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Inclination Angle (inclination + angle)
Selected AbstractsWetting Behavior of Amorphous and Crystalline Silicon Dioxide in Contact with a Silicate Slag Based on FayaliteADVANCED ENGINEERING MATERIALS, Issue 4 2010Christos G. Aneziris In this work the wetting behaviour of amorphous and crystalline silicon dioxide in contact with a silicate slag based on fayalite is demonstrated as a function of contact angles, activation energies of the kinetic stages of wetting. In addition the dynamic adhesion work has been calculated as a function of the inclination angle. The amorphous silicon dioxide in contact with the slag presents lower contact angles accompanied also by higher dynamic adhesion works in comparison to crystalline porous ceramics with the same chemistry. [source] Enhancement of natural convection heat transfer from a vertical heated plate using inclined finsHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 6 2007Masao Fujii Abstract An enhancement technique is developed for natural convection heat transfer from a vertical heated plate with inclined fins, attached on the vertical heated plate to isolate a hot air flow from a cold air flow. Experiments are performed in air for inclination angles of the inclined fins in the range of 30° to 90° as measured from a horizontal plane, with a height of 25 to 50 mm, and a fin pitch of 20 to 60 mm. The convective heat transfer rate for the vertical heated plate with inclined fins at an inclination angle of 60° is found to be 19% higher than that for a vertical heated plate with vertical fins. A dimensionless equation on the natural convection heat transfer of a vertical heated plate with inclined fins is presented. © 2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(6): 334,344, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20168 [source] Fluid flow and heat transfer in the transition process of natural convection over an inclined plateHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 8 2001Katsuo Komori Abstract The present study deals with fluid flow and heat transfer in the transition process of natural convection over an inclined plate. In order to examine the mechanism of the transition process, experiments on the flow and heat transfer were performed for various plate inclination angles in the range of 20 to 75°. The wall temperature and fluid flow fields were visualized using a liquid crystal sheet and fluorescent paint, respectively. The visualization confirmed that separation of a boundary layer flow took place, and the onset point of streaks appeared over the plate wall when the modified Rayleigh number exceeded a characteristic value for each inclination angle. The local Nusselt number in the transition range was proportional to the one-third power of the local modified Rayleigh number. By introducing a nondimensional parameter, a new correlation between visualizations of the flow and temperature fields and heat transfer was proposed. © 2001 Scripta Technica, Heat Trans Asian Res, 30(8): 648,659, 2001 [source] Modelling strain localization in granular materials using micropolar theory: numerical implementation and verificationINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 15 2006Khalid A. Alshibli Abstract Implementation and applications for a constitutive numerical model on F-75 silica sand, course silica sand and two sizes of glass beads compressed under plane strain conditions are presented in this work. The numerical model is used to predict the stress versus axial strain and volumetric strain versus axial strain relationships of those materials; moreover, comparisons between measured and predicted shear band thickness and inclination angles are discussed and the numerical results compare well with the experimental measurements. The numerical model is found to respond to the changes in confining pressure and the initial relative density of a given granular material. The mean particle size is used as an internal length scale. Increasing the confining pressure and the initial density is found to decrease the shear band thickness and increase the inclination angle. The micropolar or Cosserat theory is found to be effective in capturing strain localization in granular materials. The finite element formulations and the solution method for the boundary value problem in the updated Lagrangian frame (UP) are discussed in the companion paper. Copyright © 2006 John Wiley & Sons, Ltd. [source] A note on formulas for localized failure of frictional materials in compression and biaxial loading modesINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 10 2001Matthias Lambrecht Abstract The paper investigates aspects of the localization analysis of frictional materials. We derive closed formulas and diagrams for the inclination angle of critical discontinuity surfaces which develop in homogeneous compression and biaxial loading tests. The localization analysis is based on a Drucker,Prager-type elastoplastic hardening model for non-associated plastic flow at small strains, which we represent in spectral form. For this type of constitutive model, general analytical formulas for the so-called critical hardening modulus and the inclination angle of critical discontinuity surfaces are derived for the plane strain case. The subsequent treatment then specializes these formulas for the analysis of compression and biaxial loading modes. The key contribution here is a detailed analysis of plane strain deformation modes where the localized failure occurs after subsequent plastic flow. The derived formulas and diagrams can be applied to the checking of an accompanying localization analysis of frictional materials in finite-element computations. Copyright © 2001 John Wiley & Sons, Ltd. [source] Application of sandy bed solar collector system for water extraction from airINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 6 2006A. E. KabeelArticle first published online: 13 JAN 200 Abstract Extracting water from air by using sandy bed solar collector system is explored in the current paper. The system is studied theoretically and experimentally to evaluate the performance of the sandy bed impregnated with 30% concentration CaCl2 to produce water from moist air. In addition, the system was investigated at three different tilt angles: 15°, 20° and 25°. The theoretical model was constructed to study the effect of various parameters including solution concentration, and solar radiation intensity on the amount of collected water. Results show that sandy bed is effective for collecting water from moist air. The system can provide up to about 1.2-l fresh water per square meter of glass cover per day. A reasonable agreement between theoretical results and experimental measurements is achieved. Results show also that a slight increase in the system productivity can be generated for 25° inclination angle. Copyright © 2005 John Wiley & Sons, Ltd. [source] Where is the radiation edge in magnetized black hole accretion discs?MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2008Kris Beckwith ABSTRACT General relativistic (GR) magnetohydrodynamic (MHD) simulations of black hole accretion find significant magnetic stresses near and inside the innermost stable circular orbit (ISCO), suggesting that such flows could radiate in a manner noticeably different from the prediction of the standard model, which assumes that there are no stresses in that region. We provide estimates of how phenomenologically interesting parameters like the ,radiation edge', the innermost ring of the disc from which substantial thermal radiation escapes to infinity, may be altered by stresses near the ISCO. These estimates are based on data from a large number of three-dimensional GRMHD simulations combined with GR ray tracing. For slowly spinning black holes (a/M < 0.9), the radiation edge lies well inside where the standard model predicts, particularly when the system is viewed at high inclination. For more rapidly spinning black holes, the contrast is smaller. At fixed total luminosity, the characteristic temperature of the accretion flow increases between a factor of 1.2 and 2.4 over that predicted by the standard model, whilst at fixed mass accretion rate, there is a corresponding enhancement of the accretion luminosity which may be anywhere from tens of per cent to order unity. When all these considerations are combined, we find that, for fixed black hole mass, luminosity and inclination angle, our uncertainty in the characteristic temperature of the radiation reaching distant observers due to uncertainty in dissipation profile (around a factor of 3) is greater than the uncertainty due to a complete lack of knowledge of the black hole's spin (around a factor of 2) and furthermore that spin estimates based on the stress-free inner boundary condition provide an upper limit to a/M. [source] Compton scattering of Fe K, lines in magnetic cataclysmic variablesMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2008A. L. McNamara ABSTRACT Compton scattering of X-rays in the bulk flow of the accretion column in magnetic cataclysmic variables (mCVs) can significantly shift photon energies. We present Monte Carlo simulations based on a non-linear algorithm demonstrating the effects of Compton scattering on the H-, He-like and neutral Fe K, lines produced in the post-shock region of the accretion column. The peak line emissivities of the photons in the post-shock flow are taken into consideration and frequency shifts due to Doppler effects are also included. We find that line profiles are most distorted by Compton scattering effects in strongly magnetized mCVs with a low white dwarf mass and high mass accretion rate and which are viewed at an oblique angle with respect to the accretion column. The resulting line profiles are most sensitive to the inclination angle. We have also explored the effects of modifying the accretion column width and using a realistic emissivity profile. We find that these do not have a significant overall effect on the resulting line profiles. A comparison of our simulated line spectra with high-resolution Chandra/HETGS observations of the mCV GK Per indicates that a wing feature redward of the 6.4-keV line may result from Compton recoil near the base of the accretion column. [source] Colliding stellar wind models with non-equilibrium ionization: X-rays from WR 147MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2007Svetozar A. Zhekov ABSTRACT The effects of non-equilibrium ionization are explicitly taken into account in a numerical model which describes colliding stellar winds (CSW) in massive binary systems. This new model is used to analyse the most recent X-ray spectra of the WR+OB binary system WR 147. The basic result is that it can adequately reproduce the observed X-ray emission (spectral shape, observed flux) but some adjustment in the stellar wind parameters is required. Namely (i) the stellar wind velocities must be higher by a factor of 1.4,1.6 and (ii) the mass loss must be reduced by a factor of ,2. The reduction factor for the mass loss is well within the uncertainties for this parameter in massive stars, but given the fact that the orbital parameters (e.g. inclination angle and eccentricity) are not well constrained for WR 147, even smaller corrections to the mass loss might be sufficient. Only CSW models with non-equilibrium ionization and equal (or nearly equal) electron and ion post-shock temperature are successful. Therefore, the analysis of the X-ray spectra of WR 147 provides evidence that the CSW shocks in this object must be collisionless. [source] A two-dimensional electrodynamical outer gap model for ,-ray pulsars: ,-ray spectrumMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2006J. Takata ABSTRACT A two-dimensional electrodynamical model is used to study particle acceleration in the outer magnetosphere of a pulsar. The charge depletion from the Goldreich,Julian charge density causes a large electric field along the magnetic field lines. The charge particles are accelerated by the electric field and emit ,-rays via the curvature process. Some of the emitted ,-rays may collide with X-ray photons to make new pairs, which are accelerated again on the different field lines and emit ,-rays. We simulate the pair creation cascade in the meridional plane using the pair creation mean-free path, in which the X-ray photon number density is proportional to the inverse square of the radial distance. With the space charge density determined by the pair creation simulation, we solve the electric structure of the outer gap in the meridional plane and calculate the curvature spectrum. We investigate in detail the relation between the spectrum and total current, which is carried by the particles produced in the gap and/or injected at the boundaries of the gap. We demonstrate that the hardness of the spectrum is strongly controlled by the current carriers. Especially, the spectrum sharply softens if we assume a larger particle injection at the outer boundary of the outer gap. This is because the mean-free path of the pair creation of the inwardly propagating ,-ray photons is much shorter than the light radius, so many pairs are produced in the gap to quench the outer gap. Because the two-dimensional model can link both gap width along the magnetic field line and trans-field thickness with the spectral cut-off energy and flux, we can diagnose both the current through the gap and the inclination angle between the rotational and magnetic axes. We apply the theory to the Vela pulsar. By comparing the results with the Energetic Gamma Ray Experiment Telescope (EGRET) data, we rule out any cases that have a large particle injection at the outer boundary. We also suggest the inclination angle of ,inc, 65°. The present model predicts the outer gap starting from near the conventional null charge surface for the Vela pulsar. [source] The effect of stellar rotation on colour,magnitude diagrams: on the apparent presence of multiple populations in intermediate age stellar clustersMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY: LETTERS (ELECTRONIC), Issue 1 2009N. Bastian ABSTRACT A significant number of intermediate age clusters (1,2 Gyr) in the Magellanic Clouds appear to have multiple stellar populations within them, derived from bimodal or extended main-sequence turn-offs. If this is interpreted as an age spread, the multiple populations are separated by a few hundred million years, which would call into question the long-held notion that clusters are simple stellar populations. Here, we show that stellar rotation in stars with masses between 1.2 and 1.7 M, can mimic the effect of a double or multiple population, whereas in actuality only a single population exists. The two main causes of the spread near the turn-off are the effects of stellar rotation on the structure of the star and the inclination angle of the star relative to the observer. Both effects change the observed effective temperature, hence colour, and flux of the star. In order to match observations, the required rotation rates are 20,50 per cent of the critical rotation, which are consistent with observed rotation rates of similar mass stars in the Galaxy. We provide scaling relations which can be applied to non-rotating isochrones in order to mimic the effects of rotation. Finally, we note that rotation is unlikely to be the cause of the multiple stellar populations observed in old globular clusters, as low-mass stars (<1 M,) are not expected to be rapid rotators. [source] Electron gyration modified in the magnetic field tilted to the symmetry species of a crystalline metalPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 8 2006S. Olszewski Abstract When a crystal electron is gyrating in the magnetic field being normal to the crystallographic plane, the calculation of the gyration frequency represents a relatively easy task. The paper approaches a more complicated problem of the gyration frequency in the case when the magnetic field is tilted to the crystallographic axes. The tightly-bound s-electrons in crystal lattices of cubic symmetry are considered as examples. Another problem concerns a metal plate for which the changes of the electron gyration frequency are examined as a function of the inclination angle of the magnetic field with respect to the planar boundaries of that plate. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Development of a biologically inspired locomotion system for a capsule endoscopeTHE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY, Issue 4 2009Daisuke Hosokawa Abstract Background A capsule endoscope has a limited ability to obtain images of the digestive organs because its movement depends on peristaltic motion. To overcome this problem, capsule endoscopes require a propulsion system. Methods This paper proposes a propulsion system for a capsule endoscope that mimics the locomotive mechanism of snails and earthworms. The prototype crawler can elongate and contract itself longitudinally and adhere to a wall via suction cups. Results We investigated the effect of the inclination angle of the propulsion plane, the mucus viscosity between the propulsion plane and the crawler, and the stiffness of the propulsion plane on the locomotion of the prototype crawler. We found that the crawler could move on a rubber sheet and on inclined planes covered with mucus. We discussed advantages and limitations of the prototype crawler compared to the different locomotive systems developed in former studies. Conclusions We believe that the prototype crawler provides a better understanding of the propulsion mechanism for use in the gastrointestinal tract. Copyright © 2009 John Wiley & Sons, Ltd. [source] The chromospherically active binary star EI Eridani: I. Absolute dimensionsASTRONOMISCHE NACHRICHTEN, Issue 1 2009A. Washuettl Abstract We present a detailed determination of the astrophysical parameters of the chromospherically active binary star EI Eridani. Our new radial velocities allow to improve the set of orbital elements and reveal long-term variations of the barycentric velocity. A possible third-body orbit with a period of ,19 years is presented. Absolute parameters are determined in combination with the Hipparcos parallax. EI Eri's inclination angle of the rotational axis is confined to 56°.0 ± 4°.5, ist luminosity class IV is confirmed by its radius of 2.37 ± 0.12 R,. A comparison to theoretical stellar evolutionary tracks suggests a mass of 1.09 ± 0.05 M, and an age of , 6.15 Gyr. The present investigation is the basis of our long-term Doppler imaging study of its stellar surface (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The iron emission line complex of MCG-5-23-16: the long XMMNewton lookASTRONOMISCHE NACHRICHTEN, Issue 10 2006V. Braito Abstract We present the results of the simultaneous XMM- Newton and Chandra observations of the bright Seyfert 1.9 galaxy MCG,5-23-16, which is one of the best known examples of a relativistically broadened iron K, line. We find that: a) the soft X-ray emission is likely to be dominated by photoionized gas, b) the complex iron emission line is best modelled with a narrow and a broad component with a FWHM ,44000 km/s. This latter component has an EW ,50 eV and its profile is well described with an emission line mainly originating from the accretion disk a few tens of gravitational radii from the central black hole and viewed with an inclination angle ,40°. We found evidence of a possible sporadic absorption line at ,7.7 keV which, if associated with Fe XXVI K, resonance absorption, is indicative of a possible high velocity (v , 0.1c) outflow. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Turbulence Transfer Processes in Adiabatic and Condensing Film Flow in an Inclined TubeCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 4 2003R. Würfel Abstract For the description of transfer processes in separated turbulent two-phase flow, knowledge is necessary about interactions at the interface. Particularly experimental studies were performed of the two-phase-friction coefficient, film thickness, entrainment and heat transfer for adiabatic and condensing conditions. Working systems were n-heptane/air, water/air and condensing n-heptane. The measurement of the liquid film thickness was successful with the ultrasonic method and the entrainment was measured with an isokinetic technique. Quantitative connections between hydrodynamic parameters were discussed and compared with literature models. Based on experimental data, special models are proposed. Partly the influence of the mass transfer intensity cannot be neglected for calculation of the two-phase-friction coefficient. For the description of the heat transfer for film condensation in turbulent flow the interface shear stress and the inclination angle of the tube have proved useful. [source] Interdiffusion phenomena in InGaAs/GaAs superlattice structuresCRYSTAL RESEARCH AND TECHNOLOGY, Issue 5 2010B. Sar, kavak Abstract We have studied structural properties of InGaAs/GaAs superlattice sample prepared by Molecular Beam Epitaxy (MBE) using high resolution X-ray diffractometer (HRXRD). Increasing strain relaxation and defect generations are observed with the increasing Rapid Thermal Annealing (RTA) temperature up to 775 °C. The higher temperatures bring out relaxation mechanisms; interdiffusion and favored migration. The defect structure and the defects which are observed with the increasing annealing temperature were analyzed. Firstly, the in-plane and out-of-plane strains after the annealing of sample were found. Secondly, the structural defect properties such as the parallel X-ray strain, perpendicular X-ray strain, misfit, degree of relaxation, x composition, tilt angles and dislocation that are obtained from X-ray diffraction (XRD) analysis were carried out at every temperature. As a result, we observed that the asymmetric peaks especially in asymmetric (224) plane was affected more than symmetric and asymmetric planes with lower polar or inclination angles due to c-direction at low temperature. These structural properties exhibit different unfavorable behaviors for every reflection direction at the increasing temperatures. The reason is the relaxation which is caused by spatially inhomogeneous strain distribution with the increasing annealing temperature. In the InGaAs superlattice samples, this process enhances preferential migration of In atoms along the growth direction. Further increase in the annealing temperature leads to the deterioration of the abrupt interfaces in the superlattice and degradation in its structural properties. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Controlled overturning of unanchored rigid bodiesEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 6 2006Rubén Boroschek Abstract Typical small hospital and laboratory equipment and general supplies cannot be anchored to resist earthquake motions. In order to protect these non-structural components, a common procedure is to provide barriers to restrain overturning of objects on shelves and other furniture. In many cases this option is not available, especially for hospital equipment, because of other functional requirements. This work presents an alternative approach. The method proposed here does not avoid overturning, but controls the direction of overturning by providing an inclination to the support base so that the overturning occurs in a preferential direction towards a safe area. For example, objects on shelves, could overturn towards the inside or a wall, and equipment on tables could overturn away from the edge. In both cases this would not only reduce the damage to the particular items, but reduce the amount of debris on the floor. In order to determine the proper inclination of the base, specific rigid bodies are analytically evaluated for bi-directional excitation obtained from 314 earthquake records, in approximately 7500 cases. For each case, several inclination angles are evaluated. Finally, a parametric curve is adjusted to the data, given a relation between angle of inclination and percentage of controlled overturning cases. In all cases a 7° angle gives more than 98% confidence of controlled overturning. The design expressions were later compared with experimental results obtained on a six-degree-of-freedom shake table; confirming the analytical expressions. Copyright © 2006 John Wiley & Sons, Ltd. [source] Inclined standing contact fatigueFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 7 2003B. ALFREDSSON ABSTRACT An experimental method is presented, in which a sphere is repeatedly pressed against a surface with an inclined contact load. The method is a development of the normally loaded standing contact fatigue test. Experiments are performed for three inclination angles below the angle of friction and the results are compared to those of the normally loaded standing contact fatigue test. The influence of tangential load on endurance limit load, number of cycles to crack initiation, contact mark appearance and crack behaviour in the surface as well as in cut views are evaluated. The surface crack behaviour outside the contact mark is analysed based on the cyclic contact stresses in the test specimen. The trajectories of the largest principal stresses are followed in both the surface view and in the cut view on the symmetry plane. These stress trajectories are compared to the experimental crack results. The connection between the inclined standing contact fatigue cracks and surface distress micro-cracks is also discussed. [source] Fluid flow and heat transfer of opposing mixed convection adjacent to downward-facing, inclined heated platesHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 1 2009Kenzo Kitamura Abstract Experimental investigations were carried out for opposing mixed convective flows of air adjacent to downward-facing, inclined heated plates. The experiments covered the ranges of the Reynolds and modified Rayleigh numbers from ReL=400 to 4600 and RaL*=1.0×107 to 5.4×108, and the inclination angles from ,=15 to 75° from horizontal. The flow fields over the plates were visualized with smoke. The results showed that a separation of forced boundary layer flow occurs first at the bottom edge of the plate, and then the separation point shifts toward upstream with increasing wall heat flux, and finally, reaches the top edge of the plates. It was found that the separations at the bottom and top edges are predicted with a non-dimensional parameter (GrL,*/ReL2.5)=0.35 and 1.0, respectively. The local heat transfer coefficients of the inclined plates were also measured and the results showed that the minimum coefficients appear in the separation region. Moreover, it was revealed that forced, natural, and combined convective flows can be classified by the non-dimensional parameter (GrL,*/ReL2.5). © 2008 Wiley Periodicals, Inc. Heat Trans Asian Res; Pub- lished online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20233 [source] Enhancement of natural convection heat transfer from a vertical heated plate using inclined finsHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 6 2007Masao Fujii Abstract An enhancement technique is developed for natural convection heat transfer from a vertical heated plate with inclined fins, attached on the vertical heated plate to isolate a hot air flow from a cold air flow. Experiments are performed in air for inclination angles of the inclined fins in the range of 30° to 90° as measured from a horizontal plane, with a height of 25 to 50 mm, and a fin pitch of 20 to 60 mm. The convective heat transfer rate for the vertical heated plate with inclined fins at an inclination angle of 60° is found to be 19% higher than that for a vertical heated plate with vertical fins. A dimensionless equation on the natural convection heat transfer of a vertical heated plate with inclined fins is presented. © 2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(6): 334,344, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20168 [source] Fluid flow and heat transfer of natural convection at a slightly inclined, upward-facing, heated plateHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 5 2002Fumiyoshi Kimura Abstract Natural convective flows over upward-facing, inclined plates were investigated experimentally, with an emphasis on the role of opposing flows that appear over the plates inclined slightly from the horizontal line. The flow fields over the plates and the surface temperatures of the heated plates were visualized with both dye and a liquid-crystal thermometry. The results showed that both the descending and ascending flows appeared over the plates when the inclination angles of the plates were less than 15°. The two flows collided with each other at a certain distance from the plate edge, and then detached from the plate to become a thermal plume. It was found that the above distance was determined solely by the inclination angles and was independent of sizes and heat fluxes of the plates. The local heat transfer coefficients of the plates were also measured. The results showed that the heat transfer from the plate was enhanced by the occurrence of the descending flows. © 2002 Wiley Periodicals, Inc. Heat Trans Asian Res, 31(5): 362,375, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10036 [source] Fluid flow and heat transfer in the transition process of natural convection over an inclined plateHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 8 2001Katsuo Komori Abstract The present study deals with fluid flow and heat transfer in the transition process of natural convection over an inclined plate. In order to examine the mechanism of the transition process, experiments on the flow and heat transfer were performed for various plate inclination angles in the range of 20 to 75°. The wall temperature and fluid flow fields were visualized using a liquid crystal sheet and fluorescent paint, respectively. The visualization confirmed that separation of a boundary layer flow took place, and the onset point of streaks appeared over the plate wall when the modified Rayleigh number exceeded a characteristic value for each inclination angle. The local Nusselt number in the transition range was proportional to the one-third power of the local modified Rayleigh number. By introducing a nondimensional parameter, a new correlation between visualizations of the flow and temperature fields and heat transfer was proposed. © 2001 Scripta Technica, Heat Trans Asian Res, 30(8): 648,659, 2001 [source] Modelling strain localization in granular materials using micropolar theory: numerical implementation and verificationINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 15 2006Khalid A. Alshibli Abstract Implementation and applications for a constitutive numerical model on F-75 silica sand, course silica sand and two sizes of glass beads compressed under plane strain conditions are presented in this work. The numerical model is used to predict the stress versus axial strain and volumetric strain versus axial strain relationships of those materials; moreover, comparisons between measured and predicted shear band thickness and inclination angles are discussed and the numerical results compare well with the experimental measurements. The numerical model is found to respond to the changes in confining pressure and the initial relative density of a given granular material. The mean particle size is used as an internal length scale. Increasing the confining pressure and the initial density is found to decrease the shear band thickness and increase the inclination angle. The micropolar or Cosserat theory is found to be effective in capturing strain localization in granular materials. The finite element formulations and the solution method for the boundary value problem in the updated Lagrangian frame (UP) are discussed in the companion paper. Copyright © 2006 John Wiley & Sons, Ltd. [source] Indole ring orientations of Trp189 in the ground and M intermediate states of bacteriorhodopsin as studied by polarized UV resonance Raman spectroscopy,JOURNAL OF RAMAN SPECTROSCOPY, Issue 1-3 2006Kazuhiro Asakawa Abstract Polarized resonance Raman spectroscopy provides a means for orientation analysis of proteins in aligned samples. Previously, we developed a Raman linear intensity difference (RLID) method to determine the orientations of aromatic amino acid side chains in flow-oriented or membrane-bound proteins. In this study, we have applied the RLID method to Trp189 in bacteriorhodopsin (BR), a transmembrane protein that acts as a light-driven proton pump. Among the eight Trp residues in BR, the Raman spectrum of Trp189 has been extracted by subtracting the spectrum of the Trp189 , Phe mutant from that of wild-type BR. By examining the 251.3-nm-exited polarized resonance Raman intensities of two indole ring vibrations of Trp189, the directions of the La and Bb transition moments have been determined with respect the membrane normal in the light-adapted ground state (BR568) and a photo-excited intermediate (M). Comparison of the orientations of the Trp189 indole ring derived from the La and Bb inclination angles has shown that the indole ring slightly but significantly reorients toward the ionone ring of the retinal chromophore in the M intermediate. The reorientation of Trp189 is consistent with the previous observation that helix F, on which Trp189 is located, undergoes an outward tilt and the hydrophobic interaction of Trp189 increases in the M intermediate. The RLID method combined with 251.3 nm excitation and point mutation is useful for detecting even a small reorientation of a targeted Trp residue. Copyright © 2006 John Wiley & Sons, Ltd. [source] Polarized light imaging of white matter architectureMICROSCOPY RESEARCH AND TECHNIQUE, Issue 10 2007Luiza Larsen Abstract Polarized light imaging (PLI) is a method to image fiber orientation in gross histological brain sections based on the birefringent properties of the myelin sheaths. The method uses the transmission of polarized light to quantitatively estimate the fiber orientation and inclination angles at every point of the imaged section. Multiple sections can be assembled into a 3D volume, from which the 3D extent of fiber tracts can be extracted. This article describes the physical principles of PLI and describes two major applications of the method: the imaging of white matter orientation of the rat brain and the generation of fiber orientation maps of the human brain in white and gray matter. The strengths and weaknesses of the method are set out. Microsc. Res. Tech., 2007. © 2007 Wiley-Liss, Inc. [source] Comparison of potential solar electricity output from fixed-inclined and two-axis tracking photovoltaic modules in EuropePROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 1 2008Thomas Huld Abstract We present an approach to determine the potential energy gains of flat plate non-concentrating photovoltaic systems for the case of two-axis tracking and two inclination angles with fixed orientation (assuming biannual adjustment) compared to the configuration of single fixed optimum angle. The calculation is based on the Photovoltaic Geographic Information System (PVGIS), which integrates modelling tools with the pan-European solar radiation database. The results indicate that in the case of a PV system with two seasonal inclination angles, the maximum yearly gains, compared to the single fixed optimum angle, do not exceed 60,70,kWh per kWp in the Mediterranean region, while in the Baltic and North Sea regions this configuration gives less than 20,kWh extra. For the case of two-axis tracking, the relative energy gain compared to single fixed optimum angle is highest in the Northern latitudes but the absolute gain is much higher in the South. Typical yearly gains in Portugal and the Mediterranean region are in the range of 400,600,kWh per kWp. The smallest absolute increase is found in the Northwest and Central Europe including the British Isles, where it is lower than 250,kWh per kWp. For crystalline silicon we also investigate the effects of temperature and shallow-angle reflectivity on the comparison between fixed and tracking systems. While both effects reduce the overall energy output, the temperature degradation is stronger for tracking systems while the reflectivity reduces output more for fixed systems. The combined effect is almost equal for fixed and two-axis tracking systems. Copyright © 2007 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||