bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tris(pentafluoroethyl)stannane: Tin Hydride Chemistry with an Electron‐Deficient Stannane
Authors: Wiesemann Markus , Niemann Mark , Klösener Johannes , Neumann Beate , Stammler Hans‐Georg , Hoge Berthold 
Published: December 2017

AbstractA versatile two‐step synthesis of tris(pentafluoroethyl)stannane, HSn(C2F5)3, is presented. Electron‐withdrawing C2F5 groups significantly influence the polarity of the tin–hydrogen bond, which allows facile deprotonation of the compound, even in water. The utility of this electron‐deficient stannane was illustrated in hydrostannylations of alkenes and alkynes, as well as in dehalogenation reactions. The remarkably high reactivity of HSn(C2F5)3 is demonstrated in fast hydrostannylations, even in the absence of activators, whereby the regioselectivity of this process turns out to be solvent dependent. It is of great advantage that in dehalogenation reactions volatile halogenotris(pentafluoroethyl)stannanes, XSn(C2F5)3 (X=I, Br), are formed that allow facile separation of the tin‐containing byproducts from the reaction mixtures.
Activities of 11‐Azaartemisinin andN‐Sulfonyl Derivatives againstNeospora caninumand Comparative Cytotoxicities
Authors: Harmse Rozanne , Wong Ho Ning , Smit Frans J. , Müller Joachim , Hemphill Andrew , N'Da David D. , Haynes Richard K. 
Published: December 2017

AbstractNeosporosis caused by the apicomplexan parasiteNeospora caninumis an economically important disease that induces abortion in dairy and beef cattle. There are no vaccines or drugs available on the market for control or treatment of the disease in bovines. The peroxide artemisinin and its derivatives used clinically for treatment of malaria are active againstN. caninumand other apicomplexan parasites. We have now evaluated the activities of the readily accessible and chemically robust 11‐azaartemisinin5and selectedN‐sulfonyl derivatives prepared as described in the accompanying paper againstN. caninumtachyzoites grown in infected human foreskin fibroblasts. Azaartemisinin elicited an IC50value of 150 nm, and the 2′,5′‐dichloro‐3′‐thienylsulfonyl‐11‐azaartemisinin17was found to be the most active, with an IC50value of 40 nm. Comparison with normal human fetal lung fibroblasts HFLF WI‐38 revealed relatively benign cytotoxicity. The compounds were also screened in vitro against TK‐10 (renal), UACC‐62 (melanoma) and MCF‐7 (breast) cancer cell lines; overall, in line with activities against HFLF cells, most compounds in the series were found to be inactive.
Electronic Properties of h‐BCN–Blue Phosphorene van der Waals Heterostructures
Authors: Kaewmaraya Thanayut , Srepusharawoot Pornjuk , Hussian Tanveer , Amornkitbamrung Vittaya 
Published: December 2017

AbstractVan der Waals heterostructures, a new class of materials made of a vertically selective assembly of various 2D monolayers held together by van der Waals forces, have attracted a great deal of attention due to their promise to deliver novel electronic and optoelectronic properties that are not achievable by using individual 2D crystals. Using density functional theory (DFT), it is revealed that van der Waals heterostructures composed of monolayers of hexagonal boron nitride (h‐BN) and the latest P allotrope blue phosphorus (blue phosphorene, BlueP) forms a straddling type I band offset for which the band edges exclusively belong to BlueP. This feature enables h‐BN to act as a protective coating material to resolve the air instability of BlueP. Furthermore, substitutional doping of C into h‐BN (h‐BCN) at a suitable concentration induces h‐BCN–BlueP into staggered type II band offset. The type II band alignment triggered by the intensified built‐in electric field across the sheets implies improved carrier mobility and the suppressed recombination of photogenerated hole pairs. These major benefits can pave the way for the potential functionality of h‐BCN–BlueP to be exploited for efficient photovoltaic devices.
Further Studies on How the Nature of Zeolite Cavities That Are Bounded by Small Pores Influences the Conversion of Methanol to Light Olefins
Authors: Kang Jong Hun , Walter Raimund , Xie Dan , Davis Tracy , Chen Cong‐Yan , Davis Mark E. , Zones Stacey I. 
Published: December 2017

AbstractA series of small‐pore zeolites are synthesized and investigated as catalysts for the methanol‐to‐olefins (MTO) reaction. Small‐pore zeolites SSZ‐13, SSZ‐16, SSZ‐27, SSZ‐28, SSZ‐52, SSZ‐98, SSZ‐99, SSZ‐104, SSZ‐105 and an ITQ‐3‐type material are synthesized, and the results from their use as catalytic materials in the MTO reaction compared to those obtained from SAPO‐34. The production of propane that tends to correlate with catalytic material lifetime (higher initial propane yields lead to shorter lifetimes) declines with increasing Si/Al (as has been observed previously for SSZ‐13), and a larger cage dimension leads to higher propane yields at a fixed Si/Al. Data from these materials and others reported previously, for example, SSZ‐39 and Rho, that were tested at the same reaction conditions, revealed four different patterns of light olefin selectivities: 1) ethylene greater than propylene with low butene, for example, SSZ‐17, SSZ‐98, SSZ‐105, 2) ethylene equal to propylene and low butene, for example, SAPO‐34, SSZ‐13, SSZ‐16, SSZ‐27, SSZ‐52, SSZ‐99, SSZ‐104, 3) propylene greater than ethylene with butene similar to ethylene, for example, SSZ‐28, SSZ‐39, and 4) ethylene equal to propylene equal to butene, for example, Rho. No clear relationships between zeolite cage architecture and light olefin selectivity emerged from this investigation, although several trends are presented as suggestions for further study.
Controllable Synthesis and Growth Mechanism of Ceria Nanocubes by Template‐Free Hydrothermal Method
Authors: Zhang Hepeng , Yang Bo , Li Huan , Wu Chen , Wang Wenbin , Zhang Baoliang , Zhang Qiuyu , Zhang Chongyin 
Published: December 2017

AbstractDifferent crystal planes of CeO2 have a different number of broken bonds, surface energy and catalytic activities, so preparing the CeO2 with different exposed planes has attracted extensive attention. In recent years, the preparation of CeO2 nanocubes with {100} exposed plane has been a real hotspot of research because of its good catalytic performance. Based on the research about the alkali concentration, reaction temperature and reaction time, the formation mechanism of CeO2 nanocubes was explored. It is believed that the dissolution‐recrystallization process is accelerated in the condition of strong base, high temperature and high pressure. In other word, the Ostwald ripening process is strengthened, which is the decisive factor for the formation of CeO2 nanocubes.
Tracking Ionic Rearrangements and Interpreting Dynamic Volumetric Changes in Two‐Dimensional Metal Carbide Supercapacitors: A Molecular Dynamics Simulation Study
Authors: Xu Kui , Lin Zifeng , Merlet Céline , Taberna Pierre‐Louis , Miao Ling , Jiang Jianjun , Simon Patrice 
Published: December 2017

AbstractWe present a molecular dynamics simulation study achieved on two‐dimensional (2D) Ti3C2Tx MXenes in the ionic liquid 1‐ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM]+[TFSI]−) electrolyte. Our simulations reproduce the different patterns of volumetric change observed experimentally for both the negative and positive electrodes. The analysis of ionic fluxes and structure rearrangements in the 2D material provide an atomic scale insight into the charge and discharge processes in the layer pore and confirm the existence of two different charge‐storage mechanisms at the negative and positive electrodes. The ionic number variation and the structure rearrangement contribute to the dynamic volumetric changes of both electrodes: negative electrode expansion and positive electrode contraction.
Mild Upgrading of Bio‐Crude Pyrolysis Oil: A Concept Based on Bio‐Based Alcohols with Selective Water Adsorption
Authors: Kumar Pazhavelikkakath Purushothaman Rajeesh , Buntara Teddy , Zhang Zheng , Vehoff Ilse J. , Boyadjian Cassia , Falco Lorena , Seshan Kulathuiyer , Gómez Natalia , Heeres Hero J. , Melián‐Cabrera Ignacio 
Published: December 2017

AbstractBiocrude pyrolysis oil is obtained by a process called fast‐pyrolysis, in which almost any organic‐based feedstock is thermally processed at moderate temperatures, in the range of 400–600 °C, in the absence of oxygen at short residence times. After condensing the vapors in a cooling tray, a dark‐brown bioliquid is obtained. The quality of the thus obtained fast pyrolysis oil has some barriers for its direct use as transportation fuel. Low caloric value, high viscosity, and corrosion are the major challenges for its implementation in conventional engines. There have been sustained efforts to improve the quality of the oil. In this Communication we are reporting a concept on improving the acidic properties by means of a combined catalysis and adsorption approach. We found that fast pyrolysis oil can be upgraded through alcoholysis using n‐butanol and tetrahydrofurfuryl alcohol, which are biomass‐derived bulk chemicals. The reaction is acid catalyzed whereas water is continuously separated from the condensate mixture through molecular sieve adsorption. Under optimal conditions, the ultimate acidity and water content of the upgraded product are negligible.
Effect of simulated combustion atmospheres on oxidation and microstructure evolution of aluminum alloy 5052
Authors: Xie Dongbai , Wang Wen , Lv Shilei , Shan Guo 
Published: December 2017

SummaryAmong the common materials, metals can be hardly destroyed by flame or the heat emanating from a normal fire. Consequently, investigation on the thermal patterns produced on metallic objects after fire exposure can provide important physical evidence for fire cause/origin determination. Aluminum alloy is widely used in our daily life and the industry; hence, it can be easily found on a domestic or industrial fire scene. In this paper, the aluminum alloy 5052 was exposed in the simulated combustion gases with and without kerosene in the range of 300 to 500°C. Mass change, morphologies, and microstructures of each sample were carefully characterized by thermogravimetric analysis, morphologic observation, and electron microscopy observation with energy‐dispersive spectroscopy analysis after exposure. As expected, the microstructure of alloy changed during high temperature exposure. At the same time, an oxide scale formed and was thickened on the surface of alloy. The results reveal that the temperature can significantly affect the growth of oxide scale and the metallurgical microstructure of alloy. It is noteworthy that the presence of kerosene in the combustion gas accelerated oxidation rate and produced oxide scales different from those formed in air. These feature evolutions in surface oxide are expected to offer complementary insight on determining the fire characteristics, such as the exposure temperature, period and whether liquid accelerant is involved.
Fire‐retarding properties of nanowollastonite in particleboard
Authors: Esmailpour Ayoub , Taghiyari Hamid R. , Nouri Pezhman , Jahangiri Asghar 
Published: December 2017

SummaryEffects of wollastonite nanofibers on fire‐retarding properties of particleboard were studied here. Nanowollastonite (NW) was applied at 5%, 10%, 15%, and 20% based on the dry weight of wood particles. The size range of wollastonite nanofibers was 30 to 110 nm. Two application methods of NW were used: surface application (SA) in which NW was mixed with a water‐based paint and sprayed on the specimens, and internal application (IA) in which NW was mixed with the urea‐formaldehyde resin. Density was kept constant at 0.68 g/cm3 for all treatments. Specimens of 150 × 130 × 9 mm were prepared, and fire‐retarding properties were measured using 2 apparatuses: slide fire test apparatus and fixed fire test apparatus. The obtained results indicated that most fire‐retarding properties were improved with the increase in NW content up to 15% when applied internally. More than this amount resulted in decreasing of properties that was partly due to the less wood‐chips content and partly due to the absorption of resin by the NW fibers. Surface application showed higher improving effects on the properties. It can be concluded that SA of NW is more effective in improving fire‐retarding properties of particleboard; furthermore, 10% of NW is recommended as an optimum level of consumption.
Oxidative stability of canola oil by Biarum bovei bioactive components during storage at ambient temperature
Authors: Farahmandfar Reza , Ramezanizadeh Mohammad Hossein 
Published: December 2017

AbstractIn this study, antioxidative activities of aqueous extract of Biarum bovei (BBE) in stabilizing of canola oil during storage at 20°C was evaluated. For this purpose, the total phenolic (TP), flavonoids (TFC), and tocopherol content (TTC) of the extract were determined and β‐carotene bleaching system was used to assess the antioxidant efficacy of BBE. The amount of TP, TFC, and TTC in BBE indicated high antioxidant activity. So, different concentrations (0, 200, 800, and 1400 ppm) of BBE and butylatedhydroxyanisole (BHA; 100 ppm), were added to canola oil for 60 days at 20°C. Peroxide value (PV), carbonyl value (CV), Total polar compounds (TPC), acid value (AV), iodine values (IV), and conjugated dienes (CD) were employed to evaluate the BBE effect on canola oil stabilizing. Results indicated that 1,400 ppm of BBE exhibited stronger antioxidant activity in canola oil than BHA.
Problems of dual vulnerability in nutrition: A qualitative study of older persons caring for under 5‐year‐olds in post‐disaster Haiti
Authors: Raybould Stephanie , Ward Thomas , Burnett Renée , Manikam Logan , Tibe Mackentoch , Munslow Barry 
Published: December 2017

SummarySituationMalnutrition plays a significant role in under‐five mortality rates following disasters. Older people play an important role in childcare in non‐Western societies, which often increases in displacement contexts. Until now, policy, in general, and nutrition programmes, in particular, have focused on the mother‐child dyad.AimTo gather information on possible barriers to older carers accessing nutritional services for the children they care for and explore ways to overcome these obstacles.MethodA qualitative approach was taken to explore the experiences of the carers themselves. Focus group discussions provided data, which were analysed using grounded theory.ResultsData collected showed older people have similar needs to other caregivers in emergency settings, needs that are often amplified by age. Moreover, many barriers to accessing services were elicited, including targeting and advertising of nutritional programmes, alongside physical and psychosocial barriers to assessing existing support. Participants generated potential solutions to each identified barrier.ConclusionAs older people in Haiti were often the sole carers of under‐fives, there is a need to recognise their importance in this role and support them within. More generally, in any emergency setting, organisations need take into account all stakeholders in child nutrition when planning and implementing programmes.
Higher serotonin transporter availability in early‐onset obsessive–compulsive disorder patients undergoing escitalopram treatment: A [11C]DASB PET study
Authors: Lee Junhee , Kim Bo‐Hyung , Kim Euitae , Howes Oliver D. , Cho Kang Ik Kevin , Yoon Youngwoo Bryan , Kwon Jun Soo 
Published: December 2017

AbstractObjectiveEarly‐onset obsessive–compulsive disorder (EOCD) and late‐onset obsessive–compulsive disorder (LOCD) are distinct subtypes of obsessive–compulsive disorder (OCD). OCD patients are treated with serotonin reuptake inhibitors, but the difference in serotonin transporter (SERT) availability between medicated EOCD and LOCD is unexplored yet.MethodsSix EOCD and 6 LOCD patients were enrolled. They underwent serial [11C]DASB positron emission tomography scans during maintenance therapy with escitalopram, and their plasma concentration of escitalopram was measured simultaneously with the scan. Then, the drug‐free binding potential of SERT was calculated by pharmacokinetic–pharmacodynamic modelling.ResultsIn comparison with LOCD patients, SERT availability was significantly higher in the putamen of EOCD patients (U = 4, p = .026), but not in the caudate nucleus (U = 14, p = .589), thalamus (U = 16, p = .818), and dorsal raphe nucleus (U = 7, p = .093). Binding potential of putamen showed a negative correlation (r = −.580, p = .048) with age of onset of the disease, but not with the Yale–Brown Obsessive Compulsive Scale scores.ConclusionsThese findings indicate that the earlier the age of onset of OCD, the less serotonergic pathology there is and that this difference remains even after long‐term serotonin reuptake inhibitor treatment. Clinically, it might suggest that nonserotonergic treatments would be a better option for EOCD patients.
Technical Efficiency of Rainfed and Irrigated Rice Production in Tanzania
Authors: Mkanthama Joseph , Makombe Godswill , Kihoro John , Ateka Elija M. , Kanjere Matshidiso 
Published: December 2017

AbstractTanzania produces rice from two major ecologies, namely irrigated and rainfed lowland. Currently most of the rice is produced from the rainfed lowland but the country's National Rice Development Strategy (NRDS) hopes to reverse this trend. The NRDS aims to increase the rice production area for irrigated lowland ecology from 200 000 ha in 2008 to 390 000 ha by 2018, with productivity increasing from 2.13 t ha−1 in 2008 to 3.5 t ha−1 in 2018. This study evaluated the performance of irrigated and rainfed lowland rice production using technical efficiency. This paper estimates the technical efficiency of rice production in Tanzania for the irrigated and rainfed lowland ecologies. Data were collected from an irrigated site in Bagamoyo and a lowland rainfed site, Dakawa in the Morogoro area. The study found that the average technical efficiency of the irrigating farmers is 96% compared to an average 39% for the rainfed lowland system. For the irrigated system, there are no farmers with technical efficiency less than 80%. This high technical efficiency indicates that in order to achieve the rice production targets aspired to, the opportunity for increasing production therefore lies in changing the production technology. Copyright © 2017 John Wiley & Sons, Ltd.
Assessment of Deficit Irrigation Responses of Moroccan Alfalfa (Medicago Sativa L.) Landraces Grown Under Field Conditions
Authors: Mouradi Mohammed , Bouizgaren Abdelaziz , Farissi Mohamed , Ghoulam Cherki 
Published: December 2017

AbstractThe aim of this study was to assess the responses of five alfalfa genotypes to summer drought under field conditions. Landraces from oases, Adis1 and Tata2, others, Demnate208 and Demnate206, from the Moroccan Atlas Mountains and Siriver, were grown at the experimental station of INRA. The plants were subjected to 100% ETc (crop potential evapotranspiration) as control, 75% as moderate and 50% as severe drought. Growth, water parameters and physiological responses were assessed. Results showed that stress significantly reduced plant dry biomass, height, stomatal conductance and increased water productivity (WP) in all of tested cultivars with variation between them. The highest biomass reductions were registered under 50% ETc and were more pronounced in Demnate208 (exceeded 50%), than in Adis1 (did not reach 37%). Therefore, we qualified the latter as more tolerant and the former as less tolerant. Adis1 presented high WP (0.11 kg m−3). It accumulated the highest proline, sugars and K+ under stress. Siriver presented intermediate behaviour. For all of the assessed parameters, we noted high consistency between growth and water parameters and proline, sugars and K+ accumulations, particularly in Adis1. Thus, we suggested that these compatible solutes could be involved in the alfalfa drought tolerance mechanism. Copyright © 2017 John Wiley & Sons, Ltd.
The stationarity of two statistical downscaling methods for precipitation under different choices of cross‐validation periods
Authors: Wang Yaoping , Sivandran Gajan , Bielicki Jeffrey M. 
Published: December 2017

ABSTRACTStatistical downscaling methods require the stationarity assumption, that is, the statistical relationship between the grid‐scale input and the observed precipitation does not change between present‐day and climate change conditions. We implemented a skill score to test the stationarity assumption in two simple and popular statistical downscaling methods, quantile‐mapping and the generalized linear model method Rglimclim, in downscaling precipitation in the eastern United States, and examined the sensitivity of the results of the stationarity test to different ways to construct cross‐validation periods that differ in climate conditions. The Rglimclim method passed the stationarity test at slightly more stations than quantile‐mapping and was less impaired by increase in the resolution of input data. But neither method can be reliably applied to downscale the whole marginal distribution or time series of precipitation at the 54 stations in the study region, and only passed the stationarity test at a few stations on the annual extreme precipitation. We also found that the number of identified non‐stationary stations was sensitive to which criterion (chronology, precipitation, temperature, large‐scale circulation indices) was used to construct the cross‐validation periods, and whether one or several criteria for cross‐validation periods were used. These results raise caution against using the two statistical downscaling methods that we examined in climate change impact studies without testing their stationarity assumption, and also point to the need for more research into how to choose cross‐validation periods and stationarity metrics in order to maximize their relevance to the reliability of statistical downscaling methods under future climate change.
Validation of SERS enhancement factor measurements
Authors: Pilot R. , Bozio R. 
Published: December 2017

AbstractThe huge signal enhancement that motivates the rapid spreading of surface‐enhanced Raman scattering (SERS) in a wide range of applications is commonly quantified by measuring the enhancement factor (EF). Concerning this important parameter, in this paper, we tackle 2 points: (a) We validate the use of a Macro Raman configuration with line focus to measure the EFs, against the more common Micro Raman one. The validation is carried out by comparing the EFs measured in the 2 configurations with the well‐established methodology, on the same set of commercial substrates. Macro Raman with line focus can be advantageous over the Micro Raman because it can provide a higher signal‐to‐noise ratio at equal laser intensity impinging on the sample (useful in sensing or analytical applications). (b) It is a common practice for practitioners validating an experiment by measuring a commercial compound, acting as a “standard,” whose properties have been already determined in the literature: To our knowledge, an equivalent “standard” does not exist for EF measurements, probably due to the reproducibility and aging issues that prevent them from being identically reproduced in different laboratories. Because the EF is the cross‐section ratio of a test molecule under SERS and normal Raman conditions, if one replaces the SERS substrate and the reference liquid with 2 commercial materials in the EF measurement procedure, this leads to the determination of another cross‐section ratio: We propose then to use the cross‐section ratio of suitable commercial materials for the validation of the instrumental procedure used to measure EFs.