bluuebunny/crossref_metadata_2025_split huggingface dataset:
Auditoría tecnoética para el uso sostenible de plataformas digitales en Educación Primaria
Authors: Gonzalez-Mingot Sandra , Marín Victoria I. 
Published: September 2024

El uso extendido de las plataformas digitales en la educación primaria conlleva implicaciones problemáticas a nivel ético y sostenible como la generación y el uso de los datos que beneficia a agentes aparentemente externos del proceso de enseñanza y aprendizaje. Sin embargo, son pocas las investigaciones y soluciones prácticas en este nivel educativo. Presentamos una auditoría tecnoética testeada por el claustro de una escuela de Cataluña para fomentar la reflexión sobre las cuestiones sociales, comerciales, ambientales y pedagógicas que supone el uso de la tecnología en la educación. Los resultados muestran una valoración tecnoética negativa de las plataformas utilizadas en el estudio de caso. Además, se ha evidenciado un nivel escaso de concienciación que ha mejorado tras la auditoría, generando conocimiento sobre los metadatos o datos ocultos, la accesibilidad e inclusividad de las plataformas, su impacto medioambiental, los intereses comerciales de los Bigtech como empresas proveedoras, y la justificación pedagógica entrelazada de su uso. A la luz de los resultados y apoyándonos en la bibliografía sobre el tema, proponemos recomendaciones para la administración, la escuela y los docentes a modo de conclusiones que garanticen el uso ético y sostenible de las plataformas digitales.
Impact of Tax-based Revenue on Economic Development in Nigeria, 1999 to 2023
Authors: Emughedi OGHU, , Faith Chidinma LAWAL, , Kalu Ebere Ume 
Published: September 2024

This research measures the contributory impact of Tax-based revenue on economic development in Nigeria, 1999 to 2023, with a specific focus on the nuanced dynamics of oil-based tax (OBT), non-oil-based tax (NOBT), and aggregate tax revenue (ATR). Leveraging comprehensive data extracted from the Central Bank of Nigeria's Statistical Bulletin and Federal Inland Revenue Service (FIRS) database, the study employs the Autoregressive Distributed Lag Model (ARDL) with Gross Domestic Product Growth Per Capital (GDPPC) as the outcome variable. The empirical analysis supports a significant and positive impact of non-oil-based tax revenue on GDPG while the oil-based tax shares no significant impact on economic development. Also, aggregate tax revenue (ATR) was found to negatively but significantly impact on economic development. The study recommends the adjustment of the tax system to address the developmental constraint on investment and consumption posed by taxation while optimizing the benefits that accrue from an efficient and good tax system.
Adaptive measurements of urban runoff quality
Authors: Wong Brandon P. , Kerkez Branko 
Published: November 2016

AbstractAn approach to adaptively measure runoff water quality dynamics is introduced, focusing specifically on characterizing the timing and magnitude of urban pollutographs. Rather than relying on a static schedule or flow‐weighted sampling, which can miss important water quality dynamics if parameterized inadequately, novel Internet‐enabled sensor nodes are used to autonomously adapt their measurement frequency to real‐time weather forecasts and hydrologic conditions. This dynamic approach has the potential to significantly improve the use of constrained experimental resources, such as automated grab samplers, which continue to provide a strong alternative to sampling water quality dynamics when in situ sensors are not available. Compared to conventional flow‐weighted or time‐weighted sampling schemes, which rely on preset thresholds, a major benefit of the approach is the ability to dynamically adapt to features of an underlying hydrologic signal. A 28 km2 urban watershed was studied to characterize concentrations of total suspended solids (TSS) and total phosphorus. Water quality samples were autonomously triggered in response to features in the underlying hydrograph and real‐time weather forecasts. The study watershed did not exhibit a strong first flush and intraevent concentration variability was driven by flow acceleration, wherein the largest loadings of TSS and total phosphorus corresponded with the steepest rising limbs of the storm hydrograph. The scalability of the proposed method is discussed in the context of larger sensor network deployments, as well the potential to improving control of urban water quality.
Elemental changes and alteration recorded by basaltic drill core samples recovered from in situ temperatures up to 345°C in the active, seawater‐recharged Reykjanes geothermal system, Iceland
Authors: Fowler Andrew P. G. , Zierenberg Robert A. 
Published: November 2016

AbstractHydrothermal activity results in element exchanges between seawater and oceanic crust that contribute to many aspects of ocean chemistry; therefore, improving knowledge of the associated chemical processes is of global significance. Hydrothermally altered basaltic drill core samples from the seawater‐recharged Reykjanes geothermal system in Iceland record elemental gains and losses similar to those observed in samples of hydrothermally altered oceanic crust. At Reykjanes, rocks originally emplaced on the seafloor were buried by continued volcanism and subsided to the current depths (>2250 m below surface). These rocks integrate temperature‐dependent elemental gains and losses from multiple stages of hydrothermal alteration that correspond to chemical exchanges observed in rocks from different crustal levels of submarine hydrothermal systems. Specifically, these lithologies have gained U, Mg, Zn, and Pb and have lost K, Rb, Ba, Cu, and light rare earth elements (La through Eu). Alteration and elemental gains and losses in lithologies emplaced on the seafloor can only be explained by a complex multistage hydrothermal alteration history. Reykjanes dolerite intrusions record alteration similar to that reported for the sheeted dike section of several examples of oceanic crust. Specifically, Reykjanes dolerites have lost K, Rb, Ba, and Pb, and gained Cu. The Reykjanes drill core samples provide a unique analog for seawater‐oceanic crust reactions actively occurring at high temperatures (275–345°C) beneath a seafloor hydrothermal system.
A quasi‐liquid mediated continuum model of faceted ice dynamics
Authors: Neshyba Steven , Adams Jonathan , Reed Kelsey , Rowe Penny M. , Gladich Ivan 
Published: November 2016

AbstractWe present a quasi‐liquid mediated continuum model for ice growth consisting of partial differential equations informed by molecular dynamics simulations. The main insight from molecular dynamics is the appearance of periodic variations in the equilibrium vapor pressure and quasi‐liquid thickness of the ice/vapor interface. These variations are incorporated in the continuum model as subgrid scale microsurfaces. We show that persistent faceted ice growth in the presence of inhomogeneities in the ambient vapor field is due to a spontaneous narrowing of terraces at facet corners, which compensates for higher ambient water vapor density via feedback between surface supersaturation and quasi‐liquid thickness. We argue that this emergent behavior has the mathematical structure of a stable limit cycle and characterize its robustness in terms of ranges of parameters that support it. Because the model is relevant in the high‐surface‐coverage regime, it serves as a useful complement to the Burton‐Cabrera‐Frank framework. Quantitative aspects and limitations of the model are also discussed.
Ambient observations of hygroscopic growth factor and f(RH) below 1: Case studies from surface and airborne measurements
Authors: Shingler Taylor , Sorooshian Armin , Ortega Amber , Crosbie Ewan , Wonaschütz Anna , Perring Anne E. , Beyersdorf Andreas , Ziemba Luke , Jimenez Jose L. , Campuzano‐Jost Pedro , Mikoviny Tomas , Wisthaler Armin , Russell Lynn M. 
Published: November 2016

AbstractThis study reports a detailed set of ambient observations of optical/physical shrinking of particles from exposure to water vapor with consistency across different instruments and regions. Data have been utilized from (i) a shipboard humidified tandem differential mobility analyzer during the Eastern Pacific Emitted Aerosol Cloud Experiment in 2011, (ii) multiple instruments on the NASA DC‐8 research aircraft during the Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys in 2013, and (iii) the Differential Aerosol Sizing and Hygroscopicity Spectrometer Probe during ambient measurements in Tucson, Arizona, during summer 2014 and winter 2015. Hygroscopic growth factor (ratio of humidified‐to‐dry diameter, GF = Dp,wet/Dp,dry) and f(RH) (ratio of humidified‐to‐dry scattering coefficients) values below 1 were observed across the range of relative humidity (RH) investigated (75–95%). A commonality of observations of GF and f(RH) below 1 in these experiments was the presence of particles enriched with carbonaceous matter, especially from biomass burning. Evidence of externally mixed aerosol, and thus multiple GFs with at least one GF < 1, was observed concurrently with f(RH) < 1 during smoke periods. Possible mechanisms responsible for observed shrinkage are discussed and include particle restructuring, volatilization effects, and refractive index modifications due to aqueous processing resulting in optical size modification. To further investigate ambient observations of GFs and f(RH) values less than 1, it is recommended to add an optional prehumidification bypass module to hygroscopicity instruments, to preemptively collapse particles prior to controlled RH measurements.
Evidence for geologic processes on comets
Authors: Sunshine Jessica M. , Thomas Nicolas , El‐Maarry Mohamed Ramy , Farnham Tony L. 
Published: November 2016

AbstractSpacecraft missions have resolved the nuclei of six periodic comets and revealed a set of geologically intriguing and active small bodies. The shapes of these cometary nuclei are dominantly bilobate reflecting their formation from smaller cometesimals. Cometary surfaces include a diverse set of morphologies formed from a variety of mechanisms. Sublimation of ices, driven by the variable insolation over the time since each nucleus was perturbed into the inner Solar System, is a major process on comets and is likely responsible for quasi‐circular depressions and ubiquitous layering. Sublimation from near‐vertical walls is also seen to lead to undercutting and mass wasting. Fracturing has only been resolved on one comet but likely exists on all comets. There is also evidence for mass redistribution, where material lifted off the nucleus by subliming gases is deposited onto other surfaces. It is surprising that such sedimentary processes are significant in the microgravity environment of comets. There are many enigmatic features on cometary surfaces including tall spires, kilometer‐scale flows, and various forms of depressions and pits. Furthermore, even after accounting for the differences in resolution and coverage, significant diversity in landforms among cometary surfaces clearly exists. Yet why certain landforms occur on some comets and not on others remains poorly understood. The exploration and understanding of geologic processes on comets is only beginning. These fascinating bodies will continue to provide a unique laboratory for examining common geologic processes under the uncommon conditions of very high porosity, very low strength, small particle sizes, and near‐zero gravity.
An analytical approach for the simulation of flow in a heterogeneous confined aquifer with a parameter zonation structure
Authors: Huang Ching‐Sheng , Yeh Hund‐Der 
Published: November 2016

AbstractThis study introduces an analytical approach to estimate drawdown induced by well extraction in a heterogeneous confined aquifer with an irregular outer boundary. The aquifer domain is divided into a number of zones according to the zonation method for representing the spatial distribution of a hydraulic parameter field. The lateral boundary of the aquifer can be considered under the Dirichlet, Neumann or Robin condition at different parts of the boundary. Flow across the interface between two zones satisfies the continuities of drawdown and flux. Source points, each of which has an unknown volumetric rate representing the boundary effect on the drawdown, are allocated around the boundary of each zone. The solution of drawdown in each zone is expressed as a series in terms of the Theis equation with unknown volumetric rates from the source points. The rates are then determined based on the aquifer boundary conditions and the continuity requirements. The estimated aquifer drawdown by the present approach agrees well with a finite element solution developed based on the Mathematica function NDSolve. As compared with the existing numerical approaches, the present approach has a merit of directly computing the drawdown at any given location and time and therefore takes much less computing time to obtain the required results in engineering applications.
Spatiotemporal requirements of the Hainan gibbon: Does home range constrain recovery of the world's rarest ape?
Authors: Bryant Jessica V. , Zeng Xingyuan , Hong Xiaojiang , Chatterjee Helen J. , Turvey Samuel T. 
Published: November 2016

Conservation management requires an evidence‐based approach, as uninformed decisions can signify the difference between species recovery and loss. The Hainan gibbon, the world's rarest ape, reportedly exploits the largest home range of any gibbon species, with these apparently large spatial requirements potentially limiting population recovery. However, previous home range assessments rarely reported survey methods, effort, or analytical approaches, hindering critical evaluation of estimate reliability. For extremely rare species where data collection is challenging, it also is unclear what impact such limitations have on estimating home range requirements. We re‐evaluated Hainan gibbon spatial ecology using 75 hr of observations from 35 contact days over 93 field‐days across dry (November 2010–February 2011) and wet (June 2011–September 2011) seasons. We calculated home range area for three social groups (N = 21 individuals) across the sampling period, seasonal estimates for one group (based on 24 days of observation; 12 days per season), and between‐group home range overlap using multiple approaches (Minimum Convex Polygon, Kernel Density Estimation, Local Convex Hull, Brownian Bridge Movement Model), and assessed estimate reliability and representativeness using three approaches (Incremental Area Analysis, spatial concordance, and exclusion of expected holes). We estimated a yearly home range of 1–2 km2, with 1.49 km2 closest to the median of all estimates. Although Hainan gibbon spatial requirements are relatively large for gibbons, our new estimates are smaller than previous estimates used to explain the species’ limited recovery, suggesting that habitat availability may be less important in limiting population growth. We argue that other ecological, genetic, and/or anthropogenic factors are more likely to constrain Hainan gibbon recovery, and conservation attention should focus on elucidating and managing these factors.RESEARCH HIGHLIGHTS
Re‐evaluation reveals Hainan gibbon home range as c. 1–2 km2.
Hainan gibbon home range is, therefore, similar to other Nomascus gibbons.
Limited data for extremely rare species does not necessarily prevent derivation of robust home range estimates.
Bioinspired Total Synthesis of the Dimeric Indole Alkaloid (+)‐Haplophytine by Direct Coupling and Late‐Stage Oxidative Rearrangement
Authors: Satoh Hitoshi , Ojima Ken‐ichi , Ueda Hirofumi , Tokuyama Hidetoshi 
Published: November 2016

AbstractA bioinspired convergent total synthesis of (+)‐haplophytine, a dimeric indole alkaloid with diazabicyclo[3.3.1]nonane and hexacyclic aspidosperma segments, is described. This synthesis involves the direct coupling of the two segments in a AgNTf2‐mediated Friedel–Crafts reaction and construction of the diazabicyclo[3.3.1]nonane skeleton through late‐stage chemoselective aerobic oxidation of the 1,2‐diaminoethene moiety and a sequential semipinacol‐type rearrangement.
Chemical vapour deposition of platinum films on electrodes for pacemakers: Novel precursors and their thermal properties
Authors: Dorovskikh Svetlana I. , Zharkova Galina I. , Turgambaeva Asiya E. , Krisyuk Vladislav V. , Morozova Natalia B. 
Published: November 2016

Air‐stable trimethylplatinum(IV) β‐diketonate complexes of general formula (CH3)3Pt(L)Py (L = R1COCHCOR2; R1 = R2 = CF3 (hfac), tBu (thd), CH3 (acac); R1 = CF3, R2 = tBu (ptac), CH3 (tfac); Py = pyridine) have been synthesized in high yields. The thermal properties of (CH3)3Pt(L)Py were investigated using thermogravimetry/differential thermal analysis and flow method to demonstrate their suitability as metal–organic chemical vapour deposition precursors. Thermolysis of vaporized (CH3)3Pt(acac)Py in vacuum and in the presence of hydrogen or oxygen was studied under conditions of low‐pressure chemical vapour deposition using an original technique. Using this precursor, Pt films were deposited on electrodes for pacemakers under various conditions. The composition, structure, morphology and electrochemical properties of the deposited films were investigated using X‐ray diffraction, X‐ray photoelectron spectroscopy, scanning electron microscopy and cyclic voltammetry and LCR measurements. Pt films deposited in the presence of oxygen have a fractal‐like morphology as a result the highest values of real surface areas (851–943 mm2) and capacity (5–8.5 μF mm−2).
Cure and scorch in the processing of ethylene‐propylene‐diene terpolymer (EPDM)
Authors: Saleesung Thanisararat , Saeoui Pongdhorn , Sirisinha Chakrit 
Published: November 2016

ABSTRACTThe objective of this work is to ascertain the characteristics of desirable (cure) and especially undesirable (scorch) crosslinking when carbon black filled ethylene propylene diene terpolymer (EPDM) is processed using different peroxide initiators. The mixing temperature and the nature of the peroxide initiator are crucial parameters affecting scorch (undesirably premature crosslinking) in this rubber. Processability and properties of EPDM prepared using various mixer set temperatures have been investigated. Dicumyl peroxide (Luperox DC), di(t‐butylperoxy) diisopropylbenzene (Luperox F), and 2,5‐dimethyl‐2,5‐di(t‐butylperoxy) hexane (Luperox 101) were used as crosslinking initiators. Higher mixing temperatures give shorter scorch times, greater scorch magnitudes, greater heterogeneities in crosslink spatial distribution and poorer tensile properties. However, extreme localization of the unwanted crosslinking at the rubber‐filler interface does have a beneficial effect. Luperox DC offers poorer processability and poorer resulting properties than do Luperox F and Luperox 101, due to its shorter half‐life and greater solubility in the rubber phase. This is the first time that the spatial heterogeneity of crosslinking and scorch has been related to the basic thermodynamics of 3‐component 2‐phase systems. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44523.
Distributed Observer‐based Stabilization of Nonlinear Multi‐agent Systems with Sampled‐data Control
Authors: Wan Ying , Cao Jinde , Alsaedi Ahmed , Hayat Tasawar 
Published: November 2016

AbstractIn this paper, the distributed observer‐based stabilization problem of multi‐agent systems under a directed graph is investigated. Distributed observer‐based control protocol with sampled‐data information is proposed. The dynamics of each agent contain a nonlinear part, which is supposed to be general Lipschitz. In order to stabilize the states of the whole network, all the nodes utilize the relative output estimation error at sampling instants and only a small fraction of nodes use the absolute output estimation error additionally. By virtue of the input‐to‐state stability (ISS) property and the Lyapunov stability theory, an algorithm to design the control gain matrix, observer gain matrix, coupling strength as well as the allowable sampling period are derived. The conditions are in the form of LMIs and algebraic inequality, which are simple in form and easy to verify. Some further discussions about the solvability of obtained linear matrix inequalities (LMIs) are also given. Lastly, an example is simulated to further validate the obtained results.
Functional Analysis of Catalysts for Lower Alkane Oxidation
Authors: Kube Pierre , Frank Benjamin , Wrabetz Sabine , Kröhnert Jutta , Hävecker Michael , Velasco‐Vélez Juan , Noack Johannes , Schlögl Robert , Trunschke Annette 
Published: November 2016

AbstractThe catalytic performance of 1) crystalline MoVTeNb oxide that exhibits the electronic properties of a n‐type semiconductor, 2) submonolayer vanadium oxide supported on meso‐structured silica (SBA‐15) as an insulating support, and 3) surface‐functionalized carbon nanotubes that contain neither a redox active metal nor bulk oxygen, but only surface oxygen species have been compared in the oxidative dehydrogenation of ethane and propane under equal reaction conditions. The catalytic results indicate similarities in the reaction network over all three catalysts within the range of the studied reaction conditions implying that differences in selectivity are a consequence of differences in the rate constants. Higher activity and selectivity to acrylic acid over MoVTeNb oxide as compared to the other two catalysts are attributed to the higher density of potential alkane adsorption sites on M1 and the specific electronic structure of the semiconducting bulk catalyst. Microcalorimetry has been used to determine and quantify different adsorption sites revealing a low Vsurface/C3H8 ads ratio of 4 on M1 and a much higher ratio of 150 on silica‐supported vanadium oxide. On the latter catalyst less than one per cent of the vanadium atoms adsorb propane. Barriers of propane activation increase in the order P/oCNT (139 kJ mol−1)≤M1 (143 kJ mol−1)<6V/SBA‐15 (162 kJ mol−1), which is in agreement with trends predicted by theory.
Cross‐Dehydrogenative‐Coupling of Alkoxybenzenes with Toluenes: Copper(II) Halide Mediated Tandem Halo/Benzylation of Arenes
Authors: Storr Thomas E. , Teskey Christopher J. , Greaney Michael F. 
Published: November 2016

AbstractA cross‐dehydrogenative‐coupling of alkoxybenzenes and toluenes with concomitant halogenation is reported. Conditions employed were the use of stoichiometric copper halide salts and dialkylperoxides to afford a range of bromoalkoxydi‐ and triarylmethanes. Preliminary mechanistic studies suggest that the in situ production of haloarenes (or dihaloarenes) followed by a copper‐mediated coupling of a benzylic radical is operational.
Solution Chemistry of N,N’‐Disubstituted Amidines: Identification of Isomers and Evidence for Linear Dimer Formation
Authors: Kalz Kai F. , Hausmann Anja , Dechert Sebastian , Meyer Steffen , John Michael , Meyer Franc 
Published: November 2016

AbstractAmidines have found widespread use, but their solution chemistry remains poorly understood. In this work, X‐ray crystallographic and detailed 1D and 2D NMR spectroscopic studies have been performed to elucidate the preferred isomers and their interconversion mechanisms. Amidines are shown to exist as a mixture of E‐syn and Z‐anti isomers in solution and to form dimeric H‐bonded aggregates that are also observed in the solid state. Rapid proton exchange/tautomerization reactions occur within the dimers, allowing fast interconversion of E‐syn and Z‐anti isomers even at very low temperatures. Three different exchange processes were identified in solution, and on this basis the unusual concentration and temperature dependence of the NMR spectra of these amidines could be explained. This work thus resolves some of the puzzles of the complex solution chemistry of this prominent class of compounds.