WorldWideScience

Sample records for central receivers

  1. Central solar energy receiver

    Science.gov (United States)

    Drost, M. Kevin

    1983-01-01

    An improved tower-mounted central solar energy receiver for heating air drawn through the receiver by an induced draft fan. A number of vertically oriented, energy absorbing, fin-shaped slats are radially arranged in a number of concentric cylindrical arrays on top of the tower coaxially surrounding a pipe having air holes through which the fan draws air which is heated by the slats which receive the solar radiation from a heliostat field. A number of vertically oriented and wedge-shaped columns are radially arranged in a number of concentric cylindrical clusters surrounding the slat arrays. The columns have two mirror-reflecting sides to reflect radiation into the slat arrays and one energy absorbing side to reduce reradiation and reflection from the slat arrays.

  2. A partitioned central solar receiver

    International Nuclear Information System (INIS)

    Else of solar energy as substitute for conventional fuels at a competitive cost requires efficient conversion from solar radiation to usable forms of energy. In solar thermal or thermochemical applications, high efficiency usually re- quires high temperature and high concentration of incoming radiation. The main form of energy loss from high temperature solar central receivers is thermal emission ('re radiation'), at an effective temperature close to the maximum receiver temperature. This loss is reduced if the aperture is divided into segments, most of which are maintained at lower temperatures. A two-stage partitioned receiver demonstrating this concept is under construction at the Weizman Solar Tower. The high-temperature stage is the DIAPR (Directly Irradiated Annular Pressurized Receiver). The low-temperature stage is made of tubular cavity receivers of simpler design. Preliminary optical and thermal design of the partitioned receiver is presented. For the design exit temperature of 1500 K, the aperture size of the partitioned receiver is about 60% of the equivalent single-stage receiver, indicating a significant increase of conversion efficiency. The exit temperature of the low-temperature stage is around 1100 K, allowing simpler design and inexpensive construction. (authors)

  3. Central solar-energy receiver

    Science.gov (United States)

    Not Available

    1981-10-27

    An improved tower-mounted central solar energy receiver for heating air drawn through the receiver by an induced draft fan is described. A number of vertically oriented, energy absorbing, fin-shaped slats are radially arranged in a number of concentric cylindrical arrays on top of the tower coaxially surrounding a pipe having air holes through which the fan draws air which is heated by the slats which receive the solar radiation from a heliostat field. A number of vertically oriented and wedge-shaped columns are radially arranged in a number of concentric cylindrical clusters surrounding the slat arrays. The columns have two mirror-reflecting sides to reflect radiation into the slat arrays and one energy absorbing side to reduce reradiation and reflection from the slat arrays.

  4. A handbook for solar central receiver design

    Energy Technology Data Exchange (ETDEWEB)

    Falcone, P.K.

    1986-12-01

    This Handbook describes central receiver technology for solar thermal power plants. It contains a description and assessment of the major components in a central receiver system configured for utility scale production of electricity using Rankine-cycle steam turbines. It also describes procedures to size and optimize a plant and discussed examples from recent system analyses. Information concerning site selection criteria, cost estimation, construction, and operation and maintenance is also included, which should enable readers to perform design analyses for specific applications.

  5. Second-generation central receiver technology comparison

    Science.gov (United States)

    Klimas, P. C.; Becker, M.

    Fifteen years of solar thermal technology development have produced a considerable amount of knowledge relating to the production of electricity from central receiver power plants. This body of knowledge is under examination by researchers from the United States and the Federal Republic of Germany for the purpose of defining the next generation central receiver electricity producers. This second generation power plant is expected to represent a significant step towards commercialization of these systems. During the course of the study, specific activities needed to realize this next-step technology are being defined. The study is an international team effort. Under the International Energy Agency Small Solar Power Systems project, researchers from DLR, Interatom, Sandia National Laboratories, and Bechtel have designed a study in which technologies relating to existing systems are quantified, logical next-step systems are characterized, and future potential advances are identified. The receiver concepts under investigation are: salt-in-tube, volumetric, and direct absorption. Two plant performance levels are examined, 30 and 100 MW(sub e). Each concept is applied with common capacity factors, solar multiples, and types and sizes of heliostats at each performance level. Availability and uncertainty analyses are also performed. Annual energy production figures are calculated using the SOLERGY computer code. Capital and Operation and Maintenance cost methodologies are mutually agreed upon in order that levelized energy cost calculations will be consistent for each power plant. During the course of this effort, further potential advances in central receiver technology have continued to become apparent. These possible areas for improvement will be described. An additional comparison is being made between central receivers and trough-based systems.

  6. Solar central receiver heliostat reflector assembly

    Science.gov (United States)

    Horton, Richard H.; Zdeb, John J.

    1980-01-01

    A heliostat reflector assembly for a solar central receiver system comprises a light-weight, readily assemblable frame which supports a sheet of stretchable reflective material and includes mechanism for selectively applying tension to and positioning the sheet to stretch it to optical flatness. The frame is mounted on and supported by a pipe pedestal assembly that, in turn, is installed in the ground. The frame is controllably driven in a predetermined way by a light-weight drive system so as to be angularly adjustable in both elevation and azimuth to track the sun and efficiently continuously reflect the sun's rays to a focal zone, i.e. central receiver, which forms part of a solar energy utilization system, such as a solar energy fueled electrical power generation system. The frame may include a built-in system for testing for optical flatness of the reflector. The preferable geometric configuration of the reflector is octagonal; however, it may be other shapes, such as hexagonal, pentagonal or square. Several different embodiments of means for tensioning and positioning the reflector to achieve optical flatness are disclosed. The reflector assembly is based on the stretch frame concept which provides an extremely light-weight, simple, low-cost reflector assembly that may be driven for positioning and tracking by a light-weight, inexpensive drive system.

  7. Transient simulation of molten salt central receiver

    Science.gov (United States)

    Doupis, Dimitri; Wang, Chuan; Carcorze-Soto, Jorge; Chen, Yen-Ming; Maggi, Andrea; Losito, Matteo; Clark, Michael

    2016-05-01

    Alstom is developing concentrated solar power (CSP) utilizing 60/40wt% NaNO3-KNO3 molten salt as the working fluid in a tower receiver for the global renewable energy market. In the CSP power generation cycle, receivers undergo a daily cyclic operation due to the transient nature of solar energy. Development of robust and efficient start-up and shut-down procedures is critical to avoiding component failures due to mechanical fatigue resulting from thermal transients, thus maintaining the performance and availability of the CSP plant. The Molten Salt Central Receiver (MSCR) is subject to thermal transients during normal daily operation, a cycle that includes warmup, filling, operation, draining, and shutdown. This paper describes a study to leverage dynamic simulation and finite element analysis (FEA) in development of start-up, shutdown, and transient operation concepts for the MSCR. The results of the FEA also verify the robustness of the MSCR design to the thermal transients anticipated during the operation of the plant.

  8. Thermal resistance model for CSP central receivers

    Science.gov (United States)

    de Meyer, O. A. J.; Dinter, F.; Govender, S.

    2016-05-01

    The receiver design and heliostat field aiming strategy play a vital role in the heat transfer efficiency of the receiver. In molten salt external receivers, the common operating temperature of the heat transfer fluid or molten salt ranges between 285°C to 565°C. The optimum output temperature of 565°C is achieved by adjusting the mass flow rate of the molten salt through the receiver. The reflected solar radiation onto the receiver contributes to the temperature rise in the molten salt by means of heat transfer. By investigating published work on molten salt external receiver operating temperatures, corresponding receiver tube surface temperatures and heat losses, a model has been developed to obtain a detailed thermographic representation of the receiver. The steady state model uses a receiver flux map as input to determine: i) heat transfer fluid mass flow rate through the receiver to obtain the desired molten salt output temperature of 565°C, ii) receiver surface temperatures iii) receiver tube temperatures iv) receiver efficiency v) pressure drop across the receiver and vi) corresponding tube strain per panel.

  9. Central receiver power plant: an environmental, ecological, and socioeconomic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Davison, M.; Grether, D.

    1977-06-01

    The technical details of the central receiver design are reviewed. Socio-economic questions are considered including: market penetration, air industrial sector model, demands on industry, employment, effluents associated with manufacture of components, strains due to intensive construction, water requirements, and land requirements. The ecological effects in the vicinity of the central receiver plant site are dealt with, with emphasis on effects on land surface, mammals, and reptiles and amphibians. Climatological considerations are reviewed including: desert types, effects of surface albedo modification, effects of aerosols, effects on evaporation rates, the heliostat canopy, effects on turbulent transfer rates, effects on the wind profile, a model of convection about a central receiver plant, and a global scenario. Drawings of heliostat and plant design are included in appendices. (MHR)

  10. Theory of cellwise optimization for solar central receiver system

    Science.gov (United States)

    Lipps, F. W.

    1985-05-01

    Cost effective optimization of the solar central receiver system is primarily concerned with the distribution of heliostats in the collector field, including the boundaries of the field. The cellwise optimization procedure determines the optimum cell usage and heliostat spacing parameters for each cell in the collector field. Spacing parameters determine the heliostat density and neighborhood structure uniformly in each cell. Consequently, the cellwise approach ignores heliostat mismatch at cell boundaries. Ignoring the cell boundary problem permits an easy solution for the optimum in terms of appropriately defined annual average data. Insolation, receiver interception, shading and blocking, cosine effects, and the cost parameters combine to control the optimum. Many trade offs are represented. Outputs include the receiver flux density distribution for design time, coefficients for an actual layout, the optimum boundary and various performance and cost estimates for the optimum field. It is also possible to optimize receiver size and tower height by a repeated application of the field optimization procedure.

  11. A 200kW central receiver CPV system

    Energy Technology Data Exchange (ETDEWEB)

    Lasich, John, E-mail: jbl@raygen.com; Thomas, Ian, E-mail: ithomas@raygen.com; Hertaeg, Wolfgang; Shirley, David; Faragher, Neil; Erenstrom, Neil; Carter, Sam; Cox, Brian; Zuo, Xinyi [Raygen Resources Pty. Ltd., 15 King Street, Blackburn, Victoria, 3130 (Australia)

    2015-09-28

    Raygen Resources has recently completed a Central Receiver CPV (CSPV) pilot plant in Central Victoria, Australia. The system is under final commissioning and initial operation is expected in late April 2015. The pilot demonstrates a full scale CSPV repeatable unit in a form that is representative of a commercial product and provides a test bed to prove out performance and reliability of the CSPV technology. Extensive testing of the system key components: dense array module, wireless solar powered heliostat and control system has been performed in the laboratory and on sun. Results from this key component testing are presented herein.

  12. A 200kW central receiver CPV system

    Science.gov (United States)

    Lasich, John; Thomas, Ian; Hertaeg, Wolfgang; Shirley, David; Faragher, Neil; Erenstrom, Neil; Carter, Sam; Cox, Brian; Zuo, Xinyi

    2015-09-01

    Raygen Resources has recently completed a Central Receiver CPV (CSPV) pilot plant in Central Victoria, Australia. The system is under final commissioning and initial operation is expected in late April 2015. The pilot demonstrates a full scale CSPV repeatable unit in a form that is representative of a commercial product and provides a test bed to prove out performance and reliability of the CSPV technology. Extensive testing of the system key components: dense array module, wireless solar powered heliostat and control system has been performed in the laboratory and on sun. Results from this key component testing are presented herein.

  13. Gaussian mixture models as flux prediction method for central receivers

    Science.gov (United States)

    Grobler, Annemarie; Gauché, Paul; Smit, Willie

    2016-05-01

    Flux prediction methods are crucial to the design and operation of central receiver systems. Current methods such as the circular and elliptical (bivariate) Gaussian prediction methods are often used in field layout design and aiming strategies. For experimental or small central receiver systems, the flux profile of a single heliostat often deviates significantly from the circular and elliptical Gaussian models. Therefore a novel method of flux prediction was developed by incorporating the fitting of Gaussian mixture models onto flux profiles produced by flux measurement or ray tracing. A method was also developed to predict the Gaussian mixture model parameters of a single heliostat for a given time using image processing. Recording the predicted parameters in a database ensures that more accurate predictions are made in a shorter time frame.

  14. Solar Central Receiver Prototype Heliostat. Volume I. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-06-01

    The objective of this project was to support the Solar Central Receiver Power Plant research, development and demonstration effort by: (1) Establishment of a heliostat design, with associated manufacturing, assembly, installation and maintenance approaches, that, in quantity production will yield significant reductions in capital and operating costs over an assumed 30 year plant lifetime as compared with existing designs; and (2) Identification of needs for near term and future research and development in heliostat concept, materials, manufacture, installation, maintenance, and other areas, where successful accomplishment and application would offer significant payoffs in the further reduction of the cost of electrical energy from solar central receiver power plants. The prototype heliostat design is presented in detail; and manufacturing, installation, and maintenance procedures described. (WHK)

  15. Solar central receiver prototype heliostat. Interim technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-04-05

    The objective of Phase I of this project is to support the Solar Central Receiver Power Plant research, development and demonstration effort by: (1) Establishment of a heliostat design, with associated manufacturing, assembly, installation and maintenance approaches, that, in quantity production will yield significant reductions in capital and operating costs over an assumed 30 year plant lifetime as compared with existing designs. (2) Identification of needs for near term and further research and development in heliostat concept, materials, manufacture, installation, maintenance, and other areas, where successful accomplishment and application would offer significant payoffs in the further reduction of the cost of electrical energy from Solar Central Receiver Power Plants. The Phase I study will define a low-cost heliostat preliminary design and the conceptual design of a heliostat manufacturing/installation plan which will result in low life cycle cost when produced and installed at high rate and large quantities for commercial Solar Central Receiver Power Plants. The study will develop the annualized life cycle cost and the performance of heliostats for a 30 year plant life, for each of three rates of continuous production and installation. The three specified rates are 25,000, 250,000, and 1,000,000 heliostats per year. The analysis of these varying production rates, requiring highly automated tooling and installation equipment concepts, will define the economies of large scale not realizable on Pilot Plant or Demonstration Plant installations. Project status is described in detail. (WHK)

  16. Heat pipe central solar receiver. Volume I. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Bienert, W. B.; Wolf, D. A.

    1979-04-01

    The objective of this project was the conceptual design of a Central Solar Receiver Gas Turbine Plant which utilizes a high temperature heat pipe receiver. Technical and economic feasibility of such a plant was to be determined and preliminary overall cost estimates obtained. The second objective was the development of the necessary heat pipe technology to meet the requirements of this receiver. A heat pipe receiver is ideally suited for heating gases to high temperatures. The heat pipes are essentially loss free thermal diffusers which accept a high solar flux and transform it to a lower flux which is compatible with heat transferred to gases. The high flux capability reduces receiver heating surface, thereby reducing receiver heat losses. An open recuperative air cycle with a turbine inlet temperature of 816/sup 0/C (1500/sup 0/F) was chosen as the baseline design. This results in peak metal temperatures of about 870/sup 0/C (1600/sup 0/F). The receiver consists of nine modular panels which form the semicircular backwall of a cavity. Gas enters the panels at the bottom and exits from the top. Each panel carries 637 liquid metal heat pipes which are mounted at right angle to the gas flow. The evaporators of the heat pipes protrude from the flux absorbing front surface of the panels, and the finned condensors traverse the gas stream. Capital cost estimates were made for a 10 MW(e) pilot plant. The total projected costs, in mid-1978 dollars, range from $1,947 to $2,002 per electrical kilowatt. On the same basis, the cost of a water/steam solar plant is approximately 50% higher.

  17. Solar-thermal central-receiver research study. Interim report

    Energy Technology Data Exchange (ETDEWEB)

    1977-02-01

    A performance analysis and economic study has been completed of a cavity-type line central receiver and single-axis parabolic cylinder focusing heliostat array for generation of steam for electrical power. A solar thermal power plant was sized to produce 100 MWe at 2:00 p.m. of winter solstice. The system concept is presented. Using the cavity once-through receiver with boiler tubes having an absorptivity of 0.9 and an emissivity of 0.7, it was calculated that total busbar cost in 1976 dollars during the year 1991 the second year at operation, will be 30.27 mills per kilowatt hour. The estimated total capital investment for the 100-MWe plant for the first year of commercial operation is $1908 per kilowatt of capacity.

  18. Conceptual design of advanced central receiver power system. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Tracey, T. R.

    1978-09-01

    The design of a 300 MWe tower focus power plant which uses molten salt heat transfer fluids and sensible heat storage is described in detail. The system consists of nine heliostat fields with 7711 heliostats in each. Four cavity receivers are located at the top of a 155-meter tower. Tasks include: (1) review and analysis of preliminary specification; (2) parametric analysis; (3) selection of preferred configuration; (4) commercial plant conceptual design; (5) assessment of commercial-sized advanced central power system; (6) development plan; (7) program plan; (8) reports and data; (9) program management; (10) safety analysis; and (11) material study and test program. (WHK)

  19. The crustal structure of south central Mongolia using receiver functions

    Science.gov (United States)

    He, Jing; Wu, Qingju; Sandvol, Eric; Ni, James; Gallegos, Andrea; Gao, Mengtan; Ulziibat, Munkhuu; Demberel, Sodnomsambuu

    2016-06-01

    The crustal thickness H and average crustal velocity ratio k (Vp/Vs) beneath south central Mongolia are investigated using the H-k stacking method based on teleseismic radial receiver functions. Our primary results reveal that the local crustal thickness varies from 38 to 46 km with an average value of 43 km. Thicker crust is found beneath the western Hentey Mountains, while thinner crust is located in the southern area of the Zuunbayan fault zone. The Bouguer gravity anomalies exhibit a strong correlation with the overall crustal thickness pattern throughout most of our study regime. Moreover, a new approach which integrates the Bouguer anomaly gradient and the receiver function-derived crustal thickness is adopted to calculate the density of the lower crust underneath central Mongolia. Fairly dense lower crust of approximately 3000 kg/m3 is found in the Middle Gobi Desert. The measured crustal Vp/Vs ratio ranges from 1.68 to 1.83 with an average value of 1.74. Low Vp/Vs ratio is found beneath the western Hentey Mountains. In general, low Vp/Vs ratios correlate well with regions of quartz-rich crust and high heat flow. High Vp/Vs ratios occur in the Middle Gobi volcanic regions and the Mesozoic Southern Gobi Basin.

  20. Comparative Performance Assessment For Central Receiver CPV Systems

    Science.gov (United States)

    Lasich, John B.; Thomas, Ian; Verlinden, Pierre J.; Lewandowski, Allan; Heartag, Wolfgang; Wright, Mark

    2011-12-01

    A Central receiver Concentrating PV (C2PV) system has the potential to be the optimum solar energy generation system for utility scale because it combines the high efficiency of CPV with the low cost of a heliostat collector. Due to the off axis nature of a heliostat central receiver concentrator a cosine efficiency loss is incurred and, unlike `normal' tracking CPV lens and dish systems, the optical performance varies with time and site latitude. To investigate the optical performance of a C2PV system a ray trace model has been developed and the performance of a representative C2PV system is modelled throughout the year and at different site latitudes. The cosine loss and latitude dependence are put into perspective by calculating the annual average optical efficiency and testing its sensitivity to variations in site latitude. These values are then used to estimate a system performance by applying efficiencies for solar cell, balance of system and operational factors. This system efficiency is finally compared to published data for `normal' tracking CPV dish and lens systems. Modelled annual average AC system efficiency for the C2PV system was calculated to be 21% at 40° latitude and 19% at 15° latitude. These annual average AC system efficiencies are shown to be similar to those reported for typical dish and lens CPV systems when they are adjusted to use a total collector area baseline.

  1. Large-scale use of solar energy with central receivers

    Science.gov (United States)

    Kreith, F.; Meyer, R. T.

    1983-12-01

    The working principles of solar central receiver power plants are outlined and applications are discussed. Heliostat arrays direct sunlight into a receiver cavity mounted on a tower, heating the working fluid in the tower to temperatures exceeding 500 C. The formulation for the image plane and the geometric concentration ratio for a heliostat field are provided, noting that commercial electric power plants will require concentration ratios of 200-1000. Automated controls consider imperfections in the mirrors, tracking errors, and seasonal insolation intensity and angular variations. Membranes may be used instead of rigid heliostat mirrors to reduce costs, while trade-offs exist between the efficiencies of cavity and exterior receivers on the tower. Sensible heat storage has proved most effective for cloudy or nighttime operations. Details of the DOE Solar One 10 MW plant, which began operation in 1982, are provided, with mention given to the 33.6 continuous hours of power generation that have been achieved. Projected costs of commercial installations are $700/kWt, and possible applications include recovering and refining oil, processing natural gas, uranium ore, and sugar cane, drying gypsum board, and manufacturing ammonia.

  2. Baseload Nitrate Salt Central Receiver Power Plant Design Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Tilley, Drake [Abengoa Solar LLC, Lakewood, CO (United States); Kelly, Bruce [Abengoa Solar LLC, Lakewood, CO (United States); Burkholder, Frank [Abengoa Solar LLC, Lakewood, CO (United States)

    2014-12-12

    The objectives of the work were to demonstrate that a 100 MWe central receiver plant, using nitrate salt as the receiver coolant, thermal storage medium, and heat transport fluid in the steam generator, can 1) operate, at full load, for 6,400 hours each year using only solar energy, and 2) satisfy the DOE levelized energy cost goal of $0.09/kWhe (real 2009 $). To achieve these objectives the work incorporated a large range of tasks relating to many different aspects of a molten salt tower plant. The first Phase of the project focused on developing a baseline design for a Molten Salt Tower and validating areas for improvement. Tasks included a market study, receiver design, heat exchanger design, preliminary heliostat design, solar field optimization, baseline system design including PFDs and P&IDs and detailed cost estimate. The baseline plant met the initial goal of less than $0.14/kWhe, and reinforced the need to reduce costs in several key areas to reach the overall $0.09/kWhe goal. The major improvements identified from Phase I were: 1) higher temperature salt to improve cycle efficiency and reduce storage requirements, 2) an improved receiver coating to increase the efficiency of the receiver, 3) a large receiver design to maximize storage and meet the baseload hours objective, and 4) lower cost heliostat field. The second Phase of the project looked at advancing the baseline tower with the identified improvements and included key prototypes. To validate increasing the standard solar salt temperature to 600 °C a dynamic test was conducted at Sandia. The results ultimately proved the hypothesis incorrect and showed high oxide production and corrosion rates. The results lead to further testing of systems to mitigate the oxide production to be able to increase the salt temperature for a commercial plant. Foster Wheeler worked on the receiver design in both Phase I and Phase II looking at both design and lowering costs utilizing commercial fossil boiler

  3. Solar Central Receiver Hybrid Power Systems sodium-cooled receiver concept. Final report. Volume III. Appendices

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-01-01

    The overall, long term objective of the Solar Central Receiver Hybrid Power System is to identify, characterize, and ultimately demonstrate the viability and cost effectiveness of solar/fossil, steam Rankine cycle, hybrid power systems that: (1) consist of a combined solar central receiver energy source and a nonsolar energy source at a single, common site, (2) may operate in the base, intermediate, and peaking capacity modes, (3) produce the rated output independent of variations in solar insolation, (4) provide a significant savings (50% or more) in fuel consumpton, and (5) produce power at the minimum possible cost in mills/kWh. It is essential that these hybrid concepts be technically feasible and economically competitive with other systems in the near to mid-term time period (1985-1990) on a commercial scale. The program objective for Phase I is to identify and conceptually characterize solar/fossil steam Rankine cycle, commercial-scale, power plant systems that are economically viable and technically feasible. This volume contains appendices to the conceptual design and systems analysis studies gien in Volume II, Books 1 and 2. (WHK)

  4. Evaluation of Veda, Inc. , central receiver solar collection system concept

    Energy Technology Data Exchange (ETDEWEB)

    Ator, J.

    1981-08-01

    The Unified Heliostat Array (UHA) is a geometrical heliostat field layout with rows of mirrors placed at various levels on terraces. The Veda Industrial Heliostat (VIH) is a toroidal segment mirror mounted on an equatorial mount. These two concepts are evaluated to assess the credibility of the optical designs and the validity of UHA and VIH performance estimates, to determine what the distinctive features embodied in UHA AND VIH concepts offer that more conventional central receiver technologies do not, and to determine where the UHA and VIH concepts might be most applicable in DOE's Solar Thermal Program. The UHA area efficiency, flux density distribution, and beam safety are evaluated, and the feasibility of using a secondary mirror and the potential for special applications are assessed. The optical design, equatorial mount, and manufacturability of the VIH are evaluated. (LEW)

  5. Central Andean crustal structure from receiver function analysis

    Science.gov (United States)

    Ryan, Jamie; Beck, Susan; Zandt, George; Wagner, Lara; Minaya, Estela; Tavera, Hernado

    2016-07-01

    The Central Andean Plateau (15°-27°S) is a high plateau in excess of 3 km elevation, associated with thickened crust along the western edge of the South America plate, in the convergent margin between the subducting Nazca plate and the Brazilian craton. We have calculated receiver functions using seismic data from a recent portable deployment of broadband seismometers in the Bolivian orocline (12°-21°S) region and combined them with waveforms from 38 other stations in the region to investigate crustal thickness and crust and mantle structures. Results from the receiver functions provide a more detailed map of crustal thickness than previously existed, and highlight mid-crustal features that match well with prior studies. The active volcanic arc and Altiplano have thick crust with Moho depths increasing from the central Altiplano (65 km) to the northern Altiplano (75 km). The Eastern Cordillera shows large along strike variations in crustal thickness. Along a densely sampled SW-NE profile through the Bolivian orocline there is a small region of thin crust beneath the high peaks of the Cordillera Real where the average elevations are near 4 km, and the Moho depth varies from 55 to 60 km, implying the crust is undercompensated by ~ 5 km. In comparison, a broader region of high elevations in the Eastern Cordillera to the southeast near ~ 20°S has a deeper Moho at ~ 65-70 km and appears close to isostatic equilibrium at the Moho. Assuming the modern-day pattern of high precipitation on the flanks of the Andean plateau has existed since the late Miocene, we suggest that climate induced exhumation can explain some of the variations in present day crustal structure across the Bolivian orocline. We also suggest that south of the orocline at ~ 20°S, the thicker and isostatically compensated crust is due to the absence of erosional exhumation and the occurrence of lithospheric delamination.

  6. Advanced Thermal Storage for Central Receivers with Supercritical Coolants

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Bruce D.

    2010-06-15

    The principal objective of the study is to determine if supercritical heat transport fluids in a central receiver power plant, in combination with ceramic thermocline storage systems, offer a reduction in levelized energy cost over a baseline nitrate salt concept. The baseline concept uses a nitrate salt receiver, two-tank (hot and cold) nitrate salt thermal storage, and a subcritical Rankine cycle. A total of 6 plant designs were analyzed, as follows: Plant Designation Receiver Fluid Thermal Storage Rankine Cycle Subcritical nitrate salt Nitrate salt Two tank nitrate salt Subcritical Supercritical nitrate salt Nitrate salt Two tank nitrate salt Supercritical Low temperature H2O Supercritical H2O Two tank nitrate salt Supercritical High temperature H2O Supercritical H2O Packed bed thermocline Supercritical Low temperature CO2 Supercritical CO2 Two tank nitrate salt Supercritical High temperature CO2 Supercritical CO2 Packed bed thermocline Supercritical Several conclusions have been drawn from the results of the study, as follows: 1) The use of supercritical H2O as the heat transport fluid in a packed bed thermocline is likely not a practical approach. The specific heat of the fluid is a strong function of the temperatures at values near 400 °C, and the temperature profile in the bed during a charging cycle is markedly different than the profile during a discharging cycle. 2) The use of supercritical CO2 as the heat transport fluid in a packed bed thermocline is judged to be technically feasible. Nonetheless, the high operating pressures for the supercritical fluid require the use of pressure vessels to contain the storage inventory. The unit cost of the two-tank nitrate salt system is approximately $24/kWht, while the unit cost of the high pressure thermocline system is nominally 10 times as high. 3) For the supercritical fluids, the outer crown temperatures of the receiver tubes are in the range of 700 to 800 °C. At temperatures of 700 °C and above

  7. Conceptual design of advanced central receiver power systems sodium-cooled receiver concept. Volume 2, Book 2. Appendices. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1979-03-01

    The appendices include: (A) design data sheets and P and I drawing for 100-MWe commercial plant design, for all-sodium storage concept; (B) design data sheets and P and I drawing for 100-MWe commercial plant design, for air-rock bed storage concept; (C) electric power generating water-steam system P and I drawing and equipment list, 100-MWe commercial plant design; (D) design data sheets and P and I drawing for 281-MWe commercial plant design; (E) steam generator system conceptual design; (F) heat losses from solar receiver surface; (G) heat transfer and pressure drop for rock bed thermal storage; (H) a comparison of alternative ways of recovering the hydraulic head from the advanced solar receiver tower; (I) central receiver tower study; (J) a comparison of mechanical and electromagnetic sodium pumps; (K) pipe routing study of sodium downcomer; and (L) sodium-cooled advanced central receiver system simulation model. (WHK)

  8. Low-profile heliostat design for solar central receiver systems

    Science.gov (United States)

    Fourakis, E.; Severson, A. M.

    1977-01-01

    Heliostat designs intended to reduce costs and the effect of adverse wind loads on the devices were developed. Included was the low-profile heliostat consisting of a stiff frame with sectional focusing reflectors coupled together to turn as a unit. The entire frame is arranged to turn angularly about a center point. The ability of the heliostat to rotate about both the vertical and horizontal axes permits a central computer control system to continuously aim the sun's reflection onto a selected target. An engineering model of the basic device was built and is being tested. Control and mirror parameters, such as roughness and need for fine aiming, are being studied. The fabrication of these prototypes is in process. The model was also designed to test mirror focusing techniques, heliostat geometry, mechanical functioning, and tracking control. The model can be easily relocated to test mirror imaging on a tower from various directions. In addition to steering and aiming studies, the tests include the effects of temperature changes, wind gusting and weathering. The results of economic studies on this heliostat are also presented.

  9. Conceptual design of advanced central receiver power systems sodium-cooled receiver concept. Volume 1. Executive summary. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1979-06-01

    The conceptual design of an advanced central receiver power system using liquid sodium as a heat transport medium has been completed by a team consisting of the Energy Systems Group (prime contractor), McDonnell Douglas, Stearns-Roger, The University of Houston, and Salt River Project. The purpose of this study was to determine the technical and economic advantages of this concept for commercial-scale power plants. This final report covers all tasks of the project. These tasks were as follows: (1) review and analysis of preliminary specification; (2) parametric analysis; (3) select commercial configuration; (4) commercial plant conceptual design; (5) assessment of commercial plant; (6) advanced central receiver power system development plan; (7) program plan; (8) reports and data; (9) program management; and (10) safety analysis. A programmatic overview of the accomplishments of this program is given. The 100-MW conceptual commercial plant, the 281-MW optimum plant, and the 10-MW pilot plant are described. (WHK)

  10. Effect of High Receiver Thermal Loss Per Unit Area on the Performance of Solar Central Receiver Systems Having Optimum Heliostat Fields and Optimum Receiver Aperture Areas.

    Science.gov (United States)

    Pitman, Charles L.

    Recent efforts in solar central receiver research have been directed toward high temperature applications. Associated with high temperature processes are greater receiver thermal losses due to reradiation and convection. This dissertation examines the performance of central receiver systems having optimum heliostate fields and receiver aperture areas as a function of receiver thermal loss per unit area of receiver aperture. The results address the problem of application optimization (loss varies) as opposed to the problem of optimization of a design for a specific application (loss fixed). A reasonable range of values for the primary independent variable L (the average reradiative and convective loss per unit area of receiver aperture) and a reasonable set of design assumptions were first established. The optimum receiver aperture area, number and spacings of heliostats, and field boundary were then determined for two tower focal heights and for each value of L. From this, the solar subsystem performance for each optimized system was calculated. Heliostat field analysis and optimization required a detailed computational analysis. A significant modification to the standard method of solving the optimization equations, effectively a decoupling of the solution process into collector and receiver subsystem parts, greatly aided the analysis. Results are presented for tower focal heights of 150 and 180 m. Values of L ranging from 0.04 to 0.50 MW m('-2) were considered, roughly corresponding to working fluid temperatures (at receiver exit) in the range of 650 to 1650 C. As L increases over this range, the receiver thermal efficiency and the receiver interception factor decrease. The optimal power level drops by almost half, and the cost per unit of energy produced increases by about 25% for the base case set of design assumptions. The resulting decrease in solar subsystem efficiency (relative to the defined annual input energy) from 0.57 to 0.35 is about 40% and is a

  11. Mathematical Modeling of a developed Central Receiver Based on Evacuated Solar Tubes

    OpenAIRE

    Ali Basil. H.; Gilani S. I.; Al-Kayiem Hussain H.

    2016-01-01

    Solar central receiver plays a considerable role in the plant output power; it is one of the most important synthesis in the solar power tower plants. Its performance directly affects the efficiency of the entire solar power generation system. In this study, a new designed receiver model based on evacuated solar tube was proposed, and the dynamic characteristics of the developed receiver were investigated. In order to optimise and evaluate the dynamic characteristics of solar power plant comp...

  12. Review of the Molten Salt Electric Experiment: A solar central receiver project

    Energy Technology Data Exchange (ETDEWEB)

    Delameter, W.R.; Bergan, N.E.

    1986-12-01

    The Molten Salt Electric Experiment was the first full solar-to-electric central receiver system to use molten nitrate salt as a primary working fluid. The experiment was built and tested at the Central Receiver Test Facility in Albuquerque, New Mexico, between 1982 and 1985. The purpose of the project was to demonstrate the technical feasibility of a molten salt central receiver system. The Molten Salt Electric Experiment was operated through a year of successful testing; system performance was measured, operating procedures and an effective receiver control algorithm were developed, and personnel from participating electrical utilities and solar industries were trained to operate the system. The testing culminated in a one-month power production campaign to measure daily performance, component reliability, and system availability. This paper discusses the major accomplishments and some of the more significant problems of the project.

  13. Solar power tower design guide: Solar thermal central receiver power systems. A source of electricity and/or process heat

    Science.gov (United States)

    Battleson, K. W.

    1981-04-01

    Preliminary evaluations of whether a solar thermal central receiver plant is technically and economically feasible and desirable, for the potential user's application are reported. The cost elements, performance, and operation of solar central receiver systems are described.

  14. Impact of Aerosols on Atmospheric Attenuation Loss in Central Receiver Systems: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, M.; Wagner, M. J.

    2011-08-01

    Atmospheric attenuation loss between the heliostat field and receiver has been recognized as a significant source of loss in Central Receiver Systems. In clear sky situations, extinction of Direct Normal Irradiance (DNI) is primarily by aerosols in the atmosphere. When aerosol loading is high close to the surface the attenuation loss between heliostat and receivers is significantly influenced by the amount of aerosols present on a particular day. This study relates measured DNI to aerosol optical depths close to the surface of the earth. The model developed in the paper uses only measured DNI to estimate the attenuation between heliostat and receiver in a central receiver system. The requirement that only a DNI measurement is available potentially makes the model a candidate for widespread use.

  15. Monte-Carlo RAY tracing simulation of a falling particle receiver in connection with a central receiver field

    Energy Technology Data Exchange (ETDEWEB)

    Alxneit, I. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The program RAY was developed to perform Monte-Carlo simulations of the flux distribution in solar reactors in connection with an arbitrary heliostat field. The code accounts for the shading of the incoming rays from the sun due to the reactor supporting tower as well as for full blocking and shading of the heliostats among themselves. A simplified falling particle reactor (FPR) was evaluated. A central receiver field was used with a total area of 311 m{sup 2} composed of 176 round, focusing heliostats. No attempt was undertaken to optimise either the geometry of the heliostat field nor the aiming strategy of the heliostats. The FPR was evaluated at two different geographic latitudes (-8.23W/47.542N; PSI and -8.23W/20.0N) and during the course of a day (May 30{sup th}). The incident power passing through the reactor aperture and the flux density distribution within the FPR was calculated. (author) 3 figs., 1 tab., 3 refs.

  16. Solar Central Receiver Prototype Heliostat. Volume II. Phase II planning (preliminary)

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-06-01

    A currently planned DOE program will develop and construct a 10 MW/sub e/ Pilot Plant to demonstrate the feasibility and operational characteristics of Solar Central Receiver Power Generation. The field of heliostats is a major element of the Solar Central Receiver Power Generation system. The primary objective of the program described is to establish and verify the manufacturability, performance, durability, and maintenance requirements of the commercial plant heliostat design. End products of the 16 month effort include: (1) design, fabrication, and test of heliostats; (2) preliminary designs of manufacturing, assembly, installation, and maintenance processes for quantity production; (3) detailed design of critical tooling or other special equipment for such processes; (4) refined cost estimates for heliostats and maintenance; and (5) an updated commercial plant heliostat preliminary design. The program management and control system is discussed. (WHK)

  17. An LQ-solution to a control problem associated with a solar thermal central receiver

    Science.gov (United States)

    Sworder, D. D.; Rogers, R. O.

    1983-10-01

    The linearized process dynamics of the steam boiler in a solar-powered central receiver change abruptly when clouds interfere with the sun's rays. The steam temperature regulator used to maintain proper exit steam conditions must control a system with variable structure and discontinuous state trajectories. This paper investigates the quadratic-optimal control of such a system, and gives the design equations for the optimal regulator.

  18. Concentrating Solar Power Central Receiver Panel Component Fabrication and Testing FINAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    McDowell, Michael W [Pratt & Whitney Rocketdyne; Miner, Kris [Pratt & Whitney Rocketdyne

    2013-03-30

    The objective of this project is to complete a design of an advanced concentrated solar panel and demonstrate the manufacturability of key components. Then confirm the operation of the key components under prototypic solar flux conditions. This work is an important step in reducing the levelized cost of energy (LCOE) from a central receiver solar power plant. The key technical risk to building larger power towers is building the larger receiver systems. Therefore, this proposed technology project includes the design of an advanced molten salt prototypic sub-scale receiver panel that can be utilized into a large receiver system. Then complete the fabrication and testing of key components of the receive design that will be used to validate the design. This project shall have a significant impact on solar thermal power plant design. Receiver panels of suitable size for utility scale plants are a key element to a solar power tower plant. Many subtle and complex manufacturing processes are involved in producing a reliable, robust receiver panel. Given the substantial size difference between receiver panels manufactured in the past and those needed for large plant designs, the manufacture and demonstration on prototype receiver panel components with representative features of a full-sized panel will be important to improving the build process for commercial success. Given the thermal flux limitations of the test facility, the panel components cannot be rendered full size. Significance changes occurred in the projects technical strategies from project initiation to the accomplishments described herein. The initial strategy was to define cost improvements for the receiver, design and build a scale prototype receiver and test, on sun, with a molten salt heat transport system. DOE had committed to constructing a molten salt heat transport loop to support receiver testing at the top of the NSTTF tower. Because of funding constraints this did not happen. A subsequent plan to

  19. Heat pipe central solar receiver. Semiannual progress report, September 1, 1976--May 31, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Bienert, W. B.; Wolf, D. A.

    1977-09-01

    It is proposed to develop a solar-to-gas heat exchanger for a Central Solar Receiver Power Plant. The concept employs heat pipes to transfer the concentrated solar flux to the gaseous working medium of a Brayton cycle conversion system. During early phases of the program, an open air cycle with recuperator and a turbine inlet temperature of 800/sup 0/C was selected as the optimum design. The predicted cycle efficiency is 33 percent and the overall solar-to-electric efficiency is 20 percent. Three potential receiver configurations were also identified during the initial phases of the program. Optimum heat pipe diameter is approximately 5 cm for all three receiver configurations, and typical lengths are 2 to 3 meters. The required number of heat pipes for a 10 MWe receiver ranges from 2000 to 8000. Heat transport requirements per pipe vary from 4 to 18 Kw. Several wick structures were developed and evaluated in subscale heat pipe tests using sodium as the working fluid. One full scale heat pipe (5 cm diameter by 183 cm long) was developed and tested with sodium as the working fluid.

  20. Solar central receiver hybrid power system. Monthly technical progress report for the month of December 1978

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-01-17

    Levelized busbar energy costs for the sodium-cooled hybrid central receiver concept using both oil and coal as a fuel were developed as a function of the plant capacity factor and as a function of the solar multiple. The fuel escalation question was reviewed in detail on the basis of past historical data, and it was concluded that the lower escalation numbers that are provided in the requirements definition document appear to be more likely to represent the real situation. Subsystem-level trade studies were continued during this reporting period. A detailed investigation of the series/parallel arrangement of the sodium heater and solar receiver was conducted. The various performance, lifetime, and cost factors were determined for each arrangement for the receiver and nonsolar subsystems, respectively. Collector subsystem studies were continued. Revised cost algorithms that include levelized O and M costs for the heliostats were generated in order that they can be used in the field optimization. On the basis of the subsystem studies and the economic assessment work, a reference configuration was tentatively derived. This configuration does not require storage and uses a parallel arrangement of the receiver and the heater. At this time, a coal-fired heater seems to have a potential economic advantage under realistic assumptions for the escalation of coal relative to oil over the next decade or so.

  1. Solar central receiver prototype heliostat CDRL item B. d. Final technical report, Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Easton, C. R.

    1978-08-01

    This is volume II of a two volume report which presents the results of a study to define a low-cost approach to the production, installation, and operation of heliostats for central receiver solar thermal power plants. Performance and cost analyses are presented, and critical R and D areas are identified. Also, computer printed work sheets are included for heliostat investment, maintenance equipment investment, initial spares investment, and first years operations and maintenance for 2,500, 25,000, 250,000, and 1,000,000 units per year production. (WHK)

  2. Combined cycle solar central receiver hybrid power system study. Final technical report. Volume II

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-11-01

    This study develops the conceptual design for a commercial-scale (nominal 100 MWe) central receiver solar/fossil fuel hybrid power system with combined cycle energy conversion. A near-term, metallic heat pipe receiver and an advanced ceramic tube receiver hybrid system are defined through parametric and market potential analyses. Comparative evaluations of the cost of power generation, the fuel displacement potential, and the technological readiness of these two systems indicate that the near-term hybrid system has better potential for commercialization by 1990. Based on the assessment of the conceptual design, major cost and performance improvements are projected for the near-term system. Constraints preventing wide-spread use were not identified. Energy storage is not required for this system and analyses show no economic advantages with energy storage provisions. It is concluded that the solar hybrid system is a cost effective alternative to conventional gas turbines and combined cycle generating plants, and has potential for intermediate-load market penetration at 15% annual fuel escalation rate. Due to their flexibility, simple solar/nonsolar interfacing, and short startup cycles, these hybrid plants have significant operating advantages. Utility company comments suggest that hybrid power systems will precede stand-alone solar plants.

  3. Line focus solar thermal central receiver research study. Final report, April 30, 1977-March 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Di Canio, D.G.; Treytl, W.J.; Jur, F.A.; Watson, C.D.

    1979-04-01

    The results of a study to examine the line focus central receiver alternative for solar thermal generation of electric power on a commercial scale are presented. The baseline concept consists of the following elements: (1) a solar collector (heliostat) whose geometry is the equivalent of a focused parabolic cylinder. The heliostat reflecting surface is composed of an array of flexible rectangular mirror panels supported along their long edges by a framework which rotates about an axis parallel to the ground plane. The mirror panels in one section (18.3 meters by 3.05 meters (60 feet by 10 feet)) are defocused in unison by a simple mechanism under computer control to achieve the required curvature. Two sections (110 meters/sup 2/(591 feet/sup 2/)) are controlled and driven in elevation by one control/drive unit. (2) A linear cavity receiver, composed of 61-meter (200-foot) sections supported by towers at an elevation of 61 meters (200 feet). Each section receives feedwater and produces turbine-rated steam. The cavity is an open cylinder 1.83 meters (6 feet) in inside diameter, with a 1.22 meter (4 foot) aperture oriented at 45 degrees to the collector field. (3) Heliostat control, consisting of a local controller at each heliostat module which communicates with a master control computer to perform elevation tracking and focal length adjustment. The control logic is open-loop, with sun position computer by the master computer with an algorithm. Image sensors, mounted above and below the receiver aperture, are used to monitor the collector field and provide feedback to the master computer for detection of misaligned heliostats. (WHK)

  4. Thermoeconomic optimization of a Kalina cycle for a central receiver concentrating solar power plant

    DEFF Research Database (Denmark)

    Modi, Anish; Kærn, Martin Ryhl; Andreasen, Jesper Graa;

    2016-01-01

    Concentrating solar power plants use a number of reflecting mirrors to focus and convert the incident solar energy to heat, and a power cycle to convert this heat into electricity. This paper evaluates the use of a high temperature Kalina cycle for a central receiver concentrating solar power plant...... with direct vapour generation and without storage. The use of the ammonia-water mixture as the power cycle working fluid with non-isothermal evaporation and condensation presents the potential to improve the overall performance of the plant. This however comes at a price of requiring larger heat exchangers...... and the economic perspectives, the results suggest that it is not beneficial to use the Kalina cycle for high temperature concentrating solar power plants....

  5. Dynamic instabilities in radiation-heated boiler tubes for solar central receivers

    Science.gov (United States)

    Wolf, S.; Chan, K. C.; Chen, K.; Yadigaroglu, G.

    1982-11-01

    Density-wave instabilities have been investigated in circumferentially nonuniform radiation-heated boiler tubes, simulating solar heating. Analysis and experimental data are presented. The analysis provides the basis for a computer code, STEAMFREQ-I, for the prediction of density-wave instabilities in boiler tubes with imposed heat flux. The key model features include a drift-flux flow model in the boiling region, spatial variation of heat flux, wall dynamics, and variable steam properties in the superheat region. The experimental data include results from two radiation heated boiler panel tests. The data are applicable to central receivers for solar electric power plants. Data for stable and unstable conditions are compared with predictions from STEAMFREQ-I.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Tri-Lateral Noor al Salaam High Concentration Solar Central Receiver Program

    Energy Technology Data Exchange (ETDEWEB)

    Blackmon, James B

    2008-03-31

    This report documents the efforts conducted primarily under the Noor al Salaam (“Light of Peace”) program under DOE GRANT NUMBER DE-FC36-02GO12030, together with relevant technical results from a closely related technology development effort, the U.S./Israel Science and Technology Foundation (USISTF) High Concentration Solar Central Receiver program. These efforts involved preliminary design, development, and test of selected prototype power production subsystems and documentation of an initial version of the system definition for a high concentration solar hybrid/gas electrical power plant to be built in Zaafarana, Egypt as a first step in planned commercialization. A major part of the planned work was halted in 2007 with an amendment in October 2007 requiring that we complete the technical effort by December 31, 2007 and provide a final report to DOE within the following 90 days. This document summarizes the work conducted. The USISTF program was a 50/50 cost-shared program supported by the Department of Commerce through the U.S./Israel Science and Technology Commission (USISTC). The USISTC was cooperatively developed by President Clinton and the late Prime Minister Rabin of Israel "to encourage technological collaboration" and "support peace in the Middle East through economic development". The program was conducted as a follow-on effort to Israel's Magnet/CONSOLAR Program, which was an advanced development effort to design, fabricate, and test a solar central receiver and secondary optics for a "beam down" central receiver concept. The status of these hardware development programs is reviewed, since they form the basis for the Noor al Salaam program. Descriptions are provided of the integrated system and the major subsystems, including the heliostat, the high temperature air receiver, the power conversion unit, tower and tower reflector, compound parabolic concentrator, and the master control system. One objective of the USISTF program was to conduct

  8. Power and Efficiency Analysis of a Solar Central Receiver Combined Cycle Plant with a Small Particle Heat Exchanger Receiver

    Science.gov (United States)

    Virgen, Matthew Miguel

    Two significant goals in solar plant operation are lower cost and higher efficiencies. To achieve those goals, a combined cycle gas turbine (CCGT) system, which uses the hot gas turbine exhaust to produce superheated steam for a bottoming Rankine cycle by way of a heat recovery steam generator (HRSG), is investigated in this work. Building off of a previous gas turbine model created at the Combustion and Solar Energy Laboratory at SDSU, here are added the HRSG and steam turbine model, which had to handle significant change in the mass flow and temperature of air exiting the gas turbine due to varying solar input. A wide range of cases were run to explore options for maximizing both power and efficiency from the proposed CSP CCGT plant. Variable guide vanes (VGVs) were found in the earlier model to be an effective tool in providing operational flexibility to address the variable nature of solar input. Combined cycle efficiencies in the range of 50% were found to result from this plant configuration. However, a combustor inlet temperature (CIT) limit leads to two distinct Modes of operation, with a sharp drop in both plant efficiency and power occurring when the air flow through the receiver exceeded the CIT limit. This drawback can be partially addressed through strategic use of the VGVs. Since system response is fully established for the relevant range of solar input and variable guide vane angles, the System Advisor Model (SAM) from NREL can be used to find what the actual expected solar input would be over the course of the day, and plan accordingly. While the SAM software is not yet equipped to model a Brayton cycle cavity receiver, appropriate approximations were made in order to produce a suitable heliostat field to fit this system. Since the SPHER uses carbon nano-particles as the solar absorbers, questions of particle longevity and how the particles might affect the flame behavior in the combustor were addressed using the chemical kinetics software Chemkin

  9. Solar Central Receiver Hybrid Power Systems sodium-cooled receiver concept. Final report. Volume II, Book 2. Conceptual design, Sections 5 and 6

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-01-01

    The overall, long-term objective of the Solar Central Receiver Hybrid Power System program is to identify, characterize, and ultimately demonstrate the viability and cost effectiveness of solar/fossil, steam Rankine cycle, hybrid power systems that: (1) consist of a combined solar central receiver energy source and a nonsolar energy source at a single, common site, (2) may operate in the base, intermediate, and peaking capacity modes, (3) produce the rated output independent of variations in solar insolation, (4) provide a significant savings (50% or more) in fuel consumption, and (5) produce power at the minimum possible cost in mills/kWh. It is essential that these hybrid concepts be technically feasible and economically competitive with other systems in the near to mid-term time period (1985-1990) on a commercial scale. The program objective for Phase I is to identify and conceptually characterize solar/fossil steam Rankine cycle, commercial-scale, power plant systems that are economically viable and technically feasible. This volume contains the detailed conceptual design and cost/performance estimates and an assessment of the commercial scale solar central receiver hybrid power system. (WHK)

  10. The design of future central receiver power plants based on lessons learned from the Solar One Pilot Plant

    Science.gov (United States)

    Kolb, G. J.

    The 10-MW(sub e) Solar One Pilot Plant was the world's largest solar central receiver power plant. During its power production years it delivered over 37,000 MWhrs (net) to the utility grid. In this type of electric power generating plant, large sun-tracking mirrors called heliostats reflect and concentrate sunlight onto a receiver mounted on top of a tower. The receiver transforms the solar energy into thermal energy that heats water, turning it into superheated steam that drives a turbine to generate electricity. The Solar One Pilot Plant successfully demonstrated the feasibility of generating electricity with a solar central receiver power plant. During the initial 2 years the plant was tested and 4 years the plant was operated as a power plant, a great deal of data was collected relating to the efficiency and reliability of the plant's various systems. This paper summarizes these statistics and compares them to goals developed by the U.S. Department of Energy. Based on this comparison, improvements in the design and operation of future central receiver plants are recommended. Research at Sandia National Laboratories and the U.S. utility industry suggests that the next generation of central receiver power plants will use a molten salt heat transfer fluid rather than water/steam. Sandia has recently completed the development of the hardware needed in a molten salt power plant. Use of this new technology is expected to solve many of the performance problems encountered at Solar One. Projections for the energy costs from these future central receiver plants are also presented. For reference, these projections are compared to the current energy costs from the SEGS parabolic trough plants now operating in Southern California.

  11. Transient analysis of a molten salt central receiver (MSCR) in a solar power plant

    Science.gov (United States)

    Joshi, A.; Wang, C.; Akinjiola, O.; Lou, X.; Neuschaefer, C.; Quinn, J.

    2016-05-01

    Alstom is developing solar power tower plants utilizing molten salt as the working fluid. In solar power tower, the molten salt central receiver (MSCR) atop of the tower is constructed of banks of tubes arranged in panels creating a heat transfer surface exposed to the solar irradiation from the heliostat field. The molten salt heat transfer fluid (HTF), in this case 60/40%wt NaNO3-KNO3, flows in serpentine flow through the surface collecting sensible heat thus raising the HTF temperature from 290°C to 565°C. The hot molten salt is stored and dispatched to produce superheated steam in a steam generator, which in turn produces electricity in the steam turbine generator. The MSCR based power plant with a thermal energy storage system (TESS) is a fully dispatchable renewable power plant with a number of opportunities for operational and economic optimization. This paper presents operation and controls challenges to the MSCR and the overall power plant, and the use of dynamic model computer simulation based transient analyses applied to molten salt based solar thermal power plant. This study presents the evaluation of the current MSCR design, using a dynamic model, with emphasis on severe events affecting critical process response, such as MS temperature deviations, and recommend MSCR control design improvements based on the results. Cloud events are the scope of the transient analysis presented in this paper. The paper presents results from a comparative study to examine impacts or effects on key process variables related to controls and operation of the MSCR plant.

  12. Evaluation of the variability of wind speed at different heights and its impact on the receiver efficiency of central receiver systems

    Science.gov (United States)

    Delgado, A.; Gertig, C.; Blesa, E.; Loza, A.; Hidalgo, C.; Ron, R.

    2016-05-01

    Typical plant configurations for Central Receiver Systems (CRS) are comprised of a large field of heliostats which concentrate solar irradiation onto the receiver, which is elevated hundreds of meters above the ground. Wind speed changes with altitude above ground, impacting on the receiver thermal efficiency due to variations of the convective heat losses. In addition, the physical properties of air vary at high altitudes to a significant degree, which should be considered in the thermal losses calculation. DNV GL has long-reaching experience in wind energy assessment with reliable methodologies to reduce the uncertainty of the determination of the wind regime. As a part of this study, DNV GL estimates the wind speed at high altitude for different sites using two methods, a detailed estimation applying the best practices used in the wind energy sector based on measurements from various wind sensors and a simplified estimation applying the power law (1, 2) using only one wind measurement and a representative value for the surface roughness. As a result of the study, a comparison of the wind speed estimation considering both methods is presented and the impact on the receiver performance for the evaluated case is estimated.

  13. Conceptual design of advanced central receiver power systems sodium-cooled receiver concept. Volume 4. Commercial and pilot plant cost data. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1979-03-01

    This volume of the advanced central receiver final report presents the cost data using the cost breakdown structure identified in the preliminary specification. Cost summaries are presented in the following sections for the 100-MWe and 281-MWe commercial plant and a 10-MWe pilot plant. Cost substantiation data for this volume are presented in the appendices. Other cost summary data include Nth plant data for the 100-MWe and 281-MWe commercial plants, and a summary for the alternative concept air-rock storage system. The main description of the plant costing technique occurs as part of Section II for the 100-MWe baseline concept.

  14. Solar Central Receiver Hybrid Power Systems sodium-cooled receiver concept. Final report. Volume II, Book 1. Conceptual design, Sections 1 through 4

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-01-01

    The overall, long-term objective of the Solar Central Receiver Hybrid Power System program is to identify, characterize, and ultimately demonstrate the viability and cost effectiveness of solar/fossil, steam Rankine cycle, hybrid power systems that: (1) consist of a combined solar central receiver energy source and a nonsolar energy source at a single, common site, (2) may operate in the base, intermediate, and peaking capacity modes, (3) produce the rated output independent of variations in solar insolation, (4) provide a significant savings (50% or more) in fuel consumption, and (5) produce power at the minimum possible cost in mills/kWh. It is essential that these hybrid concepts be technically feasible and economically competitive with other systems in the near to mid-term time period (1985-1990) on a commercial scale. The program objective for Phase I is to identify and conceptually characterize solar/fossil steam Rankine cycle, commercial-scale, power plant systems that are economically viable and technically feasible. This volume presents in detail the market analysis, parametric analysis, and the selection process for the preferred system. (WHK)

  15. Central receiver solar thermal power system, phase 1. Progress report for period ending December 31, 1975

    Energy Technology Data Exchange (ETDEWEB)

    None

    1976-04-01

    The program objective is the preliminary design of a 10 MWe pilot solar power plant supported by major subsystem experiments. Progress is reported on the following task elements: 10 MWe pilot plant; collector subsystem design and analysis; receiver subsystem requirements; receiver subsystem design; thermal storage subsystem; electrical power generation subsystem; and pilot plant architectural engineering and support. (WDM)

  16. Effects of vertically ribbed surface roughness on the forced convective heat losses in central receiver systems

    Science.gov (United States)

    Uhlig, Ralf; Frantz, Cathy; Fritsch, Andreas

    2016-05-01

    External receiver configurations are directly exposed to ambient wind. Therefore, a precise determination of the convective losses is a key factor in the prediction and evaluation of the efficiency of the solar absorbers. Based on several studies, the forced convective losses of external receivers are modeled using correlations for a roughened cylinder in a cross-flow of air. However at high wind velocities, the thermal efficiency measured during the Solar Two experiment was considerably lower than the efficiency predicted by these correlations. A detailed review of the available literature on the convective losses of external receivers has been made. Three CFD models of different level of detail have been developed to analyze the influence of the actual shape of the receiver and tower configuration, of the receiver shape and of the absorber panels on the forced convective heat transfer coefficients. The heat transfer coefficients deduced from the correlations have been compared to the results of the CFD simulations. In a final step the influence of both modeling approaches on the thermal efficiency of an external tubular receiver has been studied in a thermal FE model of the Solar Two receiver.

  17. Central Receiver Solar Thermal Power System, Phase 1. CDRL Item 2. Pilot Plant preliminary design report. Volume III, Book 1. Collector subsystem

    Energy Technology Data Exchange (ETDEWEB)

    Hallet, Jr., R. W.; Gervais, R. L.

    1977-10-01

    The central receiver system consists of a field of heliostats, a central receiver, a thermal storage unit, an electrical power generation system, and balance of plant. This volume discusses the collector field geometry, requirements and configuration. The development of the collector system and subsystems are discussed and the selection rationale outlined. System safety and availability are covered. Finally, the plans for collector portion of the central receiver system are reviewed.

  18. Optimisation of a Kalina cycle for a central receiver solar thermal power plant with direct steam generation

    DEFF Research Database (Denmark)

    Modi, Anish; Haglind, Fredrik

    2014-01-01

    Central receiver solar thermal power plants are regarded as one of the promising ways to generate electricity in near future. They offer the possibility of using high temperatures and pressures to achieve high efficiencies with standard power cycles. A direct steam generation approach can be used...... for such plants for improved performance. This approach can also be combined with using advanced power cycles like the Kalina cycle, which uses a zeotropic mixture of ammonia and water instead of pure water as the working fluid. This paper presents the optimisation of a particular Kalina cycle layout...... for a central receiver solar thermal power plant with direct steam generation. The variation in the cycle performance with respect to the turbine inlet ammonia mass fraction and pressure and a comparison of the initial investment with that of the basic Rankine cycle are also presented. Only high live steam...

  19. Occurrence of pharmaceuticals in municipal wastewater treatment plants and receiving surface waters in Central and Southern Finland

    OpenAIRE

    Lindholm-Lehto, Petra

    2016-01-01

    The presence of five selected pharmaceuticals, four anti-inflammatory drugs, diclofenac, ibuprofen, ketoprofen, naproxen, and an antiepileptic drug carbamazepine, was determined at four municipal wastewater treatment plants (WWTPs) and in the receiving waterway near the city of Jyväskylä, in central Finland and also in the River Vantaa. First, an analytical method was developed including a pretreatment and purification followed by liquid chromatography coupled to tandem mass spectrometry (LC-...

  20. Direct Heat-Flux Measurement System (MDF) for Solar central Receiver Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Ballestrin, J.

    2001-07-01

    A direct flux measurement system, MDF, has been designed, constructed and mounted on top of the SSPS-CRS tower at the Plataforma Solar de Almeria (PSA) in addition to an indirect flux measurement system based on a CCD camera. It's one of the main future objectives to compare systematically both measurements of the concentrated solar power, increasing in this way the confidence in the estimate of this quantity. Today everything is prepared to perform the direct flux measurement on the aperture of solar receivers: calorimeter array, data acquisition system and software. the geometry of the receiver determines the operation and analysis procedures to obtain the indecent power onto the defined area. The study of previous experiences with direct flux measurement systems ha been useful to define a new simpler and more accurate system. A description of each component of the MDF system is included, focusing on the heat-flux sensors or calorimeters, which enables these measurements to be done in a few seconds without water-cooling. The incident solar power and the spatial flux distribution on the aperture of the volumetric receiver Hitrec II are supplied by the above-mentioned MDF system. The first results obtained during the evaluation of this solar receiver are presented including a sunrise-sunset test. All these measurements have been concentrated in one coefficient that describes the global behavior of the Solar Power Plant. (Author) 18 refs.

  1. Direct Heat-Flux Measurement System (MDF) for Solar Central Receiver Evaluation

    International Nuclear Information System (INIS)

    A direct flux measurement system, MDF, has been designed, constructed and mounted on top of the SSPSCRS tower at the Plataforma Solar de Almeria (PSA) in addition to an indirect flux measurement system based on a CCD camera. It's one of the main future objectives to compare systematically both measurements of the concentrated solar power, increasing in this way the confidence in the estimate of this quantity. Today everything is prepared to perform the direct flux measurement on the aperture of solar receivers: calorimeter array, data acquisition system and software. The geometry of the receiver determines the operation and analysis procedures to obtain the incident power onto the defined area. The study of previous experiences with direct flux measurement systems has been useful to define a new, simpler and more accurate system. A description of each component of the MDF system is included, focusing on the heat-flux sensors or calorimeters, which enables these measurements to be done in a few seconds without water-cooling. The incident solar power and the spatial flux distribution on the aperture of the volumetric receiver Hitrec II are supplied by the above-mentioned MDF system. The first results obtained during the evaluation of this solar receiver are presented including a sunrise-sunset test. AU these measurements have been concentrated in one coefficient that describes the global behavior of the Solar Power Plant. (Author) 18 refs

  2. Comparison of intelligence quotient in children surviving leukemia who received different prophylactic central nervous system treatments

    OpenAIRE

    Reisi Nahid; Khalilian Leila

    2012-01-01

    Background: Neurocognitive deficits and decrease in intelligence quotient (IQ) is one of the complication of prophylactic central nervous system (CNS) treatment in acute lymphoblastic leukemia (ALL) patients. In this study, we compare the IQ in survivors of ALL that were treated with different prophylactic CNS treatments. Materials and Methods : We compared 43 long-term survivors of ALL: 21 survivors with intrathecal methotrexate (IT MTX) as CNS prophylaxis, 22 with IT MTX+1800-2400 rads c...

  3. Evaluation of annual efficiencies of high temperature central receiver concentrated solar power plants with thermal energy storage.

    Energy Technology Data Exchange (ETDEWEB)

    Ehrhart, Brian David; Gill, David Dennis

    2013-07-01

    The current study has examined four cases of a central receiver concentrated solar power plant with thermal energy storage using the DELSOL and SOLERGY computer codes. The current state-of-the-art base case was compared with a theoretical high temperature case which was based on the scaling of some input parameters and the estimation of other parameters based on performance targets from the Department of Energy SunShot Initiative. This comparison was done for both current and high temperature cases in two configurations: a surround field with an external cylindrical receiver and a north field with a single cavity receiver. There is a fairly dramatic difference between the design point and annual average performance, especially in the solar field and receiver subsystems, and also in energy losses due to the thermal energy storage being full to capacity. Additionally, there are relatively small differences (<2%) in annual average efficiencies between the Base and High Temperature cases, despite an increase in thermal to electric conversion efficiency of over 8%. This is due the increased thermal losses at higher temperature and operational losses due to subsystem start-up and shut-down. Thermal energy storage can mitigate some of these losses by utilizing larger thermal energy storage to ensure that the electric power production system does not need to stop and re-start as often, but solar energy is inherently transient. Economic and cost considerations were not considered here, but will have a significant impact on solar thermal electric power production strategy and sizing.

  4. Central receiver solar thermal power system, Phase 1. Quarterly progress report (final) for period ending March 31, 1976

    Energy Technology Data Exchange (ETDEWEB)

    None

    1976-10-01

    During this period (January 1976 through March 1976), the primary program effort was expended toward the completion of the detail design of the three major research experiments. Also, the Preliminary Pilot Plant Economic Cost Study was completed. In the Collector Subsystem, the designs for both the twenty-five mirror and the nine-mirror heliostats were completed and released. In the Receiver Subsystem, Foster Wheeler continued with the detail design of the 5 MW research experiment receiver. A preliminary draft of the detailed test plan for the receiver subsystem research experiment was prepared and is now undergoing a final review. The detailed design of the Thermal Storage Subsystem continued at Georgia Institute of Technology. Several incremental detail design reviews were held as the design progressed. During this period, Bechtel completed the preliminary environmental analysis for the Pilot Plant. The optimization studies of the electrical power generation subsystem were initiated. A major effort was the preparation of the preliminary cost analysis for the 10 MWe Central Receiver Solar Thermal Pilot Plant. This task required the development of a cost accounting structure and a definition of all of the costs associated with the design, construction, checkout, and two-year test of the Pilot Plant. (WDM)

  5. Optical design of a 4-off-axis-unit Cassegrain ultra-high concentrator photovoltaics module with a central receiver.

    Science.gov (United States)

    Ferrer-Rodríguez, Juan P; Fernández, Eduardo F; Almonacid, Florencia; Pérez-Higueras, Pedro

    2016-05-01

    Ultra-high concentrator photovoltaics (UHCPV), with concentrations higher than 1000 suns, have been pointed out by different authors as having great potential for being a cost-effective PV technology. This Letter presents a UHCPV Cassegrain-based optical design in which the sunrays are concentrated and sent from four different and independent paraboloid-hyperboloid pairs optical units onto a single central receiver. The optical design proposed has the main advantage of the achievement of ultra-high concentration ratios using relative small mirrors with similar performance values of efficiency, acceptance angle, and irradiance uniformity to other designs.

  6. Solar central receiver prototype heliostat: phase 1. Final technical report, September 30, 1977-June 24, 1978

    Energy Technology Data Exchange (ETDEWEB)

    1978-10-01

    The complete preliminary design analysis and drawings of the heliostat system that were used as the basis for the manufacturing conceptual design and cost estimates are presented. Complete costing data is included along with all of the assumptions and data used in studying the production processes. A detailed description of the control system design is given together with a full report on the breadboard testing of the linear motor drives and the self-calibrating control system. Specifications and a conceptual design of the Automatic Foundation Machine are provided as well as a complete description of the installation process and its labor and time estimates. The enclosed heliostat consists of an aluminized film reflector which is deployed on a lightweight, eight-strut frame mounted on a single pipe pedestal with azimuth and elevation drives and totally housed in an air supported enclosure. An open loop control system with self calibration capability directs centrally computed sun angles and steering commands to individual heliostats of a total system via 2-way multiplex methods over the field power distribution network. Totally mass-produced in conventional industrial factories, the preassembled components are shipped without restriction and are semi-automatically installed within 30-minute time cycles. Requiring no cleaning, the 30-year life cycle maintenance costs include two complete enclosure and reflector replacements. (WHK)

  7. Receiver subsystem analysis report (RADL Item 4-1). The 10-MWe solar thermal central-receiver pilot plant: Solar-facilities design integration

    Science.gov (United States)

    1982-04-01

    The results of thermal hydraulic, design for the stress analyses which are required to demonstrate that the receiver design for the Barstow Solar Pilot Plant satisfies the general design and performance requirements during the plant's design life are presented. Recommendations are made for receiver operation. The analyses are limited to receiver subsystem major structural parts (primary tower, receiver unit core support structure), pressure parts (absorber panels, feedwater, condensate and steam piping/components, flash tank, and steam mainfold) and shielding.

  8. Numerical study of local/regional atmospheric changes caused by a large solar central receiver power plant

    Science.gov (United States)

    Bhumralkar, C. M.; Slemmons, A. J.; Nitz, K. C.

    1981-06-01

    A two-dimensional numerical atmospheric mesoscale model with a vertical cross section is applied to study the potential local/regional atmospheric effects of the installation of a 100 MWe solar thermal central receiver power plant in California. The plant comprises heliostats (mirrors) covering a portion of ground surface and reflecting sunlight onto a central receiving tower. The model is able to simulate the changes in surface characteristics associated with the installation of heliostats and other power plant ancillaries and can also simulate the effects of waste heat from cooling towers. The model equations are integrated to simulate typical summer and atypical summer. The results for typical summer conditions at the site and in the surrounding region demonstrate that the power plant has the potential to increase local humidity and wind circulation but cannot induce the formation of clouds or rain. The results for atypical summer conditions show that the solar power plant is potentially able to increase the wind circulation and form clouds and rain. It is noted, however, that the life cycle of such formations is only 2-3 h.

  9. Direct contrast enhanced Venography MR in the study of central venous accesses in children receiving total parenteral nutrition

    International Nuclear Information System (INIS)

    Purpose. To present direct contrast enhanced Magnetic Resonance Venography, a recently developed method for the study of central venous accesses. Materials and methods. Six patients (4 males and 2 females; age range 15-18 Years) with severe intestinal failure treated with indwelling central Venous catheter since childhood were studied by MR-angiography. The examination was carried out with a 1.5 Philips Gyroscan Intera Magnet, sequences during the simultaneous injection of about 60 ml/limb paramagnetic contrast material, Gd DTPA, diluted with saline solution at a ratio of 1:12. The images were processed with maximum intensity coronal projections and compared with the phlebographic images obtained earlier. Results. In 4 cases the method demonstrated superior vena cava occlusion, in 2 cases inferior vena cava occlusion. The examination was well tolerated by all patients and image quality was very similar to that of the gold standard Study, conventional phlebography. Conclusions. We believe direct contrast-enhanced MR-venography to be a minimally invasive, panoramic and diagnostically reliable method, which should be considered the first choice in the study of central venous accesses of patients receiving total parental nutrition for the medical treatment of intestinal failure. The method does not expose the patients to ionizing radiation or require iodinated contrast material, and is relatively short with a room lime of about 30-40 minutes

  10. Receiver subsystem analysis report (RADL Item 4-1). 10-MWe Solar Thermal Central-Receiver Pilot Plant: solar-facilities design integration

    Energy Technology Data Exchange (ETDEWEB)

    1982-04-01

    The results are presented of those thermal hydraulic, structural, and stress analyses required to demonstrate that the Receiver design for the Barstow Solar Pilot Plant will satisfy the general design and performance requirements during the plant's design life. Recommendations resulting from those analyses and supporting test programs are presented regarding operation of the receiver. The analyses are limited to receiver subsystem major structural parts (primary tower, receiver unit core support structure), pressure parts (absorber panels, feedwater, condensate and steam piping/components, flash tank, and steam mainfold) and shielding. (LEW)

  11. Reflectance measurement in heliostats field of Solar Thermal Central Receivers Systems; Medida de reflectancia en campos de heliostatos de sistemas de Torre Central

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Reche, J.; Monterreal, R.

    2004-07-01

    Determination of the mean reflectance of Heliostats field of Solar Thermal Central Receivers Systems takes high relevance, from both the operational point of view and the components evaluation. To calculate the mean reflectance calculation becomes essential to establish a procedure that allows offering its value without measuring all and each one of the facets that constitute the field, since this is a long-time consuming and little operational task. This work presents the results of the statistical reflectance study of the CRS heliostats field of the Plataforma Solar de Almeria. In addition, to validate the results, the obtained average reflectance is introduced in the heliostats field simulation code Fiat{sub L}ux. A comparison between the simulation and real incident solar power measurement was performed. (Author)

  12. Simulation of an EPRI-Nevada Test Site (NTS) hydrogen burn test at the Central Receiver Test Facility

    International Nuclear Information System (INIS)

    In order to augment results obtained from the hydrogen burn equipment survival tests performed by the Electric Power Research Institute (EPRI) at the Nevada Test Site (NTS), a series of tests was conducted at the Sandia National Laboratories Central Receiver Test Facility (CRTF). The CRTF tests simulated a 13 volume-percent burn from the EPRI-NTS series. During the CRTF tests, the thermal and operational responses of several specimens of nuclear power plant safety-related equipment were monitored when subjected to a solar heat flux simulation of a hydrogen burn. The simulation was conducted with and without steam in the vicinity of the test specimens. Prior to exposure, the specimens were preheated to temperatures corresponding to the precombustion environment in the EPRI-NTS test vessel

  13. Solar central receiver hybrid power system, Phase I. Volume 2. Conceptual design. Final technical report, October 1978-August 1979

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-09-01

    The objectives of this study were to develop a hybrid power system design that (1) produces minimum cost electric power, (2) minimizes the capital investment and operating cost, (3) permits capacity displacement, (4) and achieves utility acceptance for market penetration. We have met the first three of these objectives and therefore believe that the fourth, utility acceptance, will become a reality. These objectives have been met by utilizing the Martin Marietta concept that combines the alternate central receiver power system design and a high-temperature salt primary heat transfer fluid and thermal storage media system with a fossil-fired nonsolar energy source. Task 1 reviewed the requirements definition document and comments and recommendations were provided to DOE/San Francisco. Task 2 consisted of a market analysis to evaluate the potential market of solar hybrid power plants. Twenty-two utilities were selected within nine regions of the country. Both written and verbal correspondence was used to assess solar hybrid power plants with respect to the utilities' future requirements and plans. The parametric analysis of Task 3 evaluated a wide range of subsystem configurations and sizes. These analyses included subsystems from the solar standalone alternate central receiver power system using high-temperature molten salt and from fossil fuel nonsolar subsystems. Task 4, selection of the preferred commerical system configuration, utilized the parametric analyses developed in Task 3 to select system and subsystem configurations for the commercial plant design. Task 5 developed a conceptual design of the selected commercial plant configuration and assessed the related cost and performance. Task 6 assessed the economics and performance of the selected configuration as well as future potential improvements or limitations of the hybrid power plants.

  14. Prognostic Significance of Central Pulse Pressure for Mortality in Patients With Coronary Artery Disease Receiving Repeated Percutaneous Coronary Intervention.

    Science.gov (United States)

    Lin, Mao-Jen; Chen, Chun-Yu; Lin, Hau-De; Lin, Chung-Sheng; Wu, Han-Ping

    2016-03-01

    Coronary artery disease (CAD) is a life-threatening medical emergency which needs urgent medical attention. Percutaneous coronary intervention (PCI) is common and necessary for patients with CAD, but it has not completely evaluated in cases with repeated PCI. Therefore, the aim of this study was to examine the risk factors and prognosis in patients with CAD requiring repeated PCI. This is a prospective observational study. A total of 1126 patients with CAD requiring PCI took part in this study. Clinical parameters including baseline characteristics, hemodynamic data, location of vascular lesions, SYNTAX score, left ventricular ejection fraction, central pulse pressure (CPP), central aortic systolic pressure (CSP), risk factors, and invasive strategies were analyzed to identify the risk factors for patients requiring repeated PCI. We further analyzed the prognosis, including risk for myocardial infarction (MI), cardiovascular (CV) mortality, and all-cause mortality, in patients with repeated PCI. Among patients with PCI, 276 received repeated PCI. Patients in the repeated PCI group had a higher CPP (66.7 vs 62.5 mm Hg; P = 0.006), CSP (139.9 vs 135.9 mm Hg; P = 0.017), and male preponderance (P = 0.012). Drugs including diuretics, beta-blockers (BBs), angiotensin-converting enzyme inhibitors (ACEIs), and aspirin were all used more frequently in the repeated PCI group (all P patients with CAD after performing repeated PCI. PMID:27043689

  15. Preliminary Results From the CAUGHT Experiment: Investigation of the North Central Andes Subsurface Using Receiver Functions and Ambient Noise Tomography

    Science.gov (United States)

    Ryan, J. C.; Ward, K. M.; Porter, R. C.; Beck, S. L.; Zandt, G.; Wagner, L. S.; Minaya, E.; Tavera, H.

    2011-12-01

    Jamie Ryan, Kevin M. Ward, Ryan Porter, Susan Beck, George Zandt, Lara Wagner, Estela Minaya, and Hernando Tavera The University of Arizona The University of North Carolina San Calixto Observatorio, La Paz, Bolivia IGP, Lima, Peru In order to investigate the interplay between crustal shortening, lithospheric removal, and surface uplift we have deployed 50 broadband seismometers in northwestern Bolivia and southern Peru as part of the interdisciplinary Central Andean Uplift and Geodynamics of High Topography (CAUGHT) project. The morphotectonic units of the central Andes from west to east, consist of the Western Cordillera, the active volcanic arc, the Altiplano, an internally drained basin (~4 km elevation), the Eastern Cordillera, the high peaks (~6 km elevation) of an older fold and thrust belt, the Subandean zone, the lower elevation active fold and thrust belt, and the foreland Beni basin. Between northwestern Bolivia and southern Peru, the Altiplano pinches out north of Lake Titicaca as the Andes narrow northward. The CAUGHT seismic instruments were deployed between 13° to 18° S latitudes to investigate the crust and mantle lithosphere of the central Andes in this transitional zone. In northwest Bolivia, perpendicular to the strike of the Andes, there is a total of 275 km of documented upper crustal shortening (15° to 17°S) (McQuarrie et al, 2008). Associated with the shortening is crustal thickening and possibly lithospheric removal as the thickening lithospheric root becomes unstable. An important first order study is to compare upper crustal shortening estimates with present day crustal thickness. To estimate crustal thickness, we have calculated receiver functions using an iterative deconvolution method and used common conversion point stacking along the same profile as the geologically based shortening estimates. In our preliminary results, we observed a strong P to S conversion corresponding to the Moho at approximately 60-65 km depth underneath the

  16. Performance and reliability of a 30-kW triple-junction photovoltaic receiver for 500X concentrator dish or central receiver applications

    Science.gov (United States)

    Verlinden, P. J.; Lewandowski, A.; Lasich, J. B.

    2006-08-01

    Over the last 15 years, Solar Systems has 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 about 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 m2 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/cm2, AM1.5D low AOD, 21°C). 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.

  17. Structure of the upper mantle in the north-western and central United States from USArray S-receiver functions

    Directory of Open Access Journals (Sweden)

    R. Kind

    2015-03-01

    Full Text Available We used more than 40 000 S-receiver functions recorded by the USArray project to study the structure of the upper mantle between the Moho and the 410 km discontinuity from the Phanerozoic western United States to the cratonic central US. We obtained clear observations of downward velocity reductions in the uppermost mantle which are commonly interpreted as the lithosphere-asthenosphere boundary (LAB in the western US and as the mid-lithospheric discontinuity (MLD in the cratonic US. We observe the western LAB reaching partly to the mid-continental rift system underneath the cratonic crust. The MLD is surprisingly plunging steeply towards the west from the Rocky Mountains Front to about 200 km depth near the Sevier Thrust Belt. There is a significant break in the lithosphere at the Sevier Thrust Belt. We also observe a velocity reduction about 30 km above the 410 km discontinuity in the same region where in the western US the LAB is observed, but not in the cratonic US.

  18. The Under-side of the Andes: Using Receiver Functions to Map the North Central Andean Subsurface

    Science.gov (United States)

    Ryan, J. C.; Beck, S. L.; Zandt, G.; Wagner, L. S.; Minaya, E.; Tavera, H.

    2012-12-01

    The Central Andean Uplift and Geodynamics of High Topography (CAUGHT) project is an interdisciplinary project to investigate connections between lithospheric removal, crustal shortening and surface uplift in the northern Bolivia and southern Peru region of the South American Andean orogen. The central Andes are defined by six major tectonomorphic provinces; the forearc, the volcanically active Western Cordillera (WC, ~6 km elevation), the internally drained Altiplano (~4 km elevation), an inactive fold and thrust belt in the Eastern Cordillera (EC, ~6 km elevation), a lower elevation active fold and thrust belt in the Subandean (SA) zone and the Beni, a foreland basin. Forty seismic stations installed for the CAUGHT project were deployed between 13° and 18° S latitude, covering the transition zone where the Altiplano region pinches out in southern Peru, in an effort to better constrain the changing character of the crust and mantle lithosphere. Geologic studies across the northern Bolivian portion of the eastern Andean margin (15-17° S) have documented a total of 275 km of upper crustal shortening (McQuarrie et al, Tectonics, v27, 2008), which may be associated with crustal thickening and/or the removal of lithospheric material as a thickened lithosphere root becomes unstable. For this receiver function (converted wave) study, we have little coverage in the forearc and foreland, ~75 km spacing in most of the array, and a relatively dense ~20 km spaced profile along the Charaña-La Paz-Yucumo transect, the eastern portion of which is nearly coincident with the balanced cross-section of McQuarrie et al. (2008). Using the first year of available data, more than 1200 receiver functions have been calculated using an iterative deconvolution method, and stacked using the common conversion point (CCP) method, along profiles parallel to and nearly coincident to those used for the geologic shortening estimates. We identified arrivals for the Moho and generated a 3D map of

  19. Conceptual design of advanced central receiver power systems sodium-cooled receiver concept. Volume 2, Book 1. Commercial plant conceptual design. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1979-03-01

    The conceptual design of the 100-MW solar tower focus commercial power plant is described in detail. Sodium is pumped up to the top of a tall tower where the receiver is located. The sodium is heated in the receiver and then flows down the tower, through a pressure reducing device, and thence into a large, hot storage tank which is located at ground level and whose size is made to meet a specific thermal energy storage capacity requirement. From this tank, the sodium is pumped by a separate pump, through a system of sodium-to-water steam generators. The steam generator system consists of a separate superheater and reheater operating in parallel and an evaporator unit operating in series with the other two units. The sodium flowing from the evaporator unit is piped to a cold storage tank. From the cold storage tank, sodium is then pumped up to the tip of the tower to complete the cycle. The steam generated in the steam generators is fed to a conventional off-the-shelf, high-efficiency turbine. The steam loop operates in a conventional rankine cycle with the steam generators serving the same purpose as a conventional boiler and water being fed to the evaporator with conventional feedwater pumps. The pressure reducing device (a standard drag valve, for example) serves to mitigate the pressure caused by the static head of sodium and thus allows the large tanks to operate at ambient pressure conditions. (WHK)

  20. Optimization of heliostat field layout in solar central receiver systems on annual basis using differential evolution algorithm

    International Nuclear Information System (INIS)

    Highlights: • Differential evolution optimization model was developed to optimize the heliostat field. • Five optical parameters were considered for the optimization of the optical efficiency. • Optimization using insolation weighted and un-weighted annual efficiency are developed. • The daily averaged annual optical efficiency was calculated to be 0.5023 while the monthly was 0.5025. • The insolation weighted daily averaged annual efficiency was 0.5634. - Abstract: Optimization of a heliostat field is an essential task to make a solar central receiver system effective because major optical losses are associated with the heliostat fields. In this study, a mathematical model was developed to effectively optimize the heliostat field on annual basis using differential evolution, which is an evolutionary algorithm. The heliostat field layout optimization is based on the calculation of five optical performance parameters: the mirror or the heliostat reflectivity, the cosine factor, the atmospheric attenuation factor, the shadowing and blocking factor, and the intercept factor. This model calculates all the aforementioned performance parameters at every stage of the optimization, until the best heliostat field layout based on annual performance is obtained. Two different approaches were undertaken to optimize the heliostat field layout: one with optimizing insolation weighted annual efficiency and the other with optimizing the un-weighted annual efficiency. Moreover, an alternate approach was also proposed to efficiently optimize the heliostat field in which the number of computational time steps was considerably reduced. It was observed that the daily averaged annual optical efficiency was calculated to be 0.5023 as compared to the monthly averaged annual optical efficiency, 0.5025. Moreover, the insolation weighted daily averaged annual efficiency of the heliostat field was 0.5634 for Dhahran, Saudi Arabia. The code developed can be used for any other

  1. Comparison of the performance of two measures of central adiposity among apparently healthy Nigerians using the receiver operating characteristic analysis

    Directory of Open Access Journals (Sweden)

    Christian Ifedili Okafor

    2011-01-01

    Full Text Available Objective: To compare the performance of waist circumference (WC and waist-to-hip ratio (WHR in predicting the presence of cardiovascular risk factors (hypertension and generalized obesity in an apparently healthy population. Materials and Methods: We recruited 898 apparently healthy subjects (318 males and 580 females of the Igbo ethnic group resident in Enugu (urban, Southeast Nigeria. Data collection was done using the World Health Organization Stepwise approach to Surveillance of risk factors (STEPS instrument. Subjects had their weight, height, waist and hip circumferences, systolic and diastolic blood pressures measured according to the guidelines in the step 2 of STEPS instrument. Generalized obesity and hypertension were defined using body mass index (BMI and JNC 7 classifications, respectively. Quantitative and qualitative variables were analyzed using t-test and Chi-square analysis, respectively, while the performance of WC and WHR was compared using the Receiver Operating Characteristic (ROC analysis. P value was set at <0.05. Results: The mean age of the subjects was 48.7 (12.9 years. Central obesity was found in 76.9% and 66.5% of subjects using WHR and WC, respectively. WC had a significantly higher area under the curve (AUC than WHR in all the cardiovascular risk groups, namely, generalized obesity (AUC = 0.88 vs. 0.62, hypertension alone (AUC = 0.60 vs. 0.53, and both generalized obesity and hypertension (AUC = 0.86 vs. 0.57. Conclusion: WC performed better than WHR in predicting the presence of cardiovascular risk factors. Being a simple index, it can easily be measured in routine clinic settings without the need for calculations or use of cumbersome techniques.

  2. Preliminary design of the Carrisa Plains solar central receiver power plant. Volume III, Book 3. Appendices. Part 2

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S. K.

    1983-12-31

    The auxiliary heat transport systems of the Carrisa Plains Solar Power Plant (CPSPP) comprise facilities which are used to support plant operation and provide plant safety and maintenance. The facilities are the sodium purification system, argon cover gas system, sodium receiving and filling system, sodium-water reaction product receiving system, and safety and maintenance equipment. The functions of the facilities of the auxiliary system are described. Design requirements are established based on plant operating parameters. Descriptions are given on the system which will be adequate to perform the function and satisfy the requirements. Valve and equipment lists are included in the appendix.

  3. Performance analysis of a Kalina cycle for a central receiver solar thermal power plant with direct steam generation

    DEFF Research Database (Denmark)

    Modi, Anish; Haglind, Fredrik

    2014-01-01

    % reduction in the storage requirement. The solar receiver showed the highest rate of exergy destruction for both the cycles. The rates of exergy destruction in other components of the cycles were found to be highly dependent on the amount of recuperation, and the ammonia mass fraction and pressure...

  4. Deep dynamical processes in the central-southern Qinghai-Tibet Plateau—Receiver functions and travel-time residuals analysis of north Hi-Climb

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Teleseismic receiver functions and travel-time residuals along the north Hi-Climb broadband seismic array in the central-southern Qinghai-Tibet Plateau show that the lithosphere structures in the central and western Qinghai-Tibet Plateau are different. In the central Qinghai-Tibet Plateau, the Indian Plate is northward subducted beneath the Qiangtang block and arrives at the greatest depth beneath the central-southern Qiangtang block. The delaminated Indian lithospheric slab remains beneath the central Lhasa block to a depth possibly greater than that of the upper interface of the mantle transform zone. In the western Qinghai-Tibet Plateau, the Indian lithospheric plate is gently northward subducted and may have arrived to the south of Tarim plate. Due to the resistance from the gently northward subduction of the Indian mantle lithosphere in the western Qinghai-Tibet Plateau, the upwelling mantle material be-neath the Qiangtang block moves mostly toward the east to bring about the lateral eastward flow of the deep mantle hot material in the central Qinghai-Tibet Plateau.

  5. Deep dynamical processes in the central-southern Qinghai-Tibet Plateau——Receiver functions and travel-time residuals analysis of north Hi-Climb

    Institute of Scientific and Technical Information of China (English)

    LI HaiOu; XU XiWei; JIANG Mei

    2008-01-01

    Teleseismic receiver functions and travel-time residuals along the north Hi-Climb broadband seismic array in the central-southern Qinghai-Tibet Plateau show that the lithosphere structures in the central and western Qinghai-Tibet Plateau are different.In the central Qinghai-Tibet Plateau, the Indian Plate is northward subducted beneath the Qiangtang block and arrives at the greatest depth beneath the central-southern Qiangtang block.The delaminated Indian lithospheric slab remains beneath the central Lhasa block to a depth possibly greater than that of the upper interface of the mantle transform zone.In the western Qinghai-Tibet Plateau, the Indian lithospheric plate is gently northward subducted and may have arrived to the south of Tarim plate.Due to the resistance from the gently northward subduction of the Indian mantle lithosphere in the western Qinghai-Tibet Plateau, the upwelling mantle material beneath the Qiangtang block moves mostly toward the east to bring about the lateral eastward flow of the deep mantle hot material in the central Qinghai-Tibet Plateau.

  6. Preliminary design of the Carrisa Plains solar central receiver power plant. Volume III, Book 3. Appendices, Part 1

    Energy Technology Data Exchange (ETDEWEB)

    Mouradian, E. M.

    1983-12-31

    Thermal analyses for the preliminary design phase of the Receiver of the Carrizo Plains Solar Power Plant are presented. The sodium reference operating conditions (T/sub in/ = 610/sup 0/F, T/sub out/ = 1050/sup 0/F) have been considered. Included are: Nominal flux distribution on receiver panal, Energy input to tubes, Axial temperature distribution; sodium and tubes, Sodium flow distribution, Sodium pressure drop, orifice calculations, Temperature distribution in tube cut (R-0), Backface structure, and Nonuniform sodium outlet temperature. Transient conditions and panel front face heat losses are not considered. These are to be addressed in a subsequent design phase. Also to be considered later are the design conditions as variations from the nominal reference (operating) condition. An addendum, designated Appendix C, has been included describing panel heat losses, panel temperature distribution, and tube-manifold joint thermal model.

  7. In-situ measurement of concentrated solar flux and distribution at the aperture of a central solar receiver

    Science.gov (United States)

    Ferriere, Alain; Volut, Mikael; Perez, Antoine; Volut, Yann

    2016-05-01

    A flux mapping system has been designed, implemented and experimented at the top of the Themis solar tower in France. This system features a moving bar associated to a CCD video camera and a flux gauge mounted onto the bar used as reference measurement for calibration purpose. Images and flux signal are acquired separately. The paper describes the equipment and focus on the data processing to issue the distribution of flux density and concentration at the aperture of the solar receiver. Finally, the solar power entering into the receiver is estimated by integration of flux density. The processing is largely automated in the form of a dedicated software with fast execution. A special attention is paid to the accuracy of the results, to the robustness of the algorithm and to the velocity of the processing.

  8. An artificial vision-based control system for automatic heliostat positioning offset correction in a central receiver solar power plant

    Energy Technology Data Exchange (ETDEWEB)

    Berenguel, M. [Universidad de Almeria, Dept. de Lenguajes y Computacion, La Canada Almeria (Spain); Rubio, F.R.; Lara, P.J.; Arahal, M.R.; Camacho, E.F.; Lopez, M. [Universidad de Sevilla, Dept. de Ingenieria de Sistemas y Automatica, Sevilla (Spain); Valverde, A. [Plataforma Solar de Almeria (PSA-CIEMAT), Tabernas (Almeria) (Spain)

    2004-07-01

    This paper presents the development of a simplified and automatic heliostat positioning offset correction control system using artificial vision techniques and common CCD devices. The heliostats of a solar power plant reflect solar radiation onto a receiver (in this case, a volumetric receiver) placed at the top of a tower in order to provide a desired energy flux distribution correlated with the coolant flow (in this case air mass flow) through the receiver, usually in an open loop control configuration. There exist error sources that increase the complexity of the control system, some of which are systematic ones, mainly due to tolerances, wrong mirror facets alignment (optical errors), errors due to the approximations made when calculating the solar position, etc., that produce errors (offsets) in the heliostat orientation (aiming point). The approximation adopted in this paper is based on the use of a B/W CCD camera to correct these deviations in an automatic way imitating the same procedure followed by the operators. The obtained images are used to estimate the distance between the sunbeam centroid projected by the heliostats and a target placed on the tower, this distance thus is used for low accuracy offset correction purposes. Basic threshold-based image processing techniques are used for automatic correction. (Author)

  9. Proposal of a fluid flow layout to improve the heat transfer in the active absorber surface of solar central cavity receivers

    International Nuclear Information System (INIS)

    The main objective of concentrated solar power is to increase the thermal energy of a fluid, for the fluid to be used, for example, in a power cycle to generate electricity. Such applications present the requirement of appropriately designing the receiver active absorber surface, as the incident radiation flux can be very high. Besides that, the solar image in the receiver is not uniform, so conventional boilers designs are not well suited for these purposes. That point is particularly critical in solar central receivers systems (CRS), where concentrated solar flux is usually above 500 kW/m2, causing thermal and mechanical stress in the absorber panels. This paper analyzes a new thermofluidynamic design of a solar central receiver, which optimizes the heat transfer in the absorber surface. This conceptual receiver presents the following characteristics: the fluid flow pattern is designed according to the radiation flux map symmetry, so more uniform fluid temperatures at the receiver outlet are achieved; the heat transfer irreversibilities are reduced by circulating the fluid from the lower temperature region to the higher temperature region of the absorber surface; the width of each pass is adjusted to the solar flux gradient, to get lower temperature differences between the side tubes of the same pass; and the cooling requirement is ensured by means of adjusting the fluid flow velocity per tube, taking into account the pressure drop. This conceptual scheme has been applied to the particular case of a molten salt single cavity receiver, although the configuration proposed is suitable for other receiver designs and working fluids. - Highlights: ► The solar receiver design proposed optimizes heat transfer in the absorber surface. ► The fluid flow pattern is designed according to the solar flux map symmetry at noon. ► The fluid circulates from the lower to the higher temperature regions. ► The width of each pass is adjusted to the solar flux gradient. ► The

  10. Central receiver solar thermal power system, Phase 1: CDRL Item 2, pilot plant preliminary design report. Volume VII. Pilot plant cost and commercial plant cost and performance

    Energy Technology Data Exchange (ETDEWEB)

    Hallet, Jr., R. W.; Gervais, R. L.

    1980-05-01

    Detailed cost and performance data for the proposed tower focus pilot plant and commercial plant are given. The baseline central receiver concept defined by the MDAC team consists of the following features: (A) an external receiver mounted on a tower, and located in a 360/sup 0/ array of sun-tracking heliostats which comprise the collector subsystem. (B) feedwater from the electrical power generation subsystem is pumped through a riser to the receiver, where the feedwater is converted to superheated steam in a single pass through the tubes of the receiver panels. (C) The steam from the receiver is routed through a downcomer to the ground and introduced to a turbine directly for expansion and generation of electricity, and/or to a thermal storage subsystem, where the steam is condensed in charging heat exchangers to heat a dual-medium oil and rock thermal storage unit (TSU). (D) Extended operation after daylight hours is facilitated by discharging the TSU to generate steam for feeding the admission port of the turbine. (E) Overall control of the system is provided by a master control unit, which handles the interactions between subsystems that take place during startup, shutdown, and transitions between operating modes. (WHK)

  11. Central receiver solar thermal power system, Phase 1. Annual progress report (final) for period ending September 30, 1976

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-02-01

    The program activities since the beginning of the program in July of 1975 through September of 1976 are summarized. The primary efforts during the first portion of this period were the preparation of the Pilot Plant Preliminary Design Baseline, and the Conceptual Design of the three subsystem research experiments. The Preliminary Design Baseline for the Pilot Plant was developed from the commercial plant conceptual design that had been defined prior to the start of this program. It definitized each of the basic Pilot Plant Subsystems and provided the basis for development of the conceptual designs of the research experiments. For each of the solar peculiar subsystems, the Collector Subsystem, the Receiver Subsystem and the Thermal Storage Subsystem, a subsystem research experiment was planned. The Conceptual Design of each of these experiments was prepared and reviewed with ERDA and Sandia in order to obtain authorization for the design, build and test of these experiments. In the Collector Subsystem experiment the design was completed, the four experimental heliostats have been fabricated and erected. Initial calorimeter and radiometer data have been obtained and have demonstrated good correlation with the projected performance. The 5 megawatt thermal experiment receiver has been fabricated by Foster Wheeler Energy Corporation and is now completing erection at the Radiant Heat Test Facility at Sandia in Albuquerque, New Mexico. This testing is scheduled for the period from December 1976 through February 1977. The Thermal Storage Research Experiment fabrication and erection is nearing completion by Georgia Institute of Technology. Checkout of this experiment is scheduled for the first of December 1976 with the test program to be complete by the end of January 1977.

  12. Results of molten salt panel and component experiments for solar central receivers: Cold fill, freeze/thaw, thermal cycling and shock, and instrumentation tests

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, J.E.; Ralph, M.E.; Chavez, J.M.; Dunkin, S.R.; Rush, E.E.; Ghanbari, C.M.; Matthews, M.W.

    1995-01-01

    Experiments have been conducted with a molten salt loop at Sandia National Laboratories in Albuquerque, NM to resolve issues associated with the operation of the 10MW{sub e} Solar Two Central Receiver Power Plant located near Barstow, CA. The salt loop contained two receiver panels, components such as flanges and a check valve, vortex shedding and ultrasonic flow meters, and an impedance pressure transducer. Tests were conducted on procedures for filling and thawing a panel, and assessing components and instrumentation in a molten salt environment. Four categories of experiments were conducted: (1) cold filling procedures, (2) freeze/thaw procedures, (3) component tests, and (4) instrumentation tests. Cold-panel and -piping fill experiments are described, in which the panels and piping were preheated to temperatures below the salt freezing point prior to initiating flow, to determine the feasibility of cold filling the receiver and piping. The transient thermal response was measured, and heat transfer coefficients and transient stresses were calculated from the data. Freeze/thaw experiments were conducted with the panels, in which the salt was intentionally allowed to freeze in the receiver tubes, then thawed with heliostat beams. Slow thermal cycling tests were conducted to measure both how well various designs of flanges (e.g., tapered flanges or clamp type flanges) hold a seal under thermal conditions typical of nightly shut down, and the practicality of using these flanges on high maintenance components. In addition, the flanges were thermally shocked to simulate cold starting the system. Instrumentation such as vortex shedding and ultrasonic flow meters were tested alongside each other, and compared with flow measurements from calibration tanks in the flow loop.

  13. Lithospheric structure across the central Tien Shan constrained by gravity anomalies and joint inversions of receiver function and Rayleigh wave dispersion

    Science.gov (United States)

    Li, Yonghua; Shi, Lei; Gao, Jiayi

    2016-07-01

    Shear wave velocity structure across the central Tien Shan orogeny was generated by jointly inverting Rayleigh wave phase and group velocity with teleseismic P-wave receiver functions at 40 broadband seismic stations. The inferred seismic structure was validated by forward modeling of the complete Bouguer anomaly data. The joint inversion result reveals larger crust thicknesses beneath the Kokshaal (∼68-72 km) and Kyrgyz ranges (∼62-64 km), while other units have crustal thicknesses between 48 and 58 km. A fast velocity layer (Vs = 3.6-3.9 km/s) in the upper crust is found in some seismic stations within the Kazakh Shield. Our models show the presence of high velocity and density layers in the lowermost crust throughout the region, consistent with the presence of mafic/ultramafic lithologies. The large crustal thickness is associated with a thickened mafic layer in the lower crust, indicating that the thickened crust may be partly caused by magmatic underplating. The low velocity and density anomaly in the middle crust, and low upper mantle velocity observed in our model beneath the middle Tien Shan reflect the presence of partial melt in the crust due to the intrusion of hot mantle material. The lack of correlation between Moho depth and topography, together with the gravity results, suggests that the topographic compensation in the central Tien Shan is not confined to the crust. This requires significant support from the mantle to account for the relative high elevation of the middle Tien Shan.

  14. Stereotactic Radiation Therapy can Safely and Durably Control Sites of Extra-Central Nervous System Oligoprogressive Disease in Anaplastic Lymphoma Kinase-Positive Lung Cancer Patients Receiving Crizotinib

    International Nuclear Information System (INIS)

    Purpose: To analyze the durability and toxicity of radiotherapeutic local ablative therapy (LAT) applied to extra-central nervous system (eCNS) disease progression in anaplastic lymphoma kinase-positive non-small cell lung cancer (NSCLC) patients. Methods and Materials: Anaplastic lymphoma kinase-positive NSCLC patients receiving crizotinib and manifesting ≤4 discrete sites of eCNS progression were classified as having oligoprogressive disease (OPD). If subsequent progression met OPD criteria, additional courses of LAT were considered. Crizotinib was continued until eCNS progression was beyond OPD criteria or otherwise not suitable for further LAT. Results: Of 38 patients, 33 progressed while taking crizotinib. Of these, 14 had eCNS progression meeting OPD criteria suitable for radiotherapeutic LAT. Patients with eCNS OPD received 1-3 courses of LAT with radiation therapy. The 6- and 12-month actuarial local lesion control rates with radiation therapy were 100% and 86%, respectively. The 12-month local lesion control rate with single-fraction equivalent dose >25 Gy versus ≤25 Gy was 100% versus 60% (P=.01). No acute or late grade >2 radiation therapy-related toxicities were observed. Median overall time taking crizotinib among those treated with LAT versus those who progressed but were not suitable for LAT was 28 versus 10.1 months, respectively. Patients continuing to take crizotinib for >12 months versus ≤12 months had a 2-year overall survival rate of 72% versus 12%, respectively (P<.0001). Conclusions: Local ablative therapy safely and durably eradicated sites of individual lesion progression in anaplastic lymphoma kinase-positive NSCLC patients receiving crizotinib. A dose–response relationship for local lesion control was observed. The suppression of OPD by LAT in patients taking crizotinib allowed an extended duration of exposure to crizotinib, which was associated with longer overall survival

  15. Central receiver solar thermal power system, Phase 1. CDRL Item 2. Pilot plant preliminary design report. Volume IV. Receiver subsystem. [10-MW Pilot Plant and 100-MW Commercial Plant

    Energy Technology Data Exchange (ETDEWEB)

    Hallet, Jr., R. W.; Gervais, R. L.

    1977-11-01

    The conception, design, and testing of the receiver subsystem proposed by the McDonnell Douglas/Rocketdyne Receiver team for the DOE 10-MW Pilot Plant and the 100-MW Commercial Plant are described. The receiver subsystem consists of the receiver unit, the tower on which the receiver unit is mounted above the collector field, and the supporting control and instrumentation equipment. The plans for implementation of the Pilot Plant are given including the anticipated schedule and production plan (procurement, installation, checkout, and maintenance). Specifications for the performance, design, and test requirements for the Pilot Plant receiver subsystem are included. (WHK)

  16. Computer programming to calculate the variations of characteristic angles of heliostats as a function of time and position in a central receiver solar power plant

    Energy Technology Data Exchange (ETDEWEB)

    Mehrabian, M.A.; Aseman, R.D. [Mechanical Engineering Dept., Shahid Bahonar Univ., Kerman (Iran, Islamic Republic of)

    2008-07-01

    The central receiver solar power plant is composed of a large number of individually stirred mirrors (heliostats), focusing the solar radiation onto a tower-mounted receiver. In this paper, an algorithm is developed based on vector geometry to pick an individual heliostat and calculate its characteristic angles at different times of the day and different days of the year. The algorithm then picks the other heliostats one by one and performs the same calculations as did for the first one. These data are used to control the orientation of heliostats for improving the performance of the field. This procedure is relatively straight-forward, and quite suitable for computer programming. The effect of major parameters such as shading and blocking on the performance of the heliostat field is also studied using this algorithm. The results of computer simulation are presented in three sections: (1) the characteristic angles of individual heliostats, (2) the incidence angle of the sun rays striking individual heliostats, and (3) the blocking and shading effect of each heliostat. The calculations and comparisons of results show that: (a) the average incidence angle in the northern hemisphere at the north side of the tower is less than that at its south side, (b) the cosine losses are reduced as the latitude is increased or the tower height is increased, (c) the blocking effect is more important in winter and its effect is much more noticeable than shading for large fields, (d) the height of the tower does not considerably affect shading; but significantly reduces the blocking effect, and (e) to have no blocking effect throughout the year, the field design should be performed for the winter solstice noon. (orig.)

  17. Communication dated 30 May 2014 received from the Permanent Mission of Uzbekistan to the Agency regarding the implementation of the initiative of the President of Uzbekistan on Establishing a Nuclear-Weapon-Free Zone in Central Asia

    International Nuclear Information System (INIS)

    The Director General has received a note verbale dated 30 May 2014 from the Permanent Mission of Uzbekistan to the Agency regarding the implementation of the initiative of the President of Uzbekistan, HE Mr Islam Karimov, on Establishing a Nuclear-Weapon-Free Zone in Central Asia. The note verbale and its attachment are circulated herewith for information, as requested by the Permanent Mission

  18. Radio receivers

    Science.gov (United States)

    Bankov, V. N.; Barulin, L. G.; Zhodzishskii, M. I.; Malyshev, I. V.; Petrusinskii, V. V.

    The book is concerned with the design of microelectronic radio receivers and their components based on semiconductor and hybrid integrated circuits. Topics discussed include the hierarchical structure of radio receivers, the synthesis of structural schemes, the design of the principal functional units, and the design of radio receiver systems with digital signal processing. The discussion also covers the integrated circuits of multifunctional amplifiers, analog multipliers, charge-transfer devices, frequency filters, piezoelectronic devices, and microwave amplifiers, filters, and mixers.

  19. Comparison of contaminants of emerging concern removal, discharge, and water quality hazards among centralized and on-site wastewater treatment system effluents receiving common wastewater influent.

    Science.gov (United States)

    Du, Bowen; Price, Amy E; Scott, W Casan; Kristofco, Lauren A; Ramirez, Alejandro J; Chambliss, C Kevin; Yelderman, Joe C; Brooks, Bryan W

    2014-01-01

    A comparative understanding of effluent quality of decentralized on-site wastewater treatment systems, particularly for contaminants of emerging concern (CECs), remains less understood than effluent quality from centralized municipal wastewater treatment plants. Using a novel experimental facility with common influent wastewater, effluent water quality from a decentralized advanced aerobic treatment system (ATS) and a typical septic treatment system (STS) coupled to a subsurface flow constructed wetland (WET) were compared to effluent from a centralized municipal treatment plant (MTP). The STS did not include soil treatment, which may represent a system not functioning properly. Occurrence and discharge of a range of CECs were examined using isotope dilution liquid chromatography-tandem mass spectrometry during fall and winter seasons. Conventional parameters, including total suspended solids, carbonaceous biochemical oxygen demand and nutrients were also evaluated from each treatment system. Water quality of these effluents was further examined using a therapeutic hazard modeling approach. Of 19 CECs targeted for study, the benzodiazepine pharmaceutical diazepam was the only CEC not detected in all wastewater influent and effluent samples over two sampling seasons. Diphenhydramine, codeine, diltiazem, atenolol, and diclofenac exhibited significant (ptreatment systems was generally not influenced by season. However, significant differences (pwater quality indicators were observed among the various treatment technologies. For example, removal of most CECs by ATS was generally comparable to MTP. Lowest removal of most CECs was observed for STS; however, removal was improved when coupling the STS to a WET. Across the treatment systems examined, the majority of pharmaceuticals observed in on-site and municipal effluent discharges were predicted to potentially present therapeutic hazards to fish.

  20. 10-MWe solar-thermal central-receiver pilot plant, solar facilities design integration: collector-field optimization report (RADL item 2-25)

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    Appropriate cost and performance models and computer codes have been developed to carry out the collector field optimization, as well as additional computer codes to define the actual heliostat locations in the optimized field and to compute in detail the performance to be expected of the defined field. The range of capabilities of the available optimization and performance codes is described. The role of the optimization code in the definition of the pilot plant is specified, and a complete description of the optimization process itself is given. The detailed cost model used by the optimizer for the commercial system optimization is presented in the form of equations relating the cost element to each of the factors that determine it. The design basis for the commercial system is presented together with the rationale for its selection. The development of the individual heliostat performance code is presented. Use of the individual heliostat code in a completed study of receiver panel power under sunrise startup conditions is described. The procedure whereby performance and heliostat spacing data from the representative commercial-scale system are converted into coefficients of use in the layout processor is described, and the actual procedure used in the layout processor is described. Numerous special studies in support of the pilot plant design are described. (LEW)

  1. Crustal and Upper Mantle Investigations Using Receiver Functions and Tomographic Inversion in the Southern Puna Plateau Region of the Central Andes

    Science.gov (United States)

    Heit, B.; Yuan, X.; Bianchi, M.; Jakovlev, A.; Kumar, P.; Kay, S. M.; Sandvol, E. A.; Alonso, R.; Coira, B.; Comte, D.; Brown, L. D.; Kind, R.

    2011-12-01

    We present here the results obtained using the data form our passive seismic array in the southern Puna plateau between 25°S to 28°S latitude in Argentina and Chile. In first instance we have been able to calculate P and S receiver functions in order to investigate the Moho thickness and other seismic discontinuities in the study area. The RF data shows that the northern Puna plateau has a thicker crust and that the Moho topography is more irregular along strike. The seismic structure and thickness of the continental crust and the lithospheric mantle beneath the southern Puna plateau reveals that the LAB is deeper to the north of the array suggesting lithospheric removal towards the south. Later we performed a joint inversion of teleseismic and regional tomographic data in order to study the distribution of velocity anomalies that could help us to better understand the evolution of the Andean elevated plateau and the role of lithosphere-asthenosphere interactions in this region. Low velocities are observed in correlation with young volcanic centers (e.g. Ojos del Salado, Cerro Blanco, Galan) and agree very well with the position of crustal lineaments in the region. This is suggesting a close relationship between magmatism and lithospheric structures at crustal scale coniciding with the presence of hot asthenospheric material at the base of the crust probably induced by lithospheric foundering.

  2. Vegetation establishment and evolution in four ponds that received sewage and wastewater in a portion of the Olezoa wetland complex, Yaounde, Cameroon, central Africa

    Energy Technology Data Exchange (ETDEWEB)

    Atekwana, E.A. (Western Michigan Univ., Kalamazoo, MI (United States). Dept. of Geology); Agendia, P.L. (Univ. of Yaounde (Cameroon). Dept. of Plant Biology)

    1994-04-01

    A study of the spatial and temporal changes in the pattern and distribution of tropical wetland vegetation in four ponds that received sewage and wastewater discharge, was undertaken for a small wetland ecosystem in the Olezoa drainage basin in Yaounde, Cameroon. More than 25 years of nutrient loading has led to the eutrophication and subsequent establishment of wetland vegetation in these ponds. Estimated free water surface areas of the ponds in 1964, 1976, and 1986 and 1992 determined from digitized aerial photographs and field measurements suggests a decline of 70 to 100% in the pond surface areas due to invasion and colonization by plants. The rate of pond surface decline and vegetation development is correlated with the construction of sewage plants and the discharge of untreated sewage and wastewater into the ponds. The main wetland plants that are established in the ponds consist of aquatic species Nymphae lotus, Enhydra fluctuants, Pistia stratiotes, Commelina sp., Ipomea aquatica and terrestrial species Echinochloa sp., Thalia welwitschii, Polygonum senegalense, Leersia haxandra and Cyperus papyrus. The pattern of wetland plant succession that resulted within each pond is correlated to the timing, duration and magnitude of sewage and wastewater discharge into the wetland complex.

  3. Design, fabrication, and test of a heliostat for a central receiver solar thermal power plant. Project technical report, May 1974--Sep 1975

    Energy Technology Data Exchange (ETDEWEB)

    Blackmon, J.B.

    1975-09-01

    A full-scale central pedestal mounted elevation/azimuth heliostat was designed, fabricated, and tested. The heliostat consisted of a flat reflective surface composed of two co-planar lights of back silvered (second surface) glass, each 3.7 m (12 ft) x 1.85 m (6 ft) x 6 mm (1/4 inch) bonded to a steel frame structural support. The structural support was mounted on a drive housing equipped with a linear actuator for control of the elevation (tilt) axis, and a harmonic drive for azimuth control. DC gear motors (1/30 hp) were used in both drive axes. A quadrant photosensor mounted on a separate pedestal and aligned along the target-mirror of sight provided error signals to an analogue circuit which performed the error signal transformations and provided properly apportioned steering commands to the DC motors on the elevation/azimuth movement. Tracking and beam dispersion characteristics were investigated at six typical positions in the field ranging from 300 to 3000 ft horizontally from a screen target suspended between two 360 ft high towers. (GRA)

  4. Solar advanced internal film receiver

    International Nuclear Information System (INIS)

    In a Solar Central Internal Film Receiver, the heat absorbing fluid (a molten nitrate salt) flows in a thin film down over the non illuminated side of an absorber panel. Since the molten salt working fluid is not contained in complicated tube manifolds, the receiver design is simples than a conventional tube type-receiver resulting in a lower cost and a more reliable receiver. The Internal Film Receiver can be considered as an alternative to the Direct Absorption Receiver, in the event that the current problems of the last one can not be solved. It also describes here the test facility which will be used for its solar test, and the test plans foreseen. (Author) 17 refs

  5. Electronic warfare receivers and receiving systems

    CERN Document Server

    Poisel, Richard A

    2014-01-01

    Receivers systems are considered the core of electronic warfare (EW) intercept systems. Without them, the fundamental purpose of such systems is null and void. This book considers the major elements that make up receiver systems and the receivers that go in them.This resource provides system design engineers with techniques for design and development of EW receivers for modern modulations (spread spectrum) in addition to receivers for older, common modulation formats. Each major module in these receivers is considered in detail. Design information is included as well as performance tradeoffs o

  6. 塔式太阳能电站聚光镜场的土地利用率研究%Study on ground coverage of heliostats field in central receiver solar power plant

    Institute of Scientific and Technical Information of China (English)

    丁婷婷; 祝雪妹

    2012-01-01

    Most conventional heliostats field consist of rectangular heliostats, which have regular arrangement in central receiver solar power plant. The maximum ground coverage possible of such heliostats field without colliding neighboring reflectors is 58%. In this paper, a regular and radial arrangement of heliostats field is presented, a ground coverage model of different shape reflectors is carried out, and calculates different ground coverage in different situations. The simulation results show that a maximum ground coverage will obtain when width -height ratio of rectangular reflectors and hexagonal reflectors meet necessary condition. With die shape of hexagonal reflectors ground coverage is up to 100%.%塔式太阳能热发电站的聚光镜场大多是由按一定规律排列的矩形定日镜组成,在相邻定日镜间无机械碰撞的情况下,聚光镜场的最大土地利用率仅为58%.文章提出了选用规则交错排列的聚光镜场布置方案,建立不同形状定日镜的土地利用模型,并计算出不同情况下的最大土地利用率.通过仿真得出,矩形定日镜和六边形定日镜在一定长宽比时可获得最大土地利用率,其中六边形定日镜的土地利用率最高,约为100%.

  7. PERFORMANCE COMPARRIONS OF SOLAR CENTRAL RECEIVERS AND WORKING FLUIDS FOR SOLAR POWER TOWER SYSTEMS%塔式太阳能热发电吸热器性能及工作介质的比较研究

    Institute of Scientific and Technical Information of China (English)

    杨敏林; 杨晓西; 张珊珊

    2008-01-01

    In this paper,comparisons of different receivers were made on the performance of solar power tower systems. Cavity receiver features higher heat efficiency than external receiver but has drawback in economic performance. Direct absorption receiver is obviously superior to indirect absorption receiver by reducing start-up losses,lowering thermal losses and improving absorptance. As the heat transfer fluid,molten salt has higher thermal capacity and better performance in economic and safety aspects,but the receiver needs accurate heliostat tracking and its working temperature is restrictedly restrained. On the contrary,air has no limitations on the working temperature and is quite friendly to the environment. But it has small thermal capacity,which leads to a reduction in the economic capability.Water/steam receiver has good features in efficiency and thermal capacity but the piping and vessels need to tolerate high pressure.%比较了各种吸热器在塔式太阳能系统中的表现,结果发现腔式吸热器比外热式吸热器具有更高的吸热效率,但经济性略差;在工作介质方面,熔盐介质具有热容量大及经济性、安全性较好的优点,但工作温度受限,对反射镜的控制精度要求高;而空气没有温度限制,并且对环境友好,但其热容量较小,导致经济性不好;水/蒸汽式吸热器有较高的效率及热容量,但管路及容器等需承受高压.

  8. Ceramic high temperature receiver design and tests

    Science.gov (United States)

    Davis, S. B.

    1982-01-01

    The High Temperature Solar Thermal Receiver, which was tested a Edwards AFB, CA during the winter of 1980-1981, evolved from technologies developed over a five year period of work. This receiver was tested at the Army Solar Furnace at White Sands, NM in 1976. The receiver, was tested successfully at 1768 deg F and showed thermal efficiencies of 85%. The results were sufficiently promising to lead ERDA to fund our development and test of a 250 kW receiver to measure the efficiency of an open cavity receiver atop a central tower of a heliostat field. This receiver was required to be design scalable to 10, 50, and 100 MW-electric sizes to show applicability to central power tower receivers. That receiver employed rectagular silicon carbide panels and vertical stanchions to achieve scalability. The construction was shown to be fully scalable; and the receiver was operated at temperatures up to 2000 deg F to achieve the performance goals of the experiment during tests at the GIT advanced components test facility during the fall of 1978.

  9. Low complexity MIMO receivers

    CERN Document Server

    Bai, Lin; Yu, Quan

    2014-01-01

    Multiple-input multiple-output (MIMO) systems can increase the spectral efficiency in wireless communications. However, the interference becomes the major drawback that leads to high computational complexity at both transmitter and receiver. In particular, the complexity of MIMO receivers can be prohibitively high. As an efficient mathematical tool to devise low complexity approaches that mitigate the interference in MIMO systems, lattice reduction (LR) has been widely studied and employed over the last decade. The co-authors of this book are world's leading experts on MIMO receivers, and here they share the key findings of their research over years. They detail a range of key techniques for receiver design as multiple transmitted and received signals are available. The authors first introduce the principle of signal detection and the LR in mathematical aspects. They then move on to discuss the use of LR in low complexity MIMO receiver design with respect to different aspects, including uncoded MIMO detection...

  10. Delphi Accounts Receivable Module

    Data.gov (United States)

    Department of Transportation — Delphi accounts receivable module contains the following data elements, but are not limited to customer information, cash receipts, line of accounting details, bill...

  11. Mometasone Furoate Effect on Acute Skin Toxicity in Breast Cancer Patients Receiving Radiotherapy: A Phase III Double-Blind, Randomized Trial From the North Central Cancer Treatment Group N06C4

    International Nuclear Information System (INIS)

    Purpose: A two-arm, double-blind, randomized trial was performed to evaluate the effect of 0.1% mometasone furoate (MMF) on acute skin-related toxicity in patients undergoing breast or chest wall radiotherapy. Methods and Materials: Patients with ductal carcinoma in situ or invasive breast carcinoma who were undergoing external beam radiotherapy to the breast or chest wall were randomly assigned to apply 0.1% MMF or placebo cream daily. The primary study endpoint was the provider-assessed maximal grade of Common Terminology Criteria for Adverse Events, version 3.0, radiation dermatitis. The secondary endpoints included provider-assessed Common Terminology Criteria for Adverse Events Grade 3 or greater radiation dermatitis and adverse event monitoring. The patient-reported outcome measures included the Skindex-16, the Skin Toxicity Assessment Tool, a Symptom Experience Diary, and a quality-of-life self-assessment. An assessment was performed at baseline, weekly during radiotherapy, and for 2 weeks after radiotherapy. Results: A total of 176 patients were enrolled between September 21, 2007, and December 7, 2007. The provider-assessed primary endpoint showed no difference in the mean maximum grade of radiation dermatitis by treatment arm (1.2 for MMF vs. 1.3 for placebo; p = .18). Common Terminology Criteria for Adverse Events toxicity was greater in the placebo group (p = .04), primarily from pruritus. For the patient-reported outcome measures, the maximum Skindex-16 score for the MMF group showed less itching (p = .008), less irritation (p = .01), less symptom persistence or recurrence (p = .02), and less annoyance with skin problems (p = .04). The group's maximal Skin Toxicity Assessment Tool score showed less burning sensation (p = .02) and less itching (p = .002). Conclusion: Patients receiving daily MMF during radiotherapy might experience reduced acute skin toxicity compared with patients receiving placebo.

  12. Mometasone Furoate Effect on Acute Skin Toxicity in Breast Cancer Patients Receiving Radiotherapy: A Phase 3 Double-Blind, Randomized Trial from the North Central Cancer Treatment Group N06C4

    Science.gov (United States)

    Miller, Robert C.; Schwartz, David J.; Sloan, Jeff A.; Griffin, Patricia C.; Deming, Richard L.; Anders, Jon C.; Stoffel, Thomas J.; Haselow, Robert E.; Schaefer, Paul L.; Bearden, James D.; Atherton, Pamela J.; Loprinzi, Charles L.; Martenson, James A.

    2010-01-01

    Purpose A 2-arm, double-blinded, randomized trial to evaluate the effect of 0.1% mometasone furoate (MMF) on acute skin-related toxicity in patients undergoing breast or chest wall radiotherapy. Methods and Materials Patients with ductal carcinoma in situ or invasive breast carcinoma receiving external beam radiotherapy to breast or chest wall were randomly assigned to daily apply 0.1% MMF or placebo cream. Primary study end point was provider-assessed maximum grade of Common Terminology Criteria for Adverse Events (CTCAE) version 3.0 radiation dermatitis. Secondary end points included provider-assessed CTCAE grade 3 or greater radiation dermatitis and adverse-event monitoring. Patient-reported outcome (PRO) measures included the Skindex-16, the Skin Toxicity Assessment Tool, a Symptom Experience Diary, and quality of life self-assessment. Assessment was performed at baseline, weekly during radiotherapy, and for 2 weeks after radiotherapy. Results In total, 176 patients were enrolled from September 21, 2007 through December 7, 2007. The provider-assessed primary end point showed no difference in mean maximum grade of radiation dermatitis by treatment arm (1.2 for MMF vs 1.3 for placebo; P=.18). CTCAE toxicity was greater in placebo group (P=.04), primarily from pruritus. For PRO measures, the maximum Skindex-16 score for MMF group showed less itching (P=.008), less irritation (P=.01), less symptom persistence or recurrence (P=.02), and less annoyance with skin problems (P=.04); the group's maximum Skin Toxicity Assessment Tool score showed less burning sensation (P=.02) and less itching (P=.002). Conclusion Patients receiving daily MMF during radiotherapy may experience reduced acute skin toxicity in comparison to placebo. PMID:20800381

  13. Ceramic Solar Receiver

    Science.gov (United States)

    Robertson, C., Jr.

    1984-01-01

    Solar receiver uses ceramic honeycomb matrix to absorb heat from Sun and transfer it to working fluid at temperatures of 1,095 degrees and 1,650 degrees C. Drives gas turbine engine or provides heat for industrial processes.

  14. Receiver Gain Modulation Circuit

    Science.gov (United States)

    Jones, Hollis; Racette, Paul; Walker, David; Gu, Dazhen

    2011-01-01

    A receiver gain modulation circuit (RGMC) was developed that modulates the power gain of the output of a radiometer receiver with a test signal. As the radiometer receiver switches between calibration noise references, the test signal is mixed with the calibrated noise and thus produces an ensemble set of measurements from which ensemble statistical analysis can be used to extract statistical information about the test signal. The RGMC is an enabling technology of the ensemble detector. As a key component for achieving ensemble detection and analysis, the RGMC has broad aeronautical and space applications. The RGMC can be used to test and develop new calibration algorithms, for example, to detect gain anomalies, and/or correct for slow drifts that affect climate-quality measurements over an accelerated time scale. A generalized approach to analyzing radiometer system designs yields a mathematical treatment of noise reference measurements in calibration algorithms. By treating the measurements from the different noise references as ensemble samples of the receiver state, i.e. receiver gain, a quantitative description of the non-stationary properties of the underlying receiver fluctuations can be derived. Excellent agreement has been obtained between model calculations and radiometric measurements. The mathematical formulation is equivalent to modulating the gain of a stable receiver with an externally generated signal and is the basis for ensemble detection and analysis (EDA). The concept of generating ensemble data sets using an ensemble detector is similar to the ensemble data sets generated as part of ensemble empirical mode decomposition (EEMD) with exception of a key distinguishing factor. EEMD adds noise to the signal under study whereas EDA mixes the signal with calibrated noise. It is mixing with calibrated noise that permits the measurement of temporal-functional variability of uncertainty in the underlying process. The RGMC permits the evaluation of EDA by

  15. Wideband CMOS receivers

    CERN Document Server

    Oliveira, Luis

    2015-01-01

    This book demonstrates how to design a wideband receiver operating in current mode, in which the noise and non-linearity are reduced, implemented in a low cost single chip, using standard CMOS technology.  The authors present a solution to remove the transimpedance amplifier (TIA) block and connect directly the mixer’s output to a passive second-order continuous-time Σ∆ analog to digital converter (ADC), which operates in current-mode. These techniques enable the reduction of area, power consumption, and cost in modern CMOS receivers.

  16. Zero-power receiver

    Energy Technology Data Exchange (ETDEWEB)

    Brocato, Robert W.

    2016-10-04

    An unpowered signal receiver and a method for signal reception detects and responds to very weak signals using pyroelectric devices as impedance transformers and/or demodulators. In some embodiments, surface acoustic wave devices (SAW) are also used. Illustrative embodiments include satellite and long distance terrestrial communications applications.

  17. Olympus beacon receiver

    Science.gov (United States)

    Ostergaard, Jens

    1988-01-01

    A medium-size Beacon Receiving System for reception and processing of the B1 (20 GHz) and B2 (30 GHz) beacons from Olympus has been developed. Integration of B1 and B2 receiving equipment into one system using one antenna and a common computer for control and data processing provides the advantages of a compact configuration and synchronization of the two receiver chains. Range for co-polar signal attenuation meaurement is about 30 dB for both beacons, increasing to 40 dB for B2 if the receivers are synchronized to B1. The accuracy is better than 0.5 dB. Cross-polarization discriminations of the order of 10 to 30 dB may be determined with an accuracy of 1 to 2 dB. A number of radiometers for complementary measurements of atmospheric attenuation of 13 to 30 GHz has also been constructed. A small multi-frequency system for operation around 22 GHz and 31 GHz is presently under development.

  18. Digital Receiver Phase Meter

    Science.gov (United States)

    Marcin, Martin; Abramovici, Alexander

    2008-01-01

    The software of a commercially available digital radio receiver has been modified to make the receiver function as a two-channel low-noise phase meter. This phase meter is a prototype in the continuing development of a phase meter for a system in which radiofrequency (RF) signals in the two channels would be outputs of a spaceborne heterodyne laser interferometer for detecting gravitational waves. The frequencies of the signals could include a common Doppler-shift component of as much as 15 MHz. The phase meter is required to measure the relative phases of the signals in the two channels at a sampling rate of 10 Hz at a root power spectral density digital receiver. The input RF signal is first fed to the input terminal of an analog-to-digital converter (ADC). To prevent aliasing errors in the ADC, the sampling rate must be at least twice the input signal frequency. The sampling rate of the ADC is governed by a sampling clock, which also drives a digital local oscillator (DLO), which is a direct digital frequency synthesizer. The DLO produces samples of sine and cosine signals at a programmed tuning frequency. The sine and cosine samples are mixed with (that is, multiplied by) the samples from the ADC, then low-pass filtered to obtain in-phase (I) and quadrature (Q) signal components. A digital signal processor (DSP) computes the ratio between the Q and I components, computes the phase of the RF signal (relative to that of the DLO signal) as the arctangent of this ratio, and then averages successive such phase values over a time interval specified by the user.

  19. Pressure difference receiving ears

    DEFF Research Database (Denmark)

    Michelsen, Axel; Larsen, Ole Næsbye

    2007-01-01

    of such pressure difference receiving ears have been hampered by lack of suitable experimental methods. In this review, we review the methods for collecting reliable data on the binaural directional cues at the eardrums, on how the eardrum vibrations depend on the direction of sound incidence, and on how sound...... waves behave in the air spaces leading to the interior surfaces of eardrums. A linear mathematical model with well-defined inputs is used for exploring how the directionality varies with the binaural directional cues and the amplitude and phase gain of the sound pathway to the inner surface...

  20. Adaptive antennas and receivers

    CERN Document Server

    Weiner, Melvin M

    2005-01-01

    In our modern age of remote sensing, wireless communication, and the nearly endless list of other antenna-based applications, complex problems require increasingly sophisticated solutions. Conventional antenna systems are no longer suited to high-noise or low-signal applications such as intrusion detection. Detailing highly effective approaches to non-Gaussian weak signal detection, Adaptive Antennas and Receivers provides an authoritative introduction to state-of-the-art research on the modeling, testing, and application of these technologies.Edited by innovative researcher and eminent expert

  1. Solar augmentation for process heat with central receiver technology

    Science.gov (United States)

    Kotzé, Johannes P.; du Toit, Philip; Bode, Sebastian J.; Larmuth, James N.; Landman, Willem A.; Gauché, Paul

    2016-05-01

    Coal fired boilers are currently one of the most widespread ways to deliver process heat to industry. John Thompson Boilers (JTB) offer industrial steam supply solutions for industry and utility scale applications in Southern Africa. Transport cost add significant cost to the coal price in locations far from the coal fields in Mpumalanga, Gauteng and Limpopo. The Helio100 project developed a low cost, self-learning, wireless heliostat technology that requires no ground preparation. This is attractive as an augmentation alternative, as it can easily be installed on any open land that a client may have available. This paper explores the techno economic feasibility of solar augmentation for JTB coal fired steam boilers by comparing the fuel savings of a generic 2MW heliostat field at various locations throughout South Africa.

  2. La Gestion des Ressources Naturelles dans les Zones Périurbaines d’Afrique Centrale : une approche privilégiant les parties prenantes Natural resources management in the peri-urban zones of Central Africa: an approach privileging the receiving parties

    Directory of Open Access Journals (Sweden)

    Theodore Trefon

    2012-02-01

    Full Text Available O presente artigo apresenta o quadro conceptual e os primeiros resultados de um es­tudo em curso sobre processos de gestão de recursos naturais, em espaços peri-urbanos da África Central. Com base em dados etnográficos das realidades empíricas de Kinshasa e Lubumbashi (República Democrática do Congo e de Brazzaville (República do Congo, o texto analisa sobretudo os conceitos de «governação ambiental» e de «espaço peri-urbano», partindo das lógicas dos próprios protagonistas envolvidos na gestão dos re­cursos naturais. Deste modo, são exploradas as ambiguidades, ambivalências, relações de poder e tensões sociais geradas ou sustentadas por certas peculiaridades dos jogos de poder que envolvem os diferentes actores sociais considerados.The article presents a conceptual framework and the first results of an ongoing research on processes of natural resources management in peri-urban areas of Central Africa. Based on ethnographic data from the empirical realities of Kinshasa and Lubumbashi (Democratic Republic of Congo and of Brazzaville (Republic of Congo, the text analyses especially the concepts of «environmental governance» and «peri-urban spaces», based on the logics of the very protagonists involved in the natural resources management. This way, the text explores the ambiguities, ambivalences, power relations and social tensions generated or sustained by certain peculiarities of the power strategies in which these social actors are involved.

  3. The Central Trigger Processor (CTP)

    CERN Multimedia

    Franchini, Matteo

    2016-01-01

    The Central Trigger Processor (CTP) receives trigger information from the calorimeter and muon trigger processors, as well as from other sources of trigger. It makes the Level-1 decision (L1A) based on a trigger menu.

  4. GNSS Software Receiver for UAVs

    DEFF Research Database (Denmark)

    Olesen, Daniel Madelung; Jakobsen, Jakob; von Benzon, Hans-Henrik;

    2016-01-01

    This paper describes the current activities of GPS/GNSS Software receiver development at DTU Space. GNSS Software receivers have received a great deal of attention in the last two decades and numerous implementations have already been presented. DTU Space has just recently started development of ...... of our own GNSS software-receiver targeted for mini UAV applications, and we will in in this paper present our current progress and briefly discuss the benefits of Software Receivers in relation to our research interests....

  5. CERN apprentice receives award

    CERN Multimedia

    2008-01-01

    Another CERN apprentice has received an award for the quality of his work. Stéphane Küng (centre), at the UIG ceremony last November, presided over by Geneva State Councillor Pierre-François Unger, Head of the Department of Economics and Health. Electronics technician Stéphane Küng was honoured in November by the Social Foundation of the Union Industrielle Genevoise (UIG) as one of Geneva’s eight best apprentices in the field of mechatronics. The 20-year-old Genevan obtained his Federal apprentice’s certificate (Certificat fédéral de capacité - CFC) in June 2007, achieving excellent marks in his written tests at the Centre d’Enseignement Professionnel Technique et Artisanal (CEPTA). Like more than 200 youngsters before him, Stéphane Küng spent part of his four-year sandwich course working at CERN, where he followed many practical training courses and gained valuable hands-on experience in various technical groups and labs. "It’ always very gr...

  6. Performance outlook of the SCRAP receiver

    Science.gov (United States)

    Lubkoll, Matti; von Backström, Theodor W.; Harms, Thomas M.

    2016-05-01

    A combined cycle (CC) concentrating solar power (CSP) plant provides significant potential to achieve an efficiency increase and an electricity cost reduction compared to current single-cycle plants. A CC CSP system requires a receiver technology capable of effectively transferring heat from concentrated solar irradiation to a pressurized air stream of a gas turbine. The small number of pressurized air receivers demonstrated to date have practical limitations, when operating at high temperatures and pressures. As yet, a robust, scalable and efficient system has to be developed and commercialized. A novel receiver system, the Spiky Central Receiver Air Pre-heater (SCRAP) concept has been proposed to comply with these requirements. The SCRAP system is conceived as a solution for an efficient and robust pressurized air receiver that could be implemented in CC CSP concepts or standalone solar Brayton cycles without a bottoming Rankine cycle. The presented work expands on previous publications on the thermal modeling of the receiver system. Based on the analysis of a single heat transfer element (spike), predictions for its thermal performance can be made. To this end the existing thermal model was improved by heat transfer characteristics for the jet impingement region of the spike tip as well as heat transfer models simulating the interaction with ambient. While the jet impingement cooling effect was simulated employing a commercial CFD code, the ambient heat transfer model was based on simplifying assumptions in order to employ empirical and analytical equations. The thermal efficiency of a spike under design conditions (flux 1.0 MW/m2, air outlet temperature just below 800 °C) was calculated at approximately 80 %, where convective heat losses account for 16.2 % of the absorbed radiation and radiative heat losses for a lower 2.9 %. This effect is due to peak surface temperatures occurring at the root of the spikes. It can thus be concluded that the geometric

  7. Advanced solar thermal receiver technology

    Science.gov (United States)

    Kudirka, A. A.; Leibowitz, L. P.

    1980-01-01

    Development of advanced receiver technology for solar thermal receivers designed for electric power generation or for industrial applications, such as fuels and chemical production or industrial process heat, is described. The development of this technology is focused on receivers that operate from 1000 F to 3000 F and above. Development strategy is mapped in terms of application requirements, and the related system and technical requirements. Receiver performance requirements and current development efforts are covered for five classes of receiver applications: high temperature, advanced Brayton, Stirling, and Rankine cycle engines, and fuels and chemicals.

  8. Reflux solar receiver design considerations

    Science.gov (United States)

    Diver, R. B.

    Reflux heat-pipe and pool-boiler receivers are being developed to improve upon the performance and life of directly-illuminated tube receiver technology used in previous successful demonstrations of dish-Stirling systems. The design of a reflux receiver involves engineering tradeoffs. In this paper, on-sun performance measurements of the Sandia pool-boiler receiver are compared with results from the reflux receiver thermal analysis model, AEETES. Flux and performance implications of various design options are analyzed and discussed.

  9. RFI receiver. [deep space network

    Science.gov (United States)

    Lay, R.

    1980-01-01

    An S-band radio frequency interference (RFI) receiver to analyze and identify sources of RFI problems in the Deep Space Network DSN tracking stations is described. The RFI receiver is a constant gain, double conversion, open loop receiver with dual sine/cosine channel outputs, providing a total of 20 MHZ monitoring capability. This receiver is computer controlled using a MODCOMP II miniprocessor. The RFI receiver has been designed to operate at a 150 Kelvin system noise temperature accomplished by cascading two low noise field effect transistor (FET) amplifiers for the receiver front-end. The first stage low noise FET amplifier is mounted at the feed horn to minimize any cable losses to achieve a lower system noise temperature. The receiver is tunable over the frequency range of 2150 to 2450 MHz in both sine/cosine output channels with a resolution of 100 kHz.

  10. Solar advanced internal film receiver; Receptor avanzado de pelicular interna

    Energy Technology Data Exchange (ETDEWEB)

    Torre Cabezas, M. de la

    1990-07-01

    In a Solar Central Internal Film Receiver, the heat absorbing fluid (a molten nitrate salt) flows in a thin film down over the non illuminated side of an absorber panel. Since the molten salt working fluid is not contained in complicated tube manifolds, the receiver design is simples than a conventional tube type-receiver resulting in a lower cost and a more reliable receiver. The Internal Film Receiver can be considered as an alternative to the Direct Absorption Receiver, in the event that the current problems of the last one can not be solved. It also describes here the test facility which will be used for its solar test, and the test plans foreseen. (Author) 17 refs.

  11. A final report on the Phase 1 testing of a molten-salt cavity receiver

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, J M [ed.; Smith, D C [Babcock and Wilcox Co., Barberton, OH (United States). Nuclear Equipment Div.

    1992-05-01

    This report describes the design, construction, and testing of a solar central receiver using molten nitrate salt as a heat exchange fluid. Design studies for large commercial plants (30--100 MWe) have shown molten salt to be an excellent fluid for solar thermal plants as it allows for efficient thermal storage. Plant design studies concluded that an advanced receiver test was required to address uncertainties not covered in prior receiver tests. This recommendation led to the current test program managed by Sandia National Laboratories for the US Department of Energy. The 4.5 MWt receiver is installed at Sandia National Laboratories' Central Receiver Test Facility in Albuquerque, New Mexico. The receiver incorporates features of large commercial receiver designs. This report describes the receiver's configuration, heat absorption surface (design and sizing), the structure and supporting systems, and the methods for control. The receiver was solar tested during a six-month period at the Central Receiver Test Facility in Albuquerque, NM. The purpose of the testing was to characterize the operational capabilities of the receiver under a number of solar operating and stand-by conditions. This testing consisted of initial check-out of the systems, followed by steady-state performance, transient receiver operation, receiver operation in clouds, receiver thermal loss testing, receiver start-up operation, and overnight thermal conditioning tests. This report describes the design, fabrication, and results of testing of the receiver.

  12. Stability of heterodyne terahertz receivers

    NARCIS (Netherlands)

    Kooi, J.W.; Baselmans, J.J.A.; Baryshev, A.; Schieder, R.; Hajenius, M.; Gao, J.R.; Klapwijk, T.M.; Voronov, B.; Gol'tsman, G.

    2006-01-01

    In this paper we discuss the stability of heterodyne terahertz receivers based on small volume NbN phonon cooled hot electron bolometers (HEBs). The stability of these receivers can be broken down in two parts: the intrinsic stability of the HEB mixer and the stability of the local oscillator (LO) s

  13. Noise Stability of SIS Receivers

    Science.gov (United States)

    Kooi, J. W.; Chattopadhyay, G.; Thielman, M.; Phillips, T. G.; Schieder, R.

    2000-05-01

    There is a strong interest in the submillimeter astronomy community to increase the IF bandwidth of SIS receivers in order to better facilitate broad spectral linewidth and continuum observations of extragalactic sources. However, with an increase in receiver IF bandwidth there is a decrease in the mixer stability. This in turn effects the integration efficiency and quality of the measurement. In order to better understand the noise mechanisms responsible for reducing the receiver stability, we employed a technique first described by D.W. Allan and later elaborated upon by Schieder et al. In this paper we address a variety of factors that degrade the noise stability of SIS receivers. The goal of this exercise is to make recommendations aimed at maximizing SIS receiver stability.

  14. Customizable Digital Receivers for Radar

    Science.gov (United States)

    Moller, Delwyn; Heavey, Brandon; Sadowy, Gregory

    2008-01-01

    Compact, highly customizable digital receivers are being developed for the system described in 'Radar Interferometer for Topographic Mapping of Glaciers and Ice Sheets' (NPO-43962), NASA Tech Briefs, Vol. 31, No. 7 (August 2007), page 72. The receivers are required to operate in unison, sampling radar returns received by the antenna elements in a digital beam-forming (DBF) mode. The design of these receivers could also be adapted to commercial radar systems. At the time of reporting the information for this article, there were no commercially available digital receivers capable of satisfying all of the operational requirements and compact enough to be mounted directly on the antenna elements. A provided figure depicts the overall system of which the digital receivers are parts. Each digital receiver includes an analog-to-digital converter (ADC), a demultiplexer (DMUX), and a field-programmable gate array (FPGA). The ADC effects 10-bit band-pass sampling of input signals having frequencies up to 3.5 GHz. The input samples are demultiplexed at a user-selectable rate of 1:2 or 1:4, then buffered in part of the FPGA that functions as a first-in/first-out (FIFO) memory. Another part of the FPGA serves as a controller for the ADC, DMUX, and FIFO memory and as an interface between (1) the rest of the receiver and (2) a front-panel data port (FPDP) bus, which is an industry-standard parallel data bus that has a high data-rate capability and multichannel configuration suitable for DBF. Still other parts of the FPGA in each receiver perform signal-processing functions. The digital receivers can be configured to operate in a stand-alone mode, or in a multichannel mode as needed for DBF. The customizability of the receiver makes it applicable to a broad range of system architectures. The capability for operation of receivers in either a stand-alone or a DBF mode enables the use of the receivers in an unprecedentedly wide variety of radar systems.

  15. Techniques to Measure Solar Flux Density Distribution on Large-Scale Receivers

    OpenAIRE

    Röger, Marc; Herrmann, Patrik; Ulmer, Steffen; Ebert, Miriam; Prahl, Christoph; Göhring, Felix

    2014-01-01

    Flux density measurement applied to central receiver ystems delivers the spatial distribution of the concentrated solar radiation on the receiver aperture, measures receiver input power, and monitors and might control heliostat aimpoints. Commercial solar tower plants have much larger aperture surfaces than the receiver prototypes tested in earlier research and development (R&D) projects. Existing methods to measure the solar flux density in the receiver aperture face new challenges reg...

  16. Rogoff's 'Conservative' Central Banker Restored

    OpenAIRE

    Herrendorf, Berthold; Lockwood, Ben

    1996-01-01

    This paper shows that delegation of monetary policy to a weight-conservative central banker is optimal, although the government can also use an inflation contract, an employment target, an inflation target, or any combination of these, to control the central banker. The key feature of our model is a stochastic inflation bias, arising when wage-setters receive some information about a supply shock prior to signing nominal wage contracts. Weight-conservatism is shown to be desirable if the stoc...

  17. Solar dynamic heat receiver technology

    Science.gov (United States)

    Sedgwick, Leigh M.

    1991-01-01

    A full-size, solar dynamic heat receiver was designed to meet the requirements specified for electrical power modules on the U.S. Space Station, Freedom. The heat receiver supplies thermal energy to power a heat engine in a closed Brayton cycle using a mixture of helium-xenon gas as the working fluid. The electrical power output of the engine, 25 kW, requires a 100 kW thermal input throughout a 90 minute orbit, including when the spacecraft is eclipsed for up to 36 minutes from the sun. The heat receiver employs an integral thermal energy storage system utilizing the latent heat available through the phase change of a high-temperature salt mixture. A near eutectic mixture of lithium fluoride and calcium difluoride is used as the phase change material. The salt is contained within a felt metal matrix which enhances heat transfer and controls the salt void distribution during solidification. Fabrication of the receiver is complete and it was delivered to NASA for verification testing in a simulated low-Earth-orbit environment. This document reviews the receiver design and describes its fabrication history. The major elements required to operate the receiver during testing are also described.

  18. Rated MW from a heliostat field on cylindrical external receiver

    Energy Technology Data Exchange (ETDEWEB)

    Al-Rabghi, O.M.; Fathalah, K.A. [King Abdulaziz Univ., Mechanical Engineering Dep., Jeddah (Saudi Arabia); Elsayed, M.M. [Kuwait Univ., Mechanical Engineering Dep., Safat (Kuwait)

    1995-12-31

    Some of the reflected beam radiation from a heliostat field bypasses the receiver surface. The spillage factor which is a measure of how much of reflected beam radiation actually intercepted by the receiver surface, is calculated and plotted for easy access. The variation of the spillage with tower height, external cylindrical receiver size, dimensionless radial distance from the tower is computed and plotted. The value of the rated MW energy absorbed by an external cylindrical receiver, is investigated, and its relations to the tower height, the site location and the field radius are given. The effect of changing the radial spacing on the rated MW and the total number of heliostats in the field is also computed and depicted. The developed set of charts for the spillage factor are believed to be very useful for solar central receiver system design. (author) 7 figs., 21 refs.

  19. UWB communication receiver feedback loop

    Science.gov (United States)

    Spiridon, Alex; Benzel, Dave; Dowla, Farid U.; Nekoogar, Faranak; Rosenbury, Erwin T.

    2007-12-04

    A novel technique and structure that maximizes the extraction of information from reference pulses for UWB-TR receivers is introduced. The scheme efficiently processes an incoming signal to suppress different types of UWB as well as non-UWB interference prior to signal detection. Such a method and system adds a feedback loop mechanism to enhance the signal-to-noise ratio of reference pulses in a conventional TR receiver. Moreover, sampling the second order statistical function such as, for example, the autocorrelation function (ACF) of the received signal and matching it to the ACF samples of the original pulses for each transmitted bit provides a more robust UWB communications method and system in the presence of channel distortions.

  20. Software Defined DCF77 Receiver

    OpenAIRE

    F. Zaplata; M. Kasal

    2013-01-01

    This paper shows the solution of time stamp software defined receiver integration into low cost com-mercial devices. The receiver is based on a general pur-pose processor and its analog to digital converter. The amplified signal from a narrow-band antenna is connected to the converter and no complicated filtration has to be used. All signal processing is digitally provided by the processor. During signal reception, the processor stays available for its main tasks and signal processing con-sum...

  1. Software Defined DCF77 Receiver

    Directory of Open Access Journals (Sweden)

    F. Zaplata

    2013-12-01

    Full Text Available This paper shows the solution of time stamp software defined receiver integration into low cost com-mercial devices. The receiver is based on a general pur-pose processor and its analog to digital converter. The amplified signal from a narrow-band antenna is connected to the converter and no complicated filtration has to be used. All signal processing is digitally provided by the processor. During signal reception, the processor stays available for its main tasks and signal processing con-sumes only a small part of its computational power.

  2. Veterans Affairs Central Cancer Registry (VACCR)

    Data.gov (United States)

    Department of Veterans Affairs — The Veterans Affairs Central Cancer Registry (VACCR) receives and stores information on cancer diagnosis and treatment constraints compiled and sent in by the local...

  3. RFID receiver apparatus and method

    Science.gov (United States)

    Scott, Jeffrey Wayne

    2006-12-26

    An RFID backscatter interrogator for transmitting data to an RFID tag, generating a carrier for the tag, and receiving data from the tag modulated onto the carrier, the interrogator including a single grounded-coplanar wave-guide circuit board and at least one surface mount integrated circuit supported by the circuit board.

  4. LU Peizhang receives Golay Award

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Prof. LU Peizhang, an analytical chemist with the CAS Dalian Institute of Chemical Physics, received the prestigious Golay Award at the 30th International Symposium on Capillary Chromatography opened on 5 June in Dalian, a port city in northeast China's Liaoning Province.

  5. Advances in SIS receiver technology

    Science.gov (United States)

    Frerking, M. A.

    1988-01-01

    Significant advances in SIS receiver technology since the last Asilomar meeting include: superconductor materials, integrated inductive tuning elements, and planar mounting structures. The effect of these advances is to push the upper frequency operating limit from about 600 to 1500 GHz, and to enhance the feasibility of focal plane arrays of heterodyne receivers. A fundamental high frequency operating limit of SIS mixers is set by the superconducting energy gap. A practical limitation for high frequency operation of SIS junctions is their parasitic capacitance and resistance. The performance of the mixer will be degraded by the Resistor-Capacitor rolloff. Several designs were reported for inductive elements integrated on the same substrate as the SIS junctions to tune out the bulk junction capacitance. Most millimeter SIS-based heterodyne receivers have used waveguide coupling structures. Technology has advanced to the state where programs that have a high probability of success can be defined to produce arrays of SIS receivers for frequencies as high as 1500 GHz.

  6. Converting accounts receivable into cash.

    Science.gov (United States)

    Folk, M D; Roest, P R

    1995-09-01

    In recent years, increasing numbers of healthcare providers have converted their accounts receivable into cash through a process called securitization. This practice has gained popularity because it provides a means to raise capital necessary to healthcare organizations. Although securitization transactions can be complex, they may provide increased financial flexibility to providers as they prepare for continuing change in the healthcare industry. PMID:10145096

  7. Femtosecond Photon-Counting Receiver

    Science.gov (United States)

    Krainak, Michael A.; Rambo, Timothy M.; Yang, Guangning; Lu, Wei; Numata, Kenji

    2016-01-01

    An optical correlation receiver is described that provides ultra-precise distance and/or time/pulse-width measurements even for weak (single photons) and short (femtosecond) optical signals. A new type of optical correlation receiver uses a fourth-order (intensity) interferometer to provide micron distance measurements even for weak (single photons) and short (femtosecond) optical signals. The optical correlator uses a low-noise-integrating detector that can resolve photon number. The correlation (range as a function of path delay) is calculated from the variance of the photon number of the difference of the optical signals on the two detectors. Our preliminary proof-of principle data (using a short-pulse diode laser transmitter) demonstrates tens of microns precision.

  8. Scintillation-Hardened GPS Receiver

    Science.gov (United States)

    Stephens, Donald R.

    2015-01-01

    CommLargo, Inc., has developed a scintillation-hardened Global Positioning System (GPS) receiver that improves reliability for low-orbit missions and complies with NASA's Space Telecommunications Radio System (STRS) architecture standards. A software-defined radio (SDR) implementation allows a single hardware element to function as either a conventional radio or as a GPS receiver, providing backup and redundancy for platforms such as the International Space Station (ISS) and high-value remote sensing platforms. The innovation's flexible SDR implementation reduces cost, weight, and power requirements. Scintillation hardening improves mission reliability and variability. In Phase I, CommLargo refactored an open-source GPS software package with Kalman filter-based tracking loops to improve performance during scintillation and also demonstrated improved navigation during a geomagnetic storm. In Phase II, the company generated a new field-programmable gate array (FPGA)-based GPS waveform to demonstrate on NASA's Space Communication and Navigation (SCaN) test bed.

  9. Customer experiences receiving investment services

    OpenAIRE

    Szepe, Sanna

    2015-01-01

    Today the customers are able to compare the products of the different services available easily and between service companies, the experience the customer receives has become more and more important. Banking services have experienced the same evolution than the other surrounding service companies, and the importance of more complicated advisory services is sought after, when simpler transactions are taken care by the customers themselves. Investment services are one of the highest profiti...

  10. The GBT 4mm Receiver

    Science.gov (United States)

    Frayer, David T.; White, S.; Watts, G.; Stennes, M.; Maddalena, R. J.; Simon, R.; Pospieszalski, M.; Bryerton, E.

    2013-01-01

    The new 4mm receiver (67--93 GHz) for the Robert C. Byrd Green Bank Telescope (GBT) was built to take advantage of the improved surface accuracy of the dish. The low frequency end of the 3mm atmospheric window is not available with ALMA (National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

  11. Diversity of MMSE MIMO Receivers

    CERN Document Server

    Mehana, Ahmed Hesham

    2011-01-01

    In most MIMO systems, the family of waterfall error curves, calculated at different spectral efficiencies, are asymptotically parallel at high SNR. In other words, most MIMO systems exhibit a single diversity value for all {\\em fixed} rates. The MIMO MMSE receiver does not follow this pattern and exhibits a varying diversity in its family of error curves. This effect cannot be captured by DMT analysis, due to the fact that all fixed rates correspond to the same multiplexing gain, thus they cannot be differentiated within DMT analysis. This work analyzes this interesting behavior of the MMSE MIMO receiver and produces the MMSE MIMO diversity at each rate. The diversity of the quasi-static flat-fading MIMO channel consisting of any arbitrary number of transmit and receive antennas is fully characterized, showing that full spatial diversity is possible for all antenna configurations if and only if the rate is within a certain bound which is a function of the number of antennas. For other rate brackets, the avail...

  12. central t

    Directory of Open Access Journals (Sweden)

    Manuel R. Piña Monarrez

    2007-01-01

    Full Text Available Dado que la Regresión Ridge (RR, es una estimación sesgada que parte de la solución de la regresión de Mínimos Cuadrados (MC, es vital establecer las condiciones para las que la distribución central t de Student que se utiliza en la prueba de hipótesis en MC, sea también aplicable a la regresión RR. La prueba de este importante resultado se presenta en este artículo.

  13. Vertebrate pressure-gradient receivers

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, Jakob

    2011-01-01

    . Recent vertebrates form a continuum from perfect interaural transmission (0 dB in a certain frequency band) and pronounced eardrum directionality (30-40 dB) in the lizards, over somewhat attenuated transmission and limited directionality in birds and frogs, to the strongly attenuated interaural...... transmission and functionally isolated pressure receiver ears in the mammals. Since some of the binaural interaction already takes place at the eardrum in animals with strongly coupled ears, producing enhanced interaural time and level differences, the subsequent neural processing may be simpler. In robotic...

  14. Chip Advancer For GPS Receiver

    Science.gov (United States)

    Meehan, Thomas K.; Srinivasan, Jeffrey M.; Thomas, J. Brooks

    1989-01-01

    Instrument errors made negligible. For each integration interval, both delay and rate of change of delay initialized to small fraction of chip - for example, to order of 10 to the negative 7th power - thereby making feedback control and extraction of delay highly accurate and flexible. With appropriate selection of sampling rate relative to chip rate, commensurability errors reduced to extremely small levels. In Global Positioning System (GPS) receiver, pseudorandom code sequence generated by simple digital logic incorporating effects of time, delay, and rate of change of delay. Flexibility in starting time and sum interval very useful in aligning correlation interval with beginnings and endings of data bits.

  15. Andrea Ghez Receives Crafoord Prize

    OpenAIRE

    Sher, Ben

    2012-01-01

    The Royal Swedish Academy of Scienceshas selected Andrea Ghez, a professor of physics and astronomy at UCLA, to receive the 2012 Crafoord Prize in Astronomy. She is being honored by the Academy for “observations of stars orbiting the Galactic center, indicating the presence of a supermassive black hole.” The Crafoord Prize, which includes an accompanying award of 4 million Swedish krona, is considered one of the world’s largest scientific prizes. Ghez is the first woman to win the award since...

  16. Absorption Efficiency of Receiving Antennas

    DEFF Research Database (Denmark)

    Andersen, Jørgen Bach; Frandsen, Aksel

    2005-01-01

    A receiving antenna with a matched load will always scatter some power. This paper sets an upper and a lower bound on the absorption efficiency (absorbed power over sum of absorbed and scattered powers), which lies between 0 and 100% depending on the directivities of the antenna and scatter...... patterns. It can approach 100% as closely as desired, although in practice this may not be an attractive solution. An example with a small endfire array of dipoles shows an efficiency of 93%. Several examples of small conical horn antennas are also given, and they all have absorption efficiencies less than...

  17. Communication received from South Africa

    International Nuclear Information System (INIS)

    The document reproduces the press release with a statement by Dr. J.W.L. de Villiers, Executive Chairman of the Atomic Energy Corporation of South Africa Limited, issued on 31 January 1984 and included in the letter received by the Director General of the IAEA from the Resident Representative of South Africa to the Agency on 31 January 1984. This statement refers to the transfer of nuclear material equipment and technology by South Africa to other countries and the Non-Proliferation Treaty

  18. Broadband direct RF digitization receivers

    CERN Document Server

    Jamin, Olivier

    2014-01-01

    This book discusses the trade-offs involved in designing direct RF digitization receivers for the radio frequency and digital signal processing domains.  A system-level framework is developed, quantifying the relevant impairments of the signal processing chain, through a comprehensive system-level analysis.  Special focus is given to noise analysis (thermal noise, quantization noise, saturation noise, signal-dependent noise), broadband non-linear distortion analysis, including the impact of the sampling strategy (low-pass, band-pass), analysis of time-interleaved ADC channel mismatches, sampling clock purity and digital channel selection. The system-level framework described is applied to the design of a cable multi-channel RF direct digitization receiver. An optimum RF signal conditioning, and some algorithms (automatic gain control loop, RF front-end amplitude equalization control loop) are used to relax the requirements of a 2.7GHz 11-bit ADC. A two-chip implementation is presented, using BiCMOS and 65nm...

  19. CERN physicist receives Einstein Medal

    CERN Multimedia

    2006-01-01

    On 29 June the CERN theorist Gabriele Veneziano was awarded the prestigious Albert Einstein Medal for significant contributions to the understanding of string theory. This award is given by the Albert Einstein Society in Bern to individuals whose scientific contributions relate to the work of Einstein. Former recipients include exceptional physicists such as Murray Gell-Mann last year, but also Stephen Hawking and Victor Weisskopf. Gabriele Veneziano, a member of the integrated CERN Theory Team since 1977, led the Theory Division from 1994 to 1997 and has already received many prestigious prizes for his outstanding work, including the Enrico Fermi Prize (see CERN Courier, November 2005), the Dannie Heineman Prize for mathematical physics of the American Physical Society in 2004 (see Bulletin No. 47/2003), and the I. Ya. Pomeranchuk Prize of the Institute of Theoretical and Experimental Physics (Moscow) in 1999.

  20. Receive channel architecture and transmission system for digital array radar

    OpenAIRE

    Yong, Yoke Chuang

    2005-01-01

    An â opportunistic arrayâ is a new digital antenna concept where phased array elements are placed at available open areas over the entire length of the platform. The elements are self-standing transmit-receive modules that require no hardwire connections other than prime power. All synchronization signals and data are passed wirelessly between the elements and a central signal processor. An opportunistic array that is integrated into the hull or superstructure of the warship is called an â...

  1. A Digital-Receiver for the Murchison Widefield Array

    CERN Document Server

    Prabu, Thiagaraj; Roshi, D Anish; Kamini, P A; Madhavi, S; Emrich, David; Crosse, Brian; Williams, Andrew J; Waterson, Mark; Deshpande, Avinash A; Shankar, N Udaya; Subrahmanyan, Ravi; Briggs, Frank H; Goeke, Robert F; Tingay, Steven J; Johnston-Hollitt, Melanie; R, Gopalakrishna M; Morgan, Edward H; Pathikulangara, Joseph; Bunton, John D; Hampson, Grant; Williams, Christopher; Ord, Stephen M; Wayth, Randall B; Kumar, Deepak; Morales, Miguel F; deSouza, Ludi; Kratzenberg, Eric; Pallot, D; McWhirter, Russell; Hazelton, Bryna J; Arcus, Wayne; Barnes, David G; Bernardi, Gianni; Booler, T; Bowman, Judd D; Cappallo, Roger J; Corey, Brian E; Greenhill, Lincoln J; Herne, David; Hewitt, Jacqueline N; Kaplan, David L; Kasper, Justin C; Kincaid, Barton B; Koenig, Ronald; Lonsdale, Colin J; Lynch, Mervyn J; Mitchell, Daniel A; Oberoi, Divya; Remillard, Ronald A; Rogers, Alan E; Salah, Joseph E; Sault, Robert J; Stevens, Jamie B; Tremblay, S E; Webster, Rachel L; Whitney, Alan R; Wyithe, Stuart B

    2015-01-01

    An FPGA-based digital-receiver has been developed for a low-frequency imaging radio interferometer, the Murchison Widefield Array (MWA). The MWA, located at the Murchison Radio-astronomy Observatory (MRO) in Western Australia, consists of 128 dual-polarized aperture-array elements (tiles) operating between 80 and 300\\,MHz, with a total processed bandwidth of 30.72 MHz for each polarization. Radio-frequency signals from the tiles are amplified and band limited using analog signal conditioning units; sampled and channelized by digital-receivers. The signals from eight tiles are processed by a single digital-receiver, thus requiring 16 digital-receivers for the MWA. The main function of the digital-receivers is to digitize the broad-band signals from each tile, channelize them to form the sky-band, and transport it through optical fibers to a centrally located correlator for further processing. The digital-receiver firmware also implements functions to measure the signal power, perform power equalization across ...

  2. Orexin neurons receive glycinergic innervations.

    Directory of Open Access Journals (Sweden)

    Mari Hondo

    Full Text Available Glycine, a nonessential amino-acid that acts as an inhibitory neurotransmitter in the central nervous system, is currently used as a dietary supplement to improve the quality of sleep, but its mechanism of action is poorly understood. We confirmed the effects of glycine on sleep/wakefulness behavior in mice when administered peripherally. Glycine administration increased non-rapid eye movement (NREM sleep time and decreased the amount and mean episode duration of wakefulness when administered in the dark period. Since peripheral administration of glycine induced fragmentation of sleep/wakefulness states, which is a characteristic of orexin deficiency, we examined the effects of glycine on orexin neurons. The number of Fos-positive orexin neurons markedly decreased after intraperitoneal administration of glycine to mice. To examine whether glycine acts directly on orexin neurons, we examined the effects of glycine on orexin neurons by patch-clamp electrophysiology. Glycine directly induced hyperpolarization and cessation of firing of orexin neurons. These responses were inhibited by a specific glycine receptor antagonist, strychnine. Triple-labeling immunofluorescent analysis showed close apposition of glycine transporter 2 (GlyT2-immunoreactive glycinergic fibers onto orexin-immunoreactive neurons. Immunoelectron microscopic analysis revealed that GlyT2-immunoreactive terminals made symmetrical synaptic contacts with somata and dendrites of orexin neurons. Double-labeling immunoelectron microscopy demonstrated that glycine receptor alpha subunits were localized in the postsynaptic membrane of symmetrical inhibitory synapses on orexin neurons. Considering the importance of glycinergic regulation during REM sleep, our observations suggest that glycine injection might affect the activity of orexin neurons, and that glycinergic inhibition of orexin neurons might play a role in physiological sleep regulation.

  3. Structuring a sound securitization of healthcare receivables.

    Science.gov (United States)

    Spradling, Mark

    2003-02-01

    Securitization of receivables allows healthcare providers to obtain an additional funding source by selling their accounts receivables to investors. A double-lock-box structure allows providers to securitize Medicare and Medicaid receivables without violating federal laws. A 2001 revision to the Uniform Commercial Code facilitates providers' securitization of private healthcare insurance receivables by underscoring rights of a purchaser of those receivables. HIPAA privacy standards appear to permit the use and disclosure of protected health information in crafting a securitization program. The securitization should be structured to shield the value of the receivables to be transferred from the potential backruptcies of the originator and the purchaser. PMID:12602313

  4. Microwave receivers with electronic warfare applications

    CERN Document Server

    Tsui, James

    2005-01-01

    This book by the author of Digital Techniques for Wideband Receivers willbe like no other one on your book shelf as the definitive word on electronicwarfare (EW) receiver design and performance. Whether you are an EWscientist involved in the test and evaluation of EW receivers or a designerof RWR's and other EW-related receivers, Microwave Receivers withElectronic Warfare Applications is a handy reference through which you canperfect your technical art. Lucidly written, this book is a treatise on EWreceivers that is relevant to you if you are just looking for a top-levelinsight into EW receive

  5. The First Six ALMA Band 10 Receivers

    Science.gov (United States)

    Fujii, Y.; Gonzalez, A.; Kroug, M.; Kaneko, K.; Miyachi, A.; Yokoshima, T.; Kuroiwa, K.; Ogawa, H.; Makise, K.; Wang, Z.; Uzawa, Y.

    2013-01-01

    The first six Atacama Large Millimeter/submillimeter Array (ALMA) Band 10 (787-950 GHz) receivers have been developed and characterized during the receiver preproduction phase. State-of-the-art measurement systems at THz frequencies have been implemented and successfully used to measure the performance of the first six receivers. Extensive tests ranging from receiver sensitivity and stability to optical aperture efficiency on the secondary antenna have been performed. Performance of all six receivers is well within the stringent ALMA requirements. Moreover, our extensive tests have shown that there are no big performance differences between receivers. These results indicate that the ALMA Band 10 receiver is ready for the production phase, during which an additional 67 receivers will be produced and characterized.

  6. The lithosphere-asthenosphere boundary observed with USArray receiver functions

    Directory of Open Access Journals (Sweden)

    P. Kumar

    2012-01-01

    Full Text Available The dense deployment of seismic stations so far in the western half of the United States within the USArray project provides the opportunity to study in greater detail the structure of the lithosphere-asthenosphere system. We use the S receiver function technique for this purpose which has higher resolution than surface wave tomography, is sensitive to seismic discontinuities and has no problems with multiples like P receiver functions. Only two major discontinuities are observed in the entire area down to about 300 km depth. These are the crust-mantle boundary (Moho and a negative boundary which we correlate with the lithosphere-asthenosphere boundary (LAB since a low velocity zone is the classical definition of the seismic observation of the asthenosphere by Gutenberg (1926. Our S receiver function LAB is at a depth of 70–80 km in large parts of westernmost North America. East of the Rocky Mountains its depth is generally between 90 and 110 km. Regions with LAB depths down to about 140 km occur in a stretch from northern Texas over the Colorado Plateau to the Columbia Basalts. These observations agree well with tomography results in the westernmost USA and at the east coast. However, in the central cratonic part of the USA the tomography LAB is near 200 km depth. At this depth no discontinuity is seen in the S receiver functions. The negative signal near 100 km depth in the central part of the USA is interpreted by Yuan and Romanowicz (2010 or Lekic and Romanowicz (2011 as a recently discovered mid lithospheric discontinuity (MLD. A solution for the discrepancy between receiver function imaging and surface wave tomography is not yet obvious and requires more high resolution studies at other cratons before a general solution may be found. Our results agree well with petrophysical models of increased water content in the asthenosphere, which predict a sharp and shallow LAB also in continents (Mierdel et al., 2007.

  7. The lithosphere-asthenosphere boundary observed with USArray receiver functions

    Directory of Open Access Journals (Sweden)

    P. Kumar

    2012-05-01

    Full Text Available The dense deployment of seismic stations so far in the western half of the United States within the USArray project provides the opportunity to study in greater detail the structure of the lithosphere-asthenosphere system. We use the S receiver function technique for this purpose, which has higher resolution than surface wave tomography, is sensitive to seismic discontinuities, and is free from multiples, unlike P receiver functions. Only two major discontinuities are observed in the entire area down to about 300 km depth. These are the crust-mantle boundary (Moho and a negative boundary, which we correlate with the lithosphere-asthenosphere boundary (LAB, since a low velocity zone is the classical definition of the seismic observation of the asthenosphere by Gutenberg (1926. Our S receiver function LAB is at a depth of 70–80 km in large parts of westernmost North America. East of the Rocky Mountains, its depth is generally between 90 and 110 km. Regions with LAB depths down to about 140 km occur in a stretch from northern Texas, over the Colorado Plateau to the Columbia basalts. These observations agree well with tomography results in the westernmost USA and on the east coast. However, in the central cratonic part of the USA, the tomography LAB is near 200 km depth. At this depth no discontinuity is seen in the S receiver functions. The negative signal near 100 km depth in the central part of the USA is interpreted by Yuan and Romanowicz (2010 and Lekic and Romanowicz (2011 as a recently discovered mid-lithospheric discontinuity (MLD. A solution for the discrepancy between receiver function imaging and surface wave tomography is not yet obvious and requires more high resolution studies at other cratons before a general solution may be found. Our results agree well with petrophysical models of increased water content in the asthenosphere, which predict a sharp and shallow LAB also in continents (Mierdel et al., 2007.

  8. 49 CFR 393.88 - Television receivers.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Television receivers. 393.88 Section 393.88... NECESSARY FOR SAFE OPERATION Miscellaneous Parts and Accessories § 393.88 Television receivers. Any motor vehicle equipped with a television viewer, screen or other means of visually receiving a...

  9. 49 CFR 236.730 - Coil, receiver.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Coil, receiver. 236.730 Section 236.730 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Coil, receiver. Concentric layers of insulated wire wound around the core of a receiver of an...

  10. Receiver Function Estimated by Wiener Filtering

    Institute of Scientific and Technical Information of China (English)

    Wu Qingju; Tian Xiaobo; Zhang Nailing; Li Weiping; Zeng Rongsheng

    2003-01-01

    Wiener filtering is used to estimate receiver function in a time-domain. With the vertical component of 3-component teleseismic P waveform as the input of a Wiener filter, receiver function as the filter response, and radial and tangential components as the expected output,receiver function is estimated by minimizing the error between expected and actual outputs.Receiver function can be obtained by solving the Toeplitz equation using the Levinson algorithm. The non-singularity of the Toeplitz equation ensures the stability of Wiener Deconvolution. Both synthetic and observational seismogram cheeks show that Wiener Deconvolution is an effective time-domain method to estimate receiver function from teleseismic P waveform.

  11. A zero-power radio receiver.

    Energy Technology Data Exchange (ETDEWEB)

    Brocato, Robert Wesley

    2004-09-01

    This report describes both a general methodology and some specific examples of passive radio receivers. A passive radio receiver uses no direct electrical power but makes sole use of the power available in the radio spectrum. These radio receivers are suitable as low data-rate receivers or passive alerting devices for standard, high power radio receivers. Some zero-power radio architectures exhibit significant improvements in range with the addition of very low power amplifiers or signal processing electronics. These ultra-low power radios are also discussed and compared to the purely zero-power approaches.

  12. Sensitivity modeling of binary optical receivers.

    Science.gov (United States)

    Giggenbach, Dirk; Mata-Calvo, Ramon

    2015-10-01

    The sensitivity characteristics of optical receiver frontends for high-speed data communications depend on modulation format, detector type, and specific operational constraints. A general mathematical model of the receiver sensitivity that fits to analytical as well as measured data is required to compare different receiver implementations and assess the reliability of data links under varying received power as common in free-space optical communication links. In this paper, a new approach based on Q-factor modeling is presented, compared with analytical receiver models, and applied to a multitude of exemplary receiver implementations. A methodology is introduced to generally apply the model to ideal or practical binary optical receiver frontends. PMID:26479592

  13. Astronomical Receiver Modelling Using Scattering Matrices

    CERN Document Server

    King, O G; Copley, C; Davis, R J; Leahy, J P; Leech, J; Muchovej, S J C; Pearson, T J; Taylor, Angela C

    2014-01-01

    Proper modelling of astronomical receivers is vital: it describes the systematic errors in the raw data, guides the receiver design process, and assists data calibration. In this paper we describe a method of analytically modelling the full signal and noise behaviour of arbitrarily complex radio receivers. We use electrical scattering matrices to describe the signal behaviour of individual components in the receiver, and noise correlation matrices to describe their noise behaviour. These are combined to produce the full receiver model. We apply this approach to a specified receiver architecture: a hybrid of a continous comparison radiometer and correlation polarimeter designed for the C-Band All-Sky Survey. We produce analytic descriptions of the receiver Mueller matrix and noise temperature, and discuss how imperfections in crucial components affect the raw data. Many of the conclusions drawn are generally applicable to correlation polarimeters and continuous comparison radiometers.

  14. Central Pain Syndrome

    Science.gov (United States)

    ... Enhancing Diversity Find People About NINDS NINDS Central Pain Syndrome Information Page Table of Contents (click to ... being done? Clinical Trials Organizations What is Central Pain Syndrome? Central pain syndrome is a neurological condition ...

  15. Central venous line - infants

    Science.gov (United States)

    CVL - infants; Central catheter - infants - surgically placed ... plastic tube that is put into a large vein in the chest. WHY IS A ... central catheter (PICC) or midline central catheter (MCC). A CVL ...

  16. Cryptographic Defence against Misbehaving TCP Receivers

    CERN Document Server

    Chan, Aldar C-F

    2008-01-01

    The congestion control algorithm in TCP relies on {\\em correct} feedback from the receiver to determine the rate at which packets should be sent into the network. Hence, correct receiver feedback (in the form of acknowledgements in TCP) is essential to the goal of sharing the scarce bandwidth resources fairly and avoiding congestion collapse in the Internet. However, the assumption that a TCP receiver can always be trusted (to generate feedback correctly) no longer holds as there are plenty of incentives for a receiver to deviate from the protocol. In fact, it has been shown that a misbehaving receiver (whose aim is to bring about congestion collapse) can easily generate acknowledgements to conceal loss and drive a number of honest, innocent senders arbitrary fast to create a significant number of non-responsive packet flows leading to denial of service to other Internet users. We give two efficient, provably secure mechanisms to force a receiver to generate feedback correctly; any incorrect acknowledgement w...

  17. Analysis of the omnium-g receiver

    Energy Technology Data Exchange (ETDEWEB)

    Bohn, M.

    1980-03-01

    A thermal analysis of the Omnium-G receiver is presented and the technique is shown to be generally applicable to solar thermal receivers utilizing a directly heated thermal mass. The thermal loss coefficient, including reradiation losses, is calculated and shown to agree quite well with the experimentally measured thermal loss coefficient. The rate of heat transfer to the working fluid is also analyzed and the analysis is used to show that the Omnium-G receiver is well matched to the water/steam working fluid because the steam outlet temperature is almost the same as the receiver temperature. A general procedure for calculating receiver performance is presented. With this procedure, the energy delivery to any working fluid, the delivered temperature of the working fluid, and the pressure drop through the receiver can be determined. An example of the calculation is also presented.

  18. Interference Channels with Correlated Receiver Side Information

    OpenAIRE

    Liu, Nan; Gunduz, Deniz; Goldsmith, Andrea J.; Poor, H. Vincent

    2008-01-01

    The problem of joint source-channel coding in transmitting independent sources over interference channels with correlated receiver side information is studied. When each receiver has side information correlated with its own desired source, it is shown that source-channel code separation is optimal. When each receiver has side information correlated with the interfering source, sufficient conditions for reliable transmission are provided based on a joint source-channel coding scheme using the ...

  19. High-stability detectors for radioastronomical receivers

    Science.gov (United States)

    Teuber, Ute; Schmidt, Axel

    The increased bandwidths of radioastronomical receivers has increased the detector stability requirements. A detector with a short-term stability of 0.01 percent, required in a receiver with a 9 mm wavelength receiver, could not be achieved using previously available detectors and dc amplifiers. This paper describes a switched detector which meets these requirements, and presents resulting rms values as a function of integration time.

  20. Nursing process approach improves receivables management.

    Science.gov (United States)

    Dias, K; Stockamp, D

    1992-09-01

    The "nursing process" is a systematic decision-making approach to problem solving based on open-system theory. This theory assumes that there is an on-going interchange between all system components. Components cannot be viewed in isolation, because decisions regarding one component will affect other components. Receivables management is similar to the nursing process, in that it involves constant diagnosis, assessment, and intervention in the work in process during all phases of the receivables cycle. In experiments that applied the nursing process concept to the management of accounts receivable in several hospitals, gross days in accounts receivable were reduced and cash flow was increased. PMID:10145682

  1. Efficient structures for wideband digital receiver

    Institute of Scientific and Technical Information of China (English)

    Wang Hong; Lu Youxin; Wang Xuegang; Wan Yonglun

    2006-01-01

    Digital receivers have become more and more popular in radar, communication, and electric warfare for the advantages compared with their analog counterparts. But conventional digital receivers have been generally considered impractical for bandwidth greater than several hundreds MHz. To extend receiver bandwidth, decrease data rate and save hardware resources, three novel structures are proposed. They decimate the data stream prior to mixing and filtering, then process the multiple decimated streams in parallel at a lower rate. Consequently it is feasible to realize wideband receivers on the current ASIC devices. A design example and corresponding simulation results are demonstrated to evaluate the proposed structures.

  2. Receiver function estimated by maximum entropy deconvolution

    Institute of Scientific and Technical Information of China (English)

    吴庆举; 田小波; 张乃铃; 李卫平; 曾融生

    2003-01-01

    Maximum entropy deconvolution is presented to estimate receiver function, with the maximum entropy as the rule to determine auto-correlation and cross-correlation functions. The Toeplitz equation and Levinson algorithm are used to calculate the iterative formula of error-predicting filter, and receiver function is then estimated. During extrapolation, reflective coefficient is always less than 1, which keeps maximum entropy deconvolution stable. The maximum entropy of the data outside window increases the resolution of receiver function. Both synthetic and real seismograms show that maximum entropy deconvolution is an effective method to measure receiver function in time-domain.

  3. Special design topics in digital wideband receivers

    CERN Document Server

    Tsui, James B Y

    2009-01-01

    Offering engineers a thorough examination of special, more advanced aspects of digital wideband receiver design, this practical book builds on fundamental resources on the topic, helping you gain a more comprehensive understanding of the subject. This in-depth volume presents a detailed look at a complete receiver design, including the encoder. Moreover, it discusses the detection of exotic signals and provides authoritative guidance on designing receivers used in electronic warfare. From frequency modulation and biphase shifting keys, to parameter encoders in electronic warfare receivers and

  4. Hybrid Microoptical WDM Receiver for PON Communication

    Directory of Open Access Journals (Sweden)

    Vitezslav Jerabek

    2012-01-01

    Full Text Available The paper presents the design, simulation and construction results of the wavelength division multiplex (WDM optical hybrid receiver module for the passive optical network (PON. The optical WDM receiver was constructed using system of three micromodules in the new circle topology. The optical micromodule contains multimode fiber pigtail 50/125 µm, VHGT filter with collimation lens and two microwave optoelectronics receiver micromodules (OE receiver micromodules. OE receiver micromodules were designed by use small signal equivalent electrical circuit model and noise model, from which the mathematically solved the transmittance function, which was used for calculation and simulation of the optimal frequency characteristics and signal to noise ratio. For determine the limit frequency of OE receiver micromodule, the transcendent equation with transmittance function was numerically solved. OE receiver micromodule was composed of decollimation lenses and microwave optoelectronics receivers with bandwidth 2,5 GHz and alternatively in SMD technology with bandwidth 1,25 GHz, using the thin layer hybrid technology. WDM receiver use radiation 1490 nm for internet and 1550 nm for digital TV signals download information.

  5. To centralize or not to centralize?

    OpenAIRE

    Campbell, Andrew; Kunisch, Sven; Müller-Stewens, Günter

    2011-01-01

    The CEO's dilemma-were the gains of centralization worth the pain it could cause?-is a perennial one. Business leaders dating back at least to Alfred Sloan, who laid out GM's influential philosophy of decentralization in a series of memos during the 1920s, have recognized that badly judged centralization can stifle initiative, constrain the ability to tailor products and services locally, and burden business divisions with high costs and poor service.1 Insufficient centralization can deny bus...

  6. A centralized audio presentation manager

    Energy Technology Data Exchange (ETDEWEB)

    Papp, A.L. III; Blattner, M.M.

    1994-05-16

    The centralized audio presentation manager addresses the problems which occur when multiple programs running simultaneously attempt to use the audio output of a computer system. Time dependence of sound means that certain auditory messages must be scheduled simultaneously, which can lead to perceptual problems due to psychoacoustic phenomena. Furthermore, the combination of speech and nonspeech audio is examined; each presents its own problems of perceptibility in an acoustic environment composed of multiple auditory streams. The centralized audio presentation manager receives abstract parameterized message requests from the currently running programs, and attempts to create and present a sonic representation in the most perceptible manner through the use of a theoretically and empirically designed rule set.

  7. Design and implementation of the CAPS receiver

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper, based on analyses of the Chinese Area Positioning System (CAPS) satellite (GEO satellite) resources and signal properties, the signal power at the port of the receiver antenna is estimated, and the implementation projects are presented for a switching band C to band L CAPS C/A code receiver integrated with GPS receiver suite and for a CAPS dual frequency P code receiver. A microstrip receiving antenna is designed with high sensitivity and wide beam orientation, the RF front end of the C/A code and P code receivers, and a processor is designed for the navigation baseband. A single frequency CAPS C/A code receiver and a CAPS dual frequency P code receiver are built at the same time. A software process flow is provided, and research on relatively key techniques is also conducted, such as signal searching, code loop and carrier loop algorithms, a height assistant algorithm, a dual frequency difference speed measurement technique, a speed measurement technique using a single frequency source with frequency assistance, and a CAPS time correcting algorithm, according to the design frame of the receiver hardware. Research results show that the static plane positioning accuracy of the CAPS C/A code receiver is 20.5-24.6 m, height accuracy is 1.2-12.8 m, speed measurement accuracy is 0.13-0.3 m/s, dynamic plane positioning accuracy is 24.4 m, height accuracy is 3.0 m, and speed measurement accuracy is 0.24 m/s. In the case of C/A code, the timing accuracy is 200 ns, and it is also shown that the positioning accuracy of the CAPS precise code receiver (1σ ) is 5 m from south to north, and 0.8 m from east to west. Finally, research on positioning accuracy is also conducted.

  8. Superconducting integrated submillimeter receiver for TELIS

    NARCIS (Netherlands)

    Koshelets, Valery P.; Ermakov, Andrey B.; Filippenko, Lyudmila V.; Khudchenko, Andrey V.; Kiselev, Oleg S.; Sobolev, Alexander S.; Torgashin, Mikhail Yu.; Yagoubov, Pavel A.; Hoogeveen, Ruud W. M.; Wild, Wolfgang

    2007-01-01

    In this report an overview of the results on the development of a single-chip superconducting integrated receiver for the Terahertz Limb Sounder (TELIS) balloon project intended to measure a variety of stratosphere trace gases is presented. The Superconducting Integrated Receiver (SIR) comprises in

  9. Superconducting chip receivers for imaging application

    NARCIS (Netherlands)

    Shitov, SV; Koshelets, VP; Ermakov, AB; Filippenko, LV; Baryshev, AM; Luinge, W; Gao, [No Value

    1999-01-01

    Experimental details of a unique superconducting imaging array receiver are discussed. Each pixel contains an internally pumped receiver chip mounted on the back of the elliptical microwave lens. Each chip comprises a quasi-optical SIS mixer integrated with a superconducting flux-flow oscillator (FF

  10. Heat-Energy Analysis for Solar Receivers

    Science.gov (United States)

    Lansing, F. L.

    1982-01-01

    Heat-energy analysis program (HEAP) solves general heat-transfer problems, with some specific features that are "custom made" for analyzing solar receivers. Can be utilized not only to predict receiver performance under varying solar flux, ambient temperature and local heat-transfer rates but also to detect locations of hotspots and metallurgical difficulties and to predict performance sensitivity of neighboring component parameters.

  11. RF performance of T-DAB receivers

    NARCIS (Netherlands)

    Schiphorst, R.; Potman, J.; Hofstra, K.L.; Cronie, H.S.; Slump, C.H.

    2008-01-01

    In every wireless system, the weakest link determines the performance of the network. In this paper the Radio Frequency (RF) performance of both band III and L-band Terrestrial Digital Audio Broadcasting (T-DAB) consumer receivers are discussed. The receivers have been tested based on the EN 50248 s

  12. Compressive Sensing for Spread Spectrum Receivers

    DEFF Research Database (Denmark)

    Fyhn, Karsten; Jensen, Tobias Lindstrøm; Larsen, Torben;

    2013-01-01

    to a decrease in the two design parameters. This paper investigates the use of Compressive Sensing (CS) in a general Code Division Multiple Access (CDMA) receiver. We show that when using spread spectrum codes in the signal domain, the CS measurement matrix may be simplified. This measurement scheme, named...... Compressive Spread Spectrum (CSS), allows for a simple, effective receiver design. Furthermore, we numerically evaluate the proposed receiver in terms of bit error rate under different signal to noise ratio conditions and compare it with other receiver structures. These numerical experiments show that though......With the advent of ubiquitous computing there are two design parameters of wireless communication devices that become very important: power efficiency and production cost. Compressive sensing enables the receiver in such devices to sample below the Shannon-Nyquist sampling rate, which may lead...

  13. Temperature influences in receiver clock modelling

    Science.gov (United States)

    Wang, Kan; Meindl, Michael; Rothacher, Markus; Schoenemann, Erik; Enderle, Werner

    2016-04-01

    In Precise Point Positioning (PPP), hardware delays at the receiver site (receiver, cables, antenna, …) are always difficult to be separated from the estimated receiver clock parameters. As a result, they are partially or fully contained in the estimated "apparent" clocks and will influence the deterministic and stochastic modelling of the receiver clock behaviour. In this contribution, using three years of data, the receiver clock corrections of a set of high-precision Hydrogen Masers (H-Masers) connected to stations of the ESA/ESOC network and the International GNSS Service (IGS) are firstly characterized concerning clock offsets, drifts, modified Allan deviations and stochastic parameters. In a second step, the apparent behaviour of the clocks is modelled with the help of a low-order polynomial and a known temperature coefficient (Weinbach, 2013). The correlations between the temperature and the hardware delays generated by different types of antennae are then analysed looking at daily, 3-day and weekly time intervals. The outcome of these analyses is crucial, if we intend to model the receiver clocks in the ground station network to improve the estimation of station-related parameters like coordinates, troposphere zenith delays and ambiguities. References: Weinbach, U. (2013) Feasibility and impact of receiver clock modeling in precise GPS data analysis. Dissertation, Leibniz Universität Hannover, Germany.

  14. Fundamentals of GPS Receivers A Hardware Approach

    CERN Document Server

    Doberstein, Dan

    2012-01-01

    While much of the current literature on GPS receivers is aimed at those intimately familiar with their workings, this volume summarizes the basic principles using as little mathematics as possible, and details the necessary specifications and circuits for constructing a GPS receiver that is accurate to within 300 meters. Dedicated sections deal with the features of the GPS signal and its data stream, the details of the receiver (using a hybrid design as exemplar), and more advanced receivers and topics including time and frequency measurements. Later segments discuss the Zarlink GPS receiver chip set, as well as providing a thorough examination of the TurboRogue receiver, one of the most accurate yet made. Guiding the reader through the concepts and circuitry, from the antenna to the solution of user position, the book’s deployment of a hybrid receiver as a basis for discussion allows for extrapolation of the core ideas to more complex, and more accurate designs. Digital methods are used, but any analogue c...

  15. Terahertz Array Receivers with Integrated Antennas

    Science.gov (United States)

    Chattopadhyay, Goutam; Llombart, Nuria; Lee, Choonsup; Jung, Cecile; Lin, Robert; Cooper, Ken B.; Reck, Theodore; Siles, Jose; Schlecht, Erich; Peralta, Alessandro; Thomas, Bertrand; Mehdi, Imran

    2011-01-01

    Highly sensitive terahertz heterodyne receivers have been mostly single-pixel. However, now there is a real need of multi-pixel array receivers at these frequencies driven by the science and instrument requirements. In this paper we explore various receiver font-end and antenna architectures for use in multi-pixel integrated arrays at terahertz frequencies. Development of wafer-level integrated terahertz receiver front-end by using advanced semiconductor fabrication technologies has progressed very well over the past few years. Novel stacking of micro-machined silicon wafers which allows for the 3-dimensional integration of various terahertz receiver components in extremely small packages has made it possible to design multi-pixel heterodyne arrays. One of the critical technologies to achieve fully integrated system is the antenna arrays compatible with the receiver array architecture. In this paper we explore different receiver and antenna architectures for multi-pixel heterodyne and direct detector arrays for various applications such as multi-pixel high resolution spectrometer and imaging radar at terahertz frequencies.

  16. Measurements of solar flux density distribution on a plane receiver due to a flat heliostat

    Energy Technology Data Exchange (ETDEWEB)

    Elsayed, M.M.; Fathalah, K.A.; Al-Rabghi, O.M. [King Abdulaziz Univ., Jeddah (Saudi Arabia)

    1995-06-01

    An experimental facility is designed and manufactured to measure the solar flux density distribution on a central flat receiver due to a single flat heliostat. The tracking mechanism of the heliostat is controlled by two stepping motors, one for tilt angle control and the other for azimuth angle control. A x-y traversing mechanism is also designed and mounted on a vertical central receiver plane, where the solar flux density is to be measured. A miniature solar sensor is mounted on the platform of the traversing mechanism, where it is used to measure the solar flux density distribution on the receiver surface. The sensor is connected to a data acquisition card in a host computer. The two stepping motors of the heliostat tracking mechanism and the two stepping motors of the traversing mechanism are all connected to a controller card in the same host computer. A software `TOWER` is prepared to let the heliostat track the sun, move the platform of the traversing mechanism to the points of a preselected grid, and to measure the solar flux density distribution on the receiver plane. Measurements are carried out using rectangular flat mirrors of different dimensions at several distances from the central receiver. Two types of images were identified on the receiver plane - namely, apparent (or visible) and mirror-reflected radiation images. Comparison between measurements and a mathematical model validates the mathematical model. 13 refs., 12 figs., 1 tab.

  17. Instrument access device used for laparoscopic surgery and surgical procedures, has instrument receiver that receives instrument, and connector extends between proximal element and instrument receiver

    OpenAIRE

    Bonadio, Frank; Vaugh, Trevor; McManus, Ronan; MacNally, Shane

    2011-01-01

    The instrument access device has a proximal element (25) for location externally of an opening into a body cavity. An instrument receiver (2) receives an instrument. A connector (20) extends between the proximal element and the first instrument receiver. An instrument receiver (3) receives an instrument, and a connector (21) extends between the proximal element and the instrument receiver.

  18. A 492 GHz cooled Schottky receiver for radio-astronomy

    Science.gov (United States)

    Hernichel, J.; Schieder, R.; Stutzki, J.; Vowinkel, B.; Winnewisser, G.; Zimmermann, Peter

    1992-01-01

    We developed a 492 GHz cooled GaAs Schottky receiver driven by a solid state local oscillator with a DSB noise temperature of 550 K measured at the telescope. The receiver-bandwidth is approx. equal to 1.0 GHz. Quasi-optical mirrors focus the sky and local oscillator radiation into the mixer. Stability analysis via the Allan variance method shows that the total system including a 1 GHz bandwidth acousto-optical spectrometer built in Cologne allows integration times up to 100 sec per half switching cycle. We successfully used the receiver at the KOSMA 3 m telescope on Gornergrat (3150m) located in the central Swiss Alps near Zermatt during January-February 1992 for observations of the 492 GHz, (CI) (3)P1 to (3)P0 fine structure line in several galactic sources. These observations confirm that Gornergrat is an excellent winter submillimeter site in accordance with previous predictions based on the atmospheric opacity from KOSMA 345 GHz measurements.

  19. Securitization of Receivables - An Analysis of the Inherent Risks

    Directory of Open Access Journals (Sweden)

    José Roberto Ferreira Savoia

    2009-06-01

    Full Text Available Securitization is a modality of structured finance which allows a company to raise funds based on its receivables through capital markets. In Brazil, securitization was developed mostly in the form of mutual funds - the FIDC, which raise money by issuing senior cotes for qualified investors, and subordinated cotes, usually bought by the company that originated the receivables. This paper evaluates the risk and return for both kinds of investors through a stochastic model with two main variables: interest rates and default rates. The model is still sensible to the characteristics of the fund, like the amount of subordinated cotes, the type of asset being securitized; and the amount of receivables in relation to the assets. Regarding the case of senior cotes, the risk of returns under the basic level of interest rates is highly improbable; and in the case of subordinated cotes, the risk of returns under the basic interest rate may be considered still low, due to the high spreads observed in the Brazilian financial market. The simulations indicated that under historically mean interest rate volatility the default rates are the main component of the total risk. Accordingly to the developed analysis of international standards of regulation, the Brazilian Central Bank imposes very strong capital requirements to banks that securitize their assets and purchase the corresponding subordinated cotes.

  20. Digital Signal Processing Based Biotelemetry Receivers

    Science.gov (United States)

    Singh, Avtar; Hines, John; Somps, Chris

    1997-01-01

    This is an attempt to develop a biotelemetry receiver using digital signal processing technology and techniques. The receiver developed in this work is based on recovering signals that have been encoded using either Pulse Position Modulation (PPM) or Pulse Code Modulation (PCM) technique. A prototype has been developed using state-of-the-art digital signal processing technology. A Printed Circuit Board (PCB) is being developed based on the technique and technology described here. This board is intended to be used in the UCSF Fetal Monitoring system developed at NASA. The board is capable of handling a variety of PPM and PCM signals encoding signals such as ECG, temperature, and pressure. A signal processing program has also been developed to analyze the received ECG signal to determine heart rate. This system provides a base for using digital signal processing in biotelemetry receivers and other similar applications.

  1. 21 CFR 1020.10 - Television receivers.

    Science.gov (United States)

    2010-04-01

    ... components of the receiver except that portion of the neck and socket of the cathode-ray tube which normally... of a circuit or shield component. The warning label shall include the specification of operating...

  2. Digital Receiver for Laser Imaging Radar

    Institute of Scientific and Technical Information of China (English)

    WANG Wei Ran; SUN Bing

    2004-01-01

    With the extension of the application domains for laser imaging radar,it is necessary to find a new technical way to obtain high technical performance and adaptive ability.In this paper,A new concept of digital receiver of laser imaging radar system is presented.This digital receiver is defined as a time varying parameter receiver which possesses large dynamics region and time domain filter.The receiver's mode,component structure as well as every function of its processing are described.The results and laboratorial data show the feasibility of digital reception.Also,it can exploit the inherent nature of laser imaging radar to obtain high probability of detection.

  3. Metal Mesh Filters for Terahertz Receivers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The technical objective of this SBIR program is to develop and demonstrate metal mesh filters for use in NASA's low noise receivers for terahertz astronomy and...

  4. Metal Mesh Filters for Terahertz Receivers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The best low-noise receiver solutions for frequencies above about 800 GHz rely on either a low-noise bolometric direct detector or a hot electron bolometric mixer....

  5. 49 CFR 236.788 - Receiver.

    Science.gov (United States)

    2010-10-01

    ... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.788 Receiver. A device on a locomotive, so placed that it is in position to be influenced inductively or actuated by...

  6. High-Rate Receiver Design Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose an initial architectural and preliminary hardware design study for a high-rate receiver capable of decoding modulation suites specified by CCSDS...

  7. Percentage of Surgical Patients Receiving Recommended Care

    Science.gov (United States)

    ... view charts and maps. State Percentage of Surgical Patients Receiving Recommended Care by ... U.S. Department of Health & Human Services — 200 Independence Avenue, S.W. — Washington, D.C. 20201

  8. Go International! Build a Simplified Shortwave Receiver

    Science.gov (United States)

    Homoly, Clarke

    2008-01-01

    This article presents a plan for building a shortwave receiver that is doable, educational and has reasonable performance. The project, says the author, can give students years of listening fun without a major financial investment. Potential project improvements are included.

  9. List of Nuclear Materials Licensing Actions Received

    Data.gov (United States)

    Nuclear Regulatory Commission — A catalog of all Materials Licensing Actions received for review. The catalog lists the name of the entity submitting the license application, their city and state,...

  10. Design and implementation of the CAPS receiver

    Institute of Scientific and Technical Information of China (English)

    HU YongHui; HUA Yu; HOU Lei; WEI JingFa; WU JianFeng

    2009-01-01

    In this paper,baaed on analyses of the Chinese Area Positioning System (CAPS) satellite (GEO satellite) resources and signal properties,the signal power at the port of the receiver antenna is estimated,and the implementation projects are presented for a switching band C to band L CAPS C/A code receiver integrated with GPS receiver suite and for a CAPS dual frequency P code receiver.A microstrip receiving antenna is designed with high sensitivity and wide beam orientation,the RF front end of the C/A code and P code receivers,and a processor is designed for the navigation baseband.A single frequency CAPS C/A code receiver and a CAPS dual frequency P code receiver are built at the same time.A software process flow is provided,and research on relatively key techniques is also conducted,such as signal searching,code loop and carrier loop algorithms,a height assistant algorithm,a dual frequency difference speed measurement technique,a speed measurement technique using a single frequency source with frequency assistance,and a CAPS time correcting algorithm,according to the design frame of the receiver hardware.Research results show that the static plane positioning accuracy of the CAPS C/A code receiver is 20.5-24.6 m,height accuracy is 1.2-12.8 m,speed measurement accuracy is 0.13-0.3 m/s,dynamic plane positioning accuracy is 24.4 m,height accuracy is 3.0 m,and speed measurement accuracy is 0.24 m/s.In the case of C/A code,the timing accuracy is 200 ha,and it is also shown that the positioning accuracy of the CAPS precise code receiver (1σ) is 5 m from south to north,and 0.8 m from east to west.Finally,research on positioning accuracy is also conducted.

  11. Comparing Drug Use between Welfare-Receiving Arrestees and Non-Welfare-Receiving Arrestees.

    Science.gov (United States)

    Yacoubian, George S., Jr.; Peters, Ronald J., Jr.; Urbach, Blake J.; Johnson, Regina J.

    2002-01-01

    Compares drug-positive rates between welfare-receiving arrestees, non-welfare receiving arrestees living below the poverty level, and non-welfare arrestees living above the poverty level. Welfare-receiving arrestees were more likely to be female, older, less educated, and to test positive for opiates and benzodiazepines than the other subgroups.…

  12. Nonuniform bandpass sampling in radio receivers

    OpenAIRE

    Sun, Yi-Ran

    2004-01-01

    As an interface between radio receiver front-ends and digital signal processing blocks, sampling devices play a dominant role in digital radio communications. As an interface between radio receiver front-ends and digital signal processing blocks, sampling devices play a dominant role in digital radio communications. Based on different sampling theorems (e.g., classic Shannon’s sampling theorem, Papoulis’ Generalized sampling theorem, bandpass sampling theory), signals are processed by the sam...

  13. Compressed Sensing-Based Direct Conversion Receiver

    OpenAIRE

    Pierzchlewski, Jacek; Arildsen, Thomas; Larsen, Torben

    2012-01-01

    Due to the continuously increasing computational power of modern data receivers it is possible to move more and more processing from the analog to the digital domain. This paper presents a compressed sensing approach to relaxing the analog filtering requirements prior to the ADCs in a direct conversion receiver. In the presented solution, the filtered down-convertedradio signals are randomly sampled with an average sampling frequency lower than its Nyquist rate, and then reconstructed in a DS...

  14. ITERATIVE RECEIVER FOR OFDM-SDMA SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Shan Shuwei; Luo Hanwen; Song Wentao

    2004-01-01

    An iterative receiver is proposed based on the EM (Expectation-Maximization)algorithm for an OFDM-SDMA (Orthogonal Frequency Division Multiplexing-Space Division Multiple Access) system. By using a few pilots in every OFDM symbol, both channel estimation and multiuser detection can be simultaneously obtained by iteration. The computer simulation results show this receiver can track channel variations and detect multiuser symbols for different number of users under time-varying multipath channels.

  15. Single-Receiver GPS Phase Bias Resolution

    Science.gov (United States)

    Bertiger, William I.; Haines, Bruce J.; Weiss, Jan P.; Harvey, Nathaniel E.

    2010-01-01

    Existing software has been modified to yield the benefits of integer fixed double-differenced GPS-phased ambiguities when processing data from a single GPS receiver with no access to any other GPS receiver data. When the double-differenced combination of phase biases can be fixed reliably, a significant improvement in solution accuracy is obtained. This innovation uses a large global set of GPS receivers (40 to 80 receivers) to solve for the GPS satellite orbits and clocks (along with any other parameters). In this process, integer ambiguities are fixed and information on the ambiguity constraints is saved. For each GPS transmitter/receiver pair, the process saves the arc start and stop times, the wide-lane average value for the arc, the standard deviation of the wide lane, and the dual-frequency phase bias after bias fixing for the arc. The second step of the process uses the orbit and clock information, the bias information from the global solution, and only data from the single receiver to resolve double-differenced phase combinations. It is called "resolved" instead of "fixed" because constraints are introduced into the problem with a finite data weight to better account for possible errors. A receiver in orbit has much shorter continuous passes of data than a receiver fixed to the Earth. The method has parameters to account for this. In particular, differences in drifting wide-lane values must be handled differently. The first step of the process is automated, using two JPL software sets, Longarc and Gipsy-Oasis. The resulting orbit/clock and bias information files are posted on anonymous ftp for use by any licensed Gipsy-Oasis user. The second step is implemented in the Gipsy-Oasis executable, gd2p.pl, which automates the entire process, including fetching the information from anonymous ftp

  16. NIDDK Central Repository

    Data.gov (United States)

    U.S. Department of Health & Human Services — The NIDDK Central Repository stores biosamples, genetic and other data collected in designated NIDDK-funded clinical studies. The purpose of the NIDDK Central...

  17. GPS Receiver Performance Inspection by Wavelet Transform

    Institute of Scientific and Technical Information of China (English)

    Xia Lin-yuan; Liu Jing-nan; Lu Liang-xi

    2003-01-01

    As a powerful analysis tool and the result of contemporary mathematics development, wavelet transform has shown its promising application potentials through the research in the paper. Three aspects regarding GPS receiver performance is tackled: cycle slip detection, receiver noise analysis and receiver channel bias inspection. Wavelet decomposition for double differential observation has demonstrated that this multi-level transform can reveal cycle slips as small as 0.5 cycles without any pre-adjustment processes or satellite orbit information, it can therefore be regarded as a 'geometry free' method. Based on property assumption of receiver noise, signal of noise serial is obtained at the high frequency scale in wavelet decomposition layers. This kind of noise influence on GPSb aseline result can be effectively eliminated by reconstruction process during wavelet reconstruction. Through observed data analysis, the transform has detected a kind of receiver channel bias that has not been completely removed by processing unit of GPS receiver during clock offset resetting operation. Thus the wavelet approach can be employed as a kind of system diagnosis in a generalized point of view.

  18. Central and peripheral demyelination

    OpenAIRE

    Man Mohan Mehndiratta; Natasha Singh Gulati

    2014-01-01

    Several conditions cause damage to the inherently normal myelin of central nervous system, perepheral nervous system or both central and perepheral nervous system and hence termed as central demyelinating diseases, perepheral demyelinating diseases and combined central and perepheral demyelinating diseases respectively. Here we analysed and foccused on the etiology, prevalance, incidence and age of these demyelinating disorders. Clinical attention and various diagnostic tests are needed to ad...

  19. Solitary Median Maxillary Central Incisor Versus Agenesis of the Maxillary Central Incisor.

    Science.gov (United States)

    de Carvalho, Fabrício Kitazono; Arid, Juliana; De Rossi, Andiara; Paula-Silva, Francisco W G; Nelson-Filho, Paulo

    2016-01-01

    A solitary median maxillary central incisor (SMMCI) is rare and affected individuals may carry a potentially serious condition known as SMMCI syndrome. However, many of these cases do not receive proper attention because they are misdiagnosed as agenesis of the maxillary central incisor. The purpose of this manuscript is to report two cases of children with only one maxillary central incisor and draw diagnostic differences between the entities. A correct diagnosis is very important because if an SMMCI is confirmed, the patient should be referred for genetic counseling. PMID:27098718

  20. Comparison of intelligence quotient in children surviving leukemia who received different prophylactic central nervous system treatments

    Directory of Open Access Journals (Sweden)

    Reisi Nahid

    2012-01-01

    Conclusion: We can that reveal that CNS prophylaxis treatment, especially the combined treatment, is associated with IQ score decline in ALL survivors. Therefore,a baseline and an annual assessment of their educational progress are suggested.

  1. Combined cycle solar central receiver hybrid power system study. Volume III. Appendices. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-11-01

    A design study for a 100 MW gas turbine/steam turbine combined cycle solar/fossil-fuel hybrid power plant is presented. This volume contains the appendices: (a) preconceptual design data; (b) market potential analysis methodology; (c) parametric analysis methodology; (d) EPGS systems description; (e) commercial-scale solar hybrid power system assessment; and (f) conceptual design data lists. (WHK)

  2. Solar central receiver prototype heliostat CDRL item B. b. Technical progress report: interim

    Energy Technology Data Exchange (ETDEWEB)

    Easton, C. R.

    1978-03-01

    The objectives of this program are to establish a heliostat design with the associated manufacturing, assembly, installation and maintenance approaches that will: (1) yield a significant reduction of capital and operating costs; (2) meet performance specifications for large collector subsystems; and (3) can be produced and deployed throughout the southwestern United States. In addition, cost plans and schedules to develop, fabricate, and operate the heliostat are to be developed. This volume presents the collector design, including trade study and test results, and the manufacturing, installation and checkout, and operations and maintenance concepts. Also, a discussion of specification verification and optimization is included. (WHK)

  3. Software/firmware design specification for 10-MWe solar-thermal central-receiver pilot plant

    Energy Technology Data Exchange (ETDEWEB)

    Ladewig, T.D.

    1981-03-01

    The software and firmware employed for the operation of the Barstow Solar Pilot Plant are completely described. The systems allow operator control of up to 2048 heliostats, and include the capability of operator-commanded control, graphic displays, status displays, alarm generation, system redundancy, and interfaces to the Operational Control System, the Data Acquisition System, and the Beam Characterization System. The requirements are decomposed into eleven software modules for execution in the Heliostat Array Controller computer, one firmware module for execution in the Heliostat Field Controller microprocessor, and one firmware module for execution in the Heliostat Controller microprocessor. The design of the modules to satisfy requirements, the interfaces between the computers, the software system structure, and the computers in which the software and firmware will execute are detailed. The testing sequence for validation of the software/firmware is described. (LEW)

  4. Central-receiver solar-thermal power system. Collector subsystem research experiments detail design report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1976-02-24

    The detail design (DD) of research experiment hardware for the collector subsystem (heliostats) to support the 10 MW/sub e/ Pilot Plant preliminary design (PD) is presented. Additionally, test plans for assembly, integration, and array tests are presented, along with results of completed component/material tests. Research experiment DD and tests described were planned to provide design verification and supporting data, with hardware which either duplicates, or closely simulates the Pilot Plant PD baseline. (WHK)

  5. 10-MWe solar-thermal central-receiver pilot plant. Operating and maintenance manual

    Energy Technology Data Exchange (ETDEWEB)

    1979-08-01

    Information required to perform the initial program loading and operation of the Heliostat Array Controller (HAC) is provided. Operating activities are described as required for heliostat control. All computer console command steps, from power up to power down are described. Detailed steps are provided to wake up the system and direct heliostat beams to standby, on target, standby to stow and power down. Maintenance requirements (preventive and corrective), reparability (reparable - non-reparable decisions), spares identification, spares storage location, replacement levels, replacement location and repair location are established. Individual system breakdown block diagrams are provided for each system/assembly/subassembly. Maintenance and repair description sheets are provided for each maintenance significant item. The manual provides support of the following equipment: (a) helostat assembly; (b) heliostat control assembly; and (c) maintenance and installation equipment. The safety requirements for the operating and maintenance functions are established. These procedures will assist in eliminating or controlling the accident potentials caused by human error, environment, or component malfunctions or interactions that could result in major injury or fatality to operating or visiting personnel, or damage to subsystem components or support equipment. These procedures are for normal and test operating conditions and emergency situations, and apply to all Martin Marietta Corporation, governmental, operating and visitor personnel. (LEW)

  6. Infrared Sensor For Remote Temperature Monitoring Of Solar Thermal Central Receivers

    Science.gov (United States)

    Warren, David W.

    1983-07-01

    At the Barstow 10MW Solar Thermal Pilot Plant, water is converted to high pressure steam by concentrated solar radiation. The design of the elements in which the boiling takes place makes them vulnerable to blockage by particulates contaminating the circulating water. Concern over the potential for heat damage to blocked boiler elements has led to the development of a remote optical monitoring system for use at the Pilot Plant. The system employs a telescope and infrared vidicon to detect the increased blackbody radiant emittance produced by an overheated element. An image is provided with spatial and thermal resolution sufficient to detect and identify a single blocked element. Design considerations for such a system are discussed, as are performance at the Pilot Plant and possible extensions of the system to more sophisticated pyrometric tasks.

  7. Preliminary design of the Carrisa Plains solar central receiver power plant. Volume II. Plant specifications

    Energy Technology Data Exchange (ETDEWEB)

    Price, R. E.

    1983-12-31

    The specifications and design criteria for all plant systems and subsystems used in developing the preliminary design of Carrisa Plains 30-MWe Solar Plant are contained in this volume. The specifications have been organized according to plant systems and levels. The levels are arranged in tiers. Starting at the top tier and proceeding down, the specification levels are the plant, system, subsystem, components, and fabrication. A tab number, listed in the index, has been assigned each document to facilitate document location.

  8. Multi-Mode FMCW Radar Array with Independent Digital Beam Steering for Transmit and Receive

    NARCIS (Netherlands)

    Dijk, R. van; Houwen, E.H. van der; Maas, A.P.M.

    2008-01-01

    A phased-array FMCW radar has been design and built from COTS components. The generation of the frequency sweep is done by mixing a central local oscillator signal with a baseband sweep of a direct digital synthesizer (DDS). To ensure maximum flexibility the receive side has been equipped with it's

  9. Sexual function in women receiving maintenance dialysis.

    Science.gov (United States)

    Seethala, Srikanth; Hess, Rachel; Bossola, Maurizio; Unruh, Mark L; Weisbord, Steven D

    2010-01-01

    While substantial attention has been paid to the issue of sexual dysfunction in men on chronic dialysis, less is known about this problem in women with end-stage renal disease. We sought to assess sexual dysfunction in women on chronic dialysis and determine whether patients discuss this problem with their providers and receive treatment. We prospectively enrolled women receiving chronic hemodialysis or peritoneal dialysis in Pittsburgh, PA. We asked patients to complete the 19-item Female Sexual Function Index (FSFI) to assess sexual function and a 5-item survey that assessed whether patients had discussed sexual dysfunction with their providers and/or received treatment for this problem in the past. We enrolled 66 patients; 59 (89%) on hemodialysis and 7 (11%) on peritoneal dialysis. All patients completed the FSFI, of whom 53 (80%) had FSFI scores <26.55, consistent with the presence of sexual dysfunction. Of 37 patients who were married or residing with a significant other, 27 (73%) had sexual dysfunction. Among 24 participants who reported having been sexually active over the previous 4 weeks, 11 (46%) had sexual dysfunction. Only 21% of patients with sexual dysfunction had discussed this problem with their gynecologist, renal or primary provider, and 3 (6%) reported having received treatment. Sexual dysfunction is common in women on dialysis, even among patients who are married or residing with a significant other and those who are sexually active. However, few women discuss this issue with their providers or receive treatment.

  10. Dish/stirling hybrid-receiver

    Science.gov (United States)

    Mehos, Mark S.; Anselmo, Kenneth M.; Moreno, James B.; Andraka, Charles E.; Rawlinson, K. Scott; Corey, John; Bohn, Mark S.

    2002-01-01

    A hybrid high-temperature solar receiver is provided which comprises a solar heat-pipe-receiver including a front dome having a solar absorber surface for receiving concentrated solar energy, a heat pipe wick, a rear dome, a sidewall joining the front and the rear dome, and a vapor and a return liquid tube connecting to an engine, and a fossil fuel fired combustion system in radial integration with the sidewall for simultaneous operation with the solar heat pipe receiver, the combustion system comprising an air and fuel pre-mixer, an outer cooling jacket for tangentially introducing and cooling the mixture, a recuperator for preheating the mixture, a burner plenum having an inner and an outer wall, a porous cylindrical metal matrix burner firing radially inward facing a sodium vapor sink, the mixture ignited downstream of the matrix forming combustion products, an exhaust plenum, a fossil-fuel heat-input surface having an outer surface covered with a pin-fin array, the combustion products flowing through the array to give up additional heat to the receiver, and an inner surface covered with an extension of the heat-pipe wick, a pin-fin shroud sealed to the burner and exhaust plenums, an end seal, a flue-gas diversion tube and a flue-gas valve for use at off-design conditions to limit the temperature of the pre-heated air and fuel mixture, preventing pre-ignition.

  11. Chiral Receiving Antenna With Low Backscattering Levels

    CERN Document Server

    Karilainen, Antti O

    2011-01-01

    Receiving antennas absorb power from incident waves, but they also re-radiate some power into surrounding space. If a receiving antenna is to be used as a sensor which should not disturb the object under study, it should scatter as little power as possible in the receiving direction. We propose to use a chiral element composed of two orthogonal chiral particles as a low-scattering sensor.The element can transmit and receive circular polarization in all directions with the Huygens' pattern. We derive the vector effective length for the antenna using the small dipole approximation for the chiral particles. We observe that the element does not backscatter, regardless of the polarization, when the incidence direction is normal to the plane of the particles. Scattered fields, scattered axial ratio, and the scattering cross section are presented. We show that the zero-backscattering property holds also for the antenna element when it is capable to receive all the available power with conjugate loading. The approxim...

  12. Receiver-Controlled Multi-Node Cooperation

    Institute of Scientific and Technical Information of China (English)

    Liang Ye; Yue Li; XueJun Sha; Esko Alasaarela

    2014-01-01

    Since wireless links in Ad hoc networks are more fragile than those in traditional wireless networks due to route flapping, multi-node cooperation plays an important role in ensuring the quality of service ( QoS) . Based on the authors’ previous work, this paper proposes a receiver-controlled multi-node cooperation routing protocol, known as AODV-RCC. In this protocol, nodes form a cooperation group based on signal power. In a cooperation group, signal power between a partner and a transmitter, as well as signal power between the partner and the receiver, must be larger than the signal power between the transmitter and the receiver. Otherwise, the transmission will not benefit from cooperation. To avoid collision or congestion, each cooperation group only contains one partner. This partner offers both data and ACK cooperative retransmission. Its retransmission time should be shorter than the internal retry time of the transmitter’ s MAC layer, because it is better for the partner to retransmit firstly, as it offers a more reliable cooperative link. In AODV-RCC, it is the receiver that chooses the partner, because the link between the partner and the receiver is the most important. According to our simulation results, AODV-RCC shortens the end-to-end delay and increases the packet delivery ratio.

  13. Direct broadcast satellite-radio, receiver development

    Science.gov (United States)

    Vaisnys, A.; Bell, D.; Gevargiz, J.; Golshan, Nasser

    The status of the ongoing Direct Broadcast Satellite-Radio (DBS-R) Receiver Development Task being performed at the Jet Propulsion Laboratory, California Institute of Technology (JPL) is reported. This work is sponsored by the Voice of America/U.S. Information Agency through an agreement with NASA. The objective of this task is to develop, build, test, and demonstrate a prototype receiver that is compatible with reception of digital audio programs broadcast via satellites. The receiver is being designed to operate under a range of reception conditions, including fixed, portable, and mobile, as well as over a sufficiently wide range of bit rates to accommodate broadcasting systems with different cost/audio quality objectives. While the requirements on the receiver are complex, the eventual goal of the design effort is to make the design compatible with low cost production as a consumer product. One solution may be a basic low cost core design suitable for a majority of reception conditions, with optional enhancements for reception in especially difficult environments. Some of the receiver design parameters were established through analysis, laboratory tests, and a prototype satellite experiment accomplished in late 1991. Many of the necessary design trades will be made during the current simulation effort, while a few of the key design options will be incorporated into the prototype for evaluation during the planned satellite field trials.

  14. The ARSQ: the athletes' received support questionnaire.

    Science.gov (United States)

    Freeman, Paul; Coffee, Pete; Moll, Tjerk; Rees, Tim; Sammy, Nadine

    2014-04-01

    To address calls for context-specific measurement of social support, this article reports the development of the Athletes' Received Support Questionnaire (ARSQ) and demonstrates initial evidence for its validity. Across four studies there was support for a four-dimensional structure reflecting emotional, esteem, informational, and tangible received support. There was also support for unidimensional and higher-order models. Further, Study 3 provided some support for convergent validity, with significant correlations between the corresponding dimensions of the ARSQ and the Inventory of Socially Supportive Behaviors. Study 4 provided evidence for the nomological validity of the ARSQ. Emotional and esteem support significantly predicted self-confidence and positive affect, and tangible support significantly moderated the relationship between stress and negative affect. Collectively, these results provide initial evidence for the validity of the ARSQ, and offer researchers flexibility to adopt either a multidimensional or aggregated approach to measuring received support. PMID:24686955

  15. Antennas and Receivers in Radio Interferometry

    CERN Document Server

    Hunter, Todd R

    2016-01-01

    The primary antenna elements and receivers are two of the most important components in a synthesis telescope. Together they are responsible for locking onto an astronomical source in both direction and frequency, capturing its radiation, and converting it into signals suitable for digitization and correlation. The properties and performance of antennas and receivers can affect the quality of the synthesized images in a number of fundamental ways. In this lecture, their most relevant design and performance parameters are reviewed, with emphasis on the current ALMA and VLA systems. We discuss in detail the shape of the primary beam and the components of aperture efficiency, and we present the basics of holography, pointing, and servo control. On receivers, we outline the use of amplifiers and mixers both in the cryogenic front-end and in the room temperature back-end signal path. The essential properties of precision local oscillators (LOs), phase lock loops (PLLs), and LO modulation techniques are also describ...

  16. Randomized transmit and receive ultrasound tomography

    CERN Document Server

    Clement, Gregory T

    2015-01-01

    A tomographic method is considered that forms images from sets of spatially randomized source signals and receiver sensitivities. The method is designed to allow image reconstruction for an extended number of transmitters and receivers in the presence noise and without plane wave approximation or otherwise approximation on the size or regularity of source and receiver functions. An overdetermined set of functions are formed from the Hadamard product between a Gaussian function and a uniformly distributed random number set. It is shown that this particular type of randomization tends to produce well-conditioned matrices whose pseudoinverses may be determined without implementing relaxation methods. When the inverted sets are applied to simulated first-order scattering from a Shepp-Logan phantom, successful image reconstructions are achieved for signal-to-noise ratios (SNR) as low as 1. Evaluation of the randomization approach is conducted by comparing condition numbers with other forms of signal randomization....

  17. Central waste complex interim safety basis

    Energy Technology Data Exchange (ETDEWEB)

    Cain, F.G.

    1995-05-15

    This interim safety basis provides the necessary information to conclude that hazards at the Central Waste Complex are controlled and that current and planned activities at the CWC can be conducted safely. CWC is a multi-facility complex within the Solid Waste Management Complex that receives and stores most of the solid wastes generated and received at the Hanford Site. The solid wastes that will be handled at CWC include both currently stored and newly generated low-level waste, low-level mixed waste, contact-handled transuranic, and contact-handled TRU mixed waste.

  18. Performance Driven Six-Port Receiver and Its Advantages over Low-IF Receiver Architecture

    OpenAIRE

    Abul Hasan; Mohamed Helaoui

    2014-01-01

    This paper provides an extensive analysis of the performance of a six-port based direct conversion receiver (SPR) in terms of signal quality, dynamic range, noise figure, ports matching, isolation, bandwidth, and cost. Calibration technique using multimemory polynomials has been adopted in order to improve the signal quality of the six-port receiver. The performances of the calibrated receiver are then compared with the performances of a commercially available I-Q demodulator used as a low-IF...

  19. Professor Romesh Batra receives Engineering Science Medal

    OpenAIRE

    Nystrom, Lynn A.

    2009-01-01

    Clifton C. Garvin Professor of Engineering Science and Mechanics Romesh C. Batra received the Engineering Science Medal of the Society of Engineering Science (SES) at the recent meeting of the 2009 Joint American Society of Civil Engineers-American Society of Mechanical Engineers-SES Conference on Mechanics and Materials that was held in Blacksburg, Va.

  20. CAS expert receives Tribology Gold Medal

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Prof. XUE Qunji, a senior expert in tribology from the CAS Lanzhou Institute of Chemical Physics (L1CP) and member of the Chinese Academy of Engineering, received the Tribology Gold Medalfor 2011 on February 27, 2012 in Beijing. As one of the world's most outstanding and influential tribologists in the last forty years, Prof.

  1. Reasons Parents Exempt Children from Receiving Immunizations

    Science.gov (United States)

    Luthy, Karlen E.; Beckstrand, Renea L.; Callister, Lynn C.; Cahoon, Spencer

    2012-01-01

    School nurses are on the front lines of educational efforts to promote childhood vaccinations. However, some parents still choose to exempt their children from receiving vaccinations for personal reasons. Studying the beliefs of parents who exempt vaccinations allows health care workers, including school nurses, to better understand parental…

  2. Signal Processing for Improved Wireless Receiver Performance

    DEFF Research Database (Denmark)

    Christensen, Lars P.B.

    2007-01-01

    This thesis is concerned with signal processing for improving the performance of wireless communication receivers for well-established cellular networks such as the GSM/EDGE and WCDMA/HSPA systems. The goal of doing so, is to improve the end-user experience and/or provide a higher system capacity...

  3. Superconducting Submm Integrated Receiver for TELIS

    NARCIS (Netherlands)

    Koshelets, V. P.; Ermakov, A. B.; Filippenko, L. V.; Koryukin, O. V.; Khudchenko, A. V.; Sobolev, A. S.; Torgashin, M. Yu; Yagoubov, P. A.; Hoogeveen, R. W. M.; Vreeling, W. J.; Wild, W.; Pylypenko, O. M.

    2006-01-01

    In this report we present design and first experimental results for development of the submm superconducting integrated receiver spectrometer for Terahertz Limb Sounder (TELIS). TELIS is a collaborative European project to build up a three-channel heterodyne balloon-based spectrometer for measuring

  4. The Communication Between Designer and Design Receiver

    DEFF Research Database (Denmark)

    Dai, Zheng; Dai, Yan

    2009-01-01

    When people think about a product,the first impression always mainly influences the result.Product is the medium of communication between designer and designer receiver.Because both of them have varied different experience and background,the information would be biased during the transferring pro...

  5. Anatomy of a digital coherent receiver

    DEFF Research Database (Denmark)

    Borkowski, Robert; Zibar, Darko; Tafur Monroy, Idelfonso

    2014-01-01

    Digital coherent receivers have gained significant attention in the last decade. The reason for this is that coherent detection, along with digital signal processing (DSP) allows for substantial increase of the channel capacity by employing advanced detection techniques. In this paper, we first r...

  6. Richard W. Ziolkowski Receives Honorary Doctorate

    DEFF Research Database (Denmark)

    Breinbjerg, Olav

    2012-01-01

    At the annual Commemoration of the Technical University of Denmark (DTU) on April 27, 2012, Prof. Richard W. Ziolkowski, University of Arizona (UoA), received DTU's highest academic degree, the Honorary Doctor degree: Doctor Technices Honoris Causa (Figure 1). Prof. Ziolkowski has been a close...

  7. Imatinib induces hypothyroidism in patients receiving levothyroxinc

    NARCIS (Netherlands)

    de Groot, JWB; Zonnenberg, BA; Plukker, JTM; van Der Graaf, WTA; Links, TP

    2005-01-01

    Interactions of imatinib with other drugs have been scarcely reported. We report a previously unknown effect of imatinib on levothyroxine therapy. Eleven patients (1 with gastrointestinal stromal tumor and 10 with medullary thyroid carcinoma) received imatinib. Eight had undergone thyroidectomy and

  8. Quantum communications with an anonymous receiver

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A new protocol for the anonymous communication of quantum information is proposed. The anonymity of the receiver and the privacy of the quantum information are perfectly protected except with exponentially small probability in this protocol. Furthermore, this protocol uses single photons to construct anonymous entanglement instead of multipartite entangled states, and therefore it reduces quantum resources compared with the pioneering work.

  9. Compressed Sensing-Based Direct Conversion Receiver

    DEFF Research Database (Denmark)

    Pierzchlewski, Jacek; Arildsen, Thomas; Larsen, Torben

    2012-01-01

    Due to the continuously increasing computational power of modern data receivers it is possible to move more and more processing from the analog to the digital domain. This paper presents a compressed sensing approach to relaxing the analog filtering requirements prior to the ADCs in a direct...

  10. A 24GHz Radar Receiver in CMOS

    NARCIS (Netherlands)

    Kwok, K.C.

    2015-01-01

    This thesis investigates the system design and circuit implementation of a 24GHz-band short-range radar receiver in CMOS technology. The propagation and penetration properties of EM wave offer the possibility of non-contact based remote sensing and through-the-wall imaging of distance stationary or

  11. Teleseismic receiver functions imaging of Siberia

    DEFF Research Database (Denmark)

    Soliman, Mohammad Youssof Ahmad; Thybo, Hans; Artemieva, Irina

    2014-01-01

    We map the lithosphere in Siberia by using the available broadband seismic data for calculation of Ps- and Sp-wave receiver functions (RF). RFs show converted waves from discontinuities in the vicinity of the seismic stations. The main objective is to image the Moho and upper mantle discontinuities...

  12. Compare benefits before entering receivables financing.

    Science.gov (United States)

    Ferconio, S; Lane, M R

    1991-02-01

    Financing accounts receivables is becoming a popular strategy in the healthcare industry. Factoring and securitization are two financing methods available to hospitals. Patient accounts managers who understand the programs' structures, incentives, and costs will be able to achieve the maximum benefit for their hospitals when choosing one of these transactions. PMID:10109699

  13. An SDR based AIS receiver for satellites

    DEFF Research Database (Denmark)

    Larsen, Jesper Abildgaard; Mortensen, Hans Peter; Nielsen, Jens Frederik Dalsgaard

    2011-01-01

    For a few years now, there has been a high interest in monitoring the global ship traffic from space. A few satellite, capable of listening for ship borne AIS transponders have already been launched, and soon the AAUSAT3, carrying two different types of AIS receivers will also be launched. One...

  14. Howard Feiertag receives hospitality industry award

    OpenAIRE

    Ho, Sookhan

    2004-01-01

    Howard Feiertag, of Blacksburg, an instructor in hospitality and tourism management at Virginia Tech's Pamplin College of Business, received the inaugural Excellence in Sales and Marketing Strategy Award at the Hospitality Sales and Marketing Association/New York University Strategy Conference in New York recently.

  15. Developmental trends in radio receiver design

    Science.gov (United States)

    Chistyakov, N. I.

    1984-03-01

    A historical review of the development of shortwave receiver design is followed by an enumeration of the characteristics of the state of the art in shortwave reception equipment: (1) the problem of band coverage, for example in marine receivers from 10 KHz to 30 MHz, has been resolved by the use of infradyne circuits with an IF of 40 to 80 MHz and a broadband preselector; such designs also make it possible to base the local oscillator on a phase-locked loop; (20 suppression of spurious frequencies is improved by placing them outside the working band through the use of a high first IF; (3) enhanced linearity of the broadband RF amplifier and converter has extended the dynamic range of receivers, and eliminated the need for a narrow band preselector with the use of simple suboctave filters and low pass filters at the input; and (4) the use of a decade frequency synthesizer based on a variable divisor frequency divider, highly stable master crystal oscillators, electronic varactor tuning of the local oscillator and Phase-locked loops provide for precise tuning to the requisite frequency, which is also improved by digital tuning and displays. A major aspect of present design work is the application of microprocessors to automatic tuning, programmed frequency setting and the performance of a variety of diagnostic functions in the receiver.

  16. Global lithospheric imaging using teleseismic receiver functions

    Science.gov (United States)

    Rondenay, S.; Spieker, K.; Halpaap, F.; Farestveit, M.; Sawade, L.; Zijerveld, L.

    2015-12-01

    Project GLImER (Global Lithospheric Imagining using Earthquake Recordings) aims to conduct a global survey of lithospheric interfaces using converted teleseismic body waves. Data from permanent and temporary seismic networks worldwide will be processed automatically to produce global maps of key interfaces (Moho, intra-lithospheric interfaces, lithosphere-asthenosphere boundary). In this presentation, we discuss the challenges associated with automating the analysis of converted waves and the potential of the resulting data products to be used in novel imaging approaches. With regards to automation, we address in particular the search for an optimal deconvolution method in receiver function analysis. To do so, we carry out a systematic comparison of various commonly used deconvolution methods and find that all methods produce equally robust receiver functions provided that a suitable regularization parameter is found. We further note that a suitable regularization can be found objectively for most approaches, thus challenging the belief that only time-domain deconvolution is a viable option for receiver function automation. With regards to imaging applications, we investigate how the resulting global database of receiver functions will be amenable to existing processing approaches as well as new approaches adapted from seismic exploration, including industry-based interpretation tools.

  17. Social effects of migration in receiving countries.

    Science.gov (United States)

    Ohndorf, W

    1989-06-01

    This paper examines the impact of post-1945 migration into Western, Middle, and Northern Europe from Southern Europe, Turkey, and Northern Africa, and migration to the traditional immigration countries by Asian and Latin American immigrants, on the social structures of receiving countries. Between 1955 and 1974, 1) traditional migration to the US and Australia became less important for European countries while traditional receiving countries accepted many immigrants from developing countries; and 2) rapid economic revival in Western and Northern Europe caused a considerable labor shortage which was filled by migrant workers especially from Southern Europe, Turkey, and Northern Africa, who stayed only until they reached their economic goals. Since 1974, job vacancies have declined and unemployment has soared. This employment crisis caused some migrants 1) to return to their countries of origin, 2) to bring the rest of their families to the receiving country, or 3) to lengthen their stay considerably. The number of refugees has also significantly increased since the mid-970s, as has the number of illegal migrants. After the mid-1970s, Europe began to experience integration problems. The different aspects of the impact of migration on social structures include 1) improvement of the housing situation for foreigners, 2) teaching migrants the language of the receiving country, 3) solving the unemployment problem of unskilled migrants, 4) improvement of educational and vocational qualifications of 2nd generation migrants, 5) development of programs to help unemployed wives of migrants to learn the language and meet indigenous women, 6) encouraging migrants to maintain their cultural identity and assisting them with reintegration if they return to their original country, 7) coping with the problems of refugees, and 8) solving the problems of illegal migration. Almost all receiving countries now severely restrict further immigration. [Those policies should result in

  18. Vulcan: A deep-towed CSEM receiver

    Science.gov (United States)

    Constable, Steven; Kannberg, Peter K.; Weitemeyer, Karen

    2016-03-01

    We have developed a three-axis electric field receiver designed to be towed behind a marine electromagnetic transmitter for the purpose of mapping the electrical resistivity in the upper 1000 m of seafloor geology. By careful adjustment of buoyancy and the use of real-time monitoring of depth and altitude, we are able to deep-tow multiple receivers on arrays up to 1200 m long within 50 m of the seafloor, thereby obtaining good coupling to geology. The rigid body of the receiver is designed to reduce noise associated with lateral motion of flexible antennas during towing, and allows the measurement of the vertical electric field component, which modeling shows to be particularly sensitive to near-seafloor resistivity variations. The positions and orientations of the receivers are continuously measured, and realistic estimates of positioning errors can be used to build an error model for the data. During a test in the San Diego Trough, offshore California, inversions of the data were able to fit amplitude and phase of horizontal electric fields at three frequencies on three receivers to about 1% in amplitude and 1° in phase and vertical fields to about 5% in amplitude and 5° in phase. The geological target of the tests was a known cold seep and methane vent in 1000 m water depth, which inversions show to be associated with a 1 km wide resistor at a depth between 50 and 150 m below seafloor. Given the high resistivity (30 Ωm) and position within the gas hydrate stability field, we interpret this to be massive methane hydrate.

  19. A GPS Receiver for Lunar Missions

    Science.gov (United States)

    Bamford, William A.; Heckler, Gregory W.; Holt, Greg N.; Moreau, Michael C.

    2008-01-01

    Beginning with the launch of the Lunar Reconnaissance Orbiter (LRO) in October of 2008, NASA will once again begin its quest to land humans on the Moon. This effort will require the development of new spacecraft which will safely transport people from the Earth to the Moon and back again, as well as robotic probes tagged with science, re-supply, and communication duties. In addition to the next-generation spacecraft currently under construction, including the Orion capsule, NASA is also investigating and developing cutting edge navigation sensors which will allow for autonomous state estimation in low Earth orbit (LEO) and cislunar space. Such instruments could provide an extra layer of redundancy in avionics systems and reduce the reliance on support and on the Deep Space Network (DSN). One such sensor is the weak-signal Global Positioning System (GPS) receiver "Navigator" being developed at NASA's Goddard Space Flight Center (GSFC). At the heart of the Navigator is a Field Programmable Gate Array (FPGA) based acquisition engine. This engine allows for the rapid acquisition/reacquisition of strong GPS signals, enabling the receiver to quickly recover from outages due to blocked satellites or atmospheric entry. Additionally, the acquisition algorithm provides significantly lower sensitivities than a conventional space-based GPS receiver, permitting it to acquire satellites well above the GPS constellation. This paper assesses the performance of the Navigator receiver based upon three of the major flight regimes of a manned lunar mission: Earth ascent, cislunar navigation, and entry. Representative trajectories for each of these segments were provided by NASA. The Navigator receiver was connected to a Spirent GPS signal generator, to allow for the collection of real-time, hardware-in-the-loop results for each phase of the flight. For each of the flight segments, the Navigator was tested on its ability to acquire and track GPS satellites under the dynamical

  20. Central Laboratories Services

    Data.gov (United States)

    Federal Laboratory Consortium — The TVA Central Laboratories Services is a comprehensive technical support center, offering you a complete range of scientific, engineering, and technical services....

  1. Time perception mechanisms at central nervous system

    OpenAIRE

    Rhailana Fontes; Jéssica Ribeiro; Gupta, Daya S.; Dionis Machado; Fernando Lopes-Júnior; Francisco Magalhães; Victor Hugo Bastos; Kaline Rocha; Victor Marinho; Gildário Lima; Bruna Velasques; Pedro Ribeiro; Marco Orsini; Bruno Pessoa; Marco Antonio Araujo Leite

    2016-01-01

    The five senses have specific ways to receive environmental information and lead to central nervous system. The perception of time is the sum of stimuli associated with cognitive processes and environmental changes. Thus, the perception of time requires a complex neural mechanism and may be changed by emotional state, level of attention, memory and diseases. Despite this knowledge, the neural mechanisms of time perception are not yet fully understood. The objective is to relate the mechanisms...

  2. CFD analysis of supercritical CO2 used as HTF in a solar tower receiver

    Science.gov (United States)

    Roldán, M. I.; Fernández-Reche, J.

    2016-05-01

    The relative cost of a solar receiver can be minimized by the selection of an appropriate heat transfer fluid capable of achieving high receiver efficiencies. In a conventional central receiver system, the concentrated solar energy is transferred from the receiver tube walls to the heat transfer fluid (HTF), which passes through a heat exchanger to generate steam for a Rankine cycle. Thus, higher working fluid temperature is associated with greater efficiency in receiver and power cycle. Emerging receiver designs that can enable higher efficiencies using advanced power cycles, such as supercritical CO2 (s-CO2) closed-loop Brayton cycles, include direct heating of s-CO2 in tubular receiver designs capable of withstanding high internal fluid pressures (around 20 MPa) and temperatures (900 K). Due to the high pressures required and the presence of moving components installed in pipelines (ball-joints and/or flexible connections), the use of s-CO2 presents many technical challenges due to the compatibility of seal materials and fluid leakages of the moving connections. These problems are solved in solar tower systems because the receiver is fixed. In this regard, a preliminary analysis of a tubular receiver with s-CO2 as HTF has been developed using the design of a molten-salt receiver which was previously tested at Plataforma Solar de Almería (PSA). Therefore, a simplified CFD model has been carried out in this study in order to analyze the feasibility of s-CO2 as HTF in solar towers. Simulation results showed that the heat gained by s-CO2 was around 75% greater than the one captured by molten salts (fluid inlet temperature of 715 K), but at a pressure range of 7.5-9.7 MPa. Thus, the use of s-CO2 as HTF in solar tower receivers appears to be a promising alternative, taking into account both the operating conditions required and their maintenance cost.

  3. Perception of older adults receiving palliative care

    Directory of Open Access Journals (Sweden)

    Fernanda Laporti Seredynskyj

    2014-06-01

    Full Text Available The present study aimed at understanding the perception of older adults who are receiving palliative oncological care on self care in relation to different stages of the disease and how such perception affected their lives. This is a qualitative study using oral history conducted with 15 older adults receiving palliative chemotherapy treatment in a health institution. The following categories emerged: social network, perspectives for confronting life, changes and spirituality. It is necessary for nursing staff to understand this process so that the measures implemented take into account all of the implications of the disease and aim at improving quality of life.   doi: 10.5216/ree.v16i2.22795.

  4. Fused silica windows for solar receiver applications

    Science.gov (United States)

    Hertel, Johannes; Uhlig, Ralf; Söhn, Matthias; Schenk, Christian; Helsch, Gundula; Bornhöft, Hansjörg

    2016-05-01

    A comprehensive study of optical and mechanical properties of quartz glass (fused silica) with regard to application in high temperature solar receivers is presented. The dependence of rupture strength on different surface conditions as well as high temperature is analyzed, focussing particularly on damage by devitrification and sandblasting. The influence of typical types of contamination in combination with thermal cycling on the optical properties of fused silica is determined. Cleaning methods are compared regarding effectiveness on contamination-induced degradation for samples with and without antireflective coating. The FEM-aided design of different types of receiver windows and their support structure is presented. A large-scale production process has been developed for producing fused silica dome shaped windows (pressurized window) up to a diameter of 816 mm. Prototypes were successfully pressure-tested in a test bench and certified according to the European Pressure Vessel Directive.

  5. North Dakota geology school receives major gift

    Science.gov (United States)

    Showstack, Randy

    2012-10-01

    Petroleum geology and related areas of study at the University of North Dakota (UND) received a huge financial boost with the announcement on 24 September of $14 million in private and public partnership funding. The university announced the naming of the Harold Hamm School of Geology and Geological Engineering, formerly a department within the College of Engineering and Mines, in recognition of $10 million provided as a gift by oilman Harold Hamm and Continental Resources, Inc. Hamm is the chair and chief executive officer of Continental, the largest leaseholder in the Bakken Play oil formation in North Dakota and Montana, and he is also an energy policy advisor to Republican presidential candidate Mitt Romney. UND also received $4 million from the Oil and Gas Research Program of the North Dakota Industrial Commission to support geology and geological engineering education and research.

  6. CERN Press Office receives award from Euroscience

    CERN Multimedia

    2009-01-01

    The CERN Communication group has received an award for its efforts in communicating the LHC first beam to the media and the public. James Gillies, head of the Communication group was presented the AlphaGalileo Research Public Relations Award on Wednesday, 14 October during the Euroscience Media Award Ceremony in Hannover. "It’s great to receive this recognition," said Gillies. "Of course, we had great material to work with: the LHC is a fantastic story and one that is going to get even better. Angels, Demons and black holes also had their roles to play, but behind the media interest there’s been a lot of hard work by my team. This is for them." The CERN Communication group also works with communication professionals in all the CERN Member States and major physics labs around the world through the European Particle Physics Communication Network, and the InterAction collaboration. "Without them," says Gillies, &am...

  7. Screen-printed flexible MRI receive coils

    Science.gov (United States)

    Corea, Joseph R.; Flynn, Anita M.; Lechêne, Balthazar; Scott, Greig; Reed, Galen D.; Shin, Peter J.; Lustig, Michael; Arias, Ana C.

    2016-03-01

    Magnetic resonance imaging is an inherently signal-to-noise-starved technique that limits the spatial resolution, diagnostic image quality and results in typically long acquisition times that are prone to motion artefacts. This limitation is exacerbated when receive coils have poor fit due to lack of flexibility or need for padding for patient comfort. Here, we report a new approach that uses printing for fabricating receive coils. Our approach enables highly flexible, extremely lightweight conforming devices. We show that these devices exhibit similar to higher signal-to-noise ratio than conventional ones, in clinical scenarios when coils could be displaced more than 18 mm away from the body. In addition, we provide detailed material properties and components performance analysis. Prototype arrays are incorporated within infant blankets for in vivo studies. This work presents the first fully functional, printed coils for 1.5- and 3-T clinical scanners.

  8. Graphene radio frequency receiver integrated circuit.

    Science.gov (United States)

    Han, Shu-Jen; Garcia, Alberto Valdes; Oida, Satoshi; Jenkins, Keith A; Haensch, Wilfried

    2014-01-01

    Graphene has attracted much interest as a future channel material in radio frequency electronics because of its superior electrical properties. Fabrication of a graphene integrated circuit without significantly degrading transistor performance has proven to be challenging, posing one of the major bottlenecks to compete with existing technologies. Here we present a fabrication method fully preserving graphene transistor quality, demonstrated with the implementation of a high-performance three-stage graphene integrated circuit. The circuit operates as a radio frequency receiver performing signal amplification, filtering and downconversion mixing. All circuit components are integrated into 0.6 mm(2) area and fabricated on 200 mm silicon wafers, showing the unprecedented graphene circuit complexity and silicon complementary metal-oxide-semiconductor process compatibility. The demonstrated circuit performance allow us to use graphene integrated circuit to perform practical wireless communication functions, receiving and restoring digital text transmitted on a 4.3-GHz carrier signal.

  9. Reducing the convective losses of cavity receivers

    Science.gov (United States)

    Flesch, Robert; Grobbel, Johannes; Stadler, Hannes; Uhlig, Ralf; Hoffschmidt, Bernhard

    2016-05-01

    Convective losses reduce the efficiency of cavity receivers used in solar power towers especially under windy conditions. Therefore, measures should be taken to reduce these losses. In this paper two different measures are analyzed: an air curtain and a partial window which covers one third of the aperture opening. The cavity without modifications and the usage of a partial window were analyzed in a cryogenic wind tunnel at -173°C. The cryogenic environment allows transforming the results from the small model cavity to a large scale receiver with Gr≈3.9.1010. The cavity with the two modifications in the wind tunnel environment was analyzed with a CFD model as well. By comparing the numerical and experimental results the model was validated. Both modifications are capable of reducing the convection losses. In the best case a reduction of about 50 % was achieved.

  10. Central centrifugal cicatricial alopecia

    OpenAIRE

    Collin Blattner; Dennis C Polley; Frank Ferritto; Elston, Dirk M

    2013-01-01

    Central centrifugal cicatricial alopecia is a common cause of progressive permanent apical alopecia. This unique form of alopecia includes entities previously know as “hot comb alopecia,” “follicular degeneration syndrome,” “pseudopelade” in African Americans and “central elliptical pseudopelade” in Caucasians. The etiology appears to be multifactorial and the condition occurs in all races.

  11. Optimal Central Bank Transparency

    NARCIS (Netherlands)

    van der Cruijsen, C.A.B.; Eijffinger, S.C.W.; Hoogduin, L.H.

    2008-01-01

    Should central banks increase their degree of transparency any further? We show that there is likely to be an optimal intermediate degree of central bank transparency. Up to this optimum more transparency is desirable: it improves the quality of private sector inflation forecasts. But beyond the opt

  12. Optimal central bank transparency

    NARCIS (Netherlands)

    C.A.B. van der Cruijsen; S.C.W. Eijffinger; L. Hoogduin

    2008-01-01

    Should central banks increase their degree of transparency any further? We show that there is likely to be an optimal intermediate degree of central bank transparency. Up to this optimum more transparency is desirable: it improves the quality of private sector inflation forecasts. But beyond the opt

  13. Optimal central bank transparency

    NARCIS (Netherlands)

    C.A.B. van der Cruijsen; S.C.W. Eijffinger; L.H. Hoogduin

    2010-01-01

    Should central banks increase their degree of transparency any further? We show that there is likely to be an optimal intermediate degree of central bank transparency. Up to this optimum more transparency is desirable: it improves the quality of private sector inflation forecasts. But beyond the opt

  14. Central pontine myelinolysis

    Science.gov (United States)

    ... from one nerve to another. The most common cause of central pontine myelinolysis is a quick change in the body's sodium ... The nerve damage caused by central pontine myelinolysis is usually ... The disorder can cause serious long-term (chronic) disability.

  15. Solar receiver performance of point focusing collector system

    Science.gov (United States)

    Wu, Y. C.; Wen, L. C.

    1978-01-01

    The solar receiver performance of cavity receivers and external receivers used in dispersed solar power systems was evaluated for the temperature range 300-1300 C. Several parameters of receiver and concentrator are examined. It was found that cavity receivers are generally more efficient than external receivers, especially at high temperatures which require a large heat transfer area. The effects of variation in the ratio of receiver area to aperture area are considered.

  16. Digital Signal Processor For GPS Receivers

    Science.gov (United States)

    Thomas, J. B.; Meehan, T. K.; Srinivasan, J. M.

    1989-01-01

    Three innovative components combined to produce all-digital signal processor with superior characteristics: outstanding accuracy, high-dynamics tracking, versatile integration times, lower loss-of-lock signal strengths, and infrequent cycle slips. Three components are digital chip advancer, digital carrier downconverter and code correlator, and digital tracking processor. All-digital signal processor intended for use in receivers of Global Positioning System (GPS) for geodesy, geodynamics, high-dynamics tracking, and ionospheric calibration.

  17. Counterrotator And Correlator For GPS Receivers

    Science.gov (United States)

    Thomas, J. Brooks; Srinivasan, Jeffrey M.; Meehan, Thomas K.

    1989-01-01

    Accurate, all-digital, high-speed processor comprising correlator and down-converter developed for receivers in Global Positioning System (GPS). Processor reduces roundoff and commensurability errors to extremely small values. Use of digital chip and phase advancers provides outstanding control and accuracy in phase and feedback. Great flexibility imparted by provision for arbitrary starting time and integration length. Minimum-bit design requires minimum number of logical elements, thereby reducing size, power, and cost.

  18. Defense TRU waste transportation and receiving simulation

    International Nuclear Information System (INIS)

    Pacific Northwest Laboratory has recently conducted a simulation analysis to predict the transportation and waste handling equipment requirements for transporting government-owned transuranic waste to the Waste Isolation Pilot Plant (WIPP). Two interrelated models were developed. One estimates the time required to receive and unload shipping containers at the WIPP. The other model uses this estimate to predict the number of shipping containers and transporters that will be required

  19. TRA - Transmit Receive Array (project plan)

    OpenAIRE

    Zabel, F; Martins, C.; Jesus, S.M.; Silva, A

    2006-01-01

    SiPLAB Report 05/06, FCT, University of Algarve,2006. This report describes a project plan for the development of a Transmit Receive Array (TRA). This system is under development for the Underwater Acoustic Barriers (UAB) project which aims at studying, developing and testing in the field the concept of building an underwater acoustic barrier for detecting intruders in a given area. FCT

  20. Central Diffraction at ALICE

    CERN Document Server

    Lämsä, Jerry W

    2011-01-01

    The ALICE experiment is shown to be well suited for studies of exclusive final states from central diffractive reactions. The gluon-rich environment of the central system allows detailed QCD studies and searches for exotic meson states, such as glueballs, hybrids and new charmonium-like states. It would also provide a good testing ground for detailed studies of heavy quarkonia. Due to its central barrel performance, ALICE can accurately measure the low-mass central systems with good purity. The efficiency of the Forward Multiplicity Detector (FMD) and the Forward Shower Counter (FSC) system for detecting rapidity gaps is shown to be adequate for the proposed studies. With this detector arrangement, valuable new data can be obtained by tagging central diffractive processes.

  1. Central diffraction at ALICE

    Energy Technology Data Exchange (ETDEWEB)

    Laemsae, J W; Orava, R, E-mail: risto.orava@helsinki.fi [Helsinki Insitute of Physics, and Division of Elementary Particle Physics, Department of Physics, PL 64 (Gustaf Haellstroeminkatu 2a), FI-00014 University of Helsinki (Finland)

    2011-02-01

    The ALICE experiment is shown to be well suited for studies of exclusive final states from central diffractive reactions. The gluon-rich environment of the central system allows detailed QCD studies and searches for exotic meson states, such as glueballs, hybrids and new charmonium-like states. It would also provide a good testing ground for detailed studies of heavy quarkonia. Due to its central barrel performance, ALICE can accurately measure the low-mass central systems with good purity. The efficiency of the Forward Multiplicity Detector (FMD) and the Forward Shower Counter (FSC) system for detecting rapidity gaps is shown to be adequate for the proposed studies. With this detector arrangement, valuable new data can be obtained by tagging central diffractive processes.

  2. Organizational centralization in radiology.

    Science.gov (United States)

    Aas, I H Monrad

    2006-01-01

    Traditionally, hospitals have a radiology department, where images are taken and interpretation occurs. Teleradiology makes it possible to capture images in one location and transmit them elsewhere for interpretation. Organizational centralization of radiology interpretations is therefore of interest. Empirical data have been collected in qualitative interviews of 26 resource persons with substantial experience with picture archiving and communication systems and teleradiology, from 12 departments of radiology in Norway. The response rate was 90%. A total of 21 theoretically possible types of centralization of image interpretation were identified, representing combinations of three categories of geographical centralization, and seven categories of centralization according to function. Various advantages and disadvantages of centralization were identified. Organizational changes may be decisive for the future of teleradiology, but it may be wise to plan for change in small steps, since we know little about how broad future organizational changes based on teleradiology will be, or what will decide how far particular organizations will go. PMID:16438776

  3. Development of Receiver Stimulator for Auditory Prosthesis

    Directory of Open Access Journals (Sweden)

    K. Raja Kumar

    2010-05-01

    Full Text Available The Auditory Prosthesis (AP is an electronic device that can provide hearing sensations to people who are profoundly deaf by stimulating the auditory nerve via an array of electrodes with an electric current allowing them to understand the speech. The AP system consists of two hardware functional units such as Body Worn Speech Processor (BWSP and Receiver Stimulator. The prototype model of Receiver Stimulator for Auditory Prosthesis (RSAP consists of Speech Data Decoder, DAC, ADC, constant current generator, electrode selection logic, switch matrix and simulated electrode resistance array. The laboratory model of speech processor is designed to implement the Continuous Interleaved Sampling (CIS speech processing algorithm which generates the information required for electrode stimulation based on the speech / audio data. Speech Data Decoder receives the encoded speech data via an inductive RF transcutaneous link from speech processor. Twelve channels of auditory Prosthesis with selectable eight electrodes for stimulation of simulated electrode resistance array are used for testing. The RSAP is validated by using the test data generated by the laboratory prototype of speech processor. The experimental results are obtained from specific speech/sound tests using a high-speed data acquisition system and found satisfactory.

  4. Russian institute receives CMS Gold Award

    CERN Multimedia

    Patrice Loïez

    2003-01-01

    The Snezhinsk All-Russian Institute of Scientific Research for Technical Physics (VNIITF) of the Russian Federal Nuclear Centre (RFNC) is one of twelve CMS suppliers to receive awards for outstanding performance this year. The CMS Collaboration took the opportunity of the visit to CERN of the Director of VNIITF and his deputy to present the CMS Gold Award, which the institute has received for its exceptional performance in the assembly of steel plates for the CMS forward hadronic calorimeter. This calorimeter consists of two sets of 18 wedge-shaped modules arranged concentrically around the beam-pipe at each end of the CMS detector. Each module consists of steel absorber plates with quartz fibres inserted into them. The institute developed a special welding technique to assemble the absorber plates, enabling a high-quality detector to be produced at relatively low cost.RFNC-VNIITF Director Professor Georgy Rykovanov (right), is seen here receiving the Gold Award from Felicitas Pauss, Vice-Chairman of the CMS ...

  5. Terahertz Superconducting Hot Electron Bolometer Heterodyne Receivers

    Science.gov (United States)

    Gao, J. R.; Hajenius, M..; Yang, Z. Q.; Baselmans, J. J. A.; Khosropanah, P..; Barends, R..; Klapwijk, T. M.

    2007-06-01

    We highlight the progress on NbN hot electron bolometer (HEB) mixers achieved through fruitful collaboration between SRON Netherlands Institute for Space Research and Delft University of Technology, the Netherlands. This includes the best receiver noise temperatures of 700 K at 1.63 THz using a twin-slot antenna mixer and 1050 K at 2.84 THz using a spiral antenna coupled HEB mixer. The mixers are based on thin NbN films on Si and fabricated with a new contact-process and-structure. By reducing their areas HEB mixers have shown an LO power requirement as low as 30 nW. Those small HEB mixers have demonstrated equivalent sensitivity as those with large areas provided the direct detection effect due to broadband radiation is removed. To manifest that a HEB based heterodyne receiver can in practice be used at arbitrary frequencies above 2 THz, we demonstrate a 2.8 THz receiver using a THz quantum cascade laser (QCL) as local oscillator.

  6. Radio Astronomy Software Defined Receiver Project

    Energy Technology Data Exchange (ETDEWEB)

    Vacaliuc, Bogdan [ORNL; Leech, Marcus [Shirleys Bay Radio Astronomy Consortium; Oxley, Paul [Retired; Flagg, Richard [Retired; Fields, David [ORNL

    2011-01-01

    The paper describes a Radio Astronomy Software Defined Receiver (RASDR) that is currently under development. RASDR is targeted for use by amateurs and small institutions where cost is a primary consideration. The receiver will operate from HF thru 2.8 GHz. Front-end components such as preamps, block down-converters and pre-select bandpass filters are outside the scope of this development and will be provided by the user. The receiver includes RF amplifiers and attenuators, synthesized LOs, quadrature down converters, dual 8 bit ADCs and a Signal Processor that provides firmware processing of the digital bit stream. RASDR will interface to a user s PC via a USB or higher speed Ethernet LAN connection. The PC will run software that provides processing of the bit stream, a graphical user interface, as well as data analysis and storage. Software should support MAC OS, Windows and Linux platforms and will focus on such radio astronomy applications as total power measurements, pulsar detection, and spectral line studies.

  7. Performance Driven Six-Port Receiver and Its Advantages over Low-IF Receiver Architecture

    Directory of Open Access Journals (Sweden)

    Abul Hasan

    2014-01-01

    Full Text Available This paper provides an extensive analysis of the performance of a six-port based direct conversion receiver (SPR in terms of signal quality, dynamic range, noise figure, ports matching, isolation, bandwidth, and cost. Calibration technique using multimemory polynomials has been adopted in order to improve the signal quality of the six-port receiver. The performances of the calibrated receiver are then compared with the performances of a commercially available I-Q demodulator used as a low-IF receiver. The main advantages and disadvantages of the SPR compared to the low-IF receiver are highlighted. The major advantages of the SPR come in terms of its available input frequency bandwidth and the low power requirement. The SPR system requires no external bias supply but suffers in terms of the available conversion gain. A better port matching of the SPR can be guaranteed over a wide frequency bandwidth, which mixer based receiver systems lack. The main component limiting the performance of a SPR is the diode detector. A faster and a better diode detector will alleviate some of the problems highlighted in this paper. The SPR system is calibratable and its error-vector-magnitude performance can be made better than the I-Q demodulator used as a low-IF receiver.

  8. Imaging central pain syndromes.

    Science.gov (United States)

    Veldhuijzen, Dieuwke S; Greenspan, Joel D; Kim, Jong H; Coghill, Robert C; Treede, Rolf-Detlef; Ohara, Shinji; Lenz, Frederick A

    2007-06-01

    Anatomic, functional, and neurochemical imaging studies have provided new investigative tools in the study of central pain. High-resolution imaging studies allow for precise determination of lesion location, whereas functional neuroimaging studies measure pathophysiologic consequences of injury to the central nervous system. Additionally, magnetic resonance spectroscopy evaluates lesion-induced neurochemical changes in specific brain regions that may be related to central pain. The small number of studies to date precludes definitive conclusions, but the recent findings provide information that either supports or refutes current hypotheses and can serve to generate new ideas.

  9. Thatcher Receives 2004 Charles A. Whitten Medal

    Science.gov (United States)

    Stein, Ross

    2005-02-01

    Wayne Thatcher received the Whitten Medal at the 2004 Fall Meeting Honors Ceremony on 15 December, in San Francisco, California. The medal is given for outstanding achievement in research on the form and dynamics of the Earth and planets. Citation. Armed with geodesy, Wayne Thatcher has probed the behavior of great earthquakes, concentrating on the two sites where large events are frequent and the geodetic record is lush: the western United States and Japan. From this, he has garnered deep insights into the earthquake cycle-the pattern of strain accumulation and release of which an earthquake is only the most visible part.

  10. Optoelectronic Receiver For Communication And Control

    Science.gov (United States)

    Kunath, Richard; Bendett, Mark; Mactaggart, I. Ross

    1994-01-01

    Many operational and diagnostic features integrated into circuit chip. GaAs-based integrated circuit designed to serve as optoelectronic interface in phased-array antenna. Intended function to receive digital control signals transmitted on optical fiber and to convert signals to electronic control signals, which then applied to monolithic microwave integrated circuit (MMIC). Also used in reception of high-rate optical digital communications within computers, between computers, and in signal-distribution systems in aircraft, automobiles, and ships. Interface circuit represents significant improvement over preexisting interface circuits in that its clock-signal-recovery subcircuit requires little or no preamble for immediate synchronization.

  11. MSW devices for EW receiver applications

    Science.gov (United States)

    Adam, J. D.

    A compressive electronic warfare receiver has been constructed using a magnetostatic wave (MSW) dispersive delay line and filter bank. Attention is presently given to the performance characteristics and potentialities of these devices with respect to dynamic range, probability of signal detection, and digital processing. Phase error and amplitude response improvements are noted to be required in order to achieve the full potential of this approach; in particular, the video outputs from a 1-GHz bandwidth delay line cannot be adequately processed by means of current electronic techniques.

  12. Radiation Doses Received by the Irish Population

    International Nuclear Information System (INIS)

    Some chemical elements present in the environment since the Earth was formed are naturally radioactive and exposure to these sources of radiation cannot be avoided. There have also been additions to this natural inventory from artificial sources of radiation that did not exist before the 1940s. Other sources of radiation exposure include cosmic radiation from outer space and the use of radiation in medical diagnosis and treatment. There can be large variability in the dose received by invividual members of the population from any given source. Some sources of radiation expose every member of the population while, in other cases, only selected individuals may be exposed. For example, natural radioactivity is found in all soils and therefore everybody receives some radiation dose from this activity. On the other hand, in the case of medical exposures, only those who undergo a medical procedure using radiation will receive a radiation dose. The Radiological Protection Institute of Ireland (RPII) has undertaken a comprehensive review of the relevant data on radiation exposure in Ireland. Where no national data have been identified, the RPII has either undertaken its own research or has referred to the international literature to provide a best estimate of what the exposure in Ireland might be. This has allowed the relative contribution of each source to be quantified. This new evaluation is the most up-to-date assessment of radiation exposure and updates the assessment previously reported in 2004. The dose quoted for each source is the annual 'per caput' dose calculated on the basis of the most recently available data. This is an average value calculated by adding the doses received by each individual exposed to a given radiation source and dividing the total by the current population of 4.24 million. All figures have been rounded, consistent with the accuracy of the data. In line with accepted international practice, where exposure takes place both indoors and

  13. Full-wave receiver architecture for the homodyne motion sensor

    Energy Technology Data Exchange (ETDEWEB)

    Haugen, Peter C.; Dallum, Gregory E.; Welsh, Patrick A.; Romero, Carlos E.

    2015-09-29

    A homodyne motion sensor or detector based on ultra-wideband radar utilizes the entire received waveform through implementation of a voltage boosting receiver. The receiver includes a receiver input and a receiver output. A first diode is connected to the receiver output. A first charge storage capacitor is connected from between the first diode and the receiver output to ground. A second charge storage capacitor is connected between the receiver input and the first diode. A second diode is connected from between the second charge storage capacitor and the first diode to ground. The dual diode receiver performs voltage boosting of a RF signal received at the receiver input, thereby enhancing receiver sensitivity.

  14. Central nervous system

    Science.gov (United States)

    The central nervous system is composed of the brain and spinal cord. Your brain and spinal cord serve as the main "processing center" for your entire nervous system. They control all the workings of your body.

  15. Central Station Design Options

    DEFF Research Database (Denmark)

    2011-01-01

    The purpose of EDISON Work Package 4.1 is the evaluation of possible Central (charging) Stations design options for making possible the public charging of Electric Vehicles (EVs). A number of scenarios for EVs are assessed, with special emphasis on the options of Fast Charging and Battery Swapping....... The work identifies the architecture, sizing and siting of prospective Central Stations in Denmark, which can be located at shopping centers, large car parking lots or gas stations. Central Stations are planned to be integrated in the Danish distribution grid. The Danish island of Bornholm, where a high.......g. due to vandalism, the charge supply circuit is disconnected. More electrical vehicles on the market are capable today of quick charging up to 50 kW power level. The feasibility of Central Stations with fast charging/swapping option, their capacity, design, costs and grid impact, as well as battery...

  16. Central Data Exchange

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Central Data Exchange (CDX) enables fast, efficient and more accurate environmental data submissions from state and local governments, industry and tribes to...

  17. "Central Station" Londonis

    Index Scriptorium Estoniae

    2000-01-01

    Londoni galeriis Milch seitsme läti, leedu ja eesti kunstniku projekt "Central Station". Kuraatorid Lisa Panting, Sally Tallant. Eestist osalevad Hanno Soans (Catarina Campinoga koostöös valminud video), Kiwa, Kai Kaljo

  18. Central Asian Republic Info

    Data.gov (United States)

    US Agency for International Development — CAR Info is designed and managed by the Central Asian Republic Mission to fill in the knowledge and reporting gaps in existing agency systems for that Mission. It...

  19. Central nervous system resuscitation

    DEFF Research Database (Denmark)

    McIntosh, T K; Garde, E; Saatman, K E;

    1997-01-01

    Traumatic injury to the central nervous system induces delayed neuronal death, which may be mediated by acute and chronic neurochemical changes. Experimental identification of these injury mechanisms and elucidation of the neurochemical cascade following trauma may provide enhanced opportunities...

  20. Response to state comments on the revised draft North Central Regional characterization reports for the Crystalline Repository Project

    International Nuclear Information System (INIS)

    The purpose of this document is to respond to the comments received from the states of the North Central Region on the revised draft North Central Regional Characterization Reports (RCRs). The responses in this document indicate the manner in which the suggestions or comments received have been considered in modifying the revised draft North Central RCRs. Both general comments related to the overall Crystalline Repository Project (CRP) and comments on specific sections of the RCRs are addressed. This document responds to North Central State comments on both the revised draft North Central Regional Geologic Characterization Report (RGCR) and the revised draft North Central Regional Environmental Characterization Report (RECR)

  1. Woese on the received view of evolution.

    Science.gov (United States)

    Sarkar, Sahotra

    2014-01-01

    As part of his attempt to reconstruct the earliest phase of the evolution of life on Earth, Woese produced a compelling critique of the received view of evolution from the 20th century. This paper explicitly articulates two related features of that critique that are fundamental but the first of which has not been sufficiently clearly recognized in the context of evolutionary theorizing: (1) according to Woese's scenario of communal evolution during life's earliest phase (roughly, the first billion years of life on Earth), well-defined biological individuals (and, thus, individual lineages) did not exist; and (2) during that phase, evolutionary change took place through ubiquitous horizontal gene transfer (HGT) rather than through vertical transmission of features (including genes) and the combinatorics of HGT was the dominant mechanism of evolutionary change. Both factors present serious challenges to the received view of evolution and that framework would have to be radically altered to incorporate these factors. The extent to which this will be necessary will depend on whether Woese's scenario of collective early evolution is correct.

  2. The Submillimeter Array Antennas and Receivers

    CERN Document Server

    Blundell, R

    2005-01-01

    The Submillimeter Array (SMA) was conceived at the Smithsonian Astrophysical Observatory in 1984 as a six element interferometer to operate in the major atmospheric windows from about 200 to 900 GHz. In 1996, the Academica Sinica Institute of Astronomy and Astrophysics of Taiwan joined the project and agreed to provide additional hardware to expand the interferometer to eight elements. All eight antennas are now operating at the observatory site on Mauna Kea, and astronomical observations have been made in the 230, 345, and 650 GHz bands. The SMA antennas have a diameter of 6 m, a surface accuracy of better than 25 micron rms, and can be reconfigured to provide spatial resolutions down to about 0.5" at 200 GHz and, eventually, 0.1" at 850 GHz. Coupling to the receiver package within each antenna is achieved via a beam waveguide, in a bent Nasmyth configuration, comprised of a flat tertiary mirror and two ellipsoidal mirrors that form a secondary pupil used for receiver calibration. An additional fixed mirror ...

  3. Steam Rankine Solar Receiver, phase 2

    Science.gov (United States)

    Deanda, L. E.; Faust, M.

    1981-01-01

    A steam rankine solar receiver (SRSR) based on a tubular concept was designed and developed. The SRSR is an insulated, cylindrical coiled tube boiler which is mounted at the focal plane of a fully tracking parabolic solar reflector. The concentrated solar energy received at the focal plane is then transformed to thermal energy through steam generation. The steam is used in a small Rankine cycle heat engine to drive a generator for the production of electrical energy. The SRSR was designed to have a dual mode capability, performing as a once through boiler with and without reheat. This was achieved by means of two coils which constitute the boiler. The boiler core size of the SRSR is 17.0 inches in diameter and 21.5 inches long. The tube size is 7/16 inch I.D. by 0.070 inch wall for the primary, and 3/4 inch I.D. by 0.125 inch wall for the reheat section. The materials used were corrosion resistant steel (CRES) type 321 and type 347 stainless steel. The core is insulated with 6 inches of cerablanket insulation wrapped around the outer wall. The aperture end and the reflector back plate at the closed end section are made of silicon carbide. The SRSR accepts 85 kwth and has a design life of 10,000 hrs when producing steam at 1400 F and 2550 psig.

  4. Transactions Security Tools in Account Receivables Management

    Directory of Open Access Journals (Sweden)

    Anna Wodyńska

    2008-01-01

    Full Text Available Large competition among goods and services suppliers caused that granting clients deferred term of payment became a standard, so in other word granting clients commercial credit is a standard. Companies try to limit credit risk by securing their trade transactions in accordance with their credit policy that determines in some way the choice of trade transaction security tools.This article presents a full range of trade transaction security tools according to the general division into personal and property securities. The author pays attention to the fact that while conducting a proper credit policy in relation to clients, a company has chances to monitor efficiently the receivables and insist on their payment as well as use, as needed, the earlier prepared trade transaction security tools.The author convinces that regardless of the choice of trade transaction security tools, or reasons leading the receivables managing person, the basic criterion of security evaluation shall be its real, checked and verified value. The pledge on an object that does not exist is not worth much. The same applies to security granted by an insolvent person.

  5. Centralization and political accountability

    OpenAIRE

    Hindriks, Jean; Lockwood, Ben

    2004-01-01

    In this paper we abstract from the usual gains and costs of decentralization (e.g. preference matching, spillovers and economies of scale). Instead we compare the political accountability of decentralized governments relative to centralized ones when there is a risk of "bad" governance. We study both the selection and incentive effects of accountability. A key aspect of centralization is to make the politician answerable to multiple constituencies subject to a common budget constraint. Our ma...

  6. Central Bank independence

    OpenAIRE

    Vasile DEDU; Tiberiu STOICA

    2012-01-01

    In this paper we present the key aspects regarding central bank’s independence. Most economists consider that the factor which positively influences the efficiency of monetary policy measures is the high independence of the central bank. We determined that the National Bank of Romania (NBR) has a high degree of independence. NBR has both goal and instrument independence. We also consider that the hike of NBR’s independence played an important role in the significant disin...

  7. Outsourcing central banking

    DEFF Research Database (Denmark)

    Khoury, Sarkis Joseph; Wihlborg, Clas

    2005-01-01

    The literature on Currency Boards (CB) stops at the water edge in terms of dealing with the totality of the functions of a central bank. Monetary policy, and banking supervisioncan be "outsourced" in an open economy with substantial foreign direct investment (FDI)in the banking sector if political...... the feasibility of, and constraints on, outsourcing of central bank functions. A brief discussion of the Argentinian experience is used for contrast.Key words: Currency Board, Foreign Banks, Supervision, Regional Integration,outsourcing....

  8. Community Supported Agriculture is thriving in the Central Valley

    OpenAIRE

    Galt, Ryan E; O'Sullivan, Libby; Beckett, Jessica; Hiner, Colleen C

    2012-01-01

    Community Supported Agriculture operations (CSAs) have grown rapidly in recent years. The original model, in which members support a farming operation by paying for produce in advance and receive a share of the farm's produce in return, has been adapted, with much innovation. Since little research existed on CSAs in the Central Valley, we surveyed and carried out in-depth interviews with 54 CSA farmers and two CSA organizers in the Central Valley and surrounding foothills. Here we focus on fo...

  9. Three Specialized Innovations for FAST Wideband Receiver

    Science.gov (United States)

    Zhang, Xia; Yu, Xinying; Duan, Ran; Hao, Jie; Li, Di

    2015-08-01

    The National Astronomical Observatories of the Chinese Academy of Sciences (NAOC) will soon finish the largest antenna in the world. Known as FAST, the Five-hundred-meter Aperture Spherical Radio Telescope will be the most sensitive single-dish radio telescope in the low frequency radio bands between 70 MHz and 3 GHz.To take advantage of its giant aperture, all relevant cutting-edge technology should be applied to FAST to ensure that it achieves the best possible overall performance. The wideband receiver that is currently under development can not only be directly applied to FAST, but also used for other Chinese radio telescopes, such as the Shanghai 65-meter telescope and the Xinjiang 110-meter telescope, to ensure that these telescopes are among the best in the world. Recently, rapid development related to this wideband receiver has been underway. In this paper, we will introduce three key aspects of the FAST wideband receiver project. First is the use of a high-performance analog-to-digital converter (ADC). With the cooperation of Hao Jie’s team from the Institute of Automation of the Chinese Academy of Sciences(CASIA), we have developed 3-Gsps,12-bit ADCs, which have not been used previously in astronomy, and we expect to realize the 3-GHz bandwidth in a single step by covering the entire bandwidth via interleaving or a complex fast Fourier transform (FFT).Second is the front-end analog signal integrated circuit board. We wish to achieve a series of amplification, attenuation, and mixing filtering operations on a single small board, thereby achieving digital control of the bandpass behavior both flexibly and highly-efficiently. This design will not only greatly reduce the required cost and power but will also make the best use of the digital-system’s flexibility. Third is optimization of the FFT: the existing FFT is not very efficient; therefore, we will optimize the FFT for large-scale operation. For this purpose, we intend to cascade two FFTs. Another

  10. Radioactive contamination in monitors received for calibration

    International Nuclear Information System (INIS)

    The Calibration Laboratory - LABCAL, from the Research Center for Metrology and Testing - METROBRAS, MRA Comercio de Instrumentos Eletronicos Ltda., began activities in October 2008 and, in August 2009, decided to establish a procedure for monitoring tests, external and internal, of all packages received from customers, containing instruments for calibration. The aim was to investigate possible contamination radioactive on these instruments. On July 2011, this procedure was extended to packagings of personal thermoluminescent dosemeters - TLD, received by the newly created Laboratory Laboratorio de Dosimetria Pessoal - LDP . In the monitoring procedure were used monitors with external probe, type pancake, MRA brand, models GP - 500 and MIR 7028. During the 37 months in which this investigation was conducted, were detected 42 cases of radioactive contamination, with the following characteristics: 1) just one case was personal dosimeter, TLD type; 2) just one case was not from a packing from nuclear medicine service - was from a mining company; 3) contamination occurred on packs and instruments, located and/or widespread; 4) contamination values ranged from slightly above the level of background radiation to about a thousand fold. Although METROBRAS has facilities for decontamination, in most cases, especially those of higher contamination, the procedure followed was to store the contaminated material in a room used for storage of radioactive sources. Periodically, each package and/or instrument was monitored, being released when the radiation level matched the background radiation. Every contamination detected, the client and/or owner of the instrument was informed. The Brazilian National Energy Commission - CNEN, was informed, during your public consultation for reviewing the standard for nuclear medicine services, held in mid-2012, having received from METROBRAS the statistical data available at the time. The high frequency of contamination detected and the high

  11. Eosinophils increase in animals that received biotherapic

    Directory of Open Access Journals (Sweden)

    Pedro Gilberto Silva Morais

    2012-12-01

    Full Text Available Dairy industry is an important Brazilian economic activity participating of income generation. European breeds cattle aren’t adapted to parasites found in the tropics, like the Rhipicephalus microplus tick. Parasites can acquire resistance to allopathic products, but not to homeopathic products. We evaluate the efficacy of an antiparasiticide biotherapic against the R. microplus tick. The biotherapic was prepared according to the homeopathic pharmacopoeia recommendations from vegetable (Abrotanum and animal products (Rhipicephalus microplus, Amblyomma cajenennense, Haematobia irritans, Musca domestica, Dermatobia hominis, all diluted and vigorous shaken (dynamized in water or alcohol at a ratio of 1:99, in the 12th Centesimal Hahnemann (CH12, with limestone as the carrier. This homeophatic product found in veterinary pharmacies of Ituiutaba’s region, Minas Gerais State, is registered at Ministério da Agricultura, Pecuária e Abastecimento (MAPA. Natural tick infestation was accessed in thirty Girolando (Gir x Holstein cows with 7 to 13 year-old, by monthly counting of tick female bigger than 6 mm, from October/2009 to July/2011. Cows were divided in three groups of 10 similar animals. The treated group (T1 received roughage, concentrate and biotherapic. The placebo group (T2 received roughage, concentrate and limestone and the control group (T3 received only roughage and concentrate. T1 and T2 groups were managed together and remained in the same paddock. T3 group was separed from T1 and T2 by a wire fence. From October 2009 to September 2010 blood cell counts and serum biochemical tests were performed monthly only in T1 and T2, but visual clinical observations were made in all animals. Any group was treated with acaricide when the count’s average reached 50 or more ticks. It was necessary 7 baths with acaricide in T1 and T2, while in T3 group (control group it was necessary 19 acaricide baths to control the cattle tick. We verified

  12. Crustal Thickness Across Alaska via Ps Receiver Functions and Gravity Data and Comparison to Lithospheric Structure

    Science.gov (United States)

    O'Driscoll, L.; Saltus, R. W.; Miller, M. S.; Porritt, R. W.

    2015-12-01

    The geologic mosaic of terranes, adjacent multi-phase plate boundary, rapid lateral topographic variations, and heterogeneous distribution of strain throughout Alaska all suggest strong heterogeneity of crustal architecture. We present a model of crustal thickness across the state is primarily constrained where seismic instrumentation has been deployed - dense coverage in the south-central region and sparse coverage in the north, west, and arc regions. P receiver functions (PRF) were calculated using an upgraded version of Funclab, a software module that retrieves data, calculates receiver functions, facilitates quality control, and calculates H-k stacking, depth mapping via binned Common Conversion Point stacking, and other backend products. 1,678 events and 262 stations yielded 102,000 preliminary PRF that were culled to 21,000 total RFs. Iterative time-domain deconvolution was performed about a 1 Hz central frequency for ZRT traces. Our model reproduces many of the Moho depth variations previously modeled by receiver functions and gravity. Thick (>60 km) crust below the Chugach and St. Elias Ranges transitions to ~40 km thick crust south of the Denali Fault. Immediately to the north, thin (29-35) crust is observed in central Alaska between the Alaska and Brooks Ranges. The central Brooks Range is observed to have a thick crustal root below its topographic high axis. Stations scattered throughout western Alaska and the Bering Sea regions generally show average (~35 km) thickness crust while displaying inter-station uniqueness in the form of stacked RFs. Below the forearc and central Alaska Range, the Yakutat slab Moho is also observed. To complete coverage for the state we use a gravity Moho model calibrated to our receiver function solutions. The resolution of gravity-derived Moho models is limited and can only produce a smoothed approximation of the actual Moho. Where receiver function results are dense we observe significant complexity to the Moho, consistent

  13. Remote bistatic receiver synchronization using DLL techniques

    Science.gov (United States)

    Aguasca, A.; Broquetas, A.; Fdez de Muniain, J.; Ambros, A.

    An experimental staggered pulse repetition frequency synchronizer, based on a delay-lock loop (DLL) was tested using a transmitter signal simulator that simulates the staggering sequence windowed by the antenna beam. The measured system performance ensures synchronization with a 30-ms direct illumination, with an accumulated delay error in the order of the resolution cell positioning error in range. An artificial time expansion of the received pulses is performed in order to reduce the acquisition time synchronization. A bistatic radar synchronization method based on DLL was is analyzed by linearization of the different parts and signals involved. The parameters that degrade system performance are obtained. And some solutions are represented in order to minimize their effects.

  14. Receiver based PAPR reduction in OFDMA

    KAUST Repository

    Ali, Anum Z.

    2014-05-01

    High peak-to-average power ratio is one of the major drawbacks of orthogonal frequency division multiplexing (OFDM). Clipping is the simplest peak reduction scheme, however, it requires clipping mitigation at the receiver. Recently compressed sensing has been used for clipping mitigation (by exploiting the sparse nature of clipping signal). However, clipping estimation in multi-user scenario (i.e., OFDMA) is not straightforward as clipping distortions overlap in frequency domain and one cannot distinguish between distortions from different users. In this work, a collaborative clipping removal strategy is proposed based on joint estimation of the clipping distortions from all users. Further, an effective data aided channel estimation strategy for clipped OFDM is also outlined. Simulation results are presented to justify the effectiveness of the proposed schemes. © 2014 IEEE.

  15. The BINP receives its Golden Hadron award

    CERN Multimedia

    2002-01-01

    On Thursday, 14 September, the LHC Project Leader, Lyn Evans, handed over a Golden Hadron award to Alexander Skrinsky of Russia's Budker Institute of Nuclear Physics (BINP). The prize is awarded in recognition of exceptional performances by suppliers and this year prizes were awarded to two firms, Cockerill-Sambre (Belgium) and Wah-Chang (United States), and to the Budker Institute, which was unable to receive the award at the same time as the two other recipients (see Bulletin No 34/2002, of 19 August 2002). The Russian institute has been rewarded for the particularly high-quality production of 360 dipole magnets and 185 quadrupole magnets for the LHC proton beam transfer lines.

  16. MRI in children receiving total parenteral nutrition

    International Nuclear Information System (INIS)

    Cranial MRI was obtained in 13 of a group of 57 children receiving long-term parenteral nutrition, who were being investigated for hypermanganasaemia. Increased signal intensity on T1-weighted images has been reported in adult patients on long-term parenteral nutrition and with encephalopathy following chronic manganese exposure in arc welding. It has been postulated that these changes are due to deposition of the paramagnetic trace element manganese. In excess manganese is hepato- and neurotoxic and we present the correlation of whole blood manganese levels with imaging findings. The age range of our patients was 6 months to 10 years, and the duration of therapy 3 months to 10 years. In 7 children we found characteristic increased signal intensity on T1-weighted images, with no abnormality on T2-weighted images. All patients had elevated whole blood manganese levels, suggesting that the basis for this abnormality is indeed deposition of manganese within the tissues. (orig.). With 3 figs

  17. Partitioned-Interval Quantum Optical Communications Receiver

    Science.gov (United States)

    Vilnrotter, Victor A.

    2013-01-01

    The proposed quantum receiver in this innovation partitions each binary signal interval into two unequal segments: a short "pre-measurement" segment in the beginning of the symbol interval used to make an initial guess with better probability than 50/50 guessing, and a much longer segment used to make the high-sensitivity signal detection via field-cancellation and photon-counting detection. It was found that by assigning as little as 10% of the total signal energy to the pre-measurement segment, the initial 50/50 guess can be improved to about 70/30, using the best available measurements such as classical coherent or "optimized Kennedy" detection.

  18. Jiang Zemin Receives New ACWF Leadership

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    FOUR days after the adjournment of the 8th Chinese Women’s National Congress, President Jiang Zemin received all the newly-elected members of the executive committee and several deputies at Zhongnanhai. Gu Xiulian, Vice President and the First Member of the Secretariat of the All-China Women’s Federation (ACWF), briefed Jiang on the congress. She said deputies had reached consensus on certain issues: that women should capitalize on their abilities in the overall social participation; that the uplifting of women’s quality should be seen as a long-term strategy; and that women’s development requires a supportive social environment. Jiang Zemin listened attentively to the speeches delivered by seven deputies. Jiang Daguo, president of Hubei Provincial Women’s Federation, from one of the

  19. Humboldt SK pilot biodigester receives funding

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2005-09-30

    The Canada-Saskatchewan Western Economic Partnership Agreement (WEPA) will provide funding for Canada's first pilot-scale biodigester to be built in Humboldt, Saskatchewan. The $208,138 pilot facility will use household garbage as well as agricultural waste such as manure and livestock operations, abattoirs and food processing to create heat or power and fertilizer. Support for this bio-energy facility, which could also reduce greenhouse gases, will come from the Prairie Agricultural Machinery Institute which has received $186,138 from Canada and Saskatchewan in the form of cost-shared federal-provincial funding. The pilot plant will test different combinations of waste material feedstocks and the characteristics of the resulting gas end products. The pilot facility will also provide design information for full-scale biodigester manufacturers in Canada. It is expected that 25 full-scale biodigesters will be constructed in Canada in the near future.

  20. Listeriosis in patients receiving biologic therapies.

    Science.gov (United States)

    Bodro, M; Paterson, D L

    2013-09-01

    The evolution of inflammatory diseases has radically changed since the introduction of biologic therapies, such as tumour necrosis factor alpha inhibitors (anti-TNFα). They, therefore, represent a widely used therapeutic modality. Nevertheless, post-marketing studies reveal an increased risk of infection in patients taking these drugs, especially granulomatous infections such as listeriosis. We aimed to evaluate the reported cases of listeriosis in patients treated with biologic treatments. We used the United States Food and Drug Administration (FDA) Adverse Event Reporting System (AERS) from 2004 to 2011. We also perform a literature review of previously reported cases of listeriosis in patients taking biologic therapies. We identified 266 cases of Listeria monocytogenes infection associated with biologic therapies. The majority of patients were receiving infliximab (77.1 %), followed by etanercept (11.7 %), adalimumab (9.8 %), rituximab (4.1 %), abatacept (0.4 %) and golimumab (0.4 %). Indications for the use of biologics were as follows: 47.7 % for rheumatologic diseases, 38 % for inflammatory bowel diseases, 3.4 % for haematological diseases and 10.5 % for other indications. Seventy-three percent of the patients were receiving concomitant immunosuppressant drugs, especially steroids (56 %) and methotrexate (31.6 %). The median time to the onset of infection was 184 days. Mortality rates range from 11.1 % in adalimumab-treated patients to 27.3 % in rituximab-treated patients (p = 0.7). Listeriosis is common in biologics-treated patients, especially related to infliximab use given concomitantly with other immunosuppressive therapies. Infections after treatment with biologics mostly occurred in the first year after initiating treatment. PMID:23568606

  1. CENTRAL PLATEAU REMEDIATION

    Energy Technology Data Exchange (ETDEWEB)

    ROMINE, L.D.

    2006-02-01

    A systematic approach to closure planning is being implemented at the Hanford Site's Central Plateau to help achieve the goal of closure by the year 2035. The overall objective of Central Plateau remediation is to protect human health and the environment from the significant quantity of contaminated material that resulted from decades of plutonium production in support of the nation's defense. This goal will be achieved either by removing contaminants or placing the residual contaminated materials in a secure configuration that minimizes further migration to the groundwater and reduces the potential for inadvertent intrusion into contaminated sites. The approach to Central Plateau cleanup used three key concepts--closure zones, closure elements, and closure process steps--to create an organized picture of actions required to complete remediation. These actions were merged with logic ties, constraints, and required resources to produce an integrated time-phased schedule and cost profile for Central Plateau closure. Programmatic risks associated with implementation of Central Plateau closure were identified and analyzed. Actions to mitigate the most significant risks are underway while high priority remediation projects continue to make progress.

  2. Colloquium on Central Asia

    International Nuclear Information System (INIS)

    This colloquium on Azerbaijan was organized by the direction of international relations of the French Senate and the French center of foreign trade (CFCE). This document gathers the interventions of the participants and the debates with the audience following these interventions. The topics treated concern: - the present day political-economical situation of Central Asia countries (problem of borders, relations with Russia and China); - the economies of Central Asia countries: short term problems and medium-term perspectives; - the relations with the European Union (political, economical, trade and investments, perspectives); - the European energy stakes of Caspian sea (oil and gas reserves, development of hydrocarbon resources, exploitation and transport constraints, stakes for Europe and France); - TotalFinaElf company in Central Asia (Kazakhstan, Azerbaijan, enclavement problem); - the economical impacts of the TRACECA pathway (Transport Corridor Europe Caucasus Asia). (J.S.)

  3. SOCRATES Invades Central Europe

    Directory of Open Access Journals (Sweden)

    Joseph Slowinski

    1998-04-01

    Full Text Available The objective of this article is to explore the current reality faced by higher education students in Central and Eastern Europe and to draw out the implications of this current reality for policy makers in the future. In the article, I explore the influence of transnational corporations' training programs on education as it currently pertains to Central and Eastern European higher education and employment. In addition, multinational corporate entities exercise influence on European Union policy through the role of lobby organizations and activities. I explore the influence of these practices on education with an emphasis on the emerging importance of Western language skills. In addition, I focus on the European Union and its efforts to expand into Central and Eastern Europe in order to provide a focal point for analysis.

  4. The Naive Central Banker

    Directory of Open Access Journals (Sweden)

    Marcelo de Carvalho Griebeler

    2015-09-01

    Full Text Available There has been in some countries a trend of assigning other functions to central banks besides price stability. The most suggested function to be added to monetary authority’s obligations is to pursue economic growth or full employment. In this paper we characterize the behavior and analyse the optimal monetary policy of, what we call, a naive central banker. We describe the naive behavior as one that does face the inflation-unemployment trade-off, but it tries to minimize both variables simultaneously. Our findings, both under discretion and commitment, indicate that the naive central banker delivers lower expected inflation and inflation variance than the benchmark behavior whenever the economy is rigid enough. However, the degree of conservativeness also affects this result, such that the less conservative the naive policymaker, the more rigidity is necessary.

  5. Hale Central Peak

    Science.gov (United States)

    2004-01-01

    19 September 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows some of the mountains that make up the central peak region of Hale Crater, located near 35.8oS, 36.5oW. Dark, smooth-surfaced sand dunes are seen to be climbing up the mountainous slopes. The central peak of a crater consists of rock brought up during the impact from below the crater floor. This autumn image is illuminated from the upper left and covers an area approximately 3 km (1.9 mi) across.

  6. Central Bank independence

    Directory of Open Access Journals (Sweden)

    Vasile DEDU

    2012-08-01

    Full Text Available In this paper we present the key aspects regarding central bank’s independence. Most economists consider that the factor which positively influences the efficiency of monetary policy measures is the high independence of the central bank. We determined that the National Bank of Romania (NBR has a high degree of independence. NBR has both goal and instrument independence. We also consider that the hike of NBR’s independence played an important role in the significant disinflation process, as headline inflation dropped inside the targeted band of 3% ± 1 percentage point recently.

  7. Several Centuries of Centrality

    OpenAIRE

    Roth, Dana L.

    2015-01-01

    As Carolyn Bertozzi mentioned in her inaugural editorial, the relationship of “Central Science” to “Chemistry” became popularized over 40 years ago with the publication of the first edition of Brown and LeMay’s Chemistry: The Central Science, now in its 13th edition. Yet as late as 2003, Prof. Sason Shaik at The Hebrew University claimed “popularization of chemistry remains scant.” He goes on to share [his] “own experience of popularizing chemistry by delivering the following universal messag...

  8. ORIC central region calculations

    International Nuclear Information System (INIS)

    The central region for the K = 100 Oak Ridge Isochronous Cyclotron, ORIC, will be modified to provide better orbit centering, focusing of orbits in the axial direction, and phase selection, in order to improve extraction efficiency, and reduce radioactive activation of cyclotron components. The central region is specifically designed for the acceleration of intense light ion beams such as 60 MeV protons and 15--100 MeV alphas. These beams will be used in the production of radioactive atoms in the Radioactive Ion Beam Project at Oak Ridge National Laboratory

  9. Disseminated encephalomyelitis-like central nervous system neoplasm in childhood.

    Science.gov (United States)

    Zhao, Jianhui; Bao, Xinhua; Fu, Na; Ye, Jintang; Li, Ting; Yuan, Yun; Zhang, Chunyu; Zhang, Yao; Zhang, Yuehua; Qin, Jiong; Wu, Xiru

    2014-08-01

    A malignant neoplasm in the central nervous system with diffuse white matter changes on magnetic resonance imaging (MRI) is rare in children. It could be misdiagnosed as acute disseminated encephalomyelitis. This report presents our experience based on 4 patients (3 male, 1 female; aged 7-13 years) whose MRI showed diffuse lesions in white matter and who were initially diagnosed with acute disseminated encephalomyelitis. All of the patients received corticosteroid therapy. After brain biopsy, the patients were diagnosed with gliomatosis cerebri, primitive neuroectodermal tumor and central nervous system lymphoma. We also provide literature reviews and discuss the differentiation of central nervous system neoplasm from acute disseminated encephalomyelitis.

  10. Flux Density Measurement on Large-Scale Receivers

    OpenAIRE

    Röger, Marc; Herrmann, Patrik; Ebert, Miriam; Prahl, Christoph; Ulmer, Steffen; Göhring, Felix

    2011-01-01

    Commercial solar tower plants have much larger aperture surfaces than the receiver prototypes tested in earlier R&D projects. Existing methods to measure the solar flux density in the receiver aperture face new challenges regarding the receiver size. Also, the requirements regarding costs, accuracy, spatial resolution, and measuring speed are different. Flux density measurement delivers the spatial distribution of the concentrated solar radiation on a receiver aperture, measures receiver inpu...

  11. Patrick Janot receives the CNRS silver medal

    CERN Multimedia

    2005-01-01

    Patrick Janot during the award ceremony. (Photo Schwemling, Paris) On 25 November, Patrick Janot of the CERN Physics Department received the CNRS silver medal for IN2P3 (Institut national de physique nucléaire et de physique des particules). This prize, one of the most prestigious awarded by the French research centre, is given to scientists for the 'originality, quality and importance of their work, as recognised both nationally and internationally'. Patrick Janot joined the ALEPH collaboration, one of the four experiments at LEP, then under construction, in 1987. First a CERN Fellow, he went on to work for the CNRS at LAL in 1989. Together with his team, he developed innovative algorithms for the reconstruction of events. This work and others earned him the bronze CNRS medal in 1993, which is awarded to scientists for their first achievements. In 1997, he became a permanent physicist at CERN, where he continued to work for ALEPH. He was appointed LEP scientific co-ordinator for the last two years of the ac...

  12. Animal choruses emerge from receiver psychology

    Science.gov (United States)

    Greenfield, Michael D.; Esquer-Garrigos, Yareli; Streiff, Réjane; Party, Virginie

    2016-01-01

    Synchrony and alternation in large animal choruses are often viewed as adaptations by which cooperating males increase their attractiveness to females or evade predators. Alternatively, these seemingly composed productions may simply emerge by default from the receiver psychology of mate choice. This second, emergent property hypothesis has been inferred from findings that females in various acoustic species ignore male calls that follow a neighbor’s by a brief interval, that males often adjust the timing of their call rhythm and reduce the incidence of ineffective, following calls, and from simulations modeling the collective outcome of male adjustments. However, the purported connection between male song timing and female preference has never been tested experimentally, and the emergent property hypothesis has remained speculative. Studying a distinctive katydid species genetically structured as isolated populations, we conducted a comparative phylogenetic analysis of the correlation between male call timing and female preference. We report that across 17 sampled populations male adjustments match the interval over which females prefer leading calls; moreover, this correlation holds after correction for phylogenetic signal. Our study is the first demonstration that male adjustments coevolved with female preferences and thereby confirms the critical link in the emergent property model of chorus evolution. PMID:27670673

  13. CERN Web Pages Receive a Makeover

    CERN Multimedia

    2001-01-01

    Asudden allergic reaction to the colour turquoise? Never fear, from Monday 2 April you'll be able to click in the pink box at the top of the CERN users' welcome page to go to the all-new welcome page, which is simpler and better organized. CERN's new-look intranet is the first step in a complete Web-makeover being applied by the Web Public Education (WPE) group of ETT Division. The transition will be progressive, to allow users to familiarize themselves with the new pages. Until 17 April, CERN users will still get the familiar turquoise welcome page by default, with the new pages operating in parallel. From then on, the default will switch to the new pages, with the old ones being finally switched off on 25 May. Some 400 pages have received the makeover treatment. For more information about the changes to your Web, take a look at: http://www.cern.ch/CERN/NewUserPages/ Happy surfing!

  14. CERN safety expert receives international award

    CERN Multimedia

    2005-01-01

    On 18 December 2004, the President of the Swiss Electro-technical Committee, Martin Reichle (left), presented the award to Helmut Schönbacher. Helmut Schönbacher, of the Safety Commission at CERN, has received, the "1906 Award" of the International Electrotechnical Commission (IEC) for his standardisation work on the influence of ionizing radiation on insulating materials. From 1986 until 2004, Schönbacher was leader of a working group on radiation composed of internationally recognised experts. It edited standards of the IEC 60544 series on the determination of the effects of ionizing radiation on electrical insulating materials. The working group also edited three IEC Technical Reports on the determination of long-term radiation ageing in polymers. This standardisation work and long-term experience from CERN on the radiation ageing of materials also contributed to research coordination programmes of the International Atomic Energy Agency (IAEA). From 1968 until 1988, Schönbacher was a member of the Rad...

  15. Social Interactions Receive Priority to Conscious Perception.

    Science.gov (United States)

    Su, Junzhu; van Boxtel, Jeroen J A; Lu, Hongjing

    2016-01-01

    Humans are social animals, constantly engaged with other people. The importance of social thought and action is hard to overstate. However, is social information so important that it actually determines which stimuli are promoted to conscious experience and which stimuli are suppressed as invisible? To address this question, we used a binocular rivalry paradigm, in which the two eyes receive different action stimuli. In two experiments we measured the conscious percept of rival actions and found that actions engaged in social interactions are granted preferential access to visual awareness over non-interactive actions. Lastly, an attentional task that presumably engaged the mentalizing system enhanced the priority assigned to social interactions in reaching conscious perception. We also found a positive correlation between human identification of interactive activity and the promotion of socially-relevant information to visual awareness. The present findings suggest that the visual system amplifies socially-relevant sensory information and actively promotes it to consciousness, thereby facilitating inferences about social interactions. PMID:27509028

  16. Thermo-mechanical and optical optimization of the molten salt receiver for a given heliostat field

    Science.gov (United States)

    Augsburger, Germain; Das, Apurba K.; Boschek, Erik; Clark, Michael M.

    2016-05-01

    The tower type molten salt solar thermal power plant has proven to be advantageous over other utility scale solar power plant configurations due to its scalability and provision of storage, thereby improving the dispatchability. The configuration consists of a molten salt central receiver (MSCR) located atop an optimally located tower within a heliostat field with thousands of mirrors. The MSCR receives the concentrated energy from the heliostat field which heats a molten salt heat transfer fluid for thermal storage and utilization in producing steam as and when required for power generation. The MSCR heat transfer surface consists of banks of tangent tubes arranged in panels. The combined cost of the heliostat field and the receiver is 40%-50% of the total plant cost, which calls for optimization to maximize their utilization. Several previous studies have looked into the optimum solar power plant size based on various site conditions. However, the combined optimization of the receiver and the heliostat field has not been reported before. This study looks into the optimum configuration of the receiver for a given heliostat field. An in-house tool has been developed to select and rank a few receiver surface configurations (typically <50) from a list of hundreds of thousands of possible options. The operating limits which the heliostat field needs to obey are defined for the ranked surface configurations based on several different design considerations (e.g. mechanical integrity, corrosion limits). The thermal output of the receiver configurations for a given heliostat field is maximized. A combined rank indicating the optimum configurations in descending order of preference is presented based on the performance and various other practical considerations (e.g. total surface area, cost of material, ability of aiming strategies to distribute the flux). The methodology thus provided can be used as a guideline to arrive at an optimum receiver configuration for a given

  17. Retiring the central executive.

    Science.gov (United States)

    Logie, Robert H

    2016-10-01

    Reasoning, problem solving, comprehension, learning and retrieval, inhibition, switching, updating, or multitasking are often referred to as higher cognition, thought to require control processes or the use of a central executive. However, the concept of an executive controller begs the question of what is controlling the controller and so on, leading to an infinite hierarchy of executives or "homunculi". In what is now a QJEP citation classic, Baddeley [Baddeley, A. D. (1996). Exploring the central executive. Quarterly Journal of Experimental Psychology, 49A, 5-28] referred to the concept of a central executive in cognition as a "conceptual ragbag" that acted as a placeholder umbrella term for aspects of cognition that are complex, were poorly understood at the time, and most likely involve several different cognitive functions working in concert. He suggested that with systematic empirical research, advances in understanding might progress sufficiently to allow the executive concept to be "sacked". This article offers an overview of the 1996 article and of some subsequent systematic research and argues that after two decades of research, there is sufficient advance in understanding to suggest that executive control might arise from the interaction among multiple different functions in cognition that use different, but overlapping, brain networks. The article concludes that the central executive concept might now be offered a dignified retirement.

  18. Ecodesign in Central America

    NARCIS (Netherlands)

    Crul, M.R.M.

    2003-01-01

    This PhD thesis describes and analyses the change process started by the Ecodesign project in Central America, executed between 1998 and 2002. The project started using the concept and praxis developed in Europe. Nine ecodesign projects were performed in industry, and ecodesign was introduced to cou

  19. Retiring the central executive.

    Science.gov (United States)

    Logie, Robert H

    2016-10-01

    Reasoning, problem solving, comprehension, learning and retrieval, inhibition, switching, updating, or multitasking are often referred to as higher cognition, thought to require control processes or the use of a central executive. However, the concept of an executive controller begs the question of what is controlling the controller and so on, leading to an infinite hierarchy of executives or "homunculi". In what is now a QJEP citation classic, Baddeley [Baddeley, A. D. (1996). Exploring the central executive. Quarterly Journal of Experimental Psychology, 49A, 5-28] referred to the concept of a central executive in cognition as a "conceptual ragbag" that acted as a placeholder umbrella term for aspects of cognition that are complex, were poorly understood at the time, and most likely involve several different cognitive functions working in concert. He suggested that with systematic empirical research, advances in understanding might progress sufficiently to allow the executive concept to be "sacked". This article offers an overview of the 1996 article and of some subsequent systematic research and argues that after two decades of research, there is sufficient advance in understanding to suggest that executive control might arise from the interaction among multiple different functions in cognition that use different, but overlapping, brain networks. The article concludes that the central executive concept might now be offered a dignified retirement. PMID:26821744

  20. Testing for central symmetry

    NARCIS (Netherlands)

    Einmahl, John; Gan, Zhuojiong

    2016-01-01

    Omnibus tests for central symmetry of a bivariate probability distribution are proposed. The test statistics compare empirical measures of opposite regions. Under rather weak conditions, we establish the asymptotic distribution of the test statistics under the null hypothesis; it follows that they a

  1. Central areolar choroidal dystrophy.

    NARCIS (Netherlands)

    Boon, C.J.F.; Klevering, B.J.; Cremers, F.P.M.; Zonneveld-Vrieling, M.N.; Theelen, T.; Hollander, A.I. den; Hoyng, C.B.

    2009-01-01

    OBJECTIVE: To describe the clinical characteristics, follow-up data and molecular genetic background in a large group of patients with central areolar choroidal dystrophy (CACD). DESIGN: Retrospective case series study. PARTICIPANTS: One hundred three patients with CACD from the Netherlands. METHODS

  2. Central Nervous System Involvement by Multiple Myeloma

    DEFF Research Database (Denmark)

    Jurczyszyn, A.; Gozzetti, A.; Cerase, A.;

    2015-01-01

    Introduction: Central nervous system (CNS) involvement by multiple myeloma (MM) is a rare occurrence and is found in approximately 1% of MM patients at some time during the course of their disease. At the time of diagnosis, extramedullary MM is found in 7% of patients, and another 6% may develop....... Results: The median time from MM diagnosis to CNS MM diagnosis was 3 years. Upon diagnosis, 97% patients with CNS MM received frontline therapy, of which 76% received systemic therapy, 36% radiotherapy and 32% intrathecal therapy. The most common symptoms at presentation were visual changes (36...... history of chemotherapy and unfavorable cytogenetic profile, survival of individuals free from these negative prognostic factors can be prolonged due to administration of systemic treatment and/or radiotherapy. Prospective multi-institutional studies are warranted to improve the outcome of patients...

  3. Central nervous system involvement by multiple myeloma

    DEFF Research Database (Denmark)

    Jurczyszyn, Artur; Grzasko, Norbert; Gozzetti, Alessandro;

    2016-01-01

    The multicenter retrospective study conducted in 38 centers from 20 countries including 172 adult patients with CNS MM aimed to describe the clinical and pathological characteristics and outcomes of patients with multiple myeloma (MM) involving the central nervous system (CNS). Univariate......, 97% patients received initial therapy for CNS disease, of which 76% received systemic therapy, 36% radiotherapy and 32% intrathecal therapy. After a median follow-up of 3.5 years, the median overall survival (OS) from the onset of CNS involvement for the entire group was 7 months. Untreated...... untreated patients and patients with favorable cytogenetic profile might be prolonged due to systemic treatment and/or radiotherapy. This article is protected by copyright. All rights reserved....

  4. Hypocupremia in patients receiving total parenteral nutrition.

    Science.gov (United States)

    Bozzetti, F; Inglese, M G; Terno, G; Pupa, A; Sequeira, C; Migliavacca, S

    1983-01-01

    Although hypocupremia is a well-known consequence of long-term total parenteral nutrition (TPN), its incidence as well as the duration of TPN necessary to induce it are still unsettled. The purpose of this study is to review the changes in serum copper level in 25 patients receiving TPN for a period longer than 2 wk (mean duration 6 wk) at the Istituto Nazionale Tumori of Milan and to evaluate the possible relationship of cupremia with the basic disease. Main indications for TPN included enterocutaneous fistulas (11 patients), cancer cachexia (10 patients), radiation enteropathy (two patients), and severe postoperative stricture following esophagogastric resection (two patients). Mean value of serum copper at the beginning of the study was 143 micrograms/100 ml (normal value 65-165 micrograms/100 ml), and the regression analysis showed a mean fall of 5.64 micrograms/100 ml/wk. Hypocupremia occurred in four patients (three with intestinal fistulas and one with radiation obstructive enteritis) at 5th, 6th, 9th, and 6th wk of TPN, respectively. No patient with cancer cachexia developed hypocupremia. No patient with hypocupremia had clinical evidence of a copper deficiency syndrome. We conclude that 1) hypocupremia does not occur within the first month of TPN; 2) its incidence is about 16% in patients intravenously fed for period longer than 2 wk; 3) it is more frequent in patients with enterocutaneous fistulas, whereas it never occurs in patients with cancer cachexia, and 4) it is not necessarily associated to a clinicometabolic syndrome of copper deficiency. Finally, the "nutritional" meaning of serum copper should be questioned in cancer patients since it could represent a "tumor marker."

  5. Commercial Interactions in the Buenos Aires Central Wholesale Produce Market

    NARCIS (Netherlands)

    Arce, A.M.G.; Viteri, M.L.

    2010-01-01

    The Buenos Aires Central Wholesale Produce Market (BACWM) in Argentina supplies 1,500,000 tons of produce yearly to more than 11 million consumers and receives about 13,000 trucks a week from areas within and outside the country. This market faced global transformations with the emergence of superma

  6. 77 FR 1965 - Central Securities Corporation; Notice of Application

    Science.gov (United States)

    2012-01-12

    ... Bonus Stock to Non-employee Directors without restrictions. Immediately following each annual meeting of... continues as a director after, that annual meeting shall receive an award of 500 Shares of Bonus Stock. In... common stock granted as a bonus, and awards denominated in cash. Applicant: Central...

  7. Superior Coherent Receivers for AF Relaying with Distributed Alamouti Code

    KAUST Repository

    Khan, Fahd Ahmed

    2012-01-01

    Coherent receivers are derived for a pilot-symbol aided distributed Alamouti-coded system with imperfect channel state information. The derived coherent receivers do not perform channel estimation but rather use the received pilot signals for decoding. The derived receiver metrics use the statistics of the channel to give improved performance. The performance is further improved by using the decision history. Simulation results show that a performance gain of up to 1.8 dB can be achieved for the new receivers with decision history as compared with the conventional mismatched coherent receiver. © 2011 IEEE.

  8. Testing (HIV). Quick test receives Singapore approval.

    Science.gov (United States)

    1996-04-22

    Hema-Strip HIV 1/2 is a rapid HIV antibody immunoassay developed by Saliva Diagnostic Systems, Inc. (SDS) which can be used by anyone who can read the product insert. The test kit is comprised of a small lancet for a finger stick, a cylindrical tube with a capillary tip and a SDS diagnostic strip inside, and a vial of buffer. Once blood is drawn by the lancet, the capillary tip is placed upon the blood droplet and the blood is automatically drawn into the tube. The tube is then inserted tip first into the vial of buffer. The buffer and blood migrate over the diagnostic strip inside, yielding stable results within 15 minutes. Studies have found Hema-Strip HIV 1/2 to have a sensitivity and specificity greater than 99.4%, as accurate as most conventional HIV tests which require the use of laboratory equipment and trained staff, and possibly hours to produce results. Moreover, the test kit requires neither refrigeration nor special storage. Hema-Strip HIV 1/2 has received a certificate of free sale from the Ministry of Health in Singapore and is now being submitted for regulatory approval in Brazil, China, Russia, India, Malaysia, Thailand, and the UK. SDS products in production include Sero-Strip HIV 1/2, a rapid serum-based HIV antibody test; Omni-SAL, a saliva collector which is the principal sample collection device used by British insurance companies for HIV testing with other confirmatory tests; Omni-Swab, a serrated swab which collects body fluids or cells; Saliva-Sampler, a saliva collection device used for general testing purposes; and Saliva Check, a test which checks the composition of saliva samples. SDS is in the final stages of developing Saliva-Strip HIV-1/2, a rapid saliva-based HIV antibody test. The company also intends to complete development in 1996 of a rapid blood-based antibody test for the Helicobacter pylori bacteria, a pathogen linked to 80% of peptic ulcers and gastric cancers. PMID:12290908

  9. Influences on authorship issues: an evaluation of receiving, not receiving, and rejecting credit.

    Science.gov (United States)

    Seeman, Jeffrey I; House, Mark C

    2010-07-01

    A survey on credit issues was conducted of academic chemists in Ph.D. granting institutions in the United States. Six-hundred faculty members responded representing 16% of the survey recipients. Fifty percent of the respondents reported not receiving appropriate credit for contributions they had made to published projects. Neither the number of years after receiving their Ph.D., their fields of expertise, their total number of publications, nor their total number of single-author publications showed any significant relationship with the perception of not receiving appropriate credit. Twenty percent of the respondents had discovered that they were an author of a paper, after that paper had been submitted to a journal. Forty-nine percent reported that they had asked to have their name deleted as an author. Relationships between these perceptions and academic background factors were examined. For example, respondents who had asked to be removed from authorship were more likely to give authorship or an acknowledgement to others and were also more likely to have had an authorship problem with others, both of these factors being related to longevity as a publishing scientist. PMID:20597017

  10. Improving Dense Network Performance through Centralized Scheduling and Interference Coordination

    DEFF Research Database (Denmark)

    Lopez, Victor Fernandez; Pedersen, Klaus I.; Alvarez, Beatriz Soret;

    2016-01-01

    . Interference management at the receiver is achieved through the use of a Network-Assisted Interference Cancellation and Suppression (NAICS) receiver. In order to further boost the 5th percentile user data rates, the transmission rank at the interferers is selectively reduced by a centralized rank coordination...... and the receiver sides. As a network coordination scheme, we apply a centralized joint cell association and scheduling mechanism based on dynamic cell switching, by which users are not always served by the strongest perceived cell. The method simultaneously resultsin more balanced loads and increased performance...... of up to 80% without a detrimental effect on the median user rates, under the applied assumptions and simulation settings. The gains reach 110% when rank coordination is applied....

  11. Forward central jets correlations

    International Nuclear Information System (INIS)

    The azimuthal correlation between forward and central jets has been measured in pp collisions with the CMS detector at the LHC at the centre-of-mass energy of 7 TeV. The forward jet is required to be reconstructed in the hadronic forward calorimeter, within the pseudo-rapidity 3.2t>35 GeV. The measurement of the azimuthal angle between the jets is performed for different separations in pseudo-rapidity between the jets, with the largest separation being 7.5 units. The measurement is repeated for two subsamples of events, one in which an additional jet is required between the forward and the central jet, and one where the additional jet is vetoed. The measurement is compared to several different Monte Carlo models and tunes.

  12. Central simple Poisson algebras

    Institute of Scientific and Technical Information of China (English)

    SU; Yucai; XU; Xiaoping

    2004-01-01

    Poisson algebras are fundamental algebraic structures in physics and symplectic geometry. However, the structure theory of Poisson algebras has not been well developed. In this paper, we determine the structure of the central simple Poisson algebras related to locally finite derivations, over an algebraically closed field of characteristic zero.The Lie algebra structures of these Poisson algebras are in general not finitely-graded.

  13. FNAL central email systems

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Jack; Lilianstrom, Al; Pasetes, Ray; Hill, Kevin; /Fermilab

    2004-10-01

    The FNAL Email System is the primary point of entry for email destined for an employee or user at Fermilab. This centrally supported system is designed for reliability and availability. It uses multiple layers of protection to help ensure that: (1) SPAM messages are tagged properly; (2) All mail is inspected for viruses; and (3) Valid mail gets delivered. This system employs numerous redundant subsystems to accomplish these tasks.

  14. Measuring Central Bank Communication:

    OpenAIRE

    David Lucca; Francesco Trebbi

    2008-01-01

    We present a new automated, objective and intuitive scoring method to measure the content of central bank communication about future policy rate moves. We apply the methodology to statements released by the Federal Open Market Commitee (FOMC) after monetary policy meetings. Using high-frequency financial data, we find that yields on short-term risk-free nominal rates respond both to changes in policy rates and the content of the statements, whereas, medium and long-term rates only respond to ...

  15. Central nervous system diseases

    International Nuclear Information System (INIS)

    It is shown that roentgenological examination plays an important role in diagnosis of central nervous system diseases in children. The methods of roentgenological examinations are divided into 3 groups: roentgenography without contrast media (conventional roentgenography), roentgenography with artificial contrasting of liquor space (ventriculopneumoencelography, myelography) and contrasting of brain and spinal blood vessels (angiography). Conventional contrastless roentgenography of skull and vertebral column occupies leadership in diagnosis of brain neoplasms and some vascular diseases

  16. Centrally Banked Cryptocurrencies

    OpenAIRE

    Danezis, George; Meiklejohn, Sarah

    2015-01-01

    Current cryptocurrencies, starting with Bitcoin, build a decentralized blockchain-based transaction ledger, maintained through proofs-of-work that also generate a monetary supply. Such decentralization has benefits, such as independence from national political control, but also significant limitations in terms of scalability and computational cost. We introduce RSCoin, a cryptocurrency framework in which central banks maintain complete control over the monetary supply, but rely on a distribut...

  17. Centrally Banked Cryptocurrencies

    OpenAIRE

    Danezis, G.; Meiklejohn, S.

    2016-01-01

    Current cryptocurrencies, starting with Bitcoin, build a decentralized blockchain-based transaction ledger, maintained through proofs-of-work that also serve to generate a monetary supply. Such decentralization has benefits, such as independence from national political control, but also significant limitations in terms of computational costs and scalability. We introduce RSCoin, a cryptocurrency framework in which central banks maintain complete control over the monetary supply, but rely on...

  18. Centrality Measures in Networks

    CERN Document Server

    Bloch, Francis; Tebaldi, Pietro

    2016-01-01

    We show that although the prominent centrality measures in network analysis make use of different information about nodes' positions, they all process that information in an identical way: they all spring from a common family that are characterized by the same simple axioms. In particular, they are all based on a monotonic and additively separable treatment of a statistic that captures a node's position in the network.

  19. Active Versus Passive: Receiver Model Transforms for Diffusive Molecular Communication

    CERN Document Server

    Noel, Adam; Makrakis, Dimitrios; Hafid, Abdelhakim

    2016-01-01

    This paper presents an analytical comparison of the active and passive receiver models in diffusive molecular communication. In the active model, molecules are absorbed when they collide with the receiver surface. In the passive model, the receiver is a virtual boundary that does not affect molecule behavior. Two approaches are presented to derive transforms between the active and passive receiver signals. As an example, we unify the two models for an unbounded diffusion-only molecular communication system with a spherical receiver. As time increases in the three-dimensional system, the transform functions have constant scaling factors, such that the receiver models are effectively equivalent. Methods are presented to enable the transformation of stochastic simulations, which are used to verify the transforms and demonstrate that transforming the simulation of a passive receiver can be more efficient and more accurate than the direct simulation of an absorbing receiver.

  20. Noise and intercept point calculation for modern radio receiver planning

    DEFF Research Database (Denmark)

    Iversen, Christian Rye; Kolding, T. E.

    2001-01-01

    The paper presents analytical expressions for determining noise and intercept points for cascaded radio receiver stages. The theory allows for active receiver stages with frequency selectivity and flexible impedance levels. This makes the method highly usable for planning of modem receivers where...... baseband stages significantly influence the overall performance. A simple homodyne receiver example is used to demonstrate the scope of applicability and to exemplify the proposed theory....

  1. Cost Analysis of different Operation strategies for falling particle receivers

    OpenAIRE

    Gobereit, Birgit; Amsbeck, Lars; Buck, Reiner; Singer, Csaba

    2015-01-01

    The potential for highly efficient and cost competitive solar energy collection at high temperatures drives the actual research and development activities for particle tower systems. One promising concept for particle receivers is the falling particle receiver. This paper is related to a particle receiver, in which falling ceramic particles form a particle curtain, which absorbs the concentrated solar radiation. Complex Operation strategies will result in higher receiver costs, for both...

  2. Probing real sensory worlds of receivers with unsupervised clustering.

    Directory of Open Access Journals (Sweden)

    Michael Pfeiffer

    Full Text Available The task of an organism to extract information about the external environment from sensory signals is based entirely on the analysis of ongoing afferent spike activity provided by the sense organs. We investigate the processing of auditory stimuli by an acoustic interneuron of insects. In contrast to most previous work we do this by using stimuli and neurophysiological recordings directly in the nocturnal tropical rainforest, where the insect communicates. Different from typical recordings in sound proof laboratories, strong environmental noise from multiple sound sources interferes with the perception of acoustic signals in these realistic scenarios. We apply a recently developed unsupervised machine learning algorithm based on probabilistic inference to find frequently occurring firing patterns in the response of the acoustic interneuron. We can thus ask how much information the central nervous system of the receiver can extract from bursts without ever being told which type and which variants of bursts are characteristic for particular stimuli. Our results show that the reliability of burst coding in the time domain is so high that identical stimuli lead to extremely similar spike pattern responses, even for different preparations on different dates, and even if one of the preparations is recorded outdoors and the other one in the sound proof lab. Simultaneous recordings in two preparations exposed to the same acoustic environment reveal that characteristics of burst patterns are largely preserved among individuals of the same species. Our study shows that burst coding can provide a reliable mechanism for acoustic insects to classify and discriminate signals under very noisy real-world conditions. This gives new insights into the neural mechanisms potentially used by bushcrickets to discriminate conspecific songs from sounds of predators in similar carrier frequency bands.

  3. Comparison of Adsorbed Skin Dose Received by Patients in Cone Beam Computed Tomography, Spiral and Conventional Computed Tomography Scanninng

    Directory of Open Access Journals (Sweden)

    Rahimi A

    2011-12-01

    Full Text Available Background and Aims: The evaluation of absorbed dose received by patients could give useful information for radiation risk estimation. This study was performed to compare the entrance skin dose received by patients in cone beam computed tomography (CBCT, conventional and spiral computed tomography (CT.Materials and Methods: In this experimental study, 81 calibrated TLD chips were used. the TLD chips were placed on facial, thyroid and end of sternum skin surface in patients referred for CT of the paranasal sinuses(3 TLD chips for each area to estimate the absorbed dose received by central part of radiation field, thyroid and out of field areas, respectively. The data were analyzed using one-way ANOVA and Tukey tests. Results: The dose delivered to the center of irradiated field was about 0.79±0.09 mGy in CBCT technique compared with 16.31±3.71 and 18.84±4.12 mGy for spiral and conventional CT, respectively. The received dose by the out of field areas was about 54 percent of central area dose. There was statistical significant relationship between the imaging modalities and absorbed dose received by patients (P=0.016. The least absorbed dose was for CBCT and the greatest dose was for conventional CT imaging technique.Conclusion: The dose delivered to central area of irradiated field in conventional and spiral CT imaging modalities was about 24 times greater than of that in CBCT. Also, the highest received dose was for central area of radiated field and the lowest dose was for the out of field areas.

  4. 5 CFR 551.425 - Time spent receiving medical attention.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Time spent receiving medical attention... Relation to Other Activities § 551.425 Time spent receiving medical attention. (a) Time spent waiting for and receiving medical attention for illness or injury shall be considered hours of work if: (1)...

  5. Processing In A GPS Receiver To Reduce Multipath Errors

    Science.gov (United States)

    Meehan, Thomas K.

    1994-01-01

    Four techniques of ancillary real-time digital processing of signals in Global Positioning System, GPS, receiver introduced reducing effects of multipath propagation of signals on position estimates produced by receiver. Multipath range errors halved. Applied in addition to other signal-processing techniques and to other techniques designing as receiving antenna to make it insensitive to reflections of GPS signals from nearby objects.

  6. SERUM SODIUM CHANGES IN NEONATES RECEIVING PHOTOTHERAPY FOR NEONATAL HYPERBILIRUBINEMIA

    OpenAIRE

    Sunil Kumar; Uday Shankar

    2015-01-01

    BACKGROUND : Neonates receiving phototherapy have side effects like hypocalcemia and electrolyte changes. Our study is hereby intended to study the serum sodium changes due to phototherapy. AIMS : To evaluate the serum sodium changes in neonates receiving phototherapy f or neonatal hyperbilirubinemia. SETTINGS AND DESIGN : A prospective hospital based comparative study conducted on neonates admitted in the Neonatal Intensive Care Unit receiving photot...

  7. The correlated track receiver of tone track circuits

    OpenAIRE

    Goncharov, K. V.

    2011-01-01

    The work is devoted to further improvement of processing algorithm of checking signals of rail line. The simulation modeling of correlation track receiver of tone rail circuits has been executed; the benchmark analysis of correlation receiver and direct amplifier receiver has been executed.

  8. THE CORRELATED TRACK RECEIVER OF TONE TRACK CIRCUITS

    Directory of Open Access Journals (Sweden)

    K. V. Goncharov

    2011-05-01

    Full Text Available The work is devoted to further improvement of processing algorithm of checking signals of rail line. The simulation modeling of correlation track receiver of tone rail circuits has been executed; the benchmark analysis of correlation receiver and direct amplifier receiver has been executed.

  9. Time Domain Analysis of Transmit/Receive Dipole Pair Array

    Institute of Scientific and Technical Information of China (English)

    Zheng Li-zhi; Xiao Bo-xur; Zhu Guo-qiang; Yang Zi-jie

    2003-01-01

    We introduce a new transmit/receive dipole pair array to obtain a compact quasi-monostatic antenna structure for ground penetrating radar systems. And we analyze this transmit/receive dipole pair array in time domain. The numerical results show that if the distance between the transmit antenna and receive antenna is appropriate the array configuration is adoptable.

  10. 7 CFR 400.209 - Electronic transmission and receiving system.

    Science.gov (United States)

    2010-01-01

    ... Contract-Standards for Approval § 400.209 Electronic transmission and receiving system. Any Contractor under the Contract is required to: (a) Adopt a plan for the purpose of transmitting and receiving... 7 Agriculture 6 2010-01-01 2010-01-01 false Electronic transmission and receiving system....

  11. A Bluetooth-enabled HiperLAN/2 receiver

    NARCIS (Netherlands)

    Schiphorst, R.; Hoeksema, F.W.; Slump, C.H.

    2003-01-01

    n our SDR project we aim to combine a GFSK receiver (Bluetooth) with an OFDM receiver (HiperLAN/2). Other WLAN standards use the same frequency bands and modulation techniques. So our Bluetooth-enabled HiperLAN/2 receiver can easily be adapted to other WLAN standards. This paper focuses on the integ

  12. A Bluetooth-enabled HiperLan/2 Receiver

    NARCIS (Netherlands)

    Schiphorst, R.; Hoeksema, F.W.; Slump, C.H.

    2003-01-01

    In our SDR project we aim to combine a GFSK receiver (Bluetooth) with an OFDM receiver (HiperLAN/2). Other WLAN standards use the same frequency bands and modulation techniques. So our Bluetooth-enabled HiperLAN/2 receiver can easily be adapted to other WLAN standards. This paper focuses on the inte

  13. 47 CFR 80.290 - Auxiliary receiving antenna.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Auxiliary receiving antenna. 80.290 Section 80... antenna. An auxiliary receiving antenna must be provided when necessary to avoid unauthorized interruption or reduced efficiency of the required watch because the normal receiving antenna is not...

  14. Micropower RF transponder with superregenerative receiver and RF receiver with sampling mixer

    Science.gov (United States)

    McEwan, Thomas E.

    1997-01-01

    A micropower RF transdponder employs a novel adaptation of the superregenerative receiver wherein the quench oscillator is external to the regenerative transistor. The quench oscillator applies an exponentially decaying waveform rather than the usual sinewave to achieve high sensitivity at microampere current levels. Further improvements include circuit simplifications for antenna coupling, extraction of the detected signal, and a low-voltage bias configuration that allows operation with less than a 1-volt rail voltage. The inventive transponder is expected to operate as long as the battery shelf life.

  15. Micropower RF transponder with superregenerative receiver and RF receiver with sampling mixer

    Science.gov (United States)

    McEwan, T.E.

    1997-05-13

    A micropower RF transponder employs a novel adaptation of the superregenerative receiver wherein the quench oscillator is external to the regenerative transistor. The quench oscillator applies an exponentially decaying waveform rather than the usual sinewave to achieve high sensitivity at microampere current levels. Further improvements include circuit simplifications for antenna coupling, extraction of the detected signal, and a low-voltage bias configuration that allows operation with less than a 1-volt rail voltage. The inventive transponder is expected to operate as long as the battery shelf life. 13 figs.

  16. Identifying Central Bank Liquidity Super-Spreaders in Interbank Funds Networks

    NARCIS (Netherlands)

    Leon Rincon, C.E.; Machado, C.; Sarmiento Paipilla, N.M.

    2015-01-01

    We model the allocation of central bank liquidity among the participants of the interbank market by using network analysis’ metrics. Our analytical framework considers that a super-spreader simultaneously excels at receiving (borrowing) and distributing (lending) central bank’s liquidity for the who

  17. Moments Of Microdiversity EGC Receivers And Macrodiversity SC Receiver Output Signal Over Gamma Shadowed Nakagami-m Multipath Fading Channel

    Science.gov (United States)

    Djordjević, Nebojša; Jaksić, Branimir S.; Matović, Ana; Matović, Marija; Smilić, Marko

    2015-11-01

    A system with macrodiversity selection combining (SC) receiver and for microdiversity equal gain combining (EGC) receivers is considered. Received signal is subjected, simultaneously to multipath fading and shadowing, resulting in signal envelope and signal power variation. Closed form expressions for moments of macrodiversity SC receiver output signal envelope are calculated. Numerical expressions are plotted to present the influences of Gamma shadowing severity and Nakagami-m severity on moments of proposed system output signal.

  18. Central effects of fingolimod.

    Science.gov (United States)

    Cruz, Vítor T; Fonseca, Joaquim

    2014-08-01

    Introduccion. El fingolimod, un modulador del receptor de la esfingosina-1-fosfato (S1P) dotado de un mecanismo de accion novedoso, fue el primer tratamiento oral aprobado para la esclerosis multiple remitente recurrente. Su union a los receptores S1P1 de los linfocitos promueve la retencion selectiva de los linfocitos T virgenes y de memoria central en los tejidos linfoides secundarios, lo que impide su salida hacia el sistema nervioso central (SNC). Asimismo, el fingolimod atraviesa con facilidad la barrera hematoencefalica, y diversos estudios le atribuyen un efecto neuroprotector directo en el SNC. Objetivo. Revisar la informacion disponible acerca de los efectos centrales del fingolimod. Desarrollo. El desequilibrio entre los procesos lesivos y reparadores constituye un reflejo de la desmielinizacion cronica, la degeneracion axonal y la gliosis, y parece contribuir a la discapacidad que la esclerosis multiple acarrea. La facilidad con la que el fingolimod atraviesa la barrera hematoencefalica le permite actuar directamente sobre los receptores S1P localizados en las celulas del SNC. Una vez en el interior del SNC, ocupa los receptores S1P de los oligodendrocitos y de sus celulas precursoras, de los astrocitos, los microgliocitos y las neuronas, fomentando la remielinizacion, la neuroproteccion y los procesos endogenos de regeneracion. La eficacia evidenciada en los ensayos clinicos concuerda con un mecanismo de accion que incluiria efectos directos sobre las celulas del SNC. Conclusiones. Los datos disponibles indican que la eficacia del fingolimod en el tratamiento de la esclerosis multiple se debe a su ambivalencia como molecula inmunomoduladora y moduladora directa de los receptores S1P del SNC. Tanto es asi que estudios recientes le atribuyen efectos neuroprotectores en varios modelos que suscitan expectativas en torno a su posible aplicacion terapeutica en la enfermedad de Alzheimer, el paludismo cerebral y el neuroblastoma, asi como en la neuroproteccion

  19. [Central anticholinergic syndrome].

    Science.gov (United States)

    Fernández Urretavizcaya, P; Cenoz Osinaga, J C; Jáuregui Garía, M L; Gállego Culleré, J

    1991-10-01

    Two new cases of anticolinergic central syndrome are described. The first case, a 8 year old girl, suffered a severe encefalopathy after topical application of mydriatic cholirio as an aid in a rutine study of ocular refraction. The second case, 67 year old man presented a severe neurological picture after accidental intake of a silvester plantground (Atropa belladonna). His neurological condition returned quickly to normal whith administration of physostigmine. Differents aspects of the etiology, clinical picture and diagnosis are discussed with special emphasis in patients with delirium or acute confusional states. Finally, attention is drawn in the necessity of a properly use of anticholinergic drugs overcoat in aged or children.

  20. Flooding in Central Siberia

    Science.gov (United States)

    2002-01-01

    A mixture of snowmelt and ice jams in late May and June of this year caused the Taz River (left) and the Yenisey River (right) in central Siberia to overflow their banks. The flooding can be seen in this image taken on June 11, 2002, by the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument aboard the Terra satellite. Normally, the rivers would resemble thin black lines in MODIS imagery. In the false-color images sage green and rusty orange is land, and water is black. Clouds are white and pink. Credit: Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  1. Centralized vs. De-centralized Multinationals and Taxes

    DEFF Research Database (Denmark)

    Nielsen, Søren Bo; Raimondos-Møller, Pascalis; Schjelderup, Guttorm

    2005-01-01

    The paper examines how country tax differences affect a multinational enterprise's choice to centralize or de-centralize its decision structure. Within a simple model that emphasizes the multiple conflicting roles of transfer prices in MNEs - here, as a strategic pre-commitment device and a tax m...... manipulation instrument -, we show that (de-)centralized decisions are more profitable when tax differentials are (small) large.Keywords: Centralized vs. de-centralized decisions, taxes, MNEs.JEL-Classification: H25, F23, L23....

  2. en los pivotes centrales

    Directory of Open Access Journals (Sweden)

    Reynaldo Roque Rodés

    2005-01-01

    Full Text Available Se hace una revisión y comentarios sobre las ventajas y limitantes del empleo del LEPA (Low Enery Precision Aplication en los sistemas de riego de pivotes centrales. Estos sistemas o filosofía de manejo del agua para condiciones de escasez o mala calidad del líquido es una alternativa viable para la producción de alimentos. Introducida en la década del 80 en las planicies del sur de Texas, donde la alta evaporación del agua y la necesidad de regar grandes áreas con pivotes centrales obligaba a la búsqueda de una alternativa para incrementar al máximo la eficiencia de aplicación del riego. Aún en fase de estudio e introducción en Cuba para áreas específicas, puede ser una solución de incremento de los rendimientos de los cultivos, empleando menos agua y aguas con calidad limitada

  3. Central Sumatra enjoys success

    Energy Technology Data Exchange (ETDEWEB)

    Wongsosantiko, A.

    1977-05-02

    The Sihapas group contains the most prolific oil producing zones in the Central Sumatra Basin. It represents the transgressive, coarse clastic sequence deposited during the early Miocene. Some of these sandstone grade laterally into siltstones and shales of the Telisa Formation, believed to be a major source of rock for Central Sumatra oil. Recent exploratory wells drilled between the mountain front and coastal plain areas have provided more data for stratigraphic studies. These have resulted in subdivision of the lower Miocene transgressive sequence into discrete rock-stratigraphic units. The former Sihapas Formation has subsequently been elevated to group rank and now consists of several formations with the Duri Formation as the uppermost sand unit. This study covers Caltex's areas of operation, which includes the area between the Kampar River of the south, the Barumum River to the north, the Malacca Straits to the east, and the Barisan Mt. to the west. A basic map shows the regional scene, while a stratigraphic chart shows the lithology.

  4. The ATLAS Level-1 Central Trigger

    CERN Document Server

    Stockton, M; The ATLAS collaboration

    2011-01-01

    The ATLAS Level-1 trigger system is responsible for reducing the anticipated LHC collision rate from 40 MHz to less than 100 kHz. This Level-1 selection identifies, jet, tau/hadron, electron/photon and muon candidates, with additional triggers for missing and total energy. These inputs are used by the Level-1 Central Trigger to form a Level-1 Accept decision. This decision, along with summary information, is then passed into the higher levels of the trigger system and sub-detectors, which also receive the clock from the Level-1 Central trigger. The performance of the Central Trigger during the first collisions will be shown. This includes details of how the trigger information, along with dead-time rates, are monitored and logged by the online system for physics analysis, data quality assurance and operational debugging. Also presented are the software tools used to efficiently display the relevant information in the control room in a way useful for shifters and experts.

  5. The ATLAS level-1 Central Trigger

    CERN Document Server

    Spiwoks, R; Berge, D; Caracinha, D; Ellis, Nick; Farthouat, P; Gällnö, P; Haas, S; Klofver, P; Krasznahorkay, A; Messina, A; Ohm, C; Pauly, T; Perantoni, M; Pessoa Lima Junior, H; Schuler, G; De Seixas, J M; Wengler, T; PH-EP

    2007-01-01

    The ATLAS Level-1 Central Trigger consists of the Muon-to-Central-Trigger-Processor Interface (MUCTPI), the Central Trigger Processor (CTP), and the Timing, Trigger and Control (TTC) partitions of the sub-detectors. The MUCTPI connects the output of the muon trigger system to the CTP. At every bunch crossing it receives information on muon candidates from each of the 208 muon trigger sectors and calculates the total multiplicity for each of six pT thresholds. The CTP combines information from the calorimeter trigger and the MUCTPI and makes the final Level-1 Accept (L1A) decision on the basis of lists of selection criteria (trigger menus). The MUCTPI and the CTP provide trigger summary information to the Level-2 trigger and to the data acquisition (DAQ) for every event selected at the Level-1. They further provide accumulated and, for the CTP, bunch-by-bunch counter data for monitoring of the trigger, detector and beam conditions. The TTC partitions send timing, trigger and control signals from the CTP to the...

  6. Diaphragm pacers as a treatment for congenital central hypoventilation syndrome.

    Science.gov (United States)

    Chen, Maida Lynn; Tablizo, Mary Anne; Kun, Sheila; Keens, Thomas G

    2005-09-01

    Congenital central hypoventilation syndrome is a rare syndrome present from birth, and is defined as the failure of automatic control of breathing. All patients with congenital central hypoventilation syndrome require life-long ventilatory support during sleep, although approximately a third of patients require ventilatory support 24 h per day. Diaphragm pacers offer a modality of ventilatory support that affords congenital central hypoventilation syndrome patients with maximal mobility for full-time ventilatory patients, and they may allow for a more normal lifestyle in the appropriate patient. They may permit tracheostomy decannulation in those requiring only support during sleep. Diaphragm pacing entails surgical placement of an electrode onto the phrenic nerve, connected to a subcutaneous receiver. There is an external battery-operated transmitter and antenna placed on the skin over the receiver. The transmitter emits energy, similar to radio transmission, which is converted into an electrical current by the receiver. This stimulates the phrenic nerve resulting in a diaphragmatic contraction. Settings on the transmitter include respiratory rate and electrical voltage, and are adjusted to give enough tidal volume to allow for adequate oxygenation and ventilation. Therefore, diaphragm pacing is an attractive alternative mode of mechanically assisted ventilation for many patients with congenital central hypoventilation syndrome.

  7. A pseudolite-based positioning system for legacy GNSS receivers.

    Science.gov (United States)

    Kim, Chongwon; So, Hyoungmin; Lee, Taikjin; Kee, Changdon

    2014-03-27

    The ephemeris data format of legacy GPS receivers is improper for positioning stationary pseudolites on the ground. Therefore, to utilize pseudolites for navigation, GPS receivers must be modified so that they can handle the modified data formats of the pseudolites. Because of this problem, the practical use of pseudolites has so far been limited. This paper proposes a pseudolite-based positioning system that can be used with unmodified legacy GPS receivers. In the proposed system, pseudolites transmit simulated GPS signals. The signals use standard GPS ephemeris data format and contain ephemeris data of simulated GPS satellites, not those of pseudolites. The use of the standard format enables the GPS receiver to process pseudolite signals without any modification. However, the position output of the GPS receiver is not the correct position in this system, because there are additional signal delays from each pseudolite to the receiver. A post-calculation process was added to obtain the correct receiver position using GPS receiver output. This re-estimation is possible because it is based on known information about the simulated signals, pseudolites, and positioning process of the GPS receiver. Simulations using generated data and live GPS data are conducted for various geometries to verify the proposed system. The test results show that the proposed system provides the desired user position using pseudolite signals without requiring any modifications to the legacy GPS receiver. In this initial study, a pseudolite-only indoor system was assumed. However, it can be expanded to a GPS-pseudolite system outdoors.

  8. Investigation on the effect of aperture sizes and receiver positions in coupled rooms.

    Science.gov (United States)

    Xiang, Ning; Escolano, Jose; Navarro, Juan M; Jing, Yun

    2013-06-01

    Some recent concert hall designs have incorporated coupled reverberation chambers to the main hall that have stimulated a range of research activities in architectural acoustics. The coupling apertures between two or more coupled-volume systems are of central importance for sound propagation and sound energy decays throughout the coupled-volume systems. In addition, positions of sound sources and receivers relative to the aperture also have a profound influence on the sound energy distributions and decays. This work investigates the effect of aperture size on the behavior of coupled-volume systems using both acoustic scale-models and diffusion equation models. In these physical and numerical models, the sound source and receiver positions relative to the aperture are also investigated. Through systematic comparisons between results achieved from both physical scale models and numerical models, this work reveals valid ranges and limitations of the diffusion equation model for room-acoustic modeling. PMID:23742351

  9. Efficient schemes of joint remote preparation with a passive receiver via EPR pairs

    Science.gov (United States)

    Ma, Song-Ya; Gao, Cong; Luo, Ming-Xing

    2015-11-01

    Novel schemes are put forward to execute the joint remote preparation of an arbitrary two-qubit state with a passive receiver via EPR pairs as the entangled channel. Compared with the previous protocols, the required multi-particle measurement is simplified and the classical communication cost is reduced. When the number of senders increases, the advantage is more evident. It means that the proposed schemes are more efficient in practice. Project supported by the National Natural Science Foundation of China (Grant Nos. 61201253, 61303039, 61572246, and 61502147) and the Fundamental Research Fund for the Central Universities of China (Grant No. 2682014CX095).

  10. Centrality Measures in Urban Networks

    CERN Document Server

    Crucitti, P; Porta, S; Crucitti, Paolo; Latora, Vito; Porta, Sergio

    2005-01-01

    Centrality has revealed crucial for understanding the structural order of complex relational networks. Centrality is also relevant for various spatial factors affecting human life and behaviors in cities. We present a comprehensive study of centrality distributions over geographic networks of urban streets. Four different measures of centrality, namely closeness, betweenness, straightness and information, are compared over eighteen 1-square-mile samples of different world cities. Samples are represented by primal geographic graphs, i.e. valued graphs defined by metric rather than topologic distance where intersections are turned into nodes and streets into edges. The spatial behavior of centrality indexes over the networks is investigated graphically by means of colour-coded maps. The results indicate that a spatial analysis, that we term Multiple Centrality Assessment(MCA), grounded not a single but on a set of different centrality indices, allows an extended comprehension of the city structure, nicely captu...

  11. Centralizer for well casing

    International Nuclear Information System (INIS)

    This patent describes an improved centralizer for centering a well casing in a wellbore. It comprises: a first anchor adapted to fit around and be securely fixed to the casing, the first anchor being threaded on its external surface; a first collar adapted to fit around and be threadedly engaged by the first anchor; a second collar adapted to fit around and free to rotate and move axially with respect to the casing; a second anchor adapted to fit around and be securely fixed to the casing spaced from the first anchor and comprising a bearing surface for restraining axial movement of the second collar along the casing; and metallic straps extending between the first collar and the second collar, and being securely fixed to each

  12. UA2 central calorimeter

    CERN Multimedia

    The UA2 central calorimeter measured the energy of individual particles created in proton-antiproton collisions. Accurate calibration allowed the W and Z masses to be measured with a precision of about 1%. The calorimeter had 24 slices like this one, each weighing 4 tons. The slices were arranged like orange segments around the collision point. Incoming particles produced showers of secondary particles in the layers of heavy material. These showers passed through the layers of plastic scintillator, generating light which was taken by light guides (green) to the data collection electronics. The amount of light was proportional to the energy of the original particle. The inner 23 cm of lead and plastic sandwiches measured electrons and photons; the outer 80 cm of iron and plastic sandwiches measured strongly interacting hadrons. The detector was calibrated by injecting light through optical fibres or by placing a radioactive source in the tube on the bottom edge.

  13. Flooding in Central China

    Science.gov (United States)

    2002-01-01

    During the summer of 2002, frequent, heavy rains gave rise to floods and landslides throughout China that have killed over 1,000 people and affected millions. This false-color image of the western Yangtze River and Dongting Lake in central China was acquired on August 21, 2002, by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra spacecraft. (right) The latest flooding crisis in China centers on Dingtong Lake in the center of the image. Heavy rains have caused it to swell over its banks and swamp lakefront towns in the province of Hunan. As of August 23, 2002, more than 250,000 people have been evacuated, and over one million people have been brought in to fortify the dikes around the lake. Normally the lake would appear much smaller and more defined in the MODIS image. Credit: Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC.

  14. UA1 central detector

    CERN Multimedia

    The UA1 central detector was crucial to understanding the complex topology of proton-antiproton events. It played a most important role in identifying a handful of Ws and Zs among billions of collisions. The detector was a 6-chamber cylindrical assembly 5.8 m long and 2.3 m in diameter, the largest imaging drift chamber of its day. It recorded the tracks of charged particles curving in a 0.7 Tesla magnetic field, measuring their momentum, the sign of their electric charge and their rate of energy loss (dE/dx). Atoms in the argon-ethane gas mixture filling the chambers were ionised by the passage of charged particles. The electrons which were released drifted along an electric field shaped by field wires and were collected on sense wires. The geometrical arrangement of the 17000 field wires and 6125 sense wires allowed a spectacular 3-D interactive display of reconstructed physics events to be produced.

  15. Hope for Central China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The cities surrounding Changsha and Wuhan in the middle reaches of the Yangtze River will ally to form a new pilot zone to boost regional economic development China’s fourth pilot zone for compre- hensive and coordinated economic reform will soon debut in the middle reaches of the Yangtze River,open- ing a new area to attract foreign investment. The application has been submitted to the State Council for approval. The pilot zone will include two clusters of cities in central China:One consists of Wuhan,capital of Hubei Province,and eight surrounding cities in Hubei,and the other is composed of Changsha,Zhuzhou and Xiangtan,three major cities in Hunan Province.

  16. Sucker rod centralizer

    Energy Technology Data Exchange (ETDEWEB)

    Rivas, O.; Newski, A.

    1989-10-03

    This patent describes a device for centralizing at least one sucker rod within a production pipe downhole in a well and for reducing frictional forces between the pipe and at least one sucker rod. It comprises an elongate, substantially cylindrical body member having a longitudinal axis, a plurality of slots within the member and a rotatable member mounted within each slot, each of the plurality of slots has its major dimension along a first axis parallel to the longitudinal axis of the body member and is oriented with respect to the other seats so as to form a helicoidal array for maximizing the total surface contact area between the rotatable members and the pipe and for decreasing the forces acting on each rotatable member.

  17. Performance Improvement of QPSK Signal Predetection EGC Diversity Receiver

    Directory of Open Access Journals (Sweden)

    B. Nikolic

    2012-09-01

    Full Text Available This paper proposes a modification of quadrature phase-shift-keying (QPSK signal diversity reception with predetection equal gain combiner (EGC. The EGC combining is realized by using the constant modulus algorithm (CMA. Carrier synchronization is performed by the phase locked loop (PLL. Comparative analysis of the modified and ordinary diversity receiver in the presence of carrier frequency offset in the additive white Gaussian noise (AWGN channel, as well as in Rician fading channel is shown. The proposed diversity receiver allows significant frequency offset compared to the diversity receiver that uses only PLL, and the error probability of the proposed receiver is very close to the error probability of the receiver with only PLL and zero frequency offset. The functionality of the proposed diversity receiver, as well as its properties is experimentally verified on a system based on universal software radio peripheral (USRP hardware. The performed comparison confirms the expected behavior of the system.

  18. BPSK Receiver Based on Recursive Adaptive Filter with Remodulation

    Directory of Open Access Journals (Sweden)

    N. Milosevic

    2011-12-01

    Full Text Available This paper proposes a new binary phase shift keying (BPSK signal receiver intended for reception under conditions of significant carrier frequency offsets. The recursive adaptive filter with least mean squares (LMS adaptation is used. The proposed receiver has a constant, defining the balance between the recursive and the nonrecursive part of the filter, whose proper choice allows a simple construction of the receiver. The correct choice of this parameter could result in unitary length of the filter. The proposed receiver has performance very close to the performance of the BPSK receiver with perfect frequency synchronization, in a wide range of frequency offsets (plus/minus quarter of the signal bandwidth. The results obtained by the software simulation are confirmed by the experimental results measured on the receiver realized with the universal software radio peripheral (USRP, with the baseband signal processing at personal computer (PC.

  19. Interference-Detection Module in a Digital Radar Receiver

    Science.gov (United States)

    Fischman, Mark; Berkun, Andrew; Chu, Anhua; Freedman, Adam; Jourdan, Michael; McWatters, Dalia; Paller, Mimi

    2009-01-01

    A digital receiver in a 1.26-GHz spaceborne radar scatterometer now undergoing development includes a module for detecting radio-frequency interference (RFI) that could contaminate scientific data intended to be acquired by the scatterometer. The role of the RFI-detection module is to identify time intervals during which the received signal is likely to be contaminated by RFI and thereby to enable exclusion, from further scientific data processing, of signal data acquired during those intervals. The underlying concepts of detection of RFI and rejection of RFI-contaminated signal data are also potentially applicable in advanced terrestrial radio receivers, including software-defined radio receivers in general, receivers in cellular telephones and other wireless consumer electronic devices, and receivers in automotive collision-avoidance radar systems.

  20. Ways to rational management of accounts receivable at enterprises

    Directory of Open Access Journals (Sweden)

    Yevtushenko N. O.

    2015-05-01

    Full Text Available This article investigated the principal reasons of management problems an account receivable of enterprises. Credit politics of management is worked out by an account receivable of enterprises. Essence of the stages of construction of rational management an account receivable of enterprises is exposed. In the article are exposed the basic elements of control system for an account receivable such as mission, aims, strategy as politics of management. The basic stages of management politics are described for an account receivable of enterprises: analysis; organization of forming of principles of credit politics, terms of delivery of credit and procedure of collection of accounts receivable; planning of the use of modern forms of refunding, and similarly control.

  1. Signal-processing theory for the TurboRogue receiver

    Science.gov (United States)

    Thomas, J. B.

    1995-01-01

    Signal-processing theory for the TurboRogue receiver is presented. The signal form is traced from its formation at the GPS satellite, to the receiver antenna, and then through the various stages of the receiver, including extraction of phase and delay. The analysis treats the effects of ionosphere, troposphere, signal quantization, receiver components, and system noise, covering processing in both the 'code mode' when the P code is not encrypted and in the 'P-codeless mode' when the P code is encrypted. As a possible future improvement to the current analog front end, an example of a highly digital front end is analyzed.

  2. Coherent resonant Ka-band photonic microwave receiver

    CERN Document Server

    Ilchenko, Vladimir S; Savchenkov, Anatoliy A; Seidel, David; Matsko, Andrey B; Maleki, Lute

    2008-01-01

    We propose theoretically and demonstrate experimentally a coherent microwave photonic receiver operating at 35 GHz carrier frequency. The device is based on a lithium niobate or lithium tantalate optical whispering gallery mode resonator coupled to a microwave strip line resonator. Microwave local oscillator is fed into the microwave resonator along with the microwave signal. We show that the sensitivity of this receiver significantly exceeds the sensitivity of the incoherent quadratic receiver based on the same technology. The coherent receiver can possess a dynamic range in excess of 100 dB in 5 MHz band if a low noise laser is utilized.

  3. DVB-S2 inner receiver design for broadcasting mode

    Institute of Scientific and Technical Information of China (English)

    YANG Jian-xiao; WANG Kuang; ZOU Zhi-yong

    2007-01-01

    This paper details on the design of DVB-S2 receivers which is compliant with the broadcasting mode. Special attention is paid to the specific receiver functions necessary to demodulate the received signal. To show the system performance we consider the design of a complete receiver consisting of timing recovery unit, frame synchronization unit, frequency recovery unit and phase recovery unit. The system is easier to hardware implementation comparing with that provided in (ETSI, 2005; Sun et al.,2004). After the performance of the algorithms is analyzed and a quantitative result is given, this allows us to draw conclusions concerning the achievable system performance under realistic complexity assumptions.

  4. Frequency Estimator Performance for a Software-Based Beacon Receiver

    Science.gov (United States)

    Zemba, Michael J.; Morse, Jacquelynne Rose; Nessel, James A.; Miranda, Felix

    2014-01-01

    As propagation terminals have evolved, their design has trended more toward a software-based approach that facilitates convenient adjustment and customization of the receiver algorithms. One potential improvement is the implementation of a frequency estimation algorithm, through which the primary frequency component of the received signal can be estimated with a much greater resolution than with a simple peak search of the FFT spectrum. To select an estimator for usage in a QV-band beacon receiver, analysis of six frequency estimators was conducted to characterize their effectiveness as they relate to beacon receiver design.

  5. Reduction of convective losses in solar cavity receivers

    Science.gov (United States)

    Hughes, Graham; Pye, John; Kaufer, Martin; Abbasi-Shavazi, Ehsan; Zhang, Jack; McIntosh, Adam; Lindley, Tim

    2016-05-01

    Two design innovations are reported that can help improve the thermal performance of a solar cavity receiver. These innovations utilise the natural variation of wall temperature inside the cavity and active management of airflow in the vicinity of the receiver. The results of computational fluid dynamics modelling and laboratory-scale experiments suggest that the convective loss from a receiver can be reduced substantially by either mechanism. A further benefit is that both radiative and overall thermal losses from the cavity may be reduced. Further work to assess the performance of such receiver designs under operational conditions is discussed.

  6. Crustal structure beneath China from receiver function analysis

    Science.gov (United States)

    Chen, Youlin; Niu, Fenglin; Liu, Ruifeng; Huang, Zhibin; TkalčIć, Hrvoje; Sun, Li; Chan, Winston

    2010-03-01

    We collected and processed a large amount of high-quality broadband teleseismic waveform data recorded by the 48 Chinese National Digital Seismic Network stations to estimate large-scale lateral variations of crustal thickness and Vp/Vs ratio (hence Poisson's ratio) beneath China. A statistical method was used to select mutually coherent receiver functions at each station, which yielded over 200 traces for most of the stations. With the conventional H-κ (the crustal thickness and Vp/Vs ratio) approach, there is a large trade-off between H and κ. Consequently, multiple maxima are frequently observed in the H-κ domain. We introduced a weight function that measures the coherence between the P-to-S conversion and the reverberation phases at each H-κ grid to reduce the trade-off. A 4th-root stacking method was further applied to reduce uncorrelated noise relative to the linear stack. These modifications turned out to be very effective in reducing the H-κ trade-off and yielded reliable estimates of crustal thickness and Vp/Vs ratio. The crust beneath eastern China is as thin as 31-33 km and the underlying Moho is relatively flat and sharp. In the western part of China, the crust is considerably thicker and shows large variations. The Moho is observed at about 51 km depth along the Tian Shan fold system and about 84 km deep beneath the central part of the Tibetan Plateau. The transition occurs at the so-called N-S belt between about 100° and 110°E, which is featured by unusually high seismicity and large gravity anomalies. The average Vp/Vs ratio over the mainland China crust is about 1.730 (σ = 0.249), significantly lower than the global average 1.78 (σ = 0.27) of the continental crust. This lower Vp/Vs ratio may suggest a general absence of mafic lowermost crustal layer beneath China.

  7. Fast scanning heterodyne receiver for the measurement of the time evolution of the electron temperature profile on TFTR

    International Nuclear Information System (INIS)

    Two fast scanning heterodyne receivers, swept between 75 to 110 GHz and 110 to 170 GHz in 2 msec every 4 msec, were developed to measure the electron cyclotron emission on the horizontal midplane of the Tokamak Fusion Test Reactor (TFTR) plasma. An absolute, in situ calibration technique enables the determination of the profile of the plasma electron temperature from the cyclotron emission intensity. The 4 msec repetition rate of the receiver allowed the resolution of sawtooth fluctuations of temperature, whose period was 10 to 100 msec, in profiles with central temperatures of 1 to 2.5 keV

  8. Fast scanning heterodyne receiver for the measurement of the time evolution of the electron temperature profile on TFTR

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, G.; Efthimion, P.; McCarthy, M.; Arunasalam, V.; Bitzer, R.; Bryer, J.; Cutler, R.; Fredd, E.; Goldman, M.A.; Kaufman, D.

    1984-06-01

    Two fast scanning heterodyne receivers, swept between 75 to 110 GHz and 110 to 170 GHz in 2 msec every 4 msec, were developed to measure the electron cyclotron emission on the horizontal midplane of the Tokamak Fusion Test Reactor (TFTR) plasma. An absolute, in situ calibration technique enables the determination of the profile of the plasma electron temperature from the cyclotron emission intensity. The 4 msec repetition rate of the receiver allowed the resolution of sawtooth fluctuations of temperature, whose period was 10 to 100 msec, in profiles with central temperatures of 1 to 2.5 keV.

  9. Solar power generation by use of Stirling engine and heat loss analysis of its cavity receiver

    Science.gov (United States)

    Hussain, Tassawar

    Since concentrated power generation by Stirling engine has the highest efficiency therefore efficient power generation by concentrated systems using a Stirling engine was a primary motive of this research. A 1 kW Stirling engine was used to generate solar power using a Fresnel lens as a concentrator. Before operating On-Sun test, engine's performance test was conducted by combustion test. Propane gas with air was used to provide input heat to the Stirling Engine and 350W power was generated with 14% efficiency of the engine. Two kinds of receivers were used for On-Sun test, first type was the Inconel tubes with trapped helium gas and the second one was the heat pipe. Heat pipe with sodium as a working fluid is considered the best approach to transfer the uniform heat from the receiver to the helium gas in the heater head of the engine. A Number of On-Sun experiments were performed to generate the power. A minimum 1kW input power was required to generate power from the Stirling engine but it was concluded that the available Fresnel lens was not enough to provide sufficient input to the Stirling engine and hence engine was lagged to generate the solar power. Later on, for a high energy input a Beam Down system was also used to concentrate the solar light on the heater head of the Stirling engine. Beam down solar system in Masdar City UAE, constructed in 2009 is a variation of central receiver plant with cassegrainian optics. Around 1.5kW heat input was achieved from the Beam Down System and it was predicted that the engine receiver at beam down has the significant heat losses of about 900W. These high heat losses were the major hurdles to get the operating temperature (973K) of the heat pipes; hence power could not be generated even during the Beam Down test. Experiments were also performed to find the most suitable Cavity Receiver configuration for maximum solar radiation utilizations by engine receiver. Dimensionless parameter aperture ration (AR=d/D) and aperture

  10. Moments of Macrodiversity SC Receiver with Two Microdiversity EGC Receivers over Gamma Shadowed Rician Multipath Fading Channel

    Directory of Open Access Journals (Sweden)

    Ilija Temelkovski

    2015-08-01

    Full Text Available SC macrodiversity system with dual EGC microdiversity receivers operating over shadowed multipath fading environment is considered. Received signal experiences correlated Gamma long term fading and Rician short term fading. SC macrodiversity receiver reduces Gamma large scale fading effects, while EGC microdiversity receivers mitigate short term fading effects on system performance. Closed form expressions for arbitrary order output moments of macrodiversity structure output signal is evaluated. Numerical results, obtained for arbitrary order output moments are presented graphically to show Gamma long term fading severity effect, correlation coefficient effects and Rician factor effect.

  11. 14 CFR 221.162 - Receiver shall file adoption notices.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Receiver shall file adoption notices. 221... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS TARIFFS Adoption Publications Required To Show Change in Carrier's Name or Transfer of Operating Control § 221.162 Receiver shall file adoption notices. A...

  12. Enzymuria in neonates receiving continuous intravenous infusion of gentamicin

    DEFF Research Database (Denmark)

    Colding, H; Brygge, K; Brendstrup, L;

    1992-01-01

    with non-treatment periods in the same newborn infant (33 infants). The same tendency applied to AAP. Newborn infants receiving continuous intravenous infusion of gentamicin were not found to be at greater risk of nephrotoxicity than those receiving intermittent gentamicin treatment, using NAG and AAP...

  13. 42 CFR 435.120 - Individuals receiving SSI.

    Science.gov (United States)

    2010-10-01

    ... CFR 416.260 through 416.269 contain requirements governing determinations of eligibility under this... 42 Public Health 4 2010-10-01 2010-10-01 false Individuals receiving SSI. 435.120 Section 435.120..., Blind, and Disabled § 435.120 Individuals receiving SSI. Except as allowed under § 435.121, the...

  14. 48 CFR 1446.671 - Inspection, receiving and acceptance certification.

    Science.gov (United States)

    2010-10-01

    ... acceptance certification. 1446.671 Section 1446.671 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR CONTRACT MANAGEMENT QUALITY ASSURANCE Material Inspection and Receiving Reports § 1446.671 Inspection, receiving and acceptance certification. As prescribed in DIAR 1446.670, the...

  15. 48 CFR 1446.670 - Inspection, receiving and acceptance reports.

    Science.gov (United States)

    2010-10-01

    ... acceptance reports. 1446.670 Section 1446.670 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR CONTRACT MANAGEMENT QUALITY ASSURANCE Material Inspection and Receiving Reports 1446.670 Inspection, receiving and acceptance reports. (a) Except for simplified acquisitions (See FAR 46.404)...

  16. Distributed Iterative Processing for Interference Channels with Receiver Cooperation

    DEFF Research Database (Denmark)

    Badiu, Mihai Alin; Manchón, Carles Navarro; Bota, Vasile;

    2012-01-01

    We propose a method for the design and evaluation of distributed iterative algorithms for receiver cooperation in interference-limited wireless systems. Our approach views the processing within and collaboration between receivers as the solution to an inference problem in the probabilistic model...

  17. Transmit and Receive Diversity in Body-Centric Wireless Communications

    DEFF Research Database (Denmark)

    Medina, Pablo F.; Kvist, Søren Helstrup; Jakobsen, Kaj Bjarne;

    2012-01-01

    Two antenna diversity schemes are evaluated for use with the 2:45 GHz wireless o-body communication between a receiver worn at the ear and a stationary transmitter. A receive diversity scheme is compared to a transmit diversity scheme in an indoor environment. It is found that the two diversity...

  18. Compact wideband CMOS receiver frontends for wireless communication

    NARCIS (Netherlands)

    Blaakmeer, Stephan Carel

    2010-01-01

    There is an increasing demand for wideband receiver frontends. This is due to the emerge of wideband wireless standards (UWB) and due to the desire for flexible radios (SDR), which can comply with multiple existing and future communication standards. Existing receiver topologies are generally narro

  19. Qualification test for the flexible receiver. Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    Tedeschi, D.J.

    1994-12-12

    This document provides the test plan and procedures to certify and design verify the 42{double_prime} and 4{double_prime}-6{double_prime} Flexible Receiver as a safety class 3 system. The Flexible Receiver will be used by projects W-151 and W-320 for removing equipment from tanks C-106 and AZ-101.

  20. Numerical modeling of dish-Stirling reflux solar receivers

    Science.gov (United States)

    Hogan, R. E.

    Using reflux solar receivers to collect solar energy for dish-Stirling electric power generation systems is currently being investigated by several organizations, including Sandia National Laboratories, Albuquerque, New Mexico. In support of this program, Sandia has developed two numerical models describing the energy transfer within and thermal performance of pool-boiler and heat-pipe receivers. Both models are applicable to axisymmetric geometries and they both consider the radiative and convective energy transfer within the receiver cavity, the conductive and convective energy transfer within the receiver cavity, the conductive and convective energy transfer from the receiver housing, and the energy transfer to the receiver working fluid. In these models, the radiative transfer within the receiver is analyzed using a two-band (solar and infrared) net-radiation formulation for enclosure radiation. Empirical convective correlations describe the convective heat transfer from the cavity to the surroundings. The primary difference between the models is the level of detail in modeling the heat conduction through the receiver walls. The more detailed model uses a two-dimensional finite control volume method, whereas the simpler model uses a one-dimensional thermal resistance approach.

  1. Reimbursement of VAT on written-off Receivables

    DEFF Research Database (Denmark)

    Florentsen, Bjarne; Møller, Michael; Nielsen, Niels Chr.

    2003-01-01

    In many OECD countries, a seller has a right to reimbursement of VAT (RVAT) she has paid on goods sold, but for which she has not yet received payment. Such reimbursement of VAT on receivables is economically inefficient. It leads to:@* Distortion of credit markets, by subsidizing direct credit...

  2. 47 CFR 15.117 - TV broadcast receivers.

    Science.gov (United States)

    2010-10-01

    ... sound commensurate with their video and audio capabilities when receiving digital television signals. (i... receive over-the-air broadcasts with an antenna because of the Nation's transition to digital broadcasting... that provide for reception of digital television signals. The reference in this section to TV...

  3. 47 CFR 95.27 - Paging receiver description.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Paging receiver description. 95.27 Section 95.27 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES General Mobile Radio Service (GMRS) § 95.27 Paging receiver description. A...

  4. [Central auditory prosthesis].

    Science.gov (United States)

    Lenarz, T; Lim, H; Joseph, G; Reuter, G; Lenarz, M

    2009-06-01

    Deaf patients with severe sensory hearing loss can benefit from a cochlear implant (CI), which stimulates the auditory nerve fibers. However, patients who do not have an intact auditory nerve cannot benefit from a CI. The majority of these patients are neurofibromatosis type 2 (NF2) patients who developed neural deafness due to growth or surgical removal of a bilateral acoustic neuroma. The only current solution is the auditory brainstem implant (ABI), which stimulates the surface of the cochlear nucleus in the brainstem. Although the ABI provides improvement in environmental awareness and lip-reading capabilities, only a few NF2 patients have achieved some limited open set speech perception. In the search for alternative procedures our research group in collaboration with Cochlear Ltd. (Australia) developed a human prototype auditory midbrain implant (AMI), which is designed to electrically stimulate the inferior colliculus (IC). The IC has the potential as a new target for an auditory prosthesis as it provides access to neural projections necessary for speech perception as well as a systematic map of spectral information. In this paper the present status of research and development in the field of central auditory prostheses is presented with respect to technology, surgical technique and hearing results as well as the background concepts of ABI and AMI. PMID:19517084

  5. Evaluation and Error Analysis for a Solar thermal Receiver

    Energy Technology Data Exchange (ETDEWEB)

    Pfander, M.

    2001-07-01

    In the following study a complete balance over the REFOS receiver module, mounted on the tower power plant CESA-1 at the Plataforma Solar de Almeria (PSA), is carried out. Additionally an error inspection of the various measurement techniques used in the REFOS project is made. Especially the flux measurement system Prohermes that is used to determine the total entry power of the receiver module and known as a major error source is analysed in detail. Simulations and experiments on the particular instruments are used to determine and quantify possible error sources. After discovering the origin of the errors they are reduced and included in the error calculation. the ultimate result is presented as an overall efficiency of the receiver module in dependence on the flux density at the receiver module's entry plane and the receiver operating temperature. (Author) 26 refs.

  6. Joint Transmitter-Receiver Optimization in the Downlink CDMA Systems

    Directory of Open Access Journals (Sweden)

    Mohammad Saquib

    2002-08-01

    Full Text Available To maximize the downlink code-division multiple access (CDMA system capacity, we propose to minimize the total transmitted power of the system subject to users′ signal-to-interference ratio (SIR requirements via designing optimum transmitter sequences and utilizing linear optimum receivers (minimum mean square error (MMSE receiver. In our work on joint transmitter-receiver design for the downlink CDMA systems with multiple antennas and multipath channels, we develop several optimization algorithms by considering various system constraints and prove their convergence. We empirically observed that under the optimization algorithm with no constraint on the system, the optimum receiver structure matches the received transmitter sequences. A simulation study is performed to see how the different practical system constraints penalize the system with respect to the optimum algorithm with no constraint on the system.

  7. Monobit Digital Receivers for QPSK: Design, Analysis and Performance

    CERN Document Server

    Wang, Zhiyong; Zhang, Wenyi; Wei, Guo

    2012-01-01

    Future communication system requires large bandwidth to achieve high data rate up to multigigabit/ sec, which makes analog-to-digital (ADC) become a key bottleneck for the implementation of digital receivers due to its high complexity and large power consumption. Therefore, monobit receivers for BPSK have been proposed to address this problem. In this work, QPSK modulation is considered for higher data rate. First, the optimal receiver based on monobit ADC with Nyquist sampling is derived, and its corresponding performance in the form of deflection ratio is calculated. Then a suboptimal but more practical monobit receiver is obtained, along with iterative demodulation and small sample removal. The effect of the imbalances between the In-phase (I) and Quadrature-phase (Q) branches, including the amplitude and phase imbalances, is carefully investigated too. To combat the performance loss caused by IQ imbalances, monobit receivers based on double training sequences are proposed. Numerical simulations show that ...

  8. Gain Stabilization of a Submillimeter SIS Heterodyne Receiver

    CERN Document Server

    Battat, James; Hunter, Todd R; Kimberk, Robert; Leiker, Patrick S; Tong, Cheuk-yu Edward

    2007-01-01

    We have designed a system to stabilize the gain of a submillimeter heterodyne receiver against thermal fluctuations of the mixing element. In the most sensitive heterodyne receivers, the mixer is usually cooled to 4 K using a closed-cycle cryocooler, which can introduce ~1% fluctuations in the physical temperature of the receiver components. We compensate for the resulting mixer conversion gain fluctuations by monitoring the physical temperature of the mixer and adjusting the gain of the intermediate frequency (IF) amplifier that immediately follows the mixer. This IF power stabilization scheme, developed for use at the Submillimeter Array (SMA), a submillimeter interferometer telescope on Mauna Kea in Hawaii, routinely achieves a receiver gain stability of 1 part in 6,000 (rms to mean). This is an order of magnitude improvement over the typical uncorrected stability of 1 part in a few hundred. Our gain stabilization scheme is a useful addition to SIS heterodyne receivers that are cooled using closed-cycle cr...

  9. Evaluation and Error Analysis for a Solar Thermal Receiver

    International Nuclear Information System (INIS)

    In the following study a complete balance over the REFOS receiver module, mounted on the tower power plant CESA-1 at the Plataforma Solar de Almeria (PSA), is carried out. Additionally an error inspection of the various measurement techniques used in the REFOS project is made. Especially the flux measurement system Pro hermes that is used to determine the total entry power of the receiver module and known as a major error source is analysed in detail. Simulations and experiments on the particular instruments are used to determine and quantify possible error sources. After discovering the origin of the errors they are reduced and included in the error calculation. The ultimate result is presented as an overall efficiency of the receiver module in dependence on the flux density at the receiver modules entry plane and the receiver operating temperature. (Author) 26 refs

  10. Sensible heat receiver for solar dynamic space power system

    Science.gov (United States)

    Perez-Davis, Marla E.; Gaier, James R.; Petrefski, Chris

    1991-01-01

    A sensible heat receiver is considered which uses a vapor grown carbon fiber-carbon (VGCF/C) composite as the thermal storage medium and which was designed for a 7-kW Brayton engine. This heat receiver stores the required energy to power the system during eclipse in the VGCF/C composite. The heat receiver thermal analysis was conducted through the Systems Improved Numerical Differencing Analyzer and Fluid Integrator (SINDA) software package. The sensible heat receiver compares well with other latent and advanced sensible heat receivers analyzed in other studies, while avoiding the problems associated with latent heat storage salts and liquid metal heat pipes. The concept also satisfies the design requirements for a 7-kW Brayton engine system. The weight and size of the system can be optimized by changes in geometry and technology advances for this new material.

  11. Ultrabroadband phased-array radio frequency (RF) receivers based on optical techniques

    Science.gov (United States)

    Overmiller, Brock M.; Schuetz, Christopher A.; Schneider, Garrett; Murakowski, Janusz; Prather, Dennis W.

    2014-03-01

    Military operations require the ability to locate and identify electronic emissions in the battlefield environment. However, recent developments in radio detection and ranging (RADAR) and communications technology are making it harder to effectively identify such emissions. Phased array systems aid in discriminating emitters in the scene by virtue of their relatively high-gain beam steering and nulling capabilities. For the purpose of locating emitters, we present an approach realize a broadband receiver based on optical processing techniques applied to the response of detectors in conformal antenna arrays. This approach utilizes photonic techniques that enable us to capture, route, and process the incoming signals. Optical modulators convert the incoming signals up to and exceeding 110 GHz with appreciable conversion efficiency and route these signals via fiber optics to a central processing location. This central processor consists of a closed loop phase control system which compensates for phase fluctuations induced on the fibers due to thermal or acoustic vibrations as well as an optical heterodyne approach for signal conversion down to baseband. Our optical heterodyne approach uses injection-locked paired optical sources to perform heterodyne downconversion/frequency identification of the detected emission. Preliminary geolocation and frequency identification testing of electronic emissions has been performed demonstrating the capabilities of our RF receiver.

  12. Study of Ionospheric Perturbations in D-Layer Using VLF Receiver at Tashkent IHY Station

    Science.gov (United States)

    Ahmedov, Bobomurat

    2016-07-01

    Tashkent International Heliophysical Year (IHY) station is a member of Atmospheric Weather Electromagnetic System for Observation, Modeling and Education (AWESOME) network being operated globally to study the ionosphere and the magnetosphere with the help of electromagnetic waves in Very Low Frequency (VLF) band. Regular monitoring of the D- and F-layers of ionosphere over Central Asia territory is being performed on the permanent basis starting year 2008 when one VLF receiver and two SuperSID receivers were provided to Uzbekistan IHY cite by Stanford University. The results obtained at Tashkent IHY station are applied to earthquake electromagnetic precursors, lightning, and Solar flares and to ionospheric disturbances originating from gamma ray flares of Soft Gamma-Ray Repeaters connected with evolution of strongly magnetized neutron stars believed as magnetars. Regular monitoring of the D-layer of ionosphere over Central Asia territory has been performed on the permanent basis. Several Solar events are observed and the analysis has shown that there is simultaneous correlation between the times of change of amplitude of the waves and the Solar flares. Features of the lightning discharge generated by radio atmospherics are studied and its effectiveness in D-region ionosphere diagnostics is examined.

  13. Methodology for generation of heliostat field layout in central receiver systems based on yearly normalized energy surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, Marcelino; Romero, Manuel [DER-Plataforma Solar de Almeria, CIEMAT, Avda. Complutense 22, E-28040 Madrid (Spain)

    2006-07-15

    The heliostat field layout is an essential task for any solar tower plant optimization process. Radially staggered and other distributions are usually optimised by computer codes using different approaches. In most of those cases, due to the CPU time required, the heliostat field layout is optimised by several mathematical models and simplifications. With today's computers, it is possible to calculate the yearly energy available at any point in a site for a given tower height, the yearly normalized energy surface (YNES). Yearly efficiency maps can be generated based on the cosine factor, the spillage factor and the atmospheric attenuation coefficient of the site using real Direct Normal Irradiance (DNI) data, within a reasonable computing time. It is therefore easy to find the place where the yearly energy available is the highest for location of the first heliostat. It is also possible to calculate the effect of shadowing and blocking by this heliostat on the YNES, so YNES can be re-calculated and the best position for the next heliostat can be found. Although this iterative method is time-consuming, it is worthwhile if either the efficiency of the solar plant can be increased or the capital cost reduced. This YNES-based layout generation method enables better flexibility than pre-determined gridding strategies such as used in DELSOL. The paper includes a description of the optimization procedure. (author)

  14. 10-MWe solar-thermal central-receiver pilot plant: collector subsystem foundation construction. Revision No. 1

    Energy Technology Data Exchange (ETDEWEB)

    1979-12-18

    Bid documents are provided for the construction of the collector subsystem foundation of the Barstow Solar Pilot Plant, including invitation to bid, bid form, representations and certifications, construction contract, and labor standards provisions of the Davis-Bacon Act. Instructions to bidders, general provisions and general conditions are included. Technical specifications are provided for the construction. (LEW)

  15. Structural analysis of a reflux pool-boiler solar receiver

    Science.gov (United States)

    Hoffman, E. L.; Stone, C. M.

    1991-06-01

    Coupled thermal-structural finite element calculations of a reflux pool-boiler solar receiver were performed to characterize the operating stresses and to address issues affecting the service life of the receiver. Analyses performed using shell elements provided information for receiver material selection and design optimization. Calculations based on linear elastic fracture mechanics principles were performed using continuum elements to assess the vulnerability of a seam-weld to fatigue crack growth. All calculations were performed using ABAQUS, a general purpose finite element code, and elements specifically formulated for coupled thermal-structural analysis. Two materials were evaluated: 316L SS and Haynes 230 alloys. The receiver response was simulated for a combination of structural and thermal loads that represent the startup and operating conditions of the receiver. For both materials, maximum stresses in the receiver developed shortly after startup due to uneven temperature distribution across the receiver surface. The largest effective stress was near yield in the 316L SS receiver and below 39 percent of yield in the Haynes 230 receiver. The calculations demonstrated that stress reductions of over 25 percent could be obtained by reducing the aft dome thickness to one closer to the absorber. The fatigue calculations demonstrated that the stress distribution near the seam-weld notch depends primarily on the structural load created by internal pressurization of the receiver rather than the thermal, indicating that the thermal loads can be neglected when assessing the stress intensity near the seam-weld notch. The stress intensity factor, computed using the J-integral method and crack opening-displacement field equations, was significantly below the fatigue threshold for most steels. The calculations indicated that the weld notch was always loaded in compression, a condition which is not conducive to fatigue crack growth.

  16. A dynamical systems view of network centrality.

    Science.gov (United States)

    Grindrod, Peter; Higham, Desmond J

    2014-05-01

    To gain insights about dynamic networks, the dominant paradigm is to study discrete snapshots, or timeslices, as the interactions evolve. Here, we develop and test a new mathematical framework where network evolution is handled over continuous time, giving an elegant dynamical systems representation for the important concept of node centrality. The resulting system allows us to track the relative influence of each individual. This new setting is natural in many digital applications, offering both conceptual and computational advantages. The novel differential equations approach is convenient for modelling and analysis of network evolution and gives rise to an interesting application of the matrix logarithm function. From a computational perspective, it avoids the awkward up-front compromises between accuracy, efficiency and redundancy required in the prevalent discrete-time setting. Instead, we can rely on state-of-the-art ODE software, where discretization takes place adaptively in response to the prevailing system dynamics. The new centrality system generalizes the widely used Katz measure, and allows us to identify and track, at any resolution, the most influential nodes in terms of broadcasting and receiving information through time-dependent links. In addition to the classical static network notion of attenuation across edges, the new ODE also allows for attenuation over time, as information becomes stale. This allows 'running measures' to be computed, so that networks can be monitored in real time over arbitrarily long intervals. With regard to computational efficiency, we explain why it is cheaper to track good receivers of information than good broadcasters. An important consequence is that the overall broadcast activity in the network can also be monitored efficiently. We use two synthetic examples to validate the relevance of the new measures. We then illustrate the ideas on a large-scale voice call network, where key features are discovered that are not

  17. Analysis on natural gas geo-politics in Central Asia-Russia region

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Dan

    2010-09-15

    In the year of 2009, some events happened in Central Asia-Russia Region. The transit countries of Nabucco pipeline signed the agreement and the project received considerable progress. The China-Turkmenistan pipeline achieved the completion of ventilation. All these could be landmarks in Central Asia-Russia's geo-political situation. Diversification strategy of gas imports in Europe and diversification strategy of export in Central Asia have been effectively promoted, and the relationship between China and Central Asia becomes closer. Now, the new supply pattern of the region is coming into being and the nature gas geo-political situation in the region is undergoing profound changes.

  18. Central pontine myelinolysis.

    Science.gov (United States)

    Kiley, M A; King, M; Burns, R J

    1999-03-01

    Central pontine myelinolysis (CPM) was initially associated with alcoholism. Subsequently other factors, including rapid reversal of hyponatraemia and extreme serum hypoosmolality associated with severe burns, have been identified as other important factors in its pathogenesis. Extra-pontine lesions have also been described. CPM may be found at autopsy, either having been overlooked during life or as an incidental finding. Its precise incidence is not known but the ability to diagnose it during life has been helped by modern neuroimaging, particularly magnetic resonance imaging (MRI) of the brain stem. In the past the prognosis for CPM was thought to be invariably fatal. It is clear now that with the greater general awareness of the disorder and the ability to diagnose it during life that some degree of recovery is possible. However, the number who do recover and the degree of recovery is not known. We report a 40-year-old man who developed CPM presenting with quadriparesis and inability to speak and swallow. There were risk factors for CPM and the diagnosis was confirmed by MRI scanning. He made a complete recovery although he remains ataxic. We are reporting this case as we believe it is important to make clinicians aware of the potential for recovery of CPM. While no specific treatment has been shown to influence the degree and rate of recovery of the demyelination, the fact that the quadriplegia and bulbar paralysis can recover fully is of considerable importance. In particular, it means that when the diagnosis is made, complete and vigorous nursing and medical care is warranted. PMID:18639140

  19. Central nervous system tumors

    International Nuclear Information System (INIS)

    Central nervous system (CNS) tumors are relatively common in veterinary medicine, with most diagnoses occurring in the canine and feline species. Numerous tumor types from various cells or origins have been identified with the most common tumors being meningiomas and glial cell tumors. Radiation therapy is often used as an aid to control the clinical signs associated with these neoplasms. In general, these tumors have a very low metastatic potential, such that local control offers substantial benefit. Experience in veterinary radiation oncology would indicate that many patients benefit from radiation treatment. Current practice indicates the need for computed tomography or magnetic resonance imaging studies. These highly beneficial studies are used for diagnosis, treatment planning, and to monitor treatment response. Improvements in treatment planning and radiation delivered to the tumor, while sparing the normal tissues, should improve local control and decrease potential radiation related problems to the CNS. When possible, multiple fractions of 3 Gy or less should be used. The tolerance dose to the normal tissue with this fractionation schedule is 50 to 55 Gy. The most common and serious complications of radiation for CNS tumors is delayed radiation myelopathy and necrosis. Medical management of the patient during radiation therapy requires careful attention to anesthetic protocols, and medications to reduce intracranial pressure that is often elevated in these patients. Canine brain tumors have served as an experimental model to test numerous new treatments. Increased availability of advanced imaging modalities has spawned increased detection of these neoplasms. Early detection of these tumors with appropriate aggressive therapy should prove beneficial to many patients

  20. Dublin South Central (DSC)

    LENUS (Irish Health Repository)

    O'Gorman, Clodagh S M

    2010-12-01

    Children who appear healthy, even if they have one or more recognized cardiovascular risk factors, do not generally have outcomes of cardiovascular or other vascular disease during childhood. Historically, pediatric medicine has not aggressively screened for or treated cardiovascular risk factors in otherwise healthy children. However, studies such as the P-Day Study (Pathobiological Determinants of Atherosclerosis in Youth), and the Bogalusa Heart Study, indicate that healthy children at remarkably young ages can have evidence of significant atherosclerosis. With the increasing prevalence of pediatric obesity, can we expect more health problems related to the consequences of pediatric dyslipidemia, hypertriglyceridemia, and atherosclerosis in the future? For many years, medications have been available and used in adult populations to treat dyslipidemia. In recent years, reports of short-term safety of some of these medications in children have been published. However, none of these studies have detailed long-term follow-up, and therefore none have described potential late side-effects of early cholesterol-lowering therapy, or potential benefits in terms of reduction of or delay in cardiovascular or other vascular end-points. In 2007, the American Heart Association published a scientific statement on the use of cholesterol-lowering therapy in pediatric patients. In this review paper, we discuss some of the current literature on cholesterol-lowering therapy in children, including the statins that are currently available for use in children, and some of the cautions with using these and other cholesterol-lowering medications. A central tenet of this review is that medications are not a substitute for dietary and lifestyle interventions, and that even in children on cholesterol-lowering medications, physicians should take every opportunity to encourage children and their parents to make healthy diet and lifestyle choices.

  1. y Banca Central

    Directory of Open Access Journals (Sweden)

    Ángel García Banchs

    2008-01-01

    Full Text Available Las teorías monetarias modernas, ortodoxas y heterodoxas, han pasado por alto el hecho de que posterior a la Segunda Guerra Mundial el mundo quedó dividido entre economías emisoras y receptoras de reservas, pasando el sistema monetario internacional desde entonces a ser completamente asimétrico. De allí que, desde el punto de vista teórico, señalemos la necesidad de tomar en cuenta si las economías emiten o no una moneda de reserva internacional, pues ello explicaría la existencia de diversas prácticas monetarias a nivel mundial. Este trabajo propone, y calcula, indicadores basados en datos provenientes de los balances de activos y pasivos de quince bancos centrales pertenecientes a Norteamérica, Suramérica, Europa y Asia. Los hallazgos con respecto a las diversas estructuras de activos y pasivos confirman la hipótesis acerca de la presencia de tales asimetrías. Se infiere en consecuencia que la política monetaria es menos flexible pero más influyente en las economías receptoras de reservas, y a la vez más flexible pero menos influyente en las economías emisoras. En pocas palabras, la exogeneidad de la tasa de interés de corto plazo es más débil en el caso de las economías receptoras de reservas las cuales se ven obligadas a acumular divisas y a procurar la estabilidad del tipo de cambio, debido a que sus monedas locales no son aceptadas en el exterior. Así, aunque la oferta crediticia es endógena en esas economías, las mismas no han sido capaces de librarse aún de la necesidad de mantener reservas monetarias en divisas extranjeras

  2. Commissioning of the ATLAS Level-1 Central Trigger

    CERN Document Server

    Berge, D; Ellis, N; Farthouat, P; Fischer, G; Haas, S; Haller, J; Maettig, S; Messina, A; Pauly, T; Sherman, D; Spiwoks, R

    2010-01-01

    The ATLAS Level-1 Central Trigger (L1CT) consists of the Central Trigger Processor (CTP) and the Muon to Central Trigger Processor Interface (MUCTPI). The CTP forms the final Level-1 Accept (L1A) decision based on the information received from the Level-1 Calorimeter Trigger system and from the muon trigger system through the MUCTPI. Additional inputs are provided for the forward detectors, the filled-bunch trigger, and the minimum-bias trigger scintillators. The CTP also receives timing signals from the Large Hadron Collider (LHC) machine. It fans out the L1A together with timing and control signals to the Local Trigger Processor (LTP) of the subdetectors. Via the same connections it receives the Busy signal to throttle the Level-1 generation. Upon generation of L1A the L1CT sends trigger summary information to the DAQ and Region-of-Interest to the Level-2 Trigger system. In this contribution we present an overview of the final L1CT trigger system as it is now installed in the ATLAS experiment and we describ...

  3. Analysis of signal acquisition in GPS receiver software

    Directory of Open Access Journals (Sweden)

    Vlada S. Sokolović

    2011-01-01

    Full Text Available This paper presents a critical analysis of the flow signal processing carried out in GPS receiver software, which served as a basis for a critical comparison of different signal processing architectures within the GPS receiver. It is possible to achieve Increased flexibility and reduction of GPS device commercial costs, including those of mobile devices, by using radio technology software (SDR, Software Defined Radio. The SDR application can be realized when certain hardware components in a GPS receiver are replaced. Signal processing in the SDR is implemented using a programmable DSP (Digital Signal Processing or FPGA (Field Programmable Gate Array circuit, which allows a simple change of digital signal processing algorithms and a simple change of the receiver parameters. The starting point of the research is the signal generated on the satellite the structure of which is shown in the paper. Based on the GPS signal structure, a receiver is realized with a task to extract an appropriate signal from the spectrum and detect it. Based on collected navigation data, the receiver calculates the position of the end user. The signal coming from the satellite may be at the carrier frequencies of L1 and L2. Since the SPS is used in the civil service, all the tests shown in the work were performed on the L1 signal. The signal coming to the receiver is generated in the spread spectrum technology and is situated below the level of noise. Such signals often interfere with signals from the environment which presents a difficulty for a receiver to perform proper detection and signal processing. Therefore, signal processing technology is continually being improved, aiming at more accurate and faster signal processing. All tests were carried out on a signal acquired from the satellite using the SE4110 input circuit used for filtering, amplification and signal selection. The samples of the received signal were forwarded to a computer for data post processing, i. e

  4. A Novel Receiver Architecture for DBF Antenna Array

    Institute of Scientific and Technical Information of China (English)

    ZHENG Sheng-hua; XU Da-zhuan; JIN Xue-ming

    2007-01-01

    The developments of the high speed analog to digital converters (ADC) and advanced digital signal processors (DSP) make the smart antenna with digital beamforming (DBF)a reality. In conventional M-elements array antenna system, each element has its own receiving channel and ADCs. In this paper, a novel smart antenna receiver with digital beamforming is proposed. The essential idea is to realize the digital beamforming receiver based on bandpass sampling of multiple distinct intermediate frequency (IF) signals. The proposed system reduces receiver hardware from M IF channels and 2M ADCs to one IF channel and one ADC using a heterodyne radio frequency (RF) circuitry and a multiple bandpass sampling digital receiver. In this scheme, the sampling rate of the ADC is much higher than the summation of the M times of the signal bandwidth. The local oscillator produces different local frequency for each RF channel.The receiver architecture is presented in detail, and the simulation of bandpass sampling of multiple signals and digital down conversion to baseband is given. The principle analysis and simulation results indicate the effectiveness of the new proposed receiver.

  5. Analysis and simulation of an integrated optical receiver

    Science.gov (United States)

    Elnaggar, Maha Saad

    2001-07-01

    Low latency, high bandwidth interconnection networks that directly link arbitrary pairs of processing elements without contention are desirable for parallel computers. The S_imultaneous O_ptical M_ultiprocessor E_xchange B_us based (SOME-Bus) on a fiber optic interconnect is such a network [21]. In the SOME-Bus, each processor can receive data simultaneously from all other processors in the system using an array of receiver. The receiver array is conceived as a single VLSI chip which has regular electrical connections to the processor and which takes input from all of the other processors through the optical fibers that lie on top of the die. This digital receiver should be integrated with the analog conditioning circuit which will accept the output from the photodetector and provide good digital signals to the receiver element [29]. The integration of the digital receiver element and the analog conditioning circuit in one chip reduces the layout area of the design and the cost. However, this integration gives rise to substrate noise problems. This noise is caused mainly by two factors: capacitive coupling and ground bounce. The ability to construct such a receiver with the lowest possible noise is a key to the success of the SOME-Bus system. In this dissertation, rapid modeling using HSPICE for substrate effect, capacitive coupling noise, and guard ring, as a solution for capacitive coupling noise, are presented. Also, a power based model is used to model the ground bounce noise problem. These models help in the early stages of the design to ascertain the system feasibility. Simulation results for these models indicate that the different sources of digital noise could be kept under control and do not significantly degrade the performance of the receiver element. Therefore, it is found that the designed receiver could be successfully fabricated.

  6. High temperature helical tubular receiver for concentrating solar power system

    Science.gov (United States)

    Hossain, Nazmul

    In the field of conventional cleaner power generation technology, concentrating solar power systems have introduced remarkable opportunity. In a solar power tower, solar energy concentrated by the heliostats at a single point produces very high temperature. Falling solid particles or heat transfer fluid passing through that high temperature region absorbs heat to generate electricity. Increasing the residence time will result in more heat gain and increase efficiency. A novel design of solar receiver for both fluid and solid particle is approached in this paper which can increase residence time resulting in higher temperature gain in one cycle compared to conventional receivers. The helical tubular solar receiver placed at the focused sunlight region meets the higher outlet temperature and efficiency. A vertical tubular receiver is modeled and analyzed for single phase flow with molten salt as heat transfer fluid and alloy625 as heat transfer material. The result is compared to a journal paper of similar numerical and experimental setup for validating our modeling. New types of helical tubular solar receivers are modeled and analyzed with heat transfer fluid turbulent flow in single phase, and granular particle and air plug flow in multiphase to observe the temperature rise in one cyclic operation. The Discrete Ordinate radiation model is used for numerical analysis with simulation software Ansys Fluent 15.0. The Eulerian granular multiphase model is used for multiphase flow. Applying the same modeling parameters and boundary conditions, the results of vertical and helical receivers are compared. With a helical receiver, higher temperature gain of heat transfer fluid is achieved in one cycle for both single phase and multiphase flow compared to the vertical receiver. Performance is also observed by varying dimension of helical receiver.

  7. Central bank independence and ageing

    OpenAIRE

    Farvaque, Etienne; Héricourt, Jérôme; Lagadec, Gaël

    2008-01-01

    We contrast the influence of demography and central bank independence on inflation. The recent demographic trends in developed countries are shown to weight more on inflation than central bank independence, while the contrary stands for the period from 1960 to 1979.

  8. Design and Implementation of a Cueing Wideband Digital EW Receiver

    Institute of Scientific and Technical Information of China (English)

    ZHU Jun; TANG Bin; WU Wei; JIANG Zong-ming; ZHANG Chang-ju; YIN Mao-wei; DEN Ming-yi; DU Dong-ping

    2006-01-01

    A cueing wideband digital Electronic Warfare (EW) receiver is presented. The proposed receiver, which is to measure the instantaneous frequency and bandwidth of the intercept short-duration pulse radar signals that cue and match the corresponding ones, meets the requirements of good sensitivity and dynamic range for EW and can save hardware resources greatly as well. In addition, real-time signal processing, which is the main bottleneck for covering a wide instantaneous frequency band for EW receiver, is better solved in the proposed design structure. The highly efficient implementation and good parameter estimation algorithms are proposed as well. Theoretical analysis and experimental results show that this structure is feasible.

  9. A Brayton cycle solar dynamic heat receiver for space

    Science.gov (United States)

    Sedgwick, L. M.; Nordwall, H. L.; Kaufmann, K. J.; Johnson, S. D.

    1989-01-01

    The detailed design of a heat receiver developed to meet the requirements of the Space Station Freedom, which will be assembled and operated in low earth orbit beginning in the mid-1990's, is described. The heat receiver supplies thermal energy to a nominal 25-kW closed-Brayton-cycle power conversion unit. The receiver employs an integral thermal energy storage system utilizing the latent heat of a eutectic-salt phase-change mixture to store energy for eclipse operation. The salt is contained within a felt metal matrix which enhances heat transfer and controls the salt void distribution during solidification.

  10. Solar dynamic heat receiver thermal characteristics in low earth orbit

    Science.gov (United States)

    Wu, Y. C.; Roschke, E. J.; Birur, G. C.

    1988-01-01

    A simplified system model is under development for evaluating the thermal characteristics and thermal performance of a solar dynamic spacecraft energy system's heat receiver. Results based on baseline orbit, power system configuration, and operational conditions, are generated for three basic receiver concepts and three concentrator surface slope errors. Receiver thermal characteristics and thermal behavior in LEO conditions are presented. The configuration in which heat is directly transferred to the working fluid is noted to generate the best system and thermal characteristics. as well as the lowest performance degradation with increasing slope error.

  11. Behavior of Gift Receiving Consumers During the Decision Making Process

    Directory of Open Access Journals (Sweden)

    Jorge Aníbal Cruz Cárdenas

    2010-12-01

    Full Text Available The behavior of gift receiving consumers has been little studied. In the present study, in-depth interviews were conducted with 24 young university students, sourcing 153 of gifting events in which the participants were recipients. Four forms of action arose from the receiver during the gift buying process: work with the giver, manipulate the giver, unintentionally influence and not influence in any way. These aforementioned action patterns lead to varying degrees of involvement, were generally of low aggression, and linked with the lower power of the receiver when compared to the giver and with cultural factors.

  12. Performance gain of displacement receiver with optimized prior probability

    International Nuclear Information System (INIS)

    We numerically study the performance of the displacement based quantum receiver for the discrimination of weak 3- and 4-phase-shift keyed (PSK) coherent state signals. We show that due to the nontrivial asymmetry of the receiver structure, optimization of the prior probability increases the mutual information and achieves sub-shot-noise limit discrimination. Moreover, we estimate the cutoff rate for a 4-PSK signal and confirm that the prior probability optimization shortens the code length for a given decoding error criterion. Such consideration for the asymmetric channel matrix is essential in a study of the compassable quantum receiver.

  13. Design of BPS digital frontend for software defined radio receiver

    Institute of Scientific and Technical Information of China (English)

    王洪梅; KIM Jae-hyung; 王法广; LEE Sang-hyuk; 王雪松

    2015-01-01

    In radio receivers, complete implementation of the software defined radio (SDR) concept is mainly limited by frontend. Based on bandpass sampling (BPS) theory, a flexible digital frontend (DFE) platform for SDR receiver is designed. In order to increase the processing speed, Gigabit Ethernet was applied in the platform at speed of 5×108 bit/s. By appropriate design of interpolant according to the position of input RF signals, multi-band receiving can be realized in the platform with suppression more than 35 dB without changing hardware.

  14. Central mechanisms II: pharmacology of brainstem pathways.

    Science.gov (United States)

    Bolser, D C

    2009-01-01

    Following systemic administration, centrally acting antitussive drugs are generally assumed to act in the brainstem to inhibit cough. However, recent work in humans has raised the possibility of suprapontine sites of action for cough suppressants. For drugs that may act in the brainstem, the specific locations, types of neurones affected, and receptor specificities of the compounds represent important issues regarding their cough-suppressant actions. Two medullary areas that have received the most attention regarding the actions of antitussive drugs are the nucleus of the tractus solitarius (NTS) and the caudal ventrolateral respiratory column. Studies that have implicated these two medullary areas have employed both microinjection and in vitro recording methods to control the location of action of the antitussive drugs. Other brainstem regions contain neurones that participate in the production of cough and could represent potential sites of action of antitussive drugs. These regions include the raphe nuclei, pontine nuclei, and rostral ventrolateral medulla. Specific receptor subtypes have been associated with the suppression of cough at central sites, including 5-HT1A, opioid (mu, kappa, and delta), GABA-B, tachykinin neurokinin-1 (NK-1) and neurokinin-2, non-opioid (NOP-1), cannabinoid, dopaminergic, and sigma receptors. Aside from tachykinin NK-1 receptors in the NTS, relatively little is known regarding the receptor specificity of putative antitussive drugs in particular brainstem regions. Our understanding of the mechanisms of action of antitussive drugs would be significantly advanced by further work in this area. PMID:18825342

  15. North Central Project: Environment act proposal

    International Nuclear Information System (INIS)

    Manitoba Hydro proposes to construct a power transmission and distribution line system to connect 12 northern Manitoba communities to the utility's central power grid. The purpose of this North Central Project (NCP) is to provide reliable and unrestricted electric service to remote communities now largely receiving limited diesel-generated power. The NCP is composed of a 138-kV transmission line running ca 350 km from the Kelsey Generating Station, ca 160 km of 25-kV distribution lines, new transformer stations at four communities, upgraded internal distribution systems within the communities, removal of existing diesel stations and restoration of the sites, modifications and additions to the Kelsey switchyard, and a communications system. The NCP is described in detail, including proposed line routes and transformer station locations, rationales for site and route selection, projected impacts on the environment and local societies, and consultations with the communities to be affected. Potential impacts are expected to be modest, with few unmitigable adverse impacts and a number of potentially significant positive benefits. Impact management measures are proposed to prevent or mitigate adverse effects and to create or enhance positive impacts such as local employment of native peoples. 49 figs., 1 tab

  16. SQUARE AND RHOMBUS CENTRAL CONFIGURATIONS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper, we consider the flat central configurations of bodies using the characteristic set method. We completely solve two special cases of four planets, namely,the square and the rhombus. For the square case, we obtain that a square is a central configuration only in the case where the masses are equal and there exactly are two different square central configurations determined by the mass and the angular velocity; for the rhombus case, we obtain that if a rhombus is a central configuration, then the masses of the diagonal vertices must be equal. Furthermore, there are two or three or four different rhombus central configurations determined by the masses and the angular velocity.

  17. Central control of body temperature.

    Science.gov (United States)

    Morrison, Shaun F

    2016-01-01

    Central neural circuits orchestrate the behavioral and autonomic repertoire that maintains body temperature during environmental temperature challenges and alters body temperature during the inflammatory response and behavioral states and in response to declining energy homeostasis. This review summarizes the central nervous system circuit mechanisms controlling the principal thermoeffectors for body temperature regulation: cutaneous vasoconstriction regulating heat loss and shivering and brown adipose tissue for thermogenesis. The activation of these thermoeffectors is regulated by parallel but distinct efferent pathways within the central nervous system that share a common peripheral thermal sensory input. The model for the neural circuit mechanism underlying central thermoregulatory control provides a useful platform for further understanding of the functional organization of central thermoregulation, for elucidating the hypothalamic circuitry and neurotransmitters involved in body temperature regulation, and for the discovery of novel therapeutic approaches to modulating body temperature and energy homeostasis. PMID:27239289

  18. Space Radar Image of Central Sumatra, Indonesia

    Science.gov (United States)

    1994-01-01

    This is a radar image of the central part of the island of Sumatra in Indonesia that shows how the tropical rainforest typical of this country is being impacted by human activity. Native forest appears in green in this image, while prominent pink areas represent places where the native forest has been cleared. The large rectangular areas have been cleared for palm oil plantations. The bright pink zones are areas that have been cleared since 1989, while the dark pink zones are areas that were cleared before 1989. These radar data were processed as part of an effort to assist oil and gas companies working in the area to assess the environmental impact of both their drilling operations and the activities of the local population. Radar images are useful in these areas because heavy cloud cover and the persistent smoke and haze associated with deforestation have prevented usable visible-light imagery from being acquired since 1989. The dark shapes in the upper right (northeast) corner of the image are a chain of lakes in flat coastal marshes. This image was acquired in October 1994 by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour. Environmental changes can be easily documented by comparing this image with visible-light data that were acquired in previous years by the Landsat satellite. The image is centered at 0.9 degrees north latitude and 101.3 degrees east longitude. The area shown is 50 kilometers by 100 kilometers (31 miles by 62 miles). The colors in the image are assigned to different frequencies and polarizations of the radar as follows: red is L-band horizontally transmitted, horizontally received; green is L-band horizontally transmitted, vertically received; blue is L-band vertically transmitted, vertically received. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Mission to Planet Earth program.

  19. Lumenhaus solar decathlon team receives 2010 XCaliber Award

    OpenAIRE

    Owczarski, Mark

    2010-01-01

    Eight faculty members working collaboratively together on Virginia Tech's Lumenhaus solar decathlon project received the university's 2010 XCaliber Award for excellence in creating and applying technologies on a large scale team project.

  20. Technology Development for the Caltech Submillimeter Observatory Balanced Receivers

    CERN Document Server

    Kooi, J W; Monje, R; Force, B; Miller, D; Phillips, T G

    2012-01-01

    The Caltech Submillimeter Observatory (CSO) is located on top of Mauna Kea, Hawaii, at an altitude of 4.2 km. The existing suite of facility heterodyne receivers covering the submillimeter band is rapidly aging and in need of replacement. To facilitate deep integrations and automated spectral line surveys, a family of remote programmable, synthesized, dual-frequency balanced receivers covering the astronomical important 180 - 720 GHz atmospheric windows is in an advanced stage of development. Installation of the first set of receivers is expected in the spring of 2012. Dual-frequency observation will be an important mode of operation offered by the new facility instrumentation. Two band observations are accomplished by separating the H and V polarizations of the incoming signal and routing them via folded optics to the appropriate polarization sensitive balanced mixer. Scientifically this observation mode facilitates pointing for the higher receiver band under mediocre weather conditions and a doubling of sci...

  1. Brett Tyler receives 2009 Alumni Award for Excellence in Research

    OpenAIRE

    Sutphin, Michael D.

    2009-01-01

    Brett Tyler, research professor in the Virginia Bioinformatics Institute and professor of plant pathology, physiology, and weed science in the College of Agriculture and Life Sciences at Virginia Tech, received the university's 2009 Alumni Award for Excellence in Research.

  2. Code and codeless ionospheric measurements with NASA's Rogue GPS Receiver

    Science.gov (United States)

    Srinivasan, Jeff M.; Meehan, Tom K.; Young, Lawrence E.

    1989-01-01

    The NASA/JPL Rogue Receiver is an 8-satellite, non-multiplexed, highly digital global positioning system (GPS) receiver that can obtain dual frequency data either with or without knowledge of the P-code. In addition to its applications for high accuracy geodesy and orbit determination, the Rogue uses GPS satellite signals to measure the total electron content (TEC) of the ionosphere along the lines of sight from the receiver to the satellites. These measurements are used by JPL's Deep Space Network (DSN) for calibrating radiometric data. This paper will discuss Rogue TEC measurements, emphasizing the advantages of a receiver that can use the P-code, when available, but can also obtain reliable dual frequency data when the code is encrypted.

  3. Romesh C. Batra receives Alumni Award for Excellence in Research

    OpenAIRE

    Harris, Sally L.

    2004-01-01

    Romesh C. Batra, of Blacksburg, the Clifton C. Garvin Professor of Engineering Science and Mechanics in the College of Engineering at Virginia Tech, received a 2004 Alumni Award for Excellence in Research.

  4. David Nolfi Receives NAHRS Award for Professional Excellence

    Directory of Open Access Journals (Sweden)

    Maureen Diana Sasso

    2013-09-01

    Full Text Available News AnnouncementDavid A. Nolfi, MLS, AHIP, Health Sciences Librarian & Library Assessment Coordinator at Duquesne University’s Gumberg Library, received the 2013 NAHRS Award for Professional Excellence at the One Health Conference in Boston, MA.

  5. Optical Communication over Plastic Optical Fibers Integrated Optical Receiver Technology

    CERN Document Server

    Atef, Mohamed

    2013-01-01

    This book presents high-performance data transmission over plastic optical fibers (POF) using integrated optical receivers having good properties with multilevel modulation, i.e. a higher sensitivity and higher data rate transmission over a longer plastic optical fiber length. Integrated optical receivers and transmitters with high linearity are introduced for multilevel communication. For binary high-data rate transmission over plastic optical fibers, an innovative receiver containing an equalizer is described leading also to a high performance of a plastic optical fiber link. The cheap standard PMMA SI-POF (step-index plastic optical fiber) has the lowest bandwidth and the highest attenuation among multimode fibers. This small bandwidth limits the maximum data rate which can be transmitted through plastic optical fibers. To overcome the problem of the plastic optical fibers high transmission loss, very sensitive receivers must be used to increase the transmitted length over POF. The plastic optical fiber li...

  6. Administering truncated receive functions in a parallel messaging interface

    Energy Technology Data Exchange (ETDEWEB)

    Archer, Charles J; Blocksome, Michael A; Ratterman, Joseph D; Smith, Brian E

    2014-12-09

    Administering truncated receive functions in a parallel messaging interface (`PMI`) of a parallel computer comprising a plurality of compute nodes coupled for data communications through the PMI and through a data communications network, including: sending, through the PMI on a source compute node, a quantity of data from the source compute node to a destination compute node; specifying, by an application on the destination compute node, a portion of the quantity of data to be received by the application on the destination compute node and a portion of the quantity of data to be discarded; receiving, by the PMI on the destination compute node, all of the quantity of data; providing, by the PMI on the destination compute node to the application on the destination compute node, only the portion of the quantity of data to be received by the application; and discarding, by the PMI on the destination compute node, the portion of the quantity of data to be discarded.

  7. Water Fluoridation Statistics - Percent of PWS population receiving fluoridated water

    Data.gov (United States)

    U.S. Department of Health & Human Services — 2000-2014 Water Fluoridation Statistics is a biennial report of the percentage and number of people receiving fluoridated water from 2000 through 2014, originally...

  8. Low Complexity Receiver Design for MIMO-Radar

    KAUST Repository

    Ahmed, Sajid

    2012-09-08

    In this work, an algorithm for the multiple-input multiple-output (MIMO) radar is proposed. It has low computational complexity compared to the available schemes, and relatively low side-lobe-levels in the receive beampattern compared to the phased-array and MIMO-radar. In the proposed algorithm, the received signal vector of MIMO-radar is divided into sub-vectors, and each sub-vector is multiplied with the corresponding weight vector. The number of sub-vectors and weight vectors are optimally found to maximise the received signal power from the target of interest direction. The proposed scheme can be effectively applied in passive radars to minimise the side-lobe levels and place deep nulls for interferers in the receive beampattern. Simulation results show that the proposed scheme has relatively lower side lobe levels and better detection capabilities compared to MIMO-radar and phased-array.

  9. Next generation GNSS single receiver cycle slip reliability

    NARCIS (Netherlands)

    Teunissen, P.J.G.; De Bakker, P.F.

    2009-01-01

    In this contribution we study the multi-frequency, carrier-phase slip detection capabilities of a single receiver. Our analysis is based on an analytical expression that we present for themulti-frequencyminimal detectable carrier phase cycle slip.

  10. A Collective Detection Based GPS Receiver for Small Satellites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To solve the problem of autonomous navigation on small satellite platforms less than 20 kg, we propose to develop an onboard orbit determination receiver for small...

  11. 76 FR 67246 - Petition for Exemption; Summary of Petition Received

    Science.gov (United States)

    2011-10-31

    ... (65 FR 19477-78). Docket: To read background documents or comments received, go to http://www... that is exploring and developing oil fields located in the Kurdistan region of Iraq. BILLING CODE...

  12. Using a referee to resolve shipper-receiver differences

    International Nuclear Information System (INIS)

    Within the nuclear community, shipper-receiver differences generate considerable concern. Current methods of resolving these differences are discussed, prticularly the use of an umpire or referee. Numerous statistical problems connected with the present procedures are also considered

  13. Wavelength Drift Corrector for Wind Lidar Receivers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop and demonstrate an receiver system utilizing our novel technique for tracking and compensating for laser wavelength shifts in lidar systems....

  14. Recent progress in wide field-of-view optical receivers

    Institute of Scientific and Technical Information of China (English)

    LI GuangYuan; CAI Lin; XU AnShi

    2009-01-01

    The wide field-of-view (FOV) optical receiver has many advantages in optical wireless communication, sensing and detection. However, the FOV is limited by some tradeoffs of the receiver's components employing conventional optical devices. Furthermore, present mechanisms to extend the FOV are not effective. To realize the wide FOV receiver effectively, we propose surface plasmon polaritons (SPPs) as the potential candidate. Two examples are presented to lively illustrate SPPs' striking power to offer unexpected solutions to conventional problems. It is shown that unusual conditions should be ex-plored to make use of SPPs under some circumstances. Excitations of localized SPPs, which are in-dependent of the incidence angle, are suggested as the mechanism for the wide FOV receiver. Some progress Jn the optimization of SPPs' excitation at oblique incidence is also reported.

  15. Rod Youngman receives Alumni Award for Excellence in Extension

    OpenAIRE

    Greiner, Lori A.

    2008-01-01

    Rod Youngman of Blacksburg, Va., professor of entomology in the College of Agriculture and Life Sciences and Virginia Cooperative Extension specialist, has received Virginia Tech's 2008 Alumni Award for Excellence in Extension.

  16. German Antarctic Receiving Station (GARS) O'Higgins

    Science.gov (United States)

    Neidhardt, Alexander; Ploetz, Christian; Kluegel, Thomas

    2013-01-01

    In 2012, the German Antarctic Receiving Station (GARS) O'Higgins contributed to the IVS observing program with four observation sessions. Maintenance and upgrades were made, and a new replacement dewar is under construction in the observatory at Yebes, Spain.

  17. Design of Receiver Used for Passive Millimeter Wave Imaging System

    Directory of Open Access Journals (Sweden)

    Cheng Zheng

    2013-07-01

    Full Text Available As millimeter wave (MMW electronic technologies have matured, the MMW imaging using for human security inspection is emerging as an effective approach to imaging through obscuring materials, such as clothing for concealed weapons detection or plastic mines. This paper introduces temperature sensitivity firstly and then the fringe-washing functions are derived which decide the structure the antenna array and the receivers of the system BHU-2D. Finally, the fringe-washing functions and their phases are calculated from the frequency responses of 24-receiver, they all show good consistency of the receivers which also can be proved from the test results of receivers. From the final imaging of our system, the 1-2K temperature sensitivity is realized successfully.

  18. MULTI-GNSS RECEIVER FOR AEROSPACE NAVIGATION AND POSITIONING APPLICATIONS

    Directory of Open Access Journals (Sweden)

    T. R. Peres

    2014-03-01

    Full Text Available The upcoming Galileo system opens a wide range of new opportunities in the Global Navigation Satellite System (GNSS market. However, the characteristics of the future GNSS signals require the development of new GNSS receivers. In the frame of the REAGE project, DEIMOS and ISEL have developed a GNSS receiver targeted for aerospace applications, supporting current and future GPS L1 and Galileo E1 signals, based on commercial (or, in the furthest extent, industrial grade components. Although the REAGE project aimed at space applications, the REAGE receiver is also applicable to many terrestrial applications (ground or airborne, such as Georeferencing and Unmanned Aerial Vehicle (UAV navigation. This paper presents the architecture and features of the REAGE receiver, as well as some results of the validation campaign with GPS L1 and Galileo E1 signals.

  19. Microwave Receivers for Fast-Ion Detection in Fusion Plasmas

    DEFF Research Database (Denmark)

    Furtula, Vedran

    collective Thomson scattering (CTS). The Danish CTS group has been involved in fusion plasma experiments for more than 10 years and the future plans will most probably include the International Thermonuclear Experimental Reactor (ITER). Current CTS systems designed by the Danish group are specified...... are assessed. For the ITER HFS receiver we have designed and measured the quasioptical components that form a transmission link between the plasma and the radio frequency (RF) electronics. This HFS receiver is required to resolve the near parallel velocity components created by the alpha particles. Secondly...... have measured and analyzed all the receiver components starting from the two notch filters to the fifty square-law detector diodes. The receiver sensitivity is calculated from the system measurements and compared with the expected sensitivity based on the individual component measurements. Besides...

  20. Most Individuals Receive Health Services a Year Before Suicide Death

    Science.gov (United States)

    ... Individuals Receive Health Services a Year Before Suicide Death March 27, 2014 • Science Update Source: iStock Undetected ... care services in the year prior to suicide death and half did not have a mental health ...

  1. Higher performance and lower cost optical DPSK receiver Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To demonstrate (benchtop experiment) a DPSK receiver with a free-space interferometer, showing that fiber-optic coupling, associated adaptive optics, and optical...

  2. AEETES: A solar reflux receiver thermal performance numerical model

    Science.gov (United States)

    Hogan, R. E., Jr.

    1991-12-01

    Reflux solar receivers for dish-Stirling electric power generation systems are currently being investigated by several companies and laboratories. In support of these efforts, the AEETES thermal performance numerical model has been developed to predict thermal performance of pool-boiler and heat-pipe reflux receivers. The formulation of the AEETES numerical model, which is applicable to axisymmetric geometries with asymmetric incident fluxes, is presented in detail. Thermal efficiency predictions agree to within 4.1 percent with test data from on-sun tests of a pool-boiler reflux receiver. Predicted absorber and sidewall temperatures agree with thermocouple data to within 3.3. percent and 7.3 percent, respectively. The importance of accounting for the asymmetric incident fluxes is demonstrated in comparisons with predictions using azimuthally averaged variables. The predicted receiver heat losses are characterized in terms of convective, solar and infrared radiative, and conductive heat transfer mechanisms.

  3. Wavelength Drift Corrector for Wind Lidar Receivers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a key innovation to improve wavelength-sensitive lidar measurements (such as wind velocity) using photon-counting receivers. A novel binning technique to...

  4. SAW chirp Fourier transform for MB-OFDM UWB receiver

    Institute of Scientific and Technical Information of China (English)

    HE Peng-fei; L(U) Ying-hua; ZHANG Hong-xin; WANG Ye-qiu; XU Yong

    2006-01-01

    In the conventional multiband orthogonal frequency division multiplexing ultra wideband (MB-OFDM UWB )receiver, the fast Fourier transform (FFT) algorithm is realized by the expensive and power-consuming digital signal processor (DSP) chips. In this article, the lower power, lower cost, and lower complexity real-time analog surface acoustic wave (SAW)chirp Fourier transform devices were used to replace the DSP part. A MB-OFDM UWB receiver based on the M-C-M SAW chirp Fourier transform was presented, and the step of signal transformation from input signals was also depicted. The simulation results show that the proposed receiver provides similar bit error performance compared to the fully digital receiver when used in the channel environments proposed by the IEEE 802.15SG3a.

  5. RF-Frontend Design for Process-Variation-Tolerant Receivers

    CERN Document Server

    Sakian, Pooyan; van Roermund, Arthur

    2012-01-01

    This book discusses a number of challenges faced by designers of wireless receivers, given complications caused by the shrinking of electronic and mobile devices circuitry into ever-smaller sizes and the resulting complications on the manufacturability, production yield, and the end price of the products.  The authors describe the impact of process technology on the performance of the end product and equip RF designers with countermeasures to cope with such problems.  The mechanisms by which these problems arise are analyzed in detail and novel solutions are provided, including design guidelines for receivers with robustness to process variations and details of circuit blocks that obtain the required performance level. Describes RF receiver frontends and their building blocks from a system- and circuit-level perspective; Provides system-level analysis of a generic RF receiver frontend with robustness to process variations; Includes details of CMOS circuit design at 60GHz and reconfigurable circuits at 60GHz...

  6. 76 FR 410 - Petition for Exemption; Summary of Petition Received

    Science.gov (United States)

    2011-01-04

    ... (65 FR 19477-78). Docket: To read background documents or comments received, go to http://www... requirements of Sec. 21.603 for certain Traffic Collision Avoidance System (TCAS) computers that process...

  7. Faculty member receives American Agricultural Law Association highest honor

    OpenAIRE

    Sutphin, Michael D.

    2008-01-01

    L. Leon Geyer of Blacksburg, Va., professor of agricultural and applied economics in Virginia Tech's College of Agriculture and Life Sciences, has received the 2008 American Agricultural Law Association (AALA) Distinguished Service Award.

  8. Peter Doolittle receives 2010 Alumni Award for Excellence in Teaching

    OpenAIRE

    Owczarski, Mark

    2010-01-01

    Peter Doolittle of Christiansburg, Va., associate professor of education and director of the Center for Instructional Development and Educational Research at Virginia Tech, received the university's 2010 Alumni Award for Excellence in Teaching.

  9. Yalana B. Bryant receives education advocate of the year award

    OpenAIRE

    Harris, Jennifer

    2008-01-01

    Yalana B. Bryant, assistant director for diversity initiatives at Virginia Tech's Office of Undergraduate Admissions, recently received this year's American Association of University Women (AAUW) of Virginia's Education Advocate of the Year Award at a ceremony in Roanoke, Va.

  10. Influence of Frequency Offset on Modified EGC Diversity Receiver

    Directory of Open Access Journals (Sweden)

    B. Z. Nikolić

    2013-11-01

    Full Text Available In this paper a performance analysis of a modified M-ary phase-shift-keying (MPSK signal diversity receiver with a predetection equal gain combiner (EGC will be presented. The modification is in introducing a structure that performs the estimation with remodulation (ER. The EGC combining is realized by using a constant modulus algorithm (CMA. The influence of carrier frequency offset, length of ER structure and other parameters of the receiver will be examined.

  11. Photonic integrated transmitter and receiver for NG-PON2

    Science.gov (United States)

    Tavares, Ana; Lopes, Ana; Rodrigues, Cláudio; Mãocheia, Paulo; Mendes, Tiago; Brandão, Simão.; Rodrigues, Francisco; Ferreira, Ricardo; Teixeira, António

    2014-08-01

    In this paper the authors present a monolithic Photonic Integrated Circuit which includes a transmitter and a receiver for NG-PON2. With this layout it is possible to build an OLT and, by redesigning some filters, also an ONU. This technology allows reducing the losses in the transmitter and in the receiver, increasing power budget, and also reducing the OEO conversions, which has been a major problem that operators want to surpass.

  12. Information privacy, the right to receive information and (mobile ICTs

    Directory of Open Access Journals (Sweden)

    Litska Strikwerda

    2010-07-01

    Full Text Available The first part of this paper is about the notion of (information privacy and its grounding in law. It discusses the tension between the right to privacy and the right to receive information. The second part of this paper explores how (mobile ICTs challenge and complicate privacy claims and satisfy the right to receive information.http://dx.doi.org/10.5324/eip.v4i2.1761

  13. References Made and Citations Received by Scientific Articles

    OpenAIRE

    Albarrán, Pedro; Ruiz-Castillo, Javier

    2011-01-01

    This paper studies massive evidence about references made and citations received after a five-year citation window by 3.7 million articles published in 1998-2002 in 22 scientific fields. We find that the distributions of references made and citations received share a number of basic features across sciences. Reference distributions are rather skewed to the right, while citation distributions are even more highly skewed: the mean is about 20 percentage points to the right of the me...

  14. Digital coherent receiver for orbital angular momentum demultiplexing

    OpenAIRE

    Belmonte A.; Torres J.P.

    2013-01-01

    We put forward a type of receiver for coherent detection of the photon orbital angular momentum (OAM). A coherent array receiver, consisting of multiple subapertures, with each subaperture coupled to a single-mode fiber, maps the complex optical field in the image plane. Using digital samplers connected to each array element, the local electrical signals resulting from the detection process can be measured coherently, moving the complexity of the full OAM measurement from the optical domain t...

  15. Many southwest hosptials will receive decreased CMS reimbursement

    OpenAIRE

    Robbins RA

    2013-01-01

    No abstract available. Article truncated at 150 words. More hospitals are receiving penalties than bonuses in the second year of the Centers for Medicare and Medicaid Services’ (CMS) quality incentive program, and the average penalty is steeper than last year according to a report from Jordan Rau in Kaiser Health News (1). Southwest hospitals reflect that trend with New Mexico and Arizona exceeding the US average both in percentage of hospitals receiving penalties and the average size of the ...

  16. Optical coupling elements for coherent optical multiport receivers

    Science.gov (United States)

    Langenhorst, Ralf

    1992-05-01

    Three by three (3 by 3) and four by four (4 by 4) port coupling elements and receivers for heterodyne multiport systems are realized. Commercial (3 by 3) fiber coupling elements were used to achieve a usual (3 by 3) port receiver and a (3 by 3) port receiver in pushpull switching, whose concept was theoretically and experimentally analyzed. It is established that intensity oscillations of laser sources are suppressed by pushpull switching. The influence of thermal noise of opto-electronic input levels is shown to be weaker than in usual (3 by 3) port and (4 by 4) port receivers. Thermal noise effect in pushpull switching is similar to this one in heterodyne receivers. An integrated optical coupling element in LiNbO3 was made with bridge circuit from four waveguide coupling elements and two phase converters, which are electro-optically tunable so that a continuous regulation of intermediate frequency phase can be compensated by temperature variations of the element. To obtain fiber-to-fiber losses lower than a dB, a compact crystal optical coupling element was developed with reference to polarization properties of optical waves. This element supplied the eight necessary intermediate frequency output signals. A direct experimental comparison of bandwidth efficiency of multiport and heterodyne receivers shows a factor two in optical area and a factor three in electrical frequency area.

  17. Advanced Signal Processing for MIMO-OFDM Receivers

    DEFF Research Database (Denmark)

    Manchón, Carles Navarro

    This thesis deals with a wide range of topics within the research area of advanced baseband receiver design for wireless communication systems. In particular, the work focuses on signal processing algorithms for receivers in multiple-input multiple-output (MIMO) orthogonal frequency-division mult......This thesis deals with a wide range of topics within the research area of advanced baseband receiver design for wireless communication systems. In particular, the work focuses on signal processing algorithms for receivers in multiple-input multiple-output (MIMO) orthogonal frequency...... the structure of the receiver with the hope that the resulting heuristic architecture will exhibit the desired behavior and performance. On the other hand, one can employ analytical frameworks to pose the problem as the optimization of a global objective function subject to certain constraints. This work...... apply the combined message-passing algorithm to the probabilistic model of a MIMO-OFDM system; from the general derivation of the messages in the model, several instances of receiver structures with varying degrees of computational complexity and performance are obtained. We also explore...

  18. Holographic Optical Receiver Front End for Wireless Infrared Indoor Communications

    Science.gov (United States)

    Jivkova, S.; Kavehrad, M.

    2001-06-01

    Multispot diffuse configuration (MSDC) for indoor wireless optical communications, utilizing multibeam transmitter and angle diversity detection, is one of the most promising ways of achieving high capacities for use in high-bandwidth islands such as classrooms, hotel lobbies, shopping malls, and train stations. Typically, the optical front end of the receiver consists of an optical concentrator to increase the received optical signal power and an optical bandpass filter to reject the ambient light. Using the unique properties of holographic optical elements (HOE), we propose a novel design for the receiver optical subsystem used in MSDC. With a holographic curved mirror as an optical front end, the receiver would achieve more than an 10-dB improvement in the electrical signal-to-noise ratio compared with a bare photodetector. Features such as multifunctionality of the HOE and the receiver s small size, light weight, and low cost make the receiver front end a promising candidate for a user s portable equipment in broadband indoor wireless multimedia access.

  19. Heat Pipe Solar Receiver for Oxygen Production of Lunar Regolith

    Science.gov (United States)

    Hartenstine, John R.; Anderson, William G.; Walker, Kara L.; Ellis, Michael C.

    2009-03-01

    A heat pipe solar receiver operating in the 1050° C range is proposed for use in the hydrogen reduction process for the extraction of oxygen from the lunar soil. The heat pipe solar receiver is designed to accept, isothermalize and transfer solar thermal energy to reactors for oxygen production. This increases the available area for heat transfer, and increases throughput and efficiency. The heat pipe uses sodium as the working fluid, and Haynes 230 as the heat pipe envelope material. Initial design requirements have been established for the heat pipe solar receiver design based on information from the NASA In-Situ Resource Utilization (ISRU) program. Multiple heat pipe solar receiver designs were evaluated based on thermal performance, temperature uniformity, and integration with the solar concentrator and the regolith reactor(s). Two designs were selected based on these criteria: an annular heat pipe contained within the regolith reactor and an annular heat pipe with a remote location for the reactor. Additional design concepts have been developed that would use a single concentrator with a single solar receiver to supply and regulate power to multiple reactors. These designs use variable conductance or pressure controlled heat pipes for passive power distribution management between reactors. Following the design study, a demonstration heat pipe solar receiver was fabricated and tested. Test results demonstrated near uniform temperature on the outer surface of the pipe, which will ultimately be in contact with the regolith reactor.

  20. Wake-up receiver based ultra-low-power WBAN

    CERN Document Server

    Lont, Maarten; Roermund, Arthur van

    2014-01-01

    This book presents the cross-layer design and optimization of wake-up receivers for wireless body area networks (WBAN), with an emphasis on low-power circuit design. This includes the analysis of medium access control (MAC) protocols, mixer-first receiver design, and implications of receiver impairments on wideband frequency-shift-keying (FSK) receivers. Readers will learn how the overall power consumption is reduced by exploiting the characteristics of body area networks. Theoretical models presented are validated with two different receiver implementations, in 90nm and 40nm CMOS technology.   • Provides an overview of wireless body area network design from the network layer to the circuit implementation, and an overview of the cross-layer design trade-offs; • Discusses design at both the network or MAC-layer and circuit-level, with an emphasis on circuit design; • Covers the design of low-power frequency shift keying (FSK) wake-up-receivers; • Validates theory presented with two different recei...