bluuebunny/crossref_metadata_2025 huggingface dataset:
EVERYONE UP HERE: ENREGISTERMENT AND IDENTITY IN MICHIGAN'S KEWEENAW PENINSULA
Authors: Remlinger Kathryn
Published: June 2009

This article investigates historical, economic, and ideological processes that have led to the emergence and development of dialect awareness in Michigan's Keweenaw Peninsula. Relying on the language-ideological approach to language attitudes about linguistic variation, the study examines ethnographic and archival data to determine how the local dialect, Copper Country English, has become enregistered and thus how it has come to index certain cultural values, especially those related to local identity. Copper Country English has not only become recognized as a dialect, but certain features have also become normed through discursive and metadiscursive practices that collectively function to create and maintain the idea of a local dialect and to define a local identity. These notions overlap and shift to affect perceptions of what makes a dialect a dialect and to link language, people, and place.
Ena/VASP: towards resolving a pointed controversy at the barbed end
Authors: Bear James E. , Gertler Frank B.
Published: June 2009

Ena/VASP proteins are conserved regulators of actin dynamics that have important roles in several physiological processes such as morphogenesis, axon guidance, endothelial barrier function, and cancer cell invasion and metastasis. Although considerable evidence points towards an anti-capping mechanism for Ena/VASP function, some controversy remains. Here, we evaluate the evidence for and against the anti-capping hypothesis, including results from some recent structural and biochemical studies that shed new light on this issue. In addition, we describe several alternate mechanisms that Ena/VASP proteins may utilize to regulate actin dynamics in vivo, including inhibition of branching, bundling and profilin-actin recruitment.
EFA6A encodes two isoforms with distinct biological activities in neuronal cells
Authors: Sironi Cristina , Teesalu Tambet , Muggia Anna , Fontana Gabriele , Marino Fortunata , Savaresi Sara , Talarico Daniela
Published: June 2009

The processes of neurite extension and remodeling require a close coordination between the cytoskeleton and the cell membranes. The small GTPase ARF6 (ADP-ribosylation factor 6) has a central role in regulating membrane traffic and actin dynamics, and its activity has been demonstrated to be involved in neurite elaboration. EFA6A has been shown to act as a guanine nucleotide exchange factor (GEF) for ARF6. Here, we report that two distinct isoforms of the EFA6A gene are expressed in murine neural tissue: a long isoform of 1025 amino acids (EFA6A), and a short isoform of 393 amino acids (EFA6As). EFA6A encompasses proline-rich regions, a Sec7 domain (mediating GEF activity on ARF6), a PH domain, and a C-terminal region with coiled-coil motifs. EFA6As lacks the Sec7 domain, and it comprises the PH domain and the C-terminal region. The transcript encoding EFA6As is the result of alternative promoter usage. EFA6A and EFA6As have distinct biological activities: upon overexpression in HeLa cells, EFA6A induces membrane ruffles, whereas EFA6As gives rise to cell elongation; in primary cortical neurons EFA6A promotes neurite extension, whereas EFA6As induces dendrite branching. Our findings suggest that EFA6A could participate in neuronal morphogenesis through the regulated expression of two functionally distinct isoforms.
Lipin is required for efficient breakdown of the nuclear envelope inCaenorhabditis elegans
Authors: Gorjánácz Mátyás , Mattaj Iain W.
Published: June 2009

The nuclear envelope (NE) is a double lipid bilayer that separates nucleus and cytoplasm. In metazoa, NE breakdown (NEBD) occurs during prophase and NE reformation around segregated chromatids occurs at anaphase-telophase. We identified Caenorhabditis elegans Lipin homologue (called Lpin-1) as an essential factor with roles in endoplasmic reticulum (ER) organization and NEBD. RNAi-mediated downregulation of Lpin-1 had no effect on timely entry into mitosis or on the early steps of NEBD, but Lpin-1 was required for disassembly of the nuclear lamina during late NEBD. This Lpin-1 requirement appears to be separable from the effect of Lpin-1 on the peripheral ER.
Combining regression trees and the finite element method to define stress models of highly non-linear mechanical systems
Authors: Lostado R , Martínez-De-Pisón F J , Pernía A , Alba F , Blanco J
Published: June 2009

This paper demonstrates that combining regression trees with the finite element method (FEM) may be a good strategy for modelling highly non-linear mechanical systems. Regression trees make it possible to model FEM-based non-linear maps for fields of stresses, velocities, temperatures, etc., more simply and effectively than other techniques more widely used at present, such as artificial neural networks (ANNs), support vector machines (SVMs), regression techniques, etc. These techniques, taken from Machine Learning, divide the instance space and generate trees formed by submodels, each adjusted to one of the data groups obtained from that division. This local adjustment allows good models to be developed when the data are very heterogeneous, the density is very irregular, and the number of examples is limited. As a practical example, the results obtained by applying these techniques to the analysis of a vehicle axle, which includes a preloaded bearing and a wheel, with multiple contacts between components, are shown. Using the data obtained with FEM simulations, a regression model is generated that makes it possible to predict the contact pressures at any point on the axle and for any condition of load on the wheel, preload on the bearing, or coefficient of friction. The final results are compared with other classical linear and non-linear model techniques.
Post-buckling of internal-pressure-loaded laminated cylindrical shells surrounded by an elastic medium
Authors: Shen Hui-Shen
Published: June 2009

This paper presents a study on the post-buckling response of an anisotropic laminated cylindrical shell of finite length embedded in a large outer elastic medium and subjected to internal pressure in thermal environments. The surrounding elastic medium is modelled as a tensionless Pasternak foundation reacting in compression only. The governing equations are based on higher-order shear deformation shell theory with von Kármán–Donnell kinematic non-linearity and including extension–twist, extension–flexural, and flexural–twist couplings. The thermal effects are also included, and the material properties are assumed to be temperature dependent. Non-linear prebuckling deformations and the initial geometric imperfections of the shell are both taken into account. A singular perturbation technique is employed to determine the post-buckling response of the shells, and an iterative scheme is developed to obtain numerical results without using any assumption concerning the shape of the contact region between the shell and the elastic medium. Numerical illustrations concern the buckling and post-buckling response of cross-ply and symmetric angle-ply laminated shells surrounded by an elastic medium of tensionless foundation of the Pasternak type, from which results for conventional elastic foundations are obtained as comparators. The results reveal that unilateral constraints have a significant effect on the post-buckling response of shells subjected to internal pressure in thermal environments when the foundation stiffness is sufficiently large.
Transient thermal stress intensity factors of bimaterial interface cracks using refined three-fringe photoelasticity
Authors: Simon B Neethi , Prasath R G R , Ramesh K
Published: June 2009

Transient thermal stresses of a bimaterial specimen with interface edge cracks subjected to heating along an edge is analysed by refined three-fringe photoelasticity (RTFP). Whole-field, noise-free, fringe order estimation using a single colour image is made possible using RTFP combined with colour adaptation. The stress intensity factors (SIFs) of the interface crack are determined through a multiparameter overdeterministic system of equations by a least-squares approach using experimental data collected automatically. The transient SIFs are found to peak to a higher value than in steady state, and the opening mode is found to be dominant. An increase in thermal load causes the crack to propagate, and this is easily visualized on the basis of quantitative fringe order data available for the whole field. The SIFs of a propagating crack are found to be low. The study shows that the crack propagates easily when the opening mode is dominant.
Zero carbon manufacturing facility — towards integrating material, energy, and waste process flows
Authors: Ball P D , Evans S , Levers A , Ellison D
Published: June 2009

The increasing pressure on material availability, energy prices, as well as emerging environmental legislation is leading manufacturers to adopt solutions to reduce their material and energy consumption as well as their carbon footprint, thereby becoming more sustainable. Ultimately manufacturers could potentially become zero carbon by having zero net energy demand and zero waste across the supply chain. The literature on zero carbon manufacturing and the technologies that underpin it are growing, but there is little available on how a manufacturer undertakes the transition. Additionally, the work in this area is fragmented and clustered around technologies rather than around processes that link the technologies together. There is a need to better understand material, energy, and waste process flows in a manufacturing facility from a holistic viewpoint. With knowledge of the potential flows, design methodologies can be developed to enable zero carbon manufacturing facility creation. This paper explores the challenges faced when attempting to design a zero carbon manufacturing facility. A broad scope is adopted from legislation to technology and from low waste to consuming waste. A generic material, energy, and waste flow model is developed and presented to show the material, energy, and waste inputs and outputs for the manufacturing system and the supporting facility and, importantly, how they can potentially interact. Finally the application of the flow model in industrial applications is demonstrated to select appropriate technologies and configure them in an integrated way.
An analytical, numerical, and experimental study of the effect of the parting line position in the forging process of axisymmetric parts with middle elements on one side
Authors: Fatemi A , Biglari F R , Noghabi M A , Dariani B M
Published: June 2009

The effect of parting line position on the forging process parameters and metal flow behaviour is studied in this paper. It is shown that the position of the parting line affects the force and energy of forging, metal flow, and required raw materials. The results of finite element and analytical investigations are compared with experimental results, obtained on three forging dies with different parting line positions. A close agreement between the simulated and experimental results was observed.
Effect of the external pressure on the plastic instability of thin-walled tubes
Authors: Guven U
Published: June 2009

In the present work the effects of an external pressure on the plastic instability and the limit strains of thin-walled tubes are investigated using Swift's criterion. The analysis is based on a plane stress state and the assumptions normally used in this type of study are applied. The effects of three different necking criteria are investigated in the absence of an axial load. The presented results indicate that the application of an external pressure can be advantageous in certain circumstances. It is also shown that the bursting pressure increases with an increase in the external pressure.
Development of a proportional poppet-type water hydraulic valve
Authors: Park S-H
Published: June 2009

To address the environmental problems and the safety of hydraulic systems, the development of novel water hydraulic systems using working fluids such as tap water are being developed successfully. In this study, we aim to develop a proportional water hydraulic valve using a proportional poppet as the main valve, which has an on—off function as well as a proportional function. The proposed proportional poppet-type water hydraulic valve has a simple structure with a control orifice that passes to the pilot orifice at both sides of the conventional poppet. Experiments verified that the relation between the main flowrate and pilot flowrate of the developed valve is linear and that the dynamic characteristics of the proportional poppet are satisfactory. Also, the developed valve was verified to be suitable for pulse width modulation (PWM) control and practical use for the control of water hydraulic systems.
Features of the stress field at the surface of a flush shrink-fit shaft
Authors: Paynter R J H , Hills D A , Barber J R
Published: June 2009

The state of stress induced by a shrink-fitted circular shaft in an elastically similar half-space, positioned so that the end of the shaft is flush with the remainder of the free surface, is studied. At deep interior points the classical plane strain (Lamé) solution obtains, and the transition to the free surface state is found. It is found that a residual interfacial axial shear develops and the coefficient of friction needed to ensure adhesion along the interface is found. The effect of slip when a lower coefficient of friction is present is also found as a solution to an integral equation.
Future trends in railway engineering
Authors: Iwnicki S
Published: June 2009

This article reviews the current state of railway engineering with a focus on the steady development of conventional technology that has led to the 575 km/h run of the French TGV train in 2007. Several key engineering areas are explored and predictions made for future technological developments in vehicle and track design including active suspension, improved aerodynamic performance, and novel track systems such as slab track. Non-conventional technologies such as magnetic levitation are discussed but the conclusion arrived at is that considerable improvements are still possible through optimization and incremental development of conventional engineering solutions and that, in the short to medium term, implementation of radically novel systems is less likely.
Manoeuvring speed of a 6×6 autonomous vehicle using a database obtained from multi-body dynamic simulation
Authors: Cho S-L , Yi K-C , Lee J-H , Yoo W-S
Published: June 2009

For an autonomous vehicle that travels off-road, the driving speed is limited by the driving circumstances. To decide on a stable manoeuvring speed, the driving system should consider road conditions such as the height of an obstacle and road roughness. In general, an autonomous vehicle has many sensors to preview road conditions, and the information gathered by these sensors can be used to find the proper path for the vehicle to avoid unavoidable obstacles. However, sensor data are insufficient for determining the optimal vehicle speed, which could be obtained from the dynamic response of the vehicle. This paper suggests an algorithm that can determine the optimal vehicle speed running over irregular rough terrains such as when travelling off-road. In the determination of the manoeuvring speed, the vehicle dynamic simulation is employed to decide whether the vehicle response is within or beyond the prescribed limits. To determine the manoeuvring speed in real time, the dynamic simulation should be finished much more quickly than the real motion speed of the vehicle. In this paper, the equation of motion of the vehicle is derived in terms of the chassis local coordinates to reduce the simulation time. The velocity transformation technique, which combines the generality of Cartesian coordinates and the efficiency of relative coordinates, was combined with a symbolic computation to enhance further the computational efficiency. First the developed algorithm calculates the level of the previewed road roughness to determine the manoeuvring speed. Then, the maximum stable speed is judged against the database, which already has stored the maximum vertical accelerations as a function of the road roughness and vehicle speed.
Evaluation of the NOx emissions from heavy-duty diesel engines with the addition of cetane improvers
Authors: Nuszkowski J , Tincher R R , Thompson G J
Published: June 2009

The exhaust emissions from heavy-duty diesel engines (HDDEs) contribute to the degradation of ambient air quality; therefore, environmental agencies have created stringent emissions standards. Since the implementation of these standards, overall engine and fuel technology improvements have created a significant reduction in emissions. This study was completed in order to evaluate oxides of nitrogen (NO x) emissions from fuels with and without cetane-improving additives in recent and early production electronically controlled HDDEs. Five engines spanning the model years from 1991 to 2004 were tested using the Federal Test Procedure (FTP) dynamometer cycle with both petroleum-based diesel and B20 as the neat fuel. It was found that the additives had the most impact on reducing emissions at low engine powers, but the engine power range with an NO x benefit varied between engines. The cetane improvers were found only to reduce NO x below a cylinder gas density of 35kg/m3 at top dead centre. The lower compression ratio of the 1992 DDC S60 engines reduced the cylinder gas density and provided a larger optimal operating range for the cetane improvers. The cetane improvers reduced NO x at low engine powers and cylinder gas density for the B20 fuel but were less effective than for the neat petroleum fuels.
Nanoparticle measurements used to detect an engine oil control ring failure
Authors: Swanson J , Ragatz A , Watts W , Kittelson D , Winsor R
Published: June 2009

A cyclic variation in total particle number concentration was observed while making routine exhaust emission measurements. Many dilution and engine operating conditions were examined and, by sequentially shutting down individual cylinders, the problem was traced to cylinder 2. The engine was disassembled and piston 2's oil control ring was found to be fractured. Replacement of the ring eliminated the particle concentration fluctuation. This paper presents the results of experimental measurements made to determine the cause of the irregular emissions.
Experimental study on boiling flow of liquid nitrogen in vertical tubes: Taylor bubble length distribution and rising velocity
Authors: Wang S , Zhang H , Liu Y , Wang J
Published: June 2009

An experimental study was carried out to understand the phenomena of the boiling flow of liquid nitrogen in vertical tubes with closed bottom by using the high speed motion analyser. The tubes in the experiment are 0.014 and 0.018 m in inner diameter, respectively, and both 1.0 m in length. The statistical method is employed to analyse the experimental data. The experiment focused on the study of the nitrogen Taylor bubble length and velocity at different positions along the tubes. The experimental results show that the mean rising velocity of the nitrogen Taylor bubble increases along the tube for two tubes. Near the tube exit, the nitrogen Taylor bubble rising velocity is almost constant. The mean nitrogen Taylor bubble lengths of D=0.014 m are longer than of D=0.018 m, which shows bubbles are easier to coalescence in the small tube. Standard deviation of the nitrogen Taylor bubble length increases with increasing x/ D, which shows the nitrogen Taylor bubble length distribution is more inhomogeneous with increasing x/ D. Standard deviation of the nitrogen Taylor bubble lengths of D=0.014 m are greater than of D=0.018 m. This shows the nitrogen Taylor bubble length range is greater for the small tube.
Performance cycle analysis of an open cooling cycle for a scramjet
Authors: Qin Jiang , Bao Wen , Zhou Weixing , Yu Daren
Published: June 2009

In a conventional regeneratively cooled scramjet, fuel directly enters the combustor after cooling. It is proposed in this article that high-temperature and high-pressure fuel out of the first cooling passage can be used for secondary cooling after expanding through the turbine and transferring enthalpy from fuel to work. A fuel heat sink (cooling capacity) is thus repeatedly used to indirectly increase the fuel heat sink. Instead of carrying excess fuel for cooling or looking for any new coolant, the fuel flow for cooling is reduced, and fuel onboard is adequate to satisfy the cooling requirement for the whole hypersonic vehicle. First are defined cooling and expansion and, second, cooling an open cooling cycle (OCC) for the scramjet. This article provides a brief description of the assessment of the performance potential and scientific feasibility of a scramjet with OCC using fundamental thermodynamic principles. The results show that OCC yields higher performance gain over regenerative cooling, because of the increase in the fuel heat sink and additional power output.
A procedure for the design of radial cascade diffusers based on the maximum ratio between flow deflection and total pressure loss coefficient
Authors: Pavesi G , Cavazzini G , Rossetti A , Ardizzon G
Published: June 2009

A design procedure of radial cascade diffusers for incompressible flow, based on the maximum ratio between the flow deflection and the total pressure loss coefficient, is proposed. To achieve such a result, numerical investigations were carried out on several different diffusers at design and off-design operating conditions. Four space chord ratios, with seven blades and nine outlet flow angles were considered. For each diffuser, the optimum performance parameters were correlated to the incoming flow angle and the design variables of the aerofoil cascade. Reynolds number and mean camberline influence were also analysed. Design charts were then produced in order to attain an efficient preliminary design of aerodynamic diffusers without resorting to time-consuming approaches. Finally, auxiliary charts were proposed for predicting the diffuser performance at off-design operating conditions.
Assessment of economical and ecological benefits from deployment of a domestic combined heat and power unit based on its experimental performance
Authors: Veitch D C G , Mahkamov K
Published: June 2009

A number of technologies have been embarked upon for combating the problems of escalating energy requirements and the resulting greenhouse gas emissions. Micro or domestic combined heat and power (CHP) has been considered to be one of such technologies. Estimation of the benefits from implementing a pre-commercial prototype of a WhisperGen Mk 3, Stirling engine based, micro CHP (MCHP) unit, in a typical UK semi-detached house with high efficiency electrical appliances and with a typical non-condensing boiler was carried out and some of these results are presented in this article. The initial stage of the investigations focused on mapping thermal and electrical operational performance of the MCHP through physical experimentation on the pre-production unit. Then, to estimate the economical and environmental benefits over a 12-month period, the typical heat and power demand profiles within a household were modelled. In the final stage of the research, the operation of MCHP was simulated within the household, taking into account information on heat and electricity demands and data on the experimental performance of the domestic CHP system. The simulation indicated that with the application of this pre-commercial prototype as a replacement for the typical non-condensing boiler a 9 per cent reduction in both utility bills (using electricity and natural gas prices that were effective in March 2005) and CO2 emissions with a seasonal efficiency of 86 per cent could be achieved assuming that no auxiliary heating system was used to rapidly compensate the hot water deficit in the storage tank in periods of the high hot water demand.
CCD-based two-dimensional pneumatic arm control system
Authors: Wang Y-T , Wong R-H , Lo J-H
Published: June 2009

This paper proposes a non-contacted CCD to replace contacted displacement sensors in a two-dimensional (2D) pneumatic arm control system. The CCD is used to capture images which are then transformed to X- Y coordinates that are used as feedback signals. Since the measuring process requires considerable computational effort a self-organizing sliding mode fuzzy controller is proposed to simplify the fuzzy rules and reduce the computer load. The proposed learning mechanism can be used to optimize the fuzzy rules online and improve the control performance. Experimental data is provided on the trajectory tracking performances of the CCD-based and encoder-based 2D pneumatic arms.
Robust stability for uncertain discrete singular systems with time-varying delays
Authors: Wu Z , Su H , Chu J
Published: June 2009

This paper is concerned with the problem of delay-dependent robust stability for uncertain discrete singular systems with time-varying delays. Without introducing the free-weighting matrices to deal with the cross terms, a new and improved delay-dependent condition is established for the nominal systems to be regular, causal, and stable via a new Lyapunov function employing the integrated lower and upper time-delay bounds. The condition is also extended to the uncertain case. A numerical example is given to illustrate that the proposed methods are effective and lead to less conservatism than the existing ones.
Study of mechanical and metallurgical characteristics of flame sprayed NiCrBSi as-sprayed and continuous compacted coating
Authors: Sharma S P , Dwivedi D K , Jain P K
Published: June 2009

Thermal spray processes such as high-velocity oxy-fuel and detonation spraying are more commonly used in industries for depositing coating material as compared to flame spray coatings because of better coating properties (high bond strength, low porosity, and high hardness) offered by the high-velocity flame spraying process. The flame spray coatings are economical but are not frequently used because of coarse microstructure, high porosity, and low-hardness-related problems. The above problems associated with flame spraying can be reduced using innovative techniques like hot isostatic pressing and rolling of coated material at high temperature. Mostly these methods are completed in two stages, which in turn make the post-processing of the coating uneconomical. Therefore, in the present investigation an attempt has been made to integrate the coating deposition and post-processing (compaction) of NiCrBSi coating in one step. In the present work, the NiCrBSi flame sprayed coatings after compaction were compared with as-sprayed coatings in terms of microstructure, porosity, and hardness. Field emission scanning electron microscopy and X-ray diffraction analysis of coatings were also carried out for elemental and phase analysis of its micro-constituents. It was observed that continuous compaction of the flame sprayed coating results in higher hardness, reduced porosity, and finer grain size as compared to that of as-sprayed coating.
Improved infrared temperature mapping of elastohydrodynamic contacts
Authors: Reddyhoff T , Spikes H A , Olver A V
Published: June 2009

An effective means of studying lubricant rheology within elastohydrodynamic contacts is by detailed mapping of the temperature of the fluid and the bounding surfaces within the lubricated contact area.

In the current work, the experimental approach initially developed by Sanborn and Winer and then by Spikes et al., has been advanced to include a high specification infrared (IR) camera and microscope. Besides the instantaneous capture of full field measurements, this has the advantage of increased sensitivity and higher spatial resolution than previous systems used. The increased sensitivity enables a much larger range of testable operating conditions: namely lower loads, speeds, and reduced sliding. In addition, the range of test lubricants can be extended beyond high shearing traction fluids.

These new possibilities have been used to investigate and compare the rheological properties of a range of lubricants: namely a group I and group II mineral oil, a polyalphaolephin (group IV), the traction fluid Santotrac 50, and 5P4E, a five-ring polyphenyl-ether. As expected, contact temperatures increased with lubricant refinement, for the mineral base oils tested.

Using moving heat source theory, the measured temperature distributions were converted into maps showing rate of heat input into each surface, from which shear stresses were calculated. The technique could therefore be validated by integrating these shear stress maps, and comparing them with traction values obtained by direct measurement. Generally there was good agreement between the two approaches, with the only significant differences occurring for 5P4E, where the traction that was deduced from the temperature over-predicted the traction by roughly 15 per cent.

Of the lubricants tested, Santotrac 50 showed the highest average traction over the contact; however, 5P4E showed the highest maximum traction. This observation is only possible using the IR mapping technique, and is obscured when measuring the traction directly. Both techniques showed the effect of shear heating causing a reduction in traction.
Long-term contact-coupled wear prediction for metal-on-metal total hip joint replacement
Authors: Harun M N , Wang F C , Jin Z M , Fisher J
Published: June 2009

The major long-term failure identified for metal-on-UHMWPE is aseptic loosening due to wear generation. Metal-on-metal hip joint replacement has been found to have minimal wear compared to metal-on-UHMWPE. The objective of this study was to apply the computational simulation in predicting wear of metal-on-metal total hip joint replacement. Finite-element model of half ball and the 45° inclined cup was developed to represent the femoral head and acetabular cup, respectively. A simple Archard's equation was used to simulate the wear process combining with the finite-element model. The wear simulation of 28 mm femoral head with 60 μm diametral clearance was carried out for up to 50 million cycles, and subsequently analysed. The contact pressure decreased dramatically from the initial cycle to the first million cycles accompanied by an increase of contact area; however, the decrease of contact pressure was very small between 30 and 50 million cycles. There was relatively good agreement in volumetric wear between the present and hip simulator study. The total predicted volumetric wear for 50 million cycles was 4.2 mm3. It was found that the post-wear bearing surface would be advantageous to the hip implant by increasing the lubricating film and thus decreasing wear.
Effects of solid body temperature on the non-Newtonian thermal elastohydrodynamic lubrication behaviour in point contacts
Authors: Yang P , Liu X
Published: June 2009

In order to investigate the influence of body temperature of contact solids on the lubrication performance of machine components such as gears and roll-bearings, full numerical solution for the non-Newtonian thermal elastohydrodynamic lubrication (EHL) problem in point contacts has been achieved, assuming that the body temperature is different from the temperature of the supplied lubricating oil. The Ree—Eyring rheology model has been used to describe the non-Newtonian behaviour of the lubricant. The effects of the body temperature, the slide—roll ratio, and the velocity parameter have been discussed. The results for the body temperature being higher or lower than the temperature of the supplied oil have been compared with that of the conventional thermal EHL solution, where the temperature of the contact bodies and the temperature of the supplied oil are assumed to be the same. Results show that, if the entrainment velocity is not very high, the solid body temperature plays a dominant role in the EHL behaviour; however, the influence of body temperature decreases as the entrainment velocity increases. Comparisons between the non-Newtonian and Newtonian numerical results have been made under some operating conditions. It has been shown that, compared with the Newtonian solution, the non-Newtonian property of the lubricant can always lead to lower frictional coefficient and lower temperature, but has little effect on the film thickness, no matter the temperature of the contact bodies is lower than, equal to, or higher than that of the supplied oil.
Influence of the bushing geometry on the thermohydrodynamic performance of a misaligned journal bearing
Authors: Mihailidis A , Bakolas V , Panagiotidis K , Poulios K , Sachanas C
Published: June 2009

Often journal bearings have to support shafts that run misaligned into the bushing bore because of the combined effect of elastic deformations and manufacturing tolerances. In such cases, the thermo-hydrodynamic behaviour of the bearing needs to be investigated in detail in order to ensure the safe operation of the device, or, in other words, to avoid asperities contact. The difficulties to model the thermal phenomena comprise one of the main reasons for the limited contribution of theoretical models to the designing efforts. In this article an accurate thermo-hydrodynamic simulation of journal bearings operating under misalignment conditions is introduced at first. Then, the computed film thickness, pressure and temperature distribution, as well as the friction coefficient are shown for several variations of hour-glass profiled bearings operating under a misalignment of up to 5′. From the results shown it can be concluded that the load-carrying capacity of journal bearings can be greatly enhanced if a properly selected hour-glass design is applied. The results show further that a three-dimensional thermo-hydrodynamic analysis, as the one shown here, should always be carried out in order to verify the bushing design.
Eighty years of research on hydraulic reciprocating seals: Review of tribological studies and related topics since the 1930s
Authors: Nikas G K
Published: June 2009

Hydraulic seals are complicated machine elements. The engineering research on hydraulic reciprocating seals, which commenced roughly in the 1930s, has achieved a basic understanding of performance issues. This article provides a review of the experimental and theoretical research conducted over a period of eight decades, discussing more than 200 of the most significant publications from the related literature. The topics discussed include reciprocating seal designs, materials, experimental methods, theoretical studies, elastohydrodynamic lubrication, solid and contact mechanics, performance issues, and optimization.
Experimental and numerical investigation of railroad vehicle braking dynamics
Authors: Mellace C , Lai A P , Gugliotta A , Bosso N , Sinokrot T , Shabana A A
Published: June 2009

One of the important issues associated with the use of trajectory coordinates in railroad vehicle dynamic algorithms is the ability of such coordinates to deal with braking and traction scenarios. In these algorithms, track coordinate systems that travel with constant speeds are introduced. As a result of using a prescribed motion for these track coordinate systems, the simulation of braking and/or traction scenarios becomes difficult or even impossible. The assumption of the prescribed motion of the track coordinate systems can be relaxed, thereby allowing the trajectory coordinates to be effectively used in modelling braking and traction dynamics. One of the objectives of this investigation is to demonstrate that by using track coordinate systems that can have an arbitrary motion, the trajectory coordinates can be used as the basis for developing computer algorithms for modelling braking and traction conditions. To this end, a set of six generalized trajectory coordinates is used to define the configuration of each rigid body in the railroad vehicle system. This set of coordinates consists of an arc length that represents the distance travelled by the body, and five relative coordinates that define the configuration of the body with respect to its track coordinate system. The independent non-linear state equations of motion associated with the trajectory coordinates are identified and integrated forward in time in order to determine the trajectory coordinates and velocities. The results obtained in this study show that when the track coordinate systems are allowed to have an arbitrary motion, the resulting set of trajectory coordinates can be used effectively in the study of braking and traction conditions. The results obtained using the trajectory coordinates are compared with the results obtained using the absolute Cartesian-coordinate-based formulations, which allow modelling braking and traction dynamics. In addition to this numerical validation of the trajectory coordinate formulation in braking scenarios, an experimental validation is also conducted using a roller test rig. The comparison presented in this study shows a good agreement between the obtained experimental and numerical results.
A compact RBF-FD based meshless method for the incompressible Navier—Stokes equations
Authors: Chinchapatnam P P , Djidjeli K , Nair P B , Tan M
Published: June 2009

Meshless methods for solving fluid and fluid-structure problems have become a promising alternative to the finite volume and finite element methods. In this paper, a mesh-free computational method based on radial basis functions in a finite difference mode (RBF-FD) has been developed for the incompressible Navier—Stokes (NS) equations in stream function vorticity form. This compact RBF-FD formulation generates sparse coefficient matrices, and hence advancing solutions will in time be of comparatively lower cost. The spatial discretization of the incompressible NS equations is done using the RBF-FD method and the temporal discretization is achieved by explicit Euler time-stepping and the Crank—Nicholson method. A novel ghost node strategy is used to incorporate the no-slip boundary conditions. The performance of the RBF-FD scheme with the ghost node strategy is validated against a variety of benchmark problems, including a model fluid—structure interaction problem, and is found to be in a good agreement with the existing results. In addition, a higher-order RBF-FD scheme (which uses ideas from Hermite interpolation) is then proposed for solving the NS equations.
Computation of springing transfer functions
Authors: Söding H
Published: June 2009

Ship vibrations excited continually by regular waves are predicted by a potential method. It takes into account the interaction of the oscillatory flow with the steady flow due to the ship's forward speed, including steady ship waves and squat, but it excludes non-linear oscillatory wave forces. A three-dimensional Rankine source patch method is used both for the steady and the oscillatory flow. Vibration damping by an immersed transom, wave radiation, bilge keels, propeller, and hatch cover friction are approximated. Application to a large containership demonstrates that, in this example, damping is mostly attributable to the transom.
Medication Safety: Effect of Medication Reconciliation with and Without Patient Counseling on the Number of Pharmaceutical Interventions Among Patients Discharged from the Hospital
Authors: Karapinar-ÇArkit Fatma , Borgsteede Sander D , Zoer Jan , Smit Henk J , Egberts Antoine Cg , Bemt Patricia Mla Van Den
Published: June 2009

Background

Hospital admissions are a risk factor for the occurrence of unintended medication discrepancies between drugs used before admission and after discharge. To diminish such discrepancies and improve quality of care, medication reconciliation has been developed. The exact contribution of patient counseling to the medication reconciliation process is unknown, especially not when compared with community pharmacy medication records, which are considered reliable in the Netherlands.

Objective

To examine the effect of medication reconciliation with and without patient counseling among patients at the time of hospital discharge on the number and type of interventions aimed at preventing drug-related problems.

Methods

A prospective observational study in a general teaching hospital was performed. Patients discharged from the pulmonology department were included. A pharmacy team assessed the interventions with and without patient counseling on discharge medications for each patient.

Results

Two hundred sixty-two patients were included. Medication reconciliation without patient counseling was responsible for at least one intervention in 87% of patients (mean 2.7 interventions/patient). After patient counseling, at least one intervention (mean 5.3 interventions/patient) was performed in 97% of patients. After patient counseling, discharge prescriptions were frequently adjusted due to discrepancies in use or need of drug therapy. Most interventions led to the start of medication due to omission and dose changes due to incorrect dosages being prescribed. Patients also addressed their problems/concerns with use of the drug, which were discussed before discharge.

Conclusions

Significantly more interventions were identified after patient counseling. Therefore, patient information is essential in medication reconciliation.
Application of the end loaded split and single-leg bending tests to the mixed-mode fracture characterization of wood
Authors: Oliveira Jorge M.Q. , de Moura Marcelo F.S.F. , Morais José J.L.
Published: June 2009

This work describes the application of end loaded split and single-leg bending tests to the mixed-mode fracture characterization of wood. Experimental tests and numerical validation analyses were performed. A new data reduction scheme based on the crack equivalent concept is proposed. The method overcomes the difficulties inherent to these tests, such as crack length monitoring during propagation and influence of clamping conditions. The single-leg bending test is simpler to execute and provided accurate results. The obtained mixed-mode fracture energy is associated with the pure mode values and the obtained trend point to a linear fracture criterion as a candidate to describe the fracture behavior of the Pinus pinaster Ait. wood.
A preliminary study of green production of fiberboard bonded with tannin and laccase in a wet process
Authors: Widsten Petri , Hummer Alfred , Heathcote Carol , Kandelbauer Andreas
Published: June 2009

A gluing method for fiberboard based on laccase-activated tannin and wood fibers was investigated on a laboratory scale. Oxygen consumption measurements showed that hydrolyzable tannins (tannic acid and chestnut tannin) were more reactive toward laccase than condensed tannins from mimosa and quebracho. Wet-process hardboard prepared with laccase and the most reactive tannin, tannic acid, had superior mechanical strength compared to controls and boards made with laccase alone or laccase and other tannins. The other tannins did not improve mechanical properties more than laccase treatment alone. The addition of wax to the tannic acid-laccase formulation improved the dimensional stability of the boards enough for them to comply with industrial standards, although wax had a negative impact on the mechanical properties. The results cannot be directly applied to dry-process medium-density fiberboard (MDF) production; however, the positive effects of tannin and laccase on hardboard properties also warrant investigations on the green chemistry of MDF production.
Ozone pretreatment of lignocellulosic materials for ethanol production: Improvement of enzymatic susceptibility of softwood
Authors: Sugimoto Tomoko , Magara Kengo , Hosoya Shuji , Oosawa Satoshi , Shimoda Takafumi , Nishibori Kozo
Published: June 2009

In order to utilize lignocellulosic biomass as a feedstock for bioethanol, ozone pretreatment was conducted on Japanese cedar sawdust and three other lignocellulosic wastes. Successful lignin degradation was accomplished by ozone pretreatment of the Japanese cedar sawdust and over 90% of polysaccharides were converted to monomeric sugars by enzymatic saccharification. This ozone pretreatment was also effective with other lignocellulosics, such as Hinoki cypress sawdust, lumber and board wastes. Ethanol production by simultaneous saccharification and fermentation of the ozone pretreated Japanese cedar sawdust was also successful. It was shown that ozone pretreatment increases enzymatic susceptibility and enables the production of ethanol from lignocellulosic biomass.
Poisson's ratio of plywood measured by tension test
Authors: Yoshihara Hiroshi
Published: June 2009

In this research, Poisson's ratio of plywood as obtained by a tension test was examined by varying the width of the specimen. The tension tests were conducted on five-plywood of lauan (Shorea sp.) with various widths, and Young's moduli and Poisson's ratios of the specimens were measured. Finite element calculations were independently conducted. A comparison of the experimental results with those of finite element analysis revealed that Young's modulus could be obtained properly when the width of the plywood strip varied. In contrast, the width of the plywood strip should be large enough to determine Poisson's ratio properly.
Synchrotron X-ray microtomography and 3D image analysis of medium density fiberboard (MDF)
Authors: Walther Thomas , Thoemen Heiko
Published: June 2009

The three-dimensional microstructure of a series of laboratory medium density fiberboard (MDF) samples with densities varying from 300 kg m-3 to 1000 kg m-3 was investigated by synchrotron microtomography (SRμCT). After reconstruction and filtering of the volume data, an adapted image analysis was used to extract the structural information about the fiber network at different densities. Information was established on the distribution of intra- and inter-fiber voids, cell-wall material, individual fibers, and fiber bundles. Calculations were performed concerning the surface area towards the ambient void spaces, the number of contacts, and the contact area between selected fibers. Furthermore, the resin distribution on the fibers was investigated and characterized by SRμCT and environmental scanning electron microscopy with stained adhesives. The results presented here allow a new approach to examine the complete wood fiber network of MDFs by automatic image analysis routines.
Elective cesarean delivery at 38 weeks' gestation: Is the timing too early?
Authors: Matsuo Koji , Shimoya Koichiro , Kimura Tadashi
Published: June 2009

No abstract available
Vitamin D receptor genotype BB is associated with higher serum osteocalcin in first pregnancy
Authors: Feuz Jacqueline , Wisser Josef , Heufelder Armin , Joba Werner , Zimmermann Roland , von Mandach Ursula
Published: June 2009

Aim: Serum osteocalcin was shown in a previous study on first trimester pregnant women to correlate with bone density and to distinguish between fast and slow bone losers. The objective of the present study is to examine whether serum osteocalcin is related to vitamin D receptor (VDR) BsmI polymorphism in pregnant women.

Study design: We determined osteocalcin serum levels and VDR BsmI genotype in 97 healthy first trimester pregnant women consecutively recruited during six months.

Results: BB (21%), Bb (38%) and bb (41%) genotypes showed similar osteocalcin serum levels. However, in primigravidas (n=38) the BB genotype was significantly associated with higher mean osteocalcin level (9.67 ng/mL) than the Bb (8.07 ng/mL) and the bb genotype (8.14 ng/mL), respectively (P<0.05). The VDR genotype was the only independent parameter to correlate with serum osteocalcin (P<0.05).

Conclusion: Only primigravidas show in the first trimester a relation between the bone formation parameter serum osteocalcin and the VDR genotype BB which indicates a higher risk of fractures. For further clinical applications serum osteocalcin and VDR genotype should be tested on a cohort of primigravidas including measurements of bone density.