During photosynthesis, sunlight is efficiently captured by light-harvesting complexes, and the excitation energy is then funneled towards the reaction centre. These photosynthetic excitation energy transfer (EET) pathways are complex and proceed in a multistep fashion. Ultrafast two-dimensional electronic spectroscopy (2DES) is an important tool to study EET processes in photosynthetic complexes. However, the multistep EET processes can only be indirectly inferred by correlating different cross peaks from a series of 2DES spectra. Here we directly observe multistep EET processes in LHCII using ultrafast fifth-order three-dimensional electronic spectroscopy (3DES). We measure cross peaks in 3DES spectra of LHCII that directly indicate energy transfer from excitons in the chlorophyll b (Chl b) manifold to the low-energy level chlorophyll a (Chl a) via mid-level Chl a energy states. This new spectroscopic technique allows scientists to move a step towards mapping the complete complex EET processes ...
The study of the photosynthetic processes has always had a particular relevance in spectroscopy because of its possible applications in light harvesting and energy storage. Since the light-harvesting pigment-protein complexes have this functional role in nature, many of studies have been focused on understanding photophysical processes occurring in these systems. Our work aims to study the spectroscopic properties of the best known pigment involved in the photosynthesis, Chlorophyll a, and their changes with different solvents. The study of the pigment was conducted by linear spectroscopic studies for water-solvent mixtures, while by the nonlinear technique 2D spectroscopy was applied for pure solvent. The theory and technique of 2D spectroscopy is described. The properties of solvents strongly influence the environment felt by the molecule and its capability of aggregate formation. The solvent properties that were found to be most relevant for our study were viscosity, H-bonding formation and ...
The |i|Journal of Biomedical Optics|/i| (JBO) publishes peer-reviewed papers on the use of novel optical systems and techniques for improved health care and biomedical research.
Apoptosis, ldquoprogrammed cell death,rdquo is a cellular process exhibiting distinct biochemical and morphological changes. There is much interest regardi
TY - JOUR. T1 - Electronic spectroscopy of intermediates involved in the conversion of methane to methanol by FeO+. AU - Aguirre, Fernando. AU - Husband, John. AU - Thompson, Christopher J.. AU - Stringer, Kay L.. AU - Metz, Ricardo B.. PY - 2002/3/8. Y1 - 2002/3/8. N2 - The reaction intermediates [H2C=Fe-OH2]+ and [HO-Fe-CH3]+ by photodissociation were studied. On the basis of experimental results and calculations performed at the B3LYP and TD3LYP level, excited state vibrational frequencies as well as geometry changes upon photoexcitation in [H2C=Fe-OH2]+ and [HO-Fe-CH3]+ were determined.. AB - The reaction intermediates [H2C=Fe-OH2]+ and [HO-Fe-CH3]+ by photodissociation were studied. On the basis of experimental results and calculations performed at the B3LYP and TD3LYP level, excited state vibrational frequencies as well as geometry changes upon photoexcitation in [H2C=Fe-OH2]+ and [HO-Fe-CH3]+ were determined.. UR - ...
Fleming has compared 2-D electronic spectroscopy to the technique used in the early super-heterodyne radios, where an incoming high frequency radio signal was converted by an oscillator to a lower frequency for more controllable amplification and better reception. In the case of 2-D electronic spectroscopy, scientists can track the transfer of energy between molecules that are coupled (connected) through their electronic and vibrational states in any photoactive system, macromolecular assembly or nanostructure.. Fleming and his group first described 2-D electronic spectroscopy in a 2005 Nature paper, when they used the technique to observe electronic couplings in the Fenna-Matthews-Olson (FMO) photosynthetic light-harvesting protein, a molecular complex in green sulphur bacteria. Said Engel, "The 2005 paper was the first biological application of this technique, now we have used 2-D electronic spectroscopy to discover a new phenomenon in photosynthetic systems. While the possibility that ...
CiteSeerX - Scientific articles matching the query: A Novel Analysis Dictionary Learning Model Based Hyperspectral Image Classification Method
Hyperspectral imaging is emerging as a promising approach for plant disease identification. The large and possibly redundant information contained in hyperspectral data cubes makes deep learning based identification of plant diseases a natural fit. Here, we deploy a novel 3D deep convolutional neural network (DCNN) that directly assimilates the hyperspectral data. Furthermore, we interrogate the learnt model to produce physiologically meaningful explanations. We focus on an economically important disease, charcoal rot, which is a soil borne fungal disease that affects the yield of soybean crops worldwide. Based on hyperspectral imaging of inoculated and mock-inoculated stem images, our 3D DCNN has a classification accuracy of 95.73% and an infected class F1 score of 0.87. Using the concept of a saliency map, we visualize the most sensitive pixel locations, and show that the spatial regions with visible disease symptoms are overwhelmingly chosen by the model for classification. We also find that the most
The non-resonant dynamic Stark effect is a powerful and general way of manipulating ultrafast processes in atoms, molecules, and solids with exquisite precision. We discuss the physics behind this effect, and demonstrate its efficacy as a method of control in a variety of systems. These applications range fr Coherence and Control in Chemistry
We measure several fundamental electronic properties of molecules such as charge transfer and electronic delocalization using a technique known as Stark spectroscopy. Stark spectroscopy involves applying large electric fields to molecules in films or matrices and analyzing the effects of the field perturbation on the absorption or emission spectrum. We have recently focused on the properties of MEH-PPV and other molecules used to make to organic light emitting diodes (OLEDs). Stark spectroscopy reveals the mechanism by which a large applied electric field, such as those present in OLEDs, produces undesirable emission quenching and suggests strategies for minimizing this loss of device efficiency through modifications of the polymer structure.. Emission properties of Single Molecules and Aggregates. Recent years has seen a huge growth in the use of organic conjugated oligomers and polymers in the design of light emitting diodes (OLEDs) and photovoltaic cells. When these molecules are placed in ...
Application Note: Kinetics of Photocatalysis Reactions Studied by Transient Absorption Spectroscopy. Read and Download our Application Note.
1. Physical principles of optical spectroscopy and ellipsometry - Electron transitions and the origin of the spectral dependences of the optical parameters - Modeling of dielectric function of materials - Kramers-Kronig dispersion relation, the relation of absorption and dispersion - Spectral device (dispersive prism, grating, Fabry-Perot interferometer) - Selected parts of optical thin films - Methods of effective environments and their use in optical spectroscopy 2. REFLECTION AND TRANSMISSION spectroscopy in the visible, near-ultraviolet A near-infrared - Components of spectrometers, the two-spectrometer - Materials used in optical spectroscopy - Resolution limit and instrumentation functions monochromator - Superstructure instruments for measuring reflection spectra, integrating sphere 3. Spectroscopic ellipsometry - Methods of ellipsometry, the ellipsometric measurement angles psi and delta, generalized ellipsometry - Type ellipsometer (zero ellipsometry, polarization modulation, rotating ...
There are loads of situations when spectrum analysis can be helpful during mixdown, but there are a few things to bear in mind if you want to take full advantage of it. The first thing is that the analysers bundled with most DAW systems arent high-resolution enough, so check out some of the much better third-party options. Voxengos SPAN is a good piece of cross-platform freeware, for example, although I tend to use Schwas affordable payware Schope myself.. The first big analysis application at mixdown highlights overall mix-tonality imbalances that your monitoring hasnt alerted you to. Although this is clearly relevant to budget setups with budget monitors and uncontrolled acoustics, even pros like Joe Chiccarelli and Eric Rosse talk about using spectrum analysis in this way. However, every spectrum analyser seems to display things in a different way, so you need to get to know how your favourite records look on screen before you can come to any meaningful conclusions about your own work. A ...
The spectrum pane is similar to the one you can see in Chanalyzer, a spectrum analysis application by MetaGeek that comes with Wi-Spy. By default, the Channels and Spectrum pane displays one or two planar spectrum graphs for single- and dual-band Wi-Spy models, respectively. The appearance of the graphs can be controlled via the context menu. Select 2.4 GHz, 5.0 GHz, or Dual to have the spectrum pane display one of the single frequency bands or two bands simultaneously (5.0 GHz and Dual are available only if you have a dual-band Wi-Spy model.) Select Current Level to display a line that shows the current signal amplitude; select Max Level to display a line that shows the maximum signal amplitude. The X-axis item allows you to select the measurement units of the horizontal axis; you can choose between Frequency in MHz and Channel numbers. By enabling the Waterfall view, you can have the application graph amplitude over time. Select 1/3, 1/2, or 2/3 of the window size to adjust the area of the ...
but the nature of this approximation is typically determined by characteristics of audio perception. Best results are usually obtained by formulating this as an FIR filter design problem (see Chapter 4). In general, both time-domain and frequency-domain specifications are needed. (Recall the potentially problematic impulses in the Dolph-Chebyshev window shown in Fig.3.33 when its length was long and ripple level was high). Equivalently, both magnitude and phase specifications are necessary in the frequency domain. A window transform can generally be regarded as the frequency response of a lowpass filter having a stop band corresponding to the side lobes and a pass band corresponding to the main lobe (or central section of the main lobe). Optimal lowpass filters require a transition region from the pass band to the stop band. For spectrum analysis windows, it is natural to define the entire main lobe as ``transition region. That is, the pass-band width is zero. Alternatively, the pass-band ...
I need to measure frequency of a low level signal in the range 300kHz to 500kHz with the frquency either displayed numerically or available to process in an automated PC test setup to give a pass/fail result. Currently I use an expensive hardware spectrum analyser with a human interpreter. The spectrum analysis software available for the picoscopes looks very basic and appears to always run from zero up to the maximum selected frequency. Question 1: can the frequency axis be displayed with user selectable start and stop frequencies like a normal hardware analyser? Question 2: Are there marker peak-find functions available with live readout or data-out that can be used in PC ATE ...
This thesis presents the non-invasive use of diffuse reflectance spectroscopy (DRS) to provide information about the biochemical composition of living tissue. During DRS measurements, the incident, visible light is partially absorbed by chromophores but also scattered in the tissue before being remitted.. Human skin and heart, the main tissue objects in this thesis, are dependent on a sufficient inflow of oxygenized blood, and outflow of metabolic byproducts. This process could be monitored by DRS using the spectral fingerprints of the most important tissue chromophores, oxyhemoglobin and deoxyhemoglobin.. The Beer-Lambert law was used to produce models for the DRS and has thus been a foundation for the analyses throughout this work. Decomposition into the different chromophores was performed using least square fitting and tabulated data for chromophore absorptivity.. These techniques were used to study skin tissue erythema induced by a provocation of an applied heat load on EMLA-treated skin. ...
I tried using a Sound Blaster Z PCIe card in conjunction with spectrum analysis software but the results were dissapointing. The SB Z appears to add a fair amount of distortion (mainly second harmonic) to signals feeding the line input. I then tried an old SB Audigy 2 PCI card in another PC. The results were much better. Does anyone know why this should be? My own theory is that the SB Z shares a single input jack for line input and mic input. That must mean there is some variable gain
Mohammadi, SM, Enshaeifar, S, Ghavami, M and Sanei, S (2015) Classification of Awake, REM, and NREM from EEG via Singular Spectrum Analysis In: 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2015-08-25 - 2015-08-29, Milan, ITALY. Full text not available from this repository ...
A method and device for detecting dichroic and/or birefringent narrow spectral features in a sample is described. The method includes the steps of providing a beam of light having an optical frequency bandwidth which is narrow compared to the width of the narrow spectral feature and having a center frequency ωc which lies near the narrow spectral feature, polarization phase modulating a beam of light with a single RF frequency to provide a pure FM spectrum having upper and lower sidebands in which either the carrier and sidebands have been polarized with respect to one another, exposing the sample containing the narrow spectral feature to the polarized modulated light so that the FM sidebands probe the narrow spectral feature, polarization analyzing and then photodetecting the light emerging from the sample to detect a RF beat at the specific RF frequency used for the polarization phase modulation, and electronically monitoring the amplitude of the RF beat signal to indicate the strength of the narrow
If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library, or send a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. ...
Matteoli, S., E.J. Ientilucci, J.P. Kerekes. "Operational and performance considerations of radiative transfer modeling in hyperspectral target detection." IEEE Transactions on Geoscience and Remote Sensing, (2010): 1-13. Print. £. Stefanou, M.S., J.P. Kerekes. "Image-Derived Prediction of Spectral Image Utility for Target Detection Applications." IEEE Transactions on Geoscience and Remote Sensing, 48.5 (2010): 1827-1833. Print. † £. King, K.C., J.P. Kerekes. "Development of a Web-based Blind Test to Score and Rank Hyperspectral Classification Algorithms." Proceedings of the 2010 Western NY Image Processing Workshop, IEEE, Nov. 2010. n.p. Print. † £. Lu, Z., A.C. Rice, J.R. Vasquez, J.P. Kerekes. "Target Discrimination Via Optimal Wavelength Band Selection With Synthetic Hyperspectral Imagery." Proceedings of the Second Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing, IEEE, June 2010. n.p. Print. £. Presnar, M.D., J.P. Kerekes, D.R. Pogorzala. "Dynamic ...
We explore the use of Monte-Carlo-model-based methods for the analysis of fluorescence and diffuse reflectance spectra measured from breast cells. the difference in model selection by individual researchers, and this was the only difference in the model 1572414-83-5 supplier parameters for fitted the diffuse reflectance spectra of units 1 and 2 and arranged 3. However, the absorption due to NADH only was found to account for only 0 to 3% normally of the total absorption across the wavelength range of 350 to 600 nm, having a imply of 0.4% and a standard deviation of 2%. This indicated that NADH did not contribute significantly to the absorption with this wavelength range, and the absorption and scattering properties from the three units of cells spectra are still similar. The absorption properties yielded from your model and used in further data analysis then include represents the contribution and then represents the fractional fluorescence contribution from an individual component to that ...
Planned hyperspectral satellite missions and the decreased revisit time of multispectral imaging offer the potential for data fusion to leverage both the spectral resolution of hyperspectral sensors and the temporal resolution of multispectral constellations. Hyperspectral imagery can also be used to better understand fundamental properties of multispectral data. In this analysis, we use five flight lines from the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) archive with coincident Landsat 8 acquisitions over a spectrally diverse region of California to address the following questions: (1) How much of the spectral dimensionality of hyperspectral data is captured in multispectral data?; (2) Is the characteristic pyramidal structure of the multispectral feature space also present in the low order dimensions of the hyperspectral feature space at comparable spatial scales?; (3) How much variability in rock and soil substrate endmembers (EMs) present in hyperspectral data is captured by ...
The book Modern Optical Spectroscopy: With Examples from Biophysics and Biochemistry explains the theory of optical spectroscopic phenomena and demons
Hyperspectral imaging (HSI) provides images with numerous spectral bands over a continuous spectral range, enabling analysis of complex scenes that co
The primary objective of this pilot study is to calculate the sensitivity and specificity for discriminating tumor and benign tissues in vivo in colorectal cancer patients based on optical spectroscopy measurements. The secondary objective of this study is to calculate the spectral differences between in vivo and ex vivo measurements and the difference in the biological parameters (i.e. blood, water and fat content and blood oxygenation) that are extracted from the spectral information ...
A guided-mode resonance (GMR) filter with the same material (Ta2O5) for both the grating layer and the waveguide layer is designed and fabricated. This simple structure is easy to fabricate and can avoid the defects at the grating/waveguide interface using different materials. The spectral response measured with a Lambda 900 spectrophotometer under normal incidence for TE waves exhibits a peak reflectance exceeding 80% at the wavelength of 1040 nm with a full-width half-maximum (FWHM) linewidth of 23 nm. We evaluate the deviations of the fabricated structure from the designed parameters.. © 2010 Chinese Optics Letters. PDF Article ...
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies. ...
Watch this video demonstration on how to use a spectrum analyzer, general RF spectrum analysis, and RF / EMC spectrum analyzer operations.
Learn the fundamentals of real-time spectrum analysis and how you can extend the performance of your PXI vector signal analyzer with high-throughput processing from the LabVIEW FPGA Module. 
This document describes several approaches to implementing wideband spectrum analysis using the NI USRP™ (Universal Software Radio Peripheral) platform. After addressing how to acq...
Hyperspectral imaging (HSI) is a technique that analyzes a wide spectrum of light coming into a camera. Instead of assigning individual pixels to primary c
Is there such a beast? I just did a spectrum analysis of two of my reference tracks, and they both had a frequency cut off at about 17khz. I dont...
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Develop a broad, flexible level of knowledge of city and regional or town and country planning with our MSc Spatial Planning. Accredited by RTPI and RICS.
A means for intracavity sum frequency generation is described in which a er operates simultaneously, cw, at two wavelengths where the net gain at one wavelength is substantially lower than that at the other. The optical alignment of the resonator provides a region where both fundamental wavelengths are overlapped, and another region where both feedback paths are spatially distinct. An active feedback mirror is located in the path of the lower net gain laser transition to provide optical amplification at that wavelength. The laser resonator further contains a sum frequency generating crystal for intracavity sum frequency generation of the two fundamental wavelengths. The sum frequency generating crystal is placed near a laser resonator cavity mode waist in the region where both wavelengths are spatially superimposed, producing the sum frequency of the two wavelengths. An intracavity polarization rotator provides the appropriate orientation of the polarization of the two fundamental wavelengths in the
Surface-enhanced IR-visible sum frequency generation (SFG) was studied using Ag and Au films over nanospheres (AgFON and AuFON), which provided large area of reproducible nanoscale structures with well-defined morphology. SFG vibrational spectra for a self-assembled monolayer of octadecanethiol were investigated on spheres with diameters ranging from 300 nm to 620 nm. With an input wavelength of 532 nm, a sphere diameter near 360 nm produced the maximum enhancement, which was consistent with the localized surface-plasmon resonant wavelength identified by minimum reflectivity. The measured second-order susceptibility for the asymmetric CH3 stretch mode of octadecanethiol was enhanced by up to 27 times on AgFON, which corresponded to an SFG enhancement factor of similar to 730. The SFG enhancement factor for AuFON was a quarter of that from AgFON. The SFG enhancement factor for the symmetric CH3 mode was about 10 times smaller than that for the asymmetric CH3 mode. This difference can be explained ...
Dielectric spectroscopy (DS) of living biological cells is based on the analysis of the complex dielectric permittivity of cells suspended in a physiological medium. It provides knowledge on the polarization-relaxation response of cells to external electric field as function of the excitation frequency. This response is strongly affected by both structural and molecular properties of cells and therefore, can reveal rare insights on cell physiology and behaviour. This study demonstrates the mapping potential of DS after cytoplasmatic and membranal markers for cell-based screening analysis. The effect of membrane permittivity and cytoplasm conductivity was examined using tagged MBA and MDCK cell lines respectively. Comparing the permittivity spectra of tagged and native cell lines reveals clear differences between the analyzed suspensions. In addition, differences on the matching dielectric properties of cells were obtained. Those findings support the high distinction resolution and sensitivity of DS
The diffractive features of angular distribution have been investigated by analyzing the experimental data for a set of elastic scattering processes of {sup 7}Li by different target nuclei at different laboratory energies. Both Frahn-Venter and McIntyre models are used to analyze experimental data of angular distribution for elastic scattering processes. The theoretical models can reasonably reproduce the general pattern of the data. Some geometrical parameters for colliding nuclei have been obtained from the elastic scattering processes. It is found that interpretation of the diffractive features of the data is model-independent. The values of extracted parameters, from adopted models, are found comparable to each other and to those of others. The total reaction cross section is correlated to the incident laboratory energy for each scattering and values of total reaction cross section are found comparable with those of others. ...
Plant Analysis by Laser Induced Breakdown Spectroscopy (LIBS) - Agriculture - Agriculture Monitoring and Testing by Applied Spectra, Inc.. Laser-induced breakdown spectroscopy (LIBS) offers the ability to analyze plant samples with little to no sampl...
单分子力谱 的翻译结果:single-molecule force spectroscopy;single molecule force spectroscopy;single molecular force spectroscopy||双语例句|英文例句|相关文摘
We have observed a new mechanism for photon-gated spectral hole burning, donor-acceptor electron transfer, in a material composed of a zinc-tetrabenzoporphyrin derivative (donor) with chloroform acceptors in poly(methyl methacrylate) thin films. Gated holes form when we simultaneously excite the donor 0-0 singlet absorption (630 nm) and the donor triplet-triplet absorption (350-550 nm), with the largest gating enhancement (,30) occurring for gating light near 480 nm. The gating action spectrum and the photoproduct spectrum confirm that the mechanism is electron transfer from an excited triplet of the porphyrin donor to the chloroform acceptor. This result opens up a new class of materials for photon gating that should be of interest for frequency-domain optical storage applications as well as high-resolution spectroscopy of electron transfer processes in solids.. © 1987 Optical Society of America. Full Article , PDF Article ...
Spectroscopy & Spectrum Analysis | Browse New and Used Spectroscopy & Spectrum Analysis Textbooks & Textbook Rentals | ValoreBooks.com
Drusen, the hallmark lesions of age related macular degeneration (AMD), are biochemically heterogeneous and the identification of their biochemical distribution is key to the understanding of AMD. Yet the challenges are to develop imaging technology and analytics, which respect the physical generation of the hyperspectral signal in the presence of noise, artifacts, and multiple mixed sources while maximally exploiting the full data dimensionality to uncover clinically relevant spectral signatures. This paper reports on the statistical analysis of hyperspectral signatures of drusen and anatomical regions of interest using snapshot hyperspectral imaging and non-negative matrix factorization (NMF). We propose physical meaningful priors as initialization schemes to NMF for finding low-rank decompositions that capture the underlying physiology of drusen and the macular pigment. Preliminary results show that snapshot hyperspectral imaging in combination with NMF is able to detect biochemically ...
With 1.6 million deaths per year, lung cancer is one of the leading causes of death worldwide. One reason for this high number is the absence of a preventive medical examination method. Many diagnoses occur in a late cancer stage with a low survival rate. An early detection could significantly decrease the mortality. In recent decades, certain substances in human breath have been linked to certain diseases. Different studies show that it is possible to distinguish between lung cancer patients and a healthy control group by analyzing the volatile organic compounds (VOCs) in their breath. We developed a sensor based on photoacoustic spectroscopy for six of the most relevant VOCs linked to lung cancer. As a radiation source, the sensor uses an optical-parametric oscillator (OPO) in a wavelength region from 3.2 µm to 3.5 µm. The limits of detection for a single substance range between 5 ppb and 142 ppb. We also measured high resolution absorption spectra of the biomarkers compared to the data currently
In this paper we report the development and application of photoacoustic spectroscopy (PAS) for the detection and characterization of transient intermediates with lifetimes on the picosecond...
Find photoacoustic spectroscopy articles on Environmental XPRT, the worlds largest environmental industry marketplace and information resource.
Wang, HF. Quantitative analysis of vibrational spectrum and orientational order in Sum Frequency Generation Vibrational Spectroscopy (SFG-VS) studies on molecular interfaces[J]. ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY,2005,230:U303-U303 ...
JILA is a joint physics institute of the University of Colorado at Boulder and the National Institute of Standards and Technology. We support an eclectic and innovative research program that fosters creative collaborations among our scientists. Collaborations play a key role in the pioneering research JILA and the JILA Physics Frontier Center are known for around the world. To learn more, visit our About JILA page.. ...
Optical Spectroscopy has shown promise as a fundamental characterization tool for carbon nanotubes (CNTs). With the potential of CNTs being utilized for aerospace applications, in-situ techniques including temperature and strain measurements with spectroscopy, are gaining significance. These techniques will provide valuable information to advance design and tailoring of CNT reinforcements in composites for maximum strength or damping. Development of these in-situ techniques allow for the study of the effects of external parameters on the spectra of CNTs. The results from these in-situ studies can further be used to develop non-invasive measurement capabilities to establish the integrity of CNT reinforced materials. In this study, changes in the peaks width, intensity, area, and peak location were analyzed under an expansive in-situ temperature range, using a novel deconvolution and fitting algorithm. The findings are significant to the development of optical spectroscopy techniques as characterization
PUBLICATIONS - CONFERENCES - PRESENTATIONS. A. Gates, "State of the Art Protein Secondary Structure Prediction Using a Novel Two-Stage Alignment and Machine Learning Method" Dissertation Publication: University of Florida Library, 2008. Bolton, P. Gader, and A. Gates, "Embedding Multiple Instances: Applications to Hyperspectral Image Analysis", Proceedings of the IEEE Workshop on Hyperspectral Image Signal Processing: Evolution in Remote Sensing, Gainesville, 2013. Hohensee, L. Johnson, A. Gates, "Leveraging Google Apps to Enhance Online Learning in Mathematics", American Mathematical Association of Two Year Colleges, 2014. A Gates, A. & Bolton, J. (2015). The Effectiveness of Twitter as an Adjunctive Pedagogical Tool for Online Statistics Education: An Empirical Study. In Proceedings of Society for Information Technology & Teacher Education International Conference 2015 (pp. 2834-2840). Chesapeake, VA: Association for the Advancement of Computing in Education (AACE/SITE).. A. Gates, "Methods of ...
Known particles that may cause such scattering include neutrinos and antineutrinos (three flavours each) which are also seen in inelastic destruction and formation processes. Also, since dark matter is thought to not fit neutrino properties, that also means unknown number of different dark matter particles are eligible to cause elastic scattering of visible particles ...
When polymer power cables were introduced into mediumvoltage applications in the late 1960s, the degradationphenomenon later referred to aswater treeingwas still unknown. However, this changedwithin a relatively short space of time. Just 5-10 years afterthese first polymer applications, faults began to appear thatcould be attributed to the new phenomenon-water treeing. Sincethen, cable manufacturers have been improving their designsgradually, and cables produced today are assumed to have muchlower susceptibility to water trees. However, water treeing isstill assumed to be the most important degradation process inthese applications.. There are huge amounts of polymer cable installations thatare degraded by water trees. Since many of these cables areinstalled in the same grid nets, one cable fault oftengenerates another. If two or more cables fail at the same time,the consequences can be extensive. A non-destructive diagnosticmethod makes it possible to assess cables and take action priorto ...
High-resolution C 1s near-edge x-ray absorption fine structure (NEXAFS) spectra of naphthalene are investigated. By comparing the spectral signatures of condensed naphthalene molecules with those of naphthalene in the gas phase, we are able to unambiguously identify spectral features which are affected by the intermolecular interactions in the condensed phase. With the help of calculations using time-dependent density-functional theory and the second-order algebraic-diagrammatic construction scheme for the polarization propagator, resonances in the relevant energy range can be assigned to valence and Rydberg-like excitations. Thus, we obtain a more detailed identification of NEXAFS resonances beyond the present literature.. ...
A spectroscopy device that separates input light into a plurality of wavelength ranges. A metal body has a hole or aperture which is open on the upper side. The hole or aperture is formed in a polygonal shape having at least a pair of opposite faces not parallel to each other in horizontal cross-section. Inner side faces of the hole or aperture are finished as mirror like reflection surfaces. Polarized input light inputted from the opening to the hole or aperture is reflected by the reflection surfaces and a standing wave is generated inside of the hole or aperture by self interference, whereby the input light is separated into a plurality of wavelength ranges.
The S10121-256Q-01 is self-scanning photodiode arrays designed specifically as detectors for spectroscopy. The scanning circuit operates at low power consumption and is easy to handle. This photodiode has a large photosensitive area with high sensitivity and smoothly varying spectral response characteristics in UV region. Features-High UV sensitivity-High UV sensitivity than previous type-Smoothly varying spectral response characteristics in UV region-Variable integration time for each pixel-Wide photosensitive area Pixel pitch: 50 μm Pixel height: 2.5 mm-Large saturation output charge
The K3413-08 is a hybrid detector containing an infrared-transmitting Si photodiode mounted over an InGaAs PIN photodiode, along the same optical axis. This structure delivers a wide spectral response range from 0.25 μm to nearly 1.7 μm. The built-in thermoelectric cooler maintains a constant temperature during operation, allowing precision measurement with an improved S/N ratio.Features-Wide spectral response range-Si photodiode and InGaAs PIN photodiode are arranged along the same optical axis-One-stage thermoelectrically cooled type
In this study, an efficient spectral similarity method referred to as Weighted Chebyshev Distance (WCD) is introduced for supervised classification of hyperspectral imagery (HSI) and target detection applications. The WCD is based on a simple spectral similarity based decision rule using limited amount of reference data. The estimation of upper and lower spectral boundaries of spectral signatures for all classes across spectral bands is referred to as a vector tunnel (VT). To obtain the reference information, the training signatures are provided randomly from existing data for a known class. After determination of the parameters of the WCD algorithm with the training set, classification or detection procedures are accomplished at each pixel. The comparative performances of the algorithms are tested under various cases. The decision criterion for classification of an input vector is based on choosing its class corresponding to the narrowest VT that the input vector fits in to. This is also shown to be
BioMEMS as microsystems designed for biomedical and biological applications provide various functions from micro implants, Lab-on-chip, PoC diagnostics to biosensors. This paper focuses on the sensing capability of BioMEMS in cell characterization, drug screening and biofilm detection. In situ staining and electrical approaches as impedance spectroscopy, dielectric spectroscopy and contactless impedimetric sensing are presented and discussed for applications in 3D cell culturing, for drug screening, sedimentation analysis in aquatic research and biofilm detection in indwelling devices.. Download. ...
misc{4936673, abstract = {Optical spectroscopy is commonly used in technology and science today. The presence and concentration of a substance can be determined by its spectral signature, the typical wavelengths that are absorbed (or emitted) by the atoms or molecules. Standard absorption spectroscopy requires that the substance is clear and that the optical path-length is known to obtain quantitative information. Unfortunately in many materials, such as human tissue or pharmaceutical tablets, there are also a strong scattering of light which complicates measurements. The pathlength of the light is now no longer known and the intensity of the detected light can in many cases be more affected by high scattering than by the absorption values. One method to separate these two values are photon Time-of-Flight Spectroscopy (TOFS). By sending many short light pulses through a sample, and recording the time for a single photon to arrive at our detector for each pulse, we can build a histogram that ...
Hyperspectral imagery is a new class of image data which is mainly used in remote sensing. It is characterized by a wealth of spatial and spectral information that can be used to improve detection and estimation accuracy in chemical and biological standoff detection applications. Finding spectral endmembers is a very important task in hyperspectral data exploitation. Over the last decade, several algorithms have been proposed to find spectral endmembers in hyperspectral data. Existing algorithms may be categorized into two different classes: 1) endmember extraction algorithms (EEAs), designed to find pure (or purest available) pixels, and 2) endmember generation algorithms (EGAs), designed to find pure spectral signatures. Such a distinction between an EEA and an EGA has never been made before in the literature. In this paper, we explore the concept of endmember generation as opposed to that of endmember extraction by describing our experience with two EGAs: the optical real-time adaptative ...
EN] Dielectric spectroscopy studies have been performed on fresh and osmotically dehydrated Granny Smith apples. The osmotic treatment consisted on immerse the samples into 65% (w/w) sucrose aqueous solution at 30 degrees ...
This paper describes how reflected broadband sound signals are marked by interference phenomena if the surface of the ensonified object is structured. For an efficient extraction of features of the signal that relate to the surface structure of the object, the calculation of the cepstrum is introduced. A cylindrical test object is presented, which shows an angle independent and an angle dependent structure. This allows to specify the accuracy of the discrimination of structure sizes, that is based on a selected part of the cepstrum. In addition, the object can be used as a landmark for ultrasonic sensing. Classification of the cepstra is done by the statistical One Nearest Neighbour (1NN) method as well as by a Kohonen Self-Organising Feature Map (SOM). The results show, that changes in structure size down to 0.1mm are detectable ...
Fluorescence and phosphorescence detecting apparatus | Series absorbance glass and interference filters | Sample test cards | High sensitivity metamaterial nano-sensing system with ultra-narrow line width spectral response | Coherently receiving simultaneous optical-based electrical signals |
d {\displaystyle L>d} , U 1 , … , U d {\displaystyle U_{1},\ldots ,U_{d}} be the eigenvectors (left singular vectors of the L {\displaystyle L} -trajectory matrix), which are provided by the SVD step of SSA. Then this series is governed by an LRR x n = ∑ k = 1 L − 1 a k x n − k {\displaystyle x_{n}=\sum _{k=1}^{L-1}a_{k}x_{n-k}} , where ( a L − 1 , … , a 1 ) T {\displaystyle (a_{L-1},\ldots ,a_{1})^{\mathrm {T} }} are expressed through U 1 , … , U d {\displaystyle U_{1},\ldots ,U_{d}} (Golyandina et al., 2001, Ch.5), and can be continued by the same LRR. This provides the basis for SSA recurrent and vector forecasting algorithms (Golyandina et al., 2001, Ch.2). In practice, the signal is corrupted by a perturbation, e.g., by noise, and its subspace is estimated by SSA approximately. Thus, SSA forecasting can be applied for forecasting of a time series component that is approximately governed by an LRR and is approximately separated from the residual. Multi-channel, Multivariate SSA ...
A scanning system that combines broadband diffuse optical spectroscopy and diffuse correlation spectroscopy for non-contact, large field-of-view imaging of small animal models and humans is presented and demonstrated in vivo.. ...
Organic Chemists from Industry and academics to Interact on Spectroscopy Techniques for Organic Compounds ie NMR, MASS, IR, UV Etc.
Organic Chemists from Industry and academics to Interact on Spectroscopy Techniques for Organic Compounds ie NMR, MASS, IR, UV Etc.
In radio, a continuous sequence of broadcasting frequencies within given limits. In radiometry, a relatively narrow region of the electromagnetic spectrum to which a remote sensor responds; a multispectral sensor makes measurements in a number of spectral bands.
The aim of this thesis is to investigate the spectroscopic and structural properties of the TTBC J-aggregates. Absorption, emission and excitation spectroscopy techniques are used to study the properties of the J-aggregates ...
Ra-223 (Z= 88, A=223), MT=102 (n,γ) Ra-224 (Z= 88, A=224), MT= 2 (Elastic scattering) Ra-224 (Z= 88, A=224), MT= 4 (Inelastic scattering) Ra-225 (Z= 88, A=225), MT= 16 (n,2n) Ra-226 (Z= 88, A=226), MT= 17 (n,3n ...
Alguard, M.J., Ash, W.W., Baum, G., Clendenin, J.E., Cooper, P.S., Coward, D.H., Ehrlich, R.D., Etkin, A., Hughes, V.W., Kobayakawa, H., Kondo, K., Lubell, M.S., Miller, R.H., Palmer, D.A., Raith, W., Sasao, N., Schüler, K.P., Sherden, D.J., Sinclair, C.K., Souder, P.A.: Elastic scattering of polarized electrons by polarized protons. Phys.Rev.Lett. 37, 1258-1261 (1976 ...
The Site Master S362E with integrated spectrum analysis capability provide users with a high-performance, easy-to-use, feature-rich spectrum analyzer for field environments and applications requiring mobility.
Wavelength range: 190 to 1,100 nm; 4 nm spectral bandpass. Determination of the color of water and solutions, detection of the presence of dyestuff, quantification of dissolved ions and compounds, etc ...
The N K-edge X-ray absorption near edge structure (XANES) spectra of the purine-containing nucleotide, guanosine 5{sup ′}-monophosphate (GMP), in aqueous solution are measured under various pH conditions. The spectra show characteristic peaks, which originate from resonant excitations of N 1s electrons to π* orbitals inside the guanine moiety of GMP. The relative intensities of these peaks depend on the pH values of the solution. The pH dependence is explained by the core-level shift of N atoms at specific sites caused by protonation and deprotonation. The experimental spectra are compared with theoretical spectra calculated by using density functional theory for GMP and the other purine-containing nucleotides, adenosine 5{sup ′}-monophosphate, and adenosine 5{sup ′}-triphosphate. The N K-edge XANES spectra for all of these nucleotides are classified by the numbers of N atoms with particular chemical bonding characteristics in the purine moiety. ...
TY - JOUR. T1 - Femtosecond transient absorption of zinc porphyrins with oligo(phenylethylnyl) linkers in solution and on TiO2 films. AU - Chang, Chih Wei. AU - Luo, Liyang. AU - Chou, Chung Kung. AU - Lo, Chen Fu. AU - Lin, Ching Yao. AU - Hung, Chen Shiung. AU - Lee, Yuan Pern. AU - Diau, Eric Wei Guang. PY - 2009/7/9. Y1 - 2009/7/9. N2 - We measured femtosecond transient absorption of dye solutions and TiO 2 films sensitized with two zinc porphyrins (PE1 and PE4) to investigate the interfacial dynamics of electron transfer in relation to the dependence of cell performance on the length of the linker (Lin, C.-Y.; Lo, C.-F.; Luo, L.; Lu, H.-P.; Hung, C.-S.; Diau, E. W.-G. J. Phys. Chem. C 2009, 113, 755-764). For both porphyrins adsorbed on TiO2 films with S 1 excitation (λex = 620 nm), the transient absorption kinetics probed at 630 nm and 4.9 μm are complementary to each other because only the excited-state and ground-state species were observed at 630 nm whereas only the charge-separation ...
Sum frequency generation (SFG) vibrational spectroscopy was used to investigate the interfacial properties of several amino acids, peptides, and proteins adsorbed at the hydrophilic polystyrene solid-liquid and the hydrophobic silica solid-liquid interfaces. The influence of experimental geometry on the sensitivity and resolution of the SFG vibrational spectroscopy technique was investigated both theoretically and experimentally. SFG was implemented to investigate the adsorption and organization of eight individual amino acids at model hydrophilic and hydrophobic surfaces under physiological conditions. Biointerface studies were conducted using a combination of SFG and quartz crystal microbalance (QCM) comparing the interfacial structure and concentration of two amino acids and their corresponding homopeptides at two model liquid-solid interfaces as a function of their concentration in aqueous solutions. The influence of temperature, concentration, equilibration time, and electrical bias on the extent
In situ X-ray Absorption Spectroscopy (XAS) results are presented for Li2FeSiO4 and Li2.2Fe0.9SiO4, promising cathode materials for lithium-ion batteries. The aims are to establish the valence and local structure of Fe during charge and discharge to understand if the Fe3+/Fe4+ redox pair can be reac Celebrating the 2016 RSC Prize and Award Winners Highlighting materials research in the UK for energy and sustainability
X-ray absorption spectroscopy (XAS). -EXAFS (extended X-ray absorption fine structure) for determination of metal site fine structures (metal-metal and metal-ligand distances at ~0.02 Å resolution, chemical nature and number of metal ligands).. -XANES (X-ray absorption near edge structure) for determination of metal oxidation state and site geometry. ...read more, for example here or here X-ray absorption linear dichroism spectroscopy (XALDS) for determination of orientations of interatomic vectors within, for example, the protein matrix, in crystals and partially oriented systems (such as proteins in biological membranes). ...read more, for example here or here. XAS under elevated gas pressure ...read more, for example here. X-ray emission spectroscopy (XES) for probing metal oxidation state, spin state, site geometry, electronic configuration, ligand structures, etc. ...read more, for example here or here. Time-resolved XAS/XES to follow structural changes and redox transitions at metal ...
Polarization-dependent grazing incidence X-ray Absorption Spectroscopy (XAS) measurements were completed on oriented single crystals of magnesite [MgCO3] and brucite [Mg(OH)2] reacted with aqueous uranyl chloride above and below the solubility boundaries of schoepite (500, 50, and 5 ppm) at pH 8.3 and at ambient (PCO2 = 10-3.5) or reduced partial pressures of carbon dioxide (PCO2 = 10-4.5). X-ray Absorption Near Edge Structure (XANES) spectra show a striking polarization dependence ( = 0° and  = 90° relative to the polarization plane of the incident beam) and consistently demonstrated that the uranyl molecule was preferentially oriented with its Oaxial=U(VI)=Oaxial linkage at high angles (60-80º) to both magnesite () and brucite (0001). Extended X-ray Absorption Fine Structure (EXAFS) analysis shows that the "effective" number of U(VI) axial oxygens is the most strongly affected fitting parameter as a function of polarization. Furthermore, axial tilt in the surface thin films (thickness ...
The principal method of probing the structure of these films was the non-linear optical technique of Sum Frequency Generation (SFG). The experimental techniques used in this work are first introduced together with a theoretical description of SFG. There then follows an overview which describes semiconductor nanoparticle monolayers and the application of SFG to them. The work was subsequently extended to the investigation of multilayers of semiconductor nanoparticles incorporated within fatty acid films. Whilst SFG of monolayers is well understood SFG of multilayer films is not and most of this dissertation has been devoted to providing a systematic description of SFG of multilayer films adsorbed onto both metal and dielectric substrates. The observed multilayer SFG spectrum is shown to be a superposition of SFG signals coming from the surface layer, in contact with air, and the lowermost layer, in contact with the substrate. The SFG spectrum is a simple numerical addition of the two signals when ...
As essential media currently used in several technological applications, the accurate molecular level description of ionic liquids (ILs) at the gas-liquid interface is of utmost importance. The inherently surface-sensitive technique, sum frequency generation (SFG) spectroscopy, in combination with bulk-sensitive vibrational spectroscopic techniques such as FTIR and Raman, have been used in this report to characterize the surface of cyano-containing ILs, such as [BMIM][SCN], [BMIM][DCA], [BMIM][TCM], and [EMIM][TCB] at the gas-liquid interface. By structural variation of the anion while keeping the cation constant, emphasis on the molecular arrangement of the anion at the gas-liquid interface was reported. Vibrational modes seen in the C-H stretching region revealed the presence of the cation with an orientation independent of the type of anion. A similar arrangement at the surface as reported in previous studies was found. All three anions of varying symmetry, namely, [DCA]- (C2v), [TCM]-(D3h), ...
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When the number of training samples is limited, feature reduction plays an important role in classification of hyperspectral images. In this paper, we propose a supervised feature extraction method based on discriminant analysis (DA) which uses the first principal component (PC1) to weight the scatter matrices. The proposed method, called DA-PC1, copes with the small sample size problem and has not the limitation of linear discriminant analysis (LDA) in the number of extracted features. In DA-PC1, the dominant structure of distribution is preserved by PC1 and the class separability is increased by DA. The experimental results show the good performance of DA-PC1 compared to some state-of-the-art feature extraction methods.
Looking for definition of spectrum analysis? spectrum analysis explanation. Define spectrum analysis by Websters Dictionary, WordNet Lexical Database, Dictionary of Computing, Legal Dictionary, Medical Dictionary, Dream Dictionary.
Metabolic Syndrome is a highly prevalent condition that is comprised of several major clustering factors that increase the risk for developing cardiovascular disease. Diffuse Optical Spectroscopy is a non-invasively measure can show changes in the microvasculature of human. Diffuse Optical Spectroscopy measures the optical absorption and scattering properties of near-infrared light in tissues such as muscle in order to quantify the absolute concentration of oxygenated and deoxygenated hemoglobin, water, and lipids. It provides quantitative and functional information on the microvasculature related to tissue perfusion, metabolic changes, and indicators of tissue damage ...
The electronic properties of Au crystal and nano Au have been investigated by theory and experiment. Molecularly capped nano-Au was synthesized using the two-phase method. Au nano-particles have been characterized by X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). They retain the fcc crystal structure. Their sizes have been determined to be in a range from 5.5 nm to 1.7 nm. The L3 X-ray Absorption Near Edge Structure (XANES) of nano-Au and Au foil have been recorded using synchrotron radiation, and examined by theoretical calculation [1] based on the first principles [2,3]. Both theory and experiment show that the nano-Au particles have essentially all the Au L3 XANES features of bulk Au in the near edge region with less pronounced resonance peaks. It is also shown that nano Au exhibits lower 4f binding energy than bulk Au in good agreement with quantum confined Au systems reported previously [3,4].
The usage of steel powders prealloyed with chromium in PM components for high performance applications is steadily increasing. Excellent mechanical properties are achieved with these powder grades, provided that the processing into components is accurately done. Photoacoustic spectroscopy (PAS) technique has been used here to study oxide reduction during sintering in 90N2/10H2 atmosphere of test specimens based on 3%Cr-0.5%Mo prealloyed powders with 0.5% C added. Results from performed reduction trials show that Fe oxides on the powder surfaces are removed by H2 reduction early in the heating stage of the process. Carbothermal reduction is the main mechanism for reduction of stable Cr-containing oxides from 900°C and above. Efficient Cr oxide reduction requires a sintering temperature of at least around 1200°C. Therefore, small oxide particles remain in the material after sintering at 1120°C for 30 minutes. However, such oxides have earlier been shown to have no significant influence on mechanical
Description: In this research, hyperspectral and multispectral images were utilized for vegetation studies in the greenbelt corridor near Denton. EO-1 Hyperion was the hyperspectral image and Landsat Thematic Mapper (TM) was the multispectral image used for this research. In the first part of the research, both the images were classified for land cover mapping (after necessary atmospheric correction and geometric registration) using supervised classification method with maximum likelihood algorithm and accuracy of the classification was also assessed for comparison. Hyperspectral image was preprocessed for classification through principal component analysis (PCA), segmented principal component analysis and minimum noise fraction (MNF) transform. Three different images were achieved after these pre-processing of the hyperspectral image. Therefore, a total of four images were classified and assessed the accuracy. In the second part, a more precise and improved land cover study was done on ...
A broad range of chemical reactions are triggered by the absorption of light. Examples include photosynthesis and charge transfer in semiconductors and molecules. Electronic dynamics which evolve on the few femtosecond to attosecond timescale are expected to play an important role in these processes. We aim to investigate these dynamics with transient X-ray absorption near edge structure (XANES) spectroscopy. XANES spectroscopy uses resonant excitation of particular atoms in a molecule to provide a highly localised probe of electronic structure. By employing attosecond soft x-ray pulses generated via high harmonic generation for XANES spectroscopy this atomic scale spatial resolution can in principle be combined with the attosecond temporal resolution required for tracking electronic dynamics. I shall present development of a beamline for transient XANES spectroscopy and progress towards visible pump, soft x-ray probe experiments in the organic polymer poly(hexylthiophene ...
Summary One of the major challenges in understanding the complex immune system is the question when and why this defense system attacks endogenous proteins (i.e. self-proteins). Currently, there are no reliable methods to predict what induces such an immune response, despite it has a major impact in medicine by causing autoimmune diseases, and in biotechnology by inducing adverse reactions towards new drugs. PredicTOOL will concentrate on antibody-mediated immune reactions to endogenous proteins. By high sensitivity nanotechnological tools based on spectroscopic and imaging techniques (e.g. Circular Dichroism Spectroscopy, Single Molecule Force Spectroscopy, Isothermal Titration Calorimetry, Fluorescence Microscopy), PredicTOOL will identify common patterns that characterize the interaction of autoantibodies with their antigens and further interaction with cells of the immune system. We will use well characterized human model diseases (cardiovascular). The proposed technologies will allow ...
12 Apr 2017. NUS chemists have demonstrated an electrical field-controlled giant Stark effect in black phosphorus for potential applications in advanced electro-optic modulators and photodetector devices.. The bandgap is a material property that determines electrical conductivity. Solids with large bandgaps are generally insulators as they do not conduct electricity. Those with smaller bandgaps are semiconductors. A team of NUS researchers have demonstrated that the bandgap of black phosphorus (BP) changes in the presence of an electric field. By controlling the electric field strength, they have shown that the bandgap of BP can be adjusted to a desired level. This means that by changing the electric field, the material can be made to either conduct or not to conduct electricity. The findings can potentially be used for advanced optoelectronic devices operating beyond the visible light spectrum.. When a few atomic layers of BP are exposed to an electric field, a physical phenomenon known as the ...
Medical implants are increasingly often inserted into bone of frail patients, who are advanced in years. Due to age, severe trauma or pathology-related bone changes, osseous healing at the implant site is frequently limited. We were able to demonstrate that coating of endosseous implants with nanocrystalline diamond (NCD) allows stable functionalization by means of physisorption with BMP-2. Strong physisorption was shown to be directly related to the unique properties of NCD, and BMP-2 in its active form interacted strongly when NCD was oxygen-terminated. The binding of the protein was monitored under physiological conditions by single molecule force spectroscopy, and the respective adsorption energies were further substantiated by force-field-calculations. Implant surfaces refined in such a manner yielded enhanced osseointegration in vivo, when inserted into sheep calvaria. Our results further suggest that this technical advancement can be readily applied in clinical therapies with regard to ...
Femtosecond transient absorption spectrometer Our femtosecond transient absorption spectrometer is a homemade pump-continuum-probe setup. The main femtosecond laser source is a Ti:Sapphire system from Spectra-Physics (Tsunami oscillator followed by a Spitfire regenerative amplifier). It delivers 50-fs ~0.7 mJ pulses at 1 kHz around 800 nm. Tunable pump pulses in the visible are produced by a noncollinear optical parametric amplifier (NOPA, Clark-MXR). A broadband continuum probe is obtained by self-phase modulation of a 800-nm beam in a CaF2 plate. Its time delay with respect to the pump is adjusted in a motorized optical delay line. The pump and probe beams are focused with parabolic mirrors and overlapped in the sample, kept in a 1-mm cell. The sample may be constantly displaced in two directions to avoid the re-excitation of a previously excited area. The sample may also be thermostated with the help of a water bath circulated through the sample holder. Fig 1 gives a schematic view of the ...
Single-molecule force spectroscopy of bimolecular reactions: system homology in the mechanical activation of ligand substitution reactions.s profile, publications, research topics, and co-authors
TY - GEN. T1 - Epithelial cancer detection by oblique-incidence optical spectroscopy. AU - Garcia-Uribe, Alejandro. AU - Balareddy, Karthik C.. AU - Zou, Jun. AU - Wang, Kenneth Ke Ning. AU - Duvic, Madeleine. AU - Wang, Lihong V.. PY - 2009. Y1 - 2009. N2 - This paper presents a study on non-invasive detection of two common epithelial cancers (skin and esophagus) based on oblique incidence diffuse reflectance spectroscopy (OIDRS). An OIDRS measurement system, which combines fiber optics and MEMS technologies, was developed. In our pilot studies, a total number of 137 cases have been measured in-vivo for skin cancer detection and a total number of 20 biopsy samples have been measured ex-vivo for esophageal cancer detection. To automatically differentiate the cancerous cases from benign ones, a statistical software classification program was also developed. An overall classification accuracy of 90% and 100% has been achieved for skin and esophageal cancer classification, respectively.. AB - This ...
1. Classification of optical analytical methods, overview of methods of molecular spectroscopy, analytical and structural aspects of optical methods, radiation - matter interactions. Photometry and units. 2. Molecular absorption spectroscopy in UV and Vis spectral ranges: nature and character of UV and Vis spectra, molecular orbitals, symbols of molecular terms, multiplicity, electronic states of molecules. 3. Types of electronic transitions and their expressions in spectra, chromophores, auxochromes, shape and structure of absorption bands, vibronic transitions. 4. Electronic spectra of important classes of compounds: aliphatic unsaturated hydrocarbons, derivatives of aliphatic hydrocarbons, aromatic hydrocarbons, their heteroanalogues and substitute derivatives, organic dyes, inorganic ions and complexes of metal cations,, charge-transfer complexes. 5. Extrinsic and intrinsic effects influencing electronic spectra: steric effects, tautomeric equilibria, pH, solvents. Empiric calculations of ...
Through the development of powerful laser spectroscopy techniques new means for advanced diagnostics and sample analysis have emerged. Applications of laser spectroscopy in the fields of energy,...