Slit Angle Research Articles

A Survey of Galaxy Kinematics toz∼1 in the TKRS/GOODS‐N Field. I. Rotation and Dispersion Properties

We present kinematic measurements of a large sample of galaxies from the Team Keck Redshift Survey in the GOODS-N field. We measure line-of-sight velocity dispersions from integrated emission for 1089 galaxies with median redshift 0.637 and spatially resolved kinematics for a subsample of 380 galaxies. This is the largest sample of galaxies to z ~ 1 with kinematics to date and allows us to measure kinematic properties without morphological preselection. Emission-line widths provide a dynamical measurement for the bulk of blue galaxies. To fit the spatially resolved kinematics, we construct models that fit both line-of-sight rotation amplitude and velocity dispersion. Integrated line width correlates well with a combination of the velocity gradient and dispersion and is a robust measure of galaxy kinematics. The spatial extents of emission and continuum are similar, and there is no evidence that line widths are affected by nuclear or clumpy emission. The measured rotation gradient depends strongly on slit position angle alignment with galaxy major axis, but integrated line width does not. Even for galaxies with well-aligned slits, some have kinematics dominated by dispersion (V/σ < 1) rather than rotation. These are probably objects with disordered velocity fields, not dynamically hot stellar systems. About 35% of the spatially resolved sample are dispersion dominated; galaxies that are both dispersion dominated and bright exist at high redshift but appear rare at low redshift. This kinematic morphology may probe galaxies' evolutionary state. It is linked to photometric morphology in HST ACS images: dispersion-dominated galaxies include a higher fraction of irregulars and chain galaxies, while rotation-dominated galaxies are mostly disks and irregulars. Only one-third of chain/hyphen galaxies are dominated by rotation; high-redshift elongated objects cannot be assumed to be inclined disks.

Evaluation of Stress Intensity Factors in Biaxial Tensile Stress using Thermalelasticity and Photoelasticity

Stress intensity factor K is analyzed by measuring distribution of sum of the principal stresses around slit tip by an infrared stress measuring device. Under the biaxial tensile stress, both K-values of the isotropic materials with slit angle 0° and 45° show there is no influence of the slit angle at Mode I. The tolerance of the measured K-values of the test specimens which are compared with measured K-values by photoelastic method are around 10-20and these increase as applied cyclic load increases. These tolerance can be reduced up to about 8% by modifying measurements. The effectiveness of the thermoelastic stress measurement method to KI value analyzing under biaxial tensile stress was confirmed.

Micro-Bubble Generation by Using Pipe with Slits

Micro-bubbles are very small air bubbles with diameters of the order of less than several tens microns and have become to attract people's concerns rapidly in the past several years due to their wide potential in practical applications to a variety of advanced technologies (e. g. water quality purification, fish culture and sterilization). Their generating technologies are also splendidly developed. However, a complex device and a high power supply are required for conventional microbubble generators. In this study, the compact and low power micro-bubble generator has been developed and the micro-bubbles are generated by the local shear stress in the flow through a pipe with slits. The small bubbles with 40-50μm of the diameter were generated and the micro-bubble generation was affected by the slit angle. Finally in order to verify the applicability of purification system, a floatation experiment was carried out for three models with a different slit angle (θ=30, 60 and 90 deg). The θ=60 deg case shows the superior performance compared to the other models.

Optimal slit orientation for long multi-object spectroscopic exposures

Historically, long-slit spectroscopic observations were carried out using the parallactic angle for the slit orientation if slit loss was an important consideration (either to maximize the signal-to-noise or to do spectrophotometry). This requires periodic realignment of the slit position angle as the parallactic angle changes. This is not possible for multi-slit observations where one slit position angle must be chosen for the entire exposure. Common wisdom suggests using the parallactic angle at the meridian (). In this paper, I examine what the best strategy is for long, multi-slit exposures. I find that in extreme cases (very long exposure time) the best choice is to orient the slit perpendicular to the parallactic angle at the meridian. There are two effects to consider: the increasing dispersion with increasing airmass and the changing angle between the parallactic angle and the slit. In the case of traditional slit orientation, the two effects amplify each other, thus rendering a significant fraction of the observation useless. Using the perpendicular orientation, the two processes work against each other, thus most of the observation remains useful. I will use, as an example, our 8 h Lockman Hole observations using the Keck telescope, but generic methods are given to evaluate a particular observation. I also make the tools available to the community.

Dynamic Stability of Liquid Crystal Depending on Shape of Pixel Edge in the Fringe Field Switching Mode

We studied the voltage–dependent liquid crystal (LC) dynamic stability corresponding to the pixel edge shape in the fringe field switching (FFS) mode. LC dynamics is very unstable near the edge of the pixel slit, where there is a horizontally different field direction compared with the active region, particularly when the slit angle decreases to 3°. Actually, there are strong field competitions near the edge of the pixel slit due to the patterned pixel shape. Also, a dark disclination line (D/L) at the domain boundary is generated with increasing operation voltage and the D/L extends into the active area at a high applied voltage. It is possible to control LC dynamics near the pixel edge by using different pixel edge shapes. In this paper, we propose an advanced edge shape. This shape has no reverse twist region, unlike the conventional structure, and therefore, LC dynamics is very stable near the edge of the pixel slit. This result indicates that a pixel edge shape with no reverse twist is very important in the design of a high-image-quality FFS mode.

압력에 안정한 3분할 FFS 모드의 화소 설계에 관한 연구

We studied the external pressure-stable advanced frnge field switching (FFS) pixel design with 3 slit sructue. In this mode, a patterned pixel slit is partitioned into 3 areas, namely, two edges and a center, where the edge slit angle is larger than the center slit angle. Thus the reverse twist region in the pixel edge is reduced comparing to the conventional FFS mode so that the LC dynamics in this region becomes very stable. And also, when the external pressure is applied to the panel at the high voltage, the disclination lines (DLs) were barely intruded into active area. Therefore, the structure is use for the pen based system such as the tablet personal computer (PC), personal digital asistant (PDA).

A Novel Fringe Field Switching Mode with 3-partition Pixel Slit

We proposed a novel fringe field switching (FFS) liquid crystal (LC) mode with a 3-partition pixel slit. In this mode, a pixel branch is partitioned into 3 areas, namely, two edges and a center, where the edge slit angle is larger than the center slit angle. Thus the reverse twist region in the pixel edge is reduced and the LC dynamics in this region becomes very stable. Also, when an external pressure is applied to the panel at the operating voltage, the disclination line is barely extended into the active area. Consequently, this mode exhibits a high external pressure resistance with a wide viewing angle and is attractive for pen-based touch panels such as personal digital assistants (PDAs) and tablet personal computers (PCs).

10513 小型・低動力マイクロバブル発生装置の開発(熱工学・乱流)

Microbubbles are very small bubbles with diameters of 50μm or less. The important characteristics of microbubbles are their large specific area and small buoyancy and therefore effective dissolution of gas phase and adsorption rate are expected. The utilization of microbubble is useful to improve water environment. Research efforts at a number of institutions have been devoted to development of microbubble generator. However, complex mechanism and high power supply are required for previous microbubble generation devices. In this study, three types of model (slit angle θ=30, 60, 90 deg) were installed in order to develop the compact and low power microbubble generator and microbubbles were generated by pipe with slits. For θ=60 deg, the microbubble generator showed the superior performance in comparison with the other models. It was confirmed that the microbubble generation was affected by the slit angle.

Transmission properties of a single metallic slit: from the subwavelength regime to the geometrical-optics limit.

In this work we explore the transmission properties of a single slit in a metallic screen. We analyze the dependence of these properties on both slit width and angle of incident radiation. We study in detail the crossover between the subwavelength regime and the geometrical-optics limit. In the subwavelength regime, resonant transmission linked to the excitation of waveguide resonances is analyzed. Linewidth of these resonances and their associated electric-field intensities are controlled by just the width of the slit. More complex transmission spectra appear when the wavelength of light is comparable to the slit width. Rapid oscillations associated with the emergence of different propagating modes inside the slit are the main features appearing in this regime.

Flow control around a circular cylinder by internal acoustic excitation

The possible drag reduction and the corresponding variation of the flow field around a circular cylinder are studied in a wind tunnel using flow control with acoustic excitation, which is supplied internally through a slit to the flow over the cylinder. The drag and the lift force acting on the cylinder are evaluated from the measurement of pressure distributions over the cylinder. The results indicate that the drag is reduced about 30% in comparison with a stationary cylinder, when the control parameters are optimized, such as the slit angle, the forcing Strouhal number and the excitation amplitude. The corresponding flow field around the cylinder with and without control is measured by particle image velocimetry. It is found that the wake of the circular cylinder is elongated downstream and the streamwise mean velocity is accelerated on both sides of the cylinder by the influence of acoustic excitation. On the contrary, the velocity fluctuations and the Reynolds stress in the near wake of the cylinder are strongly diminished under acoustic excitation. These variations of the wake flow support the drag reduction observed in the present measurements.

Digital imaging system for assessing posterior capsular opacification: a preliminary report

Purpose: Posterior capsular opacification (PCO) is the commonest complication of cataract surgery. The aim of this work is to develop a system that could be used by primary care practitioners to monitor the progression of PCO using familiar equipment.Methods: A Kodak DCS 100 (Eastman Kodak, Rochester, NY, USA) digital data back, which uses a Nikon F3 body, was connected to the camera port of a Nikon FS‐2 photo slit‐lamp. A fixation stimulus was developed and systematic studies carried out to determine optimum exposure and slit‐lamp settings using patients recruited from the YAG laser capsulotomy clinic at the Royal Eye Unit, Kingston Hospital. In all cases conventional illumination was used. Inter and intraobserver trials were then carried out using observers ranging from a non‐clinician to an experienced ophthalmologist. All images were analysed using ImagePro Plus image processing software prior to statistical analysis.Results: Optimum slit‐lamp parameters were found to be a 45° slit beam angle, 3 mm slit width and 25× magnification. The flash intensity was set to 2. The optimum camera and digital storage unit speed settings were both ISO 200 for fibrotic PCO but 800 and 1600, respectively, for Elschnig pearl type PCO. Intra‐observer repeatability gave ±0.375 mm (95% confidence) variation in fixation. However, initial results from interobserver trials showed significant variability.Conclusions: The current digital assessment system uses a standard piece of consulting room equipment coupled to a digital 35 mm camera. Initial results indicate that it should be suitable for use in monitoring PCO although a more exact measurement protocol is required to reduce interobserver variability. Work is currently underway to complete validation trials and to find suitable image statistics.

812 スリット流による円柱周りの流れの制御と抵抗減少効果に関する研究(GS.8 流体工学2)

The control of vortex shedding from a circular cylinder is studied by introducing a fluctuating flow through a thin slit. The experiments were carried out in a wind tunnel at a Reynolds number 10^4 for various forcing strohal numbers Sf=0〜1.4 and the velocity amplitudes Vr=0〜3. The pressure distributions over a cylinder surface were messured and the drag and lift force coefficients are evaluated. It is found that the drag reduction over 30 percent is produced by this control, when the slit angle is set to θ=90° and the Strouhal number is larger than 0.6.

Formula for the asymmetric diffraction peak profiles based on double Soller slit geometry

The asymmetric diffraction peak profiles and peak shift of conventional powder diffractometry systems caused by the angular divergence along the vertical axis are reproduced by asymmetrized peak profile functions. The asymmetrization is achieved by convoluting the angular dispersions of both incident and scattered beams along the vertical axis. A general method for mapping vertical window functions to the horizontal direction is proposed, and the formulas of two types of horizontal window functions mapped from symmetric double vertical Bartlett (triangular) and Gaussian window functions are presented. Both formulas incorporate a single asymmetry parameter connected with the open width of the Soller slits along the vertical direction. When experimental diffraction peak profiles are fitted by asymmetrized pseudo-Voigt functions, the asymmetry parameter gives good coincidence with the Soller slit angle, which is clearly specified in a given diffractometer.

有限長スリットからの空気の垂直噴射を伴う３次元超音速流れと混合

The supersonic flow and mixing fields with a perpendicular air injection from a finite length slit are investigated. Two slit angle cases of 90 and 45 degrees are examined. The experiments and the calculations are performed. In the calculations, the mixing fields can be discussed because the main flow air is treated with the equation different from the one of the injected air. The numerical results agree well with the experimental ones qualitatively and quantitatively. The results of the 90 degrees slit angle case show that the flow and mixing field is three-dimensional because of the existence of the slit ends, even if the slit is fairly long. As regards the 45 degrees case, the fields are more three-dimensional and complicated. All the results show that a part of the main flow which gets into downstream side of the slit influences on the mixing in the higher order than the vortex in the vicinity of the slit ends.

Interacting binary galaxies. 7: Kinematic data for 12 disturbed ellipticals

view Abstract Citations (14) References (38) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Interacting Binary Galaxies. VII. Kinematic Data for 12 Disturbed Ellipticals Borne, Kirk D. ; Balcells, Marc ; Hoessel, John G. ; McMaster, Matthew Abstract We have analyzed long-slit spectroscopic data for a sample of 12 tidally disturbed elliptical galaxies. The spectra were obtained with the KPNO 4 m RC spectrograph. Rotation curves and velocity dispersion profiles have been measured at a variety of position angles in these galaxies and have been used to analyze the dynamical response and internal kinematics of stellar systems involved in strong gravitational encounters. We have confirmed with these data our previous observation that such galaxies often reveal U-shaped "rotation" profiles, indicative of a strong resonant tidal effect among those stars that are moving prograde with respect to the galactic encounter. Additional kinematic peculiarities, including U-shaped and W-shaped velocity dispersion profiles, are also revealed in these data. The observed morphologies of the tidal features seen in some of the sample galaxies are consistent with the idea that elliptical galaxies often contain an embedded disk component. Our velocity profiles along new position angles confirm the validity of tidal interaction models that we previously derived for specific pairs in our sample using only a single slit position angle per galaxy. Additional insight into possible refinements of those collision models has also resulted from this study. Publication: The Astrophysical Journal Pub Date: November 1994 DOI: 10.1086/174796 Bibcode: 1994ApJ...435...79B Keywords: Elliptical Galaxies; Galactic Rotation; Interacting Galaxies; Kinematics; Stellar Motions; Stellar Systems; Tides; Velocity Distribution; Astronomical Models; Astronomical Spectroscopy; Spectrographs; Spectroscopic Telescopes; Velocity Measurement; Astrophysics; GALAXIES: INTERACTIONS; GALAXIES: KINEMATICS AND DYNAMICS full text sources ADS | data products NED (19) SIMBAD (15) Related Materials (6) Part 1: 1984ApJ...287..503B Part 2: 1988ApJ...330...38B Part 3: 1988ApJ...330...51B Part 4: 1988ApJ...330...61B Part 5: 1988ApJ...333..567B Part 6: 1989ApJ...336..655B

An Analysis of the Effect of Different Instrumental Conditions on the Shapes of X-ray Powder Line Profiles

Abstract In this investigation we have examined how the full width at half maximum intensity (FWHM) and asymmetry of x-ray powder diffraction line profiles are influenced by the instrumental conditions adopted. Experimental x-ray data has been collected for a matrix of instrumental conditions by systematically varying the divergence slit angle (and the corresponding anti-scatter slit) over the range 0.25° to 1.25°, by using either a 0.05mm or 0.2mm receiving slit, or by removing the diffracted beam Soller slit. The line profile Standard Reference Material, SRM, 660 (LaB6) was used as the powder specimen in that it imparts minimal specimen induced broadening to the diffraction profiles. X-ray data were collected on a conventional, divergent beam, x-ray diffractometer using CuKα radiation. The FWHM of the CuKα1 component can be as low as 0.035°2θ for high resolution conditions, but is normally ∼0.1°2θ at 2θ ≈ 30° for the instrumental conditions adopted in routine diffractometry. Below 2θ = 50°, the divergence slit has a significant effect on the FWHM and is the major cause of the increase in FWHM with decreasing 2θ. Results are presented of the 2θ dependence of FWHM values for each of the instrumental conditions recorded. A general relationship for the 2θ dependence of the FWHM and the asymmetry has been investigated to supersede the inappropriate Cagliotti expression frequently used in x-ray Rietvcld refinement.

Effect of anisotropy and slit angle to the fatigue crack propagation of S14 silicon steel sheet.

Recently, generators and moters undergo higher rotating velocity and frequent stop and start. As the result, the roter receives an alternating high centrifugal force. In this paper, the fatigue crack propagation behavior of S14 silicon steel sheet was investigated, because it is usually used as the iron core of roter. The following results are obtained: Under the mode I condition, no effect of anisotropy appears to the fatigue crack propagation behavior. On the other hand, the effect of anisotropy appears under the mode I and II complex conditions, and it becomes more remarkable as the increase of the mode II component. The reason seems to be based on the discrepancy of the real crack propagation direction and the weakest direction to the fatigue crack propagation resistance which is caused by roll.

Experimental study of free vibration of clamped rectangular plates with straight narrow slits.

The real-time technique of time-averaged holographic interferometry is applied to determine the natural frequencies and corresponding mode shapes of clamped rectangular plates with straight narrow slits, and the effect of the lengths, positions and inclination angles of slits on the natural frequencies and corresponding mode shapes is investigated. Four types of slit locations for a slit parallel with respect to the sides of a plate and a slit having various inclination angles with respect to the longer sides are considered. The natural frequencies obtained experimentally are expressed in terms of a dimensionless frequency parameter, and the results are shown graphically as a function of dimensionless slit length and inclination angle. Several interesting findings are made.

Crack initiation from a sharp notch and stretched zone

The “crack tip COD” at the fracture initiation mainly consists of the stretched zone, the new surface which appeared due to the slip deformation at the notch tip. Therefore, the COD or the stretched zone width at the fracture initiation is a very important parameter which reflects the notch tip behavior until fracture initiation. In the case of fibrous crack initiation, the stretched zone width ( S i ) and COD ( δ i ), where δ i ≈ √2 S i , take almost constant values regardless of temperature, specimen geometry, preloading (if the total δ i is taken), slit angle (in the case of mixed mode condition) and so on, while, in the case of cleavage fracture initiation, COD and the stretched zone width take various values between the value at the fibrous crack initiation ( δ i or S i ) and almost zero, depending on temperature and plastic constraint.

Defocusing correction for the measurement of preferred orientation

A method utilizing textural symmetry is described for establishing the defocusing correction in the Schulz reflection technique of pole figure analysis. An offset specimen is necessary for this determination and sample material identical to that under study is used. This avoids certain difficulties associated with the conventional textureless specimen procedure. The new method is compared with the earlier method in studies of copper, and changes in the defocusing function with receiver slit width and Bragg angle are evaluated. Factors affecting the choice of specimen orientation are examined for the case of orthotropic symmetry.