scholarly journals THEORETICAL MODEL AND DESIGN OF A NOVEL STATIC POLARIZATION WIND IMAGING INTERFEROMETER (NSPWII)

2020 ◽  
Vol V-1-2020 ◽  
pp. 383-388
Author(s):  
C. Zhang ◽  
T. Yan ◽  
T. Mu ◽  
Y. He
Keyword(s):  
Theoretical Model ◽  
Wind Field ◽  
Michelson Interferometer ◽  
Atmospheric Temperature ◽  
Imaging Interferometer ◽  
New Type ◽  
Field Velocity ◽  
Static Polarization ◽  
Pass Through ◽  
Light Beams

Abstract. Polarization array based polarization Michelson wind field detection interferometer is a new type of interferometer for detecting atmospheric temperature and wind field velocity. We proposed a theoretical model and design of the novel static polarization wind imaging interferometer (NSPWII). It consists of a group of polarizers and waveplates, a polarization beamsplitter, a field widened Michelson interferometer, a pyramid prism, and a polarization array. Based on the principle of polarization interference, a polarization array composed of four polarizers with 45° polarization directions differences is directly in front of the detector, and four modulated light beams from the pyramid prism pass through the four polarizers. Then, interferograms with four different intensity are imaged on the detector simultaneously, which further provides the atmospheric temperature and wind field velocity. The advantages of this instrument are static (no moving parts), achromatic, and temperature compensated. It is capable of measuring the upper atmospheric wind field in real time with a high precision.

Prelude: A Sense of Place

2016 ◽  
Author(s):  
Connor J. Fitzmaurice ◽  
Brian J. Gareau
Keyword(s):  
Social Relations ◽  
Sense Of Place ◽  
Food System ◽  
Social Connection ◽  
Commodity Chains ◽  
Farming Practice ◽  
Organic Products ◽  
New Type ◽  
Pass Through

The conventionalization of the organic sector has led many to be skeptical about the possibility of organic in and of itself promoting a meaningfully sustainable alternative to the modern agricultural paradigm. However, the bifurcation of the organic market into both mainstream and alternative spheres provides places within the food system where investigating the work involved in creating new economic and social relations of farming practice makes sense. We may very well have come to an era in which most organic products pass through the same types of industrial commodity chains as organic initially set out to challenge. But more and more people desire a new type of economy, one that fosters social connection, meaning, and new relationships of exchange (...

A Study of the Simulation of a Light Trapping Module for Increasing the Absorption Efficiency of Solar Cells

2013 ◽  
Vol 437 ◽  
pp. 198-201
Author(s):  
Wang Lin Liu ◽  
Guan Yu Lin ◽  
Hsiharng Yang
Keyword(s):  
Solar Cell ◽  
Light Trapping ◽  
Incident Light ◽  
Absorption Efficiency ◽  
Optical Channel ◽  
Back Side ◽  
Transparent Substrate ◽  
Channel Opening ◽  
Pass Through ◽  
Light Beams

This study proposed a light trapping module to improve the light path in a solar cell in order to increase its light absorption efficiency. The microlens on a transparent substrate concentrates incident light into several light beams, which it leads into the optical channel on the back side. The optical channel is designed by coating highly reflective metals on the same transparent substrate, then an optical channel opening is made at the light beam focus so the light beams can pass through the optical channel and irradiate the solar cell. The light reflected by the solar cell is reflected again by the metal surface to the upper film of the solar cell, thus, increasing the absorption efficiency of the solar cell and reducing the film thickness of the solar cell to obtain better electrical properties. In this simulation the refractive index of the microlens was set as 1.43, the optical channel was 25 μm and the spacing was 0.27 mm, thus, the simulated absorption efficiency reached over 80%. The feasibility of this study was thus proved.

scholarly journals Controlled Double-Jet Mixing of Light Speeds in the Trigonometric Realm

2018 ◽  
Vol 10 (1) ◽  
pp. 53
Author(s):  
Jiri Stavek
Keyword(s):  
Special Relativity ◽  
Light Beam ◽  
Doppler Effect ◽  
Michelson Interferometer ◽  
Rotating Disk ◽  
Rotating Disks ◽  
Jet Mixing ◽  
Null Result ◽  
Michael Faraday ◽  
Light Beams

We were inspired by three great concepts: 1. Pythagorean means, 2. Pierre de Fermat´s principle of the least time, 3. Michael Faraday´s concept of vibrating rays in longitudinal and transverse directions. We have formulated an extended Doppler formula for rectilinear motions in the absolute spacetime where both postulates of the special relativity are valid. The second postulate of the special relativity for rectilinear motions was derived as the harmonic mean speed based on the Pythagoras-Fermat-Faraday (PF2) model. The null result of the Michelson-Morley experiment is valid for the arms of that interferometer separated by the angle π/2. However, for the angles smaller than π/2 a predicted fringe shift should be observed. For the circular motions the Doppler formula combines the longitudinal and transverse speeds in such a way that the frequency of the rotating light beam is diluted by a factor [1-(v/c)2]0.5 and the wavelength of that light beam is extended by the same factor. The Doppler formula for light beams can be tested for the rotating source and the detector placed close to the rim of that rotating disk in a defined position. In order to obtain new experimental data we propose to construct the Michelson-Morley-Harress-Sagnac interferometer where rotating disks have being attached to both arms of the Michelson interferometer. In rotating disks we might prepare light beams with defined independent values of their longitudinal speeds and after the mixing of these two light beams on their return path to the detector we might observe predicted fringe shifts. In these circular paths the second postulate of the special relativity is not valid. The full composition of Doppler formula is given by the interplay of the macro Doppler effect (the relative motion of the source and observer) and the micro Doppler effect (the combination of the longitudinal and transverse vibration speeds of that oscillating particle – the elasticity of the photon wave).

An Optical Fuzzy Control Servo System for Biomedical Specimen Inspections

2010 ◽  
Author(s):  
Fu-Shin Lee ◽  
Chang-Li Lin
Keyword(s):  
Fuzzy Control ◽  
Fuzzy Logic Controller ◽  
Optical Biopsy ◽  
Inspection System ◽  
Image Sharpness ◽  
Data Acquisition Board ◽  
Pass Through ◽  
Focus Plane ◽  
Fuzzy Control Algorithm ◽  
Light Beams

The object of this research is to build an optical servo inspection system by integrating optical acquisition mechanisms and controlling algorithm to perform auto biomedical specimen inspections. The system applies a fuzzy control algorithm to exercise optical zooming, focusing, and sectioning functions on the inspected specimens. The paper also utilizes the MATLAB/SIMULINK platform to implement the fuzzy logic controller, and a NI multi-function data acquisition board to deliver control signals, which minutely displace the optical lenses system to execute prescribed functions. The optical system consists of an image focusing subsystem, which receives processed sharpness values of captured images, a con-focal pinhole aperture subsystem, which holds a pinhole to allow only light beams from in-focus plane specimen images to pass through, and a piezoactuator, which serves to minutely displace a plate with the pinhole to perform the optical biopsy function. As to accomplish the optical biopsy goal, the biomedical sample images on slightly differentiated focus depth planes are therefore acquired separately according to calculated image sharpness values.

Theoretical Model and Mechanical Performance of Semi-Integral Abutment Jointless Bridge

2013 ◽  
Vol 361-363 ◽  
pp. 1166-1169
Author(s):  
Tian Li Wang ◽  
Qing Ning Li ◽  
Da Lin Hu
Keyword(s):  
Theoretical Model ◽  
Prestressed Concrete ◽  
Mechanical Performance ◽  
Bridge Engineering ◽  
Expansion Joint ◽  
Integral Abutment ◽  
Weak Part ◽  
New Type ◽  
Jointless Bridge

Expansion joint of a bridge is a weak part of structure, it leads to early structure destroy and reduces the bridge life. The paper put forward a new type of Jointless Bridge --- Semi–Integral Abutment Jointless Bridge, and its theoretical model was built. An engineering of four spans 100m length Prestressed Concrete Semi–Integral Abutment Jointless Bridge was analyzed, and results that its mechanical performance is so excellent that it should be wide applied in bridge engineering.

scholarly journals Precision validation of MIPAS-Envisat products

2007 ◽  
Vol 7 (1) ◽  
pp. 911-929 ◽  
Author(s):  
C. Piccolo ◽  
A. Dudhia
Keyword(s):  
Standard Deviation ◽  
Temporal Structure ◽  
Michelson Interferometer ◽  
Atmospheric Temperature ◽  
Retrieval Process ◽  
Full Resolution ◽  
Atmospheric Sounding ◽  
Horizontal Inhomogeneity ◽  
Temperature Retrieval ◽  
Level 2

Abstract. This paper discusses the variation and validation of the precision, or estimated random error, associated with the ESA Level 2 products from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). This quantity represents the propagation of the radiometric noise from the spectra through the retrieval process into the Level 2 profile values. The noise itself varies with time, steadily rising between decontamination events, but the Level 2 precision has a greater variation due to the atmospheric temperature which controls the total radiance received. Hence, for all species, the precision varies latitudinally/seasonally with temperature, with a small superimposed temporal structure determined by the degree of ice contamination on the detectors. The precision validation involves comparing two MIPAS retrievals at the intersections of ascending/descending orbits. For 5 days per month of full resolution MIPAS operation, the standard deviation of the matching profile pairs is computed and compared with the precision given in the MIPAS Level 2 data. Even taking into account the propagation of the pressure-temperature retrieval errors into the VMR retrieval, the standard deviation of the matching pairs is usually a factor 1–2 larger than the precision. This is thought to be due to effects such as horizontal inhomogeneity of the atmosphere and instability of the retrieval.

scholarly journals Development and Investigation of Fully Ventilated Deep Subwavelength Absorbers

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1835
Author(s):  
Heng Wang ◽  
Qibo Mao
Keyword(s):  
Theoretical Model ◽  
Sound Absorption ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Acoustic Metamaterial ◽  
Acoustic Performance ◽  
Half Wave ◽  
Quarter Wave ◽  
New Type ◽  
Good Agreement

A new type of deep subwavelength acoustic metamaterial (AMM) absorber with 100% ventilation is presented in this study. The proposed ventilation absorber consists of coiled-up half-wave resonators (HWRs) and quarter-wave resonators (QWRs). First, the sound absorption and sound transmission performances for absorbers were analyzed considering the thermal viscosity dissipation. Then, the prototype with ten HWRs and three QWRs composed of acrylic plates was manufactured based on the theoretical model. The acoustic performance of the absorber was tested in an air-filled acoustic impedance tube to determine the sound absorption and transmission loss performances. Good agreement was found between the measured and theoretically predicted results. The experimental results show that the proposed ventilation AMM absorber is able to achieve sound absorption in a range between 330 Hz and 460 Hz with a thickness of only 32 mm (about 3% of the wavelength in the air). Furthermore, the sound transmission loss can achieve 17 dB from 330 Hz to 460 Hz. The main advantage of the proposed absorber is that it can be completely ventilated in duct noise control.

scholarly journals Interaction of Bessel Light Beams with Epsilon-near-zero Metamaterials

2014 ◽  
Vol 3 (1) ◽  
pp. 44
Author(s):  
S. Kurilkina ◽  
M. Binhussain ◽  
V. Belyi ◽  
N. Kazak
Keyword(s):  
Magnetic Fields ◽  
Cone Angle ◽  
Dielectric Media ◽  
Electric And Magnetic Fields ◽  
New Type ◽  
Light Beams ◽  
Analytical Expressions ◽  
Plasmon Polaritons ◽  
Bessel Light Beams ◽  
Epsilon Near Zero

The article explores possibilities and conditions of generation of a new type of diffraction-free needle-like field Bessel plasmon polaritons (BPPs) with super narrow cone angle in an epsilon-near-zero metamaterial, surrounded by semi-infinite dielectric media. Correct analytical expressions are obtained and analyzed in detail for the electric and magnetic fields of BPPs formed inside and outside the metamateral slab.

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