Digital processing of shadowgraph images taking into account the diffraction of light at a shock front

The aim of the study is to determine the shock wave position in experimental shadowgraph images and to evaluate the accuracy by digital image processing. The experimental images were obtained with the shock tube with a rectangular channel. The shadowgraph optical system formed a parallel light beam. It passed through the plane-parallel quartz glasses of the shock tube test section. The process synchronization system at the facility allows registering the shadowgraph images of unsteady flows with shock waves with a high-speed camera or with a single frame camera. The obtained spatial intensity profiles were used to determine the coordinates of gas-dynamic discontinuities at different stages of the flow evolution. shadowgraph patterns were analysed taking into account diffraction at the shock front in case of a laser light source.

Real-time irradiation system using patterned light to actuate light-driven on-chip gel actuators

A light-driven gel actuator is a potential candidate for a single-cell manipulation tool because it allows cells to be manipulated while ensuring less damage. Moreover, a large number of actuators can be integrated into a microfluidic chip because no wiring is required. Previously, we proposed a method for cell manipulation using light-driven gel actuators. However, the system used in the previous work did not allow the targeted cells to be manipulated in real time because the system used in the previous work could only irradiate preprogrammed patterned light. Moreover, when a large number of gel actuators are integrated into a chip, the Gaussian distribution of the laser light source results in the response characteristics of the gel actuators varying with the location of the actuator. In this work, we constructed a system that homogenized the intensity of the patterned light used for irradiation, allowing multiple gel actuators to be driven in parallel in real time. The intensity-homogenized patterned light improved the variations in the response characteristics of the gel actuators, and as a result, we succeeded in actuating gel actuators with various light patterns in real time.

Application of Taguchi Methodology in Evaluating the Rockwell Hardness of SLA 3D Printed Polymers

Stereolithography (SLA) is an Additive Manufacturing technology which converts liquid resins to solid parts layer-by-layer by selectively curing the liquid resin using a (laser) light source. The mechanical properties SLA 3D printed parts are not yet determined or estimated before printing. Thus, this study aims to identify the optimum 3D printing configuration based on the indentation hardness properties of SLA-printed polymer parts. Taguchi approach was used in identifying the optimum 3D printing configuration wherein different factors were considered to meet the requirements of the orthogonal arrays. Five pieces of 3D printed test blocks with 9 indentation points on the surface were prepared for each factor. The tests followed ASTM D785 – 03 using Rockwell Scale B. The result for the optimum 3D printing configuration of SLA 3D printed material were concluded as the values with the highest Rockwell Hardness Number.

Realization of Polarization and Malus’s Law Using The Smartphones

This work provides an approach for simplifying and teaching of the confusing topic of Polarisation of light and relating Malus’s Law. Teaching Polarisation and the Malus’s Law are modestly achieved by means of smartphones with a convenient light meter application. The apparatus is designed so that the polarizer, the analyser, the laser light source and the smartphone are precisely aligned on a rail. During the performance, the angle of the analyser is basically varied with respect to the polariser and the transmitted light intensity is measured by the light meter application. The results clearly show that the transmitted light intensity is directly proportional to the squared polarization angle. The approach surely provides accessibility for physics teachers and would help students to learn and internalize Polarisation and relating Malus’s Law in a better manner.

MEASURING THE OPTICAL CHARACTERISTICS AT THE BAIKAL NEUTRINO TELESCOPE SITE

The deep underwater Neutrino Telescope Baikal NT1000 has been deployed in Lake Baikal since 2015. Detector is mainly designed to study astrophysical neutrino fluxes at energies from a few TeV up to 100 PeV. The first stage NT1000 will be an array of 2300 optical modules with an instrumental volume of about 0.4 cubic kilometers, which is planned to be completed by 2020–2021. The properties of Baikal water and a combination of other related circumstances make it possible to create a unique installation in the world practice in sensitivity and angular resolution, opening up new horizons in astronomy and astrophysics. In this article basic information about the NT1000 and the being developed method to measure the optical characteristics at the detector’s water medium using a high-power laser light source are provided.