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Stamford J, Kasznicki P, Lawson T. Spectral Reflectance Measurements. Methods Mol Biol 2024; 2790:333-353. [PMID: 38649579 DOI: 10.1007/978-1-0716-3790-6_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
This chapter provides a methodology for evaluating plant health and leaf characteristics using spectral reflectance. It provides a step-by-step guide to using spectrometers for high-resolution point measurements of leaf spectral reflectance and multispectral imaging for capturing spatial data, emphasizing the importance of consistent measurement conditions. The chapter further explores the intricacies of multispectral imaging, including calibration, data collection, and image processing. Finally, this chapter delves into the application of various spectral indices for the quantification of key traits such as pigment content, the status of the xanthophyll cycle, water content, and how to identify spectral regions of interest for further research and development. Serving as a guide for researchers and practitioners in plant science, this chapter provides a straightforward framework for plant health assessment using spectral reflectance.
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Affiliation(s)
- John Stamford
- School of Life Sciences, University of Essex, Colchester, UK
| | - Piotr Kasznicki
- School of Life Sciences, University of Essex, Colchester, UK
| | - Tracy Lawson
- School of Life Sciences, University of Essex, Colchester, UK.
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2
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Bachir W, Ismael FS, Alaineya NHA. Laser spectroscopic method for remote sensing of respiratory rate. Phys Eng Sci Med 2023; 46:1249-1258. [PMID: 37358781 PMCID: PMC10480269 DOI: 10.1007/s13246-023-01292-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 06/16/2023] [Indexed: 06/27/2023]
Abstract
Noncontact sensing methods for measuring vital signs have recently gained interest, particularly for long-term monitoring. This study introduces a new method for measuring respiratory rate remotely. The proposed method is based on the reflection of a laser beam off a striped card attached to a moving platform simulating chest wall displacements. A wide range of frequencies (n = 35) from 0.06 to 2.2 Hz corresponding to both normal and pathological human respiratory rates were simulated using a moving mechanical platform. Reflected spectra (n = 105) were collected by a spectrometer in a dynamic mode. Fourier analysis was performed to retrieve the breathing frequency. The results show a striking agreement between measurements and reference frequencies. The results also show that low frequencies corresponding to respiratory rates can be detected with high accuracy (uncertainty is well below 5%). A validation test of the measuring method on a human subject demonstrated a great potential for remote respiration rate monitoring of adults and neonates in a clinical environment.
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Affiliation(s)
- Wesam Bachir
- Institute of Metrology and Biomedical Engineering, Faculty of Mechatronics, Warsaw University of Technology, Św. A. Boboli 8 St, 02-525, Warsaw, Poland.
- Biomedical Photonics Laboratory, Higher Institute for Laser Research and Applications, Damascus University, Damascus, Syria.
| | - Fatimah Samie Ismael
- Biomedical Photonics Laboratory, Higher Institute for Laser Research and Applications, Damascus University, Damascus, Syria
| | - Nour Hasan Arry Alaineya
- Biomedical Photonics Laboratory, Higher Institute for Laser Research and Applications, Damascus University, Damascus, Syria
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3
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Jeon D, Shin K, Moon SW, Rho J. Recent advancements of metalenses for functional imaging. Nano Converg 2023; 10:24. [PMID: 37222959 DOI: 10.1186/s40580-023-00372-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 05/07/2023] [Indexed: 05/25/2023]
Abstract
Metasurfaces can modulate light with periodically arranged subwavelength scatterers, and they can generate arbitrary wavefronts. Therefore, they can be used to realize various optical components. In particular, metasurfaces can be used to realize lenses, so-called metalenses. In the last decade, metalenses have been actively studied and developed. In this review, we firstly introduce the fundamental principles of metalenses in terms of materials, phase modulation method, and design method. Based on these principles, the functionalities and the applications can consequently be realized. Metalenses have a much larger number of degrees of freedom compared with that of existing refractive or diffractive lenses. Thus, they afford functionalities such as tunability, high numerical aperture, and aberration correction. Metalenses with these functionalities can be applied in various optical systems such as imaging systems and spectrometers. Finally, we discuss the future applications of metalenses.
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Affiliation(s)
- Dongmin Jeon
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Kilsoo Shin
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Seong-Won Moon
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang, 37673, Republic of Korea.
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Bethge H, Winkelmann T, Lüdeke P, Rath T. Low-cost and automated phenotyping system "Phenomenon" for multi-sensor in situ monitoring in plant in vitro culture. Plant Methods 2023; 19:42. [PMID: 37131210 PMCID: PMC10152611 DOI: 10.1186/s13007-023-01018-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 04/14/2023] [Indexed: 05/04/2023]
Abstract
BACKGROUND The current development of sensor technologies towards ever more cost-effective and powerful systems is steadily increasing the application of low-cost sensors in different horticultural sectors. In plant in vitro culture, as a fundamental technique for plant breeding and plant propagation, the majority of evaluation methods to describe the performance of these cultures are based on destructive approaches, limiting data to unique endpoint measurements. Therefore, a non-destructive phenotyping system capable of automated, continuous and objective quantification of in vitro plant traits is desirable. RESULTS An automated low-cost multi-sensor system acquiring phenotypic data of plant in vitro cultures was developed and evaluated. Unique hardware and software components were selected to construct a xyz-scanning system with an adequate accuracy for consistent data acquisition. Relevant plant growth predictors, such as projected area of explants and average canopy height were determined employing multi-sensory imaging and various developmental processes could be monitored and documented. The validation of the RGB image segmentation pipeline using a random forest classifier revealed very strong correlation with manual pixel annotation. Depth imaging by a laser distance sensor of plant in vitro cultures enabled the description of the dynamic behavior of the average canopy height, the maximum plant height, but also the culture media height and volume. Projected plant area in depth data by RANSAC (random sample consensus) segmentation approach well matched the projected plant area by RGB image processing pipeline. In addition, a successful proof of concept for in situ spectral fluorescence monitoring was achieved and challenges of thermal imaging were documented. Potential use cases for the digital quantification of key performance parameters in research and commercial application are discussed. CONCLUSION The technical realization of "Phenomenon" allows phenotyping of plant in vitro cultures under highly challenging conditions and enables multi-sensory monitoring through closed vessels, ensuring the aseptic status of the cultures. Automated sensor application in plant tissue culture promises great potential for a non-destructive growth analysis enhancing commercial propagation as well as enabling research with novel digital parameters recorded over time.
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Affiliation(s)
- Hans Bethge
- Laboratory for Biosystems Engineering, Faculty of Agricultural Sciences and Landscape Architecture, Osnabrück University of Applied Sciences, Oldenburger Landstraße 24, 49090, Osnabrück, Germany.
- Institute of Horticultural Production Systems, Section of Woody Plant and Propagation Physiology, Leibniz Universität Hannover, Herrenhäuser Str. 2, 30419, Hannover, Germany.
| | - Traud Winkelmann
- Institute of Horticultural Production Systems, Section of Woody Plant and Propagation Physiology, Leibniz Universität Hannover, Herrenhäuser Str. 2, 30419, Hannover, Germany
| | | | - Thomas Rath
- Laboratory for Biosystems Engineering, Faculty of Agricultural Sciences and Landscape Architecture, Osnabrück University of Applied Sciences, Oldenburger Landstraße 24, 49090, Osnabrück, Germany
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Sawa M, Mizuochi M, Matsumura K, Aihara M, Yamagami S, Yamashita H, Kaburaki T. A novel instrument to determine hue discrimination. Jpn J Ophthalmol 2023; 67:353-360. [PMID: 36961660 DOI: 10.1007/s10384-023-00983-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 01/18/2023] [Indexed: 03/25/2023]
Abstract
PURPOSE We report and verify a novel hue discrimination instrument. We also investigate its efficiency to determine hue discrimination in persons with normal color vision. STUDY DESIGN Experimental and clinical investigation. METHOD AND STUDY PARTICIPANTS The instrument setup comprises an optical unit and examination unit. The optical unit is composed of the same 2 spectrometers and their controllers, which enables the independent emission of different spectral lights. Two independent bundle fibers connect the optical unit and the examination unit. Two different wavelength lights are illuminated on the bipartite upper and lower circular objectives with a visual angle of 2 degrees in the examination unit. The examinee recognizes the difference in the spectral lights between the bipartite targets. Persons with normal color vision are examined and the findings are confirmed using the Ishihara Test for Colour Deficiency. RESULTS The instrument could generate spectral light from 450 to 650 nm within 2-nm accuracy. The spectral light showed a different light intensity according to the spectral centroid, ranging from 450 to 650 nm, but the difference could be adjusted and was negligible in terms of determination of hue discrimination using the power meter. Three width slits, 0.2 mm, 0.5 mm, and 1.0 mm, to homogenize the light path were investigated. The half-width wavelength was accurate on each spectral centroid; however, the 0.5 mm slit was suitable to generate an efficient light path. The hue discrimination differed among the study participants. In general, at short and long wavelength lights, the hue discrimination range was large: about 15 nm at 450 nm and about 10 nm at 650 nm. Between 470 and 620 nm, the hue discrimination showed good sensitivity and specificity between 8 and 2 nm depending on the targeting wavelength lights. Intraindividual variation was small, ranging from 3 to 1 nm, thus indicating good repeatability. The time to examine the hue discrimination was about 20 min. CONCLUSION This newly invented instrument using two independent spectrometer units enabled the determination of hue discrimination. The instrument's sensitivity and specificity including its repeatability were confirmed and indicated that the instrument could be a clinically applicable method.
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Affiliation(s)
- Mitsuru Sawa
- Public Interest Incorporated Foundation Isshinkai, Tokyo, Japan.
- Nihon University, Tokyo, Japan.
| | | | | | - Makoto Aihara
- Public Interest Incorporated Foundation Isshinkai, Tokyo, Japan
- University of Tokyo, Tokyo, Japan
| | - Satoru Yamagami
- Public Interest Incorporated Foundation Isshinkai, Tokyo, Japan
- Nihon University, Tokyo, Japan
| | - Hidetoshi Yamashita
- Public Interest Incorporated Foundation Isshinkai, Tokyo, Japan
- Yamagata University, Yamagata, Japan
| | - Toshikatsu Kaburaki
- Public Interest Incorporated Foundation Isshinkai, Tokyo, Japan
- Jichi Medical University Saitama Medical Center, Omiya, Japan
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Bauer A, Elamurugan S, Tolba SA, Fatima, Nega E, Lima IT, Xia W, Sun D. A portable elliptical dichroism spectrometer targeting secondary structural features of tumorous protein for pancreatic cancer detection. Biosens Bioelectron 2023; 222:114934. [PMID: 36455371 PMCID: PMC9792437 DOI: 10.1016/j.bios.2022.114934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/11/2022] [Accepted: 11/17/2022] [Indexed: 11/25/2022]
Abstract
Stereochemical analysis is essential for understanding the complex function of biomolecules. Various direct and indirect approaches can be used to explore the allosteric configuration. However, the size, cost, and delicate nature of these systems limit their biomedical usage. Here, we constructed elliptical dichroism (ED) spectrometer for biomedical applications, whose performance is validated by experiment and theoretical simulation (Jones/Mueller calculus and time-dependent density-functional theory). Instead of complicated control of circular polarization, ED spectrometer adopted the absorbance of left- and right-oriented elliptically polarized light. With a simplified design, we demonstrated the potential of ED spectrometry as an alternative for secondary structural analysis of biomolecules, their conformation and chirality. It not only provides a portable, low-cost alternative to the sophisticated instruments currently used for structural analysis of biomolecules but also provides superior translational features: low sample consumption(200 μl), easy operation, and multiple working modes, for noninvasive cancer detection.
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Affiliation(s)
- Aaron Bauer
- Biomedical Engineering Program, North Dakota State University, 1401 Centennial Blvd, Engineering Administration, Room 203, Fargo, ND, 58102, USA
| | - Santhalingam Elamurugan
- Biomedical Engineering Program, North Dakota State University, 1401 Centennial Blvd, Engineering Administration, Room 203, Fargo, ND, 58102, USA
| | - Sara A Tolba
- Materials and Nanotechnology Program, North Dakota State University, 1410 North 14th Avenue, CIE 201, Fargo, ND, 58102, USA
| | - Fatima
- Department of Mathematics, Computer Science and Physics, Roanoke College, Salem, VA, 24153, USA; Department of Civil, Construction and Environmental Engineering, North Dakota State University, 1410 North 14th Avenue, CIE 201, Fargo, ND, 58102, USA
| | - Ejjigu Nega
- Biomedical Engineering Program, North Dakota State University, 1401 Centennial Blvd, Engineering Administration, Room 203, Fargo, ND, 58102, USA
| | - Ivan T Lima
- Department of Electrical and Computer Engineering, North Dakota State University, 1411 Centennial Blvd., 101S, Fargo, ND, 58102, USA
| | - Wenjie Xia
- Biomedical Engineering Program, North Dakota State University, 1401 Centennial Blvd, Engineering Administration, Room 203, Fargo, ND, 58102, USA; Materials and Nanotechnology Program, North Dakota State University, 1410 North 14th Avenue, CIE 201, Fargo, ND, 58102, USA; Department of Civil, Construction and Environmental Engineering, North Dakota State University, 1410 North 14th Avenue, CIE 201, Fargo, ND, 58102, USA
| | - Dali Sun
- Biomedical Engineering Program, North Dakota State University, 1401 Centennial Blvd, Engineering Administration, Room 203, Fargo, ND, 58102, USA; Department of Electrical and Computer Engineering, North Dakota State University, 1411 Centennial Blvd., 101S, Fargo, ND, 58102, USA.
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Basu Thakur R, Steiger A, Shu S, Faramarzi F, Klimovich N, Day PK, Shirokoff E, Mauskopf PD, Barry PS. Development of Superconducting On-chip Fourier Transform Spectrometers. J Low Temp Phys 2022; 211:1-10. [PMID: 36474505 PMCID: PMC9716503 DOI: 10.1007/s10909-022-02920-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 11/01/2022] [Indexed: 06/17/2023]
Abstract
Superconducting On-chip Fourier Transform Spectrometers (SOFTS) are broadband, ultra-compact and electronic interferometers. SOFTS will enable kilo-pixel spectro-imaging focal planes, enhancing sub-millimeter astrophysics and cosmology. Particular applications include cluster astrophysics, cosmic microwave background (CMB) science, and line intensity mapping. This article details the development, design and bench-marking of radio frequency (RF) on-chip architecture of SOFTS for Ka and W-bands.
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Affiliation(s)
- Ritoban Basu Thakur
- Department of Physics, California Institute of Technology, Pasadena, 91125 CA USA
- Jet Propulsion Laboratory (NASA), 4800 Oak Grove Dr, Pasadena, 91109 CA USA
| | - A. Steiger
- Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave, Chicago, IL 60637 USA
- Department of Astronomy & Astrophysics, University of Chicago, 5640 S. Ellis Ave., Chicago, IL 60637 USA
| | - S. Shu
- Department of Physics, California Institute of Technology, Pasadena, 91125 CA USA
- Jet Propulsion Laboratory (NASA), 4800 Oak Grove Dr, Pasadena, 91109 CA USA
| | - F. Faramarzi
- Department of Physics, School of Earth & Space Exploration, Arizona State University, Tempe, AZ 85281 USA
| | - N. Klimovich
- Department of Physics, California Institute of Technology, Pasadena, 91125 CA USA
- Jet Propulsion Laboratory (NASA), 4800 Oak Grove Dr, Pasadena, 91109 CA USA
| | - P. K. Day
- Jet Propulsion Laboratory (NASA), 4800 Oak Grove Dr, Pasadena, 91109 CA USA
| | - E. Shirokoff
- Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave, Chicago, IL 60637 USA
- Department of Astronomy & Astrophysics, University of Chicago, 5640 S. Ellis Ave., Chicago, IL 60637 USA
| | - P. D. Mauskopf
- Department of Physics, School of Earth & Space Exploration, Arizona State University, Tempe, AZ 85281 USA
| | - P. S. Barry
- Argonne National Laboratory, HEP Division, 9700 South Cass Avenue, Argonne, IL 60439 USA
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Kong L, Zhao Q, Wang H, Guo J, Lu H, Hao H, Guo S, Tu X, Zhang L, Jia X, Kang L, Wu X, Chen J, Wu P. Single-Detector Spectrometer Using a Superconducting Nanowire. Nano Lett 2021; 21:9625-9632. [PMID: 34730364 DOI: 10.1021/acs.nanolett.1c03393] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Designing a spectrometer without the need for wavelength multiplexing optics can effectively reduce the complexity and physical footprint. On the basis of the computational spectroscopic strategy and combining a broadband-responsive dynamic detector, we successfully demonstrate an optics-free single-detector spectrometer that maps the tunable quantum efficiency of a superconducting nanowire into a matrix to build a solvable mathematical equation. Such a spectrometer can realize a broadband spectral responsivity ranging from 660 to 1900 nm. The spectral resolution at the telecom is sub-10 nm, exceeding the energy resolving capacity of existing infrared single-photon detectors. Meanwhile, benefiting from the optics-free setup, precise time-of-flight measurements can be simultaneously achieved. We have demonstrated a spectral LiDAR with eight spectral channels. This spectrometer scheme paves the way for applying superconducting nanowire detectors in multifunctional spectroscopy and represents a conceptual advancement for on-chip spectroscopy and spectral imaging.
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Affiliation(s)
- Lingdong Kong
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Qingyuan Zhao
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
- Purple Mountain Laboratories, Nanjing, Jiangsu 211111, China
| | - Hui Wang
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Jiawei Guo
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Haiyangbo Lu
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Hao Hao
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Shuya Guo
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Xuecou Tu
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
- Purple Mountain Laboratories, Nanjing, Jiangsu 211111, China
| | - Labao Zhang
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
- Purple Mountain Laboratories, Nanjing, Jiangsu 211111, China
| | - Xiaoqing Jia
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
- Purple Mountain Laboratories, Nanjing, Jiangsu 211111, China
| | - Lin Kang
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
- Purple Mountain Laboratories, Nanjing, Jiangsu 211111, China
| | - Xinglong Wu
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, 210023, China
| | - Jian Chen
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
- Purple Mountain Laboratories, Nanjing, Jiangsu 211111, China
| | - Peiheng Wu
- Research Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
- Purple Mountain Laboratories, Nanjing, Jiangsu 211111, China
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Abstract
Purpose To evaluate the effect of glass-reinforced ceramics (leucite and lithium disilicate) with different thicknesses (1, 2, and 3 mm) on the wavelength and irradiance spectrum of blue and violet lights. In addition, the effect of the ceramics on four current light-curing units (LCUs) was evaluated: a halogen lamp, a single peak LED, and two multi-peak LEDs.Methods Ceramic discs of different thicknesses (1, 2, and 3 mm) were obtained from computer-aided design and computer-aided manufacturing (CAD-CAM) blocks. The irradiance, radiant exposure, and emission spectrum of the four LCUs were analyzed using a spectrometer-based instrument. To evaluate the violet and blue lights, a specific device that provides a narrow emission spectrum was used.Results The ceramics reduced the irradiance of all the tested LCUs. However, the wavelength of the transmitted light was only altered slightly. The effect of leucite and lithium disilicate varied according to the type of LCU and thickness of the ceramic disc evaluated .Conclusions From the results, it could be concluded that the thickness of the leucite and lithium disilicate ceramic significantly reduced the irradiance of the light emitted by the LCUs, with minimal changes on the wavelength spectrum of the lights. The effects of the ceramic on irradiance and transmitted wavelengths of the blue and violet lights was slightly different.
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Affiliation(s)
- Adriano F Lima
- Dental Research Division, Paulista University, Sao Paulo, Brazil
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10
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Xiao D, Le BT, Ha TTL. Iron ore identification method using reflectance spectrometer and a deep neural network framework. Spectrochim Acta A Mol Biomol Spectrosc 2021; 248:119168. [PMID: 33229210 DOI: 10.1016/j.saa.2020.119168] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/28/2020] [Accepted: 10/30/2020] [Indexed: 06/11/2023]
Abstract
In the first selection stage of iron ore, the ore classification accuracy plays a decisive role in subsequent work. Therefore, how to identify iron ore quickly and accurately is an important task. Traditional chemical, physical and manual identification methods have the disadvantages of high costs and high time consumption. This research proposes a new iron ore identification method, that combines deep learning with visible-infrared reflectance spectroscopy to establish an iron ore classification model. We collected iron ore samples from the Anshan iron ore area and measured the spectral data with a spectrometer. Then, a deep neural network framework is proposed based on the convolution neural network and the improved extreme learning machine algorithm, and an iron ore classification model is established based on the framework. The results show that the proposed model can effectively identify the types of iron ore, and the overall accuracy reaches 98.11%.
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Affiliation(s)
- Dong Xiao
- College of Information Science and Engineering, Northeastern University, Shenyang, 110819, China; Key Laboratory of Intelligent Diagnosis and Safety for Metallurgical Industry, Liaoning Province, Northeastern University, Shenyang 110819, China
| | - Ba Tuan Le
- Institute of Research and Development, Duy Tan University, Da Nang 550000, Viet Nam.
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11
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Liao G, Luo S, Xiao L. Borehole Nuclear Magnetic Resonance Study at the China University of Petroleum. J Magn Reson 2021; 324:106914. [PMID: 33648678 DOI: 10.1016/j.jmr.2021.106914] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 01/15/2021] [Accepted: 01/17/2021] [Indexed: 06/12/2023]
Abstract
The research of borehole nuclear magnetic resonance (NMR) began in the 1950 s, but the maturity and large-scale applications of relevant instruments started in the mid-1990. To date, borehole NMR is an important means for borehole in-situ analysis and oil and gas evaluation, which significantly improves the success rate of exploration and the evaluation accuracy of oil and gas reservoirs. Its development has also contributed importantly to low-field and industrial NMR theories and experimental methodologies. Companies and individuals in the United States, China and other countries have developed the capabilities to engineer and deploy borehole NMR instruments and measurements independently. NMR imaging and evaluation of heterogeneous reservoirs and unconventional oil and gas are worldwide problems, involving the innovation of borehole NMR and the advanced manufacture of instruments and equipment. The commercial technology of borehole oil and gas exploration is highly competitive and proprietary. It is difficult to gain full insight into the details of the technologies and development from published literatures. Based on the research of the author's NMR laboratory at the China University of Petroleum (CUP), this paper reviews the core technologies of borehole NMR and its applications, discusses selected important issues that have not been fully solved, and looks forward to the direction and prospects of future development.
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Affiliation(s)
- Guangzhi Liao
- State Key Lab. of Petroleum Resources and Prospecting, and College of Artificial Intelligence, China University of Petroleum, Beijing 102249, China
| | - Sihui Luo
- State Key Lab. of Petroleum Resources and Prospecting, and College of Artificial Intelligence, China University of Petroleum, Beijing 102249, China
| | - Lizhi Xiao
- State Key Lab. of Petroleum Resources and Prospecting, and College of Artificial Intelligence, China University of Petroleum, Beijing 102249, China.
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12
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Zhen J, Dykstra C, Gouws G, Obruchkov S, Dykstra R. Mobile low field magnetic resonance hardware development. J Magn Reson 2021; 322:106852. [PMID: 33423760 DOI: 10.1016/j.jmr.2020.106852] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 10/09/2020] [Accepted: 10/11/2020] [Indexed: 06/12/2023]
Abstract
Typically, NMR systems are bulky and expensive laboratory based equipment. For half a century after its scientific discovery taking NMR outside of a laboratory environment is still not a common practice due to the complexity of the underlining physical phenomena and its low sensitivity, to the myriad of technical challenges when integrating a complete system. The scarcity of compact and mobile NMR systems has prevented its proliferation into many other areas and applications. This paper describes the progress in the development of compact electronic spectrometers that we coupled with handheld sensors in order to provide complete mobile solutions. The key to this progress has been the modern advances in computing, electronics and permanent magnet technologies. Mobile NMR is now feasible as a valuable, non-invasive tool for industrial and medical applications. By leveraging the strengths of NMR, which is to probe at the molecular level and gain information about molecular structure, organisation, abundance and orientation, NMR is intrinsically suitable for non-destructive testing of a wide range of materials and their manufacturing processes. The development of complete NMR systems benefits from working across various disciplines and organisations. By embracing a collaborative approach we believe it will accelerate NMR technology to become more ubiquitous in the near future.
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Affiliation(s)
- John Zhen
- Resonint Limited, 32 Salamanca Road, Wellington, New Zealand
| | - Cameron Dykstra
- Resonint Limited, 32 Salamanca Road, Wellington, New Zealand
| | - Gideon Gouws
- School of Engineering and Computer Science, Victoria University of Wellington, Wellington, New Zealand
| | - Sergei Obruchkov
- Robinson Research Institute, Victoria University of Wellington, Wellington, New Zealand
| | - Robin Dykstra
- School of Engineering and Computer Science, Victoria University of Wellington, Wellington, New Zealand.
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Laganovska K, Zolotarjovs A, Vázquez M, Mc Donnell K, Liepins J, Ben-Yoav H, Karitans V, Smits K. Portable low-cost open-source wireless spectrophotometer for fast and reliable measurements. HardwareX 2020; 7:e00108. [PMID: 35495213 PMCID: PMC9041175 DOI: 10.1016/j.ohx.2020.e00108] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We demonstrate a low-cost standalone portable spectrophotometer for fast and reliable measurement execution. The data acquired can be both displayed via a dedicated smartphone application or a computer interface, allowing users either to gather and view data on the move or set up a continuous experiment. All design and software files are open-source and are intended for the device to be easily replicable and further customizable to suit specific applications. The assembled device can measure absorption in the wavelength range from 450 nm to 750 nm with a resolution of 15 nm and is housed in a 90 × 85 × 58 mm casing. Validation of the device was carried out by assessing wavelength accuracy, dynamic range and the signal-to-noise ratio of the system, followed by testing in three different applications where limit of quantification, limit of detection and relative standard deviations were determined. The results indicated better performance than low-cost spectrophotometers, on average being comparable to moderate to high-cost spectrophotometers.
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Affiliation(s)
- Katrina Laganovska
- Institute of Solid State Physics, University of Latvia, Kengaraga Str. 8, Riga LV-1063, Latvia
| | - Aleksejs Zolotarjovs
- Institute of Solid State Physics, University of Latvia, Kengaraga Str. 8, Riga LV-1063, Latvia
| | - Mercedes Vázquez
- School of Chemical Sciences, National Centre for Sensor Research, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Kirsty Mc Donnell
- School of Chemical Sciences, National Centre for Sensor Research, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Janis Liepins
- Institute of Microbiology and Biotechnology, University of Latvia, Jelgavas Str. 1, Riga LV-1004, Latvia
| | - Hadar Ben-Yoav
- Department of Biomedical Engineering and Ilse Katz Institute of Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel
| | - Varis Karitans
- Institute of Solid State Physics, University of Latvia, Kengaraga Str. 8, Riga LV-1063, Latvia
| | - Krisjanis Smits
- Institute of Solid State Physics, University of Latvia, Kengaraga Str. 8, Riga LV-1063, Latvia
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14
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Abstract
This study reports a crossed Czerny-Turner spectrometer with multiple mirrors to extend the inspected spectrum. A design example with two movable mirrors and a stationary planar mirror is experimentally demonstrated to offer two additional spectral bands, thereby leading to thrice the spectral range of the original Czerny-Turner spectrometer. The results indicate that the configurations to measure the three bands have almost identical parameters. The moving direction of the planar mirror and the plane of incidence are orthogonal; thus, the influence of mirror movement on the repeatability of the spectrum is minimized. In addition to the merits of cost-effectiveness and rapid inspection, the reported mechanism of mirror movement is applied to general spectrometers to extend the spectral coverage without sacrificing the resolution.
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Affiliation(s)
- Jyh-Rou Sze
- 1 87786 Instrument Technology Research Center, National Applied Research Laboratories, Taiwan, Republic of China
| | - An-Chi Wei
- 2 Graduate Institute of Energy Engineering, National Central University, Taiwan, Republic of China
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15
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Dobaradaran S, Khorsand M, Hayati A, Moradzadeh R, Pouryousefi M, Ahmadi M. Data on fluoride contents in groundwater of Bushehr province, Iran. Data Brief 2018; 17:1158-1162. [PMID: 29876473 PMCID: PMC5988413 DOI: 10.1016/j.dib.2018.02.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 01/23/2018] [Accepted: 02/08/2018] [Indexed: 12/07/2022] Open
Abstract
In this article, we measured the levels of fluoride in groundwater. The samples were taken from groundwater in Bushehr's province, Iran. After the collection of samples, the concentration levels of fluoride were determined by the standard SPADNS method using spectrometer. The mean concentration levels of fluoride in water of all stations were higher than the WHO drinking water guideline. Microsoft Office Excel 2016 was used for calculation of mean values. The mean concentration level of fluoride instatement were in the range of 1.52 to 3.64 mg l-1.
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Affiliation(s)
- Sina Dobaradaran
- The Persian Gulf Marine Biotechnology Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran.,Systems Environmental Health, Oil, Gas and Energy Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran.,Department of Environmental Health Engineering, Faculty of Health, Bushehr University of Medical Sciences, Bushehr, Iran
| | - Maryam Khorsand
- Department of Environmental Engineering Bushehr branch, Islamic Azad University, Bushehr, Iran
| | - Abdolreza Hayati
- Department of Environmental Engineering Bushehr branch, Islamic Azad University, Bushehr, Iran
| | | | | | - Mostafa Ahmadi
- Urban Water and Wastewater Company, Bushehr Province, Iran
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16
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Moore CS, Caspi A, Woods TN, Chamberlin PC, Dennis BR, Jones AR, Mason JP, Schwartz RA, Tolbert AK. The Instruments and Capabilities of the Miniature X-Ray Solar Spectrometer (MinXSS) CubeSats. Sol Phys 2018; 293:21. [PMID: 31258201 PMCID: PMC6566308 DOI: 10.1007/s11207-018-1243-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 01/05/2018] [Indexed: 06/09/2023]
Abstract
The Miniature X-ray Solar Spectrometer (MinXSS) CubeSat is the first solar science oriented CubeSat mission flown for the NASA Science Mission Directorate, with the main objective of measuring the solar soft X-ray (SXR) flux and a science goal of determining its influence on Earth's ionosphere and thermosphere. These observations can also be used to investigate solar quiescent, active region, and flare properties. The MinXSS X-ray instruments consist of a spectrometer, called X123, with a nominal 0.15 keV full-width at half-maximum (FWHM) resolution at 5.9 keV and a broadband X-ray photometer, called XP. Both instruments are designed to obtain measurements from 0.5 - 30 keV at a nominal time cadence of 10 s. A description of the MinXSS instruments, performance capabilities, and relation to the Geostationary Operational Environmental Satellite (GOES) 0.1 - 0.8 nm flux is given in this article. Early MinXSS results demonstrate the capability of measuring variations of the solar spectral soft X-ray (SXR) flux between 0.8 - 12 keV from at least GOES A5-M5 ( 5 × 10 - 8 - 5 × 10 - 5 W m - 2 ) levels and of inferring physical properties (temperature and emission measure) from the MinXSS data alone. Moreover, coronal elemental abundances can be inferred, specifically for Fe, Ca, Si, Mg, S, Ar, and Ni, when the count rate is sufficiently high at each elemental spectral feature. Additionally, temperature response curves and emission measure loci demonstrate the MinXSS sensitivity to plasma emission at different temperatures. MinXSS observations coupled with those from other solar observatories can help address some of the most compelling questions in solar coronal physics. Finally, simultaneous observations by MinXSS and the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) can provide the most spectrally complete soft X-ray solar flare photon flux measurements to date.
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Affiliation(s)
- Christopher S. Moore
- Department for Astrophysical and Planetary Science, University of Colorado, Boulder, CO USA
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO USA
- Present Address: Harvard-Smithsonian Center for Astrophysics, Cambridge, MA USA
| | - Amir Caspi
- Southwest Research Institute, Boulder, CO USA
| | - Thomas N. Woods
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO USA
| | - Phillip C. Chamberlin
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO USA
- NASA Goddard Space Flight Center, Code 671.0, Greenbelt, MD USA
| | - Brian R. Dennis
- NASA Goddard Space Flight Center, Code 671.0, Greenbelt, MD USA
| | - Andrew R. Jones
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO USA
| | - James P. Mason
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO USA
- NASA Goddard Space Flight Center, Code 671.0, Greenbelt, MD USA
| | - Richard A. Schwartz
- NASA Goddard Space Flight Center, Code 671.0, Greenbelt, MD USA
- American University, Washington, DC USA
| | - Anne K. Tolbert
- NASA Goddard Space Flight Center, Code 671.0, Greenbelt, MD USA
- American University, Washington, DC USA
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17
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Gracanin V, Guatelli S, Prokopovich D, Rosenfeld AB, Berry A. Development of a Geant4 application to characterise a prototype neutron detector based on three orthogonal 3He tubes inside an HDPE sphere. Phys Med 2017; 33:189-196. [PMID: 28057428 DOI: 10.1016/j.ejmp.2016.12.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 12/20/2016] [Accepted: 12/22/2016] [Indexed: 11/17/2022] Open
Abstract
The Bonner Sphere Spectrometer (BSS) system is a well-established technique for neutron dosimetry that involves detection of thermal neutrons within a range of hydrogenous moderators. BSS detectors are often used to perform neutron field surveys in order to determine the ambient dose equivalent H*(10) and estimate health risk to personnel. There is a potential limitation of existing neutron survey techniques, since some detectors do not consider the direction of the neutron field, which can result in overly conservative estimates of dose in neutron fields. This paper shows the development of a Geant4 simulation application to characterise a prototype neutron detector based on three orthogonal 3He tubes inside a single HDPE sphere built at the Australian Nuclear Science and Technology Organisation (ANSTO). The Geant4 simulation has been validated with respect to experimental measurements performed with an Am-Be source.
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Affiliation(s)
- V Gracanin
- Centre of Medical and Radiation Physics, University of Wollongong, NSW, Australia.
| | - S Guatelli
- Centre of Medical and Radiation Physics, University of Wollongong, NSW, Australia
| | - D Prokopovich
- Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW, Australia
| | - A B Rosenfeld
- Centre of Medical and Radiation Physics, University of Wollongong, NSW, Australia
| | - A Berry
- Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW, Australia
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Abstract
According to the protein-only hypothesis of prion propagation, the pathogenesis of prion disease is due to the misfolding of cellular PrP (PrPC) which gives rise to disease-associated PrPSc. This misfolding results in the predominantly α-helix secondary structure of PrP becoming increasingly β-sheet. Prion protein researchers often employ circular dichroism (CD) spectroscopy to rapidly analyze and identify the degree of α-helix and β-sheet content in their recombinant protein and peptide samples. CD is a nondestructive method of determining protein secondary structure and can be used to monitor the protein structural changes in various environments, e.g., pH and temperature. CD can also be used to investigate kinetic and thermodynamic characteristics of proteins and peptides.
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Affiliation(s)
- Laura J Ellett
- Department of Pathology, The University of Melbourne, Parkville, Melbourne, VIC, 3010, Australia
| | - Vanessa A Johanssen
- Department of Medicine, The University of Melbourne, Parkville, Melbourne, VIC, 3010, Australia.
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Cuadrado A, López-Alonso JM, González FJ, Alda J. Spectral Response of Metallic Optical Antennas Driven by Temperature. Plasmonics 2016; 12:553-561. [PMID: 28539850 PMCID: PMC5420004 DOI: 10.1007/s11468-016-0297-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 06/05/2016] [Indexed: 06/07/2023]
Abstract
When optical antennas are used as light detectors, temperature changes their spectral response. Using this relation, we determine the spectrum of a light beam from an optical antenna's signal. A numerical evaluation of the temperature-spectral response has been completed with a model for the noise of the device. Using both the response and the noise model, we have established the capabilities of the device by quantifying the error in the spectrum determination both for broadband spectrum and monochromatic radiation.
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Affiliation(s)
- Alexander Cuadrado
- Laser Processing Group.Insitute of Optics. Consejo Superior de Investigaciones Científicas, C/ Serrano 121, 28006 Madrid, Spain
| | - José Manuel López-Alonso
- Applied Optics Complutense Group, University Complutense of Madrid, C/ Arcos de Jalón, 118, 28037 Madrid, Spain
| | - Francisco Javier González
- Coordinación para la Innovación y Aplicación de la Ciencia y la Tecnología, Universidad Autónoma de San Luis Potosí, Sierra Leona, 550, Lomas 2a Seccion, CIACYT Building, 78210 San Luis Potosí, SLP México
| | - Javier Alda
- Applied Optics Complutense Group, University Complutense of Madrid, C/ Arcos de Jalón, 118, 28037 Madrid, Spain
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20
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Rasmussen TP. Compact and High Performance Spectrometers based on Novel Transmission Gratings with High Dispersion. Appl Spectrosc 2016; 70:804-809. [PMID: 27002126 DOI: 10.1177/0003702816638271] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 12/13/2015] [Indexed: 06/05/2023]
Abstract
In this article we outline how ultra-compact, yet high performance spectrometers can be designed and built with highly dispersive transmission gratings. By using fused silica as the grating material, and by careful design of the detailed grating structure, we demonstrate an ultraviolet spectrometer with a high and nearly flat efficiency from 178 to 409 nm, a resolution of 0.2 nm, and dimensions of only 61 mm × 64 mm × 19 mm. We tested this spectrometer in a laser-induced breakdown spectroscopy experiment and showed that the spectral information gathered with the spectrometer can be used to obtain quantitative results for sulfur.
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21
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Pügner T, Knobbe J, Grüger H. Near-Infrared Grating Spectrometer for Mobile Phone Applications. Appl Spectrosc 2016; 70:734-45. [PMID: 27170776 PMCID: PMC4871177 DOI: 10.1177/0003702816638277] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 01/20/2016] [Indexed: 05/08/2023]
Abstract
Near-infrared (NIR) spectroscopy is a well-established technique for the chemical analysis of organic and inorganic matter. Accordingly, spectroscopic instrumentation of different complexity has been developed and is currently commercially available. However, there are an increasing number of new mobile applications that have come into focus and that cannot be addressed by the existing technology due to size and cost. Therefore, a new miniaturized scanning grating spectrometer for NIR spectroscopy has been developed at Fraunhofer IPMS. It is based on micro-electro-mechanical systems (MEMS) technology, and has been designed to meet the requirements for mobile application, regarding spectral range, resolution, overall size, robustness, and cost. The MEMS spectrometer covers a spectral range from 950 nm to 1900 nm at a resolution of 10 nm. The instrument is extremely small and has a volume of only 2.1 cm(3) Therefore, it is well suited for integration, even into a mobile phone. A first sample of the new spectrometer has been manufactured and put into operation. The results of a series of test measurements are in good agreement with the requirements and specifications.
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Affiliation(s)
- Tino Pügner
- Fraunhofer Institute for Photonic Microsystems, Dresden, Germany
| | - Jens Knobbe
- Fraunhofer Institute for Photonic Microsystems, Dresden, Germany
| | - Heinrich Grüger
- Fraunhofer Institute for Photonic Microsystems, Dresden, Germany
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22
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Protopopov V. Automatic Gain Control in Compact Spectrometers. Appl Spectrosc 2016; 70:539-542. [PMID: 26810181 DOI: 10.1177/0003702815626683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 07/15/2015] [Indexed: 06/05/2023]
Abstract
An image intensifier installed in the optical path of a compact spectrometer may act not only as a fast gating unit, which is widely used for time-resolved measurements, but also as a variable attenuator-amplifier in a continuous wave mode. This opens the possibility of an automatic gain control, a new feature in spectroscopy. With it, the user is relieved from the necessity to manually adjust signal level at a certain value that it is done automatically by means of an electronic feedback loop. It is even more important that automatic gain control is done without changing exposure time, which is an additional benefit in time-resolved experiments. The concept, algorithm, design considerations, and experimental results are presented.
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Fatima N. Influence of extended light exposure curing times on the degree of conversion of resin-based pit and fissure sealant materials. Saudi Dent J 2014; 26:151-5. [PMID: 25382947 DOI: 10.1016/j.sdentj.2014.05.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 02/20/2014] [Accepted: 05/06/2014] [Indexed: 11/21/2022] Open
Abstract
PURPOSE The aim of present study was to evaluate extended curing times on the degree of conversion (DC) of filled and unfilled resin-based materials used as pit and fissure sealants. MATERIALS AND METHODS The materials examined were a flowable composite (Filtek™ Z350 XT Flowable) and a pit and fissure sealant (Clinpro™ Sealant). Thirty disks of each material were prepared. The 30 made of the flowable composite were divided into three groups (n = 10 each) according to the three different curing times studied: 20 s (group 1), 40 s (group 2), and 60 s (group 3). Similarly, the 30 disks made of the pit and fissure sealant were divided into three groups (n = 10 each) according to the three different curing times: 20 s (group 4), 40 s (group 5), and 60 s (group 6). After polymerization, the disks were removed from the mold and stored in dry, lightproof containers in an incubator at 37 °C for 24 h. The DC was obtained using an Avatar 320 FTIR spectrometer. Then the data were analyzed using the Kruskal-Wallis test and the Fisher's least significant difference post hoc test for multiple comparisons (alpha = 0.05). RESULTS DC values for the flowable composite (Filtek™ Z350 XT) were higher (p = 0.002) than those for the pit and fissure sealant (Clinpro™ Sealant). Group 2 and group 5 showed significantly higher DC values than group 1 and group 4, respectively. There was no difference between groups 2 and 3 or between groups 5 and 6 (p = 2.93). CONCLUSION An extended curing time improves the DC to some extent for both materials.
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Emery SB, Conradi MS. Piezoelectric crystals generate NMR-like signals for rapid spectrometer troubleshooting. J Magn Reson 2014; 242:1-3. [PMID: 24583516 DOI: 10.1016/j.jmr.2014.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 02/06/2014] [Accepted: 02/07/2014] [Indexed: 06/03/2023]
Abstract
Use of frequency-control quartz crystals for the generation of NMR-like signals via the piezoelectric effect is discussed. Such crystals are inexpensive and cover a wide range of RF frequencies. The crystal is connected to the spectrometer through a 30dB attenuator. Excitation by single, short RF pulses results in time domain signals similar to NMR FIDs. We show that the crystal should be shunted by a low resistance for largest Q (longest T2). By using odd higher overtones, the crystals were made to resonate at the high operating frequencies typical of modern spectrometers, here up to 630MHz. The performance of precision manufactured crystals is particularly better at high frequencies, compared to mass production crystals. The abundant and stable signal provided by the piezoelectric crystals yields a simple method for troubleshooting and testing NMR spectrometers.
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Affiliation(s)
- Samuel B Emery
- Department of Physics, Washington University, Compton Hall, Campus Box 1105, One Brookings Drive, Saint Louis, MO 63130, USA.
| | - Mark S Conradi
- Department of Physics, Washington University, Compton Hall, Campus Box 1105, One Brookings Drive, Saint Louis, MO 63130, USA.
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Wei W, Huang S, Wang N, Jin Z, Zhang J, Chen W. A near-infrared spectrometer based on novel grating light modulators. Sensors (Basel) 2009; 9:3109-21. [PMID: 22574065 DOI: 10.3390/s90403109] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Revised: 04/09/2009] [Accepted: 04/20/2009] [Indexed: 11/17/2022]
Abstract
A near-infrared spectrometer based on novel MOEMS grating light modulators is proposed. The spectrum detection method that combines a grating light modulator array with a single near-infrared detector has been applied. Firstly, optics theory has been used to analyze the essential principles of the proposed spectroscopic sensor. Secondly, the grating light modulators have been designed and fabricated by micro-machining technology. Finally, the principles of this spectroscopic sensor have been validated and its key parameters have been tested by experiments. The result shows that the spectral resolution is better than 10 nm, the wavelength deviation is less than 1 nm, the deviation of the intensity of peak wavelength is no more than 0.5%, the driving voltage of grating light modulators array device is below 25 V and the response frequency of it is about 5 kHz. With low cost, satisfactory precision, portability and other advantages, the spectrometer should find potential applications in food safety and quality monitoring, pharmaceutical identification and agriculture product quality classification.
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