bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel‐doped zinc oxide sorbents for low temperature regenerable desulfurization applications
Authors: Yang Hongyun , Tatarchuk Bruce 
Published: February 2010

AbstractEight metal oxide sorbents including transition metal doped ZnO/SiO2 sorbents and ZnO/SiO2 were prepared by incipient wetness impregnation for regenerable desulfurization applications at low temperatures (i.e. room temperature). Among them, copper‐doped sorbent (Cu‐ZnO/SiO2) demonstrated the highest saturation sulfur capacity of 0.213 g sulfur/g ZnO (54% of the theoretical capacity), which is twice that of ZnO/SiO2 sorbent. Compared with ZnO/SiO2, Cu‐ZnO/SiO2 demonstrated superior desulfurization performance in a wide temperature range of 20–400°C. Due to the use of porous SiO2 support, Cu‐ZnO/SiO2 is highly regenerable. It can be easily regenerated in air at low temperatures, ca. 300–550°C, which are much lower than the typical regeneration temperatures of commercial ZnO sorbents. Cu‐ZnO/SiO2 maintained its sulfur capacity during 10 cycles of regeneration/sulfidation. © 2010 American Institute of Chemical Engineers AIChE J, 2010
Enantiospecific Stereodivergent Synthesis of trans‐ and cis‐N(2),3‐Dimethyl‐4‐phenyl‐1,2,3,4‐tetrahydroisoquinolines
Authors: Coote Steven J. , Davies Stephen G. , Fletcher Ai M. , Roberts Paul M. , Thomson James E. 
Published: February 2010

AbstractThe acid‐promoted cyclizations of a range of N‐benzylethanolamines (derived from pseudoephedrine or ephedrine) give the corresponding trans‐N(2),3‐dimethyl‐4‐phenyl‐1,2,3,4‐tetrahydroisoquinolines with high levels of diastereoselectivity and in good yields of isolated product. The cyclizations of the corresponding chromium tricarbonyl complexes are rendered completely stereoselective. Acid‐promoted cyclization of N‐(3′,4′‐dimethoxybenzyl)ephedrine and its chromium tricarbonyl complex occur with complementary diastereoselectivities to give trans‐ and cis‐N(2),3‐dimethyl‐4‐phenyl‐6,7‐dimethoxy‐1,2,3,4‐tetrahydro‐isoquinoline, respectively, in >99:1 d.r. The latter is consistent with a “double inversion” mechanism, which involves neighboring group participation by the chromium tricarbonyl moiety followed by rearomatization to give the corresponding cis‐tetrahydroisoquinoline with overall retention of configuration.
Electrografted Poly(N‐mercaptoethyl acrylamide) and Au Nanoparticles‐Based Organic/Inorganic Film: A Platform for the High‐Performance Electrochemical Biosensors
Authors: Li Limiao , Xu Shoujiang , Du Zhifeng , Gao Yanfang , Li Jinghong , Wang Taihong 
Published: February 2010

AbstractIn this study, we describe the use of the combination of eletrografting poly(N‐mercaptoethyl acrylamide) and Au nanoparticles in the construction of high‐performance biosensors. The poly(N‐mercaptoethyl acrylamide) was electrografted onto the glassy carbon electrode surface, which provided a strongly adhering primer film for the stable attachment of Au nanoparticles and horseradish peroxidase (HRP) enzymes. The performances of the biosensors based on the HRP immobilized in the Au/poly(N‐mercaptoethyl acrylamide) composite film were investigated. A couple of redox peaks were obtained, indicating that the Au nanoparticles could facilitate the direct‐electron transfer between HRP and the underlying electrode. The biosensor showed an excellent electrocatalytic activity toward the reduction of hydrogen oxide and long‐term stability, owing to the stable electrografted film and biocompatible Au nanoparticles. Our results demonstrate that the combination of electrografting and Au nanoparticles provides a promising platform for the immobilization of biomolecules and analysis of redox enzymes for their sensing applications.
Accreting white dwarfs as supersoft X‐ray sources
Authors: Kato M. 
Published: February 2010

AbstractI review various phenomena associated with mass‐accreting white dwarfs (WDs) in the view of supersoft X‐ray sources. When the mass‐accretion rate is low (Ṁacc < a few × 10–7 M⊙yr–1), hydrogen nuclear burning is unstable and nova outbursts occur. A nova is a transient supersoft X‐ray source (SSS) in its later phase which timescale depends strongly on the WD mass. The X‐ray turn on/off time is a good indicator of the WD mass. At an intermediate mass‐accretion rate an accreting WD becomes a persistent SSS with steady hydrogen burning. For a higher mass‐accretion rate, the WD undergoes “accretion wind evolution” in which the WD accretes matter from the equatorial plane and loses mass by optically thick winds from the other directions. Two SSS, namely RX J0513‐6951 and V Sge, are corresponding objects to this accretion wind evolution. We can specify mass increasing WDs from light‐curve analysis based on the optically thick wind theory using multiwavelength observational data including optical, IR, and supersoft X‐rays. Mass estimates of individual objects give important information for the binary evolution scenario of type Ia supernovae (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Non‐LTE model atmospheres for supersoft X‐ray sources
Authors: Rauch T. , Werner K. 
Published: February 2010

AbstractIn the last decade, X‐ray observations of hot stellar objects became available with unprecedented resolution and S/N ratio. For an adequate interpretation, fully metal‐line blanketed Non‐LTE model‐atmospheres are necessary. The Tübingen Non‐LTE Model Atmosphere Package (TMAP) can calculate such model atmospheres at a high level of sophistication. Although TMAP is not especially designed for the calculation of spectral energy distributions (SEDs) at extreme photospheric parameters, it can be employed for the spectral analysis ofburst spectra of novae like V4743 Sgr or line identifications in observations of neutron stars with low magnetic fields in low‐mass X‐ray binaries (LMXBs) like EXO 0748‐676 (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
X‐ray energy spectra of CAL87
Authors: Ebisawa K. , Rauch T. , Takei D. 
Published: February 2010

AbstractWe present X‐ray spectral analysis of the super‐soft source CAL87 using ASCA, Chandra, XMM‐Newton observations. Early ASCA CCD spectrum reported a strong oxygen absorption edge, which is considered to originate in the an optically thick white‐dwarf atmosphere. On the other hand, contemporaneous grating observations by Chandra and XMM‐Newton indicate emission line dominated spectra, which obviously indicate the optically thin origin. Fitting all the available CCD (ASCA and XMM‐Newton) and grating spectra (XMM‐Newton and Chandra) simultaneously, we show that the CAL87 X‐ray energy spectrum is in fact composed of both an optically thick component with deep absorption edges and an optically thin component with numerous emission lines. The current result supports the standard SSS model that the primary source of X‐ray emission is nuclear burning in the white dwarf atmosphere, surrounded by a highly photoionised, optically thin corona (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Swift observations of CSS081007:030559+054715
Authors: Beardmore A.P. , Osborne J.P. , Page K.L. , Schwarz G. , Starrfield S. , Hakala P. , Ness J.‐U. , Balman S. , Wagner R.M. 
Published: February 2010

AbstractCSS081007:030559+054715 was discovered by the Catalina Real‐time Transient Survey. Optical spectroscopy revealed a multi‐peaked Hα emission line profile with radial velocities exceeding 1500 km/s, as well as strong Ne emission, suggestive of a neon nova. We monitored the source extensively with the Swift satellite, obtaining a unique dataset spanning 270 days in the soft X‐ray and UV bands. The data reveal a soft, blackbody‐like spectrum with a temperature around 55 eV (though dependent on the modelling), variable X‐ray and UV light curves with a 1.77 day period in both the X‐ray and UV bands, a longer timescale modulation of ∼ 50 days, followed by a slowly declining trend in the soft X‐ray and UV flux. We highlight the Swift observations and their implications for the SSS nature of this object (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Expanding atmosphere models for SSS spectra of novae
Authors: Rossum D.R. van , Ness J.‐U. 
Published: February 2010

AbstractSuper Soft Source (SSS) spectra are powered by nuclear burning on the surface of a white dwarf. The released energy causes a radiatively‐driven wind that leads to a radially extended atmosphere around the white dwarf. Significant blue shifts in photospheric absorption lines are found in the spectra of novae during their SSS phase, being an evidence of continued mass loss in this phase. We present spherically symmetric PHOENIX models that account for the expansion of the ejecta. A comparison to a plane parallel, hydrostatic atmosphere model demonstrates that the mass loss can have a significant impact on the model spectra. The dynamic model yields less pronounced absorption edges, and harder X‐ray spectra are the result. Therefore, lower effective temperatures are needed to explain the observed spectra. Although both types of models are yet to be fine‐tuned in order to accurately determine best fit parameters, the implications on the chemical abundances are going in opposite directions. With the expanding models the requirement for strong depletion of the crucial elements that cause these edges is now avoidable (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Observational evidence for expansion in the SSS spectra of novae
Authors: Ness J.‐U. 
Published: February 2010

AbstractFor several novae, a bright X‐ray source with a spectrum resembling the class of Super Soft X‐ray Sources (SSS) has been observed a few weeks to months after outburst. Novae are powered by explosive nuclear burning on the surface of a white dwarf, and enough energy is produced to power a radiatively driven wind. Owing to the evolution of the opacity of the ejecta, the observable spectrum gradually shifts from optical to soft X‐rays (SSS phase). It has sometimes been assumed that at the beginning of the SSS phase no more mass loss occurs. However, high‐resolution X‐ray spectra of some novae have shown highly blue‐shifted absorption lines, indicating a significant expansion. In this paper, I show that all novae that have been observed with X‐ray gratings during their SSS phase show significant blue shifts. I argue that all models that attempt to explain the X‐ray bright SSS phase have to accommodate the continued expansion of the ejecta (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Recent discoveries of supersoft X‐ray sources in M 31
Authors: Henze M. , Pietsch W. , Haberl F. , Sala G. , Hernanz M. , Hatzidimitriou D. , Rau A. , Hartmann D.H. , Greiner J. , Orio M. , Stiele H. , Freyberg M.J. 
Published: February 2010

AbstractClassical novae (CNe) have recently been reported to represent the major class of supersoft X‐ray sources (SSSs) in the central area of our neighbouring galaxy M 31. This paper presents a review of results from recent X‐ray observations of M 31 with XMM‐Newton and Chandra. We carried out a dedicated optical and X‐ray monitoring program of CNe and SSSs in the central area ofM 31. We discovered the first SSSs in M 31 globular clusters (GCs) and their connection to the very first discovered CN in a M 31 GC. This result may have an impact on the CN rate in GCs. Furthermore, in our optical and X‐ray monitoring data we discovered the CN M3 1N 2007‐11a, which shows a very short SSS phase of 29–52 days. Short SSS states (durations ≤ 100 days) of CNe indicate massive white dwarfs (WDs) that are candidate progenitors of supernovae type Ia. In the case of M31N 2007‐11a, the optical and X‐ray light curves suggest a binary containing a WD withMWD> 1.0 M⊙. Finally, we present the discovery of the SSS counterpart of the CN M31N 2006‐04a. The X‐ray light curve of M31N 2006‐04a shows short‐time variability, which might indicate an orbital period of about 2 hours (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Populations of supersoft X‐ray sources: Novae, tidal disruption, Type Ia supernovae, accretion‐induced collapse, ionization, and intermediatemass black holes?
Authors: Stefano R. Di , Primini F.A. , Liu J. , Kong A. , Patel B. 
Published: February 2010

AbstractObservations of hundreds of supersoft X‐ray sources (SSSs) in external galaxies have shed light on the diversity of the class and on the natures of the sources. SSSs are linked to the physics of Type Ia supernovae and accretion‐induced collapse, ultraluminous X‐ray sources and black holes, the ionization of the interstellar medium, and tidal disruption by supermassive black holes. The class of SSSs has an extension to higher luminosities: ultraluminous SSSs have luminosities above 1039 erg s–1. There is also an extension to higher energies: quasisoft X‐ray sources (QSSs) emit photons with energies above 1 keV, but few or none with energies above 2 keV. Finally, a significant fraction of the SSSs found in external galaxies switch states between observations, becoming either quasisoft or hard. For many systems “supersoft” refers to a temporary state; SSSs are sources, possibly including a variety of fundamentally different system types, that pass through such a state. We review those results derived from extragalactic data and related theoretical work that are most surprising and that suggest directions for future research (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Supersoft sources in M31: Comparing the XMM‐Newton deep survey, ROSAT and Chandra catalogues
Authors: Stiele H. , Pietsch W. , Haberl F. , Burwitz V. , Hatzidimitriou D. , Greiner J. 
Published: February 2010

AbstractTo investigate the transient nature of supersoft sources (SSSs) in M 31, we compared SSS candidates ofthe XMM‐Newton Deep Survey, ROSAT PSPC surveys and the Chandra catalogues in the same field. We found 40 SSSs in the XMM‐Newton observations. While 12 of the XMM‐Newton sources were brighter than the limiting flux of the ROSAT PSPC survey, only two were detected with ROSAT ∼10 yr earlier. Five correlate with recent optical novae which explains why they were not detected by ROSAT. The remaining 28 XMM‐Newton SSSs have fluxes below the ROSAT detection threshold. Nevertheless we found one correlation with a ROSAT source, which had significantly larger fluxes than during the XMM‐Newton observations. Ten of the XMM‐Newton SSSs were detected by Chandra with <1– ∼6yr between the observations. Five were also classified as SSSs by Chandra. Of the 30 ROSAT SSSs three were confirmed with XMM‐Newton, while for 11 sources other classifications are suggested. Of the remaining 16 sources one correlates with an optical nova. Of the 42 Chandra very‐soft sources five are classified as XMM‐Newton SSSs, while for 22 we suggest other classifications. Of the remaining 15 sources, nine are classified as transient by Chandra, one of them correlates with an optical nova. These findings underlined the high variability of the sources of this class and the connection between SSSs and optical novae. Only three sources, were detected by all three missions as SSSs. Thus they are visible for more than a decade, despite their variability (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
SSS in young stellar populations and the “prompt” component of Type Ia supernovae
Authors: Nelson T. , Orio M. , Mille F. Di 
Published: February 2010

AbstractWe present the results of a search for UV and optical counterparts of the SSS population in M 31. We find that out of the 56 sources we included in our search, 16 are associated with regions of ongoing or recent star formation. We discuss two particularly interesting sources that are identified optically as early type stars, one of which displayed long term X‐ray evolution similar to that observed in classical novae. We discuss the physical origin of supersoft X‐rays in these and the other SSS in young regions, and their possible link to the so‐called “prompt” component of the Type Ia supernova population (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the relation between supersoft X‐ray sources and VY Scl stars: The cases of V504 Cen and VY Scl
Authors: Greiner J. , Schwarz R. , Tappert C. , Mennickent R.E. , Reinsch K. , Sala G. 
Published: February 2010

AbstractWe summarise our optical monitoring program of VY Scl stars with the SMARTS telescopes, and triggered X‐ray as well as optical observations after/during state transitions of V504 Cen and VY Scl (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Supersoft AGNs and their relations to Galactic binaries
Authors: Boller Th. 
Published: February 2010

AbstractI review some basic results on AGN with supersoft X‐ray spectra and their relations to Galactic binaries in their soft high states. This paper is based on a talk given at the Supersoft Sources Workshop at ESTEC in May 2009. Given the length of the talk and the number of pages the review cannot be complete and is biased towards my personal view. I demonstrate that at high accretion rates supersoft AGNs and Galactic binaries share steep soft X‐ray spectra, that the X‐ray variability of supersoft AGNs is more pronounced compared to Galactic binaries in their high states, that the X‐ray variability of supersoft novae and supersoft AGNs is similar, and that in Galactic binaries mostly positive time lags are seen, while negative time lags are observed in some supersoft AGN (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Oral cleft defects and maternal exposure to ambient air pollutants in New Jersey
Authors: Marshall Elizabeth G. , Harris Gerald , Wartenberg Daniel 
Published: February 2010

AbstractBACKGROUNDEvidence links exposure to ambient air pollution during pregnancy, particularly gaseous pollutants and particulate matter, to an increased risk of adverse reproductive outcomes though the results for birth defects have been inconsistent.METHODSWe compared estimated exposure to ambient air pollutants during early pregnancy among mothers of children with oral cleft defects (cases) to that among mothers of controls, adjusting for available risk factors from birth certificates. We obtained ambient air pollutant data from air monitoring sites in New Jersey for carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), sulfur dioxide (SO2), particulate matter <10 μm in aerodynamic diameter (PM10) and particulate matter <2.5 μm in aerodynamic diameter (PM2.5). We used values from the nearest monitor (within 40 km of the residence at birth) for controls, cleft lip with or without cleft palate (CLP) and cleft palate only (CPO).RESULTSBased on logistic regression analyses for each contaminant and all contaminants together, there were no consistent elevated associations between selected air pollutants and cleft malformations. Quartile of CO concentration showed a consistent protective association with CPO (p < 0.01). For other contaminants, confidence intervals (95%) of the odds ratios for some quartiles excluded one. CLP showed limited evidence of an association with increasing SO2 exposure while CPO showed weak associations with increasing O3 exposure.CONCLUSIONThere was little consistent evidence associating cleft malformations with maternal exposure to ambient air pollutants. Evaluating particular pollutants or disease subgroups would require more detailed measurement of exposure and classification of cleft defects. Birth Defects Research (Part A), 2010. © 2010 Wiley‐Liss, Inc.
Complete stent dislodgement after successful implantation‐a rare case
Authors: Gan Hwa Wooi , Bhasin Anuj , Wu Chiung‐Jen 
Published: February 2010

AbstractA successfully deployed stent is normally stable in position and unlikely to be dislodged from the coronary artery. We report a case of complete stent dislodgement after successful implantation in a patient with recent anterior myocardial infarction (AMI). Coronary angulation, a highly calcified coronary artery, an under‐deployed stent, and the process of rewiring contributed to this unexpected event. Fortunately, no unwanted complication occurred as a consequence of this event. © 2010 Wiley‐Liss, Inc.
Detecting Operational Inactivation of Horseradish Peroxidase using an Isoconversional Method
Authors: Puiu M. , Constantinovici M. , Babaligea I. , Raducan A. , Olmazu C. , Oancea D. 
Published: February 2010

AbstractKinetic parameters of operational inactivation of horseradish peroxidase during the enzymatic oxidation of 2‐aminophenol with hydrogen peroxide were estimated using an isoconversional method. This method only requires the progress kinetic curves obtained at constant initial concentrations of the substrates. In order to investigate the possible pathways of low‐reactive species compound III formation, a kinetic model was proposed and several rate constants were calculated using an optimization computing program. Generation of an oxygen reactive species in the reaction system was also considered in the reaction scheme. Sensitivity analysis, corroborated with the overall inactivation kinetics observed with the isoconversional method, allows the conclusion that the inactivation of the enzyme occurs mainly via the reaction of compound II with hydrogen peroxide.
Prediction of Layer‐Inversion Behavior of Down‐Flow Binary Solid‐Liquid Fluidized Beds
Authors: Asif M. 
Published: February 2010

AbstractThe layer‐inversion behavior of down‐flow binary solid‐liquid fluidized beds is predicted using the property‐averaging approach. The binary pair in this case consists of a larger solid species which is also heavier than its smaller counterpart, while both are lighter than the fluidizing medium. The model is based on using the generalized Richardson‐Zaki correlation for evaluation of the bed void fraction wherein mean values of particle properties are used. However, unlike the maximum bulk density condition for the conventional up‐flow binary solid fluidized bed, the model is based on a minimum bulk density condition for occurrence of layer inversion. This is due to the fact that the volume contraction phenomenon associated with the mixing of unequal solid species leads to a decrease in bulk density of the bed. Model predictions are also compared using the limited data available in the literature. Predictions are consistent with the observed mixing behavior.
Reducing Energy Consumption and CO2 Emissions in Thermally Coupled Azeotropic Distillation
Authors: Sun L.‐Y. , Chang X.‐W. , Zhang Y.‐M. , Li J. , Li Q.‐S. 
Published: February 2010

AbstractThe design and optimization procedures of a heterogeneous thermally coupled azeotropic distillation sequence with a side stripper (TCADS‐SS) for the purification of isopropanol has been investigated. The proposed procedures can detect the optimal values of the design variables and thereby guarantee the minimum energy consumption, which is related to the minimum CO2 emissions and the lowest total annual cost (TAC). The procedures are applied to the study of the separation of azeotropic mixtures using the two distillation sequences. In the TCADS‐SS, the top end of the side stripper has both liquid and vapor exchange with the main column, which eliminates a condenser in contrast with the conventional heterogeneous azeotropic distillation sequence (CHADS). The results show that not only reductions in energy consumption and CO2 emissions but also higher thermodynamic efficiency can be obtained for the TCADS‐SS.