bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling the behavior of sandstone based on generalized plasticity concept
Authors: Weng Meng‐Chia , Ling Hoe I. 
Published: August 2012

SUMMARYWith the concept of generalized plasticity, a constitutive model for describing the deformation behavior of sandstone is proposed in this paper. This proposed model is characterized by the following features: (i) nonlinear elasticity under hydrostatic and shear loading; (ii) associated flow rule for pre‐peak simulation; (iii) substantial plastic deformation during shear loading; and (iv) significant shear dilation and distortion prior to the failure state. This model requires 10 material parameters, including three for elasticity and seven for plasticity. All of the parameters can be determined, in a straightforward manner, by the suggested procedures. The proposed model has been validated by comparing the triaxial test results of the Mushan sandstone under different hydrostatic stress, different stress paths, and cyclic loading condition. It is also versatile in simulating the deformation behaviors of two other sandstones. Upon slight modification of the model, the post‐peak behavior of sandstone can be reasonably predicted using proposed model. Copyright © 2012 John Wiley & Sons, Ltd.
Linear Enamel Hypoplasia and Age‐at‐Death at Medieval (11th–16th Centuries) St. Gregory's Priory and Cemetery, Canterbury, UK
Authors: Miszkiewicz Justyna Jolanta 
Published: August 2012

AbstractLinear enamel hypoplasia (LEH) is a macroscopically detectable band‐like dental defect, which represents localized decrease in enamel thickness caused by some form of disruption to a child's health. Such dental deformations are utilized in osteoarchaeological research as permanent markers of childhood physiological stress and have been extensively studied in numerous ancient human populations. However, currently there is no such data for medieval populations from Canterbury, UK. Here, LEH is examined in the context of age‐at‐death in human burials from the medieval St. Gregory's Priory and adjacent cemetery (11th–16th centuries), Canterbury, UK. The cemetery and Priory burials represented lower (n = 30) and higher status (n = 19) social groups, respectively.Linear enamel hypoplastic defects were counted on mandibular and maxillary anterior permanent teeth (n = 374). The age and sex of each skeleton were estimated using standard methods. Differences in LEH counts, age‐at‐death, and LEH formation ages were sought between the two social groups. Results indicate significantly greater frequencies of LEH in the Cemetery (mean = 17.6) compared to the Priory (mean = 7.9; t = −3.03, df = 46, p = 0.002). Adult age‐at‐death was also significantly lower in the Cemetery (mean = 39.8 years) compared to the Priory burials (mean = 44.1 years; t = 2.275, df = 47, p = 0.013). Hypoplasia formation ages differed significantly between the Priory (mean = 2.49 years) and Cemetery (mean = 3.22 years; t = 2.076; df = 47; p = 0.034) individuals.Results indicate that childhood stress may reflect adult mortality in this sample, and that the wellbeing of individuals from diverse social backgrounds can be successfully assessed using LEH analyses. Results are discussed in terms of the multifactorial etiology of LEH, as well as weaning‐related LEH formation. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis and characterization of polypyrrole‐platinum composite for use as electrode material
Authors: Jayasree R. , Chandrasekar R. , Cindrella L. 
Published: August 2012

AbstractSynthesis and characterization of polypyrrole (PPy) supported platinum by a simple method is reported in this study. The porous structure of PPy and its tendency for doping with acids prompted us to utilize this property to incorporate platinum by adsorption followed by reduction on the PPy matrix. Dispersed platinum electro catalyst on the conducting PPy support provides favorable reaction site for redox reactions in electrochemical devices such as hydrox fuel cell. The mesoporous matrix of PPy as revealed by FESEM could facilitate effective contact between the reactant gases and electro catalyst. The cauliflower like structure of the PPy matrix could enhance the electrochemical active surface area of the catalyst. The composite material is characterized by cyclic voltammetry (CV), polarization study, four probe technique, density and porosity study. The CV highlights the use of PPy‐Pt hybrid as a capacitor and the Tafel plot infers on the high exchange current density of the hybrid material. POLYM. COMPOS. 2012. © 2012 Society of Plastics Engineers
Clinical prediction rule to identify high‐risk inpatients for adverse drug events: the JADE Study
Authors: Sakuma Mio , Bates David W. , Morimoto Takeshi 
Published: August 2012

ABSTRACTPurposeAdverse drug events (ADEs) are common health problems worldwide. Developing a prediction rule to identify patients at high risk for ADEs to prevent or ameliorate ADEs could be one attractive strategy.MethodsThe Japan Adverse Drug Events (JADE) study is a prospective cohort study including 3459 participants. We randomly divided the JADE study cohort into the derivation and the validation sets, using an automated random digit generator. We calculated the probabilities of ADE in each patient in the validation set after applying the prediction rule developed in the derivation set. The actual incidence and area under the receiver operating characteristic curve (AUC) in the validation set were compared with those in the derivation set to evaluate the prognostic ability of our developed prediction rule.ResultsThe developed prediction rule included eight independent risk factors. Each patient in the validation set was classified into three categories of risk for the ADEs according to the probability of ADEs calculated by the developed prediction rule. Eight percent (137/1730) of patients in the validation set fell into the high‐risk group, and 35% of this group (48/137) had at least one ADE. The AUC in the validation set was 0.63 (95%CI 0.60–0.66), and the performance to discriminate the probability of ADE was similar (p = 0.08) compared with that in the derivation set.ConclusionsThis prediction rule had the modest predictive ability and could help physicians and other healthcare professionals to make an estimation of patients at high risk for ADEs. Copyright © 2012 John Wiley & Sons, Ltd.
Morphological, electrical and electromagnetic interference shielding characterization of vapor grown carbon nanofiber/polystyrene nanocomposites
Authors: Al‐Saleh Mohammed H , Sundararaj Uttandaraman 
Published: August 2012

AbstractThe influence of melt mixing conditions on the level of dispersion and the aspect ratio of vapor grown carbon nanofibers (VGCNFs) in a polystyrene (PS) matrix was studied. Final electrical and electromagnetic shielding capabilities in the 0.05–1.5 GHz frequency range are reported and discussed in the light of the composites' microstructure. The morphological study was based on analyzing scanning electron microscopy and optical microscopy micrographs and measuring the VGCNF length as a function of shear mixing conditions. The influence of mixing conditions on the microstructure was also indirectly studied by analyzing the dynamic mechanical behavior of the composites via rheology. Degradation of the VGCNF aspect ratio was found to be a function of the mixing energy. VGCNFs lost one‐third of their aspect ratio under gentle (low shear stress and mixing energy) mixing conditions. After VGCNFs had lost 40% of their aspect ratio, they had more resistance to breakage with increase in mixing energy. The dispersion of the VGCNFs was remarkably enhanced with increase in mixing energy. The percentage of area taken up by big agglomerates in the micrographs decreased from 14.1% to 5.5% when the mixing energy was increased from 100 J mL−1 to 453 J mL−1. The electrical and electromagnetic shielding properties of the 7.5 vol% VGCNF/PS composites were not affected by changing the processing energy because the enhancement of VGCNF dispersion with increasing mixing energy was accompanied by a loss in nanofiber aspect ratio. © 2012 Society of Chemical Industry
Mechanical and electrical properties of carbon nanotubes surface‐stamped on polydimethylsiloxane for microvalve actuation
Authors: Salzbrenner Jeffrey , Apblett Christopher , Khraishi Tariq 
Published: August 2012

AbstractWe report a study of the electrical and mechanical effects of the inclusion of a thin layer of multiwalled carbon nanotubes (MWCNTs) into the surface of polydimethylsiloxane (PDMS) as a method of creating an electrically actuated, flexible microfluidic valve. Samples of PDMS with various surface loadings of MWCNTs were prepared and tested using a uniaxial tension tester, combined with a four‐point probe electrical test. In contrast to other works reporting the inclusion of MWCNTs in the bulk of the material, we have found that inclusion of the MWCNTs on the surface only has no discernible effect on the mechanical properties of the PDMS samples, but causes a significant and repeatable change in the electrical performance. We have found that a loading of 4.16 g m−2 results in an electrical resistivity of 7.31 × 10−4 Ω cm, which is 200% lower than that previously reported for bulk inclusion samples. The microstructure of the MWCNTs was found to consist of both individual fibers and spherical clumps of fibers. We suggest that, due to the microstructure of the MWCNTs used in this study, the mechanical properties can be modeled as a thin layer of particulates, while the electrical properties can be modeled as a thin bed of bulk MWCNTs. © 2012 Society of Chemical Industry
Cationic cure kinetics of a polyoxometalate loaded epoxy nanocomposite
Authors: Anderson Benjamin J. 
Published: August 2012

AbstractThe reaction cure kinetics of a novel polyoxometalate (POM) loaded epoxy nanocomposite is described. The POM is dispersed in the epoxy resin up to volume fractions of 0.1. Differential scanning calorimetry measurements show the cure of the epoxy resin to be sensitive to the POM loading. A kinetics study of the cure exotherm confirms that POM acts as a catalyst promoting cationic homopolymerization of the epoxy resin. The cure reaction is shown to propagate through two cure regimes. A fast cure at short time is shown to be propagation by the activated chain end (ACE) mechanism. A slow cure at long time is shown to be propagation by the activated monomer (AM) mechanism. The activation energies for the fast and slow cure regimes agree well with other epoxy based systems that have been confirmed to propagate by the ACE and AM mechanisms.© 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
New polymer‐chemical developments in clinical dental polymer materials: Enamel–dentin adhesives and restorative composites
Authors: Moszner Norbert , Hirt Thomas 
Published: August 2012

AbstractIn the past 10 years, many new components were synthesized and evaluated for an application in enamel–dentin adhesives and direct composite restoratives. New bisacrylamide cross‐linkers with improved hydrolytic stability and new strongly acidic polymerizable phosphonic acids and dihydrogen phosphates, as well as novel photoinitator systems, in combination with the implementation of novel application devices, have significantly improved the performance of the current enamel–dentin adhesives. The currently used resins for direct composite restoratives are mainly based on methacrylate chemistry to this day. A continuous improvement of the properties of current composites was achieved with the use of new tailor‐made methacrylate cross‐linkers, new additives, and photoinitiators as well as tailor‐made fillers. Nowadays, dental adhesives and methacrylate‐based direct restorative materials have found wide‐spread acceptance. Nevertheless, future developments in the field of dental adhesives and direct composite restoratives will focus on improving durability and biocompatibility as well as the development of materials with a broader application spectrum and of smart adhesives or composites. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Plasma–Liquid Interactions at Atmospheric Pressure for Nanomaterials Synthesis and Surface Engineering
Authors: Mariotti Davide , Patel Jenish , Švrček Vladimir , Maguire Paul 
Published: August 2012

AbstractPlasma‐induced non‐equilibrium liquid chemistry (PiLC) offers enhanced opportunities over solution chemistry for developing new nanomaterials and tailoring their functional properties. Recent advances in the design and scientific understanding of microplasma devices operating at atmospheric pressure offer simple and effective routes to non‐equilibrium chemistry for both scientific study and future nanomanufacturing. This paper presents a short review of our recent work on atmospheric pressure plasma–liquid interactions used in the fabrication and functionalization of nanoparticles. A brief discussion of possible electron‐liquid reactions highlights outstanding scientific and engineering questions. magnified image
Thermokarst Lakes on the Arctic Coastal Plain of Alaska: Geomorphic Controls on Bathymetry
Authors: Hinkel Kenneth M. , Sheng Yongwei , Lenters John D. , Lyons Evan A. , Beck Richard A. , Eisner Wendy R. , Wang Jida 
Published: August 2012

ABSTRACTDetailed bathymetric data were collected for 28 thermokarst lakes across the Arctic Coastal Plain (ACP) of northern Alaska from areas with distinctly different surficial sediments and topography. Lakes found in the low‐relief coastal area have developed in marine silts that are ice‐rich in the upper 6–10 m. The lakes tend to be shallow (~ 2 m), of uniform depth and lack prominent littoral shelves. Further inland on the ACP, lakes have formed in relatively ice‐poor aeolian sand deposits. In this hilly terrain, average lake depth is less (~ 1 m) despite deeper (3–5 m) central pools. This bathymetry reflects the influence of broad, shallow littoral shelves where sand, eroded from bluffs at the lake margin, is deposited concurrently with deep penetration of the talik beneath the basin centre. Lakes in the ACP‐Arctic Foothills transition zone to the south have developed in loess uplands. These yedoma deposits are extremely ice‐rich, and residual lakes found inside old lake basins (alases) are generally 2–4 m deep, reflecting continued talik development and ground subsidence following drainage of the original lake. However, where the expanding lake encroaches on the flanks of the upland at actively eroding bluffs, near‐shore pools develop that can be 6–9 m deep. It appears that thawing of ice‐rich permafrost during lake expansion causes ground subsidence and formation of deep pools above ablating ice wedges. These data suggest that thermokarst lake morphometry largely depends on the characteristics of the substrate beneath the lake and the availability of sediments eroded at the lake margin. Copyright © 2012 John Wiley & Sons, Ltd.
Toward understanding the microscopic origin of nuclear clustering
Authors: Okołowicz J. , Nazarewicz W. , Płoszajczak M. 
Published: August 2012

AbstractOpen Quantum System (OQS) description of a many‐body system involves interaction of Shell Model (SM) states through the particle continuum. In realistic nuclear applications, this interaction may lead to collective phenomena in the ensemble of SM states. We claim that the nuclear clustering is an emergent, near‐threshold phenomenon, which cannot be elucidated within the Closed Quantum System (CQS) framework. We approach this problem by investigating the near‐threshold behavior of Exceptional Points (EPs) in the realistic Continuum Shell Model (CSM). The consequences for the alpha‐clustering phenomenon are discussed.
The double Gaussian distribution of inhomogeneous barrier heights in the organic‐on‐inorganic Schottky devices
Authors: Tuğluoğlu Nihat , Yüksel Ö. Faruk , Şafak Haluk , Karadeniz Serdar 
Published: August 2012

AbstractWe have fabricated an Au/perylene–monoimide (PMI)/n‐Si organic‐on‐inorganic Schottky device by spin coating of PMI solution on an n‐Si semiconductor wafer. Current–voltage (I–V) measurements on the device in the temperature range of 75–300 K were carried out. An abnormal decrease in the experimental barrier height ΦB and an increase in the ideality factor n with a decrease in temperature have been observed. This behaviour has been explained on the basis of thermionic emission theory with a double Gaussian distribution of the barrier heights due to the barrier height inhomogeneities.
In situ high‐pressure synchrotron X‐ray diffraction study of the structural stability in the intermetallic compound Mn2Sb
Authors: Yu Z. H. , Li C. Y. , Liu H. Z. 
Published: August 2012

AbstractCu2Sb‐type (Strukturbericht designation: C38) intermetallic compound Mn2Sb was studied up to 25.7 GPa at room temperature using the in situ synchrotron powder X‐ray diffraction (XRD) technique. Our results from the XRD analysis showed that the (C38)‐type Mn2Sb undergoes a pressure‐induced structural phase transition near 22.4 GPa. In the low‐pressure (LP) phase of Mn2Sb, an anisotropic compressibility was observed with greater compressibility along the a‐axis than the c‐axis. And the mechanism for the anisotropy of compressibility was discussed in terms of the stacking of crystallography. Fitted to a third‐order Birch–Murnaghan equation of state (BM‐EOS), the pressure–volume data of Mn2Sb yielded the stable lattice volume V0 = 109.45(3) Å3, bulk modulus B0 = 50.1(5) GPa, and its derivative $B'_{{\rm 0}} $ = 7.0(2) for the LP phase. We propose that the distortion of Mn(I)Sb4 tetrahedra may give rise to the structural instability of Mn2Sb under high pressure (HP).
Investigation of Si nanowires from VLS growth
Authors: Herr Ulrich , Riedmueller Benjamin , Haddad Mike , AbuShgair Khaleel , Madel Manfred , Jakob Julian Benjamin , Thonke Klaus 
Published: August 2012

AbstractSi nanowires are of interest for photovoltaics and sensors. We report about the growth of Si nanowires from SiH4 using a Au catalyzed vapor‐liquid‐solid (VLS) growth process in a tube furnace at atmospheric pressure. At elevated growth temperatures, single crystalline wires with clear facets are obtained. The influence of the furnace temperature and the Au layer thickness on the nanowire growth is investigated in detail. The orientation of the wires has been studied by EBSD. For electrical characterization, Pt metal contacts have been applied to individual wires using Pt deposition in a FIB microscope. The high values found for the conductivity indicate that Ga implantation occurs during the FIB process. Electrical characterization under illumination shows the presence of a significant photoconductivity. Further functionalization of the Si nanowires will be done by combining them with luminescent nanoparticles (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Computational studies of the corrosion‐inhibition efficiency of iron by triazole surfactants
Authors: Touil M'hamed , Hajjaji Najat , Sundholm Dage , Rabaâ Hassan 
Published: August 2012

AbstractThe corrosion‐inhibition efficiency of N‐decyl‐1,2,4‐triazole, N‐undecyl‐1,2,4‐triazole, and N‐dodecyl‐1,2,4‐triazole surfactants and the corresponding protonated molecules have been studied computationally using density functional theory and second‐order Møller–Plesset calculations. Corrosion‐inhibition properties and the strength of the affinity of the iron‐surfactant molecules were estimated by using an appropriate cluster model. The iron‐surfactant complexes were constructed by attaching the triazole ring to the iron surface modeled by one and five iron atoms, respectively. Relations between molecular properties and corrosion‐inhibition efficiency were determined by using linear regression and quantitative structure–activity relationship (QSAR). The QSAR analysis yielded significant correlations between the corrosion‐inhibition activity of the studied molecules with molecular properties such as the highest occupied molecular orbital, the lowest unoccupied molecular orbital, dipole moments (μ), and the total atomic charges. Fukui indexes were also calculated for assessing correlations between them and experimental corrosion‐inhibition efficiencies. Solvent effects were investigated by using the polarized continuum model. The effects of the acidity medium and the local reactivity of the triazole derivatives with iron were also analyzed. The calculated binding energy of 276 kJ/mol for the Fe5‐N‐dodecyl‐1,2,4‐triazole cluster shows that the surfactant molecules bind strongly to iron surfaces, which is in agreement with experimental data. © 2012 Wiley Periodicals, Inc.
End Temperature Prediction of Molten Steel in LF Based on CBR
Authors: He Fei , Xu Anjun , Wang Hongbing , He Dongfeng , Tian Naiyuan 
Published: August 2012

AbstractIn order to improve the temperature control level of molten steel in ladle furnace (LF), a case‐based reasoning (CBR) method has been proposed for predicting end temperature of molten steel in LF. To predict the temperature accurately and efficiently, this paper develops two‐step retrieval approach and the correlation based feature weighting (CFW) method for CBR. And, the study evaluates the prediction effect of CBR method by the experiment of comparison with back propagation neural network (BPNN) model and CBR model. Experimental results show that CBR model achieves better accuracy than BPNN model and the CBR method is effective to predict end temperature of molten steel in LF.
The Influence of Hot Charging Conditions on Microstructure and Precipitation of High Strength Nb–Ti Complex Microalloyed Steels
Authors: Luo Yanzhao , Zhang Jiongming , Xiao Chao , Song Wei , Wang Shunxi 
Published: August 2012

AbstractA comprehensive microstructure analyses were conducted for hot charging processed Nb, Ti microalloyed steel, especially focusing on the evolution of microstructure and precipitation behavior. Hot charging process was simulated in the laboratory in the current research. Precipitation and microstructure in Ti–Nb microalloyed HSLA steels were investigated in different hot charging temperature conditions using transmission electron microscope (TEM), optical microscopy, analytical transmission electron microscopy, and energy dispersive spectroscopy (EDS). The results showed that the microstructure consists of fine and homogeneous lath bainite at 1000°C, lath bainite and granular bainite at 900°C. As the hot charging temperature decreased, there appeared a small fraction of proeutectoid ferrite along grain boundary at 800°C. The grain sizes in hot charging are coarse compared with that of 700°C due to the phase transformation didn't occur. The chemical composition of complex carbonitrides changes from Ti rich to Ti–Nb uniform with decreasing temperature.
Synthesis, Structure, and Characterization of [FeIIILCl3] (L = 1, 4, 8‐Triazacycloundecane, 1, 4, 7‐Triazacyclononane)
Authors: Banerjee Atanu , Panda Manashi , Tolla Azam S. , Li Jia , Brennessel William W. , Loloee Reza , Chavez Ferman A. 
Published: August 2012

AbstractThe structures of [FeIII(tacud)Cl3] (1) and [FeIII(tacn)Cl3] (2) (tacud = 1, 4, 8‐triazacycloundecane, tacn = 1, 4, 7‐triazacyclononane) are reported. Both compounds crystallize in the orthorhombic space group Pnma with a = 12.5570(9), b = 12.0028(9), c = 8.2577(6) Å, V = 1244.59(16) Å3, and Z = 4 for 1 and a = 12.095(4), b = 11.125(4), c = 7.963(3) Å, V = 1071.5(6) Å3, and Z = 4 for 2. The structures of 1 and 2 feature iron(III) in distorted octahedral arrangement with three facially coordinated nitrogen ligands and three chlorides. Bidirectional intermolecular hydrogen bonding between N–H groups and coordinated chlorides is seen for 1 and 2. Compound 1 is the first example of iron(III) bonded to tacud and compound 2 is only the second structure reported of a 1:1 complex between iron and tacn. The Fe3+/2+ redox couple for 1 is observed at E1/2 = 0.25 V (ΔEp = 99 mV), and for 2 at E1/2 = 0.09 V (ΔEp = 108 mV) versus NHE in DMF at 298 K. Comparison of structural, magnetic, and electrochemical properties for 1 and 2 reveal subtle differences consistent with the stronger coordinating properties of tacn relative to tacud.