WorldWideScience

Sample records for ranges microsecond on-board

  1. Shapes displayed with durations in the microsecond range do not obey Bloch's law of temporal summation.

    Science.gov (United States)

    Greene, Ernest; Ogden, R Todd

    2013-01-01

    Shape patterns were displayed with simultaneous brief flashes from a light-emitting diode array. Flash durations in the microsecond range and luminous intensities were adjusted to vary the degree of successful shape recognition. Four experiments were conducted to test whether Bloch's law would apply in this task. Bloch's law holds that for very brief flashes the perceptual threshold is determined by the total number of photons being delivered, i.e., there is reciprocity of intensity and duration. The present results did not find that effectiveness of flashes was based on the total quantity of photons, as predicted by Bloch's law. Additionally, the evidence points to a visual mechanism that has ultra-high temporal precision that either registers the rate of photon flux or the duration of flashes.

  2. Shapes Displayed with Durations in the Microsecond Range Do Not Obey Bloch's Law of Temporal Summation

    Directory of Open Access Journals (Sweden)

    Ernest Greene

    2013-09-01

    Full Text Available Shape patterns were displayed with simultaneous brief flashes from a light-emitting diode array. Flash durations in the microsecond range and luminous intensities were adjusted to vary the degree of successful shape recognition. Four experiments were conducted to test whether Bloch's law would apply in this task. Bloch's law holds that for very brief flashes the perceptual threshold is determined by the total number of photons being delivered, i.e., there is reciprocity of intensity and duration. The present results did not find that effectiveness of flashes was based on the total quantity of photons, as predicted by Bloch's law. Additionally, the evidence points to a visual mechanism that has ultra-high temporal precision that either registers the rate of photon flux or the duration of flashes.

  3. An all-solid-state microsecond-range quasi-square pulse generator based on fractional-turn ratio saturable pulse transformer and anti-resonance network.

    Science.gov (United States)

    Chen, Rong; Yang, Jianhua; Cheng, Xinbing; Pan, Zilong

    2017-03-01

    High voltage pulse generators are widely applied in a number of fields. Defense and industrial applications stimulated intense interests in the area of pulsed power technology towards the system with high power, high repetition rate, solid state characteristics, and compact structure. An all-solid-state microsecond-range quasi-square pulse generator based on a fractional-turn ratio saturable pulse transformer and anti-resonance network is proposed in this paper. This generator consists of a charging system, a step-up system, and a modulating system. In this generator, the fractional-turn ratio saturable pulse transformer is the key component since it acts as a step-up transformer and a main switch during the working process. Demonstrative experiments show that if the primary storage capacitors are charged to 400 V, a quasi-square pulse with amplitude of about 29 kV can be achieved on a 3500 Ω resistive load, as well as the pulse duration (full width at half maximum) of about 1.3 μs. Preliminary repetition rate experiments are also carried out, which indicate that this pulse generator could work stably with the repetition rates of 30 Hz and 50 Hz. It can be concluded that this kind of all-solid-state microsecond-range quasi-square pulse generator can not only lower both the operating voltage of the primary windings and the saturable inductance of the secondary windings, thus ideally realizing the magnetic switch function of the fractional-turn ratio saturable pulse transformer, but also achieve a quasi-square pulse with high quality and fixed flat top after the modulation of a two-section anti-resonance network. This generator can be applied in areas of large power microwave sources, sterilization, disinfection, and wastewater treatment.

  4. Design, Fabrication and Prototype testing of a Chip Integrated Micro PEM Fuel Cell Accumulator combined On-Board Range Extender

    Science.gov (United States)

    Balakrishnan, A.; Mueller, C.; Reinecke, H.

    2014-11-01

    In this work we present the design, fabrication and prototype testing of Chip Integrated Micro PEM Fuel Cell Accumulator (CIμ-PFCA) combined On-Board Range Extender (O-BRE). CIμ-PFCA is silicon based micro-PEM fuel cell system with an integrated hydrogen storage feature (palladium metal hydride), the run time of CIμ-PFCA is dependent on the stored hydrogen, and in order to extend its run time an O-BRE is realized (catalytic hydrolysis of chemical hydride, NaBH4. Combining the CIμ-PFCA and O-BRE on a system level have few important design requirements to be considered; hydrogen regulation, gas -liquid separator between the CIμ-PFCA and the O-RE. The usage of traditional techniques to regulate hydrogen (tubes), gas-liquid phase membranes (porous membrane separators) are less desirable in the micro domain, due to its space constraint. Our approach is to use a passive hydrogen regulation and gas-liquid phase separation concept; to use palladium membrane. Palladium regulates hydrogen by concentration diffusion, and its property to selectively adsorb only hydrogen is used as a passive gas-liquid phase separator. Proof of concept is shown by realizing a prototype system. The system is an assembly of CIμ-PFCA, palladium membrane and the O-BRE. The CIμ-PFCA consist of 2 individually processed silicon chips, copper supported palladium membrane realized by electroplating followed by high temperature annealing process under inter atmosphere and the O-BRE is realized out of a polymer substrate by micromilling process with platinum coated structures, which functions as a catalyst for the hydrolysis of NaBH4. The functionality of the assembled prototype system is demonstrated by the measuring a unit cell (area 1 mm2) when driven by the catalytic hydrolysis of chemical hydride (NaBH4 and the prototype system shows run time more than 15 hours.

  5. Research of a fractional-turn ratio saturable pulse transformer and its application in a microsecond-range pulse modulator

    Science.gov (United States)

    Chen, Rong; Yang, Jianhua; Cheng, Xinbing; Pan, Zilong

    2017-06-01

    As a combination device for a step-up pulse transformer and a magnetic switch, the saturable pulse transformer is widely used in pulsed-power and plasma technology. A fractional-turn ratio saturable pulse transformer is constructed and analyzed in this paper. Preliminary experimental results show that if the primary energy storage capacitors are charged to 300 V, an output voltage of about 19 kV can be obtained across the capacitor connected to the secondary windings of a fractional-turn ratio saturable pulse transformer. Theoretical and experimental results reveal that this kind of pulse transformer is not only able to integrate a step-up transformer and a magnetic switch into one device, but can also lower the saturable inductance of its secondary windings, thus leading to the relatively high step-up ratio of the pulse transformer. Meanwhile, the application of the fractional-turn ratio saturable pulse transformer in a μs range pulse modulator as a voltage step-up device and main switch is also included in this paper. The demonstrated experiments display that an output voltage with an amplitude of about 29 kV, and a 1.6 μs pulse width can be obtained across a 3500 Ω resistive load, based on a pulse modulator, if the primary energy storage capacitors are charged to 300 V. This compact fractional-turn ratio saturable pulse transformer can be applied in many other fields such as surface treatment, corona plasma generation and dielectric barrier discharge.

  6. On-Board State-of-Health Estimation at a Wide Ambient Temperature Range in Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Tiansi Wang

    2015-08-01

    Full Text Available A state-of-health (SOH estimation method for electric vehicles (EVs is presented with three main advantages: (1 it provides joint estimation of cell’s aging states in terms of power and energy (i.e., SOHP and SOHE—because the determination of SOHP and SOHE can be reduced to the estimation of the ohmic resistance increase and capacity loss, respectively, the ohmic resistance at nominal temperature will be taken as a health indicator, and the capacity loss is estimated based on a mechanistic model that is developed to describe the correlation between resistance increase and capacity loss; (2 it has wide applicability to various ambient temperatures—to eliminate the effects of temperature on the resistance, another mechanistic model about the resistance against temperature is presented, which can normalize the resistance at various temperatures to its standard value at the nominal temperature; and (3 it needs low computational efforts for on-board application—based on a linear equation of cell’s dynamic behaviors, the recursive least-squares (RLS algorithm is used for the resistance estimation. Based on the designed performance and validation experiments, respectively, the coefficients of the models are determined and the accuracy of the proposed method is verified. The results at different aging states and temperatures show good accuracy and reliability.

  7. A Novel Smart Pan/Tilt/Zoom Visible/Infrared Sensor for UAV On-Board Video Surveillance of Launch Range Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA has a pressing need for increasing the efficiency of launch range surveillance during mission launch operations. Difficulty in verifying a cleared range causes...

  8. From microseconds to seconds and minutes—time computation in insect hearing

    OpenAIRE

    Heiner eRömer; Manfred eHartbauer

    2014-01-01

    The computation of time in the auditory system of insects is of relevance at rather different time scales, covering a large range from microseconds to several minutes. At the one end of this range, only a few microseconds of interaural time differences are available for directional hearing, due to the minute distance between the ears, usually considered too small to be processed reliably by simple nervous systems. Synapses of interneurons in the afferent auditory pathway are, however, very se...

  9. SAS wave experiment on board Magion 4

    Directory of Open Access Journals (Sweden)

    J. Błęcki

    Full Text Available A short description of the SAS (subsatellite analyser of spectra wave experiment on board the Magion-4 subsatellite is given. We present first measurements of the magnetic-field fluctuations in the frequency range 32–2000 Hz obtained in the magnetotail during the disturbed period at the magnetopause and in the polar cusp.

  10. Developing Single-Molecule Technique with Microsecond Resolution

    Science.gov (United States)

    Akhterov, Maxim V.

    Molecular machines like proteins are responsible for many regulatory and catalytic functions. Specifically, molecular motions of proteins and their flexibility determine conformational states required for enzyme catalysis, signal transduction, and protein-protein interactions. However, the mechanisms for protein transitions between conformational states are often poorly understood, especially in the milli- to microsecond ranges where conventional optical techniques and computational modeling are most limited. This work describes development of an electronic single-molecule technique for monitoring microsecond motions of biological molecules. Dynamic changes of conductance through a transistor made of a single-walled carbon nanotube (SWNT-FET) report conformational changes of a protein molecule tethered to the SWNT sidewall. In principle, the high operating speed of SWNT-FETs could allow this technique to resolve molecular events with nanosecond resolution. This project focused on improving the technique to a 200 kHz effective bandwidth in order to resolve microsecond-scale dynamics. The improvement was achieved with a home-built electrochemical flow cell. By minimizing parasitic capacitance due to liquid coupling to electrodes and eliminating noise pickup, the flow cell enabled low-noise, high bandwidth measurement of molecular events as short as 2 mus. The apparatus was used to observe closing and opening motions of lysozyme. Preliminary results suggest that lysozyme has a distribution of possible velocities with the most probable speed approaching our experimental resolution of 2 mus.

  11. Sub-microsecond-resolution probe microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ginger, David; Giridharagopal, Rajiv; Moore, David; Rayermann, Glennis; Reid, Obadiah

    2014-04-01

    Methods and apparatus are provided herein for time-resolved analysis of the effect of a perturbation (e.g., a light or voltage pulse) on a sample. By operating in the time domain, the provided method enables sub-microsecond time-resolved measurement of transient, or time-varying, forces acting on a cantilever.

  12. On-board Diagnostics Framework

    OpenAIRE

    Olsson, Patrik

    2012-01-01

    For as long as complex machines have been around there has also been a need for accurate diagnostic and prognostic capabilities. Over the last decades there have been many attempts to develop and implement systems with various degrees of diagnostic and prognostic abilities, some successful some not. This master thesis presents a software architecture that is used to implement an on-board diagnostic framework capable of advanced diagnostics and prognostics in industrial vehicles. The presented...

  13. A Comparative Study on the Effects of Millisecond- and Microsecond-Pulsed Electric Field Treatments on the Permeabilization and Extraction of Pigments from Chlorella vulgaris.

    Science.gov (United States)

    Luengo, Elisa; Martínez, Juan Manuel; Coustets, Mathilde; Álvarez, Ignacio; Teissié, Justin; Rols, Marie-Pierre; Raso, Javier

    2015-10-01

    The interdependencies of the two main processing parameters affecting "electroporation" (electric field strength and pulse duration) while using pulse duration in the range of milliseconds and microseconds on the permeabilization, inactivation, and extraction of pigments from Chlorella vulgaris was compared. While irreversible "electroporation" was observed above 4 kV/cm in the millisecond range, electric field strengths of ≥10 kV/cm were required in the microseconds range. However, to cause the electroporation of most of the 90 % of the population of C. vulgaris in the millisecond (5 kV/cm, 20 pulses) or microsecond (15 kV/cm, 25 pulses) range, the specific energy that was delivered was lower for microsecond treatments (16.87 kJ/L) than in millisecond treatments (150 kJ/L). In terms of the specific energy required to cause microalgae inactivation, treatments in the microsecond range also resulted in greater energy efficiency. The comparison of extraction yields in the range of milliseconds (5 kV, 20 ms) and microseconds (20, 25 pulses) under the conditions in which the maximum extraction was observed revealed that the improvement in the carotenoid extraction was similar and chlorophyll a and b extraction was slightly higher for treatments in the microsecond range. The specific energy that was required for the treatment in the millisecond range (150 kJ/L) was much higher than those required in the microsecond range (30 kJ/L). The comparison of the efficacy of both types of pulses on the extraction enhancement just after the treatment and after a post-pulse incubation period seemed to indicate that PEF in the millisecond range created irreversible alterations while, in the microsecond range, the defects were a dynamic structure along the post-pulse time that caused a subsequent increment in the extraction yield.

  14. Ablation of steel by microsecond pulse trains

    Science.gov (United States)

    Windeler, Matthew Karl Ross

    Laser micromachining is an important material processing technique used in industry and medicine to produce parts with high precision. Control of the material removal process is imperative to obtain the desired part with minimal thermal damage to the surrounding material. Longer pulsed lasers, with pulse durations of milli- and microseconds, are used primarily for laser through-cutting and welding. In this work, a two-pulse sequence using microsecond pulse durations is demonstrated to achieve consistent material removal during percussion drilling when the delay between the pulses is properly defined. The light-matter interaction moves from a regime of surface morphology changes to melt and vapour ejection. Inline coherent imaging (ICI), a broadband, spatially-coherent imaging technique, is used to monitor the ablation process. The pulse parameter space is explored and the key regimes are determined. Material removal is observed when the pulse delay is on the order of the pulse duration. ICI is also used to directly observe the ablation process. Melt dynamics are characterized by monitoring surface changes during and after laser processing at several positions in and around the interaction region. Ablation is enhanced when the melt has time to flow back into the hole before the interaction with the second pulse begins. A phenomenological model is developed to understand the relationship between material removal and pulse delay. Based on melt refilling the interaction region, described by logistic growth, and heat loss, described by exponential decay, the model is fit to several datasets. The fit parameters reflect the pulse energies and durations used in the ablation experiments. For pulse durations of 50 us with pulse energies of 7.32 mJ +/- 0.09 mJ, the logisitic growth component of the model reaches half maximum after 8.3 mus +/- 1.1 us and the exponential decays with a rate of 64 mus +/- 15 us. The phenomenological model offers an interpretation of the material

  15. New On-board Microprocessors

    Science.gov (United States)

    Weigand, R.

    Two new processor devices have been developed for the use on board of spacecrafts. An 8-bit 8032-microcontroller targets typical controlling applications in instruments and sub-systems, or could be used as a main processor on small satellites, whereas the LEON 32-bit SPARC processor can be used for high performance controlling and data processing tasks. The ADV80S32 is fully compliant to the Intel 80x1 architecture and instruction set, extended by additional peripherals, 512 bytes on-chip RAM and a bootstrap PROM, which allows downloading the application software using the CCSDS PacketWire pro- tocol. The memory controller provides a de-multiplexed address/data bus, and allows to access up to 16 MB data and 8 MB program RAM. The peripherals have been de- signed for the specific needs of a spacecraft, such as serial interfaces compatible to RS232, PacketWire and TTC-B-01, counters/timers for extended duration and a CRC calculation unit accelerating the CCSDS TM/TC protocol. The 0.5 um Atmel manu- facturing technology (MG2RT) provides latch-up and total dose immunity; SEU fault immunity is implemented by using SEU hardened Flip-Flops and EDAC protection of internal and external memories. The maximum clock frequency of 20 MHz allows a processing power of 3 MIPS. Engineering samples are available. For SW develop- ment, various SW packages for the 8051 architecture are on the market. The LEON processor implements a 32-bit SPARC V8 architecture, including all the multiply and divide instructions, complemented by a floating-point unit (FPU). It includes several standard peripherals, such as timers/watchdog, interrupt controller, UARTs, parallel I/Os and a memory controller, allowing to use 8, 16 and 32 bit PROM, SRAM or memory mapped I/O. With on-chip separate instruction and data caches, almost one instruction per clock cycle can be reached in some applications. A 33-MHz 32-bit PCI master/target interface and a PCI arbiter allow operating the device in a plug-in card

  16. On-board Data Mining

    Science.gov (United States)

    Tanner, Steve; Stein, Cara; Graves, Sara J.

    Networks of remote sensors are becoming more common as technology improves and costs decline. In the past, a remote sensor was usually a device that collected data to be retrieved at a later time by some other mechanism. This collected data were usually processed well after the fact at a computer greatly removed from the in situ sensing location. This has begun to change as sensor technology, on-board processing, and network communication capabilities have increased and their prices have dropped. There has been an explosion in the number of sensors and sensing devices, not just around the world, but literally throughout the solar system. These sensors are not only becoming vastly more sophisticated, accurate, and detailed in the data they gather but they are also becoming cheaper, lighter, and smaller. At the same time, engineers have developed improved methods to embed computing systems, memory, storage, and communication capabilities into the platforms that host these sensors. Now, it is not unusual to see large networks of sensors working in cooperation with one another. Nor does it seem strange to see the autonomous operation of sensorbased systems, from space-based satellites to smart vacuum cleaners that keep our homes clean and robotic toys that help to entertain and educate our children. But access to sensor data and computing power is only part of the story. For all the power of these systems, there are still substantial limits to what they can accomplish. These include the well-known limits to current Artificial Intelligence capabilities and our limited ability to program the abstract concepts, goals, and improvisation needed for fully autonomous systems. But it also includes much more basic engineering problems such as lack of adequate power, communications bandwidth, and memory, as well as problems with the geolocation and real-time georeferencing required to integrate data from multiple sensors to be used together.

  17. Data Timing, Time Transfer and On-board Clock Monitoring for Space Astrometry with Gaia

    Science.gov (United States)

    Klioner, Sergei A.; Geyer, Robin; Steidelmüller, Hagen; Butkevich, Alexey G.

    2017-11-01

    The paper discusses the problematic of data timing in the framework of the space astrometry mission Gaia. For various reasons related both to astrometry and to the measuring principles of the Gaia instrument it is mandatory to assign a highly stable and accurate time tag for each observational point. For this purpose Gaia has a Rb clock on board. That on-board clock is a free-running oscillator and must be regularly synchronized with TCB which is used as the underlying relativistic coordinate time scale in the whole Gaia data processing. To monitor the reading of the on-board clock with respect to TCB (or any other timescale) a one-way clock synchronization scheme is implemented. This scheme takes into account all known theoretical effects (e.g., relativity, tropospheric delay, etc.) and allows one both to monitor the health of the on-board clock and to create a clock model at the accuracy of better than 1 microsecond.

  18. Data Timing, Time Transfer and On-board Clock Monitoring for Space Astrometry with Gaia

    Science.gov (United States)

    Klioner, Sergei A.; Geyer, Robin; Steidelmüller, Hagen; Butkevich, Alexey G.

    2017-10-01

    The paper discusses the problematic of data timing in the framework of the space astrometry mission Gaia. For various reasons related both to astrometry and to the measuring principles of the Gaia instrument it is mandatory to assign a highly stable and accurate time tag for each observational point. For this purpose Gaia has a Rb clock on board. That on-board clock is a free-running oscillator and must be regularly synchronized with TCB which is used as the underlying relativistic coordinate time scale in the whole Gaia data processing. To monitor the reading of the on-board clock with respect to TCB (or any other timescale) a one-way clock synchronization scheme is implemented. This scheme takes into account all known theoretical effects (e.g., relativity, tropospheric delay, etc.) and allows one both to monitor the health of the on-board clock and to create a clock model at the accuracy of better than 1 microsecond.

  19. New Rationales for Women on Boards

    OpenAIRE

    Choudhury, B.

    2014-01-01

    Should measures promoting women to corporate boards be solely justified in terms of economic arguments? Traditionally, such measures have tended to rely on utilitarian arguments, despite the fact that the most prominent of these arguments—the relationship between women’s presence on boards and firm financial performance—is equivocal. Conversely, this article argues that rationales for increasing women on boards should be based on both equality and economics grounds. An equality rationale is n...

  20. 10 microsecond time resolution studies of Cygnus X-1

    Energy Technology Data Exchange (ETDEWEB)

    Wen, H. C. [Stanford Univ., CA (United States)

    1997-06-01

    Time variability analyses have been applied to data composed of event times of X-rays emitted from the binary system Cygnus X-1 to search for unique black hole signatures. The X-ray data analyzed was collected at ten microsecond time resolution or better from two instruments, the High Energy Astrophysical Observatory (HEAO) A-1 detector and the Rossi X-ray Timing Explorer (XTE) Proportional Counter Array (PCA). HEAO A-1 and RXTE/PCA collected data from 1977--79 and from 1996 on with energy sensitivity from 1--25 keV and 2--60 keV, respectively. Variability characteristics predicted by various models of an accretion disk around a black hole have been searched for in the data. Drop-offs or quasi-periodic oscillations (QPOs) in the Fourier power spectra are expected from some of these models. The Fourier spectral technique was applied to the HEAO A-1 and RXTE/PCA data with careful consideration given for correcting the Poisson noise floor for instrumental effects. Evidence for a drop-off may be interpreted from the faster fall off in variability at frequencies greater than the observed breaks. Both breaks occur within the range of Keplerian frequencies associated with the inner edge radii of advection-dominated accretion disks predicted for Cyg X-1. The break between 10--20 Hz is also near the sharp rollover predicted by Nowak and Wagoner`s model of accretion disk turbulence. No QPOs were observed in the data for quality factors Q > 9 with a 95% confidence level upper limit for the fractional rms amplitude at 1.2% for a 16 M⊙ black hole.

  1. I/O Speculation for the Microsecond Era

    DEFF Research Database (Denmark)

    Wei, Michael Yung Chung; Bjørling, Matias; Bonnet, Philippe

    2014-01-01

    address the challenges that microsecond scale devices will bring. We measure applications for the potential benefit to be gained from speculation and examine several classes of speculation techniques. In addition, we propose two new techniques, hardware checkpoint and checkpoint-free speculation. Our...

  2. Gender Quotas on Board of Directors

    DEFF Research Database (Denmark)

    Smith, Nina

    2013-01-01

    Beside arguments of fairness and equal opportunities, it is often argued that gender diversity on boards of directors may improve firm performance, but the empirical results are mixed and often negative. Based on the available research, gender quotas on boards of directors cannot be justified...... on the grounds of economic efficiency. Furthermore, in most countries a limited number of women are qualified to join boards of directors, and it is not clear from the evidence to date on the operation of quotas whether they will lead to a better pool of female candidates in the medium and long term....

  3. Technical feasibility of an ROV with on-board power

    Energy Technology Data Exchange (ETDEWEB)

    Sayer, P.; Bo, L. [Univ. of Strathclyde, Glasgow (United Kingdom)

    1994-12-31

    An ROI`s electric power, control and communication signals are supplied from a surface ship or platform through an umbilical cable. Though cable design has evolved steadily, there are still severe limitations such as heavy weight and cost. It is well known that the drag imposed by the cable limits the operational range of the ROV in deep water. On the other hand, a cable-free AUV presents problems in control, communication and transmission of data. Therefore, an ROV with on-board and small-diameter cable could offer both a large operating range (footprint) and real-time control. This paper considers the feasibility of such an ROV with on-board power, namely a Self-Powered ROV (SPROV). The selection of possible power sources is first discussed before comparing the operational performance of an SPROV against a conventional ROV. It is demonstrated how an SPROV with a 5mm diameter tether offers a promising way forward, with on-board power of up to 40 kW over 24 hours. In water depths greater than 50m the reduced drag of the SPROV tether is very advantageous.

  4. Women on boards and firm performance

    NARCIS (Netherlands)

    M. Lückerath-Rovers (Mijntje)

    2013-01-01

    textabstractThis study investigates the financial performance of Dutch companies both with and without women on their boards. The analysis extends earlier methods used in research by Catalyst (The bottom line: corporate performance and women's representation on boards, 2007) and McKinsey (Women

  5. Another level of leadership: nurses on boards.

    Science.gov (United States)

    Bleich, Michael R

    2014-12-01

    The movement to place nurses on boards of directors is growing, enriching boards with individuals possessing knowledge of clinical quality tied to care delivery models, human resource competencies and management, finance, and organizational change. Professional development educators are poised to advance a board's capacity to address complex health care problems.

  6. Microsecond fiber laser pumped, single-frequency optical parametric oscillator for trace gas detection.

    Science.gov (United States)

    Barria, Jessica Barrientos; Roux, Sophie; Dherbecourt, Jean-Baptiste; Raybaut, Myriam; Melkonian, Jean-Michel; Godard, Antoine; Lefebvre, Michel

    2013-07-01

    We report on the first microsecond doubly resonant optical parametric oscillator (OPO). It is based on a nested cavity OPO architecture allowing single longitudinal mode operation and low oscillation threshold (few microjoule). The combination with a master oscillator-power amplifier fiber pump laser provides a versatile optical source widely tunable in the 3.3-3.5 μm range with an adjustable pulse repetition rate (from 40 to 100 kHz), high duty cycle (~10(-2)) and mean power (up to 25 mW in the idler beam). The potential for trace gas sensing applications is demonstrated through photoacoustic detection of atmospheric methane.

  7. Microsecond-resolved SDR-based cavity ring down ellipsometry.

    Science.gov (United States)

    Sofikitis, D; Spiliotis, A K; Stamataki, K; Katsoprinakis, G E; Bougas, L; Samartzis, P C; Loppinet, B; Rakitzis, T P; Surligas, M; Papadakis, S

    2015-06-20

    We present an experimental apparatus that allows microsecond-resolved ellipsometric and absorption measurements. The apparatus is based on an optical cavity containing a Dove prism, in which light undergoes total internal reflection (TIR), while the data acquisition is based on software defined radio technology and custom-built drivers. We demonstrate the ability to sense rapid variations in the refractive index above the TIR interface for arbitrarily long times with a temporal resolution of at least 2 μs.

  8. Wind shear measuring on board an airliner

    Science.gov (United States)

    Krauspe, P.

    1984-01-01

    A measurement technique which continuously determines the wind vector on board an airliner during takeoff and landing is introduced. Its implementation is intended to deliver sufficient statistical background concerning low frequency wind changes in the atmospheric boundary layer and extended knowledge about deterministic wind shear modeling. The wind measurement scheme is described and the adaptation of apparatus onboard an A300 airbus is shown. Preliminary measurements made during level flight demonstrate the validity of the method.

  9. BASKET on-board software library

    Science.gov (United States)

    Luntzer, Armin; Ottensamer, Roland; Kerschbaum, Franz

    2014-07-01

    The University of Vienna is a provider of on-board data processing software with focus on data compression, such as used on board the highly successful Herschel/PACS instrument, as well as in the small BRITE-Constellation fleet of cube-sats. Current contributions are made to CHEOPS, SAFARI and PLATO. The effort was taken to review the various functions developed for Herschel and provide a consolidated software library to facilitate the work for future missions. This library is a shopping basket of algorithms. Its contents are separated into four classes: auxiliary functions (e.g. circular buffers), preprocessing functions (e.g. for calibration), lossless data compression (arithmetic or Rice coding) and lossy reduction steps (ramp fitting etc.). The "BASKET" has all functionality that is needed to create an on-board data processing chain. All sources are written in C, supplemented by optimized versions in assembly, targeting popular CPU architectures for space applications. BASKET is open source and constantly growing

  10. Tuning Neuronal Hardware with Microsecond Precision: Sound Localization in the Barn Owl

    Science.gov (United States)

    van Hemmen, J. Leo

    1998-03-01

    In auditory and electrosensory neuronal systems, there seems to exist an unresolved paradox: They encode behaviorally relevant signals in the range of a few microseconds with neurons that are at least one order of magnitude slower. The barn owl's auditory system is a prominent example that may serve to provide a solution(W. Gerstner, R. Kempter, J.L. van Hemmen, and H. Wagner, Nature 383) (1996) 76--78 to the above paradox. First, neuronal output is much more accurate than the input, phprovided the presynaptic spikes arrive coherently on the average -- as they do in the adult animal. Second, this coherence in signal arrival times can be attained through unsupervised Hebbian learning (`tuning') during ontogenetic development. The learning rule governing the strength of a synapse is based on the precise timing of input as compared to output spikes. Third, the learning rule also selects the correct delays from two independent groups of input, for example, from the left and right ear and, thus, can explain the tuning to interaural time differences in the microsecond range that underlies sound localization. The relation to stochastic resonance is indicated.

  11. Development of a microsecond X-ray protein footprinting facility at the Advanced Light Source.

    Science.gov (United States)

    Gupta, Sayan; Celestre, Richard; Petzold, Christopher J; Chance, Mark R; Ralston, Corie

    2014-07-01

    X-ray footprinting (XF) is an important structural biology tool used to determine macromolecular conformations and dynamics of both nucleic acids and proteins in solution on a wide range of timescales. With the impending shut-down of the National Synchrotron Light Source, it is ever more important that this tool continues to be developed at other synchrotron facilities to accommodate XF users. Toward this end, a collaborative XF program has been initiated at the Advanced Light Source using the white-light bending-magnet beamlines 5.3.1 and 3.2.1. Accessibility of the microsecond time regime for protein footprinting is demonstrated at beamline 5.3.1 using the high flux density provided by a focusing mirror in combination with a micro-capillary flow cell. It is further reported that, by saturating samples with nitrous oxide, the radiolytic labeling efficiency is increased and the imprints of bound versus bulk water can be distinguished. These results both demonstrate the suitability of the Advanced Light Source as a second home for the XF experiment, and pave the way for obtaining high-quality structural data on complex protein samples and dynamics information on the microsecond timescale.

  12. Faraday rotation imaging microscope with microsecond pulse magnet

    Energy Technology Data Exchange (ETDEWEB)

    Suwa, Masayori, E-mail: msuwa@chem.sci.osaka-u.ac.jp [Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Tsukahara, Satoshi [Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Watarai, Hitoshi, E-mail: watarai@chem.sci.osaka-u.ac.jp [Institute for NanoScience Design, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)

    2015-11-01

    We have fabricated a high-performance Faraday rotation (FR) imaging microscope that uses a microsecond pulse magnet comprising an insulated gated bipolar transistor and a 2 μF capacitor. Our microscope produced images with greater stability and sensitivity than those of previous microscopes that used millisecond pulse magnet; these improvements are likely due to high repetition rate and negligible Joule heating effects. The mechanical vibrations in the magnet coil caused by the pulsed current were significantly reduced. The present FR microscope constructed an averaged image from 1000 FR images within 10 min under 1.7 T. Applications of the FR microscope to discriminating three benzene derivatives in micro-capillaries and oscillation-free imaging of spherical polystyrene and polymethyl methacrylate microparticles demonstrated its high performance. - Highlights: • A microsecond pulse magnet with high repetition rate of 10 Hz was fabricated. • Faraday rotation (FR) imaging microscope with the μs magnet was constructed. • Benzene derivatives in microcapillaries were distinguished with the FR microscope. • FR images of single polymer microspheres of 20 μm were correctly acquired. • Observed FR angles agreed quantitatively with those expected from Verdet constants.

  13. From microseconds to seconds and minutes-time computation in insect hearing.

    Science.gov (United States)

    Hartbauer, Manfred; Römer, Heiner

    2014-01-01

    The computation of time in the auditory system of insects is of relevance at rather different time scales, covering a large range from microseconds to several minutes. At the one end of this range, only a few microseconds of interaural time differences are available for directional hearing, due to the small distance between the ears, usually considered too small to be processed reliably by simple nervous systems. Synapses of interneurons in the afferent auditory pathway are, however, very sensitive to a time difference of only 1-2 ms provided by the latency shift of afferent activity with changing sound direction. At a much larger time scale of several tens of milliseconds to seconds, time processing is important in the context species recognition, but also for those insects where males produce acoustic signals within choruses, and the temporal relationship between song elements strongly deviates from a random distribution. In these situations, some species exhibit a more or less strict phase relationship of song elements, based on phase response properties of their song oscillator. Here we review evidence on how this may influence mate choice decisions. In the same dimension of some tens of milliseconds we find species of katydids with a duetting communication scheme, where one sex only performs phonotaxis to the other sex if the acoustic response falls within a very short time window after its own call. Such time windows show some features unique to insects, and although its neuronal implementation is unknown so far, the similarity with time processing for target range detection in bat echolocation will be discussed. Finally, the time scale being processed must be extended into the range of many minutes, since some acoustic insects produce singing bouts lasting quite long, and female preferences may be based on total signaling time.

  14. FROM MICROSECONDS TO SECONDS AND MINUTES - TIME COMPUTATION IN INSECT HEARING

    Directory of Open Access Journals (Sweden)

    Heiner eRömer

    2014-04-01

    Full Text Available The computation of time in the auditory system of insects is of relevance at rather different time scales, covering a large range from microseconds to several minutes. At the one end of this range, only a few microseconds of interaural time differences are available for directional hearing, due to the minute distance between the ears, usually considered too small to be processed reliably by simple nervous systems. Synapses of interneurons in the afferent auditory pathway are, however, very sensitive to a time difference of only 1-2ms provided by the latency shift of afferent activity with changing sound direction. At a much larger time scale of several tens of milliseconds to seconds, time processing is important in the context of species recognition, but also for those insects where males produce acoustic signals within choruses, and the temporal relationship between song elements strongly deviates from a random distribution. In these situations, some species exhibit a more or less strict phase relationship of song elements, based on phase response properties of their song oscillator. Here we review evidence on how this may influence mate choice decisions. In the same dimension of some tens of milliseconds we find species of katydids with a duetting communication scheme, where one sex only performs phonotaxis to the other sex if the acoustic response falls within a very short time window after its own call. Such time windows show some features unique to insects, and although its neuronal implementation is unknown so far, the similarity with time processing for target range detection in bat echolocation will be discussed. Finally, the time scale being processed must be extended into the range of many minutes, since some acoustic insects produce singing bouts lasting quite long, and female preferences may be based on total signalling time.

  15. In vitro study of the soft tissue effects of microsecond-pulsed CO(2) laser parameters during soft tissue incision and sulcular debridement.

    Science.gov (United States)

    Vaderhobli, Ram M; White, Joel M; Le, Christine; Ho, Sunita; Jordan, Richard

    2010-03-01

    Carbon dioxide (CO(2)) lasers are an important part of dental treatment. Advances in laser technology have produced microsecond pulse durations and small beam sizes. The histological effects of porcine intraoral soft tissue with a range of microsecond-pulsed CO(2) laser parameters used for incision and sulcular debridement were evaluated in vitro and compared with historical histologic data. Fresh pig mandibles were used to perform incision and sulcular debridement using a microsecond-pulsed CO(2) laser. lambda = 10,600 nm, articulated arm delivered non-contact with spot size 200 microm, 500 microm, and 1 mm, and focal distance of 1 mm. For sulcular debridement, epithelium within periodontal pocket (6 mm x 6 mm) was removed. Laser parameters for incision were from 30 Hz, 350 microseconds, 28 mJ and energy density of 143 J/cm(2) to 90 Hz, 1,000 microseconds, 60 mJ, and 1,911 J/cm(2). Width and depth of tissue removed, as well as coagulation effects of the tissue treated were measured. These were compared to historical histologic database. Laser-treated surfaces were observed qualitatively using scanning electron microscopy (SEM). All laser parameters studied were able to reach the defined simulation objectives in reasonable amounts of time, less than a minute for incision and <20 seconds for sulcular debridement. The depth of the cut was significantly greater than the historical 95% confidence interval, but equivalent for width, lateral, and deep coagulation to the historical database. Sulcular debridement was achieved with minimal coagulation, <100 microm. SEM analysis did not identify any alteration to enamel, dentin, or bone during sulcular debridement. The treatment objectives of incision and sulcular debridement were achieved with minimal lateral and deep coagulation in reasonable amount of time. Microsecond-pulsed CO(2) lasers can be safely and effectively used for incision and sulcular debridement.

  16. On-board processing for the COMPASS

    Science.gov (United States)

    Simi, Christopher G.; Winter, Edwin M.; Schlangen, Michael J.; Hill, Anthony B.

    2001-08-01

    The Compact Airborne Spectral Sensor (COMPASS) is a hyperspectral sensor covering the 400 to 2350 nm spectral region using a single focal plane and a very compact optical system. In addition, COMPASS will include a high-resolution panchromatic imager. With its compact design and its full spectral coverage throughout the visible, near infrared and SWIR, COMPASS represents a major step forward in the practical utilization of hyperspectral sensors for military operations. COMPASS will be deployed on a variety of airborne platforms for the detection of military objects of interest. There was considerable interest in the development of an on-board processor for COMPASS. The purpose of this processor is to calibrate the data and detect military targets in complex background clutter. Because of their ability to operate on truly hyperspectral data consisting of a hundred or more bands, linear unmixing algorithms were selected for the detection processor. The N-FINDR algorithm that automatically finds endmembers and then unmixes the scene was selected for real-time implementation. In addition, a recently developed detection algorithm, Stochastic Target Detection (STD), which was specifically designed for compatibility with linear unmixing algorithms, was chosen for the detection step. The N-FINDR/STD algorithm pair was first tested on a variety of hyperspectral data sets to determine its performance level relative to existing hyperspectral algorithms (such as RX) using Receiver Operator Curves (ROC) as the basis. Following completion of the testing, a hardware implementation of a real time processor for COMPASS using commercial off-the-shelf computer technology was designed. The COMPASS on-board processor will consist of the following elements: preprocessing, N-FINDR endmember determination and linear unmixing, the STD target detection step, and the selection of a High Resolution Image Chip covering the target area. Computer resource projections have shown that these

  17. Drug delivery with microsecond laser pulses into gelatin

    Science.gov (United States)

    Shangguan, Hanqun; Casperson, Lee W.; Shearin, Alan; Gregory, Kenton W.; Prahl, Scott A.

    1996-07-01

    Photoacoustic drug delivery is a technique for localized drug delivery by laser-induced hydrodynamic pressure following cavitation bubble expansion and collapse. Photoacoustic drug delivery was investigated on gelatin-based thrombus models with planar and cylindrical geometries by use of one microsecond laser pulses. Solutions of a hydrophobic dye in mineral oil permitted monitoring of delivered colored oil into clear gelatin-based thrombus models. Cavitation bubble development and photoacoustic drug delivery were visualized with flash photography. This study demonstrated that cavitation is the governing mechanism for photoacoustic drug delivery, and the deepest penetration of colored oil in gels followed the bubble collapse. Spatial distribution measurements revealed that colored oil could be driven a few millimeters into the gels in both axial and radial directions, and the penetration was less than 500 mu m when the gelatin structure was not fractured. localized drug delivery, cavitation bubble, laser thrombolysis.

  18. Substrate recognition by norovirus polymerase: microsecond molecular dynamics study

    Science.gov (United States)

    Maláč, Kamil; Barvík, Ivan

    2013-04-01

    Molecular dynamics simulations of complexes between Norwalk virus RNA dependent RNA polymerase and its natural CTP and 2dCTP (both containing the O5'-C5'-C4'-O4' sequence of atoms bridging the triphosphate and sugar moiety) or modified coCTP ( C5' -O5'-C4'-O4'), cocCTP ( C5' -O5'-C4'- C4'') substrates were produced by means of CUDA programmable graphical processing units and the ACEMD software package. It enabled us to gain microsecond MD trajectories clearly showing that similar nucleoside triphosphates can bind surprisingly differently into the active site of the Norwalk virus RNA dependent RNA polymerase. It corresponds to their different modes of action (CTP—substrate, 2dCTP—poor substrate, coCTP—chain terminator, cocCTP—inhibitor). Moreover, extremely rare events—as repetitive pervasion of Arg182 into a potentially reaction promoting arrangement—were captured.

  19. Microsecond time-scale kinetics of transient biochemical reactions.

    Directory of Open Access Journals (Sweden)

    Sandra Mitić

    Full Text Available To afford mechanistic studies in enzyme kinetics and protein folding in the microsecond time domain we have developed a continuous-flow microsecond time-scale mixing instrument with an unprecedented dead-time of 3.8 ± 0.3 μs. The instrument employs a micro-mixer with a mixing time of 2.7 μs integrated with a 30 mm long flow-cell of 109 μm optical path length constructed from two parallel sheets of silver foil; it produces ultraviolet-visible spectra that are linear in absorbance up to 3.5 with a spectral resolution of 0.4 nm. Each spectrum corresponds to a different reaction time determined by the distance from the mixer outlet, and by the fluid flow rate. The reaction progress is monitored in steps of 0.35 μs for a total duration of ~600 μs. As a proof of principle the instrument was used to study spontaneous protein refolding of pH-denatured cytochrome c. Three folding intermediates were determined: after a novel, extremely rapid initial phase with τ = 4.7 μs, presumably reflecting histidine re-binding to the iron, refolding proceeds with time constants of 83 μs and 345 μs to a coordinatively saturated low-spin iron form in quasi steady state. The time-resolution specifications of our spectrometer for the first time open up the general possibility for comparison of real data and molecular dynamics calculations of biomacromolecules on overlapping time scales.

  20. On-board processor orientated to low rate satellite services

    Science.gov (United States)

    Bella, Luigi; Fournon, Fernando; del Re, Enrico

    ESA has undertaken the development of the baseband laboratory prototype of an experimental on-board processing satellite system orientated to complement the TST/SS-TDMA prototype for a wide range of low rate services (e.g., vocoded voice, low rate circuit switched data, packet data). The current prototype investigates a few basic techniques (such as synchronization, multiservice switching) which are primarily intended for mobile systems and can be extended to further applications (e.g., enhanced VSAT's). The baseline up-link includes a flexible mixture of SCPC and very low rate TDMA and the downlink is TDM, so that compatibility with ground cellular networks could be achieved eventually. These techniques are going to be validated by a comprehensive test-bed set-up and can evolve into field experiments.

  1. Rationing and shock testing on-board equipment of spacecrafts

    Science.gov (United States)

    Orlov, S. A.; Matveev, K. A.; Rastorguev, G. I.

    2017-10-01

    The article addresses the issues of valuation and testing of on-board equipment for high-intensity shocks, discusses the problems of various shock testing facilities use and compares approaches to the problem in our country and abroad. The decision to use the specific mechanical test facilities for the on-board equipment testing is taken by its developer based on the assessment of on-board equipment resistance to the impact (resulting from own experience and numerical modeling).

  2. Evaluation of number concentration quantification by single-particle inductively coupled plasma mass spectrometry: microsecond vs. millisecond dwell times.

    Science.gov (United States)

    Abad-Álvaro, Isabel; Peña-Vázquez, Elena; Bolea, Eduardo; Bermejo-Barrera, Pilar; Castillo, Juan R; Laborda, Francisco

    2016-07-01

    The quality of the quantitative information in single-particle inductively coupled plasma mass spectrometry (SP-ICP-MS) depends directly on the number concentration of the nanoparticles in the sample analyzed, which is proportional to the flux of nanoparticles through the plasma. Particle number concentrations must be selected in accordance with the data acquisition frequency, to control the precision from counting statistics and the bias, which is produced by the occurrence of multiple-particle events recorded as single-particle events. With quadrupole mass spectrometers, the frequency of data acquisition is directly controlled by the dwell time. The effect of dwell times from milli- to microseconds (10 ms, 5 ms, 100 μs, and 50 μs) on the quality of the quantitative data has been studied. Working with dwell times in the millisecond range, precision figures about 5 % were achieved, whereas using microsecond dwell times, the suitable fluxes of nanoparticles are higher and precision was reduced down to 1 %; this was independent of the dwell time selected. Moreover, due to the lower occurrence of multiple-nanoparticle events, linear ranges are wider when dwell times equal to or shorter than 100 μs are used. A calculation tool is provided to determine the optimal concentration for any instrument or experimental conditions selected. On the other hand, the use of dwell times in the microsecond range reduces significantly the contribution of the background and/or the presence of dissolved species, in comparison with the use of millisecond dwell times. Although the use of dwell times equal to or shorter than 100 μs offers improved performance working in single-particle mode, the use of conventional dwell times (3-10 ms) should not be discarded, once their limitations are known.

  3. Bent-Pipe Vs On-Board Processing

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Bent-Pipe Vs On-Board Processing. “Bent-Pipe” refers to satellites. that do not process the transmitted signal but merely relay it from one ground station to another. The On-Board Processing allows. Multi-beam frequency re-use which increases satellite raw capacity; ...

  4. 47 CFR 90.423 - Operation on board aircraft.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Operation on board aircraft. 90.423 Section 90... PRIVATE LAND MOBILE RADIO SERVICES Operating Requirements § 90.423 Operation on board aircraft. (a) Except... after September 14, 1973, under this part may be operated aboard aircraft for air-to-mobile, air-to-base...

  5. Technology advancements for on-board propulsion systems

    Science.gov (United States)

    Byers, David

    1994-01-01

    On-board propulsion systems are required for all classes of space missions and usually represent a predominant fraction of the mass delivered to space by launch systems. Significant mission cost and performance benefits may, therefore, be gained via use of advanced on-board propulsion and strong international programs are in place to develop new technologies. The NASA Office of Space Access and Technology (OSAT) sponsors a program to identify, develop, and transfer on-board electric and low thrust chemical propulsion systems with potential for major impacts on the performance and competitiveness of U.S. space systems. The paper will briefly describe the overall content of the on-board propulsion program and then highlight some critical technologies with potentials for long term impacts.

  6. Legionella on board trains: effectiveness of environmental surveillance and decontamination

    National Research Council Canada - National Science Library

    Quaranta, Gianluigi; Vincenti, Sara; Ferriero, Anna Maria; Boninti, Federica; Sezzatini, Romina; Turnaturi, Cinzia; Gliubizzi, Maria Daniela; Munafò, Elio; Ceccarelli, Gianluca; Causarano, Carmelo; Accorsi, Massimo; Del Nord, Pasquale; Ricciardi, Walter; Laurenti, Patrizia

    2012-01-01

    .... Many studies describe the frequency and severity of Legionella spp. contamination in spa pools, natural pools, hotels and ships, but there is no study analysing the environmental monitoring of Legionella on board trains...

  7. Advanced On Board Inert Gas Generation System (OBBIGS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Valcor Engineering Corporation proposes to develop an advanced On Board Inert Gas Generation System, OBIGGS, for aircraft fuel tank inerting to prevent hazardous...

  8. On-board congestion control for satellite packet switching networks

    Science.gov (United States)

    Chu, Pong P.

    1991-01-01

    It is desirable to incorporate packet switching capability on-board for future communication satellites. Because of the statistical nature of packet communication, incoming traffic fluctuates and may cause congestion. Thus, it is necessary to incorporate a congestion control mechanism as part of the on-board processing to smooth and regulate the bursty traffic. Although there are extensive studies on congestion control for both baseband and broadband terrestrial networks, these schemes are not feasible for space based switching networks because of the unique characteristics of satellite link. Here, we propose a new congestion control method for on-board satellite packet switching. This scheme takes into consideration the long propagation delay in satellite link and takes advantage of the the satellite's broadcasting capability. It divides the control between the ground terminals and satellite, but distributes the primary responsibility to ground terminals and only requires minimal hardware resource on-board satellite.

  9. Understanding and Improving High Voltage Vacuum Insulators for Microsecond Pulses

    Energy Technology Data Exchange (ETDEWEB)

    Javedani, J B; Goerz, D A; Houck, T L; Lauer, E J; Speer, R D; Tully, L K; Vogtlin, G E; White, A D

    2007-03-05

    High voltage insulation is one of the main areas of pulsed power research and development, and dielectric breakdown is usually the limiting factor in attaining the highest possible performance in pulsed power devices. For many applications the delivery of pulsed power into a vacuum region is the most critical aspect of operation. The surface of an insulator exposed to vacuum can fail electrically at an applied field more than an order or magnitude below the bulk dielectric strength of the insulator. This mode of breakdown, called surface flashover, imposes serious limitations on the power flow into a vacuum region. This is especially troublesome for applications where high voltage conditioning of the insulator and electrodes is not practical and for applications where relatively long pulses, on the order of several microseconds, are required. The goal of this project is to establish a sound fundamental understanding of the mechanisms that lead to surface flashover, and then evaluate the most promising techniques to improve vacuum insulators and enable high voltage operation at stress levels near the intrinsic bulk breakdown limits of the material. The approach we proposed and followed was to develop this understanding through a combination of theoretical and computation methods coupled with experiments to validate and quantify expected behaviors. In this report we summarize our modeling and simulation efforts, theoretical studies, and experimental investigations. The computational work began by exploring the limits of commercially available codes and demonstrating methods to examine field enhancements and defect mechanisms at microscopic levels. Plasma simulations with particle codes used in conjunction with circuit models of the experimental apparatus enabled comparisons with experimental measurements. The large scale plasma (LSP) particle-in-cell (PIC) code was run on multiprocessor platforms and used to simulate expanding plasma conditions in vacuum gap regions

  10. Reactive Goal Decomposition Hierarchies for On-Board Autonomy

    Science.gov (United States)

    Hartmann, L.

    2002-01-01

    to state and environment and in general can terminate the execution of a decomposition and attempt a new decomposition at any level in the hierarchy. This goal decomposition system is suitable for workstation, microprocessor and fpga implementation and thus is able to support the full range of prototyping activities, from mission design in the laboratory to development of the fpga firmware for the flight system. This approach is based on previous artificial intelligence work including (1) Brooks' subsumption architecture for robot control, (2) Firby's Reactive Action Package System (RAPS) for mediating between high level automated planning and low level execution and (3) hierarchical task networks for automated planning. Reactive goal decomposition hierarchies can be used for a wide variety of on-board autonomy applications including automating low level operation sequences (such as scheduling prerequisite operations, e.g., heaters, warm-up periods, monitoring power constraints), coordinating multiple spacecraft as in formation flying and constellations, robot manipulator operations, rendez-vous, docking, servicing, assembly, on-orbit maintenance, planetary rover operations, solar system and interstellar probes, intelligent science data gathering and disaster early warning. Goal decomposition hierarchies can support high level fault tolerance. Given models of on-board resources and goals to accomplish, the decomposition hierarchy could allocate resources to goals taking into account existing faults and in real-time reallocating resources as new faults arise. Resources to be modeled include memory (e.g., ROM, FPGA configuration memory, processor memory, payload instrument memory), processors, on-board and interspacecraft network nodes and links, sensors, actuators (e.g., attitude determination and control, guidance and navigation) and payload instruments. A goal decomposition hierarchy could be defined to map mission goals and tasks to available on-board resources. As

  11. WFI electronics and on-board data processing

    Science.gov (United States)

    Plattner, Markus; Albrecht, Sebastian; Bayer, Jörg; Brandt, Soeren; Drumm, Paul; Hälker, Olaf; Kerschbaum, Franz; Koch, Anna; Kuvvetli, Irfan; Meidinger, Norbert; Ott, Sabine; Ottensamer, Roland; Reiffers, Jonas; Schanz, Thomas; Skup, Konrad; Steller, Manfred; Tenzer, Chris; Thomas, Chris

    2016-07-01

    The Wide Field Imager is one of two instruments on-board the future ATHENA X-ray observatory. Its main scientific objective is to perform a sky survey in the energy range of 0.2 keV up to 15 keV with an end-of-life spectral resolution (FWHM) better than 170 eV (at 7 keV) and a frame rate of at least 200 Hz. The field of view will be 40 arcmin squared wherefore a focal plane array with 4 large sensors each with a size of 512 times 512 pixels will be developed. Additionally, a fast detector with a size of 64 times 64 pixels and a frame rate of 12.5 kHz will be implemented in order to enhance the instrument with high count rate detection of bright sources. The data processing electronics within the WFI instrument is distributed over several subsystems: DEPFET sensors sensitive in the x-ray energy regime and front-end electronics are located inside the Camera Head. Data pre-processing inside the Detector Electronics will be performed in an FPGA-based frame-processor. FPGA external memory will be used to store offset and noise maps wherefore memory controllers have to be developed. Fast read and write access to the maps combined with robustness against radiation damage (e.g. bit-flips) has to be ensured by the frame-processor design.

  12. Microsecond light-induced proton transfer to flavin in the blue light sensor plant cryptochrome.

    Science.gov (United States)

    Langenbacher, Thomas; Immeln, Dominik; Dick, Bernhard; Kottke, Tilman

    2009-10-14

    Plant cryptochromes are blue light photoreceptors that regulate key responses in growth and daily rhythm of plants and might be involved in magnetoreception. They show structural homology to the DNA repair enzyme photolyase and bind flavin adenine dinucleotide as chromophore. Blue light absorption initiates the photoreduction from the oxidized dark state of flavin to the flavin neutral radical, which is the signaling state of the sensor. Previous time-resolved studies of the photoreduction process have been limited to observation of the decay of the radical in the millisecond time domain. We monitored faster, light-induced changes in absorption of an algal cryptochrome covering a spectral range of 375-750 nm with a streak camera setup. Electron transfer from tryptophan to flavin is completed before 100 ns under formation of the flavin anion radical. Proton transfer takes place with a time constant of 1.7 micros leading to the flavin neutral radical. Finally, the flavin radical and a tryptophan neutral radical decay with a time constant >200 micros in the millisecond and second time domain. The microsecond proton transfer has not been observed in animal cryptochromes from insects or photolyases. Furthermore, the strict separation in time of electron and proton transfer is novel in the field of flavin-containing photoreceptors. The reaction rate implies that the proton donor is not in hydrogen bonding distance to the flavin N5. Potential candidates for the proton donor and the involvement of the tryptophan triad are discussed.

  13. STROBE-X: X-ray Timing & Spectroscopy on Dynamical Timescales from Microseconds to Years

    Science.gov (United States)

    Ray, Paul; Wilson-Hodge, Colleen; Gendreau, Keith; Chakrabarty, Deepto; Feroci, Marco; Maccarone, Thomas; Arzoumanian, Zaven; Remillard, Ron; Wood, Kent; Griffith, Chris; Strobe-X Collaboration

    2017-01-01

    We describe a proposed probe-class mission concept that will provide an unprecedented view of the X-ray sky, performing timing and spectroscopy over a broad band (0.2-30 keV) probing timescale from microseconds to years. The Spectroscopic Time-Resolving Observatory for Broadband Energy X-rays (STROBE-X) comprises two primary instruments, one based on technology developed for the NICER mission and the other based on the European LOFT mission. The broad coverage will enable thermal components, non-thermal components, iron lines, and reflection features to be studied simultaneously from a single platform for the first time in accreting black holes at all scales. The massive collecting area will enable studies of the dense matter equation of state using multiple techniques. A broad range of other revolutionary science, such as high quality spectroscopy of clusters of galaxies and unprecedented timing investigations of active galactic nuclei, would also be obtained. We describe the mission concept and the planned trade studies that will optimize the mission to maximize the science return. This mission is being developed in collaboration with members of the European LOFT team, and a hardware contribution from Europe is expected.

  14. The XGS instrument on-board THESEUS

    Science.gov (United States)

    Fuschino, F.; Campana, R.; Labanti, C.; Marisaldi, M.; Amati, L.; Fiorini, M.; Uslenghi, M.; Baldazzi, G.; Evangelista, Y.; Elmi, I.; Feroci, M.; Frontera, F.; Rachevski, A.; Rignanese, L. P.; Vacchi, A.; Zampa, G.; Zampa, N.; Rashevskaya, I.; Bellutti, P.; Piemonte, C.

    2016-10-01

    Consolidated techniques used for space-borne X-ray and gamma-ray instruments are based on the use of scintillators coupled to Silicon photo-detectors. This technology associated with modern very low noise read-out electronics allows the design of innovative architectures able to reduce drastically the system complexity and power consumption, also with a moderate-to-high number of channels. These detector architectures can be exploited in the design of space instrumentation for gamma-spectroscopy with the benefit of possible smart background rejection strategies. We describe a detector prototype with 3D imaging capabilities to be employed in future gamma-ray and particle space missions in the 0.002-100 MeV energy range. The instrument is based on a stack of scintillating bars read out by Silicon Drift Detectors (SDDs) at both ends. The spatial segmentation and the crystal double-side readout allow a 3D position reconstruction with ∼3 mm accuracy within the full active volume, using a 2D readout along the two external faces of the detector. Furthermore, one of the side of SDDs can be used simultaneously to detect X-rays in the 2-30 keV energy range. The characteristics of this instrument make it suitable in next generation gamma-ray and particle space missions for Earth or outer space observations, and it will be briefly illustrated.

  15. Advanced Hybrid On-Board Science Data Processor - SpaceCube 2.0

    Science.gov (United States)

    Flatley, Tom

    2010-01-01

    Topics include an overview of On-board science data processing, software upset mitigation, on-board data reduction, on-board products, HyspIRI demonstration testbed, SpaceCube 2.0 block diagram, and processor comparison.

  16. APXS on board Chandrayaan-2 Rover

    Science.gov (United States)

    Shanmugam, M.; Sripada, V. S. Murty; Acharya, Y. B.; Goyal, S. K.

    2012-07-01

    Alpha Particle X-ray Spectrometer (APXS) is a well proven instrument for quantitative in situ elemental analysis of the planetary surfaces and has been successfully employed for Mars surface exploration. Chandrayaan-2, ISRO's second lunar mission having an Orbiter, Lander and Rover has provided an opportunity to explore the lunar surface with superior detectors such as Silicon Drift Detector (SDD) with energy resolution of about 150eV @ 5.9keV. The objective of the APXS instrument is to analyse several soil/rock samples along the rover traverse for the major elements with characteristic X-rays in 1 to 25keV range. The working principle of APXS involves measuring the intensity of characteristic X-rays emitted from the sample due to Alpha Particle Induced X-ray Emission (PIXE) and X-ray florescence (XRF) processes using suitable radioactive sources, allowing the determination of elements from Na to Br, spanning the energy range of 0.9 to 16keV. For this experiment ^{244}Cm radioactive source has been chosen which emits both Alpha particles (5.8MeV) and X-rays (14.1keV, 18keV). APXS uses six Alpha sources, each about 5mCi activity. Unlike Mars, lunar environment poses additional challenges due to the regolith and extreme surface temperature changes, to operate the APXS. Our APXS instrument consists of two packages namely APXS sensor head and APXS signal electronics. The sensor head assembly contains SDD, six alpha sources and front end electronic circuits such as preamplifier and shaper circuits and will be mounted on a robotic arm which on command brings the sensor head close to the lunar surface at a height of 35±10mm. SDD module to be used in the experiment has 30mm ^{2} active detector area with in-built peltier cooler and heat sink to maintain the detector at about -35°C. The detector is covered with 8 micron thick Be window which results in the low energy threshold of about 1keV. The size of the APXS sensor head is 70x70x70mm ^{3} (approx). APXS signal

  17. Detecting negative ions on board small satellites

    Science.gov (United States)

    Lepri, S. T.; Raines, J. M.; Gilbert, J. A.; Cutler, J.; Panning, M.; Zurbuchen, T. H.

    2017-04-01

    Recent measurements near comets, planets, and their satellites have shown that heavy ions, energetic neutral atoms, molecular ions, and charged dust contain a wealth of information about the origin, evolution, and interaction of celestial bodies with their space environment. Using highly sensitive plasma instruments, positively charged heavy ions have been used to trace exospheric and surface composition of comets, planets, and satellites as well as the composition of interplanetary and interstellar dust. While positive ions dominate throughout the heliosphere, negative ions are also produced from surface interactions. In fact, laboratory experiments have shown that oxygen released from rocky surfaces is mostly negatively charged. Negative ions and negatively charged nanograins have been detected with plasma electron analyzers in several different environments (e.g., by Cassini and Rosetta), though more extensive studies have been challenging without instrumentation dedicated to negative ions. We discuss an adaptation of the Fast Imaging Plasma Spectrometer (FIPS) flown on MErcury Surface, Space ENvironment, GEochemistry and Ranging (MESSENGER) for the measurement of negatively charged particles. MESSENGER/FIPS successfully measured the plasma environment of Mercury from 2011 until 2015, when the mission ended, and has been used to map multiple ion species (H+ through Na+ and beyond) throughout Mercury's space environment. Modifications to the existing instrument design fits within a 3U CubeSat volume and would provide a low mass, low power instrument, ideal for future CubeSat or distributed sensor missions seeking, for the first time, to characterize the contribution of negative particles in the heliospheric plasmas near the planets, moons, comets, and other sources.

  18. Position and orientation inference via on-board triangulation.

    Science.gov (United States)

    Advani, Madhu; Weile, Daniel S

    2017-01-01

    This work proposes a new approach to determine the spatial location and orientation of an object using measurements performed on the object itself. The on-board triangulation algorithm we outline could be implemented in lieu of, or in addition to, well-known alternatives such as Global Positioning System (GPS) or standard triangulation, since both of these correspond to significantly different geometric pictures and necessitate different hardware and algorithms. We motivate the theory by describing situations in which on-board triangulation would be useful and even preferable to standard methods. The on-board triangulation algorithm we outline involves utilizing dumb beacons which broadcast omnidirectional single frequency radio waves, and smart antenna arrays on the object itself to infer the direction of the beacon signals, which may be used for onboard calculation of the position and orientation of the object. Numerical examples demonstrate the utility of the method and its noise tolerance.

  19. Fatigue stress detection of VIRTIS cryocoolers on board Rosetta

    Science.gov (United States)

    Giuppi, Stefano; Politi, Romolo; Capria, Maria Teresa; Piccioni, Giuseppe; De Sanctis, Maria Cristina; Erard, Stéphane; Tosi, Federico; Capaccioni, Fabrizio; Filacchione, Gianrico

    Rosetta is a planetary cornerstone mission of the European Space Agency (ESA). It is devoted to the study of minor bodies of our solar system and it will be the first mission ever to land on a comet (the Jupiter-family comet 67P/Churyumov-Gerasimenko). VIRTIS-M is a sophisticated imaging spectrometer that combines two data channels in one compact instrument, respectively for the visible and the infrared range (0.25-5.0 μm). VIRTIS-H is devoted to infrared spectroscopy (2.5-5.0 μm) with high spectral resolution. Since the satellite will be inside the tail of the comet during one of the most important phases of the mission, it would not be appropriate to use a passive cooling system, due to the high flux of contaminants on the radiator. Therefore the IR sensors are cooled by two Stirling cycle cryocoolers produced by RICOR. Since RICOR operated life tests only on ground, it was decided to conduct an analysis on VIRTIS onboard Rosetta telemetries with the purpose of study possible differences in the cryocooler performancies. The analysis led to the conclusion that cryocoolers, when operating on board, are subject to a fatigue stress not present in the on ground life tests. The telemetries analysis shows a cyclic variation in cryocooler rotor angular velocity when -M or -H or both channel are operating (it has been also noted an influence of -M channel operations in -H cryocooler rotor angular velocity and vice versa) with frequencies mostly linked to operational parameters values. The frequencies have been calculated for each mission observation applying the Fast Fourier Transform (FFT). In order to evaluate possible hedge effects it has been also applied the Hanning window to compare the results. For a more complete evaluation of cryocoolers fatigue stress, for each mission observation the angular acceleration and the angular jerk have been calculated.

  20. On board electronic devices safety subject to high frequency electromagnetic radiation effects

    Science.gov (United States)

    Nikitin, V. F.; Smirnov, N. N.; Smirnova, M. N.; Tyurenkova, V. V.

    2017-06-01

    Spacecraft on board electronic devices are subjected to the effects of Space environment, in particular, electromagnetic radiation. The weight limitations for spacecraft pose an important material and structures problem: developing effective protection for on board electronic devices from high frequency electromagnetic radiation. In the present paper the problem of the effect of external high frequency electromagnetic field on electronic devices shielding located on orbital platforms is investigated theoretically. It is demonstrated that the characteristic time for the unsteady stage of the process is negligibly small as compared with characteristic time of electromagnetic field diffusion into a conductor for the studied range of governing parameters. A system of governing material parameters is distinguished, which contribute to protecting electronic devices from induced electrical currents.

  1. Thermal effects on 3D crater shape during IR laser ablation of monocrystalline silicon: From femtoseconds to microseconds

    Science.gov (United States)

    Buratin, Stefano; Bashtova, Kateryna; Kong, Ming Chu

    2017-07-01

    Analyzing the thermal effects (e.g., heat affected zone and debris analysis) on a laser-ablated crater using electron or atomic force microscopy is a time-consuming process while optical microscopy is limited to providing 2D information. The current work details an alternative method to identify and quantify the thermal effects based on an analysis of the 3D shape of craters. Starting from a thermal diffusion model, an iso-thermal function was developed and an iso-energetic function was defined based on the energy beam distribution. A systematic study of the 3D craters ablated on silicon was carried out at the four temporal regimes that are applicable in the industry: the femtosecond regime at 330 fs, the picosecond regime at 10 ps, the nanosecond regime in the range of 25-220 ns, and the microsecond regime in the range of 2-20 μs. It was shown that the defined Percentage Difference (PD) between the residual sum of squares (RSS) of the ellipsoid function and the RSS of the paraboloid function against the experimental crater, respectively, can be used to evaluate the presence of thermal effects. This corresponded with the results obtained using scanning electron microscope analysis. The analysis of the PD indicated how the crater shape was affected by the pulse duration while the non-thermal/thermal cutoff starting from the ps regime was studied. In addition, the crater shape was found to be affected by the laser beam fluence: for time regimes below the microsecond level, the thermal effects were seen to increase with higher laser beam fluence.

  2. 40 CFR 86.005-17 - On-board diagnostics.

    Science.gov (United States)

    2010-07-01

    ..., methanol, ethanol), beginning with the model year for which alternate fuel emission standards are... Petroleum Gas-Fueled and Methanol-Fueled Heavy-Duty Vehicles § 86.005-17 On-board diagnostics. (a) General...” contained in § 86.1380. (1) Catalysts and particulate traps. (i) Otto-cycle. Catalyst deterioration or...

  3. 40 CFR 86.1806-04 - On-board diagnostics.

    Science.gov (United States)

    2010-07-01

    ... Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks... 40 Protection of Environment 19 2010-07-01 2010-07-01 false On-board diagnostics. 86.1806-04 Section 86.1806-04 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

  4. Emergency medical kits on board commercial aircraft: a comparative study.

    Science.gov (United States)

    Sand, Michael; Gambichler, Thilo; Sand, Daniel; Thrandorf, Christina; Altmeyer, Peter; Bechara, Falk G

    2010-11-01

    In cases of critical medical situations on board commercial aircraft, access to emergency medical kits can be lifesaving. Thus, this comparative study investigated acute care medication and equipment supplied in emergency medical kits on board both low-cost carriers and full-service carriers. Thirty-two European airlines (sixteen low-cost carriers and sixteen full-service-carriers) were asked to provide anonymous data on the contents of their emergency medical kits. All emergency medical equipment and medication carried on board were subject to a descriptive analysis with regards to International Civil Aviation Organization (ICAO) standards for emergency medical kits, as well as variation and differences between low-cost carriers and full-service carriers. A total of twelve airlines (seven full-service carriers and five low-cost carriers) participated in this study. None complied with ICAO standards. Emergency medical kits from both full-service carriers and low-cost carriers exhibited a high degree of variability. Two European low-cost carriers were assessed as being insufficiently equipped for a medical emergency requiring acute care. This study demonstrates the high degree of variability in the contents of emergency medical kits. Additionally, some airlines were equipped insufficiently for a critical medical situation on board their aircraft. Frequent checks of national authorities and further evaluation of acute care equipment are required to prepare for potentially life-threatening critical conditions occurring in special environments, such as in airplane during flight. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. Architecture and design frame work for on board computer control ...

    African Journals Online (AJOL)

    Architecture and design frame work for on board computer control and data management of satellite systems. ECN Okafor, CE Okoro, JI Ejimanya. Abstract. No Abstract. International Journal of Natural and Applied Sciences Vol. 4 (3) 2008: pp. 139-145. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL ...

  6. Bijlagen visie on-board-monitoring in de binnenvaart

    NARCIS (Netherlands)

    Verbeek, R.P.; Harmsen, J.; Mensch, P. van

    2015-01-01

    In deze memo zijn de resultaten gepresenteerd van een analyse naar de impact van verschillende opties voor het vergroenen van de binnenvaart. In deze analyse zijn de volgende maatregelen opgenomen:  Vervroegd vervangen van de motor om in 2025 te voldoen aan CCRII;  Installeren van een On Board

  7. 40 CFR 85.2223 - On-board diagnostic test report.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false On-board diagnostic test report. 85... Tests § 85.2223 On-board diagnostic test report. (a) Motorists whose vehicles fail the on-board diagnostic test described in § 85.2222 shall be provided with the on-board diagnostic test results, including...

  8. Accurately modeling nanosecond protein dynamics requires at least microseconds of simulation.

    Science.gov (United States)

    Bowman, Gregory R

    2016-03-05

    Advances in hardware and algorithms have greatly extended the timescales accessible to molecular simulation. This article assesses whether such long timescale simulations improve our ability to calculate order parameters that describe conformational heterogeneity on ps-ns timescales or if force fields are now a limiting factor. Order parameters from experiment are compared with order parameters calculated in three different ways from simulations ranging from 10 ns to 100 μs in length. Importantly, bootstrapping is employed to assess the variability in results for each simulation length. The results of 10-100 ns timescale simulations are highly variable, possibly explaining the variation in levels of agreement between simulation and experiment in published works examining different proteins. Fortunately, microsecond timescale simulations improve both the accuracy and precision of calculated order parameters, at least so long as the full exponential fit or truncated average approximation is used instead of the common long-time limit approximation. The improved precision of these long timescale simulations allows a statistically sound comparison of a number of modern force fields, such as Amber03, Amber99sb-ILDN, and Charmm27. While there is some variation between these force fields, they generally give very similar results for sufficiently long simulations. The fact that so much simulation is required to precisely capture ps-ns timescale processes suggests that extremely extensive simulations are required for slower processes. Advanced sampling techniques could aid greatly, however, such methods will need to maintain accurate kinetics if they are to be of value for calculating dynamical properties like order parameters. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  9. Development of Quartz Friction Gauge on Board Balloon and Sounding Rocket

    Science.gov (United States)

    Kurihara, Junichi; Abe, Takumi; Murata, Isao; Sato, Kaoru; Tomikawa, Yoshihiro

    The on-board small vacuum gauge developed in this study is the quartz friction gauge, which is based on the principle that the resonance impedance of a quartz oscillator varies with the pressure of ambient gas. The gauge has a wide measuring range (105-10-2 Pa), which corresponds to the atmospheric pressure from the ground to an altitude of about 100 km. The sensor part and data processing part weigh 136 g and 210 g, respectively. In addition, the gauge can operate at a power consumption level of less than 1W. The gauge is suited for high altitude balloon experiments where the weight of on-board instruments must be kept to a minimum. The tuning-fork-shaped quartz oscillator in the gauge is widely used for wrist watches and has high resistance to vibration and shock, and thus the gauge is applicable to sounding rocket experiments that require on-board instruments with high resistance to the environment.

  10. Octafluoropropane Concentration Dynamics on Board the International Space Station

    Science.gov (United States)

    Perry, J. L.

    2003-01-01

    Since activating the International Space Station s (IS9 Service Module in November 2000, archival air quality samples have shown highly variable concentrations of octafluoropropane in the cabin. This variability has been directly linked to leakage from air conditioning systems on board the Service Module, Zvezda. While octafluoro- propane is not highly toxic, it presents a significant chal- lenge to the trace contaminant control systems. A discussion of octafluoropropane concentration dynamics is presented and the ability of on board trace contami- nant control systems to effectively remove octafluoropro- pane from the cabin atmosphere is assessed. Consideration is given to operational and logistics issues that may arise from octafluoropropane and other halo- carbon challenges to the contamination control systems as well as the potential for effecting cabin air quality.

  11. Development of on-board fuel metering and sensing system

    Science.gov (United States)

    Hemanth, Y.; Manikanta, B. S. S.; Thangaraja, J.; Bharanidaran, R.

    2017-11-01

    Usage of biodiesel fuels and their blends with diesel fuel has a potential to reduce the tailpipe emissions and reduce the dependence on crude oil imports. Further, biodiesel fuels exhibit favourable greenhouse gas emission and energy balance characteristics. While fossil fuel technology is well established, the technological implications of biofuels particularly biodiesel is not clearly laid out. Hence, the objective is to provide an on-board metering control in selecting the different proportions of diesel and bio-diesel blends. An on-board fuel metering system is being developed using PID controller, stepper motors and a capacitance sensor. The accuracy was tested with the blends of propanol-1, diesel and are found to be within 1.3% error. The developed unit was tested in a twin cylinder diesel engine with biodiesel blended diesel fuel. There was a marginal increase (5%) in nitric oxide and 14% increase in smoke emission with 10% biodiesel blended diesel at part load conditions.

  12. Why so few Women on Boards of Directors?

    DEFF Research Database (Denmark)

    Smith, Nina; Parrotta, Pierpaolo

    2015-01-01

    This paper analyzes the determinants of women’s representation on boards of directors based on a panel of all privately owned or listed Danish firms with at least 50 employees observed during the period 1998–2010. We focus on the directors who are not elected by the employees and test three hypot...... suggests that an important way to increase the female proportion of non-employee-elected board members is that more women reach top executive positions....

  13. Test case generation for On Board Computer Software Major Components

    OpenAIRE

    Dinesha H A; V.K Agrawal

    2013-01-01

    PES Institute of Technology along with five other institutions is developing a student imaging satellite. In imaging satellite development, software implementation plays an important role. On Board Computer (OBC) is one which runs the satellite software. Satellite software has its sub components like telemetry, control modes, data processing, actuator, tele command and etc. Design, development and testing of these components are done successfully. Testing plays very important role to assure i...

  14. ON BOARD OF SHIPS THERMAL ENERGY RECOVERY CONDITIONS

    Directory of Open Access Journals (Sweden)

    Beazit ALI

    2016-12-01

    Full Text Available In the paper are presented at first the energy recovery conditions used at the moment on board of ships and the restrictions which do not allow the achievement of higher recovery ratios. The authors suggest a new type of recovery plant by vaporization of water by means of expansion and they show its advantages in the considerably increase of energy recovery ratio from burnt gases from the cooling water of marine engine

  15. Homogeneous Nucleation of Methane Hydrate in Microsecond Molecular Dynamics Simulations.

    Science.gov (United States)

    Sarupria, Sapna; Debenedetti, Pablo G

    2012-10-18

    We report atomistically detailed molecular dynamics simulations of homogeneous nucleation of methane hydrate in bulk aqueous phase in the absence of any interface. Subcritical clusters of water and methane molecules are formed in the initial segment of the simulations, which then aggregate to give the critical hydrate nucleus. This occurs over time scales of several hundred nanoseconds, indicating that the formation and aggregation of subcritical clusters can contribute significantly to the overall rate of hydrate nucleation. The clusters have elements of sI hydrate structure, such as 5(12) and 5(12)6(2) cages as well as other uncommon 5(12)6(3) and 5(12)6(4) cages, but do not possess long-range order. Clusters are dynamic in nature and undergo continuous structural rearrangements.

  16. High-current relativistic klystron amplifier development for microsecond pulse lengths

    Science.gov (United States)

    Fazio, M. V.; Carlsten, B. E.; Faehl, R. J.; Kwan, T. J.; Rickel, D. G.; Stringfield, R. M.; Tallerico, P. J.

    1991-05-01

    Los Alamos is extending the performance of the Friedman-type, high-current relativistic klystron amplifier (RKA) to the microsecond regime while attempting to achieve the gigawatt-level peak power capability that has been characteristic of the RKA at shorter pulse lengths. Currently the electron beam power into the device is about 1 GW in microsecond duration pulses, with an effort underway to increase the beam power to 2.5 GW. To date the device has yielded an RF modulated electron beam power of 350 MW, with up to 50 MW coupled into the waveguide. Several aspects of RKA operation under investigation that affect RKA beam bunching efficiency and amplifier gain include cavity tuning, beam diameter, beam current, and input RF drive power, and the development of an output coupler that efficiently couples the microwave power from the low impedance beam into rectangular waveguide operating in the dominant mode. Current results from experimental testing and code modelling are presented.

  17. High efficiency laser-assisted H- charge exchange for microsecond duration beams

    Science.gov (United States)

    Cousineau, Sarah; Rakhman, Abdurahim; Kay, Martin; Aleksandrov, Alexander; Danilov, Viatcheslav; Gorlov, Timofey; Liu, Yun; Long, Cary; Menshov, Alexander; Plum, Michael; Shishlo, Andrei; Webster, Andrew; Johnson, David

    2017-12-01

    Laser-assisted stripping is a novel approach to H- charge exchange that overcomes long-standing limitations associated with the traditional, foil-based method of producing high-intensity, time-structured beams of protons. This paper reports on the first successful demonstration of the laser stripping technique for microsecond duration beams. The experiment represents a factor of 1000 increase in the stripped pulse duration compared with the previous proof-of-principle demonstration. The central theme of the experiment is the implementation of methods to reduce the required average laser power such that high efficiency stripping can be accomplished for microsecond duration beams using conventional laser technology. The experiment was performed on the Spallation Neutron Source 1 GeV H- beam using a 1 MW peak power UV laser and resulted in ˜95 % stripping efficiency.

  18. Microsecond Time-Resolved Circular Dichroism of Rhodopsin Photointermediates†

    Science.gov (United States)

    Thomas, Yiren Gu; Szundi, Istvan; Lewis, James W.; Kliger, David S.

    2009-01-01

    Time-resolved circular dichroism measurements, over a spectral range from 300 to 700 nm, were made at delays of 5, 100 and 500 μs after room temperature photoexcitation of bovine rhodopsin in lauryl maltoside suspension. The purpose was to provide more structural information about intermediate states in the activation of rhodopsin and other G protein-coupled receptors. In particular, information was sought about photointermediates that are isochromic or nearly isochromic in their unpolarized absorbance. The circular dichroism spectrum of lumirhodopsin, obtained after correcting the 5 μs difference CD data for the rhodopsin bleached, was in reasonable agreement with the lumirhodopsin CD spectrum obtained previously by thermal trapping at -76°C. Similarly, the metarhodopsin II spectrum obtained at 500 μs delay was also in agreement with the results of previous work on the temperature trapped form of metarhodopsin II. However, the CD of the mixture formed at 100 μs delay after photoexcitation, whose only visible absorbing component is lumirhodopsin, could not be accounted for near 480 nm in terms of the initially formed, 5 μs lumirhodopsin CD spectrum. Thus, the CD spectrum of lumirhodopsin changes on the time scale from 5 to 100 μs, showing reduced rotational strength in its visible band, possibly associated with either a process responsible for a small spectral shift that occurs in the lumirhodopsin absorbance spectrum at earlier times or the Schiff base deprotonation-reprotonation which occurs during equilibration of lumirhodopsin with the Meta I380 photointermediate. Either explanation suggests a chromophore conformation change closely associated with deprotonation which could be the earliest direct trigger of activation. PMID:19905009

  19. DORIS/Jason-2: Better than 10 cm on-board orbits available for Near-Real-Time Altimetry

    Science.gov (United States)

    Jayles, C.; Chauveau, J. P.; Rozo, F.

    2010-12-01

    DIODE (DORIS Immediate Orbit on-board Determination) is a real-time on-board orbit determination software, embedded in the DORIS receiver. The purpose of this paper is to focus on DIODE performances. After a description of the recent DORIS evolutions, we detail how compliance with specifications are verified during extensive ground tests before the launch, then during the in-flight commissioning phase just after the launch, and how well they are met in the routine phase and today. Future improvements are also discussed for Jason-2 as well as for the next missions. The complete DORIS ground validation using DORIS simulator and new DORIS test equipments has shown prior to the Jason-2 flight that every functional requirement was fulfilled, and also that better than 10 cm real-time DIODE orbits would be achieved on-board Jason-2. The first year of Jason-2 confirmed this, and after correction of a slowly evolving polar motion error at the end of the commissioning phase, the DIODE on-board orbits are indeed better than the 10 cm specification: in the beginning of the routine phase, the discrepancy was already 7.7 cm Root-Mean-Square (RMS) in the radial component as compared to the final Precise Orbit Ephemerides (POE) orbit. Since the first day of Jason-2 cycle 1, the real-time DIODE orbits have been delivered in the altimetry fast delivery products. Their accuracy and their 100% availability make them a key input to fairly precise Near-Real-Time Altimetry processing. Time-tagging is at the microsecond level. In parallel, a few corrections (quaternion problem) and improvements have been gathered in an enhanced version of DIODE, which is already implemented and validated. With this new version, a 5 cm radial accuracy is achieved during ground validation over more than Jason-2 first year (cycles 1-43, from July 12th, 2008 to September 11th, 2009). The Seattle Ocean Surface Topography Science Team Meeting (OSTST) has recommended an upload of this v4.02 version on-board

  20. Drills and Training on board Ship in Maritime Transport

    Directory of Open Access Journals (Sweden)

    Cristina Dragomir

    2016-01-01

    Full Text Available In maritime transport, drills are methods of practicing how a team or individuals should behavein case of an emergency on board ship (fire, explosion, pirates’ attacks, ship sinking, shipgrounding, capsizing etc.. Most commonly acknowledged in the shipping domain, drills aresynonyms to training exercises. Drills are extremely important for the safety of ship, crew andpassengers and are mandatory to be performed in any sea voyage. In this paper is made anoverview on regulatory framework and strategic role of efficient maritime drills and training.

  1. On-board processing of video image sequences

    DEFF Research Database (Denmark)

    Andersen, Jakob Dahl; Chanrion, Olivier Arnaud; Forchhammer, Søren

    2008-01-01

    The ldquoatmosphere-space interactions monitorrdquo (ASIM) is a payload to be mounted on one of the external platforms of the Columbus module of the International Space Station (ISS). The instruments include six video cameras, six photometers and one X-ray detector. The main scientific objective...... of the mission is to study transient luminous events (TLE) above severe thunderstorms: the sprites, jets and elves. Other atmospheric phenomena are also studied including aurora, gravity waves and meteors. As part of the ASIM Phase B study, on-board processing of data from the cameras is being developed...

  2. 40 CFR 85.2231 - On-board diagnostic test equipment requirements.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false On-board diagnostic test equipment... Warranty Short Tests § 85.2231 On-board diagnostic test equipment requirements. (a) The test system... be capable of checking for the monitors supported by the on-board diagnostic system and the...

  3. 40 CFR 85.2207 - On-board diagnostics test standards.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false On-board diagnostics test standards... Warranty Short Tests § 85.2207 On-board diagnostics test standards. (a) (b) A vehicle shall fail the on-board diagnostics test if it is a 1996 or newer vehicle and the vehicle connector is missing, has been...

  4. 40 CFR 85.2222 - On-board diagnostic test procedures.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false On-board diagnostic test procedures... Warranty Short Tests § 85.2222 On-board diagnostic test procedures. The test sequence for the inspection of on-board diagnostic systems on 1996 and newer light-duty vehicles and light-duty trucks shall consist...

  5. Liquefaction Incidents of Mineral Cargoes on Board Bulk Carriers

    Directory of Open Access Journals (Sweden)

    Michael C. Munro

    2016-01-01

    Full Text Available Liquefaction is a frequently occurring problem taking place when transporting wet granular solid bulk cargoes on board bulk carriers. Liquefaction of a solid bulk cargo can occur when excessive dynamic loading, induced by rough seas and vessel vibrations, is transmitted to the cargo. From 1988 to 2015, there have been 24 suspected liquefaction incidents reported, which resulted in 164 casualties and the loss of 18 vessels. The objective of this study is to investigate the collective causes of liquefaction of solid bulk cargoes on board bulk carriers in order to make recommendations to prevent future incidents from occurring. This was achieved by analysing the seven available investigative reports relating to the incidents, focusing on the key findings and exploring the effect of excess moisture within the cargo. This study has placed significant emphasis on the importance of preventing ingress of water into the cargo during transportation, loading, and storage. Recommendations have been given, based on the key findings from the reports, to reduce the potential for liquefaction incidents to occur.

  6. Assessing exposure to cosmic radiation on board aircraft

    Science.gov (United States)

    Bottollier-Depois, J. F.; Chau, Q.; Bouisset, P.; Kerlau, G.; Plawinski, L.; Lebaron-Jacobs, L.

    The assessment of exposure to cosmic radiation on board aircraft is one of the preoccupations of organizations responsible for radiation protection. The cosmic radiation particle flux increases with altitude and latitude and depends on the solar activity. The radiation exposure has been estimated on several airlines using transatlantic, Siberian and transequatorial routes on board subsonic and supersonic aircraft, to illustrate the effect of these parameters: Measurements have been obtained with a tissue equivalent proportional counter using the microdosimetric technique. Data have been collected at maximum solar activity in 1991-1992 and at minimum in 1996-1998. The lowest mean dose rate measured was 3 μSv/h during a Paris-Buenos Aires flight in 1991; the highest was 6.6 μSv/h during a Paris-Tokyo flight using a Siberian route and 9.7 μ Sv/h on Concorde in 1996-1997. The mean quality factor is around 1.8. The corresponding annual effective dose, based on 700 hours of flight for subsonic aircraft and 300 hours for Concorde, can be-estimated between 2 rnSv for least-exposed routes and 5 mSv for more exposed routes.

  7. On-board aircrew dosimetry using a semiconductor spectrometer

    CERN Document Server

    Spurny, F

    2002-01-01

    Radiation fields on board aircraft contain particles with energies up to a few hundred MeV. Many instruments have been tested to characterise these fields. This paper presents the results of studies on the use of an Si diode spectrometer to characterise these fields. The spectrometer has been in use since spring 2000 on more than 130 return flights to monitor and characterise the on-board field. During a Czech Airlines flight from Prague to New York it was possible to register the effects of an intense solar flare, (ground level event, GLE 60), which occurred on 15 April 2001. It was found that the number of deposition events registered was increased by about 70% and the dose in Si by a factor of 2.0 when compared with the presence of galactic cosmic rays alone. Directly measured data are interpreted with respect to on-earth reference field calibration (photons, CERN high-energy particles); it was found that this approach leads to encouraging results and should be followed up. (7 refs).

  8. Effective "on-boarding": transitioning from trainee to faculty.

    Science.gov (United States)

    Gustin, Jillian; Tulsky, James A

    2010-10-01

    Abstract The transition from trainee to junior faculty member can be both exciting and daunting. However, a paucity of medical literature exists to help guide new faculty in this transition. Therefore, we adapted work from the business management literature on what is referred to as "on-boarding"; effectively integrating and advancing one's position as a new employee. This article outlines strategies for cultivating one's own on-boarding as a junior faculty member at large academic medical centers. These strategies are extrapolated from management practices, culled from the medical literature on developing and retaining junior faculty, and, finally, borrowed from the hard-won knowledge of junior and senior faculty members. They advise new faculty to: (1) start early, (2) define your role--"managing yourself," (3) invest in/secure early wins, (4) manage your manager, (5) identify the "true (or hidden)" organizational culture, (6) reassess your own goals--"look in the rearview mirror and to the horizon," and (7) use your mentors effectively. These strategies provide a roadmap for new faculty members to transition as effectively as possible to their new jobs.

  9. The SXI telescope on board EXIST: scientific performances

    Science.gov (United States)

    Natalucci, L.; Bazzano, A.; Campana, S.; Caraveo, P.; Della Ceca, R.; Grindlay, J. E.; Panessa, F.; Pareschi, G.; Ramsey, B.; Tagliaferri, G.; Ubertini, P.; Villa, G.

    2009-08-01

    The SXI telescope is one of the three instruments on board EXIST, a multiwavelenght observatory in charge of performing a global survey of the sky in hard X-rays searching for Supermassive Black Holes. One of the primary objectives of EXIST is also to study with unprecedented sensitivity the most unknown high energy sources in the Universe, like high redshift GRBs, which will be pointed promptly by the Spacecraft by autonomous trigger based on hard X-ray localization on board. The recent addition of a soft X-ray telescope to the EXIST payload complement, with an effective area of 950 cm2 in the energy band 0.2-3 keV and extended response up to 10 keV will allow to make broadband studies from 0.1 to 600 keV. In particular, investigations of the spectra components and states of AGNs and monitoring of variability of sources, study of the prompt and afterglow emission of GRBs since the early phases, which will help to constrain the emission models and finally, help the identification of sources in the EXIST hard X-ray survey and the characterization of the transient events detected. SXI will also perform surveys: a scanning survey with sky coverage ~ 2 π and limiting flux of ~ 5 × 10-14 cgs plus other serendipitous. We give an overview of the SXI scientific performance and also describe the status of its design emphasizing how it has been derived by the scientific requirements.

  10. Reconfigurable On-Board Vision Processing for Small Autonomous Vehicles

    Directory of Open Access Journals (Sweden)

    James K. Archibald

    2006-12-01

    Full Text Available This paper addresses the challenge of supporting real-time vision processing on-board small autonomous vehicles. Local vision gives increased autonomous capability, but it requires substantial computing power that is difficult to provide given the severe constraints of small size and battery-powered operation. We describe a custom FPGA-based circuit board designed to support research in the development of algorithms for image-directed navigation and control. We show that the FPGA approach supports real-time vision algorithms by describing the implementation of an algorithm to construct a three-dimensional (3D map of the environment surrounding a small mobile robot. We show that FPGAs are well suited for systems that must be flexible and deliver high levels of performance, especially in embedded settings where space and power are significant concerns.

  11. Reconfigurable On-Board Vision Processing for Small Autonomous Vehicles

    Directory of Open Access Journals (Sweden)

    Fife WadeS

    2007-01-01

    Full Text Available This paper addresses the challenge of supporting real-time vision processing on-board small autonomous vehicles. Local vision gives increased autonomous capability, but it requires substantial computing power that is difficult to provide given the severe constraints of small size and battery-powered operation. We describe a custom FPGA-based circuit board designed to support research in the development of algorithms for image-directed navigation and control. We show that the FPGA approach supports real-time vision algorithms by describing the implementation of an algorithm to construct a three-dimensional (3D map of the environment surrounding a small mobile robot. We show that FPGAs are well suited for systems that must be flexible and deliver high levels of performance, especially in embedded settings where space and power are significant concerns.

  12. On-Board Software Reference Architecture for Payloads

    Science.gov (United States)

    Bos, Victor; Rugina, Ana; Trcka, Adam

    2016-08-01

    The goal of the On-board Software Reference Architecture for Payloads (OSRA-P) is to identify an architecture for payload software to harmonize the payload domain, to enable more reuse of common/generic payload software across different payloads and missions and to ease the integration of the payloads with the platform.To investigate the payload domain, recent and current payload instruments of European space missions have been analyzed. This led to a Payload Catalogue describing 12 payload instruments as well as a Capability Matrix listing specific characteristics of each payload. In addition, a functional decomposition of payload software was prepared which contains functionalities typically found in payload systems. The definition of OSRA-P was evaluated by case studies and a dedicated OSRA-P workshop to gather feedback from the payload community.

  13. Subpixel jitter video restoration on board of micro-UAV

    Science.gov (United States)

    Szu, Harold H.; Buss, James R.; Garcia, Joseph P.; Breaux, Nancy A.; Kopriva, Ivica; Karangelen, Nicholas E.; Hsu, M.; Lee, Ting; Willey, Jeff; Shield, Gary; Brown, Steve; Robbins, R.; Hobday, John

    2004-04-01

    We review various image processing algorithms for micro-UAV EO/IR sub-pixel jitter restoration. Since the micro-UAV, Silver Fox, cannot afford isolation coupling mounting from the turbulent aerodynamics of the airframe, we explore smart real-time software to mitigate the sub-pixel jitter effect. We define jitter to be sub-pixel or small-amplitude vibrations up to one pixel, as opposed to motion blur over several pixels for which there already exists real time correction algorithms used on other platforms. We divide the set of jitter correction algorithms into several categories: They are real time, pseudo-real time, or non-real-time, but they are all standalone, i.e. without relying on a library storage or flight data basis on-board the UAV. The top of the list is demonstrated and reported here using real-world data and a truly unsupervised, real-time algorithm.

  14. Thermal Stability of the AVIRIS On-Board Calibrator

    Science.gov (United States)

    Faust, Jessica; Eastwood, Michael; Sarture, Chuck; Williams, Orlesa

    1998-01-01

    The AVIRIS On-Board Calibrator (OBC) provides essential data for refining the calibration of each AVIRIS data run. Annual improvement to the AVIRIS sensor and laboratory calibration accuracy has resulted in increasingly high demands on the stability of the OBC. Since the 1995 flight season, the OBC could track the stability of the spectrometer alignment to the 2% level, a significant improvement over previous years. The major contributor to this 2% stability was the conversion from a constant-current bulb power supply to an intensity-based active feedback power supply. Given the high sensor signal-to-noise ratio, improving the OBC to track 1% or 0.5% changes was highly desirable. Achieving stability better than 2% required an examination of the mechanisms affecting stability.

  15. On-board data processing for the near infrared spectrograph and photometer instrument (NISP) of the EUCLID mission

    Science.gov (United States)

    Bonoli, Carlotta; Balestra, Andrea; Bortoletto, Favio; D'Alessandro, Maurizio; Farinelli, Ruben; Medinaceli, Eduardo; Stephen, John; Borsato, Enrico; Dusini, Stefano; Laudisio, Fulvio; Sirignano, Chiara; Ventura, Sandro; Auricchio, Natalia; Corcione, Leonardo; Franceschi, Enrico; Ligori, Sebastiano; Morgante, Gianluca; Patrizii, Laura; Sirri, Gabriele; Trifoglio, Massimo; Valenziano, Luca

    2016-07-01

    The Near Infrared Spectrograph and Photometer (NISP) is one of the two instruments on board the EUCLID mission now under implementation phase; VIS, the Visible Imager is the second instrument working on the same shared optical beam. The NISP focal plane is based on a detector mosaic deploying 16x, 2048x2048 pixels^2 HAWAII-II HgCdTe detectors, now in advanced delivery phase from Teledyne Imaging Scientific (TIS), and will provide NIR imaging in three bands (Y, J, H) plus slit-less spectroscopy in the range 0.9÷2.0 micron. All the NISP observational modes will be supported by different parametrization of the classic multi-accumulation IR detector readout mode covering the specific needs for spectroscopic, photometric and calibration exposures. Due to the large number of deployed detectors and to the limited satellite telemetry available to ground, a consistent part of the data processing, conventionally performed off-line, will be accomplished on board, in parallel with the flow of data acquisitions. This has led to the development of a specific on-board, HW/SW, data processing pipeline, and to the design of computationally performing control electronics, suited to cope with the time constraints of the NISP acquisition sequences during the sky survey. In this paper we present the architecture of the NISP on-board processing system, directly interfaced to the SIDECAR ASICs system managing the detector focal plane, and the implementation of the on-board pipe-line allowing all the basic operations of input frame averaging, final frame interpolation and data-volume compression before ground down-link.

  16. MicroCameras and Photometers (MCP) on board TARANIS satellite

    Science.gov (United States)

    Farges, Thomas; Blanc, Elisabeth; Hébert, Philippe; Le Mer-Dachard, Fanny; Ravel, Karen; Gaillac, Stéphanie

    2017-04-01

    TARANIS (Tool for the Analysis of Radiations from lightNings and Sprites) is a CNES micro satellite. Its main objective is to study impulsive transfers of energy between the Earth atmosphere and the space environment. It will be sun-synchronous at an altitude of 700 km. It will be launched from end-2018 for at least 2 years. Its payload is composed of several electromagnetic instruments in different wavelengths (from gamma-rays to radio waves including optical). TARANIS instruments are currently in calibration and qualification phase. The purpose of this poster is to present the MicroCameras and Photometers (MCP) scientific objectives and the sensor design, to show the performances of this instrument using the recent characterization, and at last to promote its products. The MicroCameras, developed by Sodern, are dedicated to the spatial description of TLEs and their parent lightning. They are able to differentiate sprite and lightning thanks to two narrow bands ([757-767 nm] and [772-782 nm]) that provide simultaneous pairs of images of an Event. Simulation results of the differentiation method will be shown. After calibration and tests, the MicroCameras are now delivered to CNES for integration on the payload. The Photometers, developed by Bertin Technologies, will provide temporal measurements and spectral characteristics of TLEs and lightning. There are key instrument because of their capability to detect on-board TLEs and then switch all the instruments of the scientific payload in their high resolution acquisition mode. Photometers use four spectral bands in the [170-260 nm], [332-342 nm], [757-767 nm] and [600-900 nm] and have the same field of view as cameras. The on-board TLE detection algorithm remote-controlled parameters have been tuned before launch using the electronic board and simulated or real events waveforms. The Photometers are now in the calibration and test phase. They will be delivered for integration in mid-2017.

  17. Fluxes of energetic protons and electrons measured on board the Oersted satellite

    Directory of Open Access Journals (Sweden)

    J. Cabrera

    2005-11-01

    Full Text Available The Charged Particle Detector (CPD on board the Oersted satellite (649 km perigee, 865 km apogee and 96.48° inclination currently measures energetic protons and electrons. The measured peak fluxes of E>1 MeV electrons are found to confirm the predictions of AE8-MAX, though they occur at a geographical position relatively shifted in the SAA. The fluxes of protons are one order of magnitude higher than the predictions of AP8-MAX in the energy range 20-500 MeV. This huge discrepancy between AP8 and recent measurements in LEO was already noticed and modelled in SAMPEX/PSB97 and TPM-1 models. Nevertheless some other LEO measurements such as PROBA and CORONA-F result in flux values in good agreement with AP8 within a factor 2. The anisotropy of the low-altitude proton flux, combined with measurement performed on board three-axis stabilised satellites, has been suspected to be one possible source of the important discrepancies observed by different missions. In this paper, we evaluate the effect of anisotropy on flux measurements conducted using the CPD instruments. On the basis of the available data, we confirm the inaccuracy of AP8 at LEO and suggest methods to improve the analysis of data in future flux measurements of energetic protons at low altitudes.

  18. Concepts for on board satellite image registration. Volume 4: Impact of data set selection on satellite on board signal processing

    Science.gov (United States)

    Ruedger, W. H.; Aanstoos, J. V.; Snyder, W. E.

    1982-01-01

    The NASA NEEDS program goals present a requirement for on-board signal processing to achieve user-compatible, information-adaptive data acquisition. This volume addresses the impact of data set selection on data formatting required for efficient telemetering of the acquired satellite sensor data. More specifically, the FILE algorithm developed by Martin-Marietta provides a means for the determination of those pixels from the data stream effects an improvement in the achievable system throughput. It will be seen that based on the lack of statistical stationarity in cloud cover, spatial distribution periods exist where data acquisition rates exceed the throughput capability. The study therefore addresses various approaches to data compression and truncation as applicable to this sensor mission.

  19. Asymmetric Patterns of Small Molecule Transport After Nanosecond and Microsecond Electropermeabilization.

    Science.gov (United States)

    Sözer, Esin B; Pocetti, C Florencia; Vernier, P Thomas

    2017-05-08

    Imaging of fluorescent small molecule transport into electropermeabilized cells reveals polarized patterns of entry, which must reflect in some way the mechanisms of the migration of these molecules across the compromised membrane barrier. In some reports, transport occurs primarily across the areas of the membrane nearest the positive electrode (anode), but in others cathode-facing entry dominates. Here we compare YO-PRO-1, propidium, and calcein uptake into U-937 cells after nanosecond (6 ns) and microsecond (220 µs) electric pulse exposures. Each of the three dyes exhibits a different pattern. Calcein shows no preference for anode- or cathode-facing entry that is detectable with our measurement system. Immediately after a microsecond pulse, YO-PRO-1 and propidium enter the cell roughly equally from the positive and negative poles, but transport through the cathode-facing side dominates in less than 1 s. After nanosecond pulse permeabilization, YO-PRO-1 and propidium enter primarily on the anode-facing side of the cell.

  20. Fiber optical sensing on-board communication satellites

    Science.gov (United States)

    Hurni, A.; Lemke, N. M. K.; Roner, M.; Obermaier, J.; Putzer, P.; Kuhenuri Chami, N.

    2017-11-01

    Striving constantly to reduce mass, AIT effort and overall cost of the classical point-to-point wired temperature sensor harness on-board telecommunication satellites, OHB System (formerly Kayser-Threde) has introduced the Hybrid Sensor Bus (HSB) system. As a future spacecraft platform element, HSB relies on electrical remote sensor units as well as fiber-optical sensors, both of which can serially be connected in a bus architecture. HSB is a modular measurement system with many applications, also thanks to the opportunities posed by the digital I²C bus. The emphasis, however, is on the introduction of fiber optics and especially fiber-Bragg grating (FBG) temperature sensors as disruptive innovation for the company's satellite platforms. The light weight FBG sensors are directly inscribed in mechanically robust and radiation tolerant fibers, reducing the need for optical fiber connectors and splices to a minimum. Wherever an FBG sensor shall be used, the fiber is glued together with a corresponding temperature transducer to the satellites structure or to a subsystem. The transducer is necessary to provide decoupling of mechanical stress, but simultaneously ensure a high thermal conductivity. HSB has been developed in the frame of an ESA-ARTES program with European and German co-funding and will be verified as flight demonstrator on-board the German Heinrich Hertz satellite (H2Sat). In this paper the Engineering Model development of HSB is presented and a Fiber-optical Sensor Multiplexer for a more flexible sensor bus architecture is introduced. The HSB system aims at telecommunication satellite platforms with an operational life time beyond 15 years in geostationary orbit. It claims a high compatibility in terms of performance and interfaces with existing platforms while it was designed with future applications with increased radiation exposure already in mind. In its basic configuration HSB consists of four modules which are the Power Supply Unit, the HSB

  1. Registration of the Atmospheric Gamma Radiation on Board the Russian Segment of the International Space Station

    Science.gov (United States)

    Andreevsky, S. E.; Kuznetsov, V. D.; Sinelnikov, V. M.

    2017-03-01

    The paper describes the complex of scientific instruments and the algorithm of the "Molniya-Gamma" experiment on measuring gamma-ray fluxes in the energy range of 32-750 keV carried out in 2011 on board the Russian Segment (RS) of the International Space Station (ISS). About 500 thousand energy spectra with a time resolution of 1 min were obtained in 512 energy channels during 232 days. One-second variations in the number of gamma quanta in four energy channels and the triggered fluxes of gamma quanta lasting less than 100 ms were recorded simultaneously. The data obtained allow us to study temporal and spatial variation of gamma-ray radiation to detect terrestrial gamma flashes (TGFs). Data on very large number of gamma-ray spikes were acquired through a trigger data mode with a low threshold.

  2. On-Board Detection and Matching of Feature Points

    Directory of Open Access Journals (Sweden)

    Jingjin Huang

    2017-06-01

    Full Text Available This paper presents a FPGA-based method for on-board detection and matching of the feature points. With the proposed method, a parallel processing model and a pipeline structure are presented to ensure a high frame rate at processing speed, but with a low power consumption. To save the FPGA resources and increase the processing speed, a model which combines the modified SURF detector and a BRIEF descriptor, is presented as well. Three pairs of images with different land coverages are used to evaluate the performance of FPGA-based implementation. The experiment results demonstrate that (1 when the image pairs with artificial features (such as buildings and roads, the performance of FPGA-based implementation is better than those image pairs with natural features (such as woods; (2 the proposed FPGA-based method is capable of ensuring the processing speed at a high frame rate, such as the speed of can achieve 304 fps under a 100 MHz clock frequency. The speedup of the proposed implementation is about 27 times higher than that when using the PC-based implementation.

  3. Survey on food hygiene knowledge on board ships.

    Science.gov (United States)

    Grappasonni, Iolanda; Marconi, Donatella; Mazzucchi, Fabrizio; Petrelli, Fabio; Scuri, Stefania; Amenta, Francesco

    2013-01-01

    The aim of the study was to evaluate the knowledge and attitudes on food hygiene in seafarers. The study was conducted using an anonymous questionnaire presented to the workers of 7 tankers of an Italian shipping company (Finaval S.p.A.). As a reference, the analysis was extended to office employees of the same firm. Data were divided according to the rank of seafarers to assess possible differences in perceiving the risk. Overall knowledge on food safety concept was not high among seafarers. In general, galley and catering workers group provided a lower percentage of correct answers than other crew members. Foodservices staff revealed little awareness of the risks linked with handling food and their perception of risk of disease transmission through food was low. Answers about risk related to specific food (eggs and fish) showed that knowledge about these problems was less than satisfactory. Moreover, the percentage of 'I don't know' answers was high. These findings suggest that this personnel is aware of the right stepsof health protection in terms of food hygiene, but does not understand why it is necessary. Galley and catering group workers were not the most informed about food hygiene problems.This highlights the need to hire qualified personnel of the food industry on board ships. All those working inthe food service area should be properly trained on food hygiene. Seafarers should be the target of specificinformative campaigns about health risks linked with aliments, possible consequences of it and also oneson how to minimise the exposure to potentially dangerous agents/behaviours during travel/life at sea.

  4. STROBE-X: X-ray Timing & Spectroscopy on Dynamical Timescales from Microseconds to Years

    DEFF Research Database (Denmark)

    Wilson-Hodge, C.~A.; Ray, P. S.; Maccarone, T. J.

    We describe a probe-class mission concept that provides an unprecedentedview of the X-ray sky, performing timing and 0.2-30 keV spectroscopy overtimescales from microseconds to years. The Spectroscopic Time-Resolving Observatory for Broadband Energy X-rays (STROBE-X) comprises three primary......, with enhanced optics to take advantage of the longer focal length of STROBE-X. The second uses large-area collimated silicon drift detectors, developed for ESA's LOFT, to cover the 2-30 keV band. These two instruments each provide an order of magnitude improvement ineffective area compared with its predecessor...... (NICER and RXTE, respectively). Finally, a sensitive sky monitor triggers pointed observations, provides high duty cycle, high time resolution, high spectral resolution monitoring of the X-ray sky with ~20 times the sensitivity of the RXTE ASM,and enables multi-wavelength and multi-messenger studies...

  5. Experimental study of n-decane decomposition with microsecond pulsed discharge plasma

    Science.gov (United States)

    Feilong, SONG; Di, JIN; Min, JIA; Wenwen, WEI; Huimin, SONG; Yun, WU

    2017-12-01

    A highly-integrated experimental system for the plasma decomposition of fuels was built. Experiments were conducted in a flow reactor at atmospheric pressure and confirmed that n-decane could be cracked by large-gap dielectric barrier discharge under the excitation of a microsecond-pulse power supply. Alkanes and olefins with a C atom number that is smaller than 10 as well as hydrogen were found in the cracked products of n-decane (n-C10H22). The combination of preheating and plasma decomposition had strong selectivity for olefins. Under strong discharge conditions, small molecule olefins were found in the products. Moreover, there was a general tendency that small molecule olefins gradually accounted for higher percentage of products at higher temperature and discharge frequency.

  6. Simulating the Thermal Response of High Explosives on Time Scales of Days to Microseconds

    Energy Technology Data Exchange (ETDEWEB)

    Yoh, J J; McClelland, M A

    2003-07-16

    We present an overview of computational techniques for simulating the thermal cookoff of high explosives using a multi-physics hydrodynamics code, ALE3D. Recent improvements to the code have aided our computational capability in modeling the response of energetic materials systems exposed to extreme thermal environments, such as fires. We consider an idealized model process for a confined explosive involving the transition from slow heating to rapid deflagration in which the time scale changes from days to hundreds of microseconds. The heating stage involves thermal expansion and decomposition according to an Arrhenius kinetics model while a pressure-dependent burn model is employed during the explosive phase. We describe and demonstrate the numerical strategies employed to make the transition from slow to fast dynamics.

  7. Photon-by-Photon Hidden Markov Model Analysis for Microsecond Single-Molecule FRET Kinetics.

    Science.gov (United States)

    Pirchi, Menahem; Tsukanov, Roman; Khamis, Rashid; Tomov, Toma E; Berger, Yaron; Khara, Dinesh C; Volkov, Hadas; Haran, Gilad; Nir, Eyal

    2016-12-29

    The function of biological macromolecules involves large-scale conformational dynamics spanning multiple time scales, from microseconds to seconds. Such conformational motions, which may involve whole domains or subunits of a protein, play a key role in allosteric regulation. There is an urgent need for experimental methods to probe the fastest of these motions. Single-molecule fluorescence experiments can in principle be used for observing such dynamics, but there is a lack of analysis methods that can extract the maximum amount of information from the data, down to the microsecond time scale. To address this issue, we introduce H 2 MM, a maximum likelihood estimation algorithm for photon-by-photon analysis of single-molecule fluorescence resonance energy transfer (FRET) experiments. H 2 MM is based on analytical estimators for model parameters, derived using the Baum-Welch algorithm. An efficient and effective method for the calculation of these estimators is introduced. H 2 MM is shown to accurately retrieve the reaction times from ∼1 s to ∼10 μs and even faster when applied to simulations of freely diffusing molecules. We further apply this algorithm to single-molecule FRET data collected from Holliday junction molecules and show that at low magnesium concentrations their kinetics are as fast as ∼10 4 s -1 . The new algorithm is particularly suitable for experiments on freely diffusing individual molecules and is readily incorporated into existing analysis packages. It paves the way for the broad application of single-molecule fluorescence to study ultrafast functional dynamics of biomolecules.

  8. Analysis of On-Board Photovoltaics for a Battery Electric Bus and Their Impact on Battery Lifespan

    Directory of Open Access Journals (Sweden)

    Kevin R. Mallon

    2017-07-01

    Full Text Available Heavy-duty electric powertrains provide a potential solution to the high emissions and low fuel economy of trucks, buses, and other heavy-duty vehicles. However, the cost, weight, and lifespan of electric vehicle batteries limit the implementation of such vehicles. This paper proposes supplementing the battery with on-board photovoltaic modules. In this paper, a bus model is created to analyze the impact of on-board photovoltaics on electric bus range and battery lifespan. Photovoltaic systems that cover the bus roof and bus sides are considered. The bus model is simulated on a suburban bus drive cycle on a bus route in Davis, CA, USA for a representative sample of yearly weather conditions. Roof-mounted panels increased vehicle driving range by 4.7% on average annually, while roof and side modules together increased driving range by 8.9%. However, variations in weather conditions meant that this additional range was not reliably available. For constant vehicle range, rooftop photovoltaic modules extended battery cycle life by up to 10% while modules on both the roof and sides extended battery cycle life by up to 19%. Although side-mounted photovoltaics increased cycle life and range, they were less weight- and cost-effective compared to the roof-mounted panels.

  9. 46 CFR 147.15 - Hazardous ships' stores permitted on board vessels.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Hazardous ships' stores permitted on board vessels. 147... HAZARDOUS SHIPS' STORES General Provisions § 147.15 Hazardous ships' stores permitted on board vessels...' stores if the material— (a) Is labeled according to § 147.30; and (b) Meets the requirements, if any, in...

  10. An overview of CAFE credits and incorporation of the benefits of on-board carbon capture.

    Science.gov (United States)

    2014-05-01

    This report discusses the application of Corporate Average Fuel Economy (CAFE) : credits that are currently available to vehicle manufacturers in the U.S., and the implications of : on-board carbon capture and sequestration (on-board CCS) on fu...

  11. 49 CFR 395.15 - Automatic on-board recording devices.

    Science.gov (United States)

    2010-10-01

    ... information concerning on-board system sensor failures and identification of edited data. Such support systems... each record; (2) The driver shall review and verify that all entries are accurate prior to submission...-driver operation; (7) The on-board recording device/system identifies sensor failures and edited data...

  12. Combination of microsecond and nanosecond pulsed electric field treatments for inactivation of Escherichia coli in water samples.

    Science.gov (United States)

    Žgalin, Maj Kobe; Hodžić, Duša; Reberšek, Matej; Kandušer, Maša

    2012-10-01

    Inactivation of microorganisms with pulsed electric fields is one of the nonthermal methods most commonly used in biotechnological applications such as liquid food pasteurization and water treatment. In this study, the effects of microsecond and nanosecond pulses on inactivation of Escherichia coli in distilled water were investigated. Bacterial colonies were counted on agar plates, and the count was expressed as colony-forming units per milliliter of bacterial suspension. Inactivation of bacterial cells was shown as the reduction of colony-forming units per milliliter of treated samples compared to untreated control. According to our results, when using microsecond pulses the level of inactivation increases with application of more intense electric field strengths and with number of pulses delivered. Almost 2-log reductions in bacterial counts were achieved at a field strength of 30 kV/cm with eight pulses and a 4.5-log reduction was observed at the same field strength using 48 pulses. Extending the duration of microsecond pulses from 100 to 250 μs showed no improvement in inactivation. Nanosecond pulses alone did not have any detectable effect on inactivation of E. coli regardless of the treatment time, but a significant 3-log reduction was achieved in combination with microsecond pulses.

  13. Selected Problems In Controlling On-Board Direct And Alternating Current Systems

    Directory of Open Access Journals (Sweden)

    Gębura Andrzej

    2015-08-01

    Full Text Available The article addresses in a complex way the problem of cooperation between the on-board electric power sources of an aircraft with its on-board electric network. The authors paid special attention to conditions related to correct switching of the on-board electric power sources. Structural protection of the electric power sources against harmful impact of loads, and of the loads against incorrectly operating sources, as well as certain methods to counteract such phenomena, are discussed. Exploring these relations will enable the user to undertake actions which can reduce the failure rate of the on-board electrical power network, and ensure power supply to the electrical loads under all flight conditions. Their correct operation determines correct operation of the on-board electrical power network. The authors tried to discuss all the problems in the most universal way possible, so the deliberations presented here could be helpful in analyzing defects in various aircrafts.

  14. Legionella on board trains: effectiveness of environmental surveillance and decontamination.

    Science.gov (United States)

    Quaranta, Gianluigi; Vincenti, Sara; Ferriero, Anna Maria; Boninti, Federica; Sezzatini, Romina; Turnaturi, Cinzia; Gliubizzi, Maria Daniela; Munafò, Elio; Ceccarelli, Gianluca; Causarano, Carmelo; Accorsi, Massimo; Del Nord, Pasquale; Ricciardi, Walter; Laurenti, Patrizia

    2012-08-07

    Legionella pneumophila is increasingly recognised as a significant cause of sporadic and epidemic community-acquired and nosocomial pneumonia. Many studies describe the frequency and severity of Legionella spp. contamination in spa pools, natural pools, hotels and ships, but there is no study analysing the environmental monitoring of Legionella on board trains. The aims of the present study were to conduct periodic and precise environmental surveillance of Legionella spp. in water systems and water tanks that supply the toilet systems on trains, to assess the degree of contamination of such structures and to determine the effectiveness of decontamination. A comparative pre-post ecological study was conducted from September 2006 to January 2011. A total of 1,245 water samples were collected from plumbing and toilet water tanks on passenger trains. The prevalence proportion of all positive samples was calculated. The unpaired t-test was performed to evaluate statistically significant differences between the mean load values before and after the decontamination procedures; statistical significance was set at p ≤ 0.05. In the pre-decontamination period, 58% of the water samples were positive for Legionella. Only Legionella pneumophila was identified: 55.84% were serogroup 1, 19.03% were serogroups 2-14 and 25.13% contained both serogroups. The mean bacterial load value was 2.14 × 10(3) CFU/L. During the post-decontamination period, 42.75% of water samples were positive for Legionella spp.; 98.76% were positive for Legionella pneumophila: 74.06% contained serogroup 1, 16.32% contained serogroups 2-14 and 9.62% contained both. The mean bacterial load in the post-decontamination period was 1.72 × 10(3) CFU/L. According to the t-test, there was a statistically significant decrease in total bacterial load until approximately one and a half year after beginning the decontamination programme (p = 0.0097). This study indicates that systematic environmental surveillance

  15. Legionella on board trains: effectiveness of environmental surveillance and decontamination

    Directory of Open Access Journals (Sweden)

    Quaranta Gianluigi

    2012-08-01

    Full Text Available Abstract Background Legionella pneumophila is increasingly recognised as a significant cause of sporadic and epidemic community-acquired and nosocomial pneumonia. Many studies describe the frequency and severity of Legionella spp. contamination in spa pools, natural pools, hotels and ships, but there is no study analysing the environmental monitoring of Legionella on board trains. The aims of the present study were to conduct periodic and precise environmental surveillance of Legionella spp. in water systems and water tanks that supply the toilet systems on trains, to assess the degree of contamination of such structures and to determine the effectiveness of decontamination. Methods A comparative pre-post ecological study was conducted from September 2006 to January 2011. A total of 1,245 water samples were collected from plumbing and toilet water tanks on passenger trains. The prevalence proportion of all positive samples was calculated. The unpaired t-test was performed to evaluate statistically significant differences between the mean load values before and after the decontamination procedures; statistical significance was set at p ≤ 0.05. Results In the pre-decontamination period, 58% of the water samples were positive for Legionella. Only Legionella pneumophila was identified: 55.84% were serogroup 1, 19.03% were serogroups 2–14 and 25.13% contained both serogroups. The mean bacterial load value was 2.14 × 103 CFU/L. During the post-decontamination period, 42.75% of water samples were positive for Legionella spp.; 98.76% were positive for Legionella pneumophila: 74.06% contained serogroup 1, 16.32% contained serogroups 2–14 and 9.62% contained both. The mean bacterial load in the post-decontamination period was 1.72 × 103 CFU/L. According to the t-test, there was a statistically significant decrease in total bacterial load until approximately one and a half year after beginning the decontamination programme (p

  16. HTML 5 Displays for On-Board Flight Systems

    Science.gov (United States)

    Silva, Chandika

    2016-01-01

    During my Internship at NASA in the summer of 2016, I was assigned to a project which dealt with developing a web-server that would display telemetry and other system data using HTML 5, JavaScript, and CSS. By doing this, it would be possible to view the data across a variety of screen sizes, and establish a standard that could be used to simplify communication and software development between NASA and other countries. Utilizing a web- approach allowed us to add in more functionality, as well as make the displays more aesthetically pleasing for the users. When I was assigned to this project my main task was to first establish communication with the current display server. This display server would output data from the on-board systems in XML format. Once communication was established I was then asked to create a dynamic telemetry table web page that would update its header and change as new information came in. After this was completed, certain minor functionalities were added to the table such as a hide column and filter by system option. This was more for the purpose of making the table more useful for the users, as they can now filter and view relevant data. Finally my last task was to create a graphical system display for all the systems on the space craft. This was by far the most challenging part of my internship as finding a JavaScript library that was both free and contained useful functions to assist me in my task was difficult. In the end I was able to use the JointJs library and accomplish the task. With the help of my mentor and the HIVE lab team, we were able to establish stable communication with the display server. We also succeeded in creating a fully dynamic telemetry table and in developing a graphical system display for the advanced modular power system. Working in JSC for this internship has taught me a lot about coding in JavaScript and HTML 5. I was also introduced to the concept of developing software as a team, and exposed to the different

  17. Detailed Design of On-Board and Ground Segment

    DEFF Research Database (Denmark)

    Thuesen, Gøsta

    1998-01-01

    Image processing, attitude determination, quaternion estimation, and performance test of short range camera for rendez-vous and docking of spacecraft.......Image processing, attitude determination, quaternion estimation, and performance test of short range camera for rendez-vous and docking of spacecraft....

  18. Electrical control of calcium oscillations in mesenchymal stem cells using microsecond pulsed electric fields.

    Science.gov (United States)

    Hanna, Hanna; Andre, Franck M; Mir, Lluis M

    2017-04-20

    Human mesenchymal stem cells are promising tools for regenerative medicine due to their ability to differentiate into many cellular types such as osteocytes, chondrocytes and adipocytes amongst many other cell types. These cells present spontaneous calcium oscillations implicating calcium channels and pumps of the plasma membrane and the endoplasmic reticulum. These oscillations regulate many basic functions in the cell such as proliferation and differentiation. Therefore, the possibility to mimic or regulate these oscillations might be useful to regulate mesenchymal stem cells biological functions. One or several electric pulses of 100 μs were used to induce Ca 2+ spikes caused by the penetration of Ca 2+ from the extracellular medium, through the transiently electropermeabilized plasma membrane, in human adipose mesenchymal stem cells from several donors. Attached cells were preloaded with Fluo-4 AM and exposed to the electric pulse(s) under the fluorescence microscope. Viability was also checked. According to the pulse(s) electric field amplitude, it is possible to generate a supplementary calcium spike with properties close to those of calcium spontaneous oscillations, or, on the contrary, to inhibit the spontaneous calcium oscillations for a very long time compared to the pulse duration. Through that inhibition of the oscillations, Ca 2+ oscillations of desired amplitude and frequency could then be imposed on the cells using subsequent electric pulses. None of the pulses used here, even those with the highest amplitude, caused a loss of cell viability. An easy way to control Ca 2+ oscillations in mesenchymal stem cells, through their cancellation or the addition of supplementary Ca 2+ spikes, is reported here. Indeed, the direct link between the microsecond electric pulse(s) delivery and the occurrence/cancellation of cytosolic Ca 2+ spikes allowed us to mimic and regulate the Ca 2+ oscillations in these cells. Since microsecond electric pulse delivery

  19. Ultrafast x-ray photoelectron spectroscopy in the microsecond time domain

    Energy Technology Data Exchange (ETDEWEB)

    Höfert, O.; Gleichweit, C.; Steinrück, H.-P.; Papp, C. [Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen (Germany)

    2013-09-15

    We introduce a new approach for ultrafast in situ high-resolution X-ray photoelectron spectroscopy (XPS) to study surface processes and reaction kinetics on the microsecond timescale. The main idea is to follow the intensity at a fixed binding energy using a commercial 7 channeltron electron analyzer with a modified signal processing setup. This concept allows for flexible switching between measuring conventional XP spectra and ultrafast XPS. The experimental modifications are described in detail. As an example, we present measurements for the adsorption and desorption of CO on Pt(111), performed at the synchrotron radiation facility BESSY II, with a time resolution of 500 μs. Due to the ultrafast measurements, we are able to follow adsorption and desorption in situ at pressures of 2 × 10{sup −6} mbar and temperatures up to 500 K. The data are consistently analyzed using a simple model in line with data obtained with conventional fast XPS at temperatures below 460 K. Technically, our new approach allows measurement on even shorter timescales, down to 20 μs.

  20. Microsecond Electron Beam Source with Electron Energy Up to 400 Kev and Plasma Anode

    Science.gov (United States)

    Abdullin, É. N.; Basov, G. F.; Shershnev, S.

    2017-12-01

    A new high-power source of electrons with plasma anode for producing high-current microsecond electron beams with electron energy up to 400 keV has been developed, manufactured, and put in operation. To increase the cross section and pulse current duration of the beam, a multipoint explosive emission cathode is used in the electron beam source, and the beam is formed in an applied external guiding magnetic field. The Marx generator with vacuum insulation is used as a high-voltage source. Electron beams with electron energy up to 300-400 keV, current of 5-15 kA, duration of 1.5-3 μs, energy up to 4 kJ, and cross section up to 150 cm2 have been produced. The operating modes of the electron beam source are realized in which the applied voltage is influenced weakly on the current. The possibility of source application for melting of metal surfaces is demonstrated.

  1. Do Women On Boards And In Top Management Reduce Earnings Management? Evidence In France

    National Research Council Canada - National Science Library

    Faten Lakhal; Amal Aguir; Nadia Lakhal; Adnane Malek

    2015-01-01

    .... We also find that the relationship between the presence of at least three women on the board and earnings management is negative suggesting that by increasing the number of women on board through...

  2. On-Board Engine Exhaust Particulate Matter Sensor for HCCI and Conventional Diesel Engines

    Energy Technology Data Exchange (ETDEWEB)

    Hall, Matt; Matthews, Ron

    2011-09-30

    The goal of the research was to refine and complete development of an on-board particulate matter (PM) sensor for diesel, DISI, and HCCI engines, bringing it to a point where it could be commercialized and marketed.

  3. On-Board Thermal Management of Waste Heat from a High-Energy Device

    National Research Council Canada - National Science Library

    Klatt, Nathan D

    2008-01-01

    The use of on-board high-energy devices such as megawatt lasers and microwave emitters requires aircraft system integration of thermal devices to either get rid of waste heat or utilize it in other areas of the aircraft...

  4. On-Board Preventive Maintenance: Analysis of Effectiveness Optimal Duty Period

    Science.gov (United States)

    Tai, Ann T.; Chau, Savio N.; Alkalaj, Leon; Hecht, Herbert

    1996-01-01

    To maximize reliability of a spacecraft which performs long-life (over 10-year), deep-space mission (to outer planet), a fault-tolerant environment incorporating automatic on-board preventive maintenance is highly desirable.

  5. Advanced Hybrid On-Board Data Processor - SpaceCube 2.0 Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop advanced on-board processing to meet the requirements of the Decadal Survey missions: advanced instruments (hyper-spectral, SAR, etc) require advanced...

  6. Improving Inspection and Maintenance Performance and On-board Diagnostics Monitor Readiness Memo

    Science.gov (United States)

    This EPA memorandum transmits an updated list of vehicles that exhibit issues related to OBD (on board diagnostics) monitor readiness and makes suggestions for how Inspection/Maintenance (I/M) programs can improve operational performance by addressing

  7. Current Status of Observation by the Longwave Infrared Camera (LIR) on Board Akatsuki Spacecraft

    Science.gov (United States)

    Fukuhara, T.; Taguchi, M.; Imamura, T.; Kouyama, T.; Nakamura, M.; Sato, T. M.; Suzuki, M.; Iwagami, N.

    2017-11-01

    Current status of observation by the Longwave Infrared Camera (LIR) on board Akatsuki spacecraft is reported. We advance the study by using the abundant LIR images, and various large stationary gravity waves have been identified in LIR images.

  8. On-board sound intensity tire-pavement noise study in North Carolina.

    Science.gov (United States)

    2011-12-01

    "This research investigated tire-pavement noise on various types of pavements across North Carolina by using On- : Board Sound Intensity (OBSI) method. To mitigate traffic noise, quieter pavement may provide advantages that : noise barriers cannot. T...

  9. On Board Sensor Network: A Proof of Concept Aiming at Telecom I/O Optimisation

    Science.gov (United States)

    Gunes-Lasnet, S.; Furano, G.; Melicher, M.; Gleeson, D.; O'Connor, W.; Vidaud, O.; Notebaert, O.

    2009-05-01

    On-board sensor networks proof of concept is part of a long haul strategy shared between ESA and the European industry. Because point to point interfaces are numerous in a spacecraft, initiatives to standardise them or replace them by bus solutions have been seeked commonly between ESA and the industry. The sensor networks project presented in this paper aims at defining and prototyping a solution for spacecraft on board sensor networks, and to perform a proof of concept with the resulting demonstrator.

  10. Wire Array Z-pinches on Sphinx Machine: Experimental Results and Relevant Points of Microsecond Implosion Physics

    Science.gov (United States)

    Calamy, H.; Hamann, F.; Lassalle, F.; Bayol, F.; Mangeant, C.; Morell, A.; Huet, D.; Bedoch, J. P.; Chittenden, J. P.; Lebedev, S. V.; Jennings, C. A.; Bland, S. N.

    2006-01-01

    Centre d'Etudes de Gramat (France) has developed an efficient long implosion time (800 ns) Aluminum plasma radiation source (PRS). Based on the LTD technology, the SPHINX facility is developed as a 1-3MJ, 1μs rise time, 4-10 MA current driver. In this paper, it was used in 1MJ, 4MA configuration to drive Aluminum nested wire arrays Z-pinches with K-shell yield up to 20 kJ and a FWHM of the x-ray pulse of about 50 ns. We present latest SPHINX experiments and some of the main physic issues of the microsecond regime. Experimental setup and results are described with the aim of giving trends that have been obtained. The main features of microsecond implosion of wire arrays can be analyzed thanks to same methods and theories as used for faster Z-pinches. The effect of load polarity was examined. The stability of the implosion , one of the critical point of microsecond wire arrays due to the load dimensions imposed by the time scale, is tackled. A simple scaling from 100 ns Z-pinch results to 800 ns ones gives good results and the use of nested arrays improves dramatically the implosion quality and the Kshell yield of the load. However, additional effects such as the impact of the return current can geometry on the implosion have to be taken into account on our loads. Axial inhomogeneity of the implosion the origin of which is not yet well understood occurs in some shots and impacts the radiation output. The shape of the radiative pulse is discussed and compared with the homogeneity of the implosion. Numerical 2D R-Z and R-θ simulations are used to highlight some experimental results and understand the plasma conditions during these microsecond wire arrays implosions.

  11. Towards the System-on-Chip Realization of a Sensorless Vector Controller with Microsecond-order Computation Time

    OpenAIRE

    Beguenane, Rachid; Mailloux, Jean-Gabriel; Simard, Stephane; Tisserand, Arnaud

    2006-01-01

    International audience; The aim of this research is to implement sensorless vector control algorithms on a single, eventually reconfigurable, chip, with a computation timing constraint of, at most, 1-6 microseconds, and a concern for implementation cost. In this article, we discuss the implementation problems and tradeoffs involved in meeting these goals on Field-Programmable Gate Arrays (FPGAs). To be able to fit a complete induction motor vector controller on a single, inexpensive FPGA chip...

  12. Breaking The Millisecond Barrier On SpiNNaker: Implementing Asynchronous Event-Based Plastic Models With Microsecond Resolution

    Directory of Open Access Journals (Sweden)

    Xavier eLagorce

    2015-06-01

    Full Text Available Spike-based neuromorphic sensors such as retinas and cochleas, change the way in which the world is sampled. Instead of producing data sampled at a constant rate, these sensors output spikes that are asynchronous and event driven. The event-based nature of neuromorphic sensors implies a complete paradigm shift in current perception algorithms towards those that emphasize the importance of precise timing. The spikes produced by these sensors usually have a time resolution in the order of microseconds. This high temporal resolution is a crucial factor in learning tasks. It is also widely used in the field of biological neural networks. Sound localization for instance relies on detecting time lags between the two ears which, in the barn owl, reaches a temporal resolution of 5 microseconds. Current available neuromorphic computation platforms such as SpiNNaker often limit their users to a time resolution in the order of milliseconds that is not compatible with the asynchronous outputs of neuromorphic sensors. To overcome these limitations and allow for the exploration of new types of neuromorphic computing architectures, we introduce a novel software framework on the SpiNNaker platform. This framework allows for simulations of spiking networks and plasticity mechanisms using a completely asynchronous and event-based scheme running with a microsecond time resolution. Results on two example networks using this new implementation are presented.

  13. DREAMS-SIS: The Solar Irradiance Sensor on-board the ExoMars 2016 lander

    Science.gov (United States)

    Arruego, I.; Apéstigue, V.; Jiménez-Martín, J.; Martínez-Oter, J.; Álvarez-Ríos, F. J.; González-Guerrero, M.; Rivas, J.; Azcue, J.; Martín, I.; Toledo, D.; Gómez, L.; Jiménez-Michavila, M.; Yela, M.

    2017-07-01

    The Solar Irradiance Sensor (SIS) was part of the DREAMS (Dust characterization, Risk assessment, and Environment Analyzer on the Martian Surface) payload package on board the ExoMars 2016 Entry and Descent Module (EDM), "Schiaparelli". DREAMS was a meteorological station aimed at the measurement of several atmospheric parameters, as well as the presence of electric fields, during the surface operations of EDM. DREAMS-SIS is a highly miniaturized lightweight sensor designed for small meteorological stations, capable of estimating the aerosol optical depth (AOD) several times per sol, as well as performing a direct measurement of the global (direct plus scattered) irradiance on the Martian surface in the spectral range between 200 and 1100 nm. AOD is estimated from the irradiance measurements at two different spectral bands - Ultraviolet (UV) and near infrared (NIR) - which also enables color index (CI) analysis for the detection of clouds. Despite the failure in the landing of Schiaparelli, DREAMS-SIS is a valuable precursor for new developments being carried-on at present. The concept and design of DREAMS-SIS are here presented and its operating principles, supported by preliminary results from a short validation test, are described. Lessons learnt and future work towards a new generation of Sun irradiance sensors is also outlined.

  14. Time-of-Travel Methods for Measuring Optical Flow on Board a Micro Flying Robot

    Directory of Open Access Journals (Sweden)

    Erik Vanhoutte

    2017-03-01

    Full Text Available For use in autonomous micro air vehicles, visual sensors must not only be small, lightweight and insensitive to light variations; on-board autopilots also require fast and accurate optical flow measurements over a wide range of speeds. Using an auto-adaptive bio-inspired Michaelis–Menten Auto-adaptive Pixel (M 2 APix analog silicon retina, in this article, we present comparative tests of two optical flow calculation algorithms operating under lighting conditions from 6 × 10 − 7 to 1 . 6 × 10 − 2 W·cm − 2 (i.e., from 0.2 to 12,000 lux for human vision. Contrast “time of travel” between two adjacent light-sensitive pixels was determined by thresholding and by cross-correlating the two pixels’ signals, with measurement frequency up to 5 kHz for the 10 local motion sensors of the M 2 APix sensor. While both algorithms adequately measured optical flow between 25 ∘ /s and 1000 ∘ /s, thresholding gave rise to a lower precision, especially due to a larger number of outliers at higher speeds. Compared to thresholding, cross-correlation also allowed for a higher rate of optical flow output (99 Hz and 1195 Hz, respectively but required substantially more computational resources.

  15. Hall Thruster Plume Measurements On-Board the Russian Express Satellites

    Science.gov (United States)

    Manzella, David; Jankovsky, Robert; Elliott, Frederick; Mikellides, Ioannis; Jongeward, Gary; Allen, Doug

    2001-01-01

    The operation of North-South and East-West station-keeping Hall thruster propulsion systems on-board two Russian Express-A geosynchronous communication satellites were investigated through a collaborative effort with the manufacturer of the spacecraft. Over 435 firings of 16 different thrusters with a cumulative run time of over 550 hr were reported with no thruster failures. Momentum transfer due to plume impingement was evaluated based on reductions in the effective thrust of the SPT-100 thrusters and induced disturbance torques determined based on attitude control system data and range data. Hall thruster plasma plume effects on the transmission of C-band and Ku-band communication signals were shown to be negligible. On-orbit ion current density measurements were made and subsequently compared to predictions and ground test data. Ion energy, total pressure, and electric field strength measurements were also measured on-orbit. The effect of Hall thruster operation on solar array performance over several months was investigated. A subset of these data is presented.

  16. New particle formation events measured on board the ATR-42 aircraft during the EUCAARI campaign

    Directory of Open Access Journals (Sweden)

    S. Crumeyrolle

    2010-07-01

    Full Text Available Aerosol properties were studied during an intensive airborne measurement campaign that took place at Rotterdam in Netherlands in May 2008 within the framework of the European Aerosol Cloud Climate and Air Quality Interactions project (EUCAARI. The objective of this study is to illustrate seven events of new particle formation (NPF observed with two Condensation Particle Counters (CPCs operated on board the ATR-42 research aircraft in airsectors around Rotterdam, and to provide information on the spatial extent of the new particle formation phenomenon based on 1-s resolution measurements of ultra-fine particle (in the size range 3–10 nm diameter, denoted N3-10 hereafter concentrations. The results show that particle production occurred under the influence of different air mass origins, at different day times and over the North Sea as well as over the continent. The number concentration of freshly nucleated particles (N3-10 varied between 5000 and 100 000 cm−3 within the boundary layer (BL. Furthermore the vertical extension for all nucleation events observed on the ATR-42 never exceeded the upper limit of the BL. The horizontal extent of N3-10 could not be delimited due to inflexible flight plans which could not be modified to accommodate real-time results. However, the NPF events were observed over geographically large areas; typically the horizontal extension was about 100 km and larger.

  17. On-Board Real-Time Optimization Control for Turbo-Fan Engine Life Extending

    Science.gov (United States)

    Zheng, Qiangang; Zhang, Haibo; Miao, Lizhen; Sun, Fengyong

    2017-11-01

    A real-time optimization control method is proposed to extend turbo-fan engine service life. This real-time optimization control is based on an on-board engine mode, which is devised by a MRR-LSSVR (multi-input multi-output recursive reduced least squares support vector regression method). To solve the optimization problem, a FSQP (feasible sequential quadratic programming) algorithm is utilized. The thermal mechanical fatigue is taken into account during the optimization process. Furthermore, to describe the engine life decaying, a thermal mechanical fatigue model of engine acceleration process is established. The optimization objective function not only contains the sub-item which can get fast response of the engine, but also concludes the sub-item of the total mechanical strain range which has positive relationship to engine fatigue life. Finally, the simulations of the conventional optimization control which just consider engine acceleration performance or the proposed optimization method have been conducted. The simulations demonstrate that the time of the two control methods from idle to 99.5 % of the maximum power are equal. However, the engine life using the proposed optimization method could be surprisingly increased by 36.17 % compared with that using conventional optimization control.

  18. Pulpal effects of enamel ablation with a microsecond pulsed lambda = 9.3-microm CO2 laser.

    Science.gov (United States)

    Staninec, Michal; Darling, Cynthia L; Goodis, Harold E; Pierre, Daniel; Cox, Darren P; Fan, Kenneth; Larson, Michael; Parisi, Renaldo; Hsu, Dennis; Manesh, Saman K; Ho, Chi; Hosseini, Mehran; Fried, Daniel

    2009-04-01

    In vitro studies have shown that CO2 lasers operating at the highly absorbed 9.3 and 9.6-microm wavelengths with a pulse duration in the range of 10-20-microsecond are well suited for the efficient ablation of enamel and dentin with minimal peripheral thermal damage. Even though these CO2 lasers are highly promising, they have yet to receive FDA approval. Clinical studies are necessary to determine if excessive heat deposition in the tooth may have any detrimental pulpal effects, particularly at higher ablative fluencies. The purpose of this study was to evaluate the pulpal safety of laser irradiation of tooth occlusal surfaces under the conditions required for small conservative preparations confined to enamel. Test subjects requiring removal of third molar teeth were recruited and teeth scheduled for extraction were irradiated using a pulsed CO2 laser at a wavelength of 9.3 microm operating at 25 or 50 Hz using a incident fluence of 20 J/cm(2) for a total of 3,000 laser pulses (36 J) for both rates with water cooling. Two control groups were used, one with no treatment and one with a small cut made with a conventional high-speed hand-piece. No anesthetic was used for any of the procedures and tooth vitality was evaluated prior to treatment by heat, cold and electrical testing. Short term effects were observed on teeth extracted within 72 hours after treatment and long term effects were observed on teeth extracted 90 days after treatment. The pulps of the teeth were fixed with formalin immediately after extraction and subjected to histological examination. Additionally, micro-thermocouple measurements were used to estimate the potential temperature rise in the pulp chamber of extracted teeth employing the same irradiation conditions used in vivo. Pulpal thermocouple measurements showed the internal temperature rise in the tooth was within safe limits, 3.3+/-1.4 degrees C without water cooling versus 1.7+/-1.6 degrees C with water-cooling, n = 25, PCO2 laser can

  19. Satellite on-board real-time SAR processor prototype

    Science.gov (United States)

    Bergeron, Alain; Doucet, Michel; Harnisch, Bernd; Suess, Martin; Marchese, Linda; Bourqui, Pascal; Desnoyers, Nicholas; Legros, Mathieu; Guillot, Ludovic; Mercier, Luc; Châteauneuf, François

    2017-11-01

    A Compact Real-Time Optronic SAR Processor has been successfully developed and tested up to a Technology Readiness Level of 4 (TRL4), the breadboard validation in a laboratory environment. SAR, or Synthetic Aperture Radar, is an active system allowing day and night imaging independent of the cloud coverage of the planet. The SAR raw data is a set of complex data for range and azimuth, which cannot be compressed. Specifically, for planetary missions and unmanned aerial vehicle (UAV) systems with limited communication data rates this is a clear disadvantage. SAR images are typically processed electronically applying dedicated Fourier transformations. This, however, can also be performed optically in real-time. Originally the first SAR images were optically processed. The optical Fourier processor architecture provides inherent parallel computing capabilities allowing real-time SAR data processing and thus the ability for compression and strongly reduced communication bandwidth requirements for the satellite. SAR signal return data are in general complex data. Both amplitude and phase must be combined optically in the SAR processor for each range and azimuth pixel. Amplitude and phase are generated by dedicated spatial light modulators and superimposed by an optical relay set-up. The spatial light modulators display the full complex raw data information over a two-dimensional format, one for the azimuth and one for the range. Since the entire signal history is displayed at once, the processor operates in parallel yielding real-time performances, i.e. without resulting bottleneck. Processing of both azimuth and range information is performed in a single pass. This paper focuses on the onboard capabilities of the compact optical SAR processor prototype that allows in-orbit processing of SAR images. Examples of processed ENVISAT ASAR images are presented. Various SAR processor parameters such as processing capabilities, image quality (point target analysis), weight and

  20. RELEC Mission: Relativistic Electron Precipitation and TLE study on-board small spacecraft

    Science.gov (United States)

    Svertilov, Sergey

    The main goal of RELEC mission is studying of magnetosphere relativistic electron precipitation and its acting on the upper Atmosphere as well as transient luminous events (TLE) observation in wide range of electromagnetic spectrum. The RELEC set of instruments includes two identical detectors of X- and gamma-rays of high temporal resolution and sensitivity (DRGE-1 & DRGE-2), three axe directed detectors of energetic electrons and protons DRGE-3, UV TLE imager MTEL, UV detector DUV, low-frequency analyser LFA, radio-frequency analyser RFA, module of electronics intended for commands and data collection BE. During the RELEC mission following experiments will be provided: - simultaneous observations of energetic electron & proton flux (energy range ~0.1-10.0 MeV and low-frequency (~0.1-10 kHz) electromagnetic wave field intensity variations with high temporal resolution (~1 ms); - fine time structure (~1 mcs) measurements of transient atmospheric events in UV, X- and gamma rays with a possibility of optical imaging with resolution of ~km in wide FOV; - measurements of electron flux pitch-angle distribution in dynamical range from ~0.1 up to 105 part/cm2s; - monitoring of charge and neutral background particles in different areas of near-Earth space. Now the all RELEC instruments are installed on-board small spacecraft manufactured by Lavochkin space corporation. The launch is scheduled on May, 2014 as by-pass mission with Meteor spacecraft. The RELEC mission orbit is planned to be quasi-circular solar-synchronous with about 700 km height. The total volume of transmitted data is about 1.2 Gbyte per day.

  1. Functional evaluation using multifocal electroretinogram after selective retina therapy with a microsecond-pulsed laser.

    Science.gov (United States)

    Kim, Hoon Dong; Han, Jung Woo; Ohn, Young-Hoon; Brinkmann, Ralf; Park, Tae Kwann

    2014-12-11

    To evaluate the changes of retinal function with multifocal electroretinogram (mfERG), and estimate the association between functional and structural changes after selective retina therapy (SRT) with microsecond-pulsed laser in comparison to continuous wave laser photocoagulation (cwPC). Selective retina therapy and cwPC were applied with 10 × 10 shots and 1/2 lesion-width on the retina in the right and left eyes of 20 healthy Chinchilla Bastard rabbits, respectively. Optical coherence tomography (OCT), fundus fluorescein angiography (FFA), and mfERG were performed before, and on days 1, 7, and 30 after both laser treatments. The mean ratios of amplitudes and implicit times of N1 and P1 from eight hexagons covering laser-treated retinal lesions/total retina were measured. Histology was obtained after killing three rabbits at each time period to observe the anatomic changes after both laser treatments. The mean ratios of amplitudes of N1 and P1 in SRT lesions did not change significantly for 30 days after laser treatment. Only subtle reductions of the mean ratios of N1 and P1 amplitudes on day 1, thereafter the amplitudes showed the trend to recover toward baseline values. Histology and OCT revealed temporary and reversible morphologic changes after SRT, which restored to normal within 1 month. However, the mean ratios of N1 amplitudes on days 7 and 30 (P = 0.010, P < 0.001, respectively), and P1 amplitudes on days 7 and 30 (P < 0.001, P < 0.001, respectively) declined significantly in cwPC lesions compared with baseline. Disorganization and atrophic changes were identified on histology and OCT after cwPC. The results suggest that SRT preserved retinal function as well as anatomical structure after treatment. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  2. Microsecond pulsed hydrogen/deuterium exchange of electrosprayed ubiquitin ions stored in a linear ion trap.

    Science.gov (United States)

    Rajabi, Khadijeh

    2015-02-07

    A pulse of D2O vapour on the order of microseconds is allowed to react with the +6 to +9 charge states of ubiquitin confined in a linear ion trap (LIT). Two envelopes of peaks are detected for the ions of ubiquitin, corresponding to the ions that exchange more quickly and more slowly. The deuterium uptake of the protonated sites on ubiquitin ions accounts for the ion population with the fast exchange. The hydrogen/deuterium exchange (HDX) kinetics of ubiquitin ions trapped in the LIT for 200 ms showed comparable structural transitions to those trapped for 300 ms. When ions are trapped for longer, i.e. up to 2000 ms, mainly the slow exchanging ion population is detected. In all experiments the +7 ions exchange the most, suggesting a short distance between the surface protonated sites and nearby charged sites, and concomitantly high accessibility of surface protonated sites towards D2O. The +6 ions are more compact than the +7 ions but have one fewer protonated site, therefore fewer surface availabilities for D2O attack. The data suggest that the +6 ions keep most of their solution-phase contacts intact while the hydrophobic core is slightly interrupted in the +7 ions, possibly due to the exposure of charged His68 that is normally buried in the hydrophobic pocket. The +8 and +9 ions have more protonated sites but are less compact than the +7 ions because of Coulombic repulsion, resulting in a larger distance between the protonated sites and the basic sites. The data indicate that the HDX mechanism of ions with the slower exchange corresponding to the second envelope of peaks is primarily governed via a relay mechanism. The results suggest that the pulsed HDX MS method is sampling a population of ubiquitin ions with a similar backbone fold to the solution.

  3. Instrument Control Unit for the EPD on board Solar Orbiter

    Science.gov (United States)

    Sánchez Prieto, S.; Prieto Mateo, M.; Rodríguez Polo; Gutiérrez Molina; Parra Espada, P.; da Silva Fariña, A.

    2013-05-01

    Undoubtedly, Solar Orbiter is the leading mission of the European Space Agency for studying the Sun in the current decade. Its elliptical orbit around the Sun, with a perihelion as low as 0.28 AU and with an increasing inclination of up to more than 25° with respect to the solar equator, makes it ideal for an in-situ environmental study. This study will provide the key to determine how does the Sun create and control the heliosphere, which is the main objective of this mission. One of the ten instruments that are part of the Solar Orbiter's payload is the Energetic Particle Detector (EPD). Its main objective is to measure the composition, timing and distribution functions of suprathermal and energetic particles. Scientific topics to be addressed include the sources, acceleration mechanisms, and transport processes of these particles. EPD is composed of four sensors (STEIN, EPT, HET and SIS), distributed along the spacecraft, and an Instrument Control Unit or ICU. The sensors are able to measure electrons in the energy range from 0.002 to 20 MeV, protons from 0.003 to 100 MeV and nucleons of He to Fe in the range of 0.008 to 200 MeV/n. The ICU is the sole interface with the spacecraft, providing control, communication and data processing to the sensors. Due to the strong reliability requirements associated to the ICU, special care has been taken in the hardware, software and mechanical designs. In this work the development status of the ICU, together with its hardware and software architectures, design decisions and tools are presented.

  4. Quality Assessment of DSMs Produced from UAV Flights Georeferenced with On-Board RTK Positioning

    Directory of Open Access Journals (Sweden)

    Gianfranco Forlani

    2018-02-01

    Full Text Available High-resolution Digital Surface Models (DSMs from unmanned aerial vehicles (UAVs imagery with accuracy better than 10 cm open new possibilities in geosciences and engineering. The accuracy of such DSMs depends on the number and distribution of ground control points (GCPs. Placing and measuring GCPs are often the most time-consuming on-site tasks in a UAV project. Safety or accessibility concerns may impede their proper placement, so either costlier techniques must be used, or a less accurate DSM is obtained. Photogrammetric blocks flown by drones with on-board receivers capable of RTK (real-time kinematic positioning do not need GCPs, as camera stations at exposure time can be determined with cm-level accuracy, and used to georeference the block and control its deformations. This paper presents an experimental investigation on the repeatability of DSM generation from several blocks acquired with a RTK-enabled drone, where differential corrections were sent from a local master station or a network of Continuously Operating Reference Stations (CORS. Four different flights for each RTK mode were executed over a test field, according to the same flight plan. DSM generation was performed with three block control configurations: GCP only, camera stations only, and with camera stations and one GCP. The results show that irrespective of the RTK mode, the first and third configurations provide the best DSM inner consistency. The average range of the elevation discrepancies among the DSMs in such cases is about 6 cm (2.5 GSD, ground sampling density for a 10-cm resolution DSM. Using camera stations only, the average range is almost twice as large (4.7 GSD. The average DSM accuracy, which was verified on checkpoints, turned out to be about 2.1 GSD with the first and third configurations, and 3.7 GSD with camera stations only.

  5. EUV high resolution imager on-board solar orbiter: optical design and detector performances

    Science.gov (United States)

    Halain, J. P.; Mazzoli, A.; Rochus, P.; Renotte, E.; Stockman, Y.; Berghmans, D.; BenMoussa, A.; Auchère, F.

    2017-11-01

    The EUV high resolution imager (HRI) channel of the Extreme Ultraviolet Imager (EUI) on-board Solar Orbiter will observe the solar atmospheric layers at 17.4 nm wavelength with a 200 km resolution. The HRI channel is based on a compact two mirrors off-axis design. The spectral selection is obtained by a multilayer coating deposited on the mirrors and by redundant Aluminum filters rejecting the visible and infrared light. The detector is a 2k x 2k array back-thinned silicon CMOS-APS with 10 μm pixel pitch, sensitive in the EUV wavelength range. Due to the instrument compactness and the constraints on the optical design, the channel performance is very sensitive to the manufacturing, alignments and settling errors. A trade-off between two optical layouts was therefore performed to select the final optical design and to improve the mirror mounts. The effect of diffraction by the filter mesh support and by the mirror diffusion has been included in the overall error budget. Manufacturing of mirror and mounts has started and will result in thermo-mechanical validation on the EUI instrument structural and thermal model (STM). Because of the limited channel entrance aperture and consequently the low input flux, the channel performance also relies on the detector EUV sensitivity, readout noise and dynamic range. Based on the characterization of a CMOS-APS back-side detector prototype, showing promising results, the EUI detector has been specified and is under development. These detectors will undergo a qualification program before being tested and integrated on the EUI instrument.

  6. A new on-board imaging treatment technique for palliative and emergency treatments in radiation oncology

    Energy Technology Data Exchange (ETDEWEB)

    Held, Mareike

    2016-03-23

    This dissertation focuses on the use of on-board imaging systems as the basis for treatment planning, presenting an additional application for on-board images. A clinical workflow is developed to simulate, plan, and deliver a simple radiation oncology treatment rapidly, using 3D patient scans. The work focuses on an on-line dose planning and delivery process based on on-board images entirely performed with the patient set up on the treatment couch of the linear accelerator. This potentially reduces the time between patient simulation and treatment to about 30 minutes. The basis for correct dose calculation is the accurate image gray scale to tissue density calibration. The gray scale, which is defined in CT Numbers, is dependent on the energy spectrum of the beam. Therefore, an understanding of the physics characteristics of each on-board system is required to evaluate the impact on image quality, especially regarding the underlying cause of image noise, contrast, and non-uniformity. Modern on-board imaging systems, including kV and megavoltage (MV) cone beam (CB) CT as well as MV CT, are characterized in terms of image quality and stability. A library of phantom and patient CT images is used to evaluate the dose calculation accuracy for the on-board images. The dose calculation objective is to stay within 5% local dose differences compared to standard kV CT dose planning. The objective is met in many treatment cases. However, dose calculation accuracy depends on the anatomical treatment site. While on-board CT-based treatments of the head and extremities are predictable within 5% on all systems, lung tissue and air cavities may create local dose discrepancies of more than 5%. The image quality varies between the tested units. Consequently, the CT number-to-density calibration is defined independently for each system. In case of some imaging systems, the CT numbers of the images are dependent on the protocol used for on-board imaging, which defines the imaging dose

  7. ATLID, the atmospheric lidar on board the Earthcare Satellite

    Science.gov (United States)

    Hélière, Arnaud; Gelsthorpe, Robert; Le Hors, Lénaïc.; Toulemont, Yves

    2017-11-01

    The EarthCARE mission is the sixth Earth Explorer Mission of the ESA Living Planet Programme, with a launch date planned in 2015. It addresses the interaction and impact of clouds and aerosols on the Earth's radiative budget. ATLID (ATmospheric LIDar), one of the four instruments of EarthCARE, shall determine vertical profiles of cloud and aerosol physical parameters (altitude, optical depth, backscatter ratio and depolarisation ratio) in synergy with other instruments. Operating in the UV range at 355 nm, ATLID provides atmospheric echoes with a vertical resolution of about 100 m from ground to an altitude of 40 km. As a result of high spectral resolution filtering, the lidar is able to separate the relative contribution of aerosol (Mie) and molecular (Rayleigh) scattering, which gives access to aerosol optical depth. The purpose of the paper is to present the progress in the instrument and subsystem design. The instrument is currently in phase C where the detailed design of all sub-systems is being performed. Emphasis will be put on the major technological developments, in particular the laser Transmitter, the optical units and detector developments.

  8. The ART-XC Instrument on Board the SRG Mission

    Science.gov (United States)

    Pavlinksy, M.; Akimov, V.; Levin, V.; Lapshov, I.; Tkachenko, A.; Semena, N.; Buntov, M.; Glushenko, A.; Arefiev, V.; Yaskovish, A.; hide

    2012-01-01

    Spectrum Roentgen Gamma (SRG) is an X-ray astrophysical observatory, developed by Russia in collaboration with Germany. The mission will be launched in 2014 from Baikonur, by a Zenit rocket with a Fregat booster and placed in a 6-month-period halo orbit around L2. The scientific payload consists of two independent telescopes . a soft-x-ray survey instrument, eROSITA, being provided by Germany and a medium-x-ray-energy survey instrument ART-XC being developed by Russia. ART-XC will consist of seven independent, but co-aligned, telescope modules with seven corresponding cadmium-telluride focal plane detectors. Each will operate over the approximate energy range of 6- 30 keV, with an angular resolution of <1 ', a field of view of 30 ' and an energy resolution about 10% at 14 keV. The NASA Marshall Space Flight Center (MSFC) will fabricate some of the mirror modules, to complement others fabricated by VNIIEF in Russia.

  9. The Altcriss project on board the International Space Station

    Science.gov (United States)

    Casolino, M.; Minori, M.; Picozza, P.; Fuglesang, C.; Galper, A.; Popov, A.; Benghin, V.; Petrov, V.M.; Nagamatsu, A.; Berger, T.; Reitz, G.; Durante, M.; Pugliese, M.; Roca, V.; Sihver, L.; Cucinotta, F.; Semones, E.; Shavers, M.; Guarnieri, V.; Lobascio, C.; Castagnolo, D.; Fortezza, R.

    The Altcriss project aims perform long term measurement of the radiation environment in different points of the International Space Station. To achieve this goal, it employs an active silicon detector, Sileye-3/Alteino, to monitor nuclei up to Iron in the energy range above 40 MeV/n. Both long term modulation of galactic cosmic rays going toward solar minimum and solar particles events will be observed. A number of different dosimeters are being employed to measure the dose and compare it with the silicon detector data. Another aim of the project is to monitor the effectiveness of shielding materials in orbit: a set of polyethylene tiles is placed in the detector acceptance window and particle flux and composition is compared with measurements in the same locations without shielding. Dosimeters are thus placed behind the shielding material and in an unshielded location to cross-correlate this information. The observation campaign begun in December 2005 and is running continuously ever since. Active and passive data have been retreived at the end of expedition 13, 14 and Astrolab mission. In this work we will describe the experiment and the preliminary results.

  10. Research Opportunities on board Virgin Galactic's SpaceShipTwo

    Science.gov (United States)

    Attenborough, S.; Pomerantz, W.; Stephens, K.

    2013-09-01

    Virgin Galactic is building the world's first commercial spaceline. Our suborbital spaceflight system, pictured in Figure 1, consists of two vehicles: WhiteKnightTwo (WK2) and SpaceShipTwo (SS2). WhiteKnightTwo is a four-engine, dual-fuselage jet aircraft capable of high-altitude heavy lift missions, including, but not limited to fulfilling its role as a mothership for SpaceShipTwo, an air-launched, suborbital spaceplane capable of routinely reaching an apogee up to 110 kilometers. In conjunction, these two vehicles allow access to space and to regions of the atmosphere ranging from the troposphere to the thermosphere; additionally, they provide extended periods of microgravity in a reliable and affordable way. SpaceShipTwo, with a payload capacity of up to 1,300 lbs. (~600 kg), features payload mounting interfaces that are compatible with standard architectures such as NASA Space Shuttle Middeck Lockers, Cargo Transfer Bags, and server racks, in addition to custom structures. With the standard interface, payloads are allowed access to the large 17 inch diameter cabin windows for external observations. Each dedicated research flight will be accompanied by a Virgin Galactic Flight Test Engineer, providing an opportunity for limited in-flight interaction. In addition, tended payloads - a flight that includes the researcher and his or her payload - are also an option. At a price point that is highly competitive with parabolic aircraft and sounding rockets and significantly cheaper than orbital flights, SpaceShipTwo is a unique platform that can provide frequent and repeatable research opportunities. Suborbital flights on SpaceShipTwo offer researchers several minutes of microgravity time and views of the external environment in the upper atmosphere and in outer space. In addition to serving as an important research platform in and of itself, SpaceShipTwo also offers researchers a means to test, iterate, and calibrate experiments designed for orbital platforms

  11. STROBE-X: X-Ray Timing Spectroscopy on Dynamical Timescales from Microseconds to Years

    Science.gov (United States)

    Wilson-Hodge, Colleen A.; Ray, P. S.; Gendreau, K.; Arzoumanian, Z.; Chakrabarty, D.; Remillard, R.; Feroci, M.; Maccarone, T.; Wood, K.; Jenke, P.

    2017-01-01

    We describe a probe-class mission concept that provides an unprecedented view of the X-ray sky, performing timing and 0.2-30 keV spectroscopy over timescales from microseconds to years. The Spectroscopic Time-Resolving Observatory for Broadband Energy X-rays (STROBE-X) comprises three primary instruments. The first uses an array of lightweight optics (3-m focal length) that concentrate incident photons onto solid state detectors with CCD-level (85-130 eV) energy resolution, 100 ns time resolution, and low background rates to cover the 0.2-12 keV band. This technology is scaled up from NICER, with enhanced optics to take advantage of the longer focal length of STROBE-X. The second uses large-area collimated silicon drift detectors, developed for ESA's LOFT, to cover the 2-30 keV band. These two instruments each provide an order of magnitude improvement in effective area compared with its predecessor (NICER and RXTE, respectively). Finally, a sensitive sky monitor triggers pointed observations, provides high duty cycle, high time resolution, high spectral resolution monitoring of the X-ray sky with approx. 20 times the sensitivity of the RXTE ASM, and enables multi-wavelength and multi-messenger studies on a continuous, rather than scanning basis.For the first time, the broad coverage provides simultaneous study of thermal components, non-thermal components, iron lines, and reflection features from a single platform for accreting black holes at all scales. The enormous collecting area allows detailed studies of the dense matter equation of state using both thermal emission from rotation-powered pulsars and harder emission from X-ray burst oscillations. The combination of the wide-field monitor and the sensitive pointed instruments enables observations of potential electromagnetic counterparts to LIGO and neutrino events. Additional extragalactic science, such as high quality spectroscopy of clusters of galaxies and unprecedented timing investigations of active

  12. STROBE-X: X-ray Timing & Spectroscopy on Dynamical Timescales from Microseconds to Years

    Science.gov (United States)

    Wilson-Hodge, Colleen A.; Ray, Paul S.; Maccarone, Thomas J.; Chakrabarty, Deepto; Gendreau, Keith C.; Arzoumanian, Zaven; Jenke, Peter; Ballantyne, David; Bozzo, Enrico; Brandt, Soren; Brenneman, Laura; Christophersen, Marc; DeRosa, Alessandra; Feroci, Marco; Goldstein, Adam; Hartmann, Dieter; Hernanz, Margarita; McDonald, Michael; Phlips, Bernard; Remillard, Ronald; Stevens, Abigail; Tomsick, John; Watts, Anna; Wood, Kent S.; Zane, Silvia; STROBE-X Collaboration

    2018-01-01

    We describe a probe-class mission concept that provides an unprecedented view of the X-ray sky, performing timing and 0.2-30 keV spectroscopy over timescales from microseconds to years. The Spectroscopic Time-Resolving Observatory for Broadband Energy X-rays (STROBE-X) comprises three primary instruments. The first uses an array of lightweight optics (3-m focal length) that concentrate incident photons onto solid state detectors with CCD-level (85-130 eV) energy resolution, 100 ns time resolution, and low background rates to cover the 0.2-12 keV band. This technology is scaled up from NICER, with enhanced optics to take advantage of the longer focal length of STROBE-X. The second uses large-area collimated silicon drift detectors, developed for ESA's LOFT, to cover the 2-30 keV band. These two instruments each provide an order of magnitude improvement in effective area compared with its predecessor (NICER and RXTE, respectively). Finally, a sensitive sky monitor triggers pointed observations, provides high duty cycle, high time resolution, high spectral resolution monitoring of the X-ray sky with ~20 times the sensitivity of the RXTE ASM, and enables multi-wavelength and multi-messenger studies on a continuous, rather than scanning basis. We include updated instrument designs resulting from the GSFC IDL run in November 2017.For the first time, the broad coverage provides simultaneous study of thermal components, non-thermal components, iron lines, and reflection features from a single platform for accreting black holes at all scales. The enormous collecting area allows detailed studies of the dense matter equation of state using both thermal emission from rotation-powered pulsars and harder emission from X-ray burst oscillations. The combination of the wide-field monitor and the sensitive pointed instruments enables observations of potential electromagnetic counterparts to LIGO/Virgo and neutrino events. Extragalactic science, such as constraining bulk metalicity

  13. On-Board Entry Trajectory Planning Expanded to Sub-orbital Flight

    Science.gov (United States)

    Lu, Ping; Shen, Zuojun

    2003-01-01

    A methodology for on-board planning of sub-orbital entry trajectories is developed. The algorithm is able to generate in a time frame consistent with on-board environment a three-degree-of-freedom (3DOF) feasible entry trajectory, given the boundary conditions and vehicle modeling. This trajectory is then tracked by feedback guidance laws which issue guidance commands. The current trajectory planning algorithm complements the recently developed method for on-board 3DOF entry trajectory generation for orbital missions, and provides full-envelope autonomous adaptive entry guidance capability. The algorithm is validated and verified by extensive high fidelity simulations using a sub-orbital reusable launch vehicle model and difficult mission scenarios including failures and aborts.

  14. On-board diagnostics of fully variable valve actuator systems in spark-ignited combustion engines

    Energy Technology Data Exchange (ETDEWEB)

    Sarac, Ipek

    2010-07-01

    Variable valve actuation (VVA) is being employed in contemporary engines to improve fuel consumption, torque characteristics and emissions of combustion engines by enabling the realization of different combustion strategies. Fully variable valve actuation (FVVA) makes it possible to apply a wider range of strategies (e.g., homogenous charge compression ignition (HCCI), dethrottling, internal residual gas mechanism, 2/4 Stroke Switching). With FVVA, the gas exchange valves can be actuated at arbitrary points in time, with separate variable lifting for the intake and exhaust valves of each cylinder. Making FVVA systems ready for the market requires to provide the system with appropriate fault-diagnostic functionality. Additional degrees of freedom of FVVA systems introduce different fault cases which have to be considered in terms of their emission relevance within the scope of diagnostics standards such as On-Board Diagnosis II (OBD II). The faults and their effects on emissions have not been analyzed by any other study, yet. To fill this gab, here the possible faults are generated using a four-cylinder gasoline camless test bench engine. Measurements are carried out using different strategies at low loads, namely dethrottling with early intake valve closing and combining high internal residual gas with dethrottling. Each fault case is thoroughly analyzed, and the emission-relevant faults are pointed out for initial consideration. A trivial approach to diagnose fully variable valve actuators is to introduce position sensors for each actuator to track the valve lift curve. However, this approach increases the cost of the system undesirably. Thus, here alternative methods are explored such as indirect use of common powertrain sensors. Considering that active diagnosis may lead to suboptimal engine control schemes, the possibilities of fault detection and isolation are investigated without relying on active diagnosis. Air path sensors are affected foremost by any

  15. TECHNICAL MAINTENANCE EFFICIENCY OF THE AIRCRAFT MAINTENANCE-FREE ON-BOARD SYSTEM BETWEEN SCHEDULED MAINTENANCES

    Directory of Open Access Journals (Sweden)

    A. M. Bronnikov

    2017-01-01

    Full Text Available The avionics concept of the maintenance-free on-board equipment implies the absence of necessity to maintain onboard systems between scheduled maintenance, preserving the required operational and technical characteristics; it should be achieved by automatic diagnosis of the technical condition and the application of active means of ensuring a failsafe design, allowing to change the structure of the system to maintain its functions in case of failure. It is supposed that such equipment will reduce substantially and in the limit eliminate traditional maintenance of aircraft between scheduled maintenance, ensuring maximum readiness for use, along with improving safety. The paper proposes a methodology for evaluating the efficiency of maintenance-free between scheduled maintenance aircraft system with homogeneous redundancy. The excessive redundant elements allow the system to accumulate failures which are repaired during the routine maintenance. If the number of failures of any reserve is approaching a critical value, the recovery of the on-board system (elimination of all failures is carried out between scheduled maintenance by conducting rescue and recovery operations. It is believed that service work leads to the elimination of all failures and completely updates the on-board system. The process of system operational status changes is described with the discrete-continuous model in the flight time. The average losses in the sorties and the average cost of operation are used as integrated efficiency indicators of system operation. For example, the evaluation of the operation efficiency of formalized on-board system with homogeneous redundancy demonstrates the efficiency of the proposed methodology and the possibility of its use while analyzing the efficiency of the maintenance-free operation equipment between scheduled periods. As well as a comparative analysis of maintenance-free operation efficiency of the on-board system with excessive

  16. Recommendations for assessing water quality and safety on board merchant ships.

    Science.gov (United States)

    Grappasonni, Iolanda; Cocchioni, Mario; Degli Angioli, Rolando; Saturnino, Andrea; Sibilio, Fabio; Scuri, Stefania; Amenta, Francesco

    2013-01-01

    Health and diseases on board ships may depend on water. Interventions to improve the quality of water may bring to significant benefits to health and water stores/supply and should be controlledto protect health. This paper has reviewed the main regulations for the control of water safety and qualityon board ships and presents some practical recommendations for keeping water healthy and safe in passenger and cargo merchant ships. The main international regulations and guidelines on the topic were analysed. Guidelines forWater Quality on Board Merchant Ships Including Passenger Vessels of Health Protection Agency, World Health Organisation (WHO) Guide to Ship Sanitation, WHO Guidelines for Drinking Water Quality, WHO Water Safety Plan and the United States Center for Disease Control and Prevention Vessel Sanitation Program were examined. Recommendations for passenger and, if available, for cargo ships were collected and compared. Recommended questionnaire: A questionnaire summarising the main information to collect for assessingthe enough quality of water for the purposes it should be used on board is proposed. The need of havinga crew member with water assessment duties on board, trained for performing these activities properlyis discussed. Water quality on board ships should be monitored routinely. Monitoring should be directedto chemical and microbiological parameters for identifying possible contamination sources, using specifickits by a designed crew member. More detailed periodic assessments should be under the responsibility ofspecialised personnel/laboratories and should be based on sample collection from all tanks and sites of waterdistribution. It is important to select a properly trained crew member on board for monitoring water quality.

  17. On-board digital signal processing technologies for present and future SCPC systems

    Science.gov (United States)

    Kato, Shuzo; Ohtani, Kohichi; Kohri, Takehru; Morikura, Masahiro; Umehira, Masahiro

    1988-09-01

    This paper surveys trends in digital and analog ICs and LSICs, including radiation hardness performance. An optimal selection of devices and suitable architectures for SCPC multicarrier demodulators is discussed. The results show good and clear guidelines for device and architecture selection for on-board signal processing at the present time and toward the year 2000. It is shown that, for on-board SCPC multicarrier demodulation, a transmultiplexer type channel divider and digital common demodulator has a good performance with a medium number of channels for regeneration.

  18. Sub microsecond notching of a negative hydrogen beam at low energy utilizing a magnetron ion source with a split extractor

    Energy Technology Data Exchange (ETDEWEB)

    Moehs, Douglas; /Fermilab

    2004-12-01

    A technique for sub-microsecond beam notching is being developed at 20 keV utilizing a Magnetron ion source with a slit extraction system and a split extractor. Each half of the extractor is treated as part of a 50 ohm transmission line which can be pulsed at {+-}700 volts creating a 1400 volt gradient. This system along with the associated electronics is electrically floated on top of a pulsed extraction voltage. A beam reduction of 95% has been observed at the end of the Fermilab 400 MeV Linac and 35% notching has recently been achieved in the Booster.

  19. [High current microsecond pulsed hollow cathode lamp excited ionic fluorescence spectrometry of alkaline earth elements in inductively coupled plasma with a Fassel-torch].

    Science.gov (United States)

    Zhang, Shao-Yu; Gong, Zhen-Bin; Huang, Ben-Li

    2006-02-01

    High current microsecond pulsed hollow cathode lamp (HCMP-HCL) excited ionic fluorescence spectrometry (IFS) of alkaline earth elements in inductively coupled plasma (ICP) with a Fassel-torch has been investigated. In wide condition ranges only IFS was observed, whilst atomic fluorescence spectrometry (AFS) was not detectable. More intense ionic fluorescence signal was observed at lower observation heights and at lower incident RF powers. Without introduction of any reduction organic gases into the ICP, the limit of detection (LOD, 3sigma) of Ba was improved by 50-fold over that of a conventional pulsed (CP) HCL with the Baird sleeve-extended torch. For Ca and Sr, the LODs by HCMP-HCL-ICP-IFS and CP-HCL-ICP-AFS show no significant difference. Relative standard deviations were 0.6%-1.4% (0.1-0.2 microg x mL(-1), n = 10) for 5 ionic fluorescence lines. Preliminary studies showed that the intensity of ionic fluorescence could be depressed in the presence of K, Al and P.

  20. Sub-microsecond x-ray imaging using hole-collecting Schottky type CdTe with charge-integrating pixel array detectors

    Science.gov (United States)

    Becker, J.; Tate, M. W.; Shanks, K. S.; Philipp, H. T.; Weiss, J. T.; Purohit, P.; Chamberlain, D.; Gruner, S. M.

    2017-06-01

    CdTe is increasingly being used as the x-ray sensing material in imaging pixel array detectors for x-rays, generally above 20 keV, where silicon sensors become unacceptably transparent. Unfortunately CdTe suffers from polarization, which can alter the response of the material over time and with accumulated dose. Most prior studies used long integration times or CdTe that was not of the hole-collecting Schottky type. We investigated the temporal response of hole-collecting Schottky type CdTe sensors on timescales ranging from tens of nanoseconds to several seconds. We found that the material shows signal persistence on the timescale of hundreds of milliseconds attributed to the detrapping of a shallow trap, and additional persistence on sub-microsecond timescales after polarization. The results show that this type of CdTe can be used for time resolved studies down to approximately 100 ns. However quantitative interpretation of the signal requires careful attention to bias voltages, polarization and exposure history.

  1. Energy management systems on board of electric vehicles, based on power electronics

    Energy Technology Data Exchange (ETDEWEB)

    Guidi, Giuseppe

    2009-03-15

    The core of any electric vehicle (EV) is the electric drive train, intended as the energy conversion chain from the energy tank (typically some kind of rechargeable battery) to the electric motor that converts the electrical energy into the mechanical energy needed for the vehicle motion. The need for on-board electrical energy storage is the factor that has so far prevented pure electric vehicles from conquering significant market share. In fact electrochemical batteries, which are currently the most suitable device for electrical energy storage, have serious limitations in terms of energy and/or power density, cost and safety. All those characteristics reflect in pure electric vehicles being outperformed by standard internal combustion engine (ICE) based vehicles in terms of driving range, time needed to refuel and purchase cost. Electric vehicles do have their distinctive advantages, being intrinsically much more efficient, operating at zero emissions at the pipe, and offering a higher degree of controllability that can potentially enhance driving safety. No wonder then, that electric energy storage technology has attracted considerable R&D investments, resulting in new traction battery packs that are getting closer and closer to the industrial targets. In this scenario of EV technology gaining momentum, power electronics engineers have to come up with newer solutions allowing for more efficient and more reliable utilization of the precious on-board energy that comes in a form that cannot be directly utilized by the motor. At present, most of the research in the area of power electronics for automotive is focused in volume and cost reduction techniques. The increase in power density is pursued by developing components that can be operated at higher temperature, thus relieving the requirements on cooling. In this thesis, the focus is on the development of alternative topologies for the power electronics converters that make use of some peculiarities of the energy

  2. Mapping the space radiation environment in LEO orbit by the SATRAM Timepix payload on board the Proba-V satellite

    Energy Technology Data Exchange (ETDEWEB)

    Granja, Carlos, E-mail: carlos.granja@utef.cvut.cz; Polansky, Stepan

    2016-07-07

    Detailed spatial- and time-correlated maps of the space radiation environment in Low Earth Orbit (LEO) are produced by the spacecraft payload SATRAM operating in open space on board the Proba-V satellite from the European Space Agency (ESA). Equipped with the hybrid semiconductor pixel detector Timepix, the compact radiation monitor payload provides the composition and spectral characterization of the mixed radiation field with quantum-counting and imaging dosimetry sensitivity, energetic charged particle tracking, directionality and energy loss response in wide dynamic range in terms of particle types, dose rates and particle fluxes. With a polar orbit (sun synchronous, 98° inclination) at the altitude of 820 km the payload samples the space radiation field at LEO covering basically the whole planet. First results of long-period data evaluation in the form of time-and spatially-correlated maps of total dose rate (all particles) are given.

  3. On-board conversion of methanol to dimethyl ether as an alternative diesel fuel

    Energy Technology Data Exchange (ETDEWEB)

    Armbruster, H.; Heinzelmann, G.; Struis, R.; Stucki, S. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The catalytic dehydration of methanol to dimethyl ether was investigated for application on-board a methanol fuelled vehicle. Several catalysts have been tested in a fixed bed reactor. Our approach is to develop a small and efficient reactor converting liquid MeOH under pressure and at low reaction temperatures. (author) 2 figs., 5 refs.

  4. Spacecube: A Family of Reconfigurable Hybrid On-Board Science Data Processors

    Science.gov (United States)

    Flatley, Thomas P.

    2015-01-01

    SpaceCube is a family of Field Programmable Gate Array (FPGA) based on-board science data processing systems developed at the NASA Goddard Space Flight Center (GSFC). The goal of the SpaceCube program is to provide 10x to 100x improvements in on-board computing power while lowering relative power consumption and cost. SpaceCube is based on the Xilinx Virtex family of FPGAs, which include processor, FPGA logic and digital signal processing (DSP) resources. These processing elements are leveraged to produce a hybrid science data processing platform that accelerates the execution of algorithms by distributing computational functions to the most suitable elements. This approach enables the implementation of complex on-board functions that were previously limited to ground based systems, such as on-board product generation, data reduction, calibration, classification, eventfeature detection, data mining and real-time autonomous operations. The system is fully reconfigurable in flight, including data parameters, software and FPGA logic, through either ground commanding or autonomously in response to detected eventsfeatures in the instrument data stream.

  5. Survivability of chilled water networks on board ships when using dincs

    NARCIS (Netherlands)

    Smit, C.S.

    2012-01-01

    Fast reaction is required when a chilled water distribution network on board a naval ship is damaged. Without immediate isolation of the leakage area, all water supply is lost soon, with immense consequences for the ship’s operational state. The only solution for that is using an automated recovery

  6. On-board Model Predictive Control of a Quadrotor Helicopter: Design, Implementation, and Experiments

    Science.gov (United States)

    2012-12-13

    Camera 1r Camera 12r ESC 1S ESC 4S WiFi APiFi ... On-board Quadrotor ... motors Figure A.1: High-level system diagram showing the main components...a dangerous prospect to say the least. We are thus testing a remote “kill switch” we have developed which incorporates a watchdog principle: A

  7. How to choose the best embedded processing platform for on-board UAV image processing ?

    OpenAIRE

    Hulens, Dries; Goedemé, Toon; Verbeke, Jon

    2015-01-01

    Hulens D., Goedemé T., Verbeke J., ''How to choose the best embedded processing platform for on-board UAV image processing ?'', Proceedings 10th international conference on computer vision theory and applications - VISAPP 2015, 10 pp., March 11-14, 2015, Berlin, Germany.

  8. 77 FR 7562 - Electronic On-Board Recorders and Hours of Service Supporting Documents

    Science.gov (United States)

    2012-02-13

    ...-Board Recorders and Hours of Service Supporting Documents AGENCY: Federal Motor Carrier Safety... the Electronic On-Board Recorders and Hours of Service Supporting Documents rulemaking (EOBR 2) by... regarding harassment issues. ADDRESSES: Comments and material received from the public as well as documents...

  9. 77 FR 54651 - Study on the Use of Cell Phones On Board Aircraft

    Science.gov (United States)

    2012-09-05

    ... Cell Phones On Board Aircraft AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of...) directed the Administrator of the FAA to conduct a study on the impact of the use of cell phones for voice... Cell Phone Study Comments using any of the following methods: E-Mail: Send comments to CELLPHONEcomment...

  10. Increase in construction machine efficiency by improvement of on-board diagnostics of its hydraulic drive

    OpenAIRE

    Pimonov, I.; Novik, I

    2007-01-01

    On-board diagnostics with measuring of the determining parameter in "one point" of the hydraulic drive, together with the ball-type distributor component of the hydraulic tester, allows less equipment to be built in the hydraulic drive, excludes additional pressure losses caused by the presence of any diagnostic equipment inside the drive, ensures higher operational reliability and efficiency of the diagnostic equipment.

  11. Lifestyle factors in Croatian seafarers as relating to health and stress on board.

    Science.gov (United States)

    Slišković, Ana; Penezić, Zvjezdan

    2017-01-01

    Seafaring is characterized by specific stressors and health risks. The purpose of this article was to compare the prevalence of various lifestyle factors between the shipping and home environments, and in addition to test the relations between lifestyle factors, perceived stress on board, and health in seafarers. A total of 530 Croatian seafarers participated in an on-line survey. The questionnaire contained requests for demographic data and a set of questions relating to lifestyle, stress on board, physical health symptoms, and mental health. The data showed higher sleep deprivation, higher levels of smoking and unhealthier diet at sea than at home, with prevalence of alcohol consumption and physical exercise being more favourable for the shipping environment. Sleep deprivation, unhealthy diet, lack of physical exercise, and smoking are shown as negative correlates of various measures of health. Stress on board was associated with sleep deprivation and unhealthy diet, and with more unfavourable physical and mental health. The results give practical implications for promoting health in seafarers. Some of the lifestyle factors tested, such as alcohol use, smoking and physical exercise, fall rather under individual control, but others, such as a healthy, balanced diet on board and sleeping hygiene at sea, should be improved by shipping management.

  12. Heavy fall of migrating land-birds on board of a ship off Central America

    NARCIS (Netherlands)

    Roselaar, C.S.

    1976-01-01

    Between 4 and 7 October 1973, during a spell of unfavourable weather, 85 North American migratory birds were found dead on board a ship sailing between Costa Rica and Belize and in the roads of Belize. They were donated to the Institute of Taxonomic Zoology, University of Amsterdam, where they were

  13. ROI-Based On-Board Compression for Hyperspectral Remote Sensing Images on GPU.

    Science.gov (United States)

    Giordano, Rossella; Guccione, Pietro

    2017-05-19

    In recent years, hyperspectral sensors for Earth remote sensing have become very popular. Such systems are able to provide the user with images having both spectral and spatial information. The current hyperspectral spaceborne sensors are able to capture large areas with increased spatial and spectral resolution. For this reason, the volume of acquired data needs to be reduced on board in order to avoid a low orbital duty cycle due to limited storage space. Recently, literature has focused the attention on efficient ways for on-board data compression. This topic is a challenging task due to the difficult environment (outer space) and due to the limited time, power and computing resources. Often, the hardware properties of Graphic Processing Units (GPU) have been adopted to reduce the processing time using parallel computing. The current work proposes a framework for on-board operation on a GPU, using NVIDIA's CUDA (Compute Unified Device Architecture) architecture. The algorithm aims at performing on-board compression using the target's related strategy. In detail, the main operations are: the automatic recognition of land cover types or detection of events in near real time in regions of interest (this is a user related choice) with an unsupervised classifier; the compression of specific regions with space-variant different bit rates including Principal Component Analysis (PCA), wavelet and arithmetic coding; and data volume management to the Ground Station. Experiments are provided using a real dataset taken from an AVIRIS (Airborne Visible/Infrared Imaging Spectrometer) airborne sensor in a harbor area.

  14. On-Board File Management and Its Application in Flight Operations

    Science.gov (United States)

    Kuo, N.

    1998-01-01

    In this paper, the author presents the minimum functions required for an on-board file management system. We explore file manipulation processes and demonstrate how the file transfer along with the file management system will be utilized to support flight operations and data delivery.

  15. Sub-microsecond vapor plume dynamics under different keyhole penetration regimes in deep penetration laser welding

    Science.gov (United States)

    Chen, Xin; Pang, Shengyong; Shao, Xinyu; Wang, Chunming; Zhang, Xiaosi; Jiang, Ping; Xiao, Jianzhong

    2017-05-01

    It is well-known that distinct vapor plume dynamics occur during deep penetration laser welding under different keyhole penetration states. However, there is little knowledge about the physical characteristics of vapor plumes (velocity, pressure, flow patterns, etc) located inside transient keyholes of varying penetration regimes in laser welding. This lack of knowledge is primarily because mesoscale vapor plumes are highly dynamic and generally invisible. Based on a well-tested three-dimensional multiphase laser welding model, we conducted a computational study on vapor plume dynamics inside transient keyholes during the fiber laser welding of 304 austenite stainless steel as a function of keyhole penetration regimes. We observed three keyhole regimes of penetration: full penetration, partial penetration and no penetration. We then physically analyzed the vapor plumes in these regimes. We determined that the vapor plume velocities and pressures in all three regimes were uneven and oscillated following the dynamic keyhole with a characteristic timescale in sub-microseconds. Only when the keyhole approached the full penetration regime did vapor plumes begin to violently eject from the bottom of the keyhole opening, whereas in the partial penetration regime, even when the bottom part of the keyhole was open, most of the vapor plume ejected from the upper keyhole opening. This latter observation was similar to that in the no penetration mode. We studied the physical mechanism of this behavior by analyzing the keyhole temperature and vapor plume velocity distributions. We determined that the upward ejection of the vapor plume from the upper keyhole opening was the result of an uneven micro-meter scale boiling phenomenon of the transient keyhole governed by Fresnel absorptions dependent on the local inclination angle of the keyhole wall. Similarly, we determined that the ejection of the vapor plume from the bottom of the keyhole opening resulted from pressure

  16. MICROBIOLOGICAL EFFECTS OF ON-BOARD FISHING VESSEL HANDLING IN MERLUCCIUS MERLUCCIUS

    Directory of Open Access Journals (Sweden)

    P. Serratore

    2011-01-01

    Full Text Available The purpose of the present study was to determine the impact of different manipulation techniques applied on board fishing vessel, on the microbiological quality of the flesh of European hake (Merluccius merluccius during storage at +3°C ± 1°C for a time (T of 10 days after landing (T1-T10. Samples of fish were taken from a fishing vessel of the Adriatic Sea and from one of the Tyrrhenian Sea, treated on-board under different icing conditions: 1 a low ice/product weight ratio and 2 an optimal ice/product weight ratio, up to 1:3 (3. Spoilage bacteria as Total Bacterial Count (TBC and specific spoilage bacteria as Sulphide Producing Bacteria (SPB were enumerated in fish flesh as Colony Forming Units (CFU/g on Plate Count Agar and Lyngby Agar at 20°C for 3-5 days. TBC of the Adriatic fishes (gutted on-board resulted 103 UFC/g at T1-T6, and 104-105 at T10, whereas TBC of the Tyrrhenian fishes (not gutted on-board resulted 10-102 UFC/g at T2- T3, 103 at T6, and 104-105 at T10. SPB resulted 10- 102 UFC/g at T1-T6, and 103- 104 at T10, with absolute values higher in the Adriatic fishes, in respect with the Tyrrhenian fishes, and in the low icing conditions in respect with the optimal icing condition. At the experimented condition, the lowering of the microbiological quality of fish flesh during storage, seems to be more dependent on the gutting versus not gutting on-board practice rather than on the low versus optimal icing treatment.

  17. On-Board Fiber-Optic Network Architectures for Radar and Avionics Signal Distribution

    Science.gov (United States)

    Alam, Mohammad F.; Atiquzzaman, Mohammed; Duncan, Bradley B.; Nguyen, Hung; Kunath, Richard

    2000-01-01

    Continued progress in both civil and military avionics applications is overstressing the capabilities of existing radio-frequency (RF) communication networks based on coaxial cables on board modem aircrafts. Future avionics systems will require high-bandwidth on- board communication links that are lightweight, immune to electromagnetic interference, and highly reliable. Fiber optic communication technology can meet all these challenges in a cost-effective manner. Recently, digital fiber-optic communication systems, where a fiber-optic network acts like a local area network (LAN) for digital data communications, have become a topic of extensive research and development. Although a fiber-optic system can be designed to transport radio-frequency (RF) signals, the digital fiber-optic systems under development today are not capable of transporting microwave and millimeter-wave RF signals used in radar and avionics systems on board an aircraft. Recent advances in fiber optic technology, especially wavelength division multiplexing (WDM), has opened a number of possibilities for designing on-board fiber optic networks, including all-optical networks for radar and avionics RF signal distribution. In this paper, we investigate a number of different novel approaches for fiber-optic transmission of on-board VHF and UHF RF signals using commercial off-the-shelf (COTS) components. The relative merits and demerits of each architecture are discussed, and the suitability of each architecture for particular applications is pointed out. All-optical approaches show better performance than other traditional approaches in terms of signal-to-noise ratio, power consumption, and weight requirements.

  18. Spectrophotometric properties of dwarf planet Ceres from the VIR spectrometer on board the Dawn mission

    Science.gov (United States)

    Ciarniello, M.; De Sanctis, M. C.; Ammannito, E.; Raponi, A.; Longobardo, A.; Palomba, E.; Carrozzo, F. G.; Tosi, F.; Li, J.-Y.; Schröder, S. E.; Zambon, F.; Frigeri, A.; Fonte, S.; Giardino, M.; Pieters, C. M.; Raymond, C. A.; Russell, C. T.

    2017-02-01

    Aims: We present a study of the spectrophotometric properties of dwarf planet Ceres in the visual-to-infrared (VIS-IR) spectral range by means of hyper-spectral images acquired by the VIR imaging spectrometer on board the NASA Dawn mission. Methods: Disk-resolved observations with a phase angle within the 7° <α < 132° interval were used to characterize Ceres' phase curve in the 0.465-4.05 μm spectral range. Hapke's model was applied to perform the photometric correction of the dataset to standard observation geometry at VIS-IR wavelength, allowing us to produce albedo and color maps of the surface. The V-band magnitude phase function of Ceres has been computed from disk-resolved images and fitted with both the classical linear model and H-G formalism. Results: The single-scattering albedo and the asymmetry parameter at 0.55 μm are w = 0.14 ± 0.02 and ξ = -0.11 ± 0.08, respectively (two-lobe Henyey-Greenstein phase function); at the same wavelength, Ceres' geometric albedo as derived from our modeling is 0.094 ± 0.007; the roughness parameter is bar{θ=29° ± 6°}. Albedo maps indicate small variability on a global scale with an average reflectance at standard geometry of 0.034 ± 0.003. Nonetheless, isolated areas such as the Occator bright spots, Haulani, and Oxo show an albedo much higher than average. We measure a significant spectral phase reddening, and the average spectral slope of Ceres' surface after photometric correction is 1.1% kÅ-1 and 0.85% kÅ-1 at VIS and IR wavelengths, respectively. Broadband color indices are V-R = 0.38 ± 0.01 and R-I = 0.33 ± 0.02. Color maps show that the brightest features typically exhibit smaller slopes. The H-G modeling of the V-band magnitude phase curve for α < 30° gives H = 3.14 ± 0.04 and G = 0.10 ± 0.04, while the classical linear model provides V(1,1,0°) = 3.48 ± 0.03 and β = 0.036 ± 0.002. The comparison of our results with spectrophotometric properties of other minor bodies indicates that Ceres

  19. On the possibility of TLE measurements with high sensitivity and temporal resolution by TUS detector on board Lomonosov satellite

    Science.gov (United States)

    Klimov, P.; Garipov, G.; Khrenov, B.; Morozenko, V.; Panasyuk, M.; Sharakin, S.; Yashin, I.

    2012-12-01

    Moscow State University in collaboration with other Russian and foreign institutions is preparing a new scientific and educational satellite Lomonosov. Its scientific payload consists of various detectors which measurements directed mostly to extreme processes in the far Universe (gamma ray bursts - GRB and ultra high energy cosmic rays - UHECR). Near Earth extreme phenomena, like atmospheric transient luminous events (TLE) can be considered as additional scientific objectives for detector TUS. The UHECR detector TUS will observe faint fluorescent tracks of extensive air shower (EAS), produced by a primary energetic particle in the atmosphere. For this purpose the detector contains a large Fresnel-type mirror-concentrator (~2 sq.m.) and photo receiver placed in the focal plane (matrix of 16x16 PM tubes with a spatial resolution in the atmosphere ~ 5 km). Electronics allow to achieve a microsecond time sampling for the fastest events and sub-millisecond for the slower ones. In addition to the main photo receiver, which measure UV light collected by a mirror, there was installed a pin-hole camera with two multi anode PM tubes orientated directly to the atmosphere. It has the same FOV, but smaller aperture ratio. The main photo receiver of TUS detector will measure more faint light (EAS fluorescence, TLE initial stage, meteor tracks). In case of large signal and TUS electronics saturation, the pin-hole camera will continue measurements and provide additional information about luminous events. Estimations of TLE frequency and their intensity in UV wavelength range could be done based on Universitetsy-Tatiana-2 satellite data. In the presented work a possibility of transient luminous events measurements from space by TUS detector with high sensitivity and temporal resolution is discussed.

  20. Surveillance study of vector species on board passenger ships, Risk factors related to infestations

    Directory of Open Access Journals (Sweden)

    Hatzoglou Chrissi

    2008-03-01

    Full Text Available Abstract Background Passenger ships provide conditions suitable for the survival and growth of pest populations. Arthropods and rodents can gain access directly from the ships' open spaces, can be carried in shiploads, or can be found on humans or animals as ectoparasites. Vectors on board ships may contaminate stored foods, transmit illness on board, or, introduce diseases in new areas. Pest species, ship areas facilitating infestations, and different risk factors related to infestations were identified in 21 ferries. Methods 486 traps for insects and rodents were placed in 21 ferries. Archives of Public Health Authorities were reviewed to identify complaints regarding the presence of pest species on board ferries from 1994 to 2004. A detail questionnaire was used to collect data on ship characteristics and pest control practices. Results Eighteen ferries were infested with flies (85.7%, 11 with cockroaches (52.3%, three with bedbugs, and one with fleas. Other species had been found on board were ants, spiders, butterflies, beetles, and a lizard. A total of 431 Blattella germanica species were captured in 28 (9.96% traps, and 84.2% of them were nymphs. One ship was highly infested. Cockroach infestation was negatively associated with ferries in which Hazard Analysis Critical Control Point system was applied to ensure food safety on board (Relative Risk, RR = 0.23, p = 0.03, and positively associated with ferries in which cockroaches were observed by crew (RR = 4.09, p = 0.007, no cockroach monitoring log was kept (RR = 5.00, p = 0.02, and pesticide sprays for domestic use were applied by crew (RR = 4.00, p = 0.05. Cockroach infested ships had higher age (p = 0.03. Neither rats nor mice were found on any ship, but three ferries had been infested with a rodent in the past. Conclusion Integrated pest control programs should include continuing monitoring for a variety of pest species in different ship locations; pest control measures should be more

  1. USING THE INFORMATION OF ON-BOARD DIAGNOSTIC SYSTEMS IN DETERMINING THE TECHNICAL STATE OF THE LOCOMOTIVE

    Directory of Open Access Journals (Sweden)

    B. Ye. Bodnar

    2008-12-01

    Full Text Available The issues of increase of efficiency of information processing by оn-board systems of diagnostics of locomotives are considered. The examples of information processing by the on-board system of diagnostics of electric locomotives DE1 are presented. The suggestions on improvement of systematization and processing of information by on-board systems of diagnostics are given.

  2. Effectiveness Evaluation on Fire Drills for Emergency and PSC Inspections on Board

    Directory of Open Access Journals (Sweden)

    Jianjun Wu

    2014-06-01

    Full Text Available The paper evaluates effectiveness of fire drills for emergency and responding to PSC inspections on board. A brief background about the PSC inspection on fire drills on board is introduced in the beginning. Then the significance of effectiveness evaluation on fire drills is presented. Next, legal ground is discussed on International Conventions, including regulation of related regional group, national maritime laws and rules and Concentrated Inspection Campaign (CIC. Furthermore, PSC New Inspection Regime (NIR for Paris MOU and Tokyo MOU are also discussed, and many deficiencies related to fire safety measures found in the PSC inspection are statistically analyzed. More importantly, the paper introduces System Engineering Theory, presents the principle and method of effectiveness evaluation, focuses on the preparation, performance and rehabilitation of fire drill and develops the Criterion of Effectiveness Evaluation. Finally, some suggestions are raised to carry out effectiveness evaluation for emergency and responding to the PSC inspection.

  3. An On-Board TLD System for Dose Monitoring on the International Space Station

    Energy Technology Data Exchange (ETDEWEB)

    Apathy, I.; Deme, S.; Bodnar, L.; Csoeke, A.; Hejja, I

    1999-07-01

    This institute has developed and manufactured a series of thermoluminescence dosemeter (TLD) systems for spacecraft, consisting of a set of bulb dosemeters and a small, compact TLD reader suitable for on-board evaluation of the dosemeters. By means of such a system highly accurate measurements were carried out on board the Salyut-6, -7 and Mir Space Stations as well as on the Space Shuttle. A new implementation of the system will be placed on several segments of the ISS as the contribution of Hungary to this international enterprise. The well proven CaSO{sub 4}:Dy dosemeters will be used for routine dosimetry of the astronauts and in biological experiments. The mean LET value will be measured by LiF dosemeters while doses caused by neutrons are planned to be determined by {sup 6}LiF/{sup 7}LiF dosemeter pairs and moderators. A detailed description of the system is given. (author)

  4. The Experiment CPLM (Comportamiento De Puentes Líquidos En Microgravedad) On Board MINISAT 01

    Science.gov (United States)

    Sanz-Andrés, Angel; Rodríguez-De-Francisco, Pablo; Santiago-Prowald, Julián

    2001-03-01

    The Universidad Politécnica de Madrid participates in the MINISAT 01 program as the experiment CPLM responsible. This experiment aims at the study of the fluid behaviour in reduced gravity conditions. The interest of this study is and has been widely recognised by the scientific community and has potential applications in the pharmaceutical and microelectronic technologies (crystal growth), among others. The scientific team which has developed the CPLM experiment has a wide experience in this field and had participate in the performance of a large number of experiments on the fluid behaviour in reduced gravity conditions in flight (Spacelab missions, TEXUS sounding rockets, KC-135 and Caravelle aeroplanes, drop towers, as well as on earth labs (neutral buoyancy and small scale simulations). The experimental equipment used in CPLMis a version of the payload developed for experimentation on drop towers and on board microsatellites as the UPM-Sat 1, adapted to fly on board MINISAT 01.

  5. Alternative methods of fuel consumption metering based on the on-board diagnostics outputs

    Directory of Open Access Journals (Sweden)

    Jiří Čupera

    2005-01-01

    Full Text Available The article describes alternative methods of fuel consumption measurement based on model with using the diagnostic outputs of engine control unit. On-board diagnosis (the second level, known as OBD-2 has been mandated by government regulation because of advanced damage control systems in newer cars. However, its signals can be used for accurate analyses of power or torque measurement. On-board diagnostics offers many various parameters such a spark advance, intake air temperature, coolant temperature, throttle position, air flow mass and so on. Many of them have been unavailable without using sophisticated and expensive instrumentation. In the article are described two ways of fuel consumption measuring which are based on intake air consumption and knowledge about air-fuel ratio. First of them is founded on voltage output of oxygen sensor, the second on short (long term fuel trim. As is shown at the end the second way gives more accurately results.

  6. Five Years Lidar Research on Board the Facility for Airborne Atmospheric Measurements (FAAM

    Directory of Open Access Journals (Sweden)

    Marenco Franco

    2016-01-01

    Full Text Available I will present a summary of the results obtained with the backscatter lidar on-board the FAAM research aircraft. This simple instrument has been used in several campaigns, and has contributed successfully to the characterization of volcanic ash, mineral dust, biomass burning aerosols, clouds, and the boundary layer structure. Its datasets have been used in many applications, from numerical weather predictions to the validation of satellite remote sensing.

  7. Five Years Lidar Research on Board the Facility for Airborne Atmospheric Measurements (FAAM)

    Science.gov (United States)

    Marenco, Franco

    2016-06-01

    I will present a summary of the results obtained with the backscatter lidar on-board the FAAM research aircraft. This simple instrument has been used in several campaigns, and has contributed successfully to the characterization of volcanic ash, mineral dust, biomass burning aerosols, clouds, and the boundary layer structure. Its datasets have been used in many applications, from numerical weather predictions to the validation of satellite remote sensing.

  8. Bifurcation Analysis of a Non-linear On-Board Rotor-Bearing System

    OpenAIRE

    Dakel, M. Zaki; Baguet, Sébastien; Dufour, Régis

    2014-01-01

    International audience; The non-linear dynamic behavior of an on-board rotor mounted on hydrodynamic journal bearings and subject to rigid base excitations is investigated in this work. The proposed finite element rotor model takes into account the geometric asymmetry of shaft and/or rigid disk and considers six types of base deterministic motions (rotations and translations) and non-linear fluid film forces obtained from the Reynoldsequation. The equations of motion contain time-varying para...

  9. Investigation on the Dynamics of an On-Board Rotor-Bearing System

    OpenAIRE

    Dakel, M. Zaki; Baguet, Sébastien; Dufour, Régis

    2012-01-01

    International audience; In ship and aircraft turbine rotors, the rotating mass unbalance and the different movements of the rotor base are among the main causes of vibrations in bending. The goal of this paper is to investigate the dynamic behavior of an on-board rotor under rigid base excitations. The modeling takes into consideration six types of base deterministic motions (rotations and translations) when the kinetic and strain energies in addition to the virtual work of the rotating flexi...

  10. Increasing the object recognition distance of compact open air on board vision system

    Science.gov (United States)

    Kirillov, Sergey; Kostkin, Ivan; Strotov, Valery; Dmitriev, Vladimir; Berdnikov, Vadim; Akopov, Eduard; Elyutin, Aleksey

    2016-10-01

    The aim of this work was developing an algorithm eliminating the atmospheric distortion and improves image quality. The proposed algorithm is entirely software without using additional hardware photographic equipment. . This algorithm does not required preliminary calibration. It can work equally effectively with the images obtained at a distances from 1 to 500 meters. An algorithm for the open air images improve designed for Raspberry Pi model B on-board vision systems is proposed. The results of experimental examination are given.

  11. Organizing for naval operations: Implementing mission command on board the Nansen-class frigates

    OpenAIRE

    Krabberød, Tommy

    2015-01-01

    The motivation for this dissertation was an empirical one; how to design an effective organization for the new state-of-the art Nansen-class frigates. There is, however, no official tool for designing and diagnosing the organization structure in the Norwegian Armed Forces. Having found Mintzberg’s (1979) renowned configuration theory to be useful in a qualitative oriented study of leadership and organization on board the Oslo-class frigates that were to be replaced (Krabberød, ...

  12. Organizing for naval operations: Implementing mission command on board the Nansen-class frigates

    OpenAIRE

    Krabberød, Tommy

    2015-01-01

    The motivation for this dissertation was an empirical one; how to design an effective organization for the new state-of-the art Nansen-class frigates. There is, however, no official tool for designing and diagnosing the organization structure in the Norwegian Armed Forces. Having found Mintzberg’s (1979) renowned configuration theory to be useful in a qualitative oriented study of leadership and organization on board the Oslo-class frigates that were to be replaced (Krabberød, 20...

  13. Cavity-Enhanced Real-Time Monitoring of Single-Charge Jumps at the Microsecond Time Scale

    Directory of Open Access Journals (Sweden)

    C. Arnold

    2014-04-01

    Full Text Available We use fast coherent reflectivity measurements, in a strongly coupled quantum dot micropillar device, to monitor in real time single-charge jumps at the microsecond time scale. Thanks to the strong enhancement of light-matter interaction inside the cavity, and to a close to shot-noise-limited detection setup, the measurement rate is 5 orders of magnitude faster than with previous optical experiments of direct single-charge sensing with quantum dots. The monitored transitions, identified at any given time with a less than 0.2% error probability, correspond to a carrier being captured and then released by a single material defect. This high-speed technique opens the way for the real-time monitoring of other rapid single quantum events, such as the quantum jumps of a single spin.

  14. High pulse energy, high beam quality microsecond-pulse Ti:sapphire laser at 819.7 nm

    Science.gov (United States)

    Xu, Chang; Guo, Chuan; Yu, Hai-Bo; Wang, Zhi-Min; Zuo, Jun-Wei; Xia, Yuan-Qin; Bian, Qi; Bo, Yong; Gao, Hong-Wei; Guo, Ya-Ding; Zhang, Sheng; Cui, Da-Fu; Peng, Qin-Jun; Xu, Zu-Yan

    2017-03-01

    In this letter, a high pulse energy and high beam quality 819.7 nm Ti:sapphire laser pumped by a frequency-doubled Nd:YAG laser is demonstrated. At incident pump energy of 774 mJ, the maximum output energy of 89 mJ at 819.7 nm with a pulse width of 100 μs is achieved at a repetition rate of 5 Hz. To the best of our knowledge, this is the highest pulse energy at 819.7 nm with pulse width of hundred microseconds for a Ti:sapphire laser. The beam quality factor M 2 is measured to be 1.18. This specific wavelength with the high pulse energy and high beam quality at 819.7 nm is a promising light source to create a polychromatic laser guide star together with a home-made 589 nm laser via exciting the sodium atoms in the mesospheric atmosphere.

  15. Conformational changes and slow dynamics through microsecond polarized atomistic molecular simulation of an integral Kv1.2 ion channel

    DEFF Research Database (Denmark)

    Bjelkmar, Pär; Niemelä, Perttu S; Vattulainen, Ilpo

    2009-01-01

    transitions occur in membrane proteins-not to mention numerous applications in drug design. Here, we present a full 1 micros atomic-detail molecular dynamics simulation of an integral Kv1.2 ion channel, comprising 120,000 atoms. By applying 0.052 V/nm of hyperpolarization, we observe structural rearrangements......Structure and dynamics of voltage-gated ion channels, in particular the motion of the S4 helix, is a highly interesting and hotly debated topic in current membrane protein research. It has critical implications for insertion and stabilization of membrane proteins as well as for finding how...... and significant thinning of the membrane also observed in experiments, this provides additional support for the predictive power of microsecond-scale membrane protein simulations....

  16. Risk Mitigation for the Development of the New Ariane 5 On-Board Computer

    Science.gov (United States)

    Stransky, Arnaud; Chevalier, Laurent; Dubuc, Francois; Conde-Reis, Alain; Ledoux, Alain; Miramont, Philippe; Johansson, Leif

    2010-08-01

    In the frame of the Ariane 5 production, some equipment will become obsolete and need to be redesigned and redeveloped. This is the case for the On-Board Computer, which has to be completely redesigned and re-qualified by RUAG Space, as well as all its on-board software and associated development tools by ASTRIUM ST. This paper presents this obsolescence treatment, which has started in 2007 under an ESA contract, in the frame of ACEP and ARTA accompaniment programmes, and is very critical in technical term but also from schedule point of view: it gives the context and overall development plan, and details the risk mitigation actions agreed with ESA, especially those related to the development of the input/output ASIC, and also the on-board software porting and revalidation strategy. The efficiency of these risk mitigation actions has been proven by the outcome schedule; this development constitutes an up-to-date case for good practices, including some experience report and feedback for future other developments.

  17. Preliminary on-orbit performance of the Thermal Infrared Sensor (TIRS) on board Landsat 8

    Science.gov (United States)

    Montanaro, Matthew; Tesfaye, Zelalem; Lunsford, Allen; Wenny, Brian; Reuter, Dennis; Markham, Brian; Smith, Ramsey; Thome, Kurtis

    2013-09-01

    The Thermal Infrared Sensor (TIRS) on board Landsat 8 continues thermal band measurements of the Earth for the Landsat program. TIRS improves on previous Landsat designs by making use of a pushbroom sensor layout to collect data from the Earth in two spectral channels. The radiometric performance requirements of each detector were set to ensure the proper radiometric integrity of the instrument. The performance of TIRS was characterized during pre-flight thermal-vacuum testing. Calibration methods and algorithms were developed to translate the raw signal from the detectors into an accurate at-aperture spectral radiance. The TIRS instrument has the ability to view an on-board variable-temperature blackbody and a deep space view port for calibration purposes while operating on-orbit. After TIRS was successfully activated on-orbit, checks were performed on the instrument data to determine its image quality. These checkouts included an assessment of the on-board blackbody and deep space views as well as normal Earth scene collects. The calibration parameters that were determined pre-launch were updated by utilizing data from these preliminary on-orbit assessments. The TIRS on-orbit radiometric performance was then characterized using the updated calibration parameters. Although the characterization of the instrument is continually assessed over the lifetime of the mission, the preliminary results indicate that TIRS is meeting the noise and stability requirements while the pixel-to-pixel uniformity performance and the absolute radiometric performance require further study.

  18. Stationary and on-board storage systems to enhance energy and cost efficiency of tramways

    Science.gov (United States)

    Ceraolo, M.; Lutzemberger, G.

    2014-10-01

    Nowadays road transportation contributes in a large amount to the urban pollution and greenhouse gas emissions. One solution in urban environment, also in order to mitigate the effects of traffic jams, is the use of tramways. The most important bonus comes from the inherent reversibility of electric drives: energy can be sent back to the electricity source, while braking the vehicle. This can be done installing some storage device on-board trains, or in one or more points of the supply network. This paper analyses and compares the following variants: Stationary high-power lithium batteries. Stationary supercapacitors. High-power lithium batteries on-board trains. Supercapacitors on-board trains. When the storage system is constituted by a supercapacitor stack, it is mandatory to interpose between it and the line a DC/DC converter. On the contrary, the presence of the converter can be avoided, in case of lithium battery pack. This paper will make an evaluation of all these configurations, in a realistic case study, together with a cost/benefit analysis.

  19. JURISDICTION OVER CRIMES COMMITTED ON BOARD AIRCRAFT IN FLIGHT UNDER THE TOKYO CONVENTION 1963

    Directory of Open Access Journals (Sweden)

    Iryna Sopilko

    2016-12-01

    Full Text Available Purpose: the main aim of this paper is to clarify several issues of conflicting jurisdiction over crimes committed on board aircraft in flight. The study will examine the way in which the Tokyo Convention attempts to provide justice in the event of aviation security violations, and discuss its effectiveness in preventing such offences in the future. Methods: formal legal and case-study methods together with inductive reasoning, and comparison were used to analyse the legislation in the area of jurisdiction over crimes and other offences committed on board aircraft in flight. Results: it follows from the study that although the Tokyo Convention has contributed considerably to the establishing of clearer rules of jurisdiction over offences committed on board aircraft, considerable deficiencies of this treaty remain. The results have important implications for international policy-making. Discussion: the results of the study reveal several weaknesses of the Tokyo Convention. Firstly, it does not provide any definition or list of offences to which it applies, instead it relies on national penal laws to do so. In addition, the ‘freedom fighter exception’ and the lack of a strong enforcement mechanism may prove to impede the effective attainment of the Tokyo Convention’s main objectives – that is, to provide justice in the event of aviation security violations, and prevent such offences in the future. Therefore, further improvement in aviation security legislation is necessary to ensure that it is effective and adequate in the challenges faced today.

  20. University of the seas, 15 years of oceanographic schools on board of the Marion Dufresne

    Science.gov (United States)

    Malaize, Bruno; Deverchere, Jacques; Leau, Hélène; Graindorge, David

    2015-04-01

    Since the first University at Sea, proposed by two French Universities (Brest and Bordeaux) in 1999, the R/V Marion Dufresne, in collaboration with the French Polar institute (IPEV), has welcome 12 oceanographic schools. The main objective of this educational and scientific program is to stimulate the potential interest of highly graduated students in scientific fields dealing with oceanography, and to broaden exchanges with foreign universities, strengthening a pool of excellence at a high international scientific level. It is a unique opportunity for the students to discover and to be involved in the work in progress of collecting scientific data on board of a ship, and to attend international research courses given by scientists involved in the cruise program. They also experience the final task of the scientific work by presenting their own training results, making posters on board, and writing a cruise report. For some University at Sea, students had also updated a daily journal, available on internet, hosted by the main institutions involved (as IPEV or EPOC, Bordeaux University). All this work is done in English, a common language to all the participants. An overview of these 15 years background experience will be presented, underlying the financial supports used, the logistic on board, as well as all the benefits acquiered by all former students, now in permanent positions in different international institutions.

  1. Sub-Microsecond Temperature Measurement in Liquid Water Using Laser Induced Thermal Acoustics

    Science.gov (United States)

    Alderfer, David W.; Herring, G. C.; Danehy, Paul M.; Mizukaki, Toshiharu; Takayama, Kazuyoshi

    2005-01-01

    Using laser-induced thermal acoustics, we demonstrate non-intrusive and remote sound speed and temperature measurements over the range 10 - 45 C in liquid water. Averaged accuracy of sound speed and temperature measurements (10 s) are 0.64 m/s and 0.45 C respectively. Single-shot precisions based on one standard deviation of 100 or greater samples range from 1 m/s to 16.5 m/s and 0.3 C to 9.5 C for sound speed and temperature measurements respectively. The time resolution of each single-shot measurement was 300 nsec.

  2. The end-to-end testbed of the optical metrology system on-board LISA Pathfinder

    Energy Technology Data Exchange (ETDEWEB)

    Steier, F; Cervantes, F Guzman; Marin, A F GarcIa; Heinzel, G; Danzmann, K [Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut) and Universitaet Hannover (Germany); Gerardi, D, E-mail: frank.steier@aei.mpg.d [EADS Astrium Satellites GmbH, Friedrichshafen (Germany)

    2009-05-07

    LISA Pathfinder is a technology demonstration mission for the Laser Interferometer Space Antenna (LISA). The main experiment on-board LISA Pathfinder is the so-called LISA Technology Package (LTP) which has the aim to measure the differential acceleration between two free-falling test masses with an accuracy of 3 x 10{sup -14} ms{sup -2} Hz{sup -1/2} between 1 mHz and 30 mHz. This measurement is performed interferometrically by the optical metrology system (OMS) on-board LISA Pathfinder. In this paper, we present the development of an experimental end-to-end testbed of the entire OMS. It includes the interferometer and its sub-units, the interferometer backend which is a phasemeter and the processing of the phasemeter output data. Furthermore, three-axes piezo-actuated mirrors are used instead of the free-falling test masses for the characterization of the dynamic behaviour of the system and some parts of the drag-free and attitude control system (DFACS) which controls the test masses and the satellite. The end-to-end testbed includes all parts of the LTP that can reasonably be tested on earth without free-falling test masses. At its present status it consists mainly of breadboard components. Some of those have already been replaced by engineering models of the LTP experiment. In the next steps, further engineering and flight models will also be inserted in this testbed and tested against well-characterized breadboard components. The presented testbed is an important reference for the unit tests and can also be used for validation of the on-board experiment during the mission.

  3. Single-mode glass waveguide technology for optical interchip communication on board level

    Science.gov (United States)

    Brusberg, Lars; Neitz, Marcel; Schröder, Henning

    2012-01-01

    The large bandwidth demand in long-distance telecom networks lead to single-mode fiber interconnects as result of low dispersion, low loss and dense wavelength multiplexing possibilities. In contrast, multi-mode interconnects are suitable for much shorter lengths up to 300 meters and are promising for optical links between racks and on board level. Active optical cables based on multi-mode fiber links are at the market and research in multi-mode waveguide integration on board level is still going on. Compared to multi-mode, a single-mode waveguide has much more integration potential because of core diameters of around 20% of a multi-mode waveguide by a much larger bandwidth. But light coupling in single-mode waveguides is much more challenging because of lower coupling tolerances. Together with the silicon photonics technology, a single-mode waveguide technology on board-level will be the straight forward development goal for chip-to-chip optical interconnects integration. Such a hybrid packaging platform providing 3D optical single-mode links bridges the gap between novel photonic integrated circuits and the glass fiber based long-distance telecom networks. Following we introduce our 3D photonic packaging approach based on thin glass substrates with planar integrated optical single-mode waveguides for fiber-to-chip and chip-to-chip interconnects. This novel packaging approach merges micro-system packaging and glass integrated optics. It consists of a thin glass substrate with planar integrated singlemode waveguide circuits, optical mirrors and lenses providing an integration platform for photonic IC assembly and optical fiber interconnect. Thin glass is commercially available in panel and wafer formats and characterizes excellent optical and high-frequency properties. That makes it perfect for microsystem packaging. The paper presents recent results in single-mode waveguide technology on wafer level and waveguide characterization. Furthermore the integration in a

  4. On-board closed-loop congestion control for satellite based packet switching networks

    Science.gov (United States)

    Chu, Pong P.; Ivancic, William D.; Kim, Heechul

    1993-01-01

    NASA LeRC is currently investigating a satellite architecture that incorporates on-board packet switching capability. Because of the statistical nature of packet switching, arrival traffic may fluctuate and thus it is necessary to integrate congestion control mechanism as part of the on-board processing unit. This study focuses on the closed-loop reactive control. We investigate the impact of the long propagation delay on the performance and propose a scheme to overcome the problem. The scheme uses a global feedback signal to regulate the packet arrival rate of ground stations. In this scheme, the satellite continuously broadcasts the status of its output buffer and the ground stations respond by selectively discarding packets or by tagging the excessive packets as low-priority. The two schemes are evaluated by theoretical queuing analysis and simulation. The former is used to analyze the simplified model and to determine the basic trends and bounds, and the later is used to assess the performance of a more realistic system and to evaluate the effectiveness of more sophisticated control schemes. The results show that the long propagation delay makes the closed-loop congestion control less responsive. The broadcasted information can only be used to extract statistical information. The discarding scheme needs carefully-chosen status information and reduction function, and normally requires a significant amount of ground discarding to reduce the on-board packet loss probability. The tagging scheme is more effective since it tolerates more uncertainties and allows a larger margin of error in status information. It can protect the high-priority packets from excessive loss and fully utilize the downlink bandwidth at the same time.

  5. On-board safety monitoring systems for driving: review, knowledge gaps, and framework.

    Science.gov (United States)

    Horrey, William J; Lesch, Mary F; Dainoff, Marvin J; Robertson, Michelle M; Noy, Y Ian

    2012-02-01

    Fatal highway incidents remain the leading type of fatal work-related event, carrying tremendous personal, social, and economic costs. While employers with a fixed worksite can observe and interact directly with workers in an effort to promote safety and reduce risk, employers with workers who operate a motor vehicle as part of their job have fewer options. New technologies such as on-board safety monitoring systems offer the potential to further improve safety. These technologies allow vehicle owners to collect safety-specific information related to a driver's on-the-road behavior and performance. While many such devices are being developed and implemented in both commercial fleets and private vehicles, the scientific examination of these devices has lagged by comparison. In the current paper, we: (a) describe the general features and functionality of current generations of on-board monitoring devices and how they might impact various driver behaviors; (b) review the current state of scientific knowledge specific to on-board devices; (c) discuss knowledge gaps and potential areas for future research, borrowing from the related domain of computer-based electronic performance monitoring (EPM); and (d) propose a framework that can be used to explore some of the human-system interactions pertaining to monitoring systems. Motor vehicle crashes can carry tremendous costs for employers, in terms of injury, disability, and loss of potentially productive work years. New technologies can offer tremendous benefits in terms of promoting safer on-the-road behaviors. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. The development of a computational platform to design and simulate on-board hydrogen storage systems

    DEFF Research Database (Denmark)

    Mazzucco, Andrea; Rokni, Masoud

    2017-01-01

    A computational platform is developed in the Modelica® language within the Dymola™ environment to provide a tool for the design and performance comparison of on-board hydrogen storage systems. The platform has been coupled with an open source library for hydrogen fueling stations to investigate t...... to a storage capacity four times larger than a tube-in-tube solution of the same size. The volumetric and gravimetric densities of the shell and tube are 2.46% and 1.25% respectively. The dehydriding ability of this solution is proven to withstand intense discharging conditions....

  7. Portable Simulator for On-Board International Space Station Emergency Training

    Science.gov (United States)

    Bolt, Kathy; Root, Michael

    2014-01-01

    The crew on-board the International Space Station (ISS) have to be prepared for any possible emergency. The emergencies of most concern are a fire, depressurization or a toxic atmosphere. The crew members train on the ground before launch but also need to practice their emergency response skills while they are on orbit for 6 months. On-Board Training (OBT) events for emergency response proficiency used to require the crew and ground teams to use paper "scripts" that showed the path through the emergency procedures. This was not very realistic since the participants could read ahead and never deviate from this scripted path. The new OBT emergency simulator allows the crew to view dynamic information on an iPad only when it would become available during an event. The simulator interface allows the crew member to indicate hatch closures, don and doff masks, read pressures, and sample smoke or atmosphere levels. As the crew executes their actions using the on-board simulator, the ground teams are able to monitor those actions via ground display data flowing through the ISS Ku Band communication system which syncs the on-board simulator software with a ground simulator which is accessible in all the control centers. The OBT Working Group (OBT WG), led by the Chief Training Office (CTO) at Johnson Space center is a Multilateral working group with partners in Russia, Japan, Germany and U.S.A. The OBTWG worked together to create a simulator based on these principles: (a) Create a dynamic simulation that gives real-time data feedback; (b) Maintain real-time interface between Mission Control Centers and crew during OBTs; (c) Provide flexibility for decision making during drill execution; (d) Materially reduce Instructor and Flight Control Team man-hour costs involved with developing, updating, and maintaining emergency OBT cases/scenarios; and (e) Introduce an element of surprise to emergency scenarios so the team can't tell the outcome of the case by reading ahead in a

  8. Performance analysis of different organic Rankine cycle configurations on board liquefied natural gas-fuelled vessels

    DEFF Research Database (Denmark)

    Baldasso, Enrico; Andreasen, Jesper Graa; Meroni, Andrea

    2017-01-01

    natural gas (LNG). The study compares the performance of six different ORC configurations both in design and off-design operation, and provides guidelines with respect to the most promising heat sources and sinks to be utilized by an ORC unit in order to maximize the annual fuel savings. In addition......Gas-fuelled shipping is expected to increase significantly in the coming years. Similarly, much effort is devoted to the study of waste heat recovery systems to be implemented on board ships. In this context, the organic Rankine cycle (ORC) technology is considered one of the most promising...

  9. Cultural differences in emotional intelligence among top officers on board merchant ships.

    Science.gov (United States)

    Johnsen, Bjørn Helge; Meeùs, Philippine; Meling, Jon; Rogde, Torbjørn; Eid, Jarle; Esepevik, Roar; Olsen, Olav Kjellevold; Sommerfelt-Pettersen, Jan

    2012-01-01

    The current research investigated cultural differences in emotional intelligence among top officers on board vessels of multicultural maritime companies. We found that Southeast Asian officers scored higher than European officers on the total Emotional Intelligence scale. When separating the EQ scale in its facets, higher scores for Asian officers were found on "Utilization of emotions", "Handling relationships", and on "Self-control". Another finding was that Chief officers/Second engineers scored higher than Masters/Chief Officers on "Self-control". Finally, we found a negative correlation between age and scores on the facet of "Self-control". These crosscultural differences may have implications for interpersonal relations and ship management.

  10. Small, Light-Weight Pump Technology for On-Board Pressurization of Propellants in a Mars Ascent Vehicle Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To-date, the realization of high-performance liquid bipropellant rocket engines in the micro-scale has largely been hindered by the inability to obtain "on-board"...

  11. Real-Time On-Board Processing Validation of MSPI Ground Camera Images

    Science.gov (United States)

    Pingree, Paula J.; Werne, Thomas A.; Bekker, Dmitriy L.

    2010-01-01

    The Earth Sciences Decadal Survey identifies a multiangle, multispectral, high-accuracy polarization imager as one requirement for the Aerosol-Cloud-Ecosystem (ACE) mission. JPL has been developing a Multiangle SpectroPolarimetric Imager (MSPI) as a candidate to fill this need. A key technology development needed for MSPI is on-board signal processing to calculate polarimetry data as imaged by each of the 9 cameras forming the instrument. With funding from NASA's Advanced Information Systems Technology (AIST) Program, JPL is solving the real-time data processing requirements to demonstrate, for the first time, how signal data at 95 Mbytes/sec over 16-channels for each of the 9 multiangle cameras in the spaceborne instrument can be reduced on-board to 0.45 Mbytes/sec. This will produce the intensity and polarization data needed to characterize aerosol and cloud microphysical properties. Using the Xilinx Virtex-5 FPGA including PowerPC440 processors we have implemented a least squares fitting algorithm that extracts intensity and polarimetric parameters in real-time, thereby substantially reducing the image data volume for spacecraft downlink without loss of science information.

  12. Noise exposure and cognitive performance: A study on personnel on board Royal Norwegian Navy vessels

    Directory of Open Access Journals (Sweden)

    Kaja Irgens-Hansen

    2015-01-01

    Full Text Available Prior research shows that work on board vessels of the Royal Norwegian Navy (RNoN is associated with noise exposure levels above recommended standards. Further, noise exposure has been found to impair cognitive performance in environmental, occupational, and experimental settings, although prior research in naval and maritime settings is sparse. The aim of this study was to evaluate cognitive performance after exposure to noise among personnel working on board vessels in the RNoN. Altogether 87 Navy personnel (80 men, 7 women; 31 ± 9 years from 24 RNoN vessels were included. Noise exposure was recorded by personal noise dosimeters at a minimum of 4 h prior to testing, and categorized into 4 groups for the analysis: 85.2 dB(A. The participants performed a visual attention test based on the Posner cue-target paradigm. Multivariable general linear model (GLM analyses were performed to analyze whether noise exposure was associated with response time (RT when adjusting for the covariates age, alertness, workload, noise exposure in test location, sleep the night before testing, use of hearing protection device (HPD, and percentage of errors. When adjusting for covariates, RT was significantly increased among personnel exposed to >85.2 dB(A and 77.1-85.2 dB(A compared to personnel exposed to <72.6 dB(A.

  13. Noise exposure and cognitive performance: A study on personnel on board Royal Norwegian Navy vessels.

    Science.gov (United States)

    Irgens-Hansen, Kaja; Gundersen, Hilde; Sunde, Erlend; Baste, Valborg; Harris, Anette; Bråtveit, Magne; Moen, Bente E

    2015-01-01

    Prior research shows that work on board vessels of the Royal Norwegian Navy (RNoN) is associated with noise exposure levels above recommended standards. Further, noise exposure has been found to impair cognitive performance in environmental, occupational, and experimental settings, although prior research in naval and maritime settings is sparse. The aim of this study was to evaluate cognitive performance after exposure to noise among personnel working on board vessels in the RNoN. Altogether 87 Navy personnel (80 men, 7 women; 31 ± 9 years) from 24 RNoN vessels were included. Noise exposure was recorded by personal noise dosimeters at a minimum of 4 h prior to testing, and categorized into 4 groups for the analysis: 85.2 dB(A). The participants performed a visual attention test based on the Posner cue-target paradigm. Multivariable general linear model (GLM) analyses were performed to analyze whether noise exposure was associated with response time (RT) when adjusting for the covariates age, alertness, workload, noise exposure in test location, sleep the night before testing, use of hearing protection device (HPD), and percentage of errors. When adjusting for covariates, RT was significantly increased among personnel exposed to >85.2 dB(A) and 77.1-85.2 dB(A) compared to personnel exposed to <72.6 dB(A).

  14. Development of models for on-board detection of driver impairment.

    Science.gov (United States)

    Dingus, T A; Hardee, H L; Wierwille, W W

    1987-08-01

    Two of the leading causes of automobile accidents are driver impairment due to alcohol and drowsiness. Apparently, a relatively large percentage of these accidents occur because drivers are unaware of the degree to which they are impaired. The purpose of this research was to develop models, utilizing changes in driver behavior, which could detect driver impairment due to alcohol, drowsiness, or the combination of alcohol and drowsiness, and which could be practically implemented in an automobile. A computer-controlled automobile simulator was used to simulate a nighttime highway driving scenario for six drivers who participated in each of four conditions: a control condition, an alcohol condition, a sleep-deprived condition, and a combined alcohol and sleep-deprived condition. The results indicated that a useful on-board drowsiness detection device is possible and practical for highway driving. The results also showed that on-board alcohol impairment detection may be possible at levels below the legal driving limit in most states (BAC 0.1%).

  15. ELITE S2 - A Facility for Quantitative Human Movement Analysis on Board the ISS

    Science.gov (United States)

    Neri, Gianluca; Mascetti, Gabriele; Zolesi, Valfredo

    2014-11-01

    This paper describes the activities for utilization and control of ELITE S2 on board the International Space Station (ISS). ELITE S2 is a payload of the Italian Space Agency (ASI) for quantitative human movement analysis in weightlessness. Within the frame of a bilateral agreement with NASA, ASI has funded a number of facilities, enabling different scientific experiments on board the ISS. ELITE S2 has been developed by the ASI contractor Kayser Italia, delivered to the Kennedy Space Center in 2006 for pre-flight processing, launched in 2007 by the Space Shuttle Endeavour (STS-118), integrated in the U.S. lab and used during the Increments 16/17 (2008) and 33/34 (2012/2013). The ELITE S2 flight segment comprises equipment mounted into an Express Rack and a number of stowed items to be deployed for experiment performance (video cameras and accessories). The ground segment consists in a User Support Operations Center (based at Kayser Italia) enabling real-time payload control and a number of User Home Bases (located at the ASI and PIs premises), for the scientific assessment of the experiment performance. Two scientific protocols on reaching and cognitive processing have been successfully performed in eight sessions involving three ISS crewmembers: IMAGINE 2 and MOVE.

  16. An ontology-based consultation system to support medical care on board seagoing vessels.

    Science.gov (United States)

    Carletti, Gabrielle; Giuliodori, Paolo; Di Pietri, Vincenzo; Peretti, Alessandro; Amenta, Francesco

    2016-01-01

    A realistic possibility to obtain medical care for patients located in remote sites such as seagoing vessels, in which health professionals are not available, is to contact a doctor via telecommunication systems. In general, the medical knowledge of who on board ships is in charge of medical care is quite limited and therefore, in a first level telemedical consultation, the flow of information should be correct and its efficiency should be maximised. This paper describes an application conceived to improve requests of medical assistance from sailing ships. The ultimate objective of this system is a) to standardise as much as possible the requests of medical advice at a distance, b) to overcome language barriers and jammed-related troubles that could make difficult or not understandable a telephone conversation. The application is based on a software engine extracting data from an ontological knowledgebase built ad hoc using Protégé. Compared to the conventional consultation systems based on telephone and e-mail, the proposed device is more accurate and complete in terms of information contained in the request of assistance. Moreover, data received by the medical centre can be more easily managed, as they can be standardised. The system described here allows people responsible of medical care on board ships to forward detailed requests of assistance containing symptom-guided information on patient clinical conditions. This may represent an innovative tool for medical consultations at distance allowing the remote centre to provide more precise and quicker medical advice.

  17. Fault diagnostics for turbo-shaft engine sensors based on a simplified on-board model.

    Science.gov (United States)

    Lu, Feng; Huang, Jinquan; Xing, Yaodong

    2012-01-01

    Combining a simplified on-board turbo-shaft model with sensor fault diagnostic logic, a model-based sensor fault diagnosis method is proposed. The existing fault diagnosis method for turbo-shaft engine key sensors is mainly based on a double redundancies technique, and this can't be satisfied in some occasions as lack of judgment. The simplified on-board model provides the analytical third channel against which the dual channel measurements are compared, while the hardware redundancy will increase the structure complexity and weight. The simplified turbo-shaft model contains the gas generator model and the power turbine model with loads, this is built up via dynamic parameters method. Sensor fault detection, diagnosis (FDD) logic is designed, and two types of sensor failures, such as the step faults and the drift faults, are simulated. When the discrepancy among the triplex channels exceeds a tolerance level, the fault diagnosis logic determines the cause of the difference. Through this approach, the sensor fault diagnosis system achieves the objectives of anomaly detection, sensor fault diagnosis and redundancy recovery. Finally, experiments on this method are carried out on a turbo-shaft engine, and two types of faults under different channel combinations are presented. The experimental results show that the proposed method for sensor fault diagnostics is efficient.

  18. The operational cloud retrieval algorithms from TROPOMI on board Sentinel-5 Precursor

    Directory of Open Access Journals (Sweden)

    D. G. Loyola

    2018-01-01

    Full Text Available This paper presents the operational cloud retrieval algorithms for the TROPOspheric Monitoring Instrument (TROPOMI on board the European Space Agency Sentinel-5 Precursor (S5P mission scheduled for launch in 2017. Two algorithms working in tandem are used for retrieving cloud properties: OCRA (Optical Cloud Recognition Algorithm and ROCINN (Retrieval of Cloud Information using Neural Networks. OCRA retrieves the cloud fraction using TROPOMI measurements in the ultraviolet (UV and visible (VIS spectral regions, and ROCINN retrieves the cloud top height (pressure and optical thickness (albedo using TROPOMI measurements in and around the oxygen A-band in the near infrared (NIR. Cloud parameters from TROPOMI/S5P will be used not only for enhancing the accuracy of trace gas retrievals but also for extending the satellite data record of cloud information derived from oxygen A-band measurements, a record initiated with the Global Ozone Monitoring Experiment (GOME on board the second European Remote-Sensing Satellite (ERS-2 over 20 years ago. The OCRA and ROCINN algorithms are integrated in the S5P operational processor UPAS (Universal Processor for UV/VIS/NIR Atmospheric Spectrometers, and we present here UPAS cloud results using the Ozone Monitoring Instrument (OMI and GOME-2 measurements. In addition, we examine anticipated challenges for the TROPOMI/S5P cloud retrieval algorithms, and we discuss the future validation needs for OCRA and ROCINN.

  19. PHOS Experiment: Thermal Response of a Large Diameter Pulsating Heat Pipe on Board REXUS-18 Rocket

    Science.gov (United States)

    Creatini, F.; Guidi, G. M.; Belfi, F.; Cicero, G.; Fioriti, D.; Di Prizio, D.; Piacquadio, S.; Becatti, G.; Orlandini, G.; Frigerio, A.; Fontanesi, S.; Nannipieri, P.; Rognini, M.; Morganti, N.; Filippeschi, S.; Di Marco, P.; Fanucci, L.; Baronti, F.; Mameli, M.; Marengo, M.; Manzoni, M.

    2015-09-01

    In the present work, the results of two Closed Loop Pulsating Heat Pipes (CLPHPs) tested on board REXUS-1 8 sounding rocket in order to get experimental data over a relatively broad reduced gravity period (about 90 s) are thoroughly discussed. The CLPHPs are partially filled with refrigerant FC-72 and have, respectively, an inner tube diameter larger (3 .0 mm) and slightly smaller (1 .6 mm) than a critical diameter defined on Earth gravity conditions. On ground, the small diameter CLPHP works as a real Pulsating Heat Pipe (PHP): the typical capillary slug flow pattern forms inside the device and the heat exchange is triggered by self-sustained thermally driven oscillations of the working fluid. Conversely, the large diameter CLPHP behaves like a two-phase thermosyphon in vertical position while does not operate in horizontal position as the working fluid stratifies within the tube and surface tension is not able to balance buoyancy. Then, the idea to test the CLPHPs under reduced gravity conditions: as soon as gravity reduces, buoyancy becomes less intense and the typical capillary slug flow pattern can also forms within a tube with a larger diameter. Moreover, this allows to increase the heat transfer rate and, consequently, to decrease the overall thermal resistance. Even though it was not possible to experience the expected reduced gravity conditions due to a failure of the yo-yo de-spin system, the thermal response to the peculiar acceleration field (hyper-gravity) experienced on board are thoroughly described.

  20. Design of on-board parallel computer on nano-satellite

    Science.gov (United States)

    You, Zheng; Tian, Hexiang; Yu, Shijie; Meng, Li

    2007-11-01

    This paper provides one scheme of the on-board parallel computer system designed for the Nano-satellite. Based on the development request that the Nano-satellite should have a small volume, low weight, low power cost, and intelligence, this scheme gets rid of the traditional one-computer system and dual-computer system with endeavor to improve the dependability, capability and intelligence simultaneously. According to the method of integration design, it employs the parallel computer system with shared memory as the main structure, connects the telemetric system, attitude control system, and the payload system by the intelligent bus, designs the management which can deal with the static tasks and dynamic task-scheduling, protect and recover the on-site status and so forth in light of the parallel algorithms, and establishes the fault diagnosis, restoration and system restructure mechanism. It accomplishes an on-board parallel computer system with high dependability, capability and intelligence, a flexible management on hardware resources, an excellent software system, and a high ability in extension, which satisfies with the conception and the tendency of the integration electronic design sufficiently.

  1. ON-BOARD MONITORING OF TECHNICAL STATE FOR POWER UNITS OF WHEELED AND TRACKED VEHICLES

    Directory of Open Access Journals (Sweden)

    Yu. D. Karpievich

    2016-01-01

    Full Text Available The paper considers new methodologies pertaining to on-board diagnosis of wear-out rate for friction linings of a clutch driven disk and friction discs of a hydraulic press clutch of transmission gear boxes which are based on physical process that uses friction work as an integrated indicator. A new methodology in determination of life-span rate for engine oil has been developed in the paper. The paper presents block schematic diagrams for on-board monitoring of technical state for power units of wheeled and tracked vehicles. Usage of friction work as an integrated indicator for determination of wear-out rate for friction linings of clutch driven disk and friction discs of a haydraulic press clutch makes it possible timely at any operational period of wheeled and tracked vehicles to determine their residual operation life and forecast their replacement.While taking volume of the used fuel for determination of engine oil life-span rate it permits quickly and effectively at any operational period of wheeled and tracked vehicles to determine residual useful life of the engine oil and also forecast its replacement.

  2. Application of the Oxidation-Reduction Potential (ORP) for Pre-grading Tuna Freshness On-board

    Science.gov (United States)

    Cheevaporanapivat, Mongkol; Sakai, Hisaharu; Mine, Yuuji; Watanabe, Manabu; Suzuki, Toru

    Application of ORP as a rapid indicator for grading tuna's freshness on the ship was studied. The long line trawling process was used for catching the sample tuna in the South Pacific Ocean. All captured sample tuna were weighed, gender identified and investigated for their mortality, then measured ORP and K value. Three species of tuna were caught: blue marlin (Makaira mazara), yellow fin tuna (Thunnus albacares), and swordfish (Xiphia gladius). Most of the fish captured were male and they had been dead after picking onboard. The measured ORP values of blue marlin varied in the range of 0.295-0.362 Volt, with pH between 5.35-5.84. Both ORP and pH of swordfish was similar to that of blue marlin. But for yellow fin tuna, the ORP value was about the same as blue marlin while its pH was significantly higher. ORP value in all species tended to increase with pH of the fish meat decrease. It is interesting that ORP value of tuna increased in correlation with K value. These results suggested that ORP and pH change, which are measured in the short time, are the effective indicators for grading tuna's freshness on-board.

  3. The EUV-observatory TESIS on board Coronas-Photon: scientific goals and initial plan of observations

    Science.gov (United States)

    Bogachev, Sergey

    The TESIS a EUV-observatory for solar research from space will be launched in 2008 September on board the satellite Coronas-Photon from cosmodrome Plesetsk. TESIS is a project of Lebedev Physical Institute of Russian Academy of Science with contribution from Space Research Center of Polish Academy of Science (the spectrometer SphinX). The experiment will focus on quasi-monochromatic imaging of the Sun and XUV spectroscopy of solar plasma. The scientific payload of TESIS contains five instruments: (1) Bragg crystal spectroheliometer for Sun monochromatic imaging in the line MgXII 8.42 A, (2) the normal-incidence Herschelian EUV telescopes with a resolution of 1.7 arc sec operated in lines FeXXII 133 A, FeIX 171 A and HeII 304 A, (3) the EUV imaging spectrometer, (4) the wide-field Ritchey-Chretien coronograph and (5) the X-ray spectrometer SphinX. The TESIS will focus on coordinated study of solar activity from the transition region to the outer corona up to 4 solar radii in wide temperature range from 5*104 to 2*107 K. We describe the scientific goals of the TESIS and its initial plan of observations.

  4. Some experimental results provided by the ska-3 , uvsips, imap-3 experiments on board the interball-2. A case study

    Science.gov (United States)

    Palazov, K.; Bochev, A.; Spasov, S.; Manev, A.; Raykov, S.; Kuzmin, A.; Shuiskaya, F.; Esmont, N.; Prokhorenko, V.

    2003-04-01

    On board the Auroral satellite the magnetometer IMAP- 3 (STIL) and SKA-3 provide in-situ characteristics of the magnetic field , and of the electrons and ions, respectively. The UV Spectrometer UVSIPS maps ionospheric auroral characteristics in the magnetic field line foot print in 3 lines: 1304 A^o, 1356 A^o and 1493 A^o. On 10/27/1996 a phenomenon was found at the polar edge of the auroral oval in the postmidnight - morning sectors: field-aligned (FA) high-energy upward electron beams in the energy range 20-45 keV at altitudes about 3R_E, accompanied by bidirectional electron FA beams of keV energy. The beam intensity reaches more than 10^4 electrons/s sr keV cm^2 for a time ˜3 10^2-10^3 seconds, when the satellite at the apogee moves slowly within the ILAT-MLT frame.The location of the beams is consistent with a region of downward FA current.We suppose the satellite is in between the bidirectional acceleration regions where a stochastic FA acceleration is accomplished by waves (lower - hybrid, ion -cyclotron, ion-sound, Langmuir and/or lower-hybrid cavitons, or ion holes ) with fluctuating FA electric field components in both directions. Thise case contributes to solving the scientific aims of the Interball project essential understanding of the system Solar wind - Magnetosphere - Ionosphere.

  5. Continuous spectroscopic measurement of methane isotopes and ethane made on board an aircraft: instrument configuration and characterisation

    Science.gov (United States)

    Pitt, Joseph; Young, Stuart; Hopkins, James; Lee, James; Bauguitte, Stéphane; Dorsey, James; Allen, Grant; Gallagher, Martin; Yacovitch, Tara; Zahniser, Mark; Fisher, Rebecca; Lowry, Dave; Nisbet, Euan

    2017-04-01

    We describe the configuration of two commercially available absorption spectrometers for use on board the UK Facility for Airborne Atmospheric Research (FAAM) aircraft. A dual laser instrument has been used to make continuous measurements of the atmospheric 13CH4:12CH4 ratio and ethane mole fraction, using an interband cascade laser (ICL) and a recently developed type of diode laser respectively. Simultaneous measurements of atmospheric ethane have also been made using a single laser instrument employing an ICL, enabling instrument inter-comparison. Instrument performance is evaluated over a series of test flights, and initial results from the MOYA (Methane Observations and Yearly Assessments) campaign, targeting biomass burning plumes in west Africa, are also presented. We describe the calibration procedure and data analysis approaches for methane isotope measurement, involving calibration over a range of methane isotopic composition and methane mole fraction. We assess the effectiveness of this calibration technique during the first MOYA campaign period using measurements of a target cylinder of known composition.

  6. Extra Dose Due to Extravehicular Activity During the NASA4 Mission, Measured by an On-Board TLD System

    Energy Technology Data Exchange (ETDEWEB)

    Deme, S.; Apathy, I.; Hejja, I.; Lang, E.; Feher, I. [Budapest (Hungary)

    1999-07-01

    A microprocessor-controlled on-board TLD system, 'Pille'96', was used during the NASA4 (1997) mission to monitor the cosmic radiation dose inside the Mir Space Station and to measure the extra dose to two astronauts in the course of their extravehicular activity (EVA). For the EVA dose measurements, CaSO{sub 4}:Dy bulb dosemeters were located in specially designed pockets of the ORLAN spacesuits. During an EVA lasting 6 h, the dose ratio inside and outside Mir was measured. During the EVA, Mir crossed the South Atlantic Anomaly three times. Taking into account the influence of these three crossings the mean EVA/internal dose rate ratio was 3.2. Internal dose mapping using CaSO{sub 4}:Dy dosemeters gave mean dose rates ranging from 9.3 to 18.3 {mu}Gy.h{sup -1} at locations where the shielding effect was not the same. Evaluation results of the high temperature region of LiF dosemeters are given to estimate the mean LET. (author)

  7. FAST TRACK COMMUNICATION: Contrasting characteristics of sub-microsecond pulsed atmospheric air and atmospheric pressure helium-oxygen glow discharges

    Science.gov (United States)

    Walsh, J. L.; Liu, D. X.; Iza, F.; Rong, M. Z.; Kong, M. G.

    2010-01-01

    Glow discharges in air are often considered to be the ultimate low-temperature atmospheric pressure plasmas for numerous chamber-free applications. This is due to the ubiquitous presence of air and the perceived abundance of reactive oxygen and nitrogen species in air plasmas. In this paper, sub-microsecond pulsed atmospheric air plasmas are shown to produce a low concentration of excited oxygen atoms but an abundance of excited nitrogen species, UV photons and ozone molecules. This contrasts sharply with the efficient production of excited oxygen atoms in comparable helium-oxygen discharges. Relevant reaction chemistry analysed with a global model suggests that collisional excitation of O2 by helium metastables is significantly more efficient than electron dissociative excitation of O2, electron excitation of O and ion-ion recombination. These results suggest different practical uses of the two oxygen-containing atmospheric discharges, with air plasmas being well suited for nitrogen and UV based chemistry and He-O2 plasmas for excited atomic oxygen based chemistry.

  8. Microsecond simulations indicate that ethanol binds between subunits and could stabilize an open-state model of a glycine receptor.

    Science.gov (United States)

    Murail, Samuel; Wallner, Björn; Trudell, James R; Bertaccini, Edward; Lindahl, Erik

    2011-04-06

    Cys-loop receptors constitute a superfamily of ion channels gated by ligands such as acetylcholine, serotonin, glycine, and γ-aminobutyric acid. All of these receptors are thought to share structural characteristics, but due to high sequence variation and limited structure availability, our knowledge about allosteric binding sites is still limited. These sites are frequent targets of anesthetic and alcohol molecules, and are of high pharmacological importance. We used molecular simulations to study ethanol binding and equilibrium exchange for the homomeric α1 glycine receptor (GlyRα1), modeled on the structure of the Gloeobacter violaceus pentameric ligand-gated channel. Ethanol has a well-known potentiating effect and can be used in high concentrations. By performing two microsecond-scale simulations of GlyR with/without ethanol, we were able to observe spontaneous binding in cavities and equilibrium ligand exchange. Of interest, it appears that there are ethanol-binding sites both between and within the GlyR transmembrane subunits, with the intersubunit site having the highest occupancy and slowest exchange (∼200 ns). This model site involves several residues that were previously identified via mutations as being crucial for potentiation. Finally, ethanol appears to stabilize the GlyR model built on a presumably open form of the ligand-gated channel. This stabilization could help explain the effects of allosteric ligand binding in Cys-loop receptors. Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  9. On-board Payload Data Processing from Earth to Space Segment

    Science.gov (United States)

    Tragni, M.; Abbattista, C.; Amoruso, L.; Cinquepalmi, L.; Bgongiari, F.; Errico, W.

    2013-09-01

    Matching the users application requirements with the more and more huge data streaming of the satellite missions is becoming very complex. But we need both of them. To face both the data management (memory availability) and their transmission (band availability) many recent R&D activities are studying the right way to move the data processing from the ground segment to the space segment by the development of the so-called On-board Payload Data Processing (OPDP). The space designer are trying to find new strategies to increase the on board computation capacity and its viability to overcome such limitations, memory and band, focusing the transmission of remote sensing information (not only data) towards their final use. Some typical applications which can benefit of the on board payload data processing include the automatic control of a satellites constellation which can modify its scheduled acquisitions directly on-board and according to the information extracted from the just acquired data, increasing, for example, the capability of monitoring a specific objective (such as oil spills, illegal traffic) with a greater versatility than a traditional ground segment workflow. The authors and their companies can count on a sound experience in design and development of open, modular and compact on-board processing systems. Actually they are involved in a program, the Space Payload Data Processing (SpacePDP) whose main objective is to develop an hardware and a software framework able to perform both the space mission standard tasks (sensors control, mass storage devices management, uplink and downlink) and the specific tasks required by each mission. SpacePDP is an Open and modular Payload Data Processing system, composed of Hardware and Software modules included a SDK. The whole system is characterised by flexible and customizable building blocks that form the system architectures and by a very easy way to be integrated in the missions by the SDK (a development

  10. The Crab Pulsar in UBVR Bands Simultaneously With 3.3 Microsecond Resolution

    Science.gov (United States)

    Beskin, G. M.; Komarova, V. N.; Plokhotnichenko, V. L.

    1998-12-01

    We present results of the Crab pulsar observations at the 6m telescope in UBVR bands using the photometrical comlex MANIA (Multichannel Analysis of Nanosecond Intensity Alterations). All data are folded with the calculated values of the pulsar rotation parameters. The time resolution of resulting light curves is 3.3 microns. The detailed analysis of the pulse profiles gives shapes of the peaks, which are plateaus (with the duration less than 50 microns for the main pulse), estimations of the bridge intensity, limits for an amplitude of fine temporal (stochastic and regular) structure of the pulses. We define both phase-averaged and phase-resolved colour indices of the pulsar emission and find that colour characteristics are phase-dependent for the both pulses. This behavior is not predicted by current models of pulsar optical emission. The comparative analisys of the light curve shape over the high frequency range is undertaken.

  11. Electron energy and vibrational distribution functions of carbon monoxide in nanosecond atmospheric discharges and microsecond afterglows

    Science.gov (United States)

    Pietanza, L. D.; Colonna, G.; Capitelli, M.

    2017-12-01

    Nanopulse atmospheric carbon monoxide discharges and corresponding afterglows have been investigated in a wide range of applied reduced electric field (130 kinetics of vibrational and electronic excited states as well as to a simplified plasma chemistry for the different species formed during the activation of CO. The molar fraction of electronically excited states generated in the discharge is sufficient to create structures in the EEDF in the afterglow regime. On the other hand, only for long duration pulses (i.e. 50 ns), non-equilibrium vibrational distributions can be observed especially in the afterglow. The trend of the results for the case study E/N = 200 Td, \\text{pulse}=2$ ns is qualitatively and quantitatively similar to the corresponding case for CO2 implying that the activation of CO2 by cold plasmas should take into account the kinetics of formed CO with the same accuracy as the CO2 itself.

  12. Microsecond simulations of the folding/unfolding thermodynamics of the Trp-cage mini protein

    Science.gov (United States)

    Day, Ryan; Paschek, Dietmar; Garcia, Angel E.

    2012-01-01

    We study the unbiased folding/unfolding thermodynamics of the Trp-cage miniprotein using detailed molecular dynamics simulations of an all-atom model of the protein in explicit solvent, using the Amberff99SB force field. Replica-exchange molecular dynamics (REMD) simulations are used to sample the protein ensembles over a broad range of temperatures covering the folded and unfolded states, and at two densities. The obtained ensembles are shown to reach equilibrium in the 1 μs per replica timescale. The total simulation time employed in the calculations exceeds 100 μs. Ensemble averages of the fraction folded, pressure, and energy differences between the folded and unfolded states as a function of temperature are used to model the free energy of the folding transition, ΔG(P,T), over the whole region of temperature and pressures sampled in the simulations. The ΔG(P,T) diagram describes an ellipse over the range of temperatures and pressures sampled, predicting that the system can undergo pressure induced unfolding and cold denaturation at low temperatures and high pressures, and unfolding at low pressures and high temperatures. The calculated free energy function exhibits remarkably good agreement with the experimental folding transition temperature (Tf = 321 K), free energy and specific heat changes. However, changes in enthalpy and entropy are significantly different than the experimental values. We speculate that these differences may be due to the simplicity of the semi-empirical force field used in the simulations and that more elaborate force fields may be required to describe appropriately the thermodynamics of proteins. PMID:20408169

  13. Microsecond enamel ablation with 10.6μm CO2 laser radiation

    Science.gov (United States)

    Góra, W. S.; McDonald, A.; Hand, D. P.; Shephard, J. D.

    2016-02-01

    Lasers have been previously been used for dental applications, however there remain issues with thermally-induced cracking. In this paper we investigate the impact of pulse length on CO2 laser ablation of human dental enamel. Experiments were carried in vitro on molar teeth without any modification to the enamel surface, such as grinding or polishing. In addition to varying the pulse length, we also varied pulse energy and focal position, to determine the most efficient ablation of dental hard tissue and more importantly to minimize or eradicate cracking. The maximum temperature rise during the multi pulse ablation process was monitored using a set of thermocouples embedded into the pulpal chamber. The application of a laser device in dental surgery allows removal of tissue with higher precision, which results in minimal loss of healthy dental tissue. In this study we use an RF discharge excited CO2 laser operating at 10.6μm. The wavelength of 10.6 μm overlaps with a phosphate band (PO3-4) absorption in dental hard tissue hence the CO2 laser radiation has been selected as a potential source for modification of the tissue. This research describes an in-depth analysis of single pulse laser ablation. To determine the parameters that are best suited for the ablation of hard dental tissue without thermal cracking, a range of pulse lengths (10-200 μs), and fluences (0-100 J/cm2) are tested. In addition, different laser focusing approaches are investigated to select the most beneficial way of delivering laser radiation to the surface (divergent/convergent beam). To ensure that these processes do not increase the temperature above the critical threshold and cause the necrosis of the tissue a set of thermocouples was placed into the pulpal chambers. Intermittent laser radiation was investigated with and without application of a water spray to cool down the ablation site and the adjacent area. Results show that the temperature can be kept below the critical threshold

  14. Amplitudes and time scales of picosecond-to-microsecond motion in proteins studied by solid-state NMR: a critical evaluation of experimental approaches and application to crystalline ubiquitin

    Energy Technology Data Exchange (ETDEWEB)

    Haller, Jens D.; Schanda, Paul, E-mail: paul.schanda@ibs.fr [Univ. Grenoble Alpes, Institut de Biologie Structurale (IBS) (France)

    2013-10-09

    Solid-state NMR provides insight into protein motion over time scales ranging from picoseconds to seconds. While in solution state the methodology to measure protein dynamics is well established, there is currently no such consensus protocol for measuring dynamics in solids. In this article, we perform a detailed investigation of measurement protocols for fast motions, i.e. motions ranging from picoseconds to a few microseconds, which is the range covered by dipolar coupling and relaxation experiments. We perform a detailed theoretical investigation how dipolar couplings and relaxation data can provide information about amplitudes and time scales of local motion. We show that the measurement of dipolar couplings is crucial for obtaining accurate motional parameters, while systematic errors are found when only relaxation data are used. Based on this realization, we investigate how the REDOR experiment can provide such data in a very accurate manner. We identify that with accurate rf calibration, and explicit consideration of rf field inhomogeneities, one can obtain highly accurate absolute order parameters. We then perform joint model-free analyses of 6 relaxation data sets and dipolar couplings, based on previously existing, as well as new data sets on microcrystalline ubiquitin. We show that nanosecond motion can be detected primarily in loop regions, and compare solid-state data to solution-state relaxation and RDC analyses. The protocols investigated here will serve as a useful basis towards the establishment of a routine protocol for the characterization of ps–μs motions in proteins by solid-state NMR.

  15. Data acquisition on board of test vehicles under severe environmental conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bossmann, G.E.; Tscheuschner, C.

    1985-01-01

    The usage of microprocessors by the metrology of vehicles gives the advantage of performing measurements which become more and more complex. A data acquisition system developed for this special purpose is named MEDAKS - a multiprocessor system in CMOS-technology. Because of its small size and low power requirements MEDAKS is an appropriate instrument for the determination of vehicle parameters during long periods without having an influence on the behaviour of the car. The practical usefulness of MEDAKS is described by means of two examples of application: long-term-tests of catalysts on board of test vehicles with respect to the determination of temperature profiles and the monitoring of critical temperatures and on-line-classifying of fatigue loads due to the rainflow counting algorithm.

  16. Optimization of an on-board imaging system for extremely rapid radiation therapy

    Science.gov (United States)

    Cherry Kemmerling, Erica M.; Wu, Meng; Yang, He; Maxim, Peter G.; Loo, Billy W.; Fahrig, Rebecca

    2015-01-01

    Purpose: Next-generation extremely rapid radiation therapy systems could mitigate the need for motion management, improve patient comfort during the treatment, and increase patient throughput for cost effectiveness. Such systems require an on-board imaging system that is competitively priced, fast, and of sufficiently high quality to allow good registration between the image taken on the day of treatment and the image taken the day of treatment planning. In this study, three different detectors for a custom on-board CT system were investigated to select the best design for integration with an extremely rapid radiation therapy system. Methods: Three different CT detectors are proposed: low-resolution (all 4 × 4 mm pixels), medium-resolution (a combination of 4 × 4 mm pixels and 2 × 2 mm pixels), and high-resolution (all 1 × 1 mm pixels). An in-house program was used to generate projection images of a numerical anthropomorphic phantom and to reconstruct the projections into CT datasets, henceforth called “realistic” images. Scatter was calculated using a separate Monte Carlo simulation, and the model included an antiscatter grid and bowtie filter. Diagnostic-quality images of the phantom were generated to represent the patient scan at the time of treatment planning. Commercial deformable registration software was used to register the diagnostic-quality scan to images produced by the various on-board detector configurations. The deformation fields were compared against a “gold standard” deformation field generated by registering initial and deformed images of the numerical phantoms that were used to make the diagnostic and treatment-day images. Registrations of on-board imaging system data were judged by the amount their deformation fields differed from the corresponding gold standard deformation fields—the smaller the difference, the better the system. To evaluate the registrations, the pointwise distance between gold standard and realistic registration

  17. The study of an ATM switch system used for on-board processing

    Science.gov (United States)

    Li, Yong; Xiong, Huibo

    2007-11-01

    On-board processing (OBP) is one of significant satellite communication technologies, and the Asynchronous Transfer Mode (ATM) is widely used in the OBP which can guarantee the QoS. This article presents the CAC (Call Admission Control) algorithm and Congestion Control algorithm. We combine with B-CAC algorithm, Bahadur-Rao's theory, Weiss theory, to improve the old method, and the simulation results show that when the PDR/LR is small the burst is high, the chain utilization and statistic multiplexing gain get a big advantage. Besides, concerning TCP congestion control, the article compared five strategies: Tahoe, Reno, Newreno, Sack and Vegas. The simulation results show that the Vegas can be used to predict congestion conditions correctly; its congestion window (cwnd) control is smoother and is superior to other algorithms in average RTT.

  18. Modeling Payload Stowage Impacts on Fire Risks On-Board the International Space Station

    Science.gov (United States)

    Anton, Kellie e.; Brown, Patrick F.

    2010-01-01

    The purpose of this presentation is to determine the risks of fire on-board the ISS due to non-standard stowage. ISS stowage is constantly being reexamined for optimality. Non-standard stowage involves stowing items outside of rack drawers, and fire risk is a key concern and is heavily mitigated. A Methodology is needed to account for fire risk due to non-standard stowage to capture the risk. The contents include: 1) Fire Risk Background; 2) General Assumptions; 3) Modeling Techniques; 4) Event Sequence Diagram (ESD); 5) Qualitative Fire Analysis; 6) Sample Qualitative Results for Fire Risk; 7) Qualitative Stowage Analysis; 8) Sample Qualitative Results for Non-Standard Stowage; and 9) Quantitative Analysis Basic Event Data.

  19. Electrostatic Electron Cyclotron Waves Observed by the Plasma Wave Instrument on Board Polar

    Science.gov (United States)

    Menietti, J. D.; Pickett, J. S.; Gurnett, D. A.; Scudder, J. D.

    2001-01-01

    We report the results of an investigation of waves observed by the Polar spacecraft at high altitudes and latitudes and at frequencies just above the cyclotron frequency. These observations are made frequently when the spacecraft is over the polar cap as well as near the dayside cusp and near the nightside auroral region, and observations are made for ratios of plasma frequency to cyclotron frequency, f(sub p)/f(sub c) = 1. Using the six-channel high-frequency waveform receiver (HFWR) on board the spacecraft, which can provide three-axis electric and three-axis magnetic field measurements, we attempt to identify the wavemode of these emissions and investigate possible source mechanisms including low-energy electron beams. We further observe electromagnetic emission associated with upper hybrid waves near and within the plasmasphere. This emission is consistent with both Z and O modes.

  20. Response of TL dosemeters to cosmic radiation on board passenger aircraft

    CERN Document Server

    Bilski, P; Marczewska, B; Olko, P

    2002-01-01

    Measurements were performed with various LiF based TLDs on board seven Polish aircraft, flying long-distance or middle-distance routes. All of the /sup 7/LiF detectors used (various types of /sup 7 /LiF:Mg, Ti and /sup 7/LiF:Mg, Cu, P detectors), which measure the non-neutron component of the radiation field, produced consistent results. It was found that the characteristics of the TLD response (ratio of different detector responses, glow curve shapes) after doses of radiation at flying altitudes differ from those obtained after exposure at the CERN facility (CERF), suggesting a lower contribution of densely ionising radiation. The neutron induced TL signal was also more affected by the thickness of the holder, suggesting the presence of a softer neutron energy spectrum at flight altitudes. Further in-flight and CERF exposures of detectors are planned to resolve these issues. (5 refs).

  1. Proton exchange membrane fuel cells for electrical power generation on-board commercial airplanes.

    Energy Technology Data Exchange (ETDEWEB)

    Curgus, Dita Brigitte; Munoz-Ramos, Karina (Sandia National Laboratories, Albuquerque, NM); Pratt, Joseph William; Akhil, Abbas Ali (Sandia National Laboratories, Albuquerque, NM); Klebanoff, Leonard E.; Schenkman, Benjamin L. (Sandia National Laboratories, Albuquerque, NM)

    2011-05-01

    Deployed on a commercial airplane, proton exchange membrane fuel cells may offer emissions reductions, thermal efficiency gains, and enable locating the power near the point of use. This work seeks to understand whether on-board fuel cell systems are technically feasible, and, if so, if they offer a performance advantage for the airplane as a whole. Through hardware analysis and thermodynamic and electrical simulation, we found that while adding a fuel cell system using today's technology for the PEM fuel cell and hydrogen storage is technically feasible, it will not likely give the airplane a performance benefit. However, when we re-did the analysis using DOE-target technology for the PEM fuel cell and hydrogen storage, we found that the fuel cell system would provide a performance benefit to the airplane (i.e., it can save the airplane some fuel), depending on the way it is configured.

  2. Proton Exchange Membrane Fuel Cells for Electrical Power Generation On-Board Commercial Airplanes

    Energy Technology Data Exchange (ETDEWEB)

    Pratt, Joesph W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Klebanoff, Leonard E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Munoz-Ramos, Karina [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Akhil, Abbas A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Curgus, Dita B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Schenkman, Benjamin L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2011-05-01

    Deployed on a commercial airplane, proton exchange membrane fuel cells may offer emissions reductions, thermal efficiency gains, and enable locating the power near the point of use. This work seeks to understand whether on-board fuel cell systems are technically feasible, and, if so, if they offer a performance advantage for the airplane as a whole. Through hardware analysis and thermodynamic and electrical simulation, we found that while adding a fuel cell system using today’s technology for the PEM fuel cell and hydrogen storage is technically feasible, it will not likely give the airplane a performance benefit. However, when we re-did the analysis using DOE-target technology for the PEM fuel cell and hydrogen storage, we found that the fuel cell system would provide a performance benefit to the airplane (i.e., it can save the airplane some fuel), depending on the way it is configured.

  3. Point-of-care ultrasonography during rescue operations on board a Polish Medical Air Rescue helicopter

    Science.gov (United States)

    Gałązkowski, Robert; Sobczyk, Dorota; Żyła, Zbigniew; Drwiła, Rafał

    2014-01-01

    Point-of-care ultrasound examination has been increasingly widely used in pre-hospital care. The use of ultrasound in rescue medicine allows for a quick differential diagnosis, identification of the most important medical emergencies and immediate introduction of targeted treatment. Performing and interpreting a pre-hospital ultrasound examination can improve the accuracy of diagnosis and thus reduce mortality. The authors’ own experiences are presented in this paper, which consist in using a portable, hand-held ultrasound apparatus during rescue operations on board a Polish Medical Air Rescue helicopter. The possibility of using an ultrasound apparatus during helicopter rescue service allows for a full professional evaluation of the patient's health condition and enables the patient to be brought to a center with the most appropriate facilities for their condition. PMID:26674604

  4. Study of on-board digital FDM-demultiplexing for mobile SCPC satellite communications. I, II

    Science.gov (United States)

    Goeckler, Heinz G.; Eyssele, Helmut

    1992-02-01

    The paper examines three different approaches to FDM demultiplexing, applying digital signal processing, to be used on board a future satellite for mobile communications: the single-stage method (SSM), the polyphase method (PPM), and the hierarchical multistage method (HMM). Basic approaches to FDM demultiplexing are developed for real input and complex output signals, with special attention given to the FDM demultiplexer front end. The SSM of demultiplexing is treated for the odd channel allocation scheme, where all L = L(0) slots can be used; the PPM is treated for the odd and even channel allocation schemes; and the HMM is treated for the odd channel allocation, which is the most appropriate for this approach. A comparison of the three approaches is made.

  5. Implementation of an Integrated On-Board Aircraft Engine Diagnostic Architecture

    Science.gov (United States)

    Armstrong, Jeffrey B.; Simon, Donald L.

    2012-01-01

    An on-board diagnostic architecture for aircraft turbofan engine performance trending, parameter estimation, and gas-path fault detection and isolation has been developed and evaluated in a simulation environment. The architecture incorporates two independent models: a realtime self-tuning performance model providing parameter estimates and a performance baseline model for diagnostic purposes reflecting long-term engine degradation trends. This architecture was evaluated using flight profiles generated from a nonlinear model with realistic fleet engine health degradation distributions and sensor noise. The architecture was found to produce acceptable estimates of engine health and unmeasured parameters, and the integrated diagnostic algorithms were able to perform correct fault isolation in approximately 70 percent of the tested cases

  6. On-board Unit and its Possibilities of Communications on Safety and Security Principles

    Directory of Open Access Journals (Sweden)

    Martin Vaculik

    2008-01-01

    Full Text Available The technical solution of on-board unit (OBU for vehicles used for dangerous good transport and design of vehicle sensor network (based on CAN bus for dangerous good monitoring will be discussed. In presentation the conception of GSM/GPRS networking subsystem for real time data transmission into monitoring centre will be described. Next themes of discussion will be focused on the possibilities of solution of safety-related communication channel for safety sensor network in accordance with standard for functional safety of Electrical / Electronic / Programmable Electronic (E/E/PE systems IEC 61508, recommended methods of risk analysis and possibilities of their modelling and proposal of secure communication channel over GSM/GPRS for secure data transmission into control centre on the base of IPsec protocol.

  7. ASPI experiment: measurements of fields and waves on board the INTERBALL-1 spacecraft

    Directory of Open Access Journals (Sweden)

    S. Klimov

    1997-05-01

    Full Text Available The plasma-wave experiment ASPI (analysis of spectra of plasma waves and instabilities on board the INTERBALL spacecraft is a combined wave diagnostics experiment. It performs measurements of the DC and AC magnetic field vector by flux-gate and search-coil sensors, the DC and AC electric field vector by Langmuir double probes and the plasma current by Langmuir split probe. Preliminary data analysis shows the low noise levels of the sensors and the compatibility of new data with the results of previous missions. During several months of in-orbit operation a rich collection of data was acquired, examples of which at the magnetopause and plasma sheet are presented in second part of the paper.

  8. High-Speed On-Board Data Processing for Science Instruments: HOPS

    Science.gov (United States)

    Beyon, Jeffrey

    2015-01-01

    The project called High-Speed On-Board Data Processing for Science Instruments (HOPS) has been funded by NASA Earth Science Technology Office (ESTO) Advanced Information Systems Technology (AIST) program during April, 2012 â€" April, 2015. HOPS is an enabler for science missions with extremely high data processing rates. In this three-year effort of HOPS, Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) and 3-D Winds were of interest in particular. As for ASCENDS, HOPS replaces time domain data processing with frequency domain processing while making the real-time on-board data processing possible. As for 3-D Winds, HOPS offers real-time high-resolution wind profiling with 4,096-point fast Fourier transform (FFT). HOPS is adaptable with quick turn-around time. Since HOPS offers reusable user-friendly computational elements, its FPGA IP Core can be modified for a shorter development period if the algorithm changes. The FPGA and memory bandwidth of HOPS is 20 GB/sec while the typical maximum processor-to-SDRAM bandwidth of the commercial radiation tolerant high-end processors is about 130-150 MB/sec. The inter-board communication bandwidth of HOPS is 4 GB/sec while the effective processor-to-cPCI bandwidth of commercial radiation tolerant high-end boards is about 50-75 MB/sec. Also, HOPS offers VHDL cores for the easy and efficient implementation of ASCENDS and 3-D Winds, and other similar algorithms. A general overview of the 3-year development of HOPS is the goal of this presentation.

  9. Conformational changes and slow dynamics through microsecond polarized atomistic molecular simulation of an integral Kv1.2 ion channel.

    Directory of Open Access Journals (Sweden)

    Pär Bjelkmar

    2009-02-01

    Full Text Available Structure and dynamics of voltage-gated ion channels, in particular the motion of the S4 helix, is a highly interesting and hotly debated topic in current membrane protein research. It has critical implications for insertion and stabilization of membrane proteins as well as for finding how transitions occur in membrane proteins-not to mention numerous applications in drug design. Here, we present a full 1 micros atomic-detail molecular dynamics simulation of an integral Kv1.2 ion channel, comprising 120,000 atoms. By applying 0.052 V/nm of hyperpolarization, we observe structural rearrangements, including up to 120 degrees rotation of the S4 segment, changes in hydrogen-bonding patterns, but only low amounts of translation. A smaller rotation ( approximately 35 degrees of the extracellular end of all S4 segments is present also in a reference 0.5 micros simulation without applied field, which indicates that the crystal structure might be slightly different from the natural state of the voltage sensor. The conformation change upon hyperpolarization is closely coupled to an increase in 3(10 helix contents in S4, starting from the intracellular side. This could support a model for transition from the crystal structure where the hyperpolarization destabilizes S4-lipid hydrogen bonds, which leads to the helix rotating to keep the arginine side chains away from the hydrophobic phase, and the driving force for final relaxation by downward translation is partly entropic, which would explain the slow process. The coordinates of the transmembrane part of the simulated channel actually stay closer to the recently determined higher-resolution Kv1.2 chimera channel than the starting structure for the entire second half of the simulation (0.5-1 micros. Together with lipids binding in matching positions and significant thinning of the membrane also observed in experiments, this provides additional support for the predictive power of microsecond-scale membrane

  10. An Integrated Architecture for On-Board Aircraft Engine Performance Trend Monitoring and Gas Path Fault Diagnostics

    Science.gov (United States)

    Simon, Donald L.

    2010-01-01

    Aircraft engine performance trend monitoring and gas path fault diagnostics are closely related technologies that assist operators in managing the health of their gas turbine engine assets. Trend monitoring is the process of monitoring the gradual performance change that an aircraft engine will naturally incur over time due to turbomachinery deterioration, while gas path diagnostics is the process of detecting and isolating the occurrence of any faults impacting engine flow-path performance. Today, performance trend monitoring and gas path fault diagnostic functions are performed by a combination of on-board and off-board strategies. On-board engine control computers contain logic that monitors for anomalous engine operation in real-time. Off-board ground stations are used to conduct fleet-wide engine trend monitoring and fault diagnostics based on data collected from each engine each flight. Continuing advances in avionics are enabling the migration of portions of the ground-based functionality on-board, giving rise to more sophisticated on-board engine health management capabilities. This paper reviews the conventional engine performance trend monitoring and gas path fault diagnostic architecture commonly applied today, and presents a proposed enhanced on-board architecture for future applications. The enhanced architecture gains real-time access to an expanded quantity of engine parameters, and provides advanced on-board model-based estimation capabilities. The benefits of the enhanced architecture include the real-time continuous monitoring of engine health, the early diagnosis of fault conditions, and the estimation of unmeasured engine performance parameters. A future vision to advance the enhanced architecture is also presented and discussed

  11. Design and optimization of a fiber optic data link for new generation on-board SAR processing architectures

    Science.gov (United States)

    Ciminelli, Caterina; Dell'Olio, Francesco; Armenise, Mario N.; Iacomacci, Francesco; Pasquali, Franca; Formaro, Roberto

    2017-11-01

    A fiber optic digital link for on-board data handling is modeled, designed and optimized in this paper. Design requirements and constraints relevant to the link, which is in the frame of novel on-board processing architectures, are discussed. Two possible link configurations are investigated, showing their advantages and disadvantages. An accurate mathematical model of each link component and the entire system is reported and results of link simulation based on those models are presented. Finally, some details on the optimized design are provided.

  12. All-digital multicarrier demodulators for on-board processing satellites in mobile communication systems

    Science.gov (United States)

    Yim, Wan Hung

    Economical operation of future satellite systems for mobile communications can only be fulfilled by using dedicated on-board processing satellites, which would allow both cheap earth terminals and lower space segment costs. With on-board modems and codecs, the up-link and down-link can be optimized separately. An attractive scheme is to use frequency-division multiple access/single chanel per carrier (FDMA/SCPC) on the up-link and time division multiplexing (TDM) on the down-link. This scheme allows mobile terminals to transmit a narrow band, low power signal, resulting in smaller dishes and high power amplifiers (HPA's) with lower output power. On the up-link, there are hundreds to thousands of FDM channels to be demodulated on-board. The most promising approach is the use of all-digital multicarrier demodulators (MCD's), where analog and digital hardware are efficiently shared among channels, and digital signal processing (DSP) is used at an early stage to take advantage of very large scale integration (VLSI) implementation. A MCD consists of a channellizer for separation of frequency division multiplexing (FDM) channels, followed by individual modulators for each channel. Major research areas in MCD's are in multirate DSP, and the optimal estimation for synchronization, which form the basis of the thesis. Complex signal theories are central to the development of structured approaches for the sampling and processing of bandpass signals, which are the foundations in both channellizer and demodulator design. In multirate DSP, polyphase theories replace many ad-hoc, tedious and error-prone design procedures. For example, a polyphase-matrix deep space network frequency and timing system (DFT) channellizer includes all efficient filter bank techniques as special cases. Also, a polyphase-lattice filter is derived, not only for sampling rate conversion, but also capable of sampling phase variation, which is required for symbol timing adjustment in all

  13. On-Board Video Recording Unravels Bird Behavior and Mortality Produced by High-Speed Trains

    Directory of Open Access Journals (Sweden)

    Eladio L. García de la Morena

    2017-10-01

    Full Text Available Large high-speed railway (HSR networks are planned for the near future to accomplish increased transport demand with low energy consumption. However, high-speed trains produce unknown avian mortality due to birds using the railway and being unable to avoid approaching trains. Safety and logistic difficulties have precluded until now mortality estimation in railways through carcass removal, but information technologies can overcome such problems. We present the results obtained with an experimental on-board system to record bird-train collisions composed by a frontal recording camera, a GPS navigation system and a data storage unit. An observer standing in the cabin behind the driver controlled the system and filled out a form with data of collisions and bird observations in front of the train. Photographs of the train front taken before and after each journey were used to improve the record of killed birds. Trains running the 321.7 km line between Madrid and Albacete (Spain at speeds up to 250–300 km/h were equipped with the system during 66 journeys along a year, totaling approximately 14,700 km of effective recording. The review of videos produced 1,090 bird observations, 29.4% of them corresponding to birds crossing the infrastructure under the catenary and thus facing collision risk. Recordings also showed that 37.7% bird crossings were of animals resting on some element of the infrastructure moments before the train arrival, and that the flight initiation distance of birds (mean ± SD was between 60 ± 33 m (passerines and 136 ± 49 m (raptors. Mortality in the railway was estimated to be 60.5 birds/km year on a line section with 53 runs per day and 26.1 birds/km year in a section with 25 runs per day. Our results are the first published estimation of bird mortality in a HSR and show the potential of information technologies to yield useful data for monitoring the impact of trains on birds via on-board recording systems. Moreover

  14. OPPORTUNITIES OF ELECTRO-OPTIC VISUALIZATION PRACTICAL APPLICATIONS ON BOARD THE AIRCRAFT

    Directory of Open Access Journals (Sweden)

    Sergey B. Stukalov

    2017-01-01

    Full Text Available The article covers the following issues: the development and practical application of airborne electro-optic systems in the civil aviation aircraft. They provide flight visual information for the pilot day and night in visual and instrument weather conditions. The legal documents establishing the requirements for the application of this type of electro-optic systems in aircraft are presented. The classification of airborne electro-optic systems, commonly named as electronic visualization systems is analyzed. The ways of implementing the recommendations in their construction are considered. There have been analyzed the possibilities of systems of different classes: enhanced vision systems (EVS, synthetic vision systems (SVS, combine vision systems (CVS and on-board vision systems with advanced visualization features, Enhanced Flight Vision Systems (EFVS. It is determined that nowadays EVS systems are considered to be the potential application systems. In order to analyze the possibilities of practical application of such systems in the issues of flight safety at low altitude and landing, flight experiments of the system installed on a light helicopter were conducted. The research introduces the results of flight experiments on the practical work of television and infrared (IR viewing channels of a promising typical system in simple and complex observation conditions. Based on the results of flight experiments, a conclusion can be made about the relevance of practical application of electronic visualization systems on board the aircraft to ensure flight safety. It is determined that the systems can be used in flight both for land observation tasks and ensuring a safe flight. When flying the helicopter at low altitude and landing procedures the pilot should use visual information from the rear hemisphere of the lower tail unit by electro-optical visualization system. It was elicited that in the infrared (IR channel and the fast rotation of

  15. Implementation of the program of quality control of the system on-board imager of varian: initial assessment; Puesta en marcha del programa de control de calidad del sistema on-board imager de varian: evaluacion inicial

    Energy Technology Data Exchange (ETDEWEB)

    Ortega Martin, I.; Ruiz Morales, C.; Lopez Sanchez, F.; Tobarra Gonzalez, B. M.

    2013-07-01

    This work aims to present evidence that are part of our quality control system on-board Imager of Varian, elaborated from recommendations and national and international protocols, as well as a first assessment of the results obtained to date. (Author)

  16. Amaro-autonomous real-time detection of moving maritime objects: introducing a flight experiment for an on-board ship detection system

    Science.gov (United States)

    Schwenk, Kurt; Willburger, Katharina; Pless, Sebastian

    2017-10-01

    Motivated by politics and economy, the monitoring of the world wide ship traffic is a field of high topicality. To detect illegal activities like piracy, illegal fishery, ocean dumping and refugee transportation is of great value. The analysis of satellite images on the ground delivers a great contribution to situation awareness. However, for many applications the up-to-dateness of the data is crucial. With ground based processing, the time between image acquisition and delivery of the data to the end user is in the range of several hours. The highest influence to the duration of ground based processing is the delay caused by the transmission of the large amount of image data from the satellite to the processing centre on the ground. One expensive solution to this issue is the usage of data relay satellites systems like EDRS. Another approach is to analyse the image data directly on-board of the satellite. Since the product data (e.g. ship position, heading, velocity, characteristics) is very small compared to the input image data, real-time connections provided by satellite telecommunication services like Iridium or Orbcomm can be used to send small packets of information directly to the end user without significant delay. The AMARO (Autonomous real-time detection of moving maritime objects) project at DLR is a feasibility study of an on-board ship detection system involving a real-time low bandwidth communication. The operation of a prototype on-board ship detection system will be demonstrated on an airborne platform. In this article, the scope, aim and design of a flight experiment for an on-board ship detection system scheduled for mid of 2018 is presented. First, the scope and the constraints of the experiment are explained in detail. The main goal is to demonstrate the operability of an automatic ship detection system on board of an airplane. For data acquisition the optical high resolution DLR MACS-MARE camera (VIS/NIR) is used. The system will be able to

  17. On-board hydrogen generation for transport applications: the HotSpot™ methanol processor

    Science.gov (United States)

    Edwards, Neil; Ellis, Suzanne R.; Frost, Jonathan C.; Golunski, Stanislaw E.; van Keulen, Arjan N. J.; Lindewald, Nicklas G.; Reinkingh, Jessica G.

    In the absence of a hydrogen infrastructure, development of effective on-board fuel processors is likely to be critical to the commercialisation of fuel-cell cars. The HotSpot™ reactor converts methanol, water and air in a single compact catalyst bed into a reformate containing mainly CO2 and hydrogen (and unreacted nitrogen). The process occurs by a combination of exothermic partial oxidation and endothermic steam reforming of methanol, to produce 750 l of hydrogen per hour from a 245-cm3 reactor. The relative contribution of each reaction can be tuned to match the system requirements at a given time. Scale-up is achieved by the parallel combination of the required number of individual HotSpot reactors, which are fed from a central manifold. Using this modular design, the start-up and transient characteristics of a large fuel-processor are identical to that of a single reactor. When vaporised liquid feed and air are introduced into cold reactors, 100% output is achieved in 50 s; subsequent changes in throughput result in instantaneous changes in output. Surplus energy within the fuel-cell powertrain can be directed to the manifold, where it can be used to vaporise the liquid feeds and so promote steam reforming, resulting in high system efficiency. The small amount of CO that is produced by the HotSpot reactions is attenuated to methanol, but are being applied to other organic fuels.

  18. Hall-effect based semi-fast AC on-board charging equipment for electric vehicles.

    Science.gov (United States)

    Milanés-Montero, María Isabel; Gallardo-Lozano, Javier; Romero-Cadaval, Enrique; González-Romera, Eva

    2011-01-01

    The expected increase in the penetration of electric vehicles (EV) and plug-in hybrid electric vehicles (PHEV) will produce unbalanced conditions, reactive power consumption and current harmonics drawn by the battery charging equipment, causing a great impact on the power quality of the future smart grid. A single-phase semi-fast electric vehicle battery charger is proposed in this paper. This ac on-board charging equipment can operate in grid-to-vehicle (G2V) mode, and also in vehicle-to-grid (V2G) mode, transferring the battery energy to the grid when the vehicle is parked. The charger is controlled with a Perfect Harmonic Cancellation (PHC) strategy, contributing to improve the grid power quality, since the current demanded or injected has no harmonic content and a high power factor. Hall-effect current and voltage transducers have been used in the sensor stage to carry out this control strategy. Experimental results with a laboratory prototype are presented.

  19. The mirror module design for the cryogenic x-ray imaging spectrometer on-board ORIGIN

    DEFF Research Database (Denmark)

    Barbera, Marco; Mineo, Teresa; Basso, Stefano

    2011-01-01

    ORIGIN is a medium size high-energy mission concept submitted to ESA in response to the Cosmic Vision call issued on July 2010. The mission will investigate the evolution of the Universe by performing soft X-ray high resolution spectroscopic measurements of metals formed in different astrophysical...... environments, from the first population III stars at z > 7 to the present large scale structures. The main instrument on-board ORIGIN will be a large format array of TES X-ray micro-calorimeters covering a FOV of 30' at the focal plane of a grazing incidence optical module with a focal length of 2.5 m...... and an angular resolution of 30" HEW at 1 keV. We present the optical module design which is based on hybrid technologies, namely Silicon Pore Optics for the outer section and Ni electro-forming for the inner section, and we present the expected performances based on test measurements and ray-tracing simulations....

  20. Postextraction Separation, On-Board Storage, and Catalytic Conversion of Methane in Natural Gas: A Review.

    Science.gov (United States)

    Saha, Dipendu; Grappe, Hippolyte A; Chakraborty, Amlan; Orkoulas, Gerassimos

    2016-10-12

    In today's perspective, natural gas has gained considerable attention, due to its low emission, indigenous availability, and improvement in the extraction technology. Upon extraction, it undergoes several purification protocols including dehydration, sweetening, and inert rejection. Although purification is a commercially established technology, several drawbacks of the current process provide an essential impetus for developing newer separation protocols, most importantly, adsorption and membrane separation. This Review summarizes the needs of natural gas separation, gives an overview of the current technology, and provides a detailed discussion of the progress in research on separation and purification of natural gas including the benefits and drawbacks of each of the processes. The transportation sector is another growing sector of natural gas utilization, and it requires an efficient and safe on-board storage system. Compressed natural gas (CNG) and liquefied natural gas (LNG) are the most common forms in which natural gas can be stored. Adsorbed natural gas (ANG) is an alternate storage system of natural gas, which is advantageous as compared to CNG and LNG in terms of safety and also in terms of temperature and pressure requirements. This Review provides a detailed discussion on ANG along with computation predictions. The catalytic conversion of methane to different useful chemicals including syngas, methanol, formaldehyde, dimethyl ether, heavier hydrocarbons, aromatics, and hydrogen is also reviewed. Finally, direct utilization of methane onto fuel cells is also discussed.

  1. The High Energy Particle Detector on Board of the China Seismo-Electromagnetic Satellite

    Science.gov (United States)

    Sparvoli, Roberta; Palma, Francesco; Panico, Beatrice; Sotgiu, Alessandro; Vitale, Vincenzo

    2016-08-01

    The study of the Van Allen belts temporal stability is among the main objectives of the China Seismo- Electromagnetic Satellite (CSES) space mission, as well as the study of other electromagnetic disturbances with possible seismic origin. In parallel to this, the CSES mission will address issues of heliospheric and magnetospheric physics, by measuring the cosmic radiation around the Earth.The CSES satellite, developed by a Chinese-Italian collaboration, will be launched in the first half of 2017 and inserted into a circular Sun-synchronous orbit with 98° inclination and 500 km altitude. The expected lifetime is 5 years. CSES hosts several instruments on board: 2 magnetometers, an electric field detector, a plasma analyser, a Langmuir probe and a High-Energy Particle Detector (HEPD). The HEPD detector, responsibility of the Italian side of the CSES collaboration, will measure electrons (3 - 100 MeV) and protons (30 - 300 MeV) along CSES orbit. It consists of a segmented layer of plastic scintillators for the trigger and a calorimeter constituted by a tower of plastic scintillator counters and a LYSO plane. The direction of the incident particle is provided by two planes of double-side silicon micro-strip detectors placed in front of the trigger. Topic of this talk is the technical description of the HEPD and its main characteristics.

  2. An efficient on-board metal-free nanocatalyst for controlled room temperature hydrogen production.

    Science.gov (United States)

    Santra, Saswati; Das, Debanjan; Das, Nirmalya Sankar; Nanda, Karuna Kar

    2017-04-01

    Positively charged functionalized carbon nanodots (CNDs) with a variety of different effective surface areas (ESAs) are synthesized via a cheap and time effective microwave method and applied for the generation of hydrogen via hydrolysis of sodium borohydride. To the best of our knowledge, this is the first report of metal-free controlled hydrogen generation. Our observation is that a positively charged functional group is essential for the hydrolysis for hydrogen production, but the overall activity is found to be enhanced with the ESA. A maximum value of 1066 ml g(-1) min(-1) as the turnover frequency is obtained which is moderate in comparison to other catalysts. However, the optimum activation energy is found to be 22.01 kJ mol(-1) which is comparable to well-known high cost materials like Pt and Ru. All of the samples showed good reusability and 100% conversion even after the 10th cycle. The effect of H(+) and OH(-) is also studied to control the on-board and on-demand hydrogen production ("on-off switching"). It is observed that H2 production decreases inversely with NaOH concentration and ceases completely when 10(-1) M NaOH is added. With the addition of HCl, H2 production can be initiated again, which confirms the on/off control over production.

  3. On-Board Particulate Filter Failure Prevention and Failure Diagnostics Using Radio Frequency Sensing

    Energy Technology Data Exchange (ETDEWEB)

    Sappok, Alex [Filter Sensing Technologies; Ragaller, Paul [Filter Sensing Technologies; Herman, Andrew [CTS Corporation; Bromberg, L. [Massachusetts Institute of Technology (MIT); Prikhodko, Vitaly Y [ORNL; Parks, II, James E [ORNL; Storey, John Morse [ORNL

    2017-01-01

    The increasing use of diesel and gasoline particulate filters requires advanced on-board diagnostics (OBD) to prevent and detect filter failures and malfunctions. Early detection of upstream (engine-out) malfunctions is paramount to preventing irreversible damage to downstream aftertreatment system components. Such early detection can mitigate the failure of the particulate filter resulting in the escape of emissions exceeding permissible limits and extend the component life. However, despite best efforts at early detection and filter failure prevention, the OBD system must also be able to detect filter failures when they occur. In this study, radio frequency (RF) sensors were used to directly monitor the particulate filter state of health for both gasoline particulate filter (GPF) and diesel particulate filter (DPF) applications. The testing included controlled engine dynamometer evaluations, which characterized soot slip from various filter failure modes, as well as on-road fleet vehicle tests. The results show a high sensitivity to detect conditions resulting in soot leakage from the particulate filter, as well as potential for direct detection of structural failures including internal cracks and melted regions within the filter media itself. Furthermore, the measurements demonstrate, for the first time, the capability to employ a direct and continuous monitor of particulate filter diagnostics to both prevent and detect potential failure conditions in the field.

  4. Performance Assessment in the PILOT Experiment On Board Space Stations Mir and ISS.

    Science.gov (United States)

    Johannes, Bernd; Salnitski, Vyacheslav; Dudukin, Alexander; Shevchenko, Lev; Bronnikov, Sergey

    2016-06-01

    The aim of this investigation into the performance and reliability of Russian cosmonauts in hand-controlled docking of a spacecraft on a space station (experiment PILOT) was to enhance overall mission safety and crew training efficiency. The preliminary findings on the Mir space station suggested that a break in docking training of about 90 d significantly degraded performance. Intensified experiment schedules on the International Space Station (ISS) have allowed for a monthly experiment using an on-board simulator. Therefore, instead of just three training tasks as on Mir, five training flights per session have been implemented on the ISS. This experiment was run in parallel but independently of the operational docking training the cosmonauts receive. First, performance was compared between the experiments on the two space stations by nonparametric testing. Performance differed significantly between space stations preflight, in flight, and postflight. Second, performance was analyzed by modeling the linear mixed effects of all variances (LME). The fixed factors space station, mission phases, training task numbers, and their interaction were analyzed. Cosmonauts were designated as a random factor. All fixed factors were found to be significant and the interaction between stations and mission phase was also significant. In summary, performance on the ISS was shown to be significantly improved, thus enhancing mission safety. Additional approaches to docking performance assessment and prognosis are presented and discussed.

  5. Active landslide monitoring using remote sensing data, GPS measurements and cameras on board UAV

    Science.gov (United States)

    Nikolakopoulos, Konstantinos G.; Kavoura, Katerina; Depountis, Nikolaos; Argyropoulos, Nikolaos; Koukouvelas, Ioannis; Sabatakakis, Nikolaos

    2015-10-01

    An active landslide can be monitored using many different methods: Classical geotechnical measurements like inclinometer, topographical survey measurements with total stations or GPS and photogrammetric techniques using airphotos or high resolution satellite images. As the cost of the aerial photo campaign and the acquisition of very high resolution satellite data is quite expensive the use of cameras on board UAV could be an identical solution. Small UAVs (Unmanned Aerial Vehicles) have started their development as expensive toys but they currently became a very valuable tool in remote sensing monitoring of small areas. The purpose of this work is to demonstrate a cheap but effective solution for an active landslide monitoring. We present the first experimental results of the synergistic use of UAV, GPS measurements and remote sensing data. A six-rotor aircraft with a total weight of 6 kg carrying two small cameras has been used. Very accurate digital airphotos, high accuracy DSM, DGPS measurements and the data captured from the UAV are combined and the results are presented in the current study.

  6. New Density Estimates Derived Using Accelerometers On-board the CHAMP and GRACE Satellites

    Science.gov (United States)

    Godinez, H. C.; Mehta, P. M.; Walker, A. C.; Sutton, E. K.

    2016-12-01

    Atmospheric mass densities derived from accelerometers on-board satellites such as CHAMP and GRACE are crucial in gaining insight into open science questions about the dynamic coupling between space weather events and the upper atmosphere. Recent advances in physics-based satellite drag coefficient modeling allow derivation of new density data sets. This paper uses the physics-based satellite drag coefficient models for CHAMP and GRACE to derive new estimates for the neutral atmospheric density. Results show an average difference of 14-18% for CHAMP and 9-24% for GRACE between the new and existing data sets depending on the space weather conditions (i.e. solar and geomagnetic activity levels). The newly derived densities are also compared with existing models and the results are presented. These densities are expected to be useful to the wider scientific community for validating the development of physics-based models and helping to answer open scientific questions regarding our understanding of upper atmosphere dynamics such as the sensitivity of temporal and global density variations to solar and geomagnetic forcing.

  7. Multi-gigabit optical interconnects for next-generation on-board digital equipment

    Science.gov (United States)

    Venet, Norbert; Favaro, Henri; Sotom, Michel; Maignan, Michel; Berthon, Jacques

    2017-11-01

    Parallel optical interconnects are experimentally assessed as a technology that may offer the high-throughput data communication capabilities required to the next-generation on-board digital processing units. An optical backplane interconnect was breadboarded, on the basis of a digital transparent processor that provides flexible connectivity and variable bandwidth in telecom missions with multi-beam antenna coverage. The unit selected for the demonstration required that more than tens of Gbit/s be supported by the backplane. The demonstration made use of commercial parallel optical link modules at 850 nm wavelength, with 12 channels running at up to 2.5 Gbit/s. A flexible optical fibre circuit was developed so as to route board-to-board connections. It was plugged to the optical transmitter and receiver modules through 12-fibre MPO connectors. BER below 10-14 and optical link budgets in excess of 12 dB were measured, which would enable to integrate broadcasting. Integration of the optical backplane interconnect was successfully demonstrated by validating the overall digital processor functionality.

  8. Diagnostics monitor of the braking efficiency in the on board diagnostics system for the motor vehicles

    Science.gov (United States)

    Gajek, Andrzej

    2016-09-01

    The article presents diagnostics monitor for control of the efficiency of brakes in various road conditions in cars equipped with pressure sensor in brake (ESP) system. Now the brake efficiency of the vehicles is estimated periodically in the stand conditions on the base of brake forces measurement or in the road conditions on the base of the brake deceleration. The presented method allows to complete the stand - periodical tests of the brakes by current on board diagnostics system OBD for brakes. First part of the article presents theoretical dependences between deceleration of the vehicle and brake pressure. The influence of the vehicle mass, initial speed of braking, temperature of brakes, aerodynamic drag, rolling resistance, engine resistance, state of the road surface, angle of the road sloping on the deceleration have been analysed. The manner of the appointed of these parameters has been analysed. The results of the initial investigation have been presented. At the end of the article the strategy of the estimation and signalization of the irregular value of the deceleration are presented.

  9. Development of an On-board Failure Diagnostics and Prognostics System for Solid Rocket Booster

    Science.gov (United States)

    Smelyanskiy, Vadim N.; Luchinsky, Dmitry G.; Osipov, Vyatcheslav V.; Timucin, Dogan A.; Uckun, Serdar

    2009-01-01

    We develop a case breach model for the on-board fault diagnostics and prognostics system for subscale solid-rocket boosters (SRBs). The model development was motivated by recent ground firing tests, in which a deviation of measured time-traces from the predicted time-series was observed. A modified model takes into account the nozzle ablation, including the effect of roughness of the nozzle surface, the geometry of the fault, and erosion and burning of the walls of the hole in the metal case. The derived low-dimensional performance model (LDPM) of the fault can reproduce the observed time-series data very well. To verify the performance of the LDPM we build a FLUENT model of the case breach fault and demonstrate a good agreement between theoretical predictions based on the analytical solution of the model equations and the results of the FLUENT simulations. We then incorporate the derived LDPM into an inferential Bayesian framework and verify performance of the Bayesian algorithm for the diagnostics and prognostics of the case breach fault. It is shown that the obtained LDPM allows one to track parameters of the SRB during the flight in real time, to diagnose case breach fault, and to predict its values in the future. The application of the method to fault diagnostics and prognostics (FD&P) of other SRB faults modes is discussed.

  10. Electromagnetic Field Interference on Transmission Lines due to On-Board Antenna

    Directory of Open Access Journals (Sweden)

    Heekwon Lee

    2015-01-01

    Full Text Available As the available space in the board of a mobile device becomes smaller and more compact, circuit elements and transmission lines are arranged in very close proximity, especially from the antennas which are usually installed on the same board. Due to the various on-board antennas which are designed in small space, the transmission lines on the board are electromagnetically interfered, resulting in the performance degradation of the circuit. So the engineers and circuit designers should find the least interfered place for the transmission lines and components to minimize the electromagnetic interferences. This paper discusses and presents a methodology to find the least sensitive position in the induced current distribution as well as in the noise power delivered from the antenna. For this purpose some vertical, horizontal, and bent transmission lines with antenna on the same board are designed and fabricated with and without common ground, and the transferred powers to the transmission lines were measured and were also simulated using a full-wave simulator. The results predicted by the EM simulation model were successfully confirmed through the measurement of S-parameters in the experimental setup, which shows the validness of the suggested analysis method.

  11. Hall-Effect Based Semi-Fast AC On-Board Charging Equipment for Electric Vehicles

    Science.gov (United States)

    Milanés-Montero, María Isabel; Gallardo-Lozano, Javier; Romero-Cadaval, Enrique; González-Romera, Eva

    2011-01-01

    The expected increase in the penetration of electric vehicles (EV) and plug-in hybrid electric vehicles (PHEV) will produce unbalanced conditions, reactive power consumption and current harmonics drawn by the battery charging equipment, causing a great impact on the power quality of the future smart grid. A single-phase semi-fast electric vehicle battery charger is proposed in this paper. This ac on-board charging equipment can operate in grid-to-vehicle (G2V) mode, and also in vehicle-to-grid (V2G) mode, transferring the battery energy to the grid when the vehicle is parked. The charger is controlled with a Perfect Harmonic Cancellation (PHC) strategy, contributing to improve the grid power quality, since the current demanded or injected has no harmonic content and a high power factor. Hall-effect current and voltage transducers have been used in the sensor stage to carry out this control strategy. Experimental results with a laboratory prototype are presented. PMID:22163697

  12. Practical on-board weigh-in-motion system for commercial vehicles

    Science.gov (United States)

    Kenyon, Chase H.

    1997-01-01

    Many commercial carriers are currently operating vehicles which are overweight, creating an unsafe and illegal situation. However, the cost to law enforcement agencies to stop vehicles for roadside weight checks is prohibitive, while the cost to the nation in lost travel time adds shipping costs which are reflected in the price of every product transported by truck. Overweight trucks also become a threat to public safety when, on public highways, solid cargo breaks loose or liquid cargo leaks. The solution is an on-board monitoring system. With such a system, trucks under their legal weight limit would be allowed to travel past state borders and checkpoints without being stopped. THis would save money both in law enforcement and shipping costs to the nation as a whole. A properly designed system would also have the capability to warn both the driver and local safety and enforcement personnel when the truck is loaded beyond capacity or any other unsafe condition. This paper will detail a system that would even in early limited production be cost effective for both the law enforcement agencies and the operators of trucking fleets. In full production the systems would be cost effective even for smaller or owner/operator trucks. This is a safety system that could become standard equipment similar to seat belts, ABS, and airbags. The initial testing of sub-assemblies and sub-systems which could be deployed now for beta test has been completed.

  13. SXI: The Soft X-ray Imager on Board of the EXIST Mission

    Science.gov (United States)

    Tagliaferri, Gianpiero; Natalucci, L.; Basso, S.; Bazzano, A.; Caraveo, P.; Conconi, P.; Grindlay, J. E.; Pareschi, G.; Ubertini, P.; Uslenghi, M.; Villa, G.

    2010-01-01

    The Soft X-ray Imager (SXI), sensitive in the 0.1-10 keV band, is a X-ray telescope foreseen on board of the EXIST mission. SXI is proposed as a contribution of ASI, the Italian space agency, and it is fully developed by Italian institutes. The current optical design is based on 26 mirror-shells and provides an effective area comparable to one XMM-Newton mirror module up to 3 keV and somewhat lower from 3 to 10 keV. The realization of these shells is based on the well-proven Nichel replication-process technology. We present the optical design of the SXI mirror module and describe its characteristics in term of effective area and imaging capability, summarizing also the characteristics of the full SXI telescope. Acknowledgement: the study of the SXI telescope in Italy is carried out at the INAF-OABr, INAF-IASF_Milano and INAF-IASF_Roma Institutes and is financed by the Italian Space Agency under the ASI contract I/088/06/0.

  14. Acceleration levels on board the Space Station and a tethered elevator for micro and variable-gravity applications

    Science.gov (United States)

    Lorenzini, E. C.; Cosmo, M.; Vetrella, S.; Moccia, A.

    1988-01-01

    This paper investigates the dynamics and acceleration levels of a new tethered system for micro and variable-gravity applications. The system consists of two platforms tethered on opposite sides to the Space Station. A fourth platform, the elevator, is placed in between the Space Station and the upper platform. Variable-g levels on board the elevator are obtained by moving this facility along the upper tether, while micro-g experiments are carried out on board the Space Station. By controlling the length of the lower tether the position of the system CM can be maintained on board the Space Station despite variations of the station's distribution of mass. The paper illustrates the mathematical model, the environmental perturbations and the control techniques which have been adopted for the simulation and control of the system dynamics. Two sets of results from two different simulation runs are shown. The first set shows the system dynamics and the acceleration spectra on board the Space Station and the elevator during station-keeping. The second set of results demonstrates the capability of the elevator to attain a preselected g-level.

  15. Predicting adult pulmonary ventilation volume and wearing complianceby on-board accelerometry during personal level exposure assessments

    Science.gov (United States)

    Rodes, C. E.; Chillrud, S. N.; Haskell, W. L.; Intille, S. S.; Albinali, F.; Rosenberger, M. E.

    2012-09-01

    BackgroundMetabolic functions typically increase with human activity, but optimal methods to characterize activity levels for real-time predictions of ventilation volume (l min-1) during exposure assessments have not been available. Could tiny, triaxial accelerometers be incorporated into personal level monitors to define periods of acceptable wearing compliance, and allow the exposures (μg m-3) to be extended to potential doses in μg min-1 kg-1 of body weight? ObjectivesIn a pilot effort, we tested: 1) whether appropriately-processed accelerometer data could be utilized to predict compliance and in linear regressions to predict ventilation volumes in real-time as an on-board component of personal level exposure sensor systems, and 2) whether locating the exposure monitors on the chest in the breathing zone, provided comparable accelerometric data to other locations more typically utilized (waist, thigh, wrist, etc.). MethodsPrototype exposure monitors from RTI International and Columbia University were worn on the chest by a pilot cohort of adults while conducting an array of scripted activities (all ventilation volumes in-situ. For the subset of participants with complete data (n = 22), linear regressions were constructed (processed accelerometric variable versus ventilation rate) for each participant and exposure monitor type, and Pearson correlations computed to compare across scenarios. ResultsTriaxial accelerometer data were demonstrated to be adequately sensitive indicators for predicting exposure monitor wearing compliance. Strong linear correlations (R values from 0.77 to 0.99) were observed for all participants for both exposure sensor accelerometer variables against ventilation volume for recumbent, sedentary, and ambulatory activities with MET values ˜side wrist location (R = 0.57; p = 0.016). ConclusionsEven with a modest number of adult volunteers, the consistency and linearity of regression slopes for all subjects were very good with excellent

  16. Sailing for Science: on board experiences for transferring knowledge on Historical Oceanography for Future Innovation

    Science.gov (United States)

    Garvani, Sara; Carmisciano, Cosmo; Locritani, Marina; Grossi, Luigi; Mori, Anna; Stroobant, Mascha; Schierano, Erika; De Strobel, Federico; Manzella, Giuseppe; Muzi, Enrico; Leccese, Dario; Sinapi, Luigi; Morellato, Claudio; La Tassa, Hebert; Talamoni, Roberta; Coelho, Emanuel; Nacini, Francesca

    2017-04-01

    culture witnesses, related to the naval history of seamanship from the origins up to nowadays), allowed the creation of a special educational format based on Historical Oceanography, for university and high school students as an integration for their curriculum. The Historical Oceanography Society has provided the major knowledges included in the ancient volumes of its archive, thanks to the availability of its members that also held theoretical and practical lessons during the course. The present paper will describe the one-week special course (about 60 hours of theory and practice with technical visits to Research centres and Museums) that has been planned to be carried out on board of the Italian Training Navy Ship (A. Vespucci) and has been organized in order to give the hints about on board life, as well as theoretical lessons on modern and historical oceanography, hands-on labs on oceanographic instruments from public and private collections, physiology of diving techniques and astronomy. The general aim of this course has been, hence, to give to excellent students all those technological but also creative and imaginative features of our past. References M. Locritani, I. Batzu, C. Carmisciano, F. Muccini, R. Talamoni, H.L. Tassa, M. Stroobant, G. Guccinelli, L. Benvenuti, M. Abbate, S. Furia, A. Benedetti, M.I. Bernardini, R. Centi, L. Casale, C. Vannucci, F. Giacomazzi, C. Marini, D. Tosi, S. Merlino, E. Mioni, F. Nacini, Feeling the pulse of public perception of science: Does research make our hearts beat faster?, in: MTS/IEEE OCEANS 2015 - Genova: Discovering Sustainable Ocean Energy for a New World, 2015. National Science Foundation, 50 Years of Ocean Discovery: National Science Foundation 1950-2000. Ocean Studies Board, National Research Council ISBN: 0-309-51744-3, 276 pages, 8.5 x 11, 2000. E.L. Mills, The Historian of Science and Oceanography After Twenty Years, Earth Sciences History. 12 (1993) 5-18. J.A. Bennett, History of Technology - McConnell Anita

  17. A line-source method for aligning on-board and other pinhole SPECT systems

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Susu [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27710 (United States); Bowsher, James; Yin, Fang-Fang [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27710 and Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States)

    2013-12-15

    Purpose: In order to achieve functional and molecular imaging as patients are in position for radiation therapy, a robotic multipinhole SPECT system is being developed. Alignment of the SPECT system—to the linear accelerator (LINAC) coordinate frame and to the coordinate frames of other on-board imaging systems such as cone-beam CT (CBCT)—is essential for target localization and image reconstruction. An alignment method that utilizes line sources and one pinhole projection is proposed and investigated to achieve this goal. Potentially, this method could also be applied to the calibration of the other pinhole SPECT systems.Methods: An alignment model consisting of multiple alignment parameters was developed which maps line sources in three-dimensional (3D) space to their two-dimensional (2D) projections on the SPECT detector. In a computer-simulation study, 3D coordinates of line-sources were defined in a reference room coordinate frame, such as the LINAC coordinate frame. Corresponding 2D line-source projections were generated by computer simulation that included SPECT blurring and noise effects. The Radon transform was utilized to detect angles (α) and offsets (ρ) of the line-source projections. Alignment parameters were then estimated by a nonlinear least squares method, based on the α and ρ values and the alignment model. Alignment performance was evaluated as a function of number of line sources, Radon transform accuracy, finite line-source width, intrinsic camera resolution, Poisson noise, and acquisition geometry. Experimental evaluations were performed using a physical line-source phantom and a pinhole-collimated gamma camera attached to a robot.Results: In computer-simulation studies, when there was no error in determining angles (α) and offsets (ρ) of the measured projections, six alignment parameters (three translational and three rotational) were estimated perfectly using three line sources. When angles (α) and offsets (ρ) were provided by

  18. On-board autonomous attitude maneuver planning for planetary spacecraft using genetic algorithms

    Science.gov (United States)

    Kornfeld, Richard P.

    2003-01-01

    A key enabling technology that leads to greater spacecraft autonomy is the capability to autonomously and optimally slew the spacecraft from and to different attitudes while operating under a number of celestial and dynamic constraints. The task of finding an attitude trajectory that meets all the constraints is a formidable one, in particular for orbiting or fly-by spacecraft where the constraints and initial and final conditions are of time-varying nature. This paper presents an approach for attitude path planning that makes full use of a priori constraint knowledge and is computationally tractable enough to be executed on-board a spacecraft. The approach is based on incorporating the constraints into a cost function and using a Genetic Algorithm to iteratively search for and optimize the solution. This results in a directed random search that explores a large part of the solution space while maintaining the knowledge of good solutions from iteration to iteration. A solution obtained this way may be used 'as is' or as an initial solution to initialize additional deterministic optimization algorithms. A number of example simulations are presented including the case examples of a generic Europa Orbiter spacecraft in cruise as well as in orbit around Europa. The search times are typically on the order of minutes, thus demonstrating the viability of the presented approach. The results are applicable to all future deep space missions where greater spacecraft autonomy is required. In addition, onboard autonomous attitude planning greatly facilitates navigation and science observation planning, benefiting thus all missions to planet Earth as well.

  19. A N2-Raman lidar on board ULA for Arctic atmospheric studies

    Science.gov (United States)

    de Cacqueray, Victor; Chazette, Patrick; Totems, Julien; Raut, Jean-Christophe; Shang, Xiaoxia; Marpillat, Alexandre

    2016-04-01

    A key scientific question relative to atmospheric studies in the Arctic is the quantification and the vertical distribution of aerosols and their interactions with clouds in the lower troposphere. In May 2016, as part of the PARCS (Pollution in the ARCtic System) project, we will conduct an experiment in order to assess the optical properties and concentrations of aerosols near the North-Cape in Norway. This campaign will involve a new airborne N2-Raman lidar (355 nm) on board an Ultra Light Aircraft (ULA) and an original instrumental synergy between ground-based radar (95 GHz) and N2-H2O Raman lidar. The airborne experimental preparation for this campaign was divided in two weeks: the first week of experiments above the Rhône valley in June 2015 and the second in the Maurienne valley in the French Alps in December 2015. The capability of the N2-Raman lidar to perform measurements from the ULA during daytime has been checked. After the first campaign of tests, the laser emitted energy per pulse has been upgraded to improve the signal to noise ratio. Both the strategies and the main results of the two field campaigns will be presented. We will focus on the error budget for the retrieval of the aerosol optical thickness in the first atmospheric kilometer. We will present in addition the potential of such a lidar to monitor industrial pollution plumes in the planetary boundary layer. The airborne lidar measurements will be analysed taking into account the synergy with an in situ particle sizer (FIDAS) provided by the ADDAIR Company.

  20. On-board fuel vapor recovery system having improved canister purging

    Energy Technology Data Exchange (ETDEWEB)

    Gillier, W.C.

    1993-08-24

    An on-board fuel vapor recovery system is described for a fuel system of an internal combustion engine of an automotive vehicle comprising a canister in which volatile fuel vapors are collected, a canister purge solenoid (CPS) valve comprising an inlet port, an outlet port, a valve member controlling flow between the inlet port and the outlet port, resilient bias means resiliently biasing the valve member to close the CPS valve to flow between the inlet port and the outlet port, and a solenoid for operating the valve member, means placing the inlet port in communication with the canister, means placing the outlet port in communication with an intake manifold of the internal combustion engine, means placing the solenoid under the control of an electrical control system that controls the purging of the canister to the intake manifold, the CPS valve's solenoid comprising a relatively magnetically permeable stator, the valve member comprising a relatively magnetically permeable armature, the stator and the armature being disposed to have confronting faces defining an air gap across which the stator exerts magnetic attraction force on the armature for operating the valve member against opposite force of the resilient bias means to open the CPS valve to flow between the inlet port and the outlet port when the solenoid is energized by electric current from the electrical control system, the intensity of the magnetic force and hence the extent to which the valve member opens the CPS valve to flow between the inlet port and the outlet port being related to the intensity of the electric current from the electrical control system, in that the confronting faces of the stator and the armature are shaped to congruently complement each other with one comprising an intrusion that congruently complements a protrusion on the other, and in that the resilient bias means is disposed other than between the confronting faces.

  1. Some Results of the Educational Experiment APIS (Cervantes Mission on Board ISS)

    Science.gov (United States)

    Fajardo, Pablo; Barahona, Sergio; Sanz-Andres, Angel

    2009-07-01

    Some results of the analysis of the pictures taken along the performance of the Análisis de Propiedades Inerciales de Sólidos, Analysis of the Inertia Properties of Solid Bodies (APIS) experiment carried out in the Cervantes mission on board ISS, are presented. APIS was an educational experiment devoted to take advantage of the unique conditions of absence of relative gravity forces of a space platform such as ISS, to show some of the characteristics of the free rotational motion of a solid body, which are impossible to carry out on earth. This field of experimental research has application to aerospace engineering science (e.g. attitude control of spacecrafts), to astrophysical sciences (e.g. state of rotation and tumbling motions of asteroids) and to engineering education. To avoid the effect of the ambient atmosphere loads on the motion, the test body is placed inside a sphere, which reduces the effect of the aerodynamic forces to just friction. The drastic reduction of the effect of the surrounding air during the short duration of the experimental sequences allows us to compare the actual motion with the known solutions for the solid body rotation in vacuum. In this paper, some selected, relevant sequences of the sphere enclosing a body with a nominal cylindrical inertia tensor, put into rotation by the astronaut, are shown; the main problems to extract the information concerning the characteristic parameters of the motion are outlined, and some of the results obtained concerning the motion of the test probe are included, which show what seems to be a curious and unexpected solution of the Euler equations for the solid body rotation in vacuum, without energy dissipation, when the angular momentum is almost perpendicular to the axisymmetry axis.

  2. OH Airglow and Equatorial Variations Observed by ISUAL Instrument on Board the FORMOSAT 2 Satellite

    Directory of Open Access Journals (Sweden)

    Jan-Bai Nee

    2010-01-01

    Full Text Available OH airglow observed by the ISUAL (Imager of Sprites and Upper Atmospheric Lightning instrument on board the FORMOSAT 2 satellite is reported in this paper. The satellite is sun-synchronous and it returns to the same orbit at the same local time daily. By using this property, we can study the upper atmosphere in detail. With a CCD camera, ISUAL has measured the emission layers of OH Meinel band at 630 nm for several two-week periods in 2004 and 2007 in equatorial regions. ISUAL images are snapshots of the atmosphere 250 km (height ¡_ 1200 km (horizontal distance. These images of OH airglow are analyzed to derive its peak height and latitudinal variations. ISUAL observation is unique in its capability of continuous observation of the upper atmosphere as the satellite travels from south to north along a specific orbit. However, 630 nm filter also measured O(1D at 200 km, and there are interferences between O(1D and OH airglows as as observed from a distance in space. We have studied the overlap of two airglows by simulations, and our final analyses show that OH airglow can be correctly derived with its average peak height of 89 ¡_ 2.1 km usually lying within ¡_10¢X latitude about the equator. ISUAL data reveal detailed structures of equatorial OH airglow such as the existences of a few secondary maxima within the equatorial regions, and the oscillations of the peak latitudes. These results are discussed and compared with previous reports.

  3. The TUS Detector of Extreme Energy Cosmic Rays on Board the Lomonosov Satellite

    Science.gov (United States)

    Klimov, P. A.; Panasyuk, M. I.; Khrenov, B. A.; Garipov, G. K.; Kalmykov, N. N.; Petrov, V. L.; Sharakin, S. A.; Shirokov, A. V.; Yashin, I. V.; Zotov, M. Y.; Biktemerova, S. V.; Grinyuk, A. A.; Grebenyuk, V. M.; Lavrova, M. V.; Tkachev, L. G.; Tkachenko, A. V.; Park, I. H.; Lee, J.; Jeong, S.; Martinez, O.; Salazar, H.; Ponce, E.; Saprykin, O. A.; Botvinko, A. A.; Senkovsky, A. N.; Puchkov, A. E.

    2017-11-01

    The origin and nature of extreme energy cosmic rays (EECRs), which have energies above the 5\\cdot10^{19} eV—the Greisen-Zatsepin-Kuzmin (GZK) energy limit, is one of the most interesting and complicated problems in modern cosmic-ray physics. Existing ground-based detectors have helped to obtain remarkable results in studying cosmic rays before and after the GZK limit, but have also produced some contradictions in our understanding of cosmic ray mass composition. Moreover, each of these detectors covers only a part of the celestial sphere, which poses problems for studying the arrival directions of EECRs and identifying their sources. As a new generation of EECR space detectors, TUS (Tracking Ultraviolet Set-up), KLYPVE and JEM-EUSO, are intended to study the most energetic cosmic-ray particles, providing larger, uniform exposures of the entire celestial sphere. The TUS detector, launched on board the Lomonosov satellite on April 28, 2016 from Vostochny Cosmodrome in Russia, is the first of these. It employs a single-mirror optical system and a photomultiplier tube matrix as a photo-detector and will test the fluorescent method of measuring EECRs from space. Utilizing the Earth's atmosphere as a huge calorimeter, it is expected to detect EECRs with energies above 10^{20} eV. It will also be able to register slower atmospheric transient events: atmospheric fluorescence in electrical discharges of various types including precipitating electrons escaping the magnetosphere and from the radiation of meteors passing through the atmosphere. We describe the design of the TUS detector and present results of different ground-based tests and simulations.

  4. The TUS Detector of Extreme Energy Cosmic Rays on Board the Lomonosov Satellite

    Science.gov (United States)

    Klimov, P. A.; Panasyuk, M. I.; Khrenov, B. A.; Garipov, G. K.; Kalmykov, N. N.; Petrov, V. L.; Sharakin, S. A.; Shirokov, A. V.; Yashin, I. V.; Zotov, M. Y.; Biktemerova, S. V.; Grinyuk, A. A.; Grebenyuk, V. M.; Lavrova, M. V.; Tkachev, L. G.; Tkachenko, A. V.; Park, I. H.; Lee, J.; Jeong, S.; Martinez, O.; Salazar, H.; Ponce, E.; Saprykin, O. A.; Botvinko, A. A.; Senkovsky, A. N.; Puchkov, A. E.

    2017-08-01

    The origin and nature of extreme energy cosmic rays (EECRs), which have energies above the 5\\cdot10^{19} eV—the Greisen-Zatsepin-Kuzmin (GZK) energy limit, is one of the most interesting and complicated problems in modern cosmic-ray physics. Existing ground-based detectors have helped to obtain remarkable results in studying cosmic rays before and after the GZK limit, but have also produced some contradictions in our understanding of cosmic ray mass composition. Moreover, each of these detectors covers only a part of the celestial sphere, which poses problems for studying the arrival directions of EECRs and identifying their sources. As a new generation of EECR space detectors, TUS (Tracking Ultraviolet Set-up), KLYPVE and JEM-EUSO, are intended to study the most energetic cosmic-ray particles, providing larger, uniform exposures of the entire celestial sphere. The TUS detector, launched on board the Lomonosov satellite on April 28, 2016 from Vostochny Cosmodrome in Russia, is the first of these. It employs a single-mirror optical system and a photomultiplier tube matrix as a photo-detector and will test the fluorescent method of measuring EECRs from space. Utilizing the Earth's atmosphere as a huge calorimeter, it is expected to detect EECRs with energies above 10^{20} eV. It will also be able to register slower atmospheric transient events: atmospheric fluorescence in electrical discharges of various types including precipitating electrons escaping the magnetosphere and from the radiation of meteors passing through the atmosphere. We describe the design of the TUS detector and present results of different ground-based tests and simulations.

  5. The estimation of the pollutant emissions on-board vessels by means of numerical methods

    Science.gov (United States)

    Jenaru, A.; Arsenie, P.; Hanzu-Pazara, R.

    2016-08-01

    Protection of the environment, especially within the most recent years, has become a constant problem considered by the states and the governments of the world, which are more and more concerned about the serious problems caused by the continuous deterioration of the environment. The long term effects of pollution on the environment generated by the lack of penalty regulations, have directed the attention of statesmen upon the necessity of the elaboration of normative acts meant to be effective in the continuous fight with it. Maritime transportation generates approximately 4% of the total of the CO2 emissions produced by human activities. This paper is intended to present two methods of estimation of the gases emissions on-board a vessel, methods that are very useful for the crews which are exploiting them. For the determination and the validation of these methods we are going to use the determinations from the tank ship. This ship has as a main propulsion engine Wärtsilä DU Sulzer RT Flex 50 - 6 cylinders that develops a maximal power of 9720 kW and has a permanent monitoring system of the pollutant emissions. The methods we develop here are using the values of the polluting elements from the exhaust gases that are determined at the exit of the vessel from the ship yard, in the framework of the acceptance tests. These values have been introduced within the framework of a matrix in the MATHCAD program. This matrix represents the starting point of the two mentioned methods: the analytical method and the graphical method. During the study we are going to evaluate the development and validation of an analytical tool to be used to determine the standard of emissions aimed at thermal machines on ships. One of the main objectives of this article represents an objective assessment of the expediency of using non-fuels for internal combustion engines in vessels.

  6. Sub-microsecond temporal evolution of edge density during edge localized modes in KSTAR tokamak plasmas inferred from ion cyclotron emission

    Science.gov (United States)

    Chapman, B.; Dendy, R. O.; McClements, K. G.; Chapman, S. C.; Yun, G. S.; Thatipamula, S. G.; Kim, M. H.

    2017-12-01

    During edge localised mode (ELM) crashes in KSTAR deuterium plasmas, bursts of spectrally structured ion cyclotron emission (ICE) are detected. Usually the ICE spectrum chirps downwards during an ELM crash, on sub-microsecond timescales. For KSTAR ICE where the separation of spectral peak frequencies is close to the proton cyclotron frequency Ω_cp at the outer plasma edge, we show that the driving population of energetic ions is likely to be a subset of the 3 MeV fusion protons, born centrally on deeply passing orbits which drift from the core to the edge plasma. We report first principles modelling of this scenario using a particle-in-cell code, which evolves the full orbit dynamics of large numbers of energetic protons, thermal deuterons, and electrons self-consistently with the electric and magnetic fields. The Fourier transform of the excited fields in the nonlinear saturated regime of the simulations is the theoretical counterpart to the measured ICE spectra. Multiple simulation runs for different, adjacent, values of the plasma density under KSTAR edge conditions enable us to infer the theoretical dependence of ICE spectral structure on the local electron number density. By matching this density dependence to the observed time-dependence of chirping ICE spectra in KSTAR, we obtain sub-microsecond time resolution of the evolving local electron number density during the ELM crash.

  7. Transiting Exoplanet Survey Satellite (TESS) Community Observer Program including the Science Enhancement Option Box (SEO Box) - 12 TB On-board Flash Memory for Serendipitous Science

    Science.gov (United States)

    Schingler, Robert; Villasenor, J. N.; Ricker, G. R.; Latham, D. W.; Vanderspek, R. K.; Ennico, K. A.; Lewis, B. S.; Bakos, G.; Brown, T. M.; Burgasser, A. J.; Charbonneau, D.; Clampin, M.; Deming, L. D.; Doty, J. P.; Dunham, E. W.; Elliot, J. L.; Holman, M. J.; Ida, S.; Jenkins, J. M.; Jernigan, J. G.; Kawai, N.; Laughlin, G. P.; Lissauer, J. J.; Martel, F.; Sasselov, D. D.; Seager, S.; Torres, G.; Udry, S.; Winn, J. N.; Worden, S. P.

    2010-01-01

    The Transiting Exoplanet Survey Satellite (TESS) will perform an all-sky survey in a low-inclination, low-Earth orbit. TESS's 144 GB of raw data collected each orbit will be stacked, cleaned, cut, compressed and downloaded. The Community Observer Program is a Science Enhancement Option (SEO) that takes advantage of the low-radiation environment, technology advances in flash memory, and the vast amount of astronomical data collected by TESS. The Community Observer Program requires the addition of a 12 TB "SEO Box” inside the TESS Bus. The hardware can be built using low-cost Commercial Off-The-Shelf (COTS) components and fits within TESS's margins while accommodating GSFC gold rules. The SEO Box collects and stores a duplicate of the TESS camera data at a "raw” stage ( 4.3 GB/orbit, after stacking and cleaning) and makes them available for on-board processing. The sheer amount of onboard storage provided by the SEO Box allows the stacking and storing of several months of data, allowing the investigator to probe deeper in time prior to a given event. Additionally, with computation power and data in standard formats, investigators can utilize data-mining techniques to investigate serendipitous phenomenon, including pulsating stars, eclipsing binaries, supernovae or other transient phenomena. The Community Observer Program enables ad-hoc teams of citizen scientists to propose, test, refine and rank algorithms for on-board analysis to support serendipitous science. Combining "best practices” of online collaboration, with careful moderation and community management, enables this `crowd sourced’ participatory exploration with a minimal risk and impact on the core TESS Team. This system provides a powerful and independent tool opening a wide range of opportunity for science enhancement and secondary science. Support for this work has been provided by NASA, the Kavli Foundation, Google, and the Smithsonian Institution.

  8. High dynamic range imaging sensors and architectures

    CERN Document Server

    Darmont, Arnaud

    2013-01-01

    Illumination is a crucial element in many applications, matching the luminance of the scene with the operational range of a camera. When luminance cannot be adequately controlled, a high dynamic range (HDR) imaging system may be necessary. These systems are being increasingly used in automotive on-board systems, road traffic monitoring, and other industrial, security, and military applications. This book provides readers with an intermediate discussion of HDR image sensors and techniques for industrial and non-industrial applications. It describes various sensor and pixel architectures capable

  9. A semi-empirical approach for the modelling and analysis of microvibration sources on-board spacecraft

    Science.gov (United States)

    Addari, Daniele

    The term microvibrations generally refers to accelerations in the order of micro-gs and which manifest in a bandwidth from a few Hz up to say 500-1000 Hz. The need to accurately characterise this small disturbances acting on-board modern satellites, thus allowing the design of dedicated minimisation and control systems, is nowadays a major concern for the success of some space missions. The main issues related to microvibrations are the feasibility to analytically describe the microvibration sources using a series of analysis tools and test experiments and the prediction of how the dynamics of the microvibration sources couple with those of the satellite structure. In this thesis, a methodology to facilitate the modelling of these phenomena is described. Two aspects are investigated: the characterisation of the microvibration sources with a semi-empirical procedure which allows derivation of the dynamic mass properties of the source, also including the gyroscopic effect, with a significantly simpler test configuration and lower computational effort compared to traditional approaches; and the modelling of the coupled dynamics when the source is mounted on a representative supporting structure of a spacecraft, including the passive and active effects of the source, which allows prediction of the structure response at any location. The methodology has been defined conducting an extensive study, both experimental and numerical, on a reaction wheel assembly, as this is usually identified as the main contributory factor among all microvibration sources. The contributions to the state-of-the-art made during this work include: i) the development of a cantilever configured reaction wheel analytical model able to reproduce all the configurations in which the mechanism may operate and inclusive of the gyroscopic effect; ii) the reformulation of the coupling theory which allows retrieving the dynamic mass of a microvibration source over a wide range of frequencies and speeds

  10. Development of a novel sweeping Langmuir probe instrument for monitoring the upper ionosphere on board a pico-satellite

    Science.gov (United States)

    Ranvier, Sylvain; De Keyser, Johan; Cardoen, Pepijn; Pieroux, Didier

    2014-05-01

    A novel Langmuir probe instrument, which will fly on board the Pico-Satellite for Atmospheric and Space Science Observations (PICASSO), is under development at the Belgian Institute for Space Aeronomy. PICASSO was initiated to join the QB50 project as scientific in-orbit demonstrator. The sweeping Langmuir probe (SLP) instrument is designed to measure both plasma density and electron temperature at an altitude varying from about 400 km up to 700 km from a high inclination orbit. Therefore, the plasma density is expected to fluctuate over a wide range, from about 1e6/m³ at high latitude and high altitude up to 1e12/m³ at low/mid latitude and low altitude. The electron temperature is expected to lie between approximately 1000 K and 3000 K. Given the high inclination of the orbit, the SLP instrument will allow a global monitoring of the ionosphere with a maximum spatial resolution of the order of 150 m. The main goals are to study 1) the ionosphere-plasmasphere coupling, 2) the subauroral ionosphere and corresponding magnetospheric features, 3) auroral structures, 4) polar caps, and 5) ionospheric dynamics via coordinated observations with EISCAT's heating radar. To achieve the scientific objectives described above, the instrument includes four thin cylindrical probes whose electrical potential is swept in such a way that both plasma density and electron temperature can be derived. In addition, since at least two probes will be out of the spacecraft's wake at any given time, differential measurements can be performed to increase the accuracy. Along the orbit, the Debye length is expected to vary from a few millimetres up to a few meters. Due to the tight constraints in terms of mass and volume inherent to pico-satellites, the use of long booms, which would guarantee that the probes are outside the sheath of the spacecraft (several Debye lengths away), is not possible. Consequently, the probes might be in the sheath of the spacecraft in polar regions. Extensive

  11. Can space ties on board GNSS satellites replace terrestrial ties in the implementation of Terrestrial Reference Frames?

    Science.gov (United States)

    Bruni, Sara; Zerbini, Susanna; Altamimi, Zuheir; Rebischung, Paul; Errico, Maddalena; Santi, Efisio

    2016-04-01

    The realization of Terrestrial Reference Frames (TRFs) must be periodically updated in order to account for newly acquired observations and for upgrades in data analysis procedures and/or combination techniques. Any innovative computation strategy should ameliorate the definition of the frame physical parameters, upon which a number of scientific applications critically rely. On the basis of the requirements of scientific cutting edge studies, the geodetic community has estimated that the present day challenge in the determination of TRFs is to provide a frame that is accurate and long-term stable at the level of 1 mm and 0.1 mm/y respectively. This work aims at characterizing the frame realized by a combination of Satellite Laser Ranging (SLR) and Global Navigation Satellite Systems (GNSS) observations via their co-location on board GNSS spacecrafts. In particular, it is established how such a frame compares to the traditional ITRF computation and what is the impact on the realization of the frame origin and scale. Four years of data from a global network encompassing about one hundred GNSS stations and all SLR sites have been analyzed. In order to ensure the highest possible consistency, the raw data of both techniques are treated with the same analysis Software (Bernese GNSS Software 5.2) following IERS2010 Conventions. Both weekly and long term solutions are carried out exploiting either the Bernese or the Combination and Analysis of Terrestrial Reference Frames (CATREF) Software packages. We present the results of a combination study involving GNSS data and SLR observations to the two LAGEOS and to the GNSS satellites equipped with retroreflector arrays. The latter type of measurements is currently not included in the computation of the official ITRF solutions. The assessment of the benefit that they could provide to the definition of the origin and scale of the ITRF is however worth investigating, as such data provide the potential for linking the GNSS and

  12. Testing the associations between different aspects of seafarers' employment contract and on-board internet access and their job and life satisfaction and health.

    Science.gov (United States)

    Slišković, Ana; Penezić, Zvjezdan

    2016-12-01

    The aim of this study was to test for associations between different aspects of contract and on-board internet access and seafarers' satisfaction and health. Altogether 298 Croatian seafarers, all officers, employed on cargo ships, with a minimum work experience of two years with their current shipping company, participated in an online survey. The questionnaire included sociodemographic items, questions relating to their employment contract and internet access, and measures of job satisfaction, life satisfaction, mental health, and gastrointestinal and cardiovascular symptoms. Their job- and lifesatisfaction levels were higher for shorter duration on board, favourable ratio of work to non-work days, and compliance with the employment contract regarding the changes to work and non-work days. Mental health differed likewise but only in relation to two aspects of the contract: on-board duration and compliance with the contract. The level of gastrointestinal symptoms was lower in cases of shorter on-board duration and compliance with the contract, and in seafarers who have free, unlimited internet access on board. Lower level of cardiovascular symptoms was found in seafarers with free, unlimited internet access on board. Our findings suggest that in promoting satisfaction and health in seafaring, attention should be given to reducing on-board duration, compliance with the contract, and internet accessibility on board.

  13. A Dedicated dual energy X-ray tomography/radiography equipment on-board of R/V Mare Nigrum

    Energy Technology Data Exchange (ETDEWEB)

    Iovea, M.; Neagu, M. [Accent Pro 2000, Ltd, Bucharest (Romania); Duliu, O.G. [Bucharest Univ., Dept. of Atomic and Nuclear Physics (Romania); Oaie, G. [National Institute of Marine Geology and Geoecology, Bucharet (Romania); Mateiasi, G. [Bucharest Politehnica Univ. (Romania)

    2007-07-01

    An X-ray dual-energy computer tomograph provided with a double set of X-ray detectors arrays separated by a copper foil was projected, assembled and commissioned to be used on-board of the R/V Mare Nigrum. By using a variant of filtered back projections reconstruction algorithm together with a set of calibrated standard samples, it was possible do determine on-board and with a precision of 3.5 % the density and 2.5 % the effective atomic number distribution of various unconsolidated sediments core. The same computer tomograph was used to obtain free of parallax dual energy digital radiography, allowing a spatial resolution of about 0.5 mm. (authors)

  14. Energy management in modern vehicle on-board electrics; Energiemanagement in heutigen Fahrzeugbordnetzen. Zunehmende Elektrifizierung heutiger Fahrzeuge erfordert intelligentes Energiemanagement

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, M. [Robert Bosch GmbH, Stuttgart (Germany); Theuerkauf, H. [Universitaet Kassel, Kassel (Germany)

    2008-07-01

    This article takes a look at the increasing electrification of modern vehicles and the intelligent energy-management system necessary to control the electrical systems in modern vehicles. According to the author, the increasing electrical power requirements of modern vehicles and an insufficient increase in generator power are leading to a significant increase in battery failures. The requirements of the on-board electrical systems have a significant influence on the fuel consumption of vehicles and, consequently, on CO{sub 2} emissions. On-board electrical topology, generators used and battery management are examined and the associated fuel consumption commented on. Various energy management systems are commented on, as are twin-voltage electrical supply systems.

  15. Controlling Small Fixed Wing UAVs to Optimize Image Quality from On-Board Cameras

    Science.gov (United States)

    Jackson, Stephen Phillip

    Small UAVs have shown great promise as tools for collecting aerial imagery both quickly and cheaply. Furthermore, using a team of small UAVs, as opposed to one large UAV, has shown promise as being a cheaper, faster and more robust method for collecting image data over a large area. Unfortunately, the autonomy of small UAVs has not yet reached the point where they can be relied upon to collect good aerial imagery without human intervention, or supervision. The work presented here intends to increase the level of autonomy of small UAVs so that they can independently, and reliably collect quality aerial imagery. The main contribution of this paper is a novel approach to controlling small fixed wing UAVs that optimizes the quality of the images captured by cameras on board the aircraft. This main contribution is built on three minor contributions: a kinodynamic motion model for small fixed wing UAVs, an iterative Gaussian sampling strategy for rapidly exploring random trees, and a receding horizon, nonlinear model predictive controller for controlling a UAV's sensor footprint. The kinodynamic motion model is built on the traditional unicycle model of an aircraft. In order to create dynamically feasible paths, the kinodynamic motion model augments the kinetic unicycle model by adding a first order estimate of the aircraft's roll dynamics. Experimental data is presented that not only validates this novel kinodynamic motion model, but also shows a 25% improvement over the traditional unicycle model. A novel Gaussian biased sampling strategy is presented for building a rapidly exploring random tree that quickly iterates to a near optimal path. This novel sampling strategy does not require a method for calculating the nearest node to a point, which means that it runs much faster than the traditional RRT algorithm, but it still results in a Gaussian distribution of nodes. Furthermore, because it uses the kinodynamic motion model, the near optimal path it generates is, by

  16. Software-type Wave-Particle Interaction Analyzer on board the Arase satellite

    Science.gov (United States)

    Katoh, Yuto; Kojima, Hirotsugu; Hikishima, Mitsuru; Takashima, Takeshi; Asamura, Kazushi; Miyoshi, Yoshizumi; Kasahara, Yoshiya; Kasahara, Satoshi; Mitani, Takefumi; Higashio, Nana; Matsuoka, Ayako; Ozaki, Mitsunori; Yagitani, Satoshi; Yokota, Shoichiro; Matsuda, Shoya; Kitahara, Masahiro; Shinohara, Iku

    2018-01-01

    We describe the principles of the Wave-Particle Interaction Analyzer (WPIA) and the implementation of the Software-type WPIA (S-WPIA) on the Arase satellite. The WPIA is a new type of instrument for the direct and quantitative measurement of wave-particle interactions. The S-WPIA is installed on the Arase satellite as a software function running on the mission data processor. The S-WPIA on board the Arase satellite uses an electromagnetic field waveform that is measured by the waveform capture receiver of the plasma wave experiment (PWE), and the velocity vectors of electrons detected by the medium-energy particle experiment-electron analyzer (MEP-e), the high-energy electron experiment (HEP), and the extremely high-energy electron experiment (XEP). The prime objective of the S-WPIA is to measure the energy exchange between whistler-mode chorus emissions and energetic electrons in the inner magnetosphere. It is essential for the S-WPIA to synchronize instruments to a relative time accuracy better than the time period of the plasma wave oscillations. Since the typical frequency of chorus emissions in the inner magnetosphere is a few kHz, a relative time accuracy of better than 10 μs is required in order to measure the relative phase angle between the wave and velocity vectors. In the Arase satellite, a dedicated system has been developed to realize the time resolution required for inter-instrument communication. Here, both the time index distributed over all instruments through the satellite system and an S-WPIA clock signal are used, that are distributed from the PWE to the MEP-e, HEP, and XEP through a direct line, for the synchronization of instruments within a relative time accuracy of a few μs. We also estimate the number of particles required to obtain statistically significant results with the S-WPIA and the expected accumulation time by referring to the specifications of the MEP-e and assuming a count rate for each detector.

  17. X-ray facility for the ground calibration of the X-ray monitor JEM-X on board INTEGRAL

    DEFF Research Database (Denmark)

    Loffredo, G.; Pelliciari, C.; Frontera, F.

    2003-01-01

    We describe the X-ray facility developed for the calibration of the X-ray monitor JEM-X on board the INTEGRAL satellite. The apparatus allowed the scanning of the detector geometric area with a pencil beam of desired energy over the major part of the passband of the instrument. The monochromatic...... radiation is obtained with the use of a double crystal monochromator at fixed exit. We discuss the facility performance....

  18. System Research Of Multi-Barrel Machine Guns Installed On Board Of The Helicopter Of Mi-17 Type

    Directory of Open Access Journals (Sweden)

    Bęczkowski Grzegorz

    2015-08-01

    Full Text Available This article presents tests of a multi-barreled machine gun system built on board of a helicopter. The described weapon system consists of three 7.62 mm M-134G multi-barreled machine guns built on the designed frames of shooting positions located in the escape hatch window, the side doors and the rear doors of the transport cabin of the Mi-17-1V helicopter.

  19. Chip-on-board assembly of 800V Si L-IGBTs for high performance ultra-compact LED drivers

    OpenAIRE

    Aliyu, Attahir Murtala; Mouawad, Bassem; Castellazzi, Alberto; P. Rajaguru; BAILEY, C; Pathirana, V.; Udugampola, N.; Trajkovic, T.; Udrea, F.

    2017-01-01

    This paper presents a novel chip on board assembly design for an integrated power switch, based on high power density 800V silicon lateral insulated-gate bipolar transistor (Si LIGBT) technology. LIGBTs offer much higher current densities (5-10X), significantly lower leakage currents, and lower parasitic device capacitances and, gate charge compared to conventional vertical MOSFETs commonly used in LED drivers. The higher voltage ratings offered (up to 1kV), the development of high voltage in...

  20. Combined on-board hydride slurry storage and reactor system and process for hydrogen-powered vehicles and devices

    Science.gov (United States)

    Brooks, Kriston P; Holladay, Jamelyn D; Simmons, Kevin L; Herling, Darrell R

    2014-11-18

    An on-board hydride storage system and process are described. The system includes a slurry storage system that includes a slurry reactor and a variable concentration slurry. In one preferred configuration, the storage system stores a slurry containing a hydride storage material in a carrier fluid at a first concentration of hydride solids. The slurry reactor receives the slurry containing a second concentration of the hydride storage material and releases hydrogen as a fuel to hydrogen-power devices and vehicles.

  1. High spatiotemporal resolution pollutant measurements of on-board vehicle emissions using ultra-fast response gas analyzers

    OpenAIRE

    Irwin, Martin; Bradley, Harry; Duckhouse, Matthew; Hammond, Matthew; Peckham, Mark S.

    2017-01-01

    Existing ultra-fast response engine exhaust emissions analyzers have been adapted for on-board vehicle use combined with GPS data. We present, for the first time, how high spatiotemporal resolution data products allow transient features associated with internal combustion engines to be examined in detail during on-road driving. Such data is both useful to examine the circumstances leading to high emissions, and reveals the accurate position of urban air quality “hot spots” as deposited by the...

  2. A Semi-empirical approach for the modelling and analysis of microvibration sources on-board spacecraft.

    OpenAIRE

    Addari, Daniele

    2017-01-01

    The term microvibrations generally refers to accelerations in the order of micro-gs and which manifest in a bandwidth from a few Hz up to say 500-1000 Hz. The need to accurately characterise this small disturbances acting on-board modern satellites, thus allowing the design of dedicated minimisation and control systems, is nowadays a major concern for the success of some space missions. The main issues related to microvibrations are the feasibility to analytically describe the microvibrat...

  3. Application of On-Board Evolutionary Algorithms to Underwater Robots to Optimally Replan Missions with Energy Constraints

    Directory of Open Access Journals (Sweden)

    M. L. Seto

    2012-01-01

    Full Text Available The objective is to show that on-board mission replanning for an AUV sensor coverage mission, based on available energy, enhances mission success. Autonomous underwater vehicles (AUVs are tasked to increasingly long deployments, consequently energy management issues are timely and relevant. Energy shortages can occur if the AUV unexpectedly travels against stronger currents, is not trimmed for the local water salinity has to get back on course, and so forth. An on-board knowledge-based agent, based on a genetic algorithm, was designed and validated to replan a near-optimal AUV survey mission. It considers the measured AUV energy consumption, attitudes, speed over ground, and known response to proposed missions through on-line dynamics and control predictions. For the case studied, the replanned mission improves the survey area coverage by a factor of 2 for an energy budget, that is, a factor of 2 less than planned. The contribution is a novel on-board cognitive capability in the form of an agent that monitors the energy and intelligently replans missions based on energy considerations with evolutionary methods.

  4. Working conditions in the engine department - A qualitative study among engine room personnel on board Swedish merchant ships.

    Science.gov (United States)

    Lundh, Monica; Lützhöft, Margareta; Rydstedt, Leif; Dahlman, Joakim

    2011-01-01

    The specific problems associated with the work on board within the merchant fleet are well known and have over the years been a topic of discussion. The work conditions in the engine room (ER) are demanding due to, e.g. the thermal climate, noise and awkward working postures. The work in the engine control room (ECR) has over recent years undergone major changes, mainly due to the introduction of computers on board. In order to capture the impact these changes had implied, and also to investigate how the work situation has developed, a total of 20 engine officers and engine ratings were interviewed. The interviews were semi-structured and Grounded Theory was used for the data analysis. The aim of the present study was to describe how the engine crew perceive their work situation and working environment on board. Further, the aim was to identify areas for improvements which the engine crew consider especially important for a safe and effective work environment. The result of the study shows that the design of the ECR and ER is crucial for how different tasks are performed. Design which does not support operational procedures and how tasks are performed risk inducing inappropriate behaviour as the crew members' are compelled to find alternative ways to perform their tasks in order to get the job done. These types of behaviour can induce an increased risk of exposure to hazardous substances and the engine crew members becoming injured. Copyright © 2010 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  5. Robonaut 2 - IVA Experiments On-Board ISS and Development Towards EVA Capability

    Science.gov (United States)

    Diftler, Myron; Hulse, Aaron; Badger, Julia; Thackston, Allison; Rogers, Jonathan

    2014-01-01

    Robonaut 2 (R2) has completed its fixed base activities on-board the ISS and is scheduled to receive its climbing legs in early 2014. In its continuing line of firsts, the R2 torso finished up its on-orbit activities on its stanchion with the manipulation of space blanket materials and performed multiple tasks under teleoperation control by IVA astronauts. The successful completion of these two IVA experiments is a key step in Robonaut's progression towards an EVA capability. Integration with the legs and climbing inside the ISS will provide another important part of the experience that R2 will need prior to performing tasks on the outside of ISS. In support of these on-orbit activities, R2 has been traversing across handrails in simulated zero-g environments and working with EVA tools and equipment on the ground to determine manipulation strategies for an EVA Robonaut. R2 made significant advances in robotic manipulation of deformable materials in space while working with its softgoods task panel. This panel features quarter turn latches that secure a space blanket to the task panel structure. The space blanket covers two cloth cubes that are attached with Velcro to the structure. R2 was able to open and close the latches, pull back the blanket, and remove the cube underneath. R2 simulated cleaning up an EVA worksite as well, by replacing the cube and reattaching the blanket. In order to interact with the softgoods panel, R2 has both autonomously and with a human in the loop identified and localized these deformable objects. Using stereo color cameras, R2 identified characteristic elements on the softgoods panel then extracted the location and orientation of the object in its field of view using stereo disparity and kinematic transforms. R2 used both vision processing and supervisory control to successfully accomplish this important task. Teleoperation is a key capability for Robonaut's effectiveness as an EVA system. To build proficiency, crewmembers have

  6. COVE, MARINA, and the Future of On-Board Processing (OBP) Platforms for CubeSat Science Missions

    Science.gov (United States)

    Pingree, P.; Bekker, D. L.; Bryk, M.; DeLucca, J.; Franklin, B.; Hancock, B.; Klesh, A. T.; Meehan, C.; Meshkaty, N.; Nichols, J.; Peay, C.; Rider, D. M.; Werne, T.; Wu, Y.

    2012-12-01

    The CubeSat On-board processing Validation Experiment (COVE), JPL's first CubeSat payload launched on October 28, 2011, features the Xilinx Virtex-5QV Single event Immune Reconfigurable FPGA (SIRF). The technology demonstration mission was to validate the SIRF device running an on-board processing (OBP) algorithm developed to reduce the data set by 2-orders of magnitude for the Multi-angle SpectroPolarimetric Imager (MSPI), an instrument under development at JPL (PI: D. Diner). COVE has a single data interface to the CubeSat flight computer that is used to transfer a static image taken from the CubeSat camera and store it to local memory where the FPGA then reads it to run the algorithm on it. In the next generation COVE design, called MARINA, developed for the GRIFEX CubeSat project, the OBP board is extended, using rigid-flex PCB technology, to provide an interface to a JPL-developed Read-Out Integrated Circuit (ROIC) hybridized to a detector developed by Raytheon. In this configuration the focal plane array (FPA) data can be streamed directly to the FPGA for data processing or for storage to local memory. The MARINA rigid-flex PCB design is integrated with a commercial camera lens to create a 1U instrument payload for integration with a CubeSat under development by the University of Michigan and planned for launch in 2014. In the GRIFEX technology demonstration, the limited on-board storage capacity is filled by high-rate FPA data in less than a second. The system is also limited by the CubeSat downlink data rate and several ground station passes are required to transmit this limited amount of data. While this system is sufficient to validate the ROIC technology on-orbit, the system cannot be operated in a way to perform continuous science observations due to the on-board storage and data downlink constraints. In order to advance the current platform to support sustained science observations, more on-board storage is needed. Radiation tolerant memory

  7. Catalytic on-board hydrogen production from methanol and ammonia for mobile application

    Energy Technology Data Exchange (ETDEWEB)

    Soerijanto, H.

    2008-08-15

    This PhD thesis deals with the catalytic hydrogen production for mobile application, for example for the use in fuel cells for electric cars. Electric powered buses with fuel cells as driving system are well known, but the secure hydrogen storage in adequate amounts for long distance drive is still a topic of discussion. Methanol is an excellent hydrogen carrier. First of all it has a high H:C ratio and therefore a high energy density. Secondly the operating temperature of steam reforming of methanol is comparatively low (250 C) and there is no risk of coking since methanol has no C-C bond. Thirdly methanol is a liquid, which means that the present gasoline infrastructure can be used. For the further development of catalysts and for the construction of a reformer it is very important to characterize the catalysts very well. For the dimensioning and the control of an on-board production of hydrogen it is essential to draw accurately on the thermodynamic, chemical and kinetic data of the reaction. At the first part of this work the mesoporous Cu/ZrO{sub 2}/CeO{sub 2}-catalysts with various copper contents were characterized and their long-term stability and selectivity were investigated, and the kinetic data were determined. Carbon monoxide is generated by reforming of carbon containing material. This process is undesired since CO poisons the Pt electrode of the fuel cell. The separation of hydrogen by metal membranes is technically feasible and a high purity of hydrogen can be obtained. However, due to their high density this procedure is not favourable because of its energy loss. In this study a concept is presented, which enables an autothermal mode by application of ceramic membrane and simultaneously could help to deal with the CO problem. The search for an absolutely selective catalyst is uncertain. The production of CO can be neither chemically nor thermodynamically excluded, if carbon is present in the hydrogen carrier. Since enrichment or separation are

  8. Chip-on-Board Technology 1996 Year-end Report (Design, Manufacturing, and Reliability Study)

    Science.gov (United States)

    Le, Binh Q.; Nhan, Elbert; Maurer, Richard H.; Lew, Ark L.; Lander, Juan R.

    1996-01-01

    The major impetus for flight qualifying Chip-On-Board (COB) packaging technology is the shift in emphasis for space missions to smaller, better, and cheaper spacecraft and satellites resulting from the NASA New Millenium initiative and similar requirements in DoD-sponsored programs. The most important benefit that can potentially be derived from miniaturizing spacecraft and satellites is the significant cost saving realizable if a smaller launch vehicle may be employed. Besides the program cost saving, there are several other advantages to building COB-based space hardware. First, once a well-controlled process is established, COB can be low cost compared to standard Multi-Chip Module (MCM) technology. This cost competitiveness is regarded as a result of the generally greater availability and lower cost of Known Good Die (KGD). Coupled with the elimination of the first level of packaging (chip package), compact, high-density circuit boards can be realized with Printed Wiring Boards (PWB) that can now be made with ever-decreasing feature size in line width and via hole. Since the COB packaging technique in this study is based mainly on populating bare dice on a suitable multi-layer laminate substrate which is not hermetically sealed, die coating for protection from the environment is required. In recent years, significant improvements have been made in die coating materials which further enhance the appeal of COB. Hysol epoxies, silicone, parylene and silicon nitride are desirable because of their compatible Thermal Coefficient of Expansion (TCE) and good moisture resistant capability. These die coating materials have all been used in the space and other industries with varying degrees of success. COB technology, specifically siliconnitride coated hardware, has been flown by Lockheed on the Polar satellite. In addition, DARPA has invested a substantial amount of resources on MCM and COB-related activities recently. With COB on the verge of becoming a dominant player

  9. Probing Microsecond Time Scale Dynamics in Proteins by Methyl H-1 Carr-Purcell-Meiboom-Gill Relaxation Dispersion NMR Measurements. Application to Activation of the Signaling Protein NtrC(r)

    NARCIS (Netherlands)

    Otten, Renee; Villali, Janice; Kern, Dorothee; Mulder, Frans A. A.

    2010-01-01

    To study microsecond processes by relaxation dispersion NMR spectroscopy, low power deposition and short pulses are crucial and encourage the development of experiments that employ H-1 Carr-Purcell-Meiboom-Gill (CPMG) pulse trains. Herein, a method is described for the comprehensive study of

  10. PICASSO-SLP: a Langmuir probe instrument for monitoring the upper ionosphere on board a pico-satellite

    Science.gov (United States)

    Ranvier, Sylvain; Anciaux, Michel; Cardoen, Pepijn; Gamby, Emmanuel; Bonnewijn, Sabrina; De Keyser, Johan; Echim, Marius; Pieroux, Didier

    2016-04-01

    A novel Langmuir probe instrument, which will fly on board the Pico-Satellite for Atmospheric and Space Science Observations (PICASSO), is under development at the Royal Belgian Institute for Space Aeronomy. PICASSO, an ESA in-orbit demonstrator, is a triple unit CubeSat of dimensions 340.5x100x100 mm. The sweeping Langmuir probe (SLP) instrument, which includes four thin cylindrical probes whose electrical potential is swept, is designed to measure both plasma density and electron temperature at an altitude varying from about 400 km up to 700 km from a high inclination orbit. Therefore, the plasma density is expected to fluctuate over a wide range, from about 1e8/m³ at high latitude and high altitude up to several times 1e12/m³ at low/mid latitude and low altitude. The electron temperature is expected to lie between approximately 1.000 K and 10.000 K. Given the high inclination of the orbit, the SLP instrument will allow a global monitoring of the ionosphere with a maximum spatial resolution of the order of 150 m for the electron density and temperature, and up to a few meters for electron density only. The main goals are to study 1) the ionosphere-plasmasphere coupling, 2) the subauroral ionosphere and corresponding magnetospheric features, 3) auroral structures, 4) polar caps, 5) for the density, the multi-scale behaviour, spectral properties and turbulence of processes typical for the auroral regions, and 6) ionospheric dynamics via coordinated observations with EISCAT's heating radar. Along the orbit, the Debye length is expected to vary from a few millimetres up to a few meters. Due to the tight constraints in terms of mass and volume inherent to pico-satellites, the use of long booms, which would guarantee that the probes are outside the sheath of the spacecraft (several Debye lengths away), is not possible. Consequently, the probes might be in the sheath of the spacecraft in polar regions. Extensive modelling and simulations of the sheath effects on the

  11. The HIA instrument on board the Tan Ce 1 Double Star near-equatorial spacecraft and its first results

    Directory of Open Access Journals (Sweden)

    H. Rème

    2005-11-01

    Full Text Available On 29 December 2003, the Chinese spacecraft Tan Ce 1 (TC-1, the first component of the Double Star mission, was successfully launched within a low-latitude eccentric orbit. In the framework of the scientific cooperation between the Academy of Sciences of China and ESA, several European instruments, identical to those developed for the Cluster spacecraft, were installed on board this spacecraft.

    The HIA (Hot Ion Analyzer instrument on board the TC-1 spacecraft is an ion spectrometer nearly identical to the HIA sensor of the CIS instrument on board the 4 Cluster spacecraft. This instrument has been specially adapted for TC-1. It measures the 3-D distribution functions of the ions between 5 eV/q and 32 keV/q without mass discrimination.

    TC-1 is like a fifth Cluster spacecraft to study the interaction of the solar wind with the magnetosphere and to study geomagnetic storms and magnetospheric substorms in the near equatorial plane.

    HIA was commissioned in February 2004. Due to the 2 RE higher apogee than expected, some in-flight improvements were needed in order to use HIA in the solar wind in the initial phase of the mission. Since this period HIA has obtained very good measurements in the solar wind, the magnetosheath, the dayside and nightside plasma sheet, the ring current and the radiation belts. We present here the first results in the different regions of the magnetosphere and in the solar wind. Some of them are very new and include, for example, ion dispersion structures in the bow shock and ion beams close to the magnetopause. The huge interest in the orbit of TC-1 is strongly demonstrated.

  12. The HIA instrument on board the Tan Ce 1 Double Star near-equatorial spacecraft and its first results

    Directory of Open Access Journals (Sweden)

    H. Rème

    2005-11-01

    Full Text Available On 29 December 2003, the Chinese spacecraft Tan Ce 1 (TC-1, the first component of the Double Star mission, was successfully launched within a low-latitude eccentric orbit. In the framework of the scientific cooperation between the Academy of Sciences of China and ESA, several European instruments, identical to those developed for the Cluster spacecraft, were installed on board this spacecraft. The HIA (Hot Ion Analyzer instrument on board the TC-1 spacecraft is an ion spectrometer nearly identical to the HIA sensor of the CIS instrument on board the 4 Cluster spacecraft. This instrument has been specially adapted for TC-1. It measures the 3-D distribution functions of the ions between 5 eV/q and 32 keV/q without mass discrimination. TC-1 is like a fifth Cluster spacecraft to study the interaction of the solar wind with the magnetosphere and to study geomagnetic storms and magnetospheric substorms in the near equatorial plane. HIA was commissioned in February 2004. Due to the 2 RE higher apogee than expected, some in-flight improvements were needed in order to use HIA in the solar wind in the initial phase of the mission. Since this period HIA has obtained very good measurements in the solar wind, the magnetosheath, the dayside and nightside plasma sheet, the ring current and the radiation belts. We present here the first results in the different regions of the magnetosphere and in the solar wind. Some of them are very new and include, for example, ion dispersion structures in the bow shock and ion beams close to the magnetopause. The huge interest in the orbit of TC-1 is strongly demonstrated.

  13. The HIA instrument on board the Tan Ce 1 Doubler Star near-equatorial spacecraft and its first results

    Energy Technology Data Exchange (ETDEWEB)

    Reme, H.; Dandouras, I. [Centre d' Etude Spatiale des Rayonnements (CESR), Toulouse (France); Aoustin, C. [Centre d' Etude Spatiale des Rayonnements (CESR), Toulouse (FR)] [and others

    2005-07-01

    On 29 December 2003, the Chinese spacecraft Tan Ce 1 (TC-1), the first component of the Double Star mission, was successfully launched within a low-latitude eccentric orbit. In the framework of the scientific cooperation between the Academy of Sciences of China and ESA, several European instruments, identical to those developed for the Cluster spacecraft, were installed on board this spacecraft. The HIA (Hot Ion Analyzer) instrument on board the TC-1 spacecraft is an ion spectrometer nearly identical to the HIA sensor of the CIS instrument on board the 4 Cluster spacecraft. This instrument has been specially adapted for TC-1. It measures the 3-D distribution functions of the ion between 5 eV/q and 32 keV/q without mass discrimination. TC-1 is like a fifth Cluster spacecraft to study the interaction of the solar wind with the magnetosphere and to study geomagnetic storms and magnetospheric substorms in the near equatorial plane. HIA was commissioned in February 2004. Due to the 2 R{sub E} higher apogee than expected, some in-flight improvements were needed in order to use HIA in the solar wind in the initial phase of the mission. Since this period HIA has obtained very good measurements in the solar wind, the magnetosheath, the dayside and nightside plasma sheet, the ring current and the radiation belts. We present here the first results in the different regions of the magnetosphere and in the solar wind. Some of them are very new and include, for example, ion dispersion structures in the bow shock and ion beams close to the magnetopause. The huge interest in the orbit of TC-1 is strongly demonstrated. (orig.)

  14. Preparing an autonomous, low-cost GNSS positioning and timing function on board a GEO telecom mission: a study case

    Science.gov (United States)

    Zin, A.; Scotti, M.; Mangolini, E.; Cappelluti, I.; Fiordiponti, R.; Amalric, J.; Flament, P.; Brouillard, E.; Kowaltschek, S.

    2015-06-01

    The purpose of this paper is to present a viable solution for a low-cost, autonomous GNSS positioning and timing function integrated in the avionics of a GEO telecomm satellite. This paper is based on a study currently carried out by Thales Alenia Space under an ARTES contract with ESA, funded by the Italian Space Agency. The availability of an autonomous means of positioning in GEO platform is essential in reducing the constraints on the ground control. This is even more true in the case of the transfer to the GEO orbit, where the current trend is to implement the low-thrust electrical propulsion and this phase could have a duration of months: the GNSS function can autonomously feed the on-board trajectory propagator with the spacecraft position fixes, in order to constrain the state estimate of the on-board filter. In order to achieve large availability of position and timing of the hosting platform, the tracking of the GNSS antenna side lobes is a critical feature. Based on the recent experiences of SGR GEO, additional insights on the side-lobe levels were made available to the GNSS community and this allows to better target a receiver architecture whose performance can be more precisely determined for the study case. This paper will show the findings in terms of GNSS function architecture for the GEO application, as well as the integration of this function inside the avionic computer. The focus is on a single frequency receiver, targeting at least GPS L1 and Galileo E1 signals. Optimizations in terms of sharing of HW resources with the on-board computer (oscillator, DC/DC converter) and the overall redundancy strategy are presented. Extension and implications for covering to the GTO case is presented as well. The expected receiver performances (position and timing accuracy, autonomy) are provided through in-orbit simulations, including a realistic receiver model.

  15. Optical design of a street lamp based on dual-module chip-on-board LED arrays.

    Science.gov (United States)

    Ge, Aiming; Cai, Jinlin; Chen, Dehua; Shu, Hongyun; Qiu, Peng; Wang, Junwei; Zhu, Ling

    2014-09-01

    We design and propose a compact street lamp based on dual-module chip-on-board LED. The street lamp is composed of six faceted reflectors. It can direct the luminous flux and form uniform illumination on the target area, and it effectively reduces power consumption. We have conducted both simulations and prototype measurements. The test results show good optical performance in that the uniformity of luminance reaches 0.58 for LED lamp zigzag arrangements and 0.60 for LED lamp double-side arrangements. The average luminance can fulfill the requirements in Chinese road lighting Standard CJJ45-2006.

  16. INTEGRATED ON-BOARD COMPUTING SYSTEMS: PRESENT SITUATION REVIEW AND DEVELOPMENT PROSPECTS ANALYSIS IN THE AVIATION INSTRUMENT-MAKING INDUSTRY

    Directory of Open Access Journals (Sweden)

    P. P. Paramonov

    2013-03-01

    Full Text Available The article deals with present situation review and analysis of development prospects for integrated on-board computing systems, used in the aviation instrument-making industry. The main attention is paid to the projects carried out in the framework of an integrated modular avionics. Hierarchical levels of module design, crates (onboard systems and aviation complexes are considered in detail. Examples of the existing products of our country and from abroad and their brief technical characteristics are given and voluminous bibliography on the subject matter as well.

  17. Synthesis of control algorithms on-board information and control systems of aircraft at the minimum criterion of accesses to local memory

    Directory of Open Access Journals (Sweden)

    2015-01-01

    Full Text Available The technique of formation of the structure of the local memory on-Board information and control systems. Formalized the problem of choosing a set of programs to implement many of the algorithms and optimizing the structure of the local memory that belong to the class of problems of discrete programming with pseudoboolean variables. Based on the application of graph theory algorithms improve the efficient use of cache memory on-Board information and control systems.

  18. THE WHITE SANDS MISSILE RANGE PULSED REACTOR FACILITY, MAY 1963

    Energy Technology Data Exchange (ETDEWEB)

    Long, Robert L.; Boor, R.A.; Cole, W.M.; Elder, G.E.

    1963-05-15

    A brief statement of the mission of the White Sands Missile Range Nuclear Effects Laboratory is given. The new Nuclear Effects Laboratory Facility is described. This facility consists of two buildings-a laboratory and a reactor building. The White Sands Missile Range bare critical assembly, designated as the MoLLY-G, is described. The MoLLY-G, an unreflected, unmoderated right circular cylinder of uranium-molybdenum alloy designed for pulsed operation, will have a maximum burst capability of approximately 2 x 10/sup 17/ fissions with a burst width of 50 microseconds. The reactor construction and operating procedures are described. As designed, the MoLLY-G will provide an intense source of pulsed neutron and gamma radiation for a great variety of experimental and test arrangements. (auth)

  19. Airborne VOC measurements on board the Zeppelin NT during the PEGASOS campaigns in 2012 deploying the improvement Fast-GC-MSD system

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, Julia Elisabeth

    2014-04-01

    Volatile organic compounds (VOCs) comprise a large number of different species, estimated to 10{sup 4}-10{sup 6}. They are emitted on the Earth's surface from a variety of biogenic and anthropogenic sources. VOCs are removed by multiple pathways from the atmosphere, by oxidation and finally by dry or wet deposition. Most primary emitted VOCs are non-polar and therefore have a low solubility in water. Oxidation facilitates efficient VOC removal by wet deposition. In the atmosphere the main photochemical VOC oxidation agent is the OH radical. As a consequence the polarity of the VOCs is increased and they can be removed faster. The oxidation of VOCs proceeds in several steps until the VOCs are deposited or are eventually oxidized to carbon dioxide. A downside of the VOCs oxidation process lies in the production of significant amounts ozone if nitrogen oxide is present which is a serious health hazard. Most of the VOC oxidation takes place in lower part of the atmosphere between the altitudes of 100 to 1000 m, which is only sparsely analyzed. Therefore, fast VOCs measurements by GC-MSD on board the Zeppelin NT offered new important insights in the distribution of VOCs. The measurements were performed within the PEAGSOS campaigns in the Netherlands and in Italy in 2012. For the implementation of the GC-MSD system (HCG) on board the Zeppelin it was reconstructed to enhance its performance and to meet aviation requirements. The system was optimized to measure VOCs ranging from C4 to C10 as well as oxygenated VOCs (OVOCs) with a detection limit below 10 ppt. The analyzed VOCs for both parts of the campaigns showed low mean concentration below 5 ppb for all VOCs. Especially, the mixing ratios of the primary emitted VOCs were very low with mean values lower than 200 ppt. Higher concentrations could be observed for the OVOCs with mean concentrations up to 5 ppb. The most abundant OVOCs apart from formaldehyde were methanol, ethanol, acetone and acetaldehyde.

  20. On-Board Computing for Structural Health Monitoring with Smart Wireless Sensors by Modal Identification Using Hilbert-Huang Transform

    Directory of Open Access Journals (Sweden)

    Ning Wu

    2013-01-01

    Full Text Available Smart wireless sensors have been recognized as a promising technology to overcome many inherent difficulties and limitations associated with traditional wired structural health monitoring (SHM systems. Despite the advances in smart sensor technologies, on-board computing capability of smart sensors has been considered as one of the most difficult challenges in the application of the smart sensors in SHM. Taking the advantage of recent developments in microprocessor which provides powerful on-board computing functionality for smart sensors, this paper presents a new decentralized data processing approach for modal identification using the Hilbert-Huang transform (HHT algorithm, which is based on signal decomposition technique. It is shown that this method is suitable for implementation in the intrinsically distributed computing environment found in wireless smart sensor networks (WSSNs. The HHT-based decentralized data processing is, then, programmed and implemented on the Crossbow IRIS mote sensor platform. The effectiveness of the proposed techniques is demonstrated through a set of numerical studies and experimental validations on an in-house cable-stayed bridge model in terms of the accuracy of identified dynamic properties.

  1. Equivalent dose measurements on board an Armenian Airline flight and Concorde (correction of Concord) (9-17 km).

    Science.gov (United States)

    Akopova, A B; Melkonyan, A A; Tatikyan, S Sh; Capdevielle, J-N

    2002-12-01

    The results of investigations of the neutron component (E=1-10 MeV) of cosmic radiation on board the "Armenian Airlines" aircrafts using nuclear photoemulsion are presented. The emulsions were exposed on the flights from Yerevan to Moscow, St.-Petersburg, Beirut, Athens, Frankfurt, Amsterdam, Paris and Sofia, and on Concord supersonic flights from Paris to New York. The dependence of the neutron fluxes, and on absorbed and equivalent doses on the flight parameters were investigated. On the flights of the supersonic Concord, with an altitude of 17 km, the neutron fluxes were essentially higher in comparison to those measured on Armenian airliners. It is interesting to note, that the neutron flux and equivalent dose rate decrease with altitude up to 470 km in space, for example, on board the STS-57. The shape of the differential energy spectrum for fast neutrons is the same on all Armenian airlines flights, but significantly different at 17 km altitude, where the flux in the energy region above 3 MeV is increasing. c2002 Elsevier Science Ltd. All rights reserved.

  2. Assessment of the possible contribution of space ties on-board GNSS satellites to the terrestrial reference frame

    Science.gov (United States)

    Bruni, Sara; Rebischung, Paul; Zerbini, Susanna; Altamimi, Zuheir; Errico, Maddalena; Santi, Efisio

    2017-10-01

    The realization of the international terrestrial reference frame (ITRF) is currently based on the data provided by four space geodetic techniques. The accuracy of the different technique-dependent materializations of the frame physical parameters (origin and scale) varies according to the nature of the relevant observables and to the impact of technique-specific errors. A reliable computation of the ITRF requires combining the different inputs, so that the strengths of each technique can compensate for the weaknesses of the others. This combination, however, can only be performed providing some additional information which allows tying together the independent technique networks. At present, the links used for that purpose are topometric surveys (local/terrestrial ties) available at ITRF sites hosting instruments of different techniques. In principle, a possible alternative could be offered by spacecrafts accommodating the positioning payloads of multiple geodetic techniques realizing their co-location in orbit (space ties). In this paper, the GNSS-SLR space ties on-board GPS and GLONASS satellites are thoroughly examined in the framework of global reference frame computations. The investigation focuses on the quality of the realized physical frame parameters. According to the achieved results, the space ties on-board GNSS satellites cannot, at present, substitute terrestrial ties in the computation of the ITRF. The study is completed by a series of synthetic simulations investigating the impact that substantial improvements in the volume and quality of SLR observations to GNSS satellites would have on the precision of the GNSS frame parameters.

  3. Next Processor Module: A Hardware Accelerator of UT699 LEON3-FT System for On-Board Computer Software Simulation

    Science.gov (United States)

    Langlois, Serge; Fouquet, Olivier; Gouy, Yann; Riant, David

    2014-08-01

    On-Board Computers (OBC) are more and more using integrated systems on-chip (SOC) that embed processors running from 50MHz up to several hundreds of MHz, and around which are plugged some dedicated communication controllers together with other Input/Output channels.For ground testing and On-Board SoftWare (OBSW) validation purpose, a representative simulation of these systems, faster than real-time and with cycle-true timing of execution, is not achieved with current purely software simulators.Since a few years some hybrid solutions where put in place ([1], [2]), including hardware in the loop so as to add accuracy and performance in the computer software simulation.This paper presents the results of the works engaged by Thales Alenia Space (TAS-F) at the end of 2010, that led to a validated HW simulator of the UT699 by mid- 2012 and that is now qualified and fully used in operational contexts.

  4. Fuel consumption and associated emissions from seagoing ships at berth derived from an on-board survey

    Science.gov (United States)

    Hulskotte, J. H. J.; Denier van der Gon, H. A. C.

    2010-03-01

    A methodology is presented to estimate the emissions of ships at berth based on their actual fuel consumption and the fuel quality. Accurate estimates of emissions from ships at berth demand reliable knowledge of the fuel consumption while at berth and associated fuel characteristics. However, assured information about energy use and fuel consumption of seagoing ships at berth is scarce. Proper estimation of ship emissions at berth is crucial for understanding the impact of shipping emissions on air quality and health in harbour cities as well as for a proper evaluation of the impact of abatement measures such as shore-side electricity and/or restrictions of sulphur content for shipping fuels to be used in ports. Therefore, a survey of energy consumption and fuel use on board of 89 seagoing ships was made in close cooperation with the Port of Rotterdam. Rotterdam is the major port of Europe ensuring that the results will have relevance for the larger European domain. On board of the ships at berth, a questionnaire was filled in by the chief engineer of that particular ship, assisted by two former mechanical shipping engineers employed at our organization. Survey results as well as the emission estimations are compared to the (scarce) information that is available and expert judgements in recent studies. The compiled survey data underlie the current Dutch emission estimation methodology for emissions of ships at berth.

  5. Agile deployment and code coverage testing metrics of the boot software on-board Solar Orbiter's Energetic Particle Detector

    Science.gov (United States)

    Parra, Pablo; da Silva, Antonio; Polo, Óscar R.; Sánchez, Sebastián

    2018-02-01

    In this day and age, successful embedded critical software needs agile and continuous development and testing procedures. This paper presents the overall testing and code coverage metrics obtained during the unit testing procedure carried out to verify the correctness of the boot software that will run in the Instrument Control Unit (ICU) of the Energetic Particle Detector (EPD) on-board Solar Orbiter. The ICU boot software is a critical part of the project so its verification should be addressed at an early development stage, so any test case missed in this process may affect the quality of the overall on-board software. According to the European Cooperation for Space Standardization ESA standards, testing this kind of critical software must cover 100% of the source code statement and decision paths. This leads to the complete testing of fault tolerance and recovery mechanisms that have to resolve every possible memory corruption or communication error brought about by the space environment. The introduced procedure enables fault injection from the beginning of the development process and enables to fulfill the exigent code coverage demands on the boot software.

  6. Adaptive approach for on-board impedance parameters and voltage estimation of lithium-ion batteries in electric vehicles

    Science.gov (United States)

    Farmann, Alexander; Waag, Wladislaw; Sauer, Dirk Uwe

    2015-12-01

    Robust algorithms using reduced order equivalent circuit model (ECM) for an accurate and reliable estimation of battery states in various applications become more popular. In this study, a novel adaptive, self-learning heuristic algorithm for on-board impedance parameters and voltage estimation of lithium-ion batteries (LIBs) in electric vehicles is introduced. The presented approach is verified using LIBs with different composition of chemistries (NMC/C, NMC/LTO, LFP/C) at different aging states. An impedance-based reduced order ECM incorporating ohmic resistance and a combination of a constant phase element and a resistance (so-called ZARC-element) is employed. Existing algorithms in vehicles are much more limited in the complexity of the ECMs. The algorithm is validated using seven day real vehicle data with high temperature variation including very low temperatures (from -20 °C to +30 °C) at different Depth-of-Discharges (DoDs). Two possibilities to approximate both ZARC-elements with finite number of RC-elements on-board are shown and the results of the voltage estimation are compared. Moreover, the current dependence of the charge-transfer resistance is considered by employing Butler-Volmer equation. Achieved results indicate that both models yield almost the same grade of accuracy.

  7. Solar-Blind Diamond Detectors for Lyra, the Solar VUV Radiometer on Board Proba II

    Science.gov (United States)

    Benmoussa, A.; Hochedez, J.-F.; Schmutz, W. K.; Schühle, U.; Nesládek, M.; Stockman, Y.; Kroth, U.; Richter, M.; Theissen, A.; Remes, Z.; Haenen, K.; Mortet, V.; Koller, S.; Halain, J. P.; Petersen, R.; Dominique, M.; D'Olieslaeger, M.

    2003-12-01

    Fabrication, packaging and experimental results on the calibration of metal-semiconductor-metal (MSM) photodetectors made on diamond are reported. LYRA (Lyman-α RAdiometer onboard PROBA-2) will use diamond detectors for the first time in space for a solar physics instrument. A set of measurement campaigns was designed to obtain the XUV-to-VIS responsivity of the devices and other characterizations. The measurements of responsivity in EUV and VUV spectral ranges (40 240 nm) have been carried out by the Physkalisch-Technische Bundesanstalt (PTB) in Germany at the electron storage ring BESSY II. The longer wavelength range from 210 to 1127 nm was measured with monochromatic light by using a Xe-lamp at IMO-IMOMEC. The diamond detectors exhibit a photoresponse which lie in the 35 65 mA/W range at 200 nm (corresponding to an external quantum efficiency of 20 40%) and indicate a visible rejection ratio (200 500 nm) higher than four orders of magnitude.

  8. WE-AB-303-09: Rapid Projection Computations for On-Board Digital Tomosynthesis in Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Iliopoulos, AS; Sun, X [Duke University, Durham, NC (United States); Pitsianis, N [Aristotle University of Thessaloniki (Greece); Duke University, Durham, NC (United States); Yin, FF; Ren, L [Duke University Medical Center, Durham, NC (United States)

    2015-06-15

    Purpose: To facilitate fast and accurate iterative volumetric image reconstruction from limited-angle on-board projections. Methods: Intrafraction motion hinders the clinical applicability of modern radiotherapy techniques, such as lung stereotactic body radiation therapy (SBRT). The LIVE system may impact clinical practice by recovering volumetric information via Digital Tomosynthesis (DTS), thus entailing low time and radiation dose for image acquisition during treatment. The DTS is estimated as a deformation of prior CT via iterative registration with on-board images; this shifts the challenge to the computational domain, owing largely to repeated projection computations across iterations. We address this issue by composing efficient digital projection operators from their constituent parts. This allows us to separate the static (projection geometry) and dynamic (volume/image data) parts of projection operations by means of pre-computations, enabling fast on-board processing, while also relaxing constraints on underlying numerical models (e.g. regridding interpolation kernels). Further decoupling the projectors into simpler ones ensures the incurred memory overhead remains low, within the capacity of a single GPU. These operators depend only on the treatment plan and may be reused across iterations and patients. The dynamic processing load is kept to a minimum and maps well to the GPU computational model. Results: We have integrated efficient, pre-computable modules for volumetric ray-casting and FDK-based back-projection with the LIVE processing pipeline. Our results show a 60x acceleration of the DTS computations, compared to the previous version, using a single GPU; presently, reconstruction is attained within a couple of minutes. The present implementation allows for significant flexibility in terms of the numerical and operational projection model; we are investigating the benefit of further optimizations and accurate digital projection sub

  9. Wide-Field Gamma-Spectrometer BDRG: GRB Monitor On-Board the Lomonosov Mission

    Science.gov (United States)

    Svertilov, S. I.; Panasyuk, M. I.; Bogomolov, V. V.; Amelushkin, A. M.; Barinova, V. O.; Galkin, V. I.; Iyudin, A. F.; Kuznetsova, E. A.; Prokhorov, A. V.; Petrov, V. L.; Rozhkov, G. V.; Yashin, I. V.; Gorbovskoy, E. S.; Lipunov, V. M.; Park, I. H.; Jeong, S.; Kim, M. B.

    2018-02-01

    The study of GRB prompt emissions (PE) is one of the main goals of the Lomonosov space mission. The payloads of the GRB monitor (BDRG) with the wide-field optical cameras (SHOK) and the ultra-fast flash observatory (UFFO) onboard the Lomonosov satellite are intended for the observation of GRBs, and in particular, their prompt emissions. The BDRG gamma-ray spectrometer is designed to obtain the temporal and spectral information of GRBs in the energy range of 10-3000 keV as well as to provide GRB triggers on several time scales (10 ms, 1 s and 20 s) for ground and space telescopes, including the UFFO and SHOK. The BDRG instrument consists of three identical detector boxes with axes shifted by 90° from each other. This configuration allows us to localize a GRB source in the sky with an accuracy of ˜ 2°. Each BDRG box contains a phoswich NaI(Tl)/CsI(Tl) scintillator detector. A thick CsI(Tl) crystal in size of \\varnothing 130 × 17 mm is placed underneath the NaI(Tl) as an active shield in the soft energy range and as the main detector in the hard energy range. The ratio of the CsI(Tl) to NaI(Tl) event rates at varying energies can be employed as an independent metric to distinguish legitimate GRB signals from false positives originating from electrons in near-Earth vicinities. The data from three detectors are collected in a BA BDRG information unit, which generates a GRB trigger and a set of data frames in output format. The scientific data output is ˜ 500 Mb per day, including ˜ 180 Mb of continuous data for events with durations in excess of 100 ms for 16 channels in each detector, detailed energy spectra, and sets of frames with ˜ 5 Mb of detailed information for each burst-like event. A number of pre-flight tests including those for the trigger algorithm and calibration were carried out to confirm the reliability of the BDRG for operation in space.

  10. An Improved PID Algorithm Based on Insulin-on-Board Estimate for Blood Glucose Control with Type 1 Diabetes

    Science.gov (United States)

    Hu, Ruiqiang; Li, Chengwei

    2015-01-01

    Automated closed-loop insulin infusion therapy has been studied for many years. In closed-loop system, the control algorithm is the key technique of precise insulin infusion. The control algorithm needs to be designed and validated. In this paper, an improved PID algorithm based on insulin-on-board estimate is proposed and computer simulations are done using a combinational mathematical model of the dynamics of blood glucose-insulin regulation in the blood system. The simulation results demonstrate that the improved PID algorithm can perform well in different carbohydrate ingestion and different insulin sensitivity situations. Compared with the traditional PID algorithm, the control performance is improved obviously and hypoglycemia can be avoided. To verify the effectiveness of the proposed control algorithm, in silico testing is done using the UVa/Padova virtual patient software. PMID:26550021

  11. Technology Readiness Level (TRL) Advancement of the MSPI On-Board Processing Platform for the ACE Decadal Survey Mission

    Science.gov (United States)

    Pingree, Paula J.; Werne, Thomas A.; Bekker, Dmitriy L.; Wilson, Thor O.

    2011-01-01

    The Xilinx Virtex-5QV is a new Single-event Immune Reconfigurable FPGA (SIRF) device that is targeted as the spaceborne processor for the NASA Decadal Survey Aerosol-Cloud-Ecosystem (ACE) mission's Multiangle SpectroPolarimetric Imager (MSPI) instrument, currently under development at JPL. A key technology needed for MSPI is on-board processing (OBP) to calculate polarimetry data as imaged by each of the 9 cameras forming the instrument. With funding from NASA's ESTO1 AIST2 Program, JPL is demonstrating how signal data at 95 Mbytes/sec over 16 channels for each of the 9 multi-angle cameras can be reduced to 0.45 Mbytes/sec, thereby substantially reducing the image data volume for spacecraft downlink without loss of science information. This is done via a least-squares fitting algorithm implemented on the Virtex-5 FPGA operating in real-time on the raw video data stream.

  12. An Improved PID Algorithm Based on Insulin-on-Board Estimate for Blood Glucose Control with Type 1 Diabetes

    Directory of Open Access Journals (Sweden)

    Ruiqiang Hu

    2015-01-01

    Full Text Available Automated closed-loop insulin infusion therapy has been studied for many years. In closed-loop system, the control algorithm is the key technique of precise insulin infusion. The control algorithm needs to be designed and validated. In this paper, an improved PID algorithm based on insulin-on-board estimate is proposed and computer simulations are done using a combinational mathematical model of the dynamics of blood glucose-insulin regulation in the blood system. The simulation results demonstrate that the improved PID algorithm can perform well in different carbohydrate ingestion and different insulin sensitivity situations. Compared with the traditional PID algorithm, the control performance is improved obviously and hypoglycemia can be avoided. To verify the effectiveness of the proposed control algorithm, in silico testing is done using the UVa/Padova virtual patient software.

  13. GPS and Galileo Developments on Board the International Space Station With the Space Communications and Navigation (SCaN) Testbed

    Science.gov (United States)

    Pozzobon, Oscar; Fantinato, Samuele; Dalla Chiara, Andrea; Gamba, Giovanni; Crisci, Massimo; Giordana, Pietro; Enderle, Werner; Chelmins, David; Sands, Obed S.; Clapper, Carolyn J.; hide

    2016-01-01

    The Space Communications and Navigation (SCaN) is a facility developed by NASA and hosted on board the International Space Station (ISS) on an external truss since 2013.It has the objective of testing navigation and communication experimentations with a Software Defined Radio (SDR) approach, which permits software updates for testing new experimentations.NASA has developed the Space Telecommunications Radio System (STRS) architecture standard for SDRs used in space and ground-based platforms to provide commonality among radio developments to provide enhanced capability. The hardware is equipped with both L band front-end radios and the NASA space network communicates with it using S-band, Ku-band and Ka-band links.In May 2016 Qascom started GARISS (GPS and Galileo Receiver for the ISS), an activity of experimentation in collaboration with ESA and NASA that has the objective to develop and validate the acquisition and processing of combined GPS and Galileo signals on board the ISS SCaN testbed. This paper has the objective to present the mission, and provide preliminary details about the challenges in the design, development and verification of the waveform that will be installed on equipment with limited resources. GARISS is also the first attempt to develop a waveform for the ISS as part of an international collaboration between US and Europe. Although the final mission objective is to target dual frequency processing, initial operations will foresee a single frequency processing. Initial results and trade-off between the two options, as well as the final decision will be presented and discussed. The limited resources on board the SCaN with respect to the challenging requirements to acquire and track contemporaneously two satellite navigation systems, with different modulations and data structure, led to the need to assess the possibility of aiding from ground through the S-band. This option would allow assistance to the space receiver in order to provide

  14. Calibration of the Large Area X-Ray Proportional Counter (LAXPC) Instrument on board AstroSat

    Science.gov (United States)

    Antia, H. M.; Yadav, J. S.; Agrawal, P. C.; Verdhan Chauhan, Jai; Manchanda, R. K.; Chitnis, Varsha; Paul, Biswajit; Dedhia, Dhiraj; Shah, Parag; Gujar, V. M.; Katoch, Tilak; Kurhade, V. N.; Madhwani, Pankaj; Manojkumar, T. K.; Nikam, V. A.; Pandya, A. S.; Parmar, J. V.; Pawar, D. M.; Pahari, Mayukh; Misra, Ranjeev; Navalgund, K. H.; Pandiyan, R.; Sharma, K. S.; Subbarao, K.

    2017-07-01

    We present the calibration and background model for the Large Area X-ray Proportional Counter (LAXPC) detectors on board AstroSat. The LAXPC instrument has three nominally identical detectors to achieve a large collecting area. These detectors are independent of each other, and in the event analysis mode they record the arrival time and energy of each photon that is detected. The detectors have a time resolution of 10 μs and a dead-time of about 42 μs. This makes LAXPC ideal for timing studies. The energy resolution and peak channel-to-energy mapping were obtained from calibration on the ground using radioactive sources coupled with GEANT4 simulations of the detectors. The response matrix was further refined from observations of the Crab after launch. At around 20 keV the energy resolution of the detectors is 10%-15%, while the combined effective area of the three detectors is about 6000 cm2.

  15. On-board Data Processing to Lower Bandwidth Requirements on an Infrared Astronomy Satellite: Case of Herschel-PACS Camera

    Directory of Open Access Journals (Sweden)

    Christian Reimers

    2005-09-01

    Full Text Available This paper presents a new data compression concept, “on-board processing,” for infrared astronomy, where space observatories have limited processing resources. The proposed approach has been developed and tested for the PACS camera from the European Space Agency (ESA mission, Herschel. Using lossy and lossless compression, the presented method offers high compression ratio with a minimal loss of potentially useful scientific data. It also provides higher signal-to-noise ratio than that for standard compression techniques. Furthermore, the proposed approach presents low algorithmic complexity such that it is implementable on the resource-limited hardware. The various modules of the data compression concept are discussed in detail.

  16. Electric field computation analysis for the Electric Field Detector (EFD) on board the China Seismic-Electromagnetic Satellite (CSES)

    Science.gov (United States)

    Diego, P.; Bertello, I.; Candidi, M.; Mura, A.; Coco, I.; Vannaroni, G.; Ubertini, P.; Badoni, D.

    2017-11-01

    The floating potential variability of the Electric Field Detector (EFD) probes, on board the Chinese Seismo-Electromagnetic Satellite (CSES), has been modeled, and the effects of several structural and environmental elements have been determined. The expected floating potentials of the probes are computed considering the ambient ionospheric plasma parameter variations. In addition, the ion collection variability, due to the different probe attitudes along the orbit, and its effect on each floating potential, are considered. Particular attention is given to the analysis of the shadow produced by the stubs, in order to determine the artificial electric field introduced by instrumental effects which has to be subtracted from the real measurements. The modulation of the altered electric field, due to the effect on shadowing of the ion drift, as measured by the ESA satellite Swarm A in a similar orbit, is also modeled. Such simulations are made in preparation of real EFD data analysis performed during the upcoming flight of CSES.

  17. The high energy multicharged particle exposure of the microbial ecology evaluation device on board the Apollo 16 spacecraft

    Science.gov (United States)

    Benton, E. V.; Henke, R. P.

    1973-01-01

    The high energy multicharged cosmic-ray-particle exposure of the Microbial Ecology Evaluation Device package on board the Apollo 16 spacecraft was monitored using cellulose nitrate, Lexan polycarbonate, nuclear emulsion, and silver chloride crystal nuclear-track detectors. The results of the analysis of these detectors include the measured particle fluences, the linear energy transfer spectra, and the integral atomic number spectrum of stopping particle density. The linear energy transfer spectrum is used to compute the fractional cell loss in human kidney (T1) cells caused by heavy particles. Because the Microbial Ecology Evaluation Device was better shielded, the high-energy multicharged particle exposure was less than that measured on the crew passive dosimeters.

  18. An Investigation of the Sub-Microsecond Features of Dynamic Crack Propagation in PMMA and the Rdx-Based Explosive PBX 9205

    Science.gov (United States)

    Washabaugh, P. D.; Hill, L. G.

    2007-12-01

    A dynamic crack propagating in a brittle material releases enough thermal energy to produce visible light. The dynamic fracture of even macroscopically amorphous materials becomes unsteady as the crack propagation velocity approaches the material wave-speeds. The heat generated at a crack-tip, especially as it jumps, may be a mechanism to initiate a self-sustaining reaction in an energetic material. Experiments were conducted in specimens to simulate an infinite plate for ˜10 μs. The initial specimens were 152 mm square by 6 mm thick acrylic sheets, and were fabricated to study non-steady near-wave-speed crack propagation. A variant of this specimen embedded a 25 mm×3 mm PBX 9205 pellet to explore the influence of dynamic Mode-I cracks in these materials. The crack was initiated by up to 0.24 g of Detasheet placed along a precursor 50 mm long notch, with a shield to contain the reaction products and prevent propagation along the fractured surfaces. The crack was studied by means of a streak camera and a Fourier-filter of the light reflecting off the newly minted surfaces. The sub-microsecond behavior of holes initiating, preceding and coalescing with the main crack were observed in the PMMA samples. The embedding and mechanical loading of explosives by this technique did not initiate a self-sustaining reaction in preliminary testing.

  19. The Camera of the MASCOT Asteroid Lander on Board Hayabusa 2

    Science.gov (United States)

    Jaumann, R.; Schmitz, N.; Koncz, A.; Michaelis, H.; Schroeder, S. E.; Mottola, S.; Trauthan, F.; Hoffmann, H.; Roatsch, T.; Jobs, D.; Kachlicki, J.; Pforte, B.; Terzer, R.; Tschentscher, M.; Weisse, S.; Mueller, U.; Perez-Prieto, L.; Broll, B.; Kruselburger, A.; Ho, T.-M.; Biele, J.; Ulamec, S.; Krause, C.; Grott, M.; Bibring, J.-P.; Watanabe, S.; Sugita, S.; Okada, T.; Yoshikawa, M.; Yabuta, H.

    2017-07-01

    The MASCOT Camera (MasCam) is part of the Mobile Asteroid Surface Scout (MASCOT) lander's science payload. MASCOT has been launched to asteroid (162173) Ryugu onboard JAXA's Hayabusa 2 asteroid sample return mission on Dec 3rd, 2014. It is scheduled to arrive at Ryugu in 2018, and return samples to Earth by 2020. MasCam was designed and built by DLR's Institute of Planetary Research, together with Airbus-DS Germany. The scientific goals of the MasCam investigation are to provide ground truth for the orbiter's remote sensing observations, provide context for measurements by the other lander instruments (radiometer, spectrometer and magnetometer), the orbiter sampling experiment, and characterize the geological context, compositional variations and physical properties of the surface (e.g. rock and regolith particle size distributions). During daytime, clear filter images will be acquired. During night, illumination of the dark surface is performed by an LED array, equipped with 4×36 monochromatic light-emitting diodes (LEDs) working in four spectral bands. Color imaging will allow the identification of spectrally distinct surface units. Continued imaging during the surface mission phase and the acquisition of image series at different sun angles over the course of an asteroid day will contribute to the physical characterization of the surface and also allow the investigation of time-dependent processes and to determine the photometric properties of the regolith. The MasCam observations, combined with the MASCOT hyperspectral microscope (MMEGA) and radiometer (MARA) thermal observations, will cover a wide range of observational scales and serve as a strong tie point between Hayabusa 2's remote-sensing scales (103-10^{-3} m) and sample scales (10^{-3}-10^{-6} m). The descent sequence and the close-up images will reveal the surface features over a broad range of scales, allowing an assessment of the surface's diversity and close the gap between the orbital observations

  20. DSPACE hardware architecture for on-board real-time image/video processing in European space missions

    Science.gov (United States)

    Saponara, Sergio; Donati, Massimiliano; Fanucci, Luca; Odendahl, Maximilian; Leupers, Reiner; Errico, Walter

    2013-02-01

    The on-board data processing is a vital task for any satellite and spacecraft due to the importance of elaborate the sensing data before sending them to the Earth, in order to exploit effectively the bandwidth to the ground station. In the last years the amount of sensing data collected by scientific and commercial space missions has increased significantly, while the available downlink bandwidth is comparatively stable. The increasing demand of on-board real-time processing capabilities represents one of the critical issues in forthcoming European missions. Faster and faster signal and image processing algorithms are required to accomplish planetary observation, surveillance, Synthetic Aperture Radar imaging and telecommunications. The only available space-qualified Digital Signal Processor (DSP) free of International Traffic in Arms Regulations (ITAR) restrictions faces inadequate performance, thus the development of a next generation European DSP is well known to the space community. The DSPACE space-qualified DSP architecture fills the gap between the computational requirements and the available devices. It leverages a pipelined and massively parallel core based on the Very Long Instruction Word (VLIW) paradigm, with 64 registers and 8 operational units, along with cache memories, memory controllers and SpaceWire interfaces. Both the synthesizable VHDL and the software development tools are generated from the LISA high-level model. A Xilinx-XC7K325T FPGA is chosen to realize a compact PCI demonstrator board. Finally first synthesis results on CMOS standard cell technology (ASIC 180 nm) show an area of around 380 kgates and a peak performance of 1000 MIPS and 750 MFLOPS at 125MHz.

  1. A Statistical Method for Reducing Sidelobe Clutter for the Ku-Band Precipitation Radar on Board the GPM Core Observatory

    Science.gov (United States)

    Kubota, Takuji; Iguchi, Toshio; Kojima, Masahiro; Liao, Liang; Masaki, Takeshi; Hanado, Hiroshi; Meneghini, Robert; Oki, Riko

    2016-01-01

    A statistical method to reduce the sidelobe clutter of the Ku-band precipitation radar (KuPR) of the Dual-Frequency Precipitation Radar (DPR) on board the Global Precipitation Measurement (GPM) Core Observatory is described and evaluated using DPR observations. The KuPR sidelobe clutter was much more severe than that of the Precipitation Radar on board the Tropical Rainfall Measuring Mission (TRMM), and it has caused the misidentification of precipitation. The statistical method to reduce sidelobe clutter was constructed by subtracting the estimated sidelobe power, based upon a multiple regression model with explanatory variables of the normalized radar cross section (NRCS) of surface, from the received power of the echo. The saturation of the NRCS at near-nadir angles, resulting from strong surface scattering, was considered in the calculation of the regression coefficients.The method was implemented in the KuPR algorithm and applied to KuPR-observed data. It was found that the received power from sidelobe clutter over the ocean was largely reduced by using the developed method, although some of the received power from the sidelobe clutter still remained. From the statistical results of the evaluations, it was shown that the number of KuPR precipitation events in the clutter region, after the method was applied, was comparable to that in the clutter-free region. This confirms the reasonable performance of the method in removing sidelobe clutter. For further improving the effectiveness of the method, it is necessary to improve the consideration of the NRCS saturation, which will be explored in future work.

  2. The Psychological General Well-Being Index (PGWBI) for assessing stress of seafarers on board merchant ships.

    Science.gov (United States)

    Carotenuto, Anna; Fasanaro, Angiola M; Molino, Ivana; Sibilio, Fabio; Saturnino, Andrea; Traini, Enea; Amenta, Francesco

    2013-01-01

    In their working activity, seafarers are exposed to high levels of stress that should be accuratelyinvestigated, measured, followed up and, if possible, countered. This is also required by regulations recently entered into force such as the Maritime Labour Convention 2006, recommending to consider special physiological or psychological problems created by the shipboard environment. The choice of the tools for this evaluation is challenging, and a common basic standard usable in a large scale should be identified. The aim of this study was to evaluate: 1) the suitability of the Psychological General Well-Being Index (PGWBI) questionnaire conducted on board for assessing stress in the sailing seafarers, 2) The presenceof stress in seafarers of different categories (deck officers, engine officers, deck crew, engine crew, chiefstewards/catering staff) monitored by the PGWBI. 162 male seafarers on board of 7 tankers belonging to the same shipping companywere evaluated through the PGWB questionnaire. Analysis of variance (ANOVA) was used to analyse thedifferences in the scores of the questionnaire. Engine officers exhibited significantly higher anxiety levels than the deck or engine crew, andshowed lower satisfaction than the deck crew. Deck and engine officers revealed higher self-control levelsthan the engine crew. Chief stewards/catering staff showed lower vitality levels than the deck crew. Deck or engine officers should achieve a greater self-control than the crew and this is documentedby the present study. Our findings support the view that management responsibility is more often associated with higher levels of stress. In our opinion, the PGWB questionnaire is a reasonable compromise forobtaining a global evaluation of psychological conditions, including stress of seafarers. It should be therefore considered as a large scale tool for assessing the well-being and eventual stress levels of sailing seafarers.

  3. Lightweight UAV with on-board photogrammetry and single-frequency GPS positioning for metrology applications

    Science.gov (United States)

    Daakir, M.; Pierrot-Deseilligny, M.; Bosser, P.; Pichard, F.; Thom, C.; Rabot, Y.; Martin, O.

    2017-05-01

    This article presents a coupled system consisting of a single-frequency GPS receiver and a light photogrammetric quality camera embedded in an Unmanned Aerial Vehicle (UAV). The aim is to produce high quality data that can be used in metrology applications. The issue of Integrated Sensor Orientation (ISO) of camera poses using only GPS measurements is presented and discussed. The accuracy reached by our system based on sensors developed at the French Mapping Agency (IGN) Opto-Electronics, Instrumentation and Metrology Laboratory (LOEMI) is qualified. These sensors are specially designed for close-range aerial image acquisition with a UAV. Lever-arm calibration and time synchronization are explained and performed to reach maximum accuracy. All processing steps are detailed from data acquisition to quality control of final products. We show that an accuracy of a few centimeters can be reached with this system which uses low-cost UAV and GPS module coupled with the IGN-LOEMI home-made camera.

  4. Development of the Kiel sensors for the EPD instrument on-board Solar Orbiter

    Science.gov (United States)

    Martin, Cesar; Wimmer-Schweingruber, Robert F.; Kulkarni, Shrinivasrao R.; Tammen, Jan; Terasa, Christoph; Yu, Jia; Boden, Sebastian; Steinhagen, Jan; Panitzsch, Lauri; Ravanbakhsh, Ali; Boettcher, Stephan; Hamann, Christian; Seimetz, Lars; Rodriguez-Pacheco, Javier

    2015-04-01

    Solar Orbiter is ESA's next solar and heliospheric mission, planned for launch in January 2017 and approaching the Sun as close as 0.28 AU. One of the Solar Orbiter's scientific questions is "How do the solar eruptions produce energetic particle radiation that fills the heliosphere?". The Energetic Particle Detector (EPD) will provide key measurements for this and the other Solar Orbiter science objectives. The EPD suite consists of four sensors measuring electrons, protons, and ions from helium to iron, and operating at partly overlapping energy ranges from 2 keV/n up to 200 MeV/n. The EPD sensors are: SupraThermal Electrons and Protons(STEP), Suprathermal Ion Spectrograph (SIS), Electron Proton Telescope (EPT) and High Energy Telescope (HET). Besides, the EPD sensors share the Instrument Control Unit (ICU). The University of Kiel in Germany is responsible for developing the EPT-HET, STEP and SIS sensors. Here we present the development status of the EPT-HET and STEP sensors focusing on the activities planned for the current phase C. Those activities include results of the integration and EMC tests on the EPT-HET and STEP Engineering Model (EM) and the assembly of the Proto Qualification Model (PQM).

  5. Design and scientific performance of the soft x-ray imager on board EXIST

    Science.gov (United States)

    Natalucci, Lorenzo; Tagliaferri, Gianpiero; Bazzano, Angela; Caraveo, Patrizia; Della Ceca, Roberto; Grindlay, Jonathan E.; Pareschi, Giovanni; Ramsey, Brian D.; Ubertini, Pietro; Uslenghi, Michela C. A.

    2010-07-01

    The EXIST mission has been recently re-designed prior to being proposed to the ASTRO2010 Decadal Survey. One of the most recent improvements has been the addition of a third instrument consisting of a powerful Soft X-ray Imager (SXI) that will study in detail and help characterizing the high energy sources detected by the High Energy Telescope (HET). The EXIST concept fully exploits the heritage of Swift in the fast follow-up of transients and in particular GRBs, with 10 to 20 times more sensitivity in the high energy band (from 0.2 to 600 keV) and exceptional performance in the near-IR/optical provided by the Infrared Telescope (IRT). SXI has an important role in extending by more than one decade in energy, down to the soft X-rays the coverage of HET. Such combination will be fully exploited when performing pointed observations. Within the EXIST follow-up program, foreseen during the second part of the mission, SXI and HET will be able to collect high quality spectra for thousands of sources covering the energy range 0.1- hundreds keV. Furthermore, while working in survey mode SXI will cover about half the sky in 2 years and will be able to improve the location accuracy of many faint HET sources (reducing the positional uncertainty from 20 arcsec to ~ 1-2 arcsec). In this paper we will address the performance and the main scientific contributions expected from SXI.

  6. Comparison of compact reformer configurations for on-board fuel processing

    Energy Technology Data Exchange (ETDEWEB)

    Karakaya, Mustafa; Avci, Ahmet K. [Department of Chemical Engineering, Bogazici University, Bebek 34342, Istanbul (Turkey)

    2010-03-15

    Two compact reformer configurations in the context of production of hydrogen in a fuel processing system for use in a Proton Exchange Membrane Fuel Cell (PEMFC) based auxiliary power unit in the 2-3 kW range are compared using computer-based modeling techniques. Hydrogen is produced via catalytic steam reforming of n-heptane, the surrogate for petroleum naphtha. Heat required for this endothermic reaction is supplied via catalytic combustion of methane, the model compound for natural gas. The combination of steam reforming and catalytic combustion is modeled for a microchannel reactor configuration in which reactions and heat transfer take place in parallel, micro-sized flow paths with wall-coated catalysts and for a cascade reactor configuration in which reactions occur in a series of adiabatic packed-beds, heat exchange in interconnecting microchannel heat exchangers being used to maintain the desired temperature. Size and efficiency of the fuel processor consisting of the reformer, hydrogen clean-up units and heat exchange peripherals are estimated for either case of using a microchannel and a cascade configuration in the reforming step. The respective sizes of fuel processors with microchannel and cascade configurations are 1.53 x 10{sup -3} and 1.71 x 10{sup -3} m{sup 3}. The overall efficiency of the fuel processor, defined as the ratio of the lower heating value of the hydrogen produced to the lower heating value of the fuel consumed, is 68.2% with the microchannel reactor and 73.5% with the cascade reactor mainly due to 30% lower consumption of n-heptane in the latter. The cascade system also offers advanced temperature control over the reactions and ease of catalyst replacement. (author)

  7. CLUPI: CLose-UP Imager on.board the ExoMars Mission Rover

    Science.gov (United States)

    Josset, Jean-Luc

    The CLose-UP Imager (CLUPI) imaging experiment is designed to obtain high-resolution colour and stereo images of rocks from the ExoMars rover (Pasteur payload). The close-up imager is a robotic equivalent of one of the most useful instruments of the field geologist: the hand lens. Imaging of surfaces of rocks, soils and wind drift deposits is crucial for the understanding of the geological context of any site where the rover will be active on Mars. The purpose of the Close-up imager is to look an area of about 4 cm x 2.6 cm of the rocks at a focus distance of 10 cm. With a resolution of approx. 15 micrometer/pixel, many kinds of rock surface and internal structures can be visualized: crystals in igneous rocks, fracture mineralization, secondary minerals, details of the surface morphology, sediment components, sedimentary structures, soil particles. It is conceivable that even textures resulting from ancient biological activity can be seen, such as fine lamination due to microbial mats (stromatolites) and textures resulting from colonies of filamentous microbes. CLUPI is a powerful highly integrated miniaturized (¡208g) low-power robust imaging system with no mobile part, able to operate at very low temperature (-120° C). The opto-mechanical interfaces will be a smart assembly in titanium sustaining wide temperature range. The concept benefits from well-proven heritage: Proba, Rosetta, MarsExpress and Smart-1 missions. . . The close-up imager CLUPI on the ExoMars Rover will be described together with its capabilities to provide important information significantly contributing to the understanding of the geological environment and could identify outstanding potential biofabrics (stromatolites...) of past life on Mars.

  8. Thermal ion measurements on board Interball Auroral Probe by the Hyperboloid experiment

    Directory of Open Access Journals (Sweden)

    N. Dubouloz

    Full Text Available Hyperboloid is a multi-directional mass spectrometer measuring ion distribution functions in the auroral and polar magnetosphere of the Earth in the thermal and suprathermal energy range. The instrument encompasses two analyzers containing a total of 26 entrance windows, and viewing in two almost mutually perpendicular half-planes. The nominal angular resolution is defined by the field of view of individual windows ≈13° × 12.5°. Energy analysis is performed using spherical electrostatic analyzers providing differential measurements between 1 and 80 eV. An ion beam emitter (RON experiment and/or a potential bias applied to Hyperboloid entrance surface are used to counteract adverse effects of spacecraft potential and thus enable ion measurements down to very low energies. A magnetic analyzer focuses ions on one of four micro-channel plate (MCP detectors, depending on their mass/charge ratio. Normal modes of operation enable to measure H+, He+, O++, and O+ simultaneously. An automatic MCP gain control software is used to adapt the instrument to the great flux dynamics encountered between spacecraft perigee (700 km and apogee (20 000 km. Distribution functions in the main analyzer half-plane are obtained after a complete scan of windows and energies with temporal resolution between one and a few seconds. Three-dimensional (3D distributions are measured in one spacecraft spin period (120 s. The secondary analyzer has a much smaller geometrical factor, but offers partial access to the 3D dependence of the distributions with a few seconds temporal resolution. Preliminary results are presented. Simultaneous, local heating of both H+ and O+ ions resulting in conical distributions below 80 eV is observed up to 3 Earth's radii altitudes. The thermal ion signatures associated with large-scale nightside magnetospheric boundaries are investigated and a new ion outflow feature is

  9. Microsecond current output in PbNb(Zr,Sn,Ti)O3 ceramic under shock wave compression

    Science.gov (United States)

    Dongdong, Jiang; Jinmei, Du; Jia, Yang; Yan, Gu; Yujun, Feng; LaboratoryShock Wave; Detonation Physics Research, Institute Of Fluid Physics Team; Electronic Materials Research Laboratory, Xi'An Jiaotong University, Xi'An, 710049 Collaboration

    2011-06-01

    Technology of high power pulse has been the core of many scientific and engineering applications. Shock wave-driven ferroelectric power supply is smaller, lighter and at the same time more powerful than traditional technology. We reported the shock wave induced current output of PbNb(Zr,Sn,Ti)O3 ceramic. Chosen composition was Pb0.99Nb0.02[(Zr0.90Sn0.10)0.96Ti0.04]0.98O3 and near the ferroelectric and antiferroelectric phase boundary. Shock wave obtained via gas-gun projectile impact ranged from 0.24 to 2.50 GPa and depolarized ceramics in the normal mode, in which the shock propagation vector was perpendicular to the remanent polarization. Variation of electric field was by selecting a load resistor. Output currents under short-circuit and high-impedance conditions were obtained. Results suggest that PbNb(Zr,Sn,Ti)O3 is a promising material for a source of power supply and provide a basis for future pulse power design.

  10. Laser stimulation of the auditory system at 1.94 μm and microsecond pulse durations

    Science.gov (United States)

    Izzo, Agnella D.; Walsh, Joseph T., Jr.; Ralph, Heather; Webb, Jim; Wells, Jonathon; Bendett, Mark; Richter, Claus-Peter

    2008-02-01

    Light can artificially stimulate nerve activity in vivo. A significant advantage of optical neural stimulation is the potential for higher spatial selectivity when compared with electrical stimulation. An increased spatial selectivity of stimulation could improve significantly the function of neuroprosthetics, such as cochlear implants. Cochlear implants restore a sense of hearing and communication to deaf individuals by directly electrically stimulating the remaining neural cells in the cochlea. However, performance is limited by overlapping electric fields from neighboring electrodes. Here, we report on experiments with a new laser, offering a previously unavailable wavelength, 1.94μm, and pulse durations down to 5μs, to stimulate cochlear neurons. Compound action potentials (CAP) were evoked from the gerbil cochlea with pulse durations as short as 1μs. Data show that water absorption of light is a significant factor in optical stimulation, as evidenced by the required distance between the optical fiber and the neurons during stimulation. CAP threshold measurements indicate that there is an optimal range of pulse durations over which to deposit the laser energy, less than ~100μs. The implications of these data could direct further research and design of an optical cochlear implant.

  11. Achieve Location Privacy-Preserving Range Query in Vehicular Sensing.

    Science.gov (United States)

    Kong, Qinglei; Lu, Rongxing; Ma, Maode; Bao, Haiyong

    2017-08-08

    Modern vehicles are equipped with a plethora of on-board sensors and large on-board storage, which enables them to gather and store various local-relevant data. However, the wide application of vehicular sensing has its own challenges, among which location-privacy preservation and data query accuracy are two critical problems. In this paper, we propose a novel range query scheme, which helps the data requester to accurately retrieve the sensed data from the distributive on-board storage in vehicular ad hoc networks (VANETs) with location privacy preservation. The proposed scheme exploits structured scalars to denote the locations of data requesters and vehicles, and achieves the privacy-preserving location matching with the homomorphic Paillier cryptosystem technique. Detailed security analysis shows that the proposed range query scheme can successfully preserve the location privacy of the involved data requesters and vehicles, and protect the confidentiality of the sensed data. In addition, performance evaluations are conducted to show the efficiency of the proposed scheme, in terms of computation delay and communication overhead. Specifically, the computation delay and communication overhead are not dependent on the length of the scalar, and they are only proportional to the number of vehicles.

  12. Status On Multi-microsecond Prepulse Technique On Sphinx Machine Going From Nested To Single Wire Array For 800 ns Implosion Time Z-pinch

    Science.gov (United States)

    Maury, P.; Calamy, H.; Grunenwald, J.; Lassalle, F.; Zucchini, F.; Loyen, A.; Georges, A.; Morell, A.; Bedoch, J. P.

    2009-01-01

    The Sphinx machine[1] is a 6 MA, 1 μS driver based on the LTD technology, used for Z-pinch experiments. Important improvements of Sphinx radiation output were recently obtained using a multi-microsecond current prepulse[2]. Total power per unit of length is multiplied by a factor of 6 and FWHM divided by a factor of 2.5. Early breakdown of the wires during the prepulse phase dramatically changes the ablation phase leading to an improvement of axial homogeneity of both the implosion and the final radiating column. As a consequence, the cathode bubble observed on classical shots is definitively removed. The implosion is then centered and zippering effect is reduced, leading to simultaneous x-ray emission of the whole length. A great reproducibility is obtained. Nested arrays were used before to mitigate the Rayleigh-Taylor instabilities during the implosion phase. Further experiments with pre-pulse technique are described here were inner array was removed. The goal of these experiments was to see if long prepulse could give stable enough implosion with single array and at the same time increase the η parameter by reducing the mass of the load. Experimental results of single wire array loads of typical dimension 5 cm in height with implosion time between 700 and 900 ns and diameter varying between 80 and 140 mm are given. Parameters of the loads were varying in term of radius and number of wires. Comparisons with nested wire array loads are done and trends are proposed. Characteristics of both the implosion and the final radiating column are shown. 2D MHD numerical simulations of single wire array become easier as there is no interaction between outer and inner array anymore. A systematic study was done using injection mass model to benchmark simulation with experiments.

  13. CONTROL ENGINEERING ON BOARD

    Directory of Open Access Journals (Sweden)

    Serghei RADU

    2012-11-01

    Full Text Available Control engineering embraces instrumentation, alarm systems, control of machinery and plant previously known under the misnomer of automation. Control engineering can be applied not only to propelling and auxiliary machinery but also to electrical installations, refrigeration, cargo handling (especially in tankers and deck machinery, e.g. Windlass control. Opinion still vary on such matters as the relative merits of pneumatic versus electronic system and whether the control center should be in the engine room or adjacent to the navigating bridge. Arguments against the exclusion of the engineer officer from close contact with the machinery are countered by the fact that electronic systems are based on changes other than those of human response. Automated ships (UMS operate closer to prescribed standards and therefore operate with greater efficiency. The closer control of machinery operating conditions, e.g. cooling water temperatures and pressures, permits machinery to be run at its optimum design conditions, making for fuel economy and reduced maintenance. Automation can carry out some tasks far more effectively than men. In other areas it is less effective. For example, the monitoring of machinery operating conditions such as the temperatures and pressures can be carried out by a solid state alarm scanning system at the rate of 400 channels/sec., giving a degree of surveillance which would be impossible by human observation. Conversely, the detection of noisy bearing, a leaky gland or cracked pipe is scarcely possible by automatic means. The balance between the possible and the necessary would be achieved in this case by combining automatic monitoring of all the likely fault conditions, with routine machinery space inspection say twice a day.

  14. "Welcome on board"

    NARCIS (Netherlands)

    Holthuysen, Nancy T.E.; Vrijhof, Milou N.; Wijk, de René A.; Kremer, Stefanie

    2017-01-01

    The main objective of this study was to evaluate the effect of contexts on overall liking and just-about-right (JAR) ratings of airplane meals. A rice dish (meal type A) and a pasta dish (meal type B) were assessed. Per meal type, two variants were produced (variant 1 and 2). Two hundred

  15. Babee on board.

    Science.gov (United States)

    2017-07-05

    This app aims to make it easier for people to be aware when there is a pregnant person nearby who would like to be offered a seat on public transport. There are two versions of the app. The offer seat app is free and enables users to be notified when a pregnant person presses the button.

  16. Detection of Widespread Hydrated Materials on Vesta by the VIR Imaging Spectrometer on board the Dawn Mission

    Science.gov (United States)

    De Sanctis, M. C.; Combe, J.-Ph.; Ammannito, E.; Palomba, E.; Longobardo, A.; McCord, T. B.; Marchi, S.; Capaccioni, F.; Capria, M. T.; Mittlefehldt, D. W.; Pieters, C. M.; Sunshine, J.; Tosi, F.; Zambon, F.; Carraro, F.; Fonte, S.; Frigeri, A.; Magni, G.; Raymond, C. A.; Russell, C. T.; Turrini, D.

    2012-10-01

    Water plays a key role in the evolution of terrestrial planets, and notably in the occurrence of Earth's oceans. However, the mechanism by which water has been incorporated into these bodies—including Earth—is still extensively debated. Here we report the detection of widespread 2.8 μm OH absorption bands on the surface of the asteroid Vesta by the VIR imaging spectrometer on board Dawn. These observations are surprising as Vesta is fully differentiated with a basaltic surface. The 2.8 μm OH absorption is distributed across Vesta's surface and shows areas enriched and depleted in hydrated materials. The uneven distribution of hydrated mineral phases is unexpected and indicates ancient processes that differ from those believed to be responsible for OH on other airless bodies, like the Moon. The origin of Vestan OH provides new insight into the delivery of hydrous materials in the main belt and may offer new scenarios on the delivery of hydrous minerals in the inner solar system, suggesting processes that may have played a role in the formation of terrestrial planets.

  17. Harvesting Entropy for Random Number Generation for Internet of Things Constrained Devices Using On-Board Sensors

    Science.gov (United States)

    Pawlowski, Marcin Piotr; Jara, Antonio; Ogorzalek, Maciej

    2015-01-01

    Entropy in computer security is associated with the unpredictability of a source of randomness. The random source with high entropy tends to achieve a uniform distribution of random values. Random number generators are one of the most important building blocks of cryptosystems. In constrained devices of the Internet of Things ecosystem, high entropy random number generators are hard to achieve due to hardware limitations. For the purpose of the random number generation in constrained devices, this work proposes a solution based on the least-significant bits concatenation entropy harvesting method. As a potential source of entropy, on-board integrated sensors (i.e., temperature, humidity and two different light sensors) have been analyzed. Additionally, the costs (i.e., time and memory consumption) of the presented approach have been measured. The results obtained from the proposed method with statistical fine tuning achieved a Shannon entropy of around 7.9 bits per byte of data for temperature and humidity sensors. The results showed that sensor-based random number generators are a valuable source of entropy with very small RAM and Flash memory requirements for constrained devices of the Internet of Things. PMID:26506357

  18. DETECTION OF WIDESPREAD HYDRATED MATERIALS ON VESTA BY THE VIR IMAGING SPECTROMETER ON BOARD THE DAWN MISSION

    Energy Technology Data Exchange (ETDEWEB)

    De Sanctis, M. C.; Ammannito, E.; Palomba, E.; Longobardo, A.; Capaccioni, F.; Capria, M. T.; Tosi, F.; Zambon, F.; Carraro, F.; Fonte, S.; Frigeri, A.; Magni, G. [Istituto di Astrofisica e Planetologia Spaziali, INAF, Rome (Italy); Combe, J.-Ph.; McCord, T. B. [Bear Fight Institute, Winthrop, WA (United States); Marchi, S. [NASA Lunar Science Institute, Boulder, CO (United States); Mittlefehldt, D. W. [NASA Johnson Space Center, Houston, TX (United States); Pieters, C. M. [Department of Geological Sciences, Brown University, Providence, RI (United States); Sunshine, J. [Department of Astronomy, University of Maryland, Maryland (United States); Raymond, C. A. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA (United States); Russell, C. T., E-mail: mariacristina.desanctis@iaps.inaf.it [Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA (United States); and others

    2012-10-20

    Water plays a key role in the evolution of terrestrial planets, and notably in the occurrence of Earth's oceans. However, the mechanism by which water has been incorporated into these bodies-including Earth-is still extensively debated. Here we report the detection of widespread 2.8 {mu}m OH absorption bands on the surface of the asteroid Vesta by the VIR imaging spectrometer on board Dawn. These observations are surprising as Vesta is fully differentiated with a basaltic surface. The 2.8 {mu}m OH absorption is distributed across Vesta's surface and shows areas enriched and depleted in hydrated materials. The uneven distribution of hydrated mineral phases is unexpected and indicates ancient processes that differ from those believed to be responsible for OH on other airless bodies, like the Moon. The origin of Vestan OH provides new insight into the delivery of hydrous materials in the main belt and may offer new scenarios on the delivery of hydrous minerals in the inner solar system, suggesting processes that may have played a role in the formation of terrestrial planets.

  19. U-PHOS Project: Development of a Large Diameter Pulsating Heat Pipe Experiment on board REXUS 22

    Science.gov (United States)

    Nannipieri, P.; Anichini, M.; Barsocchi, L.; Becatti, G.; Buoni, L.; Celi, F.; Catarsi, A.; Di Giorgio, P.; Fattibene, P.; Ferrato, E.; Guardati, P.; Mancini, E.; Meoni, G.; Nesti, F.; Piacquadio, S.; Pratelli, E.; Quadrelli, L.; Viglione, A. S.; Zanaboni, F.; Mameli, M.; Baronti, F.; Fanucci, L.; Marcuccio, S.; Bartoli, C.; Di Marco, P.; Bianco, N.; Marengo, M.; Filippeschi, S.

    2017-01-01

    U-PHOS Project aims at analysing and characterising the behaviour of a large diameter Pulsating Heat Pipe (PHP) on board REXUS 22 sounding rocket. A PHP is a passive thermal control device where the heat is efficiently transported by means of the self-sustained oscillatory fluid motion driven by the phase change phenomena. Since, in milli-gravity conditions, buoyancy forces become less intense, the PHP diameter may be increased still maintaining the slug/plug typical flow pattern. Consequently, the PHP heat power capability may be increased too. U-PHOS aims at proving that a large diameter PHP effectively works in milli-g conditions by characterizing its thermal response during a sounding rocket flight. The actual PHP tube is made of aluminum (3 mm inner diameter, filled with FC-72), heated at the evaporator by a compact electrical resistance, cooled at the condenser by a Phase Change Material (PCM) embedded in a metallic foam. The tube wall temperatures are recorded by means of Fibre Bragg Grating (FBG) sensors; the local fluid pressure is acquired by means of a pressure transducer. The present work intends to report the actual status of the project, focusing in particular on the experiment improvements with respect to the previous campaign.

  20. Seabird bycatch in Portuguese mainland coastal fisheries: An assessment through on-board observations and fishermen interviews

    Directory of Open Access Journals (Sweden)

    Nuno Oliveira

    2015-01-01

    Full Text Available Competition with fisheries and incidental capture in fishing gear are the major current threats for seabirds at sea. Fishing is a traditional activity in Portugal and is mainly composed of a great number of small vessels. Given the lack of knowledge on effects of the Portuguese fishing fleet on seabird populations, bycatch was assessed in mainland coastal waters for 2010–2012. Interviews and on-board data were divided into 5 strata, according to fishing gear: Bottom trawling, Bottom longline, Purse seine, Beach seine, Polyvalent (≥12  m and Polyvalent (<12 m. Polyvalent included Setnets, Traps and Demersal longlines. Overall, 68 birds were recorded to be bycaught. The average catch per unit effort (CPUE was 0.05 birds per fishing event. Polyvalent (<12 m, Polyvalent (≥12  m and Purse seiners had the biggest seabird bycatch rates, with 0.5 (CPUE=0.1, 0.11 (CPUE=0.05 and 0.2 (CPUE=0.11 birds per trip, respectively. Within Polyvalent gear, Setnets captured the largest diversity of seabird species (CPUE=0.06, while Demersal longline had the highest CPUE (0.86. Northern gannet was the most common bycaught species. Although more observation effort is required, our results suggest that substantial numbers of Balearic shearwater might be bycaught annually, mainly in Purse seine and Setnets.

  1. Study on the possibility of adopting a complex method in Blattella germanica (L.) control on board ships.

    Science.gov (United States)

    Ulewicz, K; Wegner, Z; Kruminisłozowska, W

    1979-06-01

    Campaings to control the German cockroach, Blattela germanica, were conducted at 14-day intervals over a period of 5.5 months on two merchant vessels of similar size and type. On one ship only the chemical "Gertoks", carbamate insecticide containing 1% propoxur was applied, and on the second ship two preparations simultaneously, a chemical and a biological--"Biotrol 25 W" containing Bacillus thuringiensis. - In order to assess the success of the control, the extent of infestation in the accomodation was determined immediately before and 24 h after the spraying. - The susceptibility of the cockroaches caught on the ships, to the two preparations applied, was also determined. It was found that "Gertoks" was an efficient preparation, the biopreparation "Biotrol 25 W" being less efficient. - A certain increase in resistance of the cockroaches to both preparations, was noted. - The above observations indicate that a considerable drop in numbers of population of cockroaches can be achieved if the ship's crew carry out systematic thorough spraying of ships quarters infested by cockroaches, with Gertoks". They also confirm previous suggestions that complex method in B. germanica control on board ships is possible, using chemical and biological preparations containing Bac. thuringiensis spores simultaneously.

  2. A High-Density, High-Efficiency, Isolated On-Board Vehicle Battery Charger Utilizing Silicon Carbide Power Devices

    Energy Technology Data Exchange (ETDEWEB)

    Whitaker, B; Barkley, A; Cole, Z; Passmore, B; Martin, D; McNutt, TR; Lostetter, AB; Lee, JS; Shiozaki, K

    2014-05-01

    This paper presents an isolated on-board vehicular battery charger that utilizes silicon carbide (SiC) power devices to achieve high density and high efficiency for application in electric vehicles (EVs) and plug-in hybrid EVs (PHEVs). The proposed level 2 charger has a two-stage architecture where the first stage is a bridgeless boost ac-dc converter and the second stage is a phase-shifted full-bridge isolated dc-dc converter. The operation of both topologies is presented and the specific advantages gained through the use of SiC power devices are discussed. The design of power stage components, the packaging of the multichip power module, and the system-level packaging is presented with a primary focus on system density and a secondary focus on system efficiency. In this work, a hardware prototype is developed and a peak system efficiency of 95% is measured while operating both power stages with a switching frequency of 200 kHz. A maximum output power of 6.1 kW results in a volumetric power density of 5.0 kW/L and a gravimetric power density of 3.8 kW/kg when considering the volume and mass of the system including a case.

  3. Driver-Vehicle-Environment monitoring for on-board driver support systems: lessons learned from design and implementation.

    Science.gov (United States)

    Amditis, Angelos; Pagle, Katia; Joshi, Somya; Bekiaris, Evangelos

    2010-03-01

    This paper is presenting the efforts to implement in real time and for on-board applications a set of Driver-Vehicle-Environment (DVE) monitoring modules based on the theoretical work done in DVE modelling within the EC 6th FW co funded AIDE Integrated Project. First the need for such an implementation will be discussed. Then the basic DVE modelling principles will be introduced and analysed. Based on that and on the overview of the theoretical work performed around the DVE modelling, the real time DVE monitoring modules developed in this project will be presented and analysed. To do this the DVE parameters needed to allow the required functionalities will be discussed and analysed. Special attention will be given to the use cases and scenarios of use for the real time DVE modules. This allows the reader to understand the functionalities that these modules enable in tomorrow's vehicles that will integrate a large degree of automation supported by advanced integrated and adaptive human machine interfaces (HMIs). The paper will also present examples of the functional and technical tests and validation results for some of the DVE modules. The paper will conclude with a discussion around the lessons learned about the design and implementation of such systems. This will include also the next steps and open issues for research in order for these systems to become standard modules in tomorrow's vehicles.

  4. Harvesting entropy for random number generation for internet of things constrained devices using on-board sensors.

    Science.gov (United States)

    Pawlowski, Marcin Piotr; Jara, Antonio; Ogorzalek, Maciej

    2015-10-22

    Entropy in computer security is associated with the unpredictability of a source of randomness. The random source with high entropy tends to achieve a uniform distribution of random values. Random number generators are one of the most important building blocks of cryptosystems. In constrained devices of the Internet of Things ecosystem, high entropy random number generators are hard to achieve due to hardware limitations. For the purpose of the random number generation in constrained devices, this work proposes a solution based on the least-significant bits concatenation entropy harvesting method. As a potential source of entropy, on-board integrated sensors (i.e., temperature, humidity and two different light sensors) have been analyzed. Additionally, the costs (i.e., time and memory consumption) of the presented approach have been measured. The results obtained from the proposed method with statistical fine tuning achieved a Shannon entropy of around 7.9 bits per byte of data for temperature and humidity sensors. The results showed that sensor-based random number generators are a valuable source of entropy with very small RAM and Flash memory requirements for constrained devices of the Internet of Things.

  5. Towards Real-time, On-board, Hardware-Supported Sensor and Software Health Management for Unmanned Aerial Systems

    Science.gov (United States)

    Schumann, Johann; Rozier, Kristin Y.; Reinbacher, Thomas; Mengshoel, Ole J.; Mbaya, Timmy; Ippolito, Corey

    2013-01-01

    Unmanned aerial systems (UASs) can only be deployed if they can effectively complete their missions and respond to failures and uncertain environmental conditions while maintaining safety with respect to other aircraft as well as humans and property on the ground. In this paper, we design a real-time, on-board system health management (SHM) capability to continuously monitor sensors, software, and hardware components for detection and diagnosis of failures and violations of safety or performance rules during the flight of a UAS. Our approach to SHM is three-pronged, providing: (1) real-time monitoring of sensor and/or software signals; (2) signal analysis, preprocessing, and advanced on the- fly temporal and Bayesian probabilistic fault diagnosis; (3) an unobtrusive, lightweight, read-only, low-power realization using Field Programmable Gate Arrays (FPGAs) that avoids overburdening limited computing resources or costly re-certification of flight software due to instrumentation. Our implementation provides a novel approach of combining modular building blocks, integrating responsive runtime monitoring of temporal logic system safety requirements with model-based diagnosis and Bayesian network-based probabilistic analysis. We demonstrate this approach using actual data from the NASA Swift UAS, an experimental all-electric aircraft.

  6. A LOW BUDGET MOBILE LASER SCANNING SOLUTION USING ON BOARD SENSORS AND FIELD BUS SYSTEMS OF TODAY'S CONSUMER AUTOMOBILES

    Directory of Open Access Journals (Sweden)

    D. M. M. Vock

    2012-09-01

    Full Text Available Mobile laser scanning systems (MLS offer a great potential for acquiring detailed point cloud data of urban and suburban surroundings with minimum effort. In this paper a new solution for MLSs is presented, requiring solely a combination of a profile laser scanning device and systems that are included in today's serialized end consumer vehicles. While today's mobile laser scan systems require different and expensive additional hardware that needs to be mounted onto the vehicle, the devices included within vehicle electronics offer good alternatives without additional costs.The actual scan consists of a continuous profile scan together with information gathered from on-board sensor modules. In a post- processing step, the sensor data is used to reconstruct the car's trajectory for the period of the scan and, based on this information, the track of the scan device for every measured laser pixel. Synchronization of pixel data and vehicle movement is realized via a timestamp signal which is transmitted to the car's field bus system and the scan device. To generate the final point cloud scenario, the trajectory is interpolated for every single scan point and used to convert its local position within the profile into the global coordinate system (Fig.1, Left.

  7. Performances of Kevlar and Polyethylene as radiation shielding on-board the International Space Station in high latitude radiation environment.

    Science.gov (United States)

    Narici, Livio; Casolino, Marco; Di Fino, Luca; Larosa, Marianna; Picozza, Piergiorgio; Rizzo, Alessandro; Zaconte, Veronica

    2017-05-10

    Passive radiation shielding is a mandatory element in the design of an integrated solution to mitigate the effects of radiation during long deep space voyages for human exploration. Understanding and exploiting the characteristics of materials suitable for radiation shielding in space flights is, therefore, of primary importance. We present here the results of the first space-test on Kevlar and Polyethylene radiation shielding capabilities including direct measurements of the background baseline (no shield). Measurements are performed on-board of the International Space Station (Columbus modulus) during the ALTEA-shield ESA sponsored program. For the first time the shielding capability of such materials has been tested in a radiation environment similar to the deep-space one, thanks to the feature of the ALTEA system, which allows to select only high latitude orbital tracts of the International Space Station. Polyethylene is widely used for radiation shielding in space and therefore it is an excellent benchmark material to be used in comparative investigations. In this work we show that Kevlar has radiation shielding performances comparable to the Polyethylene ones, reaching a dose rate reduction of 32 ± 2% and a dose equivalent rate reduction of 55 ± 4% (for a shield of 10 g/cm2).

  8. Compositional uniformity of a Si0.5Ge0.5 crystal grown on board the International Space Station

    Science.gov (United States)

    Kinoshita, K.; Arai, Y.; Inatomi, Y.; Tsukada, T.; Miyata, H.; Tanaka, R.; Yoshikawa, J.; Kihara, T.; Tomioka, H.; Shibayama, H.; Kubota, Y.; Warashina, Y.; Ishizuka, Y.; Harada, Y.; Wada, S.; Ito, T.; Nagai, N.; Abe, K.; Sumioka, S.; Takayanagi, M.; Yoda, S.

    2015-06-01

    A Si0.5Ge0.5 crystal was grown on board the International Space Station (ISS) using the traveling liquidus-zone method. Average Ge concentration was 49±2 at% for the growth length of 14.5 mm. Radial compositional uniformity was excellent especially between the growth length of 3 and 9 mm; concentration fluctuation was less than 1 at%. In this experiment, cartridge surface temperatures were monitored and heater temperatures were adjusted based on the monitored temperatures for improving compositional uniformity of a grown crystal. A step temperature change by 1 °C was imposed for adjusting heater temperatures. This procedure made it possible to observe growth interface shape; striations due to heater temperature change were observed by a backscattered electron image. Growth rates were precisely determined by the relation between interval of heater temperature change and the distance between striations. Based on the measured growth rates, two-dimensional growth model for the traveling liquidus-zone method was discussed.

  9. Harvesting Entropy for Random Number Generation for Internet of Things Constrained Devices Using On-Board Sensors

    Directory of Open Access Journals (Sweden)

    Marcin Piotr Pawlowski

    2015-10-01

    Full Text Available Entropy in computer security is associated with the unpredictability of a source of randomness. The random source with high entropy tends to achieve a uniform distribution of random values. Random number generators are one of the most important building blocks of cryptosystems. In constrained devices of the Internet of Things ecosystem, high entropy random number generators are hard to achieve due to hardware limitations. For the purpose of the random number generation in constrained devices, this work proposes a solution based on the least-significant bits concatenation entropy harvesting method. As a potential source of entropy, on-board integrated sensors (i.e., temperature, humidity and two different light sensors have been analyzed. Additionally, the costs (i.e., time and memory consumption of the presented approach have been measured. The results obtained from the proposed method with statistical fine tuning achieved a Shannon entropy of around 7.9 bits per byte of data for temperature and humidity sensors. The results showed that sensor-based random number generators are a valuable source of entropy with very small RAM and Flash memory requirements for constrained devices of the Internet of Things.

  10. A review on on-board challenges of magnesium-based hydrogen storage materials for automobile applications

    Science.gov (United States)

    Rahman, Md. Wasikur

    2017-06-01

    The attempt of the review is to realize on-board hydrogen storage technologies concerning magnesium based solid-state matrix to allow fuel cell devices to facilitate sufficient storage capacity, cost, safety and performance requirements to be competitive with current vehicles. Hydrogen, a potential and clean fuel, can be applied in the state-of-the-art technology of `zero emission' vehicles. Hydrogen economy infrastructure both for stationary and mobile purposes is complicated due to its critical physico-chemical properties and materials play crucial roles in every stage of hydrogen production to utilization in fuel cells in achieving high conversion efficiency, safety and robustness of the technologies involved. Moreover, traditional hydrogen storage facilities are rather complicated due to its anomalous properties such as highly porous solids and polymers have intrinsic microporosity, which is the foremost favorable characteristics of fast kinetics and reversibility, but the major drawback is the low storage capacity. In contrast, metal hydrides and complex hydrides have high hydrogen storage capacity but thermodynamically unfavorable. Therefore, hydrogen storage is a real challenge to realize `hydrogen economy' that will solve the critical issues of humanity such as energy depletion, greenhouse emission, air pollution and ultimately climate change. Magnesium based materials, particularly magnesium hydride (MgH2) has been proposed as a potential hydrogen storage material due to its high gravimetric and volumetric capacity as well as environmentally benign properties to work the grand challenge out.

  11. Injecting faults to succeed. Verification of the boot software on-board solar orbiter's energetic particle detector

    Science.gov (United States)

    da Silva, Antonio; Sánchez, Sebastián; Polo, Óscar R.; Parra, Pablo

    2014-02-01

    It is said that even the longest journey begins with the first step. This is also true for application software. When the power is switched on, computer systems execute an initial set of operations that usually perform memory tests and load the final runtime environment. This paper describes the Single Event Effects (SEEs) requirements verification of the boot software that will run in the Instrument Control Unit (ICU) of the Energetic Particle Detector (EPD) on-board Solar Orbiter. Since in the booting stage there are no software services at all, it is difficult to achieve a complete software verification on real hardware. To shortcut this issue the Space Research Group (SRG) of the University of Alcalá has developed a LEON2 Virtual Platform (Leon2ViP) based on SystemC with fault injection capabilities. This way it is possible to run the exact same target binary software as if were run on the physical system, but in a controlled and deterministic environment, thus allowing a stricter requirements verification. The use of Leon2ViP has meant a significant improvement, in both time and cost, in the development and verification processes of the ICU's boot software.

  12. 40 CFR 86.1806-05 - On-board diagnostics for vehicles less than or equal to 14,000 pounds GVWR.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false On-board diagnostics for vehicles less than or equal to 14,000 pounds GVWR. 86.1806-05 Section 86.1806-05 Protection of Environment... HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From...

  13. The E-NIS instrument on-board the ESA Euclid Dark Energy Mission: a general view after positive conclusion of the assesment phase

    NARCIS (Netherlands)

    Valenziano, L.; Zerbi, F.M.; Cimatti, A.; Bianco, A.; Bonoli, C.; Bortoletto, F.; Bulgarelli, A.; Butler, R.C.; Content, R.; Corcione, L.; Rosa, A.de; Franzetti, P.; Garilli, B.; Gianotti, F.; Giro, E.; Grange, R.; Leutenegger, P.; Ligori, S.; Martin, L.; Mandolesi, N.; Morgante, G.; Nicastro, L.; Riva, M.; Robberto, M.; Sharples, R.; Spanó, P.; Talbot, G.; Trifoglio, M.; Wink, R.; Zamkotsian, F.

    2010-01-01

    The Euclid Near-Infrared Spectrometer (E-NIS) Instrument was conceived as the spectroscopic probe on-board the ESA Dark Energy Mission Euclid. Together with the Euclid Imaging Channel (EIC) in its Visible (VIS) and Near Infrared (NIP) declinations, NIS formed part of the Euclid Mission Concept

  14. Effects of on-board storage and electrical stunning of wild cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) on brain and heart activity

    NARCIS (Netherlands)

    Lambooij, E.; Digre, H.; Reimert, H.G.M.; Aursand, I.G.; Grimso, L.; Vis, van de J.W.

    2012-01-01

    Cod and haddock captured with commercial trawling gear were taken immediately after landing on deck to on-board storage in dry bins for measuring brain and heart activity, and behaviour. Other groups were first stored in holding tanks and then electrically stunned with a prototype "dry stunner". For

  15. Development of the science instrument CLUPI: the close-up imager on board the ExoMars rover

    Science.gov (United States)

    Josset, J.-L.; Beauvivre, S.; Cessa, V.; Martin, P.

    2017-11-01

    First mission of the Aurora Exploration Programme of ESA, ExoMars will demonstrate key flight and in situ enabling technologies, and will pursue fundamental scientific investigations. Planned for launch in 2013, ExoMars will send a robotic rover to the surface of Mars. The Close-UP Imager (CLUPI) instrument is part of the Pasteur Payload of the rover fixed on the robotic arm. It is a robotic replacement of one of the most useful instruments of the field geologist: the hand lens. Imaging of surfaces of rocks, soils and wind drift deposits at high resolution is crucial for the understanding of the geological context of any site where the Pasteur rover may be active on Mars. At the resolution provided by CLUPI (approx. 15 micrometer/pixel), rocks show a plethora of surface and internal structures, to name just a few: crystals in igneous rocks, sedimentary structures such as bedding, fracture mineralization, secondary minerals, details of the surface morphology, sedimentary bedding, sediment components, surface marks in sediments, soil particles. It is conceivable that even textures resulting from ancient biological activity can be visualized, such as fine lamination due to microbial mats (stromatolites) and textures resulting from colonies of filamentous microbes, potentially present in sediments and in palaeocavitites in any rock type. CLUPI is a complete imaging system, consisting of an APS (Active Pixel Sensor) camera with 27° FOV optics. The sensor is sensitive to light between 400 and 900 nm with 12 bits digitization. The fixed focus optics provides well focused images of 4 cm x 2.4 cm rock area at a distance of about 10 cm. This challenging camera system, less than 200g, is an independent scientific instrument linked to the rover on board computer via a SpaceWire interface. After the science goals and specifications presentation, the development of this complex high performance miniaturized imaging system will be described.

  16. The Moon observed in Energetic Neutral Atoms: Review of the Scientific Findings from SARA/CENA on board Chandrayaan-1

    Science.gov (United States)

    Vorburger, Audrey; Wurz, Peter; Barabash, Stas; Wieser, Martin; Futaana, Yoshifumi; Bhardwaj, Anil; Dhanya, Mb; Asamura, Kazushi

    2017-04-01

    The Sub-keV Atom Reflecting Analyzer (SARA) instrument on board Chandrayaan-1 was exceptionally successful. The instrument not only achieved all its set science goals but also revealed several hitherto unknown and unexpected properties of the solar wind interaction with the lunar surface. SARA's scientific findings can be divided into two groups based on the nature of the particles detected: The first group contains findings gained from ion measurements (from SWIM, SARA's ion sensor) whereas the second group contains findings gained from energetic neutral atom (ENA) measurements (from CENA, SARA's ENA sensor). Here, we present a review of all scientific findings based on ENA measurements. Since the Moon is constantly bombarded by solar wind ions. Until recently, it was tacitly assumed that the ions that impinge onto the lunar surface are almost completely absorbed, with less than 1% reflection, (e.g. Crider and Vondrak, Adv. Space Res., 2002; Feldman et al., JGR, 2000). However, recent observations conducted showed that on average 16% of the impinging solar wind ions are reflected as ENAs (e.g. McComas et al., GRL, 2009; Wieser et al., PSS, 2009; Vorburger et al., JGR, 2013). The energy spectrum of the reflected ENAs is broader than the spectrum of the incident solar wind protons (Futaana et al., JGR, 2012; Harada et al., JGR, 2014), and the characteristic energy is helium (Vorburger et al., JGR., 2012). With the backscattered proton signal being unexpectedly large, these signals are small in comparison, but persistent nevertheless. Finally, recent CENA data analyses showed that a significant fraction of the solar wind plasma is able to reach far into the lunar nightside surface: CENA measured a 30 deg broad ENA ring parallel to the terminator, with a total flux equal to 1.5% of the total dayside flux (Vorburger et al., GR., 2016). These measurements shed light onto the expansion of plasma into voids as they occur in planetary wakes.

  17. Estimated validity and reliability of on-board diagnostics for older vehicles: comparison with remote sensing observations.

    Science.gov (United States)

    Supnithadnaporn, Anupit; Noonan, Douglas S; Samoylov, Alexander; Rodgers, Michael O

    2011-10-01

    Based on requirements under the Clean Air Act Amendments of 1990, most state vehicle inspection and maintenance (I/M) programs have, since 2002, replaced the tailpipe emission testing with the on-board diagnostic (OBD) II testing for 1996 model and newer vehicles. This test relies on the OBD II system to give the pass or fail result, depending on certain conditions that might cause the vehicle to emit pollution 1.5 times higher than the regulated standard. The OBD II system is a computer and sensors installed in the vehicle to monitor the emission control units and signal if there is any malfunction. As a vehicle ages, its engine, pollution control units, and OBD II system deteriorate. Because the OBD II system's durability directly influences the test outcome, it is important to examine the fleetwide trend in the OBD II test results in comparison with an alternative measure of identifying high emitting vehicles. This study investigates whether the validity and reliability of the OBD II test is related to the age of the OBD II system installed in the fleet. Using Atlanta's I/M testing records and remote sensing device (RSD) data collected during 2002-2005, this research establishes the convergent validity and interobserver reliability criteria for the OBD II test based on on-road emissions measured by RSDs. The study results show that older vehicles exhibit significantly lower RSD-OBD II outcome agreement than newer vehicles. This suggests that the validity and reliability of the OBD II test may decline in the older vehicle fleets. Explanations and possible confounding factors for these findings are discussed.

  18. Mechanism controller system for the optical spectroscopic and infrared remote imaging system instrument on board the Rosetta space mission

    Science.gov (United States)

    Castro Marín, J. M.; Brown, V. J. G.; López Jiménez, A. C.; Rodríguez Gómez, J.; Rodrigo, R.

    2001-05-01

    The optical, spectroscopic infrared remote imaging system (OSIRIS) is an instrument carried on board the European Space Agency spacecraft Rosetta that will be launched in January 2003 to study in situ the comet Wirtanen. The electronic design of the mechanism controller board (MCB) system of the two OSIRIS optical cameras, the narrow angle camera, and the wide angle camera, is described here. The system is comprised of two boards mounted on an aluminum frame as part of an electronics box that contains the power supply and the digital processor unit of the instrument. The mechanisms controlled by the MCB for each camera are the front door assembly and a filter wheel assembly. The front door assembly for each camera is driven by a four phase, permanent magnet stepper motor. Each filter wheel assembly consists of two, eight filter wheels. Each wheel is driven by a four phase, variable reluctance stepper motor. Each motor, for all the assemblies, also contains a redundant set of four stator phase windings that can be energized separately or in parallel with the main windings. All stepper motors are driven in both directions using the full step unipolar mode of operation. The MCB also performs general housekeeping data acquisition of the OSIRIS instrument, i.e., mechanism position encoders and temperature measurements. The electronic design application used is quite new due to use of a field programmable gate array electronic devices that avoid the use of the now traditional system controlled by microcontrollers and software. Electrical tests of the engineering model have been performed successfully and the system is ready for space qualification after environmental testing. This system may be of interest to institutions involved in future space experiments with similar needs for mechanisms control.

  19. The impact of the board's strategy-setting role on board-management relations and hospital performance.

    Science.gov (United States)

    Büchner, Vera Antonia; Schreyögg, Jonas; Schultz, Carsten

    2014-01-01

    The appropriate governance of hospitals largely depends on effective cooperation between governing boards and hospital management. Governing boards play an important role in strategy-setting as part of their support for hospital management. However, in certain situations, this active strategic role may also generate discord within this relationship. The objective of this study is to investigate the impact of the roles, attributes, and processes of governing boards on hospital performance. We examine the impact of the governing board's strategy-setting role on board-management collaboration quality and on financial performance while also analyzing the interaction effects of board diversity and board activity level. The data are derived from a survey that was sent simultaneously to German hospitals and their associated governing board, combined with objective performance information from annual financial statements and quality reports. We use a structural equation modeling approach to test the model. The results indicate that different board characteristics have a significant impact on hospital performance (R = .37). The strategy-setting role and board-management collaboration quality have a positive effect on hospital performance, whereas the impact of strategy-setting on collaboration quality is negative. We find that the positive effect of strategy-setting on performance increases with decreasing board diversity. When board members have more homogeneous backgrounds and exhibit higher board activity levels, the negative effect of the strategy-setting on collaboration quality also increases. Active strategy-setting by a governing board may generally improve hospital performance. Diverse members of governing boards should be involved in strategy-setting for hospitals. However, high board-management collaboration quality may be compromised if managerial autonomy is too highly restricted. Consequently, hospitals should support board-management collaboration about

  20. Development status of the mechanical cryocoolers for the Soft X-ray Spectrometer on board Astro-H

    Science.gov (United States)

    Sato, Yoichi; Sawada, Kenichiro; Shinozaki, Keisuke; Sugita, Hiroyuki; Nishibori, Toshiyuki; Sato, Ryota; Mitsuda, Kazuhisa; Yamasaki, Noriko Y.; Takei, Yoh; Goto, Ken; Nakagawa, Takao; Fujimoto, Ryuichi; Kikuchi, Kenichi; Murakami, Masahide; Tsunematsu, Shoji; Ootsuka, Kiyomi; Kanao, Kenichi; Narasaki, Katsuhiro

    2014-11-01

    Astro-H is the Japanese X-ray astronomy satellite to be launched in 2015. The Soft X-ray Spectrometer (SXS) on board Astro-H is a high energy resolution spectrometer utilizing an X-ray micro-calorimeter array, which is operated at 50 mK by the ADR with the 30 liter superfluid liquid helium. The mechanical cryocoolers, 4 K-class Joule Thomson (JT) cooler and 20 K-class double-staged Stirling (2ST) cooler, are key components of the SXS cooling system to extend the lifetime of LHe cryogen beyond 3 years as required. Higher reliability was therefore investigated with higher cooling capability based on the heritage of existing cryocoolers. As the task of assessing further reliability dealt with the pipe-choking phenomena by contaminant solidification of the on-orbit SMILES JT cryocooler, outgassing from materials and component parts used in the cryocoolers was measured quantitatively to verify the suppression of carbon dioxide gas by their storage process and predict the total accumulated carbon dioxide for long-term operation. A continuous running test to verify lifetime using the engineering model (EM) of the 4 K-JT cooler is underway, having operated for a total of 720 days as of June 2013 and showing no remarkable change in cooling performance. During the current development phase, prototype models (PM) of the cryocoolers were installed to the test SXS dewar (EM) to verify the overall cooling performance from room temperature to 50 mK. During the EM dewar test, the requirement to reduce the transmitted vibration from the 2ST cooler compressor was recognized as mitigating the thermal instability of the SXS microcalorimeter at 50 mK.

  1. Tracking radiometric responsivity of optical sensors without on-board calibration systems-case of the Chinese HJ-1A/1B CCD sensors.

    Science.gov (United States)

    Li, Jian; Chen, Xiaoling; Tian, Liqiao; Feng, Lian

    2015-01-26

    The radiometric stability of satellite sensors is crucial for generating highly consistent remote sensing measurements and products. We have presented a radiometric responsivity tracking method designed especially for optical sensors without on-board calibration systems. Using a temporally stable desert site with high reflectance, the sensor responsivity was simulated using the Second Simulation of the Satellite Signal in the Solar Spectrum (6S) radiative transfer model (RTM) with information from validated MODIS atmospheric data. Next, radiometric responsivity drifting was identified using a linear regression of the time series bidirectional reflectance distribution function (BRDF) normalized coefficients. The proposed method was applied to Chinese HJ-1A/1B charge-coupled device (CCD) sensors, which have been on-orbit operations for more than 5 years without continuous assessment of their radiometric performance. Results from the Dunhuang desert site between 2008 and 2013 indicated that the CCD sensors degraded at various rates, with the most significant degradation occurring in the blue bands, ranging from 2.8% to 4.2% yr-1. The red bands were more stable, with a degradation rate of 0.7-3.1% yr-1. A cross-sensor comparison revealed the least degradation for the HJ-1A CCD1 (blue: 2.8%; green: 2.8%; red: 0.7%; and NIR: 0.9% yr-1), whereas the degradation of HJ-1B CCD1 was most pronounced (blue: 3.5%; green: 4.1%; red: 2.3%; and NIR: 3.4% yr-1). The uncertainties of the method were evaluated theoretically based on the propagation of uncertainties from all possible sources of the RT simulations. In addition, a cross comparison with matchup ground-based absolute calibration results was conducted. The comparison demonstrated that the method was useful for continuously monitoring the radiometric performance of remote sensors, such as HJ-1A/1B CCD and GaoFen (GF) series (China's latest high-definition Earth observation satellite), and indicated the potential use of the

  2. Angstrom-range optical path-length measurement with a high-speed scanning heterodyne optical interferometer.

    Science.gov (United States)

    Riza, Nabeel A; Arain, Muzammil A

    2003-05-01

    A highly accurate method of optical path-length measurement is introduced by use of a scanning heterodyne optical interferometer with no moving parts. The instrument has demonstrated the potential to measure optical path length at angstrom resolution over continuous thickness in the micrometer range. This optical path length can be used to calculate the thickness of any material if the refractive index is known or to measure the refractive index of the material if the thickness is known. The instrument uses a single acousto-optic device in an in-line ultra-stable reflective geometry to implement rapid scanning in the microsecond domain for thickness measurements of the test medium.

  3. Nocturnal atmospheric uv background measurements in the 300-400 nm band with baby 2001: a balloon borne experiment to flight on board of a transmediterranean balloon.

    Science.gov (United States)

    Giarrusso, S.; Agnetta, G.; Biondo, B.; Catalano, O.; Cusumano, G.; Gugliotta, G.; La Rosa, G.; Maccarone, M.C.; Mangano, A.; Russo, F.; Sacco, B.

    In the framework of the EUSO project (an experiment approved by ESA to be accommodate on board of the ISS) we present a new balloon borne experimental apparatus, named BABY 2001 that is devoted to systematic and exhaustive observations of the UV nocturnal atmospheric background. The BABY 2001 experiment is foreseen to flight on the 3rd 4th week of July 2001 from the Milo-Trapani base on board of a transmediterranean balloon, looking downward from about 40 km of altitude the dark nocturnal atmosphere over the sea. The apparatus used for the BABY 2001 experiment was designed and built at the IFCAI-CNR in Palermo. The instrument is composed by 8 filtered and collimated fast photomultipliers, two of them detecting the UV light in the 300-400 nm wavelengths band and the others in the three narrow bands centered at the emission lines of the atmospheric Nitrogen molecules.

  4. Radiated Emissions of the Power Converter Module of the Polarimetric and Helioseismic Imager Instrument On Board of Solar Orbiter: A Case Study

    Science.gov (United States)

    Sanchis Kilders, E.; Meller, R.; Lopez Jimenez, A.; Hirzberger, J.; Laget, Ph.; Gasent Blesa, J. L.; Herranz de la Revila, M.; Osorno Caudet, D.; Ferreres Sabater, A.; Balaguer Jimenez, M.; Jordan Martinez, J.; Esteve Gomez, V.; Maset Sancho, E.; Ejea Marti, J. B.

    2016-05-01

    EMC requirements for scientific satellites are usually very stringent and much more demanding than terrestrial standards, mainly because ad-hoc scientific instruments developed for the mission require very quiet electromagnetic environments to perform their science. These requirements will assure the compatibility of all instruments on board and with the platform.The electromagnetic noise generated by the DC/DC converter of the PHI instrument, to be flown on board Solar Orbiter, has been drastically reduced applying several different techniques.One technique has been to change the grounding strategy from a single point grounding to a distributed grounding. Two additional techniques were needed to reach the required noise floor.Experimental measurements show the improvements achieved with each technique.

  5. A statistical retrieval of cloud parameters for the millimeter wave Ice Cloud Imager on board MetOp-SG

    Science.gov (United States)

    Prigent, Catherine; Wang, Die; Aires, Filipe; Jimenez, Carlos

    2017-04-01

    The meteorological observations from satellites in the microwave domain are currently limited to below 190 GHz. However, the next generation of European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) Polar System-Second Generation-EPS-SG will carry an instrument, the Ice Cloud Imager (ICI), with frequencies up to 664 GHz, to improve the characterization of the cloud frozen phase. In this paper, a statistical retrieval of cloud parameters for ICI is developed, trained on a synthetic database derived from the coupling of a mesoscale cloud model and radiative transfer calculations. The hydrometeor profiles simulated with the Weather Research and Forecasting model (WRF) for twelve diverse European mid-latitude situations are used to simulate the brightness temperatures with the Atmospheric Radiative Transfer Simulator (ARTS) to prepare the retrieval database. The WRF+ARTS simulations have been compared to the Special Sensor Microwave Imager/Sounder (SSMIS) observations up to 190 GHz: this successful evaluation gives us confidence in the simulations at the ICI channels from 183 to 664 GHz. Statistical analyses have been performed on this simulated retrieval database, showing that it is not only physically realistic but also statistically satisfactory for retrieval purposes. A first Neural Network (NN) classifier is used to detect the cloud presence. A second NN is developed to retrieve the liquid and ice integrated cloud quantities over sea and land separately. The detection and retrieval of the hydrometeor quantities (i.e., ice, snow, graupel, rain, and liquid cloud) are performed with ICI-only, and with ICI combined with observations from the MicroWave Imager (MWI, with frequencies from 19 to 190 GHz, also on board MetOp-SG). The ICI channels have been optimized for the detection and quantification of the cloud frozen phases: adding the MWI channels improves the performance of the vertically integrated hydrometeor contents, especially for

  6. GIADA On-Board Rosetta: Early Dust Grain Detections and Dust Coma Characterization of Comet 67P/C-G

    Science.gov (United States)

    Rotundi, A.; Della Corte, V.; Accolla, M.; Ferrari, M.; Ivanovski, S.; Lucarelli, F.; Mazzotta Epifani, E.; Sordini, R.; Palumbo, P.; Colangeli, L.; Lopez-Moreno, J. J.; Rodriguez, J.; Fulle, M.; Bussoletti, E.; Crifo, J. F.; Esposito, F.; Green, S.; Grün, E.; Lamy, P. L.; McDonnell, T.; Mennella, V.; Molina, A.; Moreno, F.; Ortiz, J. L.; Palomba, E.; Perrin, J. M.; Rodrigo, R.; Weissman, P. R.; Zakharov, V.; Zarnecki, J.

    2014-12-01

    GIADA (Grain Impact Analyzer and Dust Accumulator) flying on-board Rosetta is devoted to study the cometary dust environment of 67P/Churiumov-Gerasimenko. GIADA is composed of 3 sub-systems: the GDS (Grain Detection System), based on grain detection through light scattering; an IS (Impact Sensor), giving momentum measurement detecting the impact on a sensed plate connected with 5 piezoelectric sensors; the MBS (MicroBalances System), constituted of 5 Quartz Crystal Microbalances (QCMs), giving cumulative deposited dust mass by measuring the variations of the sensors' frequency. The combination of the measurements performed by these 3 subsystems provides: the number, the mass, the momentum and the velocity distribution of dust grains emitted from the cometary nucleus.No prior in situ dust dynamical measurements at these close distances from the nucleus and starting from such large heliocentric distances are available up to date. We present here the first results obtained from the beginning of the Rosetta scientific phase. We will report dust grains early detection at about 800 km from the nucleus in August 2014 and the following measurements that allowed us characterizing the 67P/C-G dust environment at distances less than 100 km from the nucleus and single grains dynamical properties. Acknowledgements. GIADA was built by a consortium led by the Univ. Napoli "Parthenope" & INAF-Oss. Astr. Capodimonte, IT, in collaboration with the Inst. de Astrofisica de Andalucia, ES, Selex-ES s.p.a. and SENER. GIADA is presently managed & operated by Ist. di Astrofisica e Planetologia Spaziali-INAF, IT. GIADA was funded and managed by the Agenzia Spaziale Italiana, IT, with a support of the Spanish Ministry of Education and Science MEC, ES. GIADA was developped from a PI proposal supported by the University of Kent; sci. & tech. contribution given by CISAS, IT, Lab. d'Astr. Spat., FR, and Institutions from UK, IT, FR, DE and USA. We thank the RSGS/ESAC, RMOC/ESOC & Rosetta Project

  7. Regularities of the dynamic adjustment of hydromechanical transmission of off-highway dump trucks in creating the on-board diagnostic system

    OpenAIRE

    Rynkevich, S.

    2011-01-01

    The author offers a new approach in creating the on-board diagnostic system, which enables operative determination of the technical condition of hydro-mechanical transmissions of off-highway dump trucks of 45…60 t carrying capacity in the real time mode. The mathematical description of the processes of hydro-mechanical transmission operation is developed. Based on the simulation method, the regularities of dynamic adjustment of friction clutches during the automatic gearshift are revealed, wh...

  8. Practical solutions to the aircraft minimum fuel, fixed-range, fixed time-of-arrival trajectory optimization problem

    Science.gov (United States)

    Sorensen, J. A.; Waters, M. H.

    1980-01-01

    A practical scheme is presented for generating fixed range, minimum fuel vertical flight profiles that also satisfy time-of-arrival constraints. The resulting algorithm is suitable for incorporation into an on-board flight management system. Example results show that such a capability can save up to 6% of fuel burned in flights subject to delays because of terminal area congestion.

  9. Idling Reduction for Long-Haul Trucks: An Economic Comparison of On-Board and Wayside Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Gaines, Linda [Argonne National Lab. (ANL), Argonne, IL (United States); Weikersheimer, Patricia [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-09-01

    Reducing the idling of long-haul heavy-duty trucks has long been recognized as a particularly low-hanging fruit of fuel efficiency and emissions reduction. The displacement of about 10 hours of diesel idling every day, for most days of the year, for as many as a million long-haul trucks has very clear benefits. This report considers the costs and return on investment (ROI) for idling reduction (IR) equipment for both truck owners and electrified parking space (EPS) equipment owners. For the truck owners, the key variables examined are idling hours to be displaced (generally 1,000 to 2,000 hours per year) and the price of fuel ($0 to $5/gal). The ideal IR option would provide complete services in varied climates in any location and offer the best ROI on trucks that log many idling hours. For trucks that have fewer idling hours, options with a fixed cost per hour (i.e., EPS) might be most attractive if they were available to all, or even most, truck drivers. EPS, however, is particularly cost effective for trucks on prescribed routes with a need for regular, extended stops at terminals. (EPS is also called truck stop electrification, or TSE.) The analysis shows that all IR options save money when fuel costs more than $2/gal. For trucks requiring bunk heat, a simple heater (plug-in or diesel) is almost always the most costeffective way to provide heat, even if the truck is equipped with an auxiliary power unit (APU) or is parked at a single-system EPS location. For trucks requiring bunk air-conditioning, the use of single-system EPS is most cost effective for those logging fewer idling hours. Even for trucks with higher idling hours, the cost of EPS may be about the same as that for on-board air-conditioning. Clearly, trucks’ locations and seasonal factors—and the availability of EPS— are significant in the choice of “best fit” IR equipment for truck owners. This report also considers costs and payback for owners of EPS infrastructure. An industry that 5

  10. On Gamma Ray Instrument On-Board Data Processing Real-Time Computational Algorithm for Cosmic Ray Rejection

    Science.gov (United States)

    Kizhner, Semion; Hunter, Stanley D.; Hanu, Andrei R.; Sheets, Teresa B.

    2016-01-01

    gamma ray events and the problem is to detect and reject the much more voluminous cosmic ray projections, so that the remaining science data can be telemetered to the ground over the constrained communication link. The state-of-the-art in cosmic rays detection and rejection does not provide an adequate computational solution. This paper presents a novel approach to the AdEPT on-board data processing burdened with the CR detection top pole bottleneck problem. This paper is introducing the data processing object, demonstrates object segmentation and distribution for processing among many processing elements (PEs) and presents solution algorithm for the processing bottleneck - the CR-Algorithm. The algorithm is based on the a priori knowledge that a CR pierces the entire instrument pressure vessel. This phenomenon is also the basis for a straightforward CR simulator, allowing the CR-Algorithm performance testing. Parallel processing of the readout image's (2(N+M) - 4) peripheral voxels is detecting all CRs, resulting in O(n) computational complexity. This algorithm near real-time performance is making AdEPT class spaceflight instruments feasible.

  11. The multi-viewing, multi-channel, multi-polarisation imager on board the future EUMETSAT Polar System - Second Generation and its application for the aerosol retrieval

    Science.gov (United States)

    Kokhanovsky, Alexander; Munro, Rose; Lang, Ruediger; Lindstrot, Rasmus; Huckle, Roger; Marbach, Thierry; Poli, Gabriele

    2017-04-01

    Atmospheric aerosol is a global phenomenon. Due to the small size of aerosol particles (typically, 0.1 - 10 micrometers) they are rarely observed by the naked eye. Nevertheless aerosol particles are present in atmospheric air in variable numbers (typically, 100-1000 particles per cubic centimeter of atmospheric air). The particles have different chemical composition, origin, shapes, and internal structure (e.g., dust particles covered by ice, etc.). They influence human health, air quality, climate, downwelling and upwelling radiation, clouds, and precipitation. It is therefore important to monitor aerosol properties on a global scale. Global scale information can only be provided by satellite observations and algorithms for the production of satellite-based aerosol products have been in use already for more than 40 years. In this work we present an update on the recently developed operational EUMETSAT aerosol retrieval algorithm for the Multi-viewing, multi-channel, multi-polarisation Imager (3MI) which will fly on board the future EUMETSAT Polar System Second Generation (EPS-SG), planned for launch in the 2021 timeframe. The 3MI is a two - dimensional push - broom radiometer dedicated to aerosol and cloud characterization for climate monitoring, air quality forecasting and numerical weather prediction with heritage from the POLDER instrument. The first three components of the Stokes vector of the reflected light (I, Q, and U) will be measured at 9 channels in the spectral range from 410 to 2130nm for up to 14 observation directions. Intensity measurements only will be performed at 763, 765, and 910nm. This enables the determination of the degree of linear polarization of reflected light and also the direction of the oscillations of the electric vector in the light beam. The 3MI design consists of a filter and polariser wheel rotating in front of the detectors. For design purposes the spectral channels have been split into VNIR and SWIR filters and polarisers with

  12. TH-C-17A-12: Integrated CBCT and Optical Tomography System On-Board a Small Animal Radiation Research Platform (SARRP)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, K; Zhang, B; Eslami, S; Iordachita, I; Wong, J [Johns Hopkins University, Baltimore, MD (United States); Patterson, M [Hamilton Regional Cancer Ctr., Hamilton, ON (Canada)

    2014-06-15

    Purpose: We present a newly developed on-board optical tomography system for SARRP. Innovative features include the compact design and fast acquisition optical method to perform 3D soft tissue radiation guidance. Because of the on-board feature and the combination of the CBCT, diffusive optical tomography (DOT), bioluminescence and fluorescence tomography (BLT and FT), this integrated system is expected to provide more accurate soft tissue guidance than an off-line system as well as highly sensitive functional imaging in preclinical research. Methods: Images are acquired in the order of CBCT, DOT and then BLT/FT, where the SARRP CBCT and DOT are used to provide the anatomical and optical properties information to enhance the subsequent BLT/FT optical reconstruction. The SARRP stage is redesigned to include 9 imbedded optical fibers in contact with the animal's skin. These fibers, connected to a white light lamp or laser, serve as the light sources for the DOT or FT, respectively. A CCD camera with f/1.4 lens and multi-spectral filter set is used as the optical detector and is mounted on a portable cart ready to dock into the SARRP. No radiation is delivered during optical image acquisition. A 3-way mirror system capable of 180 degree rotation around the animal reflects the optical signal to the camera at multiple projection angles. A special black-painted dome covers the stage and provides the light shielding. Results: Spontaneous metastatic bioluminescent liver and lung tumor models will be used to validate the 3D BLT reconstruction. To demonstrate the capability of our FT system, GastroSense750 fluorescence agent will be used to imaging the mouse stomach and intestinal region in 3D. Conclusion: We expect that this integrated CBCT and optical tomography on-board a SARRP will present new research opportunities for pre-clinical radiation research. Supported by NCI RO1-CA 158100.

  13. HySDeP: a computational platform for on-board hydrogen storage systems – hybrid high-pressure solid-state and gaseous storage

    DEFF Research Database (Denmark)

    Mazzucco, Andrea; Rokni, Masoud

    2016-01-01

    A computational platform is developed in the Modelica® language within the DymolaTM environment to provide a tool for the design and performance comparison of on-board hydrogen storage systems. The platform has been coupled with an open source library for hydrogen fueling stations to investigate ...... to a storage capacity four times larger than a tube-in-tube solution of the same size. The volumetric and gravimetric densities of the shell and tube are 2.46% and 1.25% respectively. The dehydriding ability of this solution is proven to withstand intense discharging conditions....

  14. Image analysis in unmanned aerial vehicle on-board system for objects detection and recognition with the help of energy characteristics based on wavelet transform

    Science.gov (United States)

    Shleymovich, M. P.; Medvedev, M. V.; Lyasheva, S. A.

    2017-04-01

    In this article the problem of image analysis in unmanned aerial vehicle on-board system for objects detection and recognition with the help of energy characteristics based on wavelet transform is described. The approach of salient points extraction based on wavelet transform is proposed. The salience of the points is substantiated with the energy estimates of their weights. On the basis of wavelet transform salient points extraction the method of image contour segmentation is proposed. For further image recognition the salient points descriptors constructed with the help of wavelet transform are used. The objects detection and recognition system for unmanned aerial vehicles based on proposed methods is simulated using the simulation platform.

  15. Development of integrated, zero-G pneumatic transporter/rotating paddle incinerator/catalytic afterburner subsystem for processing human wastes on board spacecraft

    Science.gov (United States)

    Fields, S. F.; Labak, L. J.; Honegger, R. J.

    1974-01-01

    A four component system was developed which consists of a particle size reduction mechanism, a pneumatic waste transport system, a rotating-paddle incinerator, and a catalytic afterburner to be integrated into a six-man, zero-g subsystem for processing human wastes on board spacecraft. The study included the development of different concepts or functions, the establishment of operational specifications, and a critical evaluation for each of the four components. A series of laboratory tests was run, and a baseline subsystem design was established. An operational specification was also written in preparation for detailed design and testing of this baseline subsystem.

  16. Availability of feature-oriented scanning probe microscopy for remote-controlled measurements on board a space laboratory or planet exploration Rover.

    Science.gov (United States)

    Lapshin, Rostislav V

    2009-06-01

    Prospects for a feature-oriented scanning (FOS) approach to investigations of sample surfaces, at the micrometer and nanometer scales, with the use of scanning probe microscopy under space laboratory or planet exploration rover conditions, are examined. The problems discussed include decreasing sensitivity of the onboard scanning probe microscope (SPM) to temperature variations, providing autonomous operation, implementing the capabilities for remote control, self-checking, self-adjustment, and self-calibration. A number of topical problems of SPM measurements in outer space or on board a planet exploration rover may be solved via the application of recently proposed FOS methods.

  17. Findings from the PP-SESAME experiment on board the Philae/ROSETTA lander on the surface of comet 67P

    Science.gov (United States)

    Lethuillier, A.; Le Gall, A.; Hamelin, M.; Ciarletti, V.; Caujolle-Bert, S.; Schmidt, W.; Grard, R.; Fischer, H.; Seidensticker, K.

    2015-10-01

    The Permittivity Probe (PP-SESAME [1]) on-board the Philae Lander of the ROSETTA mission was designed to constrain the complex permittivity of the first 2 meters of the nucleus of comet 67P/Churyumov- Gerasimenko and to monitor its variations with time. Doing so, it is meant to provide unique insight into the composition (and activity if data could have been acquired longer) of the comet. In this paper, we present the analysis of the PP-SESAME measurements acquired during the first science sequence, on November 13, 2014, on the surface of the comet.

  18. Proposed Rule for Modification of Federal On Board Diagnostic Regulations for: Light Duty Vehicles, Light Duty Trucks, Medium Duty Passenger Vehicles, Complete Heavy Duty Vehicles and Engines Intended for Use in Heavy Duty Vehicles Weighing 14,000 Pounds

    Science.gov (United States)

    Following is information for the proposed rule for the Modification of Federal On Board Diagnostic Regulations for Light-Duty Vehicles, Light-Duty Trucks, etc. Includes links to Federal Register and final rule.

  19. Global comparisons between the modified Pathfinder derived sea surface temperature and skin temperatures from the along-track scanning radiometer on board ERS-2: how close are we getting?

    Science.gov (United States)

    Vazquez, J.

    2001-01-01

    Sea Surface Temperatures (SST) as derived from the Pathfinder Sea Surface Temperature Data Set and the Along-Track Scanning Radiometer on-board the European Remote Sensing Satellite provide a unique opportunity for comparing two independent SST data sets.

  20. Range management visual impacts

    Science.gov (United States)

    Bruce R. Brown; David Kissel

    1979-01-01

    Historical overgrazing of western public rangelands has resulted in the passage of the Public Rangeland Improvement Act of 1978. The main purpose of this Act is to improve unsatisfactory range conditions. A contributing factor to unfavorable range conditions is adverse visual impacts. These visual impacts can be identified in three categories of range management: range...

  1. On-board reforming of biodiesel and bioethanol for high temperature PEM fuel cells: Comparison of autothermal reforming and steam reforming

    Science.gov (United States)

    Martin, Stefan; Wörner, Antje

    2011-03-01

    In the 21st century biofuels will play an important role as alternative fuels in the transportation sector. In this paper different reforming options (steam reforming (SR) and autothermal reforming (ATR)) for the on-board conversion of bioethanol and biodiesel into a hydrogen-rich gas suitable for high temperature PEM (HTPEM) fuel cells are investigated using the simulation tool Aspen Plus. Special emphasis is placed on thermal heat integration. Methyl-oleate (C19H36O2) is chosen as reference substance for biodiesel. Bioethanol is represented by ethanol (C2H5OH). For the steam reforming concept with heat integration a maximum fuel processing efficiency of 75.6% (76.3%) is obtained for biodiesel (bioethanol) at S/C = 3. For the autothermal reforming concept with heat integration a maximum fuel processing efficiency of 74.1% (75.1%) is obtained for biodiesel (bioethanol) at S/C = 2 and λ = 0.36 (0.35). Taking into account the better dynamic behaviour and lower system complexity of the reforming concept based on ATR, autothermal reforming in combination with a water gas shift reactor is considered as the preferred option for on-board reforming of biodiesel and bioethanol. Based on the simulation results optimum operating conditions for a novel 5 kW biofuel processor are derived.

  2. Space qualification of an automotive microcontroller for the DREAMS-P/H pressure and humidity instrument on board the ExoMars 2016 Schiaparelli lander

    Science.gov (United States)

    Nikkanen, T.; Schmidt, W.; Harri, A.-M.; Genzer, M.; Hieta, M.; Haukka, H.; Kemppinen, O.

    2015-10-01

    Finnish Meteorological Institute (FMI) has developed a novel kind of pressure and humidity instrument for the Schiaparelli Mars lander, which is a part of the ExoMars 2016 mission of the European Space Agency (ESA) [1]. The DREAMS-P pressure instrument and DREAMS-H humidity instrument are part of the DREAMS science package on board the lander. DREAMS-P (seen in Fig. 1 and DREAMS-H were evolved from earlier planetary pressure and humidity instrument designs by FMI with a completely redesigned control and data unit. Instead of using the conventional approach of utilizing a space grade processor component, a commercial off the shelf microcontroller was selected for handling the pressure and humidity measurements. The new controller is based on the Freescale MC9S12XEP100 16-bit automotive microcontroller. Coordinated by FMI, a batch of these microcontroller units (MCUs) went through a custom qualification process in order to accept the component for spaceflight on board a Mars lander.

  3. A comprehensive review of on-board State-of-Available-Power prediction techniques for lithium-ion batteries in electric vehicles

    Science.gov (United States)

    Farmann, Alexander; Sauer, Dirk Uwe

    2016-10-01

    This study provides an overview of available techniques for on-board State-of-Available-Power (SoAP) prediction of lithium-ion batteries (LIBs) in electric vehicles. Different approaches dealing with the on-board estimation of battery State-of-Charge (SoC) or State-of-Health (SoH) have been extensively discussed in various researches in the past. However, the topic of SoAP prediction has not been explored comprehensively yet. The prediction of the maximum power that can be applied to the battery by discharging or charging it during acceleration, regenerative braking and gradient climbing is definitely one of the most challenging tasks of battery management systems. In large lithium-ion battery packs because of many factors, such as temperature distribution, cell-to-cell deviations regarding the actual battery impedance or capacity either in initial or aged state, the use of efficient and reliable methods for battery state estimation is required. The available battery power is limited by the safe operating area (SOA), where SOA is defined by battery temperature, current, voltage and SoC. Accurate SoAP prediction allows the energy management system to regulate the power flow of the vehicle more precisely and optimize battery performance and improve its lifetime accordingly. To this end, scientific and technical literature sources are studied and available approaches are reviewed.

  4. Ultrafast pump-probe microscopy with high temporal dynamic range.

    Science.gov (United States)

    Domke, Matthias; Rapp, Stephan; Schmidt, Michael; Huber, Heinz P

    2012-04-23

    Ultrafast pump-probe microscopy is a common method for time and space resolved imaging of short and ultra-short pulse laser ablation. The temporal delay between the ablating pump pulse and the illuminating probe pulse is tuned either by an optical delay, resulting in several hundred femtoseconds temporal resolution for delay times up to a few ns, or by an electronic delay, resulting in several nanoseconds resolution for longer delay times. In this work we combine both delay types for temporally high resolved observations of complete ablation processes ranging from femtoseconds to microseconds, while ablation is initiated by an ultrafast 660 fs laser pump pulse. For this purpose, we also demonstrate the calibration of the delay time zero point, the synchronization of both probe sources, as well as a method for image quality enhancing. In addition, we present for the first time to our knowledge pump-probe microscopy investigations of the complete substrate side selective ablation process of molybdenum films on glass. The initiation of mechanical film deformation is observed at about 400 ps, continues until approximately 15 ns, whereupon a Mo disk is sheared off free from thermal effects due to a directly induced laser lift-off ablation process. © 2012 Optical Society of America

  5. Minnesota Pheasant Range

    Data.gov (United States)

    Minnesota Department of Natural Resources — This dataset delineates the spatial range of wild pheasant populations in Minnesota as of 2002 by dividing the MN state boundary into 2 units: pheasant range and...

  6. Substring Range Reporting

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li

    2014-01-01

    We revisit various string indexing problems with range reporting features, namely, position-restricted substring searching, indexing substrings with gaps, and indexing substrings with intervals. We obtain the following main results. We give efficient reductions for each of the above problems...... to a new problem, which we call substring range reporting. Hence, we unify the previous work by showing that we may restrict our attention to a single problem rather than studying each of the above problems individually. We show how to solve substring range reporting with optimal query time and little...... for substring range reporting generalize to substring range counting and substring range emptiness variants. We also obtain non-trivial time-space trade-offs for these problems. Our bounds for substring range reporting are based on a novel combination of suffix trees and range reporting data structures...

  7. Simultaneous Laser Ranging and Communication from an Earth-Based Satellite Laser Ranging Station to the Lunar Reconnaissance Orbiter in Lunar Orbit

    Science.gov (United States)

    Sun, Xiaoli; Skillman, David R.; Hoffman, Evan D.; Mao, Dandan; McGarry, Jan F.; Neumann, Gregory A.; McIntire, Leva; Zellar, Ronald S.; Davidson, Frederic M.; Fong, Wai H.; hide

    2013-01-01

    We report a free space laser communication experiment from the satellite laser ranging (SLR) station at NASA Goddard Space Flight Center (GSFC) to the Lunar Reconnaissance Orbiter (LRO) in lunar orbit through the on board one-way Laser Ranging (LR) receiver. Pseudo random data and sample image files were transmitted to LRO using a 4096-ary pulse position modulation (PPM) signal format. Reed-Solomon forward error correction codes were used to achieve error free data transmission at a moderate coding overhead rate. The signal fading due to the atmosphere effect was measured and the coding gain could be estimated.

  8. Sirius: a long-range infrared search and track system

    Science.gov (United States)

    Knepper, R.

    1997-08-01

    Sirius is a long range infra red search and track system (LR- IRST) and intended to be used in an anti air warfare (AAW) multisensor suite on board of modern frigates. This Dutch/Canadian development program started 1/1/95 and includes also the evaluation of the system in warm and cold water scenarios. The operational requirements were drafted by both the national navies. The primary task is automatic detection, tracking and reporting of seaskimming missiles at long range. The design is based on recent experiences with IRSTs and the latest technological achievements in the areas of processing capabilities and IR-detectors. In this presentation design drivers and main technical choices are discussed.

  9. Applications of a Forward-Looking Interferometer for the On-board Detection of Aviation Weather Hazards

    Science.gov (United States)

    West, Leanne; Gimmestad, Gary; Smith, William; Kireev, Stanislav; Cornman, Larry B.; Schaffner, Philip R.; Tsoucalas, George

    2008-01-01

    The Forward-Looking Interferometer (FLI) is a new instrument concept for obtaining measurements of potential weather hazards to alert flight crews. The FLI concept is based on high-resolution Infrared (IR) Fourier Transform Spectrometry (FTS) technologies that have been developed for satellite remote sensing, and which have also been applied to the detection of aerosols and gases for other purposes. It is being evaluated for multiple hazards including clear air turbulence (CAT), volcanic ash, wake vortices, low slant range visibility, dry wind shear, and icing, during all phases of flight. Previous sensitivity and characterization studies addressed the phenomenology that supports detection and mitigation by the FLI. Techniques for determining the range, and hence warning time, were demonstrated for several of the hazards, and a table of research instrument parameters was developed for investigating all of the hazards discussed above. This work supports the feasibility of detecting multiple hazards with an FLI multi-hazard airborne sensor, and for producing enhanced IR images in reduced visibility conditions; however, further research must be performed to develop a means to estimate the intensities of the hazards posed to an aircraft and to develop robust algorithms to relate sensor measurables to hazard levels. In addition, validation tests need to be performed with a prototype system.

  10. One-chip analog circuits for a new type of plasma wave receiver on board space missions

    Science.gov (United States)

    Zushi, Takahiro; Kojima, Hirotsugu; Yamakawa, Hiroshi

    2017-03-01

    Plasma waves are important observational targets for scientific missions investigating space plasma phenomena. Conventional fast Fourier transform (FFT)-based spectrum plasma wave receivers have the disadvantages of a large size and a narrow dynamic range. This paper proposes a new type of FFT-based spectrum plasma wave receiver that overcomes the disadvantages of conventional receivers. The receiver measures and calculates the whole spectrum by dividing the observation frequency range into three bands: bands 1, 2, and 3, which span 1 Hz to 1 kHz, 1 to 10 kHz, and 10 to 100 kHz, respectively. To reduce the size of the receiver, its analog section was realized using application-specific integrated circuit (ASIC) technology, and an ASIC chip was successfully developed. The dimensions of the analog circuits were 4.21 mm × 1.16 mm. To confirm the performance of the ASIC, a test system for the receiver was developed using the ASIC, an analog-to-digital converter, and a personal computer. The frequency resolutions for bands 1, 2, and 3 were 3.2, 32, and 320 Hz, respectively, and the average time resolution was 384 ms. These frequency and time resolutions are superior to those of conventional FFT-based receivers.

  11. High-cadence observations of CME initiation and plasma dynamics in the corona with TESIS on board CORONAS-Photon

    Science.gov (United States)

    Bogachev, Sergey; Kuzin, Sergey; Zhitnik, I. A.; Bugaenko, O. I.; Goncharov, A. L.; Ignatyev, A. P.; Krutov, V. V.; Lomkova, V. M.; Mitrofanov, A. V.; Nasonkina, T. P.; Oparin, S. N.; Petzov, A. A.; Shestov, S. V.; Slemzin, V. A.; Soloviev, V. A.; Suhodrev, N. K.; Shergina, T. A.

    The TESIS is an ensemble of space instruments designed in Lebedev Institute of Russian Academy of Sciences for spectroscopic and imaging investigation of the Sun in EUV and soft X-ray spectral range with high spatial, temporal and spectral resolution. From 2009 January, when TESIS was launched onboard the Coronas-Photon satellite, it provided about 200 000 new images and spectra of the Sun, obtained during one of the deepest solar minimum in last century. Because of the wide field of view (4 solar radii) and high sensitivity, TESIS provided high-quality data on the origin and dynamics of eruptive prominences and CMEs in the low and intermediate solar corona. TESIS is also the first EUV instrument which provided high-cadence observations of coronal bright points and solar spicules with temporal resolution of a few seconds. We present first results of TESIS observations and discuss them from a scientific point of view.

  12. Intercomparison of aircraft instruments on board the C-130 and Falcon 20 over southern Germany during EXPORT 2000

    Directory of Open Access Journals (Sweden)

    N. Brough

    2003-01-01

    Full Text Available In the summer 2000 EXPORT aircraft campaign (European eXport of Precursors and Ozone by long-Range Transport, two comprehensively instrumented research aircraft measuring a variety of chemical species flew wing tip to wing tip for a period of one and a quarter hours. During this interval a comparison was undertaken of the measurements of nitrogen oxide (NO, odd nitrogen species (NOy, carbon monoxide (CO and ozone (O3. The comparison was performed at two different flight levels, which provided a 10-fold variation in the concentrations of both NO (10 to 1000 parts per trillion by volume (pptv and NOy (200 to over 2500 pptv. Large peaks of NO and NOy observed from the Falcon 20, which were at first thought to be from the exhaust of the C-130, were also detected on the 4 channel NOxy instrument aboard the C-130. These peaks were a good indication that both aircraft were in the same air mass and that the Falcon 20 was not in the exhaust plume of the C-130. Correlations and statistical analysis are presented between the instruments used on the two separate aircraft platforms. These were found to be in good agreement giving a high degree of correlation for the ambient air studied. Any deviations from the correlations are accounted for in the estimated inaccuracies of the instruments. These results help to establish that the instruments aboard the separate aircraft are reliably able to measure the corresponding chemical species in the range of conditions sampled and that data collected by both aircraft can be co-ordinated for purposes of interpretation.

  13. High-throughput optical inter-board interconnects for next-generation on-board digital transparent processors

    Science.gov (United States)

    Venet, N.; Sotom, M.; Gachon, H.; Foucal, V.; Pez, M.; Heikkinen, V.; Tuominen, T.; Pantoja, S.

    2017-11-01

    The satellite telecommunication sector is continuously facing new challenges. Operators turn towards increasing capacity payloads with higher number of beams and broader bandwidth, in order to cope with exhausting orbital positions and to lower the cost of in-orbit delivery of bit. Only satellites able to provide high data rate connections to numerous users are expected to achieve affordable communication prices. On the other hand, as the telecom market grows and the range of offered services (HDTV, Video On Demand, Triple Play), operators call for more versatile solutions to quickly grasp new markets and to adapt to these evolutions over the average 15 years of a satellite lifetime. Flexible payloads have found an increasing interest for a number of years. Flexibility is considered as a means for a better commercial exploitation of a satellite fleet and a better allocation of resource in response to traffic evolution and/or changing business plans, with potential advantages such as a wider range of applications, less customization for specific missions, increased production runs of equipment, enhancement of reliability, reduction of equipment cost, reduction of program schedules [1]. Flexibility is expected to be offered in spectrum management and frequency plan, in coverage, or in the repeater power allocation. The industry is taking up the challenge both by improving current telecom satellites and offering new payload technology, more flexible and able to address the new markets. From a system integrator perspective, flexibility is as an opportunity to design more generic payloads, that can be customized during or after fabrication only, thus shortening the design-to-manufacturing cycle, and improving the industry competitiveness.

  14. Substring Range Reporting

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li

    2011-01-01

    We revisit various string indexing problems with range reporting features, namely, position-restricted substring searching, indexing substrings with gaps, and indexing substrings with intervals. We obtain the following main results. – We give efficient reductions for each of the above problems...... to a new problem, which we call substring range reporting. Hence, we unify the previous work by showing that we may restrict our attention to a single problem rather than studying each of the above problems individually. – We show how to solve substring range reporting with optimal query time and little...... range reporting are based on a novel combination of suffix trees and range reporting data structures. The reductions are simple and general and may apply to other combinations of string indexing with range reporting....

  15. Compact Antenna Range

    Data.gov (United States)

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

  16. Dryden Aeronautical Test Range

    Data.gov (United States)

    Federal Laboratory Consortium — Recently redesignated to honor Dr. Hugh L. Dryden, NASA's Dryden Aeronautical Test Range (DATR) supports aerospace flight research and technology integration, space...

  17. Kinetic models of photosystem II should accommodate the effect of donor side quenching on variable chlorophyll a fluorescence in the microseconds time

    NARCIS (Netherlands)

    Vredenberg, W.J.

    2009-01-01

    Quantitative data on laser flash-induced variable fluorescence in the 100 ns to 1 ms time range (Belyaeva et al. in Photosynth Res 98:105–119, 2008) confirming those of others (Steffen et al. in Biochemistry 40:173–180, 2001, Biochemistry 44:3123–3132, 2005; Belyaeva et al. in Biophysics

  18. History of the solar particle event radiation doses on-board aeroplanes using a semi-empirical model and Concorde measurements

    Energy Technology Data Exchange (ETDEWEB)

    Lantos, P.; Fuller, N

    2003-07-01

    Measurements during solar particle events with dosemeters flying permanently on-board Concorde are used to develop a semi-empirical model, called SiGLE. The model is intended to calculate, for a given flight plan, the dose equivalent received during a solar particle event observed with ground-based neutron monitors. It is successfully in operation in the SIEVERT computerised system intended to improve monitoring of radiation dose received by aircrews, in application to a European Directive. The semi-empirical model is applied to evaluate, for most exposed routes, the radiation doses corresponding to the GLEs observed since 1942 with ion chambers or neutron monitors. The results for the largest GLEs observed in the past are discussed in terms of radiation risk, and guidelines are suggested concerning possible alerts to the aeroplanes in case of events of exceptional magnitude. (author)

  19. The European project Merlin on multi-gigabit, energy-efficient, ruggedized lightwave engines for advanced on-board digital processors

    Science.gov (United States)

    Stampoulidis, L.; Kehayas, E.; Karppinen, M.; Tanskanen, A.; Heikkinen, V.; Westbergh, P.; Gustavsson, J.; Larsson, A.; Grüner-Nielsen, L.; Sotom, M.; Venet, N.; Ko, M.; Micusik, D.; Kissinger, D.; Ulusoy, A. C.; King, R.; Safaisini, R.

    2017-11-01

    Modern broadband communication networks rely on satellites to complement the terrestrial telecommunication infrastructure. Satellites accommodate global reach and enable world-wide direct broadcasting by facilitating wide access to the backbone network from remote sites or areas where the installation of ground segment infrastructure is not economically viable. At the same time the new broadband applications increase the bandwidth demands in every part of the network - and satellites are no exception. Modern telecom satellites incorporate On-Board Processors (OBP) having analogue-to-digital (ADC) and digital-to-analogue converters (DAC) at their inputs/outputs and making use of digital processing to handle hundreds of signals; as the amount of information exchanged increases, so do the physical size, mass and power consumption of the interconnects required to transfer massive amounts of data through bulk electric wires.

  20. Mean vertical wind in the mesosphere-lower thermosphere region (80–120 km deduced from the WINDII observations on board UARS

    Directory of Open Access Journals (Sweden)

    V. Fauliot

    Full Text Available The WINDII interferometer placed on board the Upper Atmosphere Research Satellite measures temperature and wind from the O(1S green-line emission in the Earth's mesosphere and lower thermosphere. It is a remote-sensing instrument providing the horizontal wind components. In this study, the vertical winds are derived using the continuity equation. Mean wind annually averaged at equinoxes and solstices is shown. Ascendance and subsidence to the order of 1–2 cm s–1 present a seasonal occurrence at the equator and tropics. Zonal Coriolis acceleration and adiabatic heating and cooling rate associated to the mean meridional and vertical circulations are evaluated. The line emission rate measured together with the horizontal wind shows structures in altitude and latitude correlated with the meridional and vertical wind patterns. The effect of wind advection is discussed.

  1. Mean vertical wind in the mesosphere-lower thermosphere region (80–120 km deduced from the WINDII observations on board UARS

    Directory of Open Access Journals (Sweden)

    V. Fauliot

    1997-09-01

    Full Text Available The WINDII interferometer placed on board the Upper Atmosphere Research Satellite measures temperature and wind from the O(1S green-line emission in the Earth's mesosphere and lower thermosphere. It is a remote-sensing instrument providing the horizontal wind components. In this study, the vertical winds are derived using the continuity equation. Mean wind annually averaged at equinoxes and solstices is shown. Ascendance and subsidence to the order of 1–2 cm s–1 present a seasonal occurrence at the equator and tropics. Zonal Coriolis acceleration and adiabatic heating and cooling rate associated to the mean meridional and vertical circulations are evaluated. The line emission rate measured together with the horizontal wind shows structures in altitude and latitude correlated with the meridional and vertical wind patterns. The effect of wind advection is discussed.

  2. Seven Years of Permanent Running of MELFI-1 on Board the ISS and Utilisation of the Three MELFI Units Refrigeration Pool

    Science.gov (United States)

    Chegancas, Jean; Stephan, Hubertus; Jimenez, Jesus; Campana, Sharon; Hutchison, Susan

    2013-01-01

    The pool of three Minus Eighty Laboratory freezer for ISS (MELFI) units continues providing the scientific community with robust and permanent freezer and refrigeration capabilities for life science experiments on the International Space Station (ISS). Launched in 2006, the first unit will complete, by summer 2013, seven years of continuous operations without intervention on the internal Nitrogen gas cycle, while all necessary hardware and operations were initially planned for preventive maintenance every two years. This unit has demonstrated outstanding performance on orbit and proved the technical decisions made during the development program. Current utilization of MELFI units in the ISS is taking full benefit of the initial specifications, which allows for wide adaptations to cope with the mission scenario imposed by the life extension in orbit. The two other MELFI units, launched respectively in 2008 and 2009, are supporting the first unit providing additional conditioned volume necessary for the science on board, and also for preparing thermal mass used to protect the samples on their way down to earth. The MELFI pool is outfitted with all supporting hardware to allow for extended operation on orbit including preventive and corrective maintenance. The internal components were designed to allow for easy on board maintenance. Spare equipment was installed in the MELFI rack on ISS and specific maintenance means were developed which required crew training before the cold gas cycle could be accessed. The paper will present first how the design choices made for the initial missions are identifying features necessary for extended duration missions, and will then give highlights on the utilization of the MELFI refrigeration pool during the recent years in ISS.

  3. On Range of Skill

    DEFF Research Database (Denmark)

    Hansen, Thomas Dueholm; Miltersen, Peter Bro; Sørensen, Troels Bjerre

    2008-01-01

    size (and doubly exponential in its depth). We also provide techniques that yield concrete bounds for unbalanced game trees and apply these to estimate the Range of Skill of Tic-Tac-Toe and Heads-Up Limit Texas Hold'em Poker. In particular, we show that the Range of Skill of Tic-Tac-Toe is more than...

  4. Range Scheduling Aid (RSA)

    Science.gov (United States)

    Logan, J. R.; Pulvermacher, M. K.

    1991-01-01

    Range Scheduling Aid (RSA) is presented in the form of the viewgraphs. The following subject areas are covered: satellite control network; current and new approaches to range scheduling; MITRE tasking; RSA features; RSA display; constraint based analytic capability; RSA architecture; and RSA benefits.

  5. Home range and travels

    Science.gov (United States)

    Stickel, L.F.; King, John A.

    1968-01-01

    The concept of home range was expressed by Seton (1909) in the term 'home region,' which Burr (1940, 1943) clarified with a definition of home range and exemplified in a definitive study of Peromyscus in the field. Burt pointed out the ever-changing characteristics of home-range area and the consequent absence of boundaries in the usual sense--a finding verified by investigators thereafter. In the studies summarized in this paper, sizes of home ranges of Peromyscus varied within two magnitudes, approximately from 0.1 acre to ten acres, in 34 studies conducted in a variety of habitats from the seaside dunes of Florida to the Alaskan forests. Variation in sizes of home ranges was correlated with both environmental and physiological factors; with habitat it was conspicuous, both in the same and different regions. Food supply also was related to size of home range, both seasonally and in relation to habitat. Home ranges generally were smallest in winter and largest in spring, at the onset of the breeding season. Activity and size also were affected by changes in weather. Activity was least when temperatures were low and nights were bright. Effects of rainfall were variable. Sizes varied according to sex and age; young mice remained in the parents' range until they approached maturity, when they began to travel more widely. Adult males commonly had larger home ranges than females, although there were a number of exceptions. An inverse relationship between population density and size of home range was shown in several studies and probably is the usual relationship. A basic need for activity and exploration also appeared to influence size of home range. Behavior within the home range was discussed in terms of travel patterns, travels in relation to home sites and refuges, territory, and stability of size of home range. Travels within the home range consisted of repeated use of well-worn trails to sites of food, shelter, and refuge, plus more random exploratory travels

  6. Long range image enhancement

    CSIR Research Space (South Africa)

    Duvenhage, B

    2015-11-01

    Full Text Available and Vision Computing, Auckland, New Zealand, 23-24 November 2015 Long Range Image Enhancement Bernardt Duvenhage Council for Scientific and Industrial Research South Africa Email: bduvenhage@csir.co.za Abstract Turbulent pockets of air...

  7. SNOWY RANGE WILDERNESS, WYOMING.

    Science.gov (United States)

    Houston, Robert S.; Bigsby, Philip R.

    1984-01-01

    A mineral survey of the Snowy Range Wilderness in Wyoming was undertaken and was followed up with more detailed geologic and geochemical surveys, culminating in diamond drilling of one hole in the Snowy Range Wilderness. No mineral deposits were identified in the Snowy Range Wilderness, but inasmuch as low-grade uranium and associated gold resources were identified in rocks similar to those of the northern Snowy Range Wilderness in an area about 5 mi northeast of the wilderness boundary, the authors conclude that the northern half of the wilderness has a probable-resource potential for uranium and gold. Closely spaced drilling would be required to completely evaluate this mineral potential. The geologic terrane precludes the occurrence of fossil fuels.

  8. Atlantic Test Range (ATR)

    Data.gov (United States)

    Federal Laboratory Consortium — ATR controls fully-instrumented and integrated test ranges that provide full-service support for cradle-to-grave testing. Airspace and surface target areas are used...

  9. Light Detection And Ranging

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — LiDAR (Light Detection and Ranging) discrete-return point cloud data are available in the American Society for Photogrammetry and Remote Sensing (ASPRS) LAS format....

  10. On Range of Skill

    DEFF Research Database (Denmark)

    Hansen, Thomas Dueholm; Miltersen, Peter Bro; Sørensen, Troels Bjerre

    2008-01-01

    is a small number, but only gave heuristic arguments for this. In this paper, we provide the first methods for rigorously estimating the Range of Skill of a given game. We provide some general, asymptotic bounds that imply that the Range of Skill of a perfectly balanced game tree is almost exponential in its......At AAAI'07, Zinkevich, Bowling and Burch introduced the Range of Skill measure of a two-player game and used it as a parameter in the analysis of the running time of an algorithm for finding approximate solutions to such games. They suggested that the Range of Skill of a typical natural game...... size (and doubly exponential in its depth). We also provide techniques that yield concrete bounds for unbalanced game trees and apply these to estimate the Range of Skill of Tic-Tac-Toe and Heads-Up Limit Texas Hold'em Poker. In particular, we show that the Range of Skill of Tic-Tac-Toe is more than...

  11. TU-AB-303-10: KVCBCT, MVCBCT and MVCT On-Board Imaging Suitability for An Urgent Radiotherapy Treatment Workflow

    Energy Technology Data Exchange (ETDEWEB)

    Held, M; Morin, O; Pouliot, J [UC San Francisco, San Francisco, CA (United States)

    2015-06-15

    Purpose: A comparison of image quality and dose calculation accuracy to study the suitability of available on-board imaging systems for a new treatment workflow in emergency radiotherapy situations. Methods: Water and anthropomorphic phantom images were acquired on four different Linac on-board imaging systems, including kVCBCT (Varian TrueBeam and Elekta VersaHD), MVCBCT (Siemens Artiste) and MVCT (Accuray Tomotherapy). Simple treatments of single or opposed beams were planned on the respective kVCT images and copied to all CT images. Image suitability for dose planning was based on the overall mean dose differences and 3D gamma index with 3%/3mm criteria for a prescription of 100 monitor units (MU) and differences in calculated MUs per plan for dose prescriptions to mid-plane. Results: TrueBeam kVCBCT and Tomotherapy MVCT images produced most accurate dose calculation for all tested cases (γ-index >95%). MVCBCT and VersaHD kVCBCT images resulted in minimum γ-passing rates of 94% and 87%, respectively. MUs calculated from treatment plans prescribed to mid-plane were within differences of 5% relative to kVCT-based plans in all cases. However, VersaHD images showed considerable local image artifacts in the pelvis water and anthropomorphic neck phantom that complicated accurate Hounsfield unit (HU) to electron density conversion, thus causing local dose differences of more than 10% relative to kVCT-based dose distributions. Conclusion: TrueBeam kVCBCT, MVCBCT and MVCT systems provide image quality that allows for accurate simple treatment plan calculation. Prescription points should be placed away from areas found to cause local dose discrepancies, such as air cavities. Improved image filter settings and HU-to-electron density calibration adjustments may be required for the VersaHD system to obtain an overall accurate dose distribution. To evaluate a system’s overall suitability, its clinical features also require consideration, such as imaging field of view

  12. Range Selection and Median

    DEFF Research Database (Denmark)

    Jørgensen, Allan Grønlund; Larsen, Kasper Green

    2011-01-01

    that supports queries in constant time, needs n1+ (1) space. For data structures that uses n logO(1) n space this matches the best known upper bound. Additionally, we present a linear space data structure that supports range selection queries in O(log k= log log n + log log n) time. Finally, we prove that any...

  13. Electric vehicles: Driving range

    Science.gov (United States)

    Kempton, Willett

    2016-09-01

    For uptake of electric vehicles to increase, consumers' driving-range needs must be fulfilled. Analysis of the driving patterns of personal vehicles in the US now shows that today's electric vehicles can meet all travel needs on almost 90% of days from a single overnight charge.

  14. The Scoop on Board Diversity.

    Science.gov (United States)

    Holland, Robert, Jr.

    1996-01-01

    In an interview, a prominent college trustee discusses strategies for increasing ethnic and cultural diversity on governing boards, the relationship between board diversity and institutional policies, effects on the student body, the responsibility of the board, and the challenges and rewards of trusteeship. (MSE)

  15. Improvement in optical performance and color uniformity by optimizing the remote phosphor caps geometry for chip-on-board light emitting diodes

    Science.gov (United States)

    Li, Jiasheng; Li, Zongtao; Li, Zhi; Tang, Yong; Ding, Xinrui; Yu, Binhai

    2016-12-01

    The remote phosphor caps (RPCs) have been studied theoretically and experimentally based on chip-on-board (COB) devices. We have investigated the effect of RPCs on the blue light and the yellow light emission distributions by ray-tracing. Moreover, the geometry of RPCs have been optimized to simultaneously achieve an excellent optical performance and color uniformity. Corresponding to simulation results, both the optimized (conical shape without straight side) and the reference (semi-spherical shape with straight side) RPCs have been manufactured by the compression molding method. These RPCs were assembled to the same blue COB source and then the COB devices have been measured. Compared with the reference RPC, the optimized RPC is able to significantly increase the radiant power and the luminous flux by 15.9% and 17.0% at a driving current of 350 mA, respectively, and it can also decrease the standard deviation of the correlated color temperature (CCT) by 48.9% for a total CCT about 4800 K. Hence, the proposed RPCs can provide a superior improvement in optical performance and color uniformity to COB devices.

  16. Anthropogenic plumes from metropolitan areas and biomass burning emissions in West Africa during DACCIWA - airborne measurements on board the DLR Falcon 20

    Science.gov (United States)

    Stratmann, Greta; Schlager, Hans; Sauer, Daniel; Brocchi, Vanessa; Catoire, Valery; Baumann, Robert

    2017-04-01

    The DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions over West Africa) airborne field campaign was conducted in Southern West Africa in June/July 2016. Three European research aircraft (DLR - Falcon 20, SAFIRE - ATR 42 and BAS - Twin Otter) were deployed from Lomé/Togo and conducted research flights across Ivory Coast, Ghana, Togo and Benin. On board the DLR Falcon O3, SO2, CO, NO2 and aerosol fine mode particle number concentration and size distribution were measured during a total of 12 scientific flights. Until now only few airborne trace gas measurements were conducted in Southern West Africa. Therefore, this field experiment contributes to the knowledge of the chemical composition of the lower troposphere between 0 - 4 km. During several flights pollution plumes from major population centers - Lomé/Togo, Accra/Ghana, Kumasi/Ghana, and Abidjan/Ivory Coast - were probed below, inside and above clouds. Here, enhanced trace gas and particle concentrations were observed. In addition, plumes from biomass burning emissions were detected which were transported to West Africa. The composition of the pollution plumes are presented as well as transport pathways using HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectories) trajectory calculations. Ozone enhancements in the biomass burning pollution plumes of up to 70 ppb were observed compared to background concentrations of 30-40 ppb. Furthermore, HYSPLIT atmospheric dispersion simulations are used to estimate anthropogenic SO2 city emissions.

  17. On-board adaptive model for state of charge estimation of lithium-ion batteries based on Kalman filter with proportional integral-based error adjustment

    Science.gov (United States)

    Wei, Jingwen; Dong, Guangzhong; Chen, Zonghai

    2017-10-01

    With the rapid development of battery-powered electric vehicles, the lithium-ion battery plays a critical role in the reliability of vehicle system. In order to provide timely management and protection for battery systems, it is necessary to develop a reliable battery model and accurate battery parameters estimation to describe battery dynamic behaviors. Therefore, this paper focuses on an on-board adaptive model for state-of-charge (SOC) estimation of lithium-ion batteries. Firstly, a first-order equivalent circuit battery model is employed to describe battery dynamic characteristics. Then, the recursive least square algorithm and the off-line identification method are used to provide good initial values of model parameters to ensure filter stability and reduce the convergence time. Thirdly, an extended-Kalman-filter (EKF) is applied to on-line estimate battery SOC and model parameters. Considering that the EKF is essentially a first-order Taylor approximation of battery model, which contains inevitable model errors, thus, a proportional integral-based error adjustment technique is employed to improve the performance of EKF method and correct model parameters. Finally, the experimental results on lithium-ion batteries indicate that the proposed EKF with proportional integral-based error adjustment method can provide robust and accurate battery model and on-line parameter estimation.

  18. On-board orbit determination for low thrust LEO-MEO transfer by Consider Kalman Filtering and multi-constellation GNSS

    Science.gov (United States)

    Menzione, Francesco; Renga, Alfredo; Grassi, Michele

    2017-09-01

    In the framework of the novel navigation scenario offered by the next generation satellite low thrust autonomous LEO-to-MEO orbit transfer, this study proposes and tests a GNSS based navigation system aimed at providing on-board precise and robust orbit determination strategy to override rising criticalities. The analysis introduces the challenging design issues to simultaneously deal with the variable orbit regime, the electric thrust control and the high orbit GNSS visibility conditions. The Consider Kalman Filtering approach is here proposed as the filtering scheme to process the GNSS raw data provided by a multi-antenna/multi-constellation receiver in presence of uncertain parameters affecting measurements, actuation and spacecraft physical properties. Filter robustness and achievable navigation accuracy are verified using a high fidelity simulation of the low-thrust rising scenario and performance are compared with the one of a standard Extended Kalman Filtering approach to highlight the advantages of the proposed solution. Performance assessment of the developed navigation solution is accomplished for different transfer phases.

  19. A novel on-board state-of-charge estimation method for aged Li-ion batteries based on model adaptive extended Kalman filter

    Science.gov (United States)

    Sepasi, Saeed; Ghorbani, Reza; Liaw, Bor Yann

    2014-01-01

    A battery management system needs to have an accurate inline estimation of SOC for each individual cell in the battery pack. This estimation process poses challenges after substantial battery aging. This article presents a novel method based on model adaptive extended Kalman filter (MAEKF) to estimate SOC for Li-ion batteries. Sensitivity analysis of the electrical model verifies that the accuracy of SOC estimated by EKF is sensitive to resistors used in the cell's electrical model. In order to get the best estimation, values of resistors are obtained in an optimization process in the MAEKF. This method uses the fact of two sudden changes in the cell's voltage derivative with respect to time while discharging current is constant. These two points are assumed as reference points in which their SOC can be determined from cell's chemistry. The optimization algorithm uses the derivative of the cell's measured terminal voltage to allocate SOC of 92% and 15% for two reference points in the Vcell equation and updates cell's electrical model. The algorithm's process is fast and computationally inexpensive, making on-board estimation practical. The obtained results demonstrate that by using this method the estimated SOC error for aged Li-ion cells does not exceed 4%.

  20. A Whole-Genome Microarray Study of Arabidopsis thaliana Semisolid Callus Cultures Exposed to Microgravity and Nonmicrogravity Related Spaceflight Conditions for 5 Days on Board of Shenzhou 8

    Science.gov (United States)

    Neef, Maren; Ecke, Margret; Hampp, Rüdiger

    2015-01-01

    The Simbox mission was the first joint space project between Germany and China in November 2011. Eleven-day-old Arabidopsis thaliana wild type semisolid callus cultures were integrated into fully automated plant cultivation containers and exposed to spaceflight conditions within the Simbox hardware on board of the spacecraft Shenzhou 8. The related ground experiment was conducted under similar conditions. The use of an in-flight centrifuge provided a 1 g gravitational field in space. The cells were metabolically quenched after 5 days via RNAlater injection. The impact on the Arabidopsis transcriptome was investigated by means of whole-genome gene expression analysis. The results show a major impact of nonmicrogravity related spaceflight conditions. Genes that were significantly altered in transcript abundance are mainly involved in protein phosphorylation and MAPK cascade-related signaling processes, as well as in the cellular defense and stress responses. In contrast to short-term effects of microgravity (seconds, minutes), this mission identified only minor changes after 5 days of microgravity. These concerned genes coding for proteins involved in the plastid-associated translation machinery, mitochondrial electron transport, and energy production. PMID:25654111

  1. Development of the superconducting detectors and read-out for the X-IFU instrument on board of the X-ray observatory Athena

    Science.gov (United States)

    Gottardi, L.; Akamatsu, H.; Bruijn, M. P.; den Hartog, R.; den Herder, J.-W.; Jackson, B.; Kiviranta, M.; van der Kuur, J.; van Weers, H.

    2016-07-01

    The Advanced Telescope for High-Energy Astrophysics (Athena) has been selected by ESA as its second large-class mission. The future European X-ray observatory will study the hot and energetic Universe with its launch foreseen in 2028. Microcalorimeters based on superconducting Transition-edge sensor (TES) are the chosen technology for the detectors array of the X-ray Integral Field Unit (X-IFU) on board of Athena. The X-IFU is a 2-D imaging integral-field spectrometer operating in the soft X-ray band (0.3-12 keV). The detector consists of an array of 3840 TESs coupled to X-ray absorbers and read out in the MHz bandwidth using Frequency Domain Multiplexing (FDM) based on Superconducting QUantum Interference Devices (SQUIDs). The proposed design calls for devices with a high filling-factor, high quantum efficiency, relatively high count-rate capability and an energy resolution of 2.5 eV at 5.9 keV. The paper will review the basic principle and the physics of the TES-based microcalorimeters and present the state-of-the art of the FDM read-out.

  2. Development of the superconducting detectors and read-out for the X-IFU instrument on board of the X-ray observatory Athena

    Energy Technology Data Exchange (ETDEWEB)

    Gottardi, L., E-mail: l.gottardi@sron.nl [SRON Netherlands Institute for Space Research, Utrecht (Netherlands); Akamatsu, H.; Bruijn, M.P.; Hartog, R. den; Herder, J.-W. den; Jackson, B. [SRON Netherlands Institute for Space Research, Utrecht (Netherlands); Kiviranta, M. [VTT, Espoo (Finland); Kuur, J. van der; Weers, H. van [SRON Netherlands Institute for Space Research, Utrecht (Netherlands)

    2016-07-11

    The Advanced Telescope for High-Energy Astrophysics (Athena) has been selected by ESA as its second large-class mission. The future European X-ray observatory will study the hot and energetic Universe with its launch foreseen in 2028. Microcalorimeters based on superconducting Transition-edge sensor (TES) are the chosen technology for the detectors array of the X-ray Integral Field Unit (X-IFU) on board of Athena. The X-IFU is a 2-D imaging integral-field spectrometer operating in the soft X-ray band (0.3–12 keV). The detector consists of an array of 3840 TESs coupled to X-ray absorbers and read out in the MHz bandwidth using Frequency Domain Multiplexing (FDM) based on Superconducting QUantum Interference Devices (SQUIDs). The proposed design calls for devices with a high filling-factor, high quantum efficiency, relatively high count-rate capability and an energy resolution of 2.5 eV at 5.9 keV. The paper will review the basic principle and the physics of the TES-based microcalorimeters and present the state-of-the art of the FDM read-out.

  3. Microbial Monitoring from the Frontlines to Space: A Successful Validation of a Department of Defense (DoD) Funded Small Business Innovation Research (SBIR) Technology on Board the International Space Station (ISS)

    Science.gov (United States)

    Oubre, Cherie; Khodadad, Christina; Castro, Victoria; Ott, Mark; Pollack, Lawrence; Roman, Monsi

    2017-01-01

    The RAZOR EX (Registered Trademark) PCR unit was initially developed by the DoD as part of an SBIR project to detect and identify biothreats during field deployment. The system was evaluated by NASA as a commercial technology for future microbial monitoring requirements and has been successfully demonstrated in microgravity on-board the International Space Station.

  4. Long-range antigravity

    Energy Technology Data Exchange (ETDEWEB)

    Macrae, K.I.; Riegert, R.J. (Maryland Univ., College Park (USA). Center for Theoretical Physics)

    1984-10-01

    We consider a theory in which fermionic matter interacts via long-range scalar, vector and tensor fields. In order not to be in conflict with experiment, the scalar and vector couplings for a given fermion must be equal, as is natural in a dimensionally reduced model. Assuming that the Sun is not approximately neutral with respect to these new scalar-vector charges, and if the couplings saturate the experimental bounds, then their strength can be comparable to that of gravity. Scalar-vector fields of this strength can compensate for a solar quadrupole moment contribution to Mercury's anomalous perihelion precession.

  5. Online Sorted Range Reporting

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Fagerberg, Rolf; Greve, Mark

    2009-01-01

    We study the following one-dimensional range reporting problem: On an arrayA of n elements, support queries that given two indices i ≤ j and an integerk report the k smallest elements in the subarray A[i..j] in sorted order. We present a data structure in the RAM model supporting such queries...... in optimal O(k) time. The structure uses O(n) words of space and can be constructed in O(n logn) time. The data structure can be extended to solve the online version of the problem, where the elements in A[i..j] are reported one-by-one in sorted order, in O(1) worst-case time per element. The problem...... is motivated by (and is a generalization of) a problem with applications in search engines: On a tree where leaves have associated rank values, report the highest ranked leaves in a given subtree. Finally, the problem studied generalizes the classic range minimum query (RMQ) problem on arrays....

  6. Lightning detection and ranging

    Science.gov (United States)

    Lennon, C. L.; Poehler, H. A.

    1982-01-01

    A lightning detector and ranging (LDAR) system developed at the Kennedy Space Center and recently transferred to Wallops Island is described. The system detects pulsed VHF signals due to electrical discharges occurring in a thunderstorm by means of 56-75 MHz receivers located at the hub and at the tips of 8 km radial lines. Incoming signals are transmitted by wideband links to a central computing facility which processes the times of arrival, using two independent calculations to determine position in order to guard against false data. The results are plotted on a CRT display, and an example of a thunderstorm lightning strike detection near Kennedy Space Center is outlined. The LDAR correctly identified potential ground strike zones and additionally provided a high correlation between updrafts and ground strikes.

  7. The Development and Optimization of Techniques for Monitoring Water Quality on-Board Spacecraft Using Colorimetric Solid-Phase Extraction (C-SPE)

    Energy Technology Data Exchange (ETDEWEB)

    Hill, April Ann [Iowa State Univ., Ames, IA (United States)

    2007-12-01

    The main focus of this dissertation is the design, development, and ground and microgravity validation of methods for monitoring drinking water quality on-board NASA spacecraft using clorimetric-solid phase extraction (C-SPE). The Introduction will overview the need for in-flight water quality analysis and will detail some of the challenges associated with operations in the absence of gravity. The ability of C-SPE methods to meet these challenges will then be discussed, followed by a literature review on existing applications of C-SPE and similar techniques. Finally, a brief discussion of diffuse reflectance spectroscopy theory, which provides a means for analyte identification and quantification in C-SPE analyses, is presented. Following the Introduction, four research chapters are presented as separate manuscripts. Chapter 1 reports the results from microgravity testing of existing C-SPE methods and procedures aboard NASA's C-9 microgravity simulator. Chapter 2 discusses the development of a C-SPE method for determining the total concentration of biocidal silver (i.e., in both dissolved and colloidal forms) in water samples. Chapter 3 presents the first application of the C-SPE technique to the determination of an organic analyte (i.e., formaldehyde). Chapter 4, which is a departure from the main focus of the thesis, details the results of an investigation into the effect of substrate rotation on the kinetics involved in the antigen and labeling steps in sandwich immunoassays. These research chapters are followed by general conclusions and a prospectus section.

  8. Recovering from "amnesia" brought about by radiation. Verification of the "Over the air" (OTA) application software update mechanism On-Board Solar Orbiter's Energetic Particle Detector

    Science.gov (United States)

    Da Silva, Antonio; Sánchez Prieto, Sebastián; Rodriguez Polo, Oscar; Parra Espada, Pablo

    Computer memories are not supposed to forget, but they do. Because of the proximity of the Sun, from the Solar Orbiter boot software perspective, it is mandatory to look out for permanent memory errors resulting from (SEL) latch-up failures in application binaries stored in EEPROM and its SDRAM deployment areas. In this situation, the last line in defense established by FDIR mechanisms is the capability of the boot software to provide an accurate report of the memories’ damages and to perform an application software update, that avoid the harmed locations by flashing EEPROM with a new binary. This paper describes the OTA EEPROM firmware update procedure verification of the boot software that will run in the Instrument Control Unit (ICU) of the Energetic Particle Detector (EPD) on-board Solar Orbiter. Since the maximum number of rewrites on real EEPROM is limited and permanent memory faults cannot be friendly emulated in real hardware, the verification has been accomplished by the use of a LEON2 Virtual Platform (Leon2ViP) with fault injection capabilities and real SpaceWire interfaces developed by the Space Research Group (SRG) of the University of Alcalá. This way it is possible to run the exact same target binary software as if was run on the real ICU platform. Furthermore, the use of this virtual hardware-in-the-loop (VHIL) approach makes it possible to communicate with Electrical Ground Support Equipment (EGSE) through real SpaceWire interfaces in an agile, controlled and deterministic environment.

  9. Detection of Esophageal Fiducial Marker Displacement During Radiation Therapy With a 2-dimensional On-board Imager: Analysis of Internal Margin for Esophageal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Fukada, Junichi, E-mail: fukada@rad.med.keio.ac.jp [Department of Radiology, School of Medicine, Keio University, Tokyo (Japan); Hanada, Takashi; Kawaguchi, Osamu; Ohashi, Toshio [Department of Radiology, School of Medicine, Keio University, Tokyo (Japan); Takeuchi, Hiroya; Kitagawa, Yuko [Department of Surgery, School of Medicine, Keio University, Tokyo (Japan); Seki, Satoshi; Shiraishi, Yutaka [Department of Radiology, School of Medicine, Keio University, Tokyo (Japan); Ogata, Haruhiko [Center for Diagnostic and Therapeutic Endoscopy, School of Medicine, Keio University, Tokyo (Japan); Shigematsu, Naoyuki [Department of Radiology, School of Medicine, Keio University, Tokyo (Japan)

    2013-03-15

    Purpose: To quantify the interfraction displacement of esophageal fiducial markers for primary esophageal cancer radiation therapy. Methods and Materials: Orthogonal 2-dimensional (2D) matching records fused to vertebrae were analyzed in clinically staged T1/2N0 esophageal cancer patients undergoing endoscopic clipping as fiducial metal markers. Displacement of the markers between the digitally reconstructed radiographs and on-board kilovoltage images during radiation therapy was analyzed according to direction and esophageal site. Results: Forty-four patients, with 81 markers (10 proximal, 42 middle, and 29 distal), underwent 367 2D matching sessions during radiation therapy. The mean (SD) absolute marker displacement was 0.26 (0.30) cm in the right–left (RL), 0.50 (0.39) cm in the superior–inferior (SI), and 0.24 (0.21) cm in the anterior–posterior (AP) direction. Displacement was significantly larger in the SI than in the RL and AP directions (P<.0001). In the SI direction, mean absolute displacements of the distal, middle, and proximal esophagus were 0.67 (0.45) cm, 0.42 (0.32) cm, and 0.36 (0.30) cm, respectively. Distal esophagus displacement was significantly larger than those of the middle and proximal esophagus (P<.0001). The estimated internal margin to cover 95% of the cases was 0.75 cm in the RL and AP directions. In the SI direction, the margin was 1.25 cm for the proximal and middle esophagus and 1.75 cm for the distal esophagus. Conclusions: The magnitude of interfraction displacement of esophageal clips was larger in the SI direction, particularly in the distal esophagus, but substantial displacement was observed in other directions and at other esophageal sites. It is practical to take estimated movements into account with internal margins, even if vertebrae-based 2D matching is performed.

  10. A Numerical Analysis of the Air Distribution System for the Ventilation of the Crew Quarters on board of the International Space Station

    Directory of Open Access Journals (Sweden)

    Bode Florin

    2018-01-01

    Full Text Available Quality of life on the International Space Station (ISS has become more and more important, since the time spent by astronauts outside the terrestrial atmosphere has increased in the last years. The actual concept for the Crew Quarters (CQ have demonstrated the possibility of a personal space for sleep and free time activities in which the noise levels are lower, but not enough, compared to the noisy ISS isle way. However, there are several issues that needs to be improved to increase the performance of CQ. Our project QUEST is intended to propose a new concept of CQ in which we will correct these issues, like the noise levels will be lower, more space for astronaut, increased thermal comfort, reduce the CQ total weight, higher efficiency for the air distribution, personalized ventilation system in CQ for the crew members in order to remove CO2 from the breathing zone. This paper presents a CFD study in which we are comparing the actual and a proposed ventilation solution for introducing the air in CQ. A preliminary numerical model of the present configuration of the air distribution system of the Crew Quarters on board of the ISS, shows the need for an improved air distribution inside these enclosures. Lower velocity values at the inlet diffuser, distributed over a larger surface, as well as diffusers with improved induction would appear to be a better choice. This was confirmed through the development of a new model including linear diffusers with a larger discharge surface. In this new configuration, the regions of possible draught are dramatically reduced. The overall distributions of the velocity magnitudes displaying more uniform, lower values, in the same time with more uniform temperatures. All these observations allow us to consider a better mixing of the air inside the enclosure.

  11. Kiel sensors for the EPD instrument on-board Solar Orbiter - An overview of the qualification and acceptance test campaigns in phase D

    Science.gov (United States)

    Ravanbakhsh, A.; Kulkarni, S. R.; Panitzsch, L.; L Richards, M.; Munoz Hernandez, A.; Seimetz, L.; Elftmann, R.; Mahesh, Y.; Boden, S.; Boettcher, S. I.; Kulemzin, A.; Martin-Garcia, C.; Prieto, M.; Rodriguez-Pacheco, J.; Sanchez Prieto, S.; Schuster, B.; Steinhagen, J.; Tammen, J.; Wimmer-Schweingruber, R. F.

    2016-12-01

    Solar Orbiter is ESA's next solar and heliospheric mission which is planned to be launched in October 2018. The Energetic Particle Detector (EPD) on board on Solar Orbiter will provide key measurements for the Solar Orbiter science objectives. The EPD suite consists of four sensors; STEP, SIS, EPT and HET. The University of Kiel in Germany is responsible for the design, development, and building of STEP, and the two identical units EPT-HET 1 and EPT-HET 2. ESA's Solar Orbiter will explore the heliosphere at heliocentric distances between 0.28AU and 0.9AU and with inclination up to 38deg with respect to the Sun's equator. The spacecraft uses a heat shield to protect the bus and externally mounted instruments from the solar flux at the close distances to the sun. All three EPD-Kiel units are mounted externally but in different positions on the spacecraft outer deck. Although being protected by the spacecraft heat shield from high solar flux, EPT-HET1 and EPT-HET-2 as well as STEP experience a harsh environmental condition during the course of the mission. In addition due to the highly demanding science requirements, the qualification and acceptance test requirements of these externally mounted units are quite challenging. In this paper we present the development status of the EPT-HET 1, EPT-HET 2 and STEP sensors focusing on the activities performed in phase D and the qualification and acceptance test campaigns. The main objective of these test campaigns is to ensure and demonstrate the compatibility between the scientific requirements and the harsh environment expected during the mission. This paper includes the results summary of the environmental tests on the EPT-HET and STEP Proto-Qualification Models (PQMs) as well as Proto-Flight Models (PFMs). Only an adequate selection of environmental qualification and acceptance campaigns will guarantee the success of the scientific space missions.

  12. Measuring the Permittivity of the Nucleus of a Comet: the PP-SESAME Experiment on Board the Philae/ROSETTA Lander

    Science.gov (United States)

    Lethuillier, A.; Le Gall, A. A.; Hamelin, M.; Ciarletti, V.; Caujolle-Bert, S.; Schmidt, W.; Grard, R.; Seidensticker, K. J.; Fischer, H. H.

    2015-12-01

    The Permittivity Probe (SESAME-PP) on-board the Philae Lander of the ROSETTA mission was designed to constrain the complex permittivity of the first 2 m of the nucleus of comet 67P/Churyumov-Gerasimenko and to monitor its variations with time. Doing so, it is meant to provide a unique insight into the composition of the comet, and in particular, into its water content. PP-SESAME acquired data on November 13, 2015, both during Philae descent to the comet and at the surface of the nucleus. The PP-SESAME instrument is derived from the quadrupole array technique. A sinusoidal electrical current is sent into the ground through a transmitting dipole, and the induced electrical voltage on a receiving dipole is measured. The complex permittivity of the material is inferred from the mutual impedance derived from the measurements. In practice, the influence of both the electronic circuit of the instrument and the conducting elements in its close environment must be accounted for in order to best estimate both the dielectric constant and electrical conductivity of the ground. For that purpose, we have developed a method called the "capacity-influence matrix method". A replica of the instrument was recently built in LATMOS (France) in order to validate this method. In this paper, we will present the tests conducted with the replica in a controlled environment and their comparison to numerical simulations. We will also show simulations relevant to the PP-SESAME experiment on the nucleus of comet 67P/Churyumov-Gerasimenko. These simulations were run for realistic scenarios of the Philae's attitude and environment at its final landing site. We discuss their implications in terms of surface electrical and compositional properties.

  13. TU-AB-BRA-09: A Novel Method of Generating Ultrafast Volumetric Cine MRI (VC-MRI) Using Prior 4D-MRI and On-Board Phase-Skipped Encoding Acquisition for Radiotherapy Target Localization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C; Yin, F; Harris, W; Cai, J; Chang, Z; Ren, L [Duke University Medical Center, Durham, NC (United States)

    2016-06-15

    Purpose: To develop a technique generating ultrafast on-board VC-MRI using prior 4D-MRI and on-board phase-skipped encoding k-space acquisition for real-time 3D target tracking of liver and lung radiotherapy. Methods: The end-of-expiration (EOE) volume in 4D-MRI acquired during the simulation was selected as the prior volume. 3 major respiratory deformation patterns were extracted through the principal component analysis of the deformation field maps (DFMs) generated between EOE and all other phases. The on-board VC-MRI at each instant was considered as a deformation of the prior volume, and the deformation was modeled as a linear combination of the extracted 3 major deformation patterns. To solve the weighting coefficients of the 3 major patterns, a 2D slice was extracted from VC-MRI volume to match with the 2D on-board sampling data, which was generated by 8-fold phase skipped-encoding k-space acquisition (i.e., sample 1 phase-encoding line out of every 8 lines) to achieve an ultrafast 16–24 volumes/s frame rate. The method was evaluated using XCAT digital phantom to simulate lung cancer patients. The 3D volume of end-ofinhalation (EOI) phase at the treatment day was used as ground-truth onboard VC-MRI with simulated changes in 1) breathing amplitude and 2) breathing amplitude/phase change from the simulation day. A liver cancer patient case was evaluated for in-vivo feasibility demonstration. Results: The comparison between ground truth and estimated on-board VC-MRI shows good agreements. In XCAT study with changed breathing amplitude, the volume-percent-difference(VPD) between ground-truth and estimated tumor volumes at EOI was 6.28% and the Center-of-Mass-Shift(COMS) was 0.82mm; with changed breathing amplitude and phase, the VPD was 8.50% and the COMS was 0.54mm. The study of liver patient case also demonstrated a promising in vivo feasibility of the proposed method Conclusion: Preliminary results suggest the feasibility to estimate ultrafast VC-MRI for on-board

  14. Assessing the Impacts of the First Five Years of School of Rock On-Board and On-Shore Professional Development Program for Educators: Lessons for Other Teacher Professional Development Programs

    Science.gov (United States)

    Collins, J.; Peart, L. W.; Cooper, S. K.; St John, K. K.; Leckie, R. M.; Hovan, S. A.; Firth, J. V.

    2011-12-01

    School of Rock (SoR) is an immersive professional development program run by the Deep Earth Academy (DEA) of the Consortium for Ocean Leadership. The program offers formal and informal educators an opportunity to utilize the laboratories, cores, smear slides, and other data on the JOIDES Resolution research vessel and Texas A&M Gulf Coast Repository to investigate Earth science topics aligned with the IODP science goals. Participants acquire content and skills through inquiry explorations facilitated by scientist instructors and lab technicians, and are exposed to the culture of onshore and offshore science by interacting with experts from a range of scientific and non-scientific disciplines. Since 2005, the School of Rock program has hosted over 60 participants from 33 states and four countries. Several of the SoR programs had on-board experiences, while others were held on-shore at the IODP's Gulf Coast Repository. The participant demographics varied in each cohort as did some of science content focus and pedagogical approach. To assess the impact of the SoR experience on participants and their classrooms, and inform DEA about how to proceed with future SoR programs, past participants recently completed two online surveys. Data were analyzed in the context of three guiding questions: What important qualities have been consistent across the years?, What are some key differences between the SoR programs?, What are the key differences between shore-based and onboard experiences?. Additionally, participants documented the number of activities they developed, workshops given, and other efforts that share their SoR experience with their respective audiences. The survey results and ensuing discussions with a focus group of program participants representing each of the cohorts suggest to our surprise, that participants in on-shore experiences were similarly satisfied and enthusiastic about their learning experience as those that participated in shipboard SoRs, even

  15. Enhanced tropospheric BrO over Antarctic sea ice in mid winter observed by MAX-DOAS on board the research vessel Polarstern

    Directory of Open Access Journals (Sweden)

    T. Wagner

    2007-06-01

    Full Text Available We present Multi AXis-Differential Optical Absorption Spectroscopy (MAX-DOAS observations of tropospheric BrO carried out on board the German research vessel Polarstern during the Antarctic winter 2006. Polarstern entered the area of first year sea ice around Antarctica on 24 June 2006 and stayed within this area until 15 August 2006. For the period when the ship cruised inside the first year sea ice belt, enhanced BrO concentrations were almost continuously observed. Outside the first year sea ice belt, typically low BrO concentrations were found. Based on back trajectory calculations we find a positive correlation between the observed BrO differential slant column densities (ΔSCDs and the duration for which the air masses had been in contact with the sea ice surface prior to the measurement. While we can not completely rule out that in several cases the highest BrO concentrations might be located close to the ground, our observations indicate that the maximum BrO concentrations might typically exist in a (possibly extended layer around the upper edge of the boundary layer. Besides the effect of a decreasing pH of sea salt aerosol with altitude and therefore an increase of BrO with height, this finding might be also related to vertical mixing of air from the free troposphere with the boundary layer, probably caused by convection over the warm ocean surface at polynyas and cracks in the ice. Strong vertical gradients of BrO and O3 could also explain why we found enhanced BrO levels almost continuously for the observations within the sea ice. Based on our estimated BrO profiles we derive BrO mixing ratios of several ten ppt, which is slightly higher than many existing observations. Our observations indicate that enhanced BrO concentrations around Antarctica exist about one month earlier than observed by satellite instruments. From detailed radiative transfer simulations we find that MAX-DOAS observations are up to about one order of

  16. SU-D-18A-02: Towards Real-Time On-Board Volumetric Image Reconstruction for Intrafraction Target Verification in Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Xu, X; Iliopoulos, A; Zhang, Y; Pitsianis, N; Sun, X; Yin, F; Ren, L [Duke University, Durham, NC (United States)

    2014-06-01

    Purpose: To expedite on-board volumetric image reconstruction from limited-angle kV—MV projections for intrafraction verification. Methods: A limited-angle intrafraction verification (LIVE) system has recently been developed for real-time volumetric verification of moving targets, using limited-angle kV—MV projections. Currently, it is challenged by the intensive computational load of the prior-knowledge-based reconstruction method. To accelerate LIVE, we restructure the software pipeline to make it adaptable to model and algorithm parameter changes, while enabling efficient utilization of rapidly advancing, modern computer architectures. In particular, an innovative two-level parallelization scheme has been designed: At the macroscopic level, data and operations are adaptively partitioned, taking into account algorithmic parameters and the processing capacity or constraints of underlying hardware. The control and data flows of the pipeline are scheduled in such a way as to maximize operation concurrency and minimize total processing time. At the microscopic level, the partitioned functions act as independent modules, operating on data partitions in parallel. Each module is pre-parallelized and optimized for multi-core processors (CPUs) and graphics processing units (GPUs). Results: We present results from a parallel prototype, where most of the controls and module parallelization are carried out via Matlab and its Parallel Computing Toolbox. The reconstruction is 5 times faster on a data-set of twice the size, compared to recently reported results, without compromising on algorithmic optimization control. Conclusion: The prototype implementation and its results have served to assess the efficacy of our system concept. While a production implementation will yield much higher processing rates by approaching full-capacity utilization of CPUs and GPUs, some mutual constraints between algorithmic flow and architecture specifics remain. Based on a careful analysis

  17. SU-F-I-73: Surface Dose from KV Diagnostic Beams From An On-Board Imager On a Linac Machine Using Different Imaging Techniques and Filters

    Energy Technology Data Exchange (ETDEWEB)

    Ali, I; Hossain, S; Syzek, E; Ahmad, S [University of Oklahoma Health Sciences Center, Department of Radiation Oncology, Oklahoma City, OK (United States)

    2016-06-15

    Purpose: To quantitatively investigate the surface dose deposited in patients imaged with a kV on-board-imager mounted on a radiotherapy machine using different clinical imaging techniques and filters. Methods: A high sensitivity photon diode is used to measure the surface dose on central-axis and at an off-axis-point which is mounted on the top of a phantom setup. The dose is measured for different imaging techniques that include: AP-Pelvis, AP-Head, AP-Abdomen, AP-Thorax, and Extremity. The dose measurements from these imaging techniques are combined with various filtering techniques that include: no-filter (open-field), half-fan bowtie (HF), full-fan bowtie (FF) and Cu-plate filters. The relative surface dose for different imaging and filtering techniques is evaluated quantiatively by the ratio of the dose relative to the Cu-plate filter. Results: The lowest surface dose is deposited with the Cu-plate filter. The highest surface dose deposited results from open fields without filter and it is nearly a factor of 8–30 larger than the corresponding imaging technique with the Cu-plate filter. The AP-Abdomen technique delivers the largest surface dose that is nearly 2.7 times larger than the AP-Head technique. The smallest surface dose is obtained from the Extremity imaging technique. Imaging with bowtie filters decreases the surface dose by nearly 33% in comparison with the open field. The surface doses deposited with the HF or FF-bowtie filters are within few percentages. Image-quality of the radiographic images obtained from the different filtering techniques is similar because the Cu-plate eliminates low-energy photons. The HF- and FF-bowtie filters generate intensity-gradients in the radiographs which affects image-quality in the different imaging technique. Conclusion: Surface dose from kV-imaging decreases significantly with the Cu-plate and bowtie-filters compared to imaging without filters using open-field beams. The use of Cu-plate filter does not affect

  18. Evaluating real-world CO2 and NOX emissions for public transit buses using a remote wireless on-board diagnostic (OBD) approach.

    Science.gov (United States)

    Yang, Liuhanzi; Zhang, Shaojun; Wu, Ye; Chen, Qizheng; Niu, Tianlin; Huang, Xu; Zhang, Shida; Zhang, Liangjun; Zhou, Yu; Hao, Jiming

    2016-11-01

    The challenge to mitigate real-world emissions from vehicles calls for powerful in-use compliance supervision. The remote on-board diagnostic (OBD) approach, with wireless data communications, is one of the promising next-generation monitoring methods. We collected second-by-second profiles of carbon dioxide (CO2) and nitrogen oxides (NOX) emissions, driving conditions and engine performance for three conventional diesel and three hybrid diesel buses participating in a remote OBD pilot program in Nanjing, China. Our results showed that the average CO2 emissions for conventional diesel and hybrid diesel buses were 816 ± 83 g km(-1) and 627 ± 54 g km(-1), respectively, under a typical driving pattern. An operating mode binning analysis indicated that CO2 emissions reduction by series-parallel hybrid technology was largely because of the significant benefits of the technology under the modes of low speed and low power demand. However, significantly higher CO2 emissions were observed for conventional diesel buses during rush hours, higher than 1200 g km(-1). The OBD data suggested no improvement in NOX emission reduction for hybrid buses compared with conventional buses; both were approximately 12 g km(-1) because of poor performance of the selective catalyst reduction (SCR) systems in the real world. Speed-dependent functions for real-world CO2 and NOX emissions were also constructed. The CO2 emissions of hybrid buses were much less sensitive to the average speed than conventional buses. If the average speed decreased from 20 km h(-1) to 10 km h(-1), the estimated CO2 emission factor for conventional buses would be increased by 34%. Such a change in speed would increase NOX emissions for conventional and hybrid buses by 38% and 56%, respectively. This paper demonstrates the useful features of the remote OBD system and can inform policy makers how to take advantage of these features in monitoring in-use vehicles. Copyright © 2016 Elsevier Ltd. All

  19. SU-C-18A-05: Registration Accuracy of MR-Based Images to On-Board Megavoltage Cone-Beam CT for Brain Patient Setup

    Energy Technology Data Exchange (ETDEWEB)

    Pinnaduwage, D S; Chen, J; Descovich, M; Pouliot, J [Department of Radiation Oncology, University of California San Francisco, San Francisco, CA (United States); Hwang, Ken-Ping [Global MR Applications and Workflow, GE Healthcare, Houston, TX (United States); Department of Imaging Physics, The University of Texas M.D. Anderson Cancer Center, Houston, TX (United States)

    2014-06-01

    Purpose: To quantify the difference in isocenter shifts when co-registering MR and MR-based pseudo CTs (pCT) with on-board megavoltage conebeam CT (CBCT) images. Methods: Fast Spoiled Gradient Echo MRs were used to generate pCTs (research version of Advantage Sim MD™, GE Healthcare) for ten patients who had prior brain radiotherapy. The planning CT (rCT) for each was co-registered with the MR, and the plan isocenter and two other reference points were transferred to the MR and pCT. CBCT images (with the machine isocenter) from a single treatment day were coregistered with the 3 test images (MR, pCT and rCT), by two observers and by an automated registration algorithm. The reference points were used to calculate patient shifts and rotations from the registrations. The shifts calculated from the test image registrations were compared to each other and to the shifts performed by the therapists who treated the patients on that day. Results: The average difference in absolute value between the isocenter shifts from the MR-, pCT- and rCT-CBCT registrations, and the therapist shifts, were 2.02, 3.01 and 0.89 mm (craniocaudal), 1.14, 1.34 and 0.46 mm (lateral), and 1.37, 3.43 and 1.43 mm (vertical), respectively. The MR- and pCT-CBCT registrations differed by 1.99, and 2.53 mm (craniocaudal), 1.36, and 1.37 mm (lateral), and 0.74 and 2.34 mm (vertical), respectively, from the average rCT-CBCT shifts. On average, differences of 2.39 (craniocaudal), 1.28 (lateral) and 2.84 mm (vertical) were seen between the MR and pCT shifts. Rotations relative to the CBCT coordinate system were on average <2° for the MR and rCT, and <6° for the pCT. Conclusion: In this study, FSPGR MR-CBCT registrations were more precise compared to the pCT-CBCT registrations. For improved accuracy, MR sequences that are optimal for bony anatomy visualization are necessary. GE healthcare has provided a research version of Advantage Sim MD to UCSF. No financial support was provided.

  20. Receiver Design, Performance Analysis, and Evaluation for Space-Borne Laser Altimeters and Space-to-Space Laser Ranging Systems

    Science.gov (United States)

    Davidson, Frederic M.; Sun, Xiaoli; Field, Christopher T.

    1996-01-01

    This progress report consists of two separate reports. The first one describes our work on the use of variable gain amplifiers to increase the receiver dynamic range of space borne laser altimeters such as NASA's Geoscience Laser Altimeter Systems (GLAS). The requirement of the receiver dynamic range was first calculated. A breadboard variable gain amplifier circuit was made and the performance was fully characterized. The circuit will also be tested in flight on board the Shuttle Laser Altimeter (SLA-02) next year. The second report describes our research on the master clock oscillator frequency calibration for space borne laser altimeter systems using global positioning system (GPS) receivers.

  1. Range Resolved CO2 Atmospheric Backscattering Measurements Using Fiber Lasers and RZPN Code Modulation

    Science.gov (United States)

    Burris, John

    2011-01-01

    We report the use of a return-to- zero (RZPN) pseudo noise modulation technique for making range resolved measurements of CO2 within the planetary boundary layer (PBL) using commercial, off-the-shelf, components. Conventional, range resolved, DIAL measurements require laser pulse widths that are significantly shorter than the desired spatial resolution and necessitate using pulses whose temporal spacing is such that scattered returns from only a single pulse are observed by the receiver at any one time (for the PBL pulse separations must be greater than approximately 20 microseconds). This imposes significant operational limitations when using currently available fiber lasers because of the resulting low duty cycle (less than approximately 0.0005) and consequent low average laser output power. The RZPN modulation technique enables a fiber laser to operate at much higher duty cycles (approaching 0.04) thereby more effectively utilizing the amplifier's output. This increases the counts received by approximately two orders of magnitude. Our approach involves employing two distributed feedback lasers (DFB), each modulated by a different RPZN code, whose outputs are then amplified by a CW fiber amplifier. One laser is tuned to a CO2 absorption line; the other operates offline thereby permitting the simultaneous acquisition of both on and offline signals using independent RZPN codes. This minimizes the impact of atmospheric turbulence on the measurement. The on and offline signals are retrieved by deconvolving the return signal using the appropriate kernels.

  2. DREAMS: a payload on-board the ExoMars EDM Schiaparelli for the characterization of Martian environment during the statistical dust storm season

    Science.gov (United States)

    Molfese, Cesare; Esposito, Francesca; Debei, Stefano; Bettanini, Carlo; Arruego Rodríguez, Ignacio; Colombatti, Giacomo; Harri, Ari-Matty.; Montmessin, Franck; Wilson, Colin; Aboudan, Alessio; Mugnuolo, Raffaele; Pirrotta, Simone; Marchetti, Ernesto; Witasse, Olivier

    2015-04-01

    , the dust opacity, and the atmospheric electric properties close to the surface of Mars. It will fly in January 2016 on-board the Schiaparelli Entry, Descent and landing Demonstrator Module (EDM) of the ExoMars space mission. It is foreseen to land on Mars in late October 2016 during the statistical dust storm season. Therefore, DREAMS might have the unique chance to make scientific measurements to characterize the Martian environment in a dusty scenario also performing the first ever measurements of atmospheric electric field on Mars. The relationship between the process of dust entrainment in the atmosphere during dust events and the enhancement of atmospheric electric field has been widely studied in an intense field test campaign in the Sahara desert. In order to better characterize this physical process, we performed atmospheric and environmental measurements comparable to those that DREAMS will acquire on Mars. Preliminary results will be discussed. DREAMS is in a high development state. A first model has been delivered to ESA and has been integrated in the EDM Flight Model. Integration tests are on-going. The DREAMS Flight Model will be delivered at the end of March this year.

  3. UAV sensor systems for close-range operations

    Science.gov (United States)

    Larroque, Clement-Serge; Thompson, Karl S.; Hickman, Duncan

    2002-07-01

    Although UAV systems have received much interest over the last few years, much of this has focused on either relatively large platforms with complex on-board equipment, or micro systems (typically 6' in every dimension). The operational use of low-cost lightweight UAVs as over-the- hill reconnaissance systems is a new concept offering additional flexibility, providing local knowledge and helping maintain operational tempo. An extensive modeling trade-off study has been performed for different sensor technologies and combinations. The model considered configurations including cooled and uncooled IR sensors, visible-band CCD sensors and image intensifiers. These mathematical models provide an evaluation of sensor performance for both navigation and the gathering of reconnaissance imagery, through Resolution Elements calculations (Johnson criteria) and Signal-to-Noise Ratios. Based upon this analysis, a system specification is presented that exploits next generation sensor technologies. Results obtained from a number of UAV trials are reported and used in order to provide model verification and validation of both the operational concepts and the sensor system modeling activities. Considering the sensor system itself, the low-altitude close-range environment ensures high ground resolved distance and signal-to-noise ratios, with low-cost sensors. Coupled with up-to-date image processing software, the imagery provided directly to the section-level units via a simple standard image interface allows a reduction of time response. Finally, future modeling and trials activities are discussed in the framework of the lightweight UAV system roadmap.

  4. An Observability Metric for Underwater Vehicle Localization Using Range Measurements

    Science.gov (United States)

    Arrichiello, Filippo; Antonelli, Gianluca; Aguiar, Antonio Pedro; Pascoal, Antonio

    2013-01-01

    The paper addresses observability issues related to the general problem of single and multiple Autonomous Underwater Vehicle (AUV) localization using only range measurements. While an AUV is submerged, localization devices, such as Global Navigation Satellite Systems, are ineffective, due to the attenuation of electromagnetic waves. AUV localization based on dead reckoning techniques and the use of affordable motion sensor units is also not practical, due to divergence caused by sensor bias and drift. For these reasons, localization systems often build on trilateration algorithms that rely on the measurements of the ranges between an AUV and a set of fixed transponders using acoustic devices. Still, such solutions are often expensive, require cumbersome calibration procedures and only allow for AUV localization in an area that is defined by the geometrical arrangement of the transponders. A viable alternative for AUV localization that has recently come to the fore exploits the use of complementary information on the distance from the AUV to a single transponder, together with information provided by on-board resident motion sensors, such as, for example, depth, velocity and acceleration measurements. This concept can be extended to address the problem of relative localization between two AUVs equipped with acoustic sensors for inter-vehicle range measurements. Motivated by these developments, in this paper, we show that both the problems of absolute localization of a single vehicle and the relative localization of multiple vehicles can be treated using the same mathematical framework, and tailoring concepts of observability derived for nonlinear systems, we analyze how the performance in localization depends on the types of motion imparted to the AUVs. For this effect, we propose a well-defined observability metric and validate its usefulness, both in simulation and by carrying out experimental tests with a real marine vehicle during which the performance of an

  5. An Observability Metric for Underwater Vehicle Localization Using Range Measurements

    Directory of Open Access Journals (Sweden)

    Filippo Arrichiello

    2013-11-01

    Full Text Available The paper addresses observability issues related to the general problem of single and multiple Autonomous Underwater Vehicle (AUV localization using only range measurements. While an AUV is submerged, localization devices, such as Global Navigation Satellite Systems, are ineffective, due to the attenuation of electromagnetic waves. AUV localization based on dead reckoning techniques and the use of affordable motion sensor units is also not practical, due to divergence caused by sensor bias and drift. For these reasons, localization systems often build on trilateration algorithms that rely on the measurements of the ranges between an AUV and a set of fixed transponders using acoustic devices. Still, such solutions are often expensive, require cumbersome calibration procedures and only allow for AUV localization in an area that is defined by the geometrical arrangement of the transponders. A viable alternative for AUV localization that has recently come to the fore exploits the use of complementary information on the distance from the AUV to a single transponder, together with information provided by on-board resident motion sensors, such as, for example, depth, velocity and acceleration measurements. This concept can be extended to address the problem of relative localization between two AUVs equipped with acoustic sensors for inter-vehicle range measurements. Motivated by these developments, in this paper, we show that both the problems of absolute localization of a single vehicle and the relative localization of multiple vehicles can be treated using the same mathematical framework, and tailoring concepts of observability derived for nonlinear systems, we analyze how the performance in localization depends on the types of motion imparted to the AUVs. For this effect, we propose a well-defined observability metric and validate its usefulness, both in simulation and by carrying out experimental tests with a real marine vehicle during which the

  6. Survey on Ranging Sensors and Cooperative Techniques for Relative Positioning of Vehicles

    Directory of Open Access Journals (Sweden)

    Fabian de Ponte Müller

    2017-01-01

    Full Text Available Future driver assistance systems will rely on accurate, reliable and continuous knowledge on the position of other road participants, including pedestrians, bicycles and other vehicles. The usual approach to tackle this requirement is to use on-board ranging sensors inside the vehicle. Radar, laser scanners or vision-based systems are able to detect objects in their line-of-sight. In contrast to these non-cooperative ranging sensors, cooperative approaches follow a strategy in which other road participants actively support the estimation of the relative position. The limitations of on-board ranging sensors regarding their detection range and angle of view and the facility of blockage can be approached by using a cooperative approach based on vehicle-to-vehicle communication. The fusion of both, cooperative and non-cooperative strategies, seems to offer the largest benefits regarding accuracy, availability and robustness. This survey offers the reader a comprehensive review on different techniques for vehicle relative positioning. The reader will learn the important performance indicators when it comes to relative positioning of vehicles, the different technologies that are both commercially available and currently under research, their expected performance and their intrinsic limitations. Moreover, the latest research in the area of vision-based systems for vehicle detection, as well as the latest work on GNSS-based vehicle localization and vehicular communication for relative positioning of vehicles, are reviewed. The survey also includes the research work on the fusion of cooperative and non-cooperative approaches to increase the reliability and the availability.

  7. Survey on Ranging Sensors and Cooperative Techniques for Relative Positioning of Vehicles.

    Science.gov (United States)

    de Ponte Müller, Fabian

    2017-01-31

    Future driver assistance systems will rely on accurate, reliable and continuous knowledge on the position of other road participants, including pedestrians, bicycles and other vehicles. The usual approach to tackle this requirement is to use on-board ranging sensors inside the vehicle. Radar, laser scanners or vision-based systems are able to detect objects in their line-of-sight. In contrast to these non-cooperative ranging sensors, cooperative approaches follow a strategy in which other road participants actively support the estimation of the relative position. The limitations of on-board ranging sensors regarding their detection range and angle of view and the facility of blockage can be approached by using a cooperative approach based on vehicle-to-vehicle communication. The fusion of both, cooperative and non-cooperative strategies, seems to offer the largest benefits regarding accuracy, availability and robustness. This survey offers the reader a comprehensive review on different techniques for vehicle relative positioning. The reader will learn the important performance indicators when it comes to relative positioning of vehicles, the different technologies that are both commercially available and currently under research, their expected performance and their intrinsic limitations. Moreover, the latest research in the area of vision-based systems for vehicle detection, as well as the latest work on GNSS-based vehicle localization and vehicular communication for relative positioning of vehicles, are reviewed. The survey also includes the research work on the fusion of cooperative and non-cooperative approaches to increase the reliability and the availability.

  8. Study of the application of hydrogen fuel to long-range subsonic transport aircraft. Volume 1: Summary

    Science.gov (United States)

    Brewer, G. D.; Morris, R. E.; Lange, R. H.; Moore, J. W.

    1975-01-01

    The feasibility of using liquid hydrogen as fuel in advanced designs of long range, subsonic transport aircraft is assessed. Both passenger and cargo type aircraft are investigated. Comparisons of physical, performance, and economic parameters of the LH2 fueled designs with conventionally fueled aircraft are presented. Design studies are conducted to determine appropriate characteristics for the hydrogen related systems required on board the aircraft. These studies included consideration of material, structural, and thermodynamic requirements of the cryogenic fuel tanks and fuel systems with the structural support and thermal protection systems.

  9. Ranging Behaviour of Commercial Free-Range Laying Hens

    Directory of Open Access Journals (Sweden)

    Leonard Ikenna Chielo

    2016-04-01

    Full Text Available In this study, the range use and behaviour of laying hens in commercial free-range flocks was explored. Six flocks were each visited on four separate days and data collected from their outdoor area (divided into zones based on distance from shed and available resources. These were: apron (0–10 m from shed normally without cover or other enrichments; enriched belt (10–50 m from shed where resources such as manmade cover, saplings and dust baths were provided; and outer range (beyond 50 m from shed with no cover and mainly grass pasture. Data collection consisted of counting the number of hens in each zone and recording behaviour, feather condition and nearest neighbour distance (NND of 20 birds per zone on each visit day. In addition, we used techniques derived from ecological surveys to establish four transects perpendicular to the shed, running through the apron, enriched belt and outer range. Number of hens in each 10 m × 10 m quadrat was recorded four times per day as was the temperature and relative humidity of the outer range. On average, 12.5% of hens were found outside. Of these, 5.4% were found in the apron; 4.3% in the enriched zone; and 2.8% were in the outer range. This pattern was supported by data from quadrats, where the density of hens sharply dropped with increasing distance from shed. Consequently, NND was greatest in the outer range, least in the apron and intermediate in the enriched belt. Hens sampled in outer range and enriched belts had better feather condition than those from the apron. Standing, ground pecking, walking and foraging were the most commonly recorded activities with standing and pecking most likely to occur in the apron, and walking and foraging more common in the outer range. Use of the outer range declined with lower temperatures and increasing relative humidity, though use of apron and enriched belt was not affected by variation in these measures. These data support previous findings that outer range

  10. Ranging Behaviour of Commercial Free-Range Laying Hens.

    Science.gov (United States)

    Chielo, Leonard Ikenna; Pike, Tom; Cooper, Jonathan

    2016-04-26

    In this study, the range use and behaviour of laying hens in commercial free-range flocks was explored. Six flocks were each visited on four separate days and data collected from their outdoor area (divided into zones based on distance from shed and available resources). These were: apron (0-10 m from shed normally without cover or other enrichments); enriched belt (10-50 m from shed where resources such as manmade cover, saplings and dust baths were provided); and outer range (beyond 50 m from shed with no cover and mainly grass pasture). Data collection consisted of counting the number of hens in each zone and recording behaviour, feather condition and nearest neighbour distance (NND) of 20 birds per zone on each visit day. In addition, we used techniques derived from ecological surveys to establish four transects perpendicular to the shed, running through the apron, enriched belt and outer range. Number of hens in each 10 m × 10 m quadrat was recorded four times per day as was the temperature and relative humidity of the outer range. On average, 12.5% of hens were found outside. Of these, 5.4% were found in the apron; 4.3% in the enriched zone; and 2.8% were in the outer range. This pattern was supported by data from quadrats, where the density of hens sharply dropped with increasing distance from shed. Consequently, NND was greatest in the outer range, least in the apron and intermediate in the enriched belt. Hens sampled in outer range and enriched belts had better feather condition than those from the apron. Standing, ground pecking, walking and foraging were the most commonly recorded activities with standing and pecking most likely to occur in the apron, and walking and foraging more common in the outer range. Use of the outer range declined with lower temperatures and increasing relative humidity, though use of apron and enriched belt was not affected by variation in these measures. These data support previous findings that outer range areas tend to be

  11. Osprey Range - CWHR [ds601

    Data.gov (United States)

    California Department of Resources — Vector datasets of CWHR range maps are one component of California Wildlife Habitat Relationships (CWHR), a comprehensive information system and predictive model for...

  12. Short-range fundamental forces

    CERN Document Server

    Antoniadis, I; Buchner, M; Fedorov, V V; Hoedl, S; Lambrecht, A; Nesvizhevsky, V V; Pignol, G; Protasov, K V; Reynaud, S; Sobolev, Yu

    2011-01-01

    We consider theoretical motivations to search for extra short-range fundamental forces as well as experiments constraining their parameters. The forces could be of two types: 1) spin-independent forces, 2) spin-dependent axion-like forces. Differe nt experimental techniques are sensitive in respective ranges of characteristic distances. The techniques include measurements of gravity at short distances, searches for extra interactions on top of the Casimir force, precision atomic and neutron experim ents. We focus on neutron constraints, thus the range of characteristic distances considered here corresponds to the range accessible for neutron experiments.

  13. Cascade Mountain Range in Oregon

    Science.gov (United States)

    Sherrod, David R.

    2016-01-01

    The Cascade mountain system extends from northern California to central British Columbia. In Oregon, it comprises the Cascade Range, which is 260 miles long and, at greatest breadth, 90 miles wide (fig. 1). Oregon’s Cascade Range covers roughly 17,000 square miles, or about 17 percent of the state, an area larger than each of the smallest nine of the fifty United States. The range is bounded on the east by U.S. Highways 97 and 197. On the west it reaches nearly to Interstate 5, forming the eastern margin of the Willamette Valley and, farther south, abutting the Coast Ranges

  14. Ranging Behaviour of Commercial Free-Range Laying Hens

    Science.gov (United States)

    Chielo, Leonard Ikenna; Pike, Tom; Cooper, Jonathan

    2016-01-01

    Simple Summary Commercial free-range production has become a significant sector of the fresh egg market due to legislation banning conventional cages and consumer preference for products perceived as welfare friendly, as access to outdoor range can lead to welfare benefits such as greater freedom of movement and enhanced behavioural opportunities. This study investigated dispersal patterns, feather condition and activity of laying hens in three distinct zones of the range area; the apron area near shed; enriched zone 10–50 m from shed; and outer range beyond 50 m, in six flocks of laying hens under commercial free-range conditions varying in size between 4000 and 24,000 hens. Each flock was visited for four days to record number of hens in each zone, their behaviour, feather condition and nearest neighbour distances (NND), as well as record temperature and relative humidity during the visit. Temperature and relative humidity varied across the study period in line with seasonal variations and influenced the use of range with fewer hens out of shed as temperature fell or relative humidity rose. On average, 12.5% of the hens were observed on the range and most of these hens were recorded in the apron zone as hen density decreased rapidly with increasing distance from the shed. Larger flocks appeared to have a lower proportion of hens on range. The hens used the range more in the early morning followed by a progressive decrease through to early afternoon. The NND was greatest in the outer range and decreased towards the shed. Feather condition was generally good and hens observed in the outer range had the best overall feather condition. Standing, pecking, walking and foraging were the most commonly recorded behaviours and of these, standing occurred most in the apron whereas walking and foraging behaviours were recorded most in the outer range. This study supported the findings of previous studies that reported few hens in the range and greater use of areas closer

  15. Desert Experimental Range: Annotated bibliography

    Science.gov (United States)

    E. Durant McArthur; Stanley G. Kitchen

    2013-01-01

    Entries qualify for inclusion if they were conducted in whole or part at the Desert Experimental Range (DER, also known as the Desert Range Experiment Station) or were based on DER research in whole or part. They do not qualify merely by the author having worked at the DER when the research was performed or prepared. Entries were drawn from the original abstracts or...

  16. Physical processes in the vicinity of the cometopause interpreted on the basis of plasma, magnetic field, and plasma wave data measured on board the Vega 2 spacecraft

    Energy Technology Data Exchange (ETDEWEB)

    Galeev, A.A.; Gringauz, K.I.; Klimov, S.I.; Remizov, A.P.; Sagdeev, R.Z.; Savin, S.P.; Sokolov, A.Y.; Verigin, M.I. (Space Research Inst., Moscow (USSR)); Szegoe, K.; Tatrallyay, M. (Central Research Inst. for Physics, Budapest (Hungary)); Grard, R. (European Space Agency, Noordwijk (The Netherlands)); Yeroshenko, Ye.G.; Mogilevsky, M. (Izmiran, Troitsk (USSR)); Riedler, W.; Schwingenschuh, K. (Space Research Inst., Graz (Austria))

    1988-07-01

    This paper presents the first step toward a comprehensive interpretation of the plasma, electric, and magnetic field measurements performed by four different instruments near the cometopause of Halley's comet. No flow parameter displays any drastic variation at this boundary which separates two environments with different chemical composition. A fire hose instability is possibly developing near the cometopause where the number of cometary ions significantly increases. The waves at the lower hybrid frequency and in the whistler range have similar amplitudes.

  17. Foraging optimally for home ranges

    Science.gov (United States)

    Mitchell, Michael S.; Powell, Roger A.

    2012-01-01

    Economic models predict behavior of animals based on the presumption that natural selection has shaped behaviors important to an animal's fitness to maximize benefits over costs. Economic analyses have shown that territories of animals are structured by trade-offs between benefits gained from resources and costs of defending them. Intuitively, home ranges should be similarly structured, but trade-offs are difficult to assess because there are no costs of defense, thus economic models of home-range behavior are rare. We present economic models that predict how home ranges can be efficient with respect to spatially distributed resources, discounted for travel costs, under 2 strategies of optimization, resource maximization and area minimization. We show how constraints such as competitors can influence structure of homes ranges through resource depression, ultimately structuring density of animals within a population and their distribution on a landscape. We present simulations based on these models to show how they can be generally predictive of home-range behavior and the mechanisms that structure the spatial distribution of animals. We also show how contiguous home ranges estimated statistically from location data can be misleading for animals that optimize home ranges on landscapes with patchily distributed resources. We conclude with a summary of how we applied our models to nonterritorial black bears (Ursus americanus) living in the mountains of North Carolina, where we found their home ranges were best predicted by an area-minimization strategy constrained by intraspecific competition within a social hierarchy. Economic models can provide strong inference about home-range behavior and the resources that structure home ranges by offering falsifiable, a priori hypotheses that can be tested with field observations.

  18. Reference Ranges & What They Mean

    Science.gov (United States)

    ... Chains Sex Hormone Binding Globulin (SHBG) Shiga toxin-producing Escherichia coli Sickle Cell Tests Sirolimus Smooth Muscle ... If you're trying to follow a healthy lifestyle, take test results that are within range as ...

  19. Kenai National Moose Range Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This book presents a summary of the history, wildlife, recreational opportunities, economic uses, and future plans for Kenai National Moose Range.

  20. On-board measurement of particle numbers and their size distribution from a light-duty diesel vehicle: Influences of VSP and altitude.

    Science.gov (United States)

    Liu, Jia; Ge, Yunshan; Wang, Xin; Hao, Lijun; Tan, Jianwei; Peng, Zihang; Zhang, Chuanzhen; Gong, Huiming; Huang, Ying

    2017-07-01

    In this study, the particle size-resolved distribution from a China-3 certificated light-duty diesel vehicle was measured by using a portable emission measurement system (PEMS). In order to examine the influences of vehicle specific power (VSP) and high-altitude operation, measurements were conducted at 8 constant speeds, which ranged from 10 to 80km/hr at 10km/hr intervals, and two different high altitudes, namely 2200 and 3200m. The results demonstrated that the numbers of particles in all size ranges decreased significantly as VSP increased when the test vehicle was running at lower speeds (particle number was statistically insensitive to increase VSP. Under high-speed cruising conditions, the numbers of ultrafine particles and PM2.5 were insensitive to changes in VSP, but the numbers of nanoparticles and PM10 surged considerably. An increase in the operational altitude of the test vehicle resulted in increased particle number emissions at low and high driving speeds; however, particle numbers obtained at moderate speeds decreased as altitude rose. When the test vehicle was running at moderate speeds, particle numbers measured at the two altitudes were very close, except for comparatively higher number concentrations of nanoparticles measured at 2200m. Copyright © 2017. Published by Elsevier B.V.

  1. On-board telemetry of emitted sounds from free-flying bats: compensation for velocity and distance stabilizes echo frequency and amplitude.

    Science.gov (United States)

    Hiryu, Shizuko; Shiori, Yu; Hosokawa, Tatsuro; Riquimaroux, Hiroshi; Watanabe, Yoshiaki

    2008-09-01

    To understand complex sensory-motor behavior related to object perception by echolocating bats, precise measurements are needed for echoes that bats actually listen to during flight. Recordings of echolocation broadcasts were made from flying bats with a miniature light-weight microphone and radio transmitter (Telemike) set at the position of the bat's ears and carried during flights to a landing point on a wall. Telemike recordings confirm that flying horseshoe bats (Rhinolophus ferrumequinum nippon) adjust the frequency of their sonar broadcasts to compensate for echo Doppler shifts. Returning constant frequency echoes were maintained at the bat's reference frequency +/-83 Hz during flight, indicating that the bats compensated for frequency changes with an accuracy equivalent to that at rest. The flying bats simultaneously compensate for increases in echo amplitude as target range becomes shorter. Flying bats thus receive echoes with both stabilized frequencies and stabilized amplitudes. Although it is widely understood that Doppler-shift frequency compensation facilitates detection of fluttering insects, approaches to a landing do not involve fluttering objects. Combined frequency and amplitude compensation may instead be for optimization of successive frequency modulated echoes for target range estimation to control approach and landing.

  2. Contribution to the study of the dynamic behaviour of a on-board rotor; Contribution a l'etude du comportement dynamique d'un rotor embarque

    Energy Technology Data Exchange (ETDEWEB)

    Duchemin, M.

    2003-12-15

    The aim of this work was the development of a model allowing to simulate the dynamical behaviour on an on-board rotor. The calculations of the different energies and virtual works of the different parts of a rotor submitted to a random movement have been made taking into account the different possible asymmetries of the shaft and of the discs. A simple model has been defined using the Rayleigh-Ritz method in order to study the basic phenomena. For the processing of real systems, a finite-element modeling has been developed. The nonlinear equations of the movement have been obtained using the application of Lagrange equations. The basic phenomena relative to the rotors dynamics with a moving stand have been studied for the simple model. Various analytical studies have been performed on simple movements: simple translation, sinusoidal translation, constant rotation, accelerated rotation. For all these movements, the deformation equations remain linear. On the contrary, for a simple sinusoidal rotation movement, parametric terms have to be entered in the equations. An instability study has been performed on this movement using the multiple scales method. This method has permitted to determine the instability areas. A step-by-step resolution has been used to check these instability areas with the Rayleigh-Ritz model. An experimental device has been made to test the model developed with the finite-element method. The main movement analyzed is the sinusoidal rotation one which seems to be the most interesting with respect to the phenomena described with the simple model. The adjustment of the resonance frequencies of the system has been performed by the adjustment of the bearings stiffness. The study of an on-board rotor with a flexible stand is thus not a priority. The adjustment of the damping performed on an angular shock study has shown that the obtained modeling is very good when the structural damping is distributed over the bearings. After adjustment, the

  3. Dust Impact Monitor (SESAME-DIM) on board Rosetta/Philae: Millimetric particle flux at comet 67P/Churyumov-Gerasimenko

    Science.gov (United States)

    Hirn, Attila; Albin, Thomas; Apáthy, István; Della Corte, Vincenzo; Fischer, Hans-Herbert; Flandes, Alberto; Loose, Alexander; Péter, Attila; Seidensticker, Klaus J.; Krüger, Harald

    2016-06-01

    Context. The Philae lander of the Rosetta mission, aimed at the in situ investigation of comet 67P/Churyumov-Gerasimenko, was deployed to the surface of the comet nucleus on 12 November 2014 at 2.99 AU heliocentric distance. The Dust Impact Monitor (DIM) as part of the Surface Electric Sounding and Acoustic Monitoring Experiment (SESAME) on the lander employed piezoelectric detectors to detect the submillimetre- and millimetre-sized dust and ice particles emitted from the nucleus. Aims: We determine the upper limit of the ambient flux of particles in the measurement range of DIM based on the measurements performed with the instrument during Philae's descent to its nominal landing site Agilkia at distances of about 22 km, 18 km, and 5 km from the nucleus barycentre and at the final landing site Abydos. Methods: The geometric factor of the DIM sensor was calculated assuming an isotropic ambient flux of the submillimetre- and millimetre-sized particles. For the measurement intervals when no particles were detected the maximum true impact rate was calculated by assuming Poisson distribution of the impacts, and it was given as the detection limit at a 95% confidence level. The shading by the comet environment at Abydos was estimated by simulating the pattern of illumination on Philae and consequently the topography around the lander. Results: Based on measurements performed with DIM, the upper limit of the flux of particles in the measurement range of the instrument was of the order of 10-8-10-7 m-2 s-1 sr-1 during descent. The upper limit of the ambient flux of the submillimetre- and millimetre-sized dust and ice particles at Abydos was estimated to be 1.6 × 10-9 m-2 s-1 sr-1 on 13 and 14 November 2014. A correction factor of roughly 1/3 for the field of view of the sensors was calculated based on an analysis of the pattern of illumination on Philae. Conclusions: Considering particle speeds below escape velocity, the upper limit for the volume density of particles in

  4. Wide Operational Range Thermal Sensor

    Science.gov (United States)

    Goebel, John H. (Inventor); McMurray, Robert E., Jr. (Inventor)

    2005-01-01

    Bolometer system and method for detecting, at BLIP levels, presence of radiation over a broad range of wavelengths in an infrared spectrum and in a temperature range from 20 K to as high as room temperature. The radiation is received by a Si crystal having a region that is doped with one or more of In, Ga, S, Se, Te, B, Al, P, As and Sb in a concentration ratio in a range such as 5 x 10(exp -11) to 5 x 10(exp -6). Change in electrical resistance delta R due to receipt of the radiation is measured through a change in voltage difference or current within the crystal, and the quantity delta R is converted to an estimate of the amount of radiation received. Optionally, incident radiation having an energy high enough to promote photoconductivity is removed before detection.

  5. GEA CRDA Range Data Analysis

    Science.gov (United States)

    1999-07-28

    E1, July-August 1998 18 3.3. Example 3: SatMex, Solidaridad 2, May-June 1998 27 3.4. Example 4: PanAmSat, Galaxy IV, May-June 1998 33 3.5...17 Millstone measurements residuals for Telstar 401 on Days 181-263. 26 3-18 Millstone measurement residuals for Solidaridad 1 on Days 141-153...with 29 SatMex range data. 3-19 Hermosillo B-- Solidaridad 1 range residuals through Days 135-144 with bias 30 removed. 3-20 Iztapalapa D

  6. Radio pill antenna range test

    Science.gov (United States)

    Cummins, W. F.; Kane, R. J.

    1992-05-01

    In order to investigate the potential of a proposed 'radio pill' beacon transmitter, a range test experiment was devised and carried out in the VHF frequency range. Calculations and previous work indicated that optimum sensitivity and, thus, distance would be obtained in this frequency range provided body radio-frequency (RF) absorption was not too great. A ferrite-core loop antenna is compatible with a pill geometry and has better radiation efficiency than an air core loop. The ferrite core may be a hollow cylinder with the electronics and batteries placed inside. However, this range test was only concerned with experimentally developing test range data on the ferrite core antenna itself. A one turn strap loop was placed around a 9.5 mm diameter by 18.3 mm long stack of ferrite cores. This was coupled to a 50 Omega transmission line by 76 mm of twisted pair line and a capacitive matching section. This assembly was excited by a signal generator at output levels of -10 to +10 dBm. Signals were received on a VHF receiver and tape recorder coupled to a 14 element, circularly polarized Yagi antenna at a height of 2.5 m. Field strength measurements taken at ranges of 440, 1100, and 1714 m. Maximum field strengths referenced to 0 dBm transmitter level were -107 to -110 dB at 440 m, -124 to -127 dBm at 1100 m, and -116 to -119 dBm at 1714 m when the antenna cylinder was horizontal. Field strengths with a vertical antenna were about 6 dB below these values. The latter transmit site was elevated and had a clear line-of-site path to the receiving site. The performance of this test antenna was better than that expected from method-of-moment field calculations. When this performance data is scaled to a narrow bandwidth receiving system, ground level receiving ranges of a few to 10 km can be expected. Clear line-of-sight ranges where either or both the transmitter and receiver are elevated could vary from several km to 100 km.

  7. In situ CO2 and tracer observations in the 2015/16 Arctic UTLS with the new HAGAR-V instrument on board the HALO research aircraft

    Science.gov (United States)

    Volk, C. Michael; Wintel, Johannes; Lauther, Valentin; Gerhardt, Emil; vom Scheidt, Markus; Krause, Jens; Hoor, Peter

    2017-04-01

    During the POLSTRACC/GW-LCYCLE/SALSA (PGS) campaign the German High Altitude and LOng range research aircraft (HALO) intensively probed the bottom of the polar vortex and the adjacent mid to high latitude upper troposphere / lower stratosphere (UTLS) throughout the entire winter/spring during the extraordinarily cold Arctic winter 2015/16. A total of 18 science flights were performed from Oberpfaffenhofen, Germany, and Kiruna, Sweden, during three phases, in December 2015, early January to early February 2016, and late February to mid March 2016. During PGS, the University of Wuppertal deployed for the first time the High Altitude Gas Analyzer -V (HAGAR-V), a new 5-channel in-situ tracer instrument developed for HALO to study the chemical composition, dynamics, and transport in the UTLS. HAGAR-V combines i) a fast CO2 measurement by NDIR analyzer (every 1-3 s), ii) a 2-channel GC/ECD-system measuring long-lived tracers (during PGS: CH4, CFC-12, CFC-11 every 90s, SF6 every 30 s) and iii) a 2-channel GC/MS system targeting short-lived tracers (NMHCs and chlorinated hydrocarbons) with local lifetimes at the midlatitude tropopause ranging from several days to just under a year. The University of Mainz deployed the well-established TRIHOP instrument employing the TDL absorption technique to measure N2O, CH4, and CO every 10 s. We will give an overview of the new HAGAR-V instrument and present the measurements of CO2 and long-lived tracers, with a focus on the temporal development of vertical distributions and tracer correlations throughout the winter. In particular, an observed change of the correlation of CO2 with N2O between January and late February/March is likely caused by isentropic mixing in the high-latitude UTLS. We will also compare the tracer distributions during PGS with those observed from the M55 Geophysica aircraft during previous Arctic campaigns.

  8. Chemical characterization of individual particles and residuals of cloud droplets and ice crystals collected on board research aircraft in the ISDAC 2008 study

    Science.gov (United States)

    Hiranuma, N.; Brooks, S. D.; Moffet, R. C.; Glen, A.; Laskin, A.; Gilles, M. K.; Liu, P.; MacDonald, A. M.; Strapp, J. W.; McFarquhar, G. M.

    2013-06-01

    Ambient particles and the dry residuals of mixed-phase cloud droplets and ice crystals were collected during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) near Barrow, Alaska, in spring of 2008. The collected particles were analyzed using Computer Controlled Scanning Electron Microscopy with Energy Dispersive X-ray analysis and Scanning Transmission X-ray Microscopy coupled with Near Edge X-ray Absorption Fine Structure spectroscopy to identify physico-chemical properties that differentiate cloud-nucleating particles from the total aerosol population. A wide range of individually mixed components was identified in the ambient particles and residuals including organic carbon compounds, inorganics, carbonates, and black carbon. Our results show that cloud droplet residuals differ from the ambient particles in both size and composition, suggesting that both properties may impact the cloud-nucleating ability of aerosols in mixed-phase clouds. The percentage of residual particles which contained carbonates (47%) was almost four times higher than those in ambient samples. Residual populations were also enhanced in sea salt and black carbon and reduced in organic compounds relative to the ambient particles. Further, our measurements suggest that chemical processing of aerosols may improve their cloud-nucleating ability. Comparison of results for various time periods within ISDAC suggests that the number and composition of cloud-nucleating particles over Alaska can be influenced by episodic events bringing aerosols from both the local vicinity and as far away as Siberia.

  9. Improved Range Searching Lower Bounds

    DEFF Research Database (Denmark)

    Larsen, Kasper Green; Nguyen, Huy L.

    2012-01-01

    by constructing a hard input set and query set, and then invoking Chazelle and Rosenberg's [CGTA'96] general theorem on the complexity of navigation in the pointer machine. For the group model, we show that input sets and query sets that are hard for range reporting in the pointer machine (i.e. by Chazelle...

  10. Anatomy of a Mountain Range.

    Science.gov (United States)

    Chew, Berkeley

    1993-01-01

    Provides written tour of Colorado Rockies along San Juan Skyway in which the geological features and formation of the mountain range is explored. Discusses evidence of geologic forces and products such as plate tectonic movement and the Ancestral Rockies; subduction and the Laramide Orogeny; volcanism and calderas; erosion, faulting, land…

  11. Mobile Lunar Laser Ranging Station

    Science.gov (United States)

    Intellect, 1977

    1977-01-01

    Harlan Smith, chairman of the University of Texas's Astronomy Department, discusses a mobile lunar laser ranging station which could help determine the exact rates of movement between continents and help geophysicists understand earthquakes. He also discusses its application for studying fundamental concepts of cosmology and physics. (Editor/RK)

  12. Range Compressed Holographic Aperture Ladar

    Science.gov (United States)

    2017-06-01

    step 1. This image can be obtained through any digital holography processing technique and contains no range information. Since the penny has a... digital holography, laser, active imaging , remote sensing, laser imaging 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT: SAR 8...30 15. Digital Hologram Image

  13. Mandibular movement range in children.

    Science.gov (United States)

    Machado, Barbara Cristina Zanandréa; Medeiros, Ana Paula Magalhães; Felício, Cláudia Maria de

    2009-01-01

    identification of the mandibular movement range is an important procedure in the evaluation of the stomatognathic system. However, there are few studies in children that focus on normal parameters or abnormalities. to determine the average range of mandibular movements in Brazilian children aged 6 to 12 years; to verify the difference between genders, in each age group, and between the different age groups: 6-8 years; 8.1-10 years; and 10.1-12 years. participants of the study were 240 healthy children selected among regular students from local schools of São Paulo State. The maximum mandibular opening, lateral excursion and protrusive movements, and deviation of the medium line, if present, were measured using a digital caliper. Student T test, Analysis of variance and Tukey test were considered significant for p mandibular opening; 7.71mm for lateral excursion to the right; 7.92mm for lateral excursion to the left; 7.45mm for protrusive movements. No statistical difference was observed between genders. There was a gradual increase in the range of mandibular movements, with significant differences mainly between the ages of 6-8 years and 10.1-12 years. during childhood the range of mandibular movements increases. Age should be considered in this analysis for a greater precision in the diagnosis.

  14. Validation of water vapour profiles (version 13 retrieved by the IMK/IAA scientific retrieval processor based on full resolution spectra measured by MIPAS on board Envisat

    Directory of Open Access Journals (Sweden)

    M. Milz

    2009-07-01

    errors due to uncertainties in spectrally interfering species and where good coincidences were found, the χ2 values found are in the expected range or even below. This suggests that there is no evidence of systematically underestimated MIPAS random errors.

  15. Short-range communication system

    Science.gov (United States)

    Alhorn, Dean C. (Inventor); Howard, David E. (Inventor); Smith, Dennis A. (Inventor)

    2012-01-01

    A short-range communication system includes an antenna, a transmitter, and a receiver. The antenna is an electrical conductor formed as a planar coil with rings thereof being uniformly spaced. The transmitter is spaced apart from the plane of the coil by a gap. An amplitude-modulated and asynchronous signal indicative of a data stream of known peak amplitude is transmitted into the gap. The receiver detects the coil's resonance and decodes same to recover the data stream.

  16. Countering short range ballistic missiles

    OpenAIRE

    Conner, George W.; Ehiers, Mark A.; Marshall, Kneale T.

    1993-01-01

    Approved for public release; distribution is unlimited. Concepts commonly found in ASW search are used to model the flow and detection of mobile launchers for short range ballistic missiles. Emphasis is on detection and destruction of the launcher before launch. The benefit of pre-hostility intelligence and pre-missile-launch prosecution, the backbone of successful ASW, is revealed through the analysis of a circulation model which reflects the standard operations of a third world mobile mi...

  17. Fast, multi-phase H2O measurements on board of HALO: Results from the novel HAI instrument during the first field campaigns.

    Science.gov (United States)

    Buchholz, Bernhard; Afchine, Armin; Krämer, Martina; Ebert, Volker

    2014-05-01

    Water vapor is a key species for many questions in atmospheric research [1] [2] but is also a gas species which is complex to handle. A particular challenge is the simultaneous quantification of gas and condensed phase water. This is especially true for measurements on airborne platforms but also for laboratory experiments [3]. On research aircraft, total water measurement (i.e. the sum of gas-phase and ice-phase) is realized by sampling air with an inlet faced into flight direction ('forward' sampling) and subsequent evaporation of the ice crystals in the heated sampling lines. Gas-phase detection is typically realized using inlets facing against flight direction ('backward' sampling) or 'Rosemount' inlets where an air stream is sampled perpendicular to the high speed airflow through the inlet. For both methods it is believed that no ice crystals reach the downstream hygrometer, but the question remains - especially for Rosemount inlets - if some small ice particles or water droplets may have entered the sampling lines. In addition to the question of proper sampling of the water phases, currently no hygrometer exists that measures all phases with the same measurement principle in one instrument. In the rare occasions that multi-phase measurements are realized, gas-and condensed-phase observations rely on different methods and calibration strategies so that precision and accuracy levels are difficult to compare. The novel HAI (Hygrometer for Atmospheric Investigation) realizes a simultaneous multi-phase hygrometer in a unique concept [4]. Water detection with HAI is based on Tunable Diode Laser Absorption Spectroscopy (TDLAS) with a special evaluation method allowing absolute water vapor measurements without any sensor calibration [5]. The HAI instrument contains two independent dual-channel spectrometers, one at 1.4 μm and one at 2.6 μm which allows to cover a very wide water concentration range from 1 to 30 000 ppmv. Both HAI spectrometers couple one light path

  18. Examinations of tRNA Range of Motion Using Simulations of Cryo-EM Microscopy and X-Ray Data

    Directory of Open Access Journals (Sweden)

    Thomas R. Caulfield

    2011-01-01

    Full Text Available We examined tRNA flexibility using a combination of steered and unbiased molecular dynamics simulations. Using Maxwell's demon algorithm, molecular dynamics was used to steer X-ray structure data toward that from an alternative state obtained from cryogenic-electron microscopy density maps. Thus, we were able to fit X-ray structures of tRNA onto cryogenic-electron microscopy density maps for hybrid states of tRNA. Additionally, we employed both Maxwell's demon molecular dynamics simulations and unbiased simulation methods to identify possible ribosome-tRNA contact areas where the ribosome may discriminate tRNAs during translation. Herein, we collected >500 ns of simulation data to assess the global range of motion for tRNAs. Biased simulations can be used to steer between known conformational stop points, while unbiased simulations allow for a general testing of conformational space previously unexplored. The unbiased molecular dynamics data describes the global conformational changes of tRNA on a sub-microsecond time scale for comparison with steered data. Additionally, the unbiased molecular dynamics data was used to identify putative contacts between tRNA and the ribosome during the accommodation step of translation. We found that the primary contact regions were H71 and H92 of the 50S subunit and ribosomal proteins L14 and L16.

  19. Medium Range Forecasts Representation (and Long Range Forecasts?)

    Science.gov (United States)

    Vincendon, J.-C.

    2009-09-01

    The progress of the numerical forecasts urges us to interest us in more and more distant ranges. We thus supply more and more forecasts with term of some days. Nevertheless, precautions of use are necessary to give the most reliable and the most relevant possible information. Available in a TV bulletin or on quite other support (Internet, mobile phone), the interpretation and the representation of a medium range forecast (5 - 15 days) must be different from those of a short range forecast. Indeed, the "foresee-ability” of a meteorological phenomenon decreases gradually in the course of the ranges, it decreases all the more quickly that the phenomenon is of small scale. So, at the end of some days, the probability character of a forecast becomes very widely dominating. That is why in Meteo-France the forecasts of D+4 to D+7 are accompanied with a confidence index since around ten years. It is a figure between 1 and 5: the more we approach 5, the more the confidence in the supplied forecast is good. In the practice, an indication is supplied for period D+4 / D+5, the other one for period D+6 / D+7, every day being able to benefit from a different forecast, that is be represented in a independent way. We thus supply a global tendency over 24 hours with less and less precise symbols as the range goes away. Concrete examples will be presented. From now on two years, we also publish forecasts to D+8 / J+9, accompanied with a sign of confidence (" good reliability " or " to confirm "). These two days are grouped together on a single map because for us, the described tendency to this term is relevant on a duration about 48 hours with a spatial scale slightly superior to the synoptic scale. So, we avoid producing more than two zones of types of weather over France and we content with giving an evolution for the temperatures (still, in increase or in decline). Newspapers began to publish this information, it should soon be the case of televisions. It is particularly

  20. Truthful approximations to range voting

    DEFF Research Database (Denmark)

    Filos-Ratsika, Aris; Miltersen, Peter Bro

    We consider the fundamental mechanism design problem of approximate social welfare maximization under general cardinal preferences on a finite number of alternatives and without money. The well-known range voting scheme can be thought of as a non-truthful mechanism for exact social welfare......-unilateral has an approximation ratio between 0.610 and 0.611, the best ordinal mechanism has an approximation ratio between 0.616 and 0.641, while the best mixed-unilateral mechanism has an approximation ratio bigger than 0.660. In particular, the best mixed-unilateral non-ordinal (i.e., cardinal) mechanism...