WorldWideScience

Sample records for polyether concentration measurements

  1. Lithium isotope effect in the extraction systems of polyethers: effect of salt concentration

    International Nuclear Information System (INIS)

    Fang Shengqiang; Fu Lian

    1991-01-01

    Separation factors of lithium isotopes at 20 deg C were determined in the extraction systems of B15C5-CHCl 3 /LiBr-H 2 O. The initial concentration of LiBr was controlled in the extent of more than 2 mol/l. It may be established that the increase of LiBr concentration causes a remarkable increase of the separation factor. The essence of this effect due to the change in salt concentration was discussed in connection with examination of relevant phenomena in literature. It can be concluded that the relationship between α and Cm, the concentration of lithium salt, is dependent on K Q and K P express respectively, lithium isotope exchange equilibrium constants between Li-crownether complex and hydrated lithium ion for lithium concentration less than 1-2 mol/l, and between lithium salt ion pair and hydrated lithium ion for lithium concentration more than 2 mol/l in aqueous phase

  2. FK concentrator outdoor measurements

    OpenAIRE

    Hernández Sanz, Maikel; Vilaplana, J., J.; Benitez Gimenez, Pablo; Mohedano,, Rubén; Zamora Herranz, Pablo; Miñano Dominguez, Juan Carlos; Mendes Lopes, Joao

    2013-01-01

    The FK is a two-stage optical concentrator for CPV, composed by a Fresnel lens working as POE and a refractive element working as SOE. Both elements perform Köhler integration, for uniform irradiance purposes. The FK has demonstrated that compares very well with other Fresnel-based concentrator optics. Recent on-sun measurements carried out on an FK mono-module prototype have already shown outstanding results, achieving electrical efficiencies over 34%. Further optimization of optical design ...

  3. The enzymology of polyether biosynthesis.

    Science.gov (United States)

    Liu, Tiangang; Cane, David E; Deng, Zixin

    2009-01-01

    Polyether ionophore antibiotics are a special class of polyketides widely used in veterinary medicine, and as food additives in animal husbandry. In this article, we review current knowledge about the mechanism of polyether biosynthesis, and the genetic and biochemical strategies used for its study. Several clear differences distinguish it from traditional type I modular polyketide biosynthesis: polyether backbones are assembled by modular polyketide synthases but are modified by two key enzymes, epoxidase and epoxide hydrolase, to generate the product. All double bonds involved in the oxidative cyclization in the polyketide backbone are of E geometry. Chain release in the polyether biosynthetic pathway requires a special type II thioesterase which specifically hydrolyzes the polyether thioester. All these discoveries should be very helpful for a deep understanding of the biosynthetic mechanism of this class of important natural compounds, and for the targeted engineering of polyether derivatives.

  4. The effect of polyether functional polydimethylsiloxane on surface and thermal properties of waterborne polyurethane

    Science.gov (United States)

    Zheng, Guikai; Lu, Ming; Rui, Xiaoping

    2017-03-01

    Waterborne polyurethanes (WPU) modified with polyether functional polydimethylsiloxane (PDMS) were synthesized by pre-polymerization method using isophorone diisocyanate (IPDI) and 1,4-butanediol (BDO) as hard segments and polybutylene adipate glycol (PBA) and polyether functional PDMS as soft segments. The effect of polyether functional PDMS on phase separation, thermal properties, surface properties including surface composition, morphology and wettability were investigated by FTIR, contact angle measurements, ARXPS, SEM-EDS, AFM, TG and DSC. The results showed that the compatibility between urethane hard segment and PDMS modified with polyether was good, and there was no distinct phase separation in both bulk and surface of WPU films. The degradation temperature and low temperature flexibility increased with increasing amounts of polyether functional PDMS. The enrichment of polyether functional PDMS with low surface energy on the surface imparted excellent hydrophobicity to WPU films.

  5. Polymerization of polyethers initiated by irradiation with high power pulsed electron beams

    International Nuclear Information System (INIS)

    Gerber, V.D.; Tolkachev, V.S.; Chmukh, V.N.

    1982-01-01

    Air oxygen effect on thin-layer polymerization of polyethers, initiated by irradiation with powerful pulse electron beams is studied using the method of IR-spectrophotometry. The analysis of experimental data has shown that in polyether surface layer polymerization is suppressed by oxygen, concentration of which in the layer remains stable at the expense of diffusion from air during two consequent irradiation pulses

  6. Hydrogen storage by functionalised Poly(ether ether ketone)

    Energy Technology Data Exchange (ETDEWEB)

    Pedicini, R.; Giacoppo, G.; Carbone, A.; Passalacqua, E. [CNR-ITAE, Messina (Italy). Inst. for Advanced Energy Technologies

    2010-07-01

    In this work a functionalised polymer was studied as potential material for hydrogen storage in solid state. A Poly(ether ether ketone) (PEEK) matrix was modified by a manganese oxide in situ formation. Here we report the functionalisation process and the preliminary results on hydrogen storage capability of the synthesised polymer. The polymer was characterized by Scanning Electron Microscopy, X-ray diffraction, Transmission Electron Microscopy and Gravimetric Hydrogen Adsorption measurements. In the functionalised PEEK, morphological changes occur as a function of oxide precursor concentration and reaction time. Promising results by gravimetric measurements were obtained with a hydrogen sorption of 0.24%wt/wt at 50 C and 60 bar, moreover, reversibility hydrogen adsorption and desorption in a wide range of both temperature and pressure was confirmed. (orig.)

  7. Tunable, antibacterial activity of silicone polyether surfactants.

    Science.gov (United States)

    Khan, Madiha F; Zepeda-Velazquez, Laura; Brook, Michael A

    2015-08-01

    Silicone surfactants are used in a variety of applications, however, limited data is available on the relationship between surfactant structure and biological activity. A series of seven nonionic, silicone polyether surfactants with known structures was tested for in vitro antibacterial activity against Escherichia coli BL21. The compounds varied in their hydrophobic head, comprised of branched silicone structures with 3-10 siloxane linkages and, in two cases, phenyl substitution, and hydrophilic tail of 8-44 poly(ethylene glycol) units. The surfactants were tested at three concentrations: below, at, and above their Critical Micelle Concentrations (CMC) against 5 concentrations of E. coli BL21 in a three-step assay comprised of a 14-24h turbidometric screen, a live-dead stain and viable colony counts. The bacterial concentration had little effect on antibacterial activity. For most of the surfactants, antibacterial activity was higher at concentrations above the CMC. Surfactants with smaller silicone head groups had as much as 4 times the bioactivity of surfactants with larger groups, with the smallest hydrophobe exhibiting potency equivalent to sodium dodecyl sulfate (SDS). Smaller PEG chains were similarly associated with higher potency. These data link lower micelle stability and enhanced permeability of smaller silicone head groups to antibacterial activity. The results demonstrate that simple manipulation of nonionic silicone polyether structure leads to significant changes in antibacterial activity. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Safety Assessment of Polyether Lanolins as Used in Cosmetics.

    Science.gov (United States)

    Becker, Lillian C; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel C; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan; Heldreth, Bart

    The Cosmetic Ingredient Review (CIR) Expert Panel (Panel) assessed the safety of 39 polyether lanolin ingredients as used in cosmetics. These ingredients function mostly as hair conditioning agents, skin conditioning agent-emollients, and surfactant-emulsifying agents. The Panel reviewed available animal and clinical data, from previous CIR safety assessments of related ingredients and components. The similar structure, properties, functions, and uses of these ingredients enabled grouping them and using the available toxicological data to assess the safety of the entire group. The Panel concluded that these polyether lanolin ingredients are safe in the practices of use and concentration as given in this safety assessment.

  9. 40 CFR 721.405 - Polyether acrylate.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyether acrylate. 721.405 Section... § 721.405 Polyether acrylate. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polyether acrylate (PMN P-95-666) is subject to...

  10. Extrusion-mixing compared with hand-mixing of polyether impression materials?

    Science.gov (United States)

    McMahon, Caroline; Kinsella, Daniel; Fleming, Garry J P

    2010-12-01

    The hypotheses tested were two-fold (a) whether altering the base:catalyst ratio influences working time, elastic recovery and strain in compression properties of a hand-mixed polyether impression material and (b) whether an extrusion-mixed polyether impression material would have a significant advantage over a hand-mixed polyether impression material mixed to the optimum base:catalyst ratio. The polyether was hand-mixed at the optimum (manufacturers recommended) base:catalyst ratios (7:1) and further groups were made by increasing or decreasing the catalyst length by 25%. Additionally specimens were also made from an extrusion-mixed polyether impression material and compared with the optimum hand-mixed base:catalyst ratio. A penetrometer assembly was used to measure the working time (n=5). Five cylindrical specimens for each hand-mixed and extrusion mixed group investigated were employed for elastic recovery and strain in compression testing. Hand-mixing polyether impression materials with 25% more catalyst than that recommended significantly decreased the working time while hand-mixing with 25% less catalyst than that recommended significantly increased the strain in compression. The extrusion-mixed polyether impression material provided similar working time, elastic recovery and strain in compression to the hand-mixed polyether mixed at the optimum base:catalyst ratio.

  11. High-k 3D-barium titanate foam/phenolphthalein poly(ether sulfone)/cyanate ester composites with frequency-stable dielectric properties and extremely low dielectric loss under reduced concentration of ceramics

    Science.gov (United States)

    Zheng, Longhui; Yuan, Li; Guan, Qingbao; Liang, Guozheng; Gu, Aijuan

    2018-01-01

    Higher dielectric constant, lower dielectric loss and better frequency stability have been the developing trends for high dielectric constant (high-k) materials. Herein, new composites have been developed through building unique structure by using hyperbranched polysiloxane modified 3D-barium titanate foam (BTF) (BTF@HSi) as the functional fillers and phenolphthalein poly(ether sulfone) (cPES)/cyanate ester (CE) blend as the resin matrix. For BTF@HSi/cPES/CE composite with 34.1 vol% BTF, its dielectric constant at 100 Hz is as high as 162 and dielectric loss is only 0.007; moreover, the dielectric properties of BTF@HSi/cPES/CE composites exhibit excellent frequency stability. To reveal the mechanism behind these attractive performances of BTF@HSi/cPES/CE composites, three kinds of composites (BTF/CE, BTF/cPES/CE, BTF@HSi/CE) were prepared, their structure and integrated performances were intensively investigated and compared with those of BTF@HSi/cPES/CE composites. Results show that the surface modification of BTF is good for preparing composites with improved thermal stability; while introducing flexible cPES to CE is beneficial to fabricate composites with good quality through effectively blocking cracks caused by the stress concentration, and then endowing the composites with good dielectric properties at reduced concentration of ceramics.

  12. Polyether-polyester graft copolymer

    Science.gov (United States)

    Bell, Vernon L. (Inventor)

    1987-01-01

    Described is a polyether graft polymer having improved solvent resistance and crystalline thermally reversible crosslinks. The copolymer is prepared by a novel process of anionic copolymerization. These polymers exhibit good solvent resistance and are well suited for aircraft parts. Previous aromatic polyethers, also known as polyphenylene oxides, have certain deficiencies which detract from their usefulness. These commercial polymers are often soluble in common solvents including the halocarbon and aromatic hydrocarbon types of paint thinners and removers. This limitation prevents the use of these polyethers in structural articles requiring frequent painting. In addition, the most popular commercially available polyether is a very high melting plastic. This makes it considerably more difficult to fabricate finished parts from this material. These problems are solved by providing an aromatic polyether graft copolymer with improved solvent resistance and crystalline thermally reversible crosslinks. The graft copolymer is formed by converting the carboxyl groups of a carboxylated polyphenylene oxide polymer to ionic carbonyl groups in a suitable solvent, reacting pivalolactone with the dissolved polymer, and adding acid to the solution to produce the graft copolymer.

  13. Pengerasan Pada Bahan Cetak Elastomer Polyether

    OpenAIRE

    Azree Zayani M.S.

    2011-01-01

    Bahan cetak polyether merupakan bahan elastomer yang digunakan di kedokteran gigi. Terdapat empat kelas menurut konsistensi dan viskositas yaitu (1) light body (2)medium atau regular body (3) heavy body: dan (4) Putty. Komposisi bahan cetak polyether terdiri dari pasta base dan pasta katalis. Pasta base mengandung polimer polyether, kolloidal silika sebagai bahan pengisi, dan plastisizer yaitu glikoeter atau phthalate. Pasta katalis mengandung alkil aromatik sulfonat ditambah dengan baha...

  14. Ultraviolet-induced surface grafting of octafluoropentyl methacrylate on polyether ether ketone for inducing antibiofilm properties.

    Science.gov (United States)

    Amdjadi, Parisa; Nojehdehian, Hanieh; Najafi, Farhood; Ghasemi, Amir; Seifi, Massoud; Dashtimoghadam, Erfan; Fahimipour, Farahnaz; Tayebi, Lobat

    2017-07-01

    Since octafluoropentyl methacrylate is an antifouling polymer, surface modification of polyether ether ketone with octafluoropentyl methacrylate is a practical approach to obtaining anti-biofilm biocompatible devices. In the current study, the surface treatment of polyether ether ketone by the use of ultraviolet irradiation, so as to graft (octafluoropentyl methacrylate) polymer chains, was initially implemented and then investigated. The Fourier-transform infrared and nuclear magnetic resonance spectra corroborated the appearance of new signals associated with the fluoroacrylate group. Thermogravimetric curves indicated enhanced asymmetry in the polymer structure due to the introduction of the said new groups. Measuring the peak area in differential scanning calorimetry experiments also showed additional bond formation. Static water contact angle measurements indicated a change in wettability to the more hydrophobic surface. The polyether ether ketone-octafluoropentyl methacrylate surface greatly reduced the protein adsorption. This efficient method can modulate and tune the surface properties of polyether ether ketone according to specific applications.

  15. Recalculation of measured fuel nuclide concentrations

    International Nuclear Information System (INIS)

    Moeller, W.

    1984-01-01

    The concentrations and concentration ratios of heavy fuel nuclides determined in the Central Institute for Nuclear Research Rossendorf on the basis of destructive burnup measurements are compared with the results of microburnup calculations. The possibility is discussed to improve the results by taking into account the spectral characteristics at the positions of the measuring samples. (author)

  16. Continuous measurements of outdoor radon concentrations

    International Nuclear Information System (INIS)

    Iida, T.; Ikebe, Y.; Suzuki, K.; Ueno, K.; Komura, K.; Kato, I.; Jin Yihe

    1993-01-01

    The authors studied and developed an electrostatic 222 Rn monitor and have measured continuously outdoor radon ( 222 Rn) concentrations at Nagoya University since 1985. Four 222 Rn monitors were newly constructed to measure outdoor 222 Rn concentrations at other locations. The 222 Rn concentrations at Nagoya and Kasugai show a clear diurnal variation in autumn, and a seasonal pattern of a spring-summer minimum and a autumn-winter maximum. The results at Toki are the same pattern as that at Nagoya except spring. The concentrations at Kanazawa show a slight seasonal variation. A clear diurnal variation is observed in summer. (4 figs.)

  17. Concentration and limit behaviors of stationary measures

    Science.gov (United States)

    Huang, Wen; Ji, Min; Liu, Zhenxin; Yi, Yingfei

    2018-04-01

    In this paper, we study limit behaviors of stationary measures of the Fokker-Planck equations associated with a system of ordinary differential equations perturbed by a class of multiplicative noise including additive white noise case. As the noises are vanishing, various results on the invariance and concentration of the limit measures are obtained. In particular, we show that if the noise perturbed systems admit a uniform Lyapunov function, then the stationary measures form a relatively sequentially compact set whose weak∗-limits are invariant measures of the unperturbed system concentrated on its global attractor. In the case that the global attractor contains a strong local attractor, we further show that there exists a family of admissible multiplicative noises with respect to which all limit measures are actually concentrated on the local attractor; and on the contrary, in the presence of a strong local repeller in the global attractor, there exists a family of admissible multiplicative noises with respect to which no limit measure can be concentrated on the local repeller. Moreover, we show that if there is a strongly repelling equilibrium in the global attractor, then limit measures with respect to typical families of multiplicative noises are always concentrated away from the equilibrium. As applications of these results, an example of stochastic Hopf bifurcation and an example with non-decomposable ω-limit sets are provided. Our study is closely related to the problem of noise stability of compact invariant sets and invariant measures of the unperturbed system.

  18. Measurements of natural 41Ca concentrations

    International Nuclear Information System (INIS)

    Steinhof, A.

    1989-05-01

    Atomic mass spectroscopic examinations on 41 Ca were carried out in the UNILAC accelerator. A sensitivity of about 10 -15 was achieved. This would allow the measurement of present natural 41 Ca concentrations as soon as the problem of the transmission determination is solved. In this respect suggestions were worked out and their feasibility discussed. The detection of 41 Ca-ions is especially free of background when high UNILAC-energies are applied. An estimation showed a background level corresponding with a 41 Ca concentration of less then 10 -17 referred to 40 Ca. Besides an independent concept for the electromagnetic concentration of 41 Ca with variable concentration factors was developed. After being concentrated up to 50 respectively 25 times the initial concentration in the GSI mass separator, the 41 Ca concentration of three recent deer bones found in the Odenwald was measured by atomic mass spectroscopy in the 14UD-Pelletron Tandem in Rehovot (Israel). The measured 41 Ca concentrations ranged between 10 -14 to 10 -13 with consideration of the concentration factor. A theoretical study of the 41 Ca production in the earth's surface based on cosmic radiation illustrates the influence of trace elements on the neutron flux and thus on the 41 Ca production. This influence might be a possible explanation for the observed amplitude of variation of the 41 Ca concentration in recent bones which are of decisive importance for the feasibility of 41 Ca-related dating. In this work a method is suggested that does not depend on the amplitude of variation mentioned above and which would allow the determination of the erosion rate of rocks by its 41 Ca concentrations. (orig./HP) [de

  19. Measurement of tritium concentration in urine

    International Nuclear Information System (INIS)

    Sekiyama, Shigenobu; Deshimaru, Takehide

    1979-01-01

    Concerning the safety management of the advanced thermal reactor ''Fugen'', the internal exposure management for tritium is important, because heavy water is used as the moderator in the reactor, and tritium is produced in the heavy water. Tritium is the radioactive nuclide with the maximum β-ray energy of 18 keV, and the radiation exposure is limited to the internal exposure in human bodies, as tritium is taken in through the skin and by breathing. The tritium concentration in urine of the operators of the Fugen plant was measured. As for tritium measurement, the analysis of raw urine, the analysis after passing through mixed ion exchange resin and the analysis after distillation are applied. The scintillator, the liquid scintillation counter, the ion exchange resin and the distillator are introduced. The preliminary survey was conducted on the urine sample, the scintillator the calibration, etc. The measuring condition, the measurement of efficiency, and the limitation of detection with various background are explained, with the many experimental data and the calculating formula. Concerning the measured tritium concentration in urine, the tritium concentrations in distilled urine, raw urine and the urine refined with ion exchange resin were compared, and the correlation formulae are presented. The actual tritium concentration value in urine was less than 50 pci/ml. The measuring methods of raw urine and the urine refined with ion exchange resin are adequate as they are quick and accurate. (Nakai, Y.)

  20. Polyether ether ketone film. Polyether ether ketone film

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, S. (Sumitomo Chemical Co. Ltd., Tokyo (Japan))

    1990-07-05

    The characteristics and the film making process of polyether ether ketone (PEEK) resin, and the characteristics and the applications of PEEK film, are described. PEEK is aromatic polyketone with super thermal resistance. Though it is a crystalline polymer of which the crystallinity is controlled to 48% in a highest degree, it has also amorphous property, thus it shows unique property. The characteristics of PEEK resin are found in thermal resistance, incombusti-bility, transparency, chemical resistance, light resistance and radiation resistance. As for the film making process, casting method by T-die is generally adopted. The general properties of PEEK film are excellent in high thermal resistance, good electrical properties, chemical resistance, hydrolysis resistance, radiation resistance and imcombusti-bility. In the application of PEEK film, new development is expected in following fields; a high performance composite, flexible print substrate with high thermal resistance, insulating tape with thermal resistance, and a general film in the nuclear energy industry. 5 figs., 5 tabs.

  1. The PROMETHEE multiple criteria decision making analysis for selecting the best membrane prepared from sulfonated poly(ether ketone)s and poly(ether sulfone)s for proton exchange membrane fuel cell

    International Nuclear Information System (INIS)

    Nikouei, Mohammad Ali; Oroujzadeh, Maryam; Mehdipour-Ataei, Shahram

    2017-01-01

    Proton exchange membrane as the heart of fuel cell has been the topic of many research activities in recent years. Finding a suitable alternative for Nafion membranes is one of the most important issues of interest. This study is dedicated to sulfonated poly(ether ketone) and poly(ether sulfone) membranes. For synthesis of these two groups of polymers, two different isomeric biphenols (meta- and para-) were used and each group of membranes with three different degree of sulfonation (25, 35, and 45%) was synthesized. In this way, twelve different membrane samples were obtained and their properties were evaluated. Since each membrane had some strong and some weak points of properties in comparison to the other ones, using a rational analysis for choosing the best membrane between prepared samples was inevitable. For this purpose a PROMETHEE based multiple criteria decision making approach was applied and for evaluation of the weight of each criterion, Shannon entropy method was used. Final results showed that poly(ether ketone) membranes in selected criteria were better than poly(ether sulfone) membranes and as expected, membranes with the highest degree of sulfonation (45%) were placed at the top ranking levels. - Highlights: • Sulfonated poly(ether ketone)s and Poly(ether sulfone)s were synthesized. • Related membranes for PEMFC were prepared. • The properties of membranes were measured. • Multiple criteria decision making approach was used to ranking the membranes. • PROMETHEE based approach selected poly(ether ketone)s as better choices.

  2. Polyether complexes of groups 13 and 14.

    Science.gov (United States)

    Swidan, Ala'aeddeen; Macdonald, Charles L B

    2016-07-21

    Notable aspects of the chemistry of complexes of polyether ligands including crown ethers, cryptands, glycols, glymes, and related polyether ligands with heavier group 13 and 14 elements are reviewed with a focus on results from 2005 to the present. The majority of reported polyether complexes contain lead(ii) and thallium(i) but recent breakthroughs in regard to the preparation of low oxidation state reagents of the lighter congeners have allowed for the generation of complexes containing indium(i), gallium(i), germanium(ii), and even silicon(ii). The important roles of ligand size, donor types, and counter anions in regard to the chemical properties of the polyether complexes is highlighted. A particular focus on the structural aspects of the numerous coordination complexes provides a rationale for some of the spectacular contributions that such compounds have made to Modern Main Group Chemistry.

  3. Measurement of concentration of heavy water

    International Nuclear Information System (INIS)

    Tsukamoto, Yuichi; Kondo, Mitsuo; Sakurai, Naoyuki

    1979-01-01

    The concentration of heavy water is measured as one of the technical management in the Fugen plant. The heavy water is used as the moderator in the reactor. The measuring method depends on the theory of light absorption. The light absorption range of heavy water spreads from near infrared to infrared zone. The near infrared absorption was adopted for the purpose, as the absorption is much larger in infrared zone, and the measurement has to be conducted, limiting the apparent absorption. This measuring method is available to determine the concentration of heavy water in the broad range exactly. The preparation of heavy water sample and the measurement of the absorption spectra of near infrared ray are explained, as the experimental procedure. The sample cell was made of quartz, and the spectroscope was the Hitachi 323 type. The resolving power is 100 nm and 27 nm for the wave length of 1000 nm and 2500 nm, respectively. Concerning the measured results, the absorption was recorded in the wave length range from 600 nm to 2600 nm, and for the heavy water concentration range from 0 to 99.77 wt. %. The peaks of absorption were located at the wave length of 1450, 1660, 1920, 1970, 2020 and 2600 nm. The three kinds of fundamental vibration mode of the molecules of both light and heavy water are shown, and the peaks belong to H 2 O, HDO and D 2 O, respectively. The relation between the absorption and the heavy water concentration, and that between the transmissivity and the wave length are shown, when the cell thickness was varied to 5 mm and 20 mm, and the heavy water concentration to 21%, 62% and 99.85%. (Nakai, Y.)

  4. Wettability changes in polyether impression materials subjected to immersion disinfection.

    Science.gov (United States)

    Shetty, Shweta; Kamat, Giridhar; Shetty, Rajesh

    2013-07-01

    Disinfection of impression materials prevents cross-contamination; however, the disinfectants may alter the wettability property. The purpose of this investigation was to evaluate the wettability changes of polyether impression material after immersing in four different chemical disinfectant solutions for a period of 10 min and 30 min, respectively. A total of 45 samples of polyether dental impression material (Impregum soft, 3MESPE, St. Paul, MN, USA) were randomly divided into nine groups with five specimens each. Each specimen was disc shaped, flat of 32 mm diameter and 3 mm thickness. The samples were immersed in four disinfectant solutions: 2% Glutaraldehyde, 5% sodium hypochlorite, 0.05% iodophor, and 5.25% phenol for 10 min and 30 min, respectively. The control was without disinfection. Wettability of the samples was assessed by measuring the contact angle by using the Telescopic Goniometer. Data were subjected to analysis of variance (Fisher's test) and Tukey's post hoc test for multiple comparisons at 5% level of significance. The contact angle of 20.21° ± 0.22° were recorded in the control samples. After 10 min, the samples that were immersed in 5% sodium hypochlorite and 5.25% phenol showed significant statistical increase in the contact angle as compared to the control (P polyether material. Within the limitations of the study, 2% glutaraldehyde proved safe for 10 min of immersion disinfection while 0.05% iodophor holds promise as an effective disinfectant without affecting the wettability of the material.

  5. Electrospray ionization tandem mass spectrometry of ammonium cationized polyethers.

    Science.gov (United States)

    Nasioudis, Andreas; Heeren, Ron M A; van Doormalen, Irene; de Wijs-Rot, Nicolette; van den Brink, Oscar F

    2011-05-01

    Quaternary ammonium salts (Quats) and amines are known to facilitate the MS analysis of high molar mass polyethers by forming low charge state adduct ions. The formation, stability, and behavior upon collision-induced dissociation (CID) of adduct ions of polyethers with a variety of Quats and amines were studied by electrospray ionization quadrupole time-of-flight, quadrupole ion trap, and linear ion trap tandem mass spectrometry (MS/MS). The linear ion trap instrument was part of an Orbitrap hybrid mass spectrometer that allowed accurate mass MS/MS measurements. The Quats and amines studied were of different degree of substitution, structure, and size. The stability of the adduct ions was related to the structure of the cation, especially the amine's degree of substitution. CID of singly/doubly charged primary and tertiary ammonium cationized polymers resulted in the neutral loss of the amine followed by fragmentation of the protonated product ions. The latter reveals information about the monomer unit, polymer sequence, and endgroup structure. In addition, the detection of product ions retaining the ammonium ion was observed. The predominant process in the CID of singly charged quaternary ammonium cationized polymers was cation detachment, whereas their doubly charged adduct ions provided the same information as the primary and tertiary ammonium cationized adduct ions. This study shows the potential of specific amines as tools for the structural elucidation of high molar mass polyethers. © American Society for Mass Spectrometry, 2011

  6. Competitive solvent extraction of alkaline-earth cations into chloroform by lipophilic acyclic polyether dicarboxylic acids

    International Nuclear Information System (INIS)

    Kang, S.I.; Czech, A.; Czech, B.P.; Stewart, L.E.; Bartsch, R.A.

    1985-01-01

    Competitive solvent extraction of alkaline-earth cations from aqueous solutions into chloroform by a series of lipophilic acyclic polyether dicarboxylic acids is reported. The influence of polyether chain length and of terminal carboxylic acid group variation upon extraction selectivity and efficiency is assessed. In the competitive extraction of concentrated magnesium, calcium, strontium and barium chloride solutions, one complexing agent exhibits pronounced selectivity for barium with Ba 2+ /S 2+ = 50, Ba 2+ /Ca 2+ = 250, and no detectable Mg 2+ extraction. 20 references, 3 figures, 1 table

  7. Portable method of measuring gaseous acetone concentrations.

    Science.gov (United States)

    Worrall, Adam D; Bernstein, Jonathan A; Angelopoulos, Anastasios P

    2013-08-15

    Measurement of acetone in human breath samples has been previously shown to provide significant non-invasive diagnostic insight into the control of a patient's diabetic condition. In patients with diabetes mellitus, the body produces excess amounts of ketones such as acetone, which are then exhaled during respiration. Using various breath analysis methods has allowed for the accurate determination of acetone concentrations in exhaled breath. However, many of these methods require instrumentation and pre-concentration steps not suitable for point-of-care use. We have found that by immobilizing resorcinol reagent into a perfluorosulfonic acid polymer membrane, a controlled organic synthesis reaction occurs with acetone in a dry carrier gas. The immobilized, highly selective product of this reaction (a flavan) is found to produce a visible spectrum color change which could measure acetone concentrations to less than ppm. We here demonstrate how this approach can be used to produce a portable optical sensing device for real-time, non-invasive acetone analysis. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. 40 CFR 721.3710 - Polyether modified fatty acids (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyether modified fatty acids... Specific Chemical Substances § 721.3710 Polyether modified fatty acids (generic). (a) Chemical substance... Polyether modified fatty acids (PMN P-99-0435) is subject to reporting under this section for the...

  9. 21 CFR 177.2430 - Polyether resins, chlorinated.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyether resins, chlorinated. 177.2430 Section 177... Components of Articles Intended for Repeated Use § 177.2430 Polyether resins, chlorinated. Chlorinated polyether resins may be safely used as articles or components of articles intended for repeated use in...

  10. Apparatus for measuring a concentration of radioactivity

    International Nuclear Information System (INIS)

    Tabuchi, H.; Ogushi, A.

    1978-01-01

    Disclosed is an apparatus for measuring concentration of radioactivity in a fluid circulating in a cooling system or a disposal system, etc., of a nuclear power plant (e.g. coolant), the apparatus having a plurality of sampling tubes with different diameters depending on the intensities of radioactivity, and the sampling tubes having valves for switching from one fluid to another fluid. The sampling tubes are connected to the system to a discharge pipe, and are disposed in the proximity of a radiation detector adapted to issue a signal representative of radiation. The issued signal is supplied to a multichannel pulse height analyzer and a data processing system providing an indication of the concentrations of radioactivities for respective radionuclides

  11. Poly(ether amide) segmented block copolymers with adipicacid based tetra amide segments

    NARCIS (Netherlands)

    Biemond, G.J.E.; Feijen, Jan; Gaymans, R.J.

    2007-01-01

    Poly(tetramethylene oxide)-based poly(ether ester amide)s with monodisperse tetraamide segments were synthesized. The tetraamide segment was based on adipic acid, terephthalic acid, and hexamethylenediamine. The synthesis method of the copolymers and the influence of the tetraamide concentration,

  12. Optical anisotropy, molecular orientations, and internal stresses in thin sulfonated poly(ether ether ketone) films

    NARCIS (Netherlands)

    Koziara, B.T.; Nijmeijer, K.; Benes, N.E.

    2015-01-01

    The thickness, the refractive index, and the optical anisotropy of thin sulfonated poly(ether ether ketone) films, prepared by spin-coating or solvent deposition, have been investigated with spectroscopic ellipsometry. For not too high polymer concentrations (≤5 wt%) and not too low spin speeds

  13. Optical anisotropy, molecular orientations, and internal stresses in thin sulfonated poly(ether ether ketone) films

    NARCIS (Netherlands)

    Koziara, Beata; Nijmeijer, Dorothea C.; Benes, Nieck Edwin

    2015-01-01

    The thickness, the refractive index, and the optical anisotropy of thin sulfonated poly(ether ether ketone) films, prepared by spin-coating or solvent deposition, have been investigated with spectroscopic ellipsometry. For not too high polymer concentrations (B5 wt%) and not too low spin speeds

  14. Measurements of radon concentrations in dwelling houses

    International Nuclear Information System (INIS)

    Birkholz, W.; Klink, T.

    1993-01-01

    Radon and its daughter products gain in importance in health protection and radiation safety. Especially in the southern region of Saxony radon concentrations in dwellings may be high by former silver and uranium mines. We found radon contents of about 20.000 Bq/m 3 in dwellings. To redevelop such houses it is necessary to know intrude path of radon. In present work we studied different measuring systems, active and passive detectors, short and long term integrating devices. By means of investigation of radon sources several redeveloping methods are rates as well from radiological as from civil engineering point of view. (author)

  15. Biosynthetic machinery of ionophore polyether lasalocid: enzymatic construction of polyether skeleton.

    Science.gov (United States)

    Minami, Atsushi; Oguri, Hiroki; Watanabe, Kenji; Oikawa, Hideaki

    2013-08-01

    Diversity of natural polycyclic polyethers originated from very simple yet versatile strategy consisting of epoxidation of linear polyene followed by epoxide opening cascade. To understand two-step enzymatic transformations at molecular basis, a flavin containing monooxygenase (EPX) Lsd18 and an epoxide hydrolase (EH) Lsd19 were selected as model enzymes for extensive investigation on substrate specificity, catalytic mechanism, cofactor requirement and crystal structure. This pioneering study on prototypical lasalocid EPX and EH provides insight into detailed mechanism of ionophore polyether assembly machinery and clarified remaining issues for polyether biosynthesis. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Measurement of radon activity concentration in buildings

    International Nuclear Information System (INIS)

    Godet, J.L.; Perrin, M.L.; Pineau, C.; Dechaux, E.

    2010-01-01

    Radon exposure, along with medical-related exposure, is the leading source of exposure to ionising radiation for the French population. Measurement campaigns are done in the action plan, drawn up by the French nuclear safety authority (ASN), in cooperation with the French directorate for housing, town planning and countryside (DHUP), the French radiation protection and nuclear safety institute (IRSN), the French health monitoring institute (InVS) and the French scientific and technical centre for construction (CSTB). The review of 2005-2008 measurement campaign shows that of the 7356 buildings screened, 84.8% had activity concentration levels below the 400 Bq/m 3 action level. For the other buildings (15.2%), action will be required to reduce human exposure to radon, possibly including building renovation/redevelopment work. In the 1999-2002 measurement campaign,12% of the 13,000 buildings screened had a radon activity concentration level higher than 400 Bq/m 3 . In addition, the ASN and the French general directorate of labour (DGT) are continuing to work on drawing up regulations for occupational risk management. The second national health and environment plan (PNSE 2) was published on 26 June 2009. It follows on from the actions initiated in PNSE 1, a document provided for under the Public Health Act dated 9 August 2004 and under the French 'Grenelle' environmental agreements. On the basis of guidelines laid out in PNSE 2, a radon action plan for 2009-2012 will be drawn up, enabling some of the actions to be continued, particularly in the fields of new building projects and dwellings. (author)

  17. Device for measuring the tritium concentration in a measuring gas

    International Nuclear Information System (INIS)

    Koran, P.

    1987-01-01

    The measuring gas is brought into contact via a measuring gas path with a diaphragm permeable to water, which separates the measuring gas path from a counter gas path leading to a proportional detector. The measuring gas path and the counter gas path are in counterflow in the area of diaphragm. The preferably hose diaphragm consists of a well-known ion exchange material, which can be used for gas drying purposes, which is permeable to water and tritium compounds similar to water, but is impermeable to other gases and liquids contained in air, particularly rare gases. In this way, the tritium concentration can be measured with great rare gas suppression. (orig./HP) [de

  18. Polyether matrices for lithium generators; Matrices polyethers pour generateurs au lithium

    Energy Technology Data Exchange (ETDEWEB)

    Alloin, F.; Sanchez, J.Y. [Laboratoire d`Electrochimie et de Physicochimie des Materiaux et des Interfaces, 38 - Saint-Martin-d`Heres (France)

    1996-12-31

    The use of solvating polymers of polyether type is an interesting solution for the manufacturing of high capacity lithium batteries with lithium metal anodes and which can operate at T > 50 deg. C. These operating conditions are perfectly compatible with electric-powered vehicle and stationary battery applications. In order to improve the ionic conductivity of polymer electrolytes, new aprotic and amorphous polyether lattices have been synthesized having a good conductivity but also good thermal, mechanical and electrochemical stabilities. Two type of 3-D polyether lattices obtained by reticulation of linear pre-polymers have been selected as host polymers: unsaturated poly-condensate and unsaturated co-polyethers. (J.S.) 18 refs.

  19. Polyether matrices for lithium generators; Matrices polyethers pour generateurs au lithium

    Energy Technology Data Exchange (ETDEWEB)

    Alloin, F; Sanchez, J Y [Laboratoire d` Electrochimie et de Physicochimie des Materiaux et des Interfaces, 38 - Saint-Martin-d` Heres (France)

    1997-12-31

    The use of solvating polymers of polyether type is an interesting solution for the manufacturing of high capacity lithium batteries with lithium metal anodes and which can operate at T > 50 deg. C. These operating conditions are perfectly compatible with electric-powered vehicle and stationary battery applications. In order to improve the ionic conductivity of polymer electrolytes, new aprotic and amorphous polyether lattices have been synthesized having a good conductivity but also good thermal, mechanical and electrochemical stabilities. Two type of 3-D polyether lattices obtained by reticulation of linear pre-polymers have been selected as host polymers: unsaturated poly-condensate and unsaturated co-polyethers. (J.S.) 18 refs.

  20. Enhancement of the anticoccidial activity of polyether antibiotics in chickens by tiamulin.

    Science.gov (United States)

    Meingassner, J G; Schmook, F P; Czok, R; Mieth, H

    1979-03-01

    The anticoccidial activities of monensin and lasalocid have been studied separately and in combination with tiamulin, a new pleuromutilin derivative. Combinations of constant tiamulin concentration (.0125%) in drinking water with various levels of polyether anticoccidials (6.3 to 125 ppm) in feed and conversely of constant levels of anticoccidials with various concentrations of tiamulin were used. The prophylactic efficacy of these combined treatments in battery raised broiler chickens infected with Eimeria tenella was evaluated. Assessment of the parameters mortality, weight gain, dropping scores, lesion scores, and oocyst output showed that simultaneous application of tiamulin significantly improved the anticoccidial activity of the polyethers. As tiamulin alone is without anticoccidial activity, this phenomenon was considered to result from an interaction between tiamulin and the polyethers leading to a slower metabolic degradation of the latter. Thus tissue levels adequate for maximum anticoccidial activity would be attained with lower polyether dose levels. Experiments using isolated perfused rat liver showed that elimination of monensin was reduced by 60% in the presence of tiamulin.

  1. Toxicity of pyrolysis gases from polyether sulfone

    Science.gov (United States)

    Hilado, C. J.; Olcomendy, E. M.

    1979-01-01

    A sample of polyether sulfone was evaluated for toxicity of pyrolysis gases, using the toxicity screening test method developed at the University of San Francisco. Animal response times were relatively short at pyrolysis temperatures of 600 to 800 C, with death occurring within 6 min. The principal toxicant appeared to be a compound other than carbon monoxide.

  2. Non-linear Shear and Uniaxial Extensional Rheology of Polyether-Ester-Sulfonate Copolymer Ionomer Melts

    DEFF Research Database (Denmark)

    Shabbir, Aamir; Huang, Qian; P. Baeza, Guilhem

    2017-01-01

    We present unique nonlinear shear and extensional rheology data of unentan-gled amorphous polyester ionomers based on polyethers and sulphonated phthalates with sodium/ lithium counterions. Previous linear viscoelastic (LVE) measurements1 showed significant elasticity in these ionomers due...

  3. Uranium concentrations in fossils measured by SIMS

    International Nuclear Information System (INIS)

    Uyeda, Chiaki; Okano, Jun

    1988-01-01

    Semiquantitative analyses of uranium in fossil bones and teeth were carried out by SIMS. The results show a tendency that uranium concentrations in the fossils increase with the ages of the fossils. It is noticed that fossil bones and teeth having uranium concentration of more than several hundred ppm are not rare. (author)

  4. Measuring Concentration in Data with an Exogenous Order

    OpenAIRE

    Abedieh, Jasmin; Groll, Andreas; Eugster, Manuel J. A.

    2013-01-01

    Concentration measures order the statistical units under observation according to their market share. However, there are situations where an order according to an exogenous variable is more appropriate or even required. The present article introduces a generalized definition of market concentration and defines a corresponding concentration measure. It is shown that this generalized concept of market concentration satisfies the common axioms of (classical) concentration measures. In an appl...

  5. Sequential enzymatic epoxidation involved in polyether lasalocid biosynthesis.

    Science.gov (United States)

    Minami, Atsushi; Shimaya, Mayu; Suzuki, Gaku; Migita, Akira; Shinde, Sandip S; Sato, Kyohei; Watanabe, Kenji; Tamura, Tomohiro; Oguri, Hiroki; Oikawa, Hideaki

    2012-05-02

    Enantioselective epoxidation followed by regioselective epoxide opening reaction are the key processes in construction of the polyether skeleton. Recent genetic analysis of ionophore polyether biosynthetic gene clusters suggested that flavin-containing monooxygenases (FMOs) could be involved in the oxidation steps. In vivo and in vitro analyses of Lsd18, an FMO involved in the biosynthesis of polyether lasalocid, using simple olefin or truncated diene of a putative substrate as substrate mimics demonstrated that enantioselective epoxidation affords natural type mono- or bis-epoxide in a stepwise manner. These findings allow us to figure out enzymatic polyether construction in lasalocid biosynthesis. © 2012 American Chemical Society

  6. [A survey of occupational health among polyether-exposed workers].

    Science.gov (United States)

    Fu, Xu-ying; Yu, Bin; Zhang, Chun-ping; Zheng, Guan-hua; Bai, Lan; Zhang, Pan-pan

    2013-06-01

    To investigate the occupational health of the workers simultaneously exposed to acrylonitrile, epoxyethane, epoxypropane, and styrene. A questionnaire survey was conducted in 70 front-line workers simultaneously exposed to acrylonitrile, epoxyethane, epoxypropane, and styrene (exposure group) and 50 managers (control group) in a polyether manufacturer; in addition, air monitoring at workplace and occupational health examination were also performed. The obtained data were analyzed. The female workers in exposure group and the spouses of male workers in exposure group had significantly higher spontaneous abortion rates than their counterparts in control group (P polyether-exposed working years had significantly higher mean levels of DNA damage than the control group (P polyether-exposed working years and those with not less than 20 polyether-exposed working years had significantly higher mean micronucleus rates than the control group (P polyether-exposed working years (P > 0.05); the workers with not less than 5 and less than 20 polyether-exposed working years and workers with not less than 20 polyether-exposed working years had significantly higher mean micronucleus rates than those with less than 5 polyether-exposed working years (P polyether manufacturer.

  7. Systematic Experimental and Computational Investigation of Ion Transport in Novel Polyether Electrolytes

    Science.gov (United States)

    Pesko, Danielle; Webb, Michael; Jung, Yukyung; Zheng, Qi; Miller, Thomas, III; Coates, Geoffrey; Balsara, Nitash

    Polyethers, such as poly(ethylene oxide) (PEO), are considered to be the most promising polymer electrolyte materials due to their high ionic conductivity and electrochemical stability, both essential for battery applications. To gain a fundamental understanding of the transport properties of polyether systems, we design a systematic set of linear PEO-like polymers to explore the effect of adding carbon spacers to the backbone of the chain. Ac impedance spectroscopy is employed to measure the ionic conductivity of polyether/lithium salt electrolytes; the results elucidate tradeoffs between lowering the glass transition temperature and diluting the polar groups on the polymer chain. Molecular-level insight is provided by molecular dynamics simulations of the polyether electrolytes. We define the useful and intuitive metric of ``connectivity'', a parameter calculated from simulations which describes the physical arrangements of solvation sites in a polymer melt. Direct comparison of experiment and theory allows us to determine the relationship between connectivity and conductivity. The comparison provides insight regarding the factors that control conductivity, and highlights considerations that must be taken when designing new ion-conducting polymers.

  8. Poly-ethers from Winogradskyella poriferorum: Antifouling potential, time-course study of production and natural abundance

    KAUST Repository

    Dash, Swagatika

    2011-08-01

    A sponge-associated bacterium, Winogradskyella poriferorum strain UST030701-295T was cultured up to 100l for extraction of antifouling bioactive compounds. Five poly-ethers were isolated and partially characterized based on nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS); two of them showed inhibitory effects on biofilm formation of marine bacteria and larval settlement of macro-foulers but did not produce any adverse effects on the phenotypes of zebra fish embryos at a concentration of 5μgml -1. The effect of culture duration on the production of the poly-ethers and the bioactivity of the relevant extracts was monitored over a period of 12days. The total crude poly-ether production increased from day 2 to day 5 and the highest bioactivity was observed on day 3. The poly-ethers were found to be localized in the cellular fraction of the extracts, implying their natural occurrence. The potent bioactivity of these poly-ethers together with their high natural abundance in bacteria makes them promising candidates as ingredients in antifouling applications. © 2011 Elsevier Ltd.

  9. 18F fluorination using macrocyclic polyethers

    International Nuclear Information System (INIS)

    Klatte, B.; Knoechel, A.

    The aim of this work is the nucleophilic substitution labelling with 18 F with high selectivity and yield for a short reaction time. Labelling with little or no carrier presumes that 18 F is obtained in anhydrons form. Starting with the production via the nuclear reaction 20 Ne(d,α) 18 F, the 18 F formed is to be continuously converted into an alkali polyether complex whose purpose is to increase the reactivity of the fluoride (compared to the non-complexed anion form), so that nucleophilic substitution reactions can be carried out faster and more carefully. A report is given on the working program and on first results to optimize the carrier-poor synthesis with polyethers as synthesis agent. (RB) [de

  10. Turbidimetry for measurement of radon concentration

    International Nuclear Information System (INIS)

    Wang Huanqiang

    1993-01-01

    This paper describes a turbidimetric technique counting the tracks registered on CR-39 foils exposed to radon. Instead of eyeview through microscope, by using the differential spectrophotometer, strong correlation between the radon cumulative concentration and track turbidence was observed(r=0.999). Under the etching condition of 7.07 mol·L -1 KOH water solution at 80 o C for 16 hr, linear regression showed that the ratio of track turbidence and cumulative concentration of radon exposure was 1.99 x 10 -1 turbidence (KBq m -1 h) -1 and the determination limit was 36 KBq m -3 h. The details of the experiments are represented in this paper. (Author)

  11. Radon concentration measurements in therapeutic spring water

    International Nuclear Information System (INIS)

    Deak, N.; Horvath, A.; Sajo B, L.; Marx, G.

    1996-01-01

    It is believed that people undergoing a curative cycle in a given spa, may receive a dose in the range of 400 mSv/year which is many times the average annual dose so that their risk of lung cancer may increase by 3% or more. To determine the risk due to the natural radioactivity, of the most frequented spas in Budapest (H), we selected four and some others located on the country side being of particular interest. Results of the radon concentration in spring water are presented, with the evidence that some spas have a high radon concentration. We conclude that patients receiving treatment may be exposed to an additional dose in the range of 29-76 mSv/year that at the bronchia could be between 445-1182 mSv/year. (authors). 6 refs., 2 figs., 2 tabs

  12. Dielectric relaxations and conduction mechanisms in polyether-clay composite polymer electrolytes under high carbon dioxide pressure.

    Science.gov (United States)

    Kitajima, Shunsuke; Bertasi, Federico; Vezzù, Keti; Negro, Enrico; Tominaga, Yoichi; Di Noto, Vito

    2013-10-21

    The composite material P(EO/EM)-Sa consisting of synthetic saponite (Sa) dispersed in poly[ethylene oxide-co-2-(2-methoxyethoxy)ethyl glycidyl ether] (P(EO/EM)) is studied by "in situ" measurements using broadband electrical spectroscopy (BES) under pressurized CO2 to characterize the dynamic behavior of conductivity and the dielectric relaxations of the ion host polymer matrix. It is revealed that there are three dielectric relaxation processes associated with: (I) the dipolar motions in the short oxyethylene side chains of P(EO/EM) (β); and (II) the segmental motion of the main chains comprising the polyether components (αfast, αslow). αslow is attributed to the slow α-relaxation of P(EO/EM) macromolecules, which is hindered by the strong coordination interactions with the ions. Two conduction processes are observed, σDC and σID, which are attributed, respectively, to the bulk conductivity and the interdomain conductivity. The temperature dependence of conductivity and relaxation processes reveals that αfast and αslow are strongly correlated with σDC and σID. The "in situ" BES measurements under pressurized CO2 indicate a fast decrease in σDC at the initial CO2 treatment time resulting from the decrease in the concentration of polyether-M(n+) complexes, which is driven by the CO2 permeation. The relaxation frequency (fR) of αslow at the initial CO2 treatment time increases and shows a steep rise with time with the same behavior of the αfast mode. It is demonstrated that the interactions between polyether chains of P(EO/EM) and cations in the polymer electrolyte layers embedded in Sa are probably weakened by the low permittivity of CO2 (ε = 1.08). Thus, the formation of ion pairs in the polymer electrolyte domains of P(EO/EM)-Sa occurs, with a corresponding reduction in the concentration of ion carriers.

  13. Conductivity and properties of polysiloxane-polyether cluster-LiTFSI networks as hybrid polymer electrolytes

    Science.gov (United States)

    Boaretto, Nicola; Joost, Christine; Seyfried, Mona; Vezzù, Keti; Di Noto, Vito

    2016-09-01

    This report describes the synthesis and the properties of a series of polymer electrolytes, composed of a hybrid inorganic-organic matrix doped with LiTFSI. The matrix is based on ring-like oligo-siloxane clusters, bearing pendant, partially cross-linked, polyether chains. The dependency of the thermo-mechanic and of the transport properties on several structural parameters, such as polyether chains' length, cross-linkers' concentration, and salt concentration is studied. Altogether, the materials show good thermo-mechanical and electrochemical stabilities, with conductivities reaching, at best, 8·10-5 S cm-1 at 30 °C. In conclusion, the cell performances of one representative sample are shown. The scope of this report is to analyze the correlations between structure and properties in networked and hybrid polymer electrolytes. This could help the design of optimized polymer electrolytes for application in lithium metal batteries.

  14. Influence of disinfection with peracetic acid and hypochlorite in dimensional alterations of casts obtained from addition silicone and polyether impressions.

    Science.gov (United States)

    Queiroz, Daher Antonio; Peçanha, Marcelo Massaroni; Neves, Ana Christina Claro; Frizzera, Fausto; Tonetto, Mateus Rodrigues; Silva-Concílio, Laís Regiane

    2013-11-01

    Dental impressions disinfection is important to reduce the risk of cross contamination but this process may produce dimensional distortions. Peracetic acid is a disinfectant agent with several favorable characteristics yet underutilized in Dentistry. The aim of this paper is to compare the dimensional stability of casts obtained from addition silicone and polyether impressions that were immersed for 10 minutes in a solution of 0.2% peracetic acid or 1% sodium hypochlorite. Sixty samples in type IV gypsum were produced after a master cast that simulated a full crown preparation of a maxillary premolar. Samples were divided in 6 groups (n = 10) according to the impression material and disinfection agent: Group AC--addition silicone control (without disinfectant); Group APA--addition silicone + 0.2% peracetic acid; Group AH--addition silicone + 1% sodium hypochlorite; Group PC--polyether control (without disinfectant); Group PPA--polyether + 0.2% peracetic acid; Group PH--polyether + 1% sodium hypochlorite. Cast height, base and top diameter were measured and a mean value was obtained for each sample and group all data was statistically analyzed (ANOVA, p polyether impressions regardless of the disinfectant materials. It can be concluded that disinfection with the proposed agents did not produce significant alterations of the impressions and the peracetic acid could be considered a reliable material to disinfect dental molds.

  15. Polyether sulfone membrane modeling and construction for the ...

    African Journals Online (AJOL)

    Polyether sulfone membrane modeling and construction for the removal of nitrate from water using ion interference sulfate and iron nano-particle. ... The aim of this study was constructed the polyether sulfone membrane and modelling it, and for checking impact pressure, the amount of iron nanoparticles and sulfate iron ...

  16. Advances in deuterium dioxide concentration measurement

    Energy Technology Data Exchange (ETDEWEB)

    Shon, Woojung [University of Science & Technology, Daejeon (Korea, Republic of); Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Yim, Sung Paal, E-mail: nspyim@kaeri.re.kr [University of Science & Technology, Daejeon (Korea, Republic of); Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Lim; Park, Hyunmin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Kwang Rag; Chung, Hongsuk [University of Science & Technology, Daejeon (Korea, Republic of); Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Cheo Kyung [Handong Global University, Pohang (Korea, Republic of)

    2016-11-01

    Highlights: • Heavy water (D{sub 2}O) with a high purity level is necessary for nuclear fusion application. • D{sub 2}O purity is analyzed using Fourier Transform infrared (FT-IR) spectroscopy and newly introduced off-axis integrated cavity output spectroscopy (OA-ICOS). • OA-ICOS has advantages in terms of analysis of D{sub 2}O vapor. • OA-ICOS is expected that it can be used for accurate isotopic analyses in the future. - Abstract: The deuterium–tritium (D–T) reaction has been identified as the most efficient reaction for fusion devices. Deuterium can be obtained by heavy water electrolysis. Heavy water (D{sub 2}O) with a high purity level is necessary for nuclear fusion application. A D{sub 2}O isotopic analysis is thus very important. A system for a heavy water analysis was built and a newly designed isotopic analysis experiment was carried out. We tried to analyze the D{sub 2}O purity using Fourier Transform infrared (FT-IR) spectroscopy and newly introduced off-axis integrated cavity output spectroscopy (OA-ICOS). We found that the OA-ICOS based on measurement via laser absorption spectroscopy shows very high sensitivity. We ameliorated the sensitivity by an order of magnitude of more than 10{sup 3}–10{sup 5}. We could make the apparatus smaller by employing very tiny diode laser and fiber optics elements of a DFB (Distributed Feedback) type. Consequently, our device has advantages in terms of maintainability and mobility even in a radioactive environment. This new method could be used for an accurate isotopic analysis in the future.

  17. Lithium-conducting ionic melt electrolytes from polyether-functionalized fluorosulfonimide anions

    International Nuclear Information System (INIS)

    Hallac, B.B.; Geiculescu, O.E.; Rajagopal, R.V.; Creager, S.E.; DesMarteau, D.D.

    2008-01-01

    Solvent-free lithium-conducting ionic melt (IM) electrolytes were synthesized and characterized with respect to chemical structure, purity, and ion transport properties. The melts consist of lithium (perfluorovinylether)sulfonimide salts attached covalently to a lithium-solvating polyether chain. Ionic conductivities are relatively high which is a consequence of the favorable combination of the low lattice energy of the lithium fluorosulfonimide salt (low basicity of the fluorosulfonimide anion), the relatively low viscosity of the polyether matrix, and the relatively high salt content of the melts. Galvanostatic dc polarization experiments, using cells with non-blocking Li electrodes, indicate that salt concentration polarization does not occur in these electrolytes as dc current is passed through them

  18. Surface modification of carbon fibers by a polyether sulfone emulsion sizing for increased interfacial adhesion with polyether sulfone

    International Nuclear Information System (INIS)

    Yuan, Haojie; Zhang, Shouchun; Lu, Chunxiang

    2014-01-01

    Highlights: • A polyether sulfone emulsion (PES) sizing was prepared for the first time. • The sizing enhanced the surface activity and wettability of carbon fibers. • Compared to the original sizing, the PES emulsion sizing resulted in an 18.4% increase in the interlaminar shear strength of carbon fiber/PES composites. • Important influences of emulsifier on the fiber surface and composite interface were demonstrated. • The reinforcing mechanisms are the improved fiber surface wettability and interfacial compatibility in composites. - Abstract: Interests on carbon fiber-reinforced thermoplastic composites are growing rapidly, but the challenges with poor interfacial adhesion have slowed their adoption. In this work, a polyether sulfone (PES) emulsion sizing was prepared successfully for increased interfacial adhesion of carbon fiber/PES composites. To obtain a high-quality PES emulsion sizing, the key factor, emulsifier concentration, was studied by dynamic light scattering technique. The results demonstrated that the suitable weight ratio of PES to emulsifier was 8:3, and the resulting PES emulsion sizing had an average particle diameter of 117 nm and Zeta potential of −52.6 mV. After sizing, the surface oxygen-containing functional groups, free energy and wettability of carbon fibers increased significantly, which were advantageous to promote molecular-level contact between carbon fiber and PES. Finally, short beam shear tests were performed to evaluate the interfacial adhesion of carbon fiber/PES composites. The results indicated that PES emulsion sizing played a critical role for the enhanced interfacial adhesion in carbon fiber/PES composites, and a 26% increase of interlaminar shear strength was achieved, because of the improved fiber surface wettability and interfacial compatibility between carbon fiber and PES

  19. Surface modification of carbon fibers by a polyether sulfone emulsion sizing for increased interfacial adhesion with polyether sulfone

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Haojie [National Engineering Laboratory for Carbon Fiber Technology, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Shouchun, E-mail: zschun@sxicc.ac.cn [National Engineering Laboratory for Carbon Fiber Technology, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China); Lu, Chunxiang [National Engineering Laboratory for Carbon Fiber Technology, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China)

    2014-10-30

    Highlights: • A polyether sulfone emulsion (PES) sizing was prepared for the first time. • The sizing enhanced the surface activity and wettability of carbon fibers. • Compared to the original sizing, the PES emulsion sizing resulted in an 18.4% increase in the interlaminar shear strength of carbon fiber/PES composites. • Important influences of emulsifier on the fiber surface and composite interface were demonstrated. • The reinforcing mechanisms are the improved fiber surface wettability and interfacial compatibility in composites. - Abstract: Interests on carbon fiber-reinforced thermoplastic composites are growing rapidly, but the challenges with poor interfacial adhesion have slowed their adoption. In this work, a polyether sulfone (PES) emulsion sizing was prepared successfully for increased interfacial adhesion of carbon fiber/PES composites. To obtain a high-quality PES emulsion sizing, the key factor, emulsifier concentration, was studied by dynamic light scattering technique. The results demonstrated that the suitable weight ratio of PES to emulsifier was 8:3, and the resulting PES emulsion sizing had an average particle diameter of 117 nm and Zeta potential of −52.6 mV. After sizing, the surface oxygen-containing functional groups, free energy and wettability of carbon fibers increased significantly, which were advantageous to promote molecular-level contact between carbon fiber and PES. Finally, short beam shear tests were performed to evaluate the interfacial adhesion of carbon fiber/PES composites. The results indicated that PES emulsion sizing played a critical role for the enhanced interfacial adhesion in carbon fiber/PES composites, and a 26% increase of interlaminar shear strength was achieved, because of the improved fiber surface wettability and interfacial compatibility between carbon fiber and PES.

  20. Separation of alkali metals by extraction chromatography using polyethers

    International Nuclear Information System (INIS)

    Smulek, W.; Lada, W.

    1977-01-01

    Separation of alkali metals by means of acyclic polyether 1,13 bis(8-chinolinyl)1, 4, 7, 10, 13 pentaoxatridecane (CPOD) and cyclic polyether dibenzo-18-crown-6 (DBC) using extraction chromatography is described. Solutions of NaSCN were used as eluting agents. The separation ability of the polyether columns strongly depends on pH and temperature. The following radioisotopes were used in the experiments: Na-22, K-42, Rb-86 and Cs-137. The radionuclide purity of the tracers was examined by γ-ray spectrometry using a Ge(Li) detector and a multichannel γ-ray spectrometer. (T.I.)

  1. Nondestructive measurement for radionuclide concentration distribution in soil column

    International Nuclear Information System (INIS)

    Ogawa, Hiromichi; Ohnuki, Toshihiko; Yamamoto, Tadatoshi; Wadachi, Yoshiki

    1985-01-01

    A nondestructive method has been studied for determining the concentration of radionuclide (Cs-137) distributed in a soil column. The concentration distribution was calculated from the counting rate distribution using the efficiency matrix of a detector. The concentration distribution obtained by this method, with measuring efficiencies of theoretical calculation, coincides well with that obtained by the destructive sampling method. This method is, therefore, found to be effective for the measurement of one dimensional concentration distribution. The measuring limit of this method is affected not only by the radionuclide concentration but also by the shape of concentration distribution in a soil column and also by the way it is divided into concentration blocks. It is found that, the radioactive concentration up to 2.6 x 10 -4 μCi/g (9.62 Bq/g), and also the distribution up to where the concentration reduces to half at every 1 cm of depth, can be measured by this system. The concentration blocks can be divided into 1 cm of thickness as a minimum value. (author)

  2. Trace Level Determination of Polyether Ionophores in Feed

    Science.gov (United States)

    Rokka, Mervi; Jestoi, Marika; Peltonen, Kimmo

    2013-01-01

    A liquid chromatography-mass spectrometric method was developed and validated to determine six polyether ionophores (lasalocid sodium, monensin sodium, salinomycin sodium, narasin, maduramicin ammonium alpha, and semduramicin sodium) in feed samples. The method developed was very straightforward, involving extraction with 84% acetonitrile of the coccidiostats from the feed samples and filtration of the raw extract prior to chromatographic analysis. Method validation included the determination of selectivity, linearity, specificity, repeatability, the limit of detection, limit of quantification, decision limit (CCα), detection capability (CCβ), and recovery. Feed samples from the Finnish national feed control programme and suspected carry-over samples from a feed manufacturer were analysed in parallel with an existing liquid chromatography method coupled with ultraviolet detection. All feed control samples were negative in LC-UV, but with the developed MS method, monensin, salinomycin, and narasin were detected at concentrations of <0.025–0.73 mg/kg, <0.025–0.027 mg/kg, and <0.025–1.6 mg/kg, respectively. In suspected carry-over samples after an output of 2.0 tonnes of unmedicated feed in the pelletizer line, the concentrations of monensin, salinomycin, and narasin varied from undetected to 16 mg/kg. In the mixer line, after 3.2 tonnes of unmedicated feed output, the concentrations of monensin, salinomycin, and narasin varied from undetected to 2.4 mg/kg. PMID:23484082

  3. Measured and calculated NO2 concentrations in Amsterdam in 2008

    International Nuclear Information System (INIS)

    Wesseling, J.P.; Nguyen, P.L.; Van der Zee, S.

    2010-08-01

    Calculations using the Dutch standard calculation method for air quality in urban streets performed for 38 streets in Amsterdam in 2008 yield, on average, lower Nitrogen dioxide concentrations than measurements at those locations. This follows from research by the RIVM and the Public Health Service of Amsterdam (GGD Amsterdam). The average difference between measured and calculated concentrations is 11 %. At measuring locations of the National Air Quality Measuring Network in the Netherlands no significant underestimation of concentrations by the model is observed. The research was performed by the Dutch ministry of Housing, Spatial Planning en the Environment (VROM). The air quality in the streets that were investigated is mainly determined by emissions from local traffic. The measurements have been performed during thirteen periods of four weeks each, using so called 'Palmes' diffusion tubes. These measurements have been calibrated using the European reference method that is operational in the permanent measuring stations of the GGD Amsterdam. The calculations were performed using the geometry of the roads and information of the traffic at the measuring locations. Part of the differences can be explained, as some locations are not within the scope of the model. In these situations the model is known to perform slightly less. Apart from local traffic, other sources, like shipping, also contribute to the NO2 background concentrations in streets in Amsterdam. Sources that have only globally been included in the calculation of this background concentration may influence concentrations at specific locations. Further studies on this subject will be conducted in 2010. [nl

  4. Structures and properties of naturally occurring polyether antibiotics.

    Science.gov (United States)

    Rutkowski, Jacek; Brzezinski, Bogumil

    2013-01-01

    Polyether ionophores represent a large group of natural, biologically active substances produced by Streptomyces spp. They are lipid soluble and able to transport metal cations across cell membranes. Several of polyether ionophores are widely used as growth promoters in veterinary. Polyether antibiotics show a broad spectrum of bioactivity ranging from antibacterial, antifungal, antiparasitic, antiviral, and tumour cell cytotoxicity. Recently, it has been shown that some of these compounds are able to selectively kill cancer stem cells and multidrug-resistant cancer cells. Thus, they are recognized as new potential anticancer drugs. The biological activity of polyether ionophores is strictly connected with their molecular structure; therefore, the purpose of this paper is to present an overview of their formula, molecular structure, and properties.

  5. Effects of Barium Concentration on Oropharyngeal Swallow Timing Measures

    OpenAIRE

    Stokely, Shauna L.; Molfenter, Sonja M.; Steele, Catriona M.

    2013-01-01

    Videofluoroscopy is commonly used for evaluating oropharyngeal swallowing but requires radiopaque contrast (typically barium). Prior studies suggest that some aspects of swallowing, including timing measures of oral and pharyngeal bolus transit, vary depending on barium concentration. The aim of our study was to identify timing differences in healthy swallowing between “thin” (40 % w/v concentration) and “ultrathin” (22 % w/v concentration) barium solutions. Twenty healthy adults (Ten women; ...

  6. Variation of pH-measurement in platelet concentrates

    NARCIS (Netherlands)

    van der Meer, P. F.; van Zanten, A. P.; Pietersz, R. N.; Reesink, H. W.

    2001-01-01

    To measure pH in platelet concentrates, blood gas analysers with different calibration principles may be used. In this study, variances observed in pH measurements with two types of blood gas analysers were investigated. pH was measured in crystalloid solutions (platelet additive solution (PAS-II),

  7. Preparation of graphite intercalation compounds containing oligo and polyethers

    Science.gov (United States)

    Zhang, Hanyang; Lerner, Michael M.

    2016-02-01

    Layered host-polymer nanocomposites comprising polymeric guests between inorganic sheets have been prepared with many inorganic hosts, but there is limited evidence for the incorporation of polymeric guests into graphite. Here we report for the first time the preparation, and structural and compositional characterization of graphite intercalation compounds (GICs) containing polyether bilayers. The new GICs are obtained by either (1) reductive intercalation of graphite with an alkali metal in the presence of an oligo or polyether and an electrocatalyst, or (2) co-intercalate exchange of an amine for an oligo or polyether in a donor-type GIC. Structural characterization of products using powder X-ray diffraction, Raman spectroscopy, and thermal analyses supports the formation of well-ordered, first-stage GICs containing alkali metal cations and oligo or polyether bilayers between reduced graphene sheets.Layered host-polymer nanocomposites comprising polymeric guests between inorganic sheets have been prepared with many inorganic hosts, but there is limited evidence for the incorporation of polymeric guests into graphite. Here we report for the first time the preparation, and structural and compositional characterization of graphite intercalation compounds (GICs) containing polyether bilayers. The new GICs are obtained by either (1) reductive intercalation of graphite with an alkali metal in the presence of an oligo or polyether and an electrocatalyst, or (2) co-intercalate exchange of an amine for an oligo or polyether in a donor-type GIC. Structural characterization of products using powder X-ray diffraction, Raman spectroscopy, and thermal analyses supports the formation of well-ordered, first-stage GICs containing alkali metal cations and oligo or polyether bilayers between reduced graphene sheets. Electronic supplementary information (ESI) available: Domain size, additional Raman spectra info, compositional calculation, and packing fractions. See DOI: 10.1039/c5

  8. A rare allergy to a polyether dental impression material.

    Science.gov (United States)

    Mittermüller, Pauline; Szeimies, Rolf-Markus; Landthaler, Michael; Schmalz, Gottfried

    2012-08-01

    Polyether impression materials have been used in dentistry for more than 40 years. Allergic reactions to these materials such as reported in the 1970s ceased after replacement of a catalyst. Very recently, however, patients have started to report symptoms that suggest a new allergic reaction from polyether impression materials. Here, we report on the results of allergy testing with polyether impression materials as well as with its components. Eight patients with clinical symptoms of a contact allergy (swelling, redness or blisters) after exposure to a polyether impression material were subjected to patch tests, two of them additionally to a prick test. A further patient with atypical symptoms of an allergy (nausea and vomiting after contact with a polyether impression material in the oral cavity) but with a history of other allergic reaction was also patch tested. The prick tests showed no immediate reactions in the two patients tested. In the patch tests, all eight patients with typical clinical symptoms showed positive reactions to the mixed polyether impression materials, to the base paste or to a base paste component. The patient with the atypical clinical symptoms did not show any positive patch test reactions. Polyether impression materials may evoke type IV allergic reactions. The causative agent was a component of the base paste. In consideration of the widespread use of this impression material (millions of applications per year) and in comparison to the number of adverse reactions from other dental materials, the number of such allergic reactions is very low. In very scarce cases, positive allergic reactions to polyether impression materials are possible.

  9. Effects of barium concentration on oropharyngeal swallow timing measures.

    Science.gov (United States)

    Stokely, Shauna L; Molfenter, Sonja M; Steele, Catriona M

    2014-02-01

    Videofluoroscopy is commonly used for evaluating oropharyngeal swallowing but requires radiopaque contrast (typically barium). Prior studies suggest that some aspects of swallowing, including timing measures of oral and pharyngeal bolus transit, vary depending on barium concentration. The aim of our study was to identify timing differences in healthy swallowing between "thin" (40 % w/v concentration) and "ultrathin" (22 % w/v concentration) barium solutions. Twenty healthy adults (Ten women; mean age = 31 years) each performed a series of three noncued 5-ml swallows each of ultrathin and thin liquid barium solutions in videofluoroscopy. Timing measures were compared between barium concentrations using a mixed-model ANOVA. The measures of interest were stage transition duration, pharyngeal transit time, and duration of upper esophageal sphincter opening. Significant differences were observed in the timing measures of swallowing with respect to barium concentration. In all cases, longer durations were seen with the higher barium concentration. Barium concentration influences timing parameters in healthy swallowing, even between ultrathin and thin concentrations. Clinicians need to understand and control for the impact of different barium stimuli on swallowing physiology.

  10. Aquatic respiration rate measurements at low oxygen concentrations.

    Directory of Open Access Journals (Sweden)

    Moritz Holtappels

    Full Text Available Despite its huge ecological importance, microbial oxygen respiration in pelagic waters is little studied, primarily due to methodological difficulties. Respiration measurements are challenging because of the required high resolution of oxygen concentration measurements. Recent improvements in oxygen sensing techniques bear great potential to overcome these limitations. Here we compare 3 different methods to measure oxygen consumption rates at low oxygen concentrations, utilizing amperometric Clark type sensors (STOX, optical sensors (optodes, and mass spectrometry in combination with (18-18O2 labeling. Oxygen concentrations and consumption rates agreed well between the different methods when applied in the same experimental setting. Oxygen consumption rates between 30 and 400 nmol L(-1 h(-1 were measured with high precision and relative standard errors of less than 3%. Rate detection limits in the range of 1 nmol L(-1 h(-1 were suitable for rate determinations in open ocean water and were lowest at the lowest applied O2 concentration.

  11. Measurement of radon activity concentrations in air of Tuzla city

    International Nuclear Information System (INIS)

    Adrovic, F.; Fazlic, R.; Tresnjo, Z.

    2004-01-01

    The survey was conducted over one year in the area of Tuzla city and its surrounding. At the measuring locations there were registered Daily and seasonal variations in outdoor radon concentration were observed, with average values lying within the region of 9 - 30 Bq/m 3 . The results of the measurements will be included in the concentration map of radon activity in Bosnia and Herzegovina, which is under preparation. (P.A.)

  12. UV-Surface Treatment of Fungal Resistant Polyether Polyurethane Film-Induced Growth of Entomopathogenic Fungi.

    Science.gov (United States)

    Lando, Gabriela Albara; Marconatto, Letícia; Kessler, Felipe; Lopes, William; Schrank, Augusto; Vainstein, Marilene Henning; Weibel, Daniel Eduardo

    2017-07-18

    Synthetic polymers are the cause of some major environmental impacts due to their low degradation rates. Polyurethanes (PU) are widely used synthetic polymers, and their growing use in industry has produced an increase in plastic waste. A commercial polyether-based thermoplastic PU with hydrolytic stability and fungus resistance was only attacked by an entomopathogenic fungus, Metarhiziumanisopliae , when the films were pre-treated with Ultraviolet (UV) irradiation in the presence of reactive atmospheres. Water contact angle, Fourier transform infrared spectroscopy in attenuated total reflection mode (FTIR-ATR), scanning electron microscopy (SEM), and profilometer measurements were mainly used for analysis. Permanent hydrophilic PU films were produced by the UV-assisted treatments. Pristine polyether PU films incubated for 10, 30, and 60 days did not show any indication of fungal growth. On the contrary, when using oxygen in the UV pre-treatment a layer of fungi spores covered the sample, indicating a great adherence of the microorganisms to the polymer. However, if acrylic acid vapors were used during the UV pre-treatment, a visible attack by the entomopathogenic fungi was observed. SEM and FTIR-ATR data showed clear evidence of fungal development: growth and ramifications of hyphae on the polymer surface with the increase in UV pre-treatment time and fungus incubation time. The results indicated that the simple UV surface activation process has proven to be a promising alternative for polyether PU waste management.

  13. UV-Surface Treatment of Fungal Resistant Polyether Polyurethane Film-Induced Growth of Entomopathogenic Fungi

    Directory of Open Access Journals (Sweden)

    Gabriela Albara Lando

    2017-07-01

    Full Text Available Synthetic polymers are the cause of some major environmental impacts due to their low degradation rates. Polyurethanes (PU are widely used synthetic polymers, and their growing use in industry has produced an increase in plastic waste. A commercial polyether-based thermoplastic PU with hydrolytic stability and fungus resistance was only attacked by an entomopathogenic fungus, Metarhiziumanisopliae, when the films were pre-treated with Ultraviolet (UV irradiation in the presence of reactive atmospheres. Water contact angle, Fourier transform infrared spectroscopy in attenuated total reflection mode (FTIR-ATR, scanning electron microscopy (SEM, and profilometer measurements were mainly used for analysis. Permanent hydrophilic PU films were produced by the UV-assisted treatments. Pristine polyether PU films incubated for 10, 30, and 60 days did not show any indication of fungal growth. On the contrary, when using oxygen in the UV pre-treatment a layer of fungi spores covered the sample, indicating a great adherence of the microorganisms to the polymer. However, if acrylic acid vapors were used during the UV pre-treatment, a visible attack by the entomopathogenic fungi was observed. SEM and FTIR-ATR data showed clear evidence of fungal development: growth and ramifications of hyphae on the polymer surface with the increase in UV pre-treatment time and fungus incubation time. The results indicated that the simple UV surface activation process has proven to be a promising alternative for polyether PU waste management.

  14. Study of distillation and degradation of perfluoro polyether

    International Nuclear Information System (INIS)

    Lopergolo, Lilian Cristine

    1997-01-01

    Perfluoro-polyethers, PFPE, were first synthesised by Sianesi and collaborators giving rise to a new lubricant oils and greases classes with several applications. Perfluoro polyethers have excellent properties, for instance: high chemical stability and thermal stability, high density, high radiation resistance and excellent lubricating properties. FOMBLIN-Y oil is one of the perfluoro polyethers used as a lubricant in vacuum systems applied in the UF 6 enrichment installations. Due to its excellent properties and for its applications in the nuclear field, IPEN-CNEN/S P had the interest to dominate its production technology with the aim to substitute the commercial FOMBLIN-Y oil used in the national consumption. The FOMBLIN-Y oil synthesis method, adopted in IPEN-CNEN/S P, made by the photooxidation of the hexa fluoro propylene. In this work we study the fraction separation of the national available production with restricted an increased molecular weights which was obtained by fraction distillation in a vacuum according to the ASTM D-1160 norm. We also study the catalytic effect of metals on the thermal stability of perfluoro polyethers. The inertness of perfluoro polyethers at temperatures higher than 300 deg C is strongly affected by presence of some metals. Al and Ti alloys cause fluid degradation at 250 deg C. This degradation is very important because it has a yield increase of the perfluoro polyethers production. (author)

  15. 18-Crown-6-polyether complexing with iodine

    International Nuclear Information System (INIS)

    Borovikov, Yu.Ya.

    1988-01-01

    Using the methods of dielectrometry, conductometry, calorimetry, UV, NMR and IR spectroscopy, 18-Crown-6-polyether complexing with iodine in chlorobenzene, benzotrifluoride, 1,2 dichloroethane is investigated. At the first stage external complexes (1) of the composition 1:1 (dipole momentum μ=7 D) is formed, which gradually regroups into internal complex (2) of the compositon 4:1. The time of 1 transition into 2 is inversely proportional to dielectric permeability of the medium. Enthalpy of 1 formation is close to 8.3 kcal/mol, which is 2,5 times higher than in cyclohexane solutions. Complex 1 is molecular, 2 is salt-like. Formation enthalpy of complex 2 of the components is not high, in dichlaroethane it is centrally symmetric and nonpolar, in chlorobenzene and benzotrifluoride-highly polar. In solid phase complex of the composition 1:2 is formed

  16. 18-Crown-6-polyether complexing with iodine

    Energy Technology Data Exchange (ETDEWEB)

    Borovikov, Yu Ya [AN Ukrainskoj SSR, Kiev (Ukrainian SSR). Inst. Organicheskoj Khimii

    1988-01-01

    Using the methods of dielectrometry, conductometry, calorimetry, UV, NMR and IR spectroscopy, 18-Crown-6-polyether complexing with iodine in chlorobenzene, benzotrifluoride, 1,2 dichloroethane is investigated. At the first stage external complexes (1) of the composition 1:1 (dipole momentum {mu}=7 D) is formed, which gradually regroups into internal complex (2) of the compositon 4:1. The time of 1 transition into 2 is inversely proportional to dielectric permeability of the medium. Enthalpy of 1 formation is close to 8.3 kcal/mol, which is 2,5 times higher than in cyclohexane solutions. Complex 1 is molecular, 2 is salt-like. Formation enthalpy of complex 2 of the components is not high, in dichlaroethane it is centrally symmetric and nonpolar, in chlorobenzene and benzotrifluoride-highly polar. In solid phase complex of the composition 1:2 is formed.

  17. Measurements of indoor radon concentration in Libyan cities

    International Nuclear Information System (INIS)

    Elarabiy, S. F.; Khalifa, M.; Misrati, N.; Chahboune, N.; Ahmed, M.

    2012-12-01

    Studies confirm that the risk of exposure to indor radon is attributable to lung cancer worldwide. The relationship between radon exposure and cancer is a linear one which necessitates for need for measurements of indoor radon concentration. This paper presents the results of measurements of indoor radon in several libya cities using CR-39 plastic. The results showed that the average radon concentration in the cities of Tripoli, Al-harcha and Alrajaban were 48.8 Bg/m 3 , 51.4 Bg/m 3 and 55.5 Bg/m 3 respectively. The average indoor radon concentration in Libya is low comparing with other studies. (Author)

  18. Workplace aerosol mass concentration measurement using optical particle counters.

    Science.gov (United States)

    Görner, Peter; Simon, Xavier; Bémer, Denis; Lidén, Göran

    2012-02-01

    Direct-reading aerosol measurement usually uses the optical properties of airborne particles to detect and measure particle concentration. In the case of occupational hygiene, mass concentration measurement is often required. Two aerosol monitoring methods are based on the principle of light scattering: optical particle counting (OPC) and photometry. The former analyses the light scattered by a single particle, the latter by a cloud of particles. Both methods need calibration to transform the quantity of scattered light detected into particle concentration. Photometers are simpler to use and can be directly calibrated to measure mass concentration. However, their response varies not only with aerosol concentration but also with particle size distribution, which frequently contributes to biased measurement. Optical particle counters directly measure the particle number concentration and particle size that allows assessment of the particle mass provided the particles are spherical and of known density. An integrating algorithm is used to calculate the mass concentration of any conventional health-related aerosol fraction. The concentrations calculated thus have been compared with simultaneous measurements by conventional gravimetric sampling to check the possibility of field OPC calibration with real workplace aerosols with a view to further monitoring particle mass concentration. Aerosol concentrations were measured in the food industry using the OPC GRIMM® 1.108 and the CIP 10-Inhalable and CIP 10-Respirable (ARELCO®) aerosol samplers while meat sausages were being brushed and coated with calcium carbonate. Previously, the original OPC inlet had been adapted to sample inhalable aerosol. A mixed aerosol of calcium carbonate and fungi spores was present in the workplace. The OPC particle-size distribution and an estimated average particle density of both aerosol components were used to calculate the mass concentration. The inhalable and respirable aerosol fractions

  19. Validation of image cytometry for sperm concentration measurement

    DEFF Research Database (Denmark)

    Egeberg Palme, Dorte L.; Johannsen, Trine Holm; Petersen, Jørgen Holm

    2017-01-01

    Sperm concentration is an essential parameter in the diagnostic evaluation of men from infertile couples. It is usually determined by manual counting using a hemocytometer, and is therefore both laborious and subjective. We have earlier shown that a newly developed image cytometry (IC) method may...... be used to determine sperm concentration. Here we present a validation of the IC method by analysis of 4010 semen samples. There was high agreement between IC and manual counting at sperm concentrations above 3 mill/ml and in samples with concentrations above 12 mill/ml the two methods can be used...... a lower coefficient of variation than the manual method (5% vs 10%), indicating a better precision of the IC method. In conclusion, measurement of sperm concentration by IC can be used at concentrations above 3 mill/ml and seems more accurate and precise than manual counting, making it an attractive...

  20. Traceable measurements of the activity concentration in air

    CERN Document Server

    Paul, A; Forkel-Wirth, Doris; Müller, A; Marcos, A

    2002-01-01

    The nuclear reactions induced by high energetic protons in heavy targets such as UC/sub 2/ and ThC cause a particular, complex radiation protection task at facilities like ISOLDE: the measurement of a mixture of different isotopes of the radioactive noble gas radon and the radon progenies in air. The knowledge of their respective activity concentration is fundamental for exposure assessments. Due to the complex mixture of activity concentrations in air, its precise determination is quite difficult. Therefore, a new procedure for taking reference samples was developed and implemented for the traceable measurement of the activity concentration of radioactive ions (e.g., radon progenies) in air. This technique is combined by measuring alpha -particles with a multi-wire ionization chamber for the parallel on-line determination of the activity concentration of different radon isotopes. (10 refs).

  1. Intercomparison of different instruments for measuring radon concentration in air

    International Nuclear Information System (INIS)

    Shimo, Michikuni; Iida, Takao

    1990-01-01

    An intercomparison of different instruments for measurement of radon concentration was carried out. The instruments include an ionization chamber, the charcoal-trap method, a flow-type ionization chamber (pulse-counting method), a two-filter method, an electrostatic collection method and a passive integration radon monitor. All instruments except for the passive radon monitor have been calibrated independently. Measurements were performed over a concentration range from about 3.5 Bq·m -3 (in outdoor air) to 110 Bq·m -3 (in indoor air). The results obtained by these techniques, except the two-filter technique, are comparable. Radon daughter concentration measured using a filter-sampling method was about 52% of radon concentration. (author)

  2. Intercomparison of different instruments that measure radon concentration in air

    International Nuclear Information System (INIS)

    Shimo, M.; Iida, T.; Ikebe, Y.

    1987-01-01

    An intercomparison of different instruments for measurement of radon concentration was carried out. The instruments include an ionization chamber, the charcoal-trap technique, a flow-type ionization chamber (pulse-counting technique), a two-filter method, an electrostatic collection method and a passive integrating radon monitor. All instruments except for the passive radon monitor have been calibrated independently. Measurements were performed over a concentration range from about 3.5 Bq/m/sup 3/ (in outdoor air) to 110 Bq/m/sup 3/ (in indoor air). The results obtained from these techniques, except the two-filter technique, are comparable. Radon daughter concentration measured using a filter-sampling technique was about 52% of radon concentrations

  3. Traceable measurements of the activity concentration in air

    International Nuclear Information System (INIS)

    Paul, Annette; Honig, Anja; Forkel-Wirth, Doris; Mueller, Andre; Marcos, Alicia

    2002-01-01

    The nuclear reactions induced by high energetic protons in heavy targets such as UC 2 and ThC cause a particular, complex radiation protection task at facilities like ISOLDE: the measurement of a mixture of different isotopes of the radioactive noble gas radon and the radon progenies in air. The knowledge of their respective activity concentration is fundamental for exposure assessments. Due to the complex mixture of activity concentrations in air, its precise determination is quite difficult. Therefore, a new procedure for taking reference samples was developed and implemented for the traceable measurement of the activity concentration of radioactive ions (e.g., radon progenies) in air. This technique is combined by measuring α-particles with a multi-wire ionization chamber for the parallel on-line determination of the activity concentration of different radon isotopes

  4. Reflective measurement of water concentration using millimeter wave illumination

    Science.gov (United States)

    Sung, Shijun; Bennett, David; Taylor, Zachary; Bajwa, Neha; Tewari, Priyamvada; Maccabi, Ashkan; Culjat, Martin; Singh, Rahul; Grundfest, Warren

    2011-04-01

    THz and millimeter wave technology have shown the potential to become a valuable medical imaging tool because of its sensitivity to water and safe, non-ionizing photon energy. Using the high dielectric constant of water in these frequency bands, reflectionmode THz sensing systems can be employed to measure water content in a target with high sensitivity. This phenomenology may lead to the development of clinical systems to measure the hydration state of biological targets. Such measurements may be useful in fast and convenient diagnosis of conditions whose symptoms can be characterized by changes in water concentration such as skin burns, dehydration, or chemical exposure. To explore millimeter wave sensitivity to hydration, a reflectometry system is constructed to make water concentration measurements at 100 GHz, and the minimum detectable water concentration difference is measured. This system employs a 100 GHz Gunn diode source and Golay cell detector to perform point reflectivity measurements of a wetted polypropylene towel as it dries on a mass balance. A noise limited, minimum detectable concentration difference of less than 0.5% by mass can be detected in water concentrations ranging from 70% to 80%. This sensitivity is sufficient to detect hydration changes caused by many diseases and pathologies and may be useful in the future as a diagnostic tool for the assessment of burns and other surface pathologies.

  5. Concentration of Radon Progeny in Air by Alpha Spectrometry Measurement

    International Nuclear Information System (INIS)

    Acena, M. L.; Crespo, M. T.

    1989-01-01

    The concentration of radon progeny in air has been determined by alpha spectrometry measurement of 214 Po and 318 Po. A known volume of air was passed through a filter, then the alpha activity was directly measured on this filter. (Author) 15 refs

  6. Comparison of predicted and measured variations of indoor radon concentration

    International Nuclear Information System (INIS)

    Arvela, H.; Voutilainen, A.; Maekelaeinen, I.; Castren, O.; Winqvist, K.

    1988-01-01

    Prediction of the variations of indoor radon concentration were calculated using a model relating indoor radon concentration to radon entry rate, air infiltration and meteorological factors. These calculated variations have been compared with seasonal variations of 33 houses during 1-4 years, with winter-summer concentration ratios of 300 houses and the measured diurnal variation. In houses with a slab in ground contact the measured seasonal variations are quite often in agreement with variations predicted for nearly pure pressure difference driven flow. The contribution of a diffusion source is significant in houses with large porous concrete walls against the ground. Air flow due to seasonally variable thermal convection within eskers strongly affects the seasonal variations within houses located thereon. Measured and predicted winter-summer concentration ratios demonstrate that, on average, the ratio is a function of radon concentration. The ratio increases with increasing winter concentration. According to the model the diurnal maximum caused by a pressure difference driven flow occurs in the morning, a finding which is in agreement with the measurements. The model presented can be used for differentiating between factors affecting radon entry into houses. (author)

  7. Comparative study to evaluate the accuracy of polyether occlusal bite registration material and occlusal registration wax as a guide for occlusal reduction during tooth preparation

    Directory of Open Access Journals (Sweden)

    Niranjan Joshi

    2013-01-01

    Objective: The objective of this study was to compare and evaluate the reliability of the most commonly used occlusal registration wax that with polyether bite registration material as a guide for occlusal reduction required during tooth preparations. Materials and Methods: For the purpose of this study, 25 abutment teeth requiring tooth preparation for fixed prosthesis were selected and tooth preparations carried out. Modeling wax strips of specific dimensions were placed onto the cast of prepared tooth, which was mounted on maximum intercuspation on the articulator and the articulator was closed. The thickness of the wax registration was measured at three zones namely two functional cusps and central fossa. Similar measurements were made using the polyether bite registration material and prosthesis at the same zones. The data was tabulated and was subjected to statistical analysis using anova test and Tukey honestly significant difference test. Results: The differences in thickness between wax record and prosthesis by 0.1346 mm, whereas the difference between polyether and prosthesis was 0.02 mm with a P value of 0.042, which is statistically significant. This means that the wax record was 8.25% larger than the prosthesis while polyether was just 1.27% larger than the prosthesis. Conclusion: The clinical significance of the above analysis is that Ramitec polyether bite registration material is most suitable material when compared with commonly used modeling wax during the tooth preparation.

  8. Partially fluorinated aarylene polyethers and their ternary blends with PBI and H3PO4

    DEFF Research Database (Denmark)

    Li, Qingfeng; Jensen, Jens Oluf; Pan, Chao

    2008-01-01

    Ternary blend membranes based on sulphonated partially fluorinated arylene polyether, polybenzimidazole (PBI) and phosphoric acid were prepared and characterised as electrolyte for high temperature proton exchange membrane fuel cells. Partially fluorinated arylene polyether was first prepared from...

  9. Novel amide polar-embedded reversed-phase column for the fast liquid chromatography-tandem mass spectrometry method to determine polyether ionophores in environmental waters.

    Science.gov (United States)

    Herrero, P; Borrull, F; Pocurull, E; Marcé, R M

    2012-11-09

    A fast chromatographic method has been developed that takes less than 5 min per run to determine five polyether ionophores with a novel amide polar-embedded reversed-phase column coupled to a triple quadrupole mass spectrometer. A comparison between Oasis HLB and Oasis MAX sorbents for the solid-phase extraction was done. Oasis HLB sorbent gave recoveries close to 90% and the repeatability (%RSD, 25-100 ng/L, n=3) of the method was less than 7% for all compounds in all matrices. The presence of polyether ionophores in environmental waters such as river water and sewage was investigated. Monensin and narasin were frequently determined in influent and effluent sewage at concentrations from 10 ng/L to 47 ng/L in influents and from 6 ng/L to 34 ng/L in effluents. In river waters, polyether ionophores were not detected in any sample. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Comparing predicted estrogen concentrations with measurements in US waters

    International Nuclear Information System (INIS)

    Kostich, Mitch; Flick, Robert; Martinson, John

    2013-01-01

    The range of exposure rates to the steroidal estrogens estrone (E1), beta-estradiol (E2), estriol (E3), and ethinyl estradiol (EE2) in the aquatic environment was investigated by modeling estrogen introduction via municipal wastewater from sewage plants across the US. Model predictions were compared to published measured concentrations. Predictions were congruent with most of the measurements, but a few measurements of E2 and EE2 exceed those that would be expected from the model, despite very conservative model assumptions of no degradation or in-stream dilution. Although some extreme measurements for EE2 may reflect analytical artifacts, remaining data suggest concentrations of E2 and EE2 may reach twice the 99th percentile predicted from the model. The model and bulk of the measurement data both suggest that cumulative exposure rates to humans are consistently low relative to effect levels, but also suggest that fish exposures to E1, E2, and EE2 sometimes substantially exceed chronic no-effect levels. -- Highlights: •Conservatively modeled steroidal estrogen concentrations in ambient water. •Found reasonable agreement between model and published measurements. •Model and measurements agree that risks to humans are remote. •Model and measurements agree significant questions remain about risk to fish. •Need better understanding of temporal variations and their impact on fish. -- Our model and published measurements for estrogens suggest aquatic exposure rates for humans are below potential effect levels, but fish exposure sometimes exceeds published no-effect levels

  11. The active titration method for measuring local hydroxyl radical concentration

    Science.gov (United States)

    Sprengnether, Michele; Prinn, Ronald G.

    1994-01-01

    We are developing a method for measuring ambient OH by monitoring its rate of reaction with a chemical species. Our technique involves the local, instantaneous release of a mixture of saturated cyclic hydrocarbons (titrants) and perfluorocarbons (dispersants). These species must not normally be present in ambient air above the part per trillion concentration. We then track the mixture downwind using a real-time portable ECD tracer instrument. We collect air samples in canisters every few minutes for roughly one hour. We then return to the laboratory and analyze our air samples to determine the ratios of the titrant to dispersant concentrations. The trends in these ratios give us the ambient OH concentration from the relation: dlnR/dt = -k(OH). A successful measurement of OH requires that the trends in these ratios be measureable. We must not perturb ambient OH concentrations. The titrant to dispersant ratio must be spatially invariant. Finally, heterogeneous reactions of our titrant and dispersant species must be negligible relative to the titrant reaction with OH. We have conducted laboratory studies of our ability to measure the titrant to dispersant ratios as a function of concentration down to the few part per trillion concentration. We have subsequently used these results in a gaussian puff model to estimate our expected uncertainty in a field measurement of OH. Our results indicate that under a range of atmospheric conditions we expect to be able to measure OH with a sensitivity of 3x10(exp 5) cm(exp -3). In our most optimistic scenarios, we obtain a sensitivity of 1x10(exp 5) cm(exp -3). These sensitivity values reflect our anticipated ability to measure the ratio trends. However, because we are also using a rate constant to obtain our (OH) from this ratio trend, our accuracy cannot be better than that of the rate constant, which we expect to be about 20 percent.

  12. Continuous measurement of uranium concentrations with the laser spark

    International Nuclear Information System (INIS)

    Gutmacher, R.G.; Cremers, D.A.; Wachter, J.R.

    1987-01-01

    Laser-induced breakdown spectroscopy has been applied to the continuous determination of uranium concentrations between 0.1 and 300 g/L in flowing solutions. The technique is rapid, noninvasive, and unaffected by radioactivity. A concentration of 10 g/L was measured with 0.8% precision in 3 min. Substances that absorb at the laser wavelength, suspended materials, and variations in the acidity of the solution have little or no effect on the results. High concentrations of zirconium, cadmium, aluminum, or stainless steel in solution do not interfere

  13. Measurements in Concentrated Sun using a Remote Controlled Robot

    Directory of Open Access Journals (Sweden)

    Dan Floroian

    2013-04-01

    Full Text Available Nowdays, using the concentrated sunlight is a big issue because the amount of energy is very high and the light is concentrated in a very small area. The main problem in this situation is the heating, and in order to make safe measurements a remote controlled robot is needed. After that, a remote controlled robot will assume the duty of protect the measured sample and to expose it for a precise time to the concentrated sun in order to reduce heating of the sample. For easy operating, and for automatize the process, all the duties, starting with initial conditions, continuing with triggering the measurements, and conditioning the signals and finalizing with data saving must be assured by the robot.

  14. Measurement of average radon gas concentration at workplaces

    International Nuclear Information System (INIS)

    Kavasi, N.; Somlai, J.; Kovacs, T.; Gorjanacz, Z.; Nemeth, Cs.; Szabo, T.; Varhegyi, A.; Hakl, J.

    2003-01-01

    In this paper results of measurement of average radon gas concentration at workplaces (the schools and kindergartens and the ventilated workplaces) are presented. t can be stated that the one month long measurements means very high variation (as it is obvious in the cases of the hospital cave and the uranium tailing pond). Consequently, in workplaces where the expectable changes of radon concentration considerable with the seasons should be measure for 12 months long. If it is not possible, the chosen six months period should contain summer and winter months as well. The average radon concentration during working hours can be differ considerable from the average of the whole time in the cases of frequent opening the doors and windows or using artificial ventilation. (authors)

  15. TXRF 'measurements' of concentration distribution below the detection limit

    International Nuclear Information System (INIS)

    Kubala-Kukus, A.; Banas, D.; Braziewicz, J.; Majewska, U.; Mrowczynski, S.; Pajek, M.

    2000-01-01

    We demonstrate that a shape of the concentration distribution of the element in a set of samples, as measured by the TXRF method, can be determined even for the concentrations below the detection limit (DL). This can be done, when the measurements reporting the concentration below DL level are included properly in the analysis of the results. The method developed for such correction is presented and discussed. It is demonstrated that this correction is particularly important when the studied concentrations are close to the DL level of the method, which is a common case for TXRF. In the paper a precision of the developed correction is discussed in details, by using the results of numerical simulations of experiments for different concentration distributions and number of performed measurements. It is demonstrated that the factor, which limits the accuracy of the correction, is the number of measurements, not the correction procedure itself. The applicability and importance of the developed correction is demonstrated for routine TXRF analysis of different types of samples of bio-medical interest. (author)

  16. QA/QC For Radon Concentration Measurement With Charcoal Canister

    International Nuclear Information System (INIS)

    Pantelic, G.; Zivanovic, M.; Rajacic, M.; Krneta Nikolic, J.; Todorovic, D.

    2015-01-01

    The primary concern of any measuring of radon or radon progeny must be the quality of the results. A good quality assurance program, when properly designed and diligently followed, ensures that laboratory staff will be able to produce the type and quality of measurement results which is needed and expected. Active charcoal detectors are used for testing the concentration of radon in dwellings. The method of measurement is based on radon adsorption on coal and measurement of gamma radiation of radon daughters. Upon closing the detectors, the measurement was carried out after achieving the equilibrium between radon and its daughters (at least 3 hours) using NaI or HPGe detector. Radon concentrations as well as measurement uncertainties were calculated according to US EPA protocol 520/5-87-005. Detectors used for the measurements were calibrated by 226Ra standard of known activity in the same geometry. Standard and background canisters are used for QA and QC, as well as for the calibration of the measurement equipment. Standard canister is a sealed canister with the same matrix and geometry as the canisters used for measurements, but with the known activity of radon. Background canister is a regular radon measurement canister, which has never been exposed. The detector background and detector efficiency are measured to ascertain whether they are within the warning and acceptance limits. (author).

  17. Fissile materials in solution concentration measured by active neutron interrogation

    International Nuclear Information System (INIS)

    Romeyer Dherbey, J.; Passard, Ch.; Cloue, J.; Bignan, G.

    1993-01-01

    The use of the active neutron interrogation to measure the concentration of plutonium contained in flow solutions is particularly interesting for fuel reprocessing plants. Indeed, this method gives a signal which is in a direct relation with the fissile materials concentration. Moreover, it is less sensitive to the gamma dose rate than the other nondestructive methods. Two measure methods have been evolved in CEA. Their principles are given into details in this work. The first one consists to detect fission delayed neutrons induced by a 252 Cf source. In the second one fission prompt neutrons induced by a neutron generator of 14 MeV are detected. (O.M.)

  18. 40 CFR Table 4 to Subpart Ppp of... - Known Organic HAP From Polyether Polyol Products

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Known Organic HAP From Polyether Polyol... CATEGORIES National Emission Standards for Hazardous Air Pollutant Emissions for Polyether Polyols Production Pt. 63, Subpt. PPP, Table 4 Table 4 to Subpart PPP of Part 63—Known Organic HAP From Polyether Polyol...

  19. Measurement of radon concentration in water with Lucas cell detector

    International Nuclear Information System (INIS)

    Machaj, B.; Pienkos, J.P.

    2003-01-01

    A method for the measurement of radon concentration in water is presented based on flushing a water sample with air in a closed loop with the Lucas cell as alpha radiation detector. The main feature of the method is washing radon away from the larger sample of water (0.75 l) to a small volume of air, approximately 0.5 l, thanks to which a high radon concentration in air and a considerable sensitivity of measurement is achieved. Basic relations and results of measurements of a model of a gauge is given. The estimated measuring sensitivity (S) is 8.5 (cpm)/(Bq/l). The random error due to the statistical fluctuations of count rate at radon concentrations 1,10, 100, 1000, 10000 Bq/l is 11, 3.6, 1.1, 0.4, 0.1% correspondingly at a counting (measuring) time of 10 min. The minimum detectable radon concentration in water is 0.11 Bq/l. (author)

  20. Surface modification of carbon fibers by a polyether sulfone emulsion sizing for increased interfacial adhesion with polyether sulfone

    Science.gov (United States)

    Yuan, Haojie; Zhang, Shouchun; Lu, Chunxiang

    2014-10-01

    Interests on carbon fiber-reinforced thermoplastic composites are growing rapidly, but the challenges with poor interfacial adhesion have slowed their adoption. In this work, a polyether sulfone (PES) emulsion sizing was prepared successfully for increased interfacial adhesion of carbon fiber/PES composites. To obtain a high-quality PES emulsion sizing, the key factor, emulsifier concentration, was studied by dynamic light scattering technique. The results demonstrated that the suitable weight ratio of PES to emulsifier was 8:3, and the resulting PES emulsion sizing had an average particle diameter of 117 nm and Zeta potential of -52.6 mV. After sizing, the surface oxygen-containing functional groups, free energy and wettability of carbon fibers increased significantly, which were advantageous to promote molecular-level contact between carbon fiber and PES. Finally, short beam shear tests were performed to evaluate the interfacial adhesion of carbon fiber/PES composites. The results indicated that PES emulsion sizing played a critical role for the enhanced interfacial adhesion in carbon fiber/PES composites, and a 26% increase of interlaminar shear strength was achieved, because of the improved fiber surface wettability and interfacial compatibility between carbon fiber and PES.

  1. SORPTION OF Ga (III ON FLEXIBLE OPEN CELL POLYURETHANE FOAM OF POLYETHER TYPE IMPREGNATED WITH TRI-N-BUTHYL PHOSPATE

    Directory of Open Access Journals (Sweden)

    Lavinia Tofan

    2007-06-01

    Full Text Available The obtained results concerning the Ga (III ion retention on flexible open cell polyurethane foam of polyether type pretreated with tri-n-butyl phosphate are presented. The influence of solution acidity, phases contact time, Ga (III concentration and solution temperature have been investigated. The parameters of Ga (III batch sorption have been optimized. On the basis of Langmuir isotherms, the sorption constants and the thermodynamic parameters, ∆G, ∆Η and ∆S have been calculated.

  2. Measurement of plasma homovanillic acid concentrations in schizophrenic patients.

    Science.gov (United States)

    Kaminski, R; Powchick, P; Warne, P A; Goldstein, M; McQueeney, R T; Davidson, M

    1990-01-01

    1. Several lines of evidence suggest that abnormalities of central dopaminergic transmission may be involved in the expression of some schizophrenic symptoms. However, elucidation of the role of dopamine (DA) in schizophrenia has eluded investigative efforts partially because no accurate and easily repeatable measure of brain DA activity exists. 2. The development of a technique to measure homovanillic acid in plasma has offered the possibility of performing serial measurements of this major DA metabolite. 3. Assuming that plasma homovanillic acid (PHVA) concentrations is an index of brain DA activity, measurement of PHVA can play a role in elucidating the DA abnormality in schizophrenia. 4. Results to date suggest that plasma homovanillic acid concentrations are lower in chronic schizophrenic patients compared to normal controls, and that PHVA values correlate with schizophrenic symptom severity. 5. In addition, PHVA levels were shown to initially rise and subsequently decline during chronic neuroleptic administration in treatment responsive but not in treatment refractory schizophrenic patients.

  3. Polyether ionophores-promising bioactive molecules for cancer therapy.

    Science.gov (United States)

    Huczyński, Adam

    2012-12-01

    The natural polyether ionophore antibiotics might be important chemotherapeutic agents for the treatment of cancer. In this article, the pharmacology and anticancer activity of the polyether ionophores undergoing pre-clinical evaluation are reviewed. Most of polyether ionophores have shown potent activity against the proliferation of various cancer cells, including those that display multidrug resistance (MDR) and cancer stem cells (CSC). The mechanism underlying the anticancer activity of ionophore agents can be related to their ability to form complexes with metal cations and transport them across cellular and subcellular membranes. Increasing evidence shows that the anticancer activity of polyether ionophores may be a consequence of the induction of apoptosis leading to apoptotic cell death, arresting cell cycle progression, induction of the cell oxidative stress, loss of mitochondrial membrane potential, reversion of MDR, synergistic anticancer effect with other anticancer drugs, etc. Continued investigation of the mechanisms of action and development of new polyether ionophores and their derivatives may provide more effective therapeutic drugs for cancer treatments. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Fiber Optic Displacement Sensor for Measuring Cholesterol Concentration

    Directory of Open Access Journals (Sweden)

    Moh. Budiyanto

    2017-11-01

    Full Text Available A simple design of a cholesterol concentration detection is proposed and demonstrated using a fiber optic displacement sensor based on an intensity modulation technique. The proposed sensor uses a bundled plastic optical fiber (POF as a probe in conjunction with a flat mirror as a target. It is obtained that the peak voltage reduces with increasing cholesterol concentration. The sensor is capable of measuring the cholesterol concentration ranging from 0 to 300 ppm in a distilled water with a measured sensitivity of 0.01 mV/ppm, a linearity of more than 99.62 % and a resolution of 3.9188 ppm. The proposed sensor also shows a high degree of stability and good repeatability. The simplicity of design, accuracy, flexible dynamic range, and the low cost of fabrication are favorable attributes of the sensor and beneficial for real- field applications. Fiber optic sensors

  5. Measurements of radon activity concentrations in air at Niska spa

    International Nuclear Information System (INIS)

    Adrovic, F.; Vuckovic, B.; Ninkovic, M.

    2004-01-01

    Radon activity concentrations in air were measured in the recreational-tourist center of Niska Banja. Alpha Guard PQ 2000/ MC50 instrumentation (Genitron instruments, Frankfurt) was used. The observed indoor radon concentrations in the air of the Radon Hotel pool lay within the range of 0.980-1.908 kBq/m 3 and were directly dependent on the exhalation of radon from thermomineral waters. Radon concentrations were also measured outdoors, at locations for capping thermomineral water, as well as at locations for draining used water from the Radon Hotel pool. Outdoor radon concentrations as high as over 500 Bq/m 3 were observed. Gamma dose rates were measured in parallel and found to lie within the range of 72-420 nSv/h. The gamma doses correlated well with the observed radon levels. The largest gamma dose rates in air were measured in the pool of Radon Hotel and at the site where this thermomineral water is being capped

  6. Measurements of ion concentration in gasoline and diesel engine exhaust

    Science.gov (United States)

    Yu, Fangqun; Lanni, Thomas; Frank, Brian P.

    The nanoparticles formed in motor vehicle exhaust have received increasing attention due to their potential adverse health effects. It has been recently proposed that combustion-generated ions may play a critical role in the formation of these volatile nanoparticles. In this paper, we design an experiment to measure the total ion concentration in motor vehicle engine exhaust, and report some preliminary measurements in the exhaust of a gasoline engine (K-car) and a diesel engine (diesel generator). Under the experimental set-up reported in this study and for the specific engines used, the total ion concentration is ca. 3.3×10 6 cm -3 with almost all of the ions smaller than 3 nm in the gasoline engine exhaust, and is above 2.7×10 8 cm -3 with most of the ions larger than 3 nm in the diesel engine exhaust. This difference in the measured ion properties is interpreted as a result of the different residence times of exhaust inside the tailpipe/connecting pipe and the different concentrations of soot particles in the exhaust. The measured ion concentrations appear to be within the ranges predicted by a theoretical model describing the evolution of ions inside a pipe.

  7. Laser system for measuring small changes in plasma tracer concentrations.

    Science.gov (United States)

    Klaesner, J W; Pou, N A; Parker, R E; Galloway, R L; Roselli, R J

    1996-01-01

    The authors developed a laser-diode system that can be used for on-line optical concentration measurements in physiologic systems. Previous optical systems applied to whole blood have been hampered by artifacts introduced by red blood cells (RBCs). The system introduced here uses a commercially available filter cartridge to separate RBCs from plasma before plasma concentration measurements are made at a single wavelength. The filtering characteristics of the Cellco filter cartridge (#4007-10, German-town, MD) were adequate for use in the on-line measurement system. The response time of the filter cartridge was less than 40 seconds, and the sieving characteristics of the filter for macromolecules were excellent, with filtrate-to-plasma albumin ratios of 0.98 +/- 0.11 for studies in sheep and 0.94 +/- 0.15 for studies in dogs. The 635-nm laser diode system developed was shown to be more sensitive than the spectrophotometer used in previous studies (Klaesner et al., Annals of Biomedical Engineering, 1994; 22, 660-73). The new system was used to measure the product of filtration coefficient (Kfc) and reflection coefficient for albumin (delta f) in an isolated canine lung preparation. The delta fKfc values [mL/(cmH2O.min.100 g dry lung weight)] measured with the laser diode system (0.33 +/- 0.22) compared favorably with the delta fKfc obtained using a spectrophotometer (0.27 +/- 0.20) and with the Kfc obtained using the blood-corrected gravimetric method (0.32 +/- 0.23). Thus, this new optical system was shown to accurately measure plasma concentration changes in whole blood for physiologic levels of Kfc. The same system can be used with different optical tracers and different source wavelengths to make optical plasma concentration measurements for other physiologic applications.

  8. Salinomycin, a polyether ionophoric antibiotic, inhibits adipogenesis

    International Nuclear Information System (INIS)

    Szkudlarek-Mikho, Maria; Saunders, Rudel A.; Yap, Sook Fan; Ngeow, Yun Fong; Chin, Khew-Voon

    2012-01-01

    Highlights: ► Salinomycin inhibits preadipocyte differentiation into adipocytes. ► Salinomycin inhibits transcriptional regulation of adipogenesis. ► Pharmacological effects of salinomycin suggest toxicity in cancer therapy. -- Abstract: The polyether ionophoric antibiotics including monensin, salinomycin, and narasin, are widely used in veterinary medicine and as food additives and growth promoters in animal husbandry including poultry farming. Their effects on human health, however, are not fully understood. Recent studies showed that salinomycin is a cancer stem cell inhibitor. Since poultry consumption has risen sharply in the last three decades, we asked whether the consumption of meat tainted with growth promoting antibiotics might have effects on adipose cells. We showed in this report that the ionophoric antibiotics inhibit the differentiation of preadipocytes into adipocytes. The block of differentiation is not due to the induction of apoptosis nor the inhibition of cell proliferation. In addition, salinomycin also suppresses the transcriptional activity of the CCAAT/enhancer binding proteins and the peroxisome proliferator-activated receptor γ. These results suggest that the ionophoric antibiotics can be exploited as novel anti-obesity therapeutics and as pharmacological probes for the study of adipose biology. Further, the pharmacological effects of salinomycin could be a harbinger of its toxicity on the adipose tissue and other susceptible target cells in cancer therapy.

  9. Salinomycin, a polyether ionophoric antibiotic, inhibits adipogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Szkudlarek-Mikho, Maria; Saunders, Rudel A. [Department of Medicine, Biochemistry and Cancer Biology, Center for Diabetes and Endocrine Research, College of Medicine, University of Toledo, Toledo, OH 43614 (United States); Yap, Sook Fan [Faculty of Medicine and Health Sciences, Department of Pre-Clinical Sciences, University of Tunku Abdul Rahman (Malaysia); Ngeow, Yun Fong [Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603 (Malaysia); Chin, Khew-Voon, E-mail: khew-voon.chin@utoledo.edu [Department of Medicine, Biochemistry and Cancer Biology, Center for Diabetes and Endocrine Research, College of Medicine, University of Toledo, Toledo, OH 43614 (United States)

    2012-11-30

    Highlights: Black-Right-Pointing-Pointer Salinomycin inhibits preadipocyte differentiation into adipocytes. Black-Right-Pointing-Pointer Salinomycin inhibits transcriptional regulation of adipogenesis. Black-Right-Pointing-Pointer Pharmacological effects of salinomycin suggest toxicity in cancer therapy. -- Abstract: The polyether ionophoric antibiotics including monensin, salinomycin, and narasin, are widely used in veterinary medicine and as food additives and growth promoters in animal husbandry including poultry farming. Their effects on human health, however, are not fully understood. Recent studies showed that salinomycin is a cancer stem cell inhibitor. Since poultry consumption has risen sharply in the last three decades, we asked whether the consumption of meat tainted with growth promoting antibiotics might have effects on adipose cells. We showed in this report that the ionophoric antibiotics inhibit the differentiation of preadipocytes into adipocytes. The block of differentiation is not due to the induction of apoptosis nor the inhibition of cell proliferation. In addition, salinomycin also suppresses the transcriptional activity of the CCAAT/enhancer binding proteins and the peroxisome proliferator-activated receptor {gamma}. These results suggest that the ionophoric antibiotics can be exploited as novel anti-obesity therapeutics and as pharmacological probes for the study of adipose biology. Further, the pharmacological effects of salinomycin could be a harbinger of its toxicity on the adipose tissue and other susceptible target cells in cancer therapy.

  10. Salinomycin, A Polyether Ionophoric Antibiotic, Inhibits Adipogenesis

    Science.gov (United States)

    Szkudlarek-Mikho, Maria; Saunders, Rudel A.; Yap, Sook Fan; Ngeow, Yun Fong; Chin, Khew-Voon

    2012-01-01

    The polyether ionophoric antibiotics including monensin, salinomycin, and narasin, are widely used in veterinary medicine and as food additives and growth promoters in animal husbandry including poultry farming. Their effects on human health, however, are not fully understood. Recent studies showed that salinomycin is a cancer stem cell inhibitor. Since poultry consumption has risen sharply in the last three decades, we asked whether the consumption of meat tainted with growth promoting antibiotics might have effects on adipose cells. We showed in this report that the ionophoric antibiotics inhibit the differentiation of preadipocytes into adipocytes. The block of differentiation is not due to the induction of apoptosis nor the inhibition of cell proliferation. In addition, salinomycin also suppresses the transcriptional activity of the CCAAT/enhancer binding proteins and the peroxisome proliferator-activated receptor γ. These results suggest that the ionophoric antibiotics can be exploited as novel anti-obesity therapeutics and as pharmacological probes for the study of adipose biology. Further, the pharmacological effects of salinomycin could be a harbinger of its toxicity on the adipose tissue and other susceptible target cells in cancer therapy. PMID:23123626

  11. Radon concentration measurements in the desert caves of Saudi Arabia

    International Nuclear Information System (INIS)

    Al-Mustafa, Hanan; Al-Jarallah, M.I.; Fazal-ur-Rehman; Abu-Jarad, F.

    2005-01-01

    Beneath the harsh deserts of Saudi Arabia lie dark chambers and complex mazes filled with strange shapes and wondrous beauty. Radon concentration measurements have been carried out in the desert caves of Al-Somman Plateau in the Eastern Province of Saudi Arabia. Passive radon dosimeters, based on alpha particle etch track detectors with an inlet filter, were used in this study. A total of 59 dosimeters were placed in five caves for a period of six months. Out of 59 dosimeters, 37 could be collected for analysis. Measurements showed significant variations in radon concentrations in caves depending upon their natural ventilation. The results of the study show that the average radon concentration in the different caves ranges from 74 up to 451Bqm -3 . The average radon concentration in four of the caves was low in the range 74-114Bqm -3 . However, one cave showed an average radon concentration of 451Bqm -3 . Radon is not a problem for tourists in the majority of caves. However, sometimes it may imply some limitation to the working time of guides

  12. Radon concentration measurements in the desert caves of Saudi Arabia

    Energy Technology Data Exchange (ETDEWEB)

    Al-Mustafa, Hanan [Women College, P. O. Box 838, Dammam 31113 (Saudi Arabia); Al-Jarallah, M.I. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)]. E-mail: mibrahim@kfupm.edu.sa; Fazal-ur-Rehman [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Abu-Jarad, F. [Radiation Protection Unit, Environmental Protection Department, Saudi Aramco P.O. Box 13027, Dhahran 31311 (Saudi Arabia)

    2005-11-15

    Beneath the harsh deserts of Saudi Arabia lie dark chambers and complex mazes filled with strange shapes and wondrous beauty. Radon concentration measurements have been carried out in the desert caves of Al-Somman Plateau in the Eastern Province of Saudi Arabia. Passive radon dosimeters, based on alpha particle etch track detectors with an inlet filter, were used in this study. A total of 59 dosimeters were placed in five caves for a period of six months. Out of 59 dosimeters, 37 could be collected for analysis. Measurements showed significant variations in radon concentrations in caves depending upon their natural ventilation. The results of the study show that the average radon concentration in the different caves ranges from 74 up to 451Bqm{sup -3}. The average radon concentration in four of the caves was low in the range 74-114Bqm{sup -3}. However, one cave showed an average radon concentration of 451Bqm{sup -3}. Radon is not a problem for tourists in the majority of caves. However, sometimes it may imply some limitation to the working time of guides.

  13. Estimates of CO2 traffic emissions from mobile concentration measurements

    Science.gov (United States)

    Maness, H. L.; Thurlow, M. E.; McDonald, B. C.; Harley, R. A.

    2015-03-01

    We present data from a new mobile system intended to aid in the design of upcoming urban CO2-monitoring networks. Our collected data include GPS probe data, video-derived traffic density, and accurate CO2 concentration measurements. The method described here is economical, scalable, and self-contained, allowing for potential future deployment in locations without existing traffic infrastructure or vehicle fleet information. Using a test data set collected on California Highway 24 over a 2 week period, we observe that on-road CO2 concentrations are elevated by a factor of 2 in congestion compared to free-flow conditions. This result is found to be consistent with a model including vehicle-induced turbulence and standard engine physics. In contrast to surface concentrations, surface emissions are found to be relatively insensitive to congestion. We next use our model for CO2 concentration together with our data to independently derive vehicle emission rate parameters. Parameters scaling the leading four emission rate terms are found to be within 25% of those expected for a typical passenger car fleet, enabling us to derive instantaneous emission rates directly from our data that compare generally favorably to predictive models presented in the literature. The present results highlight the importance of high spatial and temporal resolution traffic data for interpreting on- and near-road concentration measurements. Future work will focus on transport and the integration of mobile platforms into existing stationary network designs.

  14. Market power in electricity markets: Beyond concentration measures

    International Nuclear Information System (INIS)

    Borenstein, S.; Bushnell, J.; Knittel, C.R.

    1999-01-01

    The wave of electricity market restructuring both within the US and abroad has brought the issue of horizontal market power to the forefront of energy policy. Traditionally, estimation and prediction of market power has relied heavily on concentration measures. In this paper, the authors discuss the weaknesses of concentration measures as a viable measure of market power in the electricity industry, and they propose an alternative method based on market simulations that take advantage of existing plant level data. The authors discuss results from previous studies they have performed, and present new results that allow for the detection of threshold demand levels where market power is likely to be a problem. In addition, the authors analyze the impact of that recent divestitures in the California electricity market will have on estimated market power. They close with a discussion of the policy implications of the results

  15. Measurement of 222Rn in soil concentrations in interstitial air

    International Nuclear Information System (INIS)

    Duenas, C.; Fernandez, M.C.; Carretero, J.; Liger, E.

    1996-01-01

    Measurements of 222 Rn soil concentrations were made by inserting stainless-steel sampling tubes into the soil. The samples of the soil interstitial air were taken in to pre-evacuated 1 L glass flasks. The glass flasks are cylindrical and coated with a film of ZnS(Ag). 222 Rn was measured by counting the alpha particles emitted by 222 Rn and its daughter products, 218 Po and 214 Bi, when they reached radioactive equilibrium. Measurements of 222 Rn gas concentrations in the soil air interstices by the method at different depths were used to calculate the diffusion coefficient of the 222 Rn in the soil air. This study has been carried out for diverse soils. (Author)

  16. Performance tests for instruments measuring radon activity concentration

    International Nuclear Information System (INIS)

    Beck, T.R.; Buchroeder, H.; Schmidt, V.

    2009-01-01

    Performance tests of electronic instruments measuring the activity concentration of 222 Rn have been carried out with respect to the standard IEC 61577-2. In total, 9 types of instrument operating with ionization chambers or electrostatic collection have been tested for the influence of different climatic and radiological factors on the measurement characteristics. It is concluded that all types of instrument, which are commercially available, are suitable for indoor radon measurements. Because of the dependence on climatic conditions, the outdoor use is partly limited.

  17. Measurement of mean radon concentrations in the Tokai districts

    International Nuclear Information System (INIS)

    Iida, Takao; Ikebe, Yukimasa; Yamanishi, Hirokuni

    1989-01-01

    This paper describes an electrostatic integrating radon monitor designed for the environmental radon monitoring and longterm measurements of mean radon concentrations in outdoor and indoor air. The position of the collecting electrode within the monitor was determined based on the calculation of the internal electric field. The radon exchange rate between the monitor and the outside air through the filter was 0.75 h -1 . The exchange rate can make the radon concentration inside the monitor to follow thoroughly the outside concentration. Since the electrostatic collection of RaA + ( 218 Po + ) atoms depends on the humidity of the air, the inside of the monitor was dehumidified with a diphosphorus pentaoxide (P 2 O 5 ) drying agent which is powerful and dose not absorb radon gas. From the relationship between track density and radon exposure, the calibration factor was derived to be 0.52 ± 0.002 tracks cm -2 (Bq m -3 h) -1 . The detection limit of mean radon level is 1.2 Bq m -3 for an exposure time fo 2 months. The mean radon concentrations in various environments were measured through the year using the monitors this developed. The annual mean outdoor radon level in the Tokai districts was 7.0 Bq m -3 . The mean radon concentrations was found to vary from 3.5 to 11.7 Bq m -3 depending upon the geographical conditions even in this relatively small region. The annual indoor radon concentrations at Nagoya and Sapporo ranged from 6.4 to 11.9 Bq m -3 and from 15.5 to 121.1 Bq m -3 , respectively, with the type of building material and the ventilation rate. The mean radon concentrations in tightly built houses selected at Sapporo are about 10 times as high as those in drafty houses at Nagoya. (author)

  18. Radon concentration measurements in waters in Greece and Cyprus

    International Nuclear Information System (INIS)

    Louizi, A.; Nikolopoulos, D.; Tzortzi, A.; Thanassas, D.; Serefoglou, A.; Georgiou, E.; Vogiannis, E.; Koukouliou, V.

    2004-01-01

    A total of 35 measurements in Greece and 15 in Cyprus were performed. Radon concentrations in drinking water in Greece were from (1.1±0.5) to (410±50) Bq/L. The corresponding concentrations in underground potable waters in Cyprus ranged between (0.4±0.3) Bq/L and (15±4) Bq/L. High concentrations, viz. (120±20), (320±40) and (410±50) Bq/L, were observed in three samples collected from the city of Arnea Chalkidekis in northern Greece. One water sample from Lesvos Island (north-eastern part of Greece) exhibited a radon concentration of (140±20) Bq/L. Six samples of hot spring water from the city of Loutraki (Attica prefecture), characterized as 'medicinal drinking water', contained concentrations of radon between (220±10) and (340±20) Bq/L. Radon concentrations in potable and non-potable underground water in Greece and Cyprus ranged between (0.4±0.3) and (15±4) Bq/L, whereas in surface water the range was from (2.7±0.8) to (24±6) Bq/L. (P.A.)

  19. Measurements of radon concentrations at caves in Jeju

    Energy Technology Data Exchange (ETDEWEB)

    Go, S. H.; Kang, D. H.; Jung, B. J. [Cheju National University, Cheju (Korea, Republic of)

    2004-07-01

    Radon is a radioactive gas emitting {alpha} particles. It is chemically stable due to its inert characteristic. While its daughter products, {sup 218}Po, {sup 214}Bi, {sup 214}Pb and {sup 214}Po, attached with aerosol particles, is known to cause lung cancer. As radon is produced from uranium and thorium, it accumulates in poorly ventilative underground voids such as caves and mine. Radon concentrations at caves in Jeju were measured in this study. The measurements were made by setting three CR-39 detectors for 70 days at 2 {approx} 4 positions in Manjang, Hyupjae and Ssangyong caves. The radon levels of the caves spread 403.1 . 606.7 Bq/m{sup 3}. With these results, it is concluded that the Jeju caves have 6 times higher radon concentrations than ordinary house of 65.3 Bq/m{sup 3} and that they are higher than Seoul subway stations due to poor ventilation. While, the caves in Jeju have lower radon concentrations than limestone caves of Robin Hood. The radon concentration in the middle of Manjang cave is slightly higher than the action level in the work place of 500 Bq/m{sup 3} suggested by the ICRP. The measurement errors are estimated to be less than 5 % from its calibration factor.

  20. Measurements of radon concentrations at caves in Jeju

    International Nuclear Information System (INIS)

    Go, S. H.; Kang, D. H.; Jung, B. J.

    2004-01-01

    Radon is a radioactive gas emitting α particles. It is chemically stable due to its inert characteristic. While its daughter products, 218 Po, 214 Bi, 214 Pb and 214 Po, attached with aerosol particles, is known to cause lung cancer. As radon is produced from uranium and thorium, it accumulates in poorly ventilative underground voids such as caves and mine. Radon concentrations at caves in Jeju were measured in this study. The measurements were made by setting three CR-39 detectors for 70 days at 2 ∼ 4 positions in Manjang, Hyupjae and Ssangyong caves. The radon levels of the caves spread 403.1 . 606.7 Bq/m 3 . With these results, it is concluded that the Jeju caves have 6 times higher radon concentrations than ordinary house of 65.3 Bq/m 3 and that they are higher than Seoul subway stations due to poor ventilation. While, the caves in Jeju have lower radon concentrations than limestone caves of Robin Hood. The radon concentration in the middle of Manjang cave is slightly higher than the action level in the work place of 500 Bq/m 3 suggested by the ICRP. The measurement errors are estimated to be less than 5 % from its calibration factor

  1. Handling of Polyvinylsiloxane Versus Polyether for Implant Impressions.

    Science.gov (United States)

    Farhan, Daniel; Lauer, Wiebke; Heydecke, Guido; Aarabi, Ghazal; Reissmann, Daniel R

    2016-01-01

    This study compared polyvinylsiloxane with polyether in handling dental impressions. Each participant (N = 39) made four impressions, each a combination of pickup and reseating techniques with polyether or polyvinylsiloxane, of one implant cast representing a specific clinical situation (tooth gaps, limited residual dentition, or edentulous jaw). Handling of impressions was subsequently rated by using a 12-item questionnaire with 100-mm visual analog scales. While mean satisfaction scores were higher for polyvinylsiloxane than for polyether (69.5/63.0, P < .001), differences among subgroups were statistically significant only for pickup technique, limited residual dentition, and edentulous jaw. Implant impressions made with polyvinylsiloxane using a pickup technique seem to be the best option for most clinical situations.

  2. Synthesis and properties of amphiphilic hyperbranched polyethers as pigment dispersant

    Science.gov (United States)

    Xu, Q.; Zhou, Y. J.; Long, S. J.; Liu, Y. G.; Li, J. H.

    2018-01-01

    Hyperbranched polymers possess prominent properties such as low viscosity, good solubility, high rheological property, environmental non-toxic, and so on, which have potential applications in coatings. In this study, the amphiphilic hyperbranched polyethers (AHPs) consisting of hydrophobic hyperbranched polyethers core and hydrophilic poly (ethylene glycol) arms with different degree of branching (DB) under various reaction temperatures was prepared by the cation ring-opening polymerization. Their structures were characterized by IR, 13CNMR and GPC. Their dispersion properties for pigment particles were investigated. The AHP47 with 0.47 DB was found to have good dispersion properties for Yellow HGR. This work would provide experimental data and theoretical foundation for the application of hyperbranched polyethers in environmental protection coating.

  3. Measurement of the concentration of radon in the air

    International Nuclear Information System (INIS)

    Aten, J.B.Th.; Bierhuizen, H.W.J.; Hoek, L.P. van; Ros, D.; Weber, J.

    1975-01-01

    A simple transportable air monitoring apparatus was developed for controlling the radon contamination of air in laboratory rooms. It is not highly accurate but is sufficient to register the order of magnitude of the radon concentration. Air is pumped through a filter for one or two hours and an alpha decay curve of the dust on the filter is determined. Scintillation counting forty minutes after sampling indicates the radon activity. The calibration method of measuring the equilibrium of daughter product concentrations is discussed extensively

  4. Measurement of Alpha Emitters Concentration in Imported Cigarettes

    International Nuclear Information System (INIS)

    Nasser Allah, Z.K.; Musa, W.A.; AL-Rawi, A.A.S.

    2011-01-01

    The aime of this study was to measured the alpha emitters concentration of (15) different kinds of imported cigarettes. the nuclear reaction used U-235(n, f) obtained by the bombardment of U-235 with thermal neutrons from (Am B e)neutron source with thermal flux of(5*10 3 n.cm -2 .s -1 ). The Results obtained showed the values of the Uranium concentration, and varies from (0.041 ppm) in five stares kind to (2.374ppm) in Machbeth (chocolate) 100's kind. All the result obtained are within the limit levels as given by UNSCAR data

  5. Monitoring and measurement of oxygen concentrations in liquid sodium

    International Nuclear Information System (INIS)

    Smith, D.L.

    1976-01-01

    The measurement of oxygen concentrations in sodium at levels of interest for LMFBR applications is reviewed. Additional data are presented to support the validity of the vanadium-equilibration method as a reference for determination of oxygen concentrations in sodium at levels equal to or less than 15 ppM. Operating experience with electrochemical oxygen meters that have a thoria-yttria electrolyte and a Na--Na 2 O reference electrode is described. Meter lifetimes in excess of one year have generally been achieved for operating temperatures of 352 and 402 0 C, and fairly stable emfs have been observed for periods of several months. 7 fig, 21 references

  6. Measurement of radon concentration in air employing Lucas chamber

    International Nuclear Information System (INIS)

    Machaj, B.

    1997-01-01

    The results of investigations aimed to determine the main features of radon concentration gauge in air, employing 0.17 L Lucas chamber, and air sample forced by an air pump are presented. For two hour sampling and measuring cycle time the dynamic error in the worst case (first read out) equals 5 % relative to the step jump of radon concentration. This is due to the increase of activity of the decay products in the chamber. It was observed that the short lived radon decay products (Po-218, Pb-214, Bi-214) are depositing on the walls of the chamber and they are not removed by flushing the chamber with air. (author)

  7. Electrochemical investigation of sulfonated poly(ether ether ketone)/clay nanocomposite membranes for moderate temperature fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Hasani-Sadrabadi, Mohammad Mahdi [Polymer Engineering Department, Amirkabir University of Technology, Tehran (Iran); Biomedical Engineering Department, Amirkabir University of Technology, Tehran (Iran); Dashtimoghadam, Erfan; Sarikhani, Kaveh [Polymer Engineering Department, Amirkabir University of Technology, Tehran (Iran); Majedi, Fatemeh S. [Biomedical Engineering Department, Amirkabir University of Technology, Tehran (Iran); Khanbabaei, Ghader [Polymer Science and Technology Division, Research Institute of Petroleum Industry, Tehran (Iran)

    2010-05-01

    In the present study, polyelectrolyte membranes based on partially sulfonated poly(ether ether ketone) (sPEEK) with various degrees of sulfonation are prepared. The optimum degree of sulfonation is determined according to the transport properties and hydrolytic stability of the membranes. Subsequently, various amounts of the organically modified montmorillonite (MMT) are introduced into the sPEEK matrices via the solution intercalation technique. The proton conductivity and methanol permeability measurements of the fabricated composite membranes reveal a high proton to methanol selectivity, even at elevated temperatures. Membrane based on sPEEK and 1 wt% of MMT, as the optimum nanoclay composition, exhibits a high selectivity and power density at the concentrated methanol feed. Moreover, it is found that the optimum nanocomposite membrane not only provides higher performance compared to the neat sPEEK and Nafion {sup registered} 117 membranes, but also exhibits a high open circuit voltage (OCV) at the elevated methanol concentration. Owing to the high proton conductivity, reduced methanol permeability, high power density, convenient processability and low cost, sPEEK/MMT nanocomposite membranes could be considered as the alternative membranes for moderate temperature direct methanol fuel cell applications. (author)

  8. Method and device for measuring the smoke concentration in air

    International Nuclear Information System (INIS)

    Rennemo, B.

    1994-01-01

    The patent deals with a method and a device for measuring the smoke concentration in air. In a smoke chamber are located two electrodes, connected to a voltage source for forming a circuit in which a DC current flows. A radioactive radiation source to ionize the air molecules is located in the vicinity of the smoke chamber, so that the number of ionized air molecules which are formed is dependent upon the radiation intensity of the ion source and the concentration of smoke particles in the smoke chamber. The charging voltage will further imply that a cloud of high ion concentration is built up close to the surface of the electrodes. The ion cloud will be discharged capacitively upon a plurality of short voltages pulses applied to the electrodes to thereby result in current pulses substantially greater than the DC current flowing through the chamber. 8 figs

  9. Design and synthesis of chalcone-based macrocyclic polyethers

    Directory of Open Access Journals (Sweden)

    Subrata Jana

    2015-12-01

    Full Text Available A series of chalcone-based macrocyclic ethers have been synthesized. These macrocyclic ethers contain polyether as well as extended conjugation to the benzene ring to function as fluorescent sensor for cations. The modeling studies show that the chalcone part of the receptors remains partially out of plane from the polyether part and the keto moiety of the receptors always directed outwardly in the receptor itself. This may be changed during the recognition of metal ions. The tendency of the fluorophore, to be out of plane, increases with increasing the ring size.

  10. Diagnostics of and measures against radon concentrations in a dwelling

    International Nuclear Information System (INIS)

    Berger, H.

    1994-02-01

    Results are presented of measurements in a test-dwelling in the period april 1993 - november 1993. The purpose of the measurements was to investigate the possibilities of using a blower door (a fan in a wall of the dwelling) for specifying sources of radon in the dwelling, employing the diagnostic method developed at the KVI (Nuclear Physics Accelerator Institute in Groningen, Netherlands). Special attention is paid to the measurement of two input variables for the diagnostic method: transparency of the walls of the dwelling and the strength of static sources. Also measures aimed at reducing radon concentrations in the dwelling are discussed. The main conclusions are that (a) the pressure-variation method is a valid procedure to measure the transparency of walls and floors; (b) the blower door is a suitable technique for arriving at a correct diagnosis; and (c) over-pressurizing the crawl-space is the most effective measure in reducing the radon concentration of the crawl-space. More research on air flows in the soil is recommended. 21 figs., 28 tabs., 7 refs

  11. Measuring Low Concentrations of Liquid Water in Soil

    Science.gov (United States)

    Buehler, Martin

    2009-01-01

    An apparatus has been developed for measuring the low concentrations of liquid water and ice in relatively dry soil samples. Designed as a prototype of instruments for measuring the liquidwater and ice contents of Lunar and Martian soils, the apparatus could also be applied similarly to terrestrial desert soils and sands. The apparatus is a special-purpose impedance spectrometer: Its design is based on the fact that the electrical behavior of a typical soil sample is well approximated by a network of resistors and capacitors in which resistances decrease and capacitances increase (and, hence, the magnitude of impedance decreases) with increasing water content.

  12. Apparatus for measuring the concentration of a gas

    International Nuclear Information System (INIS)

    Manin, Ange.

    1974-01-01

    The apparatus described for measuring the concentration of a gas in an atmosphere is of the kind which has an ionization chamber with an internal radioactive source and associated electronics enabling the ionization current crossing the chamber to be measured. It includes at least one cylindrical metal grid forming an electrode brought to a high voltage in relation to a cylindrical collection electrode fitted to the axis of the grid coated with a radioactive deposit and, around this grid, a screen acting as a protective envelope. The radioactive deposit is tritiated titanium [fr

  13. Laser metrology in fluid mechanics granulometry, temperature and concentration measurements

    CERN Document Server

    Boutier, Alain

    2013-01-01

    In fluid mechanics, non-intrusive measurements are fundamental in order to improve knowledge of the behavior and main physical phenomena of flows in order to further validate codes.The principles and characteristics of the different techniques available in laser metrology are described in detail in this book.Velocity, temperature and concentration measurements by spectroscopic techniques based on light scattered by molecules are achieved by different techniques: laser-induced fluorescence, coherent anti-Stokes Raman scattering using lasers and parametric sources, and absorption sp

  14. Measurement of indoor radon concentration by CR-39 track detector

    International Nuclear Information System (INIS)

    Yamamoto, Masayoshi; Yoneda, Shigeru; Nakanishi, Takashi.

    1990-01-01

    A convenient and cheap method for measuring indoor radon ( 222 Rn) concentration with a CR-39 track detector is described. The detector consisted of two sheets of CR-39 enclosed separately in two plastic pots : one covered by a filter (cup method) and another no covering (bare method). The bare method was used here to supplement the cup method. To compare with the result of the CR-39 detector, alpha-ray spectrometry was carried out with a Si(Au) detector in a controlled radon exposure chamber. Indoor radon concentration measured in 133 houses in several districts of Ishikawa Prefecture have been found to range from 6 Bq/m 3 to as high as 113 Bq/m 3 with a median value of 24 Bq/m 3 . The problems to measure indoor radon concentration using the CR-39 detector are also discussed with emphasis on the position of setting the detector in the room and the possible thoron contribution to the detector. (author)

  15. Evaluation of the efficiency of silicone polyether additives as foam inhibitor in crude oil

    International Nuclear Information System (INIS)

    Fraga, Assis K.; Santos, Raquel F.; Mansur, Claudia R.E.

    2011-01-01

    This work evaluates the chemical and physico-chemical properties of commercial anti-foam products based on silicone polyethers along with their efficiency in inhibiting foaming. The commercial surfactants were characterized by nuclear magnetic resonance (NMR) spectroscopy, size exclusion chromatography (SEC), determination of solubility in different solvents and measurement of the surface and interfacial tensions. A method to test the formation of foam in oil was used to mimic the operating conditions in gas-oil separators. The results show that the most polar additive was the most efficient in breaking up the foam. (author)

  16. Isopropyl Myristate-Modified Polyether-Urethane Coatings as Protective Barriers for Implantable Medical Devices

    Science.gov (United States)

    Roohpour, Nima; Wasikiewicz, Jaroslaw M.; Moshaverinia, Alireza; Paul, Deepen; Rehman, Ihtesham U.; Vadgama, Pankaj

    2009-01-01

    Polyurethane films have potential applications in medicine, especially for packaging implantable medical devices. Although polyether-urethanes have superior mechanical properties and are biocompatible, achieving water resistance is still a challenge. Polyether based polyurethanes with two different molecular weights (PTMO1000, PTMO2000) were prepared from 4,4’-diphenylmethane diisocyanate and poly(tetra-methylene oxide). Polymer films were introduced using different concentrations (0.5-10 wt %) of isopropyl myristate lipid (IPM) as a non-toxic modifying agent. The physical and mechanical properties of these polymers were characterised using physical and spectroscopy techniques (FTIR, Raman, DSC, DMA, tensile testing). Water contact angle and water uptake of the membranes as a function of IPM concentration was also determined accordingly. The FTIR and Raman data indicate that IPM is dispersed in polyurethane at ≤ 2wt% and thermal analysis confirmed this miscibility to be dependent on soft segment length. Modified polymers showed increased tensile strength and failure strain as well as reduced water uptake by up to 24% at 1-2 wt% IPM.

  17. Isopropyl Myristate-Modified Polyether-Urethane Coatings as Protective Barriers for Implantable Medical Devices

    Directory of Open Access Journals (Sweden)

    Pankaj Vadgama

    2009-06-01

    Full Text Available Polyurethane films have potential applications in medicine, especially for packaging implantable medical devices. Although polyether-urethanes have superior mechanical properties and are biocompatible, achieving water resistance is still a challenge. Polyether based polyurethanes with two different molecular weights (PTMO1000, PTMO2000 were prepared from 4,4’-diphenylmethane diisocyanate and poly(tetra-methylene oxide. Polymer films were introduced using different concentrations (0.5-10 wt % of isopropyl myristate lipid (IPM as a non-toxic modifying agent. The physical and mechanical properties of these polymers were characterised using physical and spectroscopy techniques (FTIR, Raman, DSC, DMA, tensile testing. Water contact angle and water uptake of the membranes as a function of IPM concentration was also determined accordingly. The FTIR and Raman data indicate that IPM is dispersed in polyurethane at ≤ 2wt% and thermal analysis confirmed this miscibility to be dependent on soft segment length. Modified polymers showed increased tensile strength and failure strain as well as reduced water uptake by up to 24% at 1-2 wt% IPM.

  18. Langmuir and Langmuir-Blodgett films of multifunctional, amphiphilic polyethers with cholesterol moieties.

    Science.gov (United States)

    Reuter, Sascha; Hofmann, Anna M; Busse, Karsten; Frey, Holger; Kressler, Jörg

    2011-03-01

    Langmuir films of multifunctional, hydrophilic polyethers containing a hydrophobic cholesterol group (Ch) were studied by surface pressure-mean molecular area (π-mmA) measurements and Brewster angle microscopy (BAM). The polyethers were either homopolymers or diblock copolymers of linear poly(glycerol) (lPG), linear poly(glyceryl glycidyl ether) (lPGG), linear poly(ethylene glycol) (lPEG), or hyperbranched poly(glycerol) (hbPG). Surface pressure measurements revealed that the homopolymers lPG and hbPG did not stay at the water surface after spreading and solvent evaporation, in contrast to lPEG. Because of the incorporation of the Ch group in the polymer structure, stable Langmuir films were formed by Ch-lPG(n), Ch-lPGG(n), and Ch-hbPG(n). The Ch-hbPG(n), Ch-lPEG(n), Ch-lPEG(n)-b-lPG(m), Ch-lPEG(n)-b-lPGG(m), and Ch-lPEG(n)-b-hbPG(m) systems showed an extended plateau region assigned to a phase transition involving the Ch groups. Typical hierarchically ordered morphologies of the LB films on hydrophilic substrates were observed for all Ch-initiated polymers. All LB films showed that Ch of the Ch-initiated homopolymers is able to crystallize. This strong tendency of self-aggregation then triggers further dewetting effects of the respective polyether entities. Fingerlike morphologies are observed for Ch-lPEG(69), since the lPEG(69) entity is able to undergo crystallization after transfer onto the silicon substrate.

  19. Radon concentration measurements in waters in Greece and Cyprus

    International Nuclear Information System (INIS)

    Louizi, A.; Nikolopoulos, D.; Tzortzi, A.; Thanassas, D.; Serefoglou, A.; Georgiou, E.; Vogiannis, E.; Koukouliou, V.

    2004-01-01

    The radon content of drinking water samples was determined with Alpha Guard Pro equipped with an appropriate unit (Aqua Kit). The samples were collected from water taps in dwellings located at various cities in Greece and Cyprus. In addition, surface water samples from rivers, lakes and seas as well as potable underground and hot spring water samples from Greece and Cyprus were also collected. For a precise determination of radon concentration in water samples, special procedures were followed both for sampling and transportation, as well as for measurement. Intercomparison experiments were designed and implemented before and during the study. Radon concentrations in drinking water samples in Greece ranged between 1.1 ± 0.5 Bq/L and 410±50 Bq/L. The corresponding concentrations in Cyprus ranged between 1.3 ± 0.8 Bq/L and 15±4 Bq/L. Three samples collected from the city of Arnea Chalkidikis (Northern Greece) exhibited high concentrations of 120±20 Bq/L, 320±40 Bq/L and 410±50 Bq/L. This city is identified as a high radon potential area. One water sample located in Lesvos Island (North-East part of Greece) exhibited radon concentration 140±20 Bq/L. Additional six samples displayed high concentrations in potable hot spring water samples. These samples which were collected from the city of Loutraki (Peloponnesus) ranged between 220-230 Bq/L. In addition, two samples characterized as 'medicinal drinking water' gave concentrations between 320 Bq/L and 340 Bq/L. For underground water samples the radon concentrations ranged between 1.2±0.7 Bq/L and 15±4 Bq/L, while for surface water samples the range was 2.7±0.8 Bq/L to 24±6 Bq/L. The observed concentrations of radon gas in potable water samples in Greece were found to be largely low. In Cyprus, they were all well below 15 Bq/L

  20. Measurement of plasma adenosine concentration: methodological and physiological considerations

    International Nuclear Information System (INIS)

    Gewirtz, H.; Brown, P.; Most, A.S.

    1987-01-01

    This study tested the hypothesis that measurements of plasma adenosine concentration made on samples of blood obtained in dipyridamole and EHNA (i.e., stopping solution) may be falsely elevated as a result of ongoing in vitro production and accumulation of adenosine during sample processing. Studies were performed with samples of anticoagulated blood obtained from anesthesized domestic swine. Adenosine concentration of ultra filtrated plasma was determined by HPLC. The following parameters were evaluated: (i) rate of clearance of [ 3 H]adenosine added to plasma, (ii) endogenous adenosine concentration of matched blood samples obtained in stopping solution alone, stopping solution plus EDTA, and perchloric acid (PCA), (iii) plasma and erythrocyte endogenous adenosine concentration in nonhemolyzed samples, and (iv) plasma adenosine concentration of samples hemolyzed in the presence of stopping solution alone or stopping solution plus EDTA. We observed that (i) greater than or equal to 95% of [ 3 H]adenosine added to plasma is removed from it by formed elements of the blood in less than 20 s, (ii) plasma adenosine concentration of samples obtained in stopping solution alone is generally 10-fold greater than that of matched samples obtained in stopping solution plus EDTA, (iii) deliberate mechanical hemolysis of blood samples obtained in stopping solution alone resulted in substantial augmentation of plasma adenosine levels in comparison with matched nonhemolyzed specimens--addition of EDTA to stopping solution prevented this, and (iv) adenosine content of blood samples obtained in PCA agreed closely with the sum of plasma and erythrocyte adenosine content of samples obtained in stopping solution plus EDTA

  1. A Comparative Evaluation of the Linear Dimensional Accuracy of Four Impression Techniques using Polyether Impression Material.

    Science.gov (United States)

    Manoj, Smita Sara; Cherian, K P; Chitre, Vidya; Aras, Meena

    2013-12-01

    There is much discussion in the dental literature regarding the superiority of one impression technique over the other using addition silicone impression material. However, there is inadequate information available on the accuracy of different impression techniques using polyether. The purpose of this study was to assess the linear dimensional accuracy of four impression techniques using polyether on a laboratory model that simulates clinical practice. The impression material used was Impregum Soft™, 3 M ESPE and the four impression techniques used were (1) Monophase impression technique using medium body impression material. (2) One step double mix impression technique using heavy body and light body impression materials simultaneously. (3) Two step double mix impression technique using a cellophane spacer (heavy body material used as a preliminary impression to create a wash space with a cellophane spacer, followed by the use of light body material). (4) Matrix impression using a matrix of polyether occlusal registration material. The matrix is loaded with heavy body material followed by a pick-up impression in medium body material. For each technique, thirty impressions were made of a stainless steel master model that contained three complete crown abutment preparations, which were used as the positive control. Accuracy was assessed by measuring eight dimensions (mesiodistal, faciolingual and inter-abutment) on stone dies poured from impressions of the master model. A two-tailed t test was carried out to test the significance in difference of the distances between the master model and the stone models. One way analysis of variance (ANOVA) was used for multiple group comparison followed by the Bonferroni's test for pair wise comparison. The accuracy was tested at α = 0.05. In general, polyether impression material produced stone dies that were smaller except for the dies produced from the one step double mix impression technique. The ANOVA revealed a highly

  2. Measurement of indoor and outdoor radon concentrations during Superstorm Sandy.

    Science.gov (United States)

    Kotrappa, Payasada; Paul, Prateek; Stieff, Alex; Stieff, Frederick

    2013-12-01

    Superstorm Sandy affected much of the US East Coast extending over 1800 km. It passed over the test location in the State of Maryland on 29 October 2012. Being 350 km away from the regions of highest intensity the storm was of lower intensity at the test location. Continuous radon monitors and passive radon monitors were used for the measurement. The test location was the basement of a single family home representing the indoor concentration. A partially opened garage of the same test home represented the outdoor radon concentration. In 24 h, the atmospheric pressure dropped from 990 to 960 mbar and the indoor radon concentration increased from 70 to 1500 Bq m(-3) and returned to the normal of 70 Bq m(-3) at the end of the storm. Throughout the storm, the outdoor radon concentration was not significantly affected. Probable reasons for such surprisingly large changes are discussed. However, the outdoor temperature dropped from 13°C to 7°C during the radon peak.

  3. Integrating measurements of indoor thoron and its progeny concentrations

    International Nuclear Information System (INIS)

    Zhuo, W.H.; Iida, T.; Hashiguchi, Y.

    2000-01-01

    In recent years, indoor surveys in Europe and Asia revealed that the dose contribution from thoron and its progeny can equal or even exceed that of radon and its progeny. For measuring thoron and its progeny, several methods had been reported. However, convenient, low-cost and time-integrating measuring methods which are suitable for large-scale surveys are still unavailable. To solve this problem, three integrating measuring methods with allyl diglycol carbonate plastic (CR-39) as detectors have recently been. The results indicated that they are suitable for estimating the indoor thoron and its progeny concentrations when the public exposure to thoron and its progeny is taken into account. Cup monitor - Former types of passive integrating 222 Rn and 220 Rn cup monitors had been reported. Recently, in order to improve the sensitivity of thoron detection, the air exchange rate between the inner and outer cup was enhanced, and the radius of the hemisphere was reduced to 37.5 mm. Furthermore, the procedure of detector exchange was made to be more convenient. Equilibrium-equivalent 222 Rn and 220 Rn concentrations monitor (EEC monitor) - The measuring system is composed of a monitor head and a diaphragm pump. The total weight of the system is less than 1.5 kg, which makes it portable. The construction of the monitor head and the measuring principle were also reported by the authors. Thoron progeny deposition rate monitor - The monitor is simply constituted a piece of CR-39 covered with thin sheets of absorbers. The thickness of the absorbers are adjusted to let only the α particles emitted from 212 Pb impinge on the detector. The concentrations of thoron progeny are estimated from the deposition rates, assuming that the deposition velocities of thoron progeny are constant in general dwellings. The improved cup monitor has higher sensitivity than former monitors, with a calibration factor of 1.59x10 -3 tracks·cm -2 (Bq·m -3 ·h) -1 for thoron. The accuracy of the ECC

  4. Temporal polyethism and worker specialization in the wasp, Vespula germanica.

    Science.gov (United States)

    Hurd, Christine R; Jeanne, Robert L; Nordheim, Erik V

    2007-01-01

    Temporal polyethism is a common mechanism of worker specialization observed in social insect species with large colony sizes, Vespula wasp colonies consist of thousands of monomorphic workers, yet studies based on small cohorts of workers report that temporal polyethism is either weak or completely absent in different Vespula species. Concerned that the small sample size of these studies precluded detection of temporal polyethism, several hundred, known-age Vespula germanica (F.) (Hymenoptera: Vespidae) workers were studied. High variability was found in the sequence and diversity of tasks workers perform, suggesting that V. germanica colonies exhibit weak temporal polyethism. The most common order in which tasks were taken up was 1) nest work, 2) pulp foraging, 3) carbohydrate foraging, and 4) protein foraging. However, only 61% of the wasps performed more than two of the tasks during their lives. Thorax size had a significant negative effect on the age at first foraging, but the magnitude of the effect was small. The daily ratio of task generalists to specialists was relatively constant despite the high turnover of workers, growth of the colony, and the colony's transition from rearing worker larvae to rearing reproductives. Over the course of their lives, 43% of the workers averaged more than one kind of task performed per day. Life history traits are identified that may explain why vespines with large colonies use a generalist strategy of labor division rather than the specialist strategy observed in honey bees (Apis mellifera) and large colonies of wasps (Polybia occidentalis).

  5. New bromotriterpene polyethers from the Indian alga Chondria armata

    Digital Repository Service at National Institute of Oceanography (India)

    Ciavatta, M.L.; Wahidullah, S.; DeSouza, L.; Scognamiglio, G.; Cimino, G.

    Six new bromotriterpene polyethers, armatol A-F (1-6), with a rearranged carbon skeleton, were isolated from the Indian Ocean red alga Chondria armata. The structures were characterized by spectroscopic techniques, in particular 1D- and 2D-NMR...

  6. Poly(ether ester amide)s for tissue engineering

    NARCIS (Netherlands)

    Deschamps, A.A.; van Apeldoorn, Aart A.; de Bruijn, Joost Dick; Grijpma, Dirk W.; Feijen, Jan

    2003-01-01

    Poly(ether ester amide) (PEEA) copolymers based on poly(ethylene glycol) (PEG), 1,4-butanediol and dimethyl-7,12-diaza-6,13-dione-1,18-octadecanedioate were evaluated as scaffold materials for tissue engineering. A PEEA copolymer based on PEG with a molecular weight of 300 g/mol and 25 wt% of soft

  7. Photodegradation of poly(ether sulphone). Part 2

    DEFF Research Database (Denmark)

    Norrman, K.; Krebs, Frederik C

    2004-01-01

    The photodegradation of poly(ether sulphone) (PES) was investigated systematically by time-of-flight SIMS (ToF-SIMS) and x-ray photoelectron spectroscopy (XPS). The effect of varying the irradiation dose, wavelength and the atmosphere was studied along with mechanistic photooxidation studies using...

  8. Thermodynamic parameters for polyether adducts with neutral molecules

    International Nuclear Information System (INIS)

    Spencer, J.N.; Zafar, A.I.; Ganunis, T.F.

    1992-01-01

    Using calorimetry, thermodynamic parameters for the interaction of neutral molecules with polyether adducts are determined. When compared to its analogous acyclic ether, no macrocyclic effect is observed for 12-crown-4. The ether's collective oxygen atoms' action determines interaction with acetonitrile and malononitrile, with dimethyltin dichloride having a specific oxygen-binding site. 14 refs., 1 tab

  9. Chemodiversity of Ladder-Frame Prymnesin Polyethers in Prymnesium parvum

    DEFF Research Database (Denmark)

    Rasmussen, Silas Anselm; Meier, Sebastian; Andersen, Nikolaj Gedsted

    2016-01-01

    Blooms of the microalga Prymnesium parvum cause devastating fish kills worldwide, which are suspected to be caused by the supersized ladder-frame polyether toxins prymnesin-1 and -2. These toxins have, however, only been detected from P. parvum in rare cases since they were originally described two...

  10. Measurements of serum-free thyroid hormone concentrations by ultrafiltration

    International Nuclear Information System (INIS)

    Konno, Norimichi; Hagiwara, Kohji; Taguchi, Hideo; Murakami, Shigeki; Taguchi, Shizuko

    1987-01-01

    An ultrafiltration method (UF) for measuring free thyroxine (FT 4 ) and free triiodothyronine (FT 3 ) using the Diaflow YM membrane (Centricon-10) is described. The results are compared with those by equilibrium dialysis (ED) and also by mathematical calculations derived from T 4 , T 3 , and binding protein concentrations. The precision with the UF method was excellent. The normal ranges of FT 4 and FT 3 by the three methods are all comparable. There was a high degree of correlation of FT 4 or FT 3 results by UF with those by ED and by calculation (r = 0.940 - 0.974, n = 161, P 4 and FT 3 by all methods agreed well for hyperthyroidism, hypothyroidism, and for patients with low T 4 -binding globulin. The mean FT 3 in pregnancy was lower than the normal value for all methods, and FT 4 concentrations by UF and calculation also decreased in late pregnancy. The mean FT 4 by UF and ED in low T 3 syndrome were significantly higher than in the normal controls, while the calculated FT 4 was lower. The FT 3 in low T 3 syndrome distributed normal to subnormal in all methods. These results indicate that a) the UF method is a reliable reference method for measuring FT 4 and FT 3 concentrations; b) the UF results agree well with those by ED and also with theoretically derived values in subjects with thyroid diseases and TBG abnormalities; c) for patients with low T 3 syndrome, the FT 4 results obtained by UF and ED are similarly discrepant from the calculated results, implying the existence of binding inhibitor(s) which affect both UF and ED measurements. (author)

  11. assessment of Seawater Intrusion in Concrete by Measuring Chlorine Concentration

    International Nuclear Information System (INIS)

    Abdel-Monem, A.M.; Kansouh, W.A.; Osman, A.M.; Bashter, I.I.

    2011-01-01

    The object of this work is to measure water intrusion in concrete using a new methodology based on neutron activation technique. The applied method depends on measuring the activated gamma energy lines emitted from 38 Cl using a gamma spectrometer with Ge(Li) and HPGe detectors. Concrete samples with different percentages of silica fume (SF), up to 20 % submerged in seawater for different period of time were used to perform the investigation. Samples of concrete taken from different positions along the direction of water intrusion in concrete block were irradiated by thermal neutrons using the irradiation cell of 252 Cf neutron source and one of the vertical channels of search reactor at Delft University. The measured 38 Cl concentrations of the irradiated samples were used to plot groups of water profiles distribution in concrete samples with different SF % and submerged in seawater for different periods. These profiles were compared with the others which use here measured by neutron back emitted method where a satisfactory agreement was observed between the two. Further, the displayed measured results; show that the diffusivity for all water contents decreases with increasing the silica fume percentage up to 15 %. However, for concrete samples with silica fume 20 % the observed phenomenon is reversed due to the deterioration of concrete physical and mechanical properties

  12. Si-Traceable Scale for Measurements of Radiocarbon Concentration

    Science.gov (United States)

    Hodges, Joseph T.; Fleisher, Adam J.; Liu, Qingnan; Long, David A.

    2017-06-01

    Radiocarbon (^{14}C) dating of organic materials is based on measuring the ^{14}C/^{12}C atomic fraction relative to the nascent value that existed when the material was formed by photosynthetic conversion of carbon dioxide present in the atmosphere. This field of measurement has numerous applications including source apportionment of anthropogenic and biogenic fuels and combustion emissions, carbon cycle dynamics, archaeology, and forensics. Accelerator mass spectrometry (AMS) is the most widely used method for radiocarbon detection because it can measure extremely small amounts of radiocarbon (background of nominally 1.2 parts-per-trillion) with high relative precision (0.4 %). AMS measurements of radiocarbon are typically calibrated by reference to standard oxalic-acid (C_2H_2O_4) samples of known radiocativity that are derived from plant matter. Specifically, the internationally accepted absolute dating reference for so-called "modern-equivalent" radiocarbon is 95 % of the specific radioactivity in AD 1950 of the National Bureau of Standards (NBS) oxalic acid standard reference material and normalized to δ^{13}C_{VPDB} = 19 per mil. With this definition, a "modern-equivalent" corresponds to 1.176(70) parts-per-trillion of ^{14}C relative to total carbon content. As an alternative radiocarbon scale, we propose an SI-traceable method to determine ^{14}C absolute concentration which is based on linear Beer-Lambert-law absorption measurements of selected ^{14}C^{16}O_2 ν_3-band line areas. This approach is attractive because line intensities of chosen radiocarbon dioxide transitions can be determined by ab initio calculations with relative uncertainties below 0.5 %. This assumption is justified by the excellent agreement between theoretical values of line intensities and measurements for stable isotopologues of CO_2. In the case of cavity ring-down spectroscopy (CRDS) measurements of ^{14}C^{16}O_2 peak areas, we show that absolute, SI-traceable concentrations of

  13. Measurements of thoron and radon progeny concentrations in Beijing, China

    International Nuclear Information System (INIS)

    Zhang Lei; Liu Cuihong; Guo Qiuju

    2008-01-01

    It has been reported that thoron levels in China are above the world average and may therefore make a significant contribution to the natural background radiation dose. We therefore conducted a pilot study of concentrations of both thoron and radon progeny during the spring of 2006 in the Beijing area, China. A new type of portable 24 h integrating monitor with a CR-39 detector was used during the survey. Seventy dwellings and eight outdoor sites were measured during the survey. For country houses built of red bricks and slurry, the average equilibrium equivalent concentrations (EEC) of thoron and radon were 1.02 ± 0.48 and 16.41 ± 9.02 Bq m -3 , respectively, whereas for city dwellings built of cement blocks and floor slabs, the results were 0.48 ± 0.47 and 11.50 ± 6.99 Bq m -3 for thoron and radon, respectively. For outdoor air, concentrations of thoron and radon progeny were 0.29 ± 0.28 and 7.05 ± 2.68 Bq m -3 , respectively. Radiation exposures from thoron and radon progeny were also evaluated; the ratio of dose contribution from thoron progeny to that of radon progeny was evaluated to be 28% and 17% in country houses and city dwellings, respectively. (note)

  14. Measurements of indoor 222Rn concentration in two art galleries

    International Nuclear Information System (INIS)

    Carneiro, Luana Gomes; Braz, Delson; Jesus, Edgar Francisco de; Cunha, Kenya Dias da; Medeiros, Geiza; Zouain, Felipe; Pitassi, Gabriel; Leite, Carlos Barros; Cardoso, Katia

    2009-01-01

    It is point out that radon and their decay products in environment give high dose to human lung. Studies indicate that the indoor radon inhalation by humans has been considered probably the second most important cause of lung cancer after of smoking. A passive-type radon detector was used for measuring indoor radon concentration in two art galleries at Rio de Janeiro city during 90 days January to March, 2009. The aim of this study is to evaluate the occupational and public radon exposure in art galleries and museums. This paper shows the preliminary results of samples collected at two art galleries located in Gavea, Rio de Janeiro city. 30 LEXAN (GE) track detectors were exposed in the air (indoor as well as outdoor). The samples were collected in the same building which is a construction of XIX century. The analysis of the results suggests that the 222 Rn concentration levels are different in both sampling site, in closed environmental, demonstrating that, although the construction materials are the same the absence of circulating air is a factor very important to increase the concentration of indoor Rn. (author)

  15. Incorporation monitoring by measurements of activity concentrations in air

    International Nuclear Information System (INIS)

    Breukelmann, G.; Dalheimer, A.; Dilger, H.; Henrichs, K.

    1997-01-01

    The incorporation monitoring of workers handling actinides is in many cases not possible by individual methods: The sensitivity of bioassay of methods (in vivo, in vitro) is not sufficient to detect amounts as required by the low annual limits of intake. Similar difficulties may occur with the use of radionuclides with very short physical half-lives. In these cases, the measuring of activity concentrations in the air is the only way to monitor the workers and to meet legal requirements. The essential problem connected with this approach is to make sure, that the air sample analyzed represents the average air inhaled actually. Correspondingly, the new system regulating the incorporation monitoring in Germany requires additional measures to ensure this representatively. (author)

  16. Sulfonated poly(ether sulfone)s containing pyridine moiety for PEMFC.

    Science.gov (United States)

    Jang, Hohyoun; Islam, Md Monirul; Lim, Youngdon; Hossain, Md Awlad; Cho, Younggil; Joo, Hyunho; Kim, Whangi; Jeon, Heung-Seok

    2014-10-01

    Sulfonated poly(ether sulfone)s with varied degree of sulfonation (DS) were prepared via post-sulfonation of synthesized pyridine based poly(ether sulfone) (PPES) using concentrated sulfuric acid as sulfonating agent. The DS was varied with different mole ratio of 4,4'-(2,2-diphenylethenylidene)diphenol, DHTPE in the polymer unit. PPES copolymers were synthesized by direct polycondensation of pyridine unit with bis-(4-fluorophenyl)-sulfone, 4, 4'-sulfonyldiphenol and DHTPE. The structure of the resulting PPES copolymer membranes with different sulfonated units were studied by 1H NMR spectroscopy and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymer with water. The ion exchange capacity (IEC) and proton conductivity were evaluated according to the increase of DS. The water uptake (WU) of the resulting membranes was in the range of 17-58%, compared to that of Nafion 211 28%. The membranes provided proton conductivities of 65-95 mS/cm in contrast to 103 mS/cm of Nafion 211.

  17. Optimization of the transport and mechanical properties of polysiloxane/polyether hybrid polymer electrolytes

    International Nuclear Information System (INIS)

    Boaretto, Nicola; Horn, Theresa; Popall, Michael; Sextl, Gerhard

    2017-01-01

    In this study, the thermo-mechanical properties of networked, polysiloxane/polyether-based, hybrid polymer electrolytes are optimized with the aim of enabling room-temperature operation in lithium metal-polymer batteries. The structural parameters of the electrolytes (polyether chain length, cross-linking and salt concentration) are varied in order to get the best tradeoff between conductivity and mechanical stability. The optimized material has a conductivity close to 1.5·10 −4 S cm −1 at room temperature and a shear storage modulus of 50 kPa up to 100 °C. The effect of TiO 2 nano-particles is also studied with the results showing an overall ambiguous effect on the materials properties. Finally, one of the materials with the highest conductivity is used as electrolyte in a Li/LiFePO 4 cell. This cell has good rate capability and cyclability due to the high conductivity of the electrolyte. However, the high conductivity is reached at expense of the mechanical stability and the resulting electrolyte proves to be too weak to work as an efficient barrier against lithium dendrite growth.

  18. Evaluation of the Efficacy of Different Mixing Techniques and Disinfection on Microbial Colonization of Polyether Impression Materials: A Comparative Study.

    Science.gov (United States)

    Singla, Youginder; Pachar, Renu B; Poriya, Sangeeta; Mishra, Aalok; Sharma, Rajni; Garg, Anshu

    2018-03-01

    This study aims to determine the role of mixing techniques of polyether impression materials and efficacy of disinfection on microbial colonization of these impression materials. Polyether impression material was mixed using two methods: First by hand mixing (group I) and second using an automixer (group II) with a total of 100 samples. Four microbial strains were studied, which included Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. After incubation, the bacterial colonies were counted, and then, disinfectant solution was applied. The effect of disinfection solution was evaluated for each specimen. The surface of polyether impression materials mixed with an automixer has less number of voids and overall a smoother surface as compared with the hand-mixed ones. On comparing the disinfection procedures, i.e., specimens without any disinfection and specimens after disinfection, statistically highly significant difference was seen between all the groups. We can conclude that impression mixing procedures are important in determining the surface characteristics of the impression and ultimately the colonization of bacteria and also determine the importance of disinfection on microbial colonization. This study emphasises the deleterious role of nosocomial infections and specific measures that should be taken regarding the prevention of such diseases. Dental impressions are proved to be a source of such infections and may lead to transmission of such diseases. Thus, proper measures should be taken right from the first step of impression taking to minimizing and preventing such kind of contaminations in clinical practice.

  19. Measurement limits to 134Cs concentration in soil

    International Nuclear Information System (INIS)

    Ahn, J.K.; Kim, J.S.; Lee, H.M.; Kim, H.; Kim, T.H.; Park, J.N.; Kang, Y.S.; Lee, H.S.; Kim, S.J.; Park, J.Y.; Ryu, S.Y.; Kim, H.-Ch.; Kang, W.G.; Kim, S.K.

    2011-01-01

    We investigate the caesium concentrations in soils in mountain areas near Gori nuclear power plant in Korea, focusing on the measurement limits to the 134 Cs. In order to lower the minimum detectable amount (MDA) of activity for the 134 Cs, we have used the ammonium molybdophosphate (AMP) precipitation method to get rid of the 40 K existing in natural radioactivity, which reduces the MDA activity about 10 times smaller than those without the AMP precipitation method. The MDA results for the 134 Cs were found to be in the range between 0.015 and 0.044 Bq/kg-dry weight. In order to diminish the background, we also have measured a part of the soil samples in Yangyang, a small town in the east coast of Korea. However, it turns out that in order to detect the 134 Cs in the samples the MDA should be reduced to the level of mBq/kg-dry weight. - Highlights: → We study the caesium concentrations in soils in mountain areas near Gori NPT in Korea. → We use the AMP precipitation method to lower the minimum detectable amount (MDA) of activity for the 134 Cs. → The results of the MDA for the 134 Cs turn out to be in the range between 0.015 and 0.044. → In order to detect the 134 Cs in the samples, the MDA should be reduced to the level of mBq/kg-dry weight.

  20. Measuring the energy security implications of fossil fuel resource concentration

    International Nuclear Information System (INIS)

    Lefevre, Nicolas

    2010-01-01

    Economic assessments of the welfare effects of energy insecurity are typically uncertain and fail to provide clear guidance to policy makers. As a result, governments have had little analytical support to complement expert judgment in the assessment of energy security. This is likely to be inadequate when considering multiple policy goals, and in particular the intersections between energy security and climate change mitigation policies. This paper presents an alternative approach which focuses on gauging the causes of energy insecurity as a way to assist policy making. The paper focuses on the energy security implications of fossil fuel resource concentration and distinguishes between the price and physical availability components of energy insecurity. It defines two separate indexes: the energy security price index (ESPI), based on the measure of market concentration in competitive fossil fuel markets, and the energy security physical availability index (ESPAI), based on the measure of supply flexibility in regulated markets. The paper illustrates the application of ESPI and ESPAI with two case studies-France and the United Kingdom-looking at the evolution of both indexes to 2030.

  1. Measuring the energy security implications of fossil fuel resource concentration

    Energy Technology Data Exchange (ETDEWEB)

    Lefevre, Nicolas [Woodrow Wilson School of Public and International Affairs, Princeton University, New Jersey (United States)

    2010-04-15

    Economic assessments of the welfare effects of energy insecurity are typically uncertain and fail to provide clear guidance to policy makers. As a result, governments have had little analytical support to complement expert judgment in the assessment of energy security. This is likely to be inadequate when considering multiple policy goals, and in particular the intersections between energy security and climate change mitigation policies. This paper presents an alternative approach which focuses on gauging the causes of energy insecurity as a way to assist policy making. The paper focuses on the energy security implications of fossil fuel resource concentration and distinguishes between the price and physical availability components of energy insecurity. It defines two separate indexes: the energy security price index (ESPI), based on the measure of market concentration in competitive fossil fuel markets, and the energy security physical availability index (ESPAI), based on the measure of supply flexibility in regulated markets. The paper illustrates the application of ESPI and ESPAI with two case studies - France and the United Kingdom - looking at the evolution of both indexes to 2030. (author)

  2. Radioactivity concentration measuring device for radiation waste containing vessel

    International Nuclear Information System (INIS)

    Goto, Tetsuo.

    1994-01-01

    The device of the present invention can precisely and accurately measure a radioactive concentration of radioactive wastes irrespective of the radioactivity concentration distribution. Namely, a Ge detector having a collimator and a plurality of radiation detectors are placed at the outside of the radioactive waste containing vessel in such a way that it can rotate and move vertically relative to the vessel. The plurality of radiation detectors detect radiation coefficient signals at an assumed segment unit of a predetermined length in vertical direction and for every predetermined angle unit in the rotational direction. A weight measuring device determines the weight of the vessel. A computer calculates an average density of radioactivity for the region filled with radioactivity based on the determined net weight and radiation coefficient signals assuming that the volume of the radioactivity is constant. In addition, the computer calculates the amount of radioactivity in the assumed segment by conducting γ -ray absorption compensation calculation for the material in the vessel. Each of the amount of radioactivity is integrated to determine the amount of radioactivity in the vessel. (I.S.)

  3. Tracking and shape errors measurement of concentrating heliostats

    Science.gov (United States)

    Coquand, Mathieu; Caliot, Cyril; Hénault, François

    2017-09-01

    In solar tower power plants, factors such as tracking accuracy, facets misalignment and surface shape errors of concentrating heliostats are of prime importance on the efficiency of the system. At industrial scale, one critical issue is the time and effort required to adjust the different mirrors of the faceted heliostats, which could take several months using current techniques. Thus, methods enabling quick adjustment of a field with a huge number of heliostats are essential for the rise of solar tower technology. In this communication is described a new method for heliostat characterization that makes use of four cameras located near the solar receiver and simultaneously recording images of the sun reflected by the optical surfaces. From knowledge of a measured sun profile, data processing of the acquired images allows reconstructing the slope and shape errors of the heliostats, including tracking and canting errors. The mathematical basis of this shape reconstruction process is explained comprehensively. Numerical simulations demonstrate that the measurement accuracy of this "backward-gazing method" is compliant with the requirements of solar concentrating optics. Finally, we present our first experimental results obtained at the THEMIS experimental solar tower plant in Targasonne, France.

  4. The importance of orientation in proton transport of a polymer film based on an oriented self-organized columnar liquid-crystalline polyether

    Energy Technology Data Exchange (ETDEWEB)

    Tylkowski, Bartosz; Castelao, Nuria [Departament d' Enginyeria Quimica, Universitat Rovira i Virgili, Av. Paiesos Catalans, 26, E-43007, Tarragona (Spain); Giamberini, Marta, E-mail: marta.giamberini@urv.net [Departament d' Enginyeria Quimica, Universitat Rovira i Virgili, Av. Paiesos Catalans, 26, E-43007, Tarragona (Spain); Garcia-Valls, Ricard [Departament d' Enginyeria Quimica, Universitat Rovira i Virgili, Av. Paiesos Catalans, 26, E-43007, Tarragona (Spain); Reina, Jose Antonio [Departament de Quimica Analitica i Quimica Organica, Universitat Rovira i Virgili, Carrer Marcel.li Domingo s/n, E-43007, Tarragona (Spain); Gumi, Tania [Departament d' Enginyeria Quimica, Universitat Rovira i Virgili, Av. Paiesos Catalans, 26, E-43007, Tarragona (Spain)

    2012-02-01

    We prepared membranes based on a liquid-crystalline side-chain polyether obtained by chemical modification of commercial poly(epichlorohydrin) (PECH) with dendrons. This polymer exhibited a columnar structure, which could form an ion channel in the inner part. The columns were successfully oriented by taking advantage of surface interactions between the polymer and hydrophilic substrates, as confirmed by X-ray diffraction analysis (XRD), environmental scanning electron microscopy (ESEM) and optical microscopy between crossed polars (POM). Column orientation was found to be crucial for effective transport: the oriented membranes exhibited proton transport comparable to that of Nafion Registered-Sign N117 and no water uptake. An increase in sodium ion concentration in the feed phase suggested a proton/cation antiport. On the contrary, no proton transport was detected on unoriented membranes based on the same liquid-crystalline side-chain polyether or on unmodified PECH. - Highlights: Black-Right-Pointing-Pointer We prepared oriented membranes based on a liquid crystalline columnar polyether. Black-Right-Pointing-Pointer In this structure, the inner polyether chain could work as an ion channel. Black-Right-Pointing-Pointer We obtained membranes by casting a chloroform solution in the presence of water. Black-Right-Pointing-Pointer Membranes showed good proton permeability due to the presence of oriented channels.

  5. The importance of orientation in proton transport of a polymer film based on an oriented self-organized columnar liquid-crystalline polyether

    International Nuclear Information System (INIS)

    Tylkowski, Bartosz; Castelao, Nuria; Giamberini, Marta; Garcia-Valls, Ricard; Reina, José Antonio; Gumí, Tània

    2012-01-01

    We prepared membranes based on a liquid-crystalline side-chain polyether obtained by chemical modification of commercial poly(epichlorohydrin) (PECH) with dendrons. This polymer exhibited a columnar structure, which could form an ion channel in the inner part. The columns were successfully oriented by taking advantage of surface interactions between the polymer and hydrophilic substrates, as confirmed by X-ray diffraction analysis (XRD), environmental scanning electron microscopy (ESEM) and optical microscopy between crossed polars (POM). Column orientation was found to be crucial for effective transport: the oriented membranes exhibited proton transport comparable to that of Nafion® N117 and no water uptake. An increase in sodium ion concentration in the feed phase suggested a proton/cation antiport. On the contrary, no proton transport was detected on unoriented membranes based on the same liquid-crystalline side-chain polyether or on unmodified PECH. - Highlights: ► We prepared oriented membranes based on a liquid crystalline columnar polyether. ► In this structure, the inner polyether chain could work as an ion channel. ► We obtained membranes by casting a chloroform solution in the presence of water. ► Membranes showed good proton permeability due to the presence of oriented channels.

  6. The Influence of Operation Temperature of the Characteristic of Sulfonated Polyether-Ether Ketone Electrolyte Membrane

    International Nuclear Information System (INIS)

    Sri Handayani; Eniya Listiani Dewi

    2008-01-01

    Recently, high temperature Direct Methanol Fuel Cell (DMFC) has been receiving great attention, because provide faster reaction kinetic, the enhance electrode kinetics, reduced size and reduce Pt-based catalyst poisoning by CO. But at high temperature, it will decrease the membrane performance i.e. low proton conductivity affected by humidification and high methanol crossover as happening to Nafion-117 membrane (commercial membrane). To solve this problems, sulfonated polyether-ether ketone and composite (silica additive) as electrolyte membrane at high temperature DMFC was tried to use. In this research, sPEEK with sulfonation degree (SD) 47 % and 68 % and addition silica 3 wt % were used as electrolyte membranes. Proton conductivity and methanol permeability of these membranes were measured at various temperatures (25, 50, 90 and 140 C ). Proton conductivity of membranes were measured by standard bridge impedance spectroscopy (LCR-meter, HIOKI 3522-50) and it was found about 0.01-0.04 S/cm. Methanol permeability of membranes were investigated by diffusion cell and gave the result about 10 - 6 - 10 - 7cm 2 /s. The best sPEEK membrane was sPEEK membrane with SD 68 % and the addition of silica 3 wt%, signed by highest selectivity value (ratio proton conductivity to methanol permeability). Therefore, electrolyte membrane based sulfonated polyether-ether ketone (SD 68 %) with silica could be used at high temperature which give promising as solid electrolyte membrane in application high temperature DMFC. (author)

  7. Laboratory Measurements of Particulate Matter Concentrations from Asphalt Pavement Abrasion

    Directory of Open Access Journals (Sweden)

    Fullová Daša

    2016-12-01

    Full Text Available The issue of emissions from road traffic is compounded by the fact that the number of vehicles and driven kilometres increase each year. Road traffic is one of the main sources of particulate matter and traffic volume is still increasing and has unpleasant impact on longevity of the pavements and the environment. Vehicle motions cause mechanical wearing of the asphalt pavement surface - wearing course by vehicle tyres. The contribution deals with abrasion of bituminous wearing courses of pavements. The asphalt mixtures of wearing courses are compared in terms of mechanically separated particulate matter. The samples of asphalt mixtures were rutted in wheel tracking machine. The particulate matter measurements were performed in laboratory conditions. The experimental laboratory measurements make it possible to sample particulates without contamination from exhaust emissions, abraded particles from vehicles, resuspension of road dust and climate affects. The contribution offers partial results of measurements on six trial samples of asphalt mixtures with different composition. It presents particulate matter morphology and the comparison of rutted asphalt samples in terms of PM mass concentrations and chemical composition.

  8. Effects of atomic oxygen irradiation on the surface properties of phenolphthalein poly(ether sulfone)

    International Nuclear Information System (INIS)

    Pei Xianqiang; Li Yan; Wang Qihua; Sun Xiaojun

    2009-01-01

    To study the effects of low earth orbit environment on the surface properties of polymers, phenolphthalein poly(ether sulfone) (PES-C) blocks were irradiated by atomic oxygen in a ground-based simulation system. The surface properties of the pristine and irradiated blocks were studied by attenuated total-reflection FTIR (FTIR-ATR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM). It was found that atomic oxygen irradiation induced the destruction of PES-C molecular chains, including the scission and oxidation of PES-C molecular chains, as evidenced by FTIR and XPS results. The scission of PES-C molecular chains decreased the relative concentration of C in the surface, while the oxidation increased the relative concentration of O in the surface. The changes in surface chemical structure and composition also changed the surface morphology of the block, which shifted from smooth structure before irradiation to 'carpet-like' structure after irradiation

  9. Measurement of PCB concentrations in waters using a biomonitoring programme

    International Nuclear Information System (INIS)

    Mast, P.G.

    1993-01-01

    The book describes a PCB biomonitoring programme which was developed for measuring instantaneous PCB concentrations and permits the compilation of PCB action cadastres for different types of waters and subsequent derivation of current trends. Six representative congeners were selected as a basis for the quantitative routine analysis. The fish species bream (abramis brama) and roach (rutilus rutilus) were used as indicators in the PCB biomonitoring programme on account of their distribution and ecological demands. The age and growth rate of each fish destined for analysis was determined so as to ensure that only healthy fish would be used. In both fish species the dorsal musulature with its low scatter of test results and consistent PCB pattern (internal quantification) proved a representative body region. (orig.) [de

  10. Measurement of interstitial cetirizine concentrations in human skin

    DEFF Research Database (Denmark)

    Petersen, Lars Jelstrup; Church, M K; Rihoux, J P

    1999-01-01

    BACKGROUND: The purpose of the present study was to measure the concentrations of cetirizine in the extracellular water compartment in intact human skin and assess simultaneously inhibition of histamine-induced wheal and flare reactions. METHODS: Skin cetirizine levels were collected...... by the microdialysis technique and analyzed by high-pressure liquid chromatography with mass spectrometry detection. Skin levels in 20 subjects were compared to plasma levels for 4 h after a single oral dose of 10 or 20 mg of cetirizine. Skin prick tests were performed with histamine 100 mg/ml. RESULTS: Plasma...... cetirizine levels increased within 30 min to reach peak values of 315+/-10 and 786+/-45 ng/ml 90-120 min after administration of 10 and 20 mg of cetirizine. This was followed by a slow decline. In the skin, dialysate cetirizine levels (non-protein-bound fraction only) peaked at 1.6+/-0.1 and 2.4+/-0.3 ng...

  11. An Alpha spectrometer for measuring radon daughter individual activity concentration

    International Nuclear Information System (INIS)

    Berico, M.; Formignani, M.; Mariotti, F.

    2001-01-01

    In the frame of the program of the Institute for Radiation Protection of ENEA, related to the evaluation of dose from radon and thoron progeny, an alpha spectrometer for the continuous air monitoring (CAM type) of radon and thoron has been realized. The constructive characteristics of the device are here presented together with energy and efficiency calibration. The device allows, by means of a screen type diffusion battery and a filter, to determinate the single radioactivity of each radionuclide of the progeny selecting them in relation to their diffusive behaviour (dichotomous particle size selection). The three-count filter method has been employed to measure the concentrations of 218 Po, 214 Pb and 214 Bi in air. Radon and thoron effective doses using a dosimetric, instead of an epidemiologic approach, will be then evaluated [it

  12. Genetic screening strategy for rapid access to polyether ionophore producers and products in actinomycetes.

    Science.gov (United States)

    Wang, Hao; Liu, Ning; Xi, Lijun; Rong, Xiaoying; Ruan, Jisheng; Huang, Ying

    2011-05-01

    Polyether ionophores are a unique class of polyketides with broad-spectrum activity and outstanding potency for the control of drug-resistant bacteria and parasites, and they are produced exclusively by actinomycetes. A special epoxidase gene encoding a critical tailoring enzyme involved in the biosynthesis of these compounds has been found in all five of the complete gene clusters of polyether ionophores published so far. To detect potential producer strains of these antibiotics, a pair of degenerate primers was designed according to the conserved regions of the five known polyether epoxidases. A total of 44 putative polyether epoxidase gene-positive strains were obtained by the PCR-based screening of 1,068 actinomycetes isolated from eight different habitats and 236 reference strains encompassing eight major families of Actinomycetales. The isolates spanned a wide taxonomic diversity based on 16S rRNA gene analysis, and actinomycetes isolated from acidic soils seemed to be a promising source of polyether ionophores. Four genera were detected to contain putative polyether epoxidases, including Micromonospora, which has not previously been reported to produce polyether ionophores. The designed primers also detected putative epoxidase genes from diverse known producer strains that produce polyether ionophores unrelated to the five published gene clusters. Moreover, phylogenetic and chemical analyses showed a strong correlation between the sequence of polyether epoxidases and the structure of encoded polyethers. Thirteen positive isolates were proven to be polyether ionophore producers as expected, and two new analogues were found. These results demonstrate the feasibility of using this epoxidase gene screening strategy to aid the rapid identification of known products and the discovery of unknown polyethers in actinomycetes.

  13. Genetic Screening Strategy for Rapid Access to Polyether Ionophore Producers and Products in Actinomycetes ▿ †

    Science.gov (United States)

    Wang, Hao; Liu, Ning; Xi, Lijun; Rong, Xiaoying; Ruan, Jisheng; Huang, Ying

    2011-01-01

    Polyether ionophores are a unique class of polyketides with broad-spectrum activity and outstanding potency for the control of drug-resistant bacteria and parasites, and they are produced exclusively by actinomycetes. A special epoxidase gene encoding a critical tailoring enzyme involved in the biosynthesis of these compounds has been found in all five of the complete gene clusters of polyether ionophores published so far. To detect potential producer strains of these antibiotics, a pair of degenerate primers was designed according to the conserved regions of the five known polyether epoxidases. A total of 44 putative polyether epoxidase gene-positive strains were obtained by the PCR-based screening of 1,068 actinomycetes isolated from eight different habitats and 236 reference strains encompassing eight major families of Actinomycetales. The isolates spanned a wide taxonomic diversity based on 16S rRNA gene analysis, and actinomycetes isolated from acidic soils seemed to be a promising source of polyether ionophores. Four genera were detected to contain putative polyether epoxidases, including Micromonospora, which has not previously been reported to produce polyether ionophores. The designed primers also detected putative epoxidase genes from diverse known producer strains that produce polyether ionophores unrelated to the five published gene clusters. Moreover, phylogenetic and chemical analyses showed a strong correlation between the sequence of polyether epoxidases and the structure of encoded polyethers. Thirteen positive isolates were proven to be polyether ionophore producers as expected, and two new analogues were found. These results demonstrate the feasibility of using this epoxidase gene screening strategy to aid the rapid identification of known products and the discovery of unknown polyethers in actinomycetes. PMID:21421776

  14. Silane Cross-Linked Sulfonted Poly(Ether Ketone/Ether Benzimidazoles for Fuel Cell Applications

    Directory of Open Access Journals (Sweden)

    Zilu Yao

    2017-11-01

    Full Text Available γ-(2,3-epoxypropoxy propyltrimethoxysilane (KH-560 was incorporated in various proportions into side-chain-type sulfonated poly(ether ketone/ether benzimidazole (SPEKEBI as a crosslinker, to make membranes with high ion exchange capacities and excellent performance for direct methanol fuel cells (DMFCs. Systematical measurements including Fourier transform infrared (FT-IR, scanning electron microscopy-energy-dispersive and X-ray photoelectron spectroscopy (XPS proved the complete disappearance of epoxy groups in KH-560 and the existence of Si in the membranes. The resulting membranes showed increased mechanical strength and thermal stability compared to the unmodified sulfonated poly(ether ketone/ether benzimidazole membrane in appropriate doping amount. Meanwhile, the methanol permeability has decreased, leading to the increase of relative selectivities of SPEKEBI-x-SiO2 membranes. Furthermore, the H2/O2 cell performance of SPEKEBI-2.5-SiO2 membrane showed a much higher peak power density compared with the pure SPEKEBI memrbrane.

  15. Parasite infection accelerates age polyethism in young honey bees

    DEFF Research Database (Denmark)

    Lecocq, Antoine; Jensen, Annette Bruun; Kryger, Per

    2016-01-01

    micro-colonies of honey bees and video analyses to track the effects of N. ceranae infection and exposure on a range of individual and social behaviours in young adult bees. We provide detailed data showing that N. ceranae infection significantly accelerated the age polyethism of young bees, causing......Honey bees (Apis mellifera) are important pollinators and their health is threatened worldwide by persistent exposure to a wide range of factors including pesticides, poor nutrition, and pathogens. Nosema ceranae is a ubiquitous microsporidian associated with high colony mortality. We used lab...... manipulation to increase colony infection. However, reduction in queen contacts could help bees limit the spread of infection. Such accelerated age polyethism may provide a form of behavioural immunity, particularly if it is elicited by a wide variety of pathogens....

  16. High Resolution Mass Spectrometry of Polyfluorinated Polyether-Based Formulation

    DEFF Research Database (Denmark)

    Dimzon, Ian Ken; Trier, Xenia; Frömel, Tobias

    2016-01-01

    High resolution mass spectrometry (HRMS) was successfully applied to elucidate the structure of a polyfluorinated polyether (PFPE)-based formulation. The mass spectrum generated from direct injection into the MS was examined by identifying the different repeating units manually and with the aid o......-fluorinated polymers. The information from MS is essential in studying the physico-chemical properties of PFPEs and can help in assessing the risks they pose to the environment and to human health. Graphical Abstract ᅟ....

  17. Study of domain structure in segmented polyether polyurethaneureas by PAT

    International Nuclear Information System (INIS)

    Yin Chuanyuan; Xu Weizheng; Gu Qingchao

    1990-01-01

    The domain structure of segmented polyether polyurethaneureas is investigated by means of positron annihilation technique, small angle X-ray scattering and differential scanning calorimetry. The experimental results show that the decrease of domain volume and free volume results from the increase of hard segment contents, and that the increase of domain volume and free volume results from the increase of molecular weight of soft segments

  18. Comparative study to evaluate the accuracy of polyether occlusal bite registration material and occlusal registration wax as a guide for occlusal reduction during tooth preparation.

    Science.gov (United States)

    Joshi, Niranjan; Shetty, Sridhar N; Prasad, Krishna D

    2013-01-01

    The use of different materials and techniques has been studied to decide the safest quantum of reduction of the occlusal surfaces. However, these methods provide limited information as to the actual amount of reduction with limitations in accuracy, accessibility and complexity. The objective of this study was to compare and evaluate the reliability of the most commonly used occlusal registration wax that with polyether bite registration material as a guide for occlusal reduction required during tooth preparations. For the purpose of this study, 25 abutment teeth requiring tooth preparation for fixed prosthesis were selected and tooth preparations carried out. Modeling wax strips of specific dimensions were placed onto the cast of prepared tooth, which was mounted on maximum intercuspation on the articulator and the articulator was closed. The thickness of the wax registration was measured at three zones namely two functional cusps and central fossa. Similar measurements were made using the polyether bite registration material and prosthesis at the same zones. The data was tabulated and was subjected to statistical analysis using anova test and Tukey honestly significant difference test. The differences in thickness between wax record and prosthesis by 0.1346 mm, whereas the difference between polyether and prosthesis was 0.02 mm with a P value of 0.042, which is statistically significant. This means that the wax record was 8.25% larger than the prosthesis while polyether was just 1.27% larger than the prosthesis. The clinical significance of the above analysis is that Ramitec polyether bite registration material is most suitable material when compared with commonly used modeling wax during the tooth preparation.

  19. Development of Cutaneous Bioadhesive Ureasil-Polyether Hybrid Films

    Directory of Open Access Journals (Sweden)

    João Augusto Oshiro Junior

    2015-01-01

    Full Text Available The hydrolysis and condensation reactions involved in synthesis of ureasil-polyether films influence the film formation time and the number of chemical groups able to form hydrogen bonds, responsible for the bioadhesion, with the biological substrate. The objective of this work was to study the influence of the use of an acid catalyst (hydrochloric acid and a basic catalyst (ammonium fluoride in the hydrolysis and condensation reactions on the time formation and bioadhesion of ureasil-polyether films. The toxicity of the films was evaluated. The MTT assay has shown cell viability of human skin keratinocytes higher than 70% of all analyzed materials suggesting low cytotoxicity. The bioadhesion of the films is strongly dependent on the viscosity and hydrophilic/hydrophobic balance of the polyether chains used to synthetize the hybrid molecules. The use of acid catalyst promotes the formation of less viscous films with higher bioadhesion. The hybrids formed by more hydrophilic PEO chains are more bioadherent, since they can interact more efficiently with the water present in the stratum corneum increasing the bioadhesion. Due to their low toxicity and high bioadhesion, the ureasil-PEO films obtained by using HCl as catalyst agent are good candidates for application to the skin as bioadhesive films.

  20. Transcutaneous Measurement of Blood Analyte Concentration Using Raman Spectroscopy

    Science.gov (United States)

    Barman, Ishan; Singh, Gajendra P.; Dasari, Ramachandra R.; Feld, Michael S.

    2008-11-01

    Diabetes mellitus is a chronic disorder, affecting nearly 200 million people worldwide. Acute complications, such as hypoglycemia, cardiovascular disease and retinal damage, may occur if the disease is not adequately controlled. As diabetes has no known cure, tight control of glucose levels is critical for the prevention of such complications. Given the necessity for regular monitoring of blood glucose, development of non-invasive glucose detection devices is essential to improve the quality of life in diabetic patients. The commercially available glucose sensors measure the interstitial fluid glucose by electrochemical detection. However, these sensors have severe limitations, primarily related to their invasive nature and lack of stability. This necessitates the development of a truly non-invasive glucose detection technique. NIR Raman Spectroscopy, which combines the substantial penetration depth of NIR light with the excellent chemical specificity of Raman spectroscopy, provides an excellent tool to meet the challenges involved. Additionally, it enables simultaneous determination of multiple blood analytes. Our laboratory has pioneered the use of Raman spectroscopy for blood analytes' detection in biological media. The preliminary success of our non-invasive glucose measurements both in vitro (such as in serum and blood) and in vivo has provided the foundation for the development of feasible clinical systems. However, successful application of this technology still faces a few hurdles, highlighted by the problems of tissue luminescence and selection of appropriate reference concentration. In this article we explore possible avenues to overcome these challenges so that prospective prediction accuracy of blood analytes can be brought to clinically acceptable levels.

  1. Comparison of Properties among Dendritic and Hyperbranched Poly(ether ether ketones and Linear Poly(ether ketones

    Directory of Open Access Journals (Sweden)

    Atsushi Morikawa

    2016-02-01

    Full Text Available Poly(ether ether ketone dendrimers and hyperbranched polymers were prepared from 3,5-dimethoxy-4′-(4-fluorobenzoyldiphenyl ether and 3,5-dihydroxy-4′-(4-fluorobenzoyldiphenyl ether through aromatic nucleophilic substitution reactions. 1-(tert-Butyldimethylsiloxy-3,5-bis(4-fluorobenzoylbenzene was polycondensed with bisphenols, followed by cleavage of the protective group to form linear poly(ether ketones having the same hydroxyl groups in the side chains as the chain ends of the dendrimer and hyperbranched polymers. Their properties, such as solubilities, reduced viscosities, and thermal properties, were compared with one another. Similar comparisons were also carried out among the corresponding methoxy group polymers, and the size of the molecules was shown to affect the properties.

  2. Description and measurement of concentration problems in depressed patients.

    Science.gov (United States)

    Watts, F N; Sharrock, R

    1985-05-01

    Depressed patients commonly complain of concentration problems, yet these have seldom been the focus of systematic investigation. A structured interview about concentration problems was administered to a group of relatively severely depressed patients. Problems in reading and watching television were the most common, and were highly correlated with each other. Direct report of the number of concentration lapses on a reading task was the most generally satisfactory task-performance correlate of complaints of reading/TV concentration problems. Evidence both from this task and from the interview suggests that depressive concentration problems may often be due to 'mind-wandering'. The correlations with concentration problems with the severity and endogeneity of depression and with state anxiety were generally similar.

  3. The Setting Time of Polyether Impression Materials after Contact with Conventional and Experimental Gingival Margin Displacement Agents.

    Science.gov (United States)

    Nowakowska, Danuta; Raszewski, Zbigniew; Ziętek, Marek; Saczko, Jolanta; Kulbacka, Julita; Więckiewicz, Włodzimierz

    2018-02-01

    The compatibility of chemical gingival margin displacement agents with polyether impression materials has not been determined. The aim of this study was to evaluate the setting time of polyether impression elastomers after contact with conventional and experimental gingival displacement agents. The study compared the setting time of two polyether impression materials: medium body (Impregum Penta Soft) and light body (Impregum Garant L DuoSoft) after contact with 10 gingival displacement agents, including 5 conventional astringents (10%, 20%, and 25% aluminum chloride, 25% aluminum sulfate, and 15.5% ferric sulfate) and 5 experimental adrenergics (0.1% and 0.01% HCl-epinephrine, 0.05% HCl-tetrahydrozoline, 0.05% HCl-oxymetazoline, and 10% HCl-phenylephrine). As many as 120 specimens (60 light body and 60 medium body) were mixed with 20 μl of each of 10 gingival displacement agents, and the time to achieve maximum viscosity was measured with a viscometer. The setting times of these specimens were compared with the control group of 12 specimens, which were polymerized without contact with the displacement agents. The experiments were performed in two environments: 23°C and 37°C (± 0.1°C). Individual and average polymerization time compatibility indices (PTCI) were calculated. Data were analyzed by 2-way ANOVA (α = 0.05). The evaluated chemical displacement agents from both groups changed the setting time of light- and medium-body PE. The negative individual PTCI values achieved astringent (20% aluminum chloride) with two PE in both temperature environments. The average PTCI values of the experimental displacement agents at laboratory and intraoral temperatures were significantly higher than the conventional agents. The present findings suggest that experimental retraction agents can be recommended clinically as gingival margin displacement agents with minimal effects on the setting time of medium- and light-body polyether impression materials; however, direct

  4. Nonthmicin, a Polyether Polyketide Bearing a Halogen-Modified Tetronate with Neuroprotective and Antiinvasive Activity from Actinomadura sp.

    Science.gov (United States)

    Igarashi, Yasuhiro; Matsuoka, Noriaki; In, Yasuko; Kataura, Tetsushi; Tashiro, Etsu; Saiki, Ikuo; Sudoh, Yuri; Duangmal, Kannika; Thamchaipenet, Arinthip

    2017-03-17

    Nonthmicin (1), a new polyether polyketide bearing a chlorinated tetronic acid, was isolated from the culture extract of a soil-derived Actinomadura strain. The structure of 1 was elucidated by interpretation of NMR and MS spectroscopic data, and the absolute configuration of 1 was proposed on the basis of the crystal structure of its dechloro congener ecteinamycin (2) also isolated from the same strain. Tetronic acids modified by halogenation have never been reported from natural products. Compounds 1 and 2 were found to have neuroprotective activity and antimetastatic properties at submicromolar concentrations in addition to antibacterial activity.

  5. Measurement of local interfacial area concentration in boiling loop

    International Nuclear Information System (INIS)

    Kyoung, Ho Kang; Byong, Jo Yun; Goon, Cherl Park

    1995-01-01

    An accurate prediction of two-phase flow is essential to many energy systems, including nuclear reactors. To model the two-phase flow, detailed information on the internal flow structure is required. The void fraction and interfacial area concentration are important fundamental parameters characterizing the internal structure of two-phase flow. The interfacial area concentration is defined as the available interfacial area per unit volume of the two-phase mixture in calculations of the interfacial transport of mass, momentum, and energy. Although a number of studies have been made in this area, the interfacial area concentration in two-phase flow has not been sufficiently investigated either experimentally or analytically. Most existing models for interfacial area concentration are limited to area-averaged interfacial area concentration in a flow channel. And the studies on local interfacial area concentration are limited to the case of air-water two-phase flow. However, the internal flow structure of steam-water two-phase flow having various bubble sizes could be quite different from that of air-water two-phase flow, the reliability of which weak in practical applications. In this study, the local interfacial area concentration steam-water two-phase flow has been investigated experimentally in a circular boiling tube having a heating rod in the center, and for the low flow with liquid superficial velocity <1 m/s

  6. Mechanical properties and chemical stability of pivalolactone-based poly(ether ester)s

    NARCIS (Netherlands)

    Tijsma, E.J.; Tijsma, E.J.; van der Does, L.; Bantjes, A.; Bantjes, A.; Vulic, I.

    1994-01-01

    The processing, mechanical and chemical properties of poly(ether ester)s, prepared from pivalolactone (PVL), 1,4-butanediol (4G) and dimethyl terephthalate (DMT), were studied. The poly(ether ester)s could easily be processed by injection moulding, owing to their favourable rheological and thermal

  7. Ionizable polyethers as specific metal ion carriers in liquid-liquid extraction and liquid membrane separations

    International Nuclear Information System (INIS)

    Walkowiak, W.; Charewicz, W.A.; Bartsch, R.A.; Ndip, G.M.

    1988-01-01

    Consideration is given to results of investigations into competitive extraction and penetration through a liquid membrane of alkali and alkaline earth cations from aqueous solutions by a series of lipophilic and ionizable acyclic polyethers of various molecular structure. It is shown that specificity and selectiviy of cation carriers in liquid-liquid extraction and liquid membrane separation depend on molecular structure of acyclic polyethers

  8. Measurements of Radon Concentration in Yemen Using Spark Counter

    International Nuclear Information System (INIS)

    Arafa, W.; Abou-Leila, M.; Hafiz, M.E.; Al-Glal, N.

    2011-01-01

    Spark counter has been designed and realized and the optimum applied voltage was found to be 600 V. Excellent consistent agreements was observed between counted number of tracks by spark counter and reading by optical microscope. Radon concentration in some houses in Sana'a and Hodeidah cities in Yemen had been performed using LR-115 SSNTD and spark counter system. The average radon concentration in both cities was far lower the alert value. The results showed that radon concentration in the metropolitan area Sana'a was higher than that in Hodeidah city. Also, it was observed that old residential houses had higher levels of radon concentrations have compared to newly built houses in the metropolitan area Sana'a

  9. Ionic conduction in polyether-based lithium arylfluorosulfonimide ionic melt electrolytes

    International Nuclear Information System (INIS)

    Herath, Mahesha B.; Creager, Stephen E.; Rajagopal, Rama V.; Geiculescu, Olt E.; DesMarteau, Darryl D.

    2009-01-01

    We report synthesis, characterization and ion transport in polyether-based ionic melt electrolytes consisting of Li salts of low-basicity anions covalently attached to polyether oligomers. Purity of the materials was investigated by HPLC analysis and electrospray ionization mass spectrometry. The highest ionic conductivity of 7.1 x 10 -6 S/cm at 30 deg. C was obtained for the sample consisting of a lithium salt of an arylfluorosulfonimide anion attached to a polyether oligomer with an ethyleneoxide (EO) to lithium ratio of 12. The conductivity order of various ionic melts having different polyether chain lengths suggests that at higher EO:Li ratios the conductivity of the electrolytes at room temperature is determined in part by the amount of crystallization of the polyether portion of the ionic melt.

  10. Comparison of spectroscopically measured tissue alcohol concentration to blood and breath alcohol measurements

    Science.gov (United States)

    Ridder, Trent D.; Ver Steeg, Benjamin J.; Laaksonen, Bentley D.

    2009-09-01

    Alcohol testing is an expanding area of interest due to the impacts of alcohol abuse that extend well beyond drunk driving. However, existing approaches such as blood and urine assays are hampered in some testing environments by biohazard risks. A noninvasive, in vivo spectroscopic technique offers a promising alternative, as no body fluids are required. The purpose of this work is to report the results of a 36-subject clinical study designed to characterize tissue alcohol measured using near-infrared spectroscopy relative to venous blood, capillary blood, and breath alcohol. Comparison of blood and breath alcohol concentrations demonstrated significant differences in alcohol concentration [root mean square of 9.0 to 13.5 mg/dL] that were attributable to both assay accuracy and precision as well as alcohol pharmacokinetics. A first-order kinetic model was used to estimate the contribution of alcohol pharmacokinetics to the differences in concentration observed between the blood, breath, and tissue assays. All pair-wise combinations of alcohol assays were investigated, and the fraction of the alcohol concentration variance explained by pharmacokinetics ranged from 41.0% to 83.5%. Accounting for pharmacokinetic concentration differences, the accuracy and precision of the spectroscopic tissue assay were found to be comparable to those of the blood and breath assays.

  11. Macromolecular Engineering: New Routes Towards the Synthesis of Well-??Defined Polyethers/Polyesters Co/Terpolymers with Different Architectures

    KAUST Repository

    Alamri, Haleema

    2016-05-18

    styrene oxide (SO) monomer has been less investigated than other well-known epoxide monomers. The new one?pot synthesis of polyether?b?polyester block copolymers allowed a high degree of control with respect to the molecular weight and molecular weight distribution. It also eliminates the need for a multi-step process in which the first block must be isolated and purified prior to its subsequent use as a macroinitiator for the second block. It is also worth noting that this approach is based primarily on the use of organocatalyst because this class of block copolymers has greater potential in biomedical and pharmaceutical applications and because organocatalysts are believed to be less toxic than their metallic counterparts. The fourth part of the thesis describes the extension of the scope of the newly developed catalyst?switching approach in the synthesis of different macromolecular architectures, with a special focus on styrene oxide as a monomer, which had not previously been explored either as a linear copolymer with other monomers (except with EO) or with a macromolecular architecture such as block star or mikto arm star. The results detailed in Chapter 4 demonstrate the validity of extending the newly developed strategy to the synthesis of a variety of polymers with different macromolecular architectures. Since organic catalysts (phoshazene bases) have been utilized in this work for the synthesis of polyethers and polyesters with the aim of alleviating the toxic properties associated with metal-based catalysts, it was necessary to investigate the toxicity of this class of organocatalyst since, until now, no evidence has appeared of any attempt to address this issue. The objective of the work presented in the fifth part of this thesis was therefore to assess whether this class of organocatalysts are safe with respect to human health and whether their structure and concentration are dependent on an evaluation of the level of cytotoxicity or on other parameters. Both

  12. Role of post-sulfonation of poly(ether ether sulfone) in proton conductivity and chemical stability of its proton exchange membranes for fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Unveren, Elif Erdal; Erdogan, Tuba; Inan, Tulay Y. [Chemistry Institute, TUBITAK Marmara Research Center, 41470, Gebze, Kocaeli (Turkey); Celebi, Serdar S. [Professor Emeritus, Chemical Engineering Department, Hacettepe University, 06800, Beytepe, Ankara (Turkey)

    2010-04-15

    Commercially available poly(ether ether sulfone), PEES, was directly sulfonated using concentrated sulfuric acid at low temperatures by minimizing degradation during sulfonation. The sulfonation reaction was performed in the temperature range of 5-25 C. Sulfonated polymers were characterized by FTIR, {sup 1}H NMR spectroscopy and ion exchange capacity (IEC) measurements. Degradation during sulfonation was investigated by measuring intrinsic viscosity, glass transition temperature and thermal decomposition temperature of sulfonated polymers. Sulfonated PEES, SPEES, membranes were prepared by solvent casting method and characterized in terms of IEC, proton conductivity and water uptake. The effect of sulfonation conditions on chemical stability of membranes was also investigated via Fenton test. Optimum sulfonation condition was determined to be 10 C with conc. H{sub 2}SO{sub 4} based on the characteristics of sulfonated polymers and also the chemical stability of their membranes. SPEES membranes exhibited proton conductivity up to 185.8 mS cm{sup -1} which is higher than that of Nafion 117 (133.3 mS cm{sup -1}) measured at 80 C and relative humidity 100%. (author)

  13. The Critical Micelle Concentration of Asphaltenes as Measured by Calorimetry

    DEFF Research Database (Denmark)

    Andersen, Simon Ivar; Christensen, S. D.

    2000-01-01

    Micellization of asphaltenes in solution has been investigated using a micro calorimetric titration procedure (Andersen, S. I.; Birdi, K. S. J Colloid Interface Sci. 1991, 142, 497). The method uses the analysis of heat of dissociation and dilution of asphaltene micelles when a pure solvent (or...... solvent mixture) is titrated with a solution of asphaltene in the same solvent. The asphaltene concentration of the injected solution is at a level above the critical micelle concentration (CMC). In the present paper the procedure is applied in investigation of asphaltenes as well as subfractions...

  14. Wear of Spur Gears Having a Dithering Motion and Lubricated with a Perfluorinated Polyether Grease

    Science.gov (United States)

    Krantz, Timothy; Oswald, Fred; Handschuh, Robert

    2007-01-01

    Gear contact surface wear is one of the important failure modes for gear systems. Dedicated experiments are required to enable precise evaluations of gear wear for a particular application. The application of interest for this study required evaluation of wear of gears lubricated with a grade 2 perfluorinated polyether grease and having a dithering (rotation reversal) motion. Experiments were conducted using spur gears made from AISI 9310 steel. Wear was measured using a profilometer at test intervals encompassing 10,000 to 80,000 cycles of dithering motion. The test load level was 1.1 GPa maximum Hertz contact stress at the pitch-line. The trend of total wear as a function of test cycles was linear, and the wear depth rate was approximately 1.2 nm maximum wear depth per gear dithering cycle. The observed wear rate was about 600 times greater than the wear rate for the same gears operated at high speed and lubricated with oil.

  15. Concentration Polarization to Measure Nano-pore Accessibility

    NARCIS (Netherlands)

    Solsona, Miguel; Eijkel, Jan C.T.; Olthuis, Wouter; Papadimitriou, Vasileios; van den Berg, Albert; Abelmann, Leon; Weckhuysen, Bert M.; Nieuwelink, A. E.

    2017-01-01

    Understanding the deactivation process in porous catalysts is of tremendous economic significance. We demonstrate the feasibility of using the concentration polarization method to obtain the pore accessibility distribution at single particle level for the first time. By using this technique we could

  16. Polyether sulfone/hydroxyapatite mixed matrix membranes for protein purification

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Junfen, E-mail: junfensun@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, North People Road 2999, Shanghai 201620 (China); Wu, Lishun [Department of Chemistry and Chemical Engineering, Heze University, Daxue Road 2269, Heze, Shandong Province 274015 (China)

    2014-07-01

    This work proposes a novel approach for protein purification from solution using mixed matrix membranes (MMMs) comprising of hydroxyapatite (HAP) inside polyether sulfone (PES) matrix. The influence of HAP particle loading on membrane morphology is studied. The MMMs are further characterized concerning permeability and adsorption capacity. The MMMs show purification of protein via both diffusion as well as adsorption, and show the potential of using MMMs for improvements in protein purification techniques. The bovine serum albumin (BSA) was used as a model protein. The properties and structures of MMMs prepared by immersion phase separation process were characterized by pure water flux, BSA adsorption and scanning electron microscopy (SEM).

  17. The measurement of airborne rodon daughter concentrations in the atmosphere

    International Nuclear Information System (INIS)

    Ha, C.W.; Lee, J.K.; Moon, P.S.

    1979-01-01

    A simple method for determining the airborne concentration of radon daughter products has been developed, which is based on gross alpha counting of the air filter collections at several time intervals after completion of air sampling. The concentration of each nuclide is then obtained from an equation involving the alpha disintegrations, the sampling time, and the known numerical coefficients. The state of radioactive disequilibrium is also inventigated. The atmosphere sampled in the TRIGA Mark-III reactor room was largely in disequilibrium. The extent of radioactive disequilibrium between radon daughter products seems likely depend on sampling times associated with turbulence conditions. The data obtained here will certainly provide useful information on the evaluation of internal exposure and calibration of effluent monitoring instruments. (author)

  18. The analyses of measured nuclide concentration in project ISTC 2670

    International Nuclear Information System (INIS)

    Chrapciak, V.

    2006-01-01

    In this article are analyzed experiments for WWER-440 fuel and compared with theoretical results by new version of the SCALE 5 code: nuclide compositions - measurement in Kurchatov institute for 3.6% - measurement in Dimitrovgrad for 3.6% (project ISTC 2670) The focus is on modules TRITON and ORIGEN-S (Authors)

  19. Measurement of aerosol concentration with a beta-ray gage

    International Nuclear Information System (INIS)

    Auzac, G. d'; Dubillot, J.

    1978-01-01

    Because dusts in suspension are a dangerous polluting agent, several methods have been used to monitor their concentration. Among these, the beta-ray gage enjoys a privileged position. The authors describe such a gage and discuss the conditions to be observed for it to be capable of giving results comparable to those obtained with manual gravimetric methods. The satisfactory results obtained led to standardization of the method and a whole range of instruments based on this principle are employed in pollution supervising networks and for continuously monitoring industrial emissions [fr

  20. Study on the radiation effect of polyether-urethane in the γ radiation field

    International Nuclear Information System (INIS)

    Huang, W.; Xu, Y.S.; Chen, X.J.; Gao, X.L.; Tang, Y.M.; Wang, H.Y.

    2005-01-01

    Polyether-urethane (ETPU) is made up of hard and soft sections. The hard section which is mainly in crystalline state is carbamate, and soft section which is in amorphous state is polyether. Reference reports in detail the degradation of polyurethane deduced by thermal oxidation. The result shows that the thermal degradation begins with the caramate group. The polyalcohol is the weak point of polyurethane degradation in the presence of oxygen. Similarly, the anti-radiation of carbamate (hard section) is superior to that of polyether (soft section) In our former work, we have discussed the degradation of ETPU foam deduced by electron beam. And we have studied the composition and yields of gas products from the radiation degradation, and the changes of the thermal property, micro-phase separation and the microscopic form of irradiated samples. In this article, the radiation effect of γ-ray on polyether-urethane foam was studied. The gas products from irradiated samples were analyzed quantitatively and qualitatively by gas chromatography. Compared with the standard gas, the gas products are H 2 , CO 2 , CH 4 , C 2 H 6 and so on. Among these gases, the gas yield of CO 2 is the most, that of H 2 is less, and those of CH 4 and C 2 H 6 are the least. The yields of different sorts of gases increase with the dose raising. Furthermore, the radiation degradation of the sample is the most serious in the oxygen atmosphere, less in air, and the least in vacuum. ESR of ETPU sample irradiated by γ ray in vacuum is shown in figurel, which is determined at the room temperature, and ESR of polyester-urethane (ESPU) irradiated by UV light is shown in figure 2. It can be seen from these two figures that the spectral shape is different. The radical peak in the sample irradiated by UV light is symmetrical, which indicates that there is only one sort of radical; but that is not the truth to the sample irradiated by gamma ray for its asymmetrical radical peak. According to the results of

  1. The Continuing Saga of the Marine Polyether Biotoxins

    Science.gov (United States)

    Nicolaou, K. C.; Frederick, Michael O.; Aversa, Robert J.

    2009-01-01

    Lead-in Brevetoxin B emerged from the sea and into the laboratories of Nakanishi and Clardy who, in 1981, reported its magnificent and unprecedented structure. With its ladder-like fused polyether molecular architecture, potent toxicity, and fascinating voltage-sensitive sodium channel-based mechanism of action, it immediately captured the imagination of chemists around the world. Their synthetic escapades resulted in numerous new synthetic methods and strategies for the construction of cyclic ethers, and culminated in several impressive total syntheses of this imposing molecule and some of its equally challenging siblings that followed. Indeed, many more brevetoxin-type marine polyethers have been reported since 1981 with maitotoxin being not only the most complex and most toxic of the class, but also the largest non-polymeric natural product known to date. In this article, we begin with a brief history of these biotoxins and the phenomena that led to their isolation and highlight their biological properties and mechanism of action. We then review the chemical synthesis endeavors so far published in this long running saga, placing particular emphasis on the new synthetic methods and technologies discovered, developed and applied to their total syntheses over the last few decades. Finally, we conclude with a discussion of the, as yet unfinished, story of maitotoxin, and project into the future of this fascinating area of research. PMID:18763702

  2. Parasite infection accelerates age polyethism in young honey bees

    Science.gov (United States)

    Lecocq, Antoine; Jensen, Annette Bruun; Kryger, Per; Nieh, James C.

    2016-01-01

    Honey bees (Apis mellifera) are important pollinators and their health is threatened worldwide by persistent exposure to a wide range of factors including pesticides, poor nutrition, and pathogens. Nosema ceranae is a ubiquitous microsporidian associated with high colony mortality. We used lab micro-colonies of honey bees and video analyses to track the effects of N. ceranae infection and exposure on a range of individual and social behaviours in young adult bees. We provide detailed data showing that N. ceranae infection significantly accelerated the age polyethism of young bees, causing them to exhibit behaviours typical of older bees. Bees with high N. ceranae spore counts had significantly increased walking rates and decreased attraction to queen mandibular pheromone. Infected bees also exhibited higher rates of trophallaxis (food exchange), potentially reflecting parasite manipulation to increase colony infection. However, reduction in queen contacts could help bees limit the spread of infection. Such accelerated age polyethism may provide a form of behavioural immunity, particularly if it is elicited by a wide variety of pathogens. PMID:26912310

  3. Parasite infection accelerates age polyethism in young honey bees.

    Science.gov (United States)

    Lecocq, Antoine; Jensen, Annette Bruun; Kryger, Per; Nieh, James C

    2016-02-25

    Honey bees (Apis mellifera) are important pollinators and their health is threatened worldwide by persistent exposure to a wide range of factors including pesticides, poor nutrition, and pathogens. Nosema ceranae is a ubiquitous microsporidian associated with high colony mortality. We used lab micro-colonies of honey bees and video analyses to track the effects of N. ceranae infection and exposure on a range of individual and social behaviours in young adult bees. We provide detailed data showing that N. ceranae infection significantly accelerated the age polyethism of young bees, causing them to exhibit behaviours typical of older bees. Bees with high N. ceranae spore counts had significantly increased walking rates and decreased attraction to queen mandibular pheromone. Infected bees also exhibited higher rates of trophallaxis (food exchange), potentially reflecting parasite manipulation to increase colony infection. However, reduction in queen contacts could help bees limit the spread of infection. Such accelerated age polyethism may provide a form of behavioural immunity, particularly if it is elicited by a wide variety of pathogens.

  4. The measurement of dissolved and gaseous carbon dioxide concentration

    Science.gov (United States)

    Zosel, J.; Oelßner, W.; Decker, M.; Gerlach, G.; Guth, U.

    2011-07-01

    In this review the basic principles of carbon dioxide sensors and their manifold applications in environmental control, biotechnology, biology, medicine and food industry are reported. Electrochemical CO2 sensors based on the Severinghaus principle and solid electrolyte sensors operating at high temperatures have been manufactured and widely applied already for a long time. Besides these, nowadays infrared, non-dispersive infrared and acoustic CO2 sensors, which use physical measuring methods, are being increasingly used in some fields of application. The advantages and drawbacks of the different sensor technologies are outlined. Electrochemical sensors for the CO2 measurement in aqueous media are pointed out in more detail because of their simple setup and the resulting low costs. A detailed knowledge of the basic detection principles and the windows for their applications is necessary to find an appropriate decision on the technology to be applied for measuring dissolved CO2. In particular the pH value and the composition of the analyte matrix exert important influence on the results of the measurements.

  5. The measurement of dissolved and gaseous carbon dioxide concentration

    International Nuclear Information System (INIS)

    Zosel, J; Oelßner, W; Decker, M; Gerlach, G; Guth, U

    2011-01-01

    In this review the basic principles of carbon dioxide sensors and their manifold applications in environmental control, biotechnology, biology, medicine and food industry are reported. Electrochemical CO 2 sensors based on the Severinghaus principle and solid electrolyte sensors operating at high temperatures have been manufactured and widely applied already for a long time. Besides these, nowadays infrared, non-dispersive infrared and acoustic CO 2 sensors, which use physical measuring methods, are being increasingly used in some fields of application. The advantages and drawbacks of the different sensor technologies are outlined. Electrochemical sensors for the CO 2 measurement in aqueous media are pointed out in more detail because of their simple setup and the resulting low costs. A detailed knowledge of the basic detection principles and the windows for their applications is necessary to find an appropriate decision on the technology to be applied for measuring dissolved CO 2 . In particular the pH value and the composition of the analyte matrix exert important influence on the results of the measurements. (topical review)

  6. Quality control of the concentration measurement of specific radioactive isotopes

    International Nuclear Information System (INIS)

    Loria, Luis Guillermo; Badilla, Mauricio

    2008-01-01

    The counting efficiency of a gamma spectroscopy chain with a Ge (H.p) detector was measured. The Monte Carlo simulation and standard reference materials, in order to calculate the specific activity from 4 reference materials, and from intercomparison samples were used. The purpose was to evaluate the analytical results obtained in the Laboratorio de Espectroscopia Gamma. (author) [es

  7. Fluxes of chemically reactive species inferred from mean concentration measurements

    NARCIS (Netherlands)

    Galmarini, S.; Vilà-Guerau De Arellano, J.; Duyzer, J.H.

    1997-01-01

    A method is presented for the calculation of the fluxes of chemically reactive species on the basis of routine measurements of meteorological variables and chemical species. The method takes explicity into account the influence of chemical reactions on the fluxes of the species. As a demonstration

  8. Epoxide hydrolase-lasalocid a structure provides mechanistic insight into polyether natural product biosynthesis.

    Science.gov (United States)

    Wong, Fong T; Hotta, Kinya; Chen, Xi; Fang, Minyi; Watanabe, Kenji; Kim, Chu-Young

    2015-01-14

    Biosynthesis of some polyether natural products involves a kinetically disfavored epoxide-opening cyclic ether formation, a reaction termed anti-Baldwin cyclization. One such example is the biosynthesis of lasalocid A, an ionophore antibiotic polyether. During lasalocid A biosynthesis, an epoxide hydrolase, Lsd19, converts the bisepoxy polyketide intermediate into the tetrahydrofuranyl-tetrahydropyran product. We report the crystal structure of Lsd19 in complex with lasalocid A. The structure unambiguously shows that the C-terminal domain of Lsd19 catalyzes the intriguing anti-Baldwin cyclization. We propose a general mechanism for epoxide selection by ionophore polyether epoxide hydrolases.

  9. Separation of alkali and alkaline earth metals by polyethers using extraction chromatography

    International Nuclear Information System (INIS)

    Smulek, W.; Lada, W.A.

    1979-01-01

    The separation of alkali and alkaline earth metals by means of an acyclic polyether, 1,13-bis(8-chinolinyl)-1, 4, 7, 10, 13-pentaoxatridecane (CPOD), and cyclic polyethers, benzo-15-crown-5 (BC), dibenzo-18-crown-6 (DBC) and dicyclohexyl-18-crown-6 (DCHC), using extraction chromatography has been studied. The alkali metals can be effectively separated using SCN - as the accompanying ion. For alkaline earth metals, the best results were obtained with ClO 4 - ions. Different elution sequences for these groups were observed using chloroform and/meen=/ sitylene as diluents for the polyethers. (author)

  10. Synthesis of Marine Polycyclic Polyethers via Endo-Selective Epoxide-Opening Cascades

    Directory of Open Access Journals (Sweden)

    Timothy F. Jamison

    2010-03-01

    Full Text Available The proposed biosynthetic pathways to ladder polyethers of polyketide origin and oxasqualenoids of terpenoid origin share a dramatic epoxide-opening cascade as a key step. Polycyclic structures generated in these biosynthetic pathways display biological effects ranging from potentially therapeutic properties to extreme lethality. Much of the structural complexity of ladder polyether and oxasqualenoid natural products can be traced to these hypothesized cascades. In this review we summarize how such epoxide-opening cascade reactions have been used in the synthesis of ladder polyethers and oxasqualenoid natural products.

  11. The effect of polyether on the separation of pentlandite and serpentine

    Directory of Open Access Journals (Sweden)

    Xiaowen Zhou

    2015-10-01

    Full Text Available The effect of polyether on the separation of pentlandite from serpentine has been studied. In addition to flotation and sedimentation tests, electrophoresis and adsorption tests have been conducted. The flotation and sedimentation results show that serpentine impairs flotation performance of pentlandite, by adhering to the pentlandite particles. Addition of the polyether could promote the dispersion of the mixed sample of pentlandite and serpentine in alkaline conditions and significantly reduce adverse effects of serpentine on the pentlandite flotation. The electrophoresis and adsorption tests show that polyether can selectively adsorb onto pentlandite surface through hydrophobic reaction and remove serpentine slime particles from pentlandite surfaces by steric hindrance effect.

  12. Partial molar volumes of organic solutes in water. XXVII. Two aliphatic polyethers (triglyme, tetraglyme) at temperatures T = 298–573 K and pressures up to 30 MPa

    International Nuclear Information System (INIS)

    Cibulka, Ivan

    2016-01-01

    Highlights: • Standard molar volumes of two linear aliphatic polyethers in water are presented. • Data were obtained in the range T from (298 to 573) K and p up to 30 MPa. • Data combined with those obtained previously are analyzed and compared with standard molar volumes of cyclic ethers. - Abstract: Densities of dilute aqueous solutions of two linear aliphatic polyethers: 2,5,8,11-tetraoxadodecane (triethylene glycol dimethyl ether, triglyme) and 2,5,8,11,14-pentaoxapentadecane (tetraethylene glycol dimethyl ether, tetraglyme), measured in the temperature range from (298 to 573) K and at pressures up to 30 MPa using an automated flow vibrating-tube densimeter are reported. Standard molar volumes were evaluated from the measured data. The present values complement previous measurements performed for the title polyethers at atmospheric pressure in the temperature range from (278 to 343) K and extend the knowledge to temperature and pressure ranges in which the data on standard molar volumes for lower members of the homologous series (monoglyme, diglyme) are already available.

  13. Measurement of radon concentration in Taiz city dwellings-yemen

    International Nuclear Information System (INIS)

    Ali, Taher M.; Ahmed, Hayel A.; Ismail, Rokhsana M.

    2001-01-01

    Radon gas considered being a high part of natural radiation background. Emitting alpha particles; radon daughters may be deposited into the lungs and cause health hazards. For this reason, estimation of radon levels in dwellings was done in many countries. In our country, Radon group in the Department of physics, University of Aden has been studied radon level in Aden dwelling. The present study is about the radon level in Taiz City - Yemen. Passive diffusion dosimeters containing (SSNTD s ) Cr - 39 detectors were used in the present work. 125 dosimeters were distributed into dwellings of ten regions in Taiz City. Results obtained show that Rn 222 levels vary between 4 Bq/m 3 and 99 Bq/m 3 . The average concentration in Al-Hasseb district is 23 Bq/m 3 and in Algumhuri hospital district is 53 Bq/m 3 . In other regions it varies between the two values. Whereas the general average in the Taiz City is 34 Bq/m 3 . (author)

  14. Is lowering reducing sugars concentration in French fries an effective measure to reduce acrylamide concentration in food service establishments?

    Science.gov (United States)

    Sanny, M; Jinap, S; Bakker, E J; van Boekel, M A J S; Luning, P A

    2012-12-01

    The objective of this study was to obtain insight into the actual effectiveness of lowering reducing sugars concentration in par-fried potato strips on the concentration and variation of acrylamide in French fries prepared in real-life situations in food service establishments. Acrylamide, frying time, frying temperature, and reducing sugars were measured and characteristics of fryers were recorded. Data showed that the use of par-fried potato strips with lower concentrations of reducing sugars than the commonly used potato strips was an effective measure to reduce acrylamide concentrations in French fries prepared under standardised frying conditions. However, there was still large variation in the acrylamide concentrations in French fries, although the variation in reducing sugars concentrations in low and normal types of par-fried potato strips was very small and the frying conditions were similar. Factors that could affect the temperature-time profile of frying oil were discussed, such as setting a lower frying temperature at the end than at the start of frying, product/oil ratio and thawing practice. These need to be controlled in daily practice to reduce variation in acrylamide. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Use of polyethers in the treatment of acidic high activity nuclear wastes. First progress report, June 1, 1975--May 31, 1977

    International Nuclear Information System (INIS)

    Davis, M.W. Jr.

    1977-01-01

    Objective is to develop a solvent extraction system for treating acidic high activity nuclear wastes in order to remove 99.9% of the cesium and strontium. A series of macrocyclic polyethers ''crown compounds'' which can form organic soluble complexes with the alkali metals (Cs +1 ) and the alkali earth metals (Sr +2 ) are being screened. Thus far, five ''crown'' compounds have been tested for solubility in both carbon tetrachloride and kerosene, each solvent containing a range of TBP concentrations. Also distribution coefficients of both cesium and strontium have been measured. Results have been negative in that sufficient extraction of either Cs +1 or Sr +2 into the organic phase was not achieved to make a solvent extraction process feasible. The highest distribution coefficient obtained (organic/aqueous)/sup (2)/ was 0.04 +- 0.02 for both Sr +2 and Cs +1 . The problem seems to lie in the low solubility of the ''crowns'' in the organic phases and the apparent ability of the ''crowns'' to distribute into the aqueous phase and complex the metal. The solubility data indicate that the addition of aliphatic character to the ''crowns'' improves their organic solubility whereas aromatic addition decreases their organic solubility. Accordingly, a new ''crown'', 4, 4'-didecanolybenzo 24-crown-8, was ordered from the Parish Chemical Company in Provo, Utah

  16. L-Arginine modified multi-walled carbon nanotube/sulfonated poly(ether ether ketone) nanocomposite films for biomedical applications

    Science.gov (United States)

    Kaya, Hatice; Bulut, Osman; Kamali, Ali Reza; Ege, Duygu

    2018-06-01

    Favorable implant-tissue interactions are crucial to achieve successful osseointegration of the implants. Poly(ether ether ketone) (PEEK) is an interesting alternative to titanium in orthopedics because of its low cost, high biocompatibility and comparable mechanical properties with cancellous bone. Despite these advantages; however, the untreated surface of PEEK fails to osseointegrate due to its bioinert and hydrophobic behavior. This paper deals with the surface modification of PEEK with a novel method. For this, PEEK was first treated with concentrated sulfuric acid to prepare sulfonated PEEK (SPEEK) films using a solvent casting method. Then, 1 and 2 wt% multi-walled carbon nanotube was incorporated into SPEEK to form nanocomposite films. The samples were characterized with Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy. After successful preparation of the nanocomposite films, L-arginine was covalently conjugated on the nanocomposite films to further improve their surface properties. Subsequently, the samples were characterized using X-ray Photoemission Spectroscopy (XPS), water contact angle measurements and Atomic Force Microscopy (AFM) and Dynamic Mechanical Thermal Analysis (DMTA). Finally, cell culture studies were carried out by using Alamar Blue assay to evaluate the biocompatibility of the films. The results obtained indicate the successful preparation of L-arginine-conjugated MWCNT/SPEEK nanocomposite films. The modified surface shows potential to improve implants' mechanical and biological performances.

  17. Concentration measurements of biodiesel in engine oil and in diesel fuel

    International Nuclear Information System (INIS)

    Mäder, A; Eskiner, M; Burger, C; Rossner, M; Krahl, J; Ruck, W

    2012-01-01

    This work comprised a method for concentration measurements of biodiesel in engine oil as well as biodiesel in diesel fuel by a measurement of the permittivity of the mixture at a frequency range from 100 Hz to 20 kHz. For this purpose a special designed measurement cell with high sensitivity was designed. The results for the concentration measurements of biodiesel in the engine oil and diesel fuel shows linearity to the measurement cell signal for the concentration of biodiesel in the engine oil between 0.5% Vol. to 10% Vol. and for biodiesel in the diesel fuel between 0% Vol. to 100% Vol. The method to measure the concentration of biodiesel in the engine oil or the concentration of biodiesel in the diesel fuel is very accurate and low concentration of about 0.5% Vol. biodiesel in engine oil or in diesel fuel can be measured with high accuracy.

  18. The measurement of radon concentration of soil in a civil construction site

    International Nuclear Information System (INIS)

    Liu Hanbin; Fan Guang

    2004-01-01

    Radon is one of radioactive resources which do harm to human body. Therefore, its concentration in the soil should be measured before the civil construction works. Code for Indoor Environmental Pollution Control of Civil Building Engineering (GB50325-2001) is the main norm used for soil radon concentration measurement. By using FD-3017 RaA radon measuring equipment, the soil radon concentration in a civil building engineering site has been measured, the result shows that the concentration is lower than the regional average value, radon protective measures should not be installed in that site. (authors)

  19. Composite Membranes Based on Polyether Sulfone

    Directory of Open Access Journals (Sweden)

    A. Soroush

    2010-12-01

    Full Text Available The role of polymeric additives such as PVP and PEG is studied with respect to the morphology of PES porous layer as a sublayer of nanofiltration composite membranes based on PES/PA. Results show that by phase inversionprocess of quaternary systems comprised of four components of polymer/solvent/non-solvent/additive and the diffusion of intertwined polymers some changes occur in membrane morphology with changes in their concentration. With addition of PVP, tear-like pores, finger-like and channel-like morphology change to enlarged channel cavities and by adding more PVP, membrane morphology changes further and spongy regions are extended in the membrane. Presence of PEG in casting solution delayed the precipitation time. By adding PEG, the solution viscosity is increased which is followed by decreases in diffusion rates of solvent/non-solvent in coagulation bath.Therefore, membrane morphology shifts to small pores and spongier region. Another effect of increased PEG content would be deformed PA layer formation in PES sublayer which affects membrane performance. However, PVP as an additive does not change membrane salt rejection very much while it leads to higher fluxes. A membrane with 2.5 percent PVP would perform by 40 percent flux increases, while a membrane with 5% PVP shows flux reductions even below the initial value. Contrary to PVP, the PEG content of 20 percent leads to 4 folds flux increases and in a membrane with 50 percent PEG, there is a flux increase by 7 folds and drop in salt rejection occurs by 50 percent and 70 percent, respectively.

  20. System for measuring of air concentration in air-steam mixture during the transients

    International Nuclear Information System (INIS)

    Gorbenko, Gennady A.; Gakal, Pavlo G.; Epifanov, Konstantin S.; Osokin, Gennady V.; Smirnov, Sergey V.

    2006-01-01

    Description of system for air concentration measuring in air-steam mixture during the transients is represented. Air concentration measuring is based on discrete sampling method. The measuring system consists of sampler, transport pipeline, distributor and six measuring vessels. From the sampler air-steam mixture comes to distributor through transport pipeline and fills consecutively the measuring vessels. The true air concentration in place of measurement was defined based on measured air concentration in samples taken from measuring vessels. For this purpose, the mathematical model of transients in measuring system was developed. Air concentration transient in air-steam mixture in place of measurement was described in mathematical model by air concentration time-dependent function. The function parameters were defined based on air concentration measured in samples taken from measuring vessels. Estimated error of air concentration identification was about 10%. Measuring system was used in experiments on EREC BKV-213 test facility intended for testing of VVER-440/V-213 reactor barbotage-vacuum system

  1. Epoxide hydrolase Lsd19 for polyether formation in the biosynthesis of lasalocid A: direct experimental evidence on polyene-polyepoxide hypothesis in polyether biosynthesis.

    Science.gov (United States)

    Shichijo, Yoshihiro; Migita, Akira; Oguri, Hiroki; Watanabe, Mami; Tokiwano, Tetsuo; Watanabe, Kenji; Oikawa, Hideaki

    2008-09-17

    Polyether metabolites are an important class of natural products. Although their biosynthesis, especially construction of polyether skeletons, attracted organic chemists for many years, no experimental data on the enzymatic polyether formation has been obtained. In this study, a putative epoxide hydrolase gene lsd19 found on the biosynthetic gene cluster of an ionophore polyether lasalocid was cloned and successfully overexpressed in Escherichia coli. Using the purified Lsd19, a proposed substrate, bisepoxyprelasalocid, and its synthesized analogue were successfully converted into lasalocid A and its derivative via a 6-endo-tet cyclization mode. On the other hand, treatment of the bisepoxide with trichloroacetic acid gave isolasalocid A via a 5-exo-tet cyclization mode. Therefore, the enzymatic conversion observed in this study unambiguously showed that the bisepoxyprelasalocid is an intermediate of the lasalocid biosynthesis and that Lsd19 catalyzes the sequential cyclic ether formations involving an energetically disfavored 6-endo-tet cyclization. This is the first example of the enzymatic epoxide-opening reactions leading to a polyether natural product.

  2. Highly selective Ba2+ separations with acyclic, lipophilic di-[N-(X)sulfonyl carbamoyl] polyethers.

    Science.gov (United States)

    Elshani, Sadik; Chun, Sangki; Amiri-Eliasi, Bijan; Bartsch, Richard A

    2005-01-14

    New lipophilic acyclic polyethers with two N-(X)sulfonyl carbamoyl groups of "tunable" acidity exhibit remarkable selectivity for Ba2+ over other alkaline earth metal ions in competitive solvent extraction and transport across polymer inclusion membranes.

  3. Glycerol etherification with TBA: high yield to poly-ethers using a membrane assisted batch reactor.

    Science.gov (United States)

    Cannilla, Catia; Bonura, Giuseppe; Frusteri, Leone; Frusteri, Francesco

    2014-05-20

    In this work, a novel approach to obtain high yield to poly-tert-butylglycerolethers by glycerol etherification reaction with tert-butyl alcohol (TBA) is proposed. The limit of this reaction is the production of poly-ethers, which inhibits the formation of poly-ethers potentially usable in the blend with conventional diesel for transportation. The results herein reported demonstrate that the use of a water permselective membrane offers the possibility to shift the equilibrium toward the formation of poly-ethers since the water formed during reaction is continuously and selectively removed from the reaction medium by the recirculation of the gas phase. Using a proper catalyst and optimizing the reaction conditions, in a single experiment, a total glycerol conversion can be reached with a yield to poly-ethers close to 70%, which represents data never before reached using TBA as reactant. The approach here proposed could open up new opportunities for all catalytic reactions affected by water formation.

  4. In Situ Preparation of Polyether Amine Functionalized MWCNT Nanofiller as Reinforcing Agents

    Directory of Open Access Journals (Sweden)

    Ayber Yıldrım

    2014-01-01

    Full Text Available In situ preparation of polyether amine functionalized cross-linked multiwalled carbon nanotube (MWCNT nanofillers may improve the thermal and mechanical properties of the composites in which they are used as reinforcing agents. The reduction and functionalization of MWCNT using ethylenediamine in the presence of polyether amine produced stitched MWCNT's due to the presence of two amine (–NH2 functionalities on both sides of the polymer. Polyether amine was chosen to polymerize the carboxylated MWCNT due to its potential to form bonds with the amino groups and carboxyl groups of MWCNT which produces a resin used as polymeric matrix for nanocomposite materials. The attachment of the polyether amine (Jeffamine groups was verified by TGA, FT-IR, XRD, SEM, and Raman spectroscopy. The temperature at which the curing enthalpy is maximum, observed by DSC, was shifted to higher values by adding functionalized MWCNT. SEM images show the polymer formation between MWCNT sheets.

  5. Ion-conductive properties of polyether-based composite electrolytes filled with mesoporous silica, alumina and titania

    International Nuclear Information System (INIS)

    Tominaga, Yoichi; Endo, Masanori

    2013-01-01

    Composite polymer electrolytes were prepared consisting of amorphous polyether, Li salt and mesoporous inorganic filler, and we investigated their ion-conductive properties. We synthesized three types of filler, mesoporous silica, alumina and titania (MP-Si, Al, Ti), and characterized their structural and physicochemical properties using SEM, TEM, SAXS and BET surface area measurements. From these measurements, we confirmed that MP fillers have well-defined arrays of mesoporous and hexagonal structures. Dependence on the MP filler content of the glass transition temperature (T g ) revealed that the addition of filler to original polyether-salt electrolyte causes T g decrease, to due to the dissociation of aggregated ions such as triples or crystalline complex domains. The MP-Ti composites had the greatest ionic conductivity (1.4 × 10 −5 S/cm, 7.5 wt% at 30 °C) of all samples, and the values were more than double that of the original. The addition of MP-Ti also increased the lithium transference number, because the electrolyte/filler interface provided active sites that increase mobile Li ions and conducting paths so as to enhance the mobility

  6. A Comparative Evaluation of the Linear Dimensional Accuracy of Four Impression Techniques using Polyether Impression Material

    OpenAIRE

    Manoj, Smita Sara; Cherian, K. P.; Chitre, Vidya; Aras, Meena

    2013-01-01

    There is much discussion in the dental literature regarding the superiority of one impression technique over the other using addition silicone impression material. However, there is inadequate information available on the accuracy of different impression techniques using polyether. The purpose of this study was to assess the linear dimensional accuracy of four impression techniques using polyether on a laboratory model that simulates clinical practice. The impression material used was Impregu...

  7. A NOVEL RHODAMINE-BASED FLUORESCENCE CHEMOSENSOR CONTAINING POLYETHER FOR MERCURY (II IONS IN AQUEOUS SOLUTION

    Directory of Open Access Journals (Sweden)

    Wenqi Du

    Full Text Available A novel rhodamine-based Hg2+ chemosensor P2 containing polyether was readily synthesized and investigated, which displayed high selectivity and sensitivity for Hg2+. Because of good water-solubility of polyther, the rhodamine-based chemosensor containing polyether can be used in aqueous solution. The sensor responded rapidly to Hg2+ in pure water solutions with a 1:1 stoichiometry. Meanwhile, it indicated excellent adaptability and also the responsiveness.

  8. Genetic Screening Strategy for Rapid Access to Polyether Ionophore Producers and Products in Actinomycetes ▿ †

    OpenAIRE

    Wang, Hao; Liu, Ning; Xi, Lijun; Rong, Xiaoying; Ruan, Jisheng; Huang, Ying

    2011-01-01

    Polyether ionophores are a unique class of polyketides with broad-spectrum activity and outstanding potency for the control of drug-resistant bacteria and parasites, and they are produced exclusively by actinomycetes. A special epoxidase gene encoding a critical tailoring enzyme involved in the biosynthesis of these compounds has been found in all five of the complete gene clusters of polyether ionophores published so far. To detect potential producer strains of these antibiotics, a pair of d...

  9. Study of distillation and degradation of perfluoro polyether; Estudo da destilacao e degradacao do perfluoropolieter

    Energy Technology Data Exchange (ETDEWEB)

    Lopergolo, Lilian Cristine

    1997-07-01

    Perfluoro-polyethers, PFPE, were first synthesised by Sianesi and collaborators giving rise to a new lubricant oils and greases classes with several applications. Perfluoro polyethers have excellent properties, for instance: high chemical stability and thermal stability, high density, high radiation resistance and excellent lubricating properties. FOMBLIN-Y oil is one of the perfluoro polyethers used as a lubricant in vacuum systems applied in the UF{sub 6} enrichment installations. Due to its excellent properties and for its applications in the nuclear field, IPEN-CNEN/S P had the interest to dominate its production technology with the aim to substitute the commercial FOMBLIN-Y oil used in the national consumption. The FOMBLIN-Y oil synthesis method, adopted in IPEN-CNEN/S P, made by the photooxidation of the hexa fluoro propylene. In this work we study the fraction separation of the national available production with restricted an increased molecular weights which was obtained by fraction distillation in a vacuum according to the ASTM D-1160 norm. We also study the catalytic effect of metals on the thermal stability of perfluoro polyethers. The inertness of perfluoro polyethers at temperatures higher than 300 deg C is strongly affected by presence of some metals. Al and Ti alloys cause fluid degradation at 250 deg C. This degradation is very important because it has a yield increase of the perfluoro polyethers production. (author)

  10. On solvent extraction of metals by macrocyclic polyethers

    International Nuclear Information System (INIS)

    Ionov, V.P.

    1984-01-01

    The Ksub(γ) parameter characterizing effective ion charges in ionic associates of metal salts is suggested; these charges parallel with other factors determine the metals extraction by macrocyclic polyethers (crown-ethers). The dependence of metal extraction constant on the Ksub(γ) parameter is discussed. It is shown that the less effective cation charge of alkali metal ionic associates, the more probable its entering the crown-ether cavity. The synergetic crown-ethers extraction is bound as well with Ksub(γ) of metal salts. The differences in the cation extraction constants having the same ionic radius are explained with account of different values of Ksub(γ) parameters of these salts

  11. Stability complexes of lanthanide ions with some macrocyclic polyethers

    International Nuclear Information System (INIS)

    Poluehktov, N.S.; Malinka, E.V.; Meshkova, S.B.; Bel'tyukova, S.V.; Danilkovich, M.M.

    1984-01-01

    Stability of lanthanide complexes with macrocyclic polyethers has been studied versus the number of f-electrons, spin- and orbital angular momenta of the Lu 3+ ion ground states. The following compounds were used as macrocyclic complexones: 12-crown-4 (12C4), tert-bulylbenzo-15-crown-5(BB15C5), 18-crown-6 (18C6), ditert-butylbenzo-18-crown-6(DBB18C6), dibenzo-30-crown-10 (DB30C10), cryptand [2, 2, 1] (Cr[2, 2, 1]). It is shoWn that the stability constants of the studied lanthanide complexes can be described rather satisfactorily by an expression suggested earlier that relates their values with the number of 4f-electrons and the S and L quantum numbers of the ground states of the lantharide ions

  12. Study on epoxy resin modified by polyether ionic liquid

    Science.gov (United States)

    Jin, X. C.; Guo, L. Y.; Deng, L. L.; Wu, H.

    2017-06-01

    Chloride 1-carboxyl polyether-3-methyl imidazole ionic liquid (PIIL) was synthesized. Then blended with epoxy resin(EP) to prepare the composite materials of PIIL/EP, which cured with aniline curing agent. The structure and curing performance of PIIL/EP were determined by FT-IR and DSC. The effects of the content of PIIL on strength of EP were studied. The results show that the PIIL was the target product. The strength was improved significantly with increase of the PIIL content. The obvious rubber elasticity of PIIL/EP after cured was showed when the content of PIIL accounts for 40% and the impact strength was up to 15.95kJ/m2.

  13. 40 CFR 761.316 - Interpreting PCB concentration measurements resulting from this sampling scheme.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Interpreting PCB concentration... § 761.79(b)(3) § 761.316 Interpreting PCB concentration measurements resulting from this sampling... composite is 20 µg/100 cm2, then the entire 9.5 square meters has a PCB surface concentration of 20 µg/100...

  14. Airborne plutonium and americium concentrations measured from the top of Rattlesnake Mountain

    International Nuclear Information System (INIS)

    Sehmel, G.A.

    1979-01-01

    Airborne plutonium-239+240 and americium-241 blowing from offsite was measured in an initial experiment at the top of Rattlesnake Mountain. Average airborne concentration measured was similar to fallout concentrations. Airborne plutonium concentrations were independent of wind speed for seven wind speed increments between 0.5 and 31 m/sec. In contrast the airborne americium concentration was a minimum at a wind speed of approximately 7 m/sec. Similarly, the airborne solids concentration in μg/m 3 was a minimum at an intermediate wind speed increment of 7 to 11 m/sec

  15. Measurements of neonatal bilirubin and albumin concentrations : a need for improvement and quality control

    NARCIS (Netherlands)

    van Imhoff, Deirdre E.; Dijk, Peter H.; Weykamp, Cas W.; Cobbaert, Christa M.; Hulzebos, Christian V.

    Accurate and precise bilirubin and albumin measurements are essential for proper management of jaundiced neonates. Data hereon are lacking for Dutch laboratories. We aimed to determine variability of measurements of bilirubin and albumin concentrations typical for (preterm) neonates. Aqueous, human

  16. Measurements of neonatal bilirubin and albumin concentrations: a need for improvement and quality control

    NARCIS (Netherlands)

    Imhoff, D.E. van; Dijk, P.H.; Weykamp, C.W.; Cobbaert, C.M.; Hulzebos, C.V.; Liem, K.D.; et al.,

    2011-01-01

    Accurate and precise bilirubin and albumin measurements are essential for proper management of jaundiced neonates. Data hereon are lacking for Dutch laboratories. We aimed to determine variability of measurements of bilirubin and albumin concentrations typical for (preterm) neonates. Aqueous, human

  17. Automatic measuring device for atomic oxygen concentrations (1962); Dispositif de mesure automatique de concentrations d'oxygene atomique (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Weill, J; Deiss, M; Mercier, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-07-01

    Within the framework of the activities of the Autonomous Reactor Electronics Section we have developed a device, which renders automatic one type of measurement carried out in the Physical Chemistry Department at the Saclay Research Centre. We define here: - the physico-chemical principle of the apparatus which is adapted to the measurement of atomic oxygen concentrations; - the physical principle of the automatic measurement; - the properties, performance, constitution, use and maintenance of the automatic measurement device. It is concluded that the principle of the automatic device, whose tests have confirmed the estimation of the theoretical performance, could usefully be adapted to other types of measurement. (authors) [French] Dans le cadre des activites de la Section Autonome d'Electronique des Reacteurs, il a ete realise et mis au point un dispositif permettant de rendre automatique un type de mesures effectuees au Departement de Physico-Chimie du C.E.N. SACLAY. On definit ici: - le principe physico-chimique de l'appareillage, adapte a la mesure de concentrations de l'oxygene atomique; - le principe physique de la mesure automatique; - les qualites, performances, constitution, utilisation, et maintenance du dispositif de mesure automatique. Il est porte en conclusion, que le principe du dispositif automatique realise, dont les essais ont sensiblement confirme l'evaluation des performances theoriques, pourrait etre utilement adapte a d'autres types de mesures courantes. (auteurs)

  18. Plasma concentrations of blood coagulation factor VII measured by immunochemical and amidolytic methods

    DEFF Research Database (Denmark)

    Bladbjerg, E-M; Gram, J; Jespersen, J

    2000-01-01

    Ever since the coagulant activity of blood coagulation factor VII (FVII:C) was identified as a risk indicator of cardiac death, a large number of studies have measured FVII protein concentrations in plasma. FVII protein concentrations are either measured immunologically with an ELISA method (FVII...

  19. Determination of deuterium concentrations in JET plasmas from fusion reaction rate measurements

    International Nuclear Information System (INIS)

    Jarvis, O.N.; Balet, B.; Cordey, J.G.; Morgan, P.D.; Sadler, G.; Belle, P. van; Conroy, S.; Elevant, T.

    1989-01-01

    The concentration of deuterium in the central regions of JET plasmas, expressed as a fraction of the electron concentration (n d /n e ), has been determined using four different methods involving neutron detection. These measurements are found to be consistent and agree within experimental errors with values deduced from Z eff measurements using visible bremsstrahlung radiation. (author) 11 refs., 1 fig., 1 tab

  20. High concentration suspended sediment measurments using acontinuous fiber optic in-stream transmissometer

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Chris G.; Laycak, Danny T.; Hoppes, William; Tran,Nguyen T.; Shi, Frank G.

    2004-05-26

    Suspended sediment loads mobilized during high flow periods in rivers and streams are largely uncharacterized. In smaller and intermittent streams, a large storm may transport a majority of the annual sediment budget. Therefore monitoring techniques that can measure high suspended sediment concentrations at semi-continuous time intervals are needed. A Fiber optic In-stream Transmissometer (FIT) is presented for continuous measurement of high concentration suspended sediment in storm runoff. FIT performance and precision were demonstrated to be reasonably good for suspended sediment concentrations up to 10g/L. The FIT was compared to two commercially available turbidity devices and provided better precision and accuracy at both high and low concentrations. Both turbidity devices were unable to collect measurements at concentrations greater than 4 g/L. The FIT and turbidity measurements were sensitive to sediment particle size. Particle size dependence of transmittance and turbidity measurement poses the greatest problem for calibration to suspended sediment concentration. While the FIT was demonstrated to provide acceptable measurements of high suspended sediment concentrations, approaches to real-time suspended sediment detection need to address the particle size dependence in concentration measurements.

  1. Significance of radioelement concentration measurements made by airborne gamma-ray spectrometry over the Canadian Shield

    International Nuclear Information System (INIS)

    Charbonneau, B.W.; Killeen, P.G.; Carson, J.M.; Cameron, G.W.; Richardson, K.A.

    1976-01-01

    Results of airborne gamma-ray spectrometer surveys conducted by the Geological Survey of Canada are presented as maps contoured in units of radioelement and concentration ratios. These contoured values represent the average surface concentrations of the radioelements over areas of the order of several square kilometres. The relationship between this ''average surface concentration'' and the radioelement concentration in bedrock underlying the area depends on: (1) the percentage of outcrop; (2) the relation between overburden and bedrock radioelement concentration; (3) percentage of marshland or surface water in the area; (4) soil moisture; and (5) density of vegetation. More than 2500 portable gamma-ray spectrometer analyses of outcrop and overburden have been made in the Bancroft, Elliot Lake and Fort Smith areas of the Canadian Precambrian Shield. In the areas examined, the radioelement concentrations in glacial drift reflect the concentrations in the underlying bedrock. Rocks with near-crustal average contents of thorium, uranium and potassium are overlain by glacial drift having approximately the same concentrations. As the concentration in bedrock increases, the concentration in the local overburden also increases, but not to the same extent. In addition, in-situ gamma-ray spectrometry measurements were made at almost 1000 stations within the area of airborne surveys near Mont Laurier and Elliot Lake. These ground measurements were compared with the airborne measurements by averaging the values for all those ground stations located in the areas between each contour level on airborne maps. Radioelement concentrations in bedrock are considerably higher than corresponding airborne measurements, and this difference between bedrock and airborne values increases at higher radioelement concentrations. Radioelement concentrations in glacial drift are only slightly higher than airborne contour values for the same area. Airborne contour maps of the radioelement ratios

  2. Measurement of airborne concentrations of radon-220 daughter products by alpha-particle spectrometry

    International Nuclear Information System (INIS)

    Kerr, G.D.; Ryan, M.T.; Perdue, P.T.

    1978-01-01

    The decay of naturally occurring uranium-238 and thorium-232 produces radon-222 and radon-220 isotopes which can escape into the atmosphere. If these radon gases become concentrated in air, their daughter products may present an inhalation hazard to man. The airborne concentrations of radon-222 can usually be measured very accurately in the presence of normal airborne concentrations of radon-220 and its daughters. In contrast, the measurements of the airborne concentrations of radon-220 daughters are usually complicated by the presence of radon-222 and its daughters even at normally occurring airborne concentrations. The complications involved in these measurements can be overcome in most situations by using an alpha particle spectrometer to distinguish the activity of radon-222 daughters from that due to radon-220 daughters collected on a filter. A practical spectrometer for field measurements of alpha particle activity on a filter is discussed

  3. Crosslinked poly(ether block amide) composite membranes for organic solvent nanofiltration applications

    KAUST Repository

    Aburabie, Jamaliah; Peinemann, Klaus-Viktor.

    2016-01-01

    Poly(ether block amide) – Pebax® – based membranes are well described for gas separation applications. But only a few publications exist for their application in pressure driven liquid applications like ultrafiltration and nanofiltration. Here we use the commercially available Pebax® 1657 for the preparation of membranes for the filtration of organic solvents. Porous polyacrylonitrile membranes were coated with Pebax® 1657 which was then crosslinked. Toluene diisocyanate (TDI) was used as a crosslinker agent for the coating. Reaction time and crosslinker concentration were optimized for the aimed application. The Pebax® coating and the impact of the TDI on the resulting crosslinked membranes were investigated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). SEM analysis shows a uniform thin coating of the PEBAX that covers the pores of the PAN membranes. FTIR and DSC analysis confirm the crosslinking reaction. Crosslinked Pebax® membranes show high stability toward ethanol propanol, acetone and even dimethylformamide (DMF). In the case of DMF applications, the standard PAN was replaced by crosslinked PAN developed in our laboratory. In order to increase the membranes permeances, graphene oxide (GO) nanosheets were incorporated in the Pebax® coating. These GO containing membranes showed strongly increased permeances for selected solvents. © 2016 Elsevier B.V.

  4. Improved antifouling potential of polyether sulfone polymeric membrane containing silver nanoparticles: self-cleaning membranes.

    Science.gov (United States)

    Rana, Sidra; Nazar, Umair; Ali, Jafar; Ali, Qurat Ul Ain; Ahmad, Nasir M; Sarwar, Fiza; Waseem, Hassan; Jamil, Syed Umair Ullah

    2018-06-01

    A new strategy to enhance the antifouling potential of polyether sulfone (PES) membrane is presented. Chemically synthesized silver nanoparticles (AgNPs) were used to prepare a mixed-matrix PES membrane by the phase inversion technique. Primarily, AgNPs synthesis was confirmed by surface plasmon resonance at 410-430 nm using UV-Visible spectroscopy. X-ray diffraction analysis revealed that AgNPs were crystalline with a diameter of 21 ± 2 nm. Furthermore, PES membranes were characterized by energy dispersive X-ray spectroscopy to confirm the incorporation of AgNPs in membranes. Hydrophilicity of the membranes was enhanced, whereas roughness, mechanical strength and biofouling were relatively reduced after embedding the AgNPs. Antibacterial potential of AgNPs was evaluated for E. coli in the disc diffusion and colony-forming unit (CFU) count method. All of the membranes were assessed for antifouling activity by filtering a control dilution (10 6  CFU/ml) of E. coli and by counting CFU. Anti-biofouling activity of the membrane was observed with different concentrations of AgNPs. Maximum reduction (66%) was observed in membrane containing 1.5% of AgNPs. The addition of antibiotic ceftriaxone enhanced the antibacterial effect of AgNPs in PES membranes. Our practicable antifouling strategy may be applied to other polymeric membranes which may pave the new way to achieve sustainable and self-cleaning membrane reactors on large scale.

  5. Crosslinked poly(ether block amide) composite membranes for organic solvent nanofiltration applications

    KAUST Repository

    Aburabie, Jamaliah

    2016-10-01

    Poly(ether block amide) – Pebax® – based membranes are well described for gas separation applications. But only a few publications exist for their application in pressure driven liquid applications like ultrafiltration and nanofiltration. Here we use the commercially available Pebax® 1657 for the preparation of membranes for the filtration of organic solvents. Porous polyacrylonitrile membranes were coated with Pebax® 1657 which was then crosslinked. Toluene diisocyanate (TDI) was used as a crosslinker agent for the coating. Reaction time and crosslinker concentration were optimized for the aimed application. The Pebax® coating and the impact of the TDI on the resulting crosslinked membranes were investigated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). SEM analysis shows a uniform thin coating of the PEBAX that covers the pores of the PAN membranes. FTIR and DSC analysis confirm the crosslinking reaction. Crosslinked Pebax® membranes show high stability toward ethanol propanol, acetone and even dimethylformamide (DMF). In the case of DMF applications, the standard PAN was replaced by crosslinked PAN developed in our laboratory. In order to increase the membranes permeances, graphene oxide (GO) nanosheets were incorporated in the Pebax® coating. These GO containing membranes showed strongly increased permeances for selected solvents. © 2016 Elsevier B.V.

  6. A new method to measure effective soil solution concentration predicts copper availability to plants.

    Science.gov (United States)

    Zhang, H; Zhao, F J; Sun, B; Davison, W; McGrath, S P

    2001-06-15

    Risk assessments of metal contaminated soils need to address metal bioavailability. To predict the bioavailability of metals to plants, it is necessary to understand both solution and solid phase supply processes in soils. In striving to find surrogate chemical measurements, scientists have focused either on soil solution chemistry, including free ion activities, or operationally defined fractions of metals. Here we introduce the new concept of effective concentration, CE, which includes both the soil solution concentration and an additional term, expressed as a concentration, that represents metal supplied from the solid phase. CE was measured using the technique of diffusive gradients in thin films (DGT) which, like a plant, locally lowers soil solution concentrations, inducing metal supply from the solid phase, as shown by a dynamic model of the DGT-soil system. Measurements of Cu as CE, soil solution concentration, by EDTA extraction and as free Cu2+ activity in soil solution were made on 29 different soils covering a large range of copper concentrations. Theywere compared to Cu concentrations in the plant material of Lepidium heterophyllum grown on the same soils. Plant concentrations were linearly related and highly correlated with CE but were more scattered and nonlinear with respect to free Cu2+ activity, EDTA extraction, or soil solution concentrations. These results demonstrate that the dominant supply processes in these soils are diffusion and labile metal release, which the DGT-soil system mimics. The quantity CE is shown to have promise as a quantitative measure of the bioavailable metal in soils.

  7. Continuous measurement of the radon concentration in water using electret ion chamber method

    International Nuclear Information System (INIS)

    Dua, S.K.; Hopke, P.K.

    1992-10-01

    A radon concentration of 300 pCi/L has been proposed by the US Environmental Protection Agency as a limit for radon dissolved in municipal drinking water supplies. There is therefore a need for a continuous monitor to insure that the daily average concentration does not exceed this limit. In order to calibrate the system, varying concentrations of radon in water have been generated by bubbling radon laden air through a dynamic flowthrough water system. The value of steady state concentration of radon in water from this system depends on the concentration of radon in air, the air bubbling rate, and the water flow rate. The measurement system has been designed and tested using a 1 L volume electret ion chamber to determine the radon in water. In this dynamic method, water flows directly through the electret ion chamber. Radon is released to the air and measured with the electret. A flow of air is maintained through the chamber to prevent the build-up of high radon concentrations and too rapid discharge of the electret. It was found that the system worked well when the air flow was induced by the application of suction. The concentration in the water was calculated from the measured concentration in air and water and air flow rates. Preliminary results suggest that the method has sufficient sensitivity to measure concentrations of radon in water with acceptable accuracy and precision

  8. Optical performance evaluation of a solar furnace by measuring the highly concentrated solar flux

    International Nuclear Information System (INIS)

    Lee, Hyunjin; Chai, Kwankyo; Kim, Jongkyu; Lee, Sangnam; Yoon, Hwanki; Yu, Changkyun; Kang, Yongheack

    2014-01-01

    We evaluated optical performance of a solar furnace in the KIER (Korea Institute of Energy Research) by measuring the highly concentrated solar flux with the flux mapping method. We presented and analyzed optical performance in terms of concentrated solar flux distribution and power distribution. We investigated concentration ratio, stagnation temperature, total power, and concentration accuracy with help of a modeling code based on the ray tracing method and thereby compared with other solar furnaces. We also discussed flux changes by shutter opening angles and by position adjustment of reflector facets. In the course of flux analysis, we provided a better understanding of reference flux measurement for calibration, reflectivity measurement with a portable reflectometer, shadowing area consideration for effective irradiation, as well as accuracy and repeatability of flux measurements. The results in the present study will help proper utilization of a solar furnace by facilitating comparison between flux measurements at different conditions and flux estimation during operation

  9. Measurement of radon, thoron and their progeny concentrations in the dwellings of Pauri Garhwal, Uttarakhand, India

    International Nuclear Information System (INIS)

    Joshi, Veena; Bijalwan, Pramesh; Rawat, Jasbir; Yadav, Manjulata; Ramola, R.C.; Mishra, Rosaline

    2015-01-01

    It is well known that inhalation of radon, thoron and their progeny contribute more than 50% of natural background radiation dose to human being. The time integrated passive measurements of radon, thoron and their progeny concentrations were carried out in the dwellings of Pauri Garhwal, Uttarakhand, India. The measurements of radon and thoron concentrations were performed by LR-115 detector based single entry Pin-Hole dosimeter while for the measurement of progeny concentrations, LR-115 deposition based DTPS/DRPS technique was used. The experimental techniques and results obtained are discussed in detail. (author)

  10. Quantitative spatially resolved measurement of tissue chromophore concentrations using photoacoustic spectroscopy: application to the measurement of blood oxygenation and haemoglobin concentration

    Science.gov (United States)

    Laufer, Jan; Delpy, Dave; Elwell, Clare; Beard, Paul

    2007-01-01

    A new approach based on pulsed photoacoustic spectroscopy for non-invasively quantifying tissue chromophore concentrations with high spatial resolution has been developed. The technique is applicable to the quantification of tissue chromophores such as oxyhaemoglobin (HbO2) and deoxyhaemoglobin (HHb) for the measurement of physiological parameters such as blood oxygen saturation (SO2) and total haemoglobin concentration. It can also be used to quantify the local accumulation of targeted contrast agents used in photoacoustic molecular imaging. The technique employs a model-based inversion scheme to recover the chromophore concentrations from photoacoustic measurements. This comprises a numerical forward model of the detected time-dependent photoacoustic signal that incorporates a multiwavelength diffusion-based finite element light propagation model to describe the light transport and a time-domain acoustic model to describe the generation, propagation and detection of the photoacoustic wave. The forward model is then inverted by iteratively fitting it to measurements of photoacoustic signals acquired at different wavelengths to recover the chromophore concentrations. To validate this approach, photoacoustic signals were generated in a tissue phantom using nanosecond laser pulses between 740 nm and 1040 nm. The tissue phantom comprised a suspension of intralipid, blood and a near-infrared dye in which three tubes were immersed. Blood at physiological haemoglobin concentrations and oxygen saturation levels ranging from 2% to 100% was circulated through the tubes. The signal amplitude from different temporal sections of the detected photoacoustic waveforms was plotted as a function of wavelength and the forward model fitted to these data to recover the concentrations of HbO2 and HHb, total haemoglobin concentration and SO2. The performance was found to compare favourably to that of a laboratory CO-oximeter with measurement resolutions of ±3.8 g l-1 (±58 µM) and ±4

  11. Quantitative spatially resolved measurement of tissue chromophore concentrations using photoacoustic spectroscopy: application to the measurement of blood oxygenation and haemoglobin concentration

    Energy Technology Data Exchange (ETDEWEB)

    Laufer, Jan; Delpy, Dave; Elwell, Clare; Beard, Paul [Department of Medical Physics and Bioengineering, University College London, Malet Place Engineering Building, London WC1E 6BT (United Kingdom)

    2007-01-07

    A new approach based on pulsed photoacoustic spectroscopy for non-invasively quantifying tissue chromophore concentrations with high spatial resolution has been developed. The technique is applicable to the quantification of tissue chromophores such as oxyhaemoglobin (HbO{sub 2}) and deoxyhaemoglobin (HHb) for the measurement of physiological parameters such as blood oxygen saturation (SO{sub 2}) and total haemoglobin concentration. It can also be used to quantify the local accumulation of targeted contrast agents used in photoacoustic molecular imaging. The technique employs a model-based inversion scheme to recover the chromophore concentrations from photoacoustic measurements. This comprises a numerical forward model of the detected time-dependent photoacoustic signal that incorporates a multiwavelength diffusion-based finite element light propagation model to describe the light transport and a time-domain acoustic model to describe the generation, propagation and detection of the photoacoustic wave. The forward model is then inverted by iteratively fitting it to measurements of photoacoustic signals acquired at different wavelengths to recover the chromophore concentrations. To validate this approach, photoacoustic signals were generated in a tissue phantom using nanosecond laser pulses between 740 nm and 1040 nm. The tissue phantom comprised a suspension of intralipid, blood and a near-infrared dye in which three tubes were immersed. Blood at physiological haemoglobin concentrations and oxygen saturation levels ranging from 2% to 100% was circulated through the tubes. The signal amplitude from different temporal sections of the detected photoacoustic waveforms was plotted as a function of wavelength and the forward model fitted to these data to recover the concentrations of HbO{sub 2} and HHb, total haemoglobin concentration and SO{sub 2}. The performance was found to compare favourably to that of a laboratory CO-oximeter with measurement resolutions of {+-}3

  12. Quantitative spatially resolved measurement of tissue chromophore concentrations using photoacoustic spectroscopy: application to the measurement of blood oxygenation and haemoglobin concentration

    International Nuclear Information System (INIS)

    Laufer, Jan; Delpy, Dave; Elwell, Clare; Beard, Paul

    2007-01-01

    A new approach based on pulsed photoacoustic spectroscopy for non-invasively quantifying tissue chromophore concentrations with high spatial resolution has been developed. The technique is applicable to the quantification of tissue chromophores such as oxyhaemoglobin (HbO 2 ) and deoxyhaemoglobin (HHb) for the measurement of physiological parameters such as blood oxygen saturation (SO 2 ) and total haemoglobin concentration. It can also be used to quantify the local accumulation of targeted contrast agents used in photoacoustic molecular imaging. The technique employs a model-based inversion scheme to recover the chromophore concentrations from photoacoustic measurements. This comprises a numerical forward model of the detected time-dependent photoacoustic signal that incorporates a multiwavelength diffusion-based finite element light propagation model to describe the light transport and a time-domain acoustic model to describe the generation, propagation and detection of the photoacoustic wave. The forward model is then inverted by iteratively fitting it to measurements of photoacoustic signals acquired at different wavelengths to recover the chromophore concentrations. To validate this approach, photoacoustic signals were generated in a tissue phantom using nanosecond laser pulses between 740 nm and 1040 nm. The tissue phantom comprised a suspension of intralipid, blood and a near-infrared dye in which three tubes were immersed. Blood at physiological haemoglobin concentrations and oxygen saturation levels ranging from 2% to 100% was circulated through the tubes. The signal amplitude from different temporal sections of the detected photoacoustic waveforms was plotted as a function of wavelength and the forward model fitted to these data to recover the concentrations of HbO 2 and HHb, total haemoglobin concentration and SO 2 . The performance was found to compare favourably to that of a laboratory CO-oximeter with measurement resolutions of ±3.8 g l -1 (±58

  13. Interaction of thrombocytes with poly(ether imide): The influence of processing.

    Science.gov (United States)

    Braune, S; Lange, M; Richau, K; Lützow, K; Weigel, T; Jung, F; Lendlein, A

    2010-01-01

    The processing of polymers for blood contacting devices can have a major influence on surface properties. In this study, we fabricated poly(ether imide) (PEI) membranes and films to investigate the effects of the processing on physicochemical surface properties by atomic force microscopy (AFM), scanning electron microscopy, contact angle as well as zeta potential measurements. A static platelet adhesion test was performed to analyze the thrombogenicity of both devices. While contact angle measurements showed similar levels of hydrophobicity and zeta potential values were equivalent, mean surface roughness as well as surface energies in the dispersive part were found to be increased for the PEI membrane. The static platelet adhesion test showed a significantly decreased number of adherent platelets per surface area on the PEI film (178.98 ± 102.70/45000 μm2) compared to the PEI membrane (504 ± 314.27/45000μm2) and, consequently, revealed evidence for higher thrombogenicity of the PEI membrane. This study shows that processing can have a significant effect on platelet adhesion to biomaterials, even though, molar weight was identical. Thrombogenicity of polymer-based cardiovascular devices, therefore, have to be evaluated at the final product level, following the entire processing procedure.

  14. The deconvolution of sputter-etching surface concentration measurements to determine impurity depth profiles

    International Nuclear Information System (INIS)

    Carter, G.; Katardjiev, I.V.; Nobes, M.J.

    1989-01-01

    The quasi-linear partial differential continuity equations that describe the evolution of the depth profiles and surface concentrations of marker atoms in kinematically equivalent systems undergoing sputtering, ion collection and atomic mixing are solved using the method of characteristics. It is shown how atomic mixing probabilities can be deduced from measurements of ion collection depth profiles with increasing ion fluence, and how this information can be used to predict surface concentration evolution. Even with this information, however, it is shown that it is not possible to deconvolute directly the surface concentration measurements to provide initial depth profiles, except when only ion collection and sputtering from the surface layer alone occur. It is demonstrated further that optimal recovery of initial concentration depth profiles could be ensured if the concentration-measuring analytical probe preferentially sampled depths near and at the maximum depth of bombardment-induced perturbations. (author)

  15. Methods to homogenize electrochemical concentration cell (ECC ozonesonde measurements across changes in sensing solution concentration or ozonesonde manufacturer

    Directory of Open Access Journals (Sweden)

    T. Deshler

    2017-06-01

    Full Text Available Ozone plays a significant role in the chemical and radiative state of the atmosphere. For this reason there are many instruments used to measure ozone from the ground, from space, and from balloons. Balloon-borne electrochemical cell ozonesondes provide some of the best measurements of the ozone profile up to the mid-stratosphere, providing high vertical resolution, high precision, and a wide geographic distribution. From the mid-1990s to the late 2000s the consistency of long-term records from balloon-borne ozonesondes has been compromised by differences in manufacturers, Science Pump (SP and ENSCI (EN, and differences in recommended sensor solution concentrations, 1.0 % potassium iodide (KI and the one-half dilution: 0.5 %. To investigate these differences, a number of organizations have independently undertaken comparisons of the various ozonesonde types and solution concentrations, resulting in 197 ozonesonde comparison profiles. The goal of this study is to derive transfer functions to allow measurements outside of standard recommendations, for sensor composition and ozonesonde type, to be converted to a standard measurement and thus homogenize the data to the expected accuracy of 5 % (10 % in the stratosphere (troposphere. Subsets of these data have been analyzed previously and intermediate transfer functions derived. Here all the comparison data are analyzed to compare (1 differences in sensor solution composition for a single ozonesonde type, (2 differences in ozonesonde type for a single sensor solution composition, and (3 the World Meteorological Organization's (WMO and manufacturers' recommendations of 1.0 % KI solution for Science Pump and 0.5 % KI for ENSCI. From the recommendations it is clear that ENSCI ozonesondes and 1.0 % KI solution result in higher amounts of ozone sensed. The results indicate that differences in solution composition and in ozonesonde type display little pressure dependence at pressures

  16. Extraction of Mo, W and Tc with polyurethane foam and with cyclic polyether from SCN-/HC1 medium

    International Nuclear Information System (INIS)

    Caletka, R.; Hausbeck, R.; Krivan, V.

    1986-01-01

    The extraction of molybdenum, tungsten and technetium by polyether-based polyurethane foam and by a cyclic polyether from aqueous thiocyanate solutions is described. The influence of the reductants stannous chloride and ascorbic acid has also been studied. The possibilites of the polyurethane foam for preconcentration and determination of molybdenum are discussed. (author)

  17. Polyether ionophores: broad-spectrum and promising biologically active molecules for the control of drug-resistant bacteria and parasites.

    Science.gov (United States)

    Kevin Ii, Dion A; Meujo, Damaris Af; Hamann, Mark T

    2009-02-01

    As multidrug-resistant (MDR) pathogens continue to emerge, there is a substantial amount of pressure to identify new drug candidates. Carboxyl polyethers, also referred to as polyether antibiotics, are a unique class of compounds with outstanding potency against a variety of critical infectious disease targets including protozoa, bacteria and viruses. The characteristics of these molecules that are of key interest are their selectivity and high potency against several MDR etiological agents. Although many studies have been published about carboxyl polyether antibiotics, there are no recent reviews of this class of drugs. The purpose of this review is to provide the reader with an overview of the spectrum of activity of polyether antibiotics, their mechanism of action, toxicity and potential as drug candidates to combat drug-resistant infectious diseases. Polyether ionophores show a high degree of promise for the potential control of drug-resistant bacterial and parasitic infections. Despite the long history of use of this class of drugs, very limited medicinal chemistry and drug optimization studies have been reported, thus leaving the door open to these opportunities in the future. Scifinder and PubMed were the main search engines used to locate articles relevant to the topic presented in the present review. Keywords used in our search were specific names of each of the 88 compounds presented in the review as well as more general terms such as polyethers, ionophores, carboxylic polyethers and polyether antibiotics.

  18. Airborne plutonium-239 and americium-241 concentrations measured from the 125-meter Hanford Meteorological Tower

    International Nuclear Information System (INIS)

    Sehmel, G.A.

    1978-01-01

    Airborne plutonium-239 and americium-241 concentrations and fluxes were measured at six heights from 1.9 to 122 m on the Hanford meteorological tower. The data show that plutonium-239 was transported on nonrespirable and small particles at all heights. Airborne americium-241 concentrations on small particles were maximum at the 91 m height

  19. Predicting and measurement of pH of seawater reverse osmosis concentrates

    KAUST Repository

    Waly, Tarek; Kennedy, Maria Dolores; Witkamp, Geert-Jan; Amy, Gary L.; Schippers, Jan Cornelis

    2011-01-01

    The pH of seawater reverse osmosis plants (SWRO) is the most influential parameter in determining the degree of supersaturation of CaCO3 in the concentrate stream. For this, the results of pH measurements of the concentrate of a seawater reverse

  20. Variation in acrylamide concentration in French fries : effects of control measures in food service establishments

    NARCIS (Netherlands)

    Sanny, M.A.I.

    2012-01-01

    The aim of this thesis was first to identify the major technological and managerial factors and to investigate their contribution to variation in acrylamide concentrations. The second aim was to investigate the effect of technological and managerial control measures on the concentration and

  1. 40 CFR 761.298 - Decisions based on PCB concentration measurements resulting from sampling.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Decisions based on PCB concentration... Cleanup and On-Site Disposal of Bulk PCB Remediation Waste and Porous Surfaces in Accordance With § 761.61(a)(6) § 761.298 Decisions based on PCB concentration measurements resulting from sampling. (a) For...

  2. Prompt gamma-ray spectrometry for measurement of B-10 concentration in brain tissue and blood

    International Nuclear Information System (INIS)

    Nakagawa, Yoshinobu; Kitamura, Katsuji; Kobayashi, Toru; Matsumoto, Keizo; Hatanaka, Hiroshi.

    1993-01-01

    Boron-10 (B-10) concentration in the brain tissue and blood was measured continuously for 24 hours after injection of the B-10 compound in live rabbits using prompt gamma-ray spectrometry. Following injection of B-10 compound (Na 2 B 12 H 11 SH, 50mg/kg) dissolved in physiological saline, B-10 concentration was continuously measured in the brain tissue. Intermittently the concentration of B-10 in blood and cerebro-spinal fluid (CSF) was also measured. In 10 minutes after the injection of B-10 compound, the level of B-10 concentration reached the peak of 400-500 ppm in blood and 20-30 ppm in the normal brain tissue. In 60 minutes the level of B-10 concentration rapidly decreased and then a gradual decline was observed. The value was 15-30 ppm at 3 hours after injection, 5-10 ppm at 6 hours and 2-5 ppm at 24 hours in the blood. The concentration in the brain tissue was 3-8 ppm at 3 hours, 2-5 ppm at 6 hours and below 1.5 ppm at 24 hours. B-10 concentration in cerebro-spinal fluid was below 1 ppm. B-10 concentration was also measured in the brain tumor and blood in the human cases at boron neutron capture therapy (BNCT). These data studied by prompt gamma-ray spectrometry are very important and useful to decide the irradiation time. (author)

  3. Processing-independent proANP measurement for low concentrations in plasma

    DEFF Research Database (Denmark)

    Mark, Peter D; Hunter, Ingrid; Terzic, Dijana

    2018-01-01

    BACKGROUND: Decreased concentrations of pro-atrial-derived natriuretic peptides (proABP) in plasma have been associated with obesity and suggested as a predictor of type 2 diabetes. However, assays for measuring proANP are generally aimed to quantitate higher concentrations of proANP associated...

  4. Measurements of the oxidation state and concentration of plutonium in interstitial waters of the Irish Sea

    International Nuclear Information System (INIS)

    Nelson, D.M.; Lovett, M.B.

    1980-01-01

    The question of plutonium movement in interstitial waters resulting from diffusion along concentration gradients or from advective flow is addressed. The results of measurements of both the concentration and the oxidation state of plutonium in interstitial water collected from sediments near the Windscale discharge, in the solid phases of these sediments and in seawater and suspended solids collected at the coring locations are discussed

  5. Exposition by inhalation to the formaldehyde in the air. Source, measures and concentrations

    International Nuclear Information System (INIS)

    Del Gratta, F.; Durif, M.; Fagault, Y.; Zdanevitch, I.

    2004-12-01

    This document presents the main techniques today available to characterize the formaldehyde concentrations in the air for different contexts: urban and rural areas or around industrial installations but also indoor and occupational area. It provides information to guide laboratories and research departments. A synthesis gives also the main emissions sources of these compounds as reference concentrations measured in different environments. (A.L.B.)

  6. About Error in Measuring Oxygen Concentration by Solid-Electrolyte Sensors

    Directory of Open Access Journals (Sweden)

    V. I. Nazarov

    2008-01-01

    Full Text Available The paper evaluates additional errors while measuring oxygen concentration in a gas mixture by a solid-electrolyte cell. Experimental dependences of additional errors caused by changes in temperature in a sensor zone, discharge of gas mixture supplied to a sensor zone, partial pressure in the gas mixture and fluctuations in oxygen concentrations in the air.

  7. Evaluation and Comparison of Chemiluminescence and UV Photometric Methods for Measuring Ozone Concentrations in Ambient Air

    Science.gov (United States)

    The current Federal Reference Method (FRM) for measuring concentrations of ozone in ambient air is based on the dry, gas-phase, chemiluminescence reaction between ethylene (C2H4) and any ozone (O3) that may be p...

  8. Optimisation of elevated radon concentration measurement by using electro-chemical etching of nuclear track detectors

    International Nuclear Information System (INIS)

    Celikovic, I.; Ujic, P.; Fujimoto, K.; Tommasino, L.; Demajo, A.; Zunic, Z.; Celikovic, I.)

    2007-01-01

    In the paper, two methods for adjusting of passive radon-thoron discriminative dosimeters (UFO detector) for enhanced radon concentration measurement are presented. Achieved upper limit of detection is 5.94 MBq m-3 d [sr

  9. Laser-Based Optical System for Reactive Radical Concentration Measurements in Plasmas and Flames

    National Research Council Canada - National Science Library

    Fridman, Alexander

    2006-01-01

    Defense University Research Instrumentation Program (DURIP) funding was used to assemble a multi-purpose optical diagnostic system for in-situ radical concentration measurements in plasma and combustion systems...

  10. Development of automatic high-concentration boron measurement technique; Konodo hoso jido sokutei gijutsu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, T.; Honda, S.; Ito, A. [Kyushu Electric Power Co. Inc., Fukuoka (Japan)

    1997-03-01

    The technology that can automatically measure the boron concentration in boric acid water was developed. A high-concentration boric acid solution must be held at a high temperature to prevent the deposition. Skill and precision ({plus_minus}0.2 to 0.3% for 10 to 2500 ppm as boron concentration, and {plus_minus}2 to 3% for 2500 to 25,000 ppm) are required to analyze the boric acid solution manually. In theory, the boron concentration in a wide range can be measured, and boron has a constant-temperature function. A density hydrometer method that facilitates the treatment and calibration in high precision and at low cost was chosen. The vibration period generated when vibration is given to the solution specimen put in a U-tube is higher as the density is lower. On the basis of this theory, the density of a specimen can be obtained according to the relation with the same data of the known-concentration boric acid water. The high-concentration boric acid water that cannot be measured by the existing boron densitometer can be measured directly. It can also be measured in a low-concentration area. The technique can be used in a laboratory as the simplified method that is replaced by the current manual analysis. The reduction effect of analytical chemical`s waste liquid can also be expected. In the electric power industry, automated equipment is required for high efficiency and labor saving. 13 figs., 3 tabs.

  11. A research on polyether glycol replaced APCP rocket propellant

    Science.gov (United States)

    Lou, Tianyou; Bao, Chun Jia; Wang, Yiyang

    2017-08-01

    Ammonium perchlorate composite propellant (APCP) is a modern solid rocket propellant used in rocket vehicles. It differs from many traditional solid rocket propellants by the nature of how it is processed. APCP is cast into shape, as opposed to powder pressing it with black powder. This provides manufacturing regularity and repeatability, which are necessary requirements for use in the aerospace industry. For traditional APCP, ingredients normally used are ammonium peroxide, aluminum, Hydroxyl-terminated polybutadiene(HTPB), curing agency and other additives, the greatest disadvantage is that the fuel is too expensive. According to the price we collected in our country, a single kilogram of this fuel will cost 200 Yuan, which is about 35 dollars, for a fan who may use tons of the fuel in a single year, it definitely is a great deal of money. For this reason, we invented a new kind of APCP fuel. Changing adhesive agency from cross-linked htpb to cross linked polyether glycol gives a similar specific thrust, density and mechanical property while costs a lower price.

  12. Local deformation behavior of surface porous polyether-ether-ketone.

    Science.gov (United States)

    Evans, Nathan T; Torstrick, F Brennan; Safranski, David L; Guldberg, Robert E; Gall, Ken

    2017-01-01

    Surface porous polyether-ether-ketone has the ability to maintain the tensile monotonic and cyclic strength necessary for many load bearing orthopedic applications while providing a surface that facilitates bone ingrowth; however, the relevant deformation behavior of the pore architecture in response to various loading conditions is not yet fully characterized or understood. The focus of this study was to examine the compressive and wear behavior of the surface porous architecture using micro Computed Tomography (micro CT). Pore architectures of various depths (~0.5-2.5mm) and pore sizes (212-508µm) were manufactured using a melt extrusion and porogen leaching process. Compression testing revealed that the pore architecture deforms in the typical three staged linear elastic, plastic, and densification stages characteristic of porous materials. The experimental moduli and yield strengths decreased as the porosity increased but there was no difference in properties between pore sizes. The porous architecture maintained a high degree of porosity available for bone-ingrowth at all strains. Surface porous samples showed no increase in wear rate compared to injection molded samples, with slight pore densification accompanying wear. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Yessotoxins, a Group of Marine Polyether Toxins: an Overview

    Directory of Open Access Journals (Sweden)

    José J. Fernández

    2008-05-01

    Full Text Available Yessotoxin (YTX is a marine polyether toxin that was first isolated in 1986 from the scallop Patinopecten yessoensis. Subsequently, it was reported that YTX is produced by the dinoflagellates Protoceratium reticulatum, Lingulodinium polyedrum and Gonyaulax spinifera. YTXs have been associated with diarrhetic shellfish poisoning (DSP because they are often simultaneously extracted with DSP toxins, and give positive results when tested in the conventional mouse bioassay for DSP toxins. However, recent evidence suggests that YTXs should be excluded from the DSP toxins group, because unlike okadaic acid (OA and dinophyisistoxin-1 (DTX-1, YTXs do not cause either diarrhea or inhibition of protein phosphatases . In spite of the increasing number of molecular studies focused on the toxicity of YTX, the precise mechanism of action is currently unknown. Since the discovery of YTX, almost forty new analogues isolated from both mussels and dinoflagellates have been characterized by NMR or LC-MS/MS techniques. These studies indicate a wide variability in the profile and the relative abundance of YTXs in both, bivalves and dinoflagellates. This review covers current knowledge on the origin, producer organisms and vectors, chemical structures, metabolism, biosynthetic origin, toxicological properties, potential risks to human health and advances in detection methods of YTXs.

  14. High Resolution Mass Spectrometry of Polyfluorinated Polyether-Based Formulation

    Science.gov (United States)

    Dimzon, Ian Ken; Trier, Xenia; Frömel, Tobias; Helmus, Rick; Knepper, Thomas P.; de Voogt, Pim

    2016-02-01

    High resolution mass spectrometry (HRMS) was successfully applied to elucidate the structure of a polyfluorinated polyether (PFPE)-based formulation. The mass spectrum generated from direct injection into the MS was examined by identifying the different repeating units manually and with the aid of an instrument data processor. Highly accurate mass spectral data enabled the calculation of higher-order mass defects. The different plots of MW and the nth-order mass defects (up to n = 3) could aid in assessing the structure of the different repeating units and estimating their absolute and relative number per molecule. The three major repeating units were -C2H4O-, -C2F4O-, and -CF2O-. Tandem MS was used to identify the end groups that appeared to be phosphates, as well as the possible distribution of the repeating units. Reversed-phase HPLC separated of the polymer molecules on the basis of number of nonpolar repeating units. The elucidated structure resembles the structure in the published manufacturer technical data. This analytical approach to the characterization of a PFPE-based formulation can serve as a guide in analyzing not just other PFPE-based formulations but also other fluorinated and non-fluorinated polymers. The information from MS is essential in studying the physico-chemical properties of PFPEs and can help in assessing the risks they pose to the environment and to human health.

  15. Uranium complexes with macrosyclic polyethers. Synthesis and structural chemical analysis

    International Nuclear Information System (INIS)

    Elbasyouny, A.

    1983-01-01

    This dissertation reports about studies on the chemical coordination behaviour of uranium of oxidation stages IV and VI with regard to twelve different macrocyclic ligands. For the preparation of the complexes, for every system a different method has been developed. The elementary analysis of the various complexes including the uranium had been done by X-ray fluorescence analysis, and the structural characterization proceeded via vibrational, uv-vis and emission spectroscopy as well as 1 H-NMR and 13 C-spin-lattice relaxation time studies. Conformational analysis of the polyethers used allowed the structural changes in the complexes to be observed. The structural analysis of the hydrous uranium VI crown ether complexes yielded information of characteristic features of these types of complexes. The first coordination sphere of the uranyl ion with covalently bonded anion remains unchanged. As to the water content, there is a certain range. Depending upon the solvent used, the complexes have two or four H 2 O molecules per formula unit. (orig./EF) [de

  16. Estimation of release of tritium from measurements of air concentrations in reactor building of PHWR

    International Nuclear Information System (INIS)

    Purohit, R.G.; Sarkar, P.K.

    2010-01-01

    In this paper an attempt has been made to estimate the releases from measured air concentrations of tritium at various locations in Reactor Building (RB). Design data of Kaiga Generating Station and sample measurements of tritium concentrations at various locations in RB and discharges for a period of fortnight were used. A comparison has also been made with actual measurements. It has been observed that there is good matching in estimated and actual measurements of tritium release on some days while on some days there is high difference

  17. Fine particle number and mass concentration measurements in urban Indian households.

    Science.gov (United States)

    Mönkkönen, P; Pai, P; Maynard, A; Lehtinen, K E J; Hämeri, K; Rechkemmer, P; Ramachandran, G; Prasad, B; Kulmala, M

    2005-07-15

    Fine particle number concentration (D(p)>10 nm, cm(-3)), mass concentrations (approximation of PM(2.5), microg m(-3)) and indoor/outdoor number concentration ratio (I/O) measurements have been conducted for the first time in 11 urban households in India, 2002. The results indicate remarkable high indoor number and mass concentrations and I/O number concentration ratios caused by cooking. Besides cooking stoves that used liquefied petroleum gas (LPG) or kerosene as the main fuel, high indoor concentrations can be explained by poor ventilation systems. Particle number concentrations of more than 300,000 cm(-3) and mass concentrations of more than 1000 microg m(-3) were detected in some cases. When the number and mass concentrations during cooking times were statistically compared, a correlation coefficient r>0.50 was observed in 63% of the households. Some households used other fuels like wood and dung cakes along with the main fuel, but also other living activities influenced the concentrations. In some areas, outdoor combustion processes had a negative impact on indoor air quality. The maximum concentrations observed in most cases were due to indoor combustion sources. Reduction of exposure risk and health effects caused by poor indoor air in urban Indian households is possible by improving indoor ventilation and reducing penetration of outdoor particles.

  18. Whispering Gallery Mode Based Optical Fiber Sensor for Measuring Concentration of Salt Solution

    Directory of Open Access Journals (Sweden)

    Chia-Chin Chiang

    2013-01-01

    Full Text Available An optical fiber solution-concentration sensor based on whispering gallery mode (WGM is proposed in this paper. The WGM solution-concentration sensors were used to measure salt solutions, in which the concentrations ranged from 1% to 25% and the wavelength drifted from the left to the right. The experimental results showed an average sensitivity of approximately 0.372 nm/% and an R2 linearity of 0.8835. The proposed WGM sensors are of low cost, feasible for mass production, and durable for solution-concentration sensing.

  19. Determination of potassium concentration in salt water for residual beta radioactivity measurements

    International Nuclear Information System (INIS)

    Suarez-Navarro, J.A.; Pujol, Ll.

    2004-01-01

    High interferences may arise in the determination of potassium concentration in salt water. Several analytical methods were studied to determine which method provided the most accurate measurements of potassium concentration. This study is relevant for radiation protection because the exact amount of potassium in water samples must be known for determinations of residual beta activity concentration. The fitting algorithm of the calibration curve and estimation of uncertainty in potassium determinations were also studied. The reproducibility of the proposed analytical method was tested by internal and external validation. Furthermore, the residual beta activity concentration of several Spanish seawater and brackish river water samples was determined using the proposed method

  20. Synthesis and Crosslinking of Polyether-Based Main Chain Benzoxazine Polymers and Their Gas Separation Performance

    Directory of Open Access Journals (Sweden)

    Muntazim Munir Khan

    2018-02-01

    Full Text Available The poly(ethylene glycol-based benzoxazine polymers were synthesized via a polycondensation reaction between Bisphenol-A, paraformaldehyde, and poly(ether diamine/(Jeffamine®. The structures of the polymers were confirmed by proton nuclear magnetic resonance spectroscopy (1H-NMR, indicating the presence of a cyclic benzoxazine ring. The polymer solutions were casted on the glass plate and cross-linked via thermal treatment to produce tough and flexible films without using any external additives. Thermal properties and the crosslinking behaviour of these polymers were studied by thermogravimetric analysis (TGA and differential scanning calorimetry (DSC. Single gas (H2, O2, N2, CO2, and CH4 transport properties of the crosslinked polymeric membranes were measured by the time-lag method. The crosslinked PEG-based polybenzoxazine membranes show improved selectivities for CO2/N2 and CO2/CH4 gas pairs. The good separation selectivities of these PEG-based polybenzoxazine materials suggest their utility as efficient thin film composite membranes for gas and liquid membrane separation technology.

  1. Extraction of trivalent lanthanides and actinides by a synergistic mixture of thenoyltrifluoroacetone and a linear polyether

    International Nuclear Information System (INIS)

    Ensor, D.D.; Shah, A.H.

    1984-01-01

    Mixtures of a two component system, a linear polyether, 1,13-bis[8-quinolyl]-1,4,7,10,13-pentaoxatridecane, K-5, and thenoyltrifluoroacetone, HTTA, have been shown to exhibit synergistic character in the extraction of trivalent lanthanides and actinides. The effect of the addition of K-5 to the organic phase on the extractions of Ce(III), Eu(III), Tm(III), Am(III), Cm(III), Bk(III), and Cf(III) by HTTA in chloroform from 0.5M NaNO 3 at 25 0 C has been measured. These results indicate the extraction is enhanced by the formation of M(TTA) 3 K-5 adduct in the organic phase. The organic phase stability constants for the formation of these synergistic species have been calculated for all the metals studied. The magnitude of these organic phase stability constants for K-5 are similar to other common neutral donors. The order of stability does not follow the normal trend based on charge-to-radius ratio, but follows a pattern based on size, with Am(III) being the most stable

  2. The Effect of Core and Veneering Design on the Optical Properties of Polyether Ether Ketone.

    Science.gov (United States)

    Zeighami, S; Mirmohammadrezaei, S; Safi, M; Falahchai, S M

    2017-12-01

    This study aimed to evaluate the effect of core shade and core and veneering thickness on color parameters and translucency of polyether ether ketone (PEEK). Sixty PEEK discs (0.5 and 1 mm in thickness) with white and dentine shades were veneered with A2 shade indirect composite resin with 0.5, 1 and 1.5 mm thickness (n=5). Cores without the veneering material served as controls for translucency evaluation. Color parameters were measured by a spectroradiometer. Color difference (ΔE₀₀) and translucency parameters (TP) were computed. Data were analyzed using one-way ANOVA and Tukey's test (for veneering thickness) and independent t-test (for core shade and thickness) via SPSS 20.0 (p⟨0.05). Regarding the veneering thickness, white cores of 0.5 mm thickness showed significant differences in all color parameters. In white cores of 1 mm thickness and dentine cores of 0.5 and 1 mm thickness, there were statistically significant differences only in L∗, a∗ and h∗. The mean TP was significantly higher in all white cores of 1 mm thickness than dentine cores of 1 mm. Considering ΔE₀₀=3.7 as clinically unacceptable, only three groups had higher mean ΔE₀₀ values. Core shade, core thickness, and the veneering thickness affected the color and translucency of PEEK restorations. Copyright© 2017 Dennis Barber Ltd.

  3. Differential Mueller matrix polarimetry technique for non-invasive measurement of glucose concentration on human fingertip.

    Science.gov (United States)

    Phan, Quoc-Hung; Lo, Yu-Lung

    2017-06-26

    A differential Mueller matrix polarimetry technique is proposed for obtaining non-invasive (NI) measurements of the glucose concentration on the human fingertip. The feasibility of the proposed method is demonstrated by detecting the optical rotation angle and depolarization index of tissue phantom samples containing de-ionized water (DI), glucose solutions with concentrations ranging from 0~500 mg/dL and 2% lipofundin. The results show that the extracted optical rotation angle increases linearly with an increasing glucose concentration, while the depolarization index decreases. The practical applicability of the proposed method is demonstrated by measuring the optical rotation angle and depolarization index properties of the human fingertips of healthy volunteers.

  4. Chromatographic method of measurement of helium concentration in underground waters for dating in hydrological questions

    International Nuclear Information System (INIS)

    Najman, J.

    2008-04-01

    Research methods which use natural environmental indicators are widely applied in hydrology. Different concentrations of indicators and their isotopic components in ground waters allow to determine the genesis of waters and are valuable source of information about the water flow dynamics. One of the significant indicator is helium. The concentration of 4 He (helium) in ground water is a fine indicator in water dating in a range from a hundreds to millions of years (Aeschbach-Hertig i in., 1999; Andrews i in., 1989; Castro i in., 2000; Zuber i in., 2007). 4 He is also used for dating young waters of age about 10 years (Solomon i in., 1996). Thesis consist the description of elaborated in IFJ PAN in Krakow chromatographic measurement method of helium concentration in ground waters in aim of dating. Chapter 1 contain short introduction about ground water dating and chapter 2 description of helium property and chosen applications of helium for example in technology and earthquake predictions. Helium sources in ground waters are described in chapter 3. Helium concentration in water after infiltration (originated from atmosphere) to the ground water system depends mainly on the helium concentration coming from the equilibration with the atmosphere increased by additional concentration from '' excess air ''. With the increasing resistance time of ground water during the flow, radiogenic, non-atmospheric component of helium dissolves also in water. In chapter 4 two measurement methods of helium concentration in ground waters were introduced: mass spectrometric and gas chromatographic method. Detailed description of elaborated chromatographic measurement method of helium concentration in ground water contain chapter 5. To verify developed method the concentration of helium in ground waters from the regions of Krakow and Busko Zdroj were measured. For this waters the concentrations of helium are known from the earlier mass spectrometric measurements. The results of

  5. Development of concentration measurement system in a mini-channel using a local NMR sensor

    International Nuclear Information System (INIS)

    Ogawa, Kuniyasu; Haishi, Tomoyuki

    2008-01-01

    A local NMR sensor to measure methanol concentration of fluid flowing in a mini-channel was developed. The principle of the methanol sensor is based on the chemical shift of CH and OH species under high magnetic field. The sensor consists of a planar surface coil of 0.60 mm inside diameter. Using the sensors, local methanol concentration of water-methanol mixture in the mini-channel of 3.0 mm width and 1.5 mm depth was measured. The effects of flow velocity in the channel and the gravity direction on the methanol concentration distribution in the channel were investigated experimentally. (author)

  6. ESR measurement of the concentration of vibrationally excited hydrogen and deuterium molecules

    International Nuclear Information System (INIS)

    Gershenzon, Yu.M.; Ivanov, A.V.; Il'in, S.D.; Kucheryavyi, S.I.; Rozenshtein, V.B.

    1988-01-01

    A method is described for measuring the concentration of vibrationally excited H 2 and D 2 molecules using an ESR microwave spectrometer. The essence of the method is the titration of H 2 (v = 1) and D 2 (v = 1) with D and H atoms and measurement of the concentrations of the titration products H and D, respectively. Stoichiometric titration coefficients were determined in the form of proportionality coefficients between the titration signals Δ[H], Δ[D] and the concentrations of H 2 (v = 1), D 2 (v = 1)

  7. Measurement of Radon concentration in groundwater by technique of nuclear track detector

    International Nuclear Information System (INIS)

    Trinh Van Giap; Nguyen Manh Hung; Dang Duc Nhan

    2000-01-01

    A method for measuring radon concentration in groundwater using nuclear track detector LR-115 stripping is reported. The radon-monitoring device in groundwater is a small box with two pieces of nuclear track detector and all these materials is placed in a plastic bag made by polyethylene. It is very suitable to measure radon concentration in groundwater well in long term. Alpha tracks produced by radon and it daughter on nuclear track detector is counted automatically by spark counting method. The paper also presents some results of radon concentration in some groundwater well and mineral water sources. (author)

  8. Results of long-term measurement of 222Rn concentrations in outdoor atmosphere

    International Nuclear Information System (INIS)

    Holy, K.; Boehm, R.; Polaskova, A.; Hola, O.

    1998-01-01

    Results are reported of the authors' long-term measurement of 222 Rn concentrations in the outdoor atmosphere. The measurements started in 1987 and were performed at a height of 1.5 m over a grass-covered ground surface, using till 1991 a Lucas type scintillation chamber and later a large volume scintillation chamber. Graphs are presented and discussed of the course of average monthly radon concentration in 1987-1996 and of annual courses of radon concentration for different time intervals of the day over 1991 to 1995. (A.K.)

  9. Measurement of 222Rn concentration in drinking water in the environs of Thirthahalli taluk, Karnataka, India

    Directory of Open Access Journals (Sweden)

    G.M. Shilpa

    2017-07-01

    Full Text Available The dissolved radon concentration in water samples collected from various aquifers in and around Thirthahalli taluk was measured by employing active technique through Scintillation Radon Monitoring system. The measured radon concentration lies in the range of 0.37 ± 0.05 Bq/l to 87.02 ± 2.11 Bq/l. The resulting annual effective radiation dose to the public, who consume this water, lies in the range of 1.01μSvy−1 to 237.56 μSvy−1. However, no significant change in the radon concentration with respect to seasonal variation was observed in majority of the sample. Few samples show higher radon concentration during summer season and lower concentration in rainy season. All these results are presented in this paper.

  10. Study of carrier concentration in single InP nanowires by luminescence and Hall measurements

    International Nuclear Information System (INIS)

    Lindgren, David; Hultin, Olof; Heurlin, Magnus; Storm, Kristian; Borgström, Magnus T; Samuelson, Lars; Gustafsson, Anders

    2015-01-01

    The free electron carrier concentrations in single InP core–shell nanowires are determined by micro-photoluminescence, cathodoluminescence (CL) and Hall effect measurements. The results from luminescence measurements were obtained by solving the Fermi–Dirac integral, as well as by analyzing the peak full width at half maximum (FWHM). Furthermore, the platform used for Hall effect measurements, combined with spot mode CL spectroscopy, is used to determine the carrier concentrations at specific positions along single nanowires. The results obtained via luminescence measurements provide an accurate and rapid feedback technique for the epitaxial development of doping incorporation in nanowires. The technique has been employed on several series of samples in which growth parameters, such as V/III-ratio, temperature and dopant flows, were investigated in an optimization procedure. The correlation between the Hall effect and luminescence measurements for extracting the carrier concentration of different samples were in excellent agreement. (paper)

  11. A comparison of the accuracy of polyether, polyvinyl siloxane, and plaster impressions for long-span implant-supported prostheses.

    Science.gov (United States)

    Hoods-Moonsammy, Vyonne J; Owen, Peter; Howes, Dale G

    2014-01-01

    The purpose of this study was to compare the capacity of different impression materials to accurately reproduce the positions of five implant analogs on a master model by comparing the resulting cast with the stainless steel master model. The study was motivated by the knowledge that distortions can occur during impression making and the pouring of casts and that this distortion may produce inaccuracies of subsequent restorations, especially long-span castings for implant superstructures. The master model was a stainless steel model with five implant analogs. The impression materials used were impression plaster (Plastogum, Harry J Bosworth), a polyether (Impregum Penta, 3M ESPE), and two polyvinyl siloxane (PVS) materials (Aquasil Monophase and Aquasil putty with light-body wash, Dentsply). Five impressions were made with each impression material and cast in die stone under strictly controlled laboratory conditions. The positions of the implants on the master model, the impression copings, and the implant analogs in the subsequent casts were measured using a coordinate measuring machine that measures within 4 μm of accuracy. Statistical analyses indicated that distortion occurred in all of the impression materials, but inconsistently. The PVS monophase material reproduced the master model most accurately. Although there was no significant distortion between the impressions and the master model or between the impressions and their casts, there were distortions between the master model and the master casts, which highlighted the cumulative effects of the distortions. The polyether material proved to be the most reliable in terms of predictability. The impression plaster displayed cumulative distortion, and the PVS putty with light body showed the least reliability. Some of the distortions observed are of clinical significance and likely to contribute to a lack of passive fit of any superstructure. The inaccuracy of these analog materials and procedures suggested

  12. Sequential Measurement of Intermodal Variability in Public Transportation PM2.5 and CO Exposure Concentrations.

    Science.gov (United States)

    Che, W W; Frey, H Christopher; Lau, Alexis K H

    2016-08-16

    A sequential measurement method is demonstrated for quantifying the variability in exposure concentration during public transportation. This method was applied in Hong Kong by measuring PM2.5 and CO concentrations along a route connecting 13 transportation-related microenvironments within 3-4 h. The study design takes into account ventilation, proximity to local sources, area-wide air quality, and meteorological conditions. Portable instruments were compacted into a backpack to facilitate measurement under crowded transportation conditions and to quantify personal exposure by sampling at nose level. The route included stops next to three roadside monitors to enable comparison of fixed site and exposure concentrations. PM2.5 exposure concentrations were correlated with the roadside monitors, despite differences in averaging time, detection method, and sampling location. Although highly correlated in temporal trend, PM2.5 concentrations varied significantly among microenvironments, with mean concentration ratios versus roadside monitor ranging from 0.5 for MTR train to 1.3 for bus terminal. Measured inter-run variability provides insight regarding the sample size needed to discriminate between microenvironments with increased statistical significance. The study results illustrate the utility of sequential measurement of microenvironments and policy-relevant insights for exposure mitigation and management.

  13. The characters of self-assembly core/shell nanoparticles of amphiphilic hyperbranched polyethers as drug carriers

    International Nuclear Information System (INIS)

    Ajun Wan; Yuxia, Kou

    2008-01-01

    The characters of self-assembly core/shell nanoparticles of amphiphilic hyperbranched polyethers (HP-g-PEO) as drug carriers were investigated. The HP-g-PEO consisting of hydrophobic HP-g-PEO core and hydrophilic poly(ethylene glycol) arms was prepared by the cation ring-opening polymerization. A series of HP-g-PEO samples with different degree of branching (DB) were synthesized under various reaction temperatures. Nanoparticles (NP) were obtained by self-assembly of HP-g-PEO in aqueous media. The structure of resulting HP-g-PEO was characterized by IR, 13 CNMR and GPC. Dynamic light scattering and transmission electron microscopy were applied to characterize the sizes and size distributions of NP. The results demonstrated that the mean diameters of NP were less than 100 nm, which exhibited uniform spherical formations and narrow size distributions. Using hydrophobic drug Probucol (PRO) as model drug, the particle sizes of drug loaded NP were larger than relative blank NP. The drug loading efficiency (LE) and incorporation efficiency (IE) of these NP were achieved to 35 and 89%, respectively. The in vitro release of PRO from the NP exhibited a sustained release and the cumulative drugs released for more than 600 h. The most important factor to affect drug release was the value of DB of HP-g-PEO. With the DB of HP-g-PEO increasing, the size and size distribution of NP decreased as well as the release rate. However, the small DB was beneficial to the LE of NP. Nanoparticle size and size distribution, LE, IE, and drug release rate were slightly affected by the initial solution concentration of polyethers. The co-incorporated hydrophilic drug had influence slightly on the release of drug from drug loaded NP. The results of in vitro drug release suggested that the core/shell NP performed good controlled release behaviors with potential practice as novelty drug delivery vehicles

  14. The measurement of thoron concentrations in Australia using the Japanese passive R-T dosimeter

    International Nuclear Information System (INIS)

    Toussaint, L.F.; Tokonami, S.; Doi, M.; Solomon, S.B.; Peggie, J.R.

    1998-01-01

    Previous studies have shown higher gamma radiation levels and higher soil thorium concentrations in the Darling Scarp area to the east of the city of Perth in Western Australia. It was considered desirable to measure the concentrations of the 220 Rn (thoron) in houses built near such areas and compare these measurements with similar measurements at other sites within Australia. A monitor developed for surveying 220 Rn and 222 Rn levels in Japan was considered most suitable for this purpose. The monitor used for the survey was a passive radon-thoron discriminative dosimeter, similar in type to that used to measure thoron concentrations in traditional Japanese houses. Houses for this study were selected from areas in the Darling Scarp. To provide data on what might be considered typical thoron concentrations associated with other soil types within Australia, a small number of houses in areas on the coastal plain of Western Australia and from the coastal areas of Victoria were also monitored. The mean thoron concentration in homes on the Darling Scarp of 14.0 Bq.m -3 was higher than that in the coastal plain in Western Australia (3.0 Bq.m -3 ) but comparable to the measurements in Victoria (11.3 Bq.m -3 ). For the radon measurements in homes, the mean Scarp concentration was typically 49.2 Bq.m -3 while the WA coastal plain and in Victoria mean concentrations were 11.6 Bq.m -3 and 15.4 Bq.m -3 respectively. For outdoors in the Darling Scarp, the thoron mean was 76.3 Bq.m -3 while the radon level was 18.2 Bq.m -3 . These measurements would suggest that the source of the thoron in homes on the Scarp is from the underlying soil rather than from the building materials. (author)

  15. Studies on measurement of chloride ion concentration in concrete structures with long-period grating sensors

    Science.gov (United States)

    Tang, Jaw-Luen; Chiang, Tsung-Yu; Chang, Hsiang-Ping; Wang, Jian-Neng

    2006-03-01

    We report the development and demonstration of a simple and low-cost long-period grating (LPG) sensor for chloride ion concentration measurement in concrete structures. The LPG sensor is extremely sensitive to the refractive index of the medium surrounding the cladding surface of the sensing grating, thus allowing it to be used as an ambient index sensor or chemical concentration indicator with high stability and reliability. We have measured chloride ion levels in a concrete sample immersed in salt water solution with different weight concentration ranging from 0 % to 20 %, and results showed that the LPG sensor exhibited a linear decrease in the transmission loss and resonance wavelength shift when the concentration increased. The measurement accuracy for concentration of salt in water solution is estimated to be 0.6 % and the limit of detection for chloride ion is about 0.04 %. To further enhance its sensitivity for chloride concentrations, we have coated gold nanoparticles on the grating surface of the LPG sensor. The sensing mechanism is based on the sensitivity of localized surface plasmon resonance of self-assembled Au colloids on the grating portion of the LPG. With this method, a factor of two increases in sensitivity of detecting chemical solution concentrations was obtained. The advantage of this type of the sensor is relatively simple of construction and ease of use. Moreover, the sensor has the potential capability for on-site, in vivo, and remote sensing, and has the potential use for disposable sensors.

  16. Epoxide-Opening Cascades in the Synthesis of Polycyclic Polyether Natural Products

    Science.gov (United States)

    2009-01-01

    The group of polycyclic polyether natural products is of special interest due to the fascinating structure and biological effects displayed by its members. The latter includes potentially therapeutic antibiotic, antifungal, and anticancer properties, as well as extreme lethality. The polycyclic structural features of this family can, in some cases, be traced to their biosynthetic origin, but in others that are less well understood, only to proposed biosynthetic pathways that feature dramatic, yet speculative, epoxide–opening cascades. In this review we summarize how such epoxide–opening cascade reactions have been used in the synthesis of polycyclic polyethers and related natural products. PMID:19572302

  17. Radiation effect of polyether-urethane under action of different ionizing radiation

    International Nuclear Information System (INIS)

    Huang Wei; Chen Xiaojun; Gao Xiaoling; Xu Yunshu; Fu Yibei

    2006-01-01

    The research concerns in the radiation effect of γ-ray and electron beam on polyether-urethane. The thermal property and radical intensity were determined by differential thermal gravimetric analysis and electron spin resonance. The composition and content of gas products from samples irradiated by different ionizing radiation were analyzed by gas chromatography. The action mechanism of these two radiation resources of γ-ray and electron beam are same, but the means of energy deposit is different. It results in the differences of radical intensity and the thermal property of polyether-urethane as well as its gas products from the radiation decomposition. (authors)

  18. A thin film degradation study of a fluorinated polyether liquid lubricant using an HPLC method

    Science.gov (United States)

    Morales, W.

    1986-01-01

    A High Pressure Liquid Chromatography (HPLC) separation method was developed to study and analyze a fluorinated polyether fluid which is promising liquid lubricant for future applications. This HPLC separation method was used in a preliminary study investigating the catalytic effect of various metal, metal alloy, and ceramic engineering materials on the degradation of this fluid in a dry air atmosphere at 345 C. Using a 440 C stainless steel as a reference catalytic material it was found that a titanium alloy and a chromium plated material degraded the fluorinated polyether fluid substantially more than the reference material.

  19. Measurements and predictors of on-road ultrafine particle concentrations and associated pollutants in Los Angeles

    Energy Technology Data Exchange (ETDEWEB)

    Fruin, S. [California Air Resources Board, Sacramento (United States); University of Southern California, Los Angeles (United States). Keck School of Medicine, Department of Preventive Medicine; Westerdahl, D.; Sax, T. [California Air Resources Board, Sacramento (United States); Sioutas, C. [University of Southern California, Los Angeles (United States). Civil and Environmental Engineering; Fine, P.M. [University of Southern California, Los Angeles (United States). Civil and Environmental Engineering; South Coast Air Quality Management District, Diamond Bar, CA (United States)

    2008-01-15

    Motor vehicles are the dominant source of oxides of nitrogen (NO{sub x}), particulate matter(PM), and certain air toxics (e.g., benzene, 1,3-butadiene) in urban areas. On roadways, motor vehicle-related pollutant concentrations are typically many times higher than ambient concentrations. Due to high air exchange rates typical of moving vehicles, this makes time spent in vehicles on roadways a major source of exposure. This paper presents on-road measurements for Los Angeles freeways and arterial roads taken from a zero-emission electric vehicle outfitted with real-time instruments. The objective was to characterize air pollutant concentrations on roadways and identify the factors associated with the highest concentrations. Our analysis demonstrated that on freeways, concentrations of ultrafine particles (UFPs), black carbon, nitric oxide, and PM-bound polycyclic aromatic hydrocarbons (PM-PAH) are generated primarily by diesel-powered vehicles, despite the relatively low fraction ({approx}6%) of diesel-powered vehicles on Los Angeles freeways. However, UFP concentrations on arterial roads appeared to be driven primarily by proximity to gasoline-powered vehicles undergoing hard accelerations. Concentrations were roughly one-third of those on freeways. By using a multiple regression model for the freeway measurements, we were able to explain 60-70% of the variability in concentrations of UFP, black carbon, nitric oxide, and PM-PAH using measures of diesel truck density and hour of day (as an indicator of wind speed). Freeway concentrations of these pollutants were also well correlated wth readily available annual average daily truck counts, potentially allowing improved population exposure estimates for epidemiology studies. Based on these roadway measurements and average driving time, it appears that 33-45% of total UFP exposure for Los Angeles residents occurs due to time spent traveling in vehicles. (author)

  20. Measurements and predictors of on-road ultrafine particle concentrations and associated pollutants in Los Angeles

    International Nuclear Information System (INIS)

    Fruin, S.; Sioutas, C.

    2008-01-01

    Motor vehicles are the dominant source of oxides of nitrogen (NO x ), particulate matter(PM), and certain air toxics (e.g., benzene, 1,3-butadiene) in urban areas. On roadways, motor vehicle-related pollutant concentrations are typically many times higher than ambient concentrations. Due to high air exchange rates typical of moving vehicles, this makes time spent in vehicles on roadways a major source of exposure. This paper presents on-road measurements for Los Angeles freeways and arterial roads taken from a zero-emission electric vehicle outfitted with real-time instruments. The objective was to characterize air pollutant concentrations on roadways and identify the factors associated with the highest concentrations. Our analysis demonstrated that on freeways, concentrations of ultrafine particles (UFPs), black carbon, nitric oxide, and PM-bound polycyclic aromatic hydrocarbons (PM-PAH) are generated primarily by diesel-powered vehicles, despite the relatively low fraction (∼6%) of diesel-powered vehicles on Los Angeles freeways. However, UFP concentrations on arterial roads appeared to be driven primarily by proximity to gasoline-powered vehicles undergoing hard accelerations. Concentrations were roughly one-third of those on freeways. By using a multiple regression model for the freeway measurements, we were able to explain 60-70% of the variability in concentrations of UFP, black carbon, nitric oxide, and PM-PAH using measures of diesel truck density and hour of day (as an indicator of wind speed). Freeway concentrations of these pollutants were also well correlated wth readily available annual average daily truck counts, potentially allowing improved population exposure estimates for epidemiology studies. Based on these roadway measurements and average driving time, it appears that 33-45% of total UFP exposure for Los Angeles residents occurs due to time spent traveling in vehicles. (author)

  1. Measurements and predictors of on-road ultrafine particle concentrations and associated pollutants in Los Angeles

    Science.gov (United States)

    Fruin, S.; Westerdahl, D.; Sax, T.; Sioutas, C.; Fine, P. M.

    Motor vehicles are the dominant source of oxides of nitrogen (NO x), particulate matter (PM), and certain air toxics (e.g., benzene, 1,3-butadiene) in urban areas. On roadways, motor vehicle-related pollutant concentrations are typically many times higher than ambient concentrations. Due to high air exchange rates typical of moving vehicles, this makes time spent in vehicles on roadways a major source of exposure. This paper presents on-road measurements for Los Angeles freeways and arterial roads taken from a zero-emission electric vehicle outfitted with real-time instruments. The objective was to characterize air pollutant concentrations on roadways and identify the factors associated with the highest concentrations. Our analysis demonstrated that on freeways, concentrations of ultrafine particles (UFPs), black carbon, nitric oxide, and PM-bound polycyclic aromatic hydrocarbons (PM-PAH) are generated primarily by diesel-powered vehicles, despite the relatively low fraction (˜6%) of diesel-powered vehicles on Los Angeles freeways. However, UFP concentrations on arterial roads appeared to be driven primarily by proximity to gasoline-powered vehicles undergoing hard accelerations. Concentrations were roughly one-third of those on freeways. By using a multiple regression model for the freeway measurements, we were able to explain 60-70% of the variability in concentrations of UFP, black carbon, nitric oxide, and PM-PAH using measures of diesel truck density and hour of day (as an indicator of wind speed). Freeway concentrations of these pollutants were also well correlated with readily available annual average daily truck counts, potentially allowing improved population exposure estimates for epidemiology studies. Based on these roadway measurements and average driving time, it appears that 33-45% of total UFP exposure for Los Angeles residents occurs due to time spent traveling in vehicles.

  2. K-edge x-ray fluorescence analysis for actinide and heavy elements solution concentration measurements

    International Nuclear Information System (INIS)

    Camp, D.C.

    1984-07-01

    Advantages of using Co-57 as an exciter for K XRFA include: a compact design that requires no x-ray tubes; the exciter-detector assembly locates remote from support electronics; on-line, at-line, or off-line configurations for monitor/measurements; systems that can be run by semi-skilled technicians, once programmed; and operated via remote terminals with results sent to control rooms; heavy element concentrations that are measurable thru industrial pipes; independent of minor changes in solution matrix or source half life with concentration results reported in near-real-time; a dynamic range of measurable concentrations that is greater than 10 4 ; measurement times that are reasonable even at 1 gram/liter; and for nuclear safeguards, it provides the <0.5% accuracy required by DOE for the accountability of U, Pu, or both, once the system is calibrated

  3. Accurate measurement of indoor radon concentration using a low-effective volume radon monitor

    International Nuclear Information System (INIS)

    Tanaka, Aya; Minami, Nodoka; Mukai, Takahiro; Yasuoka, Yumi; Iimoto, Takeshi; Omori, Yasutaka; Nagahama, Hiroyuki; Muto, Jun

    2017-01-01

    AlphaGUARD is a low-effective volume detector and one of the most popular portable radon monitors which is currently available. This study investigated whether AlphaGUARD can accurately measure the variable indoor radon levels. The consistency of the radon-concentration data obtained by AlphaGUARD is evaluated against simultaneous measurements by two other monitors (each ∼10 times more sensitive than AlphaGUARD). When accurately measuring radon concentration with AlphaGUARD, we found that the net counts of the AlphaGUARD were required of at least 500 counts, <25% of the relative percent difference. AlphaGUARD can provide accurate measurements of radon concentration for the world average level (∼50 Bq m -3 ) and the reference level of workplace (1000 Bq m -3 ), using integrated data over at least 3 h and 10 min, respectively. (authors)

  4. The boron concentration measurement by the prompt gamma-ray analysis device at JRR-4

    International Nuclear Information System (INIS)

    Hori, N.; Torii, Y.; Yamamoto, K.; Kishi, T.; Takada, J.

    2000-01-01

    In determining the dose for BNCT, it is important to measure the boron concentration in blood as well as the thermal neutron fluence. To attain an accurate measurement of the boron concentration in the whole blood at about 30 ppm, the Prompt Gamma-ray Analysis (PGA) is adopted to enable the measurement with a high degree of accuracy in short time, since the chemical analysis technique has some difficulties on it. In order to install the PGA device in a swimming pool type research reactor JRR-4, the super-mirror for obtaining the necessary neutron flux in the space over the pool surface was perpendicularly placed, because the reactor had no horizontal experiment tube for this kind of use. As the accurate measurement of the boron concentration in whole blood using PGA is enabled herewith, the first medical irradiation for BNCT at JRR-4 was carried out on October 25, 1999. (author)

  5. 41Ar-concentration measurements at the Finnish TRIGA Mark II

    International Nuclear Information System (INIS)

    Tamminen, A.

    1970-01-01

    41 Ar-concentrations in the reactor hall and in the Ar-ventilation duct of FiR-1 (IRIGA Mark II, 250 kW) have been measured during normal operation conditions. Additional measurements have been performed varying Ar-ventilation and hall ventilation flow. A γ- and background compensated thin window proportional detector and a β-Geiger detector for 41 Ar-measurements are described. The hall concentration has also been estimated from background measurements with an unshielded Ge(Li)-detector. The saturation concentration in the reactor hall with and without the hall ventilation is about 1 x 10 -7 μCi/cm 3 and 3 x 10 -7 μCi/cm 3 , respectively. (author)

  6. Estimation of Uncertainty in Aerosol Concentration Measured by Aerosol Sampling System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Chan; Song, Yong Jae; Jung, Woo Young; Lee, Hyun Chul; Kim, Gyu Tae; Lee, Doo Yong [FNC Technology Co., Yongin (Korea, Republic of)

    2016-10-15

    FNC Technology Co., Ltd has been developed test facilities for the aerosol generation, mixing, sampling and measurement under high pressure and high temperature conditions. The aerosol generation system is connected to the aerosol mixing system which injects SiO{sub 2}/ethanol mixture. In the sampling system, glass fiber membrane filter has been used to measure average mass concentration. Based on the experimental results using main carrier gas of steam and air mixture, the uncertainty estimation of the sampled aerosol concentration was performed by applying Gaussian error propagation law. FNC Technology Co., Ltd. has been developed the experimental facilities for the aerosol measurement under high pressure and high temperature. The purpose of the tests is to develop commercial test module for aerosol generation, mixing and sampling system applicable to environmental industry and safety related system in nuclear power plant. For the uncertainty calculation of aerosol concentration, the value of the sampled aerosol concentration is not measured directly, but must be calculated from other quantities. The uncertainty of the sampled aerosol concentration is a function of flow rates of air and steam, sampled mass, sampling time, condensed steam mass and its absolute errors. These variables propagate to the combination of variables in the function. Using operating parameters and its single errors from the aerosol test cases performed at FNC, the uncertainty of aerosol concentration evaluated by Gaussian error propagation law is less than 1%. The results of uncertainty estimation in the aerosol sampling system will be utilized for the system performance data.

  7. Relating soil solution Zn concentration to diffusive gradients in thin films measurements in contaminated soils.

    Science.gov (United States)

    Degryse, Fien; Smolders, Erik; Oliver, Ian; Zhang, Hao

    2003-09-01

    The technique of diffusive gradients in thin films (DGT) has been suggested to sample an available fraction of metals in soil. The objectives of this study were to compare DGT measurements with commonly measured fractions of Zn in soil, viz, the soil solution concentration and the total Zn concentration. The DGT technique was used to measure fluxes and interfacial concentrations of Zn in three series of field-contaminated soils collected in transects toward galvanized electricity pylons and in 15 soils amended with ZnCl2 at six rates. The ratio of DGT-measured concentration to pore water concentration of Zn, R, varied between 0.02 and 1.52 (mean 0.29). This ratio decreased with decreasing distribution coefficient, Kd, of Zn in the soil, which is in agreement with the predictions of the DGT-induced fluxes in soils (DIFS) model. The R values predicted with the DIFS model were generally larger than the observed values in the ZnCl2-amended soils at the higher Zn rates. A modification of the DIFS model indicated that saturation of the resin gel was approached in these soils, despite the short deployment times used (2 h). The saturation of the resin with Zn did not occur in the control soils (no Zn salt added) or the field-contaminated soils. Pore water concentration of Zn in these soils was predicted from the DGT-measured concentration and the total Zn content. Predicted values and observations were generally in good agreement. The pore water concentration was more than 5 times underpredicted for the most acid soil (pH = 3) and for six other soils, for which the underprediction was attributed to the presence of colloidal Zn in the soil solution.

  8. The effect of prolonged storage and disinfection on the dimensional stability of 5 vinyl polyether silicone impression materials.

    Science.gov (United States)

    Nassar, Usama; Flores-Mir, Carlos; Heo, Giseon; Torrealba, Ysidora

    2017-06-01

    Vinyl polyether silicone (VPES) has a different composition from other elastomeric impression materials as it combines vinyl polysiloxane (VPS) and polyether (PE). Therefore, it is important to study its properties and behavior under different test conditions. This study investigated the dimensional stability of 5 VPES consistencies when stored for up to 2 weeks, with and without using a standard disinfection procedure. 40 discs of each VPES consistency (total 200) were made using a stainless steel die and ring as described by ANSI /ADA specification No. 19. 20 discs of each material were immersed in a 2.5% buffered glutaraldehyde solution for 30 minutes. Dimensional stability measurements were calculated immediately after fabrication and repeated on the same discs after 7 and 14 days of storage. The data was analyzed using two-way ANOVA with a significance level set at α = 0.05. The discs mean contraction was below 0.5% at all test times ranging from 0.200 ± 0.014 to 0.325 ± 0.007. Repeated measures ANOVA showed a statistically significant difference after 2-week storage between the disinfected and non-disinfected groups ( P < .001). Although there was no statistically significant difference between the materials at the time of fabrication, the contraction of the materials increased with storage for 1 and 2 weeks. The dimensional changes of VPES impression discs after disinfection and prolonged storage complied with ANSI/ADA standard. The tested VPES impression materials were dimensionally stable for clinical use after disinfection for 30 minutes in glutaraldehyde and storage for up to 2 weeks.

  9. Method to make accurate concentration and isotopic measurements for small gas samples

    Science.gov (United States)

    Palmer, M. R.; Wahl, E.; Cunningham, K. L.

    2013-12-01

    Carbon isotopic ratio measurements of CO2 and CH4 provide valuable insight into carbon cycle processes. However, many of these studies, like soil gas, soil flux, and water head space experiments, provide very small gas sample volumes, too small for direct measurement by current constant-flow Cavity Ring-Down (CRDS) isotopic analyzers. Previously, we addressed this issue by developing a sample introduction module which enabled the isotopic ratio measurement of 40ml samples or smaller. However, the system, called the Small Sample Isotope Module (SSIM), does dilute the sample during the delivery with inert carrier gas which causes a ~5% reduction in concentration. The isotopic ratio measurements are not affected by this small dilution, but researchers are naturally interested accurate concentration measurements. We present the accuracy and precision of a new method of using this delivery module which we call 'double injection.' Two portions of the 40ml of the sample (20ml each) are introduced to the analyzer, the first injection of which flushes out the diluting gas and the second injection is measured. The accuracy of this new method is demonstrated by comparing the concentration and isotopic ratio measurements for a gas sampled directly and that same gas measured through the SSIM. The data show that the CO2 concentration measurements were the same within instrument precision. The isotopic ratio precision (1σ) of repeated measurements was 0.16 permil for CO2 and 1.15 permil for CH4 at ambient concentrations. This new method provides a significant enhancement in the information provided by small samples.

  10. Elastic Stability of Concentric Tube Robots: A Stability Measure and Design Test.

    Science.gov (United States)

    Gilbert, Hunter B; Hendrick, Richard J; Webster, Robert J

    2016-02-01

    Concentric tube robots are needle-sized manipulators which have been investigated for use in minimally invasive surgeries. It was noted early in the development of these devices that elastic energy storage can lead to rapid snapping motion for designs with moderate to high tube curvatures. Substantial progress has recently been made in the concentric tube robot community in designing snap-free robots, planning stable paths, and characterizing conditions that result in snapping for specific classes of concentric tube robots. However, a general measure for how stable a given robot configuration is has yet to be proposed. In this paper, we use bifurcation and elastic stability theory to provide such a measure, as well as to produce a test for determining whether a given design is snap-free (i.e. whether snapping can occur anywhere in the unloaded robot's workspace). These results are useful in designing, planning motions for, and controlling concentric tube robots with high curvatures.

  11. Evanescent Wave Absorption Based Fiber Sensor for Measuring Glucose Solution Concentration

    Science.gov (United States)

    Marzuki, Ahmad; Candra Pratiwi, Arni; Suryanti, Venty

    2018-03-01

    An optical fiber sensor based on evanescent wave absorption designed for measuring glucose solution consentration was proposed. The sensor was made to detect absorbance of various wavelength in the glucose solution. The sensing element was fabricated by side polishing of multimode polymer optical fiber to form a D-shape. The sensing element was immersed in different concentration of glucoce solution. As light propagated through the optical fiber, the evanescent wave interacted with the glucose solution. Light was absorbed by the glucose solution. The larger concentration the glucose solution has, the more the evanescent wave was absorbed in particular wavelenght. Here in this paper, light absorbtion as function of glucose concentration was measured as function of wavelength (the color of LED). We have shown that the proposed sensor can demonstrated an increase of light absorption as function of glucose concentration.

  12. Measurements of the size dependence of the concentration of nonvolatile material in fog droplets

    Science.gov (United States)

    Ogren, J. A.; Noone, K. J.; Hallberg, A.; Heintzenberg, J.; Schell, D.; Berner, A.; Solly, I.; Kruisz, C.; Reischl, G.; Arends, B. G.; Wobrock, W.

    1992-11-01

    Measurements of the size dependence of the mass concentration of nonvolatile material dissolved and suspended in fog droplets were obtained with three complementary approaches, covering a size range from c. 1 50µm diameter: a counterflow virtual impactor, an eight-stage aerosol impactor, and a two-stage fogwater impactor. Concentrations were observed to decrease with size over the entire range, contrary to expectations of increasing concentrations at larger sizes. It is possible that the larger droplets had solute concentrations that increased with increasing size, but that the increase was too weak for the measurements to resolve. Future studies should consider the hypothesis that the droplets were coated with a surface-active substance that hindered their uptake of water.

  13. The effect of the nuclear track detectors' position on the radon concentration measurements

    International Nuclear Information System (INIS)

    Yilmaz, A.; Kuerkcueoglu, M. E.; Haner, B.

    2009-01-01

    It is important to determine the radon concentration values of the underground mines according to workers' health. For this purpose, to be able to measure radon concentrations by using passive nuclear etched track detectors, CR-39 detectors were placed into 66 points on the way of aeration galleries of Armutcuk, Amasra, Karadon, Kozlu and Uezuelmez bituminous coal mines which are known as the Carboniferous outcrops of the Western Black Sea Area in Turkey. In every measurement point, a pair of detectors, one of them is being perpendicular and the other one is parallel to air flow, were exposed to radon gases over 40 days for four seasons of the year 2008. The relationship between the readings of vertically and horizontally positioned detectors was investigated by evaluating the effect of the detectors' positions on the detected radon concentrations. It can be concluded that, the vertically positioned detectors, in general, recorded higher radon gases concentration values than that of the horizontally positioned ones.

  14. Reactions on catalytic probe surface during oxygen plasma treatment of polyether sulphone: Reakcije na površini katalitične sonde med plazemsko obdelavo polieter sulfona:

    OpenAIRE

    Mozetič, Miran

    1998-01-01

    Experiments on the behavior of a nickel catalytic probe during activation of the surface of polyether sulphone in oxygen plasma are described. The temperature of the probe mounted 30 cm apart from inductively coupled RF oxygen plasma was measured for the case of empty dischaarge vessel and the case a sample with the dimensions of 8 cm x 1.2 cm x 0.4 cm was mounted in the middle of the discharge coil. It was found that both the maximum temperature and the first time derivative of the probe was...

  15. Measurement of radon progeny concentrations in air by alpha-particle spectrometey

    International Nuclear Information System (INIS)

    Kerr, G.D.

    1975-07-01

    A technique is presented for measuring air concentrations of the short-lived progeny of radon-222 by the use of alpha spectrometry. In this technique, the concentration of RaA, RaB, and RaC are calculated from one integral count of the RaA and two integral counts of the RaC' alpha-particle activity collected on a filter with an air sampling device. The influence of air sampling and counting intervals of time on the accuracy of the calculated concentrations is discussed in the report. A computer program is presented for use with this technique. It is written in the BASIC language. The program will calculate the air concentrations of RaA, RaB, and RaC, and will estimate the accuracy in these calculated concentrations. (U.S.)

  16. Comparison of Respirable Mass Concentrations Measured by a Personal Dust Monitor and a Personal DataRAM to Gravimetric Measurements.

    Science.gov (United States)

    Halterman, Andrew; Sousan, Sinan; Peters, Thomas M

    2017-12-15

    In 2016, the Mine Safety and Health Administration required the use of continuous monitors to measure respirable dust in mines and better protect miner health. The Personal Dust Monitor, PDM3700, has met stringent performance criteria for this purpose. In a laboratory study, respirable mass concentrations measured with the PDM3700 and a photometer (personal DataRam, pDR-1500) were compared to those measured gravimetrically for five aerosols of varying refractive index and density (diesel exhaust fume, welding fume, coal dust, Arizona road dust (ARD), and salt [NaCl] aerosol) at target concentrations of 0.38, 0.75, and 1.5 mg m-3. For all aerosols except coal dust, strong, near-one-to-one, linear relationships were observed between mass concentrations measured with the PDM3700 and gravimetrically (diesel fume, slope = 0.99, R2 = 0.99; ARD, slope = 0.98, R2 = 0.99; and NaCl, slope = 0.95, R2 = 0.99). The slope deviated substantially from unity for coal dust (slope = 0.55; R2 = 0.99). Linear relationships were also observed between mass concentrations measured with the pDR-1500 and gravimetrically, but one-to-one behavior was not exhibited (diesel fume, slope = 0.23, R2 = 0.76; coal dust, slope = 0.54, R2 = 0.99; ARD, slope = 0.61, R2 = 0.99; NaCl, slope = 1.14, R2 = 0.98). Unlike the pDR-1500, mass concentrations measured with the PDM3700 appear independent of refractive index and density, suggesting that it could have applications in a variety of occupational settings. © The Author(s) 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  17. Establishing traceability of photometric absorbance values for accurate measurements of the haemoglobin concentration in blood

    Science.gov (United States)

    Witt, K.; Wolf, H. U.; Heuck, C.; Kammel, M.; Kummrow, A.; Neukammer, J.

    2013-10-01

    Haemoglobin concentration in blood is one of the most frequently measured analytes in laboratory medicine. Reference and routine methods for the determination of the haemoglobin concentration in blood are based on the conversion of haeme, haemoglobin and haemiglobin species into uniform end products. The total haemoglobin concentration in blood is measured using the absorbance of the reaction products. Traceable absorbance measurement values on the highest metrological level are a prerequisite for the calibration and evaluation of procedures with respect to their suitability for routine measurements and their potential as reference measurement procedures. For this purpose, we describe a procedure to establish traceability of spectral absorbance measurements for the haemiglobincyanide (HiCN) method and for the alkaline haematin detergent (AHD) method. The latter is characterized by a higher stability of the reaction product. In addition, the toxic hazard of cyanide, which binds to the iron ion of the haem group and thus inhibits the oxygen transport, is avoided. Traceability is established at different wavelengths by applying total least-squares analysis to derive the conventional quantity values for the absorbance from the measured values. Extrapolation and interpolation are applied to get access to the spectral regions required to characterize the Q-absorption bands of the HiCN and AHD methods, respectively. For absorbance values between 0.3 and 1.8, the contributions of absorbance measurements to the total expanded uncertainties (95% level of confidence) of absorbance measurements range from 1% to 0.4%.

  18. PET measurement of FK506 concentration in a monkey model of stroke

    International Nuclear Information System (INIS)

    Murakami, Yoshihiro; Takamatsu, Hiroyuki; Noda, Akihiro; Osoda, Kazuhiko; Nishimura, Shintaro

    2007-01-01

    Introduction: The immunosuppressive agent FK506 (tacrolimus) has neuroprotective properties in an experimental model of cerebral ischemia. To improve the accuracy of clinical studies in acute stroke, a clinical dose setting should be based on the brain concentration, but not on the blood concentration of agents in humans. We have already established a measurement method using PET for FK506 concentration in the normal monkey brain, which could be applicable for human study; however, under ischemic conditions, in this study, we aimed to examine the brain concentration of FK506 in a monkey model of stroke. Methods: Studies were performed on six male cynomolgus monkeys (Macaca fascicularis) and a middle cerebral artery (MCA) occlusion model was used. Regional cerebral blood flow (rCBF) was measured by an intravenous injection of [ 15 O]H 2 O 165 min after MCA occlusion. FK506 (0.1 mg/kg) containing [ 11 C]FK506 was intravenously injected into the monkeys 180 min after MCA occlusion, and dynamic PET images were acquired for 30 min after administration. FK506 concentrations in the brain were calculated in moles per liter (M) units using the specific activity of injected FK506. Results: MCA occlusion produced ischemia, confirmed by rCBF measurement before the administration of [ 11 C]FK506. Fifteen minutes after FK506 (0.1 mg/kg) administration, the concentrations in the contralateral and ipsilateral cortex were 22.4±6.4 and 19.7±4.0 ng/g, respectively. Conclusion: We successfully measured the brain concentration of FK506 in a monkey model of stroke. The difference between the contralateral and ipsilateral concentrations of FK506 was not significant. This characteristic that FK506 readily penetrates ischemic tissue as well as normal tissue might explain the neuroprotective effect of FK506 in the ischemic brain and is suitable for the treatment of stroke patients

  19. Development of a 10 Hz measurement system for atmospheric aerosol concentration

    International Nuclear Information System (INIS)

    Bouarouri, Assia

    2014-01-01

    The goal is to develop an aerosol charger based on a corona discharge for atmospheric concentration measurements (10 3 -10 5 cm -3 ) within a response time of 100 ms. Two ion sources, point-to-hole and wire-to-slit have been characterized. The increase of the ion flow in the post-discharge by EHD ion confinement in both the discharge gap and the hole has been shown. At first, using an experimental survey driven in two mixing configurations, concentric and face-to-face, we have confirmed the aerosol diffusion charging law which depends on aerosol diameter and N i .t product, with N i , the ions concentration and t, the charging time. Thus, the originality of this charger relies on the very high heterogeneity of unipolar ion densities (N i 0 ≥10 9 cm -3 ) required to compensate the charging time of 50 ms. In these conditions, we have shown that aerosol diameter and the charging dynamic (which depends also on the diameter) control the aerosol trajectory. The chargers have, next, been compared in different operating conditions, mainly in terms of the maximal charging and the minimal losses. In the chosen charger (point-to-hole ion source and concentric mixing), the relations charge/mobility and losses according to diameter have been characterized. We have also shown the linearity of the charged particles current with the aerosol concentration which allows the current-concentration data inversion. The preliminary measurement system composed by the charger, the separator and the particle current measurements, satisfies the objectives of the study in terms of the concentration detection limit (10 3 cm -3 ) and the response time (100 ms). We have thus shown the feasibility of an atmospheric aerosol concentration measurement system at 10 Hz using a corona discharge charger provided that the separation power is improved. Furthermore, knowing that aerosol losses are negligible and the lower limit of the partial charging, the developed charger is adaptable with other

  20. Integrated Microanalytical System for Simultaneous Voltammetric Measurements of Free Metal Ion Concentrations in Natural Waters

    OpenAIRE

    Noël, Stéphane; Tercier-Waeber, Mary-Lou; Lin, Lin; Buffle, Jacques; Guenat, Olivier; Koudelka-Hep, Milena

    2007-01-01

    A complexing gel integrated microelectrode (CGIME) for direct measurements of free metal ion concentrations in natural waters has been developed. It is prepared by the successive deposition of microlayers of a chelating resin, an antifouling agarose gel and Hg on a 100-interconnected Ir-based microelectrode array. The trace metals of interest are in a first step accumulated on the chelating resin in proportion to their free ion concentration in solution, then released in acidic solution and d...

  1. The measurement of thoron (220Rn) concentration in indoor air continuously using pylon model WLx

    International Nuclear Information System (INIS)

    Hasnel Sofyan

    2011-01-01

    The concentration of thoron ( 220 Rn) in particular location can be higher than radon ( 220 Rn), however, its presence is always neglected. This might be due to the difficulties in calibration and discrimination between radon and thoron. From biokinetic and dosimetric model, it has been known that the dominant contribution of thoron to the effective dose is in the lungs. UNSCEAR estimates the doses contribution of thoron and its progenies is between 5-10% of the annual dose received by the general public and the risk level is 4.4 times greater than radon and progenies. Therefore, it is necessary to study the thoron concentration in indoor air and workplaces. Radon-thoron concentration in indoor air can be determined by direct methods using Pylon Model WLx device and passive methods using Solid State Nuclear Track Detector (SSNTDs). In this research the measurement of thoron was carried out continuously using Pylon Model WLx equipment that is sensitive to radon for 24, 65, 72, 116 and 154 hours in different rooms. The measurement result showed that the mean value of thoron working level (WL) concentration obtained in room-1 was 2.53 ± 0.67 Bq/m 3 with maximum and minimum of thoron concentrations were 3.37 and 2.22 Bq/m 3 respectively. From the measurement in different locations, it was obtained that the largest and smallest average concentrations of thoron progenies were 0.83 ± 0.23 Bq/m 3 and 0.29 ± 0.64 Bq/m 3 , while the maximum and minimum concentration values were 7.80 Bq/m 3 and 0.01 Bq/m 3 respectively. Pylon Model WLx device is not enables to be used for longer and large scale survey area concurrently, so the SSNTDs which is sensitive to the emission of alpha particles and can measure cumulative thoron concentrations is required. (author)

  2. Evaluating the reliability of uranium concentration and isotope ratio measurements via an interlaboratory comparison program

    International Nuclear Information System (INIS)

    Oliveira Junior, Olivio Pereira de; Oliveira, Inez Cristina de; Pereira, Marcia Regina; Tanabe, Eduardo

    2009-01-01

    The nuclear fuel cycle is a strategic area for the Brazilian development because it is associated with the generation of electricity needed to boost the country economy. Uranium is one the chemical elements in this cycle and its concentration and isotope composition must be accurately known. In this present work, the reliability of the uranium concentration and isotope ratio measurements carried out at the CTMSP analytical laboratories is evaluated by the results obtained in an international interlaboratory comparison program. (author)

  3. Direct concentration and viability measurement of yeast in corn mash using a novel imaging cytometry method.

    Science.gov (United States)

    Chan, Leo L; Lyettefi, Emily J; Pirani, Alnoor; Smith, Tim; Qiu, Jean; Lin, Bo

    2011-08-01

    Worldwide awareness of fossil-fuel depletion and global warming has been increasing over the last 30 years. Numerous countries, including the USA and Brazil, have introduced large-scale industrial fermentation facilities for bioethanol, biobutanol, or biodiesel production. Most of these biofuel facilities perform fermentation using standard baker's yeasts that ferment sugar present in corn mash, sugar cane, or other glucose media. In research and development in the biofuel industry, selection of yeast strains (for higher ethanol tolerance) and fermentation conditions (yeast concentration, temperature, pH, nutrients, etc.) can be studied to optimize fermentation performance. Yeast viability measurement is needed to identify higher ethanol-tolerant yeast strains, which may prolong the fermentation cycle and increase biofuel output. In addition, yeast concentration may be optimized to improve fermentation performance. Therefore, it is important to develop a simple method for concentration and viability measurement of fermenting yeast. In this work, we demonstrate an imaging cytometry method for concentration and viability measurements of yeast in corn mash directly from operating fermenters. It employs an automated cell counter, a dilution buffer, and staining solution from Nexcelom Bioscience to perform enumeration. The proposed method enables specific fluorescence detection of viable and nonviable yeasts, which can generate precise results for concentration and viability of yeast in corn mash. This method can provide an essential tool for research and development in the biofuel industry and may be incorporated into manufacturing to monitor yeast concentration and viability efficiently during the fermentation process.

  4. Concentrations of OH and HO2 radicals during NAMBLEX: measurements and steady state analysis

    Directory of Open Access Journals (Sweden)

    S. C. Smith

    2006-01-01

    Full Text Available OH and HO2 concentrations were measured simultaneously at the Mace Head Atmospheric Research Station in the summer of 2002 during the NAMBLEX (North Atlantic Marine Boundary Layer EXperiment field campaign. OH was measured by laser-induced fluorescence employing the FAGE (Fluorescence Assay by Gas Expansion technique, with a mean daytime detection limit of 2.7×105 molecule cm−3 (5 min acquisition period; signal-to-noise ratio = 1. HO2 was detected as OH following its chemical conversion through addition of NO, with a mean detection limit of 4.4×106 molecule cm−3. The diurnal variation of OH was measured on 24 days, and that of HO2 on 17 days. The local solar noon OH concentrations ranged between (3–8×106 molecule cm−3, with a 24 h mean concentration of 9.1×105 molecule cm−3. The local solar noon HO2 concentrations were (0.9–2.1×108 molecule cm−3 (3.5–8.2 pptv, with a 24 h mean concentration of 4.2×107 molecule cm−3 (1.6 pptv. HO2 radicals in the range (2–3×107 molecule cm−3 were observed at night. During NAMBLEX, a comprehensive suite of supporting measurements enabled a detailed study of the behaviour of HOx radicals under primarily clean marine conditions. Steady state expressions are used to calculate OH and HO2 concentrations and to evaluate the effect of different free-radical sources and sinks. The diurnally averaged calculated to measured OH ratio was 1.04±0.36, but the ratio displays a distinct diurnal variation, being less than 1 during the early morning and late afternoon/evening, and greater than 1 in the middle of the day. For HO2 there was an overprediction, with the agreement between calculated and measured concentrations improved by including reaction with measured IO and BrO radicals and uptake to aerosols. Increasing the concentration of IO radicals included in the calculations to above that measured by a DOAS instrument with an absorption path located mainly over the ocean, reflecting the

  5. Atmospheric alcohols and aldehydes concentrations measured in Osaka, Japan and in Sao Paulo, Brazil

    International Nuclear Information System (INIS)

    Nguyen, Ha Thi-Hoang; Takenaka, Norimichi; Bandow, Hiroshi; Maeda, Yasuaki; Oliva, S.T. de; Botelho, M.M.; Tavares, T.M.

    2001-01-01

    The use of alcohol fuel has received much attention since the 1980s. In Brazil, ethanol-fuelled vehicles have been currently used on a large scale. This paper reports the atmospheric methanol and isoproponal concentrations which were measured from May to December 1997, in Osaka, Japan, where alcohol fuel was not used and from 3 to 9 February 1998 in Sao Paulo, Brazil, where ethanol was used. The alcohols were determined by the alkyl nitrite formation reaction using gas chromatography (GC-ECD) analysis. The concentration of atmospheric alcohols, especially ethanol, measured in Sao Paulo were significantly higher than those in Osaka. In Osaka, the average concentrations of atmospheric methanol, ethanol, and isopropanol were 5.8 ± 3.8, 8.2 ± 4.6, and 7.2 ± 5.9ppbv, respectively. The average ambient levels of methanol, ethanol, and isopropanol measured in Sao Paulo were 34.1± 9.2, 176.3 ± 38.1, and 44.2 ± 13.7ppbv, respectively. The ambient levels of aldehydes, which were expected to be high due to the use of alcohol fuel, were also measured at these sampling sites. The atmospheric formaldehyde average measured in Osaka was 1.9± 0.9ppbv, and the average acetaldehyde concentration was 1.5 ± 0.8ppbv. The atmospheric formaldehyde and acetaldehyde average concentrations measured in Sao Paulo were 5.0 ± 2.8 and 5.4 ± 2.8ppbv, respectively. The C 2 H 5 OH/CH 3 OH and CH 3 CHO/HCHO were compared between the two measurement sites and elsewhere in the world, which have already been reported in the literature. Due to the use of ethanol-fuelled vehicles, these ratios, especially C-2H 5 OH/CH 3 OH, are much higher in Brazil than those measured elsewhere in the world. (Author)

  6. On-chip measurements of Brownian relaxation vs. concentration of 40nm magnetic beads

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Rizzi, Giovanni; Hansen, Mikkel Fougt

    2012-01-01

    We present on-chip Brownian relaxation measurements on a logarithmic dilution series of 40 nm beads dispersed in water with bead concentrations between 16 mu g/ml and 4000 mu g/ml. The measurements are performed using a planar Hall effect bridge sensor at frequencies up to 1 MHz. No external fields...... are needed as the beads are magnetized by the field generated by the applied sensor bias current. We show that the Brownian relaxation frequency can be extracted from fitting the Cole-Cole model to measurements for bead concentrations of 64 mu g/ml or higher and that the measured dynamic magnetic response...... is proportional to the bead concentration. For bead concentrations higher than or equal to 500 mu g/ml, we extract a hydrodynamic diameter of 47(1) nm for the beads, which is close to the nominal bead size of 40 nm. Furthermore, we study the signal vs. bead concentration at a fixed frequency close to the Brownian...

  7. On the deduction of chemical reaction pathways from measurements of time series of concentrations.

    Science.gov (United States)

    Samoilov, Michael; Arkin, Adam; Ross, John

    2001-03-01

    We discuss the deduction of reaction pathways in complex chemical systems from measurements of time series of chemical concentrations of reacting species. First we review a technique called correlation metric construction (CMC) and show the construction of a reaction pathway from measurements on a part of glycolysis. Then we present two new improved methods for the analysis of time series of concentrations, entropy metric construction (EMC), and entropy reduction method (ERM), and illustrate (EMC) with calculations on a model reaction system. (c) 2001 American Institute of Physics.

  8. Experimental Determination of Drug Diffusion Coefficients in Unstirred Aqueous Environments by Temporally Resolved Concentration Measurements

    DEFF Research Database (Denmark)

    Di Cagno, Massimiliano Pio; Clarelli, Fabrizio; Vabenø, Jon

    2018-01-01

    or the need for dedicated instrumentation. In this work, a simple but reliable method based on time resolved concentration measurements by UV-visible spectroscopy in an unstirred aqueous environment was developed. This method is based on spectroscopic measurement of the variation of the local concentration...... characteristics (i.e. ionic strength and presence of complexing agents) on the diffusivity. The method can be employed in any research laboratory equipped with a standard UV-visible spectrophotometer, and could become a useful and straightforward tool in order to characterize diffusion coefficients...

  9. Measurement of thyroid volume, iodine concentration and total iodine content by CT and its clinical significance

    International Nuclear Information System (INIS)

    Nakaji, Shunsuke; Imanishi, Yoshimasa; Okamoto, Kyouko; Shinagawa, Toshihito

    2007-01-01

    Recently, Imanishi et al have developed new CT software for quantitative in vivo measurement of thyroid iodine. Using a CT system with the software, we measured volume, iodine concentration and total iodine content of thyroids in 63 controls and 435 patients with various diffuse thyroid diseases and thyroid nodules. In controls, all of them showed no difference between the sexes. Although the iodine concentration of the thyroid showed no difference among children, adults and seniles, the volume and total iodine content of the thyroid appeared smaller in children and seniles than in adults. In addition, although the volume and iodine concentration of the thyroid had two peaks in distribution, the total iodine content had almost normal distribution. Normal range of volume, iodine concentration and total iodine content in adults were 5.2-15.5 cm 3 , 0.28831-0.85919 mg/cm 3 and 2.35-11.69 mg, respectively. In thyroid nodule, there is no significant difference in volume, iodine concentration and total iodine content between benign and malignant nodules. All nodules with iodine concentration of less than 0.00007 mg/cm 3 were benign. No thyroid was higher in iodine concentration than the normal range although the thyroid was lower in 78.7% of patients with diffuse thyroid diseases. In all thyroids with increasing iodine concentration and total iodine content in medication course, thyroidal symptoms and signs were uncontrollable by the medication. In 43.8% of patients with long-period systemic diseases, the thyroid showed abnormality in any of the three. We concluded that quantitative in vivo measurement of thyroid iodine by CT could assist the diagnosis of thyroid diseases and decision of therapeutic methods. (author)

  10. Windows pollution problems of the dust concentration measurement based on scattering method

    International Nuclear Information System (INIS)

    Zhao Yanjun; Zhang Yongtao; Shi Xinyue; Xu Chuanlong; Wang Shimin

    2009-01-01

    The windows are separated the measurement system from the dust space in the light Scattering dust concentration measurement system. The windows are polluted unavoidably by the dust and the measurement error is produced. Based on the Mie Scattering theory, the measurement error is researched in this paper. The numerical simulation results show that the measurement error is related to the particles diameter distribution and the refractive index, but is independent of the particles average diameter. A novel photoelectricity sensor is developed in this paper in order to solve the measurement error by the windows pollution. The calculated method is brought out which can amend the measurement errors by the windows pollution and improve the measurement accuracy.

  11. Polyether ether ketone encased monolith frits made of polyether ether ketone tubing with a 0.25 mm opening resulting in an improved separation performance in liquid chromatography.

    Science.gov (United States)

    Park, Sin Young; Cheong, Won Jo

    2016-05-01

    Tiny polyether ether ketone encased monolith frits have been prepared by modified catalytic sulfonation of the inner surface of polyether ether tubing (1.6 mm od, 0.25 mm id) followed by modified formation of organic monolith and cutting of the tubing into slices. The frit was placed below the central hole of the column outlet union and supported by a combination of a silica capillary (0.365 mm od, 0.05 mm id) and a polyether ether ketone sleeve (1.6 mm od, 0.38 mm id) tightened with a nut and a ferrule when the column was packed to prevent sinking of the frit element into the union hole (0.25 mm opening) otherwise. The column packed this way with the frits investigated in this study has shown better separation performance owing to the reduced frit volume in comparison to the column packed with a commercial stainless-steel screen frit. This study establishes the strategy of disposable microcolumns in which cheap disposable frits are used whenever the column is re-packed to yield columns of even better chromatographic performance than the columns with commercial frits. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Bio-functionalisation of polyether ether ketone using plasma immersion ion implantation

    Science.gov (United States)

    Wakelin, Edgar; Yeo, Giselle; Kondyurin, Alexey; Davies, Michael; McKenzie, David; Weiss, Anthony; Bilek, Marcela

    2015-12-01

    Plasma immersion ion implantation (PIII) is used here to improve the surface bioactivity of polyether ether ketone (PEEK) by modifying the chemical and mechanical properties and by introducing radicals. Modifications to the chemical and mechanical properties are characterised as a function of ion fluence (proportional to treatment time) to determine the suitability of the treated surfaces for biological applications. Radical generation increases with treatment time, where treatments greater than 400 seconds result in a high concentration of long-lived radicals. Radical reactions are responsible for oxidation of the surface, resulting in a permanent increase in the polar surface energy. The nano-scale reduced modulus was found to increase with treatment time at the surface from 4.4 to 5.2 GPa. The macromolecular Young's modulus was also found to increase, but by an amount corresponding to the volume fraction of the ion implanted region. The treated surface layer exhibited cracking under cyclical loads, associated with an increased modulus due to dehydrogenation and crosslinking, however it did not show any sign of delamination, indicating that the modified layer is well integrated with the substrate - a critical factor for bioactive surface coatings to be used in-vivo. Protein immobilisation on the PIII treated surfaces was found to saturate after 240 seconds of treatment, indicating that there is room to tune surface mechanical properties for specific applications without affecting the protein coverage. Our findings indicate that the modification of the chemical and mechanical properties by PIII treatments as well as the introduction of radicals render PEEK well suited for use in orthopaedic implantable devices.

  13. Ambient concentrations of aldehydes in relation to Beijing Olympic air pollution control measures

    Science.gov (United States)

    Gong, J. C.; Zhu, T.; Hu, M.; Zhang, L. W.; Cheng, H.; Zhang, L.; Tong, J.; Zhang, J.

    2010-08-01

    Aldehydes are ubiquitous constituents of the atmosphere. Their concentrations are elevated in polluted urban atmospheres. The present study was carried out to characterize three aldehydes of most health concern (formaldehyde, acetaldehyde, and acrolein) in a central Beijing site in the summer and early fall of 2008 (from June to October). Measurements were made before, during, and after the Beijing Olympics to examine whether the air pollution control measures implemented to improve Beijing's air quality during the Olympics had any impact on concentrations of the three aldehydes. Average concentrations of formaldehyde, acetaldehyde and acrolein were 29.34 ± 15.12 μg/m3, 27.09 ± 15.74 μg/m3 and 2.32 ± 0.95 μg/m3, respectively, for the entire period of measurements, all being the highest among the levels measured in cities around the world in photochemical smog seasons. Among the three measured aldehydes, only acetaldehyde had a substantially reduced mean concentration during the Olympic air pollution control period compared to the pre-Olympic period. Formaldehyde and acrolein followed the changing pattern of temperature and were each significantly correlated with ozone (a secondary product of photochemical reactions). In contrast, acetaldehyde was significantly correlated with several pollutants emitted mainly from local emission sources (e.g., NO2, CO, and PM2.5). These findings suggest that local direct emissions had a larger impact on acetaldehyde than formaldehyde and acrolein.

  14. Feasibility of Uranium Concentration Measurements for H Canyon Tank 16.7

    International Nuclear Information System (INIS)

    Lascola, R.J.

    2003-01-01

    Savannah River Technology Center (SRTC) evaluated the feasibility of using the H Canyon on-line diode array spectrophotometer to measure uranium concentrations in Tank 16.7. On-line measurements will allow an increase in highly enriched uranium (HEU) production by removing delays associated with off-line measurements. The instrument must be able to measure uranium at concentrations below 1.0 g/L with an uncertainty no greater than 0.3 g/L. SRTC determined that the system has a limit of quantitation of 0.15 g/L. At concentrations of 0.5 and 1.0 g/L, the spectrometer uncertainty is 0.10 g/L. No design changes, such as an increase in flow cell path length, are required to obtain this performance. Expected levels of iron in Tank 16.7 solutions will not interfere with the measurement. The CHEMCHEK method should not be used for confirmatory analysis, as it contributes excessively to the overall uncertainty of the measurement. SRTC expects that the spectrophotometer will meet the measurement requirements for Tank 16.7

  15. On the Usage of Cyclic Voltammetry and Impedance Spectroscopy for Measuring the Concentration of Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Manuel Fiedler

    2015-02-01

    Full Text Available This article describes sensors for concentration measurement based on the electro- chemical properties of the liquid being measured. Herein two electrical methods, namely cyclic voltammetry and impedance spectroscopy, are being presented. The measurement can be performed quasi simultaneously using the same measurement medium. Further optimization of the combined methods is possible by adapting the geometric design of the electrode structure, the electrode material, the optional passivation and the electric coupling (galvanically or capacitively. In summary, by combining multiple sensory principles on a device it becomes possible to analyze mixtures of substances contained in a solution with respect to their composition.

  16. The design and realization of calibration apparatus for measuring the concentration of radon in three models

    Energy Technology Data Exchange (ETDEWEB)

    Huiping, Guo [The Second Artillery Engineering College, Xi' an (China)

    2007-06-15

    For satisfying calibration request of radon measure in the laboratory, the calibration apparatus for radon activity measure is designed and realized. The calibration apparatus can auto-control and auto-measure in three models. sequent mode, pulse mode and constant mode. The stability and reliability of the calibration apparatus was tested under the three models. The experimental result shows that the apparatus can provides an adjustable and steady radon activity concentration environment for the research of radon and its progeny and for the calibration of its measure. (authors)

  17. Measurement of indoor radon Concentrations in Osaka, Nara, Wakayama and Hyogo with passive dosemeters

    International Nuclear Information System (INIS)

    Mori, Toshiaki; Hori, Yasuharu; Takeda, Atsuhiko; Iwasaki, Tamiko; Uchiyama, Masahumi; Fujimoto, Kenzo; Kankura, Takako; Kobayashi, Sadayosi.

    1989-01-01

    Indoor radon concentrations of 792 houses in Osaka, Nara, Wakayama and Hyogo were measured by the passive dosemeter which was developed in Karlsruhe Nuclear Research Center in West Germany. Each house was measured at two places for successive two periods of six months to obtain annual average exposure due to radon daughters. The arithmetic mean concentration of all houses was 45.2 Bq/m 3 with a standard deviation of 27.2; the geometric mean, 40.7 Bq/m 3 and the median, 39 Bq/m 3 . The distribution of the radon levels was approximately log-normal with 80% of houses having radon concentrations less than 60 Bq/m 3 . The seasonal variation of the mean radon concentration was evident between the former period including winter value of 45 Bq/m 3 and the latter including summer value of 32 Bq/m 3 . The indoor radon concentrations of wooden houses were found to have the widest distribution with the highest value of 371 Bq/m 3 . The highest value obtained in the ferro-concrete house was 118 Bq/m 3 . Twelve houses having indoor radon concentrations higher than 120 Bq/m 3 were all Japanese traditional wooden houses with walls made of soil. (author)

  18. Full-field dye concentration measurement within saturated/unsaturated thin slabs of porous media

    International Nuclear Information System (INIS)

    Norton, D.L.; Glass, R.J.

    1993-01-01

    This paper presents a full-field dye concentration measurement technique that extends our experimental capabilities to the measurement of transient dye concentration fields within steady state flow fields under unsaturated or saturated conditions. Simple light absorption theory provides a basis for translating images into high resolution dye concentration fields. A series of dye pulse experiments that demonstrate the combined use of the full-field saturation and dye concentration techniques was conducted at four different degrees of saturation. Each of these experimental sequences was evaluated with respect to mass balance, the results being within 5% of the known dye mass input. An image windowing technique allowed us to see increased dispersion due to decreasing moisture content, tailing of concentration at the rear of the dye pulse and slight velocity changes of the dispersive front due to changes in moisture content. The exceptional resolution of dye concentration in space and time provided by this laboratory technique allows systematic experimentation for examining basic processes affecting solute transport within saturated/unsaturated porous media. Future challenges for this work will be to use these techniques to analyze more complex systems involving heterogeneities, scaling laws, and detailed investigations of the relationship between transverse and longitudinal dispersion in unsaturated media

  19. Saliva oxytocin measures do not reflect peripheral plasma concentrations after intranasal oxytocin administration in men.

    Science.gov (United States)

    Quintana, Daniel S; Westlye, Lars T; Smerud, Knut T; Mahmoud, Ramy A; Andreassen, Ole A; Djupesland, Per G

    2018-05-16

    Oxytocin plays an important role in social behavior. Thus, there has been significant research interest for the role of the oxytocin system in several psychiatric disorders, and the potential of intranasal oxytocin administration to treat social dysfunction. Measurement of oxytocin concentrations in saliva are sometimes used to approximate peripheral levels of oxytocin; however, the validity of this approach is unclear. In this study, saliva and plasma oxytocin was assessed after two doses of Exhalation Delivery System delivered intranasal oxytocin (8 IU and 24 IU), intravenous oxytocin (1 IU) and placebo in a double-dummy, within-subjects design with men. We found that intranasal oxytocin (8 IU and 24 IU) administration increased saliva oxytocin concentrations in comparison to saliva oxytocin concentration levels after intravenous and placebo administration. Additionally, we found that saliva oxytocin concentrations were not significantly associated with plasma oxytocin concentrations after either intranasal or intravenous oxytocin administration. Altogether, we suggest that saliva oxytocin concentrations do not accurately index peripheral oxytocin after intranasal or intravenous oxytocin administration, at least in men. The data indicates that elevated oxytocin saliva levels after nasal delivery primarily reflect exogenous administered oxytocin that is cleared from the nasal cavity to the oropharynx, and is therefore a weak surrogate for peripheral blood measurements. Copyright © 2018 Elsevier Inc. All rights reserved.

  20. Comparison of VIDAS and Radioimmunoassay Methods for Measurement of Cortisol Concentration in Bovine Serum

    Directory of Open Access Journals (Sweden)

    Daniela Proverbio

    2013-01-01

    Full Text Available Radioimmunoassay (RIA is the “gold standard” method for evaluation of serum cortisol concentration. The VIDAS cortisol test is an enzyme-linked fluorescent assay designed for the MiniVidas system. The aim of this study was to compare the VIDAS method with RIA for measurement of bovine serum cortisol concentration. Cortisol concentrations were evaluated in 40 cows using both VIDAS and RIA methods, the latter as the reference method. A paired Student’s -test, Pearson’s correlation analysis, Bland-Altman plot, and Deming regression analysis were used to compare the two methods. There was no statistically significant difference between mean serum cortisol concentrations measured by VIDAS or RIA methods (. Both methods were able to detect significant differences in mean low and high cortisol concentrations ( RIA and VIDAS. The correlation coefficient was low, but a Bland-Altman plot and Deming regression analysis show neither constant nor proportional error. The VIDAS method produced slightly higher values than RIA, but the difference was small and in no case did the mean value move the normal range. Results suggest that VIDAS method is suitable for the determination of bovine serum cortisol concentration in studies of large numbers of animals.

  1. Serum cystatin C concentration measured routinely is a prognostic marker for renal disease in dogs.

    Science.gov (United States)

    Iwasa, Naoki; Takashima, Satoshi; Iwasa, Tatsuo; Iwasa, Kazuko; Suzuki, Tomomi; Kobatake, Yui; Kitagawa, Hitoshi; Nishii, Naohito

    2018-06-14

    This study examined the predictive value of serum cystatin C (Cys-C) concentration, measured during routine periodic health examinations, in the renal prognosis of dogs. A cohort of 140 dogs weighing C concentrations were measured during periodic health examinations from December 2013 to March 2016 were prospectively studied, with renal disease-related death the predicted end point. Of the 140 dogs, nine died from renal diseases during the follow-up period (539 ± 249 days). Serum Cys-C concentrations were higher in the dogs that subsequently died of renal disease than in the censored group (0.8 ± 0.25 vs. 0.3 ± 0.1 mg/dl, respectively; P C concentrations (>0.55 mg/dl) had a shorter (P C concentrations (≤0.55 mg/dl). In conclusion, high serum Cys-C concentrations in periodic health examinations in dogs <15 kg predicted poorer prognosis for renal function. Copyright © 2018. Published by Elsevier Ltd.

  2. Effects of poly-ether B on proteome and phosphoproteome expression in biofouling Balanus amphitrite cyprids

    KAUST Repository

    Dash, Swagatika; Chandramouli, Kondethimmanahalli; Zhang, Yu; Qian, Pei Yuan

    2012-01-01

    in recent years, although the mechanism by which they inhibit fouling is yet to be investigated. Poly-ether B has shown promise in the non-toxic inhibition of larval barnacle attachment. Hence, in this study, multiplex two-dimensional electrophoresis (2-DE

  3. Martinomycin, a new polyether antibiotic produced by Streptomyces salvialis. I. Taxonomy, fermentation and biological activity.

    Science.gov (United States)

    Bernan, V S; Montenegro, D A; Goodman, J J; Alluri, M R; Carter, G T; Abbanat, D R; Pearce, C J; Maiese, W M; Greenstein, M

    1994-12-01

    Actinomycete culture LL-D37187 has been found to produce the new polyether antibiotic martinomycin. Taxonomic studies, including morphological, physiological, and cell wall chemistry analyses, revealed that culture LL-D37187 is a novel streptomycete species, and the proposed name is Streptomyces salvialis. Martinomycin exhibits activity against the Southern Army Worm (Spodoptera eridania) and Gram-positive bacteria.

  4. Effects of poly-ether B on proteome and phosphoproteome expression in biofouling Balanus amphitrite cyprids

    KAUST Repository

    Dash, Swagatika

    2012-04-01

    Biofouling is ubiquitous in marine environments, and the barnacle Balanus amphitrite is one of the most recalcitrant and aggressive biofoulers in tropical waters. Several natural antifoulants that were claimed to be non-toxic have been isolated in recent years, although the mechanism by which they inhibit fouling is yet to be investigated. Poly-ether B has shown promise in the non-toxic inhibition of larval barnacle attachment. Hence, in this study, multiplex two-dimensional electrophoresis (2-DE) was applied in conjunction with mass spectrometry to investigate the effects of poly-ether B on barnacle larvae at the molecular level. The cyprid proteome response to poly-ether B treatment was analyzed at the total proteome and phosphoproteome levels, with 65 protein and 19 phosphoprotein spots found to be up- or down-regulated. The proteins were found to be related to energy-metabolism, oxidative stress, and molecular chaperones, thus indicating that poly-ether B may interfere with the redox-regulatory mechanisms governing the settlement of barnacle larvae. The results of this study demonstrate the usefulness of the proteomic technique in revealing the working mechanisms of antifouling compounds. © 2012 Copyright Taylor and Francis Group, LLC.

  5. A polyether glycol derived from cashew nutshell as a kinetic inhibitor for methane hydrate formation

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Jorge Cesar; Esteves, Pierre M., E-mail: pesteves@iq.ufrj.br [Instituto de Quimica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Teixeira, Adriana [Centro de Pesquisa e Desenvolvimento Leopoldo Americo Miguez de Mello, PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2012-07-01

    The polyether glycol derived from cashew nutshell liquid inhibited the formation of methane hydrate. The polymer proved to be more efficient than the polyvinyl pyrrolidone-poly(N-vinyl) caprolactam (PVP-PVCap) co-polymer under tested conditions (CH{sub 4}, 1470 psi and 4 degree C), being the latter one of the best commercially available hydrate inhibitors. (author)

  6. Biodegradation of polyether algal toxins–Isolation of potential marine bacteria

    Science.gov (United States)

    SHETTY, KATEEL G.; HUNTZICKER, JACQUELINE V.; REIN, KATHLEEN S.; JAYACHANDRAN, KRISH

    2012-01-01

    Marine algal toxins such as brevetoxins, okadaic acid, yessotoxin, and ciguatoxin are polyether compounds. The fate of polyether toxins in the aqueous phase, particularly bacterial biotransformation of the toxins, is poorly understood. An inexpensive and easily available polyether structural analog salinomycin was used for enrichment and isolation of potential polyether toxin degrading aquatic marine bacteria from Florida bay area, and from red tide endemic sites in the South Florida Gulf coast. Bacterial growth on salinomycin was observed in most of the enrichment cultures from both regions with colony forming units ranging from 0 to 6 × 107 per mL. The salinomycin biodegradation efficiency of bacterial isolates determined using LC-MS ranged from 22% to 94%. Selected bacterial isolates were grown in media with brevetoxin as the sole carbon source to screen for brevetoxin biodegradation capability using ELISA. Out of the two efficient salinomycin biodegrading isolates MB-2 and MB-4, maximum brevetoxin biodegradation efficiency of 45% was observed with MB-4, while MB-2 was unable to biodegrade brevetoxin. Based on 16S rRNA sequence similarity MB-4 was found have a match with Chromohalobacter sp. PMID:20954040

  7. SEC-MALDI-TOF mass spectral characterization of a hyperbranched polyether prepared via melt transetherification

    NARCIS (Netherlands)

    Jayakannan, M.; Dongen, van J.L.J.; Behera, G.Ch.; Ramakrishnan, S.

    2002-01-01

    An AB2 monomer, 1-(2-hydroxyethoxy)-3,5-bis-(methoxymethyl)-2,4,6-trimethylbenzene, was synthesized from mesitol and melt-polycondensed in the presence of an acid catalyst via a transetherification process at 145-150 °C to yield a soluble, moderately high molecular weight hyperbranched polyether.

  8. Biodegradation of polyether algal toxins--isolation of potential marine bacteria.

    Science.gov (United States)

    Shetty, Kateel G; Huntzicker, Jacqueline V; Rein, Kathleen S; Jayachandran, Krish

    2010-12-01

    Marine algal toxins such as brevetoxins, okadaic acid, yessotoxin, and ciguatoxin are polyether compounds. The fate of polyether toxins in the aqueous phase, particularly bacterial biotransformation of the toxins, is poorly understood. An inexpensive and easily available polyether structural analog salinomycin was used for enrichment and isolation of potential polyether toxin degrading aquatic marine bacteria from Florida bay area, and from red tide endemic sites in the South Florida Gulf coast. Bacterial growth on salinomycin was observed in most of the enrichment cultures from both regions with colony forming units ranging from 0 to 6×10(7) per mL. The salinomycin biodegradation efficiency of bacterial isolates determined using LC-MS ranged from 22% to 94%. Selected bacterial isolates were grown in media with brevetoxin as the sole carbon source to screen for brevetoxin biodegradation capability using ELISA. Out of the two efficient salinomycin biodegrading isolates MB-2 and MB-4, maximum brevetoxin biodegradation efficiency of 45% was observed with MB-4, while MB-2 was unable to biodegrade brevetoxin. Based on 16S rRNA sequence similarity MB-4 was found have a match with Chromohalobacter sp.

  9. Novel crosslinked membranes based on sulfonated poly(ether ether ketone) for direct methanol fuel cells.

    Science.gov (United States)

    Zhu, Yuanqin; Zieren, Shelley; Manthiram, Arumugam

    2011-07-14

    Novel covalently crosslinked membranes based on sulfonated poly(ether ether ketone) and carboxylated polysulfone exhibit much lower methanol crossover and better performance in direct methanol fuel cells at 65 °C in 1 and 2 M methanol solutions compared to Nafion 115 membranes.

  10. SEPARATION OF OCTYLPHENOL POLYETHER ALCOHOLS SURFACTANTS BY CAPILLARY COLUMN SFC AND HPLC

    Science.gov (United States)

    Separation of nonionic octylphenol polyether alcohols (OPA) by supercritical fluid chromatography (SFC) and HPLC is described. Using a density programming and a 50-μm i.d. capillary column, a total of 18 group oligomers was separated. The effects of the operating parameters, such...

  11. Thermal stability of sulfonated Poly(Ether Ether Ketone) films : on the role of Protodesulfonation

    NARCIS (Netherlands)

    Koziara, B.T.; Kappert, E.J.; Ogieglo, W.; Nijmeijer, Kitty; Hempenius, M.A.; Benes, N.E.

    Thin film and bulk, sulfonated poly(ether ether ketone) (SPEEK) have been subjected to a thermal treatment at 160–250 °C for up to 15 h. Exposing the films to 160 °C already causes partial desulfonation, and heating to temperatures exceeding 200 °C results in increased conjugation in the material,

  12. Partially fluorinated arylene polyethers and their ternary blend membranes with PBI and H3PO4

    DEFF Research Database (Denmark)

    Kerres, J.; Schonberger, F.; Chromik, A

    2008-01-01

    A partially fluorinated polyether ionomer from polycondensation of decafluorobiphenyl with 2,2-bis(4-hydroxyphenyl)-hexafluoropropane, followed by sulphonation with H2SO4 (60% SO3), has been prepared and optimised in terms of molecular weight and sulphonation degree. The partially fluorinated ion...

  13. Measurement of Rn-222 concentration in underground water in Osaka stratum group in Sennan area

    International Nuclear Information System (INIS)

    Fukui, Masami; Katsurayama, Kosuke

    1977-01-01

    The Rn-222 concentration in underground water is reported as follows, which is the result obtained when the ground inspection was carried out in the Research Reactor Institute of Kyoto University located at Kumatori area in Osaka stratum group. Underground water, at different depth, well water and rain water were taken, and the contained Rn-222 was extracted with toluene to measure by liquid scintillation technique. Rn-222 concentration in rain water was 3.5 - 8.0 pCi/l, while the concentration in well water was 130 - 250 pCi/l, and that in underground water was 240 - 313 pCi/l. The seasonal change, geographical difference and variation according to depth of Rn-222 concentration were examined. Rn-222 behavior in soil should be investigated more in detail in reference to Rn-222 dispersion, transport and equilibrium problems in soil-water system in the future. (Kobatake, H.)

  14. GUM approach to uncertainty estimations for online 220Rn concentration measurements using Lucas scintillation cell

    International Nuclear Information System (INIS)

    Sathyabama, N.

    2014-01-01

    It is now widely recognized that, when all of the known or suspected components of errors have been evaluated and corrected, there still remains an uncertainty, that is, a doubt about how well the result of the measurement represents the value of the quantity being measured. Evaluation of measurement data - Guide to the expression of Uncertainty in Measurement (GUM) is a guidance document, the purpose of which is to promote full information on how uncertainty statements are arrived at and to provide a basis for the international comparison of measurement results. In this paper, uncertainty estimations following GUM guidelines have been made for the measured values of online thoron concentrations using Lucas scintillation cell to prove that the correction for disequilibrium between 220 Rn and 216 Po is significant in online 220 Rn measurements

  15. Data on final calcium concentration in native gel reagents determined accurately through inductively coupled plasma measurements

    Directory of Open Access Journals (Sweden)

    Jeffrey Viviano

    2016-03-01

    Full Text Available In this article we present data on the concentration of calcium as determined by Inductively Coupled Plasma (ICP measurements. Calcium was estimated in the reagents used for native gel electrophoresis of Neuronal Calcium Sensor (NCS proteins. NCS proteins exhibit calcium-dependent mobility shift in native gels. The sensitivity of this shift to calcium necessitated a precise determination of calcium concentrations in all reagents used. We determined the calcium concentrations in different components used along with the samples in the native gel experiments. These were: 20 mM Tris pH 7.5, loading dye and running buffer, with distilled water as reference. Calcium determinations were through ICP measurements. It was found that the running buffer contained calcium (244 nM over the blank. Keywords: Neuronal calcium sensor proteins, Electrophoresis, Mobility shift, Calcium, Magnesium

  16. Heat transfer analysis in a calorimeter for concentrated solar radiation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Estrada, C.A.; Jaramillo, O.A.; Arancibia-Bulnes, C.A. [Universidad Nacional Autonoma de Mexico, Centro de Investigacion en Energia, Privada Xochicalco S/N, Col. Centro. Temixco, Morelos 62580 (Mexico); Acosta, R. [Universidad de Quintana Roo, Boulevard Bahia s/n Esq. I. Comonfort, Chetumal Quintana Roo 77019 (Mexico)

    2007-10-15

    A calorimeter was built for measuring the concentrated solar power produced by a point focus solar concentrator that was developed at CIE - UNAM. In order to obtain a thermal characterization of the calorimeter a theoretical and experimental heat transfer study is carried out. This study addresses the heat transfer in the circular flat plate of the calorimeter, which acts as receiver for the concentrating system. Temperatures are measured at different points of this plate and fit with a theoretical model that considers heat conduction with convective and radiative boundary conditions. In particular, it is possible to calculate the temperature distribution on the irradiated surface. This allows to examine the validity of the assumptions of cold water calorimetry, which was the technique applied to this system in previous works. (author)

  17. Measurement of gross alpha and gross beta activity concentrations in human tooth

    International Nuclear Information System (INIS)

    Soeguet, Omer; Aydin, Mehmet Fatih; Kuecuekoender, Erdal; Zorer, Ozlem Selcuk; Dogru, Mahmut

    2010-01-01

    The gross alpha and gross beta activity concentrations were measured in human tooth taken from 3 to 6 age-groups to 40 and over ones. Accumulated teeth samples are investigated in two groups as under and above 18 years. The gross alpha and beta radioactivity of human tooth samples was measured by using a gas-flow proportional counter (PIC-MPC 9604-α/β counter). In tooth samples, for female age-groups, the obtained results show that the mean gross alpha and gross beta activity concentrations varied between 0.534-0.203 and 0.010-0.453 Bq g -1 and the same concentrations for male age-groups varied between 0.009-1.168 and 0.071-0.204 Bq g -1 , respectively.

  18. Measurement of radon exhalation rate and soil gas radon concentration in areas of southern Punjab (Pakistan)

    International Nuclear Information System (INIS)

    Mujahid, S. A.; Hussain, S.; Ramzan, M.

    2010-01-01

    Plastic track detectors were used to measure the radon concentration and exhalation rate from the soil samples. The samples were collected from areas of southern Punjab (Pakistan). In a laboratory experiment, passive alpha dosemeters were installed inside cylindrical bottles containing the soil samples. The radon concentrations and the radon exhalation rate were found in the ranges of 34±7 to 260±42 Bq m -3 and 38±8 to 288±46 mBq m -2 h -1 , respectively. The on-site measurements of radon in the soil gas were also carried out in these areas using a scintillation alpha counter. The concentration of radon in the soil gas was found in the range of 423±82-3565±438 Bq m -3 . (authors)

  19. Noninvasive measurement of glucose concentration on human fingertip by optical coherence tomography

    Science.gov (United States)

    Chen, Tseng-Lin; Lo, Yu-Lung; Liao, Chia-Chi; Phan, Quoc-Hung

    2018-04-01

    A method is proposed for determining the glucose concentration on the human fingertip by extracting two optical parameters, namely the optical rotation angle and the depolarization index, using a Mueller optical coherence tomography technique and a genetic algorithm. The feasibility of the proposed method is demonstrated by measuring the optical rotation angle and depolarization index of aqueous glucose solutions with low and high scattering, respectively. It is shown that for both solutions, the optical rotation angle and depolarization index vary approximately linearly with the glucose concentration. As a result, the ability of the proposed method to obtain the glucose concentration by means of just two optical parameters is confirmed. The practical applicability of the proposed technique is demonstrated by measuring the optical rotation angle and depolarization index on the human fingertip of healthy volunteers under various glucose conditions.

  20. Measurement of the terrestrial and anthropogenic radionuclide concentrations in Bafra Kizilirmak delta (bird sanctuary) in Turkey

    International Nuclear Information System (INIS)

    Mutuk, H.; Guemues, H.; Turhan, S.

    2014-01-01

    In this study, the activity concentrations of terrestrial and anthropogenic radionuclides in the soil samples collected from Bafra Kizilirmak Delta were measured by using gamma spectrometry with an NaI(Tl) detector. The average values of activity concentrations of 238 U, 232 Th and 40 K were found to be 37.2±2.8, 33.7±3.1 and 413.0±59.8 Bq kg -1 , respectively. 137 Cs was also measured in some samples. It has a mean value of 13.8±1.0 Bq kg -1 . From the activity concentrations, the absorbed gamma dose rates in outdoor and the corresponding annual effective dose rates and external hazard index (Hex) were estimated. (authors)

  1. Measurement of the terrestrial and anthropogenic radionuclide concentrations in Bafra Kizilirmak delta (bird sanctuary) in Turkey.

    Science.gov (United States)

    Mutuk, Halil; Gümüs, Hasan; Turhan, Seref

    2014-01-01

    In this study, the activity concentrations of terrestrial and anthropogenic radionuclides in the soil samples collected from Bafra Kızılırmak Delta were measured by using gamma spectrometry with an NaI(Tl) detector. The average values of activity concentrations of (238)U, (232)Th and (40)K were found to be 37.2±2.8, 33.7±3.1 and 413.0±59.8 Bq kg(-1), respectively. (137)Cs was also measured in some samples. It has a mean value of 13.8±1.0 Bq kg(-1). From the activity concentrations, the absorbed gamma dose rates in outdoor and the corresponding annual effective dose rates and external hazard index (Hex) were estimated.

  2. Passive Sampler for Measurements of Atmospheric Nitric Acid Vapor (HNO3 Concentrations

    Directory of Open Access Journals (Sweden)

    Andrzej Bytnerowicz

    2001-01-01

    Full Text Available Nitric acid (HNO3 vapor is an important nitrogenous air pollutant responsible for increasing saturation of forests with nitrogen and direct injury to plants. The USDA Forest Service and University of California researchers have developed a simple and inexpensive passive sampler for monitoring air concentrations of HNO3. Nitric acid is selectively absorbed on 47-mm Nylasorb nylon filters with no interference from particulate NO3-. Concentrations determined with the passive samplers closely corresponded with those measured with the co-located honeycomb annular denuder systems. The PVC protective caps of standardized dimensions protect nylon filters from rain and wind and allow for reliable measurements of ambient HNO3 concentrations. The described samplers have been successfully used in Sequoia National Park, the San Bernardino Mountains, and on Mammoth Mountain in California.

  3. Measurement of concentration and size distribution of radon decay products in homes using air cleaners

    International Nuclear Information System (INIS)

    Montassier, N.; Hopke, P.K.; Shi, Y.; McCallum, B.

    1992-01-01

    By removing particles, air cleaners can also eliminate radon decay products. However, by removing the particles, the open-quotes unattachedclose quotes fraction of the radon progeny is increased leading to a higher dose per unit exposure. Thus, both the concentration and size distributions of the radon decay products are needed to evaluate air cleaners. Three types of room air cleaners, NO-RAD Radon Removal System, Electronic Air Cleaner and PUREFLOW Air Treatment System were tested in a single family home in Arnprior, Ontario (Canada). Semi-continuous measurements of radon gas concentration and radon decay product activity weighted size distribution were performed in the kitchen/dining room under real living conditions. The effects of air cleaners on both the concentration and size distribution of the radon decay products were measured, and their impact on the dose of radiation given to the lung tissue were examined

  4. Measurement of chloride-ion concentration with long-period grating technology

    Science.gov (United States)

    Tang, Jaw-Luen; Wang, Jian-Neng

    2007-06-01

    A simple and low-cost long-period fiber grating (LPG) sensor suited for chloride-ion concentration measurement is presented. The LPG sensor is found to be sensitive to the refractive index of the medium around the cladding surface of the sensing grating, thus offering the prospect of development of practical sensors such as an ambient index sensor or a chemical concentration indicator with high stability and reliability. We measured chloride ions in a typical concrete sample immersed in salt water solutions with different weight concentrations ranging from 0% to 25%. Results show that the LPG sensor exhibited a linear decrease in the transmission loss and resonance wavelength shift when the concentration increased. The measurement accuracy for the concentration of salt in water solution is estimated to be 0.6% and the limit of detection for chloride ions is about 0.04%. To further enhance its sensitivity for chloride concentrations, we coated a monolayer of colloidal gold nanoparticles as the active material on the grating surface of the LPG sensor. The operating principle of sensing is based on the sensitivity of localized surface plasmon resonance of self-assembled gold colloids on the grating section of the LPG. With this method, a factor of two increase in the sensitivity of detecting chemical solution concentrations was obtained. The advantages of this type of fiber-optic sensor are that it is compact, relatively simple to construct and easy to use. Moreover, the sensor has the potential capability for on-site, in vivo and remote sensing, and it has potential use as a disposable sensor.

  5. High frequency measurement of nitrate concentration in the Lower Mississippi River, USA

    Science.gov (United States)

    Duan, Shuiwang; Powell, Rodney T.; Bianchi, Thomas S.

    2014-11-01

    Nutrient concentrations in the Mississippi River have increased dramatically since the 1950s, and high frequency measurements on nitrate concentration are required for accurate load estimations and examinations on nitrate transport and transformation processes. This three year record of high temporal resolution (every 2-3 h) data clearly illustrates the importance of high frequency sampling in improving load estimates and resolving variations in nitrate concentration with river flow and tributary inputs. Our results showed large short-term (days to weeks) variations in nitrate concentration but with no diurnal patterns. A repeatable and pronounced seasonal pattern of nitrate concentration was observed, and showed gradual increases from the lowest values in September (during base-flow), to the highest in June - which was followed by a rapid decrease. This seasonal pattern was only moderately linked with water discharge, and more controlled by nitrogen transformation/export from watershed as well as mixing patterns of the two primary tributaries (the upper Mississippi and the Ohio Rivers), which have distinctly different nitrate concentrations and flow patterns. Based on continuous in situ flow measurements, we estimated 554-886 × 106 kg of nitrate-N was exported from the Mississippi River system during years 2004-2006, which was <9% and <16% lower than U.S. Geological Survey's (USGS) estimates using their LOADEST or composite methods, respectively. USGS methods generally overestimated nitrate loads during rising stages and underestimated the loads during falling stages. While changes in nitrate concentrations in large rivers are generally not as responsive to alterations in diurnal inputs and/or watershed hydrology as small rivers, high-frequency water quality sampling would help in monitoring short-term (days to weeks) variations in nutrient concentration patterns and thus improve the accuracy of nutrient flux estimates.

  6. Artifacts in measuring aerosol uptake kinetics: the roles of time, concentration and adsorption

    Directory of Open Access Journals (Sweden)

    L. H. Renbaum

    2011-07-01

    Full Text Available In laboratory studies of organic aerosol particles reacting with gas-phase oxidants, high concentrations of radicals are often used to study on the timescale of seconds reactions which may be occurring over days or weeks in the troposphere. Implicit in this approach is the assumption that radical concentration and time are interchangeable parameters, though this has not been established. Here, the kinetics of OH- and Cl-initiated oxidation reactions of model single-component liquid (squalane and supercooled (brassidic acid and 2-octyldodecanoic acid organic aerosols are studied by varying separately the radical concentration and the reaction time. Two separate flow tubes with residence times of 2 and 66 s are used, and [OH] and [Cl] are varied by adjusting either the laser photolysis fluence or the radical precursor concentration ([O3] or [Cl2], respectively used to generate the radicals. It is found that the rates measured by varying the radical concentration and the reaction time are equal only if the precursor concentrations are the same in the two approaches. Further, the rates depend on the concentrations of the precursor species with a Langmuir-type functional form suggesting that O3 and Cl2 saturate the surface of the liquid particles. It is believed that the presence of O3 inhibits the rate of OH reaction, perhaps by reacting with OH radicals or by O3 or intermediate species blocking surface sites, while Cl2 enhances the rate of Cl reaction by participating in a radical chain mechanism. These results have important implications for laboratory experiments in which high concentrations of gas-phase oxidants are used to study atmospheric reactions over short timescales and may explain the variability in recent measurements of the reactive uptake of OH on squalane particles in reactor systems used in this and other laboratories.

  7. Is lowering reducing sugars concentration in French fries an effective measure to reduce acrylamide concentration in food service establishments?

    NARCIS (Netherlands)

    Sanny, M.A.I.; Jinap, S.; Bakker, E.J.; Boekel, van M.A.J.S.; Luning, P.A.

    2012-01-01

    The objective of this study was to obtain insight into the actual effectiveness of lowering reducing sugars concentration in par-fried potato strips on the concentration and variation of acrylamide in French fries prepared in real-life situations in food service establishments. Acrylamide, frying

  8. Radon as an environmental risk: concentration measurements in family buildings at Cordoba city

    International Nuclear Information System (INIS)

    Bonzi, A.; Murua, C.; Martin, H.R.

    1992-01-01

    Measurements of radon concentration at homes are usual activities in the last years at the countries with uranium in their soils. On the other hand, the man's radiological protection about radiation is related to the environmental actions for a healthy life, but not much known for a public. The great quantities of ore with uranium can be an important source of irradiation when they are used as building materials. The soils are important too for the emanations of radon in the interior of buildings and for these reasons, the radon concentration measurements in Cordoba familiar houses were implemented in the summer of 1991. The Alpha Track Technique and the results obtained indicate the need of other measurements and a winter measurement for investigation variations of radon concentration. The typical values measured were low, about 4.13 Bq/m 3 if they are compared with other Argentine values measured. This paper discusses the procedure, techniques and criteria used in the work held in Cordoba city, Argentina. (Author)

  9. Evaluation of methodological aspects of digestibility measurements in ponies fed different haylage to concentrate ratios

    NARCIS (Netherlands)

    Schaafstra, F J W C; van Doorn, D A; Schonewille, J T; van Riet, M M J; Hendriks, W H

    2017-01-01

    Methodological aspects of digestibility measurements were studied in four Welsh pony geldings consuming haylage-based diets with increasing proportions of a pelleted concentrate according to a 4×4 Latin square design experiment. Ponies were fed four experimental, iso-energetic (net energy (NE)

  10. Evaluation of methodological aspects of digestibility measurements in ponies fed different haylage to concentrate ratios

    NARCIS (Netherlands)

    Schaafstra, F.J.W.C.; Doorn, van D.A.; Schonewille, J.T.; Riet, van M.M.J.; Visser, P.; Blok, M.C.; Hendriks, W.H.

    2017-01-01

    Methodological aspects of digestibility measurements were studied in four Welsh pony geldings consuming haylage-based diets with increasing proportions of a pelleted concentrate according to a 4×4 Latin square design experiment. Ponies were fed four experimental, iso-energetic (net energy (NE)

  11. Thoron and radon progeny concentration measurements using direct progeny sensors in HLNRAs of Kerala

    International Nuclear Information System (INIS)

    Mishra, R.; Prajith, R.; Gole, A.C.; Kanse, S.D.; Chougaonkar, M.P.; Sapra, B.K.; Mayya, Y.S.; Jayalekshmi, P.; Nair, Raghu Ram K.

    2010-01-01

    Passive Progeny Dosimeters (PPDs) were deployed in 500 houses in 3 villages namely Allapad, Chavara and Neendakara villages of Karunagapally Taluk of Kollam district of Kerala. Each PPD unit is a combination of a DTPS and a DRPS placed side-by-side for time integrated thoron and radon progeny concentration estimation respectively. The PPDs were suspended vertically in the rooms, such that the nearest distance from any wall or surface was at least 30 cm. These are, as of now, being exposed for a period of 3 months, after which they will be retrieved and analysed by chemical etching and track counting. Simultaneously, external gamma radiation measurements have also been made using a survey meter; these showed a variation from 13 to 118 μR/h in indoors and 21 to 213 μR/h in the outdoor environments. Spot measurements of thoron progeny concentrations were also made in 7 selected houses using the conventional grab filter-paper sampling technique at a flow-rate of 21 min -1 for 30 minutes, followed by alpha counting. The average thoron progeny concentration was found to be 2.0 ± 0.7 Bq m -3 . In the outdoor environment, filter-paper sampling was carried out for 2 hours at 21 min -1 and the thoron progeny concentration was measured as 2.96 Bq m -3 . To corroborate these measurements, a flow mode integrated sampler which uses the DTPS and DRPS elements was used

  12. Optimizing measurement sensitivity to facilitate monitoring environmental levels of Rn-daughter concentrations

    International Nuclear Information System (INIS)

    Keefe, D.J.; McDowell, W.P.; Groer, P.G.; Witek, R.T.

    1977-01-01

    In the measurement of environmental levels of radioactivity, the primary problem is the accumulation of a statistically meaningful number of counts within a reasonable period of time. In the case of measurements of airborne 222 Rn-daughter concentrations, the problem is further complicated by the particularly short half-life, 3.05 minutes, of RaA (Po 218 ). Since the Rn-daughters, (RaA, RaB [Pb 214 ] and RaC [Bi 214 ]) are of interest, the equations interrelating these Rn-daughter concentrations were derived from the laws of radioactive-series decay. These equations, although straightforward, are cumbersome to solve. To facilitate the efficient use of these equations, a computer program has been written which permits the calculation of Rn-daughter concentrations or expected counts for a given set of measurement parameters (flow rate and detector efficiencies). A subroutine then calculates the optimum pumping and counting times required to provide the number of counts necessary for acceptable statistics at environmental levels of 222 Rn-daughter concentrations. This subroutine contains a set of parameters, flow rate and efficiencies, that are fixed using realistic restrictions. The use of these optimized pumping and counting times results in maximum measurement sensitivity under realistic constraints

  13. Critical micelle concentration values for different surfactants measured with solid-phase microextraction fibers

    NARCIS (Netherlands)

    Haftka, Joris J H; Scherpenisse, Peter; Oetter, G??nter; Hodges, Geoff; Eadsforth, Charles V.; Kotthoff, Matthias; Hermens, Joop L M

    The amphiphilic nature of surfactants drives the formation of micelles at the critical micelle concentration (CMC). Solid-phase microextraction (SPME) fibres were used in the present study to measure CMC values of twelve nonionic, anionic, cationic and zwitterionic surfactants. The SPME derived CMC

  14. Using Conductivity Measurements to Determine the Identities and Concentrations of Unknown Acids: An Inquiry Laboratory Experiment

    Science.gov (United States)

    Smith, K. Christopher; Garza, Ariana

    2015-01-01

    This paper describes a student designed experiment using titrations involving conductivity measurements to identify unknown acids as being either HCl or H[subscript 2]SO[subscript 4], and to determine the concentrations of the acids, thereby improving the utility of standard acid-base titrations. Using an inquiry context, students gain experience…

  15. Optical sensor technology for simultaneous measurement of particle speed and concentration of micro sized particles

    DEFF Research Database (Denmark)

    Clausen, Casper; Han, Anpan; Kristensen, Martin

    2013-01-01

    Experimental characterization of a sensor technology that can measure particle speed and concentration simultaneously in liquids and gases is presented here. The basic sensor principle is based on an optical element that shapes a light beam into well-defined fringes. The technology can be described...

  16. Measurement of uranium concentration by molecular absorption spectrophotometry by means optical fibers

    International Nuclear Information System (INIS)

    Gauna, Alberto C.; Pascale, Ariel A.

    1996-01-01

    An on-line method for measuring the concentration of uranium in uranyl nitrate-nitric acid aqueous solutions is described. The method is based on molecular absorption spectrophotometry with transmission of light by means of optical fibers. It is ideally suited for control and processes development applications. (author)

  17. Planar measurements of velocity and concentration of turbulent mixing in a T-junction

    DEFF Research Database (Denmark)

    Ingvorsen, Kristian Mark; Meyer, Knud Erik; Nielsen, N. F.

    Turbulent mixing of two isothermal air streams in a T-junction of square ducts are investigated. Three dimensional velocity fields and turbulent kinetic energy are measured with stereoscopic Particle Image Velocimetry (PIV). The concentration field is obtained with a planar Mie scattering technique...

  18. Testing of a uranium downhole logging system to measure in-situ plutonium concentrations in sediments

    International Nuclear Information System (INIS)

    Kasper, R.B.; Kay, M.A.; Bruns, L.E.; Stokes, J.A.; Steinman, D.K.; Adams, J.

    1980-11-01

    A prototype urainium borehole logging system, developed for uranium exploration, was modified for Pu assay and testing at the site. It uses the delayed fission neutron (DFN) method. It was tested in a retired Pu facility, the 216-Z-1A Crib. General agreement between laboratory determined Pu concentrations in sediment samples and neutron flux measurements was found for the relative distribution with depth

  19. To Error Problem Concerning Measuring Concentration of Carbon Oxide by Thermo-Chemical Sen

    Directory of Open Access Journals (Sweden)

    V. I. Nazarov

    2007-01-01

    Full Text Available The paper gives additional errors in respect of measuring concentration of carbon oxide by thermo-chemical sensors. A number of analytical expressions for calculation of error data and corrections for environmental factor deviations from admissible ones have been obtained in the paper

  20. Water leak detection in sodium heated steam generators through measurement of hydrogen concentration in sodium

    International Nuclear Information System (INIS)

    Cambillard, E.; Lacroix, A.; Martin, P.; Viala, J.

    1980-07-01

    This report includes a description of apparatus for measuring hydrogen concentration in the secondary sodium system of the PHENIX reactor. The calibration method and results obtained since the commissioning of the reactor are also described. Mention is made of improvements to be built into SUPER PHENIX [fr

  1. Concentration Measurements of Suspended Load using ADV with Influence of the Particle Size

    Science.gov (United States)

    Schwarzwälder, Kordula

    2017-04-01

    ADV backscatter data can be used under certain conditions to gain information about the concentrations of suspended loads. This was shown in many studies before (Fugate and Friedrichs 2002; Chanson et al 2008; Ha et al. 2009). This paper reports on a pre-study to investigate the influence of particle size on concentration measurements for suspended sediment load with ADV. The study was conducted in a flume in the Oskar-von-Miller-Institute using fresh water from a river including the natural suspended load. The ADV used in the experiments was a Vectrino Profiler (Nortek). In addition water samples were taken for TSS and TOC. For the measurements a surge was generated in the flume to ensure that also particles of larger size will be present in the water phase. The measurements and samples were taken during the whole surge event. Therefore we were able to find a good correlation between the backscatter data of the ADV and the TSS as well as TOC results. For the decreasing part of the flow event the concentration of TOC in the suspended load of the water phase is decreasing much slower than the TSS and results in a damped decrease of the backscatter values. This means that the results for concentration measurements might be slightly influenced by the size of the particles. Further evaluations of measurements conducted with a LISST SL (Sequoia) will be investigated to show the trend of the particle sizes during this process and fortify this result. David C. Fugate, Carl T. Friedrichs, Determining concentration and fall velocity of estuarine particle populations using ADV, OBS and LISST, Continental Shelf Research, Volume 22, Issues 11-13, 2002 H.K. Ha, W.-Y. Hsu, J.P.-Y. Maa, Y.Y. Shao, C.W. Holland, Using ADV backscatter strength for measuring suspended cohesive sediment concentration, Continental Shelf Research, Volume 29, Issue 10, 2009 Hubert Chanson, Maiko Takeuchi, Mark Trevethan, Using turbidity and acoustic backscatter intensity as surrogate measures of

  2. Absolute choline concentration measured by quantitative proton MR spectroscopy correlates with cell density in meningioma

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Qiang [University of Tsukuba, Department of Neurosurgery, Institute of Clinical Medicine, Tsukuba Science City, Ibaraki (Japan)]|[West China Hospital of Sichuan University, Huaxi MR Research Center, Department of Radiology, Chengdu (China); Shibata, Yasushi; Kawamura, Hiraku; Matsumura, Akira [University of Tsukuba, Department of Neurosurgery, Institute of Clinical Medicine, Tsukuba Science City, Ibaraki (Japan); Isobe, Tomonori [Kitasato University, Department of Medical Technology, School of Allied Health Sciences, Minato, Tokyo (Japan); Anno, Izumi [University of Tsukuba, Department of Radiology, Institute of Clinical Medicine, Tsukuba, Ibaraki (Japan); Gong, Qi-Yong [West China Hospital of Sichuan University, Huaxi MR Research Center, Department of Radiology, Chengdu (China)]|[University of Liverpool, Division of Medical Imaging, Faculty of Medicine, Liverpool (United Kingdom)

    2009-01-15

    This study was aimed to investigate the relationship between quantitative proton magnetic resonance spectroscopy (1H-MRS) and pathological changes in meningioma. Twenty-two meningioma cases underwent single voxel 1H-MRS (point-resolved spectroscopy sequence, repetition time/echo time = 2,000 ms/68, 136, 272 ms). Absolute choline (Cho) concentration was calculated using tissue water as the internal reference and corrected according to intra-voxel cystic/necrotic parts. Pathological specimens were stained with MIB-1 antibody to measure cell density and proliferation index. Correlation analysis was performed between absolute Cho concentration and cell density and MIB-1 labeled proliferation index. Average Cho concentration of all meningiomas before correction was 2.95 {+-} 0.86 mmol/kg wet weight. It was increased to 3.23 {+-} 1.15 mmol/kg wet weight after correction. Average cell density of all meningiomas was 333 {+-} 119 cells/HPF, and average proliferation index was 2.93 {+-} 5.72%. A linear, positive correlation between cell density and Cho concentration was observed (r = 0.650, P = 0.001). After correction of Cho concentration, the correlation became more significant (r = 0.737, P < 0.001). However, no significant correlation between Cho concentration and proliferation index was found. There seemed to be a positive correlation trend after correction of Cho concentration but did not reach significant level. Absolute Cho concentration, especially Cho concentration corrected according to intra-voxel cystic/necrotic parts, reflects cell density of meningioma. (orig.)

  3. Historical occupational trichloroethylene air concentrations based on inspection measurements from Shanghai, China.

    Science.gov (United States)

    Friesen, Melissa C; Locke, Sarah J; Chen, Yu-Cheng; Coble, Joseph B; Stewart, Patricia A; Ji, Bu-Tian; Bassig, Bryan; Lu, Wei; Xue, Shouzheng; Chow, Wong-Ho; Lan, Qing; Purdue, Mark P; Rothman, Nathaniel; Vermeulen, Roel

    2015-01-01

    Trichloroethylene (TCE) is a carcinogen that has been linked to kidney cancer and possibly other cancer sites including non-Hodgkin lymphoma. Its use in China has increased since the early 1990s with China's growing metal, electronic, and telecommunications industries. We examined historical occupational TCE air concentration patterns in a database of TCE inspection measurements collected in Shanghai, China to identify temporal trends and broad contrasts among occupations and industries. Using a database of 932 short-term, area TCE air inspection measurements collected in Shanghai worksites from 1968 through 2000 (median year 1986), we developed mixed-effects models to evaluate job-, industry-, and time-specific TCE air concentrations. Models of TCE air concentrations from Shanghai work sites predicted that exposures decreased 5-10% per year between 1968 and 2000. Measurements collected near launderers and dry cleaners had the highest predicted geometric means (GM for 1986 = 150-190 mg m(-3)). The majority (53%) of the measurements were collected in metal treatment jobs. In a model restricted to measurements in metal treatment jobs, predicted GMs for 1986 varied 35-fold across industries, from 11 mg m(-3) in 'other metal products/repair' industries to 390 mg m(-3) in 'ships/aircrafts' industries. TCE workplace air concentrations appeared to have dropped over time in Shanghai, China between 1968 and 2000. Understanding differences in TCE concentrations across time, occupations, and industries may assist future epidemiologic studies in China. Published by Oxford University Press on behalf of the British Occupational Hygiene Society 2014.

  4. A rapid approach for measuring silver nanoparticle concentration and dissolution in seawater by UV-Vis.

    Science.gov (United States)

    Sikder, Mithun; Lead, Jamie R; Chandler, G Thomas; Baalousha, Mohammed

    2018-03-15

    Detection and quantification of engineered nanoparticles (NPs) in environmental systems is challenging and requires sophisticated analytical equipment. Furthermore, dissolution is an important environmental transformation process for silver nanoparticles (AgNPs) which affects the size, speciation and concentration of AgNPs in natural water systems. Herein, we present a simple approach for the detection, quantification and measurement of dissolution of PVP-coated AgNPs (PVP-AgNPs) based on monitoring their optical properties (extinction spectra) using UV-vis spectroscopy. The dependence of PVP-AgNPs extinction coefficient (ɛ) and maximum absorbance wavelength (λ max ) on NP size was experimentally determined. The concentration, size, and extinction spectra of PVP-AgNPs were characterized during dissolution in 30ppt synthetic seawater. AgNPs concentration was determined as the difference between the total and dissolved Ag concentrations measured by inductively coupled plasma-mass spectroscopy (ICP-MS); extinction spectra of PVP-AgNPs were monitored by UV-vis; and size evolution was monitored by atomic force microscopy (AFM) over a period of 96h. Empirical equations for the dependence of maximum absorbance wavelength (λ max ) and extinction coefficient (ɛ) on NP size were derived. These empirical formulas were then used to calculate the size and concentration of PVP-AgNPs, and dissolved Ag concentration released from PVP-AgNPs in synthetic seawater at variable particle concentrations (i.e. 25-1500μgL -1 ) and in natural seawater at particle concentration of 100μgL -1 . These results suggest that UV-vis can be used as an easy and quick approach for detection and quantification (size and concentration) of sterically stabilized PVP-AgNPs from their extinction spectra. This approach can also be used to monitor the release of Ag from PVP-AgNPs and the concurrent NP size change. Finally, in seawater, AgNPs dissolve faster and to a higher extent with the decrease in NP

  5. Determination of six polyether antibiotic residues in foods of animal origin by solid phase extraction combined with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Ha, Jing; Song, Ge; Ai, Lian-Feng; Li, Jian-Chen

    2016-04-01

    A new method using solid phase extraction (SPE) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed for the determination of six polyether antibiotics, including lasalocid, salinomycin, monensin, narasin, madubamycin and nigericin residues, in foods of animal origin. The samples were extracted with acetonitrile and purified by ENVI-Carb SPE columns after comparing the impurity effect and maneuverability of several SPE cartridges. Subsequently, the analytes were separated on a Hypersil Gold column (2.1×150mm, 5μm) and analyzed by MS/MS detection. The limit of quantization (LOQ) for milk and chicken was 0.4μg/kg, and for chicken livers and eggs, it was 1μg/kg. The linearity was satisfactory with a correlation coefficient of >0.9995 at concentrations ranging from 2 to 100μg/L. The average recoveries of the analytes fortified at three levels ranged from 68.2 to 114.3%, and the relative standard deviations ranged from 4.5 to 12.1%. The method was suitable for quantitative analysis and confirmation of polyether antibiotic residues in foods of animal origin. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Study of sulfonated polyether ether ketone with pendant lithiated fluorinated sulfonic groups as ion conductive binder in lithium-ion batteries

    Science.gov (United States)

    Wei, Zengbin; Xue, Lixin; Nie, Feng; Sheng, Jianfang; Shi, Qianru; Zhao, Xiulan

    2014-06-01

    In an attempt to reduce the Li+ concentration polarization and electrolyte depletion from the electrode porous space, sulfonated polyether ether ketone with pendant lithiated fluorinated sulfonic groups (SPEEK-FSA-Li) is prepared and attempted as ionic conductivity binder. Sulfonated aromatic poly(ether ether ketone) exhibits strong adhesion and chemical stability, and lithiated fluorinated sulfonic side chains help to enhance the ionic conductivity and Li+ ion diffusion due to the charge delocalization over the sulfonic chain. The performances are evaluated by cyclic voltammetry, electrochemical impedance spectroscopy, charge-discharge cycle testing, 180° peel testing, and compared with the cathode prepared with polyvinylidene fluoride binder. The electrode prepared with SPEEK-FSA-Li binder forms the relatively smaller resistances of both the SEI and the charge transfer of lithium ion transport. This is beneficial to lithium ion intercalation and de-intercalation of the cathode during discharging-charging, therefore the cell prepared with SPEEK-FSA-Li shows lower charge plateau potential and higher discharge plateau potential. Compared with PVDF, the electrode with ionic binder shows smaller decrease in capacity with the increasing of cycle rate. Meanwhile, adhesion strength of electrode prepared with SPEEK-FSA-Li is more than five times greater than that with PVDF.

  7. Numerical investigation of the effect of particle concentration on particle measurement by digital holography

    Science.gov (United States)

    Zhao, Huafeng; Zhou, Binwu; Wu, Xuecheng; Wu, Yingchun; Gao, Xiang; Gréhan, Gérard; Cen, Kefa

    2014-04-01

    Digital holography plays a key role in particle field measurement, and appears to be a strong contender as the next-generation technology for diagnostics of 3D particle field. However, various recording parameters, such as the recording distance, the particle size, the wavelength, the size of the CCD chip, the pixel size and the particle concentration, will affect the results of the reconstruction, and may even determine the success or failure of a measurement. This paper presents a numerical investigation on the effect of particle concentration, the volume depth to evaluate the capability of digital holographic microscopy. Standard particles holograms with all known recording parameters are numerically generated by using a common procedure based on Lorenz-Mie scattering theory. Reconstruction of those holograms are then performed by a wavelet-transform based method. Results show that the reconstruction efficiency decreases quickly until particle concentration reaches 50×104 (mm-3), and decreases linearly with the increase of particle concentration from 50 × 104 (mm-3) to 860 × 104 (mm-3) in the same volume. The first half of the line waves larger than the second half. It also indicates that the increase of concentration leads the rise in average diameter error and z position error of particles. Besides, the volume depth also plays a key role in reconstruction.

  8. Measurement of particulate concentrations produced during bulk material handling at the Tarragona harbor

    Energy Technology Data Exchange (ETDEWEB)

    Artinano, B.; Gomez-Moreno, F.J.; Pujadas, M.; Moreno, N.; Alastuey, A.; Querol, X.; Martin, F.; Guerra, A.; Luaces, J.A.; Basora, J. [CIEMAT, Madrid (Spain)

    2007-09-15

    Bulk material handling can be a significant source of particles in harbor areas. The atmospheric impact of a number of loading/unloading activities of diverse raw materials has been assessed from continuous measurements of ambient particle concentrations recorded close to the emission sources. Two experimental campaigns have been carried out in the Tarragona port to document the impact of specific handling operations and bulk materials. Dusty bulk materials such as silica-manganese powder, tapioca, coal, clinker and lucerne were dealt with during the experiments. The highest impacts on ambient particle concentrations were recorded during handling of clinker. For this material and silica-manganese powder, high concentrations were recorded in the fine grain size ({lt}2.5 {mu}m). The lowest impacts on particulate matter concentrations were recorded during handling of tapioca and lucerne, mainly in the coarse grain size (2-5-10 {mu} m). The effectiveness of several emission abatement measures, such as ground watering to diminish coal particle resuspension, was demonstrated to reduce ambient concentrations by up to two orders of magnitude. The importance of other good practices in specific handling operations, such as controlling the height of the shovel discharge, was also evidenced by these experiments. The results obtained can be further utilized as a useful experimental database for emission factor estimations.

  9. Fluorescence measurement of atomic oxygen concentration in a dielectric barrier discharge

    Science.gov (United States)

    Dvořák, P.; Mrkvičková, M.; Obrusník, A.; Kratzer, J.; Dědina, J.; Procházka, V.

    2017-06-01

    Concentration of atomic oxygen was measured in a volume dielectric barrier discharge (DBD) ignited in mixtures of Ar + O2(+ H2) at atmospheric pressure. Two-photon absorption laser induced fluorescence (TALIF) of atomic oxygen was used and this method was calibrated by TALIF of Xe in a mixture of argon and a trace of xenon. The calibration was performed at atmospheric pressure and it was shown that quenching by three-body collisions has negligible effect on the life time of excited Xe atoms. The concentration of atomic oxygen in the DBD was around 1021 m-3 and it was stable during the whole discharge period. The concentration did not depend much on the electric power delivered to the discharge provided that the power was sufficiently high so that the visible discharge filled the whole reactor volume. Both the addition of hydrogen or replacing of argon by helium led to a significant decrease of atomic oxygen concentration. The TALIF measurements of O concentration levels in the DBD plasma performed in this work are made use of e.g. in the field analytical chemistry. The results contribute to understanding the processes of analyte hydride preconcentration and subsequent atomization in the field of trace element analysis where DBD plasma atomizers are employed.

  10. Rapid measurement of plasma free fatty acid concentration and isotopic enrichment using LC/MS

    Science.gov (United States)

    Persson, Xuan-Mai T.; Błachnio-Zabielska, Agnieszka Urszula; Jensen, Michael D.

    2010-01-01

    Measurements of plasma free fatty acids (FFA) concentration and isotopic enrichment are commonly used to evaluate FFA metabolism. Until now, gas chromatography-combustion-isotope ratio mass spectrometry (GC/C/IRMS) was the best method to measure isotopic enrichment in the methyl derivatives of 13C-labeled fatty acids. Although IRMS is excellent for analyzing enrichment, it requires time-consuming derivatization steps and is not optimal for measuring FFA concentrations. We developed a new, rapid, and reliable method for simultaneous quantification of 13C-labeled fatty acids in plasma using high-performance liquid chromatography-mass spectrometry (HPLC/MS). This method involves a very quick Dole extraction procedure and direct injection of the samples on the HPLC system. After chromatographic separation, the samples are directed to the mass spectrometer for electrospray ionization (ESI) and analysis in the negative mode using single ion monitoring. By employing equipment with two columns connected parallel to a mass spectrometer, we can double the throughput to the mass spectrometer, reducing the analysis time per sample to 5 min. Palmitate flux measured using this approach agreed well with the GC/C/IRMS method. This HPLC/MS method provides accurate and precise measures of FFA concentration and enrichment. PMID:20526002

  11. Measurement of particle size distribution and mass concentration of nuclear fuel aerosols

    International Nuclear Information System (INIS)

    Pickering, S.

    1982-01-01

    The particle size distribution and particle mass concentration of a nuclear fuel aerosol is measured by admitting the aerosol into a vertically-extending container, positioning an alpha particle detector within the container so that its window is horizontal and directed vertically, stopping the admission of aerosol into the container, detecting the alpha-activity of the particles of the aerosol sedimenting onto the detector window (for example in a series of equal time intervals until a constant level is reached), and converting the alpha-activity measurements into particle size distribution and/or particle mass concentration measurements. The detector is attached to a pivotted arm and by raising a counterweight can be lowered from the container for cleaning. (author)

  12. Measurements of ammonia concentrations, fluxes and dry deposition velocities to a spruce forest 1991-1995

    DEFF Research Database (Denmark)

    Andersen, H.V.; Hovmand, M.F.; Hummelshøj, P.

    1999-01-01

    The dry deposition velocities and fluxes of ammonia have been estimated from measurements of the vertical gradient of ammonia and micrometeorology above a spruce forest in western Jutland, Denmark. Measurements have been made in seven periods, each lasting about one week and covering all seasons...... measuring period characterized by easterly winds with dry conditions and high ammonia concentrations, and the emissions might relate to evaporation from ammonia saturated surfaces or emission from mineralization in the forest soil. In general, relatively high net deposition velocities were observed during...... at conditions with easterly winds, the air have passed central Jutland with large emission areas. Some of the relatively low deposition velocities or emissions were observed during conditions with low ammonia concentration and westerly winds. These observations might relate to a compensation point of the forest...

  13. Applicability of Stokes method for measuring viscosity of mixtures with concentration gradient

    Directory of Open Access Journals (Sweden)

    César Medina

    2017-12-01

    Full Text Available After measuring density and viscosity of a mixture of glycerin and water contained in a vertical pipe, a variation of these properties according to depth is observed. These gradients are typical of non-equilibrium states related to the lower density of water and the fact that relatively long times are necessary to achieve homogeneity. In the same pipe, the falling velocity of five little spheres is measured as a function of depth, and then a numerical fit is performed which agrees very well with experimental data. Based on the generalization of these results, the applicability of Stokes method is discussed for measuring viscosity of mixtures with a concentration gradient.

  14. Measurements of Radon Concentration in Several Wards of the University Clinical Center of Kosovo...

    OpenAIRE

    , Y. Halimi; , S. Kadiri; , G. Hodolli; , B. Xhafa; , A. Jonuzaj

    2016-01-01

    Understanding that what’s the level of environment pollution from radioactive pollutant in some wards of UCCK (University Clinical Center of Kosovo) in Prishtina are made measurements of α radiation which is the product of 222Rn and have been read doses of TLD to some staff workers in three wards of UCCK. All this is done to see the risk level of possible pollution. Concentration of radon 222Rn is measured with device CRM-510 portable instruments. During the measurements the apparatus has rec...

  15. Plasma assisted measurements of alkali metal concentrations in pressurized combustion processes

    International Nuclear Information System (INIS)

    Hernberg, R.; Haeyrinen, V.

    1995-01-01

    The plasma assisted method for continuous measurement of alkali metal concentrations in product gas flows of pressurized energy processes will be tested and applied at the 1.6 MW PFBC/G facility at Delft University of Technology in the Netherlands. Measurements will be performed during 1995 and 1996 at different stages of the research programme. The results are expected to give information about the influence of different process conditions on the generation of alkali metal vapours, the comparison of different methods for alkali measurement and the specific performance of our system. The project belongs to the Joule II extension program under contract JOU2-CT93-0431. (author)

  16. Measurements of radon concentrations in a sample representative of housing in Franche-Comte

    International Nuclear Information System (INIS)

    Aury, K.; Clinard, F.; Tillier, C.; Catelinois, O.; Pirard, P.; Aury, K.; Nourry, L.; Hochart, A.

    2008-01-01

    Three departments on four ones in Franche-Comte are classified at risk for radon: measurements are so compulsory in establishments receiving public. For the residential sector, no obligation of measurement are compulsory when french people spend 70% of their time in it. The data concerning homes are fragmentary and deserve to be completed. This campaign of measurements has confirmed the existence of radon in relatively high concentrations in Franche-Comte, including the sedimentary areas, justifying the necessity to realize a precise evaluation of the sanitary impact. The model will allow to study different strategies to reduce radon in houses. (N.C.)

  17. Measurements and statistical analyses of indoor radon concentrations in Tokyo and surrounding areas

    International Nuclear Information System (INIS)

    Sugiura, Shiroharu; Suzuki, Takashi; Inokoshi, Yukio

    1995-01-01

    Since the UNSCEAR report published in 1982, radiation exposure to the respiratory tract due to radon and its progeny has been regarded as the single largest contributor to the natural radiation exposure of the general public. In Japan, the measurement of radon gas concentrations in many types of buildings have been surveyed by national and private institutes. We also carried out the measurement of radon gas concentrations in different types of residential buildings in Tokyo and its adjoining prefectures from October 1988 to September 1991, to evaluate the potential radiation risk of the people living there. One or two simplified passive radon monitors were set up in each of the 34 residential buildings located in the above-mentioned area for an exposure period of 3 months each. Comparing the average concentrations in the buildings of different materials and structures, those in the concrete steel buildings were always higher than those in the wooden and the prefabricated mortared buildings. The radon concentrations were proved to become higher in autumn and winter, and lower in spring and summer. Radon concentrations in an underground room of a concrete steel building showed the highest value throughout our investigation, and statistically significant seasonal variation was detected by the X-11 method developed by the U.S. Bureau of Census. The values measured in a room at the first floor of the same concrete steel building also showed seasonal variation, but the phase of variation was different. Another multivariate analysis suggested that the building material and structure are the most important factors concerning the levels of radon concentration among other factors such as the age of the building and the use of ventilators. (author)

  18. Predicting and measurement of pH of seawater reverse osmosis concentrates

    KAUST Repository

    Waly, Tarek

    2011-10-01

    The pH of seawater reverse osmosis plants (SWRO) is the most influential parameter in determining the degree of supersaturation of CaCO3 in the concentrate stream. For this, the results of pH measurements of the concentrate of a seawater reverse osmosis pilot plant were compared with pH calculations based on the CO2-HCO3 --CO3 2- system equilibrium equations. Results were compared with two commercial software programs from membrane suppliers and also the software package Phreeqc. Results suggest that the real concentrate pH is lower than that of the feed and that none of the used programs was able to predict correctly real pH values. In addition, the effect of incorporating the acidity constant calculated for NaCl medium or seawater medium showed a great influence on the concentrate pH determination. The HCO3 - and CO3 2- equilibrium equation using acidity constants developed for seawater medium was the only method able to predict correctly the concentrate pH. The outcome of this study indicated that the saturation level of the concentrate was lower than previously anticipated. This was confirmed by shutting down the acid and the antiscalants dosing without any signs of scaling over a period of 12 months. © 2011 Elsevier B.V.

  19. Concentration and measuring Platinum Group Elements (PGE) Transfer Factor in soil and vegetations

    International Nuclear Information System (INIS)

    Adibah Sakinah Oyub

    2012-01-01

    This study was conducted to determine the concentration and to measure platinum group elements (PGE) transfer factor in environmental samples of roadside soil and vegetation. The use of vehicle catalytic converter has released platinum group elements (PGE) and other gases into the environment. Thus, roadside soil and plants were exposed to this element and has become the medium for the movement of this elements. Samples of roadside soil and vegetation were taken at various locations in UKM Bangi Toll and the concentration of platinum group elements (PGE) is determined using mass spectrometry-inductively coupled plasma (ICP-MS). Overall, the concentrations of platinum group elements (PGE), which is the element platinum (Pt) in soil was 0.016 ± 0.036 μgg -1 . While the concentration of the elements palladium (Pd) was 0.079 ± 0.019 μgg -1 and element rhodium (Rh) is at a concentration of 0.013 ± 0.020 μgg -1 . Overall, the transfer factor for the element platinum (Pt) is 1. While the transfer factor of the element palladium (Pd) is 0.96 and the element rhodium (Rh) is 1.11. In conclusion, the concentration of platinum group elements (PGE) in soils have increased. (author)

  20. Measurements of Indoor Radon Concentrations in Chaiya and Tha Chana Districts, Surat Thani Province, Thailand

    International Nuclear Information System (INIS)

    Titipornpun, K.; Titipornpun, A.; Sola, P.; Bhongsuwan, T.

    2014-01-01

    Chaiya and Tha Chana districts of Surat Thani province are located in the areas with high equivalent uranium at ground surface, which have been identified as sources of radon. A survey measurement of indoor radon concentrations was carried out in 248 houses, using CR-39 detectors in closed cups. All of the detectors were exposed to radon for forty days. After the exposure, the alpha tracks were made visible by chemical etching and counted manually under an optical microscope. The indoor concentrations in Chaiya district were found to vary from the minimum to the maximum of 4 Bq.m -3 to 88 Bq.m -3 , respectively. In Tha Chana district, the concentrations of indoor radon were varied from the minimum of 4 Bq.m -3 to the maximum of 159 Bq.m -3 . The geometric mean of indoor radon concentrations in Chaya and Tha Chana districts were found to be 26±2 Bq.m -3 and 30±2 Bq.m -3 , respectively. The overall geometric mean in the surveyed areas was 28±2 Bq.m -3 . Only in two houses (1%), the concentrations (151 and 159 Bq.m -3 ) were found to be higher than the action level recommended by the US EPA (148 Bq.m -3 ). Most houses (94%) have natural ventilation by keeping doors and windows opened during the daytime. This ventilation likely causes the low level of indoor radon concentrations.

  1. Measurements of radon daughter concentrations in structures built on or near uranium mine tailings

    International Nuclear Information System (INIS)

    Haywood, F.F.; Kerr, G.D.; Goldsmith, W.A.; Perdue, P.T.; Thorngate, J.H.

    1976-01-01

    A technique is discussed that has been used to measure air concentrations of short-lived daughters of 222 Rn in residential and commercial structures built on or near uranium mill tailings in the western part of the United States. In this technique, the concentrations of RaA, RaB, and RaC are calculated from one integral count of the RaA and two integral counts of the RaC' alpha-particle activity collected on a filter with an air sampling device. A computer program is available to calculate the concentrations of RaA, RaB, and RaC in air and to estimate the accuracy in these calculated concentrations. This program is written in the BASIC language. Also discussed in this paper are the alpha-particle spectrometer used to count activity on the air filters and the results of our radon daughter measurements in Colorado, Utah, and New Mexico. These results and results of other measurements discussed in a companion paper are now being used in a comprehensive study of potential radiation exposures to the public from uranium mill tailing piles

  2. Measurement of radon concentration in dwellings in the region of highest lung cancer incidence in India

    International Nuclear Information System (INIS)

    Zoliana, B.; Rohmingliana, P.C.; Sahoo, B.K.; Mayya, Y.S.

    2015-01-01

    Monitoring of radon exhalation from soil and its concentration in indoor is found to be helpful in many investigations such as health risk assessment and others as radiation damage to bronchial cells which eventually can be the second leading cause of lung cancer next to smoking. The fact that Aizawl District, Mizoram, India has the highest lung cancer incidence rates among males and females in Age Adjusted Rate (AAR) in India as declared by Population Based Cancer Registry Report 2008 indicates the need for quantification of radon and its anomalies attached to it. Measurement of radon concentration had been carried out inside the dwellings in Aizawl district, Mizoram. A time integrated method of measurement was employed by using a solid state nuclear track detector (SSNTD) type (LR-115 films) kept in a twin cup dosimeter for measurement of concentration of radon and thoron. The dosimeters were suspended over bed rooms or living rooms in selected dwellings. They were deployed for a period of about 120 days at a time in 63 houses which were selected according to their place of location viz. fault region, places where fossil remains were found and geologically unidentified region. After the desired period of exposure, the detectors were retrieved and chemically etched which were then counted by using a spark counter. The recorded nuclear tract densities are then converted into air concentrations of Radon and Thoron

  3. Indoor and outdoor Radon concentration measurements in Sivas, Turkey, in comparison with geological setting

    Energy Technology Data Exchange (ETDEWEB)

    Mihci, Metin [Iller Bankasi, Etud Plan ve Yol Dairesi, Opera, 06053 Ankara (Turkey); Buyuksarac, Aydin [Canakkale Onsekiz Mart University, Department of Geophysical Engineering, 17020, Canakkale (Turkey); Aydemir, Attila, E-mail: aydemir@tpao.gov.t [Turkiye Petrolleri A.O. Mustafa, Kemal Mah. 2. Cad. No: 86, 06100 Sogutozu, Ankara (Turkey); Celebi, Nilgun [Cekmece Nuclear Research and Training Centre (CNAEM), Cekmece, Istanbul (Turkey)

    2010-11-15

    Indoor and soil gas Radon ({sup 222}Rn) concentration measurements were accomplished in two stages in Sivas, a central eastern city in Turkey. In the first stage, CR-39 passive nuclear track detectors supplied by the Turkish Atomic Energy Authority (TAEA) were placed in the selected houses throughout Sivas centrum in two seasons; summer and winter. Before the setup of detectors, a detailed questionnaire form was distributed to the inhabitants of selected houses to investigate construction parameters and properties of the houses, and living conditions of inhabitants. Detectors were collected back two months later and analysed at TAEA laboratories to obtain indoor {sup 222}Rn gas concentration values. In the second stage, soil gas {sup 222}Rn measurements were performed using an alphameter near the selected houses for the indoor measurements. Although {sup 222}Rn concentrations in Sivas were quite low in relation with the allowable limits, they are higher than the average of Turkey. Indoor and soil gas {sup 222}Rn concentration distribution maps were prepared seperately and these maps were applied onto the surface geological map. In this way, both surveys were correlated with the each other and they were interpreted in comparison with the answers of questionnaire and the geological setting of the Sivas centrum and the vicinity.

  4. Measures of ozone concentrations using passive sampling in forests of South Western Europe

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, M.J. [Fundacion CEAM, Charles R. Darwin 14, Parc Tecnologic, E-46980 Paterna, Valencia (Spain)]. E-mail: mjose@ceam.es; Calatayud, V. [Fundacion CEAM, Charles R. Darwin 14, Parc Tecnologic, E-46980 Paterna, Valencia (Spain); Sanchez-Pena, G. [Servicio de Proteccion de los Montes contra Agentes Nocivos, Direccion General para la Biodiversidad, Ministerio de Medio Ambiente, Gran Via de San Francisco, 4, E-28005, Madrid (Spain)

    2007-02-15

    Ambient ozone concentrations were measured with passive samplers in the framework of the EU and UN/ECE Level II forest monitoring programme. Data from France, Italy, Luxembourg, Spain and Switzerland are reported for 2000-2002, covering the period from April to September. The number of plots increased from 67 in 2000 to 83 in 2002. The year 2001 experienced the highest ozone concentrations, reflecting more stable summer meteorological conditions. Average 6-month ozone concentrations above 45 ppb were measured this year in 40.3% of the plots, in contrast with the less than 21% measured in the other 2 years. Gradients of increasing ozone levels were observed from North to South and with altitude. Comments are made on the regional trends and on the time frame of the higher ozone episodes. Also, some recommendations enabling a better comparison between plots are provided. - Ozone concentrations in forested areas of SW Europe during the period 2000-2002 showed highest values in 2001, as well as a tendency to increase towards the South and with altitude.

  5. Measures of ozone concentrations using passive sampling in forests of South Western Europe

    International Nuclear Information System (INIS)

    Sanz, M.J.; Calatayud, V.; Sanchez-Pena, G.

    2007-01-01

    Ambient ozone concentrations were measured with passive samplers in the framework of the EU and UN/ECE Level II forest monitoring programme. Data from France, Italy, Luxembourg, Spain and Switzerland are reported for 2000-2002, covering the period from April to September. The number of plots increased from 67 in 2000 to 83 in 2002. The year 2001 experienced the highest ozone concentrations, reflecting more stable summer meteorological conditions. Average 6-month ozone concentrations above 45 ppb were measured this year in 40.3% of the plots, in contrast with the less than 21% measured in the other 2 years. Gradients of increasing ozone levels were observed from North to South and with altitude. Comments are made on the regional trends and on the time frame of the higher ozone episodes. Also, some recommendations enabling a better comparison between plots are provided. - Ozone concentrations in forested areas of SW Europe during the period 2000-2002 showed highest values in 2001, as well as a tendency to increase towards the South and with altitude

  6. The doping concentration and physical properties measurement of silicon water using tera hertz wave

    International Nuclear Information System (INIS)

    Park, Sung Hyeon; Oh, Gyung Hwan; Kim, Hak Sung

    2017-01-01

    In this study, a tera hertz time domain spectroscopy (THz-TDS) imaging technique was used to measure doping concentration and physical properties (such as refractive index and permittivity) of the doped silicon (Si) wafers. The transmission and reflection modes with an incidence angle of 30° were employed to determine the physical properties of the doped Si wafers. The doping concentrations of the prepared Si wafers were varied from 10"1"4 to 10"1"8 in both N-type and P-type cases. Finally, the correlation between the doping concentration and the power of the THz wave was determined by measuring the powers of the transmitted and reflected THz waves of the doped Si wafers. Additionally, the doped thickness, the refractive index, and permittivity of each doped Si wafer were calculated using the THz time domain waveform. The results indicate that the THz-TDS imaging technique is potentially a promising technique to measure the doping concentration as well as other optical properties (such as the refractive index and permittivity) of the doped Si wafer

  7. Measurement of the Cupric Ion Concentration Variation near Electrodes in the Copper Electroplating System

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Je Young; Chung, Bum Jin [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    The heat fluxes to the side wall imposed at the upper metallic layer, are known to increase with the reduction of layer height. This 'Focusing effect' is varied by cooling condition of upper boundary and height of the metallic layer. The heat transfer experiments were replaced by mass transfer experiments based on the heat and mass transfer analogy concept. When the electroplating system is adopted as the mass transfer system, in order to simulate the different temperature conditions of top and side walls, an electrical resistance was attached to the top wall so that it is mimics hotter wall condition. Because the quantitative temperature conditions according to the electrical resistance were unknown, the methodology development is necessary. The electrical resistance was adopted to the top plate. But the quantitative temperature conditions depending on the electrical resistance were unknown. In order to overcome the limitations of mass transfer, this work tried to measure the cupric ion concentration. The methods of concentration measurement are RGB, Brightness, ICP, PIV, and Interferometry. The key of RGB, Brightness and PIV method is the clear images of the concentration boundary layer corresponding the thermal boundary layer of heat transfer. The results for ICP method can be got by taking the trace sample of a solution, accurately. The formation of patterns in the interferometry is very important. The characteristics of the interference pattern depend on the nature of the light source, the precise orientation of the mirrors, etc. The methodology of concentration measurement is still under development stage.

  8. The doping concentration and physical properties measurement of silicon water using tera hertz wave

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Hyeon; Oh, Gyung Hwan; Kim, Hak Sung [Dept. of Mechanical Convergence Engineering, Hanyang University, Seoul(Korea, Republic of)

    2017-02-15

    In this study, a tera hertz time domain spectroscopy (THz-TDS) imaging technique was used to measure doping concentration and physical properties (such as refractive index and permittivity) of the doped silicon (Si) wafers. The transmission and reflection modes with an incidence angle of 30° were employed to determine the physical properties of the doped Si wafers. The doping concentrations of the prepared Si wafers were varied from 10{sup 14} to 10{sup 18} in both N-type and P-type cases. Finally, the correlation between the doping concentration and the power of the THz wave was determined by measuring the powers of the transmitted and reflected THz waves of the doped Si wafers. Additionally, the doped thickness, the refractive index, and permittivity of each doped Si wafer were calculated using the THz time domain waveform. The results indicate that the THz-TDS imaging technique is potentially a promising technique to measure the doping concentration as well as other optical properties (such as the refractive index and permittivity) of the doped Si wafer.

  9. Measurement of the Cupric Ion Concentration Variation near Electrodes in the Copper Electroplating System

    International Nuclear Information System (INIS)

    Moon, Je Young; Chung, Bum Jin

    2016-01-01

    The heat fluxes to the side wall imposed at the upper metallic layer, are known to increase with the reduction of layer height. This 'Focusing effect' is varied by cooling condition of upper boundary and height of the metallic layer. The heat transfer experiments were replaced by mass transfer experiments based on the heat and mass transfer analogy concept. When the electroplating system is adopted as the mass transfer system, in order to simulate the different temperature conditions of top and side walls, an electrical resistance was attached to the top wall so that it is mimics hotter wall condition. Because the quantitative temperature conditions according to the electrical resistance were unknown, the methodology development is necessary. The electrical resistance was adopted to the top plate. But the quantitative temperature conditions depending on the electrical resistance were unknown. In order to overcome the limitations of mass transfer, this work tried to measure the cupric ion concentration. The methods of concentration measurement are RGB, Brightness, ICP, PIV, and Interferometry. The key of RGB, Brightness and PIV method is the clear images of the concentration boundary layer corresponding the thermal boundary layer of heat transfer. The results for ICP method can be got by taking the trace sample of a solution, accurately. The formation of patterns in the interferometry is very important. The characteristics of the interference pattern depend on the nature of the light source, the precise orientation of the mirrors, etc. The methodology of concentration measurement is still under development stage.

  10. Harmonisation of nanoparticle concentration measurements using GRIMM and TSI scanning mobility particle sizers

    International Nuclear Information System (INIS)

    Joshi, Manish; Sapra, B. K.; Khan, Arshad; Tripathi, S. N.; Shamjad, P. M.; Gupta, Tarun; Mayya, Y. S.

    2012-01-01

    Regional studies focusing on the role of atmospheric nanoparticles in climate change have gained impetus in the last decade. Several multi-institutional studies involving measurement of nanoparticles with several kinds of instruments are on the rise. It is important to harmonize these measurements as the instruments may work on different techniques or principles and are developed by different manufacturers. Scanning mobility particle sizers (SMPS) are often used to measure size distribution of nanoparticles in the airborne phase. Two such commercially available instruments namely, GRIMM and TSI-SMPS have been compared for ambient and laboratory generated conditions. A stand-alone condensation particle counter (CPC) of TSI make was used as a reference for particle concentration measurements. The consistency of the results in terms of mean size and geometric standard deviation was seen to be excellent for both the SMPSs, with GRIMM always showing slightly (approximately 10 %) lower mean size. The integrated number concentration from GRIMM-SMPS was seen to be closer to stand-alone reference CPC compared to TSI-SMPS, for an ambient overnight comparison. However, a concentration-dependent response, i.e. the variations between the two instruments increasing with the concentration, was observed and possible reasons for this have been suggested. A separate experiment was performed for studying the modifying effect of diffusion dryer and sheath air dryer on the measured aerosol size spectra. A significant hygroscopic growth was noted when diffusion dryer was attached to one of the SMPS. The introduction of sheath air dryer in GRIMM-SMPS produced a significant shift towards lower mean size. These results have been compared and discussed with the recent inter-comparison results to strengthen and harmonize the measurement protocols.

  11. Harmonisation of nanoparticle concentration measurements using GRIMM and TSI scanning mobility particle sizers

    Science.gov (United States)

    Joshi, Manish; Sapra, B. K.; Khan, Arshad; Tripathi, S. N.; Shamjad, P. M.; Gupta, Tarun; Mayya, Y. S.

    2012-12-01

    Regional studies focusing on the role of atmospheric nanoparticles in climate change have gained impetus in the last decade. Several multi-institutional studies involving measurement of nanoparticles with several kinds of instruments are on the rise. It is important to harmonize these measurements as the instruments may work on different techniques or principles and are developed by different manufacturers. Scanning mobility particle sizers (SMPS) are often used to measure size distribution of nanoparticles in the airborne phase. Two such commercially available instruments namely, GRIMM and TSI-SMPS have been compared for ambient and laboratory generated conditions. A stand-alone condensation particle counter (CPC) of TSI make was used as a reference for particle concentration measurements. The consistency of the results in terms of mean size and geometric standard deviation was seen to be excellent for both the SMPSs, with GRIMM always showing slightly (approximately 10 %) lower mean size. The integrated number concentration from GRIMM-SMPS was seen to be closer to stand-alone reference CPC compared to TSI-SMPS, for an ambient overnight comparison. However, a concentration-dependent response, i.e. the variations between the two instruments increasing with the concentration, was observed and possible reasons for this have been suggested. A separate experiment was performed for studying the modifying effect of diffusion dryer and sheath air dryer on the measured aerosol size spectra. A significant hygroscopic growth was noted when diffusion dryer was attached to one of the SMPS. The introduction of sheath air dryer in GRIMM-SMPS produced a significant shift towards lower mean size. These results have been compared and discussed with the recent inter-comparison results to strengthen and harmonize the measurement protocols.

  12. Specific wavelength colorimeter. [for measuring given solute concentration in test sample

    Science.gov (United States)

    Brawner, C. C.; Mcdavid, L. S.; Walsh, J. M. (Inventor)

    1974-01-01

    A self contained, specific wavelength, single beam colorimeter is described for direct spectrophotometric measurement of the concentration of a given solute in a test sample. An electrical circuit employing a photoconductive cell converts the optical output into a linear, directly readable meter output. The colorimeter is simple to operate and is adapted for use in zero gravity conditions. In a specific application, the colorimeter is designed to analyze the concentration of iodine in potable water carried aboard a space vehicle such as the 4B stage of Skylab.

  13. Analysis of predicted and measured performance of an integrated compound parabolic concentrator (ICPC)

    Energy Technology Data Exchange (ETDEWEB)

    Winston, R.; O' Gallagher, J.J.; Muschaweck, J.; Mahoney, A.R.; Dudley, V.

    1999-07-01

    A variety of configurations of evacuated Integrated Compound Parabolic Concentrator (ICPC) tubes have been under development for many years. A particularly favorable optical design corresponds to the unit concentration limit for a fin CPC solution which is then coupled to a practical, thin, wedge-shaped absorber. Prototype collector modules using tubes with two different fin orientations (horizontal and vertical) have been fabricated and tested. Comprehensive measurements of the optical characteristics of the reflector and absorber have been used together with a detailed ray trace analysis to predict the optical performance characteristics of these designs. The observed performance agrees well with the predicted performance.

  14. Measure of hydrogen concentration profile in materials by resonant nuclear reactions

    International Nuclear Information System (INIS)

    Livi, R.P.; Zawislak, F.C.; Acquadro, J.C.

    1986-01-01

    The technique for determining the profile of hydrogen concentration in proximities of the surface of materials, is presented. The preliminary measurements were done, using the Pelletron accelerator at Sao Paulo University (USP), in Brazil, for the resonant-nuclear reaction 1 H( 19 F, α γ) 16 O. By using this reaction the technique is sensitive for concentrations above 500 ppm, which could be reduced to 100 ppm through special shieldings and other techniques to reduce the background radiation. (M.C.K.) [pt

  15. Measurement of Rn-222 concentrations in building materials used in jordan

    International Nuclear Information System (INIS)

    Ismail, A.M.; Abumyrad, K.M.; Kullab, M.K.; Albataina, B.A.

    1995-01-01

    In this work, the concentrations of the radiative inert gas Rn-222 emanated from the building materials that are commonly in jordan have been studied. For this purpose, samples of ten jordanian building materials of different masses were prepared in plastic cans sealed to passive integrated dosimeters containing CR-39 solid state nuclear track detectors which are very sensitive to alpha-particles. The Rn-222 concentrations in these samples range from 137 Bq/m 3 to 267 Bq/m 3 with an average of 189 Bq/m 3 . These levels were found to be consistent with those measured by other workers in other countries. 4 figs., 2 tabs

  16. Effect of Polyether Ether Ketone on Therapeutic Radiation to the Spine: A Pilot Study.

    Science.gov (United States)

    Jackson, J Benjamin; Crimaldi, Anthony J; Peindl, Richard; Norton, H James; Anderson, William E; Patt, Joshua C

    2017-01-01

    Cadaveric model. To compare the effect of PEEK versus conventional implants on scatter radiation to a simulated tumor bed in the spine SUMMARY OF BACKGROUND DATA.: Given the highly vasculature nature of the spine, it is the most common place for bony metastases. After surgical treatment of a spinal metastasis, adjuvant radiation therapy is typically administered. Radiation dosing is primarily limited by toxicity to the spinal cord. The scatter effect caused by metallic implants decreases the accuracy of dosing and can unintentionally increase the effective dose seen by the spinal cord. This represents a dose-limiting factor for therapeutic radiation postoperatively. A cadaveric thorax specimen was utilized as a metastatic tumor model with two separate three-level spine constructs (one upper thoracic and one lower thoracic). Each construct was examined independently. All four groups compared included identical posterior instrumentation. The anterior constructs consisted of either: an anterior polyether ether ketone (PEEK) cage, an anterior titanium cage, an anterior bone cement cage (polymethyl methacrylate), or a control group with posterior instrumentation alone. Each construct had six thermoluminescent detectors to measure the radiation dose. The mean dose was similar across all constructs and locations. There was more variability in the upper thoracic spine irrespective of the construct type. The PEEK construct had a more uniform dose distribution with a standard deviation of 9.76. The standard deviation of the others constructs was 14.26 for the control group, 19.31 for the titanium cage, and 21.57 for the cement (polymethyl methacrylate) construct. The PEEK inter-body cage resulted in a significantly more uniform distribution of therapeutic radiation in the spine when compared with the other constructs. This may allow for the application of higher effective dosing to the tumor bed for spinal metastases without increasing spinal cord toxicity with either

  17. Optical measurements of atomic oxygen concentration, temperature and nitric oxide production rate in flames

    Science.gov (United States)

    Myhr, Franklin Henry

    An optical method for measuring nitric oxide (NO) production rates in flames was developed and characterized in a series of steady, one-dimensional, atmospheric-pressure laminar flames of 0.700 Hsb2/0.199 Nsb2/0.101 COsb2 or 0.700 CHsb4/0.300 Nsb2 (by moles) with dry air, with equivalence ratios from 0.79 to 1.27. Oxygen atom concentration, (O), was measured by two-photon laser-induced fluorescence (LIF), temperature was measured by ultraviolet Rayleigh scattering, and nitrogen concentration was calculated from supplied reactant flows; together this information was used to calculate the NO production rate through the thermal (Zel'dovich) mechanism. Measurements by two other techniques were compared with results from the above method. In the first comparison, gas sampling was used to measure axial NO concentration profiles, the slopes of which were multiplied by velocity to obtain total NO production rates. In the second comparison, LIF measurements of hydroxyl radical (OH) were used with equilibrium water concentrations and a partial equilibrium assumption to find (O). Nitric oxide production rates from all three methods agreed reasonably well. Photolytic interference was observed during (O) LIF measurements in all of the flames; this is the major difficulty in applying the optical technique. Photolysis of molecular oxygen in lean flames has been well documented before, but the degree of interference observed in the rich flames suggests that some other molecule is also dissociating; the candidates are OH, CO, COsb2 and Hsb2O. An extrapolative technique for removing the effects of photolysis from (O) LIF measurements worked well in all flames where NO production was significant. Using the optical method to measure NO production rates in turbulent flames will involve a tradeoff among spatial resolution, systematic photolysis error, and random shot noise. With the conventional laser system used in this work, a single pulse with a resolution of 700 mum measured NO

  18. Poly-ethers from Winogradskyella poriferorum: Antifouling potential, time-course study of production and natural abundance

    KAUST Repository

    Dash, Swagatika; Nogata, Yasuyuki; Zhou, Xiaojian; Zhang, Yifan; Xü , Ying; Guo, Xian Rong; Zhang, Xixiang; Qian, Peiyuan

    2011-01-01

    A sponge-associated bacterium, Winogradskyella poriferorum strain UST030701-295T was cultured up to 100l for extraction of antifouling bioactive compounds. Five poly-ethers were isolated and partially characterized based on nuclear magnetic

  19. Optimized measurement of radium-226 concentration in liquid samples with radon-222 emanation

    International Nuclear Information System (INIS)

    Perrier, Frédéric; Aupiais, Jean; Girault, Frédéric; Przylibski, Tadeusz A.; Bouquerel, Hélène

    2016-01-01

    Measuring radium-226 concentration in liquid samples using radon-222 emanation remains competitive with techniques such as liquid scintillation, alpha or mass spectrometry. Indeed, we show that high-precision can be obtained without air circulation, using an optimal air to liquid volume ratio and moderate heating. Cost-effective and efficient measurement of radon concentration is achieved by scintillation flasks and sufficiently long counting times for signal and background. More than 400 such measurements were performed, including 39 dilution experiments, a successful blind measurement of six reference test solutions, and more than 110 repeated measurements. Under optimal conditions, uncertainties reach 5% for an activity concentration of 100 mBq L"−"1 and 10% for 10 mBq L"−"1. While the theoretical detection limit predicted by Monte Carlo simulation is around 3 mBq L"−"1, a conservative experimental estimate is rather 5 mBq L"−"1, corresponding to 0.14 fg g"−"1. The method was applied to 47 natural waters, 51 commercial waters, and 17 wine samples, illustrating that it could be an option for liquids that cannot be easily measured by other methods. Counting of scintillation flasks can be done in remote locations in absence of electricity supply, using a solar panel. Thus, this portable method, which has demonstrated sufficient accuracy for numerous natural liquids, could be useful in geological and environmental problems, with the additional benefit that it can be applied in isolated locations and in circumstances when samples cannot be transported. - Highlights: • Radium-226 concentration measured with optimized accumulation in a container. • Radon-222 in air measured precisely with scintillation flasks and long countings. • Method tested by repetition tests, dilution experiments, and successful blind tests. • Estimated conservative detection limit without pre-concentration is 5 mBq L"−"1. • Method is portable, cost

  20. Combination scattering of dissociating gas applied to measurements of temperature and concentration of components

    International Nuclear Information System (INIS)

    Pashkov, V.A.; Kurganova, F.I.; Grishchuk, M.Kh.

    1987-01-01

    The method to calculate the combination scattering power of the components of the dissociating N 2 O 4 ↔ 2NO 2 → 2NO+O 2 gas subjected to the laser radiation effect is given. The combination scattering power has been calculated for temperatures 400-600 K, pressures 1-3 MPa, with the neodymium laser (λ=1.06 μm) as a source and the possibility of measuring the local temperatures and concentration of the given gas components with the help of the combination scattering has been analysed. It follows from the calculated data that combination scattering power of N 2 O 4 ↔ 2NO 2 ↔ 2NO+O 2 gas in excitation with the neodymium laser as a source is sufficient for detection. Gas temperature is likely to be measured with the minimum error relative to stokes and anti-stokes bands of the combination scattering, produced by nitrogen tetroxide. From calculated data it also follows that measurement of NO 2 concentration in the range 400-600 K is possible. At the same time combination scattering power, produced by NO and O 2 components is sufficient for measurement merely with the concentration of the components of the order of 10 18 molecules/cm 3 guaranteed in static conditions only at N 2 O 4 ↔ 2NO 2 ↔ 2NO+O 2 gas temperature 500 K and higher

  1. HO2 measurements at atmospheric concentrations using a chemical ionization mass spectrometry

    Science.gov (United States)

    Albrecht, S.; Novelli, A.; Hofzumahaus, A.; Kang, S.; Baker, Y.; Mentel, T. F.; Fuchs, H.

    2017-12-01

    Correct and precise measurements of atmospheric radical species are necessary for a better understanding of the oxidative capacity of the atmosphere. Due to the reactivity of radicals, and their consequent low concentrations, direct measurements of these species are particularly challenging and have been proven in the past to be affected by interfering species. Here we present a chemical ionization source coupled to an APi-HR-TOF-MS (Aerodyne Research Inc.), which has a limit of detection for HO2 radicals well below its atmospheric concentrations ( 1 x 108 molecules cm-3). The instrument was calibrated with a well-established and characterized HO2 calibration source in use for the laser induced fluorescence instrument in the Forschungszentrum Jülich. Within the source, a well characterized amount of HO2 radicals is produced after photolysis of water by a mercury lamp. In addition, several experiments were performed in the atmosphere simulation chamber SAPHIR at the Forschungszentrum Jülich to test for potential interferences. Measurements of HO2 radicals were concurrently detected by a laser induced fluorescence instrument allowing for the comparison of measurements within the two different and independent techniques for various atmospheric conditions regarding concentrations of O3, NOx and VOCs. Results from the intercomparison together with the calibration procedure of the instrument and laboratory characterization will be presented.

  2. Development of an instantaneous local fuel-concentration measurement probe: an engine application

    Science.gov (United States)

    Guibert, P.; Boutar, Z.; Lemoyne, L.

    2003-11-01

    This work presents a new tool which can deliver instantaneous local measurements of fuel concentration in an engine cylinder with a high temporal resolution, particularly during compression strokes. Fuel concentration is represented by means of equivalence fuel-air ratio, i.e. the real engine mass ratio of fuel to air divided by the same ratio in ideal stoichiometry conditions. Controlling the mixture configuration for any strategy in a spark ignition engine and for auto-ignition combustion has a dominant effect on the subsequent processes of ignition, flame propagation and auto-ignition combustion progression, pollutant formation under lean or even stoichiometric operating conditions. It is extremely difficult, under a transient operation, to control the equivalence air/fuel ratio precisely at a required value and at the right time. This requires the development of a highly accurate equivalence air/fuel ratio control system and a tool to measure using crank angle (CA) resolution. Although non-intrusive laser techniques have considerable advantages, they are most of the time inappropriate due to their optical inaccessibility or the complex experimental set-up involved. Therefore, as a response to the demand for a relatively simple fuel-concentration measurement system a probe is presented that replaces a spark plug and allows the engine to run completely normally. The probe is based on hot-wire like apparatus, but involves catalytic oxidation at the wire surface. The development, characteristics and calibration of the probe are presented followed by applications to in-cylinder engine measurements.

  3. Uncertainty propagation for the coulometric measurement of the plutonium concentration in MOX-PU4.

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2017-11-07

    This GUM WorkbenchTM propagation of uncertainty is for the coulometric measurement of the plutonium concentration in a Pu standard material (C126) supplied as individual aliquots that were prepared by mass. The C126 solution had been prepared and as aliquoted as standard material. Samples are aliquoted into glass vials and heated to dryness for distribution as dried nitrate. The individual plutonium aliquots were not separated chemically or otherwise purified prior to measurement by coulometry in the F/H Laboratory. Hydrogen peroxide was used for valence adjustment. The Pu assay measurement results were corrected for the interference from trace iron in the solution measured for assay. Aliquot mass measurements were corrected for air buoyancy. The relative atomic mass (atomic weight) of the plutonium from X126 certoficate was used. The isotopic composition was determined by thermal ionization mass spectrometry (TIMS) for comparison but not used in calculations.

  4. Uncertainty associated with the gravimetric measurement of particulate matter concentration in ambient air.

    Science.gov (United States)

    Lacey, Ronald E; Faulkner, William Brock

    2015-07-01

    This work applied a propagation of uncertainty method to typical total suspended particulate (TSP) sampling apparatus in order to estimate the overall measurement uncertainty. The objectives of this study were to estimate the uncertainty for three TSP samplers, develop an uncertainty budget, and determine the sensitivity of the total uncertainty to environmental parameters. The samplers evaluated were the TAMU High Volume TSP Sampler at a nominal volumetric flow rate of 1.42 m3 min(-1) (50 CFM), the TAMU Low Volume TSP Sampler at a nominal volumetric flow rate of 17 L min(-1) (0.6 CFM) and the EPA TSP Sampler at the nominal volumetric flow rates of 1.1 and 1.7 m3 min(-1) (39 and 60 CFM). Under nominal operating conditions the overall measurement uncertainty was found to vary from 6.1x10(-6) g m(-3) to 18.0x10(-6) g m(-3), which represented an uncertainty of 1.7% to 5.2% of the measurement. Analysis of the uncertainty budget determined that three of the instrument parameters contributed significantly to the overall uncertainty: the uncertainty in the pressure drop measurement across the orifice meter during both calibration and testing and the uncertainty of the airflow standard used during calibration of the orifice meter. Five environmental parameters occurring during field measurements were considered for their effect on overall uncertainty: ambient TSP concentration, volumetric airflow rate, ambient temperature, ambient pressure, and ambient relative humidity. Of these, only ambient TSP concentration and volumetric airflow rate were found to have a strong effect on the overall uncertainty. The technique described in this paper can be applied to other measurement systems and is especially useful where there are no methods available to generate these values empirically. This work addresses measurement uncertainty of TSP samplers used in ambient conditions. Estimation of uncertainty in gravimetric measurements is of particular interest, since as ambient particulate

  5. Measurements of CaF2 concentration in fluorite ore using thermoluminescence techniques

    International Nuclear Information System (INIS)

    Lembo, L.; Maestri, G.; Pimpinella, M.; Benzi, V.; Muntoni, C.

    1990-01-01

    Fluorite powder is produced by means of a flotation process on crude ore extracted by the mines. A full automation of the flotation plant would reduce the operating cost and improve the quality and recovery of fluorite production. However, taking into account that the efficiency of a flotation cycle is directly dependent on the CaF 2 content in the concentrate and tail products, this automation requires a quasi-real-time quantitative analysis of CaF 2 concentration in the floated pulp. The feasibility was studied of using a thermoluminescence technique as an on-line analysis method to measure the CaF 2 concentration during the flotation cycle. A first set of experimental conditions to determine CaF 2 content in acid-grade fluorspar has been already developed and the preliminary results so far obtained are presented. (author)

  6. Measurement of natural and {sup 137}Cs radioactivity concentrations at Izmit Bay (Marmara Sea), Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Öksüz, İ., E-mail: ibrahim-ksz@yahoo.com; Güray, R. T., E-mail: tguray@kocaeli.edu.tr; Özkan, N., E-mail: nozkan@kocaeli.edu.tr; Yalçin, C., E-mail: caner.yalcin@kocaeli.edu.tr [Kocaeli University, Department of Physics, Umuttepe 41380, Kocaeli (Turkey); Ergül, H. A., E-mail: halim.ergul@kocaeli.edu.tr; Aksan, S., E-mail: serdar.aksan@kocaeli.edu.tr [Kocaeli University, Department of Biology, Umuttepe 41380, Kocaeli (Turkey)

    2016-03-25

    In order to determine the radioactivity level at Izmit Bay Marmara Sea, marine sediment samples were collected from five different locations. The radioactivity concentrations of naturally occurring {sup 238}U, {sup 232}Th and {sup 40}K isotopes and also that of an artificial isotope {sup 137}Cs were measured by using gamma-ray spectroscopy. Preliminary results show that the radioactivity concentrations of {sup 238}U and {sup 232}Th isotopes are lower than the average worldwide values while the radioactivity concentrations of the {sup 40}K are higher than the average worldwide value. A small amount of {sup 137}Cs contamination, which might be caused by the Chernobyl accident, was also detected.

  7. Measurements of the radon-222 and its daughters concentrations throughout Gaza strip, Palestine

    International Nuclear Information System (INIS)

    Rasas, M.F.; Yassin, S.S.; Shabat, M.M.

    2005-01-01

    High Radon levels are present in the granite and grandiositic rocks that. spread in sand dunes along coast of Gaza. Such materials are rich in uranium and T widely used in the construction of dwelling in the Gaza, and their contribution to high indoor Radon levels is most relevant.The present work aims to investigate approaches, measures and detection of indoor Radon level throughout Gaza Strip. Five hundred CR-39 dosimeters were distributed over six locations in the middle Yv-region of Gaza Strip. Results suggest that Radon concentrations range from l3.36 to 83.82 Bq/m 3 and a maximum value of 97.01 Bq/m 3 .The average Radon concentrations was 37.83 Bq/m 3 with standard deviation of 11.23.The results provide a framework for future studies that include a large, broader survey of Radon concentration in Palestine

  8. Sedimentology models from activity concentration measurements: application to the 'Bay of Cadiz' Natural Park (SW Spain)

    International Nuclear Information System (INIS)

    Ligero, R.A.; Vidal, J.; Melendez, M.J.; Hamani, M.; Casas-Ruiz, M.

    2009-01-01

    A previous study on seabed sediments of the Bay of Cadiz (SW of Spain) enabled us to identify several relations between sedimentological variables and activity concentrations of environmental radionuclides such as 137 Cs, 226 Ra, 232 Th and 40 K. In this paper the study has been extended to a large neighbouring inter-tidal area in order to establish if the above mentioned models can be generalized. As a result we have determined that the measured activity concentrations are closely to the values predicted by the theoretical models (correlation coefficient range = 0.85-0.93). Furthermore, the proposal model for granulometric facies as a function of activity concentrations of the abovementioned radionuclides provides for the sediments distribution a representation which agrees with the values of the tidal energy distribution obtained using numeric models calibrated with experimental data from current meters and water level recorders

  9. Application of image analyzer for radon concentration measurement by nuclear track detector

    International Nuclear Information System (INIS)

    Antanasijevic, R.; Vukovic, J.; Novakovic, V.; Tasic, M.

    1998-01-01

    Radon concentration measurements were performed by determination of alpha tracks density in NTD of polymer type (Allyl diglycol polycarbonate - ADC Intercast EC, Parma). NTD plates were exposed to Rn, during 72 days in low level laboratory (LLL) at the Institute of Physics, Belgrade. Therefore, they were etched in 6N - NaOH water solution during 8 h at bath temperature of 70 0 C. The analyses of the alpha tracks was made by optical microscope and semiquantitative image analyzer using video camera digitizer attached to Pentium PC with software Ozaria V2.5. According to the determined mean track density value, ρmean=74210 tracks/cm 2 (background track density ρb=123 tracks/cm 2 ) Rn concentration was calculated to be 1174 Bq/m 3 . Obtained higher value than global - normal indoor Rn concentration might be the consequence of the temperature difference in LLL and outdoor. (author)

  10. Exposition by inhalation to the formaldehyde in the air. Source, measures and concentrations; Exposition par inhalation au formaldehyde dans l'air. Source, mesures et concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Del Gratta, F.; Durif, M.; Fagault, Y.; Zdanevitch, I

    2004-12-15

    This document presents the main techniques today available to characterize the formaldehyde concentrations in the air for different contexts: urban and rural areas or around industrial installations but also indoor and occupational area. It provides information to guide laboratories and research departments. A synthesis gives also the main emissions sources of these compounds as reference concentrations measured in different environments. (A.L.B.)

  11. Development of fast measurements of concentration of NORM U-238 by HPGe

    Science.gov (United States)

    Cha, Seokki; Kim, Siu; Kim, Geehyun

    2017-02-01

    Naturally Occureed Radioactive Material (NORM) generated from the origin of earth can be found all around us and even people who are not engaged in the work related to radiation have been exposed to unnecessary radiation. This NORM has a potential risk provided that is concentrated or transformed by artificial activities. Likewise, a development of fast measruement method of NORM is emerging to prevent the radiation exposure of the general public and person engaged in the work related to the type of business related thereto who uses the material in which NORM is concentrated or transfromed. Based on such a background, many of countries have tried to manage NORM and carried out regulatory legislation. To effienctly manage NORM, there is need for developing new measurement to quickly and accurately analyze the nuclide and concentration. In this study, development of the fast and reliable measurement was carried out. In addition to confirming the reliability of the fast measurement, we have obtained results that can suggest the possibility of developing another fast measurement. Therefore, as a follow-up, it is possible to develop another fast analytical measurement afterwards. The results of this study will be very useful for the regulatory system to manage NORM. In this study, a review of two indirect measurement methods of NORM U-238 that has used HPGe on the basis of the equilibrium theory of relationships of mother and daughter nuclide at decay-chain of NORM U-238 has been carried out. For comparative study(in order to know reliabily), direct measurement that makes use of alpha spectrometer with complicated pre-processing process was implemented.

  12. Field instruments for real time in-situ crude oil concentration measurements

    International Nuclear Information System (INIS)

    Fuller, C.B.; Bonner, J.S.; Page, C.A.; Arrambide, G.; Sterling, M.C.Jr.; Ojo, T.O.

    2003-01-01

    Accidental oil spills, contaminant release during resuspension, storms, and harmful algal blooms are all episodic events that can effect coastal margins. It is important to quantitatively describe water and ecological quality evolution and predict the impact to these areas by such events, but traditional sampling methods miss environmental activity during cyclical events. This paper presents a new sampling approach that involves continuous, real-time in-situ monitoring to provide data for development of comprehensive modeling protocols. It gives spill response coordinators greater assurance in making decisions using the latest visualization tools which are based on a good understanding of the physical processes at work in pulsed events. Five sensors for rapid monitoring of crude oil concentrations in aquatic systems were described. The in-situ and ex-situ sensors can measure plume transport and estimate polycyclic aromatic hydrocarbon exposure concentrations to assess risk of toxicity. A brief description and evaluation of the following 5 sensors was provided: the LISST-100 by Sequoia Instrument, a submersible multi-angle laser scattering instrument; the AU-10 field fluorometer by Turner Designs, an ex-situ single wavelength fluorometer; the Flashlamp by WET Labs Inc., an in-situ single wavelength fluorometer; and, the ECO-FL3 and SAFire by WET Labs Inc., two in-situ multiple wavelength fluorometers. These instruments were used to analyze crude oil emissions of various concentrations. All of the instruments followed a linear response within the tested concentration range. At the lowest concentrations the LISST-100 was not as effective as the fluorometers because of limited particle volume for scatter. For the AU-10 field fluorometer, the highest concentrations tested were above the measurement range of the instrument. 6 refs., 5 figs

  13. Concentrations and size distributions of fine aerosol particles measured at roof level in urban zone

    Science.gov (United States)

    Despiau, S.; Croci, D.

    2007-05-01

    During the experimental Field Experiments to Constrain Models of Atmospheric Pollution and Transport of Emissions (ESCOMPTE) campaign in June-July 2001, concentrations and size distributions of fine particles (14-722 nm) were measured at roof level in downtown Marseille (France). Part of the campaign was dedicated to the study of aerosol behavior in relation to strong photochemical events (which were identified as "IOP" days) and their regional modeling. The analysis of the concentration variations and the evolution of average diurnal size distribution showed that an "IOP day" is not characterized by a specific concentration or its variation, nor by a specific evolution of the average size distribution. The morning traffic rush is detected at roof level by a net increase in particle concentration over the whole size range measured, indicating a production of ultrafine particles by the traffic but also the raising to roof level of particles of the accumulation mode. The increase is observed about 1 hour after the traffic peak at street level, which is characterized by strong increases in NOx and CO concentrations. The corresponding flux of particles at roof level has been estimated around 3 × 104 cm-2 s-1. A specific signature characterized by a strong and rapid burst of concentration (factor 2 to 4 in 15 min) of particles between 25 and 50 nm, independent of the traffic source, has been detected on six occasions during the campaign. These events occur systematically around noon, in cases of strong radiation, low relative humidity, and common wind direction. Despite the high-diameter value of these particles, it is suggested that they could result from a specific "secondary aerosol process" event involving ozone, biogenic, and/or anthropogenic gas precursors like iodine and VOCs.

  14. Results of measurements of particulate matter concentrations inside a pig fattening facility

    Directory of Open Access Journals (Sweden)

    Ulens, T.

    2016-01-01

    Full Text Available Description of the subject. This research note discusses the results of measurements of particulate matter concentrations inside a pig fattening facility. Objectives. The objectives of the present study were to investigate the correlations between the different size fractions of indoor particulate matter (PM inside a pig fattening facility and to investigate the evolution of particle size distribution (PSD through a fattening period and between two housing systems and two cleaning protocols. Method. Data from two consecutive fattening periods in a commercial pig barn were used. Results. Very high correlations were found between PM10 and PM2.5 indoor concentrations. Depending on the measuring instrument, high or low correlations were found between PM1 and PM10 or PM2.5 indoor concentrations. No differences in PSD could be found between the two housing systems or the two cleaning protocols. Conclusions. The results from the present study showed high correlations between the indoor concentrations of PM10 and PM2.5. In the present study, no differences in PSD were found.

  15. Bubble growth as a means to measure dissolved nitrogen concentration in aerated water

    Science.gov (United States)

    Ando, Keita; Yamashita, Tatsuya

    2017-11-01

    Controlling the amount of dissolved gases in water is important, for example, to food processing; it is essential to quantitatively evaluate dissolved gas concentration. The concentration of dissolved oxygen (DO) can be measured by commercial DO meters, but that of dissolved nitrogen (DN) cannot be obtained easily. Here, we propose a means to measure DN concentration based on Epstein-Plesset-type analysis of bubble growth under dissolved gas supersaturation. DO supersaturation in water is produced by oxygen microbubble aeration. The diffusion-driven growth of bubbles nucleated at glass surfaces in contact with the aerated water is first observed. The observed growth is then compared to the extended Epstein-Plesset theory that considers Fick's mass transfer of both DO and DN across bubble interfaces; in this comparison, the unknown DN concentration is treated as a fitting parameter. Comparisons between the experiment and the theory suggest, as expected, that DN can be effectively purged by oxygen microbubble aeration. This study was supported in part by the Mizuho Foundation for the Promotion of Science and by a MEXT Grant-in-Aid for the Program for Leading Graduate Schools.

  16. Measurement and analysis of the concentration and size distribution of aerosols in a copper mine

    International Nuclear Information System (INIS)

    Li Dehong; Zhuo Weihai; Huang Gang; Su Xu; Sun Quanfu

    2008-01-01

    Objective: To explore the general characteristics of the concentration and size distribution of aerosols in a mine. Methods: In different areas of a non-uranium mine, the particle number and mass concentration of aerosols were surveyed with a condensation particle counter and a personal aerosol monitor, respectively, and the size distribution of aerosols larger than 1 μm in size was estimated according to the size- selective measurements of mass concentrations. The size distribution of submicron aerosols was evaluated based on the method of screen diffusion battery (SOB), and the measurements were performed in both inside and outside of a control room. Results: The mass concentration of inhaled particles (PM10) was averaged to be 0.42 mg/m 3 in the whole mine, and it varied with different working areas and significantly affected with human activities. In the mine, particles lager than 1 μm in size widely distributed, while the particles less than 5 nm in size were seldom observed. Conclusions: The characteristics of aerosol significantly change with different working areas, human activities and Antilation condition in mine. The dose contribution from inhaled radioactive particles larger than 1 μm in size should be considered in mine. (authors)

  17. Uncertainties of retrospective radon concentration measurements by multilayer surface trap detector

    International Nuclear Information System (INIS)

    Bastrikov, V.; Kruzhalov, A.; Zhukovsky, M.

    2006-01-01

    The detector for retrospective radon exposure measurements is developed. The detector consists of the multilayer package of solid-state nuclear track detectors LR-115 type. Nitrocellulose films works both as α-particle detector and as absorber decreasing the energy of α-particles. The uncertainties of implanted 210 Pb measurements by two- and three-layer detectors are assessed in dependence on surface 210 Po activity and gross background activity of the glass. The generalized compartment behavior model of radon decay products in the room atmosphere was developed and verified. It is shown that the most influencing parameters on the value of conversion coefficient from 210 Po surface activity to average radon concentration are aerosol particles concentration, deposition velocity of unattached 218 Po and air exchange rate. It is demonstrated that with the use of additional information on surface to volume room ratio, air exchange rate and aerosol particles concentration the systematic bias of conversion coefficient between surface activity of 210 Po and average radon concentration can be decreased up to 30 %. (N.C.)

  18. In situ measurements of hydrogen concentration and flux between 160 and 300 km in the thermosphere

    International Nuclear Information System (INIS)

    Breig, E.L.; Hanson, W.B.; Hoffman, J.H.; Kayser, D.C.

    1976-01-01

    Thermospheric concentrations of neutral atomic hydrogen near and below the F peak are directly related to H + , O + and atomic oxygen concentrations through the charge exchange equilibrium that is established between hydrogen and oxygen at these altitudes. This chemical relationship, together with in situ measurements of ionospheric and neutral atmospheric concentrations by instrumentation on board the Atmosphere Explorer C satellite, is utilized to investigate properties of neutral hydrogen at altitudes below 200 km where vertical diffusion strongly affects the hydrogen distribution. Data are discussed for a set of satellite orbits during quiet geomagnetic and solar conditions in February 1974; the resultant altitude variation of the derived hydrogen concentrations applies specifically to early afternoon at low 10 5 atoms/cm 3 is observed for these conditions at 300 km. At lower altitudes the concentration profiles are interpreted in terms of vertical hydrogen flow. The resultant daytime flux in the thermosphere is estimated to be (3.2 +- 1.0) x 10 8 atoms/cm 2 s. The present observations thus support theoretical estimates and model calculations of large hydrogen flow upward from the region below 100 km. They also support the concept of daytime thermospheric loss process of greater magnitude than the traditional evaporative escape mechanism

  19. Measurement of trimethylamine concentration and evaluation of pig meat natural quality by a spectrophotometric method

    Directory of Open Access Journals (Sweden)

    Mohammod Abdul HAMID,Xi WANG,Xiangdong DING,Chuduan WANG,Xingbo ZHAO

    2014-09-01

    Full Text Available Pig meat off-flavor is attributed to trimethylamine (TMA concentration, and it is considered as the precursor of the fishy off-flavor problems. In this study, TMA concentrations in pig meat were determined, and the interactions with breed and gender effects were discussed. In addition, the TMA threshold for meat off-flavor and pig meat natural quality was measured in relation to meat storage and movement, and the influential factors including the pig breed and storage time were discussed. The results indicated positive effects on the precursor of the fishy off-flavor and the TMA threshold. Native breeds were found to have lower TMA concentrations than European breeds (P<0.01, and females and castrated males had significantly lower TMA concentration than males (P<0.01, The threshold concentration of TMA when meat was classed as off-flavored was 25 μg·g-1, and this occurred after 35–38 h of storage. The natural qualities, such as appearance, flavor, color and overall acceptable scores declined significantly after 4 days in storage (P<0.01. It is concluded that pig meat off-flavor, breed and gender were essential factors affecting flavor for meat breeding programs, and storage time is important for pig meat natural quality.

  20. Measurement of fluorescent probes concentration ratio in the cerebrospinal fluid for early detection of Alzheimer's disease

    Science.gov (United States)

    Harbater, Osnat; Gannot, Israel

    2014-03-01

    The pathogenic process of Alzheimer's Disease (AD), characterized by amyloid plaques and neurofibrillary tangles in the brain, begins years before the clinical diagnosis. Here, we suggest a novel method which may detect AD up to nine years earlier than current exams, minimally invasive, with minimal risk, pain and side effects. The method is based on previous reports which relate the concentrations of biomarkers in the Cerebrospinal Fluid (CSF) (Aβ and Tau proteins) to the future development of AD in mild cognitive impairment patients. Our method, which uses fluorescence measurements of the relative concentrations of the CSF biomarkers, replaces the lumbar puncture process required for CSF drawing. The process uses a miniature needle coupled trough an optical fiber to a laser source and a detector. The laser radiation excites fluorescent probes which were prior injected and bond to the CSF biomarkers. Using the ratio between the fluorescence intensities emitted from the two biomarkers, which is correlated to their concentration ratio, the patient's risk of developing AD is estimated. A theoretical model was developed and validated using Monte Carlo simulations, demonstrating the relation between fluorescence emission and biomarker concentration. The method was tested using multi-layered tissue phantoms simulating the epidural fat, the CSF in the sub-arachnoid space and the bone. These phantoms were prepared with different scattering and absorption coefficients, thicknesses and fluorescence concentrations in order to simulate variations in human anatomy and in the needle location. The theoretical and in-vitro results are compared and the method's accuracy is discussed.

  1. Estimating the relation between groundwater and river water by measuring the concentration of Rn-222

    Energy Technology Data Exchange (ETDEWEB)

    Yoneda, Minoru; Morisawa, Shinsuke [Kyoto Univ. (Japan). Faculty of Engineering

    1997-02-01

    This study aimed to estimate the relationship between groundwater in shallow layer and river water by determining the concentrations of {sup 222}Rn and nitric nitrogen along with water temperature. The region around ca. 20 km along river A in a certain basin was chosen as a test area. The Rn concentration of groundwater was determined by Rn extracting with toluene and counting in liquid scintillation counter, whereas for river water, it was determined by activated charcoal passive collector method developed by the authors, by which the amount of Rn adsorbed on activated charcoal was estimated by Ge-solid state detector. In addition, water temperature and nitric nitrogen concentration were measured at various points in the test area. Thus, a distribution map of the three parameters was made on the basis of the data obtained in December, 1989. Since Rn concentration is generally higher in ground water than river water and the water temperature in December is higher in the former, it seems likely that the concentrations of Rn and nitric nitrogen would become higher in the area where ground water soaks into river water. Thus, the directions of ground water flow at the respective sites along river A were estimated from the data regarding the properties of ground water. (M.N.)

  2. Subaru Weak Lensing Measurements of Four Strong Lensing Clusters: Are Lensing Clusters Over-Concentrated?

    Energy Technology Data Exchange (ETDEWEB)

    Oguri, Masamune; Hennawi, Joseph F.; Gladders, Michael D.; Dahle, Haakon; Natarajan, Priyamvada; Dalal, Neal; Koester, Benjamin P.; Sharon, Keren; Bayliss, Matthew

    2009-01-29

    We derive radial mass profiles of four strong lensing selected clusters which show prominent giant arcs (Abell 1703, SDSS J1446+3032, SDSS J1531+3414, and SDSS J2111-0115), by combining detailed strong lens modeling with weak lensing shear measured from deep Subaru Suprime-cam images. Weak lensing signals are detected at high significance for all four clusters, whose redshifts range from z = 0.28 to 0.64. We demonstrate that adding strong lensing information with known arc redshifts significantly improves constraints on the mass density profile, compared to those obtained from weak lensing alone. While the mass profiles are well fitted by the universal form predicted in N-body simulations of the {Lambda}-dominated cold dark matter model, all four clusters appear to be slightly more centrally concentrated (the concentration parameters c{sub vir} {approx} 8) than theoretical predictions, even after accounting for the bias toward higher concentrations inherent in lensing selected samples. Our results are consistent with previous studies which similarly detected a concentration excess, and increases the total number of clusters studied with the combined strong and weak lensing technique to ten. Combining our sample with previous work, we find that clusters with larger Einstein radii are more anomalously concentrated. We also present a detailed model of the lensing cluster Abell 1703 with constraints from multiple image families, and find the dark matter inner density profile to be cuspy with the slope consistent with -1, in agreement with expectations.

  3. Measurement of cytoplasmic Ca2+ concentration in Saccharomyces cerevisiae induced by air cold plasma

    Science.gov (United States)

    Xiaoyu, DONG

    2018-03-01

    In this study, a novel approach to measure the absolute cytoplasmic Ca2+ concentration ([Ca2+]cyt) using the Ca2+ indicator fluo-3 AM was established. The parameters associated with the probe fluo-3 AM were optimized to accurately determine fluorescence intensity from the Ca2+-bound probe. Using three optimized parameters (final concentration of 6 mM probe, incubation time of 135 min, loading probe before plasma treatment), the maximum fluorescence intensity (F max = 527.8 a.u.) and the minimum fluorescence intensity (F min = 63.8 a.u.) were obtained in a saturated Ca2+ solution or a solution of lacking Ca2+. Correspondingly, the maximum [Ca2+]cyt induced by cold plasma was 1232.5 nM. Therefore, the Ca2+ indicator fluo-3 AM was successfully applied to measure the absolute [Ca2+]cyt in Saccharomyces cerevisiae stimulated by cold plasma at atmospheric air pressure.

  4. Field calibration of optical sensors for measuring suspended sediment concentration in the western Mediterranean

    Directory of Open Access Journals (Sweden)

    J. Guillén

    2000-12-01

    Full Text Available The water turbidity measured with optical methods (transmittance and backscattering is usually expressed as beam attenuation coefficient (BAC or formazin turbidity units (FTU. The transformation of these units to volumetric suspended sediment concentration (SSC units is not straightforward, and accurate calibrations are required in order to obtain valuable information on suspended sediment distributions and fluxes. In this paper, data from field calibrations between BAC, FTU and SSC are presented and best-fit calibration curves are shown. These calibrations represent an average from different marine environments of the western Mediterranean (from estuary to continental slope. However, the general curves can only be applied for descriptive or semi-quantitative purposes. Comparison of turbidity measurements using the same sensor with different calibration ranges shows the advantage of simultaneously combining two instruments calibrated in different ranges when significant changes in suspended sediment concentrations are expected.

  5. Size, velocity, and concentration in suspension measurements of spherical droplets and cylindrical jets.

    Science.gov (United States)

    Onofri, F; Bergougnoux, L; Firpo, J L; Misguich-Ripault, J

    1999-07-20

    The principle of an optical technique for simultaneous velocity, size, and concentration in suspension measurements of spherical droplets and cylindrical jets is proposed. This technique is based on phase Doppler anemometry working in the dual burst technique configuration. The particle size and velocity are deduced from the reflected signal phase and frequency, whereas the amplitude ratio between the refracted and the reflected signals is used for measuring the concentration of small scatterers inside the particles. Numerical simulations, based on geometrical optics and a Monte Carlo model, and an experimental validation test on cylindrical jets made of various suspensions, are used to validate the principle of the proposed technique. It is believed that this new technique could be useful in investigating processes in which liquid suspensions are sprayed for surface coating, drying, or combustion applications.

  6. Variation of molecular hydrogen tropospheric concentration over Southern Poland - results of the continuous chromatographic measurements.

    Science.gov (United States)

    Necki, J.; Chmura, L.

    2012-04-01

    Although hydrogen is one of the fundamental constituents of the earth's atmosphere its global balance is still poorly clarified. A few developed inventories diverging values for efficiency of sources and sinks of this gas. The European network for the hydrogen concentrations measurement is based on several unevenly spaced measurement points. While in 2009 MPI Jena has delivered accurate scale for hydrogen measurements and the techniques of analyses are well described, still large areas of Central Europe is uncovered by representative stations. The first measurement point, established under the EUROHYDROS EU program, on the territory of Poland was Kraków city. Different laboratory setups was tested there and compared to each other. The Kraków area has significant car traffic and its geographical location implies frequent temperature inversions in lower troposphere leading to the accumulation of trace gases in atmosphere of the city. Observations launched in 2007 revealed that the concentration of hydrogen fluctuates strongly within diurnal and seasonal timescales. Its average concentration is three times larger than this, observed at the other stations. The European "background" concentrations of hydrogen are not reflected in the Krakow record. An ideal place to carry out observation of the regional air composition for Central Europe is a research station located in the meteorological observatory at Kasprowy Wierch. Measurement point at the top of mountain peak with elevation of 2000m a.s.l. gives an access to the well mixed troposphere. The station delivers also the necessary facilities and logistics. Since year 1996 greenhouse gas measurement program has been operating at this point. The first measurements of atmospheric concentrations of hydrogen at Kasprowy Wierch were performed in year 2010, based on dedicated gas chromatograph using RGD detector installed at the station. Analysis of hydrogen content in the outside air is performed without any enrichment

  7. A Florescence Detection Module for Photodynamic Therapy Optimization by Measuring the Concentration of Photo sensitizer

    International Nuclear Information System (INIS)

    Serrano Navarro, Joel; Stolik Isakina, Suren; La Rosa Vazquez, Jose M. de; Valor Reed, Alma

    2016-01-01

    In the present work, a portable fluorescence detection system designed and built for dosimetry control applications in Photodynamic Therapy is presented. The system excites the used photo sensitizer drug with a modulated laser light source and subsequently measures the radiance of the emitted fluorescent light. Since the fluorescent radiance is directly related to the photosensitizers concentration, this measurement allows for real-time monitoring of the photo sensitizer concentration in the treated tissue. The system is thought to permit adjusting the therapeutic regime in order to optimize the expected therapy results. In the developed system, a synchronous detection technique is employed to recover the fluorescence signals embedded in noisy backgrounds and lit environments. A scanning probe with a 405 nm diode laser is used to excite the photo sensitizer, while a detection wavelength range from 590 nm to 700 nm has been implemented. (Author)

  8. Hydrogen peroxide and glucose concentration measurement using optical fiber grating sensors with corrodible plasmonic nanocoatings.

    Science.gov (United States)

    Zhang, Xuejun; Wu, Ze; Liu, Fu; Fu, Qiangqiang; Chen, Xiaoyong; Xu, Jian; Zhang, Zhaochuan; Huang, Yunyun; Tang, Yong; Guo, Tuan; Albert, Jacques

    2018-04-01

    We propose and demonstrate hydrogen peroxide (H 2 O 2 ) and glucose concentration measurements using a plasmonic optical fiber sensor. The sensor utilizes a tilted fiber Bragg grating (TFBG) written in standard single mode communication fiber. The fiber is over coated with an nm-scale film of silver that supports surface plasmon resonances (SPRs). Such a tilted grating SPR structure provides a high density of narrow spectral resonances (Q-factor about 10 5 ) that overlap with the broader absorption band of the surface plasmon waves in the silver film, thereby providing an accurate tool to measure small shifts of the plasmon resonance frequencies. The H 2 O 2 to be detected acts as an oxidant to etch the silver film, which has the effect of gradually decreasing the SPR attenuation. The etching rate of the silver film shows a clear relationship with the H 2 O 2 concentration so that monitoring the progressively increasing attenuation of a selected surface plasmon resonance over a few minutes enables us to measure the H 2 O 2 concentration with a limit of detection of 0.2 μM. Furthermore, the proposed method can be applied to the determination of glucose in human serum for a concentration range from 0 to 12 mM (within the physiological range of 3-8 mM) by monitoring the H 2 O 2 produced by an enzymatic oxidation process. The sensor does not require accurate temperature control because of the inherent temperature insensitivity of TFBG devices referenced to the core mode resonance. A gold mirror coated on the fiber allows the sensor to work in reflection, which will facilitate the integration of the sensor with a hypodermic needle for in vitro measurements. The present study shows that Ag-coated TFBG-SPR can be applied as a promising type of sensing probe for optical detection of H 2 O 2 and glucose detection in human serum.

  9. Measuring low radium activity concentration in water with RAD7 by means of evaporation

    International Nuclear Information System (INIS)

    Kappke, Jaqueline; Marussig, Camila G.T.; Paschuk, Sergei; Zambianchi Junior, Pedro; Correa, Janine N.; Perna, Allan Felipe Nunes; Martin, Aline

    2015-01-01

    Preliminary activity measurements of low radium concentration in mineral water by using RAD7 equipment showed high values of statistical errors. Therefore, the need to develop a new protocol for measuring and proofing the evaporation test for radium measurements in water is in place. This study evaluates the possibility of using RAD7 equipment to measure Ra-226 activity in equilibrium with Rn-222 present in water samples. The technique involves evaporation process so as to increase the Ra-226 concentration in the sample in a controlled manner and thus reduce statistical errors. Two samples were compared, 10 L sample of distilled water and a 7.75 L sample of known concentration (0.1 Bq/L). The evaporation was carried out starting with different initial volumes for both samples: 500 mL, 1000 mL, 2000 mL, 4000 mL and a 250 mL sample not subject to evaporation. All samples reached a final volume of approximately 250 mL. After evaporation, the samples were stored for 30 days until secular equilibrium was achieved between Ra-226 and Rn-222. The values obtained, by using RAD7 detector, for distilled water, as expected, are near zero averaging 0.021 ± 0.016 Bq/L. The average value found in the water of known concentration was 0.099 ± 0.011 Bq/L, also close to the expected 0.1 Bq/L. The conclusion is that the application of an evaporation process is efficient and the proposed methodology is a proven alternative to decrease the statistical errors. (author)

  10. Measuring gas concentration and wind intensity in a turbulent wind tunnel with a mobile robot

    OpenAIRE

    Martínez Lacasa, Daniel; Moreno Blanc, Javier; Tresánchez, Marcel; Clotet Bellmunt, Eduard; Jiménez-Soto, Juan M.; Magrans, Rudys; Pardo Martínez, Antonio; Marco Colás, Santiago; Palacín Roca, Jordi

    2016-01-01

    This paper presents themeasurement of gas concentration and wind intensity performed with amobile robot in a customturbulent wind tunnel designed for experimentation with customizable wind and gas leak sources.This paper presents the representation in different information layers of the measurements obtained in the turbulent wind tunnel under different controlled environmental conditions in order to describe the plume of the gas and wind intensities inside the experimentation chamber...

  11. Measurement of the concentration of plasmatic cortisol by competition to the binding protein

    International Nuclear Information System (INIS)

    Okada, H.; Tambascia, M.A.; Wajchenberg, B.L.; Pieroni, R.R.

    1977-01-01

    The concentration of plasmatic cortisol was measured by competition to the binding protein (transcortin), after extracting the samples with dicloromethane. It is a suitable method for clinical routine, 100μl of plasma being used in each analysis. The normal mean +- standard error mean in 8:00 a.m. fasting subjects was 13,62 +- 5,43 μl/100 ml of plasma [pt

  12. Hydrogen peroxide and glucose concentration measurement using optical fiber grating sensors with corrodible plasmonic nanocoatings

    Science.gov (United States)

    Zhang, Xuejun; Wu, Ze; Liu, Fu; Fu, Qiangqiang; Chen, Xiaoyong; Xu, Jian; Zhang, Zhaochuan; Huang, Yunyun; Tang, Yong; Guo, Tuan; Albert, Jacques

    2018-01-01

    We propose and demonstrate hydrogen peroxide (H2O2) and glucose concentration measurements using a plasmonic optical fiber sensor. The sensor utilizes a tilted fiber Bragg grating (TFBG) written in standard single mode communication fiber. The fiber is over coated with an nm-scale film of silver that supports surface plasmon resonances (SPRs). Such a tilted grating SPR structure provides a high density of narrow spectral resonances (Q-factor about 105) that overlap with the broader absorption band of the surface plasmon waves in the silver film, thereby providing an accurate tool to measure small shifts of the plasmon resonance frequencies. The H2O2 to be detected acts as an oxidant to etch the silver film, which has the effect of gradually decreasing the SPR attenuation. The etching rate of the silver film shows a clear relationship with the H2O2 concentration so that monitoring the progressively increasing attenuation of a selected surface plasmon resonance over a few minutes enables us to measure the H2O2 concentration with a limit of detection of 0.2 μM. Furthermore, the proposed method can be applied to the determination of glucose in human serum for a concentration range from 0 to 12 mM (within the physiological range of 3-8 mM) by monitoring the H2O2 produced by an enzymatic oxidation process. The sensor does not require accurate temperature control because of the inherent temperature insensitivity of TFBG devices referenced to the core mode resonance. A gold mirror coated on the fiber allows the sensor to work in reflection, which will facilitate the integration of the sensor with a hypodermic needle for in vitro measurements. The present study shows that Ag-coated TFBG-SPR can be applied as a promising type of sensing probe for optical detection of H2O2 and glucose detection in human serum. PMID:29675315

  13. Ultrasonic device for real-time sewage velocity and suspended particles concentration measurements.

    Science.gov (United States)

    Abda, F; Azbaid, A; Ensminger, D; Fischer, S; François, P; Schmitt, P; Pallarès, A

    2009-01-01

    In the frame of a technological research and innovation network in water and environment technologies (RITEAU, Réseau de Recherche et d'Innovation Technologique Eau et Environnement), our research group, in collaboration with industrial partners and other research institutions, has been in charge of the development of a suitable flowmeter: an ultrasonic device measuring simultaneously the water flow and the concentration of size classes of suspended particles. Working on the pulsed ultrasound principle, our multi-frequency device (1 to 14 MHz) allows flow velocity and water height measurement and estimation of suspended solids concentration. Velocity measurements rely on the coherent Doppler principle. A self developed frequency estimator, so called Spectral Identification method, was used and compared to the classical Pulse-Pair method. Several measurements campaigns on one wastewater collector of the French city of Strasbourg gave very satisfactory results and showed smaller standard deviation values for the Doppler frequency extracted by the Spectral Identification method. A specific algorithm was also developed for the water height measurements. It relies on the water surface acoustic impedance rupture and its peak localisation and behaviour in the collected backscattering data. This algorithm was positively tested on long time measurements on the same wastewater collector. A large part of the article is devoted to the measurements of the suspended solids concentrations. Our data analysis consists in the adaptation of the well described acoustic behaviour of sand to the behaviour of wastewater particles. Both acoustic attenuation and acoustic backscattering data over multiple frequencies are analyzed for the extrapolation of size classes and respective concentrations. Under dry weather conditions, the massic backscattering coefficient and the overall size distribution showed similar evolution whatever the measurement site was and were suggesting a global

  14. Estimation of natural potassium concentration in Romanian males by in vivo gamma-ray spectrometry measurements

    International Nuclear Information System (INIS)

    Mirela Angela Saizu

    2012-01-01

    At the Whole Body Monitoring Laboratory, from IFIN-HH, Bucharest, Romania, there were performed in vivo gamma-ray spectrometry measurements on 108 Romanian males in order to evaluate the mineral natural potassium content in human body, as total value and concentration. The measurements were performed with a shadow shield whole body counter, tilted chair geometry, based on a shielded NaI(Tl) scintillation detector of 12.5 cm (diameter) x 10 cm (height) crystal size. The results revealed a calculated value of the mean total body potassium (TBK) of 135.03 ± 2.94 g and a value of 1.9 ± 0.022 g of potassium/kg of body weight for the mean body potassium concentration, for the measured males. These values are similar with the values declared for the Reference Man, in ICRP23. Correlations between total body potassium, potassium concentration and age, weight and Body Build Index were investigated and peculiar conclusions were resulted. (author)

  15. Concentrations and flux measurements of volatile organic compounds (VOC) in boreal forest soil

    Science.gov (United States)

    Mäki, Mari; Aaltonen, Hermanni; Heinonsalo, Jussi; Hellén, Heidi; Pumpanen, Jukka; Bäck, Jaana

    2017-04-01

    Volatile organic compounds (VOC) impact soil processes as VOCs transmit signals between roots and rhizosphere (Ditengou et al., 2015), VOCs can regulate microbial activity (Asensio et al., 2012), and VOCs can also promote root growth (Hung et al., 2012). Belowground concentrations of VOCs have not been measured in situ and for this reason, knowledge of how different soil organisms such as roots, rhizosphere and decomposers contribute to VOC production is limited. The aim of this study was to determine and quantify VOC fluxes and concentrations of different horizons from boreal forest soil. The VOC concentrations and fluxes were measured from Scots pine (Pinus sylvestris) forest soil at the SMEAR II station in southern Finland from 21th of April to 2nd of December in 2016. VOC fluxes were measured using dynamic (flow-through) chambers from five soil collars placed on five different locations. VOC concentrations were also measured in each location from four different soil horizons with the measurement depth 1-107 cm. VOCs were collected from underground gas collectors into the Tenax-Carbopack-B adsorbent tubes using portable pumps ( 100 ml min-1). The VOC concentrations and fluxes of isoprene, 11 monoterpenes, 13 sesquiterpenes and different oxygenated VOCs were measured. Sample tubes were analyzed using thermal desorption-gas chromatograph-mass spectrometry (TD-GC-MS). Soil temperature and soil water content were continuously monitored for each soil horizon. Our preliminary results show that the primary source of VOCs is organic soil layer and the contribution of mineral soil to the VOC formation is minor. VOC fluxes and concentrations were dominated by monoterpenes such as α-pinene, camphene, β-pinene, and Δ3-carene. Monoterpene concentration is almost 10-fold in organic soil compared to the deeper soil layers. However, the highest VOC fluxes on the soil surface were measured in October, whereas the monoterpene concentrations in organic soil were highest in July

  16. Real-time measurements of suspended sediment concentration and particle size using five techniques

    Science.gov (United States)

    Felix, D.; Albayrak, I.; Abgottspon, A.; Boes, R. M.

    2016-11-01

    Fine sediments are important in the design and operation of hydropower plants (HPPs), in particular with respect to sediment management and hydro-abrasive erosion in hydraulic machines. Therefore, there is a need for reliable real-time measurements of suspended sediment mass concentration (SSC) and particle size distribution (PSD). The following instruments for SSC measurements were investigated in a field study during several years at the HPP Fieschertal in the Swiss Alps: (1) turbidimeters, (2) a Laser In-Situ Scattering and Trans- missometry instrument (LISST), (3) a Coriolis Flow and Density Meter (CFDM), (4) acoustic transducers, and (5) pressure sensors. LISST provided PSDs in addition to concentrations. Reference SSCs were obtained by gravimetrical analysis of automatically taken water samples. In contrast to widely used turbidimeters and the single-frequency acoustic method, SSCs obtained from LISST, the CFDM or the pressure sensors were less or not affected by particle size variations. The CFDM and the pressure sensors allowed measuring higher SSC than the optical or the acoustic techniques (without dilution). The CFDM and the pressure sensors were found to be suitable to measure SSC ≥ 2 g/l. In this paper, the measuring techniques, instruments, setup, methods for data treatment, and selected results are presented and discussed.

  17. Toward new instruments for measurement of low concentration hydrogen sulfide in small-quantity aqueous solutions

    International Nuclear Information System (INIS)

    Wu, Xiao Chu; Wu, Dong Qing; Zhang, W J; Sammynaiken, R; Yang, Wei; Wang, Rui

    2008-01-01

    Endogenously generated hydrogen sulfide (H 2 S) has been found to play some important physiological roles in the nervous and cardiovascular systems, such as a neuromodulator and a vasorelaxant. These roles are in contrast to our common perception that H 2 S is toxic. However, whether H 2 S plays a positive or negative role is dependent on the H 2 S concentration levels in mammals. This further puts a high demand on the accurate measurement of H 2 S in mammals with a further desire to be real time, continuous and in vivo. Existing methods for H 2 S measurement require a large number of tissue samples with complex procedures, and these methods are extremely invasive. The development of new in vivo and real-time methods for measuring H 2 S is, however, a great challenge. In the present study, we proposed and examined five potential H 2 S measurement methods: (1) atomic force microscopy with coating materials, (2) Raman spectroscopy on the H 2 S solutions, (3) gas chromatography/mass spectroscopy (with the static headspace technique) on the H 2 S solutions, (4) mass spectroscopy on unfunctionalized carbon nanotubes treated with the H 2 S solutions and (5) Raman spectroscopy on unfunctionalized carbon nanotubes treated with the H 2 S solutions. Our study concluded that method (5) is the most promising one for detecting low concentration H 2 S in small-quantity aqueous solutions in terms of measurement resolution and non-invasiveness, but the method is not very robust

  18. The estimation of heavy metal concentration in FBR reprocessing solvent streams by density measurement

    International Nuclear Information System (INIS)

    Brown, M.L.; Savage, D.J.

    1986-04-01

    The application of density measurement to heavy metal monitoring in the solvent phase is described, including practical experience gained during three fast reactor fuel reprocessing campaigns. An experimental algorithm relating heavy metal concentration and sample density was generated from laboratory-measured density data, for uranyl nitrate dissolved in nitric acid loaded tri-butyl phosphate in odourless kerosene. Differences in odourless kerosene batch densities are mathematically interpolated, and the algorithm can be used to estimate heavy metal concentrations from the density to within +1.5 g/l. An Anton Paar calculating digital densimeter with remote cell operation was used for all density measurements, but the algorithm will give similar accuracy with any density measuring device capable of a precision of better than 0.0005 g/cm 3 . For plant control purposes, the algorithm was simplified using a density referencing system, whereby the density of solvent not yet loaded with heavy metal is subtracted from the sample density. This simplified algorithm compares very favourably with empirical algorithms, derived from numerical analysis of density data and chemically measured uranium and plutonium data obtained during fuel reprocessing campaigns, particularly when differences in the acidity of the solvent are considered before and after loading with heavy metal. This simplified algorithm had been successfully used for plant control of heavy metal loaded solvent during four fast reactor fuel reprocessing campaigns. (author)

  19. Absorption infrared spectra of interaction products of cyclic polyethers 18-crown-6 and dibenzo-18-crown-6 with uranyl dinitrate hexahydrate

    International Nuclear Information System (INIS)

    Chumaevskij, N.A.; Belomestnykh, V.I.; Razgonyaeva, G.A.; Shabel'nik, K.S.; Afanas'eva, E.E.

    1988-01-01

    Using the method of IR spectroscopy it is established that during interaction of uranyl nitrate hexahydrate (UNH) with crown-ethers under investigation macrocycles adhere to UO 2 2+ via hydrogen bonds between water molecules and oxygen of polyethers. Interaction of UNH with the above-mentioned crowns leads to conformational rearrangement of cycles of polyethers and improvement of their symmetry, reflecting in noticeable simplification of IR spectra of interaction products as compared to spectra of initial cyclic polyethers

  20. A novel method of measuring the concentration of anaesthetic vapours using a dew-point hygrometer.

    Science.gov (United States)

    Wilkes, A R; Mapleson, W W; Mecklenburgh, J S

    1994-02-01

    The Antoine equation relates the saturated vapour pressure of a volatile substance, such as an anaesthetic agent, to the temperature. The measurement of the 'dew-point' of a dry gas mixture containing a volatile anaesthetic agent by a dew-point hygrometer permits the determination of the partial pressure of the anaesthetic agent. The accuracy of this technique is limited only by the accuracy of the Antoine coefficients and of the temperature measurement. Comparing measurements by the dew-point method with measurements by refractometry showed systematic discrepancies up to 0.2% and random discrepancies with SDS up to 0.07% concentration in the 1% to 5% range for three volatile anaesthetics. The systematic discrepancies may be due to errors in available data for the vapour pressures and/or the refractive indices of the anaesthetics.

  1. Water temperature and concentration measurements within the expanding blast wave of a high explosive

    International Nuclear Information System (INIS)

    Carney, J R; Lightstone, J M; Piecuch, S; Koch, J D

    2011-01-01

    We present an application of absorption spectroscopy to directly measure temperature and concentration histories of water vapor within the expansion of a high explosive detonation. While the approach of absorption spectroscopy is well established, the combination of a fast, near-infrared array, broadband light source, and rigid gauge allow the first application of time-resolved absorption measurements in an explosive environment. The instrument is demonstrated using pentaerythritol tetranitrate with a sampling rate of 20 kHz for 20 ms following detonation. Absorption by water vapor is measured between 1335 and 1380 nm. Water temperatures are determined by fitting experimental transmission spectra to a simulated database. Water mole fractions are deduced following the temperature assignment. The sources of uncertainty and their impact on the results are discussed. These measurements will aid the development of chemical-specific reaction models and the predictive capability in technical fields including combustion and detonation science

  2. Measurements of ice nucleating particle concentrations at 242 K in the free troposphere

    Science.gov (United States)

    Lacher, L.; Lohmann, U.; Boose, Y.; Zipori, A.; Herrmann, E.; Bukowiecki, N.; Steinbacher, M.; Gute, E.; Kanji, Z. A.

    2017-12-01

    Clouds containing ice play an important role in the Earth's system, but some fundamental knowledge on their formation and further development is still missing. The phase change from vapor or liquid to ice in the atmosphere can occur heterogeneously in the presence of ice nucleating particles (INPs) at temperatures warmer, and supersaturations lower than required for homogeneous freezing. Only a small fraction of particles in an environment relevant for the occurrence of ice- and mixed-phase clouds are INPs, and their identification and quantification remains challenging. We measure INP concentrations with the ETH Horizontal Ice Nucleation Chamber (HINC) at the High Altitude Research Station Jungfraujoch (JFJ) during several field campaigns in different seasons and years. The measurements are performed at 242 K and above water saturation, representing ice- and mixed-phase clouds conditions. Due to its elevation of 3580 m a.s.l. the site encounters mostly free tropospheric conditions, and is influenced by boundary layer injections up to 80% of the time in summer. JFJ regularly encounters Saharan dust events and receives air masses of marine origin, which can both occur within the free troposphere. Our measurements show that INP concentrations in the free troposphere do not follow a seasonal cycle. They are remarkably constant, with concentrations from 0.5 - 8 L-1 (interquartile range), which compares well to measurements performed under the same conditions at another location within the free troposphere, the Izaña Atmospheric Research Station in Tenerife. At JFJ, correlations with parameters of physical properties of ambient particles, meteorology and air mass characteristics do not show a single best estimator to predict INP concentrations, emphasizing the complexity of ice nucleation in the free troposphere. Increases in INP concentrations of a temporary nature were observed in the free troposphere during Saharan dust events and marine air mass influence, which

  3. Measured soil water concentrations of cadmium and zinc in plant pots and estimated leaching outflows from contaminated soils

    DEFF Research Database (Denmark)

    Holm, P.E.; Christensen, T.H.

    1998-01-01

    Soil water concentrations of cadmium and zinc were measured in plant pots with 15 contaminated soils which differed in origin, texture, pH (5.1-7.8) and concentrations of cadmium (0.2-17 mg Cd kg(-1)) and zinc (36-1300 mg Zn kg(-1)). The soil waters contained total concentrations of 0.5 to 17 mu g...... to 0.1% per year of the total soil content of cadmium and zinc. The measured soil water concentrations of cadmium and zinc did not correlate linearly with the corresponding soil concentrations but correlated fairly well with concentrations measured in Ca(NO(3))(2) extracts of the soils and with soil...... water concentrations estimated from soil concentrations and pH. Such concentration estimates may be useful for estimating amounts of cadmium and zinc being leached from soils....

  4. Dihydrogenimidazole modified silica-sulfonated poly(ether ether ketone) hybrid materials as electrolyte membranes for direct ethanol fuel cells

    International Nuclear Information System (INIS)

    Roelofs, Kimball S.; Hirth, Thomas; Schiestel, Thomas

    2011-01-01

    The present study reports on dihydrogenimidazole modified inorganic-organic mixed matrix membranes for possible application as a proton exchange membrane in direct ethanol fuel cells. The polymeric phase consisted mainly of sulfonated poly(ether ether ketone) (sPEEK) with a sulfonation degree of 55%. The inorganic phase was built up from hydrophilic fumed silica particles interconnected with partially hydrolyzed and condensed tetraethoxysilane with a total inorganic loading of 27.3%. This inorganic phase was further modified with N-(3-triethoxysilylpropyl)-4,5-dihydroimidazole (DHIM), which consists of an hydrolyzable inorganic part and a functional organic group. The influence of the modifier on the mixed matrix system was studied by means of various modifier concentrations in various aqueous-ethanolic systems (water, 2 M and 4 M ethanol). Modifier concentration and ethanol concentration of the ethanol-water mixture exhibited significant but opposite effects on the liquid uptake of the mixed matrix membranes. The proton conductivity as well as the proton diffusion coefficient as a function of modifier content showed a linear decrease. The proton conductivity as a function of temperature showed Arrhenius behavior and the activation energy of the mixed matrix membranes was 43.9 ± 2.6 kJ mol -1 . High selectivity of proton diffusion coefficient to ethanol permeability coefficient was obtained with high modifier concentrations. At low modifier concentrations, this selectivity was dominated by ethanol permeation and at high modifier concentrations by proton diffusion. The main electrolyte properties can be optimized by setting the DHIM content in mixed matrix membrane. With this approach, tailor-made membranes can be prepared for possible application in direct ethanol fuel cells.

  5. Dihydrogenimidazole modified silica-sulfonated poly(ether ether ketone) hybrid materials as electrolyte membranes for direct ethanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Roelofs, Kimball S.; Hirth, Thomas [Fraunhofer Institute for Interfacial Engineering and Biotechnology, Nobelstr. 12, 70569 Stuttgart (Germany); Schiestel, Thomas, E-mail: Thomas.Schiestel@igb.fraunhofer.de [Fraunhofer Institute for Interfacial Engineering and Biotechnology, Nobelstr. 12, 70569 Stuttgart (Germany)

    2011-05-25

    The present study reports on dihydrogenimidazole modified inorganic-organic mixed matrix membranes for possible application as a proton exchange membrane in direct ethanol fuel cells. The polymeric phase consisted mainly of sulfonated poly(ether ether ketone) (sPEEK) with a sulfonation degree of 55%. The inorganic phase was built up from hydrophilic fumed silica particles interconnected with partially hydrolyzed and condensed tetraethoxysilane with a total inorganic loading of 27.3%. This inorganic phase was further modified with N-(3-triethoxysilylpropyl)-4,5-dihydroimidazole (DHIM), which consists of an hydrolyzable inorganic part and a functional organic group. The influence of the modifier on the mixed matrix system was studied by means of various modifier concentrations in various aqueous-ethanolic systems (water, 2 M and 4 M ethanol). Modifier concentration and ethanol concentration of the ethanol-water mixture exhibited significant but opposite effects on the liquid uptake of the mixed matrix membranes. The proton conductivity as well as the proton diffusion coefficient as a function of modifier content showed a linear decrease. The proton conductivity as a function of temperature showed Arrhenius behavior and the activation energy of the mixed matrix membranes was 43.9 {+-} 2.6 kJ mol{sup -1}. High selectivity of proton diffusion coefficient to ethanol permeability coefficient was obtained with high modifier concentrations. At low modifier concentrations, this selectivity was dominated by ethanol permeation and at high modifier concentrations by proton diffusion. The main electrolyte properties can be optimized by setting the DHIM content in mixed matrix membrane. With this approach, tailor-made membranes can be prepared for possible application in direct ethanol fuel cells.

  6. Combined radiation-protective and radiation-sensitizing agents. IV. Measurement of intracellular protector concentrations

    International Nuclear Information System (INIS)

    Koch, C.J.; Stobbe, C.C.; Hettiaratchi, P.

    1989-01-01

    Radiosensitization of hypoxic V79 Chinese hamster cells by 0.5 mM misonidazole at approximately 0-4 degrees C is substantially enhanced by pretreating the cells overnight with 0.1 mM buthionine sulfoximine, which lowers the cellular glutathione content to 5% of control values (from 4 mM to approximately 0.2 mM). The enhanced sensitization is reversed by concentrations of exogenous cysteine that are much lower (0.02 mM) than the original glutathione content. Reduced Co-enzyme A affords reversal of the enhancing effect at concentrations of about 1 mM. Sodium ascorbate gives no protection at all even at concentrations of 2 mM. The intracellular concentration of the reducing agents was measured using a spin-through oil technique. There was no diffusion of Co-A (MW greater than 750) or ascorbate (excluded by charge) into the cells. In contrast, cysteine was rapidly concentrated by factors of 4-10, even at the low temperatures used. Extracellular ascorbate's inability to radioprotect argues against electron transfer across the cell membrane as a mechanism for radioprotection. This mechanism could have explained the ability of exogenous thiols to radioprotect in former studies using glutathione, and in the present studies using Co-A. The potential of cysteine to be concentrated by cells poses a problem in the interpretation of exogenous protection by non-diffusing thiols, since trace contamination by cysteine could lead to the actual protection observed. Cysteine could also be formed by exchange reactions of exogenous thiols with the disulfide of cysteine, present in all media formulations

  7. Changes of brain metabolite concentrations during maturation in different brain regions measured by chemical shift imaging.

    Science.gov (United States)

    Bültmann, Eva; Nägele, Thomas; Lanfermann, Heinrich; Klose, Uwe

    2017-01-01

    We examined the effect of maturation on the regional distribution of brain metabolite concentrations using multivoxel chemical shift imaging. From our pool of pediatric MRI examinations, we retrospectively selected patients showing a normal cerebral MRI scan or no pathologic signal abnormalities at the level of the two-dimensional 1H MRS-CSI sequence and an age-appropriate global neurological development, except for focal neurological deficits. Seventy-one patients (4.5 months-20 years) were identified. Using LC Model, spectra were evaluated from voxels in the white matter, caudate head, and corpus callosum. The concentration of total N-acetylaspartate increased in all regions during infancy and childhood except in the right caudate head where it remained constant. The concentration of total creatine decreased in the caudate nucleus and splenium and minimally in the frontal white matter and genu. It remained largely constant in the parietal white matter. The concentration of choline-containing compounds had the tendency to decrease in all regions except in the parietal white matter where it remained constant. The concentration of myoinositol decreased slightly in the splenium and right frontal white matter, remained constant on the left side and in the caudate nucleus, and rose slightly in the parietal white matter and genu. CSI determined metabolite concentrations in multiple cerebral regions during routine MRI. The obtained data will be helpful in future pediatric CSI measurements deciding whether the ratios of the main metabolites are within the range of normal values or have to be considered as probably pathologic.

  8. Changes of brain metabolite concentrations during maturation in different brain regions measured by chemical shift imaging

    International Nuclear Information System (INIS)

    Bueltmann, Eva; Lanfermann, Heinrich; Naegele, Thomas; Klose, Uwe

    2017-01-01

    We examined the effect of maturation on the regional distribution of brain metabolite concentrations using multivoxel chemical shift imaging. From our pool of pediatric MRI examinations, we retrospectively selected patients showing a normal cerebral MRI scan or no pathologic signal abnormalities at the level of the two-dimensional 1H MRS-CSI sequence and an age-appropriate global neurological development, except for focal neurological deficits. Seventy-one patients (4.5 months-20 years) were identified. Using LC Model, spectra were evaluated from voxels in the white matter, caudate head, and corpus callosum. The concentration of total N-acetylaspartate increased in all regions during infancy and childhood except in the right caudate head where it remained constant. The concentration of total creatine decreased in the caudate nucleus and splenium and minimally in the frontal white matter and genu. It remained largely constant in the parietal white matter. The concentration of choline-containing compounds had the tendency to decrease in all regions except in the parietal white matter where it remained constant. The concentration of myoinositol decreased slightly in the splenium and right frontal white matter, remained constant on the left side and in the caudate nucleus, and rose slightly in the parietal white matter and genu. CSI determined metabolite concentrations in multiple cerebral regions during routine MRI. The obtained data will be helpful in future pediatric CSI measurements deciding whether the ratios of the main metabolites are within the range of normal values or have to be considered as probably pathologic. (orig.)

  9. Changes of brain metabolite concentrations during maturation in different brain regions measured by chemical shift imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bueltmann, Eva; Lanfermann, Heinrich [Hannover Medical School, Institute of Diagnostic and Interventional Neuroradiology, Hannover (Germany); Naegele, Thomas [University of Tuebingen, Department of Diagnostic and Interventional Neuroradiology, Radiological University Hospital, Tuebingen (Germany); Klose, Uwe [University of Tuebingen, Section of Experimental MR of the CNS, Department of Neuroradiology, Radiological University Hospital, Tuebingen (Germany)

    2017-01-15

    We examined the effect of maturation on the regional distribution of brain metabolite concentrations using multivoxel chemical shift imaging. From our pool of pediatric MRI examinations, we retrospectively selected patients showing a normal cerebral MRI scan or no pathologic signal abnormalities at the level of the two-dimensional 1H MRS-CSI sequence and an age-appropriate global neurological development, except for focal neurological deficits. Seventy-one patients (4.5 months-20 years) were identified. Using LC Model, spectra were evaluated from voxels in the white matter, caudate head, and corpus callosum. The concentration of total N-acetylaspartate increased in all regions during infancy and childhood except in the right caudate head where it remained constant. The concentration of total creatine decreased in the caudate nucleus and splenium and minimally in the frontal white matter and genu. It remained largely constant in the parietal white matter. The concentration of choline-containing compounds had the tendency to decrease in all regions except in the parietal white matter where it remained constant. The concentration of myoinositol decreased slightly in the splenium and right frontal white matter, remained constant on the left side and in the caudate nucleus, and rose slightly in the parietal white matter and genu. CSI determined metabolite concentrations in multiple cerebral regions during routine MRI. The obtained data will be helpful in future pediatric CSI measurements deciding whether the ratios of the main metabolites are within the range of normal values or have to be considered as probably pathologic. (orig.)

  10. Mixing layer height measurements determines influence of meteorology on air pollutant concentrations in urban area

    Science.gov (United States)

    Schäfer, Klaus; Blumenstock, Thomas; Bonn, Boris; Gerwig, Holger; Hase, Frank; Münkel, Christoph; Nothard, Rainer; von Schneidemesser, Erika

    2015-10-01

    Mixing layer height (MLH) is a key parameter to determine the influence of meteorological parameters upon air pollutants such as trace gas species and particulate concentrations near the surface. Meteorology, and MLH as a key parameter, affect the budget of emission source strengths, deposition, and accumulation. However, greater possibilities for the application of MLH data have been identified in recent years. Here, the results of measurements in Berlin in 2014 are shown and discussed. The concentrations of NO, NO2, O3, CO, PM1, PM2.5, PM10 and about 70 volatile organic compounds (anthropogenic and biogenic of origin) as well as particle size distributions and contributions of SOA and soot species to PM were measured at the urban background station of the Berlin air quality network (BLUME) in Nansenstr./Framstr., Berlin-Neukölln. A Vaisala ceilometer CL51, which is a commercial mini-lidar system, was applied at that site to detect the layers of the lower atmosphere in real time. Special software for these ceilometers with MATLAB provided routine retrievals of MLH from vertical profiles of laser backscatter data. Five portable Bruker EM27/SUN FTIR spectrometers were set up around Berlin to detect column averaged abundances of CO2 and CH4 by solar absorption spectrometry. Correlation analyses were used to show the coupling of temporal variations of trace gas compounds and PM with MLH. Significant influences of MLH upon NO, NO2, PM10, PM2.5, PM1 and toluene (marker for traffic emissions) concentrations as well as particle number concentrations in the size modes 70 - 100 nm, 100 - 200 nm and 200 - 500 nm on the basis of averaged diurnal courses were found. Further, MLH was taken as important auxiliary information about the development of the boundary layer during each day of observations, which was required for the proper estimation of CO2 and CH4 source strengths from Berlin on the basis of atmospheric column density measurements.

  11. Atmospheric CO2 Concentration Measurements with Clouds from an Airborne Lidar

    Science.gov (United States)

    Mao, J.; Abshire, J. B.; Kawa, S. R.; Riris, H.; Allan, G. R.; Hasselbrack, W. E.; Numata, K.; Chen, J. R.; Sun, X.; DiGangi, J. P.; Choi, Y.

    2017-12-01

    Globally distributed atmospheric CO2 concentration measurements with high precision, low bias and full seasonal sampling are crucial to advance carbon cycle sciences. However, two thirds of the Earth's surface is typically covered by clouds, and passive remote sensing approaches from space are limited to cloud-free scenes. NASA Goddard is developing a pulsed, integrated-path differential absorption (IPDA) lidar approach to measure atmospheric column CO2 concentrations, XCO2, from space as a candidate for NASA's ASCENDS mission. Measurements of time-resolved laser backscatter profiles from the atmosphere also allow this technique to estimate XCO2 and range to cloud tops in addition to those to the ground with precise knowledge of the photon path-length. We demonstrate this measurement capability using airborne lidar measurements from summer 2017 ASCENDS airborne science campaign in Alaska. We show retrievals of XCO2 to ground and to a variety of cloud tops. We will also demonstrate how the partial column XCO2 to cloud tops and cloud slicing approach help resolving vertical and horizontal gradient of CO2 in cloudy conditions. The XCO2 retrievals from the lidar are validated against in situ measurements and compared to the Goddard Parameterized Chemistry Transport Model (PCTM) simulations. Adding this measurement capability to the future lidar mission for XCO2 will provide full global and seasonal data coverage and some information about vertical structure of CO2. This unique facility is expected to benefit atmospheric transport process studies, carbon data assimilation in models, and global and regional carbon flux estimation.

  12. Evaluation of uncertainties in femtoampere current measurement for the number concentration standard of aerosol nanoparticles

    International Nuclear Information System (INIS)

    Sakurai, Hiromu; Ehara, Kensei

    2011-01-01

    We evaluated uncertainties in current measurement by the electrometer at the current level on the order of femtoamperes. The electrometer was the one used in the Faraday-cup aerosol electrometer of the Japanese national standard for number concentration of aerosol nanoparticles in which the accuracy of the absolute current is not required, but the net current which is obtained as the difference in currents under two different conditions must be measured accurately. The evaluation was done experimentally at the current level of 20 fA, which was much smaller than the intervals between the electrometer's calibration points at +1, +0.5, −0.5 and −1 pA. The slope of the response curve for the relationship between the 'true' and measured current, which is crucial in the above measurement, was evaluated locally at many different points within the ±1 pA range for deviation from the slope determined by a linear regression of the calibration data. The sum of the current induced by a flow of charged particles and a bias current from a current-source instrument was measured by the electrometer while the particle current was toggled on and off. The net particle current was obtained as the difference in the measured currents between the toggling, while at the same time the current was estimated from the particle concentration read by a condensation particle counter. The local slope was calculated as the ratio of the measured to estimated currents at each bias current setting. The standard deviation of the local slope values observed at varied bias currents was about 0.003, which was calculated by analysis of variance (ANOVA) for the treatment of the bias current. The combined standard uncertainty of the slope, which was calculated from the uncertainty of the slope by linear regression and the variability of the slope, was calculated to be about 0.004

  13. Instruments to measure radon activity concentration or exposure to radon. Interlaboratory comparison 2011

    International Nuclear Information System (INIS)

    Foerster, Elisabeth; Beck, Thomas; Buchroeder, Helmut; Doering, Joachim; Schmidt, Volkmar

    2011-10-01

    According to the Directive 96/29/EURATOM the monitoring of occupational radiation exposures shall base on individual measurements carried out by an approved dosimetric service. Pursuant to the European Directive an approved dosimetric service is a body responsible for the calibration, reading or interpretation of individual monitoring devices.., whose capacity to act in this respect is recognized by the competent authorities. This concept will also be applied to radon services issuing passive radon measurement devices. Passive radon measurement devices 1 using solid state nuclear track detectors or electrets are recommended for individual monitoring of exposures to radon. German regulations lay down that radon measuring devices are appropriate for purposes of occupational radiation monitoring if the devices are issued by recognized radon measurement services, and the measurement service submits devices of the same type issued for radon monitoring to regular intercomparisons conducted by BfS. A radon measuring service is recognized by the competent authority if it proves its organizational and technical competence, e. g. by accreditation. These regulations have been introduced in the area of occupational radiation exposures. Nevertheless, it is recommended that radon measuring services which carry out radon measurements in other areas (e.g. dwellings) should subject themselves to these measures voluntarily. The interlaboratory comparisons comprise the organization, exposure, and evaluation of measurements of radon activity concentration or exposure to radon. The comparisons only concern radon-222; radon-220 is not in the scope. Radon services being interested can get further information from the website www.bfs.de/de/ion/radon/fachinfomessung/vergleichspruefungen.html and from the European Information System on Proficiency Testing Schemes (eptis) available in the internet. (orig.)

  14. Instruments to measure radon-222 activity concentration or exposure to radon-222. Intercomparison 2014

    International Nuclear Information System (INIS)

    Foerster, Elisabeth; Beck, Thomas; Buchroeder, Helmut; Doering, Joachim; Schmidt, Volkmar

    2014-10-01

    According to the Directive 96/29/EURATOM the monitoring of occupational radiation exposures shall base on individual measurements carried out by an approved dosimetric service. Pursuant to the European Directive an approved dosimetric service is a body responsible for the calibration, reading or interpretation of individual monitoring devices.., whose capacity to act in this respect is recognized by the competent authorities. This concept will also be applied to radon services issuing passive radon measurement devices. Passive radon measurement devices 1 using solid state nuclear track detectors or electrets are recommended for individual monitoring of exposures to radon. German regulations lay down that radon measuring devices are appropriate for purposes of occupational radiation monitoring if the devices are issued by recognized radon measurement services, and the measurement service submits devices of the same type issued for radon monitoring to regular intercomparisons conducted by the Bundesamt fuer Strahlenschutz (BfS). A radon measuring service is recognized by the competent authority if it proves its organisational and technical competence, e. g. by accreditation. These regulations have been introduced in the area of occupational radiation exposures. Nevertheless, it is recommended that radon measuring services which carry out radon measurements in other areas (e.g. dwellings) should subject themselves to these measures voluntarily. The interlaboratory comparisons comprise the organization, exposure, and evaluation of measurements of radon activity concentration or exposure to radon. The comparisons only concern radon-222; radon-220 is not in the scope. Radon services being interested can get further information from the European Information System on Proficiency Testing Schemes (EPTIS) and from the BfS websites.

  15. Non-destructive measurements of uranium and thorium concentrations and quantities

    International Nuclear Information System (INIS)

    Dragnev, T.N.; Damjanov, B.P.; Karamanova, J.S.

    1979-01-01

    The passive X-ray fluorescent-gamma spectrometry method and technique for uranium concentration measurements was developed and tested. It is based on the measurement of the intensity ratios of self-excited Ksub(α) X-rays of uranium to the intensity of the combined peak with 92.8 keV average energy. The last peak has 92.367 and 92.792 keV gamma rays of 234 Th, representing the activities of 238 U and its daughter isotopes, and 93.35 keV Th Ksub(α) X-rays representing the activities of 235 U and its daughters. The results of the measurements do not depend on the size and the shape of the measurements. The procedure is developed to take automatically into account the presence of any absorber or cladding between the measured sample and the detector. The attainable precision of the measurements (at 95% confidence level) is 0.2 - 0.3%. If combined with enrichment measurements, and after suitable empirical calibration, the method can be used without standards. Gamma-spectrometric measurements of 238 U and 232 Th are based on the daughter isotopes' gamma activities. However, this is correct only when there is a corresponding equilibrium between 238 U and 232 Th and the daughter isotopes' activities. Where such equilibrium is not reached the status of the daughter products' activities regarding equilibrium, has to be taken into account. Two methods of quantitative corrections are proposed: (i) The use of an absolute determination of the 228 Ac/ 224 Ra activity ratio through self-calibrated measurements and individual activities and their correlation with the equilibrium activities. (ii) Use of two of the same sample measurements at two different moments during the unrestored equilibrium and the correlation of the measurement results with the 232 Th activity. This method can be generally applied. (author)

  16. Effect of dimethylamine on the gas phase sulfuric acid concentration measured by Chemical Ionization Mass Spectrometry

    CERN Document Server

    Rondo, L.; Kürten, A.; Adamov, A.; Bianchi, F.; Breitenlechner, M.; Duplissy, J.; Franchin, A.; Dommen, J.; Donahue, N. M.; Dunne, E. M.; Flagan, R. C.; Hakala, J.; Hansel, A.; Keskinen, H.; Kim, J.; Jokinen, T.; Lehtipalo, K.; Leiminger, M.; Praplan, A.; Riccobono, F.; Rissanen, M. P.; Sarnela, N.; Schobesberger, S.; Simon, M.; Sipilä, M.; Smith, J. N.; Tomé, A.; Tröstl, J.; Tsagkogeorgas, G.; Vaattovaara, P.; Winkler, P. M.; Williamson, C.; Wimmer, D.; Baltensperger, U.; Kirkby, J.; Kulmala, M.; Petäjä, T.; Worsnop, D. R.; Curtius, J.

    2016-01-01

    Sulfuric acid is widely recognized as a very important substance driving atmospheric aerosolnucleation. Based on quantum chemical calculations it has been suggested that the quantitative detectionof gas phase sulfuric acid (H2SO4) by use of Chemical Ionization Mass Spectrometry (CIMS) could be biased inthe presence of gas phase amines such as dimethylamine (DMA). An experiment (CLOUD7 campaign) was setup at the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber to investigate the quantitative detection ofH2SO4in the presence of dimethylamine by CIMS at atmospherically relevant concentrations. For the first time inthe CLOUD experiment, the monomer sulfuric acid concentration was measured by a CIMS and by two CI-APi-TOF(Chemical Ionization-Atmospheric Pressure interface-Time Of Flight) mass spectrometers. In addition, neutralsulfuric acid clusters were measured with the CI-APi-TOFs. The CLOUD7 measurements show that in the presenceof dimethylamine (<5 to 70 pptv) the sulfuric acid monomer measured by the CIMS...

  17. Comparison of total protein concentration in skeletal muscle as measured by the Bradford and Lowry assays.

    Science.gov (United States)

    Seevaratnam, Rajini; Patel, Barkha P; Hamadeh, Mazen J

    2009-06-01

    The Lowry and Bradford assays are the most commonly used methods of total protein quantification, yet vary in several aspects. To date, no comparisons have been made in skeletal muscle. We compared total protein concentrations of mouse red and white gastrocnemius, reagent stability, protein stability and range of linearity using both assays. The Lowry averaged protein concentrations 15% higher than the Bradford with a moderate correlation (r = 0.36, P = 0.01). However, Bland-Altman analysis revealed considerable bias (15.8 +/- 29.7%). Both Lowry reagents and its protein-reagent interactions were less stable over time than the Bradford. The linear range of concentration was smaller for the Lowry (0.05-0.50 mg/ml) than the Bradford (0-2.0 mg/ml). We conclude that the Bradford and Lowry measures of total protein concentration in skeletal muscle are not interchangeable. The Bradford and Lowry assays have various strengths and weaknesses in terms of substance interference and protein size. However, the Bradford provides greater reagent stability, protein-reagent stability and range of linearity, and requires less time to analyse compared to the Lowry assay.

  18. The role and importance of ozone for atmospheric chemistry and methods for measuring its concentration

    Directory of Open Access Journals (Sweden)

    Marković Dragan M.

    2003-01-01

    Full Text Available Depending on where ozone resides, it can protect or harm life on Earth. The thin layer of ozone that surrounds Earth acts as a shield protecting the planet from irradiation by UV light. When it is close to the planet's surface, ozone is a powerful photochemical oxidant that damage, icons frescos, museum exhibits, rubber, plastic and all plant and animal life. Besides the basic properties of some methods for determining the ozone concentration in working and living conditions, this paper presents a detailed description of the electrochemical method. The basic properties of the electrochemical method are used in the construction of mobile equipment for determining the sum of oxidants in the atmosphere. The equipment was used for testing the determination of the ozone concentration in working rooms, where the concentration was at a high level and caused by UV radiation or electrostatic discharge. According to the obtained results, it can be concluded that this equipment for determining the ozone concentration in the atmosphere is very powerful and reproducible in measurements.

  19. Stability of mercury concentration measurements in archived soil and peat samples

    Science.gov (United States)

    Navrátil, Tomáš; Burns, Douglas; Nováková, Tereza; Kaňa, Jiří; Rohovec, Jan; Roll, Michal; Ettler, Vojtěch

    2018-01-01

    Archived soil samples can provide important information on the history of environmental contamination and by comparison with recently collected samples, temporal trends can be inferred. Little previous work has addressed whether mercury (Hg) concentrations in soil samples are stable with long-term storage under standard laboratory conditions. In this study, we have re-analyzed using cold vapor atomic adsorption spectroscopy a set of archived soil samples that ranged from relatively pristine mountainous sites to a polluted site near a non-ferrous metal smelter with a wide range of Hg concentrations (6 - 6485 µg kg-1). Samples included organic and mineral soils and peats with a carbon content that ranged from 0.2 to 47.7%. Soil samples were stored in polyethylene bags or bottles and held in laboratory rooms where temperature was not kept to a constant value. Mercury concentrations in four subsets of samples were originally measured in 2000, 2005, 2006 and 2007, and re-analyzed in 2017, i.e. after 17, 12, 11 and 10 years of storage. Statistical analyses of either separated or lumped data yielded no significant differences between the original and current Hg concentrations. Based on these analyses, we show that archived soil and peat samples can be used to evaluate historical soil mercury contamination.

  20. Real-time measurement of aerosol particle concentration at high temperatures; Hiukkaspitoisuuden reaaliaikainen mittaaminen korkeassa laempoetilassa

    Energy Technology Data Exchange (ETDEWEB)

    Keskinen, J; Hautanen, J; Laitinen, A [Tampere Univ. of Technology (Finland). Physics

    1997-10-01

    The aim of this project is to develop a new method for continuous aerosol particle concentration measurement at elevated temperatures (up to 800-1000 deg C). The measured property of the aerosol particles is the so called Fuchs surface area. This quantity is relevant for diffusion limited mass transfer to particles. The principle of the method is as follows. First, aerosol particles are charged electrically by diffusion charging process. The charging takes place at high temperature. After the charging, aerosol is diluted and cooled. Finally, aerosol particles are collected and the total charge carried by the aerosol particles is measured. Particle collection and charge measurement take place at low temperature. Benefits of this measurement method are: particles are charged in-situ, charge of the particles is not affected by the temperature and pressure changes after sampling, particle collection and charge measurement are carried out outside the process conditions, and the measured quantity is well defined. The results of this study can be used when the formation of the fly ash particles is studied. Another field of applications is the study and the development of gasification processes. Possibly, the method can also be used for the monitoring the operation of the high temperature particle collection devices. (orig.)

  1. Sulfur dioxide concentration measurements in the vicinity of the Albert Funk mining and metallurgical plant complex

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, M

    1976-01-01

    This article discusses the ambient air concentration of sulfur dioxide in the area of Freiberg, GDR. The emission of sulfur dioxide results for the most part from brown coal combustion in heat and power plants and in metallurgical plants. Sulfur dioxide emission from neighboring industrial centers such as Dresden and North Bohemian towns affects the Freiburg area to some extent. The use of brown coal in household heating contributes an average of 50 kg of sulfur dioxide emission per coal burning household annually. A total of 1260 measurements at 28 points in the vicinity of Freiberg were made in the year 1972 in evaluating the concentration of sulfur dioxide present in the air. In 75% of the measurements the concentrations were below 0.15 mg/mat3, in 12% between 0.15 and 0.2 mg/mat3, in 7% between 0.2 and 0.3 mg/mat3 and in 6% between 0.3 and 0.5 mg/mat3. The results are described as average industrial pollution. The influence of air temperature, wind velocity, fog, season and time of day are also discussed. (4 refs.) (In German)

  2. Outdoor measurements of a photovoltaic system using diffractive spectrum-splitting and concentration

    Directory of Open Access Journals (Sweden)

    N. Mohammad

    2016-09-01

    Full Text Available In a single-bandgap absorber, photons having energy less than the bandgap are not absorbed, while those having energy larger than the bandgap lose the excess energy via thermalization. We present outdoor measurements of a photovoltaic system that overcomes these losses via spectrum splitting and concentration using a planar diffractive optic. The system was comprised of the diffractive optic coupled with GaInP and CIGS solar cells. The optic provides a geometric concentration of 3X for each solar cell. It is easily fabricated by single-step grayscale lithography and it is ultra-thin with a maximum thickness of only 2.5μm. Electrical measurements under direct sunlight demonstrated an increase of ∼25% in total output power compared to the reference case without spectrum splitting and concentration. Since different bandgaps are in the same plane, the proposed photovoltaic system successfully circumvents the lattice-matching and current-matching issues in conventional tandem multi-junction solar cells. This system is also tolerant to solar spectrum variation and fill-factor degradation of constitutive solar cells.

  3. Concentration of atomic hydrogen in a dielectric barrier discharge measured by two-photon absorption fluorescence

    Science.gov (United States)

    Dvořák, P.; Talába, M.; Obrusník, A.; Kratzer, J.; Dědina, J.

    2017-08-01

    Two-photon absorption laser-induced fluorescence (TALIF) was utilized for measuring the concentration of atomic hydrogen in a volume dielectric barrier discharge (DBD) ignited in mixtures of Ar, H2 and O2 at atmospheric pressure. The method was calibrated by TALIF of krypton diluted in argon at atmospheric pressure, proving that three-body collisions had a negligible effect on quenching of excited krypton atoms. The diagnostic study was complemented with a 3D numerical model of the gas flow and a zero-dimensional model of the chemistry in order to better understand the reaction kinetics and identify the key pathways leading to the production and destruction of atomic hydrogen. It was determined that the density of atomic hydrogen in Ar-H2 mixtures was in the order of 1021 m-3 and decreased when oxygen was added into the gas mixture. Spatially resolved measurements and simulations revealed a sharply bordered region with low atomic hydrogen concentration when oxygen was added to the gas mixture. At substoichiometric oxygen/hydrogen ratios, this H-poor region is confined to an area close to the gas inlet and it is shown that the size of this region is not only influenced by the chemistry but also by the gas flow patterns. Experimentally, it was observed that a decrease in H2 concentration in the feeding Ar-H2 mixture led to an increase in H production in the DBD.

  4. Performance of a low-cost methane sensor for ambient concentration measurements in preliminary studies

    Directory of Open Access Journals (Sweden)

    W. Eugster

    2012-08-01

    Full Text Available Methane is the second most important greenhouse gas after CO2 and contributes to global warming. Its sources are not uniformly distributed across terrestrial and aquatic ecosystems, and most of the methane flux is expected to stem from hotspots which often occupy a very small fraction of the total landscape area. Continuous time-series measurements of CH4 concentrations can help identify and locate these methane hotspots. Newer, low-cost trace gas sensors such as the Figaro TGS 2600 can detect CH4 even at ambient concentrations. Hence, in this paper we tested this sensor under real-world conditions over Toolik Lake, Alaska, to determine its suitability for preliminary studies before placing more expensive and service-intensive equipment at a given locality. A reasonably good agreement with parallel measurements made using a Los Gatos Research FMA 100 methane analyzer was found after removal of the strong sensitivities for temperature and relative humidity. Correcting for this sensitivity increased the absolute accuracy required for in-depth studies, and the reproducibility between two TGS 2600 sensors run in parallel is very good. We conclude that the relative CH4 concentrations derived from such sensors are sufficient for preliminary investigations in the search of potential methane hotspots.

  5. Measurement of the deuterium concentration in water samples using a CW chemical deuterium fluoride laser

    International Nuclear Information System (INIS)

    Trautmann, M.

    1979-10-01

    In this study a new method for the determination of the deuterium content in water samples is described. The absorption of the radiation of a CW deuterium fluoride laser by the isotope HDO in the water vapor of the sample is measured by means of an optoacoustic detector (spectrophone). Thereby advantage is taken of the fact that H 2 O hardly absorbs the laser radiation and that D 2 O only exists in negligible concentrations. The isotope ratio of hydrogen can be calculated from the measured relative concentration of HDO. In the course of this investigation the relative absorption cross sections of HDO for the different laser lines were determined. It was thereby established that there exists a very good coincidence of an HDO absorption line with the 2P2 laser line. Using a very sensitive nonresonant spectrophone the relative concentration of HDO in natural water samples could be determined with an accuracy of about 10%. The experiments also demonstrated that with appropriate improvements made to the apparatus and using a second spectrophone as a reference it should be possible to increase this accuracy to 0,1%. (orig.)

  6. A method of measuring gold nanoparticle concentrations by x-ray fluorescence for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Wu Di; Li Yuhua; Wong, Molly D.; Liu Hong [Center for Bioengineering and School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States)

    2013-05-15

    Purpose: This paper reports a technique that enables the quantitative determination of the concentration of gold nanoparticles (GNPs) through the accurate detection of their fluorescence radiation in the diagnostic x-ray spectrum. Methods: Experimentally, x-ray fluorescence spectra of 1.9 and 15 nm GNP solutions are measured using an x-ray spectrometer, individually and within chicken breast tissue samples. An optimal combination of excitation and emission filters is determined to segregate the fluorescence spectra at 66.99 and 68.80 keV from the background scattering. A roadmap method is developed that subtracts the scattered radiation (acquired before the insertion of GNP solutions) from the signal radiation acquired after the GNP solutions are inserted. Results: The methods effectively minimize the background scattering in the spectrum measurements, showing linear relationships between GNP solutions from 0.1% to 10% weight concentration and from 0.1% to 1.0% weight concentration inside a chicken breast tissue sample. Conclusions: The investigation demonstrated the potential of imaging gold nanoparticles quantitatively in vivo for in-tissue studies, but future studies will be needed to investigate the ability to apply this method to clinical applications.

  7. Evaluation of correlating factors between 238U concentration measured in fine and course atmospheric particles

    International Nuclear Information System (INIS)

    Peixoto, Claudia Marques; Jacomino, Vanusa Maria Feliciano; Barreto, Alberto Avelar; Dias, Vagner Silva; Dias, Fabiana Ferrari

    2009-01-01

    Air quality is ever more important in function of the enormous proportion of human actions that have affected the environment over the last two centuries. Particulate material is one among many pollutants that can cause great risk to human health and the environment. It can be classified as: Total Suspended Particles (TSP), defined simply as particles with less than 50 μm aerodynamic diameter (one group of these particles can be inhaled and may cause health problems, while others may unfavorably affect the population's quality of life, interfering in environmental conditions and impairing normal community activities); and Inhalable Particles (PM 10 ), defined as those particles with less than 10 μm aerodynamic diameter. These particles penetrate the respiratory system and can reach pulmonary alveoli due to their small size, causing serious health damage. The Nuclear Technology Development Center (CDTN) has monitored air quality around its installations since 2000. CDTN's Environmental Monitoring Program (EMP) includes monitoring radioactivity levels contained in atmospheric TSP. In order to optimize its program, CDTN is carrying out a study to estimate the correlation between concentrations of particulate material measured in TSP and those measured in PM 10 , PI 2.5 and PI 1 , as well as determination of activity concentration for each controlled radionuclide in all parts. The objective of this study is to present preliminary results and report 238 U activity concentration results. (author)

  8. Indoor radon concentration measurement in the dwellings of Al-Jauf region of Saudi Arabia

    International Nuclear Information System (INIS)

    Al-Jarallah, M. I.; Fazal ur, Rehman

    2006-01-01

    Indoor radon concentration measurement in the dwellings of Al-Jauf region of Saudi Arabia was carried out using passive radon dosemeters. The objective of this radon survey was to obtain representative indoor radon data of Al-Jauf region. The study is a continuation of radon survey in main cities of Saudi Arabia which constitutes a baseline for Saudi Arabia in the Radon World Atlas. A total of 318 passive radon dosemeters were distributed randomly in the region and placed for a period of 1 y starting from April 2004 to April 2005. The results of indoor radon concentration measurement in 136 dwellings distributed in Al-Jauf region are presented. The remaining dosemeters were lost in the dwellings or mishandled. The results showed that the average, minimum, maximum radon concentrations and standard deviation were 35, 7, 168 and 30 Bq m -3 , respectively. Geometric mean and geometric standard deviation of the radon distribution were found to be 28 and 1.83, respectively. (authors)

  9. Measurement error potential and control when quantifying volatile hydrocarbon concentrations in soils

    International Nuclear Information System (INIS)

    Siegrist, R.L.

    1991-01-01

    Due to their widespread use throughout commerce and industry, volatile hydrocarbons such as toluene, trichloroethene, and 1, 1,1-trichloroethane routinely appears as principal pollutants in contamination of soil system hydrocarbons is necessary to confirm the presence of contamination and its nature and extent; to assess site risks and the need for cleanup; to evaluate remedial technologies; and to verify the performance of a selected alternative. Decisions regarding these issues have far-reaching impacts and, ideally, should be based on accurate measurements of soil hydrocarbon concentrations. Unfortunately, quantification of volatile hydrocarbons in soils is extremely difficult and there is normally little understanding of the accuracy and precision of these measurements. Rather, the assumptions often implicitly made that the hydrocarbon data are sufficiently accurate for the intended purpose. This appear presents a discussion of measurement error potential when quantifying volatile hydrocarbons in soils, and outlines some methods for understanding the managing these errors

  10. Analysis of problems and failures in the measurement of soil-gas radon concentration.

    Science.gov (United States)

    Neznal, Martin; Neznal, Matěj

    2014-07-01

    Long-term experience in the field of soil-gas radon concentration measurements allows to describe and explain the most frequent causes of failures, which can appear in practice when various types of measurement methods and soil-gas sampling techniques are used. The concept of minimal sampling depth, which depends on the volume of the soil-gas sample and on the soil properties, is shown in detail. Consideration of minimal sampling depth at the time of measurement planning allows to avoid the most common mistakes. The ways how to identify influencing parameters, how to avoid a dilution of soil-gas samples by the atmospheric air, as well as how to recognise inappropriate sampling methods are discussed. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Methane concentration and isotopic composition measurements with a mid-infrared quantum-cascade laser

    Science.gov (United States)

    Kosterev, A. A.; Curl, R. F.; Tittel, F. K.; Gmachl, C.; Capasso, F.; Sivco, D. L.; Baillargeon, J. N.; Hutchinson, A. L.; Cho, A. Y.

    1999-01-01

    A quantum-cascade laser operating at a wavelength of 8.1 micrometers was used for high-sensitivity absorption spectroscopy of methane (CH4). The laser frequency was continuously scanned with current over more than 3 cm-1, and absorption spectra of the CH4 nu 4 P branch were recorded. The measured laser linewidth was 50 MHz. A CH4 concentration of 15.6 parts in 10(6) ( ppm) in 50 Torr of air was measured in a 43-cm path length with +/- 0.5-ppm accuracy when the signal was averaged over 400 scans. The minimum detectable absorption in such direct absorption measurements is estimated to be 1.1 x 10(-4). The content of 13CH4 and CH3D species in a CH4 sample was determined.

  12. Great isotope effects in compounding of sodium isotopes by macrocyclic polyether

    International Nuclear Information System (INIS)

    Knoechel, A.; Wilken, R.D.

    1978-01-01

    Isotope effects appear in the compounding of the two sodium isotopes 24 Na + and 22 Na + with macrocyclic polyethers, whose value was determined for the 13 best known polyethers. A radiometric process was used for determining the different half life periods of the nuclides used. To separate the compound and non-compound types, these were distributed between water and chloroform. The isotope ratio in the chloroform phase was compared with the output isotope ratio and the separation facfor determined from this. When using crown ethers, there was enrichment of 24 Na + by a significant amount (large crown ether) up to 3.1 +- 0.4% for 18 crown 6. The remarkably high results can be correlated by Biegeleisen's theory with other chemical conditions. There is a report on the first results of transferring these conditions to the H + /T + system. (orig.) [de

  13. Study on the radiation degradation of polyether-polyurethane induced by electron beam

    International Nuclear Information System (INIS)

    Huang Wei; Xiong Jie; Chen Xiaojun; Gao Xiaoling; Xu Yunshu; Fu Yibei

    2007-01-01

    Polyether-urethane samples were irradiated at the dose range from 10 to 2000 kGy by 2 MeV electron beams. Volatile species from the polymer degradation were analyzed quantitatively and qualitatively with GC/MS. Thermal properties and micro-phase separation of the samples were examined by TG and the morphology was studied by TEM and SEM. The results show that the irradiated polyether-polyurethane evolves CO 2 , H 2 , CH 4 and C 2 H 6 , etc. The thermal stabilities between the hard and soft segments in the irradiated samples are different. At high doses, the phase separation in the sample is predominant and the hard segment of sample is more stable. The dose rate affects the soft segment of the irradiated sample much more. (author)

  14. Unloaded polyether type polyurethane foams as solid extractants for trace elements

    International Nuclear Information System (INIS)

    Palagyi, S.; Braun, T.

    1992-01-01

    Polyether type polyurethane foams (PU) are regular stacks of solid quasi-spherical membranes produced by the reaction of polyisocyanates with polyols of polyether nature in the presence of a catalyst and a blowing agent. Contrary to conventional membrane separations, where a solid membrane is merely a differentially separating agent, or a transport medium, PU foams, apart from separation and preconcentration, also retain, i.e., sorb the species on, or in the membranes. Therefore, PU foam membranes can be considered to act as true sorbents. The membrane properties of PU foam sorbents offer unique advantages over conventional bulk type granular sorbents in rapid, versatile and effective separations and preconcentrations of different compounds from fluid samples. Unloaded PU foam sorbents have received considerable attention in the separation of different trace inorganic species. (author) 74 refs.; 1 fig.; 1 tab

  15. Improvement of the ionic conductivity for amorphous polyether electrolytes using supercritical CO2 treatment technology

    International Nuclear Information System (INIS)

    Kwak, Gun-Ho; Tominaga, Yoichi; Asai, Shigeo; Sumita, Masao

    2003-01-01

    The influence of the supercritical carbon dioxide (scCO 2 ) on ionic conductivity for polyether electrolytes based on oligo(oxyethylene glycol) methacrylate with lithium triflate, LiCF 3 SO 3 , has been investigated. In particular, the present research is a first attempt to improve an ion transport behavior of the polyether electrolytes using scCO 2 treatment technique. Consequently, the ionic conductivity of scCO 2 treated samples at room temperature was more than ten times elevated by the scCO 2 treatment under the condition of 10 MPa and 40 deg. C. From the Raman spectroscopy, decrease of aggregate ions and increase of free ions for the scCO 2 treated samples have been observed

  16. Pseudomacrocyclic effect in extraction processes of metal salts by polyethers from nitric acid solutions

    International Nuclear Information System (INIS)

    Yakshin, V.V.; Vilkova, O.M.; Kotlyar, S.A.; Kamalov, G.L.

    1997-01-01

    Comparison of macrocyclic (ME) and pseudmacrocyclic effects (PME), originating by conduct of the metal salt extraction processes (Cs, Sr, In, Zr, Cd, etc) from nitric acid solutions through linear and cyclic polyethers, containing 5 or 6 atoms of ether oxygen and having close molecular masses (290-360), is carried out. It is shown that ordinary ethers practically do not extract the studied metals from nitric acid solutions. By transfer from linear polyethers to their macrocyclic analogs the ME impact is expressed clearly enough: the separation coefficient value grows by tens and hundred times. At the some time the PME role in the extraction processes of metal nitrates through crown-ethers with alkyl and groups is expressed less clearly

  17. Controlled swollen and drug release from urea-cross-linked polyether/siloxane hybrids

    International Nuclear Information System (INIS)

    Santilli, Celso V.; Lopes, Leandro; Pulcinelli, Sandra H.; Chiavacci, Leila A.; Oliveira, Anselmo G.

    2009-01-01

    From a simple synthesis method we produced transparent ureasil cross-linked polyether (poly(ethylene oxide), PEO, or poly (propylene oxide), PPO) networks, whose designed inter cross-linking distance and tunable swell ability was assessed by small angle X-ray scattering on the D11A-SAXS1 beamline of the LNLS, we demonstrated that the controlled drug release from swell able hydrophilic ureasil-PEO materials can be sustained during some days, while from the unswell able ureasil-PPO ones, during some weeks. This outstanding feature conjugated with the bio medically safe formulation of the ureasil cross-linked polyether/siloxane hybrid widen their scope of application to include the domain of soft and implantable drug delivery devices. (author)

  18. Measuring concentrations of selected air pollutants inside California vehicles. Final report

    International Nuclear Information System (INIS)

    Rodes, C.; Sheldon, L.; Whitaker, D.; Clayton, A.; Fitzgerald, K.

    1999-01-01

    This project measured 2-hour integrated concentrations of PM10, PM2.5, metals and a number of organic chemicals including benzene and MTBE inside vehicles on California roadways. Using continuous samplers, particle counts, black carbon, and CO were also measured. In addition to measuring in-vehicle levels, the investigators measured pollutant levels just outside the vehicle, at roadside stations, and ambient air monitoring stations. Different driving scenarios were designed to assess the effects of a number of factors on in-vehicle pollutant levels. These factors included roadway type, carpool lanes, traffic conditions, geographical locations, vehicle type, and vehicle ventilation conditions. The statewide average in-vehicle concentrations of benzene, MTBE, and formaldehyde ranged from 3--22 microg/m 3 , 3--90 microg/m 3 , and 0---22 microg/m 3 , respectively. The ranges of mean PM10 and PM2.5 in-vehicle levels in Sacramento were 20--40 microg/m 3 and 6--22 microg/m 3 , respectively. In general, pollutant levels inside or just outside the vehicles were higher than those measured at the roadside stations or the ambient air stations. In-vehicle pollutant levels were consistently higher in Los Angeles than Sacramento. Pollutant levels measured inside vehicles traveling in a carpool lane were much lower than those in the right-hand, slower lanes. Under the study conditions, factors such as vehicle type and ventilation and little effect on in-vehicle pollutant levels. Other factors, such as roadway type, freeway congestion level, and time-of-day had some influence on in-vehicle pollution levels

  19. Comparison of sources of submicron particle number concentrations measured at two sites in Rochester, NY.

    Science.gov (United States)

    Kasumba, John; Hopke, Philip K; Chalupa, David C; Utell, Mark J

    2009-09-01

    Sources contributing to the submicron particles (100-470 nm) measured between January 2002 and December 2007 at two different New York State Department of Environmental Conservation (NYS DEC) sites in Rochester, NY were identified and apportioned using a bilinear receptor model, positive matrix factorization (PMF). Measurements of aerosol size distributions and number concentrations for particles in the size range of 10-500 nm have been made since December 2001 to date in Rochester. The measurements are being made using a scanning mobility particle sizer (SMPS) consisting of a DMA and a CPC (TSI models 3071 and 3010, respectively). From December 2001 to March 2004, particle measurements were made at the NYS DEC site in downtown Rochester, but it was moved to the eastside of Rochester in May 2004. Each measurement period was divided into three seasons i.e., winter (December, January, and February), summer (June, July, and August), and the transitional periods (March, April, May, September, October, and November) so as to avoid experimental uncertainty resulting from too large season-to-season variability in ambient temperature and solar photon intensity that would lead to unstable/non-stationary size distributions. Therefore, the seasons were analyzed independently for possible sources. Ten sources were identified at both sites and these include traffic, nucleation, residential/commercial heating, industrial emissions, secondary nitrate, ozone- rich secondary aerosol, secondary sulfate, regionally transported aerosol, and a mixed source of nucleation and traffic. These results show that the measured total outdoor particle number concentrations in Rochester generally vary with similar temporal patterns, suggesting that the central monitoring site data can be used to estimate outdoor exposure in other parts of the city.

  20. Energy Yield Determination of Concentrator Solar Cells using Laboratory Measurements: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Geisz, John F.; Garcia, Ivan; McMahon, William E.; Steiner, Myles A.; Ochoa, Mario; France, Ryan M.; Habte, Aron; Friedman, Daniel J.

    2015-09-14

    The annual energy conversion efficiency is calculated for a four junction inverted metamorphic solar cell that has been completely characterized in the laboratory at room temperature using measurements fit to a comprehensive optoelectronic model of the multijunction solar cells. A simple model of the temperature dependence is used to predict the performance of the solar cell under varying temperature and spectra characteristic of Golden, CO for an entire year. The annual energy conversion efficiency is calculated by integrating the predicted cell performance over the entire year. The effects of geometric concentration, CPV system thermal characteristics, and luminescent coupling are highlighted. temperature and spectra characteristic of Golden, CO for an entire year. The annual energy conversion efficiency is calculated by integrating the predicted cell performance over the entire year. The effects of geometric concentration, CPV system thermal characteristics, and luminescent coupling are highlighted.