bluuebunny/crossref_metadata_2025_split huggingface dataset:
How do oil prices and investments impact the dynamics of firm value?
Authors: Khan Aima , Qureshi Muhammad Azeem , Davidsen Pål Ingebrigt 
Published: June 2020

AbstractThe purpose of this study is twofold: (i) to analyze the impact of investment policy decision on the firm value given the uncertain oil and gas prices and (ii) to propose policies that enhance firm value. The study develops a system dynamics model that integrates the financial and operational activities of oil firms. The simulation results reveal that, when oil and gas prices increase, positive future expectations lead to increased investments and reduced cash flows. Greater volume of investments over the firm's current investment policy decreases its future cash flows and the total firm value over the first 20 years of the simulation period; it increases thereafter. To support higher investments, the firm would issue a higher number of shares, and consequently the market price per share would be lower, and vice versa. The simulation results suggest a relatively lower volume of investments to increase the market price per share.© 2020 The Authors. System Dynamics Review published by John Wiley & Sons Ltd on behalf of System Dynamics Society
Graphical approaches for the control of generalized error rates
Authors: Robertson David S. , Wason James M. S. , Bretz Frank 
Published: June 2020

When simultaneously testing multiple hypotheses, the usual approach in the context of confirmatory clinical trials is to control the familywise error rate (FWER), which bounds the probability of making at least one false rejection. In many trial settings, these hypotheses will additionally have a hierarchical structure that reflects the relative importance and links between different clinical objectives. The graphical approach of Bretz et al (2009) is a flexible and easily communicable way of controlling the FWER while respecting complex trial objectives and multiple structured hypotheses. However, the FWER can be a very stringent criterion that leads to procedures with low power, and may not be appropriate in exploratory trial settings. This motivates controlling generalized error rates, particularly when the number of hypotheses tested is no longer small. We consider the generalized familywise error rate (k‐FWER), which is the probability of making kor more false rejections, as well as the tail probability of the false discovery proportion (FDP), which is the probability that the proportion of false rejections is greater than some threshold. We also consider asymptotic control of the false discovery rate, which is the expectation of the FDP. In this article, we show how to control these generalized error rates when using the graphical approach and its extensions. We demonstrate the utility of the resulting graphical procedures on three clinical trial case studies.
Recent Advances in the Protection of Amine Functionality: A Review
Authors: Omprakash Rathi Jyoti , Subray Shankarling Ganapati 
Published: June 2020

AbstractSelective protection of −NH2 functionality has enormous utility and significance in organic synthesis. Amines are nucleophile and basic in nature thus vulnerable to react with an extensive range of reagents, especially oxidizing, alkylating, and carbonyl compounds and therefore can require protection to mask these properties in the multifunctional molecule during chemical reactions. Protection of amine functionality finds important application in peptide synthesis, thus several methodologies have been developed for N‐Protection reaction. Herein, we have reviewed recent advances in the protection of amines (from 2012 till present) in the hope that this will update the current body of knowledge and aid researchers working in this area.
Synthesis of Ag2O‐SnO2 and SnO2‐Ag2O Nanocomposites and Investigation on Photocatalytic Performance under Direct Sun Light
Authors: Kumar M. Rajesh , Murugadoss G. , Venkatesh N. , Sakthivel P. 
Published: June 2020

AbstractAg2O‐SnO2 and SnO2‐Ag2O nanocomposites were successfully synthesized by a facile one‐step chemical precipitation method. The microstructural features of nanocomposites were characterized by X‐Ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high‐resolution transmission electron microscopy (HR‐TEM), Fourier transform infrared spectroscopy (FT‐IR), UV‐visible (UV‐vis) and Photoluminescence (PL) spectroscopy. The SnO2‐Ag2O showed enhanced PL emission than the Ag2O‐SnO2 nanocomposite. Photocatalytic activity of the nanocomposites was studied for methylene blue (MB) and methyl orange (MO) dyes under sun light. The Ag2O‐SnO2 nanocomposite showed excellent photocatalytic activity for the degradation of both dyes. The high photocatalytic activity of Ag2O‐SnO2 could be ascribed to the enhanced charge separation derived from the coupling of Ag2O with SnO2 due to the potential energy differences between Ag2O and SnO2, which would promote interfacial charge‐transfer relative to that of charge carrier recombination.
Ruthenium Nanoparticles Supported on Reduced Graphene Oxide: Efficient Catalyst for the Catalytic Reduction of Cr(VI) in the Presence of Amine‐Boranes
Authors: Yurderi Mehmet , Bulut Ahmet , Kanberoglu Gulsah Saydan , Kaya Murat , Kanbur Yasin , Zahmakiran Mehmet 
Published: June 2020

AbstractHexavalent chromium (Cr(VI)) is a toxic, mutagen and carcinogen contaminant exist in surface and groundwater, while its reduced form trivalent chromium (Cr(III)) is known as an essential element to normal carbohydrate, lipid and protein metabolism in nature. Addressed herein, for the first time, ruthenium nanoparticles supported on reduced graphene oxide (Ru@rGO) catalyze the reduction of aqueous Cr(VI) to Cr(III) in the presence of amine‐boranes; ammonia‐borane (AB; NH3BH3), methylamine‐borane (MeAB; CH3NH2BH3), dimethylamine‐borane (DMAB; (CH3)2NHBH3) as reducing agents under mild conditions (at room temperature and under air). Ru@rGO catalyst was reproducibly fabricated through a double‐solvent method followed by wet‐chemical reduction and characterized by using various spectroscopic and visualization techniques, which showed that the formation of well‐dispersed and highly crystalline ruthenium(0) nanoparticles with a mean particle size of 2.7 ± 0.9 nm on the surface of rGO. The catalytic performance of Ru@rGO was investigated in terms of activity and stability in the ammonia‐borane assisted reduction of Cr(VI) to Cr(III), and the sum of the results gained from these catalytic tests revealed that Ru@rGO acts as both active (TOF=7.6 mol Cr2O72−/mol Ru.min) and stable (80% of its initial activity at 90% conversion at 5th reuse) heterogeneous catalyst in this significant catalytic transformation. This study also reports kinetic studies for Ru@rGO catalyzed Cr(VI) reduction in the presence of ammonia‐borane depending on ruthenium ([Ru]), ammonia‐borane ([AB]) concentrations and temperature to shed some light on the nature of the catalytic reaction and activation parameters.
Microwave‐Assisted Regioselective Friedel–Crafts Arylation by BF3 ⋅ OEt2: A Facile Synthetic Access to 3‐Substituted‐3‐Propargyl Oxindole Scaffolds
Authors: Laxmikeshav Kritika , Sakla Akash P. , Rasane Sai , John Stephy Elza , Shankaraiah Nagula 
Published: June 2020

AbstractA facile microwave‐assisted synthetic strategy for the construction of C–C bond via regioselective Friedel–Crafts arylation of 3‐hydroxy‐3‐phenylethynyl oxindoles with different electron‐rich nucleophiles such as phenols, sulphonamides, anisole, benzofuran, and benzothiophene has been established by employing BF3 ⋅ OEt2 as catalyst. The current protocol attributes mild conditions, cost‐effective, transition‐metal free synthesis, wide substrate scope and moderate to good yields. Moreover, this method is amenable for the generation of a library of densely substituted 3‐(4‐hydroxyphenyl)‐3‐(phenylethynyl) oxindoles and 3‐(4‐benzenesulphonamide)‐3‐(phenylethynyl) oxindoles as privileged scaffolds.
Purification of 5‐Hydroxymethyl Furfural from Side Products of Fructose Dehydration Reaction in a Green Solvent
Authors: Pawar Hitesh S. 
Published: June 2020

Abstract5‐Hydroxymethyl furfural (5‐HMF) is a most promising biogenic platform molecule with its proven potential for the production of spectrum of fuel and chemical products. Spectrum of heterogeneous catalysts have been reported for converting C6 sugars into 5‐HMF but the separation of side products of fructose dehydration reaction is still a major challenge in the way of its commercialization. The present work reveled adsorptive separation and purification of 5‐HMF from side products such as humins, soluble polymers, degradation, and condensation products, etc. Quaternary ammonium chloride functionalized macroporous resin was employed as an adsorbent at ambient conditions by using isopropyl alcohol (IPA) as a green and low boiling point (LBP) solvent. The use of single adsorbent, solvent and ambient condition provides >98 % assay purity of 5‐HMF.
D‐Fructose‐Derived Acetonide as a Green Neutral Organocatalyst for Proficient One‐Pot and Three‐Component Preparation of 1,3‐Benzoxazine Monomers
Authors: Yıldırım Ayhan , Göker Mustafa 
Published: June 2020

AbstractA series of 1,3‐benzoxazine monomers were successfully synthesized by simple one‐pot and three‐component condensation of phenol, paraformaldehyde and varying types of primary aliphatic and aromatic amines in a molar ratio of 1 : 2 : 1 and in the presence of non‐acidic 2,3;4,5‐di‐O‐isopropylidene‐β‐D‐fructopyranose as an effective green carbohydrate based organocatalyst obtained from renewable feedstock. This multicomponent method provides a convenient fast approach for the construction of valuable 1,3‐benzoxazine monomers (8 examples) with moderate to excellent yields. The chemical structures of the synthesized benzoxazines were confirmed by FTIR,1H NMR,13C NMR spectra and elemental analysis.
Isolation of Leptospira serovar Pomona from a crested porcupine (Hystrix cristata, L., 1758)
Authors: Cilia Giovanni , Bertelloni Fabrizio , Coppola Francesca , Turchi Barbara , Biliotti Claudia , Poli Alessandro , Parisi Francesca , Felicioli Antonio , Cerri Domenico , Fratini Filippo 
Published: June 2020

AbstractPathogenic Leptospira is widespread in rodents, the most studied reservoir and the main hosts involved in its transmission. In Italy, among rodents, Hystrix cristata (crested porcupine) is the largest species and it is distributed all over the country. In this paper, the isolation and characterization of pathogenic Leptospira spp. from the kidney of H. cristata is reported for the first time. During Autumn 2018, Leptospira detection by real‐time PCR and isolation were performed from kidneys of two died female porcupines (an adult and a porcupette). Only for porcupette kidney sample, real‐time PCR for pathogenic Leptospira tested positive. The isolated strain was identified as Leptospira interrogans serogroup Pomona serovar Pomona, using the three schemes of multilocus sequence typing. The results show that H. cristata could be a Leptospira host. The infection of serovars Pomona could be related to the habitat shared with wild boar, a typical reservoir host for this serovar.
On the influence of external stochastic excitation on linear oscillators with subcritical self‐excitation and gyroscopic influence with application to brake squeal
Authors: Nguyen‐Thai M.‐T. , Wulff P. , Gräbner N. , von Wagner U. 
Published: June 2020

AbstractIn a linear analysis for brake squeal, an unwanted type of sound in the kHz‐range produced during the braking process of vehicles, usually only the stability of the system is examined. However, with the appearance of additional stochastic excitation, the vibration of a linear system with subcritical self‐excitation, i.e. having self‐excitation but due to damping still an asymptotically stable trivial solution, may be large enough to produce a squeal sound. In this paper, this hypothesis of stochastically reinforced self‐excitation is supported by a case study on a wobbling disk model for brake squeal, which includes both circulatory and gyroscopic forces. For this example, the Fokker‐Planck equation is solved and numerical integrations are performed. A short parameter study is carried out to examine the effect of damping and gyroscopic terms on these stochastically reinforced self‐excitation. The results suggest that this possibility should be considered additionally to classical explanations of brake squeal.
Prozess- und Anlagensicherheit
Authors: Hohenberger Michael , Raupenstrauch Harald 
Published: June 2020

ZusammenfassungDie Arbeitsgruppe Prozess- und Anlagensicherheit des Lehrstuhls für Thermoprozesstechnik an der Montanuniversität Leoben verfügt über umfangreiche Lehr- und Forschungskompetenzen. So wird beispielsweise zur Bestimmung sicherheitstechnischer Kenngrößen von Stäuben und Gasen ein eigens dafür ausgestattetes Labor betrieben. Die Forschungsschwerpunkte umfassen dabei die Untersuchung grundlegender Brand- und Explosionsmechanismen und den daraus folgenden Auswirkungen. Anwendung findet das Wissen in der Prävention von industriellen Katastrophen und Unfällen und deren Abwehr. Der Wissenstransfer erfolgt neben regulären Vorlesungen und Laborübungen durch einen berufsbegleitenden, postgradualen Universitätslehrgang in diesem Bereich.
Portfolio stress testing applied to commodity futures
Authors: Paraschiv Florentina , Reese Stine Marie , Ringkjøb Skjelstad Margrethe 
Published: June 2020

AbstractIn this article, we construct a portfolio of commodity futures which mimics the Dow Jones Commodity Index and perform an extensive stress testing exercise with a focus on hybrid scenarios. The increased volume of investments in commodities as financial instruments over the last decades underline the importance of a more thorough framework for stress testing of related portfolios. Our study is the first to show comparatively the marginal impact of the model choice for portfolio components versus the marginal role of tail dependence on the portfolio profit and loss in stress testing exercises. We model the distribution of returns of portfolio components with an asymmetric AR-GARCH model combined with Extreme Value Theory for extreme tails, and employ multivariate copula functions to model the time-varying joint dependence structure. Our study reveals that indeed, for a realistic stress test, a special attention should be given to the tail risk in individual commodity returns as well as to tail correlations. We also draw conclusions about parameter risk persistent in stress testing exercises. Finally yet importantly, in line with Basel IIIb, the study highlights the importance of using forward-looking hybrid and hypothetical scenarios over historical scenarios.
Impacts of epidemic outbreaks on supply chains: mapping a research agenda amid the COVID-19 pandemic through a structured literature review
Authors: Queiroz Maciel M. , Ivanov Dmitry , Dolgui Alexandre , Fosso Wamba Samuel 
Published: June 2020

AbstractThe coronavirus (COVID-19) outbreak shows that pandemics and epidemics can seriously wreak havoc on supply chains (SC) around the globe. Humanitarian logistics literature has extensively studied epidemic impacts; however, there exists a research gap in understanding of pandemic impacts in commercial SCs. To progress in this direction, we present a systematic analysis of the impacts of epidemic outbreaks on SCs guided by a structured literature review that collated a unique set of publications. The literature review findings suggest that influenza was the most visible epidemic outbreak reported, and that optimization of resource allocation and distribution emerged as the most popular topic. The streamlining of the literature helps us to reveal several new research tensions and novel categorizations/classifications. Most centrally, we propose a framework for operations and supply chain management at the times of COVID-19 pandemic spanning six perspectives, i.e., adaptation, digitalization, preparedness, recovery, ripple effect, and sustainability. Utilizing the outcomes of our analysis, we tease out a series of open research questions that would not be observed otherwise. Our study also emphasizes the need and offers directions to advance the literature on the impacts of the epidemic outbreaks on SCs framing a research agenda for scholars and practitioners working on this emerging research stream.
Substrate mediated predator–prey interactions between invasive crayfish and indigenous and non-native amphipods
Authors: Beatty C. , Mathers K. L. , Patel C. , Constable D. , Wood P. J. 
Published: June 2020

AbstractThe increasing number of taxa being translocated across the globe is leading to many non-native species encountering indigenous taxa as well as other non-native species. Environmental heterogeneity may strongly influence the spatial distribution, habitat use and refuge availability for these taxa. Using a series of 24-h mesocosm experiments we examined the predator–prey interactions between an invasive crayfish (Pacifastacus leniusculus) and four amphipod taxa, one indigenous (Gammarus pulex) and three non-native species (Crangonyx pseudogracilis, Dikerogammarus villosus and Gammarus tigrinus) to Great Britain. The potential mediating effect of physical habitat on predator–prey interactions was examined via the use of different substrate particle sizes; cobbles, gravels and, sand. Survivorship of amphipods in response to crayfish predation varied significantly with the highest rates recorded for the non-native species D. villosus, followed by G. tigrinus, and C. pseudogracilis, with the lowest survivorship recorded for the indigenous species G. pulex for all substrates except cobble. However, total biomass consumption of the indigenous G. pulex and the non-native D. villosus by P. leniusculus were similar suggesting that crayfish may have been satiated by larger D. villosus individuals. Substrate size had a significant influence on the predation success of P. leniusculus, with larger substrate clasts typically resulting in increased survivorship rates for all species except C. pseudogracilis, which displayed lower predation rates for sand substrates. The findings of this study highlight the risks that naïve indigenous taxa may face from new invasive species and the importance of characterising physical habitat (complexity and refugia potential) when considering the potential ecological effects of invaders on predation success.
Describing and Processing Topology and Quality of Service Parameters of Applications in the Cloud
Authors: Pierantoni Gabriele , Kiss Tamas , Terstyanszky Gabor , DesLauriers James , Gesmier Gregoire , Dang Hai-Van 
Published: June 2020

AbstractTypical cloud applications require high-level policy driven orchestration to achieve efficient resource utilisation and robust security to support different types of users and user scenarios. However, the efficient and secure utilisation of cloud resources to run applications is not trivial. Although there have been several efforts to support the coordinated deployment, and to a smaller extent the run-time orchestration of applications in the Cloud, no comprehensive solution has emerged until now that successfully leverages applications in an efficient, secure and seamless way. One of the major challenges is how to specify and manage Quality of Service (QoS) properties governing cloud applications. The solution to address these challenges could be a generic and pluggable framework that supports the optimal and secure deployment and run-time orchestration of applications in the Cloud. A specific aspect of such a cloud orchestration framework is the need to describe complex applications incorporating several services. These application descriptions must specify both the structure of the application and its QoS parameters, such as desired performance, economic viability and security. This paper proposes a cloud technology agnostic approach to application descriptions based on existing standards and describes how these application descriptions can be processed to manage applications in the Cloud.
To what extent is the Chinese housing boom driven by competition in the marriage market?
Authors: Yang Siyao , Guariglia Alessandra , Horsewood Nicholas 
Published: June 2020

AbstractWe use the 2011 and 2013 waves of the China Household Finance Survey (CHFS) to study the extent to which the acquisition of multiple houses is determined by the presence of male children in the family. We conjecture that, as a result of the very high sex ratio which can be observed in China following the one child policy, Chinese families who have a son may want to acquire additional dwellings to enhance the marriage chances of their son. In support of this argument, we find that families with male children aged 25 or older are most likely to acquire additional houses. This effect is highest in regions characterised by higher sex ratios, especially in rural areas.
Tolerance and asymptotic modelling of dynamic thermoelasticity problems for thin micro-periodic cylindrical shells
Authors: Tomczyk Barbara , Gołąbczak Marcin 
Published: June 2020

AbstractThe problem of linear dynamic thermoelasticity in Kirchhoff–Love-type circular cylindrical shells having properties periodically varying in circumferential direction (uniperiodic shells) is considered. In order to describe thermoelastic behaviour of such shells, two mathematical averaged models are proposed—the non-asymptotic tolerance and the consistent asymptotic models. Considerations are based on the known Kirchhoff–Love theory of elasticity combined with Duhamel-Neumann thermoelastic constitutive relations and on Fourier’s theory of heat conduction. The non-asymptotic tolerance model equations depending on a cell size are derived applying the tolerance averaging technique and a certain extension of the known stationary action principle. The consistent asymptotic model equations being independent on a microstructure size are obtained by means of the consistent asymptotic approach. Governing equations of both the models have constant coefficients, contrary to starting shell equations with periodic, non-continuous and oscillating coefficients. As examples, two special length-scale problems will be analysed in the framework of the proposed models. The first of them deals with investigation of the effect of a cell size on the shape of initial distributions of temperature micro-fluctuations. The second one deals with study of the effect of a microstructure size on the distribution of total temperature field approximated by sum of an averaged temperature and temperature fluctuations.
Numerical investigation of parametric resonance due to hydrodynamic coupling in a realistic wave energy converter
Authors: Giorgi Giuseppe , Gomes Rui P. F. , Bracco Giovanni , Mattiazzo Giuliana 
Published: June 2020

AbstractRepresentative models of the nonlinear behavior of floating platforms are essential for their successful design, especially in the emerging field of wave energy conversion where nonlinear dynamics can have substantially detrimental effects on the converter efficiency. The spar buoy, commonly used for deep-water drilling, oil and natural gas extraction and storage, as well as offshore wind and wave energy generation, is known to be prone to experience parametric resonance. In the vast majority of cases, parametric resonance is studied by means of simplified analytical models, considering only two degrees of freedom (DoFs) of archetypical geometries, while neglecting collateral complexity of ancillary systems. On the contrary, this paper implements a representative 7-DoF nonlinear hydrodynamic model of the full complexity of a realistic spar buoy wave energy converter, which is used to verify the likelihood of parametric instability, quantify the severity of the parametrically excited response and evaluate its consequences on power conversion efficiency. It is found that the numerical model agrees with expected conditions for parametric instability from simplified analytical models. The model is then used as a design tool to determine the best ballast configuration, limiting detrimental effects of parametric resonance while maximizing power conversion efficiency.