bluuebunny/crossref_metadata_2025_split huggingface dataset:
Osseointegration assessment of chairside argon‐based nonthermal plasma‐treated Ca‐P coated dental implants
Authors: Giro Gabriela , Tovar Nick , Witek Lukasz , Marin Charles , Silva Nelson R. F. , Bonfante Estevam A. , Coelho Paulo G. 
Published: July 2012

AbstractThis study investigated the effect of an Argon‐based nonthermal plasma (NTP) surface treatment‐operated chairside at atmospheric pressure conditions applied immediately prior to dental implant placement in a canine model. Surfaces investigated comprised: Calcium‐Phosphate (CaP) and CaP + NTP (CaP‐Plasma). Surface energy was characterized by the Owens‐Wendt‐Rabel‐Kaelble method and chemistry by X‐ray photoelectron spectroscopy (XPS). Six adult beagles dogs received 2 plateau‐root form implants (n = 1 each surface) in each radii, providing implants that remained 1 and 3 weeks in vivo. Histometric parameters assessed were bone‐to‐implant contact (BIC) and bone area fraction occupancy (BAFO). Statistical analysis was performed by Kruskall‐Wallis (95% level of significance) and Dunn's post‐hoc test. The XPS analysis showed peaks of Ca, C, O, and P for the CaP and CaP‐Plasma surfaces. Both surfaces presented carbon primarily as hydrocarbon (CC, CH) with lower levels of oxidized carbon forms. The CaP surface presented atomic percent values of 38, 42, 11, and 7 for C, O, Ca, and P, respectively, and the CaP‐Plasma presented increases in O, Ca, and P atomic percent levels at 53, 12, and 13, respectively, in addition to a decrease in C content at 18 atomic percent. At 1 week no difference was found in histometric parameters between groups. At 3 weeks significantly higher BIC and BAFO were observed for CaP‐Plasma treated surfaces. Surface elemental chemistry was modified by the Ar‐based NTP. Ar‐based NTP improved bone formation around plateau‐root form implants at 3 weeks compared with CaP treatment alone. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A:98–103, 2013.
Defining Sets and Critical Sets in (0,1)‐Matrices
Authors: Cavenagh Nicholas J. 
Published: July 2012

AbstractIf D is a partially filled‐in (0, 1)‐matrix with a unique completion to a (0, 1)‐matrix M (with prescribed row and column sums), we say that D is a defining set for M. If the removal of any entry of D destroys this property (i.e. at least two completions become possible), we say that D is a critical set for M. In this note, we show that the complement of a critical set for a (0, 1)‐matrix M is a defining set for M. We also study the possible sizes (number of filled‐in cells) of defining sets for square matrices M with uniform row and column sums, which are also frequency squares. In particular, we show that when the matrix is of even order 2m and the row and column sums are all equal to m, the smallest possible size of a critical set is precisely m2. We give the exact structure of critical sets with this property. © 2012 Wiley Periodicals, Inc. J. Combin. Designs 21: 253–266, 2013
An asymptotically tight bound on the adaptable chromatic number
Authors: Molloy Michael , Thron Giovanna 
Published: July 2012

AbstractThe adaptable chromatic number of a multigraph G, denoted χa(G), is the smallest integer k such that every edge labeling, τ, of G from [k] = {1, 2, …, k} permits a vertex coloring, σ, of G from [k] such that no edge e = uv has τ(e) = σ(u) = σ(v). Hell and Zhu proved that for any multigraph G with maximum degree Δ, the adaptable chromatic number is at most . We strengthen this to the asymptotically best possible bound of for any ɛ>0. © 2012 Wiley Periodicals, Inc. J Graph Theory
Do Tourism Receipts Contribute to the Sustainability of Current Account Deficits: a Case Study of Barbados
Authors: Lorde Troy , Lowe Shane , Francis Brian 
Published: July 2012

ABSTRACTGiven Barbados’ recent history of persistent current account deficits and reliance on tourism as a major source of foreign exchange and driver of the economy, this paper investigated the contribution of tourism receipts to the sustainability of Barbados’ current account deficits. Utilizing an inter‐temporal budget approach, it was found that Barbados’ current account deficits were weakly sustainable as a result of tourism's contribution, underscoring the island's dependence on the industry. Copyright © 2012 John Wiley & Sons, Ltd.
Quantum Chemical Investigation of Secondary Reactions in Poly(vinyl chloride) Free‐Radical Polymerization
Authors: Cuccato Danilo , Dossi Marco , Moscatelli Davide , Storti Giuseppe 
Published: July 2012

AbstractFree‐radical polymerization of vinyl chloride is investigated computationally with special attention to the secondary reactions involving mid‐chain radicals (MCRs). Namely, the rate constants of backbiting, chain scission, chain transfer, and propagation reactions are evaluated using a density functional theory method. The rate coefficients of such reactions are estimated taking into account the position of the radical along the chain as well as its distance from the chain‐end. In particular 1:5, 5:1, and 5:9 backbiting are the most relevant secondary reactions, followed by the slower propagation of MCRs. Finally, a kinetic model of suspension polymerization including the investigated reactions is developed, in order to determine their impact on the quality of the final polymer. magnified image
Graft Copolymers for Blend Compatibilization: Mathematical Modeling of the Grafting Process
Authors: Gianoglio Pantano Ioana A. , Asteasuain Mariano , Sarmoria Claudia , Brandolin Adriana 
Published: July 2012

AbstractThe grafting of PE onto PS through a Friedel‐Crafts reaction, which results in a mixture of PE‐g‐PS copolymer, unmodified PE, and modified PS, is investigated. The copolymer may be suitable for compatibilization of immiscible mixtures in the household plastic waste stream, where PE and PS are majority components. Since the compatibilization effect depends on the composition and block lengths in the copolymer, a model is presented for predicting the complete molecular weight distribution of the homopolymers and the chemical composition distribution of the graft copolymer. The model has potential for application in an optimization tool for the compatibilization process, as it is able to account for the opposing effects of competing reactions that characterize the graft reaction. magnified image
Simultaneous single‐quantum and triple‐quantum‐filtered MRI of 23Na (SISTINA)
Authors: Fiege Daniel P. , Romanzetti Sandro , Mirkes Christian C. , Brenner Daniel , Shah N. Jon 
Published: July 2012

AbstractThe low MR sensitivity of the sodium nucleus and its low concentration in the human body constrain acquisition time. The use of both single‐quantum and triple‐quantum sodium imaging is, therefore, restricted. In this work, we present a novel MRI sequence that interleaves an ultra‐short echo time radial projection readout into the three‐pulse triple‐quantum preparation. This allows for simultaneous acquisition of tissue sodium concentration weighted as well as triple‐quantum filtered images. Performance of the sequence is shown on phantoms. The method is demonstrated on six healthy informed volunteers and is applied to three cases of brain tumors. A comparison with images from tumor specific O‐(2‐[18F]fluoroethyl)‐L‐tyrosine positron emission tomography and standard MR images is presented. The combined information of the triple‐quantum‐filtered images with single‐quantum images may enable a better understanding of tissue viability. Future studies can benefit from the evaluation of both contrasts with shortened acquisition times. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Toward cardiovascular interventions guided by magnetic particle imaging: First instrument characterization
Authors: Haegele Julian , Biederer Sven , Wojtczyk Hanne , Gräser Matthias , Knopp Tobias , Buzug Thorsten M. , Barkhausen Jörg , Vogt Florian M. 
Published: July 2012

AbstractMagnetic particle imaging has emerged as a new technique for the visualization and quantification of superparamagnetic iron oxide nanoparticles. It seems to be a very promising application for cardiovascular interventional radiology. A prerequisite for interventions is the artifact‐free visualization of the required instruments and implants. Various commercially available catheters, guide wires, and a catheter experimentally coated with superparamagnetic iron oxide nanoparticles were tested regarding their signal characteristics using magnetic particle spectroscopy to evaluate their performance in magnetic particle imaging. The results indicate that signal‐generating and non‐signal‐generating instruments can be distinguished. Furthermore, coating or loading non‐signal‐generating instruments with superparamagnetic iron oxide nanoparticles seems to be a promising approach, but optimized nanoparticles need yet to be developed. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
A standardized scan statistic for detecting spatial clusters with estimated parameters
Authors: Shu Lianjie , Jiang Wei , Tsui Kwok‐Leung 
Published: July 2012

AbstractThe scan statistic based on likelihood ratios (LRs) have been widely discussed for detecting spatial clusters. When developing the scan statistic, it uses the maximum likelihood estimates of the incidence rates inside and outside candidate clusters to substitute the true values in the LR statistic. However, the parameter estimation has a significant impact on the sensitivity of the scan statistic, which favors the detection of clusters in areas with large population sizes. By presenting the effects of parameter estimation on Kulldorff's scan statistic, we suggest a standardized scan statistic for spatial cluster detection. Compared to the traditional scan statistic, the standardized scan statistic can account for the varying mean and variance of the LR statistic due to inhomogeneous background population sizes. Extensive simulations have been performed to compare the power of the two cluster detection methods with known or/and estimated parameters. The simulation results show that the standardization can help alleviate the effects of parameter estimation and improve the detection of localized clusters. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012
Bayesian analysis of queues with impatient customers: Applications to call centers
Authors: Aktekin Tevfik , Soyer Refik 
Published: July 2012

AbstractQueuing models have been extensively used in the literature for obtaining performance measures and developing staffing policies. However, most of this work has been from a pure probabilistic point of view and has not addressed issues of statistical inference. In this article, we consider Bayesian queuing models with impatient customers with particular emphasis on call center operations and discuss further extensions. We develop the details of Bayesian inference for queues with abandonment such as the M/M/s + M model (Erlang‐A). In doing so, we discuss the estimation of operating characteristics and its implications on staffing. We illustrate the implementation of the Bayesian models using actual arrival, service, and abandonment data from call centers. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012
PROMIS pediatric measures in pediatric oncology: Valid and clinically feasible indicators of patient‐reported outcomes
Authors: Hinds Pamela S. , Nuss Suzanne L. , Ruccione Kathleen S. , Withycombe Janice S. , Jacobs Shana , DeLuca Holly , Faulkner Charisse , Liu Yang , Cheng Yao I. , Gross Heather E. , Wang Jichuan , DeWalt Darren A. 
Published: July 2012

AbstractBackgroundEstablishing the ability of children and adolescents with cancer to complete the NIH‐sponsored PROMIS pediatric measures electronically and the preliminary validity estimates of the measures (both full item banks and short forms) in pediatric oncology will contribute to our knowledge of the impact of cancer treatment on these young patients.ProceduresA total of 203 8‐ to 17‐year olds were administered eight PROMIS pediatric measures in a cross‐sectional study design to establish known‐group validity. Of the 200 who completed all or most of the items, a slight majority were male (55.5%) and white (54%). Patients were either undergoing treatment for cancer (n = 93) or in survivorship following treatment for cancer (n = 107). Measures were completed using computer interface during an in‐person interaction with researchers.ResultsOnly 3 of 203 participants did not complete the PROMIS pediatric measures. As hypothesized, participants in treatment were significantly different (worse) on parent‐reported clinical indicators (blood counts, fatigue, and appetite) and on seven self‐reported measures (depression, anxiety, peer relationships, pain interference, fatigue, upper extremity function, and mobility) from participants in survivorship. Females reported worse fatigue, anger, and pain interference than males. Worse patient‐reported outcomes for patients in active treatment persisted after adjusting for potential confounding variables.ConclusionsChildren and adolescents in treatment for cancer or in survivorship and ranging from 8 to 17 years of age can complete multiple PROMIS pediatric measures using a computer interface during an outpatient clinic visit or inpatient admission. Findings establish known‐group validity for PROMIS pediatric measures in pediatric oncology. Pediatr Blood Cancer 2013; 60: 402–408. © 2012 Wiley Periodicals, Inc.
Guiding of Reactive Plasma Species by Micro‐Channels
Authors: Li Yang‐Fang , Zimmermann Julia L. , Klämpfl Tobias , Morfill Gregor E. 
Published: July 2012

AbstractWe investigate the effect of the micro‐channel plate (MCP) on the diffusive transport of reactive plasma species generated by a cold atmospheric discharge. The diffusion of the reactive plasma species is guided by the micro‐channels and the side diffusion is consequently reduced. Therefore the reactive plasma species are more effectively transported to the target surface. A higher bactericidal efficiency is found in comparison with the open, unhindered configuration when the open area ratio of the MCP equals 50%. Furthermore, the experimental results show a significant UV reduction because of the shielding by the MCP. magnified image
Using layer of protection analysis to understand necessary safeguards for steam boiler operation
Authors: Morrison Delmar “Trey” , Fecke Mark , Ramirez Juan 
Published: July 2012

AbstractMost chemical process plants, petrochemical facilities, and electrical power utilities rely on steam boilers to provide motive power, electricity, and process steam for operations. Safe operation, startup, and shutdown of these boilers require many levels of operational/controls safeguards. The design and selection of safeguards is often guided by the original design of the boiler, equipment manufacturers, internal company standards, and recognized authoritative standards. In the United States, the National Fire Protection Association (NFPA) has promulgated NFPA 85 Boiler and Combustion Systems Hazards Code. This prescriptive code identifies necessary safeguards along with “listing” and “labeling” requirements for some components used as safeguards; however, the Safety Integrity Levels for the multiple safeguard systems have not been quantified. In this article, we use Layer of Protection Analysis methods along with generally accepted probabilities and frequencies of failures to provide a quantitative framework for an owner, operator, or manufacturer to use in designing or evaluating the multiple safeguards necessary for safe steam boiler operation. As part of the analysis, we have provided case studies of boiler failures with a discussion of how additional layers of protection may be either ineffective or missing. © 2012 American Institute of Chemical Engineers Process Saf Prog, 2012
How to be effective in a process safety role
Authors: Klein James A. 
Published: July 2012

AbstractMany factors contribute to being capable and effective in process safety roles. Certainly, understanding of engineering and process safety is desirable to establish basic technical competence. Ultimately, true capability and career success also requires the ability to work within an organization to help achieve superior and effective performance. This article discusses how to be effective in a process safety role by developing a strong foundation of technical knowledge and capability, by learning to influence the organization, and by thinking and communicating independently. The result should be career success as well as improved process safety performance, helping to prevent serious injuries and incidents. © 2012 American Institute of Chemical Engineers Process Saf, 2012.
High‐contrast 2D etched holes array obtained by direct laser writing on chalcogenide As2S3 films
Authors: Popescu Aurelian , Savastru Dan , Savastru Roxana , Miclos Sorin , Socol Gabriel , Mihailescu Ion N. 
Published: July 2012

AbstractThis paper studies optical, chemical and photoinduced changes in amorphous AsS films, obtained by nanosecond pulsed‐laser ablation of a As40S60 target. The arsenic content of the films is slightly higher than the target composition and depends on the ablation fluence. The photobleaching phenomenon appears after 1–2 min of bandgap laser irradiation. The refractive index diminishes by 0.07 and the transmission approximately doubles. It was established for the first time that films obtained by pulsed laser deposition exhibit a positive resist behavior in amine‐containing etchant. The etching rate of the irradiated film was 0.12 µm/min, while as‐deposited films have lower etching rate. The measured selectivity rate was of 14:1. A 2D high‐quality hole array was produced by direct laser writing and further etching. The unusual behavior can be a result of different glass network formation during the condensation of AsSn molecules sputtered from the bulk target. This is different from the case of thermally evaporated films where AsS1 molecules only were identified in gas‐phase by mass spectrometry.
Computational modeling of wet TiO2 (001) anatase surfaces functionalized by transition metal doping
Authors: Zhang Yuchi , Kilin Dmitri S. 
Published: July 2012

AbstractTitanium dioxide anatase nanostructure is a photocatalyst under UV light. Our objective is to discover proper surface and functionalization, which facilitate the efficiency of photocatalytic water splitting on TiO2 crystals. We set up a periodic model of Ti32O64·8H2O as the neutral structure and expose the (001) crystallographic surface as it is more reactive. Using platinum, cobalt, and ruthenium to dope in the (001) crystallographic surface and get Ti30Me2O64·8H2O, which Me stands for either Pt, Co, or Ru. Based on density functional theory and Perdue Burke Ernzerhof functional (PBE) we calculate and optimize the doped nanostructures using VASP software. Through their density of states, we can analyze the possibility of charge transfer at the crystal surface and compare how the doping elements affect the charge transfer direction. A comparison of the computed absorption spectra and the charge density of the doping nanostructures help us in better understanding of the possibility of the bandgap tuning in photocatalytic energy nanomaterials. © 2012 Wiley Periodicals, Inc.
Time dependent wave packet treatment of 2ΠgN2− and 3Σ−NO− shape resonances using two‐dimensional surfaces for electron‐N2 and NO interactions
Authors: Shandilya Bhavesh K. , Sarma Manabendra , Adhikari Satrajit , Mishra Manoj K. 
Published: July 2012

AbstractThe 2ΠgN and 3Σ−NO− resonances in electron‐N2 and NO collisions have been treated using both nuclear and electronic degrees of freedom and a two‐dimensional (2D) time dependent wave packet approach to ascertain the importance of nonlocality in electron–nuclear interaction. The results so obtained are compared with vibrational excitation cross‐sections obtained experimentally and those from other theoretical/numerical approaches using 1D local complex potential, 2D model with a combination of the exterior complex scaling method and a finite‐element implementation of the discrete‐variable representation. The results obtained provide detailed insight into the nuclear dynamics induced by electron–molecule collision and reveal that while for resonant excitation of lower vibrational modes, the nonlocal effect may not be as critical but importance of nonlocal effects may increase with increase in quanta of resonant vibrational excitation. © 2012 Wiley Periodicals, Inc.
An improved CeO2 method for high‐precision measurements of 17O/16O ratios for atmospheric carbon dioxide
Authors: Mahata Sasadhar , Bhattacharya Sourandra K. , Wang Chung‐Ho , Liang Mao‐Chang 
Published: July 2012

RATIONALEThe oxygen isotopic composition of carbon dioxide originating at the Earth's surface is modified in the stratosphere by interaction with ozone which has anomalous oxygen isotope ratio (Δ17O = 1000 * ln(1 + δ17O/1000) – 0.522 * 1000 * ln (1 + δ18O/1000) >0). The inherited anomaly provides a powerful tracer for studying biogeochemical cycles involving CO2. However, the existing methods are either too imprecise or have difficulty in determining the small Δ17O variations found in the tropospheric CO2. In this study an earlier published CeO2 and CO2 exchange method has been modified and improved for measuring the Δ17O values of atmospheric carbon dioxide with high precision.METHODSThe CO2 fraction from air samples was separated by cryogenic means and purified using gas chromatography. This CO2 was first analyzed in an isotope ratio mass spectrometer, then artificially equilibrated with hot CeO2 to alter its oxygen isotopes mass‐dependently and re‐analyzed. From these data the 17O/16O and 18O/16O ratios were calculated and the Δ17O value was determined.RESULTSThe validity of the method was established in several tests by using artificially prepared CO2 with zero and non‐zero Δ17O values. The published value of the CO2‐H2O equilibrium slope was also reproduced.CONCLUSIONSThe CO2‐CeO2 equilibration method has been improved to measure the oxygen isotope anomaly (Δ17O value) of atmospheric CO2 with an analytical precision of ±0.12‰ (2σ). Copyright © 2012 John Wiley & Sons, Ltd.