EFFECTS OF FATLIQURING PROCESS ON LEATHERS COLOURED WITH IR REFLECTIVE DYES AND PIGMENTS

Directory of Open Access Journals (Sweden)

MUTLU Mehmet Mete

2017-05-01

Full Text Available Black coloured materials and consumer goods are known to be heating up more, because they absorb sun radiation more than light colours. This heating is a problem for the users for black automotive or motorcycle leathers and also for dark shoes and boots which are exposed to sun heat. Human vision system can distinguish visible colours between the wavelengths of 390-700 nm. So reflecting the sun radiation in the infrared area of radiation spectrum higher than 700nm, is a solution for heating problem without affecting the visible colour. For this reason IR reflective dyes and pigments are designed. A leading Leather Chemical Company has developed an IR reflecting dyeing system for leather keeping the dark coloured leathers cooler under sun radiation. Additionally in theory, fat and water content of leather affects its heating properties. In this study, effect of natural, synthetic and waterproof fatliquoring systems on heating properties of leathers coloured with IR reflective dyes and pigments are investigated.

Mid-IR absorption sensing of heavy water using a silicon-on-sapphire waveguide.

Science.gov (United States)

Singh, Neetesh; Casas-Bedoya, Alvaro; Hudson, Darren D; Read, Andrew; Mägi, Eric; Eggleton, Benjamin J

2016-12-15

We demonstrate a compact silicon-on-sapphire (SOS) strip waveguide sensor for mid-IR absorption spectroscopy. This device can be used for gas and liquid sensing, especially to detect chemically similar molecules and precisely characterize extremely absorptive liquids that are difficult to detect by conventional infrared transmission techniques. We reliably measure concentrations up to 0.25% of heavy water (D2O) in a D2O-H2O mixture at its maximum absorption band at around 4 μm. This complementary metal-oxide-semiconductor (CMOS) compatible SOS D2O sensor is promising for applications such as measuring body fat content or detection of coolant leakage in nuclear reactors.

Evaluation of MidIR fibre optic reflectance: Detection limit, reproducibility and binary mixture discrimination

Science.gov (United States)

Sessa, Clarimma; Bagán, Héctor; García, José Francisco

2013-11-01

MidIR fibre optic reflectance (MidIR-FORS) is a promising analytical technique in the field of science conservation, especially because it is non-destructive. Another advantage of MidIR-FORS is that the obtained information is representative, as a large amount of spectral data can be collected. Although the technique has a high potential and is almost routinely applied, its quality parameters have not been thoroughly studied in the specific application of analysis of artistic materials. The objective of this study is to evaluate the instrumental capabilities of MidIR-FORS for the analysis of artwork materials in terms of detection limit, reproducibility, and mixture characterisation. The study has been focused on oil easel painting and several paints of known composition have been analysed. Paint layers include blue pigments not only because of their important role along art history, but also because their physical and spectroscopic characteristics allow a better evaluation of the MidIR-FORS capabilities. The results of the analysis indicate that MidIR-FORS supplies a signal affected by different factors, such as the optical, morphological and physical properties of the surface, in addition to the composition of materials analysed. Consequently, the detection limits established are relatively high for artistic objects (Prussian blue - PB 2.1-6.5%; Phthalocyanine blue - Pht 6.3-10.2%; synthetic Ultramarine blue - UM 12.1%) and may therefore lead to an incomplete description of the artwork. Reproducibility of the technique over time and across surface has been determined. The results show that the major sources of dispersion are the heterogeneity of the pigments distribution, physical features, and band shape distortions. The total dispersion is around 4% for the most intense bands (oil) and increases up to 26% when weak or overlapped bands are considered (PB, Pht, UM). The application of different pre-treatments (cutoff of fibres absorption, Savizky-Golay smoothing

Temperature-dependent mid-IR absorption spectra of gaseous hydrocarbons

International Nuclear Information System (INIS)

Klingbeil, Adam E.; Jeffries, Jay B.; Hanson, Ronald K.

2007-01-01

Quantitative mid-IR absorption spectra (2500-3400 cm -1 ) for 12 pure hydrocarbon compounds are measured at temperatures ranging from 25 to 500 deg. C using an FTIR spectrometer. The hydrocarbons studied are n-pentane, n-heptane, n-dodecane, 2,2,4-trimethyl-pentane (iso-octane), 2-methyl-butane, 2-methyl-pentane, 2,4,4-trimethyl-1-pentene, 2-methyl-2-butene, propene, toluene, m-xylene, and ethylbenzene. Room-temperature measurements of neat hydrocarbon vapor were made with an instrument resolution of both 0.1 and 1 cm -1 (FWHM) to confirm that the high-resolution setting was required only to resolve the propene absorption spectrum while the spectra of the other hydrocarbons could be resolved with 1 cm -1 resolution. High-resolution (0.1 cm -1 ), room-temperature measurements of neat hydrocarbons were made at low pressure (∼1 Torr, 133 Pa) and compared to measurements of hydrocarbon/N 2 mixtures at atmospheric pressure to verify that no pressure broadening could be observed over this pressure range. The temperature was varied between 25 and 500 o C for atmospheric-pressure measurements of hydrocarbon/N 2 mixtures (X hydrocarbon ∼0.06-1.5%) and it was found that the absorption cross section shows simple temperature-dependent behavior for a fixed wavelength over this temperature range. Comparisons with previous FTIR data over a limited temperature range and with high-resolution laser absorption data over a wide temperature range show good agreement

Reflection effect of localized absorptive potential on non-resonant and resonant tunneling

International Nuclear Information System (INIS)

Rubio, A.; Kumar, N.

1992-06-01

The reflection due to absorptive potential (-iV i ) for resonant and non-resonant tunneling has been considered. We show that the effect of reflection leads to a non-monotonic dependence of absorption on the strength V i with a maximum absorption of typically 0.5. This has implications for the operation of resonant tunneling devices. General conceptual aspects of absorptive potentials are discussed. (author). 9 refs, 2 figs

Experimental investigation of integrated refrigeration system (IRS) with gas engine, compression chiller and absorption chiller

International Nuclear Information System (INIS)

Sun, Z.G.

2008-01-01

An integrated refrigeration system (IRS) with a gas engine, a vapor-compression chiller and an absorption chiller is set up and tested. The vapor-compression refrigeration cycle is operated directly by the gas engine. The waste heat from the gas engine operates the absorption refrigeration cycle, which provides additional cooling. The performance of the IRS is described. The cooling capacity of the IRS is about 596 kW, and primary energy ratio (PER) reaches 1.84 at air-conditioning rated conditions. The refrigerating capacity of the prototype increased and PER of prototype decreased with the increase of the gas engine speed. The gas engine speed was preferably regulated at part load condition in order to operate the prototype at high-energy efficiency. The refrigerating capacity and PER of the prototype increased with the increase of the outlet temperature of chilled water or the decrease of the inlet temperature of cooling water. The integrated refrigeration chiller in this work saves running costs as compared to the conventional refrigeration system by using the waste heat

Role of Bi promotion and solvent in platinum-catalyzed alcohol oxidation probed by in situ X-ray absorption and ATR-IR spectroscopy

DEFF Research Database (Denmark)

Mondelli, C.; Grunwaldt, Jan-Dierk; Ferri, D.

2010-01-01

the catalysts under working conditions using in situ X-ray absorption spectroscopy (XAS) and attenuated total reflection infrared spectroscopy (ATR-IR), aiming at uncovering the roles of the metal promoter and the reaction medium. XAS confirms that Bi is oxidized more easily than Pt, maintaining the catalytic...... surfaces than on step or kink sites. Side products, CO and benzoate species, appearing during the reaction reveal that the geometric suppression of undesired reactions does not occur to the same extent on Pt-based catalysts as on Pd, suggesting that decarbonylation of the produced aldehyde on Pt may occur...

Gas phase UV and IR absorption spectra of CxF2x+1CHO (x=1-4)

DEFF Research Database (Denmark)

Hashikawa, Y; Kawasaki, M; Waterland, RL

2004-01-01

The UV and IR spectra of CxF2x+1 CHO (x = 1-4) were investigated using computational and experimental techniques. CxF2x+1CHO (x = 1-4) have broad UV absorption features centered at 300-310 nm. The maximum absorption cross-section increases significantly and shifts slightly to the red with increased...

Study at high angular momentum of the reflection asymmetry in the 218 Ra transition nuclei

International Nuclear Information System (INIS)

Aiche, M.

1990-07-01

The investigations concerning the 218 Ra nuclei at high angular momentum are discussed. The aim of the study is to enlarge the knowledge on the octupolar phenomena and to analyse its evolution as a funcion of the angular momentum. The 218 Ra nuclei is obtained from the ( 14 C, 4n) reaction. The gamma angular distribution and the gamma-gamma coincidence were measured by means of the Chateau de Cristal multicounter. The reflection asymmetric mean field theory and the bosons interaction model were applied to analyze the data and obtain the structure at high angular moments. The results show the existence of dipole-octupole correlations in the nuclei [fr

Temperature-dependent absorption cross-section measurements of 1-butene (1-C4H8) in VUV and IR

KAUST Repository

Es-sebbar, Et-touhami

2013-01-01

Vacuum ultraviolet (VUV) and infrared (IR) absorption cross-section measurements of 1-butene (1-C4H8; CH2=CHCH2CH3; Butylene) are reported over the temperature range of 296-529K. The VUV measurements are performed between 115 and 205nm using synchrotron radiation as a tunable VUV light source. Fourier Transform Infrared (FTIR) spectroscopy is employed to measure absorption cross-section and band strengths in the IR region between 1.54 and 25μm (~6500-400cm-1). The measured room-temperature VUV and IR absorption cross-sections are compared with available literature data and are found to be in good agreement. The oscillator strength for the electronic transition (A1A\\'→X1A\\') around 150-205nm is determined to be 0.32±0.01.The gas temperature has a strong effect on both VUV and IR spectra. Measurements made in the VUV region show that the peak value of the band cross-section decreases and the background continuum increases with increasing gas temperature. This behavior is due to a change in the rotational and vibrational population distribution of 1-butene molecule. Similar changes in rotational population are observed in the IR spectra. Moreover, variation of the IR spectra with temperature is used to measure the enthalpy difference between syn and skew conformations of 1-butene and is found to be 0.24±0.03. kcal/mol, which is in excellent agreement with values reported in the literature. The measurements reported in this work will provide the much-needed spectroscopic information for the development of high-temperature quantitative diagnostics in combustion applications and validation of atmospheric chemistry models of extra-solar planets. © 2012 Elsevier Ltd.

N-annulated perylene fused porphyrins with enhanced near-IR absorption and emission

KAUST Repository

Jiao, Chongjun

2010-09-17

N-Annulated perylene fused porphyrins 1 and 2 were synthesized by oxidative dehydrogenation using a Sc(OTf)3/DDQ system. These newly synthesized hybrid molecules are highly soluble in organic solvents and exhibit remarkably intense near-IR absorption, as well as detectable photoluminescence quantum yields, all of which are comparable to or even exceed those of either meso-β doubly linked porphyrin dimer/trimer or bis/tri-N-annulated rylenes. © 2010 American Chemical Society.

Detecting infrared luminescence and non-chemical signaling of living cells: single cell mid-IR spectroscopy in cryogenic environments

Science.gov (United States)

Pereverzev, Sergey

2017-02-01

Many life-relevant interaction energies are in IR range, and it is reasonable to believe that some biochemical reactions inside cells can results in emission of IR photons. Cells can use this emission for non-chemical and non-electrical signaling. Detecting weak infrared radiation from live cells is complicated because of strong thermal radiation background and absorption of radiation by tissues. A microfluidic device with live cells inside a vacuum cryogenic environment should suppress this background, and thereby permit observation of live cell auto-luminescence or signaling in the IR regime. One can make IR-transparent windows not emitting in this range, so only the cell and a small amount of liquid around it will emit infrared radiation. Currently mid-IR spectroscopy of single cells requires the use of a synchrotron source to measure absorption or reflection spectra. Decreasing of thermal radiation background will allow absorption and reflection spectroscopy of cells without using synchrotron light. Moreover, cell auto-luminescence can be directly measured. The complete absence of thermal background radiation for cryogenically cooled samples allows the use IR photon-sensitive detectors and obtaining single molecule sensitivity in IR photo-luminescence measurements. Due to low photon energies, photo-luminescence measurements will be non-distractive for pressures samples. The technique described here is based upon US patent 9366574.

Attenuated total reflection design for in situ FT-IR spectroelectrochemical studies

International Nuclear Information System (INIS)

Visser, Hendrik; Curtright, Aimee E.; McCusker, James K.; Sauer, Kenneth

2000-01-01

A versatile spectroelectrochemical apparatus is introduced to study the changes in IR spectra of organic and inorganic compounds upon oxidation or reduction. The design is based on an attenuated total reflection (ATR) device, which permits the study of a wide spectral range of 16,700 cm-1 (600 nm) - 250 cm-1 with a small opaque region of 2250 - 1900 cm-1. In addition, an IR data collection protocol is introduced to deal with electrochemically non-reversible background signals. This method is tested with ferrocene in acetonitrile, producing results that agree with those in the literature

WATER ABSORPTION FROM GAS VERY NEAR THE MASSIVE PROTOSTAR AFGL 2136 IRS 1

International Nuclear Information System (INIS)

Indriolo, Nick; Neufeld, D. A.; Seifahrt, A.; Richter, M. J.

2013-01-01

We present ground-based observations of the ν 1 and ν 3 fundamental bands of H 2 O toward the massive protostar AFGL 2136 IRS 1, identifying absorption features due to 47 different ro-vibrational transitions between 2.468 μm and 2.561 μm. Analysis of these features indicates the absorption arises in warm (T = 506 ± 25 K), very dense (n(H 2 ) > 5 × 10 9 cm –3 ) gas, suggesting an origin close to the central protostar. The total column density of warm water is estimated to be N(H 2 O) = (1.02 ± 0.02) × 10 19 cm –2 , giving a relative abundance of N(H 2 O)/N(H 2 ) ≈ 10 –4 . Our study represents the first extensive use of water vapor absorption lines in the near infrared, and demonstrates the utility of such observations in deriving physical parameters

Diffuse reflectance relations based on diffusion dipole theory for large absorption and reduced scattering.

Science.gov (United States)

Bremmer, Rolf H; van Gemert, Martin J C; Faber, Dirk J; van Leeuwen, Ton G; Aalders, Maurice C G

2013-08-01

Diffuse reflectance spectra are used to determine the optical properties of biological samples. In medicine and forensic science, the turbid objects under study often possess large absorption and/or scattering properties. However, data analysis is frequently based on the diffusion approximation to the radiative transfer equation, implying that it is limited to tissues where the reduced scattering coefficient dominates over the absorption coefficient. Nevertheless, up to absorption coefficients of 20  mm-1 at reduced scattering coefficients of 1 and 11.5  mm-1, we observed excellent agreement (r2=0.994) between reflectance measurements of phantoms and the diffuse reflectance equation proposed by Zonios et al. [Appl. Opt.38, 6628-6637 (1999)], derived as an approximation to one of the diffusion dipole equations of Farrell et al. [Med. Phys.19, 879-888 (1992)]. However, two parameters were fitted to all phantom experiments, including strongly absorbing samples, implying that the reflectance equation differs from diffusion theory. Yet, the exact diffusion dipole approximation at high reduced scattering and absorption also showed agreement with the phantom measurements. The mathematical structure of the diffuse reflectance relation used, derived by Zonios et al. [Appl. Opt.38, 6628-6637 (1999)], explains this observation. In conclusion, diffuse reflectance relations derived as an approximation to the diffusion dipole theory of Farrell et al. can analyze reflectance ratios accurately, even for much larger absorption than reduced scattering coefficients. This allows calibration of fiber-probe set-ups so that the object's diffuse reflectance can be related to its absorption even when large. These findings will greatly expand the application of diffuse reflection spectroscopy. In medicine, it may allow the use of blue/green wavelengths and measurements on whole blood, and in forensic science, it may allow inclusion of objects such as blood stains and cloth at crime

The investigation of hydrogens bonds between sulphur-bearing heterocyclic and proton-donor compounds by IR absorption spectra

International Nuclear Information System (INIS)

Narziev, B.N.; Nurulloev, M.; Makhkambaev, D.

1982-01-01

In this article the results of intermolecular interaction study of sulfur-containing heterocyclic (thiophene, thiophane) and proton-donar (water, alcohol, carbonic acids, chlorophon) molecules for measuring of IR spectrum absorption of protondonar compounds in soluted shape are presented

Interlayer interactions in absorption and reflection spectra of bismuth HTSC crystals

International Nuclear Information System (INIS)

Kruchinin, S.P.; Yaremko, A.M.

1992-01-01

The HTSC reflection and absorption optic spectra peculiarities are analysed in the paper on the basis of bismuth and thallium. The approach suggested takes into account the complex character of crystals structure, possible localization of excitations in the isolated layers and further excitations exchange due to the interlayer interaction between cuprate (Cu O) and quasi-degenerate bismuth layers (Bi O/3pO). The expressions for the excitation and intensity energies of the corresponding transitions are obtained. It is shown that only part of excitations whose number is determined by the number of layers in the unit cell will be manifest in optical reflection and absorption spectra. The experimental results on spectral dependence of crystal reflection coefficients are analysed

Electroactive semi-interpenetrating polymer networks architecture with tunable IR reflectivity

Science.gov (United States)

Chevrot, C.; Teyssié, D.; Verge, P.; Goujon, L.; Tran-Van, F.; Vidal, F.; Aubert, P. H.; Peralta, S.; Sauques, L.

2011-04-01

A promising alternative of multi-layered devices showing electrochromic properties results from the design of a self-supported semi-interpenetrating polymer network (semi-IPN) including an electronic conductive polymer (ECP) formed within. The formation of the ECP in the network has already been described by oxidative polymerization using iron trichloride as an oxidant and leading to conducting semi-IPN with mixed electronic and ionic conductivities as well as convenient mechanical properties. This presentation relates to the elaboration of such semi-IPN using polyethyleneoxide (PEO) network or a PEO/NBR (Nitrile Butadiene Rubber) IPN in which a linear poly (3,4-ethylenedioxythiophene) (PEDOT) is formed symmetrically and selectively as very thin layers very next to the two main faces of the film matrix. PEO/PEDOT semi-IPNs lead to interesting optical reflective properties in the IR between 0.8 and 25 μm. Reflectance contrasts up to 35 % is observed when, after swelling in an ionic liquid, a low voltage is applied between the two main faces of the film. However the low flexibility and brittleness of the film and a slow degradation in air at temperature up from 60°C prompted to replace the PEO matrix by a flexible PEO/NBR IPN one. Indeed, the combination of NBR and PEO in an IPN leads to materials possessing flexible properties, good ionic conductivity at 25°C as well as a better resistance to thermal ageing. Finally, NBR/PEO/PEDOT semi-IPNs allow observing comparable reflectance contrast in the IR range than those shown by PEO/PEDOT semi-IPNs.

Smulkaus ir vidutinio verslo konkurencingumas Lietuvoje

OpenAIRE

Vijeikis, Juozas; Makštutis, Antanas

2009-01-01

Straipsnio mokslinė problema, naujumas ir aktualumas. Konkurencingumas kaip įmonių efektyvios veiklos reiškinys yra aktualus šalies verslo gyvenime vykdant darnios ekonominės plėtros politiką. Ši politika kaip problema smulkaus ir vidutinio verslo (SVV) plėtrai ir konkurencingumui didinti nėra sistemiškai ištirta ir aprašyta Lietuvos sąlygomis mokslinėje ir praktinėje literatūroje. Vienas svarbiausių veiksnių, siekiant spartaus ekonominio augimo, yra darnios verslininkystės plėtra Lietuvoje n...

Darbo metu susenėjusių ir po suvirinimo termiškai apdorotų plieno 5 % Cr-0,5 % Mo virintinių jungčių struktūra ir savybės

Directory of Open Access Journals (Sweden)

Vigantas KUMŠLYTIS

2012-06-01

Full Text Available Straipsnyje nagrinėjamos suvirintos ir termiškai apdorotos chromo ir molibdeno (5 % Cr – 0,5 % Mo grupės plieno vamzdžių jungtys. Taip pat pateikiami ir palyginami ilgą laiką aukštoje temperatūroje eksploatuoto ir naujo chromo ir molibdeno plieno vamzdžio struktūra ir mechaninių savybių tyrimai. Eksploatuoto metalo tyrimams buvo panaudotas 530 °C temperatūroje 100 000 valandų dirbęs plieninis vamzdis. Tyrimais siekiama nustatyti 5 % Cr – 0,5% Mo grupės plienų suvirintųjų jungčių mechaninių savybių ir terminio apdorojimo parametrų tarpusavio priklausomybes. Atlikti suvirintų bandinių struktūros radiografiniai, mechaninių savybių, lūžių analizės ir mikrostruktūrų tyrimai. Nustatyta, kad chromo ir molibdeno plienų virintinių jungčių vidiniams įtempiams mažinti turi būti taikomas tik terminis apdorojimas. Kiti įtempių mažinimo metodai šiems plienams yra nepriimtini. Nustatyta, kad 5 % Cr – 0,5 % Mo plienų virintinių jungčių terminio apdorojimo temperatūros ir laiko parametro P reikšmė neturi viršyti 20,5. Viršijus šią reikšmę vyksta struktūros degradacijos procesas, karbidai pamažu transformuojasi į M23C6 karbidus, koaguliuoja ferito grūdelių ribose, sudaro karbidų kolonijas ar jungiasi į ilgus vientisus junginius. Smulkių, dispersiškų karbidų struktūroje nelieka. Taip pat mažėja jungties metalo takumo stipris ir smūginis tąsumas.DOI: http://dx.doi.org/10.5755/j01.ms.18.2.1911

Reversible unidirectional reflection and absorption of PT-symmetry structure under electro-optical modulation

Science.gov (United States)

Fang, Yun-tuan; Zhang, Yi-chi; Xia, Jing

2018-06-01

In order to obtain tunable unidirectional device, we assumed an ideal periodic layered Parity-Time (PT) symmetry structure inserted by doped LiNbO3 (LN) interlayers. LN is a typical electro-optical material of which the refractive index depends on the external electric field. In our work, we theoretically investigate the modulation effect of the external electric field on the transmittance and reflectance of the structure through numerical method. Through selected structural parameters, the one-way enhanced reflection and high absorption (above 0.9) behaviors are found. Within a special frequency band (not a single frequency), our theoretical model performs enhanced reflection in one incidence direction and high absorption in the other direction. Furthermore, the directions of enhanced reflection and absorption can be reversed through reversing the direction of applied electric field. Such structure with reversible properties has the potential in designing new optical devices.

Temperature-dependent absorption cross-section measurements of 1-butene (1-C4H8) in VUV and IR

KAUST Repository

Es-sebbar, Et-touhami; Bé nilan, Yves; Farooq, Aamir

2013-01-01

synchrotron radiation as a tunable VUV light source. Fourier Transform Infrared (FTIR) spectroscopy is employed to measure absorption cross-section and band strengths in the IR region between 1.54 and 25μm (~6500-400cm-1). The measured room-temperature VUV

Developing Integral Review:IR Editors Reflect on Meta-theory,the Concept of

Directory of Open Access Journals (Sweden)

Russ Volckmann

2007-12-01

Full Text Available Over the past three years our journey as editors of Integral Review has been full of rich learning. The processes of providing authors with feedback, going over reviews of articles as well as writing ourselves have all contributed to our growth. The primary forum for this learning has been the many conversations amongst us to deal with the various issues that arise in publishing IR. Our intention in this brief piece is to share some of our reflections on this learning journey with you. These will take the form of contributions/reflections from individual editors, allowing us to share with you the particular issues we feel of value in this process.By writing these short pieces, we aim to provide additional resources for understanding how IR works. While we have guidelines and criteria for submissions on our website, it seems that narrative voices from individuals may add some flesh to them. Relating how we perceive issues around writing for an “integral” journal offers a supplement for engaging these criteria, and will hopefully bring them to life. As well, we hope that our writing provides insights into how and what we think about issues relevant to IR’s mission. These pieces reflect the unique voices we have as editors of Integral Review, and demonstrate some of the thinking and passions behind this journal.

On-site Determination of Trace Arsenic by Reflection-Absorption Colorimetry of Molybdenum Blue Collected on a Membrane Filter.

Science.gov (United States)

Hasegawa, Yuya; Suzuki, Yasutada; Kawakubo, Susumu

2017-01-01

An on-site determination method for trace arsenic has been developed by collecting it as molybdenum blue (MB) in the presence of tetradecyldimethylbenzylammonium chloride on a mixed cellulose ester membrane filter and by measuring reflection absorbance (RA) of MB on the filter using a laboratory-made palm-top size reflection-absorbance colorimeter with a red light-emitting diode. The value of RA was proportional to the amount of arsenic up to 0.5 μg with a detection limit of 0.01 μg. The proposed method was successfully applied to soil extract and hot-spring water samples.

Development of paints with infrared radiation reflective properties

Directory of Open Access Journals (Sweden)

Eliane Coser

2015-06-01

Full Text Available AbstractLarge buildings situated in hot regions of the Globe need to be agreeable to their residents. Air conditioning is extensively used to make these buildings comfortable, with consequent energy consumption. Absorption of solar visible and infrared radiations are responsible for heating objects on the surface of the Earth, including houses and buildings. To avoid excessive energy consumption, it is possible to use coatings formulated with special pigments that are able to reflect the radiation in the near- infrared, NIR, spectrum. To evaluate this phenomenon an experimental study about the reflectivity of paints containing infrared-reflective pigments has been made. By irradiating with an IR source and by measuring the surface temperatures of the samples we evaluated: color according to ASTM D 2244-14, UV/VIS/NIR reflectance according to ASTM E 903-12 and thermal performance. Additionally, the spectral reflectance and the IR emittance were measured and the solar reflectance of the samples were calculated. The results showed that plates coated with paints containing IR-reflecting pigments displayed lower air temperature on the opposite side as compared to conventional coatings, indicating that they can be effective to reflect NIR and decrease the temperature of buildings when used in roofs and walls.

A first principle study for the adsorption and absorption of carbon atom and the CO dissociation on Ir(100) surface

Science.gov (United States)

Erikat, I. A.; Hamad, B. A.

2013-11-01

We employ density functional theory to examine the adsorption and absorption of carbon atom as well as the dissociation of carbon monoxide on Ir(100) surface. We find that carbon atoms bind strongly with Ir(100) surface and prefer the high coordination hollow site for all coverages. In the case of 0.75 ML coverage of carbon, we obtain a bridging metal structure due to the balance between Ir-C and Ir-Ir interactions. In the subsurface region, the carbon atom prefers the octahedral site of Ir(100) surface. We find large diffusion barrier for carbon atom into Ir(100) surface (2.70 eV) due to the strong bonding between carbon atom and Ir(100) surface, whereas we find a very small segregation barrier (0.22 eV) from subsurface to the surface. The minimum energy path and energy barrier for the dissociation of CO on Ir(100) surface are obtained by using climbing image nudge elastic band. The energy barrier of CO dissociation on Ir(100) surface is found to be 3.01 eV, which is appreciably larger than the association energy (1.61 eV) of this molecule.

Optinės holografijos metodai ir jų taikymas

OpenAIRE

Mindaugas ANDRULEVIČIUS

2011-01-01

Optinė holografija vis dažniau naudojama ne tik vaizdams  įrašyti bei atkurti, bet ir įvairiose srityse, nesusijusiose su vaizdų įrašymu. Ypač plačiai pastaruoju metu holografiniai metodai taikomi gaminių autentiškumo nustatymo ir dokumentų apsaugos priemonėse. Holografijos metodų populiarumą nulėmė nuolatos didėjantis apsaugos priemonių poreikis, nedidelė holografinių apsaugos priemonių savikaina bei gana didelis apsaugos patikimumas. Šiame darbe apžvelgiami ...

Determination of 226Ra and 228Ra in surface seawater around Sagami bay and its vicinity

International Nuclear Information System (INIS)

Nakano-Ohta, T.; Kubota, T.; Mahara, Y.; Yoshikawa, M.; Sato, J.

2006-01-01

Activity ratios of 228 Ra/ 226 Ra in surface seawaters were observed at 5 ports of Izu-Oshima, Ajiro port of Sagami bay and Umizuri park of Tokyo bay. The 228 Ra/ 226 Ra activity ratio in surface seawaters were from 0.2 to 0.7 for Izu-Oshima, from 0.2 to 0.7 for Ajiro port and from 0.6 to 0.8 for Tokyo bay. The activity ratio in surface seawaters of Izu-Oshima and Atami of Sagami bay showed lower in spring and highly in autumn, while narrow variation pattern was observed in Umizuri park of Tokyo bay. The observed variation patterns of 228 Ra/ 226 Ra in surface seawaters at Izu-oshima, Ajiro park and Umizuri park may be reflected by difference of contribution from amount of seawater far off coast with low 228 Ra concentration. (author)

New High-Resolution Absorption Cross-Section Measurements of HCFC-142B in the Mid-Ir

Science.gov (United States)

Le Bris, Karine; Strong, Kimberly; Melo, Stella

2009-06-01

HCFC-142b (1-chloro-1,1-difluoroethane) is a temporary substitute for ozone-depleting chlorofluorocarbons (CFCs). However, due to its high absorption cross-sections in the mid-IR, HCFC-142b is also a highly potent greenhouse gas, now detectable from space by satellite missions. So far, the accuracy of the retrieval has been limited by the lack of reference data in a range of temperatures compatible with atmospheric observations. We present new absorption cross section measurements of HCFC-142b at high-resolution (0.02 cm^{-1}) from 223 K to 283 K in the 600 cm^{-1}- 4000 cm^{-1} spectral window. The composite spectra are calculated for each temperature from a set of acquisitions at different pressures by Fourier transform spectroscopy.

Values of soil-plant transfer factor of 226Ra and 228Ra: agricultural areas versus areas of high natural radioactivity

International Nuclear Information System (INIS)

Wasserman, Maria Angelica; Lauria, Dejanira; Perez, Daniel Vidal; Schuch, Luiz Alexandre; Zago, Ari

2000-01-01

In this work, soil to plant transfer factor of 226 Ra and 228 Ra obtained in areas of traditional agricultural practices varied as a function of the considered cultivated species but little variation was observed as a function of the soil type. Beans and soybeans presented more important absorption than cereals (corn, rice and wheat). In our work legumes (bean and soybean) presented transfer factors up to one order of magnitude higher than average values for regions where natural radioactivity is high. On the other hand, the results for cereals did not presented such clear differences. It can be concluded that cultural inputs of 226 Ra and 228 Ra are occurring in agricultural areas, but few species can concentrate it. The transfer factor values obtained in this work for 226 Ra and 228 Ra can be applied in risk assessment models. (author)

In Situ Nondestructive Analysis of Kalanchoe pinnata Leaf Surface Structure by Polarization-Modulation Infrared Reflection-Absorption Spectroscopy.

Science.gov (United States)

Hama, Tetsuya; Kouchi, Akira; Watanabe, Naoki; Enami, Shinichi; Shimoaka, Takafumi; Hasegawa, Takeshi

2017-12-14

The outermost surface of the leaves of land plants is covered with a lipid membrane called the cuticle that protects against various stress factors. Probing the molecular-level structure of the intact cuticle is highly desirable for understanding its multifunctional properties. We report the in situ characterization of the surface structure of Kalanchoe pinnata leaves using polarization-modulation infrared reflection-absorption spectroscopy (PM-IRRAS). Without sample pretreatment, PM-IRRAS measures the IR spectra of the leaf cuticle of a potted K. pinnata plant. The peak position of the CH 2 -related modes shows that the cuticular waxes on the leaf surface are mainly crystalline, and the alkyl chains are highly packed in an all-trans zigzag conformation. The surface selection rule of PM-IRRAS revealed the average orientation of the cuticular molecules, as indicated by the positive and negative signals of the IR peaks. This unique property of PM-IRRAS revealed that the alkyl chains of the waxes and the main chains of polysaccharides are oriented almost perpendicular to the leaf surface. The nondestructive, background-free, and environmental gas-free nature of PM-IRRAS allows the structure and chemistry of the leaf cuticle to be studied directly in its native environment.

Values of soil-plant transfer factor of {sup 226}Ra and {sup 228}Ra: agricultural areas versus areas of high natural radioactivity; Valores de fator de transferencia solo-planta do {sup 226}Ra e {sup 228}Ra: areas agricolas versus areas de radioatividade natural elevada

Energy Technology Data Exchange (ETDEWEB)

Wasserman, Maria Angelica; Lauria, Dejanira [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil); Perez, Daniel Vidal [Empresa Brasileira de Pesquisa Agropecuaria, Rio de Janeiro, RJ (Brazil). Centro Nacional de Pesquisa de Solos; Schuch, Luiz Alexandre [Santa Maria Univ., RS (Brazil). Dept. de Fisica; Zago, Ari [Santa Maria Univ., RS (Brazil). Dept. de Solos

2000-07-01

In this work, soil to plant transfer factor of {sup 226}Ra and {sup 228}Ra obtained in areas of traditional agricultural practices varied as a function of the considered cultivated species but little variation was observed as a function of the soil type. Beans and soybeans presented more important absorption than cereals (corn, rice and wheat). In our work legumes (bean and soybean) presented transfer factors up to one order of magnitude higher than average values for regions where natural radioactivity is high. On the other hand, the results for cereals did not presented such clear differences. It can be concluded that cultural inputs of {sup 226}Ra and {sup 228}Ra are occurring in agricultural areas, but few species can concentrate it. The transfer factor values obtained in this work for {sup 226}Ra and {sup 228}Ra can be applied in risk assessment models. (author)

A first principle study for the adsorption and absorption of carbon atom and the CO dissociation on Ir(100) surface

Energy Technology Data Exchange (ETDEWEB)

Erikat, I. A., E-mail: ihsanas@yahoo.com [Department of Physics, Jerash University, Jerash-26150 (Jordan); Hamad, B. A. [Department of Physics, The University of Jordan, Amman-11942 (Jordan)

2013-11-07

We employ density functional theory to examine the adsorption and absorption of carbon atom as well as the dissociation of carbon monoxide on Ir(100) surface. We find that carbon atoms bind strongly with Ir(100) surface and prefer the high coordination hollow site for all coverages. In the case of 0.75 ML coverage of carbon, we obtain a bridging metal structure due to the balance between Ir–C and Ir–Ir interactions. In the subsurface region, the carbon atom prefers the octahedral site of Ir(100) surface. We find large diffusion barrier for carbon atom into Ir(100) surface (2.70 eV) due to the strong bonding between carbon atom and Ir(100) surface, whereas we find a very small segregation barrier (0.22 eV) from subsurface to the surface. The minimum energy path and energy barrier for the dissociation of CO on Ir(100) surface are obtained by using climbing image nudge elastic band. The energy barrier of CO dissociation on Ir(100) surface is found to be 3.01 eV, which is appreciably larger than the association energy (1.61 eV) of this molecule.

A first principle study for the adsorption and absorption of carbon atom and the CO dissociation on Ir(100) surface

International Nuclear Information System (INIS)

Erikat, I. A.; Hamad, B. A.

2013-01-01

We employ density functional theory to examine the adsorption and absorption of carbon atom as well as the dissociation of carbon monoxide on Ir(100) surface. We find that carbon atoms bind strongly with Ir(100) surface and prefer the high coordination hollow site for all coverages. In the case of 0.75 ML coverage of carbon, we obtain a bridging metal structure due to the balance between Ir–C and Ir–Ir interactions. In the subsurface region, the carbon atom prefers the octahedral site of Ir(100) surface. We find large diffusion barrier for carbon atom into Ir(100) surface (2.70 eV) due to the strong bonding between carbon atom and Ir(100) surface, whereas we find a very small segregation barrier (0.22 eV) from subsurface to the surface. The minimum energy path and energy barrier for the dissociation of CO on Ir(100) surface are obtained by using climbing image nudge elastic band. The energy barrier of CO dissociation on Ir(100) surface is found to be 3.01 eV, which is appreciably larger than the association energy (1.61 eV) of this molecule

Density, ultrasound velocity, acoustic impedance, reflection and absorption coefficient determination of liquids via multiple reflection method.

Science.gov (United States)

Hoche, S; Hussein, M A; Becker, T

2015-03-01

The accuracy of density, reflection coefficient, and acoustic impedance determination via multiple reflection method was validated experimentally. The ternary system water-maltose-ethanol was used to execute a systematic, temperature dependent study over a wide range of densities and viscosities aiming an application as inline sensor in beverage industries. The validation results of the presented method and setup show root mean square errors of: 1.201E-3 g cm(-3) (±0.12%) density, 0.515E-3 (0.15%) reflection coefficient and 1.851E+3 kg s(-1) m(-2) (0.12%) specific acoustic impedance. The results of the diffraction corrected absorption showed an average standard deviation of only 0.12%. It was found that the absorption change shows a good correlation to concentration variations and may be useful for laboratory analysis of sufficiently pure liquids. The main part of the observed errors can be explained by the observed noise, temperature variation and the low signal resolution of 50 MHz. In particular, the poor signal-to-noise ratio of the second reflector echo was found to be a main accuracy limitation. Concerning the investigation of liquids the unstable properties of the reference material PMMA, due to hygroscopicity, were identified to be an additional, unpredictable source of uncertainty. While dimensional changes can be considered by adequate methodology, the impact of the time and temperature dependent water absorption on relevant reference properties like the buffer's sound velocity and density could not be considered and may explain part of the observed deviations. Copyright © 2014 Elsevier B.V. All rights reserved.

Study on IR Properties of Reduced Graphene Oxide

Science.gov (United States)

Ma, Deyue; Li, Xiaoxia; Guo, Yuxiang; Zeng, Yurun

2018-01-01

Firstly, the reduced graphene oxide was prepared by modified hummer method and characterized. Then, the complex refractive index of reduced graphene oxide in IR band was tested and its IR absorption and radiation properties were researched by correlated calculation. The results show that reduced graphene oxide prepared by hummer method are multilayered graphene with defects and functional groups on its surface. Its absorption in near and far IR bands is strong, but it’s weaker in middle IR band. At the IR atmosphere Window, its normal spectral emissivity decreases with wavelength increasing, and its total normal spectral emissivity in 3 ∼ 5μm and 8 ∼ 14μm are 0.75 and 0.625, respectively. Therefore, reduced graphene oxide can be used as IR absorption and coating materials and have a great potential in microwave and infrared compatible materials.

Determination of electromagnetic absorption parameters by reflection measurements

International Nuclear Information System (INIS)

Vittitoe, C.N.

1975-09-01

The method described is for determining the electromagnetic absorption parameters of a material by measuring the optical reflection from a thick sample. With linearly polarized incident light (both perpendicular to and parallel to the plane of incidence), the ratio of the reflected intensities at three or more angles of incidence offers promise for determining the complex index of refraction of a material for a broad range of parameter values. The method may be applicable to molten materials, such as UO 2 , where high temperatures cause corrosion and containment difficulties. A method is given for extending the data to neighboring frequencies. Use of the method was successful for all portions of the complex index of refraction plane except for small values of the extinction coefficient

Attenuated total reflectance-FT-IR spectroscopy for gunshot residue analysis: potential for ammunition determination.

Science.gov (United States)

Bueno, Justin; Sikirzhytski, Vitali; Lednev, Igor K

2013-08-06

The ability to link a suspect to a particular shooting incident is a principal task for many forensic investigators. Here, we attempt to achieve this goal by analysis of gunshot residue (GSR) through the use of attenuated total reflectance (ATR) Fourier transform infrared spectroscopy (FT-IR) combined with statistical analysis. The firearm discharge process is analogous to a complex chemical process. Therefore, the products of this process (GSR) will vary based upon numerous factors, including the specific combination of the firearm and ammunition which was discharged. Differentiation of FT-IR data, collected from GSR particles originating from three different firearm-ammunition combinations (0.38 in., 0.40 in., and 9 mm calibers), was achieved using projection to latent structures discriminant analysis (PLS-DA). The technique was cross (leave-one-out), both internally and externally, validated. External validation was achieved via assignment (caliber identification) of unknown FT-IR spectra from unknown GSR particles. The results demonstrate great potential for ATR-FT-IR spectroscopic analysis of GSR for forensic purposes.

Pamokslo ir eseistikos sąveika Juliaus Sasnausko ir Giedrės Kazlauskaitės eseistikoje

OpenAIRE

Skirmantienė, Daiva

2010-01-01

Jaunosios kartos rašytojų kunigo pamokslininko Juliaus Sasnausko ir pasaulietės Giedrės Kazlauskaitės kūrybos semantinį ir įdėjinį lauką padeda suprasti teologinės literatūros ir literatūrinės teologijos sąveika. Teologinių prasmių paieška jų tekstuose atliepia šiuolaikinio žmogaus pastangas per literatūrą, skelbiančią gyvenamojo laikotarpio aktualijas, rasti kelią į tam tikras krikščioniškąsias tiesas ir bandyti reflektuoti savo tikėjimą bei analizuoti išganymo istoriją. Autorių kūryo...

IR spectroscopy at the ITO-organic interface

Energy Technology Data Exchange (ETDEWEB)

Alt, Milan [Karlsruher Institut fuer Technologie, Karlsruhe (Germany); Shazada, Ahmad [Max-Planck Institut fuer Polymerforschung, Mainz (Germany); Tamanai, Akemi; Trollmann, Jens; Glaser, Tobias; Beck, Sebastian; Tengeler, Sven; Pucci, Annemarie [Kirchhoff-Institut fuer Physik, Heidelberg (Germany)

2012-07-01

Thin films of P3HT have been prepared by spin coating and electrooxidative polymerization on platinum- and ITO-coated substrates. Additionally, P3HT-films on silicon substrates have been prepared by spin coating only. The measured IR spectra of the spin coated films allowed for an elaboration of a detailed optical model for P3HT, which has been used to simulate IR reflection-absorption spectra on ITO and Pt substrates. Comparison of simulated spectra with measurements revealed no substrate influence on the IR spectra for the spincoated films. In case of spincoated P3HT-films on ITO-substrate, the obtained IR spectra correspond to simulation data very well up to 6000 wavenumbers. In the electropolymerized P3HT films we have identified residuals of the electrolyte ionic liquid, acting as dopand for P3HT. While IR spectra of the electropolymerized P3HT films on Pt substrate could be explained reasonably well as a superposition of chemically doped P3HT and the ionic electrolyte, the IR spectra of electropolymerized P3HT films on ITO substrates showed strongly deposition-time dependent deviations. These were most likely related to varying properties of the ITO surface between reference and sample measurement due to an interaction of ITO and the electrolyte at the film-substrate interface.

Study of wide band-gap crystal LiCaAlF6 by IR-reflection spectroscopy and ab initio calculations

International Nuclear Information System (INIS)

Novikova, N.N.; Klimin, S.A.; Mavrin, B.N.

2017-01-01

Polarized IR-reflection spectra and results of ab initio calculations of vibrational and electronic properties of LiCaAlF6 single crystal are presented. It is shown that the crystal band gap is direct. Experimental and theoretical parameters are obtained for dipole-active and all phonons, respectively, including silent modes. Experimental IR-reflection and Raman spectra are well described in the frame of results obtained by ab initio calculations. The peculiarities are discussed concerning the structure of electronic bands, the interatomic interactions, the character of lattice vibrations, and the phonon dispersion.

A reflective-backing-free metamaterial absorber with broadband response

Directory of Open Access Journals (Sweden)

Cuilian Xu

2017-06-01

Full Text Available In this paper, we propose a polarization-independent and broadband perfect infrared (IR metamaterial absorber (MA without reflective backing. The proposed absorber is a periodic meta-atom array consisting of metal-dielectric-multilayer truncated cones which can absorb 80% EM wave from 50.70 to 81.87THz, while transmit 80% EM wave from 0 to 37.71THz. With the decreasing of frequency, the transmissivity increases, which is close to 100% from 0 to 5THz. We can broaden the absorption bandwidth of the MA by cascading multi-layers truncated cones. Furthermore, the proposed IR MA promises to be one desirable stealth material for radar-IR compatibility.

Reflection and absorption of ordinary waves in an inhomogeneous plasma

International Nuclear Information System (INIS)

Croci, R.

1990-11-01

This study treats the system of Vlasov and Maxwell equations for the Fourier transform in space and time of a plasma referred to Cartesian coordinates with the coordinate z parallel to the uniform equilibrium magnetic field with the equilibrium plasma density dependent on ηx, where η is a parameter. The k y component of the wave vector is taken equal to zero, whereas k z is different from zero. When the interaction of ordinary and extraordinary waves is neglected, the Fourier transform of the electric field of the ordinary waves obeys a homogeneous integral equation with principal part integrals, which is solved in the case of weak absorption and sufficiently small η (essentially smaller than vacuum wave vector), but without limitations on the ratio of the wavelength to the Larmor radius (the usual approximation being limited to wavelengths much smaller than the Larmor radius). The reflection and transmission coefficients and the total energy absorption are given in this approximation, whereas the energy conservation theorem for the reflection and transmission coefficients in an absorption-free plasma are derived for every value of η without explicit knowledge of the solutions. Finally, a general and compact equation for the eigenvalues which does not require complex analysis and knowledge of all solutions of the dispersion relation is given. (orig.)

Carbon dioxide adsorption on a ZnO(101[combining macron]0) substrate studied by infrared reflection absorption spectroscopy.

Science.gov (United States)

Buchholz, Maria; Weidler, Peter G; Bebensee, Fabian; Nefedov, Alexei; Wöll, Christof

2014-01-28

The adsorption of carbon dioxide on the mixed-terminated ZnO(101[combining macron]0) surface of a bulk single crystal was studied by UHV Infrared Reflection Absorption Spectroscopy (IRRAS). In contrast to metals, the classic surface selection rule for IRRAS does not apply to bulk oxide crystals, and hence vibrational bands can also be observed for s-polarized light. Although this fact substantially complicates data interpretation, a careful analysis allows for a direct determination of the adsorbate geometry. Here, we demonstrate the huge potential of IR-spectroscopy for investigations on oxide single crystal surfaces by considering all three components of the incident polarized light separately. We find that the tridentate (surface) carbonate is aligned along the [0001] direction. A comparison to data reported previously for CO2 adsorbed on the surfaces of ZnO nanoparticles provides important insight into the role of defects in the surface chemistry of powder particles.

Polarized neutron reflectivity study of a thermally treated MnIr/CoFe exchange bias system.

Science.gov (United States)

Awaji, Naoki; Miyajima, Toyoo; Doi, Shuuichi; Nomura, Kenji

2010-12-01

It has recently been found that the exchange bias of a MnIr/CoFe system can be increased significantly by adding a thermal treatment to the bilayer. To reveal the origin of the higher exchange bias, we performed polarized neutron reflectivity measurements at the JRR-3 neutron source. The magnetization vector near the MnIr/CoFe interface for thermally treated samples differed from that for samples without the treatment. We propose a model in which the pinned spin area at the interface is extended due to the increased roughness and atomic interdiffusion that result from the thermal treatment.

Production of sealed sup 6 sup 0 Co and sup 1 sup 9 sup 2 Ir sources of high specific activity in the nuclear reactor RA

International Nuclear Information System (INIS)

Dobrijevic, R.; Vucina, J.

1998-01-01

Given is a review on the development of the production of 60 Co and 192 Ir performed in the Vinca Institute in the nuclear reactor RA. The experience gained showed that this reactor was suitable for obtaining of these and some other radionuclides. One possibility of its re-start is that the performances of the reactor remain the same (power 6.5 MW, max.neutron flux up to 6x10 13 n.cm -2 s -1 ). By applying new techniques of target preparation, 60 Co for sterilization units of specific activity 1.11 TBq/g could be produced. Maximal activity of sup 1 sup 9 sup 2 Ir would be about 1.48 TBq what is satisfactory for the sources for gamma radiography. The increase of the flux to 10 14 n.cm -2 s -1 would enable the production of 60 Co of specific activities about 3.335 TBq/g. This is satisfactory for the sources for the radiation therapy of activities up to 111 TBq and for gamma radiography of activities about 0.37 TBq. In the case of 192 Ir the sources for the radiation therapy of activities about 0.37 TBq could be obtained. Maximal achievable activities of 192 Ir would be about 3.7 TBq. (author)

An overview on the research of Sr2IrO4-based system probed by X-ray absorption spectroscopy

Science.gov (United States)

Cheng, Jie; Zhu, Chaomin; Ma, Jingyuan; Wang, Yu; Liu, Shengli

2018-03-01

Investigations of materials with 5d transition metal ions have opened up new paradigms in condensed-matter physics because of their large spin-orbit coupling (SOC) interactions. The typical compound is Sr2IrO4, which attracted much attention due to its similarities to the parent compound of high-Tc cuprate superconductor La2CuO4. Theoretical calculations predicted that the unconventional superconductivity can occur in carrier doped-Sr2IrO4 system. Until now, hundreds of experimental methods were devoted to investigate the carrier doping effect on Sr2IrO4. Synchrotron radiation-based X-ray absorption spectroscopy (XAS) made great contributions to the local lattice and electronic structure, and also the intimate relationship between the local structure and physical properties induced by carrier doping. The aim of this review is a short introduction to the progress of research on Sr2IrO4-based system probed by the unique technique — XAS, including the strength of the SOC, valence changes upon doping and even local lattice structure with atomic level for this Sr2IrO4-based family.

Conformational aspects of proteins at the air/water interface studied by infrared reflection-absorption spectroscopy

NARCIS (Netherlands)

Martin, A.H.; Meinders, M.B.J.; Bos, M.A.; Cohen Stuart, M.A.; Vliet, T. van

2003-01-01

From absorption spectra obtained with infrared reflection - absorption spectroscopy (IRRAS), it is possible to obtain information on conformational changes at a secondary folding level of proteins adsorbed at the air/water interface. In addition, information on protein concentration at the interface

Study on seasonal IR signature change of a ship by considering seasonal marine environmental conditions

Science.gov (United States)

Kim, Do-Hwi; Han, Kuk-Il; Choi, Jun-Hyuk; Kim, Tae-Kuk

2017-05-01

Infrared (IR) signal emitted from objects over 0 degree Kelvin has been used to detect and recognize the characteristics of those objects. Recently more delicate IR sensors have been applied for various guided missiles and they affect a crucial influence on object's survivability. Especially, in marine environment it is more vulnerable to be attacked by IR guided missiles since there are nearly no objects for concealment. To increase the survivability of object, the IR signal of the object needs to be analyzed properly by considering various marine environments. IR signature of a naval ship consists of the emitted energy from ship surface and the reflected energy by external sources. Surface property such as the emissivity and the absorptivity on the naval ship varies with different paints applied on the surface and the reflected IR signal is also affected by the surface radiative property, the sensor's geometric position and various climatic conditions in marine environment. Since the direct measurement of IR signal using IR camera is costly and time consuming job, computer simulation methods are developing rapidly to replace those experimental tasks. In this study, we are demonstrate a way of analyzing the IR signal characteristics by using the measured background IR signals using an IR camera and the estimated target IR signals from the computer simulation to find the seasonal trends of IR threats of a naval ship. Through this process, measured weather data are used to analyze more accurate IR signal conditions for the naval ship. The seasonal change of IR signal contrast between the naval ship and the marine background shows that the highest contrast radiant intensity (CRI) value is appeared in early summer.

Numerical analysis on the absorption, reflection and transmission of radar waves by a uniform magnetized plasma slab

International Nuclear Information System (INIS)

Tang Deli; Sun Aiping; Qiu Xiaoming

2002-01-01

The absorption, reflection, and transmission of radar waves by a uniform and magnetized plasma slab are studied. The effect of various plasma parameters and different values of magnetic field intensity on the absorbed, reflected and transmitted power are discussed. The calculated results show that the effects of magnetic field on the absorbed power as well as the frequency band of resonant absorption are very significant. More than 90% of radar wave power can be absorbed and the resonant absorption band is about 2G Hz

Modification of UV absorption profile of polymer film reflectors to increase solar-weighted reflectance

Science.gov (United States)

Jorgensen, Gary; Gee, Randall C.; White, David

2017-05-02

Provided are reflective thin film constructions including a reduced number of layers, which provides for increased solar-weighted hemispherical reflectance and durability. Reflective films include those comprising an ultraviolet absorbing abrasion resistant coating over a metal layer. Also provided are ultraviolet absorbing abrasion resistant coatings and methods for optimizing the ultraviolet absorption of an abrasion resistant coating. Reflective films disclosed herein are useful for solar reflecting, solar collecting, and solar concentrating applications, such as for the generation of electrical power.

Bio-inspired, sub-wavelength surface structures for ultra-broadband, omni-directional anti-reflection in the mid and far IR.

Science.gov (United States)

Gonzalez, Federico Lora; Gordon, Michael J

2014-06-02

Quasi-ordered moth-eye arrays were fabricated in Si using a colloidal lithography method to achieve highly efficient, omni-directional transmission of mid and far infrared (IR) radiation. The effect of structure height and aspect ratio on transmittance and scattering was explored experimentally and modeled quantitatively using effective medium theory. The highest aspect ratio structures (AR = 9.4) achieved peak transmittance of 98%, with >85% transmission for λ = 7-30 μm. A detailed photon balance was constructed by measuring transmission, forward scattering, specular reflection and diffuse reflection to quantify optical losses due to near-field effects. In addition, angle-dependent transmission measurements showed that moth-eye structures provide superior anti-reflective properties compared to unstructured interfaces over a wide angular range (0-60° incidence). The colloidal lithography method presented here is scalable and substrate-independent, providing a general approach to realize moth-eye structures and anti-reflection in many IR-compatible material systems.

Reduction of cross-polarized reflection to enhance dual-band absorption

Science.gov (United States)

Kundu, Debidas; Mohan, Akhilesh; Chakrabarty, Ajay

2016-11-01

In this paper, cross-polarized reflection from a periodic array of metal-dielectric-metal resonator units is reduced to improve its absorbing performance. Through this simple and typical example, it is shown that some reported absorbers are actually poor absorbers but efficient polarization converters, when the cross-polarized reflection is considered. Using a frequency selective surface, sandwiched between the top layer and the ground plane, the cross-polarized reflection is reduced by 7.2 dB at 5.672 GHz and 8.5 dB at 9.56 GHz, while negligibly affecting the co-polarized reflection reduction performance. The polarization conversion ratio is reduced from 90. 74% to 34.12% and 98.51% to 27.2% and total absorption is improved up to 80% from 26% and 21% around the two resonant frequencies. The reflection characteristics of the proposed absorber are quantitatively analyzed using interference theory, where the near field coupling of the resonant geometries and ground is taken into account. Measurement results show good agreement with both the numerically simulated and theoretical results.

Nuclear Reactor RA Safety Report, Vol. 8, Auxiliary system; Izvestaj o sigurnosti nuklearnog reaktora RA, Knjiga 8, Pomocni sistemi

Energy Technology Data Exchange (ETDEWEB)

NONE

1986-11-01

This volume describes RA reactor auxiliary systems, as follows: special ventilation system, special drainage system, hot cells, systems for internal transport. Ventilation system is considered as part of the reactor safety and protection system. Its role is eliminate possible radioactive particles dispersion in the environment. Special drainage system includes pipes and reservoirs with the safety role, meaning absorption or storage of possible radioactive waste water from the reactor building. Hot cells existing in the RA reactor building are designed for production of sealed radioactive sources, including packaging and transport. [Serbo-Croat] Ova knjiga obuhvata opis pomocnih sistem reaktora RA: sistem specijalne ventilacije, sistem specijalne kanalizacije, vruce komore, sistemi za unutrasnji transport. Ventilacioni sistem je znacajan deo sistema zastite i sigurnosti reaktora. Njegova je uloga da onemoguci disperziju radioaktivnih cestica u okolinu. Sistem specijalne kanalizacije sastoji se od agregata, cevovoda i rezervoara sa sigurnosnom armaturom i ima zadatak da prihvata i u sebe deponuje radioaktivne otpadne vode iz objekarta reaktora RA. U zgradi reaktora RA postoje vruce komore koje su namenjene za proizvodnju zatvorenih izvora zracenje, ukljucujuci i mehanicku obradu, prepakivanje i transport.

X-ray reflectivity of cobalt and titanium in the vicinity of the Lsub(2,3) absorption edges

International Nuclear Information System (INIS)

Bremer, J.; Kaihola, L.; Keski-Kuha, R.

1980-01-01

X-ray reflectivity across cobalt and titanium Lsub(2,3) absorption edges was measured as a function of energy by means of continuous radiation from a tungsten anode in a grating spectrometer. The real and imaginary parts of the refractive index were obtained from the absorption curves and an exact Kramers-Kronig analysis. A measured fine structure in the reflected intensities was interpreted as an effect of white lines in the absorption spectra. The x-ray intensity was calculated as a function of energy by means of the Fresnel formula. (author)

Enhancing the sensitivity of mid-IR quantum cascade laser-based cavity-enhanced absorption spectroscopy using RF current perturbation.

Science.gov (United States)

Manfred, Katherine M; Kirkbride, James M R; Ciaffoni, Luca; Peverall, Robert; Ritchie, Grant A D

2014-12-15

The sensitivity of mid-IR quantum cascade laser (QCL) off-axis cavity-enhanced absorption spectroscopy (CEAS), often limited by cavity mode structure and diffraction losses, was enhanced by applying a broadband RF noise to the laser current. A pump-probe measurement demonstrated that the addition of bandwidth-limited white noise effectively increased the laser linewidth, thereby reducing mode structure associated with CEAS. The broadband noise source offers a more sensitive, more robust alternative to applying single-frequency noise to the laser. Analysis of CEAS measurements of a CO(2) absorption feature at 1890  cm(-1) averaged over 100 ms yielded a minimum detectable absorption of 5.5×10(-3)  Hz(-1/2) in the presence of broadband RF perturbation, nearly a tenfold improvement over the unperturbed regime. The short acquisition time makes this technique suitable for breath applications requiring breath-by-breath gas concentration information.

Theoretical characterization of quaternary iridium based hydrides NaAeIrH{sub 6} (Ae = Ca, Ba and Sr)

Energy Technology Data Exchange (ETDEWEB)

Bouras, S. [Laboratory of Studies Surfaces and Interfaces of Solids Materials, Department of Physics, Faculty of Science, University of Setif 1, 19000 (Algeria); Ghebouli, B., E-mail: bghebouli@yahoo.fr [Laboratory of Studies Surfaces and Interfaces of Solids Materials, Department of Physics, Faculty of Science, University of Setif 1, 19000 (Algeria); Benkerri, M. [Laboratory of Studies Surfaces and Interfaces of Solids Materials, Department of Physics, Faculty of Science, University of Setif 1, 19000 (Algeria); Ghebouli, M.A., E-mail: med.amineghebouli@yahoo.fr [Microelectronic Laboratory (LMSE), University of Bachir Ibrahimi, Bordj-Bou-Arreridj 34000 (Algeria); Research Unit on Emerging Materials (RUEM), University of Setif 1, 19000 (Algeria); Choutri, H. [Microelectronic Laboratory (LMSE), University of Bachir Ibrahimi, Bordj-Bou-Arreridj 34000 (Algeria); Louail, L.; Chihi, T.; Fatmi, M. [Research Unit on Emerging Materials (RUEM), University of Setif 1, 19000 (Algeria); Bouhemadou, A. [Laboratory for Developing New Materials and Their Characterization, Department of Physics, Faculty of Science, University of Setif 1, 19000 (Algeria); Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Khenata, R.; Khachai, H. [Laboratoire de Physique Quantique et de Modélisation Mathématique, Université de Mascara, 29000 (Algeria)

2015-01-15

The quaternary iridium based hydrides NaAeIrH{sub 6} (Ae = Ca, Ba and Sr) are promising candidates as hydrogen storage materials. We have studied the structural, elastic, electronic, optical and thermodynamic properties of NaAeIrH{sub 6} (Ae = Ca, Ba and Sr) within the generalized gradient approximation, the local density approximation (LDA) and mBj in the frame of density functional perturbation theory. These alloys have a large indirect Γ–X band gap. The thermodynamic functions were computed using the phonon density of states. The origin of the possible transitions from valence band to conduction band was illustrated. By using the complex dielectric function, the optical properties such as absorption, reflectivity, loss function, refractive index and optical conductivity have been obtained. - Graphical abstract: Real and imaginary parts of the dielectric function, the absorption spectrum α(ω), reflectivity R(ω) and energy-loss spectrum L(ω). - Highlights: • NaAeIrH{sub 6} (Ae = Ca, Ba and Sr) alloys have been investigated. • The elastic moduli, energy gaps are predicted. • The optical and thermal properties were studied.

Measuring the radium quartet (228Ra, 226Ra, 224Ra, 223Ra) in seawater samples using gamma spectrometry

International Nuclear Information System (INIS)

Beek, P. van; Souhaut, M.; Reyss, J.-L.

2010-01-01

Radium isotopes are widely used in marine studies (eg. to trace water masses, to quantify mixing processes or to study submarine groundwater discharge). While 228 Ra and 226 Ra are usually measured using gamma spectrometry, short-lived Ra isotopes ( 224 Ra and 223 Ra) are usually measured using a Radium Delayed Coincidence Counter (RaDeCC). Here we show that the four radium isotopes can be analyzed using gamma spectrometry. We report 226 Ra, 228 Ra, 224 Ra, 223 Ra activities measured using low-background gamma spectrometry in standard samples, in water samples collected in the vicinity of our laboratory (La Palme and Vaccares lagoons, France) but also in seawater samples collected in the plume of the Amazon river, off French Guyana (AMANDES project). The 223 Ra and 224 Ra activities determined in these samples using gamma spectrometry were compared to the activities determined using RaDeCC. Activities determined using the two techniques are in good agreement. Uncertainties associated with the 224 Ra activities are similar for the two techniques. RaDeCC is more sensitive for the detection of low 223 Ra activities. Gamma spectrometry thus constitutes an alternate method for the determination of short-lived Ra isotopes.

Comparison of conventional and total reflection excitation geometry for fluorescence X-ray absorption spectroscopy on droplet samples

International Nuclear Information System (INIS)

Falkenberg, G.; Pepponi, G.; Streli, C.; Wobrauschek, P.

2003-01-01

X-ray absorption fine structure (XAFS) experiments in fluorescence mode have been performed in total reflection excitation geometry and conventional 45 deg. /45 deg. excitation/detection geometry for comparison. The experimental results have shown that XAFS measurements are feasible under normal total reflection X-ray fluorescence (TXRF) conditions, i.e. on droplet samples, with excitation in grazing incidence and using a TXRF experimental chamber. The application of the total reflection excitation geometry for XAFS measurements increases the sensitivity compared to the conventional geometry leading to lower accessible concentration ranges. However, XAFS under total reflection excitation condition fails for highly concentrated samples because of the self-absorption effect

Non-invasive determination of the absorption coefficient of the brain from time-resolved reflectance using a neural network

International Nuclear Information System (INIS)

Jaeger, Marion; Kienle, Alwin

2011-01-01

We investigated the performance of a neural network for derivation of the absorption coefficient of the brain from simulated non-invasive time-resolved reflectance measurements on the head. A five-layered geometry was considered assuming that the optical properties (except the absorption coefficient of the brain) and the thickness of all layers were known with an uncertainty. A solution of the layered diffusion equation was used to train the neural network. We determined the absorption coefficient of the brain with an RMS error of <6% from reflectance data at a single distance calculated by diffusion theory. By applying the neural network to reflectance curves obtained from Monte Carlo simulations, similar errors were found. (note)

Synthesis and microwave absorption properties of PPy/Co nanocomposites

Energy Technology Data Exchange (ETDEWEB)

Luo, Juhua, E-mail: luojuhua@163.com [School of Materials Engineering, Yancheng Institute of Technology, Yancheng 224051 (China); Gao, Duoduo [School of Material Science and Engineering, Changzhou University, Changzhou 213164 (China)

2014-11-15

Polypyrrole (PPy)/cobalt (Co) nanocomposites were successfully prepared by an in-situ polymerization of pyrrole in the presence of synthesized Co nanoparticles. Characterization of the product was accomplished by XRD, TEM, FT-IR, VSM, and vector network analyzer techniques. XRD analysis revealed that characteristic diffraction peaks of polypyrrole and Co appeared at the same time in nanocomposites. FT-IR analysis indicated a successful conjugation of Co particles with polypyrrole. TEM confirmed the formation of a core-shell structure with a wide particle size distribution. Magnetization measurements showed that polypyrrole coating decreased the saturation magnetization of Co significantly. With the increase of the matching thickness, the absorption peak varied towards low frequency direction. When the matching thickness was 3.0 mm, the value of the maximum reflection loss (RL) was −20.0 dB at 13.8 GHz with the 7.2 GHz bandwidth. - Highlights: • The influence of PPy on the structure of Co is discussed. • The influence of PPy on the magnetic properties of Co is discussed. • The influence of PPy on the absorption property of Co is discussed. • PPy/Co possessed the excellent absorption property.

Formulation comprising silicon microparticles, as a pigment that can absorb visible UV radiation and reflect ir radiation

OpenAIRE

Rodríguez, Marie-Isabelle; Fenollosa Esteve, Roberto; Meseguer, Francisco

2011-01-01

[EN] The invention relates to a formulation characterised in that it comprises silicon microparticles having a size between 0.010 um and 50 um in diameter, and to the use thereof as a pigment that can absorb visible UV radiation and reflect IR radiation.

Komiksai Lietuvoje: nepanaudotas kultūrinis ir edukacinis įrankis

Directory of Open Access Journals (Sweden)

Tomas Mitkus

2013-04-01

Full Text Available Straipsnyje autorius kelia hipotezę, kad stipri komiksų industrija gali tapti svarbiu elementu, efektyviai siekiant įvykdyti Lietuvos kultūros ir Švietimo ministerijų XXI amžiui iškeltus strateginius nacionalinius uždavinius. Straipsnyje pateikiamas JAV komiksų medijos diskursas ir nuodugniai analizuojama Lietuvos komiksų industrijos padėtis, atliekant kokybines ir kiekybines apklausas. Rezultatai atskleidžia, kad tarp jauniausios Lietuvos kartos de facto yra įsitvirtinusi komiksų kultūra.

Infrared absorption of human breast tissues in vitro

Energy Technology Data Exchange (ETDEWEB)

Liu Chenglin [Department of Physics, Surface Physics Laboratory (National Key laboratory), Synchrotron Radiation Research Center, Fudan University, Shanghai 200433 (China); Physics Department of Yancheng Teachers' College, Yancheng 224002 (China); Zhang Yuan [Department of Physics, Surface Physics Laboratory (National Key laboratory), Synchrotron Radiation Research Center, Fudan University, Shanghai 200433 (China); Yan Xiaohui [Department of Physics, Surface Physics Laboratory (National Key laboratory), Synchrotron Radiation Research Center, Fudan University, Shanghai 200433 (China); Zhang Xinyi [Department of Physics, Surface Physics Laboratory (National Key laboratory), Synchrotron Radiation Research Center, Fudan University, Shanghai 200433 (China) and Shanghai Research Center of Acupuncture and Meridian, Pudong, Shanghai 201203 (China)]. E-mail: xy-zhang@fudan.edu.cn; Li Chengxiang [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Yang Wentao [Cancer Hospital, Medical Center, Fudan University, Shanghai 200032 (China); Shi Daren [Cancer Hospital, Medical Center, Fudan University, Shanghai 200032 (China)

2006-07-15

The spectral characteristics of human breast tissues in normal status and during different cancerous stages have been investigated by synchrotron radiation based Fourier transform infrared (SR-FTIR) absorption spectroscopy. Thanks to the excellent synchrotron radiation infrared (IR) source, higher resolving power is achieved in SR-FTIR absorption spectra than in conventional IR absorption measurements. Obvious variations in IR absorption spectrum of breast tissues were found as they change from healthy to diseased, or say in progression to cancer. On the other hand, some specific absorption peaks were found in breast cancer tissues by SR-FTIR spectroscopic methods. These spectral characteristics of breast tissue may help us in early diagnosis of breast cancer.

The study of the radiation chemical transformation of the hexane on the surface of aluminium by IR-spectroscopy method

International Nuclear Information System (INIS)

Rimikhanova, A.N.

2006-01-01

Full text: In this work the experimental results of the radiation-chemical transformation of hexane on the aluminum surface obtained by IR spectroscopy method at room temperature have been presented. The metallic aluminum plates which was obtained by stage pressing granules by mark of AD-00 with the reflection coefficient R=0,85 in the middle infrared range of waves length λ=15 ± 2,2 mkm were used. As an adsorbate unsaturated vapors of hexane were used, the absorption of which was being carried out at the room temperature by the method. The radiation of system was carried out with γ-quanta of Co 60 with doze rate of 1,03 Gy/s - 1, and the absorbed doze in the system was (0,5-2)10 4 Gy. IR reflection spectra when beams fall on the sample under angle near the slipping were measured in diapason of 3600-650 cm - 1 by the spectrophotometer S pecord 71IR . The radiation chemical decomposition of hexane in heterosystem was being traced in stretching (3000-2700 cm - 1) and deformation (1500-1300 cm - 1) vibration diapasons of C-H bonds. The analysis of IR reflection spectra of Al-ads.hexane heterosystem showed that the main products of radiation chemical transformation are hydrocarbons C1-C5, olefins: propylene, butene-1, hexene-1, transhexene-3 and hydrocarbons more heavy than hexane. In frequency range of 1700-2000 cm - 1 the absorption bands of Al-H vibration which concern to aluminum hydrides are founded. By increasing of radiation dose the tendency of increasing of hydrogen accumulation as aluminum hydrides has been established

Recenzija. Monografija apie filosofijos ir literatūros giminystę

Directory of Open Access Journals (Sweden)

Tomas Kačerauskas

2011-04-01

Full Text Available Prieš keletą metų neoficialiame pokalbyje J. Baranova prasitarė, kad nėra didesnio malonumo už rašymą. Tiesą sakant, buvau sužavėtas ir priblokštas ne tik dėl šios ištaros asimetrijos R. Barthes’o minčiai apie skaitymo malonumą (net erotinį. Visai kitaip apie rašymą atsiliepia A. Šliogeris (kurio filosofi jos apmąstymui J. Baranova pelnytai skiria daug dėmesio: jis mieliau nerašytų nei rašytų. Tokiais atvejais prisimenu M. Bulgakovą, kuris „tempiąs save už plaukų prie rašomojo stalo“. Rašymas daug kam siejasi su disciplina, prievarta savęs atžvilgiu, geriausiu atveju – kasdieniu įpročiu.

Far-infrared reflection-absorption spectroscopy of amorphous and polycrystalline gallium arsenide films

International Nuclear Information System (INIS)

Gregory, J.R.

1992-01-01

We have reported far-infrared reflection absorption spectra (30-320CM -1 ) at 30 and 310K for nine films of non-stoichiometric GaAs. The FIRRAS measurements were performed using the grazing incidence FIR double-modulation spectroscopy technique first described by DaCosta and Coleman. The films were fabricated by molecular beam deposition on metallized substrates for two As/Ga molecular beam flux ratios. The films were characterized by depth profilometry, IRAS, XRD, and x-ray microprobe analysis. Film thicknesses ranged from 800 to 5800 angstrom and compositions were 45-50% As for a MB flux ratio of 0.29 and 60-70% As for a ratio of 1.12. FIRRAS measurements were made and characterizations performed for as-deposited films and for 5 hour anneals at 473, 573, 673 and 723 degrees C. Vibrational spectra of the crystallized films were interpreted in terms of the exact reflectivity of a thin dielectric film on a conducting substrate, using a classical Lorentzian dielectric function for the response of the film. Resonances appearing in the open-quote forbidden close-quote region between the TO and LO frequencies were modelled with an effective medium approximation and are interpreted as arising from small-scale surface roughness. The behavior of the amorphous film spectra were examined within two models. The effective force constant model describes the variation of the reflection-absorption maxima with measured crystallite size in terms of the effective vibration frequency of 1-D atomic chains having force constants distributed according to the parameters of the crystalline-to-amorphous relaxation length and the crystalline to amorphous force constant ratio. The dielectric function continuum model uses the relaxation of the crystal momentum selection rule to calculate the reflection-absorption spectrum based on a dielectric function in which the oscillator strength is the normalized product of a constant dipole strength and the smoothed vibrational density of states

Moteriškumas ir nutylėto žodžio retorika Romaino Gary romane „Aitvarai“

OpenAIRE

Skrupskelytė, Viktorija

2009-01-01

Romaino Gary romanuose, pokalbiuose ir eseistinės formos kūriniuose gausu pastabų apie moteriškumą (pr. féminité) ir moteriškas vertybes (pr. valeurs féminines), rašytojo dar vadinamų moterišku kalbėjimu, la voix féminine. Tačiau šias sąvokas Gary supranta savotiškai – kaip tam tikrą neigiamą ryšį su žmogų supančia bei jį valdančia aplinka ir žmogaus sukurtomis ar jo toleruojamomis jėgos struktūromis. Jėgai rašytojas priešpriešina moteriškumo ir silpnumo (pr. faiblesse) būsenas, j...

Uranium absorption study pile; Empilement pour le controle de l'absorption de l'uranium

Energy Technology Data Exchange (ETDEWEB)

Raievski, V; Sautiez, B [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

The report describes a pile designed to measure the absorption of fuel slugs. The pile is of graphite and comprises a central section composed of uranium rods in a regular lattice. RaBe sources and BF{sub 3} counters are situated on either side of the center. A given uranium charge is compared with a specimen charge of about 560 kg, and the difference in absorption between the two noted. The sensitivity of the equipment will detect absorption variations of about a few ppm boron (10{sup -6} boron per gr. of uranium) or better. (author) [French] Nous decrivons un dispositif permettant de mesurer l'absorption des elements combustibles d'une pile. Ce dispositif est constitue par un empilement de graphite dont la region centrale est formee par un reseau regulier de barres d'uranium. Des sources de RaBe et des compteurs a BF{sub 3} sont places de part et d'autre de cette region. En comparant un chargement d'uranium a un chargement etalon d'environ 560 kg, on peut determiner la difference d'absorption entre ces deux chargements. La sensibilite permettrait de deceler une variation d'absorption de l'ordre du ppm de bore (10{sup -6} g de bore par gramme d'uranium) et peut-etre mieux. (auteur)

Spectroelectrochemical study of polyphenylene by in situ external reflection FT-IR spectroscopy. Pt. 2

International Nuclear Information System (INIS)

Kvarnstroem, C.; Ivaska, A.

1994-01-01

In situ external reflection FT-IR measurements are performed during cyclic voltammetric scans on electrochemically polymerized polyphenylene films. The films are polymerized either in 0.1 or 0.8 M biphenyl in 0.1 M TBABF 4 in acetonitrile. Changes in the IR spectrum of films of different thicknesses are studied when the films are potentially cycled from the neutral to the oxidized states of the polymer. No differences between films made in high or low dimer concentration can be observed in the spectra. The potential-dependent insertion and expulsion of solvent, residual water, anions and cations in and out of the film have different behaviour in films of different thicknesses. Changes in the structure of the segments in the film, from the benzenoid form into the quinoid form, can be followed. Differences between the first and subsequent cyclic potential scans are observed. (orig.)

Dramatisko žanru problēma Šekspīra lugās

OpenAIRE

Klintsone, Sintija

2009-01-01

Darbā tiek aplūkota Žanru problēma Šekspīra lugās (ar viņa lugu „Divi veronieši”, „Spītnieces savaldīšana” un „Romeo un Džuljeta” detalizētāku analīzi). Darbā pētīta Šekspīra mainīgā attieksme pret komisko divās no viņa komēdijām un vienā traģēdijā, kā arī uzstādījums, ka komēdijas no traģēdijām šķir tikai vissmalkākā laika un vietas robeža - ka katra no tām sevī slēpju iespēju vienā mirklī mainīt žanru – un ka šī iespēja ir tā, kas piešķir katrai lugai tās īpašo spēku. Pētījums snied...

Electronic structure, local magnetism, and spin-orbit effects of Ir(IV)-, Ir(V)-, and Ir(VI)-based compounds

Energy Technology Data Exchange (ETDEWEB)

Laguna-Marco, M. A.; Kayser, P.; Alonso, J. A.; Martínez-Lope, M. J.; van Veenendaal, M.; Choi, Y.; Haskel, D.

2015-06-01

Element- and orbital-selective x-ray absorption and magnetic circular dichroism measurements are carried out to probe the electronic structure and magnetism of Ir 5d electronic states in double perovskite Sr2MIrO6 (M = Mg, Ca, Sc, Ti, Ni, Fe, Zn, In) and La2NiIrO6 compounds. All the studied systems present a significant influence of spin-orbit interactions in the electronic ground state. In addition, we find that the Ir 5d local magnetic moment shows different character depending on the oxidation state despite the net magnetization being similar for all the compounds. Ir carries an orbital contribution comparable to the spin contribution for Ir4+ (5d(5)) and Ir5+ (5d(4)) oxides, whereas the orbital contribution is quenched for Ir6+ (5d(3)) samples. Incorporation of a magnetic 3d atom allows getting insight into the magnetic coupling between 5d and 3d transition metals. Together with previous susceptibility and neutron diffractionmeasurements, the results indicate that Ir carries a significant local magnetic moment even in samples without a 3d metal. The size of the (small) net magnetization of these compounds is a result of predominant antiferromagnetic interactions between local moments coupled with structural details of each perovskite structure

Serum progranulin irrelated with Breg cell levels, but elevated in RA patients, reflecting high disease activity.

Science.gov (United States)

Chen, Jiaxi; Li, Shuang; Shi, Jianfeng; Zhang, Lili; Li, Jun; Chen, Shiyong; Wu, Chunlong; Shen, Bo

2016-03-01

Soluble progranulin (PGRN) is known to directly regulate regulatory T cells; however, whether PGRN levels are elevated in patients with rheumatoid arthritis and affect the regulatory subsets of B cells remain unknown. In this study, a total of 80 RA patients and 60 healthy controls were studied. Serum progranulin levels were determined using enzyme-linked immune-sorbent assay. A receiver operating characteristic (ROC) curve was used to evaluate the feasibility of serum PGRN as a biomarker for distinguishing patients with RA. CD19(+)CD5(+)GrB(+) B cells were analyzed by flow cytometry in peripheral blood mononuclear cells (PBMCs). Serum progranulin levels in RA patients (median, 59.4 ng/mL) and in RA patients DAS28 > 5.1 (median, 71.98 ng/mL) were much higher than those in normal controls (median, 46.3 ng/mL; P progranulin levels was 0.705 for RA versus normal controls and the area under the ROC curve for progranulin levels in RA patients DAS28 > 5.1 was 0.977 versus normal controls (P progranulin and DAS28, CRP, ESR were all positively correlated in RA patients (P 0.05). Our findings indicated that induction of PGRN expression may play a role in RA immune reaction and PGRN levels could be a useful biomarker in RA inflammatory response, but irrelated with Breg cell levels.

Microwave reflection, transmission, and absorption by human brain tissue

Science.gov (United States)

Ansari, M. A.; Akhlaghipour, N.; Zarei, M.; Niknam, A. R.

2018-04-01

These days, the biological effects of electromagnetic (EM) radiations on the brain, especially in the frequency range of mobile communications, have caught the attention of many scientists. Therefore, in this paper, the propagation of mobile phone electromagnetic waves in the brain tissues is investigated analytically and numerically. The brain is modeled by three layers consisting of skull, grey and white matter. First, we have analytically calculated the microwave reflection, transmission, and absorption coefficients using signal flow graph technique. The effect of microwave frequency and variations in the thickness of layers on the propagation of microwave through brain are studied. Then, the penetration of microwave in the layers is numerically investigated by Monte Carlo method. It is shown that the analytical results are in good agreement with those obtained by Monte Carlo method. Our results indicate the absorbed microwave energy depends on microwave frequency and thickness of brain layers, and the absorption coefficient is optimized at a number of frequencies. These findings can be used for comparing the microwave absorbed energy in a child's and adult's brain.

Cirrus Cloud Optical and Microphysical Property Retrievals from eMAS During SEAC4RS Using Bi-Spectral Reflectance Measurements Within the 1.88 micron Water Vapor Absorption Band

Science.gov (United States)

Meyer, K.; Platnick, S.; Arnold, G. T.; Holz, R. E.; Veglio, P.; Yorks, J.; Wang, C.

2016-01-01

Previous bi-spectral imager retrievals of cloud optical thickness (COT) and effective particle radius (CER) based on the Nakajima and King (1990) approach, such as those of the operational MODIS cloud optical property retrieval product (MOD06), have typically paired a non-absorbing visible or near-infrared wavelength, sensitive to COT, with an absorbing shortwave or midwave infrared wavelength sensitive to CER. However, in practice it is only necessary to select two spectral channels that exhibit a strong contrast in cloud particle absorption. Here it is shown, using eMAS observations obtained during NASAs SEAC4RS field campaign, that selecting two absorbing wavelength channels within the broader 1.88 micron water vapor absorption band, namely the 1.83 and 1.93 micron channels that have sufficient differences in ice crystal single scattering albedo, can yield COT and CER retrievals for thin to moderately thick single-layer cirrus that are reasonably consistent with other solar and IR imager-based and lidar-based retrievals. A distinct advantage of this channel selection for cirrus cloud retrievals is that the below cloud water vapor absorption minimizes the surface contribution to measured cloudy TOA reflectance, in particular compared to the solar window channels used in heritage retrievals such as MOD06. This reduces retrieval uncertainty resulting from errors in the surface reflectance assumption, as well as reduces the frequency of retrieval failures for thin cirrus clouds.

Mid-IR Absorption Cross-Section Measurements of Hydrocarbons

KAUST Repository

Alrefae, Majed Abdullah

2013-01-01

-known at combustion-relevant conditions. Absorption cross-section is an important spectroscopic quantity and has direct relation to the species concentration. In this work, the absorption cross-sections of basic hydrocarbons are measured using Fourier Transform

Papīra darbi ka domāšanas veicinātāji pirmsskolā

OpenAIRE

Jevdokimova, Jūlija

2017-01-01

Jūlija J. (2017.) “Papīra darbi kā domāšanas veicinātāji pirmsskolā”. Kvalifikācijas darbs. Rīga: Latvijas Universitātes Pedagoģijas, psiholoģijas un mākslas fakultāte, 90 lpp, 16 att., 4 tab., bibl. 18 nos., latviešu, angļu val. Darbs sastāv no ievada, 5 nodaļām, secinājumiem un 16 pielikumiem. Autors ir vairākus mēnešus izgājis praksi pirmsskolas pedagoga amatā. Darbā ir veikts pētījums par domāšanas attīstību rokdarbu nodarbībās, veicot papīra darbus Darba mērķis ir izzināt un atklāt bēr...

Nuclear Reactor RA Safety Report, Vol. 8, Auxiliary system

International Nuclear Information System (INIS)

1986-11-01

This volume describes RA reactor auxiliary systems, as follows: special ventilation system, special drainage system, hot cells, systems for internal transport. Ventilation system is considered as part of the reactor safety and protection system. Its role is eliminate possible radioactive particles dispersion in the environment. Special drainage system includes pipes and reservoirs with the safety role, meaning absorption or storage of possible radioactive waste water from the reactor building. Hot cells existing in the RA reactor building are designed for production of sealed radioactive sources, including packaging and transport [sr

Critical Dispersion-Theory Tests of Silicon's IR Refractive Index

Science.gov (United States)

Karstens, William; Smith, D. Y.

Silicon strongly absorbs both visible and UV light, but is highly transparent in the IR. Hence, it is a common choice for infrared windows and lenses. However, optical design is hindered by literature index values that disagree by up to 1%. In contrast optical-glass indices are known to 0.01% or better. The most widely available silicon IR indices are based on bulk measurements using either Snell's-Law refraction by a prism or channel-spectra interference of front- and backsurface reflections from a planar sample. To test the physical acceptability of these data, we have developed criteria based on a Taylor expansion of the Kramers-Kronig relation for the index at energies below strong inter-band transitions. These tests require that the coefficients of the series in powers of energy squared must be positive within the region of transparency. This is satisfied by essentially all prism measurements; their small scatter arises primarily from impurities and doping. In contrast, channel-spectra data fail in the second and third coefficients. A review of the experimental analysis indicates three problems besides purity: incorrect channel number arising from a channel-spectra model that neglects spectrum distortion by the weak lattice absorption; use of a series expansion of mixed parity in photon energy to describe the even-parity index; and use of an incorrect absorption energy in the Li-Sellmeier dispersion formula. Recommendations for IR index values for pure silicon will be discussed. Supported in part by the US Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC02-06CH11357.

Preparation and labelling hydroxyapatite with 223Ra and 99mTc

International Nuclear Information System (INIS)

Malkova, E.; Micolova, P.; Vlk, M.; Kozempel, J.; Rabyk, M.

2015-01-01

The aim of this study was the preparation, studies and investigation of novel nanoparticles suitable for targeted delivery of 223 Ra and 99 mTc. Preliminary experiments were focused on the synthesis of hydroxyapatite nanoparticles (HANPs) and their affinity to 223 Ra and 99m Tc. Technetium-99m ( 99 mTc, T 1 /2 = 6.0 h) is the most commonly used medical radionuclide for diagnostic procedures. Radium-223 is the first -emitting radionuclide approved for targeted radionuclide therapy. The physical half-life of 223 Ra of 11.4 days is providing sufficient time for the synthesis, distribution and administration of the radiopharmaceutical to patients. HANPs labelling yields with 223 Ra were 95 - 100 % and with 99m Tc were 93 - 94 % depending on the reaction conditions. HANPs were studied on FT-IR (Fourier transform infrared spectroscopy), XRPD (X-Ray Powder Diffraction), DLS (Dynamic Light Scattering), and the sizes of nanoparticles were studied at temperatures 80, 120 and 200 grad C. (authors)

Measuring the radium quartet ({sup 228}Ra, {sup 226}Ra, {sup 224}Ra, {sup 223}Ra) in seawater samples using gamma spectrometry

Energy Technology Data Exchange (ETDEWEB)

Beek, P. van, E-mail: vanbeek@legos.obs-mip.f [LEGOS, Laboratoire d' Etudes en Geophysique et Oceanographie Spatiales (CNRS/CNES/IRD/UPS), Observatoire Midi Pyrenees, 14 Avenue Edouard Belin, 31400 Toulouse (France); Souhaut, M. [LEGOS, Laboratoire d' Etudes en Geophysique et Oceanographie Spatiales (CNRS/CNES/IRD/UPS), Observatoire Midi Pyrenees, 14 Avenue Edouard Belin, 31400 Toulouse (France); Reyss, J.-L. [LSCE, Laboratoire des Sciences du Climat et de l' Environnement (CNRS/CEA/UVSQ), Avenue de la Terrasse, 91198 Gif-sur-Yvette (France)

2010-07-15

Radium isotopes are widely used in marine studies (eg. to trace water masses, to quantify mixing processes or to study submarine groundwater discharge). While {sup 228}Ra and {sup 226}Ra are usually measured using gamma spectrometry, short-lived Ra isotopes ({sup 224}Ra and {sup 223}Ra) are usually measured using a Radium Delayed Coincidence Counter (RaDeCC). Here we show that the four radium isotopes can be analyzed using gamma spectrometry. We report {sup 226}Ra, {sup 228}Ra, {sup 224}Ra, {sup 223}Ra activities measured using low-background gamma spectrometry in standard samples, in water samples collected in the vicinity of our laboratory (La Palme and Vaccares lagoons, France) but also in seawater samples collected in the plume of the Amazon river, off French Guyana (AMANDES project). The {sup 223}Ra and {sup 224}Ra activities determined in these samples using gamma spectrometry were compared to the activities determined using RaDeCC. Activities determined using the two techniques are in good agreement. Uncertainties associated with the {sup 224}Ra activities are similar for the two techniques. RaDeCC is more sensitive for the detection of low {sup 223}Ra activities. Gamma spectrometry thus constitutes an alternate method for the determination of short-lived Ra isotopes.

Deep and tapered silicon photonic crystals for achieving anti-reflection and enhanced absorption.

Science.gov (United States)

Hung, Yung-Jr; Lee, San-Liang; Coldren, Larry A

2010-03-29

Tapered silicon photonic crystals (PhCs) with smooth sidewalls are realized using a novel single-step deep reactive ion etching. The PhCs can significantly reduce the surface reflection over the wavelength range between the ultra-violet and near-infrared regions. From the measurements using a spectrophotometer and an angle-variable spectroscopic ellipsometer, the sub-wavelength periodic structure can provide a broad and angular-independent antireflective window in the visible region for the TE-polarized light. The PhCs with tapered rods can further reduce the reflection due to a gradually changed effective index. On the other hand, strong optical resonances for TM-mode can be found in this structure, which is mainly due to the existence of full photonic bandgaps inside the material. Such resonance can enhance the optical absorption inside the silicon PhCs due to its increased optical paths. With the help of both antireflective and absorption-enhanced characteristics in this structure, the PhCs can be used for various applications.

Implementation of real-time multiple reflection and Fresnel absorption of laser beam in keyhole

International Nuclear Information System (INIS)

Cho, Jung-Ho; Na, Suck-Joo

2006-01-01

A computational analysis of laser keyhole welding is achieved. The main driving force to make the molten pool as a narrow and deep keyhole is the recoil pressure induced by evaporation of the material. Also, the multiple reflection effect on the keyhole wall plays an important role in making the keyhole deeper and raising its total energy absorption rate. Multiple reflection and Fresnel absorption are implemented simultaneously with the proposed ray tracing technique in a discrete grid cell system during the simulation for every single time step. In particular, the Fresnel absorption model is chosen as an energy transfer mechanism from laser beam to workpiece. With all the governing equations including continuity, momentum and energy equation, the VOF method is adopted to trace the free surface of the molten pool. Simulation results are compared with the experimental ones to verify its validity. A pulsed Nd : YAG laser was used for keyhole welding experiments on mild steel plates of 7 mm thickness. It was observed that the generated keyhole maintains its solidified shape without any closing phenomenon both in the experiments and in the simulations

Implementation of real-time multiple reflection and Fresnel absorption of laser beam in keyhole

Energy Technology Data Exchange (ETDEWEB)

Cho, Jung-Ho; Na, Suck-Joo [Department of Mechanical Engineering, KAIST, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

2006-12-21

A computational analysis of laser keyhole welding is achieved. The main driving force to make the molten pool as a narrow and deep keyhole is the recoil pressure induced by evaporation of the material. Also, the multiple reflection effect on the keyhole wall plays an important role in making the keyhole deeper and raising its total energy absorption rate. Multiple reflection and Fresnel absorption are implemented simultaneously with the proposed ray tracing technique in a discrete grid cell system during the simulation for every single time step. In particular, the Fresnel absorption model is chosen as an energy transfer mechanism from laser beam to workpiece. With all the governing equations including continuity, momentum and energy equation, the VOF method is adopted to trace the free surface of the molten pool. Simulation results are compared with the experimental ones to verify its validity. A pulsed Nd : YAG laser was used for keyhole welding experiments on mild steel plates of 7 mm thickness. It was observed that the generated keyhole maintains its solidified shape without any closing phenomenon both in the experiments and in the simulations.

Uranium absorption study pile

International Nuclear Information System (INIS)

Raievski, V.; Sautiez, B.

1959-01-01

The report describes a pile designed to measure the absorption of fuel slugs. The pile is of graphite and comprises a central section composed of uranium rods in a regular lattice. RaBe sources and BF 3 counters are situated on either side of the center. A given uranium charge is compared with a specimen charge of about 560 kg, and the difference in absorption between the two noted. The sensitivity of the equipment will detect absorption variations of about a few ppm boron (10 -6 boron per gr. of uranium) or better. (author) [fr

Evaluating Multispectral Snowpack Reflectivity With Changing Snow Correlation Lengths

Science.gov (United States)

Kang, Do Hyuk; Barros, Ana P.; Kim, Edward J.

2016-01-01

This study investigates the sensitivity of multispectral reflectivity to changing snow correlation lengths. Matzler's ice-lamellae radiative transfer model was implemented and tested to evaluate the reflectivity of snow correlation lengths at multiple frequencies from the ultraviolet (UV) to the microwave bands. The model reveals that, in the UV to infrared (IR) frequency range, the reflectivity and correlation length are inversely related, whereas reflectivity increases with snow correlation length in the microwave frequency range. The model further shows that the reflectivity behavior can be mainly attributed to scattering rather than absorption for shallow snowpacks. The largest scattering coefficients and reflectivity occur at very small correlation lengths (approximately 10(exp -5 m) for frequencies higher than the IR band. In the microwave range, the largest scattering coefficients are found at millimeter wavelengths. For validation purposes, the ice-lamella model is coupled with a multilayer snow physics model to characterize the reflectivity response of realistic snow hydrological processes. The evolution of the coupled model simulated reflectivities in both the visible and the microwave bands is consistent with satellite-based reflectivity observations in the same frequencies. The model results are also compared with colocated in situ snow correlation length measurements (Cold Land Processes Field Experiment 2002-2003). The analysis and evaluation of model results indicate that the coupled multifrequency radiative transfer and snow hydrology modeling system can be used as a forward operator in a data-assimilation framework to predict the status of snow physical properties, including snow correlation length.

Radium isotope (223Ra, 224Ra, 226Ra and 228Ra) distribution near Brazil's largest port, Paranaguá Bay, Brazil

International Nuclear Information System (INIS)

Dias, Thais H.; Oliveira, Joselene de; Sanders, Christian J.; Carvalho, Franciane; Sanders, Luciana M.; Machado, Eunice C.; Sá, Fabian

2016-01-01

This work investigates the 223 Ra, 224 Ra, 226 Ra and 228 Ra isotope distribution in river, estuarine waters and sediments of the Paranaguá Estuarine Complex (PEC). The stratification of the Ra isotopes along water columns indicate differing natural sources. In sediments, the radium isotope activities was inversely proportional to the particle size. The highest concentrations of 223 Ra, 224 Ra, 226 Ra and 228 Ra in the water column were found in the bottom more saline waters and towards the inner of the estuary. These relatively high concentrations towards the bottom of the estuary may be attributed to the influence of tidally driven groundwater source and desorption from particles at the maximum turbidity zone. The apparent river water ages from the radium isotope ratios, 223 Ra/ 224 Ra and 223 Ra/ 228 Ra, indicate that the principal rivers that flow into the estuary have residence times from between 6 and 11 days. - Highlights: • Radium isotope concentrations were evaluated along a large estuarine system. • The radioactivity level in river, estuary and sediments was within a normal range. • Spatial distributions of site specific radionuclides have differing activities and sources.

Polar phonons in β-Ga2O3 studied by IR reflectance spectroscopy and first-principle calculations

Science.gov (United States)

Azuhata, Takashi; Shimada, Kazuhiro

2017-08-01

IR reflectance spectra of β-Ga2O3 are measured in the range from 400 to 1100 cm-1 using the (\\bar{2}01) and (010) planes for pure transverse Au- and Bu-mode phonons, respectively. The spectra measured using the (010) plane depend remarkably on the polarization direction of the incident light because of the monoclinic symmetry. Reflectance spectra simulated using parameters obtained from first-principle calculations are in good agreement with the experimental spectra. By adjusting the calculated phonon parameters so as to reproduce the experimental spectra, the polar phonon parameters were determined for six modes above 400 cm-1.

Diffuse reflectance relations based on diffusion dipole theory for large absorption and reduced scattering

NARCIS (Netherlands)

Bremmer, Rolf H.; van Gemert, Martin J. C.; Faber, Dirk J.; van Leeuwen, Ton G.; Aalders, Maurice C. G.

2013-01-01

Diffuse reflectance spectra are used to determine the optical properties of biological samples. In medicine and forensic science, the turbid objects under study often possess large absorption and/or scattering properties. However, data analysis is frequently based on the diffusion approximation to

Concentrations and activity ratios of 228Ra and 226Ra in surface seawater along the Pacific coast of Japan

International Nuclear Information System (INIS)

Ohta, T.; Mahara, Y.; Kubota, T.; Sato, J.; Gamo, T.

2011-01-01

We measured the 228 Ra/ 226 Ra activity ratios in surface seawater along the Pacific coast of Japan at five ports around the island of Izu-Oshima (n = 29), at Atami in Sagami Bay (n = 13), and at Umizuri Park in Tokyo Bay (n = 14). We also conducted these measurements along a transect from the open Pacific Ocean across the Kuroshio to the mouth of Tokyo Bay (n = 7). The activity ratios decreased with increasing salinity of the sampling sites. The 228 Ra/ 226 Ra activity ratios in surface seawater along the coast gradually decreased after at the end of autumn and were lowest in winter and the beginning of spring. The surface salinity along the coast decreased from summer into autumn and increased from winter to the beginning of spring. The activity ratios decreased with the increase of salinity. The variation in activity ratios at the three coastal sites is possibly caused by differing contributions of surface seawater from the Kuroshio and surrounding open ocean. The different patterns and ranges of variation in the 228 Ra/ 226 Ra activity ratios in surface seawater at Izu-Oshima, Atami, and Umizuri Park may reflect both the amount of water from the Kuroshio and vicinity, and the local bathymetry, because continental shelf sediment is the source of Ra isotopes in surface seawater. (orig.)

Free radicals in irradiated unstabilized polypropylene, as seen by diffuse reflection absorption-spectrophotometry

International Nuclear Information System (INIS)

Zagorski, Z.P.; Rafalski, A.

1998-01-01

The introduction of UV-Vis absorption spectrophotometry to the study of radiation chemistry of polymers has opened the possibility to investigate even very opaque samples. The virgin powder polypropylene, as obtained from the industrial production line, shows after irradiation unstable products of radiolysis. Until now they were investigated mainly by EPR method. Optical absorption spectra (by diffuse reflection spectrophotometry) contribute to better identification and study of changes in time, temperature and diffusion of reactive gases. Studying the formation of stable compounds, which do not produce EPR signal, we are able to examine these species on the basis of their electronic spectra. The most important results concern the peroxides in irradiated polypropylene

Thermally Resilient, Broadband Optical Absorber from UV to IR Derived from Carbon Nanostructures

Science.gov (United States)

Kaul, Anupama B.; Coles, James B.

2012-01-01

Optical absorber coatings have been developed from carbon-based paints, metal blacks, or glassy carbon. However, such materials are not truly black and have poor absorption characteristics at longer wavelengths. The blackness of such coatings is important to increase the accuracy of calibration targets used in radiometric imaging spectrometers since blackbody cavities are prohibitively large in size. Such coatings are also useful potentially for thermal detectors, where a broadband absorber is desired. Au-black has been a commonly used broadband optical absorber, but it is very fragile and can easily be damaged by heat and mechanical vibration. An optically efficient, thermally rugged absorber could also be beneficial for thermal solar cell applications for energy harnessing, particularly in the 350-2,500 nm spectral window. It has been demonstrated that arrays of vertically oriented carbon nanotubes (CNTs), specifically multi-walled-carbon- nanotubes (MWCNTs), are an exceptional optical absorber over a broad range of wavelengths well into the infrared (IR). The reflectance of such arrays is 100x lower compared to conventional black materials, such as Au black in the spectral window of 350-2,500 nm. Total hemispherical measurements revealed a reflectance of approximately equal to 1.7% at lambda approximately equal to 1 micrometer, and at longer wavelengths into the infrared (IR), the specular reflectance was approximately equal to 2.4% at lambda approximately equal to 7 micrometers. The previously synthesized CNTs for optical absorber applications were formed using water-assisted thermal chemical vapor deposition (CVD), which yields CNT lengths in excess of 100's of microns. Vertical alignment, deemed to be a critical feature in enabling the high optical absorption from CNT arrays, occurs primarily via the crowding effect with thermal CVD synthesized CNTs, which is generally not effective in aligning CNTs with lengths less than 10 m. Here it has been shown that the

226Ra, 228Ra and 228Ra/226Ra in surface marine sediment of Malaysia

International Nuclear Information System (INIS)

Mei-Wo Yii; Zal Uyun Wan-Mahmood

2013-01-01

Surface sediment samples were collected at the West (east coast and west coast of Peninsular Malaysia) and East (Sabah and Sarawak) Malaysia in several expeditions within August 2003 until June 2008 for determining the level of natural radium isotopes. Activity concentrations of 226 Ra and 228 Ra in surface marine sediment at 176 sampling stations were measured. The activity concentrations of both radionuclides in Malaysia (East and West Malaysia) display varied with the range from 9 to 158 Bq/kg dry wt. and 13 to 104 Bq/kg dry wt., respectively. Meanwhile, the ratio distributions of 228 Ra/ 226 Ra were ranged from 0.62 to 3.75. This indicated that the ratios were slightly high at west coast of Peninsular Malaysia compared to other regions (east coast of Peninsular Malaysia, Sabah and Sarawak). The variation of activity concentrations of 226 Ra and 228 Ra and its ratios were also supported by the statistical analyses of one-way ANOVA and t test at 95 % confidence level, whereby there were proved that the measured values were different between the regions. These different were strictly related to their half-life, potential input sources (included their parents, 238 U and 232 Th), parent's characteristic, the geological setting/formation of the study area, environment origin and behavior. (author)

Comparative kinetics of 47Ca, 85Sr and 226Ra in the freshwater turtle, Trachemys scripta

International Nuclear Information System (INIS)

Hinton, T.G.; Whicker, F.W.; Ibrahim, S.A.; Pinder, J.E. III

1992-01-01

The kinetics of 47 Ca, 85 Sr and 226 Ra were compared in the yellow-bellied slider, a common freshwater turtle of the southeastern USA. The absorption and elimination processes were examined as a function of stable dietary Ca, season, age and sex of the animals. Turtles were gavaged with radionuclides and serial whole-body analyses were performed on the live animals for up to 480 days. Only in the juvenile age class did reduced dietary Ca cause a significant increase in 85 Sr absorption. The absorption of 85 Sr and 226 Ra in the adult male, adult female and hatchling groups was unaffected by dietary Ca. Mean absorption was greater than that which has been reported for other organisms and significantly differed among isotopes. The high absorption values were not restricted to immatures, but continued into maturity. Elimination rates were not affected by the dietary treatment, nor were isotopic differences in elimination observed. Annual mean elimination rate constants pooled among animal groups, were 0.22 ± 0.07 for 85 Sr and 0.26 ± 0.18 for 226 Ra. Retention was strongly affected by season with the greatest elimination occurring in the summer and declining to levels that were not distinguishable from zero in the winter. Elimination rate constants for hatchlings were greater than for the other age groups. (author)

Verortung des Dichtens in Der Erzählung Meine Sprache und ich von Ilse Aichinger. Kūrybos raiškos vieta Ilzės Aichinger apsakyme Mano kalba ir Aš

Directory of Open Access Journals (Sweden)

Inga Bartkuvienė

2008-01-01

Full Text Available Straipsnyje analizuojamas kūrybos lokalizacijos klausimas objektu pasirinkus Ilzės Aichinger apsa­kymą Mano kalba ir aš. Susitelkta ties kalbos raiš­kos ženklais autoreferentiniame Aichinger rašyme. Siekis – atskleisti, kaip tekste išsidėsto, kaip veikia ir kokias reikšmes įgauna kalba, rašantysis, rašymas, raštas. Teorines prieigas teikia Martino Heideggerio kalbos filosofija bei Jacques Derrida „gramatologija“.Straipsnio dalyje „Riba kaip kalbos sritis“ apta­riamos kalbos sklaidos kūryboje bei kūrybos kalboje aktualizacijos. Kalba Aichinger tekste steigiasi opo­zicinių savybių sava / svetima sandūroje. Analizė pa­rodo, jog šią opoziciją eliminuoja besiplečiantis kity­bės atverčių laukas. Personifikuotos kalbos „sienos kirtimas“, „apsistojimas prie jūros“ erdviškai žymi ribinę situaciją, kuri yra kalbos būties sąlyga.Dalyje „Kūryba rašte“ gvildenami veikiančių figūrų implikuojami balso ir rašto santykiai: balsas yra kalbančiojo subjekto savybė, antropomorfinį pa­vidalą apsakyme įgijusi kalba prabilti atsisako. Jos būties būdas yra spektriškas, daugialypis, raštiškas. „Sustingęs rašale“ rašantysis praranda subjektyvybę ir išlieka tik kaip signatūros statusas, o „sustingusi rašale kalba“ grąžinama į rašto „būties namus“.

IR absorption spectrum (4200-3100 cm-1) of H2O and (H2O)2 in CCl4. Estimates of the equilibrium constant and evidence that the atmospheric water absorption continuum is due to the water dimer

International Nuclear Information System (INIS)

Nicolaisen, Flemming M.

2009-01-01

IR absorption spectra, 4200-3100 cm -1 , of water in CCl 4 solutions are presented. It is shown that for saturated solutions significant amounts of water are present as dimer (ca. 2%). The IR spectra of the monomer and dimer are retrieved. The integrated absorption coefficients of the monomer absorption are significantly enhanced relative to the gas phase values. The dimer spectrum consists of 5 bands, of which 4 were expected from data from cold beams and cold matrices. The origin of the 'extra' band is discussed. In addition it is argued that the dimer absorption bands intensities must be enhanced relative to the gas phase values. Based on recent calculations of band strengths, and observed frequency shifts relative to the gas phase, the intensity enhancement factors are estimated as well as the monomer/dimer equilibrium constant in CCl 4 solution at T=296 K (K c =1.29 mol -1 L). It is noted that the observed dimer spectrum has a striking resemblance with the water vapour continuum determined by Burch in 1985 which was recently remeasured by Paynter et al. and it is concluded that the atmospheric water absorption continuum in the investigated spectral region must be due to water dimer. Based on the newly published spectral data a revised value of the gas phase equilibrium constant is suggested (K p =0.035 atm -1 at T=296 K) as well as a value for the standard enthalpy of formation, ΔH 0 =15.4 kJ mol -1 .

Organic and inorganic interpretations of the martian UV-IR reflectance spectrum

Energy Technology Data Exchange (ETDEWEB)

Pang, K D; Ajello, J M [Jet Propulsion Lab., Pasadena, CA (USA); Chun, S F.S. [California Univ., San Francisco (USA). School of Medicine; Nansheng, Z [Beijing Planetarium (China); Minji, L [Beijing Glass Institute (China)

1982-01-07

The Viking gas chromatography-mass spectrometer analysis of martian soil samples are discussed, in particular why no organic molecules were detected at the landing sites, whether the sterility of the two sites is representative of the entire planet and if there are locations on Mars more conducive to the formation and preservation of organics. The destruction of organic compounds has been simulated in Mars-like laboratory conditions and the possible planetwide destructive mechanism considered. The UV and IR reflectance spectra of Mars has been re-examined for any evidence of organic molecules and an upper limit on the organic carbon content of average martian soil has been set. The results reveal that the average martian soil is organic-poor, makes an unfavourable habitat for life forms based on carbon chemistry, and there is no reason to believe that organic molecules are preferentially preserved anywhere on the planet.

Organic and inorganic interpretations of the martian UV-IR reflectance spectrum

International Nuclear Information System (INIS)

Pang, K.D.; Ajello, J.M.; Chun, S.F.S.; Minji, L.

1982-01-01

The Viking gas chromatography-mass spectrometer analysis of martian soil samples are discussed, in particular why no organic molecules were detected at the landing sites, whether the sterility of the two sites is representative of the entire planet and if there are locations on Mars more conducive to the formation and preservation of organics. The destruction of organic compounds has been simulated in Mars-like laboratory conditions and the possible planetwide destructive mechanism considered. The UV and IR reflectance spectra of Mars has been re-examined for any evidence of organic molecules and an upper limit on the organic carbon content of average martian soil has been set. The results reveal that the average martian soil is organic-poor, makes an unfavourable habitat for life forms based on carbon chemistry, and there is no reason to believe that organic molecules are preferentially preserved anywhere on the planet. (U.K.)

Differentiation of Body Fluid Stains on Fabrics Using External Reflection Fourier Transform Infrared Spectroscopy (FT-IR) and Chemometrics.

Science.gov (United States)

Zapata, Félix; de la Ossa, Ma Ángeles Fernández; García-Ruiz, Carmen

2016-04-01

Body fluids are evidence of great forensic interest due to the DNA extracted from them, which allows genetic identification of people. This study focuses on the discrimination among semen, vaginal fluid, and urine stains (main fluids in sexual crimes) placed on different colored cotton fabrics by external reflection Fourier transform infrared spectroscopy (FT-IR) combined with chemometrics. Semen-vaginal fluid mixtures and potential false positive substances commonly found in daily life such as soaps, milk, juices, and lotions were also studied. Results demonstrated that the IR spectral signature obtained for each body fluid allowed its identification and the correct classification of unknown stains by means of principal component analysis (PCA) and soft independent modeling of class analogy (SIMCA). Interestingly, results proved that these IR spectra did not show any bands due to the color of the fabric and no substance of those present in daily life which were analyzed, provided a false positive. © The Author(s) 2016.

Dvejų ir vienerių rūmų parlamentai: lyginamasis aspektas

OpenAIRE

Džiaugytė, Viktė

2011-01-01

Mokslinis darbas parengtas aktualia tema , kurios svarbumą lemia tai, jog panašių tyrimų nėra daug. Šiame darbe analizuojami ir lyginami dvejų ir vienerių rūmų parlamentai. Koncentruojamasi ne tiek į atskirų šalių parlamentus, kiek, pasitelkiant lyginamąją analizę, siekiama išsiaiškinti dvejų ir vienerių rūmų parlamentų skirtumą. Siekiant šio mokslinio darbo tikslo ir įgyvendinant uždavinius pasitelkiami sisteminės analizės, lyginamasis teisės, apibendrinimo, dokumentų analizės, istorinis ...

The 226Ra-Ba relationship in the North Atlantic during GEOTRACES-GA01

Science.gov (United States)

Le Roy, Emilie; Sanial, Virginie; Charette, Matthew A.; van Beek, Pieter; Lacan, François; Jacquet, Stéphanie H. M.; Henderson, Paul B.; Souhaut, Marc; García-Ibáñez, Maribel I.; Jeandel, Catherine; Pérez, Fiz F.; Sarthou, Géraldine

2018-05-01

We report detailed sections of radium-226 (226Ra, T1/2 = 1602 years) activities and barium (Ba) concentrations determined in the North Atlantic (Portugal-Greenland-Canada) in the framework of the international GEOTRACES program (GA01 section - GEOVIDE project, May-July 2014). Dissolved 226Ra and Ba are strongly correlated along the section, a pattern that may reflect their similar chemical behavior. Because 226Ra and Ba have been widely used as tracers of water masses and ocean mixing, we investigated their behavior more thoroughly in this crucial region for thermohaline circulation, taking advantage of the contrasting biogeochemical patterns existing along the GA01 section. We used an optimum multiparameter (OMP) analysis to distinguish the relative importance of physical transport (water mass mixing) from nonconservative processes (sedimentary, river or hydrothermal inputs, uptake by particles and dissolved-particulate dynamics) on the 226Ra and Ba distributions in the North Atlantic. Results show that the measured 226Ra and Ba concentrations can be explained by conservative mixing for 58 and 65 % of the samples, respectively, notably at intermediate depth, away from the ocean interfaces. 226Ra and Ba can thus be considered conservative tracers of water mass transport in the ocean interior on the space scales considered here, namely, on the order of a few thousand kilometers. However, regions in which 226Ra and Ba displayed nonconservative behavior and in some cases decoupled behaviors were also identified, mostly at the ocean boundaries (seafloor, continental margins and surface waters). Elevated 226Ra and Ba concentrations found in deepwater in the West European Basin suggest that lower Northeast Atlantic Deep Water (NEADWl) accumulates 226Ra and Ba from sediment diffusion and/or particle dissolution during transport. In the upper 1500 m of the West European Basin, deficiencies in 226Ra and Ba are likely explained by their incorporation in planktonic calcareous

TiO2-coated Hollow Glass Microspheres with Superhydrophobic and High IR-reflective Properties Synthesized by a Soft-chemistry Method.

Science.gov (United States)

Wong, Yinting; Zhong, Dan; Song, Aotian; Hu, Yan

2017-04-26

This manuscript proposes a soft-chemistry method to develop superhydrophobic and highly IR-reflective hollow glass microspheres (HGM). The anatase TiO2 and a superhydrophobic agent were coated on the HGM surface in one step. TBT and PFOTES were selected as the Ti source and the superhydrophobic agent, respectively. They were both coated on the HGM, and after the hydrothermal process, the TBT turned to anatase TiO2. In this way, a PFOTES/TiO2-coated HGM (MCHGM) was prepared. For comparison, PFOTES single-coated HGM (F-SCHGM) and TiO2 single-coated HGM (Ti-SCHGM) were synthesized as well. The PFOTES and TiO2 coatings on the HGM surface were demonstrated through X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive detector (EDS) characterizations. The MCHGM showed a higher contact angle (153°) but a lower sliding angle (16°) than F-SCHGM, with a contact angle of 141.2° and a sliding angle of 67°. In addition, both Ti-SCHGM and MCHGM displayed similar IR reflectivity values, which were about 5.8% higher than the original HGM and F-SCHGM. Also, the PFOTES coating barely changed the thermal conductivity. Therefore, F-SCHGM, with a thermal conductivity of 0.0479 W/(m·K), was quite like the original HGM, which was 0.0475 W/(m·K). MCHGM and Ti-SCHGM were also similar. Their thermal conductivity values were 0.0543 W/(m·K) and 0.0543 W/(m·K), respectively. The TiO2 coating slightly increased the thermal conductivity, but with the increase in reflectivity, the overall heat-insulation property was enhanced. Finally, since the IR-reflecting property is provided by the HGM coating, if the coating is fouled, the reflectivity decreases. Therefore, with the superhydrophobic coating, the surface is protected from fouling, and its lifetime is also prolonged.

Pulmonary cryptococcosis in rheumatoid arthritis (RA) patients: Comparison of imaging characteristics among RA, acquired immunodeficiency syndrome, and immunocompetent patients

International Nuclear Information System (INIS)

Yanagawa, Noriyo; Sakai, Fumikazu; Takemura, Tamiko; Ishikawa, Satoru; Takaki, Yasunobu; Hishima, Tsunekazu; Kamata, Noriko

2013-01-01

Purpose: The imaging characteristics of cryptococcosis in rheumatoid arthritis (RA) patients were analyzed by comparing them with those of acquired immunodeficiency syndrome (AIDS) and immunocompetent patients, and the imaging findings were correlated with pathological findings. Methods: Two radiologists retrospectively compared the computed tomographic (CT) findings of 35 episodes of pulmonary cryptococcosis in 31 patients with 3 kinds of underlying states (10 RA, 12 AIDS, 13 immunocompetent), focusing on the nature, number, and distribution of lesions. The pathological findings of 18 patients (8 RA, 2 AIDS, 8 immunocompetent) were analyzed by two pathologists, and then correlated with imaging findings. Results: The frequencies of consolidation and ground glass attenuation (GGA) were significantly higher, and the frequency of peripheral distribution was significantly lower in the RA group than in the immunocompetent group. Peripheral distribution was less common and generalized distribution was more frequent in the RA group than in the AIDS group. The pathological findings of the AIDS and immunocompetent groups reflected their immune status: There was lack of a granuloma reaction in the AIDS group, and a complete granuloma reaction in the immunocompetent group, while the findings of the RA group varied, including a complete granuloma reaction, a loose granuloma reaction and a hyper-immune reaction. Cases with the last two pathologic findings were symptomatic and showed generalized or central distribution on CT. Conclusion: Cryptococcosis in the RA group showed characteristic radiological and pathological findings compared with the other 2 groups

Pulmonary cryptococcosis in rheumatoid arthritis (RA) patients: Comparison of imaging characteristics among RA, acquired immunodeficiency syndrome, and immunocompetent patients

Energy Technology Data Exchange (ETDEWEB)

Yanagawa, Noriyo, E-mail: noriyo_yana@ybb.ne.jp [Departments of Radiology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-8-22, Honkomagome, Bunkyo-ku, Tokyo 113-8677 (Japan); Sakai, Fumikazu [Department of Diagnostic Radiology, Saitama Medical University International Medical Center, 1397-1 Yamane, Hidaka-shi, Saitama 350-1298 (Japan); Takemura, Tamiko [Department of Pathology, Japanese Red Cross Medical Center, 4-1-22 Hiroo, Shibuya-ku, Tokyo 150-8935 (Japan); Ishikawa, Satoru [Department of Respiratory Medicine, National Hospital Organization Chiba-East-Hospital, 673 Nitona-cho, Chuo-ku, Chiba-shi, Chiba 260-8712 (Japan); Takaki, Yasunobu [Departments of Radiology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-8-22, Honkomagome, Bunkyo-ku, Tokyo 113-8677 (Japan); Hishima, Tsunekazu [Department of Pathology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-8-22, Honkomagome, Bunkyo-ku, Tokyo 113-8677 (Japan); Kamata, Noriko [Departments of Radiology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-8-22, Honkomagome, Bunkyo-ku, Tokyo 113-8677 (Japan)

2013-11-01

Purpose: The imaging characteristics of cryptococcosis in rheumatoid arthritis (RA) patients were analyzed by comparing them with those of acquired immunodeficiency syndrome (AIDS) and immunocompetent patients, and the imaging findings were correlated with pathological findings. Methods: Two radiologists retrospectively compared the computed tomographic (CT) findings of 35 episodes of pulmonary cryptococcosis in 31 patients with 3 kinds of underlying states (10 RA, 12 AIDS, 13 immunocompetent), focusing on the nature, number, and distribution of lesions. The pathological findings of 18 patients (8 RA, 2 AIDS, 8 immunocompetent) were analyzed by two pathologists, and then correlated with imaging findings. Results: The frequencies of consolidation and ground glass attenuation (GGA) were significantly higher, and the frequency of peripheral distribution was significantly lower in the RA group than in the immunocompetent group. Peripheral distribution was less common and generalized distribution was more frequent in the RA group than in the AIDS group. The pathological findings of the AIDS and immunocompetent groups reflected their immune status: There was lack of a granuloma reaction in the AIDS group, and a complete granuloma reaction in the immunocompetent group, while the findings of the RA group varied, including a complete granuloma reaction, a loose granuloma reaction and a hyper-immune reaction. Cases with the last two pathologic findings were symptomatic and showed generalized or central distribution on CT. Conclusion: Cryptococcosis in the RA group showed characteristic radiological and pathological findings compared with the other 2 groups.

226Ra behavior in the Pee Dee river-Winyah Bay estuary

International Nuclear Information System (INIS)

Elsinger, R.J.; Moore, W.S.

1980-01-01

Concentrations of dissolved 226 Ra in Winyah Bay, South Carolina, and in the adjacent Atlantic Ocean are augmented by the desorption of radium from sediments in the low-salinity area of the estuary and diffusion from bottom sediments. Desorption of 226 Ra is reflected by lower concentrations in suspended sediments from higher-salinity regions of the estuary. Bottom sediments from the high-salinity region have lower 226 Ra/ 230 Th activity ratios than those from the low-salinity end. (orig./ME)

Mid-IR Absorption Cross-Section Measurements of Hydrocarbons

KAUST Repository

Alrefae, Majed Abdullah

2013-05-01

Laser diagnostics are fast-response, non-intrusive and species-specific tools perfectly applicable for studying combustion processes. Quantitative measurements of species concentration and temperature require spectroscopic data to be well-known at combustion-relevant conditions. Absorption cross-section is an important spectroscopic quantity and has direct relation to the species concentration. In this work, the absorption cross-sections of basic hydrocarbons are measured using Fourier Transform Infrared (FTIR) spectrometer, tunable Difference Frequency Generation laser and fixed wavelength helium-neon laser. The studied species are methane, methanol, acetylene, ethylene, ethane, ethanol, propylene, propane, 1-butene, n-butane, n-pentane, n-hexane, and n-heptane. The Fourier Transform Infrared (FTIR) spectrometer is used for the measurements of the absorption cross-sections and the integrated band intensities of the 13 hydrocarbons. The spectral region of the spectra is 2800 – 3400 cm-1 (2.9 – 3.6 μm) and the temperature range is 673 – 1100 K. These valuable data provide huge opportunities to select interference-free wavelengths for measuring time-histories of a specific species in a shock tube or other combustion systems. Such measurements can allow developing/improving chemical kinetics mechanisms by experimentally determining reaction rates. The Difference Frequency Generation (DFG) laser is a narrow line-width, tunable laser in the 3.35 – 3.53 μm wavelength region which contains strong absorption features for most hydrocarbons due to the fundamental C-H vibrating stretch. The absorption cross-sections of propylene are measured at seven different wavelengths using the DFG laser. The temperature range is 296 – 460 K which is reached using a Reflex Cell. The DFG laser is very attractive for kinetic studies in the shock tube because of its fast time response and the potential possibility of making species-specific measurements. The Fixed wavelength

The comparative kinetics of Ca, Sr, And Ra in a freshwater turtle, Trachemys scripta

International Nuclear Information System (INIS)

Hinton, T.G.

1989-01-01

The accumulation of 45 Ca, 47 Ca, 88 Sr, and 226 Ra was studied in the yellow-bellied slider, a common freshwater turtle of the Southeastern US. The author was particularly interested in testing the hypothesis of competitive inhibition, a concept whereby decreasing the intake of a stable dietary element increases the absorption and retention of chemically similar radionuclides. He established four specific hypotheses and examined the processes of absorption and elimination as a function of stable dietary calcium (2 and 20 mg g -1 ), season (summer, fall, winter and spring), and age and sex of the animals (hatchlings, juveniles, adult males, adult females, and gravid females). Turtles were gavaged with radionuclides and the gamma-emitting isotopes were detected during serial whole-body counts performed on the live animals for up to 480 d. The analysis of the beta-emitting 45 Ca was accomplished by chemical separation procedures. Data were fit to a two-component exponential retention model by nonlinear regression. The 10-fold reduction in dietary Ca did not affect the elimination rate constants, and increased the assimilation of Sr and Ra only within juveniles. For all animals the absorption of Ca was significantly greater than Sr, and likewise, Sr was greater than Ra. Mean absorptions were generally higher than values reported for other organisms. Unlike many other organisms, absorption rates did not decline at maturity. He suspects that high Ca demands in constructing and maintaining the massive shell, necessitated by the turtle's survival strategy, may contribute to the high absorption, as well as the lack of a decline at maturity. Elimination rate constants were greatest in the summer and declined to levels that were generally not distinguishable from zero in the spring, winter, and fall seasons

Parameter study of self-absorption effects in Total Reflection X-ray Fluorescence-X-ray Absorption Near Edge Structure analysis of arsenic

International Nuclear Information System (INIS)

Meirer, F.; Pepponi, G.; Streli, C.; Wobrauschek, P.; Kregsamer, P.; Zoeger, N.; Falkenberg, G.

2008-01-01

Total reflection X-ray Fluorescence (TXRF) analysis in combination with X-ray Absorption Near Edge Structure (XANES) analysis is a powerful method to perform chemical speciation studies at trace element levels. However, when measuring samples with higher concentrations and in particular standards, damping of the oscillations is observed. In this study the influence of self-absorption effects on TXRF-XANES measurements was investigated by comparing measurements with theoretical calculations. As(V) standard solutions were prepared at various concentrations and dried on flat substrates. The measurements showed a correlation between the damping of the oscillations and the As mass deposited. A Monte-Carlo simulation was developed using data of the samples shapes obtained from confocal white light microscopy. The results showed good agreement with the measurements; they confirmed that the key parameters are the density of the investigated atom in the dried residues and the shape of the residue, parameters that combined define the total mass crossed by a certain portion of the incident beam. The study presents a simple approach for an a priori evaluation of the self-absorption in TXRF X-ray absorption studies. The consequences for Extended X-ray Absorption Fine Structure (EXAFS) and XANES measurements under grazing incidence conditions are discussed, leading to the conclusion that the damping of the oscillations seems to make EXAFS of concentrated samples non feasible. For XANES 'fingerprint' analysis samples should be prepared with a deposited mass and sample shape leading to an acceptable absorption for the actual investigation

226Ra, 228Ra, 223Ra, and 224Ra in coastal waters with application to coastal dynamics and groundwater input

International Nuclear Information System (INIS)

Moore, W.S.

1997-01-01

Four radium isotopes offer promise in unraveling the complex dynamics of coastal ocean circulation and groundwater input. Each isotope is produced by decay of a thorium parent bound to sediment. The activities of these thorium isotopes and the sediment-water distribution coefficient for radium provide an estimate of the source function of each Ra isotope to the water. In salt marshes that receive little surface water input, Ra activities which exceed coastal ocean values must originate within the marsh. In North Inlet, South Carolina, the activities of 226 Ra exported from the marsh far exceed the activities generated within the marsh. To supply the exported activities, substantial groundwater input is required. In the coastal region itself, 226 Ra activities exceed the amount that can be supplied from rivers. Here also, substantial groundwater input is required. Within the coastal ocean, 223 Ra and 224 Ra may be used to determine mixing rates with offshore waters. Shore-perpendicular profiles of 223 Ra and 224 Ra show consistent trends which may be modeled as eddy diffusion coefficients of 350-540 m 2 s -1 . These coefficients allow an assessment of cross-shelf transport and provide further insight on the importance of groundwater to coastal regions. (author)

226Ra chronology of a coastal marine sediment

International Nuclear Information System (INIS)

Koide, M.; Bruland, K.; Goldberg, E.D.

1976-01-01

Unsupported 226 Ra (tsub (1/2) = 1620 years) in marine sediments can provide a basis for measuring rates of accumulation of the order of centimeters per thousand years. The excess radium apparently enters the sediments incorporated in phytoplankton. The sensitivity of the method depends upon the initial value of the unsupported 226 Ra and of the value of 230 Th, a parent of 226 Ra, in the sedimentary components. 226 Ra dating was applied to a sediment taken from the slope of the San Clemente Basin in the Southern California coastal region. Rates of sedimentation over two half-lives of the nuclide were found to be either 5.2 or 5.3 cm/1000 years depending upon which of two models for the geochronology is used. One model assumes that the 230 Th brings to the deposit an amount of 226 Ra in equilibrium with it. The other is based upon the growth of the 226 Ra from the 230 Th in the sedimentary components. 238+239 Pu and 210 Pb levels in the upper strata indicated sedimentation rates of the order of 100-500 cm/1000 years, i.e. much faster accumulations. It is suggested that these derived rates are spurious and reflect bioturbative activities of surface-living organisms. (Auth.)

Using mid-Infrared External Reflectance Spectroscopy to Distinguish Between Different Commercially Produced Poly[Methyl MethAcrylate] (PMMA) Samples - A Null Result

Science.gov (United States)

Fajardo, Mario; Neel, Christopher; Lacina, David

2017-06-01

We report (null) results of experiments testing the hypothesis that mid-infrared (mid-IR) spectroscopy can be used to distinguish samples of poly[methyl methacrylate] (PMMA) obtained from different commercial suppliers. This work was motivated by the desire for a simple non-destructive and non-invasive test for pre-sorting PMMA samples prior to use in shock and high-strain-rate experiments, where PMMA is commonly used as a standard material. We discuss: our choice of mid-IR external reflectance spectroscopy, our approach to recording reflectance spectra at near-normal (θ = 0 + / - 5 degree) incidence and for extracting the wavelength-weighted absorption spectrum from the raw reflectance data via a Kramers-Krönig analysis. We employ extensive signal, which necessitates adopting a special experimental protocol to mitigate the effects of instrumental drift. Finally, we report spectra of three PMMA samples with different commercial pedigrees, and show that they are virtually identical (+ / - 1 % error, 95% confidence); obviating the use of mid-IR reflectance spectroscopy to tell the samples apart.

On formation mechanism of Pd-Ir bimetallic nanoparticles through thermal decomposition of [Pd(NH3)4][IrCl6

Science.gov (United States)

Asanova, Tatyana I.; Asanov, Igor P.; Kim, Min-Gyu; Gerasimov, Evgeny Yu.; Zadesenets, Andrey V.; Plyusnin, Pavel E.; Korenev, Sergey V.

2013-10-01

The formation mechanism of Pd-Ir nanoparticles during thermal decomposition of double complex salt [Pd(NH3)4][IrCl6] has been studied by in situ X-ray absorption (XAFS) and photoelectron (XPS) spectroscopies. The changes in the structure of the Pd and Ir closest to the surroundings and chemical states of Pd, Ir, Cl, and N atoms were traced in the range from room temperature to 420 °C in inert atmosphere. It was established that the thermal decomposition process is carried out in 5 steps. The Pd-Ir nanoparticles are formed in pyramidal/rounded Pd-rich (10-200 nm) and dendrite Ir-rich (10-50 nm) solid solutions. A d charge depletion at Ir site and a gain at Pd, as well as the intra-atomic charge redistribution between the outer d and s and p electrons of both Ir and Pd in Pd-Ir nanoparticles, were found to occur.

On formation mechanism of Pd–Ir bimetallic nanoparticles through thermal decomposition of [Pd(NH3)4][IrCl6

International Nuclear Information System (INIS)

Asanova, Tatyana I.; Asanov, Igor P.; Kim, Min-Gyu; Gerasimov, Evgeny Yu.; Zadesenets, Andrey V.; Plyusnin, Pavel E.; Korenev, Sergey V.

2013-01-01

The formation mechanism of Pd–Ir nanoparticles during thermal decomposition of double complex salt [Pd(NH 3 ) 4 ][IrCl 6 ] has been studied by in situ X-ray absorption (XAFS) and photoelectron (XPS) spectroscopies. The changes in the structure of the Pd and Ir closest to the surroundings and chemical states of Pd, Ir, Cl, and N atoms were traced in the range from room temperature to 420 °C in inert atmosphere. It was established that the thermal decomposition process is carried out in 5 steps. The Pd–Ir nanoparticles are formed in pyramidal/rounded Pd-rich (10–200 nm) and dendrite Ir-rich (10–50 nm) solid solutions. A d charge depletion at Ir site and a gain at Pd, as well as the intra-atomic charge redistribution between the outer d and s and p electrons of both Ir and Pd in Pd–Ir nanoparticles, were found to occur.Graphical Abstract

Infrared reflection absorption spectroscopy study of radiation-heterogeneous processes in the system of aluminum-hexane

International Nuclear Information System (INIS)

Gadzhieva, N.N.; Rimikhanova, A.N.; Garibov, A.A.

2004-01-01

Full text: Infrared reflection absorption spectroscopy (IRRAS) was applied to study the regularities of radiation conversion of hexane on the surface of aluminum. The research object was the thin polished aluminum plate by mark of AD-00 with reflection coefficient R=0.8†0.85 in infrared range λ=2.2†15 μ . As adsorbate unsaturated vapors of spectroscopy clear hexane were used. The absorption of hexane (C 2 H 14 ) was being studied manometric at pressures P=(0.1†1.0)·10 2 Pa , what corresponded to monolayer value of 1-10. The samples were irradiated with γ-quanta of 60 Co with D=1.03 Gy·s -1 doze rate. Infrared reflection spectrum when linear-polarized radiation fall on the sample under angle ψ=10 o was measured by spectrophotometer 'Specord 71 JR' in diapason of 4000-650cm -1 at the temperature by mean of special reflecting arrangements. Formation of molecular hydrogen (H 2 ) and other gaseous products of decomposition were controlled by chromotographical and infrared spectroscopical methods. The analysis of hexane infrared absorption spectra after radiation-stimulated adsorption on the surface of aluminum, points out the formation of H-bonded hydrocarbon complex ( ν∼2680cm -1 ) with much loosening of C-H bond (the molecular form of absorption) and the possibility of proceeding dissociative absorption with formation of metal-alkyls (ν∼2880, 2920, 2970 cm -1 ). Probability of the last mentioned process, which proceeds in the most defective centers, increases with increasing of γ-radiation doze. It was established that the radiation processes in hetero system Al-ads.C 6 H 14 accelerate the radiolysis of hexane. At all these the radiation decomposition of hexane in hetero system Al-ads.C 6 H 14 is accompanied by formation the surface hydrides (ν∼1700-2000 cm -1 ), acetylene (ν∼3200-3300 cm -1 ), ethylene (ν∼980 cm -1 ), and also gaseous products of molecular hydrogen decomposition (H 2 ) and hydrocarbons C 1 -C 5 (bands with maxima 770, 790

Thermal-to-visible transducer (TVT) for thermal-IR imaging

Science.gov (United States)

Flusberg, Allen; Swartz, Stephen; Huff, Michael; Gross, Steven

2008-04-01

We have been developing a novel thermal-to-visible transducer (TVT), an uncooled thermal-IR imager that is based on a Fabry-Perot Interferometer (FPI). The FPI-based IR imager can convert a thermal-IR image to a video electronic image. IR radiation that is emitted by an object in the scene is imaged onto an IR-absorbing material that is located within an FPI. Temperature variations generated by the spatial variations in the IR image intensity cause variations in optical thickness, modulating the reflectivity seen by a probe laser beam. The reflected probe is imaged onto a visible array, producing a visible image of the IR scene. This technology can provide low-cost IR cameras with excellent sensitivity, low power consumption, and the potential for self-registered fusion of thermal-IR and visible images. We will describe characteristics of requisite pixelated arrays that we have fabricated.

INFRARED ABSORPTION LINES TOWARD NGC 7538 IRS 1: ABUNDANCES OF H{sub 2}, H{sub 3}{sup +}, AND CO

Energy Technology Data Exchange (ETDEWEB)

Goto, Miwa [Universitäts-Sternwarte München, Scheinerstr. 1, D-81679 Munich (Germany); Geballe, T. R. [Gemini Observatory, 670 North A‘ohoku Place, Hilo, HI 96720 (United States); Usuda, Tomonori, E-mail: mgoto@usm.lmu.de, E-mail: tgeballe@gemini.edu, E-mail: usuda@naoj.org [Subaru Telescope, 650 North A‘ohoku Place, Hilo, HI 96720 (United States)

2015-06-10

We report high-resolution near-infrared absorption spectroscopy of H{sub 2}, H{sub 3}{sup +}, and CO toward the young high mass object NGC 7538 IRS 1. The v = 1–0 H{sub 2} S(0) line and lines in the CO v = 2–0 band were detected; the v = 1–0 H{sub 2} S(1) line and the v = 1–0 H{sub 3}{sup +} lines [R(1, 1){sup l}, R(1, 0), R(1, 1){sup u}] were not detected. The line of sight traverses two clouds, with temperatures 45 and 259 K and with roughly equal column densities of CO. Assuming that H{sub 2} is at the same temperature as CO and that the two species are uniformly mixed, [H{sub 2}]/[CO] = 3600 ± 1200. NGC 7538 is the most distant object from the Galactic center for which [H{sub 2}]/[CO] has been directly measured using infrared absorption spectroscopy.

Determination of 226Ra and 228Ra in gypsum

International Nuclear Information System (INIS)

Godoy, J.M.

1989-01-01

The content of 226 Ra and 228 Ra in different samples of phosphogypsum and three samples of gypsite were determined by gamma spectroscopy. For 226 Ra the 295, 352 and 609 KeV lines and for 228 Ra the 911 and 969 KeV lines were used. The specific activities values ranged from 0.36 to 22.8 pCi/g for 226 Ra and 0.90 to 10.3 pCi/g for 228 Ra. The contribution of a sypsum roof-covering to the 222 Rn concentration in a room was estimated, based on the highest value reported. (author) [pt

High-Resolution IR Absorption Spectroscopy of Polycyclic Aromatic Hydrocarbons in the 3-micrometers Region: Role of Periphery

Science.gov (United States)

Maltseva, Elena; Petrignani, Annemieke; Candian, Alessandra; Mackie, Cameron J.; Huang, Xinchuan; Lee, Timothy J.; Tielens, Alexander G. G. M.; Oomens, Jos; Buma, Wybren Jan

2017-01-01

In this work we report on high-resolution IR absorption studies that provide a detailed view on how the peripheral structure of irregular polycyclic aromatic hydrocarbons (PAHs) affects the shape and position of their 3-micrometers absorption band. To this purpose we present mass-selected, high-resolution absorption spectra of cold and isolated phenanthrene, pyrene, benz[a]antracene, chrysene, triphenylene, and perylene molecules in the 2950-3150 per cm range. The experimental spectra are compared with standard harmonic calculations, and anharmonic calculations using a modified version of the SPECTRO program that incorporates a Fermi resonance treatment utilizing intensity redistribution. We show that the 3-micrometers region is dominated by the effects of anharmonicity, resulting in many more bands than would have been expected in a purely harmonic approximation. Importantly, we find that anharmonic spectra as calculated by SPECTRO are in good agreement with the experimental spectra. Together with previously reported high-resolution spectra of linear acenes, the present spectra provide us with an extensive dataset of spectra of PAHs with a varying number of aromatic rings, with geometries that range from open to highly-condensed structures, and featuring CH groups in all possible edge configurations. We discuss the astrophysical implications of the comparison of these spectra on the interpretation of the appearance of the aromatic infrared 3-micrometers band, and on features such as the two-component emission character of this band and the 3-micrometers emission plateau.

Simultaneous measurement of thermal diffusivity and effective infrared absorption coefficient in IR semitransparent and semiconducting n-CdMgSe crystals using photothermal radiometry

Energy Technology Data Exchange (ETDEWEB)

Pawlak, M., E-mail: mpawlak@fizyka.umk.pl [Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziądzka 5/7, Toruń (Poland); Maliński, M. [Department of Electronics and Computer Science, Koszalin University of Technology, 2 Śniadeckich St., Koszalin 75-453 (Poland)

2015-01-10

Highlights: • The new method of determination of the effective infrared absorption coefficient is presented. • The method can be used for transparent samples for the excitation radiation. • The effect of aluminum foil on the PTR signal in a transmission configuration is discussed. - Abstract: In this paper we propose a new procedure of simultaneous estimation of the effective infrared optical absorption coefficient and the thermal diffusivity of solid state samples using the photothermal infrared radiometry method in the transmission configuration. The proposed procedure relies on the analysis of the frequency dependent signal obtained from the samples covered with thin aluminum foil. This method can be applied for both optically opaque and transparent samples. The proposed method is illustrated with the results of the thermal diffusivity and the effective IR absorption coefficient obtained for several Cd{sub 1−x}Mg{sub x}Se crystals.

Discrimination of Chinese Sauce liquor using FT-IR and two-dimensional correlation IR spectroscopy

Science.gov (United States)

Sun, Su-Qin; Li, Chang-Wen; Wei, Ji-Ping; Zhou, Qun; Noda, Isao

2006-11-01

We applied the three-step IR macro-fingerprint identification method to obtain the IR characteristic fingerprints of so-called Chinese Sauce liquor (Moutai liquor and Kinsly liquor) and a counterfeit Moutai. These fingerprints can be used for the identification and discrimination of similar liquor products. The comparison of their conventional IR spectra, as the first step of identification, shows that the primary difference in Sauce liquor is the intensity of characteristic peaks at 1592 and 1225 cm -1. The comparison of the second derivative IR spectra, as the second step of identification, shows that the characteristic absorption in 1400-1800 cm -1 is substantially different. The comparison of 2D-IR correlation spectra, as the third and final step of identification, can discriminate the liquors from another direction. Furthermore, the method was successfully applied to the discrimination of a counterfeit Moutai from the genuine Sauce liquor. The success of the three-step IR macro-fingerprint identification to provide a rapid and effective method for the identification of Chinese liquor suggests the potential extension of this technique to the identification and discrimination of other wine and spirits, as well.

Estuarine geochemistry of 224Ra, 226Ra, and 222Rn

International Nuclear Information System (INIS)

Elsinger, R.J.

1982-01-01

Desorption from river borne sediments is the most likely source of the excess 226 Ra. Laboratory mixing experiments on Pee Dee River sediments show an increase in 226 Ra desorption with increasing salinities with maximum desorption occurring at or above 20 0 /oo salinity. Desorption and diffusion are the sources for 226 Ra in the estuarine systems. In Winyah Bay the 228 Ra/ 226 Ra activity ratio does not change significantly with salinity, averaging around 1.4, indicating desorption as the major source of 228 Ra. In the Yangtze River the 228 Ra/ 226 Ra activity ratio is constant (approx.1.90) until increasing linearly above 16 0 /oo. A diffusive flux from regeneration by 232 Th decay in shelf sediments is the source of the increase. In Delaware Bay 228 Ra increases faster than 226 Ra in the less than or equal to22 0 /oo water, indicating a source in addition to desorption. The increase can be balanced by a 0.33 dpm/cm 2 -year flux over the upper part of the Bay where fine grained sediments predominate. 224 Ra behavior is controlled by its 3.64 day half-life. In Winyah Bay a flux of around 0.4 dpm/cm 2 -day is necessary to support the standing crop of non-desorbed 224 Ra in the water column. In Delaware Bay the nearly constant 224 Ra in concentration over the 2.5 0 /oo to 12 0 /oo salinity range are maintained by regeneration from 228 Th in the turbidity maximum zones and diffusion from bottom sediments. Water leaving on ebb tide from a salt marsh on Delaware Bay had increases in all three radium isotopes ( 224 Ra > 228 Ra > 226 Ra) compared to water coming in on the flood tide. Excess 222 Rn concentrations in a fresh water section of the Pee Dee River show a decreasing downstream gradient. Using these gradients to determine evasion rates, stagnant film thicknesses range from 21μ to 62μ

SQL užklausų rašymo gebėjimų vertinimo sistema

OpenAIRE

Ruzgys, Mindaugas

2014-01-01

Faktiškai kiekviena šiuolaikinė IS naudoja duomenų bazes, kad saugoti informaciją. Šiuo metu populiariausios reliacinės duomenų bazių valdymo sistemos, kur užklausos rašomos SQL kalba. Todėl kiekvienas programuotojas privalo gebėti rašyti SQL užklausas Rinkoje labai mažai sistemų, skirtų MySQL žinių testavimui, kurios atitinka visus keliamus reikalavimus ir yra nemokamos. Most of bigger web solutions use databases for data storage.This is why all programmers must be familiar with SQL and i...

Preparation and microwave-infrared absorption of reduced graphene oxide/Cu-Ni ferrite/Al2O3 composites

Science.gov (United States)

De-yue, Ma; Xiao-xia, Li; Yu-xiang, Guo; Yu-run, Zeng

2018-01-01

Reduced graphene oxide (RGO)/Cu-Ni ferrite/Al2O3 composite was prepared by solvothermal method, and its properties were characterized by SEM, x-ray diffraction, energy-dispersive x-ray spectroscopy and FTIR. The electromagnetic parameters in 2-18 GHz and mid-infrared (IR) spectral transmittance of the composite were measured, respectively. The results show that Cu0.7Ni0.3Fe2O4 nanoparticles with an average size of tens nanometers adsorb on surface of RGO, and meanwhile, Al2O3 nanoparticles adhere to the surface of Cu0.7Ni0.3Fe2O4 nanoparticles and RGO. The composite has both dielectric and magnetic loss mechanism. Its reflection loss is lower than -19 dB in 2-18 GHz, and the maximum of -23.2 dB occurs at 15.6 GHz. With the increasing of Al2O3 amount, its reflection loss becomes lower and the maximum moves towards low frequency slightly. Compared with RGO/Cu-Ni ferrite composites, its magnetic loss and reflection loss slightly reduce with the increasing of Al2O3 amount, and the maximum of reflection loss shifts from a low frequency to a high one. However, its broadband IR absorption is significantly enhanced owing to nano-Al2O3. Therefore, RGO/Cu-Ni ferrite/Al2O3 composites can be used as excellent broadband microwave and IR absorbing materials, and maybe have broad application prospect in electromagnetic shielding, IR absorbing and coating materials.

Comparative kinetics of sup 47 Ca, sup 85 Sr and sup 226 Ra in the freshwater turtle, Trachemys scripta

Energy Technology Data Exchange (ETDEWEB)

Hinton, T.G. (Savannah River Ecology Lab., Aiken, SC (United States) Colorado State Univ., Fort Collins, CO (United States)); Whicker, F.W.; Ibrahim, S.A. (Colorado State Univ., Fort Collins, CO (United States)); Pinder, J.E. III (Savannah River Ecology Lab., Aiken, SC (United States))

1992-01-01

The kinetics of {sup 47}Ca, {sup 85}Sr and {sup 226}Ra were compared in the yellow-bellied slider, a common freshwater turtle of the southeastern USA. The absorption and elimination processes were examined as a function of stable dietary Ca, season, age and sex of the animals. Turtles were gavaged with radionuclides and serial whole-body analyses were performed on the live animals for up to 480 days. Only in the juvenile age class did reduced dietary Ca cause a significant increase in {sup 85}Sr absorption. The absorption of {sup 85}Sr and {sup 226}Ra in the adult male, adult female and hatchling groups was unaffected by dietary Ca. Mean absorption was greater than that which has been reported for other organisms and significantly differed among isotopes. The high absorption values were not restricted to immatures, but continued into maturity. Elimination rates were not affected by the dietary treatment, nor were isotopic differences in elimination observed. Annual mean elimination rate constants pooled among animal groups, were 0.22 {+-} 0.07 for {sup 85}Sr and 0.26 {+-} 0.18 for {sup 226}Ra. Retention was strongly affected by season with the greatest elimination occurring in the summer and declining to levels that were not distinguishable from zero in the winter. Elimination rate constants for hatchlings were greater than for the other age groups. (author).

Library search with regular reflectance IR spectra

International Nuclear Information System (INIS)

Staat, H.; Korte, E.H.; Lampen, P.

1989-01-01

Characterisation in situ for coatings and other surface layers is generally favourable, but a prerequisite for precious items such as art objects. In infrared spectroscopy only reflection techniques are applicable here. However for attenuated total reflection (ATR) it is difficult to obtain the necessary optical contact of the crystal with the sample, when the latter is not perfectly plane or flexible. The measurement of diffuse reflectance demands a scattering sample and usually the reflectance is very poor. Therefore in most cases one is left with regular reflectance. Such spectra consist of dispersion-like feature instead of bands impeding their interpretation in the way the analyst is used to. Furthermore for computer search in common spectral libraries compiled from transmittance or absorbance spectra a transformation of the reflectance spectra is needed. The correct conversion is based on the Kramers-Kronig transformation. This somewhat time - consuming procedure can be speeded up by using appropriate approximations. A coarser conversion may be obtained from the first derivative of the reflectance spectrum which resembles the second derivative of a transmittance spectrum. The resulting distorted spectra can still be used successfully for the search in peak table libraries. Experiences with both transformations are presented. (author)

FTIR measurements of mid-IR absorption spectra of gaseous fatty acid methyl esters at T=25–500 °C

International Nuclear Information System (INIS)

Campbell, M.F.; Freeman, K.G.; Davidson, D.F.; Hanson, R.K.

2014-01-01

Gas-phase mid-infrared (IR) absorption spectra (2500–3400 cm −1 ) for eleven fatty acid methyl esters (FAMEs) have been quantitatively measured at temperatures between 25 and 500 °C using an FTIR spectrometer with a resolution of 1 cm −1 . Using these spectra, the absorption cross section at 3.39 μm, corresponding to the monochromatic output of a helium–neon laser, is reported for each of these fuels as a function of temperature. The data indicate that the 3.39 μm cross section values of saturated FAMEs vary linearly with the logarithm of the number of C-H bonds in the molecule. - Highlights: • Infrared spectra of 11 fatty acid methyl esters (C 3 –C 11 ) have been measured. • A linear relationship for predicting 3.39 μm cross section values is proposed. • A molecule’s integrated area is linearly related to its number of C-H bonds. • Mono-unsaturation decreases cross section values

Colostral immunoglobulins absorption in Canchim and Nelore calves Absorção de imunoglobulinas do colostro em bezerros das raças Canchim e Nelore

Directory of Open Access Journals (Sweden)

Raul Machado Neto

2004-12-01

Full Text Available The efficiency of absorption of colostral immunoglobulins was evaluated in five Canchim and seven Nelore calves. They received colostrum pools with concentration of 70.20 ± 6.14 mg/mL through esofageal feeder at 2, 12, 24 and 36 hours after birth. The immunoglobulins concentrations of the pools were estimated through specific gravity and measured by radial immunodifusion. In the blood collection at birth and during the first 70 days of life, the total protein was assayed by biuret method and the immunoglobulins were assayed by radial immunodifusion. Data were analysed as a randomized split-plot statistical model. The highest concentrations of serum immunoglobulins and total protein were observed at 24 hours of age. No significant differences (P>0.5484 were observed for immunoglobulins concentration at 24 hours, with concentrations of 28.80 ± 7.24 mg/mL for Canchim and 27.32 ± 9.54 mg/mL for Nelore. The efficiency for immunoglobulins absorption was not significantly different (P>0.8715 between breeds, 64.04 ± 7.74% for Canchim and 62.30 ± 6.93% for Nelore. The lack of statistical significance persisted until the fourtieth day of life, period of maternal immunoglobulin predominance in the calves blood circulation. In the following period, from 40 to 70 days of age, phase of establishment of the endogenous production of immunoglobulin, differences in the IgG concentrations between the two groups were detected refflecting a possible breed effect difference. The process of colostral IgG absorption by the newborn calves was not affected by breed. The differences between breeds in the calves serum IgG were related to the phase of endogenous production of antibodies.A eficiência de absorção de imunoglobulinas do colostro foi avaliada em cinco bezerros da raça Canchim e sete bezerros da raça Nelore. Os bezerros receberam colostro de "pools" com concentração média de 70,20 ± 6,14 mg/mL, por sonda esofagiana, às 2, 12, 24 e 36 horas após o

Kino repertuāra pārlūks Android ierīcēm

OpenAIRE

Zvirbulis, Jānis

2013-01-01

Kvalifikācijas darbā “Kino repertuāra pārlūks Android ierīcēm” tiek aprakstīta Android lietojumprogrammas “Kino repertuāra pārlūks” izstrāde un funkcionalitāte. Lietotne paredzēta kinoteātra repertuāra aplūkošanai izmantojot planšetdatorus un mobilos tālruņus, kas darbojas ar Android operētājsistēmu. Tā ir domāta kā parocīgāka alternatīva filmu apraksta un seansa laiku uzzināšanai caur kinoteātra mājaslapu, skrejlapām vai afišām. Atslēgvārdi: Android, filmas, pārlūks....

HIGH-RESOLUTION IR ABSORPTION SPECTROSCOPY OF POLYCYCLIC AROMATIC HYDROCARBONS IN THE 3 μ m REGION: ROLE OF PERIPHERY

Energy Technology Data Exchange (ETDEWEB)

Maltseva, Elena; Petrignani, Annemieke; Buma, Wybren Jan [University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Candian, Alessandra; Mackie, Cameron J.; Tielens, Alexander G. G. M. [Leiden Observatory, Niels Bohrweg 2, 2333 CA Leiden (Netherlands); Huang, Xinchuan [SETI Institute, 189 Bernardo Avenue, Suite 100, Mountain View, CA 94043 (United States); Lee, Timothy J. [NASA Ames Research Center, Moffett Field, California 94035-1000 (United States); Oomens, Jos, E-mail: w.j.buma@uva.nl [Radboud University, Toernooiveld 7, 6525 ED Nijmegen (Netherlands)

2016-11-01

In this work we report on high-resolution IR absorption studies that provide a detailed view on how the peripheral structure of irregular polycyclic aromatic hydrocarbons (PAHs) affects the shape and position of their 3 μ m absorption band. For this purpose, we present mass-selected, high-resolution absorption spectra of cold and isolated phenanthrene, pyrene, benz[a]antracene, chrysene, triphenylene, and perylene molecules in the 2950–3150 cm{sup −1} range. The experimental spectra are compared with standard harmonic calculations and anharmonic calculations using a modified version of the SPECTRO program that incorporates a Fermi resonance treatment utilizing intensity redistribution. We show that the 3 μ m region is dominated by the effects of anharmonicity, resulting in many more bands than would have been expected in a purely harmonic approximation. Importantly, we find that anharmonic spectra as calculated by SPECTRO are in good agreement with the experimental spectra. Together with previously reported high-resolution spectra of linear acenes, the present spectra provide us with an extensive data set of spectra of PAHs with a varying number of aromatic rings, with geometries that range from open to highly condensed structures, and featuring CH groups in all possible edge configurations. We discuss the astrophysical implications of the comparison of these spectra on the interpretation of the appearance of the aromatic infrared 3 μ m band, and on features such as the two-component emission character of this band and the 3 μ m emission plateau.

RA Reactor; Reaktor RA

Energy Technology Data Exchange (ETDEWEB)

NONE

1989-07-01

This chapter includes the following: General description of the RA reactor, organization of work, responsibilities of leadership and operators team, regulations concerning operation and behaviour in the reactor building, regulations for performing experiments, regulations and instructions for inserting samples into experimental channels. [Serbo-Croat] Ovo (prvo) poglavlje sadrzi sledece: Opis reaktora RA; semu organizacije rada i rukovodjenja; prava i duznosti direktora i rukovodioca pogona reaktora, propise o rezimu rada i kretanja u zgradi reaktora, propise o izvodjenju eksperimenata, propise o unosenju uzoraka u eksperimentalne kanale reaktora.

UV, visible, and near-IR reflectivity data for magnetic soils/rocks from Brazil

Science.gov (United States)

Vempati, R. K.; Morris, R. V.; Lauer, H. V., Jr.; Coey, J. M. D.

1991-01-01

The objective is to obtain UV, visible, and near-IR reflectivity spectra for several magnetic Brazilian soils/rocks and compare them to corresponding data for Mars to see if these materials satisfy both magnetic and spectral constraints for Mars. Selected physical properties of the magnetic Brazilian soils/rocks are presented. In general, the spectral features resulting from ferric crystal-field transitions are much better defined in the spectra of the magnetic Brazilian soils/rocks than in Martian spectral data. Presumably, this results from a relatively higher proportion of crystalline ferric oxides for the former. The apparent masking of the spectral signature of maghemite by hematite or goethite for the Brazilian samples implies the magnetic and spectral constraints for Mars can be decoupled. That is, maghemite may be present in magnetically-significant but optically-insignificant amounts compared to crystalline hematite.

Ternary electrocatalysts for oxidizing ethanol to carbon dioxide: making ir capable of splitting C-C bond.

Science.gov (United States)

Li, Meng; Cullen, David A; Sasaki, Kotaro; Marinkovic, Nebojsa S; More, Karren; Adzic, Radoslav R

2013-01-09

Splitting the C-C bond is the main obstacle to electrooxidation of ethanol (EOR) to CO(2). We recently demonstrated that the ternary PtRhSnO(2) electrocatalyst can accomplish that reaction at room temperature with Rh having a unique capability to split the C-C bond. In this article, we report the finding that Ir can be induced to split the C-C bond as a component of the ternary catalyst. We characterized and compared the properties of several carbon-supported nanoparticle (NP) electrocatalysts comprising a SnO(2) NP core decorated with multimetallic nanoislands (MM' = PtIr, PtRh, IrRh, PtIrRh) prepared using a seeded growth approach. An array of characterization techniques were employed to establish the composition and architecture of the synthesized MM'/SnO(2) NPs, while electrochemical and in situ infrared reflection absorption spectroscopy studies elucidated trends in activity and the nature of the reaction intermediates and products. Both EOR reactivity and selectivity toward CO(2) formation of several of these MM'/SnO(2)/C electrocatalysts are significantly higher compared to conventional Pt/C and Pt/SnO(2)/C catalysts. We demonstrate that the PtIr/SnO(2)/C catalyst with high Ir content shows outstanding catalytic properties with the most negative EOR onset potential and reasonably good selectivity toward ethanol complete oxidation to CO(2).

On formation mechanism of Pd-Ir bimetallic nanoparticles through thermal decomposition of [Pd(NH{sub 3}){sub 4}][IrCl{sub 6}

Energy Technology Data Exchange (ETDEWEB)

Asanova, Tatyana I., E-mail: nti@niic.nsc.ru; Asanov, Igor P. [Nikolaev Institute of Inorganic Chemistry SB RAS (Russian Federation); Kim, Min-Gyu [Pohang University of Science and Technology, Beamline Research Division (Korea, Republic of); Gerasimov, Evgeny Yu. [Boreskov Institute of Catalysis SB RAS (Russian Federation); Zadesenets, Andrey V.; Plyusnin, Pavel E.; Korenev, Sergey V. [Nikolaev Institute of Inorganic Chemistry SB RAS (Russian Federation)

2013-10-15

The formation mechanism of Pd-Ir nanoparticles during thermal decomposition of double complex salt [Pd(NH{sub 3}){sub 4}][IrCl{sub 6}] has been studied by in situ X-ray absorption (XAFS) and photoelectron (XPS) spectroscopies. The changes in the structure of the Pd and Ir closest to the surroundings and chemical states of Pd, Ir, Cl, and N atoms were traced in the range from room temperature to 420 Degree-Sign C in inert atmosphere. It was established that the thermal decomposition process is carried out in 5 steps. The Pd-Ir nanoparticles are formed in pyramidal/rounded Pd-rich (10-200 nm) and dendrite Ir-rich (10-50 nm) solid solutions. A d charge depletion at Ir site and a gain at Pd, as well as the intra-atomic charge redistribution between the outer d and s and p electrons of both Ir and Pd in Pd-Ir nanoparticles, were found to occur.Graphical Abstract.

Behavior of 226Ra in the Mississippi River mixing zone

Science.gov (United States)

Moore, Daniel G.; Scott, Martha R.

1986-12-01

The behavior of 226Ra in the Mississippi River mixing zone is strongly nonconservative and includes desorption similar to that reported for the Hudson, Pee Dee, and Amazon rivers. However, dissolved and desorbed 226Ra concentrations in the Mississippi are 2 to 5 times greater than in the other rivers at the same salinity. Radium concentrations vary inversely with the water discharge rate. The 226Ra desorption maximum occurs at a salinity of 5.0, much lower than the 18 to 28 salinity values for the maxima of the other three rivers. High concentrations of dissolved 226Ra (up to 82 dpm per 100 L) and the low salinity values for the desorption maximum in the Mississippi River result from three major factors. Suspended sediments include a large fraction of montmorillonite, which gives the sediment a high cation exchange capacity, 0.54 meq/g. The average suspended sediment load is large, about 510 mg/L, and contains 1.9 dpm/g desorbable 226Ra. The dissolved 226Ra river water end-member (9.6 dpm per 100 L) is higher than in surface seawater. The annual contribution of 226Ra to the ocean from the Mississippi River is 3.7 × 1014 dpm/yr, based on data from three cruises. Evidence of flux of 226Ra from estuarine and shelf sediments is common in vertical profile sampling of the deltaic waters but is not reflected in calculations made with an "apparent" river water Ra value extrapolated to zero salinity.

Bio-inspired, subwavelength surface structures to control reflectivity, transmission, and scattering in the infrared

Science.gov (United States)

Lora Gonzalez, Federico

Controlling the reflection of visible and infrared (IR) light at interfaces is extremely important to increase the power efficiency and performance of optics, electro-optical and (thermo)photovoltaic systems. The eye of the moth has evolved subwavelength protuberances that increase light transmission into the eye tissue and prevent reflection. The subwavelength protuberances effectively grade the refractive index from that of air (n=1) to that of the tissue (n=1.4), making the interface gradual, suppressing reflection. In theory, the moth-eye (ME) structures can be implemented with any material platform to achieve an antireflectance effect by scaling the pitch and size of protuberances for the wavelength range of interest. In this work, a bio-inspired, scalable and substrate-independent surface modification protocol was developed to realize broadband antireflective structures based on the moth-eye principle. Quasi-ordered ME arrays were fabricated in IR relevant materials using a colloidal lithography method to achieve highly efficient, omni-directional transmission of mid and far infrared (IR) radiation. The effect of structure height and aspect ratio on transmittance and scattering is explored, with discussion on experimental techniques and effective medium theory (EMT). The highest aspect ratio structures (AR = 9.4) achieved peak single-side transmittance of 98%, with >85% transmission for lambda = 7--30 microns. A detailed photon balance constructed by transmission, forward scattering, specular reflection and diffuse reflection measurements to quantify optical losses due to near-field effects will be discussed. In addition, angle-dependent transmission measurements showed that moth-eye structures provide superior antireflective properties compared to unstructured interfaces over a wide angular range (0--60° incidence). Finally, subwavelength ME structures are incorporated on a Si substrate to enhance the absorption of near infrared (NIR) light in PtSi films to

Lyties įtaka pratimų sukeltai raumens pažaidai ir atsigavimui

OpenAIRE

Inokaitis, Hermanas

2008-01-01

Vieningos nuomonės dėl hormonų įtakos raumenų nuovargiui ir atsigavimui nėra. Kai kuriuose literatūros šaltiniuose teigiama, kad moterims nuovargis pasireiškia vėliau nei vyrams, kitose, jog skirtumo tarp lyčių nėra (Clark, 1986; Hunter & Enoka, 2001; Clark et al., 2003). Vienose mokslinėse publikacijose teigiama, kad moterų kreatinkinazės aktyvumas po ekscentrinio fizinio krūvio buvo mažesnis nei vyrų (Staron et al., 1992). Kituose mokslo darbuose nurodoma, kad atliktų tyrimų duomenimis, kre...

From patients with arthralgia, pre-RA and recently diagnosed RA: What is the current status of understanding RA pathogenesis?

NARCIS (Netherlands)

M. Molendijk (Marlieke); J.M.W. Hazes (Mieke); E.W. Lubberts (Erik)

2018-01-01

textabstractIt is believed that therapy for rheumatoid arthritis (RA) is the most effective and beneficial within a short time frame around RA diagnosis. This insight has caused a shift from research in patients with established RA to patients at risk of developing RA and recently diagnosed

Simultaneous infrared and UV-visible absorption spectra of matrix-isolated carbon vapor

Science.gov (United States)

Kurtz, Joe; Huffman, Donald R.

1989-01-01

Carbon molecules were suggested as possible carriers of the diffuse interstellar bands. In particular, it was proposed that the 443 nm diffuse interstellar band is due to the same molecule which gives rise to the 447 nm absorption feature in argon matrix-isolated carbon vapor. If so, then an associated C-C stretching mode should be seen in the IR. By doing spectroscopy in both the IR and UV-visible regions on the same sample, the present work provides evidence for correlating UV-visible absorption features with those found in the IR. Early data indicates no correlation between the strongest IR feature (1997/cm) and the 447 nm band. Correlation with weaker IR features is being investigated.

Validation of 226Ra, 228Ra and 210Pb measurements in soil and sediment samples through high resolution gamma ray spectrometry

International Nuclear Information System (INIS)

Dias, Danila Carrijo da Silva; Silva, Nivaldo Carlos da; Bonifacio, Rodrigo Leandro; Guerrero, Eder Tadeu Zenun

2013-01-01

Radionuclides found in ore extraction waste materials are a great source of concern regarding public health and environmental safety. One technique to determine the concentration of substances is high resolution gamma ray spectrometry using HPGe. Validating a measurement technique is essential to warrant high levels of quality to any scientific work. The Laboratory of Pocos de Caldas of the Brazilian Commission for Nuclear Energy partakes into a Quality Management System project, seeking Accreditation under ISO/IEC 17025 through the validation of techniques of chemical and radiometric analysis of environmental samples from water, soil and sediment. The focus of the Radon Laboratory at LAPOC is validation of Ra-226, Ra-228 and Pb-210 concentration determinations in soil and sediment through a gamma spectrometer system. The stages of this validation process included sample reception and preparation, detector calibration and sample analyses. Dried samples were sealed in metallic containers and analyzed after radioactive equilibrium between Ra-226 and daughters Pb-214 and Bi-214. Gamma spectrometry was performed using CANBERRA HPGe detector and gamma spectrum software Genie 2000. The photo peaks used for Ra-226 determination were 609 keV and 1020 keV of Bi-214 and 351 keV of Pb-214. For the Ra-228 determination a photopeak of 911 keV was used from its short half-life daughter Ac-228 (T1/2 = 6.12 h). For Pb-210, the photopeak of 46.5 keV was used, which, due to the low energy, self-absorption correction was needed. Parameters such as precision, bias/accuracy, linearity, detection limit and uncertainty were evaluated for that purpose. The results have pointed to satisfying results. (author)

Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Spectroscopy as a Forensic Method to Determine the Composition of Inks Used to Print the United States One-cent Blue Benjamin Franklin Postage Stamps of the 19th Century.

Science.gov (United States)

Brittain, Harry G

2016-01-01

Through the combined use of infrared (IR) absorption spectroscopy and attenuated total reflectance (ATR) sampling, the composition of inks used to print the many different types of one-cent Benjamin Franklin stamps of the 19th century has been established. This information permits a historical evaluation of the formulations used at various times, and also facilitates the differentiation of the various stamps from each other. In two instances, the ink composition permits the unambiguous identification of stamps whose appearance is identical, and which (until now) have only been differentiated through estimates of the degree of hardness or softness of the stamp paper, or through the presence or absence of a watermark in the paper. In these instances, the use of ATR Fourier transform infrared spectroscopy (FT-IR) spectroscopy effectively renders irrelevant two 100-year-old practices of stamp identification. Furthermore, since the use of ATR sampling makes it possible to obtain the spectrum of a stamp still attached to its cover, it is no longer necessary to identify these blue Franklin stamps using their cancellation dates. © The Author(s) 2015.

A fibre-coupled UHV-compatible variable angle reflection-absorption UV/visible spectrometer

Science.gov (United States)

Stubbing, J. W.; Salter, T. L.; Brown, W. A.; Taj, S.; McCoustra, M. R. S.

2018-05-01

We present a novel UV/visible reflection-absorption spectrometer for determining the refractive index, n, and thicknesses, d, of ice films. Knowledge of the refractive index of these films is of particular relevance to the astrochemical community, where they can be used to model radiative transfer and spectra of various regions of space. In order to make these models more accurate, values of n need to be recorded under astronomically relevant conditions, that is, under ultra-high vacuum (UHV) and cryogenic cooling. Several design considerations were taken into account to allow UHV compatibility combined with ease of use. The key design feature is a stainless steel rhombus coupled to an external linear drive (z-shift) allowing a variable reflection geometry to be achieved, which is necessary for our analysis. Test data for amorphous benzene ice are presented as a proof of concept, the film thickness, d, was found to vary linearly with surface exposure, and a value for n of 1.43 ± 0.07 was determined.

Multiple reflections and Fresnel absorption in an actual 3D keyhole during deep penetration laser welding

Energy Technology Data Exchange (ETDEWEB)

Jin Xiangzhong [Laser Institute of Hunan University, Changsha, Hunan, 410082 (China); Berger, Peter [Institut fuer Strahlwerkzeuge (IFSW), University of Stuttgart, Pfaffenwaldring 43, 70569 Stuttgart (Germany); Graf, Thomas [Institut fuer Strahlwerkzeuge (IFSW), University of Stuttgart, Pfaffenwaldring 43, 70569 Stuttgart (Germany)

2006-11-07

In laser welding experiments of glass, keyhole shapes are observed by two high-speed cameras from two perpendicular directions. From the obtained keyhole pictures, it can be seen that in medium- and low-speed laser penetration welding, the main distortion of the keyhole is not the section metamorphosis from rotational symmetry, but the bending of its centre line. Based on such a keyhole photograph, the keyhole profiles and its centre line are determined by the method of polynomial fitting. Then, under the assumption of a circular cross section at each depth of the keyhole, the behaviour of the laser beam in the keyhole is analysed by tracing a ray of light using geometrical optics theory; the Fresnel absorption and multiple reflections in the keyhole are systematically studied, and the laser intensities absorbed on the keyhole walls are calculated. The absorbed laser intensity is not distributed uniformly on the keyhole wall. The keyhole wall absorbs laser intensity mainly on the half-part of the keyhole wall near the front wall. Because of the high absorptivity of the glass, Fresnel absorption from the first incidence of a laser beam plays a dominant role in the final laser intensity distribution on the keyhole wall, multiple reflections have some minor effects on the intensity distribution on the bottom part of the keyhole.

Polarization control of intermediate state absorption in resonance-mediated multi-photon absorption process

International Nuclear Information System (INIS)

Xu, Shuwu; Yao, Yunhua; Jia, Tianqing; Ding, Jingxin; Zhang, Shian; Sun, Zhenrong; Huang, Yunxia

2015-01-01

We theoretically and experimentally demonstrate the control of the intermediate state absorption in an (n + m) resonance-mediated multi-photon absorption process by the polarization-modulated femtosecond laser pulse. An analytical solution of the intermediate state absorption in a resonance-mediated multi-photon absorption process is obtained based on the time-dependent perturbation theory. Our theoretical results show that the control efficiency of the intermediate state absorption by the polarization modulation is independent of the laser intensity when the transition from the intermediate state to the final state is coupled by the single-photon absorption, but will be affected by the laser intensity when this transition is coupled by the non-resonant multi-photon absorption. These theoretical results are experimentally confirmed via a two-photon fluorescence control in (2 + 1) resonance-mediated three-photon absorption of Coumarin 480 dye and a single-photon fluorescence control in (1 + 2) resonance-mediated three-photon absorption of IR 125 dye. (paper)

Determination of sup 226 Ra and sup 228 Ra in gypsum

Energy Technology Data Exchange (ETDEWEB)

Godoy, J M [Instituto de Radioprotecao e Dosimetria, Rio de Janeiro, RJ (Brazil)

1989-01-01

The content of {sup 226}Ra and {sup 228}Ra in different samples of phosphogypsum and three samples of gypsite were determined by gamma spectroscopy. For {sup 226}Ra the 295, 352 and 609 KeV lines and for {sup 228}Ra the 911 and 969 KeV lines were used. The specific activities values ranged from 0.36 to 22.8 pCi/g for {sup 226}Ra and 0.90 to 10.3 pCi/g for {sup 228}Ra. The contribution of a sypsum roof-covering to the {sup 222}Rn concentration in a room was estimated, based on the highest value reported. (author).

Influence of composition and roughness on the pigment mapping of paintings using mid-infrared fiberoptics reflectance spectroscopy (mid-IR FORS) and multivariate calibration.

Science.gov (United States)

Sessa, Clarimma; Bagán, Héctor; García, Jose Francisco

2014-10-01

Mid-infrared fiberoptics reflectance spectroscopy (mid-IR FORS) is a very interesting technique for artwork characterization purposes. However, the fact that the spectra obtained are a mixture of surface (specular) and volume (diffuse) reflection is a significant drawback. The physical and chemical features of the artwork surface may produce distortions in the spectra that hinder comparison with reference databases acquired in transmission mode. Several studies attempted to understand the influence of the different variables and propose procedures to improve the interpretation of the spectra. This article is focused on the application of mid-IR FORS and multivariate calibration to the analysis of easel paintings. The objectives are the evaluation of the influence of the surface roughness on the spectra, the influence of the matrix composition for the classification of unknown spectra, and the capability of obtaining pigment composition mappings. A first evaluation of a fast procedure for spectra management and pigment discrimination is discussed. The results demonstrate the capability of multivariate methods, principal component analysis (PCA), and partial least squares discrimination analysis (PLS-DA), to model the distortions of the reflectance spectra and to delimitate and discriminate areas of uniform composition. The roughness of the painting surface is found to be an important factor affecting the shape and relative intensity of the spectra. A mapping of the major pigments of a painting is possible using mid-IR FORS and PLS-DA when the calibration set is a palette that includes the potential pigments present in the artwork mixed with the appropriate binder and that shows the different paint textures.

Atmospheric pressure and temperature profiling using near IR differential absorption lidar

Science.gov (United States)

Korb, C. L.; Schwemmer, G. K.; Dombrowski, M.; Weng, C. Y.

1983-01-01

The present investigation is concerned with differential absorption lidar techniques for remotely measuring the atmospheric temperature and pressure profile, surface pressure, and cloud top pressure-height. The procedure used in determining the pressure is based on the conduction of high-resolution measurements of absorption in the wings of lines in the oxygen A band. Absorption with respect to these areas is highly pressure sensitive in connection with the mechanism of collisional line broadening. The method of temperature measurement utilizes a determination of the absorption at the center of a selected line in the oxygen A band which originates from a quantum state with high ground state energy.

Detection of Soluble and Fixed NH4+ in Clay Minerals by DTA and IR Reflectance Spectroscopy : A Potential Tool for Planetary Surface Exploration

Science.gov (United States)

Janice, Bishop; Banin, A.; Mancinelli, R. L.; Klovstad, M. R.; DeVincenzi, Donald L. (Technical Monitor)

2001-01-01

Nitrogen is an essential element for life. It is the only element among the six major biogenic elements, C, O, S, O, P, H, whose presence in the Martian soil has not been positively and directly established. We describe here a study assessing the ability to detect NH4 in soils by two methods: differential thermal analysis (DTA) and infrared (IR) reflectance spectroscopy. Four standard clay minerals (kaolinite, montmorillonite, illite and attapulgite) and an altered tephra sample from Mauna Kea were treated with NH4 in this study. Samples of the NH4-treated and leached clays were analyzed by DTA and infrared (IR) reflectance spectroscopy to quantify the delectability of soluble and sorbed/fixed NH4. An exotherm at 270-280 C was clearly detected in the DTA curves of NH4-treated (non-leached) samples. This feature is assigned to the thermal decomposition reaction of NH4. Spectral bands observed at 1.56, 2.05, 2.12, 3.06, 3.3, 3.5, 5.7 and 7.0 microns in the reflectance spectra of NH4-treated and leached samples are assigned to the sorbed/fixed ammonium in the clays. The montmorillonite has shown the most intense absorbance due to fixed ammonium among the leached samples in this study, as a result of its high cation sorption capacity. It is concluded that the presence of sorbed or fixed NH4 in clays may be detected by infrared (IR) reflectance or emission spectroscopy. Distinction between soluble and sorbed NH4 may be achieved through the presence or absence of several spectral features assigned to the sorbed NH4 moietyi and, specifically, by use of the 4.2 micrometer feature assigned to solution NH4. Thermal analyses furnish supporting evidence of ammonia in our study through detection of N released at temperatures of 270-330 C. Based on these results it is estimated that IR spectra measured from a rover should be able to detect ammonia if present above 20 mg NH4/g sample in the surface layers. Orbital IR spectra and thermal analyses measured on a rover may be able to

Observational Evidence Linking Interstellar UV Absorption to PAH Molecules

Energy Technology Data Exchange (ETDEWEB)

Blasberger, Avi; Behar, Ehud; Perets, Hagai B. [Department of Physics, Technion (Israel); Brosch, Noah [The Wise Observatory and School of Physics and Astronomy, Tel Aviv University (Israel); Tielens, Alexander G. G. M. [Leiden Observatory, Leiden University (Netherlands)

2017-02-20

The 2175 Å UV extinction feature was discovered in the mid-1960s, yet its physical origin remains poorly understood. One suggestion is absorption by polycyclic aromatic hydrocarbon (PAH) molecules, which is supported by theoretical molecular structure computations and by laboratory experiments. PAHs are positively detected by their 3.3, 6.2, 7.7, 8.6, 11.3, and 12.7 μ m IR emission bands, which are specified by their modes of vibration. A definitive empirical link between the 2175 Å UV extinction and the IR PAH emission bands, however, is still missing. We present a new sample of hot stars that have both 2175 Å absorption and IR PAH emission. We find significant shifts of the central wavelength of the UV absorption feature, up to 2350 Å, but predominantly in stars that also have IR PAH emission. These UV shifts depend on stellar temperature in a fashion that is similar to the shifts of the 6.2 and 7.7 μ m IR PAH bands, that is, the features are increasingly more redshifted as the stellar temperature decreases, but only below ∼15 kK. Above 15 kK both UV and IR features retain their nominal values. Moreover, we find a suggestive correlation between the UV and IR shifts. We hypothesize that these similar dependences of both the UV and IR features on stellar temperature hint at a common origin of the two in PAH molecules and may establish the missing link between the UV and IR observations. We further suggest that the shifts depend on molecular size, and that the critical temperature of ∼15 kK above which no shifts are observed is related to the onset of UV-driven hot-star winds and their associated shocks.

Observational Evidence Linking Interstellar UV Absorption to PAH Molecules

International Nuclear Information System (INIS)

Blasberger, Avi; Behar, Ehud; Perets, Hagai B.; Brosch, Noah; Tielens, Alexander G. G. M.

2017-01-01

The 2175 Å UV extinction feature was discovered in the mid-1960s, yet its physical origin remains poorly understood. One suggestion is absorption by polycyclic aromatic hydrocarbon (PAH) molecules, which is supported by theoretical molecular structure computations and by laboratory experiments. PAHs are positively detected by their 3.3, 6.2, 7.7, 8.6, 11.3, and 12.7 μ m IR emission bands, which are specified by their modes of vibration. A definitive empirical link between the 2175 Å UV extinction and the IR PAH emission bands, however, is still missing. We present a new sample of hot stars that have both 2175 Å absorption and IR PAH emission. We find significant shifts of the central wavelength of the UV absorption feature, up to 2350 Å, but predominantly in stars that also have IR PAH emission. These UV shifts depend on stellar temperature in a fashion that is similar to the shifts of the 6.2 and 7.7 μ m IR PAH bands, that is, the features are increasingly more redshifted as the stellar temperature decreases, but only below ∼15 kK. Above 15 kK both UV and IR features retain their nominal values. Moreover, we find a suggestive correlation between the UV and IR shifts. We hypothesize that these similar dependences of both the UV and IR features on stellar temperature hint at a common origin of the two in PAH molecules and may establish the missing link between the UV and IR observations. We further suggest that the shifts depend on molecular size, and that the critical temperature of ∼15 kK above which no shifts are observed is related to the onset of UV-driven hot-star winds and their associated shocks.

Use of total internal reflection Raman (TIR) and attenuated total reflection infrared (ATR-IR) spectroscopy to analyze component separation in thin offset ink films after setting on coated paper surfaces.

Science.gov (United States)

Kivioja, Antti; Hartus, Timo; Vuorinen, Tapani; Gane, Patrick; Jääskeläinen, Anna-Stiina

2013-06-01

The interactive behavior of ink constituents with porous substrates during and after the offset print process has an important effect on the quality of printed products. To help elucidate the distribution of ink components between the retained ink layer and the substrate, a variety of spectroscopic and microscopic analysis techniques have been developed. This paper describes for the first time the use of total internal reflection (TIR) Raman spectroscopy to analyze the penetration behavior of separated offset ink components (linseed oil, solid color pigment) in coated papers providing chemically intrinsic information rapidly, nondestructively, and with minimal sample preparation. In addition, the already widely applied technique of attenuated total reflection infrared spectroscopy (ATR-IR) was evaluated in parallel and compared. The results of the ATR-IR Raman clearly revealed an improvement in uppermost depth resolution compared with values previously published from other nondestructive techniques, and the method is shown to be capable of providing new knowledge of the setting of thin (0.25-2 μm) offset ink films, allowing the spreading and the penetration behavior on physically different paper coating surfaces to be studied.

Application of Fourier transform infrared (FT-IR) spectroscopy in determination of microalgal compositions.

Science.gov (United States)

Meng, Yingying; Yao, Changhong; Xue, Song; Yang, Haibo

2014-01-01

Fourier transform infrared spectroscopy (FT-IR) was applied in algal strain screening and monitoring cell composition dynamics in a marine microalga Isochrysis zhangjiangensis during algal cultivation. The content of lipid, carbohydrate and protein of samples determined by traditional methods had validated the accuracy of FT-IR method. For algal screening, the band absorption ratios of lipid/amide I and carbo/amide I from FT-IR measurements allowed for the selection of Isochrysis sp. and Tetraselmis subcordiformis as the most potential lipid and carbohydrate producers, respectively. The cell composition dynamics of I. zhangjiangensis measured by FT-IR revealed the diversion of carbon allocation from protein to carbohydrate and neutral lipid when nitrogen-replete cells were subjected to nitrogen limitation. The carbo/amide I band absorption ratio had also been demonstrated to depict physiological status under nutrient stress in T. subcordiformis. FT-IR serves as a tool for the simultaneous measurement of lipid, carbohydrate, and protein content in cell. Copyright © 2013 Elsevier Ltd. All rights reserved.

Multi-pollutants sensors based on near-IR telecom lasers and mid-IR difference frequency generation: development and applications

International Nuclear Information System (INIS)

Cousin, J.

2006-12-01

At present the detection of VOC and other anthropic trace pollutants is an important challenge in the measurement of air quality. Infrared spectroscopy, allowing spectral regions rich in molecular absorption to be probed, is a suitable technique for in-situ monitoring of the air pollution. Thus the aim of this work was to develop instruments capable of detecting multiple pollutants for in-situ monitoring by IR spectroscopy. A first project benefited from the availability of the telecommunications lasers emitting in near-IR. This instrument was based on an external cavity diode laser (1500 - 1640 nm) in conjunction with a multipass cell (100 m). The detection sensitivity was optimised by employing a balanced detection and a sweep integration procedure. The instrument developed is deployable for in-situ measurements with a sensitivity of -8 cm -1 Hz -1/2 and allowed the quantification of chemical species such as CO 2 , CO, C 2 H 2 , CH 4 and the determination of the isotopic ratio 13 CO 2 / 12 CO 2 in combustion environment The second project consisted in mixing two near-IR fiber lasers in a non-linear crystal (PPLN) in order to produce a laser radiation by difference frequency generation in the middle-IR (3.15 - 3.43 μm), where the absorption bands of the molecules are the most intense. The first studies with this source were carried out on detection of ethylene (C 2 H 4 ) and benzene (C 6 H 6 ). Developments, characterizations and applications of these instruments in the near and middle IR are detailed and the advantages of the 2 spectral ranges is highlighted. (author)

RA Reactor; Reaktor RA

Energy Technology Data Exchange (ETDEWEB)

NONE

1978-02-15

In addition to basic characteristics of the RA reactor, organizational scheme and financial incentives, this document covers describes the state of the reactor components after 18 years of operation, problems concerned with obtaining the licence for operation with 80% fuel, problems of spent fuel storage in the storage pool of the reactor building and the need for renewal of reactor equipment, first of all instrumentation. [Serbo-Croat] Pored osnovnih karakeristika reaktora RA, organizacije rada i finansijskih pokazatelja, razmatra se stanje opreme reaktora nakon 18 godina rada, pitanja dozvole za rad sa 80% obogacenim gorivom, problem skladistenja isluzenog goriva u bazenu zgrade reaktora i potreba za obnavljanjem komponenti opreme, pre svega elektronske.

Exploration of faint absorption bands in the reflectance spectra of the asteroids by method of optimal smoothing: Vestoids

Science.gov (United States)

Shestopalov, D. I.; McFadden, L. A.; Golubeva, L. F.

2007-04-01

An optimization method of smoothing noisy spectra was developed to investigate faint absorption bands in the visual spectral region of reflectance spectra of asteroids and the compositional information derived from their analysis. The smoothing algorithm is called "optimal" because the algorithm determines the best running box size to separate weak absorption bands from the noise. The method is tested for its sensitivity to identifying false features in the smoothed spectrum, and its correctness of forecasting real absorption bands was tested with artificial spectra simulating asteroid reflectance spectra. After validating the method we optimally smoothed 22 vestoid spectra from SMASS1 [Xu, Sh., Binzel, R.P., Burbine, T.H., Bus, S.J., 1995. Icarus 115, 1-35]. We show that the resulting bands are not telluric features. Interpretation of the absorption bands in the asteroid spectra was based on the spectral properties of both terrestrial and meteorite pyroxenes. The bands located near 480, 505, 530, and 550 nm we assigned to spin-forbidden crystal field bands of ferrous iron, whereas the bands near 570, 600, and 650 nm are attributed to the crystal field bands of trivalent chromium and/or ferric iron in low-calcium pyroxenes on the asteroids' surface. While not measured by microprobe analysis, Fe 3+ site occupancy can be measured with Mössbauer spectroscopy, and is seen in trace amounts in pyroxenes. We believe that trace amounts of Fe 3+ on vestoid surfaces may be due to oxidation from impacts by icy bodies. If that is the case, they should be ubiquitous in the asteroid belt wherever pyroxene absorptions are found. Pyroxene composition of four asteroids of our set is determined from the band position of absorptions at 505 and 1000 nm, implying that there can be orthopyroxenes in all range of ferruginosity on the vestoid surfaces. For the present we cannot unambiguously interpret of the faint absorption bands that are seen in the spectra of 4005 Dyagilev, 4038

Distribution of 226Ra and 228Ra in drinking water and dose assessment

International Nuclear Information System (INIS)

Ajay Kumar; Sugandhi, S.; Usha, N.; Rupali, K.; Gurg, R.P.

2002-01-01

The radioactivity concentrations of 226 Ra and 228 Ra have been analysed in 123 drinking water samples received from different regions of India. The maximum concentrations of 226 Ra and 228 Ra in drinking water are 8 mBq/l and 11.5 mBq/l respectively. The higher doses due to intake of 228 Ra through drinking water suggests that 228 Ra should also be measured in the assessment of ingestion dose to the population. The estimated committed effective doses range from 0.082 to 2.45 μSv/year and from 1.53 to 8.81 μSv/year for the ingestion of 226 Ra and 228 Ra respectively. (author)

Phosphoproteome and Transcriptome of RA-Responsive and RA-Resistant Breast Cancer Cell Lines.

Directory of Open Access Journals (Sweden)

Marilyn Carrier

Full Text Available Retinoic acid (RA, the main active vitamin A metabolite, controls multiple biological processes such as cell proliferation and differentiation through genomic programs and kinase cascades activation. Due to these properties, RA has proven anti-cancer capacity. Several breast cancer cells respond to the antiproliferative effects of RA, while others are RA-resistant. However, the overall signaling and transcriptional pathways that are altered in such cells have not been elucidated. Here, in a large-scale analysis of the phosphoproteins and in a genome-wide analysis of the RA-regulated genes, we compared two human breast cancer cell lines, a RA-responsive one, the MCF7 cell line, and a RA-resistant one, the BT474 cell line, which depicts several alterations of the "kinome". Using high-resolution nano-LC-LTQ-Orbitrap mass spectrometry associated to phosphopeptide enrichment, we found that several proteins involved in signaling and in transcription, are differentially phosphorylated before and after RA addition. The paradigm of these proteins is the RA receptor α (RARα, which was phosphorylated in MCF7 cells but not in BT474 cells after RA addition. The panel of the RA-regulated genes was also different. Overall our results indicate that RA resistance might correlate with the deregulation of the phosphoproteome with consequences on gene expression.

LO-TO splittings, effective charges and interactions in electro-optic meta-nitroaniline crystal as studied by polarized IR reflection and transmission spectra

Science.gov (United States)

Szostak, M. M.; Le Calvé, N.; Romain, F.; Pasquier, B.

1994-10-01

The polarized IR reflection spectra of the meta-nitroaniline ( m-NA) single crystal along the a, b and c crystallographic axes as well as the b and c polarized transmission spectra have been measured in the 100-400 cm -1 region. The LO-TO splitting values have been calculated from the reflection spectra by fitting them with the four parameter dielectric function. The dipole moment derivatives, relevant to dynamic effective charges, of the vibrations have also been calculated and used to check the applicability of the oriented gas model (OGM) to reflection spectra. The discrepancies from the OGM have been discussed in terms of vibronic couplings, weak hydrogen bondings (HB) and intramolecular charge transfer.

The RaDIATE High-Energy Proton Materials Irradiation Experiment at the Brookhaven Linac Isotope Producer Facility

Energy Technology Data Exchange (ETDEWEB)

Ammigan, Kavin; et al.

2017-05-01

The RaDIATE collaboration (Radiation Damage In Accelerator Target Environments) was founded in 2012 to bring together the high-energy accelerator target and nuclear materials communities to address the challenging issue of radiation damage effects in beam-intercepting materials. Success of current and future high intensity accelerator target facilities requires a fundamental understanding of these effects including measurement of materials property data. Toward this goal, the RaDIATE collaboration organized and carried out a materials irradiation run at the Brookhaven Linac Isotope Producer facility (BLIP). The experiment utilized a 181 MeV proton beam to irradiate several capsules, each containing many candidate material samples for various accelerator components. Materials included various grades/alloys of beryllium, graphite, silicon, iridium, titanium, TZM, CuCrZr, and aluminum. Attainable peak damage from an 8-week irradiation run ranges from 0.03 DPA (Be) to 7 DPA (Ir). Helium production is expected to range from 5 appm/DPA (Ir) to 3,000 appm/DPA (Be). The motivation, experimental parameters, as well as the post-irradiation examination plans of this experiment are described.

Measurement of 226Ra, 228Ra, 137CS and 40K in edible parts of two types of leafy vegetables cultivated in Tehran province-Iran and resultant annual ingestion radiation dose

International Nuclear Information System (INIS)

Changizi, V.; Jafarpoor, Z.; Naseri, M.

2010-01-01

The sources of radioactivity in the environment have natural; terrestrial and extraterrestrial. and anthropogenic origins. Plants may get radioactive nuclides in two ways: (i) by the deposition of radioactive fallout, (ii) by absorption from the soil. Materials and Methods: The Concentrations of the natural radionuclides ( 226 Ra, 228 Ra, 40 K) and the artificial radionuclide ( 137 CS) in leek and parsley in Tehran province-Iran were determined using high-purity Ge detectors. Also the effective dose due to the ingestion of such vegetables by the population of Tehran province was studied. Results: The average value of radionuclide concentrations in parsley samples were measured 177.69 ± 12.47 mBq kg -1 fresh for 226 Ra; 349.62 ± 28.42 mBq kg -1 fresh for 228 Ra; 187364.6 mBq kg 1 fresh for 40 K. The average value of radionuclide concentrations in leek samples were measured 94.31 ± 6.46 mBq kg -1 fresh for 226 Ra; 207.47 ± 19.46 mBq kg -1 fresh for 228 Ra; 174555 ± 1704.21 mBq kg -1 fresh for 40 K. The concentrations of 137 Cs in most of Parsley and Leek samples were below the minimum detectable activity. Conclusion: The Average 226 Ra and 228 Ra activities in 29 leek and parsley samples were about 2.63 and 6.78 times the reference values, respectively. The annual effective dose resulting from the studied radionuclides for the adult population in Tehran province were found to be safe in comparison with normal background areas.

Infrared (IR) photon-sensitive spectromicroscopy in a cryogenic environment

Science.gov (United States)

Pereverzev, Sergey

2016-06-14

A system designed to suppress thermal radiation background and to allow IR single-photon sensitive spectromicroscopy of small samples by using both absorption, reflection, and emission/luminescence measurements. The system in one embodiment includes: a light source; a plurality of cold mirrors configured to direct light along a beam path; a cold or warm sample holder in the beam path; windows of sample holder (or whole sample holder) are transparent in a spectral region of interest, so they do not emit thermal radiation in the same spectral region of interest; a cold monochromator or other cold spectral device configured to direct a selected fraction of light onto a cold detector; a system of cold apertures and shields positioned along the beam path to prevent unwanted thermal radiation from arriving at the cold monochromator and/or the detector; a plurality of optical, IR and microwave filters positioned along the beam path and configured to adjust a spectral composition of light incident upon the sample under investigation and/or on the detector; a refrigerator configured to maintain the detector at a temperature below 1.0K; and an enclosure configured to: thermally insulate the light source, the plurality of mirrors, the sample holder, the cold monochromator and the refrigerator.

Preparation of 227Ac/223Ra by neutron irradiation of 226Ra

International Nuclear Information System (INIS)

Ekaterina Kukleva; Jan Kozempel; Martin Vlk; Petra Micolova; Dusan Vopalka

2015-01-01

Radium-223 is a prospective alpha-emitter for targeted radionuclide therapy. Although 223 Ra is formed naturally by the decay of 235 U, for practical reasons its preparation involves neutron irradiation of 226 Ra. The β - decay of the 227 Ra (T ½ = 43 min) produced via 226 Ra(n,γ) 227 Ra reaction leads to 227 Ac, a mother nuclide of 227 Th and subsequently 223 Ra. Radium target material is generally available in multigram quantities from historical stock. The main aim of this study was to experimentally as well as theoretically evaluate and verify the available literature data on production of 227 Ac/ 223 Ra. According to the data obtained from the γ-spectra, the approximate yield values were determined and effective cross section value for the 227 Ac production was calculated to 14 ± 4 b. (author)

Modeling Microalgal Biosediment Formation Based on Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Monitoring.

Science.gov (United States)

Ogburn, Zachary L; Vogt, Frank

2018-03-01

With increasing amounts of anthropogenic pollutants being released into ecosystems, it becomes ever more important to understand their fate and interactions with living organisms. Microalgae play an important ecological role as they are ubiquitous in marine environments and sequester inorganic pollutants which they transform into organic biomass. Of particular interest in this study is their role as a sink for atmospheric CO 2 , a greenhouse gas, and nitrate, one cause of harmful algal blooms. Novel chemometric hard-modeling methodologies have been developed for interpreting phytoplankton's chemical and physiological adaptations to changes in their growing environment. These methodologies will facilitate investigations of environmental impacts of anthropogenic pollutants on chemical and physiological properties of marine microalgae (here: Nannochloropsis oculata). It has been demonstrated that attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy can gain insights into both and this study only focuses on the latter. From time-series of spectra, the rate of microalgal biomass settling on top of a horizontal ATR element is derived which reflects several of phytoplankton's physiological parameters such as growth rate, cell concentrations, cell size, and buoyancy. In order to assess environmental impacts on such parameters, microalgae cultures were grown under 25 different chemical scenarios covering 200-600 ppm atmospheric CO 2 and 0.35-0.75 mM dissolved NO 3 - . After recording time-series of ATR FT-IR spectra, a multivariate curve resolution-alternating least squares (MCR-ALS) algorithm extracted spectroscopic and time profiles from each data set. From the time profiles, it was found that in the considered concentration ranges only NO 3 - has an impact on the cells' physiological properties. In particular, the cultures' growth rate has been influenced by the ambient chemical conditions. Thus, the presented spectroscopic�

Intracavity upconversion for IR absorption lidar: Comparison of linear and ring cavity designs

DEFF Research Database (Denmark)

Meng, Lichun; Høgstedt, Lasse; Tidemand-Lichtenberg, Peter

2017-01-01

Upconversion detection is a promising technology for measurement of IR signals in the 1.5 μm–2 μm region used for lidar remote sensing [1-2]. In comparison to conventional InGaAs detector, the upconversion detector can achieve IR detection with better signal-to-noise ratio (SNR), not only due...

Activity concentrations of /sup 226/Ra, /sup 228/Ra, /sup 210/Pb, /sup 40/K and /sup 7/Be and their temporal variations in surface air

Energy Technology Data Exchange (ETDEWEB)

Hoetzl, H.; Winkler, R.

1987-01-01

Activity concentrations of the long-lived natural radionuclides /sup 226/Ra, /sup 228/Ra, /sup 210/Pb, /sup 40/K and of /sup 7/Be in surface air were measured twice monthly at a semi-rural location 10 km north of Munich (FRG) for at least three years. For the time interval 1983-1985, all values were found to be distributed log-normally, with geometric means (in ..mu..Bq m-./sup 3/) of 1.2 for /sup 226/Ra, 0.5 for /sup 228/Ra, 580 for /sup 210/Pb, 12 for /sup 40/K and 3500 for /sup 7/Be. Reflecting their common origin, the activity concentrations of /sup 226/Ra and /sup 40/K are correlated with surface air dust concentrations (geometric mean 59 ..mu..g m/sup -3/). Seasonal variations of /sup 210/Pb and /sup 7/Be air activity concentrations are established for the time interval 1978-1985.. The contribution of local soil activity to the air activity concentrations of these radionuclides and of natural uranium is discussed. Resuspension factors are found to be of the order of 10/sup -9/ m/sup -1/.

Salicilo rūgšties įtaka kvapiojo baziliko ir vaistinio čiobrelio atsparumui sausrai atšilusio klimato sąlygomis

OpenAIRE

Vaitkevičiūtė, Birutė

2018-01-01

Pastaraisiais metais vis labiau ir labiau tampa aktualūs pasauliniai klimato pokyčiai. Taigi, svarbu nustatyti ir aptarti kaip šie veiksniai veikia vaistinių augalų fiziologinius, morfometrinius ir biocheminius rodiklius. Yra atlikta daug tyrimų kaip klimato kaita veikia kultūrinius augalus, maisto kokybę ir piktžoles. Tačiau beveik nėra tyrimų kaip salicilo rūgštimi (SR) veikti augalai reaguoja į atšilusio klimato ir sausros sąlygas. Augalai buvo auginami automatiškai kontroliuojamomis dabar...

224Ra and 226Ra experimentally induced dental changes in rats

International Nuclear Information System (INIS)

Reichart, P.A.; Althoff, J.; Eckhardt, W.; Rippel, W.

1979-01-01

Sprague-Dawley rats received intragastrically a single dose of 226 Ra or 224 Ra once weekly for 21 weeks. During this period the animals of both groups were thus exposed to comparable doses. After 12 weeks, a shortening of the maxillary incisors was observed, and this progressed during the course of the 55-week experiment. Radiologically, a loss of pulpal transparency and an apical irregular opacity in the maxillary incisors were demonstrable. Histologically, dysplastic changes of the maxillary incisors and multiple resorptions at the cemento-enamel junction of the molars were seen. The observed alterations were more pronounced in the 226 Ra group than in the 224 Ra treated group. The experimentally induced resorptions were comparable to those observed in patients who had incorporated 224 Ra or 226 Ra. Clinical, radiological, histological, γspecrometrical, and autoradiographical findings, as well as dose-estimations, are described. (author)

The UHV Experimental Chamber For Optical Measurements (Reflectivity and Absorption) and Angle Resolved Photoemission of the BEAR Beamline at ELETTRA

International Nuclear Information System (INIS)

Pasquali, L.; Nannarone, S.; De Luisa, A.

2004-01-01

The experimental station of the BEAR (Bending magnet for Emission, Absorption and Reflectivity) beamline at ELETTRA (Trieste, Italy) is an UHV chamber conceived to fully exploit the spectroscopic possibilities offered by the light spot produced by the beamline. Spectroscopies include reflectivity (θ-2θ and diffuse), optical absorption, fluorescence and angle resolved photoemission. The chamber can be rotated around the beam axis to select the s (TE) or p (TM) incidence conditions and/or the position of the ellipse of polarization with respect to the sample. Photon detectors (e.g. photodiodes) and electron detector (hemispherical analyzer - 1 deg. angular resolution, 20 meV energy resolution) cover about completely the full 2π solid angle above the sample surface in any light incidence condition

Developing Integral Review: IR Editors Reflect on Meta-theory, the Concept of “Integral,” Submission Acceptance Criteria, our Mission, and more.

Directory of Open Access Journals (Sweden)

Russ Volckmann

2007-12-01

Full Text Available Over the past three years our journey as editors of Integral Review has been full of rich learning. The processes of providing authors with feedback, going over reviews of articles as well as writing ourselves have all contributed to our growth. The primary forum for this learning has been the many conversations amongst us to deal with the various issues that arise in publishing IR. Our intention in this brief piece is to share some of our reflections on this learning journey with you. These will take the form of contributions/reflections from individual editors, allowing us to share with you the particular issues we feel of value in this process. By writing these short pieces, we aim to provide additional resources for understanding how IR works. While we have guidelines and criteria for submissions on our website, it seems that narrative voices from individuals may add some flesh to them. Relating how we perceive issues around writing for an “integral” journal offers a supplement for engaging these criteria, and will hopefully bring them to life. As well, we hope that our writing provides insights into how and what we think about issues relevant to IR’s mission. These pieces reflect the unique voices we have as editors of Integral Review, and demonstrate some of the thinking and passions behind this journal.

Absorption and reflectivity of the lithium niobate surface masked with a graphene layer

Directory of Open Access Journals (Sweden)

O. Salas

2017-01-01

Full Text Available We performed simulations of the interaction of a graphene layer with the surface of lithium niobate utilizing density functional theory and molecular dynamics at 300K and atmospheric pressure. We found that the graphene layer is physisorbed on the lithium niobate surface with an adsorption energy of -0.8205 eV/(carbon-atom. Subsequently, the energy band structure, the optical absorption and reflectivity of the new system were calculated. We found important changes in these physical properties with respect to the corresponding ones of a graphene layer and of a lithium niobate crystal.

Evaluation of V, Ir, Ru, V-Ir, V-Ru, and W-V as permanent chemical modifiers for the determination of cadmium, lead, and zinc in botanic and biological slurries by electrothermal atomic absorption spectrometry

International Nuclear Information System (INIS)

Acar, Orhan

2005-01-01

Permanent modifiers (V, Ir, Ru, V-Ir, V-Ru, and W-V) thermally coated on to platforms of pyrolytic graphite tubes were employed for the determination of Cd, Pb, and Zn in botanic and biological slurries by electrothermal atomic absorption spectrometry (ETAAS). Conventional Pd + Mg(NO 3 ) 2 modifier mixture was also used for the determination of analytes in slurries and digested samples. Optimum masses and mass ratios of permanent modifiers for Cd, Pb, and Zn in slurry sample solutions were investigated. The 280 μg of V, 280 μg of V + 200 μg of Ir, 280 μg of V + 200 μg of Ru or 240 μg of W + 280 μg of V in 0.2% (v/v) Triton X-100 plus 0.5% (v/v) HNO 3 mixture was found as efficient as 5 μg of Pd + 3 μg of Mg(NO 3 ) 2 modifier mixture for obtaining thermal stabilization, and for obtaining best recoveries. Optimization conditions of analytes, such as pyrolysis and atomization temperature, characteristic masses and detection limits, and atomization and background peak profiles were studied with permanent and 5 μg of Pd + 3 μg of Mg(NO 3 ) 2 conventional modifiers and compared with each other. The permanent V-Ir, V-Ru, and W-V modifiers remained stable for approximately 250-300 firings when 20 μl of slurries and digested samples were delivered into the atomizer. In addition, the mixed permanent modifiers increase the tube lifetime by 50-95% when compared with untreated platforms. The characteristic masses and detection limits of analytes (dilution factor of 125 ml g -1 ) obtained with V-Ir based on integrated absorbance as example for 0.8% (m/v) slurries were 1.0 pg and 3 ng g -1 for Cd, 18 pg and 17 ng g -1 for Pb, and 0.7 pg and 4 ng g -1 for Zn, respectively. The results of analytes obtained by employing V-Ir, V-Ru, and W-V permanent modifier mixtures in botanic and biological certified and standard reference materials were in agreement with the certified values of reference materials

Monitoring combat wound healing by IR hyperspectral imaging

Science.gov (United States)

Howle, Chris R.; Spear, Abigail M.; Gazi, Ehsan; Crane, Nicole J.

2016-03-01

In recent conflicts, battlefield injuries consist largely of extensive soft injuries from blasts and high energy projectiles, including gunshot wounds. Repair of these large, traumatic wounds requires aggressive surgical treatment, including multiple surgical debridements to remove devitalised tissue and to reduce bacterial load. Identifying those patients with wound complications, such as infection and impaired healing, could greatly assist health care teams in providing the most appropriate and personalised care for combat casualties. Candidate technologies to enable this benefit include the fusion of imaging and optical spectroscopy to enable rapid identification of key markers. Hence, a novel system based on IR negative contrast imaging (NCI) is presented that employs an optical parametric oscillator (OPO) source comprising a periodically-poled LiNbO3 (PPLN) crystal. The crystal operates in the shortwave and midwave IR spectral regions (ca. 1.5 - 1.9 μm and 2.4 - 3.8 μm, respectively). Wavelength tuning is achieved by translating the crystal within the pump beam. System size and complexity are minimised by the use of single element detectors and the intracavity OPO design. Images are composed by raster scanning the monochromatic beam over the scene of interest; the reflection and/or absorption of the incident radiation by target materials and their surrounding environment provide a method for spatial location. Initial results using the NCI system to characterise wound biopsies are presented here.

Quantum state-resolved gas/surface reaction dynamics probed by reflection absorption infrared spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Chen Li [Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Goettingen (Germany); Ueta, Hirokazu; Beck, Rainer D. [Laboratoire de Chimie Physique Moleculaire, Ecole Polytechnique Federale de Lausanne (Switzerland); Bisson, Regis [Aix-Marseille Universite, PIIM, CNRS, UMR 7345, 13397 Marseille (France)

2013-05-15

We report the design and characterization of a new molecular-beam/surface-science apparatus for quantum state-resolved studies of gas/surface reaction dynamics combining optical state-specific reactant preparation in a molecular beam by rapid adiabatic passage with detection of surface-bound reaction products by reflection absorption infrared spectroscopy (RAIRS). RAIRS is a non-invasive infrared spectroscopic detection technique that enables online monitoring of the buildup of reaction products on the target surface during reactant deposition by a molecular beam. The product uptake rate obtained by calibrated RAIRS detection yields the coverage dependent state-resolved reaction probability S({theta}). Furthermore, the infrared absorption spectra of the adsorbed products obtained by the RAIRS technique provide structural information, which help to identify nascent reaction products, investigate reaction pathways, and determine branching ratios for different pathways of a chemisorption reaction. Measurements of the dissociative chemisorption of methane on Pt(111) with this new apparatus are presented to illustrate the utility of RAIRS detection for highly detailed studies of chemical reactions at the gas/surface interface.

Infrared polarimetry of the reflection nebula near L 1551 IRS 5

Energy Technology Data Exchange (ETDEWEB)

Nagata, Tetsuya; Yamashita, Takuya; Sato, Shuji; Suzuki, Hiro; Hough, J H; Garden, R; Gatley, I

1986-11-01

The K-band polarization has been measured in the region extending 30 arcsec to the SW of L 1551 IRS5. The degree of polarization is exceptionally high, reaching approx. 67 per cent. The large polarizations and the azimuthal pattern of the position angles are attributed to scattering of infrared radiation from IRS5 by dust grains. The infrared brightness distribution resembles that of the optical nebulosity. It is proposed that infrared scattering occurs at the 'walls' of a cavity formed by the interaction of stellar winds with the ambient cloud.

/sup 226/Ra in the western Indian Ocean

Energy Technology Data Exchange (ETDEWEB)

Chung, Y.

1987-09-01

/sup 226/Ra profiles have been measured in the western Indian Ocean as part of the 1977-78 Indian Ocean GEOSECS program. These profiles show a general increase in deep and bottom water Ra concentration from the Circumpolar region to the Arabian Sea. A deep Ra maximum which originates in the Arabian Sea and in the Somali basin at about 3000 m depth spreads southward into the Mascarene basin and remains discernible in the Madagascar and Crozet basins. In the western Indian Ocean, the cold Antarctic Bottom Water spreads northward under the possibly southward-flowing deep water, forming a clear benthic front along the Crozet basin across the Southwest Indian Ridge into the Madagascar and Mascarene basins. The Antarctic Bottom Water continues to spread farther north to the Somali basin through the Amirante Passage at 10/sup 0/S as a western boundary current. The benthic front and other characteristic features in the western Indian Ocean are quite similar to those observed in the western Pacific where the benthic front as a distinctive feature was first described by Craig et al. Across the Mid-Indian Ridge toward the Ceylon abyssal plain near the triple junction, Ra profiles display a layered structure, reflecting the topographic effect of the mid-ocean ridge system on the mixing and circulation of the deep and bottom waters. Both Ra and Si show a deep maximum north of the Madagascar Basin. Linear relationships between these two elements are observed in the deep and bottom water with slopes increasing northward. This suggests a preferential input of Ra over Si from the bottom sediments of the Arabian Sea and also from the flank sediments of the Somali basin.

Synthesis and selective IR absorption properties of iminodiacetic-acid intercalated MgAl-layered double hydroxide

International Nuclear Information System (INIS)

Wang Lijing; Xu Xiangyu; Evans, David G.; Duan Xue; Li Dianqing

2010-01-01

An MgAl-NO 3 -layered double hydroxide (LDH) precursor has been prepared by a method involving separate nucleation and aging steps (SNAS). Reaction with iminodiacetic acid (IDA) under weakly acidic conditions led to the replacement of the interlayer nitrate anions by iminodiacetic acid anions. The product was characterized by XRD, FT-IR, TG-DTA, ICP, elemental analysis and SEM. The results show that the original interlayer nitrate anions of LDHs precursor were replaced by iminodiacetic acid anions and that the resulting intercalation product MgAl-IDA-LDH has an ordered crystalline structure. MgAl-IDA-LDH was mixed with low density polyethylene (LDPE) using a masterbatch method. LDPE films filled with MgAl-IDA-LDH showed a higher mid to far infrared absorption than films filled with MgAl-CO 3 -LDH in the 7-25 μm range, particularly in the key 9-11 μm range required for application in agricultural plastic films. - Graphical abstract: Intercalation of iminodiacetic acid (IDA) anions in a MgAl-NO 3 -layered double hydroxide host leads to an enhancement of its infrared absorbing ability for application in agricultural plastic films.

Critical Reflectance Derived from MODIS: Application for the Retrieval of Aerosol Absorption over Desert Regions

Science.gov (United States)

Wells, Kelley C.; Martins, J. Vanderlei; Remer, Lorraine A.; Kreidenweis, Sonia M.; Stephens, Graeme L.

2012-01-01

Aerosols are tiny suspended particles in the atmosphere that scatter and absorb sunlight. Smoke particles are aerosols, as are sea salt, particulate pollution and airborne dust. When you look down at the earth from space sometimes you can see vast palls of whitish smoke or brownish dust being transported by winds. The reason that you can see these aerosols is because they are reflecting incoming sunlight back to the view in space. The reason for the difference in color between the different types of aerosol is that the particles arc also absorbing sunlight at different wavelengths. Dust appears brownish or reddish because it absorbs light in the blue wavelengths and scatters more reddish light to space, Knowing how much light is scattered versus how much is absorbed, and knowin that as a function of wavelength is essential to being able to quantify the role aerosols play in the energy balance of the earth and in climate change. It is not easy measuring the absorption properties of aerosols when they are suspended in the atmosphere. People have been doing this one substance at a time in the laboratory, but substances mix when they are in the atmosphere and the net absorption effect of all the particles in a column of air is a goal of remote sensing that has not yet been completely successful. In this paper we use a technique based on observing the point at which aerosols change from brightening the surface beneath to darkening it. If aerosols brighten a surface. they must scatter more light to space. If they darken the surface. they must be absorbing more. That cross over point is called the critical reflectance and in this paper we show that critical reflectance is a monotonic function of the intrinsic absorption properties of the particles. This parameter we call the single scattering albedo. We apply the technique to MODIS imagery over the Sahara and Sahel regions to retrieve the single scattering albedo in seven wavelengths, compare these retrievals to ground

Research nuclear reactor RA - Annual Report 1975. Operation and maintenance; Istrazivacki nuklearni reaktor RA - Izvestaj za 1975. godinu - Pogon i odrzavanje

Energy Technology Data Exchange (ETDEWEB)

Martinc, R [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1976-01-15

The plan for 1975 was successfully fulfilled. This is reflected in research related to improvement of operating properties of the RA reactor, mostly due to the effort of the RA staff employed in operation and maintenance of the reactor. Fuel saving achieved by this activity amounted to about 38% (80% enriched fuel). Preliminary work is done, concerned with new reactor core with highly enriched fuel. This is a significant saving as well. New fuel elements have arrived at the end of this year. It is going to enable increase of neutron flux by 50% without changing the nominal operating power. The possibility of further improvement of the reactor are analyzed, to enable material testing and production of radioactive sources. Mid term plan for reactor operation was made according to this analysis. It is planned to further increase the neutron flux in isolated smaller zones, and building new experimental loops with cooling and fast neutron converters. Much was done to increase the safety level of reactor operation and preparing the safety report. [Serbo-Croat] Izvrsenje zadataka u 1975. godini bilo je uspesno. To se ogleda u povecanju istrazivackog rada vezanog za poboljsanje eksploatacionih karakteristika reaktora RA, pretezno koriscenjem sopstvenog kadra angazovanog u pogonu i odrzavanju reaktora. Ovim radom postignuta je usteda goriva od oko 38% (80% obogaceno gorivo). Izvrseni su preliminarni radovi na prevodjenju reaktora RA na novo gorivo, sto je takodje velika usteda. Novo gorivo je stiglo krajem godine i ono ce obezbediti porast neutronskog fluksa od 50%, bez promene nominalne snage reaktora. Izvrsena je analiza mogucnosti daljeg usavrsavanja reaktora za potrebe ispitivanja materijala kao i proizvodnju radioaktivnih izvora. Na osnovu ove analize nacinjen je srednjorocni program rada reaktora RA sa tezistem na daljem povecanju fluksa u izdvojenim manjim zonama i ugradnju 'hladjenih petlji' i brzih konvertora. Mnogo je ucinjeno na povecanju stepena sigurnosti

Validation of {sup 226}Ra, {sup 228}Ra and {sup 210}Pb measurements in soil and sediment samples through high resolution gamma ray spectrometry

Energy Technology Data Exchange (ETDEWEB)

Dias, Danila Carrijo da Silva; Silva, Nivaldo Carlos da; Bonifacio, Rodrigo Leandro; Guerrero, Eder Tadeu Zenun [Comissao Nacional de Energia Nuclear (LAPOC/CNEN-MG), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas

2013-07-01

Radionuclides found in ore extraction waste materials are a great source of concern regarding public health and environmental safety. One technique to determine the concentration of substances is high resolution gamma ray spectrometry using HPGe. Validating a measurement technique is essential to warrant high levels of quality to any scientific work. The Laboratory of Pocos de Caldas of the Brazilian Commission for Nuclear Energy partakes into a Quality Management System project, seeking Accreditation under ISO/IEC 17025 through the validation of techniques of chemical and radiometric analysis of environmental samples from water, soil and sediment. The focus of the Radon Laboratory at LAPOC is validation of Ra-226, Ra-228 and Pb-210 concentration determinations in soil and sediment through a gamma spectrometer system. The stages of this validation process included sample reception and preparation, detector calibration and sample analyses. Dried samples were sealed in metallic containers and analyzed after radioactive equilibrium between Ra-226 and daughters Pb-214 and Bi-214. Gamma spectrometry was performed using CANBERRA HPGe detector and gamma spectrum software Genie 2000. The photo peaks used for Ra-226 determination were 609 keV and 1020 keV of Bi-214 and 351 keV of Pb-214. For the Ra-228 determination a photopeak of 911 keV was used from its short half-life daughter Ac-228 (T1/2 = 6.12 h). For Pb-210, the photopeak of 46.5 keV was used, which, due to the low energy, self-absorption correction was needed. Parameters such as precision, bias/accuracy, linearity, detection limit and uncertainty were evaluated for that purpose. The results have pointed to satisfying results. (author)

Measurements of neutron flux in the RA reactor; Merenje karakteristika neutronskog fluksa u reaktoru RA

Energy Technology Data Exchange (ETDEWEB)

Raisic, N [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1961-12-15

This report includes the following separate parts: Thermal neutron flux in the experimental channels od RA reactor; Epithermal neutron flux in the experimental channels od RA reactor; Fast neutron flux in the experimental channels od RA reactor; Thermal neutron flux in the thermal column and biological experimental channel; Neutronic measurements in the RA reactor cell; Temperature reactivity coefficient of the RA reactor; design of the device for measuring the activity of wire. [Serbo-Croat] Ovaj izvestaj sadrzi sledece referate: Fluks termalnih neutrona u eksperimentalnim kanalima reaktora RA; Fluks epitermalnih neutrona u eksperimentalnim kanalima reaktora RA; Fluks brzih neutrona u eksperimentalnim kanalima reaktora RA; Fluks termalnih neurona u termalnoj koloni i bioloskom eksperimentalnom kanalu; Neutronska merenja u elementarnoj celiji reaktora RA; Temperaturni koeficijent reaktivnosti reaktora RA; Projekat uredjaja za merenje radioaktivnosti zice.

Determination of the Ability to Measure Traces of Water in Dehydrated Residues of Waste Water by IR Diffuse Reflectance Spectra

Science.gov (United States)

Pratsenka, S. V.; Voropai, E. S.; Belkin, V. G.

2018-01-01

Rapid measurement of the moisture content of dehydrated residues is a critical problem, the solution of which will increase the efficiency of treatment facilities and optimize the process of applying flocculants. The ability to determine the moisture content of dehydrated residues using a meter operating on the IR reflectance principle was confirmed experimentally. The most suitable interference filters were selected based on an analysis of the obtained diffuse reflectance spectrum of the dehydrated residue in the range 1.0-2.7 μm. Calibration curves were constructed and compared for each filter set. A measuring filter with a transmittance maximum at 1.19 μm and a reference filter with a maximum at 1.3 μm gave the best agreement with the laboratory measurements.

Preliminary study of corrosion mechanisms of actinides alloys: calibration of FT-IR spectroscopy

International Nuclear Information System (INIS)

Magnien, Veronique; Cadignan, Marx; Faivret, Olivier; Rosa, Gaelle

2008-01-01

In situ analyzes of gaseous atmospheres could be performed by FT-IR spectroscopy in order to study the corrosion reactions of actinides. Nevertheless experimental conditions and the nature of studied species have a strong effect on IR absorption laws. Thus a prior calibration of our set-up is required to obtain an accurate estimation of gas concentration. For this purpose, the behavior of several air pure gases has been investigated according to their concentration from IR spectra. Reproducible results revealed subsequent increases of the most significant peak areas with gas pressure and small deviations from Beer Lambert's law. This preliminary work allowed to determine precise absorption laws for each studied pure gas in our in situ experimental conditions. Besides our FT-IR set-up was well suitable to quantitative analysis of gaseous atmosphere during corrosion reactions. Finally the effect of foreign gas will be investigated through more complex air mixtures to obtain a complete calibration network. (authors)

Theory of strong-field attosecond transient absorption

International Nuclear Information System (INIS)

Wu, Mengxi; Chen, Shaohao; Camp, Seth; Schafer, Kenneth J; Gaarde, Mette B

2016-01-01

Attosecond transient absorption is one of the promising new techniques being developed to exploit the availability of sub-femtosecond extreme ultraviolet (XUV) pulses to study the dynamics of the electron on its natural time scale. The temporal resolution in a transient absorption setup comes from the control of the relative delay and coherence between pump and probe pulses, while the spectral resolution comes from the characteristic width of the features that are being probed. In this review we focus on transient absorption scenarios where an attosecond pulse of XUV radiation creates a broadband excitation that is subsequently probed by a few cycle infrared (IR) laser. Because the attosecond XUV pulses are locked to the IR field cycle, the exchange of energy in the laser–matter interaction can be studied with unprecedented precision. We focus on the transient absorption by helium atoms of XUV radiation around the first ionization threshold, where we can simultaneoulsy solve the time-dependent Schrödinger equation for the single atom response and the Maxwell wave equation for the collective response of the nonlinear medium. We use a time-domain method that allows us to treat on an equal footing all the different linear and nonlinear processes by which the medium can exchange energy with the fields. We present several simple models, based on a few-level system interacting with a strong IR field, to explain many of the novel features found in attosecond transient absorption spectrograms. These include the presence of light-induced states, which demonstrate the ability to probe the dressed states of the atom. We also present a time-domain interpretation of the resonant pulse propagation features that appear in absorption spectra in dense, macroscopic media. We close by reviewing several recent experimental results that can be explained in terms of the models we discuss. Our aim is to present a road map for understanding future attosecond transient absorption

Spectroelectrochemical study of polyphenylene by in situ external reflection FT-IR spectroscopy. Pt. 1

International Nuclear Information System (INIS)

Kvarnstroem, C.; Ivaska, A.

1994-01-01

In situ spectroelectrochemical measurements with external reflection FT-IR are performed at different stages of polymerization of 0.05, 0.1 and 0.8 M biphenyl in 0.1 M TBABF 4 in acetonitrile. The biphenyl concentration is not found to have any effect on the structure of the polymer formed. Formation of oligomers and the ratio of ortho/para-substituted polymer chains during film growth are studied. The first coupling of dimers to oligomers is found to take place in the vicinity of the electrode surface and at a later stage of polymerization the oligomers start to form polymer film on the electrode. A mixed para and ortho coupling resulting in crosslinking between chains is observed already at the early stage of polymerization. However, when a lower current density is used a more ordered polymer structure is obtained. A breakdown of the polymer film due to overoxidation can be seen when the potential is increased to 2.0 V. (orig.)

Kinetics of physical adsorption of ethane on Ir(110)-(1×2): Molecular beam reflectivity measurements and Monte Carlo simulations

OpenAIRE

Kang, H. C.; Mullins, C. B.; Weinberg, W. H.

1990-01-01

Experimental results, obtained using a reflectivity method, for the probability of physical adsorption of ethane on the Ir(110)-(1×2) surface are presented. We analyze these results using Monte Carlo simulations and show that physical adsorption can occur either directly or through a precursor state in which an ethane molecule is trapped in a second layer above a first layer of physically adsorbed ethane. From the Monte Carlo simulations, we are able to establish that the energy barrier for d...

RA Research nuclear reactor Part 1, RA Reactor operation and maintenance in 1987; Istrazivacki nuklearni reaktor RA Deo 1 - Pogon i odrzavanje nuklearnog reaktora RA u 1987. godini

Energy Technology Data Exchange (ETDEWEB)

Sotic, O; Martinc, R; Cupac, S; Sulem, B; Badrljica, R; Majstorovic, D; Sanovic, V [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1987-12-15

RA research reacto was not operated due to the prohibition issued in 1984 by the Government of Serbia. Three major tasks were finished in order to fulfill the licensing regulations about safety of nuclear facilities which is the condition for obtaining permanent operation licence. These projects involved construction of the emergency cooling system, reconstruction of the existing special ventilation system, and renewal of the system for electric power supply of the reactor systems. Renewal of the RA reactor instrumentation system was initiated. Design project was done by the Russian Atomenergoeksport, and is foreseen to be completed by the end of 1988. The RA reactor safety report was finished in 1987. This annual report includes 8 annexes concerning reactor operation, activities of services and financial issues, and three special annexes: report on testing the emergency cooling system, report on renewal of the RA reactor and design specifications for reactor renewal and reconstruction. [Serbo-Croat] Reaktor RA nije radio usled zabrane Izvsnog veca Skupstine Srbije od 27. avgusta 1984. U cilju povecanja pouzdanosti rada reaktora a da bi se udovoljilo zakonskim propisima sto je uslov za dobijanje stalne dozvole za rad realizovana su tri velika zahvata na reaktoru RA. Ovi zahvati obuhvatili su izgradnju sistema za hladjenje jezgra reaktora u slucaju nuzde, rekonstukciju postojeceg sistema specijalne ventilacije i rekonstrukciju sistema napajanja elektricnom energijom neophodnih potrosaca reaktora RA. Zapoceti su radovi na modernizaciji intrumentacije reaktora RA, projekat je izradjen u sovjetskoj organizaciji Atomenergoeksport, a trebalo bi da se realizuje do kraja 1989. godine. U cilju povecanja prostora za skladistenje ozracenog nuklearnog goriva i njegovog efikasnijeg koriscenja, izradjen je su projekti za rekonstrukciju postojecih uredjaja za rukovanje gorivom, povecanje smestajnog kapaciteta i preciscavanje vode u bazenima za odlezavanje. Realizaija ovih

Fine structures in 14C emission of 223Ra and 224Ra

International Nuclear Information System (INIS)

Hourani, E.; Rosier, L.; Berrier-Ronsin, G.; Elayi, A.; Mueller, A.C.; Rappenecker, G.; Rotbard, G.; Renou, G.; Liebe, A.; Stab, L.

1991-01-01

The measurement of the energy spectrum of 14 C nuclei emitted in the spontaneous radioactivity from 223 Ra and 224 Ra has been carried out, using thin and intense sources (480 MBq for 223 Ra and 3550 MBq for 224 Ra). The sources were obtained by implanting mass-separated beams from ISOLDE (CERN) into Al and vitreous C catchers. The measurement was performed with the supraconducting solenoidal spectrometer SOLENO installed at Orsay. The discovery, of a fine structure in the energy spectrum of 14 C emission from 223 Ra, which is analogous to the one known for α emission, is confirmed. Only 13% of the branching ratio in 14 C decay leads to the ground state of the residual nucleus, while 8l% to the first excited state. For 14 C emission of 224 Ra, a lower limit of 2 for the hindrance factor has been measured for the transition to the first excited state in the residual nucleus. Also, a precise identification in Z with a E·ΔE telescope has been performed for the radiation from the 223 Ra source. (author) 22 refs., 11 figs., 1 tab

RA Research reactor, Annual report 1988; Istrazivacki nuklearni reaktor RA - Izvestaj za 1988. godinu

Energy Technology Data Exchange (ETDEWEB)

Sotic, O [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1988-12-15

Annual report concerning the project 'RA research nuclear reactor' for 1989, financed by the Serbian ministry of science is divided into two parts. First part is concerned with RA reactor operation and maintenance, which is the task of the Division for reactor engineering of the Institute for multidisciplinary studies and RA reactor engineering. Second part deals with radiation protection activities at the RA reactor which is the responsibility of the Institute for radiation protection. Scientific council of the Institute for multidisciplinary studies and RA reactor engineering has stated that this report describes adequately the activity and tasks fulfilled at the RA reactor in 1989. The scope and the quality of the work done were considered successful both concerning the maintenance and reconstruction, as well as radiation protection activities. [Serbo-Croat] Godisnji izvestaj po projektu 'Istrazivacki nuklearni reaktor RA' za 1989. godinu, koji finansira republicka zajednica za nauku SR Srbije po ugovoru br. 3705/1 sastoji se iz dva dela. Prvi deo obuhvata pogon i odrzavanje nuklearnog reaktora RA, sto predstavlja obavezu Odeljenja za reaktorski inzenjering u sastavu OOUR Instituta za multidisciplinarna istrazivanja i inzenjering RA. Drugi deo obuhvata poslove zastite od zracenja na reaktoru RA, sto predstavlja obavezu OOUR Instituta za zastitu od zracenja 'Zastita'. Naucno vece Instituta za multidisciplinarna istrazivanja i inzenjering RA ocenilo je da sadrzina ovog izvestaja odgovara izvrsenim poslovima na reaktoru RA u 1989. godini. Pozitivno se ocenjuje obim i kvalitet izvrsenih radova kako u pogledu odrzavanja i rekonstrukcije reaktora, tako i u pogledu poslova zastite od zracenja izvrsenih kod njega.

Visualizing Infrared (IR) Spectroscopy with Computer Animation

Science.gov (United States)

Abrams, Charles B.; Fine, Leonard W.

1996-01-01

IR Tutor, an interactive, animated infrared (IR) spectroscopy tutorial has been developed for Macintosh and IBM-compatible computers. Using unique color animation, complicated vibrational modes can be introduced to beginning students. Rules governing the appearance of IR absorption bands become obvious because the vibrational modes can be visualized. Each peak in the IR spectrum is highlighted, and the animation of the corresponding normal mode can be shown. Students can study each spectrum stepwise, or click on any individual peak to see its assignment. Important regions of each spectrum can be expanded and spectra can be overlaid for comparison. An introduction to the theory of IR spectroscopy is included, making the program a complete instructional package. Our own success in using this software for teaching and research in both academic and industrial environments will be described. IR Tutor consists of three sections: (1) The 'Introduction' is a review of basic principles of spectroscopy. (2) 'Theory' begins with the classical model of a simple diatomic molecule and is expanded to include larger molecules by introducing normal modes and group frequencies. (3) 'Interpretation' is the heart of the tutorial. Thirteen IR spectra are analyzed in detail, covering the most important functional groups. This section features color animation of each normal mode, full interactivity, overlay of related spectra, and expansion of important regions. This section can also be used as a reference.

Absorption and removal of Ra-226, Pb-210 and Po-210 by humans and the resulting radiation exposure

International Nuclear Information System (INIS)

Gloebel, B.; Berlich, J.; Andres, C.

1985-01-01

In over 400 samples (food, water, air, stools and urine), the concentration of Ra-226, Pb-210 and Po-210 was measured. The daily intake for the three nuclides is: Ra-226: 30 mBq; Pb-210: 150 mBq; Po-210: 150 mBq. The table shows intake of individual food and drinking items as well as air. In all but the kidney samples, Pb and Po were present in radioactive equilibrium. The contribution of each radionuclide to radiation exposure is indicated. (orig./HP) [de

Final Technical Report - Polymeric Multilayer Infrared Reflecting Mirrors

Energy Technology Data Exchange (ETDEWEB)

Reed, John [3M Company, St. Paul, MN (United States)

2016-09-16

The goal of this project was to develop a clear, polymeric, multilayer film with an expanded infrared (IR) reflection band which would allow improved rejection of incident IR energy. The IR reflection band is covering the region from about 850 nm to 1830 nm. This film is essentially clear and colorless in the visible portion of the electromagnetic spectra (visible light transmission of about 89%) while reflecting 90-95% of the IR energy over the portion of the spectra indicated above. This film has a nominal thickness of 3 mils, is polymeric in nature (contains no metals, metal oxides, or other material types) and is essentially clear in appearance This film can then be used as a component of other products such as a solar window film, an IR reflecting interlayer for laminated glass, a heat rejecting skylight film, a base film for daylight redirecting products, a greenhouse film, and many more applications. One of the main strengths of this product is that because it is a standalone IR rejecting film, it can be incorporated and retrofitted into many applications that desire or require the transmission of visible light, but want to block other portions of the solar spectra, especially the IR portion. Many of the applications exist in the window glazing product area where this film can provide for substantial energy improvements in applications where visible light is desired.

Effects of gastric pH on oral drug absorption: In vitro assessment using a dissolution/permeation system reflecting the gastric dissolution process.

Science.gov (United States)

Kataoka, Makoto; Fukahori, Miho; Ikemura, Atsumi; Kubota, Ayaka; Higashino, Haruki; Sakuma, Shinji; Yamashita, Shinji

2016-04-01

The aim of the present study was to evaluate the effects of gastric pH on the oral absorption of poorly water-soluble drugs using an in vitro system. A dissolution/permeation system (D/P system) equipped with a Caco-2 cell monolayer was used as the in vitro system to evaluate oral drug absorption, while a small vessel filled with simulated gastric fluid (SGF) was used to reflect the gastric dissolution phase. After applying drugs in their solid forms to SGF, SGF solution containing a 1/100 clinical dose of each drug was mixed with the apical solution of the D/P system, which was changed to fasted state-simulated intestinal fluid. Dissolved and permeated amounts on applied amount of drugs were then monitored for 2h. Similar experiments were performed using the same drugs, but without the gastric phase. Oral absorption with or without the gastric phase was predicted in humans based on the amount of the drug that permeated in the D/P system, assuming that the system without the gastric phase reflected human absorption with an elevated gastric pH. The dissolved amounts of basic drugs with poor water solubility, namely albendazole, dipyridamole, and ketoconazole, in the apical solution and their permeation across a Caco-2 cell monolayer were significantly enhanced when the gastric dissolution process was reflected due to the physicochemical properties of basic drugs. These amounts resulted in the prediction of higher oral absorption with normal gastric pH than with high gastric pH. On the other hand, when diclofenac sodium, the salt form of an acidic drug, was applied to the D/P system with the gastric phase, its dissolved and permeated amounts were significantly lower than those without the gastric phase. However, the oral absorption of diclofenac was predicted to be complete (96-98%) irrespective of gastric pH because the permeated amounts of diclofenac under both conditions were sufficiently high to achieve complete absorption. These estimations of the effects of

Perforated SiN membrane resonators for nanomechanical IR spectroscopy poster

DEFF Research Database (Denmark)

Kurek, Maksymilian; Carnoy, Matthias; Boisen, Anja

Constant progress in micro- and nanofabrication provides a great opportunity in development of micro- and nanomechanical resonatorsthat can be used for sensing purposes. These sensors usually consist of singly-clamped cantilever beams, doubly-clamped bridges ormembranes that exhibit resonant......, lateral dimension of1×1 mm2 and 2 µm perforation grid pitch were used instead of strings which makes the IR beam alignment significantly simpler whilemaintaining similar sampling efficiency and photothermal IR absorption sensitivity....

Observation of the long-lived triplet excited state of perylenebisimide (PBI) in C^N cyclometalated Ir(III) complexes and application in photocatalytic oxidation.

Science.gov (United States)

Sun, Jifu; Zhong, Fangfang; Zhao, Jianzhang

2013-07-14

Perylenebisimide (PBI) was used to prepare C^N cyclometalated Ir(III) complexes that show strong absorption of visible light and it is the first time the long-lived triplet excited state of PBI chromophore was observed in a transition metal complex (τT = 22.3 μs). Previously, the lifetime of the triplet state of PBI in transition metal complexes was usually shorter than 1.0 μs. Long-lived triplet excited states are useful for applications in photocatalysis or other photophysical processes concerning triplet-triplet-energy-transfer. PBI and amino-PBI were used for preparation of cyclometalated Ir(III) complexes (Ir-2 and Ir-3), in which the PBI chromophore was connected to the coordination center via C≡C π-conjugation bond. The new complexes show strong absorption in visible region (ε = 34,200 M(-1) cm(-1) at 541 nm for Ir-2, and ε = 19,000 at 669 nm for Ir-3), compared to the model complex Ir(ppy)(bpy)[PF6] Ir-1 (ε PBI-localized long-lived (3)IL states were populated for Ir-2 and Ir-3 upon photoexcitation. The complexes were used as triplet photosensitizers for (1)O2-mediated photooxidation of 1,5-dihydronaphthalene to produce juglone, an important intermediate for preparation of anti-cancer compounds. (1)O2 quantum yields (Φ(Δ)) up to 91% were observed for the new Ir(III) complexes and the overall photosensitizing ability is much higher than the conventional Ir(III) complex Ir-1, which shows the typical weak visible light absorption in visible region. Our results are useful for preparation of transition metal complexes that show strong absorption of visible light and long-lived triplet excited state and for the application of these complexes in photocatalysis.

Alpha-particle doses to human organs and tissues from internally-deposited 226Ra and 228Ra

International Nuclear Information System (INIS)

Keane, A.T.; Schlenker, R.A.

1981-01-01

Estimation of radiation doses to the soft tissues from internally-deposited 226 Ra and 228 Ra is relevant to an investigation of soft-tissue malignancies in radium-exposed persons being conducted at the Center for Human Radiobiology. Alpha-particle doses in a 50-year period following a single injection of 226 Ra or 228 Ra are presented for 31 soft tissues and organs of the adult human. The dose estimates were derived from the ICRP alkaline earth model fitted to data on retention of 226 Ra in soft tissues and bone, combined with reported ratios of 226 Ra to Ca in soft tissue and bone at natural levels and the distribution of Ca in the tissues of Reference Man (ICRP23). The median of the 31 organ and tissue doses from the α-particles of 226 Ra itself is 0.08 rad per injected μCi. An additional average dose of 0.01 rad per μCi 226 Ra daughter products produced in soft tissue or transferred from bone to soft tissue. Soft-tissue doses from α-particles of the 228 Ra decay series are about six times those from 226 Ra α-particles for equal injected activities of 228 Ra and 226 Ra, with the assumption that 228 Ra daughter products do not transfer from the organ in which they are produced. The 50-year dose to the red marrow of bone from α-particles originating in bone is 0.55 rad per μCi 226 Ra injected and 1.0 rad per μCi 228 Ra injected. For ingestion by dial painters of luminous compound containg 226 Ra or 228 Ra with a daughter-to-parent activity ratio of 0.5, the dose to the mucosal alyer of the lower large intestine from α-particles originating in the gut contents is about 0.1 rad per μCi systemic intake of 226 Ra or 228 Ra

Techniques for precise mapping of 226Ra and 228Ra in the ocean

International Nuclear Information System (INIS)

Moore, W.S.; Key, R.M.; Sarmiento, J.L.

1985-01-01

Improvements in the analyses of 226 Ra and 228 Ra in seawater made possible by better extraction and processing techniques reduce significantly the errors associated with these measurements. These improvements and the extensive sampling for Ra isotopes conducted on the TTO North Atlantic Study should enable us to use the distribution of 228 Ra to study mixing processes on a 3-15 year time scale in both the upper and deep North Atlantic. The 228 Ra profiles already analyzed show a closer resemblance to GEOSECS tritium data than to TTO tritium data in the upper ocean. This is because the transient tracer tritium was responding on a 10-year time scale during GEOSECS and a 20-year time scale during TTO. The steady state tracer 228 Ra should always respond on a time scale of 8 years. Thus the 228 Ra data obtained on TTO should provide a means to extend the features of the GEOSECS tritium field to the regions of the TTO study. The 226 Ra data are of high enough quality to identify features associated with different water masses. Changes in the positions of the deep-water masses since the GEOSECS cruise are revealed by the 226 Radata

Thermoluminescence, infrared reflectivity and electron paramagnetic resonance properties of hemimorphite

Energy Technology Data Exchange (ETDEWEB)

Gallegos, E.A. [Institute of Physics, University of Sao Paulo, Rua do Matao, Travessa R, 187, CEP 05508-900, Sao Paulo, SP (Brazil); Cano, N.F. [Institute of Physics, University of Sao Paulo, Rua do Matao, Travessa R, 187, CEP 05508-900, Sao Paulo, SP (Brazil)], E-mail: nilocano@dfn.if.usp.br; Watanabe, S.; Chubaci, J.F.D. [Institute of Physics, University of Sao Paulo, Rua do Matao, Travessa R, 187, CEP 05508-900, Sao Paulo, SP (Brazil)

2009-01-15

Silicate mineral hemimorphite has been investigated concerning its TL, IR and EPR properties. A broad TL peak around 180 deg. C and a weaker and narrower peak around 360 deg. C were found in a sample annealed at 600 deg. C for 1 h and then irradiated. The deconvolution using the CGCD method revealed peaks around 132, 169, 222 and 367 deg. C. The reflectivity measurements showed several bands in the NIR region due to H{sub 2}O, OH and Al-OH complexes. No band was observed in the visible region. The thermal treatments were carried out from {approx}110 to 940 deg. C and dehydration was observed, first causing a diminishing optical absorption in general and the disappearance of water and hydroxyl absorption bands. The EPR spectrum of natural hemimorphite, presented Cu{sup 2+} signals at g = 2.4 and g = 2.1 plus E{sub 1}' signal superposed to Fe{sup 3+} signal around g = 2.0.

A Group Increment Scheme for Infrared Absorption Intensities of Greenhouse Gases

Science.gov (United States)

Kokkila, Sara I.; Bera, Partha P.; Francisco, Joseph S.; Lee, Timothy J.

2012-01-01

A molecule's absorption in the atmospheric infrared (IR) window (IRW) is an indicator of its efficiency as a greenhouse gas. A model for estimating the absorption of a fluorinated molecule within the IRW was developed to assess its radiative impact. This model will be useful in comparing different hydrofluorocarbons and hydrofluoroethers contribution to global warming. The absorption of radiation by greenhouse gases, in particular hydrofluoroethers and hydrofluorocarbons, was investigated using ab initio quantum mechanical methods. Least squares regression techniques were used to create a model based on this data. The placement and number of fluorines in the molecule were found to affect the absorption in the IR window and were incorporated into the model. Several group increment models are discussed. An additive model based on one-carbon groups is found to work satisfactorily in predicting the ab initio calculated vibrational intensities.

DFT Calculation of IR Absorption Spectra for PCE-nH2O, TCE-nH2O, DCE-nH2O, VC-nH2O for Small and Water-Dominated Molecular Clusters

Science.gov (United States)

2017-10-31

VC-nH2O for Small and Water-Dominated Molecular Clusters October 31, 2017 Approved for public release; distribution is unlimited. L. Huang S.g...Calculation of IR Absorption Spectra for PCE-nH2O, TCE-nH2O, DCE-nH2O, VC-nH2O for Small and Water-Dominated Molecular Clusters L. Huang,1 S.G...nH2O molecular clusters using density function theory (DFT). DFT can provide interpretation of absorption spectra with respect to molecular

Biomass Burning Aerosol Absorption Measurements with MODIS Using the Critical Reflectance Method

Science.gov (United States)

Zhu, Li; Martins, Vanderlei J.; Remer, Lorraine A.

2010-01-01

This research uses the critical reflectance technique, a space-based remote sensing method, to measure the spatial distribution of aerosol absorption properties over land. Choosing two regions dominated by biomass burning aerosols, a series of sensitivity studies were undertaken to analyze the potential limitations of this method for the type of aerosol to be encountered in the selected study areas, and to show that the retrieved results are relatively insensitive to uncertainties in the assumptions used in the retrieval of smoke aerosol. The critical reflectance technique is then applied to Moderate Resolution Imaging Spectrometer (MODIS) data to retrieve the spectral aerosol single scattering albedo (SSA) in South African and South American 35 biomass burning events. The retrieved results were validated with collocated Aerosol Robotic Network (AERONET) retrievals. One standard deviation of mean MODIS retrievals match AERONET products to within 0.03, the magnitude of the AERONET uncertainty. The overlap of the two retrievals increases to 88%, allowing for measurement variance in the MODIS retrievals as well. The ensemble average of MODIS-derived SSA for the Amazon forest station is 0.92 at 670 nm, and 0.84-0.89 for the southern African savanna stations. The critical reflectance technique allows evaluation of the spatial variability of SSA, and shows that SSA in South America exhibits higher spatial variation than in South Africa. The accuracy of the retrieved aerosol SSA from MODIS data indicates that this product can help to better understand 44 how aerosols affect the regional and global climate.

RA Research reactor, Annual report 1986; Istrazivacki nuklearni reaktor RA - Izvestaj za 1986. godinu

Energy Technology Data Exchange (ETDEWEB)

Sotic, O [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1986-12-01

Research reactor RA Annual report for year 1985 is divided into two main parts to cover: (1) operation and maintenance and (2) activities related to radiation protection. [Serbo-Croat] Godisnji izvestaj po projektu 'Istrazivacki nuklearni reaktor RA' za 1986 godinu sastoji se od dva dela: prvi deo obuhvata pogon i odzavanje reaktora RA, a drugi poslove zastite od zracenja na reaktoru RA.

Optimization of silicon waveguides for gas detection application at mid-IR wavelengths

Science.gov (United States)

Butt, M. A.; Kozlova, E. S.

2018-04-01

There are several trace gases such as N2O, CO, CO2, NO, H2O, NO2, NH3, CH4 etc. which have their absorption peaks in Mid-IR spectrum These gases strongly absorb in the mid-IR > 2.5 μm spectral region due to their fundamental rotational and vibrational transitions. In this work, we modelled and optimized three different kinds of waveguides such as rib, strip and slot based on silicon platform to obtain maximum evanescent field ratio. These waveguides are designed at 3.39 μm and 4.67 μm which correspond to the absorption line of methane (CH4) and carbon monoxide (CO) respectively.

Distribution and flux of 226Ra and 228Ra in the Amazon River estuary

International Nuclear Information System (INIS)

Key, R.M.; Sarmiento, J.L.; Stallard, R.F.; Moore, W.S.

1985-01-01

Measurements of 226 Ra and 228 Ra in the Amazon River estuary show that desorption from riverborne suspended particulate matter in the estuary increases the riverine flux of both isotopes to the ocean by a factor of approximately 5 over the flux attributable to radium dissolved in the river water alone. The total Amazon flux supplies approximately 0.20% of the 226 Ra and approximately 2.6% of the 228 Ra standing crops in the near-surface Atlantic (0-200 m). Diffusive flux from estuarine and shelf sediments and desorption from resuspended sediments in the region of the estuary approximately double the estuarine 226 Ra concentration and quadruple the estuarine 228 Ra concentration above that caused by the dissolved and desorbed river components alone

Research nuclear reactor RA - Annual Report 1989; Istrazivacki nuklearni reaktor RA - Izvestaj za 1989. godinu

Energy Technology Data Exchange (ETDEWEB)

Sotic, O [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1989-12-15

Annual report concerning the project 'RA research nuclear reactor' for 1989, financed by the Serbian ministry of science is divided into two parts. First part is concerned with RA reactor operation and maintenance, which is the task of the Division for reactor engineering of the Institute for multidisciplinary studies and RA reactor engineering. Second part deals with radiation protection activities at the RA reactor which is the responsibility of the Institute for radiation protection. Scientific council of the Institute for multidisciplinary studies and RA reactor engineering has stated that this report describes adequately the activity and tasks fulfilled at the RA reactor in 1989. The scope and the quality of the work done were considered successful both concerning the maintenance and reconstruction, as well as radiation protection activities. [Serbo-Croat] Godisnji izvestaj po projektu 'Istrazivacki nuklearni reaktor RA' za 1989. godinu, koji finansira republicka zajednica za nauku SR Srbije po ugovoru br. 3705/1 sastoji se iz dva dela. Prvi deo obuhvata pogon i odrzavanje nuklearnog reaktora RA, sto predstavlja obavezu Odeljenja za reaktorski inzenjering u sastavu OOUR Instituta za multidisciplinarna istrazivanja i inzenjering RA. Drugi deo obuhvata poslove zastite od zracenja na reaktoru RA, sto predstavlja obavezu OOUR Instituta za zastitu od zracenja 'Zastita'. Naucno vece Instituta za multidisciplinarna istrazivanja i inzenjering RA ocenilo je da sadrzina ovog izvestaja odgovara izvrsenim poslovima na reaktoru RA u 1989. godini. Pozitivno se ocenjuje obim i kvalitet izvrsenih radova kako u pogledu odrzavanja i rekonstrukcije reaktora, tako i u pogledu poslova zastite od zracenja izvrsenih kod njega.

226 Ra in food

International Nuclear Information System (INIS)

Toader, M.

1993-01-01

Between 1986 and 1992 the author has evaluated natural levels of 226 Ra in some foods representing the major components of the diet in Bucharest population. The estimated daily intake by an adult was 72.5 mBq 226 Ra/day or 65.9 mBq 226 Ra/g.Ca. (Author)

Preparation and investigation of structural, magnetic and microwave absorption properties of cerium doped barium hexaferrite

Directory of Open Access Journals (Sweden)

P Kameli

2015-01-01

Full Text Available In this study the structure, magnetic and microwave absorption properties of cerium (Ce doped barium hexaferrite with general formulae BaCexFe12-xO19 (x=0.0, 0.05, 0.1, 0.15, 0.2 have been investigated. These samples have been prepared by sol- gel method. Influence of replacing Fe+3 ion by rare- earth Ce+3 ion on the structural, magnetic and microwave absorption properties have been investigated by X- ray diffraction (XRD, Fourier transform infrared (FT-IR, Vibrating sample magnetometer (VSM and vector network analyzer (VNA. X-ray diffraction analysis indicated that the samples are of single phase with space group p63/mmc. The magnetic properties of samples indicated that with the Ce doping the saturation magnetization show no regular behavior. Moreover, coercivity (Hc first decreased and reached to the minimum value for x=0.1 sample and then increased with Ce content increasing. Also, measurement of electromagnetic wave absorption in X and Ku frequency bands indicated that the maximum of reflection loss obtained for x=0.15 sample. Moreover, result indicated that absorption peak shifted toward a lower frequency when thickness was increased.

Spectrophotometric determination of palladium (II) with rubeanic acid (RA) in presence of pyridine, piperidine and 3-picoline

International Nuclear Information System (INIS)

Hassiruzzaman, M.; Hossain, M.A.; Rahman, G.M.M.; Kamal, A.S.M.; Kabir, M.H.; Mustafa, A.I.

1999-01-01

Unpretentious and exclusive methods for the spectrophotometric determination of trace amount of divalent palladium (II) have been developed with rubeanic acid (dithio-oxamide) in presence of secondary ligands like pyridine, piperidine and 3-picoline. Both direct and extraction spectrophotometry showed that coloured rubeanates are only stable in acidic medium. The violent yellow coloured products are formed below ph 5.0 with an absorption maxima at 416.0 and 422.0 (pyridine), 405.0 and 416.5 (piperidine) and 418.0 and 422.0 (3-picoline) both in direct and isoamyl alcohol (IAA) extracted system, respectively. Results indicate that the highest sensitivity and molar absorptivity of Pd-RA pyridine system in direct spectrophotometry were 0.01497 mu g Pd(II) cm/sup -2/ and 7107.89 L mol sup -1/ cm/sup -1/ respectively. IAA extracted Pd-RA-piperidine system was found to give a sensitivity of 0.01087 mu g(Pd(II) cm /sup -2/ and molar absorptivity of 9788.80 L mol /sup -1/ cm/sup -1/ which were the highest of all the system. The effects due to variation of pH, reagent concentrations, order of addition of reagents, time, temperature and solvent media on the absorption spectra have been investigated and the optimum conditions determined. The effects of diverse ions and their tolerance limit have also been studies. (author)

THE STUDY OF CLINOPTILOLITE MODIFIED WITH3d METALS HALIDES BY IR AND DIFFUSE REFLECTANCE SPECTROSCOPY

Directory of Open Access Journals (Sweden)

T. L. Rakitskaya

2015-11-01

Full Text Available The results of investigation of natural clinoptilolite (N-CLI and that modified with 3d metal halides (MeCl2/N-CLI, where Me are Cu, Co, and Mn by IR and diffuse reflectance spectroscopy are summarized. A band at 3437 cm-1 assigned to stretching vibrations of hydroxyl groups (nOH is found in the IR spectrum of the N-CLI sample. A location of the band was practically the same as for all above MeCl2/N-CLI samples. A band of middle intensity at 1638 cm-1 in the range of deformation vibrations of zeolite water observed in the IR spectrum of N-CLI slightly displays to lower frequencies in the case of the modified samples. An intensive wide band of a complex shape in the range from 1250 to 980 cm-1 assigned to Si–O–Si and Si–O–Al vibrations appears in IR spectra of all samples. A doublet band of middle intensity at 797 and 778 cm-1 is assigned to external symmetric stretching T-O vibrations and a band at 606 cm-1-to vibrations of a double ring. A location of the above bands is the same for all listed samples but their intensity is higher for MnCl2/N-CLI and CoCl2/N-CLI samples. After the reaction with ozone, significant changes in the IR spectra are observed only for MnCl2/N-CLI. They are due to MnO2 formation on the clinoptilolite surface resulting in a high frequency displacement of some bands. Based on UV-vi spectroscopy results, it is reasonable to make conclusions about the coordination and valence state of a central atom in the MeCl2/N-CLI samples under study. A location of charge transfer bands for these samples only slightly differs from that for N-CLI however the intensity of such bands increases for the MeCl2/N-CLI samples. The UV-vis spectrum of MnCl2/N-CLI changes after the reaction with ozone: the appearance of new bands of  charge transfer at 363 and 354 nm and also the two-fold increase in intensity of a charge transfer band at 272 nm in comparison with those of N-CLI and MnCl2/N-CLI are the evidence of change in both the

Analysis of bacteria on steel surfaces using reflectance micro-Fourier transform infrared spectroscopy.

Science.gov (United States)

Ojeda, Jesús J; Romero-González, María E; Banwart, Steven A

2009-08-01

Reflectance micro-Fourier transform infrared (FT-IR) analysis has been applied to characterize biofilm formation of Aquabacterium commune, a common microorganism present on drinking water distribution systems, onto the increasingly popular pipe material stainless steel EN1.4307. The applicability of the reflectance micro-FT-IR technique for analyzing the bacterial functional groups is discussed, and the results are compared to spectra obtained using more conventional FT-IR techniques: transmission micro-FT-IR, attenuated transmitted reflectance (ATR), and KBr pellets. The differences between the infrared spectra of wet and dried bacteria, as well as free versus attached bacteria, are also discussed. The spectra obtained using reflectance micro-FT-IR spectroscopy were comparable to those obtained using other FT-IR techniques. The absence of sample preparation, the potential to analyze intact samples, and the ability to characterize opaque and thick samples without the need to transfer the bacterial samples to an infrared transparent medium or produce a pure culture were the main advantages of reflectance micro-FT-IR spectroscopy.

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.

Reproduction of the RA reactor fuel element fabrication; Reprodukcija izrade gorivnog elementa za reaktor RA

Energy Technology Data Exchange (ETDEWEB)

Novakovic, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1961-12-15

This document includes the following nine reports: Final report on task 08/12 - testing the Ra reactor fuel element; design concept for fabrication of RA reactor fuel element; investigation of the microstructure of the Ra reactor fuel element; Final report on task 08/13 producing binary alloys with Al, Mo, Zr, Nb and B additions; fabrication of U-Al alloy; final report on tasks 08/14 and 08/16; final report on task 08/32 diffusion bond between the fuel and the cladding of the Ra reactor fuel element; Final report on task 08/33, fabrication of the RA reactor fuel element cladding; and final report on task 08/36, diffusion of solid state metals. Ovaj rad sadrzi devet priloga: 1. Zavrsni izvestaj o podzadatku 08/12, ispitivanje elementa goriva reaktora RA; 2. Koncepcija izrade gorivnog elementa reaktora RA; 3. Ispitivanje mikrostrukture gorivnog elementa reaktora RA; 4. Zavrsni izvestaj o podzadatku 08/13, dobijanje binarnih legura urana sa legirajucim komponentama Al, Mo, Zr, Nb i B; 5. Dobijanje legure U-Al; 6. Zavrsni izvestaj o podzadacima 08/14 i 08/16; 7. Zavrsni izvestaj o podzadatku 08/32, difuziona veza goriva i kosuljice gorivnog elementa reaktora RA; 8. Zavrsni izvestaj o podzadatku 08/33, izrada kosuljice gorivnog elementa reaktora RA; 9. Zavrsni izvestaj o podzadatku 08/36, difuzija kod metala u cvrstom stanju.

X-ray absorption and reflection as probes of the GaN conduction bands: Theory and experiments

Energy Technology Data Exchange (ETDEWEB)

Lambrecht, W.R.L.; Rashkeev, S.N.; Segall, B. [Case Western Reserve Univ., Cleveland, OH (United States)] [and others

1997-04-01

X-ray absorption measurements are a well-known probe of the unoccupied states in a material. The same information can be obtained by using glancing angle X-ray reflectivity. In spite of several existing band structure calculations of the group III nitrides and previous optical studies in UV range, a direct probe of their conduction band densities of states is of interest. The authors performed a joint experimental and theoretical investigation using both of these experimental techniques for wurtzite GaN.

Spectral reflectance relationships to leaf water stress

Science.gov (United States)

Ripple, William J.

1986-01-01

Spectral reflectance data were collected from detached snapbean leaves in the laboratory with a multiband radiometer. Four experiments were designed to study the spectral response resulting from changes in leaf cover, relative water content of leaves, and leaf water potential. Spectral regions included in the analysis were red (630-690 nm), NIR (760-900 nm), and mid-IR (2.08-2.35 microns). The red and mid-IR bands showed sensitivity to changes in both leaf cover and relative water content of leaves. The NIR was only highly sensitive to changes in leaf cover. Results provided evidence that mid-IR reflectance was governed primarily by leaf moisture content, although soil reflectance was an important factor when leaf cover was less than 100 percent. High correlations between leaf water potentials and reflectance were attributed to covariances with relative water content of leaves and leaf cover.

Modelling terahertz radiation absorption and reflection with computational phantoms of skin and associated appendages

Science.gov (United States)

Vilagosh, Zoltan; Lajevardipour, Alireza; Wood, Andrew

2018-01-01

Finite-difference time-domain (FDTD) computational phantoms aid the analysis of THz radiation interaction with human skin. The presented computational phantoms have accurate anatomical layering and electromagnetic properties. A novel "large sheet" simulation technique is used allowing for a realistic representation of lateral absorption and reflection of in-vivo measurements. Simulations carried out to date have indicated that hair follicles act as THz propagation channels and confirms the possible role of melanin, both in nevi and skin pigmentation, to act as a significant absorber of THz radiation. A novel freezing technique has promise in increasing the depth of skin penetration of THz radiation to aid diagnostic imaging.

226Ra and 228Ra in ground water of the Cambrian-Ordovician Aquifer System in northern Illinois

International Nuclear Information System (INIS)

Gilkeson, R.H.; Holtzman, R.B.

1982-01-01

Over a large region of Illinois, ground water of the Cambrian-Ordovician Aquifer System exceeds the US EPA drinking water standard of 5 pCi/L for the combined concentration of 226 Ra and 228 Ra. 226 Ra concentrations range from 226 Ra is the geochemistry of uranium in the ground-water flow system, while the 228 Ra activity in ground water which ranges from 232 Th-bearing minerals in the aquifer strata. The comparison of recent analyses to historical data gathered over the last 20 years indicates that, with few exceptions, 226 Ra and 228 Ra activities in ground water have remained constant. The combined concentrations of the two nuclides in ground water of the aquifer system ranged from 226 Ra concentrations were high (greater than or equal to 10 pCi/L), those of 228 Ra were low (less than or equal to 2 pCi/L), but, with few exceptions, in regions where 228 Ra concentrations were high, those of 226 Ra were also high. The range of values raises questions concerning the validity of the US EPA regulation which requires analysis for 228 Ra only when the concentration of 226 Ra exceeds 3.0 pCi/L

Effect of in-material losses on terahertz absorption, transmission, and reflection in photonic crystals made of polar dielectrics

Energy Technology Data Exchange (ETDEWEB)

Serebryannikov, Andriy E., E-mail: andser@amu.edu.pl [Faculty of Physics, Adam Mickiewicz University, 61-614 Poznań (Poland); Nanotechnology Research Center—NANOTAM, Bilkent University, 06800 Ankara (Turkey); Nojima, S. [Yokohama City University, Department of Nanosystem Science, Graduate School of Nanobioscience, Kanazawa Ku, 22-2 Seto, Yokohama, Kanagawa 2360027 (Japan); Alici, K. B. [TUBITAK Marmara Research Center, Materials Institute, 41470 Gebze, Kocaeli (Turkey); Ozbay, Ekmel [Nanotechnology Research Center—NANOTAM, Bilkent University, 06800 Ankara (Turkey)

2015-10-07

The effect of the material absorption factor on terahertz absorption (A), transmittance (T), and reflectance (R) for slabs of PhC that comprise rods made of GaAs, a polar dielectric, is studied. The main goal was to illustrate how critical a choice of the absorption factor for simulations is and to indicate the importance of the possible modification of the absorption ability by using either active or lossy impurities. The spectra of A, T, and R are strongly sensitive to the location of the polaritonic gap with respect to the photonic pass and stop bands connected with periodicity that enables the efficient combination of the effects of material and structural parameters. It will be shown that the spectra can strongly depend on the utilized value of the material absorption factor. In particular, both narrow and wide absorption bands may appear owing to a variation of the material parameters with a frequency in the vicinity of the polaritonic gap. The latter are often achieved at wideband suppression of transmission, so that an ultra-wide stop band can appear as a result of adjustment of the stop bands having different origin. The results obtained at simultaneous variation of the absorption factor and frequency, and angle of incidence and frequency, indicate the possibility of the existence of wide ranges of tolerance, in which the basic features do remain. This allows for mitigating the accuracy requirements for the absorption factor in simulations and promises the efficient absorption of nonmonochromatic waves and beams with a wide angular spectrum. Suppression of narrowband effects in transmission is demonstrated at rather large values of the absorption factor, when they appear due to either the defect modes related to structural defects or dispersion inspired variations of the material parameters in the vicinity of the polaritonic gap. Comparison with auxiliary structures helps one to detect the common features and differences of homogeneous slabs and slabs of a

Automated measurement of 224Ra and 226Ra in water

International Nuclear Information System (INIS)

Dimova, N.; Burnett, W.C.; Horwitz, E.P.; Lane-Smith, D.

2007-01-01

We present a new simple approach for automated, non-destructive measurement of the alpha-emitting radium isotopes ( 223 Ra, 224 Ra, and 226 Ra) in water based on the emanation of their respective radon daughters ( 219 Rn, 220 Rn, and 222 Rn). The method combines the high adsorption uptake of MnO 2 Resin for radium (K d =2.4x10 4 ml/g) over a wide pH range with the simplicity of the activity registration using a commercial radon-in-air analyzer (RAD7, DURRIDGE Company, Inc). Radium is first adsorbed onto the MnO 2 Resin by passing a water sample through the resin packed in a gas-tight glass cartridge. The same cartridge is then connected to the radon analyzer via a simple tubing system to circulate air through the resin and a drying system. The efficiency of the proposed system is determined by running standards prepared in the same manner. Our results indicate that the efficiency for 226 Ra is >22% if both 218 Po and 214 Po counts are collected. This is comparable with typical efficiencies for alpha spectrometry but with much less sample preparation. We estimate that an MDA of 0.8 pCi/L for 226 Ra may be obtained with this new approach using a 1 L water sample and less than 4 h of counting

Determination of 226 Ra and 228 Ra in mineral spring waters of the Aguas da Prata region

International Nuclear Information System (INIS)

Oliveira, J. de.

1993-01-01

Concentration levels of 226 Ra and 228 Ra have been analysed in most of the mineral spring waters available in the Aguas da Prata region. The 226 Ra and 228 Ra were determined by coprecipitation with barium sulphate. The 226 Ra was determined by gross alpha counting of the Ba(Ra)SO 4 precipitate. The determination of 228 Ra was done by measuring the gross beta activity of the same precipitate. Both measurements were carried out in a low background gas flow proportional counter. Dose calculations were performed in order to evaluate the relative importance of such radionuclides to the radiation exposure due to the ingestion of these waters. Based upon measured concentrations, committed effective doses up to 5.5 x 10 -1 mSv/y and 1.0 x 10 -2 mSv/y were observed for 226 Ra and 228 Ra, respectively. These results show that 226 Ra is the main contributor to radiation exposure. (author)

High-resolution IR absorption spectroscopy of polycyclic aromatic hydrocarbons in the 3 μm region: role of hydrogenation and alkylation

Science.gov (United States)

Maltseva, Elena; Mackie, Cameron J.; Candian, Alessandra; Petrignani, Annemieke; Huang, Xinchuan; Lee, Timothy J.; Tielens, Alexander G. G. M.; Oomens, Jos; Buma, Wybren Jan

2018-03-01

Aim. We aim to elucidate the spectral changes in the 3 μm region that result from chemical changes in the molecular periphery of polycyclic aromatic hydrocarbons (PAHs) with extra hydrogens (H-PAHs) and methyl groups (Me-PAHs). Methods: Advanced laser spectroscopic techniques combined with mass spectrometry were applied on supersonically cooled 1,2,3,4-tetrahydronaphthalene, 9,10-dihydroanthracene, 9,10-dihydrophenanthrene, 1,2,3,6,7,8-hexahydropyrene, 9-methylanthracene, and 9,10-dimethylanthracene, allowing us to record mass-selective and conformationally selective absorption spectra of the aromatic, aliphatic, and alkyl CH-stretches in the 3.175 - 3.636 µm region with laser-limited resolution. We compared the experimental absorption spectra with standard harmonic calculations and with second-order vibrational perturbation theory anharmonic calculations that use the SPECTRO program for treating resonances. Results: We show that anharmonicity plays an important if not dominant role, affecting not only aromatic, but also aliphatic and alkyl CH-stretch vibrations. The experimental high-resolution data lead to the conclusion that the variation in Me- and H-PAHs composition might well account for the observed variations in the 3 μm emission spectra of carbon-rich and star-forming regions. Our laboratory studies also suggest that heavily hydrogenated PAHs form a significant fraction of the carriers of IR emission in regions in which an anomalously strong 3 μm plateau is observed.

Magnetic structure of post-perovskite compound CaIrO3

International Nuclear Information System (INIS)

Ohgushi, Kenya; Ohsumi, Hiroyuki; Yamaura, Jun-ichi; Arima, Taka-hisa

2014-01-01

We have performed resonant X-ray diffraction experiments at the Ir L absorption edges for a post-perovskite compound CaIrO 3 with a Ir 4+ : (t 2g ) 5 electronic configuration. By observing the magnetic signals, we could clearly see that the magnetic structure was a striped ordering with antiferromagnetic moments along the c axis and that the wave function of a t 2g hole is strongly spin-orbit entangled, the J eff = 1/2 state. The observed spin arrangement is consistent with a theoretical work predicting a unique superexchange interaction called the quantum compass model. Our studies stimulate further studies for developing novel quantum states in iridium oxides. (author)

Nuclear Reactor RA Safety Report, Vol. 4, Reactor

International Nuclear Information System (INIS)

1986-11-01

RA research reactor is thermal heavy water moderated and cooled reactor. Metal uranium 2% enriched fuel elements were used at the beginning of its operation. Since 1976, 80% enriched uranium oxide dispersed in aluminium fuel elements were gradually introduced into the core and are the only ones presently used. Reactor core is cylindrical, having diameter 40 cm and 123 cm high. Reaktor core is made up of 82 fuel elements in aluminium channels, lattice is square, lattice pitch 13 cm. Reactor vessel is cylindrical made of 8 mm thick aluminium, inside diameter 140 cm and 5.5 m high surrounded with neutron reflector and biological shield. There is no containment, the reactor building is playing the shielding role. Three pumps enable circulation of heavy water in the primary cooling circuit. Degradation of heavy water is prevented by helium cover gas. Control rods with cadmium regulate the reactor operation. There are eleven absorption rods, seven are used for long term reactivity compensation, two for automatic power regulation and two for safety shutdown. Total anti reactivity of the rods amounts to 24%. RA reactor is equipped with a number of experimental channels, 45 vertical (9 in the core), 34 in the graphite reflector and two in the water biological shield; and six horizontal channels regularly distributed in the core. This volume include detailed description of systems and components of the RA reactor, reactor core parameters, thermal hydraulics of the core, fuel elements, fuel elements handling equipment, fuel management, and experimental devices [sr

IR sensitivity enhancement of CMOS Image Sensor with diffractive light trapping pixels.

Science.gov (United States)

Yokogawa, Sozo; Oshiyama, Itaru; Ikeda, Harumi; Ebiko, Yoshiki; Hirano, Tomoyuki; Saito, Suguru; Oinoue, Takashi; Hagimoto, Yoshiya; Iwamoto, Hayato

2017-06-19

We report on the IR sensitivity enhancement of back-illuminated CMOS Image Sensor (BI-CIS) with 2-dimensional diffractive inverted pyramid array structure (IPA) on crystalline silicon (c-Si) and deep trench isolation (DTI). FDTD simulations of semi-infinite thick c-Si having 2D IPAs on its surface whose pitches over 400 nm shows more than 30% improvement of light absorption at λ = 850 nm and the maximum enhancement of 43% with the 540 nm pitch at the wavelength is confirmed. A prototype BI-CIS sample with pixel size of 1.2 μm square containing 400 nm pitch IPAs shows 80% sensitivity enhancement at λ = 850 nm compared to the reference sample with flat surface. This is due to diffraction with the IPA and total reflection at the pixel boundary. The NIR images taken by the demo camera equip with a C-mount lens show 75% sensitivity enhancement in the λ = 700-1200 nm wavelength range with negligible spatial resolution degradation. Light trapping CIS pixel technology promises to improve NIR sensitivity and appears to be applicable to many different image sensor applications including security camera, personal authentication, and range finding Time-of-Flight camera with IR illuminations.

RA research nuclear reactor - Annual report 1985; Istrazivacki nuklearni reaktor RA - Izvestaj za 1985. godinu

Energy Technology Data Exchange (ETDEWEB)

NONE

1985-12-01

Research reactor RA Annual report for year 1985 is divided into two main parts to cover: (1) operation and maintenance and (2) activities related to radiation protection. [Serbo-Croat] Godisnji izvestaj po projektu 'Istrazivacki nuklearni reaktor RA' za 1985 godinu sastoji se od dva dela: prvi deo obuhvata pogon i odzavanje reaktora RA, a drugi poslove zastite od zracenja na reaktoru RA.

Šilauogių (Vaccinium corymbosum L.) uogų antocianų kokybinės ir kiekybinės sudėties tyrimas

OpenAIRE

Nikolajevas, Laurynas

2008-01-01

Tirta šilauogės (Vaccinium corymbosum L.) vaisių biologiškai aktyvių junginių (antocianų) kiekinė ir kokybinė sudėtis. Tyrimo tikslas. Ištirti Lietuvoje introdukuotų šilauogių (Vaccinium corymbosum L.) veislių uogų kokybinę ir kiekybinę sudėtį, bei įvertinti uogų, uogos luobelių, minkštimo ir išspaudų ekstraktų antioksidacinį poveikį. Sodinių šilauogių kultūra sukurta XX amžiaus pradžioje JAV. Į Lietuvą pirmosios Šilauogės įvežtos 1969-aisiais metais ir iki šiol tyrinėjamos Lietuvos mokslinin...

Solubility and IR studies of gamma-irradiated arabinoxylan

International Nuclear Information System (INIS)

Ebringerova, A.; Kacurakova, M.; Hromadkova, Z.; Pruzinec, J.

1989-01-01

The structural and solubility changes of a water-insoluble arabinoxylan with a low degree of branching was studied after γ-irradiation by IR spectroscopy and chemical analysis of the polysaccharide and its polymeric fractions. New functional groups like hydroperoxidic, carbonylic and endiolic ones were found after irradiation. The IR spectra shows that the structural changes involved by radiolytic treatment are reflected in the shape of the IR spectra of both polymeric fractions. The ratio of absorbance of the peaks at 1725 and 2920 cm -1 increased with radiation dose. (author) 17 refs.; 2 figs.; 2 tabs

Spectral slopes of the absorption coefficient of colored dissolved and detrital material inverted from UV-visible remote sensing reflectance.

Science.gov (United States)

Wei, Jianwei; Lee, Zhongping; Ondrusek, Michael; Mannino, Antonio; Tzortziou, Maria; Armstrong, Roy

2016-03-01

The spectral slope of the absorption coefficient of colored dissolved and detrital material (CDM), S cdm (units: nm -1 ), is an important optical parameter for characterizing the absorption spectral shape of CDM. Although highly variable in natural waters, in most remote sensing algorithms, this slope is either kept as a constant or empirically modeled with multiband ocean color in the visible domain. In this study, we explore the potential of semianalytically retrieving S cdm with added ocean color information in the ultraviolet (UV) range between 360 and 400 nm. Unique features of hyperspectral remote sensing reflectance in the UV-visible wavelengths (360-500 nm) have been observed in various waters across a range of coastal and open ocean environments. Our data and analyses indicate that ocean color in the UV domain is particularly sensitive to the variation of the CDM spectral slope. Here, we used a synthesized data set to show that adding UV wavelengths to the ocean color measurements will improve the retrieval of S cdm from remote sensing reflectance considerably, while the spectral band settings of past and current satellite ocean color sensors cannot fully account for the spectral variation of remote sensing reflectance. Results of this effort support the concept to include UV wavelengths in the next generation of satellite ocean color sensors.

Noninvasive method for the assessment of dermal uptake of pesticides using attenuated total reflectance infrared spectroscopy.

Science.gov (United States)

Carden, Angela; Yost, Michael G; Fenske, Richard A

2005-03-01

Dermal absorption of pesticides is a primary exposure route for agricultural workers, but is not well characterized. Current measurement techniques are either invasive, such as tape-stripping, or require extensive sample preparation or analysis time, such as urinary metabolite monitoring or wipe sampling followed by gas chromatography analysis. We present the application of a noninvasive, spectroscopic approach for the measurement of pesticide absorption into skin. Attenuated total reflectance infrared spectroscopy (ATR-IR) was used to monitor directly the absorption of two pesticides--captan and azinphos-methyl--in ten volunteers over 20 min under occlusive conditions. We found substantial variability in absorption across subjects. Our results were comparable to those measured by the more traditional method of wipe-sampling followed by extraction and gas chromatography analysis. Multivariate data analysis, in the form of multivariate curve resolution (MCR), is a novel addition to this type of experiment, yielding time-resolved information unachievable by standard methods. These data are potentially more informative than the monitoring of blood or urinary metabolites because they can be acquired in essentially real-time, allowing observations of pesticide absorption on a rapid timescale rather than over hours or days.

Radiochemical determination and separation or total radium, 226Ra and 224Ra

International Nuclear Information System (INIS)

Suarez, J. A.; Gonzalez, J. A.; Pablo, M. A. de

1987-01-01

Radiochemical purification and separation of radium has been carried out and the determination of total radium solubilized in aqueous samples has been studied assuming that all the alpha emitters of the sample have their origin in the 226Ra and elements of its desintegration chain. Also, the activities of 22Ra and 226 Ra have been evaluated separately doing a measurement after the chemical separation of the radium and another one 10 days after. (Author) 9 refs

Determination of 226Ra and 224Ra in drinking waters by liquid scintillation counting

International Nuclear Information System (INIS)

Manjon, G.; Vioque, I.; Moreno, H.; Garcia-Tenorio, R.; Garcia-Leon, M.

1997-01-01

A method for the determination of Ra-isotopes in water samples has been developed. Ra is coprecipitated with Ba as sulphate. The precipitate is then dissolved with EDTA and counted with a liquid scintillation system after mixing with a scintillation cocktail. The study of the temporal evolution of the separated activity gives the isotopic composition of the sample, i.e. the 224 Ra and 226 Ra contribution to the total activity. The method has been applied to some Spanish drinking waters. (author)

Infrared reflection properties and modelling of in situ reflection measurements on plasma-facing materials in Tore Supra

International Nuclear Information System (INIS)

Reichle, R; Desgranges, C; Faisse, F; Pocheau, C; Lasserre, J-P; Oelhoffen, F; Eupherte, L; Todeschini, M

2009-01-01

Tore Supra has-like ITER-reflecting internal surfaces, which can perturb the machine protection systems based on infrared (IR) thermography. To ameliorate this situation, we have measured and modelled in the 3-5 μm wavelength range the bi-directional reflection distribution function (BRDF) of wall material samples from Tore Supra and conducted in situ reflection measurements and simulated them with the CEA COSMOS code. BRDF results are presented for B 4 C and carbon fibre composite (CFC) tiles. The hemispherical integrated reflection ranges from 0.12 for the B 4 C sample to 0.39 for a CFC tile from the limiter erosion zone. In situ measurements of the IR reflection of a blackbody source off an ICRH and an LHCD antenna of Tore Supra are well reproduced by the simulation.

Infrared reflection properties and modelling of in situ reflection measurements on plasma-facing materials in Tore Supra

Energy Technology Data Exchange (ETDEWEB)

Reichle, R; Desgranges, C; Faisse, F; Pocheau, C [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Lasserre, J-P; Oelhoffen, F; Eupherte, L; Todeschini, M [CEA, DAM, CESTA, F-33114 Le Barp (France)

2009-12-15

Tore Supra has-like ITER-reflecting internal surfaces, which can perturb the machine protection systems based on infrared (IR) thermography. To ameliorate this situation, we have measured and modelled in the 3-5 {mu}m wavelength range the bi-directional reflection distribution function (BRDF) of wall material samples from Tore Supra and conducted in situ reflection measurements and simulated them with the CEA COSMOS code. BRDF results are presented for B{sub 4}C and carbon fibre composite (CFC) tiles. The hemispherical integrated reflection ranges from 0.12 for the B{sub 4}C sample to 0.39 for a CFC tile from the limiter erosion zone. In situ measurements of the IR reflection of a blackbody source off an ICRH and an LHCD antenna of Tore Supra are well reproduced by the simulation.

RefleX: X-ray absorption and reflection in active galactic nuclei for arbitrary geometries

Science.gov (United States)

Paltani, S.; Ricci, C.

2017-11-01

Reprocessed X-ray radiation carries important information about the structure and physical characteristics of the material surrounding the supermassive black hole (SMBH) in active galactic nuclei (AGN). We report here on a newly developed simulation platform, RefleX, which allows to reproduce absorption and reflection by quasi-arbitrary geometries. We show here the reliability of our approach by comparing the results of our simulations with existing spectral models such as pexrav, MYTorus and BNTorus. RefleX implements both Compton scattering on free electrons and Rayleigh scattering and Compton scattering on bound electrons. We show the effect of bound-electron corrections on a torus geometry simulated like in MYTorus. We release with this paper the RefleX executable, as well as RXTorus, a model that assumes absorption and reflection from a torus with a varying ratio of the minor to major axis of the torus. To allow major flexibility RXTorus is also distributed in three components: absorbed primary emission, scattered radiation and fluorescent lines. RXTorus is provided for different values of the abundance, and with (atomic configuration) or without (free-electron configuration) taking into account Rayleigh scattering and bound electrons. We apply the RXTorus model in both configurations on the XMM-Newton and NuSTAR spectrum of the Compton-thick AGN NGC 424 and find that the models are able to reproduce very well the observations, but that the assumption on the bound or free state of the electrons has significant consequences on the fit parameters. RefleX executable, user manual and example models are available at http://www.astro.unige.ch/reflex. A copy of the RefleX executable is also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/607/A31

Assessment of annual effective dose from 238U and 226Ra due to consumption of foodstuffs by inhabitants of Tehran city (IR)

International Nuclear Information System (INIS)

Hosseini, T.; Fathivand, A. A.; Abbasisiar, F.; Karimi, M.; Barati, H.

2006-01-01

The concentrations of 238 U and 226 Ra were determined in different foodstuffs purchased from markets in Tehran. Determinations of the radionuclides have been carried out using alpha spectrometry technique, on samples of egg, lentil, potato, rice, soya, spinach, tea and wheat. Average concentrations of natural radionuclides and foodstuff consumption rate were used to assess annual intake and based on intake values, the annual effective ingestion dose has been estimated for Tehran city residents. The measurement results show that soya has the maximum concentration of 238 U equal to 15.6 ± 2.6 mBq kg -1 and tea has the maximum concentration of 226 Ra equal to 1153.3 ± 265.3 mBq kg -1 . Besides, the maximum annual effective dose from 238 U and 226 Ra were assessed to be 2.88 x 10 -2 ±7.20 x 10 -3 and 2.15 ± 0.54 μSv, respectively, from wheat samples. (authors)

Does a family history of RA influence the clinical presentation and treatment response in RA?

Science.gov (United States)

Frisell, Thomas; Saevarsdottir, Saedis; Askling, Johan

2016-06-01

To assess whether family history of rheumatoid arthritis (RA), among the strongest risk factors for developing RA, also carries information on the clinical presentation and treatment response. The prospective Swedish Rheumatology register was linked to family history of RA, defined as diagnosed RA in any first-degree relative, ascertained through the Swedish Multi-Generation and Patient registers. Clinical presentation was examined among patients with early RA 2000-2011 (symptom onset clinical characteristics, drug survival, European League Against Rheumatism (EULAR) response and change in disease activity at 3 and 6 months was estimated using linear and generalised logistic regression models. Correlation in relatives' response measures was also assessed. Patients with early RA with family history of RA were more often rheumatoid factor positive, but with no other clinically meaningful differences in their clinical presentation. Family history of RA did not predict response to MTX or TNFi, with the possible exception of no versus good EULAR response to TNFi at 6 months (OR=1.4, 95% CI 1.1 to 1.7). Having a relative who discontinued TNFi within a year increased the odds of doing the same (OR=3.7, 95% CI 1.8 to 7.5), although we found no significant familial correlations in change in disease activity measures. Family history of RA did not modify the clinical presentation of RA or predict response to standard treatment with MTX or TNFi. Treatment response, particularly drug survival, may itself be familial. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Determination of ''226Ra by Alpha Spectrometry by Using ''225Ra as Yield Tracer

International Nuclear Information System (INIS)

Crespo, M. T.; Oller, O.

1999-01-01

A method for the determination of low-level ''226 Ra in environmental and geological samples by alpha spectrometry is described. The method is based on the use of ''225 Ra from ''229 Th as yield tracer and has been developed to analyze U, Th and Ra in the same sample. (Author) 12 refs

A new determination method of 226Ra, 224Ra, and 228Th in water

International Nuclear Information System (INIS)

Horiuchi, Kimiko; Murakami, Yukio.

1981-01-01

A new method for the determination of 226 Ra, 224 Ra and 228 Th in water samples is described. It consists of extraction of 222 Rn and 220 Rn into a scintillator-toluene solution in equilibrium with 226 Ra and 224 Ra and the application of integral counting techniques with a liquid scintillation counter. One liter water sample, weakly acidified with hydrochloric acid, is transferred to a glass bottle, and vigorously bubbled with a stream of nitrogen to expel any radon or thoron in the water sample. Twenty five ml of the scintillator-toluene solution is added to the bottle (time is recorded). The bottle is stoppered with a Teflon stopper and kept at an upside-down position for a given period of time (usually 4 -- 16 days) to allow radon and thoron in partial equilibrium with their parent nuclides. Then, the sample system is vigorously shaken for 2 m and the organic layer is gently transferred to a counting vial through a specially devised transferring tube which is connected to the bottle. The initial counting time is set at 4 h after the separation of organic layer. The measurements are repeated 3 times each immediately and after 106 h from the initial counting time. From these results, the integral counting rates of radon and thoron at the initial counting time are easily obtained. The activities of 226 Ra, 224 Ra and 228 Th in the water sample are calculated from these integral counting rates by the proposed formulas. Some data on the 226 Ra and 224 Ra contents of mineral springs are presented. The lowest detection limits for 226 Ra and 224 Ra were 1.10 x 10 -12 and 1.47 x 10 -9 Ci, respectively. The present method is rapid, easy and accurate and eliminates a time-consuming sealing of the sample in Curie bottle and tedious procedure to transfer the sample gas through a vacuum system to the detector. (author)

X-ray-phase and IR-spectral study of clay rocks mineral content of the Caspian Sea Gulf depression

International Nuclear Information System (INIS)

Zakonov, A.N.; Mukhanova, M.U.

2000-01-01

Samples of clays selected from different oil fields (Sazankurak, Kemerkol, Kozha and others) and deposition depths are examined on both the X-ray diffractometers (Dron-2 and Dron-4) and the infrared-spectrometers (IR-20). In this diagnostic the American file with different minerals X-ray systematized data is used. The X-ray reflections, which are in compliance with suitable inter-plane distances and clay impurities reflex intensities are determined. With confirmation purpose for mineral content correctness obtained according X-ray-phase analysis the infrared-spectrometric method is used, in which principal attention was paid to absorption field (3,400-3,700 cm -1 ) of H 2 O and OH valency frequency vibrations

Association between IGF-IR gene polymorphisms and productive and reproductive traits in Holstein cows Associação entre polimorfismos do gene IGF-IR e características produtivas e reprodutivas em fêmeas bovinas da raça Holandesa

Directory of Open Access Journals (Sweden)

W. Schoenau

2005-12-01

Full Text Available The association between single-strand conformation polymorphism (SSCP in the gene of insulin-like growth factor-I receptor (IGF-IR and age at first calving (AFC, calving interval (CI, lactation length (LL, and milk yield (MY was studied using 106 graded Holstein females. The polimerase chain reaction (PCR with specific initiating oligonucleotides, resulted an amplified fragment of 335pb. The population genotypes frequencies were 82.1% and 17.9%, for AA and AB genotypes, respectively. The frequency of A allele was 0.91 and 0.09 of B allele. No association between the identified polymorphism and AFC, CI, and MY was observed. The LL was positively associated (PEstudou-se a associação entre polimorfismos de conformação de fita simples (SSCP no gene do receptor do fator-I de crescimento semelhante à insulina (IGF-IR e idade ao primeiro parto (IPP, intervalo entre partos (IEP, duração da lactação (DL e produção de leite (PL, em 106 fêmeas puras por cruza da raça Holandesa. A reação em cadeia da polimerase (PCR com oligonucleotídeos iniciadores específicos gerou um fragmento de 335pb. A freqüência genotípica da população para o polimorfismo foi 82,1% de indivíduos homozigotos para o alelo A e 17,9% de heterozigotos (AB. A freqüência do alelo A foi 0,91 e a do alelo B, 0,09. Não foi encontrada associação entre o polimorfismo estudado e as características IPP, IEP e PL. A característica DL foi positivamente associada (P<0,05 à ausência do alelo B. A lactação dos animais portadores do genótipo AA foi mais longa.

Angular absorption of iridium - ICW12 needles: practical considerations

International Nuclear Information System (INIS)

Szymczyk, W.; Lesiak, J.

1984-01-01

An analysis was made of two potential sources of error in Ir 192 dosimetry: the effect of angular absorption and the differences in the ionization constants found in literature. Corrections for selfabsorption in the ICW12 iridium source were determined from measurements and calculations. It was found that the decrease in the dose caused by the angular absorption in the central therapeutic area of a typical implantation can exceed 5 percent. The need for employing the concept of ''constant exposure rate'' is stressed as well as that for using angular absorption in the form of absorption. 13 refs., 6 figs., 1 tab. (author)

Thermal behavior of J-aggregates in a Langmuir-Blodgett film of pure merocyanine dye investigated by UV-visible and IR absorption spectroscopy.

Science.gov (United States)

Hirano, Yoshiaki; Tateno, Shinsuke; Maio, Ari; Ozaki, Yukihiro

2009-03-05

We have characterized the structure of J-aggregate in a Langmuir-Blodgett film of pure merocyanine dye (MS18) fabricated under an aqueous subphase containing a cadmium ion (Cd2+) and have investigated its thermal behavior by UV-visible and IR absorption spectroscopy in the range from 25 to 250 degrees C with a continuous scan. The results of both UV-visible and IR absorption spectra indicate that temperature-dependent changes in the MS18 aggregation state in the pure MS18 system are closely and mildly linked with the MS18 intramolecular charge transfer and the behavior of the packing, orientation, conformation, and thermal mobility of MS18 hydrocarbon chain, respectively. The J-aggregate in the pure MS18 system dissociates from 25 to 150 degrees C, and the dissociation temperature at 150 degrees C is higher by 50 degrees C than that in the previous MS18- arachidic acid (C20) binary system. The lower dissociation temperature in the binary system originates from the fact that temperature-dependent structural disorder of cadmium arachidate (CdC20), being phase-separated from MS18, has an influence on the dissociation of J-aggregate. From 160 to 180 degrees C, thermally induced blue-shifted bands, caused by the oligomeric MS18 aggregation, appear at around 520 nm in the pure MS18 system by contraries, regardless of the lack of driving force by the melting phenomenon of CdC20. The temperature at which the 520 nm bands occur is in good agreement with the melting point (160 degrees C) of hydrocarbon chain in MS18 with Cd2+, whereas its chromophore part is clearly observed to melt near 205 degrees C by UV-visible spectra. Therefore, it is suggested that the driving force that induces the 520 nm band in the pure MS18 system arises from the partial melting of hydrocarbon chain in MS18 with Cd2+.

Behavior and distribution of 226Ra and 228Ra in the east coast of Peninsular Malaysia marine environment

International Nuclear Information System (INIS)

Nurrul Assyikeen Mohd Jaffary; Zal Uyun Wan Mahmood; Zaharudin Ahmad; Yii, Mei Wo; Kamarozaman Ishak

2010-01-01

The present distributions of 226 Ra, 228 Ra and activity ratios of 228 Ra/ 226 Ra covering the east coast of Peninsular Malaysia were studied. Sediment core samples were collected at 10 identified stations with the thickness of water column between 14 - 72 m depth during the cruise conducted in 2008. Activity concentrations of 226 Ra and 228 Ra in sediment cores of the studied area were in the range of 18.95 ±4.25 Bq/ kg to 46.48 ± 6.41 Bq/ kg dry wt. and 35.50 ± 7.50 Bq/ kg to 77.10 ±11.37 Bq/ kg dry wt., respectively. Meanwhile, the calculated activity ratios of 228 Ra/ 226 Ra were varied mostly 1.48 to 2.24. The finding showed that there has relationships between 226 Ra, 228 Ra and oceanographic parameters which are can be attributed for better understanding of its transport processes and behavior in the east coast of Peninsular Malaysia marine environment. (author)

Zr 2Ir 6B with an eightfold superstructure of the cubic perovskite-like boride ZrIr 3B 0.5: Synthesis, crystal structure and bonding analysis

Science.gov (United States)

Hermus, Martin; Fokwa, Boniface P. T.

2010-04-01

Single phase powder samples and single crystals of Zr 2Ir 6B were successfully synthesized by arc-melting the elements in a water-cooled copper crucible under an argon atmosphere. Superstructure reflections were observed both on powder and on single crystal diffraction data, leading to an eightfold superstructure of ZrIr 3B x phase. The new phase, which has a metallic luster, crystallizes in space group Fm3¯m (no. 225) with the lattice parameters a=7.9903(4) Å, V=510.14(4) Å 3. Its crystal structure was refined on the basis of powder as well as single crystal data. The single crystal refinement converged to R1=0.0239 and w R2=0.0624 for all 88 unique reflections and 6 parameters. Zr 2Ir 6B is isotypic to Ti 2Rh 6B and its structure can be described as a defect double perovskite, A2BB' O6, where the A site is occupied by zirconium, the B site by boron, the O site by iridium but the B' site is vacant, leading to the formation of empty and boron-filled octahedral Ir 6 clusters. According to the result of tight-binding electronic structure calculations, Ir-B and Ir-Zr interactions are mainly responsible for the structural stability of the phase. According to COHP bonding analysis, the strongest bonding occurs for the Ir-B contacts, and the Ir-Ir bonding within the empty clusters is two times stronger than that in the BIr 6 octahedra.

Spectrophotometer-Integrating-Sphere System for Computing Solar Absorptance

Science.gov (United States)

Witte, William G., Jr.; Slemp, Wayne S.; Perry, John E., Jr.

1991-01-01

A commercially available ultraviolet, visible, near-infrared spectrophotometer was modified to utilize an 8-inch-diameter modified Edwards-type integrated sphere. Software was written so that the reflectance spectra could be used to obtain solar absorptance values of 1-inch-diameter specimens. A descriptions of the system, spectral reflectance, and software for calculation of solar absorptance from reflectance data are presented.

Plant phenolics and absorption features in vegetation reflectance spectra near 1.66 μm

Science.gov (United States)

Kokaly, Raymond F.; Skidmore, Andrew K

2015-01-01

Past laboratory and field studies have quantified phenolic substances in vegetative matter from reflectance measurements for understanding plant response to herbivores and insect predation. Past remote sensing studies on phenolics have evaluated crop quality and vegetation patterns caused by bedrock geology and associated variations in soil geochemistry. We examined spectra of pure phenolic compounds, common plant biochemical constituents, dry leaves, fresh leaves, and plant canopies for direct evidence of absorption features attributable to plant phenolics. Using spectral feature analysis with continuum removal, we observed that a narrow feature at 1.66 μm is persistent in spectra of manzanita, sumac, red maple, sugar maple, tea, and other species. This feature was consistent with absorption caused by aromatic C-H bonds in the chemical structure of phenolic compounds and non-hydroxylated aromatics. Because of overlapping absorption by water, the feature was weaker in fresh leaf and canopy spectra compared to dry leaf measurements. Simple linear regressions of feature depth and feature area with polyphenol concentration in tea resulted in high correlations and low errors (% phenol by dry weight) at the dry leaf (r2 = 0.95, RMSE = 1.0%, n = 56), fresh leaf (r2 = 0.79, RMSE = 2.1%, n = 56), and canopy (r2 = 0.78, RMSE = 1.0%, n = 13) levels of measurement. Spectra of leaves, needles, and canopies of big sagebrush and evergreens exhibited a weak absorption feature centered near 1.63 μm, short ward of the phenolic compounds, possibly consistent with terpenes. This study demonstrates that subtle variation in vegetation spectra in the shortwave infrared can directly indicate biochemical constituents and be used to quantify them. Phenolics are of lesser abundance compared to the major plant constituents but, nonetheless, have important plant functions and ecological significance. Additional research is needed to advance our understanding of the

Diffuse Reflectance Spectroscopy of Hidden Objects, Part I: Interpretation of the Reflection-Absorption-Scattering Fractions in Near-Infrared (NIR) Spectra of Polyethylene Films.

Science.gov (United States)

Pomerantsev, Alexey L; Rodionova, Oxana Ye; Skvortsov, Alexej N

2017-08-01

Investigation of a sample covered by an interfering layer is required in many fields, e.g., for process control, biochemical analysis, and many other applications. This study is based on the analysis of spectra collected by near-infrared (NIR) diffuse reflectance spectroscopy. Each spectrum is a composition of a useful, target spectrum and a spectrum of an interfering layer. To recover the target spectrum, we suggest using a new phenomenological approach, which employs the multivariate curve resolution (MCR) method. In general terms, the problem is very complex. We start with a specific problem of analyzing a system, which consists of several layers of polyethylene (PE) film and underlayer samples with known spectral properties. To separate information originating from PE layers and the target, we modify the system versus both the number of the PE layers as well as the reflectance properties of the target sample. We consider that the interfering spectrum of the layer can be modeled using three components, which can be tentatively called transmission, absorption, and scattering contributions. The novelty of our approach is that we do not remove the reflectance and scattering effects from the spectra, but study them in detail aiming to use this information to recover the target spectrum.

RA Research nuclear reactor - Annual report 1987; Istrazivacki nuklearni reaktor RA - Izvestaj o radu za 1987. godinu

Energy Technology Data Exchange (ETDEWEB)

NONE

1987-12-15

Annual report concerning the project 'RA research nuclear reactor' for 1987, financed by the Serbian ministry of science is divided into two parts. First part is concerned with RA reactor operation and maintenance, which is the task of the Division for reactor engineering of the Institute for multidisciplinary studies and RA reactor engineering. Second part deals with radiation protection activities at the RA reactor which is the responsibility of the Institute for radiation protection. Scientific council of the Institute for multidisciplinary studies and RA reactor engineering has stated that this report describes adequately the activity and tasks fulfilled at the RA reactor in 1989. The scope and the quality of the work done were considered successful both concerning the maintenance and reconstruction, as well as radiation protection activities. [Serbo-Croat] Godisnji izvestaj po projektu 'Istrazivacki nuklearni reaktor RA' za 1987. godinu, koji finansira republicka zajednica za nauku SR Srbije po ugovoru br. 3509/1 sastoji se iz dva dela. Prvi deo obuhvata pogon i odrzavanje nuklearnog reaktora RA, sto predstavlja obavezu Odeljenja za reaktorski inzenjering u sastavu OOUR Instituta za multidisciplinarna istrazivanja i inzenjering RA. Drugi deo obuhvata poslove zastite od zracenja na reaktoru RA, sto predstavlja obavezu OOUR Instituta za zastitu od zracenja 'Zastita'. Naucno vece Instituta za multidisciplinarna istrazivanja i inzenjjring RA ocenilo je da sadrzina ovog izvestaja odgovara izvrsenim poslovima na reaktoru RA u 1989. godini. Pozitivno se ocenjuje obim i kvalitet izvrsenih radova kako u pogledu odrzavanja i rekonstrukcije reaktora, tako i u pogledu poslova zastite od zracenja izvrsenih kod njega.

Identification and Quantification of Microplastics in Wastewater Using Focal Plane Array-Based Reflectance Micro-FT-IR Imaging.

Science.gov (United States)

Tagg, Alexander S; Sapp, Melanie; Harrison, Jesse P; Ojeda, Jesús J

2015-06-16

Microplastics (microplastics in these matrices has not been investigated. Although efficient methods for the analysis of microplastics in sediment samples and marine organisms have been published, no methods have been developed for detecting these pollutants within organic-rich wastewater samples. In addition, there is no standardized method for analyzing microplastics isolated from environmental samples. In many cases, part of the identification protocol relies on visual selection before analysis, which is open to bias. In order to address this, a new method for the analysis of microplastics in wastewater was developed. A pretreatment step using 30% hydrogen peroxide (H2O2) was employed to remove biogenic material, and focal plane array (FPA)-based reflectance micro-Fourier-transform (FT-IR) imaging was shown to successfully image and identify different microplastic types (polyethylene, polypropylene, nylon-6, polyvinyl chloride, polystyrene). Microplastic-spiked wastewater samples were used to validate the methodology, resulting in a robust protocol which was nonselective and reproducible (the overall success identification rate was 98.33%). The use of FPA-based micro-FT-IR spectroscopy also provides a considerable reduction in analysis time compared with previous methods, since samples that could take several days to be mapped using a single-element detector can now be imaged in less than 9 h (circular filter with a diameter of 47 mm). This method for identifying and quantifying microplastics in wastewater is likely to provide an essential tool for further research into the pathways by which microplastics enter the environment.

MID-IR LUMINOSITIES AND UV/OPTICAL STAR FORMATION RATES AT z < 1.4

International Nuclear Information System (INIS)

Salim, Samir; Dickinson, Mark; Michael Rich, R.; Charlot, Stephane; Lee, Janice C.; Schiminovich, David; Perez-Gonzalez, Pablo G.; Ashby, Matthew L. N.; Noeske, Kai; Papovich, Casey; Weiner, Benjamin J.; Faber, S. M.; Ivison, Rob J.; Frayer, David T.; Walton, Josiah M.; Chary, Ranga-Ram; Bundy, Kevin; Koekemoer, Anton M.

2009-01-01

Ultraviolet (UV) nonionizing continuum and mid-infrared (IR) emission constitute the basis of two widely used star formation (SF) indicators at intermediate and high redshifts. We study 2430 galaxies with z 10 -10 12 L sun ). We show that the IR luminosity can be estimated from the UV and optical photometry to within a factor of 2, implying that most z IR >10 11 L sun , yet with little current SF. For them a reasonable amount of dust absorption of stellar light (but presumably higher than in nearby early-type galaxies) is sufficient to produce the observed levels of IR, which includes a large contribution from intermediate and old stellar populations. In our sample, which contains very few ultraluminous IR galaxies, optical and X-ray active galactic nuclei do not contribute on average more than ∼50% to the mid-IR luminosity, and we see no evidence for a large population of 'IR excess' galaxies.

L’univers «Japon» romanesque en tant que scénographie dans Stupeur et Tremblement d’Amélie Nothomb. Japonijos visuomenė kaip scenografija Amélie Nothomb romane Baimė ir drebėjimas

Directory of Open Access Journals (Sweden)

Kyoko Koma

2009-01-01

Full Text Available Japonijoje gimusi ir ten vaikystę praleidusi belgų kilmės rašytoja Amélie Nothomb, remdamasi savo japoniška patirtimi, išleido keletą romanų, tarp jų – Baimę ir drebėjimą (Stupeur et tremblemet, 1999. Asmeninė rašytojos gyvenimo Japonijoje patirtis, jos romano pasakotojas ir personažų vardai skatina tam tikrą skaitytojų recepciją – skaityti šį romaną kaip tikrovišką pasakojimą. Straipsnyje teigiama, kad romano pasakotoja Amelija, vartodama tokius vie­našališkus žodžius ir posakius kaip antai stereotipai ir išankstinės nuomonės (idées reçues, konstruoja stereotipišką ir ironiškai konotuotą Japonijos visuo­menės paveikslą, kurį skaitytojai interpretuoja kaip scenografiją. Šioje scenografijoje pasakotojos Ame­lijos patirtis pateikiama kaip būdinga tik Japonijos visuomenei.

Photothermal microfluidic cantilever deflection spectroscopy reflecting clustering mechanism of ethanol water mixtures

Science.gov (United States)

Ghoraishi, Maryam; Hawk, John; Thundat, Thomas

Aqueous mixture of alcohol is a typical prototype for biomolecules, micelle formation, and structural stability of proteins. Therefore, Short chain alcohols such as EtOH have been used as a simple model for understanding of more complex aqueous biomolecules. Here we study vibrational energy peaks of EtOH water binary mixtures using micromechanical calorimetric spectroscopy using bimaterial microfluidic cantilevers (BMC). The IR spectra of EtOH-water are experimentally collected employing a BMC as concentration of EtOH changes from 20-100 wt%. As concentration of EtOH varies in the mixture, considerable shifts in the wavenumber at IR absorption peak maxima are reported. The experimentally measured shifts in the wavenumber at IR absorption peak maxima are related to changes in dipole moment (μ) of EtOH at different concentration. The relationship between IR absorption wavenumber for both anti and gauche conformers of EtOH, and inverse dipole moment, 1/ μ, of EtOH at different concentrations follows a power law dependence. Our technique offers a platform to investigate dipole effect on molecular vibrations of mixtures in confined picoliter volumes, previously unexplored with other analytical techniques due to limitations of volume under study.

Regulations for RA reactor operation; Propisi nuklearnog reaktora 'RA'

Energy Technology Data Exchange (ETDEWEB)

NONE

1980-09-15

Regulations for RA reactor operation are written in accordance with the legal regulations defined by the Law about radiation protection and related legal acts, as well as technical standards according to the IAEA recommendations. The contents of this book include: fundamental data about the reactor; legal regulations for reactor operation; organizational scheme for reactor operation; general and detailed instructions for operation, behaviour in the reactor building, performing experiments; operating rules for operation under steady state and accidental conditions. [Serbo-Croat] Propisi o radu nuklearnog reaktora RA pisani su tako da svi zakonski propisi definisani 'Zakonom o zastiti od jonizujuceg zracenja' i pratecim propisima (devet pravilnika) kao i tehnicke norme prema preporukama MAAE budu postovani u punoj meri pri radu reaktora. Sadrzaj ove knjige obuhvata: osnovne podatke o reaktoru; zakonske propise; organizaciju rada reaktora RA; opste propise o rezimu rada, kretanju u zgradi reaktora, izvodjenju eksperimenata; pogonske propise za rad u normalnom rezimu i u slucaju udesa.

Magnetic feature and near-infrared absorption of a [Pt(mnt)2]-based H-bond supramolecular crystal

International Nuclear Information System (INIS)

Li, Cui-Ping; Nie, Li; Pei, Wen-Bo; Li, Li; Tian, Zheng-Fang; Liu, Jian-Lan; Gao, Xu-Sheng; Ren, Xiao-Ming

2016-01-01

A new salt [H 2 DABCO][Pt(mnt) 2 ] 2 (1) (mnt 2- =maleonitriledithiolate and H 2 DABCO 2+ is diprotonated 1,4-diazabicyclo[2.2.2]octane) has been synthesized; its crystal structure, magnetic and near-IR absorption properties have been investigated. Two different [Pt(mnt) 2 ] - anions form the strong π-dimers, labeled as Pt(1)-dimer and Pt(2)-dimer, with quite shorter Pt…Pt and S…S distances and molecular plane-to-plane distance (<3.5 Å) within a dimer. The [Pt(mnt) 2 ] 2 2- π-dimers are connected through the cations in the strong H-bond manner to form three-dimensional H-bond supramolecular crystal. The salt shows weak paramagnetism in 1.99–300 K and this is due to the existence of strong antiferromagnetic coupling within a π-dimer. In addition, a small thermal hysteresis loop is observed at ca. 120 K, indicating that a phase transition probably occurs that is further confirmed by variable-temperature IR spectra. Another fascinating functionality of 1 is the intense near-IR absorption in the region of 750–2500 nm, and this near-IR absorption feature makes it to be a promising optical material. - Graphical abstract: A H-bond supramolecular crystal of [H 2 DABCO][Pt(mnt) 2 ] 2 shows a magnetic phase transition at ca. 120 K with sizable thermal hysteresis loop and intense near-IR absorption in the region of 750–2500 nm.

Low-Absorption Liquid Crystals for Infrared Beam Steering

Science.gov (United States)

2015-09-30

controlled the curing temperature at 0oC to obtain small domain size and fast response time is expected. Here, a UV light-emitting diode ( LED ) lamp ...absorption; def.=deformation; w =weak absorption; v.=variable intensity) [B. D. Mistry, A Handbook of Spectroscopic Data: Chemistry- UV , IR, PMR, CNMR and...contributed by the core structure and terminal groups. Due to UV instability of double bonds and carbon-carbon triple bonds, conjugated phenyl rings have

Ba(Ra)SO4 species flotation for decontamination of Ra(II) residual solution

International Nuclear Information System (INIS)

Stoica, Ligia; Catuneanu, Rodica; Filip, Gheorghe

1993-01-01

The paper presents the results of the research performed on Ra(II) separation from complex composition solutions in a HCO 3 - /CO 3 2- buffer system by Ba(Ra)SO 4 precipitation followed by flotation. The collector selection was done by electrokinetic potential determinations. The optimum concentrations of precipitation-flocculation reagents were established on the basis of the experimental data obtained for synthetic solutions having the same Ra(II) activity, namely 20 pCi/l. (authors)

New infrared observations of IRS 1, IRS 3, and the adjacent nebula in the OMC-2 cluster

International Nuclear Information System (INIS)

Pendelton, Y.; Werner, M.; Dinerstein, H.

1984-01-01

Recent reports show that near infrared reflection nebulae are often observed around embedded protostellar objects. New observations are here reported of the infrared cluster of low luminosity protostars in Orion Molecular Cloud 2 (OMC2). It has been determined that the asymmetric distribution of the extended emission seen about IRS1 is in fact another infrared reflection nebula. Observations of near infrared polarimetry, photometry, and spectrophotometry were carried out at the NASA Infrared Telescope Facility October 1982 and January 1983. (author)

Transfer of 226Ra, 228Ra, 210Pb and 210Po in aquatic organisms and food chain

International Nuclear Information System (INIS)

Yang Xiaotong; Weng Detong; Chen Wenyin; Chen Xiuyun; Chen Jixi; Zhao Shimin

1998-01-01

Objective: To find out the transfer regularities of 226 Ra, 228 Ra, 210 Pb and 210 Po, which are natural radionuclides in the aquatic organisms and food chain. Methods: Large amount of breed of representative aquatic products and their living waters and sediments were collected and treated according to routine experimental procedures. The contents of 226 Ra, 228 Ra, 210 Pb and 210 Po were detected in each sample. Measured data were analyzed statistically and pairwise comparisons were made to determine the differences between groups. Results: 226 Ra, 228 Ra and 210 Pb were mainly deposited in the bones (or shells), their concentration factors (CF) ranged from 10 2 to 10 3 ; the CF ranged only from 10 0 to 10 2 in the flesh. 210 Po was mainly deposited in the soft tissues, CF ranged from 10 2 to 10 4 ; especially in the stomachs and intestines of fishes, the value reached 10 4 . The cooking process did not impinge significantly on the transfer of 226 Ra, 228 Ra and 210 Pb in the food chain (P>0.05), but did significantly influence the transfer of 210 Po, especially in the freshwater fishes and shrimps. Paired comparison test of the activities between raw flesh and cooked flesh showed very significant difference (P 226 Ra, 228 Ra, 210 Pb and 210 Po. Even though the bones (or shells) of aquatic organisms contained relatively higher levels of 226 Ra, 228 Ra and 210 Pb, the cooking process does not significantly increase the radioactive contents in the foodstuffs. However, the cooking process does significantly influence the transfer of 210 Po. It does significantly increase the content of 210 Po in foodstuffs

Synchrotron far-IR RAIRS studies of interfaces created by polyfunctional organic molecules at defined metal surfaces

International Nuclear Information System (INIS)

Raval, R.; Williams, J.; Roberts, A.J.; Nunney, T.S.; Surman, M.

1998-01-01

Far-IR Reflection Absorption Infrared Spectroscopy (RAIRS) has been used to probe sub monolayers and multilayers of polyfunctional organic ad layers deposited under clean controlled conditions on small-area single-crystal surfaces, using the newly commissioned Daresbury 13.3 far-IR synchrotron beamline. It's shown that the current performance of the beamline allows to monitor fractions of monolayers of formate species on Cu(110), formed at 300 K from the deprotonation of formic acid. Two distinct vCu-O vibrations are observed for coverages up to 0.25 monolayer. The paper attributes the two bands to at least two chemically distinct species, each possessing a local site symmetry of C 2v and bonded to the metal surface via the two oxygen atoms. The two types of formate species are thought to arise from local density fluctuations in formate coverage across the ad layer which leads to local changes in the Cu-O bond. In additions, it's reported far-IR RAIRS spectra of bio molecule/metal interfaces created by depositing thin films (3-10 layers) of the chiral amino-acid, L-methionine, on Cu(110) at 300 K. The multilayer spectra closely resemble the far-IR spectra obtained from crystalline L-methionine, suggesting that the thin layer consists of the zwitterionic species. These thin bio films are stable on the surface to >330 K. No growth of metal-ligand vibrations in the multilayer phase is observed, demonstrating that corrosive chemisorption processes that create Cu-methionine complexes in the multilayer by leaching of surface Cu atoms do not occur in these conditions

Photoacoustic Experimental System to Confirm Infrared Absorption Due to Greenhouse Gases

Science.gov (United States)

Kaneko, Fumitoshi; Monjushiro, Hideaki; Nishiyama, Masayoshi; Kasai, Toshio; Harris, Harold H.

2010-01-01

An experimental system for detecting infrared absorption using the photoacoustic (PA) effect is described. It is aimed for use at high-school level to illustrate the difference in infrared (IR) absorption among the gases contained in the atmosphere in connection with the greenhouse effect. The experimental system can be built with readily…

Ultimate realistic losses of ZrF/sub 4/ based IR fibres

International Nuclear Information System (INIS)

France, P.W.; Carter, S.F.; Moore, M.W.; Williams, J.R.

1986-01-01

An estimation has been made of the minimum loss that might be expected in ZrF/sub 4/ based IR fibre taking into account extrinsic absorption losses as well as the intrinsic loss mechanisms associated with the IR edge and Rayleigh scattering. The results suggest that an overall loss of approximately 0.03 dB/km might be expected at 2.56 μm, a factor of three higher than the intrinsic loss and a factor of seven lower than overall loss in a typical silica fibre

A Multi-Band Analytical Algorithm for Deriving Absorption and Backscattering Coefficients from Remote-Sensing Reflectance of Optically Deep Waters

Science.gov (United States)

Lee, Zhong-Ping; Carder, Kendall L.

2001-01-01

A multi-band analytical (MBA) algorithm is developed to retrieve absorption and backscattering coefficients for optically deep waters, which can be applied to data from past and current satellite sensors, as well as data from hyperspectral sensors. This MBA algorithm applies a remote-sensing reflectance model derived from the Radiative Transfer Equation, and values of absorption and backscattering coefficients are analytically calculated from values of remote-sensing reflectance. There are only limited empirical relationships involved in the algorithm, which implies that this MBA algorithm could be applied to a wide dynamic range of waters. Applying the algorithm to a simulated non-"Case 1" data set, which has no relation to the development of the algorithm, the percentage error for the total absorption coefficient at 440 nm a (sub 440) is approximately 12% for a range of 0.012 - 2.1 per meter (approximately 6% for a (sub 440) less than approximately 0.3 per meter), while a traditional band-ratio approach returns a percentage error of approximately 30%. Applying it to a field data set ranging from 0.025 to 2.0 per meter, the result for a (sub 440) is very close to that using a full spectrum optimization technique (9.6% difference). Compared to the optimization approach, the MBA algorithm cuts the computation time dramatically with only a small sacrifice in accuracy, making it suitable for processing large data sets such as satellite images. Significant improvements over empirical algorithms have also been achieved in retrieving the optical properties of optically deep waters.

Origin of absorption peaks in reflection loss spectrum in Ku- frequency band of Co-Zr substituted strontium hexaferrites prepared using sucrose precursor

Energy Technology Data Exchange (ETDEWEB)

Narang, Sukhleen Bindra, E-mail: sukhleen2@yahoo.com [Department of Electronics Technology, Guru Nanak Dev University, Amritsar (India); Pubby, Kunal, E-mail: kunalpubby02@gmail.com [Department of Electronics Technology, Guru Nanak Dev University, Amritsar (India); Chawla, S.K., E-mail: sschawla118@gmail.com [Department of Chemistry, Centre for Advanced Studies-I, Guru Nanak Dev University, Amritsar (India); Kaur, Prabhjyot, E-mail: prabhjyot.2525@gmail.com [Department of Chemistry, Centre for Advanced Studies-I, Guru Nanak Dev University, Amritsar (India)

2017-03-15

This study presents the detailed explanation of the factors, contributing towards the absorption peaks in reflection loss spectrum of hexaferrites. Cobalt-Zirconium substituted strontium hexaferrites, synthesized using sucrose precursor sol-gel technique, were analyzed in 12.4–18 GHz frequency range. The concepts of impedance matching through quarter wavelength condition, complex thickness, dielectric phase angle and attenuation constant have been used to determine the location as well as intensity of absorption peaks. This study also demonstrates the potential application of three compositions of this series with doping content (x)==0.0, 0.6 and 0.8 as an effective microwave absorbers in Ku-frequency band. - Highlights: • EM analysis of Sr Hexaferrites in Ku-band. • Factors towards absorption peak intensity & location.

Žurnalisto profesinės vertybės: normatyvinis ir praktinis požiūriai

OpenAIRE

Mažylytė, Audronė

2008-01-01

Pastaruoju metu vis dažniau kalbama apie neskaidrią žiniasklaidą, jos komercialėjimą, mažėjantį visuomenės pasitikėjimą ja, taip pat pasigirsta pranešimų apie profesinei etikai nusižengusius žurnalistus. Vis garsiau prabylama ir apie iš��ūkius pačiai žurnalisto profesijai, nes dėl technologijų evoliucijos, interneto teikiamų galimybių plečiasi „žurnalisto“ samprata – dabar kone kiekvienas rašantis gali publikuoti savo straipsnius internetinėje erdvėje ir vadintis žurnalistu. Todėl galima teig...

First 226Ra- 210Pb dating of a young speleothem

Science.gov (United States)

Condomines, M.; Rihs, S.

2006-10-01

Whereas the method based on the decrease of excess 210Pb has already been used to date young (Age determination of recent cave deposits using excess 210Pb — A new technique, Geophys. Res. Lett. 20 (1993) 603-606.]), this paper presents the first dating of a speleothem through the 226Ra- 210Pb method. Dating of a young hydrothermal stalagmite from the Mt Cornadore cave (St Nectaire, French Massif Central) was made possible by the high 226Ra and negligible 210Pb contents of such carbonates, formed by precipitation from CO 2-rich thermal waters. ( 210Pb/ 226Ra) ratios regularly increase with depth along the axis of the 33 cm long stalagmite. The age-depth relationship can be interpreted by two main phases of growth, with high but variable axial growth rates of 5.3 mm/yr from 1909 to 1967, and 2.6 mm/yr from 1967 to 1989 (alternatively, the oldest phase can be subdivided in three episodes with growth rates varying from 2 to 7 mm/yr). Thin-section examination reveals the presence of numerous laminae, indicating infra-annual variations. We suggest that this fine layered structure might reflect short-term fluctuations in drip waters, possibly induced by near-surface mixing between thermal and ground waters, and ultimately linked to the pluviometry. A detailed examination of this laminated structure combined with 226Ra- 210Pb dating could thus provide a high-resolution record of local paleohydrological fluctuations.

Comparison of Fiber Optic and Conduit Attenuated Total Reflection (ATR) Fourier Transform Infrared (FT-IR) Setup for In-Line Fermentation Monitoring.

Science.gov (United States)

Koch, Cosima; Posch, Andreas E; Herwig, Christoph; Lendl, Bernhard

2016-12-01

The performance of a fiber optic and an optical conduit in-line attenuated total reflection mid-infrared (IR) probe during in situ monitoring of Penicillium chrysogenum fermentation were compared. The fiber optic probe was connected to a sealed, portable, Fourier transform infrared (FT-IR) process spectrometer via a plug-and-play interface. The optical conduit, on the other hand, was connected to a FT-IR process spectrometer via a knuckled probe with mirrors that had to be adjusted prior to each fermentation, which were purged with dry air. Penicillin V (PenV) and its precursor phenoxyacetic acid (POX) concentrations were determined by online high-performance liquid chromatography and the obtained concentrations were used as reference to build partial least squares regression models. Cross-validated root-mean-square errors of prediction were found to be 0.2 g L -1 (POX) and 0.19 g L -1 (PenV) for the fiber optic setup and 0.17 g L -1 (both POX and PenV) for the conduit setup. Higher noise-levels and spectrum-to-spectrum variations of the fiber optic setup lead to higher noise of estimated (i.e., unknown) POX and PenV concentrations than was found for the conduit setup. It seems that trade-off has to be made between ease of handling (fiber optic setup) and measurement accuracy (optical conduit setup) when choosing one of these systems for bioprocess monitoring. © The Author(s) 2016.

Assessment of 226Ra, 228Ra and 40K contents in the Egyptian bottled natural water

International Nuclear Information System (INIS)

El-Afifi, E.M.; Hilal, M.A.; Khalifa, S.M.; Aly, H.F.

2004-01-01

The activity concentrations of 2 26Ra, 2 28Ra and 4 0 and k in different brands of the bottled egyptian natural water of different origins obtained from four regions, have been analyzed nondestructively by gamma- ray spectrometry. The study covers nine brands of natural water commonly used mainly for drinking in egypt. The results showed, concentrations up to 184, 156 and 1700 mBq I - 1 for 2 26Ra, 2 28Ra and 4 0K, respectively, in one brand of the natural water from water from Siwa oasis. Whereas, lower activity concentrations of 2 26Ra and 2 28Ra were found in one brand of these natural waters from El sadat region. The activity concentration of 4 0K was found to be in the background range in the brands from El sadat, kafr El arbein and beilbeis regions. The committed effective doses reached 1.9 x 10 - 2 m Sy Y - 1 for ingestion of 2 26Ra and 2 28Ra for one liter per day, respectively, which are lower than the standard permissible limit by the WHO and IAEA. However, it is recommended to moderate drinking of bottled natural water to avoid the accumulation effect of radioactive nuclides especially radium

Quantum interference between multi photon absorption pathways in organic solid

International Nuclear Information System (INIS)

Rebane, A.; Christensson, N.; Drobizhev, M.; Stepanenko, Y.; Spangler, C.W.

2007-01-01

We demonstrate spatial interference fringe pattern by simultaneous one- and three-photon absorption of UV and near-IR femtosecond pulses in thin film organic solid at room temperature. We use organic dendrimers that are specially designed to have strong fluorescence and very large three-photon absorption cross-section. High fringe visibility allows the quantum interference to be observed by eye

Characterization of atmospheric aerosols using Synchroton radiation total reflection X-ray fluorescence and Fe K-edge total reflection X-ray fluorescence-X-ray absorption near-edge structure

Energy Technology Data Exchange (ETDEWEB)

Fittschen, U.E.A. [Department of Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany)], E-mail: ursula.fittschen@chemie.uni-hamburg.de; Meirer, F. [Atominstitut, Vienna University of Technology, Stadionallee 2, 1020 Wien (Austria)], E-mail: fmeirer@ati.ac.at; Streli, C. [Atominstitut, Vienna University of Technology, Stadionallee 2, 1020 Wien (Austria)], E-mail: streli@ati.ac.at; Wobrauschek, P. [Atominstitut, Vienna University of Technology, Stadionallee 2, 1020 Wien (Austria)], E-mail: wobi@ati.ac.at; Thiele, J. [Department of Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany)], E-mail: Julian.Thiele@gmx.de; Falkenberg, G. [Hamburger Synchrotronstrahlungslabor at Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22603 Hamburg (Germany)], E-mail: falkenbe@mail.desy.de; Pepponi, G. [ITC-irst, Via Sommarive 18, 38050 Povo (Trento) (Italy)], E-mail: pepponi@itc.it

2008-12-15

In this study a new procedure using Synchrotron total reflection X-ray fluorescence (SR-TXRF) to characterize elemental amounts in atmospheric aerosols down to particle sizes of 0.015 um is presented. The procedure was thoroughly evaluated regarding bounce off effects and blank values. Additionally the potential of total reflection X-ray fluorescence-X-ray absorption near edge structure (SR-TXRF-XANES) for speciation of FeII/III down to amounts of 34 pg in aerosols which were collected for 1 h is shown. The aerosols were collected in the city of Hamburg with a low pressure Berner impactor on Si carriers covered with silicone over time periods of 60 and 20 min each. The particles were collected in four and ten size fractions of 10.0-8.0 {mu}m, 8.0-2.0 {mu}m, 2.0-0.13 {mu}m 0.13-0.015 {mu}m (aerodynamic particle size) and 15-30 nm, 30-60 nm, 60-130 nm, 130-250 nm, 250-500 nm, 0.5-1 {mu}m, 1-2 {mu}m, 2-4 {mu}m, 4-8 {mu}m, 8-16 {mu}m. Prior to the sampling 'bounce off' effects on Silicone and Vaseline coated Si carriers were studied with total reflection X-ray fluorescence. According to the results silicone coated carriers were chosen for the analysis. Additionally, blank levels originating from the sampling device and the calibration procedure were studied. Blank levels of Fe corresponded to 1-10% of Fe in the aerosol samples. Blank levels stemming from the internal standard were found to be negligible. The results from the Synchroton radiation total reflection X-ray fluorescence analysis of the aerosols showed that 20 min of sampling time gave still enough sample material for elemental determination of most elements. For the determination of the oxidation state of Fe in the aerosols different Fe salts were prepared as a reference from suspensions in isopropanol. The results from the Fe K-edge Synchroton radiation total reflection X-ray fluorescence-X-ray absorption near-edge structure analysis of the aerosol samples showed that mainly Fe(III) was present in

Characterization of atmospheric aerosols using Synchroton radiation total reflection X-ray fluorescence and Fe K-edge total reflection X-ray fluorescence-X-ray absorption near-edge structure

International Nuclear Information System (INIS)

Fittschen, U.E.A.; Meirer, F.; Streli, C.; Wobrauschek, P.; Thiele, J.; Falkenberg, G.; Pepponi, G.

2008-01-01

In this study a new procedure using Synchrotron total reflection X-ray fluorescence (SR-TXRF) to characterize elemental amounts in atmospheric aerosols down to particle sizes of 0.015 um is presented. The procedure was thoroughly evaluated regarding bounce off effects and blank values. Additionally the potential of total reflection X-ray fluorescence-X-ray absorption near edge structure (SR-TXRF-XANES) for speciation of FeII/III down to amounts of 34 pg in aerosols which were collected for 1 h is shown. The aerosols were collected in the city of Hamburg with a low pressure Berner impactor on Si carriers covered with silicone over time periods of 60 and 20 min each. The particles were collected in four and ten size fractions of 10.0-8.0 μm, 8.0-2.0 μm, 2.0-0.13 μm 0.13-0.015 μm (aerodynamic particle size) and 15-30 nm, 30-60 nm, 60-130 nm, 130-250 nm, 250-500 nm, 0.5-1 μm, 1-2 μm, 2-4 μm, 4-8 μm, 8-16 μm. Prior to the sampling 'bounce off' effects on Silicone and Vaseline coated Si carriers were studied with total reflection X-ray fluorescence. According to the results silicone coated carriers were chosen for the analysis. Additionally, blank levels originating from the sampling device and the calibration procedure were studied. Blank levels of Fe corresponded to 1-10% of Fe in the aerosol samples. Blank levels stemming from the internal standard were found to be negligible. The results from the Synchroton radiation total reflection X-ray fluorescence analysis of the aerosols showed that 20 min of sampling time gave still enough sample material for elemental determination of most elements. For the determination of the oxidation state of Fe in the aerosols different Fe salts were prepared as a reference from suspensions in isopropanol. The results from the Fe K-edge Synchroton radiation total reflection X-ray fluorescence-X-ray absorption near-edge structure analysis of the aerosol samples showed that mainly Fe(III) was present in all particle size fractions

Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Spectroscopy as an Analytical Method to Investigate the Secondary Structure of a Model Protein Embedded in Solid Lipid Matrices.

Science.gov (United States)

Zeeshan, Farrukh; Tabbassum, Misbah; Jorgensen, Lene; Medlicott, Natalie J

2018-02-01

Protein drugs may encounter conformational perturbations during the formulation processing of lipid-based solid dosage forms. In aqueous protein solutions, attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy can investigate these conformational changes following the subtraction of spectral interference of solvent with protein amide I bands. However, in solid dosage forms, the possible spectral contribution of lipid carriers to protein amide I band may be an obstacle to determine conformational alterations. The objective of this study was to develop an ATR FT-IR spectroscopic method for the analysis of protein secondary structure embedded in solid lipid matrices. Bovine serum albumin (BSA) was chosen as a model protein, while Precirol AT05 (glycerol palmitostearate, melting point 58 ℃) was employed as the model lipid matrix. Bovine serum albumin was incorporated into lipid using physical mixing, melting and mixing, or wet granulation mixing methods. Attenuated total reflection FT-IR spectroscopy and size exclusion chromatography (SEC) were performed for the analysis of BSA secondary structure and its dissolution in aqueous media, respectively. The results showed significant interference of Precirol ATO5 with BSA amide I band which was subtracted up to 90% w/w lipid content to analyze BSA secondary structure. In addition, ATR FT-IR spectroscopy also detected thermally denatured BSA solid alone and in the presence of lipid matrix indicating its suitability for the detection of denatured protein solids in lipid matrices. Despite being in the solid state, conformational changes occurred to BSA upon incorporation into solid lipid matrices. However, the extent of these conformational alterations was found to be dependent on the mixing method employed as indicated by area overlap calculations. For instance, the melting and mixing method imparted negligible effect on BSA secondary structure, whereas the wet granulation mixing method promoted

228Ra and 226Ra measurement on a BaSO4 co-precipitation source

International Nuclear Information System (INIS)

Medley, Peter; Martin, Paul; Bollhöfer, Andreas; Parry, David

2015-01-01

One of the most commonly-used methods for determination of 226 Ra, particularly in water samples, utilises co-precipitation of Ra with BaSO 4 , followed by microfiltration to produce a source for alpha counting. This paper describes two extensions to BaSO 4 co-precipitation methods which enable determination of 228 Ra using the same source. The adaptations presented here do not introduce any contaminants that will affect the separation of radium or alpha counting for 226 Ra, and can be used for re-analysis of already existing sources prepared by BaSO 4 co-precipitation. The first adaptation uses detection of 228 Ac on the source by gamma spectrometry. The detection efficiency is high, allowing analysis of water samples at sufficiently low activity to be suitable in testing for compliance with drinking water quality standards. As 228 Ac grows in quickly, taking less than 2 days to reach equilibrium with the 228 Ra parent, this can also be useful in radiological emergency response situations. The second adaptation incorporates a method for the digestion of BaSO 4 sources, allowing separation of thorium and subsequent determination of 228 Th activity. Although ingrowth periods for 228 Th can be lengthy, very low detection limits for 228 Ra can be achieved with this technique. - Highlights: • We developed two methods for 228 Ra measurement on Ba(Ra)SO 4 co-precipitation sources. • Measurement by gamma spectrometry using the daughter 228 Ac is rapid. • Detection limits are suitable for assessment of drinking water quality. • The second approach uses alpha spectrometry on a separated Th fraction. • This is more sensitive than gamma spectrometry after an ingrowth period greater than about 1 month

Development of a two-wavelength IR laser absorption diagnostic for propene and ethylene

Science.gov (United States)

Parise, T. C.; Davidson, D. F.; Hanson, R. K.

2018-05-01

A two-wavelength infrared laser absorption diagnostic for non-intrusive, simultaneous quantitative measurement of propene and ethylene was developed. To this end, measurements of absorption cross sections of propene and potential interfering species at 10.958 µm were acquired at high-temperatures. When used in conjunction with existing absorption cross-section measurements of ethylene and other species at 10.532 µm, a two-wavelength diagnostic was developed to simultaneously measure propene and ethylene, the two small alkenes found to generally dominate the final decomposition products of many fuel hydrocarbon pyrolysis systems. Measurements of these two species is demonstrated using this two-wavelength diagnostic scheme for propene decomposition between 1360 and 1710 K.

Humora stilu un apmierinātības ar darbu dzimumatšķirības

OpenAIRE

Ozoliņa, Diāna

2017-01-01

Pētījuma mērķis bija izpētīt, vai un kā ar apmierinātību ar darbu saistīti dažādi humora stili, vērtējot sakarības un atšķirības sieviešu un vīriešu izlasē. Pētījumā piedalījās 122 respondenti vecumā no 16-60 gadiem, no kuriem 65% dalībnieku ir sievietes, 35% ir vīrieši. Respondenti elektroniskā veidā aizpildīja Demogrāfisko datu aptauju, Humora stilu aptauju (Humor Style Questionnaire, R. Martin, et al, 2003, adaptācija latviešu valodā I. Stokenberga, 2004), kas mēra četrus humora stilus (b...

Simultaneous determination of Ra-226, Ra-228 and Pb-210 using a successive coprecipitations techniques

International Nuclear Information System (INIS)

Vilhena Schayer Sabino, C. de; Kastner, S.M.S.; Amaral, A.M.

1990-01-01

Several techniques for determination of Ra-226, Ra228 and Pb-210. were developed and used in routine at CDTN in the laboratories of radiochemistry. The matrixes were: water and industrial wastes. Some problems of these techniques were the time spent for analyses and chemical separations, interferents, among others. Now-a-days the method in routine developed here is the one of successive coprecipitations, followed α and β countings of the Ra-226 and Ra-228 daughters. This method is based on coprecipitation, purification of barium radium sulfate with EDTA in acetic solution. Lead is dissolved, radium remains precipitated and suffers a new purification and the time for growing of their daughters is waited to be performed the simultaneous α and β countings for Ra-226 and Ra-228 determination. Pb-210 is analyzed in the floating of the first purification with a carrier of bismuth, and the time for Bi-210 growing is waited. Then it is precipitated as hydroxid, purified as phosphate and the β counting of Bi-210 is done. (author) [pt

ZnIr2O4: An efficient photocatalyst with Rashba splitting

KAUST Repository

Singh, Nirpendra; Schwingenschlö gl, Udo

2013-01-01

spin splitting of 220 meV Å. The valence band edge potential is 2.89 V against the standard hydrogen electrode, which is sufficient for photocatalytic water oxidation and pollutant degradation. The optical absorption of S-doped ZnIr2O4 is strongly

Characterization and identification of microorganisms by FT-IR microspectrometry

Science.gov (United States)

Ngo-Thi, N. A.; Kirschner, C.; Naumann, D.

2003-12-01

We report on a novel FT-IR approach for microbial characterization/identification based on a light microscope coupled to an infrared spectrometer which offers the possibility to acquire IR-spectra of microcolonies containing only few hundred cells. Microcolony samples suitable for FT-IR microspectroscopic measurements were obtained by a replica technique with a stamping device that transfers spatially accurate cells of microcolonies growing on solid culture plates to a special, IR-transparent or reflecting stamping plate. High quality spectra could be recorded either by applying the transmission/absorbance or the reflectance/absorbance mode of the infrared microscope. Signal to noise ratios higher than 1000 were obtained for microcolonies as small as 40 μm in diameter. Reproducibility levels were established that allowed species and strain identification. The differentiation and classification capacity of the FT-IR microscopic technique was tested for different selected microorganisms. Cluster and factor analysis methods were used to evaluate the complex spectral data. Excellent discrimination between bacteria and yeasts, and at the same time Gram-negative and Gram-positive bacterial strains was obtained. Twenty-two selected strains of different species within the genus Staphylococcus were repetitively measured and could be grouped into correct species cluster. Moreover, the results indicated that the method allows also identifications at the subspecies level. Additionally, the new approach allowed spectral mapping analysis of single colonies which provided spatially resolved characterization of growth heterogeneity within complex microbial populations such as colonies.

Reviewing History and IR Journals : Academic Publication Practices and Dominance in World Society

NARCIS (Netherlands)

Duijvendak, Maarten; de Wilde, J.H.

2016-01-01

1 Reviewing History and IR Journals: Academic Publication Practices and dominance in World Society Maarten Duijvendak & Jaap de Wilde Groningen, 2016 This article reflects on analyses of academic History journals and International Relations (IR) journals conducted by students in our Research

RA Research reactor, Annual report 1988

International Nuclear Information System (INIS)

Sotic, O.

1988-12-01

Annual report concerning the project 'RA research nuclear reactor' for 1989, financed by the Serbian ministry of science is divided into two parts. First part is concerned with RA reactor operation and maintenance, which is the task of the Division for reactor engineering of the Institute for multidisciplinary studies and RA reactor engineering. Second part deals with radiation protection activities at the RA reactor which is the responsibility of the Institute for radiation protection. Scientific council of the Institute for multidisciplinary studies and RA reactor engineering has stated that this report describes adequately the activity and tasks fulfilled at the RA reactor in 1989. The scope and the quality of the work done were considered successful both concerning the maintenance and reconstruction, as well as radiation protection activities [sr

226Ra and 228Ra activities associated with agricultural drainage ponds and wetland ponds in the Kankakee Watershed, Illinois-Indiana, USA

International Nuclear Information System (INIS)

Sidle, W.C.; Shanklin, D.; Lee, P.Y.; Roose, D.L.

2001-01-01

Background radioactivity is elevated in many agricultural drainage ponds and also constructed wetland ponds in the Kankakee watershed. During 1995-1999, gross-α and -β activities were measured up to 455 and 1650 mBq L -1 , respectively. 226 Ra and 228 Ra averaged 139 and 192 mBq L -1 in controlled drainage ponds compared to 53 and 58 mBq L -1 for 226 Ra and 228 Ra, respectively, in native wetland ponds. Analyses of applied ammonium phosphate fertilizers near both native and controlled ponds indicate comparable 226 Ra/ 228 Ra and 228 Ra/ 232 Th activity ratios with only the surface waters in the controlled ponds. For example, 226 Ra/ 228 Ra activity ratios in controlled ponds ranged from 0.79 to 0.91 and group with a local fertilizer batch containing FL phosphate compounds with 226 Ra/ 228 Ra activity ratios of 0.83-1.04. Local soils of the Kankakee watershed have 226 Ra/ 228 Ra activity ratios of 0.54-0.70. Calculated Ra fluxes of waters, in drainage ditches associated with these controlled ponds, for 226 Ra ranged from 0.77 to 9.00 mBq cm -2 d -1 and for 228 Ra ranged from 1.22 to 8.43 mBq cm -2 d -1 . Ra activity gradients were measured beneath these controlled ponds both in agricultural landscapes and in constructed wetlands, all being associated with drainage ditches. Ra had infiltrated to the local water table but was below regulatory maximum contaminant limits. Still, measurable Ra activity was measured downgradient of even the constructed wetlands in the Kankakee watershed, suggesting that the attenuation of Ra was low. However, no Ra excess was observed in the riparian zone or the Kankakee River downgradient of the native wetland ponds

Third-harmonic generation in silicon and photonic crystals of macroporous silicon in the spectral intermediate-IR range; Erzeugung der Dritten Harmonischen in Silizium und Photonischen Kristallen aus makroporoesem Silizium im spektralen mittleren IR-Bereich

Energy Technology Data Exchange (ETDEWEB)

Mitzschke, Kerstin

2007-11-01

Nonlinear optical spectroscopy is a powerful method to study surface or bulk properties of condensed matter. In centrosymmetric materials like silicon even order nonlinear optical processes are forbidden. Besides self-focussing or self phase modulation third-harmonic-generation (THG) is the simplest process that can be studied. This work demonstrates that THG is a adapted non-contact and non-invasive optical method to get information about bulk structures of silicon and Photonic crystals (PC), consisting of silicon. Until now most studies are done in the visible spectral range being limited by the linear absorption losses. So the extension of THG to the IR spectral range is extremely useful. This will allow the investigation of Photonic Crystals, where frequencies near a photonic bandgap are of special interest. 2D- photonic structures under investigation were fabricated via photoelectrochemical etching of the Si (100) wafer (thickness 500 {mu}m) receiving square and hexagonal arranged pores. The typical periodicity of the structures used is 2 {mu}m and the length of the pores reached to 400 {mu}m. Because of stability the photonic structures were superimposed on silicon substrate. The experimental set-up used for the THG experiments generates tuneable picosecond IR pulses (tuning range 1500-4000 cm{sup -1}). The IR-pulse hit the sample either perpendicular to the sample surface or under an angle {theta}. The sample can be rotated (f) around the surface normal. The generated third harmonic is analysed by a polarizer, spectrally filtered by a polychromator and registered by a CCD camera. The setup can be used either in transmission or in reflection mode. Optical transmission and reflection spectra of the Si bulk correspond well with the theoretical description, a 4-fold and a 8-fold dependencies of the azimuth angle resulting in the structure of the x{sup (3)}-tensor of (100)-Si. The situation changes dramatically if the PC with hexagonal structure is investigated

226Ra and 228Ra in scale and sludge samples and their correlation with the chemical composition.

Science.gov (United States)

Godoy, José Marcus; da Cruz, Rosana Petinatti

2003-01-01

In order to contribute to a future waste management policy related to the presence of technologically enhanced natural occurring radioactive material (TENORM) in the Brazilian petroleum industry, the present work presents the chemical composition and the (226)Ra and (228)Ra content of sludge and scales generated during the offshore E and P petroleum activities in the Campos Basin, the primary offshore oil production region in Brazil. The (226)Ra and (228)Ra content on 36 sludge and scales samples were determined by gamma-spectrometry. Based on X-ray diffractometry results, a chemical analysis schema for these samples was developed. The results have shown that scales are 75% barium and strontium sulfates, with a mean (226)Ra and (228)Ra content of 106 kBq kg(-1) and 78 kBq kg(-1), respectively. On the other hand, sludge samples have a much more complex chemical composition than the scales. The (226)Ra and (228)Ra content in sludge also varies much more than the content observed in the scales samples and ranged from 0.36 to 367 kBq kg(-1) and 0.25 to 343 kBq kg(-1), respectively.

LCA versus RA - an introduction

DEFF Research Database (Denmark)

Olsen, Stig Irving

2000-01-01

Risk Assessment (RA) of chemicals is an environmental management tool used to assess the risk of specific chemicals, which are harmful to man or the environment under certain circumstances of use or in certain environmental recipients. Life Cycle Assessment (LCA) or environmental assessment...... of Industrial Products) developed in Denmark (Wenzel et al., 1997), respectively. The interactions between the two tools can be viewed from two different angles: 1. As a general reflection of how the tools supplement each other in the total environmental effort. 2. As an assessment of coincidences...... on Principles and Methods for Hazard and Risk Assessment)focuses on an assessment of the toxicological and ecotoxicological risks, the focus of this article's comparison of assessment principles, data requirements etc. will be on the assessment of toxicity and ecotoxicity in EDIP's impact assessment methodology...

Far-UV, visible, and near-IR reflectance spectra of frosts of H2O, CO2, NH3 and SO2

Science.gov (United States)

Hapke, B.; Wells, E.; Wagner, J.; Partlow, W.

1981-01-01

Measurements in the 0.1-2.5 micron range are presented for the reflectance spectra of the frosts of several volatiles pertinent to the study of comet nuclei. The frost spectra have distinctive features permitting their identification by spectroscopic reflectance remote sensing, notably in the far UV. It is found that: (1) H2O has a minimum at 0.16 microns and a maximum at 0.13 microns; (2) CO2 has minima near 0.21, 0.18 and 0.125 microns, with maxima at 0.19, 0.135 and 0.120 microns; (3) NH3 is bright at wavelengths longer than 0.21 microns, where reflectance drops to a value of only a few per cent at shorter wavelengths; (4) SO2 has a sharp drop at 0.32 microns, with a minimum at 0.18 microns and a maximum at 0.13 microns. The features in the frost spectra largely correspond to absorption line bands in the gas phase.

Investigation of pollutant gases with molecular absorption spectroscopy

International Nuclear Information System (INIS)

Izairi, N; Ajredini, F.; Shehabi, M.

2011-01-01

This paper contains the molecular absorption spectroscopic investigation on environmental pollution by many pollutants. For this purpose a laser absorption spectroscopy at 630 nm wavelength has been applied to excite the molecular spectra in order to identify the presence of main gas pollutants. The following was the experimental procedure. Preliminary the presence of pollutants was identified. The gas champions were taken in live environment, in Tetovo streets where cars moved, and in some points in Tetovo suburbia, during different periods of the day. A special civet, part of the apparatus, has been filled by environmental air, and latter, put into the apparatus. A laser beam pulse passes throughout absorbing gas medium in the civet to excite the gas, and the absorbing spectra were automatically registered. The molecular band spectra registration has been performed by an FT-IR Spectrometer (Spectrum BX FT-IR Perkin Elmer). For this purpose the measurements were focused in spectral region of 2075 cm -1 to 2384 cm -1 for CO 2 and CO bands investigation. The importance of such measurements is to investigate the spectral properties of absorption spectra and molecular structure, and for monitoring the environmental pollution. (Author)

FDTD modeling of solar energy absorption in silicon branched nanowires.

Science.gov (United States)

Lundgren, Christin; Lopez, Rene; Redwing, Joan; Melde, Kathleen

2013-05-06

Thin film nanostructured photovoltaic cells are increasing in efficiency and decreasing the cost of solar energy. FDTD modeling of branched nanowire 'forests' are shown to have improved optical absorption in the visible and near-IR spectra over nanowire arrays alone, with a factor of 5 enhancement available at 1000 nm. Alternate BNW tree configurations are presented, achieving a maximum absorption of over 95% at 500 nm.

Living Matter Observations with a Novel Hyperspectral Supercontinuum Confocal Microscope for VIS to Near-IR Reflectance Spectroscopy

Directory of Open Access Journals (Sweden)

Francesca R. Bertani

2013-10-01

Full Text Available A broad range hyper-spectroscopic microscope fed by a supercontinuum laser source and equipped with an almost achromatic optical layout is illustrated with detailed explanations of the design, implementation and data. The real novelty of this instrument, a confocal spectroscopic microscope capable of recording high resolution reflectance data in the VIS-IR spectral range from about 500 nm to 2.5 μm wavelengths, is the possibility of acquiring spectral data at every physical point as defined by lateral coordinates, X and Y, as well as at a depth coordinate, Z, as obtained by the confocal optical sectioning advantage. With this apparatus we collect each single scanning point as a whole spectrum by combining two linear spectral detector arrays, one CCD for the visible range, and one InGaAs infrared array, simultaneously available at the sensor output channel of the home made instrument. This microscope has been developed for biomedical analysis of human skin and other similar applications. Results are shown illustrating the technical performances of the instrument and the capability in extracting information about the composition and the structure of different parts or compartments in biological samples as well as in solid statematter. A complete spectroscopic fingerprinting of samples at microscopic level is shown possible by using statistical analysis on raw data or analytical reflectance models based on Abelés matrix transfer methods.

Structure and linear spectroscopic properties of near IR polymethine dyes

International Nuclear Information System (INIS)

Webster, Scott; Padilha, Lazaro A.; Hu Honghua; Przhonska, Olga V.; Hagan, David J.; Van Stryland, Eric W.; Bondar, Mikhail V.; Davydenko, Iryna G.; Slominsky, Yuriy L.; Kachkovski, Alexei D.

2008-01-01

We performed a detailed experimental investigation and quantum-chemical analysis of a new series of near IR polymethine dyes with 5-butyl-7,8-dihydrobenzo[cd]furo[2,3-f]indolium terminal groups. We also synthesized and studied two neutral dyes, squaraine and tetraone, with the same terminal groups and performed a comparison of the spectroscopic properties of this set of 'near IR' dyes (polymethine, squaraine, and tetraone) with an analogous set of 'visible' dyes with simpler benzo[e]indolium terminal groups. From these measurements, we find that the dyes with dihydrobenzo[cd]furo[2,3-f]indolium terminal groups are characterized by a remarkably large shift ∼300 nm (∼200 nm for tetraone) of their absorption bands towards the red region. We discuss the difference in electronic structure for these molecules and show that the 'near IR' dyes are characterized by an additional weak fluorescence band from the higher lying excited states connected with the terminal groups. Absorption spectra for the longest polymethines are solvent-dependent and are characterized by a broadening of the main band in polar solvents, which is explained by ground state symmetry breaking and reduced charge delocalization within the polymethine chromophore. The results of these experiments combined with the agreement of quantum chemical calculations moves us closer to a predictive capability for structure-property relations in cyanine-like molecules

Tīmekļa lietojumprogrammatūra elektroniskai tirdzniecībai tiešsaistē

OpenAIRE

Folkmanis, Kristaps

2014-01-01

“Tīmekļa lietojumprogrammatūra elektroniskai tirdzniecībai tiešsaistē” ir uz tīmekļa tehnoloģijām balstīta sistēma, kas realizēta kā interneta vietne. Sistēmas lietotājiem ir iespēja apskatīt un iegādāties preces, kas sadalītas pa dažādām kategorijām. Lietotāji var veikt arī citas papildus darbības, piemēram, reģistrēties sistēmā, pievienot precēm komentārus un pārvaldīt savu iepirkumu grozu. Sistēmas administrators var pārvaldīt visu preču klāstu un citus sistēmā esošos datus, izmantojot šim...

A mathematical procedure to estimate solar absorptance of shallow water ponds

International Nuclear Information System (INIS)

Wu Hongbo; Tang Runsheng; Li Zhimin; Zhong Hao

2009-01-01

In this article, a mathematical procedure is developed for estimating solar absorption of shallow water ponds with different pond floor based on the fact that the solar radiation trapped inside the water layer undergoes multiplicative reflection and absorption and on that the solar absorption of water is selective. Theoretical model indicates that the solar absorption of a water pond is related to the reflectivity of the pond floor, the solar spectrum and the water depth. To validate the mathematical model, a concrete water pond measuring 3 x 3 x 0.24 m was constructed. Experimental results indicate that solar reflectivity calculated based on the mathematical model proposed in this work were in good agreement with those measured. For water ponds with a water-permeable floor, such as concrete floor, theoretical calculations of the solar absorptance of a water pond should be done based on the reflectivity of full wet floor, whereas for water ponds with a non-water-permeable floor, theoretical calculations should be done based on the fact that solar reflection on the floor is neither perfect specular reflection nor prefect isotropic diffuse reflection. Results of numerical calculation show that theoretical calculations of solar absorption of a water pond by dividing solar spectrum into six bands were pretty agreement with those by dividing solar spectrum into 20 bands.

Neariminio žemės dirbimo ir augalinių liekanų poveikis žieminių kviečių agroekosistemos komponentams

OpenAIRE

Leimonaitė, Laura

2012-01-01

Žemės dirbimas yra vienas iš daugiausia darbo, energetinių bei laiko sąnaudų reikalaujančių technologinių darbų auginant augalus. Todėl įvairaus intensyvumo žemės dirbimo sistemų nustatymas, kurios nemažindamos žemės ūkio augalų derliaus neblogintų dirvožemio agrocheminių savybių, yra svarbus ir ekonomine, ir aplinkosaugine prasme. Pasikliaujama ribotu paviršiaus purenimu, ražienine sėja. Taip sutaupomos lėšos, mažiau gaištama laiko dirvai ruošti. Dėl gilaus ir pastovaus žemės dirbimo gali ma...

Effect of iron status on iron absorption in different habitual meals in young south Indian women

Directory of Open Access Journals (Sweden)

Suneeta Kalasuramath

2013-01-01

Full Text Available Background & objectives: Iron deficiency (ID affects a large number of women in India. An inverse relationship exists between iron (Fe status and Fe absorption. Dietary inhibitory and enhancing factors exert a profound influence on bioavailability of Fe. Although the current recommended dietary allowance (RDA for Fe is based on 8 per cent bioavailability, it is not clear if this holds good for the usual highly inhibitory Indian diet matrix. This study was aimed to determine Fe absorption from several habitually consumed south Indian food and to evaluate the interaction of Fe status with absorption. Methods: Four Fe absorption studies were performed on 60 apparently healthy young women, aged 18-35 years. Based on blood biochemistry, 45 of them were ID and 15 were iron replete (IR. The habitual meals assessed were rice, millet and wheat based meals in the ID subjects and rice based meal alone in the IR subjects. Each subject received the test meal labelled with 3 mg of [57] Fe and Fe absorption was measured based on erythrocyte incorporation of isotope label 14 days following administration. Results: Mean fractional Fe absorption from the rice, wheat and millet based meals in the ID subjects were 8.3, 11.2 and 4.6 per cent, respectively. Fe absorption from the rice-based meals was 2.5 per cent in IR subjects. Interpretation & conclusions: Fe absorption is dictated by Fe status from low bioavailability meals. Millet based meals have the lowest bioavailability, while the rice and wheat based meals had moderate to good bioavailability. In millet based meals, it is prudent to consider ways to improve Fe absorption.

Improving the performance of infrared reflective night curtains for warming field plots

DEFF Research Database (Denmark)

Bruhn, Dan; Larsen, Klaus S.; de Dato, Giovanbattista D.

2013-01-01

Infrared reflective (IR) curtains have been widely used to obtain passive nighttime warming in field ecosystem experiments in order to simulate and study climate warming effects on ecosystems. For any field installation with IR-reflective curtains in an ecosystem the achieved heating effect depen...

Analysis of gaseous ammonia (NH3) absorption in the visible spectrum of Jupiter

Science.gov (United States)

Irwin, Patrick G. J.; Bowles, Neil; Braude, Ashwin S.; Garland, Ryan; Calcutt, Simon

2018-03-01

Observations of the visible/near-infrared reflectance spectrum of Jupiter have been made with the Very Large Telescope (VLT) Multi Unit Spectroscopic Explorer (MUSE) instrument in the spectral range 0.48-0.93 μm in support of the NASA/Juno mission. These spectra contain spectral signatures of gaseous ammonia (NH3), whose abundance above the cloud tops can be determined if we have reliable information on its absorption spectrum. While there are a number of sources of NH3 absorption data in this spectral range, they cover small sub-ranges, which do not necessarily overlap and have been determined from a variety of sources. There is thus considerable uncertainty regarding the consistency of these different sources when modelling the reflectance of the entire visible/near-IR range. In this paper we analyse the VLT/MUSE observations of Jupiter to determine which sources of ammonia absorption data are most reliable. We find that the band model coefficients of Bowles et al. (2008) provide, in general, the best combination of reliability and wavelength coverage over the MUSE range. These band data appear consistent with ExoMOL ammonia line data of Yurchenko et al. (2011), at wavelengths where they overlap, but these latter data do not cover the ammonia absorption bands at 0.79 and 0.765 μm, which are prominent in our MUSE observations. However, we find the band data of Bowles et al. (2008) are not reliable at wavelengths less than 0.758 μm. At shorter wavelengths we find the laboratory observations of Lutz and Owen (1980) provide a good indication of the position and shape of the ammonia absorptions near 0.552 μm and 0.648 μm, but their absorption strengths appear inconsistent with the band data of Bowles et al. (2008) at longer wavelengths. Finally, we find that the line data of the 0.648 μm absorption band of Giver et al. (1975) are not suitable for modelling these data as they account for only 17% of the band absorption and cannot be extended reliably to the cold

Interference scattering effects on intermediate resonance absorption at operating temperatures

International Nuclear Information System (INIS)

Goldstein, R.

1975-01-01

Resonance integrals may be accurately calculated using the intermediate resonance (IR) approximation. Results are summarized for the case of an absorber with given potential scattering cross sections and interference scattering parameter admixed with a non absorbing moderator of given cross section and located in a narrow resonance moderating medium. From the form of the IR solutions, it is possible to make some general observations about effects of interference scattering on resonance absorption. 2 figures

Multifunctional hybrids for electromagnetic absorption

International Nuclear Information System (INIS)

Huynen, I.; Quievy, N.; Bailly, C.; Bollen, P.; Detrembleur, C.; Eggermont, S.; Molenberg, I.; Thomassin, J.M.; Urbanczyk, L.

2011-01-01

Highlights: → EM absorption requires low dielectric constant and ∼1 S/m electrical conductivity. → New hybrids were processed with CNT-filled polymer foam inserted in Al honeycomb. → The EM absorption in the GHz range is superior to any known material. → A closed form model is used to guide the design of the hybrid. → The architectured material is light with potential for thermal management. - Abstract: Electromagnetic (EM) interferences are ubiquitous in modern technologies and impact on the reliability of electronic devices and on living cells. Shielding by EM absorption, which is preferable over reflection in certain instances, requires combining a low dielectric constant with high electrical conductivity, which are antagonist properties in the world of materials. A novel class of hybrid materials for EM absorption in the gigahertz range has been developed based on a hierarchical architecture involving a metallic honeycomb filled with a carbon nanotube-reinforced polymer foam. The waveguide characteristics of the honeycomb combined with the performance of the foam lead to unexpectedly large EM power absorption over a wide frequency range, superior to any known material. The peak absorption frequency can be tuned by varying the shape of the honeycomb unit cell. A closed form model of the EM reflection and absorption provides a tool for the optimization of the hybrid. This designed material sets the stage for a new class of sandwich panels combining high EM absorption with mass efficiency, stiffness and thermal management.

RA Research nuclear reactor Part 1, RA Reactor operation and maintenance in 1987

International Nuclear Information System (INIS)

Sotic, O.; Martinc, R.; Cupac, S.; Sulem, B.; Badrljica, R.; Majstorovic, D.; Sanovic, V.

1987-01-01

RA research reacto was not operated due to the prohibition issued in 1984 by the Government of Serbia. Three major tasks were finished in order to fulfill the licensing regulations about safety of nuclear facilities which is the condition for obtaining permanent operation licence. These projects involved construction of the emergency cooling system, reconstruction of the existing special ventilation system, and renewal of the system for electric power supply of the reactor systems. Renewal of the RA reactor instrumentation system was initiated. Design project was done by the Russian Atomenergoeksport, and is foreseen to be completed by the end of 1988. The RA reactor safety report was finished in 1987. This annual report includes 8 annexes concerning reactor operation, activities of services and financial issues, and three special annexes: report on testing the emergency cooling system, report on renewal of the RA reactor and design specifications for reactor renewal and reconstruction [sr

The Importance of Surface IrO_x in Stabilizing RuO₂ for Oxygen Evolution

DEFF Research Database (Denmark)

Escribano, Maria Escudero; Pedersen, Anders Filsøe; Paoli, Elisa Antares

2018-01-01

consisting of RuO2 thin films with sub-monolayer (1, 2 and 4 Å) amounts of IrOx deposited on top. Operando extended X-ray absorption fine structure (EXAFS) on the Ir L-3 edge revealed a rutile type IrO2 structure with some Ir sites occupied by Ru, IrOx being at the surface of the RuO2 thin film. We monitor...... corrosion on IrOx/RuO2 thin films by combining electrochemical quartz crystal microbalance (EQCM) with inductively coupled mass spectrometry (ICP-MS). We elucidate the importance of sub-monolayer surface IrOx in minimizing Ru dissolution. Our work shows that we can tune the surface properties of active OER...

Neutron reflection effect on total absorption detector method used in SWINPC neutron multiplication experiment for beryllium

International Nuclear Information System (INIS)

Tian Dongfeng; Ho Yukun; Yang Fujia

2001-01-01

The SWINPC integral experiment on neutron multiplication in bulk beryllium showed that there were marked discrepancies between experimental data and calculated values with the ENDF/B-VI data. The calculated values become higher than experimental ones as the sample thickness increases. Several works had been devoted to find problems existing in the experiment. This paper discusses the neutron reflection effect on the total absorption detector method which was used in the experiment to measure the neutron leakage from samples. One systematic correction is suggested to make the experimental values agree with the calculated ones with the ENDF/B-VI data within experimental errors. (author)

Design of mini-multi-gas monitoring system based on IR absorption

Energy Technology Data Exchange (ETDEWEB)

Tan, Q.L.; Zhang, W.D.; Xue, C.Y.; Xiong, J.J.; Ma, Y.C.; Wen, F. [Northern University of China, Taiyuan (China)

2008-07-15

In this paper, a novel non-dispersive infrared ray (IR) gas detection system is described. Conventional devices typically include several primary components: a broadband source (usually all incandescent filament), a rotating chopper shutter, a narrow-band filter, a sample tube and a detector. But we mainly use file mini-multi-channel detector, electrical modulation means and mini-gas-cell structure. To solve the problems of gas accidents in coal mines, and for family safety that results from using gas, this new IR detection system with integration, miniaturization and non-moving parts has been developed. It is based on the principle that certain gases absorb infrared radiation at specific (and often unique) wavelengths. The infrared detection optics principle used in developing this system is mainly analyzed. The idea of multi-gas detection is introduced and guided through the analysis of the single-gas detection. Through researching the design of cell structure, a cell with integration and miniaturization has been devised. By taking a single-chip microcomputer (SCM) as intelligence handling, the functional block diagram of a gas detection system is designed with the analyzing and devising of its hardware and software system. The way of data transmission on a controller area network (CAN) bus and wireless data transmission mode is explained. This system has reached the technology requirement of lower power consumption, mini-volume, wide measure range, and is able to realize multi-gas detection.

Rapid, nondestructive estimation of surface polymer layer thickness using attenuated total reflection fourier transform infrared (ATR FT-IR) spectroscopy and synthetic spectra derived from optical principles.

Science.gov (United States)

Weinstock, B André; Guiney, Linda M; Loose, Christopher

2012-11-01

We have developed a rapid, nondestructive analytical method that estimates the thickness of a surface polymer layer with high precision but unknown accuracy using a single attenuated total reflection Fourier transform infrared (ATR FT-IR) measurement. Because the method is rapid, nondestructive, and requires no sample preparation, it is ideal as a process analytical technique. Prior to implementation, the ATR FT-IR spectrum of the substrate layer pure component and the ATR FT-IR and real refractive index spectra of the surface layer pure component must be known. From these three input spectra a synthetic mid-infrared spectral matrix of surface layers 0 nm to 10,000 nm thick on substrate is created de novo. A minimum statistical distance match between a process sample's ATR FT-IR spectrum and the synthetic spectral matrix provides the thickness of that sample. We show that this method can be used to successfully estimate the thickness of polysulfobetaine surface modification, a hydrated polymeric surface layer covalently bonded onto a polyetherurethane substrate. A database of 1850 sample spectra was examined. Spectrochemical matrix-effect unknowns, such as the nonuniform and molecularly novel polysulfobetaine-polyetherurethane interface, were found to be minimal. A partial least squares regression analysis of the database spectra versus their thicknesses as calculated by the method described yielded an estimate of precision of ±52 nm.

Migration of 226 Ra, 228 Ra, 210 Pb, U and Th from phosphogypsum

International Nuclear Information System (INIS)

Silva, Nivaldo Carlos da; Cipriani, Moacir; Taddei, Maria Helena T.

2002-01-01

The physico-chemical availability of radioactive elements ( 210 Pb, 226 Ra, 228 Ra, Th and U) in Brazilian phosphogypsum was investigated in a large scale leaching experiment carried out in lysimeters, using phosphogypsum samples (approximately 1.2 tons) from two phosphoric acid industries. Lysimeters were built using cylindrical concrete containers with 0.9 m inner diameter and 2 m depth. The bottom of the lysimeter was filled with a 10 cm layer of gravel covered with geomembrane sheet. Under this layer a pipe was designed to drain the percolated water. Three lysimeters were filled with phosphogypsum from each industry and a mixture of both. As percolated water comes exclusively from the rain, sample was collected daily when available. Samples were then pooled weekly, carefully prepared and submitted to radiochemical analysis. Radiochemical characterization of phosphogypsum and percolated water was performed by radiochemical separation followed by gross alpha and beta counting ( 226 Ra, 228 Ra and 210 Pb) and UV-Vis spectrophotometry with Arsenazo III (U and Th). This experiment was carried out from 12/01/1999 to 01/22/2001, with a precipitation of 2,732 mm. It was observed that approximately 40% (534 L) of the rain fall percolated through the lysimeter 1. The analysis of 22 samples of percolated water from lysimeter 1 showed mean radionuclides activities of 70±30 mBqL -1 , 70±50 mBqL -1 , 100±60 mBqL -1 and 110±55 mBqL -1 for U, 226 Ra, 228 Ra and 210 Pb, respectively. Thorium activities were below detection limit. (author)

Impaired Insulin Signaling is Associated with Hepatic Mitochondrial Dysfunction in IR+/−-IRS-1+/− Double Heterozygous (IR-IRS1dh Mice

Directory of Open Access Journals (Sweden)

Andras Franko

2017-05-01

Full Text Available Mitochondria play a pivotal role in energy metabolism, but whether insulin signaling per se could regulate mitochondrial function has not been identified yet. To investigate whether mitochondrial function is regulated by insulin signaling, we analyzed muscle and liver of insulin receptor (IR+/−-insulin receptor substrate-1 (IRS-1+/− double heterozygous (IR-IRS1dh mice, a well described model for insulin resistance. IR-IRS1dh mice were studied at the age of 6 and 12 months and glucose metabolism was determined by glucose and insulin tolerance tests. Mitochondrial enzyme activities, oxygen consumption, and membrane potential were assessed using spectrophotometric, respirometric, and proton motive force analysis, respectively. IR-IRS1dh mice showed elevated serum insulin levels. Hepatic mitochondrial oxygen consumption was reduced in IR-IRS1dh animals at 12 months of age. Furthermore, 6-month-old IR-IRS1dh mice demonstrated enhanced mitochondrial respiration in skeletal muscle, but a tendency of impaired glucose tolerance. On the other hand, 12-month-old IR-IRS1dh mice showed improved glucose tolerance, but normal muscle mitochondrial function. Our data revealed that deficiency in IR/IRS-1 resulted in normal or even elevated skeletal muscle, but impaired hepatic mitochondrial function, suggesting a direct cross-talk between insulin signaling and mitochondria in the liver.

Measurements at the RA Reactor related to the VISA-2 project - Part 1, Start-up of the RA reactor and measurement of new RA reactor core parameters; Fizicka merenja na reaktoru RA u vezi projekta VISA-2 - I deo, Pustanje u rad reaktora RA i merenje fizickih parametara novog jezgra reaktora RA

Energy Technology Data Exchange (ETDEWEB)

Markovic, H [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1962-07-15

The objective of the measurements was determining the neutron flux in the RA reactor core. Since the number of fuel channels is increased from 56 to 68 within the VISA-2 project, it was necessary to attain criticality of the RA reactor and measure the neutron flux properties. The 'program of RA reactor start-up' has been prepared separately and it is included in this report. Measurements were divided in two phases. First phase was measuring of the neutron flux after the criticality was achieved but at zero power. During phase two measurements were repeated at several power levels, at equilibrium xenon poisoning. This report includes experimental data of flux distributions and absolute values of the thermal and fast neutron flux in the RA reactor experimental channels and values of cadmium ratio for determining the neutron epithermal flux. Data related to calibration of regulatory rods for cold un poisoned core are included. [Serbo-Croat] Svrha merenja je odredjivanje neutronskog fluksa u reaktoru RA. S obzirom na uvecani broj tehnoloskih kanala of 56 na 68 u vezi projekta VISA-2, bilo je potrebno ponovo dovesti reaktora RA do kriticnosti i izvrsiti merenja karakteristika fluksa neutrona. Posebno je pripremljen 'program pustanja u pogon reaktora RA', koji je sadrzan u ovom dokumentu. Program merenja bio je podeljen na dve faze. Prva faza je merenje fluksa pre podizanju reaktora na nominalnu snagu. Slicna merenja vrsena su i na vecim snagama u drugoj fazi, pod uslovima ravnoteznog zatrovanja reaktora ksenonom, jer se tada pokazuju izvesne promene u odgovarajucim karakteristikama fluksa neutrona. Ovaj izvestaj sadrzi merene vrednosti raspodele fluksa i apsolutne vrednosti termalnih i brzih neutrona kao i kadmijumskih odnosa koji su korisceni za odredjivanje fluksa epitermalnih neutrona. Opisana je kalibracija regulacionih sipki za hladan nezatrovan reaktor.

Experimental test of resonant absorption theory. Final report, January 1, 1978-December 31, 1979

International Nuclear Information System (INIS)

Yablonovitch, E.

1979-05-01

This experimental research has probed the nature of resonant absorption (RA) of laser light by laser-produced plasmas. The plasmas were created by optical breakdown of a shockfront produced in an electrothermal shock tube. This procedure allows the density structure of the plasma, and in particular, the orientation of the plasma critical-density surface, to be reproducibly formed from one shot to the next. Thus, for the first time, RA has been controllably and reproducibly studied in isolation from other plasma physics. The angular distribution of fast electrons emitted by RA and wavebreaking has been studied, and it is observed that the emission is directed in a narrow cone centered on the shockfront density-gradient vector, in agreement with the theory of wavebreaking

Research nuclear reactor RA - Annual Report 1997; Istrazivacki nuklearni reaktor RA - Izvestaj za 1997. godinu

Energy Technology Data Exchange (ETDEWEB)

Sotic, O [Vinca Institute of Nuclear Sciences, Beograd (Serbia and Montenegro)

1997-12-01

RA reactor is not in operation since 1984, activities related to revitalisation of the RA reactor started in 1986. The planned actions related to renewal of the reactor components were finished except for the most important action, related to exchange of complete reactor instrumentation which was delayed. Only 80% of the instrumentation was delivered until September 1991. Since then any delivery of components to Yugoslavia was stopped because of the sanctions imposed to our country. The existing RA reactor instrumentation was dismantled. Control and maintenance of the reactor components was done regularly and efficiently. Fuel inspection by the IAEA safeguards inspectors was done on a monthly basis. There have been on the average 42 employees at the RA reactor which is considered sufficient for maintenance and repair conditions. The problem of financing the reactor activities and maintenance remains unsolved. Research reactor RA Annual report for year 1997 is divided into two main parts to cover: (1) operation and maintenance and (2) activities related to radiation protection. [Serbo-Croat] Reaktor RA nije u pogonu od 1984, aktivnosti na revitalizaciji, rekostrukciji i modernizaciji reaktorski sistema zapocete su 1986. godine. Okoncan je niz zahvata na opremi postrojenja kojima ce se u narednom periodu omoguciti kontinualan i pouzdan rad ovog reaktora. Poslednji, i ujedno najveci zahvat, koji se odnosi na zamenu celokupne instrumentacije kasni zbog zastoja u isporuci opreme koja se izradjuje u Sovjetskom savezu. Do septembra 1991. godine isporuceno svega 80% od predvidjene kolicine. Od tada je svaka isporuka obustavljena, a razlog je privremena zabrana na sve isporuke opreme za Jugoslaviju usled sankcija uvedenih od strane organizacije Ujedinjenih nacija. Demontirana je postojeca instrumentacija. Kontrola i odrzavanje celopkupne opreme postrojenja, kao i remontni radovi izvrsavani su redovno i efikasno. Kontrola goriva od strane safeguard inspektora MAAE obavljana

Photodissociation Spectroscopy of Cold Protonated Synephrine: Surprising Differences between IR-UV Hole-Burning and IR Photodissociation Spectroscopy of the O-H and N-H Modes.

Science.gov (United States)

Nieuwjaer, N; Desfrançois, C; Lecomte, F; Manil, B; Soorkia, S; Broquier, M; Grégoire, G

2018-04-19

We report the UV and IR photofragmentation spectroscopies of protonated synephrine in a cryogenically cooled Paul trap. Single (UV or IR) and double (UV-UV and IR-UV) resonance spectroscopies have been performed and compared to quantum chemistry calculations, allowing the assignment of the lowest-energy conformer with two rotamers depending on the orientation of the phenol hydroxyl (OH) group. The IR-UV hole burning spectrum exhibits the four expected vibrational modes in the 3 μm region, i.e., the phenol OH, C β -OH, and two NH 2 + stretches. The striking difference is that, among these modes, only the free phenol OH mode is active through IRPD. The protonated amino group acts as a proton donor in the internal hydrogen bond and displays large frequency shifts upon isomerization expected during the multiphoton absorption process, leading to the so-called IRMPD transparency. More interestingly, while the C β -OH is a proton acceptor group with moderate frequency shift for the different conformations, this mode is still inactive through IRPD.

Terahertz gas sensor based on absorption-induced transparency

Directory of Open Access Journals (Sweden)

Rodrigo Sergio G.

2016-01-01

Full Text Available A system for the detection of spectral signatures of gases at the Terahertz regime is presented. The system consists in an initially opaque holey metal film whereby the introduction of a gas provokes the appearance of spectral features in transmission and reflection, due to the phenomenom of absorption-induced transparency (AIT. The peaks in transmission and dips in reflection observed in AIT occur close to the absorption energies of the molecules, hence its name. The presence of the gas would be thus revealed as a strong drop in reflectivity measurements at one (or several of the gas absorption resonances. As a proof of principle, we theoretically demonstrate how the AIT-based sensor would serve to detect tiny amounts of hydrocyanic acid.

Detection of cancerous biological tissue areas by means of infrared absorption and SERS spectroscopy of intercellular fluid

Science.gov (United States)

Velicka, M.; Urboniene, V.; Ceponkus, J.; Pucetaite, M.; Jankevicius, F.; Sablinskas, V.

2015-08-01

We present a novel approach to the detection of cancerous kidney tissue areas by measuring vibrational spectra (IR absorption or SERS) of intercellular fluid taken from the tissue. The method is based on spectral analysis of cancerous and normal tissue areas in order to find specific spectral markers. The samples were prepared by sliding the kidney tissue over a substrate - surface of diamond ATR crystal in case of IR absorption or calcium fluoride optical window in case of SERS. For producing the SERS signal the dried fluid film was covered by silver nanoparticle colloidal solution. In order to suppress fluorescence background the measurements were performed in the NIR spectral region with the excitation wavelength of 1064 nm. The most significant spectral differences - spectral markers - were found in the region between 400 and 1800 cm-1, where spectral bands related to various vibrations of fatty acids, glycolipids and carbohydrates are located. Spectral markers in the IR and SERS spectra are different and the methods can complement each other. Both of them have potential to be used directly during surgery. Additionally, IR absorption spectroscopy in ATR mode can be combined with waveguide probe what makes this method usable in vivo.

Enface Thickness Mapping and Reflectance Imaging of Retinal Layers in Diabetic Retinopathy.

Science.gov (United States)

Francis, Andrew W; Wanek, Justin; Lim, Jennifer I; Shahidi, Mahnaz

2015-01-01

To present a method for image segmentation and generation of enface thickness maps and reflectance images of retinal layers in healthy and diabetic retinopathy (DR) subjects. High density spectral domain optical coherence tomography (SDOCT) images were acquired in 10 healthy and 4 DR subjects. Customized image analysis software identified 5 retinal cell layer interfaces and generated thickness maps and reflectance images of the total retina (TR), inner retina (IR), outer retina (OR), and the inner segment ellipsoid (ISe) band. Thickness maps in DR subjects were compared to those of healthy subjects by generating deviation maps which displayed retinal locations with thickness below, within, and above the normal 95% confidence interval. In healthy subjects, TR and IR thickness maps displayed the foveal depression and increased thickness in the parafoveal region. OR and ISe thickness maps showed increased thickness at the fovea, consistent with normal retinal anatomy. In DR subjects, thickening and thinning in localized regions were demonstrated on TR, IR, OR, and ISe thickness maps, corresponding to retinal edema and atrophy, respectively. TR and OR reflectance images showed reduced reflectivity in regions of increased thickness. Hard exudates appeared as hyper-reflective spots in IR reflectance images and casted shadows on the deeper OR and ISe reflectance images. The ISe reflectance image clearly showed the presence of focal laser scars. Enface thickness mapping and reflectance imaging of retinal layers is a potentially useful method for quantifying the spatial and axial extent of pathologies due to DR.

Contribution of chlorophyll fluorescence to the apparent vegetation reflectance

International Nuclear Information System (INIS)

Campbell, P.K. Entcheva; Middleton, E.M.; Corp, L.A.; Kim, M.S.

2008-01-01

Current strategies for monitoring the physiologic status of terrestrial vegetation rely on remote sensing reflectance data, which provide estimates of vigor based primarily on chlorophyll content. Chlorophyll fluorescence (ChlF) measurements offer a non-destructive alternative and a more direct approach for diagnosis of vegetation stress before a significant reduction in chlorophyll content has occurred. Thus, technology based on ChlF may allow more accurate carbon sequestration estimates and earlier stress detection than is possible when using reflectance data alone. However, the observed apparent vegetation reflectance (Ra) in reality includes contributions from both the reflected and fluoresced radiation. The aim of this study is to determine the relative contributions of reflectance and ChlF fractions to Ra in the red to near-infrared region (650-800 nm) of the spectrum. The practical objectives of the study are to: 1) evaluate the relationship between ChlF and reflectance at the foliar level for corn, soybean and maple; and 2) for corn, determine if the relationship established for healthy vegetation changes under nitrogen (N) deficiency. To obtain generally applicable results, experimental measurements were conducted on unrelated crop and tree species (corn, soybean and maple) under controlled conditions and a gradient of inorganic N fertilization levels. Optical reflectance spectra and actively induced ChlF emissions were collected on the same foliar samples, in conjunction with measurements of photosynthetic function, pigment levels, and carbon (C) and N content. The spectral trends were examined for similarities. On average, 10-20% of Ra at 685 nm was actually due to ChlF. The spectral trends in steady state and maximum fluorescence varied significantly, with steady state fluorescence (especially red, 685 nm) showing higher ability for species and treatment separation. The relative contribution of ChlF to Ra varied significantly among species, with maple

226Ra-230Th Disequilibria in Magmas from Llaima and Lonquimay Volcanoes, Chile: On the Roles and Rates of Subvolcanic Magmatic Processes.

Science.gov (United States)

Reubi, O.; Cooper, L. B.; Dungan, M. A.; Bourdon, B.

2014-12-01

226Ra excesses in mafic arc magmas are generally attributed to recent (contamination had a secondary influence on 226Ra-230Th disequilibria. Magmas with the highest AFC contribution have 226Ra-230Th close to equilibrium, implying that (226Ra-230Th) are mostly affected by either differentiation on time scales of ~8 kyr, or more likely, mixing with mush bodies several kyr old. Lonquimay magmas (52 to 64 wt% SiO2) are almost aphyric. Their evolution was controlled by fractional crystallization with limited crustal contamination. (226Ra-230Th) range from moderate 226Ra excesses to small deficits, and are negatively correlated with Ba/Th and MgO. These observations are difficult to reconcile with only slab-fluid addition and mantle melting. We posit that this (226Ra-230Th) range results from diffusive Ra-exchange between young recharge melts and an old crystal mush. A similar process may also explain 226Ra deficits at some other SVZ volcanoes. Thus (226Ra-230Th) in erupted magmas reflect modification of mantle-derived signatures by open-system magmatic processes in the crust. 1Sigmarsson et al., 2002, Earth and Planet. Sc. Lett. 196, 189-196. 2 Reubi et al., 2011, Earth and Planet. Sc. Lett. 303, 37-47.

Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) for Rapid Determination of Microbial Cell Lipid Content: Correlation with Gas Chromatography-Mass Spectrometry (GC-MS).

Science.gov (United States)

Millan-Oropeza, Aaron; Rebois, Rolando; David, Michelle; Moussa, Fathi; Dazzi, Alexandre; Bleton, Jean; Virolle, Marie-Joelle; Deniset-Besseau, Ariane

2017-10-01

There is a growing interest worldwide for the production of renewable oil without mobilizing agriculture lands; fast and reliable methods are needed to identify highly oleaginous microorganisms of potential industrial interest. The aim of this study was to demonstrate the relevance of attenuated total reflection (ATR) spectroscopy to achieve this goal. To do so, the total lipid content of lyophilized samples of five Streptomyces strains with varying lipid content was assessed with two classical quantitative but time-consuming methods, gas chromatography-mass spectrometry (GC-MS) and ATR Fourier transform infrared (ATR FT-IR) spectroscopy in transmission mode with KBr pellets and the fast ATR method, often questioned for its lack of reliability. A linear correlation between these three methods was demonstrated allowing the establishment of equations to convert ATR values expressed as CO/amide I ratio, into micrograms of lipid per milligram of biomass. The ATR method proved to be as reliable and quantitative as the classical GC-MS and FT-IR in transmission mode methods but faster and more reproducible than the latter since it involves far less manipulation for sample preparation than the two others. Attenuated total reflection could be regarded as an efficient fast screening method to identify natural or genetically modified oleaginous microorganisms by the scientific community working in the field of bio-lipids.

Infrared reflection nebulae in Orion Molecular Cloud

International Nuclear Information System (INIS)

Pendleton, Y.; Werner, M.W.; Capps, R.; Lester, D.; Hawaii Univ., Honolulu; Texas Univ., Austin)

1986-01-01

New observations of Orion Molecular Cloud 2 have been made from 1 to 100 microns using the NASA Infrared Telescope Facility and the Kuiper Airborne Observatory. An extensive program of polarimetry, photometry, and spectrophotometry has shown that the extended emission regions associated with two of the previously known near-infrared sources, IRS 1 and IRS 4, are infrared reflection nebulae, and that the compact sources IRS 1 and IRS 4 are the main luminosity sources in the cloud. The constraints from the far-infrared observations and an analysis of the scattered light from the IRS 1 nebula show that OMC-2/IRS 1 can be characterized by L of 500 solar luminosities or less and T of roughly 1000 K. The near-infrared albedo of the grains in the IRS 1 nebula is greater than 0.08. 27 references

Combined IR-Raman vs vibrational sum-frequency heterospectral correlation spectroscopy

Science.gov (United States)

Roy, Sandra; Beutier, Clémentine; Hore, Dennis K.

2018-06-01

Vibrational sum-frequency generation spectroscopy is a valuable probe of surface structure, particularly when the same molecules are present in one of the adjacent bulk solid or solution phases. As a result of the non-centrosymmetric requirement of SFG, the signal generated is a marker of the extent to which the molecules are ordered in an arrangement that breaks the up-down symmetry at the surface. In cases where the accompanying changes in the bulk are of interest in understanding and interpreting the surface structure, simultaneous analysis of the bulk IR absorption or bulk Raman scattering is helpful, and may be used in heterospectral surface-bulk two-dimensional correlation. We demonstrate that, in such cases, generating a new type of bulk spectrum that combines the IR and Raman amplitudes is a better candidate than the individual IR and Raman spectra for the purpose of correlation with the SFG signal.

Ra-226 bioaccumulation and growth indices in fish.

Science.gov (United States)

Shi, Xiaopei; Smith, Richard; Seymour, Colin; Mothersill, Carmel

2017-06-01

To determine the accumulated activity of Ra-226 in fathead minnows fed with environmentally relevant levels of Ra-226 for 5 months in water at 20 °C, and to evaluate the influence of this level of Ra-226 on the growth of fathead minnows. Fathead minnows were fed with fish food containing 10-10,000 mBq/g Ra-226 for 5 months. At the end of the experiment, the fish were sacrificed, flash frozen in liquid nitrogen and kept at -20 °C. Longitudinal sections of 40 μm thickness were cut at the middle of the fish body using a cryostat. The activity of Ra-226 in each section was determined using autoradiography with a nuclear track detector CR-39. According to the weight and the width of the fish, the activity of Ra-226 in the whole fish body could be estimated. In addition, the length and the weight of the fish were measured and the condition factor was calculated to evaluate the growth and fitness of the fish. There is a positive but non-linear relationship between the accumulated activity of Ra-226 in fish body and the concentration of Ra-226 in fish food. The highest activity of Ra-226 accumulated in fish body was found from fish fed with 10,000 mBq/g Ra-226 food. This was calculated as 256.4 ± 49.1 mBq/g, p fish fed with food containing lower concentration of Ra-226 (up to 1000 mBq/g), the bioaccumulation of Ra-226 in the body saturated. The Ra-226 concentration factor (CF) for fish was inversely proportional to the Ra-226 activity in food, and the highest CF value was 2.489, obtained from the lowest dietary Ra-226 activity (10 mBq/g). In addition, condition factors (K) of fish in all Ra-226-treated groups were significantly lower than those of the controls. The results show that the bioaccumulation of Ra-226 in fish is not simply related to the dietary Ra-226 activity, and has a saturation value when the dietary activity is low. In addition, the environmental level of Ra-226 in the fish food has a small adverse effect on the growth and fitness of fathead

Broadband enhancement of infrared absorption in microbolometers using Ag nanocrystals

International Nuclear Information System (INIS)

Hyun, Jerome K.; Ahn, Chi Won; Kim, Woo Choong; Kim, Tae Hyun; Hyun, Moon Seop; Kim, Hee Yeoun; Park, Jae Hong; Lee, Won-Oh

2015-01-01

High performance microbolometers are widely sought for thermal imaging applications. In order to increase the performance limits of microbolometers, the responsivity of the device to broadband infrared (IR) radiation needs to be improved. In this work, we report a simple, quick, and cost-effective approach to modestly enhance the broadband IR response of the device by evaporating Ag nanocrystals onto the light entrance surface of the device. When irradiated with IR light, strong fields are built up within the gaps between adjacent Ag nanocrystals. These fields resistively generate heat in the nanocrystals and underlying substrate, which is transduced into an electrical signal via a resistive sensing element in the device. Through this method, we are able to enhance the IR absorption over a broadband spectrum and improve the responsivity of the device by ∼11%

Electromagnetic-wave absorption by inhomogeneous, collisional plasmas

International Nuclear Information System (INIS)

Gregoire, D.J.; Santoru, J.; Schumacher, R.W.

1990-01-01

Unmagnetized, collisional plasmas can be used as broadband EM-wave absorbers or refractors. In the absorption process, plasma electrons are first accelerated by the EM-wave fields and then collide with background-gas molecules, thereby transferring energy from the EM waves to the gas. A plasma absorber has several advantages compared to conventional materials. A plasma can be turned on and off very rapidly, thereby switching between absorbing and transparent conditions. Calculations indicate that plasma absorbers can also be tailored to provide broadband absorption (>40 dB) over multiple octaves. The authors have developed a one-dimensional model and a computer code to calculate the net power reflected from a plasma-enclosed EM-wave-reflecting target. They included three contributions to the reflected EM-wave power: reflections from the vacuum-plasma interface; reflections from the bulk plasma volume; and reflection of the attenuated EM wave that is transmitted through the plasma and reflected by the target

Dual emitter IrQ(ppy)2 for OLED applications: Synthesis and spectroscopic analysis

International Nuclear Information System (INIS)

Ciobotaru, I.C.; Polosan, S.; Ciobotaru, C.C.

2014-01-01

The synthesis of organometallic compound with iridium and two types of ligands, quinoline and phenylpyridine, was done successfully. The absorption spectra of this compound have shown broad peaks in a visible region assigned to metal-to-ligands charge transfer and in UV region assigned to intraligand absorptions. The photoluminescence spectra exhibit dual character in which the red emission is more intense than the green one. In cathodoluminescence measurements, under electron beam, the powder obtained after recrystallization from dichloromethane, shows similar behaviors with photoluminescence spectra. The cathodoluminescence images have shown a luminescent crystalline powder with triclinic structure. This compound exhibits combined vibrational modes, which proves the presence in the same molecule of both ligands. Density Functional Theory calculation was involved in order to identify the main vibrations of this compound. Highlights: • Mixed-ligand of IrQ(ppy) 2 synthesis which gives green and red phosphorescence due to the MCLT processes coming from two types of ligands. • Absorption, photoluminescence, infrared spectroscopy and cathodoluminescence measurements for characterization of IrQ(ppy) 2 organometallic compound. • Experimental results have been compared with the output files obtained from Density Functional Theory by using the Gaussian 03W software

The rapid mode of calcium uptake into heart mitochondria (RaM): comparison to RaM in liver mitochondria.

Science.gov (United States)

Buntinas, L; Gunter, K K; Sparagna, G C; Gunter, T E

2001-04-02

A mechanism of Ca(2+) uptake, capable of sequestering significant amounts of Ca(2+) from cytosolic Ca(2+) pulses, has previously been identified in liver mitochondria. This mechanism, the Rapid Mode of Ca(2+) uptake (RaM), was shown to sequester Ca(2+) very rapidly at the beginning of each pulse in a sequence [Sparagna et al. (1995) J. Biol. Chem. 270, 27510-27515]. The existence and properties of RaM in heart mitochondria, however, are unknown and are the basis for this study. We show that RaM functions in heart mitochondria with some of the characteristics of RaM in liver, but its activation and inhibition are quite different. It is feasible that these differences represent different physiological adaptations in these two tissues. In both tissues, RaM is highly conductive at the beginning of a Ca(2+) pulse, but is inhibited by the rising [Ca(2+)] of the pulse itself. In heart mitochondria, the time required at low [Ca(2+)] to reestablish high Ca(2+) conductivity via RaM i.e. the 'resetting time' of RaM is much longer than in liver. RaM in liver mitochondria is strongly activated by spermine, activated by ATP or GTP and unaffected by ADP and AMP. In heart, RaM is activated much less strongly by spermine and unaffected by ATP or GTP. RaM in heart is strongly inhibited by AMP and has a biphasic response to ADP; it is activated at low concentrations and inhibited at high concentrations. Finally, an hypothesis consistent with the data and characteristics of liver and heart is presented to explain how RaM may function to control the rate of oxidative phosphorylation in each tissue. Under this hypothesis, RaM functions to create a brief, high free Ca(2+) concentration inside mitochondria which may activate intramitochondrial metabolic reactions with relatively small amounts of Ca(2+) uptake. This hypothesis is consistent with the view that intramitochondrial [Ca(2+)] may be used to control the rate of ADP phosphorylation in such a way as to minimize the probability of

Investigation of influence of electronic irradiation on photoluminescence spectrum and ir-spectrum of porous silicon

International Nuclear Information System (INIS)

Daineko, E.A.; Dihanbayev, K.K.; Akhtar, P.; Hussain, A.

2007-01-01

In this article we study the influence of 2-Mev electron irradiation on porous silicon (PS). Photoluminescence (PL) spectrum and IR-spectrum have been done on both newly-prepared PS samples and samples prepared a year ago after the irradiation. We analyzed PL spectrum for both types of PS samples. The experimental results suggest that the peak position in PL spectrum decreases for newly-prepared PS samples. The size of the nanocrystals calculated by the method of singling out of spectrum components was equal to 3.0-3.2 nm. Porosity of the samples was 60-75%. From IR-spectrum of newly-prepared PS samples wide absorption band was observed at 1100 cm/sup -1/ (Si-O-Si bond). Another peak of Si-O-Si group was observed at 850 cm/sub -1/. Also hydrogen absorption bands were appearing from 2000 to 2200 cm/sup -1/, corresponding to vibration modes SiH, SiH/sub 2/, SiH/sub 3/. As a result of electron irradiation the PL intensity of newly-prepared PS samples decreases abruptly by a factor of 30 without peak shifting. As for the samples prepared a year ago we observed a decrease in the PL intensity by 25-30%. From IR-spectrum of PS samples prepared a year ago it was shown that the intensity of bridge bonds corresponding to absorption band 850 cm/sup -1/, decreases gradually. Our experimental data shows that PS samples stored for longer time have better radiation resistant properties than the newly-prepared PS samples due to the replacement of Si-H bonds with more resistant Si-O bonds. Porous silicon, electrochemical anodizing, photoluminescence spectrum, IR-spectrum, electronic irradiation. (author)

RA-0 reactor. New neutronic calculations; Reactor RA-0. Nuevos calculos neutronicos

Energy Technology Data Exchange (ETDEWEB)

Rumis, D; Leszczynski, F

1991-12-31

An updating of the neutronic calculations performed at the RA-0 reactor, located at the Natural, Physical and Exact Sciences Faculty of Cordoba National University, are herein described. The techniques used for the calculation of a reactor like the RA-0 allows prediction in detail of the flux behaviour in the core`s interior and in the reflector, which will be helpful for experiments design. In particular, the use of WIMSD4 code to make calculations on the reactor implies a novelty in the possible applications of this code to solve the problems that arise in practice. (Author). [Espanol] En este trabajo se actualizan los calculos neutronicos realizados para el reactor RA-0, instalado en la Facultad de Ciencias Exactas, Fisicas y Naturales de la Universidad Nacional de Cordoba. Se describen los calculos realizados hasta la fecha y los resultados obtenidos. Las tecnicas incorporadas al calculo de un reactor como el RA-0 permiten predecir en detalle el comportamiento del flujo en el interior del nucleo y en el reflector, lo que sera una importante ayuda en el diseno de experimentos. En particular, el empleo del codigo WIMSD4 para calculos del reactor completo constituye una novedad en las posibles aplicaciones de ese codigo para resolver problemas que se presentan en la practica. (Autor).

RA Research nuclear reactor - Annual report 1987

International Nuclear Information System (INIS)

1987-12-01

Annual report concerning the project 'RA research nuclear reactor' for 1987, financed by the Serbian ministry of science is divided into two parts. First part is concerned with RA reactor operation and maintenance, which is the task of the Division for reactor engineering of the Institute for multidisciplinary studies and RA reactor engineering. Second part deals with radiation protection activities at the RA reactor which is the responsibility of the Institute for radiation protection. Scientific council of the Institute for multidisciplinary studies and RA reactor engineering has stated that this report describes adequately the activity and tasks fulfilled at the RA reactor in 1989. The scope and the quality of the work done were considered successful both concerning the maintenance and reconstruction, as well as radiation protection activities [sr

Research nuclear reactor RA - Annual Report 1989

International Nuclear Information System (INIS)

Sotic, O.

1989-12-01

Annual report concerning the project 'RA research nuclear reactor' for 1989, financed by the Serbian ministry of science is divided into two parts. First part is concerned with RA reactor operation and maintenance, which is the task of the Division for reactor engineering of the Institute for multidisciplinary studies and RA reactor engineering. Second part deals with radiation protection activities at the RA reactor which is the responsibility of the Institute for radiation protection. Scientific council of the Institute for multidisciplinary studies and RA reactor engineering has stated that this report describes adequately the activity and tasks fulfilled at the RA reactor in 1989. The scope and the quality of the work done were considered successful both concerning the maintenance and reconstruction, as well as radiation protection activities [sr

Productivity loss due to absenteeism and presenteeism by different instruments in patients with RA and subjects without RA

NARCIS (Netherlands)

Braakman-Jansen, Louise Marie Antoinette; Kuper, Ina H.; van de Laar, Mart A F J; Taal, Erik

2012-01-01

Objectives. To explore the impact of at-work productivity loss on the total productivity cost by different instruments in patients recently diagnosed with RA and controls without RA. Methods. Cross-sectional data were collected from outpatients with RA between December 2007 and February 2008. The

Intraocular light scatter, reflections, fluorescence and absorption: what we see in the slit lamp.

Science.gov (United States)

van den Berg, Thomas J T P

2018-01-01

Much knowledge has been collected over the past 20 years about light scattering in the eye- in particular in the eye lens- and its visual effect, called straylight. It is the purpose of this review to discuss how these insights can be applied to understanding the slit lamp image. The slit lamp image mainly results from back scattering, whereas the effects on vision result mainly from forward scatter. Forward scatter originates from particles of about wavelength size distributed throughout the lens. Most of the slit lamp image originates from small particle scatter (Rayleigh scatter). For a population of middle aged lenses it will be shown that both these scatter components remove around 10% of the light from the direct beam. For slit lamp observation close to the reflection angles, zones of discontinuity (Wasserspalten) at anterior and posterior parts of the lens show up as rough surface reflections. All these light scatter effects increase with age, but the correlations with age, and also between the different components, are weak. For retro-illumination imaging it will be argued that the density or opacity seen in areas of cortical or posterior subcapsular cataract show up because of light scattering, not because of light loss. NOTES: (1) Light scatter must not be confused with aberrations. Light penetrating the eye is divided into two parts: a relatively small part is scattered, and removed from the direct beam. Most of the light is not scattered, but continues as the direct beam. This non-scattered part is the basis for functional imaging, but its quality is under the control of aberrations. Aberrations deflect light mainly over small angles (light scatter is important because of the straylight effects over large angles (>1°), causing problems like glare and hazy vision. (2) The slit lamp image in older lenses and nuclear cataract is strongly influenced by absorption. However, this effect is greatly exaggerated by the light path lengths concerned. This

Seasonal changes in submarine groundwater discharge to coastal salt ponds estimated using 226Ra and 228Ra as tracers

Science.gov (United States)

Hougham, A.L.; Moran, S.B.; Masterson, J.P.; Kelly, R.P.

2008-01-01

Submarine groundwater discharge (SGD) to coastal southern Rhode Island was estimated from measurements of the naturally-occurring radioisotopes 226Ra (t1/2 = 1600??y) and 228Ra (t1/2 = 5.75??y). Surface water and porewater samples were collected quarterly in Winnapaug, Quonochontaug, Ninigret, Green Hill, and Pt. Judith-Potter Ponds, as well as nearly monthly in the surface water of Rhode Island Sound, from January 2002 to August 2003; additional porewater samples were collected in August 2005. Surface water activities ranged from 12-83??dpm 100??L- 1 (60??dpm = 1??Bq) and 21-256??dpm 100??L- 1 for 226Ra and 228Ra, respectively. Porewater 226Ra activities ranged from 16-736??dpm 100??L- 1 (2002-2003) and 95-815??dpm 100??L- 1 (2005), while porewater 228Ra activities ranged from 23-1265??dpm 100??L- 1. Combining these data with a simple box model provided average 226Ra-based submarine groundwater fluxes ranging from 11-159??L m- 2 d- 1 and average 228Ra-derived fluxes of 15-259??L m- 2 d- 1. Seasonal changes in Ra-derived SGD were apparent in all ponds as well as between ponds, with SGD values of 30-472??L m- 2 d- 1 (Winnapaug Pond), 6-20??L m- 2 d- 1 (Quonochontaug Pond), 36-273??L m- 2 d- 1 (Ninigret Pond), 29-76??L m- 2 d- 1 (Green Hill Pond), and 19-83??L m- 2 d- 1 (Pt. Judith-Potter Pond). These Ra-derived fluxes are up to two orders of magnitude higher than results predicted by a numerical model of groundwater flow, estimates of aquifer recharge for the study period, and values published in previous Ra-based SGD studies in Rhode Island. This disparity may result from differences in the type of flow (recirculated seawater versus fresh groundwater) determined using each technique, as well as variability in porewater Ra activity. ?? 2007 Elsevier B.V. All rights reserved.

226Ra, 228Ra and 40K in scales formed in boilers of industrial installations

International Nuclear Information System (INIS)

Poggi, Claudia M. Braga; Farias, Emerson Emiliano G. de; Hazin, Clovis A.; Gazineu, Maria Helena P.; Universidade Catolica de Pernambuco

2011-01-01

Many industrial processes involve the production of steam in boilers, which is sent through pipes to machines and other equipment used in different sectors of the installations. The water commonly used in these processes is groundwater, which generally has high concentrations of calcium and magnesium salts, that can co-precipitate with naturally occurring radioactive elements such as 226 Ra and 228 Ra creating radioactive scales, which are deposited in pipes, thus decreasing the efficiency of steam production. In addition, 40 K that is present in all soils and rocks with a concentration of about 0.012% of natural potassium can also be concentrated in these scales. No data was found in literature relating to radionuclides present in the scales formed on boilers in general. In this context, the purpose of this work was to determine concentrations of 226 Ra, 228 Ra and 40 K, in scales generated inside boilers from different industries in the cities of Caruaru, Paulista and Goiana, Pernambuco. Determination of the radionuclides concentration was performed by gamma spectrometry with an HPGe detector, calculating their specific activities. Activity concentrations of 226 Ra were in the range of -1 and 228 Ra activity concentrations varied from 1 . Activity concentrations of 40 K were in the range of -1 . All these activity concentrations were lower than the limits established by the Brazilian Nuclear Energy Commission of for this type of matrix. (author)

New IR-UV gas sensor to energy and transport sector

Energy Technology Data Exchange (ETDEWEB)

Fateev, A.; Clausen, S.

2010-12-15

In situ simultaneous measurements of gas temperature and gas composition are of great interest in combustion research and give useful information about conditions, chemical reactions and gas mixing in many industrial processes. An optically based technique is beneficial because it is non-intrusive, accurate, fast and can be performed in situ for various extremely hard conditions. In humid and hot gas flows UV technique is more sensitive than FTIR one for fast gas concentration measurements of NO and SO{sub 2} and gives a great opportunity for simultaneous measurements of O{sub 2} concentration. Analysis of the fine structure of the UV absorption bands of, for example, NO, SO{sub 2} or O{sub 2} allows also to determine a value of the gas temperature. Absorption cross sections of CO{sub 2}, H{sub 2}O and SO{sub 2} measured using Risoe DTU's hot gas cell facility at elevated temperatures up to 1500 deg. C are reported. Design of a new developed 9-m long water-cooled fiber-optic probe with removable optical head suitable for fast IR/UV local gas absorption/emission measurements is described. The probe performance was successfully tested in several trial measurements on full scale multi-fuel fired boiler. A concept of fast time/spectralresolved measurements has been used in measurements on a large ship engine based on IR and UV broad band spectroscopy. (Author)

Seasonal variation of 228Ra/226Ra ratio in seaweed: implications for water circulation patterns in coastal areas of the Noto Peninsula, Japan

International Nuclear Information System (INIS)

Inoue, M.; Kofuji, H.; Yamamoto, M.; Komura, K.

2005-01-01

To examine water circulation patterns of coastal water, 72 seaweed (Sargasso) samples and 27 coastal water samples were collected from coastal areas of the Noto Peninsula, Japan, during the period from December 1998 to June 2002. The 228 Ra and 226 Ra activities of those samples were measured by low-background γ-ray spectrometry. There was a wide range of activities of 228 Ra (0.5-2 Bq/kg-fresh) and 226 Ra (0.5-1.2 Bq/kg-fresh) in the Sargasso samples. The 228 Ra/ 226 Ra activity ratio of Sargasso samples exhibited seasonal variation with minimum values in June ( 228 Ra/ 226 Ra = ∼1) and maximum values in December (1.5-2.5), which was mainly governed by changes in 228 Ra activity. It is also notable that the seasonal variation of the 228 Ra/ 226 Ra ratio of Sargasso is in approximate agreement with that of the ambient coastal water. Sargasso samples appear to have retained the 228 Ra/ 226 Ra ratio of the ambient coastal waters, and the temporal variations in that ratio provide insight into seasonal changes in water circulation in the Noto Peninsula coastal area

On the origin of reflectance-anisotropy oscillations during GaAs (0 0 1) homoepitaxy

Science.gov (United States)

Ortega-Gallegos, J.; Guevara-Macías, L. E.; Ariza-Flores, A. D.; Castro-García, R.; Lastras-Martínez, L. F.; Balderas-Navarro, R. E.; López-Estopier, R. E.; Lastras-Martínez, A.

2018-05-01

We report on the first spectroscopic study of reflectance-anisotropy (RA) oscillations during molecular beam epitaxy (MBE) GaAs homoepitaxy. Real-time RA spectra measured during epitaxial growth were carried out with a recently developed rapid RA multichannel spectrometer with 100 ms per spectrum acquisition time. An analysis of the time-resolved RA spectra shows that RA oscillations are mostly due to the periodic modulation of the surface orthorhombic strain associated to surface reconstruction. Results reported here demonstrate the power of real-time RA spectroscopy as a probe for the study of epitaxial growth processes. In particular, given its sub monolayer surface-strain sensitivity, RA spectroscopy results a very convenient tool to study epitaxial growth mechanisms in real-time with sub monolayer resolution. This capability allows for real-time RA spectroscopy to be used as a probe for the in situ, real-time control of epitaxial growth, with the additional advantage of operating in higher pressure systems such as CVD, where RHEED monitoring cannot be implemented.

Research nuclear reactor RA - Annual Report 1996; Istrazivacki nuklearni reaktor RA - Izvestaj za 1996. godinu

Energy Technology Data Exchange (ETDEWEB)

Sotic, O [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1996-12-01

Activities related to revitalisation of the RA reactor started in 1986, were continued in 1996. All the planned actions related to renewal of the reactor components were finished. The last, and at the same time most important action, related to exchange of complete reactor instrumentation is underway, delayed. The delivery of components from USSR is late. Production of this instruments is financed by the IAEA according to the contract signed in December 1988 with Russian Atomenergoexport. According to this contract, it has been planned that the RA reactor instrumentation should be delivered to the Vinca Institute by the end of 1990. Only 80% of the instrumentation was delivered until September 1991. Since then any delivery of components to Yugoslavia was stopped because of the temporary embargo imposed by the IAEA. The existing RA reactor instrumentation was dismantled. Control and maintenance of the reactor components was done regularly and efficiently. Fuel inspection by the IAEA safeguards inspectors was done on a monthly basis. There have been on the average 43 employees at the RA reactor which is considered sufficient for maintenance and repair conditions. The problem of financing the reactor activities and maintenance remains unsolved. Research reactor RA Annual report for year 1996 is divided into two main parts to cover: (1) operation and maintenance and (2) activities related to radiation protection. [Serbo-Croat] U toku 1996. godine nastavljeni su poslovi na revitalizaciji reaktora RA, zapocetoj 1986. godine. Okoncan je niz zahvata na opremi postrojenja kojima ce se u narednom periodu omoguciti kontinualan i pouzdan rad ovog reaktora. Poslednji, i ujedno najveci zahvat, koji se odnosi na zamenu celokupne instrumentacije kasni zbog zastoja u isporuci opreme koja se izradjuje u Sovjetskom savezu. Izradu ove opreme finansira Medjunarodna agencija za atomsku energiju kroz ugovor sklopljen decembra 1988. godine sa moskovskom firmom Atomenergoexport. Prema tom

Structure, magnetism, and transport properties for Ca doping in Sr2IrO4

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Guotai Zhou

2017-05-01

Full Text Available An immediate quenching using liquid N2 is applied for synthesizing the 5d transition-metal oxides (Sr1-xCax2IrO4 (0 ≤ x ≤ 0.15 single phase. X-ray diffraction together with Rietveld refinement shows that the lattice parameters along a and c directions and the bond angle of Ir-O2-Ir decrease with the increase of Ca content. X-ray Absorption Fine Spectroscopy measurements prove that the valence of Ir and the average Ir-O bond-length substantially remain unchanged with Ca content increasing in the phase. The effective magnetic moment μeff and Néel temperature TN decrease simultaneously with increased Ca content. Electrical resistivity shows complex temperature dependence behavior, which follows the three-dimensional variable range hopping behavior at low temperature, Arrhenius-type behavior at middle-temperature, and a weak electronic localization in quasi-two-dimensional at high temperature.

Single-crystal films of a combination of materials (co-crystal) involving DAST and IR-125 for electro-optic applications

Science.gov (United States)

Narayanan, A.; Titus, J.; Rajagopalan, H.; Vippa, P.; Thakur, M.

2006-03-01

Single-crystal film of DAST (4'-dimethylamino-N-methyl-4-stilbazolium tosylate) has been shown [1] to have exceptionally large electro-optic coefficients (r11 ˜ 770 pm/V at 633 nm). In this report, single crystal film of a combination of materials (co-crystal) involving DAST and a dye molecule IR-125 will be discussed. Modified shear method was used to prepare the co-crystal films. The film has been characterized using polarized optical microscopy, optical absorption spectroscopy and x-ray diffraction. The optical absorption spectrum has two major bands: one at about 350--600 nm corresponding to DAST and the other at about 600-900 nm corresponding to IR-125. The x-ray diffraction results show peaks involving the presence of DAST and IR-125 within the co-crystal film. Since the co-crystal has strong absorption at longer wavelengths it is expected to show higher electro-optic coefficients at longer wavelengths. Preliminary measurements at 1.55 μm indicate a high electro-optic coefficient of the co-crystal film. [1] Swamy, Kutty, Titus, Khatavkar, Thakur, Appl. Phys. Lett. 2004, 85, 4025; Kutty, Thakur, Appl. Phys. Lett. 2005, 87, 191111.

Measurements of neutron flux in the RA reactor

International Nuclear Information System (INIS)

Raisic, N.

1961-12-01

This report includes the following separate parts: Thermal neutron flux in the experimental channels od RA reactor; Epithermal neutron flux in the experimental channels od RA reactor; Fast neutron flux in the experimental channels od RA reactor; Thermal neutron flux in the thermal column and biological experimental channel; Neutronic measurements in the RA reactor cell; Temperature reactivity coefficient of the RA reactor; design of the device for measuring the activity of wire [sr

Sensing Properties of Multiwalled Carbon Nanotubes Grown in MW Plasma Torch: Electronic and Electrochemical Behavior, Gas Sensing, Field Emission, IR Absorption

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Petra Majzlíková

2015-01-01

Full Text Available Vertically aligned multi-walled carbon nanotubes (VA-MWCNTs with an average diameter below 80 nm and a thickness of the uniform VA-MWCNT layer of about 16 µm were grown in microwave plasma torch and tested for selected functional properties. IR absorption important for a construction of bolometers was studied by Fourier transform infrared spectroscopy. Basic electrochemical characterization was performed by cyclic voltammetry. Comparing the obtained results with the standard or MWCNT‑modified screen-printed electrodes, the prepared VA-MWCNT electrodes indicated their high potential for the construction of electrochemical sensors. Resistive CNT gas sensor revealed a good sensitivity to ammonia taking into account room temperature operation. Field emission detected from CNTs was suitable for the pressure sensing application based on the measurement of emission current in the diode structure with bending diaphragm. The advantages of microwave plasma torch growth of CNTs, i.e., fast processing and versatility of the process, can be therefore fully exploited for the integration of surface-bound grown CNTs into various sensing structures.

Modeling of the Dynamics of Radio Wave Reflection and Absorption in a Smoothly Ionomogeneous Plasma with Electromagnetically Driven Strong Langmuir Turbulence

Science.gov (United States)

Kochetov, A. V.

2018-05-01

This work was initiated by experiments on studying the self-action of radio waves incident on the ionosphere from a ground-based transmitter at the stage of electromagnetic excitation of Langmuir turbulence (Langmuir effect). The emphasis is on the impact of "self-consistent" collisionless absorption of radio waves by the Langmuir turbulence, which develops when the incident-wave field swells in the resonant region of a smoothly inhomogeneous plasma, on the dynamics of the radio wave reflection. Electrodynamic characteristics of the nonlinear-plasma layer, which has a linear unperturbed profile of the plasma density, with different features of the absorption development are obtained for a high intensity of the incident radiation. Calculations of "soft" and "hard" regimes of the absorption occurrence, as well as hysteresis modes in which the damping switch-on and off thresholds differ several times, are carried out. The algorithms we devised and the results of the study can serve as the basis for a more adequate and more detailed numerical simulation for interpretation of the experimental data obtained at the stage of the Langmuir effect in the ionosphere.

Water vapor retrieval from near-IR measurements of polarized scanning atmospheric corrector

Science.gov (United States)

Qie, Lili; Ning, Yuanming; Zhang, Yang; Chen, Xingfeng; Ma, Yan; Li, Zhengqiang; Cui, Wenyu

2018-02-01

Water vapor and aerosol are two key atmospheric factors effecting the remote sensing image quality. As water vapor is responsible for most of the solar radiation absorption occurring in the cloudless atmosphere, accurate measurement of water content is important to not only atmospheric correction of remote sensing images, but also many other applications such as the study of energy balance and global climate change, land surface temperature retrieval in thermal remote sensing. A multi-spectral, single-angular, polarized radiometer called Polarized Scanning Atmospheric Corrector (PSAC) were developed in China, which are designed to mount on the same satellite platform with the principle payload and provide essential parameters for principle payload image atmospheric correction. PSAC detect water vapor content via measuring atmosphere reflectance at water vapor absorbing channels (i.e. 0.91 μm) and nearby atmospheric window channel (i.e. 0.865μm). A near-IR channel ratio method was implemented to retrieve column water vapor (CWV) amount from PSAC measurements. Field experiments were performed at Yantai, in Shandong province of China, PSAC aircraft observations were acquired. The comparison between PSAC retrievals and ground-based Sun-sky radiometer measurements of CWV during the experimental flights illustrates that this method retrieves CWV with relative deviations ranging from 4% 13%. This method retrieve CWV more accurate over land than over ocean, as the water reflectance is low.

Seasonal variations in 228Ra/226Ra ratio within coastal waters of the Sea of Japan: implications for water circulation patterns in coastal areas

International Nuclear Information System (INIS)

Inoue, M.; Tanaka, K.; Watanabe, S.; Kofuji, H.; Yamamoto, M.; Komura, K.

2006-01-01

In this study, low-background γ-spectrometry was used to determine the 228 Ra/ 226 Ra ratio of 131 coastal water samples from various environments around Honshu Island, Japan (mainly around Noto Peninsula) at 1-3 month intervals from April 2003 until September 2005. Spatial variation in 228 Ra/ 226 Ra ratios was also assessed by analyzing 34 coastal water samples from five areas within the Sea of Japan during May and June 2004. The 228 Ra/ 226 Ra ratio of coastal water from all sites around Noto Peninsula shows seasonal variation, with minimum values during summer ( 228 Ra/ 226 Ra = 0.7) and maximum values during autumn-winter ( 228 Ra/ 226 Ra = 1.7-2). This seasonal variation is similar to that recorded for coastal water between Tsushima Strait and Noto Peninsula. The measured lateral variation in 228 Ra/ 226 Ra ratios within coastal water between Tsushima Strait and Noto Peninsula is only minor (0.5-0.7; May-June 2004). Coastal waters from two other sites (Pacific shore and Tsugaru Strait, north Honshu) show no clear seasonal variation in 228 Ra/ 226 Ra ratio. These measured variations in 228 Ra/ 226 Ra ratio, especially the temporal variations, have important implications for seasonal changes in patterns of coastal water circulation within the Sea of Japan

Rapid intra-operative diagnosis of kidney cancer by attenuated total reflection infrared spectroscopy of tissue smears.

Science.gov (United States)

Pucetaite, Milda; Velicka, Martynas; Urboniene, Vidita; Ceponkus, Justinas; Bandzeviciute, Rimante; Jankevicius, Feliksas; Zelvys, Arunas; Sablinskas, Valdas; Steiner, Gerald

2018-01-09

Herein, a technique to analyze air-dried kidney tissue impression smears by means of attenuated total reflection infrared (ATR-IR) spectroscopy is presented. Spectral tumor markers-absorption bands of glycogen-are identified in the ATR-IR spectra of the kidney tissue smear samples. Thin kidney tissue cryo-sections currently used for IR spectroscopic analysis lack such spectral markers as the sample preparation causes irreversible molecular changes in the tissue. In particular, freeze-thaw cycle results in degradation of the glycogen and reduction or complete dissolution of its content. Supervised spectral classification was applied to the recorded spectra of the smears and the test spectra were classified with a high accuracy of 92% for normal tissue and 94% for tumor tissue, respectively. For further development, we propose that combination of the method with optical fiber ATR probes could potentially be used for rapid real-time intra-operative tissue analysis without interfering with either the established protocols of pathological examination or the ordinary workflow of operating surgeon. Such approach could ensure easier transition of the method to clinical applications where it may complement the results of gold standard histopathology examination and aid in more precise resection of kidney tumors. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

TG/FT-IR characterization of additives typically employed in EPDM formulations

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Natália Beck Sanches

2015-06-01

Full Text Available AbstractThermogravimetric analysis coupled to Fourier transform infrared spectroscopy (TG/FT-IR is a very popular technique for rubbers characterization. It involves analyses of the base polymer and additives. Ethylene–propylene–diene (EPDM rubbers are frequently investigated by TG/FT-IR; however, the focus has been the degradation temperature range of the polymer. In this study, unvulcanized and vulcanized EPDM rubber and its additives were investigated by TG/FT-IR, without solvent extraction, and in a wide temperature range. Initially, the additives were individually characterized. TG/FT-IR identified the characteristic groups of all the additives analyzed and distinguished them from each other. Afterwards, unvulcanized and vulcanized EPDM rubbers were investigated without prior extraction.TG/FT-IR detected absorptions due to the additives tetramethylthiuram monosulfide and 2-mercaptobenzothiazole. Both of these sulfur-containing additives were present in the EPDM formulation at concentrations of 0.7 phr (0.63 wt %. The TG/FT-IR technique had some limitations, because not all the additives in EPDM rubber were detected. Paraffin oil, stearic acid and 2,2,4-trimethyl-1,2-dihydroquinoline functional groups were not observed in either the unvulcanized or vulcanized EPDM. Nevertheless, in addition to the ability of this method to detect sulfur-containing groups, the lack of a pre-extraction reduces the time and effort required for additive analysis in rubbers.

Absorção e infiltração de água por raízes de batata-doce, através de ferimentos durante a lavagem Water absorption and infiltration in sweet-potato wound roots during washing

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Adonai Gimenez Calbo

2000-09-01

Full Text Available Raízes intactas e segmentos transversais de batata-doce (Ipomea batatas L. Lam foram totalmente ou parcialmente imersos em água. Raízes ou segmentos parcialmente imersos ficaram com menos de 10% da superfície externa fora da água, em um suspiro. Nestes ensaios a pressão da atmosfera interna das raízes parcialmente imersas manteve-se apenas alguns milímetros inferior a pressão atmosférica. Nas raízes totalmente imersas a pressão reduziu-se quase linearmente até mais de 1m de coluna de água e depois voltou a aumentar lentamente. Nas raízes intactas ou nos seus segmentos transversais totalmente imersos, houve maior infiltração de água nos volumes intercelulares do que nas raízes ou segmentos parcialmente imersos. Nas raízes intactas praticamente houve apenas absorção de água através das paredes e membranas celulares. Nos segmentos a infiltração de água através dos volumes intercelulares foi dominante. Considerando-se as dimensões transversais dos volumes intercelulares, sugere-se que partículas como bactérias e esporos possam ser arrastados para o interior órgão pela infiltração de água durante a lavação dos tecidos mecânicamente danificados.Intact roots and transversal root segments of sweet-potato (Ipomea batatas L. Lam were partially or completely submerged in water. In partially submerged roots less than 10% of the dermal surface remained exposed to air through a vent. Internal atmosphere pressure in partially submerged roots remained a few millimeters bellow the atmospheric pressure, while a much larger and nearly linear pressure reduction occurred in completely submerged roots. This linear phase caused a pressure reduction larger than 1m of water column. After that, the pressure started to rise slowly. The observed pressure reduction was smaller than the one observed in the constant pressure manometry procedure where the roots were sealed with epoxy resin, which precluded any water infiltration and

Study the multi-photon absorption process in two types of molecules

International Nuclear Information System (INIS)

Al-azawi, H.R.

1986-01-01

The aim of the present work was to study the multi-photon absorption process in two types of molecules; spherical top such as SF 6 molecules and assymetric top such as CHOOH and C 2 H 4 molecules. This work also aimed to study the effect of buffer gas pressure (Ar), which is transparent to the infrared (IR) laser on the multiphoton absorption of both types of molecules. A pulsed (TEA) CO 2 laser was used as a source which generates multi-lines in the IR-region of the spectrum and an optoacoustic detector was used to detect the energy absorbed by the molecules. In this study, the relaxation process was found to be faster in the heavy molecules than that in the light ones. A limit in the Ar pressure was observed. Below this limit, the gas acted as an active buffer gas and above it, the multi-photon absorption process was quenched. This work also aimed to study the multi-photon absorption spectrum for the CHOOH molecules in the range (1067-1090 cm -1 ). This spectrum was found to be consistent with the linear absorption spectrum obtained for the same range. The density of the vibrational states as a function of the vibrational energy was studied for the molecules SF 6 , CHOOH and C 2 H 4 . The results were used to interpret (i) the difference in the energy absorbed by difference molecules at the same energy density and (ii) the non-linearity in the multi-photon absorption for CHOOH molecules. 1 tab.; 40 figs.; 70 refs

Editorial. Kultūros reiškiniai šiuolaikinių informacijos ir komunikacijos technologijų sąlygomis: nuo meno ir televizijos iki politikos

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Jovilė Barevičiūtė

2015-10-01

Full Text Available Šiame žurnalo numeryje aptariami kai kurie daugiaaspekčiai šiuolaikinės kultūros reiškiniai, apimant tokius jų, kaip menas, televizija, politika ir kt. Medijos ir komunikacija nūdien intensyviai skverbiasi kone į visas darbo ir laisvalaikio veiklos, viešojo ir privataus sektorių sritis, reprezentuodamos dinamišką ir netolygią gyvenamojo pasaulio tikrovę. Medijuotoji komunikacija vis labiau tampa dominuojančia socializacijos forma, ji išstumia gyvąją komunikaciją: kuo toliau, tuo labiau šis reiškinys nusako ne tik jaunimo, bet ir brandaus amžiaus žmonių šiandienį bendravimo būdą. Tad akivaizdu, kad XXI a. žmogus vis labiau pasineria į įvairių medijų tinklus, apraizgančius jo gyvenimą ir tampančius pagrindine socialios ir visavertės eg zistencijos sąlyga. Tokios socialinės institucijos, kaip menas, televizija, politika, religija, šeima ir daugelis kitų, nūdien jau nebėra tokios savarankiškos, kaip, tarkime, prieš dešimt, dvidešimt ar daugiau metų. Jų suverenitetą daugiausia transformuoja būtent medijos, šioms institucijoms diktuojančios savas sąlygas ir primetančios savas taisykles. Kitaip tariant, medijos tampa tokios galingos, kad ima steigti savuosius dėsnius, kuriems vis labiau paklūsta tradicinė gyvosios socializacijos aplinka. Taip kyla daugybė diskutuotinų ir ginčytinų klausimų, paliečiančių socialinių institucijų apibrėžties, autonomijos ir suvereniteto aspektus. Šiuos aspektus iš įvairių perspektyvų gvildena ir šio numerio autoriai. Eugenija Krukauskienė ir Viktorija Žilinskaitė-Vytienė savo straipsnyje aptaria kultūros vartojimo klausimus tirdamos, kaip šiuolaikinio lietuviškojo kino meno pavyzdžius suvokia ir vertina tam tikrų amžiaus kategorijų jaunimas. Algis Mickūnas gilinasi į filosofinius šiuolaikinių diskursų klausimus, pasirinkdamas kūniškumo, lytėjimo ir taktilikos aspektus, glaudžiai susijusius su medijuotosios komunikacijos tema

A novel application of reactive absorption to break the CO2–ethane azeotrope with low energy requirement

International Nuclear Information System (INIS)

Tavan, Yadollah; Hosseini, Seyyed Hossein

2013-01-01

Highlights: • Investigation of RA for the CO 2 –ethane azeotropic process using Hysys simulator. • Optimization of operating parameters to minimize energy demand in the proposed RA process. • Superior performance of the RA process compared to the conventional process. • Enhance in NGL production from 795 to 1120 mole/s compared to the conventional process. - Abstract: Azeotropic separation of ethane and CO 2 using reactive absorption (RA) is studied by Hysys process software. A new configuration of a RA process is proposed using diethanolamine (DEA) to break the azeotrope. Impacts of amine flow rate, amine inlet temperature and feed–inlet location are investigated to achieve an optimum condition of the process in terms of energy demand. The simulation results show that optimum values of amine flow rate, amine temperature and feed–inlet location are 1900 mole/s, 30 °C and 20th stage, respectively. It is found that the process including RA leads to a significant reduction in operating costs, compared to the conventional extractive process

Using 226Ra/228Ra disequilibrium to determine the residence half-lives of radium in vegetation compartments

International Nuclear Information System (INIS)

Baeza, A.; Barandica, J.; Paniagua, J.M.; Rufo, M.; Sterling, A.

1999-01-01

The concentrations of 226 Ra and 228 Ra were studied in different vegetation compartments and in available and non-available soil fractions in a Mediterranean scrubland ecosystem. A high percentage of the plant samples showed an apparent discrimination in favour of 226 Ra over 228 Ra. A linear compartmental model was applied to the soil-plant system. It allowed us to explain why these discrimination coefficients differed from unity, to obtain the residence half-lives of radium in the different compartments, to estimate the age of the plants, and to simulate the temporal evolution of the radioactive concentrations in each compartment. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

IL-1Ra: its role in rheumatoid arthritis

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M. Cutolo

2011-09-01

Full Text Available Interleukin-1 (IL-1 is one of the pivotal cytokines in initiating and driving the processes of rheumatoid arthritis (RA, and the body’s natural response, IL-1 receptor antagonist (IL-1Ra, has been shown conclusively to block its effects. IL-1 mediate several clinical symptoms of the inflammatory reaction (i.e. fever, pain, sleep disturbances. IL-1 is considered a key mediator in RA joint damage because of its greater capacity (greater than TNF of increasing matrix degradation by inducing the production of MMPs and PGE2 in synovial cells, as well by its role as mediator of bone and cartilage destruction. In addition, IL-1 decreases the repair process by suppressing matrix synthesis and shows a strong synergism with TNF in inducing many inflammatory genes at both local and systemic level. The induced endogenous production of IL-1Ra, in presence of the RA synovitis, is too low to contrast the high affinity of IL-1 for the cell receptors. Therefore, IL-1Ra presence should result in very effective prevention of IL-1 signal transduction particularly in the inflammatory site. In laboratory and animal studies inhibition of IL-1 by either antibodies to IL-1 or IL-1Ra proved beneficial to the outcome. IL-1Ra is a member of the IL-1 superfamily. The effects of different DMARDs on IL-1Ra levels in RA patients support the important role that selected anticytokine treatments might exert in the pathophysiology of the disease. However, since anti TNFα therapy it is not effective in all RA patients, nor does it fully control the arthritic process in affected joints of good responders and complete TNF suppression should be avoided, the combined treatment with intermediate doses of TNF and IL-1 blockers, reaching synergistic suppression of arthritis, seems warranted in RA.

Mid IR-fiber spectroscopy in the 2-17μm range

Science.gov (United States)

Artyushenko, Viatcheslav G.; Bocharnikov, A.; Colquhoun, Gary; Leach, Clive A.; Lobachov, Vladimir; Pirogova, Lyudmila; Sakharova, Tatjana; Savitskij, Dmitrij; Ezhevskaya, Tatjana; Bublikov, Alexandr

2007-10-01

The latest development in IR-fibre optics enables us to expand the spectral range of process spectroscopy from 2μm out to 17μm (5000 to 600cm-1) i.e. into the most informative "finger-print" part of the spectrum. Mid-IR wavelength ranges from 2 to 6-10μm may be covered by Chalcogenide IR-glass CIR-fibres while Polycrystalline PIR-fibres made of Silver Halides solid solutions transmit 4-17 μm wavelength radiation. PIR-fibre immersion ATR probes and Transmission/Reflection probes had been manufactured and successfully tested with different FTIR spectrometers in the field of remote spectroscopy for forensic substances identification, chemical reaction control, and monitoring of exhaust or exhalation gases. Using these techniques no sample preparation is necessary for fibre probes to measure evanescent, reflection and transmission spectra, in situ and in real time. QCL spectrometer may be used as a portable device for multispectral gas analysis at 1ppb level of detectivity for various applications in environmental pollution monitoring.

Far-IR measurements at Cerro Toco, Chile: FIRST, REFIR, and AERI

Science.gov (United States)

Cageao, Richard P.; Alford, J. Ashley; Johnson, David G.; Kratz, David P.; Mlynczak, Martin G.

2010-09-01

In mid-2009, the Radiative Heating in the Underexplored Bands Campaign II (RHUBC-II) was conducted from Cerro Toco, Chile, a high, dry, remote mountain plateau, 23°S , 67.8°W at 5.4km, in the Atacama Desert of Northern Chile. From this site, dominant IR water vapor absorption bands and continuum, saturated when viewed from the surface at lower altitudes, or in less dry locales, were investigated in detail, elucidating infrared (IR) absorption and emission in the atmosphere. Three Fourier Transform InfraRed (FTIR) instruments were at the site, the Far-Infrared Spectroscopy of the Troposphere (FIRST), the Radiation Explorer in the Far Infrared (REFIR), and the Atmospheric Emitted Radiance Interferometer (AERI). In a side-by-side comparison, these measured atmospheric downwelling radiation, with overlapping spectral coverage from 5 to 100μm (2000 to 100cm-1), and instrument spectral resolutions from 0.5 to 0.643cm-1, unapodized. In addition to the FTIR and other ground-based IR and microwave instrumentation, pressure/temperature/relative humidity measuring sondes, for atmospheric profiles to 18km, were launched from the site several times a day. The derived water vapor profiles, determined at times matching the FTIR measurement times, were used to model atmospheric radiative transfer. Comparison of instrument data, all at the same spectral resolution, and model calculations, are presented along with a technique for determining adjustments to line-by-line calculation continuum models. This was a major objective of the campaign.

Estimation of annual effective dose from 226Ra and 228Ra due to consumption of foodstuffs by inhabitants of Ramsar city, Iran

International Nuclear Information System (INIS)

Asefi, M.; Fathivand, A. A.; Amidi, J.

2005-01-01

226 Ra and 228 Ra contents in foodstuffs of Ramsar which is a coastal city in the northern part of lran were determined by gamma spectrometry. Measurement results together with food consumption rates were used to estimate annual effective dose from 226 Ra and 228 Ra, due to consumption of food stuffs by inhabitants of Ramsar city. Materials and methods: a total of 33 samples from 11 different foodstuffs including root vegetables (beetroot), leafy vegetables (lettuce, parsley and spinach) and tea, meat, chicken, pea, broad bean, rice, and cheese were purchased from markets of Ramsar city and were analyzed for their 226 Ra and 228 Ra concentration. 1-8 kg of fresh weight sample was placed in Marinnelli beaker and sealed. The measurement of natural radioactivity levels as performed by gamma-spectrometry system, using a high purity germanium detector with 40% relative efficiency. Results: The highest concentrations of 226 Ra and 228 Ra were determined in tea samples with 1570 and 1140 mBq/kg, respectively, and the lowest concentration of 226 Ra was in pea, cheese, chicken, broad bean, and beetroot. Conclusion:The maximum estimated annual effective dose from 226 Ra and 228 Ra due to consumption, foodstuffs were determined to be 19.22 and 0.71 mSv from rice and meat samples respectively, where as, minimum estimated annual effective dose for 226 Ra was 0.017, 0.018 and 0.019 mSv from beetroot, cheese and pea samples respectively

Determination of long-lived natural Ra isotopes, 226Ra, in mineral and spring waters from Caxambu (MG) and Aguas de Lindoia (SP) spas

International Nuclear Information System (INIS)

Negrao, Sergio Garcia

2012-01-01

The aim of this work was to study the long-lived Ra isotopes, 226 Ra and 228 Ra, natural distribution in mineral and spring waters from Caxambu (MG) and Aguas de Lindoia (SP) water parks. In Caxambu mineral waters it was observed 228 Ra activity concentrations slightly higher than those of 226 Ra. The elevated content of carbonates and bicarbonates of these waters can result in an increased solubility of the both Ra isotopes and may play an important role for the fate of 228 Ra and its equilibrium distribution between solid and liquid phases. In Caxambu Thermal Spa, arithmetic mean activities ranged from 83 mBq L -1 to 3599 mBq L -1 and from 60 mBq L -1 to 4481 mBq L -1 for 226 Ra and 228 Ra, respectively. The highest 226 Ra activity was found in Venancio Spring, while the maximum 228 Ra activity value was determined in Ernestina Guedes. 228 Ra/ 226 Ra activity ratios varied from 0.079 (Conde D'Eau and Princesa Isabel Spring) to 4.2 (Mairink II Spring). In Aguas de Lindoia, arithmetic mean activities ranged from 4.6 mBq L -1 to 41 mBq L -1 and from 30 mBq L -1 to 54 mBq L -1 for 226 Ra and 228 Ra, respectively. The maximum 226 Ra activity concentration was found in the bottled mineral water Sao Jorge, while the higher 228 Ra activity concentration was determined in Santa Filomena Spring (public station 2). 228 Ra/ 226 Ra activity ratios varied from 1.2 (bottled mineral water Sao Jorge) to 9.1 (bottled mineral water Jatoba 1). This work also performed the dose assessment due to the ingestion of 226 Ra and 228 Ra in Caxambu and Aguas de Lindoia mineral and spring waters. The committed effective doses were estimated by using a conservative dosimetric model and taking into account the results over a lifetime (70 years) following intake of both long-lived Ra isotopes. The results from this radiological evaluation showed that the guidance committed effective dose level of 0.1 mSv y-1 recommended by World Health Organization was exceeded in almost all samples studied in

Moth eye-inspired anti-reflective surfaces for improved IR optical systems & visible LEDs fabricated with colloidal lithography and etching.

Science.gov (United States)

Chan, Lesley W; Morse, Daniel E; Gordon, Michael J

2018-05-08

Near- and sub-wavelength photonic structures are used by numerous organisms (e.g. insects, cephalopods, fish, birds) to create vivid and often dynamically-tunable colors, as well as create, manipulate, or capture light for vision, communication, crypsis, photosynthesis, and defense. This review introduces the physics of moth eye (ME)-like, biomimetic nanostructures and discusses their application to reduce optical losses and improve efficiency of various optoelectronic devices, including photodetectors, photovoltaics, imagers, and light emitting diodes. Light-matter interactions at structured and heterogeneous surfaces over different length scales are discussed, as are the various methods used to create ME-inspired surfaces. Special interest is placed on a simple, scalable, and tunable method, namely colloidal lithography with plasma dry etching, to fabricate ME-inspired nanostructures in a vast suite of materials. Anti-reflective surfaces and coatings for IR devices and enhancing light extraction from visible light emitting diodes are highlighted.

Forensic Hair Differentiation Using Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Spectroscopy.

Science.gov (United States)

Manheim, Jeremy; Doty, Kyle C; McLaughlin, Gregory; Lednev, Igor K

2016-07-01

Hair and fibers are common forms of trace evidence found at crime scenes. The current methodology of microscopic examination of potential hair evidence is absent of statistical measures of performance, and examiner results for identification can be subjective. Here, attenuated total reflection (ATR) Fourier transform-infrared (FT-IR) spectroscopy was used to analyze synthetic fibers and natural hairs of human, cat, and dog origin. Chemometric analysis was used to differentiate hair spectra from the three different species, and to predict unknown hairs to their proper species class, with a high degree of certainty. A species-specific partial least squares discriminant analysis (PLSDA) model was constructed to discriminate human hair from cat and dog hairs. This model was successful in distinguishing between the three classes and, more importantly, all human samples were correctly predicted as human. An external validation resulted in zero false positive and false negative assignments for the human class. From a forensic perspective, this technique would be complementary to microscopic hair examination, and in no way replace it. As such, this methodology is able to provide a statistical measure of confidence to the identification of a sample of human, cat, and dog hair, which was called for in the 2009 National Academy of Sciences report. More importantly, this approach is non-destructive, rapid, can provide reliable results, and requires no sample preparation, making it of ample importance to the field of forensic science. © The Author(s) 2016.

Radiation protection at the RA Reactor in 1993, RA research reactor, Part

International Nuclear Information System (INIS)

Ninkovic, M.; Pavlovic, R.; Mandic, M.; Sipka, V.; Grsic, Z.

1993-01-01

Radiation protection tasks which enable safe operation of the RA reactor, and are defined according the the legal regulations and IAEA safety recommendations are sorted into four categories in this report: (1) Control of the working environment, dosimetry and radiation protection at the RA reactor; (2) decontamination, collecting and treatment of fluid effluents and solid wastes; (3) Radioactivity control in the vicinity of the reactor and (4)meteorology measurements; (3). Each of the category is described as a separate annex of this report [sr

Reflections on the therapeutic use of 223RaCl2 for bone metastases resulting from prostate cancer resistant to castration

International Nuclear Information System (INIS)

Astudillo V, A. J.; Paredes G, L.

2015-10-01

In January 2014 the Comision Federal para la Proteccion contra Riesgos Sanitarios of the Ministry of Health in Mexico, authorize the use of 223 RaCl 2 as the first radiopharmaceutical emitter α for therapeutic purposes in cases of bone metastases resulting from prostate cancer resistant to castration. The paper analyzes the main variables that affect the metrological traceability using activity meters to evaluate the gamma activity of 223 RaCl 2 in hospitals, because it has a chain of complex decay with alpha, beta and gamma emitters, so was important to verify if a gamma activity measurement for a multiple emitter is reliable to determine the total alpha absorbed dose to bone in a patient. (Author)

Attenuated total internal reflection infrared microspectroscopic imaging using a large-radius germanium internal reflection element and a linear array detector.

Science.gov (United States)

Patterson, Brian M; Havrilla, George J

2006-11-01

The number of techniques and instruments available for Fourier transform infrared (FT-IR) microspectroscopic imaging has grown significantly over the past few years. Attenuated total internal reflectance (ATR) FT-IR microspectroscopy reduces sample preparation time and has simplified the analysis of many difficult samples. FT-IR imaging has become a powerful analytical tool using either a focal plane array or a linear array detector, especially when coupled with a chemometric analysis package. The field of view of the ATR-IR microspectroscopic imaging area can be greatly increased from 300 x 300 microm to 2500 x 2500 microm using a larger internal reflection element of 12.5 mm radius instead of the typical 1.5 mm radius. This gives an area increase of 70x before aberrant effects become too great. Parameters evaluated include the change in penetration depth as a function of beam displacement, measurements of the active area, magnification factor, and change in spatial resolution over the imaging area. Drawbacks such as large file size will also be discussed. This technique has been successfully applied to the FT-IR imaging of polydimethylsiloxane foam cross-sections, latent human fingerprints, and a model inorganic mixture, which demonstrates the usefulness of the method for pharmaceuticals.

Alkoholio ir tabako pasiūlos ir paklausos teisinio reguliavimo raida Lietuvos Respublikoje: problemos ir sprendimai

OpenAIRE

Mockevičius, Arminas

2014-01-01

Viešosios teisės magistro studijų programos studento Armino Mockevičiaus buvo parašytas magistro baigiamasis darbas „Alkoholio ir tabako pasiūlos ir paklausos teisinio reguliavimo raida Lietuvos Respublikoje: problemos ir sprendimai“. Šis darbas parašytas Vilniuje, 2014 metais, Mykolo Romerio universiteto Teisės fakulteto Konstitucinės ir administracinės teisės institute, vadovaujant dr. Gintautui Vilkeliui, apimtis 98 p. Darbo tikslas yra atskleisti alkoholio ir tabako pasiūlos ir paklau...

RA Research reactor, Part 1, Operation and maintenance of the RA nuclear reactor for 1986; Istrazivacki nuklearni reaktor RA, deo 1, pogon i odrzavanje nukleanog reaktora RA u 1986. godini

Energy Technology Data Exchange (ETDEWEB)

Sotic, O; Martinc, R; Cupac, S; Sulem, B; Badrljica, R; Majstorovic, D; Sanovic, V [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1986-12-01

In order to enable future reliable operation of the RA reactor, according to new licensing regulations, three major tasks started in 1984 were fulfilled: building of the new emergency system, reconstruction of the existing ventilation system, and reconstruction of the power supply system. Simultaneously in 1985/1986 renewal of the instrumentation and reconstruction of the system for handling and storage of the spent fuel in the reactor building have started. Design projects for these tasks are almost finished and the reconstruction of both systems is expected to be finished until 1988 and mid 1989 respectively. RA reactor Safety report was finished according to the recommendations of the IAEA. Investments in 1986 were used for 8000 kg of heavy water, maintenance of reactor systems and supply of new components, reconstruction of reactor systems. This report includes 8 annexes concerning reactor operation, activities of services and financial issues. [Serbo-Croat] Sa ciljem da se obezbedi pouzdan rad reaktora RA a u skladu sa zakonskim propisima, zavrsena su tri velika zahvata zapoceta 1984: izgradnja novog sistema za udesno hladjenje, rekonstrukcija postojeceg sistema za ventilaciju, i modernizacija reaktorske instrumentacije. Istovremeno tokom 1985/1986. zapoceta je modernizacija instrumentacije i rekonstrukcija sistema za rukovanje i skladistenje iskoriscenog goriva u zgradi reaktora. Projekti za navedene radove su vec zavrseni ili su u zavrsnoj fazi, a ocekuje se da ce rekonstrukcija oba sistema biti zavrsena do kraja 1988. odnosno sredine 1989. godine. Izrada izvestaja o sigurnosti reaktora RA, prema preporukama MAAE zavrsena je 1986. Investiciona ulaganja na reaktoru Ra u 1986. iskoriscena su za: nabavku 8000 kg teske vode, za investiciono odrzavanje reaktorskih sistema i nabavku opreme, za rekonstrukciju reaktorskih sistema. Ovaj izvestaj sadrzi 8 priloga koji opisuju rad reaktora, rad strucnih sluzbi i finansiranje.

Research nuclear reactor RA - Annual Report 1975. Operation and maintenance

International Nuclear Information System (INIS)

Martinc, R.

1976-01-01

The plan for 1975 was successfully fulfilled. This is reflected in research related to improvement of operating properties of the RA reactor, mostly due to the effort of the RA staff employed in operation and maintenance of the reactor. Fuel saving achieved by this activity amounted to about 38% (80% enriched fuel). Preliminary work is done, concerned with new reactor core with highly enriched fuel. This is a significant saving as well. New fuel elements have arrived at the end of this year. It is going to enable increase of neutron flux by 50% without changing the nominal operating power. The possibility of further improvement of the reactor are analyzed, to enable material testing and production of radioactive sources. Mid term plan for reactor operation was made according to this analysis. It is planned to further increase the neutron flux in isolated smaller zones, and building new experimental loops with cooling and fast neutron converters. Much was done to increase the safety level of reactor operation and preparing the safety report [sr

IR-based spot weld NDT in automotive applications

Science.gov (United States)

Chen, Jian; Feng, Zhili

2015-05-01

Today's auto industry primarily relies on destructive teardown evaluation to ensure the quality of the resistance spot welds (RSWs) due to their criticality in crash resistance and performance of vehicles. The destructive teardown evaluation is labor intensive and costly. The very nature of the destructive test means only a few selected welds will be sampled for quality. Most of the welds in a car are never checked. There are significant costs and risks associated with reworking and scrapping the defective welded parts made between the teardown tests. IR thermography as a non-destructive testing (NDT) tool has its distinct advantage — its non-intrusive and non-contact nature. This makes the IR based NDT especially attractive for the highly automated assembly lines. IR for weld quality inspection has been explored in the past, mostly limited to the offline post-processing manner in a laboratory environment. No online real-time RSW inspection using IR thermography has been reported. Typically for postprocessing inspection, a short-pulse heating via xenon flash lamp light (in a few milliseconds) is applied to the surface of a spot weld. However, applications in the auto industry have been unsuccessful, largely due to a critical drawback that cannot be implemented in the high-volume production line - the prerequisite of painting the weld surface to eliminate surface reflection and other environmental interference. This is due to the low signal-to-noise ratio resulting from the low/unknown surface emissivity and the very small temperature changes (typically on the order of 0.1°C) induced by the flash lamp method. An integrated approach consisting of innovations in both data analysis algorithms and hardware apparatus that effectively solved the key technical barriers for IR NDT. The system can be used for both real-time (during welding) and post-processing inspections (after welds have been made). First, we developed a special IR thermal image processing method that

Research nuclear reactor RA - Annual Report 1991; Istrazivacki nuklearni reaktor RA - Izvestaj za 1991. godinu

Energy Technology Data Exchange (ETDEWEB)

Sotic, O [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1992-01-01

Activities related to revitalisation of the RA reactor stared in 1986, were continued in 1991. A number of interventions on the reactor components were finished that are supposed to enable continuous and reliable operation. The last, and at the same time largest action, related to exchange of complete reactor instrumentation is underway, but it is behind the schedule in 1991 because the delivery of components from USSR is late. Production of this instruments is financed by the IAEA according to the contract signed in December 1988 with Russian Atomenergoexport. According to this contract, it has been planned that the RA reactor instrumentation should be delivered to the Vinca Institute by the end of 1990. Only 56% of the instrumentation was delivered until September 1991. Since then any delivery of components to Yugoslavia was stopped because of the temporary embargo imposed by the IAEA. In 1991 most of the existing RA reactor instrumentation was dismantled, only the part needed for basic measurements when reactor is not operated, was maintained. Construction of some support elements is almost finished by the local staff. The Institute has undertaken this activity in order to speed up the ending of the project. If all the planned instrumentation would not arrive until the end of March 1992, it would not be possible to start the RA reactor testing operation in the first part of 1993, as previously planned. In 1991, 53 staff members took part in the activities during 1991, which is considered sufficient for maintenance and repair conditions. Research reactor RA Annual report for year 1991 is divided into two main parts to cover: (1) operation and maintenance and (2) activities related to radiation protection. [Serbo-Croat] U 1991. godini nastavljeni su poslovi na revitalizaciji reaktora RA, zapocetoj 1986. godine. Okoncan je niz zahvata na opremi postrojenja kojima ce se u narednom periodu omoguciti kontinualan i pouzdan rad ovog reaktora. Poslednji, i ujedno najveci

The influence of the reflective environment on the absorption of a human male exposed to representative base station antennas from 300 MHz to 5 GHz.

Science.gov (United States)

Vermeeren, G; Gosselin, M C; Kühn, S; Kellerman, V; Hadjem, A; Gati, A; Joseph, W; Wiart, J; Meyer, F; Kuster, N; Martens, L

2010-09-21

The environment is an important parameter when evaluating the exposure to radio-frequency electromagnetic fields. This study investigates numerically the variation on the whole-body and peak spatially averaged-specific absorption rate (SAR) in the heterogeneous virtual family male placed in front of a base station antenna in a reflective environment. The SAR values in a reflective environment are also compared to the values obtained when no environment is present (free space). The virtual family male has been placed at four distances (30 cm, 1 m, 3 m and 10 m) in front of six base station antennas (operating at 300 MHz, 450 MHz, 900 MHz, 2.1 GHz, 3.5 GHz and 5.0 GHz, respectively) and in three reflective environments (a perfectly conducting wall, a perfectly conducting ground and a perfectly conducting ground + wall). A total of 72 configurations are examined. The absorption in the heterogeneous body model is determined using the 3D electromagnetic (EM) finite-difference time-domain (FDTD) solver Semcad-X. For the larger simulations, requirements in terms of computer resources are reduced by using a generalized Huygens' box approach. It has been observed that the ratio of the SAR in the virtual family male in a reflective environment and the SAR in the virtual family male in the free-space environment ranged from -8.7 dB up to 8.0 dB. A worst-case reflective environment could not be determined. ICNIRP reference levels not always showed to be compliant with the basic restrictions.

The influence of the reflective environment on the absorption of a human male exposed to representative base station antennas from 300 MHz to 5 GHz

International Nuclear Information System (INIS)

Vermeeren, G; Joseph, W; Martens, L; Gosselin, M C; Kuehn, S; Kuster, N; Kellerman, V; Meyer, F; Hadjem, A; Gati, A; Wiart, J

2010-01-01

The environment is an important parameter when evaluating the exposure to radio-frequency electromagnetic fields. This study investigates numerically the variation on the whole-body and peak spatially averaged-specific absorption rate (SAR) in the heterogeneous virtual family male placed in front of a base station antenna in a reflective environment. The SAR values in a reflective environment are also compared to the values obtained when no environment is present (free space). The virtual family male has been placed at four distances (30 cm, 1 m, 3 m and 10 m) in front of six base station antennas (operating at 300 MHz, 450 MHz, 900 MHz, 2.1 GHz, 3.5 GHz and 5.0 GHz, respectively) and in three reflective environments (a perfectly conducting wall, a perfectly conducting ground and a perfectly conducting ground + wall). A total of 72 configurations are examined. The absorption in the heterogeneous body model is determined using the 3D electromagnetic (EM) finite-difference time-domain (FDTD) solver Semcad-X. For the larger simulations, requirements in terms of computer resources are reduced by using a generalized Huygens' box approach. It has been observed that the ratio of the SAR in the virtual family male in a reflective environment and the SAR in the virtual family male in the free-space environment ranged from -8.7 dB up to 8.0 dB. A worst-case reflective environment could not be determined. ICNIRP reference levels not always showed to be compliant with the basic restrictions.

The influence of the reflective environment on the absorption of a human male exposed to representative base station antennas from 300 MHz to 5 GHz

Energy Technology Data Exchange (ETDEWEB)

Vermeeren, G; Joseph, W; Martens, L [Ghent University-INTEC/IBBT, Gaston Crommenlaan 8 box 201, B-9050 Ghent (Belgium); Gosselin, M C; Kuehn, S; Kuster, N [IT' IS Foundation, Zurich (Switzerland); Kellerman, V; Meyer, F [EMSS, Stellenbosch (South Africa); Hadjem, A; Gati, A; Wiart, J, E-mail: Gunter.Vermeeren@intec.UGent.b [Orange Labs, Paris (France)

2010-09-21

The environment is an important parameter when evaluating the exposure to radio-frequency electromagnetic fields. This study investigates numerically the variation on the whole-body and peak spatially averaged-specific absorption rate (SAR) in the heterogeneous virtual family male placed in front of a base station antenna in a reflective environment. The SAR values in a reflective environment are also compared to the values obtained when no environment is present (free space). The virtual family male has been placed at four distances (30 cm, 1 m, 3 m and 10 m) in front of six base station antennas (operating at 300 MHz, 450 MHz, 900 MHz, 2.1 GHz, 3.5 GHz and 5.0 GHz, respectively) and in three reflective environments (a perfectly conducting wall, a perfectly conducting ground and a perfectly conducting ground + wall). A total of 72 configurations are examined. The absorption in the heterogeneous body model is determined using the 3D electromagnetic (EM) finite-difference time-domain (FDTD) solver Semcad-X. For the larger simulations, requirements in terms of computer resources are reduced by using a generalized Huygens' box approach. It has been observed that the ratio of the SAR in the virtual family male in a reflective environment and the SAR in the virtual family male in the free-space environment ranged from -8.7 dB up to 8.0 dB. A worst-case reflective environment could not be determined. ICNIRP reference levels not always showed to be compliant with the basic restrictions.

Development of a liquid scintillation method for in vitro determination of 226Ra and 228 Ra in bioassay samples

International Nuclear Information System (INIS)

Fernandes, Paulo Cesar P.; Sousa, Wanderson O.; Juliao, Ligia M.Q.C.; Dantas, Bernardo M.

2011-01-01

Radium isotopes are dispersed in the environment according to their physicochemical characteristics. The intake of 226 Ra and 228 Ra in humans can occur by inhalation and ingestion and the risk of internal exposure are related to their long half-lives, characteristics of the emission and biokinetics of the isotopes in the human body. The goal of this work is to develop a methodology for the analysis of 226 Ra and 228 Ra in excreta samples (urine and feces), using liquid scintillation technique. Excreta samples were provided by non-exposed humans for the purpose of standardizing the methodology and the establishment of a background level of radium excretion. Radium isotopes were concentrated and separated from the constituents of the sample by co-precipitation with barium sulphate. The precipitate of Ba(Ra)SO 4 was filtrated and weighted for the determination of the chemical yield. The filter containing the precipitate was transferred to a scintillation vial. In the scintillation vial, 8 mL of water, 8 mL of Instagel XF and 4 mL of UltimaGold were added, forming a gel suspension, after stirring the solution. The 226 Ra and 228 Ra activities were determined 21 days after the precipitation of samples. The samples were counted in a liquid scintillation spectrometer. The technique presented adequate sensitivity and reproducibility for the analysis of urine and feces. The activities of 226 Ra and 228 Ra in excreta samples provide useful information for the identification of the main route of intake and for the assessment of the internal exposure of occupationally exposed workers and inhabitants of high background areas. (author)

An FT-Raman, FT-IR, and Quantum Chemical Investigation of Stanozolol and Oxandrolone

Directory of Open Access Journals (Sweden)

Tibebe Lemma

2017-12-01

Full Text Available We have studied the Fourier Transform Infrared (FT-IR and the Fourier transform Raman (FT-Raman spectra of stanozolol and oxandrolone, and we have performed quantum chemical calculations based on the density functional theory (DFT with a B3LYP/6-31G (d, p level of theory. The FT-IR and FT-Raman spectra were collected in a solid phase. The consistency between the calculated and experimental FT-IR and FT-Raman data indicates that the B3LYP/6-31G (d, p can generate reliable geometry and related properties of the title compounds. Selected experimental bands were assigned and characterized on the basis of the scaled theoretical wavenumbers by their total energy distribution. The good agreement between the experimental and theoretical spectra allowed positive assignment of the observed vibrational absorption bands. Finally, the calculation results were applied to simulate the Raman and IR spectra of the title compounds, which show agreement with the observed spectra.

226Ra measurement by thermal ionisation mass spectrometry: Use of 226Ra and 14C for groundwater dating

International Nuclear Information System (INIS)

Dever, L.

1997-01-01

Recent developments in thermal ionisation mass spectrometry (TIMS) and in chemical separation Ra and Ba allow to analyse 226 Ra on smaller water samples ( 3 litres). The sampling has been realised on the Chalk aquifer of the Paris basin. The water samples have been collected in the unsaturated zone using in situ filtering devices and in the unconfined and confined parts of the aquifer in the boreholes used for public water supply. 226 Ra contents vary from 0.064±0.02 dpm/kg (n=6) in the unsaturated zone to 0.119±0.069 dpm/kg (n=7) in the unconfined aquifer and 0.319±0.057 dpm/kg (n=9) in the confined aquifer. For all the samples the 226 Ra/ 238 U activity ratios are much lower than the secular equilibrium. This points out that the two isotopes have different input function in the water during the mineralisation of the solution. The good correlation (r 2 =0.9) between the 226 Ra and Sr indicates that dissolution of Chalk is the dominant mechanism of mineralisation in 226 Ra of the solution. In the Chalk the mineralisation of the water occurs in the first metres of the unsaturated zone, during the water percolation the water rock interaction takes place through dissolution and precipitation of calcite in a non steady state. According to his distribution coefficient Sr is then a better tracer of dissolution/precipitation process than Ba. Using a geochemical model based on 226 Ra/Sr and Sr/Ca ratios an 'age' of the water could be determined. With 226 Ra half life of 1620 years we obtain 'ages' varying from 150 years to 1950 years in the unconfined aquifer. For the confined part of the aquifer where the redox condition is different it is necessary to use a geochemical model based on the U concentration in the water, the 226 Ra gives in such case ages varying from 1.8ka to 12.8ka. The radiocarbon ages obtained through usual chemical and/or isotopic models are quite similar and an isochrome between 226 Ra and 14 C ages can be calculated between 0 and 8ka

Camouflage in thermal IR: spectral design

Science.gov (United States)

Pohl, Anna; Fagerström, Jan; Kariis, Hans; Lindell, Roland; Hallberg, Tomas; Högström, Herman

2016-10-01

In this work a spectral designed coating from SPECTROGON is evaluated. Spectral design in this case means that the coating has a reflectivity equal to one at 3-5 and 8-12 microns were sensors operate and a much lower reflectivity in the other wave length regions. Three boxes are evaluated: one metallic, one black-body and one with a spectral designed surface, all with a 15 W radiator inside the box. It is shown that the box with the spectral designed surface can combine the two good characteristics of the other boxes: low signature from the metallic box and reasonable inside temperature from the black-body box. The measurements were verified with calculations using RadThermIR.

The decay scheme of 229Ra

International Nuclear Information System (INIS)

Yang, W.F.; Yuan, S.G.; Fang, K.M.; Shen, S.F.; Mou, W.T.; Zhang, X.Q.; Li, Z.Q.

1997-01-01

By bombarding the natural thorium targets with 14 MeV neutrons, 229 Ra was produced through the reaction 232 Th(n,α) 229 Ra. The radium activities were separated from the irradiated targets by coprecipitation with the BaCl 2 . A total of 18 new weak γ rays with energies of 14.5, 15.6, 18.8, 21.8, 22.5, 44.0, 47.5, 55.0, 63.0, 69.6, 93.6, 94.1, 98.5, 102.2, 104.5, 106.1, 161.1, and 171.5 keV which could be assigned to the decay of 229 Ra were observed in the isolated radium fractions employing high resolution HPGe detectors and γ(X)-γ coincidence methods. A decay scheme of 229 Ra based on these observations is proposed. (orig.). With 2 figs

Far IR spectra of Th(IV) halide complexes of some heterocyclic bases

International Nuclear Information System (INIS)

Srivastava, A.K.; Agarwal, R.K.; Srivastava, M.; Kapoor, V.; Srivastava, T.N.

1981-01-01

The synthesis and IR spectra of Th(IV) perchlorato, nitrato and thiocyanato complexes of some heterocyclic bases have been reported. Halogens are common ligands in coordination chemistry forming coordinate bonds with metals readily. Metal halogen (M-X) stretching bands show a strong absorption in the far-IR region. Very little information is available on Th-X stretching frequencies. In the present communication, adducts of Th(IV) halide with certain nitrogen heterocyclic bases such as pyridine, α-picoline, 2-amino pyridine, 2:4-lutidine, 2:6-lutidine, quinoline, 2,2'-bipyridine and 1,10-phenanthroline were synthesised and characterised. Experimental details are given. Results are presented and discussed. (author)

Generation of various carbon nanostructures in water using IR/UV laser ablation

International Nuclear Information System (INIS)

Mortazavi, Seyedeh Zahra; Parvin, Parviz; Reyhani, Ali; Mirershadi, Soghra; Sadighi-Bonabi, Rasoul

2013-01-01

A wide variety of carbon nanostructures were generated by a Q-switched Nd : YAG laser (1064 nm) while mostly nanodiamonds were created by an ArF excimer laser (193 nm) in deionized water. They were characterized by transmission electron microscopy, Raman spectroscopy and x-ray photoelectron spectroscopy. It was found that the IR laser affected the morphology and structure of the nanostructures due to the higher inverse bremsstrahlung absorption rate within the plasma plume with respect to the UV laser. Moreover, laser-induced breakdown spectroscopy was carried out so that the plasma created by the IR laser was more energetic than that generated by the UV laser. (paper)

FT-IR spectrum of grape seed oil and quantum models of fatty acids triglycerides

Science.gov (United States)

Berezin, K. V.; Antonova, E. M.; Shagautdinova, I. T.; Chernavina, M. L.; Dvoretskiy, K. N.; Grechukhina, O. N.; Vasilyeva, L. M.; Rybakov, A. V.; Likhter, A. M.

2018-04-01

FT-IR spectra of grape seed oil and glycerol were registered in the 650-4000 cm-1 range. Molecular models of glycerol and some fatty acids that compose the oil under study - linoleic, oleic, palmitic and stearic acids - as well as their triglycerides were developed within B3LYP/6-31G(d) density functional model. A vibrating FT-IR spectrum of grape seed oil was modeled on the basis of calculated values of vibrating wave numbers and IR intensities of the fatty acids triglycerides and with regard to their percentage. Triglyceride spectral bands that were formed by glycerol linkage vibrations were revealed. It was identified that triglycerol linkage has a small impact on the structure of fatty acids and, consequently, on vibrating wave numbers. The conducted molecular modeling became a basis for theoretical interpretation on 10 experimentally observed absorption bands in FT-IR spectrum of grape seed oil.

RA Reactor

International Nuclear Information System (INIS)

1989-01-01

This chapter includes the following: General description of the RA reactor, organization of work, responsibilities of leadership and operators team, regulations concerning operation and behaviour in the reactor building, regulations for performing experiments, regulations and instructions for inserting samples into experimental channels [sr

226Ra and 228Ra in the mixing zones of the Pee Dee River-Winyah Bay, Yangtze River and Delaware Bay Estuaries

International Nuclear Information System (INIS)

Elsinger, R.J.; Moore, W.S.

1984-01-01

226 Ra and 228 Ra have non-conservative excess concentrations in the mixing zones of the Pee Dee River-Winyah Bay estuary, the Yangtze River estuary, and the Delaware Bay estuary. Laboratory experiments, using Pee Dee River sediment, indicate desorption of 226 Ra to increase with increasing salinities up to 20 per mille. In Winyah Bay desorption from river-borne sediments could contribute almost all of the increases for both isotopes. Desorption adds only a portion of the excess 228 Ra measured in the Yangtze River and adjacent Shelf waters and Delaware Bay. In the Yangtze River the mixing zone extends over a considerable portion of the Continental Shelf where 228 Ra is added to the water column by diffusion from bottom sediments, while 226 Ra concentrations decrease from dilution. Diffusion of 228 Ra from bottom sediments in Delaware Bay primarily occurs in the upper part of the bay ( 228 Ra of 0.33 dpm cm -2 year was determined for Delaware Bay. (author)

A experimental system for the checking of the absorption of E.C.A.G. graphite

International Nuclear Information System (INIS)

Raievski, V.; Vidal, R.

1958-01-01

A system is described for measuring the mean absorption cross section in thermal neutrons of graphite. This system consists of a graphite stack containing a Ra-Be source and a BF3 counter. A cavity in the stack receives the graphite to be studied or the graphite standard. By comparing the counting rates their absorption ratio can be deduced. The measurement is performed on graphite rods which have been machined before being placed in the pile. It provides the possibility of detecting over a batch of 1 ton of graphite, in a single measurement, a difference in absorption of 0.1 milli barn. (author) [fr

Optical absorption of hyperbolic metamaterial with stochastic surfaces

DEFF Research Database (Denmark)

Liu, Jingjing; Naik, Gururaj V.; Ishii, Satoshi

2014-01-01

We investigate the absorption properties of planar hyperbolic metamaterials (HMMs) consisting of metal-dielectric multilayers, which support propagating plane waves with anomalously large wavevectors and high photonic-density-of-states over a broad bandwidth. An interface formed by depositing...... indium-tin-oxide nanoparticles on an HMM surface scatters light into the high-k propagating modes of the metamaterial and reduces reflection. We compare the reflection and absorption from an HMM with the nanoparticle cover layer versus those of a metal film with the same thickness also covered...... with the nanoparticles. It is predicted that the super absorption properties of HMM show up when exceedingly large amounts of high-k modes are excited by strong plasmonic resonances. In the case that the coupling interface is formed by non-resonance scatterers, there is almost the same enhancement in the absorption...

Bulk damage and absorption in fused silica due to high-power laser applications

Science.gov (United States)

Nürnberg, F.; Kühn, B.; Langner, A.; Altwein, M.; Schötz, G.; Takke, R.; Thomas, S.; Vydra, J.

2015-11-01

Laser fusion projects are heading for IR optics with high broadband transmission, high shock and temperature resistance, long laser durability, and best purity. For this application, fused silica is an excellent choice. The energy density threshold on IR laser optics is mainly influenced by the purity and homogeneity of the fused silica. The absorption behavior regarding the hydroxyl content was studied for various synthetic fused silica grades. The main absorption influenced by OH vibrational excitation leads to different IR attenuations for OH-rich and low-OH fused silica. Industrial laser systems aim for the maximum energy extraction possible. Heraeus Quarzglas developed an Yb-doped fused silica fiber to support this growing market. But the performance of laser welding and cutting systems is fundamentally limited by beam quality and stability of focus. Since absorption in the optical components of optical systems has a detrimental effect on the laser focus shift, the beam energy loss and the resulting heating has to be minimized both in the bulk materials and at the coated surfaces. In collaboration with a laser research institute, an optical finisher and end users, photo thermal absorption measurements on coated samples of different fused silica grades were performed to investigate the influence of basic material properties on the absorption level. High purity, synthetic fused silica is as well the material of choice for optical components designed for DUV applications (wavelength range 160 nm - 260 nm). For higher light intensities, e.g. provided by Excimer lasers, UV photons may generate defect centers that effect the optical properties during usage, resulting in an aging of the optical components (UV radiation damage). Powerful Excimer lasers require optical materials that can withstand photon energy close to the band gap and the high intensity of the short pulse length. The UV transmission loss is restricted to the DUV wavelength range below 300 nm and

Operation and maintenance of the RA reactor, RA Research reactor. Annual report 1976; Pogon i odrzavanje reaktora RA, Izvestaj o radu u 1976. godini

Energy Technology Data Exchange (ETDEWEB)

Martinc, R [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1976-12-15

During 1976 the Ra reactor was operating for about 30% shorter period than usual. The reason were extraordinary repair activities within regular and investment maintenance as well as repair of failures caused by neglected maintenance during previous 6 years. Delay was caused by unavailability of fuel (2% enriched fuel elements are spent) and the new 80% enriched fuel demanded experimental and theoretical analyses before being introduced into the core. Safety analyses concerned with using 80% enriched fuel both experimental and theoretical were successfully fulfilled. The December 1976 successful experimental campaign can be marked as end of the 17 years period of using 2% enriched fuel and start of the new period of using highly enriched fuel. This is significant not only for the reactor itself but for the users, because it would result in increase of neutron flux by 50% with the increase of costs by only 4%. Demand was submitted for obtaining the final license for transition operating regime with highly enriched fuel which would save at least 2 200 000 dinars. This will enable reactor operation in 1977 and later on, without interruption by 'critical' and other experiments related to new highly enriched fuel. A high number of repair and other urgent activities were fulfilled in order to enable safe operation. Some of these activities were done never before and some were neglected during past 6 years. The most important tasks were: purchase of Al tubes made of special alloy, fabrication and mounting of the fuel channel; overall investigation of reactor vessel leakage; repair of the heavy water pump; exchange of two vertical channels. basic equipment for construction of emergency cooling system was purchased. Hot cells are equipped for independent utilisation. [Serbo-Croat] Reaktor RA je u 1976. godini radio za oko 30% krace vreme od uobicajenog. Razlog su bill izuzetno veliki obim remontnih i drugih radova u okviru tekuceg i investicionog odrzavanja, kao i krupnih

The influence of optical parameters on impurity determinations by IR spectroscopy

International Nuclear Information System (INIS)

Lombard, O.J.

1985-01-01

The important role of impurities in semiconductor materials is the subject of continuous research. The concentration of interstitial oxygen impurities in silicon are determined with the aid of infrared spectroscopy. The maximum absorption coefficient of the oxygen absorption peak, centered at 9,06 μm, is determined and the impurity concentration is then calculated using a calibration factor. This procedure was evaluated, paying particular attention to those optical parameters which may influence these impurity determinations. A thorough discussion of the theoretical and experimental aspects of infrared spectroscopy in general is followed by an overview of previous experimental work. This lead to some theoretical analysis regarding the influence of the index of refraction, the index of absorption and multiple reflections in the silicon wafer on impurity determinations. This lead to specific experimental investigations. The influence of the surface morphology of samples on impurity determinations was studied by determining the reflectance of silicon surfaces. It was established that the surface reflectance plays a role and that it must be taken into consideration for accurate impurity concentration determinations. The most accurate values for the absorption coefficient due to oxygen in silicon are calculated. This requires that the surface of the silicon wafers must be highly polished for the formula to be valid. Acceptable values for the absorption coefficient of damaged surfaces are obtained if the uncorrected formula is used. Experimental results may deviate as much as 32% from the real impurity concentration if the wrong formula is used to calculate the absorption coefficient of oxygen in silicon at 9,06 μm

Concentration of natural radionuclides (40K, 228Ra and 226Ra) in vegetables and fruits collected around Kudankulam, South India

International Nuclear Information System (INIS)

Mahiban Ross, E.; Feroz Khan, M.; Lenin Raj, Y.; Godwin Wesley, S.; Kumar, M.; Sundar Rajan, P.

2007-01-01

Baseline activity concentration of the natural radio nuclides 40 K, 228 Ra and 226 Ra in vegetables and fruits was determined around Kudankulam. In many of the samples, 228 Ra and 226 Ra was below minimum detection limit. 40 K was found to be more in leafy vegetables followed by pods, tubers and fleshy fruits. The highest accumulator among the matrices was the leafy vegetables with the geometric mean of 189.47 Bq.kg -1 fresh for vegetables and fruits with the geometric mean of 128.95 Bq.kg -1 fresh. 228 Ra activity in vegetables and fruits ranged from 0.074 to 1.153 and 0.074 to 0.131 Bq.kg -l fresh respectively. 226 Ra in vegetables and fruits ranged from BDL to 0.07 and BDL-.044 Bq.kg -l fresh respectively. 40 K in vegetables and fruits followed a log normal distribution. (author)

RA Research nuclear reactor, Part II - radiation protection at the RA nuclear reactor in 1984; Istrazivacki nuklearni reaktor RA - Deo II - zastita od zracenja kod nuklearnog reaktora RA u 1984. godini

Energy Technology Data Exchange (ETDEWEB)

Ninkovic, M; Ajdacic, N; Zaric, M; Vukovic, Z [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

1984-12-15

Radon protection tasks which enable safe operation of the RA reactor, and are defined according the the legal regulations and IAEA safety recommendations are sorted into four categories in this report: (1) Control of the working environment, dosimetry at the RA reactor; (2) Radioactivity control in the vicinity of the reactor and meteorology measurements; (3) Collecting and treatment of fluid effluents; and (4) radioactive wastes, decontamination and actions. Each category is described as a separate annex of this report.

Improving an Empirical Formula for the Absorption of Sound in the Sea

Science.gov (United States)

2008-05-01

Onderwater propagatie Advanced acoustic modelling Auteur (s) ir. C.A.M van Moll Programmanummer Projectnummer dr. M.A. Ainslie V512 032.11648 ing. J...versus calculated absorption .................................................................... 9 3 Inverse theory ...45 7.1 Statistical theory

Bioavailability of radionuclides 226Ra, 228Ra and 210Pb present in the brazilian phosphate fertilizers and phosphogypsum

International Nuclear Information System (INIS)

Russo, Ana Carolina

2013-01-01

Phosphogypsum, also called gypsum, by-product of the phosphate fertilizer industry, can be used as soil conditioner since it provides improvements in the soil-plant system. However, this by-product concentrates radionuclides of the U and Th series, present in the phosphate rock used as raw material, which can impact the environment. In order to study the bioavailability of radionuclides, samples of phosphogypsum and phosphate fertilizers (monoammonium phosphate and triple superphosphate) were analyzed. The concentration of 226 Ra, 228 Ra and 210 Pb were determined by gamma spectrometry. The samples were leached with a mild EDTA solution and the radionuclides present in the final solution were determined by total alpha and beta counting on a gas flow proportional counter. The percentage of extraction varied from 1.6% to 1.7% for 210 Pb, from 0.5% to 1.4% for 226 Ra and from 0.1% to 1.0% for the 228 Ra in phosphogypsum samples. The low percentage of extraction obtained for the radionuclides can be partly explained by the low solubility of phosphogypsum, which ranged from 7.7% to 16%. For the monoammonium phosphate samples the percentage of extraction were less than 26% for 226 Ra, less than 10% for '2 28 Ra and less than 10% for 210 Pb. In spite of the high solubility of 77% of monoammonium phosphate in the EDTA solution, low concentrations of radionuclides were observed in the leached solution. For the triple superphosphate samples, the percentage of extraction was 2.3% for 226 Ra, 1.2% for 228 Ra and 11.3% for 210 Pb. In spite of the high solubility of 66% of triple superphosphate in the EDTA solution, low concentrations of radionuclides were observed in the leached solution. (author)

IR technology for enhanced force protection by AIM

Science.gov (United States)

Breiter, R.; Ihle, T.; Rode, W.; Wendler, J.; Rühlich, I.; Haiml, M.; Ziegler, J.

2008-04-01

In all recent missions our forces are faced with various types of asymmetric threads like snipers, IEDs, RPGs or MANPADS. 2 nd and 3 rd Gen IR technology is a backbone of modern force protection by providing situational awareness and accurate target engagement at day/night. 3 rd Gen sensors are developed for thread warning capabilities by use of spectral or spatial information. The progress on a dual-color IR module is discussed in a separate paper [1]. A 1024x256 SWIR array with flexure bearing compressor and pulse tube cold finger provides > 50,000h lifetime for space or airborne hyperspectral imaging in pushbroom geometry with 256 spectral channels for improved change detection and remote sensing of IEDs or chemical agents. Similar concepts are pursued in the LWIR with either spectroscopic imaging or a system of LWIR FPA combined with a cooled tunable Laser to do spectroscopy with stimulated absorption of specific wavelengths. AIM introduced the RangIR sight to match the requirements of sniper teams, AGLs and weapon stations, extending the outstanding optronic performance of the fielded HuntIR with position data of a target by a laser range finder (LRF), a 3 axis digital magnetic compass (DMC) and a ballistic computer for accurate engagement of remote targets. A version with flexure bearing cooler with >30,000h life time is being developed for continuous operation in e.g. gunfire detection systems. This paper gives an overview of AIM's technologies for enhanced force protection.

Safety analysis of RA Reactor operation I-III; Analiza sigurnosti rada Reaktora RA I - III, IZ-213-0322-1963

Energy Technology Data Exchange (ETDEWEB)

Raisic, N [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1963-02-15

This safety analysis report covers the following three parts: Technical and operational characteristics of the RA reactor; Accidents analysis; and Environmental effects of the maximum possible accident. [Serbo-Croat] Ovaj izvestaj o analizi sigurnosti rada reaktora RA sastoji se od tri dela: Tehnicke i pogonske karakteristike reaktora RA; Analiza akcidenta; i Posledice maksimalno moguceg akcidenta na okolinu reaktora.

Ultraviolet reflectance spectroscopy measurements of carbonaceous meteorites and planetary analog materials

Science.gov (United States)

Hibbitts, Charles A.; Stockstill-Cahill, Karen; Takir, Driss

2017-10-01

The compositions of airless solar system objects tell us about the origin and evolutionary processes that are responsible for the current state of our solar system and that shape our environment. Spectral reflectance measurements in the ultraviolet are being used more frequently for providing compositional information of airless solid surfaces. Most minerals absorb in the UV making studying surface composition both informative but also challenging [e.g. 1]. The UV region is sensitive to atomic and molecular electronic absorptions such as the ligand-metal charge transfer band that is present in oxides and silicates and the conduction band at vacuum UV wavelengths. At the JHU-APL, bidirectional UV reflectance measurements are obtained under vacuum using a McPherson monochrometer with a PMT detector to achieve measurements over the range from ~ 140 nm to ~ 570 nm. Sample temperature can also be controlled from ~ 100K to ~ 600K, which enables the exploring the interaction of water ice and other volatiles with refractory samples. We have measured the UV spectra of many carbonaceous chondrites, including Mokoia, Vigarano, Warrenton, Orgueil, SaU290, and Essebi. In addition to being dark, some also possess on OMCT band. We have also obtained IR measurement of these meteorites to explore possible correlations between their UV and IR spectral signatures. In addition, we have also measured the UV spectra of low water content lunar analog glasses and have found a correlation between the spectral nature of the OMCT band and the abundance of iron [3]. Also, the spectral signature of mineralic and adsorbed water in the UV has been investigated. While water-ice has a known strong absorption feature near 180 nm (e.g. 4], adsorbed molecular and disassociatively adsorbed OH appear to not be optically active in this spectral region [5]. References: [1] Wagner et al. (1987) Icarus, 69, 14-28.1987; [2] Cloutis et al. (2008) Icarus, 197, 321-347; [3] Greenspon et al. (2012), 43rd LPSC

Patterns of FOS protein induction in singing female starlings

Science.gov (United States)

Riters, Lauren V.

2013-01-01

Females of many songbird species produce song, but information about the neural correlates of singing behavior is limited in this sex. Although well studied in males, activity in premotor song control regions and social behavior regions has not been examined in females during song production. Here, we examined the immediate early gene protein product FOS in both song control and social behavior brain regions after female starlings defending nest boxes responded to an unfamiliar female in a naturalistic setting. We found that females that sang in response to the intruder had much higher numbers of fos-immunoreactive neurons (fos-ir) in the vocal control regions HVC, the robust nucleus of the arcopallium (RA), and the dorsomedial part of the nucleus intercollicularis (DM of the ICo). In HVC, fos-ir correlated positively with song length. In RA, DM and Area X, fos-ir correlated positively with number of songs produced. In social behavior regions, singers showed higher fos-ir in the nucleus taeniae of the amygdala, the dorsal part of the bed nucleus of the stria terminalis, and the ventromedial hypothalamus than non-singers. Overall, patterns of fos-ir in song control regions in females were similar to those reported for males, but differences in fos-ir were identified in social behavior regions. These differences may reflect a distinct role for brain regions involved in social behavior in female song, or they may reflect differences in the social function of female and male song. PMID:23022365

The mid-IR Absorption Cross Sections of α- and β-NAT (HNO3 · 3H2O) in the range 170 to 185 K and of metastable NAD (HNO3 · 2H2O) in the range 172 to 182 K

Science.gov (United States)

Iannarelli, R.; Rossi, M. J.

2015-11-01

Growth and Fourier transform infrared (FTIR) absorption in transmission of the title nitric acid hydrates have been performed in a stirred flow reactor (SFR) under tight control of the H2O and HNO3 deposition conditions affording a closed mass balance of the binary mixture. The gas and condensed phases have been simultaneously monitored using residual gas mass spectrometry and FTIR absorption spectroscopy, respectively. Barrierless nucleation of the metastable phases of both α-NAT (nitric acid trihydrate) and NAD (nitric acid dihydrate) has been observed when HNO3 was admitted to the SFR in the presence of a macroscopic thin film of pure H2O ice of typically 1 µm thickness. The stable β-NAT phase was spontaneously formed from the precursor α-NAT phase through irreversible thermal rearrangement beginning at 185 K. This facile growth scheme of nitric acid hydrates requires the presence of H2O ice at thicknesses in excess of approximately hundred nanometers. Absolute absorption cross sections in the mid-IR spectral range (700-4000 cm-1) of all three title compounds have been obtained after spectral subtraction of excess pure ice at temperatures characteristic of the upper troposphere/lower stratosphere. Prominent IR absorption frequencies correspond to the antisymmetric nitrate stretch vibration (ν3(NO3-)) in the range 1300 to 1420 cm-1 and the bands of hydrated protons in the range 1670 to 1850 cm-1 in addition to the antisymmetric O-H stretch vibration of bound H2O in the range 3380 to 3430 cm-1 for NAT.

CdTe reflection anisotropy line shape fitting

International Nuclear Information System (INIS)

Molina-Contreras, J.R.

2010-01-01

In this paper, an empirical novel plane-wave time dependent ensemble is introduced to fit the RA, the reflectance (R) and the imaginary part of the dielectric function oscillation measured around the E 1 and E 1 + Δ 1 transition region in II-VI semiconductors. By applying the new plane-wave time dependent ensemble to the measured spectrum for a (0 0 1) oriented CdTe undoped commercial wafer, crystallized in a zinc-blende structure, a very good agreement was found between the measured spectrum and the fitting. In addition to this, the reliability of the plane-wave time dependent ensemble was probed, by comparing the results with the calculated fitting in terms of a Fourier series and in terms of a six-order polynomial fit. Our analysis suggests, that the experimental oscillation in the line shape of the RA cannot be fitted with a Fourier series using harmonics multiples of the number which dominates the measured RA spectra in the argument of the plane-wave ensemble.

Rheumatoid Arthritis (RA) associated interstitial lung disease (ILD).

LENUS (Irish Health Repository)

O'Dwyer, David N

2013-10-01

Rheumatoid Arthritis (RA) is the most common Connective Tissue Disease (CTD) and represents an increasing burden on global health resources. Interstitial lung disease (ILD) has been recognised as a complication of RA but its potential for mortality and morbidity has arguably been under appreciated for decades. New studies have underscored a significant lifetime risk of ILD development in RA. Contemporary work has identified an increased risk of mortality associated with the Usual Interstitial Pneumonia (UIP) pattern which shares similarity with the most devastating of the interstitial pulmonary diseases, namely Idiopathic Pulmonary Fibrosis (IPF). In this paper, we discuss recent studies highlighting the associated increase in mortality in RA-UIP. We explore associations between radiological and histopathological features of RA-ILD and the prognostic implications of same. We emphasise the need for translational research in this area given the growing burden of RA-ILD. We highlight the importance of the respiratory physician as a key stakeholder in the multidisciplinary management of this disorder. RA-ILD focused research offers the opportunity to identify early asymptomatic disease and define the natural history of this extra articular manifestation. This may provide a unique opportunity to define key regulatory fibrotic events driving progressive disease. We also discuss some of the more challenging and novel aspects of therapy for RA-ILD.

Inventory of 226Ra, 228Ra and 210Pb in marine sediments cores of Southwest Atlantic Ocean

International Nuclear Information System (INIS)

Costa, Alice M.R.; Oliveira, Joselene de; Figueira, Rubens C.L.; Mahiques, Michel M.; Sousa, Silvia H.M.

2015-01-01

210 Pb (22.3 y) is a radioactive isotope successfully applied as tracer of sediment dating of the last 100-150 years. The application of 226 Ra and 228 Ra as paleoceanographic tracers (half-lives of 1,600 y and 5.7 y, respectively) also gives some information of ocean's role in past climate change. In this work, it was analyzed 2 sediment cores collect at Southwest Atlantic Ocean. The sediments samples were freeze-dried and acid digested in microwave. It was carried out a radiochemical separation of 226 Ra, 228 Ra and 210 Pb and performed a gross alpha and gross beta measurement of both precipitates Ba(Ra)SO 4 and PbCrO 4 in a low background gas-flow proportional counter. Activity concentrations of 226 Ra ranged from 45 Bq kg -1 to 70 Bq kg -1 in NAP-62 and from 57 Bq kg -1 to 82 Bq kg -1 in NAP-63 samples. The concentration of 228 Ra varied between 37 Bq kg -1 and 150 Bq kg -1 in NAP-62 and between 23 Bq kg -1 and 111 Bq kg -1 in NAP-63 samples. The concentration of total 210 Pb ranged from 126 Bq kg -1 to 256 Bq kg -1 in NAP-62 and from 63 Bq kg -1 to 945 Bq kg -1 in NAP-63 samples. Results of 210 Pb uns varied from 68 Bq kg -1 to 192 Bq kg -1 for NAP-62, while varied from <4.9 Bq kg -1 to 870 Bq kg -1 in NAP-63 profile. Increased values of 210 Pb uns were found on the top of both NAP-62 and NAP- 63 sediment profile. (author)

Reverse saturable absorption (RSA) in fluorinated iridium derivatives

Science.gov (United States)

Ferry, Michael J.; O'Donnell, Ryan M.; Bambha, Neal; Ensley, Trenton R.; Shensky, William M.; Shi, Jianmin

2017-08-01

The photophysical properties of cyclometallated iridium compounds are beneficial for nonlinear optical (NLO) applications, such as the design of reverse saturable absorption (RSA) materials. We report on the NLO characterization of a family of compounds of the form [Ir(pbt)2(LX)], where pbt is 2-phenylbenzothiazole and LX is a beta-diketonate ligand. In particular, we investigate the effects of trifluoromethylation on compound solubility and photophysics compared to the parent acetylacetonate (acac) version. The NLO properties, such as the singlet and triplet excited-state cross sections, of these compounds were measured using the Z-scan technique. The excited-state lifetimes were determined from visible transient absorption spectroscopy.

Low reflectance radio frequency load

Science.gov (United States)

Ives, R. Lawrence; Mizuhara, Yosuke M

2014-04-01

A load for traveling microwave energy has an absorptive volume defined by cylindrical body enclosed by a first end cap and a second end cap. The first end cap has an aperture for the passage of an input waveguide with a rotating part that is coupled to a reflective mirror. The inner surfaces of the absorptive volume consist of a resistive material or are coated with a coating which absorbs a fraction of incident RF energy, and the remainder of the RF energy reflects. The angle of the reflector and end caps is selected such that reflected RF energy dissipates an increasing percentage of the remaining RF energy at each reflection, and the reflected RF energy which returns to the rotating mirror is directed to the back surface of the rotating reflector, and is not coupled to the input waveguide. Additionally, the reflector may have a surface which generates a more uniform power distribution function axially and laterally, to increase the power handling capability of the RF load. The input waveguide may be corrugated for HE11 mode input energy.

Two-Magnon Raman Scattering and Pseudospin-Lattice Interactions in Sr_{2}IrO_{4} and Sr_{3}Ir_{2}O_{7}.

Science.gov (United States)

Gretarsson, H; Sung, N H; Höppner, M; Kim, B J; Keimer, B; Le Tacon, M

2016-04-01

We have used Raman scattering to investigate the magnetic excitations and lattice dynamics in the prototypical spin-orbit Mott insulators Sr_{2}IrO_{4} and Sr_{3}Ir_{2}O_{7}. Both compounds exhibit pronounced two-magnon Raman scattering features with different energies, line shapes, and temperature dependencies, which in part reflect the different influence of long-range frustrating exchange interactions. Additionally, we find strong Fano asymmetries in the line shapes of low-energy phonon modes in both compounds, which disappear upon cooling below the antiferromagnetic ordering temperatures. These unusual phonon anomalies indicate that the spin-orbit coupling in Mott-insulating iridates is not sufficiently strong to quench the orbital dynamics in the paramagnetic state.

RA Research nuclear reactor, Part II: radiation protection at the RA reactor in 1987

International Nuclear Information System (INIS)

Ninkovic, M.; Ajdacic, N.; Zaric, M.; Vukovic, Z.

1987-01-01

Radiation protection tasks which enable safe operation of the RA reactor, and are defined according the the legal regulations and IAEA safety recommendations are sorted into four categories in this report: (1) Control of the working environment, dosimetry at the RA reactor and radiation protection; (2) Radioactivity control in the vicinity of the reactor and meteorology measurements; (3) Decontamination and relevant actions, collecting and treatment of fluid effluents; and and solid radioactive wastes [sr

Radiation protection at the RA Reactor in 1988, Part -2, RA reactor annual report

International Nuclear Information System (INIS)

Ninkovic, M.; Ajdacic, N.; Zaric, M.; Vukovic, Z.

1988-01-01

Radiation protection tasks which enable safe operation of the RA reactor, and are defined according the the legal regulations and IAEA safety recommendations are sorted into four categories in this report: (1) Control of the working environment, dosimetry at the RA reactor and radiation protection; (2) Radioactivity control in the vicinity of the reactor and meteorology measurements; (3) Decontamination and relevant actions, collecting and treatment of fluid effluents; and and solid radioactive wastes [sr

Properties of half-Heusler compounds TaIrGe by using first-principles calculations

Energy Technology Data Exchange (ETDEWEB)

Wei, JunHong [Henan Normal University, College of Physics and Information Engineering, Xinxiang, Henan (China); Henan Institute of Science and Technology, School of Mechanical and Electrical Engineering, Xinxiang, Henan (China); Wang, Guangtao [Henan Normal University, College of Physics and Information Engineering, Xinxiang, Henan (China)

2017-05-15

The electronic structures, optical and thermoelectric properties of ternary half-Heusler compound TaIrGe were investigated by using the first-principles and Boltzmann transport theory. Spin-orbit coupling (SOC) removed the degeneracy of VBM, and then decreased the Seebeck coefficients and power factor. From the compressive to tensile strain, the band gap gradually increases from 0.96 to 1.11 eV, accompanied by the absorption coefficient peak red-shift. The effective mass (m{sup *}{sub DOS}) of VBM and CBM gradually increases from the compressive to tensile strain, which enhances the Seebeck coefficient and power factor. Our results indicate that the electronic structures, optical and thermoelectric properties of TaIrGe can be effectively tuned by the strain and TaIrGe can be used as an important photoelectric and thermoelectric material in the future. (orig.)

Reproduction of the RA reactor fuel element fabrication

International Nuclear Information System (INIS)

Novakovic, M.

1961-12-01

This document includes the following nine reports: Final report on task 08/12 - testing the Ra reactor fuel element; design concept for fabrication of RA reactor fuel element; investigation of the microstructure of the Ra reactor fuel element; Final report on task 08/13 producing binary alloys with Al, Mo, Zr, Nb and B additions; fabrication of U-Al alloy; final report on tasks 08/14 and 08/16; final report on task 08/32 diffusion bond between the fuel and the cladding of the Ra reactor fuel element; Final report on task 08/33, fabrication of the RA reactor fuel element cladding; and final report on task 08/36, diffusion of solid state metals [sr

Exenatide improves both hepatic and adipose tissue insulin resistance: A dynamic positron emission tomography study.

Science.gov (United States)

Gastaldelli, Amalia; Gaggini, Melania; Daniele, Giuseppe; Ciociaro, Demetrio; Cersosimo, Eugenio; Tripathy, Devjit; Triplitt, Curtis; Fox, Peter; Musi, Nicolas; DeFronzo, Ralph; Iozzo, Patricia

2016-12-01

Glucagon-like peptide 1 (GLP-1) receptor agonists (GLP-1-RAs) act on multiple tissues, in addition to the pancreas. Recent studies suggest that GLP-1-RAs act on liver and adipose tissue to reduce insulin resistance (IR). Thus, we evaluated the acute effects of exenatide (EX) on hepatic (Hep-IR) and adipose (Adipo-IR) insulin resistance and glucose uptake. Fifteen male subjects (age = 56 ± 8 years; body mass index = 29 ± 1 kg/m 2 ; A1c = 5.7 ± 0.1%) were studied on two occasions, with a double-blind subcutaneous injection of EX (5 μg) or placebo (PLC) 30 minutes before a 75-g oral glucose tolerance test (OGTT). During OGTT, we measured hepatic (HGU) and adipose tissue (ATGU) glucose uptake with [ 18 F]2-fluoro-2-deoxy-D-glucose/positron emission tomography, lipolysis (RaGly) with [U- 2 H 5 ]-glycerol, oral glucose absorption (RaO) with [U- 13 C 6 ]-glucose, and hepatic glucose production (EGP) with [6,6- 2 H 2 ]-glucose. Adipo-IR and Hep-IR were calculated as (FFA 0-120min ) × (Ins 0-120min ) and (EGP 0-120min ) × (Ins 0-120min ), respectively. EX reduced RaO, resulting in reduced plasma glucose and insulin concentration from 0 to 120 minutes postglucose ingestion. EX decreased Hep-IR (197 ± 28 to 130 ± 37; P = 0.02) and increased HGU of orally administered glucose (23 ± 4 to 232 ± 89 [μmol/min/L]/[μmol/min/kg]; P = 0.003) despite lower insulin (23 ± 5 vs. 41 ± 5 mU/L; P < 0.02). EX enhanced insulin suppression of RaGly by decreasing Adipo-IR (23 ± 4 to 13 ± 3; P = 0.009). No significant effect of insulin was observed on ATGU (EX = 1.16 ± 0.15 vs. PLC = 1.36 ± 0.13 [μmol/min/L]/[μmol/min/kg]). Acute EX administration (1) improves Hep-IR, decreases EGP, and enhances HGU and (2) reduces Adipo-IR, improves the antilipolytic effect of insulin, and reduces plasma free fatty acid levels during OGTT. (Hepatology 2016;64:2028-2037). © 2016 by the American Association for the Study of Liver Diseases.

Measurements at the RA Reactor related to the VISA-2 project - Part 1, Start-up of the RA reactor and measurement of new RA reactor core parameters

International Nuclear Information System (INIS)

Markovic, H.

1962-07-01

The objective of the measurements was determining the neutron flux in the RA reactor core. Since the number of fuel channels is increased from 56 to 68 within the VISA-2 project, it was necessary to attain criticality of the RA reactor and measure the neutron flux properties. The 'program of RA reactor start-up' has been prepared separately and it is included in this report. Measurements were divided in two phases. First phase was measuring of the neutron flux after the criticality was achieved but at zero power. During phase two measurements were repeated at several power levels, at equilibrium xenon poisoning. This report includes experimental data of flux distributions and absolute values of the thermal and fast neutron flux in the RA reactor experimental channels and values of cadmium ratio for determining the neutron epithermal flux. Data related to calibration of regulatory rods for cold un poisoned core are included [sr

226Ra and 228Ra tracer study on nutrient transport in east coastal waters of Hainan Island, China

Directory of Open Access Journals (Sweden)

Ni Su

2011-06-01

Full Text Available Material fluxes (e.g., nutrients from coastal waters to offshore areas play an important role in controlling the water quality of the adjacent sea areas not only by increasing nutrient concentration but also by changing nutrient structures. In this study, naturally occurring isotopes, 226Ra and 228Ra, were measured with the alpha spectrometry in the Wenjiao-Wenchang and Wanquan estuaries and adjacent sea areas along the east coast of Hainan Island. The excess 226Ra and 228Ra activities were observed by comparison with the values derived from the conservative mixing of freshwater and seawater end-members in both estuaries. Using a one-dimensional diffusion model, the horizontal eddy diffusion coefficient of 3.16 x 105 cm2/s, for nutrients diffusing from their sources, was derived from 228Ra activities. Consequently, the corresponding nutrient fluxes flowing into the coastal waters were assessed. The results can provide useful information for the study of the mixing and exchange processes of coastal waters as well as dissoluble pollutant transport in this sea area.

IR thermocycler for centrifugal microfluidic platform with direct on-disk wireless temperature measurement system

Science.gov (United States)

Burger, J.; Gross, A.; Mark, D.; Roth, G.; von Stetten, F.; Zengerle, R.

2011-06-01

The direct on-disk wireless temperature measurement system [1,2] presented at μTAS 2010 was further improved in its robustness. We apply it to an IR thermocycler as part of a centrifugal microfluidic analyzer for polymerase chain reactions (PCR). This IR thermocycler allows the very efficient direct heating of aqueous liquids in microfluidic cavities by an IR radiation source. The efficiency factor of this IR heating system depends on several parameters. First there is the efficiency of the IR radiator considering the transformation of electrical energy into radiation energy. This radiation energy needs to be focused by a reflector to the center of the cavity. Both, the reflectors shape and the quality of the reflecting layer affect the efficiency. On the way to the center of the cavity the radiation energy will be diminished by absorption in the surrounding air/humidity and especially in the cavity lid of the microfluidic disk. The transmission spectrum of the lid material and its thickness is of significant impact. We chose a COC polymer film with a thickness of 150 μm. At a peak frequency of the IR radiator of ~2 μm approximately 85 % of the incoming radiation energy passes the lid and is absorbed within the first 1.5 mm depth of liquid in the cavity. As we perform the thermocycling for a PCR, after heating to the denaturation temperature of ~ 92 °C we need to cool down rapidly to the primer annealing temperature of ~ 55 °C. Cooling is realized by 3 ventilators venting air of room temperature into the disk chamber. Due to the air flow itself and an additional rotation of the centrifugal microfluidic disk the PCR reagents in the cavities are cooled by forced air convection. Simulation studies based upon analogous electrical models enable to optimize the disk geometry and the optical path. Both the IR heater and the ventilators are controlled by the digital PID controller HAPRO 0135 [3]. The sampling frequency is set to 2 Hz. It could be further increased up

Modeling the Energy Performance of LoRaWAN.

Science.gov (United States)

Casals, Lluís; Mir, Bernat; Vidal, Rafael; Gomez, Carles

2017-10-16

LoRaWAN is a flagship Low-Power Wide Area Network (LPWAN) technology that has highly attracted much attention from the community in recent years. Many LoRaWAN end-devices, such as sensors or actuators, are expected not to be powered by the electricity grid; therefore, it is crucial to investigate the energy consumption of LoRaWAN. However, published works have only focused on this topic to a limited extent. In this paper, we present analytical models that allow the characterization of LoRaWAN end-device current consumption, lifetime and energy cost of data delivery. The models, which have been derived based on measurements on a currently prevalent LoRaWAN hardware platform, allow us to quantify the impact of relevant physical and Medium Access Control (MAC) layer LoRaWAN parameters and mechanisms, as well as Bit Error Rate (BER) and collisions, on energy performance. Among others, evaluation results show that an appropriately configured LoRaWAN end-device platform powered by a battery of 2400 mAh can achieve a 1-year lifetime while sending one message every 5 min, and an asymptotic theoretical lifetime of 6 years for infrequent communication.

Modeling the Energy Performance of LoRaWAN

Directory of Open Access Journals (Sweden)

Lluís Casals

2017-10-01

Full Text Available LoRaWAN is a flagship Low-Power Wide Area Network (LPWAN technology that has highly attracted much attention from the community in recent years. Many LoRaWAN end-devices, such as sensors or actuators, are expected not to be powered by the electricity grid; therefore, it is crucial to investigate the energy consumption of LoRaWAN. However, published works have only focused on this topic to a limited extent. In this paper, we present analytical models that allow the characterization of LoRaWAN end-device current consumption, lifetime and energy cost of data delivery. The models, which have been derived based on measurements on a currently prevalent LoRaWAN hardware platform, allow us to quantify the impact of relevant physical and Medium Access Control (MAC layer LoRaWAN parameters and mechanisms, as well as Bit Error Rate (BER and collisions, on energy performance. Among others, evaluation results show that an appropriately configured LoRaWAN end-device platform powered by a battery of 2400 mAh can achieve a 1-year lifetime while sending one message every 5 min, and an asymptotic theoretical lifetime of 6 years for infrequent communication.

Įvairialyčiai lantano ir mangano oksido ir multiferoinio bismuto ferito heterodariniai

Directory of Open Access Journals (Sweden)

Bonifacas VENGALIS

2011-11-01

 @ (100¸200 nm, buvo auginami  magnetroninio dulkinimo būdu ant elektrai laidžių Nb legiruotų SrTiO3  padėklų, kurių temperatūra auginimo metu siekė 700 °C - 750 °C. Užauginti sluoksniai  buvo papildomai prisotinami deguonies atkaitinant juos deguonies atmosferoje (PO2 @ 105 Pa. BiFeO3 (BFO ir Bi0.9Nd0.1FeO3 (BNFO sluoksniai (d @ 200 nm - 250 nm buvo auginami kintamosios srovės (RF magnetroninio garinimo būdu ant SrTiO3(100, ZrO2 (YSZ , SrTiO3(100 (STON bei n- Si(111 padėklų  esant 650 °C - 700 °C temperatūrai ir Ar/O2 (1:1 dujų mišinio slėgiui P = 6 Pa - 10 Pa. Rentgeno difrakcijos tyrimai parodė, kad užauginti BNFO sluoksniai yra vienfaziai ir jų kristalografinės (100 plokštumos yra lygiagrečios su padėklo paviršiumi. Organinio Alq3 puslaidininkio sluoksniai (d @ 100 nm ÷ 300 nm buvo gaminami terminio garinimo būdu vakuume (p » 4´10-6 Torr. Heterodarinių elektrinėms charakteristikoms matuoti pro specialią diafragmą magnetroninio dulkinimo būdu buvo suformuojami (2´2 mm2 ploto metaliniai (Ag, Au elektrodai. Visais atvejais matuojant heterodarinių voltamperines charakteristikas per bandinius tekančios srovės kryptis buvo statmena padėklo plokštumai. Heterodarinių elektrinės bei magnetovaržinės savybės buvo tiriamos plačiame temperatūrų ruože (78 K - 400 K. Darinių, sudarytų iš manganito sluoksnio ant laidaus SrTiO3 padėklo, voltamperinės charakteristikos tiek kambario, tiek azoto temperatūroje buvo netiesinės ir nesimetrinės, t. y. pasižymėjo puslaidininkiniam diodui būdingomis lyginimo savybėmis. Priklausomai nuo srovės dydžio ir krypties buvo išmatuotos  tiek neigiamos, tiek teigiamos jų magnetovaržos vertės. Alq3/LSMO darinių voltamperinės charakteristikos nedaug priklausė nuo srovės krypties, tačiau jų magnetovaržos vertės buvo palyginti didelės  (apie 11 %,  kai T = 240 K ir B = 1 T. Netiesinės elektrinės heterodarinių savyb

Diphosphine- and CO-Induced Fragmentation of Chloride-bridged Dinuclear Complex and Cp*Ir(mu-Cl)(3)Re(CO)(3) and Attempted Synthesis of Cp*Ir(mu-Cl)(3)Mn(CO)(3): Spectroscopic Data and X-ray Diffraction Structures of the Pentamethylcyclopentadienyl Compounds [Cp*IrCl{(Z)-Ph2PCH = CHPPh2}][Cl]center dot 2CHCl(3) and Cp*Ir(CO)Cl-2

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