scholarly journals Method and portable bench for tests of the laser optical calibration system components for the Baikal-GVD underwater neutrino Cherenkov telescope

2021 ◽  
Vol 16 (12) ◽  
pp. C12011
Author(s):  
V.A. Allakhverdyan ◽  
A.D. Avrorin ◽  
A.V. Avrorin ◽  
V.M. Aynutdinov ◽  
R. Bannasch ◽  
...  
Keyword(s):  
Large Scale ◽  
Test Bench ◽  
Light Emission ◽  
Testing Procedure ◽  
Optical Parameters ◽  
Calibration System ◽  
Optical Elements ◽  
Neutrino Telescopes ◽  
3D Scan ◽  
Laser Calibration

Abstract The Large-scale deep underwater Cherenkov neutrino telescopes like Baikal-GVD, ANTARES or KM3NeT, require calibration and testing methods of their optical modules. These methods usually include laser-based systems which allow us to check the telescope responses to the light and for real-time monitoring of the optical parameters of water such as absorption and scattering lengths, which show seasonal changes in natural reservoirs of water. We will present a testing method of a laser calibration system and a set of dedicated tools developed for Baikal-GVD, which includes a specially designed and built, compact, portable, and reconfigurable scanning station. This station is adapted to perform fast quality tests of the underwater laser sets just before their deployment in the telescope structure, even on ice, without a darkroom. The testing procedure includes the energy stability test of the laser device, 3D scan of the light emission from the diffuser and attenuation test of the optical elements of the laser calibration system. The test bench consists primarily of an automatic mechanical scanner with a movable Si detector, beam splitter with a reference Si detector and, optionally, Q-switched diode-pumped solid-state laser used for laboratory scans of the diffusers. The presented test bench enables a 3D scan of the light emission from diffusers, which are designed to obtain the isotropic distribution of photons around the point of emission. The results of the measurement can be easily shown on a 3D plot immediately after the test and may be also implemented to a dedicated program simulating photons propagation in water, which allows us to check the quality of the diffuser in the scale of the Baikal-GVD telescope geometry.

scholarly journals Comparison of Some Physical Parameters of Whole and Scored Lisinopril and Lisinopril/Hydrochlorthiazide Tablets

2008 ◽  
Vol 8 (4) ◽  
pp. 391-395 ◽  
Author(s):  
Edina Vranić ◽  
Alija Uzunović
Keyword(s):  
Large Scale ◽  
Testing Procedure ◽  
Physical Parameters ◽  
Hardness Testing ◽  
Disintegration Time ◽  
Adequate Dose ◽  
Response Information ◽  
Tablet Splitting ◽  
Good Patient Compliance ◽  
Accepted Practice

Tablets are one of the most popular and preferred solid dosage forms because they can be accurately dosed, easily manufactured and packaged on a large scale, have good physical and chemical stability, and can contribute to good patient compliance given their ease of administration. The ability to match doses to patients depends on the availability of multiple dose sizes and adequate dose-response information. These are not always provided, so splitting of the tablets is sometimes necessary, Tablet splitting is an accepted practice in dispensing medication, It has been used when a dosage form of the required strength is not available commercially. The aim of our study was to compare some physical parameters of whole and scored lisinopril and lisinopril/hydrochlorthiazide tablets and to accept or exclude their influence on the obtaining of required dosage.According to the results obtained, we may conclude that tablets from batch “I” “IL “III” and “IV” satisfied pharmacopeial requirements concerning crushing strength, friability, disintegration time and mass uniformity. The hardness testing showed acceptable reproducibility and indicate that the data variation was primarily from the irreversible changes in the structure of tablet samples. The act of compacting powders stores energy within the tablets, by shifting or compressing the intermolecular bonds within the particles. The tablets have a natural tendency to relax once pressure is removed, and this tendency works against the interparticle bonding formed during compression. Hardness testing procedure causes irreversible changes in this structure.

Simulation of Large Scale KDP Crystal Polishing by Computer Controlled Micro-Nano Deliquescence

2012 ◽  
Vol 497 ◽  
pp. 165-169 ◽  
Author(s):  
He Ping Zhang ◽  
Dong Ming Guo ◽  
Xu Wang ◽  
Hang Gao
Keyword(s):  
Large Scale ◽  
Surface Condition ◽  
Single Point ◽  
Damage Threshold ◽  
Diamond Turning ◽  
Water Soluble ◽  
Optical Elements ◽  
Kdp Crystal ◽  
Computer Controlled ◽  
Laser Induced Damage

Although Single Point Diamond Turning (SPDT) can do pretty well in optical surfacing of large scale KDP crystal, both the surface accuracy and integrity are considerably high; meanwhile as the defects of micro-waveness and stress are inevitable, the laser-induced damage threshold of KDP optical elements after SPDT still cannot be satisfied. Because of the characters of deliquescent and water-soluble, the process of computer controlled Micro-nano deliquescence is attempted to remove the residual micro-waveness on KDP surface after SPDT. Based on the assumption of Preston and the characters of Micro-nano deliquescence, the model of material removal ratio is suggested, the dwell time for ascertained KDP surface is solved, the processing of computer controlled Micro-nano deliquescence is simulated and the processed surface condition on theory is obtained. Besides, the influences of different parameters on the surfacing efficiency and accuracy are analyzed. Finally, three polishing tracks are comparatively analyzed. The simulation results are quite important in guiding the experimental polishing of large scale KDP by computer controlled Micro-nano deliquescence

Modeling and Identification of Elastomeric Bearing Characteristics for Large-Scale Simulations

1998 ◽  
Vol 120 (1) ◽  
pp. 63-73 ◽  
Author(s):  
K. N. Morman ◽  
E. Nikolaidis ◽  
J. Rakowska ◽  
S. Seth
Keyword(s):  
Large Scale ◽  
Dynamic Stiffness ◽  
Testing Procedure ◽  
Nonlinear Dependence ◽  
Model Parameters ◽  
Elastomeric Bearing ◽  
Nonlinear Viscoelastic ◽  
Component Test ◽  
Differential Type ◽  
Stiffness And Damping

A constitutive equation of the differential type is introduced to model the nonlinear viscoelastic response behavior of elastomeric bearings in large-scale system simulations for vibration assessment and component loads prediction. The model accounts for the nonlinear dependence of dynamic stiffness and damping on vibration amplitude commonly observed in the behavior of bearings made of particle-reinforced elastomers. A testing procedure for the identification of the model parameters from bearing component test data is described. The experimental and analytical results for predicting the behavior of four (4) different car bushings are presented. In an example application, the model is incorporated in an ADAMS simulation to study the dynamic behavior of a car rear suspension.

High-precision Shack-Hartmann wavefront sensing with a multi-focal diffraction Taiji-lenslet array

Laser Physics ◽  
2021 ◽  
Vol 31 (12) ◽  
pp. 125401
Author(s):  
Yaling Yang ◽  
Yanli Zhang ◽  
Junyong Zhang ◽  
You Li ◽  
Dean Liu
Keyword(s):  
Large Scale ◽  
Measurement Accuracy ◽  
Laser Beams ◽  
Diffractive Lens ◽  
Wavefront Sensors ◽  
Entrance Pupil ◽  
Optical Elements ◽  
Lenslet Array ◽  
Location Algorithm ◽  
Detection Instrument

Abstract A Hartmann wavefront sensor is a type of wavefront detection instrument that has been widely used in various fields. Traditional Hartmann wavefront sensors usually comprise a monofocal refraction lenslet array to segment the wavefront at the entrance pupil. Each wavelet is focused at the focal plane along the projection of the lenslet, forming the foci array. Unlike the multifocal self-interference Taiji-lenslet array, a type of multifocal diffraction Taiji-lenslet array was proposed in this study to improve the measurement accuracy using the weighted centroid location algorithm of these multifocal spots, where the latter is more easily designed than the former. An optical experiment was implemented using the multifocal diffraction Taiji-lenslet array to verify its effectiveness. As a type of diffractive lens, a large-aperture Taiji-lenslet array can be easily fabricated via lithography, which has great potential for application in the measurement of large-scale laser beams and optical elements.

scholarly journals Phase-Shift Optimization in AA/PVA Photopolymers by High-Frequency Pulsed Laser

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1887
Author(s):  
Daniel Puerto ◽  
Sergi Gallego ◽  
Jorge Francés ◽  
Andrés Márquez ◽  
Inmaculada Pascual ◽  
...  
Keyword(s):  
Phase Shift ◽  
High Frequency ◽  
Large Scale ◽  
Pulsed Laser ◽  
Laser Exposure ◽  
Continuous Laser ◽  
Frequency Limit ◽  
Optical Elements ◽  
First Time ◽  
532 Nm

Photopolymers can be used to fabricate different holographic optical elements, although maximization of the phase-shift in photopolymers has been a challenge for the last few decades. Different material compositions and irradiation conditions have been studied in order to achieve it. One of the main conclusions has been that with continuous laser exposure better results are achieved. However, our results show for the first time that higher phase-shift can be achieved using a pulsed laser. The study has been conducted with crosslinked acrylamide-based photopolymers exposed with a pulsed laser (532 nm). The increment of the phase-shift between the pulsed laser and continuous laser exposure is 17%, achieving a maximum phase-shift of 3π radians and a refractive index shift of 0.0084 at the zero spatial frequency limit, where monomer diffusion does not take place. This allows this photopolymer to be used in large-scale manufacturing.

Cost-effective large-scale fabrication of diffractive optical elements by using conventional semiconducting processes

2012 ◽  
Vol 51 (33) ◽  
pp. 8052 ◽  
Author(s):  
Seunghwan Yoo ◽  
Ho Young Song ◽  
Junghoon Lee ◽  
Cheol-Yong Jang ◽  
Hakgeun Jeong
Keyword(s):  
Large Scale ◽  
Cost Effective ◽  
Diffractive Optical Elements ◽  
Optical Elements

scholarly journals Unified atmospheric neutrino passing fractions for large-scale neutrino telescopes

2018 ◽  
Vol 2018 (07) ◽  
pp. 047-047 ◽  
Author(s):  
Carlos A. Argüelles ◽  
Sergio Palomares-Ruiz ◽  
Austin Schneider ◽  
Logan Wille ◽  
Tianlu Yuan
Keyword(s):  
Large Scale ◽  
Atmospheric Neutrino ◽  
Neutrino Telescopes

scholarly journals Identification of Micro-Scale Landforms of Landslides Using Precise Digital Elevation Models

Geosciences ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 117 ◽  
Author(s):  
František Chudý ◽  
Martina Slámová ◽  
Julián Tomaštík ◽  
Roberta Prokešová ◽  
Martin Mokroš
Keyword(s):  
Large Scale ◽  
Forest Canopy ◽  
Digital Elevation Models ◽  
Canopy Cover ◽  
Point Clouds ◽  
Tree Canopy ◽  
Automatic Identification ◽  
Optical Parameters ◽  
Micro Scale ◽  
Digital Elevation

An active gully-related landslide system is located in a deep valley under forest canopy cover. Generally, point clouds from forested areas have a lack of data connectivity, and optical parameters of scanning cameras lead to different densities of point clouds. Data noise or systematic errors (missing data) make the automatic identification of landforms under tree canopy problematic or impossible. We processed, analyzed, and interpreted data from a large-scale landslide survey, which were acquired by the light detection and ranging (LiDAR) technology, remotely piloted aircraft system (RPAS), and close-range photogrammetry (CRP) using the ‘Structure-from-Motion’ (SfM) method. LAStools is a highly efficient Geographic Information System (GIS) tool for point clouds pre-processing and creating precise digital elevation models (DEMs). The main landslide body and its landforms indicating the landslide activity were detected and delineated in DEM-derivatives. Identification of micro-scale landforms in precise DEMs at large scales allow the monitoring and the assessment of these active parts of landslides that are invisible in digital terrain models at smaller scales (obtained from aerial LiDAR or from RPAS) due to insufficient data density or the presence of many data gaps.

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