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Near Infrared (near + infrared)
Terms modified by Near Infrared Selected AbstractsA physiochemical theory on the applicability of soft mathematical models,experimentally interpretedJOURNAL OF CHEMOMETRICS, Issue 7-8 2010L. Munck Abstract An extension of chemometric theory was experimentally explored to explain the physiochemical basis of the very high efficiency of soft modelling of data from nature. Soft modelling in self-organisation was interpreted by studying the unique chemical patterns of mutants in an isogenic barley model on endosperm development. Extremely reproducible, differential Near Infrared (NIR) spectral patterns specifically overviewed the effect on cell composition of each mutant cause. Extended Canonical Variates Analysis (ECVA) classified spectra in wild type, starch and protein mutants. The spectra were interpreted by chemometric data analysis and by pattern inspection to morphological, genetic, molecular and chemical information. Deterministic chemical reactions were defined in the glucan pathway. A drastic mutation in a gene controlling the starch/ß-glucan composition changed water activity that introduced a diffusive, stochastic effect on the catalysis of all active enzymes. ,Decision making' in self-organisation is autonomous and performed by the soft modelling of the chemical deterministic and stochastic reactions in the endosperm cell as a whole. Uncertainty in the analysis of endosperm emergence was experimentally delimited as the ,indeterminacy' in local molecular path modelling ,bottom up' and the ,irreducibility' of the phenomenological NIR spectra ,top down'. The experiment confirmed Ilya Prigogine's interpretation of self-organisation by his dynamic computer model programmed with a self-modeled non-local extension of quantum mechanics (QM). The significance of self- organisation explained by Prigogine here interpreted as physiochemical soft modelling introduces a paradigm shift in macroscopic science that forwards a major argument for soft mathematical modelling and chemometrics to obtain full scientific legitimacy. Copyright © 2010 John Wiley & Sons, Ltd. [source] Gas dynamics of the central few parsec region of NGC 1068 fuelled by the evolving nuclear star clusterMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2010M. Schartmann ABSTRACT Recently, high-resolution observations with the help of the near-infrared adaptive optics integral field spectrograph Spectrograph for INtegral Field Observations in the Near Infrared (SINFONI) at the Very Large Telescope proved the existence of massive and young nuclear star clusters in the centres of a sample of Seyfert galaxies. With the help of three-dimensional high-resolution hydrodynamical simulations with the Pluto code, we follow the evolution of such clusters, especially focusing on stellar mass loss feeding gas into the ambient interstellar medium and driving turbulence. This leads to a vertically wide distributed clumpy or filamentary inflow of gas on large scales (tens of parsec), whereas a turbulent and very dense disc builds up on the parsec scale. In order to capture the relevant physics in the inner region, we treat this disc separately by viscously evolving the radial surface density distribution. This enables us to link the tens of parsec-scale region (accessible via SINFONI observations) to the (sub-)parsec-scale region (observable with the mid-infrared interferometer instrument and via water maser emission). Thereby, this procedure provides us with an ideal testbed for data comparison. In this work, we concentrate on the effects of a parametrized turbulent viscosity to generate angular momentum and mass transfer in the disc and additionally take star formation into account. Most of the input parameters are constrained by available observations of the nearby Seyfert 2 galaxy NGC 1068, and we discuss parameter studies for the free parameters. At the current age of its nuclear starburst of 250 Myr, our simulations yield disc sizes of the order of 0.8,0.9 pc, gas masses of 106 M, and mass transfer rates of 0.025 M, yr,1 through the inner rim of the disc. This shows that our large-scale torus model is able to approximately account for the disc size as inferred from interferometric observations in the mid-infrared and compares well to the extent and mass of a rotating disc structure as inferred from water maser observations. Several other observational constraints are discussed as well. [source] VLT/SINFONI integral field spectroscopy of the Super-antennae,MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2007J. Reunanen ABSTRACT We present the results of H - and K -band very large telescope/Spectrograph for INtegral Field Observations in the Near Infrared (VLT/SINFONI) integral field spectroscopy of the Ultraluminous Infrared Galaxy (ULIRG) IRAS 19 254,7245 (the Super-antennae), an interacting double galaxy system containing an embedded active galactic nuclei. Deep K -band spectroscopy reveals Pa, arising in a warped disc with position angle of 330° and an inclination i= 40°,55°. The kinemetric parameters derived for H2 are similar to Pa,. Two high-ionization emission lines, [Si vi] and [Al ix], are detected and we identify as [Ni ii] the line observed at 1.94 ,m. Diluting non-stellar continuum, which was previously detected, has decayed, and the H -band continuum emission is consistent with pure stellar emission. Based on H2 emission-line ratios, it is likely that at the central 1-kpc region H2 is excited by ultraviolet fluorescence in dense clouds while shock excitation is dominant further out. This scenario is supported by very low Pa, to H2 line ratio detected outside the nuclear region and non-thermal ortho/para ratios (,2.0,2.5) close to the nucleus. [source] Polarimetry in Solar and Stellar Physics , Techniques, Observations and DiagnosticsASTRONOMISCHE NACHRICHTEN, Issue S3 2003Horst BalthasarArticle first published online: 18 JUL 200 D01 Split Pupil Imaging Polarimeters for Optical Night Time Astronomy D02 The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) for the LBT D03 Velocity and Magnetic Fields in Sunspot Penumbrae at Hight Spatial and Spectral Resolution D04 Infrared Polarimetry at the MPAe: The Solar Atmosphere from the Photosphere to the Upper Chromosphere D05 Properties of a Simple Sunspot Observed in the Near Infrared D06 Hausdorff-Dimension of Magnetic Structures D07 Distribution of the Magnetic Flux Density at the Solar Surface [source] In-line analysis of a fluid bed pellet coating process using a combination of near infrared and Raman spectroscopyJOURNAL OF CHEMOMETRICS, Issue 7-8 2010Andrey Bogomolov Abstract Near infrared (NIR) and Raman spectroscopic analyzers applied through an immersion Lighthouse Probe (LHP) were used for simultaneous in-line monitoring of a fluid bed pellet coating process. Multivariate curve resolution analysis of data, collected from four pilot-scale batches, has shown that the two techniques deliver complementary information about the process and their combination may be synergistic. This data analysis enabled a much better understanding of some of the process observations and also gave some interesting insights into the best way to use the techniques themselves. PLS regression analysis of the product moisture and the quantity of coating material sprayed was performed using NIR and Raman data blocks both separately and in combination. The performance of method combination compared to individual techniques is analyzed and discussed. Copyright © 2010 John Wiley & Sons, Ltd. [source] Multiphoton microscopy in life sciencesJOURNAL OF MICROSCOPY, Issue 2 2000K. König Near infrared (NIR) multiphoton microscopy is becoming a novel optical tool of choice for fluorescence imaging with high spatial and temporal resolution, diagnostics, photochemistry and nanoprocessing within living cells and tissues. Three-dimensional fluorescence imaging based on non-resonant two-photon or three-photon fluorophor excitation requires light intensities in the range of MW cm,2 to GW cm,2, which can be derived by diffraction limited focusing of continuous wave and pulsed NIR laser radiation. NIR lasers can be employed as the excitation source for multifluorophor multiphoton excitation and hence multicolour imaging. In combination with fluorescence in situ hybridization (FISH), this novel approach can be used for multi-gene detection (multiphoton multicolour FISH). Owing to the high NIR penetration depth, non-invasive optical biopsies can be obtained from patients and ex vivo tissue by morphological and functional fluorescence imaging of endogenous fluorophores such as NAD(P)H, flavin, lipofuscin, porphyrins, collagen and elastin. Recent botanical applications of multiphoton microscopy include depth-resolved imaging of pigments (chlorophyll) and green fluorescent proteins as well as non-invasive fluorophore loading into single living plant cells. Non-destructive fluorescence imaging with multiphoton microscopes is limited to an optical window. Above certain intensities, multiphoton laser microscopy leads to impaired cellular reproduction, formation of giant cells, oxidative stress and apoptosis-like cell death. Major intracellular targets of photodamage in animal cells are mitochondria as well as the Golgi apparatus. The damage is most likely based on a two-photon excitation process rather than a one-photon or three-photon event. Picosecond and femtosecond laser microscopes therefore provide approximately the same safe relative optical window for two-photon vital cell studies. In labelled cells, additional phototoxic effects may occur via photodynamic action. This has been demonstrated for aminolevulinic acid-induced protoporphyrin IX and other porphyrin sensitizers in cells. When the light intensity in NIR microscopes is increased to TW cm,2 levels, highly localized optical breakdown and plasma formation do occur. These femtosecond NIR laser microscopes can also be used as novel ultraprecise nanosurgical tools with cut sizes between 100 nm and 300 nm. Using the versatile nanoscalpel, intracellular dissection of chromosomes within living cells can be performed without perturbing the outer cell membrane. Moreover, cells remain alive. Non-invasive NIR laser surgery within a living cell or within an organelle is therefore possible. [source] Synthesis of Hexagonal Yb3+,Er3+ -Doped NaYF4 Nanocrystals at Low TemperatureADVANCED FUNCTIONAL MATERIALS, Issue 19 2009Helmut Schäfer Abstract Nanocrystals of NaYF4 doped with Yb3+ and Er3+ are synthesized in oleylamine using Y2(CO3)3, Yb2(CO3)3, Er2(CO3)3, Na2CO3, and NH4F as precursors. In contrast to other starting materials normally used for such syntheses, these precursors react even at room temperature to form hexagonal-phase (, -phase) NaYF4:Er,Yb nanoparticles. Cubic-phase (, -phase) NaYF4:Yb,Er particles are formed only at elevated temperatures (>250,°C). The formation of the cubic phase at high temperatures can be suppressed by replacing pure oleylamine with oleic acid/oleylamine mixtures. Under optimized reaction conditions, particles with an average particle size of about 7,nm are generated in 84% yield. Heat treatment (30,min, 280,°C) of the particles significantly increases the luminescence efficiency. A transparent solution of the heat-treated, nanometer-sized phosphor in toluene shows intense visible light emission upon excitation in the near infrared. [source] PbS and CdS Quantum Dot-Sensitized Solid-State Solar Cells: "Old Concepts, New Results"ADVANCED FUNCTIONAL MATERIALS, Issue 17 2009HyoJoong Lee Abstract Lead sulfide (PbS) and cadmium sulfide (CdS) quantum dots (QDs) are prepared over mesoporous TiO2 films by a successive ionic layer adsorption and reaction (SILAR) process. These QDs are exploited as a sensitizer in solid-state solar cells with 2,2,,7,7,-tetrakis(N,N -di- p -methoxyphenylamine)-9,9,-spirobifluorene (spiro-OMeTAD) as a hole conductor. High-resolution transmission electron microscopy (TEM) images reveal that PbS QDs of around 3,nm in size are distributed homogeneously over the TiO2 surface and are well separated from each other if prepared under common SILAR deposition conditions. The pore size of the TiO2 films and the deposition medium are found to be very critical in determining the overall performance of the solid-state QD cells. By incorporating promising inorganic QDs (PbS) and an organic hole conductor spiro-OMeTAD into the solid-state cells, it is possible to attain an efficiency of over 1% for PbS-sensitized solid-state cells after some optimizations. The optimized deposition cycle of the SILAR process for PbS QDs has also been confirmed by transient spectroscopic studies on the hole generation of spiro-OMeTAD. In addition, it is established that the PbS QD layer plays a role in mediating the interfacial recombination between the spiro-OMeTAD+ cation and the TiO2 conduction band electron, and that the lifetime of these species can change by around 2 orders of magnitude by varying the number of SILAR cycles used. When a near infrared (NIR)-absorbing zinc carboxyphthalocyanine dye (TT1) is added on top of the PbS-sensitized electrode to obtain a panchromatic response, two signals from each component are observed, which results in an improved efficiency. In particular, when a CdS-sensitized electrode is first prepared, and then co-sensitized with a squarine dye (SQ1), the resulting color change is clearly an addition of each component and the overall efficiencies are also added in a more synergistic way than those in PbS/TT1-modified cells because of favorable charge-transfer energetics. [source] Analysis of adobe wall composition at the Chaves-Hummingbird Site, New Mexico, by diffuse reflectance spectrophotometryGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 8 2007William Balsam This article investigates adobe wall construction materials utilized by prehistoric inhabitants of Chaves-Hummingbird Pueblo, an ancestral Pueblo village located ,20 miles west of Albuquerque, New Mexico. The walls were constructed with native clay-rich soils some time between approximately 1275,1450 A.D. Samples were analyzed with a diffuse reflectance spectrophotometer from the near ultraviolet (NUV) through the visible (VIS) and into the near infrared (NIR) region of the electromagnetic spectrum. Cluster analysis of samples from 275 adobe walls and 36 soil locations surrounding the pueblo room blocks indicates four clusters. Comparison of typical samples from the four clusters indicates that they are very similar and are distinguished by minor variations in the three primary spectrally determined components, Na-Ca montmorillonite, bentonite, and goethite. In general, clusters correspond with room construction episodes that are discernible through patterns of wall bonding and abutment recorded during the archaeological investigation of the site. This suggests that during different phases of construction the source of the wall adobe changed. Many of the soil samples are included in wall clusters and therefore reveal a potential source of material used for adobe, adjacent soils. However, not all the soil surrounding the pueblo grouped with wall clusters indicating a preference for certain soil types and that some soils were probably unsuitable for making adobe. Therefore, diversity in spectrally identified construction materials provides insights into source locations and possible construction preferences of the site inhabitants. © 2007 Wiley Periodicals, Inc. [source] Single-Photon and Two-Photon Induced Photocleavage for Monolayers of an Alkyltriethoxysilane with a Photoprotected Carboxylic Ester,ADVANCED MATERIALS, Issue 23 2008Marta Álvarez The photochemical structuring of a polysiloxane monolayer protected with a photocleavable group is shown by femtosecond laser pulses in the near infrared. These experiments suggest a two-photon induced deprotection process that holds great promise for near-field monolayer photolithography far below the diffraction limit. [source] Real-time Visualization and Quantification of Retrograde Cardioplegia Delivery using Near Infrared Fluorescent ImagingJOURNAL OF CARDIAC SURGERY, Issue 6 2008Aravind T. Rangaraj M.D. Presently, there exist no established methods to quantitatively assess cardioplegia distribution intraoperatively and determine when retrograde cardioplegia is required. In this study, we evaluate the feasibility of near infrared (NIR) imaging for real-time visualization of cardioplegia distribution in a porcine model. Methods: A portable, intraoperative, real-time NIR imaging system was utilized. NIR fluorescent cardioplegia solution was developed by incorporating indocyanine green (ICG) into crystalloid cardioplegia solution. Real-time NIR imaging was performed while the fluorescent cardioplegia solution was infused via the retrograde route in five ex vivo normal porcine hearts and in five ex vivo porcine hearts status post left anterior descending (LAD) coronary artery ligation. Horizontal cross-sections of the hearts were obtained at proximal, middle, and distal LAD levels. Videodensitometry was performed to quantify distribution of fluorophore content. Results: The progressive distribution of cardioplegia was clearly visualized with NIR imaging. Complete visualization of retrograde distribution occurred within 4 minutes of infusion. Videodensitometry revealed retrograde cardioplegia, primarily distributed to the left ventricle (LV) and anterior septum. In hearts with LAD ligation, antegrade cardioplegia did not distribute to the anterior LV. This deficiency was compensated for with retrograde cardioplegia supplementation. Conclusions: Incorporation of ICG into cardioplegia allows real-time visualization of cardioplegia delivery via NIR imaging. This technology may prove useful in guiding intraoperative decisions pertaining to when retrograde cardioplegia is mandated. [source] In-line analysis of a fluid bed pellet coating process using a combination of near infrared and Raman spectroscopyJOURNAL OF CHEMOMETRICS, Issue 7-8 2010Andrey Bogomolov Abstract Near infrared (NIR) and Raman spectroscopic analyzers applied through an immersion Lighthouse Probe (LHP) were used for simultaneous in-line monitoring of a fluid bed pellet coating process. Multivariate curve resolution analysis of data, collected from four pilot-scale batches, has shown that the two techniques deliver complementary information about the process and their combination may be synergistic. This data analysis enabled a much better understanding of some of the process observations and also gave some interesting insights into the best way to use the techniques themselves. PLS regression analysis of the product moisture and the quantity of coating material sprayed was performed using NIR and Raman data blocks both separately and in combination. The performance of method combination compared to individual techniques is analyzed and discussed. Copyright © 2010 John Wiley & Sons, Ltd. [source] Hyperspectral NIR image regression part II: dataset preprocessing diagnosticsJOURNAL OF CHEMOMETRICS, Issue 3-4 2006James Burger Abstract When known reference values such as concentrations are available, the spectra from near infrared (NIR) hyperspectral images can be used for building regression models. The sets of spectra must be corrected for errors, transformed to reflectance or absorbance values, and trimmed of bad pixel outliers in order to build robust models and minimize prediction errors. Calibration models can be computed from small (<100) sets of spectra, where each spectrum summarizes an individual image or spatial region of interest (ROI), and used to predict large (>20,000) test sets of spectra. When the distributions of these large populations of predicted values are viewed as histograms they provide mean sample concentrations (peak centers) as well as uniformity (peak widths) and purity (peak shape) information. The same predicted values can also be viewed as concentration maps or images adding spatial information to the uniformity or purity presentations. Estimates of large population statistics enable a new metric for determining the optimal number of model components, based on a combination of global bias and pooled standard deviation values computed from multiple test images or ROIs. Two example datasets are presented: an artificial mixture design of three chemicals with distinct NIR spectra and samples of different cheeses. In some cases it was found that baseline correction by taking first derivatives gave more useful prediction results by reducing optical problems. Other data pretreatments resulted in negligible changes in prediction errors, overshadowed by the variance associated with sample preparation or presentation and other physical phenomena. Copyright © 2007 John Wiley & Sons, Ltd. [source] Comparison of FTIR, FT-Raman, and NIR Spectroscopy in a Maple Syrup Adulteration StudyJOURNAL OF FOOD SCIENCE, Issue 6 2002M. M. Paradkar ABSTRACT: Maple syrup is prone to adulteration with cheaper sugars, such as corn syrup, due to its simplicity in chemical composition. The adulterated samples were characterized by Fourier Transform infrared (FTIR) spectroscopy in the region of 400 to 4000 cm -1. Other techniques used for detection and in characterization of samples were the near infrared (NIR; 600 to 1700nm) and Fourier Transform-Raman (FT-Raman; 400 to 4000cm -1) spectroscopy. Quantifying and classifying adulterants using chemometrics shows that all spectroscopic methods adopted were efficient, but FTIR and FT-Raman were superior to NIR in quantitative characterization of adulterants in maple syrup. [source] Near infrared spectroscopy in the development of solid dosage formsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 2 2007Eetu Räsänen The use of near infrared (NIR) spectroscopy has rapidly grown partly due to demands of process analytical applications in the pharmaceutical industry. Furthermore, newest regulatory guidelines have advanced the increase of the use of NIR technologies. The non-destructive and non-invasive nature of measurements makes NIR a powerful tool in characterization of pharmaceutical solids. These benefits among others often make NIR advantageous over traditional analytical methods. However, in addition to NIR, a wide variety of other tools are naturally also available for analysis in pharmaceutical development and manufacturing, and those can often be more suitable for a given application. The versatility and rapidness of NIR will ensure its contribution to increased process understanding, better process control and improved quality of drug products. This review concentrates on the use of NIR spectroscopy from a process research perspective and highlights recent applications in the field. [source] Optical probing and imaging of live cells using SERS labelsJOURNAL OF RAMAN SPECTROSCOPY, Issue 1 2009Janina Kneipp Abstract During surface-enhanced Raman scattering (SERS), molecules exhibit a significant increase in their Raman signals when attached, or in very close vicinity, to gold or silver nanostructures. This effect is exploited as the basis of a new class of optical labels. Here we demonstrate robust and sensitive SERS labels as probes for imaging live cells. These hybrid labels consist of gold nanoparticles with Rose Bengal or Crystal Violet attached as reporter molecules. These new labels are stable and nontoxic, do not suffer from photobleaching, and can be excited at any excitation wavelength, even in the near infrared. SERS labels can be detected and imaged through the specific Raman signatures of the reporters. In addition, surface-enhanced Raman spectroscopy in the local optical fields of the gold nanoparticles also provides sensitive information on the immediate molecular environment of the label in the cell and allows imaging of the native constituents of the cell. This is demonstrated by images based on a characteristic Raman line of the reporter as well as by displaying lipids based on the SERS signal of the CH deformation/bending modes at ,1470 cm,1. Copyright © 2008 John Wiley & Sons, Ltd. [source] Fourier-transform Raman spectroscopy of archaeological resinsJOURNAL OF RAMAN SPECTROSCOPY, Issue 8 2008Howell G. M. Edwards Abstract The adoption of Raman spectroscopy as a first-pass screening technique for the presence of organic compounds on diverse substrates is now being advocated for the non-destructive examination of potential sites for limited sampling for other analytical techniques. In this paper, examples of the analytical capability of Raman spectroscopy using long wavelength excitation in the near infrared for the characterisation of archaeological resins from Egyptian Dynastic and pre-Dynastic periods and artefacts are used to illustrate the advantages and limitations of the technique. The resin specimens and artefacts span a period of about 7000 years. Raman spectra have been obtained of resin specimens from archaeological sites and of resins on several artefacts; from the latter it is possible to assess the influence of diverse substrates upon the spectral information that can be derived from the resins themselves. Key molecular spectral features are proposed for each resin studied and the presence of degradation assessed. Copyright © 2008 John Wiley & Sons, Ltd. [source] Anterior eye tissue transmission for the radiation with the wavelength from eye safe regionLASER PHYSICS LETTERS, Issue 12 2005H. Jelínková Abstract Comparison of the eye tissue transmission for six laser radiations from visible up to mid-infrared region was done. The attenuation of the alexandrite (visible 0.75 µm), and Nd:YAP (near infrared 1.08 µm) laser radiations was found to be minimal , a retina reachs ,46% energy of these lasers entering the eye. On the other side the radiations of 1.54 µm (Er:glass), 1.66 µm (Er:YAP), and 2.01 µm (Tm:YAG) lasers are absorbed by the anterior segments of the eye and no impact is appeared on the retina. The absorption values measured for 1.34 µm (Nd:YAP) was recorded to be between the curves obtained for two groups of radiation wavelengths mentioned above. On retina, only 0.5% of the cornea radiation level was found. In this case the anterior parts of the eye are affected partially but not so deeply as in the case of eye safe radiation application. (© 2005 by Astro, Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source] Properties of Some Alkyl Substituted Phthalocyanines and Related MacrocyclesTHE CHEMICAL RECORD, Issue 4 2002Michael J. Cook Abstract This report provides an account of research undertaken at the University of East Anglia, United Kingdom, into phthalocyanine derivatives substituted at six or more of the nonperipheral sites by alkyl groups. When first prepared they were only the second series of substituted phthalocyanines known to exhibit columnar liquid crystal behaviour. The compounds also form structured films by the spin-coating technique, a formulation with potential for FET devices. The zinc metallated derivatives are photosensitisers of singlet oxygen and show good potential for applications in photodynamic therapy. A mixed cyclotetramerisation of a 3,6-dialkylphthalonitrile with a second aromatic dinitrile forms so-called 3,:,1 phthalocyanines in which three of the benzenoid rings are substituted with two alkyl groups and the fourth is substituted differently. Appropriate substituents provide amphiphilic compounds that form well-ordered films by the Langmuir-Blodgett method and self-assembly techniques. Characterisation of the films using a variety of methods is discussed and applications described. Examples of 3,:,1 phthalocyanine-like macrocycles in which one of the benzenoid rings is replaced by a heterocycle extend the range of properties exhibited. These include broadband absorption in the near infrared and, in particular cases, edge-to-face dimerisation through coordination of a pyridine nitrogen to a zinc centre in a second macrocycle. The potential for using suitably functionalised 3,:,1 phthalocyanines as building blocks for more complex structures such as liquid crystalline main-chain polymeric phthalocyanines and phthalocyanino-dehydroannulenes is described. © 2002 The Japan Chemical Journal Forum and Wiley Periodicals, Inc., Chem Rec 2: 225,236, 2002: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.10028 [source] Scientific instrumentation for the 1.6 m New Solar Telescope in Big BearASTRONOMISCHE NACHRICHTEN, Issue 6 2010W. Cao Abstract The NST (New Solar Telescope), a 1.6 m clear aperture, off-axis telescope, is in its commissioning phase at Big Bear Solar Observatory (BBSO). It will be the most capable, largest aperture solar telescope in the US until the 4 m ATST (Advanced Technology Solar Telescope) comes on-line late in the next decade. The NST will be outfitted with state-of-the-art scientific instruments at the Nasmyth focus on the telescope floor and in the Coudé Lab beneath the telescope. At the Nasmyth focus, several filtergraphs already in routine operation have offered high spatial resolution photometry in TiO 706 nm, H, 656 nm, G-band 430 nm and the near infrared (NIR), with the aid of a correlation tracker and image reconstruction system. Also, a Cryogenic Infrared Spectrograph (CYRA) is being developed to supply high signal-to-noise-ratio spectrometry and polarimetry spanning 1.0 to 5.0 ,m. The Coudé Lab instrumentation will include Adaptive Optics (AO), InfraRed Imaging Magnetograph (IRIM), Visible Imaging Magnetograph (VIM), and Fast Imaging Solar Spectrograph (FISS). A 308 sub-aperture (349-actuator deformable mirror) AO system will enable nearly diffraction limited observations over the NST's principal operating wavelengths from 0.4 ,m through 1.7 ,m. IRIM and VIM are Fabry-Pérot based narrow-band tunable filters, which provide high resolution two-dimensional spectroscopic and polarimetric imaging in the NIR and visible respectively. FISS is a collaboration between BBSO and Seoul National University focussing on chromosphere dynamics. This paper reports the up-to-date progress on these instruments including an overview of each instrument and details of the current state of design, integration, calibration and setup/testing on the NST (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] In situ near infrared spectroscopy for analyte-specific monitoring of glucose and ammonium in streptomyces coelicolor fermentationsBIOTECHNOLOGY PROGRESS, Issue 1 2010Nanna Petersen Abstract There are many challenges associated with in situ collection of near infrared (NIR) spectra in a fermentation broth, particularly for highly aerated and agitated fermentations with filamentous organisms. In this study, antibiotic fermentation by the filamentous bacterium Streptomyces coelicolor was used as a model process. Partial least squares (PLS) regression models were calibrated for glucose and ammonium based on NIR spectra collected in situ. To ensure that the models were calibrated based on analyte-specific information, semisynthetic samples were used for model calibration in addition to data from standard batches. Thereby, part of the inherent correlation between the analytes could be eliminated. The set of semisynthetic samples were generated from fermentation broth from five separate fermentations to which different amounts of glucose, ammonium, and biomass were added. This method has previously been used off line but never before in situ. The use of semisynthetic samples along with validation on an independent batch provided a critical and realistic evaluation of analyte-specific models based on in situ NIR spectroscopy. The prediction of glucose was highly satisfactory resulting in a RMSEP of 1.1 g/L. The prediction of ammonium based on NIR spectra collected in situ was not satisfactory. A comparison with models calibrated based on NIR spectra collected off line suggested that this is caused by signal attenuation in the optical fibers in the region above 2,000 nm; a region which contains important absorption bands for ammonium. For improved predictions of ammonium in situ, it is suggested to focus efforts on enhancing the signal in that particular region. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source] | ||||||||||||||||||||||