Implementation of a qualitative test for a Fresnel lens

2019 ◽  
Author(s):  
Maximino Avendaño-Alejo ◽  
Martín Jiménez-Rodríguez ◽  
Gabriel Castillo-Santiago ◽  
María del Carmen López-Bautista
Keyword(s):  
Fresnel Lens ◽  
Qualitative Test

Far-Infrared Fresnel Lens for Thermal Imaging

2013 ◽  
Vol 133 (7) ◽  
pp. 274-279
Author(s):  
Tomoyuki Takahata ◽  
Kiyoshi Matsumoto ◽  
Isao Shimoyama
Keyword(s):  
Thermal Imaging ◽  
Far Infrared ◽  
Fresnel Lens

PENGARUH LAMA FERMENTASI TERHADAP KADAR FLAVONOID TOTAL PADA EKSTRAK TAPE BIJI NANGKA (Artocarpus heterophylla Lamk.)

2020 ◽  
pp. 53-61
Author(s):  
Nada Nabila Sari ◽  
S Suharyanto
Keyword(s):  
Extraction Method ◽  
Positive Sample ◽  
Total Flavonoid ◽  
Test Results ◽  
Fermentation Time ◽  
Flavonoid Compounds ◽  
Community People ◽  
Qualitative Test ◽  
Seed Extracts

Biji nangka kurang diminati oleh masyarakat sebagai bahan pangan. Biji nangka memiliki kandungan senyawa flavonoid yang dapat digunakan sebagai pengobatan. Tujuan peneliti adalah untuk mengetahui pengaruh lama fermentasi terhadap kadar flavonoid total pada ekstrak tape biji nangka (Artocarpus heterophylla Lamk.) yang dilakukan dengan alat spektrofotometer UV-Vis. Manfaat dari penelitian untuk menambah wawasan di bidang farmasi khususnya tentang ilmu kimia amami mengenai pengaruh lama fermentasi terhadap kadar flavonoid total pada ekstrak tape biji nangka (Artocarpus heterophylla Lamk.). Metode ekstraksi yang digunakan adalah metode maserasi dengan mengunakan pelarut etanol 96%. Identifikasi kualitatif mengunakan uji Shinoda, uji NaOH 10%, uji H2SO4 (pekat). Hasil uji kualitatif menunjukan sampel positif mengandung flavonoid. Kesimpulan pada hasil penelitian penetapan kadar flavonoid total yang terkandung dalam ekstrak tape biji nangka pada hari ke-0 sebesar 2,9146±0,0245 mgQE/gram ekstrak, pada hari ke-1 sebesar 3,3050±0,0240 mgQE/gram ekstrak, pada hari ke-2 sebesar 3,6829±0,0244 mgQE/gram ekstrak, dan pada hari ke-3 sebesar 4,0488±0,0244 mgQE/gram ekstrak.  Jackfruit seeds are less interest by the community (people) as food.  Jackfruit seeds containing flavonoid compounds where it can be used as a treatment.  The aim of the researchers was to determine the effect of fermentation time on total flavonoid concentration  in jackfruit fermented seed extracts with a UV-Vis spectrophotometer. The benefits of research to add insight in the field of pharmacy especially about chemistry of amami regarding effect of fermentation time on total flavonoid levels in jackfruit seed “tape” extract (Artocarpus heterophylla Lamk.). Extraction method used is the maceration method using 96% ethanol solvent. Qualitative identification using the Shinoda test, 10% NaOH test, and H2SO4 (concentrated) test. Qualitative test results showed a positive sample containing flavonoids. Conclusions on the results of the experiment  are jackfruit seed "tape" extract on day-0 was 2.9146±0.0245  mgQE/gram extract, on day-1 was 3.3050±0.0240 mgQE/gram extract, on day-2 was 3.68293±0.0244 mgQE/gram and on day-3 was 4.0488±0.024 mgQE /gram extract. The longer fermentation, total flavonoid concentration interest.  

scholarly journals Electrical Tuning of Fresnel Lens in Reflection

ACS Photonics ◽  
2021 ◽  
Author(s):  
Christopher Damgaard-Carstensen ◽  
Martin Thomaschewski ◽  
Fei Ding ◽  
Sergey I. Bozhevolnyi
Keyword(s):  
Fresnel Lens

Design and Evaluation of the Fresnel-Lens Based Solar Concentrator System Through a Statistical-Algorithmic Approach

2018 ◽  
Author(s):  
Hassan Qandil ◽  
Weihuan Zhao
Keyword(s):  
High Temperature ◽  
High Efficiency ◽  
Incident Light ◽  
Thermal Analyses ◽  
Solar Spectrum ◽  
Chromatic Aberration ◽  
Fresnel Lens ◽  
Optimum Number ◽  
Solar Concentrator ◽  
Receiver System

A novel non-imaging Fresnel-lens-based solar concentrator-receiver system has been investigated to achieve high-efficiency photon and heat outputs with minimized effect of chromatic aberrations. Two types of non-imaging Fresnel lenses, a spot-flat lens and a dome-shaped lens, are designed through a statistical algorithm incorporated in MATLAB. The algorithm optimizes the lens design via a statistical ray-tracing methodology of the incident light, considering the chromatic aberration of solar spectrum, the lens-receiver spacing and aperture sizes, and the optimum number of prism grooves. An equal-groove-width of the Poly-methyl-methacrylate (PMMA) prisms is adopted in the model. The main target is to maximize ray intensity on the receiver’s aperture, and therefore, achieve the highest possible heat flux and output concentration temperature. The algorithm outputs prism and system geometries of the Fresnel-lens concentrator. The lenses coupled with solar receivers are simulated by COMSOL Multiphysics. It combines both optical and thermal analyses for the lens and receiver to study the optimum lens structure for high solar flux output. The optimized solar concentrator-receiver system can be applied to various devices which require high temperature inputs, such as concentrated photovoltaics (CPV), high-temperature stirling engine, etc.

scholarly journals Optical Performance of Single Point-Focus Fresnel Lens Concentrator System for Multiple Multi-Junction Solar Cells—A Numerical Study

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4301
Author(s):  
Yassir A. Alamri ◽  
Saad Mahmoud ◽  
Raya Al-Dadah ◽  
Shivangi Sharma ◽  
J. N. Roy ◽  
...  
Keyword(s):  
Solar Cells ◽  
Numerical Study ◽  
Single Point ◽  
Optical Element ◽  
Fresnel Lens ◽  
Electrical Performance ◽  
High Concentration ◽  
Three Dimensional Model ◽  
Optical Efficiency ◽  
Concave Lens

This paper investigates the potential of a new integrated solar concentrated photovoltaic (CPV) system that uses a solo point focus Fresnel lens for multiple multi-junction solar cells (MJSCs). The proposed system comprises of an FL concentrator as the primary optical element, a multi-leg homogeniser as the secondary optical element (SOE), a plano-concave lens, and four MJSCs. A three-dimensional model of this system was developed using the ray tracing method to predict the influence of aperture width, height, and position with respect to MJSCs of different reflective and refractive SOE on the overall optical efficiency of the system and the irradiance uniformity achieved on the MJSCs’ surfaces. The results show that the refractive homogeniser using N-BK7 glass can achieve higher optical efficiency (79%) compared to the reflective homogeniser (57.5%). In addition, the peak to average ratio of illumination at MJSCs for the reflective homogeniser ranges from 1.07 to 1.14, while for the refractive homogeniser, it ranges from 1.06 to 1.34, causing minimum effects on the electrical performance of the MJSCs. The novelty of this paper is the development of a high concentration CPV system that integrates multiple MJSCs with a uniform distribution of rays, unlike the conventional CPV systems that utilise a single concentrator onto a single MJSC. The optical efficiency of the CPV system was also examined using both the types of homogeniser (reflective and refractive).

scholarly journals Analysis of spectral irradiance blurring by Fresnel lens sunlight concentrators

2019 ◽  
Vol 1400 ◽  
pp. 066059
Author(s):  
E D Filimonov ◽  
S A Levina ◽  
M Z Shvarts
Keyword(s):  
Fresnel Lens ◽  
Spectral Irradiance

Solar Thermophotovoltaic Converters Based on Tungsten Emitters

2006 ◽  
Vol 129 (3) ◽  
pp. 298-303 ◽  
Author(s):  
V. M. Andreev ◽  
A. S. Vlasov ◽  
V. P. Khvostikov ◽  
O. A. Khvostikova ◽  
P. Y. Gazaryan ◽  
...  
Keyword(s):  
Band Gap ◽  
High Efficiency ◽  
Radiation Spectrum ◽  
Cost Effective ◽  
Fresnel Lens ◽  
Photocurrent Density ◽  
Back Side ◽  
High Concentration ◽  
Emitter System ◽  
Solar Powered

Results of a solar thermophotovoltaic (STPV) system study are reported. Modeling of the STPV module performance and the analysis of various parameters influencing the system are presented. The ways for the STPV system efficiency to increase and their magnitude are considered such as: improvement of the emitter radiation selectivity and application of selective filters for better matching the emitter radiation spectrum and cell photoresponse; application of the cells with a back side reflector for recycling the sub-band gap photons; and development of low-band gap tandem TPV cells for better utilization of the radiation spectrum. Sunlight concentrator and STPV modules were designed, fabricated, and tested under indoor and outdoor conditions. A cost-effective sunlight concentrator with Fresnel lens was developed as a primary concentrator and a secondary quartz meniscus lens ensured the high concentration ratio of ∼4000×, which is necessary for achieving the high efficiency of the concentrator–emitter system owing to trap escaping radiation. Several types of STPV modules have been developed and tested under concentrated sunlight. Photocurrent density of 4.5A∕cm2 was registered in a photoreceiver based on 1×1cm2GaSb cells under a solar powered tungsten emitter.

scholarly journals Simple qualitative test for artificial butter

Science ◽  
1887 ◽  
Vol ns-9 (209) ◽  
pp. 114-114
Author(s):  
H. W. Wiley
Keyword(s):  
Qualitative Test
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