bluuebunny/crossref_metadata_2025_split huggingface dataset:
NanoBRET binding assay for histamine H2 receptor ligands using live recombinant HEK293T cells
Authors: Grätz Lukas , Tropmann Katharina , Bresinsky Merlin , Müller Christoph , Bernhardt Günther , Pockes Steffen 
Published: August 2020

AbstractFluorescence/luminescence-based techniques play an increasingly important role in the development of test systems for the characterization of future drug candidates, especially in terms of receptor binding in the field of G protein-coupled receptors (GPCRs). In this article, we present the establishment of a homogeneous live cell-based BRET binding assay for the histamine H2 receptor with different fluorescently labeled squaramide-type compounds synthesized in the course of this study. Py-1-labeled ligand 8 (UR-KAT478) was found to be most suitable in BRET saturation binding experiments with respect to receptor affinity (pKd = 7.35) and signal intensity. Real-time kinetic experiments showed a full association of 8 within approximately 30 min and a slow dissociation of the ligand from the receptor. Investigation of reference compounds in BRET-based competition binding with 8 yielded pKi values in agreement with radioligand binding data. This study shows that the BRET binding assay is a versatile test system for the characterization of putative new ligands at the histamine H2 receptor and represents a valuable fluorescence-based alternative to canonical binding assays.
Connection between galactic downsizing and the most fundamental galactic scaling relations
Authors: Spitoni E. , Calura F. , Mignoli M. , Gilli R. , Silva Aguirre V. , Gallazzi A. 
Published: August 2020

Context. In their evolution, star-forming galaxies are known to follow scaling relations between some fundamental physical quantities, such as the relation between mass metallicity and star formation main sequence.
Aims. We study the evolution of galaxies that at a given redshift, lie simultaneously on the mass-metallicity and main-sequence relations (MZR, MSR).
Methods. To this aim, we used the analytical leaky-box chemical evolution model, in which galaxy evolution is described by the infall timescale τ and the wind efficiency λ. We provide a detailed analysis of the temporal evolution of their metallicity, stellar mass, mass-weighted age, and gas fraction.
Results. The evolution of the galaxies lying on the MZR and MSR at z ∼ 0.1 suggests that the average infall timescale in two different bins of stellar masses (M⋆ <  1010 M⊙ and M⋆ >  1010 M⊙) decreases with decreasing redshift through the addition of new galaxies with shorter timescales. This means that at each redshift, only the youngest galaxies can be assembled on the shortest timescales and still belong to the star-forming MSR. In the lowest mass bin, a decrease in median τ is accompanied by an increase in the median λ value. This implies that systems that formed at more recent times will need to eject a larger amount of mass to retain their low metallicity values. Another important result is that galactic downsizing, as traced by the age-mass relation, is naturally recovered by imposing the local MZR and MSR for star-forming galaxies. This result is retained even when a constant star formation efficiency for different galactic masses is assumed (without imposing the observed scaling relation between stellar mass and gas-depletion time-scales). Finally, we study the evolution of the hosts of C IV-selected active galactic nuclei, which at z ∼ 2 follow a flat MZR. When we impose that these systems lie on the MSR, we find an “inverted” MZR at lower redshifts, meaning that some additional processes must be at play in their evolution.
Conclusions. In our model, galactic downsizing is a direct consequence of the MZR and MSR for star-forming galaxies. This poses a challenge for models of galaxy evolution within a cosmological framework.
Dozens of virtual impactor orbits eliminated by the EURONEAR VIMP DECam data mining project
Authors: Vaduvescu O. , Curelaru L. , Popescu M. , Danila B. , Ciobanu D. 
Published: August 2020

Context. Massive data mining of image archives observed with large etendue facilities represents a great opportunity for orbital amelioration of poorly known virtual impactor asteroids (VIs). There are more than 1000 VIs known today; most of them have very short observed arcs and many are considered lost as they became extremely faint soon after discovery.
Aims. We aim to improve the orbits of VIs and eliminate their status by data mining the existing image archives.
Methods. Within the European Near Earth Asteroids Research (EURONEAR) project, we developed the Virtual Impactor search using Mega-Precovery (VIMP) software, which is endowed with a very effective (fast and accurate) algorithm to predict apparitions of candidate pairs for subsequent guided human search. Considering a simple geometric model, the VIMP algorithm searches for any possible intersection in space and time between the positional uncertainty of any VI and the bounding sky projection of any image archive.
Results. We applied VIMP to mine the data of 451,914 Blanco/DECam images observed between 12 September 2012 and 11 July 2019, identifying 212 VIs that possibly fall into 1286 candidate images leading to either precovery or recovery events. Following a careful search of candidate images, we recovered and measured 54 VIs in 183 DECam images. About 4,000 impact orbits were eliminated from both lists, 27 VIs were removed from at least one list, while 14 objects were eliminated from both lists. The faintest detections were around V ∼ 24.0, while the majority fall between 21 <  V <  23. The minimal orbital intersection distances remains constant for 67% detections, increasing for eight objects and decreasing for ten objects. Most eliminated VIs (70%) had short initial arcs of less than five days. Some unexpected photometric discovery has emerged regarding the rotation period of 2018 DB, based on the close inspection of longer trailed VIs and the measurement of their fluxes along the trails.
Conclusions. Large etendue imaging archives represent great assets to search for serendipitous encounters of faint asteroids and VIs.
Active metamaterial polarization modulators for the Terahertz frequency range
Authors: Kindness Stephen J. , Almond Nikita W. , Michailow Wladislaw , Wei Binbin , Braeuninger-Weimer Philipp , Hofmann Stephan , Beere Harvey E. , Ritchie David A. , Degl’Innocenti Riccardo 
Published: August 2020

Abstract
Active control of chirality in the terahertz frequency range is of great importance in many scientific areas, which include research into fundamental optical phenomena, investigation of novel materials, spectroscopy, imaging, wireless communications and chemistry. The lack of efficient, integrated and fast-reconfigurable polarization modulators has hindered, so far, the full exploitation of applications in all the aforementioned fields. Metamaterials are artificial resonant elements possessing unique remarkable properties such as high efficiency and miniaturization capability. The interplay of metallic metamaterial arrays with electrostatically tunable monolayer graphene has been demonstrated to be a valid approach for the realization of a novel class of THz devices. In this work, the realization of active chiral graphene/metamaterial modulator is presented. The versatility of this experimental approach allowed the device integration with broadband sources such as terahertz time domain spectrometers as well as with quantum cascade lasers. A continuous rotation of the polarization plane > 30° has been reported with a reconfiguration speed > 5 MHz. These results pave the way to the integration of fast terahertz polarization modulators in all the applications where these devices are in great demand.
Layer-by-layer assembled-composite nanocoating for functionalization of microstructured optical fibers
Authors: Ermatov T , Skibina J S , Noskov R E , Gorin D A 
Published: August 2020

Abstract
Hollow-core microstructured optical fibers (MOFs) possess the great potential for the integration of different materials inside the holey-capillaries leading to the creation of tailored hybrid structures. Moreover, the further improvement of MOF-based sensor performance can be achieved by exploiting the wide range of post-processing techniques directing to both the enhancement of the existing characteristics and the enabling of new functionalities. Here, we concentrate on hybrid MOFs whose hollow-capillaries were coated through the layer-by-layer assembly technique by a combination of oppositely charged polyelectrolytes and magnetite nanoparticles. We characterize the optical transmission and the fiber loss of the modified samples and show the scanning electron microscopy images illustrating the formed coatings on the inner fiber surfaces.
Determination of the gelification kinetics of a correction gel of injection profiles by ultraviolet-visible spectroscopy
Authors: Sánchez E , Villamizar J , Mantilla G , Rodriguez J , Roa M 
Published: August 2020

Abstract
Mature wells in which, for a long time, water injection has been used, as a method of recovery they reach a point where the water cut increases or remains constant. thus decreasing the recovered hydrocarbon factor; This phenomenon occurs because the water injected, has preferential recordings in the porous medium, and does not reach the hydrocarbon available in other areas of the formation, in this type of deposits the injection of polyacrylamide gels, crosslinked with acetate of chromium, these gels make a plugging, in areas of high water permeability, causing the change of path of the same, as well as move the hydrocarbon in other areas of the porous medium. At present, the kinetics of gelation of this type of substances is monitored qualitatively by means of the “Syddansk” code, which analyzes its consistency and elasticity, only by observation. Although this method is practical, it is not very descriptive and depends a lot on the opinion and criteria of the observer, being little reproducible. Given this situation, and the increase in chemical recovery projects in the country, a methodology is described that describes the moment of gelation, reproducibly and without the injection of the analyst. During the gelation process, different polyacrylamide-chromium gels were monitored in relationships used in field operations, using ultraviolet-visible spectroscopy, detecting a change in absorbances, of the spectra, which were analyzed to plant a kinetic model of gelation, in addition to generating the approach of a method, to identify the state of gelation based on the variation in absorbance.
Effect of solvent polarity during electrodeposition of asphaltenes from a Colombian oil in the presence of a magnetic field and magnetic nanoparticles
Authors: Roa M , Amaya I , Correa R 
Published: August 2020

Abstract
This work focuses on analyzing the electrokinetic behavior of asphaltenes of extra heavy oil. For this, electrodepositions were carried out in asphaltene solutions (4 %w/w) with two solvents of different polarities: toluene and chloroform. In addition, we worked with different magnetic fields, and the effect of adding 1% w/w of magnetic nanoparticles was analyzed. The asphaltenes were extracted with heptane and were characterized by infrared and ultraviolet visible spectroscopy. In the case of toluene, the initial adsorption (without fields) was 4 mg in both anode and cathode. By using an electric field (100 V/m) the deposits increased to 6 mg (anode) and 5 mg (cathode). However, when using a static magnetic field of 0.1 mT, no changes were observed. But, by modifying said field by a dynamic one (0.1 mT and 60 Hz), 15 mg (anode) and 19 mg (cathode) were obtained. Moreover, the addition of nanoparticles (previously characterized by scanning electron microscopy and X ray diffraction) changed the behavior, worsening in the absence of fields, and improving only in the presence of the dynamic field (104 mg, 26 mg in anode and cathode, respectively). Similar results were obtained when using chloroform. Thus, the best performance was obtained by using a dynamic magnetic field. By not considering the nanoparticles, total deposits increased more than 14 times (102 mg versus 7 mg). However, considering them, the increase was greater than 30 times (302 mg versus 10 mg). Therefore, we consider that adding nanoparticles, and supporting the electrodeposition process with a dynamic magnetic field, is an alternative that must be included to improve process performance.
Dynamic and sequential update for time series forecasting
Authors: Gallardo Pérez H J , Vergel Ortega M , Rojas-Suárez J P 
Published: August 2020

Abstract
Two different sciences, physics and statistics, have worked, from the foundations of each, on the explanation and modelling of stochastic processes characterized by the succession of random variables whose realizations at each instant of time give rise to time series. From Physics we have worked with the Fourier transform to explain the dynamics of time series, a similar case occurs from statistics where dynamic models of time series are worked to explain the variations of the series and, in both cases, to make reliable forecasts. The main objective of this research is to adjust a model, using the methodology framed in the sequential update procedure of the forecast, to a time series of coal production observed quarterly during the years 2007 to 2011, in order to disaggregate quarterly the annual production for the years 2012 to 2018. Once the process has been carried out and validated, a quarterly production model is estimated which allows valid and reliable forecasts to be made for each quarter in subsequent years.
Application of data mining as a tool in computer science
Authors: Velásquez-Pérez T , Camargo-Pérez J A , Quintero-Quintero E L 
Published: August 2020

Abstract
Computational science involves a systemic approach for adequate management of both information and knowledge; through theories of information and computation. Today trends such as big data and data mining emerge, with which behavior patterns previously only visible to the human eye can be established. This article, part of the analysis of big data, based on research found on the science websites, whose objective was based on knowing the conceptual evolution of Big data as well as the search for statistically regular behaviors over time in different elements related to the production and consumption of scientific information. For this study, data mining will be specified for Big data analysis, resulting in instructions to identify and understand trends and patterns within the different research areas.
Measuring the quality of the blended learning approach to teaching computational sciences
Authors: Perez B , Castellanos C , Correal D 
Published: August 2020

Abstract
Teaching models are a very interesting area of study that can be applied to any science. Finding the best way to transfer knowledge to students, so that they internalize it and can successfully transfer it to the field, is key to the country building. This article measures the quality of a teaching model that can be applied in physics or engineering, which requires a correct theoretical foundation before addressing practical elements. Blended learning is an approach to education that combines online educational materials and opportunities for interaction online with traditional place-based classroom methods. This model was applied in agile software architectures course and measured through an anonymous survey of students in software architecture, who were enrolled for the periods 2015-2018. The results showed that 39.7% of the respondents considered that they learned better compared to face-to-face courses.
Failure study as a physical component in mechanical suspensions of two automobile models of an automotive company
Authors: Serrano-Rincón C A , Navarro Torrado L , Florez-Solano E 
Published: August 2020

Abstract
Car suspensions are a key element for the good behavior of cars. There are many types with their advantages and disadvantages, but among them, the most used and known today is the MacPherson strut suspension. The MacPherson strut is a system devised by Earle S. MacPherson in the 40s and patented by Ford in 1953, which today is used for the front axle of most cars. This type of suspension is very versatile because it can be used on the rear as well as front axles, and because of its low cost. These types of vehicles present many breakdowns on these pieces in the municipality of “Ocaña, Norte de Santander, Colombia” since the type of terrain is very complex (steep slopes, poor condition of the roads, among others), which leads to breakdowns on the pieces due to shear stresses, which could cause a traffic accident and high repair costs. This work seeks to show the identification of the vehicles that use the MacPherson strut and its possible failures. Subsequently, the analysis of the stresses on the lower arm system of the MacPherson strut is carried out in compact cars using simulation software. to perform the physical analysis behavior.
Numerical Calculation of the Radiated Noise of Contrarotating Propellers
Authors: He Xiaohui , Liu Zhongle , Wang Xianyong , Yuan Zhiyong 
Published: August 2020

Abstract
Based on the hybrid methods of cavitation transient simulation of multiphase flow and the boundary element numerical acoustic calculation, the noise of contrarotating propellers in states of cavitation and non-cavitation is calculated, the increase quantity of the noise spectrum level in cavitation relative to in non-cavitation condition is analyzed; the calculated noise value and the tested value are compared. The multiphase flow transient simulation includes three simulations: unsteady Reynolds-averaged Navier-Stokes method (URANS), scale adaptive simulation (SAS) and detached eddy simulation (DES). The testing result shows that the open water performance curve of propellers coincides well with the experimental result in the range of large range of feed coefficient. SAS presents a comparable ability with DES in capturing the pulsating pressure of cavitation and can respond well to the unsteady load noise. RANS (Reynolds-averaged Navier-Stokes) is appropriate for the low frequency noise. The calculating error of line spectrum cavitation volume pulsation 1 kHz is less than4.23 dB, and the average error of spectrum level 1/3 Octave band is less than1.83dB in the frequency band of 1 kHz-3kHz, and the predicted error of the total sound pressure level is less than 2.74dB, And the attenuation coefficient of sound pressure level with is calculated by simulation, which can provide certain help for the design and the noise prediction of propellers.
Research on Solving Ionization Equation of High-Speed Aircraft Based on Euler Monte Carlo Method of Fluid Mechanics
Authors: Lu Ming 
Published: August 2020

Abstract
Taking the aerodynamic calculation of high-speed aircraft as an example, this paper introduces the modelling and application of computational fluid dynamics in aircraft design. The application of computational fluid dynamics in the design of aircraft is accompanied by the development of computer technology and aerodynamics. From the earlier solution of the Euler equation and the NS equation from a macro perspective, to the solution of the NS equation with chemical reactions and ionization that considers the influence of real gases, and from the micro perspective, the Monte Carlo method is used to directly simulate and solve the gas molecule motion, that is, It represents the development of computational dynamics theory and is also the result of the development of computer technology today. This article discusses the application of computational fluid mechanics, including the selection of mathematical models, the selection of calculation methods, and its application to special problems in aircraft design.
Effect of Surface Texture Distribution Parameters on Hydrodynamic Lubrication and Numerical Optimization
Authors: Huang Fengyun , Yang Xiaobing , Zhu Jiwei , Xu Jinli 
Published: August 2020

Abstract
Surface texture technology has been proven to be an effective way to improve the lubrication performance of friction surfaces. In order to obtain the optimal surface texture distribution parameters, taking the spherical crown pit texture model as the research object, and selecting the unequal rectangular control unit to establish the surface texture distribution model with different horizontal and vertical distribution distances (densities).According to the principle of fluid dynamic pressure lubrication, a two-dimensional Reynolds equation based on the N-S equation is established and solved by the multigrid method to study the effect of texture distribution parameters on the surface hydrodynamic lubrication under plane motion. The results show that when the texture unit Lx is 3.4r and the aspect ratio Ly / Lx is 0.82, the optimal oil film bearing capacity can be obtained. When the control unit of the boundary pit is appropriately increased so that the left and right sides of the pit at the boundary are about 3.4r, the oil film pressure stability can be effectively improved.
Research on the Significant Effect of Nozzle’s Structure on Air Outlet Speed Based on Numerical Simulation
Authors: Hao Guangfa , Zhang Chengliang , Sun Kang , Li Lei , Zhou Jun 
Published: August 2020

Abstract
Aiming at the problems of short spray distance and poor atomization effect in pesticide spraying. In addition, in order to enhance the initial velocity of the droplets and the secondary atomization of the droplets, a new air-driven combined electrostatic nozzle based on the Venturi effect is designed in this paper. And a method for accelerating and atomizing mist droplets using the Venturi effect is proposed. Combined with the distribution of airflow from the venturi, the acceleration and atomization effects of the nozzle were verified and analyzed. Using the factor design test method, three structural parameters, namely the distance A from the nozzle outlet to the venturi mouth, the retracting radius B of the venturi mouth, and the extension distance C of the venturi mouth were tested, and the following conclusions were drawn. At the 1% significance level, the single factors A, B, and C have significant effects on the average velocity of the venturi throat. The interaction of two factors, AB, AC, and BC, had no significant effect on the average velocity of the venturi throat. The interaction of three factors ABC has a significant effect on the average velocity of the venturi throat.
High-fidelity Numerical Study on Air-tightness Detection System of Medicine Box
Authors: Mao Changyong , Wu Weimin , Xie Yangjun , Dai Jiushuang , Zhao Qilin , Dai Qiuhong 
Published: August 2020

Abstract
Planning an automatic detection system of the air tightness of medicine box is very necessary for growing demand for storage of pharmaceutical products. In this study, the high-fidelity CFD study is performed for the air tightness of the medicine box, using the LBM algorithm. The high-fidelity results indicate that after about 5.24 s, the stable value of the average static pressure of the ring cavity remains at about -9414 Pa. The slit flow in the early stage of micro-leakage is very complicated, especially for the initial stage. The location of the micro-leakage is concentrated in the directions of 1 o’clock, 4 o’clock, 7 o’clock and 11 o’clock along such edge of the end cap, therefore, the sealed end cover needs to be further improved. Additionally, the idea of this research work can provide a good basis and reference for the subsequent series of related airtightness studies.