WorldWideScience

Sample records for solid compacted mass

  1. Solid targetry for compact cyclotrons

    International Nuclear Information System (INIS)

    Comor, J.

    2004-01-01

    In this presentation authors present experimental results of solid targetry for compact cyclotrons. It is concluded: Solid targetry is not restricted to large accelerator centers anymore; Small and medium scale radioisotope production is feasible with compact cyclotrons; The availability of versatile solid target systems is expected to boost the radiochemistry of 'exotic' positron emitters

  2. Machine for compacting solid residues

    International Nuclear Information System (INIS)

    Herzog, J.

    1981-11-01

    Machine for compacting solid residues, particularly bulky radioactive residues, constituted of a horizontally actuated punch and a fixed compression anvil, in which the residues are first compacted horizontally and then vertically. Its salient characteristic is that the punch and the compression anvil have embossments on the compression side and interpenetrating plates in the compression position [fr

  3. Mass-Radius diagram for compact stars

    International Nuclear Information System (INIS)

    Carvalho, G A; Jr, R M Marinho; Malheiro, M

    2015-01-01

    The compact stars represent the final stage in the evolution of ordinary stars, they are formed when a star ceases its nuclear fuel, in this point the process that sustain its stability will stop. After this, the internal pressure can no longer stand the gravitational force and the star colapses [2]. In this work we investigate the structure of these stars which are described by the equations of Tolman-Openheimer-Volkof (TOV) [1]. These equations show us how the pressure varies with the mass and radius of the star. We consider the TOV equations for both relativistic and non-relativistic cases. In the case of compact stars (white dwarfs and neutron stars) the internal pressure that balances the gravitational pressure is essentialy the pressure coming from the degeneracy of fermions. To have solved the TOV equations we need a equation of state that shows how this internal pressure is related to the energy density or mass density. Instead of using politropic equations of state we have solved the equations numericaly using the exact relativistic energy equation for the model of fermion gas at zero temperature. We obtain results for the mass-radius relation for white dwarfs and we compared with the results obtained using the politropic equations of state. In addition we discussed a good fit for the mass-radius relation. (paper)

  4. Development of a compaction system for solid waste

    International Nuclear Information System (INIS)

    Nair, J.S.; Roy, P.R.

    1990-01-01

    The Bhabha Atomic Research Centre has set up a Beryllium Pilot Plant at Vashi, New Bombay, which is in operation for nearly a decade now. In view of the high toxicity of beryllium and its compounds, the plant has a specially designed ventilation system with a bank of pre and absolute HEPA filters to prevent the escape of any toxic material into the outside atmosphere. The filters are periodically replaced to maintain efficiency. The used filters are sealed in cardboard cartons and stored in RCC containers. In order to minimise the expenditure on waste disposal, a solid waste compaction system with suitable toolings has been designed and fabricated in the plant. The compaction trials carried out using this system on non-toxic HEPA filters have shown that a reduction by a factor of 3 could be achieved in the overall volume of the filter. It is interesting to note that the actual volume reduction is limited by spring-back effects of the filter media. The paper gives details of the compaction system and presents some of the important results obtained in the trials using non-toxic filters. Efforts are presently being made to incorporate pneumatically operated robot in the place of the existing electromechanical devices for compaction. (author). 2 refs., 6 tabs

  5. Compact hydrogen production systems for solid polymer fuel cells

    Science.gov (United States)

    Ledjeff-Hey, K.; Formanski, V.; Kalk, Th.; Roes, J.

    Generally there are several ways to produce hydrogen gas from carbonaceous fuels like natural gas, oil or alcohols. Most of these processes are designed for large-scale industrial production and are not suitable for a compact hydrogen production system (CHYPS) in the power range of 1 kW. In order to supply solid polymer fuel cells (SPFC) with hydrogen, a compact fuel processor is required for mobile applications. The produced hydrogen-rich gas has to have a low level of harmful impurities; in particular the carbon monoxide content has to be lower than 20 ppmv. Integrating the reaction step, the gas purification and the heat supply leads to small-scale hydrogen production systems. The steam reforming of methanol is feasible at copper catalysts in a low temperature range of 200-350°C. The combination of a small-scale methanol reformer and a metal membrane as purification step forms a compact system producing high-purity hydrogen. The generation of a SPFC hydrogen fuel gas can also be performed by thermal or catalytic cracking of liquid hydrocarbons such as propane. At a temperature of 900°C the decomposition of propane into carbon and hydrogen takes place. A fuel processor based on this simple concept produces a gas stream with a hydrogen content of more than 90 vol.% and without CO and CO2.

  6. Modular compact solid-state modulators for particle accelerators

    Science.gov (United States)

    Zavadtsev, A. A.; Zavadtsev, D. A.; Churanov, D. V.

    2017-12-01

    The building of the radio frequency (RF) particle accelerator needs high-voltage pulsed modulator as a power supply for klystron or magnetron to feed the RF accelerating system. The development of a number of solid-state modulators for use in linear accelerators has allowed to develop a series of modular IGBT based compact solid-state modulators with different parameters. This series covers a wide range of needs in accelerator technology to feed a wide range of loads from the low power magnetrons to powerful klystrons. Each modulator of the series is built on base of a number of unified solid-state modules connected to the pulse transformer, and covers a wide range of modulators: voltage up to 250 kV, a peak current up to 250 A, average power up to 100 kW and the pulse duration up to 20 μsec. The parameters of the block with an overall dimensions 880×540×250 mm are: voltage 12 kV, peak current 1600 A, pulse duration 20 μsec, average power 10 kW with air-cooling and 40 kW with liquidcooling. These parameters do not represent a physical limit, and modulators to parameters outside these ranges can be created on request.

  7. Solid waste treatment volume reduction by compaction or incineration

    International Nuclear Information System (INIS)

    Vigreux, B.; Carpentier, S.

    1985-01-01

    A short presentation is made of various techniques available for volume reduction by compaction of solid waste produced during nuclear plant operation. A long industrial experience has been accumulated in France on such compactors. Incineration is the most performing method of volume reduction for combustible waste. The CEA Group and SGN have developed a very reliable, simple and safe incinerator which operates with excess air and at high temperature. Sorting and feeding of the waste, ash discharge and transportation to the conditioning unit, gas treatment, are included in the system. The adding of a programmable controller makes it fully automated. The system is described with some detail and recent performance measurements are given [fr

  8. Solid waste treatment volume reduction by compaction or incineration

    International Nuclear Information System (INIS)

    Vigreux, B.; Carpentier, S.

    1986-01-01

    A short presentation is made of various techniques available for volume reduction by compaction of solid waste produced during nuclear plant operation. A long industrial experience has been accumulated in France on such compactors. Incineration is the most performing method of volume reduction for combustible waste. The CEA Group and SGN have developed a very reliable, simple and safe incinerator which operates with excess air and at high temperature. Sorting and feeding of the waste, ash discharge and transportation to the conditioning unit, gas treatment, are included in the system. The adding of a programmable controller makes it fully automated. The system is described with some detail and recent performance measurements are given [fr

  9. Fundamentals of ion-solid interaction. A compact introduction

    International Nuclear Information System (INIS)

    Moeller, Wolfhard

    2017-01-01

    interatomic potentials as of 1972. An early lecture series by Sigmund gives an overview of transport theory for ion ranges, radiation damage and sputtering. More recent books by the same author review energy loss theory. Sputtering and related phenomena are extensively covered in a series of books edited by Behrisch et al. A textbook by Eckstein focuses on the computer simulation of particle irradiation phenomena. This issue is also particularly addressed in a book edited by Smith. A compact and comprehensive overview of most aspects of ion-solid interaction and their applications has been written by Nastasi et al. A recent collection of expert contributions edited by Sigmund addresses in particular modern aspects of ion-surface interaction, such as involving very high ion energies with applications in biomedicine, and the ion-induced formation and control of nanostructures. For new topics of recent interest, a volume edited by Bernas is also recommended. In view of this broad and well-collected information, it cannot be the purpose of the present report to re-formulate the general fundamentals of ion-solid interactions or any special aspects in detail. In the context of the present short introduction, it is rather intended to provide a compact display of the essential knowledge which is valuable for any user of fast ion methods and technologies, for a convenient application of the most suitable formalisms and/or computer assistance. The present report has been derived from a lecture given at Technische Universitat Dresden and is based on textbook knowledge, individual publications and own work by the author before the year 2012. It concentrates on collisional fundamentals, addressing only short-time phenomena during the slowing down of the incident ions and the generated fast atoms of the target material, whereas thermal and chemical effects acting on longer time scales, such as postirradiation diffusion and phase formation, are not included. Further, the manifold materials

  10. Fundamentals of ion-solid interaction. A compact introduction

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, Wolfhard [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany). Inst. of Ion Beam Physics and Materials Research

    2017-09-01

    about interatomic potentials as of 1972. An early lecture series by Sigmund gives an overview of transport theory for ion ranges, radiation damage and sputtering. More recent books by the same author review energy loss theory. Sputtering and related phenomena are extensively covered in a series of books edited by Behrisch et al. A textbook by Eckstein focuses on the computer simulation of particle irradiation phenomena. This issue is also particularly addressed in a book edited by Smith. A compact and comprehensive overview of most aspects of ion-solid interaction and their applications has been written by Nastasi et al. A recent collection of expert contributions edited by Sigmund addresses in particular modern aspects of ion-surface interaction, such as involving very high ion energies with applications in biomedicine, and the ion-induced formation and control of nanostructures. For new topics of recent interest, a volume edited by Bernas is also recommended. In view of this broad and well-collected information, it cannot be the purpose of the present report to re-formulate the general fundamentals of ion-solid interactions or any special aspects in detail. In the context of the present short introduction, it is rather intended to provide a compact display of the essential knowledge which is valuable for any user of fast ion methods and technologies, for a convenient application of the most suitable formalisms and/or computer assistance. The present report has been derived from a lecture given at Technische Universitat Dresden and is based on textbook knowledge, individual publications and own work by the author before the year 2012. It concentrates on collisional fundamentals, addressing only short-time phenomena during the slowing down of the incident ions and the generated fast atoms of the target material, whereas thermal and chemical effects acting on longer time scales, such as postirradiation diffusion and phase formation, are not included. Further, the

  11. A compact, all solid-state LC high voltage generator.

    Science.gov (United States)

    Fan, Xuliang; Liu, Jinliang

    2013-06-01

    LC generator is widely applied in the field of high voltage generation technology. A compact and all solid-state LC high voltage generator based on saturable pulse transformer is proposed in this paper. First, working principle of the generator is presented. Theoretical analysis and circuit simulation are used to verify the design of the generator. Experimental studies of the proposed LC generator with two-stage main energy storage capacitors are carried out. And the results show that the proposed LC generator operates as expected. When the isolation inductance is 27 μH, the output voltage is 1.9 times larger than the charging voltage on single capacitor. The multiplication of voltages is achieved. On the condition that the primary energy storage capacitor is charged to 857 V, the output voltage of the generator can reach to 59.5 kV. The step-up ratio is nearly 69. When self breakdown gas gap switch is used as main switch, the rise time of the voltage pulse on load resistor is 8.7 ns. It means that the series-wound inductance in the discharging circuit is very small in this system. This generator can be employed in two different applications.

  12. Compaction of solid wastes in countries without disposal facility: A prelude of future troubles

    International Nuclear Information System (INIS)

    Benitez-Navarro, J.C.; Salgado-Mojena, M.

    2002-01-01

    This paper is intended to launch a technical debate, which will lead up to simple recommendations on what to do with compactable solid wastes in countries without disposal facilities. The paper discusses the problems caused by some practical uncertainties in the long-term management of the radioactive solid wastes produced outside the nuclear fuel cycle, in countries belonging to Groups A, B and C. Compaction is the preferred volume reduction method. But the compacted solid wastes are very probably not in a suitable form for future disposal and would need to be processed again in the near future. (author)

  13. Inorganic mass spectrometry of solid samples

    International Nuclear Information System (INIS)

    Adams, F.; Vertes, A.

    1990-01-01

    In this review some recent developments in the field of inorganic mass spectrometry of solids are described with special emphasis on the actual state of understanding of the ionization processes. It concentrates on the common characteristics of methods such as spark source-, laser-, secondary ion-, inductively coupled plasma- and glow discharge mass spectrometry. (orig.)

  14. A compact permanent magnet cyclotrino for accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Young, A.T.; Clark, D.J.; Kunkel, W.B.; Leung, K.N.; Li, C.Y. [Lawrence Berkeley Lab., CA (United States)

    1995-02-01

    The authors describe the development of a new instrument for the detection of trace amounts of rare isotopes, a Cyclotron Mass Spectrometer (CMS). A compact low energy cyclotron optimized for high mass resolution has been designed and has been fabricated. The instrument has high sensitivity and is designed to measure carbon-14 at abundances of < 10{sup {minus}12}. A novel feature of the instrument is the use of permanent magnets to energize the iron poles of the cyclotron. The instrument uses axial injection, employing a spiral inflector. The instrument has been assembled and preliminary measurements of the magnetic field show that it has a uniformity on the order of 2 parts in 10{sup 4}.

  15. Development of a high-pressure compaction system for non-combustible solid waste

    International Nuclear Information System (INIS)

    Yogo, S.; Hata, T.; Torita, K.; Yamamoto, K.; Karita, Y.

    1989-01-01

    In recent years, nuclear power plants in Japan have been in search of a means to reduce the volume of non-combustible solid wastes and therefore the application of a high-pressure compaction system has been in demand. Most non-combustible solid wastes have been packed in 200-litre drums for storage and the situation requires a high-pressure compaction system designed exclusively for 200-litre drums. The authors have developed a high-pressure compaction system which compresses 200-litre drums filled with non-combustible solid wastes and packs them into new woo-litre drums efficiently. This paper reports the outline of this high-pressure compaction system and the results of the full-scale verification tests

  16. Rugged and compact mid-infrared solid-state laser for avionics applications

    CSIR Research Space (South Africa)

    Esser, MJD

    2009-11-01

    Full Text Available In order to demonstrate the feasibility of a helicopter-based application using advanced laser technology, the authors have developed a rugged and compact mid-infrared solid-state laser. The requirement for the laser was to simultaneously emit at 2...

  17. Compact reformer for the solid polymer fuel cell policy and best

    Energy Technology Data Exchange (ETDEWEB)

    Goulding, P.S.; Deegan, M.; Gough, A. [Newcastle University (United Kingdom)

    1998-07-01

    This report summarises the results of a study investigating the feasibility of the Compact Reformer concept, and examining its design and manufacture. The development and testing of a hybrid reformer and thin coat catalyst systems are described, and details of the modeling of the reactor, and the optimisation and costing of the solid polymer fuel cell are given. (UK)

  18. Chemical imaging and solid state analysis at compact surfaces using UV imaging

    DEFF Research Database (Denmark)

    Wu, Jian X.; Rehder, Sönke; van den Berg, Frans

    2014-01-01

    and excipients in a non-invasive way, as well as mapping the glibenclamide solid state form. An exploratory data analysis supported the critical evaluation of the mapping results and the selection of model parameters for the chemical mapping. The present study demonstrated that the multi-wavelength UV imaging......Fast non-destructive multi-wavelength UV imaging together with multivariate image analysis was utilized to visualize distribution of chemical components and their solid state form at compact surfaces. Amorphous and crystalline solid forms of the antidiabetic compound glibenclamide...

  19. MRI of gynaecological solid masses pictorial review

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Yumiko Oishi; Nishida, Masato; Yamaguchi, Masayuki; Kohno, Keiko; Saida, Yukihisa; Itai, Yuji

    2000-12-01

    Differential diagnosis of gynaecological masses is sometimes difficult, as there are so many histological types. However, magnetic resonance characteristics of some gynaecological tumours have been reported past several years. On the basis of the recent literature, we have made a decision tree for differential diagnosis of solid gynaecological tumours, in which there are some important divergences. Bilateral disease and invasive growth are malignant signs in most cases. Specific findings for different tumour types include: fibrovascular septa in dysgermonimas; preserving ovarian follicles in round cell tumours; pseudolobular patterns in young patients in sclerosing stromal tumours; and extremely hypointense masses on T2WI in Brenner tumours. Distinguishing between sex-cord stromal tumours, Brenner tumours and metastatic tumours may be hard, however, especially in middle age, because they all tend to show well-demarcated, hypointense masses on T2WI. Disproportionately clear zonal anatomy of the uterus, enlarged uterus and thickened endometrium, which are indirect findings of oestrogen-producing tumours, are useful diagnostic findings in children and postmenopausals. Tanaka, Y.O. (2000)

  20. Heat Melt Compaction as an Effective Treatment for Eliminating Microorganisms from Solid Waste

    Science.gov (United States)

    Hummerick, Mary P.; Strayer, Richard F.; McCoy, Lashelle E.; Richards, Jeffrey T.; Ruby, Anna Maria; Wheeler, Ray; Fisher, John

    2013-01-01

    One of the technologies being tested at NASA Ames Research Center (ARC) for the Advance Exploration Systems program and as part of the logistics and repurposing project is heat melt compaction (HMC) of solid waste. Reduces volume, removes water and renders a biologically stable and safe product. The HMC compacts and reduces the trash volume as much as 90o/o greater than the current manual compaction used by the crew.The project has three primary goals or tasks. 1. Microbiological analysis of HMC hardware surfaces before and after operation. 2. Microbiological and physical characterizations of heat melt tiles made from trash at different processing times and temperatures. 3. Long term storage and stability of HMC trash tiles or "Do the bugs grow back?"

  1. A compact 500 MHz 4 kW Solid-State Power Amplifier for accelerator applications

    Energy Technology Data Exchange (ETDEWEB)

    Gaspar, M., E-mail: marcos.gaspar@psi.c [Paul Scherrer Institute, CH 5232 Villigen PSI (Switzerland); Pedrozzi, M. [Paul Scherrer Institute, CH 5232 Villigen PSI (Switzerland); Ferreira, L.F.R. [Department of Physics, University of Coimbra, 3004-516 Coimbra (Portugal); Garvey, T. [Paul Scherrer Institute, CH 5232 Villigen PSI (Switzerland)

    2011-05-01

    We present the development of a compact narrow-band Solid-State Power Amplifier (SSPA). We foresee a promising application of solid-state amplifiers specifically in accelerators for new generation synchrotron light sources. Such a new technology has reached a competitive price/performance ratio and expected lifetime in comparison with klystron and IOT amplifiers. The increasing number of synchrotron light sources using 500 MHz as base frequency justifies the effort in the development of the proposed amplifier. Two different techniques are also proposed to improve the control and performance of these new distributed amplification systems which we call, respectively, complete distributed system and forced compression.

  2. A compact 500 MHz 4 kW Solid-State Power Amplifier for accelerator applications

    International Nuclear Information System (INIS)

    Gaspar, M.; Pedrozzi, M.; Ferreira, L.F.R.; Garvey, T.

    2011-01-01

    We present the development of a compact narrow-band Solid-State Power Amplifier (SSPA). We foresee a promising application of solid-state amplifiers specifically in accelerators for new generation synchrotron light sources. Such a new technology has reached a competitive price/performance ratio and expected lifetime in comparison with klystron and IOT amplifiers. The increasing number of synchrotron light sources using 500 MHz as base frequency justifies the effort in the development of the proposed amplifier. Two different techniques are also proposed to improve the control and performance of these new distributed amplification systems which we call, respectively, complete distributed system and forced compression.

  3. Heat Melt Compaction as an Effective Treatment for Eliminating Microorganisms from Solid Waste

    Science.gov (United States)

    Hummerick, Mary P.; Strayer, Richard F.; McCoy, Lashelle E.; Richards, Jeffrey T.; Ruby, Anna Maria; Wheeler, Ray; Fisher, John

    2013-01-01

    One of the technologies being tested at Ames Research Center as part of the logistics and repurposing project is heat melt compaction (HMC) of solid waste to reduce volume, remove water and render a biologically stable and safe product. Studies at Kennedy Space Center have focused on the efficacy of the heat melt compaction process for killing microorganisms in waste and specific compacter operation protocols, i.e., time and temperature required to achieve a sterile, stable product. The work. reported here includes a controlled study to examine the survival and potential re-growth of specific microorganisms over a 6-month period of storage after heating and compaction. Before heating and compaction, ersatz solid wastes were inoculated with Bacillus amyloliquefaciens and Rhodotorula mucilaginosa, previously isolated from recovered space shuttle mission food and packaging waste. Compacted HMC tiles were sampled for microbiological analysis at time points between 0 and 180 days of storage in a controlled environment chamber. In addition, biological indicator strips containing spores of Bacillus atrophaeus and Geobacillus stearothermophilus were imbedded in trash to assess the efficacy of the HMC process to achieve sterilization. Analysis of several tiles compacted at 180deg C for times of 40 minutes to over 2 hours detected organisms in all tile samples with the exception of one exposed to 180deg C for approximately 2 hours. Neither of the inoculated organisms was recovered, and the biological indicator strips were negative for growth in all tiles indicating at least local sterilization of tile areas. The findings suggest that minimum time/temperature combination is required for complete sterilization. Microbial analysis of tiles processed at lower temperatures from 130deg C-150deg C at varying times will be discussed, as well as analysis of the bacteria and fungi present on the compactor hardware as a result of exposure to the waste and the surrounding environment

  4. A Tunable Mid-Infrared Solid-State Laser with a Compact Thermal Control System

    Directory of Open Access Journals (Sweden)

    Deyang Yu

    2018-05-01

    Full Text Available Tunable mid-infrared lasers are widely used in laser spectroscopy, gas sensing and many other related areas. In order to solve heat dissipation problems and improve the environmental temperature adaptability of solid-state laser sources, a tunable all-fiber laser pumped optical parametric oscillator (OPO was established, and a compact thermal control system based on thermoelectric coolers, an automatic temperature control circuit, cooling fins, fans and heat pipes was integrated and designed for the laser. This system is compact, light and air-cooling which satisfies the demand for miniaturization of lasers. A mathematical model and method was established to estimate the cooling capacity of this thermal control system under different ambient environments. A finite-element model was built and simulated to analyze the thermal transfer process. Experiments in room and high temperature environments were carried out and showed that the substrate temperature of a pump module could be maintained at a stable value with controlled precision to 0.2 degrees, while the output power stability of the laser was within ±1%. The experimental results indicate that this compact air-cooling thermal control system could effectively solve the heat dissipation problem of mid-infrared solid-state lasers with a one hundred watts level pump module in room and high temperature environments.

  5. Compact stars with a small electric charge: the limiting radius to mass relation and the maximum mass for incompressible matter

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Jose P.S.; Lopes, Francisco J.; Quinta, Goncalo [Universidade de Lisboa, UL, Departamento de Fisica, Centro Multidisciplinar de Astrofisica, CENTRA, Instituto Superior Tecnico, IST, Lisbon (Portugal); Zanchin, Vilson T. [Universidade Federal do ABC, Centro de Ciencias Naturais e Humanas, Santo Andre, SP (Brazil)

    2015-02-01

    One of the stiffest equations of state for matter in a compact star is constant energy density and this generates the interior Schwarzschild radius to mass relation and the Misner maximum mass for relativistic compact stars. If dark matter populates the interior of stars, and this matter is supersymmetric or of some other type, some of it possessing a tiny electric charge, there is the possibility that highly compact stars can trap a small but non-negligible electric charge. In this case the radius to mass relation for such compact stars should get modifications. We use an analytical scheme to investigate the limiting radius to mass relation and the maximum mass of relativistic stars made of an incompressible fluid with a small electric charge. The investigation is carried out by using the hydrostatic equilibrium equation, i.e., the Tolman-Oppenheimer-Volkoff (TOV) equation, together with the other equations of structure, with the further hypothesis that the charge distribution is proportional to the energy density. The approach relies on Volkoff and Misner's method to solve the TOV equation. For zero charge one gets the interior Schwarzschild limit, and supposing incompressible boson or fermion matter with constituents with masses of the order of the neutron mass one finds that the maximum mass is the Misner mass. For a small electric charge, our analytical approximating scheme, valid in first order in the star's electric charge, shows that the maximum mass increases relatively to the uncharged case, whereas the minimum possible radius decreases, an expected effect since the new field is repulsive, aiding the pressure to sustain the star against gravitational collapse. (orig.)

  6. A compact time-of-flight mass spectrometer for ion source characterization

    International Nuclear Information System (INIS)

    Chen, L.; Wan, X.; Jin, D. Z.; Tan, X. H.; Huang, Z. X.; Tan, G. B.

    2015-01-01

    A compact time-of-flight mass spectrometer with overall dimension of about 413 × 250 × 414 mm based on orthogonal injection and angle reflection has been developed for ion source characterization. Configuration and principle of the time-of-flight mass spectrometer are introduced in this paper. The mass resolution is optimized to be about 1690 (FWHM), and the ion energy detection range is tested to be between about 3 and 163 eV with the help of electron impact ion source. High mass resolution and compact configuration make this spectrometer useful to provide a valuable diagnostic for ion spectra fundamental research and study the mass to charge composition of plasma with wide range of parameters

  7. A compact copper nuclear demagnetization cryostat and a search for superfluidity in solid 4He

    International Nuclear Information System (INIS)

    Haar, P.G. van de.

    1991-01-01

    The subject of this thesis is the theoretical and experimental study of matter at low temperatures, and the development of techniques to reach and measure these temperatures. A copper nuclear demagnetization cryostat was developed in order to reach low temperatures. This system distinguishes itself from other cryostats by its compact construction. The lowest temperature recorded by a pulsed Pt-NMR thermometer was 115 μK. This system was used to search for superfluidity in solid 4 He. Due to the large zero-point motion of the atoms, 4He remains liquid down to zero temperature; a pressure of 25.3 bar is needed to force the atoms in a lattice. Even in solid state, the 4 He atoms remain very mobile, changing lattice sites at a frequency of approximately 10 7 Hz. It is possible that solid 4 He contains vacancies at zero temperature. These zero point vacancies are expected to behave like a gas of bosons, and should Bose-condense at some temperature. From experiments the upper limit to the vacancy concentration is set of 4·10-5. (author). 217 refs.; 46 figs.; 2 tabs

  8. In situ grain fracture mechanics during uniaxial compaction of granular solids

    Science.gov (United States)

    Hurley, R. C.; Lind, J.; Pagan, D. C.; Akin, M. C.; Herbold, E. B.

    2018-03-01

    Grain fracture and crushing are known to influence the macroscopic mechanical behavior of granular materials and be influenced by factors such as grain composition, morphology, and microstructure. In this paper, we investigate grain fracture and crushing by combining synchrotron x-ray computed tomography and three-dimensional x-ray diffraction to study two granular samples undergoing uniaxial compaction. Our measurements provide details of grain kinematics, contacts, average intra-granular stresses, inter-particle forces, and intra-grain crystal and fracture plane orientations. Our analyses elucidate the complex nature of fracture and crushing, showing that: (1) the average stress states of grains prior to fracture vary widely in their relation to global and local trends; (2) fractured grains experience inter-particle forces and stored energies that are statistically higher than intact grains prior to fracture; (3) fracture plane orientations are primarily controlled by average intra-granular stress and contact fabric rather than the orientation of the crystal lattice; (4) the creation of new surfaces during fracture accounts for a very small portion of the energy dissipated during compaction; (5) mixing brittle and ductile grain materials alters the grain-scale fracture response. The results highlight an application of combined x-ray measurements for non-destructive in situ analysis of granular solids and provide details about grain fracture that have important implications for theory and modeling.

  9. Compact extended model for doppler broadening of neutron absorption resonances in solids

    International Nuclear Information System (INIS)

    Villanueva, A. J; Granada, J.R

    2009-01-01

    We present a simplified compact model for calculating Doppler broadening of neutron absorption resonances in an incoherent Debye solid. Our model extends the effective temperature gas model to cover the whole range of energies and temperatures, and reduces the information of the dynamical system to a minimum content compatible with a much better accuracy of the calculation. This model is thus capable of replacing the existing algorithm in standard codes for resonance cross sections preparation aimed at neutron and reactor physics calculations. The model is applied to the 238 U 6.671 eV effective broadened cross section. We also show how this model can be used for thermometry in an improved fashion compared to the effective temperature gas model. Experimental data of the same resonance at low and high temperatures are also shown and the performances of each model are put to the test on this basis. [es

  10. Selected Topics on Mass Transport in Gas-solid Interactions

    DEFF Research Database (Denmark)

    Somers, Marcel A.J.

    2004-01-01

    The present article is a short review containing examples of the role of mass transport in the solid state during gas-solid interactions. Examples are taken from the authors' research on the interaction of carbon and/or nitrogen with iron-based metals. Topics dealt with are diffusion-controlled d......The present article is a short review containing examples of the role of mass transport in the solid state during gas-solid interactions. Examples are taken from the authors' research on the interaction of carbon and/or nitrogen with iron-based metals. Topics dealt with are diffusion...... on the kinetics of phenomena in the solid state. Various experimental techniques were applied to investigate these phenomena; it is however beyond the scope of the present article to treat experimental conditions in detail. The interested reader is referred to the original work for in depth discussions...

  11. A new direction for dark matter research: intermediate-mass compact halo objects

    Energy Technology Data Exchange (ETDEWEB)

    Chapline, George F. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA (United States); Frampton, Paul H., E-mail: george.chapline@gmail.com, E-mail: paul.h.frampton@gmail.com [15 Summerheights, 29 Water Eaton Road, Oxford OX2 7PG (United Kingdom)

    2016-11-01

    The failure to find evidence for elementary particles that could serve as the constituents of dark matter brings to mind suggestions that dark matter might consist of massive compact objects (MACHOs). In particular, it has recently been argued that MACHOs with masses > 15 M {sub ⊙} may have been prolifically produced at the onset of the big bang. Although a variety of astrophysical signatures for primordial MACHOs with masses in this range have been discussed in the literature, we favor a strategy that uses the potential for magnification of stars outside our galaxy due to gravitational microlensing of these stars by MACHOs in the halo of our galaxy. We point out that the effect of the motion of the Earth on the shape of the micro-lensing brightening curves provides a promising approach to testing over the course of next several years the hypothesis that dark matter consists of massive compact objects.

  12. Compact mass flow meter based on a micro coriolis flow sensor

    NARCIS (Netherlands)

    Sparreboom, Wouter; van de Geest, Jan; Katerberg, Marcel; Postma, F.M.; Haneveld, J.; Groenesteijn, Jarno; Lammerink, Theodorus S.J.; Wiegerink, Remco J.; Lötters, Joost Conrad

    2013-01-01

    In this paper we demonstrate a compact ready-to-use micro Coriolis mass flow meter. The full scale flow is 1 g/h (for water at a pressure drop < 1 bar). It has a zero stability of 2 mg/h and an accuracy of 0.5% reading for both liquids and gases. The temperature drift between 10 and 50 °C is below 1

  13. Compact mass flow meter based on a micro Coriolis flow sensor

    NARCIS (Netherlands)

    Sparreboom, Wouter; Katerberg, M.R.; Lammerink, Theodorus S.J.; Postma, F.M.; Haneveld, J.; Groenesteijn, Jarno; Wiegerink, Remco J.; Lötters, Joost Conrad

    2012-01-01

    In this paper we present a compact ready-to-use micro Coriolis mass flow meter. The full scale flow is 2 g/h (for water at a pressure drop of 2 bar). It has a zero stability of 2 mg/h and an accuracy of 0.5% reading. The temperature drift between 10 and 50 ºC is below 1 mg/h/ºC. The meter is robust,

  14. Compact, diode-pumped, solid-state lasers for next generation defence and security sensors

    Science.gov (United States)

    Silver, M.; Lee, S. T.; Borthwick, A.; McRae, I.; Jackson, D.; Alexander, W.

    2015-06-01

    Low-cost semiconductor laser diode pump sources have made a dramatic impact in sectors such as advanced manufacturing. They are now disrupting other sectors, such as defence and security (D&S), where Thales UK is a manufacturer of sensor systems for application on land, sea, air and man portable. In this talk, we will first give an overview of the market trends and challenges in the D&S sector. Then we will illustrate how low cost pump diodes are enabling new directions in D&S sensors, by describing two diode pumped, solid- state laser products currently under development at Thales UK. The first is a new generation of Laser Target Designators (LTD) that are used to identify targets for the secure guiding of munitions. Current systems are bulky, expensive and require large battery packs to operate. The advent of low cost diode technology, merged with our novel solid-state laser design, has created a designator that will be the smallest, lowest cost, STANAG compatible laser designator on the market. The LTD delivers greater that 50mJ per pulse up to 20Hz, and has compact dimensions of 125×70×55mm. Secondly, we describe an ultra-compact, eye-safe, solid-state laser rangefinder (LRF) with reduced size, weight and power consumption compared to existing products. The LRF measures 100×55×34mm, weighs 200g, and can range to greater than 10km with a single laser shot and at a reprate of 1Hz. This also leverages off advances in laser pump diodes, but also utilises low cost, high reliability, packaging technology commonly found in the telecoms sector. As is common in the D&S sector, the products are designed to work in extreme environments, such as wide temperature range (-40 to +71°C) and high levels of shock and vibration. These disruptive products enable next- generation laser sensors such as rangefinders, target designators and active illuminated imagers.

  15. Contribution of High-Mass Black Holes to Mergers of Compact Binaries

    International Nuclear Information System (INIS)

    Bethe, H.A.; Brown, G.E.

    1999-01-01

    We consider the merging of compact binaries consisting of a high-mass black hole and a neutron star. From stellar evolutionary calculations that include mass loss, we estimate that a zero-age main sequence (ZAMS) mass of approx-gt 80 M circle-dot is necessary before a high-mass black hole can result from a massive O star progenitor. We first consider how Cyg X-1, with its measured orbital radius of ∼17 R circle-dot , might evolve. Although this radius is substantially less than the initial distance of two O stars, it is still so large that the resulting compact objects will merge only if an eccentricity close to unity results from a high kick velocity of the neutron star in the final supernova explosion. We estimate the probability of the necessary eccentricity to be ∼1%; i.e., 99% of the time the explosion of a Cyg X-1 endash type object will end as a binary of compact stars, which will not merge in Hubble time (unless the orbit is tightened in common envelope evolution, which we discuss later). Although we predict ∼7 massive binaries of Cyg X-1 type, we argue that only Cyg X-1 is narrow enough to be observed, and that only Cyg X-1 has an appreciable chance of merging in Hubble time. This gives us a merging rate of ∼3x10 -8 yr -1 in the galaxy, the order of magnitude of the merging rate found by computer-driven population syntheses, if extrapolated to our mass limit of 80 M circle-dot ZAMS mass for high-mass black hole formation. Furthermore, in both our calculation and in those of population syntheses, almost all of the mergings involve an eccentricity close to unity in the final explosion of the O star. From this first part of our development we obtain only a negligible contribution to our final results for mergers, and it turns out to be irrelevant for our final results. In our main development, instead of relying on observed binaries, we consider the general evolution of binaries of massive stars. The critical stage is when the more massive star A has

  16. A compact E × B filter: A multi-collector cycloidal focusing mass spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Blase, Ryan C., E-mail: rblase@swri.edu; Miller, Greg; Brockwell, Tim; Waite, J. Hunter [Southwest Research Institute, 6220 Culebra Road, San Antonio, Texas 78238 (United States); Westlake, Joseph [The Johns Hopkins University Applied Physics Laboratory LLC, 11100 Johns Hopkins Road, Laurel, Maryland 20723 (United States); Ostrom, Nathaniel; Ostrom, Peggy H. [Department of Integrative Biology, Michigan State University, 288 Farm Lane RM 203, East Lansing, Michigan 48824 (United States)

    2015-10-15

    A compact E × B mass spectrometer is presented. The mass spectrometer presented is termed a “perfect focus” mass spectrometer as the resolution of the device is independent of both the initial direction and energy of the ions (spatial and energy independent). The mass spectrometer is small in size (∼10.7 in.{sup 3}) and weight (∼2 kg), making it an attractive candidate for portability when using small, permanent magnets. A multi-collector Faraday cup design allows for the detection of multiple ion beams in discrete collectors simultaneously; providing the opportunity for isotope ratio monitoring. The mass resolution of the device is around 400 through narrow collector slits and the sensitivity of the device follows expected theoretical calculations of the ion current produced in the electron impact ion source. Example mass spectra obtained from the cycloidal focusing mass spectrometer are presented as well as information on mass discrimination based on instrumental parameters and isotope ratio monitoring of certain ion signals in separate Faraday cups.

  17. A new compact solid-state neutral particle analyser at ASDEX Upgrade: Setup and physics modeling

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, P. A.; Blank, H.; Geiger, B.; Mank, K.; Martinov, S.; Ryter, F.; Weiland, M.; Weller, A. [Max-Planck-Institut für Plasmaphysik, Garching (Germany)

    2015-07-15

    At ASDEX Upgrade (AUG), a new compact solid-state detector has been installed to measure the energy spectrum of fast neutrals based on the principle described by Shinohara et al. [Rev. Sci. Instrum. 75, 3640 (2004)]. The diagnostic relies on the usual charge exchange of supra-thermal fast-ions with neutrals in the plasma. Therefore, the measured energy spectra directly correspond to those of confined fast-ions with a pitch angle defined by the line of sight of the detector. Experiments in AUG showed the good signal to noise characteristics of the detector. It is energy calibrated and can measure energies of 40-200 keV with count rates of up to 140 kcps. The detector has an active view on one of the heating beams. The heating beam increases the neutral density locally; thereby, information about the central fast-ion velocity distribution is obtained. The measured fluxes are modeled with a newly developed module for the 3D Monte Carlo code F90FIDASIM [Geiger et al., Plasma Phys. Controlled Fusion 53, 65010 (2011)]. The modeling allows to distinguish between the active (beam) and passive contributions to the signal. Thereby, the birth profile of the measured fast neutrals can be reconstructed. This model reproduces the measured energy spectra with good accuracy when the passive contribution is taken into account.

  18. 2D heat and mass transfer modeling of methane steam reforming for hydrogen production in a compact reformer

    International Nuclear Information System (INIS)

    Ni Meng

    2013-01-01

    Highlights: ► A heat and mass transfer model is developed for a compact reformer. ► Hydrogen production from methane steam reforming is simulated. ► Increasing temperature greatly increases the reaction rates at the inlet. ► Temperature in the downstream is increased at higher rate of heat supply. ► Larger permeability enhances gas flow and reaction rates in the catalyst layer. - Abstract: Compact reformers (CRs) are promising devices for efficient fuel processing. In CRs, a thin solid plate is sandwiched between two catalyst layers to enable efficient heat transfer from combustion duct to the reforming duct for fuel processing. In this study, a 2D heat and mass transfer model is developed to investigate the fundamental transport phenomenon and chemical reaction kinetics in a CR for hydrogen production by methane steam reforming (MSR). Both MSR reaction and water gas shift reaction (WGSR) are considered in the numerical model. Parametric simulations are performed to examine the effects of various structural/operating parameters, such as pore size, permeability, gas velocity, temperature, and rate of heat supply on the reformer performance. It is found that the reaction rates of MSR and WGSR are the highest at the inlet but decrease significantly along the reformer. Increasing the operating temperature raises the reaction rates at the inlet but shows very small influence in the downstream. For comparison, increasing the rate of heat supply raises the reaction rates in the downstream due to increased temperature. A high gas velocity and permeability facilitates gas transport in the porous structure thus enhances reaction rates in the downstream of the reformer.

  19. Heat and mass transfer involving droplets containing soluble solids

    International Nuclear Information System (INIS)

    Oscarson, J.L.; Briggs, D.E.

    1977-01-01

    The mass loss and temperature history of aqueous drops containing dissolved solids were measured under varying conditions of air velocity and temperature. The data taken from these drops were compared with the computer solution to a diffusional model. Very good agreement was obtained

  20. Compact Starburst Galaxies with Fast Outflows: Spatially Resolved Stellar Mass Profiles

    Science.gov (United States)

    Gottlieb, Sophia; Diamond-Stanic, Aleksandar; Lipscomb, Charles; Ohene, Senyo; Rines, Josh; Moustakas, John; Sell, Paul; Tremonti, Christy; Coil, Alison; Rudnick, Gregory; Hickox, Ryan C.; Geach, James; Kepley, Amanda

    2018-01-01

    Powerful galactic winds driven by stellar feedback and black hole accretion are thought to play an important role in regulating star formation in galaxies. In particular, strong stellar feedback from supernovae, stellar winds, radiation pressure, and cosmic rays is required by simulations of star-forming galaxies to prevent the vast majority of baryons from cooling and collapsing to form stars. However, it remains unclear whether these stellar processes play a significant role in expelling gas and shutting down star formation in massive progenitors of quiescent galaxies. What are the limits of stellar feedback? We present multi-band photometry with HST/WFC3 (F475W, F814W, F160W) for a dozen compact starburst galaxies at z~0.6 with half-light radii that suggest incredibly large central escape velocities. These massive galaxies are driving fast (>1000 km/s) outflows that have been previously attributed to stellar feedback associated with the compact (r~100 pc) starburst. But how compact is the stellar mass? In the context of the stellar feedback hypothesis, it is unclear whether these fast outflows are being driven at velocities comparable to the escape velocity of an incredibly dense stellar system (as predicted by some models of radiation-pressure winds) or at velocities that exceed the central escape velocity by large factor. Our spatially resolved measurements with HST show that the stellar mass is more extended than the light, and this requires that the physical mechanism responsible for driving the winds must be able to launch gas at velocities that are factors of 5-10 beyond the central escape velocity.

  1. Maximum mass ratio of AM CVn-type binary systems and maximum white dwarf mass in ultra-compact X-ray binaries

    Directory of Open Access Journals (Sweden)

    Arbutina Bojan

    2011-01-01

    Full Text Available AM CVn-type stars and ultra-compact X-ray binaries are extremely interesting semi-detached close binary systems in which the Roche lobe filling component is a white dwarf transferring mass to another white dwarf, neutron star or a black hole. Earlier theoretical considerations show that there is a maximum mass ratio of AM CVn-type binary systems (qmax ≈ 2/3 below which the mass transfer is stable. In this paper we derive slightly different value for qmax and more interestingly, by applying the same procedure, we find the maximum expected white dwarf mass in ultra-compact X-ray binaries.

  2. Compact Mass Flow Meter Based on a Micro Coriolis Flow Sensor

    Directory of Open Access Journals (Sweden)

    Remco Wiegerink

    2013-03-01

    Full Text Available In this paper we demonstrate a compact ready-to-use micro Coriolis mass flow meter. The full scale flow is 1 g/h (for water at a pressure drop < 1 bar. It has a zero stability of 2 mg/h and an accuracy of 0.5% reading for both liquids and gases. The temperature drift between 10 and 50 °C is below 1 mg/h/°C. The meter is robust, has standard fluidic connections and can be read out by means of a PC or laptop via USB. Its performance was tested for several common gases (hydrogen, helium, nitrogen, argon and air and liquids (water and isopropanol. As in all Coriolis mass flow meters, the meter is also able to measure the actual density of the medium flowing through the tube. The sensitivity of the measured density is ~1 Hz.m3/kg.

  3. A novel compact mass detection platform for the open access (OA) environment in drug discovery and early development.

    Science.gov (United States)

    Gao, Junling; Ceglia, Scott S; Jones, Michael D; Simeone, Jennifer; Antwerp, John Van; Zhang, Li-Kang; Ross, Charles W; Helmy, Roy

    2016-04-15

    A new 'compact mass detector' co-developed with an instrument manufacturer (Waters Corporation) as an interface for liquid chromatography (LC), specifically Ultra-high performance LC(®) (UPLC(®) or UHPLC) analysis was evaluated as a potential new Open Access (OA) LC-MS platform in the Drug Discovery and Early Development space. This new compact mass detector based platform was envisioned to provide increased reliability and speed while exhibiting significant cost, noise, and footprint reductions. The new detector was evaluated in batch mode (typically 1-3 samples per run) to monitor reactions and check purity, as well as in High Throughput Screening (HTS) mode to run 24, 48, and 96 well plates. The latter workflows focused on screening catalysis conditions, process optimization, and library work. The objective of this investigation was to assess the performance, reliability, and flexibility of the compact mass detector in the OA setting for a variety of applications. The compact mass detector results were compared to those obtained by current OA LC-MS systems, and the capabilities and benefits of the compact mass detector in the open access setting for chemists in the drug discovery and development space are demonstrated. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Construction, characterization and applications of a compact mass-resolved low-energy ion beam system

    International Nuclear Information System (INIS)

    Lau, W.M.; Feng, X.; Bello, I.; Sant, S.; Foo, K.K.; Lawson, R.P.W.

    1991-01-01

    A compact mass-resolved low-energy ion beam system has been constructed in which ions are extracted from a Colutron ion source, focused by an einzel lens, mass-selected by a Wien filter, refocused by a second einzel lens into an ultrahigh vacuum target chamber, and finally decelerated with a five-electrode lens. The design of the deceleration lens was assisted by computer simulation including space-charge effects with an ion trajectory software (CHDEN). The system performance has been characterized with a quadrupole mass spectrometer and an energy analyzer along the beam axis. For example, argon ions can be transported at keV and decelerated to 10 eV with an energy spread of ±0.5 eV. The total current measured by a Faraday cage at the exit of the deceleration lens in the energy range of 10-200 eV is about 1-5 μA. The ion current density was higher than 100 μA/cm 2 at 50 eV but decreased to 10-20 μA/cm 2 at 10 eV. The mass resolution was estimated to be 40 under the present operation configuration. The system has been used to produce interesting results in both ion beam etching and deposition. (orig.)

  5. New Physics Search in Dijet Mass Spectrum with Compact Muon Solenoid

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Chiyoung [Texas Tech Univ., Lubbock, TX (United States)

    2011-01-01

    Many extensions of the SM predict the existence of new massive objects that couple to quarks and gluons and result in resonances in the dijet mass spectrum. In this thesis we present a search for narrow resonances in the dijet mass spectrum using data corresponding to an integrated luminosity of 1 fb$^{-1}$ collected by the CMS experiment at the LHC, at a proton-proton collision energy of $\\sqrt{s}=7$ $TeV$. %This dijet analysis is searching for new particles in the dijet mass spectrum decaying to dijets. These new particles are predicted by new physics beyond Standard Model. This thesis presents a dijet analysis performed at the Compact Muon Solenoid (CMS) in pp collisions at $\\sqrt{s}=7$ $TeV$ for an integrated luminosities of 1.0 fb$^{-1}$. The dijet mass distribution of two leading jets is measured and compared to QCD predictions, simulated by PYTHIA with the CMS detector simulation. We select events which have two leading jets with $\\mid \\Delta\\eta \\mid < 1.3$ and $\\mid \\eta \\mid < 2.5$. We fit the dijet mass spectrum with QCD parameters. Since no evidence of new physics was found, we set upper limits at 95\\% CL on the resonance cross section and compare to the theoretical prediction for several models of new particles: string resonances, axigluons, colorons, excited quarks, $E_{6}$ diquarks, Randall-Sundrum gravitons, W' and Z'. We exclude at 95\\% CL string resonances in the mass range $1.0 < M(S) < 4.00$ TeV, excited quarks in the mass range $1.0mass range $1.0mass range $1.0mass range $1.0

  6. Solid lubricant mass contact transfer technology usage for vacuum ball bearings longevity increasing

    Science.gov (United States)

    Arzymatov, B.; Deulin, E.

    2016-07-01

    A contact mass transfer technological method of solid lubricant deposition on components of vacuum ball bearings is presented. Physics-mathematical model of process contact mass transfer is being considered. The experimental results of ball bearings covered with solid lubricant longevity in vacuum are presented. It is shown that solid lubricant of contact mass transfer method deposition is prospective for ball bearing longevity increasing.

  7. Smearing of mass accretion rate variation by viscous processes in accretion disks in compact binary systems

    Science.gov (United States)

    Ghosh, A.; Chakrabarti, Sandip K.

    2016-09-01

    Variation of mass supply rate from the companion can be smeared out by viscous processes inside an accretion disk. Hence, by the time the flow reaches the inner edge, the variation in X-rays need not reflect the true variation of the mass supply rate at the outer edge. However, if the viscosity fluctuates around a mean value, one would expect the viscous time scale t_{{visc}} also to spread around a mean value. In high mass X-ray binaries, which are thought to be primarily wind-fed, the size of the viscous Keplerian disk is smaller and thus such a spread could be lower as compared to the low mass X-ray binaries which are primarily fed by Roche lobe overflow. If there is an increasing or decreasing trend in viscosity, the interval between enhanced emission would be modified systematically. In the absence of a detailed knowledge about the variation of mass supply rates at the outer edge, we study ideal circumstances where modulation must take place exactly in orbital time scales, such as when there is an ellipticity in the orbit. We study a few compact binaries using long term All Sky monitor (ASM) data (1.5-12 keV) of Rossi X-ray Timing Explorer (RXTE) and all sky survey data (15-50 keV) of Swift satellites by different methods to look for such smearing effects and to infer what these results can tell us about the viscous processes inside the respective disks. We employ three different methods to seek imprints of periodicity on the X-ray variation and found that in all the cases, the location of the peak in the power density spectra is consistent with the orbital frequencies. Interestingly, in high mass X-ray binaries the peaks are sharp with high rms values, consistent with a small Keplerian disk in a wind fed system. However, in low mass X-ray binaries with larger Keplerian disk component, the peaks are spreaded out with much lower rms values. X-ray reflections, or superhump phenomena which may also cause such X-ray modulations would not be affected by the size of

  8. High-mass twins & resolution of the reconfinement, masquerade and hyperon puzzles of compact star interiors

    International Nuclear Information System (INIS)

    Blaschke, David; Alvarez-Castillo, David E.

    2016-01-01

    We aim at contributing to the resolution of three of the fundamental puzzles related to the still unsolved problem of the structure of the dense core of compact stars (CS): (i) the hyperon puzzle: how to reconcile pulsar masses of 2 M ⊙ with the hyperon softening of the equation of state (EoS); (ii) the masquerade problem: modern EoS for cold, high density hadronic and quark matter are almost identical; and (iii) the reconfinement puzzle: what to do when after a deconfinement transition the hadronic EoS becomes favorable again? We show that taking into account the compositeness of baryons (by excluded volume and/or quark Pauli blocking) on the hadronic side and confining and stiffening effects on the quark matter side results in an early phase transition to quark matter with sufficient stiffening at high densities which removes all three present-day puzzles of CS interiors. Moreover, in this new class of EoS for hybrid CS falls the interesting case of a strong first order phase transition which results in the observable high mass twin star phenomenon, an astrophysical observation of a critical endpoint in the QCD phase diagram

  9. The scenario of two families of compact stars. Pt. 1. Equations of state, mass-radius relations and binary systems

    Energy Technology Data Exchange (ETDEWEB)

    Drago, Alessandro; Pagliara, Giuseppe [Ferrara Univ. (Italy). Dipt. di Fisica e Scienze della Terra; INFN, Ferrara (Italy); Lavagno, Andrea; Pigato, Daniele [Politecnico di Torino (Italy). Dept. of Applied Science and Technology; INFN, Torino (Italy)

    2016-02-15

    We present several arguments which favor the scenario of two coexisting families of compact stars: hadronic stars and quark stars. Besides the well-known hyperon puzzle of the physics of compact stars, a similar puzzle exists also when considering delta resonances. We show that these particles appear at densities close to twice saturation density and must be therefore included in the calculations of the hadronic equation of state. Such an early appearance is strictly related to the value of the L parameter of the symmetry energy that has been found, in recent phenomenological studies, to lie in the range 40 < L < 62 MeV. We discuss also the threshold for the formation of deltas and hyperons for hot and lepton-rich hadronic matter. Similarly to the case of hyperons, also delta resonances cause a softening of the equation of state, which makes it difficult to obtain massive hadronic stars. Quark stars, on the other hand, can reach masses up to 2.75M {sub CircleDot} as predicted by perturbative QCD calculations. We then discuss the observational constraints on the masses and the radii of compact stars. The tension between the precise measurements of high masses and the indications of the existence of very compact stellar objects (with radii of the order of 10 km) is relieved when assuming that very massive compact stars are quark stars and very compact stars are hadronic stars. Finally, we discuss recent interesting measurements of the eccentricities of the orbits of millisecond pulsars in low mass X-ray binaries. The high values of the eccentricities found in some cases could be explained by assuming that the hadronic star, initially present in the binary system, converts to a quark star due to the increase of its central density. (orig.)

  10. Ultrasonic detection of solid phase mass flow ratio of pneumatic conveying fly ash

    Science.gov (United States)

    Duan, Guang Bin; Pan, Hong Li; Wang, Yong; Liu, Zong Ming

    2014-04-01

    In this paper, ultrasonic attenuation detection and weight balance are adopted to evaluate the solid mass ratio in this paper. Fly ash is transported on the up extraction fluidization pneumatic conveying workbench. In the ultrasonic test. McClements model and Bouguer-Lambert-Beer law model were applied to formulate the ultrasonic attenuation properties of gas-solid flow, which can give the solid mass ratio. While in the method of weigh balance, the averaged mass addition per second can reveal the solids mass flow ratio. By contrast these two solid phase mass ratio detection methods, we can know, the relative error is less.

  11. Mass, energy and material balances of SRF production process. Part 3: solid recovered fuel produced from municipal solid waste.

    Science.gov (United States)

    Nasrullah, Muhammad; Vainikka, Pasi; Hannula, Janne; Hurme, Markku; Kärki, Janne

    2015-02-01

    This is the third and final part of the three-part article written to describe the mass, energy and material balances of the solid recovered fuel production process produced from various types of waste streams through mechanical treatment. This article focused the production of solid recovered fuel from municipal solid waste. The stream of municipal solid waste used here as an input waste material to produce solid recovered fuel is energy waste collected from households of municipality. This article presents the mass, energy and material balances of the solid recovered fuel production process. These balances are based on the proximate as well as the ultimate analysis and the composition determination of various streams of material produced in a solid recovered fuel production plant. All the process streams are sampled and treated according to CEN standard methods for solid recovered fuel. The results of the mass balance of the solid recovered fuel production process showed that 72% of the input waste material was recovered in the form of solid recovered fuel; 2.6% as ferrous metal, 0.4% as non-ferrous metal, 11% was sorted as rejects material, 12% as fine faction and 2% as heavy fraction. The energy balance of the solid recovered fuel production process showed that 86% of the total input energy content of input waste material was recovered in the form of solid recovered fuel. The remaining percentage (14%) of the input energy was split into the streams of reject material, fine fraction and heavy fraction. The material balances of this process showed that mass fraction of paper and cardboard, plastic (soft) and wood recovered in the solid recovered fuel stream was 88%, 85% and 90%, respectively, of their input mass. A high mass fraction of rubber material, plastic (PVC-plastic) and inert (stone/rock and glass particles) was found in the reject material stream. © The Author(s) 2014.

  12. Compact solid state radio frequency amplifiers in kW regime for ...

    Indian Academy of Sciences (India)

    RF amplifier; solid state amplifier; power combiner and divider; .... was designed using planar and coaxial transmission line baluns with minimum lumped variable ..... Cripps S C 1999 RF power amplifiers for wireless communication. Norwood: ...

  13. A Compact, Efficient Pyrolysis/Oxidation System for Solid Waste Resource Recovery in Space, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Both pyrolysis and oxidation steps have been considered as the key solid waste processing step for a Controlled Ecological Life Support System (CELSS). Pyrolysis is...

  14. Analysis of solids by spark-source mass spectrometry; Analyse des solides au spectrometre de masse a etincelles

    Energy Technology Data Exchange (ETDEWEB)

    Stefani, R; Desjardins, M; Brun, J C; Cornu, A; Bourguillot, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1965-07-01

    Spark source mass spectrometer MS7 has been designed to determine traces of impurities in solids without standards. An atlas of 12 000 lines, assembled in the Grenoble laboratory, allows a quick investigation of mass spectra, notwithstanding their complexity due to multiply charged and polyatomic darkening. Photometric measurements increase accuracy calibration curve is known for each photo-plate. Further, reproducibility is better, if random fluctuations of matrix line darkening are corrected. So far, in a concentration range of 0,01 to 1 000 ppm (atomic), reproducibility is approximately 20 per cent, but absolute value of results depends on 'sensitivity coefficients'. (authors) [French] Le spectrometre de masse a etincelles, de type MS7, est destine a l'analyse chimique de traces dans les solides, sans echantillons etalons. L'emploi de catalogues de 12 000 raies, elabores au laboratoire, permet un depouillement rapide des spectres, malgre leur complexite due aux ionisations multiples et aux associations d'atomes. Le niveau d'apparition d'une impurete donne une estimation de sa teneur, mais la valeur du renseignement depend de la preparation des electrodes et de la connaissance plus ou moins approfondie des processus d'ionisation dans l'etincelle et de noircissement des emulsions photographiques. Les mesures photometriques augmentent la precision des resultats, si l'on determine systematiquement la courbe de noircissement de chaque plaque. De meme la reproductibilite est amelioree si l'on tient compte des fluctuations statistiques du noircissement de l'emulsion par les ions de la matrice. Actuellement, les concentrations mesurees dans le domaine de 0,01 a 1000 ppm atomiques sont reproductibles a 20 pour cent pres, mais leur valeur absolue n'est assuree qu'a un coefficient 3 pres. Des etudes sont en cours pour calibrer l'appareil en valeur absolue, par une determination des coefficients de sensibilite a partir d'echantillons etalons. (auteurs)

  15. Primary and Reflected Compaction Waves in a Foam Rod Due to an Axial Impact by a Small Mass

    Directory of Open Access Journals (Sweden)

    D. Karagiozova

    Full Text Available AbstractThe propagation of compaction waves in a stationary foam block subjected to an impact by a small mass is studied in order to examine the mechanism of compaction within the primary and reflected stress waves. The analysis is focused on aluminium strain rate insensitive foam that exhibits strain hardening under quasistatic compression. A theoretical approach is applied using a uniaxial model of compaction in which the compacted strains, being functions of the velocity variation, are not predefined but are obtained as a part of the solution. The present approach allows one to obtain the strain histories and strain distributions within the primary compaction wave as well as within the reflected wave, which propagates in a media with non-uniform density increasing monotonically in the direction of loading. FE simulations considering aluminium based foam Cymat with density 411.5 kg/m3 are carried out in order to verify the proposed theoretical model. A comparison between the impact velocity attenuation predicted by the present model and classical Rigid Perfectly-Plastic Locking material model for cellular materials is discussed.

  16. A compact solid-state detector for small angle particle tracking

    Energy Technology Data Exchange (ETDEWEB)

    Altieri, S.; Barnaba, O.; Braghieri, A. E-mail: alessandro.braghieri@pv.infn.it; Cambiaghi, M.; Lanza, A.; Locatelli, T.; Panzeri, A.; Pedroni, P.; Pinelli, T.; Jennewein, P.; Lang, M.; Preobrazhensky, I.; Annand, J.R.M.; Sadiq, F

    2000-09-21

    MIcrostrip Detector Array System (MIDAS) is a compact silicon-tracking telescope for charged particles emitted at small angles in intermediate energy photonuclear reactions. It was realized to increase the angular acceptance of the DAPHNE detector and used in an experimental program to check the Gerasimov-Drell-Hearn sum rule at the Mainz electron microtron (MAMI). MIDAS provides a trigger for charged hadrons, p/{pi}{sup {+-}} identification and particle tracking in the region 7 deg. <{theta}<16 deg.. In this paper we present the main characteristics of MIDAS and its measured performances.

  17. A compact solid-state detector for small angle particle tracking

    International Nuclear Information System (INIS)

    Altieri, S.; Barnaba, O.; Braghieri, A.; Cambiaghi, M.; Lanza, A.; Locatelli, T.; Panzeri, A.; Pedroni, P.; Pinelli, T.; Jennewein, P.; Lang, M.; Preobrazhensky, I.; Annand, J.R.M.; Sadiq, F.

    2000-01-01

    MIcrostrip Detector Array System (MIDAS) is a compact silicon-tracking telescope for charged particles emitted at small angles in intermediate energy photonuclear reactions. It was realized to increase the angular acceptance of the DAPHNE detector and used in an experimental program to check the Gerasimov-Drell-Hearn sum rule at the Mainz electron microtron (MAMI). MIDAS provides a trigger for charged hadrons, p/π ± identification and particle tracking in the region 7 deg. <θ<16 deg.. In this paper we present the main characteristics of MIDAS and its measured performances

  18. Compact Solid-State 213 nm Laser Enables Standoff Deep Ultraviolet Raman Spectrometer: Measurements of Nitrate Photochemistry.

    Science.gov (United States)

    Bykov, Sergei V; Mao, Michael; Gares, Katie L; Asher, Sanford A

    2015-08-01

    We describe a new compact acousto-optically Q-switched diode-pumped solid-state (DPSS) intracavity frequency-tripled neodymium-doped yttrium vanadate laser capable of producing ~100 mW of 213 nm power quasi-continuous wave as 15 ns pulses at a 30 kHz repetition rate. We use this new laser in a prototype of a deep ultraviolet (UV) Raman standoff spectrometer. We use a novel high-throughput, high-resolution Echelle Raman spectrograph. We measure the deep UV resonance Raman (UVRR) spectra of solid and solution sodium nitrate (NaNO3) and ammonium nitrate (NH4NO3) at a standoff distance of ~2.2 m. For this 2.2 m standoff distance and a 1 min spectral accumulation time, where we only monitor the symmetric stretching band, we find a solid state NaNO3 detection limit of ~100 μg/cm(2). We easily detect ~20 μM nitrate water solutions in 1 cm path length cells. As expected, the aqueous solutions UVRR spectra of NaNO3 and NH4NO3 are similar, showing selective resonance enhancement of the nitrate (NO3(-)) vibrations. The aqueous solution photochemistry is also similar, showing facile conversion of NO3(-) to nitrite (NO2(-)). In contrast, the observed UVRR spectra of NaNO3 and NH4NO3 powders significantly differ, because their solid-state photochemistries differ. Whereas solid NaNO3 photoconverts with a very low quantum yield to NaNO2, the NH4NO3 degrades with an apparent quantum yield of ~0.2 to gaseous species.

  19. Can Walking or Biking to Work Really Make a Difference? Compact Development, Observed Commuter Choice and Body Mass Index.

    Science.gov (United States)

    Wojan, Timothy R; Hamrick, Karen S

    2015-01-01

    Promoting active commuting is viewed as one strategy to increase physical activity and improve the energy balance of more sedentary individuals thereby improving health outcomes. However, the potential effectiveness of promotion policies may be seriously undermined by the endogenous choice of commute mode. Policy to promote active commuting will be most effective if it can be demonstrated that 1) those in compact cities do not necessarily have a preference for more physical activity, and 2) that current active commuting is not explained by unobserved characteristics that may be the true source of a lower body mass index (BMI). Daily time-use diaries are used in combination with geographical characteristics of where respondents live and work to test 1) whether residents of more compact settlements are characterized by higher activity levels; and 2) whether residents of more compact settlements are more likely to bike or walk to work. An endogenous treatment model of active commuting allows testing whether reductions in BMI associated with walking or biking to work are in fact attributable to that activity or are more strongly associated with unobserved characteristics of these active commuters. The analysis of general activity levels confirms that residents of more compact cities do not expend more energy than residents of more sprawling cities, indicating that those in compact cities do not necessarily have a preference for more physical activity. The endogenous treatment model is consistent with walking or biking to work having an independent effect on BMI, as unobserved factors that contribute to a higher likelihood of active commuting are not associated with lower BMI. Despite evidence that more compact settlement patterns enable active commuting, only a small share of workers in these areas choose to walk or bike to work. In general, the activity level of residents in more compact cities and residents in more sprawling areas is very similar. But, there is a

  20. Can Walking or Biking to Work Really Make a Difference? Compact Development, Observed Commuter Choice and Body Mass Index.

    Directory of Open Access Journals (Sweden)

    Timothy R Wojan

    Full Text Available Promoting active commuting is viewed as one strategy to increase physical activity and improve the energy balance of more sedentary individuals thereby improving health outcomes. However, the potential effectiveness of promotion policies may be seriously undermined by the endogenous choice of commute mode. Policy to promote active commuting will be most effective if it can be demonstrated that 1 those in compact cities do not necessarily have a preference for more physical activity, and 2 that current active commuting is not explained by unobserved characteristics that may be the true source of a lower body mass index (BMI.Daily time-use diaries are used in combination with geographical characteristics of where respondents live and work to test 1 whether residents of more compact settlements are characterized by higher activity levels; and 2 whether residents of more compact settlements are more likely to bike or walk to work. An endogenous treatment model of active commuting allows testing whether reductions in BMI associated with walking or biking to work are in fact attributable to that activity or are more strongly associated with unobserved characteristics of these active commuters.The analysis of general activity levels confirms that residents of more compact cities do not expend more energy than residents of more sprawling cities, indicating that those in compact cities do not necessarily have a preference for more physical activity. The endogenous treatment model is consistent with walking or biking to work having an independent effect on BMI, as unobserved factors that contribute to a higher likelihood of active commuting are not associated with lower BMI.Despite evidence that more compact settlement patterns enable active commuting, only a small share of workers in these areas choose to walk or bike to work. In general, the activity level of residents in more compact cities and residents in more sprawling areas is very similar. But

  1. Search for gravitational waves from low mass compact binary coalescence in 186 days of LIGO's fifth science run

    International Nuclear Information System (INIS)

    Abbott, B. P.; Abbott, R.; Adhikari, R.; Anderson, S. B.; Araya, M.; Armandula, H.; Aso, Y.; Ballmer, S.; Barton, M. A.; Betzwieser, J.; Billingsley, G.; Black, E.; Blackburn, J. K.; Bork, R.; Boschi, V.; Brooks, A. F.; Cannon, K. C.; Cardenas, L.; Cepeda, C.; Chalermsongsak, T.

    2009-01-01

    We report on a search for gravitational waves from coalescing compact binaries, of total mass between 2 and 35M · , using LIGO observations between November 14, 2006 and May 18, 2007. No gravitational-wave signals were detected. We report upper limits on the rate of compact binary coalescence as a function of total mass. The LIGO cumulative 90%-confidence rate upper limits of the binary coalescence of neutron stars, black holes and black hole-neutron star systems are 1.4x10 -2 , 7.3x10 -4 and 3.6x10 -3 yr -1 L 10 -1 , respectively, where L 10 is 10 10 times the blue solar luminosity.

  2. Gravitational radiation emitted when a mass falls onto a compact star.

    Science.gov (United States)

    Borelli, A.

    1997-03-01

    The authors study the energy spectrum related to the axial perturbations of a compact star when a particle falls spiralling onto it. They find that both slowly-damped quasi-normal modes and strongly damped w-modes are excited, and that a part of the energy in the process is associated to these w-modes. A substantial difference between the energy spectra of compact stars and black holes is shown.

  3. Mass balance of the Greenland ice sheet - a study of ICESat data, surface density and firn compaction modelling

    DEFF Research Database (Denmark)

    Sørensen, L. S.; Simonsen, Sebastian Bjerregaard; Nielsen, K.

    2010-01-01

    ICESat has provided surface elevation measurements of the ice sheets since the launch in January 2003, resulting in a unique data set for monitoring the changes of the cryosphere. Here we present a novel method for determining the mass balance of the Greenland ice sheet derived from ICESat...... in estimating the mass balance of the Greenland ice sheet. We find firn dynamics and surface densities to be important factors in deriving the mass loss from remote sensing altimetry. The volume change derived from ICESat data is corrected for firn compaction, vertical bedrock movement and an intercampaign...... boundary conditions. We find an annual mass loss of the Greenland ice sheet of 210 ± 21 Gt yr-1 in the period from October 2003 to March 2008. This result is in good agreement with other studies of the Greenland ice sheet mass balance, based on different remote sensing techniques....

  4. Extra force and extra mass from non-compact Kaluza-Klein theory in a cosmological model

    International Nuclear Information System (INIS)

    MadrizAguilar, J.E.; Bellini, M.

    2005-01-01

    Using the Hamilton-Jacobi formalism, we study extra force and extra mass in a recently introduced non-compact Kaluza-Klein cosmological model. We examine the inertial 4D mass m 0 of the inflaton field on a 4D FRW bulk in two examples. We find that m 0 has a geometrical origin and antigravitational effects on a non-inertial 4D bulk should be a consequence of the motion of the fifth coordinate with respect to the 4D bulk. (orig.)

  5. Rotating solid foam reactors : mass transfer and reaction rate

    NARCIS (Netherlands)

    Tschentscher, R.

    2012-01-01

    In this thesis the performance and applicability of rotating solid foam stirrers is investigated. The stirrer consists, thereby of a solid, highly porous structure, which is used as stirrer and catalyst support simultaneously. The solid foam block occupies a large part of the reactor volume.

  6. Novel laterally pumped by prism laser configuration for compact solid-state lasers

    International Nuclear Information System (INIS)

    Dascalu, T; Salamu, G; Sandu, O; Voicu, F; Pavel, N

    2013-01-01

    We propose a new laser configuration in which the pump radiation is coupled into the laser crystal through a prism. The laser medium is square shaped and the prism is attached on one of its lateral sides, near one of the crystal extremities. The diode-laser fiber end is placed close to the prism hypotenuse, the pump radiation is coupled into the laser crystal through the opposite surface of the prism and propagates into the crystal through total internal reflections. This laser geometry is simple to align and permits the realization of compact diode-pumped laser systems, as well as power scaling. A diode-pumped Nd:YAG laser yielding pulses of 2.1 mJ energy under a pump with pulses of 9.9 mJ is demonstrated. The laser slope efficiency is 0.22. Furthermore, this geometry enables one to obtain passively Q-switched lasers with the saturable absorber crystal placed between the resonator high-reflectivity mirror and the laser crystal. A Nd:YAG laser, passively Q-switched by a Cr 4+ :YAG crystal with initial transmission T 0 = 0.90, delivering laser output with a pulsed energy of 93 μJ, a duration of 26 ns and a pump threshold of 1.9 mJ, is realized in order to prove the concept. (letter)

  7. Utility of compact ultrasound in a mass surgical selection program in Africa: experience of a sonologist at the MV Africa Mercy Hospital Ship's screening day.

    Science.gov (United States)

    Harris, Robert D; Parker, Gary

    2015-02-01

    Compact ultrasound (US) was introduced in an austere setting with no other available imaging for an annual mass surgical screening day. Compact US examinations were performed on 25 patients from more than 7000 potential patients, as deemed possibly useful by the screening surgeons. Of the 20 patients with recorded data, compact US was helpful in 14 of 20 as a decision-making tool, obviating computed tomography for preoperative planning. Compact US was helpful in most cases, saving resources (computed tomography), technologist time, and radiation risk in this select population. © 2015 by the American Institute of Ultrasound in Medicine.

  8. Ultra-trace determination of neptunium-237 and plutonium isotopes in urine samples by compact accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Dai, X.; Christl, M.; Kramer-Tremblay, S., E-mail: sheila.kramer-tremblay@cnl.ca [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada); Synal, H-A. [ETH Zurich, Lab. of Ion Beam Physics, Zurich (Switzerland)

    2015-12-15

    Ultra-trace analysis of actinides, such as Pu isotopes and {sup 237}Np, in bioassay samples is often needed for radiation protection programs at nuclear facilities. Accelerator mass spectrometry (AMS), particularly the compact ETH Zurich system “Tandy”, has evolved over the years as one of the most sensitive, selective, and robust techniques for actinide analysis. Employment of the AMS technique can reduce the demands on sample preparation chemistry and increase sample analysis throughput, due to very low instrumental detection limit, high rejection of interferences, and low susceptibility to adverse sample matrices. Initial research and development tests were performed to explore and demonstrate the analytical capability of AMS for Pu and Np urine bioassay. In this study, urine samples spiked with femtogram levels of Np and Pu isotopes were prepared and measured using compact ETH AMS system and the results showed excellent analytical capability for measuring Np and Pu isotopes at femtogram/litre levels in urine. (author)

  9. How elevated is the dynamical-to-stellar mass ratio of the ultra-compact dwarf S999?

    OpenAIRE

    Janz, Joachim; Forbes, Duncan A.; Norris, Mark A.; Strader, Jay; Penny, Samantha J.; Fagioli, Martina; Romanowsky, Aaron J.

    2015-01-01

    Here we present new Keck ESI high-resolution spectroscopy and deep archival HST/ACS imaging for S999, an ultra-compact dwarf in the vicinity of M87, which was claimed to have an extremely high dynamical-to-stellar mass ratio. Our data increase the total integration times by a factor of 5 and 60 for spectroscopy and imaging, respectively. This allows us to constrain the stellar population parameters for the first time (simple stellar population equivalent age $=7.6^{+2.0}_{-1.6}$ Gyr; $[Z/\\tex...

  10. Compact and multi-view solid state neutral particle analyzer arrays on National Spherical Torus Experiment-Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Liu, D., E-mail: deyongl@uci.edu; Heidbrink, W. W.; Hao, G. Z.; Zhu, Y. B. [Departments of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Tritz, K. [Departments of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Fredrickson, E. D. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2016-11-15

    A compact and multi-view solid state neutral particle analyzer (SSNPA) diagnostic based on silicon photodiode arrays has been successfully tested on the National Spherical Torus Experiment-Upgrade. The SSNPA diagnostic provides spatially, temporally, and pitch-angle resolved measurements of fast-ion distribution by detecting fast neutral flux resulting from the charge exchange (CX) reactions. The system consists of three 16-channel subsystems: t-SSNPA viewing the plasma mid-radius and neutral beam (NB) line #2 tangentially, r-SSNPA viewing the plasma core and NB line #1 radially, and p-SSNPA with no intersection with any NB lines. Due to the setup geometry, the active CX signals of t-SSNPA and r-SSNPA are mainly sensitive to passing and trapped particles, respectively. In addition, both t-SSNPA and r-SSNPA utilize three vertically stacked arrays with different filter thicknesses to obtain coarse energy information. The experimental data show that all channels are operational. The signal to noise ratio is typically larger than 10, and the main noise is x-ray induced signal. The active and passive CX signals are clearly observed on t-SSNPA and r-SSNPA during NB modulation. The SSNPA data also indicate significant losses of passing particles during sawteeth, while trapped particles are weakly affected. Fluctuations up to 120 kHz have been observed on SSNPA, and they are strongly correlated with magnetohydrodynamics instabilities.

  11. Third post-Newtonian dynamics of compact binaries: equations of motion in the centre-of-mass frame

    CERN Document Server

    Blanchet, L

    2003-01-01

    The equations of motion of compact binary systems and their associated Lagrangian formulation have been derived in previous works at the third post-Newtonian (3PN) approximation of general relativity in harmonic coordinates. In the present work, we investigate the binary's relative dynamics in the centre-of-mass frame (centre of mass located at the origin of the coordinates). We obtain the 3PN-accurate expressions of the centre-of-mass positions and equations of the relative binary motion. We show that the equations derive from a Lagrangian (neglecting the radiation reaction), from which we deduce the conserved centre-of-mass energy and angular momentum at the 3PN order. The harmonic-coordinates centre-of-mass Lagrangian is equivalent, via a contact transformation of the particles' variables, to the centre-of-mass Hamiltonian in ADM coordinates that is known from the post-Newtonian ADM-Hamiltonian formalism. As an application we investigate the dynamical stability of circular binary orbits at the 3PN order.

  12. Modelling of interactions between variable mass and density solid particles and swirling gas stream

    International Nuclear Information System (INIS)

    Wardach-Święcicka, I; Kardaś, D; Pozorski, J

    2011-01-01

    The aim of this work is to investigate the solid particles - gas interactions. For this purpose, numerical modelling was carried out by means of a commercial code for simulations of two-phase dispersed flows with the in-house models accounting for mass and density change of solid phase. In the studied case the particles are treated as spherical moving grains carried by a swirling stream of hot gases. Due to the heat and mass transfer between gas and solid phase, the particles are losing their mass and they are changing their volume. Numerical simulations were performed for turbulent regime, using two methods for turbulence modelling: RANS and LES.

  13. Mass transfer between gas and particles in a gas-solid trickle flow reactor

    NARCIS (Netherlands)

    Kiel, J.H.A.; Kiel, J.H.A.; Prins, W.; van Swaaij, Willibrordus Petrus Maria

    1992-01-01

    Gas-solids mass transfer was studied for counter-current flow of gas and millimetre-sized solid particles over an inert packing at dilute phase or trickle flow conditions. Experimental data were obtained from the adsorption of water vapour on 640 and 2200 ¿m diameter molecular sieve spheres at

  14. Solid foam packings for multiphase reactors: Modelling of liquid holdup and mass transfer

    NARCIS (Netherlands)

    Stemmet, C.P.; Schaaf, van der J.; Kuster, B.F.M.; Schouten, J.C.

    2006-01-01

    In this paper, experimental and modeling results are presented of the liquid holdup and gas–liquid mass transfer characteristics of solid foam packings. Experiments were done in a semi-2D transparent bubble column with solid foam packings of aluminum in the range of 5–40 pores per inch (ppi). The

  15. A cosmological model with compact space sections and low mass density

    International Nuclear Information System (INIS)

    Fagundes, H.V.

    1982-01-01

    A general relativistic cosmological model is presented, which has closed space sections and mass density below a critical density similar to that of Friedmann's models. The model may predict double images of cosmic sources. (Author) [pt

  16. Solid waste processing and compaction in the AD2 workshop of the new La Hague reprocessing plant

    International Nuclear Information System (INIS)

    Singer, B.M.; Vigreux, B.

    1987-01-01

    The AD2 workshop of the new spent nuclear fuel reprocessing plant at La Hague in France will process and package dry solid wastes. The waste packages will be segregated according to their activity levels and stored at temporary on-site facilities. Full commissioning is scheduled for end-1988. However, operation of the TO dry spent field unloading and receiving unit at La Hague required early availability of some waste processing functions and part of the AD2 workshop was commissioned towards the end of 1986. The new La Hague plant is organized into four main zones: - zone 1 is an uncontrolled area with no permanent contamination and zero risk of accidental contamination, - zone 2 is a controlled are with no permanent contamination and low risk of accidental minor contamination, - zone 3 is a controlled area with no permanent contamination but a risk of minor contamination due to various incidents, - zone 4 is a controlled area with permanent contamination. The AD2 workshop will handle all dry solid wastes from zones 2, 3 and 4. It will also: characterize the resulting waste packages (contents, mass, alpha, beta and gamma activity, dose equivalent rate) and check for absence of surface contamination; transfer the packages to temporary on-site storage facilities; store and administer mobile handling tasks and transporters

  17. Incidental solid renal mass in a cadaveric donor kidney

    Directory of Open Access Journals (Sweden)

    R M Meyyappan

    2012-01-01

    Full Text Available The number of patients living with end-stage renal disease (ESRD is increasing in our country and demand for renal grafts is ever increasing. Cadaver renal transplantation is being established as a viable supplement to live transplantation. We present a case where a mass lesion was encountered in the donor kidney from a cadaver. Enucleation of the lesion was done and we proceeded with the grafting. Histopathological examination showed a ′Renomedullary interstitial cell tumour′, a rare benign lesion. Post transplant, the renal function recovered well and the patient is asymptomatic. Such incidental renal masses present an ethical dilemma to the operating surgeon.

  18. Real-time monitoring of trace-level VOCs by an ultrasensitive compact lamp-based VUV photoionization mass spectrometer

    Science.gov (United States)

    Sun, W. Q.; Shu, J. N.; Zhang, P.; Li, Z.; Li, N. N.; Liang, M.; Yang, B.

    2015-06-01

    In this study, we report on the development of a compact lamp-based vacuum ultraviolet (VUV) photoionization mass spectrometer (PIMS; hereafter referred to as VUV-PIMS) in our laboratory; it is composed of a radio frequency-powered VUV lamp, a VUV photoionizer, an ion-immigration region, and a reflection time-of-flight mass spectrometer. By utilizing the novel photoionizer consisting of a photoionization cavity and a VUV light baffle, extremely low background noise was obtained. An ultrasensitive detection limit (2σ) of 3 pptv was achieved for benzene after an acquisition time of 10 s. To examine its potential for application in real-time sample monitoring, the developed VUV-PIMS was employed for the continuous measurement of urban air for six days in Beijing, China. Strong signals of trace-level volatile organic compounds such as benzene and its alkylated derivatives were observed in the mass spectra. These initial experimental results reveal that the instrument can be used for the online monitoring of trace-level species in the atmosphere.

  19. Mixture theory for a thermoelasto-plastic porous solid considering fluid flow and internal mass exchange

    DEFF Research Database (Denmark)

    Ristinmaa, M.; Ottosen, N.S.; Johannesson, Björn

    2011-01-01

    A thermoelastic-plastic body consisting of two phases, a solid and a fluid, each comprising two constituents is considered where one constituent in one phase is allowed to exchange mass with another constituent (of the same substance) in the other phase. A large strain setting is adopted and the ......A thermoelastic-plastic body consisting of two phases, a solid and a fluid, each comprising two constituents is considered where one constituent in one phase is allowed to exchange mass with another constituent (of the same substance) in the other phase. A large strain setting is adopted......, and in particular, a general evolution law for the rate of deformation tensor related to mass exchange is proposed and this leads to general absorption and desorption evolution laws for mass exchange between two constituents (of the same substance), one belonging to the solid phase and the other to the fluid phase....... Equilibrium curves for absorption and desorption also emerge from the theory....

  20. Performance report for the low energy compact radiocarbon accelerator mass spectrometer at Uppsala University

    Energy Technology Data Exchange (ETDEWEB)

    Salehpour, M., E-mail: mehran.salehpour@physics.uu.se [Department of Physics and Astronomy, Ion Physics, Applied Nuclear Physics Division, P.O. Box 516, SE-751 20 Uppsala (Sweden); Håkansson, K.; Possnert, G. [Department of Physics and Astronomy, Ion Physics, Applied Nuclear Physics Division, P.O. Box 516, SE-751 20 Uppsala (Sweden); Wacker, L.; Synal, H.-A. [Ion Physics, ETH Zurich, Otto-Stern-Weg 5, 8093 (Switzerland)

    2016-03-15

    A range of ion beam analysis activities are ongoing at Uppsala University, including Accelerator Mass Spectrometry (AMS). Various isotopes are used for AMS but the isotope with the widest variety of applications is radiocarbon. Up until recently, only the 5 MV Pelletron tandem accelerator had been used at our site for radiocarbon AMS, ordinarily using 12 MeV {sup 14,13,12}C{sup 3+} ions. Recently a new radiocarbon AMS system, the Green-MICADAS, developed at the ion physics group at ETH Zurich, was installed. The system has a number of outstanding features which will be described. The system operates at a terminal voltage of 175 kV and uses helium stripper gas, extracting singly charged carbon ions. The low- and high energy mass spectrometers in the system are stigmatic dipole permanent magnets (0.42 and 0.97 T) requiring no electrical power nor cooling water. The system measures both the {sup 14}C/{sup 12}C and the {sup 13}C/{sup 12}C ratios on-line. Performance of the system is presented for both standard mg samples as well as μg-sized samples.

  1. Performance report for the low energy compact radiocarbon accelerator mass spectrometer at Uppsala University

    Science.gov (United States)

    Salehpour, M.; Håkansson, K.; Possnert, G.; Wacker, L.; Synal, H.-A.

    2016-03-01

    A range of ion beam analysis activities are ongoing at Uppsala University, including Accelerator Mass Spectrometry (AMS). Various isotopes are used for AMS but the isotope with the widest variety of applications is radiocarbon. Up until recently, only the 5 MV Pelletron tandem accelerator had been used at our site for radiocarbon AMS, ordinarily using 12 MeV 14,13,12C3+ ions. Recently a new radiocarbon AMS system, the Green-MICADAS, developed at the ion physics group at ETH Zurich, was installed. The system has a number of outstanding features which will be described. The system operates at a terminal voltage of 175 kV and uses helium stripper gas, extracting singly charged carbon ions. The low- and high energy mass spectrometers in the system are stigmatic dipole permanent magnets (0.42 and 0.97 T) requiring no electrical power nor cooling water. The system measures both the 14C/12C and the 13C/12C ratios on-line. Performance of the system is presented for both standard mg samples as well as μg-sized samples.

  2. Trace and surface analysis of ceramic layers of solid oxide fuel cells by mass spectrometry.

    Science.gov (United States)

    Becker, J S; Breuer, U; Westheide, J; Saprykin, A I; Holzbrecher, H; Nickel, H; Dietze, H J

    1996-06-01

    For the trace analysis of impurities in thick ceramic layers of a solid oxide fuel cell (SOFC) sensitive solid-state mass spectrometric methods, such as laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and radiofrequency glow discharge mass spectrometry (rf-GDMS) have been developed and used. In order to quantify the analytical results of LA-ICP-MS, the relative sensitivity coefficients of elements in a La(0.6)Sr(0.35)MnO(3) matrix have been determined using synthetic standards. Secondary ion mass spectrometry (SIMS) - as a surface analytical method - has been used to characterize the element distribution and diffusion profiles of matrix elements on the interface of a perovskite/Y-stabilized ZrO(2) layer. The application of different mass spectrometric methods for process control in the preparation of ceramic layers for the SOFC is described.

  3. Mass transfer inside oblate spheroidal solids: modelling and simulation

    Directory of Open Access Journals (Sweden)

    J. E. F. Carmo

    2008-03-01

    Full Text Available A numerical solution of the unsteady diffusion equation describing mass transfer inside oblate spheroids, considering a constant diffusion coefficient and the convective boundary condition, is presented. The diffusion equation written in the oblate spheroidal coordinate system was used for a two-dimensional case. The finite-volume method was employed to discretize the basic equation. The linear equation set was solved iteratively using the Gauss-Seidel method. As applications, the effects of the Fourier number, the Biot number and the aspect ratio of the body on the drying rate and moisture content during the process are presented. To validate the methodology, results obtained in this work are compared with analytical results of the moisture content encountered in the literature and good agreement was obtained. The results show that the model is consistent and it may be used to solve cases such as those that include disks and spheres and/or those with variable properties with small modifications.

  4. Mass measurement of right-handed scalar quarks and time measurement of hadronic showers for the compact linear collider

    International Nuclear Information System (INIS)

    Weuste, Lars

    2013-01-01

    The Compact Linear Collider (CLIC) is a concept for a 48.3 km long e + e - accelerator with a center-of-mass energy of 3TeV. Its purpose is the precise measurement of particles discovered by the LHC as well as the discovery of yet unknown particles. The International Large Detector (ILD) is one of its detector concepts which was specifically designed for the usage of the Particle Flow Algorithm. This thesis is divided into two parts, both within the context of CLIC. In the first part of this thesis the unprecedented measurement on time structure of hadronic showers in calorimeters with tungsten absorber material, which is used in the ILD concept for CLIC, is presented. It shows the development and the construction of a small testbeam experiment called Tungsten Timing Testbeam (T3B) which consists of only 15 scintillator tiles of 30 x 30 x 5 mm 3 , read out with Silicon Photomultipliers which in turn were connected to USB oscilloscopes. T3B was placed downstream of the CALICE tungsten analog hadron calorimeter (W-AHCal) during beam tests performed at CERN in 2010 and 2011. The resulting data is compared to simulation obtained with three different hadronic shower physics models of the Geant4 simulation toolkit: QGSPBERT, QGSPBERTHP and QBBC. The results from 60 GeV high statistics run show that QBBC and QGSPBERTHP are mostly consistent with the testbeam data, while QGSPBERT, which is lacking a sophisticated treatment of neutrons, overestimates the late energy depositions. The second part of this thesis presents one out of the six benchmark processes that were part of the CLIC Conceptual Design Report (CDR) to verify the detector performance at CLIC. This benchmark process is the measurement of the mass and cross-section of two supersymmetric right-handed scalar quarks. In the underlying SUSY model these almost exclusively decay into the lightest neutralino (missing energy) and the corresponding standard model quark (jet). Within this analysis pile-up from beam

  5. WEAK AND COMPACT RADIO EMISSION IN EARLY HIGH-MASS STAR-FORMING REGIONS. I. VLA OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Rosero, V.; Hofner, P. [Physics Department, New Mexico Tech, 801 Leroy Pl., Socorro, NM 87801 (United States); Claussen, M. [National Radio Astronomy Observatory, 1003 Lopezville Rd., Socorro, NM 87801 (United States); Kurtz, S.; Carrasco-González, C.; Rodríguez, L. F.; Loinard, L. [Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Morelia 58090, México (Mexico); Cesaroni, R. [INAF, Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy); Araya, E. D. [Physics Department, Western Illinois University, 1 University Circle, Macomb, IL 61455 (United States); Menten, K. M.; Wyrowski, F. [Max-Planck-Institute für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Ellingsen, S. P. [School of Physical Sciences, University of Tasmania, Private Bag 37, Hobart, Tasmania 7001 (Australia)

    2016-12-01

    We present a high-sensitivity radio continuum survey at 6 and 1.3 cm using the Karl G. Jansky Very Large Array toward a sample of 58 high-mass star-forming regions. Our sample was chosen from dust clumps within infrared dark clouds with and without IR sources (CMC–IRs and CMCs, respectively), and hot molecular cores (HMCs), with no previous, or relatively weak radio continuum detection at the 1 mJy level. Due to the improvement in the continuum sensitivity of the Very Large Array, this survey achieved map rms levels of ∼3–10  μ Jy beam{sup −1} at sub-arcsecond angular resolution. We extracted 70 continuum sources associated with 1.2 mm dust clumps. Most sources are weak, compact, and prime candidates for high-mass protostars. Detection rates of radio sources associated with the millimeter dust clumps for CMCs, CMC–IRs, and HMCs are 6%, 53%, and 100%, respectively. This result is consistent with increasing high-mass star formation activity from CMCs to HMCs. The radio sources located within HMCs and CMC–IRs occur close to the dust clump centers, with a median offset from it of 12,000 au and 4000 au, respectively. We calculated 5–25 GHz spectral indices using power-law fits and obtained a median value of 0.5 (i.e., flux increasing with frequency), suggestive of thermal emission from ionized jets. In this paper we describe the sample, observations, and detections. The analysis and discussion will be presented in Paper II.

  6. Low density lesion in solid mass on CT: Pathologic change and housfield number

    International Nuclear Information System (INIS)

    Han, Tae Il; Lim, Joo Won; Ryu, Kyung Nam; Ko, Young Tae; Song, Mi Jin; Lee, Dong Ho; Lee, Ju Hie

    1994-01-01

    We retrospectively reviewed the pathologic changes and housfield unit of the low density lesion in solid mass on CT. Pathologically proved solid mass was evaluated in regard to the shape and margin of the low density in the mass on the CT scans of 23 patient. The CT number of the low density lesion was correlated with the pathologic changes. Pathologic changes of the low density lesions were; necrosis (n=17), hemorrhage (n=13), cyst (n=4), myxoid degeneration (n=2), hyaline degeneration (n=1), fibrosis (n=1), and mixed cellularity (n=1). In 14 cases, more than 2 pathologic changes were seen. In 11 cases, necrosis was associated with hemorrhage. The CT number ranged from 11.5 to 44.9 Housfield unit(HU) (mean, 25.2 HU). The average CT number was 26.9 HU in hemorrhage and necrosis, 17.2 HU in cystic change, 20.9 HU in myxoid degeneration, 35.7 HU in hyaline de generation, 22.3 HU in fibrosis, and 21.4 HU in mixed cellularity. The hemorrhage and necrosis in 17 cases showed irregular margin, amorphous shape, and showed centrifugal distribution. The cystic change in 4 cases showed well defined margin, round shape, and peripheral location in solid mass. The low density lesions in solid mass on CT represented variable pathologic changes; necrosis, hemorrhage, cyst, myxoid degeneration, hyaline degeneration, fibrosis, and mixed cellularity. Pathologic changes would not be differentiated on the basis of CT number

  7. Method and apparatus for accelerating a solid mass

    International Nuclear Information System (INIS)

    Tidman, D.A.; Goldstein, Y.A.

    1984-01-01

    An axi-symmetrical projectile, having a mass ranging from fractions of a gram to kilograms, is accelerated to velocities in the range of 10 5 to 10 7 centimeters per second by a propelling force produced by a plasma resulting from electric discharge. The discharge is imploded against the projectile surface so lines of the magnetic fields are approximately azimuthal around the projectile axis. The projectile is tapered so it experiences a net, stable axial accelerating force along the accelerator axis by the combined action of the magnetic field producing radially directed momentum and pressure on the plasma, the interaction of the magnetic field and ions induced by the plasma on the surface, as well as material the plasma ablates from the surface. The plasma discharge is initiated either in low density background gas between anode and cathode of a discharge module, or along an insulator surface between the electrodes in low density background gas. Alternatively, in either of these situations the discharge can be initiated in a gas which is produced by ablation of the projectile surface. In an alternative situation, the projectile acts as a switch for triggering discharges. Eddy current heating of the projectile is minimized by shaping the discharge current pulse so the plasma has a relatively weak magnetic field when it arrives at the surface, or by making the projectile electrically non-conducting. To provide a long acceleration path, a series of modules is aligned. In one embodiment, the projectile position, as it advances between modules, is sensed and discharges are switched on sequentially in the modules

  8. Design of a compact thermal ionization mass spectrometer for isotopic ratio measurement of nuclear material

    International Nuclear Information System (INIS)

    Bhatia, R.K.; Yadav, V.K.; Ravisankar, E.; Nataraju, V.; Gadkari, S.C.

    2017-01-01

    High precision isotope ratio analysis of materials of interest in nuclear and geological applications is carried out by thermal ionization mass spectrometry (TIMS) technique. One of the important mandates of Bhabha Atomic Research Centre (BARC) has been developing these instruments and several TIMS instruments have been developed and deployed at user sites covering a wide range material of interest relevant to various stages of the nuclear power cycle. The instrument designs for above applications are based on two geometries of magnetic sector ie., 15 cm sector radius and 30 cm sector radius with resolutions as 200 and 400 respectively. There has been a conscious effort to improve the the sensitivity and precision of these models by modifying the designs of the sub-systems. In the recent past, a new ion optical element viz., variable dispersion zoom optics (VDZO) was introduced in the collector system of the standard model with 30cm radius magnet, to increase the dispersion of the ion beams which enabled to fix the locations of the Faraday cups (upto 6 nos.) instead of the conventional movable ones. After establishing the usefulness of VDZO, an attempt is being made to design and develop a 20 cm magnet based TIMS which will have a much smaller foot print compared to the standard 30 cm model and also covers the usual range of elements (viz. Li - U). The ion optical design was optimized using computer simulations with SIMION 7.0 software and subsequently the mechanical design was carried out using Autocad computer software. Some of the details of this new design are presented in this abstract

  9. Epi-detecting label-free multimodal imaging platform using a compact diode-pumped femtosecond solid-state laser

    DEFF Research Database (Denmark)

    Andreana, Marco; Le, Tuan; Hansen, Anders Kragh

    2017-01-01

    We have developed an epi-detected multimodal nonlinear optical microscopy platform based on a compact and cost-effective laser source featuring simultaneous acquisition of signals arising from hyperspectral coherent anti-Stokes Raman scattering (CARS), two-photon fluorescence, and second harmonic...

  10. A compact 10 kW, 476 MHz solid state radio frequency amplifier for pre-buncher cavity of free electron laser injector linear accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Mohania, Praveen; Mahawar, Ashish; Shrivastava, Purushottam; Gupta, P. D. [Raja Rammana Centre for Advanced Technology (RRCAT), Indore 452013 (India)

    2013-09-15

    A 10 kW, 476 MHz, 0.1% duty cycle solid state RF amplifier system for driving sub-harmonic, pre-buncher cavity of IR-FEL injector LINAC, has been developed at RRCAT. The 10 kW power is achieved by combining output of eight 1400 W amplifier modules using 8-way planar corporate combiner. The solid state amplifier modules have been developed using 50 V RF LDMOS transistors which although meant for push-pull operation are being used in single ended configuration with matching circuit developed on a thin (25 mils), high dielectric constant (9.7), low loss microwave laminate with an aim to have a compact structure. Ease of fabrication, modularity, small size, and low cost are the important features of this design which could be used as a template for low duty cycle medium to high pulsed power UHF amplifier system.

  11. NEAR-INFRARED SPECTROSCOPY OF LOW-MASS X-RAY BINARIES: ACCRETION DISK CONTAMINATION AND COMPACT OBJECT MASS DETERMINATION IN V404 Cyg AND Cen X-4

    International Nuclear Information System (INIS)

    Khargharia, Juthika; Froning, Cynthia S.; Robinson, Edward L.

    2010-01-01

    We present near-infrared (NIR) broadband (0.80-2.42 μm) spectroscopy of two low-mass X-ray binaries: V404 Cyg and Cen X-4. One important parameter required in the determination of the mass of the compact objects in these systems is the binary inclination. We can determine the inclination by modeling the ellipsoidal modulations of the Roche-lobe filling donor star, but the contamination of the donor star light from other components of the binary, particularly the accretion disk, must be taken into account. To this end, we determined the donor star contribution to the infrared flux by comparing the spectra of V404 Cyg and Cen X-4 to those of various field K-stars of known spectral type. For V404 Cyg, we determined that the donor star has a spectral type of K3 III. We determined the fractional donor contribution to the NIR flux in the H and K bands as 0.98 ± 0.05 and 0.97 ± 0.09, respectively. We remodeled the H-band light curve from Sanwal et al. after correcting for the donor star contribution to obtain a new value for the binary inclination. From this, we determined the mass of the black hole in V404 Cyg to be M BH = 9.0 +0.2 -0.6 M sun . We performed the same spectral analysis for Cen X-4 and found the spectral type of the donor star to be in the range K5-M1 V. The donor star contribution in Cen X-4 is 0.94 ± 0.14 in the H band while in the K band, the accretion disk can contribute up to 10% of the infrared flux. We remodeled the H-band light curve from Shahbaz et al., again correcting for the fractional contribution of the donor star to obtain the inclination. From this, we determined the mass of the neutron star as M NS = 1.5 +0.1 -0.4 M sun . However, the masses obtained for both systems should be viewed with some caution since contemporaneous light curve and spectral data are required to obtain definitive masses.

  12. Mass measurement of right-handed scalar quarks and time measurement of hadronic showers for the compact linear collider

    CERN Document Server

    Weuste, Lars

    The Compact Linear Collider (CLIC) is a concept for a 48.3km long e+ e- accelerator with a center-of-mass energy of 3TeV. Its purpose is the precise measurement of particles discovered by the LHC as well as the discovery of yet unknown particles. The International Large Detector (ILD) is one of its detector concepts which was specifically designed for the usage of the Particle Flow Algorithm. This thesis is divided into two parts, both within the context of CLIC. In the first part of this thesis the unprecedented measurement on time structure of hadronic showers in calorimeters with tungsten absorber material, which is used in the ILD concept for CLIC, will be presented. It shows the development and the construction of a small testbeam experiment called Tungsten Timing Testbeam (T3B) which consists of only 15 scintillator tiles of 30mm x 30mm x 5mm, read out with Silicon Photomultipliers which in turn were connected to USB oscilloscopes. T3B was placed downstream of the CALICE tungsten analog hadron calorimet...

  13. XCAMS: The compact 14C accelerator mass spectrometer extended for 10Be and 26Al at GNS Science, New Zealand

    Science.gov (United States)

    Zondervan, A.; Hauser, T. M.; Kaiser, J.; Kitchen, R. L.; Turnbull, J. C.; West, J. G.

    2015-10-01

    A detailed description is given of the 0.5 MV tandem accelerator mass spectrometry (AMS) system for 10Be, 14C, 26Al, installed in early 2010 at GNS Science, New Zealand. Its design follows that of previously commissioned Compact 14C-only AMS (CAMS) systems based on the Pelletron tandem accelerator. The only basic departure from that design is an extension of the rare-isotope achromat with a 45° magnet and a two-anode gas-ionisation detector, to provide additional filtering for 10Be. Realised performance of the three AMS modes is discussed in terms of acceptance-test scores, 14C Poisson and non-Poisson errors, and 10Be detection limit and sensitivity. Operational details and hardware improvements, such as 10Be beam transport and particle detector setup, are highlighted. Statistics of repeat measurements of all graphitised 14C calibration cathodes since start-up show that 91% of their total uncertainty values are less than 0.3%, indicating that the rare-isotope beamline extension has not affected precision of 14C measurement. For 10Be, the limit of detection in terms of the isotopic abundance ratio 10Be/9Be is 6 × 10-15 at at-1 and the total efficiency of counting atoms in the sample cathode is 1/8500 (0.012%).

  14. Simultaneous heat and mass transfer to air from a compact heat exchanger with water spray precooling and surface deluge cooling

    International Nuclear Information System (INIS)

    Zhang, Feini; Bock, Jessica; Jacobi, Anthony M.; Wu, Hailing

    2014-01-01

    Various methods are available to enhance heat exchanger performance with evaporative cooling. In this study, evaporative mist precooling, deluge cooling, and combined cooling schemes are examined experimentally and compared to model predictions. A flexible model of a compact, finned-tube heat exchanger with a wetted surface is developed by applying the governing conservation and rate equations and invoking the heat and mass transfer analogy. The model is applicable for dry, partially wet, or fully wet surface conditions and capable of predicting local heat/mass transfer, wetness condition, and pressure drop of the heat exchanger. Experimental data are obtained from wind tunnel experiments using a louver-fin flat-tube heat exchanger with single-phase tube-side flow. Total capacity, pressure drop, and water drainage behavior under various water usage rates and air face velocities are analyzed and compared to data for dry-surface conditions. A heat exchanger partitioning method for evaporative cooling is introduced to study partially wet surface conditions, as part of a consistent and general method for interpreting wet-surface performance data. The heat exchanger is partitioned into dry and wet portions by introducing a wet surface factor. For the wet part, the enthalpy potential method is used to determine the air-side sensible heat transfer coefficient. Thermal and hydraulic performance is compared to empirical correlations. Total capacity predictions from the model agree with the experimental results with an average deviation of 12.6%. The model is also exercised for four water augmentation schemes; results support operating under a combined mist precooling and deluge cooling scheme. -- Highlights: • A new spray-cooled heat exchanger model is presented and is validated with data. • Heat duty is shown to be asymptotic with spray flow rate. • Meaningful heat transfer coefficients for partially wet conditions are obtained. • Colburn j wet is lower than j dry

  15. A coupled theory for chemically active and deformable solids with mass diffusion and heat conduction

    Science.gov (United States)

    Zhang, Xiaolong; Zhong, Zheng

    2017-10-01

    To analyse the frequently encountered thermo-chemo-mechanical problems in chemically active material applications, we develop a thermodynamically-consistent continuum theory of coupled deformation, mass diffusion, heat conduction and chemical reaction. Basic balance equations of force, mass and energy are presented at first, and then fully coupled constitutive laws interpreting multi-field interactions and evolving equations governing irreversible fluxes are constructed according to the energy dissipation inequality and the chemical kinetics. To consider the essential distinction between mass diffusion and chemical reactions in affecting free energy and dissipations of a highly coupled system, we regard both the concentrations of diffusive species and the extent of reaction as independent state variables. This new formulation then distinguishes between the energy contribution from the diffusive species entering the solid and that from the subsequent chemical reactions occurring among these species and the host solid, which not only interact with stresses or strains in different manners and on different time scales, but also induce different variations of solid microstructures and material properties. Taking advantage of this new description, we further establish a specialized isothermal model to predict precisely the transient chemo-mechanical response of a swelling solid with a proposed volumetric constraint that accounts for material incompressibility. Coupled kinetics is incorporated to capture the volumetric swelling of the solid caused by imbibition of external species and the simultaneous dilation arised from chemical reactions between the diffusing species and the solid. The model is then exemplified with two numerical examples of transient swelling accompanied by chemical reaction. Various ratios of characteristic times of diffusion and chemical reaction are taken into account to shed light on the dependency on kinetic time scales of evolution patterns for

  16. Robust Modelling of Heat and Mass Transfer in Processing of Solid Foods

    DEFF Research Database (Denmark)

    Feyissa, Aberham Hailu

    The study is focused on combined heat and mass transfer during processing of solid foods such as baking and frying processes. Modelling of heat and mass transfer during baking and frying is a significant scientific challenge. During baking and frying, the food undergoes several changes...... in microstructure and other physical properties of the food matrix. The heat and water transport inside the food is coupled in a complex way, which for some food systems it is not yet fully understood. A typical example of the latter is roasting of meat in convection oven, where the mechanism of water transport...... is unclear. Establishing the robust mathematical models describing the main mechanisms reliably is of great concern. A quantitative description of the heat and mass transfer during the solid food processing, in the form of mathematical equations, implementation of the solution techniques, and the value...

  17. Reproducibility and diagnostic performance of shear wave elastography in evaluating breast solid mass.

    Science.gov (United States)

    Hong, Sun; Woo, Ok Hee; Shin, Hye Seon; Hwang, Soon-Young; Cho, Kyu Ran; Seo, Bo Kyoung

    Shear wave elastography (SWE) was performed independently by two radiologists in 264 solid breast masses. The images were reviewed for color overlay pattern (COP) classification by the two radiologists, double blinded to any information. The interobserver agreement of the COP was almost perfect (κ=0.908) and high in E max (ICC=0.89). The AUC value of the COP (0.954) was significantly higher than that of E max (0.915) (p=0.002) but not significantly different from that of E max combined with COP (0.957) (p=0.098). The SWE color overlay pattern and E max of breast masses were highly reproducible. The COP had better diagnostic ability than E max , suggesting that COP may be a more reliable parameter for solid breast mass evaluation. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Mass measurement of right-handed scalar quarks and time measurement of hadronic showers for the compact linear collider

    Energy Technology Data Exchange (ETDEWEB)

    Weuste, Lars

    2013-06-12

    The Compact Linear Collider (CLIC) is a concept for a 48.3 km long e{sup +}e{sup -} accelerator with a center-of-mass energy of 3TeV. Its purpose is the precise measurement of particles discovered by the LHC as well as the discovery of yet unknown particles. The International Large Detector (ILD) is one of its detector concepts which was specifically designed for the usage of the Particle Flow Algorithm. This thesis is divided into two parts, both within the context of CLIC. In the first part of this thesis the unprecedented measurement on time structure of hadronic showers in calorimeters with tungsten absorber material, which is used in the ILD concept for CLIC, is presented. It shows the development and the construction of a small testbeam experiment called Tungsten Timing Testbeam (T3B) which consists of only 15 scintillator tiles of 30 x 30 x 5 mm{sup 3}, read out with Silicon Photomultipliers which in turn were connected to USB oscilloscopes. T3B was placed downstream of the CALICE tungsten analog hadron calorimeter (W-AHCal) during beam tests performed at CERN in 2010 and 2011. The resulting data is compared to simulation obtained with three different hadronic shower physics models of the Geant4 simulation toolkit: QGSPBERT, QGSPBERTHP and QBBC. The results from 60 GeV high statistics run show that QBBC and QGSPBERTHP are mostly consistent with the testbeam data, while QGSPBERT, which is lacking a sophisticated treatment of neutrons, overestimates the late energy depositions. The second part of this thesis presents one out of the six benchmark processes that were part of the CLIC Conceptual Design Report (CDR) to verify the detector performance at CLIC. This benchmark process is the measurement of the mass and cross-section of two supersymmetric right-handed scalar quarks. In the underlying SUSY model these almost exclusively decay into the lightest neutralino (missing energy) and the corresponding standard model quark (jet). Within this analysis pile

  19. Compact Two-step Laser Time-of-Flight Mass Spectrometer for in Situ Analyses of Aromatic Organics on Planetary Missions

    Science.gov (United States)

    Getty, Stephanie; Brickerhoff, William; Cornish, Timothy; Ecelberger, Scott; Floyd, Melissa

    2012-01-01

    RATIONALE A miniature time-of-flight mass spectrometer has been adapted to demonstrate two-step laser desorption-ionization (LOI) in a compact instrument package for enhanced organics detection. Two-step LDI decouples the desorption and ionization processes, relative to traditional laser ionization-desorption, in order to produce low-fragmentation conditions for complex organic analytes. Tuning UV ionization laser energy allowed control ofthe degree of fragmentation, which may enable better identification of constituent species. METHODS A reflectron time-of-flight mass spectrometer prototype measuring 20 cm in length was adapted to a two-laser configuration, with IR (1064 nm) desorption followed by UV (266 nm) postionization. A relatively low ion extraction voltage of 5 kV was applied at the sample inlet. Instrument capabilities and performance were demonstrated with analysis of a model polycyclic aromatic hydrocarbon, representing a class of compounds important to the fields of Earth and planetary science. RESULTS L2MS analysis of a model PAH standard, pyrene, has been demonstrated, including parent mass identification and the onset o(tunable fragmentation as a function of ionizing laser energy. Mass resolution m/llm = 380 at full width at half-maximum was achieved which is notable for gas-phase ionization of desorbed neutrals in a highly-compact mass analyzer. CONCLUSIONS Achieving two-step laser mass spectrometry (L2MS) in a highly-miniature instrument enables a powerful approach to the detection and characterization of aromatic organics in remote terrestrial and planetary applications. Tunable detection of parent and fragment ions with high mass resolution, diagnostic of molecular structure, is possible on such a compact L2MS instrument. Selectivity of L2MS against low-mass inorganic salt interferences is a key advantage when working with unprocessed, natural samples, and a mechanism for the observed selectivity is presented.

  20. Maximum mass ratio of am CVn-type binary systems and maximum white dwarf mass in ultra-compact x-ray binaries (addendum - Serb. Astron. J. No. 183 (2011, 63

    Directory of Open Access Journals (Sweden)

    Arbutina B.

    2012-01-01

    Full Text Available We recalculated the maximum white dwarf mass in ultra-compact X-ray binaries obtained in an earlier paper (Arbutina 2011, by taking the effects of super-Eddington accretion rate on the stability of mass transfer into account. It is found that, although the value formally remains the same (under the assumed approximations, for white dwarf masses M2 >~0.1MCh mass ratios are extremely low, implying that the result for Mmax is likely to have little if any practical relevance.

  1. Compact stars

    Science.gov (United States)

    Estevez-Delgado, Gabino; Estevez-Delgado, Joaquin

    2018-05-01

    An analysis and construction is presented for a stellar model characterized by two parameters (w, n) associated with the compactness ratio and anisotropy, respectively. The reliability range for the parameter w ≤ 1.97981225149 corresponds with a compactness ratio u ≤ 0.2644959374, the density and pressures are positive, regular and monotonic decrescent functions, the radial and tangential speed of sound are lower than the light speed, moreover, than the plausible stability. The behavior of the speeds of sound are determinate for the anisotropy parameter n, admitting a subinterval where the speeds are monotonic crescent functions and other where we have monotonic decrescent functions for the same speeds, both cases describing a compact object that is also potentially stable. In the bigger value for the observational mass M = 2.05 M⊙ and radii R = 12.957 Km for the star PSR J0348+0432, the model indicates that the maximum central density ρc = 1.283820319 × 1018 Kg/m3 corresponds to the maximum value of the anisotropy parameter and the radial and tangential speed of the sound are monotonic decrescent functions.

  2. Data summary of municipal solid waste management alternatives. Volume 3, Appendix A: Mass burn technologies

    Energy Technology Data Exchange (ETDEWEB)

    None

    1992-10-01

    This appendix on Mass Burn Technologies is the first in a series designed to identify, describe and assess the suitability of several currently or potentially available generic technologies for the management of municipal solid waste (MSW). These appendices, which cover eight core thermoconversion, bioconversion and recycling technologies, reflect public domain information gathered from many sources. Representative sources include: professional journal articles, conference proceedings, selected municipality solid waste management plans and subscription technology data bases. The information presented is intended to serve as background information that will facilitate the preparation of the technoeconomic and life cycle mass, energy and environmental analyses that are being developed for each of the technologies. Mass burn has been and continues to be the predominant technology in Europe for the management of MSW. In the United States, the majority of the existing waste-to-energy projects utilize this technology and nearly 90 percent of all currently planned facilities have selected mass burn systems. Mass burning generally refers to the direct feeding and combustion of municipal solid waste in a furnace without any significant waste preprocessing. The only materials typically removed from the waste stream prior to combustion are large bulky objects and potentially hazardous or undesirable wastes. The technology has evolved over the last 100 or so years from simple incineration to the most highly developed and commercially proven process available for both reducing the volume of MSW and for recovering energy in the forms of steam and electricity. In general, mass burn plants are considered to operate reliably with high availability.

  3. Application of a compact diode pumped solid-state laser source for quantitative laser-induced breakdown spectroscopy analysis of steel

    Science.gov (United States)

    Tortschanoff, Andreas; Baumgart, Marcus; Kroupa, Gerhard

    2017-12-01

    Laser-induced breakdown spectroscopy (LIBS) technology holds the potential for onsite real-time measurements of steel products. However, for a mobile and robust LIBS measurement system, an adequate small and ruggedized laser source is a key requirement. In this contribution, we present tests with our compact high-power laser source, which, initially, was developed for ignition applications. The CTR HiPoLas® laser is a robust diode pumped solid-state laser with a passive Q-switch with dimensions of less than 10 cm3. The laser generates 2.5-ns pulses with 30 mJ at a maximum continuous repetition rate of about 30 Hz. Feasibility of LIBS experiments with the laser source was experimentally verified with steel samples. The results show that the laser with its current optical output parameters is very well-suited for LIBS measurements. We believe that the miniaturized laser presented here will enable very compact and robust portable high-performance LIBS systems.

  4. A review of the applications to solids of the laser ion source in mass spectrometry

    International Nuclear Information System (INIS)

    Conzemius, R.J.; Capellen, J.M.

    1980-01-01

    The review is intended to provide a panoramic view of the broadening applications of the laser ion source in mass spectrometry. In these applications a laser beam has been used to excite a solid specimen to the ionized state or to the vaporized state in the ion source of a mass spectrometer. The review is divided into two main sections: Analytical features and applications. The analytical features section has been subdivided into five areas: Detection sensitivity, ionisation efficiency, collection efficiency, quantification, and crater-depth analysis. Applications have been separated into ten different areas: Biological, carbon, fossil fuels, gaseous impurities, geological, inorganics, isotopic analysis, metals, organics and polymers. (EBE)

  5. Static secondary ion mass spectrometry for organic and inorganic molecular analysis in solids

    International Nuclear Information System (INIS)

    Ham, Rita van; Vaeck, Luc van; Adriaens, Annemie; Adams, Freddy

    2003-01-01

    The use of mass spectra in secondary ion mass spectrometry (S-SIMS) to characterise the molecular composition of inorganic and organic analytes at the surface of solid samples is investigated. Methodological aspects such as mass resolution, mass accuracy, precision and accuracy of isotope abundance measurements, influence of electron flooding and sample morphology are addressed to assess the possibilities and limitations that the methodology can offer to support the structural assignment of the detected ions. The in-sample and between-sample reproducibility of relative peak intensities under optimised conditions is within 10%, but experimental conditions and local hydration, oxidation or contamination can drastically affect the mass spectra. As a result, the use of fingerprinting for identification becomes compromised. Therefore, the preferred way of interpretation becomes the deductive structural approach, based on the use of the empirical desorption-ionisation model. This approach is shown to allow the molecular composition of inorganic and organic components at the surface of solids to be characterised. Examples of inorganic speciation and identification of organic additives with unknown composition in inorganic salt mixtures are given. The methodology is discussed in terms of foreseen developments with respect to the use of polyatomic primary ions

  6. A Compact Tandem Two-Step Laser Time-of-Flight Mass Spectrometer for In Situ Analysis of Non-Volatile Organics on Planetary Surfaces

    Science.gov (United States)

    Getty, Stephanie A.; Brinckerhoff, William B.; Li, Xiang; Elsila, Jamie; Cornish, Timothy; Ecelberger, Scott; Wu, Qinghao; Zare, Richard

    2014-01-01

    Two-step laser desorption mass spectrometry is a well suited technique to the analysis of high priority classes of organics, such as polycyclic aromatic hydrocarbons, present in complex samples. The use of decoupled desorption and ionization laser pulses allows for sensitive and selective detection of structurally intact organic species. We have recently demonstrated the implementation of this advancement in laser mass spectrometry in a compact, flight-compatible instrument that could feasibly be the centerpiece of an analytical science payload as part of a future spaceflight mission to a small body or icy moon.

  7. Quantitative shear wave ultrasound elastography: initial experience in solid breast masses

    OpenAIRE

    Evans, Andrew; Whelehan, Patsy; Thomson, Kim; McLean, Denis; Brauer, Katrin; Purdie, Colin; Jordan, Lee; Baker, Lee; Thompson, Alastair

    2010-01-01

    Introduction Shear wave elastography is a new method of obtaining quantitative tissue elasticity data during breast ultrasound examinations. The aims of this study were (1) to determine the reproducibility of shear wave elastography (2) to correlate the elasticity values of a series of solid breast masses with histological findings and (3) to compare shear wave elastography with greyscale ultrasound for benign/malignant classification. Methods Using the Aixplorer® ultrasound system (SuperSoni...

  8. Influence of flotation cell volume and solids mass on kinetics of sulfide ore flotation

    Directory of Open Access Journals (Sweden)

    Plawski Michal

    2016-01-01

    Full Text Available The paper presents studies on the influence of flotation cell capacity and mass of solids in the suspension on the flotation kinetics of sulfide copper ore. A sample of copper ore that was collected from the Polkowice Mine of KGHM Polska Miedz S.A. in Poland was used in the experiments. It was determined that neither the volume of flotation cell nor the mass of solids had influence on the type of kinetics equation of flotation. Copper-bearing minerals floated according to the second-order equation, while the remaining components according to the first-order equation. The kinetic rate constants and maximum recovery of the studied components decreased with increasing solids mass in the flotation cell, regardless of the capacity of the cell. The best results were obtained for tests using a 1.0 dm3 cell, while the less favorable kinetics results were observed in the test with the smallest cell of 0.75 dm3 volume. The obtained results can be helpful in choosing the most appropriate methodology of upgrading the sulfide copper ore from Poland in order to obtain the best kinetics results.

  9. The effect of gas double-dynamic on mass distribution in solid-state fermentation.

    Science.gov (United States)

    Chen, Hong-Zhang; Zhao, Zhi-Min; Li, Hong-Qiang

    2014-05-10

    The mass distribution regularity in substrate of solid-state fermentation (SSF) has rarely been reported due to the heterogeneity of solid medium and the lack of suitable instrument and method, which limited the comprehensive analysis and enhancement of the SSF performance. In this work, the distributions of water, biomass, and fermentation product in different medium depths of SSF were determined using near-infrared spectroscopy (NIRS) and the developed models. Based on the mass distribution regularity, the effects of gas double-dynamic on heat transfer, microbial growth and metabolism, and product distribution gradient were systematically investigated. Results indicated that the maximum temperature of substrate and the maximum carbon dioxide evolution rate (CER) were 39.5°C and 2.48mg/(hg) under static aeration solid-state fermentation (SASSF) and 33.9°C and 5.38mg/(hg) under gas double-dynamic solid-state fermentation (GDSSF), respectively, with the environmental temperature for fermentation of 30±1°C. The fermentation production (cellulase activity) ratios of the upper, middle, and lower levels were 1:0.90:0.78 at seventh day under SASSF and 1:0.95:0.89 at fifth day under GDSSF. Therefore, combined with NIRS analysis, gas double-dynamic could effectively strengthen the solid-state fermentation performance due to the enhancement of heat transfer, the stimulation of microbial metabolism and the increase of the homogeneity of fermentation products. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. OBSERVATIONAL UPPER BOUND ON THE COSMIC ABUNDANCES OF NEGATIVE-MASS COMPACT OBJECTS AND ELLIS WORMHOLES FROM THE SLOAN DIGITAL SKY SURVEY QUASAR LENS SEARCH

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Ryuichi; Asada, Hideki [Faculty of Science and Technology, Hirosaki University, Hirosaki 036-8561 (Japan)

    2013-05-01

    The latest result in the Sloan Digital Sky Survey Quasar Lens Search (SQLS) has set the first cosmological constraints on negative-mass compact objects and Ellis wormholes. There are no multiple images lensed by the above two exotic objects for {approx}50, 000 distant quasars in the SQLS data. Therefore, an upper bound is put on the cosmic abundances of these lenses. The number density of negative-mass compact objects is n < 10{sup -8}(10{sup -4}) h {sup 3} Mpc{sup -3} at the mass scale |M| > 10{sup 15}(10{sup 12}) M{sub Sun }, which corresponds to the cosmological density parameter |{Omega}| < 10{sup -4} at the galaxy and cluster mass range |M| = 10{sup 12-15} M{sub Sun }. The number density of the Ellis wormhole is n < 10{sup -4} h {sup 3} Mpc{sup -3} for a range of the throat radius a = 10-10{sup 4} pc, which is much smaller than the Einstein ring radius.

  11. The treatment of municipal solid waste in Malaysia comparing the biothennal process and mass burning

    Energy Technology Data Exchange (ETDEWEB)

    Fogelholm, C.J.; Iso-Tryykari, M.

    1997-12-31

    Mass burning is the previously much used technology in the combustion of municipal solid waste. In mass burning, unsorted waste is burned on a grate. The Biothermal Process is a new innovative municipal solid waste treatment concept. It consists of front end treatment, the biogasification of the biofraction and the fluidized bed combustion of the combustible fraction. The objective of this work is to compare the technical, environmental and economical features of the Biothermal Process and mass burning, when constructed in Malaysia. Firstly technical descriptions of concepts are presented. Secondly three cases namely Kuala Lumpur, Perai and Johor Bahru are studied. Finally conclusions are drawn. Economic comparisons revealed that the Biothermal Process is more economical than mass burning. The investment cost far the Biothermal Process is about 30 % lower than for mass burning plant. To achieve an 8 % Return on Investment, the treatment fee for the Biothermal Process is 47-95 MYR per tonne and for mass burning 181-215 MYR per tonne depending on the case. The sensibility analysis showed that independent of the variations in feeding values, the treatment fee remains much lower in the Biothermal Process. Technical comparisons show that the Biothermal Process has the better waste reduction and recycling rate in all cases. The Biothermal Process has much better electrical efficiency in the Kuala Lumpur and Johor Bahru cases, while mass burning has slightly better electrical efficiency in the Perai case. Both concepts have postal for phased construction, but phasing increases investment costs more in mass burning. The suitability of each concept to the differences in the quality of waste depends on local conditions, and both methods have merits. The Biothermal Process produces 45-70 % lower air emissions than mass burning, and generates less traffic in Kuala Lumpur and Perai, while traffic generation is equal in the Johor Bahru case. The comparisons show that according

  12. Digital image processing based mass flow rate measurement of gas/solid two-phase flow

    Energy Technology Data Exchange (ETDEWEB)

    Song Ding; Peng Lihui; Lu Geng; Yang Shiyuan [Tsinghua National Laboratory for Information Science and Technology, Department of Automation, Tsinghua University, Beijing, 100084 (China); Yan Yong, E-mail: lihuipeng@tsinghua.edu.c [University of Kent, Canterbury, Kent CT2 7NT (United Kingdom)

    2009-02-01

    With the rapid growth of the process industry, pneumatic conveying as a tool for the transportation of a wide variety of pulverized and granular materials has become widespread. In order to improve plant control and operational efficiency, it is essential to know the parameters of the particle flow. This paper presents a digital imaging based method which is capable of measuring multiple flow parameters, including volumetric concentration, velocity and mass flow rate of particles in the gas/solid two phase flow. The measurement system consists of a solid state laser for illumination, a low-cost CCD camera for particle image acquisition and a microcomputer with bespoke software for particle image processing. The measurements of particle velocity and volumetric concentration share the same sensing hardware but use different exposure time and different image processing methods. By controlling the exposure time of the camera a clear image and a motion blurred image are obtained respectively. The clear image is thresholded by OTSU method to identify the particles from the dark background so that the volumetric concentration is determined by calculating the ratio between the particle area and the total area. Particle velocity is derived from the motion blur length, which is estimated from the motion blurred images by using the travelling wave equation method. The mass flow rate of particles is calculated by combining the particle velocity and volumetric concentration. Simulation and experiment results indicate that the proposed method is promising for the measurement of multiple parameters of gas/solid two-phase flow.

  13. Digital image processing based mass flow rate measurement of gas/solid two-phase flow

    International Nuclear Information System (INIS)

    Song Ding; Peng Lihui; Lu Geng; Yang Shiyuan; Yan Yong

    2009-01-01

    With the rapid growth of the process industry, pneumatic conveying as a tool for the transportation of a wide variety of pulverized and granular materials has become widespread. In order to improve plant control and operational efficiency, it is essential to know the parameters of the particle flow. This paper presents a digital imaging based method which is capable of measuring multiple flow parameters, including volumetric concentration, velocity and mass flow rate of particles in the gas/solid two phase flow. The measurement system consists of a solid state laser for illumination, a low-cost CCD camera for particle image acquisition and a microcomputer with bespoke software for particle image processing. The measurements of particle velocity and volumetric concentration share the same sensing hardware but use different exposure time and different image processing methods. By controlling the exposure time of the camera a clear image and a motion blurred image are obtained respectively. The clear image is thresholded by OTSU method to identify the particles from the dark background so that the volumetric concentration is determined by calculating the ratio between the particle area and the total area. Particle velocity is derived from the motion blur length, which is estimated from the motion blurred images by using the travelling wave equation method. The mass flow rate of particles is calculated by combining the particle velocity and volumetric concentration. Simulation and experiment results indicate that the proposed method is promising for the measurement of multiple parameters of gas/solid two-phase flow.

  14. Characterization of rhamnolipids by liquid chromatography/mass spectrometry after solid-phase extraction.

    Science.gov (United States)

    Behrens, Beate; Engelen, Jeannine; Tiso, Till; Blank, Lars Mathias; Hayen, Heiko

    2016-04-01

    Rhamnolipids are surface-active agents with a broad application potential that are produced in complex mixtures by bacteria of the genus Pseudomonas. Analysis from fermentation broth is often characterized by laborious sample preparation and requires hyphenated analytical techniques like liquid chromatography coupled to mass spectrometry (LC-MS) to obtain detailed information about sample composition. In this study, an analytical procedure based on chromatographic method development and characterization of rhamnolipid sample material by LC-MS as well as a comparison of two sample preparation methods, i.e., liquid-liquid extraction and solid-phase extraction, is presented. Efficient separation was achieved under reversed-phase conditions using a mixed propylphenyl and octadecylsilyl-modified silica gel stationary phase. LC-MS/MS analysis of a supernatant from Pseudomonas putida strain KT2440 pVLT33_rhlABC grown on glucose as sole carbon source and purified by solid-phase extraction revealed a total of 20 congeners of di-rhamnolipids, mono-rhamnolipids, and their biosynthetic precursors 3-(3-hydroxyalkanoyloxy)alkanoic acids (HAAs) with different carbon chain lengths from C8 to C14, including three rhamnolipids with uncommon C9 and C11 fatty acid residues. LC-MS and the orcinol assay were used to evaluate the developed solid-phase extraction method in comparison with the established liquid-liquid extraction. Solid-phase extraction exhibited higher yields and reproducibility as well as lower experimental effort.

  15. Compact streak camera for the shock study of solids by using the high-pressure gas gun

    Science.gov (United States)

    Nagayama, Kunihito; Mori, Yasuhito

    1993-01-01

    For the precise observation of high-speed impact phenomena, a compact high-speed streak camera recording system has been developed. The system consists of a high-pressure gas gun, a streak camera, and a long-pulse dye laser. The gas gun installed in our laboratory has a muzzle of 40 mm in diameter, and a launch tube of 2 m long. Projectile velocity is measured by the laser beam cut method. The gun is capable of accelerating a 27 g projectile up to 500 m/s, if helium gas is used as a driver. The system has been designed on the principal idea that the precise optical measurement methods developed in other areas of research can be applied to the gun study. The streak camera is 300 mm in diameter, with a rectangular rotating mirror which is driven by an air turbine spindle. The attainable streak velocity is 3 mm/microsecond(s) . The size of the camera is rather small aiming at the portability and economy. Therefore, the streak velocity is relatively slower than the fast cameras, but it is possible to use low-sensitivity but high-resolution film as a recording medium. We have also constructed a pulsed dye laser of 25 - 30 microsecond(s) in duration. The laser can be used as a light source of observation. The advantage for the use of the laser will be multi-fold, i.e., good directivity, almost single frequency, and so on. The feasibility of the system has been demonstrated by performing several experiments.

  16. Conductors, semiconductors, superconductors. A compact introduction to history, development, and theory of solid-state physics. 2. ed.

    International Nuclear Information System (INIS)

    Huebener, Rudolf

    2017-01-01

    The present book is a strongly revised and supplemented edition of the title: ''Kristalle: Spiefeld der Elektronen'', published scarcely ten years ago by the same author. Especially the physical contents are explained by the mathematically formulated foundations. The book appeals to students of natural sciences and especially of physics as well as to engineers as introduction to the wide field of solid-state physics, so to speak as motivating prestage to the established and very extensive textbooks. Beside the physical contents the book treats the important role of numerous important and often still very young scientists. By corresponding supplements in this book it is tried to present the fundamental developments in their wide environment.

  17. Solid Sampling with a Diode Laser for Portable Ambient Mass Spectrometry.

    Science.gov (United States)

    Yung, Yeni P; Wickramasinghe, Raveendra; Vaikkinen, Anu; Kauppila, Tiina J; Veryovkin, Igor V; Hanley, Luke

    2017-07-18

    A hand-held diode laser is implemented for solid sampling in portable ambient mass spectrometry (MS). Specifically, a pseudocontinuous wave battery-powered surgical laser diode is employed for portable laser diode thermal desorption (LDTD) at 940 nm and compared with nanosecond pulsed laser ablation at 2940 nm. Postionization is achieved in both cases using atmospheric pressure photoionization (APPI). The laser ablation atmospheric pressure photoionization (LAAPPI) and LDTD-APPI mass spectra of sage leaves (Salvia officinalis) using a field-deployable quadrupole ion trap MS display many similar ion peaks, as do the mass spectra of membrane grown biofilms of Pseudomonas aeruginosa. These results indicate that LDTD-APPI method should be useful for in-field sampling of plant and microbial communities, for example, by portable ambient MS. The feasibility of many portable MS applications is facilitated by the availability of relatively low cost, portable, battery-powered diode lasers. LDTD could also be coupled with plasma- or electrospray-based ionization for the analysis of a variety of solid samples.

  18. A new qualitative pattern classification of shear wave elastograghy for solid breast mass evaluation.

    Science.gov (United States)

    Cong, Rui; Li, Jing; Guo, Song

    2017-02-01

    To examine the efficacy of qualitative shear wave elastography (SWE) in the classification and evaluation of solid breast masses, and to compare this method with conventional ultrasonograghy (US), quantitative SWE parameters and qualitative SWE classification proposed before. From April 2015 to March 2016, 314 consecutive females with 325 breast masses who decided to undergo core needle biopsy and/or surgical biopsy were enrolled. Conventional US and SWE were previously performed in all enrolled subjects. Each mass was classified by two different qualitative classifications. One was established in our study, herein named the Qual1. Qual1 could classify the SWE images into five color patterns by the visual evaluations: Color pattern 1 (homogeneous pattern); Color pattern 2 (comparative homogeneous pattern); Color pattern 3 (irregularly heterogeneous pattern); Color pattern 4 (intralesional echo pattern); and Color pattern 5 (the stiff rim sign pattern). The second qualitative classification was named Qual2 here, and included a four-color overlay pattern classification (Tozaki and Fukuma, Acta Radiologica, 2011). The Breast Imaging Reporting and Data System (BI-RADS) assessment and quantitative SWE parameters were recorded. Diagnostic performances of conventional US, SWE parameters, and combinations of US and SWE parameters were compared. With pathological results as the gold standard, of the 325 examined breast masses, 139 (42.77%) samples were malignant and 186 (57.23%) were benign. The Qual1 showed a higher Az value than the Qual2 and quantitative SWE parameters (all Pbreast mass diagnoses. Copyright © 2016. Published by Elsevier B.V.

  19. Numerical simulation of mass and energy transport phenomena in solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Arpino, F. [Dipartimento di Meccanica, Strutture, Ambiente e Territorio (DiMSAT), University of Cassino, via Di Biasio 43, Cassino (Italy); Massarotti, N. [Dipertimento per le Tecnologie (DiT), University of Naples ' ' Parthenope' ' , Centro Direzionale, isola C4, 80143 Napoli (Italy)

    2009-12-15

    Solid Oxide Fuel Cells (SOFCs) represent a very promising technology for near future energy conversion thanks to a number of advantages, including the possibility of using different fuels. In this paper, a detailed numerical model, based on a general mathematical description and on a finite element Characteristic based Split (CBS) algorithm code is employed to simulate mass and energy transport phenomena in SOFCs. The model predicts the thermodynamic quantity of interest in the fuel cell. Full details of the numerical solution obtained are presented both in terms of heat and mass transfer in the cell and in terms of electro-chemical reactions that occur in the system considered. The results obtained with the present algorithm is compared with the experimental data available in the literature for validation, showing an excellent agreement. (author)

  20. Vaporization study on vanadium-oxygen solid solution by mass spectrometric method

    International Nuclear Information System (INIS)

    Banchorndhevakul, W.; Matsui, Tsuneo; Naito, Keiji

    1986-01-01

    The vapor pressures over vanadium-oxygen solid solution (0.001 ≤ O/V ≤ 0.145) were measured by mass-spectrometric method in the temperature range of 1,855 ∼ 2,117 K. The main vapor species were observed to be V(g) and VO(g). The vapor pressure of V(g) is higher than that of VO(g) over the solid solutions with all O/V ratios except for O/V = 0.145. The vapor pressure of V(g) is nearly independent of O/V ratio. The vapor pressure of VO(g) decreases with decreasing O/V ratio. The oxygen partial pressure was calculated as a function of temperature and O/V ratio from the vapor pressures of V(g) and VO(g), from which the partial molar enthalpy and entropy of oxygen in the solid solution were determined. The partial molar enthalpy of oxygen was observed to be independent of composition, suggesting the presence of very weak interaction between interstitial oxygens. The compositional dependence of the partial molar entropy of oxygen can be explained by assuming the occupation of the octahedral site in bcc vanadium lattice by the interstitial oxygens. The excess partial molar entropy of oxygen was compared with the value derived from the sum of the contributions from the volume expansion, electronic heat capacity and vibrational terms. (author)

  1. Mass spectrometry of solid samples in open air using combined laser ionization and ambient metastable ionization

    International Nuclear Information System (INIS)

    He, X.N.; Xie, Z.Q.; Gao, Y.; Hu, W.; Guo, L.B.; Jiang, L.; Lu, Y.F.

    2012-01-01

    Mass spectrometry of solid samples in open air was carried out using combined laser ionization and metastable ionization time-of-flight mass spectrometry (LI-MI-TOFMS) in ambient environment for qualitative and semiquantitative (relative analyte information, not absolute information) analysis. Ambient metastable ionization using a direct analysis in realtime (DART) ion source was combined with laser ionization time-of-flight mass spectrometry (LI-TOFMS) to study the effects of combining metastable and laser ionization. A series of metallic samples from the National Institute of Standards and Technology (NIST 494, 495, 498, 499, and 500) and a pure carbon target were characterized using LI-TOFMS in open air. LI-MI-TOFMS was found to be superior to laser-induced breakdown spectroscopy (LIBS). Laser pulse energies between 10 and 200 mJ at the second harmonic (532 nm) of an Nd:YAG laser were applied in the experiment to obtain a high degree of ionization in plasmas. Higher laser pulse energy improves signal intensities of trace elements (such as Fe, Cr, Mn, Ni, Ca, Al, and Ag). Data were analyzed by numerically calculating relative sensitivity coefficients (RSCs) and limit of detections (LODs) from mass spectrometry (MS) and LIBS spectra. Different parameters, such as boiling point, ionization potential, RSC, LOD, and atomic weight, were shown to analyze the ionization and MS detection processes in open air.

  2. Protein structural studies by paramagnetic solid-state NMR spectroscopy aided by a compact cyclen-type Cu(II) binding tag

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, Ishita; Gao, Min; Arachchige, Rajith J.; Nadaud, Philippe S. [The Ohio State University, Department of Chemistry and Biochemistry (United States); Cunningham, Timothy F.; Saxena, Sunil [University of Pittsburgh, Department of Chemistry (United States); Schwieters, Charles D. [National Institutes of Health, Center for Information Technology (United States); Jaroniec, Christopher P., E-mail: jaroniec@chemistry.ohio-state.edu [The Ohio State University, Department of Chemistry and Biochemistry (United States)

    2015-01-15

    Paramagnetic relaxation enhancements (PREs) are a rich source of structural information in protein solid-state NMR spectroscopy. Here we demonstrate that PRE measurements in natively diamagnetic proteins are facilitated by a thiol-reactive compact, cyclen-based, high-affinity Cu{sup 2+} binding tag, 1-[2-(pyridin-2-yldisulfanyl)ethyl]-1,4,7,10-tetraazacyclododecane (TETAC), that overcomes the key shortcomings associated with the use of larger, more flexible metal-binding tags. Using the TETAC–Cu{sup 2+} K28C mutant of B1 immunoglobulin-binding domain of protein G as a model, we find that amino acid residues located within ∼10 Å of the Cu{sup 2+} center experience considerable transverse PREs leading to severely attenuated resonances in 2D {sup 15}N–{sup 13}C correlation spectra. For more distant residues, electron–nucleus distances are accessible via quantitative measurements of longitudinal PREs, and we demonstrate such measurements for {sup 15}N–Cu{sup 2+} distances up to ∼20 Å.

  3. Dissolution and compaction instabilities in geomaterials

    Science.gov (United States)

    Stefanou, I.; Sulem, J.; de Sauvage, J.

    2014-12-01

    Compaction bands play an important role in reservoir engineering and geological storage. Their presence in geological formations may also provide useful information on various geological processes. Several mechanisms can be involved at different scales and may be responsible for compaction band instabilities [1]. Compaction bands can be seen as a particular instability of the governing mathematical system leading to localization of deformation [2-4]. In a saturated porous rock, the progressive mechanical damage of the solid skeleton during compaction, results in the increase of the interface area of the reactants and consequently in the acceleration of the dissolution rate of the solid phase [2,5]. Thus, the solid skeleton is degraded more rapidly (mass removal because of dissolution), the overall mechanical properties of the system diminish (contraction of the elastic domain - chemical softening), deformations increase and the solid skeleton is further damaged (intergranular fractures, debonding, breakage of the porous network etc.). The stability of this positive feedback process is investigated analytically through linear stability analysis by considering the strong chemo-poro-mechanical coupling due to chemical dissolution. The post bifurcation behavior is then studied analytically and numerically revealing the compaction band thickness and periodicity. The effect of various parameters is studied as for instance the influence of the hydraulic diffusivity on the compaction band thickness. [1] P. Baud, S. Vinciguerra, C. David, A. Cavallo, E. Walker and T. Reuschlé (2009), Pure Appl. Geophys., 166(5-7), 869-898 [2] I. Stefanou and J. Sulem (2014), JGR: Solid Earth, 119(2), 880-899. doi:10.1002/2013JB010342I [3] J.W. Rudnicki and J.R. Rice (1975), Journal of the Mechanics and Physics of Solids 23(6),: 371-394 [4] K.A. Issen and J.W. Rudnicki (2000), JGR, 105(B9), 21529. doi:10.1029/2000JB900185 [5] R. Nova, R. Castellanza and C. Tamagnini (2003), International

  4. Design of a compact permanent magnet Cyclotron Mass Spectrometer for the detection and measurement of trace isotopes

    International Nuclear Information System (INIS)

    Young, A.T.; Bertsche, K.J.; Clark, D.J.; Halbach, K.; Kunkel, W.B.; Leung, K.N.; Li, C.Y.

    1992-07-01

    A technique for the detection of trace amounts of rare isotopes, Cyclotron mass Spectrometry (CMS), is described. This technique uses the relationships between particle mass, charge, magnetic field strength and cyclotron orbital frequency to provide high mass resolution. The instrument also has high sensitivity and is capable of measuring isotopes with abundances of - 12 . Improvements now being implemented will lead to further increases in the sensitivity and enhance operating parameters such as cost, portability, and sample throughput

  5. Intratumoral Macroscopic Fat and Hemorrhage Combination Useful in the Differentiation of Benign and Malignant Solid Renal Masses.

    Science.gov (United States)

    Sun, Jun; Xing, Zhaoyu; Xing, Wei; Zheng, Linfeng; Chen, Jie; Fan, Min; Chen, Tongbing; Zhang, Zhuoli

    2016-03-01

    To evaluate the value of combining the detection of intratumoral macroscopic fat and hemorrhage in the differentiation of the benign from malignant solid renal masses.Conventional magnetic resonance imaging (MRI), chemical shift (CS)-MRI, and susceptibility-weighted imaging were performed in 152 patients with 152 solid renal masses, including 48 benign and 104 malignant masses all pathologically confirmed. The presence of macroscopic fat detected by CS-MRI and hemorrhage detected by susceptibility-weighted imaging were evaluated in all masses. The rates of macroscopic fat and hemorrhage observed between benign and malignant masses were compared by a χ test. All masses found to contain macroscopic fat with or without hemorrhage were considered to be benign. The remaining masses (without macroscopic fat) found not to contain hemorrhage were considered to be benign. Only those found to contain hemorrhage alone were considered to be malignant. The evaluation indexes for differentiating and forecasting the benign and malignant masses were calculated.Significant differences in the rate of macroscopic fat (observed in 85.42% of benign masses vs. 0% of malignant masses) and hemorrhage (observed in 4.17% of benign masses vs. 95.19% of malignant masses) were measured in the benign and malignant groups (P benign and malignant masses were 96.05%, 95.19%, and 97.92%, respectively, and the accuracy and error rate of forecasting the benign and malignant masses were 95.39% and 4.61%, respectively.Combining the detection intratumoral macroscopic fat and hemorrhage can be used to differentiate the benign from malignant solid renal masses.

  6. Atmospheric measurements of OH, HO2 and NO by laser-induced fluorescence spectroscopy using a compact all solid-state laser system

    Science.gov (United States)

    Bloss, W. J.; Floquet, C.; Gravestock, T. J.; Heard, D. E.; Ingham, T.; Johnson, G. P.; Lee, J. D.

    2003-04-01

    Free-radicals are key intermediates that control the budgets of many trace gases, for example ozone, greenhouse gases and harmful pollutants. Measurement of radicals and comparison with model calculations constitutes an important test of our understanding of the underlying chemistry. There is a greater need for compact and lightweight instruments for the in situ measurement of free-radical species that are suitable for deployment from a number of field-platforms. A new field instrument has been developed that incorporates an all solid-state Nd:YAG pumped titanium sapphire laser that is capable of generating radiation at high pulse-repetition-frequency for the detection of OH, HO_2, NO and IO radicals in the atmosphere by laser induced fluorescence (LIF). The system offers advantages of wide wavelength tunability, compactness, low weight, greater long-term stability (fibre-optic delivery) and short warm-up time. The instrument was successfully deployed during 2002 in the NAMBLEX field campaign at Mace Head with detection limits for OH and HO_2 (measured simultaneously with laser operation at 308 nm) of 3.1 x 10^5 molecule cm-3 (0.012 ppt) and 2.6 x 10^6 molecule cm-3 (0.09 pptv) respectively. Diurnal profiles of OH have been recorded over a period of 5 weeks. NO controls the HO_2/OH ratio and is the critical parameter in the production of tropospheric ozone, yet measurements in the boundary layer are restricted to a single indirect technique based on chemiluminescent analysers. Measurements of NO in the atmosphere have been made by LIF using the new instrument operating at 226 nm, with absolute concentrations in good agreement with simultaneous measurements made using a commercial chemiluminescent analyser. Whilst operating at 445 nm, the instrument has detected the IO radical in the laboratory, with a projected detection limit that is well below previously measured atmospheric concentrations of IO. A second instrument to be deployed on an aircraft platform is

  7. Direct Laser Ablation and Ionization of Solids for Chemical Analysis by Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Holt, J K; Nelson, E J; Klunder, G L [Forensic Science Center, Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States)

    2007-04-15

    A laser ablation/ionization mass spectrometer system is described for the direct chemical analysis of solids. An Nd:YAG laser is used for ablation and ionization of the sample in a quadrupole ion trap operated in an ion-storage (IS) mode that is coupled with a reflectron time-of-flight mass spectrometer (TOF-MS). Single pulse experiments have demonstrated simultaneous detection of up to 14 elements present in glasses in the ppm range. However, detection of the components has produced non-stoichiometric results due to difference in ionization potentials and fractionation effects. Time-of-flight secondary ionization mass spectrometry (TOF-SIMS) was used to spatially map elemental species on the surface and provide further evidence of fractionation effects. Resolution (m/{delta}m) of 1500 and detection limits of approximately 10 pg have been achieved with a single laser pulse. The system configuration and related operating principles for accurately measuring low concentrations of isotopes are described.

  8. Massing in high shear wet granulation can simultaneously improve powder flow and deteriorate powder compaction: a double-edged sword.

    Science.gov (United States)

    Shi, Limin; Feng, Yushi; Sun, Changquan Calvin

    2011-05-18

    The influence of massing during high shear wet granulation (HSWG) process on granule properties and performance was investigated using microcrystalline cellulose (MCC). Massing time varied from 0 to 40 min while other factors were fixed. Granule physical properties, including morphology, size, porosity, and specific surface area (SSA), were characterized. Changes in powder properties were profound in the first 10 min of massing but negligible beyond 10 min. With 10 min of massing, granule tabletability decreased by 75% while flowability increased by 75%. The significantly deteriorated tabletability and improved flowability resulted from dramatic changes in granule morphology, porosity, and SSA. The results confirm that massing time is a key process parameter in HSWG, and it must be carefully evaluated and controlled during process development, scale up, and manufacturing. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. High-temperature, Knudsen cell-mass spectroscopic studies on lanthanum oxide/uranium dioxide solid solutions

    International Nuclear Information System (INIS)

    Sunder, S.; McEachern, R.; LeBlanc, J.C.

    2001-01-01

    Knudsen cell-mass spectroscopic experiments were carried out with lanthanum oxide/uranium oxide solid solutions (1%, 2% and 5% (metal at.% basis)) to assess the volatilization characteristics of rare earths present in irradiated nuclear fuel. The oxidation state of each sample used was conditioned to the 'uranium dioxide stage' by heating in the Knudsen cell under an atmosphere of 10% CO 2 in CO. The mass spectra were analyzed to obtain the vapour pressures of the lanthanum and uranium species. It was found that the vapour pressure of lanthanum oxide follows Henry's law, i.e., its value is directly proportional to its concentration in the solid phase. Also, the vapour pressure of lanthanum oxide over the solid solution, after correction for its concentration in the solid phase, is similar to that of uranium dioxide. (authors)

  10. Some Like it Hot: Linking Diffuse X-Ray Luminosity, Baryonic Mass, and Star Formation Rate in Compact Groups of Galaxies

    Science.gov (United States)

    Desjardins, Tyler D.; Gallagher, Sarah C.; Hornschemeier, Ann E.; Mulchaey, John S.; Walker, Lisa May; Brandt, Willian N.; Charlton, Jane C.; Johnson, Kelsey E.; Tzanavaris, Panayiotis

    2014-01-01

    We present an analysis of the diffuse X-ray emission in 19 compact groups (CGs) of galaxies observed with Chandra. The hottest, most X-ray luminous CGs agree well with the galaxy cluster X-ray scaling relations in L(x-T) and (L(x-sigma), even in CGs where the hot gas is associated with only the brightest galaxy. Using Spitzer photometry, we compute stellar masses and classify Hickson CGs 19, 22, 40, and 42, and RSCGs 32, 44, and 86 as fossil groups using a new definition for fossil systems that includes a broader range of masses. We find that CGs with total stellar and Hi masses are great than or equal to 10(sup (11.3) solar mass are often X-ray luminous, while lower-mass CGs only sometimes exhibit faint, localized X-ray emission. Additionally, we compare the diffuse X-ray luminosity against both the total UV and 24 micron star formation rates of each CG and optical colors of the most massive galaxy in each of the CGs. The most X-ray luminous CGs have the lowest star formation rates, likely because there is no cold gas available for star formation, either because the majority of the baryons in these CGs are in stars or the X-ray halo, or due togas stripping from the galaxies in CGs with hot halos. Finally, the optical colors that trace recent star formation histories of the most massive group galaxies do not correlate with the X-ray luminosities of the CGs, indicating that perhaps the current state of the X-ray halos is independent of the recent history of stellar mass assembly in the most massive galaxies.

  11. Carbon fiber brush electrode as a novel substrate for atmospheric solids analysis probe (ASAP) mass spectrometry: Electrochemical oxidation of brominated phenols.

    Science.gov (United States)

    Skopalová, Jana; Barták, Petr; Bednář, Petr; Tomková, Hana; Ingr, Tomáš; Lorencová, Iveta; Kučerová, Pavla; Papoušek, Roman; Borovcová, Lucie; Lemr, Karel

    2018-01-25

    A carbon fiber brush electrode (CFBE) was newly designed and used as a substrate for both controlled potential electrolysis and atmospheric solids analysis probe (ASAP) mass spectrometry. Electropolymerized and strongly adsorbed products of electrolysis were directly desorbed and ionized from the electrode surface. Electrochemical properties of the electrode investigated by cyclic voltammetry revealed large electroactive surface area (23 ± 3 cm 2 ) at 1.3 cm long array of carbon fibers with diameter 6-9 μm. Some products of electrochemical oxidation of pentabromophenol and 2,4,6-tribromophenol formed a compact layer on the carbon fibers and were analyzed using ASAP. Eleven new oligomeric products were identified including quinones and biphenoquinones. These compounds were not observed previously in electrolyzed solutions by liquid or gas chromatography/mass spectrometry. The thickness around 58 nm and 45 nm of the oxidation products layers deposited on carbon fibers during electrolysis of pentabromophenol and 2,4,6-tribromophenol, respectively, was estimated from atomic force microscopy analysis and confirmed by scanning electron microscopy with energy-dispersive X-ray spectroscopy measurements. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Compact Solid State Terahertz Detectors

    Science.gov (United States)

    2007-07-09

    by the optical features mnH (L) that could be associated with excitonic transitions in the MQW region of the samples. The notation mnH (L) signifies...originating due to internal electric fields in the samples [1, 2]. In addition to the FKOs, at higher energies, a number of mnH (L) features...associated with the excitonic transitions in the MQW region of the samples are observed. The notation mnH (L) signifies here the transitions between the m

  13. Pore-scale investigation of mass transport and electrochemistry in a solid oxide fuel cell anode

    Energy Technology Data Exchange (ETDEWEB)

    Grew, Kyle N.; Joshi, Abhijit S.; Peracchio, Aldo A.; Chiu, Wilson K.S. [Department of Mechanical Engineering, University of Connecticut, 191 Auditorium Road, Storrs, CT 06269-3139 (United States)

    2010-04-15

    The development and validation of a model for the study of pore-scale transport phenomena and electrochemistry in a Solid Oxide Fuel Cell (SOFC) anode are presented in this work. This model couples mass transport processes with a detailed reaction mechanism, which is used to model the electrochemical oxidation kinetics. Detailed electrochemical oxidation reaction kinetics, which is known to occur in the vicinity of the three-phase boundary (TPB) interfaces, is discretely considered in this work. The TPB regions connect percolating regions of electronic and ionic conducting phases of the anode, nickel (Ni) and yttria-stabilized zirconia (YSZ), respectively; with porous regions supporting mass transport of the fuel and product. A two-dimensional (2D), multi-species lattice Boltzmann method (LBM) is used to describe the diffusion process in complex pore structures that are representative of the SOFC anode. This diffusion model is discretely coupled to a kinetic electrochemical oxidation mechanism using localized flux boundary conditions. The details of the oxidation kinetics are prescribed as a function of applied activation overpotential and the localized hydrogen and water mole fractions. This development effort is aimed at understanding the effects of the anode microstructure within TPB regions. This work describes the methods used so that future studies can consider the details of SOFC anode microstructure. (author)

  14. All-solid-state deep ultraviolet laser for single-photon ionization mass spectrometry.

    Science.gov (United States)

    Yuan, Chengqian; Liu, Xianhu; Zeng, Chenghui; Zhang, Hanyu; Jia, Meiye; Wu, Yishi; Luo, Zhixun; Fu, Hongbing; Yao, Jiannian

    2016-02-01

    We report here the development of a reflectron time-of-flight mass spectrometer utilizing single-photon ionization based on an all-solid-state deep ultraviolet (DUV) laser system. The DUV laser was achieved from the second harmonic generation using a novel nonlinear optical crystal KBe2BO3F2 under the condition of high-purity N2 purging. The unique property of this laser system (177.3-nm wavelength, 15.5-ps pulse duration, and small pulse energy at ∼15 μJ) bears a transient low power density but a high single-photon energy up to 7 eV, allowing for ionization of chemicals, especially organic compounds free of fragmentation. Taking this advantage, we have designed both pulsed nanospray and thermal evaporation sources to form supersonic expansion molecular beams for DUV single-photon ionization mass spectrometry (DUV-SPI-MS). Several aromatic amine compounds have been tested revealing the fragmentation-free performance of the DUV-SPI-MS instrument, enabling applications to identify chemicals from an unknown mixture.

  15. Solid-Gas Coupling Model for Coal-Rock Mass Deformation and Pressure Relief Gas Flow in Protection Layer Mining

    OpenAIRE

    Zhu, Zhuohui; Feng, Tao; Yuan, Zhigang; Xie, Donghai; Chen, Wei

    2018-01-01

    The solid-gas coupling model for mining coal-rock mass deformation and pressure relief gas flow in protection layer mining is the key to determine deformation of coal-rock mass and migration law of pressure relief gas of protection layer mining in outburst coal seams. Based on the physical coupling process between coal-rock mass deformation and pressure-relief gas migration, the coupling variable of mining coal-rock mass, a part of governing equations of gas seepage field and deformation fiel...

  16. Mouse Embryo Compaction.

    Science.gov (United States)

    White, M D; Bissiere, S; Alvarez, Y D; Plachta, N

    2016-01-01

    Compaction is a critical first morphological event in the preimplantation development of the mammalian embryo. Characterized by the transformation of the embryo from a loose cluster of spherical cells into a tightly packed mass, compaction is a key step in the establishment of the first tissue-like structures of the embryo. Although early investigation of the mechanisms driving compaction implicated changes in cell-cell adhesion, recent work has identified essential roles for cortical tension and a compaction-specific class of filopodia. During the transition from 8 to 16 cells, as the embryo is compacting, it must also make fundamental decisions regarding cell position, polarity, and fate. Understanding how these and other processes are integrated with compaction requires further investigation. Emerging imaging-based techniques that enable quantitative analysis from the level of cell-cell interactions down to the level of individual regulatory molecules will provide a greater understanding of how compaction shapes the early mammalian embryo. © 2016 Elsevier Inc. All rights reserved.

  17. A new qualitative pattern classification of shear wave elastograghy for solid breast mass evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Cong, Rui, E-mail: congrui2684@163.com; Li, Jing, E-mail: lijing@sj-hospital.org; Guo, Song, E-mail: 21751735@qq.com

    2017-02-15

    Highlights: • Qualitative SWE classification proposed here was significantly better than quantitative SWE parameters. • Qualitative classification proposed here was better than the classification proposed before. • Qualitative classification proposed here could obtain higher specificity without a loss of sensitivity. - Abstract: Objectives: To examine the efficacy of qualitative shear wave elastography (SWE) in the classification and evaluation of solid breast masses, and to compare this method with conventional ultrasonograghy (US), quantitative SWE parameters and qualitative SWE classification proposed before. Methods: From April 2015 to March 2016, 314 consecutive females with 325 breast masses who decided to undergo core needle biopsy and/or surgical biopsy were enrolled. Conventional US and SWE were previously performed in all enrolled subjects. Each mass was classified by two different qualitative classifications. One was established in our study, herein named the Qual1. Qual1 could classify the SWE images into five color patterns by the visual evaluations: Color pattern 1 (homogeneous pattern); Color pattern 2 (comparative homogeneous pattern); Color pattern 3 (irregularly heterogeneous pattern); Color pattern 4 (intralesional echo pattern); and Color pattern 5 (the stiff rim sign pattern). The second qualitative classification was named Qual2 here, and included a four-color overlay pattern classification (Tozaki and Fukuma, Acta Radiologica, 2011). The Breast Imaging Reporting and Data System (BI-RADS) assessment and quantitative SWE parameters were recorded. Diagnostic performances of conventional US, SWE parameters, and combinations of US and SWE parameters were compared. Results: With pathological results as the gold standard, of the 325 examined breast masses, 139 (42.77%) samples were malignant and 186 (57.23%) were benign. The Qual1 showed a higher Az value than the Qual2 and quantitative SWE parameters (all P < 0.05). When applying Qual1

  18. A new qualitative pattern classification of shear wave elastograghy for solid breast mass evaluation

    International Nuclear Information System (INIS)

    Cong, Rui; Li, Jing; Guo, Song

    2017-01-01

    Highlights: • Qualitative SWE classification proposed here was significantly better than quantitative SWE parameters. • Qualitative classification proposed here was better than the classification proposed before. • Qualitative classification proposed here could obtain higher specificity without a loss of sensitivity. - Abstract: Objectives: To examine the efficacy of qualitative shear wave elastography (SWE) in the classification and evaluation of solid breast masses, and to compare this method with conventional ultrasonograghy (US), quantitative SWE parameters and qualitative SWE classification proposed before. Methods: From April 2015 to March 2016, 314 consecutive females with 325 breast masses who decided to undergo core needle biopsy and/or surgical biopsy were enrolled. Conventional US and SWE were previously performed in all enrolled subjects. Each mass was classified by two different qualitative classifications. One was established in our study, herein named the Qual1. Qual1 could classify the SWE images into five color patterns by the visual evaluations: Color pattern 1 (homogeneous pattern); Color pattern 2 (comparative homogeneous pattern); Color pattern 3 (irregularly heterogeneous pattern); Color pattern 4 (intralesional echo pattern); and Color pattern 5 (the stiff rim sign pattern). The second qualitative classification was named Qual2 here, and included a four-color overlay pattern classification (Tozaki and Fukuma, Acta Radiologica, 2011). The Breast Imaging Reporting and Data System (BI-RADS) assessment and quantitative SWE parameters were recorded. Diagnostic performances of conventional US, SWE parameters, and combinations of US and SWE parameters were compared. Results: With pathological results as the gold standard, of the 325 examined breast masses, 139 (42.77%) samples were malignant and 186 (57.23%) were benign. The Qual1 showed a higher Az value than the Qual2 and quantitative SWE parameters (all P < 0.05). When applying Qual1

  19. EFFECTS OF ROTATIONALLY INDUCED MIXING IN COMPACT BINARY SYSTEMS WITH LOW-MASS SECONDARIES AND IN SINGLE SOLAR-TYPE STARS

    International Nuclear Information System (INIS)

    Chatzopoulos, E.; Robinson, Edward L.; Wheeler, J. Craig

    2012-01-01

    Many population synthesis and stellar evolution studies have addressed the evolution of close binary systems in which the primary is a compact remnant and the secondary is filling its Roche lobe, thus triggering mass transfer. Although tidal locking is expected in such systems, most studies have neglected the rotationally induced mixing that may occur. Here we study the possible effects of mixing in mass-losing stars for a range of secondary star masses and metallicities. We find that tidal locking can induce rotational mixing prior to contact and thus affect the evolution of the secondary star if the effects of the Spruit-Tayler dynamo are included both for angular momentum and chemical transport. Once contact is made, the effect of mass transfer tends to be more rapid than the evolutionary timescale, so the effects of mixing are no longer directly important, but the mass-transfer strips matter to inner layers that may have been affected by the mixing. These effects are enhanced for secondaries of 1-1.2 M ☉ and for lower metallicities. We discuss the possible implications for the paucity of carbon in the secondaries of the cataclysmic variable SS Cyg and the black hole candidate XTE J1118+480 and for the progenitor evolution of Type Ia supernovae. We also address the issue of the origin of blue straggler stars in globular and open clusters. We find that for models that include rotation consistent with that observed for some blue straggler stars, evolution is chemically homogeneous. This leads to tracks in the H-R diagram that are brighter and bluer than the non-rotating main-sequence turn-off point. Rotational mixing could thus be one of the factors that contribute to the formation of blue stragglers.

  20. Effect of Mass Proportion of Municipal Solid Waste Incinerator Bottom Ash Layer to Municipal Solid Waste Layer on the Cu and Zn Discharge from Landfill

    Science.gov (United States)

    Kong, Qingna; Qiu, Zhanhong; Shen, Dongsheng

    2016-01-01

    Municipal solid waste incinerator (MSWI) bottom ash is often used as the protection layer for the geomembrane and intermediate layer in the landfill. In this study, three sets of simulated landfills with different mass proportion of MSWI bottom ash layer to municipal solid waste (MSW) layer were operated. Cu and Zn concentrations in the leachates and MSW were monitored to investigate the effect of MSWI bottom ash layer on the Cu and Zn discharge from the landfill. The results showed that the Zn discharge was dependent on the mass proportion of MSWI bottom ash layer. The pH of landfill was not notably increased when the mass proportion of MSWI bottom ash layer to MSW layer was 1 : 9, resulting in the enhancement of the Zn discharge. However, Zn discharge was mitigated when the mass proportion was 2 : 8, as the pH of landfill was notably promoted. The discharge of Cu was not dependent on the mass proportion, due to the great affinity of Cu to organic matter. Moreover, Cu and Zn contents of the sub-MSW layer increased due to the MSWI bottom ash layer. Therefore, the MSWI bottom ash layer can increase the potential environmental threat of the landfill. PMID:28044139

  1. Effect of Mass Proportion of Municipal Solid Waste Incinerator Bottom Ash Layer to Municipal Solid Waste Layer on the Cu and Zn Discharge from Landfill.

    Science.gov (United States)

    Kong, Qingna; Yao, Jun; Qiu, Zhanhong; Shen, Dongsheng

    2016-01-01

    Municipal solid waste incinerator (MSWI) bottom ash is often used as the protection layer for the geomembrane and intermediate layer in the landfill. In this study, three sets of simulated landfills with different mass proportion of MSWI bottom ash layer to municipal solid waste (MSW) layer were operated. Cu and Zn concentrations in the leachates and MSW were monitored to investigate the effect of MSWI bottom ash layer on the Cu and Zn discharge from the landfill. The results showed that the Zn discharge was dependent on the mass proportion of MSWI bottom ash layer. The pH of landfill was not notably increased when the mass proportion of MSWI bottom ash layer to MSW layer was 1 : 9, resulting in the enhancement of the Zn discharge. However, Zn discharge was mitigated when the mass proportion was 2 : 8, as the pH of landfill was notably promoted. The discharge of Cu was not dependent on the mass proportion, due to the great affinity of Cu to organic matter. Moreover, Cu and Zn contents of the sub-MSW layer increased due to the MSWI bottom ash layer. Therefore, the MSWI bottom ash layer can increase the potential environmental threat of the landfill.

  2. SIMULATION OF THE FORCE INTERACTION OF THE SOIL COMPACTING DISK MOVING ALONG A RHEOLOGICAL BEAM THAT HAS DISTRIBUTED MASS

    Directory of Open Access Journals (Sweden)

    Pavlov Georgiy Vasil'evich

    2012-10-01

    Full Text Available The authors describe an original solution to the new problem of a soil compacting disk moving along a rheological beam (Kelvin model in the proposed paper. The motion of the mechanical system that is composed of a disk and a rheological beam is described by a hybrid system of differential equations consisting of an integral-differential equation that stands for the interaction of the beam with a moving disk and Lagrange equations describing the pattern of the disk motion. These equations are considered as equations of nonholonomic links. The problem is solved through the employment of simplifying prerequisites and by determining the operating condition of the disk. Condition of uniform and uniformly variable motions is considered as an opportunity to integrate the equation of beam vibrations regardless of the system of equations describing the disk motion pattern. The solution to the equation in partial derivatives is found through the employment of the Fourier method of separation of variables coupled with the Laplace integral transformation method. The solution to the problem of constrained vibrations was implemented as a series of homogenous problems with zero initial and boundary conditions. The equation describing changes in the time function is reduced to its standard form, and thereafter the solution is found through the employment of asymptotic methods. Disk motion stability is assessed through the employment of the first approximation method. The motion of the disk is stable. As a result of the analysis of patterns of dependencies between beam deformations and the time period, the conclusion of feasibility of a stable pattern of forced vibrations of a rheological beam, supported by a driving force and a variable friction force, caused by the slightly elastic field of the beam material, is made by the authors.

  3. On mass in 4π solid angle around song CsI scintillator aboard coronas-I satellite

    International Nuclear Information System (INIS)

    Bucik, R.; Kudela, K.

    2003-01-01

    The complex geometric setup around the SONG CsI scintillator aboard the CORONAS-1 satellite has been modelled, to evaluate the mass thickness passed through by the cosmic ray particle striking the detector. The analytic functional form giving the amount of matter traversed in absorbers for an arbitrary incident directions is present. The population mean and variance of the mass thickness are estimated by random sampling of the uniformly distributed particle trajectories in the several solid angles (Authors)

  4. Quantitative shear wave ultrasound elastography: initial experience in solid breast masses.

    Science.gov (United States)

    Evans, Andrew; Whelehan, Patsy; Thomson, Kim; McLean, Denis; Brauer, Katrin; Purdie, Colin; Jordan, Lee; Baker, Lee; Thompson, Alastair

    2010-01-01

    Shear wave elastography is a new method of obtaining quantitative tissue elasticity data during breast ultrasound examinations. The aims of this study were (1) to determine the reproducibility of shear wave elastography (2) to correlate the elasticity values of a series of solid breast masses with histological findings and (3) to compare shear wave elastography with greyscale ultrasound for benign/malignant classification. Using the Aixplorer® ultrasound system (SuperSonic Imagine, Aix en Provence, France), 53 solid breast lesions were identified in 52 consecutive patients. Two orthogonal elastography images were obtained of each lesion. Observers noted the mean elasticity values in regions of interest (ROI) placed over the stiffest areas on the two elastography images and a mean value was calculated for each lesion. A sub-set of 15 patients had two elastography images obtained by an additional operator. Reproducibility of observations was assessed between (1) two observers analysing the same pair of images and (2) findings from two pairs of images of the same lesion taken by two different operators. All lesions were subjected to percutaneous biopsy. Elastography measurements were correlated with histology results. After preliminary experience with 10 patients a mean elasticity cut off value of 50 kilopascals (kPa) was selected for benign/malignant differentiation. Greyscale images were classified according to the American College of Radiology (ACR) Breast Imaging Reporting and Data System (BI-RADS). BI-RADS categories 1-3 were taken as benign while BI-RADS categories 4 and 5 were classified as malignant. Twenty-three benign lesions and 30 cancers were diagnosed on histology. Measurement of mean elasticity yielded an intraclass correlation coefficient of 0.99 for two observers assessing the same pairs of elastography images. Analysis of images taken by two independent operators gave an intraclass correlation coefficient of 0.80. Shear wave elastography versus

  5. THE STELLAR VELOCITY DISPERSION OF A COMPACT MASSIVE GALAXY AT z = 1.80 USING X-SHOOTER: CONFIRMATION OF THE EVOLUTION IN THE MASS-SIZE AND MASS-DISPERSION RELATIONS ,

    International Nuclear Information System (INIS)

    Van de Sande, Jesse; Franx, Marijn; Labbe, Ivo; Kriek, Mariska; Van Dokkum, Pieter G.; Bezanson, Rachel; Whitaker, Katherine E.; Brammer, Gabriel; Groot, Paul J.; Kaper, Lex

    2011-01-01

    Recent photometric studies have shown that early-type galaxies at fixed stellar mass were smaller and denser at earlier times. In this Letter, we assess that finding by deriving the dynamical mass of such a compact quiescent galaxy at z = 1.8. We have obtained a high-quality spectrum with full UV-NIR wavelength coverage of galaxy NMBS-C7447 using X-Shooter on the Very Large Telescope. We determined a velocity dispersion of 294 ± 51 km s -1 . Given this velocity dispersion and the effective radius of 1.64 ± 0.15 kpc (as determined from Hubble Space Telescope Wide Field Camera 3 F160W observations) we derive a dynamical mass of (1.7 ± 0.5) x 10 11 M sun . Comparison of the full spectrum with stellar population synthesis models indicates that NMBS-C774 has a relatively young stellar population (0.40 Gyr) with little or no star formation and a stellar mass of M * ∼ 1.5 x 10 11 M sun . The dynamical and photometric stellar masses are in good agreement. Thus, our study supports the conclusion that the mass densities of quiescent galaxies were indeed higher at earlier times, and this earlier result is not caused by systematic measurement errors. By combining available spectroscopic measurements at different redshifts, we find that the velocity dispersion at fixed dynamical mass was a factor of ∼1.8 higher at z = 1.8 compared with z = 0. Finally, we show that the apparent discrepancies between the few available velocity dispersion measurements at z > 1.5 are consistent with the intrinsic scatter of the mass-size relation.

  6. Solid phase extraction for removal of matrix effects in lipophilic marine toxin analysis by liquid chromatography-tandem mass spectrometry

    NARCIS (Netherlands)

    Gerssen, A.; McElhinney, M.; Mulder, P.P.J.; Bire, R.; Hess, P.; Boer, de J.

    2009-01-01

    The potential of solid phase extraction (SPE) clean-up has been assessed to reduce matrix effects (signal suppression or enhancement) in the liquid chromatography-tandem mass spectrometry (LC¿MS/MS) analysis of lipophilic marine toxins. A large array of ion-exchange, silica-based, and mixed-function

  7. Solid phase extraction for removal of matrix effects in lipophilic marine toxin analysis by liquid chromatography-tandem mass spectrometry

    NARCIS (Netherlands)

    Gerssen, A.; McElhinney, A. M.; Mulder, P.P.J.; Bire, L.; Hess, P.; de Boer, J.

    2009-01-01

    The potential of solid phase extraction (SPE) clean-up has been assessed to reduce matrix effects (signal suppression or enhancement) in the liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of lipophilic marine toxins. A large array of ion-exchange, silica-based, and mixed-function

  8. Generic solid phase extraction-liquid chromatography-tandem mass spectrometry method for fast determination of drugs in biological fluids

    NARCIS (Netherlands)

    Schellen, A.; Ooms, B.; Lagemaat, D. van de; Vreeken, R.; Dongen, W.D. van

    2003-01-01

    A generic method was developed for the fast determination of a wide range of drugs in serum or plasma. The methodology comprises generic solid-phase extraction, on-line coupled to gradient HPLC with tandem mass spectrometric detection (SPE-LC-MS/MS). The individual components of the SPE-LC-MS/MS

  9. A New Approach to Determine the Density of Liquids and Solids without Measuring Mass and Volume: Introducing the "Solidensimeter"

    Science.gov (United States)

    Kiriktas, Halit; Sahin, Mehmet; Eslek, Sinan; Kiriktas, Irem

    2018-01-01

    This study aims to design a mechanism with which the density of any solid or liquid can be determined without measuring its mass and volume in order to help students comprehend the concept of density more easily. The "solidensimeter" comprises of two scaled and nested glass containers (graduated cylinder or beaker) and sufficient water.…

  10. THE LUMINOSITY, MASS, AND AGE DISTRIBUTIONS OF COMPACT STAR CLUSTERS IN M83 BASED ON HUBBLE SPACE TELESCOPE/WIDE FIELD CAMERA 3 OBSERVATIONS

    International Nuclear Information System (INIS)

    Chandar, Rupali; Whitmore, Bradley C.; Mutchler, Max; Bond, Howard; Kim, Hwihyun; Kaleida, Catherine; Calzetti, Daniela; Saha, Abhijit; O'Connell, Robert; Balick, Bruce; Carollo, Marcella; Disney, Michael; Dopita, Michael A.; Frogel, Jay A.; Hall, Donald; Holtzman, Jon A.; Kimble, Randy A.; McCarthy, Patrick; Paresce, Francesco; Silk, Joe

    2010-01-01

    The newly installed Wide Field Camera 3 (WFC3) on the Hubble Space Telescope has been used to obtain multi-band images of the nearby spiral galaxy M83. These new observations are the deepest and highest resolution images ever taken of a grand-design spiral, particularly in the near-ultraviolet, and allow us to better differentiate compact star clusters from individual stars and to measure the luminosities of even faint clusters in the U band. We find that the luminosity function (LF) for clusters outside of the very crowded starburst nucleus can be approximated by a power law, dN/dL ∝ L α , with α = -2.04 ± 0.08, down to M V ∼ -5.5. We test the sensitivity of the LF to different selection techniques, filters, binning, and aperture correction determinations, and find that none of these contribute significantly to uncertainties in α. We estimate ages and masses for the clusters by comparing their measured UBVI, Hα colors with predictions from single stellar population models. The age distribution of the clusters can be approximated by a power law, dN/dτ ∝ τ γ , with γ = -0.9 ± 0.2, for M ∼> few x 10 3 M sun and τ ∼ 8 yr. This indicates that clusters are disrupted quickly, with ∼80%-90% disrupted each decade in age over this time. The mass function of clusters over the same M-τ range is a power law, dN/dM ∝ M β , with β = -1.94 ± 0.16, and does not have bends or show curvature at either high or low masses. Therefore, we do not find evidence for a physical upper mass limit, M C , or for the earlier disruption of lower mass clusters when compared with higher mass clusters, i.e., mass-dependent disruption. We briefly discuss these implications for the formation and disruption of the clusters.

  11. Magnetic solid phase extraction and gas chromatography-mass spectrometrical analysis of sixteen polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Cai, Ying; Yan, Zhihong; NguyenVan, Manh; Wang, Lijia; Cai, Qingyun

    2015-08-07

    Fluorenyl functionalized superparamagnetic core/shell magnetic nanoparticles (MNPs, Fe3O4@SiO2@Flu) were prepared and characterized by transmission electron microscope, X-ray diffraction and infrared spectroscopy. The MNPs having an average diameter of 200nm were then used as solid-phase extraction sorbent for the determination of 16 priority pollutants polycyclic aromatic hydrocarbons (PAHs) in water samples designated by United States Environmental Protection Agency (U.S. EPA). The main influencing parameters, including sorbent amount, desorption solvent, sample volume and extraction time were optimized. Analyses were performed on gas chromatography-mass spectrometry (GC-MS) using selected ion monitoring (SIM) mode. Method validation proved the feasibility of the developed sorbents for the quantitation of the investigated analytes at trace levels. Limit of detection ranging from 0.5 to 4.0ng/L were obtained. The repeatability was investigated by evaluating the intra- and inter-day precisions with relative standard deviations (RSDs) lower than 13.1%. Finally, the proposed method was successfully applied for the determination of PAHs in water samples with the recoveries in the range of 96.0-106.7%. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Identification and fingerprinting of biodiesel blends by solid phase extraction and gas chromatography-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Z. [Environment Canada, Ottawa, ON (Canada). Emergencies Science and Technology Section, Emergencies, Operational Analytical Laboratories and Research Support Division; China Univ. of Geosciences, Wuhan (China). School of Environmental Studies; Hollebone, B.; Wang, Z.; Yang, C.; Landriault, M. [Environment Canada, Ottawa, ON (Canada). Emergencies Science and Technology Section, Emergencies, Operational Analytical Laboratories and Research Support Division

    2009-07-01

    Interest in biodiesel as a replacement for petroleum diesel fuel is growing. In North America, biodiesels are produced by the methyl esterification of plant and animal triglycerides, resulting in complex mixtures composed of fatty acid methyl esters (FAMEs). It is important for both environmental forensic and remediation purposes to determine diesel and biodiesel origins, and the biodiesel content when it is blended with conventional petroleum diesel. This paper reported on a study that combined 2 methods to determine biodiesel levels in blended fuels. Micro-column fractionation of FAMEs involving solid phase extraction (SPE) was combined with gas chromatography-mass spectrometry (GC/MS) to achieve detailed chemical fingerprinting of blends, including the identification and quantification of individual aliphatic hydrocarbons, aromatic hydrocarbons, fatty acid alkyl esters, and free sterols. Fractionation of the fuel samples was optimized for separation of fatty acid esters, free sterols from petroleum hydrocarbons into 4 fractions, notably aliphatic, aromatic, fatty-acid ester and polar components. A sum of the FAME components was used to determine an unknown blend level in freshly-prepared samples. This study showed that this method has great potential for identifying biodiesel in diesel fuel blends and could form the basis of a method for biodiesel-contaminated environmental samples. 28 refs., 5 tabs., 4 figs.

  13. Identification and fingerprinting of biodiesel blends by solid phase extraction and gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    Yang, Z.; China Univ. of Geosciences, Wuhan; Hollebone, B.; Wang, Z.; Yang, C.; Landriault, M.

    2009-01-01

    Interest in biodiesel as a replacement for petroleum diesel fuel is growing. In North America, biodiesels are produced by the methyl esterification of plant and animal triglycerides, resulting in complex mixtures composed of fatty acid methyl esters (FAMEs). It is important for both environmental forensic and remediation purposes to determine diesel and biodiesel origins, and the biodiesel content when it is blended with conventional petroleum diesel. This paper reported on a study that combined 2 methods to determine biodiesel levels in blended fuels. Micro-column fractionation of FAMEs involving solid phase extraction (SPE) was combined with gas chromatography-mass spectrometry (GC/MS) to achieve detailed chemical fingerprinting of blends, including the identification and quantification of individual aliphatic hydrocarbons, aromatic hydrocarbons, fatty acid alkyl esters, and free sterols. Fractionation of the fuel samples was optimized for separation of fatty acid esters, free sterols from petroleum hydrocarbons into 4 fractions, notably aliphatic, aromatic, fatty-acid ester and polar components. A sum of the FAME components was used to determine an unknown blend level in freshly-prepared samples. This study showed that this method has great potential for identifying biodiesel in diesel fuel blends and could form the basis of a method for biodiesel-contaminated environmental samples. 28 refs., 5 tabs., 4 figs.

  14. Solid-phase microextraction gas chromatography-mass spectrometry determination of fragrance allergens in baby bathwater.

    Science.gov (United States)

    Lamas, J Pablo; Sanchez-Prado, Lucia; Garcia-Jares, Carmen; Llompart, Maria

    2009-07-01

    A method based on solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) has been optimized for the determination of fragrance allergens in water samples. This is the first study devoted to this family of cosmetic ingredients performed by SPME. The influence of parameters such as fibre coating, extraction and desorption temperatures, salting-out effect and sampling mode on the extraction efficiency has been studied by means of a mixed-level factorial design, which allowed the study of the main effects as well as two-factor interactions. Excluding desorption temperature, the other parameters were, in general, very important for the achievement of high response. The final procedure was based on headspace sampling at 100 degrees C, using polydimethylsiloxane/divinylbenzene fibres. The method showed good linearity and precision for all compounds, with detection limits ranging from 0.001 to 0.3 ng mL(-1). Reliability was demonstrated through the evaluation of the recoveries in different real water samples, including baby bathwater and swimming pool water. The absence of matrix effects allowed the use of external standard calibration to quantify the target compounds in the samples. The proposed procedure was applied to the determination of allergens in several real samples. All the target compounds were found in the samples, and, in some cases, at quite high concentrations. The presence and the levels of these chemicals in baby bathwater should be a matter of concern.

  15. Quantification of VX Nerve Agent in Various Food Matrices by Solid-Phase Extraction Ultra-Performance Liquid ChromatographyTime-of-Flight Mass Spectrometry

    Science.gov (United States)

    2016-04-01

    QUANTIFICATION OF VX NERVE AGENT IN VARIOUS FOOD MATRICES BY SOLID - PHASE EXTRACTION ULTRA-PERFORMANCE...TITLE AND SUBTITLE Quantification of VX Nerve Agent in Various Food Matrices by Solid - Phase Extraction Ultra-Performance Liquid Chromatography...QUANTIFICATION OF VX NERVE AGENT IN VARIOUS FOOD MATRICES BY SOLID - PHASE EXTRACTION ULTRA-PERFORMANCE LIQUID CHROMATOGRAPHY–TIME-OF-FLIGHT MASS

  16. Super compacting of drums with dry solid radioactive waste in the nuclear power plant of Laguna Verde;Super compactacion de bidones con desecho radiactivo solido seco en la central nucleo electrica Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez G, R.; Lara H, M. A.; Cabrera Ll, M.; Verdalet de la Torre, O., E-mail: marco.lara@cfe.gob.m [Comision Federal de Electricidad, Central Nucleoelectrica de Laguna Verde, Carretera Nautla-Cardel Km. 42.5, Alto Lucero, Veracruz (Mexico)

    2009-10-15

    The nuclear power plant of Laguna Verde located in the Gulf of Mexico, completes in this 2009, nineteen years to produce by nuclear means 4.78% of the electric power that Mexico requires daily. During this time, the Unit 1 has generated more of 88.85 million mega watt-hour and the Unit 2 more of 69.48 million mega watt-hour with an availability average of 83.55%. Derived of their operation cycles, the nuclear power plant has generated (as any other installation of its type) radioactive wastes of low activity that at the moment are temporarily stored in the site. Due to the life cycle of the nuclear power plant, actually has become necessary to begin a project series focused to continue guaranteeing the storage of these wastes, guarantee that is a license requirement for the operation of this nuclear installation before the National Commission of Nuclear Security and Safeguards. The Federal Commission of Electricity beginning a project that allows continue guaranteeing space of sufficient storage for the wastes that the nuclear power plant of Laguna Verde could generate for the rest of its useful life, this project consisted on a process of physical volume reduction of dry solid radioactive wastes denominated super compacting, it has made possible to reduce the volume that these wastes occupy in the temporary storage noted Dry Solid Radioactive Wastes Deposit located inside the site that occupies the nuclear power plant of Laguna Verde. This work presents the super compacting results, as well as a description of the realization of this task until concluding with the super compacting of 5,854 drums with dry solid radioactive waste of low activity. We will enunciate which were the radiological controls that the Department of Radiological Protection of the nuclear power plant of Laguna Verde applied to this work that was realized for first time in Mexico and the nuclear power plant. (Author)

  17. Hairy foam: carbon nanofibers on solid foam as catalyst support : synthesis, mass transfer, and reactor modeling

    NARCIS (Netherlands)

    Wenmakers, P.W.A.M.

    2010-01-01

    The chemical reactor is at the heart of many chemical processes. The chemical industry strives for the most efficient, most compact, and safest chemical reactor. The efficiency of a chemical reactor is determined by the delicate balance of catalyst performance (i.e. selectivity and activity) and the

  18. In-situ Mass Spectrometric Determination of Molecular Structural Evolution at the Solid Electrolyte Interphase in Lithium-Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Zihua; Zhou, Yufan; Yan, Pengfei; Vemuri, Venkata Rama Ses; Xu, Wu; Zhao, Rui; Wang, Xuelin; Thevuthasan, Suntharampillai; Baer, Donald R.; Wang, Chong M.

    2015-08-19

    Dynamic molecular evolution at solid/liquid electrolyte interface is always a mystery for a rechargeable battery due to the challenge to directly probe/observe the solid/liquid interface under reaction conditions, which in essence appears to be similarly true for all the fields involving solid/liquid phases, such as electrocatalysis, electrodeposition, biofuel conversion, biofilm, and biomineralization, We use in-situ liquid secondary ion mass spectroscopy (SIMS) for the first time to directly observe the molecular structural evolution at the solid electrode/liquid electrolyte interface for a lithium (Li)-ion battery under dynamic operating conditions. We have discovered that the deposition of Li metal on copper electrode leads to the condensation of solvent molecules around the electrode. Chemically, this layer of solvent condensate tends to deplete the salt anion and with low concentration of Li+ ions, which essentially leads to the formation of a lean electrolyte layer adjacent to the electrode and therefore contributes to the overpotential of the cell. This unprecedented molecular level dynamic observation at the solid electrode/liquid electrolyte interface provides vital chemical information that is needed for designing of better battery chemistry for enhanced performance, and ultimately opens new avenues for using liquid SIMS to probe molecular evolution at solid/liquid interface in general.

  19. Combination of short-length TiO_2 nanorod arrays and compact PbS quantum-dot thin films for efficient solid-state quantum-dot-sensitized solar cells

    International Nuclear Information System (INIS)

    Zhang, Zhengguo; Shi, Chengwu; Chen, Junjun; Xiao, Guannan; Li, Long

    2017-01-01

    Graphical abstract: The TiO_2 nanorod array with the length of 600 nm, the diameter of 20 nm, the areal density of 500 μm"−"2 was successfully prepared. The compact PbS quantum-dot thin film was firstly obtained on the TiO_2 nanorod array by spin-coating-assisted successive ionic layer absorption and reaction with using 1,2-ethanedithiol. The photoelectric conversion efficiency (PCE) of the compact PbS quantum-dot thin film sensitized solar cells achieved 4.10% using spiro-OMeTAD as a hole transporting layer, while the PCE of the PbS quantum-dot sensitized solar cells was only 0.54%. - Highlights: • Preparation of TiO_2 nanorod arrays with the length of 600 nm, diameter of 20 nm. • The compact PbS QD thin film and short-length TiO_2 nanorod array were combined. • EDT addition improved PbS nanoparticle coverage and photovoltaic performance. • The compact PbS QD thin film sensitized solar cell achieved the PCE of 4.10%. - Abstract: Considering the balance of the hole diffusion length and the loading quantity of quantum-dots, the rutile TiO_2 nanorod array with the length of 600 nm, the diameter of 20 nm, and the areal density of 500 μm"−"2 is successfully prepared by the hydrothermal method using the aqueous grown solution of 38 mM titanium isopropoxide and 6 M hydrochloric acid at 170 °C for 105 min. The compact PbS quantum-dot thin film on the TiO_2 nanorod array is firstly obtained by the spin-coating-assisted successive ionic layer absorption and reaction with using 1,2-ethanedithiol (EDT). The result reveals that the strong interaction between lead and EDT is very important to control the crystallite size of PbS quantum-dots and obtain the compact PbS quantum-dot thin film on the TiO_2 nanorod array. The all solid-state sensitized solar cell with the combination of the short-length, high-density TiO_2 nanorod array and the compact PbS quantum-dot thin film achieves the photoelectric conversion efficiency of 4.10%, along with an open

  20. Combination of short-length TiO{sub 2} nanorod arrays and compact PbS quantum-dot thin films for efficient solid-state quantum-dot-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhengguo [School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009 (China); School of Chemistry and Chemical Engineering, Beifang University of Nationalities, Yinchuan 750021 (China); Shi, Chengwu, E-mail: shicw506@foxmail.com [School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009 (China); Chen, Junjun; Xiao, Guannan; Li, Long [School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009 (China)

    2017-07-15

    Graphical abstract: The TiO{sub 2} nanorod array with the length of 600 nm, the diameter of 20 nm, the areal density of 500 μm{sup −2} was successfully prepared. The compact PbS quantum-dot thin film was firstly obtained on the TiO{sub 2} nanorod array by spin-coating-assisted successive ionic layer absorption and reaction with using 1,2-ethanedithiol. The photoelectric conversion efficiency (PCE) of the compact PbS quantum-dot thin film sensitized solar cells achieved 4.10% using spiro-OMeTAD as a hole transporting layer, while the PCE of the PbS quantum-dot sensitized solar cells was only 0.54%. - Highlights: • Preparation of TiO{sub 2} nanorod arrays with the length of 600 nm, diameter of 20 nm. • The compact PbS QD thin film and short-length TiO{sub 2} nanorod array were combined. • EDT addition improved PbS nanoparticle coverage and photovoltaic performance. • The compact PbS QD thin film sensitized solar cell achieved the PCE of 4.10%. - Abstract: Considering the balance of the hole diffusion length and the loading quantity of quantum-dots, the rutile TiO{sub 2} nanorod array with the length of 600 nm, the diameter of 20 nm, and the areal density of 500 μm{sup −2} is successfully prepared by the hydrothermal method using the aqueous grown solution of 38 mM titanium isopropoxide and 6 M hydrochloric acid at 170 °C for 105 min. The compact PbS quantum-dot thin film on the TiO{sub 2} nanorod array is firstly obtained by the spin-coating-assisted successive ionic layer absorption and reaction with using 1,2-ethanedithiol (EDT). The result reveals that the strong interaction between lead and EDT is very important to control the crystallite size of PbS quantum-dots and obtain the compact PbS quantum-dot thin film on the TiO{sub 2} nanorod array. The all solid-state sensitized solar cell with the combination of the short-length, high-density TiO{sub 2} nanorod array and the compact PbS quantum-dot thin film achieves the photoelectric conversion

  1. Glass bottle sampling solid phase microextraction gas chromatography mass spectrometry for breath analysis of drug metabolites.

    Science.gov (United States)

    Lu, Yan; Niu, Wenqi; Zou, Xue; Shen, Chengyin; Xia, Lei; Huang, Chaoqun; Wang, Hongzhi; Jiang, Haihe; Chu, Yannan

    2017-05-05

    Breath analysis is a non-invasive approach which may be applied to disease diagnosis and pharmacokinetic study. In the case of offline analysis, the exhaled gas needs to be collected and the sampling bag is often used as the storage vessel. However, the sampling bag usually releases some extra compounds, which may interfere with the result of the breath test. In this study, a novel breath sampling glass bottle was developed with a syringe needle sampling port for solid phase microextraction (SPME). Such a glass bottle scarcely liberates compounds and can be used to collect exhaled gas for ensuing analysis by gas chromatography-mass spectrometry (GC-MS). The glass bottle sampling SPME-GC-MS analysis was carried out to investigate the breath metabolites of myrtol, a multicompound drug normally used in the treatment of bronchitis and sinusitis. Four compounds, α-pinene, 2,3-dehydro-1,8-cineole, d-limonene and 1,8-cineole were found in the exhaled breath of all eight volunteers who had taken the myrtol. While for other ten subjects who had not used the myrtol, these compounds were undetectable. In the SPME-GC-MS analysis of the headspace of myrtol, three compounds were detected including α-pinene, d-limonene and 1,8-cineole. Comparing the results of breath and headspace analysis, it indicates that 2,3-dehydro-1,8-cineole in the breath is the metabolite of 1,8-cineole. It is the first time that this metabolite was identified in human breath. The study demonstrates that the glass bottle sampling SPME-GC-MS method is applicable to exhaled gas analysis including breath metabolites investigation of drugs like myrtol. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Heat and mass transfer analysis intermediate temperature solid oxide fuel cells (IT-SOFC)

    International Nuclear Information System (INIS)

    Timurkutluk, B.; Mat, M. M.; Kaplan, Y.

    2007-01-01

    Solid oxide fuel cells (SOFCs) have been considered as next generation energy conversion system due to their high efficiency, clean and quite operation with fuel flexibility. To date, yittria stabilized zirconia (YSZ) electrolytes have been mainly used for SOFC applications at high temperatures around 1000 degree C because of their high ionic conductivity, chemical stability and good mechanical properties. However, such a high temperature is undesirable for fuel cell operations in the viewpoint of stability. Moreover, high operation temperature necessitates high cost interconnect and seal materials. Thus, the reduction in the operation temperature of SOFCs is one of the key issues in the aspects of the cost reduction and the long term operation without degradation as well as commercialization of the SOFC systems. With the reducing temperature, not only low cost stainless steels and glass materials can be used as interconnect and sealing materials respectively but the manufacturing technology will also extend. Therefore, the design of complex geometrical SOFC component will also be possible. One way to reduce the operation temperature of SOFC is use of an alternative electrolyte material to YSZ showing acceptable properties at intermediate temperatures (600-800 degree C). As being one of IT-SOFC electrolyte materials, gadolinium doped ceria (GDC) has been taken great deals. In this study, a mathematical model for mass and heat transfer for a single cell GDC electrolyte SOFC system was developed and numerical solutions were evaluated. In order to verify the mathematical model, set of experiments were performed by taking species from four different samples randomly and five various temperature measurements. The numerical results reasonably agree with experimental data

  3. First Solid Evidence for a Rocky Exoplanet - Mass and density of smallest exoplanet finally measured

    Science.gov (United States)

    2009-09-01

    The longest set of HARPS measurements ever made has firmly established the nature of the smallest and fastest-orbiting exoplanet known, CoRoT-7b, revealing its mass as five times that of Earth's. Combined with CoRoT-7b's known radius, which is less than twice that of our terrestrial home, this tells us that the exoplanet's density is quite similar to the Earth's, suggesting a solid, rocky world. The extensive dataset also reveals the presence of another so-called super-Earth in this alien solar system. "This is science at its thrilling and amazing best," says Didier Queloz, leader of the team that made the observations. "We did everything we could to learn what the object discovered by the CoRoT satellite looks like and we found a unique system." In February 2009, the discovery by the CoRoT satellite [1] of a small exoplanet around a rather unremarkable star named TYC 4799-1733-1 was announced one year after its detection and after several months of painstaking measurements with many telescopes on the ground, including several from ESO. The star, now known as CoRoT-7, is located towards the constellation of Monoceros (the Unicorn) at a distance of about 500 light-years. Slightly smaller and cooler than our Sun, CoRoT-7 is also thought to be younger, with an age of about 1.5 billion years. Every 20.4 hours, the planet eclipses a small fraction of the light of the star for a little over one hour by one part in 3000 [2]. This planet, designated CoRoT-7b, is only 2.5 million kilometres away from its host star, or 23 times closer than Mercury is to the Sun. It has a radius that is about 80% greater than the Earth's. The initial set of measurements, however, could not provide the mass of the exoplanet. Such a result requires extremely precise measurements of the velocity of the star, which is pulled a tiny amount by the gravitational tug of the orbiting exoplanet. The problem with CoRoT-7b is that these tiny signals are blurred by stellar activity in the form of

  4. Solid-supported enzymatic synthesis of pectic oligogalacturonides and their analysis by MALDI-TOF mass spectrometry

    DEFF Research Database (Denmark)

    Guillaumie, Fanny; Sterling, J.D.; Jensen, K.J.

    2003-01-01

    Solid-phase biosynthetic reactions, followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis (MALDI-TOF), was used to gain insight into the biosynthesis of pectin oligomers. Sepharose supports bearing long pectic oligogalacturonides (OGAs) anchored through...... into the liquid phases by MALDI-TOF mass spectrometry. In time course studies conducted with an immobilized (alpha-D-GalA)(14) and limiting amounts of the glycosyl donor, the predominant product was an OGA extended by one GalA residue at the non-reducing end (i.e., (GalA)(15)). When UDP-GalA was added...

  5. Automatisation of reading and interpreting photographically recorded spark source mass spectra for the quantitative analysis in solids

    International Nuclear Information System (INIS)

    Naudin, Guy.

    1976-01-01

    Quantitative analysis in solids by spark source mass spectrometry involves the study of photographic plates by means of a microdensitometer. After a graphic treatment of data from the plate, a scientific program is used to calculate the concentrations of isotopes. The automatisation of the three parts has been realised by using a program for computer. This program has been written in the laboratory for a small computer (Multi 8, Intertechnique) [fr

  6. A new approach to determine the density of liquids and solids without measuring mass and volume: introducing the solidensimeter

    Science.gov (United States)

    Kiriktaş, Halit; Şahin, Mehmet; Eslek, Sinan; Kiriktaş, İrem

    2018-05-01

    This study aims to design a mechanism with which the density of any solid or liquid can be determined without measuring its mass and volume in order to help students comprehend the concept of density more easily. The solidensimeter comprises of two scaled and nested glass containers (graduated cylinder or beaker) and sufficient water. In this method, the density measurement was made using the Archimedes’ principle stating that an object fully submerged in a liquid displaces the same amount of liquid as its volume, while an object partially submerged or floating displaces the same amount of liquid as its mass. Using this method, the density of any solids or liquids can be determined using a simple mathematical ratio. At the end of the process a mechanism that helps students to comprehend the density topic more easily was designed. The system is easy-to-design, uses low-cost equipment and enables one to determine the density of any solid or liquid without measuring its mass and volume.

  7. Diagnostic performance of quantitative shear wave elastography in the evaluation of solid breast masses: determination of the most discriminatory parameter.

    Science.gov (United States)

    Au, Frederick Wing-Fai; Ghai, Sandeep; Moshonov, Hadas; Kahn, Harriette; Brennan, Cressida; Dua, Hemi; Crystal, Pavel

    2014-09-01

    The purpose of this article is to assess the diagnostic performance of quantitative shear wave elastography in the evaluation of solid breast masses and to determine the most discriminatory parameter. B-mode ultrasound and shear wave elastography were performed before core biopsy of 123 masses in 112 women. The diagnostic performance of ultrasound and quantitative shear wave elastography parameters (mean elasticity, maximum elasticity, and elasticity ratio) were compared. The added effect of shear wave elastography on the performance of ultrasound was determined. The mean elasticity, maximum elasticity, and elasticity ratio were 24.8 kPa, 30.3 kPa, and 1.90, respectively, for 79 benign masses and 130.7 kPa, 154.9 kPa, and 11.52, respectively, for 44 malignant masses (p shear wave elastography parameter was higher than that of ultrasound (p shear wave elastography parameters to the evaluation of BI-RADS category 4a masses, about 90% of masses could be downgraded to BI-RADS category 3. The numbers of downgraded masses were 40 of 44 (91%) for mean elasticity, 39 of 44 (89%) for maximum elasticity, and 42 of 44 (95%) for elasticity ratio. The numbers of correctly downgraded masses were 39 of 40 (98%) for mean elasticity, 38 of 39 (97%) for maximum elasticity, and 41 of 42 (98%) for elasticity ratio. There was improvement in the diagnostic performance of ultrasound of mass assessment with shear wave elastography parameters added to BI-RADS category 4a masses compared with ultrasound alone. Combined ultrasound and elasticity ratio had the highest improvement, from 35.44% to 87.34% for specificity, from 45.74% to 80.77% for positive predictive value, and from 57.72% to 90.24% for accuracy (p shear wave elastography parameters of benign and malignant solid breast masses. By adding shear wave elastography parameters to BI-RADS category 4a masses, we found that about 90% of them could be correctly downgraded to BI-RADS category 3, thereby avoiding biopsy. Elasticity ratio

  8. ALMA Compact Array observations of the Fried Egg nebula: Evidence for large-scale asymmetric mass-loss from the yellow hypergiant IRAS 17163-3907.

    Science.gov (United States)

    Wallström, S H J; Lagadec, E; Muller, S; Black, J H; Cox, N L J; Galván-Madrid, R; Justtanont, K; Longmore, S; Olofsson, H; Oudmaijer, R D; Quintana-Lacaci, G; Szczerba, R; Vlemmings, W; van Winckel, H; Zijlstra, A

    2017-01-10

    Yellow hypergiants are rare and represent a fast evolutionary stage of massive evolved stars. That evolutionary phase is characterised by a very intense mass loss, the understanding of which is still very limited. Here we report ALMA Compact Array observations of a 50″-mosaic toward the Fried Egg nebula, around one of the few Galactic yellow hypergiants IRAS 17163-3907. The emission from the 12 CO J=2-1 line, H30 α recombination line, and continuum is imaged at a resolution of ~8″, revealing the morphology of the molecular environment around the star. The continuum emission is unresolved and peaks at the position of the star. The radio recombination line H30 α shows unresolved emission at the star, with an approximately gaussian spectrum centered on a velocity of 21±3 km s -1 with a width of 57±6 km s -1 . In contrast, the CO 2-1 emission is complex and decomposes into several components beyond the contamination from interstellar gas in the line of sight. The CO spectrum toward the star is a broad plateau, centered at the systemic velocity of +18 km s -1 and with an expansion velocity of 100±10 km s -1 . Assuming isotropic and constant mass-loss, we estimate a mass-loss rate of 8±1.5 ×10 -5 M ⊙ yr -1 . At a radius of 25″ from the star, we detect CO emission associated with the dust ring previously imaged by Herschel . The kinematics of this ring, however, is not consistent with an expanding shell, but show a velocity gradient of v sys ±20 km s -1 . In addition, we find a puzzling bright feature radially connecting the star to the CO ring, at a velocity of +40 km s -1 relative to the star. This spur feature may trace a unidirectional ejection event from the star. Our ACA observations reveal the complex morphology around IRAS 17163 and illustrate the breakthroughs that ALMA will bring to the field of massive stellar evolution.

  9. Stopping-power and mass energy-absorption coefficient ratios for Solid Water

    International Nuclear Information System (INIS)

    Ho, A.K.; Paliwal, B.R.

    1986-01-01

    The AAPM Task Group 21 protocol provides tables of ratios of average restricted stopping powers and ratios of mean energy-absorption coefficients for different materials. These values were based on the work of Cunningham and Schulz. We have calculated these quantities for Solid Water (manufactured by RMI), using the same x-ray spectra and method as that used by Cunningham and Schulz. These values should be useful to people who are using Solid Water for high-energy photon calibration

  10. XCAMS: The compact "1"4C accelerator mass spectrometer extended for "1"0Be and "2"6Al at GNS Science, New Zealand

    International Nuclear Information System (INIS)

    Zondervan, A.; Hauser, T.M.; Kaiser, J.; Kitchen, R.L.; Turnbull, J.C.; West, J.G.

    2015-01-01

    Highlights: • We review the performance of a 0.5 MV AMS system for "1"0Be, "1"4C, and "2"6Al. • We identify the limiting factors to "1"0Be machine blank and detection efficiency. • We discuss an AMS data reduction method that accounts for non-Poisson uncertainty. - Abstract: A detailed description is given of the 0.5 MV tandem accelerator mass spectrometry (AMS) system for "1"0Be, "1"4C, "2"6Al, installed in early 2010 at GNS Science, New Zealand. Its design follows that of previously commissioned Compact "1"4C-only AMS (CAMS) systems based on the Pelletron tandem accelerator. The only basic departure from that design is an extension of the rare-isotope achromat with a 45° magnet and a two-anode gas-ionisation detector, to provide additional filtering for "1"0Be. Realised performance of the three AMS modes is discussed in terms of acceptance-test scores, "1"4C Poisson and non-Poisson errors, and "1"0Be detection limit and sensitivity. Operational details and hardware improvements, such as "1"0Be beam transport and particle detector setup, are highlighted. Statistics of repeat measurements of all graphitised "1"4C calibration cathodes since start-up show that 91% of their total uncertainty values are less than 0.3%, indicating that the rare-isotope beamline extension has not affected precision of "1"4C measurement. For "1"0Be, the limit of detection in terms of the isotopic abundance ratio "1"0Be/"9Be is 6 × 10"−"1"5 at at"−"1 and the total efficiency of counting atoms in the sample cathode is 1/8500 (0.012%).

  11. XCAMS: The compact {sup 14}C accelerator mass spectrometer extended for {sup 10}Be and {sup 26}Al at GNS Science, New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Zondervan, A., E-mail: a.zondervan@gns.cri.nz [GNS Science, Lower Hutt (New Zealand); Hauser, T.M. [National Electrostatics Corporation, Middleton, WI (United States); Kaiser, J. [GNS Science, Lower Hutt (New Zealand); Kitchen, R.L. [National Electrostatics Corporation, Middleton, WI (United States); Turnbull, J.C.; West, J.G. [GNS Science, Lower Hutt (New Zealand)

    2015-10-15

    Highlights: • We review the performance of a 0.5 MV AMS system for {sup 10}Be, {sup 14}C, and {sup 26}Al. • We identify the limiting factors to {sup 10}Be machine blank and detection efficiency. • We discuss an AMS data reduction method that accounts for non-Poisson uncertainty. - Abstract: A detailed description is given of the 0.5 MV tandem accelerator mass spectrometry (AMS) system for {sup 10}Be, {sup 14}C, {sup 26}Al, installed in early 2010 at GNS Science, New Zealand. Its design follows that of previously commissioned Compact {sup 14}C-only AMS (CAMS) systems based on the Pelletron tandem accelerator. The only basic departure from that design is an extension of the rare-isotope achromat with a 45° magnet and a two-anode gas-ionisation detector, to provide additional filtering for {sup 10}Be. Realised performance of the three AMS modes is discussed in terms of acceptance-test scores, {sup 14}C Poisson and non-Poisson errors, and {sup 10}Be detection limit and sensitivity. Operational details and hardware improvements, such as {sup 10}Be beam transport and particle detector setup, are highlighted. Statistics of repeat measurements of all graphitised {sup 14}C calibration cathodes since start-up show that 91% of their total uncertainty values are less than 0.3%, indicating that the rare-isotope beamline extension has not affected precision of {sup 14}C measurement. For {sup 10}Be, the limit of detection in terms of the isotopic abundance ratio {sup 10}Be/{sup 9}Be is 6 × 10{sup −15} at at{sup −1} and the total efficiency of counting atoms in the sample cathode is 1/8500 (0.012%).

  12. Compact NMR

    Energy Technology Data Exchange (ETDEWEB)

    Bluemich, Bernhard; Haber-Pohlmeier, Sabina; Zia, Wasif [RWTH Aachen Univ. (Germany). Inst. fuer Technische und Makromolekulare Chemie (ITMC)

    2014-06-01

    Nuclear Magnetic Resonance (NMR) spectroscopy is the most popular method for chemists to analyze molecular structures, while Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic tool for medical doctors that provides high-contrast images of biological tissue. In both applications, the sample (or patient) is positioned inside a large, superconducting magnet to magnetize the atomic nuclei. Interrogating radio-frequency pulses result in frequency spectra that provide the chemist with molecular information, the medical doctor with anatomic images, and materials scientist with NMR relaxation parameters. Recent advances in magnet technology have led to a variety of small permanent magnets to allow compact and low-cost instruments. The goal of this book is to provide an introduction to the practical use of compact NMR at a level nearly as basic as the operation of a smart phone.

  13. Compact vortices

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D.; Losano, L.; Marques, M.A.; Zafalan, I. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, PB (Brazil); Menezes, R. [Universidade Federal da Paraiba, Departamento de Ciencias Exatas, Rio Tinto, PB (Brazil); Universidade Federal de Campina Grande, Departamento de Fisica, Campina Grande, PB (Brazil)

    2017-02-15

    We study a family of Maxwell-Higgs models, described by the inclusion of a function of the scalar field that represent generalized magnetic permeability. We search for vortex configurations which obey first-order differential equations that solve the equations of motion. We first deal with the asymptotic behavior of the field configurations, and then implement a numerical study of the solutions, the energy density and the magnetic field. We work with the generalized permeability having distinct profiles, giving rise to new models, and we investigate how the vortices behave, compared with the solutions of the corresponding standard models. In particular, we show how to build compact vortices, that is, vortex solutions with the energy density and magnetic field vanishing outside a compact region of the plane. (orig.)

  14. Solid phase extraction-electrospray ionization mass spectrometric method for the determination of palladium

    International Nuclear Information System (INIS)

    Pranaw Kumar; Telmore, Vijay M.; Jaison, P.G.; Sarkar, Arnab; Alamelu, D.; Aggarwal, S.K.

    2015-01-01

    Platinum group of element (PGEs) are extensively used as a catalyst and anticancer reagent. Due to the soft nature of PGEs, sulphur based donar ligands are used for the separation of these elements. Studies on the formation of different species are helpful for obtaining the ideas about separation of these elements from the complex matrices. Palladium (Pd) is studied as a representative element which is also formed by nuclear fission of fissile nuclides. In view of the relatively small amount of solvent required for separation, solid phase extraction is preferred over most of the separation methods. Solid phase extraction method using DPX as a stationary phase was previously reported for the separation of Pd in SHLLW using benzoylthiourea as a ligand. However, in case of large volume samples manual extraction by DPX is tedious task. In the present studies, the feasibility of extraction using benzoylthiourea on automated solid phase extraction system was carried out for the extraction of Pd

  15. Symposium on fast atom and ion induced mass spectrometry of nonvolatile organic solids

    International Nuclear Information System (INIS)

    McNeal, C.J.

    1982-01-01

    The mechanisms of molecular and fragment ion production and the various parameters affecting ion yields were discussed by 6 invited speakers from Europe, Canada, and the US at this symposium. The work reported was almost equally divided between that using low-energy (keV) primary ion (or atom) beams, e.g. fast atom bombardment mass spectrometry (FABMS) and secondary ion mass spectrometry (SIMS) and that using high energy (MeV) particles, e.g. heavy ion induced mass spectrometry (HIIDMS) and 252 Cf-plasma desorption mass spectrometry ( 252 Cf-PDMS). Both theoretical foundations and observed experimental results for both techniques are included

  16. Feasibility analysis of municipal solid waste mass burning in the Region of East Macedonia--Thrace in Greece.

    Science.gov (United States)

    Athanasiou, C J; Tsalkidis, D A; Kalogirou, E; Voudrias, E A

    2015-06-01

    The present work conducts a preliminary techno-economic feasibility study for a single municipal solid waste mass burning to an electricity plant for the total municipal solid waste potential of the Region of Eastern Macedonia - Thrace, in Greece. For a certain applied and highly efficient technology and an installed capacity of 400,000 t of municipal solid waste per year, the available electrical power to grid would be approximately 260 GWh per year (overall plant efficiency 20.5% of the lower heating value). The investment for such a plant was estimated at €200m. Taking into account that 37.9% of the municipal solid waste lower heating value can be attributed to their renewable fractions, and Greek Law 3851/2010, which transposes Directive 2009/28/EC for Renewable Energy Sources, the price of the generated electricity was calculated at €53.19/MWhe. Under these conditions, the economic feasibility of such an investment depends crucially on the imposed gate fees. Thus, in the gate fee range of 50-110 € t(-1), the internal rate of return increases from 5% to above 15%, whereas the corresponding pay-out time periods decrease from 11 to about 4 years. © The Author(s) 2015.

  17. Mycoestrogen determination in cow milk: Magnetic solid-phase extraction followed by liquid chromatography and tandem mass spectrometry analysis.

    Science.gov (United States)

    Capriotti, Anna Laura; Cavaliere, Chiara; Foglia, Patrizia; La Barbera, Giorgia; Samperi, Roberto; Ventura, Salvatore; Laganà, Aldo

    2016-12-01

    Recently, magnetic solid-phase extraction has gained interest because it presents various operational advantages over classical solid-phase extraction. Furthermore, magnetic nanoparticles are easy to prepare, and various materials can be used in their synthesis. In the literature, there are only few studies on the determination of mycoestrogens in milk, although their carryover in milk has occurred. In this work, we wanted to develop the first (to the best of our knowledge) magnetic solid-phase extraction protocol for six mycoestrogens from milk, followed by liquid chromatography and tandem mass spectrometry analysis. Magnetic graphitized carbon black was chosen as the adsorbent, as this carbonaceous material, which is very different from the most diffuse graphene and carbon nanotubes, had already shown selectivity towards estrogenic compounds in milk. The graphitized carbon black was decorated with Fe 3 O 4 , which was confirmed by the characterization analyses. A milk deproteinization step was avoided, using only a suitable dilution in phosphate buffer as sample pretreatment. The overall process efficiency ranged between 52 and 102%, whereas the matrix effect considered as signal suppression was below 33% for all the analytes even at the lowest spiking level. The obtained method limits of quantification were below those of other published methods that employ classical solid-phase extraction protocols. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Influence of secondary settling tank performance on suspended solids mass balance in activated sludge systems.

    Science.gov (United States)

    Patziger, M; Kainz, H; Hunze, M; Józsa, J

    2012-05-01

    Secondary settling is the final step of the activated sludge-based biological waste water treatment. Secondary settling tanks (SSTs) are therefore an essential unit of producing a clear effluent. A further important function of SSTs is the sufficient thickening to achieve highly concentrated return sludge and biomass within the biological reactor. In addition, the storage of activated sludge is also needed in case of peak flow events (Ekama et al., 1997). Due to the importance of a high SST performance the problem has long been investigated (Larsen, 1977; Krebs, 1991; Takács et al., 1991; Ekama et al., 1997; Freimann, 1999; Patziger et al., 2005; Bürger et al., 2011), however, a lot of questions are still to solve regarding e.g. the geometrical features (inflow, outflow) and operations (return sludge control, scraper mechanism, allowable maximum values of surface overflow rates). In our study we focused on SSTs under dynamic load considering both the overall unsteady behaviour and the features around the peaks, investigating the effect of various sludge return strategies as well as the inlet geometry on SST performance. The main research tool was a FLUENT-based novel mass transport model consisting of two modules, a 2D axisymmetric SST model and a mixed reactor model of the biological reactor (BR). The model was calibrated and verified against detailed measurements of flow and concentration patterns, sludge settling, accompanied with continuous on-line measurement of in- and outflow as well as returned flow rates of total suspended solids (TSS) and water. As to the inlet arrangement a reasonable modification of the geometry could result in the suppression of the large scale flow structures of the sludge-water interface thus providing a significant improvement in the SST performance. Furthermore, a critical value of the overflow rate (q(crit)) was found at which a pronounced large scale circulation pattern develops in the vertical plane, the density current in

  19. Predicting protein aggregation during storage in lyophilized solids using solid state amide hydrogen/deuterium exchange with mass spectrometric analysis (ssHDX-MS).

    Science.gov (United States)

    Moorthy, Balakrishnan S; Schultz, Steven G; Kim, Sherry G; Topp, Elizabeth M

    2014-06-02

    Solid state amide hydrogen/deuterium exchange with mass spectrometric analysis (ssHDX-MS) was used to assess the conformation of myoglobin (Mb) in lyophilized formulations, and the results correlated with the extent of aggregation during storage. Mb was colyophilized with sucrose (1:1 or 1:8 w/w), mannitol (1:1 w/w), or NaCl (1:1 w/w) or in the absence of excipients. Immediately after lyophilization, samples of each formulation were analyzed by ssHDX-MS and Fourier transform infrared spectroscopy (FTIR) to assess Mb conformation, and by dynamic light scattering (DLS) and size exclusion chromatography (SEC) to determine the extent of aggregation. The remaining samples were then placed on stability at 25 °C and 60% RH or 40 °C and 75% RH for up to 1 year, withdrawn at intervals, and analyzed for aggregate content by SEC and DLS. In ssHDX-MS of samples immediately after lyophilization (t = 0), Mb was less deuterated in solids containing sucrose (1:1 and 1:8 w/w) than in those containing mannitol (1:1 w/w), NaCl (1:1 w/w), or Mb alone. Deuterium uptake kinetics and peptide mass envelopes also indicated greater Mb structural perturbation in mannitol, NaCl, or Mb-alone samples at t = 0. The extent of deuterium incorporation and kinetic parameters related to rapidly and slowly exchanging amide pools (Nfast, Nslow), measured at t = 0, were highly correlated with the extent of aggregation on storage as measured by SEC. In contrast, the extent of aggregation was weakly correlated with FTIR band intensity and peak position measured at t = 0. The results support the use of ssHDX-MS as a formulation screening tool in developing lyophilized protein drug products.

  20. Binder-free activated graphene compact films for all-solid-state micro-supercapacitors with high areal and volumetric capacitances

    DEFF Research Database (Denmark)

    Wu, Zhong Shuai; Yang, Sheng; Zhang, Lili

    2015-01-01

    Micro-supercapacitors (MSCs) hold great promise as highly competitive miniaturized power sources satisfying the increased demand in microelectronics; however, simultaneously achieving high areal and volumetric capacitances is still a great challenge. Here we demonstrated the designed construction...... of binder-free, electrically conductive, nanoporous activated graphene (AG) compact films for high-performance MSCs. The binder-free AG films are fabricated by alternating deposition of electrochemically exfoliated graphene (EG) and nanoporous AG with a high specific surface area of 2920 m2/g, and then dry...

  1. Development of a portable mass spectrometric system for determination of isotopic composition of solid uranium samples using fluorine volatilization

    Science.gov (United States)

    Loge, G.

    1994-09-01

    Using hardware and materials supplied by LANL, a prototype quadrupole mass spectrometer system designed for portable field analysis of isotopic composition of solid uranium samples was assembled and tested. The system contained the capability for fluorine volatilization of solid uranium samples with gas introduction, which was successfully tested and demonstrated using 100 mg samples of U3O8. Determination of precision and accuracy for measuring isotopic composition was performed using isotopic standards. Use with soil samples containing uranium were also attempted. Silicates in the soil forming SiF4 were found to be a kinetic bottleneck to the formation of UF6. This could be avoided by performing some sort of chemical separation as a pre-treatment step, which was demonstrated using nitric acid.

  2. Detailed simulations of liquid and solid-liquid mixing : Turbulent agitated flow and mass transfer

    NARCIS (Netherlands)

    Hartmann, H.

    2005-01-01

    This thesis aims at a contribution to reliable and accurate predictions of complex, multi-phase processes. The reader is presented detailed simulations on liquid and solid-liquid mixing using large eddy simulations (LES) including scalar mixing and particle transport in a Rushton turbine stirred

  3. Compact electron storage rings

    International Nuclear Information System (INIS)

    Williams, G.P.

    1987-01-01

    There have been many recent developments in the area of compact storage rings. Such rings would have critical wavelengths of typically 10 A, achieved with beam energies of several hundreds of MeV and superconducting dipole fields of around 5 Tesla. Although the primary motivation for progress in this area is that of commercial x-ray lithography, such sources might be an attractive source for college campuses to operate. They would be useful for many programs in materials science, solid state, x-ray microscopy and other biological areas. We discuss the properties of such sources and review developments around the world, primarily in the USA, japan and W. Germany

  4. Diverse Formation Mechanisms for Compact Galaxies

    Science.gov (United States)

    Kim, Jin-Ah; Paudel, Sanjaya; Yoon, Suk-Jin

    2018-01-01

    Compact, quenched galaxies such as M32 are unusual ones located off the mass - size scaling relation defined by normal galaxies. Still, their formation mechanisms remain unsolved. Here we investigate the evolution of ~100 compact, quenched galaxies at z = 0 identified in the Illustris cosmological simulation. We identify three ways for a galaxy to become a compact one and, often, multiple mechanisms operate in a combined manner. First, stripping is responsible for making about a third of compact galaxies. Stripping removes stars from galaxies, usually while keeping their sizes intact. About one third are galaxies that cease their growth early on after entering into more massive, gigantic halos. Finally, about half of compact galaxies, ~ 35 % of which turn out to undergo stripping, experience the compaction due to the highly centrally concentrated star formation. We discuss the evolutionary path of compact galaxies on the mass – size plane for each mechanism in a broader context of dwarf galaxy formation and evolution.

  5. Moisture and drug solid-state monitoring during a continuous drying process using empirical and mass balance models

    DEFF Research Database (Denmark)

    Fonteyne, Margot; Gildemyn, Delphine; Peeters, Elisabeth

    2014-01-01

    of Process Analytical Technology (PAT) tools (Raman and NIR spectroscopy) and a mass balance approach. The six-segmented fluid bed drying system being part of a fully continuous from-powder-to-tablet production line (ConsiGma™-25) was used for this study. A theophylline:lactose:PVP (30:67.5:2.5) blend......, the different size fractions of the dried granules obtained during different experiments (fines, yield and oversized granules) were compared separately, revealing differences in both solid state of theophylline and moisture content between the different granule size fractions. © 2014 Elsevier B.V. All rights...... reserved...

  6. Compact heat and mass exchangers of the plate fin type in thermal sorption systems: Application in an absorption heat pump with the working pair CH3OH-LiBr/ZnBr2

    Science.gov (United States)

    Becker, Harry

    The possible application of Compact Heat and Mass Exchangers (CHME) in a gas fired Absorption Heat Pump (AHP) for domestic heating is studied. The above mentioned heat and mass exchangers are of the plate type. The space between the parallel and plain plates is filled up with corrugated plates of a certain height. The plain and finned plates are stacked and welded together. This gives a heat and mass exchanger which is very compact, expressed by a high area density (m2/m3). This leads to heat and mass transfer processes with small temperature and concentration differences. For testing purposes a pilot plant was built using the above type of components in order to test their heat and/or mass transfer performance. Only the generator is of the Shell And Tube (SAT) type. As the working pair, CH3OH - LiBr/ ZnBr2 was chosen, with the alcohol as the solvent and the salt mixture as the absorbent. This leads to sub atmospheric working pressures with only solvent in the vapor phase. Three series of experiments have been carried out, during which the input parameters were varied over a certain range. It is concluded that the plate fin CHMES are very suitable for application in an AHP for domestic heating purposes.

  7. The leaf volatile constituents of Isatis tinctoria by Solid-Phase Microextraction and Gas chromatography/Mass Spectrometry.

    Science.gov (United States)

    Condurso, Cettina; Verzera, Antonella; Romeo, Vincenza; Ziino, Marisa; Trozzi, Alessandra; Ragusa, Salvatore

    2006-08-01

    The leaf volatile constituents of Isatis tinctoria L. (Brassicaceae) have been studied by Solid-Phase Microextraction and Gas chromatography/Mass Spectrometry (SPME/GC-MS). Seventy components were fully characterized by mass spectra, linear retention indices, and injection of standards; the average composition (ppm) as single components and classes of substances is reported. Aliphatic hydrocarbons, acids, alcohols, aldehydes and esters, aromatic aldehydes, esters and ethers, furans, isothiocyanates and thiocyanates, sulfurated compounds, nitriles, terpenes and sesquiterpenes were identified. Leaf volatiles in Isatis tinctoria L. were characterized by a high amount of isothiocyanates which accounted for about 40 % of the total volatile fraction. Isothiocyanates are important and characteristic flavour compounds in Brassica vegetables and the cancer chemo-protective attributes are recently responsible for their growing interest.

  8. Solid-Phase Extraction Strategies to Surmount Body Fluid Sample Complexity in High-Throughput Mass Spectrometry-Based Proteomics

    Science.gov (United States)

    Bladergroen, Marco R.; van der Burgt, Yuri E. M.

    2015-01-01

    For large-scale and standardized applications in mass spectrometry- (MS-) based proteomics automation of each step is essential. Here we present high-throughput sample preparation solutions for balancing the speed of current MS-acquisitions and the time needed for analytical workup of body fluids. The discussed workflows reduce body fluid sample complexity and apply for both bottom-up proteomics experiments and top-down protein characterization approaches. Various sample preparation methods that involve solid-phase extraction (SPE) including affinity enrichment strategies have been automated. Obtained peptide and protein fractions can be mass analyzed by direct infusion into an electrospray ionization (ESI) source or by means of matrix-assisted laser desorption ionization (MALDI) without further need of time-consuming liquid chromatography (LC) separations. PMID:25692071

  9. On-line double isotope dilution laser ablation inductively coupled plasma mass spectrometry for the quantitative analysis of solid materials.

    Science.gov (United States)

    Fernández, Beatriz; Rodríguez-González, Pablo; García Alonso, J Ignacio; Malherbe, Julien; García-Fonseca, Sergio; Pereiro, Rosario; Sanz-Medel, Alfredo

    2014-12-03

    We report on the determination of trace elements in solid samples by the combination of on-line double isotope dilution and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The proposed method requires the sequential analysis of the sample and a certified natural abundance standard by on-line IDMS using the same isotopically-enriched spike solution. In this way, the mass fraction of the analyte in the sample can be directly referred to the certified standard so the previous characterization of the spike solution is not required. To validate the procedure, Sr, Rb and Pb were determined in certified reference materials with different matrices, including silicate glasses (SRM 610, 612 and 614) and powdered samples (PACS-2, SRM 2710a, SRM 1944, SRM 2702 and SRM 2780). The analysis of powdered samples was carried out both by the preparation of pressed pellets and by lithium borate fusion. Experimental results for the analysis of powdered samples were in agreement with the certified values for all materials. Relative standard deviations in the range of 6-21% for pressed pellets and 3-21% for fused solids were obtained from n=3 independent measurements. Minimal sample preparation, data treatment and consumption of the isotopically-enriched isotopes are the main advantages of the method over previously reported approaches. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Performance of Shear Wave Elastography for Differentiation of Benign and Malignant Solid Breast Masses

    Science.gov (United States)

    Song, Yi-Jiang; Deng, Zhu-Jun; Gao, Jian; Xie, Yan; Yin, Tian-Sheng; Ying, Li; Tang, Kai-Fu

    2013-01-01

    Objectives To perform a meta-analysis assessing the ability of shear wave elastography (SWE) to identify malignant breast masses. Methods PubMed, the Cochrane Library, and the ISI Web of Knowledge were searched for studies evaluating the accuracy of SWE for identifying malignant breast masses. The diagnostic accuracy of SWE was evaluated according to sensitivity, specificity, and hierarchical summary receiver operating characteristic (HSROC) curves. An analysis was also performed according to the SWE mode used: supersonic shear imaging (SSI) and the acoustic radiation force impulse (ARFI) technique. The clinical utility of SWE for identifying malignant breast masses was evaluated using analysis of Fagan plot. Results A total of 9 studies, including 1888 women and 2000 breast masses, were analyzed. Summary sensitivities and specificities were 0.91 (95% confidence interval [CI], 0.88–0.94) and 0.82 (95% CI, 0.75–0.87) by SSI and 0.89 (95% CI, 0.81–0.94) and 0.91 (95% CI, 0.84–0.95) by ARFI, respectively. The HSROCs for SSI and ARFI were 0.92 (95% CI, 0.90–0.94) and 0.96 (95% CI, 0.93–0.97), respectively. SSI and ARFI were both very informative, with probabilities of 83% and 91%, respectively, for correctly differentiating between benign and malignant breast masses following a “positive” measurement (over the threshold value) and probabilities of disease as low as 10% and 11%, respectively, following a “negative” measurement (below the threshold value) when the pre-test probability was 50%. Conclusions SWE could be used as a good identification tool for the classification of breast masses. PMID:24204613

  11. Performance of shear wave elastography for differentiation of benign and malignant solid breast masses.

    Directory of Open Access Journals (Sweden)

    Guiling Li

    Full Text Available OBJECTIVES: To perform a meta-analysis assessing the ability of shear wave elastography (SWE to identify malignant breast masses. METHODS: PubMed, the Cochrane Library, and the ISI Web of Knowledge were searched for studies evaluating the accuracy of SWE for identifying malignant breast masses. The diagnostic accuracy of SWE was evaluated according to sensitivity, specificity, and hierarchical summary receiver operating characteristic (HSROC curves. An analysis was also performed according to the SWE mode used: supersonic shear imaging (SSI and the acoustic radiation force impulse (ARFI technique. The clinical utility of SWE for identifying malignant breast masses was evaluated using analysis of Fagan plot. RESULTS: A total of 9 studies, including 1888 women and 2000 breast masses, were analyzed. Summary sensitivities and specificities were 0.91 (95% confidence interval [CI], 0.88-0.94 and 0.82 (95% CI, 0.75-0.87 by SSI and 0.89 (95% CI, 0.81-0.94 and 0.91 (95% CI, 0.84-0.95 by ARFI, respectively. The HSROCs for SSI and ARFI were 0.92 (95% CI, 0.90-0.94 and 0.96 (95% CI, 0.93-0.97, respectively. SSI and ARFI were both very informative, with probabilities of 83% and 91%, respectively, for correctly differentiating between benign and malignant breast masses following a "positive" measurement (over the threshold value and probabilities of disease as low as 10% and 11%, respectively, following a "negative" measurement (below the threshold value when the pre-test probability was 50%. CONCLUSIONS: SWE could be used as a good identification tool for the classification of breast masses.

  12. Performance of shear wave elastography for differentiation of benign and malignant solid breast masses.

    Science.gov (United States)

    Li, Guiling; Li, De-Wei; Fang, Yu-Xiao; Song, Yi-Jiang; Deng, Zhu-Jun; Gao, Jian; Xie, Yan; Yin, Tian-Sheng; Ying, Li; Tang, Kai-Fu

    2013-01-01

    To perform a meta-analysis assessing the ability of shear wave elastography (SWE) to identify malignant breast masses. PubMed, the Cochrane Library, and the ISI Web of Knowledge were searched for studies evaluating the accuracy of SWE for identifying malignant breast masses. The diagnostic accuracy of SWE was evaluated according to sensitivity, specificity, and hierarchical summary receiver operating characteristic (HSROC) curves. An analysis was also performed according to the SWE mode used: supersonic shear imaging (SSI) and the acoustic radiation force impulse (ARFI) technique. The clinical utility of SWE for identifying malignant breast masses was evaluated using analysis of Fagan plot. A total of 9 studies, including 1888 women and 2000 breast masses, were analyzed. Summary sensitivities and specificities were 0.91 (95% confidence interval [CI], 0.88-0.94) and 0.82 (95% CI, 0.75-0.87) by SSI and 0.89 (95% CI, 0.81-0.94) and 0.91 (95% CI, 0.84-0.95) by ARFI, respectively. The HSROCs for SSI and ARFI were 0.92 (95% CI, 0.90-0.94) and 0.96 (95% CI, 0.93-0.97), respectively. SSI and ARFI were both very informative, with probabilities of 83% and 91%, respectively, for correctly differentiating between benign and malignant breast masses following a "positive" measurement (over the threshold value) and probabilities of disease as low as 10% and 11%, respectively, following a "negative" measurement (below the threshold value) when the pre-test probability was 50%. SWE could be used as a good identification tool for the classification of breast masses.

  13. Detection of negative ions in glow discharge mass spectrometry for analysis of solid specimens

    DEFF Research Database (Denmark)

    Canulescu, Stela; Molchan, Igor S.; Tauziede, C.

    2010-01-01

    A new method is presented for elemental and molecular analysis of halogen-containing samples by glow discharge time-of-flight mass spectrometry, consisting of detection of negative ions from a pulsed RF glow discharge in argon. Analyte signals are mainly extracted from the afterglow regime...... be used to study the distribution of a tantalum fluoride layer within the anodized tantala layer. Further, comparison is made with data obtained using glow-discharge optical emission spectroscopy, where elemental fluorine can only be detected using a neon plasma. The ionization mechanisms responsible...... for the formation of negative ions in glow discharge time-of-flight mass spectrometry are briefly discussed....

  14. Determination of alpha activity and fissile mass content in solid waste by systems using neutron interrogation

    International Nuclear Information System (INIS)

    Romeyer Dherbey, J.; Lacruche, G.; Berne, R.; Auge, J.; Martin Deidier, L.; Butez, M.

    1990-01-01

    The Quantitative control (determination of heavy nuclides and alpha activity) of alpha radioactive wastes is necessary, particularly to determine if the waste is in accordance with the surface storage limits. In order to reduce the uncertainty on the alpha activity resulting from unknown isotopic composition, inhomogeneity of heavy nuclides in the matrix, combination of several methods is necessary. In the paper we present the Cadarache development work in the NDA of solid waste using the Californium shuffler, 14 Mev neutron generator, and also passive techniques such as neutron emission measurement and gamma spectrometry. Experimental systems combining active and passive methods are presented (COSAC, BANCO, DANAIDE, PROMETHEE)

  15. Automated solid-phase extraction of herbicides from water for gas chromatographic-mass spectrometric analysis

    Science.gov (United States)

    Meyer, M.T.; Mills, M.S.; Thurman, E.M.

    1993-01-01

    An automated solid-phase extraction (SPE) method was developed for the pre-concentration of chloroacetanilide and triazine herbicides, and two triazine metabolites from 100-ml water samples. Breakthrough experiments for the C18 SPE cartridge show that the two triazine metabolites are not fully retained and that increasing flow-rate decreases their retention. Standard curve r2 values of 0.998-1.000 for each compound were consistently obtained and a quantitation level of 0.05 ??g/l was achieved for each compound tested. More than 10,000 surface and ground water samples have been analyzed by this method.

  16. Mass and energy deposition effects of implanted ions on solid sodium formate

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xiangqin E-mail: clshao@mail.ipp.ac.cn; Shao Chunlin; Yao Jianming; Yu Zengliang

    2000-07-01

    Solid sodium formate was implanted by low energy N{sup +}, H{sup +}, and Ar{sup +} ions. Measured with electron paramagnetic resonance (EPR) and Fourier-transform infrared (FT-IR), it was observed that new -CH{sub 2}-, -CH{sub 3}- groups and COO{sup -} radical ion were produced in the implanted sodium formate. Analyzing with the highly sensitive ninhydrin reaction, it was found that a new -NH{sub 2} functional group was formed upon N{sup +} ion implantation, and its yield increased along with implantation dose but decreased with the ion's energy.

  17. Isotopic abundance measurements on solid nuclear-type samples by glow discharge mass spectrometry

    International Nuclear Information System (INIS)

    Betti, M.; Rasmussen, G.; Koch, L.

    1996-01-01

    A double-focusing glow discharge mass spectrometer (GDMS) installed in a glovebox for nuclear sample screening has been employed for isotopic measurements. Isotopic compositions of zirconium, silicon, lithium, boron, uranium and plutonium which are elements of nuclear concern have been determined. Interferences arising from the matrix sample and the discharge gas (Ar) for each of these elements are discussed. The GDMS results are compared with those from thermal ionization mass spectrometry (TIMS). For boron and lithium at μg/g-ng/g levels, the two methods gave results in good agreement. In samples containing uranium the isotopic composition obtained by GDMS was in agreement with those from TIMS independently of the enrichment. Attempts for the determination of plutonium isotopic composition were also made. In this case, due to the interferences of uranium at mass 238 and americium at mass 241, the GDMS raw data are complementary with those values obtained from physical non-destructive techniques. (orig.). With 2 figs., 4 tabs

  18. Influence of inlet velocity of air and solid particle feed rate on holdup mass and heat transfer characteristics in cyclone heat exchanger

    International Nuclear Information System (INIS)

    Mothilal, T.; Pitchandi, K.

    2015-01-01

    Present work elaborates the effect of inlet velocity of air and solid particle feed rate on holdup mass and heat transfer characteristics in a cyclone heat exchanger. The RNG k-ε turbulence model was adopted for modeling high turbulence flow and Discrete phase model (DPM) to track solid particles in a cyclone heat exchanger by ANSYS FLUENT software. The effect of inlet air velocity (5 to 25 m/s) and inlet solid particle feed rate of (0.2 to 2.5 g/s) at different particle diameter (300 to 500 μm) on holdup mass and heat transfer rate in cyclone heat exchanger was studied at air inlet temperature of 473 K. Results show that holdup mass and heat transfer rate increase with increase in inlet air velocity and inlet solid particle feed rate. Influence of solid particle feed rate on holdup mass has more significance. Experimental setup was built for high efficiency cyclone. Good agreement was found between experimental and simulation pressure drop. Empirical correlation was derived for dimensionless holdup mass and Nusselt number based on CFD data by regression technique. Correlation predicts dimensional holdup mass with +5% to -8% errors of experimental data and Nusselt number with +9% to -3%

  19. Influence of inlet velocity of air and solid particle feed rate on holdup mass and heat transfer characteristics in cyclone heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Mothilal, T. [T. J. S. Engineering College, Gummidipoond (India); Pitchandi, K. [Sri Venkateswara College of Engineering, Sriperumbudur (India)

    2015-10-15

    Present work elaborates the effect of inlet velocity of air and solid particle feed rate on holdup mass and heat transfer characteristics in a cyclone heat exchanger. The RNG k-ε turbulence model was adopted for modeling high turbulence flow and Discrete phase model (DPM) to track solid particles in a cyclone heat exchanger by ANSYS FLUENT software. The effect of inlet air velocity (5 to 25 m/s) and inlet solid particle feed rate of (0.2 to 2.5 g/s) at different particle diameter (300 to 500 μm) on holdup mass and heat transfer rate in cyclone heat exchanger was studied at air inlet temperature of 473 K. Results show that holdup mass and heat transfer rate increase with increase in inlet air velocity and inlet solid particle feed rate. Influence of solid particle feed rate on holdup mass has more significance. Experimental setup was built for high efficiency cyclone. Good agreement was found between experimental and simulation pressure drop. Empirical correlation was derived for dimensionless holdup mass and Nusselt number based on CFD data by regression technique. Correlation predicts dimensional holdup mass with +5% to -8% errors of experimental data and Nusselt number with +9% to -3%.

  20. Carbon nanotubes as adsorbent of solid-phase extraction and matrix for laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Pan, Chensong; Xu, Songyun; Zou, Hanfa; Guo, Zhong; Zhang, Yu; Guo, Baochuan

    2005-02-01

    A method with carbon nanotubes functioning both as the adsorbent of solid-phase extraction (SPE) and the matrix for matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) to analyze small molecules in solution has been developed. In this method, 10 microL suspensions of carbon nanotubes in 50% (vol/vol) methanol were added to the sample solution to extract analytes onto surface of carbon nanotubes because of their dramatic hydrophobicity. Carbon nanotubes in solution are deposited onto the bottom of tube with centrifugation. After removing the supernatant fluid, carbon nanotubes are suspended again with dispersant and pipetted directly onto the sample target of the MALDI-MS to perform a mass spectrometric analysis. It was demonstrated by analysis of a variety of small molecules that the resolution of peaks and the efficiency of desorption/ionization on the carbon nanotubes are better than those on the activated carbon. It is found that with the addition of glycerol and sucrose to the dispersant, the intensity, the ratio of signal to noise (S/N), and the resolution of peaks for analytes by mass spectrometry increased greatly. Compared with the previously reported method by depositing sample solution onto thin layer of carbon nanotubes, it is observed that the detection limit for analytes can be enhanced about 10 to 100 times due to solid-phase extraction of analytes in solution by carbon nanotubes. An acceptable result of simultaneously quantitative analysis of three analytes in solution has been achieved. The application in determining drugs spiked into urine has also been realized.

  1. Diagnostic performances of shear wave elastography: which parameter to use in differential diagnosis of solid breast masses?

    Science.gov (United States)

    Lee, Eun Jung; Jung, Hae Kyoung; Ko, Kyung Hee; Lee, Jong Tae; Yoon, Jung Hyun

    2013-07-01

    To evaluate which shear wave elastography (SWE) parameter proves most accurate in the differential diagnosis of solid breast masses. One hundred and fifty-six breast lesions in 139 consecutive women (mean age: 43.54 ± 9.94 years, range 21-88 years), who had been scheduled for ultrasound-guided breast biopsy, were included. Conventional ultrasound and SWE were performed in all women before biopsy procedures. Ultrasound BI-RADS final assessment and SWE parameters were recorded. Diagnostic performance of each SWE parameter was calculated and compared with those obtained when applying cut-off values of previously published data. Performance of conventional ultrasound and ultrasound combined with each parameter was also compared. Of the 156 breast masses, 120 (76.9 %) were benign and 36 (23.1 %) malignant. Maximum stiffness (Emax) with a cut-off of 82.3 kPa had the highest area under the receiver operating characteristics curve (Az) value compared with other SWE parameters, 0.860 (sensitivity 88.9 %, specificity 77.5 %, accuracy 80.1 %). Az values of conventional ultrasound combined with each SWE parameter showed lower (but not significantly) values than with conventional ultrasound alone. Maximum stiffness (82.3 kPa) provided the best diagnostic performance. However the overall diagnostic performance of ultrasound plus SWE was not significantly better than that of conventional ultrasound alone. • SWE offers new information over and above conventional breast ultrasound • Various SWE parameters were explored regarding distinction between benign and malignant lesions • An elasticity of 82.3 kPa appears optimal in differentiating solid breast masses • However, ultrasound plus SWE was not significantly better than conventional ultrasound alone.

  2. Computational Modelling of the Structural Integrity following Mass-Loss in Polymeric Charred Cellular Solids

    OpenAIRE

    J. P. M. Whitty; J. Francis; J. Howe; B. Henderson

    2014-01-01

    A novel computational technique is presented for embedding mass-loss due to burning into the ANSYS finite element modelling code. The approaches employ a range of computational modelling methods in order to provide more complete theoretical treatment of thermoelasticity absent from the literature for over six decades. Techniques are employed to evaluate structural integrity (namely, elastic moduli, Poisson’s ratios, and compressive brittle strength) of honeycomb systems known to approximate t...

  3. Mass dependence of spectral and angular distributions of Cherenkov radiation from relativistic isotopes in solid radiators and its possible application as mass selector

    Science.gov (United States)

    Bogdanov, O. V.; Rozhkova, E. I.; Pivovarov, Yu. L.; Kuzminchuk-Feuerstein, N.

    2018-02-01

    The first proof of principle experiment with a prototype of a Time-of-Flight (TOF) - Cherenkov detector of relativistic heavy ions (RHI) exploiting a liquid Iodine Naphthalene radiator has been performed at Cave C at GSI (Darmstadt, Germany). A conceptual design for a liquid Cherenkov detector was proposed as a prototype for the future TOF measurements at the Super-FRS by detection of total number of Cherenkov photons. The ionization energy loss of RHI in a liquid radiator decreases only slightly this number, while in a solid radiator changes sufficiently not the total number of ChR photons, but ChR angular and spectral distributions. By means of computer simulations, we showed that these distributions are very sensitive to the isotope mass, due to different stopping powers of isotopes with initial equal relativistic factors. The results of simulations for light (Li, Be) and heavy (Xe) isotopes at 500-1000 MeV/u are presented indicating the possibility to use the isotopic effect in ChR of RHI as the mass selector.

  4. On the feasibility of using satellite gravity observations for detecting large-scale solid mass transfer events

    Science.gov (United States)

    Peidou, Athina C.; Fotopoulos, Georgia; Pagiatakis, Spiros

    2017-10-01

    The main focus of this paper is to assess the feasibility of utilizing dedicated satellite gravity missions in order to detect large-scale solid mass transfer events (e.g. landslides). Specifically, a sensitivity analysis of Gravity Recovery and Climate Experiment (GRACE) gravity field solutions in conjunction with simulated case studies is employed to predict gravity changes due to past subaerial and submarine mass transfer events, namely the Agulhas slump in southeastern Africa and the Heart Mountain Landslide in northwestern Wyoming. The detectability of these events is evaluated by taking into account the expected noise level in the GRACE gravity field solutions and simulating their impact on the gravity field through forward modelling of the mass transfer. The spectral content of the estimated gravity changes induced by a simulated large-scale landslide event is estimated for the known spatial resolution of the GRACE observations using wavelet multiresolution analysis. The results indicate that both the Agulhas slump and the Heart Mountain Landslide could have been detected by GRACE, resulting in {\\vert }0.4{\\vert } and {\\vert }0.18{\\vert } mGal change on GRACE solutions, respectively. The suggested methodology is further extended to the case studies of the submarine landslide in Tohoku, Japan, and the Grand Banks landslide in Newfoundland, Canada. The detectability of these events using GRACE solutions is assessed through their impact on the gravity field.

  5. Mass Transfer Process by Magneto-convection at a Solid-liquid Interface in a Heterogeneous Vertical Magnetic Field

    Science.gov (United States)

    Sugiyama, Atsushi; Morisaki, Shigeyoshi; Aogaki, Ryoichi

    2003-08-01

    When an external magnetic field is vertically imposed on a solid-liquid interface, the mass transfer process of a solute dissolving from or depositing on the interface was theoretically examined. In a heterogeneous vertical magnetic field, a material receives a magnetic force in proportion to the product of the magnetic susceptibility, the magnetic flux density B and its gradient (dB/dz). As the reaction proceeds, a diffusion layer of the solute with changing susceptibility is formed at the interface because of the difference of the the magnetic susceptibility on the concentration of the solute. In the case of an unstable condition where the dimensionless number of magneto-convection S takes a positive value, the magnetic force is applied to the layer and induces numerous minute convection cells. The mass transfer of the solute is thus accelerated, so that it is predicted that the mass flux increases with the 1/3rd order of B(dB/dz) and the 4/3rd order of the concentration. The experiment was then performed by measuring the rate of the dissolution of copper sulfate pentahydrate crystal in water.

  6. Mass

    International Nuclear Information System (INIS)

    Quigg, Chris

    2007-01-01

    In the classical physics we inherited from Isaac Newton, mass does not arise, it simply is. The mass of a classical object is the sum of the masses of its parts. Albert Einstein showed that the mass of a body is a measure of its energy content, inviting us to consider the origins of mass. The protons we accelerate at Fermilab are prime examples of Einsteinian matter: nearly all of their mass arises from stored energy. Missing mass led to the discovery of the noble gases, and a new form of missing mass leads us to the notion of dark matter. Starting with a brief guided tour of the meanings of mass, the colloquium will explore the multiple origins of mass. We will see how far we have come toward understanding mass, and survey the issues that guide our research today.

  7. Determination of quaternary ammonium compounds in seawater samples by solid-phase extraction and liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Bassarab, P; Williams, D; Dean, J R; Ludkin, E; Perry, J J

    2011-02-04

    A method for the simultaneous determination of two biocidal quaternary ammonium compounds; didecyldimethylammonium chloride (didecyldimethyl quat) and dodecylbenzyldimethylammonium chloride (benzyl quat), in seawater by solid phase extraction (SPE) followed by liquid chromatography-mass spectrometry (LC-MS) was developed. The optimised procedure utilised off-line extraction of the analytes from seawater using polymeric (Strata-X) SPE cartridges. Recoveries ranged from 80 to 105%, with detection limits at the low parts-per-trillion (ng/l) level for both analytes. To demonstrate sensitivity, environmental concentrations were measured at three different locations along the North East coast of England with measured values in the range 120-270ng/l. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. Generic solid phase extraction-liquid chromatography-tandem mass spectrometry method for fast determination of drugs in biological fluids.

    Science.gov (United States)

    Schellen, Anniek; Ooms, Bert; van de Lagemaat, Dick; Vreeken, Rob; van Dongen, William D

    2003-05-25

    A generic method was developed for the fast determination of a wide range of drugs in serum or plasma. The methodology comprises generic solid-phase extraction, on-line coupled to gradient HPLC with tandem mass spectrometric detection (SPE-LC-MS/MS). The individual components of the SPE-LC-MS/MS system were optimized in an integrated approach to maximize the application range and minimize the method development time. The optimized generic SPE-LC-MS/MS protocol was evaluated for 11 drugs with different physicochemical properties. Good quantification for 10 out of 11 of the pharmaceuticals in serum or plasma could be readily achieved. The quantitative assays gave recoveries better than 95%, lower quantification limits of 0.2-2.0 ng/ml, acceptable precision and accuracy and good linearity over 2-4 orders of magnitude. Carry-over was determined to be in the range of 0.02-0.10%, without optimization.

  9. Determination of some volatile compounds in alcoholic beverage by headspace solid-phase microextraction gas chromatography - mass spectrometry

    Science.gov (United States)

    Schmutzer, G.; Avram, V.; Feher, I.; David, L.; Moldovan, Z.

    2012-02-01

    The volatile composition of alcoholic beverage was studied by headspace solid-phase microextraction (HSSPME) method and gas chromatography - mass spectrometry (GC-MS). Some volatile compounds, such as alcohols, esters, terpenes and other are mainly responsible for the flavor of fortified wines and their amounts specify the quality of the alcoholic beverages. From this perspective it is interesting to develop a rapid, selective and sensitive analytical method suitable for simultaneous quantification of the main molecules being responsible for the organoleptic characteristic of alcoholic beverages. Vermouth fortified drink was analyzed in order to characterize the volatile profile. Using the HS-SPME/GC-MS a number of twenty-six volatile compounds from a commercial market alcoholic beverage were identified. The most abundant compounds were m-thymol, o-thymol and eugenol, alongside of the ethyl ester compounds.

  10. Enhanced mass transfer during solid-liquid extraction of gamma-irradiated red beetroot

    International Nuclear Information System (INIS)

    Nayak, Chetan A.; Chethana, S.; Rastogi, N.K.; Raghavarao, K.S.M.S.

    2006-01-01

    The exposure to gamma-irradiation pretreatment increases cell wall permeabilization, resulting in loss of turgor pressure, which led to the increase of extractability of betanin from red beetroot. The degree of extraction of betanin was investigated using gamma irradiation as a pretreatment prior to the solid-liquid extraction process and compared with control beetroot samples. The beetroot subjected to different doses of gamma irradiation (2.5, 5.0, 7.5, 10.0 kGy) and control was dipped in an acetic acid medium (1% v/v) to extract the betanin. The diffusion coefficients for betanin as well as ionic component were estimated considering Fickian diffusion. The results indicated an increase in the diffusion coefficient of betanin (0.302x10 -9 -0.463x10 -9 m 2 /s) and ionic component (0.248x10 -9 -0.453x10 -9 m 2 /s) as the dose rate increased (from 2.5 to 10.0 kGy). The degradation constant was found to increase (0.050-0.079 min -1 ) with an increase gamma-irradiation doses (2.5-10.0 kGy), indicating lower stability of the betanin as compared to control sample at 65 deg. C

  11. Mass and Heat Transfer in Ion-Exchange Membranes Applicable to Solid Polymer Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Otteroey, M

    1996-04-01

    In this doctoral thesis, an improved emf method for determination of transference numbers of two counter ions in ion-exchange membranes is presented. Transference numbers were obtained as a continuous function of the composition. The method avoids problems with diffusion by using a stack of membranes. Water transference coefficients in ion-exchange membranes is discussed and reversible and irreversible water transfer is studied by emf methods. Efforts were made to get data relevant to the solid polymer fuel cell. The results support the findings of other researchers that the reversible water transfer is lower than earlier predicted. A chapter on the conductivity of ion-exchange membranes establishes a method to separate the very thin liquid layers surrounding the membranes in a stack. Using the method it was found that the conductivity is obtained with high accuracy and that the liquid layer in a membrane stack can contribute significantly to the total measured resistance. A four point impedance method was tested to measure the conductivity of membranes under fuel cell conditions. Finally, there is a discussion of reversible heat effects and heat transfer in ion-exchange membranes. 155 refs., 45 figs., 13 tabs.

  12. [Determination of short chain chlorinated paraffins in leather products by solid phase extraction coupled with gas chromatography-mass spectrometry].

    Science.gov (United States)

    Zhang, Weiya; Wan, Xin; Li, Lixia; Wang, Chengyun; Jin, Shupei; Xing, Jun

    2014-10-01

    The short chain chlorinated paraffins (SCCPs) are the additives frequently used in the leather production in China, but they have been put into the list of forbidden chemicals issued by European Union recently. In fact, there is not a commonly recognized method for the determination of the SCCPs in the leather products due to the serious matrix interferences from the leather products and the complex chemical structures of the SCCPs. A method of solid phase extraction coupled with gas chromatography-mass spectrometry (SPE-GC-MS) was established for the determination of the SCCPs in the leather products after the optimization of the SPE conditions. It was found that the interferences from the leather products were thor- oughly separated from the analyte of the SCCPs on a home-made solid phase extraction (SPE) column filled with silica packing while eluted with a mixed solvent of n-hexane-methylene chloride (2:1, v/v). With this method, the recoveries for the SCCPs spiked in the real leather samples varied from 90.47% to 99.00% with the relative standard deviations (RSDs) less than 6.7%, and the limits of detection (LODs) were between 0.069 and 0.110 mg/kg. This method is suitable for qualitative and quantitative analysis of SCCPs in the leather products.

  13. Subtype Differentiation of Small (≤ 4 cm) Solid Renal Mass Using Volumetric Histogram Analysis of DWI at 3-T MRI.

    Science.gov (United States)

    Li, Anqin; Xing, Wei; Li, Haojie; Hu, Yao; Hu, Daoyu; Li, Zhen; Kamel, Ihab R

    2018-05-29

    The purpose of this article is to evaluate the utility of volumetric histogram analysis of apparent diffusion coefficient (ADC) derived from reduced-FOV DWI for small (≤ 4 cm) solid renal mass subtypes at 3-T MRI. This retrospective study included 38 clear cell renal cell carcinomas (RCCs), 16 papillary RCCs, 18 chromophobe RCCs, 13 minimal fat angiomyolipomas (AMLs), and seven oncocytomas evaluated with preoperative MRI. Volumetric ADC maps were generated using all slices of the reduced-FOV DW images to obtain histogram parameters, including mean, median, 10th percentile, 25th percentile, 75th percentile, 90th percentile, and SD ADC values, as well as skewness, kurtosis, and entropy. Comparisons of these parameters were made by one-way ANOVA, t test, and ROC curves analysis. ADC histogram parameters differentiated eight of 10 pairs of renal tumors. Three subtype pairs (clear cell RCC vs papillary RCC, clear cell RCC vs chromophobe RCC, and clear cell RCC vs minimal fat AML) were differentiated by mean ADC. However, five other subtype pairs (clear cell RCC vs oncocytoma, papillary RCC vs minimal fat AML, papillary RCC vs oncocytoma, chromophobe RCC vs minimal fat AML, and chromophobe RCC vs oncocytoma) were differentiated by histogram distribution parameters exclusively (all p histogram parameters yielded the highest AUC (0.851; sensitivity, 80.0%; specificity, 86.1%). Quantitative volumetric ADC histogram analysis may help differentiate various subtypes of small solid renal tumors, including benign and malignant lesions.

  14. Determination of chlorinated polycyclic aromatic hydrocarbons in water by solid-phase extraction coupled with gas chromatography and mass spectrometry.

    Science.gov (United States)

    Wang, Xianli; Kang, Haiyan; Wu, Junfeng

    2016-05-01

    Given the potential risks of chlorinated polycyclic aromatic hydrocarbons, the analysis of their presence in water is very urgent. We have developed a novel procedure for determining chlorinated polycyclic aromatic hydrocarbons in water based on solid-phase extraction coupled with gas chromatography and mass spectrometry. The extraction parameters of solid-phase extraction were optimized in detail. Under the optimal conditions, the proposed method showed wide linear ranges (1.0-1000 ng/L) with correlation coefficients ranging from 0.9952 to 0.9998. The limits of detection and the limits of quantification were in the range of 0.015-0.591 and 0.045-1.502 ng/L, respectively. Recoveries ranged from 82.5 to 102.6% with relative standard deviations below 9.2%. The obtained method was applied successfully to the determination of chlorinated polycyclic aromatic hydrocarbons in real water samples. Most of the chlorinated polycyclic aromatic hydrocarbons were detected and 1-monochloropyrene was predominant in the studied water samples. This is the first report of chlorinated polycyclic aromatic hydrocarbons in water samples in China. The toxic equivalency quotients of chlorinated polycyclic aromatic hydrocarbons in the studied tap water were 9.95 ng the toxic equivalency quotient m(-3) . 9,10-Dichloroanthracene and 1-monochloropyrene accounted for the majority of the total toxic equivalency quotients of chlorinated polycyclic aromatic hydrocarbons in tap water. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Determination of amphetamine-type stimulants in oral fluid by solid-phase microextraction and gas chromatography-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Daniele Z., E-mail: daniele.dzs@dpf.gov.br [Setor Tecnico-Cientifico, Superintendencia Regional do Departamento de Policia Federal no Rio Grande do Sul, 1365 Ipiranga Avenue, Azenha, Zip Code 90160-093 Porto Alegre, Rio Grande do Sul (Brazil); Programa de Pos-Graduacao em Ciencias Farmaceuticas, Faculdade de Farmacia, Universidade Federal do Rio Grande do Sul, 2752 Ipiranga Avenue, Santana, Zip Code 90610-000 Porto Alegre, Rio Grande do Sul (Brazil); Boehl, Paula O.; Comiran, Eloisa; Mariotti, Kristiane C. [Programa de Pos-Graduacao em Ciencias Farmaceuticas, Faculdade de Farmacia, Universidade Federal do Rio Grande do Sul, 2752 Ipiranga Avenue, Santana, Zip Code 90610-000 Porto Alegre, Rio Grande do Sul (Brazil); Pechansky, Flavio [Centro de Pesquisa em Alcool e Drogas (CPAD), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, 2350, Ramiro Barcelos Street, Zip Code 90035-903 Porto Alegre, Rio Grande do Sul (Brazil); Duarte, Paulina C.A.V. [Secretaria Nacional de Politicas sobre Drogas (SENAD), Esplanada dos Ministerios, Block ' A' , 5th floor, Zip Code 70050-907 Brasilia, Distrito Federal (Brazil); De Boni, Raquel [Centro de Pesquisa em Alcool e Drogas (CPAD), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, 2350, Ramiro Barcelos Street, Zip Code 90035-903 Porto Alegre, Rio Grande do Sul (Brazil); Froehlich, Pedro E.; Limberger, Renata P. [Programa de Pos-Graduacao em Ciencias Farmaceuticas, Faculdade de Farmacia, Universidade Federal do Rio Grande do Sul, 2752 Ipiranga Avenue, Santana, Zip Code 90610-000 Porto Alegre, Rio Grande do Sul (Brazil)

    2011-06-24

    Graphical abstract: Highlights: > Propylchloroformate derivatization of amphetamine-type stimulants in oral fluid. > Direct immersion solid-phase microextraction/gas chromatography-mass spectrometry. > Linear range 2(4)-256 ng mL{sup -1}, detection limits 0.5-2 ng mL{sup -1}. > Accuracy 98-112%, precision <15% of RSD, recovery 77-112%. > Importance of residual evaluation in checking model goodness-of-fit. - Abstract: A method for the simultaneous identification and quantification of amphetamine (AMP), methamphetamine (MET), fenproporex (FEN), diethylpropion (DIE) and methylphenidate (MPH) in oral fluid collected with Quantisal{sup TM} device has been developed and validated. Thereunto, in-matrix propylchloroformate derivatization followed by direct immersion solid-phase microextraction and gas chromatography-mass spectrometry were employed. Deuterium labeled AMP was used as internal standard for all the stimulants and analysis was performed using the selected ion monitoring mode. The detector response was linear for the studied drugs in the concentration range of 2-256 ng mL{sup -1} (neat oral fluid), except for FEN, whereas the linear range was 4-256 ng mL{sup -1}. The detection limits were 0.5 ng mL{sup -1} (MET), 1 ng mL{sup -1} (MPH) and 2 ng mL{sup -1} (DIE, AMP, FEN), respectively. Accuracy of quality control samples remained within 98.2-111.9% of the target concentrations, while precision has not exceeded 15% of the relative standard deviation. Recoveries with Quantisal{sup TM} device ranged from 77.2% to 112.1%. Also, the goodness-of-fit concerning the ordinary least squares model in the statistical inference of data has been tested through residual plotting and ANOVA. The validated method can be easily automated and then used for screening and confirmation of amphetamine-type stimulants in drivers' oral fluid.

  16. Determination of amphetamine-type stimulants in oral fluid by solid-phase microextraction and gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    Souza, Daniele Z.; Boehl, Paula O.; Comiran, Eloisa; Mariotti, Kristiane C.; Pechansky, Flavio; Duarte, Paulina C.A.V.; De Boni, Raquel; Froehlich, Pedro E.; Limberger, Renata P.

    2011-01-01

    Graphical abstract: Highlights: → Propylchloroformate derivatization of amphetamine-type stimulants in oral fluid. → Direct immersion solid-phase microextraction/gas chromatography-mass spectrometry. → Linear range 2(4)-256 ng mL -1 , detection limits 0.5-2 ng mL -1 . → Accuracy 98-112%, precision TM device has been developed and validated. Thereunto, in-matrix propylchloroformate derivatization followed by direct immersion solid-phase microextraction and gas chromatography-mass spectrometry were employed. Deuterium labeled AMP was used as internal standard for all the stimulants and analysis was performed using the selected ion monitoring mode. The detector response was linear for the studied drugs in the concentration range of 2-256 ng mL -1 (neat oral fluid), except for FEN, whereas the linear range was 4-256 ng mL -1 . The detection limits were 0.5 ng mL -1 (MET), 1 ng mL -1 (MPH) and 2 ng mL -1 (DIE, AMP, FEN), respectively. Accuracy of quality control samples remained within 98.2-111.9% of the target concentrations, while precision has not exceeded 15% of the relative standard deviation. Recoveries with Quantisal TM device ranged from 77.2% to 112.1%. Also, the goodness-of-fit concerning the ordinary least squares model in the statistical inference of data has been tested through residual plotting and ANOVA. The validated method can be easily automated and then used for screening and confirmation of amphetamine-type stimulants in drivers' oral fluid.

  17. A fully automated mass spectrometer for the analysis of organic solids

    International Nuclear Information System (INIS)

    Hillig, H.; Kueper, H.; Riepe, W.

    1979-01-01

    Automation of a mass spectrometer-computer system makes it possible to process up to 30 samples without attention after sample loading. An automatic sample changer introduces the samples successively into the ion source by means of a direct inlet probe. A process control unit determines the operation sequence. Computer programs are available for the hardware support, system supervision and evaluation of the spectrometer signals. The most essential precondition for automation - automatic evaporation of the sample material by electronic control of the total ion current - is confirmed to be satisfactory. The system operates routinely overnight in an industrial laboratory, so that day work can be devoted to difficult analytical problems. The cost of routine analyses is halved. (Auth.)

  18. Wavelets analysis for differentiating solid, non-macroscopic fat containing, enhancing renal masses: a pilot study

    Science.gov (United States)

    Varghese, Bino; Hwang, Darryl; Mohamed, Passant; Cen, Steven; Deng, Christopher; Chang, Michael; Duddalwar, Vinay

    2017-11-01

    Purpose: To evaluate potential use of wavelets analysis in discriminating benign and malignant renal masses (RM) Materials and Methods: Regions of interest of the whole lesion were manually segmented and co-registered from multiphase CT acquisitions of 144 patients (98 malignant RM: renal cell carcinoma (RCC) and 46 benign RM: oncocytoma, lipid-poor angiomyolipoma). Here, the Haar wavelet was used to analyze the grayscale images of the largest segmented tumor in the axial direction. Six metrics (energy, entropy, homogeneity, contrast, standard deviation (SD) and variance) derived from 3-levels of image decomposition in 3 directions (horizontal, vertical and diagonal) respectively, were used to quantify tumor texture. Independent t-test or Wilcoxon rank sum test depending on data normality were used as exploratory univariate analysis. Stepwise logistic regression and receiver operator characteristics (ROC) curve analysis were used to select predictors and assess prediction accuracy, respectively. Results: Consistently, 5 out of 6 wavelet-based texture measures (except homogeneity) were higher for malignant tumors compared to benign, when accounting for individual texture direction. Homogeneity was consistently lower in malignant than benign tumors irrespective of direction. SD and variance measured in the diagonal direction on the corticomedullary phase showed significant (p<0.05) difference between benign versus malignant tumors. The multivariate model with variance (3 directions) and SD (vertical direction) extracted from the excretory and pre-contrast phase, respectively showed an area under the ROC curve (AUC) of 0.78 (p < 0.05) in discriminating malignant from benign. Conclusion: Wavelet analysis is a valuable texture evaluation tool to add to a radiomics platforms geared at reliably characterizing and stratifying renal masses.

  19. Pharmaceutical powder compaction technology

    National Research Council Canada - National Science Library

    Çelik, Metin

    2011-01-01

    ... through the compaction formulation process and application. Compaction of powder constituents both active ingredient and excipients is examined to ensure consistent and reproducible disintegration and dispersion profiles...

  20. Quantum statistical effects in the mass transport of interstitial solutes in a crystalline solid

    Science.gov (United States)

    Woo, C. H.; Wen, Haohua

    2017-09-01

    The impact of quantum statistics on the many-body dynamics of a crystalline solid at finite temperatures containing an interstitial solute atom (ISA) is investigated. The Mori-Zwanzig theory allows the many-body dynamics of the crystal to be formulated and solved analytically within a pseudo-one-particle approach using the Langevin equation with a quantum fluctuation-dissipation relation (FDR) based on the Debye model. At the same time, the many-body dynamics is also directly solved numerically via the molecular dynamics approach with a Langevin heat bath based on the quantum FDR. Both the analytical and numerical results consistently show that below the Debye temperature of the host lattice, quantum statistics significantly impacts the ISA transport properties, resulting in major departures from both the Arrhenius law of diffusion and the Einstein-Smoluchowski relation between the mobility and diffusivity. Indeed, we found that below one-third of the Debye temperature, effects of vibrations on the quantum mobility and diffusivity are both orders-of-magnitude larger and practically temperature independent. We have shown that both effects have their physical origin in the athermal lattice vibrations derived from the phonon ground state. The foregoing theory is tested in quantum molecular dynamics calculation of mobility and diffusivity of interstitial helium in bcc W. In this case, the Arrhenius law is only valid in a narrow range between ˜300 and ˜700 K. The diffusivity becomes temperature independent on the low-temperature side while increasing linearly with temperature on the high-temperature side.

  1. Characterization of benign and malignant solid breast masses in harmonic 3D power Doppler imaging

    International Nuclear Information System (INIS)

    Hsiao, Y.-H.; Huang, Y.-L.; Kuo, S.-J.; Liang, W.-M.; Chen, S.-T.; Chen, D.-R.

    2009-01-01

    Purpose: The authors assessed the characteristics of benign and malignant solid breast tumors in harmonic three-dimensional (3D) power Doppler imaging and proposed decision models to classify benign and malignant breast tumors. Materials and methods: A total of 86 malignant and 97 benign harmonic 3D power Doppler US images were analyzed. All the harmonic 3D power Doppler images were obtained using a Voluson730 US system (GE, Zipf, Austria) equipped with a RSP 6-12 transducer and tissue harmonic imaging modalities. Imaging analysis was performed using the Virtual Organ Computer-aided Analysis (VOCAL)-imaging program. Histogram indices, the vascularization index (VI), flow index (FI) and vascularization-flow index (VFI), were calculated for the intra-tumor and for shells with an outside thickness of 3 mm surrounding the breast tumors. The receiver operating characteristic (ROC) curves were calculated to estimate the diagnostic performances. Results: The results revealed that the choice of decision model comprised the parameters of patient age, intra-tumor VI, and tumor volume to classify benign and malignant breast tumors. The area under the ROC curve (Az) was 0.910, accuracy was 81.4%, and sensitivity and specificity were 81.4% and 81.4%, respectively. The parameter intra-tumor VI was the choice for all of the histogram indices in differentiating between malignant and benign lesions. Conclusion: The decision model, which was composed of patient age, tumor volume and intra-tumor VI, and a cut-off value for intra-tumor VI at the upper end of patient age and tumor volume, was recommended in clinical application.

  2. Development and application of compact denuder sampling techniques with in situ derivatization followed by gas chromatography-mass spectrometry for halogen speciation in volcanic plumes

    Science.gov (United States)

    Rüdiger, Julian; Bobrowski, Nicole; Hoffmann, Thorsten

    2015-04-01

    spectrometry gives a limit of detection below 1 ng of bromine. The method was applied on volcanic gas plumes at Mt. Etna and Mt. Stromboli in Italy in July 2014 and on fumarolic gas emissions at Mt. Lastarria in Chile in November 2014. The results show significant amounts of the concerning bromine species (lower ppb range). Comprehensive data evaluation and comparison with results of impinger extraction with NaOH solution as well as chamber experiments are still in progress. References Bobrowski, N. and G. Giuffrida: Bromine monoxide / sulphur dioxide ratios in relation to volcanological observations at Mt. Etna 2006-2009. Solid Earth, 3, 433-445, 2012 Bobrowski, N., R. von Glasow, A. Aiuppa, S. Inguaggiato, I. Louban, O. W. Ibrahim and U. Platt: Reactive halogen chemistry in volcanic plumes. J. Geophys. Res., 112, 2007 Donovan A., V. Tsanev, C. Oppenheimer and M. Edmonds: Reactive halogens (BrO and OClO) detected in the plume of Soufrière Hills Volcano during an eruption hiatus. Geochem. Geophys. Geosyst., 15, 3346-3363, 2014 Huang, R.-J. and T. Hoffmann: A denuder-impinger system with in situ derivatization followed by gas chromatography-mass spectrometry for the determination of gaseous iodine-containing halogen species. Journal of Chromatography A, 1210, 135-141, 2008

  3. A Compact, Solid-State UV (266 nm) Laser System Capable of Burst-Mode Operation for Laser Ablation Desorption Processing

    Science.gov (United States)

    Arevalo, Ricardo, Jr.; Coyle, Barry; Paulios, Demetrios; Stysley, Paul; Feng, Steve; Getty, Stephanie; Binkerhoff, William

    2015-01-01

    Compared to wet chemistry and pyrolysis techniques, in situ laser-based methods of chemical analysis provide an ideal way to characterize precious planetary materials without requiring extensive sample processing. In particular, laser desorption and ablation techniques allow for rapid, reproducible and robust data acquisition over a wide mass range, plus: Quantitative, spatially-resolved measurements of elemental and molecular (organic and inorganic) abundances; Low analytical blanks and limits-of-detection ( ng g-1); and, the destruction of minimal quantities of sample ( g) compared to traditional solution and/or pyrolysis analyses (mg).

  4. Analysis of a rhenium-osmium solid-solution spike by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Richardson, J.M.; Dickin, A.P.; McNutt, R.H.; McAndrew, J.I.; Beneteau, S.B.

    1989-01-01

    The rhenium-osmium decay scheme ( 187 Re → 187 Os) offers a unique opportunity to investigate the genesis of, and directly date, ultramafic rock, sulphide and platinum ore deposits. Inductively coupled plasma mass spectrometry (ICP-MS) is a viable method for Os isotopic analysis as it provides the high temperatures necessary to ionise Os. The sample can be introduced into the ICP mass spectrometer either by conventional nebulisation or by distillation using an Os ''generator''. Generator-mode analysis is superior to nebulisation because (i) the total number of counts is two orders of magnitude higher for a given sample size and (ii) Os oxidises readily to volatile OsO 4 , which has a boiling-point lower than most Re compounds, so that Os can be efficiently separated from 187 Re. The importance of Os loss during sample preparation was minimised by combining the sample powder with a powdered Re-Os isotopic spike prior to any chemical treatment. The spike is in a nickel sulphide matrix and was made by a thioacetamide co-precipitation of Os, Re and Ni followed by a fire assay. The 190 Os/ 192 Os ratio in this preparation is 51.5 ± 0.9, the 187 Os 188 Os ratio is 0.063 ± 0.006 and the 185 Re/ 187 Re ratio is 17.04 - + 0.41. These values are within the error limits quoted by the Oak Ridge National Laboratory and Techsnabexport, the suppliers of the metallic spikes. Parameters that significantly influence the Os analyses include the oxidising agent and the run temperature. The oxidising agent H 5 IO 6 is preferred to H 2 O 2 or HNO 3 as it has the highest electrode potential, provides a prolonged, consistent reaction and is more stable when stored. Chilling the sample and the H 5 IO 6 , initially retards uncontrolled OsO 4 emission. Heat applied later in the run releases OsO 4 and helps maintain a high count rate. Thus, OsO 4 can be generated in a steady, controllable and reproducible manner. (author)

  5. Physicochemical effects of cosmic rays in solids: analyses by mass spectrometry and by infrared spectroscopy

    International Nuclear Information System (INIS)

    Silveira, Enio F. da

    2012-01-01

    Full text: Cosmic Rays (CR) are studied since their discovery by Victor Hess in the years 1911-1913. Interestingly, the beginning of research in Physics in Brazil started with experiments on CR. B. Gross (INT/ Rio), G. Wataghin and G. Occhialini (USP) started their investigation on CR in 1934. F.X. Roser, the founder of the Physics Institute of PUC-Rio, worked with Hess when he got the Nobel Prize in 1936. C. Lattes got in 1947 the experimental data in Chacaltaya that conducted to the discovery of the meson pi (C. Powell, Nobel Prize in 1950). Nowadays, the Auger Project deals with extremely high energy extragalactic particles. Except for these ones, the origin, the energy and mass distributions of CR constituents and their capability of producing elementary particles are well known. Nevertheless, there is an enormous lack of information on the effects caused by the CR on inorganic and biological materials. This motivates measurements of relevant physicochemical data, such as sputtering yields, cross sections for inducing chemical reactions and crystalline structure parameters. A fascinating question about CR is if they are/were the responsible for the transformation of inorganic into organic material, synthesizing therefore pre-biotic molecules in whole Universe. Nuclear Physics instrumentation is well suited to answer this question, providing ion sources and ion accelerators from keV to GeV. Time-of-flight mass spectrometry and FTIR infrared spectroscopy are techniques able to monitor the physicochemical modifications induced by the RC beam analogs. Data obtained in the GANIL (France) and Van de Graaff (PUC-Rio) accelerators are presented. Abundant inorganic molecular species in space, such as H 2 O, CO, CO 2 and NH 3 , are condensed in laboratory and bombarded by H to Fe ions, from 10 -3 to 10 3 MeV/u, covering the CR range. New chemical species are identified; sputtering yields (Y), formation (σf ) and destruction (σd) cross sections are measured. An

  6. Compact magnetic fusion systems

    Energy Technology Data Exchange (ETDEWEB)

    Linford, R.K.

    1983-12-01

    If the core (first wall, blanket, shield, and magnet coils) of fusion reactor systems could be made smaller in mass and volume for a given net electric power output than is usually predicted for the mainline tokamak/sup 1/ and mirror concepts, the cost of the technological development of the core and the construction of power plants might be significantly reduced. Although progress in plasma physics and engineering approaches should continue to yield improvements in reactor designs, certain physics features of the mainline concepts may prevent major reductions in the size of the core without straining the limits of technology. However, more than a factor of ten reduction in volume and mass of the core, at constant output power, may be possible for a class of toroidal confinement concepts in which the confining magnetic fields are supported more by currents flowing in the plasma than those in the external coils. In spite of this dramatic increase in power density (ratio of total thermal output power to the volume of the core), the design of compact systems need not rely on any materials requirements that are qualitatively more difficult than those proposed for the lower-power-density mainline fusion concepts. In some respects compact systems require less of an extension of existing technology, e.g. magnetics.

  7. Compact magnetic fusion systems

    International Nuclear Information System (INIS)

    Linford, R.K.

    1983-01-01

    If the core (first wall, blanket, shield, and magnet coils) of fusion reactor systems could be made smaller in mass and volume for a given net electric power output than is usually predicted for the mainline tokamak 1 and mirror concepts, the cost of the technological development of the core and the construction of power plants might be significantly reduced. Although progress in plasma physics and engineering approaches should continue to yield improvements in reactor designs, certain physics features of the mainline concepts may prevent major reductions in the size of the core without straining the limits of technology. However, more than a factor of ten reduction in volume and mass of the core, at constant output power, may be possible for a class of toroidal confinement concepts in which the confining magnetic fields are supported more by currents flowing in the plasma than those in the external coils. In spite of this dramatic increase in power density (ratio of total thermal output power to the volume of the core), the design of compact systems need not rely on any materials requirements that are qualitatively more difficult than those proposed for the lower-power-density mainline fusion concepts. In some respects compact systems require less of an extension of existing technology, e.g. magnetics

  8. Diffusion in compacted betonite

    International Nuclear Information System (INIS)

    Muurinen, A.; Rantanen, J.

    1985-01-01

    The objective of this report is to collect the literature bearing on the diffusion in compacted betonite, which has been suggested as possible buffer material for the disposal of spent fuel. Diffusion in a porous, water-saturated material is usually described as diffusion in the pore-water where sorption on the solid matter can delay the migration in the instationary state. There are also models which take into consideration that the sorbed molecules can also move while being sorbed. Diffusion experiments in compacted bentonite have been reported by many authors. Gases, anions, cations and actinides have been used as diffusing molecules. The report collects the results and the information on the measurement methods. On the basis of the results can be concluded that different particles possibly follow different diffusion mechanisms. The parameters which affect the diffusion seem to be for example the size, the electric charge and the sorption properties of the diffusing molecule. The report also suggest the parameters to be used in the diffusion calculation of the safety analyses of spent fuel disposal. (author)

  9. Compact Infrasonic Windscreen

    Science.gov (United States)

    Zuckerwar, Allan J.; Shams, Qamar A.; Sealey, Bradley S.; Comeaux, Toby

    2005-01-01

    A compact windscreen has been conceived for a microphone of a type used outdoors to detect atmospheric infrasound from a variety of natural and manmade sources. Wind at the microphone site contaminates received infrasonic signals (defined here as sounds having frequencies <20 Hz), because a microphone cannot distinguish between infrasonic pressures (which propagate at the speed of sound) and convective pressure fluctuations generated by wind turbulence. Hence, success in measurement of outdoor infrasound depends on effective screening of the microphone from the wind. The present compact windscreen is based on a principle: that infrasound at sufficiently large wavelength can penetrate any barrier of practical thickness. Thus, a windscreen having solid, non-porous walls can block convected pressure fluctuations from the wind while transmitting infrasonic acoustic waves. The transmission coefficient depends strongly upon the ratio between the acoustic impedance of the windscreen and that of air. Several materials have been found to have impedance ratios that render them suitable for use in constructing walls that have practical thicknesses and are capable of high transmission of infrasound. These materials (with their impedance ratios in parentheses) are polyurethane foam (222), space shuttle tile material (332), balsa (323), cedar (3,151), and pine (4,713).

  10. Compact cryocooler heat exchangers

    International Nuclear Information System (INIS)

    Luna, J.; Frederking, T.H.K.

    1991-01-01

    Compact heat exchangers are subject to different constraints as a room temperature gas is cooled down by a cold stream returning from a JT valve (or a similar cryoprocess component). In particular, the optimization of exchangers for liquid helium systems has to cover a wide range in temperature and density of the fluid. In the present work we address the following thermodynamic questions: 1. The optimization of intermediate temperatures which optimize stage operation (a stage is assumed to have a constant cross section); 2. The optimum temperature difference available for best overall economic performance values. The results are viewed in the context of porous media concepts applied to rather low speeds of fluid flow in narrow passages. In this paper examples of fluid/solid constraints imposed in this non-classical low temperature area are presented

  11. An open-source library for the numerical modeling of mass-transfer in solid oxide fuel cells

    Science.gov (United States)

    Novaresio, Valerio; García-Camprubí, María; Izquierdo, Salvador; Asinari, Pietro; Fueyo, Norberto

    2012-01-01

    The generation of direct current electricity using solid oxide fuel cells (SOFCs) involves several interplaying transport phenomena. Their simulation is crucial for the design and optimization of reliable and competitive equipment, and for the eventual market deployment of this technology. An open-source library for the computational modeling of mass-transport phenomena in SOFCs is presented in this article. It includes several multicomponent mass-transport models ( i.e. Fickian, Stefan-Maxwell and Dusty Gas Model), which can be applied both within porous media and in porosity-free domains, and several diffusivity models for gases. The library has been developed for its use with OpenFOAM ®, a widespread open-source code for fluid and continuum mechanics. The library can be used to model any fluid flow configuration involving multicomponent transport phenomena and it is validated in this paper against the analytical solution of one-dimensional test cases. In addition, it is applied for the simulation of a real SOFC and further validated using experimental data. Program summaryProgram title: multiSpeciesTransportModels Catalogue identifier: AEKB_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKB_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public License No. of lines in distributed program, including test data, etc.: 18 140 No. of bytes in distributed program, including test data, etc.: 64 285 Distribution format: tar.gz Programming language:: C++ Computer: Any x86 (the instructions reported in the paper consider only the 64 bit case for the sake of simplicity) Operating system: Generic Linux (the instructions reported in the paper consider only the open-source Ubuntu distribution for the sake of simplicity) Classification: 12 External routines: OpenFOAM® (version 1.6-ext) ( http://www.extend-project.de) Nature of problem: This software provides a library of models for

  12. An Integrated Instrumentation System for Velocity, Concentration and Mass Flow Rate Measurement of Solid Particles Based on Electrostatic and Capacitance Sensors

    Directory of Open Access Journals (Sweden)

    Jian Li

    2015-12-01

    Full Text Available The online and continuous measurement of velocity, concentration and mass flow rate of pneumatically conveyed solid particles for the high-efficiency utilization of energy and raw materials has become increasingly significant. In this paper, an integrated instrumentation system for the velocity, concentration and mass flow rate measurement of dense phase pneumatically conveyed solid particles based on electrostatic and capacitance sensorsis developed. The electrostatic sensors are used for particle mean velocity measurement in combination with the cross-correlation technique, while the capacitance sensor with helical surface-plate electrodes, which has relatively homogeneous sensitivity distribution, is employed for the measurement of particle concentration and its capacitance is measured by an electrostatic-immune AC-based circuit. The solid mass flow rate can be further calculated from the measured velocity and concentration. The developed instrumentation system for velocity and concentration measurement is verified and calibrated on a pulley rig and through static experiments, respectively. Finally the system is evaluated with glass beads on a gravity-fed rig. The experimental results demonstrate that the system is capable of the accurate solid mass flow rate measurement, and the relative error is within −3%–8% for glass bead mass flow rates ranging from 0.13 kg/s to 0.9 kg/s.

  13. The impact of compaction and leachate recirculation on waste degradation in simulated landfills.

    Science.gov (United States)

    Ko, Jae Hac; Yang, Fan; Xu, Qiyong

    2016-07-01

    This study investigated the impact of compaction and leachate recirculation on anaerobic degradation of municipal solid waste (MSW) at different methane formation phases. Two stainless steel lysimeters, C1 and C2, were constructed by equipping a hydraulic cylinder to apply pressure load (42kPs) on the MSW. When MSW started to produce methane, C1 was compacted, but C2 was compacted when the methane production rate declined from the peak generation rate. Methane production of C1was inhibited by the compaction and resulted in producing a total of 106L methane (44L/kgVS). However, the compaction in C2 promoted MSW degradation resulting in producing a total of 298L methane (125L/kgVS). The concentrations of volatile fatty acids and chemical oxygen demand showed temporary increases, when pressure load was applied. It was considered that the increased substrate accessibility within MSW by compaction could cause either the inhibition or the enhancement of methane production, depending the tolerability of methanogens on the acidic inhibition. Leachate recirculation also gave positive effects on methane generation from wet waste in the decelerated methanogenic phase by increasing mass transfer and the concentrations of volatile fatty acids. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Quantitative Analysis of Bisphenol A Leached from Household Plastics by Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry (SPME-GC-MS)

    Science.gov (United States)

    Johnson, Bettie Obi; Burke, Fernanda M.; Harrison, Rebecca; Burdette, Samantha

    2012-01-01

    The measurement of trace levels of bisphenol A (BPA) leached out of household plastics using solid-phase microextraction (SPME) with gas chromatography-mass spectrometry (GC-MS) is reported here. BPA is an endocrine-disrupting compound used in the industrial manufacture of polycarbonate plastic bottles and epoxy resin can liners. This experiment…

  15. Derivatisation/solid-phase microextraction followed by gas chromatography-mass spectrometry for the analysis of phenoxy acid herbicides in aqueous samples

    DEFF Research Database (Denmark)

    Nilsson, Torben; Baglio, Daniela; Galdo-Miguez, Isabel

    1998-01-01

    Different combinations of derivatisation and solid-phase microextraction followed by gas chromatography-mass spectrometry were optimised and evaluated for the analysis of phenoxy acid herbicides in water. The most successful derivatisation approach was aqueous-phase derivatisation with benzyl...

  16. Determination of phenolic derivatives of antipyrine in plasma with solid-phase extraction and high-performance liquid chromatography-atmospheric-pressure chemical ionization mass spectrometry

    NARCIS (Netherlands)

    Coolen, S.A.J.; Ligor, T.; Lieshout, van H.P.M.; Huf, F.A.

    1999-01-01

    This manuscript describes a method to determine antipyrine and its phenolic derivatives in plasma by reversed-phase high-performance liquid chromatography–mass spectrometry (RP-HPLC–MS). The sample pretreatment consisted of a C18 solid-phase extraction (SPE), to remove the salts and proteins. The

  17. Data correlation in on-line solid-phase extraction-gas chromatography-atomic emission/mass spectrometric detection of unknown microcontaminants

    NARCIS (Netherlands)

    Hankemeier, Th.; Rozenbrand, J.; Abhadur, M.; Vreuls, J.J.; Brinkman, U.A.Th.

    1998-01-01

    A procedure is described for the (non-target) screening of hetero-atom-containing compounds in tap and waste water by correlating data obtained by gas chromatography (GC) using atomic emission (AED) and mass selective (MS) detection. Solid-phase extraction (SPE) was coupled on-line to both GC

  18. Dispersive solid phase extraction combined with ion-pair ultra high-performance liquid chromatography tandem mass spectrometry for quantification of nucleotides in Lactococcus lactis

    DEFF Research Database (Denmark)

    Magdenoska, Olivera; Martinussen, Jan; Thykær, Jette

    2013-01-01

    solid phase extraction with charcoal and subsequent analysis with ion-pair liquid chromatography coupled with electrospray ionization tandem mass spectrometry was established for quantification of intracellular pools of the 28 most important nucleotides. The method can handle extracts where cells leak...

  19. Isocratic Solid Phase Extraction-Liquid Chromatography (SPE-LC) Interfaced to High-Performance Tandem Mass Spectrometry for Rapid Protein Identification

    DEFF Research Database (Denmark)

    Hørning, Ole B; Kjeldsen, Frank; Theodorsen, Søren

    2008-01-01

    the isocratic solid phase extraction-liquid chromatography (SPE-LC) technology for rapid separation ( approximately 8 min) of simple peptide samples. We now extend these studies to demonstrate the potential of SPE-LC separation in combination with a hybrid linear ion trap-Orbitrap tandem mass spectrometer...

  20. Influence of liquid viscosity and surface tension on the gas-liquid mass transfer coefficient for solid foam packings in co-current two-phase flow

    NARCIS (Netherlands)

    Stemmet, C.P.; Bartelds, F.; Schaaf, van der J.; Kuster, B.F.M.; Schouten, J.C.

    2008-01-01

    The gas–liquid mass transfer coefficient and other hydrodynamic parameters such as liquid holdup and frictional pressure drop are presented for gas and liquid moving in co-current upflow and downflow through solid foam packings of 10 and of 40 pores per linear inch (ppi). The effect of increasing

  1. METHOD 544. DETERMINATION OF MICROCYSTINS AND NODULARIN IN DRINKING WATER BY SOLID PHASE EXTRACTION AND LIQUID CHROMATOGRAPHY/TANDEM MASS SPECTROMETRY (LC/MS/MS)

    Science.gov (United States)

    Method 544 is an accurate and precise analytical method to determine six microcystins (including MC-LR) and nodularin in drinking water using solid phase extraction and liquid chromatography tandem mass spectrometry (SPE-LC/MS/MS). The advantage of this SPE-LC/MS/MS is its sensi...

  2. Measurement of the abundance of stellar mass compact objects in the galactic halo by detecting micro-lenses in the Large Magellanic Cloud; Mesure de l'abondance des astres sombres de masse stellaire dans le halo galactique par la recherche de phenomenes de microlentilles vers les nuages de magellan

    Energy Technology Data Exchange (ETDEWEB)

    Lasserre, Th

    2000-05-09

    Many experimental and theoretical results lead to the conclusion that at least 80 percent of the mass of our Galaxy is dark. Part of this so-called dark matter could be in the form of stellar mass compact objects, called MACHOS; these could be detected using the gravitational microlensing effect. The first generation experiments EROS1 and MACHO have strongly constrained the galactic abundance of objects lighter than 0.01 solar mass to less than 10 percent of the total mass. In parallel, the observation by the MACHO group of massive candidates (half the Sun's mass), numerous enough to constitute 50 percent of galactic dark matter, was a further motivation for the EROS group to extend this search to stellar mass objects in a second phase, EROS2. The present work deals with the analysis of 25 million stellar light curves in the Large Magellanic Cloud, observed for three years in order to extract the rare microlensing candidates and to measure the galactic halo mass fraction in the form of compact objects. After recalling the motivations of this search and the theoretical context, I describe the EROS2 experiment. The observational strategy and the photometric reduction procedures needed to deal with the 1.2 To of data are then presented. A new method to detect micro-lenses is detailed, as well as a discussion of background light curves, poorly known. We do not find enough microlensing candidates to explain the galactic rotation curve; this confirms, and improve on previous EROS1 and EROS2 results. Combining all results from EROS allows to exclude that MACHOS with a mass between 10 e-7 and 10 solar mass are important constituents of the galactic halo. This statement agrees with recent results from the MACHO group, although our interpretations differ, namely on the topics of the location of the lenses, and of a possible contamination of the microlensing ample by background phenomena. (author)

  3. Rapid analysis of the skin irritant p-phenylenediamine (PPD) in henna products using atmospheric solids analysis probe mass spectrometry.

    Science.gov (United States)

    Chen, Weiyang; Nkosi, Thobile A N; Combrinck, Sandra; Viljoen, Alvaro M; Cartwright-Jones, Catherine

    2016-09-05

    Henna (Lawsonia inermis) is applied to stain keratin, present in hair, skin and fingernails, a red-orange or rust colour. Producers of temporary tattoos mix the aromatic amine compound, para-phenylenediamine (PPD) into natural henna to create 'black henna' that rapidly stains the skin black. However, PPD may cause severe delayed hypersensitivity reactions following skin contact. This study proposes a rapid direct-analysis method to detect and identify PPD using an atmospheric solids analysis probe (ASAP) coupled to a Q-ToF mass spectrometer (MS). Since laborious, multistep methods of analysis to determine PPD are undesirable, due to the instability of the compound in solution, a screening method involving no sample preparation steps was developed. Experiments were carried out to optimise the corona current, sample cone voltage, source temperature, and desolvation gas temperature to determine ideal ASAP-Q-ToF-MS analysing conditions. Eleven of the 109 henna samples, originating from various countries, tested positive for PPD when henna products were screened using ASAP-MS, without any form of sample preparation other than grinding. Ultra-performance liquid chromatography electrospray ionisation-mass spectrometry (UPLC-Q-ToF-MS) was subsequently used to confirm the results from ASAP and to determine the concentrations of PPD in henna products. The allergen was detected in the same eleven samples, with concentrations ranging from 0.05-4.21% (w/w). It can be concluded that the sensitivity of the ASAP-MS technique is sufficient (limit of detection=0.025% w/w) to allow screening of henna samples for the presence of PPD. This relatively new technique can be applied to commercial products without extraction, sample treatment or chromatographic separation. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Determination of Parabens by Injection-Port Derivatization Coupled With Gas-Chromatography-Mass Spectrometry and Matrix Solid Phase Dispersion

    Science.gov (United States)

    Djatmika, Rosalina; Ding, Wang-Hsien; Sulistyarti, Hermin

    2018-01-01

    A rapid determination of four parabens preservatives (methyl paraben, ethyl paraben, propyl paraben, and butyl paraben) in marketed seafood is presented. Analytes were extracted and purified using matrix solid-phase dispersion (MSPD) method, followed by Injection port acylation gas chromatography-mass spectrometry (GC-MS) with acetic anhydride reagent. In this method, acylation of parabens was performed by acetic anhydride at GC injection-port generating reduction of the time-consuming sample-processing steps, and the amount of toxic reagents and solvents. The parameters affecting this method such as injection port temperature, purge-off time and acylation (acetic anhydride) volume were studied. In addition, the MSPD influence factors (including the amount of dispersant and clean-up co-sorbent, as well as the volume of elution solvent) were also investigated. After MSPD method and Injection port acylation applied, good linearity of analytes was achieved. The limits of quantitation (LOQs) were 0.2 to 1.0 ng/g (dry weight). Compared with offline derivatization commonly performed, injection port acylation employs a rapid, simple, low-cost and environmental-friendly derivatization process. The optimized method has been successfully applied for the analysis of parabens in four kind of marketed seafood. Preliminary results showed that the total concentrations of four selected parabens ranged from 16.7 to 44.7 ng/g (dry weight).

  5. Comparison of the multicomponent mass transfer models for the prediction of the concentration overpotential for solid oxide fuel cell anodes

    Energy Technology Data Exchange (ETDEWEB)

    Vural, Yasemin; Ma, Lin; Ingham, Derek B.; Pourkashanian, Mohamed [Centre for Computational Fluid Dynamics, University of Leeds, Leeds (United Kingdom)

    2010-08-01

    In this study, multicomponent mass diffusion models, namely the Stefan-Maxwell model (SMM), the Dusty Gas model (DGM) and the Binary Friction model (BFM) have been compared in terms of their predictive capabilities of the concentration polarization of an anode supported solid oxide fuel cell (SOFC) anode. The results show that other than the pore diameter, current density and concentration of reactants, which have a high importance in concentration polarization predictions, the tortuosity (or porosity/tortuosity) term, has a substantial effect on the model predictions. Contrary to the previous discussions in the literature, for the fitted value of tortuosities, SMM and DGM predictions are similar, even for an average pore radius as small as 2.6e-07 and current density as high as 1.5 A cm{sup -2}. Also it is shown that the BFM predictions are similar to DGM for the case investigated in this study. Moreover, in this study, the effect of the pressure gradient term in the DGM and the BFM has been investigated by including and excluding this term from the model equations. It is shown that for the case investigated and model assumptions used in this study, the terms including the pressure coefficient have an insignificant effect on the predictions of both DGM and BFM and therefore they can be neglected. (author)

  6. Characterization of the volatile profiles of beer using headspace solid-phase microextraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Rossi, Serena; Sileoni, Valeria; Perretti, Giuseppe; Marconi, Ombretta

    2014-03-30

    The objective of this study was a multivariate characterization of the volatile profile of beers. Such a characterization is timely considering the increasing worldwide consumption of beer, the continuous growth of microbreweries and the importance of volatile compounds to beer flavour. A method employing solid-phase microextraction and gas chromatography-mass spectrometry (SPME-GC-MS) was optimized and then applied to a sample set of 36 industrial and craft beers of various styles and fermentation types. The volatile profiles of different beer styles is described, with particular attention paid to the volatile compounds characteristic of a spontaneously fermented lambic raspberry framboise beer. Furthermore, it was also possible to identify which specific volatile compounds are principally responsible for the differences in the volatile profiles of top- and bottom-fermented beers. Moreover, a volatile fingerprint of the craft top-fermented Italian beers was defined, as they show a very similar volatile profile. Finally, the volatile compounds that are characteristic of the bock-style beers are described. The SPME-GC-MS analytical method optimized in this study is suitable for characterizing the volatile fingerprint of different beers, especially on the basis of the kind of fermentation (top, bottom or spontaneous), the method of production and the style of the beer. © 2013 Society of Chemical Industry.

  7. Simultaneous detection of nine cyanotoxins in drinking water using dual solid-phase extraction and liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Yen, Hung-Kai; Lin, Tsair-Fuh; Liao, Pao-Chi

    2011-08-01

    A solid-phase extraction (SPE)-liquid chromatography (LC)-mass spectrometry (MS) method was developed to concentrate and detect nine cyanotoxins simultaneously, including six microcystins (MCs) congeners, nodularin (NOD), anatoxin-a (ATX) and cylindrospermopsin (CYN), in pure and natural waters. A dual cartridge SPE assembly was tested for the operating parameters of cyanotoxin extraction. A surrogate standard (SS), 1,9-diaminononane, was spiked in all the samples before the SPE extraction, and an internal standard (IS), 2,3,5-trimethylphenyl methyl carbamate, was spiked before LC/MS analysis. The method detection limit (MDL) was 2-100 ng/L for nine cyanotoxins in pure water and was increased by a factor of three to ten in a more complicated water matrix. The recoveries based on SS were between 83 and 104%, while those based on IS were 80-120%. The developed method was successfully employed in analyzing 33 water samples collected from eutrophic lakes, water treatment plants and distribution taps. MCs, NOD, and CYN were detected in the reservoir water, with concentrations as high as 36 μg/L. In addition, for the first time in Taiwan's tap water, CYN was detected at concentrations as high as 8.6 μg/L. Quality control data for the field samples shows that the analytical scheme developed is appropriate for monitoring cyanotoxins. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Direct solid phase microextraction combined with gas chromatography - Mass spectrometry for the determination of biogenic amines in wine.

    Science.gov (United States)

    Papageorgiou, Myrsini; Lambropoulou, Dimitra; Morrison, Calum; Namieśnik, Jacek; Płotka-Wasylka, Justyna

    2018-06-01

    A direct method based on immersion solid phase microextraction (DI-SPME) gas chromatography mass-spectrometry (GC-MS) was optimized and validated for the determination of 16 biogenic amines in Polish wines. In the analysis two internal standards were used: 1,7-diaminoheptane and bis-3-aminopropylamine. The method allows for simultaneous extraction and derivatization, providing a simple and fast mode of extraction and enrichment. Different parameters which affect the extraction procedure were studied and optimized including ionic strength (0-25%), fiber materials (PDMS/DVB, PDMS/DVD + OC, Polyacrylate, Carboxen/PDMS and DVB/CAR/PDMS) and timings of the extraction, derivatization and desorption processes. Validation studies confirmed the linearity, sensitivity, precision and accuracy of the method. The method was successfully applied to the analysis of 44 wine samples originating from several regions of Poland and 3 wine samples from other countries. Analysis showed that many of the samples contained all examined biogenic amines. The method, assessed using an Eco-Scale tool with satisfactory results, was found to be green in terms of hazardous chemicals and solvents usage, energy consumption and production of waste. Therefore the proposed method can be safely used in the wine industry for routine analysis of BAs in wine samples with a minimal detrimental impact on human health and the environment. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. DETERMINATION OF MUSHROOM TOXIN ALPHA-AMANITIN IN SERUM BY LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY AFTER SOLID-PHASE EXTRACTION

    Directory of Open Access Journals (Sweden)

    Maja Vujović

    2015-03-01

    Full Text Available Alpha-amanitin is a cyclic peptide which belongs to a large group of mushroom toxins known as amatoxins. Being responsible for the majority of fatal mushroom poisonings, they require rapid detection and excretion from the body fluids. In accordance with these requirements, a simple and an accurate method was developed for successful identification and quantification of alpha-amanitin in serum with electrospray liquid chromatography–mass spectrometry (LC-ESI-MS after collision-induced dissociation. The method conforms to the established International Conference on Harmonization Q2A/Q2B 1996 guidelines on the validation of analytical methods. Linearity, precision, extraction recovery and stability test on blank serum spiked with alpha-amanitin and stored in different conditions met the acceptance criteria. The obtained calibration curve was linear over the concentration range 5-100 ng/mL with a lower limit of quantification (LOQ of 5 ng/mL and limit of detection (LOD of 2.5 ng/mL. The mean intra- and inter-day precision and accuracy were 6.05% and less than ±15% of nominal values, respectively. The neutral solid phase extraction with copolymer hydrophilic–lipophilic balance cartridges was found optimal for sample preparation with the mean recovery of 91.94%. The proposed method demonstrated high sensitivity and selectivity which can be useful both for clinical and forensic toxicology analysis of alpha-amanitin at low concentrations.

  10. [Determination of flavor compounds in foxtail millet wine by gas chromatography-mass spectrometry coupled with headspace solid phase microextraction].

    Science.gov (United States)

    Liu, Jingke; Zhang, Aixia; Li, Shaohui; Zhao, Wei; Zhang, Yuzong; Xing, Guosheng

    2017-11-08

    To comprehensively understand flavor compounds and aroma characteristics of foxtail millet wine, extraction conditions were optimized with 85 μm polyacrylate (PA), 100 μm polydimethylsiloxane (PDMS), 75 μm carboxen (CAR)/PDMS and 50/30 μm divinylbenzene (DVB)/CAR/PDMS fibers. The flavor compounds in foxtail millet wine were investigated by gas chromatography-mass spectrometry (GC-MS) coupled with headspace solid phase microextraction (HS-SPME), and the odor characteristics and intensity were analyzed by odor active values (OAVs). The samples of 8 mL were placed in headspace vials with 1.5 g NaCl, then the headspace vials were heated at 60℃ for 40 min. Using HS-SPME with different fibers, a total of 55 flavor compounds were identified from the samples, including alcohols, esters, benzene derivatives, hydrocarbons, acids, aldehydes, ketones, terpenes, phenols and heterocycle compounds. The main flavor compounds were alcohols compounds. According to their OAVs, phenylethyl alcohol, styrene, 1-methyl-naphthalene, 2-methyl-naphthalene, benzaldehyde, benzeneacetaldehyde and 2-methoxy-phenol were established to be odor-active compounds. Phenylethyl alcohol and benzeneacetaldehyde were the most prominent odor-active compounds. PA and PDMS fibers had good extraction effect for polar and nonpolar compounds, respectively. CAR/PDMS and DVB/CAR/PDMS provided a similar compounds profile for moderate polar compounds. This research comprehensively determined flavor compounds of foxtail millet wine, and provided theoretical basis for product development and quality control.

  11. Determination of Volatile Compounds in Four Commercial Samples of Japanese Green Algae Using Solid Phase Microextraction Gas Chromatography Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Masayoshi Yamamoto

    2014-01-01

    Full Text Available Green algae are of great economic importance. Seaweed is consumed fresh or as seasoning in Japan. The commercial value is determined by quality, color, and flavor and is also strongly influenced by the production area. Our research, based on solid phase microextraction gas chromatography mass spectrometry (SPME-GC-MS, has revealed that volatile compounds differ intensely in the four varieties of commercial green algae. Accordingly, 41 major volatile compounds were identified. Heptadecene was the most abundant compound from Okayama (Ulva prolifera, Tokushima (Ulva prolifera, and Ehime prefecture (Ulva linza. Apocarotenoids, such as ionones, and their derivatives were prominent volatiles in algae from Okayama (Ulva prolifera and Tokushima prefecture (Ulva prolifera. Volatile, short chained apocarotenoids are among the most potent flavor components and contribute to the flavor of fresh, processed algae, and algae-based products. Benzaldehyde was predominant in seaweed from Shizuoka prefecture (Monostroma nitidum. Multivariant statistical analysis (PCA enabled simple discrimination of the samples based on their volatile profiles. This work shows the potential of SPME-GC-MS coupled with multivariant analysis to discriminate between samples of different geographical and botanical origins and form the basis for development of authentication methods of green algae products, including seasonings.

  12. Determination of volatile compounds in four commercial samples of Japanese green algae using solid phase microextraction gas chromatography mass spectrometry.

    Science.gov (United States)

    Yamamoto, Masayoshi; Baldermann, Susanne; Yoshikawa, Keisuke; Fujita, Akira; Mase, Nobuyuki; Watanabe, Naoharu

    2014-01-01

    Green algae are of great economic importance. Seaweed is consumed fresh or as seasoning in Japan. The commercial value is determined by quality, color, and flavor and is also strongly influenced by the production area. Our research, based on solid phase microextraction gas chromatography mass spectrometry (SPME-GC-MS), has revealed that volatile compounds differ intensely in the four varieties of commercial green algae. Accordingly, 41 major volatile compounds were identified. Heptadecene was the most abundant compound from Okayama (Ulva prolifera), Tokushima (Ulva prolifera), and Ehime prefecture (Ulva linza). Apocarotenoids, such as ionones, and their derivatives were prominent volatiles in algae from Okayama (Ulva prolifera) and Tokushima prefecture (Ulva prolifera). Volatile, short chained apocarotenoids are among the most potent flavor components and contribute to the flavor of fresh, processed algae, and algae-based products. Benzaldehyde was predominant in seaweed from Shizuoka prefecture (Monostroma nitidum). Multivariant statistical analysis (PCA) enabled simple discrimination of the samples based on their volatile profiles. This work shows the potential of SPME-GC-MS coupled with multivariant analysis to discriminate between samples of different geographical and botanical origins and form the basis for development of authentication methods of green algae products, including seasonings.

  13. Development of near-field laser ablation inductively coupled plasma mass spectrometry for sub-micrometric analysis of solid samples

    International Nuclear Information System (INIS)

    Jabbour, Chirelle

    2016-01-01

    A near field laser ablation method was developed for chemical analysis of solid samples at sub-micrometric scale. This analytical technique combines a nanosecond laser Nd:YAG, an atomic Force Microscope (AFM), and an inductively coupled plasma mass spectrometer (ICPMS). In order to improve the spatial resolution of the laser ablation process, the near-field enhancement effect was applied by illuminating, by the laser beam, the apex of the AFM conductive sharp tip maintained at a few nanometers (5 to 30 nm) above the sample surface. The interaction between the illuminated tip and the sample surface enhances locally the incident laser energy and leads to the ablation process. By applying this technique to conducting gold and tantalum samples, and semiconducting silicon sample, a lateral resolution of 100 nm and depths of a few nanometers were demonstrated. Two home-made numerical codes have enabled the study of two phenomena occurring around the tip: the enhancement of the laser electrical field by tip effect, and the induced laser heating at the sample surface. The influence of the main operating parameters on these two phenomena, amplification and heating, was studied. an experimental multi-parametric study was carried out in order to understand the effect of different experimental parameters (laser fluence, laser wavelength, number of laser pulses, tip-to-sample distance, sample and tip nature) on the near-field laser ablation efficiency, crater dimensions and amount of ablated material. (author) [fr

  14. Determination of organoarsenicals in the environment by solid-phase microextraction-gas chromatography-mass spectrometry.

    Energy Technology Data Exchange (ETDEWEB)

    Szostek, B.; Aldstadt, J. H.; Environmental Research

    1998-05-22

    The development of a method for the analysis of organoarsenic compounds that combines dithiol derivatization with solid-phase microextraction (SPME) sample preparation and gas chromatography-mass spectrometry (GC-MS) is described. Optimization focused on a SPME-GC-MS procedure for determination of 2-chlorovinylarsonous acid (CVAA), the primary decomposition product of the chemical warfare agent known as Lewisite. Two other organoarsenic compounds of environmental interest, dimethylarsinic acid and phenylarsonic acid, were also studied. A series of dithiol compounds was examined for derivatization of the arsenicals, and the best results were obtained either with 1,3-propanedithiol or 1,2-ethanedithiol. The derivatization procedure, fiber type, and extraction time were optimized. For CVAA, calibration curves were linear over three orders of magnitude and limits-of-detection were <6x10{sup -9} M in solution, the latter a more than 400x improvement compared to conventional solvent extraction GC-MS methods. A precision of <10% R.S.D. was typical for the SPME-GC-MS procedure. The method was applied to a series of water samples and soil/sediment extracts, as well as to aged soil samples that had been contaminated with Lewisite.

  15. Solid-phase microextraction for gas chromatographic/mass spectrometric analysis of dimethoate in human biological samples.

    Science.gov (United States)

    Gallardo, E; Barroso, M; Margalho, C; Cruz, A; Vieira, D N; López-Rivadulla, M

    2006-01-01

    A new, simple and rapid procedure for the determination of dimethoate in urine and blood samples was developed using direct immersion solid-phase microextraction and gas chromatography/mass spectrometry. This technique required only 0.1 mL of sample, and ethion was used as internal standard. Two types of coated fibre were compared (100 microm polydimethylsiloxane, and 65 microm Carbowax/divinylbenzene). Other parameters, such as extraction temperature, adsorption and desorption time, salt addition, agitation and pH, were optimized to enhance the sensitivity of the method. Limits of detection (LODs) and quantitation (LOQs) were 50 and 100 ng/mL for urine and 200 and 500 ng/mL for blood, respectively. The method was found to be linear between the LOQ and 40 microg/mL for urine, and between the LOQ and 50 microg/mL for blood, with correlation coefficients ranging from 0.9923-0.9996. Precision (intra- and interday) and accuracy were in conformity with the criteria normally accepted in bioanalytical method validation. The mean absolute recoveries of dimethoate were 1.24 and 0.50% for urine and blood, respectively. Because of its simplicity and the fact that small volumes of sample are used, the described method can be successfully used in the diagnosis of poisoning by this pesticide, namely in those situations where the sample volume is limited, as frequently occurs in forensic toxicology. Copyright 2006 John Wiley & Sons, Ltd.

  16. Direct Analysis of Amphetamine Stimulants in a Whole Urine Sample by Atmospheric Solids Analysis Probe Tandem Mass Spectrometry

    Science.gov (United States)

    Crevelin, Eduardo J.; Salami, Fernanda H.; Alves, Marcela N. R.; De Martinis, Bruno S.; Crotti, Antônio E. M.; Moraes, Luiz A. B.

    2016-05-01

    Amphetamine-type stimulants (ATS) are among illicit stimulant drugs that are most often used worldwide. A major challenge is to develop a fast and efficient methodology involving minimal sample preparation to analyze ATS in biological fluids. In this study, a urine pool solution containing amphetamine, methamphetamine, ephedrine, sibutramine, and fenfluramine at concentrations ranging from 0.5 pg/mL to 100 ng/mL was prepared and analyzed by atmospheric solids analysis probe tandem mass spectrometry (ASAP-MS/MS) and multiple reaction monitoring (MRM). A urine sample and saliva collected from a volunteer contributor (V1) were also analyzed. The limit of detection of the tested compounds ranged between 0.002 and 0.4 ng/mL in urine samples; the signal-to-noise ratio was 5. These results demonstrated that the ASAP-MS/MS methodology is applicable for the fast detection of ATS in urine samples with great sensitivity and specificity, without the need for cleanup, preconcentration, or chromatographic separation. Thus ASAP-MS/MS could potentially be used in clinical and forensic toxicology applications.

  17. Prediction by Artificial Neural Networks (ANN of the diffusivity, mass, moisture, volume and solids on osmotically dehydrated yacon (Smallantus sonchifolius

    Directory of Open Access Journals (Sweden)

    Julio Rojas Naccha

    2012-09-01

    Full Text Available The predictive ability of Artificial Neural Network (ANN on the effect of the concentration (30, 40, 50 y 60 % w/w and temperature (30, 40 y 50°C of fructooligosaccharides solution, in the mass, moisture, volume and solids of osmodehydrated yacon cubes, and in the coefficients of the water means effective diffusivity with and without shrinkage was evaluated. The Feedforward type ANN with the Backpropagation training algorithms and the Levenberg-Marquardt weight adjustment was applied, using the following topology: 10-5 goal error, 0.01 learning rate, 0.5 moment coefficient, 2 input neurons, 6 output neurons, one hidden layer with 18 neurons, 15 training stages and logsig-pureline transfer functions. The overall average error achieved by the ANN was 3.44% and correlation coefficients were bigger than 0.9. No significant differences were found between the experimental values and the predicted values achieved by the ANN and with the predicted values achieved by a statistical model of second-order polynomial regression (p > 0.95.

  18. Determination of amphetamine-type stimulants in oral fluid by solid-phase microextraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Souza, Daniele Z; Boehl, Paula O; Comiran, Eloisa; Mariotti, Kristiane C; Pechansky, Flavio; Duarte, Paulina C A V; De Boni, Raquel; Froehlich, Pedro E; Limberger, Renata P

    2011-06-24

    A method for the simultaneous identification and quantification of amphetamine (AMP), methamphetamine (MET), fenproporex (FEN), diethylpropion (DIE) and methylphenidate (MPH) in oral fluid collected with Quantisal™ device has been developed and validated. Thereunto, in-matrix propylchloroformate derivatization followed by direct immersion solid-phase microextraction and gas chromatography-mass spectrometry were employed. Deuterium labeled AMP was used as internal standard for all the stimulants and analysis was performed using the selected ion monitoring mode. The detector response was linear for the studied drugs in the concentration range of 2-256 ng mL(-1) (neat oral fluid), except for FEN, whereas the linear range was 4-256 ng mL(-1). The detection limits were 0.5 ng mL(-1) (MET), 1 ng mL(-1) (MPH) and 2 ng mL(-1) (DIE, AMP, FEN), respectively. Accuracy of quality control samples remained within 98.2-111.9% of the target concentrations, while precision has not exceeded 15% of the relative standard deviation. Recoveries with Quantisal™ device ranged from 77.2% to 112.1%. Also, the goodness-of-fit concerning the ordinary least squares model in the statistical inference of data has been tested through residual plotting and ANOVA. The validated method can be easily automated and then used for screening and confirmation of amphetamine-type stimulants in drivers' oral fluid. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Simultaneous analysis of amphetamine-type stimulants in plasma by solid-phase microextraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Mariotti, Kristiane de Cássia; Schuh, Roselena S; Ferranti, Priscila; Ortiz, Rafael S; Souza, Daniele Z; Pechansky, Flavio; Froehlich, Pedro E; Limberger, Renata P

    2014-09-01

    Brazil is considered one of the countries with the highest number of amphetamine-type stimulant (ATS) users worldwide, mainly diethylpropion (DIE) and fenproporex (FEN). The use of ATS is mostly linked to diverted prescription stimulants and this misuse is widely associated with (ab)use by drivers. A validated method was developed for the simultaneous analysis of amphetamine (AMP), DIE and FEN in plasma samples employing direct immersion-solid-phase microextraction, and gas chromatographic/mass spectrometric analysis. Trichloroacetic acid 10% was used for plasma deproteinization. In situ derivatization with propylchloroformate was employed. The linear range of the method covered from 5.0 to 100 ng/mL. The detection limits were 1.0 (AMP), 1.5 (DIE) and 2.0 ng/mL (FEN). The accuracy assessment of the control samples was within 85.58-108.33% of the target plasma concentrations. Recoveries ranged from 46.35 to 84.46% and precision was <15% of the value of relative standard deviation. This method is appropriate for screening and confirmation in plasma forensic toxicology analyses of these basic drugs. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Rapid Determination of Clenbuterol in Pork by Direct Immersion Solid-Phase Microextraction Coupled with Gas Chromatography-Mass Spectrometry.

    Science.gov (United States)

    Ye, Diru; Wu, Susu; Xu, Jianqiao; Jiang, Ruifen; Zhu, Fang; Ouyang, Gangfeng

    2016-02-01

    Direct immersion solid-phase microextraction (DI-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was developed for rapid analysis of clenbuterol in pork for the first time. In this work, a low-cost homemade 44 µm polydimethylsiloxane (PDMS) SPME fiber was employed to extract clenbuterol in pork. After extraction, derivatization was performed by suspending the fiber in the headspace of the 2 mL sample vial saturated with a vapor of 100 µL hexamethyldisilazane. Lastly, the fiber was directly introduced to GC-MS for analysis. All parameters that influenced absorption (extraction time), derivatization (derivatization reagent, time and temperature) and desorption (desorption time) were optimized. Under optimized conditions, the method offered a wide linear range (10-1000 ng g(-1)) and a low detection limit (3.6 ng g(-1)). Finally, the method was successfully applied in the analysis of pork from the market, and recoveries of the method for spiked pork were 97.4-105.7%. Compared with the traditional solvent extraction method, the proposed method was much cheaper and fast. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Magnetic solid phase extraction and static headspace gas chromatography-mass spectrometry method for the analysis of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Cai, Ying; Yan, Zhihong; Wang, Lijia; NguyenVan, Manh; Cai, Qingyun

    2016-01-15

    A magnetic solid phase extraction (MSPE) protocol combining a static headspace gas chromatography coupled to mass spectrometry (HS-GC-MS) method has been developed for extraction, and determination of 16 polycyclic aromatic hydrocarbons (PAHs) in drinking water samples. Magnetic nanoparticles (MNPs) were coated with 3-aminopropyltriethoxysilane and modified by cholesterol chloroformate. Transmission electron microscope, vibrating sample magnetometer, Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy were used to characterize the cholesterol-functionalized sorbents, and the main parameters affecting the extraction as well as HS sampling, such as sorbent amount, extraction time, oven temperature and equilibration time have been investigated and established. Combination with HS sampling, the MSPE procedure was simple, fast and environmentally friendly, without need of any organic solvent. Method validation proved the feasibility of the developed sorbents for the quantitation of the investigated analytes at trace levels obtaining the limit of detection (S/N=3) ranging from 0.20 to 7.8 ng/L. Good values for intra and inter-day precision were obtained (RSDs ≤ 9.9%). The proposed method was successfully applied to drinking water samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Compaction of plant biomass for solid biofuels production Compactação de biomassa vegetal visando à produção de biocombustíveis sólidos

    Directory of Open Access Journals (Sweden)

    Thiago de Paula Protásio

    2011-12-01

    Full Text Available

    This research aimed to evaluate briquettes made from coffee husk, eucalyptus sawdust and maize harvesting residues, and the influence of post compaction interval on some properties of the briquettes. After oven drying of the biomass, the briquettes were produced in a laboratory briquetting machine at 120 ºC and 15 MPa. Bulk density and heating value of the fresh biomass were analyzed. After compaction, influence of time on moisture content, volumetric expansion an bulk density of the briquettes was analyzed. From the results, it was observed that milled coffee husk had the highest mean value of bulk density. There was no statistical difference for higher heating value among the biomass analyzed. The effect of pos compaction interval was significant on moisture content based on dry mass and bulk density for all briquettes produced. The briquettes produced from maize harvesting residues had high volumetric expansion. Considering tensile strength by diametric compression, coffee husk briquettes were more resistant. The results highlight the potential of energetic use of briquettes obtained by compaction of coffee husks.

    doi: 10.4336/2011.pfb.31.68.273

    O objetivo do presente trabalho foi avaliar briquetes produzidos a partir de casca de café, serragem de eucalipto e resíduos da colheita do milho, e a influência do tempo após a compactação em algumas propriedades dos briquetes. Após a biomassa ser previamente seca em estufa, os briquetes foram produzidos em uma briquetadeira laboratorial, à temperatura de 120±5ºC e pressão de 15 MPa. Determinaram-se a densidade a granel e o poder calorífico das biomassas in natura. Após a compactação, avaliou-se a influência do tempo sobre a umidade, a expansão volumétrica e a densidade aparente dos briquetes. A partir dos resultados obtidos, pode-se observar que a casca de café moída apresentou o maior valor médio para densidade a granel. Estatisticamente, as biomassas analisadas

  3. Probing the Conformation of an IgG1 Monoclonal Antibody in Lyophilized Solids Using Solid-State Hydrogen-Deuterium Exchange with Mass Spectrometric Analysis (ssHDX-MS).

    Science.gov (United States)

    Moussa, Ehab M; Singh, Satish K; Kimmel, Michael; Nema, Sandeep; Topp, Elizabeth M

    2018-02-05

    Therapeutic proteins are often formulated as lyophilized products to improve their stability and prolong shelf life. The stability of proteins in the solid-state has been correlated with preservation of native higher order structure and/or molecular mobility in the solid matrix, with varying success. In the studies reported here, we used solid-state hydrogen-deuterium exchange with mass spectrometric analysis (ssHDX-MS) to study the conformation of an IgG1 monoclonal antibody (mAb) in lyophilized solids and related the extent of ssHDX to aggregation during storage in the solid phase. The results demonstrate that the extent of ssHDX correlated better with aggregation rate during storage than did solid-state Fourier-transform infrared (ssFTIR) spectroscopic measurements. Interestingly, adding histidine to sucrose at different formulation pH conditions decreased aggregation of the mAb, an effect that did not correlate with structural or conformational changes as measured by ssFTIR or ssHDX-MS. Moreover, peptide-level ssHDX-MS analysis in four selected formulations demonstrated global changes across the structure of the mAb when lyophilized with sucrose, trehalose, or mannitol, whereas site-specific changes were observed when lyophilized with histidine as the sole excipient.

  4. Chapter 3. Determination of semivolatile organic compounds and polycyclic aromatic hydrocarbons in solids by gas chromatography/mass spectrometry

    Science.gov (United States)

    Zaugg, Steven D.; Burkhardt, Mark R.; Burbank, Teresa L.; Olson, Mary C.; Iverson, Jana L.; Schroeder, Michael P.

    2006-01-01

    A method for the determination of 38 polycyclic aromatic hydrocarbons (PAHs) and semivolatile organic compounds in solid samples is described. Samples are extracted using a pressurized solvent extraction system. The compounds of interest are extracted from the solid sample twice at 13,800 kilopascals; first at 120 degrees Celsius using a water/isopropyl alcohol mixture (50:50, volume-to-volume ratio), and then the sample is extracted at 200 degrees Celsius using a water/isopropyl alcohol mixture (80:20, volume-to-volume ratio). The compounds are isolated using disposable solid-phase extraction (SPE) cartridges containing divinylbenzene-vinylpyrrolidone copolymer resin. The cartridges are dried with nitrogen gas, and then sorbed compounds are eluted from the SPE material using a dichloromethane/diethyl ether mixture (80:20, volume-to-volume ratio) and passed through a sodium sulfate/Florisil SPE cartridge to remove residual water and to further clean up the extract. The concentrated extract is solvent exchanged into ethyl acetate and the solvent volume reduced to 0.5 milliliter. Internal standard compounds are added prior to analysis by capillary-column gas chromatography/mass spectrometry. Comparisons of PAH data for 28 sediment samples extracted by Soxhlet and the accelerated solvent extraction (ASE) method described in this report produced similar results. Extraction of PAH compounds from standard reference material using this method also compared favorably with Soxhlet extraction. The recoveries of PAHs less than molecular weight 202 (pyrene or fluoranthene) are higher by up to 20 percent using this ASE method, whereas the recoveries of PAHs greater than or equal to molecular weight 202 are equivalent. This ASE method of sample extraction of solids has advantages over conventional Soxhlet extraction by increasing automation of the extraction process, reducing extraction time, and using less solvent. Extract cleanup also is greatly simplified because SPE replaces

  5. Mass absorption and mass energy transfer coefficients for 0.4-10 MeV gamma rays in elemental solids and gases

    Energy Technology Data Exchange (ETDEWEB)

    Gurler, O. [Physics Department, Faculty of Arts and Sciences, Uludag University, Gorukle Campus, 16059 Bursa (Turkey)], E-mail: ogurler@uludag.edu.tr; Oz, H. [Physics Department, Faculty of Arts and Sciences, Uludag University, Gorukle Campus, 16059 Bursa (Turkey); Yalcin, S. [Education Faculty, Kastamonu University, 37200 Kastamonu (Turkey); Gundogdu, O. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); NCCPM, Medical Physics, Royal Surrey County Hospital, GU2 7XX (United Kingdom)

    2009-01-15

    The mass energy absorption, the mass energy transfer and mass absorption coefficients have been widely used for problems and applications involving dose calculations. Direct measurements of the coefficients are difficult, and theoretical computations are usually employed. In this paper, analytical equations are presented for determining the mass energy transfer and mass absorption coefficients for gamma rays with an incident energy range between 0.4 and 10 MeV in nitrogen, silicon, carbon, copper and sodium iodide. The mass absorption and mass energy transfer coefficients for gamma rays were calculated, and the results obtained were compared with the values reported in the literature.

  6. Mass absorption and mass energy transfer coefficients for 0.4-10 MeV gamma rays in elemental solids and gases

    International Nuclear Information System (INIS)

    Gurler, O.; Oz, H.; Yalcin, S.; Gundogdu, O.

    2009-01-01

    The mass energy absorption, the mass energy transfer and mass absorption coefficients have been widely used for problems and applications involving dose calculations. Direct measurements of the coefficients are difficult, and theoretical computations are usually employed. In this paper, analytical equations are presented for determining the mass energy transfer and mass absorption coefficients for gamma rays with an incident energy range between 0.4 and 10 MeV in nitrogen, silicon, carbon, copper and sodium iodide. The mass absorption and mass energy transfer coefficients for gamma rays were calculated, and the results obtained were compared with the values reported in the literature

  7. Simultaneous determination of phenolic compounds in Equisetum palustre L. by ultra high performance liquid chromatography with tandem mass spectrometry combined with matrix solid-phase dispersion extraction.

    Science.gov (United States)

    Wei, Zuofu; Pan, Youzhi; Li, Lu; Huang, Yuyang; Qi, Xiaolin; Luo, Meng; Zu, Yuangang; Fu, Yujie

    2014-11-01

    A method based on matrix solid-phase dispersion extraction followed by ultra high performance liquid chromatography with tandem mass spectrometry is presented for the extraction and determination of phenolic compounds in Equisetum palustre. This method combines the high efficiency of matrix solid-phase dispersion extraction and the rapidity, sensitivity, and accuracy of ultra high performance liquid chromatography with tandem mass spectrometry. The influential parameters of the matrix solid-phase dispersion extraction were investigated and optimized. The optimized conditions were as follows: silica gel was selected as dispersing sorbent, the ratio of silica gel to sample was selected to be 2:1 (400/200 mg), and 8 mL of 80% methanol was used as elution solvent. Furthermore, a fast and sensitive ultra high performance liquid chromatography with tandem mass spectrometry method was developed for the determination of nine phenolic compounds in E. palustre. This method was carried out within <6 min, and exhibited satisfactory linearity, precision, and recovery. Compared with ultrasound-assisted extraction, the proposed matrix solid-phase dispersion procedure possessed higher extraction efficiency, and was more convenient and time saving with reduced requirements on sample and solvent amounts. All these results suggest that the developed method represents an excellent alternative for the extraction and determination of active components in plant matrices. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Mass loss and nutrient concentrations of buried wood as a function of organic matter removal, soil compaction, and vegetation control in a regenerating oak-pine forest

    Science.gov (United States)

    Felix Ponder; John M. Kabrick; Mary Beth Adams; Deborah S. Page-Dumroese; Marty F. Jurgensen

    2017-01-01

    Mass loss and nutrient concentrations of northern red oak (Quercus rubra) and white oak (Q. alba) wood stakes were measured 30 months after their burial in the upper 10 cm of soil in a regenerating forest after harvesting and soil disturbance. Disturbance treatments were two levels of organic matter (OM) removal (only...

  9. Tracer diffusion in compacted, water-saturated bentonite

    International Nuclear Information System (INIS)

    Bourg, Ian C.; Sposito, Garrison; Bourg, Alain C.M.

    2005-01-01

    Compacted Na-bentonite clay barriers, widely used in the isolation of solid-waste landfills and other contaminated sites, have been proposed for a similar use in the disposal of high-level radioactive waste. Molecular diffusion through the pore space in these barriers plays a key role in their performance, thus motivating recent measurements of the apparent diffusion coefficient tensor of water tracers in compacted, water-saturated Na-bentonites. In the present study, we introduce a conceptual model in which the pore space of water-saturated bentonite is divided into 'macropore' and 'interlayer nanopore' compartments. With this model we determine quantitatively the relative contributions of pore-network geometry (expressed as a geometric factor) and of the diffusive behavior of water molecules near montmorillonite basal surfaces(expressed as a contrastivity factor) to the apparent diffusion coefficient tensor. Our model predicts, in agreement with experiment, that the mean principal value of the apparent diffusion coefficient tensor follows a single relationship when plotted against the partial montmorillonite dry density (mass of montmorillonite per combined volume of montmorillonite and pore space). Using a single fitted parameter, the mean principal geometric factor, our model successfully describes this relationship for a broad range of bentonite-water system, from dilute gel to highly-compacted bentonite with 80 percent of its pore water in interlayer nanopores

  10. Stable quasi-solid-state dye-sensitized solar cell using ionic gel electrolyte with low molecular mass organogelator

    International Nuclear Information System (INIS)

    Tao, Li; Huo, Zhipeng; Dai, Songyuan; Zhu, Jun; Zhang, Changneng; Pan, Xu; Huang, Yang; Yang, Shangfeng; Zhang, Bing; Yao, Jianxi

    2015-01-01

    Long-term stability is essential for the application and commercialization of dye-sensitized solar cells (DSCs). A quasi-solid-state DSC (QS-DSC) with excellent long-term stability is fabricated using ionic gel electrolyte (IGE) with N,N′-methylenebisdodecanamide as low molecular mass organogelator (LMOG). The gel to solution transition temperature (T gel ) of this IGE is 127 °C, well above the working temperature of the device, which contributes to the thermal properties of the IGE and the device. The electrochemical properties of the IGE and the kinetic processes of electron transport and recombination of the QS-DSC are investigated by means of electrochemical impedance spectroscopy (EIS) and controlled intensity modulated photocurrent/photovoltage spectroscopy (IMPS/IMVS). Due to the obstructed diffusion of redox species caused by the network of IGE, the electron recombination at the TiO 2 photoelectrode/electrolyte interface in the QS-DSC is accelerated. More importantly, compared with the ionic liquid electrolyte (ILE) based DSC, the QS-DSC based on the IGE exhibits excellent thermal and light-soaking stabilities during the accelerated aging tests for 1000 h. Especially, there is almost no degradation in the short-circuit current density (J sc ) in the IGE based QS-DSC, while the J sc of the ILE based DSC decreased to 85–94% of their initial values. - Highlights: • A novel IGE with high T gel is obtained by using a diamide derivative as LMOG. • The IGE based QS-DSC is very stable during the accelerated aging tests. • The influences of gelation on the electron kinetic processes are investigated

  11. Combined solid-phase extraction and gas chromatography-mass spectrometry used for determination of chloropropanols in water.

    Science.gov (United States)

    González, Paula; Racamonde, Inés; Carro, Antonia M; Lorenzo, Rosa A

    2011-10-01

    A sensitive and rapid derivatization method for the simultaneous determination of 1,3-dichloro-2-propanol (1,3-DCP) and 3-chloropropane-1,2-diol (3-MCPD) in water samples has been developed. The aim was to research the optimal conditions of the derivatization process for two selected reagents. A central composite design was used to determine the influence of derivatization time, derivatization temperature and reagent volume. A global desirability function was applied for multi-response optimization. The analysis was performed by gas chromatography-mass spectrometry. During the optimization of the extraction procedure, four different types of solid-phase extraction (SPE) columns were tested. It was demonstrated that the Oasis HLB cartridge produced the best recoveries of the target analytes. The pH value and the salinity were investigated using a Doehlert design. The best results for the SPE of both analytes were obtained with 1.5 g of NaCl and pH 6. The proposed method provides high sensitivity, good linearity (R(2)≥0.999) and repeatability (relative standard deviations % between 2.9 and 3.4%). Limits of detection and quantification were in the range of 1.4-11.2 ng/mL and 4.8-34.5 ng/mL, respectively. Recoveries obtained for water samples were ca. 100% for 1,3-DCP and 3-MCPD. The method has been successfully applied to the analysis of different samples including commercially bottled water, an influent and effluent sewage. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Stable quasi-solid-state dye-sensitized solar cell using ionic gel electrolyte with low molecular mass organogelator

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Li [Key Laboratory of Novel Thin Film Solar Cells, Division of Solar Energy Materials and Engineering, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Huo, Zhipeng, E-mail: zhipenghuo@163.com [Key Laboratory of Novel Thin Film Solar Cells, Division of Solar Energy Materials and Engineering, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Dai, Songyuan, E-mail: sydai@ncepu.edu.cn [Key Laboratory of Novel Thin Film Solar Cells, Division of Solar Energy Materials and Engineering, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Beijing Key Lab of Novel Thin Film Solar Cells, North China Electric Power University, Beijing 102206 (China); Zhu, Jun; Zhang, Changneng; Pan, Xu; Huang, Yang [Key Laboratory of Novel Thin Film Solar Cells, Division of Solar Energy Materials and Engineering, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Yang, Shangfeng [Hefei National Laboratory for Physical Sciences at Microscale, Department of Materials Science and Engineering, University of Science and Technology of China (USTC), Hefei 230026 (China); Zhang, Bing; Yao, Jianxi [Beijing Key Lab of Novel Thin Film Solar Cells, North China Electric Power University, Beijing 102206 (China)

    2015-02-15

    Long-term stability is essential for the application and commercialization of dye-sensitized solar cells (DSCs). A quasi-solid-state DSC (QS-DSC) with excellent long-term stability is fabricated using ionic gel electrolyte (IGE) with N,N′-methylenebisdodecanamide as low molecular mass organogelator (LMOG). The gel to solution transition temperature (T{sub gel}) of this IGE is 127 °C, well above the working temperature of the device, which contributes to the thermal properties of the IGE and the device. The electrochemical properties of the IGE and the kinetic processes of electron transport and recombination of the QS-DSC are investigated by means of electrochemical impedance spectroscopy (EIS) and controlled intensity modulated photocurrent/photovoltage spectroscopy (IMPS/IMVS). Due to the obstructed diffusion of redox species caused by the network of IGE, the electron recombination at the TiO{sub 2} photoelectrode/electrolyte interface in the QS-DSC is accelerated. More importantly, compared with the ionic liquid electrolyte (ILE) based DSC, the QS-DSC based on the IGE exhibits excellent thermal and light-soaking stabilities during the accelerated aging tests for 1000 h. Especially, there is almost no degradation in the short-circuit current density (J{sub sc}) in the IGE based QS-DSC, while the J{sub sc} of the ILE based DSC decreased to 85–94% of their initial values. - Highlights: • A novel IGE with high T{sub gel} is obtained by using a diamide derivative as LMOG. • The IGE based QS-DSC is very stable during the accelerated aging tests. • The influences of gelation on the electron kinetic processes are investigated.

  13. Compact sources for eyesafe illumination

    Science.gov (United States)

    Baranova, Nadia; Pu, Rui; Stebbins, Kenneth; Bystryak, Ilya; Rayno, Michael; Ezzo, Kevin; DePriest, Christopher

    2018-02-01

    Q-peak has demonstrated a compact, pulsed eyesafe laser architecture operating with >10 mJ pulse energies at repetition rates as high as 160 Hz. The design leverages an end-pumped solid-state laser geometry to produce adequate eyesafe beam quality (M2˜4), while also providing a path toward higher-density laser architectures for pulsed eyesafe applications. The baseline discussed in this paper has shown a unique capability for high-pulse repetition rates in a compact package, and offers additional potential for power scaling based on birefringence compensation. The laser consists of an actively Q-switched oscillator cavity producing pulse widths designed to fit within a volume of 3760 cm3. We will discuss details of the optical system design, modeled thermal effects and stress-induced birefringence, as well as experimental advantages of the end-pumped laser geometry, along with proposed paths to higher eyesafe pulse energies.

  14. A compact fast data acquisition and data analysis system for time of flight mass spectrometry. Time and S.I. intensity measurements with a new multistop TDC

    International Nuclear Information System (INIS)

    Della-Negra, S.; Le Beyec, Y.

    1987-01-01

    A data acquisition and processing system for time of flight mass spectrometry, based on a PC-AT computer with an additional memory card was developed, and analysis software was written. About 100,000 counts/sec can be analyzed and stored in the memory. In the coincidence mode, 1000 start events with 10 stop events (per sec) on one time digital converter allow 10 spectra to be recorded. Examples of printouts are shown

  15. Halogen speciation in volcanic plumes - Development of compact denuder sampling techniques with in-situ derivatization followed by gas chromatography-mass spectrometry and their application at Mt. Etna, Mt. Nyiragongo and Mt. Nyamulagira in 2015.

    Science.gov (United States)

    Rüdiger, Julian; Bobrowski, Nicole; Hoffmann, Thorsten

    2016-04-01

    products. The diffusion denuder technique allows sampling of gaseous compounds exclusively without collecting particulate matter. Solvent elution of the derivatized analytes and subsequent analysis with gas chromatography-mass spectrometry gives a limit of detection below 1 ng of bromine. The method was applied in 2015 on volcanic gas plumes at Mt. Etna (Italy), Mt. Nyiragongo and Mt. Nyamulagira (DR Congo) giving reactive bromine mixing ratios from 0.3 ppb (Nyiragongo) up to 22 ppb (Etna, NEC). Compared with total halogen data derived by alkaline trap sampling (Raschig-tube) and ion-chromatography analysis the reactive bromine mixing ratios allow the investigation of the conversion of HBr into reactive species due to plume chemistry with progressing plume age. The new method will be described in detail and the first results on the reactive halogen to total halogen output will be discussed (for bromine and chlorine) and compared to earlier volcanic plume chemistry model studies. References Bobrowski, N. and G. Giuffrida: Bromine monoxide / sulphur dioxide ratios in relation to volcanological observations at Mt. Etna 2006-2009. Solid Earth, 3, 433-445, 2012 Bobrowski, N., R. von Glasow, A. Aiuppa, S. Inguaggiato, I. Louban, O. W. Ibrahim and U. Platt: Reactive halogen chemistry in volcanic plumes. J. Geophys. Res., 112, 2007 Donovan A., V. Tsanev, C. Oppenheimer and M. Edmonds: Reactive halogens (BrO and OClO) detected in the plume of Soufrière Hills Volcano during an eruption hiatus. Geochem. Geophys. Geosyst., 15, 3346-3363, 2014 Rüdiger, J., N. Bobrowski, T. Hoffmann (2015), Development and application of compact denuder sampling techniques with in situ derivatization followed by gas chromatography-mass spectrometry for halogen speciation in volcanic plumes (EGU2015-2392-2), EGU General Assembly 2015

  16. Rapid determination of trace nitrophenolic organics in water by combining solid-phase extraction with surface-assisted laser desorption/ionization time-of-flight mass spectrometry.

    Science.gov (United States)

    Chen, Y C; Shiea, J; Sunner, J

    2000-01-01

    A rapid technique for the screening of trace compounds in water by combining solid-phase extraction (SPE) with activated carbon surface-assisted laser desorption/ionization (SALDI) time-of-flight mass spectrometry is demonstrated. Activated carbon is used both as the sorbent in SPE and as the solid in the SALDI matrix system. This eliminates the need for an SPE elution process. After the analytes have been adsorbed on the surfaces of the activated carbon during SPE extraction, the activated carbon is directly mixed with the SALDI liquid and mass spectrometric analysis is performed. Trace phenolic compounds in water were used to demonstrate the effectiveness of the method. The detection limit for these compounds is in the ppb to ppt range. Copyright 2000 John Wiley & Sons, Ltd.

  17. Solid-state Marx based two-switch voltage modulator for the On-Line Isotope Mass Separator accelerator at the European Organization for Nuclear Research.

    Science.gov (United States)

    Redondo, L M; Silva, J Fernando; Canacsinh, H; Ferrão, N; Mendes, C; Soares, R; Schipper, J; Fowler, A

    2010-07-01

    A new circuit topology is proposed to replace the actual pulse transformer and thyratron based resonant modulator that supplies the 60 kV target potential for the ion acceleration of the On-Line Isotope Mass Separator accelerator, the stability of which is critical for the mass resolution downstream separator, at the European Organization for Nuclear Research. The improved modulator uses two solid-state switches working together, each one based on the Marx generator concept, operating as series and parallel switches, reducing the stress on the series stacked semiconductors, and also as auxiliary pulse generator in order to fulfill the target requirements. Preliminary results of a 10 kV prototype, using 1200 V insulated gate bipolar transistors and capacitors in the solid-state Marx circuits, ten stages each, with an electrical equivalent circuit of the target, are presented, demonstrating both the improved voltage stability and pulse flexibility potential wanted for this new modulator.

  18. Determination of chiral pharmaceuticals and illicit drugs in wastewater and sludge using microwave assisted extraction, solid-phase extraction and chiral liquid chromatography coupled with tandem mass spectrometry.

    Science.gov (United States)

    Evans, Sian E; Davies, Paul; Lubben, Anneke; Kasprzyk-Hordern, Barbara

    2015-07-02

    This is the first study presenting a multi-residue method allowing for comprehensive analysis of several chiral pharmacologically active compounds (cPACs) including beta-blockers, antidepressants and amphetamines in wastewater and digested sludge at the enantiomeric level. Analysis of both the liquid and solid matrices within wastewater treatment is crucial to being able to carry out mass balance within these systems. The method developed comprises filtration, microwave assisted extraction and solid phase extraction followed by chiral liquid chromatography coupled with tandem mass spectrometry to analyse the enantiomers of 18 compounds within all three matrices. The method was successfully validated for 10 compounds within all three matrices (amphetamine, methamphetamine, MDMA, MDA, venlafaxine, desmethylvenlafaxine, citalopram, metoprolol, propranolol and sotalol), 7 compounds validated for the liquid matrices only (mirtazapine, salbutamol, fluoxetine, desmethylcitalopram, atenolol, ephedrine and pseudoephedrine) and 1 compound (alprenolol) passing the criteria for solid samples only. The method was then applied to wastewater samples; cPACs were found at concentration ranges in liquid matrices of: 1.7 ng L(-1) (metoprolol) - 1321 ng L(-1) (tramadol) in influent, solid matrix digested sludge: 0.4 ng g(-1) (metoprolol) - 275 ng g(-1) (citalopram). Enantiomeric profiling revealed that studied compounds were present in analysed samples in non-racemic composition. Furthermore, enantiomeric composition of studied analytes differed in liquid and solid matrices. This demonstrates that not analysing the solid fraction of wastewater may lead to over-estimation of the removal rates of cPACs as well as possible misrepresentation of the enantiomeric fraction of the compounds as they leave the wastewater treatment plant. Consequently risks from cPACs entering the environment might be higher than

  19. Heat and Mass Transfer during Solid-Liquid Phase Transition of n-Alkanes in the C{sub 16} to C{sub 19} Range

    Energy Technology Data Exchange (ETDEWEB)

    Holmen, Rune

    2002-07-01

    The main goal of this project has been to study heat and mass transfer during solid-liquid phase transition of n-alkanes in the in the C{sub 16} to C{sub 19} range. Phase transitions of both mixtures and pure components have been investigated. All experiments and simulations have been performed without any convection. Thermal conductivities have been determined at the melting point for solid and liquid unbranched alkanes ranging from C{sub 16} to C{sub 19}. An assessment of the error of the method has been performed. The measurements of solid conductivities are in accordance with measurements reported previously and confirm the applicability of the method. Liquid conductivities are higher than extrapolated values from the literature. The enhanced conductivity is believed to be caused by structural changes close to the melting point which is not taken into account when extrapolating values from the literature. Experiments have been performed for the purpose of investigating the freezing of mixtures of n-alkanes in the C{sub 16}-C{sub 19} range. The positions of the solid-liquid interfaces have been measured as freezing occurred. Calculations of the ratio of liquid and solid conductivities show that the solid structure of mixtures of the investigated n-alkanes is predominantly in a rotator structure at the temperatures investigated. There are indications of a transformation into an orthorhombic structure at lower temperatures. The temperatures on the solid-liquid interface have been measured, and compared with calculated values from chapter 4. The temperature of the interface is represented better by the measured interfacial temperatures than by the calculated interfacial temperatures. The experimental results indicate that the diffusion of heat is the limiting mechanism of phase transition. This result in a homogeneous liquid composition. A numerical model has been developed in order to simulate the experimental freezing of mixtures. The model represents the results

  20. Differentiation of benign and malignant solid pancreatic masses using magnetic resonance elastography with spin-echo echo planar imaging and three-dimensional inversion reconstruction. A prospective study

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Yu; Yu, Bing; Liu, Yanqing; Guo, Qiyong [Shengjing Hospital of China Medical University, Department of Radiology, Shenyang (China); Gao, Feng [Shengjing Hospital of China Medical University, Department of Hepato-Pancreato-Biliary Tumour Surgery, Shenyang (China); Li, Yue [Shengjing Hospital of China Medical University, Department of Pathology, Shenyang (China); Tao, Shengzhen; Glaser, Kevin J.; Ehman, Richard L. [Mayo Clinic, Department of Radiology, Rochester, MN (United States); Liu, Zaiyi [Guangdong Academy of Medical Sciences, Department of Radiology, Guangdong General Hospital, Guangdong (China)

    2018-03-15

    To determine the diagnostic performance of MR elastography (MRE) and compare it with serum CA19-9 in differentiating malignant from benign pancreatic masses, with emphasis on differentiating between pancreatic ductal adenocarcinoma (PDAC) and mass-forming pancreatitis (MFP). We performed a prospective, consecutive, 24-month study in 85 patients with solid pancreatic masses confirmed by histopathologic examinations. The mass stiffness and stiffness ratio (calculated as the ratio of mass stiffness to the parenchymal stiffness) were assessed. The diagnostic accuracy was analysed by calculating the area under the ROC curve (AUROC). The final diagnosis included 54 malignant tumours (43 patients with PDAC) and 31 benign masses (24 patients with MFP). The stiffness ratio showed better diagnostic performance than the mass stiffness and serum CA19-9 for the differentiation between malignant and benign masses (AUC: 0.912 vs. 0.845 vs. 0.702; P = 0.026, P < 0.001) and, specifically, between PDAC and MFP (AUC: 0.955 vs. 0.882 vs. 0.745; P = 0.026, P = 0.003). The sensitivity, specificity, and accuracy of stiffness ratio for the differentiation of PDAC and MFP were all higher than 0.9. MRE presents an effective and quantitative strategy for non-invasive differentiation between PDAC and MFP based on their mechanical properties. (orig.)

  1. Determination of amphetamine-type stimulants (ATSs) and synthetic cathinones in urine using solid phase micro-extraction fibre tips and gas chromatography-mass spectrometry

    OpenAIRE

    Alsenedi, Khalid A.; Morrison, Calum

    2018-01-01

    In recent years, an increasing number of stimulant drugs and new psychoactive substances (NPSs) have caused concern in scientific communities and therefore innovative methods to extract compounds from complex biological samples are required. This work is aimed at developing and validating a clean, convenient and straightforward extraction procedure with microliter amounts of organic solvent using Solid Phase Micro-Extraction tips (SPME tips) and analysis using Gas Chromatography-Mass Spectrom...

  2. Analysis of lignans in Magnoliae Flos by turbulent flow chromatography with online solid-phase extraction and high-performance liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Zhou, Xuan; Chen, Cen; Ye, Xiaolan; Song, Fenyun; Fan, Guorong; Wu, Fuhai

    2016-04-01

    In this study, a method coupling turbulent flow chromatography with online solid-phase extraction and high-performance liquid chromatography with tandem mass spectrometry was developed for analyzing the lignans in Magnoliae Flos. By the online pretreatment of turbulent flow chromatography solid-phase extraction, the impurities removal and analytes concentration were automatically processed, and the lignans were separated rapidly and well. Seven lignans of Magnoliae Flos including epieudesmin, magnolin, 1-irioresinol-B-dimethyl ether, epi-magnolin, fargesin aschantin, and demethoxyaschantin were identified by comparing their retention behavior, UV spectra, and mass spectra with those of reference substances or literature data. The developed method was validated, and the good results showed that the method was not only automatic and rapid, but also accurate and reliable. The turbulent flow chromatography with online solid-phase extraction and high-performance liquid chromatography with tandem mass spectrometry method holds a high potential to become an effective method for the quality control of lignans in Magnoliae Flos and a useful tool for the analysis of other complex mixtures. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Direct determination of cadmium in foods by solid sampling electrothermal vaporization inductively coupled plasma mass spectrometry using a tungsten coil trap

    Science.gov (United States)

    Zhang, Ying; Mao, Xuefei; Liu, Jixin; Wang, Min; Qian, Yongzhong; Gao, Chengling; Qi, Yuehan

    2016-04-01

    In this work, a solid sampling device consisting of a tungsten coil trap, porous carbon vaporizer and on-line ashing furnace of a Ni-Cr coil was interfaced with inductively coupled plasma mass spectrometry (ICP-MS). A modified double gas circuit system was employed that was composed of carrier and supplemental gas lines controlled by separate gas mass flow controllers. For Cd determination in food samples using the assembled solid sampling ICP-MS, the optimal ashing and vaporization conditions, flow rate of the argon-hydrogen (Ar/H2) (v:v = 24:1) carrier gas and supplemental gas, and minimum sampling mass were investigated. Under the optimized conditions, the limit of quantification was 0.5 pg and the relative standard deviation was within a 10.0% error range (n = 10). Furthermore, the mean spiked recoveries for various food samples were 99.4%-105.9% (n = 6). The Cd concentrations measured by the proposed method were all within the certified values of the reference materials or were not significantly different (P > 0.05) from those of the microwave digestion ICP-MS method, demonstrating the good accuracy and precision of the solid sampling ICP-MS method for Cd determination in food samples.

  4. Generalised model for anisotropic compact stars

    Energy Technology Data Exchange (ETDEWEB)

    Maurya, S.K. [University of Nizwa, Department of Mathematical and Physical Sciences College of Arts and Science, Nizwa (Oman); Gupta, Y.K. [Raj Kumar Goel Institute of Technology, Department of Mathematics, Ghaziabad, Uttar Pradesh (India); Ray, Saibal [Government College of Engineering and Ceramic Technology, Department of Physics, Kolkata, West Bengal (India); Deb, Debabrata [Indian Institute of Engineering Science and Technology, Shibpur, Department of Physics, Howrah, West Bengal (India)

    2016-12-15

    In the present investigation an exact generalised model for anisotropic compact stars of embedding class 1 is sought with a general relativistic background. The generic solutions are verified by exploring different physical aspects, viz. energy conditions, mass-radius relation, stability of the models, in connection to their validity. It is observed that the model presented here for compact stars is compatible with all these physical tests and thus physically acceptable as far as the compact star candidates RXJ 1856-37, SAX J 1808.4-3658 (SS1) and SAX J 1808.4-3658 (SS2) are concerned. (orig.)

  5. Application of direct solid sample analysis for the determination of chlorine in biological materials using electrothermal vaporization inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Santos de Gois, Jefferson; Pereira, Éderson R. [Departamento de Química, Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC (Brazil); Welz, Bernhard [Departamento de Química, Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC (Brazil); INCT de Energia e Ambiente do CNPq (Brazil); Borges, Daniel L.G., E-mail: daniel.borges@ufsc.br [Departamento de Química, Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC (Brazil); INCT de Energia e Ambiente do CNPq (Brazil)

    2015-03-01

    This work describes a methodology developed to carry out Cl determination in biological materials using electrothermal vaporization inductively coupled plasma mass spectrometry and direct solid sample analysis. The solid samples were directly weighed into graphite ‘cups’ and inserted into the graphite furnace. The RF power and the carrier gas flow rate were optimized at 1300 W and 0.7 L min{sup −1}, respectively. Calibration could be carried out using aqueous standard solutions with pre-dried modifiers (Pd + Nd or Pd + Ca) or using solid certified reference materials with the same pre-dried modifiers or without the use of modifiers. The limit of quantification was determined as 5 μg g{sup −1} under optimized conditions and the Cl concentration was determined in five certified reference materials with certified concentrations for Cl, in addition to three certified reference materials, for which certified values for Cl were unavailable; in the latter case, the results were compared with those obtained using high-resolution continuum source molecular absorption spectrometry. Good agreement at a 95% statistical confidence level was achieved between determined and certified or reference values. - Highlights: • Direct determination of chlorine in solid biological materials is described for the first time using ICP-MS. • Calibration against aqueous standards is feasible. • The method is accurate and sensitive, regardless of the composition of the solid sample.

  6. Speciation analysis of inorganic arsenic by magnetic solid phase extraction on-line with inductively coupled mass spectrometry determination.

    Science.gov (United States)

    Montoro Leal, P; Vereda Alonso, E; López Guerrero, M M; Cordero, M T Siles; Cano Pavón, J M; García de Torres, A

    2018-07-01

    Arsenic, one of the main environmental pollutants and potent natural poison, is a chemical element that is spread throughout the Earth's crust. It is well known that the toxicity of arsenic is highly dependent on its chemical forms. Generally, the inorganic species are more toxic than its organics forms, and As(III) is 60 times more toxic than As(V). In environmental waters, arsenic exists predominantly in two chemical forms: As(III) and As(V). In view of these facts, fast, sensitive, accurate and simple analytical methods for the speciation of inorganic arsenic in environmental waters are required. In this work, a new magnetic solid phase extraction with a hydride generation system was coupled on line with inductively coupled plasma mass spectrometry (MSPE-HG-ICP-MS). The new system was based on the retention of As(III) and As(V) in two knotted reactors filled with (Fe 3 O 4 ) magnetic nanoparticles functionalized with [1,5-bis (2-pyridyl) 3-sulfophenylmethylene] thiocarbonohydrazide (PSTH-MNPs). As(III) and total inorganic As were sequentially eluted in different reduction conditions. The concentration of As(V) was obtained by subtracting As(III) from total As. The system runs in a fully automated way and the method has proved to have a wide linear range and to be precise, sensitive and fast. The detection limits found were 2.7 and 3.2 ng/L for As(III) and total As, respectively; with relative standard deviations (RSDs) of 2.5% and 2.7% and a sample throughput of 14.4 h -1 . In order to validate the developed method, several certified reference samples of environmental waters including sea water, were analyzed and the determined values were in good agreement with the certified values. The proposed method was successfully applied to the speciation analysis of inorganic arsenic in well-water and sea water. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. A simple solid-phase extraction method for the analysis of red cell phospholipids by liquid chromatography- tandem mass spectrometry.

    Science.gov (United States)

    Nguyen, Van Long

    2018-02-25

    There has been increasing interest in the analysis of phospholipids in red blood cells as potential long-term biomarkers of different disease states. Here, we describe a simple method for the analysis of two phospholipids: 1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanol (PE 16:0/18:1) and 1-Palmitoyl-2-linoleoyl-sn-glycero-3-phosphoethanol (PE 16:/0/18:2) in erythrocytes by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Whole blood samples were removed free of plasma and washed in isotonic saline. Red cells were lysed with ultrapure water. Lysate samples were processed using a hybrid solid-phase extraction (SPE) phospholipid cartridge (1 mL, 30 mg). Both PE 16:0/18:1 and PE 16:0/18:2 and their deuterated internal standards were separated on an ACE C4 (150 mm × 2.1 mm, 2.7 μm particle size) by gradient elution at a flow rate of 0.5 mL per minute using mobile phases consisting of 0.01 mol/L ammonium acetate in: water (A), methanol (B), and isopropanol (C). The phospholipid species were quantified by the following transitions: PE 16:0/18:1: 701.5→281.3 and PE 16:0/18:2: 699.5→279.3. Both PE species displayed linearity ranging from 10 to 500 μg/L. The coefficient of variation (CV%) of PE 16:0/18:1 concerning intraday and interday precision was between 1.9%-2.6% and 3.0%-4.3%, respectively. For PE 16:0/18:2, this was between 1.8%-3.4% and 3.7%-4.1%, respectively. Both phospholipid species had accuracy (PE 16:0/18:1: 91%-98% and PE 16:0/18:2: 94%-103%) and extraction recovery (PE 16:0/18:1: 95%-106% and PE 16:0/18:2: 92%-102%) exceeding 90% over the analytical range. The limit of detection was 5 μg/L. Here we propose a simple SPE LC-MS/MS method for analyzing phospholipids in erythrocytes, which can be easily adopted. © 2018 Wiley Periodicals, Inc.

  8. Solid-phase microextraction/gas chromatography-mass spectrometry method optimization for characterization of surface adsorption forces of nanoparticles.

    Science.gov (United States)

    Omanovic-Miklicanin, Enisa; Valzacchi, Sandro; Simoneau, Catherine; Gilliland, Douglas; Rossi, Francois

    2014-10-01

    A complete characterization of the different physico-chemical properties of nanoparticles (NPs) is necessary for the evaluation of their impact on health and environment. Among these properties, the surface characterization of the nanomaterial is the least developed and in many cases limited to the measurement of surface composition and zetapotential. The biological surface adsorption index approach (BSAI) for characterization of surface adsorption properties of NPs has recently been introduced (Xia et al. Nat Nanotechnol 5:671-675, 2010; Xia et al. ACS Nano 5(11):9074-9081, 2011). The BSAI approach offers in principle the possibility to characterize the different interaction forces exerted between a NP's surface and an organic--and by extension biological--entity. The present work further develops the BSAI approach and optimizes a solid-phase microextraction gas chromatography-mass spectrometry (SPME/GC-MS) method which, as an outcome, gives a better-defined quantification of the adsorption properties on NPs. We investigated the various aspects of the SPME/GC-MS method, including kinetics of adsorption of probe compounds on SPME fiber, kinetic of adsorption of probe compounds on NP's surface, and optimization of NP's concentration. The optimized conditions were then tested on 33 probe compounds and on Au NPs (15 nm) and SiO2 NPs (50 nm). The procedure allowed the identification of three compounds adsorbed by silica NPs and nine compounds by Au NPs, with equilibrium times which varied between 30 min and 12 h. Adsorption coefficients of 4.66 ± 0.23 and 4.44 ± 0.26 were calculated for 1-methylnaphtalene and biphenyl, compared to literature values of 4.89 and 5.18, respectively. The results demonstrated that the detailed optimization of the SPME/GC-MS method under various conditions is a critical factor and a prerequisite to the application of the BSAI approach as a tool to characterize surface adsorption properties of NPs and therefore to draw any further

  9. Analysis of air-, moisture- and solvent-sensitive chemical compounds by mass spectrometry using an inert atmospheric pressure solids analysis probe.

    Science.gov (United States)

    Mosely, Jackie A; Stokes, Peter; Parker, David; Dyer, Philip W; Messinis, Antonis M

    2018-02-01

    A novel method has been developed that enables chemical compounds to be transferred from an inert atmosphere glove box and into the atmospheric pressure ion source of a mass spectrometer whilst retaining a controlled chemical environment. This innovative method is simple and cheap to implement on some commercially available mass spectrometers. We have termed this approach inert atmospheric pressure solids analysis probe ( iASAP) and demonstrate the benefit of this methodology for two air-/moisture-sensitive chemical compounds whose characterisation by mass spectrometry is now possible and easily achieved. The simplicity of the design means that moving between iASAP and standard ASAP is straightforward and quick, providing a highly flexible platform with rapid sample turnaround.

  10. Self-Compacting Concrete

    OpenAIRE

    Okamura, Hajime; Ouchi, Masahiro

    2003-01-01

    Self-compacting concrete was first developed in 1988 to achieve durable concrete structures. Since then, various investigations have been carried out and this type of concrete has been used in practical structures in Japan, mainly by large construction companies. Investigations for establishing a rational mix-design method and self-compactability testing methods have been carried out from the viewpoint of making self-compacting concrete a standard concrete.

  11. Compact Polarimetry Potentials

    Science.gov (United States)

    Truong-Loi, My-Linh; Dubois-Fernandez, Pascale; Pottier, Eric

    2011-01-01

    The goal of this study is to show the potential of a compact-pol SAR system for vegetation applications. Compact-pol concept has been suggested to minimize the system design while maximize the information and is declined as the ?/4, ?/2 and hybrid modes. In this paper, the applications such as biomass and vegetation height estimates are first presented, then, the equivalence between compact-pol data simulated from full-pol data and compact-pol data processed from raw data as such is shown. Finally, a calibration procedure using external targets is proposed.

  12. Pharmaceutical powder compaction technology

    National Research Council Canada - National Science Library

    Çelik, Metin

    2011-01-01

    "Revised to reflect modern pharmaceutical compacting techniques, this Second Edition guides pharmaceutical engineers, formulation scientists, and product development and quality assurance personnel...

  13. Compact Antenna Range

    Data.gov (United States)

    Federal Laboratory Consortium — Facility consists of a folded compact antenna range including a computer controlled three axis position table, parabolic reflector and RF sources for the measurement...

  14. Characterization of a time-of-flight mass spectrometer and its applications in the study of solid surfaces; Charakterisierung eines Flugzeitmassenspektrometers und seine Anwendungen in der Festkoerperoberflaechenuntersuchung

    Energy Technology Data Exchange (ETDEWEB)

    Mazarov, P.

    2006-12-21

    The object and the purpose of the present work was to develop, to assemble and to start running a new TOF (time of flight) mass spectrometer for imaging SNMS analytic which is optimized for the analysis of highly molecular secondary ions. The most important purpose was the characterization of the TOF mass spectrometer. The obtained mass spectra of indium, tantalum and silver clusters reflect the excellent properties of the TOF mass spectrometer for the detection of large clusters with good detection efficiency up to masses of 16000 amu. The possibility of the deflection of selected saturated atom and cluster peaks serves for further improvement of the detection efficiency for large molecules. The accessible mass resolution was determined to be of the order of m/{delta}m=1000 in the high mass region. Numerous measurements were carried out to characterize the useful yield of this spectrometer. For a best possible adaptation of the TOF mass spectrometer for the detection of highly molecular particles, a device for post-acceleration of the detected particles by up to 10 keV were inserted directly before the MCP detector. The detection efficiency of positive secondary ions was determined for different post-acceleration voltages for the example of sputtered indium cluster ions. In addition, a new method was developed for the quantitative determination of the spectral ionization probability {alpha}{sup +}({nu}) of sputtered particles as a function of the emission velocity. The next application of the TOF mass spectrometer is the analysis of complicated organic molecules in solid state surfaces. During measurements of the photo-ionization behaviour of neutral tryptophan molecules, it was found out that a stable molecular ion signal is generated in the SNMS spectrum with h{nu}=7.9 eV can only be observed by the use of a continuous ion beam or very long (ms range) ion pulses. (orig.)

  15. Characterization of simultaneous heat and mass transfer phenomena for water vapour condensation on a solid surface in an abiotic environment--application to bioprocesses.

    Science.gov (United States)

    Tiwari, Akhilesh; Kondjoyan, Alain; Fontaine, Jean-Pierre

    2012-07-01

    The phenomenon of heat and mass transfer by condensation of water vapour from humid air involves several key concepts in aerobic bioreactors. The high performance of bioreactors results from optimised interactions between biological processes and multiphase heat and mass transfer. Indeed in various processes such as submerged fermenters and solid-state fermenters, gas/liquid transfer need to be well controlled, as it is involved at the microorganism interface and for the control of the global process. For the theoretical prediction of such phenomena, mathematical models require heat and mass transfer coefficients. To date, very few data have been validated concerning mass transfer coefficients from humid air inflows relevant to those bioprocesses. Our study focussed on the condensation process of water vapour and developed an experimental set-up and protocol to study the velocity profiles and the mass flux on a small size horizontal flat plate in controlled environmental conditions. A closed circuit wind tunnel facility was used to control the temperature, hygrometry and hydrodynamics of the flow. The temperature of the active surface was controlled and kept isothermal below the dew point to induce condensation, by the use of thermoelectricity. The experiments were performed at ambient temperature for a relative humidity between 35-65% and for a velocity of 1.0 ms⁻¹. The obtained data are analysed and compared to available theoretical calculations on condensation mass flux.

  16. Electrical properties of the potassium polytitanate compacts

    International Nuclear Information System (INIS)

    Goffman, V.G.; Gorokhovsky, A.V.; Kompan, M.M.; Tretyachenko, E.V.; Telegina, O.S.; Kovnev, A.V.; Fedorov, F.S.

    2014-01-01

    Highlights: • Quasi-static permittivity of potassium polytitanates compacts achieves 10 4 –10 5 . • Observed Maxwell–Wagner polarization attributes to layered structure of polytitanates. • The conductivity varies from 5 × 10 −2 to 10 −6 –10 −7 Sm/m in a wide range of temperatures. - Abstract: Titanates of alkali metals are widely applied materials as they are relatively low in cost and might be easily synthesized. They are utilized as adsorbents, catalysts, solid state electrolytes, superconductors. Here we report our results on electrical properties of the compacted amorphous potassium polytitanates powders. The electrical properties of the compacts were studied by means of complex impedance spectroscopy in a wide range of frequencies at different temperatures using two-electrode configuration. The frequency dependences of conductivity for the investigated potassium polytitanates compacts varies in the range from 5 × 10 −2 Sm/m (high frequencies, ion conductivity) up to 10 −6 –10 −7 Sm/m (low frequencies, electron conductivity) for a wide range of temperatures (19–150 °C). According to the results, at low frequencies quasi-static permittivity of the stabilized PPT compacts achieves high values of 10 4 –10 5 . This might be explained by Maxwell–Wagner polarization attributed to the layered structure of the potassium polytitanates particles containing potassium and hydronium ions together with crystallization water in the interlayer and is very promising for solid state electrolyte applications for moderate temperatures

  17. Compact radio sources

    International Nuclear Information System (INIS)

    Altschuler, D.R.

    1975-01-01

    Eighty-seven compact radio sources were monitored between 1971 and 1974 with the National Radio Astronomy Observatory interferometer. Both flux density and polarization were measured at intervals of about one month at wavelengths of 3.7 and 11.1 cms. Forty-four sources showed definite variability in their total and/or polarized flux density. The variations in polarization were of a shorter time scale than the corresponding flux density variations. Some of the qualitative features of an expanding source model were observed. The data suggest that some form of injection of relativistic electrons is taking place. The absence of significant depolarization in the variable sources indicates that only a small fraction of the mass of the radio outburst is in the form of non-relativistic plasma. Some of the objects observed belong to the BL-Lacertal class. It is shown that this class is very inhomogeneous in its radio properties. For the violently variable BL-Lacertal type objects the spectrum, flux variations and polarization data strongly suggest that these are very young objects

  18. A Case Report: A Third/Fourth Branchial Pouch Anomaly Presented by Solid Thyroid and Lateral Cervical Neck Masses

    OpenAIRE

    Magda H. A. Nasreldin; Eman A. Ibrahim; Somaia A. Saad El-Din

    2016-01-01

    Branchial pouch-derived anomalies may arise from remnants of the first, second, or third/fourth branchial arches. Branchial pouch-related structures are found within the thyroid gland in the form of solid cell rests, epithelial lined cyst with or without an associated lymphoid component, thymic and/or parathyroid tissue, and less commonly in the form of heterotopic cartilage. We present a rare case of left solid thyroid swelling nearby two cervical nodules in a seven-year-old female with a cl...

  19. Recent results of studies of acceleration of compact toroids

    International Nuclear Information System (INIS)

    Hammer, J.H.; Hartman, C.W.; Eddleman, J.

    1984-01-01

    The observed gross stability and self-contained structure of compact toroids (CT's) give rise to the possibility, unique among magnetically confined plasmas, of translating CT's from their point of origin over distances many times their own length. This feature has led us to consider magnetic acceleration of CT's to directed kinetic energies much greater than their stored magnetic and thermal energies. A CT accelerator falls in the very broad gap between traditional particle accelerators at one extreme, which are limited in the number of particles per bunch by electrostatic repulsive forces, and mass accelerators such as rail guns at the other extreme, which accelerate many particles but are forced by the stress limitations of solids to far smaller accelerations. A typical CT has about a Coulomb of particles, weighs 10 micrograms and can be accelerated by magnetic forces of several tons, leading to an acceleration on the order of 10 11 gravities

  20. Compact instantaneous water heater

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Jorge G.W.; Machado, Antonio R.; Ferraz, Andre D.; Rocha, Ivan C.C. da; Konishi, Ricardo [Companhia de Gas de Santa Catarina (SCGAS), Florianopolis, SC (Brazil); Lehmkuhl, Willian A.; Francisco Jr, Roberto W.; Hatanaka, Ricardo L.; Pereira, Fernando M.; Oliveira, Amir A.M. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

    2012-07-01

    This paper presents an experimental study of combustion in an inert porous medium in a liquid heating device application. This project aims to increase efficiency in the application of natural gas in residential and commercial sectors with the use of advanced combustion and heat transfer. The goal is to facilitate the development of a high performance compact water heater allowing hot water supply for up to two simultaneous showers. The experiment consists in a cylindrical porous burner with an integrated annular water heat exchanger. The reactants were injected radially into the burner and the flame stabilizes within the porous matrix. The water circulates in a coiled pipe positioned at the center of the burner. This configuration allows for heat transfer by conduction and radiation from the solid matrix to the heat exchanger. This article presented preliminary experimental results of a new water heater based on an annular porous burner. The range of equivalence ratios tested varied from 0.65 to 0.8. The power range was varied from 3 to 5 kW. Increasing the equivalence ratio or decreasing the total power input of the burner resulted in increased thermal efficiencies of the water heater. Thermal efficiencies varying from 60 to 92% were obtained. The condition for the goal of a comfortable bath was 20 deg C for 8-12 L/min. This preliminary prototype has achieved water temperature of 11deg C for 5 L/min. Further optimizations will be necessary in order to achieve intense heating with high thermal efficiency. (author)

  1. Evaluation of automatic vacuum- assisted compaction solutions

    Directory of Open Access Journals (Sweden)

    M. Brzeziński

    2011-01-01

    Full Text Available Currently on the mould-making machines market the companies like: DiSA, KUENKEL WAGNER, HAFLINGER, HEINRICH WAGNER SINTO, HUNTER, SAVELLI AND TECHNICAL play significant role. These companies are the manufacturers of various solutions in machines and instalations applied in foundry engineering. Automatic foundry machines for compaction of green sand have the major role in mechanisation and automation processes of making the mould. The concept of operation of automatic machines is based on the static and dynamic methods of compacting the green sand. The method which gains the importance is the compacting method by using the energy of the air pressure. It's the initial stage or the supporting process of compacting the green sand. However in the automatic mould making machines using this method it's essential to use the additional compaction of the mass in order to receive the final parameters of the form. In the constructional solutions of the machines there is the additional division which concerns the method of putting the sand into the mould box. This division distinquishes the transport of the sand with simultaneous compaction or the putting of the sand without the pre-compaction. As the solutions of the major manufacturers are often the subject for application in various foundries, the authors of the paper would like/have the confidence to present their own evaluation process confirmed by their own researches and independent analysis of the producers' solutions.

  2. Spherical conformal models for compact stars

    Energy Technology Data Exchange (ETDEWEB)

    Takisa, P.M.; Maharaj, S.D.; Manjonjo, A.M.; Moopanar, S. [University of KwaZulu-Natal, Astrophysics and Cosmology Research Unit, School of Mathematics, Statistics and Computer Science, Durban (South Africa)

    2017-10-15

    We consider spherical exact models for compact stars with anisotropic pressures and a conformal symmetry. The conformal symmetry condition generates an integral relationship between the gravitational potentials. We solve this condition to find a new anisotropic solution to the Einstein field equations. We demonstrate that the exact solution produces a relativistic model of a compact star. The model generates stellar radii and masses consistent with PSR J1614-2230, Vela X1, PSR J1903+327 and Cen X-3. A detailed physical examination shows that the model is regular, well behaved and stable. The mass-radius limit and the surface red shift are consistent with observational constraints. (orig.)

  3. Sensitivity enhancement for nitrophenols using cationic surfactant-modified activated carbon for solid-phase extraction surface-assisted laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Chen, Y C; Tsai, M F

    2000-01-01

    Previous work has demonstrated that a combination of solid-phase extraction with surface-assisted laser desorption/ionization (SPE-SALDI) mass spectrometry can be applied to the determination of trace nitrophenols in water. An improved method to lower the detection limit of this hyphenated technique is described in this present study. Activated carbon powder is used as both the SPE adsorbent and the SALDI solid in the analysis by SPE-SALDI. The surface of the activated carbon is modified by passing an aqueous solution of a cationic surfactant through the SPE cartridge. The results demonstrate that the sensitivity for nitrophenols in the analysis by SPE-SALDI can be improved by using cationic surfactants to modify the surface of the activated carbon. The detection limit for nitrophenols is about 25 ppt based on a signal-to-noise ratio of 3 by sampling from 100 mL of solution. Copyright 2000 John Wiley & Sons, Ltd.

  4. Development of a portable mass spectrometric system for determination of isotopic composition of solid uranium samples using fluorine volatilization. Final report

    International Nuclear Information System (INIS)

    Loge, G.

    1994-01-01

    Using hardware and materials supplied by LANL, a prototype quadrupole mass spectrometer system designed for portable field analysis of isotopic composition of solid uranium samples was assembled and tested. The system contained the capability for fluorine volatilization of solid uranium samples with gas introduction, which was successfully tested and demonstrated using 100 mg samples of U 3 O 8 . Determination of precision and accuracy for measuring isotopic composition was performed using isotopic standards. Use with soil samples containing uranium were also attempted. Silicates in the soil forming SiF 4 were found to be a kinetic bottleneck to the formation of UF 6 . This could be avoided by performing some sort of chemical separation as a pre-treatment step, which was demonstrated using nitric acid

  5. Determination of some selected pesticide residues in apple juice by solid-phase microextraction coupled to gas chromatography – mass spectrometry

    Directory of Open Access Journals (Sweden)

    Andrea Hercegová

    2011-01-01

    Full Text Available The performance of solid phase microextraction (SPME for enrichment of pesticides from apple juice was investigated. Samples were diluted with water, extracted by solid-phase microextraction and analysed by gas chromatography using mass-spectrometry detector (MSD in selected ion monitoring mode (SIM. The method was tested for the following pesticides used mostly in fruit culturing at Slovakia: tebuthylazine, fenitrothion, chlorpyrifos, myclobutanil, cyprodinil, phosalone, pyrimethanil, tebuconazole, kresoxim-methyl, methidathion, penconazole. All pesticides were extracted with polydimethylsiloxane fibre 100 μm thickness. The linear concentration range of application was 0.05 μg dm−3–10 μg dm−3. The method described provides detectabilities complying with the maximum residue levels (MRLs set by regulatory organizations for pesticides in apple juice matrices. The solvent – free SPME procedure was found to be quicker and more cost effective then the solvent extraction methods commonly used.

  6. Breast imaging reporting and data system (BI-RADS) US lexicon and final assessment category for solid breast masses: the rates of inter-and intraobserver agreement

    International Nuclear Information System (INIS)

    Lee, Eun Hye; Cha, Joo Hee; Koh, Young Hwan; Youn, Byung Jae; Cho, Byung Jae; Moon, Woo Kyung

    2007-01-01

    To evaluate the rates of inter-and intraobserver agreement of the BI-RADS US lexicon. Two radiologists reviewed 60 sonograms of solid breast masses to evaluate interobserver agreement. After four weeks, the radiologists reinterpreted the series to evaluate the intraobserver agreement. The radiologists described shape, orientation, margin, lesion boundary, echo pattern, posterior acoustic features and microcalcifications. Final assessment categories and management plans were suggested for each case. The rates of inter-and intraobserver agreements were measured by the use of kappa statistics. Interobserver agreement ranged from the highest for orientation (κ = 0.65) and shape (κ = 0.61) to the lowest for posterior acoustic features (κ = 0.42). For the final assessment categories (κ = 0.46) and management (κ = 0.49), interobserver agreement were moderate. Intraobserver agreement ranged from the highest for microcalcifications in mass (κ = 0.90, 0.82) and orientation (κ 0.87, 0.83) and the lowest for echo patterns (κ = 0.62, 0.57) and posterior acoustic features (κ = 0.59, 0.65). In the final assessment category and management, intraobserver agreements were substantial or nearly complete (κ = 0.65-0.83). There were variable raged inter-and intraobserver agreements in the description of the BI-RADS US lexicon of solid breast masses. Among them, margin and lesion boundary showed lower agreements. A modification of the BI-RADS US lexicon with more detailed guidelines, followed by continuous education, are suggested

  7. Serum protein profiling by miniaturized solid-phase extraction and matrix-assisted laser desorption/ionization mass spectrometry

    DEFF Research Database (Denmark)

    Callesen, Anne K; Mohammed, Shabaz; Bunkenborg, Jakob

    2005-01-01

    for translation of MALDI-MS based diagnostic methods to clinical applications. We have investigated a number of MALDI matrices and several miniaturized solid-phase extraction (SPE) methods for serum protein concentration and desalting with the aim of generating reproducible, high-quality protein profiles by MALDI...

  8. Effluents from a waste rock deposit of a former uranium mine in Saxony/Germany - Mass flow balance of water and dissolved solids

    International Nuclear Information System (INIS)

    Biehler, D.

    2002-01-01

    Soon after uranium mining had ceased in eastern Germany in 1990, work for remediation of several mining sites began. The Wismut GmbH, owner of the Mine of Dresden-Gittersee's waste rock dump, introduced the concept of reducing the impact to the environment via water and air paths by implementing a multi-layer soil cover. The deposit consists mainly of waste rock (clastic sediments of Doehlener Becken, deep metamorphic rocks) but also of low-grade ore (U-rich coal) and tailing materials. At the time when remediation started, the effluents completely infiltrated the underground. Because of previous surface exfiltration activities, they were already known to be very rich in dissolved solids, especially in sulphate and uranium. As demanded by the state authorities, the owner funded a vast hydrogeological study of the site. In testing the efficiency of surface sealing, the study indicated a mass flow balance of water and dissolved solids for the current situation, and predicted emissions into the water path which would occur after realisation of the proposed soil cover. The field investigation program consisted of: measurements of flow, of concentrations of dissolved solids (esp. U and Ra-226) and of contents of environmental isotopes in precipitation, surface runoff, seepage water and groundwater in the current condition of the dump; the study of waste rock material (geochemistry, mineralogy); waste rock material elution tests; underground investigation by drilling boreholes up to 270 m in depth. The resulting data allowed for: a hydrogeological conceptual model of the site; a consistent mass flow balance for the current condition of the dump; a prediction of concentrations in groundwater resulting after the realisation of a soil cover. The predictions show that the concentrations of dissolved solids in the contaminated groundwater would be significantly decreased. Furthermore it would be possible to reach the standards for drinking water with respect to uranium

  9. Uniaxial backfill block compaction

    International Nuclear Information System (INIS)

    Koskinen, V.

    2012-05-01

    The main parts of the project were: to make a literature survey of the previous uniaxial compaction experiments; do uniaxial compaction tests in laboratory scale; and do industrial scale production tests. Object of the project was to sort out the different factors affecting the quality assurance chain of the backfill block uniaxial production and solve a material sticking to mould problem which appeared during manufacturing the blocks of bentonite and cruched rock mixture. The effect of mineralogical and chemical composition on the long term functionality of the backfill was excluded from the project. However, the used smectite-rich clays have been tested for mineralogical consistency. These tests were done in B and Tech OY according their SOPs. The objective of the Laboratory scale tests was to find right material- and compaction parameters for the industrial scale tests. Direct comparison between the laboratory scale tests and industrial scale tests is not possible because the mould geometry and compaction speed has a big influence for the compaction process. For this reason the selected material parameters were also affected by the previous compaction experiments. The industrial scale tests were done in summer of 2010 in southern Sweden. Blocks were done with uniaxial compaction. A 40 tons of the mixture of bentonite and crushed rock blocks and almost 50 tons of Friedland-clay blocks were compacted. (orig.)

  10. Compaction properties of isomalt

    NARCIS (Netherlands)

    Bolhuis, Gerad K.; Engelhart, Jeffrey J. P.; Eissens, Anko C.

    Although other polyols have been described extensively as filler-binders in direct compaction of tablets, the polyol isomalt is rather unknown as pharmaceutical excipient, in spite of its description in all the main pharmacopoeias. In this paper the compaction properties of different types of

  11. Model Compaction Equation

    African Journals Online (AJOL)

    The currently proposed model compaction equation was derived from data sourced from the. Niger Delta and it relates porosity to depth for sandstones under hydrostatic pressure condition. The equation is useful in predicting porosity and compaction trend in hydrostatic sands of the. Niger Delta. GEOLOGICAL SETTING OF ...

  12. Development and verification of a compact TDC-based data acquisition system for space applications

    Energy Technology Data Exchange (ETDEWEB)

    Losekamm, Martin [Physics Department E18, Technische Universitaet Muenchen (Germany); Institute of Astronautics, Technische Universitaet Muenchen (Germany); Gaisbauer, Dominic; Konorov, Igor; Paul, Stephan; Poeschl, Thomas [Physics Department E18, Technische Universitaet Muenchen (Germany)

    2015-07-01

    The advances of solid-state detectors and in particular those for the detection of photons have made their application in space systems increasingly attractive in recent years. The use of, for example, silicon photomultipliers (SiPM) paired with a suitable scintillating material allows the development of compact and lightweight particle detectors. The Antiproton Flux in Space experiment (AFIS) intends to measure the flux of antiprotons trapped in Earth's magnetosphere aboard a nanosatellite using an active target tracking detector, consisting of plastic scintillating fibers read out by SiPMs. In order to implement a large number of detector channels while adhering to the given space, mass and power constraints, the development of a compact TDC-based data acquisition system was proposed. This talk presents a current prototype featuring 900 channels, real-time multi-channel temperature measurement and bias regulation. Possible alternative applications as well as the next steps in the development are also discussed.

  13. Comparison of conventional and automated breast volume ultrasound in the description and characterization of solid breast masses based on BI-RADS features.

    Science.gov (United States)

    Kim, Hyunji; Cha, Joo Hee; Oh, Ha-Yeun; Kim, Hak Hee; Shin, Hee Jung; Chae, Eun Young

    2014-07-01

    To compare the performance of radiologists in the use of conventional ultrasound (US) and automated breast volume ultrasound (ABVU) for the characterization of benign and malignant solid breast masses based on breast imaging and reporting data system (BI-RADS) criteria. Conventional US and ABVU images were obtained in 87 patients with 106 solid breast masses (52 cancers, 54 benign lesions). Three experienced radiologists who were blinded to all examination results independently characterized the lesions and reported a BI-RADS assessment category and a level of suspicion of malignancy. The results were analyzed by calculation of Cohen's κ coefficient and by receiver operating characteristic (ROC) analysis. Assessment of the agreement of conventional US and ABVU indicated that the posterior echo feature was the most discordant feature of seven features (κ = 0.371 ± 0.225) and that orientation had the greatest agreement (κ = 0.608 ± 0.210). The final assessment showed substantial agreement (κ = 0.773 ± 0.104). The areas under the ROC curves (Az) for conventional US and ABVU were not statistically significant for each reader, but the mean Az values of conventional US and ABVU by multi-reader multi-case analysis were significantly different (conventional US 0.991, ABVU 0.963; 95 % CI -0.0471 to -0.0097). The means for sensitivity, specificity, positive predictive value, and negative predictive value of conventional US and ABVU did not differ significantly. There was substantial inter-observer agreement in the final assessment of solid breast masses by conventional US and ABVU. ROC analysis comparing the performance of conventional US and ABVU indicated a marginally significant difference in mean Az, but not in mean sensitivity, specificity, positive predictive value, or negative predictive value.

  14. Stabilization of compactible waste

    International Nuclear Information System (INIS)

    Franz, E.M.; Heiser, J.H. III; Colombo, P.

    1990-09-01

    This report summarizes the results of series of experiments performed to determine the feasibility of stabilizing compacted or compactible waste with polymers. The need for this work arose from problems encountered at disposal sites attributed to the instability of this waste in disposal. These studies are part of an experimental program conducted at Brookhaven National Laboratory (BNL) investigating methods for the improved solidification/stabilization of DOE low-level wastes. The approach taken in this study was to perform a series of survey type experiments using various polymerization systems to find the most economical and practical method for further in-depth studies. Compactible dry bulk waste was stabilized with two different monomer systems: styrene-trimethylolpropane trimethacrylate (TMPTMA) and polyester-styrene, in laboratory-scale experiments. Stabilization was accomplished by wetting or soaking compactible waste (before or after compaction) with monomers, which were subsequently polymerized. Three stabilization methods are described. One involves the in-situ treatment of compacted waste with monomers in which a vacuum technique is used to introduce the binder into the waste. The second method involves the alternate placement and compaction of waste and binder into a disposal container. In the third method, the waste is treated before compaction by wetting the waste with the binder using a spraying technique. A series of samples stabilized at various binder-to-waste ratios were evaluated through water immersion and compression testing. Full-scale studies were conducted by stabilizing two 55-gallon drums of real compacted waste. The results of this preliminary study indicate that the integrity of compacted waste forms can be readily improved to ensure their long-term durability in disposal environments. 9 refs., 10 figs., 2 tabs

  15. Large-scale dynamic compaction of natural salt

    International Nuclear Information System (INIS)

    Hansen, F.D.; Ahrens, E.H.

    1996-01-01

    A large-scale dynamic compaction demonstration of natural salt was successfully completed. About 40 m 3 of salt were compacted in three, 2-m lifts by dropping a 9,000-kg weight from a height of 15 m in a systematic pattern to achieve desired compaction energy. To enhance compaction, 1 wt% water was added to the relatively dry mine-run salt. The average compacted mass fractional density was 0.90 of natural intact salt, and in situ nitrogen permeabilities averaged 9X10 -14 m 2 . This established viability of dynamic compacting for placing salt shaft seal components. The demonstration also provided compacted salt parameters needed for shaft seal system design and performance assessments of the Waste Isolation Pilot Plant

  16. Mass transfer between a fluid and an immersed object in liquid–solid packed and fluidized beds

    Directory of Open Access Journals (Sweden)

    NEVENKA BOSKOVIC-VRAGOLOVIC

    2005-11-01

    Full Text Available Themass transfer coefficient between fluid and an immersed sphere in liquid packed and fluidized beds of inert spherical particles have been studied experimentally using a column 40 mm in diameter. The mass transfer data were obtained by studying the transfer of benzoic acid from the immersed sphere to flowing water using the dissolution method. In all runs, the mass transfer rates were determined in the presence of inert glass particles 0.50-2.98 mm in diameter. The influence of different parameters, such as: liquid velocity, particles size and bed voidage, on the mass transfer in packed and fluidized beds is presented. The obtained experimental data for mass transfer in the packed and particulate fluidized bed were correlated by a single correlation, thus confirming the similarity between the two systems.

  17. A Case Report: A Third/Fourth Branchial Pouch Anomaly Presented by Solid Thyroid and Lateral Cervical Neck Masses.

    Science.gov (United States)

    Nasreldin, Magda H A; Ibrahim, Eman A; Saad El-Din, Somaia A

    2016-01-01

    Branchial pouch-derived anomalies may arise from remnants of the first, second, or third/fourth branchial arches. Branchial pouch-related structures are found within the thyroid gland in the form of solid cell rests, epithelial lined cyst with or without an associated lymphoid component, thymic and/or parathyroid tissue, and less commonly in the form of heterotopic cartilage. We present a rare case of left solid thyroid swelling nearby two cervical nodules in a seven-year-old female with a clinical diagnosis suggestive of malignant thyroid tumor with metastasis to the cervical lymph nodes. Histopathological examination revealed that it was compatible with third/fourth branchial pouch-derived anomaly composed of mature cartilage and thymic and parathyroid tissues for clinical and radiological correlations.

  18. A Case Report: A Third/Fourth Branchial Pouch Anomaly Presented by Solid Thyroid and Lateral Cervical Neck Masses

    Directory of Open Access Journals (Sweden)

    Magda H. A. Nasreldin

    2016-01-01

    Full Text Available Branchial pouch-derived anomalies may arise from remnants of the first, second, or third/fourth branchial arches. Branchial pouch-related structures are found within the thyroid gland in the form of solid cell rests, epithelial lined cyst with or without an associated lymphoid component, thymic and/or parathyroid tissue, and less commonly in the form of heterotopic cartilage. We present a rare case of left solid thyroid swelling nearby two cervical nodules in a seven-year-old female with a clinical diagnosis suggestive of malignant thyroid tumor with metastasis to the cervical lymph nodes. Histopathological examination revealed that it was compatible with third/fourth branchial pouch-derived anomaly composed of mature cartilage and thymic and parathyroid tissues for clinical and radiological correlations.

  19. Mass removal modes in the laser ablation of silicon by a Q-switched diode-pumped solid-state laser (DPSSL)

    International Nuclear Information System (INIS)

    Lim, Daniel J; Ki, Hyungson; Mazumder, Jyoti

    2006-01-01

    A fundamental study on the Q-switched diode-pumped solid-state laser interaction with silicon was performed both experimentally and numerically. Single pulse drilling experiments were conducted on N-type silicon wafers by varying the laser intensity from 10 8 -10 9 W cm -2 to investigate how the mass removal mechanism changes depending on the laser intensity. Hole width and depth were measured and surface morphology was studied using scanning electron microscopy. For the numerical model study, Ki et al's self-consistent continuous-wave laser drilling model (2001 J. Phys. D: Appl. Phys. 34 364-72) was modified to treat the solidification phenomenon between successive laser pulses. The model has the capabilities of simulating major interaction physics, such as melt flow, heat transfer, evaporation, homogeneous boiling, multiple reflections and surface evolution. This study presents some interesting results on how the mass removal mode changes as the laser intensity increases

  20. THE PROCESS OF MASS TRANSFER ON THE SOLID-LIQUID BOUNDARY LAYER DURING THE RELEASE OF DICLOFENAC SODIUM AND PAPAVERINE HYDROCHLORIDE FROM TABLETS IN A PADDLE APPARATUS.

    Science.gov (United States)

    Kasperek, Regina; Zimmer, Lukasz; Poleszak, Ewa

    2016-01-01

    The release study of diclofenac sodium (DIC) and papaverine hydrochloride (PAP) from two formulations of the tablets in the paddle apparatus using different rotation speeds to characterize the process of mass transfer on the solid-liquid boundary layer was carried out. The dissolution process of active substances was described by values of mass transfer coefficients, the diffusion boundary layer thickness and dimensionless numbers (Sh and Re). The values of calculated parameters showed that the release of DIC and PAP from tablets comprising potato starch proceeded faster than from tablets containing HPMC and microcrystalline cellulose. They were obtained by direct dependencies between Sh and Re in the range from 75 rpm to 125 rpm for both substances from all tablets. The description of the dissolution process with the dimensionless numbers make it possible to plan the drug with the required release profile under given in vitro conditions.

  1. Is it useful for distinguishing between benign and malignant solid breast masses?: diagnostic criteria of Japan society of ultrasonics in medicine (JSUM)

    International Nuclear Information System (INIS)

    Yoon, Jeong Hee; Kim, Sun Hee; Chung, Chun Phil

    1995-01-01

    To evaluate the effectiveness and the most accurate element of the diagnostic criteria of the Japan Society of Ultrasonics in medicine (JSUM, Nov. 1989) for distinguishing between benign and malignant solid breast masses on the US. We analyzed the ultrasonic findings of histopathologically proved 51 fibroadenomas, 12 fibrocystic disease, and 39 breast cancers in relation to the diagnostic criteria of the JSUM (shape, border, boundary echo, internal echo, posterior echo, lateral echo, and depth/width ratio). The number of cases of fibroadenoma, fibrocystic disease, and breast cancer corresponding to the diagnostic criteria was in the shape (26/51, 5/12, 33/39), border (41/51, 9/12, 29/39), boundary echo (48/51, 12/12, 27/39) internal echo (43/51, 9/12, 24/39), posterior echo (32/51, 3/12, 21/39), and lateral shadowing (15/51, 1/12, 35/39). All diagnostic criterias showed statistical significance for differentiation of benign/malignant breast mass on the US (Chi-square test: ρ < 0.05). The order of accuracy was boundary echo, internal echo, and border. The mean of depth/width ratio was 0.54 ± 0.15, 0.52 ± 0.12, and 0.69 ± 0.21 in fibroadenoma, fibrocystic disease, and breast cancer respectively and it had statistical significance for differentiation of benign/malignant breast mass on the US (ANOVA test: ρ = 0.0002). The diagnostic criteria of JSUM is effective for differentiation of benign/malignant breast solid masses on the US and has accuracy in the order of boundary echo, internal echo, and border. Depth/width ratio also has statistical significance

  2. Is it useful for distinguishing between benign and malignant solid breast masses?: diagnostic criteria of Japan society of ultrasonics in medicine (JSUM)

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jeong Hee; Kim, Sun Hee; Chung, Chun Phil [Maryknoll Hospital, Busan (Korea, Republic of)

    1995-10-15

    To evaluate the effectiveness and the most accurate element of the diagnostic criteria of the Japan Society of Ultrasonics in medicine (JSUM, Nov. 1989) for distinguishing between benign and malignant solid breast masses on the US. We analyzed the ultrasonic findings of histopathologically proved 51 fibroadenomas, 12 fibrocystic disease, and 39 breast cancers in relation to the diagnostic criteria of the JSUM (shape, border, boundary echo, internal echo, posterior echo, lateral echo, and depth/width ratio). The number of cases of fibroadenoma, fibrocystic disease, and breast cancer corresponding to the diagnostic criteria was in the shape (26/51, 5/12, 33/39), border (41/51, 9/12, 29/39), boundary echo (48/51, 12/12, 27/39) internal echo (43/51, 9/12, 24/39), posterior echo (32/51, 3/12, 21/39), and lateral shadowing (15/51, 1/12, 35/39). All diagnostic criterias showed statistical significance for differentiation of benign/malignant breast mass on the US (Chi-square test: {rho} < 0.05). The order of accuracy was boundary echo, internal echo, and border. The mean of depth/width ratio was 0.54 {+-} 0.15, 0.52 {+-} 0.12, and 0.69 {+-} 0.21 in fibroadenoma, fibrocystic disease, and breast cancer respectively and it had statistical significance for differentiation of benign/malignant breast mass on the US (ANOVA test: {rho} = 0.0002). The diagnostic criteria of JSUM is effective for differentiation of benign/malignant breast solid masses on the US and has accuracy in the order of boundary echo, internal echo, and border. Depth/width ratio also has statistical significance.

  3. Small Valdivia compact spaces

    CERN Document Server

    Kubi's, W; Kubi\\'s, Wieslaw; Michalewski, Henryk

    2005-01-01

    We prove a preservation theorem for the class of Valdivia compact spaces, which involves inverse sequences of ``simple'' retractions. Consequently, a compact space of weight $\\loe\\aleph_1$ is Valdivia compact iff it is the limit of an inverse sequence of metric compacta whose bonding maps are retractions. As a corollary, we show that the class of Valdivia compacta of weight at most $\\aleph_1$ is preserved both under retractions and under open 0-dimensional images. Finally, we characterize the class of all Valdivia compacta in the language of category theory, which implies that this class is preserved under all continuous weight preserving functors.

  4. Determination of organophosphate flame retardants in soil and fish using ultrasound-assisted extraction, solid-phase clean-up, and liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Lorenzo, María; Campo, Julián; Picó, Yolanda

    2018-03-22

    A solid-liquid extraction method in combination with high-performance liquid chromatography and tandem mass spectrometry was developed and optimized for extraction and analysis of organophosphorus flame retardants in soil and fish. Methanol was chosen as the optimum extraction solvent, not only in terms of extraction efficiency, but also for its broader analyte coverage. The subsequent clean-up by solid-phase extraction is required to eliminate matrix coextractives and reduce matrix effects. Recoveries of the optimized method were 50-121% for soil and 47-123% for biota, both with high precision (RSDs solid-phase extraction cartridge clogging that increase variability and analysis time. The method was successfully applied for the determination of organophosphorus flame retardants in soil and fish from L'Albufera Natural Park (Valencia, Spain). Target compounds were detected in all soil and fish samples with values varying from 13.8 to 89.7 ng/g dry weight and from 3.3 to 53.0 ng/g wet weight, respectively. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Determination of haloacetic acids in water using layered double hydroxides as a sorbent in dispersive solid-phase extraction followed by liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Alsharaa, Abdulnaser; Sajid, Muhammad; Basheer, Chanbasha; Alhooshani, Khalid; Lee, Hian Kee

    2016-09-01

    In the present study, highly efficient and simple dispersive solid-phase extraction procedure for the determination of haloacetic acids in water samples has been established. Three different types of layered double hydroxides were synthesized and used as a sorbent in dispersive solid-phase extraction. Due to the interesting behavior of layered double hydroxides in an acidic medium (pH˂4), the analyte elution step was not needed; the layered double hydroxides are simply dissolved in acid immediately after extraction to release the analytes which are then directly introduced into a liquid chromatography with tandem mass spectrometry system for analysis. Several dispersive solid-phase extraction parameters were optimized to increase the extraction efficiency of haloacetic acids such as temperature, extraction time and pH. Under optimum conditions, good linearity was achieved over the concentration range of 0.05-100 μg/L with detection limits in the range of 0.006-0.05 μg/L. The relative standard deviations were 0.33-3.64% (n = 6). The proposed method was applied to different water samples collected from a drinking water plant to determine the concentrations of haloacetic acids. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Analysis of cocaine and its metabolites from biological specimens using solid-phase extraction and positive ion chemical ionization mass spectrometry.

    Science.gov (United States)

    Crouch, D J; Alburges, M E; Spanbauer, A C; Rollins, D E; Moody, D E

    1995-10-01

    An accurate and reliable gas chromatographic-mass spectrometric method was developed to analyze tissue, whole blood, plasma, and urine samples for cocaine (COC) and its major metabolites. COC, benzoylecgonine (BZE), and ecgonine methyl ester (EME) were isolated from the biological matrix using solid-phase extraction, and the tert-butyldimethylsilyl derivatives of BZE, EME, and their deuterium-labeled internal standards were formed. Separation of the compounds was performed by capillary chromatography, and analysis was performed by positive ion chemical ionization mass spectrometry using methane and ammonia as the reagent gases. The tert-butyldimethylsilyl derivatives of BZE and EME were stable and produced mass spectral ions with higher mass-to-charge ratios than trimethylsilyl derivatives. Recovery of COC and its metabolites exceeded 80% at all three concentrations tested. Linearity of the method was established from 2.5 to 2000 microg/L. Intra-assay precision had a coefficient of variation (CV) of less than 9% for all analytes when tested at 10, 25, 100, and 200 microg/L. Interassay precision also had a CV of less than 9% for COC, BZE, and EME at 25 and 100 microg/L. At 200 microg/L, %CVs for COC, BZE, and EME were 11.5, 12.0, and 12.7, respectively. In addition to the analysis of COC, BZE, and EME, the method was used to quantitate cocaethylene and to identify norcocaine.

  7. A general screening method for doping agents in human urine by solid phase extraction and liquid chromatography/time-of-flight mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Kolmonen, Marjo [Forensic Toxicology Division, Department of Forensic Medicine, University of Helsinki (Finland) and Doping Control Laboratory, United Laboratories Ltd., Helsinki (Finland)]. E-mail: marjo.kolmonen@helsinki.fi; Leinonen, Antti [Doping Control Laboratory, United Laboratories Ltd., Helsinki (Finland); Pelander, Anna [Forensic Toxicology Division, Department of Forensic Medicine, University of Helsinki (Finland); Ojanperae, Ilkka [Forensic Toxicology Division, Department of Forensic Medicine, University of Helsinki (Finland)

    2007-02-28

    A general screening method based on solid phase extraction (SPE) and liquid chromatography/time-of-flight mass spectrometry (LC/TOFMS) was developed and investigated with 124 different doping agents, including stimulants, {beta}-blockers, narcotics, {beta}{sub 2}-adrenergic agonists, agents with anti-estrogenic activity, diuretics and cannabinoids. Mixed mode cation exchange/C8 cartridges were applied to SPE, and chromatography was based on gradient elution on a C18 column. Ionization of the analytes was achieved with electrospray ionization in the positive mode. Identification by LC/TOFMS was based on retention time, accurate mass and isotopic pattern. Validation of the method consisted of analysis of specificity, analytical recovery, limit of detection and repeatability. The minimum required performance limit (MRPL), established by World Anti-Doping Agency (WADA), was attained to 97 doping agents. The extraction recoveries varied between 33 and 98% and the median was 58%. Mass accuracy was always better than 5 ppm, corresponding to a maximum mass error of 0.7 mDa. The repeatability of the method for spiked urine samples, expressed as median of relative standard deviations (RSD%) at concentrations of MRPL and 10 times MRPL, were 14% and 9%, respectively. The suitability of the LC/TOFMS method for doping control was demonstrated with authentic urine samples.

  8. Preconcentration and Determination of Perfluoroalkyl Substances (PFASs in Water Samples by Bamboo Charcoal-Based Solid-Phase Extraction Prior to Liquid Chromatography–Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Ze-Hui Deng

    2018-04-01

    Full Text Available In this work, bamboo charcoal was used as solid-phase extraction adsorbent for the enrichment of six perfluoroalkyl acids (PFAAs in environmental water samples before liquid chromatography–tandem mass spectrometry analysis. The specific porous structure, high specific surface area, high porosity, and stability of bamboo charcoal were characterized. Several experimental parameters which considerably affect extraction efficiency were investigated and optimized in detail. The experimental data exhibited low limits of detection (LODs (0.01–1.15 ng/L, wide linear range (2–3 orders of magnitude and R ≥ 0.993 within the concentration range of 0.1–1000 ng/L, and good repeatability (2.7–5.0%, n = 5 intraday and 4.8–8.3%, n = 5 interday and reproducibility (5.3–8.0%, n = 3. Bamboo charcoal was successfully used for the enrichment and determination of PFAAs in real environmental water samples. The bamboo charcoal-based solid-phase extraction coupled with liquid chromatography–tandem mass spectrometry analysis possessed great potential in the determination of trace PFAA levels in environmental water samples.

  9. Analysis of volatile organic compounds in pleural effusions by headspace solid-phase microextraction coupled with cryotrap gas chromatography and mass spectrometry.

    Science.gov (United States)

    Huang, Zhongping; Zhang, Jie; Zhang, Peipei; Wang, Hong; Pan, Zaifa; Wang, Lili

    2016-07-01

    Headspace solid-phase microextraction coupled with cryotrap gas chromatography and mass spectrometry was applied to the analysis of volatile organic compounds in pleural effusions. The highly volatile organic compounds were separated successfully with high sensitivity by the employment of a cryotrap device, with the construction of a cold column head by freezing a segment of metal capillary with liquid nitrogen. A total of 76 volatile organic compounds were identified in 50 pleural effusion samples (20 malignant effusions and 30 benign effusions). Among them, 34 more volatile organic compounds were detected with the retention time less than 8 min, by comparing with the normal headspace solid-phase microextraction coupled with gas chromatography and mass spectrometry method. Furthermore, 24 volatile organic compounds with high occurrence frequency in pleural effusion samples, 18 of which with the retention time less than 8 min, were selected for the comparative analysis. The results of average peak area comparison and box-plot analysis showed that except for cyclohexanone, 2-ethyl-1-hexanol, and tetramethylbenzene, which have been reported as potential cancer biomarkers, cyclohexanol, dichloromethane, ethyl acetate, n-heptane, ethylbenzene, and xylene also had differential expression between malignant and benign effusions. Therefore, the proposed approach was valuable for the comprehensive characterization of volatile organic compounds in pleural effusions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Analysis of trace levels of sulfonamide and tetracycline antimicrobials in groundwater and surface water using solid-phase extraction and liquid chromatography/mass spectrometry

    Science.gov (United States)

    Lindsey, M.E.; Meyer, M.; Thurman, E.M.

    2001-01-01

    A method has been developed for the trace analysis of two classes of antimicrobials consisting of six sulfonamides (SAs) and five tetracyclines (TCs), which commonly are used for veterinary purposes and agricultural feed additives and are suspected to leach into ground and surface water. The method used solid-phase extraction and liquid chromatography/mass spectrometry (LC/MS) with positive ion electrospray. The unique combination of a metal chelation agent (Na2EDTA) with a macroporous copolymer resulted in quantitative recoveries by solid-phase extraction (mean recovery, 98 ?? 12%) at submicrogram-per-liter concentrations. An ammonium formate/formic acid buffer with a methanol/water gradient was used to separate the antimicrobials and to optimize the signal intensity. Mass spectral fragmentation and ionization characteristics were determined for each class of compounds for unequivocal identification. For all SAs, a characteristic m/z 156 ion representing the sulfanilyl fragment was identified. TCs exhibited neutral losses of 17 amu resulting from the loss of ammonia and 35 amu from the subsequent loss of water. Unusual matrix effects were seen only for TCs in this first survey of groundwater and surface water samples from sites around the United States, requiring that TCs be quantitated using the method of standard additions.

  11. Magnetic micro-solid-phase extraction based on magnetite-MCM-41 with gas chromatography-mass spectrometry for the determination of antidepressant drugs in biological fluids.

    Science.gov (United States)

    Kamaruzaman, Sazlinda; Sanagi, Mohd Marsin; Yahaya, Noorfatimah; Wan Ibrahim, Wan Aini; Endud, Salasiah; Wan Ibrahim, Wan Nazihah

    2017-11-01

    A new facile magnetic micro-solid-phase extraction coupled to gas chromatography and mass spectrometry detection was developed for the extraction and determination of selected antidepressant drugs in biological fluids using magnetite-MCM-41 as adsorbent. The synthesized sorbent was characterized by several spectroscopic techniques. The maximum extraction efficiency for extraction of 500 μg/L antidepressant drugs from aqueous solution was obtained with 15 mg of magnetite-MCM-41 at pH 12. The analyte was desorbed using 100 μL of acetonitrile prior to gas chromatography determination. This method was rapid in which the adsorption procedure was completed in 60 s. Under the optimized conditions using 15 mL of antidepressant drugs sample, the calibration curve showed good linearity in the range of 0.05-500 μg/L (r 2  = 0.996-0.999). Good limits of detection (0.008-0.010 μg/L) were obtained for the analytes with good relative standard deviations of solid-phase extraction with gas chromatography and mass spectrometry is a convenient, fast, and economical method for the extraction and determination of amitriptyline and chlorpromazine in biological samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Harmonic Contrast-Enhanced Endoscopic Ultrasonography for the Guidance of Fine-Needle Aspiration in Solid Pancreatic Masses

    DEFF Research Database (Denmark)

    Seicean, A; Badea, R; Moldovan-Pop, A

    2015-01-01

    Purpose: The global accuracy of fine-needle aspiration guided by endoscopic ultrasound (EUS-FNA) for pancreatic adenocarcinoma is about 85 %. The use of contrast agents during EUS to highlight vessels and the necrotic parts of pancreatic masses may improve biopsy guidance. Our aim was to assess...... whether the guidance of FNA by harmonic contrast-enhanced endoscopic ultrasound (CH-EUS) would increase diagnostic accuracy relative to conventional EUS-FNA in the same pancreatic masses. Patients and Methods: In a prospective study, EUS-FNA was performed in patients with pancreatic masses on CT scan......, followed by harmonic CH-EUS using SonoVue. A second cluster of CH-EUS-FNA was performed on contrast-enhanced images. The final diagnosis was based on the results of EUS-FNA and surgery, or the findings after 12 months' follow-up. Results: The final diagnosis was adenocarcinoma (n = 35), chronic...

  13. Shear-wave elastography in the diagnosis of solid breast masses: what leads to false-negative or false-positive results?

    Science.gov (United States)

    Yoon, Jung Hyun; Jung, Hae Kyoung; Lee, Jong Tae; Ko, Kyung Hee

    2013-09-01

    To investigate the factors that have an effect on false-positive or false-negative shear-wave elastography (SWE) results in solid breast masses. From June to December 2012, 222 breast lesions of 199 consecutive women (mean age: 45.3 ± 10.1 years; range, 21 to 88 years) who had been scheduled for biopsy or surgical excision were included. Greyscale ultrasound and SWE were performed in all women before biopsy. Final ultrasound assessments and SWE parameters (pattern classification and maximum elasticity) were recorded and compared with histopathology results. Patient and lesion factors in the 'true' and 'false' groups were compared. Of the 222 masses, 175 (78.8 %) were benign, and 47 (21.2 %) were malignant. False-positive rates of benign masses were significantly higher than false-negative rates of malignancy in SWE patterns, 36.6 % to 6.4 % (P masses, factors showing significance among false SWE features were lesion size, breast thickness and lesion depth (all P breast masses had SWE images of good quality. False SWE features were more significantly seen in benign masses. Lesion size, breast thickness and lesion depth have significance in producing false results, and this needs consideration in SWE image acquisition. • Shear-wave elastography (SWE) is widely used during breast imaging • At SWE, false-positive rates were significantly higher than false-negative rates • Larger size, breast thickness, depth and fair quality influences false-positive SWE features • Smaller size, larger breast thickness and depth influences false-negative SWE features.

  14. Characterization of three agave species by gas chromatography and solid-phase microextraction-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Peña-Alvarez, Araceli; Díaz, Laura; Medina, Alejandra; Labastida, Carmen; Capella, Santiago; Vera, Luz Elena

    2004-02-20

    Steam distillation (SD) extraction-solid-phase microextraction coupled to GC-MS was developed for the determination of terpenes and Bligh-Dyer extraction-derivatization coupled with GC for the determination of fatty acids such as ethyl esters were used. It was found that the three different Agave species have the same profile of fatty acids; the quantity of these compounds is different in each Agave variety. On the other hand, different terpenes were identified in the three Agave plants studied: nine in A. salmiana, eight in A. angustifolia and 32 in A. tequilana Weber var. azul.

  15. Compact turbidity meter

    Science.gov (United States)

    Hirschberg, J. G.

    1979-01-01

    Proposed monitor that detects back-reflected infrared radiation makes in situ turbidity measurements of lakes, streams, and other bodies of water. Monitor is compact, works well in daylight as at night, and is easily operated in rough seas.

  16. General Relativity and Compact Stars

    International Nuclear Information System (INIS)

    Glendenning, Norman K.

    2005-01-01

    Compact stars--broadly grouped as neutron stars and white dwarfs--are the ashes of luminous stars. One or the other is the fate that awaits the cores of most stars after a lifetime of tens to thousands of millions of years. Whichever of these objects is formed at the end of the life of a particular luminous star, the compact object will live in many respects unchanged from the state in which it was formed. Neutron stars themselves can take several forms--hyperon, hybrid, or strange quark star. Likewise white dwarfs take different forms though only in the dominant nuclear species. A black hole is probably the fate of the most massive stars, an inaccessible region of spacetime into which the entire star, ashes and all, falls at the end of the luminous phase. Neutron stars are the smallest, densest stars known. Like all stars, neutron stars rotate--some as many as a few hundred times a second. A star rotating at such a rate will experience an enormous centrifugal force that must be balanced by gravity or else it will be ripped apart. The balance of the two forces informs us of the lower limit on the stellar density. Neutron stars are 10 14 times denser than Earth. Some neutron stars are in binary orbit with a companion. Application of orbital mechanics allows an assessment of masses in some cases. The mass of a neutron star is typically 1.5 solar masses. They can therefore infer their radii: about ten kilometers. Into such a small object, the entire mass of our sun and more, is compressed

  17. Binding Energy and Equilibrium of Compact Objects

    Directory of Open Access Journals (Sweden)

    Germano M.

    2014-04-01

    Full Text Available The theoretical analysis of the existence of a limit mass for compact astronomic ob- jects requires the solution of the Einstein’s equations of g eneral relativity together with an appropriate equation of state. Analytical solutions exi st in some special cases like the spherically symmetric static object without energy sou rces that is here considered. Solutions, i.e. the spacetime metrics, can have a singular m athematical form (the so called Schwarzschild metric due to Hilbert or a nonsingula r form (original work of Schwarzschild. The former predicts a limit mass and, conse quently, the existence of black holes above this limit. Here it is shown that, the origi nal Schwarzschild met- ric permits compact objects, without mass limit, having rea sonable values for central density and pressure. The lack of a limit mass is also demonst rated analytically just imposing reasonable conditions on the energy-matter densi ty, of positivity and decreas- ing with radius. Finally the ratio between proper mass and to tal mass tends to 2 for high values of mass so that the binding energy reaches the lim it m (total mass seen by a distant observer. As it is known the negative binding energ y reduces the gravitational mass of the object; the limit of m for the binding energy provides a mechanism for stable equilibrium of any amount of mass to contrast the gravitatio nal collapse.

  18. A study of the solid-phase thermal decomposition of NTO using simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS)

    Energy Technology Data Exchange (ETDEWEB)

    Minier, L.; Behrens, R. [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility; Burkey, T.J. [Univ. of Memphis, TN (United States). Chemistry Dept.

    1997-01-01

    The solid phase thermal reaction chemistry of NTO between 190 and 250 C is presently being evaluated by utilizing STMBMS, a technique that enables the authors to measure the vapor pressure of NTO and to explore the reaction mechanisms and chemical kinetics associated with the NTO thermal decomposition process. The vapor pressure of NTO is expressed as Log{sub 10} p(torr) = 12.5137 + 6,296.553(1/t{sub k}) and the {Delta}H{sub subl} = 28.71 {+-} 0.07 kcal/mol (120.01 {+-} 0.29 kJ/mol). The pyrolysis of NTO results in the formation of gaseous products and a condensed-phase residue. The identity of the major gaseous products and their origin from within the NTO molecules are determined based on the results from pyrolysis of NTO, NTO-3-{sup 13}C, NTO-1,2-{sup 15}N{sub 2} and NTO-{sup 2}H{sub 2}. Identification of the products show the major gaseous products to be N{sub 2}, CO{sub 2}, NO, HNCO, H{sub 2}O and some N{sub 2}O, CO, HCN and NH{sub 3}. The N{sub 2} is mostly derived from the N-1 and N-2 positions with some being from the N-4 and N-1 or N-2 positions. The CO{sub 2} is derived from both carbons in the NTO molecule in comparable amounts. The residue has an elemental formula of C{sub 2.1}H{sub .26}N{sub 2.9}O and FTIR analysis suggests that the residue is polyurea- and polycarbamate-like in nature. The temporal behaviors of the rates of formation of the gaseous products indicate that the overall thermal decomposition of NTO in the temperature range evaluated involves four major processes: (1) NTO sublimation; (2) an apparent solid-solid phase transition between 190 and 195 C; (3) a decomposition regime induced by the presence of exogenous H{sub 2}O at the onset of decomposition; and (4) a decomposition regime that occurs at the onset of decomposition and continues until the depletion of NTO. Decomposition pathways that are consistent with the data are presented.

  19. Feasible way of Human Solid and Liquid Wastes' Inclusion Into Intersystem Mass Exchange of Biological-Technical Life Support Systems

    Science.gov (United States)

    Ushakova, Sofya; Tikhomirov, Alexander A.; Tikhomirova, Natalia; Kudenko, Yurii; Griboskaya, Illiada; Gros, Jean-Bernard; Lasseur, Christophe

    The basic objective arising at use of mineralized human solid and liquid wastes serving as the source of mineral elements for plants cultivation in biological-technical life support systems appears to be NaCl presence in them. The given work is aimed at feasibility study of mineralized human metabolites' utilization for nutrient solutions' preparation for their further employment at a long-term cultivation of uneven-aged wheat and Salicornia europaea L. cenosis in a conveyer regime. Human solid and liquid wastes were mineralized by the "wet incineration" method developed by Yu. Kudenko. On their base the solutions were prepared which were used for cultivation of 5-aged wheat conveyer with the time step-interval of 14 days. Wheat was cultivated by hydroponics method on expanded clay aggregate. For partial demineralization of nutrient solution every two weeks after regular wheat harvesting 12 L of solution was withdrawn from the wheat irrigation tank and used for Salicornia europaea cultivation by the water culture method in a conveyer regime. The Salicornia europaea conveyer was represented by 2 ages with the time step-interval of 14 days. Resulting from repeating withdrawal of the solution used for wheat cultivation, sodium concentration in the wheat irrigation solution did not exceed 400 mg/l, and mineral elements contained in the taken solution were used for Salicornia europaea cultivation. The experiment lasted 7 months. Total wheat biomass productivity averaged 30.1 g*m-2*day-1 at harvest index equal to 36.8The work was carried out under support of SB RAS grant 132 and INTAS 05-1000008-8010

  20. Compaction of FGD-gypsum

    NARCIS (Netherlands)

    Stoop, B.T.J.; Larbi, J.A.; Heijnen, W.M.M.

    1996-01-01

    It is shown that it is possible to produce compacted gypsum with a low porosity and a high strength on a laboratory scale by uniaxial compaction of flue gas desulphurization (FGD-) gypsum powder. Compacted FGD-gypsum cylinders were produced at a compaction pres-sure between 50 and 500 MPa yielding

  1. Assessment of a new method for the analysis of decomposition gases of polymers by a combining thermogravimetric solid-phase extraction and thermal desorption gas chromatography mass spectrometry.

    Science.gov (United States)

    Duemichen, E; Braun, U; Senz, R; Fabian, G; Sturm, H

    2014-08-08

    For analysis of the gaseous thermal decomposition products of polymers, the common techniques are thermogravimetry, combined with Fourier transformed infrared spectroscopy (TGA-FTIR) and mass spectrometry (TGA-MS). These methods offer a simple approach to the decomposition mechanism, especially for small decomposition molecules. Complex spectra of gaseous mixtures are very often hard to identify because of overlapping signals. In this paper a new method is described to adsorb the decomposition products during controlled conditions in TGA on solid-phase extraction (SPE) material: twisters. Subsequently the twisters were analysed with thermal desorption gas chromatography mass spectrometry (TDS-GC-MS), which allows the decomposition products to be separated and identified using an MS library. The thermoplastics polyamide 66 (PA 66) and polybutylene terephthalate (PBT) were used as example polymers. The influence of the sample mass and of the purge gas flow during the decomposition process was investigated in TGA. The advantages and limitations of the method were presented in comparison to the common analysis techniques, TGA-FTIR and TGA-MS. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Green strength of zirconium sponge and uranium dioxide powder compacts

    International Nuclear Information System (INIS)

    Balakrishna, Palanki; Murty, B. Narasimha; Sahoo, P.K.; Gopalakrishna, T.

    2008-01-01

    Zirconium metal sponge is compacted into rectangular or cylindrical shapes using hydraulic presses. These shapes are stacked and electron beam welded to form a long electrode suitable for vacuum arc melting and casting into solid ingots. The compact electrodes should be sufficiently strong to prevent breakage in handling as well as during vacuum arc melting. Usually, the welds are strong and the electrode strength is limited by the green strength of the compacts, which constitute the electrode. Green strength is also required in uranium dioxide (UO 2 ) powder compacts, to withstand stresses during de-tensioning after compaction as well as during ejection from the die and for subsequent handling by man and machine. The strengths of zirconium sponge and UO 2 powder compacts have been determined by bending and crushing respectively, and Weibul moduli evaluated. The green density of coarse sponge compact was found to be larger than that from finer sponge. The green density of compacts from lightly attrited UO 2 powder was higher than that from unattrited category, accompanied by an improvement in UO 2 green crushing strength. The factors governing green strength have been examined in the light of published literature and experimental evidence. The methodology and results provide a basis for quality control in metal sponge and ceramic powder compaction in the manufacture of nuclear fuel

  3. Determination of selenoprotein P in human plasma by solid phase extraction and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Bendahl, L.; Sidenius, U.; Gammelgaard, Bente

    2000-01-01

    measured by inductively coupled plasma mass spectrometry (ICP-MS) monitoring the Se-82 isotope. Linear response was observed in the concentration range 0.3-70.8 mu g/l selenium as selenoprotein P with a correlation coefficient of 0.9994. The precision expressed as relative standard deviation was better...... than 2% in this range. The estimated limit of detection was 2 mu g/l and the experimentally verified quantification limit was 5 mu g/l, giving a relative standard deviation less than 2%. (C) 2000 Elsevier Science B.V. All rights reserved...

  4. Physically detached 'compact groups'

    Science.gov (United States)

    Hernquist, Lars; Katz, Neal; Weinberg, David H.

    1995-01-01

    A small fraction of galaxies appear to reside in dense compact groups, whose inferred crossing times are much shorter than a Hubble time. These short crossing times have led to considerable disagreement among researchers attempting to deduce the dynamical state of these systems. In this paper, we suggest that many of the observed groups are not physically bound but are chance projections of galaxies well separated along the line of sight. Unlike earlier similar proposals, ours does not require that the galaxies in the compact group be members of a more diffuse, but physically bound entity. The probability of physically separated galaxies projecting into an apparent compact group is nonnegligible if most galaxies are distributed in thin filaments. We illustrate this general point with a specific example: a simulation of a cold dark matter universe, in which hydrodynamic effects are included to identify galaxies. The simulated galaxy distribution is filamentary and end-on views of these filaments produce apparent galaxy associations that have sizes and velocity dispersions similar to those of observed compact groups. The frequency of such projections is sufficient, in principle, to explain the observed space density of groups in the Hickson catalog. We discuss the implications of our proposal for the formation and evolution of groups and elliptical galaxies. The proposal can be tested by using redshift-independent distance estimators to measure the line-of-sight spatial extent of nearby compact groups.

  5. The Kepler-10 planetary system revisited by HARPS-N: A hot rocky world and a solid Neptune-mass planet

    Energy Technology Data Exchange (ETDEWEB)

    Dumusque, Xavier; Buchhave, Lars A.; Latham, David W.; Charbonneau, David; Dressing, Courtney D.; Gettel, Sara; Lopez-Morales, Mercedes [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Bonomo, Aldo S. [INAF - Osservatorio Astrofisico di Torino, via Osservatorio 20, I-10025 Pino Torinese (Italy); Haywood, Raphaëlle D.; Cameron, Andrew Collier; Horne, Keith [SUPA, School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews Fife KY16 9SS (United Kingdom); Malavolta, Luca [Dipartimento di Fisica e Astronomia " Galileo Galilei," Universita' di Padova, Vicolo dell' Osservatorio 3, I-35122 Padova (Italy); Ségransan, Damien; Pepe, Francesco; Udry, Stéphane [Observatoire Astronomique de l' Université de Genève, 51 ch. des Maillettes, CH-1290 Versoix (Switzerland); Molinari, Emilio; Cosentino, Rosario; Fiorenzano, Aldo F. M.; Harutyunyan, Avet [INAF - Fundacin Galileo Galilei, Rambla Jos Ana Fernandez Prez 7, E-38712 Brea Baja (Spain); Figueira, Pedro, E-mail: xdumusque@cfa.harvard.edu [Centro de Astrofìsica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); and others

    2014-07-10

    Kepler-10b was the first rocky planet detected by the Kepler satellite and confirmed with radial velocity follow-up observations from Keck-HIRES. The mass of the planet was measured with a precision of around 30%, which was insufficient to constrain models of its internal structure and composition in detail. In addition to Kepler-10b, a second planet transiting the same star with a period of 45 days was statistically validated, but the radial velocities were only good enough to set an upper limit of 20 M{sub ⊕} for the mass of Kepler-10c. To improve the precision on the mass for planet b, the HARPS-N Collaboration decided to observe Kepler-10 intensively with the HARPS-N spectrograph on the Telescopio Nazionale Galileo on La Palma. In total, 148 high-quality radial-velocity measurements were obtained over two observing seasons. These new data allow us to improve the precision of the mass determination for Kepler-10b to 15%. With a mass of 3.33 ± 0.49 M{sub ⊕} and an updated radius of 1.47{sub −0.02}{sup +0.03} R{sub ⊕}, Kepler-10b has a density of 5.8 ± 0.8 g cm{sup –3}, very close to the value predicted by models with the same internal structure and composition as the Earth. We were also able to determine a mass for the 45-day period planet Kepler-10c, with an even better precision of 11%. With a mass of 17.2 ± 1.9 M{sub ⊕} and radius of 2.35{sub −0.04}{sup +0.09} R{sub ⊕}, Kepler-10c has a density of 7.1 ± 1.0 g cm{sup –3}. Kepler-10c appears to be the first strong evidence of a class of more massive solid planets with longer orbital periods.

  6. Modeling compaction-induced energy dissipation of granular HMX

    Energy Technology Data Exchange (ETDEWEB)

    Gonthier, K.A. [Lamar Univ., Beaumont, TX (US). Dept. of Mechanical Engineering; Menikoff, R.; Son, S.F.; Asay, B.W. [Los Alamos National Lab., NM (US)

    1998-12-31

    A thermodynamically consistent model is developed for the compaction of granular solids. The model is an extension of the single phase limit of two-phase continuum models used to describe Deflagration-to-Detonation Transition (DDT) experiments. The focus is on the energetics and dissipation of the compaction process. Changes in volume fraction are partitioned into reversible and irreversible components. Unlike conventional DDT models, the model is applicable from the quasi-static to dynamic compaction regimes for elastic, plastic, or brittle materials. When applied to the compaction of granular HMX (a brittle material), the model predicts results commensurate with experiments including stress relaxation, hysteresis, and energy dissipation. The model provides a suitable starting point for the development of thermal energy localization sub-scale models based on compaction-induced dissipation.

  7. Influence of solid particles to a coriolis mass flow metering; Einfluss von Feststoffen in einer Fluessigkeitsstroemung auf die Coriolis-Massemessung

    Energy Technology Data Exchange (ETDEWEB)

    Goeke, J.; Steffensen, E. [Fachhochschule Koeln (Germany). Fakultaet Anlagen-, Energie- und Maschinensysteme

    2006-07-01

    Since more than 15 years coriolis mass flow meters could be regarded as an extraordinary metering system. Those old mechanical principle could be enhanced by application of new electronic technique. Today high precise technologies are available for the rough industrial application, which are often distorted from enviromental influences. Nevertheless there exist situations, which the rapid chance of parameters affect the state of the swinging metering system. And the algorithm could not react in an suggestive manner. This problem occurs for example at a two phase flow. Within this paper we present the reaction of a coriolis massflow meter in a liquid flow with little solid particles. The result show small deviations between the experimental results and the thoretical calculations. (orig.)

  8. Determination and Validation of a Solid-phase Extraction Gas Chromatography-mass Spectrometry for the Quantification of Methadone and Its Principal Metabolite in Human Plasma

    Directory of Open Access Journals (Sweden)

    Fouad Chiadmi

    2015-01-01

    Full Text Available This study aimed to develop a solid-phase extraction gas chromatography-selected ion monitoring-mass spectrometry method for the determination of methadone (MDN and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP in human plasma. The linear response was obtained over the concentration range from 10 to 2000 ng/mL for MDN and EDDP. The absolute recoveries of MDN and EDDP were 95.9%-98.9% and 94.8%-102.4%, with relative standard deviation (RSD ranging from 1.8% to 2.7% and 1.8% to 3.9%, respectively. The intra- and interday precisions were found to be less than 5% for both analytes. The limits of detection of MDN and EDDP were 4 and 5 ng/mL, respectively. The presented method was convenient for therapeutic drug monitoring and pharmacokinetic studies in patients on heroin-assisted MDN therapy.

  9. Solid-Phase Microextraction Coupled to Capillary Atmospheric Pressure Photoionization-Mass Spectrometry for Direct Analysis of Polar and Nonpolar Compounds.

    Science.gov (United States)

    Mirabelli, Mario F; Zenobi, Renato

    2018-04-17

    A novel capillary ionization source based on atmospheric pressure photoionization (cAPPI) was developed and used for the direct interfacing between solid-phase microextraction (SPME) and mass spectrometry (MS). The efficiency of the source was evaluated for direct and dopant-assisted photoionization, analyzing both polar (e.g., triazines and organophosphorus pesticides) and nonpolar (polycyclic aromatic hydrocarbons, PAHs) compounds. The results show that the range of compound polarity, which can be addressed by direct SPME-MS can be substantially extended by using cAPPI, compared to other sensitive techniques like direct analysis in real time (DART) and dielectric barrier discharge ionization (DBDI). The new source delivers a very high sensitivity, down to sub parts-per-trillion (ppt), making it a viable alternative when compared to previously reported and less comprehensive direct approaches.

  10. Characterisation of volatile profiles in 50 native Peruvian chili pepper using solid phase microextraction-gas chromatography mass spectrometry (SPME-GCMS).

    Science.gov (United States)

    Patel, Kirti; Ruiz, Candy; Calderon, Rosa; Marcelo, Mavel; Rojas, Rosario

    2016-11-01

    The volatiles were characterised by headspace solid phase micro extraction (HS-SPME), gas chromatography mass spectrometry (GC-FID/MS). A total of 127 compounds were identified with terpenes (including mono terpenes and sesquiterpenes - a total of 45 compounds), esters (31 compounds) and hydrocarbons (20 compounds) were the predominant volatile compounds. Principal component analysis (PCA) of the volatile compounds yielded 2 significant PC's, which together accounted for 90.3% of the total variance in the data set and the scatter plot generated between PC1 and PC2 successfully segregated the 50 chili pepper samples into 7 groups. Clusters of hydrocarbons, esters, terpenes, aldehyde and ketones formed the major determinants of the difference. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Applications of Solid-Phase Microextraction and Gas Chromatography/Mass Spectrometry (SPME-GC/MS in the Study of Grape and Wine Volatile Compounds

    Directory of Open Access Journals (Sweden)

    Annarita Panighel

    2014-12-01

    Full Text Available Volatile compounds are responsible for the wine “bouquet”, which is perceived by sniffing the headspace of a glass, and of the aroma component (palate-aroma of the overall flavor, which is perceived on drinking. Grape aroma compounds are transferred to the wine and undergo minimal alteration during fermentation (e.g., monoterpenes and methoxypyrazines; others are precursors of aroma compounds which form in winemaking and during wine aging (e.g., glycosidically-bound volatile compounds and C13-norisoprenoids. Headspace solid phase microextraction (HS-SPME is a fast and simple technique which was developed for analysis of volatile compounds. This review describes some SPME methods coupled with gas chromatography/mass spectrometry (GC/MS used to study the grape and wine volatiles.

  12. A headspace solid-phase microextraction procedure coupled with gas chromatography-mass spectrometry for the analysis of volatile polycyclic aromatic hydrocarbons in milk samples

    Energy Technology Data Exchange (ETDEWEB)

    Aguinaga, N.; Campillo, N.; Vinas, P.; Hernandez-Cordoba, M. [University of Murcia, Department of Analytical Chemistry, Faculty of Chemistry, Murcia (Spain)

    2008-06-15

    A sensitive and solvent-free method for the determination of ten polycyclic aromatic hydrocarbons, namely, naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene and chrysene, with up to four aromatic rings, in milk samples using headspace solid-phase microextraction and gas chromatography-mass spectrometry detection has been developed. A polydimethylsiloxane-divinylbenzene fiber was chosen and used at 75 C for 60 min. Detection limits ranging from 0.2 to 5 ng L{sup -1} were attained at a signal-to-noise ratio of 3, depending on the compound and the milk sample under analysis. The proposed method was applied to ten different milk samples and the presence of six of the analytes studied in a skimmed milk with vegetal fiber sample was confirmed. The reliability of the procedure was verified by analyzing two different certified reference materials and by recovery studies. (orig.)

  13. Determination of steroids, caffeine and methylparaben in water using solid phase microextraction-comprehensive two dimensional gas chromatography-time of flight mass spectrometry.

    Science.gov (United States)

    Lima Gomes, Paulo C F; Barnes, Brian B; Santos-Neto, Álvaro J; Lancas, Fernando M; Snow, Nicholas H

    2013-07-19

    Analysis of several emerging contaminants (steroids, caffeine and methylparaben) in water using automated solid-phase microextraction with comprehensive two dimensional gas chromatography coupled to time of flight mass spectrometry (SPME-GCxGC-ToF/MS) is presented. Experimental design was used to determine the best SPME extraction conditions and the steroids were not derivatized prior to injection. SPME-GCxGC-ToF/MS provided linear ranges from 0.6 to 1200μgL(-1) and limits of detection and quantitation from 0.02 to 100μgL(-1). A series of river water samples obtained locally were subjected to analysis. SPME-GCxGC-ToF/MS is readily automated, straightforward and competitive with other methods for low level analysis of emerging contaminants. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Method development for the analysis of 1,4-dioxane in drinking water using solid-phase extraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Grimmett, Paul E; Munch, Jean W

    2009-01-01

    1,4-Dioxane has been identified as a probable human carcinogen and an emerging contaminant in drinking water. The United States Environmental Protection Agency's (U.S. EPA) National Exposure Research Laboratory (NERL) has developed a method for the analysis of 1,4-dioxane in drinking water at ng/L concentrations. The method consists of an activated carbon solid-phase extraction of 500-mL or 100-mL water samples using dichloromethane as the elution solvent. The extracts are analyzed by gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) mode. In the NERL laboratory, recovery of 1,4-dioxane ranged from 94-110% in fortified laboratory reagent water and recoveries of 96-102% were demonstrated for fortified drinking water samples. The relative standard deviations for replicate analyses were less than 6% at concentrations exceeding the minimum reporting level.

  15. Gas chromatographic-mass spectrometric determination of hydrophilic compounds in environmental water by solid-phase extraction with activated carbon fiber felt.

    Science.gov (United States)

    Kawata, K; Ibaraki, T; Tanabe, A; Yagoh, H; Shinoda, A; Suzuki, H; Yasuhara, A

    2001-03-09

    Simple gas chromatographic-mass spectrometric determination of hydrophilic organic compounds in environmental water was developed. A cartridge containing activated carbon fiber felt was made by way of trial and was evaluated for solid-phase extraction of the compounds in water. The hydrophilic compounds investigated were acrylamide, N,N-dimethylacetamide, N,N-dimethylformamide, 1,4-dioxane, furfural, furfuryl alcohol, N-nitrosodiethylamine and N-nitrosodimethylamine. Overall recoveries were good (80-100%) from groundwater and river water. The relative standard deviations ranged from 4.5 to 16% for the target compounds. The minimum detectable concentrations were 0.02 to 0.03 microg/l. This method was successfully applied to several river water samples.

  16. Application of novel activated carbon fiber solid-phase, microextraction to the analysis of chlorinated hydrocarbons in water by gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    Sun Tonghua; Jia Jinping; Fang Nenghu; Wang Yalin

    2005-01-01

    This paper presents a study on the performance of activated carbon fiber (ACF) used as extraction fiber for solid-phase microextraction (SPME) and its application for analysis of chlorinated hydrocarbons in water. By means of evaluating scanning electron microscope (SEM) images, specific surface area, pore volume, pore distribution, and properties of adsorption and desorption, the optimal active concentration of phosphoric acid has been determined. Coupled with gas chromatograph-mass spectrometry (GC-MS), ACF-SPME is suitable for determination chlorinated hydrocarbons in water with headspace. Experimental parameters such as adsorption and desorption conditions were studied. The optimized method has an acceptable linearity, good precision, with R.S.D. values <10% for each compound. Compared with commercial fibers, ACF has many advantages such as better resistance to organic solvents, better endurance to high temperature and longer lifetime

  17. Determination of trace quaternary ammonium surfactants in water by combining solid-phase extraction with surface-assisted laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Chen, Y C; Sun, M C

    2001-01-01

    This study demonstrates the feasibility of combining solid-phase extraction (SPE) with surface-assisted laser desorption/ionization (SALDI) mass spectrometry to determine trace quaternary ammonium surfactants in water. The trace surfactants in water were directly concentrated on the surface of activated carbon sorbent in SPE. The activated carbon sorbent was then mixed with the SALDI liquid for SALDI analysis. No SPE elution procedure was necessary. Experimental results indicate that the surfactants with longer chain alkyl groups exhibit higher sensitivities than those with shorter chain alkyl groups in SPE-SALDI analysis. The detection limit for hexadecyltrimethylammonium bromide is around 10 ppt in SPE-SALDI analysis by sampling 100 mL of aqueous solution, while that of tetradecyltrimethylammonium bromide is about 100 ppt. The detection limit for decyltrimethylammonium bromide and dodecyltrimethylammonium bromide is in the low-ppb range. Copyright 2001 John Wiley & Sons, Ltd.

  18. Rapid screening of selective serotonin re-uptake inhibitors in urine samples using solid-phase microextraction gas chromatography-mass spectrometry.

    Science.gov (United States)

    Salgado-Petinal, Carmen; Lamas, J Pablo; Garcia-Jares, Carmen; Llompart, Maria; Cela, Rafael

    2005-07-01

    In this paper a solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) method is proposed for a rapid analysis of some frequently prescribed selective serotonin re-uptake inhibitors (SSRI)-venlafaxine, fluvoxamine, mirtazapine, fluoxetine, citalopram, and sertraline-in urine samples. The SPME-based method enables simultaneous determination of the target SSRI after simple in-situ derivatization of some of the target compounds. Calibration curves in water and in urine were validated and statistically compared. This revealed the absence of matrix effect and, in consequence, the possibility of quantifying SSRI in urine samples by external water calibration. Intra-day and inter-day precision was satisfactory for all the target compounds (relative standard deviation, RSD, detection limits achieved were detected and tentatively identified.

  19. Determination of Low Concentrations of Acetochlor in Water by Automated Solid-Phase Extraction and Gas Chromatography with Mass-Selective Detection

    Science.gov (United States)

    Lindley, C.E.; Stewart, J.T.; Sandstrom, M.W.

    1996-01-01

    A sensitive and reliable gas chromatographic/mass spectrometric (GC/MS) method for determining acetochlor in environmental water samples was developed. The method involves automated extraction of the herbicide from a filtered 1 L water sample through a C18 solid-phase extraction column, elution from the column with hexane-isopropyl alcohol (3 + 1), and concentration of the extract with nitrogen gas. The herbicide is quantitated by capillary/column GC/MS with selected-ion monitoring of 3 characteristic ions. The single-operator method detection limit for reagent water samples is 0.0015 ??g/L. Mean recoveries ranged from about 92 to 115% for 3 water matrixes fortified at 0.05 and 0.5 ??g/L. Average single-operator precision, over the course of 1 week, was better than 5%.

  20. Direct-immersion solid-phase microextraction coupled to fast gas chromatography mass spectrometry as a purification step for polycyclic aromatic hydrocarbons determination in olive oil.

    Science.gov (United States)

    Purcaro, Giorgia; Picardo, Massimo; Barp, Laura; Moret, Sabrina; Conte, Lanfranco S

    2013-09-13

    The aim of the present work was to optimize a preparation step for polycyclic aromatic hydrocarbons in a fatty extract. Solid-phase microextraction is an easy preparation technique, which allows to minimize solvent consumption and reduce sample manipulation. A Carbopack Z/polydimethylsiloxane fiber, particularly suitable for extraction of planar compounds, was employed to extract polycyclic aromatic hydrocarbons from a hexane solution obtained after a previous extraction with acetonitrile from oil, followed by a liquid-liquid partition between acetonitrile and hexane. The proposed method was a rapid and sensitive solution to reduce the interference of triglycerides saving the column life and avoiding frequent cleaning of the mass spectrometer ion source. Despite the non-quantitative extraction of polycyclic aromatic hydrocarbons from oil using acetonitrile, the signal-to-noise ratio was significantly improved obtaining a limit of detection largely below the performance criteria required by the European Union legislation. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Reproducibility of serum protein profiling by systematic assessment using solid-phase extraction and matrix-assisted laser desorption/ionization mass spectrometry

    DEFF Research Database (Denmark)

    Callesen, Anne K; Christensen, René Depont; Madsen, Jonna S

    2008-01-01

    for serum protein profiling we investigated a range of sample preparation techniques and developed a statistical method based on repeated analyses for evaluation of protein-profiling performance of MALDI MS. Two different solid-phase extraction (SPE) methods were investigated, namely custom......Protein profiling of human serum by matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) is potentially a new diagnostic tool for early detection of human diseases, including cancer. Sample preparation is a key issue in MALDI MS and the analysis of complex samples such as serum......-made microcolumns and commercially available magnetic beads. Using these two methods, nineteen different sample preparation methods for serum profiling by MALDI MS were systematically tested with regard to matrix selection, stationary phase, selectivity, and reproducibility. Microcolumns were tested with regard...

  2. Shear wave velocity measurements for differential diagnosis of solid breast masses: a comparison between virtual touch quantification and virtual touch IQ.

    Science.gov (United States)

    Tozaki, Mitsuhiro; Saito, Masahiro; Benson, John; Fan, Liexiang; Isobe, Sachiko

    2013-12-01

    This study compared the diagnostic performance of two shear wave speed measurement techniques in 81 patients with 83 solid breast lesions. Virtual Touch Quantification, which provides single-point shear wave speed measurement capability (SP-SWS), was compared with Virtual Touch IQ, a new 2-D shear wave imaging technique with multi-point shear wave speed measurement capability (2D-SWS). With SP-SWS, shear wave velocity was measured within the lesion ("internal" value) and the marginal areas ("marginal" value). With 2D-SWS, the highest velocity was measured. The marginal values obtained with the SP-SWS and 2D-SWS methods were significantly higher for malignant lesions and benign lesions, respectively (p breast masses. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  3. Simultaneous Analysis of Simple Coumarins and Furocoumarines in Cigarettes by Solid-Phase Extraction with Gas Chromatography-Mass Spectrometry.

    Science.gov (United States)

    Zheng, Yang; Xu, Xiuli; Yuan, Fei; Yao, Meiyi; Ji, Shunli; Huang, Zhiqiang; Zhang, Feng

    2017-09-01

    A sensitive, high-throughput analytical method based on a GC-MS method was established for the simultaneous quantitative determination of two categories of harmful coumarins: simple coumarins (coumarin, 6-methylcoumarin, 7-methoxycoumarin, 3,4-dihydrocoumarin, and 7-ethoxy-4-methylcoumarin) and furocoumarines (psoralen, 8-methoxypsoralen, 5-methoxypsoralen, and trioxysalen). The nine analytes were extracted with ethyl acetate, purified with Oasis HLB solid-phase extraction (SPE) cartridges, and identified and quantitatively determined by GC-MS in selected-ion monitoring mode. The LODs and LOQs of these compounds were in the ranges of 12.5-21.2 and 41.6-70.0 μg/kg, respectively. Average recoveries for the nine analytes ranged from 72.7 to 86.6% at LOQ, 1.5× LOQ, and 2× LOQ spike levels, with RSDs that were typically lower than 5.1%. The SPE-GC-MS method developed in this study was initially applied to research coumarins in cigarette samples; it proved to be accurate, sensitive, convenient, and practical.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  5. Analysis of macrolide antibiotics in water by magnetic solid-phase extraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Pérez, Rosa Ana; Albero, Beatriz; Férriz, Macarena; Tadeo, José Luis

    2017-11-30

    Macrolides are one of the most commonly used families of antibiotics employed in human and veterinary treatment. These compounds are considered emerging contaminants with potential ecological and human health risks that could be present in surface water. This paper describes the development and application of a simple and efficient extraction procedure for the determination of tilmicosin; erythromycin, tylosin and erythromycin-H 2 O from water samples. Sample extraction was carried out using magnetic solid-phase extraction using oleate functionalized magnetic nanoparticles followed by LC-MS/MS analysis. The effects of several parameters on the extraction efficiency of MLs from water were evaluated. The recovery results obtained were >84% for most of the compounds, except for erytromycin. The LOD and LOQ values ranged from 11.5 to 26ngL -1 and from 34 to 77ngL -1 , respectively. The selected method was applied to monitor these contaminants in water samples from different sources. Tilmicosin and tylosin were not detected in any of the samples, but erythromycin and erythromycin-H 2 O were found in 50% of the surface water samples at levels from

  6. Determination of Bile Acids in Piglet Bile by Solid Phase Extraction and Liquid Chromatography-Electrospray Tandem Mass Spectrometry.

    Science.gov (United States)

    Mi, Si; Lim, David W; Turner, Justine M; Wales, Paul W; Curtis, Jonathan M

    2016-03-01

    An LC/MS/MS-based method was developed for the determination of individual bile acids (BA) and their conjugates in porcine bile samples. The C18-based solid-phase extraction (SPE) procedure was optimized so that all 19 target BA and their glycine and taurine conjugates were collected with high recoveries for standards (89.1-100.2%). Following this, all 19 compounds were separated and quantified in a single 12 min chromatographic run. The method was validated in terms of linearity, sensitivity, accuracy, precision, and recovery. An LOD in the low ppb range with measured precisions in the range of 0.5-9.3% was achieved. The recoveries for all of the 19 analytes in bile samples were all >80%. The validated method was successfully applied to the profiling of BA and their conjugates in the bile from piglets treated with exogenous glucagon-like peptide-2 (GLP-2) in a preclinical model of neonatal parenteral nutrition-associated liver disease (PNALD). The method developed is rapid and could be easily implemented for routine analysis of BA and their conjugates in other biofluids or tissues.

  7. Determination of Lactones in Wines by Headspace Solid-Phase Microextraction and Gas Chromatography Coupled with Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    S. J. Pérez-Olivero

    2014-01-01

    Full Text Available Application of headspace solid-phase microextraction (HS-SPME coupled with high-resolution gas chromatographic (HRGC analysis was studied for determining lactones in wines. Six different SPME fibers were tested, and the influence of different factors such as temperature and time of desorption, ionic strength, time of extraction, content of sugar, ethanol, tannins and anthocyanins, and pH and influence of SO2 were studied. The proposed HS-SPME-GC method is an appropriate technique for the quantitative analysis of γ-butyrolactone, γ-hexalactone, trans-whiskey lactone, γ-octalactone, cis-whiskey lactone, γ-nonalactone, γ-decalactone, δ-decalactone, and γ-undecalactone in wines. Method reproducibility and repeatability ranged between 0.6 and 5.2% for all compounds. Detection limit for γ-butyrolactone was 0.17 mg/L and a few μg/L for the rest of the compounds. The optimized method has been applied to several wine samples.

  8. A new carbon-based magnetic material for the dispersive solid-phase extraction of UV filters from water samples before liquid chromatography-tandem mass spectrometry analysis.

    Science.gov (United States)

    Piovesana, Susy; Capriotti, Anna Laura; Cavaliere, Chiara; La Barbera, Giorgia; Samperi, Roberto; Zenezini Chiozzi, Riccardo; Laganà, Aldo

    2017-07-01

    Magnetic solid-phase extraction is one of the most promising new extraction methods for liquid samples before ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis. Several types of materials, including carbonaceous ones, have been prepared for this purpose. In this paper, for the first time, the preparation, characterization, and sorption capability of Fe 3 O 4 -graphitized carbon black (mGCB) composite toward some compounds of environmental interest were investigated. The synthesized mGCB consisted of micrometric GCB particles with 55 m 2  g -1 surface area bearing some carbonyl and hydroxyl functionalities and the surface partially decorated by Fe 3 O 4 microparticles. The prepared mGCB was firstly tested as an adsorbent for the extraction from surface water of 50 pollutants, including estrogens, perfluoroalkyl compounds, UV filters, and quinolones. The material showed good affinity to many of the tested compounds, except carboxylates and glucoronates; however, some compounds were difficult to desorb. Ten UV filters belonging to the chemical classes of benzophenones and p-aminobenzoates were selected, and parameters were optimized for the extraction of these compounds from surface water before UHPLC-MS/MS determination. Then, the method was validated in terms of linearity, trueness, intra-laboratory precision, and detection and quantification limits. In summary, the method performance (trueness, expressed as analytical recovery, 85-114%; RSD 5-15%) appears suitable for the determination of the selected compounds at the level of 10-100 ng L -1 , with detection limits in the range of 1-5 ng L -1 . Finally, the new method was compared with a published one, based on conventional solid-phase extraction with GCB, showing similar performance in real sample analysis. Graphical Abstract Workflow of the analytical method based on magnetic solid-phase extraction followed by LC-MS/MS determination.

  9. Cooling of hypernuclear compact stars

    Science.gov (United States)

    Raduta, Adriana R.; Sedrakian, Armen; Weber, Fridolin

    2018-04-01

    We study the thermal evolution of hypernuclear compact stars constructed from covariant density functional theory of hypernuclear matter and parametrizations which produce sequences of stars containing two-solar-mass objects. For the input in the simulations, we solve the Bardeen-Cooper-Schrieffer gap equations in the hyperonic sector and obtain the gaps in the spectra of Λ, Ξ0, and Ξ- hyperons. For the models with masses M/M⊙ ≥ 1.5 the neutrino cooling is dominated by hyperonic direct Urca processes in general. In the low-mass stars the (Λp) plus leptons channel is the dominant direct Urca process, whereas for more massive stars the purely hyperonic channels (Σ-Λ) and (Ξ-Λ) are dominant. Hyperonic pairing strongly suppresses the processes on Ξ-s and to a lesser degree on Λs. We find that intermediate-mass 1.5 ≤ M/M⊙ ≤ 1.8 models have surface temperatures which lie within the range inferred from thermally emitting neutron stars, if the hyperonic pairing is taken into account. Most massive models with M/M⊙ ≃ 2 may cool very fast via the direct Urca process through the (Λp) channel because they develop inner cores where the S-wave pairing of Λs and proton is absent.

  10. Electrical properties of the potassium polytitanate compacts

    Energy Technology Data Exchange (ETDEWEB)

    Goffman, V.G.; Gorokhovsky, A.V. [NanoTechProm Ltd., Saratov (Russian Federation); Saratov State Technical University, Saratov (Russian Federation); Kompan, M.M. [Physico-Technical Institute of the Russian Academy of Science, St. Petersburg (Russian Federation); Tretyachenko, E.V.; Telegina, O.S.; Kovnev, A.V. [NanoTechProm Ltd., Saratov (Russian Federation); Saratov State Technical University, Saratov (Russian Federation); Fedorov, F.S., E-mail: fedorov_fs@daad-alumni.de [NanoTechProm Ltd., Saratov (Russian Federation); Saratov State Technical University, Saratov (Russian Federation)

    2014-12-05

    Highlights: • Quasi-static permittivity of potassium polytitanates compacts achieves 10{sup 4}–10{sup 5}. • Observed Maxwell–Wagner polarization attributes to layered structure of polytitanates. • The conductivity varies from 5 × 10{sup −2} to 10{sup −6}–10{sup −7} Sm/m in a wide range of temperatures. - Abstract: Titanates of alkali metals are widely applied materials as they are relatively low in cost and might be easily synthesized. They are utilized as adsorbents, catalysts, solid state electrolytes, superconductors. Here we report our results on electrical properties of the compacted amorphous potassium polytitanates powders. The electrical properties of the compacts were studied by means of complex impedance spectroscopy in a wide range of frequencies at different temperatures using two-electrode configuration. The frequency dependences of conductivity for the investigated potassium polytitanates compacts varies in the range from 5 × 10{sup −2} Sm/m (high frequencies, ion conductivity) up to 10{sup −6}–10{sup −7} Sm/m (low frequencies, electron conductivity) for a wide range of temperatures (19–150 °C). According to the results, at low frequencies quasi-static permittivity of the stabilized PPT compacts achieves high values of 10{sup 4}–10{sup 5}. This might be explained by Maxwell–Wagner polarization attributed to the layered structure of the potassium polytitanates particles containing potassium and hydronium ions together with crystallization water in the interlayer and is very promising for solid state electrolyte applications for moderate temperatures.

  11. Multivariate study of parameters in the determination of pesticide residues in apple by headspace solid phase microextraction coupled to gas chromatography-mass spectrometry using experimental factorial design.

    Science.gov (United States)

    Abdulra'uf, Lukman Bola; Tan, Guan Huat

    2013-12-15

    Solid-phase microextraction (SPME) is a solvent-less sample preparation method which combines sample preparation, isolation, concentration and enrichment into one step. In this study, multivariate strategy was used to determine the significance of the factors affecting the solid phase microextraction of pesticide residues (fenobucarb, diazinon, chlorothalonil and chlorpyrifos) using a randomised factorial design. The interactions and effects of temperature, time and salt addition on the efficiency of the extraction of the pesticide residues were evaluated using 2(3) factorial designs. The analytes were extracted with 100 μm PDMS fibres according to the factorial design matrix and desorbed into a gas chromatography-mass spectrometry detector. The developed method was applied for the analysis of apple samples and the limits of detection were between 0.01 and 0.2 μg kg(-)(1), which were lower than the MRLs for apples. The relative standard deviations (RSD) were between 0.1% and 13.37% with average recovery of 80-105%. The linearity ranges from 0.5-50 μg kg(-)(1) with correlation coefficient greater than 0.99. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Highly selective solid-phase extraction and large volume injection for the robust gas chromatography-mass spectrometric analysis of TCA and TBA in wines.

    Science.gov (United States)

    Insa, S; Anticó, E; Ferreira, V

    2005-09-30

    A reliable solid-phase extraction (SPE) method for the simultaneous determination of 2,4,6-trichloroanisole (TCA) and 2,4,6-tribromoanisole (TBA) in wines has been developed. In the proposed procedure 50 mL of wine are extracted in a 1 mL cartridge filled with 50 mg of LiChrolut EN resins. Most wine volatiles are washed up with 12.5 mL of a water:methanol solution (70%, v/v) containing 1% of NaHCO3. Analytes are further eluted with 0.6 mL of dichloromethane. A 40 microL aliquot of this extract is directly injected into a PTV injector operated in the solvent split mode, and analysed by gas chromatography (GC)-ion trap mass spectrometry using the selected ion storage mode. The solid-phase extraction, including sample volume and rinsing and elution solvents, and the large volume GC injection have been carefully evaluated and optimized. The resulting method is precise (RSD (%) TBA, respectively), robust (the absolute recoveries of both analytes are higher than 80% and consistent wine to wine) and friendly to the GC-MS system (the extract is clean, simple and free from non-volatiles).

  13. Application of solid-phase microextraction with gas chromatography and mass spectrometry for the early detection of active moulds on historical woollen objects.

    Science.gov (United States)

    Sawoszczuk, Tomasz; Syguła-Cholewińska, Justyna; Del Hoyo-Meléndez, Julio M

    2017-02-01

    The goal of this work was to determine the microbial volatile organic compounds emitted by moulds growing on wool in search of particular volatiles mentioned in the literature as indicators of active mould growth. The keratinolytically active fungi were inoculated on two types of media: (1) samples of wool placed on broths, and (2) on broths containing amino acids that are elements of the structure of keratin. All samples were prepared inside 20 mL vials (closed system). In the first case (1) the broths did not contain any sources of organic carbon, nitrogen, or sulfur, i.e. wool was the only nutrient for the moulds. A third type of sample was historical wool prepared in a Petri dish without a broth and inoculated with a keratinolytically active mould (open system). The microbial volatiles emitted by moulds were sampled with the headspace solid-phase microextraction method. Volatiles extracted on solid-phase microextraction fibers were analyzed in a gas chromatography with mass spectrometry system. Qualitative and quantitative analyses of chromatograms were carried out in search of indicators of metabolic activity. The results showed that there are three groups of volatiles that can be used for the detection of active forms of moulds on woollen objects. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. [Determination of deoxynivalenol in grain and its products by solid-phase extraction coupled with high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Huang, Juan; Chen, Guosong; Zhang, Xiaoyan; Shen, Chongyu; Lü, Chen; Wu, Bin; Liu, Yan; Chen, Huilan; Ding, Tao

    2012-11-01

    A method was established for the determination of deoxynivalenol (vomitoxin) in grain and its products based on solid-phase extraction coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The sample was firstly extracted by acetonitrile-water (84:16, v/v). The extract was then cleaned-up by an HLB solid phase extraction cartridge. The separation was carried out on a Phenomenex Kinetex C18 column (100 mm x4. 6 mm, 2.6 microm) with a gradient elution using 0.3% per hundred ammonia solution-acetonitrile as mobile phases. The analysis of deoxynivalenol was performed under electrospray negative ionization mode. The limit of detection (LOD, S/N= 3) and the limit of quantification (LOQ, S/N = 10) were 20 microg/kg and 50 microg/kg, respectively. A good linearity (r > 0.99) was achieved for the target compound over the range of 20-1000 pg/L. The recoveries at the three spiked levels (50, 100, 500 microg/kg) in the blank matrices such as flour, barley, soybean, rice, cornmeal, cassava and wheat, were varied from 75.6% to 111.0% with the relative standard deviations no more than 13. 0%. The method is accurate, efficient, sensitive and practical. The cost of pretreatment is obviously reduced by replacing immunoaffinity columns and Mycosep columns with HLB columns which have the same purification effect.

  15. Multivariate analysis of the volatile components in tobacco based on infrared-assisted extraction coupled to headspace solid-phase microextraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Yang, Yanqin; Pan, Yuanjiang; Zhou, Guojun; Chu, Guohai; Jiang, Jian; Yuan, Kailong; Xia, Qian; Cheng, Changhe

    2016-11-01

    A novel infrared-assisted extraction coupled to headspace solid-phase microextraction followed by gas chromatography with mass spectrometry method has been developed for the rapid determination of the volatile components in tobacco. The optimal extraction conditions for maximizing the extraction efficiency were as follows: 65 μm polydimethylsiloxane-divinylbenzene fiber, extraction time of 20 min, infrared power of 175 W, and distance between the infrared lamp and the headspace vial of 2 cm. Under the optimum conditions, 50 components were found to exist in all ten tobacco samples from different geographical origins. Compared with conventional water-bath heating and nonheating extraction methods, the extraction efficiency of infrared-assisted extraction was greatly improved. Furthermore, multivariate analysis including principal component analysis, hierarchical cluster analysis, and similarity analysis were performed to evaluate the chemical information of these samples and divided them into three classifications, including rich, moderate, and fresh flavors. The above-mentioned classification results were consistent with the sensory evaluation, which was pivotal and meaningful for tobacco discrimination. As a simple, fast, cost-effective, and highly efficient method, the infrared-assisted extraction coupled to headspace solid-phase microextraction technique is powerful and promising for distinguishing the geographical origins of the tobacco samples coupled to suitable chemometrics. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Matrix solid-phase dispersion followed by gas chromatography tandem mass spectrometry for the determination of benzotriazole UV absorbers in sediments.

    Science.gov (United States)

    Carpinteiro, I; Abuín, B; Ramil, M; Rodríguez, I; Cela, R

    2012-01-01

    A cost-effective and low solvent consumption method, based on the matrix solid-phase dispersion (MSPD) technique, for the determination of six benzotriazole UV absorbers in sediments is presented. Sieved samples (0.5 g) were first mixed in a mortar with a solid sorbent and then transferred to a polypropylene syringe containing a layer of clean-up co-sorbent. Analytes were eluted with a suitable solvent and further determined by gas chromatography with tandem mass spectrometry (GC-MS/MS). Under final conditions, diatomaceous earth and silica, deactivated to 10%, were used as inert dispersant and clean-up co-sorbent, respectively. Analytes were recovered using just 5 mL of dichloromethane, and this extract was concentrated and exchanged to 1 mL of isooctane. Further removal of co-extracted sulphur was achieved adding activated copper powder to final extracts, which were stored overnight, before injection in the GC-MS/MS system. The accuracy of the method was assessed with river and marine sediment samples showing different carbon contents and spiked at different concentrations in the range from 40 to 500 ng g(-1). Recoveries varied between 78% and 110% with associated standard deviations below 14%. The limits of quantification of the method stayed between 3 and 15 ng g(-1). Levels of target compounds in sediment samples ranged from not detected up to a maximum of 56 ng g(-1) for Tinuvin 328.

  17. [Determination of 23 antibiotics and 3 β-agonists in livestock drinking water by ultra performance liquid chromatography-tandem mass spectrometry coupled with solid-phase extraction].

    Science.gov (United States)

    Shi, Ao

    2016-02-01

    A method has been developed for the simultaneous determination of 23 antibiotics (four categories) and 3 β-agonists in livestock drinking water using solid-phase extraction and ultra performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI MS/MS). The samples were adjusted pH to 5. 0, added Na2EDTA, enriched and cleaned-up by an HLB solid-phase extraction cartridge. The target compounds were confirmed and quantified by UPLC-ESI MS/MS with external standard method for the anti- biotics and internal standard method for the β-agonists. The recoveries were assessed by using lab tap water as matrix. The average recoveries of the 23 antibiotics and the 3 β-agonists were in the range of 50. 7%-104. 6% and the relative standard deviations (RSDs) were 2. 6%-8. 8% (n= 3). Under the optimal conditions, the calibration curves of the 23 antibiotics and the 3 β-agonists showed good linearity with the correlation coefficients better than 0. 994. The limits of detection (LODs, S/N≥3) ranged from 0. 01-0. 20 ng/L. The developed method was applied to analyze the livestock drinking waters in 36 Beijing intensive livestock farms. The results showed that some antibiotics were detected.

  18. [Determination of fatty acid esters of chloropropanediols in diet samples by gas chromatography-mass spectrometry coupled with solid-supported liquid-liquid extraction].

    Science.gov (United States)

    Gao, Jie; Liu, Qing; Han, Feng; Miao, Hong; Zhao, Yunfeng; Wu, Yongning

    2014-05-01

    To establish a method for the determination of fatty acid esters of 3-monochloropropane-1, 2-diol (3-MCPD) and 2-monochloropropane-1, 3-diol (2-MCPD) in diet samples by gas chromatography-mass spectrometry (GC-MS) with solid-supported liquid-liquid extraction (SLE). Diet samples were ultrasonically extracted by hexane, followed by ester cleavage reaction with sodium methylate in methanol, and then purified by solid-supported liquid-liquid extraction. (SLE) using diatomaceous earth as the sorbent. After derivatization with heptafluorobutyrylimidazole, the analytes were detected by GC-MS and quantified by the deuterated internal standards. The limits of detection (LODs) of 3-MCPD esters and 2-MCPD esters in different diet samples were 0.002 - 0.005 mg/kg and 0.002 - 0.006 mg/kg. The average recoveries of 3-MCPD esters and 2-MCPD esters at the spiking levels of 0.05 and 0.1 mg/kg in the diet samples were in the range of 65.9% - 104.2% and 75.4% - 118.0%, respectively, with the relative standard deviations in the range of 2.2% - 14.2% and 0.8% - .13.9%. The method is simple, accurate and rugged for the determination of fatty acid esters of 3-MCPD and 2-MCPD in diet samples.

  19. Characterization of the Key Aroma Compounds in Proso Millet Wine Using Headspace Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Jingke Liu

    2018-02-01

    Full Text Available The volatile compounds in proso millet wine were extracted by headspace solid-phase microextraction (85 μm polyacrylate (PA, 100 μm polydimethylsiloxane (PDMS, 75 μm Carboxen (CAR/PDMS, and 50/30 μm divinylbenzene (DVB/CAR/PDMS fibers, and analyzed using gas chromatography-mass spectrometry; the odor characteristics and intensities were analyzed by the odor activity value (OAV. Different sample preparation factors were used to optimize this method: sample amount, extraction time, extraction temperature, and content of NaCl. A total of 64 volatile compounds were identified from the wine sample, including 14 esters, seven alcohols, five aldehydes, five ketones, 12 benzene derivatives, 12 hydrocarbons, two terpenes, three phenols, two acids, and two heterocycles. Ethyl benzeneacetate, phenylethyl alcohol, and benzaldehyde were the main volatile compounds found in the samples. According to their OAVs, 14 volatile compounds were determined to be odor-active compounds (OAV > 1, and benzaldehyde, benzeneacetaldehyde, 1-methyl-naphthalene, 2-methyl-naphthalene, and biphenyl were the prominent odor-active compounds (OAV > 50, having a high OAV. Principal component analysis (PCA showed the difference of distribution of the 64 volatile compounds and 14 odor-active compounds with four solid-phase microextraction (SPME fibers.

  20. Determination of Three Organochlorine Pesticides in Aqueous Samples by Solid-Phase Extraction Based on Natural Nano Diatomite in Packed Syringe Coupled to Gas Chromatography-Mass Spectrometry.

    Science.gov (United States)

    Taghani, Abdollah; Goudarzi, Nasser; Bagherian, Ghadamali; Chamjangali, Mansour Arab

    2017-01-01

    A rapid, simple, and sensitive technique is proposed based on a miniaturized solid-phase extraction method named mictroextraction in a packed syringe coupled with gas chromatography-mass spectrometry for the preconcentration and determination of three organochlorine pesticides. These include hexachlorobenzene, heptachlor and aldrine in aqueous samples. For the first time, the natural nano diatomite is used a sorbent. Based on this technique, 6.0 mg of the nano sorbent is inserted in a syringe between two polypropylene frits. The analytes would be adsorbed on the solid phase, and would subsequently be eluted using organic solvents. The influence of some important parameters, such as the solution pH, type and volume of the organic desorption solvent, and amount of sorbent on the extraction efficiency of the selected pesticides, is investigated. The proposed method shows good linearity in the range of 0.1 - 40.0 μg L -1 , and at low limits of detection in the range of 0.02 - 0.13 μg L -1 using the selected ion-monitoring mode. The reproducibility of this method was found to be in the range of 3.5 - 11.1% for the understudied pesticides. In order to evaluate the matrix effect, the developed method is also applied to the preconcentration and determination of the selected pesticides in different water samples.

  1. Evaluation of atmospheric solid analysis probe ionization coupled to ion mobility mass spectrometry for characterization of poly(ether ether ketone) polymers

    Energy Technology Data Exchange (ETDEWEB)

    Cossoul, Emilie; Hubert-Roux, Marie; Sebban, Muriel [Normandie Université, COBRA, UMR6014 and FR3038, Université de Rouen, INSA de Rouen, CNRS, IRCOF, 1 rue Tesnière, 76821 Mont-Saint-Aignan Cedex (France); Churlaud, Florence [Arkema, Centre d’Etude de Recherche et Développement, 27470 Serquigny (France); Oulyadi, Hassan [Normandie Université, COBRA, UMR6014 and FR3038, Université de Rouen, INSA de Rouen, CNRS, IRCOF, 1 rue Tesnière, 76821 Mont-Saint-Aignan Cedex (France); Afonso, Carlos, E-mail: carlos.afonso@univ-rouen.fr [Normandie Université, COBRA, UMR6014 and FR3038, Université de Rouen, INSA de Rouen, CNRS, IRCOF, 1 rue Tesnière, 76821 Mont-Saint-Aignan Cedex (France)

    2015-01-26

    Highlights: • Solvent free approach. • Production of intact small oligomers of PEEK with ASAP ionization. • Comparison of the MS/MS spectra from M{sup +}· and [M + H]{sup +} precursor ions. • Identification of end-groups using tandem mass spectrometry. - Abstract: Recently, the interest of the coupling between atmospheric solid analysis probe (ASAP) and ion mobility–mass spectrometry has been revealed in the field of polymers. This method associates a direct ionization technique with a bi-dimensional separation method. Poly(ether ether ketones) (PEEK) belong to the family of the poly(aryl ether ketones) (PAEK) which are high performance aromatic polymers usually used in aerospace, electronics and nuclear industries. PEEK are important commercial thermoplastics with excellent chemical resistance and good mechanical properties. Because of their low solubility, few structural characterization studies of PEEK have been reported. In mass spectrometry, only MALDI-TOF analyses for polymer synthesis monitoring have been described with the use of strong acids such as sulfuric acid. This work demonstrates that ASAP is particularly efficient for analysis of PEEK in a solvent free approach with the production of intact small oligomers (n ≤ 2). Five types of PEEK oligomers with different end-groups were evidenced. With MALDI-TOF, the same end-groups with almost the same relative abundance were obtained which support the hypothesis that the oligomers detected in ASAP are intact small oligomers and not fragments or pyrolysis products. This is particularly interesting as generally the ASAP analysis of polymers yields pyrolysis products with the loss of end-group information. The end-groups assignments have been confirmed by tandem mass spectrometry (MS/MS) experiments on the M{sup +}· molecular ions, which allowed highlighting some specific neutral or radical losses as well as two diagnostic product ions. Thus, ASAP-IM/MS/MS proves to be a fast and efficient

  2. Rapid determination of six carcinogenic primary aromatic amines in mainstream cigarette smoke by two-dimensional online solid phase extraction combined with liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Bie, Zhenying; Lu, Wei; Zhu, You; Chen, Yusong; Ren, Hubo; Ji, Lishun

    2017-01-27

    A fully automated, rapid, and reliable method for simultaneous determination of six carcinogenic primary aromatic amines (AAs), including o-toluidine (o-TOL), 2, 6-dimethylaniline (2, 6-DMA), o-anisidine (o-ASD), 1-naphthylamine (1-ANP), 2-naphthylamine (2-ANP), and 4-aminobiphenyl (4-ABP), in mainstream cigarette smoke was established. The proposed method was based on two-dimensional online solid phase extraction combined with liquid chromatography tandem mass spectrometry (SPE/LC-MS/MS). The particulate phase of the mainstream cigarette smoke was collected on a Cambridge filter pad and pretreated via ultrasonic extraction with 2% formic acid (FA), while the gas phase was trapped by 2% FA without pretreatment for determination. The two-dimensional online SPE comprised of two cartridges with different absorption characteristics was applied for sample pretreatment. Analysis was performed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) under multiple reaction monitoring mode. Each sample required about 0.5h for solid phase extraction and analysis. The limit of detections (LODs) for six AAs ranged from 0.04 to 0.58ng/cig and recoveries were within 84.5%-122.9%. The relative standard deviations of intra- and inter-day tests for 3R4F reference cigarette were less than 6% and 7%, respectively, while no more than 7% and 8% separately for a type of Virginia cigarette. The proposed method enabled minimum sample pretreatment, full automation, and high throughput with high selectivity, sensitivity, and accuracy. As a part of the validation procedure, fifteen brands of cigarettes were tested by the designed method. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Investigations on the emission of fragrance allergens from scented toys by means of headspace solid-phase microextraction gas chromatography-mass spectrometry.

    Science.gov (United States)

    Masuck, Ines; Hutzler, Christoph; Luch, Andreas

    2010-04-30

    In the revised European toy safety directive 2009/48/EC the application of fragrance allergens in children's toys is restricted. The focus of the present work lies on the instrumental analytics of 13 banned fragrance allergens, as well as on 11 fragrance allergens that require declaration when concentrations surpass 100 microg per gram material. Applying a mixture of ethyl acetate and toluene solid/liquid extraction was performed prior to quantitative analysis of mass contents of fragrances in scented toys. In addition, an easy-to-perform method for the determination of emitted fragrances at 23 degrees C (handling conditions) or at 40 degrees C (worst case scenario) has been worked out to allow for the evaluation of potential risks originating from inhalation of these compounds during handling of or playing with toys. For this purpose a headspace solid-phase microextraction (HS-SPME) technique was developed and coupled to subsequent gas chromatography-mass spectrometry (GC-MS) analysis. Fragrance allergens were adsorbed (extracted) from the gas phase onto an 85 microm polyacrylate fiber while incubating pieces of the scented toys in sealed headspace vials at 23 degrees C and 40 degrees C. Quantification of compounds was performed via external calibration. The newly developed headspace method was subsequently applied to five perfumed toys. As expected, the emission of fragrance allergens from scented toys depends on the temperature and on the content of fragrance allergens present in those samples. In particular at conditions mimicking worst case (40 degrees C), fragrance allergens in toys may pose a risk to children since considerable amounts of compound might be absorbed by lung tissue via breathing of contaminated air. 2010 Elsevier B.V. All rights reserved.

  4. Determination of perfluorinated carboxylic acids in fish fillet by micro-solid phase extraction, followed by liquid chromatography-triple quadrupole mass spectrometry.

    Science.gov (United States)

    Lashgari, Maryam; Lee, Hian Kee

    2014-11-21

    In the current study, a simple, fast and efficient combination of protein precipitation and micro-solid phase extraction (μ-SPE) followed by liquid chromatography-triple quadrupole tandem mass spectrometry (LC-MS/MS) was developed for the determination of perfluorinated carboxylic acids (PFCAs) in fish fillet. Ten PFCAs with different hydrocarbon chain lengths (C5-C14) were analysed simultaneously using this method. Protein precipitation by acetonitrile and μ-SPE by surfactant-incorporated ordered mesoporous silica were applied to the extraction and concentration of the PFCAs as well as for removal of interferences. Determination of the PFCAs was carried out by LC-MS/MS in negative electrospray ionization mode. MS/MS parameters were optimized for multiple reaction monitoring of the analytes. (13)C mass labelled PFOA as a stable-isotopic internal standard, was used for calibration. The detection limits of the method ranged from 0.97 ng/g to 2.7 ng/g, with a relative standard deviation of between 5.4 and 13.5. The recoveries were evaluated for each analyte and were ranged from 77% to 120%. The t-test at 95% confidence level showed that for all the analytes, the relative recoveries did not depend on their concentrations in the explored concentration range. The effect of the matrix on MS signals (suppression or enhancement) was also evaluated. Contamination at low levels was detected for some analytes in the fish samples. The protective role of the polypropylene membrane used in μ-SPE in the elimination of matrix effects was evaluated by parallel experiments in classical dispersive solid phase extraction. The results evidently showed that the polypropylene membrane was significantly effective in reducing matrix effects. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Inhomogeneous compact extra dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Bronnikov, K.A. [Center of Gravity and Fundamental Metrology, VNIIMS, 46 Ozyornaya st., Moscow 119361 (Russian Federation); Budaev, R.I.; Grobov, A.V.; Dmitriev, A.E.; Rubin, Sergey G., E-mail: kb20@yandex.ru, E-mail: buday48@mail.ru, E-mail: alexey.grobov@gmail.com, E-mail: alexdintras@mail.ru, E-mail: sergeirubin@list.ru [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409 Moscow (Russian Federation)

    2017-10-01

    We show that an inhomogeneous compact extra space possesses two necessary features— their existence does not contradict the observable value of the cosmological constant Λ{sub 4} in pure f ( R ) theory, and the extra dimensions are stable relative to the 'radion mode' of perturbations, the only mode considered. For a two-dimensional extra space, both analytical and numerical solutions for the metric are found, able to provide a zero or arbitrarily small Λ{sub 4}. A no-go theorem has also been proved, that maximally symmetric compact extra spaces are inconsistent with 4D Minkowski space in the framework of pure f ( R ) gravity.

  6. Analysis of Mars Analogue Soil Samples Using Solid-Phase Microextraction, Organic Solvent Extraction and Gas Chromatography/Mass Spectrometry

    Science.gov (United States)

    Orzechowska, G. E.; Kidd, R. D.; Foing, B. H.; Kanik, I.; Stoker, C.; Ehrenfreund, P.

    2011-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are robust and abundant molecules in extraterrestrial environments. They are found ubiquitously in the interstellar medium and have been identified in extracts of meteorites collected on Earth. PAHs are important target molecules for planetary exploration missions that investigate the organic inventory of planets, moons and small bodies. This study is part of an interdisciplinary preparation phase to search for organic molecules and life on Mars. We have investigated PAH compounds in desert soils to determine their composition, distribution and stability. Soil samples (Mars analogue soils) were collected at desert areas of Utah in the vicinity of the Mars Desert Research Station (MDRS), in the Arequipa region in Peru and from the Jutland region of Denmark. The aim of this study was to optimize the solid-phase microextraction (SPME) method for fast screening and determination of PAHs in soil samples. This method minimizes sample handling and preserves the chemical integrity of the sample. Complementary liquid extraction was used to obtain information on five- and six-ring PAH compounds. The measured concentrations of PAHs are, in general, very low, ranging from 1 to 60 ng g(sup -1). The texture of soils is mostly sandy loam with few samples being 100% silt. Collected soils are moderately basic with pH values of 8-9 except for the Salten Skov soil, which is slightly acidic. Although the diverse and variable microbial populations of the samples at the sample sites might have affected the levels and variety of PAHs detected, SPME appears to be a rapid, viable field sampling technique with implications for use on planetary missions.

  7. Characterization of the volatile profile of Antarctic bacteria by using solid-phase microextraction-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Romoli, Riccardo; Papaleo, Maria Cristiana; de Pascale, Donatella; Tutino, Maria Luisa; Michaud, Luigi; LoGiudice, Angelina; Fani, Renato; Bartolucci, Gianluca

    2011-10-01

    Bacteria belonging to the Burkholderia cepacia complex (Bcc) are significant pathogens in Cystic Fibrosis (CF) patients and are resistant to a plethora of antibiotics. In this context, microorganisms from Antarctica are interesting because they produce antimicrobial compounds inhibiting the growth of other bacteria. This is particularly true for bacteria isolated from Antarctic sponges. The aim of this work was to characterize a set of Antarctic bacteria for their ability to produce new natural drugs that could be exploited in the control of infections in CF patients by Bcc bacteria. Hence, 11 bacterial strains allocated to different genera (e.g., Pseudoalteromonas, Arthrobacter and Psychrobacter) were tested for their ability to inhibit the growth of 21 Bcc strains and some other human pathogens. All these bacteria completely inhibited the growth of most, if not all, Bcc strains, suggesting a highly specific activity toward Bcc strains. Experimental evidences showed that the antimicrobial compounds are small volatile organic compounds, and are constitutively produced via an unknown pathway. The microbial volatile profile was obtained by SPME-GC-MS within the m/z interval of 40-450. Solid phase micro extraction technique affords the possibility to extract the volatile compounds in head space with a minimal sample perturbation. Principal component analysis and successive cluster discriminant analysis was applied to evaluate the relationships among the volatile organic compounds with the aim of classifying the microorganisms by their volatile profile. These data highlight the potentiality of Antarctic bacteria as novel sources of antibacterial substances to face Bcc infections in CF patients. Copyright © 2011 John Wiley & Sons, Ltd.

  8. A generalized model for compact stars

    Energy Technology Data Exchange (ETDEWEB)

    Aziz, Abdul [Bodai High School (H.S.), Department of Physics, Kolkata, West Bengal (India); Ray, Saibal [Government College of Engineering and Ceramic Technology, Department of Physics, Kolkata, West Bengal (India); Rahaman, Farook [Jadavpur University, Department of Mathematics, Kolkata, West Bengal (India)

    2016-05-15

    By virtue of the maximum entropy principle, we get an Euler-Lagrange equation which is a highly nonlinear differential equation containing the mass function and its derivatives. Solving the equation by a homotopy perturbation method we derive a generalized expression for the mass which is a polynomial function of the radial distance. Using the mass function we find a partially stable configuration and its characteristics. We show that different physical features of the known compact stars, viz. Her X-1, RX J 1856-37, SAX J (SS1), SAX J (SS2), and PSR J 1614-2230, can be explained by the present model. (orig.)

  9. High throughput screening of phenoxy carboxylic acids with dispersive solid phase extraction followed by direct analysis in real time mass spectrometry.

    Science.gov (United States)

    Wang, Jiaqin; Zhu, Jun; Si, Ling; Du, Qi; Li, Hongli; Bi, Wentao; Chen, David Da Yong

    2017-12-15

    A high throughput, low environmental impact methodology for rapid determination of phenoxy carboxylic acids (PCAs) in water samples was developed by combing dispersive solid phase extraction (DSPE) using velvet-like graphitic carbon nitride (V-g-C 3 N 4 ) and direct analysis in real time mass spectrometry (DART-MS). Due to the large surface area and good dispersity of V-g-C 3 N 4 , the DSPE of PCAs in water was completed within 20 s, and the elution of PCAs was accomplished in 20 s as well using methanol. The eluents were then analyzed and quantified using DART ionization source coupled to a high resolution mass spectrometer, where an internal standard was added in the samples. The limit of detection ranged from 0.5 ng L -1 to 2 ng L -1 on the basis of 50 mL water sample; the recovery 79.9-119.1%; and the relative standard deviation 0.23%-9.82% (≥5 replicates). With the ease of use and speed of DART-MS, the whole protocol can complete within mere minutes, including sample preparation, extraction, elution, detection and quantitation. The methodology developed here is simple, fast, sensitive, quantitative, requiring little sample preparation and consuming significantly less toxic organic solvent, which can be used for high throughput screening of PCAs and potentially other contaminants in water. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Mixed-mode solid-phase extraction followed by acetylation and gas chromatography mass spectrometry for the reliable determination of trans-resveratrol in wine samples

    Energy Technology Data Exchange (ETDEWEB)

    Montes, R.; Garcia-Lopez, M. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain); Rodriguez, I., E-mail: isaac.rodriguez@usc.es [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain); Cela, R. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain)

    2010-07-12

    This work presents an advantageous analytical procedure for the accurate determination of free trans-resveratrol in red and white wines. The proposed method involves solid-phase extraction (SPE), acetylation of the analyte in aqueous media and further determination by gas chromatography (GC) with mass spectrometry detection (MS). The use of a mixed-mode SPE sorbent provides an improvement in the selectivity of the extraction step; moreover, the presence of several intense ions in the electron impact mass spectra of its acetyl derivative guarantees the unambiguous identification of trans-resveratrol. Considering a sample intake of 10 mL, the method provides a limit of quantification (LOQ) of 0.8 ng mL{sup -1} and linear responses for concentrations up to 2.5 {mu}g mL{sup -1}, referred to wine samples. The average recovery, estimated with samples fortified at different concentrations in the above range, was 99.6% and the inter-day precision stayed below 8%. Trans-resveratrol levels in the analyzed wines varied from 3.4 to 1810 ng mL{sup -1}. Cis-resveratrol was also found in all samples. In most cases, equal or higher responses were measured for this latter form than for the trans-isomer. The reduced form of resveratrol, dihydro-resveratrol, was systematically identified in red wines.

  11. Semi-automated solid phase extraction method for the mass spectrometric quantification of 12 specific metabolites of organophosphorus pesticides, synthetic pyrethroids, and select herbicides in human urine.

    Science.gov (United States)

    Davis, Mark D; Wade, Erin L; Restrepo, Paula R; Roman-Esteva, William; Bravo, Roberto; Kuklenyik, Peter; Calafat, Antonia M

    2013-06-15

    Organophosphate and pyrethroid insecticides and phenoxyacetic acid herbicides represent important classes of pesticides applied in commercial and residential settings. Interest in assessing the extent of human exposure to these pesticides exists because of their widespread use and their potential adverse health effects. An analytical method for measuring 12 biomarkers of several of these pesticides in urine has been developed. The target analytes were extracted from one milliliter of urine by a semi-automated solid phase extraction technique, separated from each other and from other urinary biomolecules by reversed-phase high performance liquid chromatography, and detected using tandem mass spectrometry with isotope dilution quantitation. This method can be used to measure all the target analytes in one injection with similar repeatability and detection limits of previous methods which required more than one injection. Each step of the procedure was optimized to produce a robust, reproducible, accurate, precise and efficient method. The required selectivity and sensitivity for trace-level analysis (e.g., limits of detection below 0.5ng/mL) was achieved using a narrow diameter analytical column, higher than unit mass resolution for certain analytes, and stable isotope labeled internal standards. The method was applied to the analysis of 55 samples collected from adult anonymous donors with no known exposure to the target pesticides. This efficient and cost-effective method is adequate to handle the large number of samples required for national biomonitoring surveys. Published by Elsevier B.V.

  12. Application of solid phase microextraction followed by liquid chromatography-mass spectrometry in the determination of antibiotic drugs and their metabolites in human whole blood and tissue samples.

    Science.gov (United States)

    Szultka-Mlynska, Malgorzata; Pomastowski, Pawel; Buszewski, Boguslaw

    2018-06-01

    A sensitive, rapid and specific analytical method using high performance liquid chromatography coupled with mass spectrometry (HPLC-QqQ-MS) was developed to determine selected antibiotic drugs and their metabolites (amoxicillin, cefotaxime, ciprofloxacin, clindamycin and metronidazole; amoxycilloic acid, 4-hydroxyphenyl glycyl amoxicillin, desacetyl cefotaxime, 3-desacetyl cefotaxime lactone, ciprofloxacin N-oxide, N-demethylclindamycin, clindamycin sulfoxide, and hydroxy metronidazole) in human whole blood and vascularized tissue after single oral administration. The samples were prepared by solid phase microextraction with C18 fibers (SPME C18 ) and determined on a GRACE analytical C18 column, Vision HT (50 × 2 mm, 1.5 μm) at the flow rate of 0.4 mL min -1 using water and acetonitrile (containing 0.1% formic acid) as the mobile phase. The proposed method was successfully applied in a pharmacokinetic study of the selected antibiotic drugs and their metabolites in real human samples. Additionally, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI/TOF-MS) was used for identification and qualification analysis of the target compounds. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Mixed-mode solid-phase extraction followed by acetylation and gas chromatography mass spectrometry for the reliable determination of trans-resveratrol in wine samples

    International Nuclear Information System (INIS)

    Montes, R.; Garcia-Lopez, M.; Rodriguez, I.; Cela, R.

    2010-01-01

    This work presents an advantageous analytical procedure for the accurate determination of free trans-resveratrol in red and white wines. The proposed method involves solid-phase extraction (SPE), acetylation of the analyte in aqueous media and further determination by gas chromatography (GC) with mass spectrometry detection (MS). The use of a mixed-mode SPE sorbent provides an improvement in the selectivity of the extraction step; moreover, the presence of several intense ions in the electron impact mass spectra of its acetyl derivative guarantees the unambiguous identification of trans-resveratrol. Considering a sample intake of 10 mL, the method provides a limit of quantification (LOQ) of 0.8 ng mL -1 and linear responses for concentrations up to 2.5 μg mL -1 , referred to wine samples. The average recovery, estimated with samples fortified at different concentrations in the above range, was 99.6% and the inter-day precision stayed below 8%. Trans-resveratrol levels in the analyzed wines varied from 3.4 to 1810 ng mL -1 . Cis-resveratrol was also found in all samples. In most cases, equal or higher responses were measured for this latter form than for the trans-isomer. The reduced form of resveratrol, dihydro-resveratrol, was systematically identified in red wines.

  14. Analysis of Digoxin and Metildigoxin in Whole Blood Using Solid-Phase Extraction and Liquid Chromatography Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Paula Melo

    2012-01-01

    Full Text Available A simple and rapid UPLC/MS/MS method has been developed and validated for the analysis of digoxin and metildigoxin in whole blood. Samples were prepared by SPE extraction with Oasis HLB columns. Separation was achieved with an ACQUITY UPLC HSS T3 column (2.1×100; 1.8 μm, at 35°C. The mobile phase consisted of acetonitrile (70% and ammonium formate 5 mM (30%. Total run time was 1.5 min operating at isocratic mode with a flow rate of 0.3 mL/min. Mass spectrometry detection was performed by positive mode electrospray, on the ammonium adducts with two transitions for each analyte and one for the IS (d3-digoxin. The method proved to be specific and linear over the range (0.3–10 ng/mL. This technique also showed high sensitivity with a 0.09 ng/mL LOD and a 0.28 ng/mL LOQ, for both substances. Percentage recovery ranged from 83 to 100% for digoxin and from 62 to 94% for metildigoxin. The intra- and interday precision CV were ≤10%.

  15. Characterization of ceramic powder compacts

    International Nuclear Information System (INIS)

    Yanai, K.; Ishimoto, S.; Kubo, T.; Ito, K.; Ishikawa, T.; Hayashi, H.

    1995-01-01

    UO 2 and Al 2 O 3 powder packing structures in cylindrical powder compacts are observed by scanning electron microscopy using polished cross sections of compacts fixed by low viscosity epoxy resin. Hard aggregates which are not destroyed during powder compaction are observed in some of the UO 2 powder compacts. A technique to measure local density in powder compacts is developed based on counting characteristic X-ray intensity by energy dispersive X-ray analysis (EDX). The local density of the corner portion of the powder compact fabricated by double-acting dry press is higher than that of the inner portion. ((orig.))

  16. Compact Microwave Fourier Spectrum Analyzer

    Science.gov (United States)

    Savchenkov, Anatoliy; Matsko, Andrey; Strekalov, Dmitry

    2009-01-01

    A compact photonic microwave Fourier spectrum analyzer [a Fourier-transform microwave spectrometer, (FTMWS)] with no moving parts has been proposed for use in remote sensing of weak, natural microwave emissions from the surfaces and atmospheres of planets to enable remote analysis and determination of chemical composition and abundances of critical molecular constituents in space. The instrument is based on a Bessel beam (light modes with non-zero angular momenta) fiber-optic elements. It features low power consumption, low mass, and high resolution, without a need for any cryogenics, beyond what is achievable by the current state-of-the-art in space instruments. The instrument can also be used in a wide-band scatterometer mode in active radar systems.

  17. [Monitoring of the residue of fosthiazate in water samples using solid-phase extraction coupled with gas chromatography/mass spectrometry].

    Science.gov (United States)

    Zhu, Jing; Zhou, Xin; Fu, Chunmei; Liu, Sankang; Li, Zhangwan

    2004-11-01

    Solid-phase extraction (SPE) coupled with gas chromatography/mass spectrometry (GC/MS) was used to determine the fosthiazate residue in water samples. The water samples were first filtered through cellulose filters (0.45 microm pore size). A 100 mL volume of filtered water, in which 1 mL of methanol has been added, was then passed through a pre-conditioned 3 cm C18 cartridge at a flow-rate of 1.5 mL/min. Elution was performed by 1 mL of methanol. The eluant was finally dried under reduced pressure for solvent evaporation. The volume was quantitatively adjusted to 0.5 mL with methanol. The analysis was carried out on GC/MS. The mass spectrometer was operated in selected ion monitoring (SIM) mode. According to mass spectrum of fosthiazate, three selected ions at m/z of 126, 195, 283, respectively, were monitored for identification and quantification. High sensitivity and selectivity were achieved by using this method. The limit of detection for fosthiazate in water samples was determined to be 56.4 ng/L. The linearity was demonstrated over a wide range of concentrations covering from 0.282 to 141 microg/L. The recoveries were more than 85.5% and the relative standard deviations for the overall procedure were less than 4.42%. The fosthiazate residue was detected in the water samples from a pool near cropland where fosthiazate was used. The results demonstrate the suitability of the SPE-GC/MS approach for the analysis of fosthiazate in water.

  18. Determination of dextromethorphan in human plasma using pipette tip solid-phase extraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Hasegawa, Chika; Kumazawa, Takeshi; Uchigasaki, Seisaku; Lee, Xiao-Pen; Sato, Keizo; Terada, Masaru; Kurosaki, Kunihiko

    2011-10-01

    Dextromethorphan was extracted from human plasma samples (100 μL) using MonoTip C(18) tips, which are packed with C(18)-bonded monolithic silica gel that is attached to the inside of the tip. The samples, which contained dextromethorphan and trimeprazine as an internal standard (IS), were mixed with 200 μL of distilled water and 50 μL of 1 mol/L glycine-sodium hydroxide buffer (pH 10). The mixture was extracted to the C(18) phase of the tip by 20 sequential aspirating/dispensing cycles using a manual micropipettor. The analytes retained on the C(18) phase were then eluted with methanol by five sequential aspirating/dispensing cycles. The eluate was injected directly into a gas chromatograph and detected by a mass spectrometer with selected ion monitoring in positive electron ionization mode. An Equity-5 fused silica capillary column (30 m × 0.32 mm i.d., film thickness 0.5 μm) gave adequate separation of the dextromethorphan, IS, and impurities. The recoveries of dextromethorphan and the IS spiked into plasma were >87.4%. The regression equation for dextromethorphan showed excellent linearity from 2.5 to 320 ng/mL of plasma, and the limit of detection was 1.25 ng/mL of plasma. The intraday and interday coefficients of variation were less than 10.5% and 14.7%, respectively. The accuracy ranged from 91.9% to 107%. The validated method was successfully used to quantify the plasma concentration of dextromethorphan in a human subject after oral administration of the drug. © Springer-Verlag 2011

  19. The Rapid Formation of Localized Compaction Bands Under Hydrostatic Load Leading to Pore-pressure Transients in Compacting Rocks

    Science.gov (United States)

    Faulkner, D.; Leclere, H.; Bedford, J. D.; Behnsen, J.; Wheeler, J.

    2017-12-01

    Compaction of porous rocks can occur uniformly or within localized deformation bands. The formation of compaction bands and their effects on deformation behaviour are poorly understood. Porosity may be primary and compaction can occur with burial, or it can be produced by metamorphic reactions with a solid volume reduction, that can then undergo collapse. We report results from hydrostatic compaction experiments on porous bassanite (CaSO4.0.5H2O) aggregates. Gypsum (CaSO4.2H2O) is first dehydrated under low effective pressure, 4 MPa, to produce a bassanite aggregate with a porosity of 27%. Compaction is induced by increasing confining pressure at rates from 0.001 MPa/s to 0.02 MPa/s while the sample is maintained at a temperature of 115°C. At slow compaction rates, porosity collapse proceeds smoothly. At higher compaction rates, sudden increases in the pore-fluid pressure occur with a magnitude of 5 MPa. Microstructural investigations using X-ray microtomography and SEM observations show that randomly oriented localized compaction features occur in all samples, where the bulk porosity of 18% outside the band is reduced to 5% inside the band. Previous work on deformation bands has suggested that localized compactive features only form under an elevated differential stress and not under a hydrostatic stress state. The magnitude of the pore-pressure pulses can be explained by the formation of compaction bands. The results indicate that the compaction bands can form by rapid (unstable) propagation across the sample above a critical strain rate, or quasi-statically at low compaction rates without pore-fluid pressure bursts. The absence of pore-fluid pressure bursts at slow compaction rates can be explained by viscous deformation of the bassanite aggregate around the tip of a propagating compaction band, relaxing stress, and promoting stable propagation. Conversely, at higher compaction rates, viscous deformation cannot relax the stress sufficiently and unstable

  20. Determination of 13 endocrine disrupting chemicals in environmental solid samples using microwave-assisted solvent extraction and continuous solid-phase extraction followed by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Azzouz, Abdelmonaim; Ballesteros, Evaristo

    2016-01-01

    Soil can contain large numbers of endocrine disrupting chemicals (EDCs). The varied physicochemical properties of EDCs constitute a great challenge to their determination in this type of environmental matrix. In this work, an analytical method was developed for the simultaneous determination of various classes of EDCs, including parabens, alkylphenols, phenylphenols, bisphenol A, and triclosan, in soils, sediments, and sewage sludge. The method uses microwave-assisted extraction (MAE) in combination with continuous solid-phase extraction for determination by gas chromatography-mass spectrometry. A systematic comparison of the MAE results with those of ultrasound-assisted and Soxhlet extraction showed MAE to provide the highest extraction efficiency (close to 100%) in the shortest extraction time (3 min). The proposed method provides a linear response over the range 2.0 - 5000 ng kg(-1) and features limits of detection from 0.5 to 4.5 ng kg(-1) depending on the properties of the EDC. The method was successfully applied to the determination of target compounds in agricultural soils, pond and river sediments, and sewage sludge. The sewage sludge samples were found to contain all target compounds except benzylparaben at concentration levels from 36 to 164 ng kg(-1). By contrast, the other types of samples contained fewer EDCs and at lower concentrations (5.6 - 84 ng kg(-1)).

  1. Can laser-ionisation time-of-flight mass spectrometry be a promising alternative to laser ablation/inductively-coupled plasma mass spectrometry and glow discharge mass spectrometry for the elemental analysis of solids?

    NARCIS (Netherlands)

    Sysoev, AA; Sysoev, AA

    2002-01-01

    At the beginning of the age of laser-ionisation mass spectrometry (LIMS) increasing numbers of publications were observed. However, later the method began to run into obstacles associated with poor reproducibility of analysis and large variations in elemental sensitivities so that the wide interest

  2. Liquid chromatography mass spectrometry determination of perfluoroalkyl acids in environmental solid extracts after phospholipid removal and on-line turbulent flow chromatography purification.

    Science.gov (United States)

    Mazzoni, M; Polesello, S; Rusconi, M; Valsecchi, S

    2016-07-01

    An on-line TFC (Turbulent Flow Chromatography) clean up procedures coupled with UHPLC-MS/MS (Ultra High Performance Liquid Chromatography Mass Spectrometry) multi-residue method was developed for the simultaneous determination of 8 perfluroalkyl carboxylic acids (PFCA, from 5 to 12 carbon atoms) and 3 perfluoroalkyl sulfonic acids (PFSA, from 4 to 8 carbon atoms) in environmental solid matrices. Fast sample preparation procedure was based on a sonication-assisted extraction with acetonitrile. Phospholipids in biological samples were fully removed by an off-line SPE purification before injection, using HybridSPE(®) Phospholipid Ultra cartridges. The development of the on-line TFC clean-up procedure regarded the choice of the stationary phase, the optimization of the mobile phase composition, flow rate and injected volume. The validation of the optimized method included the evaluation of matrix effects, accuracy and reproducibility. Signal suppression in the analysis of fortified extracts ranged from 1 to 60%, and this problem was overcome by using isotopic dilution. Since no certified reference materials were available for PFAS in these matrices, accuracy was evaluated by recoveries on spiked clam samples which were 98-133% for PFCAs and 40-60% for PFSAs. MLDs and MLQs ranged from 0.03 to 0.3ngg(-1) wet weight and from 0.1 to 0.9ngg(-1) wet weight respectively. Repeatability (intra-day precision) and reproducibility (inter-day precision) showed RSD from 3 to 13% and from 4 to 27% respectively. Validated on-line TFC/UHPLC-MS/MS method has been applied for the determination of perfluoroalkyl acids in different solid matrices (sediment, fish, bivalves and bird yolk). Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Cork as a new (green) coating for solid-phase microextraction: Determination of polycyclic aromatic hydrocarbons in water samples by gas chromatography–mass spectrometry

    International Nuclear Information System (INIS)

    Dias, Adriana Neves; Simão, Vanessa; Merib, Josias; Carasek, Eduardo

    2013-01-01

    Highlights: ► Cork as a new coating for solid-phase microextraction was proposed. ► Good results were achieved, demonstrating the applicability of the cork as coating for SPME. ► The efficiency of cork fiber was very similar to commercially available fibers. -- Abstract: A new fiber for solid-phase microextraction (SPME) was prepared employing cork as a coating. The morphology and composition of the cork fiber was evaluated by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), respectively. The proposed fiber was used for the determination of polycyclic aromatic hydrocarbons (PAHs) in river water samples by gas chromatography–selected ion monitoring–mass spectrometry (GC–SIM–MS). A central composite design was used for optimization of the variables involved in the extraction of PAHs from water samples. The optimal extraction conditions were extraction time and temperature of 60 min and 80 °C, respectively. The detection and quantification limits were 0.03 and 0.1 μg L −1 , respectively. The recovery values were between 70.2 and 103.2% and the RSD was ≤15.7 (n = 3). The linear range was 0.1–10 μg L −1 with r ≥ 0.96 and the fiber-to-fiber reproducibility showed RSD ≤ 18.6% (n = 5). The efficiency of the cork fiber was compared with commercially available fibers and good results were achieved, demonstrating the applicability and great potential of cork as a coating for SPME

  4. Determination of bisphenols in beverages by mixed-mode solid-phase extraction and liquid chromatography coupled to tandem mass spectrometry.

    Science.gov (United States)

    Regueiro, Jorge; Wenzl, Thomas

    2015-11-27

    Facing growing restrictions on the use of bisphenol A in food contact materials, several bisphenol analogs are arising as major alternatives to replace this chemical in most of its applications. This work reports a simple and robust method based on mixed-mode solid-phase extraction and stable-isotope dilution liquid chromatography-tandem mass spectrometry for the analysis of bisphenol A and its main analogs - bisphenol S, 4,4'-sulfonylbis(2-methylphenol), bisphenol F, bisphenol E, bisphenol B, bisphenol Z, bisphenol AF, bisphenol AP, tetrabromobisphenol A and bisphenol P - in alcoholic and non-alcoholic beverages. Mixed-mode solid-phase extraction, combining cationic exchange and reversed-phase mechanisms, was optimized to provide a selective extraction and purification of the target analytes. Derivatization of bisphenols with pyridine-3-sulfonyl chloride allowed increasing their ionization efficiency by electrospray ionization. Validation of the proposed method was performed in terms of selectivity, matrix effects, linearity, precision, measurement uncertainty, trueness and limits of detection. Satisfactory repeatability and intermediate precision were obtained; the related relative standard deviations were ≤9% and ≤12%, respectively. The relative expanded uncertainty (k=2) was below 20% for all bisphenol analogs and the trueness of the method was demonstrated by recovery experiments. Limits of detection (LOD) ranged from 1.6ngL(-1) to 27.9ngL(-1) for all compounds. Finally, several canned and non-canned beverages were analyzed to demonstrate the applicability of the method. Only bisphenol A and three bisphenol F isomers were detected in any of the samples. Bisphenol A concentration ranged from beverages, at concentration levels up to 0.12 and 0.51μgL(-1), respectively. Copyright © 2015. Published by Elsevier B.V.

  5. Determination of antibiotic residues in southern Baltic Sea sediments using tandem solid-phase extraction and liquid chromatography coupled with tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Grzegorz Siedlewicz

    2016-07-01

    Full Text Available The main objective of this study was to adapt analytical procedures for determining antibiotic residues in solid and aquatic samples to marine sediments and to investigate the occurrence of 9 sulfonamides, trimethoprim and 2 quinolones in southern Baltic Sea sediments. The analytical procedure was applied to sediment samples characterized as sand and silty sand. The validation results showed that a sensitive and efficient method applying tandem solid-phase extraction (SPE and liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS was obtained. Analytes were determined in the lower ng g−1 range with good accuracy and precision. The proposed analytical procedure was applied to the analysis of 13 sediment samples collected from the Baltic Sea along the Polish coast. Concentrations of antibiotic residues in environmental samples were calculated based on external matrix-matched calibration. Residues of nine out of twelve of the above antibiotics were detected in sediment samples in a concentrations of up to 419.2 ng g−1 d.w. (dry weight. Sulfamethoxazole and sulfachloropyridazine were the most frequently detected compounds (58% of the analyzed samples. The occurrence frequency of trimethoprim was 42% and it was always detected simultaneously with sulfamethoxazole. Preliminary studies on the spatial distribution of the analyzed antibiotics indicate a high level of antibiotics occurring in the Pomeranian Bay and close to the mouths of Polish rivers. The study is the first one to demonstrate the occurrence of antibiotic residues in sediments of the Polish coastal area. The obtained results suggest that sediment can be an important secondary source of antibiotic residues in the marine environment.

  6. Development and optimization of a solid-phase microextraction gas chromatography-tandem mass spectrometry methodology to analyse ultraviolet filters in beach sand.

    Science.gov (United States)

    Vila, Marlene; Llompart, Maria; Garcia-Jares, Carmen; Homem, Vera; Dagnac, Thierry

    2018-06-06

    A methodology based on solid-phase microextraction (SPME) followed by gas chromatography-tandem mass spectrometry (GC-MS/MS) has been developed for the simultaneous analysis of eleven multiclass ultraviolet (UV) filters in beach sand. To the best of our knowledge, this is the first time that this extraction technique is applied to the analysis of UV filters in sand samples, and in other kind of environmental solid samples. Main extraction parameters such as the fibre coating, the amount of sample, the addition of salt, the volume of water added to the sand, and the temperature were optimized. An experimental design approach was implemented in order to find out the most favourable conditions. The final conditions consisted of adding 1 mL of water to 1 g of sample followed by the headspace SPME for 20 min at 100 °C, using PDMS/DVB as fibre coating. The SPME-GC-MS/MS method was validated in terms of linearity, accuracy, limits of detection and quantification, and precision. Recovery studies were also performed at three concentration levels in real Atlantic and Mediterranean sand samples. The recoveries were generally above 85% and relative standard deviations below 11%. The limits of detection were in the pg g -1 level. The validated methodology was successfully applied to the analysis of real sand samples collected from Atlantic Ocean beaches in the Northwest coast of Spain and Portugal, Canary Islands (Spain), and from Mediterranean Sea beaches in Mallorca Island (Spain). The most frequently found UV filters were ethylhexyl salicylate (EHS), homosalate (HMS), 4-methylbenzylidene camphor (4MBC), 2-ethylhexyl methoxycinnamate (2EHMC) and octocrylene (OCR), with concentrations up to 670 ng g -1 . Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Determination of selected UV filters in indoor dust by matrix solid-phase dispersion and gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Negreira, N; Rodríguez, I; Rubí, E; Cela, R

    2009-07-31

    A simple, inexpensive sample preparation procedure, based on the matrix solid-phase dispersion (MSPD) technique, for the determination of six UV filters: 2-ethylhexyl salicylate (EHS), 3,3,5-trimethylcyclohexyl salicylate (Homosalate, HMS), 3-(4-methylbenzylidene) camphor (4-MBC), isoamyl-p-methoxycinnamate (IAMC), 2-ethylhexyl-p-methoxycinnamate (EHMC) and octocrylene (OCR), in dust from indoor environments is presented and the influence of several operational parameters on the extraction performance discussed. Under the final working conditions, sieved samples (0.5 g) were mixed with the same amount of anhydrous sodium sulphate and dispersed with 2 g of octadecyl bonded silica (C18) in a mortar with a pestle. This blend was transferred to a polypropylene solid-phase extraction cartridge containing 2 g of activated silica, as the clean-up co-sorbent. The cartridge was first rinsed with 5 mL of n-hexane and the analytes were then recovered with 4 mL of acetonitrile. This extract was adjusted to 1 mL, filtered and the compounds were determined by gas chromatography combined with tandem mass spectrometry (GC-MS/MS). Recoveries for samples spiked at two different concentrations ranged between 77% and 99%, and the limits of quantification (LOQs) of the method between 10 and 40 ng g(-1). Analysis of settled dust from different indoor areas, including private flats, public buildings and vehicle cabins, showed that EHMC and OCR were ubiquitous in this matrix, with maximum concentrations of 15 and 41 microg g(-1), respectively. Both UV filters were also quantified in dust reference material SRM 2585 for first time. EHS, 4-MBC and IAMC were detected in some of the analyzed samples, although at lower concentrations than EHMC and OCR.

  8. Ion-exchange solid-phase extraction combined with liquid chromatography-tandem mass spectrometry for the determination of veterinary drugs in organic fertilizers.

    Science.gov (United States)

    Zhao, Zhiyong; Zhang, Yanmei; Xuan, Yanfang; Song, Wei; Si, Wenshuai; Zhao, Zhihui; Rao, Qinxiong

    2016-06-01

    The analysis of veterinary drugs in organic fertilizers is crucial for an assessment of potential risks to soil microbial communities and human health. We develop a robust and sensitive method to quantitatively determine 19 veterinary drugs (amantadine, sulfonamides and fluoroquinolones) in organic fertilizers. The method involved a simple solid-liquid extraction step using the combination of acetonitrile and McIlvaine buffer as extraction solvent, followed by cleanup with a solid-phase extraction cartridge containing polymeric mixed-mode anion-exchange sorbents. Ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was used to separate and detect target analytes. We particularly focused on the optimization of sample clean-up step: different diluents and dilution factors were tested. The developed method was validated in terms of linearity, recovery, precision, sensitivity and specificity. The recoveries of all the drugs ranged from 70.9% to 112.7% at three concentration levels, with the intra-day and inter-day relative standard deviation lower than 15.7%. The limits of quantification were between 1.0 and 10.0μg/kg for all the drugs. Matrix effect was minimized by matrix-matched calibration curves. The analytical method was successfully applied for the survey of veterinary drugs contamination in 20 compost samples. The results indicated that fluoroquinolones had higher incidence rate and mean concentration levels ranging from 31.9 to 308.7μg/kg compared with other drugs. We expect the method will provide the basis for risk assessment of veterinary drugs in organic fertilizers. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Weakly compact operators and interpolation

    OpenAIRE

    Maligranda, Lech

    1992-01-01

    The class of weakly compact operators is, as well as the class of compact operators, a fundamental operator ideal. They were investigated strongly in the last twenty years. In this survey, we have collected and ordered some of this (partly very new) knowledge. We have also included some comments, remarks and examples. The class of weakly compact operators is, as well as the class of compact operators, a fundamental operator ideal. They were investigated strongly in the last twenty years. I...

  10. Diffusion bonding in compact heat exchangers

    International Nuclear Information System (INIS)

    Southall, David

    2009-01-01

    Heatric's diffusion bonding process is a solid-state joining technology that produces strong, compact, all-metal heat exchanger cores. Diffusion bonding allows for a large quantity of joints to be made in geometries that would normally be inaccessible for conventional welding techniques. Since Heatric's diffusion bonding process uses no interlayer or braze alloy, the resulting heat exchanger core has consistent chemistry throughout and, under carefully controlled conditions, a return to parent metal strength can be reached. This paper will provide an overview of the diffusion bonding process and its origins, and also its application to compact heat exchanger construction. The paper will then discuss recent work that has been done to compare mechanical properties of Heatric's diffusion bonded material with material that has been conventionally welded, as well as with material tested in the as-received condition. (author)

  11. Torrefaction Processing for Human Solid Waste Management

    Science.gov (United States)

    Serio, Michael A.; Cosgrove, Joseph E.; Wójtowicz, Marek A.; Stapleton, Thomas J.; Nalette, Tim A.; Ewert, Michael K.; Lee, Jeffrey; Fisher, John

    2016-01-01

    This study involved a torrefaction (mild pyrolysis) processing approach that could be used to sterilize feces and produce a stable, odor-free solid product that can be stored or recycled, and also to simultaneously recover moisture. It was demonstrated that mild heating (200-250 C) in nitrogen or air was adequate for torrefaction of a fecal simulant and an analog of human solid waste (canine feces). The net result was a nearly undetectable odor (for the canine feces), complete recovery of moisture, some additional water production, a modest reduction of the dry solid mass, and the production of small amounts of gas and liquid. The liquid product is mainly water, with a small Total Organic Carbon content. The amount of solid vs gas plus liquid products can be controlled by adjusting the torrefaction conditions (final temperature, holding time), and the current work has shown that the benefits of torrefaction could be achieved in a low temperature range (< 250 C). These temperatures are compatible with the PTFE bag materials historically used by NASA for fecal waste containment and will reduce the energy consumption of the process. The solid product was a dry material that did not support bacterial growth and was hydrophobic relative to the starting material. In the case of canine feces, the solid product was a mechanically friable material that could be easily compacted to a significantly smaller volume (approx. 50%). The proposed Torrefaction Processing Unit (TPU) would be designed to be compatible with the Universal Waste Management System (UWMS), now under development by NASA. A stand-alone TPU could be used to treat the canister from the UWMS, along with other types of wet solid wastes, with either conventional or microwave heating. Over time, a more complete integration of the TPU and the UWMS could be achieved, but will require design changes in both units.

  12. Strange exotic states and compact stars

    International Nuclear Information System (INIS)

    Sagert, Irina; Wietoska, Mirjam; Schaffner-Bielich, Juergen

    2006-01-01

    We discuss the possible appearance of strange exotic multi-quark states in the interiors of neutron stars and signals for the existence of strange quark matter in the cores of compact stars. We show how the in-medium properties of possible pentaquark states are constrained by pulsar mass measurements. The possibility of generating the observed large pulsar kick velocities by asymmetric emission of neutrinos from strange quark matter in magnetic fields is outlined

  13. Determination of chlorophenols in landfill leachate using headspace sampling with ionic liquid-coated solid-phase microextraction fibers combined with gas chromatography–mass spectrometry

    International Nuclear Information System (INIS)

    Ho, Tse-Tsung; Chen, Chung-Yu; Li Zuguang; Yang, Thomas Ching-Cherng; Lee, Maw-Rong

    2012-01-01

    Highlights: ► Ionic liquid (IL), ([C 4 MIM][PF 6 ]), was rapid synthesized by microwave radiation. ► Trace chlorophenols in landfill leachate were extract by SPME coated IL. ► The IL-coated SPME-GC/MS method is low-cost, solvent-free and sensitive. - Abstract: A new microextraction technique based on ionic liquid solid-phase microextraction (IL-SPME) was developed for determination of trace chlorophenols (CPs) in landfill leachate. The synthesized ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ([C 4 MIM][PF 6 ]), was coated onto the spent fiber of SPME for extraction of trace CPs. After extraction, the absorbed analytes were desorbed and quantified using gas chromatography–mass spectrometry (GC/MS). The term of the proposed method is as ionic liquid-coated of solid-phase microextraction combined with gas chromatography–mass spectrometry (IL-SPME-GC/MS). No carryover effect was found, and every laboratory-made ionic liquids-coated-fiber could be used for extraction at least eighty times without degradation of efficiency. The chlorophenols studied were 2,4-dichlorophenol (2,4-DP), 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP), and pentachlorophenol (PCP). The best results of chlorophenols analysis were obtained with landfill leachate at pH 2, headspace extraction for 4 min, and thermal desorption with the gas chromatograph injector at 240 °C for 4 min. Linearity was observed from 0.1 to 1000 μg L −1 with relative standard deviations (RSD) less than 7% and recoveries were over 87%. The limit of detection (LOD) for pentachlorophenol was 0.008 μg L −1 . The proposed method was tested by analyzing landfill leachate from a sewage farm. The concentrations of chlorophenols were detected to range from 1.1 to 1.4 μg L −1 . The results demonstrate that the IL-SPME-GC/MS method is highly effective in analyzing trace chlorophenols in landfill leachate.

  14. Determination of chlorophenols in landfill leachate using headspace sampling with ionic liquid-coated solid-phase microextraction fibers combined with gas chromatography-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Tse-Tsung; Chen, Chung-Yu [Department of Chemistry, National Chung Hsing University, Taichung 40227, Taiwan (China); Li Zuguang [Department of Chemistry, National Chung Hsing University, Taichung 40227, Taiwan (China); College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310014, Zhejiang (China); Yang, Thomas Ching-Cherng [Department of Chemistry, National Kaohsiung Normal University, Kaohsiung 82444, Taiwan (China); Lee, Maw-Rong, E-mail: mrlee@dragon.nchu.edu.tw [Department of Chemistry, National Chung Hsing University, Taichung 40227, Taiwan (China)

    2012-01-27

    Highlights: Black-Right-Pointing-Pointer Ionic liquid (IL), ([C{sub 4}MIM][PF{sub 6}]), was rapid synthesized by microwave radiation. Black-Right-Pointing-Pointer Trace chlorophenols in landfill leachate were extract by SPME coated IL. Black-Right-Pointing-Pointer The IL-coated SPME-GC/MS method is low-cost, solvent-free and sensitive. - Abstract: A new microextraction technique based on ionic liquid solid-phase microextraction (IL-SPME) was developed for determination of trace chlorophenols (CPs) in landfill leachate. The synthesized ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ([C{sub 4}MIM][PF{sub 6}]), was coated onto the spent fiber of SPME for extraction of trace CPs. After extraction, the absorbed analytes were desorbed and quantified using gas chromatography-mass spectrometry (GC/MS). The term of the proposed method is as ionic liquid-coated of solid-phase microextraction combined with gas chromatography-mass spectrometry (IL-SPME-GC/MS). No carryover effect was found, and every laboratory-made ionic liquids-coated-fiber could be used for extraction at least eighty times without degradation of efficiency. The chlorophenols studied were 2,4-dichlorophenol (2,4-DP), 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP), and pentachlorophenol (PCP). The best results of chlorophenols analysis were obtained with landfill leachate at pH 2, headspace extraction for 4 min, and thermal desorption with the gas chromatograph injector at 240 Degree-Sign C for 4 min. Linearity was observed from 0.1 to 1000 {mu}g L{sup -1} with relative standard deviations (RSD) less than 7% and recoveries were over 87%. The limit of detection (LOD) for pentachlorophenol was 0.008 {mu}g L{sup -1}. The proposed method was tested by analyzing landfill leachate from a sewage farm. The concentrations of chlorophenols were detected to range from 1.1 to 1.4 {mu}g L{sup -1}. The results demonstrate that the IL-SPME-GC/MS method is highly effective in

  15. Liquid chromatography with tandem mass spectrometry for the determination of flufenoxuron in blood using automatic solid phase extraction and its application to a fatal case of flufenoxuron poisoning.

    Science.gov (United States)

    Rhee, Jongsook; Cho, Byungsuk; Lee, Juseon; Moon, Sungmin; Yum, Hyesun

    2015-12-01

    A liquid chromatography/tandem mass spectrometry method with solid phase extraction for the detection and the quantitation of flufenoxuron in an aliquot of blood was developed and validated. Flufenoxuron belongs to a benzoylurea insecticide and is the active ingredient of Cascade™. The analyte in postmortem specimens was extracted by solid-phase extraction with Bond Elut Certify cartridge. After the elution layer was evaporated, the residue was reconstituted with 70% methanol for LC/MS/MS analysis. Separations were carried out on a Synergi(®) 2.5u Fusion-RP 100 A column with column temperature kept at 40 °C at a flow rate of 0.4 mL/min. The mobile phase was composed of 5mM ammonium formate in 10% methanol and 5 mM ammonium formate in 90% methanol using gradient elution. A triple quadruple mass spectrometer equipped with an electrospray ionization source operated in a positive ion mode with selective reaction monitoring mode. Atrazine-d5 was used as internal standard. The assay was linear over 0.02-1.0 mg/L (r(2)=0.999). Limit of detection (LOD) and limit of quantitation (LOQ) in blood were 0.009 mg/L (S/N=3) and 0.02 mg/L (S/N=10), respectively. The accuracy and the precision were toxicology laboratory guidelines. Relative recoveries with 0.02, 0.1 and 1.0mg/L (in blood) were 112.3%, 101.2% and 111.0% (n=5), respectively. The developed method was applied in forensic toxicology to determine flufenoxuron in postmortem specimens in a fatal case of flufenoxuron intoxication in a 48-year-old-man who was found dead on bed in a small room after vomiting on the floor. The postmortem heart blood, peripheral blood and gastric contents were analyzed for flufenoxuron with the result of 6.3 mg/L in heart blood, 3.2 mg/L in peripheral blood and 30.6 mg/kg in gastric contents, respectively. The concentration ratio of the heart/peripheral blood of flufenoxuron was 2.0, and the ratio of gastric contents/peripheral blood was 9.4, suggesting possible postmortem redistribution and

  16. Compact stellarators as reactors

    International Nuclear Information System (INIS)

    Lyon, J.F.; Valanju, P.; Zarnstorff, M.C.; Hirshman, S.; Spong, D.A.; Strickler, D.; Williamson, D.E.; Ware, A.

    2001-01-01

    Two types of compact stellarators are examined as reactors: two- and three-field-period (M=2 and 3) quasi-axisymmetric devices with volume-average =4-5% and M=2 and 3 quasi-poloidal devices with =10-15%. These low-aspect-ratio stellarator-tokamak hybrids differ from conventional stellarators in their use of the plasma-generated bootstrap current to supplement the poloidal field from external coils. Using the ARIES-AT model with B max =12T on the coils gives Compact Stellarator reactors with R=7.3-8.2m, a factor of 2-3 smaller R than other stellarator reactors for the same assumptions, and neutron wall loadings up to 3.7MWm -2 . (author)

  17. Compact torsatron reactors

    International Nuclear Information System (INIS)

    Lyon, J.F.; Carreras, B.A.; Lynch, V.E.; Tolliver, J.S.; Sviatoslavsky, I.N.

    1988-05-01

    Low-aspect-ratio torsatron configurations could lead to compact stellarator reactors with R 0 = 8--11m, roughly one-half to one-third the size of more conventional stellarator reactor designs. Minimum-size torsatron reactors are found using various assumptions. Their size is relatively insensitive to the choice of the conductor parameters and depends mostly on geometrical constraints. The smallest size is obtained by eliminating the tritium breeding blanket under the helical winding on the inboard side and by reducing the radial depth of the superconducting coil. Engineering design issues and reactor performance are examined for three examples to illustrate the feasibility of this approach for compact reactors and for a medium-size (R 0 ≅ 4 m,/bar a/ /approx lt/ 1 m) copper-coil ignition experiment. 26 refs., 11 figs., 7 tabs

  18. Compact Spreader Schemes

    Energy Technology Data Exchange (ETDEWEB)

    Placidi, M.; Jung, J. -Y.; Ratti, A.; Sun, C.

    2014-07-25

    This paper describes beam distribution schemes adopting a novel implementation based on low amplitude vertical deflections combined with horizontal ones generated by Lambertson-type septum magnets. This scheme offers substantial compactness in the longitudinal layouts of the beam lines and increased flexibility for beam delivery of multiple beam lines on a shot-to-shot basis. Fast kickers (FK) or transverse electric field RF Deflectors (RFD) provide the low amplitude deflections. Initially proposed at the Stanford Linear Accelerator Center (SLAC) as tools for beam diagnostics and more recently adopted for multiline beam pattern schemes, RFDs offer repetition capabilities and a likely better amplitude reproducibility when compared to FKs, which, in turn, offer more modest financial involvements both in construction and operation. Both solutions represent an ideal approach for the design of compact beam distribution systems resulting in space and cost savings while preserving flexibility and beam quality.

  19. Compact fusion reactors

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    Fusion research is currently to a large extent focused on tokamak (ITER) and inertial confinement (NIF) research. In addition to these large international or national efforts there are private companies performing fusion research using much smaller devices than ITER or NIF. The attempt to achieve fusion energy production through relatively small and compact devices compared to tokamaks decreases the costs and building time of the reactors and this has allowed some private companies to enter the field, like EMC2, General Fusion, Helion Energy, Lawrenceville Plasma Physics and Lockheed Martin. Some of these companies are trying to demonstrate net energy production within the next few years. If they are successful their next step is to attempt to commercialize their technology. In this presentation an overview of compact fusion reactor concepts is given.

  20. Compact nuclear fuel storage

    International Nuclear Information System (INIS)

    Kiselev, V.V.; Churakov, Yu.A.; Danchenko, Yu.V.; Bylkin, B.K.; Tsvetkov, S.V.

    1983-01-01

    Different constructions of racks for compact storage of spent fuel assemblies (FA) in ''coolin''g pools (CP) of NPPs with the BWR and PWR type reactors are described. Problems concerning nuclear and radiation safety and provision of necessary thermal conditions arising in such rack design are discussed. It is concluded that the problem of prolonged fuel storage at NPPs became Very actual for many countries because of retapdation of the rates of fuel reprocessing centers building. Application of compact storage racks is a promising solution of the problem of intermediate FA storage at NPPs. Such racks of stainless boron steel and with neutron absorbers in the from of boron carbide panels enable to increase the capacity of the present CP 2-2.6 times, and the period of FA storage in them up to 5-10 years

  1. Analysis of laboratory compaction methods of roller compacted concrete

    Science.gov (United States)

    Trtík, Tomáš; Chylík, Roman; Bílý, Petr; Fládr, Josef

    2017-09-01

    Roller-Compacted Concrete (RCC) is an ordinary concrete poured and compacted with machines typically used for laying of asphalt road layers. One of the problems connected with this technology is preparation of representative samples in the laboratory. The aim of this work was to analyse two methods of preparation of RCC laboratory samples with bulk density as the comparative parameter. The first method used dynamic compaction by pneumatic hammer. The second method of compaction had a static character. The specimens were loaded by precisely defined force in laboratory loading machine to create the same conditions as during static rolling (in the Czech Republic, only static rolling is commonly used). Bulk densities obtained by the two compaction methods were compared with core drills extracted from real RCC structure. The results have shown that the samples produced by pneumatic hammer tend to overestimate the bulk density of the material. For both compaction methods, immediate bearing index test was performed to verify the quality of compaction. A fundamental difference between static and dynamic compaction was identified. In static compaction, initial resistance to penetration of the mandrel was higher, after exceeding certain limit the resistance was constant. This means that the samples were well compacted just on the surface. Specimens made by pneumatic hammer actively resisted throughout the test, the whole volume was uniformly compacted.

  2. Compaction of cereal grain

    OpenAIRE

    Wychowaniec, J.; Griffiths, I.; Gay, A.; Mughal, A.

    2013-01-01

    We report on simple shaking experiments to measure the compaction of a column of Firth oat grain. Such grains are elongated anisotropic particles with a bimodal polydispersity. In these experiments, the particle configurations start from an initially disordered, low-packing-fraction state and under vertical shaking evolve to a dense state with evidence of nematic-like structure at the surface of the confining tube. This is accompanied by an increase in the packing fraction of the grain.

  3. Compact nuclear reactor

    International Nuclear Information System (INIS)

    Juric, S.I.

    1975-01-01

    A compact nuclear reactor of the pressurized-water variety is described which has two separate parts separably engageable for ease of inspection, maintenance and repair. One of the parts is a pressure vessel having an active core and the other of the parts is a closure adapted on its lower surface with an integral steam generator. An integral pump, external pressurizer and control rods are provided which communicate with the active core when engaged to form a total unit. (U.S.)

  4. Compact power reactor

    International Nuclear Information System (INIS)

    Wetch, J.R.; Dieckamp, H.M.; Wilson, L.A.

    1978-01-01

    There is disclosed a small compact nuclear reactor operating in the epithermal neutron energy range for supplying power at remote locations, as for a satellite. The core contains fuel moderator elements of Zr hydride with 7 w/o of 93% enriched uranium alloy. The core has a radial beryllium reflector and is cooled by liquid metal coolant such as NaK. The reactor is controlled and shut down by moving portions of the reflector

  5. CMS (Compact Muon Solenoid)

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    The milestone workshops on LHC experiments in Aachen in 1990 and at Evian in 1992 provided the first sketches of how LHC detectors might look. The concept of a compact general-purpose LHC experiment based on a solenoid to provide the magnetic field was first discussed at Aachen, and the formal Expression of Interest was aired at Evian. It was here that the Compact Muon Solenoid (CMS) name first became public. Optimizing first the muon detection system is a natural starting point for a high luminosity (interaction rate) proton-proton collider experiment. The compact CMS design called for a strong magnetic field, of some 4 Tesla, using a superconducting solenoid, originally about 14 metres long and 6 metres bore. (By LHC standards, this warrants the adjective 'compact'.) The main design goals of CMS are: 1 - a very good muon system providing many possibilities for momentum measurement (physicists call this a 'highly redundant' system); 2 - the best possible electromagnetic calorimeter consistent with the above; 3 - high quality central tracking to achieve both the above; and 4 - an affordable detector. Overall, CMS aims to detect cleanly the diverse signatures of new physics by identifying and precisely measuring muons, electrons and photons over a large energy range at very high collision rates, while also exploiting the lower luminosity initial running. As well as proton-proton collisions, CMS will also be able to look at the muons emerging from LHC heavy ion beam collisions. The Evian CMS conceptual design foresaw the full calorimetry inside the solenoid, with emphasis on precision electromagnetic calorimetry for picking up photons. (A light Higgs particle will probably be seen via its decay into photon pairs.) The muon system now foresaw four stations. Inner tracking would use silicon microstrips and microstrip gas chambers, with over 10 7 channels offering high track finding efficiency. In the central CMS barrel, the tracking elements are

  6. Compact Information Representations

    Science.gov (United States)

    2016-08-02

    Department of Defense, Executive Services, Directorate (0704-0188).   Respondents should be aware that notwithstanding any other provision of law, no person...which lies in the mission of AFOSR. 15.  SUBJECT TERMS sparse sampling , principal components analysis 16.  SECURITY CLASSIFICATION OF: 17...approved for public release Contents 1 Training for Ph.D. Students and Postdoc Researchers 2 2 Papers 2 3 Summary of Proposed Research: Compact

  7. Automated mini-column solid-phase extraction cleanup for high-throughput analysis of chemical contaminants in foods by low-pressure gas chromatography – tandem mass spectrometry

    Science.gov (United States)

    This study demonstrated the application of an automated high-throughput mini-cartridge solid-phase extraction (mini-SPE) cleanup for the rapid low-pressure gas chromatography – tandem mass spectrometry (LPGC-MS/MS) analysis of pesticides and environmental contaminants in QuEChERS extracts of foods. ...

  8. Crossover from Nonequilibrium Fractal Growth to Equilibrium Compact Growth

    DEFF Research Database (Denmark)

    Sørensen, Erik Schwartz; Fogedby, Hans C.; Mouritsen, Ole G.

    1988-01-01

    Solidification controlled by vacancy diffusion is studied by Monte Carlo simulations of a two-dimensional Ising model defined by a Hamiltonian which models a thermally driven fluid-solid phase transition. The nonequilibrium morphology of the growing solid is studied as a function of time as the s...... as the system relaxes into equilibrium described by a temperature. At low temperatures the model exhibits fractal growth at early times and crossover to compact solidification as equilibrium is approached....

  9. Rapid measurement of 13C-enrichment of acetic, propionic and butyric acids in plasma with solid phase microextraction coupled to gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    Moreau, N.M.; Delepee, R.; Maume, D.; Le Bizec, B.; Nguyen, P.G.; Champ, M.M.; Martin, L.J.; Dumon, H.J.

    2004-01-01

    An analytical procedure based on solid phase microextraction (SPME) has been developed to quantify [1- 13 C]-labelled short-chain fatty acids (SCFAs)--mainly acetic, propionic and butyric acids--in a small volume (120 μl) of deproteinised plasma (corresponding to 200 μl of raw plasma) by gas chromatography-mass spectrometry (GC-MS) analysis. Simultaneous SCFA extraction was optimal after 5 min using a 75 μm Carboxen/polydimethylsiloxane-coated fiber. The base peak of the three analytes has been characterised by middle-resolution mass spectrometry (R>6000). All these data allowed the specificity reinforcement of the measure. The validation of the method also considered the linearity and the repeatability of the [ 13 C]SCFA measurements by SPME-GC-MS. Results were linear in a range from 5 to 100 mol% of [ 13 C]SCFA enrichment and the method provided a good intra-day (R.S.D. 13 C]butyric acid) by cecal infusion before blood sampling in portal vein. Results of [1- 13 C]butyric acid enrichment showed an excellent correlation (r 2 =0.9832; n=30) with data obtained on the same samples using a previously published procedure based on diethyl extraction and derivatisation before GC-MS analyses. SPME coupled to GC-MS appears to be a powerful analytical tool for the direct isotopic measurements of low deproteinised plasma volume avoiding consequently preliminary treatment such as extraction or derivatisation. The presented method could be of great interest for real time [ 13 C]SCFA plasma determination of in metabolic in vivo studies in small animal models

  10. A Dual Source Ion Trap Mass Spectrometer for the Mars Organic Molecule Analyzer of ExoMars 2018

    Science.gov (United States)

    Brickerhoff, William B.; vanAmerom, F. H. W.; Danell, R. M.; Arevalo, R.; Atanassova, M.; Hovmand, L.; Mahaffy, P. R.; Cotter, R. J.

    2011-01-01

    We present details on the objectives, requirements, design and operational approach of the core mass spectrometer of the Mars Organic Molecule Analyzer (MOMA) investigation on the 2018 ExoMars mission. The MOMA mass spectrometer enables the investigation to fulfill its objective of analyzing the chemical composition of organic compounds in solid samples obtained from the near surface of Mars. Two methods of ionization are realized, associated with different modes of MOMA operation, in a single compact ion trap mass spectrometer. The stringent mass and power constraints of the mission have led to features such as low voltage and low frequency RF operation [1] and pulse counting detection.

  11. Facility for low-level solid waste treatment

    International Nuclear Information System (INIS)

    Vicente, R.; Miyamoto, H.

    1987-01-01

    A facility for low-level solid waste compaction, encapsulation and storage is described. Solid wastes are compacted in 200 l drums and stored over concrete platforms covered with canvas, for decay or for interim storage before transport to the final disposal site. (Author) [pt

  12. Diffusion through statically compacted clay

    International Nuclear Information System (INIS)

    Ho, C.L.; Shebl, M.A.A.

    1994-01-01

    This paper presents experimental work on the effect of compaction on contaminant flow through clay liners. The experimental program included evaluation of soil properties, compaction, permeability and solute diffusion. A permeameter was built of non reactive materials to test samples compacted at different water contents and compactive efforts. The flow of a permeating solute, LiCl, was monitored. Effluent samples were collected for solute concentration measurements. The concentrations were measured by performing atomic adsorption tests. The analyzed results showed different diffusion characteristics when compaction conditions changed. At each compactive effort, permeability decreased as molding water content increased. Consequently, transit time (measured at relative concentration 50%) increased and diffusivity decreased. As compactive effort increased for soils compacted dry of optimum, permeability and diffusion decreased. On the other hand, as compactive effort increased for soils compacted wet of optimum, permeability and diffusivity increased. Tortuosity factor was indirectly measured from the diffusion and retardation rate. Tortuosity factor also decreased as placement water content was increased from dry of optimum to wet of optimum. Then decreases were more pronounced for low compactive effort tests. 27 refs., 7 figs., 5 tabs

  13. A Rapid Magnetic Solid Phase Extraction Method Followed by Liquid Chromatography-Tandem Mass Spectrometry Analysis for the Determination of Mycotoxins in Cereals.

    Science.gov (United States)

    Barbera, Giorgia La; Capriotti, Anna Laura; Cavaliere, Chiara; Foglia, Patrizia; Montone, Carmela Maria; Chiozzi, Riccardo Zenezini; Laganà, Aldo

    2017-04-21

    Mycotoxins can contaminate various food commodities, including cereals. Moreover, mycotoxins of different classes can co-contaminate food, increasing human health risk. Several analytical methods have been published in the literature dealing with mycotoxins determination in cereals. Nevertheless, in the present work, the aim was to propose an easy and effective system for the extraction of six of the main mycotoxins from corn meal and durum wheat flour, i.e., the main four aflatoxins, ochratoxin A, and the mycoestrogen zearalenone. The developed method exploited magnetic solid phase extraction (SPE), a technique that is attracting an increasing interest as an alternative to classical SPE. Therefore, the use of magnetic graphitized carbon black as a suitable extracting material was tested. The same magnetic material proved to be effective in the extraction of mycoestrogens from milk, but has never been applied to complex matrices as cereals. Ultra high-performance liquid chromatography tandem mass spectrometry was used for detection. Recoveries were >60% in both cereals, even if the matrix effects were not negligible. The limits of quantification of the method results were comparable to those obtained by other two magnetic SPE-based methods applied to cereals, which were limited to one or two mycotoxins, whereas in this work the investigated mycotoxins belonged to three different chemical classes.

  14. Anaerobic digestion of solid slaughterhouse waste: study of biological stabilization by Fourier Transform infrared spectroscopy and thermogravimetry combined with mass spectrometry.

    Science.gov (United States)

    Cuetos, María José; Gómez, Xiomar; Otero, Marta; Morán, Antonio

    2010-07-01

    In this paper, Fourier Transform infrared spectroscopy (FTIR) along with thermogravimetric analysis together with mass spectrometry (TG-MS analysis) were employed to study the organic matter transformation attained under anaerobic digestion of slaughterhouse waste and to establish the stability of the digestates obtained when compared with fresh wastes. Digestate samples studied were obtained from successful digestion and failed systems treating slaughterhouse waste and the organic fraction of municipal solid wastes. The FTIR spectra and TG profiles from well stabilized products (from successful digestion systems) showed an increase in the aromaticity degree and the reduction of volatile content and aliphatic structures as stabilization proceeded. On the other hand, the FTIR spectra of non-stable reactors showed a high aliphaticity degree and fat content. When comparing differential thermogravimetry (DTG) profiles of the feed and digestate samples obtained from all successful anaerobic systems, a reduction in the intensity of the low-temperature range (approximately 300 degrees C) peak was observed, while the weight loss experienced at high-temperature (450-550 degrees C) was variable for the different systems. Compared to the original waste, the intensity of the weight loss peak in the high-temperature range decreased in the reactors with higher hydraulic retention time (HRT) whereas its intensity increased and the peak was displaced to higher temperatures for the digesters with lower HRT.

  15. Comparison of Histologic Core Portions Acquired from a Core Biopsy Needle and a Conventional Needle in Solid Mass Lesions: A Prospective Randomized Trial.

    Science.gov (United States)

    Lee, Ban Seok; Cho, Chang-Min; Jung, Min Kyu; Jang, Jung Sik; Bae, Han Ik

    2017-07-15

    The superiority of endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) over EUS-guided fine needle aspiration (EUS-FNA) remains controversial. Given the lack of studies analyzing histologic specimens acquired from EUS-FNB or EUS-FNA, we compared the proportion of the histologic core obtained from both techniques. A total of 58 consecutive patients with solid mass lesions were enrolled and randomly assigned to the EUS-FNA or EUS-FNB groups. The opposite needle was used after the failure of core tissue acquisition using the initial needle with up to three passes. Using computerized analyses of the scanned histologic slide, the overall area and the area of the histologic core portion in specimens obtained by the two techniques were compared. No significant differences were identified between the two groups with respect to demographic and clinical characteristics. Fewer needle passes were required to obtain core specimens in the FNB group (pcore (11.8%±19.5% vs 8.0%±11.1%, p=0.376) or in the diagnostic accuracy (80.6% vs 81.5%, p=0.935) between two groups. The proportion of histologic core and the diagnostic accuracy were comparable between the FNB and FNA groups. However, fewer needle passes were required to establish an accurate diagnosis in EUS-FNB.

  16. Cork as a new (green) coating for solid-phase microextraction: determination of polycyclic aromatic hydrocarbons in water samples by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Dias, Adriana Neves; Simão, Vanessa; Merib, Josias; Carasek, Eduardo

    2013-04-15

    A new fiber for solid-phase microextraction (SPME) was prepared employing cork as a coating. The morphology and composition of the cork fiber was evaluated by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), respectively. The proposed fiber was used for the determination of polycyclic aromatic hydrocarbons (PAHs) in river water samples by gas chromatography-selected ion monitoring-mass spectrometry (GC-SIM-MS). A central composite design was used for optimization of the variables involved in the extraction of PAHs from water samples. The optimal extraction conditions were extraction time and temperature of 60 min and 80°C, respectively. The detection and quantification limits were 0.03 and 0.1 μg L(-1), respectively. The recovery values were between 70.2 and 103.2% and the RSD was ≤15.7 (n=3). The linear range was 0.1-10 μg L(-1) with r≥0.96 and the fiber-to-fiber reproducibility showed RSD≤18.6% (n=5). The efficiency of the cork fiber was compared with commercially available fibers and good results were achieved, demonstrating the applicability and great potential of cork as a coating for SPME. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Speciation analysis of tellurium by solid-phase extraction in the presence of ammonium pyrrolidine dithiocarbamate and inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Chunhai; Cai, Qiantao; Guo, Zhong-Xian; Yang, Zhaoguang [Centre for Advanced Water Technology, Innovation Centre (NTU), Singapore (Singapore); Khoo, Soo Beng [Department of Chemistry, National University of Singapore (Singapore)

    2003-05-01

    Under acidic conditions tellurium(IV) formed a complex with ammonium pyrrolidine dithiocarbamate (APDC). The tellurium(IV) complex was completely retained on a non-polar Isolute silica-based octadecyl (C{sub 18}) sorbent-containing solid-phase extraction (SPE) cartridge, while the uncomplexed Te(VI) passed through the cartridge and remained as a free species in the solution. Only partial Te(IV) was retained on the SPE cartridge for samples without addition of APDC. On the basis of different retention behaviours of the complexed Te(IV) and uncomplexed Te(VI), a simple and highly sensitive method is proposed for the determination of total tellurium and Te(VI) by SPE separation and inductively coupled plasma mass spectrometry (ICP-MS) detection. The Te(IV) concentration was calculated as the difference between total tellurium and Te(VI) concentrations. The detection limit (3{sigma}) is 3 ng L{sup -1} tellurium. Factors affecting the separation and detection of tellurium species were investigated. Coexisting ions did not show significant interferences with the Te(IV)-APDC complex retention and the subsequent ICP-MS detection of Te. The method has been successfully applied to the tellurium speciation analysis in waters with spiked recoveries for Te(IV) and Te(VI) of 86.0-108% and 87.1-97.4%, respectively. (orig.)

  18. On-line solid-phase extraction coupled to hydrophilic interaction chromatography-mass spectrometry for the determination of polar drugs.

    Science.gov (United States)

    Fontanals, Núria; Marcé, Rosa M; Borrull, Francesc

    2011-09-02

    The present study describes the first fully automated method based on on-line solid-phase extraction (SPE) coupled to hydrophilic interaction chromatography-electrospray-mass spectrometry (HILIC-(ESI)MS) to determine a group of polar drugs that includes illicit drugs (such as cocaine, morphine, codeine and metabolites) and pharmaceuticals in environmental water samples. The SPE was performed using a highly retentive polymeric sorbent. The HILIC separation was optimised and the initial high organic content of the chromatographic mobile phase, was also suitable for the proper on-line elution of the analytes retained in the SPE column and for enhancing the ESI ionisation efficiency. This method allows the loading of samples of up to 250ml of ultrapure water or 10ml of environmental water samples spiked at low ngl(-1) levels of the analytes. The method yields near 100% recoveries for all the analytes. The method was also validated with environmental water samples with linear ranges from 5 to 1000ngl(-1) and limits of detection ≤2ngl(-1) for most of the compounds. Copyright © 2010 Elsevier B.V. All rights reserved.

  19. Determination of Triazine Herbicides in Drinking Water by Dispersive Micro Solid Phase Extraction with Ultrahigh-Performance Liquid Chromatography-High-Resolution Mass Spectrometric Detection.

    Science.gov (United States)

    Chen, Dawei; Zhang, Yiping; Miao, Hong; Zhao, Yunfeng; Wu, Yongning

    2015-11-11

    A novel dispersive micro solid phase extraction (DMSPE) method based on a polymer cation exchange material (PCX) was applied to the simultaneous determination of the 30 triazine herbicides in drinking water with ultrahigh-performance liquid chromatography-high-resolution mass spectrometric detection. Drinking water samples were acidified with formic acid, and then triazines were adsorbed by the PCX sorbent. Subsequently, the analytes were eluted with ammonium hydroxide/acetonitrile. The chromatographic separation was performed on an HSS T3 column using water (4 mM ammonium formate and 0.1% formic acid) and acetonitrile (0.1% formic acid) as the mobile phase. The method achieved LODs of 0.2-30.0 ng/L for the 30 triazines, with recoveries in the range of 70.5-112.1%, and the precision of the method was better than 12.7%. These results indicated that the proposed method had the advantages of convenience and high efficiency when applied to the analysis of the 30 triazines in drinking water.

  20. Liquid chromatography-mass spectrometry platform for both small neurotransmitters and neuropeptides in blood, with automatic and robust solid phase extraction

    Science.gov (United States)

    Johnsen, Elin; Leknes, Siri; Wilson, Steven Ray; Lundanes, Elsa

    2015-03-01

    Neurons communicate via chemical signals called neurotransmitters (NTs). The numerous identified NTs can have very different physiochemical properties (solubility, charge, size etc.), so quantification of the various NT classes traditionally requires several analytical platforms/methodologies. We here report that a diverse range of NTs, e.g. peptides oxytocin and vasopressin, monoamines adrenaline and serotonin, and amino acid GABA, can be simultaneously identified/measured in small samples, using an analytical platform based on liquid chromatography and high-resolution mass spectrometry (LC-MS). The automated platform is cost-efficient as manual sample preparation steps and one-time-use equipment are kept to a minimum. Zwitter-ionic HILIC stationary phases were used for both on-line solid phase extraction (SPE) and liquid chromatography (capillary format, cLC). This approach enabled compounds from all NT classes to elute in small volumes producing sharp and symmetric signals, and allowing precise quantifications of small samples, demonstrated with whole blood (100 microliters per sample). An additional robustness-enhancing feature is automatic filtration/filter back-flushing (AFFL), allowing hundreds of samples to be analyzed without any parts needing replacement. The platform can be installed by simple modification of a conventional LC-MS system.

  1. Identification and quantification of 56 targeted phenols in wines, spirits, and vinegars by online solid-phase extraction - ultrahigh-performance liquid chromatography - quadrupole-orbitrap mass spectrometry.

    Science.gov (United States)

    Barnaba, C; Dellacassa, E; Nicolini, G; Nardin, T; Malacarne, M; Larcher, R

    2015-12-04

    Phenolic compounds seriously affect the sensory and nutritional qualities of food products, both through the positive contribution of wood transfer in barrel-aged products and as off-flavours. A new targeted analytical approach combining on-line solid-phase extraction (SPE) clean-up to reduce matrix interference and rapid chromatographic detection performed with ultrahigh-performance liquid chromatography coupled with quadrupole/high-resolution mass spectrometry (Q-Orbitrap), was developed for the quantification of 56 simple phenols. Considering the advantages of using on-line SPE and a resolving power of 140,000, the proposed method was applied to define phenolic content in red (N=8) and white (8) wines, spirits (8), common (8) and balsamic (8) vinegars. The final method was linear from the limits of quantification (0.0001-0.001μgmL(-1)) up to 10μgmL(-1) with R(2) of at least 0.99. Recovery, used to define method accuracy, ranged from 80 to 120% for 89% of compounds. The method was suitable for analytical requirements in the tested matrices being able to analyse 46 phenols in red wines, 41 phenols in white wines and in spirits, 42 phenols in common vinegars and 44 phenols in balsamic vinegars. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Determination of different recreational drugs in sweat by headspace solid-phase microextraction gas chromatography mass spectrometry (HS-SPME GC/MS): Application to drugged drivers.

    Science.gov (United States)

    Gentili, Stefano; Mortali, Claudia; Mastrobattista, Luisa; Berretta, Paolo; Zaami, Simona

    2016-09-10

    A procedure based on headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography/mass spectrometry (GC/MS) has been developed for the determination of most commonly used drugs of abuse in sweat of drivers stopped during roadside controls. DrugWipe 5A sweat screening device was used to collect sweat by a specific pad rubbed gently over forehead skin surface. The procedure involved an acid hydrolysis, a HS-SPME extraction for drugs of abuse but Δ(9)-tetrahydrocannabinol, which was directly extracted in alkaline medium HS-SPME conditions, a GC separation of analytes by a capillary column and MS detection by electron impact ionisation. The method was linear from the limit of quantification (LOQ) to 50ng drug per pad (r(2)≥0.99), with an intra- and inter-assay precision and accuracy always less than 15% and an analytical recovery between 95.1% and 102.8%, depending on the considered analyte. Using the validated method, sweat from 60 apparently intoxicated drivers were found positive to one or more drugs of abuse, showing sweat patches testing as a viable economic and simple alternative to conventional (blood and/or urine) and non conventional (oral fluid) testing of drugs of abuse in drugged drivers. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Evaluation of volatile profiles obtained for minimally-processed pineapple fruit samples during storage by headspace-solid phase microextraction gas chromatography-mass spectrometry

    Directory of Open Access Journals (Sweden)

    Francielle Crocetta TURAZZI

    Full Text Available Abstract This paper describes the application of the solid-phase microextraction (SPME technique for the determination and monitoring of the volatile profile of minimally-processed pineapple fruit stored at various temperatures (-12 °C, 4 °C and 25 °C for different periods (1, 4 and 10 days. The SPME fiber coating composed of Car/PDMS presented the best performance. The optimal extraction conditions obtained through a Doehlert design were 60 min at 35 °C. The profiles for the volatile compounds content of the fruit at each stage of storage were determined by gas chromatography-mass spectrometry (GC-MS. The variation in the volatile profile over time was greater when the fruit samples were stored at 25 °C and at -12 °C compared to 4 °C. Thus, according to the volatile profiles associated with the storage conditions evaluated in this study, packaged pineapple retains best its fresh fruit aroma when stored at 4 °C.

  4. Analysis of the Volatile Profile of Core Chinese Mango Germplasm by Headspace Solid-Phase Microextraction Coupled with Gas Chromatography-Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Xiao-Wei Ma

    2018-06-01

    Full Text Available Despite abundant published research on the volatile characterization of mango germplasm, the aroma differentiation of Chinese cultivars remains unclear. Using headspace solid phase microextraction (HS-SPME coupled with gas chromatography–mass spectrometry (GC-MS, the composition and relative content of volatiles in 37 cultivars representing the diversity of Chinese mango germplasm were investigated. Results indicated that there are distinct differences in the components and content of volatile compounds among and within cultivars. In total, 114 volatile compounds, including 23 monoterpenes, 16 sesquiterpenes, 29 non-terpene hydrocarbons, 25 esters, 11 aldehydes, five alcohols and five ketones, were identified. The total volatile content among cultivars ranged from 211 to 26,022 μg/kg fresh weight (FW, with 123-fold variation. Terpene compounds were the basic background volatiles, and 34 cultivars exhibited abundant monoterpenes. On the basis of hierarchical cluster analysis (HCA and principal component analysis (PCA, terpinolene and α-pinene were important components constituting the aroma of Chinese mango cultivars. Most obviously, a number of mango cultivars with high content of various aroma components were observed, and they can serve as potential germplasms for both breeding and direct use.

  5. Trace-level determination of polar flavour compounds in butter by solid-phase extraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Adahchour, M; Vreuls, R J; van der Heijden, A; Brinkman, U A

    1999-06-04

    Volatile compounds are responsible for the aromas of butter. A simple technique for the determination of these components is described which is based on solid-phase extraction (SPE) after melting of the butter and separation of the aqueous phase from the fat. Volatile flavours present in the water fraction are collected by off-line SPE on cartidges packed with a copolymer sorbent. After desorption with 500 microliters of methyl acetate, 1-microliter aliquots are quantified and/or identified by gas chromatography-mass spectrometry. The procedure was tested with respect to recovery, linearity and limit of detection in real-life samples using five polar model analytes. It allows the characterisation of polar flavour compounds in butter prior to and after heat treatment at 170 degrees C. From the five model compounds, vanillin, traces of diacetyl and maltol were found to be present in the butter samples. After heat treatment 500-1000-fold increased concentration of maltol, and substantial amounts of furaneol were detected.

  6. Simultaneous determination of sulfonamides, tetracyclines and tiamulin in swine wastewater by solid-phase extraction and liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Ben, Weiwei; Qiang, Zhimin; Adams, Craig; Zhang, Heqing; Chen, Liping

    2008-08-22

    Little is known about the contamination level of antibiotics in swine wastewater in China. The highly complex matrix of swine wastewater, which generally has a chemical oxygen demand (COD) concentration as high as 15,000 mg/L, makes it difficult to detect antibiotics at trace levels. In this work, a highly selective and sensitive analytical method was developed for simultaneous determination of three classes of commonly used veterinary antibiotics including five sulfonamides, three tetracyclines and one macrolide in swine wastewater using solid-phase extraction (SPE) and liquid chromatography-mass spectrometry (LC-MS). The method detection limits (MDL) in the swine wastewater were determined to be between 5 and 91 ng/L, depending on specific antibiotics. Except sulfamethizole, all the other eight antibiotics were detected in the swine wastewaters collected from three concentrated swine feeding plants located in the Beijing (China) area, showing a concentration range of 0.62-32.67 microg/L. These results reveal the representative concentration levels of selected antibiotics in the swine wastewaters of Beijing area.

  7. A Method for Multiple Mycotoxin Analysis in Wines by Solid Phase Extraction and Multifunctional Cartridge Purification, and Ultra-High-Performance Liquid Chromatography Coupled to Tandem Mass Spectrometry

    Science.gov (United States)

    Tamura, Masayoshi; Takahashi, Ayumi; Uyama, Atsuo; Mochizuki, Naoki

    2012-01-01

    An analytical method using two solid phase extractions and ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) was developed for the identification and quantification of 14 mycotoxins (patulin, deoxynivalenol, aflatoxins B1, B2, G1, G2, M1, T-2 toxin, HT-2 toxin, zearalenone, fumonisins B1, B2, B3, and ochratoxin A) in domestic and imported wines. Mycotoxins were purified with an Oasis HLB cartridge, followed by a MultiSepTM #229 Ochra. As a result, sufficient removal of the pigments and highly polar matrices from the red wines was achieved. UHPLC conditions were optimized, and 14 mycotoxins were separated in a total of 13 min. Determinations performed using this method produced high correlation coefficients for the 14 mycotoxins (R > 0.990) and recovery rates ranging from 76 to 105% with good repeatability (relative standard deviation RSD < 12%). Twenty-seven samples of domestic and imported wines were analyzed using this method. Although ochratoxin A (OTA) and fumonisins (FMs) were detected in several samples, the FM levels were less than limits of quantification (LOQs) (1 μg/L), and even the largest of the OTA levels was below the EU regulatory level (2 μg/L). These results suggest that the health risk posed to consumers from the wines available in Japan is relatively low. PMID:22822458

  8. Classification of bacteria by simultaneous methylation-solid phase microextraction and gas chromatography/mass spectrometry analysis of fatty acid methyl esters.

    Science.gov (United States)

    Lu, Yao; Harrington, Peter B

    2010-08-01

    Direct methylation and solid-phase microextraction (SPME) were used as a sample preparation technique for classification of bacteria based on fatty acid methyl ester (FAME) profiles. Methanolic tetramethylammonium hydroxide was applied as a dual-function reagent to saponify and derivatize whole-cell bacterial fatty acids into FAMEs in one step, and SPME was used to extract the bacterial FAMEs from the headspace. Compared with traditional alkaline saponification and sample preparation using liquid-liquid extraction, the method presented in this work avoids using comparatively large amounts of inorganic and organic solvents and greatly decreases the sample preparation time as well. Characteristic gas chromatography/mass spectrometry (GC/MS) of FAME profiles was achieved for six bacterial species. The difference between Gram-positive and Gram-negative bacteria was clearly visualized with the application of principal component analysis of the GC/MS data of bacterial FAMEs. A cross-validation study using ten bootstrap Latin partitions and the fuzzy rule building expert system demonstrated 87 +/- 3% correct classification efficiency.

  9. Quantification of 2-acetyl-1-pyrroline in rice by stable isotope dilution assay through headspace solid-phase microextraction coupled to gas chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Maraval, Isabelle [UMR Qualisud, CIRAD, 73 Rue J. F. Breton, 34398 Montpellier Cedex 5 (France); UMR Qualisud, Universite Montpellier 2, place E. Bataillon, 34095 Montpellier Cedex 5 (France); Sen, Kemal [Department of Food Engineering, Faculty of Agriculture, University of Cukurova, 01330 Adana (Turkey); Agrebi, Abdelhamid; Menut, Chantal; Morere, Alain [UMR 5247, Institut des Biomolecules Max Mousseron (IBMM), CNRS, Universites Montpellier 2 et 1, Ecole Nationale Superieure de Chimie de Montpellier, 8 Rue de l' Ecole Normale, 34296 Montpellier Cedex 5 (France); Boulanger, Renaud [UMR Qualisud, CIRAD, 73 Rue J. F. Breton, 34398 Montpellier Cedex 5 (France); Gay, Frederic [CIRAD, DORAS Centre, Research and Development Building, Kasetsart University, Bangkok 10900 (Thailand); Mestres, Christian [UMR Qualisud, CIRAD, 73 Rue J. F. Breton, 34398 Montpellier Cedex 5 (France); Gunata, Ziya, E-mail: zgunata@univ-montp2.fr [UMR Qualisud, Universite Montpellier 2, place E. Bataillon, 34095 Montpellier Cedex 5 (France)

    2010-08-24

    A new and convenient synthesis of 2-acetyl-1-pyrroline (2AP), a potent flavor compound in rice, and its ring-deuterated analog, 2-acetyl-1-d{sub 2}-pyrroline (2AP-d{sub 2}), was reported. A stable isotope dilution assay (SIDA), involving headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-positive chemical ionization-ion trap-tandem mass spectrometry (GC-PCI-IT-MS-MS), was developed for 2AP quantification. A divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber was used for HS-SPME procedure and parameters affecting analytes recovery, such as extraction time and temperature, pH and salt, were studied. The repeatability of the method (n = 10) expressed as relative standard deviation (RSD) was 11.6%. A good linearity was observed from 5.9 to 779 ng of 2AP (r{sup 2} = 0.9989). Limits of detection (LOD) and quantification (LOQ) for 2AP were 0.1 and 0.4 ng g{sup -1} of rice, respectively. The recovery of spiked 2AP from rice matrix was almost complete. The developed method was applied to the quantification of 2AP in aerial parts and grains of scented and non-scented rice cultivars.

  10. Quantification of 13 priority polycyclic aromatic hydrocarbons in human urine by headspace solid-phase microextraction gas chromatography-isotope dilution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Campo, Laura [Department of Occupational and Environmental Health, University of Milan and Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Milan (Italy)], E-mail: laura.campo@unimi.it; Mercadante, Rosa; Rossella, Federica; Fustinoni, Silvia [Department of Occupational and Environmental Health, University of Milan and Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Milan (Italy)

    2009-01-12

    Polycyclic aromatic hydrocarbons (PAHs) are common environmental pollutants in both living and working environments. The aim of this study was the development of a headspace solid-phase microextraction gas chromatography-isotope dilution mass spectrometry (HS-SPME/GC-IDMS) method for the simultaneous quantification of 13 PAHs in urine samples. Different parameters affecting PAHs extraction by HS-SPME were considered and optimized: type/thickness of fiber coatings, extraction temperature/time, desorption temperature/time, ionic strength and sample agitation. The stability of spiked PAHs solutions and of real urine samples stored up to 90 days in containers of different materials was evaluated. In the optimized method, analytes were absorbed for 60 min at 80 deg. C in the sample headspace with a 100 {mu}m polydimethylsiloxane fiber. The method is very specific, with linear range from the limit of quantification to 8.67 x 10{sup 3} ng L{sup -1}, a within-run precision of <20% and a between-run precision of <20% for 2-, 3- and 4-ring compounds and of <30% for 5-ring compounds, trueness within 20% of the spiked concentration, and limit of quantification in the 2.28-2.28 x 10{sup 1} ng L{sup -1} range. An application of the proposed method using 15 urine samples from subjects exposed to PAHs at different environmental levels is shown.

  11. Ultra-high performance liquid chromatography tandem mass spectrometry for the determination of five glycopeptide antibiotics in food and biological samples using solid-phase extraction.

    Science.gov (United States)

    Deng, Fenfang; Yu, Hong; Pan, Xinhong; Hu, Guoyuan; Wang, Qiqin; Peng, Rongfei; Tan, Lei; Yang, Zhicong

    2018-02-23

    This paper demonstrated the development and validation of an ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method for simultaneous determination of five glycopeptide antibiotics in food and biological samples. The target glycopeptide antibiotics were isolated from the samples by solvent extraction, and the extracts were cleaned with a tandem solid-phase extraction step using mixed strong cation exchange and hydrophilic/lipophilic balance cartridges. Subsequently, the analytes were eluted with different solvents, and then quantified by UHPLC-MS/MS in the positive ionization mode with multiple reaction monitoring. Under optimal conditions, good linear correlations were obtained for the five glycopeptide antibiotics in the concentration range of 1.0 μg/L to 20.0 μg/L, and with linear correlation coefficients >0.998. Employing this method, the target glycopeptide antibiotics in food and biological samples were identified with a recovery of 83.0-102%, and a low quantitation limit of 1.0 μg/kg in food and 2.0 μg/L in biological samples with low matrix effects. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Application of dispersive solid-phase extraction and ultra-fast liquid chromatography-tandem quadrupole mass spectrometry in food additive residue analysis of red wine.

    Science.gov (United States)

    Chen, Xiao-Hong; Zhao, Yong-Gang; Shen, Hao-Yu; Jin, Mi-Cong

    2012-11-09

    A novel and effective dispersive solid-phase extraction (dSPE) procedure with rapid magnetic separation using ethylenediamine-functionalized magnetic polymer as an adsorbent was developed. The new procedure had excellent clean-up ability for the selective removal of the matrix in red wine. An accurate, simple, and rapid analytical method using ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS) for the simultaneous determination of nine food additives (i.e., acesulfame, saccharin, sodium cyclamate, aspartame, benzoic acid, sorbic acid, stevioside, dehydroacetic acid, and neotame) in red wine was also used and validated. Recoveries ranging from 78.5% to 99.2% with relative standard deviations ranging from 0.46% to 6.3% were obtained using the new method. All target compounds showed good linearities in the tested range with correlation coefficients (r) higher than 0.9993. The limits of quantification for the nine food additives were between 0.10 μg/L and 50.0 μg/L. The proposed dSPE-UFLC-MS/MS method was successfully applied in the food-safety risk monitoring of real red wine in Zhejiang Province, China. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

  13. 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.

  14. Multivariate optimization of a headspace solid-phase microextraction method followed by gas chromatography with mass spectrometry for the determination of terpenes in Nicotiana langsdorffii.

    Science.gov (United States)

    Ardini, Francisco; Carro, Marina Di; Abelmoschi, Maria Luisa; Grotti, Marco; Magi, Emanuele

    2014-07-01

    A simple and sensitive procedure based on headspace solid-phase microextraction and gas chromatography with mass spectrometry was developed for the determination of five terpenes (α-pinene, limonene, linalool, α-terpineol, and geraniol) in the leaves of Nicotiana langsdorffii. The microextraction conditions (extraction temperature, equilibration time, and extraction time) were optimized by means of a Doehlert design. The experimental design showed that, for α-pinene and limonene, a low temperature and a long extraction time were needed for optimal extraction, while linalool, α-terpineol, and geraniol required a high temperature and a long extraction time. The chosen compromise conditions were temperature 60°C, equilibration time 15 min and extraction time 50 min. The main analytical figures of the optimized method were evaluated; LODs ranged from 0.07 ng/g (α-pinene) to 8.0 ng/g (geraniol), while intraday and interday repeatability were in the range 10-17% and 9-13%, respectively. Finally, the procedure was applied to in vitro wild-type and transgenic specimens of N. langsdorffii subjected to abiotic stresses (chemical and heat stress). With the exception of geraniol (75-374 ng/g), low concentration levels of terpenes were measured (ng/g level or lower); some interesting variations in terpene concentration induced by abiotic stress were observed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Determination of N,N-dimethyltryptamine in beverages consumed in religious practices by headspace solid-phase microextraction followed by gas chromatography ion trap mass spectrometry.

    Science.gov (United States)

    Gaujac, Alain; Dempster, Nicola; Navickiene, Sandro; Brandt, Simon D; de Andrade, Jailson Bittencourt

    2013-03-15

    A novel analytical approach combining solid-phase microextraction (SPME)/gas chromatography ion trap mass spectrometry (GC-IT-MS) was developed for the detection and quantification N,N-dimethyltryptamine (DMT), a powerful psychoactive indole alkaloid present in a variety of South American indigenous beverages, such as ayahuasca and vinho da jurema. These particular plant products, often used within a religious context, are increasingly consumed throughout the world following an expansion of religious groups and the availability of plant material over the Internet and high street shops. The method described in the present study included the use of SPME in headspace mode combined GC-IT-MS and included the optimization of the SPME procedure using multivariate techniques. The method was performed with a polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber in headspace mode (70 min at 60 °C) which resulted in good precision (RSDvinho da jurema samples, obtained from Brazilian religious groups, which revealed DMT concentration levels between 0.10 and 1.81 g L(-1). Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Comparison of several solid-phase extraction sorbents for continuous determination of amines in water by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Jurado-Sánchez, Beatriz; Ballesteros, Evaristo; Gallego, Mercedes

    2009-08-15

    A semiautomatic method has been proposed for the determination of different types of amines in water samples including anilines, chloroanilines, N-nitrosamines and aliphatic amines. The analytes were retained on a solid-phase extraction sorbent column and after elution, 1 microL of the extract was analysed by gas chromatography coupled with electron impact ionization mass spectrometry. A systematic overview is given of the advantages and disadvantages of several sorbents (LiChrolut EN, Oasis HLB, RP-C(18), graphitized carbon black, fullerenes and nanotubes) in the retention of amine compounds and based on sensitivity, selectivity and reliability. The retention efficiency for the studied amines was higher (ca. 100%) with LiChrolut EN and Oasis HLB than it was with RP-C(18) and fullerenes (53 and 62%, respectively, on average). Detection limits of 0.5-16 ng L(-1) for the 27 amines studied were obtained when using a sorbent column containing 75 mg of LiChrolut EN for 100mL of sample, the RSD being lower than 6.5%. The method was applied with good accuracy and precision in the determination of amines in various types of water including river, pond, tap, well, drinking, swimming pool and waste.

  17. Quantitative analysis of 2-furfural and 5-methylfurfural in different Italian vinegars by headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry using isotope dilution.

    Science.gov (United States)

    Giordano, Lucia; Calabrese, Roberto; Davoli, Enrico; Rotilio, Domenico

    2003-10-31

    A new method was developed for the determination of 2-furfural (2-F) and 5-methylfurfural (5-MF), two products of Maillard reaction in vinegar, with head-space solid-phase microextraction (HS-SPME) coupled to gas chromatography-mass spectrometry (GC-MS). A divinylbenzene (DVB)/carboxen (CAR)/polydimethylsiloxane (PDMS) fibre was used and SPME conditions were optimised, studying ionic strength effect, temperature effect and adsorption time. Both analytes were determined by calibration established on 2-furfural-d4 (2-F-d4). The method showed good linearity in the range studied (from 16 to 0.12 mg/l), with a regression coefficient r2 of 0.9999. Inter-batch precision and accuracy were found between 14.9 and 6.0% and between -11.7 and 0.2%, respectively. Detection limit was 15 microg/l. The method is simple and accurate and it has been applied to a series of balsamic and non-balsamic vinegars.

  18. Comparison of dialysis and solid-phase extraction for isolation and concentration of dissolved organic matter prior to Fourier transform ion cyclotron resonance mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tfaily, Malak M.; Cooper, William T. [Florida State University, Department of Chemistry and Biochemistry, Tallahassee, FL (United States); Hodgkins, Suzanne; Chanton, Jeffrey P. [Florida State University, Department of Earth, Ocean and Atmospheric Science, Tallahassee, FL (United States); Podgorski, David C. [Florida State University, Department of Chemistry and Biochemistry, Tallahassee, FL (United States); Florida State University, National High Magnetic Field Laboratory, Tallahassee, FL (United States)

    2012-08-15

    We compare two methods, solid-phase extraction (SPE) and dialysis, commonly used for extraction and concentration of dissolved organic matter (DOM) prior to molecular characterization by electrospray ionization (ESI) and ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry. Spectra of DOM samples from Minnesota and Sweden peatlands that were extracted with styrene divinyl benzene polymer SPE sorbents included ions with formulas that had higher oxygen to carbon (O/C) ratios than spectra of DOM from the same samples after de-salting by dialysis. The SPE method was not very effective in extracting several major classes of DOM compounds that had high ESI efficiencies, including carboxylic acids and organo-sulfur compounds, and that out-competed other less-functionalized compounds (e.g., carbohydrates) for charge in the ESI source. The large abundance of carboxylic acids in the dialysisextracted DOM, likely the result of in situ microbial production, makes it difficult to see other (mainly hydrophilic) compounds with high O/C ratios. Our results indicate that, while dialysis is generally preferable for the isolation of DOM, for samples with high microbial inputs, the use of both isolation methods is recommended for a more accurate molecular representation. (orig.)

  19. Simultaneous Determination of Perfluorinated Compounds in Edible Oil by Gel-Permeation Chromatography Combined with Dispersive Solid-Phase Extraction and Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Yang, Lili; Jin, Fen; Zhang, Peng; Zhang, Yanxin; Wang, Jian; Shao, Hua; Jin, Maojun; Wang, Shanshan; Zheng, Lufei; Wang, Jing

    2015-09-30

    A simple analytical method was developed for the simultaneous analysis of 18 perfluorinated compounds (PFCs) in edible oil. The target compounds were extracted by acetonitrile, purified by gel permeation chromatography (GPC) and dispersive solid-phase extraction (DSPE) using graphitized carbon black (GCB) and octadecyl (C18), and analyzed by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ES-MS/MS) in negative ion mode. Recovery studies were performed at three fortification levels. The average recoveries of all target PFCs ranged from 60 to 129%, with an acceptable relative standard deviation (RSD) (1-20%, n = 3). The method detection limits (MDLs) ranged from 0.004 to 0.4 μg/kg, which was significantly improved compared with the existing liquid-liquid extraction and cleanup method. The method was successfully applied for the analysis of all target PFCs in edible oil samples collected from markets in Beijing, China, and the results revealed that C6-C10 perfluorocarboxylic acid (PFCAs) and C7 perfluorosulfonic acid PFSAs were the major PFCs detected in oil samples.

  20. A simple and sensitive approach to quantify methyl farnesoate in whole arthropods by matrix-solid phase dispersion and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Montes, Rosa; Rodil, Rosario; Neuparth, Teresa; Santos, Miguel M; Cela, Rafael; Quintana, José Benito

    2017-07-28

    Methyl farnesoate (MF) is an arthropod hormone that plays a key role in the physiology of several arthropods' classes being implicated in biological processes such as molting and reproduction. The development of an analytical technique to quantify the levels of this compound in biological tissues can be of major importance for the field of aquaculture/apiculture conservation and in endocrine disruption studies. Therefore, the aim of this study was to develop a simple and sensitive method to measure native levels of MF in the tissue of three representative species from different arthropods classes with environmental and/or economic importance. Thus, a new approach using whole organisms and the combination of matrix solid-phase dispersion with gas chromatography coupled to mass spectrometry was developed. This method allows quantifying endogenous MF at low levels (LOQs in the 1.2-3.1ng/g range) in three arthropod species, and could be expanded to additional arthropod classes. The found levels ranged between 2 and 12ng/g depending on the studied species and gender. The overall recovery of the method was evaluated and ranged between 69 and 96%. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. [Determination of 3-monochloropropane-1,2-diol in grease food by solid phase extraction-derivatization-gas chromatography-mass spectrometry].

    Science.gov (United States)

    Xiang, Xiaoling; Wang, Liyuan; Shen, Xianghong; Li, Chunsong; Shen, Jianfu; Wu, Pinggu

    2017-09-01

    To establish the method of determination of 3-monochloropropane-1,2-diol( 3-MCPD) in grease food by gas chromatography-mass spectrometry( GC-MS). 3-MCPD in grease food represented by bean paste was extracted by ultrasound,purified by alkaline earth solid phase extraction column,derivatived using phenylboronic acid( PBA) and detected by GC-MS. The linearity of 3-MCPD ranged from 1-100 ng/mL,with correlation coefficient at 0. 9993.The limits of quantitation( LOQ) in soy sauce,bean paste,pepper oil were 0. 6,0. 5 and7. 0 μg/kg and limits of detection( LOD) were 1. 9,1. 6 and 18. 8 μg/kg,respectively.Average recovery rate and relative standard deviation was 78. 3%-106. 7% and 1. 9%-11. 6%( n = 6), when 3-MCPD was added in grease food at 2. 5-1000 μg/kg. The method has good purification effect and the detection sensitivity and accuracy,and can be used for the determination of 3-MCPD in grease food.

  2. Barley husk carbon as the fiber coating for the solid-phase microextraction of twelve pesticides in vegetables prior to gas chromatography-mass spectrometric detection.

    Science.gov (United States)

    Liang, Weiqian; Wang, Juntao; Zang, Xiaohuan; Dong, Wenhuan; Wang, Chun; Wang, Zhi

    2017-03-31

    In this work, a barley husk biomaterial was successfully carbonized by hydrothermal method. The carbon had a high specific surface area and good stability. It was coated onto a stainless steel wire through sol-gel technique to prepare a solid-phase microextraction fiber for the extraction of trace levels of twelve pesticides (tsumacide, fenobucarb, indoxacarb, diethofencarb, thimet, terbufos, malathion, thiamethoxam, imidacloprid, buprofezin, acetamiprid, thiamethoxam) from vegetable samples prior to gas chromatography-mass spectrometric (GC-MS) detection. The main experimental parameters that could influence the extraction efficiency such as extraction time, extraction temperature, sample pH, sample salinity, stirring rate, desorption temperature and desorption time, were investigated. Under the optimized conditions, the linearity was observed in the range of 0.2-75.0μgkg -1 for tomato samples, and 0.3-60.0μgkg -1 for cucumber samples, with the correlation coefficients (r) ranging from 0.9959 to 0.9983. The limits of detection of the method were 0.01-0.05μgkg -1 for tomato samples, and 0.03-0.10μgkg -1 for cucumber samples. The recoveries of the analytes for the method from spiked samples were in the range of 76%-104%, and the precision, expressed as the relative standard deviations, was less than 12%. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Analyses of Indole Compounds in Sugar Cane (Saccharum officinarum L. Juice by High Performance Liquid Chromatography and Liquid Chromatography-Mass Spectrometry after Solid-Phase Extraction

    Directory of Open Access Journals (Sweden)

    Jean Wan Hong Yong

    2017-03-01

    Full Text Available Simultaneous quantitative analysis of 10 indole compounds, including indole-3-acetic acid (IAA, one of the most important naturally occurring auxins and some of its metabolites, by high performance liquid chromatography (HPLC and liquid chromatography-mass spectrometry (LC-MS after solid-phase extraction (SPE was reported for the first time. The analysis was carried out using a reverse phase HPLC gradient elution, with an aqueous mobile phase (containing 0.1% formic acid modified by methanol. Furthermore, a novel SPE procedure was developed for the pre-concentration and purification of indole compounds using C18 SPE cartridges. The combination of SPE, HPLC, and LC-MS was applied to screen for the indole compounds present in sugar cane (Saccharum officinarum L. juice, a refreshing beverage with various health benefits. Finally, four indole compounds were successfully detected and quantified in sugar cane juice by HPLC, which were further unequivocally confirmed by LC-MS/MS experiments operating in the multiple reaction monitoring (MRM mode.

  4. A Rapid Magnetic Solid Phase Extraction Method Followed by Liquid Chromatography-Tandem Mass Spectrometry Analysis for the Determination of Mycotoxins in Cereals

    Directory of Open Access Journals (Sweden)

    Giorgia La Barbera

    2017-04-01

    Full Text Available Mycotoxins can contaminate various food commodities, including cereals. Moreover, mycotoxins of different classes can co-contaminate food, increasing human health risk. Several analytical methods have been published in the literature dealing with mycotoxins determination in cereals. Nevertheless, in the present work, the aim was to propose an easy and effective system for the extraction of six of the main mycotoxins from corn meal and durum wheat flour, i.e., the main four aflatoxins, ochratoxin A, and the mycoestrogen zearalenone. The developed method exploited magnetic solid phase extraction (SPE, a technique that is attracting an increasing interest as an alternative to classical SPE. Therefore, the use of magnetic graphitized carbon black as a suitable extracting material was tested. The same magnetic material proved to be effective in the extraction of mycoestrogens from milk, but has never been applied to complex matrices as cereals. Ultra high–performance liquid chromatography tandem mass spectrometry was used for detection. Recoveries were >60% in both cereals, even if the matrix effects were not negligible. The limits of quantification of the method results were comparable to those obtained by other two magnetic SPE-based methods applied to cereals, which were limited to one or two mycotoxins, whereas in this work the investigated mycotoxins belonged to three different chemical classes.

  5. Fast analysis of glycosides based on HKUST-1-coated monolith solid-phase microextraction and direct analysis in real-time mass spectrometry.

    Science.gov (United States)

    Li, Xianjiang; Wang, Xin; Ma, Wen; Ai, Wanpeng; Bai, Yu; Ding, Li; Liu, Huwei

    2017-04-01

    Glycosides are a kind of highly important natural aromatic precursors in tobacco leaves. In this study, a novel HKUST-1-coated monolith dip-it sampler was designed for the fast and sensitive analysis of trace glycosides using direct analysis in real-time mass spectrometry. This device was prepared in two steps: in situ polymerization of monolith in a glass capillary of dip-it and layer-by-layer growth of HKUST-1 on the surface of monolith. Sufficient extraction was realized by immersing the tip to solution and in situ desorption was carried out by plasma direct analysis in real time. Compared with traditional solid-phase microextraction protocols, sample desorption was not needed anymore, and only extraction conditions were needed to be optimized in this method, including the gas temperature of direct analysis in real time, extraction time, and CH 3 COONH 4 additive concentration. This method enabled the simultaneous detection of six kinds of glycosides with the limits of detection of 0.02-0.05 μg/mL and the linear ranges covering two orders of magnitude with the limits of quantitation of 0.05-0.1 μg/mL. Moreover, the developed method was applied for the glycosides analysis of three tobacco samples, which only took about 2 s for every sample. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Determination of biocides and pesticides by on-line solid phase extraction coupled with mass spectrometry and their behaviour in wastewater and surface water

    International Nuclear Information System (INIS)

    Singer, Heinz; Jaus, Sylvia; Hanke, Irene; Lueck, Alfred; Hollender, Juliane; Alder, Alfredo C.

    2010-01-01

    This study focused on the input of hydrophilic biocides into the aquatic environment and on the efficiency of their removal in conventional wastewater treatment by a mass flux analysis. A fully automated method consisting of on-line solid phase extraction coupled to LC-ESI-MS/MS was developed and validated for the simultaneous trace determination of different biocidal compounds (1,2-benzisothiazoline-3-one (BIT), 3-Iodo-2-propynylbutyl-carbamate (IPBC), irgarol 1051 and 2-N-octyl-4-isothiazolinone (octhilinone, OIT), carbendazim, diazinon, diuron, isoproturon, mecoprop, terbutryn and terbutylazine) and pharmaceuticals (diclofenac and sulfamethoxazole) in wastewater and surface water. In the tertiary effluent, the highest average concentrations were determined for mecoprop (1010 ng/L) which was at comparable levels as the pharmaceuticals diclofenac (690 ng/L) and sulfamethoxazole (140 ng/L) but 1-2 orders of magnitude higher than the other biocidal compounds. Average eliminations for all compounds were usually below 50%. During rain events, increased residual amounts of biocidal contaminants are discharged to receiving surface waters. - Incomplete removal of biocides and pesticides during wastewater treatment.

  7. Determination of biocides and pesticides by on-line solid phase extraction coupled with mass spectrometry and their behaviour in wastewater and surface water

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Heinz; Jaus, Sylvia; Hanke, Irene; Lueck, Alfred; Hollender, Juliane [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600 Duebendorf (Switzerland); Alder, Alfredo C., E-mail: alfredo.alder@eawag.c [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600 Duebendorf (Switzerland)

    2010-10-15

    This study focused on the input of hydrophilic biocides into the aquatic environment and on the efficiency of their removal in conventional wastewater treatment by a mass flux analysis. A fully automated method consisting of on-line solid phase extraction coupled to LC-ESI-MS/MS was developed and validated for the simultaneous trace determination of different biocidal compounds (1,2-benzisothiazoline-3-one (BIT), 3-Iodo-2-propynylbutyl-carbamate (IPBC), irgarol 1051 and 2-N-octyl-4-isothiazolinone (octhilinone, OIT), carbendazim, diazinon, diuron, isoproturon, mecoprop, terbutryn and terbutylazine) and pharmaceuticals (diclofenac and sulfamethoxazole) in wastewater and surface water. In the tertiary effluent, the highest average concentrations were determined for mecoprop (1010 ng/L) which was at comparable levels as the pharmaceuticals diclofenac (690 ng/L) and sulfamethoxazole (140 ng/L) but 1-2 orders of magnitude higher than the other biocidal compounds. Average eliminations for all compounds were usually below 50%. During rain events, increased residual amounts of biocidal contaminants are discharged to receiving surface waters. - Incomplete removal of biocides and pesticides during wastewater treatment.

  8. A high-throughput solid-phase extraction microchip combined with inductively coupled plasma-mass spectrometry for rapid determination of trace heavy metals in natural water.

    Science.gov (United States)

    Shih, Tsung-Ting; Hsieh, Cheng-Chuan; Luo, Yu-Ting; Su, Yi-An; Chen, Ping-Hung; Chuang, Yu-Chen; Sun, Yuh-Chang

    2016-04-15

    Herein, a hyphenated system combining a high-throughput solid-phase extraction (htSPE) microchip with inductively coupled plasma-mass spectrometry (ICP-MS) for rapid determination of trace heavy metals was developed. Rather than performing multiple analyses in parallel for the enhancement of analytical throughput, we improved the processing speed for individual samples by increasing the operation flow rate during SPE procedures. To this end, an innovative device combining a micromixer and a multi-channeled extraction unit was designed. Furthermore, a programmable valve manifold was used to interface the developed microchip and ICP-MS instrumentation in order to fully automate the system, leading to a dramatic reduction in operation time and human error. Under the optimized operation conditions for the established system, detection limits of 1.64-42.54 ng L(-1) for the analyte ions were achieved. Validation procedures demonstrated that the developed method could be satisfactorily applied to the determination of trace heavy metals in natural water. Each analysis could be readily accomplished within just 186 s using the established system. This represents, to the best of our knowledge, an unprecedented speed for the analysis of trace heavy metal ions. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. A fast and simple solid phase microextraction coupled with gas chromatography-triple quadrupole mass spectrometry method for the assay of urinary markers of glutaric acidemias.

    Science.gov (United States)

    Naccarato, Attilio; Gionfriddo, Emanuela; Elliani, Rosangela; Sindona, Giovanni; Tagarelli, Antonio

    2014-10-30

    The analysis of characteristic urinary acidic markers such as glutaric, 3-hydroxyglutaric, 2-hydroxyglutaric, adipic, suberic, sebacic, ethylmalonic, 3-hydroxyisovaleric and isobutyric acid constitutes the recommended follow-up testing procedure for glutaric acidemia type 1 (GA-1) and type 2 (GA-2). The goal of the work herein presented is the development of a fast and simple method for the quantification of these biomarkers in human urine. The proposed analytical approach is based on the use of solid phase microextraction (SPME) combined with gas chromatography-triple quadrupole mass spectrometry (GC-QqQ-MS) afterward a rapid derivatization of acidic moieties by propyl chloroformate, propanol and pyridine. Trueness and precision of the proposed protocol, tested at 5, 30 and 80mgl -1 , provided satisfactory values: recoveries were in the range between 72% and 116% and the relative standard deviations (RSD%) were between 0.9% and 18% (except for isobutyric acid at 5mgl -1 ). The LOD values achieved by the proposed method ranged between 1.0 and 473μgl -1 . Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Determination of hydrazine in drinking water: Development and multivariate optimization of a rapid and simple solid phase microextraction-gas chromatography-triple quadrupole mass spectrometry protocol.

    Science.gov (United States)

    Gionfriddo, Emanuela; Naccarato, Attilio; Sindona, Giovanni; Tagarelli, Antonio

    2014-07-04

    In this work, the capabilities of solid phase microextraction were exploited in a fully optimized SPME-GC-QqQ-MS analytical approach for hydrazine assay. A rapid and easy method was obtained by a simple derivatization reaction with propyl chloroformate and pyridine carried out directly in water samples, followed by automated SPME analysis in the same vial without further sample handling. The affinity of the different derivatized compounds obtained towards five commercially available SPME coatings was evaluated, in order to achieve the best extraction efficiency. GC analyses were carried out using a GC-QqQ-MS instrument in selected reaction monitoring (SRM) acquisition mode which has allowed the achievement of high specificity by selecting appropriate precursor-product ion couples improving the capability in analyte identification. The multivariate approach of experimental design was crucial in order to optimize derivatization reaction, SPME process and tandem mass spectrometry parameters. Accuracy of the proposed protocol, tested at 60, 200 and 800 ng L(-1), provided satisfactory values (114.2%, 83.6% and 98.6%, respectively), whereas precision (RSD%) at the same concentration levels were of 10.9%, 7.9% and 7.7% respectively. Limit of detection and quantification of 4.4 and 8.3 ng L(-1) were obtained. The reliable application of the proposed protocol to real drinking water samples confirmed its capability to be used as analytical tool for routine analyses. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Differentiating benign from malignant solid breast masses: value of shear wave elastography according to lesion stiffness combined with greyscale ultrasound according to BI-RADS classification.

    Science.gov (United States)

    Evans, A; Whelehan, P; Thomson, K; Brauer, K; Jordan, L; Purdie, C; McLean, D; Baker, L; Vinnicombe, S; Thompson, A

    2012-07-10

    The aim of this study was to assess the performance of shear wave elastography combined with BI-RADS classification of greyscale ultrasound images for benign/malignant differentiation in a large group of patients. One hundred and seventy-five consecutive patients with solid breast masses on routine ultrasonography undergoing percutaneous biopsy had the greyscale findings classified according to the American College of Radiology BI-RADS. The mean elasticity values from four shear wave images were obtained. For mean elasticity vs greyscale BI-RADS, the performance results against histology were sensitivity: 95% vs 95%, specificity: 77% vs 69%, Positive Predictive Value (PPV): 88% vs 84%, Negative Predictive Value (NPV): 90% vs 91%, and accuracy: 89% vs 86% (all P>0.05). The results for the combination (positive result from either modality counted as malignant) were sensitivity 100%, specificity 61%, PPV 82%, NPV 100%, and accuracy 86%. The combination of BI-RADS greyscale and shear wave elastography yielded superior sensitivity to BI-RADS alone (P=0.03) or shear wave alone (P=0.03). The NPV was superior in combination compared with either alone (BI-RADS P=0.01 and shear wave P=0.02). Together, BI-RADS assessment of greyscale ultrasound images and shear wave ultrasound elastography are extremely sensitive for detection of malignancy.

  12. Simple and sensitive analysis of nereistoxin and its metabolites in human serum using headspace solid-phase microextraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Namera, A; Watanabe, T; Yashiki, M; Kojima, T; Urabe, T

    1999-03-01

    A simple method for the analysis of nereistoxin and its metabolites in human serum using headspace solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) is developed. A vial containing a serum sample, 5M sodium hydroxide, and benzylacetone (internal standard) is heated to 70 degrees C, and an SPME fiber is exposed for 30 min in the headspace of the vial. The compounds extracted by the fiber are desorbed by exposing the fiber in the injection port of the GC-MS. The calibration curves show linearity in the range of 0.05-5.0 micrograms/mL for nereistoxin and N-methyl-N-(2-methylthio-1-methylthiomethyl)ethylamine, 0.01-5.0 micrograms/mL for S,S'-dimethyl dihydronereistoxin, and 0.5-10 micrograms/mL for 2-methylthio-1-methylthiomethylethylamine in serum. No interferences are found, and the analysis time is 50 min for one sample. In addition, this proposed method is applied to a patient who attempted suicide by ingesting Padan 4R, a herbicide. Padan 4R contains 4% cartap hydrochloride, which is an analogue of nereistoxin. Nereistoxin and its metabolites are detected in the serum samples collected from the patient during hospitalization. The concentration ranges of nereistoxin in the serum are 0.09-2.69 micrograms/mL.

  13. Automated Online Solid-Phase Derivatization for Sensitive Quantification of Endogenous S-Nitrosoglutathione and Rapid Capture of Other Low-Molecular-Mass S-Nitrosothiols.

    Science.gov (United States)

    Wang, Xin; Garcia, Carlos T; Gong, Guanyu; Wishnok, John S; Tannenbaum, Steven R

    2018-02-06

    S-Nitrosothiols (RSNOs) constitute a circulating endogenous reservoir of nitric oxide and have important biological activities. In this study, an online coupling of solid-phase derivatization (SPD) with liquid chromatography-mass spectrometry (LC-MS) was developed and applied in the analysis of low-molecular-mass RSNOs. A derivatizing-reagent-modified polymer monolithic column was prepared and adapted for online SPD-LC-MS. Analytes from the LC autosampler flowed through the monolithic column for derivatization and then directly into the LC-MS for analysis. This integration of the online derivatization, LC separation, and MS detection facilitated system automation, allowing rapid, laborsaving, and sensitive detection of RSNOs. S-Nitrosoglutathione (GSNO) was quantified using this automated online method with good linearity (R 2 = 0.9994); the limit of detection was 0.015 nM. The online SPD-LC-MS method has been used to determine GSNO levels in mouse samples, 138 ± 13.2 nM of endogenous GSNO was detected in mouse plasma. Besides, the GSNO concentrations in liver (64.8 ± 11.3 pmol/mg protein), kidney (47.2 ± 6.1 pmol/mg protein), heart (8.9 ± 1.8 pmol/mg protein), muscle (1.9 ± 0.3 pmol/mg protein), hippocampus (5.3 ± 0.9 pmol/mg protein), striatum (6.7 ± 0.6 pmol/mg protein), cerebellum (31.4 ± 6.5 pmol/mg protein), and cortex (47.9 ± 4.6 pmol/mg protein) were also successfully quantified. When the derivatization was performed within 8 min, followed by LC-MS detection, samples could be rapidly analyzed compared with the offline manual method. Other low-molecular-mass RSNOs, such as S-nitrosocysteine and S-nitrosocysteinylglycine, were captured by rapid precursor-ion scanning, showing that the proposed method is a potentially powerful tool for capture, identification, and quantification of RSNOs in biological samples.

  14. Headspace solid-phase microextraction-gas chromatographic-time-of-flight mass spectrometric methodology for geographical origin verification of coffee

    International Nuclear Information System (INIS)

    Risticevic, Sanja; Carasek, Eduardo; Pawliszyn, Janusz

    2008-01-01

    Increasing consumer awareness of food safety issues requires the development of highly sophisticated techniques for the authentication of food commodities. The food products targeted for falsification are either products of high commercial value or those produced in large quantities. For this reason, the present investigation is directed towards the characterization of coffee samples according to the geographical origin. The conducted research involves the development of a rapid headspace solid-phase microextraction (HS-SPME)-gas chromatography-time-of-flight mass spectrometry (GC-TOFMS) method that is utilized for the verification of geographical origin traceability of coffee samples. As opposed to the utilization of traditional univariate optimization methods, the current study employs the application of multivariate experimental designs to the optimization of extraction-influencing parameters. Hence, the two-level full factorial first-order design aided in the identification of two influential variables: extraction time and sample temperature. The optimum set of conditions for the two variables was 12 min and 55 deg. C, respectively, as directed by utilization of Doehlert matrix and response surface methodology. The high-throughput automated SPME procedure was completed by implementing a single divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) 50/30 μm metal fiber with excellent durability properties ensuring the completion of overall sequence of coffee samples. The utilization of high-speed TOFMS instrument ensured the completion of one GC-MS run of a complex coffee sample in 7.9 min and the complete list of benefits provided by ChromaTOF software including fully automated background subtraction, baseline correction, peak find and mass spectral deconvolution algorithms was exploited during the data evaluation procedure. The combination of the retention index (RI) system using C 8 -C 40 alkanes and the mass spectral library search was utilized for the

  15. Headspace solid-phase microextraction-gas chromatographic-time-of-flight mass spectrometric methodology for geographical origin verification of coffee

    Energy Technology Data Exchange (ETDEWEB)

    Risticevic, Sanja [Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1 (Canada); Carasek, Eduardo [Department of Chemistry, Federal University of Santa Catarina, Trindade, Florianopolis, 88040-900, Santa Catarina (Brazil); Pawliszyn, Janusz [Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1 (Canada)], E-mail: janusz@uwaterloo.ca

    2008-06-09

    Increasing consumer awareness of food safety issues requires the development of highly sophisticated techniques for the authentication of food commodities. The food products targeted for falsification are either products of high commercial value or those produced in large quantities. For this reason, the present investigation is directed towards the characterization of coffee samples according to the geographical origin. The conducted research involves the development of a rapid headspace solid-phase microextraction (HS-SPME)-gas chromatography-time-of-flight mass spectrometry (GC-TOFMS) method that is utilized for the verification of geographical origin traceability of coffee samples. As opposed to the utilization of traditional univariate optimization methods, the current study employs the application of multivariate experimental designs to the optimization of extraction-influencing parameters. Hence, the two-level full factorial first-order design aided in the identification of two influential variables: extraction time and sample temperature. The optimum set of conditions for the two variables was 12 min and 55 deg. C, respectively, as directed by utilization of Doehlert matrix and response surface methodology. The high-throughput automated SPME procedure was completed by implementing a single divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) 50/30 {mu}m metal fiber with excellent durability properties ensuring the completion of overall sequence of coffee samples. The utilization of high-speed TOFMS instrument ensured the completion of one GC-MS run of a complex coffee sample in 7.9 min and the complete list of benefits provided by ChromaTOF software including fully automated background subtraction, baseline correction, peak find and mass spectral deconvolution algorithms was exploited during the data evaluation procedure. The combination of the retention index (RI) system using C{sub 8}-C{sub 40} alkanes and the mass spectral library search was

  16. Study of potential applications of compact ECRIS to analytical system

    International Nuclear Information System (INIS)

    Kidera, M.; Takahashi, K.; Seto, Y.; Kishi, S.; Enomoto, S.; Nagamatsu, T.; Tanaka, T.

    2012-01-01

    The objective of this study is to develop a desktop-sized system of element mass analysis (element analysis system) with a compact electron cyclotron resonance (ECR) ion source in the ionization section. This system is different from other element analysis systems in terms of the effective use of ionization by ECR plasma. A compact ECR ion source is required to fit in the desktop-sized element analysis system. This paper reporting the development of the compact ECR ion source, is followed by the associated poster. (authors)

  17. An Active Black Hole in a Compact Dwarf

    Science.gov (United States)

    Kohler, Susanna

    2016-05-01

    a supermassive black hole of ~2 million solar masses, according to the authors estimates. Paudel and collaboratorsshow that this mass is consistent with the low-mass extension of the known scaling relation between central black-hole mass and brightness of the host galaxy.Central black hole mass vs. bulge K-band magnitude. SDSS J085431.18+173730.5 (red dot) falls right on the low-mass extension of the observed scaling relation. It has similar properties to M32, another compact elliptical galaxy. [Adapted from Paudel et al. 2016]To add to the mystery, SDSS J085431.18+173730.5 has no nearby neighbors: like the few other isolated compact ellipticals recently discovered, there are no massive galaxies in the immediate vicinity that could have led to its tidal stripping. So how was this puzzling ancient galaxy formed?The authors of this study support a previously proposed flyby scenario: isolated compact ellipticals may simply be tidally stripped systems that ran away from their hosts. Paudel and collaborators suggest that SDSS J085431.18+173730.5 might have long ago interacted with NGC 2672 a galaxy group located a whopping 6.5 million light-years away before being flung out to its current location.Further studies of this unique galaxys emission profile, as well as efforts to learn about its underlying stellar population and central kinematics, will hopefully help us to better understand not only the origins of this galaxy, but how all compact ellipticals form and evolve.CitationSanjaya Paudel et al 2016 ApJ 820 L19. doi:10.3847/2041-8205/820/1/L19

  18. Black holes, white dwarfs, and neutron stars the physics of compact objects

    CERN Document Server

    Shapiro, Stuart Louis

    1983-01-01

    This self-contained textbook brings together many different branches of physics--e.g. nuclear physics, solid state physics, particle physics, hydrodynamics, relativity--to analyze compact objects. The latest astronomical data is assessed

  19. MECHANICS OF DYNAMIC POWDER COMPACTION PROCESS

    OpenAIRE

    Nurettin YAVUZ

    1996-01-01

    In recent years, interest in dynamic compaction methods of metal powders has increased due to the need to improve compaction properties and to increase production rates of compacts. In this paper, review of dynamic and explosive compaction of metal powders are given. An attempt is made to get a better understanding of the compaction process with the mechanicis of powder compaction.

  20. Volumetric characteristics and compactability of asphalt rubber mixtures with organic warm mix asphalt additives

    Directory of Open Access Journals (Sweden)

    A. M. Rodríguez-Alloza

    2017-04-01

    Full Text Available Warm Mix Asphalt (WMA refers to technologies that reduce manufacturing and compaction temperatures of asphalt mixtures allowing lower energy consumption and reducing greenhouse gas emissions from asphalt plants. These benefits, combined with the effective reuse of a solid waste product, make asphalt rubber (AR mixtures with WMA additives an excellent environmentally-friendly material for road construction. The effect of WMA additives on rubberized mixtures has not yet been established in detail and the lower mixing/compaction temperatures of these mixtures may result in insufficient compaction. In this sense, the present study uses a series of laboratory tests to evaluate the volumetric characteristics and compactability of AR mixtures with organic additives when production/compaction temperatures are decreased. The results of this study indicate that the additives selected can decrease the mixing/compaction temperatures without compromising the volumetric characteristics and compactability.

  1. Volumetric characteristics and compactability of asphalt rubber mixtures with organic warm mix asphalt additives

    International Nuclear Information System (INIS)

    Rodríguez-Alloza, A.M.; Gallego, J.

    2017-01-01

    Warm Mix Asphalt (WMA) refers to technologies that reduce manufacturing and compaction temperatures of asphalt mixtures allowing lower energy consumption and reducing greenhouse gas emissions from asphalt plants. These benefits, combined with the effective reuse of a solid waste product, make asphalt rubber (AR) mixtures with WMA additives an excellent environmentally-friendly material for road construction. The effect of WMA additives on rubberized mixtures has not yet been established in detail and the lower mixing/compaction temperatures of these mixtures may result in insufficient compaction. In this sense, the present study uses a series of laboratory tests to evaluate the volumetric characteristics and compactability of AR mixtures with organic additives when production/compaction temperatures are decreased. The results of this study indicate that the additives selected can decrease the mixing/compaction temperatures without compromising the volumetric characteristics and compactability. [es

  2. Compact neutron flux monitor

    International Nuclear Information System (INIS)

    Madhavi, V.; Phatak, P.R.; Bahadur, C.; Bayala, A.K.; Jakati, R.K.; Sathian, V.

    2003-01-01

    Full text: A compact size neutron flux monitor has been developed incorporating standard boards developed for smart radiation monitors. The sensitivity of the monitors is 0.4cps/nV. It has been tested up to 2075 nV flux with standard neutron sources. It shows convincing results even in high flux areas like 6m away from the accelerator in RMC (Parel) for 106/107 nV. These monitors have a focal and remote display, alarm function with potential free contacts for centralized control and additional provision of connectivity via RS485/Ethernet. This paper describes the construction, working and results of the above flux monitor

  3. Compact ignition experiments

    International Nuclear Information System (INIS)

    Angelini, A.; Coppi, B.; Nassi, M.

    1992-01-01

    This paper reports on high magnetic field experiments which can be designed to investigate D-T ignition conditions based on present-day experimental results and theoretical understanding of plasma phenomena. The key machine elements are: large plasma currents, compact dimensions, tight aspect ratios, moderate elongations and significant triangularities of the plasma column. High plasma densities, strong ohmic heating, the needed degree of energy confinement, good plasma purity and robust stability against ideal and resistive instabilities can be achieved simultaneously. The Ignitor design incorporates all these characteristics and involves magnet technology developments, started with the Alcator experiment, that use cryogenically cooled normal conductors

  4. Compact LINAC for deuterons

    International Nuclear Information System (INIS)

    Kurennoy, S.S.; O'Hara, J.F.; Rybarcyk, L.J.

    2008-01-01

    We are developing a compact deuteron-beam accelerator up to the deuteron energy of a few MeV based on room-temperature inter-digital H-mode (IH) accelerating structures with the transverse beam focusing using permanent-magnet quadrupoles (PMQ). Combining electromagnetic 3-D modeling with beam dynamics simulations and thermal-stress analysis, we show that IHPMQ structures provide very efficient and practical accelerators for light-ion beams of considerable currents at the beam velocities around a few percent of the speed of light. IH-structures with PMQ focusing following a short RFQ can also be beneficial in the front end of ion linacs.

  5. Compact synchrotron radiation source

    International Nuclear Information System (INIS)

    Liu, N.; Wang, T.; Tian, J.; Lin, Y.; Chen, S.; He, W.; Hu, Y.; Li, Q.

    1985-01-01

    A compact 800 MeV synchrotron radiation source is discussed. The storage ring has a circumference of 30.3 m, two 90 degree and four 45 degree bending magnet sections, two long straight sections and four short straight sections. The radius of the bending magnet is 2.224m. The critical wave length is 24A. The injector is a 15 Mev Microtron Electrons are accelerated from 15 Mev to 800 Mev by ramping the field of the ring. The expected stored current will be around 100 ma

  6. LASL Compact Torus Program

    International Nuclear Information System (INIS)

    Linford, R.K.; Armstrong, W.T.; Bartsch, R.R.

    1981-01-01

    The Compact Torus (CT) concept includes any axisymmetric toroidal plasma configuration, which does not require the linking of any material through the hole in the torus. Thus, the magnet coils, vacuum vessel, etc., have a simple cylindrical or spherical geometry instead of the toroidal geometry required for Tokamaks and RFP's. This simplified geometry results in substantial engineering advantages in CT reactor embodiments while retaining the good confinement properties afforded by an axisymmetric toroidal plasma-field geometry. CT's can be classified into three major types by using the ion gyro radius rho/sub i/ and the magnitude of the maximum toroidal field B/sub tm/

  7. Compact Q-balls

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D., E-mail: bazeia@fisica.ufpb.br [Departamento de Física, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB (Brazil); Losano, L.; Marques, M.A. [Departamento de Física, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB (Brazil); Menezes, R. [Departamento de Ciências Exatas, Universidade Federal da Paraíba, 58297-000 Rio Tinto, PB (Brazil); Departamento de Física, Universidade Federal de Campina Grande, 58109-970 Campina Grande, PB (Brazil); Rocha, R. da [Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, 09210-580 Santo André (Brazil)

    2016-07-10

    In this work we deal with non-topological solutions of the Q-ball type in two space–time dimensions, in models described by a single complex scalar field that engenders global symmetry. The main novelty is the presence of stable Q-balls solutions that live in a compact interval of the real line and appear from a family of models controlled by two distinct parameters. We find analytical solutions and study their charge and energy, and show how to control the parameters to make the Q-balls classically and quantum mechanically stable.

  8. Conductors, semiconductors, superconductors. A compact introduction to history, development, and theory of solid-state physics. 2. ed.; Leiter, Halbleiter, Supraleiter. Eine kompakte Einfuehrung in Geschichte, Entwicklung und Theorie der Festkoerperphysik

    Energy Technology Data Exchange (ETDEWEB)

    Huebener, Rudolf [Tuebingen Univ. (Germany). Fakultaet fuer Mathematik und Physik

    2017-05-01

    The present book is a strongly revised and supplemented edition of the title: ''Kristalle: Spiefeld der Elektronen'', published scarcely ten years ago by the same author. Especially the physical contents are explained by the mathematically formulated foundations. The book appeals to students of natural sciences and especially of physics as well as to engineers as introduction to the wide field of solid-state physics, so to speak as motivating prestage to the established and very extensive textbooks. Beside the physical contents the book treats the important role of numerous important and often still very young scientists. By corresponding supplements in this book it is tried to present the fundamental developments in their wide environment.

  9. Determination of volatile organic compounds in water by headspace solid-phase microextraction gas chromatography coupled to tandem mass spectrometry with triple quadrupole analyzer

    International Nuclear Information System (INIS)

    Cervera, M.I.; Beltran, J.; Lopez, F.J.; Hernandez, F.

    2011-01-01

    Highlights: → Employing a statistical optimization improves results reducing experiments. → Use of MS (QqQ) allows high sensitivity determination and improves identification capabilities. → Using Q/q intensity ratios is a powerful tool to ensure compound identification. → HS SPME GC-MS/MS method allows determination of VOCs in complex matrix water samples. - Abstract: In the present work, a rapid method with little sample handling has been developed for determination of 23 selected volatile organic compounds in environmental and wastewater samples. The method is based on headspace solid-phase microextraction (SPME) followed by gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) determination using triple quadrupole analyzer (QqQ) in electron ionization mode. The best conditions for extraction were optimised with a factorial design taking into account the interaction between different parameters and not only individual effects of variables. In the optimized procedure, 4 mL of water sample were extracted using a 10 mL vial and adding 0.4 g NaCl (final NaCl content of 10%). An SPME extraction with carboxen/polydimethylsiloxane 75 μm fiber for 30 min at 50 deg. C (with 5 min of previous equilibration time) with magnetic stirring was applied. Chromatographic determination was carried out by GC-MS/MS working in Selected Reaction Monitoring (SRM) mode. For most analytes, two MS/MS transitions were acquired, although for a few compounds it was difficult to obtain characteristic abundant fragments. In those cases, a pseudo selected reaction monitoring (pseudo-SRM) with three ions was used instead. The intensity ratio between quantitation (Q) and confirmation (q) signals was used as a confirmatory parameter. The method was validated by means of recovery experiments (n = 6) spiking mineral water samples at three concentration levels (0.1, 5 and 50 μg L -1 ). Recoveries between 70% and 120% were generally obtained with relative standard deviations (RSDs

  10. Determination of volatile organic compounds in water by headspace solid-phase microextraction gas chromatography coupled to tandem mass spectrometry with triple quadrupole analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Cervera, M.I. [Research Institute for Pesticides and Water, University Jaume I, Avda. Sos Baynat, E-12071 Castellon (Spain); Beltran, J., E-mail: joaquim.beltran@uji.es [Research Institute for Pesticides and Water, University Jaume I, Avda. Sos Baynat, E-12071 Castellon (Spain); Lopez, F.J.; Hernandez, F. [Research Institute for Pesticides and Water, University Jaume I, Avda. Sos Baynat, E-12071 Castellon (Spain)

    2011-10-17

    Highlights: {yields} Employing a statistical optimization improves results reducing experiments. {yields} Use of MS (QqQ) allows high sensitivity determination and improves identification capabilities. {yields} Using Q/q intensity ratios is a powerful tool to ensure compound identification. {yields} HS SPME GC-MS/MS method allows determination of VOCs in complex matrix water samples. - Abstract: In the present work, a rapid method with little sample handling has been developed for determination of 23 selected volatile organic compounds in environmental and wastewater samples. The method is based on headspace solid-phase microextraction (SPME) followed by gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) determination using triple quadrupole analyzer (QqQ) in electron ionization mode. The best conditions for extraction were optimised with a factorial design taking into account the interaction between different parameters and not only individual effects of variables. In the optimized procedure, 4 mL of water sample were extracted using a 10 mL vial and adding 0.4 g NaCl (final NaCl content of 10%). An SPME extraction with carboxen/polydimethylsiloxane 75 {mu}m fiber for 30 min at 50 deg. C (with 5 min of previous equilibration time) with magnetic stirring was applied. Chromatographic determination was carried out by GC-MS/MS working in Selected Reaction Monitoring (SRM) mode. For most analytes, two MS/MS transitions were acquired, although for a few compounds it was difficult to obtain characteristic abundant fragments. In those cases, a pseudo selected reaction monitoring (pseudo-SRM) with three ions was used instead. The intensity ratio between quantitation (Q) and confirmation (q) signals was used as a confirmatory parameter. The method was validated by means of recovery experiments (n = 6) spiking mineral water samples at three concentration levels (0.1, 5 and 50 {mu}g L{sup -1}). Recoveries between 70% and 120% were generally obtained with

  11. Rapid identification of microorganisms from positive blood cultures by MALDI-TOF mass spectrometry subsequent to very short-term incubation on solid medium.

    Science.gov (United States)

    Idelevich, E A; Schüle, I; Grünastel, B; Wüllenweber, J; Peters, G; Becker, K

    2014-10-01

    Rapid identification of the causative microorganism is important for appropriate antimicrobial therapy of bloodstream infections. Bacteria from positive blood culture (BC) bottles are not readily available for identification by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Lysis and centrifugation procedures suggested for direct MALDI-TOF MS from positive BCs without previous culture are associated with additional hands-on processing time and costs. Here, we describe an alternative approach applying MALDI-TOF MS from bacterial cultures incubated very briefly on solid medium. After plating of positive BC broth on Columbia blood agar (n = 165), MALDI-TOF MS was performed after 1.5, 2, 3, 4, 5, 6, 7, 8, 12 and (for control) 24 h of incubation until reliable identification to the species level was achieved (score ≥2.0). Mean incubation time needed to achieve species-level identification was 5.9 and 2.0 h for Gram-positive aerobic cocci (GPC, n = 86) and Gram-negative aerobic rods (GNR, n = 42), respectively. Short agar cultures with incubation times ≤2, ≤4, ≤6, ≤8 and ≤12 h yielded species identification in 1.2%, 18.6%, 64.0%, 96.5%, 98.8% of GPC, and in 76.2%, 95.2%, 97.6%, 97.6%, 97.6% of GNR, respectively. Control species identification at 24 h was achieved in 100% of GPC and 97.6% of GNR. Ethanol/formic acid protein extraction performed for an additional 34 GPC isolates cultivated from positive BCs showed further reduction in time to species identification (3.1 h). MALDI-TOF MS using