Rim-drive cable-aligned heliostat collector system

DOEpatents

Dolan, J.E.; Sands, T.D.

1982-09-30

Disclosed is a heliostat collector apparatus comprising at least one heliostat suspended from a plurality of longitudinally extending linkage means. An enclosure structure is disposed adjacent the heliostat and provides a means for allowing the heliostat to be substantially protected from weathering. A first drive means is operatively connected to the heliostat to effect steering thereof in at least one of first and second predetermined directions. Finally, a frame member is adapted for supporting the heliostat at an inner portion thereof. The frame includes a plurality of outer expandable portions. Each one of the expandable portions is adapted to slidably engage a corresponding one of the plurality of linkage means. The expandable portions are further adapted to allow the heliostat to be slidably moved along the linkage means in directions away from and towards the enclosure structure and to substantially reduce stress acting on the heliostat during steering.

Rim-drive cable-aligned heliostat collector system

DOEpatents

Dolan, James E.; Sands, Timothy D.

1984-01-01

Disclosed is a heliostat collector apparatus comprising at least one heliostat suspended from a plurality of longitudinally extending linkage means. An enclosure structure is disposed adjacent the heliostat and provides a means for allowing the heliostat to be substantially protected from weathering. A first drive means is operatively connected to the heliostat to effect steering thereof in at least one of first and second predetermined directions. Finally, a frame member is adapted for supporting the heliostat at an inner portion thereof. The frame includes a plurality of outer expandable portions. Each one of the expandable portions is adapted to slidably engage a corresponding one of the plurality of linkage means. The expandable portions are further adapted to allow the heliostat to be slidably moved along the linkage means in directions away from and towards the enclosure structure and to substantially reduce stress acting on the heliostat during steering.

Effect of heliostat size on the levelized cost of electricity for power towers

NASA Astrophysics Data System (ADS)

Pidaparthi, Arvind; Hoffmann, Jaap

2017-06-01

The objective of this study is to investigate the effects of heliostat size on the levelized cost of electricity (LCOE) for power tower plants. These effects are analyzed in a power tower with a net capacity of 100 MWe, 8 hours of thermal energy storage and a solar multiple of 1.8 in Upington, South Africa. A large, medium and a small size heliostat with a total area of 115.56 m2, 43.3 m2 and 15.67 m2 respectively are considered for comparison. A radial-staggered pattern and an external cylindrical receiver are considered for the heliostat field layouts. The optical performance of the optimized heliostat field layouts has been evaluated by the Hermite (analytical) method using SolarPILOT, a tool used for the generation and optimization of the heliostat field layout. The heliostat cost per unit is calculated separately for the three different heliostat sizes and the effects due to size scaling, learning curve benefits and the price index is included. The annual operation and maintenance (O&M) costs are estimated separately for the three heliostat fields, where the number of personnel required in the field is determined by the number of heliostats in the field. The LCOE values are used as a figure of merit to compare the different heliostat sizes. The results, which include the economic and the optical performance along with the annual O&M costs, indicate that lowest LCOE values are achieved by the medium size heliostat with an area of 43.3 m2 for this configuration. This study will help power tower developers determine the optimal heliostat size for power tower plants currently in the development stage.

Influence of limited heliostat motion onto the efficiency of a solar field

NASA Astrophysics Data System (ADS)

Burisch, Michael; Mutuberria, Amaia; Olasolo, David; Villasante, Cristobal

2016-05-01

The efficiency of a central receiver solar thermal power plant depends on the ability of the heliostats to reflect the sunlight onto the receiver. Reflecting the sunlight over the course of a year requires the drive system to move the heliostat over a wide range of azimuth and elevation angles, which results to be a challenge in the development of new low cost drive system designs. Reducing this range simplifies the design and would, therefore, enable further cost savings. At the same time, reducing the range would also cause efficiency losses of the solar field, as the heliostats would not be able to reflect the sunlight under all conditions. Analyzing the range of motions required for each heliostat and the flux contribution of each position allows assessing these losses. With the aim of minimizing the losses an optimal range of heliostat motions can be chosen. It is shown that in combination with properly placing each heliostat in the solar field, the efficiency losses due to the limited motion range can be kept low as most of the receiver incident flux results from a small range of heliostat orientations. If such a heliostat design allow for sufficiently high costs saving per heliostat the potential losses can be compensated by adding more heliostats to the field, while still reducing the overall expenses.

A new code for the design and analysis of the heliostat field layout for power tower system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wei, Xiudong; Lu, Zhenwu; Yu, Weixing

2010-04-15

A new code for the design and analysis of the heliostat field layout for power tower system is developed. In the new code, a new method for the heliostat field layout is proposed based on the edge ray principle of nonimaging optics. The heliostat field boundary is constrained by the tower height, the receiver tilt angle and size and the heliostat efficiency factor which is the product of the annual cosine efficiency and the annual atmospheric transmission efficiency. With the new method, the heliostat can be placed with a higher efficiency and a faster response speed of the design andmore » optimization can be obtained. A new module for the analysis of the aspherical heliostat is created in the new code. A new toroidal heliostat field is designed and analyzed by using the new code. Compared with the spherical heliostat, the solar image radius of the field is reduced by about 30% by using the toroidal heliostat if the mirror shape and the tracking are ideal. In addition, to maximize the utilization of land, suitable crops can be considered to be planted under heliostats. To evaluate the feasibility of the crop growth, a method for calculating the annual distribution of sunshine duration on the land surface is developed as well. (author)« less

Development of the ASTRI heliostat

NASA Astrophysics Data System (ADS)

Coventry, Joe; Arjomandi, Maziar; Barry, John; Blanco, Manuel; Burgess, Greg; Campbell, Jonathan; Connor, Phil; Emes, Matthew; Fairman, Philip; Farrant, David; Ghanadi, Farzin; Grigoriev, Victor; Hall, Colin; Koltun, Paul; Lewis, David; Martin, Scott; Nathan, Graham; Pye, John; Qiu, Ang; Stuart, Wayne; Tang, Youhong; Venn, Felix; Yu, Jeremy

2016-05-01

The Australian Solar Thermal Research Initiative (ASTRI) aims to develop a high optical quality heliostat with target cost - manufactured, installed and operational - of 90 AUD/m2. Three different heliostat design concepts are described, each with features identified during a prior scoping study as having the potential to contribute to cost reduction compared to the current state-of-the-art. The three concepts which are being developed will be down-selected to a single concept for testing in late 2016. The heliostat concept development work is supported by technology development streams, developing novel sandwich panel mirror facet structures, analysing and testing wind loads on heliostats in both stow and operation positions, and developing new heliostat field layouts and software tools for optical analysis of heliostats design concepts.

Field-design optimization with triangular heliostat pods

NASA Astrophysics Data System (ADS)

Domínguez-Bravo, Carmen-Ana; Bode, Sebastian-James; Heiming, Gregor; Richter, Pascal; Carrizosa, Emilio; Fernández-Cara, Enrique; Frank, Martin; Gauché, Paul

2016-05-01

In this paper the optimization of a heliostat field with triangular heliostat pods is addressed. The use of structures which allow the combination of several heliostats into a common pod system aims to reduce the high costs associated with the heliostat field and therefore reduces the Levelized Cost of Electricity value. A pattern-based algorithm and two pattern-free algorithms are adapted to handle the field layout problem with triangular heliostat pods. Under the Helio100 project in South Africa, a new small-scale Solar Power Tower plant has been recently constructed. The Helio100 plant has 20 triangular pods (each with 6 heliostats) whose positions follow a linear pattern. The obtained field layouts after optimization are compared against the reference field Helio100.

Central solar-energy receiver

DOEpatents

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.

Central solar energy receiver

DOEpatents

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.

Techno-economic sensitivity study of heliostat field parameters for micro-gas turbine CSP

NASA Astrophysics Data System (ADS)

Landman, Willem A.; Gauché, Paul; Dinter, Frank; Myburgh, J. T.

2017-06-01

Concentrating solar power systems based on micro-gas turbines potentially offer numerous benefits should they become commercially viable. Heliostat fields for such systems have unique requirements in that the number of heliostats and the focal ratios are typically much lower than conventional central receiver systems. This paper presents a techno-economic sensitivity study of heliostat field parameters for a micro-gas turbine central receiver system. A 100 kWe minitower system is considered for the base case and a one-at-a-time strategy is used to investigate parameter sensitivities. Increasing heliostat focal ratios are found to have significant optical performance benefits due to both a reduction in astigmatic aberrations and a reduction in the number of facet focal lengths required; confirming the hypothesis that smaller heliostats offer a techno-economic advantage. Fixed Horizontal Axis tracking mechanism is shown to outperform the conventional Azimuth Zenith tracking mechanism in high density heliostat fields. Although several improvements to heliostat field performance are discussed, the capex fraction of the heliostat field for such system is shown to be almost half that of a conventional central receiver system and optimum utilization of the higher capex components, namely; the receiver and turbine subsystems, are more rewarding than that of the heliostat field.

Chemical looping fluidized-bed concentrating solar power system and method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Zhiwen

A concentrated solar power (CSP) plant comprises a receiver configured to contain a chemical substance for a chemical reaction and an array of heliostats. Each heliostat is configured to direct sunlight toward the receiver. The receiver is configured to transfer thermal energy from the sunlight to the chemical substance in a reduction reaction. The CSP plant further comprises a first storage container configured to store solid state particles produced by the reduction reaction and a heat exchanger configured to combine the solid state particles and gas through an oxidation reaction. The heat exchanger is configured to transfer heat produced inmore » the oxidation reaction to a working fluid to heat the working fluid. The CSP plant further comprises a power turbine coupled to the heat exchanger, such that the heated working fluid turns the power turbine, and a generator coupled to and driven by the power turbine to generate electricity.« less

Low Cost Heliostat Development Phase II Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kusek, Stephen M.

2013-04-30

The heliostat field in a central receiver plant makes up roughly one half of the total plant cost. As such, cost reductions for the installed heliostat price greatly impact the overall plant cost and hence the plant’s Levelized Cost of Energy. The general trend in heliostat size over the past decades has been to make them larger. One part of our thesis has been that larger and larger heliostats may drive the LCOE up instead of down due to the very nature of the precise aiming and wind-load requirements for typical heliostats. In other words, it requires more and moremore » structure to precisely aim the sunlight at the receiver as one increases heliostat mirror area and that it becomes counter-productive, cost-wise, at some point.« less

Use of MEMs and optical sensors for closed loop heliostat control

NASA Astrophysics Data System (ADS)

Harper, Paul Julian; Dreijer, Janto; Malan, Karel; Larmuth, James; Gauche, Paul

2016-05-01

The Helio 100 project at STERG (Stellenbosch Solar Thermal Research Group) aims to help reduce the cost of Concentrated Solar Thermal plants by deploying large numbers of small (1x2 m) low cost heliostats. One of the methods employed to reduce the cost of the heliostat field is to have a field that requires no site preparation (grading, leveling, vegetation clearance) and no expensive foundations or concrete pouring for each individual heliostat base. This implies that the heliostat pod frames and vertical mounts might be slightly out of vertical, and the normal method of dead reckoning using accurately surveyed and aligned heliostat bases cannot be used. This paper describes a combination of MEMs and optical sensors on the back of the heliostat, that together with a simple machine learning approach, give accurate and reproducible azimuth and elevation information for the heliostat plane. Initial experiments were done with an android phone mounted on the back of a heliostat as it was a readily available platform combining accelerometers' and camera into one programmable package. It was found quite easy to determine the pointing angle of the heliostat to within 1 milliradian using the rear facing camera and correlating known heliostat angles with target image features on the ground. We also tested the accuracy at various image resolutions by halving the image size successively till the feature detection failed. This showed that even a VGA (640x480) resolution image could give mean errors of 1.5 milliradian. The optical technique is exceedingly simple and does not use any camera calibration, angular reconstruction or knowledge of heliostat drive geometry. We also tested the ability of the 3d accelerometers to determine angle, but this was coarser than the camera and only accurate to around 10 milliradians.

Status of stretched-membrane heliostats

NASA Astrophysics Data System (ADS)

Alpert, D. J.; Houser, R. M.; Heckes, A. A.

1990-01-01

Since the early 1980s, Sandia National Laboratories has been developing stretched-membrane heliostats for solar central receiver power plants. They differ from conventional glass-mirror heliostats in that the optical surface is a stretched membrane -- a thin metal foil stretched over both sides of a large diameter ring. The reflective surface is provided by either a silvered-acrylic film or thin glass mirrors attached to the front membrane. Heliostats with single 14 m diameter (150 sq meter) stretched-membrane reflectors have been designed. Because of their simplicity and light weight, stretched-membrane heliostats are expected to cost up to one-third less than conventional glass-mirror designs. Two generations of 50 sq meter prototype stretched-membrane mirror modules have been built and evaluated at Sandia's Central Receiver Test Facility in Albuquerque, NM. They demonstrated that the optical performance of membrane heliostats rivals that of glass-mirror heliostats. The durability of the silvered-acrylic reflective film has improved so that a lifetime of at least 5 years is likely; methods of replacing the film in the field are being investigated. Sandia recently initiated the final phase of development: the design of fully integrated, market-ready heliostats. Field tests of these heliostats are planned to begin in FY90.

Reducing heliostat field costs by direct measurement and control of the mirror orientation

NASA Astrophysics Data System (ADS)

van den Donker, P.; Rosinga, G.; van Voorthuysen, E. du Marchie

2016-05-01

The first commercial CSP Central Receiver System has been in operation since 2007. The technology required for such a central receiver system is quite new. The determining factor of the price of electricity is the capital investment in the heliostat field. The cost level per square meter of the heliostat field is rather high. Sun2point is questioning the market development, which is trying to get the cost level down by aiming at large heliostats. Sun2Point aims at mass manufacturing small heliostats to achieve low prices. Mass manufacturing off-site and transport over long distances is possible for small heliostats only. Calibration on the spot is a labour-intensive activity. Autonomous, factory calibrated and wireless controlled heliostats are the solution to lower installation cost. A new measurement method that directly reports the orientation of the heliostat in relation to the earth and the sun can solve the calibration problem when the heliostats are installed. The application of small heliostats will be much cheaper as a result of this measurement method. In this paper several methods for such a measurement are described briefly. The new Sun2Point method has successfully been tested. In this paper Sun2Point challenges the CSP community to investigate this approach. A brief survey is presented of many aspects that lead to a low price.

Optical advantages of astigmatic aberration corrected heliostats

NASA Astrophysics Data System (ADS)

van Rooyen, De Wet; Schöttl, Peter; Bern, Gregor; Heimsath, Anna; Nitz, Peter

2016-05-01

Astigmatic aberration corrected heliostats adapt their shape in dependence of the incidence angle of the sun on the heliostat. Simulations show that this optical correction leads to a higher concentration ratio at the target and thus in a decrease in required receiver aperture in particular for smaller heliostat fields.

Simultaneous optimization of micro-heliostat geometry and field layout using a genetic algorithm

NASA Astrophysics Data System (ADS)

Lazardjani, Mani Yousefpour; Kronhardt, Valentina; Dikta, Gerhard; Göttsche, Joachim

2016-05-01

A new optimization tool for micro-heliostat (MH) geometry and field layout is presented. The method intends simultaneous performance improvement and cost reduction through iteration of heliostat geometry and field layout parameters. This tool was developed primarily for the optimization of a novel micro-heliostat concept, which was developed at Solar-Institut Jülich (SIJ). However, the underlying approach for the optimization can be used for any heliostat type. During the optimization the performance is calculated using the ray-tracing tool SolCal. The costs of the heliostats are calculated by use of a detailed cost function. A genetic algorithm is used to change heliostat geometry and field layout in an iterative process. Starting from an initial setup, the optimization tool generates several configurations of heliostat geometries and field layouts. For each configuration a cost-performance ratio is calculated. Based on that, the best geometry and field layout can be selected in each optimization step. In order to find the best configuration, this step is repeated until no significant improvement in the results is observed.

Heliostat kinematic system calibration using uncalibrated cameras

NASA Astrophysics Data System (ADS)

Burisch, Michael; Gomez, Luis; Olasolo, David; Villasante, Cristobal

2017-06-01

The efficiency of the solar field greatly depends on the ability of the heliostats to precisely reflect solar radiation onto a central receiver. To control the heliostats with such a precision accurate knowledge of the motion of each of them modeled as a kinematic system is required. Determining the parameters of this system for each heliostat by a calibration system is crucial for the efficient operation of the solar field. For small sized heliostats being able to make such a calibration in a fast and automatic manner is imperative as the solar field potentially contain tens or even hundreds of thousands of them. A calibration system which can rapidly recalibrate a whole solar field would also allow reducing costs. Heliostats are generally designed to provide stability over a large period of time. Being able to relax this requirement and compensate any occurring error by adapting parameters in a model, the costs of the heliostat can be reduced. The presented method describes such an automatic calibration system using uncalibrated cameras rigidly attached to each heliostat. The cameras are used to observe targets spread out through the solar field; based on this the kinematic system of the heliostat can be estimated with high precision. A comparison of this approach to similar solutions shows the viability of the proposed solution.

Who's hot, who's not? Effects of concentrating solar power heliostats on soil temperature at Ivanpah Solar Electric Generating System, Mojave Desert, USA

NASA Astrophysics Data System (ADS)

Grodsky, S.; Hernandez, R. R.

2017-12-01

Solar energy development may function as a contemporary, anthropogenic driver of disturbance when sited in natural ecosystems. Orientation and density of solar modules, including heliostats at concentrating solar power (CSP) facilities, may affect soils via shading and altered surface-water flow. Meanwhile, soil attributes like temperature and moisture may affect nutrient cycling, plant germination and growth, and soil biota. We tested effects of CSP heliostats on soil temperature at Ivanpah Solar Electric Generating System (ISEGS) in the Mojave Desert, USA. We implemented experimental treatments based on preconstruction rare plant [e.g., Mojave milkweed (Asclepias nyctaginifolia)] protection areas (hereafter "halos"), site preparation activities, and heliostat density throughout three, replicated CSP blocks (i.e., tower and associated heliostats), including: (1) No Halos (Bladed) - high site preparation intensity, high heliostat density immediately surrounding towers; (2) No Halos (Mowed) - moderate site preparation intensity, moderate to low heliostat density as distance increases from towers; and (3) Halos - no site preparation, no heliostats. We also established control sites within 1,600 km of ISEGS in undisturbed desert. We observed significant differences in soil temperature across treatments. We recorded significantly lower soil temperatures in the No Halos (Bladed) treatments (26.7°C) and No Halos (Mowed) treatments (29.9°C) than in the Halos treatments (32.9°C) and controls (32.1°C). We also determined that soil temperatures in the Halos treatments and controls did not significantly differ. Our results indicated that shading from high-density heliostat configuration significantly reduced soil temperature relative to low-density heliostat configuration and areas without CSP. Shading from heliostats and consequential fluctuation in soil temperatures may affect local-scale distribution of flora and fauna, leading to altered "bottom-up" ecological interactions at ISEGS.

Heliostat with Stowing and Wind Survival Capabilities

NASA Technical Reports Server (NTRS)

Nesmith, Bill J. (Inventor)

2018-01-01

A low cost thin-film based heliostat with advanced stowing and wind survival capabilities. The heliostat may include a plurality of reflective surfaces held together via a plurality of double acting magnetic hinges. The heliostat may also include a drive mechanism attached to a post, and configured to stow the plurality of facets in any desired position.

Heliostat design for the daylighting system.

PubMed

Chang, Chih-Hung; Hsiso, Horng-Ching; Chang, Cheng-Ming; Wang, Chen-You; Lin, Tzung-Han; Chen, Yi-Yung; Lai, Yi-Lung; Yen, Cho-Jung; Chen, Kuan-Yu; Whang, Allen Jong-Woei

2014-10-10

The daylighting system is designed to guide sunlight into buildings for illumination. It has the best illumination performance when sunlight vertically impinges on the collector of the daylighting system, while it has low performance when sunlight impinges obliquely. To overcome the problem, this paper investigates the design of a heliostat that reflects sunlight vertically onto a daylighting system. This study proposes a 3×3 mirror matrix heliostat, which is different from the traditional heliostat with one single mirror. With the heliostat, the system efficiency increases as high as 3.32 times.

Inverse kinematics of a dual linear actuator pitch/roll heliostat

NASA Astrophysics Data System (ADS)

Freeman, Joshua; Shankar, Balakrishnan; Sundaram, Ganesh

2017-06-01

This work presents a simple, computationally efficient inverse kinematics solution for a pitch/roll heliostat using two linear actuators. The heliostat design and kinematics have been developed, modeled and tested using computer simulation software. A physical heliostat prototype was fabricated to validate the theoretical computations and data. Pitch/roll heliostats have numerous advantages including reduced cost potential and reduced space requirements, with a primary disadvantage being the significantly more complicated kinematics, which are solved here. Novel methods are applied to simplify the inverse kinematics problem which could be applied to other similar problems.

Heliostat cost optimization study

NASA Astrophysics Data System (ADS)

von Reeken, Finn; Weinrebe, Gerhard; Keck, Thomas; Balz, Markus

2016-05-01

This paper presents a methodology for a heliostat cost optimization study. First different variants of small, medium sized and large heliostats are designed. Then the respective costs, tracking and optical quality are determined. For the calculation of optical quality a structural model of the heliostat is programmed and analyzed using finite element software. The costs are determined based on inquiries and from experience with similar structures. Eventually the levelised electricity costs for a reference power tower plant are calculated. Before each annual simulation run the heliostat field is optimized. Calculated LCOEs are then used to identify the most suitable option(s). Finally, the conclusions and findings of this extensive cost study are used to define the concept of a new cost-efficient heliostat called `Stellio'.

Closed-loop control for power tower heliostats

NASA Astrophysics Data System (ADS)

Convery, Mark R.

2011-10-01

In a Power Tower solar thermal power plant, alignment and control of the heliostats constitutes one of the largest costs of both time and money. This is especially the case in systems where individual heliostats are small (~1m2). I describe a closed-loop control system that generates the required feedback by inducing small mechanical vibrations in the heliostat reflector surface using piezoelectric actuators. These vibrations induce time-dependent changes in the reflected wavefront that can be detected by photosensors surrounding the thermal receiver target. Time and frequency encoding of the vibrations allows identification of a misaligned heliostat from among the thousands in the system. Corrections can then be applied to bring the reflected beam onto the receiver target. This technique can, in principle, control thousands of heliostats simultaneously.Outdoor testing of a small-scale model of this system has confirmed that such a system is effective and can achieve milliradian tracking accuracy. If such a system were implemented in a commercial plant, it could relax the accuracy specification required of the heliostats as well as provide an automated alignment and calibration system. This could significantly reduce the installed cost of the heliostat field.

Novel imaging closed loop control strategy for heliostats

NASA Astrophysics Data System (ADS)

Bern, Gregor; Schöttl, Peter; Heimsath, Anna; Nitz, Peter

2017-06-01

Central Receiver Systems use up to thousands of heliostats to concentrate solar radiation. The precise control of heliostat aiming points is crucial not only for efficiency but also for reliable plant operation. Besides the calibration of open loop control systems, closed loop tracking strategies are developed to address a precise and efficient aiming strategy. The need for cost reductions in the heliostat field intensifies the motivation for economic closed loop control systems. This work introduces an approach for a closed loop heliostat tracking strategy using image analysis and signal modulation. The approach aims at the extraction of heliostat focal spot position within the receiver domain by means of a centralized remote vision system decoupled from the rough conditions close to the focal area. Taking an image sequence of the receiver while modulating a signal on different heliostats, their aiming points are retrieved. The work describes the methodology and shows first results from simulations and practical tests performed in small scale, motivating further investigation and deployment.

A top-down approach to heliostat cost reduction

NASA Astrophysics Data System (ADS)

Larmuth, James N.; Landamn, Willem A.; Gauché, Paul

2016-05-01

The Technology Innovation Agency (TIA) has funded a South African central receiver collector technology development project, called Helio100. The project aims to provide South Africa's first commercially viable heliostat technology, which is both low in cost and offers high local content potential. A top-down approach is employed for heliostat cost reduction. This approach incorporates interlinked tools which move from high level cost analyses based on qualitative data during early stages of conceptual design, to detailed quantitative analyses in the final stages of design. Low cost heliostat designs are realized by the incorporation of both a top-down and bottom-up method. The current H100 design results in heliostat costs of 155/m2 at 20 000 units p.a. while further industrialisation results in heliostat costs of 126/m2 at 20 000 units.

Fluid flow analysis behind heliostat using LES and RANS: A step towards optimized field design in desert regions

NASA Astrophysics Data System (ADS)

Boddupalli, Nibodh; Goenka, Vikash; Chandra, Laltu

2017-06-01

Heliostats are used for concentrating beam radiation onto a receiver. The flow induced dust deposition on these reflectors will lead to failure of the receiver. For this purpose, the wake behind a heliostat is analyzed at 25° of inclination and at a Reynolds number of 60000. In this paper the Reynolds Averaged Navier-Stokes (RANS) and the Large Eddy Simulation (LES) approaches are used for analyzing the air-flow behind a heliostat. LES and RANS are performed with a wall-resolved grid. For the purpose of validation, the horizontal velocity is measured in a wind-tunnel with a model heliostat using laser Doppler velocimetry technique. RANS and LES approaches are found to qualitatively predict the statistical quantities, like the mean horizontal-velocity in comparison to experiment. RANS under-predicts root-mean-square of the horizontal-velocity and even failed to capture the flow features behind heliostat. Thus, it is concluded that RANS will suffice with well-resolved grid for analyzing mean flow features. For analyzing wake and to understand the induced dust deposition LES is required. Further, the analysis reveals that the wake-affected region is up to three times the length of the heliostat's mirror. This can be recommended as the minimum distance between any two aligned heliostats in Jodhpur.

A universal heliostat control system

NASA Astrophysics Data System (ADS)

Gross, Fabian; Geiger, Mark; Buck, Reiner

2017-06-01

This paper describes the development of a universal heliostat control system as part of the AutoR project [1]. The system can control multiple receivers and heliostat types in a single application. The system offers support for multiple operators on different machines and is designed to be as adaptive as possible. Thus, the system can be used for different heliostat field setups with only minor adaptations of the system's source code. This is achieved by extensive usage of modern programming techniques like reflection and dependency injection. Furthermore, the system features co-simulation of a ray tracer, a reference PID-controller implementation for open volumetric receivers and methods for heliostat calibration and monitoring.

An improved methodology for heliostat testing and evaluation at the Plataforma Solar de Almería

NASA Astrophysics Data System (ADS)

Monterreal, Rafael; Enrique, Raúl; Fernández-Reche, Jesús

2017-06-01

The optical quality of a heliostat basically quantifies the difference between the scattering effects of the actual solar radiation reflected on its optical surface, compared to the so called canonical dispersion, that is, the one reflected on an optical surface free of constructional errors (paradigm). However, apart from the uncertainties of the measuring process itself, the value of the optical quality must be independent of the measuring instrument; so, any new measuring techniques that provide additional information about the error sources on the heliostat reflecting surface would be welcome. That error sources are responsible for the final optical quality value, with different degrees of influence. For the constructor of heliostats it will be extremely useful to know the value of the classical sources of error and their weight on the overall optical quality of a heliostat, such as facets geometry or focal length, as well as the characteristics of the heliostat as a whole, i.e., its geometry, focal length, facets misalignment and also the possible dependence of these effects with mechanical and/or meteorological factors. It is the goal of the present paper to unfold these optical quality error sources by exploring directly the reflecting surface of the heliostat with the help of a laser-scanner device and link the result with the traditional methods of heliostat evaluation at the Plataforma Solar de Almería.

Analytic method for material aging and quality analyzing to forecast long time stability of plastic micro heliostat components

NASA Astrophysics Data System (ADS)

Sauerborn, Markus; Liebenstund, Lena; Raue, Markus; Mang, Thomas; Herrmann, Ulf; Dueing, Andreas

2017-06-01

The Solar-Institute Jülich (SIJ) developed the micro heliostat system - a small sized heliostat - during the last years. One special performance of the micro heliostat is the option to integrate inexpensive plastic elements. The use of plastic as a cost reducer in the heliostat technique is also offering the chance to integrate complex designed components with a higher quality and special system function. The plastic for this application requires a high standing against UV radiation and thermal cycles with a daily extreme temperature variation. The temperature range inside the closed micro heliostat box can annually fluctuate between -20 °C and 80 °C in the worst case. Special aging tests were designed and performed for the first time in cooperation with the Institute for Applied Polymer Science (IAP) in order to identify and qualify a resistance plastic for the micro heliostat. This systematic plastic aging testing for the micro heliostat is introduced here. The tests were carried out under extreme ambient situations, which simulate the temperature and irradiation conditions that the heliostat has to stand for years. A particular climate of arid areas with continuous high solar radiation was defined for these tests. Two accelerating aging methods were adapted to reach adequate aging results in a reduced time. The aging of the investigated kinds of plastics were followed by tensile test, impact test, measuring Shore hardness, dynamic-mechanical analysis, differential scanning calorimetry and Fourier transform infrared spectroscopy to compare the different types of polymers. Parallel to these tests running real outdoor tests were performed, to control this accelerated aging. To have adequate conditions that the plastic in a micro heliostat has to stand, an identical closed test box with a glass cover was designed. The test samples inside the box were irradiated by the sun. The wanted forecast for the analyzed plastic was defined by the comparison of the real and the accelerated aging results.

Automatic control of solar power plants

NASA Astrophysics Data System (ADS)

Ermakov, V. S.; Dubilovich, V. M.

1982-02-01

The automatic control of the heliostat field of a 200-MW solar power plant is discussed. The advantages of the decentralized control principle with the solution of a number of individual problems in a single control center are emphasized. The basic requirements on heliostat construction are examined, and possible functional schemes for the automatic control of a heliostat field are described. It is proposed that groups of heliostats can be controlled from a single center and on the basis of a single algorithm.

Influence of the gap size on the wind loading on heliostats

NASA Astrophysics Data System (ADS)

Poulain, Pierre E.; Craig, Ken J.; Meyer, Josua P.

2016-05-01

Generally built in desert areas, heliostat fields undergo various wind loading conditions. An ANSYS Fluent CFD model of an isolated heliostat in worst-case orientation for the drag force is realized via numerical simulations using the realizable k-ɛ turbulence model. This paper focuses on the gap width between the panels and its influence on the wind loading that heliostats are subjected to. An atmospheric boundary layer profile is generated based on a wind tunnel experiment. For a heliostat in upright and tilted orientations with the wind angle being zero degrees, the gap width is varied and the force and moment coefficients are calculated. In the range tested, all the coefficients globally increase with the widening of the gaps.

Heliostat control

DOEpatents

Kaehler, James A.

1984-01-01

An improvement in a system and method of controlling heliostat in which the heliostat is operable in azimuth and elevation by respective stepper motors and including the respective steps or means for calculating the position for the heliostat to be at a commanded position, determining the number of steps in azimuth and elevation for each respective motor to get to the commanded position and energizing both the azimuth and elevation stepper motors to run in parallel until predetermined number of steps away from the closest commanded position in azimuth and elevation so that the closest position has been achieved, and thereafter energizing only the remaining motor to bring it to its commanded position. In this way, the heliostat can be started from a stowed position in the morning and operated by a computer means to its commanded position and kept correctly oriented throughout the day using only the time of the day without requiring the usual sensors and feedback apparatus. A computer, or microprocessor, can then control a plurality of many heliostats easily and efficiently throughout the day.

THE DESIGN AND FABRICATION OF A LOWER COST HELIOSTAT MIRROR SYSTEM FOR UTILIZING SOLAR ENERGY

EPA Science Inventory

A heliostat is a mirror based system which is used to continuously reflect sunlight onto a central receiver. The collected solar energy is then converted into electrical power. Currently, costs associated with the construction and maintenance of heliostats have proven prohibit...

Friction Effects on Inertia Compensators used for Heliostat Base Motion Isolation.

DTIC Science & Technology

The base motion isolation of an optical beam deflector with a two-axis gimbal support ( heliostat ) is discussed. The use of an auxiliary inertia...coupled between the elevation gimbal and the heliostat mirror to produce a compensating torque referred to as a gear compensator and a belt compensator

Ultra-modular 500m2 heliostat field for high flux/high temperature solar-driven processes

NASA Astrophysics Data System (ADS)

Romero, Manuel; González-Aguilar, José; Luque, Salvador

2017-06-01

The main objective of the European Project SUN-to-LIQUID is the scale-up and experimental demonstration of the complete process chain to solar liquid fuels from H2O and CO2. This implies moving from a 4 kW laboratory setup to a pre-commercial plant including a heliostat field. The small power and high irradiance onto the focal spot is forcing the optical design to behave half way between a large solar furnace and an extremely small central receiver system. The customized heliostat field makes use of the most recent developments on small size heliostats and a tower with reduced optical height (15 m) to minimize visual impact. A heliostat field of 250kWth (500 m2 reflective surface) has been built adjacent to IMDEA Energy premises at the Technology Park of Móstoles, Spain, and consists of 169 small size heliostats (1.9 m × 1.6 m). In spite of the small size and compactness of the field, when all heliostats are aligned, it is possible to fulfil the specified flux above 2500 kW/m2 for at least 50 kW and an aperture of 16 cm, with a peak flux of 3000 kW/m2.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wagner, Michael; Ma, Zhiwen; Martinek, Janna

An aspect of the present disclosure is a receiver for receiving radiation from a heliostat array that includes at least one external panel configured to form an internal cavity and an open face. The open face is positioned substantially perpendicular to a longitudinal axis and forms an entrance to the internal cavity. The receiver also includes at least one internal panel positioned within the cavity and aligned substantially parallel to the longitudinal axis, and the at least one internal panel includes at least one channel configured to distribute a heat transfer medium.

Selecting a proper design period for heliostat field layout optimization using Campo code

NASA Astrophysics Data System (ADS)

Saghafifar, Mohammad; Gadalla, Mohamed

2016-09-01

In this paper, different approaches are considered to calculate the cosine factor which is utilized in Campo code to expand the heliostat field layout and maximize its annual thermal output. Furthermore, three heliostat fields containing different number of mirrors are taken into consideration. Cosine factor is determined by considering instantaneous and time-average approaches. For instantaneous method, different design days and design hours are selected. For the time average method, daily time average, monthly time average, seasonally time average, and yearly time averaged cosine factor determinations are considered. Results indicate that instantaneous methods are more appropriate for small scale heliostat field optimization. Consequently, it is proposed to consider the design period as the second design variable to ensure the best outcome. For medium and large scale heliostat fields, selecting an appropriate design period is more important. Therefore, it is more reliable to select one of the recommended time average methods to optimize the field layout. Optimum annual weighted efficiency for heliostat fields (small, medium, and large) containing 350, 1460, and 3450 mirrors are 66.14%, 60.87%, and 54.04%, respectively.

Low-profile heliostat design for solar central receiver systems

NASA Technical Reports Server (NTRS)

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.

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

NASA Astrophysics Data System (ADS)

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 heliostat field.

Backward-gazing method for heliostats shape errors measurement and calibration

NASA Astrophysics Data System (ADS)

Coquand, Mathieu; Caliot, Cyril; Hénault, François

2017-06-01

The pointing and canting accuracies and the surface shape of the heliostats have a great influence on the solar tower power plant efficiency. At the industrial scale, one of the issues to solve is the time and the efforts devoted to adjust the different mirrors of the faceted heliostats, which could take several months if the current methods were used. Accurate control of heliostat tracking requires complicated and onerous devices. Thus, methods used to adjust quickly the whole field of a plant are essential for the rise of solar tower technology with a huge number of heliostats. Wavefront detection is widely use in adaptive optics and shape error reconstruction. Such systems can be sources of inspiration for the measurement of solar facets misalignment and tracking errors. We propose a new method of heliostat characterization inspired by adaptive optics devices. This method aims at observing the brightness distributions on heliostat's surface, from different points of view close to the receiver of the power plant, in order to calculate the wavefront of the reflection of the sun on the concentrated surface to determine its errors. The originality of this new method is to use the profile of the sun to determine the defects of the mirrors. In addition, this method would be easy to set-up and could be implemented without sophisticated apparatus: only four cameras would be used to perform the acquisitions.

The backward ray tracing with effective solar brightness used to simulate the concentrated flux map of a solar tower concentrator

NASA Astrophysics Data System (ADS)

Guo, Minghuan; Sun, Feihu; Wang, Zhifeng

2017-06-01

The solar tower concentrator is mainly composed of the central receiver on the tower top and the heliostat field around the tower. The optical efficiencies of a solar tower concentrator are important to the whole thermal performance of the solar tower collector, and the aperture plane of a cavity receiver or the (inner or external) absorbing surface of any central receiver is a key interface of energy flux. So it is necessary to simulate and analyze the concentrated time-changing solar flux density distributions on the flat or curved receiving surface of the collector, with main optical errors considered. The transient concentrated solar flux on the receiving surface is the superimposition of the flux density distributions of all the normal working heliostats in the field. In this paper, we will mainly introduce a new backward ray tracing (BRT) method combined with the lumped effective solar cone, to simulate the flux density map on the receiving-surface. For BRT, bundles of rays are launched at the receiving-surface points of interest, strike directly on the valid cell centers among the uniformly sampled mirror cell centers in the mirror surface of the heliostats, and then direct to the effective solar cone around the incident sun beam direction after reflection. All the optical errors are convoluted into the effective solar cone. The brightness distribution of the effective solar cone is here supposed to be circular Gaussian type. The mirror curvature can be adequately formulated by certain number of local normal vectors at the mirror cell centers of a heliostat. The shading & blocking mirror region of a heliostat by neighbor heliostats and also the solar tower shading on the heliostat mirror are all computed on the flat-ground-plane platform, i.e., projecting the mirror contours and the envelope cylinder of the tower onto the horizontal ground plane along the sun-beam incident direction or along the reflection directions. If the shading projection of a sampled mirror point of the current heliostat is inside the shade cast of a neighbor heliostat or in the shade cast of the tower, this mirror point should be shaded from the incident sun beam. A code based on this new ray tracing method for the 1MW Badaling solar tower power plant in Beijing has been developed using MATLAB. There are 100 azimuth-elevation tracking heliostats in the solar field and the total tower is 118 meters high. The mirror surface of the heliostats is 10m wide and 10m long, it is composed of 8 rows × 8 columns of square mirror facets and each mirror facet has the size of 1.25m×1.25m. This code also was verified by two sets of sun-beam concentrating experiments of the heliostat field on the June 14, 2015. One set of optical experiments were conducted between some typical heliostats to verify the shading & blocking computation of the code, since shading & blocking computation is the most complicated, time-consuming and important optical computing section of the code. The other set of solar concentrating tests were carried out on the field center heliostat (No. 78) to verify the simulated the solar flux images on the white target region of the northern wall of the tower. The target center is 74.5 m high to the ground plane.

Tracking formulas and strategies for a receiver oriented dual-axis tracking toroidal heliostat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, Minghuan; Wang, Zhifeng; Liang, Wenfeng

2010-06-15

A 4 m x 4 m toroidal heliostat with receiver oriented dual-axis tracking, also called spinning-elevation tracking, was developed as an auxiliary heat source for a hydrogen production system. A series of spinning-elevation tracking formulas have been derived for this heliostat. This included basic tracking formulas, a formula for the elevation angle for heliostat with a mirror-pivot offset, and a more general formula for the biased elevation angle. This paper presents the new tracking formulas in detail and analyzes the accuracy of applying a simplifying approximation. The numerical results show these receiver oriented dual-axis tracking formula approximations are accurate tomore » within 2.5 x 10{sup -6} m in image plane. Some practical tracking strategies are discussed briefly. Solar images from the toroidal heliostat at selected times are also presented. (author)« less

Cost analysis of a mini-facet heliostat

NASA Astrophysics Data System (ADS)

Hall, Colin; Pratt, Rodney; Farrant, David; Corsi, Clotilde; Pye, John; Coventry, Joe

2017-06-01

A significant problem with conventional heliostats is off-axis astigmatism, which increases the spot size at the central receiver, limiting the temperature and efficiency of solar thermal systems. Inspired by low-cost mini-actuators used for car wing mirrors, we examine the economic feasibility of a heliostat with individually adjustable mini-facets to correct astigmatic effects, and we compare three alternative tracking configurations.

State-of-the-Art Review of Low-Cost Collector Technologies

DTIC Science & Technology

1981-06-01

Mobility Low-Cost Parabolic Trough Survivability Light-Weight Thin-Film Reliability Heliostats Polymers Military 20. ABSTRACT (Contine an revers. deo It... heliostats and parabolic dish collectors. In addition several criteria were evaluated with respect to low-cost collector technologies These included...has produced collectors which incorporate sophisticated materials, = Heliostat heavy components, expensive seals and compli- o- (Point Focus) cated

Optimization of nonimaging focusing heliostat in dynamic correction of astigmatism for a wide range of incident angles.

PubMed

Chong, Kok-Keong

2010-05-15

To overcome astigmatism has always been a great challenge in designing a heliostat capable of focusing the sunlight on a small receiver throughout the year. In this Letter, a nonimaging focusing heliostat with a dynamic adjustment of facet mirrors in a group manner has been analyzed for optimizing the astigmatic correction in a wide range of incident angles. This what is to the author's knowledge a new heliostat is not only designed to serve the purpose of concentrating sunlight to several hundreds of suns, but also to significantly reduce the variation of the solar flux distribution with the incident angle.

Tower Illuminance Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ho, Clifford K.; Sims, Cianan

TIM is a real-time interactive concentrating solar field simulation. TIM models a concentrating tower (receiver), heliostat field, and potential reflected glare based on user-specified parameters such as field capacity, tower height and location. TIM provides a navigable 3D interface, allowing the user to “fly” around the field to determine the potential glare hazard from off-target heliostats. Various heliostat aiming strategies are available for specifying how heliostats behave when in standby mode. Strategies include annulus, point-per-group, up-aiming and single-point-focus. Additionally, TIM includes an avian path feature for approximating the irradiance and feather temperature of a bird flying through the field airspace.

Tracking and shape errors measurement of concentrating heliostats

NASA Astrophysics Data System (ADS)

Coquand, Mathieu; Caliot, Cyril; Hénault, François

2017-09-01

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

Simulation and Evaluation of Small Scale Solar Power Tower Performance under Malaysia Weather Conditions

NASA Astrophysics Data System (ADS)

Gamil, A. M.; Gilani, S. I.; Al-Kayiem, H. H.

2013-06-01

Solar energy is the most available, clean, and inexpensive source of energy among the other renewable sources of energy. Malaysia is an encouraging location for the development of solar energy systems due to abundant sunshine (10 hours daily with average solar energy received between 1400 and 1900 kWh/m2). In this paper the design of heliostat field of 3 dual-axis heliostat units located in Ipoh, Malaysia is introduced. A mathematical model was developed to estimate the sun position and calculate the cosine losses in the field. The study includes calculating the incident solar power to a fixed target on the tower by analysing the tower height and ground distance between the heliostat and the tower base. The cosine efficiency was found for each heliostat according to the sun movement. TRNSYS software was used to simulate the cosine efficiencies and field hourly incident solar power input to the fixed target. The results show the heliostat field parameters and the total incident solar input to the receiver.

Thermal Simulation Facilities Handbook.

DTIC Science & Technology

1983-02-01

tower provide incident radiation angles of 900 or less. Since each heliostat Is Individually controlled, the size of a test Item depends on application...designed such that it can be used for many other applications. (See also Section 3.) The solar furnace uses both a flat mirror ( heliostat ) that track...type solar thermal facility. It consists of four main components: (1) heliostat , (2) attenua- tor, (3) concentrator, and (4) test and control chamber

Simon Newcomb, America’s First Great Astronomer

DTIC Science & Technology

2009-02-01

1874 and 1882 transits of Venus across the Sun. A heliostat tracked the Sun and reflected its light through a fixed telescope, where the image was...a new and unique camera consisting of a heliostat , long-focal-length telescope, and photographic plate assembly5 (see figures 2 and 3). While the...and relays or solenoids qualified as leading- Remote mirror Objective lenses Rotating mirrorFixed mirror Observer’s eyepiece Adjustable slit Heliostat

Planning Thermal Radiation Experiments at High Flux.

DTIC Science & Technology

1981-10-27

pattern of the CNRS furnace focal spot of the energy from various heliostats (or corresponding sectors of the parabola). The focal spot had been mapped...Figure A3.2) and it could be assumed that most of the spread beyond the central area came from the peripheral heliostats , due to their acute angles...some of the heliostats . Other field data reduction would be desirable to confirm that reasonable results were being obtained. For most

Comparison-based optical study on a point-line-coupling-focus system with linear Fresnel heliostats.

PubMed

Dai, Yanjun; Li, Xian; Zhou, Lingyu; Ma, Xuan; Wang, Ruzhu

2016-05-16

Concentrating the concept of a beam-down solar tower with linear Fresnel heliostat (PLCF) is one of the feasible choices and has great potential in reducing spot size and improving optical efficiency. Optical characteristics of a PLCF system with the hyperboloid reflector are introduced and investigated theoretically. Taking into account solar position and optical surface errors, a Monte Carlo ray-tracing (MCRT) analysis model for a PLCF system is developed and applied in a comparison-based study on the optical performance between the PLCF system and the conventional beam-down solar tower system with flat and spherical heliostats. The optimal square facet of linear Fresnel heliostat is also proposed for matching with the 3D-CPC receiver.

Precise low cost chain gears for heliostats

NASA Astrophysics Data System (ADS)

Liedke, Phillip; Lewandowski, Arkadiusz; Pfahl, Andreas; Hölle, Erwin

2016-05-01

This work investigates the potential of chain gears as precise and low cost driving systems for rim drive heliostats. After explaining chain gear basics the polygon effect and chain lengthening are investigated. The polygon effect could be measured by a heliostat with chain rim gear and the chain lengthening with an accordant test set up. Two gear stages are scope of this work: a rim gear and an intermediate gear. Dimensioning, pretensioning and designing for both stages are explained.

Heliostat cost reduction study.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Scott A.; Lumia, Ronald.; Davenport, Roger

2007-06-01

Power towers are capable of producing solar-generated electricity and hydrogen on a large scale. Heliostats are the most important cost element of a solar power tower plant. Since they constitute {approx} 50% of the capital cost of the plant it is important to reduce heliostat cost as much as possible to improve the economic performance of power towers. In this study we evaluate current heliostat technology and estimate a price ofmore » $$126/m{sup 2} given year-2006 materials and labor costs for a deployment of {approx}600 MW of power towers per year. This 2006 price yields electricity at $$0.067/kWh and hydrogen at $3.20/kg. We propose research and development that should ultimately lead to a price as low as $$90/m{sup 2}, which equates to $$0.056/kWh and $2.75/kg H{sup 2}. Approximately 30 heliostat and manufacturing experts from the United States, Europe, and Australia contributed to the content of this report during two separate workshops conducted at the National Solar Thermal Test Facility.« less

Solar receiver heliostat reflector having a linear drive and position information system

DOEpatents

Horton, Richard H.

1980-01-01

A heliostat for a solar receiver system comprises an improved drive and control system for the heliostat reflector assembly. The heliostat reflector assembly 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., heat receiver, which forms part of a solar energy utilization system, such as a solar energy fueled electrical power generation system. The improved drive system includes linear stepping motors which comprise low weight, low cost, electronic pulse driven components. One embodiment comprises linear stepping motors controlled by a programmed, electronic microprocessor. Another embodiment comprises a tape driven system controlled by a position control magnetic tape.

Experiment Determination of the Velocity of Light

DTIC Science & Technology

2004-03-28

and raised so that the line along which the light traveled was about 11 feet above the ground. A heliostat at H reflected the sun’s rays through...the slit at S to the revolving mirror R, thence through a hole in the shutter, through the lens, and to the distant mirror. THE HELIOSTAT . The... heliostat was one kindly furnished by Dr. Woodward, of the Army Medical Museum, and was a modification of Foucault’s form, designed by Keith. It was found

A 200kW central receiver CPV system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lasich, John, E-mail: jbl@raygen.com; Thomas, Ian, E-mail: ithomas@raygen.com; Hertaeg, Wolfgang

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.

Concentrating Solar Power Projects - Planta Solar 10 | Concentrating Solar

Science.gov Websites

under a purely commercial approach. PS10's technologies-including glass-metal heliostats, pressurized Manufacturer (Model): Abengoa (Solucar 120) Heliostat Description: Glass-metal Tower Height: 115 m Receiver

Numerical investigation of wind loads on an operating heliostat

NASA Astrophysics Data System (ADS)

Ghanadi, Farzin; Yu, Jeremy; Emes, Matthew; Arjomandi, Maziar; Kelso, Richard

2017-06-01

The velocity fluctuations within the atmospheric boundary layer (ABL) and the wind direction are two important parameters which affect the resulting loads on the heliostats. In this study, the drag force on a square heliostat within the ABL at different turbulence intensities is simulated. To this end, numerical analysis of the wind loads have been conducted by implementing the three-dimensional Embedded Large Eddy Simulation (ELES). The results prove that in contrast with other models which are too dissipative for highly turbulent flow, the present model can accurately predict boundary effects and calculate the peak loads on heliostat at different elevation angles and turbulence intensities. Therefore, it is recommended that the model is used as a tool to provide new information about the relationship between wind loads and turbulence structures within ABL such as vortex length scale.

One-point fitting of the flux density produced by a heliostat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Collado, Francisco J.

Accurate and simple models for the flux density reflected by an isolated heliostat should be one of the basic tools for the design and optimization of solar power tower systems. In this work, the ability and the accuracy of the Universidad de Zaragoza (UNIZAR) and the DLR (HFCAL) flux density models to fit actual energetic spots are checked against heliostat energetic images measured at Plataforma Solar de Almeria (PSA). Both the fully analytic models are able to acceptably fit the spot with only one-point fitting, i.e., the measured maximum flux. As a practical validation of this one-point fitting, the interceptmore » percentage of the measured images, i.e., the percentage of the energetic spot sent by the heliostat that gets the receiver surface, is compared with the intercept calculated through the UNIZAR and HFCAL models. As main conclusions, the UNIZAR and the HFCAL models could be quite appropriate tools for the design and optimization, provided the energetic images from the heliostats to be used in the collector field were previously analyzed. Also note that the HFCAL model is much simpler and slightly more accurate than the UNIZAR model. (author)« less

Optical performance considerations for analysis and simulation of power tower plants

NASA Astrophysics Data System (ADS)

Pidaparthi, Arvind; Landman, Willem; Hoffmann, Jaap; Dinter, Frank

2017-06-01

South Africa has implemented a `time of day' tariff structure for concentrating solar power plants in the Renewable Energy Independent Power Producer Procurement Programme. It is hypothesised that payment allocation factors for the `time of day' and the `time of use' dispatch schedule influence the optimal heliostat field layout. SolarPILOT software is used to generate and optimize the heliostat field layout of a 100 MWe power tower plant in Upington, South Africa with 8 hours of thermal energy storage in the SunShot scenario with a high receiver thermal efficiency of 90%. A large size heliostat with a total area of 115.56 m2 and an external cylindrical receiver are considered for the heliostat field layout. A subset of 12 days is simulated on an hourly basis to achieve convergence and to take seasonal, daily and hourly weather variability into account. During the optimization of a heliostat field layout, the heliostats are ranked and selected according to a performance metric. In this study, two field layouts are compared based on two different performance metrics, namely: power delivered to the receiver and the time of use weighted power. The optical performance is simulated using both the Hermite (analytical) and the Monte-Carlo Ray-Tracing methods. By accounting for the TOU weighted power, it is found that the LCOE increases from 0.1831 /kWh to 0.1870 /kWh using the Hermite (analytical) method. Similarly, when MCRT techniques are used for the optical characterization, the LCOE value increases from 0.1781 /kWh to 0.1832 /kWh. It is recommended that payment allocation factors and the tariff structure for the time of day be included when comparing field layouts with other layout generation and optimization strategies. This study will be useful for power tower developers in identifying practices to be included in the optical characterization of their heliostat field layouts for better simulation results.

Optimizing heliostat positions with local search metaheuristics using a ray tracing optical model

NASA Astrophysics Data System (ADS)

Reinholz, Andreas; Husenbeth, Christof; Schwarzbözl, Peter; Buck, Reiner

2017-06-01

The life cycle costs of solar tower power plants are mainly determined by the investment costs of its construction. Significant parts of these investment costs are used for the heliostat field. Therefore, an optimized placement of the heliostats gaining the maximal annual power production has a direct impact on the life cycle costs revenue ratio. We present a two level local search method implemented in MATLAB utilizing the Monte Carlo raytracing software STRAL [1] for the evaluation of the annual power output for a specific weighted annual time scheme. The algorithm was applied to a solar tower power plant (PS10) with 624 heliostats. Compared to former work of Buck [2], we were able to improve both runtime of the algorithm and quality of the output solutions significantly. Using the same environment for both algorithms, we were able to reach Buck's best solution with a speed up factor of about 20.

Near- and far-field infrasound monitoring in the Mediterranean area

NASA Astrophysics Data System (ADS)

Campus, Paola; Marchetti, Emanuele; Le Pichon, Alexis; Wallenstein, Nicolau; Ripepe, Maurizio; Kallel, Mohamed; Mialle, Pierrick

2013-04-01

The Mediterranean area is characterized by a number of very interesting sources of infrasound signals and offers a promising playground for the development of a deeper understanding of such sources and of the associated propagation models. The progress in the construction and certification of infrasound arrays belonging to the International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) in the vicinity of this area has been complemented, in the last decade, by the construction of infrasound arrays established by several European research groups. The University of Florence (UniFi) plays a crucial role for the detection of infrasound signals in the Mediterranean area, having deployed since several years two infrasound arrays on Stromboli and Etna volcanoes, and, more recently, three infrasound arrays in the Alpine area of NW Italy and one infrasound array on the Apennines (Mount Amiata), designed and established in the framework of the ARISE Project. The IMS infrasound arrays IS42 (Graciosa, Azores, Portugal) and IS48 (Kesra, Tunisia) recorded, since the time of their certification, a number of far-field events which can be correlated with some near-field records of the infrasound arrays belonging to UniFi. An analysis of the results and potentialities of infrasound source's detections in near and far-field realized by IS42, IS48 and UniFi arrays in the Mediterranean area, with special focus on volcanic events is presented. The combined results deriving from the analysis of data recorded by the Unifi arrays and by the IS42 and IS48 arrays, in collaboration with the Department of Analyse et Surveillance (CEA/DASE), will generate a synergy which will certainly contribute to the progress of the ARISE Project.

System of tolerances for a solar-tower power station

NASA Astrophysics Data System (ADS)

Aparisi, R. R.; Tepliakov, D. I.

The principles underlying the establishment of a system of tolerances for a solar-tower station are presented. Attention is given to static and dynamic tolerances and deviations for a single heliostat, and geometrical tolerances for a field of heliostats.

Development of a %22solar patch%22 calculator to evaluate heliostat-field irradiance as a boundary condition in CFD models.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khalsa, Siri Sahib; Ho, Clifford Kuofei

2010-04-01

A rigorous computational fluid dynamics (CFD) approach to calculating temperature distributions, radiative and convective losses, and flow fields in a cavity receiver irradiated by a heliostat field is typically limited to the receiver domain alone for computational reasons. A CFD simulation cannot realistically yield a precise solution that includes the details within the vast domain of an entire heliostat field in addition to the detailed processes and features within a cavity receiver. Instead, the incoming field irradiance can be represented as a boundary condition on the receiver domain. This paper describes a program, the Solar Patch Calculator, written in Microsoftmore » Excel VBA to characterize multiple beams emanating from a 'solar patch' located at the aperture of a cavity receiver, in order to represent the incoming irradiance from any field of heliostats as a boundary condition on the receiver domain. This program accounts for cosine losses; receiver location; heliostat reflectivity, areas and locations; field location; time of day and day of year. This paper also describes the implementation of the boundary conditions calculated by this program into a Discrete Ordinates radiation model using Ansys{reg_sign} FLUENT (www.fluent.com), and compares the results to experimental data and to results generated by the code DELSOL.« less

Development of a %22Solar Patch%22 calculator to evaluate heliostat-field irradiance as a boundary condition in CFD models.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khalsa, Siri Sahib S.; Ho, Clifford Kuofei

2010-05-01

A rigorous computational fluid dynamics (CFD) approach to calculating temperature distributions, radiative and convective losses, and flow fields in a cavity receiver irradiated by a heliostat field is typically limited to the receiver domain alone for computational reasons. A CFD simulation cannot realistically yield a precise solution that includes the details within the vast domain of an entire heliostat field in addition to the detailed processes and features within a cavity receiver. Instead, the incoming field irradiance can be represented as a boundary condition on the receiver domain. This paper describes a program, the Solar Patch Calculator, written in Microsoftmore » Excel VBA to characterize multiple beams emanating from a 'solar patch' located at the aperture of a cavity receiver, in order to represent the incoming irradiance from any field of heliostats as a boundary condition on the receiver domain. This program accounts for cosine losses; receiver location; heliostat reflectivity, areas and locations; field location; time of day and day of year. This paper also describes the implementation of the boundary conditions calculated by this program into a Discrete Ordinates radiation model using Ansys{reg_sign} FLUENT (www.fluent.com), and compares the results to experimental data and to results generated by the code DELSOL.« less

Second generation heliostat development for solar central receiver systems. Volume 4, appendices F-J: Control software test results manufacturing pile installation pile coatings

NASA Astrophysics Data System (ADS)

1981-03-01

Support documentation for a second generation heliostat project is presented. Flowcharts of control software are included. Numerical and graphic test results are provided. Project management information is also provided.

An automated model-based aim point distribution system for solar towers

NASA Astrophysics Data System (ADS)

Schwarzbözl, Peter; Rong, Amadeus; Macke, Ansgar; Säck, Jan-Peter; Ulmer, Steffen

2016-05-01

Distribution of heliostat aim points is a major task during central receiver operation, as the flux distribution produced by the heliostats varies continuously with time. Known methods for aim point distribution are mostly based on simple aim point patterns and focus on control strategies to meet local temperature and flux limits of the receiver. Lowering the peak flux on the receiver to avoid hot spots and maximizing thermal output are obviously competing targets that call for a comprehensive optimization process. This paper presents a model-based method for online aim point optimization that includes the current heliostat field mirror quality derived through an automated deflectometric measurement process.

Optical analysis for simplified astigmatic correction of non-imaging focusing heliostat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chong, K.K.

2010-08-15

In the previous work, non-imaging focusing heliostat that consists of m x n facet mirrors can carry out continuous astigmatic correction during sun-tracking with the use of only (m + n - 2) controllers. For this paper, a simplified astigmatic correction of non-imaging focusing heliostat is proposed for reducing the number of controllers from (m + n - 2) to only two. Furthermore, a detailed optical analysis of the new proposal has been carried out and the simulated result has shown that the two-controller system can perform comparably well in astigmatic correction with a much simpler and more cost effectivemore » design. (author)« less

Optical approach to design a beam-down heliostats plant

NASA Astrophysics Data System (ADS)

Fontani, Daniela; Sansoni, Paola; Francini, Franco; Jafrancesco, David

2017-06-01

The optical design development of beam-down heliostat fields is complex and timewasting. It requires the use of an optical design software package in order to evaluate the interactions between light and surfaces and the solar divergence effects. This paper proposes a three-step procedure devoted to design a beam-down heliostat field taking into account the actual technical constraints; in particular, the shaping of the field starts from the request to have a sufficient uniformity irradiance on the internal surfaces of the receiver. The procedure is applied to an effective field simulation in order to allow a better understanding of its different phases.

Tailored edge-ray concentrators as ideal second stages for Fresnel reflectors.

PubMed

Gordon, J M; Ries, H

1993-05-01

For both linear and point-focus Fresnel reflectors, we present a new type of ideal nonimaging secondary concentrator, the tailored edge-ray concentrator, that can closely approach the thermodynamic limit of concentration. For large rim-angle heliostat fields, practical-sized secondaries with shapes that should be relatively easy to fabricate can achieve concentrations substantially above those of compound parabolic concentrators. This superiority stems from designing so as to accommodate the particular flux from the heliostat field. The edge-ray principle used for generating the new secondary dictates a heliostat tracking strategy that is different from the conventional one but is equally easy to implement.

A Survey of Permanently-Manned Lunar Base Concepts

DTIC Science & Technology

1989-06-01

of warmth and illumination. Heliostat mirr -s direct the solar beam into a periscope-like tunnel. The shape and configuration of the reflector...the tower is continuously oriented toward the sun. Installed on the tower are heliostat mirrors for a solar furnace, a cylindrical collector for lower

Improving solar-pumped laser efficiency by a ring-array concentrator

NASA Astrophysics Data System (ADS)

Tibúrcio, Bruno D.; Liang, Dawei; Almeida, Joana; Matos, Rodrigo; Vistas, Cláudia R.

2018-01-01

We report here a compact pumping scheme for achieving large improvement in collection and conversion efficiency of a Nd:YAG solar-pumped laser by an innovative ring-array solar concentrator. An aspheric fused silica lens was used to further concentrate the solar radiation from the focal region of the 1.5-m-diameter ring-array concentrator to a 5.0-mm-diameter, 20-mm-length Nd:YAG single-crystal rod within a conical-shaped pump cavity, enabling multipass pumping to the laser rod. 67.3-W continuous-wave solar laser power was numerically calculated, corresponding to 38.2-W / m2 solar laser collection efficiency, being 1.22 and 1.27 times more than the state-of-the-art records by both heliostat-parabolic mirror and Fresnel lens solar laser systems, respectively. 4.0% conversion efficiency and 0.021-W brightness figure of merit were also numerically obtained, corresponding to 1.25 and 1.62 times enhancement over the previous records, respectively. The influence of tracking error on solar laser output power was also analyzed.

Highly efficient end-side-pumped Nd:YAG solar laser by a heliostat-parabolic mirror system.

PubMed

Almeida, J; Liang, D; Vistas, C R; Guillot, E

2015-03-10

We report a large improvement in the collection and slope efficiency of an Nd:YAG solar laser pumped by a heliostat-parabolic mirror system. A conical fused silica lens was used to further concentrate the solar radiation from the focal zone of a 2 m diameter primary concentrator to a Nd:YAG single-crystal rod within a conical pump cavity, which enabled multipass pumping to the active medium. A 56 W cw laser power was measured, corresponding to 21.1  W/m2 record-high solar laser collection efficiency with the heliostat-parabolic mirror system. 4.9% slope efficiency was calculated, corresponding to 175% enhancement over our previous result.

A unified approach to VLSI layout automation and algorithm mapping on processor arrays

NASA Technical Reports Server (NTRS)

Venkateswaran, N.; Pattabiraman, S.; Srinivasan, Vinoo N.

1993-01-01

Development of software tools for designing supercomputing systems is highly complex and cost ineffective. To tackle this a special purpose PAcube silicon compiler which integrates different design levels from cell to processor arrays has been proposed. As a part of this, we present in this paper a novel methodology which unifies the problems of Layout Automation and Algorithm Mapping.

Wind loading on solar concentrators: Some general considerations

NASA Technical Reports Server (NTRS)

Roschke, E. J.

1984-01-01

A survey was completed to examine the problems and complications arising from wind loading on solar concentrators. Wind loading is site specific and has an important bearing on the design, cost, performance, operation and maintenance, safety, survival, and replacement of solar collecting systems. Emphasis herein is on paraboloidal, two-axis tracking systems. Thermal receiver problems also are discussed. Wind characteristics are discussed from a general point of view. Current methods for determining design wind speed are reviewed. Aerodynamic coefficients are defined and illustrative examples are presented. Wind tunnel testing is discussed, and environmental wind tunnels are reviewed. Recent results on heliostat arrays are reviewed as well. Aeroelasticity in relation to structural design is discussed briefly.

Concentrated solar-flux measurements at the IEA-SSPS solar-central-receiver power plant, Tabernas - Lameria (Spain)

NASA Astrophysics Data System (ADS)

Vontobel, G.; Schelders, C.; Real, M.

A flux analyzing system (F.A.S.) was installed at the central receiver system of the SSPS project to determine the relative flux distribution of the heliostat field and to measure the entire optical solar flux reflected from the heliostat field into the receiver cavity. The functional principles of the F.A.S. are described. The raw data and the evaluation of the measurements of the entire helistat field are given, and an approach to determine the actual fluxes which hit the receiver tube bundle is presented. A method is described to qualify the performance of each heliostat using a computer code. The data of the measurements of the direct radiation are presented.

Apparatus for solar coal gasification

DOEpatents

Gregg, D.W.

1980-08-04

Apparatus for using focused solar radiation to gasify coal and other carbonaceous materials is described. Incident solar radiation is focused from an array of heliostats through a window onto the surface of a moving bed of coal, contained within a gasification reactor. The reactor is designed to minimize contact between the window and solids in the reactor. Steam introduced into the gasification reactor reacts with the heated coal to produce gas consisting mainly of carbon monoxide and hydrogen, commonly called synthesis gas, which can be converted to methane, methanol, gasoline, and other useful products. One of the novel features of the invention is the generation of process steam in one embodiment at the rear surface of a secondary mirror used to redirect the focused sunlight. Another novel feature of the invention is the location and arrangement of the array of mirrors on an inclined surface (e.g., a hillside) to provide for direct optical communication of said mirrors and the carbonaceous feed without a secondary redirecting mirror.

High Temperature Solar Electrothermal Processing-III. Zinc from Zinc Oxide at 1200-1675K Using a Non-Consumable Anode.

DTIC Science & Technology

1987-09-09

and the flow of Ar, about 5 1/min, begun. The heliostat was set to track with the doors closed. The instrumentation was activated. Then both furnace...experiment, we closed both doors, stowed the heliostat and reopened the doors to provide good ventilation to the concentrator room. Then we disconnected the

Design of a Heliostat for Centro de Investigaciones de Astronomía (CIDA)

NASA Astrophysics Data System (ADS)

Dávila, L. E.; Barboza, S. J.; Sánchez, G. A.; Della Prugna, F.; Cova, J.; Provenzano, S. E.; Chacón, R. D.

2009-05-01

This paper explains the procedure used in the design of a heliostat to be installed at the headquarters of the Centro de Investigaciones de Astronomía, located in the city of Mérida, Venezuela. The heliostat will be used mainly for educational and public outreach programs, so the design specifications did not require compensation for rotation of the Sun's image at the focal point. The engineering computational tools CAD-CAE were used in order to allow a seamless interaction between the two disciplines involved, Mechanical Engineering and Astronomy. It has also been taken into consideration, as a starting requirement, that all materials be easily available and that all parts, excluding the optics, could be manufactured with the equipment available at the CIDA workshop. These considerations were intended to reduce the cost of the device and to increase the feasibility of construction with limited technological facilities and financial resources. The results obtained by means of the computing tools used were validated through comparison against the analytical calculations. As a result, a robust but low cost heliostat was designed which in the near future will be used to project the Sun's image on a screen for public viewing and student research projects.

Advanced structural optimization of a heliostat with cantilever arms

NASA Astrophysics Data System (ADS)

Bogdanov, Dimitar; Zlatanov, Hristo

2016-05-01

The weight of the support structure of heliostats, CPV and PV trackers is important cost element of a solar plant and reducing it will improve the economic viability of a solar project. Heliostats with rectangular area (1 to 5 in 1 m² steps; 5 to 150 in 5 m² steps) and aspect ratios (0.5, 1.0, 1.2, 1.5, 2.0) were investigated under various winds speeds (0, 5 to 100 in 5 m/s steps), wind direction (0 to 180° in 15° steps) and elevation positions (0 to 90° in 10° steps). Each load case was run with three different cantilever arms. The inclination angle of the chords and bracings was chosen so as to fulfill the geometrical boundary condition. Stress and buckling validations were performed according to Eurocode. The results of research carried out can be used to determine the specific weight of a heliostat in kg/m² as a function of the wind speed, tracker area and tracker aspect ratio. Future work should investigate the impact of using cold formed structural hollow sections and cross sections with thinner wall thickness which is not part of EN 10210.

Life Cycle Environmental Impacts Resulting from the Manufacture of the Heliostat Field for a Reference Power Tower Design in the United States: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heath, G.; Burkhardt, J.; Turchi, C.

2012-10-01

Life cycle assessment (LCA) is recognized as a useful analytical approach for quantifying environmental impacts of renewable energy technologies, including concentrating solar power (CSP). An LCA accounts for impacts from all stages in the development, operation, and decommissioning of a CSP plant, including such upstream stages as the extraction of raw materials used in system components, manufacturing of those components, and construction of the plant. The National Renewable Energy Laboratory is conducting a series of LCA studies for various CSP technologies. This paper contributes to a thorough LCA of a 100 MWnet molten salt power tower CSP plant by estimatingmore » the environmental impacts resulting from the manufacture of heliostats. Three life cycle metrics are evaluated: greenhouse gas emissions, water consumption, and cumulative energy demand. The heliostat under consideration (the 148 m2 Advanced Thermal Systems heliostat) emits 5,300 kg CO2eq, consumes 274 m3 of water, and requires 159,000 MJeq during its manufacture. Future work will incorporate the results from this study into the LCA model used to estimate the life cycle impacts of the entire 100 MWnet power tower CSP plant.« less

Area utilization efficiency of a sloping heliostat system for solar concentration.

PubMed

Wei, L Y

1983-02-15

Area utilization efficiency (AUE) is formulated for a sloping heliostat system facing any direction. The effects of slope shading, incidence factor, sun shading, and tower blocking by the mirrors are all taken into account. Our results show that annually averaged AUEs calculated for heliostat systems (1) increase with tower height at low slope angles but less rapidly at high slopes, (2) increase monotonically with slope angle and saturate at large slopes for systems facing due south, (3) reach a maximum at a certain slope for systems facing other directions than due south, and (4) drop sharply at slopes greater than a certain value for systems facing due east or west due to slope shading effect. The results are useful for solar energy collection on nonflat terrains.

Sun sensor boresight alignment testing for the Halogen Occultation Experiment

NASA Technical Reports Server (NTRS)

Moore, A. S.; Laney, V. S.; Mauldin, L. E., III

1987-01-01

The boresight alignment testing for the sun sensor assembly on the Halogen Occultation Experiment (HALOE) is described. The sun sensor assembly consists of three sensors that provide feedback signals for controlling dual axes gimbals. Two energy balancing silicon detectors are operated as wideband sensors in the azimuth and elevation axes. The third sensor is a silicon photodiode array operated as a narrow-band sensor in the elevation axis. These sensors are mounted on a common Invar structure which is mounted to the HALOE telescope. A blackbody was used as the stimulating source to perform the initial boresight alignment and this was checked with a heliostat solar look and a direct solar look. These tests are explained with a comparison between each source used.

Optical study of solar tower power plants

NASA Astrophysics Data System (ADS)

Eddhibi, F.; Ben Amara, M.; Balghouthi, M.; Guizani, A.

2015-04-01

The central receiver technology for electricity generation consists of concentrating solar radiation coming from the solar tracker field into a central receiver surface located on the top of the tower. The heliostat field is constituted of a big number of reflective mirrors; each heliostat tracks the sun individually and reflects the sunlight to a focal point. Therefore, the heliostat should be positioned with high precision in order to minimize optical losses. In the current work, a mathematical model for the analysis of the optical efficiency of solar tower field power plant is proposed. The impact of the different factors which influence the optical efficiency is analyzed. These parameters are mainly, the shading and blocking losses, the cosine effect, the atmospheric attenuation and the spillage losses. A new method for the calculation of blocking and shadowing efficiency is introduced and validated by open literature.

A novel VLSI processor architecture for supercomputing arrays

NASA Technical Reports Server (NTRS)

Venkateswaran, N.; Pattabiraman, S.; Devanathan, R.; Ahmed, Ashaf; Venkataraman, S.; Ganesh, N.

1993-01-01

Design of the processor element for general purpose massively parallel supercomputing arrays is highly complex and cost ineffective. To overcome this, the architecture and organization of the functional units of the processor element should be such as to suit the diverse computational structures and simplify mapping of complex communication structures of different classes of algorithms. This demands that the computation and communication structures of different class of algorithms be unified. While unifying the different communication structures is a difficult process, analysis of a wide class of algorithms reveals that their computation structures can be expressed in terms of basic IP,IP,OP,CM,R,SM, and MAA operations. The execution of these operations is unified on the PAcube macro-cell array. Based on this PAcube macro-cell array, we present a novel processor element called the GIPOP processor, which has dedicated functional units to perform the above operations. The architecture and organization of these functional units are such to satisfy the two important criteria mentioned above. The structure of the macro-cell and the unification process has led to a very regular and simpler design of the GIPOP processor. The production cost of the GIPOP processor is drastically reduced as it is designed on high performance mask programmable PAcube arrays.

Final Technical Progress Report: Development of Low-Cost Suspension Heliostat; December 7, 2011 - December 6, 2012

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bender, W.

2013-01-01

Final technical progress report of SunShot Incubator Solaflect Energy. The project succeeded in demonstrating that the Solaflect Suspension Heliostat design is viable for large-scale CSP installations. Canting accuracy is acceptable and is continually improving as Solaflect improves its understanding of this design. Cost reduction initiatives were successful, and there are still many opportunities for further development and further cost reduction.

Transmittance Measurement of a Heliostat Facility used in the Preflight Radiometric Calibration of Earth-Observing Sensors

NASA Technical Reports Server (NTRS)

Czapla-Myers, J.; Thome, K.; Anderson, N.; McCorkel, J.; Leisso, N.; Good, W.; Collins, S.

2009-01-01

Ball Aerospace and Technologies Corporation in Boulder, Colorado, has developed a heliostat facility that will be used to determine the preflight radiometric calibration of Earth-observing sensors that operate in the solar-reflective regime. While automatically tracking the Sun, the heliostat directs the solar beam inside a thermal vacuum chamber, where the sensor under test resides. The main advantage to using the Sun as the illumination source for preflight radiometric calibration is because it will also be the source of illumination when the sensor is in flight. This minimizes errors in the pre- and post-launch calibration due to spectral mismatches. It also allows the instrument under test to operate at irradiance values similar to those on orbit. The Remote Sensing Group at the University of Arizona measured the transmittance of the heliostat facility using three methods, the first of which is a relative measurement made using a hyperspectral portable spectroradiometer and well-calibrated reference panel. The second method is also a relative measurement, and uses a 12-channel automated solar radiometer. The final method is an absolute measurement using a hyperspectral spectroradiometer and reference panel combination, where the spectroradiometer is calibrated on site using a solar-radiation-based calibration.

Improved heliostat field design for solar tower plants

NASA Astrophysics Data System (ADS)

Collado, Francisco J.; Guallar, Jesús

2017-06-01

In solar power tower (SPT) systems, selecting the optimum location of thousands of heliostats and the most profitable tower height and receiver size remains a challenge. Campo code is prepared for the detailed design of such plants in particular, the optimum layout, provided that the plant size is known. Therefore, less exhaustive codes, as DELSOL3, are also needed to perform preliminary parametric analysis that narrows the most economic size of the plant.

Apparatus and method for solar coal gasification

DOEpatents

Gregg, David W.

1980-01-01

Apparatus for using focused solar radiation to gasify coal and other carbonaceous materials. Incident solar radiation is focused from an array of heliostats onto a tower-mounted secondary mirror which redirects the focused solar radiation down through a window onto the surface of a vertically-moving bed of coal, or a fluidized bed of coal, contained within a gasification reactor. The reactor is designed to minimize contact between the window and solids in the reactor. Steam introduced into the gasification reactor reacts with the heated coal to produce gas consisting mainly of carbon monoxide and hydrogen, commonly called "synthesis gas", which can be converted to methane, methanol, gasoline, and other useful products. One of the novel features of the invention is the generation of process steam at the rear surface of the secondary mirror.

Apparatus for solar coal gasification

DOEpatents

Gregg, D.W.

Apparatus for using focused solar radiation to gasify coal and other carbonaceous materials is described. Incident solar radiation is focused from an array of heliostats onto a tower-mounted secondary mirror which redirects the focused solar radiation down through a window onto the surface of a vertically-moving bed of coal, or a fluidized bed of coal, contained within a gasification reactor. The reactor is designed to minimize contact between the window and solids in the reactor. Steam introduced into the gasification reactor reacts with the heated coal to produce gas consisting mainly of carbon monoxide and hydrogen, commonly called synthesis gas, which can be converted to methane, methanol, gasoline, and other useful products. One of the novel features of the invention is the generation of process steam at the rear surface of the secondary mirror.

Evaluation of Heliostat Standby Aiming Strategies to Reduce Avian Flux Hazards and Impacts on Operational Performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wendelin, Timothy J; Ho, Clifford K.; Horstman, Luke

This paper presents a study of alternative heliostat standby aiming strategies and their impact on avian flux hazards and operational performance of a concentrating solar power plant. A mathematical model was developed that predicts the bird-feather temperature as a function of solar irradiance, thermal emittance, convection, and thermal properties of the feather. The irradiance distribution in the airspace above the Ivanpah Unit 2 heliostat field was simulated using a ray-trace model for two different times of the day, four days of the year, and nine different standby aiming strategies. The impact of the alternative aiming strategies on operational performance wasmore » assessed by comparing the heliostat slew times from standby position to the receiver for the different aiming strategies. Increased slew times increased a proxy start-up time that reduced the simulated annual energy production. Results showed that spreading the radial aim points around the receiver to a distance of ~150 m or greater reduced the hazardous exposure times that the feather temperature exceeded the hazard metric of 160 degrees C. The hazardous exposure times were reduced by ~23% and 90% at a radial spread of aim points extending to 150 m and 250 m, respectively, but the simulated annual energy production decreased as a result of increased slew times. Single point-focus aiming strategies were also evaluated, but these strategies increased the exposure hazard relative to other aiming strategies.« less

Aerosols attenuating the solar radiation collected by solar tower plants: The horizontal pathway at surface level

NASA Astrophysics Data System (ADS)

Elias, Thierry; Ramon, Didier; Dubus, Laurent; Bourdil, Charles; Cuevas-Agulló, Emilio; Zaidouni, Taoufik; Formenti, Paola

2016-05-01

Aerosols attenuate the solar radiation collected by solar tower plants (STP), along two pathways: 1) the atmospheric column pathway, between the top of the atmosphere and the heliostats, resulting in Direct Normal Irradiance (DNI) changes; 2) the grazing pathway close to surface level, between the heliostats and the optical receiver. The attenuation along the surface-level grazing pathway has been less studied than the aerosol impact on changes of DNI, while it becomes significant in STP of 100 MW or more. Indeed aerosols mostly lay within the surface atmospheric layer, called the boundary layer, and the attenuation increases with the distance covered by the solar radiation in the boundary layer. In STP of 100 MW or more, the distance between the heliostats and the optical receiver becomes large enough to produce a significant attenuation by aerosols. We used measured aerosol optical thickness and computed boundary layer height to estimate the attenuation of the solar radiation at surface level at Ouarzazate (Morocco). High variabilities in aerosol amount and in vertical layering generated a significant magnitude in the annual cycle and significant inter-annual changes. Indeed the annual mean of the attenuation caused by aerosols over a 1-km heliostat-receiver distance was 3.7% in 2013, and 5.4% in 2014 because of a longest desert dust season. The monthly minimum attenuation of less than 3% was observed in winter and the maximum of more than 7% was observed in summer.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Easton, C. R.

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 optimizationmore » is included. (WHK)« less

ArrayNinja: An Open Source Platform for Unified Planning and Analysis of Microarray Experiments.

PubMed

Dickson, B M; Cornett, E M; Ramjan, Z; Rothbart, S B

2016-01-01

Microarray-based proteomic platforms have emerged as valuable tools for studying various aspects of protein function, particularly in the field of chromatin biochemistry. Microarray technology itself is largely unrestricted in regard to printable material and platform design, and efficient multidimensional optimization of assay parameters requires fluidity in the design and analysis of custom print layouts. This motivates the need for streamlined software infrastructure that facilitates the combined planning and analysis of custom microarray experiments. To this end, we have developed ArrayNinja as a portable, open source, and interactive application that unifies the planning and visualization of microarray experiments and provides maximum flexibility to end users. Array experiments can be planned, stored to a private database, and merged with the imaged results for a level of data interaction and centralization that is not currently attainable with available microarray informatics tools. © 2016 Elsevier Inc. All rights reserved.

A solar-hydrogen economy for U.S.A.

NASA Astrophysics Data System (ADS)

Bockris, J. Om.; Veziroglu, T. N.

The benefits, safety, production, distribution, storage, and uses, as well as the economics of a solar and hydrogen based U.S. energy system are described. Tropical and subtropical locations for the generation plants would provide power from photovoltaics, heliostat arrays, OTEC plants, or genetically engineered algae to produce hydrogen by electrolysis, direct thermal conversion, thermochemical reactions, photolysis, or hybrid systems. Either pipelines for gas transport or supertankers for liquefied hydrogen would distribute the fuel, with storage in underground reservoirs, aquifers, and pressurized bladders at sea. The fuel would be distributed to factories, houses, gas stations, and airports. It can be used in combustion engines, gas turbines, and jet engines, and produces water vapor as an exhaust gas. The necessary research effort to define and initiate construction of technically and economically viable solar-hydrogen plants is projected to be 3 yr, while the technical definition of fusion power plants, the other nondepletable energy system, is expected to take 25 yr.

Evolution of integrated panel structural design and interfaces for PV power plants

NASA Technical Reports Server (NTRS)

Arnett, J. C.; Anderson, A. J.; Robertson, R. E.

1983-01-01

The evolution of integrated photovoltaic (PV) panel design at ARCO Solar is discussed. Historically, framed PV modules of about 1 x 4-ft size were individually mounted in the field on fixed support structures and interconnected electrically with cables to build higher-power arrays. When ARCO Solar saw the opportunity in 1982 to marry its PV modules with state-of-the-art heliostat trackers developed by ARCO Power Systems, it became obvious that mounting individual modules was impractical. For this project, the framed modules were factory-assembled into panels and interconnected with cables before being mounted on the trackers. Since then, ARCO Solar made considerable progress and gained substantial experience in the design and fabrication of large PV panels. Constraints and criteria considered in these design activities included static and dynamic loads; assembly and transportation equipment and logistics, structural and electrical interfaces, and safety and grounding concerns.

GUDM: Automatic Generation of Unified Datasets for Learning and Reasoning in Healthcare.

PubMed

Ali, Rahman; Siddiqi, Muhammad Hameed; Idris, Muhammad; Ali, Taqdir; Hussain, Shujaat; Huh, Eui-Nam; Kang, Byeong Ho; Lee, Sungyoung

2015-07-02

A wide array of biomedical data are generated and made available to healthcare experts. However, due to the diverse nature of data, it is difficult to predict outcomes from it. It is therefore necessary to combine these diverse data sources into a single unified dataset. This paper proposes a global unified data model (GUDM) to provide a global unified data structure for all data sources and generate a unified dataset by a "data modeler" tool. The proposed tool implements user-centric priority based approach which can easily resolve the problems of unified data modeling and overlapping attributes across multiple datasets. The tool is illustrated using sample diabetes mellitus data. The diverse data sources to generate the unified dataset for diabetes mellitus include clinical trial information, a social media interaction dataset and physical activity data collected using different sensors. To realize the significance of the unified dataset, we adopted a well-known rough set theory based rules creation process to create rules from the unified dataset. The evaluation of the tool on six different sets of locally created diverse datasets shows that the tool, on average, reduces 94.1% time efforts of the experts and knowledge engineer while creating unified datasets.

GUDM: Automatic Generation of Unified Datasets for Learning and Reasoning in Healthcare

PubMed Central

Ali, Rahman; Siddiqi, Muhammad Hameed; Idris, Muhammad; Ali, Taqdir; Hussain, Shujaat; Huh, Eui-Nam; Kang, Byeong Ho; Lee, Sungyoung

2015-01-01

A wide array of biomedical data are generated and made available to healthcare experts. However, due to the diverse nature of data, it is difficult to predict outcomes from it. It is therefore necessary to combine these diverse data sources into a single unified dataset. This paper proposes a global unified data model (GUDM) to provide a global unified data structure for all data sources and generate a unified dataset by a “data modeler” tool. The proposed tool implements user-centric priority based approach which can easily resolve the problems of unified data modeling and overlapping attributes across multiple datasets. The tool is illustrated using sample diabetes mellitus data. The diverse data sources to generate the unified dataset for diabetes mellitus include clinical trial information, a social media interaction dataset and physical activity data collected using different sensors. To realize the significance of the unified dataset, we adopted a well-known rough set theory based rules creation process to create rules from the unified dataset. The evaluation of the tool on six different sets of locally created diverse datasets shows that the tool, on average, reduces 94.1% time efforts of the experts and knowledge engineer while creating unified datasets. PMID:26147731

Modelling of a Solar Thermal Power Plant for Benchmarking Blackbox Optimization Solvers

NASA Astrophysics Data System (ADS)

Lemyre Garneau, Mathieu

A new family of problems is provided to serve as a benchmark for blackbox optimization solvers. The problems are single or bi-objective and vary in complexity in terms of the number of variables used (from 5 to 29), the type of variables (integer, real, category), the number of constraints (from 5 to 17) and their types (binary or continuous). In order to provide problems exhibiting dynamics that reflect real engineering challenges, they are extracted from an original numerical model of a concentrated solar power (CSP) power plant with molten salt thermal storage. The model simulates the performance of the power plant by using a high level modeling of each of its main components, namely, an heliostats field, a central cavity receiver, a molten salt heat storage, a steam generator and an idealized powerblock. The heliostats field layout is determined through a simple automatic strategy that finds the best individual positions on the field by considering their respective cosine efficiency, atmospheric scattering and spillage losses as a function of the design parameters. A Monte-Carlo integral method is used to evaluate the heliostats field's optical performance throughout the day so that shadowing effects between heliostats are considered, and the results of this evaluation provide the inputs to simulate the levels and temperatures of the thermal storage. The molten salt storage inventory is used to transfer thermal energy to the powerblock, which simulates a simple Rankine cycle with a single steam turbine. Auxiliary models are used to provide additional optimization constraints on the investment cost, parasitic losses or components failure. The results of preliminary optimizations performed with the NOMAD software using default settings are provided to show the validity of the problems.

Alignment and focus of mirrored facets of a heliosat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yellowhair, Julius E; Ho, Clifford Kuofei; Diver, Richard B

2013-11-12

Various technologies pertaining to aligning and focusing mirrored facets of a heliostat are described herein. Updating alignment and/or focus of mirrored facets is undertaken through generation of a theoretical image, wherein the theoretical image is indicative of a reflection of the target via the mirrored facets when the mirrored facets are properly aligned. This theoretical image includes reference points that are overlaid on an image of the target as reflected by the mirrored facets of the heliostat. A technician adjusts alignment/focus of a mirrored facet by causing reflected reference markings to become aligned with the reference points in the theoreticalmore » image.« less

Derivation of error sources for experimentally derived heliostat shapes

NASA Astrophysics Data System (ADS)

Cumpston, Jeff; Coventry, Joe

2017-06-01

Data gathered using photogrammetry that represents the surface and structure of a heliostat mirror panel is investigated in detail. A curve-fitting approach that allows the retrieval of four distinct mirror error components, while prioritizing the best fit possible to paraboloidal terms in the curve fitting equation, is presented. The angular errors associated with each of the four surfaces are calculated, and the relative magnitude for each of them is given. It is found that in this case, the mirror had a significant structural twist, and an estimate of the improvement to the mirror surface quality in the case of no twist was made.

Storage and computationally efficient permutations of factorized covariance and square-root information arrays

NASA Technical Reports Server (NTRS)

Muellerschoen, R. J.

1988-01-01

A unified method to permute vector stored Upper triangular Diagonal factorized covariance and vector stored upper triangular Square Root Information arrays is presented. The method involves cyclic permutation of the rows and columns of the arrays and retriangularization with fast (slow) Givens rotations (reflections). Minimal computation is performed, and a one dimensional scratch array is required. To make the method efficient for large arrays on a virtual memory machine, computations are arranged so as to avoid expensive paging faults. This method is potentially important for processing large volumes of radio metric data in the Deep Space Network.

An overview of current activities at the National Solar Thermal Test Facility

NASA Astrophysics Data System (ADS)

Cameron, C. P.; Klimas, P. C.

This paper is a description of the United States Department of Energy's National Solar Thermal Test Facility, highlighting current test programs. In the central receiver area, research underway supports commercialization of molten nitrate salt technology, including receivers, thermal energy transport, and corrosion experiments. Concentrator research includes large-area, glass-metal heliostats and stretched-membrane heliostats and dishes. Test activities in support of dish-Stirling systems with reflux receivers are described. Research on parabolic troughs includes characterization of several receiver configurations. Other test facility activities include solar detoxification experiments, design assistance testing of commercially-available solar hardware, and non-DOE-funded work, including thermal exposure tests and testing of volumetric and PV central receiver concepts.

Eurelios - The 1-MW(el) helioelectric power plant of the European Community Program

NASA Astrophysics Data System (ADS)

Borgese, D.; Dinelli, G.; Faure, J. J.; Gretz, J.; Schober, G.

1984-02-01

The Eurelios solar thermal electricity-generating plant is based on the central receiver principle. Mirror surfaces totaling 6200 sq m are mounted on 182 heliostats which reflect solar flux into a central receiver atop a 55-m high tower. Water is circulated through the receiver, which converts it to steam that in turn drives a turbine generator. A bypass is used for start-up and shut-down procedures, and a thermal buffer system has been incorporated so that the plant can continue operating without solar energy input over a period of 30 min. Attention is given to heliostat and central receiver design details and optical performance values.

Heliostat for astronomical usage

NASA Technical Reports Server (NTRS)

Heyde, G.

1979-01-01

The design of a heliostat is presented. The invention consists of a mechanical polar axis which can rotate and which is parallel to the world axis. A mirror is supported in such a way that it can be rotated arbitrarily around a declination axis which is perpendicular to it. After execution of this rotation, the mirror can be clamped in the plane of the world axis, which can be corrected and verified by special collimation directions. The clockwork or drive unit can be driven for a 24 or 48 hour complete rotation of the axis using any known device such as switchable gears, without changing its regular variation related to stellar time or mean solar time.

Read-noise characterization of focal plane array detectors via mean-variance analysis.

PubMed

Sperline, R P; Knight, A K; Gresham, C A; Koppenaal, D W; Hieftje, G M; Denton, M B

2005-11-01

Mean-variance analysis is described as a method for characterization of the read-noise and gain of focal plane array (FPA) detectors, including charge-coupled devices (CCDs), charge-injection devices (CIDs), and complementary metal-oxide-semiconductor (CMOS) multiplexers (infrared arrays). Practical FPA detector characterization is outlined. The nondestructive readout capability available in some CIDs and FPA devices is discussed as a means for signal-to-noise ratio improvement. Derivations of the equations are fully presented to unify understanding of this method by the spectroscopic community.

Truncation of the secondary concentrator (CPC) between maximum performances and economical requirements

NASA Astrophysics Data System (ADS)

Segal, A.; Epstein, M.

2009-08-01

A central solar plant, based on beam-down optics, is composed of a field of heliostats, a tower reflector and a ground receiver. The tower reflector is an optical system comprises of a quadric surface mirror (hyperboloid), where its upper focal point coincides with the aim point of a heliostat field and its lower focal point is located at a specified height, coinciding with the entrance plane of the ground receiver. The optics of a tower reflector requires the use of ground secondary concentrator, composed of a cluster of CPCs, because the quadric surface mirror always magnifies the sun image. There is an intrinsic correlation between the tower reflector position and its size on one hand, and the geometry, dimensions and reflective area of the secondary concentrator on the other hand; both are related to the heliostat field reflective area. Obviously, when one wishes to have a smaller tower reflector by placing it closer to the upper focal point, the image created at the lower focus will be larger, resulting in a larger secondary ground concentrator. The present work analyses the ways for a substantial decrease of the size of the ground concentrator cluster (and, implicit, the concentrators area) via truncation, without significant sacrifice of the performance, although some increase of the optical losses is inevitable. This offers a method for cost effective design of future central solar plants utilizing the beam down optics.

TRIGA: Telecommunications Protocol Processing Subsystem Using Reconfigurable Interoperable Gate Arrays

NASA Technical Reports Server (NTRS)

Pang, Jackson; Pingree, Paula J.; Torgerson, J. Leigh

2006-01-01

We present the Telecommunications protocol processing subsystem using Reconfigurable Interoperable Gate Arrays (TRIGA), a novel approach that unifies fault tolerance, error correction coding and interplanetary communication protocol off-loading to implement CCSDS File Delivery Protocol and Datalink layers. The new reconfigurable architecture offers more than one order of magnitude throughput increase while reducing footprint requirements in memory, command and data handling processor utilization, communication system interconnects and power consumption.

Thermodynamic Analysis of Beam down Solar Gas Turbine Power Plant equipped with Concentrating Receiver System

NASA Astrophysics Data System (ADS)

Azharuddin; Santarelli, Massimo

2016-09-01

Thermodynamic analysis of a closed cycle, solar powered Brayton gas turbine power plant with Concentrating Receiver system has been studied. A Brayton cycle is simpler than a Rankine cycle and has an advantage where the water is scarce. With the normal Brayton cycle a Concentrating Receiver System has been analysed which has a dependence on field density and optical system. This study presents a method of optimization of design parameter, such as the receiver working temperature and the heliostats density. This method aims at maximizing the overall efficiency of the three major subsystem that constitute the entire plant, namely, the heliostat field and the tower, the receiver and the power block. The results of the optimization process are shown and analysed.

Gaussian mixture models as flux prediction method for central receivers

NASA Astrophysics Data System (ADS)

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.

Solar augmentation for process heat with central receiver technology

NASA Astrophysics Data System (ADS)

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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 heliostatmore » 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.« less

NREL Researchers Test Solar Thermal Technology

Science.gov Websites

incorporates a number of design and manufacturing modifications that could make the heliostat less costly and make power tower systems cost competitive with conventional sources of electricity. Power towers, a

Self-pressurizing Stirling engine

DOEpatents

Bennett, Charles L.

2010-10-12

A solar thermal powered aircraft powered by heat energy from the sun. A heat engine, such as a Stirling engine, is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller. The heat engine has a thermal battery in thermal contact with it so that heat is supplied from the thermal battery. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

Solar thermal aircraft

DOEpatents

Bennett, Charles L.

2007-09-18

A solar thermal powered aircraft powered by heat energy from the sun. A heat engine, such as a Stirling engine, is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller. The heat engine has a thermal battery in thermal contact with it so that heat is supplied from the thermal battery. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

Method of forming structural heliostat

DOEpatents

Anderson, Alfred J.

1984-06-26

In forming a heliostat having a main support structure and pivoting and tilting motors and gears and a mirror module for reflecting solar energy onto a collector, the improvement characterized by a method of forming the mirror module in which the mirror is laid upon a solid rigid supporting bed in one or more sections, with or without focusing; a mirror backing sheet is applied by first applying respective thin layers of silicone grease and, thereafter, progressively rolling application to eliminate air bubbles; followed by affixing of a substrate assembly to the mirror backing sheet to form a mirror module that does not curve because of thermally induced stresses and differential thermal expansion or contraction effects. The silicone grease also serves to dampen fluttering of the mirror and protect the mirror backside against adverse effects of the weather. Also disclosed are specific details of preferred embodiments.

Solids-based concentrated solar power receiver

DOEpatents

None

2018-04-10

A concentrated solar power (CSP) system includes channels arranged to convey a flowing solids medium descending under gravity. The channels form a light-absorbing surface configured to absorb solar flux from a heliostat field. The channels may be independently supported, for example by suspension, and gaps between the channels are sized to accommodate thermal expansion. The light absorbing surface may be sloped so that the inside surfaces of the channels proximate to the light absorbing surface define downward-slanting channel floors, and the flowing solids medium flows along these floors. Baffles may be disposed inside the channels and oriented across the direction of descent of the flowing solids medium. The channels may include wedge-shaped walls forming the light-absorbing surface and defining multiple-reflection light paths for solar flux from the heliostat field incident on the light-absorbing surface.

TEM00 mode Nd:YAG solar laser by side-pumping a grooved rod

NASA Astrophysics Data System (ADS)

Vistas, Cláudia R.; Liang, Dawei; Almeida, Joana; Guillot, Emmanuel

2016-05-01

A simple TEM00 mode solar laser system with a grooved Nd:YAG rod pumped through a heliostat-parabolic mirror system is reported here. The radiation coupling capacity of a fused silica tube lens was combined with the multipass pumping ability of a 2 V-shaped cavity to provide efficient side-pumping along a 4.0 mm diameter grooved Nd:YAG single-crystal rod. TEM00 mode solar laser power of 3.4 W was measured by adopting an asymmetric large-mode laser resonant cavity. Record TEM00 mode solar laser collection efficiency of 3.4 W/m2and slope efficiency of 1.9% was achieved, which corresponds to 1.8 and 2.4 times more than the previous TEM00 mode Nd:YAG solar laser using the PROMES-CNRS heliostat-parabolic mirror system, respectively.

Evaluation of glare at the Ivanpah Solar Electric Generating System

DOE PAGES

Ho, C. K.; Sims, C. A.; Christian, J. M.

2015-06-05

The Ivanpah Solar Electric Generating System (ISEGS), located on I-15 about 40 miles (60 km) south of Las Vegas, NV, consists of three power towers 459 ft (140 m) tall and over 170,000 reflective heliostats with a rated capacity of 390 MW. In addition, reports of glare from the plant have been submitted by pilots and air traffic controllers and recorded by the Aviation Safety Reporting System and the California Energy Commission since 2013. Aerial and ground-based surveys of the glare were conducted in April, 2014, to identify the cause and to quantify the irradiance and potential ocular impacts ofmore » the glare. Results showed that the intense glare viewed from the airspace above ISEGS was caused by heliostats in standby mode that were aimed to the side of the receiver. Evaluation of the glare showed that the retinal irradiance and subtended source angle of the glare from the heliostats in standby were sufficient to cause significant ocular impact (potential for after-image) up to a distance of ~6 miles (10 km), but the values were below the threshold for permanent eye damage. Glare from the receivers had a low potential for after-image at all ground-based monitoring locations outside of the site boundaries. A Letter to Airmen has been issued by the Federal Aviation Administration to notify pilots of the potential glare hazards. Additional measures to mitigate the potential impacts of glare from ISGES are also presented and discussed.« less

A unified model for reverberation and submerged object scattering in a stratified ocean waveguide.

PubMed

Makris, N C; Ratilal, P

2001-03-01

A unified model for reverberation and submerged target scattering in a stratified medium is developed from wave theory. The advantage of the unified approach is that it enables quantitative predictions to be made of the target-echo-to-reverberation ratio in an ocean waveguide. Analytic expressions are derived for both deterministic and stochastic scattering from the seafloor and subseafloor. Asymptotic techniques are used to derive expressions for the scattering of broadband waveforms from distant objects or surfaces. Expressions are then obtained for the scattered field after beamforming with a horizontal line array. The model is applied to problems of active detection in shallow water. Sample calculations for narrow-band signals indicate that the detection of submerged target echoes above diffuse seafloor reverberation is highly dependent upon water column and sediment stratification as well as array aperture, source, receiver, and target locations, in addition to the scattering properties of the target and seafloor. The model is also applied to determine the conditions necessary for echo returns from discrete geomorphologic features of the seafloor and subseafloor to stand prominently above diffuse seafloor reverberation. This has great relevance to the geologic clutter problem encountered by active sonar systems operating in shallow water, as well as to the remote sensing of underwater geomorphology.

Predictive performance modeling framework for a novel enclosed particle receiver configuration and application for thermochemical energy storage

DOE PAGES

Martinek, Janna; Wendelin, Timothy; Ma, Zhiwen

2018-04-05

Concentrating solar power (CSP) plants can provide dispatchable power with a thermal energy storage capability for increased renewable-energy grid penetration. Particle-based CSP systems permit higher temperatures, and thus, potentially higher solar-to-electric efficiency than state-of-the-art molten-salt heat-transfer systems. This paper describes a detailed numerical analysis framework for estimating the performance of a novel, geometrically complex, enclosed particle receiver design. The receiver configuration uses arrays of small tubular absorbers to collect and subsequently transfer solar energy to a flowing particulate medium. The enclosed nature of the receiver design renders it amenable to either an inert heat-transfer medium, or a reactive heat-transfer medium that requires a controllable ambient environment. The numerical analysis framework described in this study is demonstrated for the case of thermal reduction of CaCr 0.1Mn 0.9O 3-more » $$\\delta$$ for thermochemical energy storage. The modeling strategy consists of Monte Carlo ray tracing for absorbed solar-energy distributions from a surround heliostat field, computational fluid dynamics modeling of small-scale local tubular arrays, surrogate response surfaces that approximately capture simulated tubular array performance, a quasi-two-dimensional reduced-order description of counter-flow reactive solids and purge gas, and a radiative exchange model applied to embedded-cavity structures at the size scale of the full receiver. In this work we apply the numerical analysis strategy to a single receiver configuration, but the framework can be generically applicable to alternative enclosed designs. In conclusion, we assess sensitivity of receiver performance to surface optical properties, heat-transfer coefficients, solids outlet temperature, and purge-gas feed rates, and discuss the significance of model assumptions and results for future receiver development.« less

Predictive performance modeling framework for a novel enclosed particle receiver configuration and application for thermochemical energy storage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martinek, Janna; Wendelin, Timothy; Ma, Zhiwen

Concentrating solar power (CSP) plants can provide dispatchable power with a thermal energy storage capability for increased renewable-energy grid penetration. Particle-based CSP systems permit higher temperatures, and thus, potentially higher solar-to-electric efficiency than state-of-the-art molten-salt heat-transfer systems. This paper describes a detailed numerical analysis framework for estimating the performance of a novel, geometrically complex, enclosed particle receiver design. The receiver configuration uses arrays of small tubular absorbers to collect and subsequently transfer solar energy to a flowing particulate medium. The enclosed nature of the receiver design renders it amenable to either an inert heat-transfer medium, or a reactive heat-transfer medium that requires a controllable ambient environment. The numerical analysis framework described in this study is demonstrated for the case of thermal reduction of CaCr 0.1Mn 0.9O 3-more » $$\\delta$$ for thermochemical energy storage. The modeling strategy consists of Monte Carlo ray tracing for absorbed solar-energy distributions from a surround heliostat field, computational fluid dynamics modeling of small-scale local tubular arrays, surrogate response surfaces that approximately capture simulated tubular array performance, a quasi-two-dimensional reduced-order description of counter-flow reactive solids and purge gas, and a radiative exchange model applied to embedded-cavity structures at the size scale of the full receiver. In this work we apply the numerical analysis strategy to a single receiver configuration, but the framework can be generically applicable to alternative enclosed designs. In conclusion, we assess sensitivity of receiver performance to surface optical properties, heat-transfer coefficients, solids outlet temperature, and purge-gas feed rates, and discuss the significance of model assumptions and results for future receiver development.« less

Tower-supported solar-energy collector

NASA Technical Reports Server (NTRS)

Selcuk, M. K.

1977-01-01

Multiple-collector tower system supports three receiver/concentrators that absorb solar energy reflected from surrounding field of heliostats. System overcomes disadvantages of tower-supported collectors. Booms can be lowered during heavy winds to protect arms and collectors.

Broken flow symmetry explains the dynamics of small particles in deterministic lateral displacement arrays.

PubMed

Kim, Sung-Cheol; Wunsch, Benjamin H; Hu, Huan; Smith, Joshua T; Austin, Robert H; Stolovitzky, Gustavo

2017-06-27

Deterministic lateral displacement (DLD) is a technique for size fractionation of particles in continuous flow that has shown great potential for biological applications. Several theoretical models have been proposed, but experimental evidence has demonstrated that a rich class of intermediate migration behavior exists, which is not predicted. We present a unified theoretical framework to infer the path of particles in the whole array on the basis of trajectories in a unit cell. This framework explains many of the unexpected particle trajectories reported and can be used to design arrays for even nanoscale particle fractionation. We performed experiments that verify these predictions and used our model to develop a condenser array that achieves full particle separation with a single fluidic input.

OLI Radiometric Calibration

NASA Technical Reports Server (NTRS)

Markham, Brian; Morfitt, Ron; Kvaran, Geir; Biggar, Stuart; Leisso, Nathan; Czapla-Myers, Jeff

2011-01-01

Goals: (1) Present an overview of the pre-launch radiance, reflectance & uniformity calibration of the Operational Land Imager (OLI) (1a) Transfer to orbit/heliostat (1b) Linearity (2) Discuss on-orbit plans for radiance, reflectance and uniformity calibration of the OLI

Themis - A solar power station

NASA Astrophysics Data System (ADS)

Hillairet, J.

The organization, goals, equipment, costs, and performance of the French Themis (Thermo-helio-electric-MW) project are outlined. The program was begun for both the domestic energy market and for export. The installation comprises a molten eutectic salt loop which receives heat from radiators situated in a central tower. The salt transfers the heat to water for steam generation of electricity. A storage tank holds enough molten salt to supply one day's reserve of power, 40 MWh. A field of heliostats directs the suns rays for an estimated 2400 hr/yr onto the central receiver aperture, while 11 additional parabolic concentrators provide sufficient heat to keep the salt reservoir at temperatures exceeding 200 C. In a test run of several months during the spring of 1982 the heliostats directed the sun's rays with an average efficiency of 75 percent, yielding 2.3 MW of power at a system efficiency of 20.5 percent in completely automatic operation.

Rankline-Brayton engine powered solar thermal aircraft

DOEpatents

Bennett, Charles L [Livermore, CA

2012-03-13

A solar thermal powered aircraft powered by heat energy from the sun. A Rankine-Brayton hybrid cycle heat engine is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller or other mechanism for enabling sustained free flight. The Rankine-Brayton engine has a thermal battery, preferably containing a lithium-hydride and lithium mixture, operably connected to it so that heat is supplied from the thermal battery to a working fluid. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

Rankine-Brayton engine powered solar thermal aircraft

DOEpatents

Bennett, Charles L [Livermore, CA

2009-12-29

A solar thermal powered aircraft powered by heat energy from the sun. A Rankine-Brayton hybrid cycle heat engine is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller or other mechanism for enabling sustained free flight. The Rankine-Brayton engine has a thermal battery, preferably containing a lithium-hydride and lithium mixture, operably connected to it so that heat is supplied from the thermal battery to a working fluid. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

An investigation into multi-dimensional prediction models to estimate the pose error of a quadcopter in a CSP plant setting

NASA Astrophysics Data System (ADS)

Lock, Jacobus C.; Smit, Willie J.; Treurnicht, Johann

2016-05-01

The Solar Thermal Energy Research Group (STERG) is investigating ways to make heliostats cheaper to reduce the total cost of a concentrating solar power (CSP) plant. One avenue of research is to use unmanned aerial vehicles (UAVs) to automate and assist with the heliostat calibration process. To do this, the pose estimation error of each UAV must be determined and integrated into a calibration procedure. A computer vision (CV) system is used to measure the pose of a quadcopter UAV. However, this CV system contains considerable measurement errors. Since this is a high-dimensional problem, a sophisticated prediction model must be used to estimate the measurement error of the CV system for any given pose measurement vector. This paper attempts to train and validate such a model with the aim of using it to determine the pose error of a quadcopter in a CSP plant setting.

Thermally stabilized heliostat

DOEpatents

Anderson, Alfred J.

1983-01-01

An improvement in a heliostat having a main support structure and pivoting and tilting motors and gears and a mirror module for reflecting solar energy onto a collector, the improvement being characterized by an internal support structure within each mirror module and front and back sheets attached to the internal support structure, the front and back sheets having the same coefficient of thermal expansion such that no curvature is induced by temperature change, and a layer of adhesive adhering the mirror to the front sheet. The adhesive is water repellent and has adequate set strength to support the mirror but has sufficient shear tolerance to permit the differential expansion of the mirror and the front sheet without inducing stresses or currature effect. The adhesive also serves to dampen fluttering of the mirror and to protect the mirror backside against the adverse effects of weather. Also disclosed are specific details of the preferred embodiment.

Backward-gazing method for measuring solar concentrators shape errors.

PubMed

Coquand, Mathieu; Henault, François; Caliot, Cyril

2017-03-01

This paper describes a backward-gazing method for measuring the optomechanical errors of solar concentrating surfaces. It makes use of four cameras placed near the solar receiver and simultaneously recording images of the sun reflected by the optical surfaces. Simple data processing then allows reconstructing the slope and shape errors of the surfaces. The originality of the method is enforced by the use of generalized quad-cell formulas and approximate mathematical relations between the slope errors of the mirrors and their reflected wavefront in the case of sun-tracking heliostats at high-incidence angles. Numerical simulations demonstrate that the measurement accuracy is compliant with standard requirements of solar concentrating optics in the presence of noise or calibration errors. The method is suited to fine characterization of the optical and mechanical errors of heliostats and their facets, or to provide better control for real-time sun tracking.

Tissue Damage, Temperature, and pH Induced by Different Electrode Arrays on Potato Pieces (Solanum tuberosum L.).

PubMed

González, Maraelys Morales; Aguilar, Claudia Hernández; Pacheco, Flavio Arturo Domínguez; Cabrales, Luis Enrique Bergues; Reyes, Juan Bory; Nava, Juan José Godina; Ambrosio, Paulo Eduardo; Domiguez, Dany Sanchez; Sierra González, Victoriano Gustavo; Pupo, Ana Elisa Bergues; Ciria, Héctor Manuel Camué; Alemán, Elizabeth Issac; García, Francisco Monier; Rivas, Clara Berenguer; Reina, Evelyn Chacón

2018-01-01

One of the most challenging problems of electrochemical therapy is the design and selection of suitable electrode array for cancer. The aim is to determine how two-dimensional spatial patterns of tissue damage, temperature, and pH induced in pieces of potato ( Solanum tuberosum L., var. Mondial) depend on electrode array with circular, elliptical, parabolic, and hyperbolic shape. The results show the similarity between the shapes of spatial patterns of tissue damage and electric field intensity, which, like temperature and pH take the same shape of electrode array. The adequate selection of suitable electrodes array requires an integrated analysis that involves, in a unified way, relevant information about the electrochemical process, which is essential to perform more efficiently way the therapeutic planning and the personalized therapy for patients with a cancerous tumor.

Remote monitoring of fish in small streams: A unified approach using PIT tags

USGS Publications Warehouse

Zydlewski, G.B.; Horton, G.; Dubreuil, T.; Letcher, B.; Casey, S.; Zydlewski, Joseph D.

2006-01-01

Accurate assessments of fish populations are often limited by re-observation or recapture events. Since the early 1990s, passive integrated transponders (PIT tags) have been used to understand the biology of many fish species. Until recently, PIT applications in small streams have been limited to physical recapture events. To maximize recapture probability, we constructed PIT antenna arrays in small streams to remotely detect individual fish. Experiences from two different laboratories (three case studies) allowed us to develop a unified approach to applying PIT technology for enhancing data assessments. Information on equipment, its installation, tag considerations, and array construction is provided. Theoretical and practical definitions are introduced to standardize metrics for assessing detection efficiency. We demonstrate how certain conditions (stream discharge, vibration, and ambient radio frequency noise) affect the detection efficiency and suggest that by monitoring these conditions, expectations of efficiency can be modified. We emphasize the importance of consistently estimating detection efficiency for fisheries applications.

Broken flow symmetry explains the dynamics of small particles in deterministic lateral displacement arrays

PubMed Central

Kim, Sung-Cheol; Wunsch, Benjamin H.; Hu, Huan; Smith, Joshua T.; Stolovitzky, Gustavo

2017-01-01

Deterministic lateral displacement (DLD) is a technique for size fractionation of particles in continuous flow that has shown great potential for biological applications. Several theoretical models have been proposed, but experimental evidence has demonstrated that a rich class of intermediate migration behavior exists, which is not predicted. We present a unified theoretical framework to infer the path of particles in the whole array on the basis of trajectories in a unit cell. This framework explains many of the unexpected particle trajectories reported and can be used to design arrays for even nanoscale particle fractionation. We performed experiments that verify these predictions and used our model to develop a condenser array that achieves full particle separation with a single fluidic input. PMID:28607075

Storage and computationally efficient permutations of factorized covariance and square-root information matrices

NASA Technical Reports Server (NTRS)

Muellerschoen, R. J.

1988-01-01

A unified method to permute vector-stored upper-triangular diagonal factorized covariance (UD) and vector stored upper-triangular square-root information filter (SRIF) arrays is presented. The method involves cyclical permutation of the rows and columns of the arrays and retriangularization with appropriate square-root-free fast Givens rotations or elementary slow Givens reflections. A minimal amount of computation is performed and only one scratch vector of size N is required, where N is the column dimension of the arrays. To make the method efficient for large SRIF arrays on a virtual memory machine, three additional scratch vectors each of size N are used to avoid expensive paging faults. The method discussed is compared with the methods and routines of Bierman's Estimation Subroutine Library (ESL).

Cleaner for Solar-Collector Covers

NASA Technical Reports Server (NTRS)

Frickland, P. O.; Cleland, E. L.

1983-01-01

Simple self-contained cleaning system proposed for solar collectors or solar-collector protective domes. Perforated transparent plastic cap attached to top of protective dome in heliostat solar-energy collection system distributes cleaning fluid over surface of dome without blocking significant fraction of solar radiation.

Tissue Damage, Temperature, and pH Induced by Different Electrode Arrays on Potato Pieces (Solanum tuberosum L.)

PubMed Central

González, Maraelys Morales; Aguilar, Claudia Hernández; Pacheco, Flavio Arturo Domínguez; Cabrales, Luis Enrique Bergues; Reyes, Juan Bory; Nava, Juan José Godina; Ambrosio, Paulo Eduardo; Domiguez, Dany Sanchez; Sierra González, Victoriano Gustavo; Pupo, Ana Elisa Bergues; Ciria, Héctor Manuel Camué; Alemán, Elizabeth Issac; García, Francisco Monier; Rivas, Clara Berenguer; Reina, Evelyn Chacón

2018-01-01

One of the most challenging problems of electrochemical therapy is the design and selection of suitable electrode array for cancer. The aim is to determine how two-dimensional spatial patterns of tissue damage, temperature, and pH induced in pieces of potato (Solanum tuberosum L., var. Mondial) depend on electrode array with circular, elliptical, parabolic, and hyperbolic shape. The results show the similarity between the shapes of spatial patterns of tissue damage and electric field intensity, which, like temperature and pH take the same shape of electrode array. The adequate selection of suitable electrodes array requires an integrated analysis that involves, in a unified way, relevant information about the electrochemical process, which is essential to perform more efficiently way the therapeutic planning and the personalized therapy for patients with a cancerous tumor. PMID:29725584

A cost-effective methodology for the design of massively-parallel VLSI functional units

NASA Technical Reports Server (NTRS)

Venkateswaran, N.; Sriram, G.; Desouza, J.

1993-01-01

In this paper we propose a generalized methodology for the design of cost-effective massively-parallel VLSI Functional Units. This methodology is based on a technique of generating and reducing a massive bit-array on the mask-programmable PAcube VLSI array. This methodology unifies (maintains identical data flow and control) the execution of complex arithmetic functions on PAcube arrays. It is highly regular, expandable and uniform with respect to problem-size and wordlength, thereby reducing the communication complexity. The memory-functional unit interface is regular and expandable. Using this technique functional units of dedicated processors can be mask-programmed on the naked PAcube arrays, reducing the turn-around time. The production cost of such dedicated processors can be drastically reduced since the naked PAcube arrays can be mass-produced. Analysis of the the performance of functional units designed by our method yields promising results.

A Unified Taxonomic Approach to the Laboratory Assessment of Visionic Devices

DTIC Science & Technology

2006-09-01

the ratification stage with member nations. Marasco and Task 4 presented a large array of tests applicable to image intensification-based visionic...aircraft.” In print. 4. Marasco , P. L., and Task, H. L. 1999. “Optical characterization of wide field-of-view night vision devices,” in

Exploring the Validity of a Unified Learning Program for Remedial and Handicapped Students.

ERIC Educational Resources Information Center

Jenkins, Joseph R.; And Others

The instructional and political validity of current educational policy regarding categorical programs for low-achieving elementary school students are examined. The categorical organization of services for these students, characterized by a vast array of eligibility requirements, rules and regulations, and accounting systems, has resulted in a…

Performance Analysis of a NASA Integrated Network Array

NASA Technical Reports Server (NTRS)

Nessel, James A.

2012-01-01

The Space Communications and Navigation (SCaN) Program is planning to integrate its individual networks into a unified network which will function as a single entity to provide services to user missions. This integrated network architecture is expected to provide SCaN customers with the capabilities to seamlessly use any of the available SCaN assets to support their missions to efficiently meet the collective needs of Agency missions. One potential optimal application of these assets, based on this envisioned architecture, is that of arraying across existing networks to significantly enhance data rates and/or link availabilities. As such, this document provides an analysis of the transmit and receive performance of a proposed SCaN inter-network antenna array. From the study, it is determined that a fully integrated internetwork array does not provide any significant advantage over an intra-network array, one in which the assets of an individual network are arrayed for enhanced performance. Therefore, it is the recommendation of this study that NASA proceed with an arraying concept, with a fundamental focus on a network-centric arraying.

Investigation of the growth of directionally solidified eutectics with potential as electron emitters

NASA Technical Reports Server (NTRS)

Chapman, A. T.; Cochran, J. K.

1976-01-01

The construction of a solar furnace was completed and it was tested after a preliminary alignment of the heliostat mirrors. After final alignment, the solar furnace is used for directional solidification experiments designed to simulate space conditions.

Weather Driven Renewable Energy Analysis, Modeling New Technologies

NASA Astrophysics Data System (ADS)

Paine, J.; Clack, C.; Picciano, P.; Terry, L.

2015-12-01

Carbon emission reduction is essential to hampering anthropogenic climate change. While there are several methods to broach carbon reductions, the National Energy with Weather System (NEWS) model focuses on limiting electrical generation emissions by way of a national high-voltage direct-current transmission that takes advantage of the strengths of different regions in terms of variable sources of energy. Specifically, we focus upon modeling concentrating solar power (CSP) as another source to contribute to the electric grid. Power tower solar fields are optimized taking into account high spatial and temporal resolution, 13km and hourly, numerical weather prediction model data gathered by NOAA from the years of 2006-2008. Importantly, the optimization of these CSP power plants takes into consideration factors that decrease the optical efficiency of the heliostats reflecting solar irradiance. For example, cosine efficiency, atmospheric attenuation, and shadowing are shown here; however, it should be noted that they are not the only limiting factors. While solar photovoltaic plants can be combined for similar efficiency to the power tower and currently at a lower cost, they do not have a cost-effective capability to provide electricity when there are interruptions in solar irradiance. Power towers rely on a heat transfer fluid, which can be used for thermal storage changing the cost efficiency of this energy source. Thermal storage increases the electric stability that many other renewable energy sources lack, and thus, the ability to choose between direct electric conversion and thermal storage is discussed. The figure shown is a test model of a CSP plant made up of heliostats. The colors show the optical efficiency of each heliostat at a single time of the day.

First Results & Future Prospects for 30 GeV Gamma Rays from CELESTE

NASA Astrophysics Data System (ADS)

de Naurois, Mathieu

The CELESTE solar farm gamma-ray telescope detected the Crab Nebula at 80 GeV ( Hz) using 18 heliostats in 1998. In March 1999, observations began with a setup extended to 40 heliostats, and with upgraded electronics. Technical delays and bad weather only permitted a very small data set for the Crab nebula. hours of data were taken simultaneously with the CAT imaging telescope showing evidence for a gamma signal. In this talk the analysis method of these data is described. CELESTE has passed major milestones and the groundwork is laid for the blazar and pulsar studies presented elsewhere in this conference (OG 2.1.20, OG 2.2.31). DEDICATION : CELESTE is the brainchild of Eric Pare, who died at the age of 39 in an automobile accident, two weeks after finding our first gamma ray signal. Eric also played a major role in the conception and design of CAT. We dedicate this work to his memory.

Toward large-scale solar energy systems with peak concentrations of 20,000 suns

NASA Astrophysics Data System (ADS)

Kribus, Abraham

1997-10-01

The heliostat field plays a crucial role in defining the achievable limits for central receiver system efficiency and cost. Increasing system efficiency, thus reducing the reflective area and system cost, can be achieved by increasing the concentration and the receiver temperature. The concentration achievable in central receiver plants, however, is constrained by current heliostat technology and design practices. The factors affecting field performance are surface and tracking errors, astigmatism, shadowing, blocking and dilution. These are geometric factors that can be systematically treated and reduced. We present improvements in collection optics and technology that may boost concentration (up to 20,000 peak), achievable temperature (2,000 K), and efficiency in solar central receiver plants. The increased performance may significantly reduce the cost of solar energy in existing applications, and enable solar access to new ultra-high-temperature applications, such as: future gas turbines approaching 60% combined cycle efficiency; high-temperature thermo-chemical processes; and gas-dynamic processes.

High contrast observations of bright stars with a starshade

NASA Astrophysics Data System (ADS)

Harness, Anthony; Cash, Webster; Warwick, Steve

2017-11-01

Starshades are a leading technology to enable the direct detection and spectroscopic characterization of Earth-like exoplanets. In an effort to advance starshade technology through system level demonstrations, the McMath-Pierce Solar Telescope was adapted to enable the suppression of astronomical sources with a starshade. The long baselines achievable with the heliostat provide measurements of starshade performance at a flight-like Fresnel number and resolution, aspects critical to the validation of optical models. The heliostat has provided the opportunity to perform the first astronomical observations with a starshade and has made science accessible in a unique parameter space, high contrast at moderate inner working angles. On-sky images are valuable for developing the experience and tools needed to extract science results from future starshade observations. We report on high contrast observations of nearby stars provided by a starshade. We achieve 5.6 × 10- 7 contrast at 30 arcseconds inner working angle on the star Vega and provide new photometric constraints on background stars near Vega.

Efficiency improvement of a concentrated solar receiver for water heating system using porous medium

NASA Astrophysics Data System (ADS)

Prasartkaew, Boonrit

2018-01-01

This experimental study aims at investigating on the performance of a high temperature solar water heating system. To approach the high temperature, a porous-medium concentrated solar collector equipped with a focused solar heliostat were proposed. The proposed system comprised of two parts: a 0.7x0.7-m2 porous medium receiver, was installed on a 3-m tower, and a focused multi-flat-mirror solar heliostat with 25-m2 aperture area. The porous medium used in this study was the metal swarf or metal waste from lathing process. To know how the system efficiency could be improved by using such porous medium, the proposed system with- and without-porous medium were tested and the comparative study was performed. The experimental results show that, using porous medium for enhancing the heat transfer mechanism, the system thermal efficiency was increased about 25%. It can be concluded that the efficiency of the proposed system can be substantially improved by using the porous medium.

NREL Researchers Test Solar Thermal Technology

Science.gov Websites

and manufacturing modifications that could lead to significant cost reductions. The major modifications include a larger reflective area (170 square meters) and a low-cost mirror facet design in which this program. SAIC's low cost stretched-membrane heliostat represents a significant advancement in

Solar central receiver hybrid power system, phase 1. Volume 3: Appendices

NASA Astrophysics Data System (ADS)

1979-09-01

Parametric salt piping data, sample heat exchanger calculations, and salt/materials compatibility evaluations are presented. Data lists that include the heliostat field coordinates, the STEAEC program input data, the hybrid receiver design drawings and models, and the piping stress analysis are also presented.

Thermodynamic and design considerations of organic Rankine cycles in combined application with a solar thermal gas turbine

NASA Astrophysics Data System (ADS)

Braun, R.; Kusterer, K.; Sugimoto, T.; Tanimura, K.; Bohn, D.

2013-12-01

Concentrated Solar Power (CSP) technologies are considered to provide a significant contribution for the electric power production in the future. Different kinds of technologies are presently in operation or under development, e.g. parabolic troughs, central receivers, solar dish systems and Fresnel reflectors. This paper takes the focus on central receiver technologies, where the solar radiation is concentrated by a field of heliostats in a receiver on the top of a tall tower. To get this CSP technology ready for the future, the system costs have to reduce significantly. The main cost driver in such kind of CSP technologies are the huge amount of heliostats. To reduce the amount of heliostats, and so the investment costs, the efficiency of the energy conversion cycle becomes an important issue. An increase in the cycle efficiency results in a decrease of the solar heliostat field and thus, in a significant cost reduction. The paper presents the results of a thermodynamic model of an Organic Rankine Cycle (ORC) for combined cycle application together with a solar thermal gas turbine. The gas turbine cycle is modeled with an additional intercooler and recuperator and is based on a typical industrial gas turbine in the 2 MW class. The gas turbine has a two stage radial compressor and a three stage axial turbine. The compressed air is preheated within a solar receiver to 950°C before entering the combustor. A hybrid operation of the gas turbine is considered. In order to achieve a further increase of the overall efficiency, the combined operation of the gas turbine and an Organic Rankine Cycle is considered. Therefore an ORC has been set up, which is thermally connected to the gas turbine cycle at two positions. The ORC can be coupled to the solar-thermal gas turbine cycle at the intercooler and after the recuperator. Thus, waste heat from different cycle positions can be transferred to the ORC for additional production of electricity. Within this investigation different working fluids and ORC conditions have been analyzed in order to evaluate the best configuration. The investigations have been performed by application of improved thermodynamic and process analysis tools, which consider the real gas behavior of the analyzed fluids. The results show that by combined operation of the solar thermal gas turbine and the ORC, the combined cycle efficiency is approximately 4%-points higher than in the solar-thermal gas turbine cycle.

Polar exponential sensor arrays unify iconic and Hough space representation

NASA Technical Reports Server (NTRS)

Weiman, Carl F. R.

1990-01-01

The log-polar coordinate system, inherent in both polar exponential sensor arrays and log-polar remapped video imagery, is identical to the coordinate system of its corresponding Hough transform parameter space. The resulting unification of iconic and Hough domains simplifies computation for line recognition and eliminates the slope quantization problems inherent in the classical Cartesian Hough transform. The geometric organization of the algorithm is more amenable to massively parallel architectures than that of the Cartesian version. The neural architecture of the human visual cortex meets the geometric requirements to execute 'in-place' log-Hough algorithms of the kind described here.

A class of least-squares filtering and identification algorithms with systolic array architectures

NASA Technical Reports Server (NTRS)

Kalson, Seth Z.; Yao, Kung

1991-01-01

A unified approach is presented for deriving a large class of new and previously known time- and order-recursive least-squares algorithms with systolic array architectures, suitable for high-throughput-rate and VLSI implementations of space-time filtering and system identification problems. The geometrical derivation given is unique in that no assumption is made concerning the rank of the sample data correlation matrix. This method utilizes and extends the concept of oblique projections, as used previously in the derivations of the least-squares lattice algorithms. Exponentially weighted least-squares criteria are considered for both sliding and growing memory.

Brevard Community Colege: Instructional Innovation for the Space Age

ERIC Educational Resources Information Center

King, Maxwell; Breuder, Robert L.

1977-01-01

A description of the Astronaut Memorial Hall and Planetarium at Brevard Community College. Its space museum contains space hardware from Mercury, Gemini, Apollo. A teaching observatory includes radio-telescope laboratory, 40 seat classroom, heliostat room. The planetarium features a computerized starfield projector, wrap-around dome, and ramped…

Unified Access Architecture for Large-Scale Scientific Datasets

NASA Astrophysics Data System (ADS)

Karna, Risav

2014-05-01

Data-intensive sciences have to deploy diverse large scale database technologies for data analytics as scientists have now been dealing with much larger volume than ever before. While array databases have bridged many gaps between the needs of data-intensive research fields and DBMS technologies (Zhang 2011), invocation of other big data tools accompanying these databases is still manual and separate the database management's interface. We identify this as an architectural challenge that will increasingly complicate the user's work flow owing to the growing number of useful but isolated and niche database tools. Such use of data analysis tools in effect leaves the burden on the user's end to synchronize the results from other data manipulation analysis tools with the database management system. To this end, we propose a unified access interface for using big data tools within large scale scientific array database using the database queries themselves to embed foreign routines belonging to the big data tools. Such an invocation of foreign data manipulation routines inside a query into a database can be made possible through a user-defined function (UDF). UDFs that allow such levels of freedom as to call modules from another language and interface back and forth between the query body and the side-loaded functions would be needed for this purpose. For the purpose of this research we attempt coupling of four widely used tools Hadoop (hadoop1), Matlab (matlab1), R (r1) and ScaLAPACK (scalapack1) with UDF feature of rasdaman (Baumann 98), an array-based data manager, for investigating this concept. The native array data model used by an array-based data manager provides compact data storage and high performance operations on ordered data such as spatial data, temporal data, and matrix-based data for linear algebra operations (scidbusr1). Performances issues arising due to coupling of tools with different paradigms, niche functionalities, separate processes and output data formats have been anticipated and considered during the design of the unified architecture. The research focuses on the feasibility of the designed coupling mechanism and the evaluation of the efficiency and benefits of our proposed unified access architecture. Zhang 2011: Zhang, Ying and Kersten, Martin and Ivanova, Milena and Nes, Niels, SciQL: Bridging the Gap Between Science and Relational DBMS, Proceedings of the 15th Symposium on International Database Engineering Applications, 2011. Baumann 98: Baumann, P., Dehmel, A., Furtado, P., Ritsch, R., Widmann, N., "The Multidimensional Database System RasDaMan", SIGMOD 1998, Proceedings ACM SIGMOD International Conference on Management of Data, June 2-4, 1998, Seattle, Washington, 1998. hadoop1: hadoop.apache.org, "Hadoop", http://hadoop.apache.org/, [Online; accessed 12-Jan-2014]. scalapack1: netlib.org/scalapack, "ScaLAPACK", http://www.netlib.org/scalapack,[Online; accessed 12-Jan-2014]. r1: r-project.org, "R", http://www.r-project.org/,[Online; accessed 12-Jan-2014]. matlab1: mathworks.com, "Matlab Documentation", http://www.mathworks.de/de/help/matlab/,[Online; accessed 12-Jan-2014]. scidbusr1: scidb.org, "SciDB User's Guide", http://scidb.org/HTMLmanual/13.6/scidb_ug,[Online; accessed 01-Dec-2013].

A user's manual for DELSOL3: A computer code for calculating the optical performance and optimal system design for solar thermal central receiver plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kistler, B.L.

DELSOL3 is a revised and updated version of the DELSOL2 computer program (SAND81-8237) for calculating collector field performance and layout and optimal system design for solar thermal central receiver plants. The code consists of a detailed model of the optical performance, a simpler model of the non-optical performance, an algorithm for field layout, and a searching algorithm to find the best system design based on energy cost. The latter two features are coupled to a cost model of central receiver components and an economic model for calculating energy costs. The code can handle flat, focused and/or canted heliostats, and externalmore » cylindrical, multi-aperture cavity, and flat plate receivers. The program optimizes the tower height, receiver size, field layout, heliostat spacings, and tower position at user specified power levels subject to flux limits on the receiver and land constraints for field layout. DELSOL3 maintains the advantages of speed and accuracy which are characteristics of DELSOL2.« less

Conceptual Design of a 100 MWe Modular Molten Salt Power Tower Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

James E. Pacheco; Carter Moursund, Dale Rogers, David Wasyluk

2011-09-20

A conceptual design of a 100 MWe modular molten salt solar power tower plant has been developed which can provide capacity factors in the range of 35 to 75%. Compared to single tower plants, the modular design provides a higher degree of flexibility in achieving the desired customer's capacity factor and is obtained simply by adjusting the number of standard modules. Each module consists of a standard size heliostat field and receiver system, hence reengineering and associated unacceptable performance uncertainties due to scaling are eliminated. The modular approach with multiple towers also improves plant availability. Heliostat field components, receivers andmore » towers are shop assembled allowing for high quality and minimal field assembly. A centralized thermal-storage system stores hot salt from the receivers, allowing nearly continuous power production, independent of solar energy collection, and improved parity with the grid. A molten salt steam generator converts the stored thermal energy into steam, which powers a steam turbine generator to produce electricity. This paper describes the conceptual design of the plant, the advantages of modularity, expected performance, pathways to cost reductions, and environmental impact.« less

Method of and apparatus for collecting solar radiation utilizing variable curvature cylindrical reflectors

DOEpatents

Treytl, William J.; Slemmons, Arthur J.; Andeen, Gerry B.

1979-01-01

A heliostat apparatus includes a frame which is rotatable about an axis which is parallel to the aperture plane of an elongate receiver. A plurality of flat flexible mirror elements are mounted to the frame between several parallel, uniformly spaced resilient beams which are pivotally connected at their ends to the frame. Channels are mounted to the sides of the beams for supporting the edges of the mirror elements. Each of the beams has a longitudinally varying configuration designed to bow into predetermined, generally circular curvatures of varying radii when the center of the beam is deflected relative to the pivotally connected ends of the beams. All of the parallel resilient beams are simultaneously deflected by a cam shaft assembly extending through openings in the centers of the beams, whereby the mirror elements together form an upwardly concave, cylindrical reflecting surface. The heliostat is rotated about its axis to track the apparent diurnal movement of the sun, while the reflecting surface is substantially simultaneously bowed into a cylindrical trough having a radius adapted to focus incident light at the plane of the receiver aperture.

Simulation and experimental research of 1MWe solar tower power plant in China

NASA Astrophysics Data System (ADS)

Yu, Qiang; Wang, Zhifeng; Xu, Ershu

2016-05-01

The establishment of a reliable simulation system for a solar tower power plant can greatly increase the economic and safety performance of the whole system. In this paper, a dynamic model of the 1MWe Solar Tower Power Plant at Badaling in Beijing is developed based on the "STAR-90" simulation platform, including the heliostat field, the central receiver system (water/steam), etc. The dynamic behavior of the global CSP plant can be simulated. In order to verify the validity of simulation system, a complete experimental process was synchronously simulated by repeating the same operating steps based on the simulation platform, including the locations and number of heliostats, the mass flow of the feed water, etc. According to the simulation and experimental results, some important parameters are taken out to make a deep comparison. The results show that there is good alignment between the simulations and the experimental results and that the error range can be acceptable considering the error of the models. In the end, a comprehensive and deep analysis on the error source is carried out according to the comparative results.

Symbioses: a key driver of insect physiological processes, ecological interactions, evolutionary diversification, and impacts on humans

Treesearch

K.D. Klepzig; A.S. Adams; J. Handelsman; K.F. Raffa

2009-01-01

Symbiosis is receiving increased attention among all aspects of biology because of the unifying themes it helps construct across ecological,evolutionary, developmental, semiochemical, and pest management theory. Insects show a vast array of symbiotic relationships with a wide diversity of microorganisms. These relationships may confer a variety of benefits to the host...

Symbioses: A key driver of insect physiological processes, ecological interactions, evolutionary diversification, and impacts on humans

Treesearch

Kier Klepzig; A.S. Adams; J Handelsman; K.F. Raffa

2009-01-01

Symbiosis is receiving increased attention among all aspects of biology because of the unifying themes it helps construct across ecological, evolutionary, developmental, semiochemical, and pest management theory. Insects show a vast array of symbiotic relationships with a wide diversity of microorganisms. These relationships may confer a variety of benefits to the host...

Achieving control and interoperability through unified model-based systems and software engineering

NASA Technical Reports Server (NTRS)

Rasmussen, Robert; Ingham, Michel; Dvorak, Daniel

2005-01-01

Control and interoperation of complex systems is one of the most difficult challenges facing NASA's Exploration Systems Mission Directorate. An integrated but diverse array of vehicles, habitats, and supporting facilities, evolving over the long course of the enterprise, must perform ever more complex tasks while moving steadily away from the sphere of ground support and intervention.

Real-time radar signal processing using GPGPU (general-purpose graphic processing unit)

NASA Astrophysics Data System (ADS)

Kong, Fanxing; Zhang, Yan Rockee; Cai, Jingxiao; Palmer, Robert D.

2016-05-01

This study introduces a practical approach to develop real-time signal processing chain for general phased array radar on NVIDIA GPUs(Graphical Processing Units) using CUDA (Compute Unified Device Architecture) libraries such as cuBlas and cuFFT, which are adopted from open source libraries and optimized for the NVIDIA GPUs. The processed results are rigorously verified against those from the CPUs. Performance benchmarked in computation time with various input data cube sizes are compared across GPUs and CPUs. Through the analysis, it will be demonstrated that GPGPUs (General Purpose GPU) real-time processing of the array radar data is possible with relatively low-cost commercial GPUs.

Towards a flexible array control and operation framework for CTA

NASA Astrophysics Data System (ADS)

Birsin, E.; Colomé, J.; Hoffmann, D.; Koeppel, H.; Lamanna, G.; Le Flour, T.; Lopatin, A.; Lyard, E.; Melkumyan, D.; Oya, I.; Panazol, J.-L.; Schlenstedt, S.; Schmidt, T.; Schwanke, U.; Stegmann, C.; Walter, R.; Wegner, P.; CTA Consortium

2012-12-01

The Cherenkov Telescope Array (CTA) [1] will be the successor to current Imaging Atmospheric Cherenkov Telescopes (IACT) like H.E.S.S., MAGIC and VERITAS. CTA will improve in sensitivity by about an order of magnitude compared to the current generation of IACTs. The energy range will extend from well below 100 GeV to above 100 TeV. To accomplish these goals, CTA will consist of two arrays, one in each hemisphere, consisting of 50-80 telescopes and composed of three different telescope types with different mirror sizes. It will be the first open observatory for very high energy γ-ray astronomy. The Array Control working group of CTA is currently evaluating existing technologies which are best suited for a project like CTA. The considered solutions comprise the ALMA Common Software (ACS), the OPC Unified Architecture (OPC UA) and the Data Distribution Service (DDS) for bulk data transfer. The first applications, like an automatic observation scheduler and the control software for some prototype instrumentation have been developed.

ERDA's central receiver solar thermal power system studies

NASA Technical Reports Server (NTRS)

Lippy, L. J.; Heaton, T. R.

1977-01-01

The utilization of solar energy for electrical power production was studied. Efforts underway on the central receiver solar thermal power system are presented. Preliminary designs are included of pilot plant utilizing large numbers of heliostats in a collector field. Safety hazards are also discussed, as well as the most beneficial location of such a plant within the United States.

76 FR 70125 - Notice of Availability of the Draft Environmental Impact Statement for the Proposed Solar Reserve...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-10

... central receiver or tower, a solar field consisting of mirrors or heliostats to reflect the sun's energy... Environmental Impact Statement for the Proposed Solar Reserve LLC Quartzsite Solar Energy Project, La Paz County... (DEIS) for the proposed Quartzsite Solar Energy Project (Project), in La Paz County, Arizona, and the...

A Unified Approach to Passive and Active Ocean Acoustic Waveguide Remote Sensing

DTIC Science & Technology

2012-09-30

acoustic sensing reveals humpback whale behavior synchronous with herring spawning processes and sonar had no effect on humpback song ,” submitted to...source and receiver arrays to enable instantaneous continental-shelf scale imaging and continuous monitoring of fish and whale populations. Acoustic...Preliminary analysis shows that humpback whale behavior is synchronous with peak annual Atlantic herring spawning processes in the Gulf of

Analytical and numerical solutions of the potential and electric field generated by different electrode arrays in a tumor tissue under electrotherapy.

PubMed

Bergues Pupo, Ana E; Reyes, Juan Bory; Bergues Cabrales, Luis E; Bergues Cabrales, Jesús M

2011-09-24

Electrotherapy is a relatively well established and efficient method of tumor treatment. In this paper we focus on analytical and numerical calculations of the potential and electric field distributions inside a tumor tissue in a two-dimensional model (2D-model) generated by means of electrode arrays with shapes of different conic sections (ellipse, parabola and hyperbola). Analytical calculations of the potential and electric field distributions based on 2D-models for different electrode arrays are performed by solving the Laplace equation, meanwhile the numerical solution is solved by means of finite element method in two dimensions. Both analytical and numerical solutions reveal significant differences between the electric field distributions generated by electrode arrays with shapes of circle and different conic sections (elliptic, parabolic and hyperbolic). Electrode arrays with circular, elliptical and hyperbolic shapes have the advantage of concentrating the electric field lines in the tumor. The mathematical approach presented in this study provides a useful tool for the design of electrode arrays with different shapes of conic sections by means of the use of the unifying principle. At the same time, we verify the good correspondence between the analytical and numerical solutions for the potential and electric field distributions generated by the electrode array with different conic sections.

Microscopy of biological sample through advanced diffractive optics from visible to X-ray wavelength regime.

PubMed

Di Fabrizio, Enzo; Cojoc, Dan; Emiliani, Valentina; Cabrini, Stefano; Coppey-Moisan, Maite; Ferrari, Enrico; Garbin, Valeria; Altissimo, Matteo

2004-11-01

The aim of this report is to demonstrate a unified version of microscopy through the use of advanced diffractive optics. The unified scheme derives from the technical possibility of realizing front wave engineering in a wide range of electromagnetic spectrum. The unified treatment is realized through the design and nanofabrication of phase diffractive elements (PDE) through which wave front beam shaping is obtained. In particular, we will show applications, by using biological samples, ranging from micromanipulation using optical tweezers to X-ray differential interference contrast (DIC) microscopy combined with X-ray fluorescence. We report some details on the design and physical implementation of diffractive elements that besides focusing also perform other optical functions: beam splitting, beam intensity, and phase redistribution or mode conversion. Laser beam splitting is used for multiple trapping and independent manipulation of micro-beads surrounding a cell as an array of tweezers and for arraying and sorting microscopic size biological samples. Another application is the Gauss to Laguerre-Gauss mode conversion, which allows for trapping and transfering orbital angular momentum of light to micro-particles immersed in a fluid. These experiments are performed in an inverted optical microscope coupled with an infrared laser beam and a spatial light modulator for diffractive optics implementation. High-resolution optics, fabricated by means of e-beam lithography, are demonstrated to control the intensity and the phase of the sheared beams in x-ray DIC microscopy. DIC experiments with phase objects reveal a dramatic increase in image contrast compared to bright-field x-ray microscopy. Besides the topographic information, fluorescence allows detection of certain chemical elements (Cl, P, Sc, K) in the same setup, by changing the photon energy of the x-ray beam. (c) 2005 Wiley-Liss, Inc.

Blazar Astronomy above 50 GeV

NASA Astrophysics Data System (ADS)

Smith, D. A.

This contribution is dedicated to the memory of Chaman L. Bhat, an atmospheric Cherenkov pioneer and a leader of the Indian gamma-ray community, who died in a road accident on Mt. Abu on December 17, just after the workshop. While few blazars have been detected beyond EGRET energies, these extreme cases may be the ones that 'make or break' some models describing blazars in particular, and therefore AGNs in general. This paper first reviews the status of the various atmospheric Cherenkov gamma-ray telescopes. We then describe the most recent results from these instruments, paying particular attention to the recent detection of 1ES 1426+428 by the Whipple, CAT, and HEGRA imagers. We illustrate the dilemma of target selection using the example of W Com. We then discuss the consequences of the first measurements of Mrk 421 below 100 GeV by the solar heliostat arrays CELESTE and STACEE. This first foray into the energy range linking EGRET with the current imagers requires us to start using functional forms for the spectral energy distributions that are more physical than the simple power laws (or parabolas) used up to now to describe the imager or satellite results. We can hope that HESS, followed by MAGIC and VERITAS, as well as CELESTE and STACEE, will make this a recurring problem in 2002 and 2003.

Colorimetric Sensor Arrays for the Detection and Identification of Chemical Weapons and Explosives

PubMed Central

Kangas, Michael J.; Burks, Raychelle M.; Atwater, Jordyn; Lukowicz, Rachel M.; Williams, Pat; Holmes, Andrea E.

2017-01-01

ABSTRACT There is a significant demand for devices that can rapidly detect chemical–biological–explosive (CBE) threats on-site and allow for immediate responders to mitigate spread, risk, and loss. The key to an effective reconnaissance mission is a unified detection technology that analyzes potential threats in real time. In addition to reviewing the current state of the art in the field, this review illustrates the practicality of colorimetric arrays composed of sensors that change colors in the presence of analytes. This review also describes an outlook toward future technologies, and describes how they could possibly be used in areas such as war zones to detect and identify hazardous substances. PMID:27636675

Colorimetric Sensor Arrays for the Detection and Identification of Chemical Weapons and Explosives.

PubMed

Kangas, Michael J; Burks, Raychelle M; Atwater, Jordyn; Lukowicz, Rachel M; Williams, Pat; Holmes, Andrea E

2017-03-04

There is a significant demand for devices that can rapidly detect chemical-biological-explosive (CBE) threats on-site and allow for immediate responders to mitigate spread, risk, and loss. The key to an effective reconnaissance mission is a unified detection technology that analyzes potential threats in real time. In addition to reviewing the current state of the art in the field, this review illustrates the practicality of colorimetric arrays composed of sensors that change colors in the presence of analytes. This review also describes an outlook toward future technologies, and describes how they could possibly be used in areas such as war zones to detect and identify hazardous substances.

Cutting the Stovepipes: An Improved Staff Model for the Modern Unified Commander

DTIC Science & Technology

2001-04-01

quick to point out, their profit was the result of creating an environment that liberated people’s creativity , nurtured their commitment, and inspired...production networks, and telecommuting .”23 These businesses operate in an electronic world (vice physical) and are facilitated by an array of information...achieve the efficiencies and creativity businesses have gained in the virtual and reengineered environments, while at the same time retaining the

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jonathan Helmus, Scott Collis

The Python-ARM Radar Toolkit (Py-ART) is a collection of radar quality control and retrieval codes which all work on two unifying Python objects: the PyRadar and PyGrid objects. By building ingests to several popular radar formats and then abstracting the interface Py-ART greatly simplifies data processing over several other available utilities. In addition Py-ART makes use of Numpy arrays as its primary storage mechanism enabling use of existing and extensive community software tools.

Final Test and Evaluation Results from the Solar Two Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

BRADSHAW, ROBERT W.; DAWSON, DANIEL B.; DE LA ROSA, WILFREDO

Solar Two was a collaborative, cost-shared project between 11 U. S. industry and utility partners and the U. S. Department of Energy to validate molten-salt power tower technology. The Solar Two plant, located east of Barstow, CA, comprised 1926 heliostats, a receiver, a thermal storage system, a steam generation system, and steam-turbine power block. Molten nitrate salt was used as the heat transfer fluid and storage media. The steam generator powered a 10-MWe (megawatt electric), conventional Rankine cycle turbine. Solar Two operated from June 1996 to April 1999. The major objective of the test and evaluation phase of the projectmore » was to validate the technical characteristics of a molten salt power tower. This report describes the significant results from the test and evaluation activities, the operating experience of each major system, and overall plant performance. Tests were conducted to measure the power output (MW) of the each major system, the efficiencies of the heliostat, receiver, thermal storage, and electric power generation systems and the daily energy collected, daily thermal-to-electric conversion, and daily parasitic energy consumption. Also included are detailed test and evaluation reports.« less

Analytical and numerical solutions of the potential and electric field generated by different electrode arrays in a tumor tissue under electrotherapy

PubMed Central

2011-01-01

Background Electrotherapy is a relatively well established and efficient method of tumor treatment. In this paper we focus on analytical and numerical calculations of the potential and electric field distributions inside a tumor tissue in a two-dimensional model (2D-model) generated by means of electrode arrays with shapes of different conic sections (ellipse, parabola and hyperbola). Methods Analytical calculations of the potential and electric field distributions based on 2D-models for different electrode arrays are performed by solving the Laplace equation, meanwhile the numerical solution is solved by means of finite element method in two dimensions. Results Both analytical and numerical solutions reveal significant differences between the electric field distributions generated by electrode arrays with shapes of circle and different conic sections (elliptic, parabolic and hyperbolic). Electrode arrays with circular, elliptical and hyperbolic shapes have the advantage of concentrating the electric field lines in the tumor. Conclusion The mathematical approach presented in this study provides a useful tool for the design of electrode arrays with different shapes of conic sections by means of the use of the unifying principle. At the same time, we verify the good correspondence between the analytical and numerical solutions for the potential and electric field distributions generated by the electrode array with different conic sections. PMID:21943385

Retooling Institutional Support Infrastructure for Clinical Research

PubMed Central

Snyder, Denise C.; Brouwer, Rebecca N.; Ennis, Cory L.; Spangler, Lindsey L.; Ainsworth, Terry L.; Budinger, Susan; Mullen, Catherine; Hawley, Jeffrey; Uhlenbrauck, Gina; Stacy, Mark

2016-01-01

Clinical research activities at academic medical centers are challenging to oversee. Without effective research administration, a continually evolving set of regulatory and institutional requirements can detract investigator and study team attention away from a focus on scientific gain, study conduct, and patient safety. However, even when the need for research administration is recognized, there can be struggles over what form it should take. Central research administration may be viewed negatively, with individual groups preferring to maintain autonomy over processes. Conversely, a proliferation of individualized approaches across an institution can create inefficiencies or invite risk. This article describes experiences establishing a unified research support office at the Duke University School of Medicine based on a framework of customer support. The Duke Office of Clinical Research was formed in 2012 with a vision that research administration at academic medical centers should help clinical investigators navigate the complex research environment and operationalize research ideas. The office provides an array of services that have received high satisfaction ratings. The authors describe the ongoing culture change necessary for success of the unified research support office. Lessons learned from implementation of the Duke Office of Clinical Research may serve as a model for other institutions undergoing a transition to unified research support. PMID:27125563

Unified viscoelasticity: Applying discrete element models to soft tissues with two characteristic times.

PubMed

Anssari-Benam, Afshin; Bucchi, Andrea; Bader, Dan L

2015-09-18

Discrete element models have often been the primary tool in investigating and characterising the viscoelastic behaviour of soft tissues. However, studies have employed varied configurations of these models, based on the choice of the number of elements and the utilised formation, for different subject tissues. This approach has yielded a diverse array of viscoelastic models in the literature, each seemingly resulting in different descriptions of viscoelastic constitutive behaviour and/or stress-relaxation and creep functions. Moreover, most studies do not apply a single discrete element model to characterise both stress-relaxation and creep behaviours of tissues. The underlying assumption for this disparity is the implicit perception that the viscoelasticity of soft tissues cannot be described by a universal behaviour or law, resulting in the lack of a unified approach in the literature based on discrete element representations. This paper derives the constitutive equation for different viscoelastic models applicable to soft tissues with two characteristic times. It demonstrates that all possible configurations exhibit a unified and universal behaviour, captured by a single constitutive relationship between stress, strain and time as: σ+Aσ̇+Bσ¨=Pε̇+Qε¨. The ensuing stress-relaxation G(t) and creep J(t) functions are also unified and universal, derived as [Formula: see text] and J(t)=c2+(ε0-c2)e(-PQt)+σ0Pt, respectively. Application of these relationships to experimental data is illustrated for various tissues including the aortic valve, ligament and cerebral artery. The unified model presented in this paper may be applied to all tissues with two characteristic times, obviating the need for employing varied configurations of discrete element models in preliminary investigation of the viscoelastic behaviour of soft tissues. Copyright © 2015 Elsevier Ltd. All rights reserved.

A unifying framework for systems modeling, control systems design, and system operation

NASA Technical Reports Server (NTRS)

Dvorak, Daniel L.; Indictor, Mark B.; Ingham, Michel D.; Rasmussen, Robert D.; Stringfellow, Margaret V.

2005-01-01

Current engineering practice in the analysis and design of large-scale multi-disciplinary control systems is typified by some form of decomposition- whether functional or physical or discipline-based-that enables multiple teams to work in parallel and in relative isolation. Too often, the resulting system after integration is an awkward marriage of different control and data mechanisms with poor end-to-end accountability. System of systems engineering, which faces this problem on a large scale, cries out for a unifying framework to guide analysis, design, and operation. This paper describes such a framework based on a state-, model-, and goal-based architecture for semi-autonomous control systems that guides analysis and modeling, shapes control system software design, and directly specifies operational intent. This paper illustrates the key concepts in the context of a large-scale, concurrent, globally distributed system of systems: NASA's proposed Array-based Deep Space Network.

Solar central receiver heliostat reflector assembly

DOEpatents

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.

Adaptive Residual Interpolation for Color and Multispectral Image Demosaicking †

PubMed Central

Kiku, Daisuke; Okutomi, Masatoshi

2017-01-01

Color image demosaicking for the Bayer color filter array is an essential image processing operation for acquiring high-quality color images. Recently, residual interpolation (RI)-based algorithms have demonstrated superior demosaicking performance over conventional color difference interpolation-based algorithms. In this paper, we propose adaptive residual interpolation (ARI) that improves existing RI-based algorithms by adaptively combining two RI-based algorithms and selecting a suitable iteration number at each pixel. These are performed based on a unified criterion that evaluates the validity of an RI-based algorithm. Experimental comparisons using standard color image datasets demonstrate that ARI can improve existing RI-based algorithms by more than 0.6 dB in the color peak signal-to-noise ratio and can outperform state-of-the-art algorithms based on training images. We further extend ARI for a multispectral filter array, in which more than three spectral bands are arrayed, and demonstrate that ARI can achieve state-of-the-art performance also for the task of multispectral image demosaicking. PMID:29194407

Adaptive Residual Interpolation for Color and Multispectral Image Demosaicking.

PubMed

Monno, Yusuke; Kiku, Daisuke; Tanaka, Masayuki; Okutomi, Masatoshi

2017-12-01

Color image demosaicking for the Bayer color filter array is an essential image processing operation for acquiring high-quality color images. Recently, residual interpolation (RI)-based algorithms have demonstrated superior demosaicking performance over conventional color difference interpolation-based algorithms. In this paper, we propose adaptive residual interpolation (ARI) that improves existing RI-based algorithms by adaptively combining two RI-based algorithms and selecting a suitable iteration number at each pixel. These are performed based on a unified criterion that evaluates the validity of an RI-based algorithm. Experimental comparisons using standard color image datasets demonstrate that ARI can improve existing RI-based algorithms by more than 0.6 dB in the color peak signal-to-noise ratio and can outperform state-of-the-art algorithms based on training images. We further extend ARI for a multispectral filter array, in which more than three spectral bands are arrayed, and demonstrate that ARI can achieve state-of-the-art performance also for the task of multispectral image demosaicking.

Stokes parameters of phase-locked partially coherent flat-topped array laser beams propagating through turbulent atmosphere

NASA Astrophysics Data System (ADS)

Golmohammady, Sh; Ghafary, B.

2016-06-01

In this study, generalized Stokes parameters of a phase-locked partially coherent flat-topped array beam based on the extended Huygens-Fresnel principle and the unified theory of coherence and polarization have been reported. Analytical formulas for 2  ×  2 cross-spectral density matrix elements, and consequently Stokes parameters of a phase-locked partially coherent flat-topped array beam propagating through the turbulent atmosphere have been formulated. Effects of many physical attributes such as wavelength, turbulence strength, flatness order and other source parameters on the Stokes parameters, and therefore spectral degree of polarization upon propagation have been studied thoroughly. The behaviour of the spectral degree of coherence of a delineated beam for different source conditions has been investigated. It can be shown that four generalized Stokes parameters increase by raising the flatness order at the same propagation distance. Increasing the number of beams leads to a decrease in the Stokes parameters to zero slowly. The results are of utmost importance for optical communications.

Integrated parallel reception, excitation, and shimming (iPRES).

PubMed

Han, Hui; Song, Allen W; Truong, Trong-Kha

2013-07-01

To develop a new concept for a hardware platform that enables integrated parallel reception, excitation, and shimming. This concept uses a single coil array rather than separate arrays for parallel excitation/reception and B0 shimming. It relies on a novel design that allows a radiofrequency current (for excitation/reception) and a direct current (for B0 shimming) to coexist independently in the same coil. Proof-of-concept B0 shimming experiments were performed with a two-coil array in a phantom, whereas B0 shimming simulations were performed with a 48-coil array in the human brain. Our experiments show that individually optimized direct currents applied in each coil can reduce the B0 root-mean-square error by 62-81% and minimize distortions in echo-planar images. The simulations show that dynamic shimming with the 48-coil integrated parallel reception, excitation, and shimming array can reduce the B0 root-mean-square error in the prefrontal and temporal regions by 66-79% as compared with static second-order spherical harmonic shimming and by 12-23% as compared with dynamic shimming with a 48-coil conventional shim array. Our results demonstrate the feasibility of the integrated parallel reception, excitation, and shimming concept to perform parallel excitation/reception and B0 shimming with a unified coil system as well as its promise for in vivo applications. Copyright © 2013 Wiley Periodicals, Inc.

Integrated Parallel Reception, Excitation, and Shimming (iPRES)

PubMed Central

Han, Hui; Song, Allen W.; Truong, Trong-Kha

2013-01-01

Purpose To develop a new concept for a hardware platform that enables integrated parallel reception, excitation, and shimming (iPRES). Theory This concept uses a single coil array rather than separate arrays for parallel excitation/reception and B0 shimming. It relies on a novel design that allows a radiofrequency current (for excitation/reception) and a direct current (for B0 shimming) to coexist independently in the same coil. Methods Proof-of-concept B0 shimming experiments were performed with a two-coil array in a phantom, whereas B0 shimming simulations were performed with a 48-coil array in the human brain. Results Our experiments show that individually optimized direct currents applied in each coil can reduce the B0 root-mean-square error by 62–81% and minimize distortions in echo-planar images. The simulations show that dynamic shimming with the 48-coil iPRES array can reduce the B0 root-mean-square error in the prefrontal and temporal regions by 66–79% as compared to static 2nd-order spherical harmonic shimming and by 12–23% as compared to dynamic shimming with a 48-coil conventional shim array. Conclusion Our results demonstrate the feasibility of the iPRES concept to perform parallel excitation/reception and B0 shimming with a unified coil system as well as its promise for in vivo applications. PMID:23629974

The standardized EEG electrode array of the IFCN.

PubMed

Seeck, Margitta; Koessler, Laurent; Bast, Thomas; Leijten, Frans; Michel, Christoph; Baumgartner, Christoph; He, Bin; Beniczky, Sándor

2017-10-01

Standardized EEG electrode positions are essential for both clinical applications and research. The aim of this guideline is to update and expand the unifying nomenclature and standardized positioning for EEG scalp electrodes. Electrode positions were based on 20% and 10% of standardized measurements from anatomical landmarks on the skull. However, standard recordings do not cover the anterior and basal temporal lobes, which is the most frequent source of epileptogenic activity. Here, we propose a basic array of 25 electrodes including the inferior temporal chain, which should be used for all standard clinical recordings. The nomenclature in the basic array is consistent with the 10-10-system. High-density scalp EEG arrays (64-256 electrodes) allow source imaging with even sub-lobar precision. This supplementary exam should be requested whenever necessary, e.g. search for epileptogenic activity in negative standard EEG or for presurgical evaluation. In the near future, nomenclature for high density electrodes arrays beyond the 10-10 system needs to be defined, to allow comparison and standardized recordings across centers. Contrary to the established belief that smaller heads needs less electrodes, in young children at least as many electrodes as in adults should be applied due to smaller skull thickness and the risk of spatial aliasing. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Combine Flash-Based FPGA TID and Long-Term Retention Reliabilities Through VT Shift

NASA Astrophysics Data System (ADS)

Wang, Jih-Jong; Rezzak, Nadia; Dsilva, Durwyn; Xue, Fengliang; Samiee, Salim; Singaraju, Pavan; Jia, James; Nguyen, Victor; Hawley, Frank; Hamdy, Esmat

2016-08-01

Reliability test results of data retention and total ionizing dose (TID) in 65 nm Flash-based field programmable gate array (FPGA) are presented. Long-chain inverter design is recommended for reliability evaluation because it is the worst case design for both effects. Based on preliminary test data, both issues are unified and modeled by one natural decay equation. The relative contributions of TID induced threshold-voltage shift and retention mechanisms are evaluated by analyzing test data.

Solar energy collection system

NASA Technical Reports Server (NTRS)

Selcuk, M. K. (Inventor)

1977-01-01

An improved solar energy collection system, having enhanced energy collection and conversion capabilities, is delineated. The system is characterized by a plurality of receivers suspended above a heliostat field comprising a multiplicity of reflector surfaces, each being adapted to direct a concentrated beam of solar energy to illuminate a target surface for a given receiver. A magnitude of efficiency, suitable for effectively competing with systems employed in collecting and converting energy extracted from fossil fuels, is indicated.

Coupled optical and thermal detailed simulations for the accurate evaluation and performance improvement of molten salts solar towers

NASA Astrophysics Data System (ADS)

García-Barberena, Javier; Mutuberria, Amaia; Palacin, Luis G.; Sanz, Javier L.; Pereira, Daniel; Bernardos, Ana; Sanchez, Marcelino; Rocha, Alberto R.

2017-06-01

The National Renewable Energy Centre of Spain, CENER, and the Technology & Innovation area of ACS Cobra, as a result of their long term expertise in the CSP field, have developed a high-quality and high level of detail optical and thermal simulation software for the accurate evaluation of Molten Salts Solar Towers. The main purpose of this software is to make a step forward in the state-of-the-art of the Solar Towers simulation programs. Generally, these programs deal with the most critical systems of such plants, i.e. the solar field and the receiver, on an independent basis. Therefore, these programs typically neglect relevant aspects in the operation of the plant as heliostat aiming strategies, solar flux shapes onto the receiver, material physical and operational limitations, transient processes as preheating and secure cloud passing operating modes, and more. The modelling approach implemented in the developed program consists on effectively coupling detailed optical simulations of the heliostat field with also detailed and full-transient thermal simulations of the molten salts tube-based external receiver. The optical model is based on an accurate Monte Carlo ray-tracing method which solves the complete solar field by simulating each of the heliostats at once according to their specific layout in the field. In the thermal side, the tube-based cylindrical external receiver of a Molten Salts Solar Tower is modelled assuming one representative tube per panel, and implementing the specific connection layout of the panels as well as the internal receiver pipes. Each tube is longitudinally discretized and the transient energy and mass balances in the temperature dependent molten salts and steel tube models are solved. For this, a one dimensional radial heat transfer model based is used. The thermal model is completed with a detailed control and operation strategy module, able to represent the appropriate operation of the plant. An integration framework has been developed, helping ACS Cobra to adequately handle the optical and thermal coupled simulations. According to current results it can be concluded that the developed model has resulted in a powerful tool to improve the design and operation of future ACS Cobra's Molten Salts Solar Towers, since historical data based on its projects have been used for validation of the final tool.

Measurement of external forces and torques on a large pointing system

NASA Technical Reports Server (NTRS)

Morenus, R. C.

1980-01-01

Methods of measuring external forces and torques are discussed, in general and as applied to the Large Pointing System wind tunnel tests. The LPS tests were in two phases. The first test was a preliminary test of three models representing coelostat, heliostat, and on-gimbal telescope configurations. The second test explored the coelostat configuration in more detail. The second test used a different setup for measuring external loads. Some results are given from both tests.

Review of avian mortality studies at concentrating solar power plants

NASA Astrophysics Data System (ADS)

Ho, Clifford K.

2016-05-01

This paper reviews past and current avian mortality studies at concentrating solar power (CSP) plants and facilities including Solar One in California, the Solar Energy Development Center in Israel, Ivanpah Solar Electric Generating System in California, Crescent Dunes in Nevada, and Gemasolar in Spain. Findings indicate that the leading causes of bird deaths at CSP plants are from collisions (primarily with reflective surfaces; i.e., heliostats) and singeing caused by concentrated solar flux. Safe irradiance levels for birds have been reported to range between 4 and 50 kW/m2. Above these levels, singeing and irreversible damage to the feathers can occur. Despite observations of large numbers of "streamers" in concentrated flux regions and reports that suggest these streamers indicate complete vaporization of birds, analyses in this paper show that complete vaporization of birds is highly improbable, and the observed streamers are likely due to insects flying into the concentrated flux. The levelized avian mortality rate during the first year of operation at Ivanpah was estimated to be 0.7 - 3.5 fatalities per GWh, which is less than the levelized avian mortality reported for fossil fuel plants but greater than that for nuclear and wind power plants. Mitigation measures include acoustic, visual, tactile, and chemosensory deterrents to keep birds away from the plant, and heliostat aiming strategies that reduce the solar flux during standby.

Techno-economic optimization of a scaled-up solar concentrator combined with CSPonD thermal energy storage

NASA Astrophysics Data System (ADS)

Musi, Richard; Grange, Benjamin; Diago, Miguel; Topel, Monika; Armstrong, Peter; Slocum, Alexander; Calvet, Nicolas

2017-06-01

A molten salt direct absorption receiver, CSPonD, used to simultaneously collect and store thermal energy is being tested by Masdar Institute and MIT in Abu Dhabi, UAE. Whilst a research-scale prototype has been combined with a beam-down tower in Abu Dhabi, the original design coupled the receiver with a hillside heliostat field. With respect to a conventional power-tower setup, a hillside solar field presents the advantages of eliminating tower costs, heat tracing equipment, and high-pressure pumps. This analysis considers the industrial viability of the CSPonD concept by modeling a 10 MWe up-scaled version of a molten salt direct absorption receiver combined with a hillside heliostat field. Five different slope angles are initially simulated to determine the optimum choice using a combination of lowest LCOE and highest IRR, and sensitivity analyses are carried out based on thermal energy storage duration, power output, and feed-in tariff price. Finally, multi-objective optimization is undertaken to determine a Pareto front representing optimum cases. The study indicates that a 40° slope and a combination of 14 h thermal energy storage with a 40-50 MWe power output provide the best techno-economic results. By selecting one simulated result and using a feed-in tariff of 0.25 /kWh, a competitive IRR of 15.01 % can be achieved.

ASTRID© - Advanced Solar Tubular ReceIver Design: A powerful tool for receiver design and optimization

NASA Astrophysics Data System (ADS)

Frantz, Cathy; Fritsch, Andreas; Uhlig, Ralf

2017-06-01

In solar tower power plants the receiver is one of the critical components. It converts the solar radiation into heat and must withstand high heat flux densities and high daily or even hourly gradients (due to passage of clouds). For this reason, the challenge during receiver design is to find a reasonable compromise between receiver efficiency, reliability, lifetime and cost. There is a strong interaction between the heliostat field, the receiver and the heat transfer fluid. Therefore, a proper receiver design needs to consider these components within the receiver optimization. There are several design and optimization tools for receivers, but most of them focus only on the receiver, ignoring the heliostat field and other parts of the plant. During the last years DLR developed the ASTRIDcode for tubular receiver concept simulation. The code comprises both a high and a low-detail model. The low-detail model utilizes a number of simplifications which allow the user to screen a high number of receiver concepts for optimization purposes. The high-detail model uses a FE model and is able to compute local absorber and salt temperatures with high accuracy. One key strength of the ASTRIDcode is its interface to a ray tracing software which simulates a realistic heat flux distributions on the receiver surface. The results generated by the ASTRIDcode have been validated by CFD simulations and measurement data.

Optical losses of solar mirrors due to atmospheric contamination at Liberal, Kansas and Oologah, Oklahoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dake, L.S.; Lind, M.A.

An assessment is presented of the effect of outdoor exposure on mirrors located at two sites selected for potential solar cogeneration/repowering facilities: Liberal, Kansas and Oologah, Oklahoma. Mirror coupons were placed on tracking heliostat simulators located in the proposed heliostat fields and were removed periodically. The spectral hemispherical and diffuse reflectances of these coupons were measured. Representative samples were analyzed for the chemical composition of the dust particulates using SEM/EDX. Other samples were washed with a high pressure spray and recharacterized to determine the effects of the residual dust. Average specular reflectance losses over the entire test period (up tomore » 504 days) were 6 to 12%, with a range of 1 to 30%. Specular reflectance losses varied widely from day to day depending on local weather conditions. The losses due to scattering were 2 to 5 times greater than the losses due to absorptance. The average degradation rate over the first thirty days was an order of magnitude larger than the average degradation rate over the entire sampling period. Specular reflectance loss rates averaged 0.5% per day and greater between periods of natural cleaning. The chemical composition of the dust on the mirrors was characteristic of the indigenous soil, with some samples also showing the presence of sulfur and chlorine, possibly from cooling tower drift.« less

Experimenting with concentrated sunlight using the DLR solar furnace

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neumann, A.; Groer, U.

1996-10-01

The high flux solar furnace that is operated by the Deutsche Forschungsanstalt fuer Luft- und Raumfahrt (DLR) at Cologne was inaugurated in June 1994 and we are now able to look back onto one year of successful operation. The solar furnace project was founded by the government of the State Northrhine Westfalia within the Study Group AG Solar. The optical design is a two-stage off-axis configuration which uses a flat 52 m{sup 2} heliostat and a concentrator composed of 147 spherical mirror facets. The heliostat redirects the solar light onto the concentrator which focuses the beam out of the opticalmore » axis of the system into the laboratory building. At high insolation levels (>800W/m{sup 2}) it is possible to collect a total power of 20 kW with peak flux densities of 4 MW/m{sup 2}. Sixteen different experiment campaigns were carried out during this first year of operation. The main research fields for these experiments were material science, component development and solar chemistry. The furnace also has its own research program leading to develop sophisticated measurement techniques like remote infrared temperature sensing and flux mapping. Another future goal to be realized within the next five years is the improvement of the performance of the furnace itself. 6 refs., 9 figs., 1 tab.« less

Detection methods for stochastic gravitational-wave backgrounds: a unified treatment

NASA Astrophysics Data System (ADS)

Romano, Joseph D.; Cornish, Neil. J.

2017-04-01

We review detection methods that are currently in use or have been proposed to search for a stochastic background of gravitational radiation. We consider both Bayesian and frequentist searches using ground-based and space-based laser interferometers, spacecraft Doppler tracking, and pulsar timing arrays; and we allow for anisotropy, non-Gaussianity, and non-standard polarization states. Our focus is on relevant data analysis issues, and not on the particular astrophysical or early Universe sources that might give rise to such backgrounds. We provide a unified treatment of these searches at the level of detector response functions, detection sensitivity curves, and, more generally, at the level of the likelihood function, since the choice of signal and noise models and prior probability distributions are actually what define the search. Pedagogical examples are given whenever possible to compare and contrast different approaches. We have tried to make the article as self-contained and comprehensive as possible, targeting graduate students and new researchers looking to enter this field.

Fabrication and Testing of a Modular Micro-Pocket Fission Detector Instrumentation System for Test Nuclear Reactors

NASA Astrophysics Data System (ADS)

Reichenberger, Michael A.; Nichols, Daniel M.; Stevenson, Sarah R.; Swope, Tanner M.; Hilger, Caden W.; Roberts, Jeremy A.; Unruh, Troy C.; McGregor, Douglas S.

2018-01-01

Advancements in nuclear reactor core modeling and computational capability have encouraged further development of in-core neutron sensors. Measurement of the neutron-flux distribution within the reactor core provides a more complete understanding of the operating conditions in the reactor than typical ex-core sensors. Micro-Pocket Fission Detectors have been developed and tested previously but have been limited to single-node operation and have utilized highly specialized designs. The development of a widely deployable, multi-node Micro-Pocket Fission Detector assembly will enhance nuclear research capabilities. A modular, four-node Micro-Pocket Fission Detector array was designed, fabricated, and tested at Kansas State University. The array was constructed from materials that do not significantly perturb the neutron flux in the reactor core. All four sensor nodes were equally spaced axially in the array to span the fuel-region of the reactor core. The array was filled with neon gas, serving as an ionization medium in the small cavities of the Micro-Pocket Fission Detectors. The modular design of the instrument facilitates the testing and deployment of numerous sensor arrays. The unified design drastically improved device ruggedness and simplified construction from previous designs. Five 8-mm penetrations in the upper grid plate of the Kansas State University TRIGA Mk. II research nuclear reactor were utilized to deploy the array between fuel elements in the core. The Micro-Pocket Fission Detector array was coupled to an electronic support system which has been specially developed to support pulse-mode operation. The Micro-Pocket Fission Detector array composed of four sensors was used to monitor local neutron flux at a constant reactor power of 100 kWth at different axial locations simultaneously. The array was positioned at five different radial locations within the core to emulate the deployment of multiple arrays and develop a 2-dimensional measurement of neutron flux in the reactor core.

Solar central electric power generation - A baseline design

NASA Technical Reports Server (NTRS)

Powell, J. C.

1976-01-01

The paper presents the conceptual technical baseline design of a solar electric power plant using the central receiver concept, and derives credible cost estimates from the baseline design. The major components of the plant - heliostats, tower, receiver, tower piping, and thermal storage - are discussed in terms of technical and cost information. The assumed peak plant output is 215 MW(e), over 4000 daylight hours. The contribution of total capital investment to energy cost is estimated to be about 55 mills per kwh in mid-1974 dollars.

[Occupational hygiene at solar-energy electric power plants].

PubMed

Lipkina, L I; Kolesnikova, A V; Tsirkova, N L

1991-01-01

The labour conditions of the personnel engaged in servicing an experimental solar electric power station in warm seasons of the year were characterized by the unfavourable environmental factors peculiar of working out-doors (heliostat sites) and in the station's shops (solar radiation, heating microclimate, noise). Combinations and activity of those factors were professionally determined. Established was the role of the labour conditions and respective occupational peculiarities in the individual response formation to work overload. A set of health-related preventive measures was also proposed.

Heterogeneous Structure and Seismicity beneath the Tokyo Metropolitan Area

NASA Astrophysics Data System (ADS)

Nakagawa, S.; Kato, A.; Sakai, S.; Nanjo, K.; Panayotopoulos, Y.; Kurashimo, E.; Obara, K.; Kasahara, K.; Aketagawa, T.; Kimura, H.; Hirata, N.

2010-12-01

Beneath the Tokyo metropolitan area, the Philippine Sea Plate (PSP) subducts and causes damaged mega-thrust earthquakes. Sato et al. (2005) revealed the geometry of upper surface of PSP, and Hagiwara et al. (2006) estimated the velocity structure beneath Boso peninsula. However, these results are not sufficient for the assessment of the entire picture of the seismic hazards beneath the Tokyo metropolitan area including those due to an intra-slab M7+ earthquake. So, we launched the Special Project for Earthquake Disaster Mitigation in the Tokyo Metropolitan area (Hirata et al., 2009). Proving the more detailed geometry and physical properties (e.g. velocities, densities, attenuation) and stress field within PSP is very important to attain this issue. The core item of this project is a dense seismic array called Metropolitan Seismic Observation network (MeSO-net) for making observations in the metropolitan area (Sakai and Hirata, 2009; Kasahara et al., 2009). We deployed the 249 seismic stations with a spacing of 5 km. Some parts of stations construct 5 linear arrays at interval of 2 km such as Tsukuba-Fujisawa (TF) array, etc. The TF array runs from northeast to southwest through the center of Tokyo. In this study, we applied the tomography method to image the heterogeneous structure under the Tokyo metropolitan area. We selected events from the Japan Meteorological Agency (JMA) unified earthquake list. All data of MeSO-net were edited into event data by the selected JMA unified earthquake list. We picked the P and S wave arrival times. The total number of stations and events are 421 and 1,256, respectively. Then, we applied the double-difference tomography method (Zhang and Thurber, 2003) to this dataset and estimated the fine-scale velocity structure. The grid nodes locate 10 km interval in parallel with the array, 20 km interval in perpendicular to the array; and on depth direction, 5 km interval to a depth of less than 50 km and 10 km interval at a depth of more. We used 158,930 (P wave) and 149,308 (S wave) absolute arrival times, and 374,072 (P wave) and 354,912 (S wave) differential travel times. The initial velocity structure is the JMA2001 (Ueno et al., 2001), and the Vp/Vs ratio is set to 1.73 for all grid nodes. We imaged the subducting PSP and Pacific Plate clearly. The depth section of P-wave velocity structure along the TF array clearly shows that thin low-velocity layer which overlies high-velocity layer subducts towards northeast. This low-velocity layer corresponds to the oceanic crust of the subducting PSP. The obtained tomograms combined with seismicity and focal mechanisms indicate that the interior of the subducting PSP is characterized by heterogeneous structures, which could exert a profound influence on the genesis of intra-slab earthquakes. Acknowledgement: This study was supported by the Earthquake Research Institute cooperative research program.

Deferred slanted-edge analysis: a unified approach to spatial frequency response measurement on distorted images and color filter array subsets.

PubMed

van den Bergh, F

2018-03-01

The slanted-edge method of spatial frequency response (SFR) measurement is usually applied to grayscale images under the assumption that any distortion of the expected straight edge is negligible. By decoupling the edge orientation and position estimation step from the edge spread function construction step, it is shown in this paper that the slanted-edge method can be extended to allow it to be applied to images suffering from significant geometric distortion, such as produced by equiangular fisheye lenses. This same decoupling also allows the slanted-edge method to be applied directly to Bayer-mosaicked images so that the SFR of the color filter array subsets can be measured directly without the unwanted influence of demosaicking artifacts. Numerical simulation results are presented to demonstrate the efficacy of the proposed deferred slanted-edge method in relation to existing methods.

Fabrication and testing of a 4-node micro-pocket fission detector array for the Kansas State University TRIGA Mk. II research nuclear reactor

NASA Astrophysics Data System (ADS)

Reichenberger, Michael A.; Nichols, Daniel M.; Stevenson, Sarah R.; Swope, Tanner M.; Hilger, Caden W.; Unruh, Troy C.; McGregor, Douglas S.; Roberts, Jeremy A.

2017-08-01

Advancements in nuclear reactor core modeling and computational capability have encouraged further development of in-core neutron sensors. Micro-Pocket Fission Detectors (MPFDs) have been fabricated and tested previously, but successful testing of these prior detectors was limited to single-node operation with specialized designs. Described in this work is a modular, four-node MPFD array fabricated and tested at Kansas State University (KSU). The four sensor nodes were equally spaced to span the length of the fuel-region of the KSU TRIGA Mk. II research nuclear reactor core. The encapsulated array was filled with argon gas, serving as an ionization medium in the small cavities of the MPFDs. The unified design improved device ruggedness and simplified construction over previous designs. A 0.315-in. (8-mm) penetration in the upper grid plate of the KSU TRIGA Mk. II research nuclear reactor was used to deploy the array between fuel elements in the core. The MPFD array was coupled to an electronic support system which has been developed to support pulse-mode operation. Neutron-induced pulses were observed on all four sensor channels. Stable device operation was confirmed by testing under steady-state reactor conditions. Each of the four sensors in the array responded to changes in reactor power between 10 kWth and full power (750 kWth). Reactor power transients were observed in real-time including positive transients with periods of 5, 15, and 30 s. Finally, manual reactor power oscillations were observed in real-time.

Simultaneous operation and control of about 100 telescopes for the Cherenkov Telescope Array

NASA Astrophysics Data System (ADS)

Wegner, P.; Colomé, J.; Hoffmann, D.; Houles, J.; Köppel, H.; Lamanna, G.; Le Flour, T.; Lopatin, A.; Lyard, E.; Melkumyan, D.; Oya, I.; Panazol, L.-I.; Punch, M.; Schlenstedt, S.; Schmidt, T.; Stegmann, C.; Schwanke, U.; Walter, R.; Consortium, CTA

2012-12-01

The Cherenkov Telescope Array (CTA) project is an initiative to build the next generation ground-based very high energy (VHE) gamma-ray instrument. Compared to current imaging atmospheric Cherenkov telescope experiments CTA will extend the energy range and improve the angular resolution while increasing the sensitivity up to a factor of 10. With about 100 separate telescopes it will be operated as an observatory open to a wide astrophysics and particle physics community, providing a deep insight into the non-thermal high-energy universe. The CTA Array Control system (ACTL) is responsible for several essential control tasks supporting the evaluation and selection of proposals, as well as the preparation, scheduling, and finally the execution of observations with the array. A possible basic distributed software framework for ACTL being considered is the ALMA Common Software (ACS). The ACS framework follows a container component model and contains a high level abstraction layer to integrate different types of device. To achieve a low-level consolidation of connecting control hardware, OPC UA (OPen Connectivity-Unified Architecture) client functionality is integrated directly into ACS, thus allowing interaction with other OPC UA capable hardware. The CTA Data Acquisition System comprises the data readout of all cameras and the transfer of the data to a camera server farm, thereby using standard hardware and software technologies. CTA array control is also covering conceptions for a possible array trigger system and the corresponding clock distribution. The design of the CTA observations scheduler is introducing new algorithmic technologies to achieve the required flexibility.

Solar energy incident at the receiver of a solar tower plant, derived from remote sensing: Computation of both DNI and slant path transmittance

NASA Astrophysics Data System (ADS)

Elias, Thierry; Ramon, Didier; Garnero, Marie-Agnès; Dubus, Laurent; Bourdil, Charles

2017-06-01

By scattering and absorbing solar radiation, aerosols generate production losses in solar plants. Due to the specific design of solar tower plants, solar radiation is attenuated not only in the atmospheric column but also in the slant path between the heliostats and the receiver. Broadband attenuation by aerosols is estimated in both the column and the slant path for Ouarzazate, Morocco, using spectral measurements of aerosol optical thickness (AOT) collected by AERONET. The proportion of AOT below the tower's height is computed assuming a single uniform aerosol layer of height equal to the boundary layer height computed by ECMWF for the Operational Analysis. The monthly average of the broadband attenuation by aerosols in the slant path was 6.9±3.0% in August 2012 at Ouarzazate, for 1-km distance between the heliostat and the receiver. The slant path attenuation should be added to almost 40% attenuation along the atmospheric column, with aerosols in an approximate 4.7-km aerosol layer. Also, around 1.5% attenuation is caused by Rayleigh and water vapour in the slant path. The monochromatic-broadband extrapolation is validated by comparing computed and observed direct normal irradiance (DNI). DNI observed around noon varied from more than 1000 W/m2 to around 400 W/m2 at Ouarzazate in 2012 because of desert dust plumes transported from North African desert areas.

Adaptation of Dunn Solar Telescope for Jovian Doppler spectro imaging

NASA Astrophysics Data System (ADS)

Underwood, Thomas A.; Voelz, David; Schmider, François-Xavier; Jackiewicz, Jason; Dejonghe, Julien; Bresson, Yves; Hull, Robert; Goncalves, Ivan; Gualme, Patrick; Morand, Frédéric; Preis, Olivier

2017-09-01

This paper describes instrumentation used to adapt the Dunn Solar Telescope (DST) located on Sacramento Peak in Sunspot, NM for observations using the Doppler Spectro Imager (DSI). The DSI is based on a Mach-Zehnder interferometer and measures the Doppler shift of solar lines allowing for the study of atmospheric dynamics of giant planets and the detection of their acoustic oscillations. The instrumentation is being designed and built through a collaborative effort between a French team from the Observatoire de la Cote d'Azur (OCA) that designed the DSI and a US team at New Mexico State University (NMSU). There are four major components that couple the DSI to the DST: a guider/tracker, fast steering mirror (FSM), pupil stabilizer and transfer optics. The guider/tracker processes digital video to centroid-track the planet and outputs voltages to the DST's heliostat controls. The FSM removes wavefront tip/tilt components primarily due to turbulence and the pupil stabilizer removes any slow pupil "wander" introduced by the telescope's heliostat/turret arrangement. The light received at a science port of the DST is sent through the correction and stabilization components and into the DSI. The FSM and transfer optics designs are being provided by the OCA team and serve much the same functions as they do for other telescopes at which DSI observations have been conducted. The pupil stabilization and guider are new and are required to address characteristics of the DST.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karr, T.J.

The SAR energy-aperture product limit is extended to multi-beam SARS, Spotlight and moving spotlight SARS. This fundamental limit bounds the tradeoff between energy and antenna size. The kinematic relations between design variables such as platform speed, pulse repetition frequency, beam width and area rate are analyzed in a unified framework applicable to a wide variety of SARs including strip maps, spotlights, vermer arrays and multi-beam SARS, both scanning and swept-beam. Then the energy-aperture product limit is derived from the signal-to noise requirement and the kinematic constraints. The derivation clarifies impact of multiple beams and spotlighting on SAR performance.

Maintenance and suppression of chaos by weak harmonic perturbations: a unified view.

PubMed

Chacón, R

2001-02-26

General results concerning maintenance or enhancement of chaos are presented for dissipative systems subjected to two harmonic perturbations (one chaos inducing and the other chaos enhancing). The connection with previous results on chaos suppression is also discussed in a general setting. It is demonstrated that, in general, a second harmonic perturbation can reliably play an enhancer or inhibitor role by solely adjusting its initial phase. Numerical results indicate that general theoretical findings concerning periodic chaos-inducing perturbations also work for aperiodic chaos-inducing perturbations, and in arrays of identical chaotic coupled oscillators.

Detection of infrasound generated by Clear Air Turbulence (CAT)

NASA Technical Reports Server (NTRS)

Meredith, R.; Badavi, F.; Becher, J.

1981-01-01

A unified data acquisiton system which is an AM carrier system consisting of a converter signal, conditioning electronics, and peripheral equipment was checked and calibrated and installed in a mobile van. A microphone array in the shape of a 244-m equilateral triangle was connected to the data acquisition system using 457-m long cables. Development of techniques for signal processing for interpreting the infrasonic signature (differentiating between CAT and other sources of infrasound) is summarized. Once patches of CAT are located in the atmosphere, corroboration can be achieved through test flights of aircraft into the suspected region.

Unified synchronization criteria in an array of coupled neural networks with hybrid impulses.

PubMed

Wang, Nan; Li, Xuechen; Lu, Jianquan; Alsaadi, Fuad E

2018-05-01

This paper investigates the problem of globally exponential synchronization of coupled neural networks with hybrid impulses. Two new concepts on average impulsive interval and average impulsive gain are proposed to deal with the difficulties coming from hybrid impulses. By employing the Lyapunov method combined with some mathematical analysis, some efficient unified criteria are obtained to guarantee the globally exponential synchronization of impulsive networks. Our method and criteria are proved to be effective for impulsively coupled neural networks simultaneously with synchronizing impulses and desynchronizing impulses, and we do not need to discuss these two kinds of impulses separately. Moreover, by using our average impulsive interval method, we can obtain an interesting and valuable result for the case of average impulsive interval T a =∞. For some sparse impulsive sequences with T a =∞, the impulses can happen for infinite number of times, but they do not have essential influence on the synchronization property of networks. Finally, numerical examples including scale-free networks are exploited to illustrate our theoretical results. Copyright © 2018 Elsevier Ltd. All rights reserved.

Key aspects of cost effective collector and solar field design

NASA Astrophysics Data System (ADS)

von Reeken, Finn; Nicodemo, Dario; Keck, Thomas; Weinrebe, Gerhard; Balz, Markus

2016-05-01

A study has been performed where different key parameters influencing solar field cost are varied. By using levelised cost of energy as figure of merit it is shown that parameters like GoToStow wind speed, heliostat stiffness or tower height should be adapted to respective site conditions from an economical point of view. The benchmark site Redstone (Northern Cape Province, South Africa) has been compared to an alternate site close to Phoenix (AZ, USA) regarding site conditions and their effect on cost-effective collector and solar field design.

Crystal structure of isoflurane bound to integrin LFA-1 supports a unified mechanism of volatile anesthetic action in the immune and central nervous systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Hongmin; Astrof, Nathan S.; Liu, Jin-Huan

2009-09-15

Volatile anesthetics (VAs), such as isoflurane, induce a general anesthetic state by binding to specific targets (i.e., ion channels) in the central nervous system (CNS). Simultaneously, VAs modulate immune functions, possibly via direct interaction with alternative targets on leukocytes. One such target, the integrin lymphocyte function-associated antigen-1 (LFA-1), has been shown previously to be inhibited by isoflurane. A better understanding of the mechanism by which isoflurane alters protein function requires the detailed information about the drug-protein interaction at an atomic level. Here, we describe the crystal structure of the LFA-1 ligand-binding domain (I domain) in complex with isoflurane at 1.6more » {angstrom}. We discovered that isoflurane binds to an allosteric cavity previously implicated as critical for the transition of LFA-1 from the low- to the high-affinity state. The isoflurane binding site in the I domain involves an array of amphiphilic interactions, thereby resembling a 'common anesthetic binding motif' previously predicted for authentic VA binding sites. These results suggest that the allosteric modulation of protein function by isoflurane, as demonstrated for the integrin LFA-1, might represent a unified mechanism shared by the interactions of volatile anesthetics with targets in the CNS. Crystal structure of isoflurane bound to integrin LFA-1 supports a unified mechanism of volatile anesthetic action in the immune and central nervous systems.« less

Analysis of quaternary ammonium and phosphonium ionic liquids by reversed-phase high-performance liquid chromatography with charged aerosol detection and unified calibration.

PubMed

Stojanovic, Anja; Lämmerhofer, Michael; Kogelnig, Daniel; Schiesel, Simone; Sturm, Martin; Galanski, Markus; Krachler, Regina; Keppler, Bernhard K; Lindner, Wolfgang

2008-10-31

Several hydrophobic ionic liquids (ILs) based on long-chain aliphatic ammonium- and phosphonium cations and selected aromatic anions were analyzed by reversed-phase high-performance liquid chromatography (RP-HPLC) employing trifluoroacetic acid as ion-pairing additive to the acetonitrile-containing mobile phase and adopting a step-gradient elution mode. The coupling of charged aerosol detection (CAD) for the non-chromophoric aliphatic cations with diode array detection (DAD) for the aromatic anions allowed their simultaneous analysis in a set of new ILs derived from either tricaprylmethylammonium chloride (Aliquat 336) and trihexyltetradecylphosphonium chloride as precursors. Aliquat 336 is a mix of ammonium cations with distinct aliphatic chain lengths. In the course of the studies it turned out that CAD generates an identical detection response for all the distinct aliphatic cations. Due to lack of single component standards of the individual Aliquat 336 cation species, a unified calibration function was established for the quantitative analysis of the quaternary ammonium cations of the ILs. The developed method was validated according to ICH guidelines, which confirmed the validity of the unified calibration. The application of the method revealed molar ratios of cation to anion close to 1 indicating a quantitative exchange of the chloride ions of the precursors by the various aromatic anions in the course of the synthesis of new ILs. Anomalies of CAD observed for the detection of some aromatic anions (thiosalicylate and benzoate) are discussed.

The capture and recreation of 3D auditory scenes

NASA Astrophysics Data System (ADS)

Li, Zhiyun

The main goal of this research is to develop the theory and implement practical tools (in both software and hardware) for the capture and recreation of 3D auditory scenes. Our research is expected to have applications in virtual reality, telepresence, film, music, video games, auditory user interfaces, and sound-based surveillance. The first part of our research is concerned with sound capture via a spherical microphone array. The advantage of this array is that it can be steered into any 3D directions digitally with the same beampattern. We develop design methodologies to achieve flexible microphone layouts, optimal beampattern approximation and robustness constraint. We also design novel hemispherical and circular microphone array layouts for more spatially constrained auditory scenes. Using the captured audio, we then propose a unified and simple approach for recreating them by exploring the reciprocity principle that is satisfied between the two processes. Our approach makes the system easy to build, and practical. Using this approach, we can capture the 3D sound field by a spherical microphone array and recreate it using a spherical loudspeaker array, and ensure that the recreated sound field matches the recorded field up to a high order of spherical harmonics. For some regular or semi-regular microphone layouts, we design an efficient parallel implementation of the multi-directional spherical beamformer by using the rotational symmetries of the beampattern and of the spherical microphone array. This can be implemented in either software or hardware and easily adapted for other regular or semi-regular layouts of microphones. In addition, we extend this approach for headphone-based system. Design examples and simulation results are presented to verify our algorithms. Prototypes are built and tested in real-world auditory scenes.

Evaluation of Glare at the Ivanpah Solar Electric Generating System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ho, Clifford K.; Sims, Cianan; Christian, Joshua Mark

2014-07-01

The Ivanpah Solar Electric Generating System (ISEGS), located on I - 15 about 40 miles (60 km) south of Las Vegas, NV, consists of three power towers 459 ft (140 m) tall and over 170,000 reflective heliostats with a rated capacity of 390 MW. Reports of glare from the plant have been submitted by pilots and air traffic controllers and recorded by the Aviation Safety Reporting System and the California Energy Commission since 2013. Aerial and ground - based surveys of the glare were conducted in April, 2014, to identify the cause and to quantify the irradiance and potential ocularmore » impact s of the glare . Results showed that the intense glare viewed from the airspace above ISEGS was caused by he liostats in standby mode that were aimed to the side of the receiver. Evaluation of the glare showed that the retinal irradiance and subtended source angle of the glare from the heliostats in standby were sufficient to cause significant ocular impact (pot ential for after - image) up to a distance of %7E6 miles (10 km), but the values were below the threshold for permanent eye damage . Glare from the receivers had a low potential for after - image at all ground - based monitoring locations outside of the site bound aries. A Letter to Airmen has been issued by the Federal Aviation Administration to notify pilots of the potential glare hazards. Additional measures to mitigate the potential impacts of glare from ISGES are also presented and discussed. This page intentionally left blank« less

The accuracy of estimates of the overturning circulation from basin-wide mooring arrays

NASA Astrophysics Data System (ADS)

Sinha, B.; Smeed, D. A.; McCarthy, G.; Moat, B. I.; Josey, S. A.; Hirschi, J. J.-M.; Frajka-Williams, E.; Blaker, A. T.; Rayner, D.; Madec, G.

2018-01-01

Previous modeling and observational studies have established that it is possible to accurately monitor the Atlantic Meridional Overturning Circulation (AMOC) at 26.5°N using a coast-to-coast array of instrumented moorings supplemented by direct transport measurements in key boundary regions (the RAPID/MOCHA/WBTS Array). The main sources of observational and structural errors have been identified in a variety of individual studies. Here a unified framework for identifying and quantifying structural errors associated with the RAPID array-based AMOC estimates is established using a high-resolution (eddy resolving at low-mid latitudes, eddy permitting elsewhere) ocean general circulation model, which simulates the ocean state between 1978 and 2010. We define a virtual RAPID array in the model in close analogy to the real RAPID array and compare the AMOC estimate from the virtual array with the true model AMOC. The model analysis suggests that the RAPID method underestimates the mean AMOC by ∼1.5 Sv (1 Sv = 106 m3 s-1) at ∼900 m depth, however it captures the variability to high accuracy. We examine three major contributions to the streamfunction bias: (i) due to the assumption of a single fixed reference level for calculation of geostrophic transports, (ii) due to regions not sampled by the array and (iii) due to ageostrophic transport. A key element in (i) and (iii) is use of the model sea surface height to establish the true (or absolute) geostrophic transport. In the upper 2000 m, we find that the reference level bias is strongest and most variable in time, whereas the bias due to unsampled regions is largest below 3000 m. The ageostrophic transport is significant in the upper 1000 m but shows very little variability. The results establish, for the first time, the uncertainty of the AMOC estimate due to the combined structural errors in the measurement design and suggest ways in which the error could be reduced. Our work has applications to basin-wide circulation measurement arrays at other latitudes and in other basins as well as quantifying systematic errors in ocean model estimates of the AMOC at 26.5°N.

The control system of the 12-m medium-size telescope prototype: a test-ground for the CTA array control

NASA Astrophysics Data System (ADS)

Oya, I.; Anguner, E. A.; Behera, B.; Birsin, E.; Fuessling, M.; Lindemann, R.; Melkumyan, D.; Schlenstedt, S.; Schmidt, T.; Schwanke, U.; Sternberger, R.; Wegner, P.; Wiesand, S.

2014-07-01

The Cherenkov Telescope Array (CTA) will be the next generation ground-based very-high energy -ray observatory. CTA will consist of two arrays: one in the Northern hemisphere composed of about 20 telescopes, and the other one in the Southern hemisphere composed of about 100 telescopes, both arrays containing telescopes of different sizes and types and in addition numerous auxiliary devices. In order to provide a test-ground for the CTA array control, the steering software of the 12-m medium size telescope (MST) prototype deployed in Berlin has been implemented using the tools and design concepts under consideration to be used for the control of the CTA array. The prototype control system is implemented based on the Atacama Large Millimeter/submillimeter Array (ALMA) Common Software (ACS) control middleware, with components implemented in Java, C++ and Python. The interfacing to the hardware is standardized via the Object Linking and Embedding for Process Control Unified Architecture (OPC UA). In order to access the OPC UA servers from the ACS framework in a common way, a library has been developed that allows to tie the OPC UA server nodes, methods and events to the equivalents in ACS components. The front-end of the archive system is able to identify the deployed components and to perform the sampling of the monitoring points of each component following time and value change triggers according to the selected configurations. The back-end of the archive system of the prototype is composed by two different databases: MySQL and MongoDB. MySQL has been selected as storage of the system configurations, while MongoDB is used to have an efficient storage of device monitoring data, CCD images, logging and alarm information. In this contribution, the details and conclusions on the implementation of the control software of the MST prototype are presented.

Microbial modulation of host immunity with the small molecule phosphorylcholine.

PubMed

Clark, Sarah E; Weiser, Jeffrey N

2013-02-01

All microorganisms dependent on persistence in a host for survival rely on either hiding from or modulating host responses to infection. The small molecule phosphorylcholine, or choline phosphate (ChoP), is used for both of these purposes by a wide array of bacterial and parasitic microbes. While the mechanisms underlying ChoP acquisition and expression are diverse, a unifying theme is the use of ChoP to reduce the immune response to infection, creating an advantage for ChoP-expressing microorganisms. In this minireview, we discuss several benefits of ChoP expression during infection as well as how the immune system fights back against ChoP-expressing pathogens.

Astronomy for Everyone: Harvard's Move Toward an All-Inclusive Astronomy Lab and Telescope

NASA Astrophysics Data System (ADS)

Bieryla, Allyson

2016-01-01

Harvard University has a growing astronomy program that offers various courses to the undergraduate concentrators, secondaries and non-majors. Many of the courses involve labs that use the 16-inch DFM Clay Telescope for night-time observations and the heliostat for observing the Sun. The goal is to proactively adapt the lab and telescope facilities to accommodate all students with disabilities. The current focus is converting the labs to accommodate visually impaired students. Using tactile images and sound, the intention is to create an experience equivalent to that of a student with full sight.

The 10 MWe Solar Thermal Central Receiver Pilot Plant: Solar facilities design integration. Pilot-plant station manual (RADL Item 2-1). Volume 1: System description

NASA Astrophysics Data System (ADS)

1982-09-01

The complete Barstow Solar Pilot Plant is described. The plant requirements and general description are presented, the mechanical, electric power, and control and instrumentation systems as well as civil engineering and structural aspects and the station buildings are described. Included in the mechanical systems are the heliostats, receiver, thermal storage system, beam characterization system, steam, water, nitrogen, and compressed air systems, chemical feed system, fire protection system, drains, sumps and the waste disposal systems, and heating, ventilating, and air conditioning systems.

Airborne interferometer for atmospheric emission and solar absorption.

PubMed

Keith, D W; Dykema, J A; Hu, H; Lapson, L; Anderson, J G

2001-10-20

The interferometer for emission and solar absorption (INTESA) is an infrared spectrometer designed to study radiative transfer in the troposphere and lower stratosphere from a NASA ER-2 aircraft. The Fourier-transform spectrometer (FTS) operates from 0.7 to 50 mum with a resolution of 0.7 cm(-1). The FTS observes atmospheric thermal emission from multiple angles above and below the aircraft. A heliostat permits measurement of solar absorption spectra. INTESA's calibration system includes three blackbodies to permit in-flight assessment of radiometric error. Results suggest that the in-flight radiometric accuracy is ~0.5 K in the mid-infrared.

New PSA high concentration solar furnace SF40

NASA Astrophysics Data System (ADS)

Rodriguez, Jose; Cañadas, Inmaculada; Zarza, Eduardo

2016-05-01

A new solar furnace has been designed and built at Plataforma Solar de Almería. In this work, its main components such as heliostat, concentrator, attenuator and test table, and the method used to align them are described. Other equipment like the auxiliary systems necessary for the solar operation, vacuum chamber and gas system are outlined too. Finally, the thermal characteristics of the focus were measured during a test campaign, where different planes along the optical axis were scanned with a radiometer, and the peak flux was obtained and is presented in the last section of this report.

Dynamic experiment design regularization approach to adaptive imaging with array radar/SAR sensor systems.

PubMed

Shkvarko, Yuriy; Tuxpan, José; Santos, Stewart

2011-01-01

We consider a problem of high-resolution array radar/SAR imaging formalized in terms of a nonlinear ill-posed inverse problem of nonparametric estimation of the power spatial spectrum pattern (SSP) of the random wavefield scattered from a remotely sensed scene observed through a kernel signal formation operator and contaminated with random Gaussian noise. First, the Sobolev-type solution space is constructed to specify the class of consistent kernel SSP estimators with the reproducing kernel structures adapted to the metrics in such the solution space. Next, the "model-free" variational analysis (VA)-based image enhancement approach and the "model-based" descriptive experiment design (DEED) regularization paradigm are unified into a new dynamic experiment design (DYED) regularization framework. Application of the proposed DYED framework to the adaptive array radar/SAR imaging problem leads to a class of two-level (DEED-VA) regularized SSP reconstruction techniques that aggregate the kernel adaptive anisotropic windowing with the projections onto convex sets to enforce the consistency and robustness of the overall iterative SSP estimators. We also show how the proposed DYED regularization method may be considered as a generalization of the MVDR, APES and other high-resolution nonparametric adaptive radar sensing techniques. A family of the DYED-related algorithms is constructed and their effectiveness is finally illustrated via numerical simulations.

A Unifying Mechanistic Model of Selective Attention in Spiking Neurons

PubMed Central

Bobier, Bruce; Stewart, Terrence C.; Eliasmith, Chris

2014-01-01

Visuospatial attention produces myriad effects on the activity and selectivity of cortical neurons. Spiking neuron models capable of reproducing a wide variety of these effects remain elusive. We present a model called the Attentional Routing Circuit (ARC) that provides a mechanistic description of selective attentional processing in cortex. The model is described mathematically and implemented at the level of individual spiking neurons, with the computations for performing selective attentional processing being mapped to specific neuron types and laminar circuitry. The model is used to simulate three studies of attention in macaque, and is shown to quantitatively match several observed forms of attentional modulation. Specifically, ARC demonstrates that with shifts of spatial attention, neurons may exhibit shifting and shrinking of receptive fields; increases in responses without changes in selectivity for non-spatial features (i.e. response gain), and; that the effect on contrast-response functions is better explained as a response-gain effect than as contrast-gain. Unlike past models, ARC embodies a single mechanism that unifies the above forms of attentional modulation, is consistent with a wide array of available data, and makes several specific and quantifiable predictions. PMID:24921249

Unified model for the electromechanical coupling factor of orthorhombic piezoelectric rectangular bar with arbitrary aspect ratio

NASA Astrophysics Data System (ADS)

Rouffaud, R.; Levassort, F.; Hladky-Hennion, A.-C.

2017-02-01

Piezoelectric Single Crystals (PSC) are increasingly used in the manufacture of ultrasonic transducers and in particular for linear arrays or single element transducers. Among these PSCs, according to their microstructure and poled direction, some exhibit a mm2 symmetry. The analytical expression of the electromechanical coupling coefficient for a vibration mode along the poling direction for piezoelectric rectangular bar resonator is established. It is based on the mode coupling theory and fundamental energy ratio definition of electromechanical coupling coefficients. This unified formula for mm2 symmetry class material is obtained as a function of an aspect ratio (G) where the two extreme cases correspond to a thin plate (with a vibration mode characterized by the thickness coupling factor, kt) and a thin bar (characterized by k33'). To optimize the k33' value related to the thin bar design, a rotation of the crystallogaphic axis in the plane orthogonal to the poling direction is done to choose the highest value for PIN-PMN-PT single crystal. Finally, finite element calculations are performed to deduce resonance frequencies and coupling coefficients in a large range of G value to confirm developed analytical relations.

The readout and control system of the mid-size telescope prototype of the Cherenkov Telescope Array

NASA Astrophysics Data System (ADS)

Oya, I.; Anguner, O.; Behera, B.; Birsin, E.; Fuessling, M.; Melkumyan, D.; Schmidt, T.; Schwanke, U.; Sternberger, R.; Wegner, P.; Wiesand, S.; Cta Consortium,the

2014-06-01

The Cherenkov Telescope Array (CTA) is one of the major ground-based astronomy projects being pursued and will be the largest facility for ground-based y-ray observations ever built. CTA will consist of two arrays: one in the Northern hemisphere composed of about 20 telescopes, and the other one in the Southern hemisphere composed of about 100 telescopes, both arrays containing telescopes of different type and size. A prototype for the Mid-Size Telescope (MST) with a diameter of 12 m has been installed in Berlin and is currently being commissioned. This prototype is composed of a mechanical structure, a drive system and mirror facets mounted with powered actuators to enable active control. Five Charge-Coupled Device (CCD) cameras, and a wide set of sensors allow the evaluation of the performance of the instrument. The design of the control software is following concepts and tools under evaluation within the CTA consortium in order to provide a realistic test-bed for the middleware: 1) The readout and control system for the MST prototype is implemented with the Atacama Large Millimeter/submillimeter Array (ALMA) Common Software (ACS) distributed control middleware; 2) the OPen Connectivity-Unified Architecture (OPC UA) is used for hardware access; 3) the document oriented MongoDB database is used for an efficient storage of CCD images, logging and alarm information: and 4) MySQL and MongoDB databases are used for archiving the slow control monitoring data and for storing the operation configuration parameters. In this contribution, the details of the implementation of the control system for the MST prototype telescope are described.

Mount control system of the ASTRI SST-2M prototype for the Cherenkov Telescope Array

NASA Astrophysics Data System (ADS)

Antolini, Elisa; Tosti, Gino; Tanci, Claudio; Bagaglia, Marco; Canestrari, Rodolfo; Cascone, Enrico; Gambini, Giorgio; Nucciarelli, Giuliano; Pareschi, Giovanni; Scuderi, Salvo; Stringhetti, Luca; Busatta, Andrea; Giacomel, Stefano; Marchiori, Gianpietro; Manfrin, Cristiana; Marcuzzi, Enrico; Di Michele, Daniele; Grigolon, Carlo; Guarise, Paolo

2016-08-01

The ASTRI SST-2M telescope is an end-to-end prototype proposed for the Small Size class of Telescopes (SST) of the future Cherenkov Telescope Array (CTA). The prototype is installed in Italy at the INAF observing station located at Serra La Nave on Mount Etna (Sicily) and it was inaugurated in September 2014. This paper presents the software and hardware architecture and development of the system dedicated to the control of the mount, health, safety and monitoring systems of the ASTRI SST-2M telescope prototype. The mount control system installed on the ASTRI SST-2M telescope prototype makes use of standard and widely deployed industrial hardware and software. State of the art of the control and automation industries was selected in order to fulfill the mount related functional and safety requirements with assembly compactness, high reliability, and reduced maintenance. The software package was implemented with the Beckhoff TwinCAT version 3 environment for the software Programmable Logical Controller (PLC), while the control electronics have been chosen in order to maximize the homogeneity and the real time performance of the system. The integration with the high level controller (Telescope Control System) has been carried out by choosing the open platform communications Unified Architecture (UA) protocol, supporting rich data model while offering compatibility with the PLC platform. In this contribution we show how the ASTRI approach for the design and implementation of the mount control system has made the ASTRI SST-2M prototype a standalone intelligent machine, able to fulfill requirements and easy to be integrated in an array configuration such as the future ASTRI mini-array proposed to be installed at the southern site of the Cherenkov Telescope Array (CTA).

The effects of solarization on the performance of a gas turbine

NASA Astrophysics Data System (ADS)

Homann, Christiaan; van der Spuy, Johan; von Backström, Theodor

2016-05-01

Various hybrid solar gas turbine configurations exist. The Stellenbosch University Solar Power Thermodynamic (SUNSPOT) cycle consists of a heliostat field, solar receiver, primary Brayton gas turbine cycle, thermal storage and secondary Rankine steam cycle. This study investigates the effect of the solarization of a gas turbine on its performance and details the integration of a gas turbine into a solar power plant. A Rover 1S60 gas turbine was modelled in Flownex, a thermal-fluid system simulation and design code, and validated against a one-dimensional thermodynamic model at design input conditions. The performance map of a newly designed centrifugal compressor was created and implemented in Flownex. The effect of the improved compressor on the performance of the gas turbine was evident. The gas turbine cycle was expanded to incorporate different components of a CSP plant, such as a solar receiver and heliostat field. The solarized gas turbine model simulates the gas turbine performance when subjected to a typical variation in solar resource. Site conditions at the Helio100 solar field were investigated and the possibility of integrating a gas turbine within this system evaluated. Heat addition due to solar irradiation resulted in a decreased fuel consumption rate. The influence of the additional pressure drop over the solar receiver was evident as it leads to decreased net power output. The new compressor increased the overall performance of the gas turbine and compensated for pressure losses incurred by the addition of solar components. The simulated integration of the solarized gas turbine at Helio100 showed potential, although the solar irradiation is too little to run the gas turbine on solar heat alone. The simulation evaluates the feasibility of solarizing a gas turbine and predicts plant performance for such a turbine cycle.

High Contrast Astronomy with Starshades

NASA Astrophysics Data System (ADS)

Harness, Anthony D.

2016-09-01

One of the most important scientific discoveries to be had this century is the spectroscopic characterization of Earth-like exoplanets to determine the occurrence rate of worlds capable of supporting life and to potentially answer: are we alone in the universe? To accomplish these lofty goals requires an advancement in the technology to separate the overwhelming starlight from that of the exoplanet. I believe starshades are the key technology that will enable these discoveries within our lifetime. This dissertation work is a contribution to the advancement of starshade technology to put us on the path towards discovery. In this dissertation I present a number of suborbital methods developed for testing small-scale starshades, which include a Vertical Takeoff Vertical Landing rocket, the surface of a dry lake bed, and the heliostat of a solar telescope. The results from our high contrast observations are used to validate the optical model I developed to conduct tolerance analyses that will drive future starshade designs. The results from testing a formation flying sensor on the VTVL rocket demonstrate the rocket's potential for conducting starshade experiments in the stratosphere. This dissertation (along with [Novicki, et al. (2016)]) presents the first astronomical observations with a starshade that provide photometric measurements of stars, previously unobserved in the visible spectrum, in the proximity of Vega. These observations led to the development of a visual feedback system for the heliostat that allows us to push farther in separation and inner working angle. These high contrast observations were made using a starshade in the most flight-like configuration (in terms of Fresnel number, inner working angle, and resolution) to date. The results of this dissertation have helped demonstrate the effectiveness and practicality of starshades for starlight suppression and have outlined a path forward to further advance starshade technology through optical testing and high contrast astronomy.

A three-degree-of-freedom parallel manipulator for concentrated solar power towers: Modeling, simulation and design

NASA Astrophysics Data System (ADS)

Ghosal, Ashitava; Shyam, R. B. Ashith

2016-05-01

There is an increased thrust to harvest solar energy in India to meet increasing energy requirements and to minimize imported fossil fuels. In a solar power tower system, an array of tracking mirrors or heliostats are used to concentrate the incident solar energy on an elevated stationary receiver and then the thermal energy converted to electricity using a heat engine. The conventional method of tracking are the Azimuth-Elevation (Az-El) or Target-Aligned (T-A) mount. In both the cases, the mirror is rotated about two mutually perpendicular axes and is supported at the center using a pedestal which is fixed to the ground. In this paper, a three degree-of-freedom parallel manipulator, namely the 3-RPS, is proposed for tracking the sun in a solar power tower system. We present modeling, simulation and design of the 3-RPS parallel manipulator and show its advantages over conventional Az-El and T-A mounts. The 3-RPS manipulator consists of three rotary (R), three prismatic (P) and three spherical (S) joints and the mirror assembly is mounted at three points in contrast to the Az-El and T-A mounts. The kinematic equations for sun tracking are derived for the 3-RPS manipulator and from the simulations, we obtain the range of motion of the rotary, prismatic and spherical joints. Since the mirror assembly is mounted at three points, the wind load and self-weight are distributed and as a consequence, the deflections due to loading are smaller than in conventional mounts. It is shown that the weight of the supporting structure is between 15% and 65% less than that of conventional systems. Hence, even though one additional actuator is used, the larger area mirrors can be used and costs can be reduced.

A 10-MWe solar-thermal central-receiver pilot plant: Solar facilities design integration. Plant operating/training manual (RADL-Item 2-36)

NASA Astrophysics Data System (ADS)

1982-07-01

Plant and system level operating instructions are provided for the Barstow Solar Pilot Plant. Individual status instructions are given that identify plant conditions, process controller responsibilities, process conditions and control accuracies, operating envelopes, and operator cautions appropriate to the operating condition. Transition operating instructions identify the sequence of activities to be carried out to accomplish the indicated transition. Most transitions involve the startup or shutdown of an individual flowpath. Background information is provided on collector field operations, and the heliostat groupings and specific commands used in support receiver startup are defined.

Projected techno-economic improvements for advanced solar thermal power plants

NASA Technical Reports Server (NTRS)

Fujita, T.; Manvi, R.; Roschke, E. J.

1979-01-01

The projected characteristics of solar thermal power plants (with outputs up to 10 MWe) employing promising advanced technology subsystems/components are compared to current (or pre-1985) steam-Rankine systems. Improvements accruing to advanced technology development options are delineated. The improvements derived from advanced systems result primarily from achieving high efficiencies via solar collector systems which (1) capture a large portion of the available insolation and (2) concentrate this captured solar flux to attain high temperatures required for high heat engine/energy conversion performance. The most efficient solar collector systems employ two-axis tracking. Attractive systems include the central receiver/heliostat and the parabolic dish.

Preliminary study of a small beam-down solar tower on sub-Saharan countries

NASA Astrophysics Data System (ADS)

Ndiaye, Ahmadou; Thiam, Ababacar; Mbow, Cheikh; Stouffs, Pascal; Azilinon, Dorothé

2016-05-01

In this present work, a small Beam Down power plant is studied in the Sahel region. The preconfigured system is a field of 78 heliostats and a hyperboloid sectioned with a length rhyp = 11.72 m. The simulation made with the software SolTrace shows an efficiency of the field up to 89%. Temperatures from 675.37 K to 809.55 K are achieved and the power intercepted at the receiver input are equal to 96.57 kW, 124.53 9 kW and 98.90 kW respectively at 9 am, 1: 06 pm and 4 pm.

Techno-economic assessment of a hybrid solar receiver and combustor

NASA Astrophysics Data System (ADS)

Lim, Jin Han; Nathan, Graham; Dally, Bassam; Chinnici, Alfonso

2016-05-01

A techno-economic analysis is performed to compare two different configurations of hybrid solar thermal systems with fossil fuel backup to provide continuous electricity output. The assessment compares a Hybrid Solar Receiver Combustor (HSRC), in which the functions of a solar cavity receiver and a combustor are integrated into a single device with a reference conventional solar thermal system using a regular solar cavity receiver with a backup boiler, termed the Solar Gas Hybrid (SGH). The benefits of the integration is assessed by varying the size of the storage capacity and heliostat field while maintaining the same overall thermal input to the power block.

SENER molten salt tower technology. Ouarzazate NOOR III case

NASA Astrophysics Data System (ADS)

Relloso, Sergio; Gutiérrez, Yolanda

2017-06-01

NOOR III 150 MWe project is the evolution of Gemasolar (19.9 MWe) to large scale Molten Salt Tower plants. With more than 5 years of operational experience, Gemasolar lessons learned have been the starting point for the optimization of this technology, considered the leader of potential cost reduction in CSP. In addition, prototypes of plant key components (heliostat and receiver) were manufactured and thoroughly tested before project launch in order to prove the new engineering solutions adopted. The SENER proprietary technology of NOOR III will be applied in the next Molten Salt Tower plants that will follow in other countries, such as South Africa, Chile and Australia.

Variant calling in low-coverage whole genome sequencing of a Native American population sample.

PubMed

Bizon, Chris; Spiegel, Michael; Chasse, Scott A; Gizer, Ian R; Li, Yun; Malc, Ewa P; Mieczkowski, Piotr A; Sailsbery, Josh K; Wang, Xiaoshu; Ehlers, Cindy L; Wilhelmsen, Kirk C

2014-01-30

The reduction in the cost of sequencing a human genome has led to the use of genotype sampling strategies in order to impute and infer the presence of sequence variants that can then be tested for associations with traits of interest. Low-coverage Whole Genome Sequencing (WGS) is a sampling strategy that overcomes some of the deficiencies seen in fixed content SNP array studies. Linkage-disequilibrium (LD) aware variant callers, such as the program Thunder, may provide a calling rate and accuracy that makes a low-coverage sequencing strategy viable. We examined the performance of an LD-aware variant calling strategy in a population of 708 low-coverage whole genome sequences from a community sample of Native Americans. We assessed variant calling through a comparison of the sequencing results to genotypes measured in 641 of the same subjects using a fixed content first generation exome array. The comparison was made using the variant calling routines GATK Unified Genotyper program and the LD-aware variant caller Thunder. Thunder was found to improve concordance in a coverage dependent fashion, while correctly calling nearly all of the common variants as well as a high percentage of the rare variants present in the sample. Low-coverage WGS is a strategy that appears to collect genetic information intermediate in scope between fixed content genotyping arrays and deep-coverage WGS. Our data suggests that low-coverage WGS is a viable strategy with a greater chance of discovering novel variants and associations than fixed content arrays for large sample association analyses.

Dynamic Experiment Design Regularization Approach to Adaptive Imaging with Array Radar/SAR Sensor Systems

PubMed Central

Shkvarko, Yuriy; Tuxpan, José; Santos, Stewart

2011-01-01

We consider a problem of high-resolution array radar/SAR imaging formalized in terms of a nonlinear ill-posed inverse problem of nonparametric estimation of the power spatial spectrum pattern (SSP) of the random wavefield scattered from a remotely sensed scene observed through a kernel signal formation operator and contaminated with random Gaussian noise. First, the Sobolev-type solution space is constructed to specify the class of consistent kernel SSP estimators with the reproducing kernel structures adapted to the metrics in such the solution space. Next, the “model-free” variational analysis (VA)-based image enhancement approach and the “model-based” descriptive experiment design (DEED) regularization paradigm are unified into a new dynamic experiment design (DYED) regularization framework. Application of the proposed DYED framework to the adaptive array radar/SAR imaging problem leads to a class of two-level (DEED-VA) regularized SSP reconstruction techniques that aggregate the kernel adaptive anisotropic windowing with the projections onto convex sets to enforce the consistency and robustness of the overall iterative SSP estimators. We also show how the proposed DYED regularization method may be considered as a generalization of the MVDR, APES and other high-resolution nonparametric adaptive radar sensing techniques. A family of the DYED-related algorithms is constructed and their effectiveness is finally illustrated via numerical simulations. PMID:22163859

General slip regime permeability model for gas flow through porous media

NASA Astrophysics Data System (ADS)

Zhou, Bo; Jiang, Peixue; Xu, Ruina; Ouyang, Xiaolong

2016-07-01

A theoretical effective gas permeability model was developed for rarefied gas flow in porous media, which holds over the entire slip regime with the permeability derived as a function of the Knudsen number. This general slip regime model (GSR model) is derived from the pore-scale Navier-Stokes equations subject to the first-order wall slip boundary condition using the volume-averaging method. The local closure problem for the volume-averaged equations is studied analytically and numerically using a periodic sphere array geometry. The GSR model includes a rational fraction function of the Knudsen number which leads to a limit effective permeability as the Knudsen number increases. The mechanism for this behavior is the viscous fluid inner friction caused by converging-diverging flow channels in porous media. A linearization of the GSR model leads to the Klinkenberg equation for slightly rarefied gas flows. Finite element simulations show that the Klinkenberg model overestimates the effective permeability by as much as 33% when a flow approaches the transition regime. The GSR model reduces to the unified permeability model [F. Civan, "Effective correlation of apparent gas permeability in tight porous media," Transp. Porous Media 82, 375 (2010)] for the flow in the slip regime and clarifies the physical significance of the empirical parameter b in the unified model.

Seismic array processing and computational infrastructure for improved monitoring of Alaskan and Aleutian seismicity and volcanoes

NASA Astrophysics Data System (ADS)

Lindquist, Kent Gordon

We constructed a near-real-time system, called Iceworm, to automate seismic data collection, processing, storage, and distribution at the Alaska Earthquake Information Center (AEIC). Phase-picking, phase association, and interprocess communication components come from Earthworm (U.S. Geological Survey). A new generic, internal format for digital data supports unified handling of data from diverse sources. A new infrastructure for applying processing algorithms to near-real-time data streams supports automated information extraction from seismic wavefields. Integration of Datascope (U. of Colorado) provides relational database management of all automated measurements, parametric information for located hypocenters, and waveform data from Iceworm. Data from 1997 yield 329 earthquakes located by both Iceworm and the AEIC. Of these, 203 have location residuals under 22 km, sufficient for hazard response. Regionalized inversions for local magnitude in Alaska yield Msb{L} calibration curves (logAsb0) that differ from the Californian Richter magnitude. The new curve is 0.2\\ Msb{L} units more attenuative than the Californian curve at 400 km for earthquakes north of the Denali fault. South of the fault, and for a region north of Cook Inlet, the difference is 0.4\\ Msb{L}. A curve for deep events differs by 0.6\\ Msb{L} at 650 km. We expand geographic coverage of Alaskan regional seismic monitoring to the Aleutians, the Bering Sea, and the entire Arctic by initiating the processing of four short-period, Alaskan seismic arrays. To show the array stations' sensitivity, we detect and locate two microearthquakes that were missed by the AEIC. An empirical study of the location sensitivity of the arrays predicts improvements over the Alaskan regional network that are shown as map-view contour plots. We verify these predictions by detecting an Msb{L} 3.2 event near Unimak Island with one array. The detection and location of four representative earthquakes illustrates the expansion of geographic coverage from array processing. Measurements at the arrays of systematic azimuth residuals, between 5sp° and 50sp° from 203 Aleutian events, reveal significant effects of heterogeneous structure on wavefields. Finally, algorithms to automatically detect earthquakes in continuous array data are demonstrated with the detection of an Aleutian earthquake.

Applications of airborne ultrasound in human-computer interaction.

PubMed

Dahl, Tobias; Ealo, Joao L; Bang, Hans J; Holm, Sverre; Khuri-Yakub, Pierre

2014-09-01

Airborne ultrasound is a rapidly developing subfield within human-computer interaction (HCI). Touchless ultrasonic interfaces and pen tracking systems are part of recent trends in HCI and are gaining industry momentum. This paper aims to provide the background and overview necessary to understand the capabilities of ultrasound and its potential future in human-computer interaction. The latest developments on the ultrasound transducer side are presented, focusing on capacitive micro-machined ultrasonic transducers, or CMUTs. Their introduction is an important step toward providing real, low-cost multi-sensor array and beam-forming options. We also provide a unified mathematical framework for understanding and analyzing algorithms used for ultrasound detection and tracking for some of the most relevant applications. Copyright © 2014. Published by Elsevier B.V.

Cotunneling and polaronic effect in granular systems

NASA Astrophysics Data System (ADS)

Ioselevich, A. S.; Sivak, V. V.

2017-06-01

We theoretically study the conductivity in arrays of metallic grains due to the variable-range multiple cotunneling of electrons with short-range (screened) Coulomb interaction. The system is supposed to be coupled to random stray charges in the dielectric matrix that are only loosely bounded to their spatial positions by elastic forces. The flexibility of the stray charges gives rise to a polaronic effect, which leads to the onset of Arrhenius-type conductivity behavior at low temperatures, replacing conventional Mott variable-range hopping. The effective activation energy logarithmically depends on temperature due to fluctuations of the polaron barrier heights. We present the unified theory that covers both weak and strong polaron effect regimes of hopping in granular metals and describes the crossover from elastic to inelastic cotunneling.

Core questions in domestication research

PubMed Central

Zeder, Melinda A.

2015-01-01

The domestication of plants and animals is a key transition in human history, and its profound and continuing impacts are the focus of a broad range of transdisciplinary research spanning the physical, biological, and social sciences. Three central aspects of domestication that cut across and unify this diverse array of research perspectives are addressed here. Domestication is defined as a distinctive coevolutionary, mutualistic relationship between domesticator and domesticate and distinguished from related but ultimately different processes of resource management and agriculture. The relative utility of genetic, phenotypic, plastic, and contextual markers of evolving domesticatory relationships is discussed. Causal factors are considered, and two leading explanatory frameworks for initial domestication of plants and animals, one grounded in optimal foraging theory and the other in niche-construction theory, are compared. PMID:25713127

Generalized look-ahead number conversion from signed digit to complement representation with optical logic operations

NASA Astrophysics Data System (ADS)

Qian, Feng; Li, Guoqiang

2001-12-01

In this paper a generalized look-ahead logic algorithm for number conversion from signed-digit to its complement representation is developed. By properly encoding the signed digits, all the operations are performed by binary logic, and unified logical expressions can be obtained for conversion from modified-signed-digit (MSD) to 2's complement, trinary signed-digit (TSD) to 3's complement, and quaternary signed-digit (QSD) to 4's complement. For optical implementation, a parallel logical array module using electron-trapping device is employed, which is suitable for realizing complex logic functions in the form of sum-of-product. The proposed algorithm and architecture are compatible with a general-purpose optoelectronic computing system.

High-resolution Interferometric Observations of Nova RS Ophiuchi and a Proposed Unification Model for Persistent Dust Creation in Recurrent Novae

NASA Astrophysics Data System (ADS)

Barry, R. K.; Danchi, W. C.

2008-12-01

We review observations of nova RS Ophiuchi using long-baseline near-infrared and mid-infrared interferometry at three observatories: the Keck Interferometer in the Nulling mode (KIN), the Palomar Testbed Interferometer (PTI), and the Infrared and Optical Telescope Array (IOTA). We discuss these observations in the context of a unifying model of the system that includes an increase in density in the plane of the orbit of the two stars created by a spiral shock wave caused by the motion of the stars through the cool wind of the red giant star. We discuss how recent observations using the Spitzer Space Telescope and the VLTI support this proposed model.

Survey of power tower technology

NASA Astrophysics Data System (ADS)

Hildebrandt, A. F.; Dasgupta, S.

1980-05-01

The history of the power tower programs is reviewed, and attention is given to the current state of heliostat, receiver, and storage design. Economic considerations are discussed, as are simulation studies and implications. Also dealt with are alternate applications for the power tower and some financing and energy aspects of solar electric conversion. It is noted that with a national commitment to solar energy, the power tower concept could generate 40 GW of electricity and double this amount in process heat by the year 2000. Calculations show an energy amplification factor of 20 for solar energy plants; that is, the ratio of the electric energy produced over the lifetime of a power plant to the thermal energy required to produce the plant.

Saguaro power plant solar repowering project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1980-03-01

The subsystem characteristics, design requirements, and system environmental requirements for the Saguaro Power Plant Solar Repowering Project are defined. The plant conceptual design, performance, and economic data to be provided for the solar additions are identified as well as certain design data for the existing plant. All of the 115 MWe net No. 1 steam-Rankine unit of the Saguaro station is to be repowered. The receiver heat transport fluid is draw salt (60% sodium nitrate and 40% potassium nitrate) that is also used to provide 4 hours of sensible heat storage. The receiver is quad-cavity type, and there is amore » field of 10,500 second generation heliostats. (LEW)« less

Saguaro Power Plant Solar Repowering Project. Volume II. System requirements specification. Final technical report, September 1979-July 1980

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weber, E.R.

1980-07-01

This specification defines the system and subsystem characteristics, design requirements, and system environmental requirements for the Saguaro Power Plant Solar Repowering Project. This project involves the solar repowering of all (120.2 MWe gross) of the 115 MWe net power No. One steam-Rankine unit of the Arizona Public Service Company's Saguaro station. The receiver heat transport fluid is draw salt (60% sodium nitrate and 40% potassium nitrate) that is also used to provide 3.8 hours of sensible heat thermal energy storage. The quad-cavity type receiver is mounted on a tower within a single surrounding collector field of 10,500 second generation heliostats.

Astrocytic autoantibody of neuromyelitis optica (NMO-IgG) binds to aquaporin-4 extracellular loops, monomers, tetramers and high order arrays

PubMed Central

Iorio, Raffaele; Fryer, James P.; Hinson, Shannon R.; Fallier-Becker, Petra; Wolburg, Hartwig; Pittock, Sean J.; Lennon, Vanda A.

2012-01-01

The principal central nervous system (CNS) water channel, aquaporin-4 (AQP4), is confined to astrocytic and ependymal membranes and is the target of a pathogenic autoantibody, neuromyelitis optica (NMO)-IgG. This disease-specific autoantibody unifies a spectrum of relapsing CNS autoimmune inflammatory disorders of which NMO exemplifies the classic phenotype. Multiple sclerosis and other immune-mediated demyelinating disorders of the CNS lack a distinctive biomarker. Two AQP4 isoforms, M1 and M23, exist as homotetrameric and heterotetrameric intramembranous particles (IMPs). Orthogonal arrays of predominantly M23 particles (OAPs) are an ultrastructural characteristic of astrocytic membranes. We used high-titered serum from 32 AQP4-IgG-seropositive patients and 85 controls to investigate the nature and molecular location of AQP4 epitopes that bind NMO-IgG, and the influence of supramolecular structure. NMO-IgG bound to denatured AQP4 monomers (68% of cases), to native tetramers and high order arrays (90% of cases), and to AQP4 in live cell membranes (100% of cases). Disease-specific epitopes reside in extracellular loop C more than in loops A or E. IgG binding to intracellular epitopes lacks disease specificity. These observations predict greater disease specificity and sensitivity for tissue-based and cell-based serological assays employing “native” AQP4 than assays employing denatured AQP4 and fragments. NMO-IgG binds most avidly to plasma membrane surface AQP4 epitopes formed by loop interactions within tetramers and by intermolecular interactions within high order structures. The relative abundance and localization of AQP4 high order arrays in distinct CNS regions may explain the variability in clinical phenotype of NMO spectrum disorders. PMID:22906356

Stronger net posterior cortical forces and asymmetric microtubule arrays produce simultaneous centration and rotation of the pronuclear complex in the early Caenorhabditis elegans embryo

PubMed Central

Coffman, Valerie C.; McDermott, Matthew B. A.; Shtylla, Blerta; Dawes, Adriana T.

2016-01-01

Positioning of microtubule-organizing centers (MTOCs) incorporates biochemical and mechanical cues for proper alignment of the mitotic spindle and cell division site. Current experimental and theoretical studies in the early Caenorhabditis elegans embryo assume remarkable changes in the origin and polarity of forces acting on the MTOCs. These changes must occur over a few minutes, between initial centration and rotation of the pronuclear complex and entry into mitosis, and the models do not replicate in vivo timing of centration and rotation. Here we propose a model that incorporates asymmetry in the microtubule arrays generated by each MTOC, which we demonstrate with in vivo measurements, and a similar asymmetric force profile to that required for posterior-directed spindle displacement during mitosis. We find that these asymmetries are capable of and important for recapitulating the simultaneous centration and rotation of the pronuclear complex observed in vivo. The combination of theoretical and experimental evidence provided here offers a unified framework for the spatial organization and forces needed for pronuclear centration, rotation, and spindle displacement in the early C. elegans embryo. PMID:27733624

Impinging Water Droplets on Inclined Glass Surfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Armijo, Kenneth Miguel; Lance, Blake; Ho, Clifford K.

Multiphase computational models and tests of falling water droplets on inclined glass surfaces were developed to investigate the physics of impingement and potential of these droplets to self-clean glass surfaces for photovoltaic modules and heliostats. A multiphase volume-of-fluid model was developed in ANSYS Fluent to simulate the impinging droplets. The simulations considered different droplet sizes (1 mm and 3 mm), tilt angles (0°, 10°, and 45°), droplet velocities (1 m/s and 3 m/s), and wetting characteristics (wetting=47° contact angle and non-wetting = 93° contact angle). Results showed that the spread factor (maximum droplet diameter during impact divided by the initialmore » droplet diameter) decreased with increasing inclination angle due to the reduced normal force on the surface. The hydrophilic surface yielded greater spread factors than the hydrophobic surface in all cases. With regard to impact forces, the greater surface tilt angles yielded lower normal forces, but higher shear forces. Experiments showed that the experimentally observed spread factor (maximum droplet diameter during impact divided by the initial droplet diameter) was significantly larger than the simulated spread factor. Observed spread factors were on the order of 5 - 6 for droplet velocities of ~3 m/s, whereas the simulated spread factors were on the order of 2. Droplets were observed to be mobile following impact only for the cases with 45° tilt angle, which matched the simulations. An interesting phenomenon that was observed was that shortly after being released from the nozzle, the water droplet oscillated (like a trampoline) due to the "snapback" caused by the surface tension of the water droplet being released from the nozzle. This oscillation impacted the velocity immediately after the release. Future work should evaluate the impact of parameters such as tilt angle and surface wettability on the impact of particle/soiling uptake and removal to investigate ways that photovoltaic modules and heliostats can be designed to maximize self-cleaning.« less

Visibility and Visual Characteristics of the Ivanpah Solar Electric Generating System Power Tower Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sullivan, Robert; Abplanalp, Jennifer M.

2015-03-01

This report presents the results of a study conducted to document the visibility and visual characteristics of the Ivanpah Solar Electric Generating System (ISEGS), a utility-scale solar power tower facility located on land administered by the U.S. Department of the Interior Bureau of Land Management in southern California. Study activities consisted of field observations of the ISEGS facility and comparison of the observations made in the field with the visual contrast assessments and visual simulations in the ISEGS Final Environmental Impact Statement (Final EIS) and supporting documents created prior to ISEGS construction. Field observations of ISEGS were made from 19more » locations within 35 mi (56 km) of the facility in the course of one week in September 2014. The study results established that reflected sunlight from the receivers was the primary source of visual contrast from the operating ISEGS facility. The ISEGS facility was found to be a major source of visual contrast for all observations up to 20 mi (32 km), and was easily visible at 35 mi. Glare from individual heliostats was frequently visible, and often brighter than the reflected light from the receivers. Heliostat glare caused discomfort for one or more viewers at distances up to 20 mi. The ISEGS power blocks were brightly lit at night, and were conspicuous at the observation distance of approximately 6 mi (10 km). The facility is substantially brighter and is seen more clearly in the field than in photographs of the facility or in the prepared simulations, which were based on photographs. The simulations of the ISEGS facility in the Final EIS, which were evaluated as part of this study, sometimes lacked spatial accuracy and realism. The evaluated simulations generally under-represented the actual visual contrast from the project, and some of the contrast ratings in the Final EIS predicted substantially lower levels of visual contrast than were actually observed for the operating facility.« less

Adaptive correlation filter-based video stabilization without accumulative global motion estimation

NASA Astrophysics Data System (ADS)

Koh, Eunjin; Lee, Chanyong; Jeong, Dong Gil

2014-12-01

We present a digital video stabilization approach that provides both robustness and efficiency for practical applications. In this approach, we adopt a stabilization model that maintains spatio-temporal information of past input frames efficiently and can track original stabilization position. Because of the stabilization model, the proposed method does not need accumulative global motion estimation and can recover the original position even if there is a failure in interframe motion estimation. It can also intelligently overcome the situation of damaged or interrupted video sequences. Moreover, because it is simple and suitable to parallel scheme, we implement it on a commercial field programmable gate array and a graphics processing unit board with compute unified device architecture in a breeze. Experimental results show that the proposed approach is both fast and robust.

Code conversion from signed-digit to complement representation based on look-ahead optical logic operations

NASA Astrophysics Data System (ADS)

Li, Guoqiang; Qian, Feng

2001-11-01

We present, for the first time to our knowledge, a generalized lookahead logic algorithm for number conversion from signed-digit to complement representation. By properly encoding the signed-digits, all the operations are performed by binary logic, and unified logical expressions can be obtained for conversion from modified-signed- digit (MSD) to 2's complement, trinary signed-digit (TSD) to 3's complement, and quarternary signed-digit (QSD) to 4's complement. For optical implementation, a parallel logical array module using an electron-trapping device is employed and experimental results are shown. This optical module is suitable for implementing complex logic functions in the form of the sum of the product. The algorithm and architecture are compatible with a general-purpose optoelectronic computing system.

A Method to Assess Flux Hazards at CSP Plants to Reduce Avian Mortality

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ho, Clifford K.; Wendelin, Timothy; Horstman, Luke

A method to evaluate avian flux hazards at concentrating solar power plants (CSP) has been developed. A heat-transfer model has been coupled to simulations of the irradiance in the airspace above a CSP plant to determine the feather temperature along prescribed bird flight paths. Probabilistic modeling results show that the irradiance and assumed feather properties (thickness, absorptance, heat capacity) have the most significant impact on the simulated feather temperature, which can increase rapidly (hundreds of degrees Celsius in seconds) depending on the parameter values. The avian flux hazard model is being combined with a plant performance model to identify alternativemore » heliostat standby aiming strategies that minimize both avian flux hazards and negative impacts on plant performance.« less

Method of making reflecting film reflector

DOEpatents

Cottingham, James G.

1980-01-01

A reflector of the reflecting film type is disclosed and which may be used in a heliostatic system for concentrating solar energy and comprising a reflecting film bonded to an appropriate rigid substrate in such a way that specularity of a very high order is achieved. A method of bonding the reflecting film to the substrate is also disclosed and comprises the steps of initially adhering the film to a smooth, clean flat rigid surface with a non-bonding liquid between the rigid surface and film, and then bonding the substrate and film. The non-bonding liquid has a molecular adhesion greater than any stresses due to handling or curing of the bonding agent which is applied between the film and the opposing surface of the rigid substrate.

An analytical and experimental evaluation of a Fresnel lens solar concentrator

NASA Technical Reports Server (NTRS)

Hastings, L. J.; Allums, S. A.; Cosby, R. M.

1976-01-01

An analytical and experimental evaluation of line focusing Fresnel lenses with application potential in the 200 to 370 C range was studied. Analytical techniques were formulated to assess the solar transmission and imaging properties of a grooves down lens. Experimentation was based on a 56 cm wide, f/1.0 lens. A Sun tracking heliostat provided a nonmoving solar source. Measured data indicated more spreading at the profile base than analytically predicted, resulting in a peak concentration 18 percent lower than the computed peak of 57. The measured and computed transmittances were 85 and 87 percent, respectively. Preliminary testing with a subsequent lens indicated that modified manufacturing techniques corrected the profile spreading problem and should enable improved analytical experimental correlation.

Electronic systems for the new multichannel spectrometer at Sacramento Peak.

NASA Technical Reports Server (NTRS)

Hobbs, R. W.; Harris, G. D.; Epstein, G.

1972-01-01

Description of the design features and operation of a new multichannel solar spectrometer to be used for ground-based observations of active regions whose X-ray and EUV emissions are studied by the OSO-H and other satellites. The electronic systems associated with the instrument include (1) an electrooptical guider controlled by a punched paper tape capable of making raster scans of selected portions of the solar disk, (2) a programmer unit that applies paper-tape commands to various portions of the instrument, (3) a closed-loop servosystem for the vacuum heliostat, (4) stepping motor controls for spectral scans, (5) a 40-channel photomultiplier readout, and (6) a magnetometer. Preliminary solar observations indicate satisfactory performance of the system.

A method to assess flux hazards at CSP plants to reduce avian mortality

NASA Astrophysics Data System (ADS)

Ho, Clifford K.; Wendelin, Timothy; Horstman, Luke; Yellowhair, Julius

2017-06-01

A method to evaluate avian flux hazards at concentrating solar power plants (CSP) has been developed. A heat-transfer model has been coupled to simulations of the irradiance in the airspace above a CSP plant to determine the feather temperature along prescribed bird flight paths. Probabilistic modeling results show that the irradiance and assumed feather properties (thickness, absorptance, heat capacity) have the most significant impact on the simulated feather temperature, which can increase rapidly (hundreds of degrees Celsius in seconds) depending on the parameter values. The avian flux hazard model is being combined with a plant performance model to identify alternative heliostat standby aiming strategies that minimize both avian flux hazards and negative impacts on plant performance.

An analytical and experimental evaluation of the plano-cylindrical Fresnel lens solar concentrator

NASA Technical Reports Server (NTRS)

Hastings, L. J.; Allums, S. L.; Cosby, R. M.

1976-01-01

Plastic Fresnel lenses for solar concentration are attractive because of potential for low-cost mass production. An analytical and experimental evaluation of line-focusing Fresnel lenses with application potential in the 200 to 370 C range is reported. Analytical techniques were formulated to assess the solar transmission and imaging properties of a grooves-down lens. Experimentation was based primarily on a 56 cm-wide lens with f-number 1.0. A sun-tracking heliostat provided a non-moving solar source. Measured data indicated more spreading at the profile base than analytically predicted. The measured and computed transmittances were 85 and 87% respectively. Preliminary testing with a second lens (1.85 m) indicated that modified manufacturing techniques corrected the profile spreading problem.

24 CFR 578.11 - Unified Funding Agency.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 24 Housing and Urban Development 3 2014-04-01 2013-04-01 true Unified Funding Agency. 578.11... of Care § 578.11 Unified Funding Agency. (a) Becoming a Unified Funding Agency. To become designated as the Unified Funding Agency (UFA) for a Continuum, a collaborative applicant must be selected by...

Front-End Board with Cyclone V as a Test High-Resolution Platform for the Auger_Beyond_2015 Front End Electronics

NASA Astrophysics Data System (ADS)

Szadkowski, Zbigniew

2015-06-01

The surface detector (SD) array of the Pierre Auger Observatory needs an upgrade which allows space for more complex triggers with higher bandwidth and greater dynamic range. To this end this paper presents a front-end board (FEB) with the largest Cyclone V E FPGA 5CEFA9F31I7N. It supports eight channels sampled with max. 250 MSps@14-bit resolution. Considered sampling for the SD is 120 MSps; however, the FEB has been developed with external anti-aliasing filters to retain maximal flexibility. Six channels are targeted at the SD, two are reserved for other experiments like: Auger Engineering Radio Array and additional muon counters. The FEB is an intermediate design plugged into a unified board communicating with a micro-controller at 40 MHz; however, it provides 250 MSPs sampling with an 18-bit dynamic range, is equipped with a virtual NIOS processor and supports 256 MB of SDRAM as well as an implemented spectral trigger based on the discrete cosine transform for detection of very inclined “old” showers. The FEB can also support neural network development for detection of “young” showers, potentially generated by neutrinos. A single FEB was already tested in the Auger surface detector in Malargüe (Argentina) for 120 and 160 MSps. Preliminary tests showed perfect stability of data acquisition for sampling frequency three or four times greater. They allowed optimization of the design before deployment of seven or eight FEBs for several months of continuous tests in the engineering array.

The ICT monitoring system of the ASTRI SST-2M prototype proposed for the Cherenkov Telescope Array

NASA Astrophysics Data System (ADS)

Gianotti, F.; Bruno, P.; Tacchini, A.; Conforti, V.; Fioretti, V.; Tanci, C.; Grillo, A.; Leto, G.; Malaguti, G.; Trifoglio, M.

2016-08-01

In the framework of the international Cherenkov Telescope Array (CTA) observatory, the Italian National Institute for Astrophysics (INAF) has developed a dual mirror, small sized, telescope prototype (ASTRI SST-2M), installed in Italy at the INAF observing station located at Serra La Nave, Mt. Etna. The ASTRI SST-2M prototype is the basis of the ASTRI telescopes that will form the mini-array proposed to be installed at the CTA southern site during its preproduction phase. This contribution presents the solutions implemented to realize the monitoring system for the Information and Communication Technology (ICT) infrastructure of the ASTRI SST-2M prototype. The ASTRI ICT monitoring system has been implemented by integrating traditional tools used in computer centers, with specific custom tools which interface via Open Platform Communication Unified Architecture (OPC UA) to the Alma Common Software (ACS) that is used to operate the ASTRI SST-2M prototype. The traditional monitoring tools are based on Simple Network Management Protocol (SNMP) and commercial solutions and features embedded in the devices themselves. They generate alerts by email and SMS. The specific custom tools convert the SNMP protocol into the OPC UA protocol and implement an OPC UA server. The server interacts with an OPC UA client implemented in an ACS component that, through the ACS Notification Channel, sends monitor data and alerts to the central console of the ASTRI SST-2M prototype. The same approach has been proposed also for the monitoring of the CTA onsite ICT infrastructures.

Imaging black holes: past, present and future

NASA Astrophysics Data System (ADS)

Falcke, Heino

2017-12-01

This paper briefly reviews past, current, and future efforts to image black holes. Black holes seem like mystical objects, but they are an integral part of current astrophysics and are at the center of attempts to unify quantum physics and general relativity. Yet, nobody has ever seen a black hole. What do they look like? Initially, this question seemed more of an academic nature. However, this has changed over the past two decades. Observations and theoretical considerations suggest that the supermassive black hole, Sgr A*, in the center of our Milky Way is surrounded by a compact, foggy emission region radiating at and above 230 GHz. It has been predicted that the event horizon of Sgr A* should cast its shadow onto that emission region, which could be detectable with a global VLBI array of radio telescopes. In contrast to earlier pictures of black holes, that dark feature is not supposed to be due to a hole in the accretion flow, but would represent a true negative image of the event horizon. Currently, the global Event Horizon Telescope consortium is attempting to make such an image. In the future those images could be improved by adding more telescopes to the array, in particular at high sites in Africa. Ultimately, a space array at THz frequencies, the Event Horizon Imager, could produce much more detailed images of black holes. In combination with numerical simulations and precise measurements of the orbits of stars - ideally also of pulsars - these images will allow us to study black holes with unprecedented precision.

An Integrated Analysis of the Physiological Effects of Space Flight: Executive Summary

NASA Technical Reports Server (NTRS)

Leonard, J. I.

1985-01-01

A large array of models were applied in a unified manner to solve problems in space flight physiology. Mathematical simulation was used as an alternative way of looking at physiological systems and maximizing the yield from previous space flight experiments. A medical data analysis system was created which consist of an automated data base, a computerized biostatistical and data analysis system, and a set of simulation models of physiological systems. Five basic models were employed: (1) a pulsatile cardiovascular model; (2) a respiratory model; (3) a thermoregulatory model; (4) a circulatory, fluid, and electrolyte balance model; and (5) an erythropoiesis regulatory model. Algorithms were provided to perform routine statistical tests, multivariate analysis, nonlinear regression analysis, and autocorrelation analysis. Special purpose programs were prepared for rank correlation, factor analysis, and the integration of the metabolic balance data.

The momentum transfer of incompressible turbulent separated flow due to cavities with steps

NASA Technical Reports Server (NTRS)

White, R. E.; Norton, D. J.

1977-01-01

An experimental study was conducted using a plate test bed having a turbulent boundary layer to determine the momentum transfer to the faces of step/cavity combinations on the plate. Experimental data were obtained from configurations including an isolated configuration and an array of blocks in tile patterns. A momentum transfer correlation model of pressure forces on an isolated step/cavity was developed with experimental results to relate flow and geometry parameters. Results of the experiments reveal that isolated step/cavity excrecences do not have a unique and unifying parameter group due in part to cavity depth effects and in part to width parameter scale effects. Drag predictions for tile patterns by a kinetic pressure empirical method predict experimental results well. Trends were not, however, predicted by a method of variable roughness density phenomenology.

Valley Topological Phases in Bilayer Sonic Crystals

NASA Astrophysics Data System (ADS)

Lu, Jiuyang; Qiu, Chunyin; Deng, Weiyin; Huang, Xueqin; Li, Feng; Zhang, Fan; Chen, Shuqi; Liu, Zhengyou

2018-03-01

Recently, the topological physics in artificial crystals for classical waves has become an emerging research area. In this Letter, we propose a unique bilayer design of sonic crystals that are constructed by two layers of coupled hexagonal array of triangular scatterers. Assisted by the additional layer degree of freedom, a rich topological phase diagram is achieved by simply rotating scatterers in both layers. Under a unified theoretical framework, two kinds of valley-projected topological acoustic insulators are distinguished analytically, i.e., the layer-mixed and layer-polarized topological valley Hall phases, respectively. The theory is evidently confirmed by our numerical and experimental observations of the nontrivial edge states that propagate along the interfaces separating different topological phases. Various applications such as sound communications in integrated devices can be anticipated by the intriguing acoustic edge states enriched by the layer information.

Scaling macroscopic aquatic locomotion

NASA Astrophysics Data System (ADS)

Gazzola, Mattia; Argentina, Mederic; Mahadevan, Lakshminarayanan

2014-11-01

Inertial aquatic swimmers that use undulatory gaits range in length L from a few millimeters to 30 meters, across a wide array of biological taxa. Using elementary hydrodynamic arguments, we uncover a unifying mechanistic principle characterizing their locomotion by deriving a scaling relation that links swimming speed U to body kinematics (tail beat amplitude A and frequency ω) and fluid properties (kinematic viscosity ν). This principle can be simply couched as the power law Re ~ Swα , where Re = UL / ν >> 1 and Sw = ωAL / ν , with α = 4 / 3 for laminar flows, and α = 1 for turbulent flows. Existing data from over 1000 measurements on fish, amphibians, larvae, reptiles, mammals and birds, as well as direct numerical simulations are consistent with our scaling. We interpret our results as the consequence of the convergence of aquatic gaits to the performance limits imposed by hydrodynamics.

Scaling macroscopic aquatic locomotion

NASA Astrophysics Data System (ADS)

Gazzola, Mattia; Argentina, Médéric; Mahadevan, L.

2014-10-01

Inertial aquatic swimmers that use undulatory gaits range in length L from a few millimetres to 30 metres, across a wide array of biological taxa. Using elementary hydrodynamic arguments, we uncover a unifying mechanistic principle characterizing their locomotion by deriving a scaling relation that links swimming speed U to body kinematics (tail beat amplitude A and frequency ω) and fluid properties (kinematic viscosity ν). This principle can be simply couched as the power law Re ~ Swα, where Re = UL/ν >> 1 and Sw = ωAL/ν, with α = 4/3 for laminar flows, and α = 1 for turbulent flows. Existing data from over 1,000 measurements on fish, amphibians, larvae, reptiles, mammals and birds, as well as direct numerical simulations are consistent with our scaling. We interpret our results as the consequence of the convergence of aquatic gaits to the performance limits imposed by hydrodynamics.

Exploring the Virchow–Robin spaces function: A unified theory of brain diseases

PubMed Central

Cherian, Iype; Beltran, Margarita; Kasper, Ekkehard M.; Bhattarai, Binod; Munokami, Sunil; Grasso, Giovanni

2016-01-01

Background: Cerebrospinal fluid (CSF) transport across the central nervous system (CNS) is no longer believed to be on the conventional lines. The Virchow–Robin space (VRS) that facilitates CSF transport from the basal cisterns into the brain interstitial fluid (ISF) has gained interest in a whole new array of studies. Moreover, new line of evidence suggests that VRS may be involved in different pathological mechanisms of brain diseases. Methods: Here, we review emerging studies proving the feasible role of VRS in sleep, Alzheimer's disease, chronic traumatic encephalopathy, and traumatic brain injury (TBI). Results: In this study, we have outlined the possible role of VRS in different pathological conditions. Conclusion: The new insights into the physiology of the CSF circulation may have important clinical relevance for understanding the mechanisms underlying brain pathologies and their cure. PMID:27857861

Selection of optimal spectral sensitivity functions for color filter arrays.

PubMed

Parmar, Manu; Reeves, Stanley J

2010-12-01

A color image meant for human consumption can be appropriately displayed only if at least three distinct color channels are present. Typical digital cameras acquire three-color images with only one sensor. A color filter array (CFA) is placed on the sensor such that only one color is sampled at a particular spatial location. This sparsely sampled signal is then reconstructed to form a color image with information about all three colors at each location. In this paper, we show that the wavelength sensitivity functions of the CFA color filters affect both the color reproduction ability and the spatial reconstruction quality of recovered images. We present a method to select perceptually optimal color filter sensitivity functions based upon a unified spatial-chromatic sampling framework. A cost function independent of particular scenes is defined that expresses the error between a scene viewed by the human visual system and the reconstructed image that represents the scene. A constrained minimization of the cost function is used to obtain optimal values of color-filter sensitivity functions for several periodic CFAs. The sensitivity functions are shown to perform better than typical RGB and CMY color filters in terms of both the s-CIELAB ∆E error metric and a qualitative assessment.

A bioanalytical platform for simultaneous detection and quantification of biological toxins.

PubMed

Weingart, Oliver G; Gao, Hui; Crevoisier, François; Heitger, Friedrich; Avondet, Marc-André; Sigrist, Hans

2012-01-01

Prevalent incidents support the notion that toxins, produced by bacteria, fungi, plants or animals are increasingly responsible for food poisoning or intoxication. Owing to their high toxicity some toxins are also regarded as potential biological warfare agents. Accordingly, control, detection and neutralization of toxic substances are a considerable economic burden to food safety, health care and military biodefense. The present contribution describes a new versatile instrument and related procedures for array-based simultaneous detection of bacterial and plant toxins using a bioanalytical platform which combines the specificity of covalently immobilized capture probes with a dedicated instrumentation and immuno-based microarray analytics. The bioanalytical platform consists of a microstructured polymer slide serving both as support of printed arrays and as incubation chamber. The platform further includes an easy-to-operate instrument for simultaneous slide processing at selectable assay temperature. Cy5 coupled streptavidin is used as unifying fluorescent tracer. Fluorescence image analysis and signal quantitation allow determination of the toxin's identity and concentration. The system's performance has been investigated by immunological detection of Botulinum Neurotoxin type A (BoNT/A), Staphylococcal enterotoxin B (SEB), and the plant toxin ricin. Toxins were detectable at levels as low as 0.5-1 ng · mL(-1) in buffer or in raw milk.

A Bioanalytical Platform for Simultaneous Detection and Quantification of Biological Toxins

PubMed Central

Weingart, Oliver G.; Gao, Hui; Crevoisier, François; Heitger, Friedrich; Avondet, Marc-André; Sigrist, Hans

2012-01-01

Prevalent incidents support the notion that toxins, produced by bacteria, fungi, plants or animals are increasingly responsible for food poisoning or intoxication. Owing to their high toxicity some toxins are also regarded as potential biological warfare agents. Accordingly, control, detection and neutralization of toxic substances are a considerable economic burden to food safety, health care and military biodefense. The present contribution describes a new versatile instrument and related procedures for array-based simultaneous detection of bacterial and plant toxins using a bioanalytical platform which combines the specificity of covalently immobilized capture probes with a dedicated instrumentation and immuno-based microarray analytics. The bioanalytical platform consists of a microstructured polymer slide serving both as support of printed arrays and as incubation chamber. The platform further includes an easy-to-operate instrument for simultaneous slide processing at selectable assay temperature. Cy5 coupled streptavidin is used as unifying fluorescent tracer. Fluorescence image analysis and signal quantitation allow determination of the toxin’s identity and concentration. The system’s performance has been investigated by immunological detection of Botulinum Neurotoxin type A (BoNT/A), Staphylococcal enterotoxin B (SEB), and the plant toxin ricin. Toxins were detectable at levels as low as 0.5–1 ng·mL−1 in buffer or in raw milk. PMID:22438766

MEMS deformable mirror embedded wavefront sensing and control system

NASA Astrophysics Data System (ADS)

Owens, Donald; Schoen, Michael; Bush, Keith

2006-01-01

Electrostatic Membrane Deformable Mirror (MDM) technology developed using silicon bulk micro-machining techniques offers the potential of providing low-cost, compact wavefront control systems for diverse optical system applications. Electrostatic mirror construction using bulk micro-machining allows for custom designs to satisfy wavefront control requirements for most optical systems. An electrostatic MDM consists of a thin membrane, generally with a thin metal or multi-layer high-reflectivity coating, suspended over an actuator pad array that is connected to a high-voltage driver. Voltages applied to the array elements deflect the membrane to provide an optical surface capable of correcting for measured optical aberrations in a given system. Electrostatic membrane DM designs are derived from well-known principles of membrane mechanics and electrostatics, the desired optical wavefront control requirements, and the current limitations of mirror fabrication and actuator drive electronics. MDM performance is strongly dependent on mirror diameter and air damping in meeting desired spatial and temporal frequency requirements. In this paper, we present wavefront control results from an embedded wavefront control system developed around a commercially available high-speed camera and an AgilOptics Unifi MDM driver using USB 2.0 communications and the Linux development environment. This new product, ClariFast TM, combines our previous Clarifi TM product offering into a faster more streamlined version dedicated strictly to Hartmann Wavefront sensing.

Modeling of reverberant room responses for two-dimensional spatial sound field analysis and synthesis.

PubMed

Bai, Mingsian R; Li, Yi; Chiang, Yi-Hao

2017-10-01

A unified framework is proposed for analysis and synthesis of two-dimensional spatial sound field in reverberant environments. In the sound field analysis (SFA) phase, an unbaffled 24-element circular microphone array is utilized to encode the sound field based on the plane-wave decomposition. Depending on the sparsity of the sound sources, the SFA stage can be implemented in two manners. For sparse-source scenarios, a one-stage algorithm based on compressive sensing algorithm is utilized. Alternatively, a two-stage algorithm can be used, where the minimum power distortionless response beamformer is used to localize the sources and Tikhonov regularization algorithm is used to extract the source amplitudes. In the sound field synthesis (SFS), a 32-element rectangular loudspeaker array is employed to decode the target sound field using pressure matching technique. To establish the room response model, as required in the pressure matching step of the SFS phase, an SFA technique for nonsparse-source scenarios is utilized. Choice of regularization parameters is vital to the reproduced sound field. In the SFS phase, three SFS approaches are compared in terms of localization performance and voice reproduction quality. Experimental results obtained in a reverberant room are presented and reveal that an accurate room response model is vital to immersive rendering of the reproduced sound field.

Solar Pilot Plant, Phase I. Preliminary design report. Volume II, Book 2. Central receiver optical model users manual. CDRL item 2. [HELIAKI code

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1977-05-01

HELIAKI is a FORTRAN computer program which simulates the optical/thermal performance of a central receiver solar thermal power plant for the dynamic conversion of solar-generated heat to electricity. The solar power plant which this program simulates consists of a field of individual sun tracking mirror units, or heliostats, redirecting sunlight into a cavity, called the receiver, mounted atop a tower. The program calculates the power retained by that cavity receiver at any point in time or the energy into the receiver over a year's time using a Monte Carlo ray trace technique to solve the multiple integral equations. An artist'smore » concept of this plant is shown.« less

Computer aided control of a mechanical arm

NASA Technical Reports Server (NTRS)

Derocher, W. L., Jr.; Zermuehlen, r. O.

1979-01-01

A method for computer-aided remote control of a six-degree-of-freedom manipulator arm involved in the on-orbit servicing of a spacecraft is presented. The control configuration features a supervisory type of control in which each of the segments of a module exchange trajectory is controlled automatically under human supervision, with manual commands to proceed to the next step and in the event of a failure or undesirable outcome. The implementation of the supervisory system is discussed in terms of necessary onboard and ground- or Orbiter-based hardware and software, and a one-g demonstration system built to allow further investigation of system operation is described. Possible applications of the system include the construction of satellite solar power systems, environmental testing and the control of heliostat solar power stations.

Baseload Nitrate Salt Central Receiver Power Plant Design Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tilley, Drake; Kelly, Bruce; Burkholder, Frank

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 Moltenmore » 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 manufacturing. The cost and design goals for the project were met with this task, but the most interesting results had to do with defining the failure modes and looking at a “shakedown analysis” of the combined creep-fatigue failure. A separate task also looked at improving the absorber coatings on the receiver tubes that would improve the efficiency of the receiver. Significant progress was made on developing a novel paint with a high absorptivity that was on par with the current Pyromark, but shows additional potential to be optimized further. Although the coating did not meet the emissivity goals, preliminary testing the new paint shows potential to be much more durable, and potential to improve the receiver efficiency through a higher average absorptivity over the lifetime. Additional coatings were also designed and modeled results meet the project goals, but were not tested. Testing for low cycle fatigue of the full length receiver tubes was designed and constructed, but is still currently undergoing testing. A novel small heliostat was developed through an extensive brainstorming and down select. The concept was then detailed further with inputs from component testing and eventually a full prototype was built and tested. This task met or exceeded the accuracy and structure goals and also beat the cost goal. This provides a significant solar field costs savings for Abengoa that will be developed further to be used in future commercial plants. Ultimately the $0.09/kWhe (real 2009 $) and 6,400 hours goals of the project were met.« less

A Unifying Mechanism for Cancer Cell Death through Ion Channel Activation by HAMLET

PubMed Central

Storm, Petter; Kjaer Klausen, Thomas; Trulsson, Maria; Ho CS, James; Dosnon, Marion; Westergren, Tomas; Chao, Yinxia; Rydström, Anna; Yang, Henry; Pedersen, Stine Falsig; Svanborg, Catharina

2013-01-01

Ion channels and ion fluxes control many aspects of tissue homeostasis. During oncogenic transformation, critical ion channel functions may be perturbed but conserved tumor specific ion fluxes remain to be defined. Here we used the tumoricidal protein-lipid complex HAMLET as a probe to identify ion fluxes involved in tumor cell death. We show that HAMLET activates a non-selective cation current, which reached a magnitude of 2.74±0.88 nA within 1.43±0.13 min from HAMLET application. Rapid ion fluxes were essential for HAMLET-induced carcinoma cell death as inhibitors (amiloride, BaCl2), preventing the changes in free cellular Na+ and K+ concentrations also prevented essential steps accompanying carcinoma cell death, including changes in morphology, uptake, global transcription, and MAP kinase activation. Through global transcriptional analysis and phosphorylation arrays, a strong ion flux dependent p38 MAPK response was detected and inhibition of p38 signaling delayed HAMLET-induced death. Healthy, differentiated cells were resistant to HAMLET challenge, which was accompanied by innate immunity rather than p38-activation. The results suggest, for the first time, a unifying mechanism for the initiation of HAMLET’s broad and rapid lethal effect on tumor cells. These findings are particularly significant in view of HAMLET’s documented therapeutic efficacy in human studies and animal models. The results also suggest that HAMLET offers a two-tiered therapeutic approach, killing cancer cells while stimulating an innate immune response in surrounding healthy tissues. PMID:23505537

A unifying mechanism for cancer cell death through ion channel activation by HAMLET.

PubMed

Storm, Petter; Klausen, Thomas Kjaer; Trulsson, Maria; Ho C S, James; Dosnon, Marion; Westergren, Tomas; Chao, Yinxia; Rydström, Anna; Yang, Henry; Pedersen, Stine Falsig; Svanborg, Catharina

2013-01-01

Ion channels and ion fluxes control many aspects of tissue homeostasis. During oncogenic transformation, critical ion channel functions may be perturbed but conserved tumor specific ion fluxes remain to be defined. Here we used the tumoricidal protein-lipid complex HAMLET as a probe to identify ion fluxes involved in tumor cell death. We show that HAMLET activates a non-selective cation current, which reached a magnitude of 2.74±0.88 nA within 1.43±0.13 min from HAMLET application. Rapid ion fluxes were essential for HAMLET-induced carcinoma cell death as inhibitors (amiloride, BaCl2), preventing the changes in free cellular Na(+) and K(+) concentrations also prevented essential steps accompanying carcinoma cell death, including changes in morphology, uptake, global transcription, and MAP kinase activation. Through global transcriptional analysis and phosphorylation arrays, a strong ion flux dependent p38 MAPK response was detected and inhibition of p38 signaling delayed HAMLET-induced death. Healthy, differentiated cells were resistant to HAMLET challenge, which was accompanied by innate immunity rather than p38-activation. The results suggest, for the first time, a unifying mechanism for the initiation of HAMLET's broad and rapid lethal effect on tumor cells. These findings are particularly significant in view of HAMLET's documented therapeutic efficacy in human studies and animal models. The results also suggest that HAMLET offers a two-tiered therapeutic approach, killing cancer cells while stimulating an innate immune response in surrounding healthy tissues.

3 CFR - Unified Command Plan 2011

Code of Federal Regulations, 2012 CFR

2012-01-01

... 3 The President 1 2012-01-01 2012-01-01 false Unified Command Plan 2011 Presidential Documents Other Presidential Documents Memorandum of April 6, 2011 Unified Command Plan 2011 Memorandum for the... implementation of the revised Unified Command Plan. Consistent with title 10, United States Code, section 161(b...

76 FR 76046 - Interim Final Determination To Defer Sanctions, San Joaquin Valley Unified Air Pollution Control...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-06

... Determination To Defer Sanctions, San Joaquin Valley Unified Air Pollution Control District AGENCY... Valley Unified Air Pollution Control District (SJVUAPCD or District) portion of the California State...), we finalized a limited approval and limited disapproval of San Joaquin Valley Unified Air Pollution...

76 FR 41745 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-15

... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approval and limited disapproval of revisions to the San Joaquin Valley Unified Air Pollution Control... Valley Unified Air Pollution Control District (SJVUAPCD) Rule 4682, Polystyrene, Polyethylene, and...

76 FR 68103 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-03

... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the... State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District Rule 4692...

Exome Array Analysis of Nuclear Lens Opacity.

PubMed

Loomis, Stephanie J; Klein, Alison P; Lee, Kristine E; Chen, Fei; Bomotti, Samantha; Truitt, Barbara; Iyengar, Sudha K; Klein, Ronald; Klein, Barbara E K; Duggal, Priya

2018-06-01

Nuclear cataract is the most common subtype of age-related cataract, the leading cause of blindness worldwide. It results from advanced nuclear sclerosis, or opacity in the center of the optic lens, and is affected by both genetic and environmental risk factors, including smoking. We sought to understand the genetic factors associated with nuclear sclerosis through interrogation of rare and low frequency coding variants using exome array data. We analyzed Illumina Human Exome Array data for 1,488 participants of European ancestry in the Beaver Dam Eye Study who were without cataract surgery for association with nuclear sclerosis grade, controlling for age and sex. We performed single-variant regression analysis for 32,138 variants with minor allele frequency (MAF) ≥0.003. In addition, gene-based analysis of 11,844 genes containing at least two variants with MAF < 0.05 was performed using a gene-based unified burden and non-burden sequence kernel association test (SKAT-O). Additionally, both single-variant and gene-based analyses were analyzed stratified by smoking status. No single-variant test was statistically significant after Bonferroni correction (p < 1.6 × 10 -6 ; top single nucleotide polymorphism (SNP): rs144458991, p = 2.83 × 10 -5 ). Gene-based tests were suggestively associated with the gene RNF149 overall (p = 8.29 × 10 -6 ) and among never smokers (N = 790, p = 2.67 × 10 -6 ). This study did not find a significant genetic association with nuclear sclerosis, the possible association with the RNF149 gene highlights a potential candidate gene for future studies that aim to understand the genetic architecture of nuclear sclerosis.

Project UNIFY. National Dropout Prevention Center/Network Newsletter. Volume 22, Number 1

ERIC Educational Resources Information Center

Duckenfield, Marty, Ed.

2011-01-01

The "National Dropout Prevention Newsletter" is published quarterly by the National Dropout Prevention Center/Network. This issue contains the following articles: (1) Special Olympics Project UNIFY (Andrea Cahn); (2) The Impact of Project UNIFY; (3) Project UNIFY Brings Youth Together to Learn and Graduate (William H. Hughes); (4)…

75 FR 28509 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-21

... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of... Joaquin Valley Unified Air Pollution Control District, No. 08-17309 (9th Circuit)). In that case, NAHB...

The development and test of a deformable diffraction grating for a stigmatic EUV spectroheliometer

NASA Technical Reports Server (NTRS)

Timothy, J. Gethyn; Walker, A. B. C., Jr.; Morgan, J. S.; Huber, M. C. E.; Tondello, G.

1992-01-01

The objectives were to address currently unanswered fundamental questions concerning the fine scale structure of the chromosphere, transition region, and corona. The unique characteristics of the spectroheliometer was used in combination with plasma diagnostic techniques to study the temperature, density, and velocity structures of specific features in the solar outer atmosphere. A unified understanding was sought of the interplay between the time dependent geometry of the magnetic field structure and the associated flows of mass and energy, the key to which lies in the smallest spatial scales that are unobservable with current EUV instruments. Toroidal diffraction gratings were fabricated and tested by a new technique using an elastically deformable substrate. The toroidal diffraction gratings was procured and tested to be used for the evaluation of the Multi-Anode Microchannel Array (MAMA) detector systems for the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) and UV Coronagraph Spectrometer (UVCS) instruments on the SOHO mission.

General purpose graphic processing unit implementation of adaptive pulse compression algorithms

NASA Astrophysics Data System (ADS)

Cai, Jingxiao; Zhang, Yan

2017-07-01

This study introduces a practical approach to implement real-time signal processing algorithms for general surveillance radar based on NVIDIA graphical processing units (GPUs). The pulse compression algorithms are implemented using compute unified device architecture (CUDA) libraries such as CUDA basic linear algebra subroutines and CUDA fast Fourier transform library, which are adopted from open source libraries and optimized for the NVIDIA GPUs. For more advanced, adaptive processing algorithms such as adaptive pulse compression, customized kernel optimization is needed and investigated. A statistical optimization approach is developed for this purpose without needing much knowledge of the physical configurations of the kernels. It was found that the kernel optimization approach can significantly improve the performance. Benchmark performance is compared with the CPU performance in terms of processing accelerations. The proposed implementation framework can be used in various radar systems including ground-based phased array radar, airborne sense and avoid radar, and aerospace surveillance radar.

Computational Models of Anterior Cingulate Cortex: At the Crossroads between Prediction and Effort.

PubMed

Vassena, Eliana; Holroyd, Clay B; Alexander, William H

2017-01-01

In the last two decades the anterior cingulate cortex (ACC) has become one of the most investigated areas of the brain. Extensive neuroimaging evidence suggests countless functions for this region, ranging from conflict and error coding, to social cognition, pain and effortful control. In response to this burgeoning amount of data, a proliferation of computational models has tried to characterize the neurocognitive architecture of ACC. Early seminal models provided a computational explanation for a relatively circumscribed set of empirical findings, mainly accounting for EEG and fMRI evidence. More recent models have focused on ACC's contribution to effortful control. In parallel to these developments, several proposals attempted to explain within a single computational framework a wider variety of empirical findings that span different cognitive processes and experimental modalities. Here we critically evaluate these modeling attempts, highlighting the continued need to reconcile the array of disparate ACC observations within a coherent, unifying framework.

The inability to mentally represent action may be associated with performance deficits in children with developmental coordination disorder.

PubMed

Gabbard, Carl; Bobbio, Tatiana

2011-03-01

Several research studies indicate that children with developmental coordination disorder (DCD) show delays with an array of perceptual-motor skills. One of the explanations, based on limited research, is that these children have problems generating and/or monitoring a mental (action) representation of intended actions, termed the "internal modeling deficit" (IMD) hypothesis. According to the hypothesis, children with DCD have significant limitations in their ability to accurately generate and utilize internal models of motor planning and control. The focus of this review is on one of the methods used to examine action representation-motor imagery, which theorists argue provides a window into the process of action representation (e.g., Jeannerod, 2001 . Neural simulation of action: A unifying mechanism for motor cognition. Neuroimage, 14, 103-109.). Included in the review are performance studies of typically developing and DCD children, and possible brain structures involved.

Dopamine in Drosophila: setting arousal thresholds in a miniature brain

PubMed Central

Van Swinderen, Bruno; Andretic, Rozi

2011-01-01

In mammals, the neurotransmitter dopamine (DA) modulates a variety of behaviours, although DA function is mostly associated with motor control and reward. In insects such as the fruitfly, Drosophila melanogaster, DA also modulates a wide array of behaviours, ranging from sleep and locomotion to courtship and learning. How can a single molecule play so many different roles? Adaptive changes within the DA system, anatomical specificity of action and effects on a variety of behaviours highlight the remarkable versatility of this neurotransmitter. Recent genetic and pharmacological manipulations of DA signalling in Drosophila have launched a surfeit of stories—each arguing for modulation of some aspect of the fly's waking (and sleeping) life. Although these stories often seem distinct and unrelated, there are some unifying themes underlying DA function and arousal states in this insect model. One of the central roles played by DA may involve perceptual suppression, a necessary component of both sleep and selective attention. PMID:21208962

29 CFR 779.219 - Unified operation may be achieved without common control or common ownership.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 3 2010-07-01 2010-07-01 false Unified operation may be achieved without common control or... Act May Apply; Enterprise Coverage Unified Operation Or Common Control § 779.219 Unified operation may be achieved without common control or common ownership. The performance of related activities through...

A Vision for the Future of Counseling: The 20/20 "Principles for Unifying and Strengthening the Profession"

ERIC Educational Resources Information Center

Kaplan, David M.; Gladding, Samuel T.

2011-01-01

This article describes the development of the historic "Principles for Unifying and Strengthening the Profession." An outcome of the "20/20: A Vision for the Future of Counseling" initiative, this document delineates a core set of principles that unifies and advances the counseling profession. "Principles for Unifying and Strengthening the…

Low-Cost, Light Weight, Thin Film Solar Concentrator

NASA Technical Reports Server (NTRS)

Ganapathi, G.; Palisoc, A.; Nesmith, B.; Greschik, G.; Gidanian, K.; Kindler, A.

2013-01-01

This research addresses a cost barrier towards achieving a solar thermal collector system with an installed cost of $75/sq m and meet the Department of Energy's (DOE's) performance targets for optical errors, operations during windy conditions and lifetime. Current concentrators can cost as much as 40-50% of the total installed costs for a CSP plant. In order to reduce the costs from current $200-$250/sq m, it is important to focus on the overall system. The reflector surface is a key cost driver, and our film-based polymer reflector will help significantly in achieving DOE's cost target of $75/sq m. The ease of manufacturability, installation and replacement make this technology a compelling one to develop. This technology can be easily modified for a variety of CSP options including heliostats, parabolic dishes and parabolic troughs.

Direct sunlight facility for testing and research in HCPV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sciortino, Luisa, E-mail: luisa.sciortino@unipa.it; Agnello, Simonpietro, E-mail: luisa.sciortino@unipa.it; Bonsignore, Gaetano

2014-09-26

A facility for testing different components for HCPV application has been developed in the framework of 'Fotovoltaico ad Alta Efficienza' (FAE) project funded by the Sicilian Regional Authority (PO FESR Sicilia 2007/2013 4.1.1.1). The testing facility is equipped with an heliostat providing a wide solar beam inside the lab, an optical bench for mounting and aligning the HCPV components, electronic equipments to characterize the I-V curves of multijunction cells operated up to 2000 suns, a system to circulate a fluid in the heat sink at controlled temperature and flow-rate, a data logging system with sensors to measure temperatures in severalmore » locations and fluid pressures at the inlet and outlet of the heat sink, and a climatic chamber with large test volume to test assembled HCPV modules.« less

Composites in energy generation and storage systems - An overview

NASA Astrophysics Data System (ADS)

Fulmer, R. W.

Applications of glass-fiber reinforced composites (GER) in renewable and high-efficiency energy systems which are being developed to replace interim, long-term unacceptable energy sources such as foreign oil are reviewed. GFR are noted to have design flexibility, high strength, and low cost, as well as featuring a choice of fiber orientation and type of reinforcement. Blades, hub covers, nacelles, and towers for large and small WECS are being fabricated and tested and are displaying satisfactory strength, resistance to corrosion and catastrophic failure, impact tolerance, and light weight. Promising results have also been shown in the use of GFR as flywheel material for kinetic energy storage in conjunction with solar and wind electric systems, in electric cars, and as load levellers. Other applications are for heliostats, geothermal power plant pipes, dam-atoll tidal wave energy systems, and intake pipes for OTECs.

Video rate morphological processor based on a redundant number representation

NASA Astrophysics Data System (ADS)

Kuczborski, Wojciech; Attikiouzel, Yianni; Crebbin, Gregory A.

1992-03-01

This paper presents a video rate morphological processor for automated visual inspection of printed circuit boards, integrated circuit masks, and other complex objects. Inspection algorithms are based on gray-scale mathematical morphology. Hardware complexity of the known methods of real-time implementation of gray-scale morphology--the umbra transform and the threshold decomposition--has prompted us to propose a novel technique which applied an arithmetic system without carrying propagation. After considering several arithmetic systems, a redundant number representation has been selected for implementation. Two options are analyzed here. The first is a pure signed digit number representation (SDNR) with the base of 4. The second option is a combination of the base-2 SDNR (to represent gray levels of images) and the conventional twos complement code (to represent gray levels of structuring elements). Operation principle of the morphological processor is based on the concept of the digit level systolic array. Individual processing units and small memory elements create a pipeline. The memory elements store current image windows (kernels). All operation primitives of processing units apply a unified direction of digit processing: most significant digit first (MSDF). The implementation technology is based on the field programmable gate arrays by Xilinx. This paper justified the rationality of a new approach to logic design, which is the decomposition of Boolean functions instead of Boolean minimization.

An integrated radar model solution for mission level performance and cost trades

NASA Astrophysics Data System (ADS)

Hodge, John; Duncan, Kerron; Zimmerman, Madeline; Drupp, Rob; Manno, Mike; Barrett, Donald; Smith, Amelia

2017-05-01

A fully integrated Mission-Level Radar model is in development as part of a multi-year effort under the Northrop Grumman Mission Systems (NGMS) sector's Model Based Engineering (MBE) initiative to digitally interconnect and unify previously separate performance and cost models. In 2016, an NGMS internal research and development (IR and D) funded multidisciplinary team integrated radio frequency (RF), power, control, size, weight, thermal, and cost models together using a commercial-off-the-shelf software, ModelCenter, for an Active Electronically Scanned Array (AESA) radar system. Each represented model was digitally connected with standard interfaces and unified to allow end-to-end mission system optimization and trade studies. The radar model was then linked to the Air Force's own mission modeling framework (AFSIM). The team first had to identify the necessary models, and with the aid of subject matter experts (SMEs) understand and document the inputs, outputs, and behaviors of the component models. This agile development process and collaboration enabled rapid integration of disparate models and the validation of their combined system performance. This MBE framework will allow NGMS to design systems more efficiently and affordably, optimize architectures, and provide increased value to the customer. The model integrates detailed component models that validate cost and performance at the physics level with high-level models that provide visualization of a platform mission. This connectivity of component to mission models allows hardware and software design solutions to be better optimized to meet mission needs, creating cost-optimal solutions for the customer, while reducing design cycle time through risk mitigation and early validation of design decisions.

Entanglement distribution in multi-particle systems in terms of unified entropy.

PubMed

Luo, Yu; Zhang, Fu-Gang; Li, Yongming

2017-04-25

We investigate the entanglement distribution in multi-particle systems in terms of unified (q, s)-entropy. We find that for any tripartite mixed state, the unified (q, s)-entropy entanglement of assistance follows a polygamy relation. This polygamy relation also holds in multi-particle systems. Furthermore, a generalized monogamy relation is provided for unified (q, s)-entropy entanglement in the multi-qubit system.

Software use cases to elicit the software requirements analysis within the ASTRI project

NASA Astrophysics Data System (ADS)

Conforti, Vito; Antolini, Elisa; Bonnoli, Giacomo; Bruno, Pietro; Bulgarelli, Andrea; Capalbi, Milvia; Fioretti, Valentina; Fugazza, Dino; Gardiol, Daniele; Grillo, Alessandro; Leto, Giuseppe; Lombardi, Saverio; Lucarelli, Fabrizio; Maccarone, Maria Concetta; Malaguti, Giuseppe; Pareschi, Giovanni; Russo, Federico; Sangiorgi, Pierluca; Schwarz, Joseph; Scuderi, Salvatore; Tanci, Claudio; Tosti, Gino; Trifoglio, Massimo; Vercellone, Stefano; Zanmar Sanchez, Ricardo

2016-07-01

The Italian National Institute for Astrophysics (INAF) is leading the Astrofisica con Specchi a Tecnologia Replicante Italiana (ASTRI) project whose main purpose is the realization of small size telescopes (SST) for the Cherenkov Telescope Array (CTA). The first goal of the ASTRI project has been the development and operation of an innovative end-to-end telescope prototype using a dual-mirror optical configuration (SST-2M) equipped with a camera based on silicon photo-multipliers and very fast read-out electronics. The ASTRI SST-2M prototype has been installed in Italy at the INAF "M.G. Fracastoro" Astronomical Station located at Serra La Nave, on Mount Etna, Sicily. This prototype will be used to test several mechanical, optical, control hardware and software solutions which will be used in the ASTRI mini-array, comprising nine telescopes proposed to be placed at the CTA southern site. The ASTRI mini-array is a collaborative and international effort led by INAF and carried out by Italy, Brazil and South-Africa. We present here the use cases, through UML (Unified Modeling Language) diagrams and text details, that describe the functional requirements of the software that will manage the ASTRI SST-2M prototype, and the lessons learned thanks to these activities. We intend to adopt the same approach for the Mini Array Software System that will manage the ASTRI miniarray operations. Use cases are of importance for the whole software life cycle; in particular they provide valuable support to the validation and verification activities. Following the iterative development approach, which breaks down the software development into smaller chunks, we have analysed the requirements, developed, and then tested the code in repeated cycles. The use case technique allowed us to formalize the problem through user stories that describe how the user procedurally interacts with the software system. Through the use cases we improved the communication among team members, fostered common agreement about system requirements, defined the normal and alternative course of events, understood better the business process, and defined the system test to ensure that the delivered software works properly. We present a summary of the ASTRI SST-2M prototype use cases, and how the lessons learned can be exploited for the ASTRI mini-array proposed for the CTA Observatory.

A Unified Approach to Modeling Multidisciplinary Interactions

NASA Technical Reports Server (NTRS)

Samareh, Jamshid A.; Bhatia, Kumar G.

2000-01-01

There are a number of existing methods to transfer information among various disciplines. For a multidisciplinary application with n disciplines, the traditional methods may be required to model (n(exp 2) - n) interactions. This paper presents a unified three-dimensional approach that reduces the number of interactions from (n(exp 2) - n) to 2n by using a computer-aided design model. The proposed modeling approach unifies the interactions among various disciplines. The approach is independent of specific discipline implementation, and a number of existing methods can be reformulated in the context of the proposed unified approach. This paper provides an overview of the proposed unified approach and reformulations for two existing methods. The unified approach is specially tailored for application environments where the geometry is created and managed through a computer-aided design system. Results are presented for a blended-wing body and a high-speed civil transport.

EURELIOS, the world's first thermomechanical helioelectric power plant

NASA Astrophysics Data System (ADS)

Gretz, J.

Characteristics of the power source, design, costs and operating mechanisms and performance of the EURELIOS central receiver solar electric power plant are described. Noting that the solar input at the earth's surface is about 1 kW/sq m, 6200 sq m of float glass mirrors mounted on 182 heliostats were fabricated to focus the incoming radiation onto a receiver aperture atop a 55 m high tower. The curved mirrors permit the focus of 80% of the energy input to be deposited on a 2.2 m diam aperture which is equipped with heat exchangers imbedded in pyrex and darkened and finned to maximize absorption. Feedwater is superheated in the receiver and is transferred to a buffer tank of hot water at 19 bar and molten salt at 410 C, and then on to turbines for actual power production. The grid serves as back-up power system. Total costs are calculated at $1600/kWe.

Growth structure and superconductivity of Bi1.7Bi0.3Sr2Ca2Cu3O10+δ ceramics synthesized from glass-crystal precursors processed in solar type ovens

NASA Astrophysics Data System (ADS)

Acrivos, J. V.; Gulamova, D. D.; Chigvinadze, J. G.; Loy, D.

2010-03-01

The growth structure as well as the superconductivity of Bi/Pb2223 alloys is reported. Periodic lattice distortions (PLD) along the ab plane diagonal, direction of superconducting transport at the transition temperature, Tc=107K are found to dominate the growth. Trransport induced by the PLD may be responsible for the sharp Tc transitions, and the bursts of frequency and Abrikosov oscillations observed above the transition temperature up to 150K. Chemical synthesis in a heliostat oven was followed by fast quenching of the melt and annealing at 840-850K, XRD near the Cu K-edge, and Tc measured by axial-torsional vibrations in transverse magnetic fields. Tc and phaase purity obtained by green solid state chemistry, in a solar spectrum, will be discussed.

Performance modeling and techno-economic analysis of a modular concentrated solar power tower with latent heat storage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rea, Jonathan E.; Oshman, Christopher J.; Olsen, Michele L.

In this paper, we present performance simulations and techno-economic analysis of a modular dispatchable solar power tower. Using a heliostat field and power block three orders of magnitude smaller than conventional solar power towers, our unique configuration locates thermal storage and a power block directly on a tower receiver. To make the system dispatchable, a valved thermosyphon controls heat flow from a latent heat thermal storage tank to a Stirling engine. The modular design results in minimal balance of system costs and enables high deployment rates with a rapid realization of economies of scale. In this new analysis, we combinemore » performance simulations with techno-economic analysis to evaluate levelized cost of electricity, and find that the system has potential for cost-competitiveness with natural gas peaking plants and alternative dispatchable renewables.« less

25  W/m² collection efficiency solar-pumped Nd:YAG laser by a heliostat-parabolic mirror system.

PubMed

Liang, D; Almeida, J; Vistas, C R

2016-09-20

A large aspheric fused silica lens was used to couple efficiently the concentrated solar radiation from the focal zone of a 1.5-m-diameter primary concentrator into a 4-mm-diameter, 35-mm-long Nd:YAG single-crystal rod within a conical pump cavity. Continuous-wave laser power of 29.3 W was measured, attaining 25.0  W/m² solar laser collection efficiency, corresponding to a 19% increase over the previous record. Its laser beam figure of merit-the ratio between laser power and the product of Mx2, My2 beam quality factors-of 0.01 W is 1.6 times higher than that of a direct tracking solar laser with 30  W/m² collection efficiency. A strong dependency of solar laser power on laser resonator cavity length was found.

Measurement of solar extinction in tower plants with digital cameras

NASA Astrophysics Data System (ADS)

Ballestrín, J.; Monterreal, R.; Carra, M. E.; Fernandez-Reche, J.; Barbero, J.; Marzo, A.

2016-05-01

Atmospheric extinction of solar radiation between the heliostat field and the receiver is accepted as a non-negligible source of energy loss in the increasingly large central receiver plants. However, the reality is that there is currently no reliable measurement method for this quantity and at present these plants are designed, built and operated without knowing this local parameter. Nowadays digital cameras are used in many scientific applications for their ability to convert available light into digital images. Its broad spectral range, high resolution and high signal to noise ratio, make them an interesting device in solar technology. In this work a method for atmospheric extinction measurement based on digital images is presented. The possibility of defining a measurement setup in circumstances similar to those of a tower plant increases the credibility of the method. This procedure is currently being implemented at Plataforma Solar de Almería.

Dynamic detailed model of a molten salt tower receiver, with ThermoSysPro library: Impacts of several failures or operational transients on the receiver dynamic behavior

NASA Astrophysics Data System (ADS)

Hefni, Baligh El; Bourdil, Charles

2017-06-01

Molten salt technology represents nowadays the most cost-effective technology for electricity generation for solar power plant. The molten salt tower receiver is based on a field of individually sun-tracking mirrors (heliostats) that reflect the incident sunshine to a receiver at the top of a centrally located tower. The objective of this study is to assess the impact of several transients issued from different scenarios (failure or normal operation mode) on the receiver dynamic behavior. A dynamic detailed model of Solar Two molten salt central receiver has been developed. The component model is meant to be used for receiver modeling with the ThermoSysPro library, developed by EDF. The paper also gives the results of the dynamic simulation for the selected scenarios on Solar Two receiver.

CSP cogeneration of electricity and desalinated water at the Pentakomo field facility

NASA Astrophysics Data System (ADS)

Papanicolas, C. N.; Bonanos, A. M.; Georgiou, M. C.; Guillen, E.; Jarraud, N.; Marakkos, C.; Montenon, A.; Stiliaris, E.; Tsioli, E.; Tzamtzis, G.; Votyakov, E. V.

2016-05-01

The Cyprus Institute's Pentakomo Field Facility (PFF) is a major infrastructure for research, development and testing of technologies relating to concentrated solar power (CSP) and solar seawater desalination. It is located at the south coast of Cyprus near the sea and its environmental conditions are fully monitored. It provides a test facility specializing in the development of CSP systems suitable for island and coastal environments with particular emphasis on small units (<25 MWth) endowed with substantial storage, suitable for use in isolation or distributed in small power grids. The first major experiment to take place at the PFF concerns the development of a pilot/experimental facility for the co-generation of electricity and desalinated seawater from CSP. Specifically, the experimental plant consists of a heliostat-central receiver system for solar harvesting, thermal energy storage in molten salts followed by a Rankine cycle for electricity production and a multiple-effect distillation (MED) unit for desalination.

Prototype of sun projector device

NASA Astrophysics Data System (ADS)

Ihsan; Dermawan, B.

2016-11-01

One way to introduce astronomy to public, including students, can be handled by solar observation. The widely held device for this purpose is coelostat and heliostat. Besides using filter attached to a device such as telescope, it is safest to use indirect way for observing the Sun. The main principle of the indirect way is deflecting the sun light and projecting image of the sun on a screen. We design and build a simple and low-cost astronomical device, serving as a supplement to increase public service, especially for solar observation. Without using any digital and intricate supporting equipment, people can watch and relish image of the Sun in comfortable condition, i.e. in a sheltered or shady place. Here we describe a design and features of our prototype of the device, which still, of course, has some limitations. In the future, this prototype can be improved for more efficient and useful applications.

75 FR 37727 - Disapproval of California State Implementation Plan Revisions, Monterey Bay Unified Air Pollution...

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Development of a Wireless Unified-Maintenance System for the Structural Health Monitoring of Civil Structures

PubMed Central

Son, Byungjik; Jeon, Seunggon

2018-01-01

A disaster preventive structural health monitoring (SHM) system needs to be equipped with the following abilities: First, it should be able to simultaneously measure diverse types of data (e.g., displacement, velocity, acceleration, strain, load, temperature, humidity, etc.) for accurate diagnosis. Second, it also requires standalone power supply to guarantee its immediate response in crisis (e.g., sudden interruption of normal AC power in disaster situations). Furthermore, it should be capable of prompt processing and realtime wireless communication of a huge amount of data. Therefore, this study is aimed at developing a wireless unified-maintenance system (WUMS) that would satisfy all the requirements for a disaster preventive SHM system of civil structures. The WUMS is designed to measure diverse types of structural responses in realtime based on wireless communication, allowing users to selectively use WiFi RF band and finally working in standalone mode by means of the field-programmable gate array (FPGA) technology. To verify its performance, the following tests were performed: (i) A test to see how far communication is possible in open field, (ii) a test on a shaker to see how accurate responses are, (iii) a modal test on a bridge to see how exactly characteristic real-time dynamic responses are of structures. The test results proved that the WUMS was able to secure stable communication far up to nearly 800 m away by acquiring wireless responses in realtime accurately, when compared to the displacement and acceleration responses which were acquired through wired communication. The analysis of dynamic characteristics also showed that the wireless acceleration responses in real-time represented satisfactorily the dynamic properties of structures. Therefore, the WUMS is proved valid as a SHM, and its outstanding performance is also proven. PMID:29747403

Development of a Wireless Unified-Maintenance System for the Structural Health Monitoring of Civil Structures.

PubMed

Heo, Gwanghee; Son, Byungjik; Kim, Chunggil; Jeon, Seunggon; Jeon, Joonryong

2018-05-09

A disaster preventive structural health monitoring (SHM) system needs to be equipped with the following abilities: First, it should be able to simultaneously measure diverse types of data (e.g., displacement, velocity, acceleration, strain, load, temperature, humidity, etc.) for accurate diagnosis. Second, it also requires standalone power supply to guarantee its immediate response in crisis (e.g., sudden interruption of normal AC power in disaster situations). Furthermore, it should be capable of prompt processing and realtime wireless communication of a huge amount of data. Therefore, this study is aimed at developing a wireless unified-maintenance system (WUMS) that would satisfy all the requirements for a disaster preventive SHM system of civil structures. The WUMS is designed to measure diverse types of structural responses in realtime based on wireless communication, allowing users to selectively use WiFi RF band and finally working in standalone mode by means of the field-programmable gate array (FPGA) technology. To verify its performance, the following tests were performed: (i) A test to see how far communication is possible in open field, (ii) a test on a shaker to see how accurate responses are, (iii) a modal test on a bridge to see how exactly characteristic real-time dynamic responses are of structures. The test results proved that the WUMS was able to secure stable communication far up to nearly 800 m away by acquiring wireless responses in realtime accurately, when compared to the displacement and acceleration responses which were acquired through wired communication. The analysis of dynamic characteristics also showed that the wireless acceleration responses in real-time represented satisfactorily the dynamic properties of structures. Therefore, the WUMS is proved valid as a SHM, and its outstanding performance is also proven.

Incubation, Insight, and Creative Problem Solving: A Unified Theory and a Connectionist Model

ERIC Educational Resources Information Center

Helie, Sebastien; Sun, Ron

2010-01-01

This article proposes a unified framework for understanding creative problem solving, namely, the explicit-implicit interaction theory. This new theory of creative problem solving constitutes an attempt at providing a more unified explanation of relevant phenomena (in part by reinterpreting/integrating various fragmentary existing theories of…

Toward a Unified Componential Theory of Human Reasoning. Technical Report No. 4.

ERIC Educational Resources Information Center

Sternberg, Robert J.

The unified theory described in this paper characterizes human reasoning as an information processing system with a hierarchical sequence of components and subtheories that account for performance on successively narrower tasks. Both deductive and inductive theories are subsumed in the unified componential theory, including transitive chain theory…

Alternative Fuels Data Center: Mesa Unified School District Reaps Economic

Science.gov Websites

and Environmental Benefits with Propane Buses Mesa Unified School District Reaps Economic and School District Reaps Economic and Environmental Benefits with Propane Buses on Facebook Tweet about Alternative Fuels Data Center: Mesa Unified School District Reaps Economic and Environmental Benefits with

Cincinnati's Bold New Venture: A Unified K-12 Reading/Communication Arts Program.

ERIC Educational Resources Information Center

Green, Reginald Leon

1989-01-01

Describes a unified reading/communication arts program in the Cincinnati Public School System which uses new basal texts, support materials, and a customized instructional system for each grade level, integrating listening, speaking, reading, writing, and thinking skills into a unified language approach. Discusses intervention strategies,…

76 FR 39991 - Introduction to the Unified Agenda of Federal Regulatory and Deregulatory Actions

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Unified Approximations: A New Approach for Monoprotic Weak Acid-Base Equilibria

ERIC Educational Resources Information Center

Pardue, Harry; Odeh, Ihab N.; Tesfai, Teweldemedhin M.

2004-01-01

The unified approximations reduce the conceptual complexity by combining solutions for a relatively large number of different situations into just two similar sets of processes. Processes used to solve problems by either the unified or classical approximations require similar degrees of understanding of the underlying chemical processes.

29 CFR 779.218 - Methods to accomplish “unified operation.”

Code of Federal Regulations, 2010 CFR

2010-07-01

..., join together to perform some or all of their activities as a unified business or business system. They may accomplish such unification through agreements, franchises, grants, leases, or other arrangements... others so that they constitute a single business or unified business system. Whether in any particular...

Introduction to The Regulatory Plan and the Unified Agenda of Federal...

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76 FR 16696 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

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2011-03-25

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Unified Early Childhood Personnel Preparation Programs: Perceptions from the Field.

ERIC Educational Resources Information Center

LaMontagne, M. J.; Johnson, Lawrence J.; Kilgo, Jennifer L.; Stayton, Vicki; Carr, Victoria; Bauer, Anne M.; Carpenter, Jenny

2002-01-01

This study examined perceptions of unified early childhood personnel preparation programs by 28 faculty members in such programs and by graduates (n=42) of unified, dual, or separate exceptional child education or exceptional child special education programs. Faculty stressed the importance of commitment and collaborative problem solving. The…

77 FR 24883 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

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2012-04-26

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Phase noise suppression for coherent optical block transmission systems: a unified framework.

PubMed

Yang, Chuanchuan; Yang, Feng; Wang, Ziyu

2011-08-29

A unified framework for phase noise suppression is proposed in this paper, which could be applied in any coherent optical block transmission systems, including coherent optical orthogonal frequency-division multiplexing (CO-OFDM), coherent optical single-carrier frequency-domain equalization block transmission (CO-SCFDE), etc. Based on adaptive modeling of phase noise, unified observation equations for different coherent optical block transmission systems are constructed, which lead to unified phase noise estimation and suppression. Numerical results demonstrate that the proposal is powerful in mitigating laser phase noise.

The ecology of entrainment: Foundations of coordinated rhythmic movement.

PubMed

Phillips-Silver, Jessica; Aktipis, C Athena; Bryant, Gregory A

2010-09-01

Entrainment has been studied in a variety of contexts including music perception, dance, verbal communication and motor coordination more generally. Here we seek to provide a unifying framework that incorporates the key aspects of entrainment as it has been studied in these varying domains. We propose that there are a number of types of entrainment that build upon pre-existing adaptations that allow organisms to perceive stimuli as rhythmic, to produce periodic stimuli, and to integrate the two using sensory feedback. We suggest that social entrainment is a special case of spatiotemporal coordination where the rhythmic signal originates from another individual. We use this framework to understand the function and evolutionary basis for coordinated rhythmic movement and to explore questions about the nature of entrainment in music and dance. The framework of entrainment presented here has a number of implications for the vocal learning hypothesis and other proposals for the evolution of coordinated rhythmic behavior across an array of species.

BioMart Central Portal: an open database network for the biological community

PubMed Central

Guberman, Jonathan M.; Ai, J.; Arnaiz, O.; Baran, Joachim; Blake, Andrew; Baldock, Richard; Chelala, Claude; Croft, David; Cros, Anthony; Cutts, Rosalind J.; Di Génova, A.; Forbes, Simon; Fujisawa, T.; Gadaleta, E.; Goodstein, D. M.; Gundem, Gunes; Haggarty, Bernard; Haider, Syed; Hall, Matthew; Harris, Todd; Haw, Robin; Hu, S.; Hubbard, Simon; Hsu, Jack; Iyer, Vivek; Jones, Philip; Katayama, Toshiaki; Kinsella, R.; Kong, Lei; Lawson, Daniel; Liang, Yong; Lopez-Bigas, Nuria; Luo, J.; Lush, Michael; Mason, Jeremy; Moreews, Francois; Ndegwa, Nelson; Oakley, Darren; Perez-Llamas, Christian; Primig, Michael; Rivkin, Elena; Rosanoff, S.; Shepherd, Rebecca; Simon, Reinhard; Skarnes, B.; Smedley, Damian; Sperling, Linda; Spooner, William; Stevenson, Peter; Stone, Kevin; Teague, J.; Wang, Jun; Wang, Jianxin; Whitty, Brett; Wong, D. T.; Wong-Erasmus, Marie; Yao, L.; Youens-Clark, Ken; Yung, Christina; Zhang, Junjun; Kasprzyk, Arek

2011-01-01

BioMart Central Portal is a first of its kind, community-driven effort to provide unified access to dozens of biological databases spanning genomics, proteomics, model organisms, cancer data, ontology information and more. Anybody can contribute an independently maintained resource to the Central Portal, allowing it to be exposed to and shared with the research community, and linking it with the other resources in the portal. Users can take advantage of the common interface to quickly utilize different sources without learning a new system for each. The system also simplifies cross-database searches that might otherwise require several complicated steps. Several integrated tools streamline common tasks, such as converting between ID formats and retrieving sequences. The combination of a wide variety of databases, an easy-to-use interface, robust programmatic access and the array of tools make Central Portal a one-stop shop for biological data querying. Here, we describe the structure of Central Portal and show example queries to demonstrate its capabilities. Database URL: http://central.biomart.org. PMID:21930507

Some empirical observations about early stuttering: a possible link to language development.

PubMed

Bloodstein, O

2006-01-01

This article suggests a possible link between incipient stuttering and early difficulty in language formulation. The hypothesis offers a unifying explanation of an array of empirical observations. Among these observations are the following: early stuttering occurs only on the first word of a syntactic structure; stuttering does not appear to be influenced by word-related factors; early stuttering seldom occurs on one-word utterances; the earliest age at which stuttering is reported is 18 months, with the beginning of grammatical development; the age at which most onset of stuttering is reported, 2-5 years, coincides with the period during which children acquire syntax; considerable spontaneous recovery takes place at the time most children have mastered syntax; incipient stuttering is influenced by the length and grammatical complexity of utterances; young children who stutter may be somewhat deficient in language skills; boys who stutter outnumber girls. The reader will learn about a number of empirical observations about incipient stuttering and how they may be explained by a syntax-based hypothesis about its etiology.

Short-Term Forecasts Using NU-WRF for the Winter Olympics 2018

NASA Technical Reports Server (NTRS)

Srikishen, Jayanthi; Case, Jonathan L.; Petersen, Walter A.; Iguchi, Takamichi; Tao, Wei-Kuo; Zavodsky, Bradley T.; Molthan, Andrew

2017-01-01

The NASA Unified-Weather Research and Forecasting model (NU-WRF) will be included for testing and evaluation in the forecast demonstration project (FDP) of the International Collaborative Experiment -PyeongChang 2018 Olympic and Paralympic (ICE-POP) Winter Games. An international array of radar and supporting ground based observations together with various forecast and now-cast models will be operational during ICE-POP. In conjunction with personnel from NASA's Goddard Space Flight Center, the NASA Short-term Prediction Research and Transition (SPoRT) Center is developing benchmark simulations for a real-time NU-WRF configuration to run during the FDP. ICE-POP observational datasets will be used to validate model simulations and investigate improved model physics and performance for prediction of snow events during the research phase (RDP) of the project The NU-WRF model simulations will also support NASA Global Precipitation Measurement (GPM) Mission ground-validation physical and direct validation activities in relation to verifying, testing and improving satellite-based snowfall retrieval algorithms over complex terrain.

Diagnostic layer integration in FPGA-based pipeline measurement systems for HEP experiments

NASA Astrophysics Data System (ADS)

Pozniak, Krzysztof T.

2007-08-01

Integrated triggering and data acquisition systems for high energy physics experiments may be considered as fast, multichannel, synchronous, distributed, pipeline measurement systems. A considerable extension of functional, technological and monitoring demands, which has recently been imposed on them, forced a common usage of large field-programmable gate array (FPGA), digital signal processing-enhanced matrices and fast optical transmission for their realization. This paper discusses modelling, design, realization and testing of pipeline measurement systems. A distribution of synchronous data stream flows is considered in the network. A general functional structure of a single network node is presented. A suggested, novel block structure of the node model facilitates full implementation in the FPGA chip, circuit standardization and parametrization, as well as integration of functional and diagnostic layers. A general method for pipeline system design was derived. This method is based on a unified model of the synchronous data network node. A few examples of practically realized, FPGA-based, pipeline measurement systems were presented. The described systems were applied in ZEUS and CMS.

BioMart Central Portal: an open database network for the biological community.

PubMed

Guberman, Jonathan M; Ai, J; Arnaiz, O; Baran, Joachim; Blake, Andrew; Baldock, Richard; Chelala, Claude; Croft, David; Cros, Anthony; Cutts, Rosalind J; Di Génova, A; Forbes, Simon; Fujisawa, T; Gadaleta, E; Goodstein, D M; Gundem, Gunes; Haggarty, Bernard; Haider, Syed; Hall, Matthew; Harris, Todd; Haw, Robin; Hu, S; Hubbard, Simon; Hsu, Jack; Iyer, Vivek; Jones, Philip; Katayama, Toshiaki; Kinsella, R; Kong, Lei; Lawson, Daniel; Liang, Yong; Lopez-Bigas, Nuria; Luo, J; Lush, Michael; Mason, Jeremy; Moreews, Francois; Ndegwa, Nelson; Oakley, Darren; Perez-Llamas, Christian; Primig, Michael; Rivkin, Elena; Rosanoff, S; Shepherd, Rebecca; Simon, Reinhard; Skarnes, B; Smedley, Damian; Sperling, Linda; Spooner, William; Stevenson, Peter; Stone, Kevin; Teague, J; Wang, Jun; Wang, Jianxin; Whitty, Brett; Wong, D T; Wong-Erasmus, Marie; Yao, L; Youens-Clark, Ken; Yung, Christina; Zhang, Junjun; Kasprzyk, Arek

2011-01-01

BioMart Central Portal is a first of its kind, community-driven effort to provide unified access to dozens of biological databases spanning genomics, proteomics, model organisms, cancer data, ontology information and more. Anybody can contribute an independently maintained resource to the Central Portal, allowing it to be exposed to and shared with the research community, and linking it with the other resources in the portal. Users can take advantage of the common interface to quickly utilize different sources without learning a new system for each. The system also simplifies cross-database searches that might otherwise require several complicated steps. Several integrated tools streamline common tasks, such as converting between ID formats and retrieving sequences. The combination of a wide variety of databases, an easy-to-use interface, robust programmatic access and the array of tools make Central Portal a one-stop shop for biological data querying. Here, we describe the structure of Central Portal and show example queries to demonstrate its capabilities.

Consciousness and the natural method.

PubMed

Flanagan, O

1995-09-01

'Consciousness' is a superordinate term for a heterogeneous array of mental state types. The types share the property of 'being experienced' or 'being experiences'--'of there being something that it is like for the subject to be in one of these states.' I propose that we can only build a theory of consciousness by deploying 'the natural method' of coordinating all relevant informational resources at once, especially phenomenology, cognitive science, neuroscience and evolutionary biology. I'll provide two examples of the natural method in action in mental domains where an adaptationist evolutionary account seems plausible: (i) visual awareness and (ii) conscious event memory. Then I will discuss a case, (iii), dreaming, where I think no adaptationist evolutionary account exists. Beyond whatever interest the particular cases have, the examination will show why I think that a theory of mind, and the role conscious mentation plays in it, will need to be built domain-by-domain with no a priori expectation that there will be a unified account of the causal role or evolutionary history of different domains and competences.

The ecology of entrainment: Foundations of coordinated rhythmic movement

PubMed Central

Phillips-Silver, Jessica; Aktipis, C. Athena; Bryant, Gregory A.

2011-01-01

Entrainment has been studied in a variety of contexts including music perception, dance, verbal communication and motor coordination more generally. Here we seek to provide a unifying framework that incorporates the key aspects of entrainment as it has been studied in these varying domains. We propose that there are a number of types of entrainment that build upon pre-existing adaptations that allow organisms to perceive stimuli as rhythmic, to produce periodic stimuli, and to integrate the two using sensory feedback. We suggest that social entrainment is a special case of spatiotemporal coordination where the rhythmic signal originates from another individual. We use this framework to understand the function and evolutionary basis for coordinated rhythmic movement and to explore questions about the nature of entrainment in music and dance. The framework of entrainment presented here has a number of implications for the vocal learning hypothesis and other proposals for the evolution of coordinated rhythmic behavior across an array of species. PMID:21776183

ACHP | News | ACHP Issue Spotlight: Transmission Lines in the West

Science.gov Websites

Search skip specific nav links Home arrow News arrow New Applicant Guidance for Unified Federal Review for Disaster Recovery New Applicant Guidance for Unified Federal Review for Disaster Recovery The ACHP announce the release of the Unified Federal Environmental and Historic Preservation Review Guide for

Unified Science Approach K-12, Proficiency Levels 7-12.

ERIC Educational Resources Information Center

Oickle, Eileen M., Ed.

Presented is the second part of the K-12 unified science materials used in the public schools of Anne Arundel County, Maryland. Detailed descriptions are made of the roles of students and teachers, purposes of the bibliography, major concepts in unified science, processes of inquiry, a scheme and model for scientific literacy, and program…

14 CFR 1221.108 - Establishment of the NASA Unified Visual Communications System.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false Establishment of the NASA Unified Visual... ADMINISTRATION THE NASA SEAL AND OTHER DEVICES, AND THE CONGRESSIONAL SPACE MEDAL OF HONOR NASA Seal, NASA Insignia, NASA Logotype, NASA Program Identifiers, NASA Flags, and the Agency's Unified Visual...

14 CFR § 1221.108 - Establishment of the NASA Unified Visual Communications System.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 5 2014-01-01 2014-01-01 false Establishment of the NASA Unified Visual... ADMINISTRATION THE NASA SEAL AND OTHER DEVICES, AND THE CONGRESSIONAL SPACE MEDAL OF HONOR NASA Seal, NASA Insignia, NASA Logotype, NASA Program Identifiers, NASA Flags, and the Agency's Unified Visual...

14 CFR 1221.108 - Establishment of the NASA Unified Visual Communications System.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Establishment of the NASA Unified Visual... ADMINISTRATION THE NASA SEAL AND OTHER DEVICES, AND THE CONGRESSIONAL SPACE MEDAL OF HONOR NASA Seal, NASA Insignia, NASA Logotype, NASA Program Identifiers, NASA Flags, and the Agency's Unified Visual...

75 FR 79929 - Semiannual Regulatory Agenda

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-20

... Respect to Mortgage Loans, to be codified at 16 CFR 321, 322; (7) Retail Food Store Advertising and..., which appears in both the online Unified Agenda and in part II of the Federal Register that includes the... disseminating the Unified Agenda. The complete Unified Agenda will be available online at www.reginfo.gov, in a...

75 FR 4759 - Withdrawal of Proposed Rule Revising the California State Implementation Plan, San Joaquin Valley...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-29

... Proposed Rule Revising the California State Implementation Plan, San Joaquin Valley Unified Air Pollution... approval of revisions to the San Joaquin Valley Unified Air Pollution Control District portion of the... revisions to the San Joaquin Valley Unified Air Pollution Control District (``District'') portion of the...

Unified Science Approach K-12, Proficiency Levels 1-6.

ERIC Educational Resources Information Center

Oickle, Eileen M., Ed.

Presented are first-revision materials of the K-12 unified science program implemented in the public schools of Anne Arundel County, Maryland. Detailed descriptions are given of the roles of students and teachers, purposes of bibliography, major concepts in unified science, processes of inquiry, scheme and model for scientific literacy, and…

77 FR 73392 - Revisions to the California State Implementation Plan, Monterey Bay Unified Air Pollution Control...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-10

... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [EPA-R09-OAR-2012-0808; FRL-9750-3] Revisions to the California State Implementation Plan, Monterey Bay Unified Air Pollution Control District AGENCY... the Monterey Bay Unified Air Pollution Control District (MBUAPCD) portion of the California State...

76 FR 56134 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-12

... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of... preempt Tribal law. List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control...

76 FR 59254 - Interim Final Determination To Stay and Defer Sanctions, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-26

... Determination To Stay and Defer Sanctions, San Joaquin Valley Unified Air Pollution Control District AGENCY... on a proposed approval of revisions to the San Joaquin Valley Unified Air Pollution Control District...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control...

76 FR 53640 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-29

... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the... section 307(b)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control...

76 FR 56132 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-12

... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of... preempt Tribal law. List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control...

76 FR 17347 - Revision to the California State Implementation Plan, Great Basin Unified Air Pollution Control...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-29

... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 Revision to the California State Implementation Plan, Great Basin Unified Air Pollution Control District CFR Correction In Title 40 of the Code of.... * * * * * (c) * * * (345) * * * (i) * * * (D) Great Basin Unified Air Pollution Control District (1) Rule 201...

76 FR 45199 - Interim Final Determination To Defer Sanctions, San Joaquin Valley Unified Air Pollution Control...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-28

... Determination To Defer Sanctions, San Joaquin Valley Unified Air Pollution Control District, CA AGENCY... limited approval and limited disapproval of revisions to the San Joaquin Valley Unified Air Pollution... section 307(b)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control...

77 FR 7536 - Revisions to the California State Implementation Plan, Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-13

... the California State Implementation Plan, Joaquin Valley Unified Air Pollution Control District AGENCY... the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portions of the California... U.S.C. 804(2). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control...

75 FR 57862 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-23

... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the... section 307(b)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control...

77 FR 58312 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-20

... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control... section 307(b)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control...

77 FR 24857 - Interim Final Determination To Stay and Defer Sanctions, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-26

... Determination To Stay and Defer Sanctions, San Joaquin Valley Unified Air Pollution Control District AGENCY... on a proposed approval of revisions to the San Joaquin Valley Unified Air Pollution Control District... Subjects in 40 CFR Part 52 Environmental protection, Air pollution control, Intergovernmental regulations...

24 CFR 578.41 - Unified Funding Agency costs.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 24 Housing and Urban Development 3 2014-04-01 2013-04-01 true Unified Funding Agency costs. 578.41 Section 578.41 Housing and Urban Development Regulations Relating to Housing and Urban Development... § 578.41 Unified Funding Agency costs. (a) In general. UFAs may use up to 3 percent of their FPRN, or a...

Benchmarking and Evaluating Unified Memory for OpenMP GPU Offloading

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mishra, Alok; Li, Lingda; Kong, Martin

Here, the latest OpenMP standard offers automatic device offloading capabilities which facilitate GPU programming. Despite this, there remain many challenges. One of these is the unified memory feature introduced in recent GPUs. GPUs in current and future HPC systems have enhanced support for unified memory space. In such systems, CPU and GPU can access each other's memory transparently, that is, the data movement is managed automatically by the underlying system software and hardware. Memory over subscription is also possible in these systems. However, there is a significant lack of knowledge about how this mechanism will perform, and how programmers shouldmore » use it. We have modified several benchmarks codes, in the Rodinia benchmark suite, to study the behavior of OpenMP accelerator extensions and have used them to explore the impact of unified memory in an OpenMP context. We moreover modified the open source LLVM compiler to allow OpenMP programs to exploit unified memory. The results of our evaluation reveal that, while the performance of unified memory is comparable with that of normal GPU offloading for benchmarks with little data reuse, it suffers from significant overhead when GPU memory is over subcribed for benchmarks with large amount of data reuse. Based on these results, we provide several guidelines for programmers to achieve better performance with unified memory.« less

Unified Science Approach K-12, Proficiency Levels 13-21 and Semester Courses.

ERIC Educational Resources Information Center

Oickle, Eileen M., Ed.

Presented is the third part of the K-12 unified science materials used in the public schools of Anne Arundel County, Maryland. Detailed descriptions are presented for the roles of students and teachers, purposes of bibliography, major concepts in unified science, processes of inquiry, scheme and model for scientific literacy, and program…

78 FR 18235 - Unified Rule for Loss on Subsidiary Stock

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-26

... DEPARTMENT OF THE TREASURY Internal Revenue Service 26 CFR Part 1 Unified Rule for Loss on Subsidiary Stock CFR Correction 0 In Title 26 of the Code of Federal Regulations, Part 1 (Sec. Sec. 1.1401 to...) Example 6 (ii)(D)(3), reinstate the following sentence: Sec. 1.1502-36 Unified loss rule. * * * * * (d...

26 CFR 1.1502-36 - Unified loss rule.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 26 Internal Revenue 12 2012-04-01 2012-04-01 false Unified loss rule. 1.1502-36 Section 1.1502-36 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Basis, Stock Ownership, and Earnings and Profits Rules § 1.1502-36 Unified loss rule. (a) In general—(1) Scope. This...

26 CFR 1.1502-36 - Unified loss rule.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 26 Internal Revenue 12 2014-04-01 2014-04-01 false Unified loss rule. 1.1502-36 Section 1.1502-36 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Basis, Stock Ownership, and Earnings and Profits Rules § 1.1502-36 Unified loss rule. (a) In general—(1) Scope. This...

26 CFR 1.1502-36 - Unified loss rule.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 12 2011-04-01 2011-04-01 false Unified loss rule. 1.1502-36 Section 1.1502-36 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Basis, Stock Ownership, and Earnings and Profits Rules § 1.1502-36 Unified loss rule. (a) In general—(1) Scope. This...

26 CFR 1.1502-36 - Unified loss rule.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 26 Internal Revenue 12 2013-04-01 2013-04-01 false Unified loss rule. 1.1502-36 Section 1.1502-36 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Basis, Stock Ownership, and Earnings and Profits Rules § 1.1502-36 Unified loss rule. (a) In general—(1) Scope. This...

An Estimation Procedure for the Structural Parameters of the Unified Cognitive/IRT Model.

ERIC Educational Resources Information Center

Jiang, Hai; And Others

L. V. DiBello, W. F. Stout, and L. A. Roussos (1993) have developed a new item response model, the Unified Model, which brings together the discrete, deterministic aspects of cognition favored by cognitive scientists, and the continuous, stochastic aspects of test response behavior that underlie item response theory (IRT). The Unified Model blends…

Contiguous triple spinal dysraphism associated with Chiari malformation Type II and hydrocephalus: an embryological conundrum between the unified theory of Pang and the unified theory of McLone.

PubMed

Dhandapani, Sivashanmugam; Srinivasan, Anirudh

2016-01-01

Triple spinal dysraphism is extremely rare. There are published reports of multiple discrete neural tube defects with intervening normal segments that are explained by the multisite closure theory of primary neurulation, having an association with Chiari malformation Type II consistent with the unified theory of McLone. The authors report on a 1-year-old child with contiguous myelomeningocele and lipomyelomeningocele centered on Type I split cord malformation with Chiari malformation Type II and hydrocephalus. This composite anomaly is probably due to select abnormalities of the neurenteric canal during gastrulation, with a contiguous cascading impact on both dysjunction of the neural tube and closure of the neuropore, resulting in a small posterior fossa, probably bringing the unified theory of McLone closer to the unified theory of Pang.

Design and implementation of a unified certification management system based on seismic business

NASA Astrophysics Data System (ADS)

Tang, Hongliang

2018-04-01

Many business software for seismic systems are based on web pages, users can simply open a browser and enter their IP address. However, how to achieve unified management and security management of many IP addresses, this paper introduces the design concept based on seismic business and builds a unified authentication management system using ASP technology.

29 CFR 779.220 - Unified operation may exist as to separately owned or controlled activities which are related.

Code of Federal Regulations, 2010 CFR

2010-07-01

... otherwise, they are so performed as to constitute a unified business system organized for a common business... their activities in such manner as to be for all intents and purposes a single business system except..., in part or in whole, by the individual companies comprising the unified business system. The various...

32 CFR Appendix C to Part 246 - Personnel Policies and Procedures

Code of Federal Regulations, 2011 CFR

2011-07-01

... Unified Commands, the American Forces Information Service (AFIS), and the U.S. Army to the S&S. 2. As DoD... Director of the AFIS, to the Unified Command Commander-in-Chief (CINC), who shall make the final selection... Unified Command CINC and the AFIS, to substitute a DoD-funded “training-with-industry” program with...

The Development of Cadastral Domain Model Oriented at Unified Real Estate Registration of China Based on Ontology

NASA Astrophysics Data System (ADS)

Li, M.; Zhu, X.; Shen, C.; Chen, D.; Guo, W.

2012-07-01

With the certain regulation of unified real estate registration taken by the Property Law and the step-by-step advance of simultaneous development in urban and rural in China, it is the premise and foundation to clearly specify property rights and their relations in promoting the integrated management of urban and rural land. This paper aims at developing a cadastral domain model oriented at unified real estate registration of China from the perspective of legal and spatial, which set up the foundation for unified real estate registration, and facilitates the effective interchange of cadastral information and the administration of land use. The legal cadastral model is provided based on the analysis of gap between current model and the demand of unified real estate registration, which implies the restrictions between different rights. Then the new cadastral domain model is constructed based on the legal cadastral domain model and CCDM (van Oosterom et al., 2006), which integrate real estate rights of urban land and rural land. Finally, the model is validated by a prototype system. The results show that the model is applicable for unified real estate registration in China.

A unified approach for determining the ultimate strength of RC members subjected to combined axial force, bending, shear and torsion

PubMed Central

Huang, Zhen

2017-01-01

This paper uses experimental investigation and theoretical derivation to study the unified failure mechanism and ultimate capacity model of reinforced concrete (RC) members under combined axial, bending, shear and torsion loading. Fifteen RC members are tested under different combinations of compressive axial force, bending, shear and torsion using experimental equipment designed by the authors. The failure mechanism and ultimate strength data for the four groups of tested RC members under different combined loading conditions are investigated and discussed in detail. The experimental research seeks to determine how the ultimate strength of RC members changes with changing combined loads. According to the experimental research, a unified theoretical model is established by determining the shape of the warped failure surface, assuming an appropriate stress distribution on the failure surface, and considering the equilibrium conditions. This unified failure model can be reasonably and systematically changed into well-known failure theories of concrete members under single or combined loading. The unified calculation model could be easily used in design applications with some assumptions and simplifications. Finally, the accuracy of this theoretical unified model is verified by comparisons with experimental results. PMID:28414777

Unifying concepts in the high school biology curriculum, one or many: An investigation of rural, suburban, and urban schools

NASA Astrophysics Data System (ADS)

Brown, Judith Ann

2000-10-01

Nine high school biology teachers from rural, suburban, and urban school settings, were interviewed about what idea, topic, or concept, if any, they use to unify their high school biology curriculum. Professional scientists and educational organizations have proposed that high school biology teachers use "biological evolution" as a unifying concept of their curriculum. Interviews, concept maps, and classroom syllabi and outlines were provided as data for these nine case studies. Each teacher was asked what topics were included in their curriculum to determine if a wide enough content was taught to warrant unification. The teachers' responses were compared to content and concepts listed in the National Science Content Standards, the Washington State Essential Academic Learning Requirements for Science, and a paper (Hurd, Bybee, Kahle, and Yager, 1980) that proposed what and how topics should be taught in the high school biology class by the year 2000. The nine teachers were asked to draw a concept map showing how these topics were interrelated and what concept, if any, "unified" them. A unifying concept is defined as a concept introduced early in the year and referred back to whenever new topics are introduced illustrating how the new topic is related to the previous ones through this unifying concept. Seven of the nine teachers did use at least one unifying concept. Two use evolution or natural selection, two use the web of life, two use the characteristics of life, and one uses scientific inquiry. The data collected in this study indicate high school teachers use these concepts such as the web of life and the characteristics of life because they believe they are easily understood by their students and less controversial than the theory of evolution. This study also presents evidence that school setting has minimal influence on what concept teachers use to unify their curriculum and that teachers have a significant amount of academic freedom to choose what they want to teach and how they want to teach it. The data suggests that teachers choose their unifying concept based on their personal beliefs of what their students will accept and on their past interactions with parents, students, and administrators when various unifying concepts were used.

20 CFR 661.240 - How do the unified planning requirements apply to the five-year strategic WIA and Wagner-Peyser...

Code of Federal Regulations, 2011 CFR

2011-04-01

... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false How do the unified planning requirements apply to the five-year strategic WIA and Wagner-Peyser plan and to other Department of Labor plans? 661... ACT State Governance Provisions § 661.240 How do the unified planning requirements apply to the five...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Yinan; Shi Handuo; Xiong Zhaoxi

We present a unified universal quantum cloning machine, which combines several different existing universal cloning machines together, including the asymmetric case. In this unified framework, the identical pure states are projected equally into each copy initially constituted by input and one half of the maximally entangled states. We show explicitly that the output states of those universal cloning machines are the same. One importance of this unified cloning machine is that the cloning procession is always the symmetric projection, which reduces dramatically the difficulties for implementation. Also, it is found that this unified cloning machine can be directly modified tomore » the general asymmetric case. Besides the global fidelity and the single-copy fidelity, we also present all possible arbitrary-copy fidelities.« less

Unified constitutive models for high-temperature structural applications

NASA Technical Reports Server (NTRS)

Lindholm, U. S.; Chan, K. S.; Bodner, S. R.; Weber, R. M.; Walker, K. P.

1988-01-01

Unified constitutive models are characterized by the use of a single inelastic strain rate term for treating all aspects of inelastic deformation, including plasticity, creep, and stress relaxation under monotonic or cyclic loading. The structure of this class of constitutive theory pertinent for high temperature structural applications is first outlined and discussed. The effectiveness of the unified approach for representing high temperature deformation of Ni-base alloys is then evaluated by extensive comparison of experimental data and predictions of the Bodner-Partom and the Walker models. The use of the unified approach for hot section structural component analyses is demonstrated by applying the Walker model in finite element analyses of a benchmark notch problem and a turbine blade problem.

The feasibility of solar reflector production from lunar materials for solar power in space

NASA Technical Reports Server (NTRS)

1990-01-01

Science Applications International Corporation (SAIC) investigated the feasibility of producing solar reflectors from indigenous lunar materials for solar power production on the moon. First, lunar construction materials and production processes were reviewed, and candidate materials for reflector production were identified. At the same time, lunar environmental conditions were reviewed for their effect on production of concentrators. Next, conceptual designs and fabrication methods were proposed and studied for production of dish concentrators and heliostats. Finally, fabrication testing was performed on small-scale models using earth analogs of lunar materials. Findings from this initial investigation indicate that production of concentrators from lunar materials may be an attractive approach for solar energy production on the moon. Further design and testing are required to determine the best techniques and approaches to optimize this concept. Four materials were identified as having high potential for solar reflector manufacture. These baseline materials were foamed glass, concrete with glass-fiber reinforcement, a glass-fiber/glass-melt composite, and an iron-glass sintered material.

Receiver System: Lessons Learned from Solar Two

NASA Astrophysics Data System (ADS)

Litwin, R. Z.

2002-03-01

The Boeing Company fabricated the Solar Two receiver as a subcontractor for the Solar Two project. The receiver absorbed sunlight reflected from the heliostat field. A molten-nitrate-salt heat transfer fluid was pumped from a storage tank at grade level, heated from 290 to 565DGC by the receiver mounted on top of a tower, then flowed back down into another storage tank. To make electricity, the hot salt was pumped through a steam generator to produce steam that powered a conventional Rankine steam turbine/generator. This evaluation identifies the most significant Solar Two receiver system lessons learned from the Mechanical Design, Instrumentation and Control, Panel Fabrication, Site Construction, Receiver System Operation, and Management from the perspective of the receiver designer/manufacturer. The lessons learned on the receiver system described here consist of two parts: the Problem and one or more identified Solutions. The appendix summarizes an inspection of the advanced receiver panel developed by Boeing that was installed and operated in the Solar Two receiver.

Solar thermal repowering utility value analysis. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, R.; Day, J.; Reed, B.

The retrofit of solar central receiver energy supply systems to existing steam-electric generating stations (repowering) is being considered as a major programmatic thrust by DOE. The determination of a government response appropriate to the opportunities of repowering is an important policy question, and is the major reason for the analysis. The study objective is to define a government role in repowering that constitutes an efficient program investment in pursuit of viable private markets for heliostat-based energy systems. In support of that objective, the study is designed to identify the scope and nature of the repowering opportunity within the larger contextmore » of its contributions to central receiver technology development and commercialization. The Supply and Integration Tasks are documented elsewhere. This report documents the Demand Task, determining and quantifying the sources of the value of repowering and of central receiver technology in general to electric utilities. The modeling tools and assumptions used in the Demand Task are described and the results are presented and interpreted. (MCW)« less

Receiver System: Lessons Learned From Solar Two

DOE Office of Scientific and Technical Information (OSTI.GOV)

LITWIN, ROBERT Z.; PACHECO, JAMES E.

The Boeing Company fabricated the Solar Two receiver as a subcontractor for the Solar Two project. The receiver absorbed sunlight reflected from the heliostat field. A molten-nitrate-salt heat transfer fluid was pumped from a storage tank at grade level, heated from 290 to 565 C by the receiver mounted on top of a tower, then flowed back down into another storage tank. To make electricity, the hot salt was pumped through a steam generator to produce steam that powered a conventional Rankine steam turbine/generator. This evaluation identifies the most significant Solar Two receiver system lessons learned from the Mechanical Design,more » Instrumentation and Control, Panel Fabrication, Site Construction, Receiver System Operation, and Management from the perspective of the receiver designer/manufacturer. The lessons learned on the receiver system described here consist of two parts: the Problem and one or more identified Solutions. The appendix summarizes an inspection of the advanced receiver panel developed by Boeing that was installed and operated in the Solar Two receiver.« less

Application of porous medium for efficiency improvement of a concentrated solar air heating system

NASA Astrophysics Data System (ADS)

Prasartkaew, Boonrit

2018-01-01

The objective of this study is to evaluate the thermal efficiency of a concentrated solar collector for a high temperature air heating system. The proposed system consists of a 25-m2 focused multi-flat-mirror solar heliostat equipped with a porous medium solar collector/receiver which was installed on the top of a 3-m tower, called ‘tower receiver’. To know how the system efficiency cloud be improved by using porous medium, the proposed system with and without porous medium were tested and the comparative study was performed. The experimental results reveal that, for the proposed system, application of porous medium is promising, the efficiency can be increased about 2 times compared to the conventional one. In addition, due to the porous medium used in this study was the waste material with very low cost. It can be summarized that the substantial efficiency improvement with very low investment cost of the proposed system seem to be a vital measures for addressing the energy issues.

Ceramic high temperature receiver design and tests

NASA Technical Reports Server (NTRS)

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.

Decomposition and control of complex systems - Application to the analysis and control of industrial and economic systems /energy production/ with limited supplies

NASA Astrophysics Data System (ADS)

de Coligny, M.

Optimized control strategies are developed for industrial installations where many variables of energy supply and storage are involved, with a particular focus on characteristics of a solar central tower power plant. It is shown that optimal regulation resides in controlling all disturbances which occur in a limited domain of the entire system, using robust control schemes. Choosing a command is then dependent on defining precise operational limits as constraints on the machines' performances. Attention is given to the development of variational principles used for the elements of the command logic. Particular consideration is given to a limited supply in storage in spatial and temporal terms. Commands for alterations in functions are then available on-line, and discontinuities are not a feature of the control system. The strategy is applied to the case of a field of heliostats and a central tower themal receiver showing that management is possible on the basis of a sliding horizon.

Solar central receiver reformer system for ammonia plants

NASA Astrophysics Data System (ADS)

1980-07-01

Details of the conceptual design, economic analysis, and development plan for a solar central receiver system for retrofitting the Valley Nitrogen Producers, Inc., El Centro, California 600 ST/SD Ammonia Plant are presented. The retrofit system consists of a solar central receiver reformer (SCRR) operating in parallel with the existing fossil fired reformer. Steam and hydrocarbon react in the catalyst filled tubes of the inner cavity receiver to form a hydrogen rich mixture which is the syngas feed for the ammonia production. The SCRR system displaces natural gas presently used in the fossil reformer combustion chamber. The solar reformer retrofit system characteristics and its interface with the existing plant are simple, incorporating state of the art components with proven technology. A northfield composed of one thousand forty second generation heliostats provides solar energy to the receiver which is positioned on top of a 90 meter high steel tower. The overall economics of this system can provide over 20% discount cash flow rate of return with proper investment and market conditions.

The Landsat Data Continuity Mission Operational Land Imager (OLI) Radiometric Calibration

NASA Technical Reports Server (NTRS)

Markham, Brian L.; Dabney, Philip W.; Murphy-Morris, Jeanine E.; Knight, Edward J.; Kvaran, Geir; Barsi, Julia A.

2010-01-01

The Operational Land Imager (OLI) on the Landsat Data Continuity Mission (LDCM) has a comprehensive radiometric characterization and calibration program beginning with the instrument design, and extending through integration and test, on-orbit operations and science data processing. Key instrument design features for radiometric calibration include dual solar diffusers and multi-lamped on-board calibrators. The radiometric calibration transfer procedure from NIST standards has multiple checks on the radiometric scale throughout the process and uses a heliostat as part of the transfer to orbit of the radiometric calibration. On-orbit lunar imaging will be used to track the instruments stability and side slither maneuvers will be used in addition to the solar diffuser to flat field across the thousands of detectors per band. A Calibration Validation Team is continuously involved in the process from design to operations. This team uses an Image Assessment System (IAS), part of the ground system to characterize and calibrate the on-orbit data.

Laser heterodyne system for obtaining height profiles of minor species in the atmosphere

NASA Technical Reports Server (NTRS)

Jain, S. L.; Saha, A. K.

1986-01-01

An infrared laser heterodyne system for obtaining height profiles of minor constituents of the atmosphere was developed and erected. A brief discription of the system is given. The system consists of a tunable CO2 waveguide laser in the 9 to 11 micrometer band, that is used as a local oscillator and a heliostat that follows the sun and brings in solar radiation, that is mixed with the laser beam in a high speed liquid nitrogen cooled mercury cadmium telluride detector. The detected signal is analysed in a RF spectrum analyser that allows tracing absorption line profiles. Absorption lines of a number of minor constituents in the troposphere and stratosphere, such as O3, NH3, H2O, SO2, ClO, N2O, are in the 9 to 11 micrometer band and overlap with that of CO2 laser range. The experimental system has been made operational and trial observations taken. Current measurements are limited to ozone height profiles. Results are presented.

Unified-theory-of-reinforcement neural networks do not simulate the blocking effect.

PubMed

Calvin, Nicholas T; J McDowell, J

2015-11-01

For the last 20 years the unified theory of reinforcement (Donahoe et al., 1993) has been used to develop computer simulations to evaluate its plausibility as an account for behavior. The unified theory of reinforcement states that operant and respondent learning occurs via the same neural mechanisms. As part of a larger project to evaluate the operant behavior predicted by the theory, this project was the first replication of neural network models based on the unified theory of reinforcement. In the process of replicating these neural network models it became apparent that a previously published finding, namely, that the networks simulate the blocking phenomenon (Donahoe et al., 1993), was a misinterpretation of the data. We show that the apparent blocking produced by these networks is an artifact of the inability of these networks to generate the same conditioned response to multiple stimuli. The piecemeal approach to evaluate the unified theory of reinforcement via simulation is critiqued and alternatives are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

A Radio Astronomy Curriculum for the Middle School Classroom

NASA Astrophysics Data System (ADS)

Davis, J.; Finley, D. G.

2000-12-01

In the summer of 2000, two teachers working on a Masters of Science Teaching program at New Mexico Institute of Mining and Technology, spent eight weeks as interns at the Array Operations Center for the National Radio Astronomy Observatory (NRAO) in Socorro, New Mexico, under the auspices of the National Science Foundation's (NSF) Research Experience for Teachers (RET) program. The resulting projects will directly benefit students in the indvidual classrooms, as well as provide an easy-to-access resource for other educators. One of the products is a Radio Astronomy Curriculum for upper middle school classes. Radio astronomy images, based on scientific research results using NRAO's Very Large Array, are featured on trading cards which include an explanation, a ``web challenge'', and in some cases, a comparison of radio and optical images. Each trading card has corresponding lesson plans with background information about the images and astronomy concepts needed to do the lessons. Comparison of optical and radio astronomy is used as much as possible to explain the information from research using visible and radio wavelengths. New Mexico's Content Standards and Benchmarks (developed using national standards) for science education was used as a guide for the activities. The three strands of science listed in the standards, Unifying Concepts and Processes, Science as Inquiry, and Science Content are addressed in the lessons. Higher level thinking and problem solving skills are featured throughout the curriculum. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc. The NSF's RET program is gratefully acknowledged.

Models of verbal working memory capacity: what does it take to make them work?

PubMed

Cowan, Nelson; Rouder, Jeffrey N; Blume, Christopher L; Saults, J Scott

2012-07-01

Theories of working memory (WM) capacity limits will be more useful when we know what aspects of performance are governed by the limits and what aspects are governed by other memory mechanisms. Whereas considerable progress has been made on models of WM capacity limits for visual arrays of separate objects, less progress has been made in understanding verbal materials, especially when words are mentally combined to form multiword units or chunks. Toward a more comprehensive theory of capacity limits, we examined models of forced-choice recognition of words within printed lists, using materials designed to produce multiword chunks in memory (e.g., leather brief case). Several simple models were tested against data from a variety of list lengths and potential chunk sizes, with test conditions that only imperfectly elicited the interword associations. According to the most successful model, participants retained about 3 chunks on average in a capacity-limited region of WM, with some chunks being only subsets of the presented associative information (e.g., leather brief case retained with leather as one chunk and brief case as another). The addition to the model of an activated long-term memory component unlimited in capacity was needed. A fixed-capacity limit appears critical to account for immediate verbal recognition and other forms of WM. We advance a model-based approach that allows capacity to be assessed despite other important processing contributions. Starting with a psychological-process model of WM capacity developed to understand visual arrays, we arrive at a more unified and complete model. Copyright 2012 APA, all rights reserved.

Models of Verbal Working Memory Capacity: What Does It Take to Make Them Work?

PubMed Central

Cowan, Nelson; Rouder, Jeffrey N.; Blume, Christopher L.; Saults, J. Scott

2013-01-01

Theories of working memory (WM) capacity limits will be more useful when we know what aspects of performance are governed by the limits and what aspects are governed by other memory mechanisms. Whereas considerable progress has been made on models of WM capacity limits for visual arrays of separate objects, less progress has been made in understanding verbal materials, especially when words are mentally combined to form multi-word units or chunks. Toward a more comprehensive theory of capacity limits, we examine models of forced-choice recognition of words within printed lists, using materials designed to produce multi-word chunks in memory (e.g., leather brief case). Several simple models were tested against data from a variety of list lengths and potential chunk sizes, with test conditions that only imperfectly elicited the inter-word associations. According to the most successful model, participants retained about 3 chunks on average in a capacity-limited region of WM, with some chunks being only subsets of the presented associative information (e.g., leather brief case retained with leather as one chunk and brief case as another). The addition to the model of an activated long-term memory (LTM) component unlimited in capacity was needed. A fixed capacity limit appears critical to account for immediate verbal recognition and other forms of WM. We advance a model-based approach that allows capacity to be assessed despite other important processing contributions. Starting with a psychological-process model of WM capacity developed to understand visual arrays, we arrive at a more unified and complete model. PMID:22486726

A unified approach to the analysis and design of elasto-plastic structures with mechanical contact

NASA Technical Reports Server (NTRS)

Bendsoe, Martin P.; Olhoff, Niels; Taylor, John E.

1990-01-01

With structural design in mind, a new unified variational model has been developed which represents the mechanics of deformation elasto-plasticity with unilateral contact conditions. For a design problem formulated as maximization of the load carrying capacity of a structure under certain constraints, the unified model allows for a simultaneous analysis and design synthesis for a whole range of mechanical behavior.

Review and Implementation Status of Prior Defense Business Board Recommendations

DTIC Science & Technology

2007-04-01

Resource Management • Support unified models for shared services , and be prepared to adjust forward approaches for a Unified Medical Command...models for shared services – including by and between Veterans Affairs and Defense, electronic information exchange, disease treatment and prevention...www.dod.mil/dbb/pdf/DBB- Report-on-the-Military.pdf. • Continue to support unified models for shared services – including by and between Veterans Affairs

Unified Research on Network-Based Hard/Soft Information Fusion

DTIC Science & Technology

2016-02-02

types). There are a number of search tree run parameters which must be set depending on the experimental setting. A pilot study was run to identify...Unlimited Final Report: Unified Research on Network-Based Hard/Soft Information Fusion The views, opinions and/or findings contained in this report...Final Report: Unified Research on Network-Based Hard/Soft Information Fusion Report Title The University at Buffalo (UB) Center for Multisource

77 FR 7663 - Introduction to the Unified Agenda of Federal Regulatory and Deregulatory Actions

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-13

...The Regulatory Flexibility Act requires that agencies publish semiannual regulatory agendas in the Federal Register describing regulatory actions they are developing that may have a significant economic impact on a substantial number of small entities (5 U.S.C. 602). Executive Order 12866 ``Regulatory Planning and Review,'' signed September 30, 1993 (58 FR 51735), and Office of Management and Budget memoranda implementing section 4 of that Order establish minimum standards for agencies' agendas, including specific types of information for each entry. The Unified Agenda of Federal Regulatory and Deregulatory Actions (Unified Agenda) helps agencies fulfill these requirements. All Federal regulatory agencies have chosen to publish their regulatory agendas as part of the Unified Agenda. Editions of the Unified Agenda prior to fall 2007 were printed in their entirety in the Federal Register. Beginning with the fall 2007 edition, the Internet is the basic means for conveying regulatory agenda information to the maximum extent legally permissible. The complete Unified Agenda for fall 2011, which contains the regulatory agendas for 59 Federal agencies, is available to the public at http:// reginfo.gov. The fall 2011 Unified Agenda publication appearing in the Federal Register consists of agency regulatory flexibility agendas, in accordance with the publication requirements of the Regulatory Flexibility Act. Agency regulatory flexibility agendas contain only those Agenda entries for rules that are likely to have a significant economic impact on a substantial number of small entities and entries that have been selected for periodic review under section 610 of the Regulatory Flexibility Act.

Concept of Draft International Standard for a Unified Approach to Space Program Quality Assurance

NASA Astrophysics Data System (ADS)

Stryzhak, Y.; Vasilina, V.; Kurbatov, V.

2002-01-01

For want of the unified approach to guaranteed space project and product quality assurance, implementation of many international space programs has become a challenge. Globalization of aerospace industry and participation of various international ventures with diverse quality assurance requirements in big international space programs requires for urgent generation of unified international standards related to this field. To ensure successful fulfillment of space missions, aerospace companies should design and process reliable and safe products with properties complying or bettering User's (or Customer's) requirements. Quality of the products designed or processed by subcontractors (or other suppliers) should also be in compliance with the main user (customer)'s requirements. Implementation of this involved set of unified requirements will be made possible by creating and approving a system (series) of international standards under a generic title Space Product Quality Assurance based on a system consensus principle. Conceptual features of the baseline standard in this system (series) should comprise: - Procedures for ISO 9000, CEN and ECSS requirements adaptation and introduction into space product creation, design, manufacture, testing and operation; - Procedures for quality assurance at initial (design) phases of space programs, with a decision on the end product made based on the principle of independence; - Procedures to arrange incoming inspection of products delivered by subcontractors (including testing, audit of supplier's procedures, review of supplier's documentation), and space product certification; - Procedures to identify materials and primary products applied; - Procedures for quality system audit at the component part, primary product and materials supplier facilities; - Unified procedures to form a list of basic performances to be under configuration management; - Unified procedures to form a list of critical space product components, and unified procedures to define risks related to the specific component application and evaluate safety for the entire program implementation. In the eyes of the authors, those features together with a number of other conceptual proposals should constitute a unified standard-technical basis for implementing international space programs.

Relevance, textual unity, and politeness in writing about science

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kreml, N.M.P.

1992-01-01

The question of whether there are social implications of linguistic choices in unifying a text is investigated empirically by this study which accounts for the interpretation of implicatures in conversation and written texts. It considers Relevance Theory (Sperber and Wilson 1988, Blakemore 1987, Blass 1990) to be the explanation of the unity of the text, as opposed to semantic theories of cohesion (Halliday and Hasan 1976) or pragmatic theories of coherence (van Dijk 1977). This study presents a model of three types of textual unifiers: overt (referring specifically to the text), embedded (referring to intra- and extra-textual information), and inferencemore » (not referring to the text at all). It hypothesizes that different genres are characterized by the predominance of different types of textual unifiers, and that readers will prefer those texts that rely on inferential unifiers which emphasize the reader's ability to participate in creating the meaning of the text. Eighteen texts of 275 words each are selected from three genres: scientific magazines, introductory science textbooks, and essays on science. The texts are found to vary significantly by genre in the type of textual unifier used. An Overtness Index expresses the ratio of the marked forms: science textbooks have more Overt unifiers (such as connective phrases) and thus a high Overtness Index; essays rely more on Inference unifiers (not represented by words) and thus have a low Overtness Index. The texts are submitted to 188 readers, and a significantly high number of all types of readers prefer the texts with the lower Overtness Indices-the essays. Thus a low Overtness Index is one feature of texts preferred by readers, supporting the hypotheses that genres of texts vary in the type of unifier used and that readers prefer texts that allow them to participate in constructing the meaning of the text.« less

Adaptive feedback synchronization of a unified chaotic system

NASA Astrophysics Data System (ADS)

Lu, Junan; Wu, Xiaoqun; Han, Xiuping; Lü, Jinhu

2004-08-01

This Letter further improves and extends the work of Wang et al. [Phys. Lett. A 312 (2003) 34]. In detailed, the linear feedback synchronization and adaptive feedback synchronization with only one controller for a unified chaotic system are discussed here. It is noticed that this unified system contains the noted Lorenz and Chen systems. Two chaotic synchronization theorems are attained. Also, numerical simulations are given to show the effectiveness of these methods.

Putting It All Together: Final Comments

DTIC Science & Technology

1988-05-19

about 10 s 0 0 ( Gy @® ®- =@ 10. Intended rationality ( 100 sec and up ) Figure 3: Soar as a unified theory of cognition . task. The problem then...GROUP Herb Simon. unified. theories of cognition ,- cognitive 7science; ac-hitectures; Soar,,,--p-- 19. ABSTRACT (Continue on reverse if necessary’,and...appreciation this paper is supposed to contribute, provide another. And a recent extended reflection by the author on Unified Theories of Cognition (The

Analysis of the Length of Braille Texts in English Braille American Edition, the Nemeth Code, and Computer Braille Code versus the Unified English Braille Code

ERIC Educational Resources Information Center

Knowlton, Marie; Wetzel, Robin

2006-01-01

This study compared the length of text in English Braille American Edition, the Nemeth code, and the computer braille code with the Unified English Braille Code (UEBC)--also known as Unified English Braille (UEB). The findings indicate that differences in the length of text are dependent on the type of material that is transcribed and the grade…

A Unified Fault-Tolerance Protocol

NASA Technical Reports Server (NTRS)

Miner, Paul; Gedser, Alfons; Pike, Lee; Maddalon, Jeffrey

2004-01-01

Davies and Wakerly show that Byzantine fault tolerance can be achieved by a cascade of broadcasts and middle value select functions. We present an extension of the Davies and Wakerly protocol, the unified protocol, and its proof of correctness. We prove that it satisfies validity and agreement properties for communication of exact values. We then introduce bounded communication error into the model. Inexact communication is inherent for clock synchronization protocols. We prove that validity and agreement properties hold for inexact communication, and that exact communication is a special case. As a running example, we illustrate the unified protocol using the SPIDER family of fault-tolerant architectures. In particular we demonstrate that the SPIDER interactive consistency, distributed diagnosis, and clock synchronization protocols are instances of the unified protocol.

14 CFR 1221.100 - Scope.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., and the Agency's Unified Visual Communications System § 1221.100 Scope. This subpart sets forth the... Unified Visual Communications System and prescribes the policy and guidelines for implementation of the...

Dysregulation of Mammalian Target of Rapamycin Signaling in Mouse Models of Autism.

PubMed

Huber, Kimberly M; Klann, Eric; Costa-Mattioli, Mauro; Zukin, R Suzanne

2015-10-14

The mammalian target of rapamycin (mTOR) is a central regulator of a diverse array of cellular processes, including cell growth, proliferation, autophagy, translation, and actin polymerization. Components of the mTOR cascade are present at synapses and influence synaptic plasticity and spine morphogenesis. A prevailing view is that the study of mTOR and its role in autism spectrum disorders (ASDs) will elucidate the molecular mechanisms by which mTOR regulates neuronal function under physiological and pathological conditions. Although many ASDs arise as a result of mutations in genes with multiple molecular functions, they appear to converge on common biological pathways that give rise to autism-relevant behaviors. Dysregulation of mTOR signaling has been identified as a phenotypic feature common to fragile X syndrome, tuberous sclerosis complex 1 and 2, neurofibromatosis 1, phosphatase and tensin homolog, and potentially Rett syndrome. Below are a summary of topics covered in a symposium that presents dysregulation of mTOR as a unifying theme in a subset of ASDs. Copyright © 2015 the authors 0270-6474/15/3513836-07$15.00/0.

The watershed-scale optimized and rearranged landscape design (WORLD) model and local biomass processing depots for sustainable biofuel production: Integrated life cycle assessments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eranki, Pragnya L.; Manowitz, David H.; Bals, Bryan D.

An array of feedstock is being evaluated as potential raw material for cellulosic biofuel production. Thorough assessments are required in regional landscape settings before these feedstocks can be cultivated and sustainable management practices can be implemented. On the processing side, a potential solution to the logistical challenges of large biorefi neries is provided by a network of distributed processing facilities called local biomass processing depots. A large-scale cellulosic ethanol industry is likely to emerge soon in the United States. We have the opportunity to influence the sustainability of this emerging industry. The watershed-scale optimized and rearranged landscape design (WORLD) modelmore » estimates land allocations for different cellulosic feedstocks at biorefinery scale without displacing current animal nutrition requirements. This model also incorporates a network of the aforementioned depots. An integrated life cycle assessment is then conducted over the unified system of optimized feedstock production, processing, and associated transport operations to evaluate net energy yields (NEYs) and environmental impacts.« less

The Standard Model: how far can it go and how can we tell?

PubMed

Butterworth, J M

2016-08-28

The Standard Model of particle physics encapsulates our current best understanding of physics at the smallest distances and highest energies. It incorporates quantum electrodynamics (the quantized version of Maxwell's electromagnetism) and the weak and strong interactions, and has survived unmodified for decades, save for the inclusion of non-zero neutrino masses after the observation of neutrino oscillations in the late 1990s. It describes a vast array of data over a wide range of energy scales. I review a selection of these successes, including the remarkably successful prediction of a new scalar boson, a qualitatively new kind of object observed in 2012 at the Large Hadron Collider. New calculational techniques and experimental advances challenge the Standard Model across an ever-wider range of phenomena, now extending significantly above the electroweak symmetry breaking scale. I will outline some of the consequences of these new challenges, and briefly discuss what is still to be found.This article is part of the themed issue 'Unifying physics and technology in light of Maxwell's equations'. © 2016 The Author(s).

Multidisciplinary approaches to understanding collective cell migration in developmental biology.

PubMed

Schumacher, Linus J; Kulesa, Paul M; McLennan, Rebecca; Baker, Ruth E; Maini, Philip K

2016-06-01

Mathematical models are becoming increasingly integrated with experimental efforts in the study of biological systems. Collective cell migration in developmental biology is a particularly fruitful application area for the development of theoretical models to predict the behaviour of complex multicellular systems with many interacting parts. In this context, mathematical models provide a tool to assess the consistency of experimental observations with testable mechanistic hypotheses. In this review, we showcase examples from recent years of multidisciplinary investigations of neural crest cell migration. The neural crest model system has been used to study how collective migration of cell populations is shaped by cell-cell interactions, cell-environmental interactions and heterogeneity between cells. The wide range of emergent behaviours exhibited by neural crest cells in different embryonal locations and in different organisms helps us chart out the spectrum of collective cell migration. At the same time, this diversity in migratory characteristics highlights the need to reconcile or unify the array of currently hypothesized mechanisms through the next generation of experimental data and generalized theoretical descriptions. © 2016 The Authors.

Description of waves in inhomogeneous domains using Heun's equation

NASA Astrophysics Data System (ADS)

Bednarik, M.; Cervenka, M.

2018-04-01

There are a number of model equations describing electromagnetic, acoustic or quantum waves in inhomogeneous domains and some of them are of the same type from the mathematical point of view. This isomorphism enables us to use a unified approach to solving the corresponding equations. In this paper, the inhomogeneity is represented by a trigonometric spatial distribution of a parameter determining the properties of an inhomogeneous domain. From the point of view of modeling, this trigonometric parameter function can be smoothly connected to neighboring constant-parameter regions. For this type of distribution, exact local solutions of the model equations are represented by the local Heun functions. As the interval for which the solution is sought includes two regular singular points. For this reason, a method is proposed which resolves this problem only based on the local Heun functions. Further, the transfer matrix for the considered inhomogeneous domain is determined by means of the proposed method. As an example of the applicability of the presented solutions the transmission coefficient is calculated for the locally periodic structure which is given by an array of asymmetric barriers.

Semantic web data warehousing for caGrid.

PubMed

McCusker, James P; Phillips, Joshua A; González Beltrán, Alejandra; Finkelstein, Anthony; Krauthammer, Michael

2009-10-01

The National Cancer Institute (NCI) is developing caGrid as a means for sharing cancer-related data and services. As more data sets become available on caGrid, we need effective ways of accessing and integrating this information. Although the data models exposed on caGrid are semantically well annotated, it is currently up to the caGrid client to infer relationships between the different models and their classes. In this paper, we present a Semantic Web-based data warehouse (Corvus) for creating relationships among caGrid models. This is accomplished through the transformation of semantically-annotated caBIG Unified Modeling Language (UML) information models into Web Ontology Language (OWL) ontologies that preserve those semantics. We demonstrate the validity of the approach by Semantic Extraction, Transformation and Loading (SETL) of data from two caGrid data sources, caTissue and caArray, as well as alignment and query of those sources in Corvus. We argue that semantic integration is necessary for integration of data from distributed web services and that Corvus is a useful way of accomplishing this. Our approach is generalizable and of broad utility to researchers facing similar integration challenges.

A real-time spike sorting method based on the embedded GPU.

PubMed

Zelan Yang; Kedi Xu; Xiang Tian; Shaomin Zhang; Xiaoxiang Zheng

2017-07-01

Microelectrode arrays with hundreds of channels have been widely used to acquire neuron population signals in neuroscience studies. Online spike sorting is becoming one of the most important challenges for high-throughput neural signal acquisition systems. Graphic processing unit (GPU) with high parallel computing capability might provide an alternative solution for increasing real-time computational demands on spike sorting. This study reported a method of real-time spike sorting through computing unified device architecture (CUDA) which was implemented on an embedded GPU (NVIDIA JETSON Tegra K1, TK1). The sorting approach is based on the principal component analysis (PCA) and K-means. By analyzing the parallelism of each process, the method was further optimized in the thread memory model of GPU. Our results showed that the GPU-based classifier on TK1 is 37.92 times faster than the MATLAB-based classifier on PC while their accuracies were the same with each other. The high-performance computing features of embedded GPU demonstrated in our studies suggested that the embedded GPU provide a promising platform for the real-time neural signal processing.

Development and application of unified algorithms for problems in computational science

NASA Technical Reports Server (NTRS)

Shankar, Vijaya; Chakravarthy, Sukumar

1987-01-01

A framework is presented for developing computationally unified numerical algorithms for solving nonlinear equations that arise in modeling various problems in mathematical physics. The concept of computational unification is an attempt to encompass efficient solution procedures for computing various nonlinear phenomena that may occur in a given problem. For example, in Computational Fluid Dynamics (CFD), a unified algorithm will be one that allows for solutions to subsonic (elliptic), transonic (mixed elliptic-hyperbolic), and supersonic (hyperbolic) flows for both steady and unsteady problems. The objectives are: development of superior unified algorithms emphasizing accuracy and efficiency aspects; development of codes based on selected algorithms leading to validation; application of mature codes to realistic problems; and extension/application of CFD-based algorithms to problems in other areas of mathematical physics. The ultimate objective is to achieve integration of multidisciplinary technologies to enhance synergism in the design process through computational simulation. Specific unified algorithms for a hierarchy of gas dynamics equations and their applications to two other areas: electromagnetic scattering, and laser-materials interaction accounting for melting.

A Virtual Science Data Environment for Carbon Dioxide Observations

NASA Astrophysics Data System (ADS)

Verma, R.; Goodale, C. E.; Hart, A. F.; Law, E.; Crichton, D. J.; Mattmann, C. A.; Gunson, M. R.; Braverman, A. J.; Nguyen, H. M.; Eldering, A.; Castano, R.; Osterman, G. B.

2011-12-01

Climate science data are often distributed cross-institutionally and made available using heterogeneous interfaces. With respect to observational carbon-dioxide (CO2) records, these data span across national as well as international institutions and are typically distributed using a variety of data standards. Such an arrangement can yield challenges from a research perspective, as users often need to independently aggregate datasets as well as address the issue of data quality. To tackle this dispersion and heterogeneity of data, we have developed the CO2 Virtual Science Data Environment - a comprehensive approach to virtually integrating CO2 data and metadata from multiple missions and providing a suite of computational services that facilitate analysis, comparison, and transformation of that data. The Virtual Science Environment provides climate scientists with a unified web-based destination for discovering relevant observational data in context, and supports a growing range of online tools and services for analyzing and transforming the available data to suit individual research needs. It includes web-based tools to geographically and interactively search for CO2 observations collected from multiple airborne, space, as well as terrestrial platforms. Moreover, the data analysis services it provides over the Internet, including offering techniques such as bias estimation and spatial re-gridding, move computation closer to the data and reduce the complexity of performing these operations repeatedly and at scale. The key to enabling these services, as well as consolidating the disparate data into a unified resource, has been to focus on leveraging metadata descriptors as the foundation of our data environment. This metadata-centric architecture, which leverages the Dublin Core standard, forgoes the need to replicate remote datasets locally. Instead, the system relies upon an extensive, metadata-rich virtual data catalog allowing on-demand browsing and retrieval of CO2 records from multiple missions. In other words, key metadata information about remote CO2 records is stored locally while the data itself is preserved at its respective archive of origin. This strategy has been made possible by our method of encapsulating the heterogeneous sources of data using a common set of web-based services, including services provided by Jet Propulsion Laboratory's Climate Data Exchange (CDX). Furthermore, this strategy has enabled us to scale across missions, and to provide access to a broad array of CO2 observational data. Coupled with on-demand computational services and an intuitive web-portal interface, the CO2 Virtual Science Data Environment effectively transforms heterogeneous CO2 records from multiple sources into a unified resource for scientific discovery.

User's manual for UCAP: Unified Counter-Rotation Aero-Acoustics Program

NASA Technical Reports Server (NTRS)

Culver, E. M.; Mccolgan, C. J.

1993-01-01

This is the user's manual for the Unified Counter-rotation Aeroacoustics Program (UCAP), the counter-rotation derivative of the UAAP (Unified Aero-Acoustic Program). The purpose of this program is to predict steady and unsteady air loading on the blades and the noise produced by a counter-rotation Prop-Fan. The aerodynamic method is based on linear potential theory with corrections for nonlinearity associated with axial flux induction, vortex lift on the blades, and rotor-to-rotor interference. The theory for acoustics and the theory for individual blade loading and wakes are derived in Unified Aeroacoustics Analysis for High Speed Turboprop Aerodynamics and Noise, Volume 1 (NASA CR-4329). This user's manual also includes a brief explanation of the theory used for the modelling of counter-rotation.

User's manual for UCAP: Unified Counter-Rotation Aero-Acoustics Program

NASA Astrophysics Data System (ADS)

Culver, E. M.; McColgan, C. J.

1993-04-01

This is the user's manual for the Unified Counter-rotation Aeroacoustics Program (UCAP), the counter-rotation derivative of the UAAP (Unified Aero-Acoustic Program). The purpose of this program is to predict steady and unsteady air loading on the blades and the noise produced by a counter-rotation Prop-Fan. The aerodynamic method is based on linear potential theory with corrections for nonlinearity associated with axial flux induction, vortex lift on the blades, and rotor-to-rotor interference. The theory for acoustics and the theory for individual blade loading and wakes are derived in Unified Aeroacoustics Analysis for High Speed Turboprop Aerodynamics and Noise, Volume 1 (NASA CR-4329). This user's manual also includes a brief explanation of the theory used for the modelling of counter-rotation.

Analytic dyon solution in SU/N/ grand unified theories

NASA Astrophysics Data System (ADS)

Lyi, W. S.; Park, Y. J.; Koh, I. G.; Kim, Y. D.

1982-10-01

Analytic solutions which are regular everywhere, including at the origin, are found for certain cases of SU(N) grand unified theories. Attention is restricted to order-1/g behavior of the SU(N) grand unified theory, and aspects of the solutions of the Higgs field of the SU(N) near the origin are considered. Comments regarding the mass, the Pontryagin-like index of the dyon, and magnetic charge are made with respect to the recent report of a monopole discovery.

Unification of multiqubit polygamy inequalities

NASA Astrophysics Data System (ADS)

Kim, Jeong San

2012-03-01

I establish a unified view of polygamy of multiqubit entanglement. I first introduce a two-parameter generalization of the entanglement of assistance, namely, the unified entanglement of assistance for bipartite quantum states, and provide an analytic lower bound in two-qubit systems. I show a broad class of polygamy inequalities of multiqubit entanglement in terms of the unified entanglement of assistance that encapsulates all known multiqubit polygamy inequalities as special cases. I further show that this class of polygamy inequalities can be improved into tighter inequalities for three-qubit systems.

Technical writing practically unified through industry

NASA Technical Reports Server (NTRS)

Houston, L. S.

1981-01-01

General background details in the development of a university level technical writing program, based upon the writing tasks of the student's occupations, are summarized. Objectives and methods for unifying the courses of study with the needs of industry are discussed. Four academic course divisions, Industries Technologies, in which preparation and training are offered are: Animal, Horticulture, Agriculture, and Agricultural Business. Occupational competence is cited as the main goal for these programs in which technical writing is to be practically unified through industry. Course descriptions are also provided.

Unified space--time trigonometry and its applications to relativistic kinematics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaccarini, A.

1973-06-15

A geometrical approach to relativistic kinematics is presented. Owing to a unified space-time trigonometry, the spherical trigonometry formalism may be used to describe and study the kinematics of any collision process. Lorentz transformations may thus lie treated as purely geometrical problems. A different way to define a unified trigonometry is also proposed, which is based on the spinor representation of the Lorentz group. This leads to a different and more general formalism than the former one. (auth)

76 FR 19893 - Unified Command Plan 2011

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-08

... Plan 2011 Memorandum for the Secretary of Defense Pursuant to my authority as Commander in Chief, I hereby approve and direct the implementation of the revised Unified Command Plan. Consistent with title...

OPUS - Outer Planets Unified Search with Enhanced Surface Geometry Parameters - Not Just for Rings

NASA Astrophysics Data System (ADS)

Gordon, Mitchell; Showalter, Mark Robert; Ballard, Lisa; Tiscareno, Matthew S.; Heather, Neil

2016-10-01

In recent years, with the massive influx of data into the PDS from a wide array of missions and instruments, finding the precise data you need has been an ongoing challenge. For remote sensing data obtained from Jupiter to Pluto, that challenge is being addressed by the Outer Planets Unified Search, more commonly known as OPUS.OPUS is a powerful search tool available at the PDS Ring-Moon Systems Node (RMS) - formerly the PDS Rings Node. While OPUS was originally designed with ring data in mind, its capabilities have been extended to include all of the targets within an instrument's field of view. OPUS provides preview images of search results, and produces a zip file for easy download of selected products, including a table of user specified metadata. For Cassini ISS and Voyager ISS we have generated and include calibrated versions of every image.Currently OPUS supports data returned by Cassini ISS, UVIS, VIMS, and CIRS (Saturn data through June 2010), New Horizons Jupiter LORRI, Galileo SSI, Voyager ISS and IRIS, and Hubble (ACS, WFC3 and WFPC2).At the RMS Node, we have developed and incorporated into OPUS detailed geometric metadata, based on the most recent SPICE kernels, for all of the bodies in the Cassini Saturn observations. This extensive set of geometric metadata is unique to the RMS Node and enables search constraints such as latitudes and longitudes (Saturn, Titan, and icy satellites), viewing and illumination geometry (phase, incidence and emission angles), and distances and resolution.Our near term plans include adding the full set of Cassini CIRS Saturn data (with enhanced geometry), New Horizons MVIC Jupiter encounter images, New Horizons LORRI and MVIC Pluto data, HST STIS observations, and Cassini and Voyager ring occultations. We also plan to develop enhanced geometric metadata for the New Horizons LORRI and MVIC instruments for both the Jupiter and the Pluto encounters.OPUS: http://pds-rings.seti.org/search/

Improving Focal Depth Estimates: Studies of Depth Phase Detection at Regional Distances

NASA Astrophysics Data System (ADS)

Stroujkova, A.; Reiter, D. T.; Shumway, R. H.

2006-12-01

The accurate estimation of the depth of small, regionally recorded events continues to be an important and difficult explosion monitoring research problem. Depth phases (free surface reflections) are the primary tool that seismologists use to constrain the depth of a seismic event. When depth phases from an event are detected, an accurate source depth is easily found by using the delay times of the depth phases relative to the P wave and a velocity profile near the source. Cepstral techniques, including cepstral F-statistics, represent a class of methods designed for the depth-phase detection and identification; however, they offer only a moderate level of success at epicentral distances less than 15°. This is due to complexities in the Pn coda, which can lead to numerous false detections in addition to the true phase detection. Therefore, cepstral methods cannot be used independently to reliably identify depth phases. Other evidence, such as apparent velocities, amplitudes and frequency content, must be used to confirm whether the phase is truly a depth phase. In this study we used a variety of array methods to estimate apparent phase velocities and arrival azimuths, including beam-forming, semblance analysis, MUltiple SIgnal Classification (MUSIC) (e.g., Schmidt, 1979), and cross-correlation (e.g., Cansi, 1995; Tibuleac and Herrin, 1997). To facilitate the processing and comparison of results, we developed a MATLAB-based processing tool, which allows application of all of these techniques (i.e., augmented cepstral processing) in a single environment. The main objective of this research was to combine the results of three focal-depth estimation techniques and their associated standard errors into a statistically valid unified depth estimate. The three techniques include: 1. Direct focal depth estimate from the depth-phase arrival times picked via augmented cepstral processing. 2. Hypocenter location from direct and surface-reflected arrivals observed on sparse networks of regional stations using a Grid-search, Multiple-Event Location method (GMEL; Rodi and Toksöz, 2000; 2001). 3. Surface-wave dispersion inversion for event depth and focal mechanism (Herrmann and Ammon, 2002). To validate our approach and provide quality control for our solutions, we applied the techniques to moderated- sized events (mb between 4.5 and 6.0) with known focal mechanisms. We illustrate the techniques using events observed at regional distances from the KSAR (Wonju, South Korea) teleseismic array and other nearby broadband three-component stations. Our results indicate that the techniques can produce excellent agreement between the various depth estimates. In addition, combining the techniques into a "unified" estimate greatly reduced location errors and improved robustness of the solution, even if results from the individual methods yielded large standard errors.

75 FR 4442 - Sunshine Act Meetings; Unified Carrier Registration Plan Board of Directors

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-27

.... PLACE: This meeting will take place telephonically. Any interested person may call Mr. Avelino Gutierrez... Board. FOR FURTHER INFORMATION CONTACT: Mr. Avelino Gutierrez, Chair, Unified Carrier Registration Board...

Unified theory of motion of inner planets

NASA Astrophysics Data System (ADS)

Kotelnikov, V.; Kislik, M.

1983-01-01

A highly accurate, unified theory of motion for the Solar System's inner planets Mercury, Venus, the Earth, Mars was developed. It has practical importance and is used to solve various problems of interplanetary cosmonautics.

The utilization of unified protocols in behavioral cognitive therapy in transdiagnostic group subjects: A clinical trial.

PubMed

de Ornelas Maia, Ana Claudia Corrêa; Nardi, Antonio Egidio; Cardoso, Adriana

2015-02-01

The practicing of protocols based on behavioral cognitive therapy (CBT) have been frequently used in the last decades and adapted to better manage the necessities of patients and providers. The goal is to build a treatment that is evidence-based - for that reason the unified protocol for multiple emotional disorders (transdiagnostics) have been utilized to simplify treatment - without losing scientific traits. The main goal of this study is to evaluate the unified protocol in groups of patients with depression and anxiety disorders. In a pool of 48 subjects, divided in two groups, one was submitted to 12 intervention sessions of the unified protocol while the other was solely given medication. MINI, BAI and BDI were the instruments used at the beginning and at the end of treatment. The results were highly significant (p<0.001) in as much as with the improvement of anxiety and depressive disorders as it was in the group which was treated with the unified protocol compared with the group which was only given medication Limitations of this study were the number of sample participants and the non-randomization of subjects in both groups. Group therapy has not been largely implemented though it is deemed very useful for treatments when the unified protocol is used in transdiagnostic patients. Not only does it allow for emotional stabilizing and socialization but it also enables subjects with an altruistic feeling amongst themselves. Copyright © 2014 Elsevier B.V. All rights reserved.

The three constituencies of the state: why the state has lost unifying energy.

PubMed

King, Desmond; Le Galès, Patrick

2017-11-01

We address resurgent populism by examining structural processes of state transformation in the UK, the US and France. Scholars stress the 'unifying energy of the state', a set of institutions and policies capable of limiting inequalities and defending legal regimes. One characteristic of modern Western statehood were packages of policies designed to integrate social groups and territories in part by ensuring common standards of provision and social citizenship across the nation state. This echoes James Scott's critical analysis of the modernist project of the state (1998). This 'unifying energy' had different origins including nationalist movements, combatting external influence or powers, war, and preparing citizens for the rigours of industrialization. Overcoming class differences and territorial differences (including cultural, social and economic differences) was a major source of mobilization to feed this 'unifying energy of the state' in France, Italy or Spain for instance. Political and cultural identities are related in significant part to respective nation states. We argue that this 'unifying energy' was an essential component of statehood in Europe and in the US. It is now largely lost. We explain why and the significance of its displacement. © London School of Economics and Political Science 2017.

75 FR 21719 - Sunshine Act Meetings; Unified Carrier Registration Plan Board of Directors

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-26

... will take place telephonically. Any interested person may call Mr. Avelino Gutierrez at (505) 827-4565... INFORMATION CONTACT: Mr. Avelino Gutierrez, Chair, Unified Carrier Registration Board of Directors at (505...

75 FR 35124 - Sunshine Act Meetings; Unified Carrier Registration Plan Board of Directors

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2010-06-21

... will take place telephonically. Any interested person may call Mr. Avelino Gutierrez at (505) 827-4565.... FOR FURTHER INFORMATION CONTACT: Mr. Avelino Gutierrez, Chair, Unified Carrier Registration Board of...

75 FR 9275 - Sunshine Act Meetings; Unified Carrier Registration Plan Board of Directors

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-01

... meeting will take place telephonically. Any interested person may call Mr. Avelino Gutierrez at (505) 827... INFORMATION CONTACT: Mr. Avelino Gutierrez, Chair, Unified Carrier Registration Board of Directors at (505...

75 FR 13336 - Sunshine Act Meetings; Unified Carrier Registration Plan Board of Directors

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-19

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75 FR 47679 - Sunshine Act Meetings; Unified Carrier Registration Plan Board of Directors

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-06

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Design Optimization for Interferometric Space-Based 21-cm Power Spectrum Measurements

NASA Astrophysics Data System (ADS)

Pober, Jonathan

2018-06-01

Observations of the highly-redshifted 21 cm hyperfine line of neutral hydrogen (HI) are one of the most promising probes for the future of cosmology. At redshifts z > 30, the HI signal is likely the only measurable emission, as luminous objects have yet to form. At these very low radio frequencies, however, the earth’s ionosphere becomes opaque — necessitating observations from space. The major challenge to neutral hydrogen cosmology (at all redshifts) lies in the presence of bright foreground emission, which can dominate the HI signal by as much as eight orders of magnitude at the highest redshifts. The only method for extracting the cosmological signal relies on the spectral smoothness of the foregrounds; since each frequency of the HI signal probes a different redshift, the cosmological emission is essentially uncorrelated from frequency to frequency. The key challenge for designing an experiment lies in maintaining the spectral smoothness of the foregrounds. If the frequency response of the instrument introduces spectral structure (or at least, a residual that cannot be calibrated out at the necessary precision), it quickly becomes impossible to distinguish the cosmological signal from the foregrounds. This principle has guided the design of ground-based experiments like the Precision Array for Probing the Epoch of Reionization (PAPER) and the Hydrogen Epoch of Reionization Array (HERA). However, there still exists no unifying framework for turning this design "philosophy" into a robust, quantitative set of performance metrics and specifications. In this talk, I will present updates on the efforts of my research group to translate lessons learned from ground-based experiments into a fully traceable set of mission requirements for Cosmic Dawn Mapper or other space-based 21 cm interferometer.

Unifying distribution functions: some lesser known distributions.

PubMed

Moya-Cessa, J R; Moya-Cessa, H; Berriel-Valdos, L R; Aguilar-Loreto, O; Barberis-Blostein, P

2008-08-01

We show that there is a way to unify distribution functions that describe simultaneously a classical signal in space and (spatial) frequency and position and momentum for a quantum system. Probably the most well known of them is the Wigner distribution function. We show how to unify functions of the Cohen class, Rihaczek's complex energy function, and Husimi and Glauber-Sudarshan distribution functions. We do this by showing how they may be obtained from ordered forms of creation and annihilation operators and by obtaining them in terms of expectation values in different eigenbases.

[Arabian food pyramid: unified framework for nutritional health messages].

PubMed

Shokr, Adel M

2008-01-01

There are several ways to present nutritional health messages, particularly pyramidic indices, but they have many deficiencies such as lack of agreement on a unified or clear methodology for food grouping and ignoring nutritional group inter-relation and integration. This causes confusion for health educators and target individuals. This paper presents an Arabian food pyramid that aims to unify the bases of nutritional health messages, bringing together the function, contents, source and nutritional group servings and indicating the inter-relation and integration of nutritional groups. This provides comprehensive, integrated, simple and flexible health messages.

The research and implementation of a unified identity authentication in e-government network

NASA Astrophysics Data System (ADS)

Feng, Zhou

Current problem existing in e-government network is that the applications of information system are developed independently by various departments, and each has its own specific set of authentication and access control mechanism. To build a comprehensive information system in favor of sharing and exchanging information, a sound and secure unified e-government authentication system is firstly needed. The paper, combining with practical development of e-government network, carries out a thorough discussion on how to achieve data synchronization between unified authentication system and related application systems.

Sensing, Control, and System Integration for Autonomous Vehicles: A Series of Challenges

NASA Astrophysics Data System (ADS)

Özgüner, Ümit; Redmill, Keith

One of the important examples of mechatronic systems can be found in autonomous ground vehicles. Autonomous ground vehicles provide a series of challenges in sensing, control and system integration. In this paper we consider off-road autonomous vehicles, automated highway systems and urban autonomous driving and indicate the unifying aspects. We specifically consider our own experience during the last twelve years in various demonstrations and challenges in attempting to identify unifying themes. Such unifying themes can be observed in basic hierarchies, hybrid system control approaches and sensor fusion techniques.

A Unified Mathematical Definition of Classical Information Retrieval.

ERIC Educational Resources Information Center

Dominich, Sandor

2000-01-01

Presents a unified mathematical definition for the classical models of information retrieval and identifies a mathematical structure behind relevance feedback. Highlights include vector information retrieval; probabilistic information retrieval; and similarity information retrieval. (Contains 118 references.) (Author/LRW)

Unified planning work program federal fiscal year 2008

DOT National Transportation Integrated Search

2008-01-01

This Unified Planning Work Program (UPWP) contains information about surface-transportation planning projects that will be conducted in the Boston metropolitan region during the period of October 1, 2007, through September 30, 2008 (federal fiscal ye...

Unified implementation of the reference architecture : concept of operations.

DOT National Transportation Integrated Search

2015-10-19

This document describes the Concept of Operations (ConOps) for the Unified Implementation of the Reference Architecture, located in Southeast Michigan, which supports connected vehicle research and development. This ConOps describes the current state...

75 FR 30900 - Sunshine Act Meetings; Unified Carrier Registration Plan Board of Directors

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-02

.... Avelino Gutierrez at (505) 827-4565 to receive the toll free number and pass code needed to participate in... Board. FOR FURTHER INFORMATION CONTACT: Mr. Avelino Gutierrez, Chair, Unified Carrier Registration Board...

a Unified Matrix Polynomial Approach to Modal Identification

NASA Astrophysics Data System (ADS)

Allemang, R. J.; Brown, D. L.

1998-04-01

One important current focus of modal identification is a reformulation of modal parameter estimation algorithms into a single, consistent mathematical formulation with a corresponding set of definitions and unifying concepts. Particularly, a matrix polynomial approach is used to unify the presentation with respect to current algorithms such as the least-squares complex exponential (LSCE), the polyreference time domain (PTD), Ibrahim time domain (ITD), eigensystem realization algorithm (ERA), rational fraction polynomial (RFP), polyreference frequency domain (PFD) and the complex mode indication function (CMIF) methods. Using this unified matrix polynomial approach (UMPA) allows a discussion of the similarities and differences of the commonly used methods. the use of least squares (LS), total least squares (TLS), double least squares (DLS) and singular value decomposition (SVD) methods is discussed in order to take advantage of redundant measurement data. Eigenvalue and SVD transformation methods are utilized to reduce the effective size of the resulting eigenvalue-eigenvector problem as well.

Unified Phase Diagram for Iron-Based Superconductors.

PubMed

Gu, Yanhong; Liu, Zhaoyu; Xie, Tao; Zhang, Wenliang; Gong, Dongliang; Hu, Ding; Ma, Xiaoyan; Li, Chunhong; Zhao, Lingxiao; Lin, Lifang; Xu, Zhuang; Tan, Guotai; Chen, Genfu; Meng, Zi Yang; Yang, Yi-Feng; Luo, Huiqian; Li, Shiliang

2017-10-13

High-temperature superconductivity is closely adjacent to a long-range antiferromagnet, which is called a parent compound. In cuprates, all parent compounds are alike and carrier doping leads to superconductivity, so a unified phase diagram can be drawn. However, the properties of parent compounds for iron-based superconductors show significant diversity and both carrier and isovalent dopings can cause superconductivity, which casts doubt on the idea that there exists a unified phase diagram for them. Here we show that the ordered moments in a variety of iron pnictides are inversely proportional to the effective Curie constants of their nematic susceptibility. This unexpected scaling behavior suggests that the magnetic ground states of iron pnictides can be achieved by tuning the strength of nematic fluctuations. Therefore, a unified phase diagram can be established where superconductivity emerges from a hypothetical parent compound with a large ordered moment but weak nematic fluctuations, which suggests that iron-based superconductors are strongly correlated electron systems.

Neurological exclusiveness or unified science inclusiveness: Comment on Schwartz et al. (2016).

PubMed

Staats, Arthur W

2016-12-01

Schwartz, Lilienfeld, Meca, and Sauvigné (2016) argue effectively and productively that neuroscience is monistic (excludes other fields) in a way that affects negatively psychology department makeup, psychology grant support, and the way students are trained. They conclude, rather, that it is important to effect an inclusion of different fields of psychology. This paper broadens and strengthens their position. However, it also points out that a call for inclusiveness raises a central question. How is inclusiveness to be accomplished? Without stipulation to the contrary the call is for an eclecticism. As Schwartz et al. indicate, unified theory is now rejected because grand theory in the past has been monistic. However, science moves on; there are unified theories today that are inclusive. Thus, development of an area in psychology is needed that studies, evaluates, and advances works that unify inclusively, the present article being an example. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Hard X-ray tests of the unified model for an ultraviolet-detected sample of Seyfert 2 galaxies

NASA Technical Reports Server (NTRS)

Mulchaey, John S.; Myshotzky, Richard F.; Weaver, Kimberly A.

1992-01-01

An ultraviolet-detected sample of Seyfert 2 galaxies shows heavy photoelectric absorption in the hard X-ray band. The presence of UV emission combined with hard X-ray absorption argues strongly for a special geometry which must have the general properties of the Antonucci and Miller unified model. The observations of this sample are consistent with the picture in which the hard X-ray photons are viewed directly through the obscuring matter (molecular torus?) and the optical, UV, and soft X-ray continuum are seen in scattered light. The large range in X-ray column densities implies that there must be a large variation in intrinsic thicknesses of molecular tori, an assumption not found in the simplest of unified models. Furthermore, constraints based on the cosmic X-ray background suggest that some of the underlying assumptions of the unified model are wrong.

Global bioethics -- myth or reality?

PubMed

Holm, Søren; Williams-Jones, Bryn

2006-09-11

There has been debate on whether a global or unified field of bioethics exists. If bioethics is a unified global field, or at the very least a closely shared way of thinking, then we should expect bioethicists to behave the same way in their academic activities anywhere in the world. This paper investigates whether there is a 'global bioethics' in the sense of a unified academic community. To address this question, we study the web-linking patterns of bioethics institutions, the citation patterns of bioethics papers and the buying patterns of bioethics books. All three analyses indicate that there are geographical and institutional differences in the academic behavior of bioethicists and bioethics institutions. These exploratory studies support the position that there is no unified global field of bioethics. This is a problem if the only reason is parochialism. But these regional differences are probably of less concern if one notices that bioethics comes in many not always mutually understandable dialects.

Pregnancy complications in Brazilian puerperal women treated in the public and private health systems 1

PubMed Central

Varela, Patrícia Louise Rodrigues; de Oliveira, Rosana Rosseto; Melo, Emiliana Cristina; Mathias, Thais Aidar de Freitas

2018-01-01

ABSTRACT Objective: to analyze the prevalence of pregnancy complications and sociodemographic profile of puerperal patients with complications, according to the form of financing of the childbirth service. Method: cross-sectional study with interview of 928 puerperal women whose childbirth was financed by the Unified Health System, health plans and private sources (other sources than the Unified Health System). The sample was calculated based on the births registered in the Information System on Live Births, stratified by hospital and form of financing of the childbirth service. Data were analyzed using the chi-square and Fisher’s exact tests. Results: the prevalence was 87.8% for all puerperal women, with an average of 2.4 complications per woman. In the case of deliveries covered by the Unified Health System, urinary tract infection (38.2%), anemia (26.0%) and leucorrhea (23.5%) were more frequent. In turn, vaginal bleeding (26.4%), urinary tract infection (23.9%) and leucorrhoea (23.7%) were prevalent in deliveries that were not covered by the Unified Health System. Puerperal women that had their delivery covered by the Unified Health System reported a greater number of intercurrences related to infectious diseases, while women who used health plans and private sources reported intercurrences related to chronic diseases. A higher frequency of puerperal adolescents, non-white women, and women without partner among those assisted in the Unified Health System (p < 0.001). Conclusion: the high prevalence of complications indicates the need for monitoring and preventing diseases during pregnancy, especially in the case of pregnant women with unfavorable sociodemographic characteristics. PMID:29319740

Pregnancy complications in Brazilian puerperal women treated in the public and private health systems.

PubMed

Varela, Patrícia Louise Rodrigues; Oliveira, Rosana Rosseto de; Melo, Emiliana Cristina; Mathias, Thais Aidar de Freitas

2018-01-08

to analyze the prevalence of pregnancy complications and sociodemographic profile of puerperal patients with complications, according to the form of financing of the childbirth service. cross-sectional study with interview of 928 puerperal women whose childbirth was financed by the Unified Health System, health plans and private sources (other sources than the Unified Health System). The sample was calculated based on the births registered in the Information System on Live Births, stratified by hospital and form of financing of the childbirth service. Data were analyzed using the chi-square and Fisher's exact tests. the prevalence was 87.8% for all puerperal women, with an average of 2.4 complications per woman. In the case of deliveries covered by the Unified Health System, urinary tract infection (38.2%), anemia (26.0%) and leucorrhea (23.5%) were more frequent. In turn, vaginal bleeding (26.4%), urinary tract infection (23.9%) and leucorrhoea (23.7%) were prevalent in deliveries that were not covered by the Unified Health System. Puerperal women that had their delivery covered by the Unified Health System reported a greater number of intercurrences related to infectious diseases, while women who used health plans and private sources reported intercurrences related to chronic diseases. A higher frequency of puerperal adolescents, non-white women, and women without partner among those assisted in the Unified Health System (p < 0.001). the high prevalence of complications indicates the need for monitoring and preventing diseases during pregnancy, especially in the case of pregnant women with unfavorable sociodemographic characteristics.

Strategic Plan for Sustainable Energy Management and Environmental Stewardship for Los Angeles Unified School District

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walker, A.; Beattie, D.; Thomas, K.

2007-11-01

This Strategic Plan for Sustainable Energy Management and Environmental Stewardship states goals, measures progress toward goals and how actions are monitored to achieve continuous improvement for the Los Angeles Unified School District.

Harmful Algal Blooms Research

EPA Science Inventory

This project represents the Agency’s first effort to unify harmful algal blooms (HABs) research that had been previously carried out in isolation within various laboratories. A unified program is the most efficient way generate useful results for the Agency’s decision...

UPWP Unified Planning Work Program

DOT National Transportation Integrated Search

1995-05-01

The Unified Plannrng Work Program (UPWP) iS the planning document that guides the MPO staff in fulfilling its planning responstbilities for the upcoming year. Comprised of tasks that can be changed as the planning needs change. It is intended to serv...

MISR UAE Products

Atmospheric Science Data Center

2016-11-25

United Arab Emirates - Unified Aerosol Experiment (UAE 2 ) 2004 The United Arab Emirates-Unified Aerosol Experiment (UAE2) 2004 field campaign scheduled ... 2004 targets the coastal and desert regions of the United Arab Emirates. The main scientific goal is to evaluate and improve satellite ...

LDA-Based Unified Topic Modeling for Similar TV User Grouping and TV Program Recommendation.

PubMed

Pyo, Shinjee; Kim, Eunhui; Kim, Munchurl

2015-08-01

Social TV is a social media service via TV and social networks through which TV users exchange their experiences about TV programs that they are viewing. For social TV service, two technical aspects are envisioned: grouping of similar TV users to create social TV communities and recommending TV programs based on group and personal interests for personalizing TV. In this paper, we propose a unified topic model based on grouping of similar TV users and recommending TV programs as a social TV service. The proposed unified topic model employs two latent Dirichlet allocation (LDA) models. One is a topic model of TV users, and the other is a topic model of the description words for viewed TV programs. The two LDA models are then integrated via a topic proportion parameter for TV programs, which enforces the grouping of similar TV users and associated description words for watched TV programs at the same time in a unified topic modeling framework. The unified model identifies the semantic relation between TV user groups and TV program description word groups so that more meaningful TV program recommendations can be made. The unified topic model also overcomes an item ramp-up problem such that new TV programs can be reliably recommended to TV users. Furthermore, from the topic model of TV users, TV users with similar tastes can be grouped as topics, which can then be recommended as social TV communities. To verify our proposed method of unified topic-modeling-based TV user grouping and TV program recommendation for social TV services, in our experiments, we used real TV viewing history data and electronic program guide data from a seven-month period collected by a TV poll agency. The experimental results show that the proposed unified topic model yields an average 81.4% precision for 50 topics in TV program recommendation and its performance is an average of 6.5% higher than that of the topic model of TV users only. For TV user prediction with new TV programs, the average prediction precision was 79.6%. Also, we showed the superiority of our proposed model in terms of both topic modeling performance and recommendation performance compared to two related topic models such as polylingual topic model and bilingual topic model.

Stable TEM00-mode Nd:YAG solar laser operation by a twisted fused silica light-guide

NASA Astrophysics Data System (ADS)

Bouadjemine, R.; Liang, D.; Almeida, J.; Mehellou, S.; Vistas, C. R.; Kellou, A.; Guillot, E.

2017-12-01

To improve the output beam stability of a TEM00-mode solar-pumped laser, a twisted fused silica light-guide was used to achieve uniform pumping along a 3 mm diameter and 50 mm length Nd:YAG rod. The concentrated solar power at the focal spot of a primary parabolic mirror with 1.18 m2 effective collection area was efficiently coupled to the entrance aperture of a 2D-CPC/2V-shaped pump cavity, within which the thin laser rod was pumped. Optimum solar laser design parameters were found through ZEMAX© non-sequential ray-tracing and LASCAD© laser cavity analysis codes. 2.3 W continuous-wave TEM00-mode 1064 nm laser power was measured, corresponding to 1.96 W/m2 collection efficiency and 2.2 W laser beam brightness figure of merit. Excellent TEM00-mode laser beam profile at M2 ≤ 1.05 and very good output power stability of less than 1.6% were achieved. Heliostat orientation error dependent laser power variation was considerably less than previous solar laser pumping schemes.

Passive Q switching of a solar-pumped Nd:YAG laser.

PubMed

Lando, M; Shimony, Y; Noter, Y; Benmair, R M; Yogev, A

2000-04-20

Passive Q switching is a preferable choice for switching the Q factor of a solar-pumped laser because it requires neither a driver nor an electrical power supply. The superior thermal characteristics and durability of Cr(4+):YAG single crystals as passive Q switches for lamp and diode-pumped high-power lasers has been demonstrated. Here we report on an average power of 37 W and a switching efficiency of 80% obtained by use of a solar-pumped Nd:YAG laser Q switched by a Cr(4+):YAG saturable absorber. Concentration of the pumping solar energy on the laser crystal was obtained with a three-stage concentrator, composed of 12 heliostats, a three-dimensional compound parabolic concentrator (CPC) and a two-dimensional CPC. The water-cooled passive Q switch also served as the laser rear mirror. Repetition rates of as much as 50 kHz, at pulse durations between 190 and 310 ns (FWHM) were achieved. From the experimental results, the saturated single-pass power absorption of the Cr(4+):YAG device was estimated as 3 ? 1%.

Optical tools and techniques for aligning solar payloads with the SPARCS control system. [Solar Pointing Aerobee Rocket Control System

NASA Technical Reports Server (NTRS)

Thomas, N. L.; Chisel, D. M.

1976-01-01

The success of a rocket-borne experiment depends not only on the pointing of the attitude control system, but on the alignment of the attitude control system to the payload. To ensure proper alignment, special optical tools and alignment techniques are required. Those that were used in the SPARCS program are described and discussed herein. These tools include theodolites, autocollimators, a 38-cm diameter solar simulator, a high-performance 1-m heliostat to provide a stable solar source during the integration of the rocket payload, a portable 75-cm sun tracker for use at the launch site, and an innovation called the Solar Alignment Prism. Using the real sun as the primary reference under field conditions, the Solar Alignment Prism facilitates the coalignment of the attitude sun sensor with the payload. The alignment techniques were developed to ensure the precise alignment of the solar payloads to the SPARCS attitude sensors during payload integration and to verify the required alignment under field conditions just prior to launch.

Thermal resistance model for CSP central receivers

NASA Astrophysics Data System (ADS)

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.

PVMirrors: Hybrid PV/CSP collectors that enable lower LCOEs

NASA Astrophysics Data System (ADS)

Fisher, Kate; Yu, Zhengshan Jason; Striling, Rob; Holman, Zachary

2017-06-01

The primary challenge with concentrating solar power (CSP) is that the conversion efficiency is low—and the cost high—compared to that of photovoltaics (PV), and the primary challenge with PV is that the energy generated cannot be stored cost effectively. We introduce a technology that hybridizes CSP and PV, resulting in power plants with high energy conversion efficiency and affordable storage. This is accomplished by replacing silvered troughs (or heliostat facets) with "PVMirrors" that and direct photons of each wavelength to the converter (PV or thermal) that may best use them. A PVMirror looks like a curved PV module that includes a spectrum-splitting dichroic mirror film; this film, which is the heart of the technology, transmits near-infrared light to the underlying silicon PV cells while reflecting both longer and shorter wavelengths to a thermal absorber tube. This paper investigates the optical performance of dichroic mirror film, the specularity of PVMirrors, and the anticipated levelized cost of energy (LCOE) from a PVMirror power plant. PVMirrors are found to decrease LCOE by more than 15% relative to CSP while retaining full dispatchability.

A Unified Framework for Analyzing and Designing for Stationary Arterial Networks

DOT National Transportation Integrated Search

2017-05-17

This research aims to develop a unified theoretical and simulation framework for analyzing and designing signals for stationary arterial networks. Existing traffic flow models used in design and analysis of signal control strategies are either too si...

North Coast Unified Air Quality Management District: PSD Delegation Agreements

EPA Pesticide Factsheets

Agreements for Partial Delegation of the Federal Prevention of Significant Deterioration (PSD) Program Set Forth in 40 CPR 52.21 by the United States Environmental Protection Agency, Region 9 to the North Coast Unified Air Quality Management District.

On the reachable cycles via the unified perspective of cryocoolers. Part B: Cryocoolers with isentropic expanders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maytal, Ben-Zion; Pfotenhauer, John M.

2014-01-29

Solvay, Stirling and Gifford-McMahon types of cryocoolers employ an isentropic expander which is their elementary mechanism for temperature reduction (following the unified model of cryocoolers as described in a previous paper, Part A). Solvay and Stirling cryocoolers are driven by a larger temperature reduction than that of the Gifford-McMahon cycle, for a similar compression ratio. These cryocoolers are compared from the view of the unified model, in terms of the lowest attainable temperature, compression ratio, the size of the interchanger and the applied heat load.

Unified formalism for higher order non-autonomous dynamical systems

NASA Astrophysics Data System (ADS)

Prieto-Martínez, Pedro Daniel; Román-Roy, Narciso

2012-03-01

This work is devoted to giving a geometric framework for describing higher order non-autonomous mechanical systems. The starting point is to extend the Lagrangian-Hamiltonian unified formalism of Skinner and Rusk for these kinds of systems, generalizing previous developments for higher order autonomous mechanical systems and first-order non-autonomous mechanical systems. Then, we use this unified formulation to derive the standard Lagrangian and Hamiltonian formalisms, including the Legendre-Ostrogradsky map and the Euler-Lagrange and the Hamilton equations, both for regular and singular systems. As applications of our model, two examples of regular and singular physical systems are studied.

Creating a library holding group: an approach to large system integration.

PubMed

Huffman, Isaac R; Martin, Heather J; Delawska-Elliott, Basia

2016-10-01

Faced with resource constraints, many hospital libraries have considered joint operations. This case study describes how Providence Health & Services created a single group to provide library services. Using a holding group model, staff worked to unify more than 6,100 nonlibrary subscriptions and 14 internal library sites. Our library services grew by unifying 2,138 nonlibrary subscriptions and 11 library sites and hiring more library staff. We expanded access to 26,018 more patrons. A model with built-in flexibility allowed successful library expansion. Although challenges remain, this success points to a viable model of unified operations.

A unified construction for the algebro-geometric quasiperiodic solutions of the Lotka-Volterra and relativistic Lotka-Volterra hierarchy

NASA Astrophysics Data System (ADS)

Zhao, Peng; Fan, Engui

2015-04-01

In this paper, a new type of integrable differential-difference hierarchy, namely, the generalized relativistic Lotka-Volterra (GRLV) hierarchy, is introduced. This hierarchy is closely related to Lotka-Volterra lattice and relativistic Lotka-Volterra lattice, which allows us to provide a unified and effective way to obtain some exact solutions for both the Lotka-Volterra hierarchy and the relativistic Lotka-Volterra hierarchy. In particular, we shall construct algebro-geometric quasiperiodic solutions for the LV hierarchy and the RLV hierarchy in a unified manner on the basis of the finite gap integration theory.

Analysis of the prospective energy interconnections in Northeast Asia and development of the data portal

NASA Astrophysics Data System (ADS)

Churkin, Andrey; Bialek, Janusz

2018-01-01

Development of power interconnections in Northeast Asia becomes not only engineering but also a political issue. More research institutes are involved in the Asian Super Grid initiative discussion, as well as more politicians mention power interconnection opportunities. UNESCAP started providing a platform for intragovernmental discussion of the issue. However, there are still a lack of comprehensive modern research of the Asian Super Grid. Moreover, there is no unified data base and no unified power routes concept. Therefore, this article discusses a tool for optimal power routes selection and suggest a concept of the unified data portal.

Efficient construction of unified continuous and discontinuous Galerkin formulations for the 3D Euler equations

NASA Astrophysics Data System (ADS)

Abdi, Daniel S.; Giraldo, Francis X.

2016-09-01

A unified approach for the numerical solution of the 3D hyperbolic Euler equations using high order methods, namely continuous Galerkin (CG) and discontinuous Galerkin (DG) methods, is presented. First, we examine how classical CG that uses a global storage scheme can be constructed within the DG framework using constraint imposition techniques commonly used in the finite element literature. Then, we implement and test a simplified version in the Non-hydrostatic Unified Model of the Atmosphere (NUMA) for the case of explicit time integration and a diagonal mass matrix. Constructing CG within the DG framework allows CG to benefit from the desirable properties of DG such as, easier hp-refinement, better stability etc. Moreover, this representation allows for regional mixing of CG and DG depending on the flow regime in an area. The different flavors of CG and DG in the unified implementation are then tested for accuracy and performance using a suite of benchmark problems representative of cloud-resolving scale, meso-scale and global-scale atmospheric dynamics. The value of our unified approach is that we are able to show how to carry both CG and DG methods within the same code and also offer a simple recipe for modifying an existing CG code to DG and vice versa.

Improving the accuracy in detection of clustered microcalcifications with a context-sensitive classification model.

PubMed

Wang, Juan; Nishikawa, Robert M; Yang, Yongyi

2016-01-01

In computer-aided detection of microcalcifications (MCs), the detection accuracy is often compromised by frequent occurrence of false positives (FPs), which can be attributed to a number of factors, including imaging noise, inhomogeneity in tissue background, linear structures, and artifacts in mammograms. In this study, the authors investigated a unified classification approach for combating the adverse effects of these heterogeneous factors for accurate MC detection. To accommodate FPs caused by different factors in a mammogram image, the authors developed a classification model to which the input features were adapted according to the image context at a detection location. For this purpose, the input features were defined in two groups, of which one group was derived from the image intensity pattern in a local neighborhood of a detection location, and the other group was used to characterize how a MC is different from its structural background. Owing to the distinctive effect of linear structures in the detector response, the authors introduced a dummy variable into the unified classifier model, which allowed the input features to be adapted according to the image context at a detection location (i.e., presence or absence of linear structures). To suppress the effect of inhomogeneity in tissue background, the input features were extracted from different domains aimed for enhancing MCs in a mammogram image. To demonstrate the flexibility of the proposed approach, the authors implemented the unified classifier model by two widely used machine learning algorithms, namely, a support vector machine (SVM) classifier and an Adaboost classifier. In the experiment, the proposed approach was tested for two representative MC detectors in the literature [difference-of-Gaussians (DoG) detector and SVM detector]. The detection performance was assessed using free-response receiver operating characteristic (FROC) analysis on a set of 141 screen-film mammogram (SFM) images (66 cases) and a set of 188 full-field digital mammogram (FFDM) images (95 cases). The FROC analysis results show that the proposed unified classification approach can significantly improve the detection accuracy of two MC detectors on both SFM and FFDM images. Despite the difference in performance between the two detectors, the unified classifiers can reduce their FP rate to a similar level in the output of the two detectors. In particular, with true-positive rate at 85%, the FP rate on SFM images for the DoG detector was reduced from 1.16 to 0.33 clusters/image (unified SVM) and 0.36 clusters/image (unified Adaboost), respectively; similarly, for the SVM detector, the FP rate was reduced from 0.45 clusters/image to 0.30 clusters/image (unified SVM) and 0.25 clusters/image (unified Adaboost), respectively. Similar FP reduction results were also achieved on FFDM images for the two MC detectors. The proposed unified classification approach can be effective for discriminating MCs from FPs caused by different factors (such as MC-like noise patterns and linear structures) in MC detection. The framework is general and can be applicable for further improving the detection accuracy of existing MC detectors.

20 CFR 661.240 - How do the unified planning requirements apply to the five-year strategic WIA and Wagner-Peyser...

Code of Federal Regulations, 2010 CFR

2010-04-01

...) [Reserved] (6) Senior Community Service Employment Programs under title V of the Older Americans Act. (b... meeting the requirements of the Interagency guidance entitled State Unified Plan, Planning Guidance for...

Value Added

ERIC Educational Resources Information Center

Welch, Matt

2004-01-01

This article profiles retiring values teacher Gene Doxey and describes his foundational contributions to the students of California's Ramona Unified School District. Every one of the Ramona Unified School District's 7,200 students is eventually funneled through Doxey's Contemporary Issues class, a required rite of passage between elementary school…

A Unified Analysis of Japanese Aspect Marker "te iru."

ERIC Educational Resources Information Center

Shinzato, Rumiko

1993-01-01

Following Jacobson's 1990 work, this study is another attempt to offer a unified analysis of the Japanese aspect marker "te iru" that touches upon Gestalt psychologists' ideas of figure/ground opposition, Langacker's cognitive grammar, and Kunihiro's cognitive analysis. (Contains 34 references.) (LB)