Gotowe bibliografie tematyczne / Temperature dependent Raman measurements

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Gotowa bibliografia na temat „Temperature dependent Raman measurements”

Autor: Grafiati
Data publikacji: 6 września 2023

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Artykuły w czasopismach na temat "Temperature dependent Raman measurements"

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Yumigeta, Kentaro, Yashika Attarde, Jan Kopaczek, Mohammed Y. Sayyad, Yuxia Shen, Mark Blei, Seyed Tohid Rajaei Moosavy, Ying Qin, Renee Sailus i Sefaattin Tongay. "The phononic and charge density wave behavior of entire rare-earth tritelluride series with chemical pressure and temperature". APL Materials 10, nr 11 (1.11.2022): 111112. http://dx.doi.org/10.1063/5.0110395.

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Here, we present comprehensive phononic and charge density wave properties (CDW) of rare-earth van der Waals tritellurides through temperature dependent angle-resolved Raman spectroscopy measurements. All the possible rare-earth tritellurides (RTe3) ranging from R = La–Nd, Sm, Gd–Tm were synthesized through a chemical vapor transport technique to achieve high quality crystals with excellent CDW characteristics. Raman spectroscopy studies successfully identify the emergence of the CDW state and transition temperature (TCDW), which offers a non-destructive method to identify their CDW response with micron spatial resolution. Temperature dependent Raman measurements further correlate how the atomic mass of metal cations and the resulting chemical pressure influence its CDW properties and offer detailed insight into the strength of CDW amplitude mode-phonon coupling during the CDW transition. Angle-resolved Raman measurements offer the first insights into the CDW-phonon symmetry interplay by monitoring the change in the symmetry of phonon mode across the CDW transition. Overall results introduce the library of RTe3 CDW materials and establish their characteristics through the non-destructive angle-resolved Raman spectroscopy technique.
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Sagitova, E. A., P. Donfack, K. A. Prokhorov, S. M. Kuznetsov, M. A. Guseva, V. A. Gerasin, G. Yu Nikolaeva i A. Materny. "Sensitive temperature-dependent phase resolution of polyethylene-clay nanocomposites". Laser Physics 32, nr 8 (15.06.2022): 084009. http://dx.doi.org/10.1088/1555-6611/ac7334.

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Abstract With the help of spectroscopic and differential scanning calorimetry (DSC) techniques, we have studied conformational and phase reorganizations as function of temperature in intercalated polymer-clay nanocomposites based on low-, middle-, and high-density polyethylene (PE) matrices. We show that Raman spectroscopy is sensitive to structural changes appearing during heating at much lower temperatures (about 47 °C) in comparison to DSC measurements. In fact, in the melting region where DSC traces show endotherms, Raman spectra reveal dramatic changes in the phase and conformational compositions of PE and PE-matrices within PE-clay nanocomposites. Noteworthy, the structural reorganization pathway, through which the semicrystalline nanocomposites transform into a melt state, depends primarily on the PE density and weakly on the filler (nanoclay). Moreover, the temperature-dependent crystallinity degree and the total amount of trans-conformers of the PE system are determined, and the evidence for the formation of intermediate crystal-like phase during heating is shown.
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Unger, Miriam, Harumi Sato, Yukihiro Ozaki, Dieter Fischer i Heinz W. Siesler. "Temperature-Dependent Fourier Transform Infrared Spectroscopy and Raman Mapping Spectroscopy of Phase-Separation in a Poly(3-hydroxybutyrate)–Poly(l-Lactic Acid) Blend". Applied Spectroscopy 67, nr 2 (luty 2013): 141–48. http://dx.doi.org/10.1366/12-06712.

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Variable-temperature Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopic mapping measurements were applied to study the phase separation of a poly(3-hydroxybutyrate) (PHB)–poly(l-lactic acid) (PLA) (50:50 wt.%) polymer-blend film as a function of temperature between 25 and 175 °C. Because of the better band separation compared with the fundamental absorptions, the first overtones of the v(C=O) bands of PHB and PLA were used to evaluate the temperature-dependent FT-IR images as PLA–PHB and PHB–PLA band-ratio contour plots, respectively. From the visualization of the band-ratio FT-IR images, it could be derived that even beyond the melting point of PLA (145 °C), the lateral position and the geometry of the PHB-rich and PLA-rich phases were retained up to 165 °C. Furthermore, the FT-IR images derived during and after the melting of PHB (174 °C) provided an interesting insight into the homogenization process of the polymer melt. By exploiting its higher lateral resolution, valuable additional information became available from the Raman mapping measurements. Based on the Raman data, the scenario of phase-separated PHB-rich and PLA-rich domains of about 50 iμ size, based on the FT-IR imaging measurements, had to be revised. Instead, the originally interpreted PHB-rich and PLA-rich domains are actually clusters of much smaller grains. Additionally, the Raman images measured in the same temperature interval revealed that the clusters of small PHB-rich grain structures aggregated as a function of temperature increase. These investigations prove that FT-IR and Raman imaging in combination with variable-temperature measurements can provide new (and so far unavailable) insights into structural phenomena of phase-separated polymer blends.
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Miao, Peng, Jie Wu, Yunchen Du, Yanchun Sun i Ping Xu. "Phase transition induced Raman enhancement on vanadium dioxide (VO2) nanosheets". Journal of Materials Chemistry C 6, nr 40 (2018): 10855–60. http://dx.doi.org/10.1039/c8tc04269a.

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Crystal symmetry matters: with the increase in the crystal symmetry from VO2(B) to VO2(M) and to VO2(R), a dramatic decline in Raman enhancement on VO2 nanosheets is revealed through temperature-dependent Raman measurements.
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Shvets, Petr, Ksenia Maksimova i Alexander Goikhman. "Raman Spectroscopy of V4O7 Films". Coatings 12, nr 3 (22.02.2022): 291. http://dx.doi.org/10.3390/coatings12030291.

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A thin film of vanadium oxide Magnéli phase V4O7 was produced using cathodic arc sputtering. X-ray diffraction, Rutherford backscattering spectrometry and Raman investigations confirmed the formation of this phase. The Raman spectrum of V4O7 differs considerably from the spectrum of another Magnéli oxide, V3O5, showing that Raman spectroscopy is an excellent tool for distinguishing between these two phases. Temperature-dependent Raman measurements revealed a significant change of the spectra near the V4O7 metal–insulator phase transition.
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Holloway, Simon, Hugo Ricketts i Geraint Vaughan. "Boundary layer temperature measurements of a noctual urban boundary layer". EPJ Web of Conferences 176 (2018): 06004. http://dx.doi.org/10.1051/epjconf/201817606004.

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A low-power lidar system based in Manchester, United Kingdom has been developed to measure temperature profiles in the nocturnal urban boundary layer. The lidar transmitter uses a 355nm diode-pumped solid state Nd:YAG laser and two narrow-band interference filters in the receiver filter out rotational Raman lines that are dependent on temperature. The spectral response of the lidar is calibrated using a monochromator. Temperature profiles measured by the system are calibrated by comparison to co-located radiosondes.
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Gogolin, Mathias, M. Mangir Murshed, Lkhamsuren Bayarjargal, Detlef Klimm i Thorsten M. Gesing. "Thermal anomalies and phase transitions in Pb2Sc2Si2O9 and Pb2In2Si2O9". Zeitschrift für Kristallographie - Crystalline Materials 236, nr 11-12 (19.10.2021): 283–92. http://dx.doi.org/10.1515/zkri-2021-2046.

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Abstract Pb2Sc2Si2O9 and Pb2In2Si2O9, respectively, the scandium and indium containing structural analogues of the mineral kentrolite are grown by spontaneous crystallization from a PbO flux. The corresponding polycrystalline powder samples are synthesized by conventional solid-state approach. The compounds are thoroughly characterized using temperature-dependent single crystal and powder X-ray diffraction, heat capacity measurements, second harmonic generation experiments and Raman spectroscopy. At ambient conditions, both compounds crystallize in the non-centrosymmetric Pna21 space group and undergo phase transitions to the centrosymmetric Pbcn space group at elevated temperatures. The Pbcn into Pna21 phase transitions are complemented by the signals of the temperature-dependent second harmonic generation. The specific heat capacity exhibits distinct cusp, supporting the λ-type second-order phase transition. The temperature dependency of some selective Raman modes further complements the findings, showing softening and hardening of the phonons across the phase transitions.
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Pan, Xiaoguang, Tianwen Yang, Hangxin Bai, Jiangbo Peng, Lujie Li, Fangli Jing, Hailong Qiu, Hongjun Liu i Zhanggui Hu. "Controllable Synthesis and Charge Density Wave Phase Transitions of Two-Dimensional 1T-TaS2 Crystals". Nanomaterials 13, nr 11 (5.06.2023): 1806. http://dx.doi.org/10.3390/nano13111806.

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1T-TaS2 has attracted much attention recently due to its abundant charge density wave phases. In this work, high-quality two-dimensional 1T-TaS2 crystals were successfully synthesized by a chemical vapor deposition method with controllable layer numbers, confirmed by the structural characterization. Based on the as-grown samples, their thickness-dependency nearly commensurate charge density wave/commensurate charge density wave phase transitions was revealed by the combination of the temperature-dependent resistance measurements and Raman spectra. The phase transition temperature increased with increasing thickness, but no apparent phase transition was found on the 2~3 nm thick crystals from temperature-dependent Raman spectra. The transition hysteresis loops due to temperature-dependent resistance changes of 1T-TaS2 can be used for memory devices and oscillators, making 1T-TaS2 a promising material for various electronic applications.
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Hagemann, H., J. Mareda, C. Chiancone i H. Bill. "Conformational studies of 2-butanol using temperature-dependent Raman measurements and MM3 calculations". Journal of Molecular Structure 410-411 (czerwiec 1997): 357–60. http://dx.doi.org/10.1016/s0022-2860(96)09584-1.

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Felhi, Houda, Mourad Smari, Saber Mansouri, Jalel Massoudi i Essebti Dhahri. "Deciphering the Structural Characterization, Hirshfeld Surface Analysis, Raman Studies, and Temperature-Dependent Magnetodielectric Properties of BiMn2O5". Magnetochemistry 7, nr 5 (16.05.2021): 68. http://dx.doi.org/10.3390/magnetochemistry7050068.

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We investigate the structural, Hirshfeld surface, magnetic, and magnetodielectric properties of BiMn2O5. The sample can be indexed with an orthorhombic phase associated with space group Pbam, with crystallographic parameters a = 7.54946 Å, b = 8.54962 Å and c = 5.753627 Å. The Hirshfeld surface analysis, associated with 2D fingerprint plots, was used to visualize and explore the significant intermolecular interactions in the crystal structure quantitatively. The Raman spectra, measured from 6 to 300 K in a frequency range between 250 and 750 cm−1, exhibit good agreement between the SHELL model calculations and the experimental measurement of the proximity of the phonon frequencies for our sample. Furthermore, magnetic measurements show that BiMn2O5 becomes antiferromagnetic below the Néel temperature (TN)—the temperature above which an antiferromagnetic material becomes paramagnetic (TN = 31 K). The relaxation at intermediate temperatures (200–300 K) can be attributed to the polar jump process at two charge transfer sites between the Mn3+ and Mn4+ ions, which, in combination with the special arrangement of the Mn3+/Mn4+ ions, is likely to produce the strong intrinsic magnetodielectric effect (MD) in the same temperature range.
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Rozprawy doktorskie na temat "Temperature dependent Raman measurements"

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Lee, Robert Benjamin III. "Tropospheric temperature measurements using a rotational raman lidar". Thesis, Hampton University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3592881.

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Using the Hampton University (HU) Mie and Raman lidar, tropospheric temperature profiles were inferred from lidar measurements of anti-Stokes rotational Raman (RR) backscattered laser light from atmospheric nitrogen and oxygen molecules. The molecules were excited by 354.7 nanometer (nm) laser light emitted by the HU lidar. Averaged over 60-minute intervals, RR backscattered signals were detected in narrow 353.35 nm and 354.20 nm spectral bands with full-widths-at-half-maxima (FWHM) of 0.3 nm. During the special April 19-30, 2012, Ground-Based Remote Atmospheric Sounding Program (GRASP) campaign, the lidar temperature calibration coefficients were empirically derived using linear least squares and second order polynomial analyses of the lidar backscattered RR signals and of reference temperature profiles, obtained from radiosondes. The GRASP radiosondes were launched within 400 meters of the HU lidar site. Lidar derived temperature profiles were obtained at altitudes from the surface to over 18 kilometers (km) at night, and up to 5 km during the day. Using coefficients generated from least squares analyses, nighttime profiles were found to agree with profiles from reference radiosonde measurements within 3 K, at altitudes between 4 km and 9 km. Coefficients generated from the second order analyses yielded profiles which agreed with the reference profiles within 1 K uncertainty level in the 4 km to 10 km altitude region. Using profiles from GRASP radiosondes, the spatial and temporal homogeneities of the atmosphere, over HU, were estimated at the 1.5 K level within a 10 km radius of HU, and for observational periods approaching 3 hours. Theoretical calibration coefficients were derived from the optical and physical properties of the HU RR lidar and from the spectroscopic properties of atmospheric molecular nitrogen and oxygen. The theoretical coefficients along with lidar measurements of sky background radiances were used to evaluate the temporal stability of the empirically derived temperature profiles from the RR lidar measurements. The evaluations revealed systematic drifts in the coefficients. Frequent reference radiosonde temperature profiles should be used to correct for the drifts in the coefficients.

For the first time, the cause of the coefficient drifts has been identified as the differences in the aging of the spectral responses of the HU lidar detector pairs. For the first time, the use of lidar sky background measurements was demonstrated as a useful technique to correct for the coefficient drift. This research should advance the derivations of lidar temperature calibration coefficients which can be used for long observational periods of temperature fields without the need for frequent lidar calibrations using radiosondes.

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Lee, Sheng-Chiang. "Measurements of doping dependent microwave nonlinearities in high-temperature superconductors". College Park, Md. : University of Maryland, 2004. http://hdl.handle.net/1903/1372.

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Thesis (Ph. D.) -- University of Maryland, College Park, 2004.
Thesis research directed by: Physics. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Jeyashekar, Nigil Satish. "Temperature and number density measurements using Raman scattering in turbulent-supersonic-combusting flows /". Full text available from ProQuest UM Digital Dissertations, 2006. http://0-proquest.umi.com.umiss.lib.olemiss.edu/pqdweb?index=0&did=1379528381&SrchMode=1&sid=4&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1217357303&clientId=22256.

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Speriatu, Lucian M. "Temperature dependent mechanical properties of composite materials and uncertainties in experimental measurements". [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0011370.

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Dupee, James David. "On-line crystallinity and temperature measurements of nylon 6,6 using a remote laser Raman probe". Thesis, Queen Mary, University of London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287935.

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Celik, Hakan. "Time and Temperature Dependent Surface Tension Measurements of Responsive Protein-based Polymer Surfactant Solutions". Cleveland State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=csu1440182119.

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Abel, Mark Richard. "Thermal Metrology of Polysilicon MEMS using Raman Spectroscopy". Thesis, Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7181.

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The development of microscale and nanoscale devices has outpaced the development of metrology tools necessary for their complete characterization. In the area of thermal MEMS technology, accurate measurements across a broad range of temperatures with high spatial resolution are not trivial. Thermal MEMS are devices in which the control and manipulation of temperature is necessary to perform a desired function, and are used in actuation, chemical sensing, nanolithography, thermal data storage, biological reactions and power generation. In order to properly design for reliability and performance issues amongst these devices and verify modeling accuracy, the temperature distribution under device operating conditions must be experimentally determined. Raman spectroscopy provides absolute temperature measurements with spatial scales below 1 micron, which is sufficient for most MEMS devices. In this work, a detailed study of Raman spectroscopy as an optical thermal metrology tool was performed. It is shown that a calibration of the Stokes shift with temperature yields a linear calibration for measurements up to 1000?n polysilicon. These coefficients were determined for polysilicon processed under various conditions (575-620?B and P doping) to assess the effects of microstructural variations on Raman spectra. The Stokes peak was also shown to shift linearly with an applied pure bending stress. In order to make stress-independent thermometry measurements, the ratio of the Stokes to anti-Stokes signal intensities and the Stokes linewidth were calibrated over the same temperature range. Using the calibration data, Raman spectroscopy was implemented for the evaluation of temperature of thermal MEMS. Heated AFM cantilevers and micro-beam heaters were chosen due to their wide range of applications. Different thermal and mechanical boundary conditions were considered by studying both the beams and cantilevers, resulting in varying levels of thermal stress. By using the three calibrations in a complementary fashion, the validity of Raman thermometry was explored. Device temperatures of up to 650?nd their corresponding uncertainties were found, and used to verify FEA modeling. Effects of thermally induced stresses were taken into account and analyzed. Possible uncertainties such as laser heating, spatial and spectral resolution, light collection efficiency, measurement uncertainty, and instrumental drift were reported and elucidated.
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Prastiyanto, Dhidik [Verfasser]. "Temperature- and Time-Dependent Dielectric Measurements and Modelling on Curing of Polymer Composites / Dhidik Prastiyanto". Karlsruhe : KIT Scientific Publishing, 2016. http://www.ksp.kit.edu.

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Pomeroy, James Wayne. "A temperature and pressure dependent Raman scattering study of III-nitride, icosahedral boride semiconductors and their devices". Thesis, University of Bristol, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.431633.

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Treiss, Stephanie. "TIME-DEPENDENT SURFACE TEMPERATURE and HEAT FLUX MEASUREMENTS on a SINGLE CYLINDER ENGINE HEAD and LINER". The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1512061036731254.

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Książki na temat "Temperature dependent Raman measurements"

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Wardlaw, Graeme M. Kr-Ar laser Raman spectrometer for low temperature measurements. St. Catharines, Ont: Brock University, Dept. of Physics, 2004.

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Barton, S. A. Precision of single-pulse CARS temperature measurements in a hydrocarbon flame. Valcartier, Que: Defence Research Establishment, Valcartier, 1988.

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L, McKenzie Robert, i Ames Research Center, red. Measurements of density,temperature, and their fluctuations in turbulent supersonic flow using UV laser spectroscopy. Moffett Field, Calif: National Aeronautics and Space Administration, Ames Research Center, 1992.

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L, McKenzie R., i Ames Research Center, red. Measurements of density,temperature, and their fluctuations in turbulent supersonic flow using UV laser spectroscopy. Moffett Field, Calif: National Aeronautics and Space Administration, Ames Research Center, 1992.

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L, McKenzie Robert, i Ames Research Center, red. Measurements of density,temperature, and their fluctuations in turbulent supersonic flow using UV laser spectroscopy. Moffett Field, Calif: National Aeronautics and Space Administration, Ames Research Center, 1992.

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Steiner, Myles A. Temperature-dependent measurements of an inverted metamorphic multijunction (IMM) solar cell: Preprint. Golden, CO]: National Renewable Energy Laboratory, 2011.

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Measurements of density,temperature, and their fluctuations in turbulent supersonic flow using UV laser spectroscopy. Moffett Field, Calif: National Aeronautics and Space Administration, Ames Research Center, 1992.

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Panigrahi, Muktikanta, i Arpan Kumar Nayak. Polyaniline based Composite for Gas Sensors. IOR PRESS, 2021. http://dx.doi.org/10.34256/ioriip212.

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In this research work, we have demonstrated the synthesis, spectroscopic characteristics, thermal behaviour and DC conductivity of a few nanostructured composites, substituted conducting polymers (ICPs) and composites of ICPs. The physical properties of aforementioned composites are significantly changed by the doping with HCl, H2SO4, HNO3, H3PO4, or acrylic acid. The charge transport properties of these polymeric materials have been studied in detail because of their potential application in gas sensors. In the current work, varieties of conducting polymer based materials such as PANI-ES/Cloisite 20A nanostructured composite, acrylic acid (AA) doped PANI polymer, N-substituted conducting polyaniline polymer, DL−PLA/PANI-ES composites, poly methyl methacrylate (PMMA) based polyaniline composite, and inorganic acid doped polyaniline are sucessfuly synthesized using aniline/aniline hydrochloride as precursors in acidic medium. Particularly, AA based synthesised PANI polymer was found with higher solubility The spectroscopic, thermal stability, enthalpy of fusion, room temperature DC conductivity and temperature dependent DC conductivity measurements with and without magnetic was carried out with as-synthesized materials. The FTR/ATR−FTIR spectra indicated the presence of different functional groups in the as-prepared composite materials. The UV−Visible absorption spectroscopic analysis showed the presence of polaron band suggesting PANI-ES form. The Room temperature DC conductivity, temperature variation DC conductivity (in presence and absence of magnetic field), and magnetoresistance (MR) of as-prepared conducting polyaniline based were analysed. The highest room temperature DC conductivity value was obtained from H2SO4 doped based composite materials and all prepared conductive composites were followed ohms law. The low temperature DC conductivity was carried out in order to study the semiconducting nature of prepared materials. The Mott type VRH model was found to be well fitted the conductivity data and described the density of states at the Fermi level which is constant in this temperature range. From MR plots, a negative MR was observed, which described the quantum interference effect on hopping conduction. We discuss different gas analytes i.e., NO2, LPG, H2, NH3, CH4, and CO of conducting polymer based materials.
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Części książek na temat "Temperature dependent Raman measurements"

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Parks, James E., Michael R. Cates, Stephen W. Allison, David L. Beshears, M. Al Akerman i Matthew B. Scudiere. "TEMPERATURE-DEPENDENT FLUORESCENCE MEASUREMENTS". W Handbook of Measurement in Science and Engineering, 2225–44. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2016. http://dx.doi.org/10.1002/9781119244752.ch62.

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Maroni, Victor A. "Characterization: Raman Spectroscopy Measurements and Interpretations". W High Temperature Superconductors, 67–92. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2010. http://dx.doi.org/10.1002/9783527631049.ch3.

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Misra, Prabhakar, Daniel Casimir i Raul Garcia-Sanchez. "Temperature-Dependent Raman Spectroscopy of Graphitic Nanomaterials". W Computational and Experimental Simulations in Engineering, 793–800. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-27053-7_67.

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Wulfmeyer, Volker, i Andreas Behrendt. "Raman Lidar for Water Vapor and Temperature Profiling". W Springer Handbook of Atmospheric Measurements, 719–39. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-52171-4_25.

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Murphy, J. C., L. C. Aamodt i G. C. Wetsel. "Coating Thickness Determination Using Time Dependent Surface Temperature Measurements". W Review of Progress in Quantitative Nondestructive Evaluation, 277–84. Boston, MA: Springer US, 1987. http://dx.doi.org/10.1007/978-1-4613-1893-4_32.

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Lahmann, W., J. Zeyn i C. Weitkamp. "Rotational Raman Lidar for Remote Daytime Measurements of Tropospheric Temperature Profiles". W Advances in Atmospheric Remote Sensing with Lidar, 345–48. Berlin, Heidelberg: Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-642-60612-0_83.

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Yu, Guanglin, Rui Li i Allison Hubel. "Raman Cryomicroscopic Imaging and Sample Holder for Spectroscopic Subzero Temperature Measurements". W Cryopreservation and Freeze-Drying Protocols, 351–61. New York, NY: Springer US, 2020. http://dx.doi.org/10.1007/978-1-0716-0783-1_14.

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Booth, James C., Dong-Ho Wu i Steven M. Anlage. "Measurements of the Frequency Dependent Microwave Fluctuation Conductivity of Cuprate Thin Film Superconductors". W Fluctuation Phenomena in High Temperature Superconductors, 151–78. Dordrecht: Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-011-5536-6_13.

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Lucht, Robert P. "Temperature Measurements by Coherent Anti-Stokes Raman Scattering in Internal Combustion Engines". W Instrumentation for Combustion and Flow in Engines, 341–53. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-009-2241-9_18.

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Yamagishi, S. "Multiple Species Concentration and Temperature Measurements in Hydrocarbon Flame by Pulsed Laser Raman". W Laser Diagnostics and Modeling of Combustion, 125–32. Berlin, Heidelberg: Springer Berlin Heidelberg, 1987. http://dx.doi.org/10.1007/978-3-642-45635-0_16.

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Streszczenia konferencji na temat "Temperature dependent Raman measurements"

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Annen, K. D., A. H. Epstein i F. Kolczak. "Temperature measurements for turbomachinery applications using O2LIF/O2 Raman scattering". W OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/oam.1990.fw6.

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Proof-of-principle experiments have been performed with O2 laser-induced fluorescence (LIF) and O2 Raman scattering to determine temperature for turbomachinery applications. A broadband ArF excimer laser was used in the experiments, and both sidescatter and backscatter configurations were investigated. The O2 LIF signal was collected broadband by means of glass filters and was ratioed to the O2 Raman signal to produce a quantity that was dependent only on temperature in the sidescatter configuration. Experiments in the backscatter configuration showed that spectrally resolved O2 LIF data must be collected to avoid interference from window fluorescence. The experimental results agreed with published computational results on the dependence of the O2LIF emission with temperature. Potential problems and solutions associated with the application of this technique to turbomachinery measurements are discussed.
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Seabrook, Brian C., Andreas Ellmauthaler, Michel LeBlanc, Mikko Jaaskelainen, John L. Maida i Glenn A. Wilson. "Comparison of Raman, Brillouin, and Rayleigh Distributed Temperature Measurements in High-Rate Wells". W 2022 SPWLA 63rd Annual Symposium. Society of Petrophysicists and Well Log Analysts, 2022. http://dx.doi.org/10.30632/spwla-2022-0011.

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With the maturity of and demand for fiber optic sensing technology growing steadily over the last few years across multiple basins, operators are seeking fiber optic sensing solutions that address the technology challenges associated with life-of-field monitoring of subsea developments. Single-ended distributed temperature sensing (DTS) are typically acquired using Raman optical time-domain reflectometry (OTDR) on multi-mode fiber. However, for topside interrogation of subsea completions, Raman DTS performs poorly due to the available optical power budget, and the wavelength dependency of the measured Stokes and anti-Stokes intensities, as the temperature profile is calculated as a function of the ratios of these signals. The optical attenuation across connectors and splices may, in many instances, have a wavelength dependence that varies with temperature and/or directionality of the propagation of the optical signals. Any wavelength dependent attenuation as the signals pass through connectors, splices and optical feedthrough systems will generate step changes in the measured temperature profile. Brillouin OTDR can provide a DTS alternative that overcomes these challenges and operates on single mode fiber. Brillouin OTDR operates with a large dynamic range to measure a wavelength (frequency) shift of the Stokes/anti-Stokes components that is proportional to both strain and temperature. Since downhole cables are manufactured with optical fibers suspended in a gel and with appropriate extra fiber length (EFL), any fiber strain relaxes, and the Brillouin wavelength shift is an absolute temperature measurement. We typically associate coherent Rayleigh OTDR with distributed acoustic sensing (DAS) on single-mode fibers, but low frequencies also contain a relative temperature dependence. In this paper, we report on a comparison of Raman, Brillouin, and Rayleigh DTS simultaneously acquired in the same high-rate producer and injector wells. We validate that, with appropriate cable design, Brillouin DTS can be simultaneously operated on the same single-mode fiber with DAS, and can deliver absolute temperature measurements suitable for production analysis. We conclude with a discussion about the implementation of this DAS-DTS solution for sensing subsea completions.
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Yoshino, Tomoki, Masato Matsumoto, Yasuyuki Ozeki i Kazuyoshi Itoh. "Energy-dependent temperature dynamics in femtosecond laser microprocessing clarified by Raman temperature measurement". W SPIE MOEMS-MEMS, redaktorzy Winston V. Schoenfeld, Raymond C. Rumpf i Georg von Freymann. SPIE, 2012. http://dx.doi.org/10.1117/12.906969.

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Smith, W. L., H. L. Huang, H. E. Revercomb i H. M. Woolf. "On the Combination of Passive and Active Sensing for Achieving Very High Resolution Atmospheric Temperature Profiles". W Optical Remote Sensing of the Atmosphere. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/orsa.1990.tua1.

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Because of the exponential decay of water vapor mixing ratio with altitude, infrared radiance to space originates from very narrow atmospheric layers at altitudes dependent upon the wavelength of measurement. Thus if one could measure the vertical water vapor profile independent of the passive radiance measurements, the vertical temperature profile could be determined with high vertical resolution from a spectrum of upwelling water vapor radiance. The water vapor profiles could be obtained using active lidar techniques such as Differential Absorption Lidar (DIAL) or Raman Lidar which have experimentally demonstrated the capability to achieve water vapor mixing ratio profiles with high vertical resolution.
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Natarajan, Shweta, Bobby G. Watkins, Vinod Adivarahan, Asif Khan i Samuel Graham. "Thermal Characterization of Discrete Device Layers in AlxGa1−xN Based Ultraviolet Light Emitting Diodes". W ASME 2012 Third International Conference on Micro/Nanoscale Heat and Mass Transfer. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/mnhmt2012-75146.

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The temperature rise in LEDs is an important parameter that must be determined for both thermal management and device lifetime/reliability assessment. Commonly used indirect methods of measuring the device temperature either estimate the multiple quantum well (MQW) temperature based on measuring temperature dependent device characteristics (e.g., forward voltage and electroluminescence methods), or they measure the average temperature across the device structure using optical methods such as infrared (IR) thermography and thermoreflectance. However, none give true insight into the vertical distribution of temperature in these structures. In this study, Raman spectroscopy is applied for the first time to operating UV LEDs to give the temperature rise in discrete layers within the LED device structure, going from the growth substrate to layers adjacent to theMQWs. Comparisons are made with IR themography to contrast with this depth sensitive measurement technique. It was observed that the peak temperatures in the device were much higher than the temperatures indicated by IR while the averaged temperatures through the structure compared favorably. Additional comparisons to electroluminescence measurements were also made which compared favorably with the peak temperatures found by Raman Spectroscopy.
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Forsman, J. W., R. L. Farrow i L. A. Rahn. "Inverse Raman Spectroscopy Measurements of Line-Shift Coefficients in Hydrogen Perturbed by Argon". W High Resolution Spectroscopy. Washington, D.C.: Optica Publishing Group, 1993. http://dx.doi.org/10.1364/hrs.1993.mb2.

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High resolution Raman studies of the Q branch in H2 perturbed by Ar are relevant to combustion diagnostics and for tests of the intermolecular potential. The use of spectroscopic techniques to study combustion requires accurate models for the line shapes, which can range front Lorentzian to Gaussian to more complicated profiles1 depending on the perturber species, perturber concentration, density and temperature. Calculations with these models require estimates of the speed dependence of the line-shift and line-broadening coefficients. Modern theories are now able to predict the shifting and broadening resulting from collisions but are hampered by uncertainties in the interaction potential. One of the most studied potentials is that of H2-Ar, which has the advantage of being theoretically tractable for line shape computations. Furthermore, since the masses of Ar and molecular O2 and N2 are similar, spectral features depending on the perturber’s mass are expected to be similar. We report preliminary measurements of the density shift of the Q branch lines in H2 as a function of rotational state and temperature.
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Bisson, Scott E., i J. E. M. Goldsmith. "Measurements of Daytime and Upper Tropospheric Water Vapor Profiles by Raman Lidar". W Optical Remote Sensing of the Atmosphere. Washington, D.C.: Optica Publishing Group, 1995. http://dx.doi.org/10.1364/orsa.1995.thb1.

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One of the most important atmospheric constituents needed for climate and meteorological studies is water vapor. It plays an important role in driving atmospheric circulations through latent heat release and in determining the earth’s radiation budget, both through its radiative effects (water vapor is the major greenhouse gas) and through cloud formation. The vertical distribution of water vapor is particularly important because in addition to determining convective stability, radiative effects are also strongly altitude dependent. In fact, several one-dimensional radiative convective models1 have shown that although upper tropospheric (8-12 km) water vapor concentrations are 2-3 orders of magnitude less than those near the surface, upper tropospheric water vapor exerts an important influence on climate. What these models show is that for a given absolute increase in water vapor in the upper troposphere, the response or change in surface temperature is extremely disproportionate to the amount of water vapor. At present, considerable controversy exists over the nature of the vertical redistribution of water vapor in a changing climate, and particularly the distribution of water vapor in the upper troposphere. Understanding upper tropospheric moistening processes such as deep convection are therefore of prime importance in addressing the water vapor feedback question. Accurate measurements of the vertical and temporal variations of water vapor are essential for understanding atmospheric processes and hence model refinement.
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Bood, Joakim, Per-Erik Bengtsson i Marcus Aldén. "Non-Intrusive Temperature and Oxygen Concentration Measurements in a Catalytic Combustor Using Rotational Coherent Anti-Stokes Raman Spectroscopy". W ASME 1999 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/99-gt-114.

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Rotational CARS (Coherent anti-Stokes Raman Spectroscopy) was used to measure temperature and relative oxygen concentrations in the exhaust gas of a catalytic combustor. This laser technique has the general advantages of such techniques, i.e. possibility of performing in-situ measurements with high spatial and temporal resolution, and non-intrusiveness. Profiles of temperature and oxygen concentrations are presented for a full-load condition, and the measured temperatures are compared with calculated values. Of great importance for the results is the accuracy of the technique, and a sensitivity analysis is performed to test the temperature and oxygen concentration dependence on uncertainties in experimental parameters. It was shown that the accuracy of temperature and oxygen concentration could be improved by fitting the nonresonant susceptibility in the evaluation procedure. The measurements were performed as a project in the European gas turbine program AGATA with the aim to develop a catalytic combustor with ceramic structural components and producing low emissions of pollutants.
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Ghosh, Suchismita, Denis L. Nika, Evgenni P. Pokatilov, Irene Calizo i Alexander A. Balandin. "Extraordinary Thermal Conductivity of Graphene: Prospects of Thermal Management Applications". W 2010 14th International Heat Transfer Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ihtc14-22348.

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We have recently discovered experimentally that suspended graphene, which is an individual sheet of sp2-hybridized carbon bound in two dimensions (2D), reveal an extremely high thermal conductivity. The measurements were performed using a non-contact optical technique developed by us on the basis of Raman spectroscopy. A large number of graphene flakes were suspended across trenches in Si wafers and attached to heat sinks. The flakes were heated by the focused laser light in the middle of the suspended portion of graphene. The amount of laser power dissipated in graphene and corresponding local temperature rise were determined from the integrated intensity and spectral position of graphene’s Raman G mode. The position of the G peak as a function of the sample temperature was measured independently allowing the use of micro-Raman spectrometer as a “thermometer”. The experimental thermal conductivity values were in the range of ∼ 3000–5300 W/mK near room temperature (RT) and depended on the graphene flake sizes. The thermal conductivity of graphene is the highest among all materials known to date. In this review work we will describe the details of our measurement procedure and explain theoretically why the 2D thermal conductivity of graphene is higher than that of bulk graphite provided that the size of graphene flakes is sufficiently large. Our theory, which includes the phonon-mode dependent Gruneisen parameter and phonon scattering on edges and defects, gives results, which are in excellent agreement with the experiment. Superior thermal properties of graphene are beneficial for the proposed graphene electronic devices, and may pave the way for graphene’s thermal management applications.
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Jones, Paul M., Joachim Ahner, Christopher L. Platt, Huan Tang i Julius Hohlfeld. "Carbon Overcoat Loss From the Surface of a Heat Assisted Magnetic Storage Disk due to Laser Irradiation". W ASME 2013 Conference on Information Storage and Processing Systems. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/isps2013-2947.

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A pump-probe experimental technique that incorporated a 527nm wavelength pump laser and a 476nm probe laser was applied to a magnetic storage disk having a magnetic layer comprised of a FePt alloy and coated with a hydrogenated carbon overcoat (COC). The pump laser power was systematically increased while sweeping the applied field with an electromagnet to observe the temperature dependent magnetization, which is proportional to the change in the polarization of the reflected beam. In this way the laser power required to heat the media to the Curie temperature (Tc) was determined, with the Curie temperature of the media determined from a separate magnetometry measurement. Such a single point laser power-to-media temperature calibration allowed the determination of the media temperature over a small laser power range near Tc. The carbon over-coated FePt media was then irradiated for varying durations at temperatures pertinent to a Heat Assisted Magnetic Recording (HAMR) device [1]. The COC surface topography and carbon bonding structure within each irradiated zone was probed with AFM and micro-spot Raman. A subtle, systematic temperature and duration dependent change in the COC was observed. With increasing temperature and duration, the Raman D-peak became increasingly pronounced, signaling an increase of the sp2 (disorder) content in the film in the irradiated region. At incrementally higher temperatures, the loss of the carbon overcoat becomes apparent as a shallow depression in the COC film in the irradiated area. A clearer picture of the possible sensitivity and kinetics of the loss of COC on the HAMR media surface was obtained by measuring its loss over a range of irradiation temperatures and durations. The activation energy and COC loss rate were obtained and a possible mechanism for COC failure-loss was discussed within the bounds of the operating HAMR device [2].
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Raporty organizacyjne na temat "Temperature dependent Raman measurements"

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Lewis, William K., Nick G. Glumac i Eduardo G. Yukihara. Time-Dependent Temperature Measurements in Post-Detonation Combustion: Current State-of-the-Art Methods and Emerging Technologies. Fort Belvoir, VA: Defense Technical Information Center, marzec 2016. http://dx.doi.org/10.21236/ad1006208.

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Leveque, E., M. Zarea, R. Batisse i P. Roovers. IPC-BST-R01 Burst Strength of Gouges in Low Toughness Gas Transmission Pipes. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), wrzesień 2006. http://dx.doi.org/10.55274/r0011781.

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EPRG research aimed at establishing a limit on the toughness value that separates toughness-dependent from toughness-independent failure behavior. More specifically, one objective is to evaluate the toughness-dependent Battelle formula for burst resistance of gouges for (very) low toughness values. This mainly experimental project checks this behavior on several gas transmission pipes, a small diameter one, 150 mm, a medium diameter one, 350 mm, and a large diameter one, 900 mm. Pipe material is carefully characterized in terms of tensile properties, Charpy energy, and shear area. Then, based on the toughness independent criterion, a set of gouges is defined, of different depths/lengths, so as to span the different regions of the criterion, covering both short and long defects. These defects are manufactured by spark erosion, resulting in thin slits. Each such slit is incorporated into a vessel that is submitted to a burst test, with a number of additional measurements, like strain gauges on the pipe surface, a clip gauge et the center of the defect. For the small and medium sized pipes, temperature is also controlled during the test, to ensure it is as low as practically feasible, without heavy infrastructure. The results are interpreted both in terms of comparison with the criteria, and also in terms of analysis of the failure surface, to identify failure mechanisms.
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Friedman, Shmuel, Jon Wraith i Dani Or. Geometrical Considerations and Interfacial Processes Affecting Electromagnetic Measurement of Soil Water Content by TDR and Remote Sensing Methods. United States Department of Agriculture, 2002. http://dx.doi.org/10.32747/2002.7580679.bard.

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Time Domain Reflectometry (TDR) and other in-situ and remote sensing dielectric methods for determining the soil water content had become standard in both research and practice in the last two decades. Limitations of existing dielectric methods in some soils, and introduction of new agricultural measurement devices or approaches based on soil dielectric properties mandate improved understanding of the relationship between the measured effective permittivity (dielectric constant) and the soil water content. Mounting evidence indicates that consideration must be given not only to the volume fractions of soil constituents, as most mixing models assume, but also to soil attributes and ambient temperature in order to reduce errors in interpreting measured effective permittivities. The major objective of the present research project was to investigate the effects of the soil geometrical attributes and interfacial processes (bound water) on the effective permittivity of the soil, and to develop a theoretical frame for improved, soil-specific effective permittivity- water content calibration curves, which are based on easily attainable soil properties. After initializing the experimental investigation of the effective permittivity - water content relationship, we realized that the first step for water content determination by the Time Domain Reflectometry (TDR) method, namely, the TDR measurement of the soil effective permittivity still requires standardization and improvement, and we also made more efforts than originally planned towards this objective. The findings of the BARD project, related to these two consequential steps involved in TDR measurement of the soil water content, are expected to improve the accuracy of soil water content determination by existing in-situ and remote sensing dielectric methods and to help evaluate new water content sensors based on soil electrical properties. A more precise water content determination is expected to result in reduced irrigation levels, a matter which is beneficial first to American and Israeli farmers, and also to hydrologists and environmentalists dealing with production and assessment of contamination hazards of this progressively more precious natural resource. The improved understanding of the way the soil geometrical attributes affect its effective permittivity is expected to contribute to our understanding and predicting capability of other, related soil transport properties such as electrical and thermal conductivity, and diffusion coefficients of solutes and gas molecules. In addition, to the originally planned research activities we also investigated other related problems and made many contributions of short and longer terms benefits. These efforts include: Developing a method and a special TDR probe for using TDR systems to determine also the soil's matric potential; Developing a methodology for utilizing the thermodielectric effect, namely, the variation of the soil's effective permittivity with temperature, to evaluate its specific surface area; Developing a simple method for characterizing particle shape by measuring the repose angle of a granular material avalanching in water; Measurements and characterization of the pore scale, saturation degree - dependent anisotropy factor for electrical and hydraulic conductivities; Studying the dielectric properties of cereal grains towards improved determination of their water content. A reliable evaluation of the soil textural attributes (e.g. the specific surface area mentioned above) and its water content is essential for intensive irrigation and fertilization processes and within extensive precision agriculture management. The findings of the present research project are expected to improve the determination of cereal grain water content by on-line dielectric methods. A precise evaluation of grain water content is essential for pricing and evaluation of drying-before-storage requirements, issues involving energy savings and commercial aspects of major economic importance to the American agriculture. The results and methodologies developed within the above mentioned side studies are expected to be beneficial to also other industrial and environmental practices requiring the water content determination and characterization of granular materials.
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Brosh, Arieh, David Robertshaw, Yoav Aharoni, Zvi Holzer, Mario Gutman i Amichai Arieli. Estimation of Energy Expenditure of Free Living and Growing Domesticated Ruminants by Heart Rate Measurement. United States Department of Agriculture, kwiecień 2002. http://dx.doi.org/10.32747/2002.7580685.bard.

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Research objectives were: 1) To study the effect of diet energy density, level of exercise, thermal conditions and reproductive state on cardiovascular function as it relates to oxygen (O2) mobilization. 2) To validate the use of heart rate (HR) to predict energy expenditure (EE) of ruminants, by measuring and calculating the energy balance components at different productive and reproductive states. 3) To validate the use of HR to identify changes in the metabolizable energy (ME) and ME intake (MEI) of grazing ruminants. Background: The development of an effective method for the measurement of EE is essential for understanding the management of both grazing and confined feedlot animals. The use of HR as a method of estimating EE in free-ranging large ruminants has been limited by the availability of suitable field monitoring equipment and by the absence of empirical understanding of the relationship between cardiac function and metabolic rate. Recent developments in microelectronics provide a good opportunity to use small HR devices to monitor free-range animals. The estimation of O2 uptake (VO2) of animals from their HR has to be based upon a consistent relationship between HR and VO2. The question as to whether, or to what extent, feeding level, environmental conditions and reproductive state affect such a relationship is still unanswered. Studies on the basic physiology of O2 mobilization (in USA) and field and feedlot-based investigations (in Israel) covered a , variety of conditions in order to investigate the possibilities of using HR to estimate EE. In USA the physiological studies conducted using animals with implanted flow probes, show that: I) although stroke volume decreases during intense exercise, VO2 per one heart beat per kgBW0.75 (O2 Pulse, O2P) actually increases and measurement of EE by HR and constant O2P may underestimate VO2unless the slope of the regression relating to heart rate and VO2 is also determined, 2) alterations in VO2 associated with the level of feeding and the effects of feeding itself have no effect on O2P, 3) both pregnancy and lactation may increase blood volume, especially lactation; but they have no effect on O2P, 4) ambient temperature in the range of 15 to 25°C in the resting animal has no effect on O2P, and 5) severe heat stress, induced by exercise, elevates body temperature to a sufficient extent that 14% of cardiac output may be required to dissipate the heat generated by exercise rather than for O2 transport. However, this is an unusual situation and its affect on EE estimation in a freely grazing animal, especially when heart rate is monitored over several days, is minor. In Israel three experiments were carried out in the hot summer to define changes in O2P attributable to changes in the time of day or In the heat load. The animals used were lambs and young calves in the growing phase and highly yielding dairy cows. In the growing animals the time of day, or the heat load, affected HR and VO2, but had no effect on O2P. On the other hand, the O2P measured in lactating cows was affected by the heat load; this is similar to the finding in the USA study of sheep. Energy balance trials were conducted to compare MEI recovery by the retained energy (RE) and by EE as measured by HR and O2P. The trial hypothesis was that if HR reliably estimated EE, the MEI proportion to (EE+RE) would not be significantly different from 1.0. Beef cows along a year of their reproductive cycle and growing lambs were used. The MEI recoveries of both trials were not significantly different from 1.0, 1.062+0.026 and 0.957+0.024 respectively. The cows' reproductive state did not affect the O2P, which is similar to the finding in the USA study. Pasture ME content and animal variables such as HR, VO2, O2P and EE of cows on grazing and in confinement were measured throughout three years under twenty-nine combinations of herbage quality and cows' reproductive state. In twelve grazing states, individual faecal output (FO) was measured and MEI was calculated. Regression analyses of the EE and RE dependent on MEI were highly significant (P<0.001). The predicted values of EE at zero intake (78 kcal/kgBW0.75), were similar to those estimated by NRC (1984). The EE at maintenance condition of the grazing cows (EE=MEI, 125 kcal/kgBW0.75) which are in the range of 96.1 to 125.5 as presented by NRC (1996 pp 6-7) for beef cows. Average daily HR and EE were significantly increased by lactation, P<0.001 and P<0.02 respectively. Grazing ME significantly increased HR and EE, P<0.001 and P<0.00l respectively. In contradiction to the finding in confined ewes and cows, the O2P of the grazing cows was significantly affected by the combined treatments (P<0.00l ); this effect was significantly related to the diet ME (P<0.00l ) and consequently to the MEI (P<0.03). Grazing significantly increased O2P compared to confinement. So, when EE of grazing animals during a certain season of the year is estimated using the HR method, the O2P must be re measured whenever grazing ME changes. A high correlation (R2>0.96) of group average EE and of HR dependency on MEI was also found in confined cows, which were fed six different diets and in growing lambs on three diets. In conclusion, the studies conducted in USA and in Israel investigated in depth the physiological mechanisms of cardiovascular and O2 mobilization, and went on to investigate a wide variety of ruminant species, ages, reproductive states, diets ME, time of intake and time of day, and compared these variables under grazing and confinement conditions. From these combined studies we can conclude that EE can be determined from HR measurements during several days, multiplied by O2P measured over a short period of time (10-15 min). The study showed that RE could be determined during the growing phase without slaughtering. In the near future the development microelectronic devices will enable wide use of the HR method to determine EE and energy balance. It will open new scopes of physiological and agricultural research with minimizes strain on animals. The method also has a high potential as a tool for herd management.
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