scholarly journals A Novel Method for Measurement of the Refractive Indices of Transparent Solid Media Using Laser Interferometry

2022 ◽  
Vol 60 (1) ◽  
pp. 51-55
Author(s):  
Arnab Pal ◽  
Pradipta Panchadhyayee ◽  
Kriti R. Sahu ◽  
Debapriyo Syam
Keyword(s):  
Laser Interferometry ◽  
Refractive Indices ◽  
Solid Media ◽  
Novel Method

scholarly journals Ultrathin complex oxide nanomechanical resonators

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
D. Davidovikj ◽  
D. J. Groenendijk ◽  
A. M. R. V. L. Monteiro ◽  
A. Dijkhoff ◽  
D. Afanasiev ◽  
...  
Keyword(s):  
Mechanical Response ◽  
Structural Phase ◽  
Laser Interferometry ◽  
Complex Oxide ◽  
Nanoelectromechanical Systems ◽  
Nanomechanical Resonators ◽  
Mechanical Coupling ◽  
Novel Method ◽  
Mechanical Dissipation ◽  
Oxide Membranes

Abstract Complex oxide thin films and heterostructures exhibit a variety of electronic phases, often controlled by the mechanical coupling between film and substrate. Recently it has become possible to isolate epitaxially grown single-crystalline layers of these materials, enabling the study of their properties in the absence of interface effects. In this work, we use this technique to create nanomechanical resonators made out of SrTiO3 and SrRuO3. Using laser interferometry, we successfully actuate and measure the motion of the nanodrum resonators. By measuring the temperature-dependent mechanical response of the SrTiO3 resonators, we observe signatures of a structural phase transition, which affects both the strain and mechanical dissipation in the resonators. Here, we demonstrate the feasibility of integrating ultrathin complex oxide membranes for realizing nanoelectromechanical systems on arbitrary substrates and present a novel method of detecting structural phase transitions in these exotic materials.

Measurement of Velocity-Dependent Adhesive Force Exerted on Magnetic Disk Using Micro-Probe of SPM

2003 ◽  
Vol 125 (4) ◽  
pp. 842-849 ◽  
Author(s):  
Yasunaga Mitsuya ◽  
Yasuji Ohshima
Keyword(s):  
Transient Response ◽  
High Speed ◽  
Fringe Pattern ◽  
Ccd Camera ◽  
Target Surface ◽  
Laser Interferometry ◽  
Adhesive Force ◽  
Magnetic Disk ◽  
Novel Method ◽  
Separation Force

A novel method for measuring the velocity-dependent adhesive force exerted on a magnetic disk has been developed using the micro-probe of a scanning probe microscope (SPM). The deformation of a cantilever having a diamond tip was measured based on the Michelson laser interferometry, wherein an interference fringe pattern was formed over the cantilever. The fringe images were captured by an ultra-high speed CCD camera, and then the deformation of the cantilever was accurately captured through image processing for extracting ridgelines from the fringe pattern. The high-speed camera enabled observation of the fringe image variation while the tip was being separated from a target surface, and identification of the transient response of the cantilever arising after separation by using the regression analysis. Then, the separation instant and the separation force were identified as the values of the initial condition of the transient response. Finally, this novel method was applied to the measurement of the separation force exerted on a magnetic disk coated with a molecularly thin lubricant film. As a result, the separation force was found to be approximately proportional to the square root of the retractive velocity.

scholarly journals Measurement of Bond Strength at Metal/Ceramic Interfaces

1989 ◽  
Vol 153 ◽  
Author(s):  
Gerald L. Nutt ◽  
William Lai ◽  
Kenneth E. Froeschner ◽  
Wayne E. King
Keyword(s):  
Bond Strength ◽  
Laser Interferometry ◽  
Surface Velocity ◽  
Free Surfaces ◽  
Planar Shock ◽  
Metal Ceramic ◽  
Novel Method ◽  
Bond Strengths ◽  
Ceramic Interfaces ◽  
Debonding Process

AbstractWe report on a novel method for measuring the bond strength of metal/ceramic interfaces. Test specimens are created by vapor depositing a metal film on a ceramic substrate. The specimen is impacted with a thin metal flyer sending a short planar shock pulse into the ceramic. If the shape and amplitude of the wave is properly controlled the interface will spontaneously debond creating new free surfaces.Measurements indicate the debonding process occurs in less than 1.0 ns, which we believe is too short for crack propagation along existing flaws. Therefore, we conclude that simultanious breaking of atomic bonds rather than propagation and coalescence of cracks is the means by which the film and substrate are separated. The free surface velocity of the metal overlayer is monitored during spall by laser interferometry. The data constitute a direct measurement of the bond strength. The measured bond strengths are reproducible and do not show a dependence on shock amplitude for identically prepared specimens.

Laser interferometry measurements based calibration and error propagation identification for pose estimation in mobile robots

Robotica ◽  
2013 ◽  
Vol 32 (1) ◽  
pp. 165-174 ◽  
Author(s):  
Paulo A. Jiménez ◽  
Bijan Shirinzadeh
Keyword(s):  
Mobile Robots ◽  
Pose Estimation ◽  
Error Propagation ◽  
Laser Interferometry ◽  
Error Variance ◽  
Calibration Method ◽  
Novel Method ◽  
Position And Orientation ◽  
Odometry Calibration ◽  
Two Parameter

SUMMARYA widely used method for pose estimation in mobile robots is odometry. Odometry allows the robot in real time to reconstruct its position and orientation from the wheels' encoder measurements. Given to its unbounded nature, odometry calculation accumulates errors with quadratic increase of error variance with traversed distance. This paper develops a novel method for odometry calibration and error propagation identification for mobile robots. The proposed method uses a laser-based interferometer to measure distance precisely. Two variants of the proposed calibration method are examined: the two-parameter model and the three-parameter model. Experimental results obtained using a Khepera 3 mobile robot showed that both methods significantly increase accuracy of the pose estimation, validating the effectiveness of the proposed calibration method.

scholarly journals A novel shock tube with a laser–plasma driver

2017 ◽  
Vol 35 (4) ◽  
pp. 610-618 ◽  
Author(s):  
Y. Kai ◽  
W. Garen ◽  
T. Schlegel ◽  
U. Teubner
Keyword(s):  
Shock Wave ◽  
High Pressure ◽  
Wave Propagation ◽  
Initial Conditions ◽  
Optical Breakdown ◽  
Laser Interferometry ◽  
Aluminum Film ◽  
Glass Capillary ◽  
Sudden Appearance ◽  
Novel Method

AbstractA novel method to generate shock waves in small tubes is demonstrated. A femtosecond laser is applied to generate an optical breakdown an aluminum film as target. Due to the sudden appearance of this non-equilibrium state of the target, a shock wave is induced. The shock wave is further driven by the expanding high-pressure plasma (up to 10 Mbar), which serves as a quasi-piston, until the plasma recombines. The shock wave then propagates further into a glass capillary (different square capillaries with hydraulic diameter D down to 50 µm are applied). Shock wave propagation is investigated by laser interferometry. Although the plasma is an unsteady driver, due to the geometrical confinement of the capillaries, rather strong micro shocks can still propagate as far as 35 times D. In addition to the experiments, the initial conditions of this novel method are investigated by hydrocode simulations using MULTI-fs.

scholarly journals Novel Method for Processing Respiratory Specimens for Detection of Mycobacteria by Using C18-Carboxypropylbetaine: Blinded Study

1998 ◽  
Vol 36 (7) ◽  
pp. 1996-2003 ◽  
Author(s):  
Charles G. Thornton ◽  
Kerry M. MacLellan ◽  
Thomas L. Brink ◽  
Denise E. Lockwood ◽  
Mark Romagnoli ◽  
...  
Keyword(s):  
Liquid Culture ◽  
Contamination Rate ◽  
Human Pathogens ◽  
Solid Media ◽  
Blinded Study ◽  
Culture Sensitivity ◽  
Aggregate Culture ◽  
Novel Method ◽  
Culture Positive ◽  
Respiratory Specimens

A novel method for processing respiratory specimens to improve culture and acid-fast staining of mycobacteria is introduced. This new method utilizedN,N-dimethyl-N-(n-octadecyl)-N-(3-carboxypropyl)ammonium inner salt (Chemical Abstract Service no. 78195-27-4), also known as C18-carboxypropylbetaine (CB-18). In a blinded, five-center study, CB-18-based processing was compared to the standard method combining NALC and NaOH (NALC/NaOH). A total of 573 respiratory specimens were tested. Individual specimens were split approximately equally; the host institutions processed half of each specimen by the NALC/NaOH method, while the other half was processed with CB-18 at Quest Diagnostics—Baltimore. A total of 106 specimens were culture positive for acid-fast bacilli (AFB). Replacement of the primary decontamination agent with CB-18 caused changes in all diagnostic parameters. Aggregate culture sensitivity improved by approximately 43% (P < 0.01), and smear sensitivity improved by approximately 58% (P < 0.01). The sensitivity of smear relative to that of M. tuberculosis isolates exceeded 93% (P < 0.01) when specimens were processed with CB-18. The average times to a positive result were reduced by 7.3 days in liquid culture (P < 0.01) and 5.3 days on solid media (P < 0.05); however, the CB-18 method had a 20.8% contamination rate in liquid culture versus a rate of approximately 7.5% with NALC/NaOH processing. There were also unusual reductions in liquid culture sensitivity and smear specificity among CB-18-processed specimens. The characteristics of the latter parameters suggested that refinement of the CB-18 processing method should allow further improvements in culture sensitivity. This study showed that the CB-18 method has the potential to improve both smear and culture detection for these important human pathogens.

scholarly journals Novel method to measure the soil clay’s permeability by laser interferometry

2014 ◽  
Vol 11 ◽  
pp. 02010 ◽  
Author(s):  
H. Asselman ◽  
A. Daouidi ◽  
K. Draoui ◽  
A. Asselman
Keyword(s):  
Laser Interferometry ◽  
Novel Method

scholarly journals Study of a novel method to assist in early reporting of sepsis from the microbiology laboratory

2010 ◽  
Vol 4 (12) ◽  
pp. 822-827 ◽  
Author(s):  
Purabi Barman ◽  
Sharmila Sengupta ◽  
Shefali Singh
Keyword(s):  
Blood Culture ◽  
Positive Blood Culture ◽  
Turnaround Time ◽  
Culture Broth ◽  
Microbiology Laboratory ◽  
Biochemical Tests ◽  
Automated Method ◽  
Solid Media ◽  
Disk Diffusion Testing ◽  
Novel Method

Introduction: Microbiology laboratories must provide accurate blood culture reports with rapid turnaround time (TAT) to effectively manage patients with sepsis. In this study three methods are compared for reporting blood culture results: a manual method that included use of a serum separator tube (SST),   the conventional manual, and an automated method for identification and susceptibility (ID/AST). Methodology: Broth from positive blood culture bottles was added to an SST and then centrifuged. The pellet obtained was used to directly inoculate biochemical tests for identification and agar plates for AST on the first day of positivity. Biochemicals and AST plates were read the next day and final results reported on the second day at 24 hours. For conventional disk diffusion testing, the newly positive blood culture broth was also inoculated on solid media on the first day and incubated overnight. The next day AST by was performed as well as biochemical tests from pure colonies. These colonies were also used to inoculate panels for ID/AST using the automated MicroScan 40SI System. These results were recorded on the third day and results reported at 48 hours. Results: The study included 851 samples Out of 106 (12.4%) positive blood cultures, 102 were included in the study; Comparison of the 3 methods showed good correlation. Identification was correctly reported in 95 (93.1%) isolates. The overall AST error rate was 3.8%, Conclusions: The use of SST and direct from pellet inoculation reduced TAT for identification and AST results between 18 and 24 hours.

The spindle stage: A powerful optical tool

1988 ◽  
Vol 46 ◽  
pp. 52-53
Author(s):  
Mickey E. Gunter ◽  
F. Donald Bloss
Keyword(s):  
Significant Error ◽  
Optical Data ◽  
Refractive Indices ◽  
Axis Of Rotation ◽  
Polarizing Microscope ◽  
Microscope Stage

A single, reasonably homogeneous, nonopaque 30-to-300 μm crystal, mounted on a spindle stage and studied by immersion methods under a polarizing microscope, yields optical data frequently sufficient to identify and characterize a substance unequivocally. The data obtainable include (1) the orientation of the crystal's principal vibration axes and (2) its principal refractive indices, to within 0.0002 if desired, for light vibrating along these principal vibration axes. Spindle stages tend to be simple and relatively inexpensive, some costing less than $50. They permit rotation of the crystal about a single axis which is parallel to the microscope stage. This spindle or S-axis is thus perpendicular to the M-axis, namely the microscope stage's axis of rotation.A spindle stage excels when studying anisotropic crystals. It orients uniaxial crystals within minutes and biaxial crystals almost as quickly so that their principal refractive indices - ɛ and ω (uniaxial); α, β and γ (biaxial) - can be determined without significant error from crystal misorientation.

Ultrastructure and Morphology of the Neurospora Crassa Cell Wall Mutants, Slime And Slime X, Using Tem and Sem

1976 ◽  
Vol 34 ◽  
pp. 54-55
Author(s):  
Karen S. Howard ◽  
H. D. Braymer ◽  
M. D. Socolofsky ◽  
S. A. Milligan
Keyword(s):  
Cell Wall ◽  
Neurospora Crassa ◽  
Wild Type ◽  
Morphological Comparison ◽  
Small Areas ◽  
Solid Media ◽  
Thin Sectioning ◽  
X Cells ◽  
Mutant Cells ◽  
Isolated Cell

The recently isolated cell wall mutant slime X of Neurospora crassa was prepared for ultrastructural and morphological comparison with the cell wall mutant slime. The purpose of this article is to discuss the methods of preparation for TEM and SEM observations, as well as to make a preliminary comparison of the two mutants.TEM: Cells of the slime mutant were prepared for thin sectioning by the method of Bigger, et al. Slime X cells were prepared in the same manner with the following two exceptions: the cells were embedded in 3% agar prior to fixation and the buffered solutions contained 5% sucrose throughout the procedure.SEM: Two methods were used to prepare mutant and wild type Neurospora for the SEM. First, single colonies of mutant cells and small areas of wild type hyphae were cut from solid media and fixed with OSO4 vapors similar to the procedure used by Harris, et al. with one alteration. The cell-containing agar blocks were dehydrated by immersion in 2,2-dimethoxypropane (DMP).

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