bluuebunny/crossref_metadata_2025_split huggingface dataset:
Euler–Lagrangian simulation of the fuel spray of a planar prefilming airblast atomizer
Authors: Hoffmann Sven , Holz Simon , Koch Rainer , Bauer Hans-Jörg 
Published: February 2021

AbstractThe pollutant emissions of aircraft engines are strongly affected by the fuel injection into the combustion chamber. Hence, the precise description of the fuel spray is required in order to predict these emissions more reliably. The characteristics of a spray is determined during the atomization process, especially during primary breakup in the vicinity of the atomizer nozzle. Currently, Euler-Lagrangian approaches are used to predict the droplet trajectories in combustor simulations along with reaction and pollutant formation models. To be able to reliably predict pollutant emissions in the future, well-defined starting conditions of the liquid fuel droplets close to the atomizer nozzle are necessary. In the present work, Euler-Lagrangian simulations of a generic airblast atomizer are presented. The starting conditions of the droplets are varied in the simulations by means of a primary breakup model, which takes into account the local gas velocity when predicting the droplet diameter. The objective of this work is to determine the optimal parameters of the probability density functions for the starting position and the starting velocity of the droplets. Spray properties observed in the simulations are used to qualitatively evaluate the major effects of the distribution parameters on the spray and the suitability of the primary breakup model being applied. Hence, the spatial distribution of an experimental spray can be reproduced using a statistical model for the droplet starting conditions.
Ancient wheat species are suitable to grain-only and grain plus herbage utilisations in marginal Mediterranean environments
Authors: Cadeddu Francesco , Motzo Rosella , Mureddu Francesca , Giunta Francesco 
Published: February 2021

AbstractThanks to their low fertilization requirements and high consumer demand, ancient wheats and old durum wheat cultivars represent an attractive option for the marginal areas of Mediterranean environments no longer cultivated due to the low grain yields attainable using modern wheat cultivars. Dual-purpose utilization may increase their value in these cropping systems, but no information is available on the suitability of ancient wheat species to this type of utilization. To fill this gap, Khorasan, einkorn, and emmer wheats, clipped at the terminal spikelet stage or left unclipped, were compared in a two-year field trial. The grains were sown in the month of October, in Sardinia (41°N, 80 m asl), Italy, on low-fertility soils and with low-medium fertilization rates. Einkorn cultivars produced the highest biomass yield (2–3 t ha−1), reflecting the longer time to the onset of the terminal spikelet stage (119–138 days). After clipping, all species recovered their ability to intercept radiation to the levels of the unclipped crops, but clipping lowered their radiation use-efficiency. Grain yield was not penalized by clipping: the increase in the harvest index compensated for the decrease in biomass. Here we show for the first time that ancient wheat species are suitable for dual-purpose utilization (herbage plus grain in the same season) rendering them valuable for marginal areas; this was because the early sowing adopted for dual-purpose utilization allowed them to take full advantage of their lateness in terms of herbage yield, and to bring flowering forward (i.e. make it earlier) so that a satisfactory grain yield was obtained, even under severe water stress. Dual-purpose utilization of ancient wheats increases the sustainability of mixed cropping systems, by making herbage available to animals in a critical period, without decreasing the grain yield attainable after grazing in the same season.
Thermal error modeling based on BiLSTM deep learning for CNC machine tool
Authors: Liu Pu-Ling , Du Zheng-Chun , Li Hui-Min , Deng Ming , Feng Xiao-Bing , Yang Jian-Guo 
Published: February 2021

AbstractThe machining accuracy of computer numerical control machine tools has always been a focus of the manufacturing industry. Among all errors, thermal error affects the machining accuracy considerably. Because of the significant impact of Industry 4.0 on machine tools, existing thermal error modeling methods have encountered unprecedented challenges in terms of model complexity and capability of dealing with a large number of time series data. A thermal error modeling method is proposed based on bidirectional long short-term memory (BiLSTM) deep learning, which has good learning ability and a strong capability to handle a large group of dynamic data. A four-layer model framework that includes BiLSTM, a feedforward neural network, and the max pooling is constructed. An elaborately designed algorithm is proposed for better and faster model training. The window length of the input sequence is selected based on the phase space reconstruction of the time series. The model prediction accuracy and model robustness were verified experimentally by three validation tests in which thermal errors predicted by the proposed model were compensated for real workpiece cutting. The average depth variation of the workpiece was reduced from approximately 50 µm to less than 2 µm after compensation. The reduction in maximum depth variation was more than 85%. The proposed model was proved to be feasible and effective for improving machining accuracy significantly.
Die ökonomische Situation von Familien zwischen März und Mai 2020, den ersten zwei Monaten der COVID 19-Pandemie
Authors: Boll Christina 
Published: February 2021

ZusammenfassungDer Artikel gibt einen Überblick über die wirtschaftliche Situation von Familien von Mitte März bis etwa Mitte Mai 2020, also den ersten zwei Monaten der COVID 19-Krise. Die Familieneinkommen sind wegen Arbeitslosigkeit und Kurzarbeit akut gefährdet. Auf der Einkommensseite greifen die Entschädigungen für Entgeltausfall durch Kita- und Schulschließungen im Rahmen des Infektionsschutzgesetzes nur partiell. Auch das gesetzliche Kurzarbeitergeld hilft nur bedingt, da Eltern unterschiedlich stark und manche gar nicht von ihm profitieren können, und die beschlossene Aufstockung kommt den Familien erst zeitverzögert zugute. Auch staatliche Familienleistungen wie der Notfall-Kinderzuschlag oder die jüngst beschlossene Elterngeldreform können die Einkommenseinbußen der Familien nur teilweise auffangen. Auf der Ausgabenseite drücken die Familien unveränderte Fixkosten. Zu den finanziellen Sorgen kommt in den Familien enorme Belastungen: Familien müssen Kinderbetreuung, Home Schooling, Haus- und Erwerbsarbeit allein schultern. Es zeichnet sich ab, dass Frauen weiterhin die Hauptlast der unbezahlten Arbeit tragen. Die jüngst vereinbarte Verlängerung der Entschädigungszahlungen nach dem Infektionsschutzgesetz wird den Familien helfen. Ein stufenweises Wiederhochfahren von Kitas, Schulen und Wirtschaft bleibt jedoch essenziell für die Rückkehr der Eltern in das Erwerbsleben und damit für die Sicherung der materiellen Existenzgrundlage von Millionen Familien.
Hydrothermally grown 1D ZnO nanostructures for rapid detection of NO2 gas
Authors: Godse P. R. , Mane A. T. , Navale Y. H. , Navale S. T. , Mulik R. N. , Patil V. B. 
Published: February 2021

AbstractThe present paper reports novel approach of surfactant and template free aqueous hydrothermal growth of 1D ZnO nanostructures, which facilitates the generation of large scale, low cost, and moderate working temperature films with controlled morphology for NO2 gas sensor application. Gas sensing properties of 1D ZnO nanostructures were studied at various temperatures for different reducing and oxidizing gases. As-fabricated by 1D ZnO nanostructures showed the highest sensor response of 11,791% with rapid response time of 9 s and recovery time of 220 s towards 100 ppm NO2. Moreover, for 5 ppm NO2 concentration, sensor showed a significant response of 70% with an response time of 16 s and recovery time of 200 s. The sensor shows good continuous performance in terms of response, response time, and recovery time, indicating that the sensor is highly reproducible and stable as well. This study successfully employed 1D ZnO nanostructures based NO2 sensing within the higher (100 ppm) and lower exposure limit (5 ppm) of NO2 gas.
The relationship between pubertal timing and under‐nutrition in rural Pakistan
Authors: Campisi Susan C. , Humayun Khadija N. , Wasan Yaqub , Soofi Sajid B. , Islam Muhammad , Hussain Amjad , Shakeel Agha , Vandermorris Ashley , Söder Olle , Bhutta Zulfiqar A. 
Published: February 2021

ABSTRACTIntroductionSexual development in females and males are routinely measured according to the Tanner Stages. Sparse data exist on the timing of pubertal milestones in Pakistan. To fill this gap, the age of attainment of pubertal milestones and their relationship with nutritional status was explored among children and adolescents living in the rural district of Matiari, Pakistan.MethodsAnthropometry, nutrition biomarkers and Tanner Stage were assessed among girls aged 9.0–14.9 years (n = 723) and boys aged 10.0–15.9 years (n = 662) who were free from known disease in the rural District of Matiari, Pakistan. Median age was calculated for all Tanner Stages and menarche. Multivariable linear regressions were undertaken to determine covariates associated with the timing (age) of pubertal milestones.ResultsAmong participants living in this rural community, the median age of puberty onset for girls was 11.9 years (95%CI:10.9; 12.5) and boys was 12.3 years (95%CI:11.5; 12.9). Age at first menarche was 12.9 years (95%CI:12.1; 13.3). Undernutrition was widespread among adolescents in this community. Thirty‐seven percent of females and 27.0% of males were stunted while 20.5% of females and 31.3% of males were thin. Only 8% (n = 58) of females and 12% (n = 78) of males were free from any nutrient deficiency with most adolescents having two or three nutrient deficiencies.ConclusionsUndernutrition (stunting or thinness) was associated with relatively older ages for early puberty stages but not puberty completion. This may decrease the duration of the pubertal growth spurt and curtail potential catch‐up growth that may occur during puberty. Efforts to decrease nutrient deficiencies, stunting and thinness beyond childhood should be made in rural Pakistan.
The Association of the COVID-19 Pandemic on Male Sexual Function in the United States: A Survey Study of Male Cannabis Users
Authors: Chen Tony , Bhambhvani Hriday P. , Kasman Alex M. , Eisenberg Michael L. 
Published: February 2021

Abstract

Introduction
International studies have suggested that social disruptions caused by the COVID-19 pandemic have led to sexual dysfunction, but the impact on males in the United States is less defined.

Aim
To examine changes in male sexual function during the COVID-19 pandemic and to evaluate associated demographic variables.

Methods
Prepandemic survey data was collected between October 20, 2019 and March 1, 2020 on adult males in the United States. Follow-up survey data collected for comparison during the COVID-19 pandemic between August 1, 2020 and October 10, 2020 included International Index of Erectile Function (IIEF) scores, Patient Health Questionnaire for Depression and Anxiety with 4 items (PHQ-4) scores, and questions regarding sexual frequency. Questions were also asked about mask-wearing habits, job loss, relationship changes, and proximity to individuals who tested positive for COVID-19.

Main Outcome Measures
Differences in prepandemic and pandemic male sexual function assessed by self-reported IIEF domain scores and sexual frequency

Results
Seventy six men completed both prepandemic and pandemic surveys with a mean age of 48.3 years. Overall, there were no differences in either overall IIEF score or any subdomain score when comparing men's pre-pandemic and pandemic survey data. There was an increase in sexual frequency during the pandemic with 45% of men reporting sex ten or more times per month during the pandemic compared to only 25% of men prior to the pandemic (P = .03). Among the subgroup of 36 men who reported a decrease in IIEF, the decrease was an average of 3.97, and significantly associated with higher PHQ-4 depression subscale scores (1.78 vs 1.03, P = .02).

Conclusion
The COVID-19 pandemic is associated with increased sexual frequency and no change in overall sexual function in males in the United States. Interventions intended to promote male sexual health during the COVID-19 pandemic should include a focus on mental health.
Oleic Acid and Eicosapentaenoic Acid Reverse Palmitic Acid-Induced Insulin Resistance in Human HepG2 Cells via the Reactive Oxygen Species/JUN Pathway
Authors: Sun Yaping , Wang Jifeng , Guo Xiaojing , Zhu Nali , Niu Lili , Ding Xiang , Xie Zhensheng , Chen Xiulan , Yang Fuquan 
Published: February 2021

Abstract
Oleic acid (OA), a monounsaturated fatty acid (MUFA), has previously been shown to reverse saturated fatty acid palmitic acid (PA)-induced hepatic insulin resistance (IR). However, its underlying molecular mechanism is unclear. In addition, previous studies have shown that eicosapentaenoic acid (EPA), a ω-3 polyunsaturated fatty acid (PUFA), reverses PA-induced muscle IR, but whether EPA plays the same role in hepatic IR and its possible mechanism involved need to be further clarified. Here, we confirmed that EPA reversed PA-induced IR in HepG2 cells and compared the proteomic changes in HepG2 cells after treatment with different free fatty acids (FFAs). A total of 234 proteins were determined to be differentially expressed after PA+OA treatment. Their functions were mainly related to responses to stress and endogenous stimuli, lipid metabolic process, and protein binding. For PA+EPA treatment, the PA-induced expression changes of 1326 proteins could be reversed by EPA, 415 of which were mitochondrial proteins, with most of the functional proteins involved in oxidative phosphorylation (OXPHOS) and tricarboxylic acid (TCA) cycle. Mechanistic studies revealed that the protein encoded by JUN and reactive oxygen species (ROS) play a role in OA- and EPA-reversed PA-induced IR, respectively. EPA and OA alleviated PA-induced abnormal adenosine triphosphate (ATP) production, ROS generation, and calcium (Ca2+) content. Importantly, H2O2-activated production of ROS increased the protein expression of JUN, further resulting in IR in HepG2 cells. Taken together, we demonstrate that ROS/JUN is a common response pathway employed by HepG2 cells toward FFA-regulated IR.
DEBKS: A Tool to Detect Differentially Expressed Circular RNAs
Authors: Liu Zelin , Ding Huiru , She Jianqi , Chen Chunhua , Zhang Weiguang , Yang Ence 
Published: February 2021

Abstract
Circular RNAs (circRNAs) are involved in various biological processes and disease pathogenesis. However, only a small number of functional circRNAs have been identified among hundreds of thousands of circRNA species, partly because most current methods are based on circular junction counts and overlook the fact that a circRNA is formed from the host gene by back-splicing (BS). To distinguish the expression difference originating from BS or the host gene, we present differentially expressed back-splicing (DEBKS), a software program to streamline the discovery of differential BS events between two rRNA-depleted RNA sequencing (RNA-seq) sample groups. By applying to real and simulated data and employing RT-qPCR for validation, we demonstrate that DEBKS is efficient and accurate in detecting circRNAs with differential BS events between paired and unpaired sample groups. DEBKS is available at https://github.com/yangence/DEBKS as open-source software.
How Credit Markets Substitute for Welfare States and Influence Social Policy Preferences: Evidence from US States
Authors: Wiedemann Andreas 
Published: February 2021

AbstractWhat is the relationship between debt and the welfare state? Recent arguments suggest that credit markets fill gaps left by limited social benefits but often rest on thin empirical grounds. This article makes two contributions to this debate by using micro-level panel data and leveraging variation in welfare state generosity across US states and over time. First, it shows that households that experience unemployment borrow significantly more in states where unemployment benefits are low compared to states where benefits are high. A 10-percentage-point decrease in unemployment replacement rates increases debt levels by about 30 per cent, or $5,300. Secondly, the article documents that rising indebtedness in the context of weak social policies has political consequences and increases support for a stronger safety net. One explanation is that voters seek social protection against downstream debt-induced economic risks. These findings suggest that welfare states can play a critical role in mitigating growing indebtedness.
Positionality, Power, and Positions of Power: Reflexivity in Elite Interviewing
Authors: Glas Aarie 
Published: February 2021

ABSTRACTThere is growing consensus in political science methods literature that positionality is consequential for interview research in variable and important ways. At the same time, however, much of this literature reinforces a categorical distinction between elite and non-elite contexts and participants, and it assumes “elite” to be a static category that presents researchers with discrete challenges that require uniform strategies to address. This article draws on my experience in conducting interviews with more than 100 “elites” to address this divide in two ways. First, I show that the category of elite is not as monolithic as often asserted. Rather, speaking with educated and authoritative individuals is fraught with variable challenges related to positionality. Second, to address these challenges, I argue that researchers must engage in active reflexivity, interrogating the relational effects of positionality across all aspects of research. I focus particular attention on issues of access and interactions within interviews.
Chameleonic Noise in GPS Position Time Series
Authors: Santamaría‐Gómez Alvaro , Ray Jim 
Published: February 2021

AbstractIt has been a standard practice for about 2 decades to compute global positioning system (GPS)‐based station velocity uncertainties using the apparent noise statistics of the non‐linear position residuals rather than assume white noise (WN) behavior. The latter choice would yield unrealistic velocity uncertainties. The most common noise types used are power‐law, usually close to flicker noise (FN), over most frequencies mixed with WN at the shortest periods. The complicating impact of offsets in the position time series, mostly caused by equipment changes or tectonic events, has not been fully appreciated. These are far less benign than recently suggested. In addition to contributing a pseudo‐random walk noise (RW) component to the velocity errors, estimating offset parameters changes the apparent noise color toward whiter. Spectral power is effectively drained by offsets at periods longer than roughly the mean span between them. This consequently favors a Gauss‐Markov process as the apparently preferred noise model and, importantly, obscures the presence of RW and long‐period Earth deformation in the series. Both effects can lead to potentially under‐estimated velocity uncertainties. The full value of decadal‐long GPS time series for geodynamical applications is thereby greatly eroded by recurring offsets, especially when they occur quasi‐regularly. In addition, contrary to common assumption, the noise color is generally not fixed with time, but clearly becomes whiter in more recent data. The origin of the colored noise and its whitening over time remain elusive.
Aerosols in Exoplanet Atmospheres
Authors: Gao Peter , Wakeford Hannah R. , Moran Sarah E. , Parmentier Vivien 
Published: February 2021

AbstractObservations of exoplanet atmospheres have shown that aerosols, like in the solar system, are common across a variety of temperatures and planet types. The formation and distribution of these aerosols are inextricably intertwined with the composition and thermal structure of the atmosphere. At the same time, these aerosols also interfere with our probes of atmospheric composition and thermal structure, and thus a better understanding of aerosols lead to a better understanding of exoplanet atmospheres as a whole. Here we review the current state of knowledge of exoplanet aerosols as determined from observations, modeling, and laboratory experiments. Measurements of the transmission spectra, dayside emission, and phase curves of transiting exoplanets, as well as the emission spectrum and light curves of directly imaged exoplanets and brown dwarfs have shown that aerosols are distributed inhomogeneously in exoplanet atmospheres, with aerosol distributions varying significantly with planet equilibrium temperature and gravity. Parameterized and microphysical models predict that these aerosols are likely composed of oxidized minerals like silicates for the hottest exoplanets, while at lower temperatures the dominant aerosols may be composed of alkali salts and sulfides. Particles originating from photochemical processes are also likely at low temperatures, though their formation process is highly complex, as revealed by laboratory work. In the years to come, new ground‐ and space‐based observatories will have the capability to assess the composition of exoplanet aerosols, while new modeling and laboratory efforts will improve upon our picture of aerosol formation and dynamics.
Topography Curvature Effects in Thin‐Layer Models for Gravity‐Driven Flows Without Bed Erosion
Authors: Peruzzetto Marc , Mangeney Anne , Bouchut François , Grandjean Gilles , Levy Clara , Thiery Yannick , Lucas Antoine 
Published: February 2021

AbstractDepth‐averaged thin‐layer models are commonly used to model rapid gravity‐driven flows such as debris flows or debris avalanches. However, the formal derivation of thin‐layer equations for general topographies is not straightforward. The curvature of the topography results in a force that maintains the velocity tangent to the topography. Another curvature term appears in the bottom friction force with frictional rheologies. In this work, we present the main lines of the mathematical derivation for these curvature terms that are proportional to the square velocity. With the SHALTOP numerical model, we quantify their influence on flow dynamics and deposits over synthetic and real topographies. This is done by comparing simulations in which these terms are exact, disregarded or approximated. With the Coulomb rheology, for slopes θ = 10 and for friction coefficients below μ = tan (5°), neglecting the curvature force increases the simulated travel times by up to 10% and 30%, for synthetic and real topographies respectively. When the curvature in the friction force is neglected, the travel distance may be increased by several hundred meters on real topographies, whatever the topography slopes and friction coefficients. We observe similar effects on a synthetic channel with slope θ = 25° and μ = 15°, with a 50% increase of the kinetic energy. Finally, approximations of curvature in the friction force can break the noninvariance of the equations and decelerate the flow. With the Voellmy rheology, these discrepancies are less significant. Curvature effects can thus have significant impact for model calibration and for overflows prediction, both being critical for hazard assessment.