Planar Displacement Research Articles

Case History of the Use of Electronic Survey Techniques to Assess Planar Distortions in Building Facades

Abstract The occurrence of distortions within facade elements in the form of leaning, bowed and vertically displaced wall construction is common in older structures. Quite often these conditions are identified by building owners and serve as the primary focus of investigations to assess their significance. Quantifying the severity and extent of these displacements is integral to these evaluations. Various surveying methods are available to assist the investigator in determining planar distortions, ranging from simple plumb bob and level surveys to digital electronic surveying techniques. This paper focuses on the use of electronic surveying techniques as a diagnostic tool in assessing planar distortions and displacement in three dimensions on building facades. A case study is presented as a typical application where planar displacements within a building facade needed to be assessed. To provide context for selection, use, and interpretation of various survey techniques, a project is reviewed in detail from initial identification of displacements, review/selection of an appropriate survey technique, manipulation, and interpretation of survey data, assessing the significance of the data relative to the case study building, and review of repair program parameters.

A Surface Encoder with Dual Sine-grids

This paper describes a new type of surface encoder for planar position measurement, which consists of a sinusoidal grid (target sine-grid) and an optical sensor unit. The optical sensor employs a transparent sine-grid instead of a grid pattern film used in a conventional surface encoder. The transparent sine-grid is generated on a glass plate with the same amplitude and wavelength as the target sine-grid. Simulation results have shown that planar displacement between the two sine-grids can be obtained from the output of the sensor unit. Compared with conventional surface encoder, the new type surface encoder is expected to have higher S/N ratio. Experimental results are also presented.

Three-dimensional texture determination of 6111 aluminium alloy sheet by precise serial sectioning and EBSD measurement

A method of accurate serial sectioning has been designed for three-dimensional texture measurement in aluminium alloy sheet. Using this method, determination of three dimensional texture in an AA6111-T4P sheet has been carried out by electron backscatter diffraction (EBSD) in a scanning electron microscope (SEM) from the sheet surface to 1/3 of the thickness. Optimal conditions for specimen preparation and SEM operation have been investigated to ensure minimum planar displacement or rotation among sections. It has been demonstrated that in the AA6111-T4P sheet the {001}〈100〉 (cube), {011}〈100〉 (Goss) and {011}〈455〉 (P*) orientations are the major texture components. The through thickness averaged cube and Goss components are aligned parallel to the rolling direction forming a banded structure, and the bands of the cube and Goss are distributed alternately in the transverse direction. The variation in grain size is very limited compared with the texture components.

Wafer location integrity in aluminum metallization

Aluminum sticking between wafer and clamp ring is unavoidable during metallization. The non-concentric location of the wafer on the clamp ring may result in awkward drop-off after sputtering; resulting in damage to the wafer. An existing hoop lift and clamp ring design to locate the wafer during sputtering was deemed not to adequately meet complete constraint requirements in relation to kinematic positioning principles. A prototype model hoop lift and clamp ring design that met these requirements was fabricated. In a verification experiment, an optical planar displacement sensing method was used to ascertain the location integrity of the two designs via a repeated placement test. The prototype model hoop lift and clamp ring design was shown to exhibit significantly improved levels of location integrity compared with the original design.

Investigation of metabolism using TLC-DAR and reaction-displacement TLC

Thin-layer chromatography has been used to monitor formaldehyde production during in-vivo metabolism of (−)-deprenyl. Formaldehyde was reacted with dimedone to yield its dimedone adduct, formaldemedone. Determination of 14 C-labeled formaldemedone was performed by planar displacement chromatography. The separated bands were detected either by digital autoradiography or on X-ray film after contact autoradiography. Two-dimensional separations have improved the evaluation.

DISPLACEMENT THIN-LAYER CHROMATOGRAPHY

Thin-layer chromatography has several advantages in comparison to column chromatography, e.g., simultaneous separation of several samples, easy realization of two-dimensional separation, direct observation of both the chromatographic development and the separation using colored compounds, sensitive and easy detection of the spots with specific spray reagents. The entire procedure, i.e., loading, development, and evaluation are relatively simple. An additional feature is the optimization possibilities of mobile phase flow velocity, based on the complexity of driving force where capillarity results in a concave flow profile that may be counterbalanced by convex profile of laminar flow. Displacement thin-layer chromatography has the advantages of planar arrangement of the stationary phase, and opens new possibilities for analytical separations.This paper outlines basic features of planar displacement chromatography, including differences from elution chro-matography, and that of column displacement chromatography, the possibility of using spacer displacement chromatography. Parameters limiting displacement chromatography, and their optimization to achieve better separation are discussed.

Simplified abdominal wall-lifting device for gasless laparoscopy

Objective: To develop a simplified abdominal wall-lifting device for gasless laparoscopy. Methods: The device is composed of an electric-power actuator, sliding arm and abdominal wall-retractor. All parts of the device are reusable. The device provides planar displacement of the anterior abdominal wall to enable space for laparoscopy. The valveless ports and conventional instruments, as well as laparoscopic instruments, were used without a gas leak problem. Results: After preliminary success in the laboratory testing, a petition was made to the hospital's Ethic Committee. Since then we have performed 40 gasless laparoscopic procedures including 13 salpingo-oophorectomies, 10 diagnostic laparoscopies, five tubal ligations, five ovarian cystectomies, four salpingectomies, two removals of pelvic IUDs and one laparoscopic hysterectomy. There were no surgical complications, including no abdominal wall trauma. The operative field was almost the same as that of the pneumoperitoneum technique, with the exception of morbidly obese patients. Conclusions: This preliminary experience demonstrates the efficiency of the simplified abdominal wall-lifting device and the potential advantages of gasless laparoscopy. Continued modifications and applications are necessary to delineate the full range of benefits of this device and technique, especially in developing countries.

Urinary excretion of deprenyl metabolites

(−)-Deprenyl metabolites in rat's urine, such as nordeprenyl, methamphetamine, amphetamine and p-hydroxymethamphetamine were identified by HPLC-MS. After oral administration of 10 mg of pure (−)- and (+)-deprenyl to human volunteers, their urine was analyzed by gas chromatography. The concentration of methamphetamine was found to be overwhelming in the case of the (−)-isomer, while amphetamine and methamphetamine were excreted in equal amounts when (+)-deprenyl was administered. The metabolic processes of deprenyl resulted in metabolites possessing different lipophilicity, as it has been shown by planar displacement chromatography.

Effects of engineering tolerances on the error of a planar capacitance displacement sensor

The paper discusses the effects of manufacturing tolerances on the linearity errors of a planar capacitative displacement sensor. A numerical evaluation is given together with working formulas for the effects of gap taper in the working electrodes, the curvature of the inner edges of these electrons, and taper in the outer edges.

Experimental study on a planar capacitative displacement sensor

An experimental study is described on a planar capacitative displacement sensor. It differs from existing models in being simple and giving scope for using film techniques. The sensor is particularly effective in measuring large displacements, e.g., in physics equipment.

Determination of two-dimensional planar displacement by moiré fringes of concentric-circle gratings

We investigate the moiré fringe pattern of two concentric-circle gratings with the aim of measuring the relative two-dimensional planar displacement induced between the gratings. In the first stage we give a comprehensive mathematical approach for the analysis of fringe patterns. Then we suggest a fast computational measurement algorithm that uses a Fourier transformation technique. Finally, our experimental results prove that a measuring accuracy of 0.01 µm can be achieved with this method.

Mechanical peritoneal retraction as a replacement for carbon dioxide pneumoperitoneum

A fan retractor and a mechanical lifting arm were developed to achieve planar displacement of the anterior abdominal wall for gasless laparoscopic procedures. The technique permits the use of conventional open surgical instruments as well as laparoscopic tools through minilaparotomy incisions. It also potentially addresses the technical constraints imposed by pneumoperitoneum, and physiologic concerns regarding carbon dioxide insufflation. Gynecologic, general surgical, and trauma procedures were performed in 104 patients, with successful completion of 86.5%. Continued application is necessary to delineate the full range of benefits oflaparoscopy without insufflation

Transient elastodynamic analysis of a penny-shaped crack

Transient elastodynamic analysis of a stationary penny-shaped crack in an infinite elastic solid is presented. The analysis is based on a non-hypersingular time-domain boundary integral equation method and is fully three-dimensional. An incident, transient and planar displacement pulse of longitudinal or transverse wave-type is taken as applied loading. A collocation method is used for solving the time-domain boundary integral equations. Constant elements are applied away from the crack front, while special elements called “crack front elements” are adopted near the crack front to describe the local behavior of the unknown quantities properly. By using a linear shape function in time and by invoking the causality and the time-translation properties of Green's functions, an explicit time-stepping scheme is obtained for computing the discrete crack opening displacements at the collocation points, from which the transient dynamic stress intensity factors are subsequently extracted. Numerical results are presented for several cases, to analyze the dynamic overshoot phenomena and the effects of the type and direction of incident transient elastic waves on the time history and the spatial variation of the dynamic stress intensity factors.

Modelling Of Radial Water/Oil Displacement Processes In Water-Wet Porous Media

Abstract Response surface methodologies were used to study the effects of five important variables on oil recovery and finger formation during immiscible radial displacement of oil by water ma consolidated water-wet porous medium. Using a modifiedcentral composite experimental design, the following operating variables were investigated: flow rate of injection fluid, radial distance from injection point, viscosity difference between displaced and displacing phases permeability of porous medium and oil/water interfacial tension. Empirical models based directly on the operating variables and indirectly on pertinent dimensionless terms were developed to describe fractional recovery and number of fingers at breakthrough. The resulting models provide valuable new information about the individual and the joinl effects of the operating variables. Many previously reported ffects were confirmed and quantified under the more rigorous and extensive experimental conditions employed in this paper. Moreover, identification of interactions among operatingariables allowed some discrepancies in previously reported effects to be reconciled. Introduction Of the many enhanced oil recovery schemes, immiscible flooding, including water flooding, is the most widely used. Unfortunately, whenever the mobility ratio, M = (Kw/ μw)/(Ko/ μo), is greater than one, interfacial instabilities can lead to viscous fingering, whereby the displacing aqueous phase tends to flow preferentially through paths of lesser hydrodynamic resistance, leaving large regions of unrecovered oil. Despite its importance to the success of commercial oil recovery operations, fingering remains a relatively poorly understood phenomenon. Most previous displacement studies concerning viscous fingering have used unconsolidated porous media in spite of erious problems with respect to reproducibility of critical factors such as porosity, permeability, wettability and structural heterogeneity. Investigators who have used consolidated porous edia((1, 2)) employed linear flow setups in which it is very difficult to establish an initial planar displacement front. Furthermore, enhanced oil recovery in the field typically employs injection of the displacing fluid a(a point creating an initial radial displacement pattern. To overcome these limitations, adial displacement in a consolidated porous medium consisting of sintered glass beads sandwiched between two parallel glass plates was investigated in the present work(3). Previous analysis of enhanced oil recovery processes(4, 5) has identified the primary factors affecting finger formation and recovery as; flow rate of injection fluid, viscosity difference (or ratio) between the displacing and displaced fluids, permeability of the porous medium, oil/water interfacial tension and breakthrough radius. Typically such studies have been limited to an examination of the individual effects of these variables(1–32). As a result, little information as to the joint or interaction effects exists. Indeed, the physico-chemical processes involved suggest that the effect of anyone of these factors on finger formation and recovery may well depend upon the levels of the other factors. Such information is essential for an improved understanding of enhanced oil recovery. Experimental design and model building techniques for the empirical evaluation of the individual and joint effects of operating variables on a given response have been well described in the literature (Box et al. (33)) and they fall within the domain of response surface methodology.

Synthesis of Planar Mechanisms for Coupler Tangent-Line Envelope Generation: An Alternative to Coupler Point-Path Generation

A synthesis procedure is developed to envelope a given plane curve by a tangent line carried by the coupler plane of a planar four-bar linkage. The synthesis procedure is based on a modification of the planar rigid-body displacement matrix developed by Suh [1]. The approach is based on considering a given curve as the envelope of a moving tangent line and synthesizing mechanisms to envelope the given curve. This is a novel approach in mechanism design and adds a new dimension to the path-generation problem of mechanism synthesis. The foregoing procedure is also extended to synthesize eight-link mechanisms to simultaneously coordinate the motion of two tangent lines. In addition to finite position synthesis, both infinitesimal and mixed position synthesis are considered.

Experimental Errors in the Observation of Body Joint Kinematics

Any planar displacement of a rigid body can be uniquely characterized as a rotation about some fixed axis through a certain angle. These same rotational parameters can also describe the relative motion of two joint components and have been used to describe the rotational behavior of human body joints. This article derives estimates of these parameters and their standard errors, based on geometric arguments for the coordinates of markers observed during the rotation. This in turn identifies optimal placements of the experimental markers, which maximize the precision of the estimated center of rotation and the angle of rotation. This is the first statistical treatment of this problem. Previous approaches used deterministic error structures.

Measurement of strain in silver halide particles by convergent beam electron diffraction

Only limited radiation damage was observed in convergent beam electron diffraction (CBED) patterns obtained at 300 kV with a focussed 10 nm probe from silver halide particles cooled to 100 K. For duplex particles with a coherent interface between the AgBr core and a AgBrI shell, the planar displacements calculated from a spherical isotropic model for the strain field were shown to be consistent with the intensity rocking curves observed in large-angle CBED patterns mapped across a 0.25 micro m particle. A useful analogy with optical Fraunhofer and Fresnel diffraction is the basis for a discussion of the relation between planar displacement and their associated kinematic rocking curves. The sign of the misfit between the core and shell was confirmed by a new method based upon comparison of the elastic and Kikuchi contrast across the boundary of CBED discs.

Austenitization during intercritical annealing of an Fe-C-Si-Mn dual-phase steel

Partial austenitization during the intercritical annealing of an Fe-2.2 pct Si-1.8 pct Mn-0.04 pct C steel has been investigated on four kinds of starting microstructures. It has been found that austenite formation during the annealing can be interpreted in terms of a carbon diffusion-limited growth process. The preferential growth of austenite along the ferrite grain boundaries was explained by the rapid carbon supply from the dissolving carbide particles to the growing fronts of austenite particles along the newly formed austenite grain boundaries on the prior ferrite grain boundaries. The preferential austenitization along the grain boundaries proceeded rapidly, but the austenite growth became slowed down after the ferrite grain boundaries were site-saturated with austenite particles. When the ferrite grain boundaries were site-saturated with austenite particles in a coarse-grained structure, the austenite particles grew by the mode of Widmanstatten side plate rather than by the normal growth mode of planar interface displacement.

Resonant motion of a spherical pendulum

The weakly nonlinear, resonant response of a damped, spherical pendulum (length l, damping ratio δ, natural frequency ω 0) to the planar displacement ε l cos ω t (ε ⪡ 1) of its point of suspension is examined in a four-dimensional phase space in which the coordinates are slowly varying amplitudes of a sinusoidal motion. The loci of equilibrium points and the corresponding bifurcation points in this space are determined. The control parameters are α= 2δ/ε 2 3 and v= 2(ω 2 - ω 2 0/ ε 2 3 ω 2 . If α < 0.441 there is a finite interval of v within which no stable equilibrium points exist. As v decreases through the upper bound (a Hopf-bifurcation point) of this interval the motion in the phase space becomes periodic and then, following a period-doubling cascade, chaotic. There may be alternating sub-intervals of chaotic and periodic motion. The chaotic trajectories in the phase space appear to lie on fractal attractors.

Motion Synthesis Using Kinematic Mappings

This paper studies planar motion approximation problems in the context of a kinematic mapping. Since a planar displacement is determined by three parameters, it can be mapped into a point of a three-dimensional space. A (single-degree-of-freedom) planar motion can, therefore, be represented by a space curve in the space of the mapping and the problem of motion approximation becomes a curve fitting problem in this space. A mapping introduced by Blaschke is used and a general theory for planar motion approximation is developed. The theory is then applied to dimensional synthesis of four-link mechanisms. Furthermore, since the structural error (i.e., the quality of motion approximation) is dependent on the closeness of the fit in the space of the mapping, a general algebraic theory for determining closest fits to points in this space is developed. The theory is illustrated by a numerical example.