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Potential Application of Three Laser-Based Bacteria Detection Techniques to The Meat Processing Plants - A Review 三种激光细菌检测技术在肉类加工厂的潜在应用综述
Laser Applications to Chemical Analysis Pub Date : 1900-01-01 DOI: 10.1364/laca.1994.wd.10
N. Chou, Yud-Ren Chen
{"title":"Potential Application of Three Laser-Based Bacteria Detection Techniques to The Meat Processing Plants - A Review","authors":"N. Chou, Yud-Ren Chen","doi":"10.1364/laca.1994.wd.10","DOIUrl":"https://doi.org/10.1364/laca.1994.wd.10","url":null,"abstract":"This review was prompted by the concerns of the recent serious incidence of bacterial contamination, especially in raw or partially cooked meat. There are 4 million cases of food poisoning reported annually, most of them are caused by bacteria. Recent GAO testimony on food safety stated that the meat inspection system has changed little since it was first instituted in 1906 and is not capable of addressing today's concerns about microbial contamination (1).","PeriodicalId":252738,"journal":{"name":"Laser Applications to Chemical Analysis","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129231502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Optical Diagnostics of Single Liquid Droplets 单液滴光学诊断
Laser Applications to Chemical Analysis Pub Date : 1900-01-01 DOI: 10.1364/laca.1994.wa.1
M. Winter
{"title":"Optical Diagnostics of Single Liquid Droplets","authors":"M. Winter","doi":"10.1364/laca.1994.wa.1","DOIUrl":"https://doi.org/10.1364/laca.1994.wa.1","url":null,"abstract":"Most propulsion and energy utilization devices rely on the spraying of liquid-phase fuel or oxidizer, into an energy conversion chamber. The behavior of individual droplets in a spray combustor is a critical part of the combustion process, and currently we can only speculate about several fundamental aspects related to droplet heat-up and evaporation. A series of laser diagnostic techniques has been developed to measure heat and mass transfer associated with individual droplets characteristic of a spray. One such technique provides images of flow patterns along a meridian slice of small droplets using Laser-Induced Fluorescence (LIF), illustrating the presence of internal circulation. Extremely accurate vaporization rate measurements are being performed by using individual droplets as miniature lasers, producing Morphology–Dependant Resonances (MDR). MDR output mode-structure (primarily wavelength) contains information about the laser cavity dimensions and is related to droplet size. Another set of measurements is aimed at studying gas-phase-flow/flame front interactions in a microgravity environment using both planar laser–induced fluorescence and Partical Image Velocimetry, (PIV). By developing new ways of probing individual droplets, an understanding of the fundamental physics governing their behavior may be gained.","PeriodicalId":252738,"journal":{"name":"Laser Applications to Chemical Analysis","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124129715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Spatially and Temporally Resolved Electron Number Densities in a Decaying Laser-Induced Hydrogen Plasma 激光诱导氢等离子体衰变中空间和时间分辨电子数密度
Laser Applications to Chemical Analysis Pub Date : 1900-01-01 DOI: 10.1364/laca.1994.tub.3
C. Parigger, D. Plemmons, J. Lewis
{"title":"Spatially and Temporally Resolved Electron Number Densities in a Decaying Laser-Induced Hydrogen Plasma","authors":"C. Parigger, D. Plemmons, J. Lewis","doi":"10.1364/laca.1994.tub.3","DOIUrl":"https://doi.org/10.1364/laca.1994.tub.3","url":null,"abstract":"Measurements of the widths of Stark broadened hydrogen Balmer Series lines can be used to infer electron number densities of optically created plasmas. A typical optical breakdown plasma is transient and shows spatial structure. For example, self-focusing effects may induce density variations which may be measured using diffraction techniques.1 The expanding plasma induces number density variations that in fact may form a light pipe for high intensity laser pulses.2","PeriodicalId":252738,"journal":{"name":"Laser Applications to Chemical Analysis","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124226039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Laser-Induced Fluorescence and Laser-Induced Photo-Dissociation in Two-Step Graphite Furnace 两步石墨炉中激光诱导荧光和激光诱导光解离
Laser Applications to Chemical Analysis Pub Date : 1900-01-01 DOI: 10.1364/laca.1990.tua6
S. Sjöström, M. Norberg
{"title":"Laser-Induced Fluorescence and Laser-Induced Photo-Dissociation in Two-Step Graphite Furnace","authors":"S. Sjöström, M. Norberg","doi":"10.1364/laca.1990.tua6","DOIUrl":"https://doi.org/10.1364/laca.1990.tua6","url":null,"abstract":"Laser-Induced Fluorescence (LIF) Spectroscopy performed in an electrothermal atomizer has shown to be an extremely sensitive and selective method for detecting traces in solid, liquid and gaseous samples with detection limits in the femtogram region reported.1-4","PeriodicalId":252738,"journal":{"name":"Laser Applications to Chemical Analysis","volume":"120 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134015064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Single-Molecule Detection in Microdroplets 微液滴中的单分子检测
Laser Applications to Chemical Analysis Pub Date : 1900-01-01 DOI: 10.1364/laca.1994.thd.1
M. Barnes, W. Whitten, J. Ramsey
{"title":"Single-Molecule Detection in Microdroplets","authors":"M. Barnes, W. Whitten, J. Ramsey","doi":"10.1364/laca.1994.thd.1","DOIUrl":"https://doi.org/10.1364/laca.1994.thd.1","url":null,"abstract":"Detection of single molecules in condensed phase with high signal-to-noise ratios is important for applications which involve detection of fluorescent tags such as DNA sequencing1, fluorescence immunoassay2, or hydrology.3 In addition, observation of photophysical phenomena unique to the interaction of a radiation field with an isolatedmolecule, such as photon antibunching,4 depends upon having such high sensitivity. As demonstrated by the experiments of Moerner5 and Orrit,6 very high sensitivity at the single molecule level can be achieved by probing \"guest\" molecules in solid hosts at cryogenic temperatures. However, practical applications requiring single molecule detection usually require measurements on liquid phase solutions at room temperature. These demands pose new problems such as solvent dependent quantum yield, finite photochemical lifetime (the number of absorption-emission cycles which occur before irreversible bleaching of fluorescence), and solvent Raman scattering and fluorescence.","PeriodicalId":252738,"journal":{"name":"Laser Applications to Chemical Analysis","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134180960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Structure and Extended Electronic States in Molecular Assemblies of Hemicyanine Amphiphiles 半花青碱类两亲分子组合体的结构和扩展电子态
Laser Applications to Chemical Analysis Pub Date : 1900-01-01 DOI: 10.1364/laca.1994.wa.4
Q. Song, Z. Xu, W. Lu, P. Bohn, GJ. Blanchard
{"title":"Structure and Extended Electronic States in Molecular Assemblies of Hemicyanine Amphiphiles","authors":"Q. Song, Z. Xu, W. Lu, P. Bohn, GJ. Blanchard","doi":"10.1364/laca.1994.wa.4","DOIUrl":"https://doi.org/10.1364/laca.1994.wa.4","url":null,"abstract":"Hemicyanine dyes containing long alkyl chains have attracted considerable attention in recent years due to their significance as possible optoelectronic and molecular electronic materials. With large non-linear molecular polarizabilities, amphiphilic hemicyanines are readily incorporated into Langmuir-Bludgett monolayer and multilayer films, forming artificial molecular assemblies with preferred spatial and orientational order [1,2], In contrast to centrosymmetric bulk materials, in which the individual effects are canceled, and the overall bulk second-order susceptibility vanishes [1], highly aligned structures ensure non-zero macroscopic second-order susceptibilities, χ(2). In addition molecular assemblies of these materials have been shown to be characterized by extended electronic states in which the relationship between molecular structure and delocalization of the electronic states is a matter of current interest.","PeriodicalId":252738,"journal":{"name":"Laser Applications to Chemical Analysis","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131737940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Computer-Replicated Spectrograms By Ensemble Averaging and Normalization 用集合平均和归一化的计算机复制谱图
Laser Applications to Chemical Analysis Pub Date : 1900-01-01 DOI: 10.1364/laca.1992.pd12
M. Edwards
{"title":"Computer-Replicated Spectrograms By Ensemble Averaging and Normalization","authors":"M. Edwards","doi":"10.1364/laca.1992.pd12","DOIUrl":"https://doi.org/10.1364/laca.1992.pd12","url":null,"abstract":"High resolution absorption bands, as produced by a tunable diode laser, are superimposed on a background that reflects both the variation of the laser-output power with frequency and the specificity of the spectrometer used to filter out unwanted cavity modes. Gross distortions of the absorption bands from these combined effects make the extraction of characteristic line data extremely tedious or error prone. To address these features, I measured high resolution infrared spectra in the 8.7 microns region using a tunable diode lasers spectrometer where the latter is interfaced -using the Labwindows' MC-MIO-16 interface board - to the IBM Model 70 PS/2 computer. The replicated computer enhanced spectrograms are free of random fluctuation noises that typifies analog chart recorder outputs. The production of the computer-replicated spectrograms occurs from a software program called the \"horter.” I have addressed the problem of normalization of the spectrograms, using a second computer program. The overall outcome is a computer- replicated spectrogram having reduced spectra band distortions. These two improvements have implications for increasing the measurable of the line parameters, halfwidths, pressure broadening coefficients, and the line intensities. Measurements have been made for such gases as N2O, and SO2.","PeriodicalId":252738,"journal":{"name":"Laser Applications to Chemical Analysis","volume":"165 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133382618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Species Identification and Conversion Measurements in a Carbon Tetrachloride Radio Frequency Plasma Using Coherent Raman Techniques 使用相干拉曼技术在四氯化碳射频等离子体中进行物种识别和转换测量
Laser Applications to Chemical Analysis Pub Date : 1900-01-01 DOI: 10.1364/laca.1994.wd.7
R. Rodriguez, F. V. Wells
{"title":"Species Identification and Conversion Measurements in a Carbon Tetrachloride Radio Frequency Plasma Using Coherent Raman Techniques","authors":"R. Rodriguez, F. V. Wells","doi":"10.1364/laca.1994.wd.7","DOIUrl":"https://doi.org/10.1364/laca.1994.wd.7","url":null,"abstract":"Radio frequency plasmas are used in the electronics industry in various phases of microcircuitry processing. Deposition and etching are two key areas where these types of plasmas are used. In recent past, carbon tetrachloride, CC14, has been used in the etching of metals such as aluminum. However, one of the problems associated with using this gas as an etchant is the formation of a glow polymer which coats the walls of the chamber and can interfere with the etching.","PeriodicalId":252738,"journal":{"name":"Laser Applications to Chemical Analysis","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132178533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Silicon Processing Chemical Diagnostics and Control Using Diode Lasers 使用二极管激光器的硅加工化学诊断和控制
Laser Applications to Chemical Analysis Pub Date : 1900-01-01 DOI: 10.1364/laca.1994.tub.10
E. Whittaker, H. C. Sun, C. K. Ng, B. Singh, V. Patel
{"title":"Silicon Processing Chemical Diagnostics and Control Using Diode Lasers","authors":"E. Whittaker, H. C. Sun, C. K. Ng, B. Singh, V. Patel","doi":"10.1364/laca.1994.tub.10","DOIUrl":"https://doi.org/10.1364/laca.1994.tub.10","url":null,"abstract":"Infra-red diode laser absorption spectroscopy has long been a powerful tool for molecular spectroscopists and analytic chemists. Through recent improvements in lead salt laser fabrication lasers with modest power (up to several milliwatts), good beam quality and broad tunability (as much as 30% of center frequency) are now available. In addition, very low absorbence species detection, free of window induced interference fringes is now possible by utilizing a combination of frequency and wavelength modulation via the diode laser injection current.1 This modulation approach also lends itself to a simple feedback method that may be used to lock the laser frequency to a particular molecular absorption line and thus enable real time measurements of that species' absorbence in the presence of high levels of electrical background noise often found in industrial settings.2","PeriodicalId":252738,"journal":{"name":"Laser Applications to Chemical Analysis","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116863410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Unimolecular Photochemistry Studied by Photodissociation-Photoionization Mass Spectrometry 光解-光电离质谱法研究单分子光化学
Laser Applications to Chemical Analysis Pub Date : 1900-01-01 DOI: 10.1364/laca.1994.tub.8
M. Johnston, P. Ross, S. V. Van Bramer, E.D. Leavitt
{"title":"Unimolecular Photochemistry Studied by Photodissociation-Photoionization Mass Spectrometry","authors":"M. Johnston, P. Ross, S. V. Van Bramer, E.D. Leavitt","doi":"10.1364/laca.1994.tub.8","DOIUrl":"https://doi.org/10.1364/laca.1994.tub.8","url":null,"abstract":"Photochemical reactions are commonly studied in the condensed phase or in a high pressure gas. The primary photodissociation products are inferred from distributions of stable compounds produced by secondary reactions. As these investigations are extended to molecules of increasing size and complexity, identification of the primary products becomes difficult owing to the large number of possible secondary reactions. In photodissociation-photoionization mass spectrometry (PDPI-MS), molecular photodissociation is performed at low pressure in the source region of a mass spectrometer. After a short time delay, the neutral photodissociation products are softly ionized with coherent vacuum ultraviolet radiation and mass analyzed. Unlike photochemical experiments at high pressure, PDPI permits direct observation of the entire product distribution on the microsecond timescale.","PeriodicalId":252738,"journal":{"name":"Laser Applications to Chemical Analysis","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117315000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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