Change In Orientation Angle Research Articles

Derivation of the Orientation Parameters in Built-Up Areas: With Application to Model-Based Decomposition

This paper concerns two polarization orientation parameters of built-up areas derived from the polarimetric synthetic aperture radar (PolSAR) data considering two modeling orthogonal dihedral structures. The first orientation parameter is derived from the well-known circular polarization algorithm with the enrichment of arc distance median filtering using an adaptive neighborhood. The derivation of the second orientation parameter is realized by combining the slope-induced changes in polarimetric orientation angle with the shape-from-shading technique. The combination provides the possibility to measure the incidence angle and the azimuth component of the terrain slopes from the cross-pol SAR intensity image. With reference to the cross scattering model, a doubled cross scattering model (DCSM) is introduced by incorporating the orientation parameters, thus serving to guide the model-based decomposition. Using the DCSM refines the estimation of the cross-pol component by enabling us to further reveal the scattering characteristics of built-up areas. Following a novel criterion, the decomposition is implemented at two layers: one for urban areas and one for nonurban areas. The performance of parameter derivation is demonstrated and evaluated with airborne synthetic aperture radar, uninhabited aerial vehicle synthetic aperture radar, and GF-3 fully PolSAR data over different test sites. The decomposed results are consistent with the reference information provided by the National Land Cover Database 2011 about the land cover classification of test sites and encourage the use of the proposed decomposition scheme for different applications.

Quantifying and Improving Laser Range Data When Scanning Industrial Materials

This paper presents the procedure and results of a performance study of a miniature laser range scanner, along with a novel error correction calibration. Critically, this paper investigates the accuracy and performance of the ranger sensor when scanning large industrial materials over a range of distances. In addition, this paper investigated the effects of small orientation angle changes of the scanner, in a similar manner to which it would experience when being deployed on a mobile robotic platform. A detailed process of error measurement and visualization was undertaken on a number of parameters, not limited to traditional range data but also received intensity and amplifier gain. This paper highlights that significant range distance errors are introduced when optically laser scanning common industrial materials, such as aluminum and stainless steel. The specular reflective nature of some materials results in large deviation in range data from the true value, with mean root mean square error (RMSE) errors as high as 100.12 mm recorded. The correction algorithm was shown to reduce the RMSE error associated with range estimation on a planar aluminum surface from 6.48% to 1.39% of the true distance range.

New insights into orientation distribution of high strength polyacrylonitrile-based carbon fibers with skin-core structure

The continuous changes in orientation angle (OA) across longitudinal sections of high strength polyacrylonitrile-based carbon fibers with circular cross sections were investigated by transmission electron microscopy. A contrast ring was observed in some cross-sections, displaying two contrast zones in the longitudinal section. Two types of OA distribution features were found in the absence or presence of contrast zones. Contrast zones were confirmed as the symbol of the skin-core structure and the boundaries between the skin and core. The high preferred orientation of the basal planes was first identified in the contrast zone, which presented an OA inflexion point (OIP) in the OA plot. The OIP was also detected in the contrast zone for the self-prepared carbon fibers. The OIP and contrast ring shifted towards the core as the preoxidation time increased. For a preoxidation time of 8 h, both the OIP and contrast ring disappeared. A mechanism, based on the stress-induced alignment of the basal planes, was proposed to account for the formation of the OIP.

Large eddy simulations and parameterisation of roughness element orientation and flow direction effects in rough wall boundary layers

ABSTRACTWe conduct a series of large eddy simulations (LES) of turbulent boundary layers over arrays of cuboidal roughness elements at arbitrary orientation angles (non-frontal orientations with the incident flow). Flow response to changing roughness orientation is systematically studied at two ground coverage densities, λp = 0.06 and 0.11. As expected, the effective roughness heights zo measured from LES are higher for λp = 0.11 than for λp = 0.06, although appreciable changes both in zo and wall shear stress (friction velocity) are observed at both ground coverage densities as the roughness orientation angle changes. This suggests the necessity of accounting for detailed rough wall topology (including more information than just λp, λf) when relating rough wall morphology to its aerodynamic properties. To this end, a recently developed analytical rough wall parameterisation is used to predict the aerodynamic properties of the simulated rough surfaces. In this rough wall model, wake interactions among roughness elements are explicitly modelled using the concept of sheltering height and exponential attenuation coefficient. As a result, the parameterisation is responsive to detailed ground roughness arrangements and flow conditions, including roughness height variations, element orientation, incident flow direction, transverse displacements, etc. Model-predicted effective roughness heights, wall stress, mean velocity at the height of the roughness, and in some cases displacement height, are compared against the LES measurements from this study as well as numerical/experiment measurements from other authors. The predictions from the model are found to agree well with the measurements both in trends and in absolute values, thus extending the applicability of the analytical rough wall model to more general surfaces than those previously tested.

A hybrid Bézier based multi-step method and differential quadrature for 3D transient response of variable stiffness composite plates

Three-dimensional (3D) transient analysis of a variable stiffness composite laminated (VSCL) plate with curvilinear fibers is presented. The fiber orientation angle changes linearly with respect to the horizontal coordinate in each layer. Various combinations of arbitrary boundary conditions at edges of the plate are assumed. Layerwise-differential quadrature method (LW-DQM) as an efficient and accurate numerical tool is employed to discretize the obtained governing equations for each layer in the spatial domain. Using the DQM enables one to accurately and efficiently discretize the partial differential equations and also implement the boundary and compatibility conditions in their strong forms. Then, solution of the resulting system of differential equations in the time domain, a novel multi-step method based on the Bézier curves is applied. Much lower computational time of the new multi-step with respect to the Newmark time integration scheme together with numerical stability of the method is presented. Apart from convergence and accuracy of the method, effects of variation in the fiber path, different geometrical parameters and boundary conditions on the transient response of the VSCL plates under dynamic loading are investigated.

Impact behavior of hybrid composite plates dependent on curing and different stacking sequences

Abstract In this study, the drop weight impact response of cured hybrid composite plates has been investigated. Experiments were conducted on two groups of hybrid composite plates. The first group was based on upper and lower surfaces that are made of carbon (c) with the inner plates of glass (g), while for the second group the upper and lower surfaces were examined which are made of glass (g) with the inner plates of carbon (c). The orientation angle of the plates was 0, 15, 30 and 45° and the collision energy was 12 J. Contact forces were obtained and compared for the plates with respect to the different sequence and orientation angles. Peak forces increased for all the sequences and orientation angles. However, the (g-c-c-g) stacking sequence showed a larger sensitivity to an orientation angle change. The deflections decreased for the (c-g-g-c) stacking sequence when the orientation angle increased.

Time-dependent combinatory effects of active mechanical loading and passive topographical cues on cell orientation.

Mechanical stretching and topographical cues are both effective mechanical stimulations for regulating cell morphology, orientation, and behaviors. The competition of these two mechanical stimulations remains largely underexplored. Previous studies have suggested that a small cyclic mechanical strain is not able to reorient cells that have been pre-aligned by relatively large linear microstructures, but can reorient those pre-aligned by small linear micro/nanostructures if the characteristic dimension of these structures is below a certain threshold. Likewise, for micro/nanostructures with a given characteristic dimension, the strain must exceed a certain magnitude to overrule the topographic cues. There are however no in-depth investigations of such "thresholds" due to the lack of close examination of dynamic cell orientation during and shortly after the mechanical loading. In this study, the time-dependent combinatory effects of active and passive mechanical stimulations on cell orientation are investigated by developing a micromechanical stimulator. The results show that the cells pre-aligned by linear micro/nanostructures can be altered by cyclic in-plane strain, regardless of the structure size. During the loading, the micro/nanostructures can resist the reorientation effects by cyclic in-plane strain while the resistive capability (measured by the mean orientation angle change and the reorientation speed) increases with the increasing characteristic dimension. The micro/nanostructures also can recover the cell orientation after the cessation of cyclic in-plane strain, while the recovering capability increases with the characteristic dimension. The previously observed thresholds are largely dependent on the observation time points. In order to accurately evaluate the combinatory effects of the two mechanical stimulations, observations during the active loading with a short time interval or endpoint observations shortly after the loading are preferred. This study provides a microengineering solution to investigate the time-dependent combinatory effects of the active and passive mechanical stimulations and is expected to enhance our understanding of cell responses to complex mechanical environments. Biotechnol. Bioeng. 2016;113: 2191-2201. © 2016 Wiley Periodicals, Inc.

Проблемы разработки методики испытаний неметалли- ческих труб и фитингов и гибких металлических труб на пожаростойкость

Advantages of use of nonmetallic pipes as pipeline systems for drencher and sprinkler wet and dry pipe automatic fire extinguishing installations (AUP) are considered. The analysis of advantage of use of nonmetallic pipes and flexible metal pipes in drencher and sprinkler wet and dry AUP is performed. Regulations for design of pipeline networks consisting of these pipes are provided. Distinctions in methods of fire testing of substances, materials and products for flammability, flame distribution, combustibility, fire resistance and fire endurance are shown. The domestic and foreign stands and methods connected with direct pipe testing for fire endurance are considered in detail. It is noted that the bench equipment, test methods and modes stated in domestic and foreign standards and patents for invention do not answer fully assigned purposes. The dependence of change of sprinkler angular attitude on its weight and console length is considered. It is shown that fire endurance as an integral characteristic allows carrying out an engineering choice of specific pipes and fittings for real fire-hazardous objects. There is reasoned the interconnection of test parameters and wet AUP functioning both in operating and standby conditions (wet or dry) with the pipe condition in the course of their operation (with or without water discharge). Nomenclature and the values of the set of parameters characterizing fire endurance are proved. As a set of parameters characterizing fire endurance, there are proposed the test duration before the depressu-rization of the pipe, temperature of tests, hydraulic or pneumatic pressure and water discharge through the pipe carried out automatically in fixed time after the beginning of the test. Test validation of the nature of the orientation angle change of the sprinkler axis (or a spray) must be given depending on its weight, console length and manner of pipe fastening (sliding or rigid). The criterion for the positive assessment of each test is lack of integrity loss of the test pipes and fittings, and also orientation stability of the sprinkler (or spray) in space (within the possible deflection angle). The special design of the test pipe is offered for the orientation check of sprinkler axis concerning the initial position. The stand is developed for the fire endurance definition of nonmetallic pipes (with and without fittings) and the sequence of performing operations is formulated. For control automation of depressurization there were used various technical means responding to pressure drop, to appearance of water streams or smell (at control by a dry pipe).

Classical crystal formation of dipoles in two dimensions

We consider a two-dimensional layer of dipolar particles in the regime of strong dipole moments. Here we can describe the system using classical methods and determine the crystal structure that minimizes the total energy. The dipoles are assumed to be aligned by an external field and we consider different orientations of the dipolar moments with respect to the two-dimensional plane of motion. We observe that when the orientation angle changes away from perpendicular and towards the plane, the crystal structure will change from a hexagonal form to one that has the dipoles sitting in equidistant rows, i.e. a striped configuration. In addition to calculating the crystal unit cell, we also consider the phonon spectrum and the speed of sound. As the orientation changes away from perpendicular the phonon spectrum develops local minima that are a result of the deformation to the crystal structure.

Improving machined surface textures in avoiding five-axis singularities considering tool orientation angle changes

This paper looks into the irregular machined surface textures appearing in the process of avoiding five-axis singularities using the C-space based tool orientation translation method. At first, the mechanism for the appearances of the irregular surface textures is analyzed. A cutting simulation in VERICUT reveals that irregular surface textures are actually caused by lacking control of the tool orientation angles in the orientation modification process. Realizing that, a modified particle swarm optimization (PSO) is intergraded into the previous tool orientation translation method. In the PSO, the particle evolving equations are redefined and a mutation operation is added. The objective of the PSO is to find an optimal translating vector in the C-space so that the changed tool orientation angles can reach minimum values. In this way, the surface textures can be controlled. Three comparative cutting experiments with fillet endmills are carried out to verify the effect of the proposed method. The experimental results show that: (1) with the tool orientation translation method, the five-axis singular problem can be well avoided; and (2) with the optimal translating vector found by the PSO, the machined surface textures can be greatly improved.

The Challenges of Leaning Forward: Commentary on an article by Vaibhav Kanawade, MD, et al.: "Predictability of Acetabular Component Angular Change with Postural Shift from Standing to Sitting Position".

Accurate acetabular component positioning is important in total hip arthroplasty to maximize an impingement-free range of hip motion. Premature impingement can contribute to edge-loading, altered joint-loading patterns, or a higher risk for prosthetic dislocation. While a safe zone for acetabular component placement as proposed by Lewinnek et al.1 has been generally accepted as a target for limiting the risk of prosthetic dislocation, its application requires the consideration of two measurements—inclination and anteversion—obtained from orthogonal radiographs, rather than a single measure of a three-dimensional component position. Some contemporary studies have raised questions about the ability of surgeons to reliably implant the acetabular component within this safe zone2-4. Other studies have drawn attention to the impact of changing pelvic position on the radiographic appearance of acetabular inclination and anteversion with their associated potential to affect acetabular component positioning during hip arthroplasty procedures5-7. In their study, Kanawade et al. combined clinical and experimental observations to extend our understanding of the impact of pelvic positional change on acetabular spatial orientation. Changes in pelvic tilt and acetabular orientation angle (ante-inclination) were …

A Novel Pathloss Model for Angular and Spatial Dependency of Ultra Wideband Off-Body Radio Channels

In this paper variations in path loss model with respect to distance and orientation of human body for both line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios for ultra wideband off-body communication is experimentally and statistically investigated. Results show that for every 1° change in orientation angle between off-body transmitter and on-body receiver, path loss varies by almost 0.097 dB for LOS case and 0.12 dB for NLOS case. A novel path loss model with respect to distance and angle is also presented in this paper.

Role of Hydrophobic Interaction in Controlling the Orientation of Dicationic Porphyrins on Solid Surfaces

The adsorption orientational behavior of dicationic porphyrins on clay surfaces in various solvents was examined. Addition of aprotic solvents to the aqueous solution containing the clay–porphyrin complex induced a large spectral shift to shorter wavelength. The blue shift turned out to be due to the orientation angle change of porphyrin, which leads to the relaxation of molecular flattening. From dichroic measurements on a waveguide, the orientation of the porphyrin was directly observed and found to be parallel to the clay surface in water and to be at a tilt angle of 68° with respect to the clay surface in DMF. A thermodynamic study of the porphyrin orientation on the clay surface was undertaken. This analysis showed that the parallel orientation of the porphyrin was stabilized mainly by the entropy term, and the tilted orientation was stabilized mainly by the enthalpy term. Furthermore, the effects of different organic solvents on porphyrin orientation on the clay surface were examined, and strong correlation between hydrogen bonding parameters and orientation change was found.

Deflection and free vibration of symmetrically laminated quasi-isotropic thin rectangular plates for different boundary conditions

In this study maximum deflection and free vibration of quasi-isotropic thin rectangular plates that are clamped or simply supported from four edges were examined. The effects of changes in aspect ratio and orientation angle on the results of statical bending and free vibration problems according to the Classical Lamination Plate Theory were parametrically calculated by utilizing the Galerkin Method and the Least Squares Method among Weighted Residuals Methods. Obtained results were compared with the software package ANSYS that conducts analyses through Finite Elements Method (FEM). It is observed that the Galerkin Method yields reasonable results much more rapidly than FEM. It was determined that the effect of changes in orientation angles and aspect ratios of different combination of plates, which were constituted with the alternative arrangement of the lamination angles, on maximum deflection and fundamental natural frequency values is substantial. It was considered that the optimum plates that will properly satisfy different load conditions on the different parts of the structure can be determined with the use of the nondimensional tables prepared with the Galerkin Method in the preliminary design of composite hulls. It is proposed that savings from materials, labor, testing and time can be achieved by this means.

プライ厚の異なるCFRPアングルプライ積層板の非線形力学挙動

This paper evaluates effect of ply thickness on nonlinear mechanical behavior of angle-plied CFRP laminates. To begin with, stress-strain behavior of unidirectional laminates under off-axis tensile loading is obtained. The laminates have exhibited nonlinear mechanical behavior in all off-axis angles investigated. It has been also shown that this nonlinear behavior can be predicted well by the one-parameter plasticity model. Angle-plied CFRP laminates have been manufactured using 16 plies of 0.15 mm thick prepreg ([(+45)4/(-45)4]S) or 48 plies of 0.05 mm thick prepreg ([(±45)12]S). When neighboring plies in same fiber orientation are regarded as one blocked plies for 16-ply laminates, this ply thickness is 12 times thicker than that in 48-ply laminates. Tensile tests have been demonstrated that 48-ply laminates show complicated nonlinear behavior until maximum strain of about 20% and intense fiber-matrix debondings as with interlaminar delamination. An attempt has been made to predict the stress-strain behavior of the angle-plied laminates by the one-parameter plasticity model in conjunction with classical laminate plate theory. The predicted behavior of the 16-ply laminates has agreed well with the experimental results without any modification. As for the 48-ply laminates, the model has predicted comparable results of the nonlinear behavior in large strain region when changes in fiber orientation angle due to deformation of the plate has been also taken into account.

Structural Basis of the Ca2+ Inhibitory Mechanism of Drosophila Na+/Ca2+ Exchanger CALX and Its Modification by Alternative Splicing

The Na(+)/Ca(2+) exchanger CALX promotes Ca(2+) efflux in Drosophila sensory neuronal cells to facilitate light-mediated Ca(2+) homeostasis. CALX activity is negatively regulated by specific Ca(2+) interaction within its two intracellular Ca(2+) regulatory domains CBD1 and CBD2, yet how the Ca(2+) binding is converted to molecular motion to operate the exchanger is unknown. Here, we report crystal structures of the entire Ca(2+) regulatory domain CBD12 from two alternative splicing isoforms, CALX 1.1 and 1.2, exhibiting distinct regulatory Ca(2+) dependency. The structures show an open V-shaped conformation with four Ca(2+) ions bound on the CBD domain interface, confirmed by LRET analysis. The structures together with Ca(2+)-binding analysis support that the Ca(2+) inhibition of CALX is achieved by interdomain conformational changes induced by Ca(2+) binding at CBD1. The conformational difference between the two isoforms also indicates that alternative splicing adjusts the interdomain orientation angle to modify the Ca(2+) regulatory property of the exchangers.

Evaluation of Mechanical Properties of Silk Fiber Reinforced Biodegradable Plastic Composites (Part 2, Analytical Prediction for Stress-Strain Relationships of Silk/PBS Laminates)

In the recent years, natural fiber reinforced composites are expected as alternative materials for traditional fiber reinforced composites. Though many experimental studies on mechanical properties of biodegradable composites have been presented in literature, analytical investigations are rarely reported. In this regard, mechanical properties of silk fiber reinforced poly(butylene succinate) (PBS) biodegradable composite (SF/PBS) laminates are investigated in the present study. In order to investigate the effects of surface treatment of the silk fiber on the mechanical properties of the SF/PBS laminates, four types of surface treatment has been applied to the silk fiber. Tensile tests are conducted on cross-ply laminates and angle-ply laminates. When the silk fibers without sericin are used, tensile strengths and Young's modulus are the highest in all laminate configurations. Stress-strain relations of both cross-ply and angle-ply laminates are predicted by combining the three-parameter plasticity model and the classical laminated plate theory. In the analysis, the properties in unidirectional composite from the generalized method of cells (GMC) micromechanics or experimental results are used. It has been found that it is possible to predict the stress-strain relations for both laminates when the experimentally-obtained properties of unidirectional laminates are used. This implies that nonlinearity caused by damages such as debondings in the unidirectional laminates under off-axis loading should be incorporated in the analysis. It has been also found that it is necessary to consider changes in fiber orientation angle due to deformation of the plates in predicting the stress-strain relation for the angle-ply laminates.

Experimental Study on the Stabilization of Small-Bore Journal Bearings by Controlling Starved Lubrication and Bearing Orientation Angle

Journal bearings are widely used for supporting high-speed rotating machinery, such as turbine, compressor, and HDD spindle, because of their high load carrying capacity, stability, and durability. Recently, the engineering trend is oriented to higher speed and smaller sizes of rotating machinery, and then it is important to enhance stabilities for the small-bore journal bearings. Tilting pad journal bearing is generally used for high-speed rotating machineries because of their advantages of stabilization. However, there are some problems using compact size rotating machineries for their high manufacturing cost and complicated structure. Therefore, it is necessary to enhance the stability of more simple bearings compared with tilting pad bearing in order to use for small-size rotating machinery. This paper describes the stabilization method of the small-bore journal bearing based on the combination mechanism with starved lubrication and orientation angle change. It is found that the stabilization of small-bore journal bearings is improved drastically by hybrid lubrication combining these two kinds of mechanism.

Effects of matrix viscoelasticity on viscous and viscoelastic drop deformation in a shear flow

The deformation of a Newtonian/viscoelastic drop suspended in a viscoelastic fluid is investigated using a three-dimensional front-tracking finite-difference method. The viscoelasticity is modelled using the Oldroyd-B constitutive equation. Matrix viscoelasticity affects the drop deformation and the inclination angle with the flow direction. Numerical predictions of these quantities are compared with previous experimental measurements using Boger fluids. The elastic and viscous stresses at the interface, polymer orientation, and the elastic and viscous forces in the domain are carefully investigated as they affect the drop response. Significant change in the drop inclination with increasing viscoelasticity is observed; this is explained in terms of the first normal stress difference. A non-monotonic change – a decrease followed by an increase – in the steady-state drop deformation is observed with increasing Deborah number (De) and explained in terms of the competition between increased localized polymer stretching at the drop tips and the decreased viscous stretching due to change in drop orientation angle. The transient drop orientation angle is found to evolve on the polymer relaxation time scale for highDe. The breakup of a viscous drop in a viscoelastic matrix is inhibited for smallDe, and promoted at higherDe. Polymeric to total viscosity ratio β was seen to affect the result through the combined parameter βDeindicating a dominant role of the first normal stress difference. A viscoelastic drop in a viscoelastic matrix with matched relaxation time experiences less deformation compared to the case when one of the phases is viscous; but the inclination angle assumes an intermediate value between two extreme cases. Increased drop phase viscoelasticity compared to matrix phase leads to decreased deformation.

132 二次元流路内の角を曲がる流れにおける液晶高分子溶液の流動構造に関する研究(S34-3 複雑流体の流れとその応用(3),S34 複雑流体の流れとその応用)

In this study, we have investigated the flow induced structure of liquid crystalline polymer solution in a flow through a two dimensional channel with a corner. The orientation angle and the dichroism were measured with a laser optical measurement system. The orientation angle had smoothly changed from the upstream of the corner to the downstream. A periodic oscillation in orientation angle was observed in the upstream flow, but it became smaller after the flow direction change. The dichroism also became a bit higher in the downstream region. In spite of no significant change in orientation angle and dichroism, a typical texture was obtained at the downstream region in polarized observation.