bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhancement of Catalytic Activity in Epoxide Hydration by Increasing the Concentration of Cobalt(III)/Salen in Porous Polymer Catalysts
Authors: Dai Zhifeng , Sun Qi , Chen Fang , Pan Shuxiang , Wang Liang , Meng Xiangju , Li Jixue , Xiao Feng‐Shou 
Published: January 2016

AbstractThe rational design of catalytic materials from the reaction characteristics is expected to be a useful strategy to create highly efficient catalysts. Herein, according to a well‐established reaction pathway of epoxide hydration catalyzed a dual‐molecular system of Co3+/salen in which a high concentration of active sites is favorable to enhance the activity, we provide an alternative way to prepare a highly efficient heterogeneous catalyst with a high concentration of Co3+/salen from the polymerization of vinyl‐functionalized salen monomers followed by the loading of Co3+ species (Co3+/POL‐salen). Co3+/POL‐salen has a hierarchical porosity and an extraordinary hydrothermal stability. Importantly, catalytic tests in epoxide hydration demonstrate that Co3+/POL‐salen affords excellent high activities, which are even better than those of the homogeneous version. This phenomenon is related to the very high concentration of Co3+/salen in the catalyst. In addition, this catalyst can be recycled readily because of its excellent hydrothermal stability.
Mercury Removal by Adsorption on Pectin Extracted from Sugar Beet Pulp: Optimization by Response Surface Methodology
Authors: Ma Xinfang , Li Deqiang , Wu Zhansheng , Zhang Haiyan , Chen Xiaoxuan , Liu Zhiyong 
Published: January 2016

AbstractConsidering the rich sugar beet resource in Xinjiang, China, the possibilities for Hg(II) removal by pectin extracted from sugar beet pulp and optimization of the extraction process using response surface methodology (RSM) were studied. The experiments were proposed by Box‐Behnken design (BBD) and a second‐order regression model was developed for regression analysis and analysis of variance. Optimized conditions in terms of temperature, concentration, and solid‐liquid ratio were determined. The effects of different parameters like pH, time, temperature, and initial Hg(II) concentration on adsorption capacity were investigated. The isotherm adsorption experiments were fitted with the Langmuir model which indicated monolayer adsorption.
How Many Water Molecules Does it Take to Dissociate HCl?
Authors: Vargas‐Caamal Alba , Cabellos Jose Luis , Ortiz‐Chi Filiberto , Rzepa Henry S. , Restrepo Albeiro , Merino Gabriel 
Published: January 2016

AbstractThe potential energy surfaces of the HCl(H2O)n (n is the number of water molecules) clusters are systematically explored using density functional theory and high‐level ab initio computations. On the basis of electronic energies, the number of water molecules needed for HCl dissociation is four as reported by some experimental groups. However, this number is five owing to the inclusion of entropic factors. Wiberg bond indices are calculated and analyzed, and the results provide a quadratic correlation and classification of clusters according to the nondissociated, partially dissociated, and fully dissociated character of the H−Cl bond. Our computations show that if temperature is not controlled during the experiment, the values obtained for the dipole moment (or for any measurable property) are susceptible to change, providing a different picture of the number of water molecules needed for HCl dissociation in a nanoscopic droplet.
Advances on the Determination of the Astatine Pourbaix Diagram: Predomination of AtO(OH)2− over At− in Basic Conditions
Authors: Sergentu Dumitru‐Claudiu , Teze David , Sabatié‐Gogova Andréa , Alliot Cyrille , Guo Ning , Bassal Fadel , Silva Isidro Da , Deniaud David , Maurice Rémi , Champion Julie , Galland Nicolas , Montavon Gilles 
Published: January 2016

AbstractIt is generally assumed that astatide (At−) is the predominant astatine species in basic aqueous media. This assumption is questioned in non‐complexing and non‐reductive aqueous solutions by means of high‐pressure anion‐exchange chromatography. Contrary to what is usually believed, astatide is found to be a minor species at pH=11. A different species, which also bears a single negative charge, becomes predominant when the pH is increased beyond 7. Using competition experiments, an equilibrium constant value of 10−6.9 has been determined for the formation of this species from AtO(OH) with the exchange of one proton. The identification of this species, AtO(OH)2−, is achieved through relativistic quantum mechanical calculations, which rule out the significant formation of the AtO2− species, while leading to a hydrolysis constant of AtO(OH) in excellent agreement with experiment when the AtO(OH)2− species is considered. Beyond the completion of the Pourbaix diagram of astatine, this new information is of interest for the development of 211At radiolabeling protocols.
Real‐Time Chemical Analysis of E‐Cigarette Aerosols By Means Of Secondary Electrospray Ionization Mass Spectrometry
Authors: García‐Gómez Diego , Gaisl Thomas , Barrios‐Collado César , Vidal‐de‐Miguel Guillermo , Kohler Malcolm , Zenobi Renato 
Published: January 2016

AbstractChemical analysis of aerosols collected from electronic cigarettes (ECs) has shown that these devices produce vapors that contain harmful and potentially harmful compounds. Conventional analytical methods used for the analysis of electronic cigarettes do not reflect the actual composition of the aerosols generated because they usually neglect the changes in the chemical composition that occur during the aerosol generation process and after collection. The aim of this work was to develop and apply a method for the real‐time analysis of electronic cigarette aerosols, based on the secondary electrospray ionization technique coupled to high‐resolution mass spectrometry, by mimicking the “vaping” process. Electronic cigarette aerosols were successfully analyzed and quantitative differences were found between the liquids and aerosols. Thanks to the high sensitivity shown by this method, more than 250 chemical substances were detected in the aerosols, some of them showing a high correlation with the operating power of the electronic cigarettes. The method also allows proper quantification of several chemical components such as alkaloids and flavor compounds.
Observation of Main‐Group Tricarbonyls [B(CO)3] and [C(CO)3]+ Featuring a Tilted One‐Electron Donor Carbonyl Ligand
Authors: Jian Jiwen , Jin Jiaye , Qu Hui , Lin Hailu , Chen Mohua , Wang Guanjun , Zhou Mingfei , Andrada Diego M. , Hermann Markus , Frenking Gernot 
Published: January 2016

AbstractA combined experimental and theoretical study on the main‐group tricarbonyls [B(CO)3] in solid noble‐gas matrices and [C(CO)3]+ in the gas phase is presented. The molecules are identified by comparing the experimental and theoretical IR spectra and the vibrational shifts of nuclear isotopes. Quantum chemical ab initio studies suggest that the two isoelectronic species possess a tilted η1(μ1‐CO)‐bonded carbonyl ligand, which serves as an unprecedented one‐electron donor ligand. Thus, the central atoms in both complexes still retain an 8‐electron configuration. A thorough analysis of the bonding situation gives quantitative information about the donor and acceptor properties of the different carbonyl ligands. The linearly bonded CO ligands are classical two‐electron donors that display classical σ‐donation and π‐back‐donation following the Dewar–Chatt–Duncanson model. The tilted CO ligand is a formal one‐electron donor that is bonded by σ‐donation and π‐back‐donation that involves the singly occupied orbital of the radical fragments [B(CO)2] and [C(CO)2]+.
Enantiomeric Separations of Pyriproxyfen and its Six Chiral Metabolites by High‐Performance Liquid Chromatography
Authors: Zhang Chuntao , Liu Hui , Liu Donghui , Wang Liying , Gao Jing , Zhou Zhiqiang , Wang Peng 
Published: January 2016

AbstractPyriproxyfen is a chiral insecticide, and over 10 metabolites have been identified in the environment. In this work the separations of the enantiomers of pyriproxyfen and its six chiral metabolites were studied by high‐performance liquid chromatography (HPLC). Both normal phase and reverse phase were applied using the chiral columns Chiralpak IA, Chiralpak IB, Chiralpak IC, Chiralcel OD, Chiralcel OD‐RH, Chiralpak AY‐H, Chiralpak AD‐H, Chiracel OJ‐H, (R,R)‐Whelk‐O 1, and Lux Cellulose‐3. The effects of the chromatographic parameters such as mobile phase composition and temperature on the separations were investigated and the enantiomers were identified with an optical rotation detector. The enantiomers of these targets could obtain complete separations (resolution factor Rs > 1.5) on Chiralpak IA, Chiralpak IB, Chiralcel OD, Chiralpak AY‐H, or Chiracel OJ‐H under normal conditions. Chiralcel OJ‐H showed the best chiral separation results with n‐hexane as mobile phase and isopropanol (IPA) as modifier. The simultaneous enantiomeric separation of pyriproxyfen and four chiral metabolites was achieved on Chiralcel OJ‐H under optimized condition: n‐hexane/isopropanol = 80/20, 15°C, flow rate of 0.8 ml/min, and UV detection at 230 nm. The enantiomers of pyriproxyfen and the metabolites A, C, and D obtained complete separations on Chiralpak IA, Chiralpak IC, and Lux Cellulose‐3 under reverse phase using acetonitrile/water as the mobile phase. The retention factors (k) and selectivity factors (α) decreased with increasing temperature, and the separations were better under low temperature in most cases. The work is of significance for the investigation of the environmental behaviors of pyriproxyfen on an enantiomeric level. Chirality 28:245–252, 2016. © 2016 Wiley Periodicals, Inc.
Chemical looping syngas from CO2 and H2O over manganese oxide minerals
Authors: Perreault Patrice , Patience Gregory S. 
Published: January 2016

AbstractRather than sequestering carbon dioxide from the exhaust of chemical looping combustion reactors, together with the water, it could be used as a source of syngas. For the first time, we split water to hydrogen and carbon dioxide to carbon monoxide with a manganese ore. Specific CO production is 10–100 times higher than Sr, Ce, and Fe doped perovskites and perovskites. At a contact time of 0.01 s and at temperatures ranging from 810–960 °C the maximum specific CO production was 5.5 . A combined kinetic‐axial dispersion hydrodynamic model accounts for 97 % of the variance in the data assuming the reaction rate is first‐order in and surface reduced sites and in equilibrium with the reverse reaction—a first‐order reaction in CO with surface oxidized sites. A second reaction accounts for the diffusion of surface oxygen to the bulk lattice. Hydrogen productivity peaked at 4.8 at 947 °C, which is twice as high as reported in previous studies on and in the hercynite cycle.
Micro‐syngas technology options for GtL
Authors: Trevisanut Cristian , Jazayeri Seyed M. , Bonkane Said , Neagoe Cristian , Mohamadalizadeh Ali , Boffito Daria C. , Bianchi Claudia L. , Pirola Carlo , Visconti Carlo Giorgio , Lietti Luca , Abatzoglou Nicolas , Frost Lyman , Lerou Jan , Green William , Patience Gregory S. 
Published: January 2016

AbstractNatural gas emissions contribute to climate change, and equally importantly, affect the health of populations near gas fields.[1] At night, the flares from the Bakken fields in North Dakota burn as bright as the lights in cities as large as Minneapolis. Rather than flaring (or worse, venting), this associated natural gas represents a multi‐billion dollar opportunity.[2] Pipelines and liquefying natural gas are cost prohibitive in many cases. Converting methane to fuels is an attractive alternative.We examined three options to convert natural gas to syngas ( and CO), which is the first step to producing fuels: Steam Methane Reforming (SMR), Auto‐Thermal Reforming (ATR), and Catalytic Partial Oxidation (CPOX). Based on a multi‐objective optimization analysis, C hydrocarbon yields are highest with CPOX as the first step followed by Fischer‐Tropsch synthesis (FT). A micro‐refinery with the CPOX‐FT process treating (100 ) natural gas, produces 1300 (8.2 ) of C hydrocarbons. Maximum yields for the SMR‐FT and ATR‐FT processes are 938 and 1100 (5.9 , 7.0 ) of C, respectively. Large‐scale POX and ATR processes produce 1600 L per 2800 kL (10 bbl per 100 MCF) of natural gas.
Anxiety, pain, and nausea during the treatment of standard‐risk childhood acute lymphoblastic leukemia: A prospective, longitudinal study from the Children's Oncology Group
Authors: Dupuis L. Lee , Lu Xiaomin , Mitchell Hannah‐Rose , Sung Lillian , Devidas Meenakshi , Mattano Leonard A. , Carroll William L. , Winick Naomi , Hunger Stephen P. , Maloney Kelly W. , Kadan‐Lottick Nina S. 
Published: January 2016

BACKGROUNDThis prospective study describes the procedure‐related anxiety, treatment‐related anxiety, pain, and nausea experienced by children with standard‐risk acute lymphoblastic leukemia (ALL) during the first year of treatment.METHODSThis study was undertaken at 31 Children's Oncology Group (COG) sites. Eligible children who were 2 to 9.99 years old were enrolled in a COG trial for patients with newly diagnosed standard‐risk ALL from 2005 to 2009. Parents completed a demographic survey at the baseline and the Pediatric Quality of Life Inventory 3.0 Cancer Module (proxy version) and the General Functioning Scale of the Family Assessment Device 1, 6, and 12 months after the diagnosis. The association between patient‐related (age, sex, ethnicity, and treatment), parent‐related (marital status and education), and family‐related factors (functioning, income, and size) and symptom scores was evaluated.RESULTSThe mean scores for procedure‐related anxiety, treatment‐related anxiety, and pain improved during the first year of treatment (P < .0389). The mean nausea score was poorer 6 months after the diagnosis in comparison with the other assessments (P = .0085). A younger age at diagnosis was associated with significantly worse procedure‐related anxiety (P = .004). An older age (P = .0002) and assignment to the intensified consolidation study arm (P = .02) were associated with significantly worse nausea.CONCLUSIONSChildren with ALL experienced decreasing treatment‐related anxiety, procedure‐related anxiety, and pain during the first year of treatment. In comparison with scores at 1 and 12 months, nausea was worse 6 months after the diagnosis. Minimization of procedure‐related anxiety in younger children and improved nausea control in older children and those receiving more intensified treatment should be prioritized. Cancer 2016;122:1116–1125. © 2016 American Cancer Society
Cancer care cost trends in the United States: 1998 to 2012
Authors: Lee James A. , Roehrig Charles S. , Butto Erin Duggan 
Published: January 2016

BACKGROUNDThe authors examine trends in spending on cancer from 1998 through 2012, including cancer care costs, prevalence, and cases by payer, and discuss the results within the context of a prior analysis and recent health policy and programmatic changes.METHODSCondition‐specific distribution of expenditures from the Medical Expenditure Panel Survey, supplemented with results from the National Nursing Home Survey and other data sources, was used as the basis for allocating the Personal Health Care components of the National Health Expenditure Accounts among conditions.RESULTSCancer care expenditures grew at an annualized rate of 2.9% from 1998 to 2012. The share of expenditures for hospital‐based care declined to a low of 48% during 2007 through 2009. Professional and clinical services' shares declined substantially between 2007 to 2009 and 2010 to 2012 when the hospital share increased. Treated prevalence decreased for all payers between the first and last study periods with the exception of private payers (11.2% increase). Out‐of‐pocket expenditures declined to 4.7%, whereas Medicare's share increased slightly. Medication expenditures increased, notably within retail and mail order settings.CONCLUSIONSThe previous rapid growth of cancer prevalence and expenditures has now slowed, most remarkably since the 2007 recession. Out‐of‐pocket expenses for cancer treatment continue to decline, most recently reaching the lowest point in 25 years. In addition, the early effects of Affordable Care Act expansion can be observed in the decline of treated prevalence in the Medicaid population as the demographics of Medicaid enrollees change. Cancer 2016;122:1078–1084. © 2016 American Cancer Society
Electrochemistry of Layered Graphitic Carbon Nitride Synthesised from Various Precursors: Searching for Catalytic Effects
Authors: Yew Ying Teng , Lim Chee Shan , Eng Alex Yong Sheng , Oh Junghoon , Park Sungjin , Pumera Martin 
Published: January 2016

AbstractGraphitic carbon nitride (g‐C3N4), synthesised by pyrolysis of different precursors (dicyandiamide, melamine and urea) under varying reaction conditions (air and nitrogen gas) is subjected to electrochemical studies for the elucidation of the inherent catalytic efficiency of the pristine material. Contrary to popular belief, pristine g‐C3N4 shows negligible, if any, enhancement in its electrochemical behaviour in this comprehensive study. Voltammetric analysis reveals g‐C3N4 to display similar catalytic efficiency to the unmodified glassy carbon electrode surface on which the bulk material was deposited. This highlights the non‐catalytic nature of the pristine material and challenges the feasibility of using g‐C3N4 as a heterogeneous catalyst to deliver numerous promised applications.
Hole‐Transporting Materials Based on Twisted Bimesitylenes for Stable Perovskite Solar Cells with High Efficiency
Authors: Lin Yan‐Duo , Ke Bo‐Yu , Lee Kun‐Mu , Chang Sheng Hsiung , Wang Kai‐Hung , Huang Shih‐Han , Wu Chun‐Guey , Chou Po‐Ting , Jhulki Samik , Moorthy Jarugu Narasimha , Chang Yuan Jay , Liau Kang‐Ling , Chung Hsin‐Cheng , Liu Ching‐Yang , Sun Shih‐Sheng , Chow Tahsin J. 
Published: January 2016

AbstractA new class of hole‐transport materials (HTMs) based on the bimesitylene core designed for mesoporous perovskite solar cells is introduced. Devices fabricated using two of these derivatives yield higher open‐circuit voltage values than the commonly used spiro‐OMeTAD. Power conversion efficiency (PCE) values of up to 12.11 % are obtained in perovskite‐based devices using these new HTMs. The stability of the device made using the highest performing HTM (P1) is improved compared with spiro‐OMeTAD as evidenced through long‐term stability tests over 1000 h.
High‐Precision Sensorless Force Control by Mode Switching Controller for Positioning Devices with Contact Operation
Authors: MAEBASHI WATARU , ITO KAZUAKI , MATSUO KOHEI , IWASAKI MAKOTO 
Published: January 2016

SUMMARYThis paper presents an approach to high‐precision sensorless force control for positioning devices that engage in a contact operation. The sensorless force control is designed with a sliding mode controller and contact model that provide the required control specifications to compensate for the nonlinear spring characteristics of the contact mechanism. The effectiveness of the proposed control approach was verified through numerical simulations and experiments using a prototype.
Iron Loss Characteristics of Electrical Steel Sheet under Inverter Excitation by Power Semiconductor with Extremely Low On‐Voltage Property
Authors: ODAWARA SHUNYA , KAYAMORI DAISUKE , FUJISAKI KEISUKE 
Published: January 2016

SUMMARYIn this study, it is demonstrated that the iron loss from the SiC‐MOSFET, which represents a new power semiconductor with an extremely low on‐voltage for electric machine drives, is almost the same as that from an Si‐IGBT, which is a conventional power semiconductor. In order to evaluate the iron loss characteristics when an SiC device is used, two single‐phase pulse width modulation inverters were built and used for the excitation of a ring made up of electrical steel sheet. One of the inverter employed an SiC‐MOSFET, and the other inverter employed an Si‐IGBT. The iron losses for the two inverters are compared.
Estimation Prediction Interval of Solar Irradiance Based on Just‐in‐Time Modeling for Photovoltaic Output Prediction
Authors: YAMAZAKI TOMOHIDE , HOMMA HAYATO , WAKAO SHINJI , FUJIMOTO YU , HAYASHI YASUHIRO 
Published: January 2016

SUMMARYPhotovoltaic (PV) systems have recently attracted considerable attention in the context of environmental problems, antinuclear power movements, and energy problems. Therefore, the large‐scale introduction of PV systems is expected in the near future. But the connection of many PV systems to the power system leads to problems. For example, the system voltage often drifts from the norm when reverse power flows increase. Accordingly, optimal system operation is required in order to make maximum use of solar energy to the maximum by installing energy buffers such as storage batteries. In particular, in forecast information, knowledge of the reliability as well as the predicted solar irradiance is essential for effective operation. In this paper, we propose a way of estimating the prediction interval of solar irradiance as an index of reliability by using just‐in‐time modeling. We consider the accuracy of the prediction interval under many conditions and derive a high‐precision estimation method. In addition, we also discuss about the future subjects of study.
Three‐Phase to Single‐Phase Matrix Converter for Improvement of Three‐Phase Voltage Unbalance in Distribution System
Authors: MIZUTANI RYOTA , KOIZUMI HIROTAKA , HIROSE KENTARO , ISHIBASHI KAZUNARI 
Published: January 2016

SUMMARYFrom the global environmental viewpoint, distributed power systems using renewable energy source, such as solar power, wind power, and water power, are attracting much attention. Photovoltaic (PV) systems using solar power have few resource constraints and can be installed easily on the roofs of houses. Therefore, PV systems have been and will be introduced widely. However, when many PV systems are installed in consumers, differences in installed PV capacity may cause load unbalances. In such a case, the difference in the line currents flowing along medium‐ and high‐voltage lines can be increased and three‐phase voltage unbalances may appear due to the line impedance. In this paper, a distribution transformer using a three‐phase to single‐phase matrix converter with an ac inductor is proposed to suppress three‐phase voltage unbalances. The ac inductor is used for compensation of single‐phase power pulsations under any load conditions and in either direction of power flow. The proposed method was verified by a simulation with MATLAB/Simulink. In this simulation, resistive loads and reactive loads were assumed as the loads in the low‐voltage line. Reverse power flow from PV systems is represented by a current source with a power factor of 1.0. The control strategy and simulation results are presented in this paper.