WorldWideScience

Sample records for situ pigment investigation

  1. Portable XRF as a valuable device for preliminary in situ pigment investigation of wooden inventory in the Trski Vrh Church in Croatia

    International Nuclear Information System (INIS)

    Desnica, V.; Skaric, K.; Mudronja, D.; Pavlicic, M.; Peranic, I.; Jembrih-Simbuerger, D.; Schreiner, M.; Fazinic, S.; Jaksic, M.

    2008-01-01

    The aim of this work was the investigation of pigments from the painted wooden inventory of the pilgrimage church of Saint Mary of Jerusalem in Trski Vrh - one of the most beautiful late-baroque sacral ensembles in Croatia. Being an object of high relevance for the national cultural heritage, an extensive research on the wooden polychromy was undertaken in order to work out a proposal for a conservation treatment. It consists mainly of two painted and gilded layers (the original one from the 18th century and a later one from 1903), partly overpainted during periodic conservation treatments in the past. The approach was to carry out extensive preliminary in situ pigment investigations using a portable XRF (X-ray fluorescence) device, and only the problems not resolved by this method on site were further analyzed using sophisticated laboratory equipment. Therefore, the XRF results acted as a valuable guideline for subsequent targeted sampling actions, thus minimizing the sampling damage. Important questions not answered by XRF (identification of organic pigments, ultramarine, etc.) were subsequently resolved using additional ex situ laboratory methods, primarily μ-PIXE (particle-induced X-ray emission) at the nuclear microprobe of the Rudjer Boskovic accelerator facility as well as μ-Raman spectroscopy at the Institute of the Academy of Fine Arts in Vienna. It is shown that by the combination of these often complementary methods a thorough characterization of each pigment can be obtained, allowing for a proper strategy of the conservation treatment. (orig.)

  2. Analysis of basidiomycete pigments in situ by Raman spectroscopy.

    Science.gov (United States)

    Tauber, James P; Matthäus, Christian; Lenz, Claudius; Hoffmeister, Dirk; Popp, Jürgen

    2018-02-07

    Basidiomycetes, that is, mushroom-type fungi, are known to produce pigments in response to environmental impacts. As antioxidants with a high level of unsaturation, these compounds can neutralize highly oxidative species. In the event of close contact with other microbes, the enzymatically controlled pigment production is triggered and pigment secretion is generated at the interaction zone. The identification and analysis of these pigments is important to understand the defense mechanism of fungi, which is essential to counteract an uncontrolled spread of harmful species. Usually, a detailed analysis of the pigments is time consuming as it depends on laborious sample preparation and isolation procedures. Furthermore, the applied protocols often influence the chemical integrity of the compound of interest. A possibility to noninvasively investigate the pigmentation is Raman microspectroscopy. The methodology has the potential to analyze the chemical composition of the sample spatially resolved at the interaction zone. After the acquisition of a representative spectroscopic library, the pigment production by basidiomycetes was monitored for during response to different fungi and bacteria. The presented results describe a very efficient noninvasive way of pigment analysis which can be applied with minimal sample preparation. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Near-infrared luminescence of cadmium pigments: in situ identification and mapping in paintings.

    Science.gov (United States)

    Thoury, Mathieu; Delaney, John K; Rie, E René de la; Palmer, Michael; Morales, Kathryn; Krueger, Jay

    2011-08-01

    A comprehensive study of the luminescence properties of cadmium pigments was undertaken to determine whether these properties could be used for in situ identification and mapping of the pigments in paintings. Cadmium pigments are semiconductors that show band edge luminescence in the visible range and deep trap luminescence in the red/infrared range. Emission maxima, quantum yields, and excitation spectra from the band edge and deep trap emissions were studied for sixty commercial cadmium pigments that span the color range from yellow to red (reflectance transition 470 to 660 nm). For paints containing cadmium pigments, luminescence from deep traps was more readily observable than that from the band edge, although the yield varied widely from zero to around 4.5%. Optimal excitation for emission is found to be in the visible for both pigments in powder form and mixed with a medium. The maxima of the deep trap emission shift with the band gap energy, providing a potentially useful way to assign pigment type even when used in pigment mixtures. The usefulness of the results of the study on mockups was demonstrated by the mapping of cadmium pigments of different hues with the aid of calibrated luminescence imaging spectroscopy in a painting by Edward Steichen, entitled Study for 'Le Tournesol' (1920). Analysis of the luminescence image cube reveals at least six unique spectral components, associated with emission from white pigments, paint binder, and cadmium red and yellow pigments. The results were compared with those from X-ray fluorescence spectrometry (XRF) and fiber-optic reflection spectroscopy (FORS) and the results obtained on paint samples containing cadmium pigments. These results show that, when present, the emission from traps can be used as an analytical tool to identify cadmium pigments, to distinguish among cadmium sulfide, cadmium zinc sulfide, and cadmium sulfoselenide, and to map cadmium pigments, even in mixtures.

  4. In-situ spectroscopic analysis of the traditional dyeing pigment Turkey red inside textile matrix

    Science.gov (United States)

    Meyer, M.; Huthwelker, T.; Borca, C. N.; Meßlinger, K.; Bieber, M.; Fink, R. H.; Späth, A.

    2018-03-01

    Turkey red is a traditional pigment for textile dyeing and its use has been proven for various cultures within the last three millennia. The pigment is a dye-mordant complex consisting of Al and an extract from R. tinctorum that contains mainly the anthraquinone derivative alizarin. The chemical structure of the complex has been analyzed by various spectroscopic and crystallographic techniques for extractions from textiles or directly in solution. We present an in-situ study of Turkey red by means of μ-XRF mapping and NEXAFS spectroscopy on textile fibres dyed according to a traditional process to gain insight into the coordination chemistry of the pigment in realistic matrix. We find an octahedral coordination of Al that corresponds well to the commonly accepted structure of the Al alizarin complex derived from ex-situ studies.

  5. Spatial variability of phytoplankton pigment distributions in the Subtropical South Pacific Ocean: comparison between in situ and predicted data

    Directory of Open Access Journals (Sweden)

    J. Ras

    2008-03-01

    Full Text Available In the frame of the BIOSOPE cruise in 2004, the spatial distribution and structure of phytoplankton pigments was investigated along a transect crossing the ultra-oligotrophic South Pacific Subtropical Gyre (SPSG between the Marquesas Archipelago (141° W–8° S and the Chilean upwelling (73° W–34° S. A High Performance Liquid Chromatography (HPLC method was improved in order to be able to accurately quantify pigments over such a large range of trophic levels, and especially from strongly oligotrophic conditions. Seven diagnostic pigments were associated to three phytoplankton size classes (pico-, nano and microphytoplankton. The total chlorophyll-α concentrations [TChlα] in surface waters were the lowest measured in the centre of the gyre, reaching 0.017 mg m−3. Pigment concentrations at the Deep Chlorophyll Maximum (DCM were generally 10 fold the surface values. Results were compared to predictions from a global parameterisation based on remotely sensed surface [TChlα]. The agreement between the in situ and predicted data for such contrasting phytoplankton assemblages was generally good: throughout the oligotrophic gyre system, picophytoplankton (prochlorophytes and cyanophytes and nanophytoplankton were the dominant classes. Relative bacteriochlorophyll-α concentrations varied around 2%. The transition zone between the Marquesas and the SPSG was also well predicted by the model. However, some regional characteristics have been observed where measured and modelled data differ. Amongst these features is the extreme depth of the DCM (180 m towards the centre of the gyre, the presence of a deep nanoflagellate population beneath the DCM or the presence of a prochlorophyte-enriched population in the formation area of the high salinity South Pacific Tropical Water. A coastal site sampled in the eutrophic upwelling zone, characterised by recently upwelled water, was significantly and unusually enriched in picoeucaryotes, in

  6. Spectrometric Investigation of Pigments and Substrata in Wood Paintings

    Science.gov (United States)

    Chiojdeanu, Catalina; Vasilescu, Angela; Manea, Mihaela; Constantin, Florin; Saliba, James

    2014-02-01

    A polychrome and gilded wooden artifact was found, in a heavily deteriorated state, in the stores of the Mdina Cathedral Museum, Malta. The object represents two zoomorphic angels holding a coat of arms. Stylistically, the artifact matches with parts of a late 16th century Organ balcony, currently exhibited at the same Museum. The present study aims to establish whether or not the newly recovered artifact might have formed part of the balcony ensemble by means of material identification techniques. The combined use of XRF, FT-IR and FT-Raman spectroscopy ensure a detailed characterization of the material used. In the case of pigments, for both artifacts the blue pigment was smalt, while cinnabar was used for red and flesh tones. The metallic decorative parts of the panels are gilded, confirmed by the presence of Au peaks in the X-ray spectra. The supporting structure of both artifacts was manufactured from poplar wood.

  7. Spectrometric investigation of pigments and substrata in wood paintings

    International Nuclear Information System (INIS)

    Chiojdeanu, C.; Vasilescu, A.; Manea, M.; Constantin, F.; Saliba, James

    2014-01-01

    A polychrome and gilded wooden artifact was found, in a heavily deteriorated state, in the stores of the Mdina Cathedral Museum, Malta. The object represents two zoomorphic angels holding a coat of arms. Stylistically, the artifact matches with parts of a late 16th century Organ balcony, currently exhibited at the same Museum. The present study aims to establish whether or not the newly recovered artifact might have formed part of the balcony ensemble by means of material identification techniques. The combined use of XRF, FT-IR and FT-Raman spectroscopy ensure a detailed characterization of the material used. In the case of pigments, for both artifacts the blue pigment was smalt, while cinnabar was used for red and flesh tones. The metallic decorative parts of the panels are gilded, confirmed by the presence of Au peaks in the X-ray spectra. The supporting structure of both artifacts was manufactured from poplar wood. (author)

  8. A non invasive method to detect stratigraphy, thicknesses and pigment concentration of pictorial multilayers based on EDXRF and vis-RS: in situ applications

    International Nuclear Information System (INIS)

    Bonizzoni, L.; Caglio, S.; Galli, A.; Poldi, G.

    2008-01-01

    Energy dispersive XRF analysis (EDXRF) in association with visible reflectance spectroscopy (vis-RS), both achieved by portable instruments, can be successfully applied, in a wide range of cases, to investigate wood or canvas paintings in order to obtain some stratigraphic information with non-invasive techniques. The specific aim of this work is to use them as quantitative tools: EDXRF to reconstruct the thicknesses of the detected layers, vis-RS to report pigment concentration in the uppermost layer. We present here some in situ analyses of famous paintings by Andrea Mantegna and Giovanni Bellini, compared with stratigraphic optical microscopy observations on cross sections. Advantages and limits are pointed out. (orig.)

  9. In situ investigations at Avery Island

    International Nuclear Information System (INIS)

    Van Sambeek, L.L.

    1980-01-01

    Descriptions and representative data are given for the in situ investigations being performed in the Avery Island Mine. Sufficient detail is presented such that investigators can judge whether any of the studies being performed would be valuable for their numerical modeling exercises. The basic investigations being performed include heater tests, brine migration experiments, and flatjack tests. The heater tests consist of the emplacement of single simulated waste canisters with different power levels. The bulk thermal and mechanical response is measured of the salt surrounding the emplacement. The brine migration studies involve the measurement of moisture inflow into heated boreholes. The flatjack studies are an investigation of the deformation of the borehole when subjected to controlled boundary conditions of stress and temperature

  10. In situ characterization of the black pigment from parietal art of the Rouffignac Cave with a portable XRF system

    International Nuclear Information System (INIS)

    Sanoit, J. de; Chambellan, D.; Plassard, F.

    2005-01-01

    The Rouffignac cave in Dordogne (France) is a palaeolithic site which contains, among others, an important patrimony of cave art realized with black pigment (mammoths, bisons, woolly rhinoceros, horses, ibexes). Although no direct dating has ever been realized to date, the graphic works of this cave are generally connected to the Magdalenian age by cross-dating (stylistic comparison). For the first time, in situ non destructive analyses of this pigment were able to be made due to the use of a portable XRF system (X-Ray Fluorescence). The experimental set-up is mainly constituted with a small X-ray generator (Bullet TM 40 kV, Moxtek), a SDD detector (silicon drift detector, Rontec 1102) cooled by a Peltier cryostat and an optical system, the whole being connected to a portable system for acquisition of spectrometric data. The experimental spectra obtained on the three rhinoceros frieze, the horse over the flint nodule, the ten mammoths frieze and some animals of the Grand Plafond showed a systematic presence of manganese in all figures. This hypothesis had been already suggested by Graziosi in 1956 in the review 'La Nature' after a destructive analysis of a sample taken on one of the horses of the Grand Plafond. A Monte-Carlo simulation allowed a first quantitative approach in the analysis of the black pigment of the drawings. We can assess that the used manganese ore does not only result from a unique source because variable ratios of manganese, barium and iron were probed in the black pigment. None of the studied drawing was executed exclusively with black charcoal that would have made the selection of a sample suitable for radiocarbon dating less complicated. Additional non destructive in situ analysis using a portable PIXE set-up (Particles Induced X-ray Emission) equipped with a 210 Po as radiation source can be foreseen to allow the detection of elements with atomic numbers (Z) between 11 and 16 in the first layers of the black pigment, there where the XRF

  11. Neutron-induced autoradiography used in the investigation of modern pigments in paintings of known composition

    International Nuclear Information System (INIS)

    Aderhold, H.C.; Taft, W.S.

    1992-01-01

    Neutron-Induced Autoradiography is an effective analytical technique for mapping the location of a number of specified pigments in paintings. Most paintings which have been examined through neutron-induced autoradiography to date were painted prior to the introduction of the most common of modern pigments. By understanding die nuclear properties of these pigments, as revealed by this technique, a more informed analysis of modem paintings may result This investigation is part of an ongoing program to develop case studies for presentation to an undergraduate class at Cornell University, 'Art, Isotopes and Analysis'. We have found that this technique is a graphic and effective method of presenting nuclear reactions and radioactivity to non-specialists. Sample paintings are produced using pigments of known composition. A sequence of discreet layers, each a separate image, is documented in order to establish a reference for accurately interpreting the autoradiographs. The painting is then activated in the Cornell TRIGA reactor and a series of autoradiographs produced Gamma spectra taken before and after each film exposure gives us detailed information on which radioisotopes (and therefore, which pigments), are active. (author)

  12. To Investigate the Absorption, Dynamic Contact Angle and Printability Effects of Synthetic Zeolite Pigments in an Inkjet Receptive Coating

    Science.gov (United States)

    Jalindre, Swaraj Sunil

    Ink absorption performance in inkjet receptive coatings containing synthetic zeolite pigments was studied. Coating pigment pore and particle size distribution are the key parameters that influence in modifying media surface properties, thus affecting the rate of ink penetration and drying time (Scholkopf, et al. 2004). The primary objective of this study was: (1) to investigate the synthetic zeolite pigment effects on inkjet ink absorption, dynamic contact angle and printability, and (2) to evaluate these novel synthetic zeolite pigments in replacing the fumed silica pigments in conventional inkjet receptive coatings. In this research study, single pigment coating formulations (in equal P:B ratio) were prepared using microporous synthetic zeolite pigments (5A, Organophilic and 13X) and polyvinyl alcohol (PVOH) binder. The laboratory-coated samples were characterized for absorption, air permeance, roughness, drying time, wettability and print fidelity. Based on the rheological data, it was found that the synthetic zeolite formulated coatings depicted a Newtonian flow behavior at low shear; while the industry accepted fumed silica based coatings displayed a characteristically high pseudoplastic flow behavior. Our coated samples generated using microporous synthetic zeolite pigments produced low absorption, reduced wettability and accelerated ink drying characteristics. These characteristics were caused due to the synthetic zeolite pigments, which resulted in relatively closed surface structure coated samples. The research suggested that no single selected synthetic zeolite coating performed better than the conventional fumed silica based coatings. Experimental data also showed that there was no apparent relationship between synthetic zeolite pigment pore sizes and inkjet ink absorption. For future research, above coated samples should be evaluated for pore size distribution using Mercury Porosimeter, which quantifies surface porosity of coated samples. This presented

  13. The Bone Black Pigment Identification by Noninvasive, In Situ Infrared Reflection Spectroscopy

    Directory of Open Access Journals (Sweden)

    Alessia Daveri

    2018-01-01

    Full Text Available Two real case studies, an oil painting on woven paper and a cycle of mural paintings, have been presented to validate the use of infrared reflection spectroscopy as suitable technique for the identification of bone black pigment. By the use of the sharp weak band at 2013 cm−1, it has been possible to distinguish animal carbon-based blacks by a noninvasive method. Finally, an attempt for an eventual assignment for the widely used sharp band at 2013 cm−1 is discussed.

  14. Structural investigations on betacyanin pigments by LC NMR and 2D NMR spectroscopy.

    Science.gov (United States)

    Stintzing, Florian C; Conrad, Jürgen; Klaiber, Iris; Beifuss, Uwe; Carle, Reinhold

    2004-02-01

    Four betacyanin pigments were analysed by LC NMR and subjected to extensive NMR characterisation after isolation. Previously, low pH values were applied for NMR investigations of betalains resulting in rapid degradation of the purified substances thus preventing extensive NMR studies. Consequently, up to now only one single (13)C NMR spectrum of a betalain pigment, namely that of neobetanin (=14,15-dehydrobetanin), was available. Because of its sufficient stability under highly acidic conditions otherwise detrimental for betacyanins, this pigment remained an exemption. Since betalains are most stable in the pH range of 5-7, a new solvent system has been developed allowing improved data acquisition through improved pigment stability at near neutral pH. Thus, not only (1)H, but for the first time also partial (13)C data of betanin, isobetanin, phyllocactin and hylocerenin isolated from red-purple pitaya [Hylocereus polyrhizus (Weber) Britton & Rose, Cactaceae] could be indirectly obtained by gHSQC- and gHMQC-NMR experiments.

  15. Analytical Investigation Of Pigments, Ground Layer And Media Of Cartonnage Fragments From Greek Roman Period

    Science.gov (United States)

    Afifi, Hala. A. M.

    Some cartonnage fragments from Hawara, Fayoum Excavation were examined to identify pigments, media and grounds. It belonged to the Greek-Roman period. They were studied by X-ray diffraction (XRD), Energy dispersive X ray analysis (EDS) equipped with Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). These techniques were used to identify the composition and morphology of grounds, nature of pigments and media used in cartonnage fragments. The coarse ground layer was composed of calcite and traces of quartz. The fine ground layer used under the pigments directly was composed of calcite only. Carbon black was used as black pigment while lead oxide as red pigment, showing the influence of Roman and Greek pigments on Egyptian art in these later periods. Blue colorant was identified as cuprorivaite and yellow pigment was goethite. Animal glue was used in the four pigments as medium colored.

  16. Experimental investigation of in situ cleanable HEPA filters

    International Nuclear Information System (INIS)

    Adamson, D.J.

    2000-01-01

    Savannah River Technology Center (SRTC), High Level Waste Division, Tanks Focus Area, and the Federal Energy Technology Center (FETC) have been investigating high efficiency particulate air (HEPA) filters which can be regenerated or cleaned in situ as an alternative to conventional disposable HEPA filters. This technical report documents concerns pertaining to conventional HEPA filters

  17. Experimental investigation of in situ cleanable HEPA filter

    International Nuclear Information System (INIS)

    Adamson, D.J.

    1999-01-01

    The Westinghouse Savannah River Company located at the Savannah River Site (SRS) in Aiken, South Carolina is currently testing the feasibility of developing an in situ cleanable high efficiency particulate air (HEPA) filter system. Sintered metal filters are being tested for regenerability or cleanability in simulated conditions found in a high level waste (HLW) tank ventilation system. The filters are being challenged using materials found in HLW tanks. HLW simulated salt, HLW simulated sludge and South Carolina road dust. Various cleaning solutions have been used to clean the filters in situ. The tanks are equipped with a ventilation system to maintain the tank contents at negative pressure to prevent the release of radioactive material to the environment. This system is equipped with conventional disposable glass-fiber HEPA filter cartridges. Removal and disposal of these filters is not only costly, but subjects site personnel to radiation exposure and possible contamination. A test apparatus was designed to simulate the ventilation system of a HLW tank with an in situ cleaning system. Test results indicate that the Mott sintered metal HEPA filter is suitable as an in situ cleanable or regenerable HEPA filter. Data indicates that high humidity or water did not effect the filter performance and the sintered metal HEPA filter was easily cleaned numerous times back to new filter performance by an in situ spray system. The test apparatus allows the cleaning of the soiled HEPA filters to be accomplished without removing the filters from process. This innovative system would eliminate personnel radiation exposure associated with removal of contaminated filters and the high costs of filter replacement and disposal. The results of these investigations indicate that an in situ cleanable HEPA filter system for radioactive and commercial use could be developed and manufactured

  18. Patterns of coccolithophore pigment change under global acidification conditions based on in-situ observations at BATS site between July 1990-Dec 2008

    Science.gov (United States)

    Lv, Jianhai; Kuang, Yaoqiu; Zhao, Hui; Andersson, Andreas

    2017-06-01

    Coccolith production is an important part of the biogenic carbon cycle as the largest source of calcium carbonate on earth, accounting for about 75% of the deposition of carbon on the sea floor. Recent studies based on laboratory experiment results indicated that increasing anthropogenic CO2 in the atmosphere triggered global ocean acidification leading to a decrease of calcite or aragonite saturation and calcium carbonate, and to decreasing efficiency of carbon export/pumping to deep layers. In the present study, we analyzed about 20 years of field observations of coccolithophore pigment, dissolved inorganic carbon (DIC), nutrients, and temperatures from the Bermuda Atlantic Time-series Study (BATS) site and satellite remote sensing to investigate the variable tendency of the coccolithophore pigment, and to evaluate the influence of ocean acidification on coccolithophore biomass. The results indicated that there was a generally increasing tendency of coccolithophore pigment, coupled with increasing bicarbonate concentrations or decreasing carbonate ion concentration. The change of coccolithophore pigment was also closely associated with pH, nutrients, mixed layer depth (MLD), and temperature. Correlation analyses between coccolithophores and abiotic parameter imply that coccoliths production or coccolithophore pigment has increased with increasing acidification in the recent 20 years.

  19. Investigating the influence of pH, temperature and agitation speed on yellow pigment production by Penicillium aculeatum ATCC 10409.

    Science.gov (United States)

    Afshari, Majid; Shahidi, Fakhri; Mortazavi, Seyed Ali; Tabatabai, Farideh; Es'haghi, Zarin

    2015-01-01

    In this study, the combined effect of pH, temperature and agitation speed on yellow pigment production and mycelial growth of Penicillium aculeatum ATCC 10409 was investigated in whey media. Different pH levels (5, 6.5 and 8), temperatures (25, 30 and 35°C) and agitation speed levels (100 and 150 rpm) were tested to determine the best conditions to produce a fungal yellow pigment under submerged fermentation. The best production of yellow pigment (1.38 g/L) was obtained with a pH value of 6.5, a temperature of 30°C and an agitation speed of 150 rpm. In contrast, the maximal biomass concentration (11.12 g/L) was obtained at pH value of 8, a temperature of 30°C and an agitation speed of 100 rpm. These results demonstrated that biomass and yellow pigment production were not directly associated. The identification of the structure of unknown P. aculeatum yellow pigment was detected using UV absorption spectrum and FT-IR spectroscopy.

  20. An investigation of multispectral imaging for the mapping of pigments in paintings

    Science.gov (United States)

    Zhao, Yonghui; Berns, Roy S.; Taplin, Lawrence A.; Coddington, James

    2008-02-01

    Compared with colorimetric imaging, multispectral imaging has the advantage of retrieving spectral reflectance factor of each pixel of a painting. Using this spectral information, pigment mapping is concerned with decomposing the spectrum into its constituent pigments and their relative contributions. The output of pigment mapping is a series of spatial concentration maps of the pigments comprising the painting. This approach was used to study Vincent van Gogh's The Starry Night. The artist's palette was approximated using ten oil pigments, selected from a large database of pigments used in oil paintings and a priori analytical research on one of his self portraits, executed during the same time period. The pigment mapping was based on single-constant Kubelka-Munk theory. It was found that the region of blue sky where the stars were located contained, predominantly, ultramarine blue while the swirling sky and region surrounding the moon contained, predominantly, cobalt blue. Emerald green, used in light bluish-green brushstrokes surrounding the moon, was not used to create the dark green in the cypresses. A measurement of lead white from Georges Seurat's La Grande Jatte was used as the white when mapping The Starry Night. The absorption and scattering properties of this white were replaced with a modern dispersion of lead white in linseed oil and used to simulate the painting's appearance before the natural darkening and yellowing of lead white oil paint. Pigment mapping based on spectral imaging was found to be a viable and practical approach for analyzing pigment composition, providing new insight into an artist's working method, the possibility for aiding in restorative inpainting, and lighting design.

  1. Optical properties of photoreceptor and retinal pigment epithelium cells investigated with adaptive optics optical coherence tomography

    Science.gov (United States)

    Liu, Zhuolin

    Human vision starts when photoreceptors collect and respond to light. Photoreceptors do not function in isolation though, but share close interdependence with neighboring photoreceptors and underlying retinal pigment epithelium (RPE) cells. These cellular interactions are essential for normal function of the photoreceptor-RPE complex, but methods to assess these in the living human eye are limited. One approach that has gained increased promise is high-resolution retinal imaging that has undergone tremendous technological advances over the last two decades to probe the living retina at the cellular level. Pivotal in these advances has been adaptive optics (AO) and optical coherence tomography (OCT) that together allow unprecedented spatial resolution of retinal structures in all three dimensions. Using these high-resolution systems, cone photoreceptor are now routinely imaged in healthy and diseased retina enabling fundamental structural properties of cones to be studied such as cell spacing, packing arrangement, and alignment. Other important cell properties, however, have remained elusive to investigation as even better imaging performance is required and thus has resulted in an incomplete understanding of how cells in the photoreceptor-RPE complex interact with light. To address this technical bottleneck, we expanded the imaging capability of AO-OCT to detect and quantify more accurately and completely the optical properties of cone photoreceptor and RPE cells at the cellular level in the living human retina. The first objective of this thesis was development of a new AO-OCT method that is more precise and sensitive, thus enabling a more detailed view of the 3D optical signature of the photoreceptor-RPE complex than was previously possible (Chapter 2). Using this new system, the second objective was quantifying the waveguide properties of individual cone photoreceptor inner and outer segments across the macula (Chapter 3). The third objective extended the AO

  2. Estimation of Phytoplankton Accessory Pigments From Hyperspectral Reflectance Spectra: Toward a Global Algorithm

    Science.gov (United States)

    Chase, A. P.; Boss, E.; Cetinić, I.; Slade, W.

    2017-12-01

    Phytoplankton community composition in the ocean is complex and highly variable over a wide range of space and time scales. Able to cover these scales, remote-sensing reflectance spectra can be measured both by satellite and by in situ radiometers. The spectral shape of reflectance in the open ocean is influenced by the particles in the water, mainly phytoplankton and covarying nonalgal particles. We investigate the utility of in situ hyperspectral remote-sensing reflectance measurements to detect phytoplankton pigments by using an inversion algorithm that defines phytoplankton pigment absorption as a sum of Gaussian functions. The inverted amplitudes of the Gaussian functions representing pigment absorption are compared to coincident High Performance Liquid Chromatography measurements of pigment concentration. We determined strong predictive capability for chlorophylls a, b, c1+c2, and the photoprotective carotenoids. We also tested the estimation of pigment concentrations from reflectance-derived chlorophyll a using global relationships of covariation between chlorophyll a and the accessory pigments. We found similar errors in pigment estimation based on the relationships of covariation versus the inversion algorithm. An investigation of spectral residuals in reflectance data after removal of chlorophyll-based average absorption spectra showed no strong relationship between spectral residuals and pigments. Ultimately, we are able to estimate concentrations of three chlorophylls and the photoprotective carotenoid pigments, noting that further work is necessary to address the challenge of extracting information from hyperspectral reflectance beyond the information that can be determined from chlorophyll a and its covariation with other pigments.

  3. In situ vitrification program treatability investigation progress report

    International Nuclear Information System (INIS)

    Arrenholz, D.A.

    1991-02-01

    This document presents a summary of the efforts conducted under the in situ vitrification treatability study during the period from its initiation in FY-88 until FY-90. In situ vitrification is a thermal treatment process that uses electrical power to convert contaminated soils into a chemically inert and stable glass and crystalline product. Contaminants present in the soil are either incorporated into the product or are pyrolyzed during treatment. The treatability study being conducted at the Idaho National Engineering Laboratory by EG ampersand G Idaho is directed at examining the specific applicability of the in situ vitrification process to buried wastes contaminated with transuranic radionuclides and other contaminants found at the Subsurface Disposal Area of the Radioactive Waste Management Complex. This treatability study consists of a variety of tasks, including engineering tests, field tests, vitrified product evaluation, and analytical models of the in situ vitrification process. 6 refs., 4 figs., 3 tabs

  4. In situ x-ray diffraction and in situ x-ray absorption spectroscopy for investigation of intercalation batteries

    International Nuclear Information System (INIS)

    Levy-Clement, C.; Mondoloni, C.; Godart, C.; Cortes, R.

    1991-01-01

    This paper presents applications of in situ X-ray diffraction and absorption techniques to the study of H + /MnO 2 alkaline batteries. The two complementary in situ techniques are described. Investigation of the electrochemical insertion and deinsertion of H + has been made through its influence on the evolution of the crystallographic structure of γ-MnO 2 , while investigation of the transfer of e - has been undertaken through the variation of the oxidation state of the manganese during the discharging and charging process of a battery. New insights in the understanding of the mechanisms of proton insertion and charge transfer into γ-MnO 2 are discussed

  5. Application of instrumental neutron activation analysis in investigation of pigments from historic paintings

    International Nuclear Information System (INIS)

    Stverak, B.; Tluchor, D.; Kokta, L.; Dryak, P.; Rowinska, L.; Walis, L.; Vosatka, A.

    1985-01-01

    Neutron activation analysis was used in determining the composition of used pigments, their age and origin. Microsamples from paintings with a weight of less than 10 -7 kg were taken with a hollow needle, irradiated in quartz ampoules for 20 hours in a reactor with a density of thermal neutrons of 10 13 cm -2 .s -1 and then in different configurations measured with a Ge(Li) detector. From the amount of obtained data (various paintings, different colours) a data bank will be established enabling speedy comparative evaluations. As an example the problem of the excellent white in Rubens' paintings is dealt with and the dating is discussed of the early beginnings of the use of zinc white in Guardi's paintings. (M.D.)

  6. In-Situ Investigation of Local Boundary Migration During Recrystallization

    DEFF Research Database (Denmark)

    Zhang, Yubin; Godfrey, Andy; Juul Jensen, Dorte

    2014-01-01

    A combination of electron channeling contrast (ECC) and electron backscatter diffraction pattern (EBSP) techniques has been used to follow in situ the migration during annealing at 323 K (50 A degrees C) of a recrystallizing boundary through the deformed matrix of high-purity aluminum rolled to 8...

  7. In situ vitrification program treatability investigation progress report

    International Nuclear Information System (INIS)

    Arrenholz, D.A.

    1990-12-01

    This document presents a summary of the efforts conducted under the in situ vitrification treatability study during the period from its initiation in FY-88 until FY-90. In situ vitrification is a thermal treatment process that uses electrical power to convert contaminated soils into a chemically inert and stable glass and crystalline product. Contaminants present in the soil are either incorporated into the product or are pyrolyzed during treatment. The treatability study being conducted at the Idaho National Engineering Laboratory by EG ampersand G Idaho is directed at examining the specific applicability of the in situ vitrification process to buried wastes contaminated with transuranic radionuclides and other contaminants found at the Subsurface Disposal Area of the Radioactive Waste Management Complex. This treatability study consists of a variety of tasks, including engineering tests, field tests, vitrified product evaluation, and analytical models of the ISV process. The data collected in the course of these efforts will address the nine criteria set forth in the Comprehensive Environmental Response, Compensation, and Liability Act, which will be used to identify and select specific technologies to be used in the remediation of the buried wastes at the Subsurface Disposal Area. 6 refs., 4 figs., 3 tabs

  8. Characterization of Maize Grains with Different Pigmentation Investigated by Photoacoustic Spectroscopy

    Science.gov (United States)

    Rico Molina, R.; Hernández Aguilar, C.; Dominguez Pacheco, A.; Cruz-Orea, A.; López Bonilla, J. L.

    2014-10-01

    A knowledge of grains' optical parameters is of great relevance in the maize grain technology practice. Such parameters provide information about its absorption and reflectance, which in turn is related to its color. In the dough and tortilla industries, it is important to characterize this attribute of the corn kernel, as it is one of the attributes that directly affects the quality of the food product. Thus, it is important to have techniques that contribute to the characterization of this raw material. It is traditionally characterized by conventional methods, which usually destroy the grain and involve a laborious preparation of material plus they are expensive. The objective of this study was to determine the optical absorption coefficient for maize grains ( Zea mays L.) with different pigmentations by means of photoacoustic spectroscopy (PAS). The genotype A had bluish coloration and genotype B had yellowish coloration. In addition, the photoacoustic signal obtained by two methods was analyzed mathematically: the standard deviation and the first derivative; both results were compared (Fig. 1). In combination with mathematical analysis, PAS may be considered as a potential diagnostic tool for the characterization of the grains. [Figure not available: see fulltext.

  9. Investigation of Chemical Bonding in In Situ Cryocrystallized Organometallic Liquids.

    Science.gov (United States)

    Sirohiwal, Abhishek; Hathwar, Venkatesha R; Dey, Dhananjay; Chopra, Deepak

    2017-10-19

    This Communication presents the crystal structure of the organometallic complexes (η 4 -1,3-cyclohexadiene) iron tricarbonyl (I) and (methyl cyclopentadienyl) manganese tricarbonyl (II) which are both liquid at room temperature. The crystal structures were determined using a state-of-the-art in situ cryocrystallization technique. The bonding features were elucidated using topological analysis of charge density in the framework of quantum theory of atoms in molecules (QTAIM) and theoretical charge density analysis (multipolar refinement), to decipher the metal-carbonyl, metal-olefin and metal-carbocyclic ligand interactions in these complexes. Complex I displayed a simultaneous interplay of a "synergic effect" (σ-donation and π-back-bonding in the metal and an end-on coordinated carbonyl interaction) as well as consistency with the Dewar-Chatt-Duncanson (DCD) model (metal and side-on coordinated π-ligand interactions). © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. A multi-analytical investigation of semi-conductor pigments with time-resolved spectroscopy and imaging

    Science.gov (United States)

    Nevin, A.; Cesaratto, A.; D'Andrea, C.; Valentini, Gianluca; Comelli, D.

    2013-05-01

    We present the non-invasive study of historical and modern Zn- and Cd-based pigments with time-resolved fluorescence spectroscopy, fluorescence multispectral imaging and fluorescence lifetime imaging (FLIM). Zinc oxide and Zinc sulphide are semiconductors which have been used as white pigments in paintings, and the luminescence of these pigments from trapped states is strongly dependent on the presence of impurities and crystal defects. Cadmium sulphoselenide pigments vary in hue from yellow to deep red based on their composition, and are another class of semiconductor pigments which emit both in the visible and the near infrared. The Fluorescence lifetime of historical and modern pigments has been measured using both an Optical Multichannel Analyser (OMA) coupled with a Nd:YAG nslaser, and a streak camera coupled with a ps-laser for spectrally-resolved fluorescence lifetime measurements. For Znbased pigments we have also employed Fluorescence Lifetime Imaging (FLIM) for the measurement of luminescence. A case study of FLIM applied to the analysis of the painting by Vincent Van Gogh on paper - "Les Bretonnes et le pardon de Pont-Aven" (1888) is presented. Through the integration of complementary, portable and non-invasive spectroscopic techniques, new insights into the optical properties of Zn- and Cd-based pigments have been gained which will inform future analysis of late 19th] and early 20th C. paintings.

  11. Differential sensitivity of pigmented and non-pigmented marine bacteria to metals and antibiotics

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, S.; Chandramohan, D.; LokaBharathi, P.A.

    The response of pigmented and non-pigmented marine bacteria to metals and antibiotics was investigated. The two groups responded differently to heavy metals and antibiotics. Pigmented bacteria were more resistant to metals. Among the metals, Zn...

  12. Magic angle spinning nuclear magnetic resonance apparatus and process for high-resolution in situ investigations

    Science.gov (United States)

    Hu, Jian Zhi; Sears, Jr., Jesse A.; Hoyt, David W.; Mehta, Hardeep S.; Peden, Charles H. F.

    2015-11-24

    A continuous-flow (CF) magic angle sample spinning (CF-MAS) NMR rotor and probe are described for investigating reaction dynamics, stable intermediates/transition states, and mechanisms of catalytic reactions in situ. The rotor includes a sample chamber of a flow-through design with a large sample volume that delivers a flow of reactants through a catalyst bed contained within the sample cell allowing in-situ investigations of reactants and products. Flow through the sample chamber improves diffusion of reactants and products through the catalyst. The large volume of the sample chamber enhances sensitivity permitting in situ .sup.13C CF-MAS studies at natural abundance.

  13. Near-field issues - Investigation of gas generation in situ

    International Nuclear Information System (INIS)

    Szanto, Zs.; Svingor, E.; Palcsu, L.; Mihaly, M.; Futo, I.

    2001-01-01

    The Puespoekszilagy Radioactive Waste Treatment and Disposal Facility is a typical near-surface engineered repository consisting of concrete vaults and wells for the disposal of spent sources. It has received waste from the Paks Nuclear Power Plant, from various laboratories and medical institutions, and, in particular, has been the site for the disposal of a number of spent sources. The safety of the repository has not been the subject of any comprehensive assessment, and does not have a permanent license. In 15th of March an A-type concrete vault was opened and the work was focused on issues that are critical for safety: characterisation of the behavior of the wastes, the degradation of the packaging, the chemical environment in the vaults, the chemical behavior of relevant radionuclides and the processes determining any migration of any radionuclide from the engineered system. Generic data can be used on rates of steel corrosion but an in situ measurement of head space gas composition and a detailed laboratory analysis give more relevant data. In addition to the radionuclide inventory a general estimate of the type of materials present (metals, halogenated and non-halogenated plastics and rubbers, cellulosic, building materials, organic, biological, flammable liquids, materials that may give rise to the generation of gas, etc.) was made and from these results in respect of radioactive gases, it seemed that the gases to be addressed should be 14 C-labelled methane and carbon dioxide, 3 H-labelled hydrogen, water vapor and methane, and 222 Rn. Before removing the protective lids sampling of the headspace gas of the vaults was performed by a special gas outlet system through the concrete cap. One of the cells (Code: A5) contained unconditioned radioactive waste disposed in polythene bags into the vault, without any backfilling. The other cell (Code: A6) was backfilled with cement, so there was a small gas field between the top of the surface of the backfill and the

  14. A quasi-monochromatic X-rays source for art painting pigments investigation

    International Nuclear Information System (INIS)

    Albertin, F.; Franconieri, A.; Gambaccini, M.; Petrucci, F.; Chiozzi, S.; Moro, D.

    2009-01-01

    Monochromatic X-ray sources can be used for several applications, like in medicine or in studying our cultural heritage. We are investigating imaging systems based on a tuneable energy band X-ray source, to obtain an element mapping of painting layers using the K-edge technique. The narrow energy band beams are obtained with conventional X-ray source via Bragg diffraction on a mosaic crystal; such an analysis has been performed at different diffraction angles, tuning the energy to investigate spectra of interest from the artistic point of view, like zinc and copper. In this paper the characteristics of the system in terms of fluence rate are reported, and first results of this technique on canvas samples and painting are presented. (orig.)

  15. Strategies and Technologies for In Situ Mineralogical Investigations on Mars

    Science.gov (United States)

    Marshall, J. R.; Bratton, C.; Koppel, L.; Hecht, M.; Metzger, E.

    1999-01-01

    Surface landers on Mars (Viking and Pathfinder) have not revealed satisfying answers to the mineralogy and lithology of the planet's surface. In part, this results from their prime directives: Viking focused on exobiology, Pathfinder focused on technology demonstration. The analytical instruments on board the landers made admirable attempts to extract the mineralogy and geology of Mars, as did countless modeling efforts after the missions. Here we suggest a framework for elucidating martian, or any other planetary geology, through an approach that defines (a) type of information required, (b) explorational strategy harmonious with acquisition of these data, (c) interpretation approach to the data, (d) compatible mission architecture, (e) instrumentation for interrogating rocks and soil. (a) Data required: The composition of a planet is ordered at scales ranging from molecules to minerals to rocks, and from geological units to provinces to planetary-scale systems. The largest ordering that in situ compositional instruments can attempt to interrogate is rock type "aggregate" information. This is what the geologist attempts to identify first. From this, mineralogy can be either directly seen or inferred. From mineralogy can be determined elemental abundances and perhaps the state of the compounds as being crystalline or amorphous. Knowledge of rock type and mineralogy is critical for elucidating geologic process. Mars landers acquired extremely valuable elemental data, but attempted to move from elements to aggregates, but this can only be done by making many assumptions and sometimes giant leaps of faith. Data we believe essential are elements, minerals, degree of ordering of compounds, and the aggregate or rock type that these materials compose. (b) Explorational strategy: A lander should function as a surrogate geologist. Of the total landscape, a geologist sees much, but gives detailed attention to an infinitesimally small amount of what is seen. To acquire

  16. In situ transmission electron microscopy investigations of electromigration in metals

    NARCIS (Netherlands)

    Kozlova, T.

    2015-01-01

    Electromigration is a process in which a metallic contact line is thinned by passing a current through it; which occurs due to a gradual displacement of atoms, ultimately leading to destruction of the wire. Despite the active investigations on electromigration for over fifty years, until now there

  17. Biomass Conversion in Ionic Liquids - in-situ Investigations

    DEFF Research Database (Denmark)

    Kunov-Kruse, Andreas Jonas

    . The fructose dehydration was investigated in both the presence and absence of CrCl3⋅6H2O. The partly dehydrated fructose intermediates were accumulated in the absence of chromium and water, leading to formation of humins. In the presence of CrCl3⋅6H2O the reaction was selective and the rates were 6-30 times...

  18. Strategies and Technologies for In Situ Mineralogical Investigations on Mars

    Science.gov (United States)

    Marshall, J. R.; Bratton, C.; Koppel, L.; Hecht, M.; Metzger, E.

    1999-01-01

    Surface landers on Mars (Viking and Pathfinder) have not revealed satisfying answers to the mineralogy and lithology of the planet's surface. In part, this results from their prime directives: Viking focused on exobiology, Pathfinder focused on technology demonstration. The analytical instruments on board the landers made admirable attempts to extract the mineralogy and geology of Mars, as did countless modeling efforts after the missions. Here we suggest a framework for elucidating martian, or any other planetary geology, through an approach that defines (a) type of information required, (b) explorational strategy harmonious with acquisition of these data, (c) interpretation approach to the data, (d) compatible mission architecture, (e) instrumentation for interrogating rocks and soil. (a) Data required: The composition of a planet is ordered at scales ranging from molecules to minerals to rocks, and from geological units to provinces to planetary-scale systems. The largest ordering that in situ compositional instruments can attempt to interrogate is rock type "aggregate" information. This is what the geologist attempts to identify first. From this, mineralogy can be either directly seen or inferred. From mineralogy can be determined elemental abundances and perhaps the state of the compounds as being crystalline or amorphous. Knowledge of rock type and mineralogy is critical for elucidating geologic process. Mars landers acquired extremely valuable elemental data, but attempted to move from elements to aggregates, but this can only be done by making many assumptions and sometimes giant leaps of faith. Data we believe essential are elements, minerals, degree of ordering of compounds, and the aggregate or rock type that these materials compose. (b) Explorational strategy: A lander should function as a surrogate geologist. Of the total landscape, a geologist sees much, but gives detailed attention to an infinitesimally small amount of what is seen. To acquire

  19. Exposure of Atlantic salmon parr (Salmo salar) to a combination of resin acids and a water soluble fraction of diesel fuel oil: A model to investigate the chemical causes of pigmented salmon syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Croce, B. [Scottish Office Agriculture, Environment, and Fisheries Dept., Aberdeen (United Kingdom). Marine Lab.]|[Scottish Environmental Protection Agency, Aberdeen (United Kingdom). North East River Purification Board; Stagg, R.M. [Scottish Office Agriculture, Environment, and Fisheries Dept., Aberdeen (United Kingdom). Marine Lab.

    1997-09-01

    Pigmented salmon syndrome is a pollutant-induced hemolytic anemia and hyperbilirubinemia. As part of an investigation of this condition, S2 Atlantic salmon parr (Salmo salar) were exposed to a diesel fuel oil, water soluble fraction (WSF) in combination with a mixture of three resin acids (isopimaric, dehydroabietic, and abietic acids) in a continuous-flow freshwater system. The total nominal concentrations of resin acids in the exposure tanks were 10, 50, and 100 {micro}g/L; the diesel WSF was generated in situ and provided a mean hydrocarbon concentration of 2.0 {+-} 0.1 mg/L (n = 12) during the 9-d exposure period. Exposure to the diesel WSF alone depressed liver bilirubin UDP-glucuronosyl transferase (UDPGT) activity and induced phenol UDPGT activity. Exposure to the diesel WSF in the absence or presence of resin acids induced liver cytochrome P4501A and increased the concentrations in the plasma of the enzymes lactate dehydrogenase, alkaline phosphatase, and glutamic oxaloacetic transaminase. The combined exposure to diesel WSF with either 50 or 100 {micro}g/L total resin acid caused significant elevations in the concentrations of bilirubin in the plasma and many of these fish had yellow pigmentation on the ventral surface and around the gill arches. The results demonstrate that exposure to combinations of two groups of contaminants can result in the manifestation of toxic effects not apparent from exposure to either of these chemicals in isolation.

  20. Ion transport in pigmentation.

    Science.gov (United States)

    Bellono, Nicholas W; Oancea, Elena V

    2014-12-01

    Skin melanocytes and ocular pigment cells contain specialized organelles called melanosomes, which are responsible for the synthesis of melanin, the major pigment in mammals. Defects in the complex mechanisms involved in melanin synthesis and regulation result in vision and pigmentation deficits, impaired development of the visual system, and increased susceptibility to skin and eye cancers. Ion transport across cellular membranes is critical for many biological processes, including pigmentation, but the molecular mechanisms by which it regulates melanin synthesis, storage, and transfer are not understood. In this review we first discuss ion channels and transporters that function at the plasma membrane of melanocytes; in the second part we consider ion transport across the membrane of intracellular organelles, with emphasis on melanosomes. We discuss recently characterized lysosomal and endosomal ion channels and transporters associated with pigmentation phenotypes. We then review the evidence for melanosomal channels and transporters critical for pigmentation, discussing potential molecular mechanisms mediating their function. The studies investigating ion transport in pigmentation physiology open new avenues for future research and could reveal novel molecular mechanisms underlying melanogenesis.

  1. Thyrotropin-releasing hormone selectively stimulates human hair follicle pigmentation.

    Science.gov (United States)

    Gáspár, Erzsébet; Nguyen-Thi, Kim T; Hardenbicker, Celine; Tiede, Stephan; Plate, Christian; Bodó, Eniko; Knuever, Jana; Funk, Wolfgang; Bíró, Tamás; Paus, Ralf

    2011-12-01

    In amphibians, thyrotropin-releasing hormone (TRH) stimulates skin melanophores by inducing secretion of α-melanocyte-stimulating hormone in the pituitary gland. However, it is unknown whether this tripeptide neurohormone exerts any direct effects on pigment cells, namely, on human melanocytes, under physiological conditions. Therefore, we have investigated whether TRH stimulates pigment production in organ-cultured human hair follicles (HFs), the epithelium of which expresses both TRH and its receptor, and/or in full-thickness human skin in situ. TRH stimulated melanin synthesis, tyrosinase transcription and activity, melanosome formation, melanocyte dendricity, gp100 immunoreactivity, and microphthalmia-associated transcription factor expression in human HFs in a pituitary gland-independent manner. TRH also stimulated proliferation, gp100 expression, tyrosinase activity, and dendricity of isolated human HF melanocytes. However, intraepidermal melanogenesis was unaffected. As TRH upregulated the intrafollicular production of "pituitary" neurohormones (proopiomelanocortin transcription and ACTH immunoreactivity) and as agouti-signaling protein counteracted TRH-induced HF pigmentation, these pigmentary TRH effects may be mediated in part by locally generated melanocortins and/or by MC-1 signaling. Our study introduces TRH as a novel, potent, selective, and evolutionarily highly conserved neuroendocrine factor controlling human pigmentation in situ. This physiologically relevant and melanocyte sub-population-specific neuroendocrine control of human pigmentation deserves clinical exploration, e.g., for preventing or reversing hair graying.

  2. In situ X-ray investigations of oxygen precipitation in semiconductor silicon; In-situ-Roentgenuntersuchungen der Sauerstoffpraezipitation in Halbleitersilizium

    Energy Technology Data Exchange (ETDEWEB)

    Grillenberger, Hannes

    2011-03-04

    The precipitation of oxygen in Czochralski grown semiconductor silicon is investigated in situ during thermal treatments up to 1000 C with high energy X-rays. All investigations are performed with a focusing Laue diffractometer. The parameters of the diffraction curve are the relative full width at half maximum (rFHWM) and the enhancement of the integral intensity (EII). A readout software has been developed to extract these automatically from the detector image for the measured 220, -220 and 040 Bragg peaks. The sample thickness is set to 15 mm as this enhances the sensitivity of the method and the samples are processed after the strain-field diffraction (SFD) experiments to wafers for an ex situ characterization demanding wafers. Three experimental series with a total of 21 in situ SFD experiments with different thermal treatments have been performed. The slope of the initial temperature ramp is set to 1 K/min in the first and the third series to generate a high precipitate (Bulk Micro Defect, BMD) density. In the second series the slope is chosen as 10 K/min to generate a lower density in the same silicon material. It is shown with all experiments and with preliminary works that the built up of strain during the heat treatment is caused by BMDs during the high temperature period of the treatment. The detection limit of series 1 is found at 7 nm at a density of 10{sup 13}/cm{sup 3}, of series 2 at 40 nm at a density of 2 x 10{sup 8}/cm{sup 3}, and at 8 nm at a density of 4.8 x 10{sup 12}/cm{sup 3} for series 3. The local maximum of the EII at 450 C, which emerges coincident with a local minimum of the rFWHM in series 2 may be caused by thermal donors (TD). With the experiments is shown that SFD operates in the infrared-laser scattering tomography detection range, but also reaches in a region covered only by transmission electron microscopy (TEM) so far. In contrast to these methods SFD is not limited to low temperatures and in situ experiments can be done. Thus

  3. Prodigiosin-like pigments.

    Science.gov (United States)

    Gerber, N N

    1975-05-01

    the coupling of methoxybipyrrolecarboxaldehyde (rings A and B) with methylpentylpyrrole (ring C). Recent work using 13C-labeled precursors and Fourier transform 13C nuclear magnetic resonance has shown the pattern of incorporation for acetate, proline, glycine, serine alanine, and methionine into prodigiosin. Each pyrrole ring is constructed in a different way. Two of the streptomyces pigments have also been investigated; the pattern of incorporation is similar to that for prodigiosin. The biological activities of some prodiginine pigments are summarized. All show activity against several Gram-positive bacteria; some have anti-malarial activity. Prodigiosin has been tested clinically against coccidioidomycosis.

  4. Analysis of ancient pigments by Raman microscopy

    International Nuclear Information System (INIS)

    Zuo Jian; Xu Cunyi

    1999-01-01

    Raman microscopy can be applied for the spatial resolution, and non-destructive in situ analysis of inorganic pigments in pottery, manuscripts and paintings. Compared with other techniques, it is the best single technique for this purpose. An overview is presented of the applications of Raman microscopy in the analysis of ancient pigments

  5. Experimental Investigation and High Resolution Simulation of In-Situ Combustion Processes

    Energy Technology Data Exchange (ETDEWEB)

    Margot Gerritsen; Tony Kovscek

    2008-04-30

    This final technical report describes work performed for the project 'Experimental Investigation and High Resolution Numerical Simulator of In-Situ Combustion Processes', DE-FC26-03NT15405. In summary, this work improved our understanding of in-situ combustion (ISC) process physics and oil recovery. This understanding was translated into improved conceptual models and a suite of software algorithms that extended predictive capabilities. We pursued experimental, theoretical, and numerical tasks during the performance period. The specific project objectives were (i) identification, experimentally, of chemical additives/injectants that improve combustion performance and delineation of the physics of improved performance, (ii) establishment of a benchmark one-dimensional, experimental data set for verification of in-situ combustion dynamics computed by simulators, (iii) develop improved numerical methods that can be used to describe in-situ combustion more accurately, and (iv) to lay the underpinnings of a highly efficient, 3D, in-situ combustion simulator using adaptive mesh refinement techniques and parallelization. We believe that project goals were met and exceeded as discussed.

  6. ceramic pigment

    Indian Academy of Sciences (India)

    Co costs and environmental impact, most of the current research activities concerning Co-based blue pigments have been focused upon the minimization of the employed amount of Co in their formulation (thus reducing both the economic costs and the toxicity). Accordingly, several studies have been previously reported on ...

  7. In situ TEM-tandem/implanter interface facility in Wuhan University for investigation of radiation effects

    International Nuclear Information System (INIS)

    Guo Liping; Li Ming; Liu Chuansheng; Song Bo; Ye Mingsheng; Fan Xiangjun; Fu Dejun

    2007-01-01

    Transmission electron microscope (TEM) interfaced to one or more ion implanters and/or accelerators, i.e. in situ TEM, provides effective tools to observe microstructural changes of studied samples during the ion irradiation. Evolution of both radiation damages and irradiation-induced nano-sized microstructures can be investigated with this technique, much more convenient than conventional ex situ techniques. In situ TEM technique has been widely applied in various fields, especially in the study of radiation damages of structural materials of fission and fusion nuclear reactors, and in evaluation and qualification of radioactive waste forms. Nowadays there are more than a dozen such facilities located in Japan, France, and the United States. Recently, we have constructed the first TEM-Tandem/Implanter interface facility of China in Wuhan University. A modified Hitachi H800 TEM was interfaced to a 200 kV ion implanter and a 2 x 1.7 MV tandem accelerator. Effective steps were taken to isolate the TEM from mechanical vibration from the ion beam line, and no obvious wobbling of the TEM image was observed during the ion implantation. The amorphization process of Si crystal irradiated by 115 keV N + ion beam was observed in the primary experiments, demonstrating that this interface facility is capable of in situ study of radiation effects. An online low energy gaseous ion source which may provide 1-20 keV H + and He + is under construction. (authors)

  8. In situ membrane bending setup for strain-dependent scanning transmission x-ray microscopy investigations.

    Science.gov (United States)

    Finizio, S; Wintz, S; Kirk, E; Raabe, J

    2016-12-01

    We present a setup that allows for the in situ generation of tensile strains by bending x-ray transparent Si 3 N 4 membranes with the application of a pressure difference between the two sides of the membrane, enabling the possibility to employ high resolution space- and time-resolved scanning transmission x-ray microscopy for the investigation of the magneto-elastic coupling.

  9. ceramic pigment

    Indian Academy of Sciences (India)

    sintering process). The other samples show practically the same morphology, and the mean particle size of the obtained powders is in agreement with that for inorganic pigments used in most applications (i.e., between 0.1 and 10 μm [13]). 3.3 Optical spectroscopy (powders). Since Co2SiO4 mineral owes its violet colour to ...

  10. "In situ" observation of the role of chloride ion binding to monkey green sensitive visual pigment by ATR-FTIR spectroscopy.

    Science.gov (United States)

    Katayama, Kota; Furutani, Yuji; Iwaki, Masayo; Fukuda, Tetsuya; Imai, Hiroo; Kandori, Hideki

    2018-01-31

    Long-wavelength-sensitive (LWS) pigment possesses a chloride binding site in its protein moiety. The binding of chloride alters the absorption spectra of LWS; this is known as the chloride effect. Although the two amino acid substitutions of His197 and Lys200 influence the chloride effect, the molecular mechanism of chloride binding, which underlies the spectral tuning, has yet to be clarified. In this study, we applied ATR-FTIR spectroscopy to monkey green (MG) pigment to gain structural information of the chloride binding site. The results suggest that chloride binding stabilizes the β-sheet structure on the extracellular side loop with perturbation of the retinal polyene chain, promotes a hydrogen bonding exchange with the hydroxyl group of Tyr, and alters the protonation state of carboxylate. Combining with the results of the binding analyses of various anions (Br - , I - and NO 3 - ), our findings suggest that the anion binding pocket is organized for only Cl - (or Br - ) to stabilize conformation around the retinal chromophore, which is functionally relevant with absorbing long wavelength light.

  11. The ultrasonic technique for in situ investigations on stones: suggestions for uses

    Science.gov (United States)

    Bellopede, R.; Marini, P.

    2012-04-01

    The Ultrasound Pulse Velocity (UPV) is one of the main non destructive techniques to detect both in laboratory and in situ the stone decay and many international papers of the recent years deal with its application. This technique is often executed in laboratory, where the possibility to keep constant the environmental and test conditions are a guarantee of the reliability of the results. It is known in fact the UPV are mainly conditioned by the following factors: - the characteristics of the stone tested (not only petrographic properties such as texture and structure, but even specimen dimension and water content); - the transducers features such as frequency, divergence angle , near field and wavelength; - external climate factors such as environmental temperature, humidity. In spite of the many factors affecting the measurements, UPV performed in laboratory is well correlated with mechanical strength of the stone , with its porosity and, as consequence, it is a reliable technique to detect the durability of a stone. On the other side, for in situ UPV test it is important to take into account that the measurement uncertainty is affected by the unknown water content in the stone. From tests performed on different rocks (marble, limestones, travertines, granites, gneiss, schists , sandstones) , the ratios between UPV tested in dry and saturated conditions can be > 1 or slab, with a known UPV in dry conditions, to be exposed in the investigated site some days before the in situ tests, in order to appreciate the UPV variation due to climate factors.

  12. Prion structure investigated in situ, ex vivo, and in vitro by FTIR spectroscopy

    Science.gov (United States)

    Kneipp, Janina; Miller, Lisa M.; Spassov, Sashko; Sokolowski, Fabian; Lasch, Peter; Beekes, Michael; Naumann, Dieter

    2004-07-01

    Syrian hamster nervous tissue was investigated by FTIR microspectroscopy with conventional and synchrotron infrared light sources. Various tissue structures from the cerebellum and medulla oblongata of scrapie-infected and control hamsters were investigated at a spatial resolution of 50 μm. Single neurons in dorsal root ganglia of scrapie-infected hamsters were analyzed by raster scan mapping at 6 μm spatial resolution. These measurements enabled us to (i) scrutinize structural differences between infected and non-infected tissue and (ii) analyze for the first time the distribution of different protein structures in situ within single nerve cells. Single nerve cells exhibited areas of increased β-sheet content, which co-localized consistently with accumulations of the pathological prion protein (PrPSc). Spectral data were also obtained from purified, partly proteinase K digested PrPSc isolated from scrapie-infected nervous tissue of hamsters to elucidate similarities/dissimilarities between prion structure in situ and ex vivo. A further comparison is drawn to the recombinant Syrian hamster prion protein SHaPrP90-232, whose in vitro transition from the predominantly a-helical isoform to β-sheet rich oligomeric structures was also investigated by FTIR spectroscopy.

  13. MetNet - In situ observational Network and Orbital platform to investigate the Martian environment

    Science.gov (United States)

    Harri, Ari-Matti; Leinonen, Jussi; Merikallio, Sini; Paton, Mark; Haukka, Harri; Polkko, Jouni

    2007-09-01

    MetNet Mars Mission is an in situ observational network and orbital platform mission to investigate the Martian environment and it has been proposed to European Space Agency in response to Call for proposals for the first planning cycle of Cosmic Vision 2015-2025 D/SCI/DJS/SV/val/21851. The MetNet Mars Mission is to be implemented in collaboration with ESA, FMI, LA, IKI and the payload providing science teams. The scope of the MetNet Mission is to deploy 16 MetNet Landers (MNLs) on the Martian surface by using inflatable descent system structures accompanied by an atmospheric sounder and data relay onboard the MetNet Orbiter (MNO), which is based on ESA Mars Express satellite platform. The MNLs are attached on the three sides of the satellite and most of the MNLs are deployed to Mars separately a few weeks prior to the arrival to Mars. The MetNet Orbiter will perform continuous atmospheric soundings thus complementing the accurate in situ observations at the Martian ground produced by the MetNet observation network, as well as the orbiter will serve as the primary data relay between the MetNet Landers and the Earth. The MNLs are equipped with a versatile science payload focused on the atmospheric science of Mars. Detailed characterisation of the Martian atmospheric circulation patterns, boundary layer phenomena, and climatological cycles, as well as interior investigations, require simultaneous in situ meteorological, seismic and magnetic measurements from networks of stations on the Martian surface. MetNet Mars Mission will also provide a crucial support for the safety of large landing missions in general and manned Mars missions in particular. Accurate knowledge of atmospheric conditions and weather data is essential to guarantee safe landings of the forthcoming Mars mission elements.

  14. In-situ investigation of hydrogen evolution behavior in vanadium redox flow batteries

    International Nuclear Information System (INIS)

    Wei, L.; Zhao, T.S.; Xu, Q.; Zhou, X.L.; Zhang, Z.H.

    2017-01-01

    Highlights: • An in-situ method to investigate hydrogen evolution in VRFBs is developed. • The rate of hydrogen evolution during battery operation is quantified. • The gas evolution behaviors in the charge process of VRFBs are observed. - Abstract: In this work, we conceived and fabricated a three-electrode electrochemical cell and transparent vanadium redox flow battery to in-situ investigate the hydrogen evolution reaction during battery operation. Experimental results show that operating temperature has a strong influence on the HER rate. In particular, compared with V 3+ reduction reaction, HER is more sensitive to temperature variation. It is also found that, contrary to the conventional wisdom that side reactions occur at the late stage of the charge process, H 2 evolves at a relatively low SOC. About 0.26 and 1.94 mL H 2 were collected at an early (SOC lower than 20%) and end of the charge process, respectively, suggesting that attention to the hydrogen formation at the negative electrode in the early charge process should also be paid to during long-term battery operations. Moreover, the produced hydrogen gas at the negative side prefers to form macroscopically observable bubbles onto the electrode surface, covering the active sites for vanadium redox reactions, while oxygen evolution (including CO 2 production) at the positive side corrodes electrode surface and introduces certain oxygen-containing functional groups.

  15. The visual pigment cyanide effect.

    Science.gov (United States)

    Crescitelli, F; Karvaly, B

    1989-12-01

    The visual pigment of the Tokay gecko (Gekko gekko) with its in situ absorption maximum at 521 nm has its spectral position at 500 to 505 nm when chloride-deficient digitonin is used for the extraction. In this case the addition of chloride or bromide to the extract restores the maximum to 521 nm. This property, characteristic of gecko pigments in general, does not occur with any of the rhodopsins that have been tested. Simple salts of cyanide, a pseudohalogenoid with an ionic radius close to those of chloride and bromide and/or its hydrolysis product attacks both this gecko pigment and rhodopsins in the dark. This is seen as a slow thermal loss of photopigment if (sodium) cyanide is present at concentrations above 40 mM for the gecko pigment and 150 mM for the rhodopsins of the midshipman (Porichthys notatus) and of the frog (Rana pipiens). In all cases the loss of the photopigment is accompanied by the appearance of a spectral product with maximum absorption at about 340 nm. Cyanide addition has no effect on the photosensitivity of the native pigments and neither does it alter, as do chloride, bromide and other anions, the spectral absorbance curve. The spectral product at 340 nm also appears when the visual pigments are photolyzed in the presence of cyanide salts below the threshold concentrations given above. Incubation of digitonin-solubilized all-trans-retinal with (sodium) cyanide leads to a reaction product with absorption spectrum similar to that obtained with visual pigments under comparable conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Investigating the use of in situ liquid cell scanning transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Nguy, Amanda [Iowa State Univ., Ames, IA (United States)

    2016-02-19

    Engineering nanoparticles with desired shape-dependent properties is the key to many applications in nanotechnology. Although many synthetic procedures exist to produce anisotropic gold nanoparticles, the dynamics of growth are typically unknown or hypothetical. In the case of seed-mediated growth in the presence of DNA into anisotropic nanoparticles, it is not known exactly how DNA directs growth into specific morphologies. A series of preliminary experiments were carried out to contribute to the investigation of the possible mechanism of DNA-mediated growth of gold nanoprisms into gold nanostars using liquid cell scanning transmission electron microscopy (STEM). Imaging in the liquid phase was achieved through the use of a liquid cell platform and liquid cell holder that allow the sample to be contained within a “chip sandwich” between two electron transparent windows. Ex situ growth experiments were performed using Au-T30 NPrisms (30-base thymine oligonucleotide-coated gold nanoprisms) that are expected to grow into gold nanostars. Growth to form these nanostars were imaged using TEM (transmission electron microscopy) and liquid cell STEM (scanning transmission electron microscopy). An attempt to perform in situ growth experiments with the same Au-T30 nanoprisms revealed challenges in obtaining desired morphology results due to the environmental differences within the liquid cell compared to the ex situ environment. Different parameters in the experimental method were explored including fluid line set up, simultaneous and alternating reagent addition, and the effect of different liquid cell volumes to ensure adequate flow of reagents into the liquid cell. Lastly, the binding affinities were compared for T30 and A30 DNA incubated with gold nanoparticles using zeta potential measurements, absorption spectroscopy, and isothermal titration calorimetry (ITC). It was previously reported thymine bases have a lower binding affinity to gold surfaces than adenine

  17. In situ environmental transmission electron microscope investigation of NiGa nanoparticle synthesis

    DEFF Research Database (Denmark)

    Damsgaard, Christian Danvad; Duchstein, Linus Daniel Leonhard; Elkjær, Christian Fink

    2011-01-01

    detailed Environmental Transmission Electron Microscope (ETEM) investigations of synthesis of NiGa nanoparticles on a thin film support. Samples were prepared by dissolving Ni(NO3)2 and Ga(NO3)3 in a Ni:Ga ratio of 5:3 in millipore water. The solution was subsequently dispersed on transmission electron...... have predicted a nickel gallium alloy to be active for this reaction [1]. NiGa catalysts prepared by incipient wetness impregnation on a high surface area silica support (Saint-Gobain NorPro), using a solution of nickel and gallium nitrates have shown very promising results [2]. This work presents...... microscope (TEM) sample grids. The sample grid was then mounted in a TEM heating holder and inserted in a FEI Titan ETEM with imaging Cs corrector as well as facilities for in situ gas reactions [3]. The ETEM was operated at 300 kV. The synthesis was performed in situ in a H2 flow of 2 Nml/min at a pressure...

  18. An in situ FTIR step-scan photoacoustic investigation of kerogen and minerals in oil shale

    Science.gov (United States)

    Alstadt, Kristin N.; Katti, Dinesh R.; Katti, Kalpana S.

    2012-04-01

    Step-scan photoacoustic infrared spectroscopy experiments were performed on Green River oil shale samples obtained from the Piceance Basin located in Colorado, USA. We have investigated the molecular nature of light and dark colored areas of the oil shale core using FTIR photoacoustic step-scan spectroscopy. This technique provided us with the means to analyze the oil shale in its original in situ form with the kerogen-mineral interactions intact. All vibrational bands characteristic of kerogen were found in the dark and light colored oil shale samples confirming that kerogen is present throughout the depth of the core. Depth profiling experiments indicated that there are changes between layers in the oil shale molecular structure at a length scale of micron. Comparisons of spectra from the light and dark colored oil shale core samples suggest that the light colored regions have high kerogen content, with spectra similar to that from isolated kerogen, whereas, the dark colored areas contain more mineral components which include clay minerals, dolomite, calcite, and pyrite. The mineral components of the oil shale are important in understanding how the kerogen is "trapped" in the oil shale. Comparing in situ kerogen spectra with spectra from isolated kerogen indicate significant band shifts suggesting important nonbonded molecular interactions between the kerogen and minerals.

  19. Mechanical properties of single nanostructures investigated by in-situ AFM and micro-XRD

    Energy Technology Data Exchange (ETDEWEB)

    Cornelius, Thomas; Scheler, Thomas; Magalhaes-Paniago, Rogerio; Metzger, Till Hartmut [ESRF, Grenoble (France)

    2010-07-01

    In recent years, nanostructures attracted enormous attention due to size-effects influencing the structural, optical, electrical, and mechanical properties of materials with low dimensions. Concerning the mechanical properties mainly the plastic regime was explored showing a trend that ''smaller is stronger''. In contrast, studies of the elastic behaviour of nanowires revealed contradictory results concerning the influence of size-effects on the elasticity. To investigate single nanoobjects in the elastic regime, we combined an in-situ AFM with XRD in a microfocused beam. The AFM is used to image the sample surface, to select an individual nanostructure, and to apply pressure on a chosen object. Due to the interaction between the AFM-tip and the compressed object the resonance frequency of the AFM force sensor shifts to larger values enabling us to derive the stiffness of the contact area. Simultaneous to the pressure application, XRD images around a pre-defined Bragg peak are recorded. These images allow for the determination of the elastic lattice parameter change in-situ. From the contact stiffness and the lattice parameter change, the Young modulus of an individual nanoobject is derived. Here, we present results both for SiGe islands grown by liquid-phase epitaxy on Si wafers and GaAs nanorods created by selective-area metalorganic vapor phase epitaxy on GaAs substrates.

  20. Solar System Exploration Augmented by In-Situ Resource Utilization: Mercury and Saturn Propulsion Investigations

    Science.gov (United States)

    Palaszewski, Bryan

    2016-01-01

    Human and robotic missions to Mercury and Saturn are presented and analyzed with a range of propulsion options. Historical studies of space exploration, in-situ resource utilization (ISRU), and industrialization all point to the vastness of natural resources in the solar system. Advanced propulsion benefitted from these resources in many ways. While advanced propulsion systems were proposed in these historical studies, further investigation of nuclear options using high power nuclear thermal and nuclear pulse propulsion as well as advanced chemical propulsion can significantly enhance these scenarios. Updated analyses based on these historical visions will be presented. Nuclear thermal propulsion and ISRU enhanced chemical propulsion landers are assessed for Mercury missions. At Saturn, nuclear pulse propulsion with alternate propellant feed systems and Titan exploration with chemical propulsion options are discussed. In-situ resource utilization was found to be critical in making Mercury missions more amenable for human visits. At Saturn, refueling using local atmospheric mining was found to be difficult to impractical, while refueling the Saturn missions from Uranus was more practical and less complex.

  1. In-situ{sup 57}Fe Mössbauer characterization of iron oxides in pigments of a rupestrian painting from the Serra da Capivara National Park, in Brazil, with the backscattering Mössbauer spectrometer MIMOS II

    Energy Technology Data Exchange (ETDEWEB)

    Soares Meneses Lage, Maria Conceiç ao; Duarte Cavalcante, Luis Carlos [Federal University of Piauí (UFPI), Center of Natural Sciences (Brazil); Klingelhöfer, Göstar [Johannes Gutenberg-University Mainz, Institut Inorganic and Analytical Chemistry (Germany); Fabris, José Domingos, E-mail: jdfabris@ufmg.br [Federal University of Minas Gerais (UFMG), Department of Chemistry – ICEx (Brazil)

    2016-12-15

    It is reported the use of the miniaturized portable {sup 57}Fe Mössbauer backscattering spectrometer MIMOS II to perform in situ measurements in the archaeological site known as Toca do Boqueirão do Sítio da Pedra Furada (BPF), in Serra da Capivara National Park, in order to specifically examine shades of dark red pigments and compare their differences relatively to the light red part of the same painting. The hyperfine Mössbauer parameters reveal that the dark red area of the rupestrian painting is composed of three populations of hematite and of a small proportion of maghemite, whereas the light red are of the same painting contain hematite mixed with a small proportion of maghemite and a (super)paramagnetic Fe {sup 3+}. The Fe content in the dark red area from the rupestrian painting is of approximately twice the amount in the light red of the same prehistoric graphism. The corresponding analysis of red ochre sample collected in the excavation of these archaeological site exhibited two populations of hematite and also a small proportion of maghemite.

  2. Fabrication and in-situ STM investigation of growth dynamics of semiconductor nanostructures grown by MBE

    Energy Technology Data Exchange (ETDEWEB)

    Borisova, Svetlana

    2012-05-23

    Modern development of information technologies requires an introduction of new fundamental concepts, in order to create more efficient devices and to decrease their size. One of the most promising ways is to increase the functionality of silicon by integrating novel materials into Si-based production. This PhD thesis reports on the fabrication and investigation of the growth of semiconductor nanostructures on Si substrates by molecular beam epitaxy (MBE). In-situ scanning tunneling microscopy (STM) is a powerful technique in order to study morphological and electronic properties of the grown structures directly under ultra high vacuum (UHV) conditions. It is shown that the combination of MBE and in-situ STM enables the study of nucleation and growth dynamics at the atomic scale. It provides us with numerous information concerning the nucleation mechanism, the growth mode of the structures, adatom kinetics, influence of the lattice mismatch between the substrate and the grown structure as well as formation and morphology of crystal defects. The first part of the thesis focuses on the experimental realization based upon an existing setup. The construction of an in-situ UHV STM compatible with the MBE cluster and the technical improvement of the STM setup are described. Subsequently, test measurements are performed on the technologically most important surfaces, Ge (100) and Si (111). The second part of the thesis is dedicated to ordered small-period arrays of self-assembled Ge quantum dots (QDs) grown on pre-patterned Si (100) substrates. Small-period Ge QD crystals are highly interesting since band structure calculations indicate coupled electronic states of the QDs in the case of the small lateral period of approximately 30 nm. Small-period hole patterns with a period of 56 nm are fabricated by e-beam lithography on Si substrates. The evolution of the hole morphology during the in-situ pre-growth annealing and the Si buffer layer growth are studied. Deposition of 5

  3. Fabrication and in-situ STM investigation of growth dynamics of semiconductor nanostructures grown by MBE

    International Nuclear Information System (INIS)

    Borisova, Svetlana

    2012-01-01

    Modern development of information technologies requires an introduction of new fundamental concepts, in order to create more efficient devices and to decrease their size. One of the most promising ways is to increase the functionality of silicon by integrating novel materials into Si-based production. This PhD thesis reports on the fabrication and investigation of the growth of semiconductor nanostructures on Si substrates by molecular beam epitaxy (MBE). In-situ scanning tunneling microscopy (STM) is a powerful technique in order to study morphological and electronic properties of the grown structures directly under ultra high vacuum (UHV) conditions. It is shown that the combination of MBE and in-situ STM enables the study of nucleation and growth dynamics at the atomic scale. It provides us with numerous information concerning the nucleation mechanism, the growth mode of the structures, adatom kinetics, influence of the lattice mismatch between the substrate and the grown structure as well as formation and morphology of crystal defects. The first part of the thesis focuses on the experimental realization based upon an existing setup. The construction of an in-situ UHV STM compatible with the MBE cluster and the technical improvement of the STM setup are described. Subsequently, test measurements are performed on the technologically most important surfaces, Ge (100) and Si (111). The second part of the thesis is dedicated to ordered small-period arrays of self-assembled Ge quantum dots (QDs) grown on pre-patterned Si (100) substrates. Small-period Ge QD crystals are highly interesting since band structure calculations indicate coupled electronic states of the QDs in the case of the small lateral period of approximately 30 nm. Small-period hole patterns with a period of 56 nm are fabricated by e-beam lithography on Si substrates. The evolution of the hole morphology during the in-situ pre-growth annealing and the Si buffer layer growth are studied. Deposition of 5

  4. Preparation, characterization and application of some anti- corrosive molybdate pigments

    International Nuclear Information System (INIS)

    Abd El-Ghaffar, M.A.; El-Sawy, S.M.; Ahmed, N.M.

    2005-01-01

    Some molybdate pigments of single and mixed metal ions, namely, zinc, calcium and zinc-calcium molybdates were prepared, characterized and evaluated according to international standard methods. The evaluated pigments were incorporated in some paint formulations. The physicomechanical, chemical and corrosion protective properties of the paint films were measured; this was done in comparison with a commercial imported molybdate pigment. It was found that, the prepared pigments under investigation are fine white crystalline powders of suitable pigment properties. They can be successfully used as environmentally acceptable anti corrosive pigments. They can replace satisfactorily the similar commercial imported pigment and possess adequate or superior properties against corrosion

  5. Development of In situ Geological Investigation and Test Equipment in KURT

    International Nuclear Information System (INIS)

    Koh, Yong Kweon; Kim, Kyung Su; Park, Kyung Woo; Koh, Yong Kweon; Choi, Jong Won

    2010-12-01

    For establishment of the advanced infrastructures of KURT, geological investigation and in situ test equipment were installed. The optical sensor technique could be applicable to monitoring system for the safe operation of various kinds of facilities having static and/or dynamic characteristics, such as chemical plant, pipeline, rail, huge building, long and slim structures, bridge, subway and marine vessel. etc. The micro-seismic monitoring system is able to predict the location and timing of fracturing of rock mass and rock fall around an underground openings as well as analysis on safety of various kinds of engineering structures such as nuclear facilities and other structures. The straddle packer system for hydro-testing in a deep borehole will lead to not only improve current technical level in the field of hydraulic testing but also provide important information to radioactive waste disposal technology development and site characterization project

  6. In-situ investigation of graphene oxide under UV irradiation: Evolution of work function

    Directory of Open Access Journals (Sweden)

    Jun Li

    2015-06-01

    Full Text Available Using in-situ Kelvin probe force microscopy (KPFM to measure surface potential, we investigated the time-dependent work function evolution of solution-processed graphene oxide (GO under ultraviolet (UV irradiation. We found that the work function of GO exposed in UV shows a notable decrease with increasing irradiation time, which is proposed to be attributed to the gradual disappearance of oxygen-containing functional groups in GO during the UV-induced reduction reaction process. Fourier transform infrared spectrum and Raman spectrum were used to confirm the reduction of GO under UV irradiation. Our study would give an insight into understanding the transformation of GO’s electronic structures during the reduction process.

  7. Lithium plating in lithium-ion batteries investigated by voltage relaxation and in situ neutron diffraction

    Science.gov (United States)

    von Lüders, Christian; Zinth, Veronika; Erhard, Simon V.; Osswald, Patrick J.; Hofmann, Michael; Gilles, Ralph; Jossen, Andreas

    2017-02-01

    In this work, lithium plating is investigated by means of voltage relaxation and in situ neutron diffraction in commercial lithium-ion batteries. We can directly correlate the voltage curve after the lithium plating with the ongoing phase transformation from LiC12 to LiC6 according to the neutron diffraction data during the relaxation. Above a threshold current of C/2 at a temperature of -2 °C, lithium plating increases dramatically. The results indicate that the intercalation rate of deposited lithium seems to be constant, independent of the deposited amount. It can be observed that the amount of plating correlates with the charging rate, whereas a charging current of C/2 leads to a deposited amount of lithium of 5.5% of the charge capacity and a current of 1C to 9.0%.

  8. In-situ investigations of surface modifications by swift heavy ions

    International Nuclear Information System (INIS)

    Bolse, W.; Sankarakumar, A.; Ferhati, R.; Garmatter, D.; Haag, M.; Dautel, K.; Asdi, M.; Srivastava, N.; Widmann, B.; Bauer, M.

    2014-01-01

    We are running a High Resolution Scanning Electron Microscope in the beam line of the UNILAC ion accelerator at the GSI Helmholtz Centre for Heavy Ion Research in Danustadt, Germany, which has recently been extended also with an EDX-system and two micro-manipulators. This instrument allows us to in-situ investigate the structural and compositional development of individual objects and structures in the μm- and nm-range under swift heavy ion bombardment, from the very first ion impact up to high fluences of the order of several 10 15 /cm 2 . The sample under investigation is irradiated in small fluence steps and in between SEM-images (and EDX-scans) of one and the same surface area are taken. The irradiation can be carried out at any incidence angle between 0° and 90° and also under stepwise or continuous azimuthal rotation of the sample. The micro-manipulator system allows us to perform additional analysis like electrical and mechanical characterization as well as substrate-free EDX at sub-μm objects. We are now also able to irradiate almost free standing sub-μm structures (pasted on a nanoscale tip or held in micro-tweezers). In this report an overview over this unique instrument and its capabilities and advantages will be given, illustrated by the results of our recent in-situ studies on ion induced modification of thin films (dewetting and self-organisation) and on shaping of sub-μm objects with swift heavy ions (by taking advantage of ion sputtering, ion hammering and ion induced visco-elastic flow). (author)

  9. In situ TEM investigations of mineral growth through oriented attachment of nanoparticles

    Science.gov (United States)

    Li, D.; Nielsen, M.; Lee, J. R.; Frandsen, C.; Banfield, J. F.; Kisailus, D.; De Yoreo, J.

    2012-12-01

    The growth of crystals through aggregation and coalescence of nanoparticles is now recognized as a widespread phenomenon in biomineral, biomimetic and natural systems, and during synthetic production of nanoparticles and nanowires. The resulting crystals often exhibit complex forms ranging from quasi-one-dimensional chains to 3D hierarchical and self-similar superstructures. Yet the final structure typically diffracts as a single crystal, implying that the primary particles aligned during growth. When coalignment is accompanied by coalescence, this growth process is often referred to as oriented attachment (OA). OA is now recognized as an important mechanism of crystal growth in many materials in the environment. However, the pathway by which OA occurs has not been established. Although the preservation of primary particle morphology and formation of twins and stacking faults at particle-particle boundaries strongly suggest a sequence of whole particle alignment followed by interface elimination, atom-by-atom reorientation via dislocation and grain-boundary migration after attachment are another potential mechanism. If indeed the primary particles align before attachment, the dynamics of that process and the forces that drive it have yet to be revealed. To achieve this understanding we are investigating crystal nucleation and oriented attachment in a number of systems, such as iron oxides and oxyhydroxide as well as titanium dioxide, through in situ and ex situ TEM. We performed high-resolution TEM using a fluid cell to directly observe oriented attachment of iron oxyhydroxide nanoparticles. The particles undergo continuous rotation and interaction until they find a perfect lattice match. A sudden jump to contact then occurs over less than 1 nanometer, followed by lateral atom-by-atom addition initiated at the contact point. Interface elimination proceeds at a rate consistent with the curvature dependence of the Gibbs free energy. Measured translational and

  10. A Micro-Comb Test System for In Situ Investigation of Infiltration and Crystallization Processes

    Directory of Open Access Journals (Sweden)

    Dominik Gruber

    2017-10-01

    Full Text Available The investigation of mineralization and demineralization processes is important for the understanding of many phenomena in daily life. Many crystalline materials are exposed to decay processes, resulting in lesions, cracks, and cavities. Historical artifacts, for example, often composed of calcium carbonate (CaCO3, are damaged by exposure to acid rain or temperature cycles. Another example for lesions in a crystalline material is dental caries, which lead to the loss of dental hard tissue, mainly composed of hydroxyapatite (HAp. The filling of such cavities and lesions, to avoid further mineral loss and enable or support the remineralization, is a major effort in both areas. Nevertheless, the investigation of the filling process of these materials into the cavities is difficult due to the non-transparency and crystallinity of the concerned materials. In order to address this problem, we present a transparent, inexpensive, and reusable test system for the investigation of infiltration and crystallization processes in situ, being able to deliver datasets that could potentially be used for quantitative evaluation of the infiltration process. This was achieved using a UV-lithography-based micro-comb test system (MCTS, combined with self-assembled monolayers (SAMs to mimic the surface tension/wettability of different materials, like marble, sandstone, or human enamel. Moreover, the potential of this test system is illustrated by infiltration of a CaCO3 crystallization solution and a hydroxyapatite precursor (HApP into the MCTS.

  11. Calcium pyroxenes at Mercurian surface temperatures: investigation of in-situ emissivity spectra and thermal expansion

    Science.gov (United States)

    Ferrari, S.; Nestola, F.; Helbert, J.; Maturilli, A.; D'Amore, M.; Alvaro, M.; Domeneghetti, M.; Massironi, M.; Hiesinger, H.

    2013-12-01

    The European Space Agency and Japan Aerospace Agency mission to Mercury, named BepiColombo, will carry on board the Mercury Radiometer and Thermal Infrared Spectrometer (MERTIS) that will be able to provide surface Thermal Infra-Red (TIR) emissivity spectra from 7 to 14 μm. This range of wavelengths is very useful to identify the fine-scale structural properties of several silicates. For mineral families as pyroxenes, the emissivity peak positions are good indicators of the composition. A complication in the interpretation of MERTIS data could arise from the extreme daily surface temperature range of Mercury (70 to 725 K) that significantly affects the crystal structure and density of minerals and consequently should affect the TIR spectral signature of each single mineral present on the surface of the planet. In preparation for the MERTIS data analysis, we are extensively investigating at high temperatures conditions several mineral phases potentially detectable on the surface of Mercury. Two C2/c augitic pyroxenes, with constant calcium content and very different magnesium to iron ratio, were studied by in situ high-temperature thermal infrared spectroscopy (up to 750 K) and in situ high-temperature single-crystal X-ray diffraction (up to 770 K). The emissivity spectra of the two samples show similar band center shifts of the main three bands toward lower wavenumbers with increasing temperature. Our results indicate that the center position of bands 1 and 2 is strictly dependent on temperature, whereas the center position of band 3 is a strong function of the composition regardless the temperature. These data suggest that MERTIS spectra will be able to provide indications of C2/c augitic pyroxene with different magnesium contents and will allow a correct interpretation independently on the spectra acquisition temperature.

  12. In situ investigation of SnAgCu solder alloy microstructure

    International Nuclear Information System (INIS)

    Pietrikova, Alena; Bednarcik, Jozef; Durisin, Juraj

    2011-01-01

    Research highlights: → In situ X-ray diffraction investigation enabled detailed analysis of the melting and solidification process of the SAC305 alloy. → It was found that the SAC305 solder melts at 230 deg. C. When cooling from 240 deg. C the SAC305 alloy solidifies at the temperature of 214 deg. C. During solidification β-Sn and Cu 6 Sn 5 is also formed. Formation of Ag 3 Sn occurs at 206 deg. C and the remaining amount of alloy crystallizes approximately at 160 deg. C. → Furthermore, observation of the thermal expansion behaviour of the β-Sn tetragonal unit cell revealed linear dependence of the unit cell volume on temperature. The unit cell parameters a and c also increase linearly with the temperature. Despite the fact that the c parameter is substantially smaller than parameter a, it exhibits a significantly higher linear thermal expansion coefficient. Comparison between data obtained during heating and cooling indicates that the thermal expansion coefficient is slightly greater in the case of cooling. - Abstract: In situ X-ray diffraction experiments, using synchrotron radiation, were employed to analyze microstructure evolution of the 96.5Sn3Ag0.5Cu (wt.%)-SAC305 lead-free solder alloy during heating (30-240 deg. C), isothermal dwell (240 deg. C) and cooling (240-30 deg. C). The special emphasis was placed on the study of the melting and solidification processes, explaining formation, distribution and the order of crystallization of the crystal phases (β-Sn, intermetallic compounds) in the solder alloy. Furthermore, thermal expansion behaviour of the main constituent phase β-Sn was analyzed prior to melting and after the consequent solidification.

  13. New approaches investigating production rates of in-situ produced terrestrial cosmogenic nuclides

    Energy Technology Data Exchange (ETDEWEB)

    Merchel, Silke [CEREGE, CNRS-IRD-Universite Aix-Marseille, Aix-en-Provence (France); FZD, Dresden (Germany); Braucher, Regis; Benedetti, Lucilla; Bourles, Didier [CEREGE, CNRS-IRD-Universite Aix-Marseille, Aix-en-Provence (France)

    2010-07-01

    In-situ produced cosmogenic nuclides have proved to be valuable tools for environmental and Earth sciences. However, accurate application of this method is only possible, if terrestrial production rates in a certain environment over a certain time period and their depth-dependence within the exposed material are exactly known. Unfortunately, the existing data and models differ up to several tens of percent. Thus, one of the European project CRONUS-EU goals is the high quality calibration of the {sup 36}Cl production rate by spallation at independently dated surfaces. As part of fulfilling this task we have investigated calcite-rich samples from four medieval landslide areas in the Alps: Mont Granier, Le Claps, Dobratsch, and Veliki Vrh (330-1620 m, 1248-1442 AD). For investigating the depth-dependence of the different nuclear reactions, especially, the muon- and thermal neutron-induced contributions, we have analysed mixtures of carbonates and siliceous conglomerate samples - for {sup 10}Be, {sup 26}Al, and {sup 36}Cl - exposed at different shielding depths and taken from a core drilled in 2005 at La Ciotat, France (from surface to 11 m shielding). AMS of {sup 36}Cl was performed at LLNL and ETH, {sup 10}Be and {sup 26}Al at ASTER.

  14. Custom AFM for X-ray beamlines: in situ biological investigations under physiological conditions

    International Nuclear Information System (INIS)

    Gumí-Audenis, B.; Carlà, F.; Vitorino, M. V.; Panzarella, A.; Porcar, L.; Boilot, M.; Guerber, S.; Bernard, P.; Rodrigues, M. S.; Sanz, F.; Giannotti, M. I.; Costa, L.

    2015-01-01

    The performance of a custom atomic force microscope for grazing-incidence X-ray experiments on hydrated soft and biological samples is presented. A fast atomic force microscope (AFM) has been developed that can be installed as a sample holder for grazing-incidence X-ray experiments at solid/gas or solid/liquid interfaces. It allows a wide range of possible investigations, including soft and biological samples under physiological conditions (hydrated specimens). The structural information obtained using the X-rays is combined with the data gathered with the AFM (morphology and mechanical properties), providing a unique characterization of the specimen and its dynamics in situ during an experiment. In this work, lipid monolayers and bilayers in air or liquid environment have been investigated by means of AFM, both with imaging and force spectroscopy, and X-ray reflectivity. In addition, this combination allows the radiation damage induced by the beam on the sample to be studied, as has been observed on DOPC and DPPC supported lipid bilayers under physiological conditions

  15. In situ AFM investigation of slow crack propagation mechanisms in a glassy polymer

    Science.gov (United States)

    George, M.; Nziakou, Y.; Goerke, S.; Genix, A.-C.; Bresson, B.; Roux, S.; Delacroix, H.; Halary, J.-L.; Ciccotti, M.

    2018-03-01

    A novel experimental technique based on in situ AFM monitoring of the mechanisms of damage and the strain fields associated to the slow steady-state propagation of a fracture in glassy polymers is presented. This micron-scale investigation is complemented by optical measurements of the sample deformation up to the millimetric macroscopic scale of the sample in order to assess the proper crack driving conditions. These multi-scale observations provide important insights towards the modeling of the fracture toughness of glassy polymers and its relationship with the macromolecular structure and non-linear rheological properties. This novel technique is first tested on a standard PMMA thermoplastic in order to both evaluate its performance and the richness of this new kind of observations. Although the fracture propagation in PMMA is well known to proceed through crazing in the bulk of the samples, our observations provide a clear description and quantitative evaluation of a change of fracture mechanism towards shear yielding fracture accompanied by local necking close to the free surface of the sample, which can be explained by the local change of stress triaxiality. Moreover, this primary surface necking mechanism is shown to be accompanied by a network of secondary grooves that can be related to surface crazes propagating towards the interior of the sample. This overall scenario is validated by post-mortem fractographic investigations by scanning electron microscopy.

  16. Custom AFM for X-ray beamlines: in situ biological investigations under physiological conditions

    Energy Technology Data Exchange (ETDEWEB)

    Gumí-Audenis, B. [ESRF, The European Synchrotron, Grenoble (France); Institute for Bioengineering of Catalonia (IBEC), Barcelona (Spain); Physical Chemistry Department, Universitat de Barcelona, Barcelona (Spain); Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid (Spain); Carlà, F. [ESRF, The European Synchrotron, Grenoble (France); Vitorino, M. V. [University of Lisboa, Falculty of Science, Biosystems and Integrative Sciences Institute - BIOISI, Lisbon (Portugal); Panzarella, A. [ESRF, The European Synchrotron, Grenoble (France); Porcar, L. [Institut Laue-Langevin, Grenoble (France); Boilot, M. [ORTEC, Marseille (France); Guerber, S. [CEA, LETI Grenoble (France); Bernard, P. [ESRF, The European Synchrotron, Grenoble (France); Rodrigues, M. S. [University of Lisboa, Falculty of Science, Biosystems and Integrative Sciences Institute - BIOISI, Lisbon (Portugal); Sanz, F.; Giannotti, M. I. [Institute for Bioengineering of Catalonia (IBEC), Barcelona (Spain); Physical Chemistry Department, Universitat de Barcelona, Barcelona (Spain); Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid (Spain); Costa, L., E-mail: luca.costa@esrf.fr [ESRF, The European Synchrotron, Grenoble (France)

    2015-09-30

    The performance of a custom atomic force microscope for grazing-incidence X-ray experiments on hydrated soft and biological samples is presented. A fast atomic force microscope (AFM) has been developed that can be installed as a sample holder for grazing-incidence X-ray experiments at solid/gas or solid/liquid interfaces. It allows a wide range of possible investigations, including soft and biological samples under physiological conditions (hydrated specimens). The structural information obtained using the X-rays is combined with the data gathered with the AFM (morphology and mechanical properties), providing a unique characterization of the specimen and its dynamics in situ during an experiment. In this work, lipid monolayers and bilayers in air or liquid environment have been investigated by means of AFM, both with imaging and force spectroscopy, and X-ray reflectivity. In addition, this combination allows the radiation damage induced by the beam on the sample to be studied, as has been observed on DOPC and DPPC supported lipid bilayers under physiological conditions.

  17. Next generation in-situ optical Raman sensor for seawater investigations

    Science.gov (United States)

    Kolomijeca, A.; Kwon, Y.-H.; Ahmad, H.; Kronfeldt, H.-D.

    2012-04-01

    We introduce the next generation of optical sensors based on a combination of surfaced enhanced Raman scattering (SERS) and shifted excitation Raman difference spectroscopy (SERDS) suited for investigations of tiny concentrations of pollutions in the seawater. First field measurements were carried out in the Arctic area which is of global interest since it is more affected by global warming caused climatic changes than any other areas of our planet and it is a recipient for many toxic organic pollutants. A significant long-range atmospheric transport of pollutants to Svalbard is mainly originated from industrialized countries in Europe and North America during the last decades. Therefore, the main interest is to investigate the Arctic water column and also the sediments. Standard chemical methods for water/sediment analysis are extremely accurate but complex and time-consuming. The primary objective of our study was to develop a fast response in-situ optical sensor for easy to use and quick analysis. The system comprises several components: a handheld measurement head containing a 671 nm microsystem diode laser and the Raman optical bench, a laser driver electronics board, a custom-designed miniature spectrometer with an optical resolution of 8 cm-1 and a netbook to control the spectrometer as well as for data evaluation. We introduced for the first time the portable Raman sensor system on an Artic sea-trial during a three week cruise on board of the James Clark Ross research vessel in August 2011. Numerous Raman and SERS measurements followed by SERDS evaluations were taken around locations 78° N and 9° E. Different SERS substrates developed for SERS measurements in sea-water were tested for their capability to detect different substances (PAHs) in the water down to very small (nmol/l) concentrations. Stability tests of the substrates were carried out also for the applicability of our system e.g. on a mooring. Details of the in-situ Raman sensor were presented

  18. Impact of salinity and pH on phytoplankton communities in a tropical freshwater system: An investigation with pigment analysis by HPLC

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, P.; Acharyya, T.; Babu, P.V.R.; Bandyopadhyay, D.

    , and variations in, phytoplankton communities were assessed by quantitative determination of their class specific marker pigments, using HPLC. Subtle changes in salinity of the freshwater by one practical salinity unit (PSU) completely removed green algae from...

  19. Identificação por microscopia Raman de pigmentos da pintura a óleo "Retrato de Murilo Mendes" de Cândido Portinari Identification of pigments from Candido Portinari's oil painting "Portrait of Murilo Mendes" by Raman microscopy

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Cappa de Oliveira

    1998-04-01

    Full Text Available In the present work "ex situ"Raman microscopy was employed in the identification of some of the pigments present in the painting "Portrait of Murilo Mendes" by Cândido Portinari. In the investigated samples it was possible to identify unambiguously two pigments: Prussian blue and lapis-lazuli (or its synthetic analogue, ultramarine blue - the former is observed together with organic substances, possibly used as dispersants, what suggests a further use of a mass for recover the painting.

  20. Novel in situ resistance measurement for the investigation of CIGS growth in a selenization process

    International Nuclear Information System (INIS)

    Liu Wei; He Qing; Li Fengyan; Li Changjian; Sun Yun; Tian Jianguo; Li Zubin

    2009-01-01

    During the selenization process of CIGS thin films, the relation between the element loss rate and the precursor depositions are analyzed. The growth of the CIGS thin films during the selenization process is investigated by the novel in situ resistance measurement, by which the formation of compound semiconductors can be observed directly and simultaneously. Their structures, phase evolutions and element losses are analyzed by XRD and XRF. Based on the experimental results, it can be concluded that the phase transforms have nothing to do with the deposition sequences of precursors, while the element loss rates are related to the deposition sequences in this process. In addition, element loss mechanisms of CIGS thin films prepared by the selenization process are analyzed by the phase evolutions and chemical combined path in the In, Ga–Se reaction processes. Moreover it is verified that the element losses are depressed by increasing the ramping-up rate finally. The results provide effective methods to fabricate high-quality CIGS thin films with low element losses

  1. In situ Investigation of Titanium Powder Microwave Sintering by Synchrotron Radiation Computed Tomography

    Directory of Open Access Journals (Sweden)

    Yu Xiao

    2016-01-01

    Full Text Available In this study, synchrotron radiation computed tomography was applied to investigate the mechanisms of titanium powder microwave sintering in situ. On the basis of reconstructed images, we observed that the sintering described in this study differs from conventional sintering in terms of particle smoothing, rounding, and short-term growth. Contacted particles were also isolated. The kinetic curves of sintering neck growth and particle surface area were obtained and compared with those of other microwave-sintered metals to examine the interaction mechanisms between mass and microwave fields. Results show that sintering neck growth accelerated from the intermediate period; however, this finding is inconsistent with that of aluminum powder microwave sintering described in previous work. The free surface areas of the particles were also quantitatively analyzed. In addition to the eddy current loss in metal particles, other heating mechanisms, including dielectric loss, interfacial polarization effect, and local plasma-activated sintering, contributed to sintering neck growth. Thermal and non-thermal effects possibly accelerated the sintering neck growth of titanium. This study provides a useful reference of further research on interaction mechanisms between mass and microwave fields during microwave sintering.

  2. Stability investigations of zinc and cobalt precipitates immobilized by in situ bioprecipitation (ISBP) process

    KAUST Repository

    Satyawali, Yamini

    2010-09-01

    In situ bioprecipitation (ISBP), which involves immobilizing the metals as precipitates (mainly sulphides) in the solid phase, is an effective method of metal removal from contaminated groundwater. This study investigated the stability of metal precipitates formed after ISBP in two different solid-liquid matrices (artificial and natural). The artificial matrix consisted of sand, Zn (200mgL-1), artificial groundwater and a carbon source (electron donor). Here the stability of the Zn precipitates was evaluated by manipulation of redox and pH. The natural system matrices included aquifer material and groundwater samples collected from three different metal (Zn and Co) contaminated sites and different carbon sources were provided as electron donors. In the natural matrices, metal precipitates stability was assessed by changing aquifer redox conditions, sequential extraction, and BIOMET® assay. The results indicated that, in the artificial matrix, redox manipulation did not impact the Zn precipitates. However the sequential pH change proved detrimental, releasing 58% of the precipitated Zn back into liquid phase. In natural matrices, the applied carbon source largely affected the stability of metal precipitates. Elemental analysis performed on the precipitates formed in natural matrix showed that the main elements of the precipitates were sulphur with Zn and Co. © 2010 Elsevier B.V.

  3. Investigation of Lobular Carcinoma In Situ, Using Molecular Genetic Techniques, for the Involvement of Novel Genes

    National Research Council Canada - National Science Library

    Mastracci, Teresa

    2003-01-01

    Atypical lobular hyperplasia (ALH) and lobular carcinoma in situ (LCIS), i.e. lobular neoplasia, are lesions of significance in terms of implication of risk to the patient in the development of invasive carcinorna...

  4. Compact isotope analysis system for in-situ biosignature investigation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a sensor for in-situ stable isotope analysis from a lander/rover on future planetary missions. The system will enable the collection of...

  5. Overview of plant pigments

    Science.gov (United States)

    Chlorophylls, carotenoids, flavonoids and betalains are four major classes of biological pigments produced in plants. Chlorophylls are the primary pigments responsible for plant green and photosynthesis. The other three are accessary pigments and secondary metabolites that yield non-green colors and...

  6. Related allopolyploids display distinct floral pigment profiles and transgressive pigments.

    Science.gov (United States)

    McCarthy, Elizabeth W; Berardi, Andrea E; Smith, Stacey D; Litt, Amy

    2017-01-01

    Both polyploidy and shifts in floral color have marked angiosperm evolution. Here, we investigate the biochemical basis of the novel and diverse floral phenotypes seen in allopolyploids in Nicotiana (Solanaceae) and examine the extent to which the merging of distinct genomes alters flavonoid pigment production. We analyzed flavonol and anthocyanin pigments from Nicotiana allopolyploids of different ages (N. tabacum, 0.2 million years old; several species from Nicotiana section Repandae, 4.5 million years old; and five lines of first-generation synthetic N. tabacum) as well as their diploid progenitors. Allopolyploid floral pigment profiles tend not to overlap with their progenitors or related allopolyploids, and allopolyploids produce transgressive pigments that are not present in either progenitor. Differences in floral color among N. tabacum accessions seems mainly to be due to variation in cyanidin concentration, but changes in flavonol concentrations among accessions are also present. Competition for substrates within the flavonoid biosynthetic pathway to make either flavonols or anthocyanins may drive the differences seen among related allopolyploids. Some of the pigment differences observed in allopolyploids may be associated with making flowers more visible to nocturnal pollinators. © 2017 Botanical Society of America.

  7. Solution-Processing of Organic Solar Cells: From In Situ Investigation to Scalable Manufacturing

    KAUST Repository

    Abdelsamie, Maged

    2016-12-05

    implementation of organic solar cells with high efficiency and manufacturability. In this dissertation, we investigate the mechanism of the BHJ layer formation during solution processing from common lab-based processes, such as spin-coating, with the aim of understanding the roles of materials, formulations and processing conditions and subsequently using this insight to enable the scalable manufacturing of high efficiency organic solar cells by such methods as wire-bar coating and blade-coating. To do so, we have developed state-of-the-art in situ diagnostics techniques to provide us with insight into the thin film formation process. As a first step, we have developed a modified spin-coater which allows us to perform in situ UV-visible absorption measurements during spin coating and provides key insight into the formation and evolution of polymer aggregates in solution and during the transformation to the solid state. Using this method, we have investigated the formation of organic BHJs made of a blend of poly (3-hexylthiophene) (P3HT) and fullerene, reference materials in the organic solar cell field. We show that process kinetics directly influence the microstructure and morphology of the bulk heterojunction, highlighting the value of in situ measurements. We have investigated the influence of crystallization dynamics of a wide-range of small-molecule donors and their solidification pathways on the processing routes needed for attaining high-performance solar cells. The study revealed the reason behind the need of empirically-adopted processing strategies such as solvent additives or alternatively thermal or solvent vapor annealing for achieving optimal performance. The study has provided a new perspective to materials design linking the need for solvent additives or annealing to the ease of crystallization of small-molecule donors and the presence or absence of transient phases before crystallization. From there, we have extended our investigation to small-molecule (p

  8. Investigating the correlation between radar backscatter and in situ soil property measurements

    Science.gov (United States)

    Han, Deok; Vahedifard, Farshid; Aanstoos, James V.

    2017-05-01

    Utilizing remote sensing techniques to extract soil properties can facilitate several engineering applications for large-scale monitoring and modeling purposes such as earthen levees monitoring, landslide mapping, and off-road mobility modeling. This study presents results of statistical analyses to investigate potential correlations between multiple polarization radar backscatter and various physical soil properties. The study was conducted on an approximately 3 km long section of earthen levees along the lower Mississippi river as part of the development of remote levee monitoring methods. Polarimetric synthetic aperture radar imagery from UAVSAR was used along with an extensive set of in situ soil properties. The following properties were analyzed from the top 30-50 cm of soil: texture (sand and clay fraction), penetration resistance (sleeve friction and cone tip resistance), saturated hydraulic conductivity, field capacity, permanent wilting point, and porosity. The results showed some correlation between the cross-polarized (HV) radar backscatter coefficients and most of these properties. A few soil properties, like clay fraction, showed similar but weaker correlations with the co-polarized channels (HH and VV). The correlations between the soil properties and radar backscatter were analyzed separately for the river side and land side of the levee. It was found that the magnitude and direction of the correlation for most of the soil properties noticeably differed between the river and the land sides. The findings of this study can be a good starting point for scattering modelers in a pursuit of better models for radar scattering at cross polarizations which would include more diverse set of soil parameters.

  9. Investigation of CaO-CO₂ reaction kinetics by in-situ XRD using synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Biasin, A.; Segre, C. U.; Salviulo, G.; Zorzi, F.; Strumendo, M. [Padova; (IIT)

    2015-02-05

    In this work, in-situ synchrotron radiation x-ray powder diffraction (SR-XRPD), performed at the Advanced Photon Source (APS) facilities of the Argonne National Laboratory, was applied to investigate the CaO–CO2 reaction. A set of CO2 absorption experiments were conducted in a high temperature reaction capillary with a controlled atmosphere (CO2 partial pressure of 1 bar), in the temperature range between 450 °C and 750 °C using CaO based sorbents obtained by calcination of commercial calcium carbonate. The evolution of the crystalline phases during CO2 uptake by the CaO solid sorbents was monitored for a carbonation time of 20 min as a function of the carbonation temperature and of the calcination conditions. The Rietveld refinement method was applied to estimate the calcium oxide conversion during the reaction progress and the average size of the initial (at the beginning of carbonation) calcium oxide crystallites. The measured average initial carbonation rate (in terms of conversion time derivative) of 0.280 s-1 (±13.2% standard deviation) is significantly higher than the values obtained by thermo-gravimetric analysis and reported thus far in the literature. Additionally, a dependence of the conversion versus time curves on the initial calcium oxide crystallite size was observed and a linear relationship between the initial CaO crystallite size and the calcium oxide final conversion was identified.

  10. Investigation of digestion Kinetics in commercial starches using in-situ small-angle neutron scattering

    International Nuclear Information System (INIS)

    Blazek, Jaroslav; Gilbert, Elliot Paul

    2009-01-01

    Full text: The digestion of starch has been the subject of many investigations, mostly involving in vitro measurement of the susceptibility of starches to attack by different enzymes, rather than measuring actual digestibility in vivo. The rate and extent of amylolytic hydrolysis of granular starches is known to vary according to botanical origin. Granule characteristics considered to influence susceptibility to attack by alpha-amylase include crystallinity, granule size and available specific surface, amylose content, porosity, structural inhomogeneities and degree of integrity. Most in-vitro studies of granular starch digestion have been limited to samples for which aliquots have been removed from the reaction mixture at various time intervals and freeze-dried to be subsequently characterized using a range of techniques. It remains unclear whether sample preparation creates artefacts in the samples. In this study, we have studied the kinetics of starch digestion of several commercial granular starches by time-resolved small-angle neutron scattering using an in-situ digestion chamber allowing, for the first time, to follow structural changes of starch in the course of digestion directly in the digestion mixture. Additionally, samples before and after digestion were studied by x-ray diffraction, small-angle x-ray scattering, differential scanning calorimetry and microscopy. Microscopy revealed that studied starches, which varied in their amylose content and digestion kinetics, followed different modes of attack The multidisciplinary approach allowed the nanostructural changes detected by small-angle scattering in the course of enzymic breakdown to be correlated with changes in crystallinity and functional properties.

  11. Local strain distributions in partially recrystallized copper determined by in situ tensile investigation

    DEFF Research Database (Denmark)

    Lin, Fengxiang; Ubhi, H.S.; Zhang, Yubin

    2015-01-01

    A partially recrystallized copper sample produced by cold-rolling and annealing was deformed in situ by uniaxial tension in a scanning electron microscope, and electron backscatter diffraction data were collected before and after deformation to certain strains. The local strain distributions are ...

  12. Investigating the Origin and Evolution of Venus with In Situ Mass Spectrometry

    Science.gov (United States)

    Trainer, M. G.; Mahaffy, P. R.; Brinckerhoff, W. B.; Johnson, N. M.; Glaze, L. S.

    2015-01-01

    Measurement of noble gas abundances on Venus remain a high priority for planetary science. These studies are only possible through in situ measurement, and can be accomplished by a modern neutral mass spectrometer (NMS) such as that developed at NASA Goddard, based on flight-proven technology. Here we show how the measurement of noble gases can be secured using demonstrated enrichment techniques.

  13. Seasonal and interannual variations in pigments in the Adriatic Sea

    Indian Academy of Sciences (India)

    Spatial and temporal variability of pigments was studied from the CZCS satellite data and from in situ chlorophyll and transparency for the period 1979-1985. The three Adriatic sites, Northern, Middle, and Southern Adriatic are differently in oceanographic parameters. The differences between seasonal in situ chlorophyll and ...

  14. An in-situ pilot study to investigate the native clinical resistance of enamel to erosion.

    Science.gov (United States)

    Mullan, Francesca; Austin, Rupert S; Parkinson, Charles R; Bartlett, David W

    2018-03-01

    To investigate the differences in susceptibility of the surface of native and polished enamel to dietary erosion using an in-situ model. Thirty healthy volunteers (n = 10 per group) wore mandibular appliances containing 2 native and 2 polished enamel samples for 30 min after which, the samples were exposed to either an ex-vivo or in-vivo immersion in orange juice for 5, 10 or 15 min and the cycle repeated twice with an hour's interval between them. Samples were scanned with a non-contacting laser profilometer and surface roughness was extracted from the data, together with step height and microhardness change on the polished enamel samples. All volunteers completed the study. For native enamel there were no statistical difference between baseline roughness values versus post erosion. Polished enamel significantly increased mean (SD) Sa roughness from baseline for each group resulting in roughness change of 0.04 (0.03), 0.06 (0.04), 0.04 (0.03), 0.06 (0.03), 0.08 (0.05) and 0.09 (0.05) μm respectively. With statistical differences between roughness change 45 min in-vivo versus 45 min ex-vivo (p < 0.05). Microhardness significantly decreased for each polished group, with statistical differences in hardness change between 30 min in-vivo versus 30 min ex-vivo (p < 0.05), 45 min in-vivo versus 30 min ex-vivo (p < 0.01), 45 min in-vivo versus 45 min ex-vivo (p < 0.01). The native resistance to erosion provided clinically is a combination of the ultrastructure of outer enamel, protection from the salivary pellicle and the overall effects of the oral environment. CLINICALTRIALS. NCT03178968. This study demonstrates that outer enamel is innately more resistant to erosion which is clinically relevant as once there has been structural breakdown at this level the effects of erosive wear will be accelerated. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Laboratory investigations of Titan haze formation: In situ measurement of gas and particle composition

    Science.gov (United States)

    Hörst, Sarah M.; Yoon, Y. Heidi; Ugelow, Melissa S.; Parker, Alex H.; Li, Rui; de Gouw, Joost A.; Tolbert, Margaret A.

    2018-02-01

    Prior to the arrival of the Cassini-Huygens spacecraft, aerosol production in Titan's atmosphere was believed to begin in the stratosphere where chemical processes are predominantly initiated by far ultraviolet (FUV) radiation. However, measurements taken by the Cassini Ultraviolet Imaging Spectrograph (UVIS) and Cassini Plasma Spectrometer (CAPS) indicate that haze formation initiates in the thermosphere where there is a greater flux of extreme ultraviolet (EUV) photons and energetic particles available to initiate chemical reactions, including the destruction of N2. The discovery of previously unpredicted nitrogen species in measurements of Titan's atmosphere by the Cassini Ion and Neutral Mass Spectrometer (INMS) indicates that nitrogen participates in the chemistry to a much greater extent than was appreciated before Cassini. The degree of nitrogen incorporation in the haze particles is important for understanding the diversity of molecules that may be present in Titan's atmosphere and on its surface. We have conducted a series of Titan atmosphere simulation experiments using either spark discharge (Tesla coil) or FUV photons (deuterium lamp) to initiate chemistry in CH4/N2 gas mixtures ranging from 0.01% CH4/99.99% N2 to 10% CH4/90% N2. We obtained in situ real-time measurements using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) to measure the particle composition as a function of particle size and a proton-transfer ion-trap mass spectrometer (PIT-MS) to measure the composition of gas phase products. These two techniques allow us to investigate the effect of energy source and initial CH4 concentration on the degree of nitrogen incorporation in both the gas and solid phase products. The results presented here confirm that FUV photons produce not only solid phase nitrogen bearing products but also gas phase nitrogen species. We find that in both the gas and solid phase, nitrogen is found in nitriles rather than amines and that both the

  16. Micro-analytical evidence of origin and degradation of copper pigments found in Bohemian Gothic murals.

    Science.gov (United States)

    Svarcová, Silvie; Hradil, David; Hradilová, Janka; Kocí, Eva; Bezdicka, Petr

    2009-12-01

    Correct identification of pigments and all accompanying phases found in colour layers of historical paintings are relevant for searching their origin and pigment preparation pathways and for specification of their further degradation processes. We successfully applied the analytical route combining non-destructive in situ X-ray fluorescence analyses with subsequent laboratory investigation of micro-samples by optical microscopy, scanning electron microscopy/energy-dispersive spectroscopy and X-ray powder micro-diffraction (micro-XRD) to obtain efficiently all the data relevant for mineralogical interpretations of the copper pigments origin. Cu salts (carbonates, chlorides, sulphates, etc.) used as pigments exist in a range of polymorphs with similar or identical composition. The efficiency of the micro-XRD for direct identification of such crystal phases present in micro-samples of colour layers was demonstrated in the presented paper. A new, until now unpublished, type of copper pigment--cumengeite, Pb(21)Cu(20)Cl(42)(OH)(40)--used as a blue pigment on a sacral wall painting in the Czech Republic was found by means of micro-XRD. Furthermore, azurite, malachite, paratacamite, atacamite and posnjakite were identified in fragments of colour layers of selected Gothic wall paintings. We found Cu-Zn arsenates indicating the natural origin of azurite and malachite; artificial malachite was distinguishable according to its typical spherulitic crystals. The corrosion of blue azurite to green basic Cu chloride was clearly evidenced on some places exposed to the action of salts and moisture-in a good agreement with the results of laboratory experiments, which also show that oxalic acid accelerates the corrosion of Cu pigments.

  17. Stress and toxicity of biologically important transition metals (Co, Ni, Cu and Zn) on phytoplankton in a tropical freshwater system: An investigation with pigment analysis by HPLC

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, P.; Babu, P.V.R.; Acharyya, T.; Bandyopadhyay, D.

    (-9) to 1 x 10 sup(-8) M) did not show a dramatic change in the total biomass or concentrations of the pigment markers. At concentration of 1 x 10 sup(-7) M of metal, Cu acted as a nutrient and helped to increase the biomass followed by Co, Ni and Zn...

  18. In-situ Investigation of Lead-free Solder Alloy Formation Using a Hot-plate Microscope

    DEFF Research Database (Denmark)

    Bergmann, René; Tang, Peter Torben; Hansen, Hans Nørgaard

    2007-01-01

    This work presents the advantages of using a hot-plate microscope for investigation of new (high-temperature) lead- free solders as in-situ analysis tool and preparation equipment. A description of the equipment and the preparation method is given and some examples are outlined. The formation...... phases of the Au-Sn system. The measured values are comparable to those found in the literature. An outlook to further research is also given....

  19. In situ investigation of ordering phase transformations in FePt magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Wittig, James E., E-mail: j.wittig@vanderbilt.edu [Interdisciplinary Materials Science, Vanderbilt University, PMB 351683, 2301 Vanderbilt Place, Nashville, TN 37232 (United States); Bentley, James, E-mail: bentleyj48@gmail.com [Materials Science and Technology Division, Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831-6376 (United States); Allard, Lawrence F., E-mail: allardlfjr@ornl.gov [Materials Science and Technology Division, Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831-6376 (United States)

    2017-05-15

    In situ high-resolution electron microscopy was used to reveal information at the atomic level for the disordered-to-ordered phase transformation of equiatomic FePt nanoparticles that can exhibit outstanding magnetic properties after transforming from disordered face-centered-cubic into the tetragonal L1{sub 0} ordered structure. High-angle annular dark-field imaging in the scanning transmission electron microscope provided sufficient contrast between the Fe and Pt atoms to readily monitor the ordering of the atoms during in situ heating experiments. However, during continuous high-magnification imaging the electron beam influenced the kinetics of the transformation so annealing had to be performed with the electron beam blanked. At 500 °C where the reaction rate was relatively slow, observation of the transformation mechanisms using this sequential imaging protocol revealed that ordering proceeded from (002) surface facets but was incomplete and multiple-domain particles were formed that contained anti-phase domain boundaries and anti-site defects. At 600 and 700 °C, the limitations of sequential imaging were revealed as a consequence of increased transformation kinetics. Annealing for only 5 min at 700 °C produced complete single-domain L1{sub 0} order; such single-domain particles were more spherical in shape with (002) facets. The in situ experiments also provided information concerning nanoparticle sintering, coalescence, and consolidation. Although there was resistance to complete sintering due to the crystallography of L1{sub 0} order, the driving force from the large surface-area-to-volume ratio resulted in considerable nanoparticle coalescence, which would render such FePt nanoparticles unsuitable for use as magnetic recording media. Comparison of the in situ data acquired using the protocol described above with parallel ex situ annealing experiments showed that identical behavior resulted in all cases. - Highlights: • HAADF STEM imaging reveals the

  20. Skin Pigmentation Kinetics after Exposure to Ultraviolet A

    DEFF Research Database (Denmark)

    Ravnbak, M.H.; Philipsen, P.A.; Wiegell, S.R.

    2009-01-01

    Scandinavians and 12 Indians/Pakistanis after 6 and 12 exposures on the back using broadband UVA and UVA1 with equal sub-minimal melanogenic doses (individually predetermined). Pigmentation was measured by skin reflectance at 555 and 660 urn. The UV dose to minimal pigmentation was higher in dark......Multiple exposures to ultraviolet radiation (UVR) are the norm in nature and phototherapy. However, studies of the kinetics of pigmentation following UVA exposure have included only fair-skinned persons. The aim of this study was to investigate steady-state pigmentation and fading in 12......-fold, respectively. The absolute increase in pigmentation was independent of pre-exposure pigmentation; therefore the percentage increase in pigmentation was higher in fair-skinned subjects. The absolute increase in pigmentation was higher and it took 2-3 days longer to reach steady-state after 12 UV exposures...

  1. Fine and Ultrafine Particles from Combustion Sources - Investigations with in-situ techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pagels, Joakim

    2005-04-01

    Fine airborne particles are associated with adverse health effects in the human population. The aim of this research was to develop and evaluate methods for in-situ characterisation of fine and ultrafine particles and to determine their deposition in the human airways. The aim was also to increase knowledge about health and environmentally relevant properties of aerosols from biomass combustion and selected indoor sources. The methods include instrumental techniques such as Scanning Mobility Particle Sizer (SMPS), Electrical Low-Pressure Impactor (ELPI), Aerodynamic Particle Sizer (APS) and Tandem Differential Mobility Analysers (TDMA) based on volatility and hygroscopic growth. Filter samplers and impactors were used for collecting particles on substrates for subsequent chemical analysis. Emissions from local district heating plants (0.5-12 MW), based on moving grate combustion of woody fuels, were sampled with a dilution system and characterised. Particles from the indoor sources of cigarettes, incense and candles were examined in the laboratory by using an airtight 22 m{sup 3} stainless steel chamber. A set-up to determine respiratory deposition in humans was constructed. It was automatised and uses an electrical mobility spectrometer with an improved inversion algorithm to perform fast measurements of particles of different sizes in the inhaled and exhaled air. It was evaluated on human test-persons. The investigated biomass combustion sources emit high concentrations of fine and ultrafine particles. The chemical composition is dominated by KCl and K{sub 2}SO{sub 4}; Zn, Cd and Pb were also quantified. Elemental carbon was identified in particles larger than 150 nm during periods of incomplete combustion. The particle concentration depends on the fuel ash content and the combustion efficiency. The aerosol is essentially internally mixed with hygroscopic growth factors significantly higher than reported for diesel exhaust and environmental tobacco smoke. The

  2. In situ TEM investigation of microstructural behavior of superplastic Al–Mg–Sc alloy

    Energy Technology Data Exchange (ETDEWEB)

    Dám, Karel, E-mail: damk@vscht.cz [Department of Metals and Corrosion Engineering, Institute of Chemical Technology, Prague, Technická 5, 166 28 Prague 6 (Czech Republic); Institute of Physics of the ASCR, Na Slovance 2, 182 21 Prague 8 (Czech Republic); Lejček, Pavel, E-mail: lejcekp@fzu.cz [Institute of Physics of the ASCR, Na Slovance 2, 182 21 Prague 8 (Czech Republic); Michalcová, Alena [Department of Metals and Corrosion Engineering, Institute of Chemical Technology, Prague, Technická 5, 166 28 Prague 6 (Czech Republic)

    2013-02-15

    Dynamic changes in microstructure of the superplastic ultrafine-grained Al–3Mg–0.2Sc (wt.%) alloy refined by equal-channel angular pressing (ECAP). were observed by in situ transmission electron microscopy at temperatures up to 300 °C (annealing and tensile deformation) in order to simulate the initial stages of superplastic testing. It was found that the microstructure changes significantly during the preheating before the superplastic deformation, which was accompanied by decreased microhardness. During the deformation at 300 °C, high dislocation activity as well as motion of low-angle grain boundaries was observed while high-angle grain boundaries did not move due to the presence of scandium in the alloy. - Highlights: ► We performed in situ TEM annealing and straining on superplastic Al–Mg–Sc alloy. ► We simulated the conditions of early stages of superplastic testing. ► Significant changes in microstructure occur during preheating before deformation.

  3. Thermodynamic modelling and in-situ neutron diffraction investigation of the (Nd + Mg + Zn) system

    International Nuclear Information System (INIS)

    Zhu, Zhijun; Gharghouri, Michael A.; Pelton, Arthur D.

    2016-01-01

    Highlights: • All phase diagram and thermodynamic data critically assessed for the (Nd + Mg + Zn) system. • All phases described by optimised thermodynamic models. • In-situ neutron diffraction performed to identify phases and transition temperatures. • Assessments of other (RE + Mg + Zn) systems have been carried out simultaneously. • The final product is a thermodynamic database for multicomponent (Mg + RE + Zn) systems. - Abstract: All available phase diagram data for the (Nd + Mg + Zn) system were critically assessed. In-situ neutron diffraction (ND) experiments were performed on selected samples to identify phases and transition temperatures. A critical thermodynamic evaluation and optimization of the (Nd + Mg + Zn) system was carried out and model parameters for the thermodynamic properties of all phases were obtained. The phase transformation behaviour of selected samples was well resolved from the ND experiments and experimental values were used to refine the thermodynamic model parameters.

  4. Thermodynamic modelling and in-situ neutron diffraction investigation of the (Ce + Mg + Zn) system

    International Nuclear Information System (INIS)

    Zhu, Zhijun; Gharghouri, Michael A.; Medraj, Mamoun; Lee, Soo Yeol; Pelton, Arthur D.

    2016-01-01

    Highlights: • All phase diagram and thermodynamic data critically assessed for the (Ce + Mg + Zn) system. • All phases described by optimized thermodynamic models. • In-situ neutron diffraction performed to identify phases and transition temperatures. • Assessments of other (RE + Mg + Zn) systems have been carried out simultaneously. • The final product is a thermodynamic database for multicomponent (Mg + RE + Zn) systems. - Abstract: All available phase diagram data for the (Ce + Mg + Zn) system were critically assessed. In-situ neutron diffraction (ND) experiments were performed on selected samples to identify phases and transition temperatures. A critical thermodynamic evaluation and optimization of the (Ce + Mg + Zn) system were carried out and model parameters for the thermodynamic properties of all phases were obtained. The phase transformation behaviour of selected samples was well resolved from the ND experiments and experimental data were used to refine the thermodynamic model parameters.

  5. In-situ investigation of the calcination process of mixed oxide xerogels with Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Panitz, J.C. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    The controlled calcination of materials derived by sol-gel reactions is important for the evolution of the final structure. Raman spectroscopy is an ideal tool for the identification of surface species under in-situ conditions, as demonstrated in the following for the example of a molybdenum oxide-silica xerogel. Raman spectra of this particular sample were recorded at temperatures as high as 1173 K, and compared with those of a reference material.(author) 3 figs., 4 refs.

  6. In situ TEM investigation of microstructural behavior of superplastic Al-Mg-Sc alloy

    Czech Academy of Sciences Publication Activity Database

    Dám, Karel; Lejček, Pavel; Michalcová, A.

    2013-01-01

    Roč. 76, č. 2 (2013), s. 69-75 ISSN 1044-5803 R&D Projects: GA ČR GBP108/12/G043; GA MŠk LM2011026; GA AV ČR KAN300100801 Institutional research plan: CEZ:AV0Z10100520 Keywords : aluminium alloy s * ultrafine-grained alloy s * in situ TEM * equal-channel angular pressing Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.925, year: 2013

  7. Electrochemical and in situ neutron diffraction investigations of La-Ni-Al-H alloys

    Energy Technology Data Exchange (ETDEWEB)

    Peng, W.; Redey, L.; Jansen, A.N.; Vissers, D.R.; Myles, K.M.; Carpenter, J.M.; Richardson, J.W. Jr.; Burr, G.L. [Argonne National Lab., IL (United States); Selman, J.R. [Illinois Inst. of Tech., Chicago, IL (United States). Dept. of Chemical Engineering

    1997-11-01

    The performance of selected LaNi{sub 5{minus}y}Al{sub y} hydride electrodes was studied by extensive electrochemical measurements and in situ neutron-diffraction measurements of the deuterated electrode (MD{sub x}) during electrochemical charge-discharge cycles. A small addition of aluminum increased the capacity tenfold under ambient conditions. Increased cell impedance and reduced capacity were noted through the cycle life of LaNi{sub 5{minus}y}Al{sub y}H{sub x}/NiO(OH) cells and were found to be associated with the corrosion and leaching of aluminum from the alloy. A high aluminum content alloy (y = 0.6), however, compensated for the corrosion loss of aluminum by achieving a longer cycle life than that of a low-aluminum-content alloy (y = 0.12). In situ neutron diffraction indicated that only alpha phase was present in the low-aluminum-content alloy, LaNi{sub 4.88}Al{sub 0.12}D{sub 1.1}, while both alpha and beta phases were present in LaNi{sub 4.4}Al{sub 0.6}D{sub 1.8}, the fully charged state. With in situ neutron-diffraction measurements, the absolute values of x in the MD{sub x} formula can be determined for various charge/discharge states, while the coulometry of cell cycling measures only the change in x.

  8. Genetic disorders of pigmentation.

    Science.gov (United States)

    Passeron, Thierry; Mantoux, Frédéric; Ortonne, Jean-Paul

    2005-01-01

    More than 127 loci are actually known to affect pigmentation in mouse when they are mutated. From embryogenesis to transfer of melanin to the keratinocytes or melanocytes survival, any defect is able to alter the pigmentation process. Many gene mutations are now described, but the function of their product protein and their implication in melanogenesis are only partially understood. Each genetic pigmentation disorder brings new clues in the understanding of the pigmentation process. According to the main genodermatoses known to induce hypo- or hyperpigmentation, we emphasize in this review the last advances in the understanding of the physiopathology of these diseases and try to connect, when possible, the mutation to the clinical phenotype.

  9. Solitary black pigment stones

    International Nuclear Information System (INIS)

    Wolpers, C.; Wosiewitz, U.

    1986-01-01

    Solitary pigment stones of the gall-bladder are rare (1.7%). 82,5% are radiopaque, 17.5% radiolucent. 64,8% of radiopaque solitary pigment stones have the structure of a cockade. Such cockades take years to develop. Solitary cholesterol stones with a nucleus of a radiopaque pigment stone should not be treated for litholysis. 8% of solitary cholesterol stones with a cross diameter below 15 mm. possess a radiolucent pigment stone nucleus. X-ray diagnosis for selecting litholytic treatment remains the safest method, especially if the radiologist compares his films regularly with the specimens after surgery. (orig.) [de

  10. A combined in-situ and post-mortem investigation on local permanent degradation in a direct methanol fuel cell

    Science.gov (United States)

    Bresciani, F.; Rabissi, C.; Zago, M.; Gazdzicki, P.; Schulze, M.; Guétaz, L.; Escribano, S.; Bonde, J. L.; Marchesi, R.; Casalegno, A.

    2016-02-01

    Performance degradation is one of the key issues hindering direct methanol fuel cell commercialization, caused by different mechanisms interplaying locally and resulting in both temporary and permanent contributions. This work proposes a systematic experimental investigation, coupling in-situ diagnostics (electrochemical and mass transport investigation) with ex-situ analyses of pristine, activated and aged components (X-ray photoelectron spectroscopy and transmission electron microscopy), with an in-plane and through-plane local resolution. Such a combined approach allows to identify on one hand the degradation mechanisms, the affected components and the presence of heterogeneities; on the other hand, it allows to quantify the effect of the major mechanisms on performance decay. Thanks to a novel procedure, temporary (21 μV h-1) and permanent degradation (59 μV h-1) are separated, distinguishing the latter in different contributions: the effects of active area loss at both at anode (9 μV h-1) and cathode (31 μV h-1), mass transport issue (15 μV h-1) and membrane decay (4 μV h-1). The post-mortem analysis highlights the effect of degradation mechanisms consistent with the in-situ analysis and reveals the presence of considerable in plane and through plane heterogeneities in: particle size growth in catalyst layers, Pt/Ru and polymer content in catalyst and diffusion layers, Pt/Ru precipitates in the membrane.

  11. In Situ XRD Investigations on Structural Change of P2-Layered Materials during Electrochemical Sodiation/Desodiation

    DEFF Research Database (Denmark)

    Jung, Young Hwa; Johnsen, Rune E.; Christiansen, Ane Sælland

    2014-01-01

    , No.194), which is identical to P2-layered structure. The structural changes in hexagonal P2-layered oxides have been investigated during electrochemical sodiation/desodiation by in-situ synchrotron X-ray diffractions of a capillary based micro battery cell. From the result of in-situ studies......; as a result, rich experiences for structural studies of O3-layered compounds have been accumulated over the past decades. For sodium layered oxides, however, P2-layered compounds have been reported for better cyclability and structural stability during electrochemical reactions than O3-structure. Therefore......Sodium layered oxides (NaxMO2) are attractive as positive electrode materials for rechargeable sodium-ion batteries (SIBs) due to high capacity, fast ionic diffusion and simple synthetic process. O3-layered lithium compounds have led successful commercialization of current lithium-ion batteries...

  12. In Situ XRD Investigations on Structural Change of P2-Layered Materials during Electrochemical Sodiation/Desodiation

    DEFF Research Database (Denmark)

    Jung, Young Hwa; Johnsen, Rune E.; Christiansen, Ane Sælland

    2014-01-01

    Sodium layered oxides (NaxMO2) are attractive as positive electrode materials for rechargeable sodium-ion batteries (SIBs) due to high capacity, fast ionic diffusion and simple synthetic process. O3-layered lithium compounds have led successful commercialization of current lithium-ion batteries......, systematic studies on P2-layered materials for SIBs are highly required. In this study, we report the structural and electrochemical property of P2-NaxFeyMnyCo1-2yO2 synthesized by simple solid state reaction. The X-ray diffraction pattern of as-synthesized powder is indexed as a hexagonal lattice (P63/mmc......, No.194), which is identical to P2-layered structure. The structural changes in hexagonal P2-layered oxides have been investigated during electrochemical sodiation/desodiation by in-situ synchrotron X-ray diffractions of a capillary based micro battery cell. From the result of in-situ studies...

  13. In Situ Investigations of Li-MoS2 with Planar Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Jiayu [Univ. of Maryland, College Park, MD (United States). Dept. of Materials Science and Engineering; Bao, Wenzhong [Univ. of Maryland, College Park, MD (United States). Dept. of Materials Science and Engineering and Dept. of Physics; Liu, Yang [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Center for Integrated Nanotechnologies (CINT); Dai, Jiaqi [Univ. of Maryland, College Park, MD (United States). Dept. of Materials Science and Engineering; Shen, Fei [Univ. of Maryland, College Park, MD (United States). Dept. of Materials Science and Engineering; Zhou, Lihui [Univ. of Maryland, College Park, MD (United States). Dept. of Materials Science and Engineering; Cai, Xinghan [Univ. of Maryland, College Park, MD (United States). Dept. of Physics; Urban, Daniel [Univ. of Maryland, College Park, MD (United States). Dept. of Materials Science and Engineering; Li, Yuanyuan [Univ. of Maryland, College Park, MD (United States). Dept. of Materials Science and Engineering; Jungjohann, Katherine [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Center for Integrated Nanotechnologies (CINT); Fuhrer, Michael S. [Univ. of Maryland, College Park, MD (United States). Dept. of Physics; Monash Univ., Melbourne, VIC (Australia). School of Physics; Hu, Liangbing [Univ. of Maryland, College Park, MD (United States). Dept. of Materials Science and Engineering

    2014-11-25

    For this study, a planar microbattery that enables various in situ measurements of lithiation of 2D materials on the individual-flake scale is developed. A large conductivity increase of thick MoS2 crystallite lithiation due to the formation of a percolative Mo nanoparticle network embedded in a Li2S matrix is observed. The nanoscale study leads to the development of a novel charging strategy for batteries that largely improves the capacity and cycling performance confirmed in bulk MoS2/Li coin cells.

  14. A simple constrained uniaxial tensile apparatus for in situ investigation of film stretching processing.

    Science.gov (United States)

    Meng, Lingpu; Li, Jing; Cui, Kunpeng; Chen, Xiaowei; Lin, Yuanfei; Xu, Jiali; Li, Liangbin

    2013-11-01

    A simple constrained uniaxial tensile apparatus was designed and constructed to obtain stress-strain curve during stretching and subsequent structural evolution of polymeric films. Stretch is carried out through two motor driven clamps in the machine direction and scissor-like clamps in the transverse direction keeping the sample width constant. The force information during film stretching process is recorded by a tension sensor and structural evolution can be obtained by in situ X-ray scattering technique. All parameters related to film stretching manufacturing, such as temperature, draw ratio, and stretching speed can be set independently, making the apparatus an effective method to explore the relationship between processing parameters and structure.

  15. Investigating the Mechanical Behavior and Deformation Mechanisms of Ultrafinegrained Metal Films Using Ex-situ and In-situ TEM Techniques

    Science.gov (United States)

    Izadi, Ehsan

    Nanocrystalline (NC) and Ultrafine-grained (UFG) metal films exhibit a wide range of enhanced mechanical properties compared to their coarse-grained counterparts. These properties, such as very high strength, primarily arise from the change in the underlying deformation mechanisms. Experimental and simulation studies have shown that because of the small grain size, conventional dislocation plasticity is curtailed in these materials and grain boundary mediated mechanisms become more important. Although the deformation behavior and the underlying mechanisms in these materials have been investigated in depth, relatively little attention has been focused on the inhomogeneous nature of their microstructure (particularly originating from the texture of the film) and its influence on their macroscopic response. Furthermore, the rate dependency of mechanical response in NC/UFG metal films with different textures has not been systematically investigated. The objectives of this dissertation are two-fold. The first objective is to carry out a systematic investigation of the mechanical behavior of NC/UFG thin films with different textures under different loading rates. This includes a novel approach to study the effect of texture-induced plastic anisotropy on mechanical behavior of the films. Efforts are made to correlate the behavior of UFG metal films and the underlying deformation mechanisms. The second objective is to understand the deformation mechanisms of UFG aluminum films using in-situ transmission electron microscopy (TEM) experiments with Automated Crystal Orientation Mapping. This technique enables us to investigate grain rotations in UFG Al films and to monitor the microstructural changes in these films during deformation, thereby revealing detailed information about the deformation mechanisms prevalent in UFG metal films.

  16. Analytical Investigation for In Situ Stress Measurement with Rheological Stress Recovery Method and Its Application

    Directory of Open Access Journals (Sweden)

    Quansheng Liu

    2016-01-01

    Full Text Available In situ stress is one of the most important parameters in underground engineering. Due to the difficulty and weakness of current stress measurement methods in deep soft rock, a new one, rheological stress recovery (RSR method, to determine three-dimensional stress tensor is developed. It is supposed that rock stresses will recover gradually with time and can be measured by embedding transducers into the borehole. In order to explore the relationship between the measured recovery stress and the initial stress, analytical solutions are developed for the stress measurement process with RSR method in a viscoelastic surrounding rock. The results showed that the measured recovery stress would be more close to the initial stress if the rock mass has a better rheological property, and the property of grouting material should be close to that of rock mass. Then, the RSR method, as well as overcoring technique, was carried out to measure the in situ stresses in Pingdingshan Number 1 coal mines in Henan Province, China. The stress measurement results are basically in the same order, and the major principal stresses are approximately in the direction of NW-SE, which correlates well with the stress regime of Pingdingshan zone known from the tectonic movement history.

  17. In situ QCM and TM-AFM investigations of the early stages of degradation of silver and copper surfaces

    International Nuclear Information System (INIS)

    Kleber, Ch.; Hilfrich, U.; Schreiner, M.

    2007-01-01

    The early stages of atmospheric corrosion of pure copper and pure silver specimens were investigated performing in situ tapping mode atomic force microscopy (TM-AFM), in situ quartz crystal microbalance (QCM) and X-ray photoelectron spectroscopy (XPS). The information obtained by TM-AFM is the change of the topography of the sample surfaces with emphasis on the shape and lateral distribution of the corrosion products grown within the first hours of weathering. The simultaneously performed in situ QCM measurements are indicating the mass changes due to possibly occurring corrosive processes on the surface during weathering and are therefore a valuable tool for the determination of corrosion rates. Investigations were carried out in synthetic air at different levels of relative humidity (RH) with and without addition of 250 ppb SO 2 as acidifying agent. On a polished copper surface the growth of corrosion products could be observed by TM-AFM analysis at 60% RH without any addition of acidifying gases [M. Wadsak, M. Schreiner, T. Aastrup, C. Leygraf, Surf. Sci. 454-456 (2000) 246-250]. On a weathered copper surface the addition of SO 2 to the moist air stream leads to the formation of additional features as already described in the literature [M. Wadsak, M. Schreiner, T. Aastrup, C. Leygraf, Surf. Sci. 454-456 (2000) 246-250; Ch. Kleber, J. Weissenrieder, M. Schreiner, C. Leygraf, Appl. Surf. Sci. 193 (2002) 245-253]. Exposing a silver specimen to humidity leads to the degradation of the surface structure as well as to a formation of corrosion products, which could be detected by in situ QCM measurements. After addition of 250 ppb SO 2 to the moist gas stream an increase of the formed feature's volume on the silver surface could be observed by TM-AFM measurements. The results obtained additionally from the in situ QCM measurements confirm the influence of SO 2 due to a further increase of the mass of the formed corrosion layer (and therefore an increase of the

  18. Graphene formation on metal surfaces investigated by in-situ scanning tunneling microscopy

    International Nuclear Information System (INIS)

    Dong, G C; Van Baarle, D W; Rost, M J; Frenken, J W M

    2012-01-01

    Hydrocarbon decomposition on transition metals provides a practical way of producing graphene. Here, ethylene deposition on Rh (111) is taken as an example. In-situ scanning tunneling microscopy measurements, under various growth conditions and at temperatures up to 1100 K, were carried out, revealing the processes of graphene formation at the atomic level. The initial nucleation stage nearly completely determines the phase in which further C is deposited, graphene or rhodium carbide, and the orientation of the growing graphene patches. We demonstrate that by separating the stages of nucleation and further growth and controlling other growth parameters, we obtain graphene of higher quality, while avoiding carbide formation and controlling the dissolved C to form graphene. Based on these observations, a universal physical picture emerges for graphene formation on metal surfaces. (paper)

  19. In Situ XANES/XPS Investigation of Doped Manganese Perovskite Catalysts

    Directory of Open Access Journals (Sweden)

    Daniel Mierwaldt

    2014-04-01

    Full Text Available Studying catalysts in situ is of high interest for understanding their surface structure and electronic states in operation. Herein, we present a study of epitaxial manganite perovskite thin films (Pr1−xCaxMnO3 active for the oxygen evolution reaction (OER from electro-catalytic water splitting. X-ray absorption near-edge spectroscopy (XANES at the Mn L- and O K-edges, as well as X-ray photoemission spectroscopy (XPS of the O 1s and Ca 2p states have been performed in ultra-high vacuum and in water vapor under positive applied bias at room temperature. It is shown that under the oxidizing conditions of the OER a reduced Mn2+ species is generated at the catalyst surface. The Mn valence shift is accompanied by the formation of surface oxygen vacancies. Annealing of the catalysts in O2 atmosphere at 120 °C restores the virgin surfaces.

  20. Structural Investigation of Sodium Layered Oxides Via in Situ Synchrotron X-Ray Diffraction

    DEFF Research Database (Denmark)

    Jung, Young Hwa; Christiansen, Ane Sælland; Johnsen, Rune

    2015-01-01

    Sodium layered oxides with mixed transition metals have received significant attention as positive electrode candidates for sodium-ion batteries due to high reversible capacity. Sodium layered oxides would be more promising candidates than lithium-compounds in terms of high stability of MO2 slabs...... after extraction of Na induced from larger ionic size of Na. In addition, rich crystal chemistry for sodium layered compounds is available since larger Na+ ion is stable in more spacious prismatic site as compared to Li+ ion. In view of this, the phase transformation of layered compounds during......-situ synchrotron XRD experiments. A capillary Na-based cell is designed to minimize interference in other substances such as a separator or external battery parts. This approach could give us to obtain clear diffraction patterns with high intensity during electrochemical reaction in a short period of time without...

  1. Investigation and in situ removal of spatter generated during laser ablation of aluminium composites

    Energy Technology Data Exchange (ETDEWEB)

    Popescu, A.C., E-mail: andrei.popescu@inflpr.ro [Laboratory for Advanced Materials Processing, EMPA, Feuerwerkerstrasse 39, 3602 Thun (Switzerland); National Institute for Lasers, Plasma and Radiation Physics, Atomistilor 409, 077125 Magurele (Romania); Delval, C.; Shadman, S.; Leparoux, M. [Laboratory for Advanced Materials Processing, EMPA, Feuerwerkerstrasse 39, 3602 Thun (Switzerland)

    2016-08-15

    Highlights: • Study of spatter generated during laser irradiation of an aluminium nanocomposite. • Number of droplets was 1.5–3 times higher for laser in depth vs surface focused beams. • High speed imaging revealed particles exploding in flight similar to a fireworks effect. • Three methods were selected for droplets removal in situ and the results are analyzed. - Abstract: Spatter generated during laser irradiation of an aluminium alloy nanocomposite (AlMg5 reinforced with Al{sub 2}O{sub 3} nanoparticles) was monitored by high speed imaging. Droplets trajectory and speed were assessed by computerized image analysis. The effects of laser peak power and laser focusing on the plume expansion and expulsed droplet speeds were studied in air or under argon flow. It was found that the velocity of visible droplets expulsed laterally or at the end of the plume emission from the metal surface was not dependent on the plasma plume speed. The neighbouring area of irradiation sites was studied by optical and scanning electron microscopy. Droplets deposited on the surface were classified according to their size and counted using a digital image processing software. It was observed that the number of droplets on surface was 1.5–3 times higher when the laser beam was focused in depth as compared to focused beams, even though the populations average diameter were comparable. Three methods were selected for removing droplets in situ, during plume expansion: an argon gas jet crossing the plasma plume, a fused silica plate collector transparent to the laser wavelength placed parallel to the irradiated surface and a mask placed onto the aluminium composite surface. The argon gas jet was efficient only for low power irradiation conditions, the fused silica plate failed in all tested conditions and the mask was successful for all irradiation regimes.

  2. An imaging investigation of in situ uroliths in hospitalized cats in New Zealand and in the United States

    OpenAIRE

    Wightman, Paul; Hill, Kate; Cohen, Eli; Bridges, Janis; Bolwell, Charlotte; French, John; Adler, Brian; Green, Ron

    2017-01-01

    Abstract The submission rates of feline uroliths to laboratories and the composition of uroliths have been reported in studies. The prevalence of uroliths reported on imaging findings has not been published. The objective of this retrospective study was to use imaging data to investigate the anatomical location and the prevalence of macroscopic in situ uroliths in cats. Radiographs, sonograms and imaging reports from two cohorts of cats (from New Zealand (n = 497) and the United States (n = 6...

  3. Short Communication on "In-situ TEM ion irradiation investigations on U3Si2 at LWR temperatures"

    Science.gov (United States)

    Miao, Yinbin; Harp, Jason; Mo, Kun; Bhattacharya, Sumit; Baldo, Peter; Yacout, Abdellatif M.

    2017-02-01

    The radiation-induced amorphization of U3Si2 was investigated by in-situ transmission electron microscopy using 1 MeV Kr ion irradiation. Both arc-melted and sintered U3Si2 specimens were irradiated at room temperature to confirm the similarity in their responses to radiation. The sintered specimens were then irradiated at 350 °C and 550 °C up to 7.2 × 1015 ions/cm2 to examine their amorphization behavior under light water reactor (LWR) conditions. U3Si2 remains crystalline under irradiation at LWR temperatures. Oxidation of the material was observed at high irradiation doses.

  4. [Microbial sources of pigments].

    Science.gov (United States)

    Cañizares-Villanueva, R O; Ríos-Leal, E; Olvera Ramírez, R; Ponce Noyola, T; Márquez Rocha, F

    1998-01-01

    Pigments from natural sources has been obtained since long time ago, and their interest has increased due to the toxicity problems caused by those of synthetic origin. In this way the pigments from microbial sources are a good alternative. Some of more important natural pigments, are the carotenoids, flavonoids (anthocyanins) and some tetrapirroles (chloropyls, phycobilliproteins). Another group less important are the betalains and quinones. The carotenoids are molecules formed by isoprenoids units and the most important used as colorant are the alpha and beta carotene which are precursors of vitamin A, and some xantophylls as astaxanthin. The pigment more used in the industry is the beta-carotene which is obtained from some microalgae and cyanobacteria. The astaxanthin another important carotenoid is a red pigment of great commercial value, and it is used in the pharmaceutical feed and acuaculture industries. This pigments is mainly obtained from Phaffia rhodozyma and Haematococcus pluvialis and other organisms. The phycobilliproteins obtained from cyanobacteria and some group of algae, have recently been increased on the food industries. In the last years it has been used as fluorescent marker in biochemical assays. Our research group have carried out studies about the factors that improve the production of these pigments obtained from different microbial species as well as the methods for their extraction and application.

  5. Development of microfluidic devices for in situ investigation of cells using surface-enhanced Raman spectroscopy (Conference Presentation)

    Science.gov (United States)

    Ho, Yu-Han; Galvan, Daniel D.; Yu, Qiuming

    2016-03-01

    Surface-enhanced Raman spectroscopy (SERS) has immerged as a power analytical and sensing technique for many applications in biomedical diagnosis, life sciences, food safety, and environment monitoring because of its molecular specificity and high sensitivity. The inactive Raman scattering of water molecule makes SERS a suitable tool for studying biological systems. Microfluidic devices have also attracted a tremendous interest for the aforementioned applications. By integrating SERS-active substrates with microfluidic devices, it offers a new capability for in situ investigation of biological systems, their dynamic behaviors, and response to drugs or microenvironment changes. In this work, we designed and fabricated a microfluidic device with SERS-active substrates surrounding by cell traps in microfluidic channels for in situ study of live cells using SERS. The SERS-active substrates are quasi-3D plasmonic nanostructure array (Q3D-PNA) made in h-PDMS/PMDS with physically separated gold film with nanoholes op top and gold nanodisks at the bottom of nanowells. 3D finite-difference time-domain (3D-FDTD) electromagnetic simulations were performed to design Q3D-PNAs with the strongest local electric fields (hot spots) at the top or bottom water/Au interfaces for sensitive analysis of cells and small components, respectively. The Q3D-PNAs with the hot spots on top and bottom were placed at the up and down stream of the microfluidic channel, respectively. Each Q3D-PNA pattern was surrounded with cell trapping structures. The microfluidic device was fabricated via soft lithography. We demonstrated that normal (COS-7) and cancer (HpeG2) cells were captured on the Q3D-PNAs and investigated in situ using SERS.

  6. In situ TEM investigation on the precipitation behavior of μ phase in Ni-base single crystal superalloys

    International Nuclear Information System (INIS)

    Gao, Shuang; Liu, Zhi-Quan; Li, Cai-Fu; Zhou, Yizhou; Jin, Tao

    2016-01-01

    The precipitation behavior of μ phase in Ni-base single crystal superalloys was investigated by in situ transmission electron microscopy (TEM). A layer-by-layer growth process with a ledge propagation mechanism was first observed during in situ precipitation. Three types of μ phase with different morphologies were found, which grow along [001] μ with (001) μ planar defects, [-111] μ with (1–12) μ planar defects, as well as both directions with mixed planar defects. High-resolution TEM image and established atomic models reveal a basic growth mechanism of μ phase by stacking on (001) μ plane and randomly forming coherent planar defects, while the nucleation of incoherent (1–12) μ planar defects at the early stage of precipitation plays an important role in affecting the basic growth mechanism. The frequent faults during the stacking process of the sub-unit layers within μ lattice should be responsible for the defect formation. -- Graphical abstract: In situ transmission electron microscopy (TEM) investigations reveal the layer-by-layer growth mechanism of μ phase precipitated in Ni-base single crystal superalloys. Three types of μ phase with different morphologies were formed at 1050 °C, which grows along [001] μ with (001) μ planar defects, [-111] μ with (1–12) μ planar defects, as well as both directions with mixed planar defects respectively. Formation of (001) μ micro-twin and stacking fault is the essential feature for precipitated μ phase, while nucleation of incoherent (1–12) μ planar defects plays an important role in changing growth method. Display Omitted

  7. VICI (Venus In Situ Composition Investigations): The Next Step in Understanding Venus Climate Evolution

    Science.gov (United States)

    Glaze, L. S.; Garvin, J. B.

    2017-12-01

    Venus provides a natural laboratory to explore an example of terrestrial planet evolution that may be cosmically ubiquitous. By better understanding the composition of the Venus atmosphere and surface, we can better constrain the efficiency of the Venusian greenhouse. VICI is a proposed NASA New Frontiers mission that delivers two landers to Venus on two separate Venus fly-bys. Following six orbital remote sensing missions to Venus (since 1978), VICI would be the first mission to land on the Venus surface since 1985, and the first U.S. mission to enter the Venus atmosphere in 49 years. The four major VICI science objectives are: Atmospheric origin and evolution: Understand the origin of the Venus atmosphere, how it has evolved, including how recently Venus lost its oceans, and how and why it is different from the atmospheres of Earth and Mars, through in situ measurements of key noble gases, nitrogen, and hydrogen. Atmospheric composition and structure: Reveal the unknown chemical processes and structure in Venus' deepest atmosphere that dominate the current climate through two comprehensive, in situ vertical profiles. Surface properties and geologic evolution: For the first time ever, explore the tessera from the surface, specifically to test hypotheses of ancient content-building cycles, erosion, and links to past climates using multi-point mineralogy, elemental chemistry, imaging and topography. Surface-atmosphere interactions: Characterize Venus' surface weathering environment and provide insight into the sulfur cycle at the surface-atmosphere interface by integrating rich atmospheric composition and structure datasets with imaging, surface mineralogy, and elemental rock composition. VICI is designed to study Venus' climate history through detailed atmospheric composition measurements not possible on earlier missions. In addition, VICI images the tessera surface during descent enabling detailed topography to be generated. Finally, VICI makes multiple elemental

  8. Versatile in situ powder X-ray diffraction cells for solid-gas investigations

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Torben R.; Nielsen, Thomas K.; Joergensen, Jens-Erik [Aarhus Univ. (Denmark). Center for Energy Materials, Center for Materials Crystallography; Filinchuk, Yaroslav [European Synchrotron Radiation Facility, Grenoble (France). Swiss-Norwegian Beam Lines; Cerenius, Yngve [Lund Univ. (Sweden). MAX-lab; Gray, Evan MacA.; Webb, Colin J. [Griffith Univ., Nathan, Brisbane (Australia). Queensland Micro- and Nanotechnology Centre

    2010-12-15

    This paper describes new sample cells and techniques for in situ powder X-ray diffraction specifically designed for gas absorption studies up to ca 300 bar (1 bar = 100 000 Pa) gas pressure. The cells are for multipurpose use, in particular the study of solid-gas reactions in dosing or flow mode, but can also handle samples involved in solid-liquid-gas studies. The sample can be loaded into a single-crystal sapphire (Al{sub 2}O{sub 3}) capillary, or a quartz (SiO{sub 2}) capillary closed at one end. The advantages of a sapphire single-crystal cell with regard to rapid pressure cycling are discussed, and burst pressures are calculated and measured to be {proportional_to}300 bar. An alternative and simpler cell based on a thin-walled silicate or quartz glass capillary, connected to a gas source via a VCR fitting, enables studies up to {proportional_to}100 bar. Advantages of the two cell types are compared and their applications are illustrated by case studies. (orig.)

  9. Versatile in situ powder X-ray diffraction cells for solid-gas investigations

    International Nuclear Information System (INIS)

    Jensen, Torben R.; Nielsen, Thomas K.; Joergensen, Jens-Erik; Filinchuk, Yaroslav; Cerenius, Yngve; Gray, Evan MacA.; Webb, Colin J.

    2010-01-01

    This paper describes new sample cells and techniques for in situ powder X-ray diffraction specifically designed for gas absorption studies up to ca 300 bar (1 bar = 100 000 Pa) gas pressure. The cells are for multipurpose use, in particular the study of solid-gas reactions in dosing or flow mode, but can also handle samples involved in solid-liquid-gas studies. The sample can be loaded into a single-crystal sapphire (Al 2 O 3 ) capillary, or a quartz (SiO 2 ) capillary closed at one end. The advantages of a sapphire single-crystal cell with regard to rapid pressure cycling are discussed, and burst pressures are calculated and measured to be ∝300 bar. An alternative and simpler cell based on a thin-walled silicate or quartz glass capillary, connected to a gas source via a VCR fitting, enables studies up to ∝100 bar. Advantages of the two cell types are compared and their applications are illustrated by case studies. (orig.)

  10. In situ ellipsometric investigation of stainless steel corrosion behavior in buffered solutions with amino acids

    International Nuclear Information System (INIS)

    Vinnichenko, M.V.; Pham, M.T.; Chevolleau, T.; Poperenko, L.V.; Maitz, M.F.

    2003-01-01

    The corrosion of metals is associated both with a release of ions and changes in optical surface properties. In this study, these two effects were correlated by a potentiodynamic corrosion test and in situ probing of the surface by ellipsometry. The studies were carried out with stainless steel (SS) AISI 304 and 316 in phosphate buffered saline (PBS) and in Dulbecco's modified minimal essential medium (DMEM) at pH 7.4. In both media, 304 steel is more susceptible to corrosion than 316 grade. The 316 steel shows a higher corrosion potential and higher corrosion current density in PBS than in DMEM, for 304 steel this behavior is vice versa. Ellipsometry demonstrated a higher sensitivity than potentiodynamics to surface modification in the cathodic area. In DMEM the removal of a surface layer at negative potential and a further repassivation with increasing potential was characteristic. In PBS a surface layer started to grow immediately. X-ray photoelectron spectra of this layer formed in PBS are consistent with iron phosphate. Its formation is inhibited in DMEM; the presence of amino acids is discussed as the reason

  11. Time-Dependent Damage Investigation of Rock Mass in an In Situ Experimental Tunnel

    Science.gov (United States)

    Jiang, Quan; Cui, Jie; Chen, Jing

    2012-01-01

    In underground tunnels or caverns, time-dependent deformation or failure of rock mass, such as extending cracks, gradual rock falls, etc., are a costly irritant and a major safety concern if the time-dependent damage of surrounding rock is serious. To understand the damage evolution of rock mass in underground engineering, an in situ experimental testing was carried out in a large belowground tunnel with a scale of 28.5 m in width, 21 m in height and 352 m in length. The time-dependent damage of rock mass was detected in succession by an ultrasonic wave test after excavation. The testing results showed that the time-dependent damage of rock mass could last a long time, i.e., nearly 30 days. Regression analysis of damage factors defined by wave velocity, resulted in the time-dependent evolutional damage equation of rock mass, which corresponded with logarithmic format. A damage viscoelastic-plastic model was developed to describe the exposed time-dependent deterioration of rock mass by field test, such as convergence of time-dependent damage, deterioration of elastic modules and logarithmic format of damage factor. Furthermore, the remedial measures for damaged surrounding rock were discussed based on the measured results and the conception of damage compensation, which provides new clues for underground engineering design.

  12. Nanocomposite coatings by ALD: in-situ growth investigation and applications (Conference Presentation)

    Science.gov (United States)

    Mane, Anil U.; Elam, Jeffrey W.

    2016-10-01

    We have established ALD methodology to synthesize nanocomposite coatings comprised of conducting, metallic nanoparticles embedded in an amorphous dielectric matrix. These films are nominally composed of M:Al2O3 where (M= W, Mo, and Ta) and are prepared using alternating exposures to trimethyl aluminum (TMA) and H2O for the Al2O3 ALD and alternating MF6/Si2H6 exposures for the metal ALD. By varying the ratio of ALD cycles for the metal and the Al2O3 components during material growth, we can tune precisely the various material properties such as microstructure, electrical, optical and chemical properties. The resistance of these coatings can be controlled over a very broad range (e.g. 1e11-1e4 Ohm-cm) and these films exhibit Ohmic behavior and resist breakdown even at high electric fields of area microchannel plates suitable for area photodetectors, charge drain coatings for electron optic MEMS devices (Digital Pattern Generation chips) for maskless reflection electron beam lithography system, protective coatings for Li-ion battery cathodes and solar selective absorber coating for high temperature concentrated solar power (CSP). Here we will discuss the ALD in-situ growth study, various nanocomposite material characterizations, and some of these applications.

  13. In-situ TEM investigations of graphic-epitaxy and small particles

    Science.gov (United States)

    Heinemann, K.

    1983-01-01

    Palladium was deposited inside a controlled-vacuum specimen chamber of a transmission electron microscope (TEM) onto MgO and alpha-alumina substrate surfaces. Annealing and various effects of gas exposure of the particulate Pd deposits were studied in-situ by high resolution TEM and electron diffraction. Whereas substrate temperatures of 500 C or annealing of room temperature (RT) deposits to 500 C were needed to obtain epitaxy on sapphire, RT deposits on MgO were perfectly epitaxial. For Pd/MgO a lattice expansion of 2 to 4% was noted; the highest values of expansion were found for the smallest particles. The lattice expansion of small Pd particles on alumina substrates was less than 1%. Long-time RT exposure of Pd/MgO in a vacuum yielded some moblity and coalescence events, but notably fewer than for Pd on sapphire. Exposure to air or oxygen greatly enhanced the particle mobility and coalescence and also resulted in the flattening of Pd particles on MgO substrates. Electron-beam irradiation further enhanced this effect. Exposure to air for several tens of hours of Pd/MgO led to strong coalescence.

  14. In situ vibrational spectroscopic investigation of C4 hydrocarbon selective oxidation over vanadium-phosphorus-oxide catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Zhi -Yang [Iowa State Univ., Ames, IA (United States)

    1999-05-10

    n-Butane selective oxidation over the VPO catalyst to maleic anhydride is the first and only commercialized process of light alkane selective oxidation. The mechanism of this reaction is still not well known despite over twenty years of extensive studies, which can partially be attributed to the extreme difficulties to characterize catalytic reactions real-time under typical reaction conditions. In situ spectroscopic characterization techniques such as Infrared spectroscopy and laser Raman spectroscopy were used in the current mechanistic investigations of n-butane oxidation over VPO catalysts. To identify the reaction intermediates, oxidation of n-butane, 1,3-butadiene and related oxygenates on the VPO catalyst were monitored using FTIR spectroscopy under transient conditions. n-Butane was found to adsorb on the VPO catalyst to form olefinic species, which were further oxidized to unsaturated, noncyclic carbonyl species. The open chain dicarbonyl species then experienced cycloaddition to form maleic anhydride. VPO catalyst phase transformations were investigated using in situ laser Raman spectroscopy. This report contains Chapter 1: General introduction; Chapter 2: Literature review; and Chapter 5: Conclusion and recommendations.

  15. Trace elements in natural azurite pigments found in illuminated manuscript leaves investigated by synchrotron x-ray fluorescence and diffraction mapping

    Energy Technology Data Exchange (ETDEWEB)

    Smieska, Louisa M.; Woll, Arthur R. [Cornell High Energy Synchrotron Source, Wilson Laboratory, Ithaca, NY (United States); Mullett, Ruth [Cornell University, Medieval Studies Program, Ithaca, NY (United States); Ferri, Laurent [Cornell University, Cornell Library Rare and Manuscript Collections, Ithaca, NY (United States)

    2017-07-15

    We present trace-element and composition analysis of azurite pigments in six illuminated manuscript leaves, dating from the thirteenth to sixteenth century, using synchrotron-based, large-area x-ray fluorescence (SR-XRF) and diffraction (SR-XRD) mapping. SR-XRF mapping reveals several trace elements correlated with azurite, including arsenic, zirconium, antimony, barium, and bismuth, that appear in multiple manuscripts but were not always detected by point XRF. Within some manuscript leaves, variations in the concentration of trace elements associated with azurite coincide with distinct regions of the illuminations, suggesting systematic differences in azurite preparation or purification. Variations of the trace element concentrations in azurite are greater among different manuscript leaves than the variations within each individual leaf, suggesting the possibility that such impurities reflect distinct mineralogical/geologic sources. SR-XRD maps collected simultaneously with the SR-XRF maps confirm the identification of azurite regions and are consistent with impurities found in natural mineral sources of azurite. In general, our results suggest the feasibility of using azurite trace element analysis for provenance studies of illuminated manuscript fragments, and demonstrate the value of XRF mapping in non-destructive determination of trace element concentrations within a single pigment. (orig.)

  16. Pigments in Thermophilic fungi

    OpenAIRE

    Somasundaram, T; Rao, Sanjay SR; Maheshwari, R

    1986-01-01

    UV and visible absorption spectra of thermophilic fungi were obtained by photoacoustic spectroscopy. Based on these data as well as on the chem. properties and IR spectra, it is suggested that the pigments may be hydroxylated polycyclic quinones.

  17. Chlorophyll: The wonder pigment

    Digital Repository Service at National Institute of Oceanography (India)

    Bhat, S.R.

    Chlorophyll, the green plant pigment, a 'real life force' of living beings, besides synthesizing food, is a great source of vitamins, minerals and other phytochemicals. Adding chlorophyll rich food to our diet fortifies our body against health...

  18. Photosynthetic Pigments in Diatoms

    OpenAIRE

    Kuczynska, Paulina; Jemiola-Rzeminska, Malgorzata; Strzalka, Kazimierz

    2015-01-01

    Photosynthetic pigments are bioactive compounds of great importance for the food, cosmetic, and pharmaceutical industries. They are not only responsible for capturing solar energy to carry out photosynthesis, but also play a role in photoprotective processes and display antioxidant activity, all of which contribute to effective biomass and oxygen production. Diatoms are organisms of a distinct pigment composition, substantially different from that present in plants. Apart from light-harvestin...

  19. Investigating the use of in situ liquid cell scanning transmission electron microscopy to explore DNA-mediated gold nanoparticle growth

    Science.gov (United States)

    Nguy, Amanda

    Engineering nanoparticles with desired shape-dependent properties is the key to many applications in nanotechnology. Although many synthetic procedures exist to produce anisotropic gold nanoparticles, the dynamics of growth are typically unknown or hypothetical. In the case of seed-mediated growth in the presence of DNA into anisotropic nanoparticles, it is not known exactly how DNA directs growth into specific morphologies. A series of preliminary experiments were carried out to contribute to the investigation of the possible mechanism of DNA-mediated growth of gold nanoprisms into gold nanostars using liquid cell scanning transmission electron microscopy (STEM). Imaging in the liquid phase was achieved through the use of a liquid cell platform and liquid cell holder that allow the sample to be contained within a “chip sandwich” between two electron transparent windows. Ex situ growth experiments were performed using Au-T30 NPrisms (30-base thymine oligonucleotide-coated gold nanoprisms) that are expected to grow into gold nanostars. Growth to form these nanostars were imaged using TEM (transmission electron microscopy) and liquid cell STEM (scanning transmission electron microscopy). An attempt to perform in situ growth experiments with the same Au-T30 nanoprisms revealed challenges in obtaining desired morphology results due to the environmental differences within the liquid cell compared to the ex situ environment. Different parameters in the experimental method were explored including fluid line set up, simultaneous and alternating reagent addition, and the effect of different liquid cell volumes to ensure adequate flow of reagents into the liquid cell. Lastly, the binding affinities were compared for T30 and A30 DNA incubated with gold nanoparticles using zeta potential measurements, absorption spectroscopy, and isothermal titration calorimetry (ITC). It was previously reported thymine bases have a lower binding affinity to gold surfaces than

  20. Photosynthetic Pigments in Diatoms

    Directory of Open Access Journals (Sweden)

    Paulina Kuczynska

    2015-09-01

    Full Text Available Photosynthetic pigments are bioactive compounds of great importance for the food, cosmetic, and pharmaceutical industries. They are not only responsible for capturing solar energy to carry out photosynthesis, but also play a role in photoprotective processes and display antioxidant activity, all of which contribute to effective biomass and oxygen production. Diatoms are organisms of a distinct pigment composition, substantially different from that present in plants. Apart from light-harvesting pigments such as chlorophyll a, chlorophyll c, and fucoxanthin, there is a group of photoprotective carotenoids which includes β-carotene and the xanthophylls, diatoxanthin, diadinoxanthin, violaxanthin, antheraxanthin, and zeaxanthin, which are engaged in the xanthophyll cycle. Additionally, some intermediate products of biosynthetic pathways have been identified in diatoms as well as unusual pigments, e.g., marennine. Marine algae have become widely recognized as a source of unique bioactive compounds for potential industrial, pharmaceutical, and medical applications. In this review, we summarize current knowledge on diatom photosynthetic pigments complemented by some new insights regarding their physico-chemical properties, biological role, and biosynthetic pathways, as well as the regulation of pigment level in the cell, methods of purification, and significance in industries.

  1. Photosynthetic Pigments in Diatoms

    Science.gov (United States)

    Kuczynska, Paulina; Jemiola-Rzeminska, Malgorzata; Strzalka, Kazimierz

    2015-01-01

    Photosynthetic pigments are bioactive compounds of great importance for the food, cosmetic, and pharmaceutical industries. They are not only responsible for capturing solar energy to carry out photosynthesis, but also play a role in photoprotective processes and display antioxidant activity, all of which contribute to effective biomass and oxygen production. Diatoms are organisms of a distinct pigment composition, substantially different from that present in plants. Apart from light-harvesting pigments such as chlorophyll a, chlorophyll c, and fucoxanthin, there is a group of photoprotective carotenoids which includes β-carotene and the xanthophylls, diatoxanthin, diadinoxanthin, violaxanthin, antheraxanthin, and zeaxanthin, which are engaged in the xanthophyll cycle. Additionally, some intermediate products of biosynthetic pathways have been identified in diatoms as well as unusual pigments, e.g., marennine. Marine algae have become widely recognized as a source of unique bioactive compounds for potential industrial, pharmaceutical, and medical applications. In this review, we summarize current knowledge on diatom photosynthetic pigments complemented by some new insights regarding their physico-chemical properties, biological role, and biosynthetic pathways, as well as the regulation of pigment level in the cell, methods of purification, and significance in industries. PMID:26389924

  2. Photosynthetic Pigments in Diatoms.

    Science.gov (United States)

    Kuczynska, Paulina; Jemiola-Rzeminska, Malgorzata; Strzalka, Kazimierz

    2015-09-16

    Photosynthetic pigments are bioactive compounds of great importance for the food, cosmetic, and pharmaceutical industries. They are not only responsible for capturing solar energy to carry out photosynthesis, but also play a role in photoprotective processes and display antioxidant activity, all of which contribute to effective biomass and oxygen production. Diatoms are organisms of a distinct pigment composition, substantially different from that present in plants. Apart from light-harvesting pigments such as chlorophyll a, chlorophyll c, and fucoxanthin, there is a group of photoprotective carotenoids which includes β-carotene and the xanthophylls, diatoxanthin, diadinoxanthin, violaxanthin, antheraxanthin, and zeaxanthin, which are engaged in the xanthophyll cycle. Additionally, some intermediate products of biosynthetic pathways have been identified in diatoms as well as unusual pigments, e.g., marennine. Marine algae have become widely recognized as a source of unique bioactive compounds for potential industrial, pharmaceutical, and medical applications. In this review, we summarize current knowledge on diatom photosynthetic pigments complemented by some new insights regarding their physico-chemical properties, biological role, and biosynthetic pathways, as well as the regulation of pigment level in the cell, methods of purification, and significance in industries.

  3. Recrystallization kinetics in copper investigated by in situ texture measurements by neutron diffraction

    DEFF Research Database (Denmark)

    Leffers, Torben; Hansen, Niels; Kjems, Jørgen

    1981-01-01

    The potential of neutron-diffraction texture measurement as a tool for accurate investigations of recrystallization kinetics is demonstrated by the application of the method to the recrystallization of heavily rolled copper (99.98% purity). The present investigation demonstrates that this technique...

  4. Hydrogen Absorption in Metal Thin Films and Heterostructures Investigated in Situ with Neutron and X-ray Scattering

    Directory of Open Access Journals (Sweden)

    Sara J. Callori

    2016-05-01

    Full Text Available Due to hydrogen possessing a relatively large neutron scattering length, hydrogen absorption and desorption behaviors in metal thin films can straightforwardly be investigated by neutron reflectometry. However, to further elucidate the chemical structure of the hydrogen absorbing materials, complementary techniques such as high resolution X-ray reflectometry and diffraction remain important too. Examples of work on such systems include Nb- and Pd-based multilayers, where Nb and Pd both have strong affinity to hydrogen. W/Nb and Fe/Nb multilayers were measured in situ with unpolarized and polarized neutron reflectometry under hydrogen gas charging conditions. The gas-pressure/hydrogen-concentration dependence, the hydrogen-induced macroscopic film swelling as well as the increase in crystal lattice plane distances of the films were determined. Ferromagnetic-Co/Pd multilayers were studied with polarized neutron reflectometry and in situ ferromagnetic resonance measurements to understand the effect of hydrogen absorption on the magnetic properties of the system. This electronic effect enables a novel approach for hydrogen sensing using a magnetic readout scheme.

  5. Investigation of three home-applied bleaching agents on enamel structure and mechanical properties: an in situ study

    Science.gov (United States)

    Sa, Yue; Wang, Zhejun; Ma, Xiao; Lei, Chang; Liang, Shanshan; Sun, Lili; Jiang, Tao; Wang, Yining

    2012-03-01

    The safety of at-home tooth bleaching, based upon carbamide peroxide (CP) or hydrogen peroxide (HP) as the active agent, has been questioned. The aim of the present study was to investigate the effects of three differently concentrated home-applied bleaching agents on human enamel under in situ conditions. Sixty specimens were divided randomly into four groups and treated with 10% CP, 15% CP, 20% CP, and distilled water, respectively. Raman spectroscopy, attenuated total reflectance-infrared (ATR-IR) spectroscopy, atomic force microscopy (AFM), microhardness, and fracture toughness (FT) measurements were conducted to determine variations on enamel structure and mechanical properties before and after the bleaching process. Raman revealed little variation of Raman relative intensity after treatment with CP, which was consistent with the results of ATR-IR, AFM, and microhardness analyses. In addition, laser-induced fluorescence (LIF) intensity, and FT showed significant decreases on CP-treated specimens. These findings suggested there were minimal demineralization effects of the three at-home bleaching agents on enamel in situ. However, the decrease of LIF intensity and FT on enamel seemed to be inevitable.

  6. Concepts in prototype testing for in situ geomechanical investigations at Yucca Mountain

    International Nuclear Information System (INIS)

    Luke, B.A.; Finley, R.E.

    1990-01-01

    This paper discusses the geomechanical investigations that comprise a significant portion of the site characterization program to be conducted at Yucca Mountain, the site of a proposed repository for nuclear waste. The investigations include large-scale experiments conducted in an exploratory shaft facility at the site. A program of prototype testing has been initiated to ensure the success of these expensive and complex experiments. The prototype testing program addresses three problems in rock mechanics

  7. Phase separation of in situ forming poly (lactide-co-glycolide acid) implants investigated using a hydrogel-based subcutaneous tissue surrogate and UV-vis imaging

    DEFF Research Database (Denmark)

    Sun, Yu; Jensen, Henrik; Petersen, Nickolaj J

    2017-01-01

    Phase separation of in situ forming poly (lactide-co-glycolide acid) (PLGA) implants with agarose hydrogels as the provider of nonsolvent (water) mimicking subcutaneous tissue was investigated using a novel UV-vis imaging-based analytical platform. In situ forming implants of PLGA-1-methyl-2......, water, to the in situ forming PLGA implants simulating the injection site environment. The resulting implant morphology depended on the stiffness of hydrogel matrix, indicating that the matrix in which implants are formed is of importance. Overall, the work showed that the UV-vis imaging-based platform...

  8. Skin pigmentation evaluation in broilers fed natural and synthetic pigments.

    Science.gov (United States)

    Castañeda, M P; Hirschler, E M; Sams, A R

    2005-01-01

    Broiler carcass skin color is important in the United States and Mexico. This study evaluated the use of natural and synthetic pigments in broiler diets at commercial levels. Birds were fed natural or synthetic pigments at low or high levels, simulating US and Mexican commercial practices. Skin color was measured during live production (3 to 7 wk of age) and after slaughter and chilling. The natural pigments had consistently greater skin b* values (yellowness) than the synthetic pigments. The high levels produced greater skin b* values than the low levels, regardless of source. The synthetic pigments had a slower increase in skin b* but reached the same level as the natural low by 7 wk. There was no difference in skin a* values (redness) due to pigment source or level or the age of the bird. By 7 wk, all pigment sources approached plateau levels in the blood, but the synthetic pigment diet produced higher blood levels of yellow and red pigments than the natural pigment diets. Processing intensified skin yellowness and reduced skin redness. These data suggest that although synthetic pigments might have been absorbed better than natural ones, natural pigments were more efficient at increasing skin yellowness and there were only small differences between high and low levels for each pigment source. This finding may allow reduction in pigment use and feed cost to achieve the same skin acceptance by the consumer.

  9. DNA damage in isolated rat hepatocytes exposed to C.I. pigment orange 5 and C.I. pigment yellow 12 by the alkaline comet assay

    DEFF Research Database (Denmark)

    Møller, P; Wallin, Håkan; Grunnet, N

    1998-01-01

    , and C.I. pigment orange 5 is a naphthol-azo pigment. The pigments are virtually insoluble in aqueous solutions, and they have not been tested extensively for toxicological effects. C.I. pigment orange 5 increased the levels of DNA damage at 5 microg/ml (P .../ml (P effect of incubation time (20, 40, and 80 min) of the same concentrations of the pigments was tested. The levels of DNA damage were increased up to 80 min. Both pigments produced DNA damage that was in the same range as the food carcinogen 2-amino-3,8-dimethylimidazo[4,5-f......]quinoxaline. Our data indicate that both C.I. pigment orange 5 and C.I. pigment yellow 12 are genotoxic in hepatocytes with metabolizing capacities. However, further investigation of the metabolism and disposition are required for the evaluation of the safety of these pigments....

  10. Investigating electrokinetics application for in-situ inorganic oil field scale control

    Science.gov (United States)

    Hashaykeh, Manal A. I. Albadawi

    Oil well scale formation and deposition is an expensive problem and could be a nightmare for any production engineer if the rate of deposition is rapid as in the case of North Sea oil fields. Inorganic scales accumulate in surface and subsurface equipment causing a reduction in oil production and severe damage for production equipment. The major components of most oil field scale deposits are BaSO4, CaSO4 and SrSO4, which are formed due to incompatible mixing of reservoir formation water and sea water flooded in secondary enhanced oil recovery (EOR) processes. This work focuses on BaSO4 scale as it is one of the toughest scale components to be removed either by chemical means or mechanical means. Scale control methods usually involve complicated treatment using chemical dissolution methods as primary attempt and mechanical scrapping or jetting methods in case of failure of the chemical means. In this work, we devised a novel in-situ scale control method benefiting from the application of direct current (DC) which involves some of the electrokinetic (EK) phenomena. The applications of EK has been proved in our laboratories yielding high efficiency in capturing barium and separating it from sulfate before reaching the production well, thus preventing deposition in the production wellbore or wellbore formation. This objective was evaluated in our lab designed EK apparatus in three parts. In part-1, an 18.5 cm unconsolidated sand core was used which produced inconsistent results. This problem was overcome in part-2, where the porous media involved 46 cm consolidated sandcore. This also partly fulfilled the purpose of upscaling. In part-3, the porous media was extended to a 100 cm spatial distance between the injection and production wells. For all the experiments the reservoir models were made of 125 µm uniform sand particles and followed a final consolidation pressure of 30 psi. The EK-reservoir model contains 2 basic junctions; one of them injecting a 500 ppm SO4 2

  11. Proton beam modification of lead white pigments

    International Nuclear Information System (INIS)

    Beck, L.; Gutiérrez, P.C.; Miserque, F.; Thomé, L.

    2013-01-01

    Pigments and paint materials are known to be sensitive to particle irradiation. Occasionally, the analysis of paintings by PIXE can induce a slight or dark stain depending on the experimental conditions (beam current, dose, particle energy). In order to understand this discoloration, we have irradiated various types of art white pigments – lead white (hydrocerussite and basic lead sulfate), gypsum, calcite, zinc oxide and titanium oxide – with an external 3 MeV proton micro-beam commonly used for PIXE experiments. We have observed various sensitivities depending on the pigment. No visible change occurs for calcite and titanium oxide, whereas lead white pigments are very sensitive. For the majority of the studied compounds, the discoloration is proportional to the beam current and charge. The damage induced by proton beam irradiation in lead white pigments was studied by micro-Raman and XPS spectroscopies. Structural modifications and dehydration were detected. Damage recovery was investigated by thermal treatment and UV-light irradiation. The discoloration disappeared after one week of UV illumination, showing that PIXE experiments could be safely undertaken for pigments and paintings

  12. Proton beam modification of lead white pigments

    Energy Technology Data Exchange (ETDEWEB)

    Beck, L., E-mail: lucile.beck@cea.fr [CEA, DEN, Service de Recherches de Métallurgie Physique, Laboratoire JANNUS, 91191 Gif-sur-Yvette (France); Centre de recherche et de restauration des musées de France (C2RMF), Palais du Louvre – Porte des Lions, 14 quai François Mitterrand, 75001 Paris (France); Gutiérrez, P.C. [Centre de recherche et de restauration des musées de France (C2RMF), Palais du Louvre – Porte des Lions, 14 quai François Mitterrand, 75001 Paris (France); Centro de Micro-Análisis de Materiales (CMAM), Universidad Autónoma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain); Miserque, F. [CEA, DEN, DPC/SCCME/LECA, 91191 Gif-sur-Yvette (France); Thomé, L. [Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), CNRS/IN2P3 et Université Paris-Sud, Bât. 108, 91405 Orsay (France)

    2013-07-15

    Pigments and paint materials are known to be sensitive to particle irradiation. Occasionally, the analysis of paintings by PIXE can induce a slight or dark stain depending on the experimental conditions (beam current, dose, particle energy). In order to understand this discoloration, we have irradiated various types of art white pigments – lead white (hydrocerussite and basic lead sulfate), gypsum, calcite, zinc oxide and titanium oxide – with an external 3 MeV proton micro-beam commonly used for PIXE experiments. We have observed various sensitivities depending on the pigment. No visible change occurs for calcite and titanium oxide, whereas lead white pigments are very sensitive. For the majority of the studied compounds, the discoloration is proportional to the beam current and charge. The damage induced by proton beam irradiation in lead white pigments was studied by micro-Raman and XPS spectroscopies. Structural modifications and dehydration were detected. Damage recovery was investigated by thermal treatment and UV-light irradiation. The discoloration disappeared after one week of UV illumination, showing that PIXE experiments could be safely undertaken for pigments and paintings.

  13. Non-invasive in-situ investigations versus micro-sampling: a comparative study on a Renoirs painting

    International Nuclear Information System (INIS)

    Miliani, C.; Sgamellotti, A.; Universita degli Studi di Perugia . Centro di Eccellenza SMAArt; Scientific Methodologies applied to Archaeology and Art)

    2007-01-01

    In this paper, a multi-technique in-situ non-invasive approach has been followed for the study of the materials used for a painting by Pierre-Auguste Renoir, ''A woman at her toilette''. The study was carried out using five portable spectroscopic techniques, namely X-ray fluorescence, mid-infrared reflectance spectroscopy, near infrared reflectance spectroscopy, and UV-Vis spectroscopy in absorption and emission. The painting was selected as a case study because it was examined in advance of the current investigation using conventional micro-sampling techniques. This provided the opportunity to evaluate potential and limitations of the non-invasive approach to the complex case of the modern painting. (orig.)

  14. A Preliminary Investigation of Ductility-Enhancement Mechanism through In Situ Nanofibrillation in Thermoplastic Matrix Composites

    Directory of Open Access Journals (Sweden)

    Bhaskar Patham

    2013-01-01

    Full Text Available A preliminary investigation of interrelationships between tensile stress-strain characteristics and morphology evolution during deformation is conducted on a commercially available thermoplastic composite with a low-surface-energy nanofibrillating poly(tetrafluoroethylene (PTFE additive. In this class of composites, the deformation-associated nanofibrillation of the low-surface-energy additive has been hypothesized to provide an additional dissipation mechanism, thereby enhancing the ductility of the composite. This class of composites offers potential for automotive light weighting in exterior and interior body and fascia applications; it is therefore of interest to investigate processing-structure-property interrelationships in these materials. This study specifically probes the interrelationships between the plastic deformation within the matrix and the fibrillation of the low-surface-energy additive; tensile tests are carried out at two different temperatures which are chosen so as to facilitate and suppress plastic deformation within the matrix polymer. Based on these preliminary investigations, it is noted that PTFE fibrillation acts synergistically with the ductile deformation of the matrix resin resulting in higher strains to failure of the composite; the results also suggest that the mechanism of fibrillation-assisted enhancement of strains to failure may not operate in the absence of matrix plasticity.

  15. Interaction between Vaccinium bracteatum Thunb. leaf pigment and rice proteins.

    Science.gov (United States)

    Wang, Li; Xu, Yuan; Zhou, Sumei; Qian, Haifeng; Zhang, Hui; Qi, Xiguang; Fan, Meihua

    2016-03-01

    In this study, we investigated the interaction of Vaccinium bracteatum Thunb. leaf (VBTL) pigment and rice proteins. In the presence of rice protein, VBTL pigment antioxidant activity and free polyphenol content decreased by 67.19% and 68.11%, respectively, and L(∗) of the protein-pigment complex decreased significantly over time. L(∗) values of albumin, globulin and glutelin during 60-min pigment exposure decreased by 55.00, 57.14, and 54.30%, respectively, indicating that these proteins had bound to the pigment. A significant difference in protein surface hydrophobicity was observed between rice proteins and pigment-protein complexes, indicating that hydrophobic interaction is a major binding mechanism between VBTL pigment and rice proteins. A significant difference in secondary structures between proteins and protein-pigment complexes was also uncovered, indicating that hydrogen bonding may be another mode of interaction between VBTL pigment and rice proteins. Our results indicate that VBTL pigment can stain rice proteins with hydrophobic and hydrogen interactions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Investigating Forest Harvest Effects on DOC Concentration and Quality: An In Situ, High Resolution Approach to Quantifying DOC Export Dynamics

    Science.gov (United States)

    Jollymore, A. J.; Johnson, M. S.; Hawthorne, I.

    2013-12-01

    Justification: Forest harvest effects on water quality can signal alterations in hydrologic and ecologic processes incurred as a result of forest harvest activities. Organic matter (OM), specifically dissolved organic carbon (DOC), plays a number of important roles mediating UV-light penetration, redox reactivity and microbial activity within aquatic ecosystems. Quantification of DOC is typically pursued via grab sampling followed by chemical or spectrophotometric analysis, limiting the temporal resolution obtained as well as the accuracy of export calculations. The advent of field-deployable sensors capable of measuring DOC concentration and certain quality characteristics in situ provides the ability to observe dynamics at temporal scales necessary for accurate calculation of DOC flux, as well as the observation of dynamic changes in DOC quality on timescales impossible to observe through grab sampling. Methods: This study utilizes a field deployable UV-Vis spectrophotometer (spectro::lyzer, s::can, Austria) to investigate how forest harvest affects DOC export. The sensor was installed at an existing hydrologic monitoring site at the outlet of a headwater stream draining a small (91 hectare) second growth Douglasfir-dominated catchment near Campbell River on Vancouver Island, British Columbia. Measurement began late in 2009, prior to forest harvest and associated activities such as road building (which commenced in October 2010 and ended in early 2011), and continues to present. During this time - encompassing the pre, during and post-harvest conditions - the absorbance spectrum of stream water from 200 to 750 nm was measured. DOC concentration and spectroscopic indices related to DOC quality (including SUVA, which relates to the concentration of aromatic carbon, and spectral slope) were subsequently calculated for each spectra obtained at 30-minute intervals. Results and conclusions: High frequency measurements of DOC show that overall export of OM increased in

  17. Raman af hvide pigmenter

    DEFF Research Database (Denmark)

    Reeler, Nini Elisabeth Abildgaard; Nielsen, Ole Faurskov; Sauer, Stephan P. A.

    2013-01-01

    Et samspil mellem kunst og kemi. I et samarbejde mellem Statens Museum for Kunst og Kemisk Institut på KU er Ramanspek-troskopi brugt til at definere sammensætningen af blandinger af blyhvidt og calcit i maleriers hvide pigmenter.......Et samspil mellem kunst og kemi. I et samarbejde mellem Statens Museum for Kunst og Kemisk Institut på KU er Ramanspek-troskopi brugt til at definere sammensætningen af blandinger af blyhvidt og calcit i maleriers hvide pigmenter....

  18. In situ investigation of wet chemical processes for chalcopyrite solar cells by L-edge XAS under ambient conditions

    Energy Technology Data Exchange (ETDEWEB)

    Greil, Stefanie M. [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin (Germany); Lauermann, Iver, E-mail: Iver.lauermann@helmholtz-berlin.d [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin (Germany); Ennaoui, Ahmed; Kropp, Timo; Lange, Kathrin M.; Weber, Matthieu [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin (Germany); Aziz, Emad F., E-mail: Emad.Aziz@helmholtz-berlin.d [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin (Germany)

    2010-02-15

    Two instrumental setups for in situ soft X-ray absorption spectroscopy in liquid systems are demonstrated in this work. One for investigating chemical reactions in solutions and a new one for the solid component of a liquid / (as in both / absorber) solid interface. We used these setups for investigating two production processes for chalcopyrite solar cells under ambient conditions, probing the L-edge of Zn and Cu. The first one is a flow cell with a silicon nitride membrane to study the chemical bath deposition process for Cd-free buffer layers. Examining the electronic structure of involved Zn complexes allows to determine the exact reaction mechanism taking place during this process. The second setup is a rotating disk for investigating the bath/absorber interface upon the etching process of superficial binary copper compounds of the absorber as a function of time. The time resolution of the chemical reaction demonstrated in this study ranges from the second to minute time scale.

  19. In situ investigation of wet chemical processes for chalcopyrite solar cells by L-edge XAS under ambient conditions

    International Nuclear Information System (INIS)

    Greil, Stefanie M.; Lauermann, Iver; Ennaoui, Ahmed; Kropp, Timo; Lange, Kathrin M.; Weber, Matthieu; Aziz, Emad F.

    2010-01-01

    Two instrumental setups for in situ soft X-ray absorption spectroscopy in liquid systems are demonstrated in this work. One for investigating chemical reactions in solutions and a new one for the solid component of a liquid / (as in both / absorber) solid interface. We used these setups for investigating two production processes for chalcopyrite solar cells under ambient conditions, probing the L-edge of Zn and Cu. The first one is a flow cell with a silicon nitride membrane to study the chemical bath deposition process for Cd-free buffer layers. Examining the electronic structure of involved Zn complexes allows to determine the exact reaction mechanism taking place during this process. The second setup is a rotating disk for investigating the bath/absorber interface upon the etching process of superficial binary copper compounds of the absorber as a function of time. The time resolution of the chemical reaction demonstrated in this study ranges from the second to minute time scale.

  20. In situ investigation of wet chemical processes for chalcopyrite solar cells by L-edge XAS under ambient conditions

    Science.gov (United States)

    Greil, Stefanie M.; Lauermann, Iver; Ennaoui, Ahmed; Kropp, Timo; Lange, Kathrin M.; Weber, Matthieu; Aziz, Emad F.

    2010-02-01

    Two instrumental setups for in situ soft X-ray absorption spectroscopy in liquid systems are demonstrated in this work. One for investigating chemical reactions in solutions and a new one for the solid component of a liquid / (as in both / absorber) solid interface. We used these setups for investigating two production processes for chalcopyrite solar cells under ambient conditions, probing the L-edge of Zn and Cu. The first one is a flow cell with a silicon nitride membrane to study the chemical bath deposition process for Cd-free buffer layers. Examining the electronic structure of involved Zn complexes allows to determine the exact reaction mechanism taking place during this process. The second setup is a rotating disk for investigating the bath/absorber interface upon the etching process of superficial binary copper compounds of the absorber as a function of time. The time resolution of the chemical reaction demonstrated in this study ranges from the second to minute time scale.

  1. Pigmented Bowen's disease presenting with a "starburst" pattern.

    Science.gov (United States)

    Maione, Vincenzo; Errichetti, Enzo; Roussel, Sara Laurent; Lebbé, Celeste

    2016-10-01

    Pigmented Bowen's disease (pBD) is an uncommon in situ squamous cell carcinoma of the skin usually presenting as a dark scaly plaque involving chronically exposed sites, which is not uncommonly mistaken for other similar pigmented lesions, such as melanoma, pigmented basal cell carcinoma or seborrheic keratosis [1,2]. Dermoscopy has been proven to improve its diagnosis by showing several findings, i.e., gray/brownish dots in linear arrangement, scales, coiled vessels, focal/multifocal amorphous hypopigmentation and bluish structureless areas [1,2]. However, pBD may sometimes display dermoscopic features which are typical of other pigmented lesions, thus making its recognition quite troublesome despite the use of dermoscopy [1,2]. We report a case of pBD with a "starburst" pattern, discussing its dermoscopic differential diagnosis.

  2. The analysis of pigments on rock surfaces

    International Nuclear Information System (INIS)

    Fankhauser, B.; O'Connor, S.; Pittelkow, Y.

    1997-01-01

    A limestone slab of roof fall coated with a red pigment was recovered from a Rockshelter in the Napier Ranges of the Kimberley region, Western Australia. Next to the roof fall fragment in the same stratigraphic layer was a piece of ochre. Three questions were presented: (1) is the red substance an ochre? (2) is the piece of ochre identical to the red substance on the roof fall? and (3) are the layers of pigment on the top and bottom of the limestone slab the same? In addition, as an extension from these questions, a general method was developed for the in situ analysis of ochre pigments on substrates to determine likely compositions and ochre sources. The analysis of the red pigment presented an analytical problem because the substance was intimately associated with the rock slab and therefore the analysis had to be done in situ. Not only was the red layer thin, but on a micro level it was uneven. Energy dispersive x-ray analysis (EDXA) penetrated the red layer, simultaneously analysing this layer and the rock substrate to different degrees depending upon the thickness of the red layer. Determining if the substance was actually ochre involved a comparison of elemental analyses between the background (slab) and background with red coating. Coatings of other ochres with known elemental concentrations on the same limestone background gave a comparison of the effect of simultaneously analysing a thin layer and background with different compositions. Three graphical methods useful for insitu analysis are demeonstrated. The find dates (around 40,000 BP) add to a growing body of data in support of the widespread use of ochre accompanying the earliest documented use of widely separated and environmentally diverse regions of Australia by Aboriginal people

  3. Nano-scale experimental investigation of in-situ wettability and spontaneous imbibition in ultra-tight reservoir rocks

    Science.gov (United States)

    Akbarabadi, Morteza; Saraji, Soheil; Piri, Mohammad; Georgi, Dan; Delshad, Mohammad

    2017-09-01

    We investigated spontaneous imbibition behavior, three-dimensional fluid occupancy maps, and in-situ wettability at the nano scale in five ultra-tight and shale reservoir rock samples. For this purpose, we developed a novel technique by integrating a custom-built in-situ miniature fluid-injection module with a non-destructive high-resolution X-ray imaging system. Small cylindrical core samples (15-60 μm in diameter) were prepared from reservoir rocks using Focused-Ion Beam (FIB) milling technique. The pore network inside the samples were first characterized using ultra-high resolution three-dimensional images obtained at initial state by X-ray nano-tomography (Nano-CT) and FIB-Scanning Electron Microscopy (FIB-SEM) techniques at the nano scale. The petrophysical parameters, including porosity, permeability, pore-size distribution, and organic content were computed for each sample using image analysis. We then performed series of imbibition experiments using brine, oil, and surfactant solutions on each core sample. We observed that both oil and brine phases spontaneously imbibe into the pore network of the rock samples at various quantities. We also, for the first time, examined fluid distribution in individual pores and found a complex wettability behavior at the pore scale in the reservoir rock samples. Three pore types were identified with water-wet, oil-wet, and fractionally-wet behaviors. This work opens a new path to developing an improved understanding of the pore-level physics involved in multi-phase flow and transport not only in tight rock samples but also in other nanoporous material used in different science and engineering applications.

  4. In situ transmission electron microscopy investigation of quasicrystal-crystal transformations in Mg–Zn–Y alloys

    Energy Technology Data Exchange (ETDEWEB)

    Liu, J.F.; Yang, Z.Q., E-mail: yangzq34@yahoo.com; Ye, H.Q.

    2015-02-05

    Highlights: • Quasicrystal-to-crystal transformation sequence in Mg–Zn–Y alloys was determined. • H phase Zn{sub 3}MgY and W phase Zn{sub 3}Mg{sub 3}Y{sub 2} nucleated on icosahedral quasicrystal Zn{sub 6}Mg{sub 3}Y. • Growth of both H and W phase is controlled by diffusion. • The close relationship between building units plays a key role in the transformation. - Abstract: Evolution of icosahedral quasicrystals (IQC) in Mg–Zn–Y alloys during annealing was investigated by in situ transmission electron microscopy (TEM), in combination with differential thermal analysis and X-ray diffraction. In bulk samples, the IQC phase transformed to face-centered cubic phase W and hexagonal phase H at 720 K and 727 K, respectively. In TEM samples, IQC started to transform to W at 673 K and H at 688 K during heating, and H transformed to W at 623 K on cooling. Quantitative analysis of the in situ transformation process reveals that growth of both H and W is controlled by diffusion, agreeing with the Avrami’s model. The transformed products have specific orientation relationships with the parent phases: 3-fold{sub IQC}//[0 0 0 1]{sub H}//[1 1 1]{sub W} and 2-fold{sub IQC}//112{sup ¯}0]{sub H}//[01{sup ¯}1]{sub W}. The specific orientation relationships are attributed to close structural correlation among icosahedron, distorted icosahedron and cuboctahedron in IQC, H and W phases. The close structure relationship among IQC, H and W phases on the unit-cell level plays an important role in the phase transformations.

  5. Electrochemical and spectroscopic in situ techniques for the investigation of the phosphating of zinc coated steel

    International Nuclear Information System (INIS)

    Tomandl, A.

    2003-05-01

    In this work spectroscopic and electrochemical techniques were developed for the investigation of surface treatments used in steel industry. ICP-atomic emission spectroscopy (ICP-AES), Raman spectroscopy and the Quartz crystal microbalance (QCM) were applied to the investigation of the kinetics of phosphating as well as the properties of phosphate layers. Phosphating of zinc coated steel leads to the formation of a crystalline layer consisting of zinc phosphate and is employed to enhance paint adhesion and corrosion protection. For the high reaction rates necessary in industrial production lines, oxidation agents are added to the phosphating bathes to accelerate the reaction. The oxidation agents provide an additional reduction reaction beside the hydrogen formation and therefore decrease the number of gas bubbles, which would block the zinc surface and reduce the rate of phosphating. With addition of H2O2 or nitrates the rate of layer formation is distinctly increased. In a combined experiment of ICP-AES with QCM and potential transients, it was shown that the presence of these accelerators in the phosphating bath increases the rate of zinc dissolution and hence leads to a faster formation of the phosphate layer. In under paint corrosion of painted, zinc coated steel phosphate layers are exposed to a highly alkaline environment. The stability of a phosphate layer against alkaline attack is therefore essential for its performance in corrosion protection. To enhance the alkaline stability Mn and Ni are added to modern phosphating bathes. The incorporation of these elements reduces the dissolution rate in 0.1 M NaOH proportional to their concentration in the phosphate layer. The dissolution of Zn, P, Mn and Ni was determined quantitatively with ICP-AES. Raman spectroscopy showed the formation of a Mn-hydroxide layer during alkaline attack, which protects the phosphate layer and reduces further dissolution. On basis of these results the reaction of phosphate layers

  6. Nanosecond time-resolved investigations using the in situ of dynamic transmission electron microscope (DTEM)

    International Nuclear Information System (INIS)

    LaGrange, Thomas; Campbell, Geoffrey H.; Reed, B.W.; Taheri, Mitra; Pesavento, J. Bradley; Kim, Judy S.; Browning, Nigel D.

    2008-01-01

    Most biological processes, chemical reactions and materials dynamics occur at rates much faster than can be captured with standard video rate acquisition methods in transmission electron microscopes (TEM). Thus, there is a need to increase the temporal resolution in order to capture and understand salient features of these rapid materials processes. This paper details the development of a high-time resolution dynamic transmission electron microscope (DTEM) that captures dynamics in materials with nanosecond time resolution. The current DTEM performance, having a spatial resolution <10 nm for single-shot imaging using 15 ns electron pulses, will be discussed in the context of experimental investigations in solid state reactions of NiAl reactive multilayer films, the study of martensitic transformations in nanocrystalline Ti and the catalytic growth of Si nanowires. In addition, this paper will address the technical issues involved with high current, electron pulse operation and the near-term improvements to the electron optics, which will greatly improve the signal and spatial resolutions, and to the laser system, which will allow tailored specimen and photocathode drive conditions

  7. Oxygen diluted hexamethyldisiloxane plasmas investigated by means of in situ infrared absorption spectroscopy and mass spectrometry

    Science.gov (United States)

    Magni, D.; Deschenaux, Ch; Hollenstein, Ch; Creatore, A.; Fayet, P.

    2001-01-01

    The gas phase species produced in rf plasmas of hexamethyldisiloxane (HMDSO), Si2O(CH3)6, diluted with oxygen, have been investigated. The complementarity of Fourier transform infrared absorption spectroscopy and mass spectrometry allows the determination of the most abundant neutral components present in the discharge. The measurements reveal that methyl groups (CH3), abundantly formed by the dissociation of the HMDSO molecule, are the precursor for the most abundant species which stem from two kinds of reaction. The first kind of reaction is combustion of CH3 by oxygen-producing formaldehyde (COH2), formic acid (CO2H2), carbon monoxide (CO), carbon dioxide (CO2) and water. It is shown that high mass carbonated radicals, such as SixOyCzHt, first diffuse to the surface and then the carbon is removed by oxygen etching to form CO2. The second is hydrocarbon chemistry promoted by CH3, producing mainly hydrogen (H2), methane (CH4) and acetylene (C2H2).

  8. Pigments and oligomers for inks - moving towards the best combination

    International Nuclear Information System (INIS)

    Hutchinson, I.; Smith, S.; Grierson, W.; Devine, E.

    1999-01-01

    The formulation of UV curable printing inks depends on several complex factors. If the individual components of the ink are not complementary, then performance problems can arise. One critical combination is that between the pigment and the oligomer. In a new approach to improve understanding of pigment/oligomer interactions, the resources of a pigment manufacturer and an oligomer manufacturer have been combined to investigate the problem. Initial screening of process yellow pigments and several oligomer types highlighted performance variations which were then examined in more detail

  9. Raman scattering features of lead pyroantimonate compounds: implication for the non-invasive identification of yellow pigments on ancient ceramics. Part II. In situ characterisation of Renaissance plates by portable micro-Raman and XRF studies

    Czech Academy of Sciences Publication Activity Database

    Rosi, F.; Manuali, V.; Grygar, Tomáš; Bezdička, Petr; Brunetti, B.G.; Sgamellotti, A.; Burgio, L.; Seccaroni, C.; Miliani, C.

    2011-01-01

    Roč. 42, č. 3 (2011), s. 407-414 ISSN 0377-0486 Institutional research plan: CEZ:AV0Z40320502 Keywords : Naples yellow * lead antimonate * cubic pyrochlore * non-invasive * in situ Subject RIV: DD - Geochemistry Impact factor: 3.087, year: 2011

  10. Investigation of fracture conductivity under in situ conditions as a function of frac- and formation parameters

    Energy Technology Data Exchange (ETDEWEB)

    Meyn, V.; Lajcsak, I.

    1998-10-01

    Because of their low permeability, deep-lying gas fields are often developed by the fracturing technique. Essential for the economy of this measure is a high fracture conductivity which persists over a long period. The objective of the project was the investigation of the various factors influencing the fracture conductivity under reservoir conditions. Besides the breaking strength of proppants, which is decisive for the conductivity attainable at high confining pressure, the long-term stability, the embedment and the transport of fragments, which results in plugging, were examined. With the proppants Superprop and Carboprop HC, fracture conductivity exhibits only a slight dependence on the closure pressure. Transport of fragments and embedment play no important role. With resin-coated proppants, conductivity is not improved appreciably. The resin-coating doesn`t resist reservoir conditions. After only one week, aquathermolytic products were detected. (orig.) [Deutsch] Tiefliegende Erdgasfelder werden aufgrund ihrer niedrigen Permeabilitaet haeufig durch eine Frac-Behandlung erschlossen. Eine wesentliche Voraussetzung fuer die Wirtschaftlichkeit einer solchen Massnahme ist eine hohe Rissleitfaehigkeit, die ueber einen langen Zeitraum bestehen bleibt. Ziel des Projektes war die Untersuchung der verschiedenen Faktoren, die die Rissleitfaehigkeit unter Lagerstaettenbedingungen beeinflussen. Neben der Bruchfestigkeit des Stuetzmittels, die fuer die bei hohen Schliessdrucken erreichbaren Rissleitfaehigkeiten entscheidend ist, wurde die Langzeitstabilitaet, das Embedment und der zu Verstopfung fuehrende Transport von Bruchstuecken untersucht. Die Stuetzmittel Superprop und Carboprop HC weisen nur eine geringe Abhaengigkeit der Rissleitfaehigkeit vom Schliessdruck auf. Der Bruchstuecktransport sowie das Embedment spielen nur eine untergeordnete Rolle. Durch die Verwendung von beschichtetem Stuetzmittel wird die Rissleitfaehigkeit nicht wesentlich erhoeht. Die Beschichtung

  11. In Situ Strategy of the 2011 Mars Science Laboratory to Investigate the Habitability of Ancient Mars

    Science.gov (United States)

    Mahaffy, Paul R.

    2011-01-01

    The ten science investigations of the 2011 Mars Science Laboratory (MSL) Rover named "Curiosity" seek to provide a quantitative assessment of habitability through chemical and geological measurements from a highly capable robotic' platform. This mission seeks to understand if the conditions for life on ancient Mars are preserved in the near-surface geochemical record. These substantial payload resources enabled by MSL's new entry descent and landing (EDL) system have allowed the inclusion of instrument types nevv to the Mars surface including those that can accept delivered sample from rocks and soils and perform a wide range of chemical, isotopic, and mineralogical analyses. The Chemistry and Mineralogy (CheMin) experiment that is located in the interior of the rover is a powder x-ray Diffraction (XRD) and X-ray Fluorescence (XRF) instrument that provides elemental and mineralogical information. The Sample Analysis at Mars (SAM) suite of instruments complements this experiment by analyzing the volatile component of identically processed samples and by analyzing atmospheric composition. Other MSL payload tools such as the Mast Camera (Mastcam) and the Chemistry & Camera (ChemCam) instruments are utilized to identify targets for interrogation first by the arm tools and subsequent ingestion into SAM and CheMin using the Sample Acquisition, Processing, and Handling (SA/SPaH) subsystem. The arm tools include the Mars Hand Lens Imager (MAHLI) and the Chemistry and Alpha Particle X-ray Spectrometer (APXX). The Dynamic Albedo of Neutrons (DAN) instrument provides subsurface identification of hydrogen such as that contained in hydrated minerals

  12. Areas and limits of employment of portable EDXRF equipment for in situ investigations

    International Nuclear Information System (INIS)

    Gigante, G.E.; Ricciardi, P.; Ridolfi, St.

    2005-01-01

    The use of mobile spectrometers in the archaeo-metric study of ancient artefacts has become a very common practice over the past few years. It does open methodological questions on the employment of such techniques in a non-destructive manner, i.e. avoiding the damage of the artifact. Some additional methodological questions come by (i) the use of such instrumentation for diagnostic scopes (in which a different approach to the measurement is required) and (ii) the use of the spectrometers in systematic analysis on big number of artefacts, stored in several museums (during experimental campaigns). This paper's aim is to discuss some of this questions, on the basis of the experience in the use of mobile (or Field Portable) systems for Energy Dispersive X-ray Fluorescence (EDXRF) spectroscopy that we have harvested in the last years. Our conclusions mainly regard the precision of measures, which is related both to the positioning of the spectrometer and to the instrument's instability. Also we deal with the more complex problem of the object's matrix not being homogeneous and of how this can affect the response of the measuring system. Moreover, it is discussed the more general question of the use of portable spectrometers and, consequently, of the meaning one can give to the results so obtained. As a matter of fact the use of such systems, which have an intrinsic analytic potential, in a non-destructive manner, frequently creates ambiguities that have not been, sometimes, taken into account with attention by the investigators. Finally some ideas are traced on the development of methodologies which favor a better use of such spectroscopic systems for the analysis of ancient artefacts. (authors)

  13. True bursal pigmented villonodular synovitis

    International Nuclear Information System (INIS)

    Abdelwahab, Ibrahim Fikry; Kenan, Samuel; Steiner, German C.; Abdul-Quader, Mohammed

    2002-01-01

    We describe two cases of pigmented villonodular synovitis affecting true bursae. This study was also designed to discuss the term ''pigmented villonodular bursitis'', not confined to true synovial bursae, sometimes creating misunderstanding. (orig.)

  14. True bursal pigmented villonodular synovitis

    Energy Technology Data Exchange (ETDEWEB)

    Abdelwahab, Ibrahim Fikry [Department of Radiology, New York Methodist Hospital, Affiliated with New York Hospital-Cornell Medical Center, Brooklyn, NY (United States); Kenan, Samuel [Department of Orthopedics, New York University Medical Center, NY (United States); Steiner, German C. [Department of Pathology, Hospital for Joint Diseases/Orthopedic Institute, New York, NY (United States); Abdul-Quader, Mohammed [Department of Radiology, New York Presbyterian Hospital, Columbia University, New York, NY (United States)

    2002-06-01

    We describe two cases of pigmented villonodular synovitis affecting true bursae. This study was also designed to discuss the term ''pigmented villonodular bursitis'', not confined to true synovial bursae, sometimes creating misunderstanding. (orig.)

  15. An in-situ analytical scanning and transmission electron microscopy investigation of structure-property relationships in electronic materials

    Science.gov (United States)

    Wagner, Andrew James

    photovoltaic performance. The annealing process, however, requires exceptionally high temperature (> 600 °C) and time (tens of hours), limiting throughput and costing energy. In an effort to fabricate polycrystalline solar cells at lower cost, large ( 30 nm) silicon nanocrystals were incorporated into hydrogenated amorphous silicon (a Si:H) thin films. When annealed, the embedded nanocrystals were expected to act as heterogeneous nucleation sites and crystallize the surrounding amorphous matrix. When observed in the TEM, an additional and unexpected event was observed. At the boundary between the nanocrystal and amorphous matrix, nanocavities were observed to form. Continued annealing resulted in movement of the cavities away from the nanocrystal while leaving behind a crystalline tail. The origins and fundamental mechanisms of this phenomenon were examined by in-situ heating TEM and ex-situ crystallographic TEM techniques. We demonstrate a mechanism of solid-phase crystallization (SPC) enabled by nanoscale cavities formed at the interface between an hydrogenated amorphous silicon film and embedded 30 nm to 40 nm Si nanocrystals. The nanocavities, 10 nm to 25 nm across, have the unique property of an internal surface that is part amorphous and part crystalline, enabling capillarity-driven diffusion from the amorphous to the crystalline domain. The nanocavities propagate rapidly through the amorphous phase, up to five times faster than the SPC growth rate, while "pulling behind" a crystalline tail. It is shown that twin boundaries exposed on the crystalline surface accelerate crystal growth and influence the direction of nanocavity propagation. The mechanical properties and mechanisms of plasticity in these same silicon nanocubes have also been investigated. The strain-dependent mechanical properties and the underlying mechanisms governing the elastic-plastic response are explored in detail. Elastic strains approaching 7% and flow stresses of 11 GPa were observed

  16. Betalain: a particular class of antioxidant pigment.

    Science.gov (United States)

    El Gharras, Hasna

    2011-10-01

    We have analyzed the stability of betalains in juices prepared from Moroccan yellow cactus pears (Opuntia ficus indica (L.) Mill.) as a function of temperature and pH. The experiments were carried out at temperatures ranging from 80 to 100 degrees C with juices at pH 3.5, 5 and 6.5. The degree of pigment retention decreased when the temperature increased. The degradation constant rates were determined for thermal degradation rates of pseudo-first order. The Arrhenius plot obtained for the degradation of betaxanthin from the yellow fruits was not linear. Regardless of the temperature of treatment, the lowest degradation was obtained for pH 5. When some stabilizers were tested for the protection of pigments, the results showed that ascorbic acid was a better protective agent at pH 3.5, increasing the protection by 40%. The inhibitive action of betalain pigments extracted from cactus pears towards corrosion of stainless steel in phosphoric acid was investigated using electrochemical polarization and electrochemical impedance spectroscopy (EIS) methods. It was found that the presence of natural pigments reduces the corrosion rate of the tested metal, especially on addition of the red pigments (97%). The inhibition efficiency increases as the pigment concentration of extracts increases. It was also found that the pigments tested act as mixed inhibitors. The inhibitive action of the extracts is discussed in term of adsorption and that such adsorption follows a Langmuir adsorption isotherm. The calculated values of the free energy of adsorption indicated that the adsorption process is spontaneous.

  17. Phototrophic pigment production with microalgae

    NARCIS (Netherlands)

    Mulders, K.J.M.

    2014-01-01

    Abstract

    Microalgal pigments are regarded as natural alternatives for food colorants. To facilitate optimization of microalgae-based pigment production, this thesis aimed to obtain key insights in the pigment metabolism of phototrophic microalgae, with the main focus on secondary

  18. Phototrophic pigment production with microalgae

    NARCIS (Netherlands)

    Mulders, K.J.M.

    2014-01-01

    Abstract

    Microalgal pigments are regarded as natural alternatives for food colorants. To facilitate optimization of microalgae-based pigment production, this thesis aimed to obtain key insights in the pigment metabolism of phototrophic microalgae, with the main  focus

  19. Skin Pigmentation Kinetics after Exposure to Ultraviolet A

    DEFF Research Database (Denmark)

    Ravnbak, M.H.; Philipsen, P.A.; Wiegell, S.R.

    2009-01-01

    Multiple exposures to ultraviolet radiation (UVR) are the norm in nature and phototherapy. However, studies of the kinetics of pigmentation following UVA exposure have included only fair-skinned persons. The aim of this study was to investigate steady-state pigmentation and fading in 12...

  20. Anti-corrosion properties of coatings with manganese compounds pigmentation

    Science.gov (United States)

    Ziganshina, M.; Nurislamova, E.

    2018-02-01

    Work investigates properties of corrosion-resistant coatings based on organic-aqueous emulsion and pigmented compounds of manganese, obtained by ceramic method. It is found that the inclusion of synthesized pigments in the composition of the coating increases their ability to inhibit underfilm corrosion of steel.

  1. Optimization of fermentation conditions for red pigment production ...

    African Journals Online (AJOL)

    An extracellular pigment-producing ascomycetous filamentous fungi belonging to the genera Penicillium was obtained from soil and its optimal culture conditions investigated. The optimal culture conditions for pigment production were as follows; soluble starch 2% (670 units), peptone (880 units), pH 9.0 (900 units); ...

  2. Pigment Production by the Edible Filamentous Fungus Neurospora Intermedia

    Directory of Open Access Journals (Sweden)

    Rebecca Gmoser

    2018-02-01

    Full Text Available The production of pigments by edible filamentous fungi is gaining attention as a result of the increased interest in natural sources with added functionality in the food, feed, cosmetic, pharmaceutical and textile industries. The filamentous fungus Neurospora intermedia, used for production of the Indonesian food “oncom”, is one potential source of pigments. The objective of the study was to evaluate the fungus’ pigment production. The joint effect from different factors (carbon and nitrogen source, ZnCl2, MgCl2 and MnCl2 on pigment production by N. intermedia is reported for the first time. The scale-up to 4.5 L bubble column bioreactors was also performed to investigate the effect of pH and aeration. Pigment production of the fungus was successfully manipulated by varying several factors. The results showed that the formation of pigments was strongly influenced by light, carbon, pH, the co-factor Zn2+ and first- to fourth-order interactions between factors. The highest pigmentation (1.19 ± 0.08 mg carotenoids/g dry weight biomass was achieved in a bubble column reactor. This study provides important insights into pigmentation of this biotechnologically important fungus and lays a foundation for future utilizations of N. intermedia for pigment production.

  3. Multiscale Pigment Analysis of Medieval Illuminated Manuscripts

    Science.gov (United States)

    Sestak, Erica; Manukyan, Khachatur; Wiescher, Michael; Gura, David

    2017-09-01

    Three medieval illuminated manuscripts (codd. Lat. b. 1; Lat. b. 2; Lat. e. 4), housed at the University of Notre Dame's Hesburgh Library, vary in style, pigments, scribes, and regions, despite all three being Psalters used in the Late Middle Ages. XRF and Raman spectroscopy, which provided the elemental and molecular composition of the pigments, respectively, were used to analyze the pigments' compositions in an attempt to narrow further the manuscripts' possible origins. This experimental investigation emphasizes the importance of understanding the history of the manuscript through their pigments. Codd. Lat. b. 1 and Lat. b. 2 are Latinate German Psalters from the fifteenth century likely used in Katharinenkloster in Nuremberg. While there are visible differences in style within each Psalter, the variations in some of the pigment compositions, such as the inconstant presence of zinc, suggest different admixtures. Cod. Lat. e. 4 is a Latinate English Psalter from the fourteenth century, and it was written by two scribes and illuminated by two distinct painters. It is currently being tested to determine whether there are any correlations between the scribes and painters. These physical analyses will clarify the origins and provenances of the manuscripts.

  4. Investigating Kinetic Pathways During Solvent Vapor Annealing with Soft Shear via In Situ Small-Angle Neutron Scattering

    Science.gov (United States)

    Shelton, Cameron; Jones, Ronald; Epps, Thomas

    Solvent vapor annealing with soft shear (SVA-SS) is a block polymer (BP) thin film annealing technique that directionally aligns nanostructures by exploiting solvent swelling/deswelling differences between the film and a polydimethylsiloxane (PDMS) pad adhered to the free surface. Although studies have demonstrated the potential of SVA-SS to generate well-aligned domains, the restructuring mechanism and effect of key parameters requires investigation to improve control over self-assembly. In this work, we conducted in situ small-angle neutron scattering experiments to explore the kinetic pathways of nanostructure alignment of poly(d-styrene-b-isoprene-b-d-styrene) thin films during SVA-SS. We compared results to SVA (without shear) and determined that alignment occurred through domain breakup and reformation initiated by PDMS swelling and deswelling, respectively. Additionally, changes in parameters such as PDMS elasticity and deswell rate resulted in nonlinear trends in domain directionality and ordering that were not apparent by small-area atomic force microscopy analysis. By relating the key thermodynamic effects to measured kinetic pathways for alignment, we have generated a more optimized approach to direct BP thin film self-assembly using SVA-SS.

  5. In Situ Investigation the Photolysis of the PAHs Adsorbed on Mangrove Leaf Surfaces by Synchronous Solid Surface Fluorimetry

    Science.gov (United States)

    Wang, Ping; Wu, Tun-Hua; Zhang, Yong

    2014-01-01

    An established synchronous solid surface fluorimetry (S-SSF) was utilized for in situ study the photolysis processes of anthracene (An) and pyrene (Py) adsorbed on the leaf surfaces of Kandelia obovata seedlings (Ko) and Aegiceras corniculata (L.) Blanco seedlings (Ac). Experimental results demonstrated that the photolysis of An and Py adsorbed on the leaf surfaces of two mangrove species under the laboratory conditions, followed first-order kinetics with their photolysis rates in the order of Ac>Ko. In addition, with the same amount of substances, the photolysis rate of An adsorbed on the same mangrove leaf surfaces was much faster than the adsorbed Py. In order to investigate further, the photolysis processes of An and Py in water were also studied for comparison. And the photolysis of An and Py in water also followed first-order kinetics. Moreover, for the same initial amount, the photolysis rate of the PAH in water was faster than that adsorbed on the leaf surfaces of two mangrove species. Therefore, photochemical behaviors of PAHs were dependent not only on their molecular structures but also the physical-chemical properties of the substrates on which they are adsorbed. PMID:24404158

  6. In situ electrochemical-mass spectroscopic investigation of solid electrolyte interphase formation on the surface of a carbon electrode

    International Nuclear Information System (INIS)

    Gourdin, Gerald; Zheng, Dong; Smith, Patricia H.; Qu, Deyang

    2013-01-01

    The energy density of an electrochemical capacitor can be significantly improved by utilizing a lithiated negative electrode and a high surface area positive electrode. During lithiation of the negative carbon electrode, the electrolyte reacts with the electrode surface and undergoes decomposition to form a solid electrolyte interphase (SEI) layer that passivates the surface of the carbon electrode from further reactions between Li and the electrolyte. The reduction reactions that the solvent undergoes also form insoluble and gaseous by-products. In this work, those gaseous by-products generated by reductive decomposition of a carbonate-based electrolyte, 1.2 M LiPF 6 in EC/PC/DEC (3:1:4), were analyzed at different stages during the lithiation process of an amorphous carbon electrode. The stages in the generation of gaseous by-products were determined to come as a result of two, 1-electron reduction steps of the cyclic carbonate components of the electrolyte. Electrochemical impedance spectroscopy was also used to investigate the two distinct electrochemical processes and the development of the two phases of the SEI structure. This is the first time that the state of an electrochemical cell during the formation of the SEI layer has been systematically correlated with theoretical reaction mechanisms through the use of in situ electrochemical-MS and impedance spectroscopy analyses

  7. Preliminary investigation of the potential for transient vapor release events during in situ vitrification based on thermal- hydraulic modeling

    International Nuclear Information System (INIS)

    Roberts, J.S.; Woosley, S.L.; Lessor, D.L.; Strachan, C.

    1992-07-01

    This study investigates a possible cause of molten glass displacements that occurred during two recent in situ vitrification (ISV) tests. The study was conducted for the US Department of Energy by Pacific Northwest Laboratory. It is hypothesized that these glass displacements are caused by large gas bubbles rising up through the ISV melt and bursting at its surface. These bubbles cause the molten surface to upwell and possibly overflow. When the bubbles burst, molten glass is thrown from the melt surface and the volume of gas contained in the bubble is released into the hood. Both of these phenomena are undesirable because the molten soil ejected from the melt is dangerous to operating personnel and can damage equipment. The sudden gas release can cause a temporary pressurization of the hood, allowing potentially contaminated gas to escape to the atmosphere. This study attempts to explain the conditions necessary for formation of large gas bubbles in the melt so that future glass displacements can be avoided

  8. Preliminary investigation of the potential for transient vapor release events during in situ vitrification based on thermal- hydraulic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, J.S.; Woosley, S.L.; Lessor, D.L.; Strachan, C.

    1992-07-01

    This study investigates a possible cause of molten glass displacements that occurred during two recent in situ vitrification (ISV) tests. The study was conducted for the US Department of Energy by Pacific Northwest Laboratory. It is hypothesized that these glass displacements are caused by large gas bubbles rising up through the ISV melt and bursting at its surface. These bubbles cause the molten surface to upwell and possibly overflow. When the bubbles burst, molten glass is thrown from the melt surface and the volume of gas contained in the bubble is released into the hood. Both of these phenomena are undesirable because the molten soil ejected from the melt is dangerous to operating personnel and can damage equipment. The sudden gas release can cause a temporary pressurization of the hood, allowing potentially contaminated gas to escape to the atmosphere. This study attempts to explain the conditions necessary for formation of large gas bubbles in the melt so that future glass displacements can be avoided.

  9. In situ investigation of the long-term sealing system as component of dam construction (Dam project)

    International Nuclear Information System (INIS)

    1995-01-01

    The project ''In situ investigation of the long term sealing system as a component of a Dam Construction'' started on April 1991. The main objectives of the research to be developed by DIT-UPC group is to model and validate the effects of multiphase flow through the components of the long-term seal and at the interface between the seal and the host rock. These include the following main tasks: -Task 1: State of the art-review -Task 2: Laboratory work -Task 3: Modelling -Task 4: Code verification -Task 5: Validation From these tasks, the main research directions that have been followed are: Constitutive modelling of the mechanical behaviour of porous salt aggregates. Development of a theoretical framework for the study and charaterization of the coupled hydro-thermo-mechanical behaviour of a porous/non-porous saline system. This includes both, establishing the governing equations and the adoption of constitutive laws. The final objective is the development of a numerical simulator able to handle problems in saline environments

  10. In-situ investigation of the hydrogen release mechanism in bulk Mg2NiH4

    Science.gov (United States)

    Tran, Xuan Quy; McDonald, Stuart D.; Gu, Qinfen; Yamamoto, Tomokazu; Shigematsu, Koji; Aso, Kohei; Tanaka, Eishi; Matsumura, Syo; Nogita, Kazuhiro

    2017-02-01

    Hydrogen storage is an important aspect to enable the so-called hydrogen economy. Mg-Ni alloys are among the most promising candidates for solid-state hydrogen storage systems yet many questions remain unanswered regarding the hydriding/dehydriding mechanism of the alloys. Mg2NiH4 particularly has received much attention both for its potential as a hydrogen storage medium and also exhibits interesting properties relating to its different polymorphs. Here, the dehydriding mechanism in bulk Mg2NiH4 is investigated using in-situ ultra-high voltage transmission electron microscopy (TEM) combined with Synchrotron powder X-ray diffraction (XRPD) and differential scanning calorimetry (DSC). We find that the hydrogen release is based on a mechanism of nucleation and growth of Mg2NiHx (x∼0-0.3) solid solution grains and is greatly enhanced in the presence of crystal defects occurring as a result of the polymorphic phase transformation. Also importantly, with atomic resolution TEM imaging a high density of stacking faults is identified in the dehydrided Mg2NiHx (x∼0-0.3) lattices.

  11. Electronic excitation induced defect dynamics in HfO2 based MOS devices investigated by in-situ electrical measurements

    Science.gov (United States)

    Manikanthababu, N.; Vajandar, S.; Arun, N.; Pathak, A. P.; Asokan, K.; Osipowicz, T.; Basu, T.; Nageswara Rao, S. V. S.

    2018-03-01

    In-situ I-V and C-V characterization studies were carried out to determine the device quality of atomic layer deposited HfO2 (2.7 nm)/SiO2 (0.6 nm)/Si-based metal oxide semiconductor devices during 120 MeV Ag ion irradiation. The influence of various tunneling mechanisms has been investigated by analyzing the I-V characteristics as a function of ion fluence. The nature of the defects created is tentatively identified by the determination of the significant tunneling processes. While the ion induced annealing of defects is observed at lower fluences, ion induced intermixing and radiation damage is found to be significant at higher fluences. The C-V characteristics also reveal significant changes at the interface and oxide trap densities: an increase in the oxide layer thickness occurs through the formation of an HfSiO interlayer. The interlayer is due to the swift heavy ion induced intermixing, which has been confirmed by X-TEM and X-ray photoelectron spectroscopy measurements.

  12. Comparative investigation of underpotential deposition of Ag from aqueous and ionic electrolytes: An electrochemical and in situ STM study.

    Science.gov (United States)

    Borissov, D; Aravinda, C L; Freyland, W

    2005-06-16

    Underpotential deposition (UPD) of Ag on Au(111) has been studied with two different electrolytes: aqueous 0.1 M H2SO4 solution in comparison with the ionic liquid 1-butyl-3-methylimidazolium chloride BMICl + AlCl3. Of particular interest is the distinct behavior of 2D phase formation at both interfaces, which has been investigated by cyclic and linear sweep voltammetry in combination with in situ electrochemical scanning tunneling microscopy (STM). It is found that one monolayer (ML) of Ag is formed in the UPD region in both electrolytes. In aqueous solution, atomically resolved STM images at 500 mV versus Ag/Ag+ show a (3 x 3) adlayer of Ag, whereas after sweeping the potential just before the commencement of the bulk Ag deposition, a transition from expanded (3 x 3) to pseudomorphic ML of Ag on Au(111) occurs. In BMICl-AlCl3, the first UPD process of Ag exhibits two peaks at 410 and 230 mV indicating that two distinct processes on the surface take place. For the first time, STM images with atomic resolution reveal a transition from an inhomogeneous to an ordered phase with a (square root of 3 x square root of 3)R30 degrees structure and an adsorption of AlCl4- anions having a superlattice of (1.65 x square root of 3)R30 degrees preceding the deposition of Ag.

  13. Reduction of Sr2MnO4 investigated by high temperature in situ neutron powder diffraction under hydrogen flow.

    Science.gov (United States)

    Broux, Thibault; Bahout, Mona; Hernandez, Olivier; Tonus, Florent; Paofai, Serge; Hansen, Thomas; Greaves, Colin

    2013-01-18

    This experiment emphasizes the first example of two-phase sequential Rietveld refinements throughout a solid/gas chemical reaction monitored by Neutron Powder Diffraction (NPD) at high temperature. The reduction of the n = 1 Ruddlesden-Popper (RP) oxide Sr(2)MnO(4) heated under a flow of 5% H(2)-He has been investigated throughout two heating/cooling cycles involving isothermal heating at 500 and 550 °C. Oxygen loss proceeds above T ∼ 470 °C and increases with temperature and time. When the oxygen deintercalated from the "MnO(2)" equatorial layers of the structure results in the Sr(2)MnO(3.69(2)) composition, the RP phase undergoes a first order I4/mmm → P2(1)/c, tetragonal to monoclinic phase transition as observed from time-resolved in situ NPD. The phase transition proceeds at 500 °C but is incomplete; the weight ratio of the P2(1)/c phase reaches ∼41% after 130 min of isothermal heating. The fraction of the monoclinic phase increases with increasing temperature and the phase transition is complete after 80 min of isothermal heating at 550 °C. The composition of the reduced material refined to Sr(2)MnO(3.55(1)) and does not vary on extended heating at 550 °C and subsequent cooling to room temperature (RT). The symmetry of Sr(2)MnO(3.55(1)) is monoclinic at 550 °C and therefore consistent with the RT structure determined previously for the Sr(2)MnO(3.64) composition obtained from ex situ reduction. Consequently, the stresses due to phase changes on heating/cooling in reducing atmosphere may be minimized. The rate constants for the reduction of Sr(2)MnO(4.00) determined from the evolution of weight ratio of the tetragonal and monoclinic phase in the time-resolved isothermal NPD data collected on the isotherms at 500 and 550 °C are k(500) = 0.110 × 10(-2) and k(550) = 0.516 × 10(-2) min(-1) giving an activation energy of ∼163 kJ mol(-1) for the oxygen deintercalation reaction.

  14. In Situ Investigation of the Evolution of Lattice Strain and Stresses in Austenite and Martensite During Quenching and Tempering of Steel

    DEFF Research Database (Denmark)

    Villa, M.; Niessen, F.; Somers, M. A. J.

    2018-01-01

    Energy dispersive synchrotron X-ray diffraction was applied to investigate in situ the evolution of lattice strains and stresses in austenite and martensite during quenching and tempering of a soft martensitic stainless steel. In one experiment, lattice strains in austenite and martensite were me...

  15. Interactions between Lattice Dislocations and Grain Boundaries in Ni3Al Investigated by Means of In Situ TEM and Computer Modelling Experiments

    NARCIS (Netherlands)

    Pestman, B.J.; Hosson, J.Th.M. De

    1992-01-01

    The interaction between lattice dislocations and grain boundaries in Ni3Al has been investigated by means of in situ TEM deformation experiments. The interaction between screw dislocations and a coherent twin boundary could be analyzed in detail. The interaction mechanism found experimentally was

  16. Investigation of the Lobular Carcinoma in Situ, Using Molecular Genetic Techniques, for the Involvement of Novel Genes

    National Research Council Canada - National Science Library

    Mastracci, Teresa

    2004-01-01

    Atypical lobular hyperplasia (ALH) and lobular carcinoma in situ (LCIS), i.e. lobular neoplasia (LN), are lesions of significance in terms of implication to the patient in the development of invasive carcinoma...

  17. Investigation of the Lobular Carcinoma in Situ, Using Molecular Genetic Techniques, for the Involvement of Novel Genes

    National Research Council Canada - National Science Library

    Mastracci, Teresa L; Andrulis, Irene L

    2005-01-01

    Atypical lobular hyperplasia (ALH) and lobular carcinoma in situ (LCIS), i.e. lobular neoplasia (LN), are lesions of significance in terms of risk to the patient in the development of invasive carcinoma...

  18. Pigmentos maculares Macular pigments

    Directory of Open Access Journals (Sweden)

    Renata Canovas

    2009-12-01

    Full Text Available A luteína e a zeaxantina são pigmentos amarelos que se localizam na mácula. Devido à sua localização, diminuem e filtram a quantidade de luz principalmente azul que chega aos fotorreceptores, atuam como antioxidantes e podem melhorar a qualidade visual. Esta é uma revisão do seu mecanismo de incorporação, ação, possíveis aplicações e conhecimento científico a respeito.Lutein and Zeaxanthin are yellow pigments located at the macula. Because of your location macular pigments decrease and filter the amount of blue light that reach photoreceptors, protect the outer retina from oxidative stress and may improve the vision quality. This is a review regarding incorporation mechanism, function and knowledge update.

  19. In-situ investigation of laser surface modifications of WC-Co hard metals inside a scanning electron microscope

    Science.gov (United States)

    Mueller, H.; Wetzig, K.; Schultrich, B.; Pompe, Wolfgang; Chapliev, N. I.; Konov, Vitaly I.; Pimenov, S. M.; Prokhorov, Alexander M.

    1989-05-01

    The investigation of laser interaction with solid surfaces and of the resulting mechanism of surface modification are of technical interest to optimize technological processes, and they are also of fundamental scientific importance. Most instructive indormation is available with the ail of the in-situ techniques. For instance, measuring of the photon emission of the irradiated surface ane the plasma torch (if it is produced) simultaneously to laser action, makes it possible to gain a global characterization of the laser-solid interaction. In order to obtain additional information about surface and structure modifications in microscopic detail , a laser and scanning electron microscope were combined in to a tandem equipment (LASEM). Inside this eqiipment the microscopic observation is carried out directly at the laser irradiated area without any displacement of the sample. In this way, the stepwise development of surface modification during multipulse irradiation is visible in microscopic details and much more reliable information about the surface modification process is obtainable in comparison to an external laser irradiation. Such kind of equipments were realized simultaneously and independently in the Institut of General Physics (Moscow) and the Central Institute of Solid State Physics and Material Research (Dresden) using a CO2 and a LTd-glass-laser, respectively. In the following the advantages and possibilities of a LASEM shall be demonstrated by some selected investigations of WC-CO hardmeta. The results were obtained in collaboration by both groups with the aid of the pulsed CO2-laser. The TEA CO2 laser was transmitted through a ZnSe-window into the sample chamber of the SEM and focused ofAo tfte sample surface. It was operated in TEM - oo mode with a repetition rate of about 1 pulse per second. A peak power density of about 160 MW/cm2 was achieved in front of the sample surface.

  20. Investigation of micrometre-sized fossil by laser mass spectrometer (LMS) designed for in situ space research

    Science.gov (United States)

    Tulej, Marek; Neubeck, Anna; Ivarsson, Magnus; Brigitte Neuland, Maike; Riedo, Andreas; Wurz, Peter

    2015-04-01

    Search for signatures of life on other planets is one of the most important goals of current planetary missions. Among various possible biomarkers, which can be investigated in situ on planetary surfaces, the detection of bio-relevant elements in planetary materials is of considerable interest and the abundance of isotopes can be important signatures of past and present bioactivities [1, 2]. We investigate the chemical composition of fossilised biological inclusions embedded in a carbonate host phase by a miniature laser ablation mass spectrometer (LMS) [3]. The LMS instrument combines a laser ablation ion source for ablation, atomisation and ionisation of surface material with a reflectron time-of-flight (TOF) mass spectrometer. LMS delivers mass spectra of almost all elements and their isotopes. In the current setup a fs-laser ablation ion source is applied with high lateral (15 um) and vertical (sub-um) resolution [4, 7] and the mass analyser supports mass resolution of 400-500 (at 56Fe mass peak) and dynamic range of eight orders of magnitude [5, 6]. From the 200 mass spectra recorded at 200 different locations on the carbonate sample surface, five mass spectra were identified which recorded the chemical composition of inclusions; from the other mass spectra the composition of the carbonate host matrix could be determined. The microscopic inspection of the sample surface and correlation with the coordinates of the laser ablation measurements made the confirmation to the location of the inclusion [8]. For the carbonate host matrix, the mass spectrometric analysis yielded the major elements H, C, O, Na, Mg, K and Ca and the trace elements Li, B and Cl. The measurements at the inclusion locations yielded in addition, the detection of F, Si, P, S, Mn, Fe, Ni, Co and Se. For most of the major elements the isotope ratios were found to be conform to the terrestrial values within a few per mills, while for minor and trace elements the determination of isotope ratios

  1. Changes in pigment, spectral transmission and element content of pink chicken eggshells with different pigment intensity during incubation.

    Science.gov (United States)

    Yu, Yue; Li, Zhanming; Pan, Jinming

    2016-01-01

    Objective. The objective of this study was to investigate changes in pigment, spectral transmission and element content of chicken eggshells with different intensities of pink pigment during the incubation period. We also investigated the effects of the region (small pole, equator and large pole) and pink pigment intensity of the chicken eggshell on the percent transmission of light passing through the chicken eggshells. Method. Eggs of comparable weight from a meat-type breeder (Meihuang) were used, and divided based on three levels of pink pigment (light, medium and dark) in the eggshells. During the incubation (0-21 d), the values of the eggshell pigment (ΔE, L (∗), a (∗), b (∗)) were measured. The percent transmission of light for different regions and intensities of eggshell pigmentation was measured by using the visible wavelength range of 380-780 nm. Result. Three measured indicators of eggshell color, ΔE, L (∗) and a (∗), did not change significantly during incubation. Compared with other regions and pigment intensities, eggshell at the small pole and with light pigmentation intensity showed the highest percent transmission of light. The transmission value varied significantly (P pink pigment showed that the potassium content of the eggshells for all pigment levels decreased significantly during incubation. Conclusion. In summary, pigment intensity and the region of the eggshell influenced the percent transmission of light of eggshell. Differences in the spectral characteristics of different eggshells may influence the effects of photostimulation during the incubation of eggs. All of these results will be applicable for perfecting the design of light intensity for lighted incubation to improve productivity.

  2. 75 FR 27815 - Carbazole Violet Pigment 23 From China and India; Determinations

    Science.gov (United States)

    2010-05-18

    ... (Review) Carbazole Violet Pigment 23 From China and India; Determinations On the basis of the record \\1... that revocation of the antidumping duty orders on carbazole violet pigment 23 from China and India... Publication 4151 (April 2010), entitled Carbazole Violet Pigment 23 from China and India: Investigation Nos...

  3. DNA damage in isolated rat hepatocytes exposed to C.I. pigment orange 5 and C.I. pigment yellow 12 by the alkaline comet assay

    DEFF Research Database (Denmark)

    Møller, P; Wallin, Håkan; Grunnet, N

    1998-01-01

    , and C.I. pigment orange 5 is a naphthol-azo pigment. The pigments are virtually insoluble in aqueous solutions, and they have not been tested extensively for toxicological effects. C.I. pigment orange 5 increased the levels of DNA damage at 5 microg/ml (P pigment yellow 12 at 20 microg....../ml (P effect of incubation time (20, 40, and 80 min) of the same concentrations of the pigments was tested. The levels of DNA damage were increased up to 80 min. Both pigments produced DNA damage that was in the same range as the food carcinogen 2-amino-3,8-dimethylimidazo[4,5-f......The induction of DNA damage by commonly used printing ink pigments, C.I. pigment orange 5 (C.I. 12075) and C.I. pigment yellow 12 (C.I. 21090), was investigated in freshly isolated rat hepatocytes with the comet assay. C.I. pigment yellow 12 is a 3,3'-dichlorobenzidine-based diarylide pigment...

  4. Quantitative analysis of pigment dispersion taking into account the full agglomerate size distribution

    OpenAIRE

    Kiil, Søren

    2017-01-01

    This work concerns the development of simulation tools for mapping of pigment dispersion. Focus has been on the mechanical breakage of pigment agglomerates. The underlying physical mechanism was assumed to be surface erosion of spherical pigment agglomerates, and the full agglomerate particle size distribution was simulated. Data from previous experimental investigations with organic pigments were used for model validation.When the linear rate of agglomerate surface erosion was taken to be pr...

  5. Structural investigations of LiFePO4 electrodes and in situ studies by Fe X-ray absorption spectroscopy

    International Nuclear Information System (INIS)

    Deb, Aniruddha; Bergmann, Uwe; Cramer, S.P.; Cairns, Elton J.

    2005-01-01

    Fe K-edge X-ray absorption near edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS) have been performed on electrodes containing LiFePO 4 to determine the local atomic and electronic structure and their stability with electrochemical cycling. A versatile electrochemical in situ cell has been constructed for long-term soft and hard X-ray experiments for the structural investigation on battery electrodes during the lithium-insertion/extraction processes. The device is used here for an X-ray absorption spectroscopic study of lithium insertion/extraction in a LiFePO 4 electrode, where the electrode contained about 7.7 mg of LiFePO 4 on a 20 μm thick Al-foil. Fe K-edge X-ray absorption near edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS) have been performed on this electrode to determine the local atomic and electronic structure and their stability with electrochemical cycling. The initial state (LiFePO 4 ) showed iron to be in the Fe 2+ state corresponding to the initial state (0.0 mAh) of the cell, whereas in the delithiated state (FePO 4 ) iron was found to be in the Fe 3+ state corresponding to the final charged state (3 mAh). XANES region of the XAS spectra revealed a high spin configuration for the two states (Fe (II), d 6 and Fe (III), d 5 ). The results confirm that the olivine structure of the LiFePO 4 and FePO 4 is retained by the electrodes in agreement with the XRD observations reported previously. These results confirm that LiFePO 4 cathode material retains good structural short-range order leading to superior cycling capability

  6. Post-mortem MR angiography: quantitative investigation and intravascular retention of perfusates in ex situ porcine hearts.

    Science.gov (United States)

    Webb, Bridgette; Widek, Thomas; Scheicher, Sylvia; Schwark, Thorsten; Stollberger, Rudolf

    2018-03-01

    As the implementation of minimally invasive imaging techniques in both forensic and pathological practice increases, research in this area focuses on addressing recognised diagnostic weaknesses of current approaches. Assessment of sudden cardiac death (SCD) can be considered one such area in which post-mortem imaging still shows diagnostic weaknesses. We hypothesise that magnetic resonance imaging (MRI) with an angiographic adjunct may improve the visualisation and interpretation of cardiac pathologies in a post-mortem setting. To systematically investigate this hypothesis, selected perfusates (paraffin oil, Gadovist®;-doped physiological solution and polyethylene glycol (PEG)) were injected into the left anterior descending (LAD) artery of ex situ porcine hearts to assess the visualisation of perfusates in MRI as well as their intravascular retention over 12 h. Morphological images were acquired and quantitative T 1 maps were generated from inversion recovery data. Visualisation of vascular structure and image quality were assessed using signal-to-noise and contrast-to-noise ratios. Intravascular retention was assessed both visually and statistically using a volume of interest (VOI) approach to analyse significant changes in signal intensity in and around the filled LAD artery, as well as changes in the longitudinal relaxation time (T 1 ) in adjacent myocardium. In addition to presenting possible mechanisms explaining perfusate extravasation given the increased permeability of post-mortem vessels, the potential diagnostic consequences of this phenomenon and the importance of contrast stability and extended intravascular retention are discussed. In light of our findings and these considerations, paraffin oil emerged as the preferred perfusate for use in post-mortem MR angiography.

  7. Studies on the bio production of monascus red pigment

    International Nuclear Information System (INIS)

    Emam, D.A.

    2007-01-01

    there is an increasing interest on natural pigments to replace some currently used synthetic dyes, since the latter have been associated with toxic effects in foods. the red pigment of the fungus Monascus is widely used in all the world as food additives or pharmaceuticals. although pigment production by Monascus spp.in chemically defined media is well documented, very few information is available about the use of agro-industrial wastes. in this regard, the present study has been devoted to investigate the effect of different parameters on red pigment production by the local isolated strain of M. purpureu, in an attempt to maximize the production, and also to develop a potential fermentation process for the production of red pigment using potato processing wastewater (PPW,waters used to wash the potato slices prior to cooking in chips and crisp manufacture) as cheap production medium

  8. An Unexpectedly Complex Architecture for Skin Pigmentation in Africans.

    Science.gov (United States)

    Martin, Alicia R; Lin, Meng; Granka, Julie M; Myrick, Justin W; Liu, Xiaomin; Sockell, Alexandra; Atkinson, Elizabeth G; Werely, Cedric J; Möller, Marlo; Sandhu, Manjinder S; Kingsley, David M; Hoal, Eileen G; Liu, Xiao; Daly, Mark J; Feldman, Marcus W; Gignoux, Christopher R; Bustamante, Carlos D; Henn, Brenna M

    2017-11-30

    Approximately 15 genes have been directly associated with skin pigmentation variation in humans, leading to its characterization as a relatively simple trait. However, by assembling a global survey of quantitative skin pigmentation phenotypes, we demonstrate that pigmentation is more complex than previously assumed, with genetic architecture varying by latitude. We investigate polygenicity in the KhoeSan populations indigenous to southern Africa who have considerably lighter skin than equatorial Africans. We demonstrate that skin pigmentation is highly heritable, but known pigmentation loci explain only a small fraction of the variance. Rather, baseline skin pigmentation is a complex, polygenic trait in the KhoeSan. Despite this, we identify canonical and non-canonical skin pigmentation loci, including near SLC24A5, TYRP1, SMARCA2/VLDLR, and SNX13, using a genome-wide association approach complemented by targeted resequencing. By considering diverse, under-studied African populations, we show how the architecture of skin pigmentation can vary across humans subject to different local evolutionary pressures. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. A method to investigate the electron scattering characteristics of ultrathin metallic films by in situ electrical resistance measurements

    Energy Technology Data Exchange (ETDEWEB)

    Trindade, I. G.; Sousa, J. B. [IFIMUP and IN, Rua do campo Alegre, 687, 4169-007 Porto (Portugal); Department of Physics, FCUP, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Fermento, R. [Instituto de Microelectronica de Madrid, Isaac Newton 8, 28760 Tres Cantos, Madrid (Spain); Leitao, D. [IFIMUP and IN, Rua do campo Alegre, 687, 4169-007 Porto (Portugal)

    2009-07-15

    In this article, a method to measure the electrical resistivity/conductivity of metallic thin films during layer growth on specific underlayers is described. The in situ monitoring of an underlayer electrical resistance, its change upon the incoming of new material atoms/molecules, and the growth of a new layer are presented. The method is easy to implement and allows obtaining in situ experimental curves of electrical resistivity dependence upon film thickness with a subatomic resolution, providing insight in film growth microstructure characteristics, specular/diffuse electron scattering surfaces, and optimum film thicknesses.

  10. Sensitizing pigment in the fly

    International Nuclear Information System (INIS)

    Vogt, K.; Kirschfeld, K.

    1983-01-01

    The sensitizing pigment hypothesis for the high UV sensitivity in fly photoreceptors (R1-6) is further substantiated by measurements of the polarisation sensitivity in the UV. The quantum yield of the energy transfer from sensitizing pigment to rhodopsin was estimated by electrophysiological measurements of the UV sensitivity and the rhabdomeric absorptance (at 490 nm) in individual receptor cells. The transfer efficiency is >=0.75 in receptors with an absorptance in the rhabdomeres of 0.55-0.95. This result suggests that the sensitizing pigment is bound in some way to the rhodopsin. A ratio of two molecules of sensitizing pigment per one rhodopsin is proposed. (orig.)

  11. Does somatostatin have a role in the regulation of cortisol secretion in primary pigmented nodular adrenocortical disease (PPNAD)? A clinical and in vitro investigation

    NARCIS (Netherlands)

    Z. Bram (Zakariae); P. Xekouki (Paraskevi); E. Louiset (Estelle); M. Keil (Mark); D. Avgeropoulos (Dimitrios); C. Giatzakis (Christoforos); M. Nesterova (Maria); N. Sinaii (Ninet); L.J. Hofland (Leo); R. Cherqaoui (Rabia); H. Lefebvre (Hervé); C.A. Stratakis (Constantine)

    2014-01-01

    textabstractContext: Somatostatin (SST) receptors (SSTRs) are expressed in a number of tissues, including the adrenal cortex, but their role in cortisol secretion has not been well characterized. Objectives: The objective of the study was to investigate the expression of SSTRs in the adrenal cortex

  12. In-situ investigation of strain-induced martensitic transformation kinetics in an austenitic stainless steel by inductive measurements

    NARCIS (Netherlands)

    Alonso de Celada Casero, C.; Kooiker, Harm; Groen, Manso; Post, J; San Martin, D

    2017-01-01

    An inductive sensor developed by Philips ATC has been used to study in-situ the austenite (γ) to martensite (α′) phase transformation kinetics during tensile testing in an AISI 301 austenitic stainless steel. A correlation between the sensor output signal and the volume fraction of α′-martensite

  13. Effects of size on the mechanical response of metallic glasses investigated through in situ TEM bending and compression experiments

    NARCIS (Netherlands)

    Chen, C.Q.; Pei, Y.T.; Hosson, J.T.M. De

    Quantitative bending and compression tests on micropillars made of two different amorphous alloys, with tip diameters ranging from 93 to 645 rim, are performed in situ in a transmission electron microscope (TEM). Under microcompression each pillar shows an intermittent plastic flow accommodated by

  14. Investigating suspended sediment dynamics in contrasting agricultural catchments using ex situ turbidity-based suspended sediment monitoring

    Science.gov (United States)

    Sherriff, S. C.; Rowan, J. S.; Melland, A. R.; Jordan, P.; Fenton, O.; hUallachain, D. O.

    2015-08-01

    Soil erosion and suspended sediment (SS) pose risks to chemical and ecological water quality. Agricultural activities may accelerate erosional fluxes from bare, poached or compacted soils, and enhance connectivity through modified channels and artificial drainage networks. Storm-event fluxes dominate SS transport in agricultural catchments; therefore, high temporal-resolution monitoring approaches are required, but can be expensive and technically challenging. Here, the performance of in situ turbidity sensors, conventionally installed submerged at the river bankside, is compared with installations where river water is delivered to sensors ex situ, i.e. within instrument kiosks on the riverbank, at two experimental catchments (Grassland B and Arable B). The in situ and ex situ installations gave comparable results when calibrated against storm-period, depth-integrated SS data, with total loads at Grassland B estimated at 12 800 and 15 400 t, and 22 600 and 24 900 t at Arable B, respectively. The absence of spurious turbidity readings relating to bankside debris around the in situ sensor and its greater security make the ex situ sensor more robust. The ex situ approach was then used to characterise SS dynamics and fluxes in five intensively managed agricultural catchments in Ireland which feature a range of landscape characteristics and land use pressures. Average annual suspended sediment concentration (SSC) was below the Freshwater Fish Directive (78/659/EEC) guideline of 25 mg L-1, and the continuous hourly record demonstrated that exceedance occurred less than 12 % of the observation year. Soil drainage class and proportion of arable land were key controls determining flux rates, but all catchments reported a high degree of inter-annual variability associated with variable precipitation patterns compared to the long-term average. Poorly drained soils had greater sensitivity to runoff and soil erosion, particularly in catchments with periods of bare soils. Well

  15. Pigmented villo nodular synovitis

    Directory of Open Access Journals (Sweden)

    Radha S

    2006-01-01

    Full Text Available Background: Pigmented villonodular synovitis is a rare disorder affecting joints. Methods : We reviewed 19 cases of pigmented villonodular synovitis out of 481 arthroscopic synovial biopsies over a period of ten years. A common presenting symptom was locking. Both diffuse and localized forms were diagnosed. Duration of symptoms varied from 5 months to3 years. We report our experience of patients treated by arthroscopic excision for localized villonodular synovitis and arthroscopic synovectomy for diffuse villonodular synovitis followed by intraarticular Yttrium. Results : In diffuse villonodular synovitis arthroscopic total synovectomy was done a using special angular and straight motorized shaver through different portals to reach all corners of the joint. Localized variety was treated by excising the pedicle attached to the synovium. In our series none of the patients with localized villonodular synovitis showed recurrence till date. Three cases of diffuse variety presented with effusion and swelling three to six months after treatment and were managed by arthoscopic synovial shaving. Two cases who showed recurrence after one year were subjected to intraarticular 90Y isotope injection. Conclusion : Arthroscopic synovectomy helps in reducing morbidity. Radiation and intraarticular Injection of 90 Y are alternative modes of treatment.

  16. In situ investigation of titanium nitride surface dynamics: The role of surface and bulk mass transport processes

    Science.gov (United States)

    Bareno, Javier

    NaCl-structure TiN and related transition-metal (TM) nitrides are widely used as hard wear-resistant coatings on cutting tools, diffusion-barriers in microelectronic devices, corrosion-resistant layers on mechanical components, and abrasion-resistant thin films on optics and architectural glass. Since the elastic and physical properties of TiN are highly anisotropic, controlling the microstructural and surface morphological evolution of polycrystalline TM nitride films is important for all of the above applications. In this thesis, I used in-situ high-temperature low-energy electron microscopy (LEEM) to gain insight into film growth and microstructure development dynamics by studying mass-transport processes occurring during annealing of three dimensional (3D) structures on TiN surfaces. Additionally, in order to extend the current understanding of nanostructure development in binary nitride films to more complex ternary TM-nitride-based nanocomposites, I employed in-situ scanning tunneling microscopy (STM) and low-energy electron diffraction (LEED), as well as ab-initio modeling, to investigate the atomic structure of the SiNx/TiN heterointerfaces which control the properties of SiNx-TiN nanocomposites. The LEEM studies of mass transport on TiN(111) focus on two specific surface morphologies which are observed to be present during growth of TiN single-crystals. (1) I investigated the temperature-dependent coarsening/decay kinetics of three-dimensional TiN island mounds on large (>1000 A) atomically-flat terraces; showing that TiN(111) steps are highly permeable and exhibit strong repulsive temperature-dependent step-step interactions that vary from 0.03 eV-A at 1559 K to 0.76 eV-A at 1651 K. (2) I studied the nucleation and growth of spiral steps originating at surface-terminated screw dislocations; I developed a model of spiral growth relating the emission rate of point defects from the bulk to the temperature-dependent spiral rotation frequency o(T); and I

  17. Stem Cell Derived Retinal Pigment Epithelium: The Role of Pigmentation as Maturation Marker and Gene Expression Profile Comparison with Human Endogenous Retinal Pigment Epithelium.

    Science.gov (United States)

    Bennis, A; Jacobs, J G; Catsburg, L A E; Ten Brink, J B; Koster, C; Schlingemann, R O; van Meurs, J; Gorgels, T G M F; Moerland, P D; Heine, V M; Bergen, A A

    2017-10-01

    In age-related macular degeneration (AMD) the retinal pigment epithelium (RPE) deteriorates, leading to photoreceptor decay and severe vision loss. New therapeutic strategies aim at RPE replacement by transplantation of pluripotent stem cell (PSC)-derived RPE. Several protocols to generate RPE have been developed where appearance of pigmentation is commonly used as indicator of RPE differentiation and maturation. It is, however, unclear how different pigmentation stages reflect developmental stages and functionality of PSC-derived RPE cells. We generated human embryonic stem cell-derived RPE (hESC-RPE) cells and investigated their gene expression profiles at early pigmentation (EP) and late pigmentation (LP) stages. In addition, we compared the hESC-RPE samples with human endogenous RPE. We used a common reference design microarray (44 K). Our analysis showed that maturing hESC-RPE, upon acquiring pigmentation, expresses markers specific for human RPE. Interestingly, our analysis revealed that EP and LP hESC-RPE do not differ much in gene expression. Our data further showed that pigmented hESC-RPE has a significant lower expression than human endogenous RPE in the visual cycle and oxidative stress pathways. In contrast, we observed a significantly higher expression of pathways related to the process adhesion-to-polarity model that is typical of developing epithelial cells. We conclude that, in vitro, the first appearance of pigmentation hallmarks differentiated RPE. However, further increase in pigmentation does not result in much significant gene expression changes and does not add important RPE functionalities. Consequently, our results suggest that the time span for obtaining differentiated hESC-RPE cells, that are suitable for transplantation, may be greatly reduced.

  18. Gold supported on tungstated zirconia : synthesis, characterization and in situ FT-IR investigation of NO(formula) + CH(formula) surface reactions

    OpenAIRE

    Mametsheripov, Serdar

    2012-01-01

    Ankara : The Department of Chemistry and the Institute of Engineering and Sciences of Bilkent University, 2012. Thesis (Master's) -- Bilkent University, 2012. Includes bibliographical references leaves 62-72. The potential of gold supported on tungstated zirconia as a catalyst for selective catalytic reduction of NOx with propene (C3H6-SCR) was investigated by in situ FT-IR spectroscopy. Samples of tungstated zirconia were prepared by both impregnation and coprecipitation m...

  19. Nonphotosynthetic Pigments as Potential Biosignatures

    Science.gov (United States)

    Cockell, Charles S.; Meadows, Victoria S.

    2015-01-01

    Abstract Previous work on possible surface reflectance biosignatures for Earth-like planets has typically focused on analogues to spectral features produced by photosynthetic organisms on Earth, such as the vegetation red edge. Although oxygenic photosynthesis, facilitated by pigments evolved to capture photons, is the dominant metabolism on our planet, pigmentation has evolved for multiple purposes to adapt organisms to their environment. We present an interdisciplinary study of the diversity and detectability of nonphotosynthetic pigments as biosignatures, which includes a description of environments that host nonphotosynthetic biologically pigmented surfaces, and a lab-based experimental analysis of the spectral and broadband color diversity of pigmented organisms on Earth. We test the utility of broadband color to distinguish between Earth-like planets with significant coverage of nonphotosynthetic pigments and those with photosynthetic or nonbiological surfaces, using both 1-D and 3-D spectral models. We demonstrate that, given sufficient surface coverage, nonphotosynthetic pigments could significantly impact the disk-averaged spectrum of a planet. However, we find that due to the possible diversity of organisms and environments, and the confounding effects of the atmosphere and clouds, determination of substantial coverage by biologically produced pigments would be difficult with broadband colors alone and would likely require spectrally resolved data. Key Words: Biosignatures—Exoplanets—Halophiles—Pigmentation—Reflectance spectroscopy—Spectral models. Astrobiology 15, 341–361. PMID:25941875

  20. In-Situ Investigation of Strain-Induced Martensitic Transformation Kinetics in an Austenitic Stainless Steel by Inductive Measurements

    Directory of Open Access Journals (Sweden)

    Carola Celada-Casero

    2017-07-01

    Full Text Available An inductive sensor developed by Philips ATC has been used to study in-situ the austenite (γ to martensite (α′ phase transformation kinetics during tensile testing in an AISI 301 austenitic stainless steel. A correlation between the sensor output signal and the volume fraction of α′-martensite has been found by comparing the results to the ex-situ characterization by magnetization measurements, light optical microscopy, and X-ray diffraction. The sensor has allowed for the observation of the stepwise transformation behavior, a not-well-understood phenomena that takes place in large regions of the bulk material and that so far had only been observed by synchrotron X-ray diffraction.

  1. A modular reactor design for in situ synchrotron x-ray investigation of atomic layer deposition processes

    Science.gov (United States)

    Klug, Jeffrey A.; Weimer, Matthew S.; Emery, Jonathan D.; Yanguas-Gil, Angel; Seifert, Sönke; Schlepütz, Christian M.; Martinson, Alex B. F.; Elam, Jeffrey W.; Hock, Adam S.; Proslier, Thomas

    2015-11-01

    Synchrotron characterization techniques provide some of the most powerful tools for the study of film structure and chemistry. The brilliance and tunability of the Advanced Photon Source allow access to scattering and spectroscopic techniques unavailable with in-house laboratory setups and provide the opportunity to probe various atomic layer deposition (ALD) processes in situ starting at the very first deposition cycle. Here, we present the design and implementation of a portable ALD instrument which possesses a modular reactor scheme that enables simple experimental switchover between various beamlines and characterization techniques. As first examples, we present in situ results for (1) X-ray surface scattering and reflectivity measurements of epitaxial ZnO ALD on sapphire, (2) grazing-incidence small angle scattering of MnO nucleation on silicon, and (3) grazing-incidence X-ray absorption spectroscopy of nucleation-regime Er2O3 ALD on amorphous ALD alumina and single crystalline sapphire.

  2. New directions in phthalocyanine pigments

    Science.gov (United States)

    Trinh, Diep VO

    1994-01-01

    Phthalocyanines have been used as a pigment in coatings and related applications for many years. These pigments are some of the most stable organic pigments known. The phthalo blue and green pigments have been known to be ultraviolet (UV) stable and thermally stable to over 400 C. These phthalocyanines are both a semiconductor and photoconductor, exhibiting catalytic activity and photostabilization capability of polymers. Many metal free and metallic phthalocyanine derivatives have been prepared. Development of the new classes of phthalocyanine pigment could be used as coating on NASA spacecraft material such as glass to decrease the optical degradation from UV light, the outside of the space station modules for UV protection, and coating on solar cells to increase lifetime and efficiency.

  3. Bridging the "pressure gap" towards high pressures - Elastic neutron scattering for in-situ investigation of catalysts under industrial conditions

    OpenAIRE

    Kandemir, T.; Wallacher, D.; Tovar, M.; Hansen, T.; Kasatkin, I.; Schlögl, R.; Behrens, M.

    2011-01-01

    Catalyst characterization is usually performed in the pressure range from UHV to ambient depending on the methods used. Linear extrapolation of the catalytic properties over these several orders of magnitude in pressure is often not possible (“pressure gap”), which makes in-situ characterization necessary. Typically, only little information is available about structural dynamics of catalysts at pressures above atmospheric pressure, i.e. in the range, which is important for many industrial pro...

  4. Extensive physiologic melanin pigmentation on the tongue: An unusual clinical presentation

    Directory of Open Access Journals (Sweden)

    Sunira Chandra

    2010-01-01

    Full Text Available Pigmented lesions are commonly found in the oral cavity. Pigmentation has a multifactorial etiology. Most of the oral pigmentations are physiologic but sometimes it can be a precursor of severe diseases. Evaluation of a patient presented with a pigmented lesion should include a full medical and dental history, extraoral and intraoral examinations and even in some cases biopsy and laboratory investigations are required. In this article, we report a case of extensive physiologic pigmentation on the tongue in a 32-year-old female patient, posing a diagnostic challenge.

  5. Extensive physiologic melanin pigmentation on the tongue: An unusual clinical presentation

    Science.gov (United States)

    Chandra, Sunira; Keluskar, Vaishali; Bagewadi, Anjana; Sah, Kunal

    2010-01-01

    Pigmented lesions are commonly found in the oral cavity. Pigmentation has a multifactorial etiology. Most of the oral pigmentations are physiologic but sometimes it can be a precursor of severe diseases. Evaluation of a patient presented with a pigmented lesion should include a full medical and dental history, extraoral and intraoral examinations and even in some cases biopsy and laboratory investigations are required. In this article, we report a case of extensive physiologic pigmentation on the tongue in a 32-year-old female patient, posing a diagnostic challenge. PMID:22114419

  6. Iris phenotypes and pigment dispersion caused by genes influencing pigmentation.

    Science.gov (United States)

    Anderson, Michael G; Hawes, Norman L; Trantow, Colleen M; Chang, Bo; John, Simon W M

    2008-10-01

    Spontaneous mutations altering mouse coat colors have been a classic resource for discovery of numerous molecular pathways. Although often overlooked, the mouse iris is also densely pigmented and easily observed, thus representing a similarly powerful opportunity for studying pigment cell biology. Here, we present an analysis of iris phenotypes among 16 mouse strains with mutations influencing melanosomes. Many of these strains exhibit biologically and medically relevant phenotypes, including pigment dispersion, a common feature of several human ocular diseases. Pigment dispersion was identified in several strains with mutant alleles known to influence melanosomes, including beige, light, and vitiligo. Pigment dispersion was also detected in the recently arising spontaneous coat color variant, nm2798. We have identified the nm2798 mutation as a missense mutation in the Dct gene, an identical re-occurrence of the slaty light mutation. These results suggest that dysregulated events of melanosomes can be potent contributors to the pigment dispersion phenotype. Combined, these findings illustrate the utility of studying iris phenotypes as a means of discovering new pathways, and re-linking old ones, to processes of pigmented cells in health and disease.

  7. Natural pigments and sacred art

    Science.gov (United States)

    Kelekian, Lena, ,, Lady

    2010-05-01

    Since the dawn of mankind, cavemen has expressed himself through art. The earliest known cave paintings date to some 32,000 years ago and used 4 colours derived from the earth. These pigments were iron oxides and known as ochres, blacks and whites. All pigments known by the Egyptians, the Greeks, the Romans and Renaissance man were natural and it was not until the 18th century that synthetic pigments were made and widely used. Until that time all art, be it sacred or secular used only natural pigments, of which the preparation of many have been lost or rarely used because of their tedious preparation. As a geologist, a mineralogist and an artist specializing in iconography, I have been able to rediscover 89 natural pigments extracted from minerals. I use these pigments to paint my icons in the traditional Byzantine manner and also to restore old icons, bringing back their glamour and conserving them for years to come. The use of the natural pigments in its proper way also helps to preserve the traditional skills of the iconographer. In the ancient past, pigments were extremely precious. Many took an exceedingly long journey to reach the artists, and came from remote countries. Research into these pigments is the work of history, geography and anthropology. It is an interesting journey in itself to discover that the blue aquamarines came from Afghanistan, the reds from Spain, the greens Africa, and so on. In this contribution I will be describing the origins, preparation and use of some natural pigments, together with their history and provenance. Additionally, I will show how the natural pigments are used in the creation of an icon. Being a geologist iconographer, for me, is a sacrement that transforms that which is earthly, material and natural into a thing of beauty that is sacred. As bread and wine in the Eucharist, water during baptism and oil in Holy Union transmit sanctification to the beholder, natural pigments do the same when one considers an icon. The

  8. An uncovered XIII century icon: Particular use of organic pigments and gilding techniques highlighted by analytical methods

    Science.gov (United States)

    Daveri, Alessia; Doherty, Brenda; Moretti, Patrizia; Grazia, Chiara; Romani, Aldo; Fiorin, Enrico; Brunetti, Brunetto Giovanni; Vagnini, Manuela

    2015-01-01

    The restoration of a panel painting depicting a Madonna and Child listed as an unknown Tuscan artist of the nineteenth century, permitted the hidden original version, a XIII century Medieval icon to be uncovered. It is discovery provided the opportunity for an extensive in situ campaign of non-invasive analytical investigations by portable imaging and spectroscopic techniques (infrared, X-ray fluorescence and diffraction, UV-Vis absorption and emission), followed by aimed micro-destructive investigations (Raman and SEM-EDS). This approach permitted characterization of the original ground and paint layers by complementary techniques. Furthermore, this protocol allowed supplementary particularities of great interest to be highlighted. Namely, numerous original gilding techniques have been accentuated in diverse areas and include the use of surrogate gold (disulphur tin), orpiment as a further false gold and an area with an original silver rich layer. Moreover, pigments including azurite mixed with indigo have been non-invasively identified. Micro-invasive analyses also allowed the diagnosis of organic colorants, namely, an animal anthraquinone lake, kermes and an unusual vegetal chalcone pigment, possibly safflower. The identification of the latter is extremely rare as a painting pigment and has been identified using an innovative adaption to surface enhanced Raman techniques on a cross-section. The resulting data contributes new hypotheses to the historic and artistic knowledge of materials and techniques utilized in XIII century icon paintings and ultimately provides scientific technical support of the recent restoration.

  9. Chemical stability of carbon-based inorganic materials for in situ x-ray investigations of ammonothermal crystal growth of nitrides

    Science.gov (United States)

    Schimmel, Saskia; Künecke, Ulrike; Meisel, Magnus; Hertweck, Benjamin; Steigerwald, Thomas G.; Nebel, Christoph; Alt, Nicolas S. A.; Schlücker, Eberhard; Wellmann, Peter

    2016-12-01

    The chemical stability of diamond, silicon carbide, vitreous carbon, and boron carbide in supercritical ammonia containing different mineralizers was investigated. The materials were found to show good corrosion resistance in the presence of selective or all tested mineralizers. Diamond was found to be virtually inert in both ammonoacidic and ammonobasic reaction media. Silicon carbide showed good chemical stability in varying ammonothermal reaction media. The chemical stability of vitreous carbon was found to depend on its manufacturing temperature. Corrosion of boron carbide strongly depends on the mineralizer used as well as on applied mechanical stress. Based on their chemical stability and mechanical properties, the applicability of the materials in the respective ammonothermal reaction media as construction materials is evaluated. Additionally, the applicability of the materials as a window material for both high energy in situ x-ray imaging and low energy in situ x-ray diffraction is discussed.

  10. Synthesis of chromium containing pigments from chromium galvanic sludges

    International Nuclear Information System (INIS)

    Andreola, F.; Barbieri, L.; Bondioli, F.; Cannio, M.; Ferrari, A.M.; Lancellotti, I.

    2008-01-01

    In this work the screening results of the scientific activity conducted on laboratory scale to valorise chromium(III) contained in the galvanic sludge as chromium precursor for ceramic pigments are reported. The valorisation of this waste as a secondary raw material (SRM) is obtained by achievement of thermal and chemical stable crystal structures able to color ceramic material. Two different pigments pink CaCr 0.04 Sn 0.97 SiO 5 and green Ca 3 Cr 2 (SiO 4 ) 3 were synthesized by solid-state reactions using dried Cr sludge as chromium oxide precursor. The obtained pigments were characterized by X-ray diffraction and SEM analysis. Furthermore the color developed in a suitable ceramic glaze was investigated in comparison with the color developed by the pigments prepared from pure Cr 2 O 3 . The characterization carried out corroborates the thermal and chemical stability of the synthesized pigments and, especially for the Cr-Sn pink pigment, the powders develop an intense color that is very similar to the color developed by the pigments obtained starting from pure Cr 2 O 3

  11. Optimizing Angkak Pigments and Lovastatin Production By Monascus purpureus

    Directory of Open Access Journals (Sweden)

    HASIM DANURI

    2008-06-01

    Full Text Available Angkak pigments and lovastatin had been reported very useful as natural coloring agents, as an agent to increase thrombocyte level in Dengue hemorrhagic fever, and also as a compound that was able to control blood cholesterol level. Three strains of fungus Monascus purpureus AKI, AKII, and 915 were selected to produce angkak pigments and lovastatin in potato dextrose agar (PDA medium. The best fungus strain, which is AKII, was then applied in three kinds of rice media (white rice IR-42, red rice BP-1804-IF-9, and a combination of 1:1 (w/w white IR-42 and red rice BP-1804-IF-9 for solid fermentation. The best medium and fermentation times were determined for the production of angkak pigments and lovastatin separately. Results showed that strains, media, and duration of fermentations gave significant effect on the amount of pigment produced. Strain AKII produced highest concentration of angkak pigments. The combination of rice (White IR-42 and red rice BP-1804-IF-9 produced the highest pigment than the individual white and red rie it self. The optimum duration of fermentation was 16 days for strains AKI and AKII, but only 15 days for strain 915. Therefore the strain AKII with media combination of rice and a fermentation time of 16 days were used to investigate the additional effect of various minerals. Addition of the mineral individually gave significant increased on angkak pigment production by AKII, where as the addition of minerals mixture in the forth tube did not.

  12. SEM in situ laboratory investigations on damage growth in GFRP composite under three-point bending tests

    DEFF Research Database (Denmark)

    Zhou, Hong Wei; Mishnaevsky, Leon; Brøndsted, Povl

    2010-01-01

    Glass fiber-reinforced polymer (GFRP) composites are widely used in low-weight constructions. SEM (scanning electron microscopy) in situ experiments of damage growth in GFRP composite under three-point bending loads are carried out. By summarizing the experimental results of three groups of samples...... with different orientation angles of fibers, the dependence of mechanical parameters on the orientation angles of fibers are analyzed. The regression analysis show that the peak strengths, the elastic strengths and the elastic modulus of the composites decease with the orientation angles of fibers almost...

  13. Adsorption of human insulin on single-crystal gold surfaces investigated by in situ scanning tunnelling microscopy and electrochemistry

    DEFF Research Database (Denmark)

    Welinder, Anna Christina; Zhang, Jingdong; Steensgaard, D.B.

    2010-01-01

    We have explored the adsorption of zinc-free human insulin on the three low-index single-crystalline Au(111)-, Au(100)- and Au(110)-surfaces in aqueous buffer (KH2PO4, pH 5) by a combination of electrochemical scanning tunnelling microscopy (in situ STM) at single-molecule resolution and linear...... sweep, LSV, cyclic, CV, and square wave (SQWV) voltammetry. Multifarious electrochemical patterns were observed. Most attention was given to reductive desorption caused by insulin binding to the Au-surfaces via up to three disulfide groups per insulin monomer, presumably converted to single Au-S links...

  14. Malayaite ceramic pigments prepared with galvanic sludge as colouring agent

    OpenAIRE

    Costa, Gracia; Ribeiro, Manuel J.; Labrincha, Joao A.; Dondi, Michele; Matteucci, Francesco; Cruciani, Giuseppe

    2008-01-01

    The synthesis and characterisation of chrome?-tin red malayaite Ca(Cr,Sn)SiO5 pigments are reported. The novel approach of using a galvanizing sludge from the Cr/Ni plating process as colouring agent is investigated. The ceramic pigments were prepared using common solid state reaction process, with optimisation of milling and firing conditions. Characterisation was done by x-?ray powder diffraction, diffuse reflectance spectroscopy, and application in standard ceramic glazes. The ceramic pigm...

  15. Ozone Sensitivity and Catalase Activity in Pigmented and Non-Pigmented Strains of Serratia Marcescens

    Science.gov (United States)

    de Ondarza, José

    2017-01-01

    Background: Ozone exposure rapidly leads to bacterial death, making ozone an effective disinfectant in food industry and health care arena. However, microbial defenses may moderate this effect and play a role in the effective use of oxidizing agents for disinfection. Serratia marcescens is an opportunistic pathogen, expressing genes differentially during infection of a human host. A better understanding of regulatory systems that control expression of Serratia’s virulence genes and defenses is therefore valuable. Objective: Here, we investigated the role of pigmentation and catalase in Serratia marcescens on survival to ozone exposure. Method: Pigmented and non-pigmented strains of Serratia marcescens were cultured to exponential or stationary phase and exposed to 5 ppm of gaseous ozone for 2.5 – 10 minutes. Survival was calculated via plate counts. Catalase activity was measured photometrically and tolerance to hydrogen peroxide was assayed by disk-diffusion. Results: Exposure of S. marcescens to 5 ppm gaseous ozone kills > 90% of cells within 10 minutes in a time and concentration-dependent manner. Although pigmented Serratia (grown at 28°C) survived ozonation better than unpigmented Serratia (grown at 35°C), non-pigmented mutant strains of Serratia had similar ozone survival rates, catalase activity and H2O2 tolerance as wild type strains. Rather, ozone survival and catalase activity were elevated in 6 hour cultures compared to 48 hour cultures. Conclusion: Our studies did not bear out a role for prodigiosin in ozone survival. Rather, induction of oxidative stress responses during exponential growth increased both catalase activity and ozone survival in both pigmented and unpigmented S. marcescens. PMID:28567147

  16. Ozone Sensitivity and Catalase Activity in Pigmented and Non-Pigmented Strains of Serratia Marcescens.

    Science.gov (United States)

    de Ondarza, José

    2017-01-01

    Ozone exposure rapidly leads to bacterial death, making ozone an effective disinfectant in food industry and health care arena. However, microbial defenses may moderate this effect and play a role in the effective use of oxidizing agents for disinfection. Serratia marcescens is an opportunistic pathogen, expressing genes differentially during infection of a human host. A better understanding of regulatory systems that control expression of Serratia 's virulence genes and defenses is therefore valuable. Here, we investigated the role of pigmentation and catalase in Serratia marcescens on survival to ozone exposure. Pigmented and non-pigmented strains of Serratia marcescens were cultured to exponential or stationary phase and exposed to 5 ppm of gaseous ozone for 2.5 - 10 minutes. Survival was calculated via plate counts. Catalase activity was measured photometrically and tolerance to hydrogen peroxide was assayed by disk-diffusion. Exposure of S. marcescens to 5 ppm gaseous ozone kills > 90% of cells within 10 minutes in a time and concentration-dependent manner. Although pigmented Serratia (grown at 28°C) survived ozonation better than unpigmented Serratia (grown at 35°C), non-pigmented mutant strains of Serratia had similar ozone survival rates, catalase activity and H 2 O 2 tolerance as wild type strains. Rather, ozone survival and catalase activity were elevated in 6 hour cultures compared to 48 hour cultures. Our studies did not bear out a role for prodigiosin in ozone survival. Rather, induction of oxidative stress responses during exponential growth increased both catalase activity and ozone survival in both pigmented and unpigmented S. marcescens .

  17. Gingival Pigmentation Affected by Smoking among Different Age Groups: A Quantitative Analysis of Gingival Pigmentation Using Clinical Oral Photographs.

    Science.gov (United States)

    Kato, Tomotaka; Mizutani, Shinsuke; Takiuchi, Hiroya; Sugiyama, Seiichi; Hanioka, Takashi; Naito, Toru

    2017-08-04

    The presence of any age-related differences in gingival pigmentation associated with smoking, particularly in a young population, remains to be fully investigated. The purpose of this study was to determine the age-related differences in smoking gingival pigmentation. Gingival pigmentation was analyzed using the gingival melanosis record (GMR) and Hedin's classification with frontal oral photographs taken at 16 dental offices in Japan. Participants were categorized into 10-year age groups, and their baseline photographs were compared. In addition, to evaluate the effect of smoking cessation on gingival pigmentation, subjects were divided into a former smoker group (stopped smoking) and current smoker group. A total of 259 patients 19 to 79 years of age were analyzed. People in their 30s showed the most widespread gingival pigmentation. In addition, subjects in their 20s showed a weak effect of smoking cessation on gingival pigmentation. These findings suggested that the gingival pigmentation induced by smoking was more remarkable in young people than in middle-aged people. This information may be useful for anti-smoking education, especially among young populations with a high affinity for smoking.

  18. The penetration depth and lateral distribution of pigment related to the pigment grain size and the calendering of paper

    International Nuclear Information System (INIS)

    Buelow, K.; Kristiansson, P.; Schueler, B.; Tullander, E.; Oestling, S.; Elfman, M.; Malmqvist, K.; Pallon, J.; Shariff, A.

    2002-01-01

    The interaction of ink and newspaper has been investigated and the specific question of penetration of ink into the paper has been addressed with a nuclear microprobe using particle induced X-ray emission. The penetration depth of the newsprint is a critical factor in terms of increasing the quality of newsprint and minimising the amount of ink used. The objective of the experiment was to relate the penetration depth of pigment with the calendering of the paper. The dependence of the penetration depth on the pigment grain size was also studied. To study the penetration depth of pigment in paper, cyan ink with Cu as a tracer of the coloured pigment was used. For the study of the penetration depth dependence of pigment size, specially grounded Japanese ink with well-defined pigment grain size was used. This was compared to Swedish ink with pigment grains with normal size-distribution. The results show that the calendering of the paper considerably affects the penetration depth of ink

  19. In situ investigations on the formation and decomposition of KSiH3 and CsSiH3

    International Nuclear Information System (INIS)

    Auer, Henry; Kohlmann, Holger

    2017-01-01

    The system KSi-KSiH 3 stores 4.3 wt % of hydrogen and shows a very good reversibility at mild conditions of 0.1 MPa hydrogen pressure and 414 K.[] We followed the reaction pathways of the hydrogenation reactions of KSi and its higher homologue CsSi by in situ methods in order to check for possible intermediate hydrides. In situ diffraction at temperatures up to 500 K and gas pressures up to 5.0 MPa hydrogen gas for X-ray and deuterium gas for neutron reveal that both KSi and CsSi react in one step to the hydrides KSiH 3 and CsSiH 3 and the respective deuterides. Neither do the Zintl phases dissolve hydrogen (deuterium), nor do the hydrides (deuterides) show any signs for non-stoichiometry, i.e. all phases involved in the formation are line phases. Heating to temperatures above 500 K shows that at 5.0 MPa hydrogen pressure only the reaction 2CsSi + 3H 2 = 2CsSiH 3 is reversible. Under these conditions, KSiH 3 decomposes to a clathrate and potassium hydride according to 46KSiH 3 = K 8 Si 46 + 38KH + 50H 2 . (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Investigation of Wireless Sensor Deployment Schemes for In-Situ Measurement of Water Ice near Lunar South Pole

    Directory of Open Access Journals (Sweden)

    Jayesh P. PABARI

    2009-12-01

    Full Text Available It has been known for many years that the Moon has no atmosphere and hence no stable surface water. Cold traps on the Moon near lunar South Pole are understood to have water ice present in them due to striking of comets and meteorites with the Moon. Observations from very recent lunar missions indicate presence of water on the Moon. However, all such methods are based on remote techniques and no in-situ measurements have been done so far. In order to carry out in situ measurement of water ice and also to study properties of Regolith near lunar South Pole, it is planned to deploy wireless sensor network on lunar surface. Deployment of sensors on a planet or outer body like the Moon is really a challenging task and needs theoretical understanding before implementing through any space mission, as it involves huge amount of investment. In this article, we have attempted to understand theoretical aspects involved in deployment of sensors on the Moon. Minimum number of sensors needed in each topology to cover a given sensing region has been found assuring wireless connectivity. Derived equations governing trajectory of deployment topologies have been executed using code in MATLAB and deployment costs for all three schemes are compared.

  1. In-situ investigation of the low-pressure MOCVD growth of III-V compounds using reflectance anisotropy measurements

    Science.gov (United States)

    Drevillon, Bernard; Razeghi, Manijeh

    1991-03-01

    Recent in situ applications of reflectance anisotropy (RA) to the study of the growth of 111-V materials by low pressure MOCVD are reviewed. These results illustrate the extreme sensitivity of the RA technique. During heterojunction growth the first 1-2 seconds are dominated by the change of group V species. Over the time scale of several minutes the signal exhibits damped oscillations correlated to the growth rate. An optical model is proposed to account for this behaviour. A difference in the optical anisotropy between growing and non-growing AsH3 stabilized InAs surface is observed. Large reflectance anisotropies during the growth of lattice-mismatched semiconductors are also presented. It is shown that these anisotropies are related to 3-dimensional growth. The beginning of the lattice-mismatched growth is quantitatively described by an optical model based on effective medium theories. More generally RA technique appears a very promising new method for in situ monitoring of epitaxial processes.

  2. New Directions in Phthalocyanine Pigments

    Science.gov (United States)

    Vandemark, Michael R.

    1992-01-01

    The objectives were the following: (1) investigation of the synthesis of new phthalocyanines; (2) characterization of the new phthalocyanines synthesized; (3) investigate the properties of the newly synthesized phthalocyanines with emphasis on UV protection of plastics and coatings; and (4) utilize quantum mechanics to evaluate the structural relationships with possible properties and synthetic approaches. The proposed research targeted the synthesis of phthalocyanines containing an aromatic bridge between two phthalocyanine rings. The goal was to synthesize pigments which would protect plastics when exposed to the photodegradation effects of the sun in space. The stability and extended conjugation of the phthalocyanines offer a unique opportunity for energy absorption and numerous radiative and non-radiative energy loss mechanisms. Although the original targeted phthalocyanines were changed early in the project, several new and unique phthalocyanine compounds were prepared. The basic goals of this work were met and some unique and unexpected outcomes of the work were the result of the integral use of quantum mechanics and molecular modeling with the synthetic effort.

  3. In Situ Investigation of the Evolution of Lattice Strain and Stresses in Austenite and Martensite During Quenching and Tempering of Steel

    Science.gov (United States)

    Villa, M.; Niessen, F.; Somers, M. A. J.

    2018-01-01

    Energy dispersive synchrotron X-ray diffraction was applied to investigate in situ the evolution of lattice strains and stresses in austenite and martensite during quenching and tempering of a soft martensitic stainless steel. In one experiment, lattice strains in austenite and martensite were measured in situ in the direction perpendicular to the sample surface during an austenitization, quenching, and tempering cycle. In a second experiment, the sin2 ψ method was applied in situ during the austenite-to-martensite transformation to distinguish between macro- and phase-specific micro-stresses and to follow the evolution of these stresses during transformation. Martensite formation evokes compressive stress in austenite that is balanced by tensile stress in martensite. Tempering to 748 K (475 °C) leads to partial relaxation of these stresses. Additionally, data reveal that (elastic) lattice strain in austenite is not hydrostatic but hkl dependent, which is ascribed to plastic deformation of this phase during martensite formation and is considered responsible for anomalous behavior of the 200 γ reflection.

  4. Switching operation and degradation of resistive random access memory composed of tungsten oxide and copper investigated using in-situ TEM.

    Science.gov (United States)

    Arita, Masashi; Takahashi, Akihito; Ohno, Yuuki; Nakane, Akitoshi; Tsurumaki-Fukuchi, Atsushi; Takahashi, Yasuo

    2015-11-27

    In-situ transmission electron microscopy (in-situ TEM) was performed to investigate the switching operation of a resistive random access memory (ReRAM) made of copper, tungsten oxide and titanium nitride (Cu/WOx/TiN). In the first Set (Forming) operation to initialize the device, precipitation appeared inside the WOx layer. It was presumed that a Cu conducting filament was formed, lowering the resistance (on-state). The Reset operation induced a higher resistance (the off-state). No change in the microstructure was identified in the TEM images. Only when an additional Reset current was applied after switching to the off-state could erasure of the filament be seen (over-Reset). Therefore, it was concluded that structural change relating to the resistance switch was localized in a very small area around the filament. With repeated switching operations and increasing operational current, the WOx/electrode interfaces became indistinct. At the same time, the resistance of the off-state gradually decreased. This is thought to be caused by Cu condensation at the interfaces because of leakage current through the area other than through the filament. This will lead to device degradation through mechanisms such as endurance failure. This is the first accelerated aging test of ReRAM achieved using in-situ TEM.

  5. Change of Monascus pigment metabolism and secretion in different extractive fermentation process.

    Science.gov (United States)

    Chen, Gong; Tang, Rui; Tian, Xiaofei; Qin, Peng; Wu, Zhenqiang

    2017-06-01

    Monascus pigments that were generally produced intracellularly from Monascus spp. are important natural colorants in food industry. In this study, change of pigment metabolism and secretion was investigated through fed-batch extractive fermentation and continuous extractive fermentation. The biomass, secreting rate of pigment and total pigment yield closely correlated with the activated time of extractive fermentation as well as the composition of feeding nutrients. Metal ions played a key role in both the cell growth and pigment metabolism. Nitrogen source was necessary for a high productivity of biomass but not for high pigment yield. Furthermore, fermentation period for the fed-batch extractive fermentation could be reduced by 18.75% with a nitrogen source free feeding medium. Through a 30-day continuous extractive fermentation, the average daily productivity for total pigments reached 74.9 AU day -1 with an increase by 32.6 and 296.3% compared to that in a 6-day conventional batch fermentation and a 16-day fed-batch extractive fermentation, respectively. At the meantime, proportions of extracellular pigments increased gradually from 2.7 to 71.3%, and yellow pigments gradually became dominated in both intracellular and extracellular pigments in the end of continuous extractive fermentation. This findings showed that either fed-batch or continuous extractive fermentation acted as a promising method in the efficient production of Monascus pigments.

  6. Controlling composition and color characteristics of Monascus pigments by pH and nitrogen sources in submerged fermentation.

    Science.gov (United States)

    Shi, Kan; Song, Da; Chen, Gong; Pistolozzi, Marco; Wu, Zhenqiang; Quan, Lei

    2015-08-01

    Submerged fermentations of Monascus anka were performed with different nitrogen sources at different pH in 3 L bioreactors. The results revealed that the Monascus pigments dominated by different color components (yellow pigments, orange pigments or red pigments) could be selectively produced through pH control and nitrogen source selection. A large amount of intracellular pigments dominated by orange pigments and a small amount of water-soluble extracellular yellow pigments were produced at low pH (pH 2.5 and 4.0), independently of the nitrogen source employed. At higher pH (pH 6.5), the role of the nitrogen source became more significant. In particular, when ammonium sulfate was used as nitrogen source, the intracellular pigments were dominated by red pigments with a small amount of yellow pigments. Conversely, when peptone was used, intracellular pigments were dominated by yellow pigments with a few red pigments derivatives. Neither the presence of peptone nor ammonium sulfate promoted the production of intracellular orange pigments while extracellular pigments with an orangish red color were observed in both cases, with a higher yield when peptone was used. Two-stage pH control fermentation was then performed to improve desirable pigments yield and further investigate the effect of pH and nitrogen sources on pigments composition. These results provide a useful strategy to produce Monascus pigments with different composition and different color characteristics. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  7. Pigment production from a mangrove Penicillium | Chintapenta ...

    African Journals Online (AJOL)

    A mangrove Penicillium producing red pigment was cultured in an optimized medium that was designed by the authors previously and used in this study. The purpose of this study was to identify the pigment and also to study the effect of bio elements on pigment production. Pigment from the medium was efficiently extracted ...

  8. Pigment production from a mangrove Penicillium

    African Journals Online (AJOL)

    SAM

    2014-06-25

    Jun 25, 2014 ... A mangrove Penicillium producing red pigment was cultured in an optimized medium that was designed by the authors previously and used in this study. The purpose of this study was to identify the pigment and also to study the effect of bio elements on pigment production. Pigment from the medium was.

  9. Oral pigmentation induced by Premarin.

    Science.gov (United States)

    Pérusse, R; Morency, R

    1991-07-01

    Pigmented lesions of the oral cavity are important entities. The wide range of their clinical differential diagnosis includes such diverse systemic conditions as Addison's disease, Peutz-Jeghers syndrome, malignant melanoma, Kaposi's sarcoma, as well as specific oral lesions, such as amalgam tattoo or gingival melanosis. This paper reports a very rare cause of oral pigmentation, a melanic type, related to the use of Premarin.

  10. In situ DRIFTS investigation of NH3-SCR reaction over CeO2/zirconium phosphate catalyst

    Science.gov (United States)

    Zhang, Qiulin; Fan, Jie; Ning, Ping; Song, Zhongxian; Liu, Xin; Wang, Lanying; Wang, Jing; Wang, Huimin; Long, Kaixian

    2018-03-01

    A series of ceria modified zirconium phosphate catalysts were synthesized for selective catalytic reduction of NO with ammonia (NH3-SCR). Over 98% NOx conversion and 98% N2 selectivity were obtained by the CeO2/ZrP catalyst with 20 wt.% CeO2 loading at 250-425 °C. The interaction between CeO2 and zirconium phosphate enhanced the redox abilities and surface acidities of the catalysts, resulting in the improvement of NH3-SCR activity. The in situ DRIFTS results indicated that the NH3-SCR reaction over the catalysts followed both Eley-Rideal and Langmuir-Hinshelwood mechanisms. The amide (sbnd NH2) groups and the NH4+ bonded to Brønsted acid sites were the important intermediates of Eley-Rideal mechanism.

  11. Kinetically controlled fabrication of gold nanorods and investigation of their thermal stability via in-situ TEM heating

    Science.gov (United States)

    Chankhunthod, N.; Aslam, Z.; Critchley, K.; Evans, S. D.; Brydson, R.

    2017-09-01

    Size controlled CTAB-capped AuNRs with various aspect ratios (ARs) ranging from 1.63±0.13 to 4.12±0.25 were synthesized following a modified seed-mediated method. Their thermal stability was examined by in-situ TEM heating. The results revealed a structural change from rods to spheres with increasing temperature. At lower temperatures 600ºC, particles became increasingly spherical. This behaviour occurred at temperatures lower than the melting point of bulk gold supporting a surface diffusion mechanism with material diffusing from the tips and redepositing at the middle of the rods. The rate of change in AR appeared to increase for thinner AuNRs.

  12. Enhanced visible-light induced degradation of benzene on Mg-ferrite/hematite/PANI nanospheres: In situ FTIR investigation

    International Nuclear Information System (INIS)

    Shen, Yu; Zhao, Qidong; Li, Xinyong; Yuan, Deling; Hou, Yang; Liu, Shaomin

    2012-01-01

    Graphical abstract: The dramatic enhanced visible-light photocatalytic activity of Mg-ferrite/hematite nanospheres photocatalyst on benzene were obtained after hybridized by polyaniline (PANI) using the chemisorption method. The enhancement of photocatalytic degradation of benzene under visible-light irradiation was mainly ascribed to the high efficiency of charge separation induced by the hybrid effect of PANI and Mg-ferrite/hematite. By using the in situ FTIR technique, ethyl acetate, carboxylic acid and aldehyde could be regarded as the intermediate products, and CO 2 is produced as the final product during the reaction process. Highlights: ► Mg-ferrite/hematite/PANI photocatalysts showed enhanced photocatalytic activity. ► Ethyl acetate, carboxylic acid and aldehyde were the intermediate products. ► CO 2 was produced as the final product during the reaction process. ► The high efficiency of charge separation was mainly ascribed to the hybrid effect. - Abstract: The dramatic enhanced visible-light photocatalytic activity of Mg-ferrite/hematite nanospheres photocatalysts on benzene were obtained after hybridized by polyaniline (PANI) using the chemisorption method. The samples were characterized by scanning electron microscope, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectra and UV–Vis diffuse reflectance spectroscopy. The enhancement of photocatalytic degradation of benzene under visible-light irradiation was mainly ascribed to the high efficiency of charge separation induced by the hybrid effect of PANI and Mg-ferrite/hematite. By using the in situ FTIR technique, ethyl acetate, carboxylic acid and aldehyde could be regarded as the intermediate products, and CO 2 is determined as the final product during the reaction process.

  13. Analysis of Indian pigment gallstones

    International Nuclear Information System (INIS)

    Rautray, T.R.; Vijayan, V.; Panigrahi, S.

    2007-01-01

    Particle induced X-ray emission and particle induced γ-ray emission spectroscopic techniques have been carried out to analyse the elemental concentrations of human pigment gallstone samples from eastern region (Orissa) and southern region (Chennai) of India. It was observed that 18 minor/trace elements namely Na, Mg, Al, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br and Pb were present in the pigment gallstone samples of both the regions. Our study reveals that average concentration of all elements except Ni in south Indian pigment gallstone samples is higher than that of corresponding values in east Indian pigment gallstone samples whereas elements like Al, P, S, Cl and V did not show much variation between these two regions. Fourier transform infra-red analysis was carried out to identify the functional groups and the classification of the pigment type gallstones of both the regions. The thermal behaviour of pigment gallstones was carried out by thermogravimetry-derivative thermogravimetry analysis

  14. Drusenoid retinal pigment epithelium detachments

    Directory of Open Access Journals (Sweden)

    Miguel Hage Amaro

    2015-10-01

    Full Text Available ABSTRACT The authors make a review of drusenoid retinal pigment epithelium detachments(DPDs, a form of retinal pigment epithelium detachment(PED that evolves from confluent and large soft drusen.Drusenoidretinal pigment epithelial detachments are a recognized element of the "dry" AMD. Until now, no treatment is indicated in drusenoid PEDs. The authors describe the clinical characteristics of drusenoid retinal pigment epithelium detachments (DPEDs and make a review of the DPEDs related in the international literature. We related in this revision paper the multimodal advanced image exams in two cases of dusenoid retinal pigment epithelium detachments (DPEDs and the general characteristics of thisfinding associated with Dry Macular degeneration.Upon examination of the ocular fundusDPEDs emerge as well-circumscribed yellow or yellow–white elevations of the RPE that are usually found within the macula.They may show scalloped borders and a slightly irregular surface. When visualized using fluorescein angiography (FA,DPEDs are typically described as faint hyper-fluorescent in the early phase followed by a slow increase in fluorescence throughout the transit stage of the study without late leakage. With optical coherence tomography (OCT, drusenoid PEDs usually show a smooth contour of the detached hyperreflective RPE band that may have an undulating appearance.Drusenoid PEDs encompass far above the ground possibility type of "dry" AMD that develops in relationship with large confluent soft drusen.At this point no treatment is utilized in drusenoid retinal pigment epithelium detachment(DPEDs.

  15. Investigating the etiology of bovine digital dermatitis by a combination of 16S rRNA gene analysis and fluorescence in situ hybridization

    DEFF Research Database (Denmark)

    Schou, Kirstine Klitgaard; Rasmussen, Marianne; Capion, Nynne

    , and the current view on this disease points towards a complicated etiology involving co-infection of more than one, and probably multiple species belonging to the genus Treponema. Still, the pathogenic role of each of the digital dermatitis-associated phylotypes remains unclear. The aim of this investigation...... of the disease. Here, a PCR-based approach targeting the 16S rRNA gene along with fluorescence in situ hybridization was used to determine the prevalence and diversity of 17 Treponema phylotypes in 85 digital dermatitis lesions from six Danish dairy herds as well as additional biopsies of healthy skin...

  16. In-situ neutron investigation of hydrogen absorption kinetics in La(FexSi1-x)13 magnetocaloric alloys for room-temperature refrigeration application

    Science.gov (United States)

    Hai, Xueying; Mayer, Charlotte; Colin, Claire V.; Miraglia, Salvatore

    2016-02-01

    Promising magnetocaloric material La(Fe,Si)13 with a first-order magnetic transition has been widely investigated. The observed instability of hydrogen in the material is detrimental for its industrial upscale and a better control of the hydrogen absorption/desorption is necessary to optimize its application potential. In this article, the hydrogen absorption kinetics is studied through an in-situ neutron diffraction experiment. The results allow us to have an inside look at the structure "breathing" to accommodate the interstitial atoms and compare the effect of hydrides with carbohydrides.

  17. In situ soft X-ray absorption spectroscopy investigation of electrochemical corrosion of copper in aqueous NaHCO3 solution

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Peng; Chen, Jeng-Lung; Borondics, Ferenc; Glans, Per-Anders; West, Mark W.; Chang, Ching-Lin; Salmeron, Miquel; Guo, Jinghua

    2010-03-31

    A novel electrochemical setup has been developed for soft x-ray absorption studies of the electronic structure of electrode materials during electrochemical cycling. In this communication we illustrate the operation of the cell with a study of the corrosion behavior of copper in aqueous NaHCO3 solution via the electrochemically induced changes of its electronic structure. This development opens the way for in situ investigations of electrochemical processes, photovoltaics, batteries, fuel cells, water splitting, corrosion, electrodeposition, and a variety of important biological processes.

  18. Study of the scattering of the light in aqueous samples collagen in the presence of nanoparticles and curcuma pigment

    Science.gov (United States)

    Silva, F. M. L.; Alencar, L. D. S.; Bernardi, M. I. B.; Lima, F. W. S.; Melo, C. A. S.

    2015-06-01

    In this work we investigate the scattering of light in means turbid in the presence or not of pigment and nanoparticles. For this we initially using a sample of collagen from means turbid with and without the presence of curcuma pigments and nanoparticles. Our results show that the light scattering is more intense in the samples with nanoparticles and curcuma pigment.

  19. Visual pigment spectra of the comma butterfly, Polygonia c-album, derived from in vivo epi-illumination nation microspectrophotometry

    NARCIS (Netherlands)

    Vanhoutte, KJA; Stavenga, DG

    The visual pigments in the compound eye of the comma butterfly, Polygonia c-album, were investigate in a specially designed epi-illumination microspectrophotometer. Absorption changes due to photochemical conversions of the visual pigments, or due to light-independent visual pigment decay and

  20. Yolk pigments of the Mexican leaf frog.

    Science.gov (United States)

    Marinetti, G V; Bagnara, J T

    1983-02-25

    Eggs of the Mexican leaf frog contain blue and yellow pigments identified as biliverdin and lutein, respectively. Both pigments are bound to proteins that occur in crystalline form in the yolk platelet. The major blue pigment is biliverdin IX alpha. The eggs vary in color from brilliant blue to pale yellow-green depending on the amount of each pigment. These pigments may provide protective coloration to the eggs.

  1. Zinc deficiency leads to lipofuscin accumulation in the retinal pigment epithelium of pigmented rats.

    Directory of Open Access Journals (Sweden)

    Sylvie Julien

    Full Text Available BACKGROUND: Age-related macular degeneration (AMD is associated with lipofuscin accumulation whereas the content of melanosomes decreases. Melanosomes are the main storage of zinc in the pigmented tissues. Since the elderly population, as the most affected group for AMD, is prone to zinc deficit, we investigated the chemical and ultrastructural effects of zinc deficiency in pigmented rat eyes after a six-month zinc penury diet. METHODOLOGY/PRINCIPAL FINDINGS: Adult Long Evans (LE rats were investigated. The control animals were fed with a normal alimentation whereas the zinc-deficiency rats (ZD-LE were fed with a zinc deficient diet for six months. Quantitative Energy Dispersive X-ray (EDX microanalysis yielded the zinc mole fractions of melanosomes in the retinal pigment epithelium (RPE. The lateral resolution of the analysis was 100 nm. The zinc mole fractions of melanosomes were significantly smaller in the RPE of ZD-LE rats as compared to the LE control rats. Light, fluorescence and electron microscopy, as well as immunohistochemistry were performed. The numbers of lipofuscin granules in the RPE and of infiltrated cells (Ø>3 µm found in the choroid were quantified. The number of lipofuscin granules significantly increased in ZD-LE as compared to control rats. Infiltrated cells bigger than 3 µm were only detected in the choroid of ZD-LE animals. Moreover, the thickness of the Bruch's membrane of ZD-LE rats varied between 0.4-3 µm and thin, rangy ED1 positive macrophages were found attached at these sites of Bruch's membrane or even inside it. CONCLUSIONS/SIGNIFICANCE: In pigmented rats, zinc deficiency yielded an accumulation of lipofuscin in the RPE and of large pigmented macrophages in the choroids as well as the appearance of thin, rangy macrophages at Bruch's membrane. Moreover, we showed that a zinc diet reduced the zinc mole fraction of melanosomes in the RPE and modulated the thickness of the Bruch's membrane.

  2. In situ investigation of the mechanisms of the transport to tissues of polycyclic aromatic hydrocarbons adsorbed onto the root surface of Kandelia obovata seedlings

    International Nuclear Information System (INIS)

    Li, Ruilong; Zhu, Yaxian; Zhang, Yong

    2015-01-01

    A novel method for in situ determination of the polycyclic aromatic hydrocarbons (PAHs) adsorbed onto the root surface of Kandelia obovata seedlings was established using laser-induced time-resolved nanosecond fluorescence spectroscopy (LITRF). The linear dynamic ranges for the established method were 1.5–1240 ng/spot for phenanthrene, 1.0–1360 ng/spot for pyrene and 5.0–1220 ng/spot for benzo[a]pyrene. Then, the mechanisms of PAHs transport from the Ko root surface to tissues were investigated. The three-phase model including fast, slow and very slow fractions was superior to the single or dual-phase model to describe the PAHs transport processes. Moreover, the fast fraction of PAHs transport process was mainly due to passive movement, while the slow and very slow fractions were not. Passive movement was the main process of B[a]P adsorbed onto Ko root surface transport to tissues. In addition, the extent of the PAHs transport to Ko root tissues at different salinity were evaluated. - Highlights: • A novel method in situ determination PAHs adsorbed onto root surface was established. • The mechanisms of PAHs transport from root surface to tissues are investigated. • Passive movement is the main process of B[a]P transport from root surface to tissues. • Effects of salinity on the PAHs transport from root surface to tissues are evaluated. - Passive movement for the PAHs adsorbed onto Kandelia obovata root surface to tissues was observed by a newly established in situ LITRF method

  3. Effect of newly developed pigments and ultraviolet absorbers on the color change of pigmented silicone elastomer

    Directory of Open Access Journals (Sweden)

    Mohit G Kheur

    2017-01-01

    Conclusion: The newly developed pigment led to increased color stability as compared to commercially available pigments. Addition of UV stabilizer, Chimassorb led to a further reduction in color change of the pigmented elastomer.

  4. Investigation on a new method to in-situ distinguish the deposition tile with the junction defect tile

    Science.gov (United States)

    Cai, Laizhong; Liu, Jian; Gauthier, Eric; Corre, Yann; SWIP Collaboration; CEA IRFM Collaboration

    2013-10-01

    The behaviors of plasma facing components(PFC) are major concerns for tokamaks, in particular, for steady state operations. Some PFC tiles show abnormal high surface temperature than others when thermal steady state is reached, which is believed to be caused by the deposition layer on the tile or the junction defect of the sandwich PFC tile. Although carbon deposit tiles and junction defect tiles present similar thermal response, the deposition layer and junction delamination have different effects to the tile lifetime. Delamination could bring a critical failure of the tile and then influence the steady state operation. The defect tile needs to be replaced before failure although the replacement is difficult, whereas the deposition tile does not impact on the PFC lifetime and easy to be cleaned. Therefore, trying in-situ to distinguish deposited tiles and junction defect tiles is crucial to avoid a critical failure. More, the junction defect is related to not only repetitive heat pulses but also manufacture. It is possible a junction defect tile exists in the deposition area or even both junction defect and deposition layer appear on the same tile. This makes the discrimination more complicated and obligatory. In this paper, thermal behaviors of junction defect tiles and carbon deposit tiles are simulated. A modified time constant method is introduce and then the feasibility of discrimination by analyzing the thermal behaviors of tiles is discussed. Requirements of this method for discrimination are also described.

  5. An Investigation of Operational Decision Making in Situ: Incident Command in the U.K. Fire and Rescue Service.

    Science.gov (United States)

    Cohen-Hatton, Sabrina R; Butler, Philip C; Honey, Robert C

    2015-08-01

    The aim of this study was to better understand the nature of decision making at operational incidents in order to inform operational guidance and training. Normative models of decision making have been adopted in the guidance and training for emergency services. In these models, it is assumed that decision makers assess the current situation, formulate plans, and then execute the plans. However, our understanding of how decision making unfolds at operational incidents remains limited. Incident commanders, attending 33 incidents across six U.K. Fire and Rescue Services, were fitted with helmet-mounted cameras, and the resulting video footage was later independently coded and used to prompt participants to provide a running commentary concerning their decisions. The analysis revealed that assessment of the operational situation was most often followed by plan execution rather than plan formulation, and there was little evidence of prospection about the potential consequences of actions. This pattern of results was consistent across different types of incident, characterized by level of risk and time pressure, but was affected by the operational experience of the participants. Decision making did not follow the sequence of phases assumed by normative models and conveyed in current operational guidance but instead was influenced by both reflective and reflexive processes. These results have clear implications for understanding operational decision making as it occurs in situ and suggest a need for future guidance and training to acknowledge the role of reflexive processes. © 2015, Human Factors and Ergonomics Society.

  6. Investigation on microstructure and thermal properties of in-situ synthesized Cu-ZrO{sub 2} nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Elmahdy, Marwa [Higher Technological Institute, Tenth of Ramadan (Egypt). Mechanical Dept.; Abouelmagd, Gamal; Mazen, Asaad A. [Minia Univ. (Egypt). Production Engineering and Design Dept.

    2017-12-15

    Cu-ZrO{sub 2} nanocomposites were prepared by an in-situ reactive synthesis of copper nitrate Cu(NO{sub 3}){sub 2} and zirconium oxychloride ZrOCl{sub 2}. Zirconia (ZrO{sub 2}) was added by 2.5, 5 and 10 wt.% to the Cu matrix to assess its effect on thermal conductivity and thermal expansion behavior. The results showed that ZrO{sub 2} nanoparticles (30-50 nm) were homogeneously distributed in the copper matrix. The measured thermal conductivity for the Cu-ZrO{sub 2} nanocomposites decreased from 372.8 to 94.4 W m{sup -1} K{sup -1} with increasing ZrO{sub 2} content from 0 to 10 wt.%. Cu-10 wt.% ZrO{sub 2} nanocomposite yields a low thermal conductivity of 94.4 W . m{sup -1} K{sup -1} along with a low coefficient of thermal expansion, 11.47 x 10{sup -6} K{sup -1}.

  7. Water jet perforation: a new method of completing and simulating in situ leaching wells. Report of investigations

    International Nuclear Information System (INIS)

    Savanick, G.A.; Krawza, W.G.

    1981-10-01

    The Bureau of Mines has designed, fabricated, and field tested a water jet cutting device capable of perforating nonmetallic well casings for the purpose of completing or stimulating in situ uranium leaching wells. The device is lowered into the wellbore, where it issues a high-velocity water jet that penetrates either a polyvinyl chloride or fiberglass casing, cement, and from 1 to 4 feet into the surrounding uraniferous sandstone. The resulting perforations allow leaching solution to pass between the sandstone and the wellbore. This report describes the water jet perforator, tells how it is used, presents cost data, and discusses the results of laboratory and field tests. The tests were designed to (1) determine the optimum operating conditions for water jet perforation, (2) assess the effects of changes in these conditions, (3) evaluate the performance of the water jet perforator under actual conditions, and (4) compare this method with other methods of well completion. These tests showed that water jet perforation is superior to conventional well completion methods for selectively achieving communication between the wellbore and adjacent sand while maintaining sand control, for restoring permeability lost through wellbore damage, for stimulating poorly performing wells for completing wells with casings that have inside diameters as small as 2 inches, and for extending the effective well diameter

  8. A new system for sodium flux growth of bulk GaN. Part II: in situ investigation of growth processes

    KAUST Repository

    Von Dollen, Paul

    2016-09-09

    We report recent results of bulk GaN crystal growth using the sodium flux method in a new crucible-free growth system. We observed a (0001) Ga face (+c-plane) growth rate >50 µm/h for growth at a N2 overpressure of ~5 MPa and 860 °C, which is the highest crystal growth rate reported for this technique to date. Omega X-ray rocking curve (ω-XRC) measurements indicated the presence of multiple grains, though full width at half maximum (FWHM) values for individual peaks were <100 arcseconds. Oxygen impurity concentrations as measured by secondary ion mass spectroscopy (SIMS) were >1020 atoms/cm3. By monitoring the nitrogen pressure decay over the course of the crystal growth, we developed an in situ method that correlates gas phase changes with precipitation of GaN from the sodium-gallium melt. Based on this analysis, the growth rate may have actually been as high as 90 µm/h, as it would suggest GaN growth ceased prior to the end of the run. We also observed gas phase behavior identified as likely characteristic of GaN polynucleation.

  9. High-voltage electron-microscope investigation of point-defect agglomerates in irradiated copper during in-situ annealing

    International Nuclear Information System (INIS)

    Jaeger, W.; Urban, K.; Frank, W.

    1980-01-01

    Thin copper foils were irradiated with 650 keV electrons at 10 K in a high-voltage electron microscope (HVEM) to doses phi in the range 2 x 10 23 electrons/m 2 approximately 25 electrons /m 2 and then annealed in situ up to room temperature and outside the HVEM between room temperature and 470 K. During irradiation visible defect clusters were formed only at phi >= 2.5 x 10 24 electrons/m 2 . At smaller doses defect clusters became visible after annealing at 50 K. Between 50 K and 120 K further clusters, mainly dislocation loops on brace111 planes, appeared. Above 120 K, particularly between 160 K and 300 K, some of the dislocation loops became glissile. They glided out of the specimens or agglomerated to larger clusters of frequently complex shapes. As a consequence between 160 K and 300 K the cluster density decreased strongly, whereas the mean cluster size increased monotonously through the entire range of annealing temperatures covered. Contrast analyses between 180 K and 400 K revealed that the great majority of the dislocation loops were of interstitial type. At 470 K a new type of small clusters emerged, presumably of vacancy type. These observations are compared with other studies on electron-irradiated copper and with the current models of radiation damage in metals. (author)

  10. A new system for sodium flux growth of bulk GaN. Part II: in situ investigation of growth processes

    Science.gov (United States)

    Von Dollen, Paul; Pimputkar, Siddha; Alreesh, Mohammed Abo; Nakamura, Shuji; Speck, James S.

    2016-12-01

    We report recent results of bulk GaN crystal growth using the sodium flux method in a new crucible-free growth system. We observed a (0001) Ga face (+c-plane) growth rate >50 μm/h for growth at a N2 overpressure of 5 MPa and 860 °C, which is the highest crystal growth rate reported for this technique to date. Omega X-ray rocking curve (ω-XRC) measurements indicated the presence of multiple grains, though full width at half maximum (FWHM) values for individual peaks were 1020 atoms/cm3. By monitoring the nitrogen pressure decay over the course of the crystal growth, we developed an in situ method that correlates gas phase changes with precipitation of GaN from the sodium-gallium melt. Based on this analysis, the growth rate may have actually been as high as 90 μm/h, as it would suggest GaN growth ceased prior to the end of the run. We also observed gas phase behavior identified as likely characteristic of GaN polynucleation.

  11. In-situ USAXS/SAXS Investigation of Tunable Structural Color in Amorphous Photonic Crystals During Electrophoretic Deposition

    Science.gov (United States)

    Bukosky, Scott; Hammons, Joshua; Han, Jinkyu; Freyman, Megan; Lee, Elaine; Cook, Caitlyn; Kuntz, Joshua; Worsley, Marcus; Han, Thomas Yong; Ristenpart, William; Pascall, Andrew

    2017-11-01

    Amorphous photonic crystals (APCs) formed via electrophoretic deposition (EPD) exhibit non-iridescent, angle-independent, structural colors believed to arise from changes in the particle-particle interactions and inter-particle spacing, representing a potential new paradigm for display technologies. However, particle dynamics on nanometer length scales that govern the displayed color, crystallinity, and other characteristics of the photonic structures, are not well understood. In this work, in-situ USAXS/SAXS studies of three-dimensional colloidal particle arrays were performed in order to identify their structural response to applied external electric fields. These results were compared to simultaneously acquired UV-Vis spectra to tie the overall electrically induced structure of the APCs directly to the observed changes in visible color. The structural evolution of the APCs provides new information regarding the correlation between nano-scale particle-particle interactions and the corresponding optical response. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-736068.

  12. Investigation of Antisite Defect Formation and Chemical Expansion in LiNiPO4 by in Situ Neutron Diffraction.

    Science.gov (United States)

    Jacas Biendicho, Jordi; Hsiao, Kuang-Che; Hull, Stephen; West, Anthony R

    2017-03-20

    In situ neutron diffraction was used to characterize the effect of temperature on the crystal structure of LiNiPO 4 . LiNiPO 4 adopts an ordered olivine structure at room temperature, but, with increasing temperature, this work shows that a significant amount of Li and Ni cation exchange occurs, for example, ∼15% at 900 °C. The antisite disorder is detected by residual nuclear densities on the M1 and M2 octahedral sites in the olivine structure using difference Fourier maps and by changes in cation site occupancies, lattice parameters, and mean ⟨M-O⟩ bond distances. The antisite disorder is also responsible for chemical expansion of the crystal lattice in addition to thermal expansion. Antisite defect formation at high temperature and its reversibility on cooling can be understood as an entropically driven feature of the crystal structure of LiNiPO 4 . The lithium ion diffusion pathway, that follows a curved trajectory along the b axis in the olivine structure, is, therefore, susceptible to be blocked if synthesis conditions are not carefully controlled and should also be influenced by the chemically expanded lattice of the disordered structure if this is preserved to ambient temperature by rapid cooling.

  13. In-situ TEM investigations of graphic-epitaxy and small particles. Final Report, 1 January-31 December 1982

    International Nuclear Information System (INIS)

    Heinemann, K.

    1983-01-01

    Palladium was deposited inside a controlled-vacuum specimen chamber of a transmission electron microscope (TEM) onto MgO and alpha-alumina substrate surfaces. Annealing and various effects of gas exposure of the particulate Pd deposits were studied in-situ by high resolution TEM and electron diffraction. Whereas substrate temperatures of 500 C or annealing of room temperature (RT) deposits to 500 C were needed to obtain epitaxy on sapphire, RT deposits on MgO were perfectly epitaxial. For Pd/MgO a lattice expansion of 2 to 4% was noted the highest values of expansion were found for the smallest particles. The lattice expansion of small Pd particles on alumina substrates was less than 1%. Long-time RT exposure of Pd/MgO in a vacuum yielded some moblity and coalescence events, but notably fewer than for Pd on sapphire. Exposure to air or oxygen greatly enhanced the particle mobility and coalescence and also resulted in the flattening of Pd particles on MgO substrates. Electron-beam irradiation further enhanced this effect. Exposure to air for several tens of hours of Pd/MgO led to strong coalescence

  14. Nanoflaky MnO2/functionalized carbon nanotubes for supercapacitors: an in situ X-ray absorption spectroscopic investigation

    Science.gov (United States)

    Chang, Han-Wei; Lu, Ying-Rui; Chen, Jeng-Lung; Chen, Chi-Liang; Lee, Jyh-Fu; Chen, Jin-Ming; Tsai, Yu-Chen; Chang, Chien-Min; Yeh, Ping-Hung; Chou, Wu-Ching; Liou, Ya-Hsuan; Dong, Chung-Li

    2015-01-01

    The surfaces of acid- and amine-functionalized carbon nanotubes (C-CNT and N-CNT) were decorated with MnO2 nanoflakes as supercapacitors by a spontaneous redox reaction. C-CNT was found to have a lower edge plane structure and fewer defect sites than N-CNT. MnO2/C-CNT with a highly developed surface area exhibited favorable electrochemical performance. To determine the atomic/electronic structures of the MnO2/functionalized CNTs (MnO2/C-CNT and MnO/N-CNT) during the charge/discharge process, in situ X-ray absorption spectroscopy (XAS) measurements were made at the Mn K-edge. Both C-CNT and N-CNT are highly conductive. The effect of the scan rate on the capacitance behavior was also examined, revealing that the π* state of CNT and the size of the tunnels in pseudo-capacitor materials (which facilitate conduction and the transport of electrolyte ions) are critical for the capacitive performance, and their role depends on the scan rate. In the slow charge/discharge process, MnO2/N-CNT has a more symmetrical rectangular cyclic voltammetry (CV) curve. In the fast charge/discharge process, MnO2/C-CNT with a highly developed surface provides fast electronic and ionic channels that support a reversible faradaic redox reaction between MnO2 nanoflakes and the electrolyte, significantly enhancing its capacitive performance over that of MnO2/N-CNT. The MnO2/C-CNT architecture has great potential for supercapacitor applications. The information that was obtained herein helps to elucidate CNT surface modification and the design of the MnO2/functionalized CNT interface with a view for the further development of supercapacitors. This work, and especially the combination of CV with in situ XAS measurements, will be of value to readers with an interest in nanomaterial, nanotechnology and their applications in energy storage.The surfaces of acid- and amine-functionalized carbon nanotubes (C-CNT and N-CNT) were decorated with MnO2 nanoflakes as supercapacitors by a spontaneous redox

  15. Electron paramagnetic resonance and fluorescence in situ hybridization-based investigations of individual doses for persons living at Metlino in the upper reaches of the Techa River.

    Science.gov (United States)

    Degteva, Marina O; Anspaugh, Lynn R; Akleyev, Alexander V; Jacob, Peter; Ivanov, Denis V; Wieser, Albrecht; Vorobiova, Marina I; Shishkina, Elena A; Shved, Valentina A; Vozilova, Alexandra; Bayankin, Sergey N; Napier, Bruce A

    2005-02-01

    with the estimates derived from the use of the TRDS-2000. For all persons investigated according to each technique, the EPR-measured dose to enamel was 0.55 +/- 0.17 Gy, and the TRDS-2000 prediction for the dose to enamel for these individuals is 0.55 +/- 0.07 Gy. The fluorescence in situ hybridization-based dose, 0.38 +/- 0.10 Gy, compared well to the TRDS-2000 prediction of external dose, 0.31 +/- 0.03 Gy, to red bone marrow for these persons. Validation of external doses at the remaining villages is an active area of investigation.

  16. Diversity and functional properties of bistable pigments.

    Science.gov (United States)

    Tsukamoto, Hisao; Terakita, Akihisa

    2010-11-01

    Rhodopsin and related opsin-based pigments, which are photosensitive membrane proteins, have been extensively studied using a wide variety of techniques, with rhodopsin being the most understood G protein-coupled receptor (GPCR). Animals use various opsin-based pigments for vision and a wide variety of non-visual functions. Many functionally varied pigments are roughly divided into two kinds, based on their photoreaction: bistable and monostable pigments. Bistable pigments are thermally stable before and after photo-activation, but monostable pigments are stable only before activation. Here, we review the diversity of bistable pigments and their molecular characteristics. We also discuss the mechanisms underlying different molecular characteristics of bistable and monostable pigments. In addition, the potential of bistable pigments as a GPCR model is proposed.

  17. A unique visual pigment expressed in green, red and deep-red receptors in the eye of the small white butterfly, Pieris rapae crucivora

    NARCIS (Netherlands)

    Wakakuwa, M; Stavenga, DG; Kurasawa, M; Arikawa, K

    The full primary structure of a long-wavelength absorbing visual pigment of the small white butterfly, Pieris rapae crucivora, was determined by molecular cloning. In situ hybridization of the opsin mRNA of the novel visual pigment (PrL) demonstrated that it is expressed in the two distal

  18. The Phototoxicity of Blue Light on the Functional Properties of the Retinal Pigment Epithelium

    Science.gov (United States)

    1989-05-01

    The phototoxic effect of blue light on isolated pigment epithelium will be investigated. The emphasis will be on functional changes rather than a...integrity of the barrier system and the transport system and the transport systems known to operate in the pigment epithelium. The effects of blue ... light on leucine transport across the isolated bovine retinal pigment epithelium (RPE) have been continued to determine if Vitamin E and melatonin

  19. A comprehensive study of eco-friendly natural pigment and its applications

    OpenAIRE

    Parmar, Ramendra Singh; Singh, Charu

    2017-01-01

    Actinomycetes, a large group of filamentous bacteria account for 70–80% of secondary metabolites available commercially. The present investigation was undertaken with an aim to identify and characterize pigment from actinomycetes. Actinomycetes were isolated from rhizosphere soil samples collected from different regions of Madhya Pradesh state. Out of 85 actinomycetes, only 5 actinomycetes showed pigment production and based on diffusible pigment production ability one actinomycete ARITM02 wa...

  20. High-Capacitance Mechanism for Ti3C2Tx MXene by in Situ Electrochemical Raman Spectroscopy Investigation.

    Science.gov (United States)

    Hu, Minmin; Li, Zhaojin; Hu, Tao; Zhu, Shihao; Zhang, Chao; Wang, Xiaohui

    2016-12-27

    MXenes represent an emerging family of conductive two-dimensional materials. Their representative, Ti 3 C 2 T x , has been recognized as an outstanding member in the field of electrochemical energy storage. However, an in-depth understanding of fundamental processes responsible for the superior capacitance of Ti 3 C 2 T x MXene in acidic electrolytes is lacking. Here, to understand the mechanism of capacitance in Ti 3 C 2 T x MXene, we studied electrochemically the charge/discharge processes of Ti 3 C 2 T x electrodes in sulfate ion-containing aqueous electrolytes with three different cations, coupled with in situ Raman spectroscopy. It is demonstrated that hydronium in the H 2 SO 4 electrolyte bonds with the terminal O in the negative electrode upon discharging while debonding occurs upon charging. Correspondingly, the reversible bonding/debonding changes the valence state of Ti element in the MXene, giving rise to the pseudocapacitance in the acidic electrolyte. In stark contrast, only electric double layer capacitance is recognized in the other electrolytes of (NH 4 ) 2 SO 4 or MgSO 4 . The charge storage ways also differ: ion exchange dominates in H 2 SO 4 , while counterion adsorption in the rest. Hydronium that is characterized by smaller hydration radius and less charge is the most mobile among the three cations, facilitating it more kinetically accommodated on the deep adsorption sites between the MXene layers. The two key factors, i.e., surface functional group-involved bonding/debonding-induced pseudocapacitance, and ion exchange-featured charge storage, simultaneously contribute to the superior capacitance of Ti 3 C 2 T x MXene in acidic electrolytes.

  1. Modelling the Small Throw Fault Effect on the Stability of a Mining Roadway and Its Verification by In Situ Investigation

    Directory of Open Access Journals (Sweden)

    Małkowski Piotr

    2017-12-01

    Full Text Available The small throw fault zones cause serious problems for mining engineers. The knowledge about the range of fractured zone around the roadway and about roadway’s contour deformations helps a lot with the right support design or its reinforcement. The paper presents the results of numerical analysis of the effect of a small throw fault zone on the convergence of the mining roadway and the extent of the fracturing induced around the roadway. The computations were performed on a dozen physical models featuring various parameters of rock mass and support for the purpose to select the settings that reflects most suitably the behavior of tectonically disturbed and undisturbed rocks around the roadway. Finally, the results of the calculations were verified by comparing them with in situ convergence measurements carried out in the maingate D-2 in the “Borynia-Zofiówka-Jastrzębie” coal mine. Based on the results of measurements it may be concluded that the rock mass displacements around a roadway section within a fault zone during a year were four times in average greater than in the section tectonically unaffected. The results of numerical calculations show that extent of the yielding zone in the roof reaches two times the throw of the fault, in the floor 3 times the throw, and horizontally approx. 1.5 to 1.8 times the width of modelled fault zone. Only a few elasto-plastic models or models with joints between the rock beds can be recommended for predicting the performance of a roadway which is within a fault zone. It is possible, using these models, to design the roadway support of sufficient load bearing capacity at the tectonically disturbed section.

  2. Melanoma or Pseudo melanoma Change in a pigmented lesion after application of topical 5-Fluorouracil

    Science.gov (United States)

    2017-10-26

    traumatized nevi4 . Flourescent in-situ hybridiation ( FISH ) can be a helpful adjuvant test in categorizing atypical melanocytic proliferations into...and 97%, respectively; however, melanomas can be negative for FISH aberrations 5 . This case was negative for the FISH alterations. FISH analysis of 5...pigment and sub-epidermal clefting. Fluorescent in-situ hybridization ( FISH ) was performed on additional sections and did not demonstrate chromosomal

  3. In-situ investigation of martensite formation in AISI 52100 bearing steel at sub-zero Celsius temperature

    DEFF Research Database (Denmark)

    Villa, Matteo; Hansen, Mikkel Fougt; Pantleon, Karen

    2013-01-01

    Martensite formation in AISI 52100 bearing steel at sub-zero Celsius temperature was investigated with Vibrating Sample Magnetometry. The investigation reports the stabilization of retained austenite in quenched samples during storage at room temperature and reveals the thermally activated nature...

  4. Iris pigmentation and AC thresholds.

    Science.gov (United States)

    Roche, A F; Mukherjee, D; Chumlea, W C; Siervogel, R M

    1983-03-01

    Data from 160 White children were used to analyze possible associations between iris pigmentation and AC pure-tone thresholds. Iris pigmentation was graded from iris color using glass models of eyes, and AC thresholds were obtained under carefully controlled conditions. Analyses of variance using two groupings of iris color grades showed no evidence of an association between iris color grade and AC thresholds. Furthermore, inspection of arrays of the actual glass eye models, in conjunction with the order of mean thresholds at each test frequency, did not indicate the presence of an association between iris color grades and thresholds. It was concluded that while iris pigmentation may be related to some aspects of hearing ability, it does not appear to be related to AC thresholds in children.

  5. Modulation of Calcium Oxalate Crystallization by Proteins and Small Molecules Investigated by In Situ Atomic Force Microscopy

    Science.gov (United States)

    Qiu, R.; Orme, C.; Cody, A. M.; Wierzbicki, A.; Hoyer, J.; Nancollas, G.; de Yoreo, J.

    2002-12-01

    Understanding the physical mechanisms by which biological inhibitors control nucleation and growth of inorganic crystals is a major focus of biomineral research. Calcium oxalate monohydrate (COM), which plays a functional role in plant physiology, is also a source of pathogenesis in humans where it causes kidney stone disease. Although a great deal of research has been carried out on the modulation COM by proteins and small molecules, the basic mechanism has not yet been understood. However, because the proteins that play a role in COM growth have been identified and sequenced, COM provides an excellent model system for research into biomineral growth. In this study, in situ atomic force microscopy (AFM) was used to monitor the COM surface under controlled growth conditions both from pure solutions and those doped with citrate and osteopontin (OPN) in order to determine their effects on surface morphology and growth dynamics at the molecular level. As with other solution-grown crystals such as calcite, COM grows on complex dislocation hillocks. In pure solution, while growth on the (010) face is isotropic, hillocks on the (-101) face exhibit anisotropic step kinetics. Steps of [-10-1] and orientation are clearly delineated with the [-10-1] being the fast growing direction. When citrate is added to the solution, both growth rate and morphology are drastically changed on (-101) face, especially along the [-10-1] direction. This results in isotropic disc-shaped hillocks a shape that is then reflected in the macroscopic growth habit. In contrast, no large growth changes were observed on the (010) facet. At the same time, molecular modeling predicts an excellent fit of the citrate ion into the (-101) plane and a poor fit to the (010) face. Here we propose a model that reconciles the step-specific interactions implied by the AFM results with the face-specific predictions of the calculations. Finally, we present the results of doping with aspartic acid as well as OPN, an

  6. In-situ Optical Spectroscopy Investigation of Water and Its influence on Forsterite Transformation in Supercritical CO2

    Science.gov (United States)

    Wang, Z.; Thompson, C. J.; Joly, A. G.; Sklarew, D. S.; Poindexter, L.; Rosso, K. M.

    2009-12-01

    Carbon capture and sequestration (CCS) from coal/gas-burning power plants is currently viewed as one of the most promising technologies for mitigating green house gas emissions. This strategy involves injection of supercritical CO2 (scCO2) into deep geological formations such as depleted oil and gas reservoirs and deep saline aquifers. The feasibility of this approach and the ultimate fate of the stored CO2 are determined by the interactions between scCO2, various minerals in the rock formations, and the host fluids. Currently, there is only limited knowledge about both the thermodynamic and kinetic aspects of the physical and chemical processes that occur between scCO2 and relevant minerals, such as metal silicates and metal aluminosilicates, and the role of water activity for catalyzing mineral transformation reactions. In this work, we have developed a modular in situ optical spectroscopic platform that integrates a scCO2 generation and manipulation system with an array of optical and laser spectroscopies including UV-visible, IR, Raman and laser fluorescence spectroscopy. We have used the system to study i) the dissolution and quantification of H2O/D2O in scCO2 and ii) interaction between scCO2 and a model metal silicate, forsterite (Mg2SiO4), and the effects of the presence of water under variable pressure, temperature and water content. Our results showed that H2O and D2O have unique IR spectral features over a broad spectral range from 700 cm-1 to ~ 2900 cm-1 in scCO2 and their concentrations are directly proportional to the characteristic IR bands that correspond to their stretching (D2O) and bending frequencies (both D2O and H2O). These bands offer a unique spectroscopic signature useful for qualitative and quantitative analysis of the properties and reactivity of small amounts of H2O in scCO2. metal carbonation reactions relevant to sequestration.

  7. Prescribers' interactions with medication alerts at the point of prescribing: A multi-method, in situ investigation of the human-computer interaction.

    Science.gov (United States)

    Russ, Alissa L; Zillich, Alan J; McManus, M Sue; Doebbeling, Bradley N; Saleem, Jason J

    2012-04-01

    Few studies have examined prescribers' interactions with medication alerts at the point of prescribing. We conducted an in situ, human factors investigation of outpatient prescribing to uncover factors that influence the prescriber-alert interaction and identify strategies to improve alert design. Field observations and interviews were conducted with outpatient prescribers at a major Veterans Affairs Medical Center. Physicians, clinical pharmacists, and nurse practitioners were recruited across five primary care clinics and eight specialty clinics. Prescribers were observed in situ as they ordered medications for patients and resolved alerts. Researchers collected 351 pages of typed notes across 102 hours of observations and interviews. An interdisciplinary team identified emergent themes via inductive qualitative analysis. Altogether, 320 alerts were observed among 30 prescribers and their interactions with 146 patients. Qualitative analysis uncovered 44 emergent themes and 9 overarching factors, which were organized into a framework that describes the prescriber-alert interaction. Prescribers' ability to act on alerts was impeded by the alert interface, which did not adequately support all prescriber types. This empiric study produced a novel framework for understanding the prescriber-alert interaction. Results revealed key components of the alert interface that influence prescribers and indicate a need for more universal design. Actionable design recommendations are presented and may be used to enhance alert design and patient safety. Published by Elsevier Ireland Ltd.

  8. 2D BiOCl/Bi12O17Cl2 nanojunction: Enhanced visible light photocatalytic NO removal and in situ DRIFTS investigation

    Science.gov (United States)

    Zhang, Wendong; Dong, Xin'an; Jia, Bin; Zhong, Junbo; Sun, Yanjuan; Dong, Fan

    2018-02-01

    Novel two-dimensional (2D) BiOCl/Bi12O17Cl2 nanojunctions were fabricated by a facile one-pot in situ method at room temperature. The as-prepared samples were analyzed by XRD, SEM, TEM, HRTEM, UV-vis DRS, PL, ESR and BET-BJH measurement in detail. The photocatalytic performance of the samples was evaluated by removal of NO at ppb level under visible-light illumination. The result reveals that the BiOCl/Bi12O17Cl2 nanojunctions manifests conspicuously enhanced photocatalytic efficiency for NO removal. The facilitated performance can be ascribed to the well-matched band structure and relatively high specific surface area. In addition, the in situ diffuse reflectance infrared Fourier transform spectroscopy was applied to investigate the adsorption and photocatalytic NO oxidation processes. The reaction mechanism of photocatalytic NO oxidation was proposed based on the observed intermediates. The present work could pave a way to synthesize novel visible light photocatalysts at room temperature for environmental application.

  9. In-situ investigation of the order-disorder transition in Cu2ZnSnSe4 by optical transmission spectroscopy

    Directory of Open Access Journals (Sweden)

    Christiane Stroth

    2017-02-01

    Full Text Available The existence of disorder is one possible reason for the limited performance of kesterite solar cells. Therefore further knowledge of the order-disorder phase transition, of factors which influence the degree of order and of methods to determine this material property is still required. In this study we investigated the order-disorder transition in the kesterite material Cu2ZnSnSe4 by in-situ optical transmission spectroscopy during heat treatments. We show in-situ results for the temperature dependence of the band gap and its tailing properties. The influence of cooling rates on the phase transition was analyzed as well as the ordering kinetics during annealing at a constant temperature. The critical temperature of the phase transition was determined and the existence of a control temperature range is shown, which allows for controlling the degree of order by the cooling rate within this range. Additionally we performed Raman analysis to link Raman spectra to the degree of order in Cu2ZnSnSe4. A correlation between the intensity ratio of A-modes as well as B-/ E- Raman modes and the degree of order was found.

  10. Investigation of the Microstructure Evolution and Deformation Mechanisms of a Mg-Zn-Zr-RE Twin-Roll-Cast Magnesium Sheet by In-Situ Experimental Techniques.

    Science.gov (United States)

    Máthis, Kristián; Horváth, Klaudia; Farkas, Gergely; Choe, Heeman; Shin, Kwang Seon; Vinogradov, Alexei

    2018-01-27

    Twin roll casting (TRC), with a relatively fast solidification rate, is an excellent production method with promising potential for producing wrought semi or final Mg alloy products that can often suffer from poor formability. We investigate in this study the effect of the TRC method and the subsequent heat treatment on the microstructure and deformation mechanisms in Mg-Zn-Zr-Nd alloy deformed at room temperature using the in-situ neutron diffraction and acoustic emission techniques and ex-situ texture measurement and microscopy, respectively. Although a higher work hardening is observed in the rolling direction due to the more intensive -type dislocation activity, the difference in the mechanical properties of the specimens deformed in the RD and TD directions is small in the as-rolled condition. An additional heat treatment results in recrystallization and significant anisotropy in the deformation. Due to the easier activation of the extension twinning in the TD given by texture, the yield stress in the TD is approximately 40% lower than that in the RD.

  11. Investigation of the Lobular Carcinoma in Situ, Using Molecular Genetic Techniques, for the Involvement of Novel Genes

    National Research Council Canada - National Science Library

    Mastracci, Teresa L; Andrulis, Irene L

    2005-01-01

    .... Our study proposes to investigate LN lesions, lacking any adjacent invasive carcinoma, for alterations in and expression of known and novel genes/proteins with the goal of characterizing a molecular genetic profile...

  12. Investigation of the Lobular Carcinoma in Situ, Using Molecular Genetic Techniques, for the Involvement of Novel Genes

    National Research Council Canada - National Science Library

    Mastracci, Teresa

    2004-01-01

    .... Our study proposes to investigate LN lesions, lacking any adjacent invasive carcinoma, for alterations in and expression of known and novel genes/proteins in order to characterize a profile for lobular neoplasia...

  13. Pigmented Bowen’s disease presenting with a “starburst” pattern

    Science.gov (United States)

    Maione, Vincenzo; Errichetti, Enzo; Roussel, Sara Laurent; Lebbé, Celeste

    2016-01-01

    Pigmented Bowen’s disease (pBD) is an uncommon in situ squamous cell carcinoma of the skin usually presenting as a dark scaly plaque involving chronically exposed sites, which is not uncommonly mistaken for other similar pigmented lesions, such as melanoma, pigmented basal cell carcinoma or seborrheic keratosis [1,2]. Dermoscopy has been proven to improve its diagnosis by showing several findings, i.e., gray/brownish dots in linear arrangement, scales, coiled vessels, focal/multifocal amorphous hypopigmentation and bluish structureless areas [1,2]. However, pBD may sometimes display dermoscopic features which are typical of other pigmented lesions, thus making its recognition quite troublesome despite the use of dermoscopy [1,2]. We report a case of pBD with a “starburst” pattern, discussing its dermoscopic differential diagnosis. PMID:27867748

  14. In situ characterization of martian materials and detection of organic compounds with the MOMA investigation onboard the ExoMars rover

    Science.gov (United States)

    Arevalo, R. D., Jr.; Grubisic, A.; van Amerom, F. H. W.; Danell, R.; Li, X.; Kaplan, D.; Pinnick, V. T.; Brinckerhoff, W. B.; Getty, S.; Goesmann, F.

    2017-12-01

    Ground-based observations (e.g., via the NASA Infrared Telescope Facility) and in situ investigations, including flybys (e.g., Mariner Program), orbiters (most recently MAVEN and ExoMars TGO), stationary landers (i.e., Viking, Pathfinder and Phoenix), and mobile rovers (i.e., Sojourner, Spirit/Opportunity and Curiosity), have enabled the progressive exploration of the Martian surface. Evidence for liquid water, manifest as hydrated and amorphous materials representative of alteration products of primary minerals/lithologies, and geomorphological features such as recurring slope lineae (RSL), valley networks and open-basin lakes, indicates that Mars may have hosted habitable environments, at least on local scales (temporally and spatially). However, the preservation potential of molecular biosignatures in the upper meter(s) of the surface is limited by destructive cosmic radiation and oxidative chemical reactions. Moreover, the determination of indigenous versus exogenous origins, and biotic versus abiotic formation mechanisms of detected organic material, provide additional challenges for future missions to the red planet. The Mars Organic Molecule Analyzer (MOMA) onboard the ExoMars rover, set to launch in 2020, provides an unprecedented opportunity to discover unambiguous indicators of life. The MOMA instrument will investigate the compositions of materials collected during multiple vertical surveys, extending as deep as two meters below the surface, via: i) gas chromatography mass spectrometry, a method geared towards the detection of volatile organics and the determination of molecular chirality, mapping to previous in situ Mars investigations; and, ii) laser desorption mass spectrometry, a technique commonly employed in research laboratories to detect larger, more refractory organic materials, but a first for spaceflight applications. Selective ion excitation and tandem mass spectrometry (MS/MS) techniques support the isolation and disambiguation of complex

  15. Prodigiosin pigment of Serratia marcescens is associated with increased biomass production.

    Science.gov (United States)

    Haddix, Pryce L; Shanks, Robert M Q

    2018-04-03

    Serratia marcescens is a gram-negative, facultatively-anaerobic bacterium and opportunistic pathogen which produces the red pigment prodigiosin. We employed both batch culture and chemostat growth methods to investigate prodigiosin function in the producing organism. Pigmentation correlated with an increased rate of ATP production during population lag phase. Results with a lacZ transcriptional fusion to the prodigiosin (pig) biosynthetic operon revealed that operon transcription is activated by low cellular levels of ATP at high cell density. Furthermore, these data enabled estimation of the ATP per cell minimum value at which the operon is induced. Pigmented cells were found to accumulate ATP more rapidly and to multiply more quickly than non-pigmented cells during the high density growth phase. Finally, results with both batch and chemostat culture revealed that pigmented cells grow to approximately twice the biomass yield as non-pigmented S. marcescens bacteria. Prodigiosin production may, therefore, provide a growth advantage at ambient temperatures.

  16. Enhancing the chroma of pigmented polymers using antireflective surface structures

    DEFF Research Database (Denmark)

    Clausen, Jeppe Sandvik; Christiansen, Alexander Bruun; Kristensen, Anders

    2013-01-01

    In this paper we investigate how the color of a pigmented polymer is affected by reduction of the reflectance at the air-polymer interface. Both theoretical and experimental investigations show modified diffuse-direct reflectance spectra when the reflectance of the surface is lowered. Specifically...

  17. PHYTOPLANKTON PIGMENT ANALYSIS BY HPLC FOR ASSESSING COMMUNITY COMPOSITION IN THE LAURENTIAN GREAT LAKES

    Science.gov (United States)

    A technique to rapidly assess phytoplankton dynamics is being evaluated for its utility in the Great Lakes. Comparison to traditional microscopic techniques and to more recent in-situ FluoroProbe technology will allow us to determine if HPLC pigment analysis can provide unique a...

  18. Enhancing Dark Shade Pigment Dyeing of Cotton Fabric Using Plasma Treatment

    Directory of Open Access Journals (Sweden)

    Chi-Wai Kan

    2017-07-01

    Full Text Available This study is intended to investigate the effect of atmospheric pressure plasma treatment on dark shade pigment dyeing of cotton fabric. Experimental results reveal that plasma-treated cotton fabric can attain better color yield, levelness, and crocking fastness in dark shade pigment dyeing, compared with normal cotton fabric (not plasma treated. SEM analysis indicates that cracks and grooves were formed on the cotton fiber surface where the pigment and the binder can get deposited and improve the color yield, levelness, and crocking fastness. It was also noticed that pigment was aggregated when deposited on the fiber surface which could affect the final color properties.

  19. Estimating water stressed dwarf green bean pigment concentration through hyperspectral indices

    International Nuclear Information System (INIS)

    Koksal, E.S.; Ustrun, H.; Ozcan, H.; Gunturk, A.

    2010-01-01

    In this study, the relationship between leaf pigment concentration (analyzed in the laboratory) and four spectral indexes (measured in the field) was investigated. For this purpose, field experiments consisting of six different irrigation treatments were conducted with dwarf green beans during 2005 growing season. Based on spectral data, spectral indexes were plotted against pigment concentration. Results showed that under water stress, the chlorophyll and carotene contents of green bean leaves rose. According to linear regression analysis between spectral indexes and pigment contents, the Normalized Difference Pigment Chlorophyll Index (NPCI) and Normalized Difference Vegetation Index (NDVI) had the highest correlations with the chlorophyll (a, b and total), and carotene content of leaves. (author)

  20. In situ Raman Spectroscopy Investigation of Siderite Dissolution in Aqueous Fluids up to 400°C

    Science.gov (United States)

    Marocchi, M.; Bureau, H.; Fiquet, G.; Guyot, F. J.

    2010-12-01

    Detailed studies of devolatilization reactions, fluid-rock interactions and metamorphic transformations occurring in subducting slabs play a key role in unraveling the complex physical-chemical transformations of crust and mantle at convergent margins and in the understanding of fluids and element fluxes involved. One of the main characteristics of subduction zones is the presence of water released from oceanic lithosphere that interacts with mantle wedge rocks. In particular, reaction of water with ferrous iron-rich minerals contained in ultramafic rocks can develop highly reducing conditions and generation of H2 during serpentinization. Fluids interacting with peridotite in this temperature range may have important biological implications and play a key role on metasomatism of the forearc mantle. In particular, the dissolution of Fe-bearing minerals can be responsible for the generation of reactive reduced species, as is the case, for example, of deep-sea hydrothermal systems (cf Seewald et al., 2006). For a better understanding of these processes, H2 and CO2 generation can be monitored by experiments at the P and T conditions expected during subduction and serpentinization at shallow levels. Experiments on dissolution of iron (II) carbonate (FeCO3 siderite) in aqueous fluids (pure water, saline solution and ammonium solution) have been performed at temperatures up to 400°C and pressures in the range 730-1150 MPa using an externally heated hydrothermal diamond anvil cell (HDAC). In situ Raman spectroscopy allowed direct characterization of the new phases and of the C-O-H-N species dissolved in the aqueous fluid. For the simplest C-O-H aqueous system (H2O and H2O-NaCl) we document reduction of oxidized carbon to organic molecules (formaldehyde and formic acid) and H2 production in the fluid. HDAC quenched samples characterized at room temperature and pressure by Raman spectroscopy and SEM (Scanning Electron Microscopy) have also revealed the occurrence of complex

  1. In situ spectroscopic investigation of the cobalt-catalyzed oxidation of lignin model compounds in ionic liquids

    NARCIS (Netherlands)

    Zakzeski, J.|info:eu-repo/dai/nl/326160256; Bruijnincx, P.C.A.|info:eu-repo/dai/nl/33799529X; Weckhuysen, B.M.|info:eu-repo/dai/nl/285484397

    2011-01-01

    The cobalt-catalyzed oxidation of lignin and lignin model compounds using molecular oxygen in ionic liquids proceeds readily under mild conditions, but mechanistic insight and evidence for the species involved in the catalytic cycle is lacking. In this study, a spectroscopic investigation of the

  2. Multiple pigment cell types contribute to the black, blue, and orange ornaments of male guppies (Poecilia reticulata).

    Science.gov (United States)

    Kottler, Verena A; Koch, Iris; Flötenmeyer, Matthias; Hashimoto, Hisashi; Weigel, Detlef; Dreyer, Christine

    2014-01-01

    The fitness of male guppies (Poecilia reticulata) highly depends on the size and number of their black, blue, and orange ornaments. Recently, progress has been made regarding the genetic mechanisms underlying male guppy pigment pattern formation, but we still know little about the pigment cell organization within these ornaments. Here, we investigate the pigment cell distribution within the black, blue, and orange trunk spots and selected fin color patterns of guppy males from three genetically divergent strains using transmission electron microscopy. We identified three types of pigment cells and found that at least two of these contribute to each color trait. Further, two pigment cell layers, one in the dermis and the other in the hypodermis, contribute to each trunk spot. The pigment cell organization within the black and orange trunk spots was similar between strains. The presence of iridophores in each of the investigated color traits is consistent with a key role for this pigment cell type in guppy color pattern formation.

  3. Do seasonal profiles of foliar pigments improve species discrimination of evergreen coastal tree species in KwaZulu- Natal, South Africa?

    CSIR Research Space (South Africa)

    Van Deventer, Heidi

    2013-04-01

    Full Text Available pigments, as well as improve species discrimination. This study investigated the potential of seasonal pigment profiles (for foliar carotenoid and total chlorophyll) in improving species discrimination for trees using leaf spectral data. Our aims were to (i...

  4. In-situ investigation of adsorption of dye and coadsorbates on TiO 2 films using QCM-D, fluorescence and AFM techniques

    KAUST Repository

    Harms, Hauke A.

    2013-09-11

    Simultaneous adsorption of dye molecules and coadsorbates is important for the fabrication of high-efficiency dyesensitized solar cells, but its mechanism is not well understood. Herein, we use a quartz crystal microbalance with dissipation technique (QCM-D) to study dynamically and quantitatively the sensitization of TiO2 in situ. We investigate dye loading for a ruthenium(II) polypyridyl complex (Z907), of a triphenylamine-based D-π-A dye (Y123), and of a ullazine sensitizer (JD21), as well as the simultaneous adsorption of the latter two with the coadsorbate chenodeoxycholic acid. By combining the QCM-D technique with fluorescence measurements, we quantify molar ratios between the dye and coadsorbate. Furthermore, we will present first studies using liquid-phase AFM on the adsorbed dye monolayer, thus obtaining complementary microscopic information that may lead to understanding of the adsorption mechanism on the molecular scale. © 2013 SPIE.

  5. Formation of Copper Catalysts for CO2 Reduction with High Ethylene/Methane Product Ratio Investigated with In Situ X-ray Absorption Spectroscopy.

    Science.gov (United States)

    Eilert, André; Roberts, F Sloan; Friebel, Daniel; Nilsson, Anders

    2016-04-21

    Nanostructured copper cathodes are among the most efficient and selective catalysts to date for making multicarbon products from the electrochemical carbon dioxide reduction reaction (CO2RR). We report an in situ X-ray absorption spectroscopy investigation of the formation of a copper nanocube CO2RR catalyst with high activity that highly favors ethylene over methane production. The results show that the precursor for the copper nanocube formation is copper(I)-oxide, not copper(I)-chloride as previously assumed. A second route to an electrochemically similar material via a copper(II)-carbonate/hydroxide is also reported. This study highlights the importance of using oxidized copper precursors for constructing selective CO2 reduction catalysts and shows the precursor oxidation state does not affect the electrocatalyst selectivity toward ethylene formation.

  6. In situ investigations on the impact of heat production and gamma radiation with regard to high-level radioactive waste disposal in rock salt formations

    International Nuclear Information System (INIS)

    Rothfuchs, T.

    1986-01-01

    Deep geological formations especially rock salt formations, are considered worldwide as suitable media for the final disposal of radioactive high-level waste (HLW). In the Federal Republic of Germany, the Institut fur Tieflagerung of the Gesellschaft fur Strahlen- und Umweltforschung mbH Munchen operates the Asse Salt Mine as a pilot facility for testing the behavior of an underground nuclear waste repository. The tests are performed using heat and radiation sources to simulate disposed HLW canisters. The measured data obtained since 1965 show that the thermomechanical response of the salt formation and the physical/chemical changes in the vicinity of disposal boreholes are not a serious concern and that their long-term consequences can be estimated based on theoretical considerations and in-situ investigations

  7. In-situ investigation of adsorption of dye and coadsorbates on TiO2 films using QCM-D, fluorescence and AFM techniques

    Science.gov (United States)

    Harms, Hauke A.; Tétreault, Nicolas; Voitchovsky, Kislon; Stellacci, Francesco; Grätzel, Michael

    2013-09-01

    Simultaneous adsorption of dye molecules and coadsorbates is important for the fabrication of high-efficiency dyesensitized solar cells, but its mechanism is not well understood. Herein, we use a quartz crystal microbalance with dissipation technique (QCM-D) to study dynamically and quantitatively the sensitization of TiO2 in situ. We investigate dye loading for a ruthenium(II) polypyridyl complex (Z907), of a triphenylamine-based D-π-A dye (Y123), and of a ullazine sensitizer (JD21), as well as the simultaneous adsorption of the latter two with the coadsorbate chenodeoxycholic acid. By combining the QCM-D technique with fluorescence measurements, we quantify molar ratios between the dye and coadsorbate. Furthermore, we will present first studies using liquid-phase AFM on the adsorbed dye monolayer, thus obtaining complementary microscopic information that may lead to understanding of the adsorption mechanism on the molecular scale.

  8. Small molecule screening identifies targetable zebrafish pigmentation pathways

    DEFF Research Database (Denmark)

    Colanesi, Sarah; Taylor, Kerrie L; Temperley, Nicholas D

    2012-01-01

    Small molecules complement genetic mutants and can be used to probe pigment cell biology by inhibiting specific proteins or pathways. Here, we present the results of a screen of active compounds for those that affect the processes of melanocyte and iridophore development in zebrafish and investig......Small molecules complement genetic mutants and can be used to probe pigment cell biology by inhibiting specific proteins or pathways. Here, we present the results of a screen of active compounds for those that affect the processes of melanocyte and iridophore development in zebrafish...... and investigate the effects of a few of these compounds in further detail. We identified and confirmed 57 compounds that altered pigment cell patterning, number, survival, or differentiation. Additional tissue targets and toxicity of small molecules are also discussed. Given that the majority of cell types...

  9. Primary pigmented nodular adrenocortical disease

    Directory of Open Access Journals (Sweden)

    Marie T Manipadam

    2011-01-01

    Full Text Available Primary pigmented nodular adrenocortical disease (PPNAD is a rare cause of ACTH-independent Cushing′s syndrome and has characteristic gross and microscopic pathologic findings. We report a case of PPNAD in a 15-year-old boy, which was not associated with Carney′s complex. Bilateral adrenalectomy is the treatment of choice.

  10. Key factors for UV curable pigment dispersions

    International Nuclear Information System (INIS)

    Magny, B.; Pezron, E.; Ciceron, P.H.; Askienazy, A.

    1999-01-01

    UV oligomers with good pigment dispersion are needed to allow good formulation flexibility and possibility to apply thinner films. Pigment dispersion mainly depends on three phenomena: the wetting of agglomerates, the breakage of agglomerates by mechanical stress and the stabilization of smaller agglomerates and primary particles against flocculation. It has been shown that oligomers with low viscosity and low surface tension induce a good pigment wetting. Examples of monomers and oligomers for good pigment dispersion are given

  11. Non-destructive in situ study of “Mad Meg” by Pieter Bruegel the Elder using mobile X-ray fluorescence, X-ray diffraction and Raman spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Van de Voorde, Lien, E-mail: lien.vandevoorde@ugent.be [Ghent University, Department of Analytical Chemistry, X-ray Microspectroscopy and Imaging Research Group, Krijgslaan 281 S12, B-9000 Gent (Belgium); Van Pevenage, Jolien [Ghent University, Department of Analytical Chemistry, Raman Spectroscopy Research Group, Krijgslaan 281 S12, B-9000 Gent (Belgium); De Langhe, Kaat [Ghent University, Department of Archaeology, Archaeometry Research Group, Sint-Pietersnieuwstraat 35, B-9000 Gent (Belgium); De Wolf, Robin; Vekemans, Bart; Vincze, Laszlo [Ghent University, Department of Analytical Chemistry, X-ray Microspectroscopy and Imaging Research Group, Krijgslaan 281 S12, B-9000 Gent (Belgium); Vandenabeele, Peter [Ghent University, Department of Archaeology, Archaeometry Research Group, Sint-Pietersnieuwstraat 35, B-9000 Gent (Belgium); Martens, Maximiliaan P.J. [Ghent University, Department of Art, Music and Theatre Sciences, Blandijnberg 2, B-9000 Gent (Belgium)

    2014-07-01

    “Mad Meg”, a figure of Flemish folklore, is the subject of a famous oil-on-panel painting by the Flemish renaissance artist Pieter Bruegel the Elder, exhibited in the Museum Mayer van den Bergh (Antwerp, Belgium). This article reports on the in situ chemical characterization of this masterpiece by using currently available state-of-the-art portable analytical instruments. The applied non-destructive analytical approach involved the use of a) handheld X-ray fluorescence instrumentation for retrieving elemental information and b) portable X-ray fluorescence/X-ray diffraction instrumentation and laser-based Raman spectrometers for obtaining structural/molecular information. Next to material characterization of the used pigments and of the different preparation layers of the painting, also the verification of two important historical iconographic hypotheses is performed concerning the economic way of painting by Brueghel, and whether or not he used blue smalt pigment for painting the boat that appears towards the top of the painting. The pigments identified are smalt pigment (65% SiO{sub 2} + 15% K{sub 2}O + 10% CoO + 5% Al{sub 2}O{sub 3}) for the blue color present in all blue areas of the painting, probably copper resinate for the green colors, vermillion (HgS) as red pigment and lead white is used to form different colors. The comparison of blue pigments used on different areas of the painting gives no differences in the elemental fingerprint which confirms the existing hypothesis concerning the economic painting method by Bruegel. - Highlights: • In situ, non-destructive investigation of a famous painting by Pieter Bruegel. • Use of a new, commercial available, portable XRF/XRD instrumentation. • Multi-methodological approach: make also use of a mobile Raman spectrometer. • Used pigments and different preparation layers of the painting are characterized. • The verification of two important historical iconographic hypotheses are performed.

  12. 21 CFR 73.352 - Paracoccus pigment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Paracoccus pigment. 73.352 Section 73.352 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.352 Paracoccus pigment. (a) Identity. (1) The color additive paracoccus pigment consists of the heat-killed, dried cells of a nonpathogenic and nontoxicogenic strain of...

  13. Swapping one red pigment for another.

    Science.gov (United States)

    Davies, Kevin M

    2015-01-01

    Betalains are bright red and yellow pigments, which are produced in only one order of plants, the Caryophyllales, and replace the more familiar anthocyanin pigments. The evolutionary origin of betalain production is a mystery, but a new study has identified the first regulator of betalain production and discovered a previously unknown link between the two pigment pathways.

  14. Seperation, identification and analysis of pigment (melanin ...

    African Journals Online (AJOL)

    Nine strains among 180 Streptomyces isolates produce a diffusible dark brown pigment on both peptone-yeast extract agar and synthetic tyrosine-agar. They also show the positive reaction to Ltyrosine or L-dopa substrates. The pigment has been referred to be as merely as dark brown watersoluble pigment, as melanoid or ...

  15. Long-term pigment dynamics and diatom survival in dark sediment

    NARCIS (Netherlands)

    Veuger, B.; Van Oevelen, D.

    2011-01-01

    In order to investigate survival of diatoms and long-term pigment dynamics in dark sediment, we incubated samples of homogenized, sieved, tidal-flat sediment for 1 yr in darkness. Microscopic observations revealed that some diatoms survived the full year in darkness and retained their pigments.

  16. Bioactive compounds in pigmented rice bran inhibit growth of human cancer cells

    Science.gov (United States)

    Rice bran contains both lipophilic and hydrophilic antioxidants. Our previous studies have shown that pigmented rice cultivars contained several-fold higher total phenolic concentrations and antioxidant capacities than non-pigmented cultivars. We investigated three rice brans (purple, red and light-...

  17. Fungal pigments inhibit the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis of darkly pigmented fungi.

    Science.gov (United States)

    Buskirk, Amanda D; Hettick, Justin M; Chipinda, Itai; Law, Brandon F; Siegel, Paul D; Slaven, James E; Green, Brett J; Beezhold, Donald H

    2011-04-01

    Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been used to discriminate moniliaceous fungal species; however, darkly pigmented fungi yield poor fingerprint mass spectra that contain few peaks of low relative abundance. In this study, the effect of dark fungal pigments on the observed MALDI mass spectra was investigated. Peptide and protein samples containing varying concentrations of synthetic melanin or fungal pigments extracted from Aspergillus niger were analyzed by MALDI-TOF and MALDI-qTOF (quadrupole TOF) MS. Signal suppression was observed in samples containing greater than 250ng/μl pigment. Microscopic examination of the MALDI sample deposit was usually heterogeneous, with regions of high pigment concentration appearing as black. Acquisition of MALDI mass spectra from these darkly pigmented regions of the sample deposit yielded poor or no [M+H](+) ion signal. In contrast, nonpigmented regions within the sample deposit and hyphal negative control extracts of A. niger were not inhibited. This study demonstrated that dark fungal pigments inhibited the desorption/ionization process during MALDI-MS; however, these fungi may be successfully analyzed by MALDI-TOF MS when culture methods that suppress pigment expression are used. The addition of tricyclazole to the fungal growth media blocks fungal melanin synthesis and results in less melanized fungi that may be analyzed by MALDI-TOF MS. Published by Elsevier Inc.

  18. A new challenge: in-situ investigation of the elusive nanostructures in wet halite and clay using BIB/FIB-cryo-SEM methods

    Science.gov (United States)

    Desbois, G.; Urai, J. L.

    2009-04-01

    Mudrocks and saltrocks form seals for hydrocarbon accumulations, aquitards and chemical barriers. The sealing capacity is controlled either by the rock microstructure or by chemical interactions between minerals and the permeating fluid. A detailed knowledge about the sealing characteristics is of particular interest in Petroleum Sciences. Other fields of interest are the storage of anthropogenic carbon dioxide and radioactive waste in geologic formations. A key factor to the understanding of sealing by mudstones and saltrocks is the study of their porosity. However, Halite and clay are so fluids sensitive that investigation on dried samples required by traditional methods of investigations (metal injection methods [6],[3]; magnetic susceptibility measurement [4]; SEM imaging of broken surfaces [5] and CT scanner computing [7]) are critical for robust interpretation. In one hand, none of these methods is able to directly describe the in-situ porosity at the pore scale and on the other hand, most of these methods require dried samples in which the natural structure of pores could be damaged due to the desiccation, dehydration and dissolution-recrystallisation of the fabric. SEM imaging is certainly the most direct approach to investigate the porosity but it is generally limited by the poor quality of the mechanically prepared surfaces. This problem is solved by the recent development of ion milling tools (FIB: Focussed Ion Beam or BIB: Broad Ion Beam, which allows producing in-situ high quality polished cross-sections suitable for high resolution pores SEM imaging at nano-scale. More over, new and innovative developments of the cryo-SEM approach in the Geosciences allow investigating samples under wet natural conditions. Thus, we are developing the combination of FIB/BIB-cryo-SEM methods ([1],[2]), which combine in one machine the vitrification of the pore fluids by very rapid cooling, the excavation of the sample by ion milling tool and SEM imaging. By these, we

  19. Evaluation of shape and size effects on optical properties of ZnO pigment

    International Nuclear Information System (INIS)

    Kiomarsipour, Narges; Shoja Razavi, Reza; Ghani, Kamal; Kioumarsipour, Marjan

    2013-01-01

    The pigment with optimized morphology would attain maximum diffuse solar reflectance at a lower film thickness and reduce the pigment volume concentration required. This factor would contribute to a reduction in overall weight and possibly extend the durability of the system to longer time scales, specially in space assets. In the present work, five different morphologies of ZnO pigment were synthesized by hydrothermal method. The ZnO pigments were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM) and N 2 adsorption (BET). The optical property of the ZnO pigments was investigated by UV/VIS/NIR spectrophotometer. The results indicated that the optical properties of ZnO powders were strongly affected by the particle size and morphology. The nanorods and microrods ZnO structures showed the minimum spectral reflectance in visible and near infrared regions, whereas the novel nanoparticle-decorated ZnO pigment revealed the maximum spectral reflectance in the same regions. The reflectance spectra of scale-like and submicrorods ZnO were in the middle of the others. The higher surface roughness led to higher light scattering in nanoparticle-decorated ZnO pigment and multiple-scattering in them. These results proved that a significant improvement in the scattering efficiency of ZnO pigment can be realized by utilizing an optimized nanoparticle-decorated pigment.

  20. The Contribution of Risk Factors to the Higher Incidence of Invasive and In Situ Breast Cancers in Women With Higher Levels of Education in the European Prospective Investigation Into Cancer and Nutrition

    NARCIS (Netherlands)

    Menvielle, Gwenn; Kunst, Anton E.; van Gils, Carla H.; Peeters, Petra H.; Boshuizen, Hendriek; Overvad, Kim; Olsen, Anja; Tjonneland, Anne; Hermann, Silke; Kaaks, Rudolf; Bergmann, Manuela M.; Illner, Anne-Kathrin; Lagiou, Pagona; Trichopoulos, Dimitrios; Trichopoulou, Antonia; Palli, Domenico; Berrino, Franco; Mattiello, Amelia; Tumino, Rosario; Sacerdote, Carlotta; May, Anne; Monninkhof, Evelyn; Braaten, Tonje; Lund, Eiliv; Ramon Quiros, Jose; Duell, Eric J.; Sanchez, Maria-Jose; Navarro, Carmen; Ardanaz, Eva; Borgquist, Signe; Manjer, Jonas; Khaw, Kay Tee; Allen, Naomi E.; Reeves, Gillian K.; Chajes, Veronique; Rinaldi, Sabina; Slimani, Nadia; Gallo, Valentina; Vineis, Paolo; Riboli, Elio; Bueno-de-Mesquita, H. Bas

    2011-01-01

    The authors investigated the role of known risk factors in educational differences in breast cancer incidence. Analyses were based on the European Prospective Investigation Into Cancer and Nutrition and included 242,095 women, 433 cases of in situ breast cancer, and 4,469 cases of invasive breast

  1. The contribution of risk factors to the higher incidence of invasive and in situ breast cancers in women with higher levels of education in the European prospective investigation into cancer and nutrition

    NARCIS (Netherlands)

    Menvielle, Gwenn; Kunst, Anton E.; van Gils, Carla H.; Peeters, Petra H.; Boshuizen, Hendriek; Overvad, Kim; Olsen, Anja; Tjonneland, Anne; Hermann, Silke; Kaaks, Rudolf; Bergmann, Manuela M.; Illner, Anne-Kathrin; Lagiou, Pagona; Trichopoulos, Dimitrios; Trichopoulou, Antonia; Palli, Domenico; Berrino, Franco; Mattiello, Amelia; Tumino, Rosario; Sacerdote, Carlotta; May, Anne; Monninkhof, Evelyn; Braaten, Tonje; Lund, Eiliv; Quirós, José Ramón; Duell, Eric J.; Sánchez, Maria-José; Navarro, Carmen; Ardanaz, Eva; Borgquist, Signe; Manjer, Jonas; Khaw, Kay Tee; Allen, Naomi E.; Reeves, Gillian K.; Chajes, Véronique; Rinaldi, Sabina; Slimani, Nadia; Gallo, Valentina; Vineis, Paolo; Riboli, Elio; Bueno-de-Mesquita, H. Bas

    2011-01-01

    The authors investigated the role of known risk factors in educational differences in breast cancer incidence. Analyses were based on the European Prospective Investigation Into Cancer and Nutrition and included 242,095 women, 433 cases of in situ breast cancer, and 4,469 cases of invasive breast

  2. Investigation and Application of a New Passive Sampling Technique for in Situ Monitoring of Illicit Drugs in Waste Waters and Rivers.

    Science.gov (United States)

    Guo, Changsheng; Zhang, Tingting; Hou, Song; Lv, Jiapei; Zhang, Yuan; Wu, Fengchang; Hua, Zhendong; Meng, Wei; Zhang, Hao; Xu, Jian

    2017-08-15

    Illicit drugs constitute a class of emerging contaminants that has been drawing significant concern due to its potent pharmacological and biological activities. In this study, an in situ passive sampling approach that uses diffusive gradients in thin films (DGT) was successfully tested for measuring ketamine (KET), methamphetamine (METH), and amphetamine (AMP) in water. The diffusion coefficients of KET, METH, and AMP in diffusive gel were (8.13 ± 0.12) × 10 -6 , (8.55 ± 0.14) × 10 -6 , and (7.72 ± 0.18) × 10 -6 cm 2 s -1 at 22 °C, respectively. The capacities of an XAD binding gel for KET, METH, and AMP were 92, 57, and 45 μg per binding gel disc, which were suitable for long-term environmental monitoring. The DGT measurement of these drugs was not influenced by the pH (4 to 9) and the ionic strength (0.001 M - 0.1 M) and unaffected by the water flow, demonstrating the effectiveness of the XAD-based DGT for the in situ monitoring of illicit drugs. DGT samplers were deployed in a WWTP influent and natural rivers in Beijing, China. The ng L -1 levels of the drugs were high in the wastewater influent and low in river waters, with an insignificant fluctuation during the seven-day monitoring. The DGT-measured concentrations were comparable to the average concentrations determined by SPE method, which suggested that the average data measured by DGT could be substituted for high-frequency grab sampling. This study has demonstrated systematically for the first time that DGT is effective and accurate for monitoring illicit drugs in wastewater and surface waters, and provides a powerful tool to investigating the presence, transport, and environmental behaviors of these drugs in the aquatic ecosystem.

  3. In-situ corrosion investigation at Masnedø CHP plant - a straw-fired power plant

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Karlsson, Asger

    1999-01-01

    Various austenitic and ferritic steels were exposed on a water-cooled probe in the superheater area of a straw-fired CHP plant. The temperature of the probe ranged from 450-600°C and the period of exposure was 1400 hours. The rate of corrosion was assessed based on unattacked metal remaining. The...... in depletion of chromium from the alloy. A clear trend was observed that selective corrosion increased with respect to the chromium content of the alloy.......Various austenitic and ferritic steels were exposed on a water-cooled probe in the superheater area of a straw-fired CHP plant. The temperature of the probe ranged from 450-600°C and the period of exposure was 1400 hours. The rate of corrosion was assessed based on unattacked metal remaining....... The corrosion products and course of corrosion for the various steel types were investigated using light optical and scanning electron microscopy. The ferritic steels suffered from corrosion mainly via material loss. The austenitic steels suffered from predominantly selective corrosion which resulted...

  4. Electron beam exposure mechanisms in hydrogen silsesquioxane investigated by vibrational spectroscopy and in-situ electron beam induced desorption

    Energy Technology Data Exchange (ETDEWEB)

    Olynick, D.L.; Cord, B.; Schipotinin, A.; Ogletree, D.F.; Schuck, P.J.

    2009-11-13

    Hydrogen Silsesquioxane (HSQ) is used as a high-resolution resist with resolution down below 10nm half-pitch. This material or materials with related functionalities could have widespread impact in nanolithography and nanoscience applications if the exposure mechanism was understood and instabilities controlled. Here we have directly investigated the exposure mechanism using vibrational spectroscopy (both Raman and Fourier transform Infrared) and electron beam desorption spectrocscopy (EBDS). In the non-networked HSQ system, silicon atoms sit at the corners of a cubic structure. Each silicon is bonded to a hydrogen atom and bridges 3 oxygen atoms (formula: HSiO3/2). For the first time, we have shown, via changes in the Si-H2 peak at ~;;2200 cm -1 in the Raman spectra and the release of SiHx products in EBID, that electron-bam exposed materials crosslinks via a redistribution reaction. In addition, we observe the release of significantly more H2 than SiH2 during EBID, which is indicative of additional reaction mechanisms. Additionally, we compare the behavior of HSQ in response to both thermal and electron-beam induced reactions.

  5. Raman and infrared studies of synthetic Maya Blue pigment

    Science.gov (United States)

    Reza, Layra; Manciu, Felicia; Ramirez, Alejandra; Chianelli, Russell

    2008-10-01

    A fascinating aspect of Maya pigments is that despite the environmentally harsh humidity and high temperatures they resist fading and they have unprecedented stability. In this investigation, we address the question of how organic dye binds to inorganic palygorskite to form a pigment similar to Maya Blue. We also address how such binding might be affected by varying the proportion of dye relative to that of the mineral, and by varying the length of heating time used in preparation of the pigment. Our analysis by Raman and infrared absorption spectroscopies proves the partial elimination of the selection rules for the centrosymmetric indigo, and shows the disappearance of the indigo N-H bonding, as the organic molecules incorporate into palygorskite material. Infrared data confirm the loss of zeolitic water and a partial removal of structural water after the heating process. Evidence of bonding between palygorskite and indigo through oxygen is revealed by both spectroscopic measurements.

  6. Availability and Utilization of Pigments from Microalgae.

    Science.gov (United States)

    Begum, Hasina; Yusoff, Fatimah Md; Banerjee, Sanjoy; Khatoon, Helena; Shariff, Mohamed

    2016-10-02

    Microalgae are the major photosynthesizers on earth and produce important pigments that include chlorophyll a, b and c, β-carotene, astaxanthin, xanthophylls, and phycobiliproteins. Presently, synthetic colorants are used in food, cosmetic, nutraceutical, and pharmaceutical industries. However, due to problems associated with the harmful effects of synthetic colorants, exploitation of microalgal pigments as a source of natural colors becomes an attractive option. There are various factors such as nutrient availability, salinity, pH, temperature, light wavelength, and light intensity that affect pigment production in microalgae. This paper reviews the availability and characteristics of microalgal pigments, factors affecting pigment production, and the application of pigments produced from microalgae. The potential of microalgal pigments as a source of natural colors is enormous as an alternative to synthetic coloring agents, which has limited applications due to regulatory practice for health reasons.

  7. The DYNAMO Orbiter Project: High Resolution Mapping of Gravity/Magnetic Fields and In Situ Investigation of Mars Atmospheric Escape

    Science.gov (United States)

    Smrekar, S.; Chassefiere, E.; Forget, F.; Reme, H.; Mazelle, C.; Blelly, P. -L.; Acuna, M.; Connerney, J.; Purucker, M.; Lin, R.

    2000-01-01

    Dynamo is a small Mars orbiter planned to be launched in 2005 or 2007, in the frame of the NASA/CNES Mars exploration program. It is aimed at improving gravity and magnetic field resolution, in order to better understand the magnetic, geologic and thermal history of Mars, and at characterizing current atmospheric escape, which is still poorly constrained. These objectives are achieved by using a low periapsis orbit, similar to the one used by the Mars Global Surveyor spacecraft during its aerobraking phases. The proposed periapsis altitude for Dynamo of 120-130 km, coupled with the global distribution of periapses to be obtained during one Martian year of operation, through about 5000 low passes, will produce a magnetic/gravity field data set with approximately five times the spatial resolution of MGS. Low periapsis provides a unique opportunity to investigate the chemical and dynamical properties of the deep ionosphere, thermosphere, and the interaction between the atmosphere and the solar wind, therefore atmospheric escape, which may have played a crucial role in removing atmosphere, and water, from the planet. There is much room for debate on the importance of current atmosphere escape processes in the evolution of the Martian atmosphere, as early "exotic" processes including hydrodynamic escape and impact erosion are traditionally invoked to explain the apparent sparse inventory of present-day volatiles. Yet, the combination of low surface gravity and the absence of a substantial internally generated magnetic field have undeniable effects on what we observe today. In addition to the current losses in the forms of Jeans and photochemical escape of neutrals, there are solar wind interaction-related erosion mechanisms because the upper atmosphere is directly exposed to the solar wind. The solar wind related loss rates, while now comparable to those of a modest comet, nonetheless occur continuously, with the intriguing possibility of important cumulative and

  8. Fungal Pigments: Deep into the Rainbow of Colorful Fungi.

    Science.gov (United States)

    Dufossé, Laurent; Caro, Yanis; Fouillaud, Mireille

    2017-08-07

    With the impact of globalization on research trends, the search for healthier life styles, the increasing public demand for natural, organic, and "clean labelled" products, as well as the growing global market for natural colorants in economically fast-growing countries all over the world, filamentous fungi started to be investigated as readily available sources of chemically diverse pigments and colorants.[...].

  9. Amylase activity of a yellow pigmented bacterium isolated from ...

    African Journals Online (AJOL)

    This study investigated the amylase activity of a yellow pigmented bacterium isolated from cassava wastes obtained from a dumpsite near a gari processing factory in Ibadan, Nigeria. Isolate was grown in nutrient broth containing 1% starch and then centrifuged at 5,000 rpm. Amylase activity was assayed using the DNSA ...

  10. Pigment signatures of phytoplankton composition in the northern ...

    African Journals Online (AJOL)

    Pigment indices were used to investigate the distribution and composition of phytoplankton in the northern Benguela during the austral spring of 2000, with sampling being conducted on five transect lines between 19°S and 25°S and at other inshore stations on the shelf. Total chlorophyll a concentrations (TChla) at the ...

  11. The interaction of light and microwaves with photosynthetic pigments

    NARCIS (Netherlands)

    Bent, van der S.J.

    1977-01-01

    In this Thesis the results of investigations on the lowest excited triplet state of photosynthetic pigments and some model compounds are presented, partly as reprints of published papers. Most of the experiments are carried out using ODMR ( O ptically D etected

  12. Dehydrogenation kinetics of pure and nickel-doped magnesium hydride investigated by in situ time-resolved powder X-ray diffraction

    DEFF Research Database (Denmark)

    Jensen, T.R.; Andreasen, A.; Vegge, Tejs

    2006-01-01

    The dehydrogenation kinetics of pure and nickel (Ni)-doped (2w/w%) magnesium hydride (MgH2) have been investigated by in situ time-resolved powder X-ray diffraction (PXD). Deactivated samples, i.e. air exposed, are investigated in order to focus on the effect of magnesium oxide (MgO) surface layers......, which might be unavoidable for magnesium (Mg)-based storage media for mobile applications. A curved position-sensitive detector covering 120 degrees in 20 and a rotating anode X-ray source provide a time resolution of 45 s and up to 90 powder pattems collected during an experiment under isothermal...... by the Johnson-Mehi-Avrami formalism in order to derive rate constants at different temperatures. The apparent activation energies for dehydrogenation of pure and Ni-doped magnesium hydride were E-A approximate to 300 and 250 kJ/mol, respectively. Differential scanning calorimetry gave, E-A = 270 k...

  13. Exploiting the Autofluorescent Properties of Photosynthetic Pigments for Analysis of Pigmentation and Morphology in Live Fremyella diplosiphon Cells

    Directory of Open Access Journals (Sweden)

    Juliana R. Bordowitz

    2010-07-01

    Full Text Available Fremyella diplosiphon is a freshwater, filamentous cyanobacterium that exhibits light-dependent regulation of photosynthetic pigment accumulation and cellular and filament morphologies in a well-known process known as complementary chromatic adaptation (CCA. One of the techniques used to investigate the molecular bases of distinct aspects of CCA is confocal laser scanning microscopy (CLSM. CLSM capitalizes on the autofluorescent properties of cyanobacterial phycobiliproteins and chlorophyll a. We employed CLSM to perform spectral scanning analyses of F. diplosiphon strains grown under distinct light conditions. We report optimized utilization of CLSM to elucidate the molecular basis of the photoregulation of pigment accumulation and morphological responses in F. diplosiphon.

  14. Photoinduced changes in photosystem II pigments

    Energy Technology Data Exchange (ETDEWEB)

    Andreeva, Atanaska S; Busheva, Mira C; Stoitchkova, Katerina V; Tzonova, Iren K, E-mail: katys@phys.uni-sofia.b

    2010-11-01

    The photosynthetic apparatus in higher plants performs two seemingly opposing tasks: efficient harvest of sunlight, but also rapid and harmless dissipation of excess light energy as heat to avoid deleterious photodamage. In order to study this process in pigment-protein supercomplexes of photosystem II (PSII), 77 K fluorescence and room temperature resonance Raman (RR) spectroscopy were applied to investigate the changes in structure and spectral properties of the pigments in spinach PSII membranes. The high-light treatment results in a strong quenching of the fluorescence (being largest when the excitation is absorbed by carotenoids) and a red-shift of the main maximum. Decomposition of the fluorescence spectra into four bands revealed intensive quenching of F685 and F695 bands, possible bleaching of chlorophyll a, enhanced extent of light harvesting complexes (LHCII) aggregation and increased energy transfer to aggregated LHCII. The analysis of RR spectra revealed the predominant contribution of ss-carotene (ss-Car) upon 457.8 and 488 nm excitations and lutein (Lut) at 514.5 nm. During prolonged exposure to strong light no significant bleaching of ss-Car and weak photobleaching of Lut is observed. The results will contribute to the efforts to produce more efficient and robust solar cells when exposed to fluctuations in light intensity.

  15. Enamel ultrastructure in pigmented hypomaturation amelogenesis imperfecta.

    Science.gov (United States)

    Wright, J T; Lord, V; Robinson, C; Shore, R

    1992-10-01

    Hypomaturation amelogenesis imperfecta (AI) is a hereditary condition of enamel that is presumed to result from defects during the maturation stage of enamel development. This study characterized the enamel ultrastructure and enamel crystallite morphology, as well as the distribution of organic material in enamel affected with pigmented hypomaturation AI. Enamel exhibiting autosomal recessive pigmented hypomaturation AI was sectioned or fractured and examined using light microscopy, scanning electron microscopy and transmission electron microscopy. Enamel samples were treated with 30% NaOCl or 8 M urea to remove organic components and determine the effect of deproteinization on crystallite morphology. These were compared with untreated normal enamel samples. The enamel crystallites in hypomaturation AI exhibited considerable variability in size and morphology. Examination of deproteinized tissue indicated that the AI crystallites had a thick coating, presumably of organic or partially mineralized material, which was not visible in normal enamel. The results of this investigation provide further evidence that hypomaturation AI is associated with the retention of organic material that is most probably enamel protein. Enamel protein retention is likely to be involved in the inhibition of normal crystallite growth resulting in the morphological crystallite abnormalities associated with this disorder.

  16. Epigenetic’s role in fish pigmentation

    Directory of Open Access Journals (Sweden)

    Laura Cal Delgado

    2014-04-01

    Full Text Available The agouti coat colour gene encodes a paracrine signalling molecule whose differential expression produces the characteristic dorsal-ventral pigment pattern observed in most mammals. We have recently demonstrated that this well-characterised mechanism from mammals also applies to fish with their much more complex pigment patterns. However, the developmental mechanism through which agouti acts to establish these colour differences remains unclear. The present study was undertaken to explore the molecular mechanisms that regulate agouti gene expression by in-vivo functional characterization of the agouti promoter and identification of possible putative regulatory elements that govern basal promoter activity. Specifically, the investigation was focused on the occurrence and role of CpG dinucleotides methylation in the agouti putative promoter sequence and on a possible epigenetic level of regulation of agouti expression. We report here expression analyses of eGFP expression from transgenic zebrafish containing an 8kb-agouti-Tol2-eGFP construct. eGFP expression was specifically found in the brain area and neural tube of Tol2 transposon vector transgenic embryos. Computer-based analysis revealed a putative CpG island immediately proximal to the translation start site. Global inhibition of methylation with 5-aza-2'-deoxycytidine promoted agouti production in association with decreasing CpG methylation. Taken together, these data identify a contributory role for DNA methylation in regulating agouti expression in zebrafish embryogenesis.

  17. Optimal methodologies for terahertz time-domain spectroscopic analysis of traditional pigments in powder form

    Science.gov (United States)

    Ha, Taewoo; Lee, Howon; Sim, Kyung Ik; Kim, Jonghyeon; Jo, Young Chan; Kim, Jae Hoon; Baek, Na Yeon; Kang, Dai-ill; Lee, Han Hyoung

    2017-05-01

    We have established optimal methods for terahertz time-domain spectroscopic analysis of highly absorbing pigments in powder form based on our investigation of representative traditional Chinese pigments, such as azurite [blue-based color pigment], Chinese vermilion [red-based color pigment], and arsenic yellow [yellow-based color pigment]. To accurately extract the optical constants in the terahertz region of 0.1 - 3 THz, we carried out transmission measurements in such a way that intense absorption peaks did not completely suppress the transmission level. This required preparation of pellet samples with optimized thicknesses and material densities. In some cases, mixing the pigments with polyethylene powder was required to minimize absorption due to certain peak features. The resulting distortion-free terahertz spectra of the investigated set of pigment species exhibited well-defined unique spectral fingerprints. Our study will be useful to future efforts to establish non-destructive analysis methods of traditional pigments, to construct their spectral databases, and to apply these tools to restoration of cultural heritage materials.

  18. Nanoscale Coloristic Pigments: Upper Limits on Releases from Pigmented Plastic during Environmental Aging, In Food Contact, and by Leaching

    DEFF Research Database (Denmark)

    Neubauer, Nicole; Scifo, Lorette; Navratilova, Jana

    2017-01-01

    The life cycle of nanoscale pigments in plastics may cause environmental or human exposure by various release scenarios. We investigated spontaneous and induced release with mechanical stress during/after simulated sunlight and rain degradation of polyethylene (PE) with organic and inorganic pigm...

  19. Ecological-friendly pigments from fungi.

    Science.gov (United States)

    Durán, Nelson; Teixeira, Maria F S; De Conti, Roseli; Esposito, Elisa

    2002-01-01

    The dyestuff industry is suffering from the increases in costs of feedstock and energy for dye synthesis, and they are under increasing pressure to minimize the damage to the environment. The industries are continuously looking for cheaper, more environmentally friendly routes to existing dyes. The aim of this minireview is to discuss the most important advances in the fungal pigment area and its interest in biotechnological applications. Characteristic pigments are produced by a wide variety of fungi and the chemical composition of natural dyes are described. These pigments exhibit several biological activities besides cytotoxicity. The synthetic pigments authorized by the EC and in USA and the natural pigments available in the world market are discussed. The obstacle to the exploitation of new natural pigments sources is the food legislation, requesting costly toxicological research, manufacturing costs, and acceptance by consumers. The dislike for novel ingredients is likely to be the biggest impediment for expansion of the pigment list in the near future. If the necessary toxicological testing and the comparison with accepted pigments are made, the fungal pigments, could be acceptable by the current consumer. The potentiality of pigment production in Brazil is possible due to tremendous Amazonian region biodiversity.

  20. Agglomeration Behavior of Non-Metallic Particles on the Surface of Ca-Treated High-Carbon Liquid Steel: An In Situ Investigation

    Directory of Open Access Journals (Sweden)

    Yasuhiro Tanaka

    2018-03-01

    Full Text Available The agglomeration behavior of non-metallic inclusion is a critical phenomenon that needs to be controlled as it has a direct relationship with the performance of produced steel. Although the agglomerates can be potential points for serious defects in every grade of steel, they are likely to be more serious in high-carbon steel due to the low ductility of these grades of steels as well as their usage in severe conditions. Confocal scanning laser microscopes (CSLM have been used by different researchers to investigate the agglomeration behavior of non-metallic particles at the interface of liquid steel and Ar gas, in situ. In recent decades, the agglomeration of Al2O3 particle in and on the surface of low-carbon steel has been widely investigated. However, there are very few studies focussing on non-Al2O3 inclusions which are included in a Ca-treated high-carbon steel. In this study, the agglomeration behaviors of sulfide/sulfide and sulfide/oxide particles on the surface of liquid high-carbon steel have been investigated in detail using CSLM. Agglomerations on the liquid surface are governed by capillary forces similar to the Al2O3 particle but this study demonstrates that agglomeration forces among non-Al2O3 particles on the surface of re-melted high-carbon samples are lower than pure-Al2O3 on the surface of low-carbon steel. Despite this, they show similar or longer acting lengths than pure-Al2O3.

  1. In-situ TEM investigation of microstructural evolution in magnetron sputtered Al-Zr and Al-Zr-Si coatings during heat treatment

    DEFF Research Database (Denmark)

    Gudla, Visweswara Chakravarthy; Rechendorff, Kristian; Balogh, Zoltan Imre

    2016-01-01

    The magnetron sputtered Al–Zr and Al–Zr–Si coatings were heat treated in-situ in a transmission electron microscope as well as ex-situ to observe their annealing behaviour and phase transformations. The samples were heated up to a temperature of 550 °C and then cooled to room temperature. A layered...... structure with alternating layers of Al and Zr/Si rich Al was found for the as deposited sputter coatings. During in-situ heat treatment, the phases formed in the coatings were analysed using selective area electron diffraction and energy dispersive Xrayspectroscopy. For the Al–Zr sputtered coatings...

  2. Design, fabrication and testing of an apparatus for in-situ investigation of free dendritic growth under an applied electric field

    Science.gov (United States)

    Nasresfahani, Mohamad Reza; Niroumand, Behzad; Kermanpur, Ahmad

    2015-04-01

    Modification of dendritic growth of primary phase during solidification has been a continuous quest for materials researchers during last decades. Use of electric current during solidification has been recently proposed as a suitable tool for refinement and modification of dendritic microstructures. Mechanisms by which an electric field could affect a dendritic morphology are not entirely clear as it is difficult to study the solidification phenomena during cooling. This paper reports the design, fabrication and testing of an instrument for in-situ study of the dendritic growth of transparent model materials in the presence of an applied electric field. The system consists of an isothermal bath, a growth chamber and an optical and imaging system. The structure of the growth chamber is designed to allow the growth of only a single dendrite under the applied electric field. In contrast to some previously made instruments which use two orthogonally placed cameras to take care of dendrite tilting or rotation errors, in this research a mathematical approach for calculating the actual dimensions and growth velocity of the dendrite using only one camera was suggested. This greatly simplifies the structure of the instrument. Solidification of a transparent model material, i.e. a succinonitrile alloy, was investigated as a case study under different applied electric fields using the instrument. The results of the study showed a reduction in the dendrite tip velocity in the presence of the electric field.

  3. Photocatalytic oxidation of the organic monolayers on TiO2 surface investigated by in-situ sum frequency generation spectroscopy

    Directory of Open Access Journals (Sweden)

    Yujin Tong

    2015-10-01

    Full Text Available In-situ vibrational sum frequency generation (SFG spectroscopy has been employed to investigate the photocatalytic oxidation of two types of well-ordered organic monolayers, namely, an arachidic acid (AA monolayer prepared by the Langmuir-Blodgett method and an octadecyltrichlorosilane (OTS monolayer prepared by the self-assembling method, on a TiO2 surface under ultraviolet (UV irradiation. The extremely high sensitivity and unique selectivity of the SFG spectroscopy enabled us to directly probe the structural changes in these monolayers during the surface photocatalytic oxidation and further elucidate their reaction mechanisms at a molecular level. It was revealed that the ordering of the monolayers during the photocatalytic reaction is strongly dependent on their interaction with the substrate; the AA monolayer maintains its ordered conformation until the final oxidation stage, while the OTS monolayer shows a large increase in disordering during the initial oxidation stage, indicating a different photocatalytic reaction mechanism of the two monolayers on the TiO2 surface.

  4. Photocatalytic oxidation of the organic monolayers on TiO{sub 2} surface investigated by in-situ sum frequency generation spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Yujin; Peng, Qiling; Ma, Tongsen; Nishida, Takuma; Ye, Shen, E-mail: ye@cat.hokudai.ac.jp [Catalysis Research Center, Hokkaido University, Sapporo 060-0811 (Japan)

    2015-10-01

    In-situ vibrational sum frequency generation (SFG) spectroscopy has been employed to investigate the photocatalytic oxidation of two types of well-ordered organic monolayers, namely, an arachidic acid (AA) monolayer prepared by the Langmuir-Blodgett method and an octadecyltrichlorosilane (OTS) monolayer prepared by the self-assembling method, on a TiO{sub 2} surface under ultraviolet (UV) irradiation. The extremely high sensitivity and unique selectivity of the SFG spectroscopy enabled us to directly probe the structural changes in these monolayers during the surface photocatalytic oxidation and further elucidate their reaction mechanisms at a molecular level. It was revealed that the ordering of the monolayers during the photocatalytic reaction is strongly dependent on their interaction with the substrate; the AA monolayer maintains its ordered conformation until the final oxidation stage, while the OTS monolayer shows a large increase in disordering during the initial oxidation stage, indicating a different photocatalytic reaction mechanism of the two monolayers on the TiO{sub 2} surface.

  5. An investigation into the effect of formulation variables and process parameters on characteristics of granules obtained by in situ fluidized hot melt granulation.

    Science.gov (United States)

    Mašić, Ivana; Ilić, Ilija; Dreu, Rok; Ibrić, Svetlana; Parojčić, Jelena; Durić, Zorica

    2012-02-28

    The aim of this study was to investigate the influence of binder content, binder particle size, granulation time and inlet air flow rate on granule size and size distribution, granule shape and flowability, as well as on drug release rate. Hydrophilic (polyethyleneglycol 2000) and hydrophobic meltable binder (glyceryl palmitostearate) were used for in situ fluidized hot melt granulation. Granule size was mainly influenced by binder particle size. Binder content was shown to be important for narrow size distribution and good flow properties. The results obtained indicate that conventional fluid bed granulator may be suitable for production of highly spherical agglomerates, particularly when immersion and layering is dominant agglomeration mechanism. Granule shape was affected by interplay of binder content, binder particle size and granulation time. Solid state analysis confirmed unaltered physical state of the granulate components and the absence of interactions between the active and excipients. Besides the nature and amount of binder, the mechanism of agglomerate formation seems to have an impact on drug dissolution rate. The results of the present study indicate that fluidized hot melt granulation is a promising powder agglomeration technique for spherical granules production. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Mineralogical In-situ Investigation of Acid-Sulfate Samples from the Rio Tinto River, Spain, with a Portable XRD/XRF Instrument

    Science.gov (United States)

    Sarrazin, P.; Ming, D. W.; Morris, R. V.; Fernandez-Remolar, D.; Amils, R.; Arvidson, R. E.; Blake, D.; Bish, D. L.

    2007-01-01

    A field campaign was organized in September 2006 by Centro de Astobiologica (Spain) and Washington University (St Louis, USA) for the geological study of the Rio Tinto river bed sediments using a suite of in-situ instruments comprising an ASD reflectance spectrometer, an emission spectrometer, panoramic and close-up color imaging cameras, a life detection system and NASA's CheMin 4 XRD/XRF prototype. The primary objectives of the field campaign were to study the geology of the site and test the potential of the instrument suite in an astrobiological investigation context for future Mars surface robotic missions. The results of the overall campaign will be presented elsewhere. This paper focuses on the results of the XRD/XRF instrument deployment. The specific objectives of the CheMin 4 prototype in Rio Tinto were to 1) characterize the mineralogy of efflorescent salts in their native environments; 2) analyze the mineralogy of salts and oxides from the modern environment to terraces formed earlier as part of the Rio Tinto evaporative system; and 3) map the transition from hematite-dominated terraces to the mixed goethite/salt-bearing terraces where biosignatures are best preserved.

  7. Investigation on the biosolubilization of brown coal using pyrolysis-gas chromatography-mass spectrometry and in situ-alkylation with tetraethylammonium hydroxide (TEAH)

    Energy Technology Data Exchange (ETDEWEB)

    Goetz, G.K.E. [RWTH Aachen (Germany). Lehrstuhl fuer Geologie, Geochemie und Lagerstaetten des Erdoels und der Kohle]|[Bonn Univ. (Germany). Inst. fuer Mikrobiologie und Biotechnologie; Frost, P.J.; Fakoussa, R.M. [Bonn Univ. (Germany). Inst. fuer Mikrobiologie und Biotechnologie

    1997-12-31

    Brown coal of the Lower Rhine basin has been used for the biosolubilization experiments using Lentimula edodes and Trametes versicolor. Studying the coal fractions and residues remaining after coal biosolubilization by pyrolysis-gas chromatography-mass spectromety using tetraethylammonium hydroxide (TEAH) at 610 C show significant alteration of coal`s organic matter. The assemblage of fatty acid esters released during the pyrolysis varies depending on the investigated coal fraction and the used fungi. Further, ethyl derivatives of aromatic ethers and acids as well as dicarbonic acid ethyl diesters gain an insight into the metabolism pathways of the biosolubilization process of brown coal. Therefore TEAH was used in these thermochemolysis experiments instead the more common tetramethylammonium hydroxide (TMAH). The reaction of TEAH with free hydroxyl and carboxyl groups yield the ethyl derivatives which can be easily identified and differentiated from their methyl homologues by mass spectrometry. In situ-alkylation with TEAH during thermochemolysis of native and biological altered geomacromolecules offers a differentiation between free hydroxyl groups and their methylated counterparts and substances, which are attached to humic substances via ester or ether bridges. (orig.)

  8. In situ visualization and quantitative investigation of the distribution of polycyclic aromatic hydrocarbons in the micro-zones of mangrove sediment.

    Science.gov (United States)

    Li, Ruilong; Zhu, Yaxian; Zhang, Yong

    2016-12-01

    The distribution of polycyclic aromatic hydrocarbons (PAHs) in the micro-zones of mangrove sediment is a predominant factors determining PAH bioavailability. In this study, a novel method for the in situ visualization (via microscope) and quantitative investigation of the PAH distribution in the micro-zones of mangrove sediment was established using microscopic fluorescence spectral analysis combined with derivative synchronous fluorescence spectroscopy (MFSA-DSFS). The MFSA-DSFS method significantly suppressed the background fluorescence signal of the sediment (the S/N values increased by over two orders of magnitude). The proportion of the nonpolar organic carbon content in the particulate organic matter (POM) rather than its content in the total organic matter (TOM) showed a significantly positive correlation with the uneven PAH distribution (Relative DC-M values) evaluated using the established method (p micro-zones of aged sediment was higher than that in the spiked sediment. Moreover, the distribution pattern of the PAHs within the mangrove sediment changed to become more homogeneous in the presence of low-molecular-weight organic acids (LMWOAs), which primarily contribute to increasing the POM content. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Hybrid perovskite solar cells: In situ investigation of solution-processed PbI2 reveals metastable precursors and a pathway to producing porous thin films

    KAUST Repository

    Barrit, Dounya

    2017-04-17

    The successful and widely used two-step process of producing the hybrid organic-inorganic perovskite CH3NH3PbI3, consists of converting a solution deposited PbI2 film by reacting it with CH3NH3I. Here, we investigate the solidification of PbI2 films from a DMF solution by performing in situ grazing incidence wide angle X-ray scattering (GIWAXS) measurements. The measurements reveal an elaborate sol–gel process involving three PbI2⋅DMF solvate complexes—including disordered and ordered ones—prior to PbI2 formation. The ordered solvates appear to be metastable as they transform into the PbI2 phase in air within minutes without annealing. Morphological analysis of air-dried and annealed films reveals that the air-dried PbI2 is substantially more porous when the coating process produces one of the intermediate solvates, making this more suitable for subsequent conversion into the perovskite phase. The observation of metastable solvates on the pathway to PbI2 formation open up new opportunities for influencing the two-step conversion of metal halides into efficient light harvesting or emitting perovskite semiconductors.

  10. Surface aggregation of urinary proteins and aspartic acid-rich peptides on the faces of calcium oxalate monohydrate investigated by in situ force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, M L; Qiu, S R; Hoyer, J R; Casey, W H; Nancollas, G H; De Yoreo, J J

    2008-05-28

    The growth of calcium oxalate monohydrate in the presence of Tamm-Horsfall protein (THP), osteopontin (OPN), and the 27-residue synthetic peptides (DDDS){sub 6}DDD and (DDDG){sub 6}DDD [where D = aspartic acid and X = S (serine) or G (glycine)] was investigated via in situ atomic force microscopy (AFM). The results show that these three growth modulators create extensive deposits on the crystal faces. Depending on the modulator and crystal face, these deposits can occur as discrete aggregates, filamentary structures, or uniform coatings. These proteinaceous films can lead to either the inhibition or increase of the step speeds (with respect to the impurity-free system) depending on a range of factors that include peptide or protein concentration, supersaturation and ionic strength. While THP and the linear peptides act, respectively, to exclusively increase and inhibit growth on the (-101) face, both exhibit dual functionality on the (010) face, inhibiting growth at low supersaturation or high modulator concentration and accelerating growth at high supersaturation or low modulator concentration. Based on analyses of growth morphologies and dependencies of step speeds on supersaturation and protein or peptide concentration, we argue for a picture of growth modulation that accounts for the observations in terms of the strength of binding to the surfaces and steps and the interplay of electrostatic and solvent-induced forces at crystal surface.

  11. Numerical Investigation of Influence of In-Situ Stress Ratio, Injection Rate and Fluid Viscosity on Hydraulic Fracture Propagation Using a Distinct Element Approach

    Directory of Open Access Journals (Sweden)

    Bo Zhang

    2016-02-01

    Full Text Available Numerical simulation is very useful for understanding the hydraulic fracturing mechanism. In this paper, we simulate the hydraulic fracturing using the distinct element approach, to investigate the effect of some critical parameters on hydraulic fracturing characteristics. The breakdown pressure obtained by the distinct element approach is consistent with the analytical solution. This indicates that the distinct element approach is feasible on modeling the hydraulic fracturing. We independently examine the influence of in-situ stress ratio, injection rate and fluid viscosity on hydraulic fracturing. We further emphasize the relationship between these three factors and their contributions to the hydraulic fracturing. With the increase of stress ratio, the fracture aperture increases almost linearly; with the increase of injection rate and fluid viscosity, the fracture aperture and breakdown pressure increase obviously. A low value of product of injection rate and fluid viscosity (i.e., Qμ will lead to narrow fracture aperture, low breakdown pressure, and complex or dispersional hydraulic fractures. A high value of Qμ would lead wide fracture aperture, high breakdown pressure, and simple hydraulic fractures (e.g., straight or wing shape. With low viscosity fluid, the hydraulic fracture geometry is not sensitive to stress ratio, and thus becomes a complex fracture network.

  12. In situ X-ray investigation of changing barrier growth temperatures on InGaN single quantum wells in metal-organic vapor phase epitaxy

    International Nuclear Information System (INIS)

    Ju, Guangxu; Honda, Yoshio; Tabuchi, Masao; Takeda, Yoshikazu; Amano, Hiroshi

    2014-01-01

    The effects of GaN quantum barriers with changing growth temperatures on the interfacial characteristics of GaN/InGaN single quantum well (SQW) grown on GaN templates by metalorganic vapour phase epitaxy were in situ investigated by X-ray crystal truncation rod (CTR) scattering and X-ray reflectivity measurements at growth temperature using a laboratory level X-ray diffractometer. Comparing the curve-fitting results of X-ray CTR scattering spectra obtained at growth temperature with that at room temperature, the In x Ga 1-x N with indium composition less than 0.11 was stabile of the indium distribution at the interface during the whole growth processes. By using several monolayers thickness GaN capping layer to protect the InGaN well layer within temperature-ramping process, the interfacial structure of the GaN/InGaN SQW was drastically improved on the basis of the curve-fitting results of X-ray CTR scattering spectra, and the narrow full width at half-maximum and strong luminous intensity were observed in room temperature photoluminescence spectra

  13. Ag nanoparticles agargel nanocomposites for SERS detection of cultural heritage interest pigments

    Science.gov (United States)

    Amato, F.; Micciche', C.; Cannas, M.; Gelardi, F. M.; Pignataro, B.; Li Vigni, M.; Agnello, S.

    2018-02-01

    Agarose gel (agargel) composites with commercial and laboratory made silver nanoparticles were prepared by a wet solution method at room temperature. The gel composites were used for pigment extraction and detection by Raman spectroscopy. Red (alizarin) and violet (crystal violet) pigments deposited on paper were extracted by the composites and were investigated by micro-Raman spectroscopy. Evaluation was carried out of the surface-enhanced Raman spectroscopy (SERS) effect induced by the silver nanoparticles embedded in the gel. A kinetic approach as a function of time was used to determine the efficiency of pigments extraction by composites deposition. A non-invasive extraction process of few minutes is demonstrated. This process induces active SERS for both used pigments. The reported results show the full exploitability of agargel silver nanoparticle composites for the extraction of pigments from paper based artworks.

  14. Optimal number of pigments in photosynthetic complexes

    International Nuclear Information System (INIS)

    Jesenko, Simon; Žnidarič, Marko

    2012-01-01

    We study excitation energy transfer in a simple model of a photosynthetic complex. The model, described by the Lindblad equation, consists of pigments interacting via dipole–dipole interaction. The overlapping of pigments induces an on-site energy disorder, providing a mechanism for blocking the excitation transfer. Based on the average efficiency as well as the robustness of random configurations of pigments, we calculate the optimal number of pigments that should be enclosed in a pigment–protein complex of a given size. The results suggest that a large fraction of pigment configurations are efficient as well as robust if the number of pigments is properly chosen. We compare the optimal results of the model to the structure of pigment–protein complexes as found in nature, finding good agreement. (paper)

  15. From metastable to stable modifications-in situ Laue diffraction investigation of diffusion processes during the phase transitions of (GeTe)(n)Sb2Te3 (6 < n < 15) crystals.

    OpenAIRE

    Schneider, Matthias N.; Biquard, Xavier; Stiewe, Christian; Schröder, Thorsten; Urban, Philipp; Oeckler, Oliver

    2012-01-01

    Temperature dependent phase transitions of compounds (GeTe)(n)Sb₂Te₃ (n = 6, 12, 15) have been investigated by in situ microfocus Laue diffraction. Diffusion processes involving cation defect ordering at similar to 300 degrees C lead to different nanostructures which are correlated to changes of the thermoelectric characteristics.

  16. The Genetic Basis of Pigmentation Differences Within and Between Drosophila Species.

    Science.gov (United States)

    Massey, J H; Wittkopp, P J

    2016-01-01

    In Drosophila, as well as in many other plants and animals, pigmentation is highly variable both within and between species. This variability, combined with powerful genetic and transgenic tools as well as knowledge of how pigment patterns are formed biochemically and developmentally, has made Drosophila pigmentation a premier system for investigating the genetic and molecular mechanisms responsible for phenotypic evolution. In this chapter, we review and synthesize findings from a rapidly growing body of case studies examining the genetic basis of pigmentation differences in the abdomen, thorax, wings, and pupal cases within and between Drosophila species. A core set of genes, including genes required for pigment synthesis (eg, yellow, ebony, tan, Dat) as well as developmental regulators of these genes (eg, bab1, bab2, omb, Dll, and wg), emerge as the primary sources of this variation, with most genes having been shown to contribute to pigmentation differences both within and between species. In cases where specific genetic changes contributing to pigmentation divergence were identified in these genes, the changes were always located in noncoding sequences and affected cis-regulatory activity. We conclude this chapter by discussing these and other lessons learned from evolutionary genetic studies of Drosophila pigmentation and identify topics we think should be the focus of future work with this model system. © 2016 Elsevier Inc. All rights reserved.

  17. A comprehensive study of eco-friendly natural pigment and its applications.

    Science.gov (United States)

    Parmar, Ramendra Singh; Singh, Charu

    2018-03-01

    Actinomycetes, a large group of filamentous bacteria account for 70-80% of secondary metabolites available commercially. The present investigation was undertaken with an aim to identify and characterize pigment from actinomycetes. Actinomycetes were isolated from rhizosphere soil samples collected from different regions of Madhya Pradesh state. Out of 85 actinomycetes, only 5 actinomycetes showed pigment production and based on diffusible pigment production ability one actinomycete ARITM02 was selected. The extraction of pigment was done by solvent extraction method using methanol and purified by TLC and column chromatography. The pigment was characterized by UV-Vis spectroscopy which showed the lamda maximum of 277.44. FTIR spectroscopy suggested various functional groups like amino group, amide group, hydroxide, benzene and lactone group. The Mass spectroscopy and NMR spectroscopy showed that the molecular mass of pigment is 621.7 and molecular formula is C34H43N3O8. The pigment was also tested for Antimicrobial activity against broad spectrum human pathogens, antioxidant test and toxicity test for safe use as a natural colorant in cosmetic, food, pharmaceutical and textile industries. The conclusion of study suggested that this novel pigment could be a versatile natural, safe and multipurpose.

  18. Enhanced production of pigments by addition of surfactants in submerged fermentation of Monascus purpureus H1102.

    Science.gov (United States)

    Wang, Yonghui; Zhang, Bobo; Lu, Liping; Huang, Yan; Xu, Ganrong

    2013-10-01

    The production of pigments by Monascus spp. has attracted increasing attention. Modification of the cell membrane structure by addition of surfactants has proved to be effective for the secretion of intracellular metabolites. Hence in this study the effects and underlying mechanism of surfactants on the production of pigments in submerged fermentation of Monascus purpureus H1102 were systematically investigated. Various surfactants exerted significant but different impacts on the biomass and production of pigments. The maximum production of pigment (304.3 U mL(-1) ) and highest extracellular/intracellular pigment ratio (1.46) were achieved when 15 g L(-1) Triton X-100 was added at 24 h of fermentation, corresponding to significant increases of 88.4 and 240% respectively compared with the control. Meanwhile, the concentration of citrinin (0.94 mg L(-1) ) was 20.6% lower than that of the control. A further study on the fatty acid composition of M. purpureus H1102 showed that the unsaturated/saturated fatty acid ratio and the index of unsaturated fatty acid increased significantly with the addition of Triton X-100. The addition of surfactant Triton X-100 could greatly enhance the production of pigment. It was suggested that Triton X-100 facilitated the secretion of intracellular pigment and therefore enhanced pigment production accordingly. © 2013 Society of Chemical Industry.

  19. Pigmented xerodermoid - Report of three cases

    OpenAIRE

    Das Jayanta Kumar; Gangopadhyay Asok Kumar

    2005-01-01

    Pigmented xerodermoid, a rare genodermatosis, presents with clinical features and pathology similar to xeroderma pigmentosum, but at a later age. DNA repair replication is normal, but there is total depression of DNA synthesis after exposure to UV radiation. Two siblings in their teens and a man in his thirties with features of pigmented xerodermoid, e.g. photophobia, freckle-like lesions, keratoses, dryness of skin, and hypo- and hyper-pigmentation, are described. Although classically the on...

  20. Production of Monascus-like azaphilone Pigment

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to the field of biotechnological production of polyketide based colorants from filamentous fungi, in particular a method for preparing a biomass comprising a Monascus-like pigment composition from a nontoxigenic and non-pathogenic fungal source. The present invention...... further relates to use of the Monascus-like pigment composition as a colouring agent for food items and/or non-food items, and a cosmetic composition comprising the Monascus-like pigment composition....

  1. PRODUCTION OF MONASCUS-LIKE AZAPHILONE PIGMENT

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to the field of biotechnological production of polyketide based colorants from filamentous fungi, in particular a method for preparing a biomass comprising a Monascus-like pigment composition from a nontoxigenic and non-pathogenic fungal source. The present invention...... further relates to use of the Monascus-like pigment composition as a colouring agent for food items and/or non-food items, and a cosmetic composition comprising the Monascus-like pigment composition....

  2. Investigation of the growth and in situ heating transmission electron microscopy analysis of Ag2S-catalyzed ZnS nanowires

    Science.gov (United States)

    Kim, Jung Han; Kim, Jong Gu; Song, Junghyun; Bae, Tae-Sung; Kim, Kyou-Hyun; Lee, Young-Seak; Pang, Yoonsoo; Oh, Kyu Hwan; Chung, Hee-Suk

    2018-04-01

    We investigated the semiconductor-catalyzed formation of semiconductor nanowires (NWs) - silver sulfide (Ag2S)-catalyzed zinc sulfide (ZnS) NWs - based on a vapor-liquid-solid (VLS) growth mechanism through metal-organic chemical vapor deposition (MOCVD) with a Ag thin film. The Ag2S-catalyzed ZnS NWs were confirmed to have a wurtzite structure with a width and length in the range of ∼30 nm to ∼80 nm and ∼1 μm, respectively. Using extensive transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS) analyses from plane and cross-sectional viewpoints, the ZnS NWs were determined to have a c-axis, [0001] growth direction. In addition, the catalyst at the top of the ZnS NWs was determined to consist of a Ag2S phase. To support the Ag2S-catalyzed growth of the ZnS NWs by a VLS reaction, an in situ heating TEM experiment was conducted from room temperature to 840 °C. During the experiment, the melting of the Ag2S catalyst in the direction of the ZnS NWs was first observed at approximately 480 °C along with the formation of a carbon (C) shell. Subsequently, the Ag2S catalyst melted completely into the ZnS NWs at approximately 825 °C. As the temperature further increased, the Ag2S and ZnS NWs continuously melted and vaporized up to 840 °C, leaving only the C shell behind. Finally, a possible growth mechanism was proposed based on the structural and chemical investigations.

  3. Electron crystallography of organic pigments

    Energy Technology Data Exchange (ETDEWEB)

    Boyce, G

    1997-10-01

    The principle aim of this thesis is the detailing of the development and subsequent use of electron crystallographic techniques which employ the maximum entropy approach. An account is given of the electron microscope as a crystallographic instrument, along with the necessary theory involved. Also, an overview of the development of electron crystallography, as a whole, is given. This progresses to a description of the maximum entropy methodology and how use can be made of electron diffraction data in ab initio phasing techniques. Details are also given of the utilisation of image derived phases in the determination of structural information. Extensive examples are given of the use of the maximum entropy program MICE, as applied to a variety of structural problems. A particular area of interest covered by this thesis is regarding the solid state structure of organic pigments. A detailed structure review of both {beta}-naphthol and acetoacetanilide pigments was undertaken. Information gained from this review was used as a starting point for the attempted structural elucidation of a related pigment, Barium Lake Red C. Details are given of the synthesis, electron microscope studies and subsequent ab initio phasing procedures applied in the determination of structural information on Barium Lake Red C. The final sections of this thesis detail electron crystallographic analyses of three quite different structures. Common to all was the use of maximum entropy methods, both for ab initio phasing and use of image derived phases. Overall, it is shown that electron crystallographic structure analyses using maximum entropy methods are successful using electron diffraction data and do provide distinct structural information even when significant perturbations to the data exist. (author)

  4. Design, development, and demonstration of a fully LabVIEW controlled in situ electrochemical Fourier transform infrared setup combined with a wall-jet electrode to investigate the electrochemical interface of nanoparticulate electrocatalysts under reaction conditions.

    Science.gov (United States)

    Nesselberger, Markus; Ashton, Sean J; Wiberg, Gustav K H; Arenz, Matthias

    2013-07-01

    We present a detailed description of the construction of an in situ electrochemical ATR-FTIR setup combined with a wall-jet electrode to investigate the electrocatalytic properties of nanoparticulate catalysts in situ under controlled mass transport conditions. The presented setup allows the electrochemical interface to be probed in combination with the simultaneous determination of reaction rates. At the same time, the high level of automation allows it to be used as a standard tool in electrocatalysis research. The performance of the setup was demonstrated by probing the oxygen reduction reaction on a platinum black catalyst in sulfuric electrolyte.

  5. Melanin pigmented solar absorbing surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Gallas, J.M.; Eisner, M.

    1980-01-01

    Selectivity enhancement is shown to result for melanin, a black biopolymer pigment, for sufficiently low sample density. The effect is proposed to follow from a consideration of the evanescent waves associated with the total internal reflection phenomenon. A relationship is discussed among powder density, pH and the paramagnetic properties of melanin; this relationship is shown to be consistent with, and offer support to an amino-acid side group proposed earlier as part of the melanin structure. A brief discussion is also presented on the optical properties of melanin and the relative importance of quinhydrone, a change transfer complex believed to exist in the polymeric structure of melanin.

  6. In situ

    Science.gov (United States)

    Chamlagain, Bhawani; Sugito, Tessa A; Deptula, Paulina; Edelmann, Minnamari; Kariluoto, Susanna; Varmanen, Pekka; Piironen, Vieno

    2018-01-01

    The in situ production of active vitamin B12 was investigated in aqueous cereal-based matrices with three strains of food-grade Propionibacterium freudenreichii . Matrices prepared from malted barley flour (33% w/v; BM), barley flour (6%; BF), and wheat aleurone (15%; AM) were fermented. The effect of cobalt and the lower ligand 5,6-dimethylbenzimidazole (DMBI) or its natural precursors (riboflavin and nicotinamide) on active B12 production was evaluated. Active B12 production was confirmed by UHPLC-UV-MS analysis. A B12 content of 12-37 μg·kg -1 was produced in BM; this content increased 10-fold with cobalt and reached 940-1,480 μg·kg -1 with both cobalt and DMBI. With riboflavin and nicotinamide, B12 production in cobalt-supplemented BM increased to 712 μg·kg -1 . Approximately, 10 μg·kg -1 was achieved in BF and AM and was increased to 80 μg·kg -1 in BF and 260 μg·kg -1 in AM with cobalt and DMBI. The UHPLC and microbiological assay (MBA) results agreed when both cobalt and DMBI or riboflavin and nicotinamide were supplemented. However, MBA gave ca. 20%-40% higher results in BM and AM supplemented with cobalt, indicating the presence of human inactive analogues, such as pseudovitamin B12. This study demonstrates that cereal products can be naturally fortified with active B12 to a nutritionally relevant level by fermenting with P. freudenreichii .

  7. Pigmented poroid neoplasm mimicking nodular melanoma.

    Science.gov (United States)

    Mitsuishi, Tsuyoshi; Ansai, Shin-ichi; Ueno, Takashi; Kawana, Seiji

    2010-06-01

    We reported the case of a 92-year-old woman with a pigmented and non-pigmented surface of the pedunculated nodule on her lower leg. Microscopic examination revealed that this nodule consisted of a component of small, dark, homogenous, poroid cells and cuticular cells in the dermis. The histopathological features of the lesion were consistent with poroid neoplasm. Immunohistochemistry showed that HMB-45 and Melan-A were positive in malanocytes and melanophages of the pigmented areas. Unlike most poroid neoplasms, this case showed pigmented lesion mimicked nodular melanoma.

  8. Clinicoepidemiological study of pigmented purpuric dermatoses

    Directory of Open Access Journals (Sweden)

    Lata Sharma

    2012-01-01

    Full Text Available Background: Pigmented purpuric dermatoses (PPD are a group of vascular disorders with varied manifestations which cause concern and are resistant to treatment. The literature is still lacking in clinicoepidemiological studies. Aim: To study the epidemiology, etiological, host and environmental factors, clinical manifestations, its variations, and the type prevalent in this part of the world. Materials and Methods: All cases of PPD were selected for the study from Skin and Venereal Disease, Out Patient Department between January 2008 and June 2009. Their history, examination, hematological investigations, and, in a few, histopathology findings were also recorded and data obtained were evaluated statistically. Results: There were 100 cases of PPD of total 55 323 patients (0.18%. There were 79 males and 21 females between 11 and 66 years. They were working as police men, security guards, barber, chemist, teachers, students, farmers, businessmen, and housewives. In a majority, there was a history of prolonged standing in day-to-day work. Purpuric, brownish pigmented, lichenoid or atrophic lesions were seen depending upon the type of PPD on lower parts of one or both lower limbs. Blood investigations were normal. Schamberg′s disease was seen in ninety five, Lichen aureus in three, lichenoid dermatosis and Majocchi′s disease in one case each. Discussion: Three clinical types of PPD were diagnosed which may represent different features of the same disease. Cell-mediated immunity, immune complexes, capillary fragility, gravitational forces, venous hypertension, focal infection, clothing, contact allergy to dyes, and drug intake have been incriminating factors in the past. Patient′s occupation and environmental factors may also be considered contributory in precipitating the disease. Conclusions: The study revealed the problem of PPD in this geographical area, its magnitude, clinical presentation, the type prevalent, and possible aggravating

  9. The biogeochemistry of tetrapyrrole pigments, emphasizing chlorophyll

    Energy Technology Data Exchange (ETDEWEB)

    Louda, J.W.

    1993-01-01

    Electronic absorption spectra recorded on native geopigments and on in vitro derivatives, obtained with combinations of copper insertion and borohydride reduction reactions, allowed a sensitive chromophore identification' scheme to be developed. Quantitation of the Ni and VO geoporphyrins, as well as the benzo-forms of each, was tested and precisions at the level of 100 [+-] 5% found. An overall methodology for obtaining repeatable low-voltage mass spectra on geoporphyrin arrays is presented. Repeatabilities for the various mass spectral-derived indices were; %DPEP ([+-]2%), X ([+-]2%), A.I.([+-]5%) and % BENZ ([+-]10%). Quantitation of the metallobenzoporphyrins was much better ([+-]2%) with UV/VIS techniques. Tetrapyrrole geochemistry was investigated at all stages of organic evolution. Thus, viable and senescent/dead uni-algal cultures, sediment trap material, surface (<1m) sediments, deep ocean long cores (DSDP), oil shales and petroleum crudes were investigated. Results indicate that the chlorophylls can serve as sources for a variety of geoporphyrins. Early in diagenesis two competing reactions dictate further fossilization.' First is the loss of the carbomethoxy group. This produces pyropheophorbides which can either lead to the true DPEP series, via a sequence of defunctionaliation reactions or, via intramolecular cyclization (dehydration), to certain 13[sup 2], 17[sup 3]-cyclopheophorbide enols. The latter, following defunctionalization, give rise to DiDPEP and/or DPEP-type pigments with a 7-membered exocyclic ring. Second, chlorophyll nuclei which have undergone oxidative scission of the isocyclic ring can, through purpurins and chlorins, theoretically yield C28-C30 ETIO-series porphyrins. Bacteriochlorophyll-a was found to be a dominant pigment in several anoxic sediments and is suggested as an important and highly specific precursor for certain geoporphyrins (i.e 3-methyl-desethyl-DPEP).

  10. Looking for Common Fingerprints in Leonardo's Pupils Using Nondestructive Pigment Characterization.

    Science.gov (United States)

    Bonizzoni, Letizia; Gargano, Marco; Ludwig, Nicola; Martini, Marco; Galli, Anna

    2017-08-01

    Non-invasive, portable analytical techniques are becoming increasingly widespread for the study and conservation in the field of cultural heritage, proving that a good data handling, supported by a deep knowledge of the techniques themselves, and the right synergy can give surprisingly substantial results when using portable but reliable instrumentation. In this work, pigment characterization was carried out on 21 Leonardesque paintings applying in situ X-ray fluorescence (XRF) and fiber optic reflection spectroscopy (FORS) analyses. In-depth data evaluation allowed to get information on the color palette and the painting technique of the different artists and workshops . Particular attention was paid to green pigments (for which a deeper study of possible pigments and alterations was performed with FORS analyses), flesh tones (for which a comparison with available data from cross-sections was made), and ground preparation.

  11. Silver Accumulation in the Green Microalga Coccomyxa actinabiotis: Toxicity, in Situ Speciation, and Localization Investigated Using Synchrotron XAS, XRD, and TEM.

    Science.gov (United States)

    Leonardo, Thomas; Farhi, Emmanuel; Pouget, Stéphanie; Motellier, Sylvie; Boisson, Anne-Marie; Banerjee, Dipanjan; Rébeillé, Fabrice; den Auwer, Christophe; Rivasseau, Corinne

    2016-01-05

    Microalgae are good candidates for toxic metal remediation biotechnologies. This study explores the cellular processes implemented by the green microalga Coccomyxa actinabiotis to take up and cope with silver over the concentration range of 10(-7) to 10(-2) M Ag(+). Understanding these processes enables us to assess the potential of this microalga for applications for bioremediation. Silver in situ speciation and localization were investigated using X-ray absorption spectroscopy, X-ray diffraction, and transmission electron microscopy. Silver toxicity was evaluated by monitoring microalgal growth and photochemical parameters. Different accumulation mechanisms were brought out depending on silver concentration. At low micromolar concentration, microalgae fixed all silver initially present in solution, trapping it inside the cells into the cytosol, mainly as unreduced Ag(I) bound with molecules containing sulfur. Silver was efficiently detoxified. When concentration increased, silver spread throughout the cell and particularly entered the chloroplast, where it damaged the photosystem. Most silver was reduced to Ag(0) and aggregated to form crystalline silver nanoparticles of face-centered cubic structure with a mean size of 10 nm. An additional minor interaction of silver with molecules containing sulfur indicated the concomitant existence of the mechanism observed at low concentration or nanoparticle capping. Nanoparticles were observed in chloroplasts, in mitochondria, on the plasma membrane, on cytosolic membrane structures, and in vacuoles. Above 10(-4) M Ag(+), damages were irreversible, and photosynthesis and growth were definitely inhibited. However, high silver amounts remained confined inside microalgae, showing their potential for the bioremediation of contaminated water.

  12. Potential of EPR spin-trapping to investigate in situ free radicals generation from skin allergens in reconstructed human epidermis: cumene hydroperoxide as proof of concept.

    Science.gov (United States)

    Kuresepi, Salen; Vileno, Bertrand; Turek, Philippe; Lepoittevin, Jean-Pierre; Giménez-Arnau, Elena

    2018-02-01

    The first step in the development of skin sensitisation to a chemical, and in the elicitation of further allergic contact dermatitis (ACD), is the binding of the allergen to skin proteins after penetrating into the epidermis. The so-formed antigenic adduct is then recognised by the immune system as foreign to the body. Sensitising organic hydroperoxides derived from autoxidation of natural terpenes are believed to form antigens through radical-mediated mechanisms, although this has not yet been established. So far, in vitro investigations on reactive radical intermediates derived from these skin sensitisers have been conducted in solution, yet with experimental conditions being far away from real-life sensitisation. Herein, we report for the first time, the potential use of EPR spin-trapping to study the in situ generation of free radicals derived from cumene hydroperoxide CumOOH in a 3D reconstructed human epidermis (RHE) model, thus much closer to what may happen in vivo. Among the undesirable effects associated with dermal exposure to CumOOH, it is described to cause allergic and irritant dermatitis, being reported as a significant sensitiser. We considered exploiting the usage of spin-trap DEPMPO as an extensive view of all sort of radicals derived from CumOOH were observed all at once in solution. We showed that in the Episkin TM RHE model, both by incubating in the assay medium and by topical application, carbon radicals are mainly formed by redox reactions suggesting the key role of CumOOH-derived carbon radicals in the antigen formation process.

  13. Physico-chemical changes in dissolved organic matters in the rhizosphere of plants grown in soil amended with organic wastes: an in-situ investigation.

    Science.gov (United States)

    Djae, Tanalou; Bravin, Matthieu; Garnier, Cédric; Mayen, Jean-Fabien; Doelsch, Emmanuel

    2014-05-01

    In agricultural context, prerequisite condition to forecast trace metal phytodisponibility is to evaluate trace metal speciation in the rhizosphere solution, especially in soil amended with organic wastes. The most advanced trace metal speciation models (e.g. WHAM, NICA-DONNAN) take into account dissolved organic matter (DOM) reactivity toward trace metals. Generally, the scientific community uses, a fixed percentage of DOM reactivity, usually of 40 % to 80 %, to predict trace metal speciation. However, recent studies have demonstrated that the binding capacity of DOM towards trace metals is much larger than expected. The aim of our study was to investigate the mechanisms supporting the variability in DOM reactivity by assessing the physico-chemical changes of DOM in the bulk-soil and rhizosphere in context of agricultural recycling of organic wastes. An in-situ experiment was conducted in Reunion Island (Indian Ocean). Two plant species, i.e. a graminaceous species the fescue (Festuca rubra) and a dicotyledonous species the tomato (Lycopersicon esculentum), were grown on a soil where we applied two types of organic wastes (pig manure compost and poultry manure compost) at three rates and a mineral fertilizer. Following this experiment, the soil either adhering to the roots (i.e. rhizosphere) or not (i.e. bulk-soil) was sampled and the soil solution was recovered by chemical extraction. DOM concentration, total acidity and DOM fluorescence were measured. Root activities and organic wastes induced variations in the physico-chemical parameters of DOM. DOM concentration tended to increase in bulk-soil with increasing organic waste application rate. DOM concentrations measured in rhizosphere are significantly greater than those in the bulk-soil especially when organic wastes were applied to soil. Preliminary results allow us to observe a decrease in the density of carboxylic-like (pKa

  14. Performance evaluation of a miniature laser ablation time-of-flight mass spectrometer designed for in situ investigations in planetary space research.

    Science.gov (United States)

    Riedo, A; Bieler, A; Neuland, M; Tulej, M; Wurz, P

    2013-01-01

    Key performance features of a miniature laser ablation time-of-flight mass spectrometer designed for in situ investigations of the chemical composition of planetary surfaces are presented. This mass spectrometer is well suited for elemental and isotopic analysis of raw solid materials with high sensitivity and high spatial resolution. In this study, ultraviolet laser radiation with irradiances suitable for ablation (laser ablation studies at infrared wavelengths, several improvements to the experimental setup have been made, which allow accurate control over the experimental conditions and good reproducibility of measurements. Current performance evaluations indicate significant improvements to several instrumental figures of merit. Calibration of the mass scale is performed within a mass accuracy (Δm/m) in the range of 100 ppm, and a typical mass resolution (m/Δm) ~600 is achieved at the lead mass peaks. At lower laser irradiances, the mass resolution is better, about (m/Δm) ~900 for lead, and limited by the laser pulse duration of 3 ns. The effective dynamic range of the instrument was enhanced from about 6 decades determined in previous study up to more than 8 decades at present. Current studies show high sensitivity in detection of both metallic and non-metallic elements. Their abundance down to tens of ppb can be measured together with their isotopic patterns. Due to strict control of the experimental parameters, e.g. laser characteristics, ion-optical parameters and sample position, by computer control, measurements can be performed with high reproducibility. Copyright © 2012 John Wiley & Sons, Ltd.

  15. Deformation behavior of Mg-8.5wt.%Al alloy under reverse loading investigated by in-situ neutron diffraction and elastic viscoplastic self-consistent modeling

    International Nuclear Information System (INIS)

    Wang, H.; Lee, S.Y.; Gharghouri, M.A.; Wu, P.D.; Yoon, S.G.

    2016-01-01

    The EVPSC-TDT model for polycrystal plasticity and in-situ neutron diffraction have been used to investigate the behavior of a Mg-8.5wt.%Al alloy with two starting textures: 1) a typical extrusion texture in which a majority of the grains are oriented favorably for extension twinning via compression perpendicular to the basal pole, and 2) a modified texture in which extension twinning can be activated via tension parallel to the basal pole in a majority of the grains. Using a small number of adjustable parameters, and only two macroscopic tensile stress–strain curves for calibration, the model is able to capture, quantitatively, the trends in multiple data sets, including grain-level elastic lattice strains, and diffraction peak intensity changes due to lattice re-orientation associated with twinning. For twinning, the model assumes a polar critical resolved shear stress activation criterion and assigns the stress and hardening of the parent crystal to a newly formed twin. The model allows twinning to be driven either by the stress in the parent crystal (matrix reduction), in which case all of the twin transformation strain is assigned to the matrix, or by the stress in the twin (twin propagation), in which case all of the twin transformation strain is assigned to the twin. A detailed comparison between the model predictions and the neutron diffraction data reveals that assigning all of the twin transformation strain either to the matrix or to the twin is too one-sided, leading to excessive relaxation and hardening effects. A more equitable partitioning of the twin transformation strain is necessary. It is suggested that the stress and hardening assigned to a newly formed twin is of less importance to the performance of the model than the partitioning of the twin transformation strain.

  16. Color stability of thermochromic pigment in maxillofacial silicone

    Science.gov (United States)

    Lassila, Lippo V.J.; Tolvanen, Mimmi; Valittu, Pekka K.

    2013-01-01

    PURPOSE Maxillofacial silicone elastomer is usually colored intrinsically with color pigments to match skin colors. The purpose of this study was to investigate the color stability of a maxillofacial silicone elastomer, colored with a thermochromic, color changing pigment. MATERIALS AND METHODS Disc-shaped maxillofacial silicone specimens were prepared and divided into 3 groups: a conventionally colored control group, one group additionally colored with 0.2 wt% thermochromic pigment , and one group with 0.6 wt% thermochromic pigment. Half of the surface of each specimen was covered with an aluminium foil. All of the specimens were exposed to UV radiation in 6 hour cycles over 46 days. In between the UV exposures, half of the specimens were stored in darkness, at room temperature, and the other half was stored in an incubator, at a humidity of 97% and a temperature of +37℃. Color measurements were made with a spectrophotometer and registered according to the CIELAB L*a*b* color model system. The changes in L*, a* and b* values during artificial aging were statistically analyzed by using paired samples t-test and repeated measures ANOVA. P-values maxillofacial prostheses. PMID:23755330

  17. Effects of blue light on pigment biosynthesis of Monascus.

    Science.gov (United States)

    Chen, Di; Xue, Chunmao; Chen, Mianhua; Wu, Shufen; Li, Zhenjing; Wang, Changlu

    2016-04-01

    The influence of different illumination levels of blue light on the growth and intracellular pigment yields of Monascus strain M9 was investigated. Compared with darkness, constant exposure to blue light of 100 lux reduced the yields of six pigments, namely, rubropunctatamine (RUM), monascorubramine (MOM), rubropunctatin (RUN), monascorubrin (MON), monascin (MS), and ankaflavin (AK). However, exposure to varying levels of blue light had different effects on pigment production. Exposure to 100 lux of blue light once for 30 min/day and to 100 lux of blue light once and twice for 15 min/day could enhance RUM, MOM, MS, and AK production and reduce RUN and MON compared with non-exposure. Exposure to 100 lux twice for 30 min/day and to 200 lux once for 45 min/day decreased the RUM, MOM, MS, and AK yields and increased the RUN and MON. Meanwhile, the expression levels of pigment biosynthetic genes were analyzed by real-time quantitative PCR. Results indicated that gene MpPKS5, mppR1, mppA, mppB, mmpC, mppD, MpFasA, MpFasB, and mppF were positively correlated with the yields of RUN and MON, whereas mppE and mppR2 were associated with RUM, MOM, MS, and AK production.

  18. Radiation degradation of molasses pigment. 2. Molecular weight fraction

    International Nuclear Information System (INIS)

    Sawai, Teruko; Sekiguchi, Masayuki; Tanabe, Hiroko

    1996-01-01

    Water demand in Tokyo has increased rapidly. Because of the scarcity of water sources within the city, Tokyo is dependent on water from other prefectures. Recycling of municipal effluent is an effective means of coping with water shortage in Tokyo. We have studied the radiation treatment of waste water for recycling. The degradation of molasses pigments in waste water from yeast factory by radiation was investigated. The dialyzed molasses pigments and non-dialyzed samples in waste waters were compared in chromaticity, UV absorption, color different and COD. The dialysis and fractionation by permeable membrane were carried out with Seamless Cellulose tubing (Union Carbide Corporation) and spectra/Por membrane (Spectrum Medical Industries INC.) The TOC values decreased and the dark brown color faded with increasing dose. The high molecular weight components of molasses pigment were degraded to lower molecular weight substances and decomposed to carbon dioxide. The relationships between the value of chromaticity/TOC and molecular weight of molasses pigments were obtained by radiation. (author)

  19. Gene regulation networks generate diverse pigmentation patterns in plants.

    Science.gov (United States)

    Albert, Nick W; Davies, Kevin M; Schwinn, Kathy E

    2014-01-01

    The diversity of pigmentation patterns observed in plants occurs due to the spatial distribution and accumulation of colored compounds, which may also be associated with structural changes to the tissue. Anthocyanins are flavonoids that provide red/purple/blue coloration to plants, often forming complex patterns such as spots, stripes, and vein-associated pigmentation, particularly in flowers. These patterns are determined by the activity of MYB-bHLH-WDR (MBW) transcription factor complexes, which activate the anthocyanin biosynthesis genes, resulting in anthocyanin pigment accumulation. Recently, we established that the MBW complex controlling anthocyanin synthesis acts within a gene regulation network that is conserved within at least the Eudicots. This network involves hierarchy, reinforcement, and feedback mechanisms that allow for stringent and responsive regulation of the anthocyanin biosynthesis genes. The gene network and mobile nature of the WDR and R3-MYB proteins provide exciting new opportunities to explore the basis of pigmentation patterning, and to investigate the evolutionary history of the MBW components in land plants.

  20. Changing oxidoreduction potential to improve water-soluble yellow pigment production with Monascus ruber CGMCC 10910.

    Science.gov (United States)

    Huang, Tao; Tan, Hailing; Lu, Fangju; Chen, Gong; Wu, Zhenqiang

    2017-11-21

    Monascus pigments are widely used in the food and pharmaceutical industries due to their safety to human health. Our previous study found that glucose concentration induced extracellular oxidoreduction potential (ORP) changes could influence extracellular water-soluble yellow pigment production by Monascus ruber CGMCC 10910 in submerged fermentation. In this study, H 2 O 2 and dithiothreitol (DTT) were used to change the oxidoreduction potential for investigating the effects of oxidative or reductive substances on Monascus yellow pigment production by Monascus ruber CGMCC 10910. The extracellular ORP could be controlled by H 2 O 2 and DTT. Both cell growth and extracellular water-soluble yellow pigment production were enhanced under H 2 O 2 -induced oxidative (HIO) conditions and were inhibited under dithiothreitol-induced reductive conditions. By optimizing the amount of H 2 O 2 added and the timing of the addition, the yield of extracellular water-soluble yellow pigments significantly increased and reached a maximum of 209 AU, when 10 mM H 2 O 2 was added on the 3rd day of fermentation with M. ruber CGMCC 10910. Under HIO conditions, the ratio of NADH/NAD+ was much lower than that in the control group, and the expression levels of relative pigment biosynthesis genes were up-regulated; moreover, the activity of glucose-6-phosphate dehydrogenase (G6PDH) was increased while 6-phosphofructokinase (PFK) activity was inhibited. Oxidative conditions induced by H 2 O 2 increased water-soluble yellow pigment accumulation via up-regulation of the expression levels of relative genes and by increasing the precursors of pigment biosynthesis through redirection of metabolic flux. In contrast, reductive conditions induced by dithiothreitol inhibited yellow pigment accumulation. This experiment provides a potential strategy for improving the production of Monascus yellow pigments.

  1. The bioefficacy of microemulsified natural pigments in egg yolk pigmentation.

    Science.gov (United States)

    Chow, P Y; Gue, S Z; Leow, S K; Goh, L B

    2014-01-01

    1. This study was designed to test the hypothesis that microemulsified carotenoid products show improved bioavailability over corresponding regular preparations, leading to greater yolk pigmentation at lower dosages. 2. The first trial was conducted using a maize-soya bean basal diet supplemented with either 0.25, 0.5, 0.75, 1.0 and 1.25 g/kg of microemulsified Red or non-microemulsified Red. The second trial involved feeding microemulsified Yellow or non-microemulsified Yellow using a similar dosage range. The layers were divided into 4 replicates of 8 layers each (32 layers per treatment). The 8 cages of layers were fed from a single feed trough. Feed and water were provided ad libitum throughout the trial. Each week, the eggs were collected. The whole liquid egg colour was determined by means of a commercially available yolk colour fan. Where required, HPLC-(high-performance liquid chromatography) based analysis of trans-capsanthin or trans-lutein equivalents using the Association of Analytical Communities method was carried out. Data were statistically analysed by one-way ANOVA method using Statgraphics. 3. Results showed that the colour and carotenoid content of the egg yolk increased with increasing amount of carotenoids in the diet. The colour of egg yolks from layers fed similar concentrations of microemulsified versus the regular preparation was significantly different. At the commercial recommended dose of one g/kg regular Yellow or Red product, the microemulsified pigmenter is able to provide the equivalent yolk colour at a 20-30% lower dose. 4. In conclusion, the trial results supported the hypothesis that a desired yolk colour score is achievable at a significantly lower inclusion rate when carotenoid molecules are emulsified using the microemulsion nanotechnology.

  2. Thin Layer Chromatography (TLC) of Chlorophyll Pigments.

    Science.gov (United States)

    Foote, Jerry

    1984-01-01

    Background information, list of materials needed, procedures used, and discussion of typical results are provided for an experiment on the thin layer chromatography of chlorophyll pigments. The experiment works well in high school, since the chemicals used are the same as those used in paper chromatography of plant pigments. (JN)

  3. 21 CFR 178.3725 - Pigment dispersants.

    Science.gov (United States)

    2010-04-01

    ... HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADJUVANTS, PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants and Production Aids § 178.3725 Pigment dispersants. Subject to the provisions of this... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Pigment dispersants. 178.3725 Section 178.3725 Food...

  4. Quantifying Abdominal Pigmentation in Drosophila melanogaster.

    Science.gov (United States)

    Saleh Ziabari, Omid; Shingleton, Alexander W

    2017-06-01

    Pigmentation is a morphologically simple but highly variable trait that often has adaptive significance. It has served extensively as a model for understanding the development and evolution of morphological phenotypes. Abdominal pigmentation in Drosophila melanogaster has been particularly useful, allowing researchers to identify the loci that underlie inter- and intraspecific variations in morphology. Hitherto, however, D. melanogaster abdominal pigmentation has been largely assayed qualitatively, through scoring, rather than quantitatively, which limits the forms of statistical analysis that can be applied to pigmentation data. This work describes a new methodology that allows for the quantification of various aspects of the abdominal pigmentation pattern of adult D. melanogaster. The protocol includes specimen mounting, image capture, data extraction, and analysis. All the software used for image capture and analysis feature macros written for open-source image analysis. The advantage of this approach is the ability to precisely measure pigmentation traits using a methodology that is highly reproducible across different imaging systems. While the technique has been used to measure variation in the tergal pigmentation patterns of adult D. melanogaster, the methodology is flexible and broadly applicable to pigmentation patterns in myriad different organisms.

  5. Pigmented skin disorders: Evaluation and treatment

    NARCIS (Netherlands)

    Kroon, M.W.

    2015-01-01

    Pigmentary disorders are disturbances of human skin color. Minor changes in the cellular physiology of the skin can dramatically affect pigment production in positive or negative manner. In this these, associated diseases, therapeutical options and disease parameters for the pigmentation disorder

  6. Investigating phase behavior and structural changes in NiO/Ni-YSZ composite with monochromatic in-situ 2D and static 3D neutron imaging

    DEFF Research Database (Denmark)

    Makowska, Malgorzata G.; Strobl, Markus; Kardjilov, Nikolay

    2017-01-01

    In this work, we report neutron imaging studies of redox cycling of NiO/Ni-8YSZ (nickel/nickel oxide – yttria stabilized zirconia) composite used for electrodes in solid oxide electrochemical cells for efficient energy conversion (power-to-gas and vice versa) purposes (i.e. for anodes in solid...... source SINQ of Paul Scherrer Institut (PSI, Switzerland) by means of monochromatic neutron imaging, and post mortem monochromatic neutron tomography was performed at Helmholtz Zentrum Berlin (HZB) at the BER II reactor using the CONRAD-2 imaging instrument. Combining both time resolved radiography...... oxide fuel cells, and for cathodes in solid oxide electrolysis cells). Results of in-situ 2D and ex-situ 3D measurements are presented. In-situ observation of phase transition between NiO and Ni were performed at the test Beamline for neutron Optics and other Applications (BOA) at the continuous neutron...

  7. In-situ spectroscopic investigations of the redox behavior of poly(indole-5-carboxylic-acid) modified electrodes in acidic aqueous solutions.

    Science.gov (United States)

    Talbi, H; Billaud, D; Louarn, G; Pron, A

    2001-03-01

    The oxidation of electrochemically grown poly(indole-5-carboxylic-acid) (P5CO2H) and its spectroscopic properties have been studied by in-situ spectroelectrochemical techniques. The purpose of this paper is to characterize the different modifications on the P5CO2H backbone, induced by the electrochemical oxidation in aqueous acidic solution. We have identified, on the basis of Raman spectra, the vibrational modes associated with neutral and oxidized segments of polymer. It was shown that at least three chemically and optically different species (perhaps other products too) are produced in different potential regimes upon oxidation of this polymer. The results obtained also indicate that the molecular properties of this conducting polymer are better revealed by in-situ resonant spectra than by ex-situ infrared and Raman studies.

  8. Grimsel test site investigation Phase IV. The Nagra-JAEA in situ study of safety relevant radionuclide retardation in fractured crystalline rock. III: The RRP project final report

    International Nuclear Information System (INIS)

    Alexander, W. R.; Frieg, B.; Ota, K.

    2009-11-01

    possible under conditions closely resembling the final experiment. The EP began in 1990 with the Phase I feasibility study and continued in Phase II with an extensive campaign of laboratory and field tests between 1994 and 1996. This final report provides a summary of the Phase II work, which included: a) Injection of four different radionuclide cocktails into the EP test zone that was established in the AU96 experimental shear zone (MI shear zone) at the GTS; b) Continuous monitoring of radiotracer breakthrough at the outlet borehole followed by stabilisation of the rock volume containing the retarded radionuclides by in situ resin impregnation; c) Excavation of the stabilised rock volume by shear zone-parallel overcoring for sample recovery and laboratory investigations; d) Radiochemical analysis on solid shear zone samples and detailed structural geological investigation of the flow-path geometry within the dipole. One of the aims of EP was to examine the behaviour of performance assessment (PA) relevant radionuclides and so those nuclides selected for consideration in Nagra's Kristallin-l PA and JAEA's TRU-I PA were examined. The final selection considered the nuclides 238 U, 235 U, 234 U, 237 Np and 99 Tc because they are safety relevant; 152 Eu is considered to be a good chemical analogue for other lanthanides and trivalent actinides; 60 Co is a good chemical analogue for the safety relevant 59 Ni and easier to obtain and simpler to analyse than 59 Ni; 75 Se is a complete chemical analogue of the safety relevant 79 Se, but with a much shorter half-life (120 days against 65 ka); 113 Sn is a complete chemical analogue of the safety relevant 126 Sn, but with a much shorter half-life (115 days against 100 ka); and finally the stable Mo is a complete chemical analogue of the safety relevant 93 Mo (half-life of 3.5 ka). Scoping calculations indicated that the low natural solubilities of these radionuclides in the Grimsel groundwater/rock system meant that the likely

  9. Bilateral pigmented villonodular synovitis of the knee

    Directory of Open Access Journals (Sweden)

    Samir H. Shah

    2015-12-01

    Full Text Available Pigmented villonodular synovitis is a disorder resulting in a villous, nodular, or villonodular proliferation of the synovium, with pigmentation related to the presence of hemosiderin. These lesions are almost exclusively benign with rare reports of malignancy. Pigmented villonodular synovitis can occur in a variety of joints and at any age but most often occurs within the knee in the young adult. Pigmented villonodular synovitis is a rare disease entity, and bilateral synchronous or metachronous involvement of a joint is even more uncommon, with few reports previously described in the literature. We present a case of pigmented villonodular synovitis involving both the right and left knee in the same patient, with radiographic imaging, magnetic resonance imaging, photograph and video intraoperative imaging, and pathologic correlation.

  10. Production of Monascus-like pigments

    DEFF Research Database (Denmark)

    2012-01-01

    The present invention relates to a method for producing one or more Monascus-like pigment composition from Penicillium species comprising: a) providing a cultivation medium comprising a high concentration of C-and N-sources and a high C/N molar ratio, b) adjusting pH to about 5 to 8, c) inoculating...... the cultivation medium with an inoculum of Penicillium to form a cultivation composition; d) cultivating the inoculated cultivation composition of (c); e) separating the one or more produced pigment compositions. The method of the invention may be used for producing Monascus-like pigment compositions for use...... as colouring agents in food items or non food items. The inventions further relates to Monascus-like pigment composition obtainable by a method of the inventions as well as use of the pigments....

  11. Novel micro-reactor flow cell for investigation of model catalysts using in situ grazing-incidence X-ray scattering

    DEFF Research Database (Denmark)

    Kehres, Jan; Pedersen, Thomas; Masini, Federico

    2016-01-01

    -incidence small-angle X-ray scattering (GISAXS) in transmission through 10 µm-thick entrance and exit windows by using micro-focused beams. An additional thinning of the Pyrex glass reactor lid allows simultaneous acquisition of the grazing-incidence wide-angle X-ray scattering (GIWAXS). In situ experiments......The design, fabrication and performance of a novel and highly sensitive micro-reactor device for performing in situ grazing-incidence X-ray scattering experiments of model catalyst systems is presented. The design of the reaction chamber, etched in silicon on insulator (SIO), permits grazing...

  12. Shape-selected nanocrystals for in situ spectro-electrochemistry studies on structurally well defined surfaces under controlled electrolyte transport: A combined in situ ATR-FTIR/online DEMS investigation of CO electrooxidation on Pt

    Science.gov (United States)

    Jusys, Zenonas; Behm, R Jürgen

    2014-01-01

    Summary The suitability and potential of shape selected nanocrystals for in situ spectro-electrochemical and in particular spectro-electrocatalytic studies on structurally well defined electrodes under enforced and controlled electrolyte mass transport will be demonstrated, using Pt nanocrystals prepared by colloidal synthesis procedures and a flow cell set-up allowing simultaneous measurements of the Faradaic current, FTIR spectroscopy of adsorbed reaction intermediates and side products in an attenuated total reflection configuration (ATR-FTIRS) and differential electrochemical mass spectrometry (DEMS) measurements of volatile reaction products. Batches of shape-selected Pt nanocrystals with different shapes and hence different surface structures were prepared and structurally characterized by transmission electron microscopy (TEM) and electrochemical methods. The potential for in situ spectro-electrocatalytic studies is illustrated for COad oxidation on Pt nanocrystal surfaces, where we could separate contributions from two processes occurring simultaneously, oxidative COad removal and re-adsorption of (bi)sulfate anions, and reveal a distinct structure sensitivity in these processes and also in the structural implications of (bi)sulfate re-adsorption on the CO adlayer. PMID:24991511

  13. Chemical characterization of pigment gallstones using 13C nuclear magnetic resonance analysis

    International Nuclear Information System (INIS)

    Woolfenden, W.R.; Grant, D.M.; Straight, R.C.; Englert, E. Jr.

    1982-01-01

    The unique ability of Carbon-13 nuclear magnetic resonance analysis with cross polarization/magic angle spinning techniques to investigate chemical structures of solids is used to probe the chemical characteristics of several gallstone types. New pulse program techniques are used to distinguish various carbon atoms in studying the polymeric nature of the black bilirubinoid pigment of pigment gallstones. Evidence for the involvement of the carboxyl group and noninvolvement of vinyl groups of bilirubinoids in the polymeric bond formation is presented. Conjugated bilirubin structures are found to be present in some solid residues from pigment stones extracted with acidic methanol/chloroform

  14. Synthesis and characterization of the Bi2Ce2-xZrxO7 pigments

    OpenAIRE

    Těšitelová, Kateřina; Šulcová, Petra; Koláčková, Iva

    2016-01-01

    This contribution is focused on the synthesis, characterization and optical properties of new inorganic pigments. The pigments were prepared by the solid-state reaction. The colour properties of prepared applications were investigated depending on the content of Zr and temperature of calcination (800-1000 °C after step 50 °C). The optimum conditions for the pigments synthesis were determined. Tento příspěvek je zaměřen na syntézu, charakterizaci a optické vlastnosti nových anorganických pi...

  15. Response surface optimization of the ultrasonic-assisted extraction of edible brown pigment from Macadamia shells

    Science.gov (United States)

    Liu, Y. Y.; Liu, Y. J.; Gong, X.; Li, J. H.

    2017-09-01

    The ultrasonic extraction of Edible brown pigment from macadamia shells was researched using response surface methodology (RSM) with 3 factors and 3 levels. A Box-Behnken design (BBD) was employed to investigate the effects of Solvent concentration, ratio of water to raw material and extraction time on the extraction yield of brown pigment. By using this new method, the optimum extraction condition was obtained as follows: Ultrasonic treating time 71 min, solvent to sample ratio of 23 mL/g, Alcohol concentrations 62%. Under the optimized condition, the experimental yield of brown pigment was 0.636g.

  16. Standard guidelines of care: Lasers for tattoos and pigmented lesions

    Directory of Open Access Journals (Sweden)

    Aurangabadkar Sanjeev

    2009-08-01

    Full Text Available Introduction: Lasers have revolutionized the treatment of pigmentary disorders and have become the mainstay of therapy for many of them. Machines: Though different laser machines are used, Quality-switched (QS lasers are considered as the gold standard for treatment of pigmented lesions. Proper knowledge of the physics of laser machine, methodology, dosage schedules, etc., is mandatory. Physician Qualification: Laser may be administered by a dermatologist, who has received adequate background training in lasers during postgraduation or later at a center that provides education and training in lasers, or in focused workshops which provide such trainings. He should have adequate knowledge of the machines, parameters, cooling systems, and aftercare. Facility: The procedure may be performed in the physician′s minor procedure room. Indications: Epidermal lesions: Cafι au lait macules (CALM, lentigines, freckles, solar lentigo, nevus spilus, pigmented seborrheic keratosis, dermatosis papulosa nigra (DPN. Dermal lesions: Nevus of Ota, Blue nevus, Hori′s nevus (acquired bilateral nevus of Ota-like macules. Tattoos: Amateur, professional, cosmetic, medicinal, and traumatic. Mixed epidermal and dermal lesions: Postinflammatory hyperpigmentation (PIH, nevus spilus, periorbital and perioral pigmentation, acquired melanocytic nevi (moles, melasma and Becker′s Nevus. Contraindications: Absolute: Active local infection, photo-aggravated skin diseases and medical conditions, tattoo granuloma, allergic reactions to tattoo pigment, unstable vitiligo and psoriasis. Relative: Keloid and keloidal tendencies, patient on isotretinoin, history of herpes simplex, patient who is not co-operative or has unrealistic expectation. Patient selection: Proper patient selection is important. Investigations to identify any underlying cause for pigmentation are important; concurrent topical and systemic drug therapy may be needed. History of scarring, response to previous

  17. Structure of plant bile pigments

    Energy Technology Data Exchange (ETDEWEB)

    Schoenleber, R.W.

    1983-12-01

    Selective peptide cleavage has provided a general procedure for the study of the structure, including stereochemistry, of plant bile pigments. The information derived from the synthesis and spectral analysis of a series of 2,3-dihydrodioxobilins allows the determination of the trans relative stereochemistry for ring A of the ..beta../sub 1/-phycocyanobilin from C-phycocyanin as well as for ring A of phytochrome. A complete structure proof of the five phycoerythrobilins attached to the ..cap alpha.. and ..beta.. subunits of B-phycoerythrin is described. One of these tetrapyrroles is doubly-peptide linked to a single peptide chain through two thioethers at the C-3' and C-18' positions. The four remaining phycoerythrobilins are singly-linked to the protein through thioethers at the C-3' position and all possess the probable stereochemistry C-2(R), C-3(R), C-3'(R), and C-16(R).

  18. Fungal and Bacterial Pigments: Secondary Metabolites with Wide Applications

    Science.gov (United States)

    Narsing Rao, Manik Prabhu; Xiao, Min; Li, Wen-Jun

    2017-01-01

    The demand for natural colors is increasing day by day due to harmful effects of some synthetic dyes. Bacterial and fungal pigments provide a readily available alternative source of naturally derived pigments. In contrast to other natural pigments, they have enormous advantages including rapid growth, easy processing, and independence of weather conditions. Apart from colorant, bacterial and fungal pigments possess many biological properties such as antioxidant, antimicrobial and anticancer activity. This review outlines different types of pigments. It lists some bacterial and fungal pigments and current bacterial and fungal pigment status and challenges. It also focuses on possible fungal and bacterial pigment applications. PMID:28690593

  19. Fungal and Bacterial Pigments: Secondary Metabolites with Wide Applications

    Directory of Open Access Journals (Sweden)

    Manik Prabhu Narsing Rao

    2017-06-01

    Full Text Available The demand for natural colors is increasing day by day due to harmful effects of some synthetic dyes. Bacterial and fungal pigments provide a readily available alternative source of naturally derived pigments. In contrast to other natural pigments, they have enormous advantages including rapid growth, easy processing, and independence of weather conditions. Apart from colorant, bacterial and fungal pigments possess many biological properties such as antioxidant, antimicrobial and anticancer activity. This review outlines different types of pigments. It lists some bacterial and fungal pigments and current bacterial and fungal pigment status and challenges. It also focuses on possible fungal and bacterial pigment applications.

  20. Investigating the complex relationship between in situ Southern Ocean pCO2 and its ocean physics and biogeochemical drivers using a nonparametric regression approach

    CSIR Research Space (South Africa)

    Pretorius, W

    2014-01-01

    Full Text Available the relationship more accurately in terms of MSE, RMSE and MAE, than a standard parametric approach (multiple linear regression). These results provide a platform for using the developed nonparametric regression model based on in situ measurements to predict p...

  1. Scale-up considerations for surface collecting agent assisted in-situ burn crude oil spill response experiments in the Arctic: Laboratory to field-scale investigations.

    Science.gov (United States)

    Bullock, Robin J; Aggarwal, Srijan; Perkins, Robert A; Schnabel, William

    2017-04-01

    In the event of a marine oil spill in the Arctic, government agencies, industry, and the public have a stake in the successful implementation of oil spill response. Because large spills are rare events, oil spill response techniques are often evaluated with laboratory and meso-scale experiments. The experiments must yield scalable information sufficient to understand the operability and effectiveness of a response technique under actual field conditions. Since in-situ burning augmented with surface collecting agents ("herders") is one of the few viable response options in ice infested waters, a series of oil spill response experiments were conducted in Fairbanks, Alaska, in 2014 and 2015 to evaluate the use of herders to assist in-situ burning and the role of experimental scale. This study compares burn efficiency and herder application for three experimental designs for in-situ burning of Alaska North Slope crude oil in cold, fresh waters with ∼10% ice cover. The experiments were conducted in three project-specific constructed venues with varying scales (surface areas of approximately 0.09 square meters, 9 square meters and 8100 square meters). The results from the herder assisted in-situ burn experiments performed at these three different scales showed good experimental scale correlation and no negative impact due to the presence of ice cover on burn efficiency. Experimental conclusions are predominantly associated with application of the herder material and usability for a given experiment scale to make response decisions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. In-Situ Nuclear Magnetic Resonance Investigation of Strain, Temperature, and Strain-Rate Variations of Deformation-Induced Vacancy Concentration in Aluminum

    NARCIS (Netherlands)

    Linga Murty, K.; Detemple, K.; Kanert, O.; Hosson, J.Th.M. De

    1998-01-01

    Critical strain to serrated flow in solid solution alloys exhibiting dynamic strain aging (DSA) or Portevin–LeChatelier effect is due to the strain-induced vacancy production. Nuclear magnetic resonance (NMR) techniques can be used to monitor in situ the dynamical behavior of point and line defects

  3. In-situ synchrotron X-Ray diffraction investigation of the fast recovery of microstructure during electropulse treatment of heavily cold drawn nanocrystalline Ni-Ti wires

    Czech Academy of Sciences Publication Activity Database

    Malard, B.; Pilch, Jan; Šittner, Petr; Delville, R.; Curfs, C.

    172-174, č. 6 (2011), s. 1243-1248 ISSN 1012-0394 R&D Projects: GA AV ČR(CZ) IAA200100627; GA MŠk(CZ) LA10010 Institutional research plan: CEZ:AV0Z10100520 Keywords : recovery process * electropulse treatment * in-situ analysis * superelasticity Subject RIV: BM - Solid Matter Physics ; Magnetism

  4. Visual acuity of fly photoreceptors in natural conditions - dependence on UV sensitizing pigment and light-controlling pupil

    NARCIS (Netherlands)

    Stavenga, DG

    The effect of the UV-absorbing sensitizing pigment fly photoreceptors on absolute, spectral and angular sensitivity was investigated with a wave-optics model for the facet lens-rhabdomere system. When sky light was used as a UV-rich light source, one sensitizing pigment molecule per rhodopsin

  5. Accelerating of Pink Pigment Excretion from Cyanobacterium Oscillatoria by Co-Cultivation with Anabaena

    Directory of Open Access Journals (Sweden)

    DWI SUSILANINGSIH

    2007-03-01

    Full Text Available The freshwater cyanobacterium Oscillatoria BTCC/A 0004 excretes pink pigment containing lipoproteins with molecular weights of about 10 kDa. This pigment has surfactant properties with strong emulsification activity toward several hydrocarbons. This extracellular metabolite was suspected as toxin or allelochemical in their habitat. In this study, I investigated the effect of co-cultivation of Oscillatoria with Anabaena variabilis on the pigment excretion to explore the physiological roles of this pigment in its natural environment. The dead or viable cells and medium of A. variabilis were added into Oscillatoria cultures. Results showed that co-cultivation of free viable cells of A. variabilis enhanced the excretion of pigment without effect on the cell growth. Co-cultivation with viable cells in separated method and dead cells did not influenced the pigment production. The addition of A. variabilis medium was slightly increased the excretion of the pigment. Those results indicated that direct contact with A. variabilis caused Oscillatoria released a certain signaling compound.

  6. Bio production of red pigment by local isolate of Monascus purpureus

    International Nuclear Information System (INIS)

    Youssef, B.M.; Khalaf, M.A.; Emam, D.A.; Hazaa, M.M.; Shash, S.M.

    2009-01-01

    There is an increased interest on natural pigments to replace some currently used synthetic dyes, since the latter have been associated with toxic effects in foods. The red pigment of the fungus Monascus is widely used in all the world as food additives or pharmaceuticals. The Monascus purpureus local strain, which was isolated from dried silage sample was employed for red pigment production in submerged fermentation (Sm F) conditions. Different fermentation parameters including: incubation period, temperature, initial ph of the medium, agitation, different carbon and nitrogen sources, bio elements and type of inoculum and its age; were carried out under Sm F conditions to enhance the red pigment production. The maximum red pigment production (1.27 gI -1 ) was achieved at incubation temperature 30 C, initial ph 5.5, agitation rate 150 rpm, 2% starch and 0.4% ammonium sulphate as carbon and nitrogen sources, respectively, after 4 days when the production medium inoculated with 12 h age from seed culture inoculum. An experiment was conducted to investigate the effect of gamma irradiation on the activity of Monascus purpureus towards red pigment production. The maximum red pigment production (I.9 gI -1 ) was obtained at 0.5 kGy dose level

  7. Effect of submerged and solid-state fermentation on pigment and citrinin production by Monascus purpureus.

    Science.gov (United States)

    Zhang, Liang; Li, Zhiqiang; Dai, Bing; Zhang, Wenxue; Yuan, Yongjun

    2013-09-01

    Monascus pigments, which are produced by various species of Monascus, often have been used as a natural colourant and as traditional natural food additives, especially in Southern China, Japan and Southeastern Asia. The limitation of wide using Monascus pigment is attributed to one of its secondary metabolites named citrinin. The aim of this study was to investigate the influence of pigment and citrinin production via submerged fermentation (SmF) and solid-state fermentation (SF) from rice (Oryza sativa L.) by Monascus purpureus AS3.531. The optimal fermentation temperature and pH were significantly different for pigment production through different fermentation mode (35 °C, pH 5.0 for SF and 32 °C, pH 5.5 for SmF, respectively). Adding 2% (w/v) of glycerol in the medium could enhance the pigment production. On the optimized condition, although the concentration of citrinin produced by SmF (19.02 ug/g) increased more than 100 times than that by SF (0.018 ug/g), the pigment yield by SmF (7.93 U/g/g) could be comparable to that by SF (6.63 U/g/g). Those indicate us that fermentation mode seems to be the primary factor which influence the citrinin yield and secondary factor for pigment production.

  8. The effect of acidified soapstocks on feed conversion and broiler skin pigmentation.

    Science.gov (United States)

    Pardio, V T; Landin, L A; Waliszewski, K N; Badillo, T C; Perez-Gil, F

    2001-08-01

    The effect of different soapstocks (corn, sunflower, canola, and soybean) on productive performance and skin broiler pigmentation was investigated. Soapstock was added to reach 1.0% polyunsaturated fatty acids in the diet. The addition of soybean soapstock significantly improved live body weight gain of the birds from 1 to 7 wk of age. A live body weight gain of 1,736 g/bird was calculated for broilers fed with the soybean soapstock diet. Feed conversion was significantly higher for broilers fed with the soybean soapstock diet, and no negative effect was observed. Compared to broilers fed with Pixtafil (100.0% pigmentation), those fed soybean soapstock (when added as a supplement of 1.0% polyunsaturated fatty acids in the diet) reached 48.0% pigmentation, and those fed corn soapstock reached only 7.3%. When the diets were complemented with Pixtafil to reach 100% of calculated pigmentation, the soybean soapstock diet reached 100.8% pigmentation compared to a canola soapstock diet that reached 72.0% pigmentation. Acidified soybean soapstock could be a source of polyunsaturated fatty acids and of xantophyl pigments in broiler feeding.

  9. Inhibitory effect of 5-iodotubercidin on pigmentation.

    Science.gov (United States)

    Kim, Kyung-Il; Jeong, Hae Bong; Ro, Hyunju; Lee, Jeung-Hoon; Kim, Chang Deok; Yoon, Tae-Jin

    2017-09-02

    Melanin pigments are the primary contributors for the skin color. They are produced in melanocytes and then transferred to keratinocytes, eventually giving various colors on skin surface. Although many depigmenting and/or skin-lightening agents have been developed, there is still a growing demand on materials for reducing pigmentation. We attempted to find materials for depigmentation and/or skin-lightening using the small molecule compounds commercially available, and found that 5-iodotubercidin had inhibitory potential on pigmentation. When HM3KO melanoma cells were treated with 5-iodotubercidin, pigmentation was dramatically reduced. The 5-iodotubercidin decreased the protein level for pigmentation-related molecules such as MITF, tyrosinase, and TRP1. In addition, 5-iodotubercidin decreased the phosphorylation of CREB, while increased the phosphorylation of AKT and ERK. These data suggest that 5-iodotubercidin inhibits melanogenesis via the regulation of intracellular signaling related with pigmentation. Finally, 5-iodotubercidin markedly inhibited the melanogenesis of zebrafish embryos, an in vivo evaluation model for pigmentation. Together, these data suggest that 5-iodotubercidin can be developed as a depigmenting and/or skin-lightening agent. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. The relationship between the violet pigment PP-V production and intracellular ammonium level in Penicillium purpurogenum.

    Science.gov (United States)

    Kojima, Ryo; Arai, Teppei; Matsufuji, Hiroshi; Kasumi, Takafumi; Watanabe, Taisuke; Ogihara, Jun

    2016-12-01

    Penicillium purpurogenum is the fungus that produces an azaphilone pigment. However, details about the pigment biosynthesis pathway are unknown. The violet pigment PP-V is the one of the main pigments biosynthesized by this fungus. This pigment contains an amino group in a pyran ring as its core structure. We focused on this pigment and examined the relationship between intracellular ammonium concentration and pigment production using glutamine as a nitrogen source. The intracellular ammonium level decreased about 1.5-fold in conditions favoring PP-V production. Moreover, P. purpurogenum was transferred to medium in which it commonly produces the related pigment PP-O after cultivating it in the presence or absence of glutamine to investigate whether this fungus biosynthesizes PP-V using surplus ammonium in cells. Only mycelia cultured in medium containing 10 mM glutamine produced the violet pigment, and simultaneously intracellular ammonium levels decreased under this condition. From comparisons of the amount of PP-V that was secreted with quantity of surplus intracellular ammonium, it is suggested that P. purpurogenum maintains ammonium homeostasis by excreting waste ammonium as PP-V.

  11. Magnetic resonance spectroscopy for measuring the biodistribution and in situ in vivo pharmacokinetics of fluorinated compounds: validation using an investigation of liver and heart disposition of tecastemizole.

    Science.gov (United States)

    Schneider, E; Bolo, N R; Frederick, B; Wilkinson, S; Hirashima, F; Nassar, L; Lyoo, I K; Koch, P; Jones, S; Hwang, J; Sung, Y; Villafuerte, R A; Maier, G; Hsu, R; Hashoian, R; Renshaw, P F

    2006-06-01

    The study of biodistribution and in situ pharmacokinetics is a challenging, but sometimes very important, aspect of premarketing characterization of drugs. We aimed to develop a non-invasive fluorine magnetic resonance (MR) spectroscopic method for the absolute quantitation of a mono-fluorinated compound and of its metabolites in the heart and liver of healthy subjects for this purpose. We used fluorine MR spectroscopy (MRS) at 4 T (Tesla) and external standardization in an open label multiple-dose study. Twenty-three healthy adult subjects were enrolled in the study. The surface coil localized fluorine MR spectrum was monitored in the heart and liver at baseline and after oral administration of multiple doses of tecastemizole. Steady-state measurements were made at set time points that depended upon dose, and washout measurements were made only on subjects in which in vivo fluorine signal was observed. At 4 T, under the given experimental conditions, the method had a lower limit of quantitation (LLOQ) of about 2.6 microm and a limit of detection (LOD) of about 0.3 microm for solution state samples (linewidth approximately 15 Hz). The measurement reproducibility was 6.4% using a 50 microm phantom. The effect of MR operator and spectral analyst on the calculated calibration curve slope was small, with inter-rater correlation coefficients of 0.999 and 0.998 respectively. MR signal from fluorine-containing tecastemizole-related moieties was observed in situ only at day 8 in the liver of three of five subjects dosed at 270 mg/day. The average in situ concentration was estimated to be 58+/-22 microm, with an average test-retest reproducibility of 216%. Extrapolating the in vitro results to human measurements, with an approximate linewidth of 250 Hz, predicts in situ LOD and LLOQ values of approximately 6 and 44 microm respectively. However, the human study had a fluorine MRS LOD of approximately 20 microm. The decrease in sensitivity and the increase in variability of

  12. In Situ 13C NMR at Elevated-Pressures and -Temperatures Investigating the Conversion of CO2 to Magnesium and Calcium Carbonate Minerals

    Science.gov (United States)

    Surface, J. A.; Conradi, M. S.; Skemer, P. A.; Hayes, S. E.

    2013-12-01

    We have constructed specialized NMR hardware to conduct in situ elevated-pressure, elevated-temperature 13C NMR studies of unmixed heterogeneous mixtures of solids, liquids, gases, and supercritical fluids. Specifically, our aim is to monitor CO2 uptake in both ultramafic rocks and in more porous geological materials to understand the mechanisms of chemisorption as a function of temperature, pressure and pH. In this in situ NMR probe, we are able to simulate processes at geologically relevant fluid pressures and temperatures, monitoring the kinetics of CO2 conversion to carbonates. The in situ NMR experiments consist of heterogeneous mixtures of rock, salty brine solution, and moderate pressure CO2 gas at elevated temperatures. The purpose of studying these reactions is to determine efficacy of carbonate formation in various geological reservoirs. Via 13C NMR, we have spectroscopically characterized and quantified the conversion of CO2 to magnesium carbonate and calcium carbonate minerals. When CO2 reacts with the calcium or magnesium in a mineral or rock sample, the 13C chemical shift, linewidth, lineshape, and relaxation times change dramatically. This change can be monitored in situ and provide instantaneous and continuous characterization that maps the chemistry that is taking place. For example, on the pathway to MgCO3 formation, there are a number of phases of Mg(OH)x(H2O)y(CO3)z that are apparent via NMR spectroscopy. We will demonstrate that NMR can be used for quantitative characterization of multiple metastable mineral phases in pure forms and in mixtures. Results are confirmed via powder XRD and Raman spectroscopy of aquo- hydro- carbonato- magnesium species and calcium carbonate species. We also have monitored the 13C spectroscopy to analyze the phase of CO2 (liquid, supercritical, or gas) and its conversion into other forms, such as bicarbonate and carbonate species, providing a "window" into the in situ pH of the reacting system. Reference: 'In Situ

  13. Extensive Pigmented Bowen's Disease of Genitalia

    OpenAIRE

    Şengezer, Mustafa; Şengezer, Naki; Deveci, Mustafa

    1993-01-01

    Genital bölgenin yaygın pigmente bowen hastalığı. Pigmente Bowen hastalığı oldukça nadirdir. Burada genital yörede yerleşimli yaygın bir bowen olgusu sunulmuş, klinik ve histolojik özellikleriyle pigmentasyon mekanizması ve tedavi yaklaşımları tartışılmıştır. Bowen hastalığı pigmente lezyonların ayrıca tanısında dikkate alınması gereken bir durumdur.

  14. Phenotypic plasticity in Drosophila pigmentation caused by temperature sensitivity of a chromatin regulator network.

    Directory of Open Access Journals (Sweden)

    Jean-Michel Gibert

    2007-02-01

    Full Text Available Phenotypic plasticity is the ability of a genotype to produce contrasting phenotypes in different environments. Although many examples have been described, the responsible mechanisms are poorly understood. In particular, it is not clear how phenotypic plasticity is related to buffering, the maintenance of a constant phenotype against genetic or environmental variation. We investigate here the genetic basis of a particularly well described plastic phenotype: the abdominal pigmentation in female Drosophila melanogaster. Cold temperature induces a dark pigmentation, in particular in posterior segments, while higher temperature has the opposite effect. We show that the homeotic gene Abdominal-B (Abd-B has a major role in the plasticity of pigmentation in the abdomen. Abd-B plays opposite roles on melanin production through the regulation of several pigmentation enzymes. This makes the control of pigmentation very unstable in the posterior abdomen, and we show that the relative spatio-temporal expression of limiting pigmentation enzymes in this region of the body is thermosensitive. Temperature acts on melanin production by modulating a chromatin regulator network, interacting genetically with the transcription factor bric-à-brac (bab, a target of Abd-B and Hsp83, encoding the chaperone Hsp90. Genetic disruption of this chromatin regulator network increases the effect of temperature and the instability of the pigmentation pattern in the posterior abdomen. Colocalizations on polytene chromosomes suggest that BAB and these chromatin regulators cooperate in the regulation of many targets, including several pigmentation enzymes. We show that they are also involved in sex comb development in males and that genetic destabilization of this network is also strongly modulated by temperature for this phenotype. Thus, we propose that phenotypic plasticity of pigmentation is a side effect reflecting a global impact of temperature on epigenetic mechanisms

  15. Investigation of in-situ poly(lactic acid)/soy protein concentrate composites: Composite preparation, properties and foam application development

    Science.gov (United States)

    Liu, Bo

    2011-12-01

    In this study, soy protein (SP), the residue of oil crushing, was used for preparation of value-added thermoplastics. Novel poly(lactic acid) (PLA)/soy protein concentrate (SPC) blends were investigated and foaming of the resulting blends was developed. PLA/SPC blends were prepared by twin-screw extrusion and test specimens by injection molding. Unlike the practice elsewhere SP was used as a filler in mixing with other polymers, SPC was processed as a plastic component in blending process in this work. Processing SPC as plastic component, water played an important role in terms of the deformability and the morphology of SP thus the properties of the blends. Plasticization of SP, compatibilization of the blends and structure-property relationship of the PLA/SPC blends were studied. In the literature water and glycerol were often used together in preparing SP plastics or plastic blends, but this study found that this traditional combination did not provide the best results in terms of morphology and mechanical properties. Water is only recommended in plasticizing SP in the blends. This study showed water as a plasticizer was a domain factor on control of morphology and properties of PLA/SPC blends. The due to the evaporation of water after extrusion, SP domain lost its deformability thus resulted in in-situ composites. Interconnected SPC phase structure was achieved by control water content in the pre-formulated SPC and SPC content in the blends. A novel dual compatibilization method was developed to improve the properties of PLA/SPC blends. Poly(2-ethyl-2-oxazoline) was used to improve the dispersion of SPC in the blending stage, and polymeric methylene diphenyl diisocyanate was used to improve the interfacial adhesion between SPC and PLA in the subsequent processing. The result showed excellent mechanical properties and improved thermal properties of PLA/SPC blends. Using processing aids is an effective way to decrease processing temperature and thermal degradation

  16. In situ and laboratory investigations of fluid flow through an argillaceous formation at different scales of space and time, Tournemire tunnel, southern France

    Science.gov (United States)

    Boisson, Jean-Yves; Bertrand, Lucien; Heitz, Jean-François; Golvan, Yann Moreau-Le

    2001-01-01

    In the context of a research and development program on waste disposal, an experimental site (Tournemire tunnel, Aveyron, France) was selected by the French Institute for Nuclear Protection and Safety (IPSN) in order to undertake studies on potential fluid flow at different scales of space and time within a 250-m-thick argillaceous formation. The argillite has a low natural water content ( 3-5%) and very low radii access porosity. Diffusion (tritiated water) coefficients (1×10-12 to 2×10-11 m2/s) and hydraulic conductivities derived from different types of laboratory tests (10-14 to 10-13 m/s) are characteristics of a very low-permeable rock. In situ hydraulic tests (including long-term hydraulic-head measurements) were used to obtain values for hydraulic head and hydraulic conductivity at a scale of 1-10 m (10-13 to 10-11 m/s). Despite uncertainties on these data (due to a scale factor, presence of fissures, and possible artefacts due to hydro-chemo-mechanical coupling), it is expected that fluid flow is essentially governed by diffusion processes. Identification of possible natural flows at larger scales of time and space was investigated using natural isotopic tracers from interstitial fluids. Modelling, based on the deuterium profile along the clay formation and assuming pure diffusion processes, provides estimations of possible flow times. However, lack of knowledge concerning the past geological evolution of the site and the possible role of a fracture network do not permit reduction of uncertainties on these estimations at this stage. Résumé. Dans le cadre de son programme de recherche et développement sur les stockages de déchets, un site expérimental (tunnel de Tournemire, Aveyron, France) a été sélectionné par l'Institut de Protection et Sûreté Nucléaire (IPSN) pour conduire des études sur les possibilités de transferts de fluides à différentes échelles de temps et d'espace au sein d'une formation argileuse de 250 m d'épaisseur. L

  17. In situ investigation of dye adsorption on TiO2 films using a quartz crystal microbalance with a dissipation technique

    KAUST Repository

    Harms, Hauke A.

    2012-01-01

    Dye adsorption plays a crucial role in dye-sensitized solar cells. Herein, we demonstrate an in situ liquid-phase analytical technique to quantify in real time adsorption of dye and coadsorbates on flat and mesoporous TiO 2 films. For the first time, a molar ratio of co-adsorbed Y123 and chenodeoxycholic acid has been measured. © 2012 the Owner Societies.

  18. Electrical estimulation of retinal pigment epithelial cells.

    Science.gov (United States)

    Gamboa, Olga Lucia; Pu, Jin; Townend, John; Forrester, John V; Zhao, Min; McCaig, Colin; Lois, Noemi

    2010-08-01

    We investigated and characterized the effect of externally applied electric fields (EF) on retinal pigment epithelial (RPE) cells by exposing primary cultures of human RPE cells (hRPE) and those from the ARPE19 immortalized cell line to various strengths of EF (EF-treated cells) or to no EF (control cells) under different conditions including presence or absence of serum and gelatin and following wounding. We evaluated changes in RPE cell behavior in response to EF by using a computer based image capture and analysis system (Metamorph). We found that RPE cells responded to externally applied EFs by preferential orientation perpendicular to the EF vector, directed migration towards the anode, and faster translocation rate than control, untreated cells. These responses were voltage-dependent. Responses were observed even at low voltages, of 50-300 mV. Furthermore, the migration of hRPE cell sheets generated by wounding of confluent monolayers of cells at early and late confluence could be manipulated by the application of EF, with directed migration towards the anode observed at both sides of the wounded hRPE. In conclusion, RPE cell behaviour can be controlled by an externally applied EF. The potential for externally applied EF to be used as a therapeutic strategy in the management of selected retinal diseases warrants further investigation. Copyright 2010 Elsevier Ltd. All rights reserved.

  19. In situ UV–vis investigation of growth of gold nanoparticles prepared by solution plasma sputtering in NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Mizutani, Tsuyoshi, E-mail: mizutani.tsuyoshi@g.mbox.nagoya-u.ac.jp [Division of Quantum Science and Energy Engineering, Department of Materials, Physics and Energy Engineering, School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Ogawa, Satoshi [Division of Quantum Science and Energy Engineering, Department of Materials, Physics and Energy Engineering, School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Murai, Takaaki; Nameki, Hirofumi [Aichi Center for Industry and Science Technology, Onda, Kariya, Aichi 448-0013 (Japan); Yoshida, Tomoko; Yagi, Shinya [EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2015-11-01

    Highlights: • In situ UV–vis measurement reveals diameters of gold nanoparticles and concentrations of gold. • Ostwald ripening of gold nanoparticles occurs in NaCl solution. • We estimate equilibrium diameters of gold nanoparticles in various concentrations of NaCl solution. - Abstract: Gold nanoparticles are prepared in various concentrations of NaCl solutions by solution plasma sputtering. The absorption spectra of these solutions during and after the plasma process are measured by in situ ultraviolet–visible (UV–vis) spectroscopy to estimate the particle diameters and concentrations of gold. The distributions of particle diameters are obtained by transmission electron microscope (TEM) observations. These experiments indicate the gold nanoparticles with about 2.2 nm are directly formed by plasma phase and the diameters are increasing over time. These increases of particle diameters are caused by Ostwald ripening of gold nanoparticles in NaCl solution. We estimate the equilibrium diameter at which the gold nanoparticles are not solved in NaCl solution using in situ UV–vis spectroscopy. These diameters are about 5, 7 and 10 nm in 3, 5 and 10 mM NaCl solution, respectively. We make it possible to control the diameter of gold nanoparticles prepared by solution plasma sputtering in NaCl solution.

  20. Raman and Infrared Absorption Study of Indigoid-based Pigments

    Science.gov (United States)

    Manciu, Felicia; Durrer, William; Reza, Layra; Ramirez, Alejandra; Chianelli, Russell

    2009-04-01

    A fascinating aspect of Maya pigments is that despite the environmentally harsh humidity and high temperatures they resist fading and they have unprecedented stability. In this investigation, we address the question of how organic dye binds to inorganic palygorskite to form pigments. Our analysis by Raman and infrared absorption spectroscopies proves that different processes are taking place for the indigo-palygorskite system as compared with the thioindigo-palygorskite complex. While partial elimination of the selection rules for the centrosymmetric indigo and disappearance of the indigo N-H bonding, with conversion to dehydroindigo, is observed for the first compound, the latter shows no evident structure modification. The interaction between indigo and palygorskite is likely through oxygen and nitrogen. Only oxygen plays this role for the thioindigo-palygorskite complex.

  1. Activation of muscarinic acetylcholine receptors elicits pigment granule dispersion in retinal pigment epithelium isolated from bluegill

    Directory of Open Access Journals (Sweden)

    Crittenden Elizabeth L

    2004-07-01

    Full Text Available Abstract Background In fish, melanin pigment granules in the retinal pigment epithelium disperse into apical projections as part of the suite of responses the eye makes to bright light conditions. This pigment granule dispersion serves to reduce photobleaching and occurs in response to neurochemicals secreted by the retina. Previous work has shown that acetylcholine may be involved in inducing light-adaptive pigment dispersion. Acetylcholine receptors are of two main types, nicotinic and muscarinic. Muscarinic receptors are in the G-protein coupled receptor superfamily, and five different muscarinic receptors have been molecularly cloned in human. These receptors are coupled to adenylyl cyclase, calcium mobilization and ion channel activation. To determine the receptor pathway involved in eliciting pigment granule migration, we isolated retinal pigment epithelium from bluegill and subjected it to a battery of cholinergic agents. Results The general cholinergic agonist carbachol induces pigment granule dispersion in isolated retinal pigment epithelium. Carbachol-induced pigment granule dispersion is blocked by the muscarinic antagonist atropine, by the M1 antagonist pirenzepine, and by the M3 antagonist 4-DAMP. Pigment granule dispersion was also induced by the M1 agonist 4-[N-(4-chlorophenyl carbamoyloxy]-4-pent-2-ammonium iodide. In contrast the M2 antagonist AF-DX 116 and the M4 antagonist tropicamide failed to block carbachol-induced dispersion, and the M2 agonist arecaidine but-2-ynyl ester tosylate failed to elicit dispersion. Conclusions Our results suggest that carbachol-mediated pigment granule dispersion occurs through the activation of Modd muscarinic receptors, which in other systems couple to phosphoinositide hydrolysis and elevation of intracellular calcium. This conclusion must be corroborated by molecular studies, but suggests Ca2+-dependent pathways may be involved in light-adaptive pigment dispersion.

  2. Pigmentation Disorders: Diagnosis and Management.

    Science.gov (United States)

    Plensdorf, Scott; Livieratos, Maria; Dada, Nabil

    2017-12-15

    Pigmentation disorders are commonly diagnosed, evaluated, and treated in primary care practices. Typical hyperpigmentation disorders include postinflammatory hyperpigmentation, melasma, solar lentigines, ephelides (freckles), and café au lait macules. These conditions are generally benign but can be distressing to patients. Appropriate dermatologic history, skin examination, and skin biopsy, when appropriate, can help exclude melanoma and its precursors. In addition to addressing the underlying condition, hyperpigmentation is treated with topical agents, chemical peels, cryotherapy, light or laser therapy, or a combination of these methods. Café au lait macules are treated with surgical excision or laser therapy if treatment is desired. Hypopigmentation disorders include vitiligo, pityriasis alba, tinea versicolor, and postinflammatory hypopigmentation. Treatment of vitiligo depends on the distribution and extent of skin involvement, and includes topical corticosteroids and calcineurin inhibitors, ultraviolet A therapy (with or without psoralens), narrowband ultraviolet B therapy, and cosmetic coverage. Patients with stable, self-limited vitiligo may be candidates for surgical grafting techniques, whereas those with extensive disease may be candidates for depigmentation therapy to make skin tone appear more even. Other hypopigmentation disorders may improve or resolve with treatment of the underlying condition.

  3. [Pigmented lesions of the oral mucosa].

    Science.gov (United States)

    Beck-Mannagetta, J; Hutarew, G

    2012-09-01

    The oral mucosa contains melanocytes, even though one might not suspect this when examining white subjects. Drug-induced pigmentation is usually irregularly distributed over the oral mucosa; typical causes are contraceptives and tetracyclines. Localized traumatic pigmentation can be due to injuries contaminated by foreign material (dust). Not infrequently an amalgam tattoo can be seen, caused by introduction of amalgam during dental treatment with rotating instruments. Focal melanosis is harmless. Neoplastic pigmentation is rare. Melanotic nevi are small with indistinct borders. Malignant melanoma occurs predominantly on the maxilla or hard palate. Frequently it has already metastasized by the time of diagnosis. Verification by biopsy is essential if a lesion has suddenly appeared, is extensive, elevated, with irregular pigmentation and has no obvious cause.

  4. Pigmented xerodermoid - Report of three cases

    Directory of Open Access Journals (Sweden)

    Das Jayanta Kumar

    2005-01-01

    Full Text Available Pigmented xerodermoid, a rare genodermatosis, presents with clinical features and pathology similar to xeroderma pigmentosum, but at a later age. DNA repair replication is normal, but there is total depression of DNA synthesis after exposure to UV radiation. Two siblings in their teens and a man in his thirties with features of pigmented xerodermoid, e.g. photophobia, freckle-like lesions, keratoses, dryness of skin, and hypo- and hyper-pigmentation, are described. Although classically the onset of pigmented xerodermoid is said to be delayed till third to fourth decade of life, it seems the disease may appear earlier in the tropics. Early diagnosis and management could be life-saving.

  5. Pigment Production Analysis in Human Melanoma Cells.

    Science.gov (United States)

    Hopkin, Amelia Soto; Paterson, Elyse K; Ruiz, Rolando; Ganesan, Anand K

    2016-05-25

    The human epidermal melanocyte is a highly specialized pigmented cell that serves to protect the epidermis from ultraviolet (UV) damage through the production of melanin, or melanogenesis. Misregulation in melanogenesis leading to either hyper- or hypo-pigmentation is found in human diseases such as malasma and vitiligo. Current therapies for these diseases are largely unsuccessful and the need for new therapies is necessary. In order to identify genes and or compounds that can alter melanogenesis, methods are required that can detect changes in pigment production as well as expression of key melanogenesis transcription factors and enzymes. Here we describe methods to detect changes in melanogenesis in a human melanoma cell line, MNT-1, by (1) analyzing pigment production by measuring the absorbance of melanin present by spectrophotometry, (2) analyzing transcript expression of potent regulators of melanogenesis by qunatitative reverse-transcription (RT)PCR and (3) analyzing protein expression of potent regulators of melanogenesis by Western blot (WB).

  6. Characteristic Elemental Composition of Oil Pigments using Instrumental Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Chung, Yong Sam; Kim, Sun Ha; Sun, Gwang Min; Lim, Jong Myung; Moon, Jong Hwa; Kim, Young Jin; Lim, Sung Jin; Song, Yu Na; Kim, Ken

    2009-01-01

    The principal aim of this study is to identify the applicability of instrumental neutron activation analysis as a non-destructive examination tool for the quantitative composition analysis associated with authentication, restoration, and conservation of art objects in the field of cultural heritage. Generally, the chemical composition of pigments are associated with the colors such as white, yellow, orange, red, green, blue and black, and it varies with raw materials of pigments. According to the colors of a different pigments, chemical compositions are as follows; for example, white pigments were used for a mixture of Pb(CO 3 ) 2 , PbSO 4 , PbO, Pb(OH) 2 , ZnO, ZnS, TiO 2 , BaSO 4 , CaCO 3 , Al 2 O 3 , As 2 S 3 , etc.; black pigments were series of carbon black, borne ash, MnO+Mn 2 O 3 , etc.; red pigments were Fe 2 O 3 , Pb 3 O 4 , HgS, PbMo 4 , CdS+CdSe, etc.; brown and yellow pigments were PbCrO 4 , ZnCrO 4 , CdS-ZnS, K 3 [Co(NO 2 ) 6 ], Pb(SbO 3 ) 2 , C 19 H 16 O 11 Mg, SrCrO 4 , etc.; green pigments were Cr 2 O 3 , Cr 2 O(OH) 4 , Cu(C 2 H 3 O 2 )-2Cu(OH) 2 ), Cr 2 O 3 -Al 2 O 3 -CoO, etc.; blue pigments were Fe 4 [Fe(CN) 6 ] 3 , CoO-Al 2 O 3 , Na 8 - 10 Al 6 Si 6 O 24 S 2-4 , etc. This first step is to obtain quantitative data on the concentrations of major, minor and trace elements in oil pigments and to explain pigment sources by statistical treatment as reported in many literatures. The determination of major, minor and micro elements in the subject materials are essential in many fields of basic science and technology as well as commercial and industrial fields. In particular, direct analysis of a sample offers a more effective investigation method in these fields. Instrumental neutron activation analysis (INAA) has an inherent advantage of being a non-destructive, simultaneously multi-elemental analysis with high accuracy and sensitivity. In order to characterize the elemental contents of art objects, the quantitative analysis of oil pigment series was

  7. Crystal Engineering on Industrial Diaryl Pigments Using Lattice Energy Minimizations and X-ray Powder Diffraction

    International Nuclear Information System (INIS)

    Schmidt, M.; Dinnebier, R.; Kalkhof, H.

    2007-01-01

    Diaryl azo pigments play an important role as yellow pigments for printing inks, with an annual pigment production of more than 50,000 t. The crystal structures of Pigment Yellow 12 (PY12), Pigment Yellow 13 (PY13), Pigment Yellow 14 (PY14), and Pigment Yellow 83 (PY83) were determined from X-ray powder data using lattice energy minimizations and subsequent Rietveld refinements. Details of the lattice energy minimization procedure and of the development of a torsion potential for the biphenyl fragment are given. The Rietveld refinements were carried out using rigid bodies, or constraints. It was also possible to refine all atomic positions individually without any constraint or restraint, even for PY12 having 44 independent non-hydrogen atoms per asymmetric unit. For PY14 (23 independent non-hydrogen atoms), additionally all atomic isotropic temperature factors could be refined individually. PY12 crystallized in a herringbone arrangement with twisted biaryl fragments. PY13 and PY14 formed a layer structure of planar molecules. PY83 showed a herringbone structure with planar molecules. According to quantum mechanical calculations, the twisting of the biaryl fragment results in a lower color strength of the pigments, whereas changes in the substitution pattern have almost no influence on the color strength of a single molecule. Hence, the experimentally observed lower color strength of PY12 in comparison with that of PY13 and PY83 can be explained as a pure packing effect. Further lattice energy calculations explained that the four investigated pigments crystallize in three different structures because these structures are the energetically most favorable ones for each compound. For example, for PY13, PY14, or PY83, a PY12-analogous crystal structure would lead to considerably poorer lattice energies and lower densities. In contrast, lattice energy calculations revealed that PY12 could adopt a PY13-type structure with only slightly poorer energy. This structure was

  8. Quantitative determination of total pigments in red meats using hyperspectral imaging and multivariate analysis.

    Science.gov (United States)

    Xiong, Zhenjie; Sun, Da-Wen; Xie, Anguo; Pu, Hongbin; Han, Zhong; Luo, Man

    2015-07-01

    This study investigated the potential of hyperspectral imaging (HSI) for quantitative determination of total pigments in red meats, including beef, goose, and duck. Partial least squares regression (PLSR) was applied to correlate the spectral data with the reference values of total pigments measured by a traditional method. In order to simplify the PLSR model based on the full spectra, eleven optimal wavelengths were selected using successive projections algorithm (SPA). The new SPA-PLSR model yielded good results with the coefficient of determination (R(2)p) of 0.953, root mean square error (RMSEP) of 9.896, and ratio of prediction to deviation (RPD) of 4.628. Finally, distribution maps of total pigments in red meats were developed using an image processing algorithm. The overall results from this study indicated HSI had the capability for predicting total pigments in red meats. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Antioxidative role of ocular melanin pigment in the model of lens induced uveitis.

    Science.gov (United States)

    Bilgihan, A; Bilgihan, M K; Akata, R F; Aricioğlu, A; Hasanreisoğlu, B

    1995-12-01

    Ocular melanin pigment has antioxidant effect against excess of dispersed light. To investigate whether it has a similar effect in ocular inflammations, we used albino and pigmented guinea pigs and measured retinal glutathione peroxidase activities and lipid peroxide levels (expressed as thiobarbituric acid reactive substances) in a model of lens induced uveitis. Although the increase in the levels of the retinal lipid peroxides were higher in the albino group (204%, p < 0.05), the decrease in the activities of glutathione peroxidase were higher in pigmented guinea pigs (26%, p < 0.005). The results of the study suggest that pigmentless animals are more sensitive to the ocular inflammations, and ocular melanin pigment may act as an endojen antioxidant in lens induced uveitis.

  10. Radiation Stability of Zinc Oxide Pigment Modified by Zirconium Oxide and Aluminum Oxide Nanopowders

    International Nuclear Information System (INIS)

    Mikhailov, M. M.; Neshchimenko, V. V.; Li Chundong

    2009-01-01

    The effect on the reflective spectra of heat treatment and modification of ZnO pigments by 1-30 wt.%ZrO 2 and Al 2 O 3 nanoparticles has been investigated before and after irradiation by 100 keV protons with a fluence of 5x10 15 cm -2 . It is established that with the optimum concentration of 5 wt.% nanoparticles and the temperature of 800 deg. C a 20% increase in the radiation stability is observed for the modified ZnO pigment in comparison with the not modified pigment. The decrease of absorption in the modified pigments is determined by the decrease of the intensity of the absorption bands of the zinc vacancies (V zn - ), oxygen vacancies (V o + ) and donor-acceptor couples (V zn - - Zn i 0 ).

  11. Analysis of the laser-induced discoloration of lead white pigment

    International Nuclear Information System (INIS)

    Cooper, M.I.; Fowles, P.S.; Tang, C.C.

    2002-01-01

    The use of laser cleaning in artwork conservation is becoming increasingly important. An investigation into the effects of laser radiation on lead white pigment, considered to be historically the most important of all white pigments used in art, has been undertaken. Samples of pigment and pigment in a water-colour binding medium have been prepared and irradiated by laser radiation at 1064 nm (pulse duration 5-10 ns) at an average fluence of 0.3 J cm -2 . Irradiation under such conditions leads to the formation of an extremely thin discoloured layer. Synchrotron X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) have been used to characterise the altered layer. Analytical evidence for the formation of elemental lead is presented for the first time and the effect of exposure of the altered layer to air and the effect of a binding medium on the process are discussed

  12. Quantitative analysis of pigment dispersion taking into account the full agglomerate size distribution

    DEFF Research Database (Denmark)

    Kiil, Søren

    This work concerns the development of simulation tools for mapping of pigment dispersion. Focus has been on the mechanical breakage of pigment agglomerates. The underlying physical mechanism was assumed to be surface erosion of spherical pigment agglomerates, and the full agglomerate particle size...... distribution was simulated. Data from previous experimental investigations with organic pigments were used for model validation.When the linear rate of agglomerate surface erosion was taken to be proportional to the external agglomerate surface area, simulations of the volume-moment mean diameter over time...... were in good quantitative agreement with experimental data. The only adjustable parameter used was an apparent rate constant for the linear agglomerate erosion rate. Model simulations, at selected values of time, for the full agglomerate particle size distribution were in good qualitative agreement...

  13. Microbial Production of Food Grade Pigments

    Directory of Open Access Journals (Sweden)

    Laurent Dufossé

    2006-01-01

    Full Text Available The controversial topic of synthetic dyes in food has been discussed for many years. The scrutiny and negative assessment of synthetic food dyes by the modern consumer have raised a strong interest in natural colouring alternatives. Nature is rich in colours (minerals, plants, microalgae, etc., and pigment-producing microorganisms (fungi, yeasts, bacteria are quite common. Among the molecules produced by microorganisms are carotenoids, melanins, flavins, quinones, and more specifically monascins, violacein or indigo. The success of any pigment produced by fermentation depends upon its acceptability on the market, regulatory approval, and the size of the capital investment required to bring the product to market. A few years ago, some expressed doubts about the successful commercialization of fermentation-derived food grade pigments because of the high capital investment requirements for fermentation facilities and the extensive and lengthy toxicity studies required by regulatory agencies. Public perception of biotechnology-derived products also had to be taken into account. Nowadays some fermentative food grade pigments are on the market: Monascus pigments, astaxanthin from Xanthophyllomyces dendrorhous, Arpink Red from Penicillium oxalicum, riboflavin from Ashbya gossypii, b-carotene from Blakeslea trispora. The successful marketing of pigments derived from algae or extracted from plants, both as a food colour and a nutritional supplement, reflects the presence and importance of niche markets in which consumers are willing to pay a premium for »all natural ingredients«.

  14. Antimicrobial activity of Micrococcus luteus Cartenoid pigment

    Directory of Open Access Journals (Sweden)

    Huda Z. Majeed

    2017-11-01

    Full Text Available Cartenoids are group of pigments, with enormous types different structurally and functionally, have colors range from red to yellow found in a wide variety of plants, fungi, algae and bacteria. The animals took from food because they cannot make it, on contrary, the plants and microbes produce them due to subjection to environment. The aim of the study is to isolate and characterize the cartenoid pigment from Micrococcus luteus. The pigment extraction was done by acetone, and then was characterized with UltraViolet-Visible spectroscopy (UV–Vis and Fourier Transform Infrared (FTIR spectroscopy. Then, it was tested for antibacterial activity against five different bacterial isolates and antifungal activity tests against six different fungal isolates by well diffusion method. The results found that, the extracted pigment having antibacterial activity and antifungal activity and having the ability to absorb UVA rays within the range of 300-500 nm. There was no significant difference in antimicrobial effect of pigment, even when the extraction and isolation were done by two culture mediums (Nutrient Broth and Luria Bertani Broth. There were considerable inhibition percentages of adhesion after subjection to Cartenoid pigment ranged between (5.71, 23.84 % for Klebsiella spp. and Pseudomonas aeruginosa respectively and all the 11 isolate changed from Biofilm producer to non-producer. The isolated compound can be used against different bacterial and fungal infections. So they had a great future in medicine, cosmetics and as a sun protecting agent.

  15. STABILITY OF BETACYANIN PIGMENTS FROM RED PURPLE PITAYA FRUIT (Hylocereus polyrhizus : INFLUENCE OF PH, TEMPERATURE, METAL IONS AND ASCORBIC ACID

    Directory of Open Access Journals (Sweden)

    Tang, C.S Tang, C.S

    2010-06-01

    Full Text Available Betacyanin pigments from red-purple pitaya fruit (Hylocereus polyrhizus could be an attractive source of red colourant for food application. This paper presents results on the extraction of betacyanin pigments from pitaya fruits grown locally in Malaysia. Both the flesh of the fruit and its mesocarp were investigated and it was found that the flesh had higher pigment contents compared to its peel component. The concentration of betacyanins expressed as betanin equivalents per 100 g of flesh and peel were 10.1 ± 0.6 mg and 6.7 ± 0.2 mg, respectively when 80% methanol was used.  The stability of betacyanin pigments were investigated at different pH, temperature and in presence of different concentrations of metal ions (Cu2+ and Fe2+ and ascorbic acid. The results showed that the pigment was most stable at pH range between 5 and 6. However, it forfeited its stability to the heat induced at elevated temperatures. Metal ions (Cu2+ and Fe2+ proved to be capable of accelerating betacyanin degradation, with Cu2+ exhibiting the greatest effect. By contrast, supplementation with ascorbic acid could enhance the pigment stability against the detrimental effects caused by pH, temperature and metal ions. Nevertheless, if the concentration of ascorbic acid exceeds 0.7 %, it may change its role from pigment stabilizer to become a pro-oxidant.    Keywords: Betacyanin, pigments, pitaya fruit, Hylocereus polyrhizus, ascorbic acid

  16. Studying the stabilization of vegetable pigments using 14C

    International Nuclear Information System (INIS)

    Inanejshvili, Zh.A.; Prokof'eva, M.C.

    1975-01-01

    With the help of labeled cathine tea-leaf substance it has been discovered that the later forms a specific complex with the red beet pigment. This obviously appears to be the reason for the pigment stability. An increase of the labeled cathine substance portion taken to stabilize the red pigment leads to lowering down the portion of the labeled pigment taking part in the reaction. The results from the experiment can be practically used in food industry for plant pigments

  17. Pigment Production from Immobilized Monascus sp. Utilizing Polymeric Resin Adsorption

    OpenAIRE

    Evans, Patrick J.; Wang, Henry Y.

    1984-01-01

    Pigment production by the fungus Monascus sp. was studied to determine why Monascus sp. provides more pigment in solid culture than in submerged culture. Adding a sterilized nonionic polymeric adsorbent resin directly to the growing submerged culture did not enhance the pigment production, thus indicating that pigment extraction is probably not a factor. Monascus cells immobilized in hydrogel were studied and exhibited decreased pigment production as a result of immobilization. This result is...

  18. A novel molten-salt electrochemical cell for investigating?the reduction of uranium dioxide to uranium metal by lithium using in situ synchrotron radiation

    OpenAIRE

    Brown, Leon D.; Abdulaziz, Rema; Jervis, Rhodri; Bharath, Vidal; Mason, Thomas J.; Atwood, Robert C.; Reinhard, Christina; Connor, Leigh D.; Inman, Douglas; Brett, Daniel J. L.; Shearing, Paul R.

    2017-01-01

    A novel electrochemical cell has been designed and built to allow for in situ energy-dispersive X-ray diffraction measurements to be made during reduction of UO2 to U metal in LiCl?KCl at 500?C. The electrochemical cell contains a recessed well at the bottom of the cell into which the working electrode sits, reducing the beam path for the X-rays through the molten-salt and maximizing the signal-to-noise ratio from the sample. Lithium metal was electrodeposited onto the UO2 working electrode b...

  19. Pigment granule translocation in red ovarian chromatophores from the palaemonid shrimp Macrobrachium olfersi (Weigmann, 1836): functional roles for the cytoskeleton and its molecular motors.

    Science.gov (United States)

    Milograna, Sarah Ribeiro; Ribeiro, Márcia Regina; Baqui, Munira Muhammad Abdel; McNamara, John Campbell

    2014-12-01

    The binding of red pigment concentrating hormone (RPCH) to membrane receptors in crustacean chromatophores triggers Ca²⁺/cGMP signaling cascades that activate cytoskeletal motors, driving pigment granule translocation. We investigate the distributions of microfilaments and microtubules and their associated molecular motors, myosin and dynein, by confocal and transmission electron microscopy, evaluating a functional role for the cytoskeleton in pigment translocation using inhibitors of polymer turnover and motor activity in vitro. Microtubules occupy the chromatophore cell extensions whether the pigment granules are aggregated or dispersed. The inhibition of microtubule turnover by taxol induces pigment aggregation and inhibits re-dispersion. Phalloidin-FITC actin labeling, together with tannic acid fixation and ultrastructural analysis, reveals that microfilaments form networks associated with the pigment granules. Actin polymerization induced by jasplaquinolide strongly inhibits RPCH-induced aggregation, causes spontaneous pigment dispersion, and inhibits pigment re-dispersion. Inhibition of actin polymerization by latrunculin-A completely impedes pigment aggregation and re-dispersion. Confocal immunocytochemistry shows that non-muscle myosin II (NMMII) co-localizes mainly with pigment granules while blebbistatin inhibition of NMMII strongly reduces the RPCH response, also inducing spontaneous pigment dispersion. Myosin II and dynein also co-localize with the pigment granules. Inhibition of dynein ATPase by erythro-9-(2-hydroxy-3-nonyl) adenine induces aggregation, inhibits RPCH-triggered aggregation, and inhibits re-dispersion. Granule aggregation and dispersion depend mainly on microfilament integrity although microtubules may be involved. Both cytoskeletal polymers are functional only when subunit turnover is active. Myosin and dynein may be the molecular motors that drive pigment aggregation. These mechanisms of granule translocation in crustacean

  20. An investigation of the feasibility of applying Raman microscopy for exploring stained glass

    Science.gov (United States)

    Bouchard, Michel; Smith, David C.; Carabatos-Nédelec, Constantin

    2007-12-01

    Raman microscopy (RM) is widely used in archaeometrical studies of pigments, geomaterials and biomaterials in the Cultural Heritage, but one domain has received relatively less attention: the colouring of stained glass. This feasibility study investigates the advantages and disadvantages of employing RM alone in this field by means of a study of modern commercial glasses, modern commercial pigments, and a few archaeological stained glasses, but especially by an experimental project whereby the authors created stained glass. The different kinds of possible unreacted or reacted material are rigorously established. The distinction between Na, K, Ca glasses was explored, as well as the red colouring of an industrial glass which was proved to be due to the presence of (Zn, Cd)S xSe 1- x. Yellow, green, blue and maroon pigments were studied before and after an initial firing and then after heating on glass. The quality of the Raman spectra varied enormously and was sometimes disappointing. Nevertheless RM successfully identified various coloured products such as bindheimite, crocoite, cobalt aluminate, haematite; relict reactants such as corundum, eskolaite and oxides of Co or Pb; and provided indications of other phases such as maghemite or Co-olivine. One conclusion is that the amount of chemical reaction between the pigments and the glass is small compared to the amount in between the pigments. Comments are made on the potential for dating archaeological glass from the known age of synthesis of the pigments, and of the dangers of this approach. Overall it has been shown that RM can be useful for studying stained glass, especially for remote in situ analytical operations with mobile RM, but one must expect some problems either with fluorescence or weak spectra.

  1. Effect of porphobilinogen on the formation of garlic green pigments.

    Science.gov (United States)

    Mou, Conghua; Hao, Xiaoran; Xu, Zhixiang; Qiao, Xuguang

    2013-08-15

    Garlic (Allium sativum L.) bulb is processed into various forms such as crushed garlic, garlic juice, granules, dehydrated garlic pieces and garlic powder. However, greening is often a major problem when garlic is crushed, since it affects the appearance and quality of the resulting product. Therefore study of the formation mechanism of garlic green pigments is very important for garlic processing. The effect of porphobilinogen (PBG) on the formation of garlic green pigments was investigated in this study. As the storage time increased, there was a significant positive correlation between garlic greening and PBG content at low temperature (4 °C). PBG content decreased significantly during the garlic greening process. When treated with respiration inhibitor, both garlic greening strength and PBG content decreased as the concentration of respiration inhibitor increased. The green colour was generated when extracted PBG and allicin mixed thoroughly. There was a clear relationship between PBG content and garlic greening. As a provider of pyrrolyl compounds, PBG plays an important role in the formation of garlic green pigments. © 2013 Society of Chemical Industry.

  2. Comparative analysis of pigments in red and yellow banana fruit.

    Science.gov (United States)

    Fu, Xiumin; Cheng, Sihua; Liao, Yinyin; Huang, Bingzhi; Du, Bing; Zeng, Wei; Jiang, Yueming; Duan, Xuewu; Yang, Ziyin

    2018-01-15

    Color is an important characteristic determining the fruit value. Although ripe bananas usually have yellow peels, several banana cultivars have red peels. As details of the pigments in banana fruits are unknown, we investigated these pigments contents and compositions in the peel and pulp of red cultivar 'Hongjiaowang' and yellow cultivar 'Baxijiao' by UPLC-PDA-QTOF-MS and HPLC-PDA techniques. The 'Hongjiaowang' peel color was mainly determined by the presence of anthocyanin-containing epidermal cells. Rutinoside derivatives of cyanidin, peonidin, petunidin, and malvidin were unique to the red peel, and possibly responsible for the red color. 'Hongjiaowang' contained higher total content of carotenoids than 'Baxijiao' in both pulp and peel. Lutein, α-carotene, and β-carotene were main carotenoids, which might play a more important role than flavonoids in producing the yellow banana color owing to the properties and distribution in the fruit. The information will help us understand a complete profile of pigments in banana. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Synthesis and Characterization of Nanosized Fe2O3 Pigments

    Directory of Open Access Journals (Sweden)

    M. F. R. Fouda

    2012-01-01

    Full Text Available The work in this paper was devoted to investigating some nanosized iron oxide pigments prepared by microemulsion technique. The role of concentration of iron salt and surfactant (cetyltrimethylammonium bromide on the produced iron oxide was studied. The techniques employed to characterize the samples were thermogravimetric analysis, X-ray diffractometry, transmission electron microscope, infrared spectroscopy, and diffuse reflectance spectroscopy. The results revealed that the particle size of the prepared sample using 0.2 M iron sulfate and 3.2 wt% of surfactant was in the range 7–9 nm. Increasing the concentration of either iron salt or the surfactant increased the particle size of the obtained ferric oxide. The diffuse reflectance measurements showed that the charge transfer/electron pair transition absorption peak, which is closely related to the reddish color of the oxide, was shifted to a longer wavelength (blue shift by decreasing the dimension of the particles. The samples were tested as pigments. They showed different tints of red color and were found to be promising for applications as pigments in the field of paint manufacturing.

  4. Effectiveness of cysteine proteases on protein/pigment film removal.

    Science.gov (United States)

    Yao, Jiang-Wu; Xiao, Yin; Zuo, Qi-liang; Zhang, Yi; Tao, Tao; Lin, Chang-Jian

    2013-11-01

    Theaflavin (TF) from the black tea can react to human salivary proline-rich proteins (PRPs) to form stains on exposed dental surfaces. Here, we employed a model of protein/pigment film using TF and dephosphorylated bovine β-casein (Dβ-CN), which has an extended conformation, similar to that of salivary PRPs, on a sensor surface to assess the efficacy of cysteine proteases (CPs) including papain, stem bromelain, and ficin, on removing TF bound to Dβ-CN and the control TF readsorption on the residual substrate surfaces was also measured. The protein/pigment complex film was built by using a quartz crystal microbalance with dissipation (QCM-D). The efficacies of CPs were assessed by Boltzman equation model. The surface details were detected by grazing angle infrared spectroscopy spectra, atomic force microscopy images, and contact angles. The efficacy order of CPs on hydrolyzing protein/pigment complex film is ficin>papain>bromelain. The results from grazing angle infrared spectroscopy spectra, atomic force microscopy images, and contact angles demonstrated that TF bound on the Dβ-CN was effectively removed by the CPs, and the amount of TF readsorption on both the residual film of the Dβ-CN/TF and the Dβ-CN was markedly decreased after hydrolysis. This study indicates the potential application of the CPs for tooth stain removal and suggests that these enzymes are worthy of further investigation for use in oral healthcare. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. In situ UV-vis investigation of growth of gold nanoparticles prepared by solution plasma sputtering in NaCl solution

    Science.gov (United States)

    Mizutani, Tsuyoshi; Ogawa, Satoshi; Murai, Takaaki; Nameki, Hirofumi; Yoshida, Tomoko; Yagi, Shinya

    2015-11-01

    Gold nanoparticles are prepared in various concentrations of NaCl solutions by solution plasma sputtering. The absorption spectra of these solutions during and after the plasma process are measured by in situ ultraviolet-visible (UV-vis) spectroscopy to estimate the particle diameters and concentrations of gold. The distributions of particle diameters are obtained by transmission electron microscope (TEM) observations. These experiments indicate the gold nanoparticles with about 2.2 nm are directly formed by plasma phase and the diameters are increasing over time. These increases of particle diameters are caused by Ostwald ripening of gold nanoparticles in NaCl solution. We estimate the equilibrium diameter at which the gold nanoparticles are not solved in NaCl solution using in situ UV-vis spectroscopy. These diameters are about 5, 7 and 10 nm in 3, 5 and 10 mM NaCl solution, respectively. We make it possible to control the diameter of gold nanoparticles prepared by solution plasma sputtering in NaCl solution.

  6. Vibrational spectroscopic characterisation of salmeterol xinafoate polymorphs and a preliminary investigation of their transformation using simultaneous in situ portable Raman spectroscopy and differential scanning calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Hassan Refat H. [Chemical and Forensic Sciences/University Analytical Centre, School of Life Sciences, University of Bradford, Richmond Road, Bradford BD7 1DP (United Kingdom); Edwards, Howell G.M. [Chemical and Forensic Sciences/University Analytical Centre, School of Life Sciences, University of Bradford, Richmond Road, Bradford BD7 1DP (United Kingdom)], E-mail: H.G.M.Edwards@bradford.ac.uk; Hargreaves, Michael D.; Munshi, Tasnim; Scowen, Ian J.; Telford, Richard J. [Chemical and Forensic Sciences/University Analytical Centre, School of Life Sciences, University of Bradford, Richmond Road, Bradford BD7 1DP (United Kingdom)

    2008-07-14

    Knowledge and control of the polymorphic phases of chemical compounds are important aspects of drug development in the pharmaceutical industry. Salmeterol xinafoate, a long acting {beta}-adrenergic receptor agonist, exists in two polymorphic Forms, I and II. Raman and near infrared spectra were obtained of these polymorphs at selected wavelengths in the range of 488-1064 nm; significant differences in the Raman and near-infrared spectra were apparent and key spectral marker bands have been identified for the vibrational spectroscopic characterisation of the individual polymorphs which were also characterised with X ray diffractometry. The solid-state transition of salmeterol xinafoate polymorphs was studied using simultaneous in situ portable Raman spectroscopy and differential scanning calorimetry isothermally between transitions. This method assisted in the unambiguous characterisation of the two polymorphic forms by providing a simultaneous probe of both the thermal and vibrational data. The study demonstrates the value of a rapid in situ analysis of a drug polymorph which can be of potential value for at-line in-process control.

  7. Investigation of the fabrication processes of AlGaN/AlN/GaN HEMTs with in situ Si{sub 3}N{sub 4} passivation

    Energy Technology Data Exchange (ETDEWEB)

    Tomosh, K. N., E-mail: sky77781@mail.ru; Pavlov, A. Yu.; Pavlov, V. Yu.; Khabibullin, R. A.; Arutyunyan, S. S.; Maltsev, P. P. [Russian Academy of Sciences, Institute of Ultra-High-Frequency Semiconductor Electronics (Russian Federation)

    2016-10-15

    The optimum mode of the in situ plasma-chemical etching of a Si{sub 3}N{sub 4} passivating layer in C{sub 3}F{sub 8}/O{sub 2} medium is chosen for the case of fabricating AlGaN/AlN/GaN HEMTs. It is found that a bias of 40–50 V at a high-frequency electrode provides anisotropic etching of the insulator through a resist mask and introduces no appreciable radiation-induced defects upon overetching of the insulator films in the region of gate-metallization formation. To estimate the effect of in situ Si{sub 3}N{sub 4} growth together with the heterostructure in one process on the AlGaN/AlN/GaN HEMT characteristics, transistors with gates without the insulator and with gates through Si{sub 3}N{sub 4} slits are fabricated. The highest drain current of the AlGaN/AlN/GaN HEMT at 0 V at the gate is shown to be 1.5 times higher in the presence of Si{sub 3}N{sub 4} than without it.

  8. Vibrational spectroscopic characterisation of salmeterol xinafoate polymorphs and a preliminary investigation of their transformation using simultaneous in situ portable Raman spectroscopy and differential scanning calorimetry

    International Nuclear Information System (INIS)

    Ali, Hassan Refat H.; Edwards, Howell G.M.; Hargreaves, Michael D.; Munshi, Tasnim; Scowen, Ian J.; Telford, Richard J.

    2008-01-01

    Knowledge and control of the polymorphic phases of chemical compounds are important aspects of drug development in the pharmaceutical industry. Salmeterol xinafoate, a long acting β-adrenergic receptor agonist, exists in two polymorphic Forms, I and II. Raman and near infrared spectra were obtained of these polymorphs at selected wavelengths in the range of 488-1064 nm; significant differences in the Raman and near-infrared spectra were apparent and key spectral marker bands have been identified for the vibrational spectroscopic characterisation of the individual polymorphs which were also characterised with X ray diffractometry. The solid-state transition of salmeterol xinafoate polymorphs was studied using simultaneous in situ portable Raman spectroscopy and differential scanning calorimetry isothermally between transitions. This method assisted in the unambiguous characterisation of the two polymorphic forms by providing a simultaneous probe of both the thermal and vibrational data. The study demonstrates the value of a rapid in situ analysis of a drug polymorph which can be of potential value for at-line in-process control

  9. In situ investigations on the formation and decomposition of KSiH{sub 3} and CsSiH{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Auer, Henry; Kohlmann, Holger [Department of Inorganic Chemistry, Leipzig University (Germany)

    2017-08-03

    The system KSi-KSiH{sub 3} stores 4.3 wt % of hydrogen and shows a very good reversibility at mild conditions of 0.1 MPa hydrogen pressure and 414 K.[] We followed the reaction pathways of the hydrogenation reactions of KSi and its higher homologue CsSi by in situ methods in order to check for possible intermediate hydrides. In situ diffraction at temperatures up to 500 K and gas pressures up to 5.0 MPa hydrogen gas for X-ray and deuterium gas for neutron reveal that both KSi and CsSi react in one step to the hydrides KSiH{sub 3} and CsSiH{sub 3} and the respective deuterides. Neither do the Zintl phases dissolve hydrogen (deuterium), nor do the hydrides (deuterides) show any signs for non-stoichiometry, i.e. all phases involved in the formation are line phases. Heating to temperatures above 500 K shows that at 5.0 MPa hydrogen pressure only the reaction 2CsSi + 3H{sub 2} = 2CsSiH{sub 3} is reversible. Under these conditions, KSiH{sub 3} decomposes to a clathrate and potassium hydride according to 46KSiH{sub 3} = K{sub 8}Si{sub 46} + 38KH + 50H{sub 2}. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. In situ

    Science.gov (United States)

    Tremsin, Anton S; Makowska, Małgorzata G; Perrodin, Didier; Shalapska, Tetiana; Khodyuk, Ivan V; Trtik, Pavel; Boillat, Pierre; Vogel, Sven C; Losko, Adrian S; Strobl, Markus; Kuhn, L Theil; Bizarri, Gregory A; Bourret-Courchesne, Edith D

    2016-06-01

    Neutrons are known to be unique probes in situations where other types of radiation fail to penetrate samples and their surrounding structures. In this paper it is demonstrated how thermal and cold neutron radiography can provide time-resolved imaging of materials while they are being processed ( e.g. while growing single crystals). The processing equipment, in this case furnaces, and the scintillator materials are opaque to conventional X-ray interrogation techniques. The distribution of the europium activator within a BaBrCl:Eu scintillator (0.1 and 0.5% nominal doping concentrations per mole) is studied in situ during the melting and solidification processes with a temporal resolution of 5-7 s. The strong tendency of the Eu dopant to segregate during the solidification process is observed in repeated cycles, with Eu forming clusters on multiple length scales (only for clusters larger than ∼50 µm, as limited by the resolution of the present experiments). It is also demonstrated that the dopant concentration can be quantified even for very low concentration levels (∼0.1%) in 10 mm thick samples. The interface between the solid and liquid phases can also be imaged, provided there is a sufficient change in concentration of one of the elements with a sufficient neutron attenuation cross section. Tomographic imaging of the BaBrCl:0.1%Eu sample reveals a strong correlation between crystal fractures and Eu-deficient clusters. The results of these experiments demonstrate the unique capabilities of neutron imaging for in situ diagnostics and the optimization of crystal-growth procedures.

  11. Application of high-performance liquid chromatography to the characterization of the betalain pigments in prickly pear fruits.

    Science.gov (United States)

    Fernández-López, J A; Almela, L

    2001-04-13

    The qualitative and quantitative betalain pigment content of two cultivars of prickly pear (Opuntia ficus-indica) fruits grown in southeastern Spain was evaluated. After methanolic extraction of crushed fruits, reversed-phase high-performance liquid chromatography and photodiode array detection were applied simultaneously for the separation, identification and quantification of these pigments. Two main pigments were obtained, which were identified as indicaxanthin (lambda(max) 484 nm) and betanin (lambda(max) 535 nm). Spectrophotometric evaluation of both pigments showed a yield of around 20-30 mg per 100 g of fresh pulp. When the influence of temperature (25 to 90 degrees C) on betacyanin pigment stability was investigated, the results revealed a substantial degree of thermodegradation at temperatures higher than 70 degrees C.

  12. A size-dependent sodium storage mechanism in Li4Ti5O12 investigated by a novel characterization technique combining in situ X-ray diffraction and chemical sodiation.

    Science.gov (United States)

    Yu, Xiqian; Pan, Huilin; Wan, Wang; Ma, Chao; Bai, Jianming; Meng, Qingping; Ehrlich, Steven N; Hu, Yong-Sheng; Yang, Xiao-Qing

    2013-10-09

    A novel characterization technique using the combination of chemical sodiation and synchrotron based in situ X-ray diffraction (XRD) has been detailed illustrated. The power of this novel technique was demonstrated in elucidating the structure evolution of Li4Ti5O12 upon sodium insertion. The sodium insertion behavior into Li4Ti5O12 is strongly size dependent. A solid solution reaction behavior in a wide range has been revealed during sodium insertion into the nanosized Li4Ti5O12 (~44 nm), which is quite different from the well-known two-phase reaction of Li4Ti5O12/Li7Ti5O12 system during lithium insertion, and also has not been fully addressed in the literature so far. On the basis of this in situ experiment, the apparent Na(+) ion diffusion coefficient (DNa+) of Li4Ti5O12 was estimated in the magnitude of 10(-16) cm(2) s(-1), close to the values estimated by electrochemical method, but 5 order of magnitudes smaller than the Li(+) ion diffusion coefficient (D(Li+) ~10(-11) cm(2) s(-1)), indicating a sluggish Na(+) ion diffusion kinetics in Li4Ti5O12 comparing with that of Li(+) ion. Nanosizing the Li4Ti5O12 will be critical to make it a suitable anode material for sodium-ion batteries. The application of this novel in situ chemical sodiation method reported in this work provides a facile way and a new opportunity for in situ structure investigations of various sodium-ion battery materials and other systems.

  13. Retinal pigment epithelial integrity is compromised in the developing albino mouse retina.

    Science.gov (United States)

    Iwai-Takekoshi, Lena; Ramos, Anna; Schaler, Ari; Weinreb, Samuel; Blazeski, Richard; Mason, Carol

    2016-12-15

    In the developing murine eye, melanin synthesis in the retinal pigment epithelium (RPE) coincides with neurogenesis of retinal ganglion cells (RGCs). Disruption of pigmentation in the albino RPE is associated with delayed neurogenesis in the ventrotemporal retina, the source of ipsilateral RGCs, and a reduced ipsilateral RGC projection. To begin to unravel how melanogenesis and the RPE regulate RGC neurogenesis and cell subpopulation specification, we compared the features of albino and pigmented mouse RPE cells during the period of RGC neurogenesis (embryonic day, E, 12.5 to 18.5) when the RPE is closely apposed to developing RGC precursors. At E12.5 and E15.5, although albino and pigmented RPE cells express RPE markers Otx2 and Mitf similarly, albino RPE cells are irregularly shaped and have fewer melanosomes compared with pigmented RPE cells. The adherens junction protein P-cadherin appears loosely distributed within the albino RPE cells rather than tightly localized on the cell membrane, as in pigmented RPE. Connexin 43 (gap junction protein) is expressed in pigmented and albino RPE cells at E13.5 but at E15.5 albino RPE cells have fewer small connexin 43 puncta, and a larger fraction of phosphorylated connexin 43 at serine 368. These results suggest that the lack of pigment in the RPE results in impaired RPE cell integrity and communication via gap junctions between RPE and neural retina during RGC neurogenesis. Our findings should pave the way for further investigation of the role of RPE in regulating RGC development toward achieving proper RGC axon decussation. J. Comp. Neurol. 524:3696-3716, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  14. Pigment colors printing on cotton fabrics by surface coating induced by electron beam and thermal curing

    International Nuclear Information System (INIS)

    El-Naggar, Abdel Wahab M.; Zohdy, Maged H.; Said, Hossam M.; El-Din, Mahmoud S.; Noval, Dalia M.

    2005-01-01

    Cotton fabrics were coated from one surface with different pigment colors incorporated in formulations containing ethylene glycol (EG), methyl methacrylate (MMA) and poly(methyl methacrylate) (PMMA) oligomer as a base material. The coated fabrics were exposed to various doses of accelerated electrons generated from the 1.5 MeV (25 kW) electron beam accelerator machine. In order to find the suitable conditions that afford the highest performance of pigment printing, the effect of irradiation dose and formulation composition on the color strength of the printed fabrics was investigated. The durability of the printed fabrics in terms of color fastness, tensile mechanical, crease resistance and water absorption was also studied. The results of pigment printing by electron beam irradiation was compared with the conventional thermal printing method with the same pigment colors involving the use of pastes containing binder and thickener systems. It was found that cotton fabrics printed with the pigment colors under the effect of electron beam irradiation displayed higher color strength than those fabrics printed by the conventional thermal fixation at equal pigment color ratios. In this regard, the color strength on cotton fabrics printed with the Imperon violet, blue and yellow pigment colors was 85.2, 75.4 and 91.3 in the case of printing with electron beam and 63.5, 46.0 and 50.2 in the case of thermal curing, respectively. The results showed that the pigment printing by electron beam or thermal curing improves the crease recovery and mechanical properties of cotton fabrics and exhibited comparable durability properties in terms of washing, rubbing and handling

  15. Use of red pigment extracted from eggplant (Solanum melongena L.) peels as natural antioxidant and colorant

    International Nuclear Information System (INIS)

    Abdeldaiem, M. H.

    2013-01-01

    The present study was carried out to extract of red pigment from eggplant (Solanum melongena L.) peels by using ethanol ( 70%) acidified with 1.5N HCl ( 85:15 v/v). In addition to study the effect of gamma irradiation at dose levels of 0, 2, 4 and 6 kGy on total phenolic compounds, total antioxidant activity and total anthocyanins of red pigment extracted from eggplant peels and the effect of using non-irradiated pigment as food colorants on the sensory attributes of food items used. The results illustrated that the non-irradiated red pigment extracted from eggplant peel samples had a higher content of total phenolic compounds, total anthocyanins and exhibited high antioxidant activities compared with irradiated samples. Thus, based on these results, the effect ph values ( 1 and 10) and heat treatment ( 50 and 100°C) on color stability and on retention anthocyanins, respectively in samples of non-irradiated red pigment extracted from eggplant peel samples were investigated. Furthermore, the results showed that the concentration of color changes with the values of ph, where he was more concentrated at low values of ph. Also, the results exhibited retain the red pigment extracted from the eggplant peels high concentrations of authenticity after heat treatment at different temperatures and for different periods. Moreover, the results of sensory evaluation obvious that the natural red pigment extracted from eggplant peels could be blended with meat products beef sausage, some fruit juices such as strawberry, red grape and pomegranate to substitute the losses that may occur in the anthocyanins during heat treatments as pasteurization. Therefore, this study suggested that the red pigment extracted from eggplant can be used as natural food additives to increase antioxidant activity and colorant in many foods as an alternative to synthetic dyes that are harmful to health effects.

  16. Iris pigment epithelial cysts in a newborn

    Directory of Open Access Journals (Sweden)

    Zargar, Shabnam

    2016-04-01

    Full Text Available Purpose: We report a case of iris pigment epithelial cysts in a newborn and discuss the importance of an accurate diagnosis for prevention of amblyopia.Methods: We describe a case of an abnormal red reflex seen on a newborn exam.Results: A full-term female born via normal spontaneous vaginal delivery without any complications was seen in the newborn nursery. She was noted to have an abnormal eye exam. Pupils were large with circular dark excrescences of the iris pigment epithelium. She was referred to a pediatric ophthalmologist where she was noted to fixate and follow faces. No afferent pupillary defect was seen. OD red reflex was normal whereas OS red reflex was blocked mostly by dark excrescences. A 2– dark brown lesion was seen in the OD iris and a 3–5 mm dark brown lesion was seen in the OS iris, consistent with a pupillary iris pigment epithelial cyst. Central visual axis was clear OU. Glaucoma was not present and patching was not performed. Observations and clinical photographs were recommended with follow-up in three months.Conclusion: Iris pigment epithelial cysts are uncommonly seen in children. The primary care provider first seeing a newborn must be aware of lesions obscuring a red reflex with appropriate follow-up. Follow-up in three months with IOP measurements is recommended. Iris pigment epithelial cysts in children may be a cause of amblyopia, thus prompt evaluation is important for prognostic purposes and the prevention of amblyopia.

  17. Inadvertent polychlorinated biphenyls in commercial paint pigments.

    Science.gov (United States)

    Hu, Dingfei; Hornbuckle, Keri C

    2010-04-15

    A polychlorinated biphenyl (PCB) that was not produced as part of the Aroclor mixtures banned in the 1980s was recently reported in air samples collected in Chicago, Philadelphia, the Arctic, and several sites around the Great Lakes. In Chicago, the congener 3,3'-dichlorobiphenyl or PCB11 was found to be the fifth most concentrated congener and ubiquitous throughout the city. The congener exhibited strong seasonal concentration trends that suggest volatilization of this compound from common outdoor surfaces. Due to these findings and also the compound's presence in waters that received waste from paint manufacturing facilities, we hypothesized that PCB11 may be present in current commercial paint. In this study we measured PCBs in paint sold on the current retail market. We tested 33 commercial paint pigments purchased from three local paint stores. The pigment samples were analyzed for all 209 PCB congeners using gas chromatography with tandem mass spectrometry (GC-MS/MS). More than 50 PCB congeners including several dioxin-like PCBs were detected, and the PCB profiles varied due to different types of pigments and different manufacturing processes. PCB congeners were detected in azo and phthalocyanine pigments which are commonly used in paint but also in inks, textiles, paper, cosmetics, leather, plastics, food and other materials. Our findings suggest several possible mechanisms for the inadvertent production of specific PCB congeners during the manufacturing of paint pigments.

  18. Fish pigmentation and the melanocortin system.

    Science.gov (United States)

    Cal, Laura; Suarez-Bregua, Paula; Cerdá-Reverter, José Miguel; Braasch, Ingo; Rotllant, Josep

    2017-09-01

    The melanocortin system is a complex neuroendocrine signaling mechanism involved in numerous physiological processes in vertebrates, including pigmentation, steroidogenesis and metabolic control. This review focuses at one of its most fascinating function in fish, its regulatory role in the control of pigmentation, in which the melanocortin 1 receptor (Mc1r), its agonist α-melanocyte stimulating hormone (α-Msh), and the endogenous antagonist agouti signaling protein (Asip1) are the main players. Functional control of Mc1r, which is highly expressed in fish skin and whose activation stimulates melanin production and melanosome dispersion in fish melanophores, is considered a key mechanism for vertebrate pigment phenotypes. The α-Msh peptide, the most documented Mc1r agonist involved in pigmentation, is produced in the pituitary gland, activating melanin synthesis by binding to Mc1r in fish melanophores. Finally, Asip1 is the putative factor for establishing the evolutionarily conserved dorso-ventral pigment pattern found across vertebrates. However, we are just starting to understand how other melanocortin system components are acting in this complex regulatory network. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Synchrotron powder diffraction on Aztec blue pigments

    International Nuclear Information System (INIS)

    Sanchez del Rio, M.; Gutierrez-Leon, A.; Castro, G.R.; Rubio-Zuazo, J.; Solis, C.; Sanchez-Hernandez, R.; Robles-Camacho, J.; Rojas-Gaytan, J.

    2008-01-01

    Some samples of raw blue pigments coming from an archaeological rescue mission in downtown Mexico City have been characterized using different techniques. The samples, some recovered as a part of a ritual offering, could be assigned to the late Aztec period (XVth century). The striking characteristic of these samples is that they seem to be raw pigments prior to any use in artworks, and it was possible to collect a few μg of pigment after manual grain selection under a microscopy monitoring. All pigments are made of indigo, an organic colorant locally known as anil or xiuhquilitl. The colorant is always found in combination with an inorganic matrix, studied by powder diffraction. In one case the mineral base is palygorskite, a rare clay mineral featuring micro-channels in its structure, well known as the main ingredient of the Maya blue pigment. However, other samples present the minerals sepiolite (a clay mineral of the palygorskite family) and calcite. Another sample contains barite, a mineral never reported in prehispanic paints. We present the results of characterization using high resolution powder diffraction recorded at the European Synchrotron Radiation Facility (BM25A, SpLine beamline) complemented with other techniques. All of them gave consistent results on the composition. A chemical test on resistance to acids was done, showing a high resistance for the palygorskite and eventually sepiolite compounds, in good agreement with the excellent resistance of the Maya blue. (orig.)

  20. Effect of strain on space charge layer in GaN nanowires investigated by in-situ off-axis electron holography

    Directory of Open Access Journals (Sweden)

    Xiao Chen

    2017-04-01

    Full Text Available Effect of strain on space charge (SC layer in nanowires (NWs has been examined by in situ off-axis electron holography, where GaN NWs attach to an Au electrode inside a transmission electron microscope (TEM. Based on the phase image reconstructed from the complex hologram, the width of SC layer in a strained GaN NW is significantly reduced to about 60 nm, comparing to the 85 nm of the unstrained NW. About 29% reduction of the SC layer in the strained GaN NW resulted from significant decrease of electrons flowed from the GaN into Au. First principle calculations show that the strain reduced bandgap of GaN, narrowing the difference between GaN NW and Au electrode in Fermi level.

  1. Investigations on in situ diagnostics by an infrared camera to distinguish between the plasma facing tiles with carbonaceous surface layer and defect in the underneath junction

    International Nuclear Information System (INIS)

    Cai, Laizhong; Gauthier, Eric; Corre, Yann; Liu, Jian

    2013-01-01

    Both a deposition surface layer and a delamination underneath junction existing on plasma facing components (PFCs) can result in abnormal high surface temperature under normal heating conditions. The tile with delamination has to be replaced to prevent from a critical failure (complete delamination) during plasma operation while the carbon deposit can be removed without any repairing. Therefore, distinguishing in situ deposited tiles and junction defect tiles is crucial to avoid the critical failure without unwanted shutdown. In this paper, the thermal behaviors of junction defect tiles and carbon deposit tiles are simulated numerically. A modified time constant method is then introduced to analyze the thermal behaviors of deposited tiles and junction defect tiles. The feasibility of discrimination by analyzing the thermal behaviors of tiles is discussed and the requirements of this method for discrimination are described. Finally, the time resolution requirement of IR cameras to do the discrimination is mentioned

  2. Investigation of the Effect of Tungsten Substitution on Microstructure and Abrasive Wear Performance of In Situ VC-Reinforced High-Manganese Austenitic Steel Matrix Composite

    Science.gov (United States)

    Moghaddam, Emad Galin; Karimzadeh, Neda; Varahram, Naser; Davami, Parviz

    2013-08-01

    Particulate VC-reinforced high-manganese austenitic steel matrix composites with different vanadium and tungsten contents were synthesized by conventional alloying and casting route. Microstructural characterizations showed that the composites processed by in situ precipitation of the reinforcements were composed of V8C7 particulates distributed in an austenitic matrix. It was observed that addition of tungsten to austenite increases work-hardening rate of subsurface layer during pin-on disk wear test. The maximum abrasive wear resistance was achieved at tungsten content equal to 2 wt pct. However, excessive addition of tungsten promoted the formation of W3C phase and reduced the abrasive wear resistance because of decrease in distribution homogeneity and volume fraction of the reinforcing VC particles.

  3. Growth and structure of water on SiO2 films on Si investigated byKelvin probe microscopy and in situ X-ray Spectroscopies

    Energy Technology Data Exchange (ETDEWEB)

    Verdaguer, A.; Weis, C.; Oncins, G.; Ketteler, G.; Bluhm, H.; Salmeron, M.

    2007-06-14

    The growth of water on thin SiO{sub 2} films on Si wafers at vapor pressures between 1.5 and 4 torr and temperatures between -10 and 21 C has been studied in situ using Kelvin Probe Microscopy and X-ray photoemission and absorption spectroscopies. From 0 to 75% relative humidity (RH) water adsorbs forming a uniform film 4-5 layers thick. The surface potential increases in that RH range by about 400 mV and remains constant upon further increase of the RH. Above 75% RH the water film grows rapidly, reaching 6-7 monolayers at around 90% RH and forming a macroscopic drop near 100%. The O K-edge near-edge X-ray absorption spectrum around 75% RH is similar to that of liquid water (imperfect H-bonding coordination) at temperatures above 0 C and ice-like below 0 C.

  4. Investigation of the mechanical behaviour of gas-hydrate bearing clayey sediments from the Gulf of Guinea using in-situ geotechnical measurements

    Science.gov (United States)

    Taleb, F.; Garziglia, S.; Sultan, N.

    2017-12-01

    Expanding needs for energy resources and concerns about climate change have moved industrial and academic interests towards regions where specific thermobaric conditions allow the formation of gas hydrates (GH). While significant advances have been made to characterize the fabric and structure of these metastable geo-compounds, considerable uncertainty remains regarding the impact of their mechanical properties on the seafloor morphology and stability. This is particularly true for gas hydrates-bearing fine-grained sediments, which remain challenging to preserve or synthesise prior to laboratory testing. As a step towards understanding the mechanical consequences of the concentration and distribution of GH in this type of sediments, this work uses acoustic and geotechnical in situ measurements collected in a high gas flux system offshore Nigeria. Acoustic measurements of compressional wave velocity were shown to be convenient means of both detecting and quantifying gas hydrates in marine sediments. Geotechnical data derived from piezocone readings and their distribution in normalised soil classification charts allowed identifying distinct features of gas hydrates-bearing clayey sediments; such as a mechanical behaviour sharing similarities with that of cemented clays. Correlations between acoustic and piezocone data showed that the stiffness and strength tend to generally increase with increasing GH concentrations. However, several sediment intervals sharing the same hydrates concentration have revealed different features of mechanical behaviour. This was linked to the presence of various GH morphologies within the marine sediments such as groups of hydrate veins or massive hydrate nodules. This in-situ approach allowing both understanding the heterogeneous distribution of GH and characterising their host sediment seems key to assess the potential link between seafloor stability and GH dissociation/dissolution caused by human activities or by natural environmental

  5. Investigation of electron behavior in Nano-TiO2 photocatalysis by using in situ open-circuit voltage and photoconductivity measurements.

    Science.gov (United States)

    Liu, Baoshun; Wang, Xuelei; Wen, Liping; Zhao, Xiujian

    2013-08-05

    The in situ open-circuit voltages (Voc ) and the in situ photoconductivities have been measured to study electron behavior in photocatalysis and its effect on the photocatalytic oxidation of methanol. It was observed that electron injection to the conduction band (CB) of TiO2 under light illumination during photocatalysis includes two sources: from the valence band (VB) of TiO2 and from the methanol molecule. The electron injection from methanol to TiO2 is slower than that directly from the VB, which indicates that the adsorption mode of methanol on the TiO2 surface can change between dark and illuminated states. The electron injection from methanol to the CB of TiO2 leads to the upshift of the Fermi level of electrons in TiO2 , which is the thermodynamic driving force of photocatalytic oxidation. It was also found that the charge state of nano-TiO2 is continuously changing during photocatalysis as electrons are injected from methanol to TiO2 . Combined with the apparent Langmuir-Hinshelwood kinetic model, the relation between photocatalytic kinetics and electrons in the TiO2 CB was developed and verified experimentally. The photocatalytic rate constant is the variation of the Fermi level with time, based on which a new method was developed to calculate the photocatalytic kinetic rate constant by monitoring the change of Voc with time during photocatalysis. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Investigation of in situ gelling alginate formulations as a sustained release vehicle for co-precipitates of dextromethrophan and Eudragit S 100

    Directory of Open Access Journals (Sweden)

    Maghraby Gamal Mohamed El

    2014-03-01

    Full Text Available Alginate vehicles are capable of forming a gel matrix in situ when they come into contact with gastric medium in the presence of calcium ions. However, the gel structure is pH dependent and can break after gastric emptying, leading to dose dumping. The aim of this work was to develop modified in situ gelling alginate formulations capable of sustaining dextromethorphan release throughout the gastrointestinal tract. Alginate solution (2 %, m/m was used as a vehicle for the tested formulations. Solid matrix of the drug and Eudragit S 100 was prepared by dissolving the drug and polymer in acetone. The organic solvent was then evaporated and the deposited solid matrix was micronized, sieved and dispersed in alginate solution to obtain candidate formulations. The release behavior of dextromethorphan was monitored and evaluated in a medium simulating the gastric and intestinal pH. Drug-polymer compatibility and possible solid-state interactions suggested physical interaction through hydrogen bonding between the drug and the polymer. A significant decrease in the rate and extent of dextromethorphan release was observed with increasing Eudragit S 100 concentration in the prepared particles. Most formulations showed sustained release profiles similar to that of a commercial sustained-release liquid based on ion exchange resin. The release pattern indicated strict control of drug release both under gastric and intestinal conditions, suggesting the potential advantage of using a solid dispersion of drug-Eudragit S 100 to overcome the problem of dose dumping after the rupture of the pH dependent alginate gels

  7. In situ Raman spectroscopic study of marble capitals in the Alhambra monumental ensemble

    Science.gov (United States)

    Arjonilla, Paz; Domínguez-Vidal, Ana; de la Torre López, María José; Rubio-Domene, Ramón; Ayora-Cañada, María José

    2016-12-01

    The marble capitals of five different sites in the Alhambra complex (Granada, Spain), namely the Mexuar, the Hall of the Abencerrages, the Hall of the Kings, the Court of the Myrtles and the Court of the Main Canal, have been investigated. The decoration of the capitals exhibits mainly blue, red, black and gilding motifs with different states of conservation. The work has been carried out in situ by means of a portable Raman micro-spectrometer with an excitation laser of 785 nm. In addition to preserving the artwork with a non-invasive study, the on-site investigation gives a more representative knowledge of the art objects because the measurements are not limited to the samples that can be taken (few and small). The obtained Raman spectra were of good quality despite challenging adverse conditions out of the laboratory. Cinnabar, minium, carbon black, natural lapis lazuli and azurite were the main pigments found. Synthetic ultramarine blue was also detected in a capital as a result of a modern restoration. Degradation products as tin oxide in the gildings and weddellite in the preparation layers were also identified. All the results together with a careful visual inspection can be combined to elucidate the different execution techniques employed to apply the pigments on the marble substrate of the capitals in the Nasrid and Christian periods.

  8. Effects of iron availability on pigment signature and biogenic silica production in the coastal diatom Chaetoceros gracilis

    Digital Repository Service at National Institute of Oceanography (India)

    Biswas, H.; Bandyopadhyay, D.

    The effects of iron availability on pigment signature and biogenic silica production were investigated for the first time in the coastal diatom Chaetoceros gracilis (isolated from the SW coast of the Bay of Bengal, India). Results revealed...

  9. Platelet-Rich Plasma Increases Pigmentation.

    Science.gov (United States)

    Uysal, Cagri A; Ertas, Nilgun Markal

    2017-11-01

    Platelet-rich plasma (PRP) is an autologous solution of plasma containing 4 to 7 times the baseline concentration of human platelets. Platelet-rich plasma has been widely popular in facial rejuvenation to attenuate wrinkles and has been practically used. The authors have been encountering various patients of increased hiperpigmentation following PRP applications that were performed to attenuate the postinflammatory hiperpigmentation especially after laser treatment. The authors have been using PRP for facial rejuvenation in selected patients and in 1 patient the authors have encountered increased pigmentation over the pigmented skin lesions that were present before the application. The authors recommend that the PRP might increase pigmentation especially in the face region and precautions might be taken before and after the application. Platelet-rich plasma should not be used for the treatment of post inflammatory hiperpigmentation.

  10. Nanomechanical analysis of pigmented human melanoma cells.

    Science.gov (United States)

    Sarna, Michal; Zadlo, Andrzej; Pilat, Anna; Olchawa, Magdalena; Gkogkolou, Paraskevi; Burda, Kvetoslava; Böhm, Markus; Sarna, Tadeusz

    2013-09-01

    Based on hitherto measurements of elasticity of various cells in vitro and ex vivo, cancer cells are generally believed to be much softer than their normal counterparts. In spite of significant research efforts on the elasticity of cancer cells, only few studies were undertaken with melanoma cells. However, there are no reports concerning pigmented melanoma cells. Here, we report for the first time on the elasticity of pigmented human melanoma cells. The obtained data show that melanin significantly increases the stiffness of pigmented melanoma cells and that the effect depends on the amount of melanin inside the cells. The dramatic impact of melanin on the nanomechanical properties of cells puts into question widely accepted paradigm about all cancer cells being softer than their normal counterparts. Our findings reveal significant limitations of the nanodiagnosis approach for melanoma and contribute to better understanding of cell elasticity. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Pigments which reflect infrared radiation from fire

    Science.gov (United States)

    Berdahl, Paul H.

    1998-01-01

    Conventional paints transmit or absorb most of the intense infrared (IR) radiation emitted by fire, causing them to contribute to the spread of fire. The present invention comprises a fire retardant paint additive that reflects the thermal IR radiation emitted by fire in the 1 to 20 micrometer (.mu.m) wavelength range. The important spectral ranges for fire control are typically about 1 to about 8 .mu.m or, for cool smoky fires, about 2 .mu.m to about 16 .mu.m. The improved inventive coatings reflect adverse electromagnetic energy and slow the spread of fire. Specific IR reflective pigments include titanium dioxide (rutile) and red iron oxide pigments with diameters of about 1 .mu.m to about 2 .mu.m and thin leafing aluminum flake pigments.

  12. An intracellular anion channel critical for pigmentation.

    Science.gov (United States)

    Bellono, Nicholas W; Escobar, Iliana E; Lefkovith, Ariel J; Marks, Michael S; Oancea, Elena

    2014-12-16

    Intracellular ion channels are essential regulators of organellar and cellular function, yet the molecular identity and physiological role of many of these channels remains elusive. In particular, no ion channel has been characterized in melanosomes, organelles that produce and store the major mammalian pigment melanin. Defects in melanosome function cause albinism, characterized by vision and pigmentation deficits, impaired retinal development, and increased susceptibility to skin and eye cancers. The most common form of albinism is caused by mutations in oculocutaneous albinism II (OCA2), a melanosome-specific transmembrane protein with unknown function. Here we used direct patch-clamp of skin and eye melanosomes to identify a novel chloride-selective anion conductance mediated by OCA2 and required for melanin production. Expression of OCA2 increases organelle pH, suggesting that the chloride channel might regulate melanin synthesis by modulating melanosome pH. Thus, a melanosomal anion channel that requires OCA2 is essential for skin and eye pigmentation.

  13. Gingival pigmentation beneath a metallic crown

    International Nuclear Information System (INIS)

    Sakai, T.; Hirayasu, R.; Sakai, H.; Hashimoto, N.

    1988-01-01

    Light and electron microscopic studies and energy dispersive X-ray analysis disclosed that the essential cause of gingival discoloration following the placement of a metallic crown, was marked deposition of melanin pigment. Deposition of melanin pigment was observed in epithelial cells, on basement membranes, and in fibroblasts, macrophages and among intercellular ground substance of the proprial layer. Brown or dark brown colored granules were observed in the deep portion of the proprial layer. Some metallic elements as silver and sulfur were detected. It was presumed that these materials were dental metals accidentally implanted in gingival tissues during the therapeutic procedure. The deposition of melanin pigment closely corresponded with mucosal tissue where these materials were present in the deep portion of the proprial layer. These findings suggested that these materials influenced the physiological metabolism of melanin and induced its pathological deposition in the proprial tissue. (author)

  14. Effects of ozone on plant pigments

    Energy Technology Data Exchange (ETDEWEB)

    Nouchi, I.; Odaira, T.

    1974-01-01

    The effects of ozone on plants were studied, with emphasis on leaf bleaching, chlorosis, and appearance of reddish flecks on leaves. Leaves were analyzed with emphasis on ozone-induced destruction of chlorophyll and the formation of red anthrocyanin pigments. Leaves were exposed to 20 pphm to O/sub 3/. Pigments in Brassica pekinensis, morning glory, Zelkova serrata, and Prunus yedonensis were analyzed. Exposure to O/sub 3/ decreased the amount of chlorophyll, lowered the ratio of chlorophyll a to chlorophyll b, and caused anthrocyanin to form. From these results and from symptoms of O/sub 3/ injury to broad leaves (such as early appearance of yellow or red pigments in the leaves and premature fall of leaves), and published microscopic observations of chloroplast, it was deduced that O/sub 3/ accelerated the senescence of leaves and of the plant itself. 15 references.

  15. UV-B affects the immune system and promotes nuclear abnormalities in pigmented and non-pigmented bullfrog tadpoles.

    Science.gov (United States)

    Franco-Belussi, Lilian; Fanali, Lara Zácari; De Oliveira, Classius

    2018-03-01

    Ultra-Violet (UV) radiation is a stressor of the immune system and causes DNA damage. Leukocytes can change in response to environmental changes in anurans, making them an important biomarker of stressful situations. The initial barrier against UV in ectothermic animals is melanin-containing cells in skin and in their internal organs. Here, we tested the effects of UV exposure on immune cells and DNA integrity in pigmented and non-pigmented tadpoles of Lithobates catesbeianus. We used an inflammation model with lipopolysaccharide (LPS) of Escherichia coli to test synergic effects of UV and LPS. We tested the following hypotheses: 1) DNA damage caused by UV will be more pronounced in non-pigmented than in pigmented animals; 2) LPS increases leukocytes in both pigmented and non-pigmented animals by systemic inflammation; 3) The combined LPS and UV exposure will decrease the number of leukocytes. We found that the frequency of immune cells differed between pigmented and non-pigmented tadpoles. UV exposure increased mast cells and DNA damage in erythrocytes in both pigmented and non-pigmented tadpoles, while leukocytes decreased after UV exposure. Non-pigmented tadpoles experienced DNA damage and a lower lymphocyte count earlier than pigmented tadpoles. UV altered immune cells likely as a consequence of local and systemic inflammation. These alterations were less severe in pigmented than in non-pigmented animals. UV and LPS increased internal melanin in pigmented tadpoles, which were correlated with DNA damage and leukocytes. Here, we described for the first time the effects of UV and LPS in immune cells of pigmented and non-pigmented tadpoles. In addition, we demonstrated that internal melanin in tadpoles help in these defenses, since leukocyte responses were faster in non-pigmented animals, supporting the hypothesis that melanin is involved in the initial innate immune response. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Pseudoepitheliomatous Hyperplasia in a Red Pigment Tattoo

    Science.gov (United States)

    Kazlouskaya, Viktoryia

    2015-01-01

    Red pigment tattoos are known to cause pseudoepitheliomatous hyperplasia in the skin, frequently simulating squamous cell carcinoma or keratoacanthoma. Herein, the authors present two additional cases of red pigment tattoo pseudoepitheliomatous hyperplasia in which they noted a lichenoid tissue reaction. They reviewed the previously published cases and observed a lichenoid reaction in the histopathological images similar to hypertrophic lichen planus. The authors suggest that these reactions might best be referred to as “lichenoid reaction with pseudoepitheliomatous hyperplasia” or “hypertrophic lichen planus-like reaction.” Accordingly, recognition of an inflammatory component may allow additional treatment options. PMID:26705448

  17. RISK ASSESSMENT FOR THE DYE AND PIGMENT ...

    Science.gov (United States)

    This risk assessment calculates the maximum loadings of constituents found in dyes and pigment industries waste streams which can be disposed in different types of waste management units without causing health benchmarks to be exceeded at plausible receptor locations. The assessment focuses on potential risks from volatilization and leaching to groundwater of constituents disposed in surface impoundments and landfills with either clay liners or composite liners. This product will be used by EPA decision makers to assist in determining whether certain waste streams generated by the dyes and pigments industries should be designated as hazardous.

  18. In situ non-invasive EDXRF analysis to reconstruct stratigraphy and thickness of Renaissance pictorial multilayers

    International Nuclear Information System (INIS)

    Bonizzoni, L.; Poldi, G.; Milazzo, M.; Galli, A.

    2007-01-01

    In this paper, we report a few examples showing how energy dispersive XRF analysis (EDXRF) coupled with visible reflectance spectroscopy (vis-RS) can be successfully applied for the investigation of wood or canvas paintings by performing stratigraphic analyses with non-invasive techniques. The specific aim is to reconstruct layers and their thicknesses. The method has been tested in the laboratory on paint layers similar to traditional Renaissance ones. In situ analyses of a famous wood painting by Andrea Mantegna - 'Madonna col bambino e un coro di cherubini', Pinacoteca di Brera, Milan - were also carried out. While illustrating the results concerning the identification of pigments and the discrimination of layer stratigraphy, advantages and limitation of this method are pointed out. (authors)

  19. In situ non-invasive EDXRF analysis to reconstruct stratigraphy and thickness of Renaissance pictorial multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Bonizzoni, L.; Poldi, G.; Milazzo, M. [Istituto di Fisica Generale Applicata, Universita' degli Studi di Milano, via Celoria 16, 20133 Milano (Italy); Galli, A. [CNR-INFM, Dipartimento di Scienza dei Materiali, Universita' degli Studi di Milano-Bicocca, via R. Cozzi 53, 20125 Milano (Italy)

    2007-03-15

    In this paper, we report a few examples showing how energy dispersive XRF analysis (EDXRF) coupled with visible reflectance spectroscopy (vis-RS) can be successfully applied for the investigation of wood or canvas paintings by performing stratigraphic analyses with non-invasive techniques. The specific aim is to reconstruct layers and their thicknesses. The method has been tested in the laboratory on paint layers similar to traditional Renaissance ones. In situ analyses of a famous wood painting by Andrea Mantegna - 'Madonna col bambino e un coro di cherubini', Pinacoteca di Brera, Milan - were also carried out. While illustrating the results concerning the identification of pigments and the discrimination of layer stratigraphy, advantages and limitation of this method are pointed out. (authors)

  20. Ethnic and mouse strain differences in central corneal thickness and association with pigmentation phenotype.

    Directory of Open Access Journals (Sweden)

    David P Dimasi

    Full Text Available The cornea is a transparent structure that permits the refraction of light into the eye. Evidence from a range of studies indicates that central corneal thickness (CCT is strongly genetically determined. Support for a genetic component comes from data showing significant variation in CCT between different human ethnic groups. Interestingly, these studies also appear to show that skin pigmentation may influence CCT. To validate these observations, we undertook the first analysis of CCT in an oculocutaneous albinism (OCA and Ugandan cohort, populations with distinct skin pigmentation phenotypes. There was a significant difference in the mean CCT of the OCA, Ugandan and Australian-Caucasian cohorts (Ugandan: 517.3±37 µm; Caucasian: 539.7±32.8 µm, OCA: 563.3±37.2 µm; p<0.001. A meta-analysis of 53 studies investigating the CCT of different ethnic groups was then performed and demonstrated that darker skin pigmentation is associated with a thinner CCT (p<0.001. To further verify these observations, we measured CCT in 13 different inbred mouse strains and found a significant difference between the albino and pigmented strains (p = 0.008. Specific mutations within the melanin synthesis pathway were then investigated in mice for an association with CCT. Significant differences between mutant and wild type strains were seen with the nonagouti (p<0.001, myosin VA (p<0.001, tyrosinase (p = 0.025 and tyrosinase related protein (p = 0.001 genes. These findings provide support for our hypothesis that pigmentation is associated with CCT and identifies pigment-related genes as candidates for developmental determination of a non-pigmented structure.

  1. Macular pigment optical density measurements: evaluation of a device using heterochromatic flicker photometry

    NARCIS (Netherlands)

    de Kinkelder, R.; van der Veen, R. L. P.; Verbaak, F. D.; Faber, D. J.; van Leeuwen, T. G.; Berendschot, T. T. J. M.

    2011-01-01

    Purpose Accurate assessment of the amount of macular pigment (MPOD) is necessary to investigate the role of carotenoids and their assumed protective functions. High repeatability and reliability are important to monitor patients in studies investigating the influence of diet and supplements on MPOD.

  2. Multiple pigment cell types contribute to the black, blue, and orange ornaments of male guppies (Poecilia reticulata.

    Directory of Open Access Journals (Sweden)

    Verena A Kottler

    Full Text Available The fitness of male guppies (Poecilia reticulata highly depends on the size and number of their black, blue, and orange ornaments. Recently, progress has been made regarding the genetic mechanisms underlying male guppy pigment pattern formation, but we still know little about the pigment cell organization within these ornaments. Here, we investigate the pigment cell distribution within the black, blue, and orange trunk spots and selected fin color patterns of guppy males from three genetically divergent strains using transmission electron microscopy. We identified three types of pigment cells and found that at least two of these contribute to each color trait. Further, two pigment cell layers, one in the dermis and the other in the hypodermis, contribute to each trunk spot. The pigment cell organization within the black and orange trunk spots was similar between strains. The presence of iridophores in each of the investigated color traits is consistent with a key role for this pigment cell type in guppy color pattern formation.

  3. Enhanced production of natural yellow pigments from Monascus purpureus by liquid culture: The relationship between fermentation conditions and mycelial morphology.

    Science.gov (United States)

    Lv, Jun; Zhang, Bo-Bo; Liu, Xiao-Dong; Zhang, Chan; Chen, Lei; Xu, Gan-Rong; Cheung, Peter Chi Keung

    2017-10-01

    Natural yellow pigments produced by submerged fermentation of Monascus purpureus have potential economic value and application in the food industry. In the present study, the relationships among fermentation conditions (in terms of pH and shaking/agitation speed), mycelial morphology and the production of Monascus yellow pigments were investigated in both shake-flask and scale-up bioreactor experiments. In the shake-flask fermentation, the highest yield of the Monascus yellow pigments was obtained at pH 5.0 and a shaking speed of 180 rpm. Microscopic images revealed that these results were associated with the formation of freely dispersed small mycelial pellets with shorter, thicker and multi-branched hyphae. Further investigation indicated that the hyphal diameter was highly correlated with the biosynthesis of the Monascus yellow pigments. In a scaled-up fermentation experiment, the yield of yellow pigments (401 U) was obtained in a 200-L bioreactor, which is the highest yield to the best of our knowledge. The present findings can advance our knowledge on the conditions used for enhancing the production of Monascus yellow pigments in submerged fermentation and facilitate large-scale production of these natural pigments. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  4. In situ TEM investigation of congruent phase transition and structural evolution of nanostructured silicon/carbon anode for lithium ion batteries.

    Science.gov (United States)

    Wang, Chong-Min; Li, Xiaolin; Wang, Zhiguo; Xu, Wu; Liu, Jun; Gao, Fei; Kovarik, Libor; Zhang, Ji-Guang; Howe, Jane; Burton, David J; Liu, Zhongyi; Xiao, Xingcheng; Thevuthasan, Suntharampillai; Baer, Donald R

    2012-03-14

    It is well-known that upon lithiation, both crystalline and amorphous Si transform to an armorphous Li(x)Si phase, which subsequently crystallizes to a (Li, Si) crystalline compound, either Li(15)Si(4) or Li(22)Si(5). Presently, the detailed atomistic mechanism of this phase transformation and the degradation process in nanostructured Si are not fully understood. Here, we report the phase transformation characteristic and microstructural evolution of a specially designed amorphous silicon (a-Si) coated carbon nanofiber (CNF) composite during the charge/discharge process using in situ transmission electron microscopy and density function theory molecular dynamic calculation. We found the crystallization of Li(15)Si(4) from amorphous Li(x)Si is a spontaneous, congruent phase transition process without phase separation or large-scale atomic motion, which is drastically different from what is expected from a classic nucleation and growth process. The a-Si layer is strongly bonded to the CNF and no spallation or cracking is observed during the early stages of cyclic charge/discharge. Reversible volume expansion/contraction upon charge/discharge is fully accommodated along the radial direction. However, with progressive cycling, damage in the form of surface roughness was gradually accumulated on the coating layer, which is believed to be the mechanism for the eventual capacity fade of the composite anode during long-term charge/discharge cycling. © 2012 American Chemical Society

  5. A novel molten-salt electrochemical cell for investigating the reduction of uranium dioxide to uranium metal by lithium using in situ synchrotron radiation.

    Science.gov (United States)

    Brown, Leon D; Abdulaziz, Rema; Jervis, Rhodri; Bharath, Vidal; Mason, Thomas J; Atwood, Robert C; Reinhard, Christina; Connor, Leigh D; Inman, Douglas; Brett, Daniel J L; Shearing, Paul R

    2017-03-01

    A novel electrochemical cell has been designed and built to allow for in situ energy-dispersive X-ray diffraction measurements to be made during reduction of UO 2 to U metal in LiCl-KCl at 500°C. The electrochemical cell contains a recessed well at the bottom of the cell into which the working electrode sits, reducing the beam path for the X-rays through the molten-salt and maximizing the signal-to-noise ratio from the sample. Lithium metal was electrodeposited onto the UO 2 working electrode by exposing the working electrode to more negative potentials than the Li deposition potential of the LiCl-KCl eutectic electrolyte. The Li metal acts as a reducing agent for the chemical reduction of UO 2 to U, which appears to proceed to completion. All phases were fitted using Le Bail refinement. The cell is expected to be widely applicable to many studies involving molten-salt systems.

  6. Investigating drug absorption from the colon: Single-pass vs. Doluisio approaches to in-situ rat large-intestinal perfusion.

    Science.gov (United States)

    Lozoya-Agullo, Isabel; Zur, Moran; Fine-Shamir, Noa; Markovic, Milica; Cohen, Yael; Porat, Daniel; González-Álvarez, Isabel; González-Álvarez, Marta; Merino-Sanjuán, Matilde; Bermejo, Marival; Dahan, Arik

    2017-07-15

    Traditionally, the colon is considered a secondary intestinal segment in the drug absorption process. However, in many cases the role of colonic drug permeability cannot be overlooked. The purpose of this research was to compare colon permeability data obtained using two different rat perfusion methods the single-pass intestinal perfusion (SPIP) approach and the closed-loop (Doluisio) perfusion model. A list of 14 structurally diverse model drugs was constructed, and their rat colon permeability was studied using the two methods. The two sets of results were compared to each other, and were evaluated vs. in-vitro, ex-vivo, and in-vivo literature values. The SPIP and the Doluisio results exhibited good correlation between them (R 2 =0.81). The best correlation of both sets was obtained with transport studies across Caco-2 monolayers (R 2 ∼0.9), as well as the sigmoidal fit vs. human fraction of dose absorbed (F abs ) data. On the other hand, Ussing chambers data, as well as lipophilicity (Log P) data, resulted in weak correlation to the in-situ results. In conclusion, the single-pass intestinal perfusion (SPIP) and the Doluisio (closed-loop) perfusion models were found to be equally convenient and useful for obtaining validated colon permeability values, although more human colonic F abs data are needed for a better understanding of colonic drug permeability and absorption. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Investigation of Surface Alkylation Strategy in SOMC: In Situ Generation of a Silica-Supported Tungsten Methyl Catalyst for Cyclooctane Metathesis

    KAUST Repository

    Hamieh, Ali Imad Ali

    2016-07-28

    An efficient and potentially scalable method is described for the synthesis of the silica-supported complexes [(≡Si-O-)WMe5] and [(≡Si-O-)WMe2(≡CH)] obtained by in situ alkylation of the surface-grafted tungsten chloride [(≡Si-O-)WCl5] (1). [(≡Si-O-)WCl5] can be readily prepared by the reaction of commercially available and stable tungsten hexachloride WCl6 with partially dehydroxylated silica at 700 °C (SiO2-700). Further reaction with ZnMe2 at room temperature rapidly forms a mixture of surface-alkylated tungsten complexes. They were fully characterized by microanalysis, FTIR, mass balance, and solid-state NMR (1H, 13C, 1H-13C HETCOR, 1H-1H double quantum and triple quantum) and identified as [(≡Si-O-)WMe5] and another product, [(≡Si-O-)WMe2(≡CH)]. The latter might have been generated by partial decomposition of the tungsten methyl chloride compound, which is formed during the stepwise alkylation of [(≡Si-O-)WCl5]. DFT calculations were carried out to check the relative stability of the tungsten methyl chloride intermediates and the feasibility of the reaction and corroborate the experimental results. This tungsten complex and its derivative were found to be active catalysts for the metathesis of cyclooctane. © 2016 American Chemical Society.

  8. In situ investigation of helium fuzz growth on tungsten in relation to ion flux, fluence, surface temperature and ion energy using infrared imaging in PSI-2

    International Nuclear Information System (INIS)

    Möller, S; Kachko, O; Rasinski, M; Kreter, A; Linsmeier, Ch

    2017-01-01

    Tungsten is a candidate material for plasma-facing components in nuclear fusion reactors. In operation it will face temperatures >800 K together with an influx of helium ions. Previously, the evolution of special surface nanostructures called fuzz was found under these conditions in a limited window of surface temperature, ion flux and ion energy. Fuzz potentially leads to lower heat load tolerances, enhanced erosion and dust formation, hence should be avoided in a fusion reactor. Here the fuzz growth is reinvestigated in situ during its growth by considering its impact on the surfaces infrared emissivity at 4 μ m wavelength with an infrared camera in the linear plasma device PSI-2. A hole in the surface serves as an emissivity reference to calibrate fuzz thickness versus infrared emissivity. Among new data on the above mentioned relations, a lower fuzz growth threshold of 815 ± 24 K is found. Fuzz is seen to grow on rough and polished surfaces and even on the hole’s side walls alike. Literature scalings for thickness, flux and time relations of the fuzz growth rate could not be reproduced, but for the temperature scaling a good agreement to the Arrhenius equation was found. (paper)

  9. Investigation of the internal electric field distribution under in situ x-ray irradiation and under low temperature conditions by the means of the Pockels effect

    International Nuclear Information System (INIS)

    Prekas, G; Sellin, P J; Veeramani, P; Davies, A W; Lohstroh, A; Oezsan, M E; Veale, M C

    2010-01-01

    The internal electric field distribution in cadmium zinc telluride (CdZnTe) x-ray and γ-ray detectors strongly affects their performance in terms of charge transport and charge collection properties. In CdZnTe detectors the electric field distribution is sensitively dependent on not only the nature of the metal contacts but also on the working conditions of the devices such as the temperature and the rate of external irradiation. Here we present direct measurements of the electric field profiles in CdZnTe detectors obtained using the Pockels electo-optic effect whilst under in situ x-ray irradiation. These data are also compared with alpha particle induced current pulses obtained by the transient current technique, and we discuss the influence of both low temperature and x-ray irradiation on the electric field evolution. Results from these studies reveal strong distortion of the electric field consistent with the build-up of space charge at temperatures below 250 K, even in the absence of external irradiation. Also, in the presence of x-ray irradiation levels a significant distortion in the electric field is observed even at room temperature which matches well the predicted theoretical model.

  10. In situ investigation of explosive crystallization in a-Ge: Experimental determination of the interface response function using dynamic transmission electron microscopy

    International Nuclear Information System (INIS)

    Nikolova, Liliya; MacLeod, Jennifer M.; Ibrahim, Heide; Stern, Mark J.; Siwick, Bradley J.; Reed, Bryan W.; Campbell, Geoffrey H.; LaGrange, Thomas; Rosei, Federico

    2014-01-01

    The crystallization of amorphous semiconductors is a strongly exothermic process. Once initiated the release of latent heat can be sufficient to drive a self-sustaining crystallization front through the material in a manner that has been described as explosive. Here, we perform a quantitative in situ study of explosive crystallization in amorphous germanium using dynamic transmission electron microscopy. Direct observations of the speed of the explosive crystallization front as it evolves along a laser-imprinted temperature gradient are used to experimentally determine the complete interface response function (i.e., the temperature-dependent front propagation speed) for this process, which reaches a peak of 16 m/s. Fitting to the Frenkel-Wilson kinetic law demonstrates that the diffusivity of the material locally/immediately in advance of the explosive crystallization front is inconsistent with those of a liquid phase. This result suggests a modification to the liquid-mediated mechanism commonly used to describe this process that replaces the phase change at the leading amorphous-liquid interface with a change in bonding character (from covalent to metallic) occurring in the hot amorphous material

  11. The contribution of risk factors to the higher incidence of invasive and in situ breast cancers in women with higher levels of education in the European prospective investigation into cancer and nutrition

    Science.gov (United States)

    Menvielle, Gwenn; Kunst, Anton E.; Van Gils, Carla H.; Peeters, Petra H. M.; Boshuizen, Hendriek; Overvad, Kim; Olsen, Anja; Tjonneland, Anne; Hermann, Silke; Kaaks, Rudolf; Bergmann, Manuela M.; Illner, Anne-Kathrin; Lagiou, Pagona; Trichopoulos, Dimitrios; Trichopoulou, Antonia; Palli, Domenico; Berrino, Franco; Mattiello, Amelia; Tumino, Rosario; Sacerdote, Carlotta; May, Anne; Monninkhof, Evelyn; Braaten, Tonje; Lund, Eiliv; Quirós, José Ramón; Duell, Eric J.; Sánchez, Maria-José; Navarro, Carmen; Ardanaz, Eva; Borgquist, Signe; Manjer, Jonas; Khaw, Kay Tee; Allen, Naomi E.; Reeves, Gillian K.; Chajes, Véronique; Rinaldi, Sabina; Slimani, Nadia; Gallo, Valentina; Vineis, Paolo; Riboli, Elio; Bueno-de-Mesquita, H Bas

    2011-01-01

    This paper aims to investigate the role of known risk factors in explaining educational differences in breast cancer incidence. Analyses were based on the European Prospective Investigation into Cancer and Nutrition, and included 242,095 women, 433 in situ and 4,469 invasive breast cancers. Reproductive history (age at first full term pregnancy and parity), exposure to endogenous and exogenous hormones, height, and health behaviours were accounted for in the analyses. Relative indices of inequality (RII) for education were estimated using Cox regression models. Higher invasive breast cancer risk was found among women with higher education (RII=1.22: 1.09,1.37). This association was not observed among nulliparous women (RII=1.13: 0.84,1.52). Inequalities in breast cancer incidence decreased substantially after adjusting for reproductive history (RII=1.11: 0.98,1.25), most of the association being explained by age at first full term pregnancy. Each other risk factor explained a small additional part of inequalities in breast cancer incidence. Height contributed most of these factors. When all known risk factors were adjusted for, no association remained between education and invasive breast cancer risk. Inequalities in incidence were more pronounced for in situ breast cancers and remained after adjustment for all known risk factors (RII=1.61: 1.07,2.41), especially among nulliparous women. PMID:21084553

  12. N-Ethylmaleimide–Sensitive Factor b (nsfb) Is Required for Normal Pigmentation of the Zebrafish Retinal Pigment Epithelium

    Science.gov (United States)

    Hanovice, Nicholas J.; Daly, Christina M. S.; Gross, Jeffrey M.

    2015-01-01

    Purpose Despite the number of albinism-causing mutations identified in human patients and animal models, there remain a significant number of cases for which no mutation has been identified, suggesting that our understanding of melanogenesis is incomplete. Previously, we identified two oculocutaneous albinism mutations in zebrafish, au13 and au18. Here, we sought to identify the mutated loci and determine how the affected proteins contribute to normal pigmentation of the retinal pigment epithelium (RPE). Methods Complementation analyses revealed that au13 and au18 belonged to a single complementation group, suggesting that they affected the same locus. Whole-genome sequencing and single nucleotide polymorphism (SNP) analysis was performed to identify putative mutations, which were confirmed by cDNA sequencing and mRNA rescue. Transmission electron microscopy (TEM) and image quantification were used to identify the cellular basis of hypopigmentation. Results Whole-genome sequencing and SNP mapping identified a nonsense mutation in the N-ethylmaleimide–sensitive factor b (nsfb) gene in au18 mutants. Complementary DNA sequencing confirmed the presence of the mutation (C893T), which truncates the nsfb protein by roughly two-thirds (Y297X). No coding sequence mutations were identified in au13, but quantitative PCR revealed a significant decrease in nsfb expression, and nsfb mRNA injection rescued the hypopigmentation phenotype, suggesting a regulatory mutation. In situ hybridization revealed that nsfb is broadly expressed during embryonic development, including in the RPE. Transmission electron microscopy analyses indicated that average melanosome density and maturity were significantly decreased in nsfb mutants. Conclusions au18 and au13 contain mutations in nsfb, which encodes a protein that is required for the maturation of melanosomes in zebrafish RPE. PMID:26618645

  13. N-Ethylmaleimide-Sensitive Factor b (nsfb) Is Required for Normal Pigmentation of the Zebrafish Retinal Pigment Epithelium.

    Science.gov (United States)

    Hanovice, Nicholas J; Daly, Christina M S; Gross, Jeffrey M

    2015-11-01

    Despite the number of albinism-causing mutations identified in human patients and animal models, there remain a significant number of cases for which no mutation has been identified, suggesting that our understanding of melanogenesis is incomplete. Previously, we identified two oculocutaneous albinism mutations in zebrafish, au13 and au18. Here, we sought to identify the mutated loci and determine how the affected proteins contribute to normal pigmentation of the retinal pigment epithelium (RPE). Complementation analyses revealed that au13 and au18 belonged to a single complementation group, suggesting that they affected the same locus. Whole-genome sequencing and single nucleotide polymorphism (SNP) analysis was performed to identify putative mutations, which were confirmed by cDNA sequencing and mRNA rescue. Transmission electron microscopy (TEM) and image quantification were used to identify the cellular basis of hypopigmentation. Whole-genome sequencing and SNP mapping identified a nonsense mutation in the N-ethylmaleimide-sensitive factor b (nsfb) gene in au18 mutants. Complementary DNA sequencing confirmed the presence of the mutation (C893T), which truncates the nsfb protein by roughly two-thirds (Y297X). No coding sequence mutations were identified in au13, but quantitative PCR revealed a significant decrease in nsfb expression, and nsfb mRNA injection rescued the hypopigmentation phenotype, suggesting a regulatory mutation. In situ hybridization revealed that nsfb is broadly expressed during embryonic development, including in the RPE. Transmission electron microscopy analyses indicated that average melanosome density and maturity were significantly decreased in nsfb mutants. au18 and au13 contain mutations in nsfb, which encodes a protein that is required for the maturation of melanosomes in zebrafish RPE.

  14. Neoplasia versus hyperplasia of the retinal pigment epithelium

    DEFF Research Database (Denmark)

    Heegaard, Steffen; Larsen, J.N.B.; Fledelius, Hans C.

    2001-01-01

    ophthalmology, retinal pigment epithelium, adenoma, tumor-like hyperplasia, histology, immunohistochemistry, tumor, neoplasm, ultrasonography......ophthalmology, retinal pigment epithelium, adenoma, tumor-like hyperplasia, histology, immunohistochemistry, tumor, neoplasm, ultrasonography...

  15. Photoacclimation in microphytobenthos and the role of xanthophyll pigments

    NARCIS (Netherlands)

    Van Leeuwe, Maria A.; Brotas, Vanda; Consalvey, Mireille; Forster, Rodney M.; Gillespie, David; Jesus, Bruno; Roggeveld, Jan; Gieskes, Winfried W. C.

    2008-01-01

    Estuarine microphytobenthos are frequently exposed to excessively high irradiances. Photoinhibition in microalgae is prevented by various photophysiological responses. We describe here the role of the xanthophyll pigments in photoacclimation. The pigment composition of the microphytobenthos was

  16. Effect of Quinacridone Pigments on Properties and Morphology of Injection Molded Isotactic Polypropylene

    Directory of Open Access Journals (Sweden)

    Mateusz Barczewski

    2017-01-01

    Full Text Available Two quinacridone pigments were added (0.01; 0.05; 0.1; 0.5; 1; 2 wt% to isotactic polypropylene (iPP, and their influence on mechanical and thermomechanical properties were investigated. Complex mechanical and thermomechanical iPP properties analyses, including static tensile test, Dynstat impact resistance measurement, and hardness test, as well as dynamic mechanic thermal analysis (DMTA, were realized in reference to morphological changes of polymeric materials. In order to understand the differences in modification efficiency and changes in polymorphism of polypropylene matrix caused by incorporation of pigments, differential scanning calorimetry (DSC and wide-angle X-ray scattering (WAXS experiments were done. Both pigments acted as highly effective nucleating agents that influence morphology and mechanical properties of isotactic polypropylene injection molded samples. Differences between polypropylene samples nucleated by two pigments may be attributed to different heterogeneous nucleation behavior dependent on pigment type. As it was proved by WAXS investigations, the addition of γ-quinacridone (E5B led to crystallization of polypropylene in hexagonal phase (β-iPP, while for β-quinacridone (ER 02 modified polypropylene no evidence of iPP β-phase was observed.

  17. Dermoscopy Clues in Pigmented Bowen's Disease

    Directory of Open Access Journals (Sweden)

    Daniela Gutiérrez-Mendoza

    2010-01-01

    Full Text Available Pigmented tumors have similar clinical features that overlap and hamper diagnosis. Dermoscopy increases the diagnostic accuracy of doubtful melanocytic lesions and has been used as a noninvasive tool in the detection of pigmented lesions (PLs like melanoma, basal cell carcinoma, and pigmented Bowen's disease (pBD. Our objective was to show the dermoscopic features of 2 cases of pBD and compare with the findings reported in the literature. Two dermoscopic images of biopsy proven pBD were retrospectively analyzed for dermoscopic patterns. Both cases showed brown regular globules, structureless brown and blue pigmentation, glomerular vessels, hypopigmented regression-like areas, and keratosis. These findings were similar to the cases reported previously. The dermoscopic diagnosis of pBD is based on the absence of criteria for a melanocytic lesion in the presence of glomerular vessels, regular brown globules and keratosis. Although pBD is rare, it should be included in the differential diagnosis of PLs, especially melanoma.

  18. Gingival pigmentation reduction: A novel therapeutic modality

    Directory of Open Access Journals (Sweden)

    H V Mahesh

    2012-01-01

    Full Text Available Aim: The objective of the present clinical study was to compare the effectiveness of radiofrequency de-epithelialization and conventional (slicing method in reducing gingival pigmentation on long term basis by split mouth design. Materials and Methods: A total of 28 maxillary gingival units from 4 subjects aged between 15-30 years were considered for this clincal study and the selected gingival units were made plaque free and clinically healthy before subjectiing these sites to one of the procedures. The selected sites were abraded by either the conventional (slicing method (14 gingival units of 21, 22, 23, 24 or by radiofrequency (14 gingival units of 11, 12, 13, 14. After the procedure periodontal dressing was applied to protect the operated area. After 1 week periodontal dressing was removed and the area was irrigated with saline. Follow up examination was done on 30th, 60th and 90 th days to evaluate the recurrence of pigmentation, if any. Results: It was obsereved that, sites operated with conventional (slicing method, showed higher mean pigmentation than the sites treated with the radioablation during the follow up period of 90 days. Conclusion: When used judiciously, radiofrequency can be clinically valuable, safe and effective method to reduce pigmentation of gingiva.

  19. Gingival Pigmentation Reduction: A Novel Therapeutic Modality

    Science.gov (United States)

    Mahesh, H V; Harish, M R; Shashikumar, B M; Ramya, K S

    2012-01-01

    Aim: The objective of the present clinical study was to compare the effectiveness of radiofrequency de-epithelialization and conventional (slicing) method in reducing gingival pigmentation on long term basis by split mouth design. Materials and Methods: A total of 28 maxillary gingival units from 4 subjects aged between 15-30 years were considered for this clincal study and the selected gingival units were made plaque free and clinically healthy before subjectiing these sites to one of the procedures. The selected sites were abraded by either the conventional (slicing) method (14 gingival units of 21, 22, 23, 24) or by radiofrequency (14 gingival units of 11, 12, 13, 14). After the procedure periodontal dressing was applied to protect the operated area. After 1 week periodontal dressing was removed and the area was irrigated with saline. Follow up examination was done on 30th, 60th and 90th days to evaluate the recurrence of pigmentation, if any. Results: It was obsereved that, sites operated with conventional (slicing) method, showed higher mean pigmentation than the sites treated with the radioablation during the follow up period of 90 days. Conclusion: When used judiciously, radiofrequency can be clinically valuable, safe and effective method to reduce pigmentation of gingiva. PMID:23060709

  20. The mechanism of gingiva metallic pigmentations formation

    Czech Academy of Sciences Publication Activity Database

    Joska, L.; Venclíková, Z.; Poddaná, M.; Benada, Oldřich

    2009-01-01

    Roč. 13, č. 1 (2009), s. 1-7 ISSN 1432-6981 R&D Projects: GA MZd NR9124 Institutional research plan: CEZ:AV0Z50200510 Keywords : pigmentation * gingiva * electrochemistry Subject RIV: EC - Immunology Impact factor: 2.233, year: 2009