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Sample records for nitrique concentre application

  1. Refractive Secondary Concentrators for Solar Thermal Applications

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.; Macosko, Robert P.

    1999-01-01

    The NASA Glenn Research Center is developing technologies that utilize solar energy for various space applications including electrical power conversion, thermal propulsion, and furnaces. Common to all of these applications is the need for highly efficient, solar concentration systems. An effort is underway to develop the innovative single crystal refractive secondary concentrator, which uses refraction and total internal reflection to efficiently concentrate and direct solar energy. The refractive secondary offers very high throughput efficiencies (greater than 90%), and when used in combination with advanced primary concentrators, enables very high concentration ratios (10,0(X) to 1) and very high temperatures (greater than 2000 K). Presented is an overview of the refractive secondary concentrator development effort at the NASA Glenn Research Center, including optical design and analysis techniques, thermal modeling capabilities, crystal materials characterization testing, optical coatings evaluation, and component testing. Also presented is a discussion of potential future activity and technical issues yet to be resolved. Much of the work performed to date has been in support of the NASA Marshall Space Flight Center's Solar Thermal Propulsion Program. The many benefits of a refractive secondary concentrator that enable efficient, high temperature thermal propulsion system designs, apply equally well to other solar applications including furnaces and power generation systems such as solar dynamics, concentrated thermal photovoltaics, and thermionics.

  2. Nanofluidic concentration devices for biomolecules utilizing ion concentration polarization: theory, fabrication, and applications

    PubMed Central

    Kim, Sung Jae; Song, Yong-Ak; Han, Jongyoon

    2010-01-01

    Recently, a new type of electrokinetic concentration devices has been developed in a microfluidic chip format, which allows efficient trapping and concentration of biomolecules by utilizing ion concentration polarization near nanofluidic structures. These devices have drawn much attention not only due to their potential application in biomolecule sensing, but also due to the rich scientific content related to ion concentration polarization, the underlying physical phenomenon for the operation of these electrokinetic concentration devices. This tutorial review provides an introduction to the scientific and engineering advances achieved, in-depth discussion about several interesting applications of these unique concentration devices, and their current limitations and challenges. PMID:20179814

  3. Horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications.

    PubMed

    Ma, Hongcai; Wu, Lin

    2015-07-10

    We present the design of a horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications. This solar concentrator consists of an array of telecentric primary concentrators, a horizontally staggered lightguide layer, and a vertically tapered lightguide layer. The primary concentrator is realized by two plano-aspheric lenses with lateral movement and maintains a high F-number over an angle range of ±23.5°. The results of the simulations show that the solar concentrator achieves a high concentration ratio of 500× with ±0.5° of acceptance angle by a single-axis tracker and dual lateral translation stages. PMID:26193396

  4. Concentrating Solar Power Commercial Application Study

    SciTech Connect

    none,

    2009-10-01

    This report has been prepared in response to section 603(b) of the Energy Independence and Security Act of 2007, (Pub. L. No. 110-140), which states that “…the Secretary of Energy shall transmit to Congress a report on the results of a study on methods to reduce the amount of water consumed by concentrating solar power systems.”

  5. Applications of nonimaging optics for very high solar concentrations

    SciTech Connect

    O`Gallagher, J.; Winston, R.

    1997-12-31

    Using the principles and techniques of nonimaging optics, solar concentrations that approach the theoretical maximum can be achieved. This has applications in solar energy collection wherever concentration is desired. In this paper, we survey recent progress in attaining and using high and ultrahigh solar fluxes. We review a number of potential applications for highly concentrated solar energy and the current status of the associated technology. By making possible new and unique applications for intense solar flux, these techniques have opened a whole new frontier for research and development of potentially economic uses of solar energy.

  6. Trends in Concentrator, Receiver, and Storage Development for Terrestrial Applications

    NASA Technical Reports Server (NTRS)

    Roschke, E. J.; Owen, W. A.; Menard, W. A.; Fujita, T.

    1984-01-01

    The experience gained and the technical trends of the DOE-sponsored terrestrial solar thermal power systems project are summarized with respect to concentrator and receiver/storage development. Relevance of this experience to space power applications, and the perceived critical barriers of this technology, are discussed. It is concluded that, despite different objectives, the terrestrial program provides a strong basis of expertise valuable to space power applications development.

  7. Development of an advanced photovoltaic concentrator system for space applications

    NASA Technical Reports Server (NTRS)

    Piszczor, Michael F., Jr.; Oneill, Mark J.

    1987-01-01

    Recent studies indicate that significant increases in system performance (increased efficiency and reduced system mass) are possible for high power space based systems by incorporating technological developments with photovoltaic power systems. The Advanced Photovoltaic Concentrator Program is an effort to take advantage of recent advancements in refractive optical elements. By using a domed Fresnel lens concentrator and a prismatic cell cover, to eliminate metallization losses, dramatic reductions in the required area and mass over current space photovoltaic systems are possible. The advanced concentrator concept also has significant advantages when compared to solar dynamic Organic Rankine Cycle power systems in Low Earth Orbit applications where energy storage is required. The program is currently involved in the selection of a material for the optical element that will survive the space environment and a demonstration of the system performance of the panel design.

  8. Characterization of POF for liquid level and concentration sensing applications

    NASA Astrophysics Data System (ADS)

    Lumanta, B. G.; Candidato, R. T., Jr.; Reserva, R. L.

    2015-06-01

    Measuring liquid level and solution concentration play an important role in commercial and technological applications. For years, polymer optical fibers (POFs) have been very attractive for industrial applications because of their unique characteristics. In this work, we created simple, low cost and efficient set-up for sensing liquid level and solution concentration using POFs. We have calculated the acceptance angle of the POF to be 30°from numerical aperture (NA) measurements (NA ≈ 0.500).Images of a single POF showed the presence of impurities within the fiber which can contribute to power loss of the transmitted light. Light leakage was also observed when the fiber was bent to a tight radius, i.e. beyond its minimum bend radius of 15 mm. The experimental results show that as liquid level increases, the output power decreases. Furthermore, when the liquid concentration was increased, its response showed a greater loss of optical power due to the light rays in the submerged region of the POF tend to be refracted out of the fiber instead of being totally internally reflected and transmitted when index of refraction of the surrounding liquid medium is increased.

  9. Development of a Fresnel lens concentrator for space application

    NASA Technical Reports Server (NTRS)

    Oneill, Mark J.; Piszczor, Michael F.

    1987-01-01

    The selected conceptual design of the dome lens photovoltaic concentrator for space applications uses a 3.7 cm square aperture dome lens to focus onto a 0.4 cm active diameter gallium arsenide cell. The selected configuration will provide 91.5 percent lens optical efficiency and 21.4 percent cell efficiency at 100 suns irradiance and 100 C cell temperature, for an overall cell efficiency of 19.6 percent. The selected configuration will tolerate 1 degree tracking errors with negligible loss of performance. The selected panel weight is 2.5 kg/sq.m.

  10. Application of Medical Magnetic Resonance Imaging for Particle Concentration Measurement

    NASA Astrophysics Data System (ADS)

    Borup, Daniel; Elkins, Christopher; Eaton, John

    2014-11-01

    Particle transport and deposition in internal flows is important in a range of applications such as dust aggregation in turbine engines and aerosolized medicine deposition in human airways. Unlike optical techniques, Magnetic Resonance Imaging (MRI) is well suited for complex applications in which optical access is not possible. Here we present efforts to measure 3D particle concentration distribution using MRI. Glass particles dispersed in water flow reduce MRI signal from a spin-echo or gradient-echo scanning sequence by decreasing spin density and dephasing the spins present in the fluid. A preliminary experiment was conducted with a particle streak injected at the centerline of a turbulent round pipe flow with a U bend. Measurements confirmed that signal strength was related to particle concentration and showed the effects of gravitational settling and turbulent dispersion. Next, measurements of samples in a mixing chamber were taken. Particle volume fraction was varied and sensitivity to particle/fluid velocity was investigated. These results give a relationship between MRI signal, particle volume fraction, MRI sequence echo time, and spin relaxation parameters that can be used to measure local particle volume fraction in other turbulent flows of interest.

  11. [Inhaled nitric monoxide. Application and continuous measurement of concentration].

    PubMed

    Benzing, A; Beyer, U; Kiefer, P; Geiger, K

    1993-03-01

    Inhaled nitric oxide (NO) is a selective pulmonary vasodilator that may be useful in the treatment of patients with severe pulmonary hypertension. We describe a delivery system of inhaled NO that allows safe application and continuous measurement of the inspired NO concentration during mechanical ventilation. From a gas cylinder containing NO in N2 (600 ppm NO), an adjustable amount of gas is introduced into the inspiratory side of the tubing system via a pressure reduction valve, a magnetic valve, and a special injection nozzle. The NO concentration is diluted to the desired value by the tidal volume. The magnetic valve is connected to the ventilator and opens at the beginning of each inspiration and closes after a predetermined time. The gas volume is proportional to the pressure at the magnetic valve and the opening time. To monitor the inspiratory NO concentration, a specimen of gas is taken from an angle-connector and passed over an electrochemical sensor. The second nozzle of the sensor is connected to a water seal, which is adjusted to the positive end-expiratory pressure level of the ventilator to insure that the gas flow over the sensor is limited to inspiration. PMID:8480905

  12. Solar concentrator technology development for space based applications, volume 1

    NASA Technical Reports Server (NTRS)

    Pintz, A.; Castle, C. H.; Reimer, R. R.

    1992-01-01

    Thermoelectric conversion using a radio-isotope heat source has been used where outer planetary space craft are too far away for absorbing significant solar energy. Solar dynamic power (SDP) conversion is one technology that offers advantages for applications within the inner planet region. Since SDP conversion efficiency can be 2 to 3 times higher than photovoltaic, the collecting surfaces are much reduced in area and therefore lighter. This becomes an advantage in allocating more weight to launched payloads. A second advantage results for low earth orbit applications. The reduced area results in lower drag forces on the spacecraft and requires less reboost propellant to maintain orbit. A third advantage occurs because of the sun-to-shade cycling while in earth orbit. Photovoltaic systems require batteries to store energy for use when in the shade, and battery life for periods of 10 to 15 years is not presently achievable. For these reasons the Solar Dynamics and Thermal Systems Branch at NASA LeRC has funded work in developing SDP systems. The generic SDP system uses a large parabolic solar concentrator to focus solar energy onto a power conversion device. The concentrators are large areas and must therefore be efficient and have low specific weights. Yet these surfaces must be precise and capable of being stowed in a launch vehicle and then deployed and sometimes unfurled in space. There are significant technical challenges in engineering such structures, and considerable investigation has been made to date. This is the first of two volumes reporting on the research done by the Advanced Manufacturing Center at Cleveland State University to assist NASA LeRC in evaluating this technology. The objective of the grant was to restore the solar concentrator development technology of the 1960s while improving it with advances that have occurred since then. This report summarizes the work done from January 1989 through December 1991.

  13. Solar concentrator technology development for space based applications, volume 2

    NASA Technical Reports Server (NTRS)

    Pintz, A.; Castle, C. H.; Reimer, R. R.

    1992-01-01

    Thermoelectric conversion using a radio-isotope heat source has been used where outer planetary space craft are too far away for absorbing significant solar energy. Solar dynamic power (SDP) conversion is one technology that offers advantages for applications within the inner planet region. Since SDP conversion efficiency can be 2 to 3 times higher than photovoltaic, the collecting surfaces are much reduced in area and therefore lighter. This becomes an advantage in allocating more weight to launched payloads. A second advantage results for low earth orbit applications. The reduced area results in lower drag forces on the spacecraft and requires less reboost propellant to maintain orbit. A third advantage occurs because of the sun-to-shade cycling while in earth orbit. Photovoltaic systems require batteries to store energy for use when in the shade, and battery life for periods of 10 to 15 years is not presently achievable. For these reasons the Solar Dynamics and Thermal Systems Branch at NASA LeRC has funded work in developing SDP systems. The generic SDP system uses a large parabolic solar concentrator to focus solar energy onto a power conversion device. The concentrators are large areas and must therefore be efficient and have low specific weights. Yet these surfaces must be precise and capable of being stowed in a launch vehicle and then deployed and sometimes unfurled in space. There are significant technical challenges in engineering such structures, and considerable investigation has been made to date. This is the second of two volumes reporting on the research done by the Advanced Manufacturing Center at Cleveland State University to assist NASA LeRC in evaluating this technology. This volume includes the appendices of selected data sets, drawings, and procedures. The objective of the grant was to restore the solar concentrator development technology of the 1960s while improving it with advances that have occurred since then. This report summarizes the

  14. Ultralight stretched Fresnel lens solar concentrator for space power applications

    NASA Astrophysics Data System (ADS)

    O'Neill, Mark J.; Piszczor, Michael F.; Eskenazi, Michael I.; McDanal, A. J.; George, Patrick J.; Botke, Matthew M.; Brandhorst, Henry W.; Edwards, David L.; Hoppe, David T.

    2003-12-01

    A unique ultra-light solar concentrator has recently been developed for space power applications. The concentrator comprises a flexible, 140-micron-thick, line-focus Fresnel lens, made in a continuous process from space-qualified transparent silicone rubber material. For deployment and support in space, end arches are used to tension the lens material in a lengthwise fashion, forming a cylindrical stressed membrane structure. The resultant lens provides high optical efficiency, outstanding tolerance for real-world errors and aberrations, and excellent focusing performance. The stretched lens is used to collect and focus sunlight at 8X concentration onto high-efficiency multi-junction photovoltaic cells, which directly convert the incident solar energy to electricity. The Stretched Lens Array (SLA) has been measured at over 27% net solar-to-electric conversion efficiency for space sunlight, and over 30% net solar-to-electric conversion efficiency for terrestrial sunlight. More importantly, the SLA provides over 180 W/kg specific power at a greatly reduced cost compared to conventional planar photovoltaic arrays in space. The cost savings are due to the use of 85% less of the expensive solar cell material per unit of power produced. SLA is a direct descendent of the award-winning SCARLET array which performed flawlessly on the NASA/JPL Deep Space 1 spacecraft from 1998-2001. The paper describes the new concentrator in more detail, including its materials and configuration, and shows the novel approach to deployment and support, which leads to unprecedented performance metrics for a space power system.

  15. Predicting indoor pollutant concentrations, and applications to air quality management

    SciTech Connect

    Lorenzetti, David M.

    2002-10-01

    Because most people spend more than 90% of their time indoors, predicting exposure to airborne pollutants requires models that incorporate the effect of buildings. Buildings affect the exposure of their occupants in a number of ways, both by design (for example, filters in ventilation systems remove particles) and incidentally (for example, sorption on walls can reduce peak concentrations, but prolong exposure to semivolatile organic compounds). Furthermore, building materials and occupant activities can generate pollutants. Indoor air quality depends not only on outdoor air quality, but also on the design, maintenance, and use of the building. For example, ''sick building'' symptoms such as respiratory problems and headaches have been related to the presence of air-conditioning systems, to carpeting, to low ventilation rates, and to high occupant density (1). The physical processes of interest apply even in simple structures such as homes. Indoor air quality models simulate the processes, such as ventilation and filtration, that control pollutant concentrations in a building. Section 2 describes the modeling approach, and the important transport processes in buildings. Because advection usually dominates among the transport processes, Sections 3 and 4 describe methods for predicting airflows. The concluding section summarizes the application of these models.

  16. Optical investigation of a sun simulator for concentrator PV applications.

    PubMed

    Rapp, Christoph; Straub, Volker; van Rooyen, De Wet; Thor, Wei Yi; Siefer, Gerald; Bett, Andreas W

    2015-09-21

    In photovoltaics (PV), sun simulators are used to reproduce outdoor conditions in a lab environment such as irradiance level, light uniformity and spectral distribution. Concentrator (C)PV applications additionally require the sun simulators to provide rays with an angular distribution similar to that of the sun rays. However, different factors in CPV sun simulator setups make it difficult to achieve the perfect sun like angular distribution. This is mainly caused by the unavailability of appropriate light sources. Therefore, we investigated in this work, to which deviations such a non-ideal light source can lead and which impact is expected at the measurement of a CPV module. For this, two ray tracing models are presented - one for the simulation of natural sunrays, another one for the simulation of sun simulator conditions. The models are validated based on measurements and subsequently used to simulate the impact on a typical CPV module with silicone-on-glass Fresnel lenses. Here, significant deviations to outdoor conditions are found. PMID:26406756

  17. Focusing particle concentrator with application to ultrafine particles

    DOEpatents

    Hering, Susanne; Lewis, Gregory; Spielman, Steven R.

    2013-06-11

    Technology is presented for the high efficiency concentration of fine and ultrafine airborne particles into a small fraction of the sampled airflow by condensational enlargement, aerodynamic focusing and flow separation. A nozzle concentrator structure including an acceleration nozzle with a flow extraction structure may be coupled to a containment vessel. The containment vessel may include a water condensation growth tube to facilitate the concentration of ultrafine particles. The containment vessel may further include a separate carrier flow introduced at the center of the sampled flow, upstream of the acceleration nozzle of the nozzle concentrator to facilitate the separation of particle and vapor constituents.

  18. Ultrasonic analyte concentration and application in flow cytometry

    DOEpatents

    Kaduchak, Gregory; Goddard, Greg; Salzman, Gary; Sinha, Dipen; Martin, John C.; Kwiatkowski, Christopher; Graves, Steven

    2008-03-11

    The present invention includes an apparatus and corresponding method for concentrating analytes within a fluid flowing through a tube using acoustic radiation pressure. The apparatus includes a function generator that outputs a radio frequency electrical signal to a transducer that transforms the radio frequency electric signal to an acoustic signal and couples the acoustic signal to the tube. The acoustic signal is converted within the tube to acoustic pressure that concentrates the analytes within the fluid.

  19. Ultrasonic analyte concentration and application in flow cytometry

    SciTech Connect

    Kaduchak, Gregory; Goddard, Greg; Salzman, Gary; Sinha, Dipen; Martin, John C.; Kwiatkowski, Christopher; Graves, Steven

    2014-07-22

    The present invention includes an apparatus and corresponding method for concentrating analytes within a fluid flowing through a tube using acoustic radiation pressure. The apparatus includes a function generator that outputs a radio frequency electrical signal to a transducer that transforms the radio frequency electric signal to an acoustic signal and couples the acoustic signal to the tube. The acoustic signal is converted within the tube to acoustic pressure that concentrates the analytes within the fluid.

  20. Ultrasonic analyte concentration and application in flow cytometry

    SciTech Connect

    Kaduchak, Gregory; Goddard, Greg; Salzman, Gary; Sinha, Dipen; Martin, John C.; Kwiatkowski, Christopher; Graves, Steven

    2015-07-07

    The present invention includes an apparatus and corresponding method for concentrating analytes within a fluid flowing through a tube using acoustic radiation pressure. The apparatus includes a function generator that outputs a radio frequency electrical signal to a transducer that transforms the radio frequency electric signal to an acoustic signal and couples the acoustic signal to the tube. The acoustic signal is converted within the tube to acoustic pressure that concentrates the analytes within the fluid.

  1. Winston Solar Concentrators and Evaluation Support. Phase 2: Non-imaging Concentrators for Space Applications

    NASA Technical Reports Server (NTRS)

    Winston, R.; Ogallagher, J.; Greenman, P.

    1978-01-01

    A 4.67X, plus or minus 5 deg. compound parabolic concentrator (CPC) for a large photovoltaic array in space was analyzed. The design was demonstrated to be effective in achieving a net power gain which can be varied from more than a factor of 3 down to approximately unity. A method for reducing nonuniformities in illumination to a given desired level was found. The effectiveness of this method, which involves the introduction of a degree of non-specularity in the reflector surface, was confirmed by direct measurements with prepared foil reflectors in a CPC in terrestrial sunshine as well as by computer ray tracing. Further ray tracing confirms that the CPC design is extremely tolerant to pointing and alignment errors, minor distortions, etc. A two stage non-imaging design was shown, by preliminary measurements and analysis, to provide both the desired angular tolerance and the required degree of intensity uniformity if higher concentrations (4X-10X) are necessary.

  2. InP concentrator solar cells for space applications

    NASA Technical Reports Server (NTRS)

    Ward, J. S.; Wanlass, M. W.; Coutts, T. J.; Emery, K. A.

    1991-01-01

    The design, fabrication, and characterization of high-performance, n(+)/p InP shallow-homojunction (SHJ) concentrator solar cells is described. The InP device structures were grown by atmospheric-pressure metalorganic vapor phase epitaxy (APMOVPE). A preliminary assessment of the effects of grid collection distance and emitter sheet resistance on cell performance is presented. At concentration ratios of over 100, cells with AM0 efficiencies in excess of 21 percent at 25 C and 19 percent at 80 C are reported. These results indicate that high-efficiency InP concentrator cells can be fabricated using existing technologies. The performance of these cells as a function of temperature is discussed, and areas for future improvement are outlined.

  3. Domed Fresnel lens concentrator technology for space application

    NASA Technical Reports Server (NTRS)

    Piszczor, Michael F., Jr.; Oneill, Mark J.

    1989-01-01

    Over the past three years, NASA Lewis and Entech, Inc. have been investigating the use of high efficiency refractive photovoltaic concentrators for use in space. The design currently under investigation uses a square domed Fresnel lens to focus light on a GaAs concentrator cell. A prismatic cell cover, which directs light away from the front contacts and thus eliminates metalization losses, is applied to the top of the GaAs cell to further enhance array efficiency. The latest experimental results based on testing the GaAs cell/prism cover assembly at standard and operating conditions are presented.

  4. Spacecraft Minimum Allowable Concentrations: Determination, Application, and Contingency Situations

    NASA Technical Reports Server (NTRS)

    Marshburn, Thomas H.; Dawson, David L. (Technical Monitor)

    1999-01-01

    This document is an outline of a presentation about the determination of minimum allowable concentrations in spacecraft. The presentation reviews the type of toxins and mechanisms to determine the acceptable concentrations of these toxic substances. The considerations for the unique situation that spaceflight entails including zero gravity, and the intense scrutiny are reviewed. The current measurement hardware is reviewed. The spacecraft atmospheres on the Shuttle, airflow, the Space Station and the EMU in respect to airflow, pressure, constituents are also summarized. Contingency situations and potential hazards are also discussed.

  5. Tracking-integrated optics: applications in solar concentration

    NASA Astrophysics Data System (ADS)

    Wheelwright, Brian M.; Angel, Roger; Coughenour, Blake

    2014-12-01

    Conventional concentrating photovoltaic (CPV) systems track the sun with high precision dual-axis trackers. The emergent field of tracking-integrated optics has the potential to simplify the mechanics of CPV systems by loosening or eliminating the need for dual-axis tracking. In a tracking-integrated scheme, external module tracking is complemented or entirely replaced by miniature tracking within the module. This internal tracking-integration may take the form of active small-motion translation, rotation of arrayed optics, or by passive material property changes induced by the concentrated light. These methods are briefly reviewed. An insolation weighting model is presented which will aid in the design of tracking-integrated optics by quantifying the tradeoff between angular operation range and annual sunlight collection. We demonstrate that when tracking-integrated optics are used to complement external module tracking about a horizontal, North-South oriented axis, truncating the operational range may be advantageous. At Tucson AZ latitude (32.2°N), 15.6% of the angular range may be truncated while only sacrificing 3.6% of the annual insolation. We show that modules tracked about a polar-aligned axis are poorly-suited for truncation.

  6. Tracking heat flux sensors for concentrating solar applications

    DOEpatents

    Andraka, Charles E; Diver, Jr., Richard B

    2013-06-11

    Innovative tracking heat flux sensors located at or near the solar collector's focus for centering the concentrated image on a receiver assembly. With flux sensors mounted near a receiver's aperture, the flux gradient near the focus of a dish or trough collector can be used to precisely position the focused solar flux on the receiver. The heat flux sensors comprise two closely-coupled thermocouple junctions with opposing electrical polarity that are separated by a thermal resistor. This arrangement creates an electrical signal proportional to heat flux intensity, and largely independent of temperature. The sensors are thermally grounded to allow a temperature difference to develop across the thermal resistor, and are cooled by a heat sink to maintain an acceptable operating temperature.

  7. Characteristics of concentration-inhibition curves of individual chemicals and applicability of the concentration addition model for mixture toxicity prediction.

    PubMed

    Wang, Na; Wang, Xiaochang C; Ma, Xiaoyan

    2015-03-01

    The concentration addition (CA) model has been widely applied to predict mixture toxicity. However, its applicability is difficult to evaluate due to the complexity of interactions among substances. Considering that the concentration-response curve (CRC) of each component of the mixture is closely related to the prediction of mixture toxicity, mathematical treatments were used to derive a characteristic index kECx (k was the slope of the tangent line of a CRC at concentration ECx). The implication is that the CA model would be applicable for predicting the mixture toxicity only when chemical components have similar kECx in the whole or part of the concentration range. For five selected chemicals whose toxicity was detected using luminescent bacteria, sodium dodecyl benzene sulfonate (SDBS) showed much higher kECx values than the others and its existence in the binary mixtures brought about overestimation of the mixture toxicity with the CA model. The higher the mass ratio of SDBS in a multi-mixture was, the more the toxicity prediction deviated from measurements. By applying the method proposed in this study to analyze some published data, it is confirmed that some components having significantly different kECx values from the other components could explain the large deviation of the mixture toxicity predicted by the CA model. PMID:25499050

  8. Compact concentric ring shaped antenna for ultra wide band applications

    NASA Astrophysics Data System (ADS)

    Singha, Rahul; Vakula, D.; Sarma, N. V. S. N.

    2014-10-01

    A novel antenna for compact size, simple structure suitable for low cost fabrication is proposed for UWB application. A compact ring shaped monopole antenna is designed to cover the entire ultra wide bandwidth which has straight forward printed circuit board integration. The dimensions of the antenna are 16mm × 12mm × 0.787mm. More specifically, the impedance matching of the antenna is improved by employment of the tapered microstrip feed line. The measurement and simulation results show that the proposed antenna achieves good impedance bandwidth from 6.5 GHz to 25 GHz which covers the entire UWB. The antenna also has a gain approximately 2.5dBi from 6 GHz to 22 GHz. Compared to the existing UWB antennas, the presented modified structure has the smallest size, the widest bandwidth and better return loss characteristics.

  9. Applications of ultraviolet light in the preparation of platelet concentrates

    SciTech Connect

    Pamphilon, D.H.; Corbin, S.A.; Saunders, J.; Tandy, N.P.

    1989-06-01

    Passenger lymphocytes in platelet concentrates (PCs) may induce the formation of lymphocytotoxic antibodies (LCTAbs) and subsequent refractoriness to platelet transfusions. Ultraviolet (UV) irradiation can prevent lymphocytes' acting as stimulator or responder cells in mixed-lymphocyte reactions (MLRs) and could theoretically prevent LCTAb formation in vivo. A system has been devised for the delivery of UV irradiation to PCs; platelet storage characteristics and MLRs were evaluated in UV-irradiated PCs harvested from healthy donors with the Haemonetics V50 and PCS cell separators. MLR and response to phytohemagglutinin stimulation were abolished by a dose of 3000 joules per m2 at a mean wavelength of 310 nm. Platelet aggregatory responses to adenosine diphosphate (ADP), ristocetin, collagen and epinephrine, hypotonic shock response, and pH showed no important differences when control PCs and PCs irradiated as above were compared during 5 days of storage in Fenwal PL-1240 packs. Lactate production during storage was significantly higher in UV-treated PCs (p less than 0.001), but values did not exceed 20 mmol per L. UV transmission at 310 nm in standard blood product containers, including the Fenwal PL-146, PL-1240, and PL-732, was low (less than 30%), but it was acceptable in the Delmed Cryostorage and DuPont SteriCell packs (greater than 50%). UV irradiation may provide a simple and inexpensive means of producing nonimmunogenic PCs.

  10. A novel application of concentrated solar thermal energy in foundries.

    PubMed

    Selvaraj, J; Harikesavan, V; Eshwanth, A

    2016-05-01

    Scrap preheating in foundries is a technology that saves melting energy, leading to economic and environmental benefits. The proposed method in this paper utilizes solar thermal energy for preheating scrap, effected through a parabolic trough concentrator that focuses sunlight onto a receiver which carries the metallic scrap. Scraps of various thicknesses were placed on the receiver to study the heat absorption by them. Experimental results revealed the pattern with which heat is gained by the scrap, the efficiency of the process and how it is affected as the scrap gains heat. The inferences from them gave practical guidelines on handling scraps for best possible energy savings. Based on the experiments conducted, preheat of up to 160 °C and a maximum efficiency of 70 % and a minimum efficiency of 40 % could be achieved across the time elapsed and heat gained by the scrap. Calculations show that this technology has the potential to save around 8 % of the energy consumption in foundries. Cumulative benefits are very encouraging: 180.45 million kWh of energy savings and 203,905 t of carbon emissions cut per year across the globe. This research reveals immense scope for this technology to be adopted by foundries throughout the world. PMID:26208658

  11. Optoelectronic sensor device for monitoring ethanol concentration in winemaking applications

    NASA Astrophysics Data System (ADS)

    Jiménez-Márquez, F.; Vázquez, J.; Úbeda, J.; Rodríguez-Rey, J.; Sánchez-Rojas, J. L.

    2015-05-01

    The supervision of key variables such as sugar, alcohol, released CO2 and microbiological evolution in fermenting grape must is of great importance in the winemaking industry. However, the fermentation kinetics is assessed by monitoring the evolution of the density as it varies during a fermentation, since density is an indicator of the total amount of sugars, ethanol and glycerol. Even so, supervising the fermentation process is an awkward and non-comprehensive task, especially in wine cellars where production rates are massive, and enologists usually measure the density of the extracted samples from each fermentation tank manually twice a day. This work aims at the design of a fast, low-cost, portable and reliable optoelectronic sensor for measuring ethanol concentration in fermenting grape must samples. Different sets of model solutions, which contain ethanol, fructose, glucose, glycerol dissolved in water and emulate the grape must composition at different stages of the fermentation, were prepared both for calibration and validation. The absorption characteristics of these model solutions were analyzed by a commercial spectrophotometer in the NIR region, in order to identify key wavelengths from which valuable information regarding the sample composition can be extracted. Finally, a customized optoelectronic prototype based on absorbance measurements at two wavelengths belonging to the NIR region was designed, fabricated and successfully tested. The system, whose optoelectronics is reduced after a thorough analysis to only two LED lamps and their corresponding paired photodiodes operating at 1.2 and 1.3 μm respectively, calculates the ethanol content by a multiple linear regression.

  12. Conceptual design study of concentrator enhanced solar arrays for space applications Volume 2: Technical

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Concentrator concepts which utilize Kapton mirror material were evaluated and selected for solar array use due to their zero mass. All concepts considered employed thin silicon solar cells. Design requirements for the concentrator were: the cell temperature was not to exceed 150 C; the concentrators were to produce illumination of the array within 15% of being perfectly uniform; the concentrators were to operate while misaligned as much as 5 degrees with the solar axis. Concentrator designs along with mirror structure and configurations are discussed and comparisons are made for optimal space applications.

  13. Method for calculating the three-dimensional water concentration coefficients and its industrial applications

    NASA Astrophysics Data System (ADS)

    Prel, P.

    1991-12-01

    A three dimensional method for calculating the concentration coefficients of water droplets, its general principles, as well as the details of the calculating computer programs that were used, are described. The applications are presented for locating probes on the Airbus 340 and ATR 72 airplanes, mainly showing the effect of the drop diameter on the measured concentration.

  14. Event based analysis of chlorothalonil concentrations following application to managed turf.

    PubMed

    King, Kevin W; Balogh, James C

    2013-03-01

    Chlorothalonil concentrations exceeding acute toxicity levels for certain organisms have been measured in surface water discharge events from managed turf watersheds. The duration of exceedence and the timing of these events related to precipitation/runoff and time since application, however, have not been explored. Chlorothalonil concentrations were measured from discharge waters draining a managed turf watershed in Duluth, Minnesota, USA, between 2003 and 2009. The median chlorothalonil concentration was 0.58 µg/L. Approximately 2% of all measured concentrations exceeded the 7.6 µg/L median lethal concentration (LC50) acute toxicity level for rainbow trout. One-twentieth the LC50 concentration, equivalent to the level of concern (0.38 µg/L) for endangered species, was exceeded 31% of the time during the present study. The concentrations that exceeded the LC50 threshold were associated with eight rainfall/runoff events. Low dose exposures are a more important biological concern than acute occurrences. Exceedence concentrations associated with acute effects were significantly (p < 0.05) correlated to time since application and were measured only in the fall following extensive application. A conflict exists between the transportability of chlorothalonil as suggested by its chemical properties and the data collected in the present study. With respect to course-wide golf course application, avoiding application until after the major autumn rainfall period but before the first snow coverage is recommended to reduce occurrence of chlorothalonil concentrations that exceed toxic levels associated with acute and chronic levels of concern. PMID:23233324

  15. Broiler skin color as affected by organic acids: influence of concentration and method of application.

    PubMed

    Bilgili, S F; Conner, D E; Pinion, J L; Tamblyn, K C

    1998-05-01

    Color of broiler skin was evaluated after exposure to organic acids under various concentrations and simulated potential plant application conditions. Breast skin from chilled broiler carcasses was treated with acetic (AA), citric (CA), lactic (LA), malic (ML), mandelic (MN), propionic (PA), or tartaric (TA) acids at 0.5, 1, 2, 4, and 6% concentrations. Each acid and concentration was applied in simulated dip (23 C for 15 s), scalder (50 C for 2 min), and immersion chiller (1 C for 60 min) conditions. A tap water control was included with each application method. Objective color values of L* (lightness), a* (redness), and b* (yellowness) were measured before and after the treatments to calculate color differentials under a factorial arrangement of organic acids and concentrations. Skin lightness increased (P < 0.01) in simulated chiller as compared to dip and scalder applications. Skin redness was reduced significantly in scalder, and yellowness in dip and scalder applications, respectively. In simulated dip application, with the exception of PA, all acids decreased lightness and increased redness and yellowness values. Propionic acid had little affect on lightness and redness values, but decreased yellowness values. In simulated scalder application, with the exception of PA, all acids decreased lightness with increasing concentration. The redness values changed little in scalder application. However, yellowness values were increased with all acids, except for PA, which decreased yellowness values. In simulated chiller conditions, all acids, except for PA, decreased lightness and redness and increased yellowness values. Propionic acid increased lightness and decreased yellowness values significantly in chiller conditions. Alterations in skin color should be taken into account in the selection and application of organic acids as carcass disinfectants. PMID:9603365

  16. Design, Fabrication and Test of a High Efficiency Refractive Secondary Concentrator for Solar Applications

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.; Geng, Steven M.; Castle, Charles H.; Macosko, Robert P.

    2000-01-01

    Common to many of the space applications that utilize solar thermal energy such as electric power conversion, thermal propulsion, and furnaces, is a need for highly efficient, solar concentration systems. An effort is underway to develop the refractive secondary concentrator, which uses refraction and total internal reflection to efficiently concentrate and direct solar energy. When used in combination with advanced primary concentrators, the refractive secondary concentrator enables very high system concentration ratios (10,000 to 1) and very high temperatures (greater than 2000 K). Presented is an overview of the effort at the NASA Glenn Research Center to evaluate the performance of a prototype single crystal sapphire refractive secondary concentrator and to compare the performance with analytical models. The effort involves the design and fabrication of a secondary concentrator, design and fabrication of a calorimeter and its support hardware, calibration of the calorimeter, testing of the secondary concentrator in NASA Glenn's Tank 6 solar thermal vacuum facility, and comparing the test results with predictions. Test results indicate an average throughput efficiency of 87%. It is anticipated that reduction of a known reflection loss with an anti-reflective coating would result in a secondary concentrator throughput efficiency of approximately 93%.

  17. Single-junction solar cells with the optimum band gap for terrestrial concentrator applications

    DOEpatents

    Wanlass, Mark W.

    1994-01-01

    A single-junction solar cell having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of "pinning" the optimum band gap for a wide range of operating conditions at a value of 1.14.+-.0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap.

  18. A new optical concentrator design and analysis for rooftop solar applications

    NASA Astrophysics Data System (ADS)

    Zheng, Cheng; Li, Qiyuan; Rosengarten, Gary; Hawkes, Evatt; Taylor, Robert A.

    2015-08-01

    In this paper, a new type of linear focus, linear-tracking, catadioptric concentrator system is proposed and analysed for roof-integrated solar thermal applications. The optical concentrator designs have a focal distance of less than 10cm and are analysed using optical simulation software (Zemax). The results show that a relatively high concentration ratio (4.5 ~ 5.9 times) can be obtained and that the concentrators are capable of achieving an average optical efficiency around 66 - 69% during the middle 6 hours of a sunny day (i.e. a day with ~1000W/m2 global irradiance). Optical efficiency is analysed for perfect and non-ideal optical components to predict the collector performance under different `practical' circumstances. Overall, we intend for this paper to catalyse the development of rooftop solar thermal concentrators with compact form factors, similar to PV panels.

  19. Formation of titanate nanostructures under different NaOH concentration and their application in wastewater treatment

    SciTech Connect

    Huang Jiquan; Cao Yongge; Deng Zhonghua; Tong Hao

    2011-03-15

    The effects of the concentration of NaOH on the formation and transformation of various titanate nanostructures were studied. With increasing NaOH concentration, three different formation mechanisms were proposed. Nanotubes can only be obtained under moderate NaOH conditions, and should transform into nanowires with prolonged hydrothermal treatment, and their formation rate is accelerated by increasing NaOH concentration. Low concentration of NaOH results in the direct formation of nanowires, while extra high concentration of NaOH leads to the formation of amorphous nanoparticles. Adsorption and photocatalysis studies show that titanate nanowires and nanotubes might be potential adsorbents for the removal of both heavy metal ions and dyes and photocatalysts for the removal of dyes from wastewater. -- Graphical abstract: The morphologies of the titanates depend deeply on the concentration of NaOH. With increasing NaOH concentration, three different formation mechanisms were proposed. The application of these titanate nanostructures in the wastewater treatment was studied. Display Omitted Research highlights: {yields} Effect of NaOH concentration on the structures of various titanates was reported. {yields} Three different formation mechanisms were presented with increasing NaOH concentration. {yields} Various titanates were used as adsorbents/photocatalysts in wastewater treatment.

  20. Convection-diffusion driven concentration gradients in nanolitre droplets for microfluidic screening applications

    NASA Astrophysics Data System (ADS)

    Thakur, Raviraj; Amin, Ahmed; Wereley, Steven

    2014-11-01

    Ability to generate a concentration gradients in emulsified aqueous droplets is a highly desired feature for several lab-on-chip applications. Numerous schemes exists for generating concentration gradients in continuous flow devices such as Y junctions, split-and-recombine techniques, etc. However, varying the sample concentration in emulsified droplets is quite challenging. In this work, we have developed a scheme for generating and controlling concentration gradients in programmable multi-layer PDMS microfluidic chips. Briefly, a high concentration sample is injected into a steady stream of buffer. The buffer with the sample pulse and an immiscible oil phase are flowed through a T-junction in an alternate manner. As the sample pulse advances, the combined effect of diffusion and convection produced dispersion of sample pulse in streamwise direction. This continuous gradient stream is split into discrete droplets at the T-junction. Pulsatile flow condition are maintained using on-chip diaphragm peristaltic pumps. The problem can be thought of an extension of Taylor-Aris dispersion with laminar pulsatile flow in rectangular channels. The concentration profile is found to be dependent upon the frequency of pulsatile flow and thus can be fine-tuned according to application needs. Theoretical framework is established for pump regimes that correlates the diffusion coefficients of the input samples with the resultant concentration profiles.

  1. Preadmission Application of 2% Chlorhexidine Gluconate (CHG): Enhancing Patient Compliance While Maximizing Skin Surface Concentrations.

    PubMed

    Edmiston, Charles E; Krepel, Candace J; Spencer, Maureen P; Ferraz, Alvaro A; Seabrook, Gary R; Lee, Cheong J; Lewis, Brian D; Brown, Kellie R; Rossi, Peter J; Malinowski, Michael J; Edmiston, Sarah E; Ferraz, Edmundo M; Leaper, David J

    2016-03-01

    OBJECTIVE Surgical site infections (SSIs) are responsible for significant morbidity and mortality. Preadmission skin antisepsis, while controversial, has gained acceptance as a strategy for reducing the risk of SSI. In this study, we analyze the benefit of an electronic alert system for enhancing compliance to preadmission application of 2% chlorhexidine gluconate (CHG). DESIGN, SETTING, AND PARTICIPANTS Following informed consent, 100 healthy volunteers in an academic, tertiary care medical center were randomized to 5 chlorhexidine gluconate (CHG) skin application groups: 1, 2, 3, 4, or 5 consecutive applications. Participants were further randomized into 2 subgroups: with or without electronic alert. Skin surface concentrations of CHG (μg/mL) were analyzed using a colorimetric assay at 5 separate anatomic sites. INTERVENTION Preadmission application of chlorhexidine gluconate, 2% RESULTS Mean composite skin surface CHG concentrations in volunteer participants receiving EA following 1, 2, 3, 4, and 5 applications were 1,040.5, 1,334.4, 1,278.2, 1,643.9, and 1,803.1 µg/mL, respectively, while composite skin surface concentrations in the no-EA group were 913.8, 1,240.0, 1,249.8, 1,194.4, and 1,364.2 µg/mL, respectively (ANOVA, P<.001). Composite ratios (CHG concentration/minimum inhibitory concentration required to inhibit the growth of 90% of organisms [MIC90]) for 1, 2, 3, 4, or 5 applications using the 2% CHG cloth were 208.1, 266.8, 255.6, 328.8, and 360.6, respectively, representing CHG skin concentrations effective against staphylococcal surgical pathogens. The use of an electronic alert system resulted in significant increase in skin concentrations of CHG in the 4- and 5-application groups (P<.04 and P<.007, respectively). CONCLUSION The findings of this study suggest an evidence-based standardized process that includes use of an Internet-based electronic alert system to improve patient compliance while maximizing skin surface concentrations effective

  2. Artificial neural network estimation of soil erosion and nutrient concentrations in runoff from land application areas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The transport of sediment and nutrients from land application areas is an environmental concern. New methods are needed for estimating soil and nutrient concentrations of runoff from cropland areas on which manure is applied. Artificial Neural Networks (ANN) trained with a Backpropagation (BP) algor...

  3. Abscisic acid form, concentration, and application timing influence phenology and bud cold hardiness in Merlot grapevines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of abscisic acid (ABA) form, concentration and application timing on bud cold hardiness, phenology and fruiting performance on ‘Merlot’ grapevines (Vitis vinifera) were evaluated in a three year field trial with site locations in British Columbia Canada, Ontario Canada, Washington U.S. ...

  4. MATING DISRUPTION OF THE ORIENTAL FRUIT MOTH BY CONCENTRATED APPLICATIONS OF MICROENCAPSULATED PHEROMONE IN TURKEY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficacy of ultra low-volume, concentrated applications of a microencapsulated sex pheromone formulation for the Oriental fruit moth (OFM) Grapholita molesta (Busck) was evaluated in 2006. Large plots, 4 ha for each treatment, were established at two locations near Bursa, northwestern Turkey. Th...

  5. Event based analysis of Chlorothalonil concentrations following application to managed turf

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chlorothalonil concentrations exceeding acute toxicity levels for certain organisms have been measured in surface water discharge events from managed turf watersheds. However, the duration of exceedence and the timing of those events with respect to precipitation/runoff and time since application ha...

  6. Field Evaluations of Concentrated Spray Applications of Microencapsulated Sex Pheromone for Codling Moth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The application of a microencapsulated (MEC) sex pheromone formulation (Checkmate® CM-F) for codling moth, Cydia pomonella (L.), in low volume, concentrated sprays was evaluated in a series of small plot and grower trials in apple and pear. Preliminary tests found that MEC sprays applied at 172-207 ...

  7. 40 CFR 417.40 - Applicability; description of the glycerine concentration subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 29 2014-07-01 2012-07-01 true Applicability; description of the glycerine concentration subcategory. 417.40 Section 417.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT...

  8. 40 CFR 417.40 - Applicability; description of the glycerine concentration subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 30 2013-07-01 2012-07-01 true Applicability; description of the glycerine concentration subcategory. 417.40 Section 417.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT...

  9. 40 CFR 417.40 - Applicability; description of the glycerine concentration subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 30 2012-07-01 2012-07-01 false Applicability; description of the glycerine concentration subcategory. 417.40 Section 417.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT...

  10. 40 CFR 417.40 - Applicability; description of the glycerine concentration subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 29 2011-07-01 2009-07-01 true Applicability; description of the glycerine concentration subcategory. 417.40 Section 417.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT...

  11. 40 CFR 417.40 - Applicability; description of the glycerine concentration subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Applicability; description of the glycerine concentration subcategory. 417.40 Section 417.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT...

  12. Electrical characterization of electrophoretically coated aluminum samples for photovoltaic concentrator application

    SciTech Connect

    Sugimura, R.S.; Mon, G.R.; Ross, R.G. Jr.

    1992-10-01

    The practicality of using a thin-film styrene/acrylate copolymer electrophoretic coating to isolate concentrator cells electrically from their surroundings in a photovoltaic concentrator module is assessed. Only the electrical isolation problem was investigated. The approach was to subject various types of EP-coated aluminum specimens to electrical stress testing and to aging tests while monitoring coating electrical resistivity properties. It was determined that, in general, longer processing times--i.e., thicker electrophoretic layers--resulted in better voltage-withstand properties. In particular, a two-minute processing time seemed sufficient to provide the electrical isolation required in photovoltaic concentrator application applications. Even though electrophoretic coatings did not seem to fill voids in porous-anodized aluminum substrates, breakdown voltages generally exceeded hi-pot pass-fail voltage levels with a comfortable margin. 6 refs, 11 figs, 5 tabs.

  13. 64 kW concentrator Photovoltaics Application Test Center. Volume. Final report

    SciTech Connect

    Jardine, D.M.; Jones, D.W.

    1980-06-01

    Kaman Sciences Corporation has designed a 64 kW Concentrating Photovoltaic Applications Test Center (APTEC). The APTEC employs a combined concentrating photovoltaic array in a total energy system application for load sharing the electric and thermal demands of a large computer center with the interfaced electric and natural gas utility. The photovoltaic array is composed of two-axis tracking heliostats of Fresnel lens concentrating, silicon solar cell modules. The modules are cooled with a fluid which transfers heat to a ground coupled heat sink/storage unit for subsequent use in meeting the computer center's thermal load demand. The combined photovoltaic power system shares basic components - a power conditioning unit, batteries and thermal conditioning equipment - with the electric and natural gas utility service, improving the computer center's operating availability time and displacing a portion of the fossil fuel required to power the computer center with solar energy. The detailed system design is reported.

  14. A High-Efficiency Refractive Secondary Solar Concentrator for High Temperature Solar Thermal Applications

    NASA Technical Reports Server (NTRS)

    Piszczor, Michael F., Jr.; Macosko, Robert P.

    2000-01-01

    A refractive secondary solar concentrator is a non-imaging optical device that accepts focused solar energy from a primary concentrator and redirects that light, by means of refraction and total internal reflection (TIR) into a cavity where the solar energy is used for power and/or propulsion applications. This concept offers a variety of advantages compared to typical reflective secondary concentrators (or the use of no secondary at all): higher optical efficiency, minimal secondary cooling requirements, a smaller cavity aperture, a reduction of outgassing from the cavity and flux tailoring of the solar energy within the heat receiver. During the past 2 years, NASA Lewis has been aggressively developing this concept in support of the NASA Marshall Shooting Star Flight Experiment. This paper provides a brief overview of the advantages and technical challenges associated with the development of a refractive secondary concentrator and the fabrication of a working unit in support of the flight demonstration program.

  15. Single-junction solar cells with the optimum band gap for terrestrial concentrator applications

    DOEpatents

    Wanlass, M.W.

    1994-12-27

    A single-junction solar cell is described having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of ''pinning'' the optimum band gap for a wide range of operating conditions at a value of 1.14[+-]0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap. 7 figures.

  16. Biomass and nutrient concentration of sweet corn roots and shoots under organic amendments application.

    PubMed

    Ahmad, Amjad A; Fares, Ali; Paramasivam, Sivapatham; Elrashidi, Moustafa A; Savabi, Reza M

    2009-09-01

    Two field experiments were conducted at the Waimanalo research station on the island of O'ahu, Hawaii to study the effect of chicken (CM) and dairy (DM) manures on biomass and nutrient concentration in sweet corn roots and shoots. Sweet corn (super sweet 10, Zea Mays L. subsp. mays) was grown for two consecutive growing seasons under four rates of application (0, 168, 337, and 672 kg ha(-1) total N equivalent) and one time (OTA) or two time (TTA) applications of organic manure types and rates. There were significant effects of types, rates, and number of manure applications on dry biomass and macro- and micro-nutrient concentration in roots and shoots tissues. Results of root tissue indicated a significant accumulation of N and C under CM and DM treatments compared with the control treatment. Manure application rates significantly increased the accumulation of N and C in root tissue. Dry weight of roots and shoots and both macro- and micro-nutrient contents in the plant tissues significantly increased under TTA treatment compared with OTA treatment. There was a significant correlation (r(2) = 0.46 to 0.81) between root biomass, macro-, and micro-nutrient contents during both growing seasons. The results of the study indicates that amending soils with CM at the highest application rate provided the best crop performance in terms of root and shoot biomass, crop N, C, and other macro- and micro-nutrients. PMID:20183085

  17. Extraordinary acoustic transmission through annuluses in air and its applications in acoustic beam splitter and concentrator

    NASA Astrophysics Data System (ADS)

    Ge, Yong; Sun, Hong-xiang; Liu, Shu-sen; Yuan, Shou-qi; Xia, Jian-ping; Guan, Yi-jun; Zhang, Shu-yi

    2016-08-01

    We report an extraordinary acoustic transmission through two layer annuluses made of metal cylinders in air both numerically and experimentally. The effect arises from the enhancement and reconstruction of the incident source induced by different Mie-resonance modes of the annuluses. The proposed system takes advantages of the consistency in the waveform between the input and output waves, the high amplitude amplification of output waves, and the easy adjustment of structure. More interestingly, we investigate the applications of the extraordinary acoustic transmission in the acoustic beam splitter and acoustic concentrator. Our finding should have an impact on ultrasonic applications.

  18. Extraordinary acoustic transmission through annuluses in air and its applications in acoustic beam splitter and concentrator.

    PubMed

    Ge, Yong; Sun, Hong-Xiang; Liu, Shu-Sen; Yuan, Shou-Qi; Xia, Jian-Ping; Guan, Yi-Jun; Zhang, Shu-Yi

    2016-08-01

    We report an extraordinary acoustic transmission through two layer annuluses made of metal cylinders in air both numerically and experimentally. The effect arises from the enhancement and reconstruction of the incident source induced by different Mie-resonance modes of the annuluses. The proposed system takes advantages of the consistency in the waveform between the input and output waves, the high amplitude amplification of output waves, and the easy adjustment of structure. More interestingly, we investigate the applications of the extraordinary acoustic transmission in the acoustic beam splitter and acoustic concentrator. Our finding should have an impact on ultrasonic applications. PMID:27587144

  19. The United Stirling P40 engine for solar dish concentrator application

    NASA Technical Reports Server (NTRS)

    Ortegren, L.; Sjostedt, L. E.

    1980-01-01

    The United Stirling P40 engine is a key component in a solar concentration based energy conversion system, to be demonstrated and tested during 1980-81. The inherent characteristics of modern Stirling engines is reviewed focusing on the baseline P40 double-acting engine. The extent of modifications required for the solar application is reviewed and performance data are predicted. Finally, the potential of an advanced solar Stirling engine is briefly considered.

  20. Design and economics of a photovoltaic concentrator array for off-grid applications

    NASA Astrophysics Data System (ADS)

    Maish, A. B.; Rios, M., Jr.

    1982-09-01

    The array design and expected operation of a photovoltaic concentrator are discussed. A second generation stand alone 680 W/sub p/ photovoltaic (PV) concentrating array for low power, nongrid connected applications was designed. The array consists of six passive cooled point focus Fresnel lens concentrating modules on a two axis polar mount tracking structure. The new array design incorporates several major improvements to the first generation design. These include 50% more array area and a control system which allows unattended, fully automatic operation. The life cycle energy costs are calculated and compared to the equivalent energy costs of a 3 kW diesel electric generator set and an equivalent flat panel PV system.

  1. Mathematical model to predict skin concentration after topical application of drugs.

    PubMed

    Todo, Hiroaki; Oshizaka, Takeshi; Kadhum, Wesam R; Sugibayashi, Kenji

    2013-01-01

    Skin permeation experiments have been broadly done since 1970s to 1980s as an evaluation method for transdermal drug delivery systems. In topically applied drug and cosmetic formulations, skin concentration of chemical compounds is more important than their skin permeations, because primary target site of the chemical compounds is skin surface or skin tissues. Furthermore, the direct pharmacological reaction of a metabolically stable drug that binds with specific receptors of known expression levels in an organ can be determined by Hill's equation. Nevertheless, little investigation was carried out on the test method of skin concentration after topically application of chemical compounds. Recently we investigated an estimating method of skin concentration of the chemical compounds from their skin permeation profiles. In the study, we took care of "3Rs" issues for animal experiments. We have proposed an equation which was capable to estimate animal skin concentration from permeation profile through the artificial membrane (silicone membrane) and animal skin. This new approach may allow the skin concentration of a drug to be predicted using Fick's second law of diffusion. The silicone membrane was found to be useful as an alternative membrane to animal skin for predicting skin concentration of chemical compounds, because an extremely excellent extrapolation to animal skin concentration was attained by calculation using the silicone membrane permeation data. In this chapter, we aimed to establish an accurate and convenient method for predicting the concentration profiles of drugs in the skin based on the skin permeation parameters of topically active drugs derived from steady-state skin permeation experiments. PMID:24351574

  2. Effects of concentration, distance, and application methods of Altriset (Chlorantraniliprole) on eastern subterranean termite (Isoptera: Rhinotermitidae).

    PubMed

    Barwary, Znar; Gorzlancyk, Austin; Hu, Xing Ping

    2015-03-01

    The effects of various concentrations, distance, and application methods of Altriset (Chlorantraniliprole) were investigated against one of the most destructive termites, the eastern subterranean termite, Reticulitermes flavipes Kollar. Three laboratory experiments were conducted. First, we examined the concentration effect of treating the soil contiguously to established foraging tunnels at a fixed 1 m distance. The results demonstrated 100% termite control in 19 d posttreatment at 100 and 50 μg/g and 27% termite mortality at 25 μg/g. Second, we tested the distance effect of the soil treatment (2 and 4 m) on the efficacy of Altriset to the satellite termite populations at a fixed 50 μg/g concentration. This resulted in 100% termite control in 22 d posttreatment at both 2 and 4 m. Third, we examined the effect of differing application methods using 12.5 and 25 μg/g prior to the establishment of foraging tunnels at a fixed 1m distance. This illustrated 100% termite control in 9 d posttreatment at 25 μg/g and 12 d posttreatment at 12.5 μg/g. The third experiment demonstrated soil treatments that were applied prior to termite tunnel establishment had greater efficacy than applications made post tunnel construction. Our results provide a comprehensive understanding about the efficacy of Altriset treatments on eastern subterranean termites. PMID:24623649

  3. Xylitol concentrations in artificial saliva after application of different xylitol dental varnishes

    PubMed Central

    PEREIRA, Agnes de Fátima Faustino; da SILVA, Thiago Cruvinel; da SILVA, Thelma Lopes; CALDANA, Magali de Lourdes; BASTOS, José Roberto Magalhães; BUZALAF, Marília Afonso Rabelo

    2012-01-01

    Objective The present study analyzed xylitol concentrations in artificial saliva over time after application of varnishes containing 10% and 20% xylitol. Material and Methods Fifteen bovine enamel specimens (8x4 mm) were randomly allocated to 3 groups (n=5/group), according to the type of varnish used: 10% xylitol, 20% xylitol and no xylitol (control). After varnish application (4 mg), specimens were immersed in vials containing 500 µL of artificial saliva. Saliva samples were collected in different times (1, 8, 12, 16, 24, 48 and 72 h) and xylitol concentrations were analyzed. Data were assessed by two-way repeated-measures ANOVA (p<0.05). Results Colorimetric analysis was not able to detect xylitol in saliva samples of the control group. Salivary xylitol concentrations were significantly higher up to 8 h after application of the 20% xylitol varnish. Thereafter, the 10% xylitol varnish released larger amounts of that polyol in artificial saliva. Conclusions Despite the results in short-term, sustained xylitol releases could be obtained when the 10% xylitol varnish was used. These varnishes seem to be viable alternatives to increase salivary xylitol levels, and therefore, should be clinically tested to confirm their effectiveness. PMID:22666828

  4. Potential Applications of Concentrated Solar Thermal Technologies in the Australian Minerals Processing and Extractive Metallurgical Industry

    NASA Astrophysics Data System (ADS)

    Eglinton, Thomas; Hinkley, Jim; Beath, Andrew; Dell'Amico, Mark

    2013-12-01

    The Australian minerals processing and extractive metallurgy industries are responsible for about 20% of Australia's total greenhouse gas (GHG) emissions. This article reviews the potential applications of concentrated solar thermal (CST) energy in the Australian minerals processing industry to reduce this impact. Integrating CST energy into these industries would reduce their reliance upon conventional fossil fuels and reduce GHG emissions. As CST technologies become more widely deployed and cheaper, and as fuel prices rise, CST energy will progressively become more competitive with conventional energy sources. Some of the applications identified in this article are expected to become commercially competitive provided the costs for pollution abatement and GHG mitigation are internalized. The areas of potential for CST integration identified in this study can be classed as either medium/low-temperature or high-temperature applications. The most promising medium/low-grade applications are electricity generation and low grade heating of liquids. Electricity generation with CST energy—also known as concentrated solar power—has the greatest potential to reduce GHG emissions out of all the potential applications identified because of the 24/7 dispatchability when integrated with thermal storage. High-temperature applications identified include the thermal decomposition of alumina and the calcination of limestone to lime in solar kilns, as well as the production of syngas from natural gas and carbonaceous materials for various metallurgical processes including nickel and direct reduced iron production. Hybridization and integration with thermal storage could enable CST to sustain these energy-intensive metallurgical processes continuously. High-temperature applications are the focus of this paper.

  5. Contaminants of emerging concern in reverse osmosis brine concentrate from indirect/direct water reuse applications.

    PubMed

    Romeyn, Travis R; Harijanto, Wesley; Sandoval, Sofia; Delagah, Saied; Sharbatmaleki, Mohamadali

    2016-01-01

    Water shortage is becoming more common due to droughts and global population increases resulting in the increasing popularity of water reuse to create new water sources. Reverse osmosis (RO) membrane systems are popular in these applications since they can produce drinking water quality effluent. Unfortunately, RO systems have the drawback of generating concentrate streams that contain contaminants rejected by the membrane including chemicals of emerging concern (CECs). CECs are chemicals such as hormones, steroids, pesticides, pharmaceuticals, and personal care products that are used for their intended purpose and then released into wastewater. CECs are believed to be detrimental to aquatic wildlife health and pose an unknown human health risk. This research gathered the existing knowledge on CEC presence in concentrate, available proven concentrate treatment methods, their CEC removal abilities, and current CEC regulations. It was found that 127 CECs have been measured in RO concentrate with 100 being detected at least once. The most potent treatment process available is UV/H2O2 as it offers the highest removal rates for the widest range of chemicals. The less expensive process of ozone/biologically activated carbon offers slightly lower removal abilities. This comprehensive report will provide the groundwork for better understanding, regulating and treating concentrate stream CECs. PMID:26819378

  6. Exploration of the horizontally staggered light guides for high concentration CPV applications.

    PubMed

    Selimoglu, Ozgur; Turan, Rasit

    2012-08-13

    The material and processing costs are still the major drawbacks of the c-Si based photovoltaic (PV) technology. The wafer cost comprises up to 35-40% of the total module cost. New approaches and system designs are needed in order to reduce the share of the wafer cost in photovoltaic energy systems. Here we explore the horizontally staggered light guide solar optics for use in Concentrated Photovoltaic (CPV) applications. This optical system comprises a lens array system coupled to a horizontal light guide which directs the incoming light beam to its edge. We have designed and simulated this system using a commercial ray tracing software (Zemax). The system is more compact, thinner and more robust compared to the conventional CPV systems. Concentration levels as high as 1000x can easily be reached when the system is properly designed. With such a high concentration level, a good acceptance angle of + -1 degree is still be conserved. The analysis of the system reveals that the total optical efficiency of the system could be as high as %94.4 without any anti-reflection (AR) coating. Optical losses can be reduced by just accommodating a single layer AR coating on the initial lens array leading to a %96.5 optical efficiency. Thermal behavior of high concentration linear concentrator is also discussed and compared with a conventional point focus CPV system. PMID:23038554

  7. Combined dielectrophoretic and impedance system for on-chip controlled bacteria concentration: Application to Escherichia coli.

    PubMed

    Del Moral-Zamora, Beatriz; Punter-Villagrassa, Jaime; Oliva-Brañas, Ana M; Álvarez-Azpeitia, Juan Manuel; Colomer-Farrarons, Jordi; Samitier, Josep; Homs-Corbera, Antoni; Miribel-Català, Pere Ll

    2015-05-01

    The present paper reports a bacteria autonomous controlled concentrator prototype with a user-friendly interface for bench-top applications. It is based on a microfluidic lab-on-a-chip and its associated custom instrumentation, which consists of a dielectrophoretic actuator, to preconcentrate the sample, and an impedance analyzer, to measure concentrated bacteria levels. The system is composed of a single microfluidic chamber with interdigitated electrodes and an instrumentation with custom electronics. The prototype is supported by a real-time platform connected to a remote computer, which automatically controls the system and displays impedance data used to monitor the status of bacteria accumulation on-chip. The system automates the whole concentrating operation. Performance has been studied for controlled volumes of Escherichia coli samples injected into the microfluidic chip at constant flow rate of 10 μL/min. A media conductivity correcting protocol has been developed, as the preliminary results showed distortion of the impedance analyzer measurement produced by bacterial media conductivity variations through time. With the correcting protocol, the measured impedance values were related to the quantity of bacteria concentrated with a correlation of 0.988 and a coefficient of variation of 3.1%. Feasibility of E. coli on-chip automated concentration, using the miniaturized system, has been demonstrated. Furthermore, the impedance monitoring protocol had been adjusted and optimized, to handle changes in the electrical properties of the bacteria media over time. PMID:25752513

  8. 40 CFR 122.24 - Concentrated aquatic animal production facilities (applicable to State NPDES programs, see § 123...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 22 2014-07-01 2013-07-01 true Concentrated aquatic animal production facilities (applicable to State NPDES programs, see § 123.25). 122.24 Section 122.24 Protection of... § 122.24 Concentrated aquatic animal production facilities (applicable to State NPDES programs,...

  9. 40 CFR 122.24 - Concentrated aquatic animal production facilities (applicable to State NPDES programs, see § 123...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 23 2013-07-01 2013-07-01 false Concentrated aquatic animal production facilities (applicable to State NPDES programs, see § 123.25). 122.24 Section 122.24 Protection of... § 122.24 Concentrated aquatic animal production facilities (applicable to State NPDES programs,...

  10. 40 CFR 122.24 - Concentrated aquatic animal production facilities (applicable to State NPDES programs, see § 123...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 23 2012-07-01 2012-07-01 false Concentrated aquatic animal production facilities (applicable to State NPDES programs, see § 123.25). 122.24 Section 122.24 Protection of... § 122.24 Concentrated aquatic animal production facilities (applicable to State NPDES programs,...

  11. Pharmacokinetic Modeling to Simulate the Concentration-Time Profiles After Dermal Application of Rivastigmine Patch.

    PubMed

    Nozaki, Sachiko; Yamaguchi, Masayuki; Lefèvre, Gilbert

    2016-07-01

    Rivastigmine is an inhibitor of acetylcholinesterases and butyrylcholinesterases for symptomatic treatment of Alzheimer disease and is available as oral and transdermal patch formulations. A dermal absorption pharmacokinetic (PK) model was developed to simulate the plasma concentration-time profile of rivastigmine to answer questions relative to the efficacy and safety risks after misuse of the patch (e.g., longer application than 24 h, multiple patches applied at the same time, and so forth). The model comprised 2 compartments which was a combination of mechanistic dermal absorption model and a basic 1-compartment model. The initial values for the model were determined based on the physicochemical characteristics of rivastigmine and PK parameters after intravenous administration. The model was fitted to the clinical PK profiles after single application of rivastigmine patch to obtain model parameters. The final model was validated by confirming that the simulated concentration-time curves and PK parameters (Cmax and area under the drug plasma concentration-time curve) conformed to the observed values and then was used to simulate the PK profiles of rivastigmine. This work demonstrated that the mechanistic dermal PK model fitted the clinical data well and was able to simulate the PK profile after patch misuse. PMID:27212635

  12. 40 CFR 122.24 - Concentrated aquatic animal production facilities (applicable to State NPDES programs, see § 123...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Concentrated aquatic animal production... § 122.24 Concentrated aquatic animal production facilities (applicable to State NPDES programs, see § 123.25). (a) Permit requirement. Concentrated aquatic animal production facilities, as defined in...

  13. 40 CFR 122.24 - Concentrated aquatic animal production facilities (applicable to State NPDES programs, see § 123...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 22 2011-07-01 2011-07-01 false Concentrated aquatic animal production... § 122.24 Concentrated aquatic animal production facilities (applicable to State NPDES programs, see § 123.25). (a) Permit requirement. Concentrated aquatic animal production facilities, as defined in...

  14. Performance and Reliability of Multijunction III-V Modules for Concentrator Dish and Central Receiver Applications

    SciTech Connect

    Verlinden, P. J.; Lewandowski, A.; Bingham, C.; Kinsey, G. S.; Sherif, R. A.; Laisch, J. B.

    2006-01-01

    Over the last 15 years, Solar Systems have developed a dense array receiver PV technology for 500X concentrator reflective dish applications. This concentrator PV technology has been successfully deployed at six different locations in Australia, counting for more than 1 MWp of installed peak power. A new Multijunction III-V receiver to replace the current silicon Point-Contact solar cells has recently been developed. The new receiver technology is based on high-efficiency (>32%) Concentrator Ultra Triple Junction (CUTJ) solar cells from Spectrolab, resulting in system power and energy performance improvement of more than 50% compared to the silicon cells. The 0.235 m{sup 2} concentrator PV receiver, designed for continuous 500X operation, is composed of 64 dense array modules, and made of series and parallel-connected solar cells, totaling approximately 1,500 cells. The individual dense array modules have been tested under high intensity pulsed light, as well as with concentrated sunlight at the Solar Systems research facility and at the National Renewable Energy Laboratory's High Flux Solar Furnace. The efficiency of the dense array modules ranges from 30% to 36% at 500X (50 W/cm{sup 2}, AM1.5D low AOD, 21C). The temperature coefficients for power, voltage and current, as well as the influence of Air Mass on the cell responsivity, were measured. The reliability of the dense array multijunction III-V modules has been studied with accelerated aging tests, such as thermal cycling, damp heat and high-temperature soak, and with real-life high-intensity exposure. The first 33 kWp multijunction III-V receiver was recently installed in a Solar Systems dish and tested in real-life 500X concentrated sunlight conditions. Receiver efficiencies of 30.3% and 29.0% were measured at Standard Operating Conditions and Normal Operating Conditions respectively.

  15. Mechanical design of a low concentration ratio solar array for a space station application

    NASA Technical Reports Server (NTRS)

    Biss, M. S.; Hsu, L.

    1983-01-01

    This paper describes a preliminary study and conceptual design of a low concentration ratio solar array for a space station application with approximately a 100 kW power requirement. The baseline design calls for a multiple series of inverted, truncated, pyramidal optical elements with a geometric concentration ratio (GCR) of 6. It also calls for low life cycle cost, simple on-orbit maintainability, 1984 technology readiness date, and gallium arsenide (GaAs) of silicon (Si) solar cell interchangeability. Due to the large area needed to produce the amount of power required for the baseline space station, a symmetrical wing design, making maximum use of the commonality of parts approach, was taken. This paper will describe the mechanical and structural design of a mass-producible solar array that is very easy to tailor to the needs of the individual user requirement.

  16. A Technique for Rapidly Deploying a Concentration Gradient with Applications to Microgravity

    NASA Technical Reports Server (NTRS)

    Leslie, Fred; Ramachandran, Narayanan

    2000-01-01

    The latter half of the last century has seen rapid advancements in semiconductor crystal growth powered by the demand for high performance electronics in myriad applications. The reduced gravity environment of space has also been used for crystal growth tests, especially in instances where terrestrial growth has largely been unsuccessful. While reduced gravity crystal growth affords some control of the gravity parameter, many crystals grown in space, to date, have structural flaws believed to result from convective motions during the growth phase. The character of these instabilities is not well understood but is associated with thermal and solutal density variations near the solidification interface in the presence of residual gravity and g-jitter. In order to study these instabilities in a separate, controlled space experiment, a concentration gradient would first have to be artificially established in a timely manner as an initial condition. This is generally difficult to accomplish in a microgravity environment because the momentum of the fluid injected into a test cell tends to swirl around and mix in the absence of a restoring force. The use of magnetic fields to control the motion and position of liquids has received growing interest in recent times. The possibility of using the force exerted by a non-uniform magnetic field on a ferrofluid to not only achieve fluid manipulation but also to actively control fluid motion makes it an attractive candidate for space applications. This paper describes a technique for quickly establishing a linear or exponential fluid concentration gradient using a magnetic field in place of gravity to stabilize the deployment. Also discussed is a photometric technique for measuring the concentration profile using light attenuation. Results of the ground-based experiments indicate that the concentration distribution is within 3% of the predicted value. Although any range of concentations can be realized, photometric constraints are

  17. Contact Irritant Responses of Aedes aegypti Using Sublethal Concentration and Focal Application of Pyrethroid Chemicals

    PubMed Central

    Manda, Hortance; Shah, Pankhil; Polsomboon, Suppaluck; Chareonviriyaphap, Theeraphap; Castro-Llanos, Fanny; Morrison, Amy; Burrus, Roxanne G.; Grieco, John P.; Achee, Nicole L.

    2013-01-01

    Background Previous studies have demonstrated contact irritant and spatial repellent behaviors in Aedes aegypti following exposure to sublethal concentrations of chemicals. These sublethal actions are currently being evaluated in the development of a push-pull strategy for Ae. aegypti control. This study reports on mosquito escape responses after exposure to candidate chemicals for a contact irritant focused push-pull strategy using varying concentrations and focal application. Methods Contact irritancy (escape) behavior, knockdown and 24 hour mortality rates were quantified in populations of female Ae. aegypti under laboratory conditions and validated in the field (Thailand and Peru) using experimental huts. Evaluations were conducted using varying concentrations and treatment surface area coverage (SAC) of three pyrethroid insecticides: alphacypermethrin, lambacyhalothrin and deltamethrin. Results Under laboratory conditions, exposure of Ae. aegypti to alphacypermethrin using the standard field application rate (FAR) resulted in escape responses at 25% and 50% SAC that were comparable with escape responses at 100% SAC. Significant escape responses were also observed at <100% SAC using ½FAR of all test compounds. In most trials, KD and 24 hour mortality rates were higher in mosquitoes that did not escape than in those that escaped. In Thailand, field validation studies indicated an early time of exit (by four hours) and 40% increase in escape using ½FAR of alphacypermethrin at 75% SAC compared to a matched chemical-free control. In Peru, however, the maximum increase in Ae. aegypti escape from alphacypermethrin-treated huts was 11%. Conclusions/Significance Results presented here suggest a potential role for sublethal and focal application of contact irritant chemicals in an Ae. aegypti push-pull strategy to reduce human–vector contact inside treated homes. However, the impact of an increase in escape response on dengue virus transmission is currently unknown

  18. Ge doped GaN with controllable high carrier concentration for plasmonic applications

    SciTech Connect

    Kirste, Ronny; Hoffmann, Marc P.; Sachet, Edward; Bobea, Milena; Bryan, Zachary; Bryan, Isaac; Maria, Jon-Paul; Collazo, Ramón; Sitar, Zlatko; Nenstiel, Christian; Hoffmann, Axel

    2013-12-09

    Controllable Ge doping in GaN is demonstrated for carrier concentrations of up to 2.4 × 10{sup 20} cm{sup −3}. Low temperature luminescence spectra from the highly doped samples reveal band gap renormalization and band filling (Burstein-Moss shift) in addition to a sharp transition. Infrared ellipsometry spectra demonstrate the existence of electron plasma with an energy around 3500 cm{sup −1} and a surface plasma with an energy around 2000 cm{sup −1}. These findings open possibilities for the application of highly doped GaN for plasmonic devices.

  19. Development and application of color schlieren technique for investigation of three-dimensional concentration field

    NASA Astrophysics Data System (ADS)

    Srivastava, Atul

    2013-11-01

    The present work describes the development and application of rainbow schlieren deflectometry technique for the investigation of the three-dimensional concentration field around a crystal growing from its aqueous solution. The imaging technique employs a diverging beam of light to record the projection data of the concentration field. In contrast to the conventional schlieren methods, the present system makes use of a microscopic objective lens to act as the de-collimating lens for focusing the light beam onto the color filter to get the desired schlieren effect. In order to record the projection data of the concentration field from different view angles for tomographic reconstruction, the experiments are conducted in an octagonal growth cell. Detailed quantitative analysis of the schlieren images has then been carried out for each view angle to determine the path-integrated concentration distribution. Principles of tomography have been employed for the reconstruction of concentration field at select horizontal planes above the growing crystal. Results have been presented in the form of rainbow schlieren images of the convective field, path-averaged solute concentration distribution around the growing for each view angle and local concentration distribution at select horizontal planes above the crystal top surface. Recorded color schlieren images have been compared with those of the conventional monochrome schlieren and interferometric techniques for the same experimental conditions. The extent of color re-distribution as seen from the recorded rainbow schlieren images correlate well with the bright intensity regions of monochrome schlieren images and the extent of fringe deformation in the interferometric images. The comparison has been performed for a small as well as a comparatively larger-sized crystal. For small sized-crystal, the observed color redistribution is seen to be weak and restricted to the crystal vicinity only whereas the color changes are more

  20. Variability of atmospheric pesticide concentrations between urban and rural areas during intensive pesticide application

    NASA Astrophysics Data System (ADS)

    Scheyer, Anne; Morville, Stéphane; Mirabel, Philippe; Millet, Maurice

    Intensive pesticide use leads to the contamination of water, soil and atmosphere. Atmospheric transport is responsible for pesticide dispersal over long distances. In this study, we evaluate the local dispersal of pesticides from agricultural to urban areas. For this purpose, three high-volume samplers, each equipped with a glass fiber filter and XAD-2 resin for the sampling of particulate and gas phase have been placed in a south-west transect (predominant wind direction) characteristic of rural and urban areas. The urban site (Strasbourg centre) is situated in the middle of two rural sites. Samples were taken simultaneously at three sites during pesticide treatments in autumn and spring 2002-2003. Sampling took place for 24 h at a flow rate of 10-15 m 3 h -1. The pesticides studied were those commonly used in the Alsace region for all crops (maize, cereal, vines …). Many of the pesticides analysed in atmospheric samples were not detected or observed very episodically at very low concentrations. For metolachlor, alachlor, trifluralin, atrazine and diflufenican, higher concentrations were observed, essentially during the application of these compounds. Moreover, some "spraying peaks" were observed for alachlor in the south rural site (near crops) at a level of 31 ng m -3 on 16-17 May 2003. These results show site and time dependence of atmospheric contamination by pesticides. A limited dispersal was also observed especially in the urban area during the application periods of pesticides.

  1. Application of Fourier transform infrared ellipsometry to assess the concentration of biological molecules.

    PubMed

    Garcia-Caurel, Enric; Drévillon, Bernard; De Martino, Antonello; Schwartz, Laurent

    2002-12-01

    Spectroscopic ellipsometry is a noninvasive optical characterization technique mainly used in the semiconductor field to characterize bare substrates and thin films. In particular, it allows the gathering of information concerning the physical structure of the sample, such as roughness and film thickness, as well as its optical response. In the mid-infrared (IR) range each molecule exhibits a characteristic absorption fingerprint, which makes this technique chemically selective. Phase-modulated IR ellipsometry does not require a baseline correction procedure or suppression of atmospheric CO2 and water-vapor absorption bands, thus greatly reducing the subjectivity in data analysis. We have found that ellipsometric measurements of thin films, such as the solid residuals left on a plane surface after evaporation of a liquid drop containing a given compound in solution, are particularly favorable for dosing purposes because the intensity of IR absorptions shows a linear behavior along a wide range of solution concentrations of the given compound. Our aim is to illustrate with a concrete example and to justify theoretically the linearity experimentally found between radiation absorption and molecule concentration. For the example, we prepared aqueous solutions of glycogen, a molecule of huge biological importance currently tested in biochemical analyses, at concentrations ranging from 1 mg/l to 1 g/l which correspond to those found in physiological conditions. The results of this example are promising for the application of ellipsometry for dosing purposes in biochemistry and biomedicine. PMID:12477127

  2. A method of measuring gold nanoparticle concentrations by x-ray fluorescence for biomedical applications

    SciTech Connect

    Wu Di; Li Yuhua; Wong, Molly D.; Liu Hong

    2013-05-15

    Purpose: This paper reports a technique that enables the quantitative determination of the concentration of gold nanoparticles (GNPs) through the accurate detection of their fluorescence radiation in the diagnostic x-ray spectrum. Methods: Experimentally, x-ray fluorescence spectra of 1.9 and 15 nm GNP solutions are measured using an x-ray spectrometer, individually and within chicken breast tissue samples. An optimal combination of excitation and emission filters is determined to segregate the fluorescence spectra at 66.99 and 68.80 keV from the background scattering. A roadmap method is developed that subtracts the scattered radiation (acquired before the insertion of GNP solutions) from the signal radiation acquired after the GNP solutions are inserted. Results: The methods effectively minimize the background scattering in the spectrum measurements, showing linear relationships between GNP solutions from 0.1% to 10% weight concentration and from 0.1% to 1.0% weight concentration inside a chicken breast tissue sample. Conclusions: The investigation demonstrated the potential of imaging gold nanoparticles quantitatively in vivo for in-tissue studies, but future studies will be needed to investigate the ability to apply this method to clinical applications.

  3. Split Nitrogen Application Improves Wheat Baking Quality by Influencing Protein Composition Rather Than Concentration.

    PubMed

    Xue, Cheng; Auf'm Erley, Gunda Schulte; Rossmann, Anne; Schuster, Ramona; Koehler, Peter; Mühling, Karl-Hermann

    2016-01-01

    The use of late nitrogen (N) fertilization (N application at late growth stages of wheat, e.g., booting, heading or anthesis) to improve baking quality of wheat has been questioned. Although it increases protein concentration, the beneficial effect on baking quality (bread loaf volume) needs to be clearly understood. Two pot experiments were conducted aiming to evaluate whether late N is effective under controlled conditions and if these effects result from increased N rate or N splitting. Late N fertilizers were applied either as additional N or split from the basal N at late boot stage or heading in the form of nitrate-N or urea. Results showed that late N fertilization improved loaf volume of wheat flour by increasing grain protein concentration and altering its composition. Increasing N rate mainly enhanced grain protein quantitatively. However, N splitting changed grain protein composition by enhancing the percentages of gliadins and glutenins as well as certain high molecular weight glutenin subunits (HMW-GS), which led to an improved baking quality of wheat flour. The late N effects were greater when applied as nitrate-N than urea. The proportions of glutenin and x-type HMW-GS were more important than the overall protein concentration in determining baking quality. N splitting is more effective in improving wheat quality than the increase in the N rate by late N, which offers the potential to cut down N fertilization rates in wheat production systems. PMID:27313585

  4. Split Nitrogen Application Improves Wheat Baking Quality by Influencing Protein Composition Rather Than Concentration

    PubMed Central

    Xue, Cheng; auf’m Erley, Gunda Schulte; Rossmann, Anne; Schuster, Ramona; Koehler, Peter; Mühling, Karl-Hermann

    2016-01-01

    The use of late nitrogen (N) fertilization (N application at late growth stages of wheat, e.g., booting, heading or anthesis) to improve baking quality of wheat has been questioned. Although it increases protein concentration, the beneficial effect on baking quality (bread loaf volume) needs to be clearly understood. Two pot experiments were conducted aiming to evaluate whether late N is effective under controlled conditions and if these effects result from increased N rate or N splitting. Late N fertilizers were applied either as additional N or split from the basal N at late boot stage or heading in the form of nitrate-N or urea. Results showed that late N fertilization improved loaf volume of wheat flour by increasing grain protein concentration and altering its composition. Increasing N rate mainly enhanced grain protein quantitatively. However, N splitting changed grain protein composition by enhancing the percentages of gliadins and glutenins as well as certain high molecular weight glutenin subunits (HMW-GS), which led to an improved baking quality of wheat flour. The late N effects were greater when applied as nitrate-N than urea. The proportions of glutenin and x-type HMW-GS were more important than the overall protein concentration in determining baking quality. N splitting is more effective in improving wheat quality than the increase in the N rate by late N, which offers the potential to cut down N fertilization rates in wheat production systems. PMID:27313585

  5. On the concentration of large deviations for fat tailed distributions, with application to financial data

    NASA Astrophysics Data System (ADS)

    Filiasi, Mario; Livan, Giacomo; Marsili, Matteo; Peressi, Maria; Vesselli, Erik; Zarinelli, Elia

    2014-09-01

    Large deviations for fat tailed distributions, i.e. those that decay slower than exponential, are not only relatively likely, but they also occur in a rather peculiar way where a finite fraction of the whole sample deviation is concentrated on a single variable. The regime of large deviations is separated from the regime of typical fluctuations by a phase transition where the symmetry between the points in the sample is spontaneously broken. For stochastic processes with a fat tailed microscopic noise, this implies that, while typical realizations are well described by a diffusion process with continuous sample paths, large deviation paths are typically discontinuous. For eigenvalues of random matrices with fat tailed distributed elements, a large deviation where the trace of the matrix is anomalously large concentrates on just a single eigenvalue, whereas in the thin tailed world the large deviation affects the whole distribution. These results find a natural application to finance. Since the price dynamics of financial stocks are characterized by fat tailed increments, large fluctuations in stock prices are expected to be realized by discrete jumps. Interestingly, we find that large excursions of prices are more likely realized by continuous drifts rather than by discontinuous jumps. Indeed, auto correlations suppress the concentration of large deviations. Financial covariance matrices also exhibit an anomalously large eigenvalue, the market mode, as compared to the prediction of random matrix theory. We show that this is explained by a large deviation with excess covariance rather than by one with excess volatility.

  6. Solar concentrator technology development for space based applications, volume 1. Final report

    SciTech Connect

    Pintz, A.; Castle, C.H.; Reimer, R.R.

    1992-12-01

    Thermoelectric conversion using a radio-isotope heat source has been used where outer planetary space craft are too far away for absorbing significant solar energy. Solar dynamic power (SDP) conversion is one technology that offers advantages for applications within the inner planet region. Since SDP conversion efficiency can be 2 to 3 times higher than photovoltaic, the collecting surfaces are much reduced in area and therefore lighter. This becomes an advantage in allocating more weight to launched payloads. A second advantage results for low earth orbit applications. The reduced area results in lower drag forces on the spacecraft and requires less reboost propellant to maintain orbit. A third advantage occurs because of the sun-to-shade cycling while in earth orbit. Photovoltaic systems require batteries to store energy for use when in the shade, and battery life for periods of 10 to 15 years is not presently achievable. For these reasons the Solar Dynamics and Thermal Systems Branch at NASA LeRC has funded work in developing SDP systems. The generic SDP system uses a large parabolic solar concentrator to focus solar energy onto a power conversion device. The concentrators are large areas and must therefore be efficient and have low specific weights. Yet these surfaces must be precise and capable of being stowed in a launch vehicle and then deployed and sometimes unfurled in space. There are significant technical challenges in engineering such structures, and considerable investigation has been made to date. This is the first of two volumes reporting on the research done by the Advanced Manufacturing Center at Cleveland State University to assist NASA LeRC in evaluating this technology. The objective of the grant was to restore the solar concentrator development technology of the 1960s while improving it with advances that have occurred since then.

  7. Solar concentrator technology development for space based applications, volume 2. Final report

    SciTech Connect

    Pintz, A.; Castle, C.H.; Reimer, R.R.

    1992-12-01

    Thermoelectric conversion using a radio-isotope heat source has been used where outer planetary space craft are too far away for absorbing significant solar energy. Solar dynamic power (SDP) conversion is one technology that offers advantages for applications within the inner planet region. Since SDP conversion efficiency can be 2 to 3 times higher than photovoltaic, the collecting surfaces are much reduced in area and therefore lighter. This becomes an advantage in allocating more weight to launched payloads. A second advantage results for low earth orbit applications. The reduced area results in lower drag forces on the spacecraft and requires less reboost propellant to maintain orbit. A third advantage occurs because of the sun-to-shade cycling while in earth orbit. Photovoltaic systems require batteries to store energy for use when in the shade, and battery life for periods of 10 to 15 years is not presently achievable. For these reasons the Solar Dynamics and Thermal Systems Branch at NASA LeRC has funded work in developing SDP systems. The generic SDP system uses a large parabolic solar concentrator to focus solar energy onto a power conversion device. The concentrators are large areas and must therefore be efficient and have low specific weights. Yet these surfaces must be precise and capable of being stowed in a launch vehicle and then deployed and sometimes unfurled in space. There are significant technical challenges in engineering such structures, and considerable investigation has been made to date. This is the second of two volumes reporting on the research done by the Advanced Manufacturing Center at Cleveland State University to assist NASA LeRC in evaluating this technology. This volume includes the appendices of selected data sets, drawings, and procedures. The objective of the grant was to restore the solar concentrator development technology of the 1960s while improving it with advances that have occurred since then.

  8. Modelling of catchment nitrogen concentrations response to observed varying fertilizer application intensities

    NASA Astrophysics Data System (ADS)

    Jomaa, Seifeddine; Jiang, Sanyuan; Yang, Xiaoqiang; Rode, Michael

    2016-04-01

    Eutrophication is a serious environmental problem. Despite numerous experimental and modelling efforts, understanding of the effect of land use and agriculture practices on in-stream nitrogen fluxes is still not fully achieved. This study combined intensive field monitoring and numerical modelling using 30 years of surface water quality data of a drinking water reservoir catchment in central Germany. The Weida catchment (99.5 km2) is part of the Elbe river basin and has a share of 67% of agricultural land use with significant changes in agricultural practices within the investigation period. The geology of the Weida catchment is characterized by clay schists and eruptive rocks, where rocks have low permeability. The semi-distributed hydrological water quality HYPE (Hydrological Predictions for the Environment) model was used to reproduce the measured data. First, the model was calibrated for discharge and nitrate-N concentrations (NO3-N) during the period 1997-2000. Then, the HYPE model was validated successfully for three different periods 1983-1987, 1989-1996 and 2000-2003, which are charaterized by different fertilizer application rates (with lowest discharge prediction performance of NSE = 0.78 and PBIAS = 3.74%, considering calibration and validation periods). Results showed that the measured as well as simulated in-stream nitrate-N concentration respond quickly to fertilizer application changes (increase/decrease). This rapid response can be explained with short residence times of interflow and baseflow runoff components due to the hardrock geological properties of the catchment. Results revealed that the surface runoff and interflow are the most dominant runoff components. HYPE model could reproduce reasonably well the NO3-N daily loads for varying fertilizer application, when detailed input data in terms of crop management (field-specific survey) are considered.

  9. A compact photometer based on metal-waveguide-capillary: application to detecting glucose of nanomolar concentration

    PubMed Central

    Bai, Min; Huang, Hui; Hao, Jian; Zhang, Ji; Wu, Haibo; Qu, Bo

    2015-01-01

    Trace analysis of liquid samples has wide applications in life science and environmental monitor. In this paper, a compact and low-cost photometer based on metal-waveguide-capillary (MWC) was developed for ultra-sensitive absorbance detection. The optical-path can be greatly enhanced and much longer than the physical length of MWC, because the light scattered by the rippled and smooth metal sidewall can be confined inside the capillary regardless of the incident-angle. For the photometer with a 7 cm long MWC, the detection limit is improved ~3000 fold compared with that of commercial spectrophotometer with 1 cm-cuvette, owing to the novel nonlinear optical-path enhancement as well as fast sample switching, and detecting glucose of a concentration as low as 5.12 nM was realized with conventional chromogenic reagent. PMID:26020222

  10. A compact photometer based on metal-waveguide-capillary: application to detecting glucose of nanomolar concentration.

    PubMed

    Bai, Min; Huang, Hui; Hao, Jian; Zhang, Ji; Wu, Haibo; Qu, Bo

    2015-01-01

    Trace analysis of liquid samples has wide applications in life science and environmental monitor. In this paper, a compact and low-cost photometer based on metal-waveguide-capillary (MWC) was developed for ultra-sensitive absorbance detection. The optical-path can be greatly enhanced and much longer than the physical length of MWC, because the light scattered by the rippled and smooth metal sidewall can be confined inside the capillary regardless of the incident-angle. For the photometer with a 7 cm long MWC, the detection limit is improved ~3000 fold compared with that of commercial spectrophotometer with 1 cm-cuvette, owing to the novel nonlinear optical-path enhancement as well as fast sample switching, and detecting glucose of a concentration as low as 5.12 nM was realized with conventional chromogenic reagent. PMID:26020222

  11. AMS method for depth profiling of trace elements concentration in materials - Construction and applications

    NASA Astrophysics Data System (ADS)

    Stan-Sion, C.; Enachescu, M.

    2015-10-01

    The need to investigate the behavior of solid state materials on the impact/retention/repulsion/contamination/impregnation with special trace elements or radioactive elements has driven us to develop a modified Accelerator Mass Spectrometry (AMS) analyzing method that is able to perform the measurement of the concentration depth profile of an element in a host material. This upgraded method that we call AMS-depth profiling method (AMS-DP) measures continuously the concentration of a trace element in a given sample material as a function of the depth from the surface (e.g., tritium in carbon, deuterium in tungsten, etc.). However, in order to perform depth profiling, common AMS facilities have to undergo several changes: a new replaceable sample target-holder has to be constructed to accept small plates of solid material as samples; their position has to be adjusted in the focus point of the sputter beam; crater rim effects of the produced hole in the sample have to be avoided or removed from the registered events in the detector; suitable reference samples have to be prepared and used for calibration. All procedures are presented in the paper together with several applications.

  12. High-efficiency GaAs solar concentrator cells for space and terrestrial applications

    NASA Technical Reports Server (NTRS)

    Hamaker, H. C.; Werthen, J. G.; Ford, C. W.; Virshup, G. F.; Kaminar, N. R.

    1986-01-01

    High-efficiency Al(x)Ga(1-x)As/GaAs heteroface solar concentrator cells have been developed for both space and terrestrial applications. The cells, which were grown using metalorganic chemical vapor deposition, have been fabricated in both the p-n and n-p configurations. Magnesium and zinc are used as p-type dopants, and Se is used as the n-type dopant. The space cells, which are designed for use in a Cassegrainian concentrator operating at 100 suns, AMO, have a circular illuminated area 4 mm in diameter on a 5 mm x 5 mm cell. These cells have exhibited flash-tested efficiencies as high as 23.6 percent at 28 C and 21.6 percent at 80 C. The terrestrial cells have a circular illuminated area 0.2 inches in diameter and are intended for use in a module which operates at 940 suns, AM1.5. These cells have shown a peak efficiency of 26 percent at 753 suns and over 25 percent at greater than 1000 suns.

  13. Studies of Antarctic Sea Ice Concentrations from Satellite Data and Their Applications

    NASA Technical Reports Server (NTRS)

    Comiso, Josefino C.; Steffen, Konrad; Zukor, Dorothy J. (Technical Monitor)

    2001-01-01

    Large changes in the sea ice cover have been observed recently. Because of the relevance of such changes to climate change studies it is important that key ice concentration data sets used for evaluating such changes are interpreted properly. High and medium resolution visible and infrared satellite data are used in conjunction with passive microwave data to study the true characteristics of the Antarctic sea ice cover, assess errors in currently available ice concentration products, and evaluate the applications and limitations of the latter in polar process studies. Cloud-free high resolution data provide valuable information about the natural distribution, stage of formation, and composition of the ice cover that enables interpretation of the large spatial and temporal variability of the microwave emissivity of Antarctic sea ice. Comparative analyses of co-registered visible, infrared and microwave data were used to evaluate ice concentrations derived from standard ice algorithms (i.e., Bootstrap and Team) and investigate the 10 to 35% difference in derived values from large areas within the ice pack, especially in the Weddell Sea, Amundsen Sea, and Ross Sea regions. Landsat and OLS data show a predominance of thick consolidated ice in these areas and show good agreement with the Bootstrap Algorithm. While direct measurements were not possible, the lower values from the Team Algorithm results are likely due to layering within the ice and snow and/or surface flooding, which are known to affect the polarization ratio. In predominantly new ice regions, the derived ice concentration from passive microwave data is usually lower than the true percentage because the emissivity of new ice changes with age and thickness and is lower than that of thick ice. However, the product provides a more realistic characterization of the sea ice cover, and are more useful in polar process studies since it allows for the identification of areas of significant divergence and polynya

  14. High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrator Application

    SciTech Connect

    Hubbard, Seth

    2012-09-12

    The High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrators project seeks to provide new photovoltaic cells for Concentrator Photovoltaics (CPV) Systems with higher cell efficiency, more favorable temperature coefficients and less sensitivity to changes in spectral distribution. The main objective of this project is to provide high efficiency III-V solar cells that will reduce the overall cost per Watt for power generation using CPV systems.This work is focused both on a potential near term application, namely the use of indium arsenide (InAs) QDs to spectrally "tune" the middle (GaAs) cell of a SOA triple junction device to a more favorable effective bandgap, as well as the long term goal of demonstrating intermediate band solar cell effects. The QDs are confined within a high electric field i-region of a standard GaAs solar cell. The extended absorption spectrum (and thus enhanced short circuit current) of the QD solar cell results from the increase in the sub GaAs bandgap spectral response that is achievable as quantum dot layers are introduced into the i-region. We have grown InAs quantum dots by OMVPE technique and optimized the QD growth conditions. Arrays of up to 40 layers of strain balanced quantum dots have been experimentally demonstrated with good material quality, low residual stain and high PL intensity. Quantum dot enhanced solar cells were grown and tested under simulated one sun AM1.5 conditions. Concentrator solar cells have been grown and fabricated with 5-40 layers of QDs. Testing of these devices show the QD cells have improved efficiency compared to baseline devices without QDs. Device modeling and measurement of thermal properties were performed using Crosslight APSYS. Improvements in a triple junction solar cell with the insertion of QDs into the middle current limiting junction was shown to be as high as 29% under one sun illumination for a 10 layer stack QD enhanced triple junction solar cell. QD devices have strong

  15. Predicting and measuring environmental concentration of pesticides in air after soil application.

    PubMed

    Ferrari, Federico; Trevisan, Marco; Capri, Ettore

    2003-01-01

    Pesticides can volatilize into the atmosphere, which affects the air quality. The ability to predict pesticide volatilization is an essential tool for human risk and environmental assessment. Even though there are several mathematical models to assess and predict the fate of pesticides in different compartments of the environment, there is no reliable model to predict volatilization. The objectives of this study were to evaluate pesticide volatilization under agricultural conditions using malathion [ O,O-dimethyl-S-(1,2-dicarbethoxyethyl)-dithiophosphate], ethoprophos (O-ethyl S,S-dipropylphosphorodithioate), and procymidone [N-(3,5-dichlorophenyl)-1,2-dimethylcyclopropane-1,2-dicarboximide] as test compounds and to evaluate the ability of the Pesticide Leaching Model (PELMO) to calculate the predicted environmental concentrations of pesticides in air under field conditions. The volatilization rate of procymidone, malathion, and ethoprophos was determined in a field study during two different periods (December 1998 and September 1999) using the Theoretical Profile Shape (TPS) method. The experiments were performed on bare silty soil in the Bologna province, Italy. Residues in the air were continuously monitored for 2 to 3 wk after the pesticide applications. The amount of pesticide volatilized was 16, 5, and 11% in December 1998 and 41, 23, and 19% in September 1999 for procymidone, malathion, and ethoprophos, respectively. In both these experiments, the PELMO simulations of the concentration of ethoprophos and procymidone were in good agreement with the measured data (factor +/- 1.1 on average). The volatilization of malathion was underestimated by a factor of 30 on average. These results suggest that volatilization described by PELMO may be reliable for volatile substances, but PELMO may underpredict volatilization for less-volatile substances. PMID:14535302

  16. Intramammary administration of platelet concentrate as an unconventional therapy in bovine mastitis: first clinical application.

    PubMed

    Lange-Consiglio, A; Spelta, C; Garlappi, R; Luini, M; Cremonesi, F

    2014-10-01

    Bovine udder infections induce a variety of changes in gene expression of different growth factors that may suggest their possible role in glandular tissue protection or repair processes. Growth factors and also chemokines and cytokines may act synergistically to increase the infiltration of neutrophils and macrophages to promote angiogenesis, fibroplasia, matrix deposition, and, ultimately, re-epithelialization. Considering the vast applications, typically in human medicine, of platelet concentrate (PC) and its ease of preparation, the aim of our study was to evaluate an alternative therapy to stimulate the regeneration of glandular tissue, administering a concentration in excess of the growth factors contained in the PC. In each one of the 3 farms examined in the trial, PC was prepared from donor cows in good health, free from infections, and with no records of medications administered during the previous 2 mo. The platelet produced in one farm was used only for treating the cows of the same farm in a heterologous way. A total of 229 mastitic quarters were divided in 3 groups: antibiotic group (treated with intramammary antibiotic), antibiotic and PC group (treated intramammarily with antibiotics in association with PC), and PC group (treated with intramammary PC alone). The diagnosis of mastitis was based on somatic cell count and bacteriological evaluation of the milk from the affected quarter. Platelet concentrate, alone or in association with antibiotic, was used for 3 consecutive days as an unconventional therapy in bovine acute and chronic mastitis. Our data show that the associated action of antibiotic and PC performed significantly better than the antibiotic alone, either for the recovery of the affected mammary quarters or for somatic cell count reduction. In the same way, the association antibiotic plus PC showed significantly fewer relapses compared with the antibiotic alone, either for acute or chronic mastitis. The treatment with only PC did not show

  17. Effect of calcium silicate slag application on radium-226 concentrations in plant tissues

    SciTech Connect

    Mortvedt, J.J.

    1986-01-01

    A greenhouse pot experiment was conducted to determine if plants absorb Ra from slag applied to soil. Slag at rates equivalent to 0 and 22 mt/ha was mixed with Mountview silt loam (Typic Paleudults) limed to pH 5.8 and 7.2. Three clippings each of fescue (Festuca arundiancea Schreb.), and Swiss chard (Beta vulgaris L.), and one harvest of wheat (Triticum aestivum L.) for grain and straw were grown on separate series of treated soil, and plant samples were analyzed for radioactivity due to /sup 226/Ra uptake. Samples of sugarcane (Saccharum officinarum L.) forage and extracted juice from field experiments in Florida testing this slage as a Si source also were analyzed for radioactivity. Dry forage yields of fescue and wheat were not affected by slag applications, but those of Swiss chard were somewhat higher on slag-treated soil at pH 5.8. Wheat grain and straw yields were higher on soil at pH 7.2 than at pH 5.8 regardless of slag treatment. Uptake of /sup 226/Ra by fescue forage and wheat grain and straw was not affected by slag application. Concentrations of /sup 226/Ra were similar in forage and extracted juice from untreated sugarcane or that treated with slag at rates up to 5.6 mt/ha. These results suggest that plant uptake of radionuclides is negligible from calcium silicate slag applied at the recommended rates for liming acid soils or as a source of Si for sugarcane.

  18. Effect of road salt application on seasonal chloride concentrations and toxicity in south-central Indiana streams.

    PubMed

    Gardner, Kristin M; Royer, Todd V

    2010-01-01

    Contemporary information on road salt runoff is needed for management of water resources in regions experiencing urbanization and increased road density. We investigated seasonal Cl(-) concentrations among five streams in south-central Indiana that drained watersheds varying in degree of urbanization and ranging in size from 9.3 to 27 km(2). We also conducted acute toxicity tests with Daphnia pulex to assess the potential effects of the observed Cl(-) concentrations on aquatic life. Periods of elevated Cl(-) concentrations were observed during the winters of 2007-08 and 2008-09 at all sites except the reference site. The highest Cl(-) concentration observed during the study was 2100 mg L(-1) and occurred at the most urbanized site. The Cl(-) concentration at the reference site never exceeded 22 mg L(-1). The application of road salt caused large increases in stream Cl(-) concentrations, but the elevated Cl(-) levels did not appear to be a significant threat to aquatic life based on our toxicity testing. Only the most urbanized site showed evidence of salt retention within the watershed, whereas the other sites exported the road salt relatively quickly after its application, suggesting storm drains and impervious surfaces minimized interaction between soils and salt-laden runoff. During winter at these sites, the response in stream Cl(-) concentrations appeared to be controlled by the timing and intensity of road salt application, the magnitude of precipitation, and the occurrence of air temperatures that caused snowmelt and generated runoff. PMID:20400599

  19. Oral Mucosal Ulceration Caused by the Topical Application of a Concentrated Propolis Extract

    PubMed Central

    Wimardhani, Yuniardini Septorini

    2014-01-01

    Propolis is a resinous mixture that is collected by honey bees from tree buds, sap flow, and other botanical sources. Propolis has been extensively used in medicine, dentistry, and cosmetics; however, unwanted effects have been reported. This paper reports a case of oral mucosal burn in a 50-year-old patient, who used an overnight application of concentrated propolis to overcome a throbbing pain in the right upper posterior mucosa. The patient was otherwise healthy and was not receiving any medication. She presented with painful shallow multiple irregular ulcers measuring 0.3–1 cm in diameter that were located on the right buccal mucosa and hard palate mucosa, in addition to the gingival mucosa surrounding tooth 17. Propolis-induced oral mucosal burn was diagnosed. The ulcer cleared after the prescription of tetracycline mouthwash, accompanied with Doloneurobion. The patient was further treated with carbamazepine to address the persistent throbbing pain in the affected area, which was suspected to be trigeminal neuralgia. This report provides another alert to clinicians about the potential adverse effects of propolis use for the treatment of oral diseases, despite its natural origin. PMID:25276439

  20. Effect of concentrated epoxidised natural rubber and silica masterbatch for tyre application

    NASA Astrophysics Data System (ADS)

    Azira, A. A.; Verasamy, D.; Kamal, M. M.

    2016-07-01

    The availability of concentrated epoxidised natural rubber (ENR-LC) has provided a better opportunity for using epoxidised natural rubber (ENR) with silica to reinforce natural rubber for tyre application. ENR-LC mixed directly with silica to rubber by high speed stirrer without using any coupling agent. Some rubber compounds were prepared by mixing a large amount of precipitated amorphous white silica with natural rubber. The silica was prepared in aqueous dispersion and the filler was perfectly dispersed in the ENR-LC. The performance of the composites was evaluated in this work for the viability of ENR-LC/Si in tyre compounding. Compounding was carried out on a two roll mill, where the additives and curing agents was later mixed. Characterization of these composites was performed by Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM) for dispersion as well as mechanical testing. C-ENR/Si showed efficient as primary reinforcing filler in ENR with regard to modulus and tensile strength, resulting on an increase in the stiffness of the rubbers compared to ENR latex. Overall improvement in the mechanical properties for the ENR-LC over the control crosslinked rubber sample was probably due to synergisms of silica reinforcement and crosslinking of the polymeric matrix phase.

  1. Improved high temperature solar absorbers for use in Concentrating Solar Power central receiver applications.

    SciTech Connect

    Stechel, Ellen Beth; Ambrosini, Andrea; Hall, Aaron Christopher; Lambert, Timothy L.; Staiger, Chad Lynn; Bencomo, Marlene

    2010-09-01

    Concentrating solar power (CSP) systems use solar absorbers to convert the heat from sunlight to electric power. Increased operating temperatures are necessary to lower the cost of solar-generated electricity by improving efficiencies and reducing thermal energy storage costs. Durable new materials are needed to cope with operating temperatures >600 C. The current coating technology (Pyromark High Temperature paint) has a solar absorptance in excess of 0.95 but a thermal emittance greater than 0.8, which results in large thermal losses at high temperatures. In addition, because solar receivers operate in air, these coatings have long term stability issues that add to the operating costs of CSP facilities. Ideal absorbers must have high solar absorptance (>0.95) and low thermal emittance (<0.05) in the IR region, be stable in air, and be low-cost and readily manufacturable. We propose to utilize solution-based synthesis techniques to prepare intrinsic absorbers for use in central receiver applications.

  2. Measuring and predicting environmental concentrations of pesticides in air after application to paddy water systems.

    PubMed

    Ferrari, Federico; Karpouzas, Dimitrios G; Trevisan, Marco; Capri, Ettore

    2005-05-01

    In this study, the volatilization of five pesticides applied to an artificial flooded paddy field was assessed using the theoretical profile shape (TPS) and the integrate horizontal flux (IHF) techniques. The dataset derived was utilized to improve the volatilization routine of the rice water quality (RICEWQ) model. The masses of pesticides ethoprophos, procymidone, metalaxyl, chlorpyrifos, and chlorpyrifos methyl volatilized from paddy water and their concentrations in paddy water were determined for a period of 6 d after application. The highest and lowest volatilization losses were observed for chlorpyrifos and metalaxyl, respectively, accounting for 3.3% and 0.03% of their initially applied amount. A rapid pesticide dissipation was evident in paddy water during the study period. The RICEWQ model was used to simulate the fate of pesticides in the artificial paddy system. The Kvolat, an empiric coefficient used by the model as an input parameter, was calculated for all pesticides through model calibration. RICEWQ simulated well the fate of pesticides in paddy water. A significant regression correlation between Henry's law constant (Hk) and Kvolat of the studied compounds was established which could facilitate the parametrization of the model for describing pesticide volatilization. PMID:15926540

  3. Whey protein phospholipid concentrate and delactosed permeate: Applications in caramel, ice cream, and cake.

    PubMed

    Levin, M A; Burrington, K J; Hartel, R W

    2016-09-01

    Whey protein phospholipid concentrate (WPPC) and delactosed permeate (DLP) are 2 coproducts of cheese whey processing that are currently underutilized. Past research has shown that WPPC and DLP can be used together as a functional dairy ingredient in foods such as ice cream, soup, and caramel. However, the scope of the research has been limited to a single WPPC supplier. The variability of the composition and functionality of WPPC was previously studied. The objective of this research was to expand on the previous study and examine the potential applications of WPPC and DLP blends in foods. In ice cream, WPPC was added as a natural emulsifier to replace synthetic emulsifiers. The WPPC decreased the amount of partially coalesced fat and increased the drip-through rate. In caramel, DLP and WPPC replaced sweetened condensed skim milk and lecithin. Cold flow increased significantly, and hardness and stickiness decreased. In cake, DLP and WPPC were added as a total replacement of eggs, with no change in yield, color, or texture. Overall, WPPC and DLP can be utilized as functional dairy ingredients at a lower cost in ice cream and cake but not in chewy caramel. PMID:27344387

  4. Optimization of a dual concentric conductor antenna for superficial hyperthermia applications.

    PubMed

    Maccarini, Paolo F; Rolfsnes, Hans-Olav; Neuman, Daniel; Stauffer, Paul

    2004-01-01

    Dual concentric conductor antennas (DCCs) have been proposed as effective radiators for microwave hyperthermia applications, due to simplicity of construction from flexible printed circuit board (PCB) material. With proper design, the power deposition (SAR) pattern is uniform across the DCC. The effect of a single antenna can be combined in conformal nonphased arrays to form a region of nearly flat temperature distribution over a large area down to 1-1.5 cm depth. In the past, DCC antenna performance was analyzed using in-house FDTD software. Recently available electromagnetic simulation software provides reduced simulation time, increased accuracy and a user friendly interface with the ability to sweep design parameters to achieve critical optimization goals. More detail on antenna loading conditions provides enhanced design accuracy by accounting for second order effects neglected in previous modeling. In particular, recent design efforts have focused on improving antenna efficiency and reducing losses and reflections in the feedline network. A second challenge involves measurement of antenna properties in conditions more similar to the treatment environment, since temperature and loading condition affect antenna radiation and thus design requirements. We present the challenges of both antenna design and characterization, along with preliminary results of recent design improvements. PMID:17270785

  5. REGIONAL CHARACTERISTICS OF NUTRIENT CONCENTRATIONS IN STREAMS AND THEIR APPLICATION TO NUTRIENT CRITERIA DEVELOPMENT

    EPA Science Inventory

    In order to establish meaningful nutrient criteria, consideration must be given to the spatial variations in geographic phenomena that cause or reflect differences in nutrient concentrations in streams. Regional differences in stream nutrient concentrations were illustrated usin...

  6. Concentration polarisation in heterogeneous electrochemical reactions: a consistent kinetic evaluation and its application to molten carbonate fuel cells

    NASA Astrophysics Data System (ADS)

    Bosio, B.; Arato, E.; Costa, P.

    Aim of this work is to focus attention on how the concentration polarization, in all electrochemistry applications, is often formulated on the basis of only thermodynamic statements and how it should be written in a kinetic more consistent expression. Moreover, the application of this study to the analysis of molten carbonate fuel cell (MCFC) behaviour has been discussed with reference to diffusion limited operating conditions.

  7. Development and Application of Watershed Regressions for Pesticides (WARP) for Estimating Atrazine Concentration Distributions in Streams

    USGS Publications Warehouse

    Larson, Steven J.; Crawford, Charles G.; Gilliom, Robert J.

    2004-01-01

    Regression models were developed for predicting atrazine concentration distributions in rivers and streams, using the Watershed Regressions for Pesticides (WARP) methodology. Separate regression equations were derived for each of nine percentiles of the annual distribution of atrazine concentrations and for the annual time-weighted mean atrazine concentration. In addition, seasonal models were developed for two specific periods of the year--the high season, when the highest atrazine concentrations are expected in streams, and the low season, when concentrations are expected to be low or undetectable. Various nationally available watershed parameters were used as explanatory variables, including atrazine use intensity, soil characteristics, hydrologic parameters, climate and weather variables, land use, and agricultural management practices. Concentration data from 112 river and stream stations sampled as part of the U.S. Geological Survey's National Water-Quality Assessment and National Stream Quality Accounting Network Programs were used for computing the concentration percentiles and mean concentrations used as the response variables in regression models. Tobit regression methods, using maximum likelihood estimation, were used for developing the models because some of the concentration values used for the response variables were censored (reported as less than a detection threshold). Data from 26 stations not used for model development were used for model validation. The annual models accounted for 62 to 77 percent of the variability in concentrations among the 112 model development stations. Atrazine use intensity (the amount of atrazine used in the watershed divided by watershed area) was the most important explanatory variable in all models, but additional watershed parameters significantly increased the amount of variability explained by the models. Predicted concentrations from all 10 models were within a factor of 10 of the observed concentrations at most

  8. Development of a dome Fresnel lens/gallium arsenide photovoltaic concentrator for space applications

    NASA Technical Reports Server (NTRS)

    O'Neill, Mark J.; Piszczor, Michael F.

    1987-01-01

    A novel photovoltaic concentrator system is currently being developed. Phase I of the program, completed in late 1986, produced a conceptual design for the concentrator system, including an array weight and performance estimates based on optical, electrical, and thermal analyses. Phase II of the program, just underway, concerns the fabrication and testing of prototype concentrator panels of the design. The concentrator system uses dome Fresnel lenses for optical concentration; gallium arsenide concentrator cells for power generation; prismatic cell covers to eliminate gridline obscuration losses; a backplane radiator for heat rejection; and a honeycomb structure for the deployable panel assembly. The conceptual design of the system, its anticipated performance, and its estimated weight are reported.

  9. Trace element concentrations in leachates and mustard plant tissue (Sinapis alba L.) after biochar application to temperate soils.

    PubMed

    Kloss, Stefanie; Zehetner, Franz; Oburger, Eva; Buecker, Jannis; Kitzler, Barbara; Wenzel, Walter W; Wimmer, Bernhard; Soja, Gerhard

    2014-05-15

    Biochar application to agricultural soils has been increasingly promoted worldwide. However, this may be accompanied by unexpected side effects in terms of trace element (TE) behavior. We used a greenhouse pot experiment to study the influence of woodchip-derived biochar (wcBC) on leaching and plant concentration of various TEs (Al, Cd, Cu, Pb, Mn, As, B, Mo, Se). Three different agricultural soils from Austria (Planosol, Cambisol, Chernozem) were treated with wcBC at application rates of 1 and 3% (w/w) and subsequently planted with mustard (Sinapis alba L.). Soil samples were taken 0 and 7 months after the start of the pot experiment, and leachate water was collected twice (days 0 and 54). The extractability (with NH4NO3) of cationic TEs was decreased in the (acidic) Planosol and Cambisol after wcBC application, whereas in the (neutral) Chernozem it hardly changed. In contrast, anionic TEs were mobilized in all three soils, which resulted in higher anion concentrations in the leachates. The application of wcBC had no effect on Al and Pb in the mustard plants, but increased their B and Mo concentrations and decreased their Cd, Cu and Mn concentrations. A two-way analysis of variance showed significant interactions between wcBC application rate and soil type for most TEs, which indicates that different soil types may react differently upon wcBC application. Correlation and partial correlation analyses revealed that TE behavior was primarily related to soil pH, whereas the involvement of other factors such as electrical conductivity (EC), organic carbon (OC) content and dissolved organic carbon (DOC) was found to be more soil and TE-specific. The application of wcBC may be a useful strategy for the remediation of soils with elevated levels of cationic TEs, but could lead to deficiencies of cationic micronutrients and enhance short-term translocation of anionic TEs towards the groundwater at high leaching rates. PMID:24631613

  10. Effects of dairy slurry application and bale moisture concentration on voluntary intake and digestibility of alfalfa silage by sheep

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dairy slurry is used commonly as a fertilizer in agriculture. However, residual effects of slurry application on intake and digestibility of alfalfa silage from subsequent harvests are not well known. The objective of this study was to determine if moisture concentration of alfalfa silage and timing...

  11. BUBBLE STRIPPING TO DETERMINE HYDROGEN CONCENTRATIONS IN GROUND WATER: A PRACTICAL APPLICATION OF HENRY'S LAW

    EPA Science Inventory

    The Bubble Stripping Method is a chemical testing method that operates on the principle of Henry's Law. It is useful for determining concentrations of hydrogen in well water, and it is capable of detecting concentrations on the order of nanomoles per liter. The method provides ...

  12. Commercial Application of a Photovoltaic Concentrator system. Phase I. Final report, 1 June 1978-28 February 1979

    SciTech Connect

    Anderson, D.J.; Anderson, E.R.; Bardwell, K.M.

    1980-04-01

    This report documents the design and analysis of the BDM CAPVC (Commercial Application of a Photovoltaic Concentrator) system. The preliminary design, prototype test and evaluation, system analysis, and final design of a large-scale concentrating photovoltaic system are described. The application is on an attractive new office building which represents a large potential market. The photovoltaic concentrating array is a roof-mounted, single-axis linear parabolic trough, using single crystalline silicon photovoltaic cells. A total of 6720 square feet of aperture is focussed on 13,944 PV cells. The photovoltaic system operates in parallel with the local utility in an augmentary loadsharing operating mode. The array is actively cooled and the thermal energy utilized for building heat during winter months. (WHK)

  13. Formation of titanate nanostructures under different NaOH concentration and their application in wastewater treatment

    NASA Astrophysics Data System (ADS)

    Huang, Jiquan; Cao, Yongge; Deng, Zhonghua; Tong, Hao

    2011-03-01

    The effects of the concentration of NaOH on the formation and transformation of various titanate nanostructures were studied. With increasing NaOH concentration, three different formation mechanisms were proposed. Nanotubes can only be obtained under moderate NaOH conditions, and should transform into nanowires with prolonged hydrothermal treatment, and their formation rate is accelerated by increasing NaOH concentration. Low concentration of NaOH results in the direct formation of nanowires, while extra high concentration of NaOH leads to the formation of amorphous nanoparticles. Adsorption and photocatalysis studies show that titanate nanowires and nanotubes might be potential adsorbents for the removal of both heavy metal ions and dyes and photocatalysts for the removal of dyes from wastewater.

  14. Control oriented concentrating solar power (CSP) plant model and its applications

    NASA Astrophysics Data System (ADS)

    Luo, Qi

    Solar receivers in concentrating solar thermal power plants (CSP) undergo over 10,000 start-ups and shutdowns, and over 25,000 rapid rate of change in temperature on receivers due to cloud transients resulting in performance degradation and material fatigue in their expected lifetime of over 30 years. The research proposes to develop a three-level controller that uses multi-input-multi-output (MIMO) control technology to minimize the effect of these disturbances, improve plant performance, and extend plant life. The controller can be readily installed on any vendor supplied state-of-the-art control hardware. We propose a three-level controller architecture using multi-input-multi-output (MIMO) control for CSP plants that can be implemented on existing plants to improve performance, reliability, and extend the life of the plant. This architecture optimizes the performance on multiple time scalesreactive level (regulation to temperature set points), tactical level (adaptation of temperature set points), and strategic level (trading off fatigue life due to thermal cycling and current production). This controller unique to CSP plants operating at temperatures greater than 550 °C, will make CSPs competitive with conventional power plants and contribute significantly towards the Sunshot goal of 0.06/kWh(e), while responding with agility to both market dynamics and changes in solar irradiance such as due to passing clouds. Moreover, our development of control software with performance guarantees will avoid early stage failures and permit smooth grid integration of the CSP power plants. The proposed controller can be implemented with existing control hardware infrastructure with little or no additional equipment. In the thesis, we demonstrate a dynamics model of CSP, of which different components are modelled with different time scales. We also show a real time control strategy of CSP control oriented model in steady state. Furthermore, we shown different controllers

  15. Control of Surface Mounted Permanent Magnet Motors with Special Application to Fractional-Slot Concentrated Windings

    SciTech Connect

    Lawler, J.S.

    2005-12-21

    It is well known that the ability of the permanent magnet synchronous machine (PMSM) to operate over a wide constant power speed range (CPSR) is dependent upon the machine inductance [1,2,3,4,5]. Early approaches for extending CPSR operation included adding supplementary inductance in series with the motor [1] and the use of anti-parallel thyristor pairs in series with the motor-phase windings [5]. The increased inductance method is compatible with a voltage-source inverter (VSI) controlled by pulse-width modulation (PWM) which is called the conventional phase advance (CPA) method. The thyristor method has been called the dual mode inverter control (DMIC). Neither of these techniques has met with wide acceptance since they both add cost to the drive system and have not been shown to have an attractive cost/benefit ratio. Recently a method has been developed to use fractional-slot concentrated windings to significantly increase the machine inductance [6]. This latest approach has the potential to make the PMSM compatible with CPA without supplemental external inductance. If the performance of such drive is acceptable, then the method may make the PMSM an attractive option for traction applications requiring a wide CPSR. A 30 pole, 6 kW, 6000 maximum revolutions per minute (rpm) prototype of the fractional-slot PMSM design has been developed [7]. This machine has significantly more inductance than is typical of regular PMSMs. The prototype is to be delivered in late 2005 to the Oak Ridge National Laboratory (ORNL) for testing and development of a suitable controller. In advance of the test/control development effort, ORNL has used the PMSM models developed over a number of previous studies to study the steady-state performance of high-inductance PMSM machines with a view towards control issues. The detailed steady-state model developed includes all motor and inverter-loss mechanisms and will be useful in assessing the performance of the dynamic controller to be

  16. Serotonin Concentrations in the Lumbosacral Spinal Cord of the Adult Rat Following Microinjection or Dorsal Surface Application

    PubMed Central

    Brumley, Michele R.; Hentall, Ian D.; Pinzon, Alberto; Kadam, Brijesh H.; Blythe, Anthony; Sanchez, Francisco J.; Taberner, Annette M.; Noga, Brian R.

    2009-01-01

    Application of neuroactive substances, including monoamines, is common in studies examining the spinal mechanisms of sensation and behavior. However, affected regions and time courses of transmitter activity are uncertain. We measured the spatial and temporal distribution of serotonin [5-hydroxytryptamine (5-HT)] in the lumbosacral spinal cord of halothane-anesthetized adult rats, following its intraspinal microinjection or surface application. Carbon fiber microelectrodes (CFMEs) were positioned at various locations in the spinal cord and oxidation currents corresponding to extracellular 5-HT were measured by fast cyclic voltammetry. Intraspinal microinjection of 5-HT (100μM, 1–3 μl) produced responses that were most pronounced at CFMEs positioned ≤800 μm from the drug micropipette: 5-HT concentration was significantly higher (1.43 vs. <0.28% of initial concentration) and response latency was shorter (67.1 vs. 598.2 s) compared with more distantly positioned CFMEs. Treatment with the selective 5-HT reuptake inhibitor clomipramine only slightly affected the spread of microinjected 5-HT. Surface application over several segments led to a transient rise in concentration that was usually apparent within 30 s and was dramatically attenuated with increasing depth: 0.25% of initial concentration (1 mM) within 400 μm of the dorsal surface and <0.001% between 1,170 and 2,000 μm. This initial response to superfusion was sometimes followed by a gradual increase to a new concentration plateau. In sum, compared with bath application, microinjection can deliver about tenfold higher transmitter concentrations, but to much more restricted areas of the spinal cord. PMID:17634342

  17. [Study the restoration technology of concentrated application-natural diffusion about amendments of acidified soil of hilly woodland].

    PubMed

    Fang, Xiong; Liu, Ju-Xiu; Yin, Guang-Cai; Zhao, Liang; Liu, Shi-Zhong; Chu, Guo-Wei; Li, Yi-Yong

    2013-01-01

    Through concentrated application of lime, sewage sludge and lime + sewage sludge on the sloping top of the hilly woodlands, the restoration effects of the three soil amendments on the acidified soil of hilly woodland were studied. The results showed that: (1) Joint application of sewage sludge + lime can significantly (P < 0.05) decrease soil acidity, promote the rapid increase in soil organic matter and nitrogen content, increase soil cation exchange capacity, and effectively improve acidified soil. (2) Through natural diffusion mechanisms of surface and subsurface runoff, a large area of acidified soil of hilly woodlands can be restored by concentrated application of soil amendments on the sloping top of the hilly woodlands. (3) It is conducive to solve the pollution problems of the urban sewage sludge by using municipal sewage sludge to restore acidified soil, but only for the restoration of acidified soil of timber forest. PMID:23487954

  18. Increasing Selenium and Yellow Pigment Concentrations in Foxtail Millet (Setaria italica L.) Grain with Foliar Application of Selenite.

    PubMed

    Ning, Na; Yuan, Xiang-Yang; Dong, Shu-Qi; Wen, Yin-Yuan; Gao, Zhen-Pan; Guo, Mei-Jun; Guo, Ping-Yi

    2016-03-01

    Although addition of selenium (Se) is known to increase Se in crops, it is unclear whether exogenous Se is linked to nutritional and functional components in foxtail millet (Setaria italica L.). In this study, we examined the potential of increasing Se and yellow pigment (YP) in foxtail millet grain by foliar application of Se. Field experiments were conducted during the growing season of foxtail millet in 2013 and 2014 to assess the effects of foliar spray of sodium selenite (10-210 g Se ha(-1)) on the yield, Se uptake and accumulation, total YP, and microminerals in the grain. Average grain yields with Se application were 5.60 and 4.53 t ha(-1) in the 2 years, showing no significant differences from the unfertilized control. However, grain Se concentration increased linearly with Se application rate, by 8.92 and 6.09 μg kg(-1) in the 2 years with application of 1 g Se ha(-1) (maximum grain recovery rates of Se fertilizer, 52 and 28 %). Likewise, total grain YP concentration markedly increased by 0.038 and 0.031 mg kg(-1) in the 2 years with application of 1 g Se ha(-1). Grain Mn, Cu, Fe, and Zn concentrations were not significantly affected by Se application. This study indicated that foliar application of Se effectively and reliably increased the concentrations of Se and YP in foxtail millet grain without affecting the yield or mineral micronutrient concentrations. Thus, foliar-applied selenite has a significant potential to increase the concentrations of selenium and YP (putative lutein (Shen, J Cereal Sci 61:86-93, 2015; Abdel-Aal, Cereal Chem 79:455-457, 2002; Abdel-Aal, J Agric Food Chem 55:787-794, 2007)) of foxtail millet and, thus, the health benefits of this crop. PMID:26201681

  19. Six-man, self-contained carbon dioxide concentrator subsystem for Space Station Prototype (SSP) application

    NASA Technical Reports Server (NTRS)

    Kostell, G. D.; Schubert, F. H.; Shumar, J. W.; Hallick, T. M.; Jensen, F. C.

    1974-01-01

    A six man, self contained, electrochemical carbon dioxide concentrating subsystem for space station prototype use was successfully designed, fabricated, and tested. A test program was successfully completed which covered shakedown testing, design verification testing, and acceptance testing.

  20. Structure and Electroanalytical Application of Nitrogen-doped Carbon Thin Film Electrode with Lower Nitrogen Concentration.

    PubMed

    Kamata, Tomoyuki; Kato, Dai; Umemura, Shigeru; Niwa, Osamu

    2015-01-01

    We studied a nitrogen-doped nanocarbon film electrode with a nitrogen concentration of lower than 10.9 at% formed by the unbalanced magnetron (UBM) sputtering method. The sp(3) content in the nitrogen-doped UBM sputtering nanocarbon film (N-UBM film) slightly increases with increasing nitrogen concentration. The nitrogen-containing graphite-like bonding decreases and pyridine-like bonding increases with increasing nitrogen concentration. The N-UBM film has a very smooth surface with an average roughness of 0.1 to 0.3 nm, which is almost independent of nitrogen concentration. The N-UBM film electrode shows a wider potential window (4.1 V) than a pure-UBM film electrode (3.9 V) due to its slight increase in the sp(3) content. The electrocatalytic activity increased with increasing nitrogen concentration, suggesting that the electroactivity is maximum when the nitrogen concentration is around 10.9 at%, which is confirmed by the peak separation of Fe(CN)6(4-). The hydrogen peroxide (H2O2) reduction potentials at the N-UBM film electrode shifted about 0.1 V, and the peak current of H2O2 increased about 4 times. PMID:26165287

  1. Pressure Effects on Oxygen Concentration Flammability Thresholds of Materials for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Hirsch, David; Williams, Jim; Beeson, Harold

    2006-01-01

    Spacecraft materials selection is based on an upward flammability test conducted in a quiescent environment in the highest-expected oxygen-concentration environment. However, NASA s advanced space exploration program is anticipating using various habitable environments. Because limited data is available to support current program requirements, a different test logic is suggested to address these expanded atmospheric environments through the determination of materials self-extinguishment limits. This paper provides additional pressure effects data on oxygen concentration and partial pressure self-extinguishment limits under quiescent conditions. For the range of total pressures tested, the oxygen concentration and oxygen partial pressure flammability thresholds show a near linear function of total pressure. The oxygen concentration/oxygen partial pressure flammability thresholds depend on the total pressure and appear to increase with increasing oxygen concentration (and oxygen partial pressure). For the Constellation Program, the flammability threshold information will allow NASA to identify materials with increased flammability risk because of oxygen concentration and total pressure changes, minimize potential impacts, and allow for development of sound requirements for new spacecraft and extraterrestrial landers and habitats.

  2. Concentration and intervals of hydrogen dioxide applications to control Puccinia hemerocallidis on daylily.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ZeroTol is a disinfestant labeled for direct application on plants. Laboratory, field, and greenhouse experiments were performed to determine the rates and intervals in days between applications needed to control daylily rust. In laboratory trials, a very high rate was required to achieve 100% morta...

  3. Influence of concentration, time and method of application of citric acid and sodium citrate in root conditioning

    PubMed Central

    CAVASSIM, Rodrigo; LEITE, Fábio Renato Manzolli; ZANDIM, Daniela Leal; DANTAS, Andrea Abi Rached; RACHED, Ricardo Samih Georges Abi; SAMPAIO, José Eduardo Cezar

    2012-01-01

    Objective The aim of this study was to establish the parameters of concentration, time and mode of application of citric acid and sodium citrate in relation to root conditioning. Material and Methods A total of 495 samples were obtained and equally distributed among 11 groups (5 for testing different concentrations of citric acid, 5 for testing different concentrations of sodium citrate and 1 control group). After laboratorial processing, the samples were analyzed under scanning electron microscopy. A previously calibrated and blind examiner evaluated micrographs of the samples. Non-parametric statistical analysis was performed to analyze the data obtained. Results Brushing 25% citric acid for 3 min, promoted greater exposure of collagen fibers in comparison with the brushing of 1% citric acid for 1 minute and its topical application at 1% for 3 min. Sodium citrate exposed collagen fibers in a few number of samples. Conclusion Despite the lack of statistical significance, better results for collagen exposure were obtained with brushing application of 25% citric acid for 3 min than with other application parameter. Sodium citrate produced a few number of samples with collagen exposure, so it is not indicated for root conditioning. PMID:22858707

  4. Application research of computational mass-transfer differential equation in MBR concentration field simulation.

    PubMed

    Li, Chunqing; Tie, Xiaobo; Liang, Kai; Ji, Chanjuan

    2016-01-01

    After conducting the intensive research on the distribution of fluid's velocity and biochemical reactions in the membrane bioreactor (MBR), this paper introduces the use of the mass-transfer differential equation to simulate the distribution of the chemical oxygen demand (COD) concentration in MBR membrane pool. The solutions are as follows: first, use computational fluid dynamics to establish a flow control equation model of the fluid in MBR membrane pool; second, calculate this model by adopting direct numerical simulation to get the velocity field of the fluid in membrane pool; third, combine the data of velocity field to establish mass-transfer differential equation model for the concentration field in MBR membrane pool, and use Seidel iteration method to solve the equation model; last but not least, substitute the real factory data into the velocity and concentration field model to calculate simulation results, and use visualization software Tecplot to display the results. Finally by analyzing the nephogram of COD concentration distribution, it can be found that the simulation result conforms the distribution rule of the COD's concentration in real membrane pool, and the mass-transfer phenomenon can be affected by the velocity field of the fluid in membrane pool. The simulation results of this paper have certain reference value for the design optimization of the real MBR system. PMID:27375999

  5. Application of laser Raman spectroscopy in concentration measurements of multiple analytes in human body fluids

    NASA Astrophysics Data System (ADS)

    Qu, Jianan Y.; Suria, David; Wilson, Brian C.

    1998-05-01

    The primary goal of these studies was to demonstrate that NIR Raman spectroscopy is feasible as a rapid and reagentless analytic method for clinical diagnostics. Raman spectra were collected on human serum and urine samples using a 785 nm excitation laser and a single-stage holographic spectrometer. A partial east squares method was used to predict the analyte concentrations of interest. The actual concentrations were determined by a standard clinical chemistry. The prediction accuracy of total protein, albumin, triglyceride and glucose in human sera ranged from 1.5 percent to 5 percent which is greatly acceptable for clinical diagnostics. The concentration measurements of acetaminophen, ethanol and codeine inhuman urine have demonstrated the potential of NIR Raman technology in screening of therapeutic drugs and substances of abuse.

  6. Application of quantitative estimates of fecal hemoglobin concentration for risk prediction of colorectal neoplasia

    PubMed Central

    Liao, Chao-Sheng; Lin, Yu-Min; Chang, Hung-Chuen; Chen, Yu-Hung; Chong, Lee-Won; Chen, Chun-Hao; Lin, Yueh-Shih; Yang, Kuo-Ching; Shih, Chia-Hui

    2013-01-01

    AIM: To determine the role of the fecal immunochemical test (FIT), used to evaluate fecal hemoglobin concentration, in the prediction of histological grade and risk of colorectal tumors. METHODS: We enrolled 17881 individuals who attended the two-step colorectal cancer screening program in a single hospital between January 2010 and October 2011. Colonoscopy was recommended to the participants with an FIT of ≥ 12 ngHb/mL buffer. We classified colorectal lesions as cancer (C), advanced adenoma (AA), adenoma (A), and others (O) by their colonoscopic and histological findings. Multiple linear regression analysis adjusted for age and gender was used to determine the association between the FIT results and colorectal tumor grade. The risk of adenomatous neoplasia was estimated by calculating the positive predictive values for different FIT concentrations. RESULTS: The positive rate of the FIT was 10.9% (1948/17881). The attendance rate for colonoscopy was 63.1% (1229/1948). The number of false positive results was 23. Of these 1229 cases, the numbers of O, A, AA, and C were 759, 221, 201, and 48, respectively. Regression analysis revealed a positive association between histological grade and FIT concentration (β = 0.088, P < 0.01). A significant log-linear relationship was found between the concentration and positive predictive value of the FIT for predicting colorectal tumors (R2 > 0.95, P < 0.001). CONCLUSION: Higher FIT concentrations are associated with more advanced histological grades. Risk prediction for colorectal neoplasia based on individual FIT concentrations is significant and may help to improve the performance of screening programs. PMID:24363529

  7. Application of chemometric studies to metal concentrations in molluscs from the Strait of Magellan (Chile).

    PubMed

    España, M S Astorga; Rodríguez, E M Rodríguez; Romero, C Díaz

    2007-05-01

    Na, K, Ca, Mg, Fe, Cu, Zn, Mn, Se, Ni, and Cd concentrations were determined in 126 mollusc samples belonging to five different species (Mytilus chilensis, n = 47; Nacella deaurata, n = 65; Aulacomya ater, n = 4; Fissurella picta, n = 4; Acanthina monodon, n = 6) collected from the coasts of the Strait of Magellan. The metals analysed presented significant differences between the mean concentrations for the mollusc species considered. Factor and discriminant analyses made possible the differentiation of the mollusc species. In addition, when discriminant analysis was used, good classifications were obtained according to sampling zone and weight-to-length ratio of the organisms. PMID:17375348

  8. Diethylene glycol mono butyl ether concentrations in room air from application of cleaner formulations to hard surfaces.

    PubMed

    Gibson, W B; Keller, P R; Foltz, D J; Harvey, G J

    1991-07-01

    Diethylene glycol monobutyl ether (DGBE) is a solvent used in some liquid hard surface cleaners. We evaluated the inhalation component of consumer exposure in the home to DGBE from the use of cleaning products containing up to 9% DGBE. Several experiments were conducted with restricted room air flow, exaggerated amounts of cleaning solutions, and no rinsing in order to develop an exposure scenario that would exceed exposures likely encountered by consumers. DGBE vapors in the air were monitored by collection on charcoal tubes, followed by desorption and quantitation by gas chromatography. Air was collected from the centre of the room and from the breathing zone of the person doing the washing task. Room air concentrations of DGBE showed peak values between one and three hours after task initiation; DGBE concentrations then gradually decreased with time. Peak concentrations did not exceed 1.6 ppmv. The total DGBE in the air at the time of maximum air concentrations accounted for only 1 to 3% of the DGBE on the washed surfaces. The person doing the washing task was exposed to average DGBE concentrations in the breathing zone below 0.8 ppmv in all experiments. The methods described for measuring DGBE concentrations in air are generally applicable to other solvents and easily adaptable to various experimental situations. PMID:1824325

  9. Relative potentials of concentrating and two-axis tracking flat-plate photovoltaic arrays for central-station applications

    NASA Technical Reports Server (NTRS)

    Borden, C. S.; Schwartz, D. L.

    1984-01-01

    The purpose of this study is to assess the relative economic potentials of concenrating and two-axis tracking flat-plate photovoltaic arrays for central-station applications in the mid-1990's. Specific objectives of this study are to provide information on concentrator photovoltaic collector probabilistic price and efficiency levels to illustrate critical areas of R&D for concentrator cells and collectors, and to compare concentrator and flat-plate PV price and efficiency alternatives for several locations, based on their implied costs of energy. To deal with the uncertainties surrounding research and development activities in general, a probabilistic assessment of commercially achievable concentrator photovoltaic collector efficiencies and prices (at the factory loading dock) is performed. The results of this projection of concentrator photovoltaic technology are then compared with a previous flat-plate module price analysis (performed early in 1983). To focus this analysis on specific collector alternatives and their implied energy costs for different locations, similar two-axis tracking designs are assumed for both concentrator and flat-plate options.

  10. MRI profiles over very wide concentration ranges: application to swelling of a bentonite clay.

    PubMed

    Dvinskikh, S V; Szutkowski, K; Furó, I

    2009-06-01

    In MRI investigation of soils, clays, and rocks, mainly mobile water is detected, similarly to that in biological and medical samples. However, the spin relaxation properties of water in these materials and/or low water concentration may make it difficult to use standard MRI approaches. Despite these limitations, one can combine MRI techniques developed for solid and liquid states and use independent information on relaxation properties of water, interacting with the material of interest, to obtain true images of both water and material content. We present procedures for obtaining such true density maps and demonstrate their use for studying the swelling of bentonite clay by water. A constant time imaging protocol provides 1D mapping of the clay distribution in regions with clay concentration above 10 vol%. T(1) relaxation time imaging is employed to monitor the clay content down to 10(-3) vol%. Data provided by those two approaches are in good agreement in the overlapping range of concentrations. Covering five orders of magnitude of clay concentration, swelling of sodium-exchanged bentonite clays from pre-compacted pellets into a gel phase is followed in detail. PMID:19233697

  11. MRI profiles over very wide concentration ranges: Application to swelling of a bentonite clay

    NASA Astrophysics Data System (ADS)

    Dvinskikh, S. V.; Szutkowski, K.; Furó, I.

    2009-06-01

    In MRI investigation of soils, clays, and rocks, mainly mobile water is detected, similarly to that in biological and medical samples. However, the spin relaxation properties of water in these materials and/or low water concentration may make it difficult to use standard MRI approaches. Despite these limitations, one can combine MRI techniques developed for solid and liquid states and use independent information on relaxation properties of water, interacting with the material of interest, to obtain true images of both water and material content. We present procedures for obtaining such true density maps and demonstrate their use for studying the swelling of bentonite clay by water. A constant time imaging protocol provides 1D mapping of the clay distribution in regions with clay concentration above 10 vol%. T1 relaxation time imaging is employed to monitor the clay content down to 10 -3 vol%. Data provided by those two approaches are in good agreement in the overlapping range of concentrations. Covering five orders of magnitude of clay concentration, swelling of sodium-exchanged bentonite clays from pre-compacted pellets into a gel phase is followed in detail.

  12. Adsorption behavior of low concentration carbon monoxide on polymer electrolyte fuel cell anodes for automotive applications

    NASA Astrophysics Data System (ADS)

    Matsuda, Yoshiyuki; Shimizu, Takahiro; Mitsushima, Shigenori

    2016-06-01

    The adsorption behavior of CO on the anode around the concentration of 0.2 ppm allowed by ISO 14687-2 is investigated in polymer electrolyte fuel cells (PEFCs). CO and CO2 concentrations in the anode exhaust are measured during the operation of a JARI standard single cell at 60 °C cell temperature and 1000 mA cm-2 current density. CO coverage is estimated from the gas analysis and CO stripping voltammetry. The cell voltage decrease as a result of 0.2 ppm CO is 29 mV and the CO coverage is 0.6 at the steady state with 0.11 mg cm-2 of anode platinum loading. The CO coverage as a function of CO concentration approximately follows a Temkin-type isotherm. Oxygen permeated to the anode through a membrane is also measured during fuel cell operation. The exhaust velocity of oxygen from the anode was shown to be much higher than the CO supply velocity. Permeated oxygen should play an important role in CO oxidation under low CO concentration conditions.

  13. Method and apparatus for uniformly concentrating solar flux for photovoltaic applications

    DOEpatents

    Jorgensen, Gary J.; Carasso, Meir; Wendelin, Timothy J.; Lewandowski, Allan A.

    1992-01-01

    A dish reflector and method for concentrating moderate solar flux uniformly on a target plane on a solar cell array, the dish having a stepped reflective surface that is characterized by a plurality of ring-like segments arranged about a common axis, and each segment having a concave spherical configuration.

  14. Quantifying Gold Nanoparticle Concentration in a Dietary Supplement Using Smartphone Colorimetry and Google Applications

    ERIC Educational Resources Information Center

    Campos, Antonio R.; Knutson, Cassandra M.; Knutson, Theodore R.; Mozzetti, Abbie R.; Haynes, Christy L.; Penn, R. Lee

    2016-01-01

    Spectrophotometry and colorimetry experiments are common in high school and college chemistry courses, and nanotechnology is increasingly common in every day products and new devices. Previous work has demonstrated that handheld camera devices can be used to quantify the concentration of a colored analyte in solution in place of traditional…

  15. Low concentration ratio solar array for low Earth orbit multi-100 kW application

    NASA Technical Reports Server (NTRS)

    Nalbandian, S. J.

    1982-01-01

    An ongoing preliminary design effort directed toward a low-concentration-ratio photovoltaic array system based on 1984 technology and capable of delivering multi-hundred kilowatts (300 kW to 1000 kW range) in low earth orbit is described. The array system consists of two or more array modules each capable of delivering between 80 kW to 172 kW using silicon solar cells or gallium arsenide solar cells respectively. The array module deployed area is 1320 square meters and consists of 4356 pryamidal concentrator elements. The module, when stowed in the Space Shuttle's payload bay, has a stowage volume of a cube with 3.24 meters on a side. The concentrator elements are sized for a geometric concentration ratio (GCR) of six with an aperture area of 0.5 meters x 0.5 meters. The structural analysis and design trades leading to the baseline design are discussed. The configuration, as well as optical, thermal and electrical performance analyses that support the design and overall performance estimates for the array are described.

  16. Application of gas chromatographic method in simultaneous measurements of helium, argon and neon concentration in groundwaters

    NASA Astrophysics Data System (ADS)

    Najman, J.; Bielewski, J.; Sliwka, I.

    2012-04-01

    Helium concentration in groundwater is a fine indicator in water dating in a range from a hundred to tens of thousands of years. Gas chromatography (GC) measurements of helium can be used as an alternative to mass spectrometry (MS) determinations of 4He for groundwater dating [1]. Argon and neon concentrations mainly serve for determining the temperature of recharge and the air excess which is needed to correct measured values of helium concentration [2] . A chromatographic measurement system of helium, argon and neon concentration in groundwater is presented [3]. Water samples are taken from groundwater with a precise procedure without contamination with air in a special stainless steel vessels of volume equal to 2900 cm3. Helium is extracted from water samples using the head-space method. After enrichment by cryotrap method helium is analyzed in the gas chromatograph equipped with the thermal conductivity detector (TCD) with detection limit of about 2.8 ng He. The helium limit of detection of presented method is 1,2·10-8 cm3STP/gH2O [4]. We are currently working on adapting the method of cryogenic enrichment of helium concentration for simultaneous measurements of the concentration of helium, argon and neon using single sample of groundwater. Neon will be measured with the thermal conductivity detector and capillary column filled with molecular sieve 5A. Argon will be analyzed also with the thermal conductivity detector and packed column filled with molecular sieve 5A. This work was supported by grant No. N N525 3488 38 from the polish National Science Centre. [1] A. Zuber, W. Ciężkowski, K. Różański (red.), Tracer methods in hydrogeological studies - a methodological guide. Wroclaw University of Technology Publishing House, Wroclaw, 2007 (in polish). [2] P. Mochalski, Chromatographic method for the determination of Ar, Ne and N2 in water, Ph.D. thesis, Institute of Nuclear Physics Polish Academy of Sciences in Krakow, 2003 (in polish). [3] A. Żurek, P

  17. Shielding of longitudinal magnetic fields with thin, closely, spaced concentric cylindrical shells with applications to atomic clocks

    NASA Technical Reports Server (NTRS)

    Wolf, S. A.; Gubser, D. U.; Cox, J. E.

    1978-01-01

    A general formula is given for the longitudinal shielding effectiveness of N closed concentric cylinders. The use of these equations is demonstrated by application to the design of magnetic shields for hydrogen maser atomic clocks. Examples of design tradeoffs such as size, weight, and material thickness are discussed. Experimental results on three sets of shields fabricated by three manufacturers are presented. Two of the sets were designed employing the techniques described. Agreement between the experimental results and the design calculations is then demonstrated.

  18. Two-zone model application to breathing zone and area welding fume concentration data.

    PubMed

    Boelter, Fred W; Simmons, Catherine E; Berman, Laurel; Scheff, Peter

    2009-05-01

    This study assessed a professional pipefitter/welder performing shielded metal arc welding on carbon steel under field conditions. The resulting breathing zone (near field) and area (far field) welding fume concentration data were applied to the two-zone model for the purpose of determining field-derived personal exposure emission (generation) rates during actual welding work. The study is unique in that one welder was evaluated under high production conditions for 2 days at two different welding locations: a boiler room and a breezeway. Samples were collected and analyzed for total particulate following NIOSH Method 0500 and for select metals following NIOSH Method 7300. Breezeway average personal breathing zone sample total particulate concentrations ranged from 2.89 mg/m(3) to 4.38 mg/m(3), Fe concentrations ranged from 0.53 to 0.63 mg/m(3), and Mn concentrations ranged from 0.10 to 0.12 mg/m(3). The boiler room average personal breathing zone sample total particulate concentrations ranged from 4.73 mg/m(3) to 5.90 mg/m(3), Fe concentrations ranged from 0.48 to 0.85 mg/m(3), and Mn concentrations ranged from 0.06 to 0.16 mg/m(3). Average arc times ranged from 20 to 25% of the total sampling time. Both tracer gas and anemometer techniques were used to estimate ventilation of the boiler room. The steady-state form of the two-zone model was applied to long-term and short-term sample total particulate, Fe, and Mn concentrations obtained during welding in the boiler room and breezeway. The average generation rate in the boiler room was 39.2 mg/min for TP, 6.4 mg/min for Fe, and 1.3 mg/min for Mn. The average generation rate in the breezeway was 40.0 mg/min for TP, 6.6 mg/min for Fe, and 1.2 mg/min for Mn. The field-based generation rates were considerably lower than laboratory-derived published emission rates of between 280 and 650 mg/min for TP. This study emphasizes the need for field-derived welding fume generation rates and showed the personal breathing zone and

  19. Effects of dermal dexamethasone application on ACTH and both basal and ACTH-stimulated cortisol concentration in normal horses.

    PubMed

    Abraham, G; Allersmeier, M; Gottschalk, J; Schusser, G F; Hoppen, H-O; Ungemach, F R

    2009-08-01

    There are no data available regarding the systemic (adverse) effects which might be induced by topical/dermal glucocorticoids (GCs) application in the horse. Besides their widespread use for the treatment of a variety of peripheral inflammatory disorders such as atopic dermatitis, eczemas or arthritis in the horse, their surreptitious application has become a concern in doping cases in competition/performance horses. Assessing both basal and ACTH-stimulated plasma cortisol as well as basal ACTH concentrations following application of dexamethsone-containing dermal ointment is necessary to determine influences on hypothalamus-pituitary-adrenal (HPA) axis. Ten clinically healthy adult standardbred horses (6 mares, 4 geldings) were rubbed twice daily each with 50 g dexamethasone-containing ointment on a defined skin area (30 x 50 cm) for 10 days. RIA and chemiluminescent enzyme immuno-metric assay were used to determine resting and ACTH-stimulated plasma cortisol and basal ACTH concentrations, respectively. HPA feedback sensitivity and adrenal function were measured by a standard ACTH stimulation test. Dermal dexamethasone suppressed significantly the resting plasma cortisol level (to 75-98%) below baseline (P < 0.001) within the first 2 days and decreased further until day 10. ACTH stimulation test showed a markedly reduced rise in plasma cortisol concentrations (P < 0.001 vs. baseline). Plasma ACTH level decreased also during topical dexamethasone application. The number of total lymphocytes and eosinophil granulocytes was reduced, whereas the number of neutrophils increased. No significant change of serum biochemical parameters was noted. Dermal dexamethasone application has the potential to cause an almost complete and transient HPA axis suppression and altered leukocyte distribution in normal horses. The effects on HPA axis function should be considered in relation to the inability of animals to resist stress situations. The data further implicate that

  20. Accelerated Stress Testing of Hydrocarbon-Based Encapsulants for Medium-Concentration CPV Applications

    SciTech Connect

    Kempe, M. D.; Moricone, T. J.; Kilkenny, M.; Zhang, J. Z.

    2011-02-01

    Concentrating photovoltaic (CPV) systems have great potential to reduce photovoltaic (PV) electricity costs because of the relatively low cost of optical components as compared to PV cells. A transparent polymeric material is used to optically couple the PV cell to optical components and is thus exposed to the concentrated light source at elevated temperatures. In this work polymeric encapsulant materials are positioned close to a Xenon arc lamp to expose them to ultraviolet radiation (UV) that is about 42 times as intense as sunlight. Furthermore, different glass types are used as filters to modify the spectral distribution of light in the UV range. A strong sensitivity of non-silicone-based encapsulants to light below ~350 nm is demonstrated. Of all the materials examined in this study, the polydimethyl silicone samples performed the best. The next best material was an ionomer which maintained optical transmission but became photo-oxidized where exposed to the atmosphere.

  1. Applications of Kalman filtering to real-time trace gas concentration measurements

    NASA Technical Reports Server (NTRS)

    Leleux, D. P.; Claps, R.; Chen, W.; Tittel, F. K.; Harman, T. L.

    2002-01-01

    A Kalman filtering technique is applied to the simultaneous detection of NH3 and CO2 with a diode-laser-based sensor operating at 1.53 micrometers. This technique is developed for improving the sensitivity and precision of trace gas concentration levels based on direct overtone laser absorption spectroscopy in the presence of various sensor noise sources. Filter performance is demonstrated to be adaptive to real-time noise and data statistics. Additionally, filter operation is successfully performed with dynamic ranges differing by three orders of magnitude. Details of Kalman filter theory applied to the acquired spectroscopic data are discussed. The effectiveness of this technique is evaluated by performing NH3 and CO2 concentration measurements and utilizing it to monitor varying ammonia and carbon dioxide levels in a bioreactor for water reprocessing, located at the NASA-Johnson Space Center. Results indicate a sensitivity enhancement of six times, in terms of improved minimum detectable absorption by the gas sensor.

  2. Laboratory application of laser grain-size analyzer in determining suspended sediment concentration

    NASA Astrophysics Data System (ADS)

    Liu, Xiao; Feng, Xiuli; Liu, Jie; Lin, Lin

    2014-06-01

    Suspended sediment concentration (SSC) is an important parameter in marine sedimentology. With the development of technology, many acoustic and optical devices, such as the Laser In-Situ Scattering and Transmissometry, have been designed to measure in situ SSC and grain size distribution. But due to fund or other restrictions, many experiments were only conducted in laboratory, using an indoor laser grain-size analyzer and gravimetric method to measure grain size distribution and concentration, respectively. In this study the laboratory experiment is simplified by omitting the tiring step of gravimetric method. The connections between SSC and other parameters (obscuration, D50 and sorting index) were investigated based on 124 surface sediment samples collected from different offshore areas. A new method is developed for determining SSC in laboratory using a laser grain-size analyzer.

  3. Dealing with disjunct concentration measurements in eddy covariance applications: a comparison of available approaches

    PubMed Central

    Hörtnagl, Lukas; Clement, Robert; Graus, Martin; Hammerle, Albin; Hansel, Armin; Wohlfahrt, Georg

    2013-01-01

    Using proton transfer reaction mass spectrometry equipped with a quadrupol mass analyser to quantify the biosphere-atmosphere exchange of volatile organic compounds (VOC), concentrations of different VOC are measured sequentially. Depending on how many VOC species are targeted and their respective integration times, each VOC is measured at repeat rates on the order of a few seconds. This represents an order of magnitude longer sample interval compared to the standard eddy covariance (EC) method (5-20 Hz sampling rates). Here we simulate the effect of disjunct sampling on EC flux estimates by decreasing the time resolution of CO2 and H2O concentrations measured at 20 Hz above a temperate mountain grassland in the Austrian Alps. Fluxes for one month are calculated with the standard EC method and compared to fluxes calculated based on the disjunct data (1, 3 and 5 s sampling rates) using the following approaches: i) imputation of missing concentrations based on the nearest neighbouring samples (iDECnn), ii) imputation by linear interpolation (iDECli), and iii) virtual disjunct EC (vDEC), i.e. flux calculation based solely on the disjunct concentrations. It is shown that the two imputation methods result in additional low-pass filtering, longer lag times (as determined with the maximum cross-correlation method) and a flux loss of 3-30 % as compared to the standard EC method. A novel procedure, based on a transfer function approach, which specifically corrects for the effect of data treatment, was developed, resulting in improved correspondence (to within 2 %). The vDEC method yields fluxes which approximate the true (20 Hz) fluxes to within 3-7 % and it is this approach we recommend because it involves no additional empirical corrections. The only drawback of the vDEC method is the noisy nature of the cross-correlations, which poses problems with lag determination – practical approaches to overcome this limitation are discussed. PMID:24339727

  4. Onsager's reciprocal relations for electroacoustic and sedimentation: Application to (concentrated) colloidal suspensions

    NASA Astrophysics Data System (ADS)

    Gourdin-Bertin, S.; Chassagne, C.

    2015-05-01

    In this article, the relations for electroacoustic phenomena, such as sedimentation potential, sedimentation intensity, colloid vibration potential, colloid vibration intensity/current, or electric sonic amplitude, are given, on the basis of irreversible thermodynamics. This formalism allows in particular to discuss the different expressions for concentrated suspensions found by various authors, which are of great practical interest. It was found that some existing expressions have to be corrected. Relations between the electrophoretic mobilities assessed by the different experiments are derived.

  5. Onsager’s reciprocal relations for electroacoustic and sedimentation: Application to (concentrated) colloidal suspensions

    SciTech Connect

    Gourdin-Bertin, S.; Chassagne, C.

    2015-05-21

    In this article, the relations for electroacoustic phenomena, such as sedimentation potential, sedimentation intensity, colloid vibration potential, colloid vibration intensity/current, or electric sonic amplitude, are given, on the basis of irreversible thermodynamics. This formalism allows in particular to discuss the different expressions for concentrated suspensions found by various authors, which are of great practical interest. It was found that some existing expressions have to be corrected. Relations between the electrophoretic mobilities assessed by the different experiments are derived.

  6. Application of NMR Spectroscopy to the Determination of Low Concentrations of Nonradioactive Isotopes in Liquid Media

    NASA Astrophysics Data System (ADS)

    Dzhimak, S. S.; Basov, A. A.; Kopytov, G. F.; Kashaev, D. V.; Sokolov, M. E.; Artsybasheva, O. M.; Sharapov, K. S.; Baryshev, M. G.

    2015-11-01

    A method is developed for measuring the content of hydrogen (2H) and oxygen (17O) isotopes in liquid media based on quantitative nuclear magnetic resonance. It has been established that the shifting europium trifluoromethanesulfonate (III) reagent is the most appropriate chemical compound for a reference sample to study the isotopic composition of aqueous solutions. A dependence of the paramagnetic chemical shift of 2H and 17O nuclei on the concentration of Eu3+ ions in a solution is studied.

  7. Development of a Reagentless Biosensor for Inorganic Phosphate, Applicable over a Wide Concentration Range.

    PubMed

    Solscheid, Claudia; Kunzelmann, Simone; Davis, Colin T; Hunter, Jackie L; Nofer, Annie; Webb, Martin R

    2015-08-18

    A fluorescent reagentless biosensor for inorganic phosphate (Pi), based on the E. coli PstS phosphate binding protein, was redesigned to allow measurements of higher Pi concentrations and at low, substoichiometric concentrations of biosensor. This was achieved by weakening Pi binding of the previous biosensor, and different approaches are described that could enable this change in properties. The readout, providing response to the Pi concentration, is delivered by tetramethylrhodamine fluorescence. In addition to two cysteine mutations for rhodamine labeling at positions 17 and 197, the final variant had an I76G mutation in the hinge region between the two lobes that make up the protein. Upon Pi binding, the lobes rotate on this hinge and the mutation on the hinge lowers affinity ∼200-fold, with a dissociation constant now in the tens to hundreds micromolar range, depending on solution conditions. The signal change on Pi binding was up to 9-fold, depending on pH. The suitability of the biosensor for steady-state ATPase assays was demonstrated with low biosensor usage and its advantage in ability to cope with Pi contamination. PMID:26199994

  8. Testing of a prototype Fresnel-lens concentrator for thermal applications

    SciTech Connect

    Lewandowski, A.

    1983-02-01

    A prototype Fresnel-lens concentrator, manufactured by E-Systems, Dallas, Texas, was tested for thermal performance at SERI's Mid-Temperature Collector Research Facility (MTCRF). This work was funded by the DOE in an effort to support development of a testing standard for concentrators. The data obtained from this testing were presented and utilized by a subcommittee of the American Society for Testing and Materials (ASTM) in the development process for the standard. Several tests were conducted on the concentrator using draft versions of the standard as guidance. Additional tests allowed but not required by the standard were conducted to determine the effect of the direct solar irradiance level on collector performance. It is the results of these additional tests that are of primary interest. The data show that non-linear heat losses cause collector efficiency to be a function of both ..delta..t/I/sub DN/ and I/sub DN/ and that the efficiency when fluid temperature is near ambient is also a function of I/sub DN/. This latter result is a characteristic unique to this collector, whereas the former holds for any collector with non-linear with heat loss.

  9. Subsurface Band Application of Poultry Litter and Its Influence on Phosphorus Concentration and Retention after Runoff from Permanent Pastures.

    PubMed

    Watts, Dexter B; Way, Thomas R; Torbert, H Allen; Armstrong, Shalamar D

    2015-11-01

    Excessive phosphorus (P) loss from agricultural fields is a major cause of eutrophication to rivers, lakes, and streams. To mitigate P loss after poultry litter (PL) applications, technology is being developed to apply litter below the soil surface. Thus, research was conducted to evaluate the effects of subsurface PL banding on soil P under pasture management. Treatments consisted of surface-broadcasted or subsurface-banded PL (38 cm apart) at 9 Mg ha, surface-broadcasted commercial fertilizer (CF; urea and triple superphosphate blend) at N (330 kg N ha) and P (315 kg N ha) application rates equivalent to PL, and a nonfertilized control. Runoff events lasting 40 min were simulated in bermudagrass ( L.) pastures on common soil types of the Coastal Plain and Piedmont regions. One day later, Mehlich-1 and water-soluble P concentrations in soil were measured at depths of 0 to 5 cm and 5 to 10 cm to determine P distribution and movement. The greatest P concentrations were observed at the shallow depth for all treatments. Phosphorus measurements at the point of application for PL bands were greater than for the surface-applied treatments (PL and CF) and control. Measurements between subsurface PL bands were slightly higher than the control but were statistically similar, suggesting that this application method can abate short-term P movement. Results obtained from this study show that subsurface band applying PL could increase P retention and reduce movement by precluding contact between surface water and litter nutrients. PMID:26641345

  10. Corn response and soil nutrient concentration from subsurface application of poultry litter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrogen fertilizer management is vital to corn (Zea mays L.) production from financial and environmental perspectives. Poultry litter as a nutrient source in this cropping system is generally surface broadcast, potentially causing volatilization of NH3. Recently a new application method was devel...

  11. Performance and cost benefits associated with nonimaging secondary concentrators used in point-focus dish solar thermal applications

    SciTech Connect

    O'Gallagher, J.; Winston, R.

    1987-09-01

    Using nonimaging secondary concentrators in point-focus applications may permit the development of more cost-effective concentrator systems by either improving performance or reducing costs. Secondaries may also increase design flexibility. The major objective of this study was to develop as complete an understanding as possible of the quantitative performance and cost effects associated with deploying nonimaging secondary concentrators at the focal zone of point-focus solar thermal concentrators. A performance model was developed that uses a Monte Carlo ray-trace procedure to determine the focal plane distribution of a paraboloidal primary as a function of optical parameters. It then calculates the corresponding optimized concentration and thermal efficiency as a function of temperature with and without the secondary. To examine the potential cost benefits associated with secondaries, a preliminary model for the rational optimization of performance versus cost trade-offs was developed. This model suggests a possible 10% to 20% reduction in the cost of delivered energy when secondaries are used. This is a lower limit, and the benefits may even be greater if using a secondary permits the development of inexpensive primary technologies for which the performance would not otherwise be viable. 20 refs., 15 figs., 3 tabs.

  12. Ethanol in pre-surgical hand rubs: concentration and duration of application for achieving European Norm EN 12791.

    PubMed

    Suchomel, M; Rotter, M

    2011-03-01

    In Europe, ethanol is a common active agent in hand rub formulations and nowadays it is also recommended in guidelines for hand hygiene published by the Centers for Disease Control and Prevention and by the World Health Organization. However, data on the range of concentrations and durations of application providing a basis for passing the efficacy test of the European norm EN 12791 are still lacking. Therefore, the bactericidal efficacy of rubbing clean hands with pure ethanol in volume concentrations of 95%, 85% or 75% during 3 min was compared with that of the reference procedure of EN 12791 employing n-propanol 60% v/v for 3 min, immediately and 3h after disinfection. Ethanol 85% was also tested at a 5 min application. A Latin-square design was used with 20 randomly allotted volunteers. Whereas the mean immediate bacterial reductions caused by ethanol at concentrations of 75% (log RF 1.68) and 95% (log RF 2.70) were significantly less efficacious compared to that of the reference (log RF 3.27), at 85% they were not significantly less active with both applications, 3 and 5 min (log RFs 2.90 and 3.12, respectively). Three hours after antisepsis, the bacterial reduction on the gloved hand was only significantly less efficacious than that of the reference when 75% ethanol was used. It is concluded that ethanol-based hand rubs have a good chance of meeting the EN 12791 requirements if their ethanol concentration is >75% v/v but <95% v/v and if they are applied for at least 3 min. PMID:21190755

  13. Application of municipal sludge (biosolids) for agricultural purposes and groundwater nitrate concentrations

    SciTech Connect

    Welby, C.W. . Dept. of Marine, Earth and Atmospheric Sciences)

    1993-03-01

    One of the more popular means of handling sewage sludge from municipalities is its application to agricultural lands. A variety of crops are grown with the expectation that plants will utilize the nitrogen. However, a complex scenario allows some of the nitrate to move below root depth and eventually to the water table at depths of up to 30 ft. The City of Raleigh, NC injects sewage sludge ( residuals'', biosolids'') into soils derived largely from the Rolesville Granite in an area of typical rolling Piedmont topography. A 1975 background study of part of the site demonstrated differences in groundwater quality between areas farmed over a period of years and areas dominated by second-growth pine and harwood forests. Groundwater quality data collected semiannually between 1982 and 1988 show gradual buildup of nitrate in some fields; in others groundwater quality apparently remains unaffected by nitrate from the sludge. Monitoring well placement may play a role in these differences. Minimum time from the sludge application to an increase in groundwater nitrate is from 9 to 12 months. An ongoing study of a 12-acre field which lay fallow for a number of years prior to sludge application in 1990 demonstrates that some nitrate does move downward fairly rapidly, its movement being recorded in both the saprolite and groundwater. Comparison of nitrate content of groundwater from monitoring wells at a nearby dairy farm shows that normal agricultural practices may also increase the nitrate content of the shallow groundwater.

  14. The Concentration Dependence of the (Delta)s Term in the Gibbs Free Energy Function: Application to Reversible Reactions in Biochemistry

    ERIC Educational Resources Information Center

    Gary, Ronald K.

    2004-01-01

    The concentration dependence of (delta)S term in the Gibbs free energy function is described in relation to its application to reversible reactions in biochemistry. An intuitive and non-mathematical argument for the concentration dependence of the (delta)S term in the Gibbs free energy equation is derived and the applicability of the equation to…

  15. Fish-friendly prophylaxis/disinfection in aquaculture: Low concentration of peracetic acid is stress-free to the carp (Cyprinus carpio) after repeated applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Application of peracetic acid (PAA) at low concentrations has been proved to be a broad functional and eco-friendly prophylaxis/disinfection method against various fish pathogens. Therefore, regular applications of low concentration PAA is sufficient to control (potential) pathogens in recirculatin...

  16. [Optimization and application of method to determine plasma concentration of brucine].

    PubMed

    Wang, Dong-Yue; Chen, Jun; Cai, Bao-Chang

    2013-04-01

    The HPLC method for determining plasma concentration of brucine was optimized during the study on the effect of the extraction reagent, the extraction frequency and the volume of extraction solvent on the extraction recovery of brucine. The optimum sample treatment method was obtained in the study. Specifically, ammonia water was added, 4 mL extraction solvent (N-hexane-methylene chloride-isopropyl alcohol 65:30:5) were adopted to extract brucine for twice. The method to determine plasma concentration of brucine was applied in pharmacokinetic study to compare pharmacokinetic properties of intravenous injection (5 mg x kg(-1)) and transdermal administration (40 mg x kg(-1)) of brucine aqueous alkali. The results showed that both pharmacokinetic parameters of brucine after intravenous injection and transdermal administration were in conformity with the two-compartment model. After transdermal administration, the absolute bioavailability was calculated to be 18.72%. The optimized HPLC method can satisfy the demands of the pharmacokinetic study on brucine. PMID:23847961

  17. Application of PAH concentration profiles in lake sediments as indicators for smelting activity.

    PubMed

    Warner, Wiebke; Ruppert, Hans; Licha, Tobias

    2016-09-01

    The ability of lake sediment cores to store long-term anthropogenic pollution establishes them as natural archives. In this study, we focus on the influence of copper shale mining and smelting in the Mansfeld area of Germany, using the depth profiles of two sediment cores from Lake Süßer See. The sediment cores provide a detailed chronological deposition history of polycyclic aromatic hydrocarbons (PAHs) and heavy metals in the studied area. Theisen sludge, a fine-grained residue from copper shale smelting, reaches the lake via deflation by wind or through riverine input; it is assumed to be the main source of pollution. To achieve the comparability of absolute contaminant concentrations, we calculated the influx of contaminants based on the sedimentation rate. Compared to the natural background concentrations, PAHs are significantly more enriched than heavy metals. They are therefore more sensitive and selective for source apportionment. We suggest two diagnostic ratios of PAHs to distinguish between Theisen sludge and its leachate: the ratio fluoranthene to pyrene ~2 and the ratio of PAH with logKOW<5.7 to PAH with a logKOW>5.7 converging to an even lower value than 2.3 (the characteristic of Theisen sludge) to identify the particulate input in lake environments. PMID:27176930

  18. Re-expansion method for circular waveguide discontinuities: Application to concentric expansion chambers

    PubMed Central

    Homentcovschi, Dorel; Miles, Ronald N.

    2012-01-01

    The paper applies the re-expansion method for analyzing planar discontinuities at the junction of two axi-symmetrical circular waveguides. The normal modes in the two waveguides are expanded at the junction plane into a system of functions accounting for velocity singularities at the corner points. As the new expansion has a high convergence order, only a few terms have to be considered for obtaining the solution of most practical problems. This paper gives the equivalent impedance accounting for nonplanar waves into a plane-wave analysis and also the scattering matrix describing the coupling of arbitrary modes at each side of the discontinuity valid in the case of many propagating modes in both sides of the duct. The last section applies the re-expansion technique to some concentric expansion chambers providing an explicit formula for the transmission loss coefficient. PMID:22352491

  19. Solubilization of rehydrated frozen highly concentrated micellar casein for use in liquid food applications.

    PubMed

    Lu, Y; McMahon, D J; Metzger, L E; Kommineni, A; Vollmer, A H

    2015-09-01

    Highly concentrated micellar casein concentrate (HC-MCC), a potential ingredient of protein-fortified food, is a gel at cold temperature. It contains ~17 to 21% casein, with most serum proteins and lactose removed by microfiltration and diafiltration, and it is then further concentrated using vacuum evaporation. The HC-MCC can be stored frozen, and our objective was to determine the conditions needed to obtain complete solubility of thawed HC-MCC in water and to understand its gelation upon cooling. Dispersibility (ability to pass through a 250-µm mesh sieve), suspendability (percentage of protein not sedimented at 80 × g within 5min), and solubility (percentage of protein not sedimented at 20,000 × g within 5min) were measured at 4, 12, or 20°C after various mixing conditions. Gelation upon cooling from 50 to 5°C was monitored based on storage (G') and loss (G'') moduli. The gelled HC-MCC was also examined by transmission electron microscopy. Thawed HC-MCC was added to water to reach a protein concentration of 3% and mixed using high shear (7,500rpm) for 1min or low shear (800rpm) for 30min at 4, 12, 20, or 50°C and at pH 6.4 to 7.2. The HC-MCC completely dispersed at 50°C, or at ≤20°C followed by overnight storage at 4°C. Suspendability at 50°C was ~90% whereas mixing at ≤20°C followed by overnight storage resulted in only ~57% suspendability. Solubility followed a similar trend with ~83% at 50°C and only ~29% at ≤20°C. Mixing HC-MCC with 60mM trisodium citrate increased dispersibility to 99% and suspendability and solubility to 81% at 20°C. Cold-gelling temperature, defined as the temperature at which G'=G'' when cooling from 50 to 5°C, was positively correlated with protein level in HC-MCC. Gelation occurred at 38, 28, and 7°C with 23, 20, and 17% of protein, respectively. Gelation was reversible upon heating, although after a second cooling cycle the HC-MCC gel had lower G'. In micrographs of gelled HC-MCC, the casein micelles were

  20. Fabrication of Monolithic Integrated Series-Connected GaAs Photovoltaic Cells for Concentrator Applications

    NASA Astrophysics Data System (ADS)

    Watanabe, Kentaroh; Yamada, Yugo; Senou, Minato; Sugiyama, Masakazu; Nakano, Yoshiaki

    2012-10-01

    Aiming at reducting in Joule energy loss of a photovoltaic cell under sunlight concentration, monolithic integration of GaAs cells has been realized, in which five subcells were connected in series and the total surface area of the cells occupied over 80% of the whole chip area. Using plasma etching with Cl2, a sufficiently sharp mesa for device isolation was obtained. Insulation between etched mesa sidewalls and interconnect electrodes proved to be the most significant issues for the purpose of eliminating shunt resistance and securing a reasonable fill factor; the SiO2 layer deposited by sputtering was much superior to polyimide as an insulator. The fabricated test device showed a short circuit current density of 20.7 mA/cm2 and an open circuit voltage of 4.79 V, which were consistent with the values for a single subcell.

  1. A composite application of source and receptor models to fine particle concentrations in Portage, Wisconsin

    SciTech Connect

    Chow, J.C.; Severance, P.W.; Spengler, J.D.

    1985-01-01

    The research reported here extends source apportioment techniques by combining four air quality model types to establish multi-scale source/receptor relationships. The selected models are: Branching Atmospheric Trajectory (BAT) model for regional-scale contributors; Principal Component Analysis (PCA) receptor model for urban and regional-scale contributors; Chemical Mass Balance (CMB) receptor model for urban- and regional-scale contributors; Industrial Source Complex Short-Term (ISC-ST) dispersion model for urban-scale contributors. The framework in which these models are placed allows each one to be replaced with better ones when these new models have been demonstrated to be superior. The theoretical basis, previous applications, and the results of model evaluation studies are summarized by Chow in great detail and will not be presented here. The objectives of this research are: to develop a method for multi-scale composite modeling applications; to define the data requirements; and to apportion local and distract pollution sources using the composite modeling strategy. Results from the entire research effort are too lengthy to include here. This paper focuses on CMB portion of the method. Trajectory and Principal Component Analyses were reported earlier.

  2. Usefulness of nano-zirconia for purification and concentration of ¹²⁵I solution for medical applications.

    PubMed

    Ram, Ramu; Chakravarty, Rubel; Dash, Ashutosh

    2013-12-01

    This paper described the utility of tetragonal nano-zirconia (t-ZrO₂) to remove trace levels of ¹³⁴Cs and ¹³⁷Cs contaminants from ¹²⁵I solution obtained from neutron irradiation of natural Xe target. A careful scrutiny of the adsorption parameters of t-ZrO₂ was considered worthwhile investigating to arrive at the optimum conditions to perform the purification as well as concentration of ¹²⁵I solution. The procedure proposed herein provides ¹²⁵I of acceptable purity and radioactive concentration for clinical application. The compatibility of the separated product in the preparation of ¹²⁵I brachytherapy sources was found to be satisfactory. PMID:24184738

  3. In vitro trans-scleral iontophoresis of methylprednisolone hemisuccinate with short application time and high drug concentration.

    PubMed

    Pescina, S; Martini, D; Santi, P; Padula, C; Murtomäki, L; Nicoli, S

    2013-07-15

    Trans-scleral iontophoresis, i.e. the application of small electric current to enhance drug transport across sclera is an option for non-invasive delivery of corticosteroids to the posterior segment of the eye. In this paper, in vitro trans-scleral iontophoresis of methylprednisolone hemisuccinate was investigated using concentrated drug solutions and short application times to mimic the iontophoretic conditions of in vivo studies. The drug at the donor concentration of 45 mg/ml was delivered through isolated porcine sclera under passive and iontophoretic conditions (cathodal, 2.4 mA) for 2-15 min. In a second set of experiments, the drug was delivered for 5 min at current intensities of 0.9-7.2 mA. After donor removal, drug release was followed up to 24 h. The exposure of concentrated solutions to sclera for 2-15 min under passive conditions caused a notable accumulation of drug up to 0.8 mg/cm², the release of which was successively followed for 24 h. In cathodal iontophoresis, the amount of accumulated drug increased proportionally to the charge between 0.3 and 1.44 Coulomb. When the charge was increased to 2.16 Coulomb by increasing the application time or current intensity, no further enhancement was recorded. This behaviour can be ascribed to substantial drug adsorption on the scleral tissue, as demonstrated through streaming potential studies, with the consequent increase of the electroosmotic flow that opposes drug transport. The set up suggested here could help in defining the optimal conditions for in vivo studies with animal models and reducing the number of in vivo experiments. PMID:23628405

  4. Concentrating anthropogenic disturbance to balance ecological and economic values: applications to forest management.

    PubMed

    Tittler, Rebecca; Messier, Christian; Fall, Andrew

    2012-06-01

    To maintain healthy ecosystems, natural-disturbance-based management aims to minimize differences between unmanaged and managed landscapes. Two related approaches may help accomplish this goal, either applied together or in isolation: (1) concentrating anthropogenic disturbance through zoning (with protected areas and intensive management); and (2) emulating natural disturbances. The purpose of this paper is to examine the effects of these two approaches, applied both in isolation and in combination, on the structure of the forest landscape. To do so, we use a spatially explicit landscape simulation model on a large fire-dominated landscape in eastern Canada. Specifically, we examine the effects of (1) increasing the maximum size of logged stands (cutblocks) to better emulate the full range of fire sizes in a fire-dominated landscape, (2) increasing protected areas, and (3) adding aggregated or dispersed intensive wood production areas to the landscape in addition to protected areas (triad management). We focus on maximizing the amount and minimizing the fragmentation of old-growth forest and on reducing road construction. Increasing maximum cutblock size and adding protected areas led to reduced road construction, while the latter also resulted in less fragmentation and more old growth. Although protected areas led to reduced harvest volume, the addition of an intensive production zone (triad management) counterbalanced this loss and resulted in more old growth than equivalent scenarios with protected areas but no intensive production zone. However, we found no differences between aggregated and dispersed intensive wood production. Our results imply that differences between unmanaged and managed landscapes can be reduced by concentrating logging efforts through a combination of protected areas and intensive wood production, and by creating some larger cutblocks. We conclude that the forest industry and regulators should therefore seek to increase protected areas

  5. Development and Application of Regression Models for Estimating Nutrient Concentrations in Streams of the Conterminous United States, 1992-2001

    USGS Publications Warehouse

    Spahr, Norman E.; Mueller, David K.; Wolock, David M.; Hitt, Kerie J.; Gronberg, JoAnn M.

    2010-01-01

    Data collected for the U.S. Geological Survey National Water-Quality Assessment program from 1992-2001 were used to investigate the relations between nutrient concentrations and nutrient sources, hydrology, and basin characteristics. Regression models were developed to estimate annual flow-weighted concentrations of total nitrogen and total phosphorus using explanatory variables derived from currently available national ancillary data. Different total-nitrogen regression models were used for agricultural (25 percent or more of basin area classified as agricultural land use) and nonagricultural basins. Atmospheric, fertilizer, and manure inputs of nitrogen, percent sand in soil, subsurface drainage, overland flow, mean annual precipitation, and percent undeveloped area were significant variables in the agricultural basin total nitrogen model. Significant explanatory variables in the nonagricultural total nitrogen model were total nonpoint-source nitrogen input (sum of nitrogen from manure, fertilizer, and atmospheric deposition), population density, mean annual runoff, and percent base flow. The concentrations of nutrients derived from regression (CONDOR) models were applied to drainage basins associated with the U.S. Environmental Protection Agency (USEPA) River Reach File (RF1) to predict flow-weighted mean annual total nitrogen concentrations for the conterminous United States. The majority of stream miles in the Nation have predicted concentrations less than 5 milligrams per liter. Concentrations greater than 5 milligrams per liter were predicted for a broad area extending from Ohio to eastern Nebraska, areas spatially associated with greater application of fertilizer and manure. Probabilities that mean annual total-nitrogen concentrations exceed the USEPA regional nutrient criteria were determined by incorporating model prediction uncertainty. In all nutrient regions where criteria have been established, there is at least a 50 percent probability of exceeding

  6. Performance measurements of new silicon carbide coated reflectors for concentrated solar power applications

    NASA Astrophysics Data System (ADS)

    Belasri, Djawed; Nakamura, Kazuki; Armstrong, Peter; Calvet, Nicolas

    2016-05-01

    The new silicon carbide coated mirrors (SiC-mirrors) developed by Ibiden Co., Ltd. and tested at the Masdar Institute of Science and Technology offer several advantages in concentrated solar power (CSP) structure and operation. The purpose of this paper is to present the results of the reflectance and durability of the SiC-mirrors compared to high quality CSP glass mirrors in conjunction with two different applied cleaning methods. SiC-mirrors are 40 % lighter than high quality CSP glass mirrors, which leads to reduce costs of heliostat, parabolic trough or linear Fresnel structures, including assembly and installation time, lower drive power requirements, and stress during tracking operation. Lab and field tests show the SiC mirrors' reflectance is as high as the high quality CSP glass mirrors. Indeed, after 32 weeks of exposure, the high quality CSP glass mirrors' reflectance has decreased by 19 %, while the SiC mirrors' reflectance has decreased by 20 % when the brushing with water cleaning was applied. Using the brushing without water cleaning, the reflectance has decreased by 13 % and 2 % for the high quality CSP glass mirrors and the SiC-mirrors, respectively.

  7. Clinical Applications of 4-Factor Prothrombin Complex Concentrate: A Practical Pathologist's Perspective.

    PubMed

    Unold, David; Tormey, Christopher A

    2015-12-01

    A 4-factor prothrombin complex concentrate (4F-PCC), containing therapeutic doses of vitamin K-dependent coagulation factors, was recently licensed in the United States for reversal of vitamin K antagonist therapy. However, given the emergence of several oral anticoagulants for which there are no specific reversal agents, and the existence of many other complex bleeding disorders, it is likely that clinicians will seek to use 4F-PCCs for any number of off-label indications. Thus, the goal of this review is to explore practical issues regarding 4F-PCC, with an emphasis on issues relevant to blood bankers and pathologists. Specifically, our aims are to (1) examine the role of 4F-PCC in vitamin K antagonist reversal, (2) review its potential use in the treatment of hemorrhage due to novel oral anticoagulants, and (3) explore potential uses in liver disease, trauma-associated bleeding, and rare coagulopathies. Safety and other practical considerations of 4F-PCCs will also be discussed. PMID:26619030

  8. Concentrating solar power (CSP) power cycle improvements through application of advanced materials

    NASA Astrophysics Data System (ADS)

    Siefert, John A.; Libby, Cara; Shingledecker, John

    2016-05-01

    Concentrating solar power (CSP) systems with thermal energy storage (TES) capability offer unique advantages to other renewable energy technologies in that solar radiation can be captured and stored for utilization when the sun is not shining. This makes the technology attractive as a dispatchable resource, and as such the Electric Power Research Institute (EPRI) has been engaged in research and development activities to understand and track the technology, identify key technical challenges, and enable improvements to meet future cost and performance targets to enable greater adoption of this carbon-free energy resource. EPRI is also involved with technically leading a consortium of manufacturers, government labs, and research organizations to enable the next generation of fossil fired power plants with advanced ultrasupercritical (A-USC) steam temperatures up to 760°C (1400°F). Materials are a key enabling technology for both of these seemingly opposed systems. This paper discusses how major strides in structural materials for A-USC fossil fired power plants may be translated into improved CSP systems which meet target requirements.

  9. High-sensitivity in situ QCLAS-based ammonia concentration sensor for high-temperature applications

    NASA Astrophysics Data System (ADS)

    Peng, W. Y.; Sur, R.; Strand, C. L.; Spearrin, R. M.; Jeffries, J. B.; Hanson, R. K.

    2016-07-01

    A novel quantum cascade laser (QCL) absorption sensor is presented for high-sensitivity in situ measurements of ammonia (hbox {NH}_3) in high-temperature environments, using scanned wavelength modulation spectroscopy (WMS) with first-harmonic-normalized second-harmonic detection (scanned WMS-2 f/1 f) to neutralize the effect of non-absorption losses in the harsh environment. The sensor utilized the sQ(9,9) transition of the fundamental symmetric stretch band of hbox {NH}_3 at 10.39 {\\upmu }hbox {m} and was sinusoidally modulated at 10 kHz and scanned across the peak of the absorption feature at 50 Hz, leading to a detection bandwidth of 100 Hz. A novel technique was used to select an optimal WMS modulation depth parameter that reduced the sensor's sensitivity to spectral interference from hbox {H}_2hbox {O} and hbox {CO}_2 without significantly sacrificing signal-to-noise ratio. The sensor performance was validated by measuring known concentrations of hbox {NH}_3 in a flowing gas cell. The sensor was then demonstrated in a laboratory-scale methane-air burner seeded with hbox {NH}_3, achieving a demonstrated detection limit of 2.8 ± 0.26 ppm hbox {NH}_3 by mole at a path length of 179 cm, equivalence ratio of 0.6, pressure of 1 atm, and temperatures of up to 600 K.

  10. Active and Passive Microwave Retrieval Algorithm for Hydrometeor Concentration Profiles: Application to the HAMP Instrument

    NASA Astrophysics Data System (ADS)

    Orlandi, E.; Mech, M.; Crewell, S.; Lammert, A.

    2012-12-01

    Clouds and precipitation play an important role in the atmospheric water cycle and radiation budget. Unfortunately, the understanding of the processes involved in cloud and precipitation formation and their description in global and regional models are still poor. To improve our understanding of these processes and to reduce model uncertainties, new observation and retrieval techniques are needed. The upcoming Global Precipitation Mission (GPM) provides a combination of a 36 GHz cloud radar and a suite of passive microwave instruments. In the retrieval development process for this and other upcoming missions, airborne platforms are a useful tool to test the algorithms exploiting the synergy of active and passive microwave instruments, and to validate satellite retrievals. In this respect HAMP (Microwave Package for HALO, the High Altitude Long Range aircraft), consisting of a 36 GHz Doppler cloud radar and a 26-channel radiometer, is an ideal test-bed. HAMP radiometers have frequencies along absorption lines (22, 60, 118 and 183 GHz) and in window regions, overlapping with those of AMSU A and B. HAMP will participate in early 2013 in the dedicated remote sensing HALO mission NARVAL (Next-generation Aircraft Remote-sensing for VALidation studies). During NARVAL, the HALO payload will include a water vapor lidar and drop sondes in addition to HAMP. The NARVAL campaign will thus be a excellent opportunity to test a newly developed retrieval algorithm, which exploits the synergy between passive and active microwave observations. In this work we present a Bayesian algorithm to retrieve precipitation rate, liquid and frozen hydrometeor concentration, as well as temperature and humidity profiles from the synergetic use of active and passive microwave nadir observations. Temperature and humidity are derived solely from passive radiometer measurements while the combined cloud radar and radiometer observations are used to retrieve hydrometeor concentration profiles. Lidar

  11. On Using Model Populations to Determine Mechanical Properties of Skeletal Muscle. Application to Concentric Contraction Simulation.

    PubMed

    Sierra, M; Miana-Mena, F J; Calvo, B; Muñoz, M J; Rodríguez, J F; Grasa, J

    2015-10-01

    In the field of computational biomechanics, the experimental evaluation of the material properties is crucial for the development of computational models that closely reproduce real organ systems. When simulations of muscle tissue are concerned, stress/strain relations for both passive and active behavior are required. These experimental relations usually exhibit certain variability. In this study, a set of material parameters involved in a 3D skeletal muscle model are determined by using a system biology approach in which the parameters are randomly varied leading to a population of models. Using a set of experimental results from an animal model, a subset of the entire population of models was selected. This reduced population predicted the mechanical response within the window of experimental observations. Hence, a range of model parameters, instead of a single set of them, was determined. Rat Tibialis Anterior muscle was selected for this study. Muscles ([Formula: see text]) were activated through the sciatic nerve and during contraction the tissue pulled a weight fixed to the distal tendon (concentric contraction). Three different weights 1, 2 and 3 N were used and the time course of muscle stretch was analyzed obtaining values of (mean [Formula: see text] standard deviation): [Formula: see text], [Formula: see text] and [Formula: see text] respectively. A paired two-sided sign rank test showed significant differences between the muscle response for the three weights ([Formula: see text]). This study shows that the Monte Carlo method could be used for determine muscle characteristic parameters considering the variability of the experimental population. PMID:25691399

  12. Application of time-resolved glucose concentration photoacoustic signals based on an improved wavelet denoising

    NASA Astrophysics Data System (ADS)

    Ren, Zhong; Liu, Guodong; Huang, Zhen

    2014-10-01

    Real-time monitoring of blood glucose concentration (BGC) is a great important procedure in controlling diabetes mellitus and preventing the complication for diabetic patients. Noninvasive measurement of BGC has already become a research hotspot because it can overcome the physical and psychological harm. Photoacoustic spectroscopy is a well-established, hybrid and alternative technique used to determine the BGC. According to the theory of photoacoustic technique, the blood is irradiated by plused laser with nano-second repeation time and micro-joule power, the photoacoustic singals contained the information of BGC are generated due to the thermal-elastic mechanism, then the BGC level can be interpreted from photoacoustic signal via the data analysis. But in practice, the time-resolved photoacoustic signals of BGC are polluted by the varities of noises, e.g., the interference of background sounds and multi-component of blood. The quality of photoacoustic signal of BGC directly impacts the precision of BGC measurement. So, an improved wavelet denoising method was proposed to eliminate the noises contained in BGC photoacoustic signals. To overcome the shortcoming of traditional wavelet threshold denoising, an improved dual-threshold wavelet function was proposed in this paper. Simulation experimental results illustrated that the denoising result of this improved wavelet method was better than that of traditional soft and hard threshold function. To varify the feasibility of this improved function, the actual photoacoustic BGC signals were test, the test reslut demonstrated that the signal-to-noises ratio(SNR) of the improved function increases about 40-80%, and its root-mean-square error (RMSE) decreases about 38.7-52.8%.

  13. Reconstruction mechanisms of tantalum oxide coatings with low concentrations of silver for high temperature tribological applications

    SciTech Connect

    Stone, D. S.; Bischof, M.; Aouadi, S. M.; Gao, H.; Martini, A.; Chantharangsi, C.; Paksunchai, C.

    2014-11-10

    Silver tantalate (AgTaO{sub 3}) coatings have been found to exhibit outstanding tribological properties at elevated temperatures. To understand the mechanisms involved in the tribological behavior of the Ag-Ta-O system, tantalum oxide coatings with a small content of silver were produced to investigate the metastable nature of this self-lubricating material. The coatings were produced by unbalanced magnetron sputtering, ball-on-disk wear tested at 750 °C, and subsequently characterized by X-ray diffraction, Scanning Auger Nanoprobe, cross-sectional Scanning Electron Microscopy, and Transmission Electron Microscopy. Complementary molecular dynamic simulations were carried out to investigate changes in the chemical and structural properties at the interface due to sliding for films with varying silver content. Both the experimental characterization and the theoretical modeling showed that silver content affects friction and wear, through the role of silver in film reconstruction during sliding. The results suggest that the relative amount of silver may be used to tune film performance for a given application.

  14. Reconstruction mechanisms of tantalum oxide coatings with low concentrations of silver for high temperature tribological applications

    PubMed Central

    Stone, D. S.; Gao, H.; Chantharangsi, C.; Paksunchai, C.; Bischof, M.; Martini, A.; Aouadi, S. M.

    2014-01-01

    Silver tantalate (AgTaO3) coatings have been found to exhibit outstanding tribological properties at elevated temperatures. To understand the mechanisms involved in the tribological behavior of the Ag-Ta-O system, tantalum oxide coatings with a small content of silver were produced to investigate the metastable nature of this self-lubricating material. The coatings were produced by unbalanced magnetron sputtering, ball-on-disk wear tested at 750 °C, and subsequently characterized by X-ray diffraction, Scanning Auger Nanoprobe, cross-sectional Scanning Electron Microscopy, and Transmission Electron Microscopy. Complementary molecular dynamic simulations were carried out to investigate changes in the chemical and structural properties at the interface due to sliding for films with varying silver content. Both the experimental characterization and the theoretical modeling showed that silver content affects friction and wear, through the role of silver in film reconstruction during sliding. The results suggest that the relative amount of silver may be used to tune film performance for a given application. PMID:25425745

  15. Reconstruction mechanisms of tantalum oxide coatings with low concentrations of silver for high temperature tribological applications

    NASA Astrophysics Data System (ADS)

    Stone, D. S.; Gao, H.; Chantharangsi, C.; Paksunchai, C.; Bischof, M.; Martini, A.; Aouadi, S. M.

    2014-11-01

    Silver tantalate (AgTaO3) coatings have been found to exhibit outstanding tribological properties at elevated temperatures. To understand the mechanisms involved in the tribological behavior of the Ag-Ta-O system, tantalum oxide coatings with a small content of silver were produced to investigate the metastable nature of this self-lubricating material. The coatings were produced by unbalanced magnetron sputtering, ball-on-disk wear tested at 750 °C, and subsequently characterized by X-ray diffraction, Scanning Auger Nanoprobe, cross-sectional Scanning Electron Microscopy, and Transmission Electron Microscopy. Complementary molecular dynamic simulations were carried out to investigate changes in the chemical and structural properties at the interface due to sliding for films with varying silver content. Both the experimental characterization and the theoretical modeling showed that silver content affects friction and wear, through the role of silver in film reconstruction during sliding. The results suggest that the relative amount of silver may be used to tune film performance for a given application.

  16. Application of granular ferric hydroxides for removal elevated concentrations of arsenic from mine waters

    NASA Astrophysics Data System (ADS)

    Szlachta, Małgorzata; Włodarczyk, Paweł; Wójtowicz, Patryk

    2015-04-01

    Arsenic is naturally occurring element in the environment. Over three hundred minerals are known to contain some form of arsenic and among them arsenopyrite is the most common one. Arsenic-bearing minerals are frequently associated with ores containing mined metals such as copper, tin, nickel, lead, uranium, zinc, cobalt, platinum and gold. In the aquatic environment arsenic is typically present in inorganic forms, mainly in two oxidation states (+5, +3). As(III) is dominant in more reduced conditions, whereas As(V) is mostly present in an oxidizing environment. However, due to certain human activities the elevated arsenic levels in aquatic ecosystems are arising to a serious environmental problem. High arsenic concentrations found in surface and groundwaters, in some regions originate from mining activities and ore processing. Therefore, the major concern of mining industry is to maintain a good quality of effluents discharged in large volumes. This requires constant monitoring of effluents quality that guarantee the efficient protection of the receiving waters and reacting to possible negative impact of contamination on local communities. A number of proven technologies are available for arsenic removal from waters and wastewaters. In the presented work special attention is given to the adsorption method as a technically feasible, commonly applied and effective technique for the treatment of arsenic rich mine effluents. It is know that arsenic has a strong affinity towards iron rich materials. Thus, in this study the granular ferric hydroxides (CFH 12, provided by Kemira Oyj, Finland) was applied to remove As(III) and As(V) from aqueous solutions. The batch adsorption experiments were carried out to assess the efficiency of the tested Fe-based material under various operating parameters, including composition of treated water, solution pH and temperature. The results obtained from the fixed bed adsorption tests demonstrated the benefits of applying granular

  17. Application of the windowed-Fourier-transform-based fringe analysis technique for investigating temperature and concentration fields in fluids.

    PubMed

    Mohanan, Sharika; Srivastava, Atul

    2014-04-10

    The present work is concerned with the development and application of a novel fringe analysis technique based on the principles of the windowed-Fourier-transform (WFT) for the determination of temperature and concentration fields from interferometric images for a range of heat and mass transfer applications. Based on the extent of the noise level associated with the experimental data, the technique has been coupled with two different phase unwrapping methods: the Itoh algorithm and the quality guided phase unwrapping technique for phase extraction. In order to generate the experimental data, a range of experiments have been carried out which include cooling of a vertical flat plate in free convection conditions, combustion of mono-propellant flames, and growth of organic as well as inorganic crystals from their aqueous solutions. The flat plate and combustion experiments are modeled as heat transfer applications wherein the interest is to determine the whole-field temperature distribution. Aqueous-solution-based crystal growth experiments are performed to simulate the mass transfer phenomena and the interest is to determine the two-dimensional solute concentration field around the growing crystal. A Mach-Zehnder interferometer has been employed to record the path-integrated quantity of interest (temperature and/or concentration) in the form of interferometric images in the experiments. The potential of the WFT method has also been demonstrated on numerically simulated phase data for varying noise levels, and the accuracy in phase extraction have been quantified in terms of the root mean square errors. Three levels of noise, i.e., 0%, 10%, and 20% have been considered. Results of the present study show that the WFT technique allows an accurate extraction of phase values that can subsequently be converted into two-dimensional temperature and/or concentration distribution fields. Moreover, since WFT is a local processing technique, speckle patterns and the inherent

  18. Non-hazardous pesticide concentrations in surface waters: An integrated approach simulating application thresholds and resulting farm income effects.

    PubMed

    Bannwarth, M A; Grovermann, C; Schreinemachers, P; Ingwersen, J; Lamers, M; Berger, T; Streck, T

    2016-01-01

    Pesticide application rates are high and increasing in upland agricultural systems in Thailand producing vegetables, fruits and ornamental crops, leading to the pollution of stream water with pesticide residues. The objective of this study was to determine the maximum per hectare application rates of two widely used pesticides that would achieve non-hazardous pesticide concentrations in the stream water and to evaluate how farm household incomes would be affected if farmers complied with these restricted application rates. For this purpose we perform an integrated modeling approach of a hydrological solute transport model (the Soil and Water Assessment Tool, SWAT) and an agent-based farm decision model (Mathematical Programming-based Multi-Agent Systems, MPMAS). SWAT was used to simulate the pesticide fate and behavior. The model was calibrated to a 77 km(2) watershed in northern Thailand. The results show that to stay under a pre-defined eco-toxicological threshold, the current average application of chlorothalonil (0.80 kg/ha) and cypermethrin (0.53 kg/ha) would have to be reduced by 80% and 99%, respectively. The income effect of such reductions was simulated using MPMAS. The results suggest that if farm households complied with the application thresholds then their income would reduce by 17.3% in the case of chlorothalonil and by 38.3% in the case of cypermethrin. Less drastic income effects can be expected if methods of integrated pest management were more widely available. The novelty of this study is to combine two models from distinctive disciplines to evaluate pesticide reduction scenarios based on real-world data from a single study site. PMID:26431614

  19. A survey of airborne HDI, HDI-based polyisocyanate and solvent concentrations in the manufacture and application of polyurethane coatings.

    PubMed

    Myer, H E; O'Block, S T; Dharmarajan, V

    1993-11-01

    This study summarizes the results of industrial hygiene surveys performed between 1979 and 1987 in paint manufacturing and application operations using polyurethane coatings containing hexamethylene diisocyanate (HDI) and HDI-based polyisocyanates (trade name Desmodur N). A total of 466 Desmodur N and 457 HDI samples were collected from 47 operations most of which were in application. The application surveys covered manufacture and refinishing of transportation vehicles, painting of large military and civilian equipment, industrial finishing operations, and maintenance and construction operations. The primary objective of the surveys was to assess the potential exposure to HDI and HDI-based polyisocyanate. In more than 60% of the surveys, concentrations of airborne organic solvents also were monitored. Isocyanates were sampled using toluene/nitroreagent in midget impingers, and solvents were collected using charcoal tubes. They were analyzed using high pressure liquid chromatography and gas chromatography, respectively. The data from these workplace situations show there is some potential for isocyanate overexposure of unprotected workers and that it is greater in spray than in nonspray operations. PMID:8256690

  20. [Value of gentamycin concentration in aqueous humor of a rabbit's eye depending on the method of application. Summary of a doctoral thesis].

    PubMed

    Philips, R H

    1992-10-01

    Pharmacokinetics of gentamycin in the primary and secondary rabbit's aqueous was examined by using a new experimental method of subconjunctival application (without breaking the continuity of the conjunctiva). It was established that after subconjunctival application one cannot obtain any therapeutical concentrations in the primary or secondary aqueous. Presented are conditions which have to be fulfilled to obtain a therapeutical concentration of gentamycin in the secondary aqueous. PMID:1306533

  1. Thorium concentrations in the lunar surface. II - Deconvolution modeling and its application to the regions of Aristarchus and Mare Smythii

    NASA Technical Reports Server (NTRS)

    Haines, E. L.; Etchegaray-Ramirez, M. I.; Metzger, A. E.

    1978-01-01

    The broad angular response which characterized the Apollo gamma ray spectrometer resulted in a loss of spatial resolution and some of the contrast in determining surface concentrations within lunar regions small compared to the field of view. A deconvolution technique has been developed which removes much of this instrumental effect, thereby improving both spatial resolution and accuracy at the cost of a loss in precision. Geometric models of regional thorium distribution are convoluted through the response function of the instrument to yield a predicted distribution which is compared with the observed data field for quality of fit. Application to areas which include Aristarchus and Mare Smythii confirm some geological relationships and fail to support others.

  2. Screening Carbohydrate Libraries for Protein Interactions Using the Direct ESI-MS Assay. Applications to Libraries of Unknown Concentration

    NASA Astrophysics Data System (ADS)

    Kitova, Elena N.; El-Hawiet, Amr; Klassen, John S.

    2014-08-01

    A semiquantitative electrospray ionization mass spectrometry (ESI-MS) binding assay suitable for analyzing mixtures of oligosaccharides, at unknown concentrations, for interactions with target proteins is described. The assay relies on the differences in the ratio of the relative abundances of the ligand-bound and free protein ions measured by ESI-MS at two or more initial protein concentrations to distinguish low affinity (≤103 M-1) ligands from moderate and high affinity (>105 M-1) ligands present in the library and to rank their affinities. Control experiments were performed on solutions of a single chain antibody and a mixture of synthetic oligosaccharides, with known affinities, in the absence and presence of a 40-component carbohydrate library to demonstrate the implementation and reliability of the assay. The application of the assay for screening natural libraries of carbohydrates against proteins is also demonstrated using mixtures of human milk oligosaccharides, isolated from breast milk, and fragments of a bacterial toxin and human galectin 3.

  3. A Simple Technique of Liquid Purity Analysis and Its Application to Analysis of Water Concentration in Alcohol-Water Mixtures

    NASA Astrophysics Data System (ADS)

    de, Dilip; Aziz de, Abdul

    2012-10-01

    The change of activation energy of a liquid molecule and hence its viscosity coefficient with addition of contaminants to the original liquid gives rise to a new technology for analysis of purity of the liquid. We discovered that concentration of certain contaminants such as water in alcohol or vice versa can be uniquely and accurately determined in a short time (about 10-15 minutes) using a simple and yet innovative technique that only requires measurement of time of flow of the impure liquid (say, water-alcohol mixture) and distilled water through a simple viscometer. We determined the increase of activation energy of alcohol molecules with increase of water concentration for ethyl and methyl alcohol. Our detailed investigation on the alcohol-water mixtures along with discussion on possible future potential application of the simple and very reliable inexpensive technique for liquid purity analysis is presented. We compared our present method with other methods on the accuracies, problems and reliability of impurity analysis in liquids. We also discuss a part of the quantum theory of viscosity of liquid mixtures that is in the developmental stage.

  4. Estimation of significant solvent concentration ranges and its application to the enhancement of the accuracy of gradient predictions.

    PubMed

    Vivó-Truyols, G; Torres-Lapasió, J R; García-Alvarez-Coque, M C

    2004-11-19

    The solvent concentration range actually useful for gradient predictions is significantly narrower than the total range scanned in a gradient run. This range, called "solvent informative range" (SIR), if known with the highest accuracy, allows to predict gradient retention times (t(g) with minimal error. The small size of the SIR supports the application of the linear solvent strength theory (LSST). Furthermore, LSST allows a closed-form solution to the integral required to predict gradient retention times, which eliminates numerical integration, needed with other retention models. A methodology that calculates the SIR by applying error analysis, and uses it to improve the accuracy in the prediction of t(g) from isocratic experiments, is proposed. The importance of those mobile-phase compositions that do not contribute significantly to the prediction of t(g) is selectively attenuated within the prediction algorithm, relying the predictions more heavily on the SIR. As a result, t(g) was found to be predicted with similar accuracy using isocratic training data with regard to predictions based on gradient training data. The approach is useful for all situations where the chromatographer is able to provide predictions of retention at constant solvent concentration, and wish to predict the retention in gradient mode. PMID:15584220

  5. Inlay osteotome sinus floor elevation with concentrated growth factor application and simultaneous short implant placement in severely atrophic maxilla.

    PubMed

    Chen, Yonghui; Cai, Zhiyu; Zheng, Dingguo; Lin, Pei; Cai, Yahua; Hong, Shuxin; Lai, Yiwei; Wu, Dong

    2016-01-01

    Sinus floor elevation with simultaneous implant placement in severely atrophic maxilla is challenging. The aim of this retrospective study was to evaluate the short-term performance of modified osteotome sinus floor elevation (OSFE) with concentrated growth factor (CGF) application and concurrent placement of a short implant in cases with residual bone height (RBH) of 2-4 mm. Twenty-five short implants were installed in 16 patients with mean RBH of 3.23 mm using modified OSFE with CGFs from January 2012 to April 2014. Postoperatively, the implants were clinically evaluated, and vertical bone gain (VBG) was measured using cone beam computed tomography. The mean duration of follow-up was 19.88 months (12-32 months). All the implants were stable with an overall survival rate of 100%. The mean VBG immediately after surgery was 9.21 mm. Six months later, significant reduction of alveolar bone height (2.90 ± 0.22 mm) was found (P < 0.05). During the second 6-month period, further alveolar bone resorption (0.14 ± 0.11 mm) was noted but without significance (P > 0.05). Within the limits of this study, modified OSFE with CGF application and simultaneous short implant placement could yield predictable clinical results for severely atrophic maxilla with RBH of 2-4 mm. PMID:27250556

  6. Inlay osteotome sinus floor elevation with concentrated growth factor application and simultaneous short implant placement in severely atrophic maxilla

    PubMed Central

    Chen, Yonghui; Cai, Zhiyu; Zheng, Dingguo; Lin, Pei; Cai, Yahua; Hong, Shuxin; Lai, Yiwei; Wu, Dong

    2016-01-01

    Sinus floor elevation with simultaneous implant placement in severely atrophic maxilla is challenging. The aim of this retrospective study was to evaluate the short-term performance of modified osteotome sinus floor elevation (OSFE) with concentrated growth factor (CGF) application and concurrent placement of a short implant in cases with residual bone height (RBH) of 2–4 mm. Twenty-five short implants were installed in 16 patients with mean RBH of 3.23 mm using modified OSFE with CGFs from January 2012 to April 2014. Postoperatively, the implants were clinically evaluated, and vertical bone gain (VBG) was measured using cone beam computed tomography. The mean duration of follow-up was 19.88 months (12–32 months). All the implants were stable with an overall survival rate of 100%. The mean VBG immediately after surgery was 9.21 mm. Six months later, significant reduction of alveolar bone height (2.90 ± 0.22 mm) was found (P < 0.05). During the second 6-month period, further alveolar bone resorption (0.14 ± 0.11 mm) was noted but without significance (P > 0.05). Within the limits of this study, modified OSFE with CGF application and simultaneous short implant placement could yield predictable clinical results for severely atrophic maxilla with RBH of 2–4 mm. PMID:27250556

  7. Comparison of the concentration-effect relationship of a local antiinflammatory agent and oral acetylsalicylic acid: the value of local application.

    PubMed

    Poisson, M; Ralambosoa, C; Blehaut, H; Astoin, J

    1985-01-01

    Using a pharmacological model, the comparison between acetylsalicylic acid (ASA), administered orally, and a solution combining two salicylate derivatives (ethyl 5-methoxy-salicylate and 3-phenyl-propyl-salicylate), applied locally, demonstrated the value of the local application. Indeed, the pharmacological activity was highly significant and directly related to the tissue concentration of salicyl ions, which was higher after local application of the solution than after oral administration of ASA. The local solution also resulted in a lower plasma concentration of salicylate ions, allowing high plasma salicylate concentrations to be avoided. PMID:4074414

  8. Effect of soil and foliar application of zinc on grain zinc and cadmium concentration of wheat genotypes differing in Zn-efficiency

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A two-year field experiment was carried out to investigate the effectiveness of soil and foliar applications of zinc sulfate and soil application of waste rubber ash to increase Zn and decrease cadmium (Cd) concentration in grain of 10 wheat genotypes with different Zn-efficiency. Foliar spray of zi...

  9. 40 CFR Table I-10 to Subpart I of... - Maximum Field Detection Limits Applicable to Fluorinated GHG Concentration Measurements for Stack...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Maximum Field Detection Limits Applicable to Fluorinated GHG Concentration Measurements for Stack Systems I Table I-10 to Subpart I of Part... Subpart I of Part 98—Maximum Field Detection Limits Applicable to Fluorinated GHG...

  10. Characterization and application of optical fibers: 1. Application of optical fibers in gas concentration and radiation dose measurements. 2. Polarization effects in fiber communication systems

    NASA Astrophysics Data System (ADS)

    Lu, Ping

    The thesis consists of two research directions: Optical fiber applications in gas concentration and radiation dose measurements; and polarization effects in fiber optic communication systems. Part I of the thesis presents two optical fiber applications. (1) An infrared (IR) fiber bundle has been designed and fabricated to measure gas concentrations in a chemical vapor deposition (CVD) chamber using Fourier transform infrared spectroscopy. This fiber bundle covers the IR range from 0.5 to 20 mum and reduces the light beam divergence in the CVD chamber, which makes it possible to measure gas concentrations in a region near the substrate surface. Semi-ellipsoid mirrors have been designed and used to increase the collection efficiency of infrared radiation and to compensate the loss introduced by the fiber bundle. (2) A fiber optic radiation sensor based on radiation-induced fiber loss is reported. The gamma radiation-induced loss spectra in various fibers have been studied. Among all the fibers tested, 5% P-doped fiber shows the highest sensitivity to gamma radiation. The wavelength and dose rate dependence of radiation-induced loss in 5% P-doped fiber are investigated and the possibility of using this fiber as a radiation sensor for radiation therapy is discussed. Part II of the thesis examines two polarization effects, polarization mode dispersion (PMD) and polarization dependent loss (PDL), in fiber optic communication systems based on the waveplate models. A new waveplate model, capable of generating any PMD and PDL values, is proposed to overcome the limitations of the conventional waveplate model. Using both models the statistical distributions of PDL and differential group delay (DGD) have been studied considering the presence of biased elliptical birefringence. The principal state of polarization (PSP) of an optical pulse is proposed for a fiber having both PMD and PDL. PMD and PDL of a pulse for a fiber consisting of two polarization maintaining fiber

  11. Concentration of Cu, Zn, Cr, Ni, Cd, and Pb in soil, sugarcane leaf and juice: residual effect of sewage sludge and organic compost application.

    PubMed

    Moretti, Sarah Mello Leite; Bertoncini, Edna Ivani; Vitti, André César; Alleoni, Luís Reynaldo Ferracciú; Abreu-Junior, Cassio Hamilton

    2016-03-01

    Many researchers have evaluated the effects of successive applications of sewage sludge (SS) on soil plant-systems, but most have not taken into account the residual effect of organic matter remaining from prior applications. Furthermore, few studies have been carried out to compare the effects of the agricultural use of SS and sewage sludge compost (SSC). Therefore, we evaluated the residual effect of SS and SSC on the heavy metal concentrations in soil and in sugarcane (Saccharum spp.) leaves and juice. The field experiment was established after the second harvesting of unburned sugarcane, when the organic materials were applied. The SS and SSC rates were (t ha(-1), dry base): 0, 12.5, 25, and 50; and 0, 21, 42, and 84, respectively. All element concentrations in the soil were below the standards established by São Paulo State environmental legislation. SS promoted small increases in Zn concentrations in soil and Cu concentrations in leaves. However, all heavy metals concentrations in the leaves were lower than the limits established for toxic elements and were in accordance with the limits established for micronutrients. There were reductions in the concentrations of Ni and Cu in soil and the concentration of Pb in juice, with increasing rates of SSC. The heavy metal concentrations were very low in the juice. Under humid tropical conditions and with short-term use, SS and SSC containing low heavy metal concentrations did not have negative effects on plants and soil. PMID:26879984

  12. Nitrification and N2O production processes in soil incubations after ammonium fertilizer application at high concentrations

    NASA Astrophysics Data System (ADS)

    Deppe, Marianna; Well, Reinhard; Giesemann, Anette; Flessa, Heinz

    2016-04-01

    High concentrations of ammonium as they occur, e.g., after point-injection of ammonium fertilizer solution according to the CULTAN fertilization technique may retard nitrification. Potential advantages in comparison to conventional fertilization include a higher N efficiency of crops, reduced nitrate leaching, and lower N2O and N2 emissions. Dynamics of nitrification due to plant uptake and dilution processes, leading to decreasing ammonium concentrations in fertilizer depots, has only poorly been studied before. Furthermore, there is little information about the relative contribution of different N2O production processes under these conditions. To elucidate the process dynamics a laboratory incubation study was conducted. After fertilization with ammonium sulfate at 5 levels (from 0 to 5000 mg NH4+-N kg‑1; 20mg NO3‑-N kg‑1 each), sandy loam soil was incubated in dynamic soil microcosms for 21 days. N2O, CH4 and CO2 fluxes as well as isotope signatures of N2O and, at three dates, NO3‑ and NH4+ were measured. To identify N2O production processes, acetylene inhibition (0.01 vol.%), 15N tracer approaches, and isotopomer data (15N site preference and δ18O) were used. N2O emissions were highest at 450mg NH4+-N kg‑1 and declined with further increasing concentrations. At 5000 mg NH4+-N kg‑1 nitrification was completely inhibited. However, approximately 90% of N2O production was inhibited by acetylene application, and there was no change in the relative contribution of nitrification and denitrification to N2O production with N level. Applying the non-equilibrium technique to our 15N tracer data revealed heterogeneous distribution of denitrification in soil, with at least two distinct NO3‑ pools, and spatial separation of NO3‑ formation and consumption. In comparison with the acetylene inhibition and 15N tracer approaches the results of the isotopomer approach were reasonable and indicated substantial contribution of nitrifier-denitrification (10-40%) to

  13. Application of ultradisperse magnetic adsorbents for removal of small concentrations of pollutants from large volumes of water

    NASA Astrophysics Data System (ADS)

    Nechitailo, Galina S.; Kuznetsov, Anatoli; Kuznetsov, Oleg

    2016-07-01

    with the adsorbed toluidine blue were removed from the solution by magnetic separation. The sorbent was proven to have high sorption capacity and rapid adsorption kinetics for toluidine blue. These experiments demonstrated the validity of the method, where a small concentration of a pollutant was successfully collected from a large volume of water. By varying the ratio of the sorbent/pollutant, it is possible to optimize the sorbent use and the time required to adsorb all pollutant present in the treated water. A variety of magnetically controlled sorbents can be designed and used in this method, from broad-spectrum adsorbing sorbents to sorbents specifically targeting a particular pollutant. These sorbents can be used either individually or as mixtures of sorbents with different properties, depending on the desired purification goals. Simplicity and scalability of this method allow a variety of ecological applications, as well as industrial ones, from process water purification to wastewater treatment.

  14. A long-wavelength quantum dot-concentric FRET configuration: characterization and application in a multiplexed hybridization assay.

    PubMed

    Li, Jia Jun; Algar, W Russ

    2016-06-21

    Quantum dot-based concentric Förster resonance energy transfer (cFRET) is a promising modality for the development of multifunctional fluorescent probes for bioanalysis and bioimaging. To date, the scope of cFRET has been largely limited to a prototypical configuration with a particular combination of quantum dot (QD) and fluorescent dyes linked through peptides. Expansion of the scope of cFRET is critical for its further development. Here, we expand the scope of cFRET in two capacities. First, we design and characterize a new long-wavelength cFRET configuration that combines red- and deep-red fluorescent dyes, Alexa Fluor 633 and Alexa Fluor 680, with an orange-emitting QD. Sequential and competitive energy transfer pathways are characterized through a rate analysis, where the balance of these rates more strongly favours competitive energy transfer in the new long-wavelength configuration versus sequential energy transfer in the previous prototypical configuration. Although the new cFRET configuration is more susceptible to photobleaching, its superior brightness and longer-wavelength excitation and emission provide an order of magnitude higher signal-to-background ratios in biological matrices (e.g., serum, blood) than the previous prototypical configuration. Second, we demonstrate that an oligonucleotide-linked, long-wavelength cFRET configuration has energy transfer similar to an analogous peptide-linked configuration, where the oligonucleotide-linked cFRET configuration can be combined with toehold-mediated strand displacement for the multiplexed detection of unlabeled nucleic acid targets as a single vector. Overall, this work establishes the general applicability of cFRET and introduces new strategies for its bioanalytical application. PMID:27048838

  15. Application of visible/near-infrared reflectance spectroscopy to uranium ore concentrates for nuclear forensic analysis and attribution.

    PubMed

    Klunder, Gregory L; Plaue, Jonathan W; Spackman, Paul E; Grant, Patrick M; Lindvall, Rachel E; Hutcheon, Ian D

    2013-09-01

    Uranium ore concentrates (UOCs) are produced at mining facilities from the various types of uranium-bearing ores using several processes that can include different reagents, separation procedures, and drying conditions. The final UOC products can consist of different uranium species, which are important to identify to trace interdicted samples back to their origins. Color has been used as a simple indicator; however, visual determination is subjective and no chemical information is provided. In this work, we report the application of near-infrared (NIR) spectroscopy as a non-contact, non-destructive method to rapidly analyze UOC materials for species and/or process information. Diffuse reflectance spectra from 350 to 2500 nm were measured from a number UOC samples that were also characterized by X-ray diffraction. Combination and overtone bands were used to identify the amine and hydroxyl-containing species, such as ammonium uranates or ammonium uranyl carbonate, while other uranium oxide species (e.g., uranium trioxide [UO3] and triuranium octoxide [U3O8]) exhibit absorption bands arising from crystal field effects and electronic transitions. Principal component analysis was used to classify the different UOC materials. PMID:24067636

  16. Influence of intraventricular application of baclofen on arterial blood pressure and neurotransmitter concentrations in the hypothalamic paraventricular nucleus of rats.

    PubMed

    Czell, David; Efe, Turgay; Preuss, Matthias; Schofer, Markus D; Becker, Ralf

    2012-02-01

    The hypothalamic paraventricular nucleus (PVN) is a key site for regulating neuroendocrine functions in the magnocellular part and autonomic activities in the parvocellular part. Its anatomical proximity to the third ventricle could be a good target for intrathecal injection of baclofen. We investigated the correlation of intrathecal application of baclofen (a specific GABAB receptor agonist) and the release of epinephrine, norepinephrine, dopac, homovanillinic acid (HVA), glutamate and aspartate from the PVN. The decomposition products HVA, dopa and dopac of norepinephrine, epinephrine and dopamine, respectively, were used as parameters for the secretion of dopamine. We implanted a microdialysis probe in the PVN of 25 Wistar rats. In 13 rats, 1.5 μg baclofen was injected in the lateral ventricle and the equivalent quantity of Ringer's lactate solution injected in the remaining 12 rats as a control group. Neurotransmitters and amino acids were quantified by high-performance liquid chromatography. There was a conspicuous but not significant effect of baclofen concerning the secretion of epinephrine, norepinephrine, dopac, glutamate and aspartate from the PVN. A significant increase in HVA concentration was observed only in rats treated with baclofen compared with the control group. These findings suggest that baclofen influences the secretion of neurotransmitters and amino acids involved in autonomic activities mediated by GABAB receptors. PMID:21984200

  17. Hyperspectral imaging system for imaging O2Hb and HHb concentration changes in tissue for various clinical applications

    NASA Astrophysics Data System (ADS)

    Klaessens, John H. G. M.; de Roode, Rowland; Verdaasdonk, Rudolf M.; Noordmans, Herke J.

    2011-03-01

    To observe local variations in temperature, oxygenation and blood perfusion over time, four imaging systems were developed and compared: Two systems consisting of white broadband light source and a CCD camera in combination with a Liquid Crystal Tunable Filter, one in the visual domain, 420-730 nm, and one in the infrared domain, 650-1100 nm. Thirdly, a CCD camera in combination with a software controlled hyper-spectral light source consisting of a panel with 600 LEDs divided in 17 spectral groups in the range from 370 to 880 nm so that specific spectral distributions can be generated at high repetition rate (>1000 Hz) and, fourthly a standard IR thermal camera for comparison. From the acquired images at the selected wavelengths chromophores concentration images of oxy and deoxy hemoglobin can be calculated applying different algorithms. These imaging techniques were applied and compared for various clinical applications: Tumor demarcation, early inflammation, effectiveness of peripheral nerve block anesthesia, and localization of epileptic seizure. The relative changes in oxygenation and temperature could be clearly observed in good correlation with the physiological condition. The algorithms and data collection/processing can be optimized to enable a real-time diagnostic technique.

  18. Data Concentrator

    NASA Technical Reports Server (NTRS)

    Willett, Mike

    2015-01-01

    Orbital Research, Inc., developed, built, and tested three high-temperature components for use in the design of a data concentrator module in distributed turbine engine control. The concentrator receives analog and digital signals related to turbine engine control and communicates with a full authority digital engine control (FADEC) or high-level command processor. This data concentrator follows the Distributed Engine Controls Working Group (DECWG) roadmap for turbine engine distributed controls communication development that operates at temperatures at least up to 225 C. In Phase I, Orbital Research developed detailed specifications for each component needed for the system and defined the total system specifications. This entailed a combination of system design, compiling existing component specifications, laboratory testing, and simulation. The results showed the feasibility of the data concentrator. Phase II of this project focused on three key objectives. The first objective was to update the data concentrator design modifications from DECWG and prime contractors. Secondly, the project defined requirements for the three new high-temperature, application-specific integrated circuits (ASICs): one-time programmable (OTP), transient voltage suppression (TVS), and 3.3V. Finally, the project validated each design by testing over temperature and under load.

  19. Autologous bone marrow concentrate: review and application of a novel intra-articular orthobiologic for cartilage disease.

    PubMed

    Sampson, Steven; Botto-van Bemden, Angie; Aufiero, Danielle

    2013-09-01

    Younger adults, aged < 65 years, increasingly present to their physicians with advanced cartilage disease or post-traumatic osteoarthritis. A number of treatments exist for lessening patient pain and improving patient function. However, many patients are becoming aware of the potential of regenerative therapies and are now seeking solutions to the impaired biology underlying their conditions rather than addressing only their symptoms. Patients do not want to merely lessen their symptoms temporarily with a surgical procedure that replaces damaged tissue, but instead seek correction and repair of the underlying biology to regenerate damaged tissue and alleviate their symptoms altogether. Current therapies for patients with cartilage disease or osteoarthritis range from non-surgical intra-articular injections with biologics, such as hyaluronic acid (HA), to total joint arthroplasty for advanced stages of disease. Total joint arthroplasty is a successful procedure for patients aged > 65 years; however, the limited long-term durability of implanted prostheses decreases the preference of using such methods in more active patients aged < 65 years. The potential of cell-based orthobiologic injection therapies (pertaining to therapeutic injectables that aim to restore the biologic environment and/or structural components of diseased or damaged musculoskeletal tissue) is of tremendous interest for younger, more active patients, and is even more appealing in that such therapy can be delivered at point-of-care in the clinic during an office visit. Notably, the exponential rate of progress in biotechnology has allowed for immediate application of myriad novel therapies prior to clear evidence of benefit from randomized clinical trials. Orthobiologic intra-articular injection therapies include HA and platelet-rich plasma (PRP). We report on current, available findings for a third-generation intra-articular orthobiologic injectable therapy for cartilage disease, bone marrow

  20. Increased RO concentrate toxicity following application of antiscalants - acute toxicity tests with the amphipods Gammarus pulex and Gammarus roeseli.

    PubMed

    Feiner, Mona; Beggel, Sebastian; Jaeger, Nadine; Geist, Juergen

    2015-02-01

    In reverse osmosis, a frequently used technology in water desalination processes, wastewater (RO concentrate) is generated containing the retained solutes as well as so-called antiscalants (AS), i.e. chemical substances that are commonly applied to prevent membrane-blocking. In this study, a risk assessment of a possible discharge of concentrate into a small stream was conducted. The acute toxicity of two concentrates containing two different ASs and of concentrate without AS to the amphipods Gammarus pulex and Gammarus roeseli was studied. Mortality of gammarids exposed to the concentrate without AS was not different to the control, whereas concentrates including ASs caused mortality rates up to 100% at the highest test concentrations after 168 h. Resulting EC50-values were 36.2-39.4% (v/v) after 96 h and 26.6-58.0% (v/v) after 168 h. These results suggest that the ecotoxicological relevance of antiscalants is greater than currently assumed. PMID:25476491

  1. Concentrations of synthetic musk compounds in personal care and sanitation products and human exposure profiles through dermal application.

    PubMed

    Roosens, Laurence; Covaci, Adrian; Neels, Hugo

    2007-11-01

    Synthetic musks, such as 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN) and 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-gamma-2-benzopyran (HHCB), musk ketone (MK) and musk xylene (MX), are used as an alternative for natural musk. Due to their widespread use, these synthetic compounds turned up in different environmental compartments, such as wastewater, human and animal tissues. Yet, little is known about their distribution and occurrence in personal care and household products, information needed in order to evaluate the different human exposure routes. This paper gives an overview of the synthetic musk levels in six different product categories: body lotions, perfumes, deodorants, hair care products, shower products and sanitation products. Especially body lotions, perfumes and deodorants contained high levels of synthetic musks. Maximum concentrations of HHCB, AHTN, MX and MK were 22 mg g(-1), 8 mg g(-1), 26 microg g(-1) and 0.5 microg g(-1), respectively. By combining these results with the average usage of consumer products, low-, medium- and high-exposure profiles through dermal application could be estimated. HHCB was the highest contributor to the total amount of synthetic musks in every exposure profile (18-23 700 microg d(-1)). Exposure to MK and MX did not increase substantially (10-20-fold) between low- and high-exposure profiles, indicating that these compounds cover a less broad range. In comparison, exposure to HHCB and AHTN increased up to 10 000 fold between low- and high-exposure. PMID:17631381

  2. Stochastic model for the fluctuations of the atmospheric concentration of radionuclides and its application to uncertainty evaluation

    NASA Astrophysics Data System (ADS)

    Ichige, Hiroyuki; Fukuchi, Shun; Hatano, Yuko

    2015-02-01

    We propose a new model of the atmospheric concentration of a radionuclide with the inclusion of fluctuations of the concentration. The model is a stochastic differential equation and we derive the analytic solution of the equation. The solution agrees very well with the Chernobyl Cs-137 data. The advantage of the model is that the uncertainty in radiation exposure risk, with regard to the concentration fluctuations, can be quantitatively estimated. We show the range of fluctuations of ±σ, ±2σ, ±3σ in the 10-year measurement of the atmospheric concentration in Chernobyl and confirmed the validity of the model.

  3. Concentrator Systems

    NASA Astrophysics Data System (ADS)

    Luque-Heredia, Ignacio; Luque, Antonio

    2015-10-01

    The following sections are included: * Introduction * The early development of CPV * Concentrator solar cells * Optics for photovoltaic concentrators * Photovoltaic concentration modules * Tracking systems for photovoltaic concentration * High-concentration systems * Rating and performance * Cost considerations * Conclusions * References

  4. An experimental and modeling study of humic acid concentration effect on H(+) binding: Application of the NICA-Donnan model.

    PubMed

    Vidali, Roza; Remoundaki, Emmanouela; Tsezos, Marios

    2009-11-15

    Humic substances are the most abundant components of the colloidal and the dissolved fraction of natural organic matter (NOM) and they are characterized by a strong binding capacity for both metals and organic pollutants, affecting their mobility and bioavailability. The understanding of the humic acidic character is the first necessary step for the study of the mechanisms of binding of other positively charged soluble metal species by humic molecules. The present work, which constitutes part of the Ph.D. thesis of Roza Vidali, reports results on the influence of the concentration of humic acids on the binding of protons obtained through both an experimental and a modeling approach. A reference purified peat humic acid (PPHA) isolated by the International Humic Substances Society (IHSS) and a humic acid from a Greek soil (GHA) were experimentally studied at various humic acid concentrations, ranging from 20 to 200mgL(-1). The proton binding isotherms obtained at different humic acid concentrations have shown that proton binding is dependent on the concentration of both humic acids. Proton binding experimental data were fitted to the NICA-Donnan model and the model parameter values were calculated for humic acid concentrations of 20 and >or=100mgL(-1). The results obtained for the NICA-Donnan parameters at humic acid concentrations >or=100mgL(-1) are in excellent agreement with those reported in the literature. However, these model parameter values cannot be used for modeling and predicting cation binding in natural aquatic systems, where humic acid concentrations are much lower. Two sets of the NICA-Donnan parameters are reported: one for humic acid concentrations of >or=100mgL(-1) and one for humic acid concentration of 20mgL(-1). The significance of the parameters values for each concentration level is also discussed. PMID:19744666

  5. Measured and predicted airshed concentrations of methyl bromide in an agricultural valley and applications to exposure assessment

    NASA Astrophysics Data System (ADS)

    Honaganahalli, Puttanna S.; Seiber, James N.

    A field study was conducted in September 1995 to measure the ambient atmospheric concentrations of methyl bromide (MeBr) in the Salinas Valley, California. Air concentrations of MeBr were measured at 11 sites located on the adjacent mountains, valley floor and at the Pacific Ocean coast over a 4-d period. The concentrations ranged up to 8.98 μg m -3. Industrial Source Complex Short Term 3 (ISCST3) and CALPUFF dispersion model simulations were performed with several fumigated fields serving as sources, using two estimates of source strengths from published flux values. CALPUFF was driven by 3D meteorology from CALMET. With the lower of the two estimates, the ISCST3 model underpredicted concentrations for 76% of data and averaged 66% of measured, and the CALPUFF model also underpredicted concentrations for 67% of observations and averaged 84% of measured. With the higher of the two estimates the ISCST3 overpredicted by a factor of two for 67% of data, and CALPUFF overpredicted concentrations by a factor of 1.6 for over 50% of data. Between the model predicted and measured concentrations, the coefficient of determination, R 2, was ≈0.7 for both source strengths with ISCST3 model. The R 2 with CALPUFF model was 0.55 and 0.82 with source strength estimated from two prior flux studies. The margin of exposure (MOE) for the population of the city of Salinas was calculated based on the measured ambient concentrations and compared with the current benchmark used by US-EPA and California Department of Pesticide Regulation for acceptable human health risk. Based on the models predicted worst-case exposure concentration, the MOE for acute effects was approximately 10,000. For chronic effects it was approximately 100, indicating a need for attention to exposure to MeBr in areas of intense methyl bromide use.

  6. An array sensor consisting of a single indicator with multiple concentrations and its application in ion discrimination.

    PubMed

    Li, Hui; Jia, Mingyan; Askim, Jon R; Zhang, Yu; Duan, Chunfeng; Guan, Yafeng; Feng, Liang

    2014-12-18

    Optical sensor arrays typically require a large set of chemically responsive colorants to enhance discrimination capability. Conversely, we have proven that by using multiple concentrations of one indicator, the discrimination of various analytes could be realized. PMID:25350153

  7. Low concentration ratio solar array for low Earth orbit multi-100kW application. Volume 2: Drawings

    NASA Technical Reports Server (NTRS)

    Nalbandian, S. J.; French, E. P.

    1982-01-01

    A preliminary design effort directed toward a low concentration ratio photovoltaic array system based on 1984 technology and capable of delivering multi-hundred kilowatts (300 kW to 100 kW range) in low Earth orbit. The array system consists of two or more array modules each capable of delivering between 113 kW to 175 kW using silicon solar cells or gallium arsenide solar cells, respectively. The array module deployed area is 1320 square meters and consists of 4356 pyramidal concentrator elements. The module, when stowed in the Space Shuttle's payload bay, has a stowage volume of a cube with 3.24 meters on a side. The concentrator elements are sized for a geometric concentration ratio (GCR) of six with an aperture area of 0.5 meters x 0.5 meters. Drawings for the preliminary design configuration and for the test hardware that was fabricated for design evaluation and test are provided.

  8. Application of Monte Carlo simulation to estimate probabilities for the best and health conservative estimates of receptor well concentrations

    SciTech Connect

    Not Available

    1989-08-01

    This report presents a Monte Carlo Simulation analysis of the fate and transport of Contaminants in groundwater at the Lawrence Livermore National Laboratory Livermore Site. The result of this analysis are the cumulative distribution function (CDF) of the maximum 70-year average and peak concentrations of the four chemicals of concern (TCE, PCE, chloroform, and other VOCs'') at the near-field and three far-field wells. These concentration CDFs can be used to estimate the probability of occurrence of the concentrations previously predicted using the deterministic model, and to conduct an enhanced exposure and risk assessment for the Remedial Investigation and Feasibility Study (RI/FS). This report provides a description of the deterministic fate and transport model (PLUME) which was linked to the Monte Carlo Shell to estimate the CDF of the receptor-well chemical concentrations. 6 refs., 21 figs., 12 tabs.

  9. Application of passive sampling for measuring dissolved concentrations of organic contaminants in the water column at three marine superfund sites

    EPA Science Inventory

    At contaminated sediment sites, including U.S. EPA Superfund sites, it is critical to measure water column concentrations of freely dissolved contaminants to understand the complete exposure of aquatic organisms to hydrophobic organic contaminants (HOCs). However, historically a...

  10. Recovery of fibrinogen concentrate after intraosseous application is equivalent to the intravenous route in a porcine model of hemodilution

    PubMed Central

    Schlimp, Christoph J.; Solomon, Cristina; Keibl, Claudia; Zipperle, Johannes; Nürnberger, Sylvia; Öhlinger, Wolfgang; Redl, Heinz; Schöchl, Herbert

    2014-01-01

    BACKGROUND Fibrinogen concentrate is increasingly considered as a hemostatic agent for trauma patients experiencing bleeding. Placing a venous access is sometimes challenging during severe hemorrhage. Intraosseous access may be considered instead. Studies of intraosseous infusion of coagulation factor concentrates are limited. We investigated in vivo recovery following intraosseous administration of fibrinogen concentrate and compared the results with intravenous administration. METHODS This study was performed on 12 pigs (mean [SD] body weight, 34.1 [2.8] kg). Following controlled blood loss (35 mL/kg) and fluid replacement with balanced crystalloid solution, intraosseous (n = 6) administration of fibrinogen concentrate (80 mg per kilogram of bodyweight) in the proximal tibia was compared with intravenous (n = 6) administration of the same dose (fibrinogen infusion time approximately 5 minutes in both groups). The following laboratory parameters were assessed: blood cell count, prothrombin time index, activated partial thromboplastin time, and plasma fibrinogen concentration (Clauss assay). Coagulation status was also assessed by thromboelastometry. RESULTS All tested laboratory parameters were comparable between the intraosseous and intravenous groups at baseline, hemodilution, and 30 minutes after fibrinogen concentrate administration. In vivo recovery of fibrinogen was also similar in the two groups (89% [23%] and 91% [22%], respectively). There were no significant between-group differences in any of the thromboelastometric parameters. Histologic examination indicated no adverse effects on the tissue surrounding the intraosseous administration site. CONCLUSION This study suggests that intraosseous administration of fibrinogen concentrate results in a recovery of fibrinogen similar to that of intravenous administration. The intraosseous route of fibrinogen concentrate could be a valuable alternative in situations where intravenous access is not feasible or would

  11. Geographical distribution of the annual mean radon concentrations in primary schools of Southern Serbia - application of geostatistical methods.

    PubMed

    Bossew, P; Žunić, Z S; Stojanovska, Z; Tollefsen, T; Carpentieri, C; Veselinović, N; Komatina, S; Vaupotič, J; Simović, R D; Antignani, S; Bochicchio, F

    2014-01-01

    Between 2008 and 2011 a survey of radon ((222)Rn) was performed in schools of several districts of Southern Serbia. Some results have been published previously (Žunić et al., 2010; Carpentieri et al., 2011; Žunić et al., 2013). This article concentrates on the geographical distribution of the measured Rn concentrations. Applying geostatistical methods we generate "school radon maps" of expected concentrations and of estimated probabilities that a concentration threshold is exceeded. The resulting maps show a clearly structured spatial pattern which appears related to the geological background. In particular in areas with vulcanite and granitoid rocks, elevated radon (Rn) concentrations can be expected. The "school radon map" can therefore be considered as proxy to a map of the geogenic radon potential, and allows identification of radon-prone areas, i.e. areas in which higher Rn radon concentrations can be expected for natural reasons. It must be stressed that the "radon hazard", or potential risk, estimated this way, has to be distinguished from the actual radon risk, which is a function of exposure. This in turn may require (depending on the target variable which is supposed to measure risk) considering demographic and sociological reality, i.e. population density, distribution of building styles and living habits. PMID:24231373

  12. Fungal population levels in soils of commercial swine waste application sites in Mississippi and relationships to soil nutrient concentrations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known of how commercial applications of animal wastes to agricultural soils affect soil microbial populations. This study was undertaken to determine whether commercial applications of liquid swine waste to pasture soils in Mississippi, USA, influence fungal population levels in soil, and...

  13. Subsurface band application of poultry litter and its influence on Phosphorus concentration and retention after runoff from permanent pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Excessive P loss from agricultural fields has been identified as a major cause of eutrophication to river, lakes, and streams. To minimize and mitigate P loss from poultry litter (PL) applications, new technology is being developed for subsurface band application of litter below the soil surface. Th...

  14. Effects of surface applications of biosolids on groundwater quality and trace-element concentrations in crops near Deer Trail, Colorado, 2004-2010

    USGS Publications Warehouse

    Yager, Tracy J.B.; Crock, James G.; Smith, David B.; Furlong, Edward T.; Hageman, Philip L.; Foreman, William T.; Gray, James L.; ReVello, Rhiannon C.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with Metro Wastewater Reclamation District (Metro District), studied biosolids composition and the effects of biosolids applications on groundwater quality and trace-element concentrations in crops of the Metro District properties near Deer Trail, Colorado, during 2004 through 2010. Priority parameters for each monitoring component included the nine trace elements regulated by Colorado for biosolids (arsenic, cadmium, copper, lead, mercury, molybdenum, nickel, selenium, and zinc); other constituents also were analyzed. All concentrations for the priority parameters in monthly biosolids samples were less than Colorado regulatory limits, and the concentrations were relatively consistent. Biosolids likely were the largest source of nitrogen and phosphorus on the Metro District properties. Plutonium isotopes were not detected in the biosolids, but many organic wastewater compounds (organic wastewater compounds: wastewater indicators, pharmaceuticals, and hormones) were detected in substantial concentrations relative to minimum reporting levels and various surface-water concentrations. Bismuth, copper, mercury, nitrogen, phosphorus, silver, biogenic sterols, detergent degradates, disinfectants, fire retardants, fragrances, pharmaceuticals, and plasticizers would be the most likely biosolids signature to indicate the presence of Metro District biosolids in soil or streambed sediment from the study area. Antimony, cadmium, cobalt, copper, molybdenum, nickel, nitrogen, phosphorus, selenium, tungsten, vanadium, zinc, detergent degradates, disinfectants, fire retardants, fragrances, pharmaceuticals or their degradates, and plasticizers would be the most likely biosolids signature for groundwater and surface water in the study area. More biosolids-signature components detected and larger concentration differences from untreated materials, baseline, and blank samples indicate more evidence of biosolids presence or effects

  15. Application of empirical model to predict background metal concentration in mixed carbonate-alumosilicate sediment (Adriatic Sea, Croatia).

    PubMed

    Felja, Igor; Romić, Marija; Romić, Davor; Bakić, Helena; Pikelj, Kristina; Juračić, Mladen

    2016-05-15

    A 96m long sediment core (S10-33) from the Mali Ston Channel (Adriatic Sea) showed large natural variation in carbonate share (between 1% and 95%) and concentration of elements. These variations indicate rather significant changes in fine-grained sediment that was deposited in this area during Younger Pleistocene and Holocene. Unaffected by anthropogenic influence, sediment in the core was used to determine background concentration of trace elements in sediment with various carbonate content. Here we propose a method of the normalization of trace elements to carbonate share, in order to assess natural/background concentration of metals in sediments consisting of carbonates and alumosilicates in various proportions. Six characteristic metals (Co, Cr, Cu, Ni, Pb, and Zn) that were normalized to carbonate share showed very good correlation, with much higher background concentrations in alumosilicate than in carbonate end member. Simple formulas were proposed to easily determine background concentration of these elements, in coastal and shelf depositional environments with mixed carbonate-alumosilicate sediments. PMID:26975609

  16. Effects of graphene oxide concentration on optical properties of ZnO/RGO nanocomposites and their application to photocurrent generation

    SciTech Connect

    Azarang, Majid E-mail: azarang@phys.usb.ac.ir; Shuhaimi, Ahmad; Sookhakian, M.; Yousefi, Ramin E-mail: raminyousefi@iaumis.ac.ir

    2014-08-28

    The effects of different concentrations of graphene oxide (GO) on the structure and optical properties of ZnO nanoparticles (NPs) were investigated. The nanocomposites were synthesized via the sol-gel method in a gelatin medium. X-ray diffraction patterns (XRD) and Fourier transform infrared spectroscopy indicated that the GO sheets were reduced and changed to reduced GO (RGO) during the calcination of the nanocomposites at 400 °C. In addition, the XRD patterns of the NPs indicated a hexagonal (wurtzite) structure for all the products. Microscopic studies showed that the NPs were decorated and dispersed on the RGO sheets very well. However, these studies revealed that the RGO concentration had an effect on the crystal growth process for the ZnO NPs. Furthermore, these studies showed that the NPs could be grown with a single crystal quality in an optimum RGO concentration. According to the XRD results that were obtained from pure ZnO NPs, the calcinations temperature was decreased by the RGO. UV–vis and room temperature photoluminescence studies showed that the optical properties of the ZnO/RGO nanocomposite were affected by the RGO concentration. Finally, the obtained ZnO/RGO nanocomposite was used to generate a photocurrent. Observations showed that the photocurrent intensity of the nanocomposite was significantly increased by increasing the RGO, with an optimum RGO concentration.

  17. Application of Acoustic and Optic Methods for Estimating Suspended-Solids Concentrations in the St. Lucie River Estuary, Florida

    USGS Publications Warehouse

    Patino, Eduardo; Byrne, Michael J.

    2004-01-01

    Acoustic and optic methods were applied to estimate suspended-solids concentrations in the St. Lucie River Estuary, southeastern Florida. Acoustic Doppler velocity meters were installed at the North Fork, Speedy Point, and Steele Point sites within the estuary. These sites provide varying flow, salinity, water-quality, and channel cross-sectional characteristics. The monitoring site at Steele Point was not used in the analyses because repeated instrument relocations (due to bridge construction) prevented a sufficient number of samples from being collected at the various locations. Acoustic and optic instruments were installed to collect water velocity, acoustic backscatter strength (ABS), and turbidity data that were used to assess the feasibility of estimating suspended-solids concentrations in the estuary. Other data collected at the monitoring sites include tidal stage, salinity, temperature, and periodic discharge measurements. Regression analyses were used to determine the relations of suspended-solids concentration to ABS and suspended-solids concentration to turbidity at the North Fork and Speedy Point sites. For samples used in regression analyses, measured suspended-solids concentrations at the North Fork and Speedy Point sites ranged from 3 to 37 milligrams per liter, and organic content ranged from 50 to 83 percent. Corresponding salinity for these samples ranged from 0.12 to 22.7 parts per thousand, and corresponding temperature ranged from 19.4 to 31.8 ?C. Relations determined using this technique are site specific and only describe suspended-solids concentrations at locations where data were collected. The suspended-solids concentration to ABS relation resulted in correlation coefficients of 0.78 and 0.63 at the North Fork and Speedy Point sites, respectively. The suspended-solids concentration to turbidity relation resulted in correlation coefficients of 0.73 and 0.89 at the North Fork and Speedy Point sites, respectively. The adequacy of the

  18. Photovoltaic concentrator module technology

    NASA Astrophysics Data System (ADS)

    Richards, Elizabeth H.; Chamberlin, Jay L.; Boes, Eldon C.

    Significant developments in the development of photovoltaic (PV) concentrator technology are described. Concentrator cell research, advances in PV concentrator cell technology, and PV concentrator module development are described. Reliability issues currently of concern, including the applicability of wet insulation resistance tests to concentrator modules, correlation of accelerated thermal cycling tests with life expectancy in the field, and the importance of quality assurance during manufacture, are discussed. Two PV concentrator power systems installed in 1989 are discussed. A PV concentrator initiative program established by the DOE is given, and the results of the latest cost study are presented.

  19. Concentrated flow experiments on burned and unburned sagebrush communities: Applications for the Rangeland Hydrology and Erosion Model.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The risk of increased runoff and water erosion is greater after fire on many rangelands. Recent experiments on steep sagebrush rangelands have shown that concentrated flow detachment and transport is the dominant postfire erosion process. Rainfall simulation studies have demonstrated that runoff a...

  20. Simulating nitrate-nitrogen concentration from a subsurface drainage system in response to nitrogen application rates using RZWQM2

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Computer models have been widely used to evaluate the impact of agronomic management on nitrogen dynamics in subsurface drained field. The objective of this note was to evaluate the performance of Root Zone Water Quality Model (RZWQM2 version 2.0) in simulating the response of NO3-N concentration in...

  1. Effect of sewage-sludge application on concentrations of higher-brominated diphenyl ethers in soils and earthworms.

    PubMed

    Sellström, Ulla; de Wit, Cynthia A; Lundgren, Nadja; Tysklind, Mats

    2005-12-01

    Polybrominated diphenyl ethers (PBDEs), including octa-decaBDEs, were found in soil and earthworm samples collected in 2000 from three research stations (reference plots and sewage-sludge-amended plots) and two farms (reference and amended/flooded soils) in Sweden. Sewage-sludge amendment at the research stations increased concentrations of all BDE congeners 2- to 13-fold, with the highest increases for BDE-209. Concentrations 100-to 1000-fold higher were seen in contaminated soils at both farms. BDE-209 was the predominant congener in all soils. sigmaPBDE concentrations in worms ranged from 3.1 to 38 000 ng/g lipid weight and were correlated to soil concentrations, including the octa-decaBDEs. Biota-soil accumulation factors declined in the following order: TeBDE > PeBDE > HxBDE > OcBDE > NoBDE > DeBDE, and ranged from 0.3 to 2 for the octa-decaBDEs. Thus, higher-brominated PBDEs, including BDE-209, are bioavailable from soils and accumulate in earthworms, presenting an exposure pathway into the terrestrial food web. High levels found at one farm 20 years after the last use of PBDEs indicate high persistence of PBDEs in soils, including BDE-209. No evidence of photolytic debromination of BDE-209 in soils was seen. PMID:16382926

  2. Phenomenological study and application of the combined influence of iron concentration and irradiance on the photo-Fenton process to remove micropollutants.

    PubMed

    Carra, Irene; García Sánchez, José Luis; Casas López, José Luis; Malato, Sixto; Sánchez Pérez, José Antonio

    2014-04-15

    The presence of low concentrations of persistent pollutants in waters (μg/L or ng/L), also called micropollutants, brings as a consequence the need to apply advanced oxidation treatments for their removal. The successful application of solar-driven photo-Fenton to treat highly polluted wastewaters (g/L and mg/L of pollutants) has prompted its application to lowly polluted effluents. However, a decrease in contaminant concentration may involve an alteration in the intrinsic process phenomenon, which until now has only been widely studied at the milligram-per-litre level or higher with this process. The aim of this research was to study the combined influence of the operating variable (iron concentration) and the environmental variable (irradiance) and application on the photo-Fenton process at pH2.8 when removing micropollutants. For this purpose, experimentation was carried out at laboratory and pilot plant scales with a biocide mixture of acetamiprid (ACTM), thiabendazole (TBZ) and imazalil (IMZ) (100 μg/L each) as the model pollutant. Results indicated that above 15 WUV/m(2) and a light path length of 5 cm (the most commonly used path for this type of application) iron concentration limited the process and there was irradiance excess under these conditions. On the other hand, and given the circumstances of irradiance excess, a higher light path length (10 cm) was assessed. Results showed that path lengths wider than 5 cm are recommended since more wastewater volume could be treated with a higher process rate per surface unit. PMID:24530592

  3. [Effect of atmospheric CO2 concentration and nitrogen application level on absorption and transportation of nutrient elements in oilseed rape].

    PubMed

    Wang, Wen-ming; Zhang, Zhen-hua; Song, Hai-xing; Liu, Qiang; Rong, Xiang-min; Guan, Chun-yun; Zeng, Jing; Yuan, Dan

    2015-07-01

    Effect of elevated atmospheric-CO2 (780 µmol . mol-1) on the absorption and transportation of secondary nutrient elements (calcium, magnesium, sulphur) and micronutrient elements (iron, manganese, zinc, molybdenum and boron) in oilseed rape at the stem elongation stage were studied by greenhouse simulated method. Compared with the ambient CO2 condition, the content of Zn in stem was increased and the contents of other nutrient elements were decreased under the elevated atmospheric-CO2 with no nitrogen (N) application; the contents of Ca, S, B and Zn were increased, and the contents of Mg, Mn, Mo and Fe were decreased under the elevated atmospheric CO2 with N application (0.2 g N . kg-1 soil); except the content of Mo in leaf was increased, the contents of other nutrient elements were decreased under the elevated atmospheric-CO2 with two levels of N application. Compared with the ambient CO2 condition, the amounts of Ca and S relative to the total amount of secondary nutrient elements in stem and the amounts of B and Zn relative to the total amount of micronutrient elements in stem were increased under the elevated-CO2 treatment with both levels of N application, and the corresponding values of Mg, Fe, Mn and Mo were decreased; no-N application treatment increased the proportion of Ca distributed into the leaves, and the proportion of Mg distributed into leaves was increased by the normal-N application level; the proportions of Mn, Zn and Mo distributed into the leaves were increased at both N application levels. Without N application, the elevation of atmospheric CO2 increased the transport coefficients of SFe, Mo and SS,B, but decreased the transport coefficients of SMg,Fe, SMg, Mn and SS,Fe, indicating the proportions of Mo, S transported into the upper part of plant tissues was higher than that of Fe, and the corresponding value of B was higher than that observed for S, the corresponding value of Mg was higher than that of Fe and Mn. Under normal-N application

  4. Simultaneous determination of Si, Al and Na concentrations by particle induced gamma-ray emission and applications to reference materials and ceramic archaeological artifacts

    NASA Astrophysics Data System (ADS)

    Dasari, K. B.; Chhillar, S.; Acharya, R.; Ray, D. K.; Behera, A.; Lakshmana Das, N.; Pujari, P. K.

    2014-11-01

    A particle induced gamma ray emission (PIGE) method using 4 MeV proton beam was standardized for simultaneous determination of Si, Al and Na concentrations and has been applied for non-destructive analysis of several reference materials and archaeological clay pottery samples. Current normalized count rates of gamma-rays for the three elements listed above were obtained by an in situ method using Li as internal standard. The paper presents application of the in situ current normalized PIGE method for grouping study of 39 clay potteries, obtained from Rajasthan and Andhra Pradesh states of India. Grouping of artifacts was carried out using the ratios of SiO2 to Al2O3 concentrations, due to their non volatile nature. Powder samples and elemental standards in pellet forms (cellulose matrix) were irradiated using the 4 MeV proton beam (∼10 nA) from the 3 MV tandem accelerator at IOP Bhubaneswar, and assay of prompt gamma rays was carried out using a 60% relative efficiency HPGe detector coupled to MCA. The concentration ratio values of SiO2/Al2O3 indicated that pottery samples fell into two major groups, which are in good agreement with their collection areas. Reference materials from IAEA and NIST were analyzed for quantification of Si, Al and Na concentrations as a part of validation as well as application of PIGE method.

  5. Development and application of a sensitive method to determine concentrations of acrolein and other carbonyls in ambient air.

    PubMed

    Cahill, Thomas M; Charles, M Judith; Seaman, Vincent Y

    2010-05-01

    Acrolein, an unsaturated aldehyde, has been identified as one of the most important toxic air pollutants in recent assessments of ambient air quality. Current methods for determining acrolein concentrations, however, suffer from poor sensitivity, selectivity, and reproducibility. The collection and analysis of unsaturated carbonyls, and acrolein in particular, is complicated by unstable derivatives, coelution of similar compounds, and ozone interference. The primary objective of this research was to develop an analytical method to measure acrolein and other volatile carbonyls present in low part-per-trillion concentrations in ambient air samples obtained over short sampling periods. The method we devised uses a mist chamber in which carbonyls from air samples form water-soluble adducts with bisulfite in the chamber solution, effectively trapping the carbonyls in the solution. The mist chamber methodology proved effective, with collection efficiency for acrolein of at least 70% for each mist chamber at a flow rate of approximately 17 L/min. After the sample collection, the carbonyls are liberated from the bisulfite adducts through the addition of hydrogen peroxide, which converts the bisulfite to sulfate, reversing the bisulfite addition reaction. The free carbonyls are then derivatized by o-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA*), which stabilizes the analytes and makes them easier to detect by electron-capture negative ionization mass spectrometry (ECNI-MS). The derivatives are then extracted and analyzed by gas chromatography-mass spectrometry (GC-MS). The mist chamber method was applied in a field test to determine the extent of acrolein in ambient air near the Peace Bridge plaza in Buffalo, New York, an area of heavy traffic near a major border crossing between the United States and Canada. In addition, XAD-2 adsorbent cartridges coated with 2-(hydroxymethyl)piperidine (2-HMP) according to Occupational Safety and Health Administration (OSHA) Method

  6. Theoretical investigation of fluorescence concentration quenching in two-dimensional disordered systems. Application to chlorophyll a in monolayers of dioleylphosphatidylcholine

    SciTech Connect

    Boulu, L.G.; Patterson, L.K.; Chauvet, J.P.; Kozak, J.J.

    1987-01-15

    A master equation approach is used for investigating energy transfer and trapping in two-dimensional disordered systems, where the traps are statistical pairs of pigment molecules closer than a critical distance R/sub c/. Fluorescence decay curves are calculated over a range of concentrations as a function of R/sub c/ and the Foerster transfer radius R-bar/sub 0/. The concentration dependence of the lifetimes is compared to the fluorescence self-quenching data that Chauvet et al. obtained from real-time measurements in monolayers of chlorophyll a and dioleylphosphatidylcholine (DOL). This dependence is found to be close to second order and for a choice of R/sub c/ = 10 A the experimental data are fit if R-bar/sub 0/ = 78 +- 2 A. This value is in close agreement with those found in the literature from depolarization measurements.

  7. Application of high rate nitrifying trickling filters to remove low concentrations of ammonia from reclaimed municipal wastewater.

    PubMed

    van den Akker, B; Holmes, M; Short, M D; Cromar, N J; Fallowfield, H J

    2010-01-01

    The interference of ammonia with the chlorination process is a problem for many reclaimed water treatment plant operators. This paper presents the findings from a series of pilot experiments that investigated the efficacy of high flow rate nitrifying trickling filters (NTFs) for the removal of low concentrations of ammonia (0.5-3.0 mg N L(-1)) from reclaimed wastewater. Results showed that nitrification was impeded by a combination of high organic carbon loads and aquatic snails, which consumed much of the active biomass. With adequate snail control, nitrification rates (0.3-1.1 g NH(4)-N m(-2) d(-1)) equivalent to that of traditional wastewater NTFs were achieved, despite operating under comparably low ammonia feed concentrations and high hydraulic flow rates. PMID:20453314

  8. Effect of Zinc Nitrate Concentration on the Optical and Morphological Properties of ZnO Nanorods for Photovoltaic Applications.

    PubMed

    Kim, Sung Jae; Anwar, M S; Heo, Si-Nae; Koo, Bon Heun

    2016-06-01

    We report the effect of zinc nitrate (ZN) concentration on the growth of zinc oxide (ZnO) nanorods and their optical and morphological properties. As prepared ZnO nanorods on glass substrate were characterized using field emission scanning electron microscopy (FE-SEM), ultra violet-visible (UV-Vis), Raman and Photo-luminescence (PL) spectroscopy. FE-SEM results show that the nanorods were obtained for the 0.033 and 0.053 M concentration of ZN. As the ZN concentration increased from 0.033 M to 0.053 M, the diameter of the nanorods was increased. It indicated that the diameter of the nanorods was affected by the ZN concentration. The Raman spectra of nanorods show only one peak at 438 cm(-1) corresponding to E2(high) high mode, which means that ZnO nanorods grown perpendicularly on the glass substrate, i.e., the ZnO nanorod arrays are highly c-axis oriented. Room-temperature PL spectrum of the as-grown ZnO nanorods reveals a near-band-edge (NBE) emission peak and defect induced green light emission. The green light emission band at -579 nm might be attributed to surface oxygen vacancies or defects. The UV-visible measurements reflect that the total transmittance for the as grown ZnO nanorods is over 80%. The simple technique presented in this study to grow ZnO nanorods on a glass substrate can be helpful for making the cost effective photovoltaic devices. PMID:27427680

  9. The synthesis of hydroxyapatite with different crystallinities by controlling the concentration of recombinant CEMP1 for biological application.

    PubMed

    Chen, Xiaofeng; Liu, Yu; Yang, Jie; Wu, Wenlei; Miao, Leiying; Yu, Yijun; Yang, Xuebin; Sun, Weibin

    2016-02-01

    Cementum protein 1 (CEMP1) has been reported to be cementum specific and it plays a role in the properties and structure of cementum mineralization. This study was carried out to test the hypothesis that, CEMP1 had the capacity to guide ordered HA formation as it accumulated at targeting site. Crystals induced by protein were prepared by biomimetic method. The effects of CEMP1 concentrations (0-100μg/ml) on the rate of calcium phosphate precipitation was monitored during 48h, while the formed mineral phases were assessed utilizing transmission electron microscope (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The results showed that recombinant cementum protein 1 (rhCEMP1) affected the crystal nucleation and growth. At lower rhCEMP1 concentrations (0-50μg/ml), limited mineral formation occurred and only small bundles of HA crystals were found. However, with 100μg/ml of rhCEMP1, a predominance of organized linear needle-like HA crystals was observed. FTIR revealed the characteristic bands of HA appearing at 1106cm(-1), 557cm(-1), and 598cm(-1). Therefore, increasing the concentration of rhCEMP1 can lead to the formation of ordered bundles of HA crystals in vitro. PMID:26652387

  10. Application of Hollow Fiber Forward Osmosis Membranes for Produced and Process Water Volume Reduction: An Osmotic Concentration Process.

    PubMed

    Minier-Matar, Joel; Santos, Ana; Hussain, Altaf; Janson, Arnold; Wang, Rong; Fane, Anthony G; Adham, Samer

    2016-06-01

    Produced and process water (PPW) from oil and gas operations, specifically in Qatar, are disposed of by deep well injection in onshore facilities. Disposing large volumes of PPW may affect deep well formation sustainability highlighting the need for effective PPW management. Forward osmosis (FO) was applied as an "osmotic concentration" process to reduce PPW injection volumes by 50% using brines and seawater as draw solutions (DS). The energy intensive step of restoring the salinity of the DS was eliminated; the diluted DS would be simply discharged to the ocean. Both hollow fiber and flat sheet FO membranes were tested and the former exhibited better flux and rejection; they are the focus of this study. Optimization experiments, conducted using Box-Behnken statistical design, confirmed that temperature and DS concentration had a substantial effect on performance. To validate the concept, a long-term experiment, under optimized conditions, was conducted with PPW as feed and brine from thermal desalination plant as DS which yielded an average flux of 24 L/m(2)h. The results confirmed that low-energy osmotic concentration FO has the potential for full-scale implementation to reduce PPW injection volumes. Pilot testing opportunities are being evaluated to demonstrate the effectiveness of this technology under field conditions. PMID:27161935

  11. Design and application of a class of sensors to monitor Ca2+ dynamics in high Ca2+ concentration cellular compartments

    PubMed Central

    Tang, Shen; Wong, Hing-Cheung; Wang, Zhong-Min; Huang, Yun; Zou, Jin; Zhuo, You; Pennati, Andrea; Gadda, Giovanni; Delbono, Osvaldo; Yang, Jenny J.

    2011-01-01

    Quantitative analysis of Ca2+ fluctuations in the endoplasmic/sarcoplasmic reticulum (ER/SR) is essential to defining the mechanisms of Ca2+-dependent signaling under physiological and pathological conditions. Here, we developed a unique class of genetically encoded indicators by designing a Ca2+ binding site in the EGFP. One of them, calcium sensor for detecting high concentration in the ER, exhibits unprecedented Ca2+ release kinetics with an off-rate estimated at around 700 s−1 and appropriate Ca2+ binding affinity, likely attributable to local Ca2+-induced conformational changes around the designed Ca2+ binding site and reduced chemical exchange between two chromophore states. Calcium sensor for detecting high concentration in the ER reported considerable differences in ER Ca2+ dynamics and concentration among human epithelial carcinoma cells (HeLa), human embryonic kidney 293 cells (HEK-293), and mouse myoblast cells (C2C12), enabling us to monitor SR luminal Ca2+ in flexor digitorum brevis muscle fibers to determine the mechanism of diminished SR Ca2+ release in aging mice. This sensor will be invaluable in examining pathogenesis characterized by alterations in Ca2+ homeostasis. PMID:21914846

  12. A New Approach in Optimizing the Induction Heating Process Using Flux Concentrators: Application to 4340 Steel Spur Gear

    NASA Astrophysics Data System (ADS)

    Barka, Noureddine; Chebak, Ahmed; El Ouafi, Abderrazak; Jahazi, Mohammad; Menou, Abdellah

    2014-09-01

    The beneficial effects of using flux concentrators during induction heat treatment process of spur gears made of 4340 high strength steel is demonstrated using 3D finite element model. The model is developed by coupling electromagnetic field and heat transfer equations and simulated by using Comsol software. Based on an adequate formulation and taking into account material properties and process parameters, the model allows calculating temperature distribution in the gear tooth. A new approach is proposed to reduce the electromagnetic edge effect in the gear teeth which allows achieving optimum hardness profile after induction heat treatment. In the proposed method, the principal gear is positioned in sandwich between two other gears having the same geometry that act as flux concentrators. The gap between the gear and the flux concentrators was optimized by studying temperature variation between the tip and root regions of gear teeth. Using the proposed model, it was possible identifying processing conditions that allow for quasi-uniform final temperature profile in the medium and high frequency conditions during induction hardening of spur gears.

  13. 40 CFR 122.23 - Concentrated animal feeding operations (applicable to State NPDES programs, see § 123.25).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CFR part 412. When additional information is necessary to complete the notice of intent or clarify... follow the procedures applicable to draft permits set forth in 40 CFR 124.11 through 124.13. The Director... public to comment and request a hearing that differs from the time period specified in 40 CFR 124.10....

  14. 40 CFR 122.23 - Concentrated animal feeding operations (applicable to State NPDES programs, see § 123.25).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CFR part 412. When additional information is necessary to complete the notice of intent or clarify... follow the procedures applicable to draft permits set forth in 40 CFR 124.11 through 124.13. The Director... public to comment and request a hearing that differs from the time period specified in 40 CFR 124.10....

  15. Diagnosing pregnancy in free-ranging dugongs using fecal progesterone metabolite concentrations and body morphometrics: a population application.

    PubMed

    Burgess, Elizabeth A; Lanyon, Janet M; Brown, Janine L; Blyde, David; Keeley, Tamara

    2012-05-15

    Assessing reproductive status and monitoring reproductive rates is important in the effective management of vulnerable marine mammal species such as the dugong (Dugong dugon). Knowledge of the reproductive physiology of this species is limited, and determining reproductive parameters (e.g., sexual maturation, pregnancy, and reproductive senescence) has been restricted by a lack of non-lethal methods for assessing reproductive status in free-ranging individuals. The aim of this study was to develop a method to identify pregnant individuals in a wild dugong population. Using an enzymeimmunoassay, we quantified concentrations of fecal progesterone metabolites (fP) in 322 dugongs, including confirmed pregnant females (n=10), presumed non-pregnant adult females (n=25), juvenile females (n=24), subadult females (n=41), adult females of unknown pregnancy state (n=63), and males of all sizes (n=159). External body morphometrics of each dugong were measured, and confirmation of pregnancy in adult female dugongs was determined by ultrasonography or observation of subsequent neonates. Concentrations of fP were different between sexes and reproductive size classes (P<0.001), and ∼30-fold higher in confirmed pregnant dugongs (2017-7760 ng/g) compared to presumed non-pregnant females (30-221 ng/g), juvenile females (29-195 ng/g), and males (24-261 ng/g) (P<0.001). Body measures of maximum and anal girths, and teat length were all greater in confirmed pregnant females than presumed non-pregnant females (all P<0.05). We evaluated a Discriminant Function Analysis (DFA) to provide a model for predicting pregnant and non-pregnant dugongs. Cross-validated results showed that the DFA correctly classified 100% of pregnant and non-pregnant females using fP concentrations, body length, fineness ratio (an index of body shape), and teat length (a female reproductive trait). Using the DFA model, we classified the pregnancy status of all female dugongs and identified a total of 30 females

  16. Thin film Cu(In,Ga)Se2 materials and devices: a versatile material for flat-plate and concentrator photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Tuttle, John R.; Contreras, M. A.; Ward, J. S.; Tennant, A. L.; Ramanathan, K. R.; Keane, J.; Noufi, R. N.

    1995-08-01

    Thin-film Cu(In,Ga)Se2(CIGS) is used as the absorber in an all-thin-film solar cell for both conventional 1-sun and concentrator applications. The absorber fabrication process is represented by time-dependent profiles of elemental Cu, In, Ga, and Se fluxes. The Cu/(In+Ga) ratio determines the phase chemistry during growth whereas the Ga/(Ga+In) ratio determines the CIGS band gap profile. All film-growth processes enter the CIGS:CuxSe two-phase field where the CuxSe facilitates large grain growth. Characterization of cells under 1-sun illumination reveals world-record total-area performance of 17.1%. Improvements relative to previous cells are linked to decreased inter-diffusion of In and Ga within the absorber. Cell parameters include an open-circuit voltage (Voc) of 654 mV and short-circuit current (Jsc) of 33.9 mA/cm2. A second cell was fabricated for operation under concentration. The 1-sun, direct-spectrum measurement yielded at 15.1%- efficient cell. Under 5- and 22-sun concentration, the cell improved to 16.5% and 17.2%, respectively. This achievement is significant in that it proves a compatibility of polycrystalline thin-film and concentrator technologies. Further optimization could yield 1-sun performance in excess of 18% and concentrator performance in excess of 20%. A path to this goal is outlined.

  17. Design and Fabrication of a Dielectric Total Internal Reflecting Solar Concentrator and Associated Flux Extractor for Extreme High Temperature (2500K) Applications

    NASA Technical Reports Server (NTRS)

    Soules, Jack A.; Buchele, Donald R.; Castle, Charles H.; Macosko, Robert P.

    1997-01-01

    The Analex Corporation, under contract to the NASA Lewis Research Center (LeRC), Cleveland, Ohio, recently evaluated the feasibility of utilizing refractive secondary concentrators for solar heat receivers operating at temperatures up to 2500K. The feasibility study pointed out a number of significant advantages provided by solid single crystal refractive devices over the more conventional hollow reflective compound parabolic concentrators (CPCs). In addition to the advantages of higher concentration ratio and efficiency, the refractive concentrator, when combined with a flux extractor rod, provides for flux tailoring within the heat receiver cavity. This is a highly desirable, almost mandatory, feature for solar thermal propulsion engine designs presently being considered for NASA and Air Force thermal applications. Following the feasibility evaluation, the NASA-LeRC, NASA-Marshall Space Flight Center (MSFC), and Analex Corporation teamed up to design, fabricate, and test a refractive secondary concentrator/flux extractor system for potential use in the NASA-MSFC "Shooting Star" flight experiment. This paper describes the advantages and technical challenges associated with the design methodologies developed and utilized and the material and fabrication limitations encountered.

  18. Conceptual design study of concentrator enhanced solar arrays for space applications. 2kW Si and GaAs systems at 1 AU

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The effect of concentration level on the specific power for a deployable, thin, gallium arsenide cell array in geosynchronous orbit for 10 years in conjunction with a two dimensional flat plate trough concentrator (V trough) and also with a multiple flat plate concentrator was investigated as well as the effects for a conventional silicon cell array on a rigid substrate. For application to a thin GaAs array at 1 AU for 10 years, the V trough produces a 19% benefit in specific power and a dramatic reduction in array area, while the multiple flat plate collector design is not only of no benefit, but is a considerable detriment. The benefit it achieves by reducing array area is duplicated by the 2D design. For the silicon array on a rigid substrate, improvement in performance due to a concentrator with ordinary mirror coating is quite small: 9% increase in specific power, and 13% reduction in array area. When the concentrator mirrors are coated with an improved cold mirror coating, somewhat more significant results are obtained: 31% specific power improvement; and 27% area reduction. In both cases, a 10 year exposure reduces BOL output by 23%.

  19. Joint Application of Concentrations and Isotopic Signatures to Investigate the Global Atmospheric Carbon Monoxide Budget: Inverse Modeling Approach

    NASA Astrophysics Data System (ADS)

    Park, K.; Mak, J. E.; Emmons, L. K.

    2008-12-01

    Carbon monoxide is not only an important component for determining the atmospheric oxidizing capacity but also a key trace gas in the atmospheric chemistry of the Earth's background environment. The global CO cycle and its change are closely related to both the change of CO mixing ratio and the change of source strength. Previously, to estimate the global CO budget, most top-down estimation techniques have been applied the concentrations of CO solely. Since CO from certain sources has a unique isotopic signature, its isotopes provide additional information to constrain its sources. Thus, coupling the concentration and isotope fraction information enables to tightly constrain CO flux by its sources and allows better estimations on the global CO budget. MOZART4 (Model for Ozone And Related chemical Tracers), a 3-D global chemical transport model developed at NCAR, MPI for meteorology and NOAA/GFDL and is used to simulate the global CO concentration and its isotopic signature. Also, a tracer version of MOZART4 which tagged for C16O and C18O from each region and each source was developed to see their contributions to the atmosphere efficiently. Based on the nine-year-simulation results we analyze the influences of each source of CO to the isotopic signature and the concentration. Especially, the evaluations are focused on the oxygen isotope of CO (δ18O), which has not been extensively studied yet. To validate the model performance, CO concentrations and isotopic signatures measured from MPI, NIWA and our lab are compared to the modeled results. The MOZART4 reproduced observational data fairly well; especially in mid to high latitude northern hemisphere. Bayesian inversion techniques have been used to estimate the global CO budget with combining observed and modeled CO concentration. However, previous studies show significant differences in their estimations on CO source strengths. Because, in addition to the CO mixing ratio, isotopic signatures are independent tracers

  20. Influence of compost application on arsenic uptake by beans (Phaseolus vulgaris L.), irrigated with arsenic-contaminated waters at four different concentrations

    NASA Astrophysics Data System (ADS)

    Caporale, A. G.; Pigna, M.; Sommella, A.; Cozzolino, V.; Violante, A.

    2012-04-01

    The presence of arsenic (As) in soils and/or groundwaters, used for agricultural purposes, causes a strong abiotic stress to the cultivated plants, which results in the reduction of biomasses and yields, and the abundance of non-tradable products. It is therefore desirable to identify and develop production techniques capable of limiting the mobility and phyto-availability of As in soil, through the stabilization of the metalloid on the more recalcitrant soil fractions. Incorporation of compost into soil for As immobilization offers various potential advantages over other methods such as low-cost, simple methodology and low environmental impact. We studied the influence of compost application on the mobility and phyto-availability of As in soil, the growth of the bean plants irrigated with As-contaminated waters and their own As uptake. Bean was selected as test plant, because this crop is grown in several As-contaminated areas and suffers As toxicity. Bean plants growth was significantly affected by As and compost treatments. Increasing As concentration in the irrigation water decreased markedly the dry biomass, as a consequence of As phytotoxicity. The influence of compost application on plants growth was also significant, indicating the ability of the compost to alleviate the As phytotoxicity. Arsenic caused a reduction of the photosynthesis rate. By increasing As concentration in irrigation water, in fact, bean leaves showed a decrease in both chlorophyll A and B concentrations in their own mesophylls. However, by increasing level of compost application there was an increase of both chlorophylls concentrations in bean leaves. Arsenic concentration in roots was higher than that in shoots and bean yield. Bean plants showed a typical behavior of the plants sensitive to As toxicity, which usually tend to limit the As translocation from roots to shoots and yield. A low As allocation in bean yield is desirable, because a high As content in edible part of the plants

  1. Estimated human excretion rates of natural estrogens calculated from their concentrations in raw municipal wastewater and its application.

    PubMed

    Liu, Ze-Hua; Lu, Gui-Ning; Yin, Hua; Dang, Zhi

    2015-06-01

    Natural estrogens are important endocrine disrupting compounds (EDCs), which may pose adverse effects on our environment. To avoid time-consuming sample preparation and chemical analysis, estimation of their concentrations in municipal wastewater based on their human urine/feces excretion rates has been generally adopted. However, the data of excretion rates available are very limited and show significant difference among countries. In the context of increasing reporting on the concentrations of natural estrogens in municipal wastewater around the world, this study presented a simple method to estimate their human excretion rates based on the concentrations of natural estrogens in raw sewage. The estimated human excretion rates of natural estrogens among ten countries were obtained, which totally covered over 33 million population. Among these, Brazilians had the largest excretion rates with estrone (E1) and 17β-estradiol (E2) as 236.9 and 60 μg/day/P, respectively, while Iran had the lowest value of 2 μg/day/P for E1 and 0.5 μg/day/P for E2. The average estimated human excretion rates of E1, E2, and estriol (E3) are 17.3, 6.4, and 39.7 μg/day/P, respectively. When the estimated human excretion rates obtained were applied for prediction, the predicted results showed better accuracies than those based on human urinary/feces excretion rates. The method in this study is simple, cost-effective and time-saving, which may be widely applied. PMID:25801372

  2. Progress toward a 30 percent-efficient, monolithic, three-junction, two-terminal concentrator solar cell for space applications

    NASA Technical Reports Server (NTRS)

    Partain, L. D.; Chung, B.-C.; Virshup, G. F.; Schultz, J. C.; Macmillan, H. F.; Ristow, M. Ladle; Kuryla, M. S.; Bertness, K. A.

    1991-01-01

    Component efficiencies of 0.2/sq cm cells at approximately 100x AMO light concentration and 80 C temperatures are not at 15.3 percent for a 1.9 eV AlGaAs top cell, 9.9 percent for a 1.4 eV GaAs middle cell under a 1.9 eV AlGaAs filter, and 2.4 percent for a bottom 1.0 eV InGaAs cell under a GaAs substrate. The goal is to continue improvement in these performance levels and to sequentially grow these devices on a single substrate to give 30 percent efficient, monolithic, two-terminal, three-junction space concentrator cells. The broad objective is a 30 percent efficient monolithic two-terminal cell that can operate under 25 to 100x AMO light concentrations and at 75 to 100 C cell temperatures. Detailed modeling predicts that this requires three junctions. Two options are being pursued, and both use a 1.9 eV AlGaAs top junction and a 1.4 eV GaAs middle junction grown by a 1 atm OMVPE on a lattice matched substrate. Option 1 uses a low-doped GaAs substrate with a lattice mismatched 1.0 eV InGaAs cell formed on the back of the substrate. Option 2 uses a Ge substrate to which the AlGaAs and GaAs top junctions are lattice matched, with a bottom 0.7 eV Ge junction formed near the substrate interface with the GaAs growth. The projected efficiency contributions are near 16, 11, and 3 percent, respectively, from the top, middle, and bottom junctions.

  3. Experimental measurements of the SP response to concentration and temperature gradients in sandstones with application to subsurface geophysical monitoring

    NASA Astrophysics Data System (ADS)

    Leinov, E.; Jackson, M. D.

    2014-09-01

    Exclusion-diffusion potentials arising from temperature gradients are widely neglected in self-potential (SP) surveys, despite the ubiquitous presence of temperature gradients in subsurface settings such as volcanoes and hot springs, geothermal fields, and oil reservoirs during production via water or steam injection. Likewise, with the exception of borehole SP logging, exclusion-diffusion potentials arising from concentration gradients are also neglected or, at best, it is assumed that the diffusion potential dominates. To better interpret these SP sources requires well-constrained measurements of the various coupling terms. We report measurements of thermoelectric and electrochemical exclusion-diffusion potentials across sandstones saturated with NaCl brine and find that electrode effects can dominate the measured voltage. After correcting for these, we find that Hittorf transport numbers are the same within experimental error regardless of whether ion transport occurs in response to temperature or concentration gradients over the range of NaCl concentration investigated that is typical of natural systems. Diffusion potentials dominate only if the pore throat radius is more than approximately 4000 times larger than the diffuse layer thickness. In fine-grained sandstones with small pore throat diameter, this condition is likely to be met only if the saturating brine is of relatively high salinity; thus, in many cases of interest to earth scientists, exclusion-diffusion potentials will comprise significant contributions from both ionic diffusion through, and ionic exclusion from, the pore space of the rock. However, in coarse-grained sandstones, or sandstones saturated with high-salinity brine, exclusion-diffusion potentials can be described using end-member models in which ionic exclusion is neglected. Exclusion-diffusion potentials in sandstones depend upon pore size and salinity in a complex way: they may be positive, negative, or zero depending upon sandstone

  4. The Concentration of (236)Pu Daughters in Plutonium for Application to MOX Production from Plutonium from Dismantled US Nuclear Weapons

    SciTech Connect

    Sampson, T.E.; Cremers, T.L.

    2001-05-01

    The isotope {sup 236}Pu in the weapons-grade plutonium to be used in the US MOX (mixed-oxide) plant is of concern because the daughter products of {sup 236}Pu are sources of high-energy gamma rays. The {sup 208}Tl daughter of {sup 236}Pu emits intense, high-energy gamma rays that are important for radiation exposure calculations for plant design. It is generally thought that the concentrations of {sup 236}Pu and its daughters are well below 10{sup {minus}10}, but these concentrations are generally below the detection limits of most analytical techniques. One technique that can be used to determine the concentration {sup 208}Tl is the direct measurement of the intensity of the {sup 208}Tl gamma rays in the gamma-ray spectrum from plutonium. Thallium-208 will be in equilibrium with {sup 228}Th, and may very well be in equilibrium with {sup 232}U for most aged plutonium samples. We have used the FRAM isotopic analysis software to analyze dozens of archived high-resolution gamma ray spectra from various samples of US and foreign plutonium. We are able to quantify the ratio of minor isotopes with measurable gamma-ray emissions to the major isotope of plutonium and hence, through the measurement of the plutonium isotopic distribution of the sample, to elemental plutonium itself. Excluding items packaged in fluoropolymer vials, all samples analyzed with {sup 240}Pu < 9% gave {sup 228}Th/Pu ratios < 3.4 e-012 and all samples of US-produced plutonium, including {sup 240}Pu values up to 16.4%, gave {sup 228}Th/Pu ratios < 9.4 e-012. None of these values is significant from a radiation dose standpoint.

  5. Spectrophotometric Method for the Determination of Two Coformulated Drugs with Highly Different Concentrations. Application on Vildagliptin and Metformin Hydrochloride

    NASA Astrophysics Data System (ADS)

    Zaazaa, H. E.; Elzanfaly, E. S.; Soudi, A. T.; Salem, M. Y.

    2016-03-01

    A new smart simple validated spectrophotometric method was developed for the determination of two drugs one of which is in a very low concentration compared to the other. The method is based on spiking and dilution then simple mathematical manipulation of the absorbance spectra. This method was applied for the determination of a binary mixture of vildagliptin and metformin hydrochloride in the ratio 50:850 in laboratory prepared mixtures containing both drugs in this ratio and in pharmaceutical dosage form with good recoveries. The developed method was validated according to ICH guidelines and can be used for routine quality control testing.

  6. Daylighting with Fluorescent Concentrators and Highly Reflective Silver-Coated Plastic Films: A New Application for New Materials

    NASA Astrophysics Data System (ADS)

    Zastrow, Armin; Wittwer, Volker

    1986-09-01

    The interest in efficient daylighting systems has grown recently, due to their potential for saving a considerable amount of electrical energy used for lighting purposes. In this paper we discuss the properties of daylighting systems based on either fluorescent planar concentrators and transparent light guiding plates or light pipes coated with highly reflective silver coated plastic films. Finally we give first results from a demonstration project, daylighting systems in the students' living quarters in Stuttgart-Hohenheim, which is supported by the Commission of the European Communities.

  7. Synthesis of DNL-6 with a high concentration of Si (4 Al) environments and its application in CO(2) separation.

    PubMed

    Su, Xiong; Tian, Peng; Fan, Dong; Xia, Qinghua; Yang, Yue; Xu, Shutao; Zhang, Lin; Zhang, Ying; Wang, Dehua; Liu, Zhongmin

    2013-05-01

    The synthesis of DNL-6 with a high concentration of Si (4 Al) environments [Si/(Si+Al+P)=0.182 mol, denoted as M-DNL-6] is demonstrated. This represents the highest reported concentration of such environments in silicoaluminophosphate (SAPO) molecular sieves. Adsorption studies show that the high Si (4 Al) content in M-DNL-6, with an increased number of Brønsted acid sites in the framework, greatly promotes the adsorption of CO(2). M-DNL-6 exhibits a large CO(2) uptake capacity of up to 6.18 mmol g(-1) at 273 K and 101 kPa, and demonstrates high ratios of CO(2)/CH(4) and CO(2)/N(2) separation. From breakthrough and cycling experiments, M-DNL-6 demonstrates the ability to completely separate CO(2) from CH(4) or N(2) with a dynamic capacity of approximately 8.0 wt % before breakthrough. Importantly, the adsorbed CO(2) is easily released from the adsorbent through a simple gas purging operation at room temperature to regain 95 % of the original adsorption capacity. These results suggest that M-DNL-6 can be used as a potential adsorbent for CO(2) capture in pressure swing adsorption processes. PMID:23606439

  8. Application of passive sampling for measuring dissolved concentrations of organic contaminants in the water column at three marine superfund sites.

    PubMed

    Burgess, Robert M; Lohmann, Rainer; Schubauer-Berigan, Joseph P; Reitsma, Pamela; Perron, Monique M; Lefkovitz, Lisa; Cantwell, Mark G

    2015-08-01

    Currently, there is an effort under way to encourage remedial project managers at contaminated sites to use passive sampling to collect freely dissolved concentrations (Cfree ) of hydrophobic organic contaminants to improve site assessments. The objective of the present study was to evaluate the use of passive sampling for measuring water column Cfree for several hydrophobic organic contaminants at 3 US Environmental Protection Agency Superfund sites. Sites investigated included New Bedford Harbor (New Bedford, MA, USA), Palos Verdes Shelf (Los Angeles, CA, USA), and Naval Station Newport (Newport, RI, USA); and the passive samplers evaluated were polyethylene, polydimethylsiloxane-coated solid-phase microextraction fibers, semipermeable membrane devices, and polyoxymethylene. In general, the different passive samplers demonstrated good agreement, with Cfree values varying by a factor of 2 to 3. Further, at New Bedford Harbor, where conventional water sample concentrations were also measured (i.e., grab samples), passive sampler-based Cfree values agreed within a factor of 2. These findings suggest that all of the samplers were experiencing and measuring similar Cfree during their respective deployments. Also, at New Bedford Harbor, a strong log-linear, correlative, and predictive relationship was found between polyethylene passive sampler accumulation and lipid-normalized blue mussel bioaccumulation of polychlorinated biphenyls (r(2)  = 0.92, p < 0.05). The present study demonstrates the utility of passive sampling for generating scientifically accurate water column Cfree values, which is critical for making informed environmental management decisions at contaminated sediment sites. PMID:26039657

  9. Application of the joint multifractal analysis for describing the influence of nitrogen dioxide on ground-level ozone concentrations

    NASA Astrophysics Data System (ADS)

    Ariza-Villaverde, Ana B.; Pavon-Dominguez, Pablo; Jimenez-Hornero, Francisco J.; Gutierrez de Rave, Eduardo

    2010-05-01

    High concentrations of ground-level ozone have a negative impact on human health and the environment. Detailed knowledge on the effects of nitrogen dioxide on the ozone seasonal pattern is convenient to prevent these undesirable effects. Thus, the joint multifractal approach has been used to complete the information provided by descriptive statistics. The joint multifractal spectra were obtained for 10-minute [O3] and [NO2] time series, recorded at Córdoba (southern Spain) in 2007, revealing the presence of two main seasonal patterns: autumn-winter and spring-summer. It could be verified that the joint multifractal spectra were convex surfaces confirming the presence of the multifractal nature in the time series. There was similitude in the shapes of the joint multifractal spectra corresponding to spring-summer months. A comparable looking was also found for the spectra of the autumn-winter months. This fact evidenced the influence of [NO2] on the [O3] seasonal pattern. According to the recorded data, the concentrations of ozone and nitrogen dioxide were negatively correlated. This circumstance was caused by the presence of high and low [O3] at low and high [NO2] values, respectively. In all the cases, the spectra exhibited a clear orientation from top left region, where high [NO2] and low [O3] values were found, to bottom right part, corresponding to low [NO2] and high [O3]. The single multifractal spectra exhibited a longer tail to the right of the maximum value for all the months indicating that there was a greater heterogeneity in the lower values in the ozone concentration time series. This heterogeneity was lower for autumn-winter months, especially for January due to the shorter lengths shown by their spectra right tails, compared to those obtained for the spring-summer season. The left tails of the spectra corresponding to the spring-summer and autumn-winter months tended to be overlapped, confirming that there was a seasonal similarity in scaling

  10. Application of acid-activated Bauxsol for wastewater treatment with high phosphate concentration: Characterization, adsorption optimization, and desorption behaviors.

    PubMed

    Ye, Jie; Cong, Xiangna; Zhang, Panyue; Zeng, Guangming; Hoffmann, Erhard; Liu, Yang; Wu, Yan; Zhang, Haibo; Fang, Wei; Hahn, Hermann H

    2016-02-01

    Acid-activated Bauxsol was applied to treat wastewater with high phosphate concentration in a batch adsorption system in this paper. The effect of acid activation on the change of Bauxsol structure was systematically investigated. The mineralogical inhomogeneity and intensity of Bauxsol decreased after acid activation, and FeCl3·2H2O and Al(OH)3 became the dominant phases of acid-activated Bauxsol adsorption. Moreover, the BET surface area and total pore volume of Bauxsol increased after acid activation. Interaction of initial solution pH and adsorption temperature on phosphate adsorption onto acid-activated Bauxsol was investigated by using response surface methodology with central composite design. The maximum phosphate adsorption capacity of 192.94 mg g(-1) was achieved with an initial solution pH of 4.19 and an adsorption temperature of 52.18 °C, which increased by 7.61 times compared with that of Bauxsol (22.40 mg g(-1)), and was higher than other adsorbents. Furthermore, the desorption studies demonstrated that the acid-activated Bauxsol was successfully regenerated with 0.5 mol L(-1) HCl solution. The adsorption capacity and desorption efficiency of acid-activated Bauxsol maintained at 80.48% and 93.02% in the fifth adsorption-desorption cycle, respectively, suggesting that the acid-activated Bauxsol could be repeatedly used in wastewater treatment with high phosphate concentration. PMID:26606195