bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computed Tomography Findings in Xanthogranulomatous Pyelonephritis
Authors: Rajesh Arumugam , Jakanani George , Mayer Nick , Mulcahy Kevin 
Published: August 2011

Background:
Xanthogranulomatous pyelonephritis (XGN) is an uncommon condition characterized by chronic suppurative renal inflammation that leads to progressive parenchymal destruction.

Purpose:
To review the computed tomography (CT) findings of patients diagnosed with XGN.

Materials and Methods:
A retrospective review of CT findings in patients with histologically proven XGN was carried out.

Results:
Thirteen CT examinations of 11 patients were analyzed. Renal enlargement was demonstrable on the affected side in all patients. Nine patients (82%) had multiple dilated calyces and abnormal parenchyma. Six patients (55%) had a renal pelvis or upper ureteric calculus causing obstruction. Three patients (27%) had focal fat deposits identifiable within the inflamed renal parenchyma. Two patients had renal abscesses. Ten patients (91%) had extrarenal extension of the inflammatory changes. Three patients (27%) demonstrated extensive retroperitoneal inflammation.

Conclusion:
Unilateral renal enlargement and inflammation were the most consistent findings of XGN on CT. Perinephric inflammation and collections or abscess should also alert the radiologist to the possibility of this diagnosis.
Electrical and Photo‐Induced Degradation of ZnO Layers in Organic Photovoltaics
Authors: Manor Assaf , Katz Eugene A. , Tromholt Thomas , Krebs Frederik C. 
Published: August 2011

AbstractWe present the case of degradation of organic solar cells by sunlight concentrated to a moderate level (∼4 suns). This concentration level is not enough for sufficient acceleration of the photobleaching or trap‐generation in the photoactive layer and therefore such short treatment (100 minutes) does not affect the short‐circuit current of the device. However, a significant degradation of VOC and FF has been recorded by measurements of the cell current‐voltage curves with a variation of light intensity, for the devices before and after the treatment. The same degradation was found to occur after short application of forward voltage biases in the dark. This kind of degradation is found to be repairable, and could even be prevented by simple electrical treatment (short pulses of the reverse bias). Moreover, even the fresh cells can be improved by the same process. Generation and degeneration of shunts in ZnO hole‐blocking layer as underlying physical mechanisms for the cell degradation and restoration, respectively, can explain the results.
Direct numerical simulations of aggregation of monosized spherical particles in homogeneous isotropic turbulence
Authors: Derksen J. J. 
Published: August 2011

AbstractDirect numerical simulations of turbulent solid–liquid suspensions have been performed. The liquid is Newtonian, and the particles are identical spheres. The spheres have a tendency to aggregate since they are attracted to one another as a result of a square‐well potential. The size of the particles is typically larger than the Kolmogorov scale, albeit of the same order of magnitude. In such situations, the particle dynamics (including the aggregation process), and turbulence strongly interact which explains the need for direct simulations. The lattice‐Boltzmann method combined with an immersed boundary method for representing the no‐slip conditions at the spherical solid–liquid interfaces was used. The results show that the aggregate size distributions depend on both the strength of particle–particle interactions and the intensity of the turbulence. © 2011 American Institute of Chemical Engineers AIChE J, 58: 2589–2600, 2012
Sensitivity analysis of a proposed model mechanism for newly created glucose‐6‐oxidases
Authors: Moon Tae Seok , Nielsen David R. , Prather Kristala L. Jones 
Published: August 2011

AbstractParametric sensitivity analysis of a proposed model mechanism can serve as a valuable diagnostic for studying the fundamental characteristics of an enzymatic reaction. As the first step toward understanding the kinetics of a series of newly engineered glucose‐6‐oxidases, the activity of which has never been found in nature, we have proposed a mechanistic kinetic model and performed a parametric sensitivity analysis. The mechanism of our model consists of two enzyme conformations, namely “less active” and “more active,” and is shown to be consistent with experimental observations of prolonged periods of enzyme induction. The extended lag phase phenomenon was found to be well described mechanistically by a slow rate of interconversion between the two enzyme conformations (relative to the rate of product formation), and this prediction was further supported by our experimental results. The proposed enzymatic model will serve as a blueprint with which to better understand the mechanistic behavior of newly generated glucose‐6‐oxidases. © 2011 American Institute of Chemical Engineers AIChE J, 58: 2303–2308, 2012
The coexistence of chronic lymphocytic leukemia and myeloproliperative neoplasms: A retrospective multicentric GIMEMA experience
Authors: Laurenti Luca , Tarnani Michela , Nichele Ilaria , Ciolli Stefania , Cortelezzi Agostino , Forconi Francesco , Rossi Davide , Mauro Francesca Romana , D'Arena Giovanni , Del Poeta Giovanni , Montanaro Marco , Morabito Fortunato , Musolino Caterina , Callea Vincenzo , Falchi Lorenzo , Tedeschi Alessandra , Ambrosetti Achille , Gaidano Gianluca , Leone Giuseppe , Foà Robin 
Published: August 2011

AbstractAlthough the coexistence of chronic lymphocytic leukemia (CLL) and myeloproliferative neoplasms (MPN) has been sporadically reported in the literature, no systematic studies on this disease association are available. We retrospectively analyzed 46 patients affected by CLL/MPN referred by 15 Italian GIMEMA centers. The aim of this retrospective multicenter study was to define the following: clinico‐biological characteristics, possible familiarity, clinical course of both diseases, and influence of MPN chemotherapy on the course of CLL. Among 46 patients, 30 patients were males, 16 patients were females; median age was 71 years. Only one case had familiar CLL. Myeloproliferative disorders consisted of essential thrombocytemia in 18 cases, polycythemia vera in 10 cases, chronic myeloid leukemia in 9 cases, primary myelofibrosis in 6 cases, and MPN/myelodysplastic syndrome in 3 cases. The lymphoproliferative disorder was diagnosed as monoclonal B‐cell lymphocytosis in 8 patients and as Binet Stage A CLL in 38 patients. After a median follow‐up of 49 months, 9 patients experienced progressive CLL and only 6 patients required treatment after a median of 57.5 months. The biological profile confirmed a subset of low‐risk CLL. Twenty patients received chemotherapy for MPN without influence on the course of CLL: lymphocyte counts remained unchanged after 3, 6, and 12 months of treatment. This series is the largest so far reported in literature. The diagnosis of concomitant CLL/MPN is a rare event and lymphoproliferative disorders present a clinical indolent course with a low‐risk biological profile. MPN therapy does not interfere with the prognosis of patients with CLL. Am. J. Hematol. 2011. © 2011 Wiley‐Liss, Inc.
Preparation and characterization of polyimide and polyethersulfone blend membrane for gas separation
Authors: Madaeni S. S. , Mohammadi Nooripour R. , Vatanpour V. 
Published: August 2011

ABSTRACTPolyimides (PI) have been studied as the basic materials for preparing gas separation membranes attributable to their high gas selectivity. This paper deals with the preparation and characterization of blended polyimide membranes with polyethersulfone (PES) to study separation of ethylene from nitrogen gas at different feed pressures. For improving performance of PI membranes, two procedures were used. First, using polymeric additives such as polyvinylidene fluoride (PVDF) and PES in low content and second, blending of PI casting solution with high amount of PES. Infrared spectroscopy and scanning electron microscopy (SEM) images were employed to characterize the membranes. Pyromellitic dianhydride‐co‐4, 4′‐oxy dianiline (PMDA/ODA) polyimide membranes was synthesized using polyamic acid (PAA) as precursor materials. The ideal selectivity of 100% (ethylene permeation only) was achieved at 1 bar using PMDA/ODA polyimide membranes containing 1 wt% PVDF. Addition of PES did not have any significant influence on ideal selectivity of the prepared membranes. PES‐(PMDA/ODA) polyamic acid blend membranes were prepared using different blending ratios of PES (25 wt%) and PAA (15 wt%). The blending ratio of casting solutions of PES/PAA solutions exhibited a main influence on the ideal selectivity. The ideal selectivity of 2.9 for ethylene was achieved at 3 bar using blend membranes with 0.5 wt% PAA solution. PES‐PMDA/ODA polyimide membranes were also prepared from blend casting solutions by thermal imidization. Immiscible blend membranes were obtained at different blending ratios of the casting solutions with high gas permeance and poor selectivity. © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.
Influence of plasma surface treatments on kink band formation in PBO fibers during compression
Authors: Lorenzo‐Villafranca Eduardo , Tamargo‐Martínez Katia , Molina‐Aldareguia Jon M. , González Carlos , Martínez‐Alonso Amelia , Tascón Juan M. D. , Gracia Mercedes , Llorca Javier 
Published: August 2011

AbstractThe effect of nitrogen and oxygen plasma surface treatments on the compressive strength of PBO fibers has been studied. To this end, the nucleation and propagation of compression‐induced kink bands was carefully monitored by means of in situ bending tests inside a scanning electron microscope. The micromechanisms of deformation were identical irrespective of fiber surface condition (either as‐received or modified by plasma) but the critical stress necessary to induce irreversible damage in compression in the nitrogen‐plasma treated fibers was 40% higher than in the as‐received fibers. This improvement occurred without any reduction in the fiber tensile properties. The source of this behavior is discussed in the light of the morphological and chemical changes induced by the plasma treatments on the fiber surface, as studied by AFM and XPS. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Characterization and physical properties investigation of conducting polypyrrole/TiO2 nanocomposites prepared through a one‐step “in situ” polymerization method
Authors: Babazadeh Mirzaagha , Rezazad Gohari Faezeh , Olad Ali 
Published: August 2011

AbstractNowadays, nanocomposites are a special class of materials having unique physical properties and wide application potential in diverse areas. The present research work describes an efficient method for synthesis of a series of polypyrrole/titanium dioxide (PPy/TiO2) nanocomposites with different TiO2 ratios. These nanocomposites were prepared by one‐step in situ deposition oxidative polymerization of pyrrole hydrochloride using ferric chloride (FeCl3) as an oxidant in the presence of ultra fine grade powder of anatase TiO2 nanoparticles cooled in an ice bath. The obtained nanocomposites were characterized by Fourier‐transform infrared (FTIR), thermogravimetric analysis (TGA), X‐ray diffraction (XRD), and scanning electron microscope (SEM) techniques. The obtained results showed that TiO2 nanoparticles have been encapsulated by PPy with a strong effect on the morphology of PPy/TiO2 nanocomposites. Also, the synthesized PPy/TiO2 nanocomposites had higher thermal stability than that of pure PPy. The investigation of electrical conductivity of nanocomposites by four‐point probe instrument showed that the conductivity of nanocomposite at low TiO2 content is much higher than of neat PPy, while with the increasing contents of TiO2, the conductivity decreases. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Novel high‐performance wave‐transparent aluminum phosphate/cyanate ester composites
Authors: Sun Zhouqiang , Huang Pingzhen , Gu Aijuan , Liang Guozheng , Yuan Li , Dai Shankai 
Published: August 2011

AbstractAdvanced wave‐transparent composites are the key materials for many cutting‐edge industries including aviation and aerospace, which should have outstanding heat resistance, low dielectric constant and loss as well as good mechanical properties. A novel kind of high‐performance wave‐transparent composites based on surface‐modified aluminum phosphate AlPO4(KH‐550) and cyanate ester (CE) was first developed. The dielectric and dynamic mechanical properties of AlPO4(KH‐550)/CE composites were investigated intensively. Results show that AlPO4(KH‐550)/CE composites have decreased dielectric loss and higher storage moduli than pure CE resin; in addition, the composites with suitable AlPO4(KH‐550) concentration remain the outstanding thermal property and low dielectric constant of pure CE resin. The reasons attributing to these results are discussed from the effects of AlPO4(KH‐550) on the key aspects such as morphology, curing mechanism, and interfacial adhesion of composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effects of lithium perchlorate on poly(ethylene oxide) spherulite morphology and spherulite growth kinetics
Authors: Zhang Yao , Li Jingqing , Huo Hong , Jiang Shichun 
Published: August 2011

AbstractEffects of lithium perchlorate (LiClO4) on the crystallization behaviors of poly(ethylene oxide) (PEO) were investigated by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and polarized optical microscopy (POM) in PEO/LiClO4 system. DSC results indicate that there are nucleation effects of LiClO4 on the crystallization of PEO. But, on the other hand, the coordination of lithium ion with the oxygen ether atoms of PEO can obviously reduce the crystallinity and spherulite growth rate of PEO. This contrary effect of LiClO4 on the crystallization of PEO in PEO/LiClO4 complexes system was analyzed and discussed in detail. The Laurizen–Hoffman theory was used to describe the Li‐coordinated crystallization kinetics of PEO spherulite. It showed that the nucleation constant (Kg) and folding surface free energy (σe) decreased with increasing LiClO4 contents, and the energy necessary for the transport of segments across the liquid–solid interface (ΔE) increased on increasing the contents of LiClO4. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Using a polymer‐supported azide ion in [2+3] cycloaddition reaction of azide ion with nitriles
Authors: Karimi Zarchi Mohammad Ali , Nazem Fatemeh. 
Published: August 2011

AbstractThe [2+3] cycloaddition between various nitriles and crosslinked poly(4‐vinylpyridine) supported azide ion proceeds smoothly in the presence of ammonium bromide or ammonium chloride in N,N‐dimethyl formamide, to give the corresponding 5‐substituted‐1H‐tetrazoles in good to high yields. Conventional heating was used to promote reaction. It was found that using nitriles with electron‐withdrawing groups result in bout higher yields and lower reaction times. The present procedure offers advantages, such as shorter reaction time, and simple workup. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effects of material and treatment parameters on noise‐control performance of compressed three‐layered multifiber needle‐punched nonwovens
Authors: Yilmaz Nazire Deniz , Michielsen Stephen , Banks‐Lee Pamela , Powell Nancy B. 
Published: August 2011

AbstractThe effects of material and treatment parameters on airflow resistivity and normal‐incidence sound absorption coefficient (NAC) of compressed three‐layer nonwoven composites have been studied. Material parameters included fiber size and porosity, and treatment factors included applied pressure and duration of compression. Fibers used included poly(lactic acid) (PLA), polypropylene (PP), glassfiber, and hemp. Three‐layered nonwoven composites were classified based on material content and fiber blend. LHL and PGP were sandwiched structures consisting of PLA/Hemp/PLA and PP/glassfiber/PP layers, respectively. PGI consisted of three layers of an intimate blend of PP and glassfiber. Statistical models were developed to predict air flow resistivity from material parameters and the change in air flow resistivity from compression parameters. Independent variables in the first model were porosity and fiber size and, in the latter model, were compressibility, pressure, and initial material parameters. An increase in air flow resistivity was found with increased compression. No significant effect of compression duration was detected. Two additional statistical models were developed for the prediction of sound absorption coefficient based on material and treatment parameters. The independent variables of the first model were air flow resistivity, thickness, and frequency, and those of the second model were compressibility, initial thickness, and initial density of the composite, diameter and density of the fiber, compression pressure, and frequency. A decrease in sound absorption coefficient was detected with increasing compression, while no effect of duration was detected. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Isothermal rheokinetic study of a precured resol resin beyond gelation by torsion
Authors: Domínguez J. C. , Oliet M. , Alonso M. V. , Rojo E. , Rodríguez F. 
Published: August 2011

AbstractThe rheokinetics of the curing process of a resol resin was studied through isothermal analysis. The resin was subjected to a curing pretreatment until gelation was reached. Rectangular torsion was chosen as the appropriate strain form to carry out the study of the resin's curing kinetics, because the viscoelastic behavior of the material was closer to an ideal solid than to a Newtonian fluid. Seven operating temperatures were selected for analysis (80–110°C). The Arrhenius and Kiuna rheokinetic models were applied to the resin's complex viscosity (η*) evolution during the crosslinking of polymer. The resol resin had curing activation energies of 62.6 and 65.8 kJ/mol when the Arrhenius model was applied in four‐ and six‐parameter forms, respectively. The Kiuna model was proposed to fit the nonlinear viscosity region found at the highest temperatures. This model was suitable to predict changes in the resin's complex viscosity, obtaining a curing activation energy of 69.5 kJ/mol for the resin. In addition, the evolution of the degree of mechanical curing was obtained from the elastic modulus, rather than from the more common DSC technique. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Novel phenolic resins with improved mechanical and toughness properties
Authors: Cardona Francisco , Kin‐Tak Alan Lau , Fedrigo Jessica 
Published: August 2011

AbstractNovel phenolic type of thermoset resins were synthesized, and their mechanical and toughness properties were evaluated. Phenol Formaldehyde (PF) phenolic resins were modified to broaden their applications for modern composite structures. A first modification consisted of copolymerization of Phenol with Cardanol during the synthesis of resole phenolic (CPF) resins. The modified phenolic resins (CPF) were prepared at various molar ratios of total Phenol to Formaldehyde (F : P ratio) and with different weight ratios of Phenol to Cardanol. CPF resins with a maximum content of 40 wt % of Cardanol were synthesized and used. The CPF resins were applied as a plasticizer and toughening agent to the base PF resins. Both resins (CPF/PF) were mixed in different proportions, and their thermal and mechanical properties were then established. A full miscibility of the two resins was observed with the formation of a single‐phase system. An increase in the content of Cardanol resulted in a proportional increase of the flexural strength and fracture toughness together with a decrease of the flexural modulus of the cured CPF/PF resins. Further increased plasticizing and toughening effect was also observed by the blending of the CPF resins with propylene glycol. The higher toughness and flexibility effect of the CPF resins was obtained with a F : P molar ratio equal to 1.25 and with a Cardanol content of 40% (w/w). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Modification of cellulosic fabrics to impart flame retardancy properties
Authors: Waly A. I. , Abou Elmaaty T. M. , Abd El‐Shakour S. A. 
Published: August 2011

AbstractGraft copolymerization of dimethylaminoethyl methacrylate (DMAEMA) onto cotton‐cellulose in the fabric form was carried out using a cellulose‐thiocarbonate‐ammonium persulphate redox initiation system. Effects of the concentration of the monomer, effect of liquor ratio, grafting time, and temperature were studied. The results point out the following important aspects of flame retardation of cellulose fabrics. (1) The graft polymerization of DMAEMA can improve the flame retardant properties of cellulose fabrics. (2) Tertiary amine grafted to cellulosic fabrics is suitable for nitrogen compounds that can effectively operate as synergists. The flame retardant properties of the poly‐DMAEMA‐ grafted‐phosphorylated cellulosic materials were found to be excellent even after 25 dry clean washings. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Investigation of tensile properties and dyeing behavior of various polypropylene/amine modifier blends
Authors: Asiaban Saeed , Moradian Siamak 
Published: August 2011

AbstractPolypropylene is utilized in manifold applications due to its unique properties. However, its use has been limited in the textile industry because conventional dyestuffs have no affinity for this polymer. Amine modifiers, generally improve the dye‐ability of polypropylene. Polyamide 6 (PA6) is a traditional amine modifier which improves the dyeing ability of polypropylene with disperse dyes. In this investigation, polyetheramine (PEA) is introduced as a novel amine modifier which improves the dye‐ability of polypropylene with disperse and acid dyestuffs. To this end, the dyeing behavior as well as possible impairments of tensile properties of PEA modified polypropylene were studied and compared to PA6 modified polypropylene. As with the PA6 containing blends, the tensile properties of the incompatible PP/PEA blends decreased due to weak interfacial adhesions between the components of the blends. However, the incorporation of a compatibilizer into such blends led to better dispersions of modifiers in the matrix as well as formation of amide or imide linkages which in turn reincreased the tensile properties almost to their initial values. Both PEA and PA6 modifiers improved the disperse dye uptake of the blends. However, Only Jeffamine ED‐2003 (i.e., PEA) was capable of enhance the acid dye uptake of modified polypropylene. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Fatigue life prediction for circular rubber bearings subjected to cyclic compression
Authors: Chou Hsoung‐Wei , Huang Jong‐Shin 
Published: August 2011

AbstractThe fatigue life of circular rubber bearings under cyclic compression is theoretically and numerically analyzed based on a previously proposed fatigue failure mechanism. The energy release rate at any point in circular rubber bearings under cyclic compression, which depends on the cracking energy density and crack length along the predicted crack propagation path, is derived first theoretically. Then, the corresponding fatigue crack growth rate and fatigue life are determined numerically by introducing the fatigue parameters of three different rubber compounds before and after suffering from thermal aging. Meanwhile, the effects of intrinsic flaw size and maximum compressive stress on the fatigue life of circular rubber bearings are also investigated. It is found that the enlargement in the Regime 1 range of the crack growth rate of rubber increases the fatigue resistance of circular rubber bearings. Therefore, the effects of the mechanical properties, intrinsic flaw size, threshold value, and maximum cyclic compressive stress on fatigue life are significant and should be taken into account in designing rubber bearings. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012