Search results for "Microscope"
showing 10 items of 1412 documents
Advances in three-dimensional integral imaging: sensing, display, and applications [Invited]
2013
Three-dimensional (3D) sensing and imaging technologies have been extensively researched for many applications in the fields of entertainment, medicine, robotics, manufacturing, industrial inspection, security, surveillance, and defense due to their diverse and significant benefits. Integral imaging is a passive multiperspective imaging technique, which records multiple two-dimensional images of a scene from different perspectives. Unlike holography, it can capture a scene such as outdoor events with incoherent or ambient light. Integral imaging can display a true 3D color image with full parallax and continuous viewing angles by incoherent light; thus it does not suffer from speckle degrad…
Evaluation of the penetration of CHX 2% on dentinal tubules using Conventional Irrigation, Sonic Irrigation (EDDY) and Passive Ultrasonic Irrigation …
2021
Background Various procedures and techniques have been developed to increase the effectiveness and penetration of irrigants into the dentinal tubules and anatomical anfractuosities. Objective: The purpose of this in vitro study was to compare the effect of different irrigation techniques such as conventional irrigation with a syringe, sonic activation irrigation with EDDY and Passive Ultrasonic Irrigation. All these on dentinal tubule penetration using Chlorhexidine. Material and methods 45 lower premolar teeth extracted for orthodontic reasons were used. These teeth were decoronated to a length of 18mm. This working length was achieved by inserting a size 15 K file into the root canal unti…
Measuring electrostatic double-layer forces on HOPG at high surface potentials
1999
Abstract The aim of this study was to investigate surface forces in aqueous electrolyte solutions between surfaces with high electric potentials. Therefore the force between a surface of highly oriented pyrolytic graphite (HOPG) and a silicon nitride tip of an atomic force microscope was measured. Various electric potentials by a counter electrode were applied to the HOPG, which served as working electrode. As predicted by the Poisson–Boltzmann theory the electrostatic double-layer force changed only in a narrow potential range of ≈300 mV. At high negative sample potentials, where the negatively charged tip was repelled from the sample, the force saturated. At positive potentials an attract…
Force interactions and adhesion of gold contacts using a combined atomic force microscope and transmission electron microscope
2002
Force interactions and adhesion of gold contacts using a combined atomic force microscope and transmission electron microscope
Self-assembly of Organic Molecules on Insulating Surfaces
2015
Molecular self-assembly is known to provide a powerful tool for creating functional structures, with the ultimate structure and functionality encoded in the molecular building blocks. Upon molecule deposition onto surfaces, functional structures have been created ranging from defect-free, highly symmetric two-dimensional layers to complex assemblies with dedicated functionality. Especially organic molecules play a key role for molecular self-assembly due to their impressive structural flexibility and the high degree of control by chemical synthesis. Furthermore, the surface itself provides another exciting dimension: adjusting the subtle balance between intermolecular and molecule-surface i…
Correlative atomic force and confocal fluorescence microscopy: single molecule imaging and force induced spectral shifts (Conference Presentation)
2016
A grand challenge in nanoscience is to correlate structure or morphology of individual nano-sized objects with their photo-physical properties. An early example have been measurements of the emission spectra and polarization of single semiconductor quantum dots as well as their crystallographic structure by a combination of confocal fluorescence microscopy and transmission electron microscopy.[1] Recently, the simultaneous use of confocal fluorescence and atomic force microscopy (AFM) has allowed for correlating the morphology/conformation of individual nanoparticle oligomers or molecules with their photo-physics.[2, 3] In particular, we have employed the tip of an AFM cantilever to apply c…
Sensor response time evaluations of trace hydrogen gaseous species with platinum using Kelvin Probe
2012
Kelvin Probe (KP), a non-contact, non-destructive vibrating capacitor device, was used to measure the work function (WF) difference of thin Pt films, deposited on oxidized silicon substrates, with highly diluted H 2 gas, in ppm levels, in the presence of with and without relative humidity (RH). Response times were extracted from the behavior of WF shift as a function of H 2 concentration values. Measurements were compared for zero and non-zero RH conditions at a fixed temperature of 30°C. Changes in WF were evaluated by using HP VEE program, suitably modified for the present measurements. The events were executed step by step for every second time interval through an input formatted file. T…
Micro-Raman characterization of graphene grown on SiC(000-1)
2014
Graphene (Gr) was grown on the C face of 4H-SiC under optimized conditions (high annealing temperatures ranging from 1850 to 1950°C in Ar ambient at 900 mbar) in order to achieve few layers of Gr coverage. Several microscopy techniques, including optical microscopy (OM), ?Raman spectroscopy, atomic force microscopy (AFM) and atomic resolution scanning transmission electron microscopy (STEM) have been used to extensively characterize the lateral uniformity of the as-grown layers at different temperatures. ?Raman analysis provided information on the variation of the number of layers, of the stacking-type, doping and strain.
Unraveling the LiNbO3 X-cut surface by atomic force microscopy and density functional theory
2014
The ${\text{LiNbO}}_{3}$(2$\overline{1}\overline{1}0$) surface, commonly referred to as X-cut, is investigated by means of atomic force microscopy and first-principles calculations. Atomically resolved atomic force microscopy images show geometrical patterns not compatible with truncated bulk terminations. Fast Fourier transformation of the real-space images shows an oblique surface unit cell with lattice parameters of $a=0.75\ifmmode\pm\else\textpm\fi{}0.02$ nm, $b=0.54\ifmmode\pm\else\textpm\fi{}0.02$ nm, and $\ensuremath{\alpha}=94.{8}^{\ensuremath{\circ}}$. Comparing these experimental results with the theoretical models of stable surface terminations provides clear evidence for the for…
An Investigation of the Energy Levels within a Common Perovskite Solar Cell Device and a Comparison of DC/AC Surface Photovoltage Spectroscopy Kelvin…
2017
We present a study of the energy levels in a FTO/TiO2/CH3NH3PbI3/Spiro solar cell device. The measurements are performed using a novel ambient pressure photoemission (APS) technique alongside Contact Potential Difference data from a Kelvin Probe. The Perovskite Solar Cell energy band diagram is demonstrated for the device in dark conditions and under illumination from a 150W Quartz Tungsten Halogen lamp. This approach provides useful information on the interaction between the different materials in this solar cell device. Additionally, non-destructive macroscopic DC and AC Surface Photovoltage Spectroscopy (SPS) studies are demonstrated of different MAPBI3 device structures to give an indic…