scholarly journals A Setup for Measuring the Centering Error of a Dual-Element Pyroelectric Infrared Sensor Module

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6684
Author(s):  
Vu Toan Thang ◽  
Vu Van Quang ◽  
Ngoc-Tam Bui
Keyword(s):  
Mechanical Axis ◽  
Optical Axis ◽  
Focal Point ◽  
Fresnel Lens ◽  
Experimental Setup ◽  
Infrared Sensor ◽  
Output Response ◽  
Sensor Module ◽  
The Difference

This paper presents an experimental setup to measure the horizontal centering error of a pre-built pyroelectric infrared (PIR) sensor module, in which a dual-element PIR sensor is aligned at the focal point of a single-zone Fresnel Lens. In the setup, the sensor module was placed facing a modulated infrared radiating source and turned over a range of horizontal angles. The position of the optical axis of the sensor module was determined based on the analysis of the output response of the sensor at turned angles. Thus, the horizontal centering error of the module is defined as the difference between the mechanical axis of the housing and the found optical axis. For the prebuilt sensor module, with the specific available equipment, the measurement of the centering error of the module achieved a resolution of 0.02 degrees.

ON OPTIMUM PUPIL FIELDS WITH MAXIMUM ELECTRIC FIELD COMPONENT IN FOCUS

2010 ◽  
Vol 19 (01) ◽  
pp. 189-201
Author(s):  
H. P. URBACH ◽  
S. F. PEREIRA ◽  
D. J. BROER
Keyword(s):  
Electric Field ◽  
Field Component ◽  
Optical Axis ◽  
Focal Point ◽  
Longitudinal Component ◽  
Electric Field Component ◽  
Incident Power ◽  
Entrance Pupil ◽  
Maximum Electric Field ◽  
High Na Lens

The field in the entrance pupil of a high NA lens can be optimized such that, for given incident power, the electric field component in a given direction in the focal point is maximum. If the field component is chosen parallel to the optical axis, the longitudinal component is maximized and it is found that the optimum longitudinal component is narrower than the Airy spot. We discuss how this can be used to obtain higher resolution in photolithography when a resist is used that is sensitive to only the longitudinal component. We describe a proposition for realizing such resist.

Markedness and Perspective in the Interpretation of the Active and Passive Voice

1974 ◽  
Vol 26 (2) ◽  
pp. 189-195 ◽  
Author(s):  
Irene Klenbort ◽  
Moshe Anisfeld
Keyword(s):  
Information Content ◽  
Focal Point ◽  
The Other ◽  
Clear Pattern ◽  
Passive Voice ◽  
Other Hand ◽  
Logical Subject ◽  
The Difference

The subjects were presented with active and passive sentences. For each sentence, they had to choose between two alternative implications. The pattern of choices indicates that in the passive the logical subject was interpreted by the subjects as the focal point of the information asserted by the sentence and as the carrier of overall responsibility for the sentential proposition. In contrast to the passive, there was no clear pattern of preferences for the active. The difference between the two voices was attributed to their markedness asymmetry, the passive being marked and the active unmarked. It is concluded that the active offers a neutral structure for conveying information; a structure available for use when one does not want to superimpose on the information content any stylistic or connotational implications. The passive, on the other hand, suggests special connotations in addition to the basic message.

A Novel High Concentration Fresnel Lens as a Solar Concentrator

2021 ◽  
pp. 1-29
Author(s):  
Kuldeep Awasthi ◽  
Desireddy Shashidhar Reddy ◽  
Mohd. Kaleem Khan
Keyword(s):  
Optical Axis ◽  
Spherical Aberration ◽  
Spherical Surface ◽  
Fresnel Lens ◽  
High Concentration ◽  
Aperture Diameter ◽  
Convex Lens ◽  
Flat Base ◽  
Fresnel Lenses ◽  
Outer Vertex

Abstract This paper describes the design methodology for a novel Fresnel lens. The original Fresnel lens is obtained from a plano-convex lens, whose spherical surface is split into a number of divisions (called facets), collapsed onto the flat base. Thus, all the facets of the original Fresnel lens have the same radius as that of the plano-convex lens. The proposed design aims to achieve better ray concentration and reduced spherical aberration than the original Fresnel lens by constructing spherical facets with unequal radii. The centers and radii of facets are constrained so that the ray refracted from the bottom vertex of each facet on one side of the optical axis and the ray refracted from the outer vertex of the corresponding facet on the other side of the optical axis must intersect at the focal plane. The proposed lens design has resulted in a 275% gain in the concentration ratio and a 72.5% reduction in the spherical aberration compared to the original lens of the same aperture diameter and number of facets. The performance of both novel and original Fresnel lenses when used as solar concentrators with a conical coil receiver is evaluated. The novel Fresnel lens led to increased heat gain and resulted in a compact solar collector design.

scholarly journals Slovene-English Contrastive Phraseology: Lexical Collocations

2010 ◽  
Vol 7 (2) ◽  
pp. 57-73
Author(s):  
Primož Jurko
Keyword(s):  
English Language ◽  
Focal Point ◽  
Systematic Classification ◽  
Lexical Collocations ◽  
The Difference ◽  
Translation Errors ◽  
Language Pair

Phraseology is seen as one of the key elements and arguably the most productive part of any language. %e paper is focused on collocations and separates them from other phraseological units, such as idioms or compounds. Highlighting the difference between a monolingual and a bilingual (i.e. contrastive) approach to collocation, the article presents two distinct classes of collocations: grammatical and lexical. %e latter, treated contrastively, represent the focal point of the paper, since they are an unending source of translation errors to both students of translation and professional translators. %e author introduces a methodology of systematic classification of lexical collocations applied on the Slovene-English language pair and based on structural (lexical congruence) and semantic (translational predictability) criteria.

scholarly journals Influence of the Heat Dissipation Mode of Long-Flute Cutting Tools on Temperature Distribution during HFCVD Diamond Films

Crystals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 394
Author(s):  
Zhang ◽  
Qian ◽  
wang ◽  
Huang ◽  
Zhang ◽  
...  
Keyword(s):  
Heat Dissipation ◽  
Focal Point ◽  
Cutting Tools ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Decisive Role ◽  
Diamond Coatings ◽  
The Difference ◽  
The Individual

The distribution of substrate temperature plays a decisive role on the uniformity of polycrystalline diamond films on cemented carbide tools with a long flute, prepared by a hot filament chemical vapor deposition (HFCVD). In this work, the heat dissipation mode at the bottom of tools is a focal point, and the finite volume method (FVM) is conducted to simulate and predict the temperature field of tools, with the various materials of the holder placed under the tools. The simulation results show that the thermal conductivity of the holder affects the temperature difference of the individual tools greatly, but only affects the temperature of different tools at the same XY plane slightly. Moreover, the ceramic holder can reduce the difference in temperature of an individual tool by 54%, compared to a copper one. Afterwards, the experiments of the deposition of diamond films is performed using the preferred ceramic holder. The diamond coatings on the different positions present a highly uniform distribution on their grain size, thickness, and quality.

Solar Thermal Electrolytic Process for the Production of Zn From ZnO: The Electrolysis of ZnO From 1275–1500 K

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
R. Schroeder ◽  
L. Matthews ◽  
D. Leatzow ◽  
J. Kondratko ◽  
J. Will ◽  
...  
Keyword(s):  
Focal Point ◽  
Operating Temperature ◽  
Solar Thermal ◽  
Solar Furnace ◽  
Solvent Mixtures ◽  
Temperature Range ◽  
Solar Fraction ◽  
Current Densities ◽  
The Difference ◽  
Solar Receiver

The solar thermal electrolytic production of Zn from ZnO was studied in the temperature range of 1275–1500 K in a cavity-solar receiver located at the focal point of a concentrating solar furnace. This study establishes how cathode material, solvent, current levels, and operating temperature influence the electrolytic cell’s performance. For a nominal current density of 0.1 A cm− 2 at temperatures from 1275 to 1425 K, we found that our performance parameters, the back work ratio and substituted-solar fraction, are within 25% and 20% of the ideal values, respectively. This behavior was true whether the cathode was Mo or W and whether the electrolyte was pure cryolite or a 35 mol. % cryolite-CaF2 mixture. When the electrolytes were cryolite-CaF2 mixtures in the temperature range of 1275–1425 K, there was no measurable difference in the performance, but at 1500 K with a MgF2 electrolyte, the performance dropped significantly. We have some evidence that the performance of the cell is better at current densities above 0.1 A cm− 2 when the cathode is Mo as opposed to W. Furthermore, the difference in the performance values can be attributed to higher kinetic over voltages associated with W versus Mo as a cathode. Our data also suggest that kinetic over voltages increase as the operating temperature increases. The experimental evidence suggests the reaction mechanism at the cathode for ZnO in cryolite involves a reaction between Na+  and ZnF2, and the anode reaction involves a reaction between the anions Al2OF62−  and ZnO22− . Both Mo and W worked as cathode materials, but both the Mo and the W became brittle. Pt worked well as an anode without showing any evidence of degradation. Our SiC crucible may have suffered some carbothermic reaction with ZnO at temperatures exceeding 1275 K, with solvent mixtures of cryolite, CaF2, and MgF2.

Welding of Austenitic Stainless Steel AISI 304 by Fiber Laser

2017 ◽  
Vol 891 ◽  
pp. 190-194
Author(s):  
Katarína Bártová ◽  
Mária Dománková ◽  
Jozef Bárta
Keyword(s):  
Fiber Laser ◽  
Welding Speed ◽  
Focal Point ◽  
Weld Bead ◽  
Bead Width ◽  
Statistical Software ◽  
Aisi 304 ◽  
Depth Measurement ◽  
Point Position ◽  
The Difference

Paper deals with the welding of AISI 304 thin sheets with the thickness of 1 mm by fiber laser. Statistical software MiniTab was used for planning the experiment. The influence of laser power, welding speed and focal point position on width and depth of weld bead was examined. Output power, welding speed and focus point position were used as variable factors for DOE. Samples were prepared by standard metallography. Weld bead width and depth were evaluated. Statistical results were afterward verified by welding reference samples with material the thickness of 0.25 mm. The difference between real width of weld bead and predicted width obtained from statistical software was 8.26 %. In case of weld depth measurement, the difference was 23 %.

A Novelty Analysis Method of Solar-Pumped Laser with Fresnel Lens and Cr/Nd:YAG Ceramic

2014 ◽  
Vol 1015 ◽  
pp. 147-150
Author(s):  
Yu Lu ◽  
Zuo Chun Shen
Keyword(s):  
Solar Radiation ◽  
Experimental Method ◽  
Fresnel Lens ◽  
Laser Output ◽  
Experimental Setup ◽  
Analysis Method ◽  
Pumping Power ◽  
Conical Cavity ◽  
Effective Threshold ◽  
Output Performance

In this paper, the simple and effective experimental method is proposed for studying on the influence of tracing deviation on solar-pumped laser output performance. The threshold pumping power is obtained by the novelty method. The experimental setup of solar-pumped laser employed Fresnel lens of 1.4×1.05m2 and diffuse reflective conical cavity focusing solar radiation on the size of 5mm×60mm Cr/Nd:YAG ceramic. The effective threshold pumping power calculated is 190W, which is about 30% lower than reported results.

scholarly journals Superior component position during robotic-assisted Oxford unicompartmental knee arthroplasty (UKA) compared with conventional technique: A 5-year follow-up study

2020 ◽  
Author(s):  
Tianwei Zhang ◽  
E Cai ◽  
Zhenxiang Zhang ◽  
Hongmei Dou
Keyword(s):  
Mechanical Axis ◽  
Twist Angle ◽  
Clinical Results ◽  
Conventional Technique ◽  
Robotic Assistance ◽  
Component Position ◽  
Robotic Assisted ◽  
Long Term Follow Up ◽  
The Difference

Abstract BackgroundThe purpose of our present work was to compare robotic-assisted UKA and conventional UKA regarding the clinical and radiographic results at 5-year follow-up.MethodsForty-one medial UKAs were conducted with robotic assistance (group ROA) between January 2010 and January 2015, and these subjects were matched with 44 subjects undergoing medial UKAs using the same prosthesis, implanted by conventional technique (group CON). In a 5-year follow-up, subjects were clinically evaluated by using Knee Society functional (KSF), Knee Society clinical (KSC), and Knee Society pain (KSP) scores. Radiographic assessments with regards to coronal mechanical axis (CMA) and condylar twist angle (CTA) were compared between group ROA and group CON.ResultsIn the evaluation, the mechanical limb alignment was significantly increased after operation in each group. The implantation accuracy of the coronal mechanical axis was similar in both groups. As for the evaluation of femoral rotation, the internal rotation in group ROA was remarkably less than that in group CON. The difference was not significant in KSP, KSF, KSC scores between group ROA and group CON.ConclusionOur results showed that robotic assistance improves component position without gaining superior CMA or increasing clinical results versus conventional UKA at 5-year follow-up. To conclude, using robotic assistance in UKA is recommended as compared to conventional UKA. Long-term follow-up will be needed to draw conclusion about the overall outcomes of robotic assistance as compared with conventional technique.Trial registrationCurrent Controlled Trials ChiCTR2000033918. Registered 16 June 2020.

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