bluuebunny/crossref_metadata_2025_split huggingface dataset:
The triple-deck stage of marginal separation
Authors: Braun Stefan , Scheichl Stefan , Kuzdas Dominik 
Published: June 2021

AbstractThe method of matched asymptotic expansions is applied to the investigation of transitional separation bubbles. The problem-specific Reynolds number is assumed to be large and acts as the primary perturbation parameter. Four subsequent stages can be identified as playing key roles in the characterization of the incipient laminar–turbulent transition process: due to the action of an adverse pressure gradient, a classical laminar boundary layer is forced to separate marginally (I). Taking into account viscous–inviscid interaction then enables the description of localized, predominantly steady, reverse flow regions (II). However, certain conditions (e.g. imposed perturbations) may lead to a finite-time breakdown of the underlying reduced set of equations. The ensuing consideration of even shorter spatio-temporal scales results in the flow being governed by another triple-deck interaction. This model is capable of both resolving the finite-time singularity and reproducing the spike formation (III) that, as known from experimental observations and direct numerical simulations, sets in prior to vortex shedding at the rear of the bubble. Usually, the triple-deck stage again terminates in the form of a finite-time blow-up. The study of this event gives rise to a noninteracting Euler–Prandtl stage (IV) associated with unsteady separation, where the vortex wind-up and shedding process takes place. The focus of the present paper lies on the triple-deck stage III and is twofold: firstly, a comprehensive numerical investigation based on a Chebyshev collocation method is presented. Secondly, a composite asymptotic model for the regularization of the ill-posed Cauchy problem is developed.
Optimal control of the Sabatier process in microchannel reactors
Authors: Blauth Sebastian , Leithäuser Christian , Pinnau René 
Published: June 2021

AbstractWe consider the optimization of a chemical microchannel reactor by means of PDE-constrained optimization techniques, using the example of the Sabatier reaction. To model the chemically reacting flow in the microchannels, we introduce a three- and a one-dimensional model. As these are given by strongly coupled and highly nonlinear systems of partial differential equations (PDEs), we present our software package cashocs which implements the adjoint approach and facilitates the numerical solution of the subsequent optimization problems. We solve a parameter identification problem numerically to determine necessary kinetic parameters for the models from experimental data given in the literature. The obtained results show excellent agreement to the measurements. Finally, we present two optimization problems for optimizing the reactor’s product yield. First, we use a tracking-type cost functional to maximize the reactant conversion, keep the flow rate of the reactor fixed, and use its wall temperature as optimization variable. Second, we consider the wall temperature and the inlet gas velocity as optimization variables, use an objective functional for maximizing the flow rate in the reactor, and ensure the quality of the product by means of a state constraint. The results obtained from solving these problems numerically show great potential for improving the design of the microreactor.
Thermophysics Analysis of Office Buildings with a Temperature–Humidity Coupling Strategy Under Hot-Arid Climatic Conditions
Authors: Bensafi Mohammed , Ameur Houari , Kaid Noureddine , Hoseinzadeh Siamak , Memon Saim , Garcia Davide Astiaso 
Published: June 2021

AbstractThis study investigates the determining parameters of thermal comfort of office in an arid hot-arid environment of Bechar, located in the northwestern region of Algeria, in which the vertical walls of the room and the roof are subjected to solar irradiations and the floor is considered to be adiabatic. The solar flux is calculated by the ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) method. The predicted results are validated against the experimental results of the meteorological station of the ENERGARID research laboratory at the University of Bechar (Algeria). The characteristics of the ambient air flow are performed by using the computational fluid dynamics (CFD) software (Fluent). The flow fields, thermal fields, and humidity are investigated. An elaborated computer program (with Delphi language) is utilized to evaluate the temperature–humidity coupling as the most essential factors of the thermal comfort. A significant impact of dynamic temperatures and humidity on thermal comfort has been observed, especially in this hot-arid environment. Besides, a considerable effect of the flow velocity has been remarked. From the obtained results and to provide the best thermal comfort in such arid regions, the range of air velocity inside the building is recommended to be between 0.2 m·s−1 and 0.3 m·s−1.
Optimal Space Trajectories with Multiple Coast Arcs Using Modified Equinoctial Elements
Authors: Pontani Mauro 
Published: June 2021

AbstractThe detection of optimal trajectories with multiple coast arcs represents a significant and challenging problem of practical relevance in space mission analysis. Two such types of optimal paths are analyzed in this study: (a) minimum-time low-thrust trajectories with eclipse intervals and (b) minimum-fuel finite-thrust paths. Modified equinoctial elements are used to describe the orbit dynamics. Problem (a) is formulated as a multiple-arc optimization problem, and additional, specific multipoint necessary conditions for optimality are derived. These yield the jump conditions for the costate variables at the transitions from light to shadow (and vice versa). A sequential solution methodology capable of enforcing all the multipoint conditions is proposed and successfully applied in an illustrative numerical example. Unlike several preceding researches, no regularization or averaging is required to make tractable and solve the problem. Moreover, this work revisits problem (b), formulated as a single-arc optimization problem, while emphasizing the substantial analytical differences between minimum-fuel paths and problem (a). This study also proves the existence and provides the derivation of the closed-form expressions for the costate variables (associated with equinoctial elements) along optimal coast arcs.
An early warning system for wave-driven coastal flooding at Imperial Beach, CA
Authors: Merrifield Mark A. , Johnson Mele , Guza R. T. , Fiedler Julia W. , Young Adam P. , Henderson Cassandra S. , Lange Athina M. Z. , O’Reilly William C. , Ludka Bonnie C. , Okihiro Michele , Gallien Timu , Pappas Kyle , Engeman Laura , Behrens James , Terrill Eric 
Published: June 2021

AbstractWaves overtop berms and seawalls along the shoreline of Imperial Beach (IB), CA when energetic winter swell and high tide coincide. These intermittent, few-hour long events flood low-lying areas and pose a growing inundation risk as sea levels rise. To support city flood response and management, an IB flood warning system was developed. Total water level (TWL) forecasts combine predictions of tides and sea-level anomalies with wave runup estimates based on incident wave forecasts and the nonlinear wave model SWASH. In contrast to widely used empirical runup formulas that rely on significant wave height and peak period, and use only a foreshore slope for bathymetry, the SWASH model incorporates spectral incident wave forcing and uses the cross-shore depth profile. TWL forecasts using a SWASH emulator demonstrate skill several days in advance. Observations set TWL thresholds for minor and moderate flooding. The specific wave and water level conditions that lead to flooding, and key contributors to TWL uncertainty, are identified. TWL forecast skill is reduced by errors in the incident wave forecast and the one-dimensional runup model, and lack of information of variable beach morphology (e.g., protective sand berms can erode during storms). Model errors are largest for the most extreme events. Without mitigation, projected sea-level rise will substantially increase the duration and severity of street flooding. Application of the warning system approach to other locations requires incident wave hindcasts and forecasts, numerical simulation of the runup associated with local storms and beach morphology, and model calibration with flood observations.
Do Colleges Perform the Same Following Developmental Education Reform? The Case of Florida’s Senate Bill 1720
Authors: Hu Xinye , Hu Shouping 
Published: June 2021

AbstractDevelopmental education (DE) reform took place among the 28 Florida College System (FCS) institutions in 2014. In this study, we examine how cohort-based passing rates in college-level English and math courses changed at different colleges for pre- and post-policy period and explore what institutional characteristics were related with various institutional trajectories of cohort-based course passing rates in the post-policy period. Employing longitudinal data analysis, we found that colleges performed similarly regarding cohort-based passing rates in both college-level English and combined math courses before DE reform and had a similar elevation in the cohort-based English course passing rates when DE reform took place in 2014. However, colleges experienced different change patterns in the years following DE reform. Specifically, colleges located in rural areas and with more White students experienced relatively lower college-level English passing rates in the post-policy period than their counterparts. Different colleges had slight differences in the trajectory of college-level math passing rates by cohort after SB 1720 in 2014, but institutional characteristics in this study did not adequately capture inter-institutional differences.
From Shared Enaction to Intrinsic Value. How Enactivism Contributes to Environmental Ethics
Authors: Werner Konrad , Kiełkowicz-Werner Magdalena 
Published: June 2021

AbstractTwo major philosophical movements have sought to fundamentally rethink the relationship between humans and their environment(s): environmental ethics and enactivism. Surprisingly, they virtually never refer to or seek inspiration from each other. The goal of this analysis is to bridge the gap. Our main purpose, then, is to address, from the enactivist angle, the conceptual backbone of environmental ethics, namely the concept of intrinsic value. We argue that intrinsic value does indeed exist, yet its "intrinsicality" does not boil down to being independent of the interests and needs of humans. Rather, it is brought forth by what we callshared enactionof an axiological domain. The latter is built upon such core posits of enactivism as autonomy, enaction, participatory sense-making as well as the most recent concept of loving as knowing proposed by Hanne De Jaegher.
Effects of thermal treatments on characteristics and morphological variations in the deposits of urea-SCR systems
Authors: Prabhu S Sadashiva , Natesan Kapilan , Nayak Nagaraj Shivappa 
Published: June 2021

AbstractSelective catalytic reduction (SCR) systems are employed by automobile manufacturers for the abatement of environmental pollutants like oxides of nitrogen (NOx) emitted from exhaust gases of diesel engines. In SCR, the urea-water solution (UWS) is injected to exhaust gases in the form of a spray to generate the reducing agent NH3. Deposit formation at lower temperatures is a major concern with this technology. The deposits not only create backpressure but also leak NH3 to the environment as they deplete. It is very important to know the depletion characteristics of deposits formed at lower temperatures in order to assess the NH3 leakage to the environment when the engine exhaust gases attain higher temperatures. In the present work, deposits formed at a low-temperature range of 150–200°C for continuous run along with UWS injection were investigated. Additionally, they were aged at 300°C in the absence of UWS to check the variation in characteristics with the rise of temperature. By gravimetric analysis, it is inferred that the deposits formed at higher pre-age temperatures are less prone to depletion as the temperature increases. The elemental analysis using energy-dispersive X-ray spectroscopy (EDX) indicates slight variation in carbon, nitrogen and oxygen compositions for all the pre-age conditions. As an extended study, the byproducts at pre-age and post-age conditions were investigated through X-ray diffraction (XRD). The compounds like cyanuric acid (CYA) and biuret were not observed when pre-age samples were aged at 300°C. Instead, the compounds like ammelide, ammeline, triuret and melamine were observed. Scanning electron microscope (SEM) study revealed morphological changes in both pre-age and post-age samples. Further, the crystallinity variations were also observed for the changes in the heating cycles during deposit formation. The gravimetric analysis of deposits in pre-age and post-age conditions helps in predicting the amount of deposits for transient load cycles.
Staphylococci and fecal bacteria as bioaerosol components in animal housing facilities in the Zoological Garden in Chorzów
Authors: Grzyb Jacek , Pawlak Krzysztof 
Published: June 2021

AbstractZoos are places open for a large number of visitors, adults and children, who can admire exotic as well as indigenous animal species. The premises for animals may contain pathogenic microbes, including those exhibiting antibiotic resistance. It poses a threat to people remaining within the zoo premises, both for animal keepers who meet animals on a daily basis and visitors who infrequently have contact with animals. There are almost no studies concerning the presence on the concentration of airborne bacteria, especially staphylococci and fecal bacteria in animal shelters in the zoo. There is no data about antibiotic resistance of staphylococci in these places. The results will enable to determine the scale of the threat that indicator bacteria from the bioaerosol pose to human health within zoo premises. This study conducted in rooms for 5 animals group (giraffes, camels, elephants, kangaroos, and Colobinae (species of monkey)) in the Silesian Zoological Garden in Chorzów (Poland). The bioaerosol samples were collected using a six-stage Andersen cascade impactor to assess the concentrations and size distribution of airborne bacteria. Staphylococci were isolated from bioaerosol and tested for antibiotic resistance. In our study, the highest contamination of staphylococci and fecal bacteria was recorded in rooms for camels and elephants, and the lowest in rooms for Colobinae. At least 2/3 of bacteria in bioaerosol constituted respirable fraction that migrates into the lower respiratory tract of the people. In investigated animal rooms, the greatest bacteria contribution was recorded for bioaerosol fraction sized 1.1–3.3μm. Bacterial concentrations were particularly strong in spring and autumn, what is related to shedding fur by animals. Among the isolated staphylococci which most often occurred were Staphylococcus succinus, S. sciuri, and S. vitulinus. The highest antibiotic resistance was noted in the case of Staphylococcus epidermidis, while the lowest for S. xylosus. In addition to standard cleaning of animal rooms, periodic disinfection should be considered. Cleaning should be carried out wet, which should reduce dust, and thus the concentrations of bacteria in the air of animal enclosures.
Geheimnisse in der Supervision von Psychotherapeut/innen in Ausbildung und Motive dafür
Authors: De Luca Anna-Lorena 
Published: June 2021

ZusammenfassungGeheimnisse sind omnipräsent: 97 % der Menschen haben mindestens ein Geheimnis, von dem niemand weiß. Die allgemeine Geheimnisforschung hat in den letzten Jahren zugenommen, fehlt aber noch im Supervisionsbereich. In einer anonymisierten Online-Befragung von Psychotherapeut/innen in Ausbildung (PiA) zeigte sich: Die häufigsten Geheimnisse in der Supervision sind, dass die Supervision keine Hilfe ist, die PiAs sich nicht ernst genommen fühlen und dass sich die Konzeptionen von PiAs von denen ihrer Supervisor/innen unterscheiden. Die häufigsten Motive für Geheimhaltung sind Scham, Bedenken um das eigene Ansehen und Selbstschutz. Supervisor/innen sollten vor allem offen, wertschätzend und vertrauensvoll sein, damit ihnen Geheimnisse anvertraut werden.
Wer kann, der coacht: Ein Instrument zur Messung interpersoneller Coach-Fähigkeiten
Authors: Müller Alessa Antonia , Möller Heidi 
Published: June 2021

ZusammenfassungEs wird ein aus der Psychotherapieforschung stammendes, an Coaching adaptiertes Ratingmanual zur Messung interpersoneller Fähigkeiten vorgestellt. Es wurden Ratings für 18 Audioaufnahmen von dyadischen Coachingsitzungen von neun Coaches-in-Weiterbildung erstellt, die zu Beginn der Weiterbildung und ein Jahr später durchgeführt wurden. Das interpersonelle Verhalten und die Entwicklung der Kompetenzen von zwei Coaches-in-Weiterbildung werden exemplarisch dargestellt. Die Autorinnen ziehen das Fazit, dass sich das Instrument dazu eignet, objektive, valide und reliable Bewertungen der interpersonellen Kompetenzen von Coaches zu erstellen. Es wird ein Ausblick auf die praktische Relevanz in Weiterbildung und Coachingpraxis und zukünftige Forschung gegeben.
Human Q Fever on the Guiana Shield and Brazil: Recent Findings and Remaining Questions
Authors: Epelboin Loïc , Eldin Carole , Thill Pauline , de Santi Vincent Pommier , Abboud Philippe , Walter Gaëlle , Melzani Alessia , Letertre-Gibert Paule , Perez Lucas , Demar Magalie , Boutrou Mathilde , Fernandes Jorlan , Cermeño Julman Rosiris , Panizo Maria Mercedes , Vreden Stephen GS , Djossou Félix , Beillard Emmanuel , de Waard Jacobus H. , de Lemos Elba Regina Sampaio 
Published: June 2021

Abstract
Purpose of Review
In this review, we report on the state of knowledge about human Q fever in Brazil and on the Guiana Shield, an Amazonian region located in northeastern South America. There is a contrast between French Guiana, where the incidence of this disease is the highest in the world, and other countries where this disease is practically non-existent.

Recent Findings
Recent findings are essentially in French Guiana where a unique strain MST17 has been identified; it is probably more virulent than those usually found with a particularly marked pulmonary tropism, a mysterious animal reservoir, a geographical distribution that raises questions.

Summary
Q fever is a bacterial zoonosis due to Coxiella burnetii that has been reported worldwide. On the Guiana Shield, a region mostly covered by Amazonian forest, which encompasses the Venezuelan State of Bolivar, Guyana, Suriname, French Guiana, and the Brazilian State of Amapá, the situation is very heterogeneous. While French Guiana is the region reporting the highest incidence of this disease in the world, with a single infecting clone (MST 117) and a unique epidemiological cycle, it has hardly ever been reported in other countries in the region. This absence of cases raises many questions and is probably due to massive under-diagnosis. Studies should estimate comprehensively the true burden of this disease in the region.
Time-Resolved Force Measurements to Determine Positioning Tolerances for Impulse-Based Indentations
Authors: Valentino Tobias , Höhmann Marian , Schünemann Kevin , Wentzler Jonas , Wünderlich Tim , Radel Tim , Vollertsen Frank 
Published: June 2021

AbstractHigh-throughput experimentation methods determine characteristic values, which are correlated with material properties by means of mathematical models. Here, an indentation method based on laser-induced shock waves is presented, which predicts the material properties, such as hardness and tensile strength, by the induced plastic deformation in the substrate material. The shock wave pushes a spherical indenter inside a substrate material. For reproducible indentations, the applied load is of importance. To compare different processes and process parameters, the measured plastic deformation is normalized by the applied load. However, eccentric irradiation leads to altered beam profiles on the surface of spherical indenters and the angle of incidence is changed. Thus, the influence of eccentric irradiation is studied with an adapted time-resolved force measurement setup to determine the required positioning tolerances. The spherical indenter is placed inside a cylindrical pressure cell to increase the laser-induced shock pressure. From the validated time-resolved force measurement method we derive that deviations from the indentation forces are acceptable, when the lateral deviation of the beam center, which depends only on the alignment of the setup, does not exceed ± 0.4 mm. A vertical displacement from the focus position between -3.0 mm and + 2.0 mm still leads to acceptable deviations from the indentation force.
Discrete element model for general polyhedra
Authors: Neto Alfredo Gay , Wriggers Peter 
Published: June 2021

AbstractWe present a version of the Discrete Element Method considering the particles as rigid polyhedra. The Principle of Virtual Work is employed as basis for a multibody dynamics model. Each particle surface is split into sub-regions, which are tracked for contact with other sub-regions of neighboring particles. Contact interactions are modeled pointwise, considering vertex-face, edge-edge, vertex-edge and vertex-vertex interactions. General polyhedra with triangular faces are considered as particles, permitting multiple pointwise interactions which are automatically detected along the model evolution. We propose a combined interface law composed of a penalty and a barrier approach, to fulfill the contact constraints. Numerical examples demonstrate that the model can handle normal and frictional contact effects in a robust manner. These include simulations of convex and non-convex particles, showing the potential of applicability to materials with complex shaped particles such as sand and railway ballast.
Why and how should we promote home dialysis for patients with end-stage kidney disease during and after the coronavirus 2019 disease pandemic? A French perspective
Authors: Rostoker Guy , Issad Belkacem , Fessi Hafedh , Massy Ziad A. 
Published: June 2021

AbstractThe health crisis induced by the pandemic of coronavirus 2019 disease (COVID-19) has had a major impact on dialysis patients in France. The incidence of infection with acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the first wave of the COVID-19 epidemic was 3.3% among dialysis patients—13 times higher than in the general population. The corresponding mortality rate was high, reaching 21%. As of 19th April, 2021, the cumulative prevalence of SARS-CoV-2 infection in French dialysis patients was 14%. Convergent scientific data from France, Italy, the United Kingdom and Canada show that home dialysis reduces the risk of SARS-CoV-2 infection by a factor of at least two. Unfortunately, home dialysis in France is not sufficiently developed: the proportion of dialysis patients being treated at home is only 7%. The obstacles to the provision of home care for patients with end-stage kidney disease in France include (i) an unfavourable pricing policy for home haemodialysis and nurse visits for assisted peritoneal dialysis (PD), (ii) insufficient training in home dialysis for nephrologists, (iii) the small number of administrative authorizations for home dialysis programs, and (iv) a lack of structured, objective information on renal replacement therapies for patients with advanced chronic kidney disease (CKD). We propose a number of pragmatic initiatives that could be simultaneously enacted to improve the situation in three areas: (i) the provision of objective information on renal replacement therapies for patients with advanced CKD, (ii) wider authorization of home dialysis networks and (iii) price increases in favour of home dialysis procedures.