bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bias adjustment and long‐term verification of radar‐based precipitation estimates
Authors: Holleman Iwan 
Published: August 2007

AbstractQuantitative precipitation estimates (QPE) based on weather radar observations are used more and more for water management, in numerical weather prediction models, and for monitoring of severe weather. A straightforward method for bias adjustment of radar‐based and hourly‐updated precipitation accumulations is described. In addition a long‐term verification of the bias‐adjusted composites over a six year period using dependent and independent gauge data is presented. It is found that the adjustment scheme effectively removes the mean‐field bias from the raw accumulations. The adjustment method cannot correct for a range‐dependent bias and therefore it is recommended to also use a simple vertical profile of reflectivity (VPR) adjustment procedure. Copyright © 2007 Royal Meteorological Society
Comparison of VAAC atmospheric dispersion models using the 1 November 2004 Grimsvötn eruption
Authors: Witham C. S. , Hort M. C. , Potts R. , Servranckx R. , Husson P. , Bonnardot F. 
Published: August 2007

AbstractThe robustness of the Numerical Atmospheric‐dispersion Modelling Environment (NAME) for forecasting the dispersion of volcanic ash clouds is investigated by comparing the output from different Volcanic Ash Advisory Centre (VAAC) models initialised using the parameters for the 2004 Grimsvötn, Iceland, volcanic eruption. London, Darwin, Washington, Montreal and Toulouse VAAC dispersion models are all run operationally as if responding to the eruption. Comparison of the model set‐ups reveals differing approaches between the VAACs for model averaging times, ash release rates, and thresholds for defining the ash cloud, amongst others. The importance of these factors is considered in detail. Despite using different weather conditions and having different structures, the models all demonstrate strong similarities for forecasting regional ash cloud transport. The dispersal of volcanic ash is simulated over Scandinavia and as far as Eastern Europe in all cases. Greater variations are seen between the forecast ash concentrations for different aircraft flight levels. The model forecasts are highly dependent on the amount of eruption information available at the time. Copyright © 2007 Royal Meteorological Society
Weather conditions associated with the potential for pollen recirculation in a coastal area
Authors: Gassmann María Isabel , Gardiol Jesús María 
Published: August 2007

AbstractThis study aims to characterise the main synoptic field patterns associated with the potential for recirculation of pollen. A recirculation index (R) was calculated in the area of Mar del Plata, Argentina. The daily development of sea–land breeze and the related monthly frequencies of wind directions were studied. The sea breeze was present for 36.2% of the time, with a mean lifetime of about 2 h in winter and 15–20 h in summer. Recirculation of the air had an annual frequency of around 7%, with a net transport from the city outskirts towards the sea, for 39.4% of the year, and a net inland transport frequency of 38.4%. The Rotated Principal Component Analysis (PCA) was applied to obtain synoptic field patterns associated with potential conditions for recirculation in the area. It was shown that low‐pressure systems or troughs between 45° and 60°S (i.e. over the country, the South Pacific and/or the South Atlantic and two anticyclones located in the Atlantic or South Pacific Oceans) are the most common weather conditions associated with air recirculation in the coastal area of Buenos Aires province. A case study with high night pollen concentrations was also analysed. Copyright © 2007 Royal Meteorological Society
The development of a rating scale to screen social and emotional detachment in children and adolescents
Authors: Scholte E. M. , van der Ploeg J. D. 
Published: August 2007

AbstractRating scales to assess psychopathic characteristics in children and adolescents show a considerable item overlap with rating scales to assess attention deficit hyperactivity disorder (ADHD), oppositional‐defiant disorder (ODD) and conduct disorder (CD) symptoms. The aim of this study is to preliminary test a short questionnaire clinicians can use to screen the unique characteristics of psychopathy. Parental ratings of psychopathic characteristics and symptoms of ADHD, ODD and CD were gathered in a community sample of 2535 4–18‐year‐old Dutch children. The dimensionality of the ratings was determined by factor analysis and related to ADHD, ODD and CD. Two factors emerged covering egocentric‐narcissistic and callous‐unemotional characteristics. To avoid unnecessary stigmatization of youngsters the first factor is referred to as the “social detachment dimension” and the second as the “emotional detachment dimension”. Parental ratings were reliable across all age and gender groups, and correlated moderately with ODD and CD, but not with ADHD. Preliminary findings support a two‐dimensional syndrome depicting respectively narcissistic and unemotional characteristics. The syndrome is associated with ODD and CD symptoms and possibly depicts a subtype of the ODD/CD childhood disorder. Copyright © 2007 John Wiley & Sons, Ltd.
Catalase overexpression does not impair extensor digitorum longus muscle function in normal mice
Authors: Liu Mingju , Yue Yongping , Li Dejia , Duan Dongsheng 
Published: August 2007

AbstractCatalase is a major antioxidant enzyme. Increasing catalase expression represents a promising avenue to improve muscle function in certain physiological conditions and in some muscle diseases. We hypothesized that catalase overexpression should not impair normal muscle contraction. We delivered a hemagglutinin (HA)‐tagged human catalase gene to normal mouse muscle by an adeno‐associated viral vector (AAV). Western blot and immunostaining revealed efficient expression of HA‐tagged catalase. Enzymatic assay demonstrated an approximately threefold increase in catalase activity in AAV‐infected muscles. Catalase overexpression impaired neither twitch nor tetanic tension in the extensor digitorum longus (EDL) muscle. Furthermore, EDL fatigue response was not altered. Taken together, we have developed a novel AAV vector to enhance catalase expression. Lack of apparent toxicity in normal muscle strongly supports further exploration of this vector to reduce oxidative stress–induced muscle damage. Muscle Nerve, 2007
Dynamic magnetic resonance imaging for grading pelvic organ prolapse according to the international continence society classification: Which line should be used?
Authors: Fauconnier Arnaud , Zareski Elise , Abichedid Joseph , Bader Georges , Falissard Bruno , Fritel Xavier 
Published: August 2007

AbstractAimsTo assess and compare the reliability of dynamic MRI to quantify pelvic organ prolapse (POP) according to the International Continence Society (ICS) using two different reference lines, and to determine which line gives the best concordance with clinical examination.MethodsForty‐seven patients with genital prolapse underwent physical examination and dynamic MRI. Five nulliparous, symptom‐free female volunteers underwent dynamic MRI as control subjects. Two distinct observers performed the MRI measurements of POP according to the ICS using two distinct reference lines: the mid‐pubic line and a new one, the perineal line that provides a better match with the hymen plane. Measurements were repeated twice according to each line. The intra‐class coefficient was used to estimate intra‐observer and inter‐observer reliability; the Altman and Bland plot was used to assess the agreement between MRI and clinical measurements.ResultsThe intra‐observer and inter‐observer reliability of MRI measurements were in general excellent. Intra‐class coefficients were better for the mid‐pubic line than the perineal line. Although the MRI measurements correlate significantly with the physical measurements, the Altman and Bland plot shows an unacceptable magnitude of discrepancy between clinical and MRI examinations.ConclusionsAlthough dynamic MRI shows excellent inter‐ and intra‐observer reliability, its agreement with clinical examination is poor whatever the line used. Neurourol. Urodynam. 27:191–197, 2008. © 2007 Wiley‐Liss, Inc.
Demonstration of intrinsic innervation of the guinea pig upper urinary tract using whole‐mount preparation
Authors: Rolle Udo , Brylla Elke , Tillig Bernd , Chertin Boris , Cascio Salvatore , Puri Prem 
Published: August 2007

AbstractAimsThe morphology and functional importance of the autonomic nervous system in the upper urinary tract is still not completely understood. Previous histological studies investigating the innervation of the urinary tract have mainly used conventional sections in which the three‐dimensional structure of the intramural innervation is difficult to achieve. In contrast, the whole‐mount preparation technique is a suitable method for visualizing the distribution of the mesh‐like neuronal networks within the urinary tract.MethodsThe distribution and regional variation of neurofilament (NF), tyrosine hydroxylase (TH), choline acetyltransferase (ChAT), and substance P‐immunoreactive (SP‐IR) neurons, as well as acetylcholinesterase (AChE) and nicotinamide adenine dinucleotide phosphate‐diaphorase (NADPH‐d)‐positive neurons were investigated using whole‐mount preparations of the guinea pig upper urinary tract.ResultsTwo distinct nervous plexuses were detected within the muscle layers containing NF, TH, ChAT, and SP‐IR nerves. AChE‐positive nerves were seen in all layers. Only moderate NADPH‐d‐positive innervation was found. Renal pelvis, upper and lower part of the ureter showed an overall increased innervation compared to the middle portion of the ureter. Ganglia were found at the pelviureteric border displaying NF and TH immunoreactivity.ConclusionThe whole‐mount preparation technique provides an elegant method for assessing the three‐dimensional architecture of ureteral innervation. The guinea pig upper urinary tract is richly supplied with adrenergic, cholinergic, nitrergic, and sensory nerves which suggest that the autonomous nervous system plays an important role in controlling ureteral motility and blood flow. Neurourol. Urodynam. 27:341–347, 2008. © 2007 Wiley‐Liss, Inc.
A numerical study of the accuracy and stability of symmetric and asymmetric RBF collocation methods for hyperbolic PDEs
Authors: Sarra Scott A. 
Published: August 2007

AbstractDifferentiation matrices associated with radial basis function (RBF) collocation methods often have eigenvalues with positive real parts of significant magnitude. This prevents the use of the methods for time‐dependent problems, particulary if explicit time integration schemes are employed. In this work, accuracy and eigenvalue stability of symmetric and asymmetric RBF collocation methods are numerically explored for some model hyperbolic initial boundary value problems in one and two dimensions. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2008
Relief device sizing for ethylene decompositions—high pressure polyethylene industry
Authors: Shannon David I 
Published: August 2007

AbstractThis paper discusses revisions to a method previously used for sizing relief devices (rupture disks) for vessels in high pressure polyethylene processes. The Re‐evaluation was forced by an unexpectedly high peak pressure in a product separator (high pressure separator, HPS) when an ethylene decomposition occurred. A method, based on revised equations for calculating the rate of pressure rise, is presented for determining relief requirements for ethylene decomposition in a confined space. The method applies to both HPSs and polyethylene autoclave reactors. Causes of decompositions and effect of comonomers are also discussed. Simulations for other events at different operating conditions, not shown, indicate a good match for peak pressures. Therefore, the described equations provide a good estimate of ethylene decomposition peak pressures given the initial conditions.Although these methods were derived specifically for ethylene decompositions, the methods could be used for other decompositions. © 2007 American Institute of Chemical Engineers Process Saf Prog 2007
Lessons learned and mitigation options for hurricanes
Authors: (Bob) Bailey James R. , Levitan Marc L. 
Published: August 2007

AbstractThe 2005 hurricane season caused unprecedented levels of damage to coastal communities throughout the Gulf of Mexico. Hurricane Katrina and Hurricane Rita were of particular interest to petrochemical and refining companies, given the impacts they had to their onshore operations. Floodwaters and extreme winds from these two hurricanes damaged numerous types of assets, including tanks, cooling towers, generator buildings, process towers, pumps, controllers, utility poles, and transformers. They also caused prolonged power outages, supply disruptions, and widespread employee dislocations, all major contributors to both property and business interruption losses.This paper will focus on the nature of wind damages sustained by these two events; the history of the design of these facilities in the context of current practices; the likelihood of such events occurring during the operating life of a plant; and options for mitigating future damage. Also discussed are ways to quantify risks in a manner that will enable operators and owners to make informed, cost‐effective decisions regarding mitigation planning and associated reductions in loss exposures. © 2007 American Institute of Chemical Engineers Process Saf Prog 2007
Defects in yttria‐stabilised zirconia: a positron annihilation study
Authors: Cizek J. , Melikhova O. , Kuriplach J. , Prochazka I. , Konstantinova T. E. , Danilenko I. A. 
Published: August 2007

AbstractHigh‐resolution positron lifetime and coincidence Doppler‐broadening measurements on the yttria‐stabilised zirconia compacted nanopowders, differing in phase, stabiliser content and preparation conditions, are reported. The nature of defects observed in these materials is discussed on the basis of available experimental data and their comparison with theoretical calculations. It is concluded that positrons annihilate mainly in vacancy‐like defects at grain boundaries and in larger open‐volume defects associated with triple points. A fraction of positrons annihilating in mesopores of ≈ 2.5 nm diameter was also detected. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Irradiated polymethylmethacrylate studied by positron annihilation spectroscopy
Authors: Mohamed Hamdy F. M. , Abdel‐Hady E. E. , Mohamed Salwa S. 
Published: August 2007

AbstractThe effect of gamma irradiation dose on microscopic structure of polymethylmethacrylate (PMMA) has been studied using positron annihilation lifetime (PAL) and Doppler broadening of annihilation radiation (DBAR) techniques. The measurements were performed at room temperature as a function of the γ‐irradiation doses from 60‐1200 kGy. The observed lifetime spectra were resolved into three components. The size and the fraction of the o‐Ps hole volume were estimated from the positron annihilation parameters. The effect of γ‐irradiation was identified at lower doses to be cross‐linking while at higher doses the chemical degradation of the polymer was observed. Moreover, the distribution of the free volume shifts from a large to small size as the irradiation increases and has very similar Gaussian‐like distribution. The PAL results were confirmed with X‐ray measurement. A correlation between the macroscopic mechanical properties Hv and positron annihilation parameters has been demonstrated. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Gamma irradiation effects on polymethyl methacrylate
Authors: Al‐Qaradawi I. Y. , Abdulmalik D. A. , Madi N. K. , Almaadeed M. 
Published: August 2007

AbstractThe effect of gamma‐irradiation on the structure of polymethyl methacrylate (PMMA) has been investigated. In this study, the PMMA specimens were gamma‐irradiated at doses in the range of 0‐1000 kGy and measured by means of positron annihilation lifetime (PAL) spectroscopy. Irradiation dose dependence of the longest lifetime component (τ3), attributed to ortho‐positronium (o‐Ps) decay, and the intensity of this component (I3) was studied by positron annihilation lifetime spectroscopy (PAL). The two physical quantities were correlated with the size and density of free volume sites in the examined specimens and were compared with the thermal transitions in the material obtained using the DSC technique. It was found that the size and amount of free volume decreases with increasing dose due to irradiation‐enhanced crosslinking. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structure and free volume properties of semi‐crystalline poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) by positron annihilation lifetime analysis
Authors: Cheng Mei‐Ling , Sun Yi‐Ming 
Published: August 2007

AbstractThe effect of thermal history on the structure and free volume of bacterial poly(3‐hydroxybutyrate‐co‐5mol%‐3‐hydroxyvalerate) (PHBV5) membranes, prepared by the compression‐molding method, was investigated. Free volume size, number of free volume holes, and the distribution of free volume in slow‐, rapid‐, and step‐cooled semi‐crystalline PHBV5 membranes were measured by using positron annihilation lifetime spectroscopy (PALS). The lifetime spectra are resolved into four components and the corresponding annihilation mechanisms are addressed. The size of the free volume in the amorphous phase and the lamellar thickness and crystallite size in the crystalline phase of the slow‐cooled membrane were the largest among all kinds of membranes. The results suggest that the crystallization process not only affects the crystalline structure but also has impact on the free volume properties in amorphous phase of the polymers. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study on polymer electrolyte membrane for fuel cells by using AMOC technique
Authors: Honda Yoshihide , Shibahara Yuji , Akiyama Yoko , Kimura Norio , Isoyama Goro , Tagawa Seiichi , Takeda Shin‐ichi , Izumi Yoshinobu , Nishijima Shigehiro 
Published: August 2007

AbstractThe proton conductivity in Polymer Electrolyte Membrane in Fuel Cells (PEMFC) is affected by the size of free spaces and hydrogen bond at the hydrophilic group. These parameters are influenced by the environmental conditions. We tried to correlate annihilation process of positron and proton conductivity by using Age‐Momentum Correlation (AMOC) measurement. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Applications of positron annihilation to polyamide membranes
Authors: Chen Hongmin , Liu Guang , Chakka Lakshmi , Huang Shu‐Hsien , Lee Kueir‐Rarn , Lai Juin‐Yih , Sun Yi‐Ming , Cheng Mei‐Ling , Jean Y. C. 
Published: August 2007

AbstractPositron annihilation spectroscopy (PAS) has been used to study the depth profile (0 ‐ 8 µm) in a membrane system containing a thin layer of polyamide prepared by the interfacial polymerization of triethylenetetraamine (TETA) and trimesoyl chloride (TMC) onto the surface of asymmetric polyacrylnitrile (PAN). Doppler broadening S parameters of annihilation radiation energy spectra show a systematic variation with the doping time of TETA in the membrane preparation process of interfacial polymerization. The layer structures of composite membrane are obtained. A similar variation between S parameters with respect to TETA doping time and permeability but an anti‐correlation between S parameter and selectivity are observed. Future applications of PAS and slow positron beam to membrane technology appear to be promising. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Compression deformed UHMW polyethylene investigated by PALS and WAXS
Authors: Ortega Y. , Monge M. A. , Pareja R. 
Published: August 2007

AbstractPositron lifetime and wide‐angle X‐ray scattering measurements have been performed on ultra high molecular weight polyethylene deformed in uniaxial compression. No changes in the fraction of positronium states have been detected, suggesting that the fraction of free volume remains constant during deformation under the present conditions. The PALS results reveals that compressive deformation under the present conditions does not produced voiding or free volume increase in the amorphous phase of semicrystalline UHMW‐PE. This is opposed to the result found in the tensile deformed material. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Positron lifetime studies on the free volume changes during deformation of rubber‐carbon black composites
Authors: Jobando V. O. , Quarles C. A. 
Published: August 2007

AbstractThe free volume behavior as a function of strain during deformation of natural rubber‐carbon black composites studied by positron annihilation lifetime spectroscopy (PALS) is reported. The lifetime and intensity of the ortho‐positronium (o‐Ps) pick‐off annihilation, which correlate with the average size and the number of holes respectively, were measured as a function of strain. The results show how PALS can detect the changes that occur in polymer composites samples and help explain the effect of carbon black on the properties of the composites when they are deformed under compression. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural heterogeneity in glassy polymeric materials revealed by positron annihilation and other supplementary techniques
Authors: Shantarovich V. P. , Suzuki T. , Ito Y. , Kondo K. , Yu R. S. , Budd P. M. , Yampolskii Yu. P. , Berdonosov S. S. , Eliseev A. A. 
Published: August 2007

AbstractA disagreement between effective sizes of elementary free volumes found from the four component PATFIT analyses of positronium annihilation lifetime spectra and experiments on low temperature sorption for two membrane materials of internal microporosity poly(tri‐methyl‐silyl‐propyne) PTMSP and spiro‐linked benzodioxane polymer PIM‐1 is described and discussed. This disagreement can be minimized essentially using the fifth lifetime component but not the Gaussian distribution of the fourth component. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of MMT content on the microstructure and miscibility for PU/EP IPN nanocomposites by positron
Authors: Zhu Yuchan , Zhou Wei , Wang Junjun , Wang Bo , Kong Lingmei , Jia Qingming 
Published: August 2007

AbstractEffects of montmorillonite (MMT) content on the free volume hole and miscibility were first investigated for polyurethane/epoxy resin (PU/EP) interpenetrating polymer network (IPN) nanocomposites by positron annihilation lifetime spectroscopy (PALS), X‐ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). An exfoliated (IPN/MMT1), a coexistence of exfoliated and intercalated (IPN/MMT3), and an intercalated (IPN/MMT5) structures were confirmed by XRD. Influences of two kinds of hydrogen bonding interactions including both between carbonyl group and N‐H group, and the other between urethane group and silicate layers have been discussed. PALS results reveal that the size of the free volume holes decreases after the MMT loaded due to the increase of chain packing efficiency. The large difference between IPN/MMT1 and IPN/MMT5 in the free volume distribution was observed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Detection of bicontinuous phase in some reverse micellar systems by positron lifetime spectroscopy
Authors: Yadav Ramesh , Chandramani Singh K. , Choudhary S. R. , Jain P. C. 
Published: August 2007

AbstractPositron lifetime measurements have been made in some reverse micellar systems of cetyl tri methyl ammonium bromide (CTAB)/hexanol and tetra‐decyl‐tri‐methyl‐ ammonium‐bromide (TTAB)/pentanol by adding increasing amount of water in each system. For both the systems, the dependence of positron lifetime parameters on water concentration indicates the existence of bicontinuous phase in so called single reverse micellar phase. The results of this investigation have been presented in this paper. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)