME ON STRUCTURAL AND OPTICAL PROPERTIES OF ZNO FILMS PREPARED BY HYDROTHERMAL OXIDATION OF ELECTRODEPOSITED ZN COATING ON ITO SUBSTRATE
Authors: KHAN SHAKIL , IFTIKHAR MUHAMMAD , ALVI HAFIZ WASEEM AHMAD , RASHEED MUHAMMAD ASIM , KHAN ABDUL FAHEEM , WAHEED ABDUL , MEHMOOD MAZHAR , SHAH ATTAULLAH , MAHMOOD ARSHAD
Published: July 2020

In this work, hydrothermal oxidation of electrodeposited zinc coatings is used to produce zinc oxide (ZnO) films. In the first step, zinc (Zn) coating is electrodeposited on indium tin oxide (ITO) coated glass substrate. The Zn films are then immersed in deionized water at [Formula: see text]C. The exposure time of Zn coating in deionized water is varied from 1[Formula: see text]h to 24[Formula: see text]h in sequence. At the 24[Formula: see text]h exposure time, X-ray diffraction (XRD) patterns reveal that zinc film has been completely converted to ZnO. Scanning electron microscope (SEM) results show morphological changes from flakes (for pure Zn) or 2D plates to rod (ZnO) like morphology which further changes to cotton-flower like shapes with an increase in oxidation time. Diffuse reflectance spectral measurements show the band gap tuning with oxidation time (it decreases from 3.28[Formula: see text]eV to 3.19[Formula: see text]eV). Photoluminescence (PL) spectra have depicted phonon replicas with energy separation of [Formula: see text][Formula: see text]meV for the ZnO films obtained after 6 and 12[Formula: see text]h exposure time in deionized water at [Formula: see text]C temperature.
Positive solutions of superlinear indefinite prescribed mean curvature problems
Authors: Omari Pierpaolo , Sovrano Elisa
Published: July 2020

This paper analyzes the superlinear indefinite prescribed mean curvature problem [Formula: see text] where [Formula: see text] is a bounded domain in [Formula: see text] with a regular boundary [Formula: see text], [Formula: see text] satisfies [Formula: see text], as [Formula: see text], [Formula: see text] being an exponent with [Formula: see text] if [Formula: see text], [Formula: see text] represents a parameter, and [Formula: see text] is a sign-changing function. The main result establishes the existence of positive regular solutions when [Formula: see text] is sufficiently large, providing as well some information on the structure of the solution set. The existence of positive bounded variation solutions for [Formula: see text] small is further discussed assuming that [Formula: see text] satisfies [Formula: see text] as [Formula: see text], [Formula: see text] being such that [Formula: see text] if [Formula: see text]; thus, in dimension [Formula: see text], the function [Formula: see text] is not superlinear at [Formula: see text], although its potential [Formula: see text] is. Imposing such different degrees of homogeneity of [Formula: see text] at [Formula: see text] and at [Formula: see text] is dictated by the specific features of the mean curvature operator.
Inferring attributes with picture metadata embeddings
Authors: Pijani Bizhan Alipour , Imine Abdessamad , Rusinowitch Michaël
Published: July 2020

Users in online social networks are vulnerable to attribute inference attacks due to some published data. Thus, the picture owner's gender has a strong influence on individuals' emotional reactions to the photo. In this work, we present a graph-embedding approach for gender inference attacks based on pictures meta-data such as (i) alt-texts generated by Facebook to describe the content of images, and (ii) Emojis/Emoticons posted by friends, friends of friends or regular users as a reaction to the picture. Specifically, we apply a semi-supervised technique, node2vec, for learning a mapping of pictures meta-data to a low-dimensional vector space. Next, we study in this vector space the gender closeness of users who published similar photos and/or received similar reactions. We leverage this image sharing and reaction mode of Facebook users to derive an efficient and accurate technique for user gender inference. Experimental results show that privacy attack often succeeds even when other information than pictures published by their owners is either hidden or unavailable.
Enabling transparent hardware acceleration on Zynq SoC for scientific computing
Authors: Stornaiuolo Luca , Carloni Filippo , Pressiani Riccardo , Natale Giuseppe , Santambrogio Marco , Sciuto Donatella
Published: July 2020

In a quest for making FPGA technology more accessible to the software community, Xilinx recently released PYNQ, a framework for Zynq that relies on Python and
overlays
to ease the integration of functionalities of the programmable logic into applications. In this work we build upon this framework to enable transparent hardware acceleration for scientific computations for Zynq. We do so by providing a custom NumPy library designed for PYNQ, as it is the de-facto scientific library for Python. We then demonstrate the effectiveness of the proposed approach on a biomedical use case involving the extraction of features from the Electroencephalography (EEG).
Communication—Platinum and Tin Oxide Dispersed in a Fluffy TiO2 Nanolayer for Electrocatalytic Reduction of Oxygen
Authors: Jasim Ahmed. M. , Al-Salihi Sara , Xing Yangchuan
Published: July 2020

Pt catalysts perform well in the oxygen reduction reaction (ORR), but they suffer weak bonding with carbon supports, leading to catalyst degradation. We introduce a fluffy titanium dioxide (TiO2) nanolayer with a very high specific surface area as support, made possible with a new condensed layer deposition technique. When Pt and SnO2 were incorporated in it as co-catalyst, a remarkable improvement in ORR onset potential was achieved at 930 mV vs RHE in sulfuric acids. The mass activity was 2.66 times that of Pt/C at 900 mV. The fluffy layer stabilized SnO2 and together, they enabled a pronounced ligand effect.
The Development of Jelly Roll Deformation in 18650 Lithium-Ion Batteries at Low State of Charge
Authors: Willenberg Lisa , Dechent Philipp , Fuchs Georg , Teuber Moritz , Eckert Marcel , Graff Martin , Kürten Niklas , Sauer Dirk Uwe , Figgemeier Egbert
Published: July 2020

In this paper, the origin of the jelly roll deformation in 18650 lithium-ion batteries is examined in more detail by combining volume expansion measurements, accelerated lifetime testing, and CT imaging. Based on the presented research, a theory is developed to determine the cause of the jelly roll deformation at low states of charge (0%–20% SOC). The diameter of the cell is increasing during ageing, which reflects the increase of the internal pressure. Continuously growing cover layers of chemical degradation explain the latter. It is concluded that for releasing internal pressure, the jelly roll starts to deform. This deformation accelerates the ageing processes by electrically isolating active material from the current collector and the formation of fresh SEI. In addition, the CT images are used to determine the time of the deformation. Conclusively, it is shown that the jelly roll deformation is driven by cyclic ageing. Due to the correlation of the mean diameter change and the capacity curve, the deformation of the jelly roll and thus the sudden cell death can be predicted by measuring the mean diameter change of the battery.
Review—Recent Advances in Designing Gallium Oxide MOSFET for RF Application
Authors: Yadava Narendra , Chauhan R. K.
Published: July 2020

The large bandgap (∼4.8 eV), high critical field strength (∼8 MV cm−1) and high saturation velocity (∼2e7 cm s−1) are the key enabling material parameters of gallium oxide (GO) which allows it for designing high power radio frequency (RF) MOSFET. In MOS device-based applications, these material parameters combined with large area native substrates and ion-implantation technology results in exceptionally low ON-state power losses, high-speed power, RF switching, and more stable high-temperature operation. This paper comprehensively focuses on reviewing the latest progress of ultra-wide bandgap GO MOSFET for RF application. The performance of GO MOS devices is fully discussed and compared. Finally, potential solutions to the challenges of GO-based MOSFET for RF applications are also discussed and explored.
Evaluation of an Ag85B Immunosensor with Potential for Electrochemical Mycobacterium Tuberculosis Diagnostics
Authors: Murphy Brian , Dempsey Eithne
Published: July 2020

Tuberculosis remains a major global health concern, especially in the developing world, and monitoring/early detection of the disease relies on low cost technologies that provide rapid and accurate results. Mycobacterium tuberculosis is the responsible bacterial pathogen and it is currently estimated by the World Health Organisation (WHO), that one quarter of the world’s population, mainly in the developing world, is infected with TB. The overall aim of this work was to advance a screening electrochemical sensor for label free detection of Ag85B, a member of the Antigen 85 complex—major secretary protein of M. tuberculosis and biomarker for disease. An indirect ELISA Ag85B assay was optimised with capture antibody and antigen levels determined via a checkerboard titration (0.625 μg ml−1 and 2.5 μg ml−1 respectively). Following assay development, crosslinking of the bioreceptor Anti-Ag85B onto electrochemically deposited gold nanoparticle (AuNP) modified carbon electrodes was achieved and Ag85B binding successfully evaluated electrochemically via cyclic voltammetry. Following each modification step, ΔEp of a redox probe was monitored and overall results show that GCE/AuNP/anti-Ag85B electrochemical transducers are a viable method for Ag85B detection, capable of measuring antigen levels <2.5 μg ml−1.
CURRENT TOPICS FOR TEACHING SKELETAL MUSCLE PHYSIOLOGY
Authors: Brooks Susan V.
Published: July 2020

Contractions of skeletal muscles provide the stability and power for all body movements. Consequently, any impairment in skeletal muscle function results in some degree of instability or immobility. Factors that influence skeletal muscle structure and function are therefore of great interest both scientifically and clinically. Injury, disease, and old age are among the factors that commonly contribute to impairment in skeletal muscle function. The goal of this article is to update current concepts of skeletal muscle physiology. Particular emphasis is placed on mechanisms of injury, repair, and adaptation in skeletal muscle as well as mechanisms underlying the declining skeletal muscle structure and function associated with aging. For additional materials please refer to the “Skeletal Muscle Physiology” presentation located on the American Physiological Society Archive of Teaching Resources Web site ( https://www.lifescitrc.org ).
Inotropic and lusitropic, but not arrhythmogenic, effects of adipocytokine resistin on human atrial myocardium
Authors: Aitken-Buck Hamish M. , Babakr Aram A. , Fomison-Nurse Ingrid C. , van Hout Isabelle , Davis Philip J. , Bunton Richard W. , Williams Michael J. A. , Coffey Sean , Jones Peter P. , Lamberts Regis R.
Published: July 2020

The adipocytokine resistin is released from epicardial adipose tissue (EAT). Plasma resistin and EAT deposition are independently associated with atrial fibrillation. The EAT secretome enhances arrhythmia susceptibility and inotropy of human myocardium. Therefore, we aimed to determine the effect of resistin on the function of human myocardium and how resistin contributes to the proarrhythmic effect of EAT. EAT biopsies were obtained from 25 cardiac surgery patients. Resistin levels were measured by ELISA in 24-h EAT culture media ( n = 8). The secretome resistin concentrations increased over the culture period to a maximal level of 5.9 ± 1.2 ng/mL. Coculture with β-adrenergic agonists isoproterenol ( n = 4) and BRL37344 ( n = 13) had no effect on EAT resistin release. Addition of resistin (7, 12, 20 ng/mL) did not significantly increase the spontaneous contraction propensity of human atrial trabeculae ( n = 10) when given alone or in combination with isoproterenol. Resistin dose-dependently increased trabecula-developed force (maximal 2.9-fold increase, P < 0.0001), as well as the maximal rates of contraction (2.6-fold increase, P = 0.002) and relaxation (1.8-fold increase, P = 0.007). Additionally, the postrest potentiation capacity of human trabeculae was reduced at all resistin doses, suggesting that the inotropic effect induced by resistin might be due to altered sarcoplasmic reticulum Ca2+ handling. EAT resistin release is not modulated by common arrhythmia triggers. Furthermore, exogenous resistin does not promote arrhythmic behavior in human atrial trabeculae. Resistin does, however, induce an acute dose-dependent positive inotropic and lusitropic effect.
Endothelial prolyl hydroxylase 2 is necessary for angiotensin II-mediated renal fibrosis and injury
Authors: Zhao Yongzhen , Zeng Heng , Liu Bo , He Xiaochen , Chen Jian-Xiong
Published: July 2020

Angiotensin II (ANG II) is the key contributor to renal fibrosis and injury. The present study investigated the role of endothelium prolyl hydroxylase 2 (PHD2) in ANG II-mediated renal fibrosis and injury. In vitro, endothelial cells (ECs) were isolated from PHD2f/f control [wild-type (WT)] mice or PHD2 EC knockout (PHD2ECKO) mice. In vivo, WT and PHD2ECKO mice were infused with ANG II (1,000 ng·kg−1·min−1) for 28 days. Renal fibrosis, reactive oxygen species (ROS), and iron contents were measured. Knockout of PHD2 resulted in a significant increase in the expression of hypoxia-inducible factor (HIF)-1α and HIF-2α in ECs. Intriguingly, knockout of PHD2 significantly reduced expression of the ANG II type 1 receptor (AT1R) in ECs. WT mice infused with ANG II caused increases in renal fibrosis, ROS formation, and iron contents. ANG II treatment led to a downregulation of PHD1 expression and upregulation of HIF-1α and HIF-2α in the renal cortex and medulla. Knockout of PHD2 in EC blunted ANG II-induced downregulation of PHD1 expression. Furthermore, knockout of PHD2 in ECs attenuated ANG II-induced expression of HIF-1α, HIF-2α, transforming growth factor-β1, p47 phox, gp91 phox, heme oxygenase-1, and ferroportin. This was accompanied by a significant suppression of renal fibrosis, ROS formation, and iron accumulation. In summary, knockout of endothelial PHD2 suppressed the expression of AT1R in ECs and blunted ANG II-induced downregulation of PHD1 and upregulation of HIF-α in the kidney. Our study, for the first time, demonstrates a necessary role of endothelial PHD2 in ANG II-mediated renal fibrosis and injury.
Protective role of DJ-1 in endotoxin-induced acute kidney injury
Authors: Leeds Joseph , Scindia Yogesh , Loi Valentina , Wlazlo Ewa , Ghias Elizabeth , Cechova Sylvia , Portilla Didier , Ledesma Jonathan , Swaminathan Sundararaman
Published: July 2020

Acute kidney injury (AKI) is a frequent complication of sepsis and an important cause of morbidity and mortality worldwide. A cornerstone of sepsis-associated AKI is dysregulated inflammation, leading to increased tissue oxidative stress and free radical formation, which leads to multiple forms of cell death. DJ-1 is a peroxiredoxin protein with multiple functions, including its ability to control cellular oxidative stress. Although DJ-1 is expressed prominently by renal tubules, its role in AKI has not been investigated. In the present study, we examined the effect of DJ-1 deficiency in a murine model of endotoxin-induced AKI. Endotoxemia induced greater kidney injury in DJ-1-deficient mice. Furthermore, DJ-1 deficiency increased renal oxidative stress associated with increased renal tubular apoptosis and with expression of death domain-associated protein (DAXX). Similar to the in vivo model, in vitro experiments using a medullary collecting duct cell line (mIMCD3) and cytotoxic serum showed that serum obtained from wild-type mice resulted in increased expression of s100A8/s100A9, DAXX, and apoptosis in DJ-1-deficient mIMCD3 cells. Our findings demonstrate a novel renal protective role for renal tubular DJ-1 during endotoxemia through control of oxidative stress, renal inflammation, and DAXX-dependent apoptosis.