bluuebunny/crossref_metadata_2025_split huggingface dataset:
Catalytic Action of Submicrometer Spherical Ta/Ph‐Fe on Combustion of AP/HTPB Propellant
Authors: Song Naimeng , Liu Jianchao , Zhang Guoying , Yan Zhenzhan , Gao Hongxu , Yang Li 
Published: June 2018

AbstractThis paper describes the preparation of two combustion catalysts Tannin‐Fe (Ta−Fe) and Phloroglucinol‐Fe (Ph−Fe) by spray drying. The particle size and morphology of the particles are observed by scanning electron microscopy (SEM). The results of SEM image show that the particles are regular spherical and very good dispersion. The diameter of most spherical particles is about 1 μm. The effects of Ta−Fe and Ph−Fe on the thermal decomposition of RDX and AP were tested by differential scanning calorimeter (DSC). DSC dates show that Ta−Fe and Ph−Fe can advance the high temperature exothermic peak of AP 18.0 °C and 16.1 °C, respectively. The burning rates illustrates that both Ta−Fe and Ph−Fe can significantly increase the combustion rate of HTPB propellants. The formulation with 2 mass% Ta−Fe shows an average 21.31 % increase in burning rate and has a low value of the exponent n=0.48. The formulation with 2 mass%Ph−Fe has a burning rate 20 to 60 % larger than that of the initial AP/HTPB/Al formulation, and has a lowest exponent n=0.45.
Synthesis, Crystal Structure, and Performance of 2,2’,2’’,4,4’,4’’,6,6’,6’’‐Nonanitro‐1,1’ : 3’,1’’‐Terphenyl (NONA)
Authors: Yang Feng , Li Yong‐Xiang , Chai Xiao‐Xiao , Dang Xin 
Published: June 2018

AbstractThe famous heat‐resistant explosive‐2,2’,2’’,4,4’,4’’,6,6’,6’’‐nonanitro‐1,1’:3’,1’’‐terphenyl (NONA) was synthesized by the Ullmann reaction, and its separation and purification was achieved by the solvent‐antisolvent method and the anisole reflux method, which are more simple and easy to operate than conventional methods. The molecular structure of NONA was characterized by X‐ray single crystal diffraction, FT‐IR, 1H NMR, mass spectrometry and elemental analysis. The thermal behavior of NONA was studied by thermogravimetric‐differential scanning calorimetry (TG‐DSC), Moreover, the heats of formation, detonation properties, and bond dissociation of NONA were calculated. The results show that the NONA crystals belong to the orthorhombic system and the Pbca (61) space group where a=16.8223 (11) Å, b=11.9573 Å, c=23.0972 (14) Å, a/b=1.4069, b/c=0.5177, c/a=1.3730, V=4645.99(50) Å3, ρ=1.81644 g/cm3, Z=8, and F(000)=2560. The decomposition temperature is 364.8 °C, the calculated heats of formation is −148.2 kJ/mol, the detonation velocity and detonation pressure are 7720.66 m/s and 26.58 GPa, respectively, and the initiation bond is C(3)‐NO2 with a dissociation energy of 249.3 kJ/mol.
A Highly Selective Fluorescence Turn‐On Probe for the Sensing and Bioimaging of Hypochlorite Anion in Aqueous Media
Authors: Lohar Somenath , Patra Ayan , Roy Priya , Babu Santi P. Sinha , Chattopadhyay Pabitra 
Published: June 2018

AbstractA newly designed and structurally characterized 2,6‐diformyl −4‐methyl‐phenol based moiety detects the hypochlorite ions as low as 75.9 nM selectively in DMSO–H2O (1:9, v/v) solution (100 mM HEPES buffer, pH 7.4) based on oxidation cleavage reaction of the thioacetal linkage. To establish this reaction based pathway in favor of sensing hypochlorite ions, the detailed spectroscopic studies have been carried out systematically supported by theoretical (DFT) studies. The efficacy of this non‐cytotoxic probe has been checked by acquiring the fluorescence images of the distribution of the hypochlorite (ClO−) ion in living cells.
Understanding Selectivity in the Chlorate Process: A Step towards Efficient Hydrogen Production
Authors: Gomes Adriano S. O. , Busch Michael , Wildlock Mats , Simic Nina , Ahlberg Elisabet 
Published: June 2018

AbstractChlorate production is a highly energy demanding industrial process, where chlorate formation is accompanied with hydrogen formation on the cathode. To ensure a high cathodic current efficiency, sodium dichromate is added to the chlorate electrolyte to avoid reduction of hypochlorite formed as a reaction intermediate in the process. However, chromate is highly toxic to humans and environment, and therefore a replacement is desired. A model system with ex situ formed chromium oxide/hydroxide films were used to study hypochlorite reduction and hydrogen evolution. The experimental results demonstrate that the hypochlorite reduction is fully blocked while hydrogen evolution readily occurs. However, in the presence of hypochlorite the hydrogen evolution reaction is inhibited. By combining experimental findings with density functional theory (DFT) calculations, the mechanism of hypochlorite reduction was revealed and the reason for inhibition by the deposited chromium(III) film was demonstrated. Based on these results possible replacements for chromate are suggested.
Synthesis of PE Wax by Chromium Complexes Bearing NP Ligands
Authors: Gao Jinlong , Zhang Le , Alam Fakhre , Chen Yanhui , Jiang Tao 
Published: June 2018

AbstractThree binuclear chromium complexes stabilized by 1,5,9,13‐tetra(phosphinoamine)cyclohexadecane ligand were synthesized and characterized. In combination with TMA‐depleted methylalumoxane/triethylaluminium (DMAO/TEA) as cocatalyst, they generate active catalytic systems for ethylene polymerization to form ultra low molecular weight polyethylene (PE) wax with moderate catalytic activity in methylcyclohexane (MeCy). The molecular weight of PE wax is ranging from 612 to 841 g/mol with a narrow polydispersity (PD=1.37‐1.80). The effects of polymerization parameters, such as solvent, temperature, catalyst concentration, the ratio of cocatalyst on the catalytic activity and properties of the PE wax were also investigated.
Role of Nitrogen Precursor on the Activity Descriptor towards Oxygen Reduction Reaction in Iron‐Based Catalysts
Authors: Mathur Ankita , Harish Sivasankaran , Halder Aditi 
Published: June 2018

AbstractNitrogen‐doped carbon nanostructures supported non‐precious transition metal/metal oxide electrocatalysts are promising alternative to platinum‐based electrocatalysts for oxygen reduction reaction (ORR) of polymer electrolyte membrane fuel cell (PEMFC). In this article, a variety of nitrogen‐doped carbon‐ iron based electrocatalysts were prepared by pyrolyzing a particular nitrogen‐containing precursor compound with iron oxide at various reaction conditions using hydrothermal method. Our experimental data showed that the ratio between nitrogen containing precursor and metal ions plays significant role in determining the performance of ORR. The increase in nitrogen containing active sites is not linearly proportional to the quantity of nitrogenous precursor. Careful investigation by different spectroscopic (e. g. X‐ray photoelectron spectroscopy, Raman Spectroscopy) as well as microscopic techniques along with electrochemical studies, we can conclude that‐ (a) nitrogen precursor in the synthesis process plays significant role in determining the morphology and oxidation state of iron in final catalyst; and (b) the overall electrocatalytic behaviour of Fe‐N−C based electrocatalysts are largely dependent upon the oxidation state and morphology of catalyst.
Au/CdS Nanocomposite through Digestive Ripening of Au and CdS Nanoparticles and Its Photocatalytic Activity
Authors: Bhaskar Srilakshmi P. , Karthika Minikumari S. , Jagirdar Balaji R. 
Published: June 2018

AbstractCo‐digestive ripening is a versatile strategy for the preparation of binary metal nanoparticles such as core‐shell, composites, and alloys. The mechanism of co‐digestive ripening is hypothesized to involve inter‐atom transfer facilitated by capping agents. In this work, co‐digestive ripening of a metal (Au) and a semiconductor (CdS) system has been presented. This process involves co‐refluxing of a physical mixture of Au and CdS colloids in presence of hexadecyl amine (HDA) in mesitylene solvent. Individual colloids of Au and CdS were prepared by solvated metal atom dispersion (SMAD) method. The growth control of nanoparticles using HDA resulted in the formation of monodisperse particles via a room temperature digestive ripening process. Au/CdS nanocomposite obtained via co‐digestive ripening strategy was characterized by a matrix‐like structure made up of CdS nanoparticles in which Au nanoparticles were embedded. CdS nanoparticles were found to establish an intimate surface contact with Au nanoparticles and the matrix of CdS surrounding Au was developed via aggregation during co‐refluxing. Formation of the Au/CdS nanocomposite is proposed to involve a ligand replacement process wherein HDA molecules capping the Au surface are displaced by CdS owing to strong Au‐CdS interaction. The Au/CdS composite thus obtained showed superior photocatalytic activity compared to pure CdS nanoparticles for dye degradation reaction.
Liquid‐Phase Oxidation Reaction and Mechanism of p‐Diethylbenzene to p‐Ethylacetophenone with H2O2 in a Batch Reactor and a Fixed Bed Reactor
Authors: Xu Ruxia , Gu Jing , Zhong Wen , Liu Zongjian , Cui Qun , Wang Haiyan 
Published: June 2018

AbstractLiquid‐phase oxidation of p‐diethylbenzene (PDEB) to p‐ethylacetophenone (EAP) with hydrogen peroxide (H2O2) catalyzed by 5Co/SBA‐15 in a batch reactor and a fixed bed reactor was investigated. Based on the analysis of compositions, a reasonable reaction mechanism was discussed. Results show whether in a batch reactor or a fixed bed reactor, a mixture of EAP, 1‐(4‐ethylphenyl)‐1‐ethanol (EPEA), p‐diacetylbenzene (PDAB), 4‐acetylbenzoic acid (AA) and terephthalic acid (TA) could be detected. The reaction mechanism for oxidation of PDEB based on two reaction pathways for oxidizing ethyl group with H2O2 involving radical intermediates are proposed, PDEB firstly undergoes oxidation to give alkyl benzene carbocation and generates the key intermediate EPEA, which will be converted to EAP through pathway I. EAP can ultimately yield byproducts PDAB, AA and TA with pathway I and pathway II. Besides, diethyl group of PDEB can be tolerated pathway II to generate TA directly. The selectivity of EAP is steady around 68% in the fixed bed reactor, which is 16.52% higher than that in the batch reactor. It is essential to have a further study on the continuous flow process and obtain more data for industrial application.
Substrate‐Driven Electrochemical Stabilization and Activation of Ag Monolayers to Catalyze the Oxygen Reduction Reaction: Beyond Pt‐based Electrocatalysts
Authors: Stolbov Sergey , Ortigoza Marisol Alcántara 
Published: June 2018

AbstractThe search for inexpensive, stable and active electrocatalysts for the oxygen reduction reaction (ORR) on hydrogen fuel cell cathodes is severely limited because only expensive and scarce elements such as gold and platinum‐group elements do not dissolve or oxidize in the reaction environment at acceptable operating cathode potentials. Fortunately, the potential at which dissolution sets in for an element can be increased if a monolayer of such element strongly binds to a suitable substrate. Here, we apply the latter approach to stabilize Ag in the ORR reaction environment by placing a Ag monolayer on Nb, W, Ta, and Ru/Nb substrates. Our first principles calculations and ORR thermodynamics analysis show that all the systems are thermodynamically stable. Ag/Nb has a dissolution potential higher than that of Pt and can be as active toward ORR as Pt. Notably, the cost of Ag/Nb is strikingly lower than that of any Pt‐based ORR catalyst.
GFP Chromophores from L‐Phenylalanine: Synthesis, Photophysical and Thermal Properties
Authors: Singh Thokchom Prasanta , Devi Thokchom Jeeta , Singh Ningthoujam Premananda , Singh Okram Mukherjee 
Published: June 2018

AbstractSynthesis of π‐conjugated green fluorescent protein chromophores analogs derived from amino acids are established. Indole and p‐nitrophenyl tethered derivatives as the main structure could improve the thermal stability and optical property of the materials. The chromophores show good solubility in MeOH and CH3CN. They also show good thermal stability for practical applications. These compounds showed steady green light emissions in the range of 524–578 nm in solution.
Synthesis of Indium Complexes for Thin Film Transistor Applications Bearing N‐Alkoxy Carboxamide Ligands
Authors: Lee Ji Hun , Jung Eun Ae , Lee Ga Yeon , Han Seong Ho , Park Bo Keun , Lee Soon Won , Son Seung Uk , Kim Chang Gyoun , Chung Taek‐Mo 
Published: June 2018

AbstractBy reacting equimolar amount of trimethylindium with various N‐alkoxy carboxamidate type‐ligands in a single step reaction, new series of indium complexes (1‐3), [In(CH3)2(L)]2 (L1H= N‐methoxypropionamide (mpaH), L2H=N‐ethoxy‐2‐methyl propanamide (empaH), L3H=N‐ethoxy‐2,2‐dimethyl propanamide (edpaH)), were successfully synthesized. All complexes were fully characterized by FTIR and NMR spectroscopy along with elemental and thermogravimetric (TG) analyses. While complex 1 and 2 were solid in room temperature, complex 3 which relatively bulkier ligand L3H was introduced was in liquid state. Among them, complex 1 was structurally characterized by single crystal X‐ray diffraction. Complex 1 existed in a tetragonal I4(1)/a space group that consist of a pair enantiomers. A sharp weight loss between 130 °C and 230 °C in a single step in TGA for all complexes showed outstanding volatility properties with lowest residual mass of 10% which are a crucial factor in thin film industry.
Automated parallel GUI testing as a service for mobile applications
Authors: Ali Amira , Maghawry Huda Amin , Badr Nagwa 
Published: June 2018

AbstractRecently, testing mobile applications is gaining much attention due to the widespread of smartphones and the tremendous number of mobile applications development. It is essential to test mobile applications before being released for the public use. Graphical user interface (GUI) testing is a type of mobile applications testing conducted to ensure the proper functionality of the GUI components. Typically, GUI testing requires a lot of effort and time whether manual or automatic. Cloud computing is an emerging technology that can be used in the software engineering field to overcome the defects of the traditional testing approaches by using cloud computing resources. As a result, testing‐as‐a‐service is introduced as a service model that conducts all testing activities in a fully automated manner. In this paper, a system for mobile applications GUI testing based on testing‐as‐a‐service architecture is proposed. The proposed system performs all testing activities including automatic test case generation and simultaneous test execution on multiple virtual nodes for testing Android‐based applications. The proposed system reduces testing time and meets fast time‐to market constraint of mobile applications. Moreover, the proposed system architecture addresses many issues such as maximizing resource utilization, continuous monitoring to ensure system reliability, and applying fault‐tolerance approach to handle occurrence of any failure.
Agile practices for global software development vendors in the development of green and sustainable software
Authors: Rashid Nasir , Khan Siffat Ullah 
Published: June 2018

AbstractOver the last decade, the use of agile methods has grown dramatically for software development. Agile methods guarantee to accelerate the delivery of remarkable software with increased user satisfaction and reduced cost. However, in recent years, due to emergence of green software engineering, software developers are compelled to focus more on green and sustainable aspects of software. Global software engineering aims to design, develop, and use a software with limited energy and computing resources. Recently, software engineers in global software development (GSD) have adapted agile methods for quick, interactive, and environment‐friendly software development. However, there is a lack of specific practices to be followed by GSD vendors in the development of green and sustainable software.In this study, we have identified 36 agile practices through systematic literature review and applied contrived search criteria derived from the research questions; 53 relevant papers were identified and reviewed. Findings of the systematic literature review were then empirically validated through questionnaire survey in GSD industry, in which 106 relevant experts from 25 different countries participated. The identified agile practices are intended to assist GSD vendors in strengthening their agile maturity towards green and sustainable software development.
One School's Yearlong Collaboration With a Children's Book Author
Authors: DeFauw Danielle L. 
Published: June 2018

AbstractMany students have experienced author visits, but one K–4 elementary school aimed to meet its school improvement goal to motivate writers through a yearlong collaboration with a published children's book author/illustrator, Ryan Hipp. This article details the positive components of the yearlong collaboration that included three in‐person sessions and blog posts. Transcribed observations of the assemblies, readings of the blog, and transcribed pre‐ and poststudy interviews of nine teachers, 36 students, and Hipp revealed that collaboration with him triggered and maintained situational interest. Students were interested in writing and motivated to write because of Hipp's influence, and the constant connection with the author/illustrator helped ensure the success of the collaboration. Teaching implications of author visits are detailed.
On the power coefficient overshoot of an offshore floating wind turbine in surge oscillations
Authors: Wen Binrong , Tian Xinliang , Dong Xingjian , Peng Zhike , Zhang Wenming 
Published: June 2018

AbstractThe Betz limit is widely accepted to be the upper limit for the power coefficient of open wind turbines. However, when investigating the power performance of an offshore floating wind turbine in surge oscillations, it is found that the Betz limit can be exceeded by the instantaneous power coefficient if the tip speed ratio is near the optimal tip speed ratio and the platform surge motion is severe enough. This exceeding phenomenon is defined as the power coefficient overshoot. Numerical simulations with the free vortex method show that the power coefficient overshoot is caused by the time lag between the power output and the wind farm power. The time lag and the resultant power coefficient overshoot intensify with the increasing platform surge frequency. Equivalent dynamic modeling analysis shows that the time lag is mainly caused by the added mass effect, which increases with the surge frequency. The time lag and the resultant power coefficient overshoot are attributed to the unsteady profile dynamics and the blade‐wake interaction. The former tends to induce the time lag to appear as a time advance in the power output when compared with the wind farm power. The latter, however, appears to induce the time lag to appear as a time delay in the power output. As the tip speed ratio increases, a shift from time advance to time delay is detected due to the decrease of the unsteady profile aerodynamics and the enhancement of the blade‐wake interaction.
Statistical challenges in estimating past climate changes
Authors: Sweeney James , Salter‐Townshend Michael , Edwards Tamsin , Buck Caitlin E. , Parnell Andrew C. 
Published: June 2018

We review the statistical methods currently in use to estimate past changes in climate. These methods encompass the full gamut of statistical modeling approaches, ranging from simple regression up to nonparametric spatiotemporal Bayesian models. Often the full inferential challenge is broken down into many submodels each of which may involve multiple stochastic components, and occasionally mechanistic or process‐based models too. We argue that many of the traditional approaches are simplistic in their structure, handling, and presentation of uncertainty, and that newer models (which incorporate mechanistic aspects alongside statistical models) provide an exciting research agenda for the next decade. We hope that policy‐makers and those charged with predicting future climate change will increasingly use probabilistic paleoclimate reconstructions to calibrate their forecasts, learn about key natural climatological parameters, and make appropriate decisions concerning future climate change. Remarkably few statisticians have involved themselves with paleoclimate reconstruction, and we hope that this article inspires more to take up the challenge.This article is categorized under:

Applications of Computational Statistics > Computational Climate Change and Numerical Weather Forecasting
Health, public sector service use and related costs of Swedish preschool children: results from the Children and Parents in Focus trial
Authors: Sampaio Filipa , Ssegonja Richard , Nystrand Camilla , Feldman Inna 
Published: June 2018

AbstractDespite Sweden’s good child health statistics, data on the mental health and wellbeing of Swedish preschool children is scarce and not routinely collected in healthcare. The study aimed to: identify the proportion of preschool children with mental health and somatic problems, the public sector services used by these children and whether they differ by type of problems, investigate whether other factors affect service use, and estimate the costs associated with these services. This study used cross-sectional data on a sample of 3175 children aged 3–5 from the “Children and Parents in Focus trial”. Data on service use, child health and demographics were obtained from primary caregivers. Child mental health was assessed by both primary caregivers and teachers. 8.9% of the sample reported mental health problems, and approximately 1% had comorbid somatic and mental health problems. Over 50% of the preschoolers used any service, with school assistant being the most frequently used. The average annual cost per child, regardless of health status, was US$921, with 75% of the costs accruing at school. The presence of both somatic and mental health problems predicted higher service use, in particular extra services used at school and at home (mean annual cost US$13826 and US$1583, respectively). Children with comorbid problems accounted for the highest mean costs. Mental health problems among preschool children were particularly high compared to studies from other countries. There is a need to strengthen school mental health services to engage in proactive early identification of children with mental health problems so that appropriate care is provided.Trial registration number: ISRCTN16513449. Registered 23 July 2013.
The influence of social relationships and school engagement on academic achievement in maltreated adolescents
Authors: Hershberger Mary A. , Jones Martin H. 
Published: June 2018

ABSTRACTAdolescents who have experienced maltreatment face many developmental and educational challenges compared with their non‐maltreated peers. Research demonstrates the importance of social relationships in academic achievement among non‐maltreated youth, and suggests the influence of parent and peer relationships for academic success in maltreated youth as well, including the potential benefit of school engagement. Data for the study comes from the first wave of the second National Survey of Child and Adolescent Well‐Being (NSCAW II), a nationally‐representative sample of children involved in Child Protective Services in the United States. The study finds that maltreated adolescents' perceptions of relationship quality with both parents and peers significantly predict academic achievement. In addition, results demonstrate a mediating effect of school engagement between parent and peer variables and some academic achievement outcomes.