bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elasto-plastic and creep behaviour of axially loaded, shouldered tubes
Authors: Dawson R J , Fessler H , Hyde T H , Webster J J 
Published: July 2007

This paper compares the finite element predictions of elasto-plastic and creep behaviour with experimental data for axially loaded, shouldered tube models. Four shouldered tube models were made of a lead alloy and tested at 61°C, using strain gauges to measure the elasto-plastic and creep strains in the plain tube and fillet regions of the models. Instantaneous stress-strain and creep data were obtained from strain-gauged, uniaxial tensile specimens. The finite element solutions are based on the incremental Prandtl-Reuss equations. The elasto-plastic iterative solutions use a ‘negative gradient’ from the calculated point to the equivalent stress-equivalent strain curve to get the next estimate of the plastic strain increment. A time incremental method is used to obtain the creep solutions. Tests with the mean tube stress below, at and above the yield stress showed very good agreement between prediction and measurement of initial strains in the fillets. Differences between predictions and measurements of creep strains are attributable to cast-to-cast variations.
Model road-tank metal vessels subject to internal explosion or static penetration
Authors: Johnson W , Reddy T Yella , Reid S R 
Published: July 2007

Thin-walled tubes, having hemi-spherical ends and four symmetrically placed stiffening rings to model a typical road transport tank container, were subjected to a mechanical loading from either: (i) an axial line or point charge of explosive, or (ii) static penetration from the outside by a punch to determine their plastic deformation characteristics. The vessels were examined when: (a) nominally empty, (b) air pressurized, and (c) almost completely full of water. Results for a range of tests in which the vessels were not stiffened are also reported and this facilitates useful comparison between the stiffened and unstiffened cases.
A thermo-plastic shear instability criterion applied to surface cracking in upsetting and related processes
Authors: Jenner A , Bai Y , Dodd B 
Published: July 2007

The workability of wire and rod in upsetting and related processes is dependent on the ductility exhibited by the expanding free surface. From previous measurements of the equatorial strain histories during incremental upsetting of cylinders, linear fracture conditions for a large number of materials of engineering importance have been derived. A simple theoretical explanation of the experimentally observed fracture condition is given. This is done using the concept of a thermo-plastic shear instability criterion. It is shown that one mode of shear instability coincides with the observed straight-line fracture condition.
Mounting deformations of hydraulically expanded taper-sleeve couplings
Authors: Fessler H , Stewart R W 
Published: July 2007

The ‘frozen deformation’ method has been used to determine the deformations of the hub, taper-sleeve, and shaft of a flanged coupling as used in marine gear boxes. Hydraulic mounting caused gaps between hub and sleeve over most of the length of the hub. Contact occurred at the ends of the hub only. with the sleeve in tension or in compression during mounting. The presence of a flange at either end of the coupling did not change the above significantly.
Araldite models for the study of elastic stability of plates
Authors: Narayanan R , Chow F Y 
Published: July 2007

The suitability of Araldite as a model material for the study of plate instability problems is investigated. Model tests on stiffened plates made of Araldite and steel sheeting are reported and the test results are compared with theoretical predictions. The overwhelming advantage in testing Araldite models is due to the large range of material elasticity (extending up to 36 000 microstrain compared with 1200–1600 microstrain for steel). Models made of Araldite are shown to be useful in simulating buckling modes and in obtaining magnified values of the likely plate and stiffener deformations in the serviceability and ultimate limit states. The ultimate capacity predicted from models is, however, significantly lower than the values of the corresponding steel prototypes on account of the early loss of stiffness of the members caused by the large deformations.
Stresses in axisymmetric rotating bodies determined by the boundary integral equation method
Authors: Abdul-Mihsein M J , Bakr A A , Parker A P 
Published: July 2007

An alternative approach to arrive at the fundamental solution of the boundary integral equation (BIE) for axisymmetric elastostatic problems with rotational body force is presented. The formulation is implemented in an elastostatic BIE axisymmetric program using isoparametric quadratic elements. The method is applied to rotating disks of constant or variable thickness and linearly tapered. The results compare very well with avaialable analytical and numerical solutions.
An assessment of local radial loads on cylinders based on the Sanders linear shell equations
Authors: Timmins W , Little W , Findlay G E 
Published: July 2007

In a recent paper, two of the present authors showed that the maximum stresses measured in a cylindrical shell subjected to a radially applied local load were higher than BS 5500, Appendix G could predict. In order to investigate this apparent discrepancy, an analysis of a cylindrical shell under non-axisymmetric radial loading was carried out using Sanders linear shell equations, which are generally acknowledged as being the most exact available. It is shown, however, that the results from this analysis do not provide better agreement with experiment than those earlier analyses on which design codes are now currently based.
The prediction of stress rupture life of notched specimens in the beta-processed titanium alloy Ti5331s
Authors: Webster P S , Pickard A C 
Published: July 2007

Methods of predicting notched bar stress rupture behaviour are reviewed. Two very different types of notched specimens are analysed using the finite element method; one being a circumferentially V-notched test piece, the other having two semi-circular notches in a plane section. A prediction based on the Von Mises equivalent stress distribution is proposed. Predictions using this method are compared with notched specimen test results in a commercially available titanium alloy, Ti5331s, tested at 600°C. The correlation is good for the semi-circular notched specimen and for the V-notched specimen at low stress, long life and can be improved at high stresses by making allowance for time independent plasticity and for the initial high rate of creep strain accumulation at the notch root.
An assessment of a model method for predicting the fracture of cracked components
Authors: Hyde T H , Yaghi A 
Published: July 2007

Three-point-bend (3PB) specimens with real cracks and very sharp notches have been manufactured from Araldite CT200 with HT907 hardener. The plane strain fracture toughness, KIC, has been obtained from cracked specimen tests and the apparent plane strain fracture toughness, KAppIC, has been obtained for various very sharp notched widths. A systematic variation of apparent fracture toughness with notch width has been observed. Burst tests have also been performed on cylinders with similar, very sharp, axially aligned, external, semi-circular notches. It has been shown that the burst pressure for the cylinders, with different depths of crack, can be predicted from the corresponding 3PB apparent fracture toughness data. The notches in the cylinders and 3PB specimens must be very sharp, and manufactured in a similar way, for the predictions to be accurate. Therefore, by loading model components containing very sharp crack-like flaws to obtain the failure loads, the failure loads of similar actual components having a real crack and behaving in a brittle manner can be predicted.
Analysis of stress concentration factors for stepped plates based on a crack tip stress intensity approach
Authors: Gray T G F , Tournery F , Spence J 
Published: July 2007

The analytical equations given for stress concentration factors are based on the results of finite element analysis of stepped plates subject to uniaxial tension loading. The fillet radii at the stepped transitions were varied over a wide range, leading to elastic stress concentration factors between 1.1 and 8.3 (net stress basis). The parametric equations depend on the previously described concept of a ‘notch configuration factor’. This is similar to the crack configuration factor or compliance function used to modify the basic crack tip stress intensity solutions in the case of finite width or other problems. In the present case of the stepped plate, an energy approach was used to relate the sharp corner stress field to the corresponding sharp crack field, leading to a ‘sharp corner configuration factor’. This factor was then applied to the equation for the stress concentration factor at an elliptical hole in an infinite plate, to give a simple analytical expression for the stepped plate with a radiused fillet. The basic expression was refined further to improve the quality of fit, to an accuracy of 2 per cent with respect to the finite element models.
Balancing rigour and relevance: researchers’ contributions to children’s mental health policy in Canada
Authors: Waddell Charlotte , Shepherd Cody A. , Lavis John N. , Lomas Jonathan , Abelson Julia , Bird-Gayson Twylla 
Published: July 2007

English
We investigated researchers’ experiences of, and views on, interacting with policy makers, using children’s mental health as an example. Qualitative methods were used to interview university researchers, policy researchers, and research funders. Participants spoke of contributions to policy that went beyond interaction with policy makers. We describe how participants became motivated, developed approaches, and created new environments to contribute to policy. Our findings suggest that university researchers should challenge their peers to better recognise and support policy interaction and public engagement. Both university and policy researchers must balance academic rigour and policy relevance to make meaningful contributions to policy.
The production and management of evidence for public service reform
Authors: Shepherd Jonathan 
Published: July 2007

English
Public services depend on the production, distribution and application of evidence of effectiveness. Existing strengths of this process in the UK include many university schools closely associated with services, a strategic partnership of Research Councils, some service-specific excellence institutes and successful models for evidence management, particularly in health. However, there is little recognition that this research is fundamental to society. There are few formal connections between the national science base, the Research Councils and public services designed to focus research effort or to increase evidence quality. Components of evidence management systems need to be recognised as such, integrated and connected. At each stage, practical reforms are identified, designed to ensure that services continuously develop in response to reliable new knowledge.
Diabetes Management Issues for Patients With Chronic Kidney Disease
Authors: Cavanaugh Kerri L. 
Published: July 2007

IN BRIEF
Chronic kidney disease (CKD) is common and can be found in up to 23% of patients with diabetes. The recommended hemoglobin A1c goal for these patients is also &lt; 7.0%. Medication therapy for diabetes may require dose adjustments or may be contraindicated in patients with CKD. Assessment and management of comorbid diseases, including hypertension, hyperlipidemia,anemia, hyperphosphatemia, and hyperparathyroidism, is important in the care of patients with diabetes and CKD. Multidisciplinary care may provide the optimal system for maximizing care of these complex patients.
Biofunctionalization of Gold Nanoparticles
Authors: Zheng Ming , Huang Xueying 
Published: July 2007

AbstractThe sections in this article areIntroductionGeneral Synthetic RoutesDirect Synthesis of Ligand‐protectedAuNPsStrongly Ionic Ligand‐protectedAuNPsWeakly Ionic Ligand‐protectedAuNPsAuNPsProtected with Neutral LigandsLigand Exchange ReactionPreparative‐scale Synthesis and Solution‐phase Characterization ofDNA‐directed Nanoparticle AssembliesBifunctional Proteins for Programmable Assembly of NanoparticlesStrategies for Eliminating Nonspecific Interactions and Enabling Specific Binding with BiomoleculesBiological ApplicationsNucleic AcidsProteinsCells and VirusAcknowledgments
Cover Picture: Reconstructing a Nanoporous Metal in Three Dimensions: An Electron Tomography Study of Dealloyed Gold Leaf (Adv. Eng. Mater. 7/2007)
Authors: Rösner H. , Parida S. , Kramer D. , Volkert C. A. , Weissmüller J. 
Published: July 2007

AbstractBack‐Cover‐Page: Nanoporous gold, prepared by electrochemical dissolution of Ag from commercial white gold leaf, was investigated by HAADF‐STEM tomography. The picture shows a surface‐rendering of a fully connected network structure composed of single‐crystalline gold ligaments and pores reconstructed in three dimensions. The study advertises the power of electron tomography as an emerging tool for elucidating the three‐dimensional microstructure of materials with a nanoscale resolution. Further Information can be found in the paper by Rösner et al. on page 535.
Stable, Low‐Temperature Discotic Nematic Superstructures by Incorporating a Laterally Substituted Sidearm in Hexakis(phenylethynyl)benzene Discogens
Authors: Chien S.‐C. , Chen H.‐H. , Chen H.‐C. , Yang Y.‐L. , Hsu H.‐F. , Shih T.‐L. , Lee J.‐J. 
Published: July 2007

AbstractA new strategy for preparing room‐temperature discotic nematic materials is proposed and developed stepwise to improve various discotic nematic properties. This approach replaces one sidearm of the discotic hexakis(4‐hexyloxyphenylethynyl)benzene with a tris(alkoxy) sidearm, 1‐ethynyl‐2,3,4‐tris(hexyloxybenzene), to lower transition temperatures, manipulate discotic nematic ranges, and preserve the discotic nematic superstructure while preventing column formation. Although symmetry considerations play a role in the resulting mesogenic properties, steric hindrance and van der Waals interactions are ascribed to the superior discotic nematic properties of the newly prepared discogens containing a laterally substituted sidearm.
Low‐Work‐Function Surface Formed by Solution‐Processed and Thermally Deposited Nanoscale Layers of Cesium Carbonate
Authors: Huang J. , Xu Z. , Yang Y. 
Published: July 2007

AbstractNanostructured layers of Cs2CO3 are shown to function very effectively as cathodes in organic electronic devices because of their good electron‐injection capabilities. Here, we report a comprehensive study of the origin of the low work function of nanostructured layers of Cs2CO3 prepared by solution deposition and thermal evaporation. The nanoscale Cs2CO3 layers are probed by various characterization methods including current–voltage (I–V) measurements, photovoltaic studies, X‐ray photoelectron spectroscopy (XPS), UV photoelectron spectroscopy (UPS), and impedance spectroscopy. It is found that thermally evaporated Cs2CO3 decomposes into CsO2 and cesium suboxides. The cesium suboxides dope CsO2, yielding a heavily doped n‐type semiconductor with an intrinsically low work function. As a result, devices fabricated using thermally evaporated Cs2CO3 are relatively insensitive to the choice of the cathode metal. The reaction of thermally evaporated Cs2CO3 with Al can further reduce the work function to 2.1 eV by forming an Al–O–Cs complex. Solution‐processed Cs2CO3 also reduces the work function of Au substrates from 5.1 to 3.5 eV. However, devices prepared using solution‐processed Cs2CO3 exhibit high efficiency only if a reactive metal such as Al or Ca is used as the cathode metal. A strong chemical reaction occurs between spin‐coated Cs2CO3 and thermally evaporated Al. An Al–O—Cs complex is formed as a result of this chemical reaction at the interface, and this layer significantly reduces the work function of the cathode. Finally, impedance spectroscopy results prove that this layer is highly conductive.
Textured Tubular Nanoparticle Structures: Precursor‐Templated Synthesis of GaN Sub‐micrometer Sized Tubes
Authors: Ding S. , Lu P. , Zheng J.‐G. , Yang X. F. , Zhao F. L. , Chen J. , Wu H. , Wu M. M. 
Published: July 2007

AbstractPorous and sub‐micrometer tubes made of textured GaN nanoparticles have been synthesized by an in situ chemical reaction and characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence (PL) and Raman spectroscopies. The in situ reaction involves thermal decomposition and nitridation of 1D gallium oxyhydroxide (GaOOH) at temperatures in the range of 700–900 °C. The 1D shape of the precursor GaOOH is maintained in the resultant GaN tubes. The GaN nanocrystals (estimated to be about 15 nm in size) are found to be highly oriented with respect to each other in the tube structure, with the [110] GaN direction parallel to the tube axis. The growth mechanism of the tube structure has also been studied. β‐Ga2O3 is found to be an intermediate phase between the starting GaOOH precursor and the final GaN product. The growth mechanism involves decomposition of GaOOH, which produces β‐Ga2O3 tubes with hollow interiors, and nitridation of β‐Ga2O3, which leads to growth of textured GaN nanocrystals. Based on the growth mechanism, tubular structures with either quasi‐circular or rectangular cross section are selectively synthesized by controlling the heating rate and calcination temperature. This in situ chemical reaction method provides a new route for synthesizing 1D hollow nanostructures.
Das thermische Verhalten der Phenole. (2. Mitteilung(. Über die Thermodynamik und den Mechanismus des thermischen Zerfalls des Phenols und seiner Homologen)
Authors: Hagemann A. 
Published: July 2007

Abstract1. Die Umwandlungen des Phenols und des Metakresols werden thermodynamisch nach der Nernstschen Näherungsformel bestimmt und die erhaltenen Gleichgewichte diskutiert. – 2. Der Reaktionsmechanismus des thermischen Zerfalls wird auf Grund experimenteller Ergebnisse erklärt.
Reihenversuche mit Natriumsuperoxyd‐Atemgeräten. Zur Kenntnis der Wirkungsweise von Natriumsuperoxyd‐Atemgeräten I
Authors: Stampe G. , Horng E. 
Published: July 2007

AbstractInhalt: Durch systematische Versuche mit Natriumsuperoxydpatronen unter ganz gleichartigen Bedingungen wird bei gegebenem Superoxydpräparat das Optimum des Patronenaufbaus ermittelt.
Preparation and characterization of polyacrylamide cryogels produced from a high‐molecular‐weight precursor. I. Influence of the reaction temperature and concentration of the crosslinking agent
Authors: Ivanov Roman V. , Lozinsky Vladimir I. , Noh Seok Kyun , Han Sung Soo , Lyoo Won Seok 
Published: July 2007

AbstractA new type of cryogel was prepared through a reaction of high‐molecular‐weight polyacrylamide (viscosity‐average molecular weight ≈ 3 × 106 Da) with glutaraldehyde in a moderately frozen aqueous medium. The influence of the crosslinking agent concentration and temperature of the reaction on the gel fraction yield, swelling characteristics, and morphology of the cryogels was investigated. The dependence of the gel fraction yield on the reaction temperature was bell‐shaped. The recognized regularities of the formation of this new type of polyacrylamide cryogel based on a high‐molecular‐weight precursor were very similar to those observed earlier for polyacrylamide cryogels synthesized through the cryopolymerization of monomeric precursors. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Preparation of atactic poly(vinyl alcohol)/sodium alginate blend nanowebs by electrospinning
Authors: Lee Young Jae , Shin Dong Soo , Kwon Oh Wook , Park Won Ho , Choi Han Gon , Lee Yong Rok , Han Sung Soo , Noh Seok Kyun , Lyoo Won Seok 
Published: July 2007

AbstractThrough the blending of a rigid polymer, sodium alginate (SA), and a flexible polymer, atactic poly(vinyl alcohol) (PVA), with various ratios of SA and PVA and through the electrospinning of SA/PVA solutions, SA/PVA blend nanowebs were successfully prepared. The structure and morphology of the SA/PVA blend nanowebs were investigated through a series of instrumental analyses. Through the examination of the morphological variations of each blend web, it was found that with only PVA, the electrospun nanowebs had very uniform and fine fiber structures, but the SA/PVA blend nanowebs had a mixture of large beads and fibers, which were generated with increasing SA content. A thermal analysis indicated that the endothermic peaks of the SA/PVA blend nanowebs decreased with an increase in the SA content. The SA content was determined by the observation of the changes in the SA peak intensity via Fourier transform infrared spectroscopy. The tensile strength decreased with increasing SA content. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Effect of structure on the tribological properties of polytetrafluoroethylene drawn uniaxially at the melting point
Authors: Liu Xiaoxia , Li Tongsheng , Liu Xujun , Lv Renguo , Cong Peihong 
Published: July 2007

AbstractDrawn polytetrafluoroethylene (PTFE) with different draw ratio and sliding directions were investigated using a pin‐on‐disc tester. The anisotropy of tribological properties for drawn PTFE was found and the lowest friction coefficient and wear rate were reached when sliding along draw direction. The higher the orientation degree was, the smaller the friction coefficient and the wear rate were. The morphologies of the samples and debris were characterized by scanning electron microscope. The results showed that the fiber structure of drawn PTFE was formed and the morphologies of debris were different from undrawn PTFE. The results indicated that the bulk orientation structure of drawn PTFE played an important role on its tribological properties. The shear force was parallel with the oriented fibrils formed by drawing when sliding along draw direction and a better smoothing worn surface occurred easily, which resulted in the low friction coefficient. The fiber formed by drawing prevented effectively the large flake‐like debris from formation, which reduced the wear rate of drawn PTFE. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Study of the thermomechanical and electrical properties of conducting composites containing natural rubber and carbon black
Authors: Oliveira Fernando A. , Alves Neri , Giacometti José A. , Constantino Carlos J. L. , Mattoso Luiz H. C. , Balan Ana M. O. A. , Job Aldo E. 
Published: July 2007

AbstractThis work describes the preparation and characterization of composite materials obtained by the combination of natural rubber (NR) and carbon black (CB) in different percentages, aiming to improve their mechanical properties, processability, and electrical conductivity, aiming future applications as transducer in pressure sensors. The composites NR/CB were characterized through optical microscopy (OM), DC conductivity, thermal analysis using differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMA), thermogravimetry (TGA), and stress–strain test. The electrical conductivity varied between 10−9 and 10 S m−1, depending on the percentage of CB in the composite. Furthermore, a linear (and reversible) dependence of the conductivity on the applied pressure between 0 and 1.6 MPa was observed for the sample with containing 80 wt % of NR and 20% of CB. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007