bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal Properties of PMMA on Silica Using Temperature‐Modulated Differential Scanning Calorimetry
Authors: Khatiwada Bal K. , Hetayothin Boonta , Blum Frank D. 
Published: May 2013

SummaryThe behavior of an amorphous polymer, poly(methyl methacrylate) (PMMA), adsorbed on silica was studied using temperature‐modulated differential scanning calorimetry (TMDSC). A two‐component model, based on loosely‐bound polymer with a glass transition temperature (Tg) (similar to that of the bulk polymer) and a tightly‐bound polymer (with a Tg higher than that of the loosely‐bound polymer) was used to interpret the thermograms. Increased sensitivity allowed the two transitions in the thermograms to be quantified much more accurately than in previous work. Linear regression analysis of the ratio of the area under two transitions with composition yielded the amount of tightly bound polymer, m″B = 1.21 +/− 0.21 mg PMMA/m2silica. Two methods of analyzing the thermograms, fitting with a Gaussian‐Lorentzian (GL) cross distribution function and perpendicular drop (PD) method, yielded similar results for the amount of tightly‐bound polymer on the surfaces with the GL method having a statistically better fit to the model. The ratio of heat capacity increments of loosely bound and tightly bound polymer, ΔCpA/ΔCpB, around the glass transition, indicated the relative mobility of the two components. It was found that the ΔCpA was aboutthree times as large as that of ΔCpB suggesting that the tightly bound polymer had a much smaller change in mobility through glass transition region.
Preparation and Characterization of Zr (IV) Doped Polyaniline for Supercapacitor Application
Authors: Giri Soumen , Ghosh Debasis , Mandal Avinandan , Das Chapal Kumar 
Published: May 2013

SummaryIn the present paper, we have reported the in‐situ chemical synthesis and characterizations of polyaniline with both HCl and Zirconium (IV). The polyaniline was synthesized by electrochemical oxidative polymerization of aniline monomer using ammonium peroxodisulphate as oxidizing agent. The doped PANI was charecterized by Ultraviolet‐Visible (UV‐Visible), Fourier transfrom infrared (FT‐IR), Thermo gravimetric analysis (TGA), Field emission scanning electon microscopy (FESEM) and Transmission electron microscopy (TEM) analysis. FESEM and TEM study showed that the morphology of PANI changed after doping with Zirconium salt. All electrochemical charcterizations were peforrmed by conventional three electrode system where glassy carbon electrode, platinium wire and stanadard calomel electrode (SCE) were used as working electrode, counter electrode and reference electrode, respectively. The cyclic voltammtry study(CV), electrochemical impedance spectroscopy(EIS)study and charge discharge test (CCD) of Zr doped PANI showed better performance and higher specific capacitance of 323 F/g compareed to HCl doped PANI.
Micromechanical Studies of Styrenic Block Copolymer Blends Based Nanocomposites
Authors: Henning Sven , Adhikari Rameshwar , Borreck Sven , Buschnakowski Matthias , Michler Goerg H. 
Published: May 2013

SummaryIn this work, using different microscopic techniques, and tensile testing, we investigate the micro‐deformation processes in the blends and nanocomposites based on a highly asymmetric star shaped polystyrene/polybutadiene block copolymer. As one of the blends and composites components, we use general purpose polystyrene (GPPS) and organophilic modified boehmite nanoparticles, respectively. The emphasis has been put on the analysis of the impact of morphology on the micromechanical behaviour of the blends. After mixing with standard polystyrene, these copolymers form typical droplet morphologies. The incorporation of boehmite nanofiller with different types of surfactants into the binary blends was found to affect the micromechanical properties in various ways, the most optimum morphology for the enhancement of the toughness being the finest dispersion of the spherical nanoparticles less than 50 nm in diameter which initiated intense plastic deformation of the blend.
Conical tube hydro‐forming design of automotive instrument panel beams using computer aided engineering
Authors: Kim K. J. , Kim K. , Kang Y. , Park J.‐H. 
Published: May 2013

AbstractThe hydroforming technology has been spreaded dramatically in automotive industry during the last 10 years. The advantages of hydroforming (less thinning, a more efficient manufacturing process, etc.) can, for instance, be combined with the high strength of extra high strength steels, which are usually less formable, to produce structural automotive components, which exhibit lower weight and improved service performance. Design and production of tubular components require knowledge about the tube material and forming behavior during hydroforming and how the hydroforming operation itself should be controlled. These issues are studied analytically in the present paper. In this study, the whole process of automotive IP (instrument panel) beam parts development by conical tube hydroforming using a steel material having a tensile strength of 370 MPa grade is presented. At the part design stage, it requires feasibility study and process design aided by CAE (computer aided engineering) to confirm the hydroformability in details. Effects of parameters such as geometry shape in automotive IP parts on the hydroforming process were carefully investigated. The overall feasibility of hydroformable IP parts could be examined by cross sectional analyses. Moreover, it is essential to ensure the formability of the tube material on every forming step such as pre‐bending, preforming and hydroforming. In addition, all the components of the prototyping tool are designed and the interference with the press is examined from the point of geometry and thinning.
Strength capacity of simply supported circular concrete slab
Authors: Matešan D. , Radnić J. , Grgić N. , Baloević G. 
Published: May 2013

AbstractThe results of an experimentally tested simply supported circular concrete slab were presented first. The slab was loaded with a point load at mid‐span. The effect of four different reinforcement arrangements on its limit strength capacity and deflection was analyzed. A previously developed numerical model of the authors for analysis of ordinary reinforced and prestressed concrete slabs and shells was tested based on the obtained experimental results. Then, the limit strength capacity of the circular concrete slab of a cement silo, loaded with a uniform load, was numerically analyzed. It was concluded that the limit strength capacity and deflection of a simply supported circular concrete slab depends significantly on its reinforcement arrangement.
On the fragility of fiberglass reinforced polyester pipe in contact with hydrofluoric acid (HF)
Authors: Leta F. R. , Mainier F. B. 
Published: May 2013

AbstractThe use of fiberglass reinforced plastics (FPR), manufactured in polyester or epoxy, has been explored by a number of petroleum offshore operators as an alternative to steel, principally due to the resistance to corrosion of these materials. In addition, their relative light weight facilitates handling and installation that is particularly beneficial for retrofit applications. The structural integrity of traditional FRP components in corrosive environments is usually dependent on the integrity of a corrosion‐resistant barrier, such as a resin‐rich layer containing corrosion resistant glass fibers. In this paper, the case study investigated by the authors provide the example of a failure that can occur in acidizing operations with mixtures of hydrofluoric acid and hydrochloric acid. Therefore, fiberglass is susceptible to damage modes such as resin cracking, fiber breakage, delamination and chemical corrosion. The paper illustrates the attack of hydrofluoric acid (HF) that penetrates in the porosities or cracks and attacks the fiberglass (SiO2), resulting, consequently, in the loss of the mechanical properties of the material.
Spots and stripes in nonlinear Schrödinger‐type equations with nearly one‐dimensional potentials
Authors: Haragus Mariana , Kapitula Todd 
Published: May 2013

AbstractWe consider the existence of spots and stripes for a class of nonlinear Schrödinger‐type equations in the presence of nearly one‐dimensional localized potentials. Under suitable assumptions on the potential, we construct various types of waves that are localized in the direction of the potential and have single‐ or multihump, or periodic profile in the perpendicular direction. The analysis relies upon a spatial dynamics formulation of the existence problem, together with a center manifold reduction. This reduction procedure allows these waves to be realized as unipulse or multipulse homoclinic orbits, or periodic orbits in a reduced system of ordinary differential equations. Copyright © 2013 John Wiley & Sons, Ltd.
B0‐informed variable density trajectory design for enhanced correction of off‐resonance effects in parallel transmission
Authors: Schneider Rainer , Ritter Dieter , Haueisen Jens , Pfeuffer Josef 
Published: May 2013

PurposeTo improve B1 and B0 inhomogeneity mitigation performance of spatially selective radio‐frequency (RF) pulses in parallel transmission while decreasing RF pulse power. Further enhancement of off‐resonance correction for rectilinear spoke‐trajectory‐based RF pulses with known residual geometric distortions after optimization.MethodsThe appropriate definition of the target magnetization pattern is discussed regarding the maximum physical excitation resolution. Furthermore, a novel variable‐density trajectory design is introduced, which subsamples accrued B0 phase error elevations in k‐space. A simulation study (echo‐planar and spiral 2DRF) at different off‐resonance levels and pulse acceleration factors was pursued using data from a whole‐body 2‐channel parallel transmit 3T MRI system. The new trajectory design for echo‐planar 2DRF was validated in human in‐vivo experiments.ResultsProper target pattern definition can require spatial filtering, such that RF pulse optimization is prevented from lower excitation performance with significant higher RF power level. The new trajectory design proposed can considerably improve off‐resonance compensation, while further reducing the RF power, e.g., 43% less RMSE with 79% less RF power for spoke based pulses.ConclusionThe proposed methods offer significant improvements of the excitation performance (homogeneity and acceleration), while significantly decreasing the RF power. Furthermore, single‐channel transmit RF pulse performance can be similarly improved. Magn Reson Med 71:1381–1393, 2014. © 2013 Wiley Periodicals, Inc.
Resolving futile glucose cycling and glycogenolytic contributions to plasma glucose levels following a glucose load
Authors: Nunes Patricia M. , Jarak Ivana , Heerschap Arend , Jones John G. 
Published: May 2013

PurposeAfter a glucose load, futile glucose/glucose‐6‐phosphate (G6P) cycling (FGC) generates [2‐2H]glucose from 2H2O thereby mimicking a paradoxical glycogenolytic contribution to plasma glucose levels. Contributions of load and G6P derived from gluconeogenesis, FGC, and glycogenolysis to plasma glucose levels need resolution. A simple methodology is proposed integrating the administration of 2H2O with a glucose load containing [1‐2H, 1‐13C]glucose and [2‐2H, 2‐13C]glucose.MethodsMice fasted for 6 (n = 7) or 24 h (n = 5) were intraperitoneally injected with 2 mg/g 10% enriched glucose in 35 µL/g 2H2O. Plasma glucose enrichment was analyzed by 2H NMR after 30 min.ResultsFor 6‐h fasted mice, 12.3 ± 1.5% of plasma glucose was pre‐existing, 44.3 ± 2.7% was load derived, and 43.4 ± 1.8% G6P derived. G6P origins were 26.0 ± 2.0% gluconeogenesis, 10.9 ± 2.6% FGC, and 6.5 ± 3.4% glycogenolysis. For 24‐h fasted mice, 18.2 ± 8.5% was pre‐existing, 41.1 ± 5.0 % was load derived, and 40.8 ± 4.3% G6P derived. G6P origins were 27.1 ± 3.3% gluconeogenesis, 13.1 ± 2.8% FGC, and 0.6 ± 2.4% glycogenolysis.ConclusionAfter a glucose load, glycogenolytic contribution to plasma glucose was negligible, whereas FGC was significant for both 6‐ and 24‐h fasted mice. Magn Reson Med 71:1368–1373, 2014. © 2013 Wiley Periodicals, Inc.
Value of short exercise and short exercise with cooling tests in the diagnosis of myotonic dystrophies (DM1 AND DM2)
Authors: Gawel Malgorzata , Szmidt‐Salkowska Elzbieta , Lusakowska Anna , Nojszewska Monika , Sulek Anna , Krysa Wioletta , Rajkiewicz Marta , Seroka Andrzej , Kaminska Anna M. 
Published: May 2013

ABSTRACTIntroduction: Standard electromyography (EMG) is useful in the diagnosis of myotonic dystrophy type 1 (DM1) and type 2 (DM2), but it does not differentiate between them. The aim of this study was to estimate the utility of the short exercise test (SET) and short exercise test with cooling (SETC) in differentiating between DM1 and DM2. Methods: SET and SETC were performed in 32 patients with DM1 (mean age 35.8 ± 12.7 years) and 28 patients with DM2 (mean age 44.5 ± 12.5 years). Results: We observed a significant decline in compound motor action potential (CMAP) amplitude in DM1 with both SET and SETC immediately after effort. In DM2, there was no marked change in CMAP amplitude with either SET or SETC. Conclusions: SET and SETC may serve as useful tools for clinical differentiation between DM1 and DM2, and they may be used as a guide for molecular testing. Muscle Nerve 49: 277–283, 2014
A pilot study of muscle plasma protein changes after exercise
Authors: Dahlqvist Julia R. , Voss Line G. , Lauridsen Thomas , Krag Thomas O. , Vissing John 
Published: May 2013

ABSTRACTIntroduction: Creatine kinase (CK) and myoglobin (Mb) do not possess all good qualities as biomarkers of skeletal muscle damage. We investigated the utility of troponin I (TnI) and telethonin (Tcap) as markers and examined their temporal profiles after skeletal muscle damage. Methods: Plasma profiles were measured before and after exercise in 3 groups: subjects affected by either Becker muscular dystrophy or McArdle disease, and healthy subjects. Results: Mb and TnI appeared early in the blood, and the increase of TnI was only observed in patients with muscle disease. The CK increase was more delayed in plasma. Tcap was not detectable at any time. Conclusions: Our results suggest that TnI is a marker of more severe damage signifying sarcomeric damage, and it could therefore be an important supplement to CK and Mb in clinical practice. Tcap is not useful as a marker for skeletal muscle damage. Muscle Nerve 49: 261–266, 2014
Small fibers, large impact: Quality of life in small‐fiber neuropathy
Authors: Bakkers Mayienne , Faber Catharina G. , Hoeijmakers Janneke G.J. , Lauria Giuseppe , Merkies Ingemar S.J. 
Published: May 2013

ABSTRACTIntroduction: The impact of small‐fiber neuropathy (SFN) on patients' quality of life (QOL) has not been studied extensively. Our aim was to determine the impact of SFN on QOL and examine possible determinants. Methods: We examined a total of 265 patients diagnosed with SFN. The SFN Symptoms Inventory Questionnaire (SFN‐SIQ), the pain Visual Analog Scale (VAS), and the generic SF‐36 Health Survey were assessed. Regression studies were undertaken to evaluate determinants of functioning. Results: SFN patients demonstrated a severe overall reduction in QOL. The biggest deficits were in Role Functioning–Physical, Body Pain, and Physical Component Summary (PCS) scores. VAS scores, changed sweating pattern, dry mouth, and age were the strongest predictors for PCS, explaining 32% of the QOL decrease. Conclusions: SFN leads to a reduction in overall QOL. The presence of pain and some autonomic symptoms explained only a small portion of the findings. Muscle Nerve 49:329–336, 2014
Hybrid impotent–incompatible eigenstrain based homogenization
Authors: Fish Jacob , Filonova Vasilina , Yuan Zheng 
Published: May 2013

SUMMARYWe present a constitutive framework for a periodic heterogeneous medium with minimal number of internal variables. The method is based on a variant of the transformation field analysis (TFA) where eigenstrains are discretized using C 0 continuous approximation in matrix dominated mode of deformation, hereafter referred to as impotent eigenstrain mode, whereas in multiphase mode of deformation, the eigenstrains are approximated using the usual C  − 1 approximation. The delay in the onset of inelastic response and the eigenstrain induced anisotropy in a microphase, both characteristic to averaging methods, are alleviated by introducing an eigenstrain upwinding scheme and by enhancing constitutive laws of microphases. The proposed formulation has been verified against a direct numerical simulation. The method has been found to be very accurate in predicting an overall material response at a computational cost comparable with the phenomenological modeling of a periodic heterogeneous medium. Copyright © 2013 John Wiley & Sons, Ltd.
A wave finite element‐based formulation for computing the forced response of structures involving rectangular flat shells
Authors: Mencik Jean‐Mathieu 
Published: May 2013

SUMMARYThe harmonic forced response of structures involving several noncoplanar rectangular flat shells is investigated by using the Wave Finite Element method. Such flat shells are connected along parallel edges where external excitation sources as well as mechanical impedances are likely to occur. Also, they can be connected to one or several coupling elements whose shapes and dynamics can be complex. The dynamic behavior of the connected shells is described by means of numerical wave modes traveling towards and away from the coupling interfaces. Also, the coupling elements are modeled by using the conventional finite element (FE) method. A FE mesh tying procedure between shells having incompatible meshes is considered, which uses Lagrange multipliers for expressing the coupling conditions in wave‐based form. A global wave‐based matrix formulation is proposed for computing the amplitudes of the wave modes traveling along the shells. The resulting displacement solutions are obtained by using a wave mode expansion procedure. The accuracy of the wave‐based matrix formulation is highlighted in comparison with the conventional FE method through three test cases of variable complexities. The relevance of the method for saving large CPU times is emphasized. Its efficiency is also highlighted in comparison with the component mode synthesis technique. Copyright © 2013 John Wiley & Sons, Ltd.
Regularization of the noisy Cauchy problem solution approximated by an energy‐like method
Authors: Rischette R. , Baranger T. N. , Andrieux S. 
Published: May 2013

SUMMARYThis paper focuses on the regularization of noisy Cauchy data and unknown boundary conditions approximated by the energy‐like minimization method. After providing considerations necessary for the numerical analysis leading to an adequate stopping criterion for the minimization process, we describe the denoising procedure proposed. Numerical experiments involving singular data are presented.Copyright © 2013 John Wiley & Sons, Ltd.
Numerical manifold space of Hermitian form and application to Kirchhoff's thin plate problems
Authors: Zheng Hong , Liu Zhijun , Ge Xiurun 
Published: May 2013

SUMMARYFor second‐order problems, where the behavior is described by second‐order partial differential equations, the numerical manifold method (NMM) has gained great success. Because of difficulties in the construction of the H 2‐regular Lagrangian partition of unity subordinate to the finite element cover; however, few applications of the NMM have been found to fourth‐order problems such as Kirchhoff's thin plate problems. Parallel to the finite element methods, this study constructs the numerical manifold space of the Hermitian form to solve fourth‐order problems. From the minimum potential principle, meanwhile, the mixed primal formulation and the penalized formulation fitted to the NMM for Kirchhoff's thin plate problems are derived. The typical examples indicate that by the proposed procedures, even those earliest developed elements in the finite element history, such as Zienkiewicz's plate element, regain their vigor. Copyright © 2013 John Wiley & Sons, Ltd.
High‐resolution migration history of the Subtropical High/Trade Wind system of the northeastern Pacific during the last ~55 years: Implications for glacial atmospheric reorganization
Authors: Cheshire Heather , Thurow Juergen 
Published: May 2013

AbstractGuaymas Basin, Gulf of California, is a restricted basin located under the present‐day wet/dry subtropical divide (~27°N) and is ideally circumstanced for detecting variations in the North Pacific Subtropical High (NPSH)/Trade Wind system. Controlled by climate cell boundary displacement, NPSH midwinter location was the primary influence on timing and intensity of upwelling seasons in Guaymas Basin. Analysis of high‐resolution X‐ray fluoresence data and sediment fabric log from 75% laminated Core MD02‐2517/2515, western Guaymas Basin, reveals systematic changes in NPSH behavior over the last ~55 kyr BP. Southward displacement of the wet/dry subtropical divide controlled upwelling‐related diatom productivity, while sea level and regional rainfall controlled terrigenous supply. The basin was oxic during the glacial, and preservation was ensured by high burial rate due to the increased deposition of terrigenous sediment. Sediment fabric style (number and/or thickness of laminae, plus color banding and homogeneous intervals) changes systematically through the core and gives insights into the number of seasons occurring in Guaymas Basin, and the occurrence and intensity of the upwelling season. Five millennial‐scale low flux events with close timing to Heinrich events and ten decadal/centennial‐scale low biogenic silica events occurring in the interval ~33–16.5000 years Before Present (kyr BP) are interpreted as times of extreme aridity. At ~16.5 kyr BP, a regime shift from terrigenous‐dominated oxic to evenly balanced biogenic‐terrigenous dysoxic conditions occurred. Although there was a further extreme arid event at ~11.5 kyr BP, ~16.5 kyr BP was essentially the beginning of the interglacial.
The impact of extended longitudinal observation on the assessment of personality disorders
Authors: Pedersen G. , Karterud S. , Hummelen B. , Wilberg T. 
Published: May 2013

ABSTRACTMultiple sources of information are necessary for a valid assessment of personality disorders (PDs). This study investigates the impact of longitudinal observation. The sample comprised 1217 patients from 15 different treatment units. PDs were assessed at admission to treatment using the Structured Clinical Interview for DSM‐IV Axis II Personality Disorders (SCID‐II) and additional clinical information (best estimate diagnosis). After approximately 18 weeks of treatment, the SCID‐II protocols were re‐examined at clinical conferences and the diagnostic status reassessed on the basis of longitudinal observations in multiple group situations (longitudinal, expert, all data principle). Using this procedure, 78% of the patients' diagnostic criteria sets were changed, and 32% of patients' diagnostic statuses were changed. Many (32%) patients who were evaluated initially as not having a PD received a PD diagnosis after re‐examination. The information provided by customary clinical assessment has important limitations, and longitudinal observation provides additional information that may change the diagnostic status in approximately one‐third of PD cases. Copyright © 2013 John Wiley & Sons, Ltd.