0000000000680575
AUTHOR
Paulis Paulins
showing 8 related works from this author
PLZT laser beam modulator
1992
Abstract Laser beam modulator on transparent electrooptic PLZT ceramics are developed for the use in teaching process in schools and universities. Characteristics of the modulator and its electronic control unit are given.
Warming of water in a glass
2016
The article focuses on the process of water warming from 0 °C in a glass. An experiment is performed that analyses the temperature in the top and bottom layers of water during warming. The experimental equipment is very simple and can be easily set up using devices available in schools. The temperature curves obtained from the experiment help us to understand the process of convection in the glass and to determine the temperature at which the density of water is maximum. In addition, computational fluid dynamics—CFD modeling is carried out to facilitate better comprehension of the phenomenon observed in the experiment.
Electro-optic control of photographic imaging quality through ‘Smart Glass’ windows in optics demonstrations
2017
An experimental setup allowing the modeling of conditions in optical devices and in the eye at various degrees of scattering such as cataract pathology in human eyes is presented. The scattering in cells of polymer-dispersed liquid crystals (PDLCs) and 'Smart Glass' windows is used in the modeling experiments. Both applications are used as optical obstacles placed in different positions of the optical information flow pathway either directly on the stimuli demonstration computer screen or mounted directly after the image-formation lens of a digital camera. The degree of scattering is changed continuously by applying an AC voltage of up to 30–80 V to the PDLC cell. The setup uses a camera wi…
Multicolour LEDs in educational demonstrations of physics and optometry
2014
LED light sources are used to design experimental setup for university courses teaching human color vision. The setup allows to demonstrate various vision characteristics and to apply for student practical exercises to study eye spectral sensitivity in different spectral range using heterochromatic flicker photometry. Technique can be used in laboratory works for students to acquire knowledge in visual perception, basics of electronics and measuring, or it can be applied as fully computer control experiment. Besides studies of the eye spectral sensitivity students can practice in trichromatic color matching and other visual perception tasks
Tunable liquid lens equipped virtual reality adapter for scientific, medical, and therapeutic goals
2018
We adapted virtual reality appliances to use them in scientific medical diagnostics and therapeutic aims by incorporated as part of appliance ocular system two electrically tunable Optotune liquid lenses, controllable by computer USB ports within 20D range. In present time we used the appliance to investigate the mono- and/or binocularly illusory perception dominances (Shapiro and al;2008), nonlinearities caused by controversial Gestalt recognition of motion. Back layer of stimuli elements contained internal motion sources - clockwise spinning disk on neutral background. Disk consisted of centrosymmetric radial rays which luminance was sinus mode modulated along the disc circumference. Spin…
“SmartGlass” Obstacles for Dynamic Inducing of Light Scattering in Vision Research Experiments
2017
We describe a technique that allows control of visual stimuli quality through the use of a setup with a polymer dispersed liquid crystal (PDLC) film positioned in the optical pathway of one or both human eyes. Nowadays, PDLC films allow alteration of the resolution and contrast limits of the transmitted light due to continuous change in the light scattering that is obtained by the application of an AC electrical field. In our experimental setup, the use of a wide-aperture up to area of 20 x 15 cm2 PDLC sheet is combined with a flat-screen PC display or with a modified display emission block without its interference filter unit and with an installed individually controllable colored light-em…
LED Based Dual Wavelength Heterochromatic Flicker Method for Separate Evaluation of Lutein and Zeaxanthin in Retina
2013
The decrease of density and consequentially optical density of macular pigment serves as a diagnostic mean for a number of ophthalmological pathologies, particularly as a risk factor for age related macular degeneration. Macular pigment absorbs light in short wavelength blue spectral range. Thus the optical density of macular pigment can be detected by various optical – both objective and subjective psychophysical techniques. Latter techniques use eye and brain visual pathways as spectral sensitive optical detector and decision maker, and exploit perception facility to process information flow in a unique manner to create various perception illusions. The psychophysical methods of detection…
Paaugstinātas grūtības eksperimentālie un demonstrējumu pētnieciskie uzdevumi vidusskolēniem
2013
Elektroniskā versija nesatur pielikumus