scholarly journals Nanoparticle Imaging with Polarization Interferometric Nonlinear Confocal Microscope

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Kohei Fujita ◽  
Chikara Egami

Polarization interferometric nonlinear confocal microscope has been developed for single nanoparticle analysis of drug delivery system (DDS). The microscope is a system based on a low cost and low power continuous wave (CW) laser light source. Also, the microscope observed shape anisotropy of the 200 nm diameter nanoparticle. According to nanoparticle imaging and CTF (contrast transfer function) curve observation of the microscope, three-dimensional resolution of the microscope measured up to 10 nm.

2018 ◽  
Vol 26 (17) ◽  
pp. 22218 ◽  
Author(s):  
Andreas Vetter ◽  
Raoul Kirner ◽  
Dmitrijs Opalevs ◽  
Matthias Scholz ◽  
Patrick Leisching ◽  
...  

2021 ◽  
Vol 111 (07-08) ◽  
pp. 507-512
Author(s):  
Eckart Uhlmann ◽  
Alexander Mühlenweg

Die aktuelle Literatur zum Thema Laser Powder Bed Fusion (L-PBF) beschäftigt sich größtenteils mit Dauerstrich- (continuous-wave, cw) Laser-Anlagen, die kontinuierlich strahlend das Pulverbett scannen. Zusätzlich gibt es Anlagen mit gepulsten (quasi-continuous-wave, qcw) Lasern, die einen Puls bestimmter Dauer auf einen Punkt abgeben und dann zum nächsten Punkt springen. Die Parametersätze sind nicht ohne Weiteres zwischen den Anlagentypen übertragbar. Diese Arbeit behandelt die Parameterentwicklung für den Werkstoff Haynes 282 auf einer qcw-L-PBF-Anlage.   Current literature on Laser Powder Bed Fusion (L-PBF) mainly focuses on continuous-wave (cw) laser systems to scan the powder bed while continuously emitting laser light. Also, there are systems with pulsed (quasi-continuous-wave, qcw) lasers to scan one point in the powder bed for a set duration and then jump to the next point. The parameter sets for one system are not easy to transfer to a different type of laser system. This work describes the development of a parameter set for Haynes 282 on a system with a qcw laser.


2006 ◽  
Vol 77 (6) ◽  
pp. 063112 ◽  
Author(s):  
Yoshinori Iketaki ◽  
Takeshi Watanabe ◽  
Nándor Bokor ◽  
Masaaki Fujii

Author(s):  
Joachim Frank

Cryo-electron microscopy combined with single-particle reconstruction techniques has allowed us to form a three-dimensional image of the Escherichia coli ribosome.In the interior, we observe strong density variations which may be attributed to the difference in scattering density between ribosomal RNA (rRNA) and protein. This identification can only be tentative, and lacks quantitation at this stage, because of the nature of image formation by bright field phase contrast. Apart from limiting the resolution, the contrast transfer function acts as a high-pass filter which produces edge enhancement effects that can explain at least part of the observed variations. As a step toward a more quantitative analysis, it is necessary to correct the transfer function in the low-spatial-frequency range. Unfortunately, it is in that range where Fourier components unrelated to elastic bright-field imaging are found, and a Wiener-filter type restoration would lead to incorrect results. Depending upon the thickness of the ice layer, a varying contribution to the Fourier components in the low-spatial-frequency range originates from an “inelastic dark field” image. The only prospect to obtain quantitatively interpretable images (i.e., which would allow discrimination between rRNA and protein by application of a density threshold set to the average RNA scattering density may therefore lie in the use of energy-filtering microscopes.


Author(s):  
Kenneth H. Downing

Three-dimensional structures of a number of samples have been determined by electron crystallography. The procedures used in this work include recording images of fairly large areas of a specimen at high tilt angles. There is then a large defocus ramp across the image, and parts of the image are far out of focus. In the regions where the defocus is large, the contrast transfer function (CTF) varies rapidly across the image, especially at high resolution. Not only is the CTF then difficult to determine with sufficient accuracy to correct properly, but the image contrast is reduced by envelope functions which tend toward a low value at high defocus.We have combined computer control of the electron microscope with spot-scan imaging in order to eliminate most of the defocus ramp and its effects in the images of tilted specimens. In recording the spot-scan image, the beam is scanned along rows that are parallel to the tilt axis, so that along each row of spots the focus is constant. Between scan rows, the objective lens current is changed to correct for the difference in specimen height from one scan to the next.


2020 ◽  
Vol 64 (5) ◽  
pp. 50405-1-50405-5
Author(s):  
Young-Woo Park ◽  
Myounggyu Noh

Abstract Recently, the three-dimensional (3D) printing technique has attracted much attention for creating objects of arbitrary shape and manufacturing. For the first time, in this work, we present the fabrication of an inkjet printed low-cost 3D temperature sensor on a 3D-shaped thermoplastic substrate suitable for packaging, flexible electronics, and other printed applications. The design, fabrication, and testing of a 3D printed temperature sensor are presented. The sensor pattern is designed using a computer-aided design program and fabricated by drop-on-demand inkjet printing using a magnetostrictive inkjet printhead at room temperature. The sensor pattern is printed using commercially available conductive silver nanoparticle ink. A moving speed of 90 mm/min is chosen to print the sensor pattern. The inkjet printed temperature sensor is demonstrated, and it is characterized by good electrical properties, exhibiting good sensitivity and linearity. The results indicate that 3D inkjet printing technology may have great potential for applications in sensor fabrication.


Author(s):  
L.S. Koh ◽  
H. Marks ◽  
L.K. Ross ◽  
C.M. Chua ◽  
J.C.H. Phang

Abstract A Laser Timing Probe (LTP) system which uses a noninvasive 1.3 µm continuous wave (CW) laser with frequency mapping and single point measurement capabilities is described. The frequency mapping modes facilitate the localization of signal maxima for subsequent single point measurements. Measurements of waveforms with long delays and 50 ps response time from NMOS and PMOS transistors are also shown.


2017 ◽  
Vol 68 (3) ◽  
pp. 453-458 ◽  
Author(s):  
Daniel Besnea ◽  
Alina Spanu ◽  
Iuliana Marlena Prodea ◽  
Gheorghita Tomescu ◽  
Iolanda Constanta Panait

The paper points out the advantages of rapid prototyping for improving the performances/constructive optimization of mixing devices used in process industries, here exemplified to propeller types ones. The multidisciplinary optimization of the propeller profile affords its design using parametric CAD methods. Starting from the mathematical curve equations proposed for the blade profile, it was determined its three-dimensional virtual model. The challenge has been focused on the variation of propeller pitch and external diameter. Three dimensional ranges were manufactured using the additive manufacturing process with Marker Boot 3D printer. The mixing performances were tested on the mixing equipment measuring the minimum rotational speed and the correspondent shaft torque for complete suspension achieved for each of the three models. The virtual and rapid prototyping method is newly proposed by the authors to obtain the basic data for scale up of the mixing systems, in the case of flexible production (of low quantities), in which both the nature and concentration of the constituents in the final product varies often. It is an efficient and low cost method for the rapid identification of the optimal mixing device configuration, which contributes to the costs reduction and to the growing of the output.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1448
Author(s):  
Nobukazu Kameyama ◽  
Hiroki Yoshida ◽  
Hitoshi Fukagawa ◽  
Kotaro Yamada ◽  
Mitsutaka Fukuda

Carbon dioxide (CO2) laser is widely used in commercial and industrial fields to process various materials including polymers, most of which have high absorptivity in infrared spectrum. Thin-film processing by the continuous wave (CW) laser is difficult since polymers are deformed and damaged by the residual heat. We developed the new method to make polypropylene (PP) and polystyrene (PS) sheets thin. The sheets are pressed to a Cu base by extracting air between the sheets and the base during laser processing. It realizes to cut the sheets to around 50 µm thick with less heat effects on the backside which are inevitable for thermal processing using the CW laser. It is considered that the boundary between the sheets and the base is in thermal equilibrium and the base prevents the sheets from deforming to support the backside. The method is applicable to practical use since it does not need any complex controls and is easy to install to an existing equipment with a minor change of the stage.


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