Science.gov

Sample records for absolute thermal emf

  1. Thermal emf generated by laser emission along thin metal films

    NASA Astrophysics Data System (ADS)

    Konov, V. I.; Nikitin, P. I.; Satiukov, D. G.; Uglov, S. A.

    1991-07-01

    Substantial pulse thermal emf values (about 1.5 V) have been detected along the substrate during the interaction of laser emission with thin metal films (Ni, Ti, and Bi) sprayed on corrugated substrates. Relationships are established between the irradiation conditions and parameters of the generated electrical signals. Possible mechanisms of thermal emf generation and promising applications are discussed.

  2. Correction for Thermal EMFs in Thermocouple Feedthroughs

    NASA Technical Reports Server (NTRS)

    Ziemke, Robert A.

    2006-01-01

    A straightforward measurement technique provides for correction of thermal-electromotive-force (thermal-EMF) errors introduced by temperature gradients along the pins of non-thermocouple-alloy hermetic feedthrough connectors for thermocouple extension wires that must pass through bulkheads. This technique is an alternative to the traditional technique in which the thermal-EMF errors are eliminated by use of custom-made multipin hermetic feedthrough connectors that contain pins made of the same alloys as those of the thermocouple extension wires. One disadvantage of the traditional technique is that it is expensive and time-consuming to fabricate multipin custom thermocouple connectors. In addition, the thermocouple-alloy pins in these connectors tend to corrode easily and/or tend to be less rugged compared to the non-thermocouple-alloy pins of ordinary connectors. As the number of thermocouples (and thus pins) is increased in a given setup, the magnitude of these disadvantages increases accordingly. The present technique is implemented by means of a little additional hardware and software, the cost of which is more than offset by the savings incurred through the use of ordinary instead of thermocouple connectors. The figure schematically depicts a typical measurement setup to which the technique is applied. The additional hardware includes an isothermal block (made of copper) instrumented with a reference thermocouple and a compensation thermocouple. The reference thermocouple is connected to an external data-acquisition system (DAS) through a two-pin thermocouple-alloy hermetic feedthrough connector, but this is the only such connector in the apparatus. The compensation thermocouple is connected to the DAS through two pins of the same ordinary multipin connector that connects the measurement thermocouples to the DAS.

  3. Crystal morphology and thermal EMF of pyrites in the western flank of Sukholozhsky gold ore field (Lenski ore area)

    NASA Astrophysics Data System (ADS)

    Gavrilov, R.; Pshenichkin, A.; Ponamarenko, M.; Abramova, R.

    2015-11-01

    The investigated crystal morphology and thermal EMF of pyrites in the western flank of Sukholozsky ore field showed that the pyrite crystals have cubic habitus with a weakly-developed face {210}. The crystal faces {100} and {210} are covered with multiple irregular-oriented growth laminae. It has been determined that pyrites have such a property as p-type conduction and embrace insignificant thermal EMF variations. The results of the research indicated the fact of upper ore zone erosion in the western flank of Sukholozhsky ore field and its area potential at depth.

  4. Casimir EMF

    E-print Network

    Fateev, Evgeny G

    2015-01-01

    In the present paper, it is shown that the existence of the Casimir electromotive force (EMF) is possible in nanosized configurations with nonclosed nonparallel metal plates. The nature of such EMF is associated with the drag current generation at the noncompensated Casimir action of virtual photons on the electrons in the nano-configurations. In the case of a classical configuration withstrictly parallel plates, EMF is not generated. However, EMF can be generated when even an insignificant angle between the plates appears. Angles between the plates and their effective lengths have been found, at which maximally possible EMF is generated in a configuration.

  5. Casimir EMF

    E-print Network

    Evgeny G. Fateev

    2015-09-14

    In the present paper, it is shown that the existence of the Casimir electromotive force (EMF) is possible in nanosized configurations with nonclosed nonparallel metal plates. The nature of such EMF is associated with the drag current generation at the noncompensated Casimir action of virtual photons on the electrons in the nano-configurations. In the case of a classical configuration withstrictly parallel plates, EMF is not generated. However, EMF can be generated when even an insignificant angle between the plates appears. Angles between the plates and their effective lengths have been found, at which maximally possible EMF is generated in a configuration.

  6. Thermal properties of solid-state Pt/TiO2/Ti emf cells studied by microcalorimetry

    NASA Astrophysics Data System (ADS)

    Cakabay, Ömer; Achhab, Mhamed El; Schierbaum, Klaus

    2015-03-01

    We have studied the temperature dependence of generated current during hydrogen-to-water oxidation over Pt/TiO2/Ti layer structures in which the oxide is grown by high-voltage electrochemical anodization of a titanium foil. The platinum contact is prepared using a paste process. We found that the generator effect breaks down completely at temperatures above 65 °C. By means of an isothermally operated microcalorimeter setup, the temperature dependence of the reaction was determined under flow conditions and evaluated in a thermodynamic constant-volume approach. Three different regimes can be distinguished between 1 and 157.3 °C in which the rate of reaction is controlled by either the activation energy of the reaction, the pore diffusion or the film diffusion. Based on the data, the thermal properties of solid-state Pt/TiO2/Ti emf cells are explained.

  7. Absolute Thermal SST Measurements over the Deepwater Horizon Oil Spill

    NASA Astrophysics Data System (ADS)

    Good, W. S.; Warden, R.; Kaptchen, P. F.; Finch, T.; Emery, W. J.

    2010-12-01

    Climate monitoring and natural disaster rapid assessment require baseline measurements that can be tracked over time to distinguish anthropogenic versus natural changes to the Earth system. Disasters like the Deepwater Horizon Oil Spill require constant monitoring to assess the potential environmental and economic impacts. Absolute calibration and validation of Earth-observing sensors is needed to allow for comparison of temporally separated data sets and provide accurate information to policy makers. The Ball Experimental Sea Surface Temperature (BESST) radiometer was designed and built by Ball Aerospace to provide a well calibrated measure of sea surface temperature (SST) from an unmanned aerial system (UAS). Currently, emissive skin SST observed by satellite infrared radiometers is validated by shipborne instruments that are expensive to deploy and can only take a few data samples along the ship track to overlap within a single satellite pixel. Implementation on a UAS will allow BESST to map the full footprint of a satellite pixel and perform averaging to remove any local variability due to the difference in footprint size of the instruments. It also enables the capability to study this sub-pixel variability to determine if smaller scale effects need to be accounted for in models to improve forecasting of ocean events. In addition to satellite sensor validation, BESST can distinguish meter scale variations in SST which could be used to remotely monitor and assess thermal pollution in rivers and coastal areas as well as study diurnal and seasonal changes to bodies of water that impact the ocean ecosystem. BESST was recently deployed on a conventional Twin Otter airplane for measurements over the Gulf of Mexico to access the thermal properties of the ocean surface being affected by the oil spill. Results of these measurements will be presented along with ancillary sensor data used to eliminate false signals including UV and Synthetic Aperture Radar (SAR) information. Spatial variations and day-to-day changes in the visible oil concentration on the surface of the water were observed in performing these measurements. An assessment of the thermal imagery variation will be made based on the absolute calibration of the sensor to determine if the visible variation was due to properties of the reflected light or of the actual oil composition. Comparisons with satellite data (both SAR and thermal infrared images) and buoy data will also be included.

  8. Strong thermal leptogenesis and the absolute neutrino mass scale

    SciTech Connect

    Bari, Pasquale Di; King, Sophie E.; Fiorentin, Michele Re E-mail: sk1806@soton.ac.uk

    2014-03-01

    We show that successful strong thermal leptogenesis, where the final asymmetry is independent of the initial conditions and in particular a large pre-existing asymmetry is efficiently washed-out, favours values of the lightest neutrino mass m{sub 1}?>10 meV for normal ordering (NO) and m{sub 1}?>3 meV for inverted ordering (IO) for models with orthogonal matrix entries respecting |?{sub ij}{sup 2}|?<2. We show analytically why lower values of m{sub 1} require a higher level of fine tuning in the seesaw formula and/or in the flavoured decay parameters (in the electronic for NO, in the muonic for IO). We also show how this constraint exists thanks to the measured values of the neutrino mixing angles and could be tightened by a future determination of the Dirac phase. Our analysis also allows us to place a more stringent constraint for a specific model or class of models, such as SO(10)-inspired models, and shows that some models cannot realise strong thermal leptogenesis for any value of m{sub 1}. A scatter plot analysis fully supports the analytical results. We also briefly discuss the interplay with absolute neutrino mass scale experiments concluding that they will be able in the coming years to either corner strong thermal leptogenesis or find positive signals pointing to a non-vanishing m{sub 1}. Since the constraint is much stronger for NO than for IO, it is very important that new data from planned neutrino oscillation experiments will be able to solve the ambiguity.

  9. SCIENTIFIC CORRESPONDENCE Ferromagnetism and EMFs

    E-print Network

    Kirschvink, Joseph L.

    SCIENTIFIC CORRESPONDENCE Ferromagnetism and EMFs such they constitute roughly half of the projects of EMF. However, any effect of EMF exposure on cultured cells, if it is due to the presence of whether weak, extremely low-frequency electromagnetic fields (EMFs) can cause cancer always generates

  10. Onboard Real-Time Absolute Radiometric Calibration for Thermal Infrared Channels of Chinese Geostationary Meteorological Satellites

    E-print Network

    Dery, Stephen

    Onboard Real-Time Absolute Radiometric Calibration for Thermal Infrared Channels of Chinese and brightness temperatures with the corresponding DNs. In addition, the temperatures of onboard blackbody (OBB and temperatures of various mirrors, the transform equations from TOBB to TEBB are developed. Finally, the onboard

  11. Nanoscale range finding of subsurface structures by measuring the absolute phase lag of thermal wave.

    PubMed

    Chung, Jaehun; Kim, Kyeongtae; Hwang, Gwangseok; Kwon, Ohmyoung; Lee, Joon Sik; Park, Seung Ho; Choi, Young Ki

    2010-05-01

    The need for a subsurface imaging technique to locate and characterize subsurface defects in multidimensional micro- and nanoengineered devices has been growing rapidly. We show that a subsurface heater can be located accurately using the phase lag of a thermal wave. We deduce that the absolute phase lag is composed of four components. Among the four components, we isolate the component directly related to the position and the structure of the periodic heat source. We demonstrate that the position of the heater can be estimated accurately from the isolated phase lag component. PMID:20515139

  12. Nanoscale range finding of subsurface structures by measuring the absolute phase lag of thermal wave

    SciTech Connect

    Chung, Jaehun; Kim, Kyeongtae; Hwang, Gwangseok; Kwon, Ohmyoung; Lee, Joon Sik; Park, Seung Ho; Choi, Young Ki

    2010-05-15

    The need for a subsurface imaging technique to locate and characterize subsurface defects in multidimensional micro- and nanoengineered devices has been growing rapidly. We show that a subsurface heater can be located accurately using the phase lag of a thermal wave. We deduce that the absolute phase lag is composed of four components. Among the four components, we isolate the component directly related to the position and the structure of the periodic heat source. We demonstrate that the position of the heater can be estimated accurately from the isolated phase lag component.

  13. New bimetallic EMF cell shows promise in direct energy conversion

    NASA Technical Reports Server (NTRS)

    Hesson, J. C.; Shimotake, H.

    1968-01-01

    Concentration cell, based upon a thermally regenerative cell principle, produces electrical energy from any large heat source. This experimental bimetallic EMF cell uses a sodium-bismuth alloy cathode and a pure liquid sodium anode. The cell exhibits reliability, corrosion resistance, and high current density performance.

  14. What Are Electric and Magnetic Fields? (EMF)

    MedlinePLUS

    ... Print this page Share What are Electric and Magnetic Fields? (EMF) Electric and Magnetic Fields Electricity is an essential part of our ... we take for granted. What are electric and magnetic fields? Electric and magnetic fields (EMF) are invisible ...

  15. EMF Code Generation with Fujaba Leif Geiger

    E-print Network

    Westfechtel, Bernhard

    EMF Code Generation with Fujaba Leif Geiger Universität Kassel Wilhelmshöher Allee 73 34121 Kassel, but it is tightly coupled to an underlying EMF model. In this paper we show a way how to extend Fujaba's code a EMF specification. 1. INTRODUCTION In its current state Fujaba generates standard Java code which can

  16. Sourcebook for utility communications on EMF

    SciTech Connect

    Creighton, J.L.; Banks, R.S.; Duening, T. )

    1992-06-01

    All electric utilities now face, or soon will be facing, many issues over the public concern of Electric and Magnetic fields (EMF). Our purpose in writing this manual is to provide utilities with the best current information about two questions: What is the present state of scientific knowledge about EMF How can we communicate effectively with the public about EMF

  17. EUROPAEM EMF Guideline 2015 for the prevention, diagnosis and treatment of EMF-related health problems and illnesses.

    PubMed

    Belyaev, Igor; Dean, Amy; Eger, Horst; Hubmann, Gerhard; Jandrisovits, Reinhold; Johansson, Olle; Kern, Markus; Kundi, Michael; Lercher, Piero; Mosgöller, Wilhelm; Moshammer, Hanns; Müller, Kurt; Oberfeld, Gerd; Ohnsorge, Peter; Pelzmann, Peter; Scheingraber, Claus; Thill, Roby

    2015-12-01

    Chronic diseases and illnesses associated with unspecific symptoms are on the rise. In addition to chronic stress in social and work environments, physical and chemical exposures at home, at work, and during leisure activities are causal or contributing environmental stressors that deserve attention by the general practitioner as well as by all other members of the health care community. It seems certainly necessary now to take "new exposures" like electromagnetic field (EMF) into account. Physicians are increasingly confronted with health problems from unidentified causes. Studies, empirical observations, and patient reports clearly indicate interactions between EMF exposure and health problems. Individual susceptibility and environmental factors are frequently neglected. New wireless technologies and applications have been introduced without any certainty about their health effects, raising new challenges for medicine and society. For instance, the issue of so-called non-thermal effects and potential long-term effects of low-dose exposure were scarcely investigated prior to the introduction of these technologies. Common EMF sources include Wi-Fi access points, routers and clients, cordless and mobile phones including their base stations, Bluetooth devices, ELF magnetic fields from net currents, ELF electric fields from electric lamps and wiring close to the bed and office desk. On the one hand, there is strong evidence that long-term-exposure to certain EMF exposures is a risk factor for diseases such as certain cancers, Alzheimer's disease and male infertility. On the other hand, the emerging electromagnetic hypersensitivity (EHS) is more and more recognized by health authorities, disability administrators and case workers, politicians, as well as courts of law. We recommend treating EHS clinically as part of the group of chronic multisystem illnesses (CMI) leading to a functional impairment (EHS), but still recognizing that the underlying cause remains the environment. In the beginning, EHS symptoms often occur only occasionally, but over time they may increase in frequency and severity. Common EHS symptoms include headaches, concentration difficulties, sleeping problems, depression, lack of energy, fatigue and flu-like symptoms. A comprehensive medical history, which should include all symptoms and their occurrences in spatial and temporal terms and in the context of EMF exposures, is the key to the diagnosis. The EMF exposure can be assessed by asking for typical sources like Wi-Fi access points, routers and clients, cordless and mobile phones and measurements at home and at work. It is very important to take the individual susceptibility into account. The primary method of treatment should mainly focus on the prevention or reduction of EMF exposure, that is, reducing or eliminating all sources of EMF at home and in the workplace. The reduction of EMF exposure should also be extended to public spaces such as schools, hospitals, public transport, and libraries to enable persons with EHS an unhindered use (accessibility measure). If a detrimental EMF exposure is reduced sufficiently, the body has a chance to recover and EHS symptoms will be reduced or even disappear. Many examples have shown that such measures can prove effective. Also the survival rate of children with leukemia depends on ELF magnetic field exposure at home. To increase the effectiveness of the treatment, the broad range of other environmental factors that contribute to the total body burden should also be addressed. Anything that supports a balanced homeostasis will increase a person's resilience against disease and thus against the adverse effects of EMF exposure. There is increasing evidence that EMF exposure has a major impact on the oxidative and nitrosative regulation capacity in affected individuals. This concept also may explain why the level of susceptibility to EMF can change and why the number of symptoms reported in the context of EMF exposures is so large. Based on our current understanding, a treatment approach that minimizes

  18. EMF and the public health

    SciTech Connect

    Krieger, R.W.; Withey, M.E.

    1994-12-31

    The availability of reasonably priced electric power underpins the American standard of living, the nation`s industrial strength, and even our creature comforts. Utility experts estimate that by the end of this century electric utility infrastructure such as transmission lines, distribution lines, substations, and the like will expand by as much as 15 percent to serve increased customer demands for power. The electric utility industry today, however, is faced with an unanticipated consequence of its own success as health questions have been raised regarding electric and magnetic fields (EMF or EMR). These fields are created whenever electric current passes through power lines or electrical equipment. While people are exposed to EMF from electrical appliances, household wiring, and even household water pipes to which the home electrical system has been grounded, most of the attention has centered on high-voltage transmission lines and, to a lesser extent, neighborhood distribution lines. The scientific debate has been fueled by epidemiological studies. Epidemiology, which is the study of the distribution of diseases in the human population, is useful in identifying statistical associations that may reflect a causal relationship between an exposure and a disease. Some EMF epidemiological studies have reported positive statistical associations between residential and occupational exposures to EMF and certain childhood and adult cancers, including leukemia, brain cancer, lymphoma, and breast cancer. While scientists debate the meaning of these studies and conduct further studies, the debate is now moving into America`s courtrooms as private litigants seek compensation for physical harm and damage to property values.

  19. EMF Responses in Farm Animals

    SciTech Connect

    Anderson, Larry E. ); R Matthes, JH Bernhardt, and MH Repacholi

    1999-10-19

    Relatively few studies have been performed investigating the effects of EMF exposure on farm animals. Most of those that have been described in the literature are of surveys of animals living in the vicinity of power transmission lines. Even fewer studies have been conducted in large animals under controlled laboratory conditions. Results generally provide little evidence that electric and/or magnetic fields at environmental levels (under transmission lines up to 1000 kV) affect farm animals. There is limited evidence that cows exposed to EMF may exhibit slight changes in length of estrous cycle, although associated hormones (eg. progesterone) appear to be unaffected. The effects of electric fields on development in swine (some increase in birth defects and malformations) exposed to high strength electric fields were not consistent across generations nor supported by comparable rodent studies. Finally, electrical currents and"stray voltages", parameters associated with EMF, are found on some farms above perception levels. These voltages and currents can produce behavioral changes in farm animals and may impact production or health of the animals.

  20. Characterizing Thermal Expansion of the Piston Gauge in the Absolute Self-Calibrating Pressure Recorder

    NASA Astrophysics Data System (ADS)

    Cook, Matthew James

    Vertical seafloor deformation can be measured using pressure, since ambient seawater pressure is a proxy for depth. However, most quartz pressure gauges experience drift that can contaminate expected geodetic signals. An instrument called the Self-Calibrating Pressure Recorder (SCPR) was developed to compensate for the effects of drift by using a piston gauge to supply a stable reference pressure. SCPR deployments are limited to two years, so to collect longer geodetic records over years to decades the Absolute Self-Calibrating Pressure Recorder (ASCPR) was developed. The ASCPR uses the same calibration system as the SCPR, but instead makes campaign-style measurements of the true, absolute value of pressure. In order for measurements to be accurate, the calibration system components must be known to a few parts per million (ppm). However, during the deployment and the measurement periods, the ASCPR is susceptible to changes in pressure on the order of 100 ppm, due to temperature changes. In the lab, we exposed the ASCPR to temperature changes while measuring the reference pressure to characterize the effects of thermal expansion on the piston gauge. The corrected pressures were stable at a 95% confidence level of +/-0.23 kPa, or 2.3 cm equivalent, corresponding to a 13 ppm effect at a simulated pressure of 19,000 kPa. We also determined the thermal expansion effects had a time constant of 5.9 hours, which allows us to determine the changes over time, thereby reducing the amount of time required for the instrument to stabilize. Finally, the coefficient of thermal expansion that minimized the uncertainty in the pressure was less than the nominal value stated by the manufacturer. The uncertainty remained at the 13 ppm level, larger than our desired uncertainty of less than 10 ppm. At this level, the ASCPR can be used to detect larger geodetic signals, but requires further improvements to monitor slow deformation and sea level. My thesis is focused on evaluating the accuracy of the ASCPR and how it depends on the temperature variations during deployment.

  1. Containing the costs of the EMF problem

    SciTech Connect

    Florig, H.K. )

    1992-07-24

    The uncertainty surrounding possible health effects of power-frequency electric and magnetic fields (EMF's) is fueling a costly controversy over the safety of high voltage transmission lines, neighborhood power-distribution circuits, home and office wiring, elelctrical appliances, and office equipment. Mounting public concerns are driven primarily by a number of epidemiological studies that show increased risks of cancer among populations thought to experience unusual patterns of EMF exposure. Because the scientific evidence on EMF bioeffects is both complicated and contradictory, regulatory bodies and scientific standard-setting organizations have been unable to reach consensus on prescriptive approaches to EMF risk management. Although scientific opinion varies widely about whether the EMF-cancer connection is real, public apprehension over potential EMF hazards has prompted a host of political, legal, and market reactions.

  2. Cell biology and EMF safety standards.

    PubMed

    Blank, Martin

    2015-12-01

    Living cells react defensively and start to synthesize stress proteins when exposed to potentially harmful stimuli. Electromagnetic fields (EMF) are among the many different environmental stimuli that initiate stress protein synthesis. Although there is greater energy transfer and heating due to EMF at higher frequencies, there is no greater stress response. The cellular stress response is far more sensitive to EMF than to an increase in temperature. It should be obvious that an EMF safety standard should be based on the more sensitive, natural biological response. PMID:25152029

  3. EMF: Liability, prudent avoidance, and communication

    SciTech Connect

    Watson, T.; Warnquist, M.

    1991-04-01

    The authors conclude that there is a growing need for utilities to be truly sensitive to public concerns about potential EMF health risks. It is not in a utility's long-term litigation interest - or other interest - to adopt a position on EMF health issues that does not fully recognize the nature and extent of the current scientific inquiry. Nor should utilities adopt a position that reads more into the EMF research than the research itself supports. Instead, the authors; experience suggests that litigation and other interests are best served by a balanced approach to EMF health and public policy issues that is open, direct, and responsive to public concerns.

  4. Estimation of absolute water surface temperature based on atmospherically corrected thermal infrared multispectral scanner digital data

    NASA Technical Reports Server (NTRS)

    Anderson, James E.

    1986-01-01

    Airborne remote sensing systems, as well as those on board Earth orbiting satellites, sample electromagnetic energy in discrete wavelength regions and convert the total energy sampled into data suitable for processing by digital computers. In general, however, the total amount of energy reaching a sensor system located at some distance from the target is composed not only of target related energy, but, in addition, contains a contribution originating from the atmosphere itself. Thus, some method must be devised for removing or at least minimizing the effects of the atmosphere. The LOWTRAN-6 Program was designed to estimate atmospheric transmittance and radiance for a given atmospheric path at moderate spectral resolution over an operational wavelength region from 0.25 to 28.5 microns. In order to compute the Thermal Infrared Multispectral Scanner (TIMS) digital values which were recorded in the absence of the atmosphere, the parameters derived from LOWTRAN-6 are used in a correction equation. The TIMS data were collected at 1:00 a.m. local time on November 21, 1983, over a recirculating cooling pond for a power plant in southeastern Mississippi. The TIMS data were analyzed before and after atmospheric corrections were applied using a band ratioing model to compute the absolute surface temperature of various points on the power plant cooling pond. The summarized results clearly demonstrate the desirability of applying atmospheric corrections.

  5. Securing insurance coverage for EMF claims

    SciTech Connect

    Meyer, K.A. )

    1992-02-15

    When confronted with lawsuits resulting from EMF-related claims, utilities must aggressively work to ensure that they receive the full protection and defense due them by their insurance companies. Within the last two years, electric utilities have been increasingly subject to claims alleging that plaintiffs have suffered bodily injury as a result of exposure to electromagnetic fields (EMF) and that this exposure has caused everything from emotional distress to cancer. The plaintiffs generally claim that EMF exposure has also caused property damage - usually in the fourth of a reduction in the value of their residence. Claims have also been made on the grounds that EMF constitutes a tresspass and nuisance, which has prevented plaintiffs from using their property to the fullest extent. While utilities may debate the degree of harm, if any, caused by exposure to EMF, one thing is certain: The current EMF claims are only the tip of the iceberg and are not likely to dissipate any time soon. As a result, utilities must example their insurance coverage to determine whether any existing or future EMF claims are covered under the company's policies. Such insurance would most likely help pay for the cost of defending against EMF lawsuits and indemnify the company if any liability is assessed.

  6. A Simple Demonstration of Back emf

    ERIC Educational Resources Information Center

    Turner, Lou

    2009-01-01

    In discussing motors, one college textbook says, "As the coil (of a motor) rotates in a magnetic field, a back emf is generated that tends to counter the emf that supplies the current." This is a true statement, but it does little to enhance student understanding of how and why it is created. In this paper, I will explain how to take students step…

  7. Potential EMF risks continue to worry utilities

    SciTech Connect

    Hoske, M.T.

    1994-02-01

    Risks associated with possible effects of electric and magnetic fields (the EMF issue) top the list of utility executive concerns. The EMF problem defies definition but commands increasingly higher amounts of funding and attention from utilities, the US federal government, and state regulators. Recent completed studies of EMF health effects are as inconclusive as their predecessors. Some studies have shown a mild association to some kinds of cancer in some populations, but the association and effects aren't nearly enough to justify costly corrective steps, experts agree. In the first half of this year, two utility worker studies will be released. One is by EPRI at five US utilities, and the other is by Montreal researchers for utility workers in Quebec and Ontario Canada and in France. Other research covers household wiring and plumbing configurations and grounding and appliances. Utility measurements show EMF exposure may be greater from these, than from utility facilities on the other side of the meter.

  8. A Novel Portable Absolute Transient Hot-Wire Instrument for the Measurement of the Thermal Conductivity of Solids

    NASA Astrophysics Data System (ADS)

    Assael, Marc J.; Antoniadis, Konstantinos D.; Metaxa, Ifigeneia N.; Mylona, Sofia K.; Assael, John-Alexander M.; Wu, Jiangtao; Hu, Miaomiao

    2015-08-01

    A new portable absolute Transient Hot-Wire instrument for measuring the thermal conductivity of solids over a range of 0.2 W{\\cdot }m^{-2}{\\cdot }K^{-1} to 4 W{\\cdot }m^{-1}{\\cdot }K^{-1} is presented. The new instrument is characterized by three novelties: (a) an innovative two-wires sensor which provides robustness and portability, while at the same time employs a soft silicone layer to eliminate the effect of the contact resistance between the wires and the sample, (b) a newly designed compact portable printed electronic board employing an FPGA architecture CPU to the control output voltage and data processing—the new board replaces the traditional, large in size Wheatstone-type bridge system required to perform the experimental measurements, and (c) a cutting-edge software suite, developed for the mesh describing the structure of the sensor, and utilizing the Finite Elements Method to model the heat flow. The estimation of thermal conductivity is modeled as a minimization problem and is solved using Bayesian Optimization. Our revolutionizing proposed methodology exhibits radical speedups of up to × 120, compared to previous approaches, and considerably reduces the number of simulations performed, achieving convergence only in a few minutes. The new instrument was successfully employed to measure, at room temperature, the thermal conductivity of two thermal conductivity reference materials, Pyroceram 9606 and Pyrex 7740, and two possible candidate glassy solids, PMMA and BK7, with an absolute low uncertainty of 2 %.

  9. Analysis of induced EMF waveforms and torque ripple in a brushless permanent magnet machine

    SciTech Connect

    Sebastian, T.; Gangla, V.

    1996-01-01

    Permanent magnet machines with trapezoidal back EMF waveform have been the subject of several papers in the past. The simplicity in control and the absence of an absolute position sensor makes this type of motor very attractive. Idealized analysis of such a machine is simple and will result in trapezoidal or square wave back EMF waveforms depending on the assumptions made. In the case of an idealized quasi-square wave current excitation, a ripple-free torque will be obtained. The actual back EMF waveform of these machines depends on the flux density and the conductor distributions. This in turn is a function of the magnet magnetization and the stator tooth and slot structure. In applications where a fairly smooth torque is needed, these machines are made with either the stator slots or the rotor magnets skewed by one slot. This paper deals with the analysis of the back EMF waveform and of the torque ripple waveform of such a machine when the stator slots or rotor magnets are skewed by one slot. The analysis takes into consideration the actual stator conductor distribution and the effect of magnet magnetization on the back EMF waveform. An empirical formula is developed for the magnet flux density distribution which could be used for various magnetization conditions of the magnet. Experimental results are included to confirm the analytical results.

  10. Meadow street family files EMF suit

    SciTech Connect

    Greenberger, L.S.

    1992-02-15

    When Arthur Bryant spoke to an electromagnetic fields (EMF) conference last March in Washington, D.C., he promised the group one thing: [open quotes]EMF [court]cases are coming.[close quotes] Last month, Bryant, executive director of Trial Lawyers for Public Justice (TLPJ), kept that promise when TLPJ filed a lawsuit in Connecticut Superior Court against Northeast Utilities (NU) and its subsidiary Connecticut Light and Power (CL P) on behalf of Melissa Bullock and her family. The Bullocks live near CL P's Meadow Street substation in Guilford, Connecticut, and TLPJ contends that 19-year-old Melissa's cancerous brain tumor was caused by EMF emanating from the substation. For ten years, TLPJ and the family claim, Melissa slept directly underneath the line from the substation that serves the Bullock home. Now they are seeking punitive and compensatory damages from NU and CL P for Melissa's condition, her mother Suzanne's emotional distress, and the lost value of their home, as well as injunctive relief that would force the companies to [open quotes]cease the emission of dangerous levels of EMF onto the plaintiff's property[close quotes] and to disclose information about the risks of EMF to the public.

  11. Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations

    NASA Astrophysics Data System (ADS)

    Pravec, Petr; Harris, Alan W.; Kušnirák, Peter; Galád, Adrián; Hornoch, Kamil

    2012-09-01

    We obtained estimates of the Johnson V absolute magnitudes (H) and slope parameters (G) for 583 main-belt and near-Earth asteroids observed at Ond?ejov and Table Mountain Observatory from 1978 to 2011. Uncertainties of the absolute magnitudes in our sample are <0.21 mag, with a median value of 0.10 mag. We compared the H data with absolute magnitude values given in the MPCORB, Pisa AstDyS and JPL Horizons orbit catalogs. We found that while the catalog absolute magnitudes for large asteroids are relatively good on average, showing only little biases smaller than 0.1 mag, there is a systematic offset of the catalog values for smaller asteroids that becomes prominent in a range of H greater than ?10 and is particularly big above H ? 12. The mean (Hcatalog - H) value is negative, i.e., the catalog H values are systematically too bright. This systematic negative offset of the catalog values reaches a maximum around H = 14 where the mean (Hcatalog - H) is -0.4 to -0.5. We found also smaller correlations of the offset of the catalog H values with taxonomic types and with lightcurve amplitude, up to ?0.1 mag or less. We discuss a few possible observational causes for the observed correlations, but the reason for the large bias of the catalog absolute magnitudes peaking around H = 14 is unknown; we suspect that the problem lies in the magnitude estimates reported by asteroid surveys. With our photometric H and G data, we revised the preliminary WISE albedo estimates made by Masiero et al. (Masired, J.R. et al. [2011]. Astrophys. J. 741, 68-89) and Mainzer et al. (Mainzer, A. et al. [2011b]. Astrophys. J. 743, 156-172) for asteroids in our sample. We found that the mean geometric albedo of Tholen/Bus/DeMeo C/G/B/F/P/D types with sizes of 25-300 km is pV = 0.057 with the standard deviation (dispersion) of the sample of 0.013 and the mean albedo of S/A/L types with sizes 0.6-200 km is 0.197 with the standard deviation of the sample of 0.051. The standard errors of the mean albedos are 0.002 and 0.006, respectively; systematic observational or modeling errors can predominate over the quoted formal errors. There is apparent only a small, marginally significant difference of 0.031 ± 0.011 between the mean albedos of sub-samples of large and small (divided at diameter 25 km) S/A/L asteroids, with the smaller ones having a higher albedo. The difference will have to be confirmed and explained; we speculate that it may be either a real size dependence of surface properties of S type asteroids or a small size-dependent bias in the data (e.g., a bias towards higher albedos in the optically-selected sample of asteroids). A trend of the mean of the preliminary WISE albedo estimates increasing with asteroid size decreasing from D ? 30 down to ?5 km (for S types) showed in Mainzer et al. (Mainzer, A. et al. [2011a]. Astrophys. J. 741, 90-114) appears to be mainly due to the systematic bias in the MPCORB absolute magnitudes that progressively increases with H in the corresponding range H = 10-14.

  12. Identifying Student Difficulties with Understanding Induced EMF

    E-print Network

    Secrest, S; Secrest, Scott; Novodvorsky, Ingrid

    2005-01-01

    This paper reports on a study of student understanding of induced EMF. Students enrolled in a physics lab course completed a pretest and posttest that included questions about induced EMF. Following the posttest, some of those students participated in interviews in which they elaborated on their ideas. Pretest and posttest data are presented in the article, as well as sample interview text. After instruction in the lab course, most students were able to identify that moving a magnet near a coil would induce a current. However, nearly half were unable to correctly determine the direction of the induced current. Many students also demonstrated difficulty with the idea that an EMF is induced by a changing magnetic flux, not just a changing magnetic field.

  13. Another blow weakens EMF-cancer link

    SciTech Connect

    Taubes, G.

    1995-09-29

    This article describes recent developments in the strongest evidence linking electromagnetic field exposure to cancers. Work suggesting that low-level EMF exposure can dramatically affect the workings of the Myc gene, an oncogene implicated in a host of human cancers, has been called into doubt. Two elaborate attempts to relicate the findings (Saffer and Thurston; Hasketh) have failed completely although the orginal researcher says they have still failed to replicate her protocaol in the original experiment exactly. She and her co-researcher (Goodman and Henderson) continue to report positive links between EMF and Myc RNA increases.

  14. EMF on Rails Rosa Lopez-Landa1

    E-print Network

    de Lara, Juan

    EMF on Rails Rosa L´opez-Landa1 , Julieta Noguez1 , Esther Guerra2 and Juan de Lara2 1Computer an application to edit Eclipse Modelling Framework (EMF) models through the web. 1. INTRODUCTION Web applications

  15. Proceedings: Health implications of EMF neural effects workshop

    SciTech Connect

    Anderson, L.; Birney, A.J.; Murdock, B.S.; Poole, C.; Wachtel, H.; Weil, D.

    1994-08-01

    This workshop reviewed scientific evidence on the question of whether extremely low frequency electric and magnetic fields (EMF) can affect human health from a neurological standpoint. The review examined the neurological effects of EMF at three levels of biological organization: cellular and molecular, tissue and organ, and whole organism and population. Several speakers described the status of ongoing EMF research by EPRI and other sponsors. Discussions also focused on additional investigation into EMF-related health issues.

  16. Subject Title: EMF Radiation Safety Program at the

    E-print Network

    Chan, Hue Sun

    Subject Title: EMF Radiation Safety Program at the University of Toronto Issued by: Senior, and damage some watches. 2. Time varying electric and magnetic fields (EMF) in the extremely low frequency) EMFs on the nervous system are: the direct stimulation of nerve and muscle tissue and the induction

  17. Sourcebook for utility communications on EMF. Final report

    SciTech Connect

    Creighton, J.L.; Banks, R.S.; Duening, T.

    1992-06-01

    All electric utilities now face, or soon will be facing, many issues over the public concern of Electric and Magnetic fields (EMF). Our purpose in writing this manual is to provide utilities with the best current information about two questions: What is the present state of scientific knowledge about EMF? How can we communicate effectively with the public about EMF?

  18. EMFS: Email-based Personal Cloud Storage Jagan Srinivasan

    E-print Network

    Ma, Xiaosong

    EMFS: Email-based Personal Cloud Storage Jagan Srinivasan EMC2 jaganvasan@gmail.com Wei Wei the efficacy of leveraging web-based email services to build a personal storage cloud. We present EMFS, which. This paper discusses the design and implementation of EMFS, focusing on unique challenges and opportunities

  19. An EMF Framework for Event-B Developed by

    E-print Network

    Southampton, University of

    An EMF Framework for Event-B Developed by: Colin Snook ­ University of Southampton, Fabian Fritz and dependability www.deploy-project.eu #12;EMF · Eclipse Modelling Framework (Ed Merks et al.) · Meta) · Runtime Support for building tools: ­ Command framework, Persistence, Dynamic (programmatic) EMF · Lots

  20. An EMF Framework for Event-B Developed by

    E-print Network

    Southampton, University of

    An EMF Framework for Event-B Developed by: Colin Snook ­ University of Southampton, Fabian Fritz ­ Heinrich Heine University, Düsseldorf, Alexei Illiasov ­ Newcastle University #12;EMF · Eclipse Modelling, Dynamic (programmatic) EMF · Lots of related technologies ­ Compare/merge, M2M, M2Text #12;Eclipse Rodin

  1. Prognostic value of preoperative absolute lymphocyte count in recurrent hepatocellular carcinoma following thermal ablation: a retrospective analysis

    PubMed Central

    Li, Xin; Han, Zhiyu; Cheng, Zhigang; Yu, Jie; Yu, Xiaoling; Liang, Ping

    2014-01-01

    Purpose To investigate the prognostic value of preoperative absolute lymphocyte count (ALC) in recurrent hepatocellular carcinoma (RHCC) following thermal ablation. Materials and methods We retrospectively analyzed the relationship between preoperative ALC and the clinicopathologic factors and long-term prognosis in 423 RHCC patients who underwent curative thermal ablation. Correlation analysis, receiver operating characteristic (ROC) calculation, Kaplan–Meier curves, and multivariate regression were used for statistical analysis. Results The median time to recurrence was 12 months for RHCC patients after thermal ablation. On multivariate Cox regression analysis, preoperative ALC was an independent risk factor for cancer recurrence, along with tumor differentiation and ?-fetoprotein level. ALC ?1.64×109/L defined by ROC calculation was associated with prolonged survival (area under the curve 0.741, P<0.001). Patients with ALC ?1.64×109/L showed a mean survival of 20.2 months versus 11.6 months for patients with ALC <1.64×109/L (P<0.001). Patients were stratified into high and low groups according to ALC status. After excluding the basic parameters between groups, the 1- and 3-year recurrence rates in the high group were 20.9% and 29.5%, respectively, which were significantly lower than those of the low group (58.4% and 71.9%, respectively; P<0.001). The recurrence-free survival rates in the two groups analyzed by Kaplan–Meier curves were significantly different (P<0.001). Conclusion Preoperative ALC is a powerful prognostic factor for RHCC recurrence after thermal ablation, which suggests that maintaining a high ALC in RHCC patients might improve cancer outcomes. PMID:25336974

  2. Easy Absolute Values? Absolutely

    ERIC Educational Resources Information Center

    Taylor, Sharon E.; Mittag, Kathleen Cage

    2015-01-01

    The authors teach a problem-solving course for preservice middle-grades education majors that includes concepts dealing with absolute-value computations, equations, and inequalities. Many of these students like mathematics and plan to teach it, so they are adept at symbolic manipulations. Getting them to think differently about a concept that they…

  3. Effect of EMF on minimum cost power transmission

    SciTech Connect

    Abdul-Rahman, K.H.; Shahidehpour, S.M.; Deeb, N.I.

    1994-12-31

    The concern about electromagnetic field (EMF) effects on human health has heightened public awareness of overhead transmission lines planning and operation. The objective of this paper is to study the effect of EMF constraints on optimal power generation scheduling. This study considers reducing EMF levels associated with critical transmission lines by redistributing the scheduled power generation, while maintaining the minimum operation cost as an objective. The EMF constraints are given in terms of control variables and fuzzy sets are utilized to model the tradeoff between minimizing the objective function and satisfying EMF constraints. Numerical results for the application of the proposed approach to test systems are discussed.

  4. Effect of EMF on minimum cost power transmission

    SciTech Connect

    Abdul-Rahman, K.H.; Shahidehpour, S.M.; Deeb, N.I.

    1995-02-01

    The concern about electromagnetic field (EMF) effects on human health has heightened public awareness of overhead transmission lines planning and operation. The objective of this paper is to study the effect of EMF constraints on optimal power generation scheduling. This study considers reducing EMF levels associated with critical transmission lines by redistributing the scheduled power generation, while maintaining the minimum operation cost as an objective. The EMF constraints are given in terms of control variables and fuzzy sets are utilized to model the tradeoff between minimizing the objective function and satisfying EMF constraints. Numerical results for the application of the proposed approach to test systems are discussed.

  5. Designing EMF experiments: What is required to characterize ``exposure``?

    SciTech Connect

    Valberg, P.A. |

    1995-12-31

    Anyone who has attempted to organize and synthesize the results of research on biological effects of electric and magnetic fields (EMF) has experienced frustration when trying to evaluate the comparability of EMF exposures among separate studies. Reporting of exposure characteristics is often incomplete, and some investigators focus on particular nuances of exposure, which in other laboratories go unrecorded because they are not regarded as important. The obstacles encountered when comparing studies, when designing replication studies, and when evaluating research proposals could be reduced were a more standardized approach taken in describing EMF exposure. To this end, a numerical listing of 18 separate parameters important to EMF exposure characterization is proposed. Although the goal of this list is primarily to expedite the description of EMF exposure, references are provided to examples of EMF exposures and to detailed discussions of EMF exposure systems.

  6. Radiometric modeling of mechanical draft cooling towers to assist in the extraction of their absolute temperature from remote thermal imagery

    NASA Astrophysics Data System (ADS)

    Montanaro, Matthew

    Determination of the internal temperature of a mechanical draft cooling tower (MDCT) from remotely-sensed thermal imagery is important for many applications that provide input to energy-related process models. The problem of determining the temperature of an MDCT is unique due to the geometry of the tower and due to the exhausted water vapor plume. The radiance leaving the tower is dependent on the optical and thermal properties of the tower materials ( i.e., emissivity, BRDF, temperature, etc.) as well as the internal geometry of the tower. The tower radiance is then propagated through the exhaust plume and through the atmosphere to arrive at the sensor. The expelled effluent from the tower consists of a warm plume with a higher water vapor concentration than the ambient atmosphere. Given that a thermal image has been atmospherically compensated, the remaining sources of error in extracted tower temperature due to the exhausted plume and the tower geometry must be accounted for. A temperature correction factor due to these error sources is derived through the use of three-dimensional radiometric modeling. A range of values for each important parameter are modeled to create a target space (i.e. , look-up table) that predicts the internal MDCT temperature for every combination of parameter values. The look-up table provides data for the creation of a fast-running parameterized model. This model, along with user knowledge of the scene, provides a means to convert the image-derived apparent temperature into the estimated absolute temperature of an MDCT.

  7. Radiometric modeling of mechanical draft cooling towers to assist in the extraction of their absolute temperature from remote thermal imagery

    NASA Astrophysics Data System (ADS)

    Montanaro, Matthew; Salvaggio, Carl; Brown, Scott D.; Messinger, David W.; Garrett, Alfred J.; Bollinger, James S.

    2009-05-01

    Determining the internal temperature of a mechanical draft cooling tower (MDCT) from remotely-sensed thermal imagery is important for many applications that provide input to energy-related process models. The problem of determining the temperature of a MDCT is unique due to the geometry of the tower and due to the exhausted water vapor plume. The radiance leaving the tower is dependent on the optical and thermal properties of the tower materials (i.e., emissivity, BRDF, temperature, etc.) and also the internal geometry of the tower. The tower radiance is then propagated through the exhaust plume and through the atmosphere to arrive at the sensor. The expelled effluent from the tower consists of a warm plume with a higher water vapor concentration than the ambient atmosphere. Given that a thermal image has been atmospherically compensated, the remaining sources of error in extracted tower temperature due to the exhausted plume and the tower geometry must be accounted for. A temperature correction factor due to these error sources will be derived through the use of three-dimensional radiometric modeling. A range of values for each important parameter are modeled to create a target space (i.e., look-up table) that predicts the internal MDCT temperature for every combination of parameter values. This LUT, along with user knowledge of the scene, provides a means to convert the imagederived apparent temperature into the estimated absolute temperature of a MDCT. Preliminary results indicate that temperature error corrections of approximately 1 - 9 Kelvin can be achieved with the range of MDCT parameters encompassed by the LUT.

  8. Changes in gene expression following EMF exposure

    SciTech Connect

    Woloschak, G.E.; Paunesku, T.; Chang-Liu, C.M.; Loberg, L.; Gauger, J.; McCormick, D.

    1997-10-01

    Experiments were designed to examine the effects of electromagnetic field (EMF) exposure on specific gene expression, an effect that can be deleterious, beneficial, or neutral, depending on the long-term consequences; however, the proof of a reproducible, quantitative biological effect (such as change in gene expression) will lead to latter experiments aimed at determining the relative contribution of these changes to cellular consequences. Past work by ourselves and by others has shown that measures of gene expression are extremely sensitive indicators of the cellular and biological effects of ionizing radiation, with transcriptional changes being detected by exposure of cells to doses of {gamma}-rays as low as 0.01 cGy that have no pronounced cellular consequences. On the basis of this work, the authors hypothesized that measures of gene expression will be equally sensitive to EMF effects on cells.

  9. No link yet, but EMF studies continue

    SciTech Connect

    1995-05-01

    The Edison Electric Institute (EEI) reports that the electric utility industry spent $10 million in 1994 on electric and magnetic fields (EMF) research conducted by the Electric Power Research Institute based in Palo Alto, California. To date, the electric utility industry has contributed close to $80 million since the 1970s. The U.S. Department of Energy (DOE) will administer an interagency EMF program in 1995 called RAPID (the Research and Public Information Dissemination program). It is a five-year, $65 million effort by DOE and the National Institute of Environmental Health Sciences (NIEHS). Some research elements are already under way. Congress has appropriated $8 million for the program in fiscal year (FY) `95. EEI member companies will contribute $4 million for FY`95 (compared to $3.2 million in FY`94) and are committed to contributing $16.5 million over the next five years.

  10. High reliability sheathed, beryllia insulated, tungsten-rhenium alloy thermocouple assemblies; their fabrication and EMF stability

    NASA Technical Reports Server (NTRS)

    Burns, G. W.; Hurst, W. S.; Scroger, M. G.

    1974-01-01

    Tantalum sheathed, BeO insulated, W-3% Re/W-25% Re thermocouple assemblies were fabricated and their emf drift determined during 2059 hours of exposure at 2073 K in a gaseous helium environment. The sheathed thermocouple assemblies were constructed from aged thermoelements, specially heat-treated BeO insulators, and specially cleaned and etched tantalum sheaths. Their thermal emf drifts ranged from the equivalent of only -0.3 to -0.8 K drift per 1000 hours of exposure at 2073 K. No evidence of any gross chemical attack or degradation of the component materials was found. The emf drift and material behavior of some unsheathed, BeO insulated, W-3% Re/W-25% Re thermocouples at 2250 and 2400 K were also determined. Unsheathed thermocouples tested in an argon environment at 2250 K for 1100 hours and at 2400 K for 307 hours exhibited changes in thermal emf that typically ranged from the equivalent of a few degrees K to as much as +11 K. Post-test examinations of these thermocouples revealed some undesirable material degradation and interaction which included erosion of the BeO insulators and contamination of the thermoelements by tantalum from the tantalum blackbody enclosure in which the thermocouples were contained.

  11. Defending against EMF property devaluation cases

    SciTech Connect

    Brandon, G.

    1995-02-01

    Late last year, New York`s highest court, the Court of Appeals, ruled that the owner of property adjacent to a utility`s high-power electrical transmission lines could seek damages for a decrease in the market value of the property caused by the fear that the power lines might cause cancer, even if such a fear was not medically or scientifically reasonable. That decision has already begun to change the outlook on electromagnetic field (EMF) litigation for utilities.

  12. Preliminary background indoor EMF measurements in Greece.

    PubMed

    Kottou, Sofia; Nikolopoulos, Dimitrios; Yannakopoulos, Panayiotis H; Vogiannis, Efstratios; Petraki, Ermioni; Panagiotaras, Dionisios; Koulougliotis, Dionysios

    2015-11-01

    The main purpose of this work was to investigate the fluctuation of Greek indoor electromagnetic field (EMF) intensity values and identify peaks that might occur. The scientific interest is mainly focused on the bands of extremely low-frequency (ELF) magnetic fields and radiofrequency (RF) electric fields which have been suggested to be possibly carcinogenic to humans by the Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR). Electromagnetic radiation (EMR) measurements were performed in a variety of indoor dwellings, in Attica and in the islands of Zakynthos and Lesvos. A total number of 4540 measurements were taken in a wide frequency range (50 Hz-2100 MHz) of which 3301 in Attica, 963 in Lesvos and 276 in Zakynthos. Statistical analysis of the data revealed specific statistically significant differences between the mean values of the electric (ELF and RF) but not the magnetic (ELF) field strengths measured at different distances from the EMF source, as well as between some of the mean values of the RF electric field at different bands. Some statistically significant differences between mean electric field values at different geographic locations were also identified. As far as the RF electric field is concerned, the maximum values, in most cases, were below 0.5 V/m, however increased values above 1 V/m and up to 5.6 V/m were occasionally observed. The ELF magnetic field values were lower than 1 ?T. It may be concluded that overall, the observed indoor EMF intensity values remained well below domestic and European established limits. PMID:26004352

  13. Development of an EMF Measurments Database, EMF Rapid Program, Project #5, Interim Report: April 1995-December 1996

    SciTech Connect

    T. Dan Bracken, Inc.

    1998-03-01

    The EMF Measurements Database project is being implemented by T. Dan Bracken, Inc. as part of the EMF Research and Public Information Dissemination (EMF RAPID) Program. The Database is a collection of data sets that relate to measurement of electric and/or magnetic fields. This report describes activities during the period January 1997 to March 1998. Primary goals for the EMF Measurements Database are to develop a database structure that can accommodate the diversity of EMF data sets, provide guidance for production of future EMF data sets, and serve as an accessible repository of EMF measurement data. Specific objectives of the EMF Measurements Database are: o to presewe study descriptions, results and data; o to provide readily accessible, well-documented data; and - o to facilitate communication among researchers. In addition, the EMF Measurements Database will encourage additional analysis of existing data sets, facilitate analysis of data from multiple projects, support design of new studies, and permit future issues in EMF exposure assessment to be addressed with existing data. Preservation of study descriptions and data is accomplished with a formal, but open, structure. Specifications have been developed for the various elements of the database. Each data set in the database is formally described by a metadata file. The structured metadata file describes the origin, development, logical and physical structure, and distribution mechanism for each data set. The metadata for each data set is generated according to a specification developed for the EMF Measurements Database. The actual measurement data is contained in data products for each data set. The number and type of data product will vary by data set. Most of the data products available from the EMF Measurements Database can be downloaded from an Internet site. For some data sets, the data products will be maintained by other patties who may have their own access procedures.

  14. Girdling Affects Ectomycorrhizal Fungal (EMF) Diversity and Reveals Functional Differences in EMF Community Composition in a Beech Forest? †

    PubMed Central

    Pena, Rodica; Offermann, Christine; Simon, Judy; Naumann, Pascale Sarah; Geßler, Arthur; Holst, Jutta; Dannenmann, Michael; Mayer, Helmut; Kögel-Knabner, Ingrid; Rennenberg, Heinz; Polle, Andrea

    2010-01-01

    The relationships between plant carbon resources, soil carbon and nitrogen content, and ectomycorrhizal fungal (EMF) diversity in a monospecific, old-growth beech (Fagus sylvatica) forest were investigated by manipulating carbon flux by girdling. We hypothesized that disruption of the carbon supply would not affect diversity and EMF species numbers if EM fungi can be supplied by plant internal carbohydrate resources or would result in selective disappearance of EMF taxa because of differences in carbon demand of different fungi. Tree carbohydrate status, root demography, EMF colonization, and EMF taxon abundance were measured repeatedly during 1 year after girdling. Girdling did not affect root colonization but decreased EMF species richness of an estimated 79 to 90 taxa to about 40 taxa. Cenococcum geophilum, Lactarius blennius, and Tomentella lapida were dominant, colonizing about 70% of the root tips, and remained unaffected by girdling. Mainly cryptic EMF species disappeared. Therefore, the Shannon-Wiener index (H?) decreased but evenness was unaffected. H? was positively correlated with glucose, fructose, and starch concentrations of fine roots and also with the ratio of dissolved organic carbon to dissolved organic nitrogen (DOC/DON), suggesting that both H? and DOC/DON were governed by changes in belowground carbon allocation. Our results suggest that beech maintains numerous rare EMF species by recent photosynthate. These EM fungi may constitute biological insurance for adaptation to changing environmental conditions. The preservation of taxa previously not known to colonize beech may, thus, form an important reservoir for future forest development. PMID:20097809

  15. Development of an EMF Measurements Database, EMF Rapid Program, Project #5, Interim Report: April 1995-December 1996

    SciTech Connect

    T. Dan Bracken, Inc.

    1997-04-01

    The EMF measurement data sets in existence today were compiled with varying goals and techniques. Consequently, they have different information content as well as varying logical and physical structure. Future studies will continue to pursue varying goals and utilize techniques that cannot be known in advance. Primary goals for the EMF Measurements Database developed under the Department of Energy EMF RAPID Program are to develop a database structure that can accommodate the diversity of EMF data sets, provide guidance for production of future EMF data sets, and serve as an accessible repository of EMF measurement data. Specific objectives of the EMF Measurements Database are: o to preserve study descriptions, results and data; o to provide readily accessible, well-documented data; and o to facilitate communication among researchers. In addition, the EMF Measurements Database will encourage additional analysis of existing data sets, facilitate analysis of data from multiple projects, support design of new studies, and permit future issues in EMF exposure assessment to be addressed with existing data. Preservation of study descriptions and data is accomplished with a formal, but open, structure. Specifications have been developed for the various elements of the database. Each data set in the database is formally described by a metadata file. The structured metadata file describes the origin, development, logical and physical structure and distribution mechanism for each data set. The metadata for each data set is generated according to a specification developed for the EMF Measurements Database. The actual measurement data is contained in data Products for each data set. The number and type of data product will vary by data set. Most of the data products in the possession of the EMF Measurements Database are available for download from an Internet site. For some data sets, the data products will be maintained by other parties who may have their own access procedures. In addition, data set contributors or users can provide reports that describe results of the study and analysis of the data with text and figures. Guidelines have been developed for preparation of reports. Access to the EMF Measurements Database is provided via an Internet site (http://www.emf-data. erg). The site provides descriptive information in a home page, . . access to data products with a file transfer protocol (ftp) address, and links to other EMF-related sites.

  16. Utilities feel weight of burden caused by EMF fears

    SciTech Connect

    Warkentin, D.

    1995-10-01

    Studies on the effects of electromagnetic fields (EMF)on human health have been conducted for more than 20 years. None have categorically established or eliminated any connection between EMF and adverse health effects. Nonetheless, 96% of the risk managers working in the utility sector view EMF as an over-riding concern. Public concern over EMF has erupted into legal, as well as regulatory, actions. To date, some utilities have had lawsuits brought against them by customers who claim they developed cancer as a result of nearby high-voltage transmission lines. What`s more, a small handfull of cities have adopted ordinances that specifically limit where and how utilities handle the placement of their transmission lines.

  17. EMF in its infancy: A call for openness

    SciTech Connect

    Norris, R.E.

    1991-05-01

    The author feels we are still in the awareness stage of EMF; the public is, for the most part, receptive to information and there is no real consus. He notes that it is this that shapes the approach of his company, PSI Energy, to public concerns about EMF: (1) when someone calls about EMF, they may just have heard about the subject; (2) someone concerned about EMF may or may not turn immediately to their local utility for information; and (3) PSI feels that, wherever a person turns, he or she should get good, factual information that permits an informed judgment. Those beliefs led directly to an important part of PSI's communications strategy: networking. Basically, networking is getting the information reprints, brochures, etc. - into the hands of the media, association's, state boards of health, etc. so that point (3) above can be handled for an anxious inquirer.

  18. EMF-cancer links: Yes, no, and maybe

    SciTech Connect

    Taubes, G.

    1993-10-29

    The controversy over whether or not low-level electromagnetic fields (EMF) can cause cancer has been smoldering for 15 years. This month it got a little hotter -- but there's still more smoke than fire. At the beginning of October, writer and EMF gadfly Paul Brodeur brought out his latest book exposing a purported EMF-cancer connection, entitled The Great Power-line Cover-up. Right on his heels, however, on 9 October, the British Medical Journal weighed in with two serious scientific assessments of the cancer risk. Unfortunately for those who long for a conclusive answer, one study found only a slight positive association between EMF and cancer, and the other found no link at all. Together the studies [open quotes]artfully provide middle-of-the-road type of evidence,[close quotes] says Dimitrios Trichopoulos, chairman of the epidemiology department at the Harvard School of Public Health.

  19. EMF Monitoring—Concepts, Activities, Gaps and Options

    PubMed Central

    Dürrenberger, Gregor; Fröhlich, Jürg; Röösli, Martin; Mattsson, Mats-Olof

    2014-01-01

    Exposure to electromagnetic fields (EMF) is a cause of concern for many people. The topic will likely remain for the foreseeable future on the scientific and political agenda, since emissions continue to change in characteristics and levels due to new infrastructure deployments, smart environments and novel wireless devices. Until now, systematic and coordinated efforts to monitor EMF exposure are rare. Furthermore, virtually nothing is known about personal exposure levels. This lack of knowledge is detrimental for any evidence-based risk, exposure and health policy, management and communication. The main objective of the paper is to review the current state of EMF exposure monitoring activities in Europe, to comment on the scientific challenges and deficiencies, and to describe appropriate strategies and tools for EMF exposure assessment and monitoring to be used to support epidemiological health research and to help policy makers, administrators, industry and consumer representatives to base their decisions and communication activities on facts and data. PMID:25216256

  20. Exposure Knowledge and Risk Perception of RF EMF

    PubMed Central

    Freudenstein, Frederik; Wiedemann, Peter M.; Varsier, Nadège

    2015-01-01

    The presented study is part of the EU-Project Low EMF Exposure Future Networks (LEXNET), which deals among other things with the issue of whether a reduction of the radiofrequency (RF) electro-magnetic fields (EMF) exposure will result in more acceptance of wireless communication networks in the public sphere. We assume that the effects of any reduction of EMF exposure will depend on the subjective link between exposure perception and risk perception (RP). Therefore we evaluated respondents’ RP of different RF EMF sources and their subjective knowledge about various exposure characteristics with regard to their impact on potential health risks. The results show that participants are more concerned about base stations than about all other RF EMF sources. Concerning the subjective exposure knowledge the results suggest that people have a quite appropriate impact model. The question how RF EMF RP is actually affected by the knowledge about the various exposure characteristics was tested in a linear regression analysis. The regression indicates that these features – except distance – do influence people’s general RF EMF RP. In addition, we analyzed the effect of the quality of exposure knowledge on RF EMF RP of various sources. The results show a tendency that better exposure knowledge leads to higher RP, especially for mobile phones. The study provides empirical support for models of the relationships between exposure perception and RP. It is not the aim to extrapolate these findings to the whole population because the samples are not exactly representative for the general public in the participating countries. PMID:25629026

  1. Thermal Imaging in the Chemistry Laboratory Thermal imaging devices take advantage of the fact that all objects with a temperature above absolute

    E-print Network

    Short, Daniel

    Thermal Imaging in the Chemistry Laboratory Thermal imaging devices take advantage of the fact the energy in the infrared radiation emitted by a viewed object into a visible light display. Thermal imaging to the temperature of the object (the Stefan-Boltzman law). Recently the cost of thermal imaging cameras has declined

  2. Human health effects of EMFs: The cost of doing nothing

    NASA Astrophysics Data System (ADS)

    Carpenter MD, David O.

    2010-04-01

    Everyone is exposed to electromagnetic fields (EMFs) from electricity (extremely low frequency, ELF), communication frequencies and wireless devices (radiofrequency, RF), as well as naturally occurring EMFs. Concern of health hazards from EMFs has increased as the use of mobile phones and other wireless devices has grown in all segments of the population, especially children. While there has been strong evidence for an association between leukemia and residential or occupational exposure to ELF EMFs for many years, the standards in existence are not sufficiently stringent to protect from an increased risk of cancer. ELF EMFs also increase risk of at least two types of neurodegenerative diseases. For RF EMFs, standards are set at levels designed to avoid tissue heating, in spite of many reports of biological effects at intensities too low to cause significant heating. Recent evidence demonstrates elevations in risk of brain cancer and acoustic neuroma only on the side of the head where individuals used their mobile phone. Individuals who begin exposure at younger ages are more vulnerable. These data indicate that the existing standards for radiofrequency exposure are not adequate. While there are many unanswered questions, the cost of doing nothing may result in an increasing number of people, many of them young, developing these diseases.

  3. Toward a sensible EMF policy: One utility's approach

    SciTech Connect

    Palk, B.V. )

    1991-04-01

    Over the past three years, the Los Angeles Department of Water and Power (LADWP) has developed an open, proactive approach to address the electromagnetic fields (EMF) issue. Many things gave impetus to this approach: the public's increasing concern about possible health effects associated with EMF; litigation and other difficulties utilities experience when attempting to construct electric facilities; and media coverage fueling public concern about the issue. For LADWP, management of this issue involves a communications and a policy development effort, both of them significant. As an integral part of managing this issue, LADWP has taken steps to reduce fields associated with new projects on a case-by-case basis where economically justified, and supported EMF research, including support for a national EMF research program. Also, LADWP continues its full support for and participation in the Electric Power Research Institute's (EPRI) EMF research program. In the discussion here, references to EPRI reports, bulletins, and technical papers have intentionally been excluded, since their inclusion would overwhelm the footnotes to this paper. Finally, LADWP has purposefully sought additional guidance from other individuals and public policy agencies, many of whose works are cited here.

  4. Seattle city light wins EMF lawsuit brought by worker

    SciTech Connect

    Warkentin, D.

    1995-01-01

    Ruling consistent with similar lawsuit outcomes. A Washington state workers` compensation appeals board, in upholding an earlier state agency decision, has ruled that electric and magnetic fields (EMF) did not cause a Seattle City Light worker`s leukemia. The outcome of the case, Pilisuk vs. Seattle City Light, appears to fall in line with decisions in other, similar EMF personal injury lawsuits against electric utilities. Robert Pilisuk, 44, an apprentice and electrician-constructor for Seattle City Light for seven years, died five years ago as a result of acute lymphocytic leukemia. {open_quotes}This was the first thorough examination of the large body of EMF studies by a workers` compensation system,{close_quotes} said Betty Ngan, Seattle assistant city attorney. {open_quotes}The board`s decision is based on the extensive record of testimony taken and an exhaustive review of the studies. The result of this appeal process reflects the state of the science, that there is no proven cause-and -effect relationship between EMF and health effects.{close_quotes}

  5. BOEMRE 2011-09 EFFECTS OF EMFS FROM UNDERSEA POWER CABLES

    E-print Network

    Tricas, Timothy C.

    OCS Study BOEMRE 2011-09 EFFECTS OF EMFS FROM UNDERSEA POWER CABLES ON ELASMOBRANCHS AND OTHER and Enforcement Pacific OCS Region #12;EFFECTS OF EMFS FROM UNDERSEA POWER CABLES ON ELASMOBRANCHS AND OTHER Suggested Citation: Normandeau, Exponent, T. Tricas, and A. Gill. 2011. Effects of EMFs from Undersea Power

  6. A Formal Approach to Three-Way Merging of EMF Models Bernhard Westfechtel

    E-print Network

    Westfechtel, Bernhard

    A Formal Approach to Three-Way Merging of EMF Models Bernhard Westfechtel Applied Computer Science a formal ap- proach to three-way merging of models in the EMF frame- work which may be applied to instances Keywords EMF models, merging 1. INTRODUCTION Model-driven software development strives for reducing

  7. Self-inductance changing current through an inductor gives an emf

    E-print Network

    Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

    #12;Self-inductance ­ changing current through an inductor gives an emf (voltage change) across the inductor denoted by LiN B = Emf for an Inductor dt Lid dt Nd B L )()( -= -=E dt di LL -=E Note the sign of this emf goes against the current change #12;Energy stored in the electric field of a capacitor Energy

  8. ANALYSIS THROUGH REFLECTION: WALKING THE EMF MODEL OF BPEL4WS

    E-print Network

    van Breugel, Franck

    ANALYSIS THROUGH REFLECTION: WALKING THE EMF MODEL OF BPEL4WS Kien Huynh khuynh the Eclipse Mod- elling Framework (EMF) to generate a hierarchy of Java classes and interfaces that represents to be compiled again every time the EMF model of BPEL4WS changes is its main drawback. iv #12;Acknowledgements

  9. A Transformation Engine for EMF Model Transformations Thomas Buchmann, Bernhard Westfechtel and Sabine Winetzhammer

    E-print Network

    Westfechtel, Bernhard

    MODGRAPH A Transformation Engine for EMF Model Transformations Thomas Buchmann, Bernhard.winetzhammer}@uni-bayreuth.de Keywords: Model-Driven Development; Graph Transformations; Code Generation; EMF; Pattern Matching; OCL transfor- mation rule which is compiled into a Java method calling EMF operations. In this way, Mod

  10. Analysis through Reflection Walking the EMF model of BPEL4WS

    E-print Network

    van Breugel, Franck

    Analysis through Reflection Walking the EMF model of BPEL4WS Kien Huynh and Franck van Breugel York framework (EMF) [6] generates a hierarchy of Java classes from the specification of an XML based language. These classes represent the abstract syntax of the lan- guage. In this paper, we will focus on the EMF model

  11. Exposure assessment for power frequency electric and magnetic fields (EMF) and its application to epidemiologic studies

    SciTech Connect

    Bracken, T.D.; Kheifets, L.I.; Sussman, S.S. )

    1993-01-01

    Epidemiologic studies suggesting possible health effects associated with exposure to electric and magnetic fields (EMF) from the transmission, distribution, and use of electricity have motivated increased interest in and attention to EMF exposure assessment. The result has been new instruments, measurement approaches, and exposure models that can improve on what has been a weakness in past epidemiologic studies, namely EMF exposure assessment. This paper presents a status report on EMF exposure assessment that emphasizes the need for incorporation of these advances in future studies. Several factors are identified that make the assignment of contemporary or retrospective EMF exposures potentially more difficult than for other environmental agents. These include: EMF is not generally detectable by humans, exposure scenarios for EMF are generally not memorable, there is no clear mechanism for EMF effects, and the pervasive nature of EMF in an industrialized society makes identification of a low-exposure group difficult. Elements of study design that are impacted by the nature of EMF exposures include: sampling and measurement strategies, summary measures of exposure, and the choice of surrogate and/or models of exposure. Consideration of these exposure assessment issues and incorporation of recent advances can improve the overall quality of epidemiologic studies with an EMF exposure component. 41 refs.

  12. Review of the epidemiologic literature on EMF and Health.

    PubMed Central

    Ahlbom, I C; Cardis, E; Green, A; Linet, M; Savitz, D; Swerdlow, A

    2001-01-01

    Exposures to extremely low-frequency electric and magnetic fields (EMF) emanating from the generation, transmission, and use of electricity are a ubiquitous part of modern life. Concern about potential adverse health effects was initially brought to prominence by an epidemiologic report two decades ago from Denver on childhood cancer. We reviewed the now voluminous epidemiologic literature on EMF and risks of chronic disease and conclude the following: a) The quality of epidemiologic studies on this topic has improved over time and several of the recent studies on childhood leukemia and on cancer associated with occupational exposure are close to the limit of what can realistically be achieved in terms of size of study and methodological rigor. b) Exposure assessment is a particular difficulty of EMF epidemiology, in several respects: i) The exposure is imperceptible, ubiquitous, has multiple sources, and can vary greatly over time and short distances. ii) The exposure period of relevance is before the date at which measurements can realistically be obtained and of unknown duration and induction period. iii) The appropriate exposure metric is not known and there are no biological data from which to impute it. c) In the absence of experimental evidence and given the methodological uncertainties in the epidemiologic literature, there is no chronic disease for which an etiological relation to EMF can be regarded as established. d) There has been a large body of high quality data for childhood cancer, and also for adult leukemia and brain tumor in relation to occupational exposure. Among all the outcomes evaluated in epidemiologic studies of EMF, childhood leukemia in relation to postnatal exposures above 0.4 microT is the one for which there is most evidence of an association. The relative risk has been estimated at 2.0 (95% confidence limit: 1.27-3.13) in a large pooled analysis. This is unlikely to be due to chance but, may be, in part, due to bias. This is difficult to interpret in the absence of a known mechanism or reproducible experimental support. In the large pooled analysis only 0.8% of all children were exposed above 0.4 microT. Further studies need to be designed to test specific hypotheses such as aspects of selection bias or exposure. On the basis of epidemiologic findings, evidence shows an association of amyotrophic lateral sclerosis with occupational EMF exposure although confounding is a potential explanation. Breast cancer, cardiovascular disease, and suicide and depression remain unresolved. PMID:11744509

  13. Cryogenic, Absolute, High Pressure Sensor

    NASA Technical Reports Server (NTRS)

    Chapman, John J. (Inventor); Shams. Qamar A. (Inventor); Powers, William T. (Inventor)

    2001-01-01

    A pressure sensor is provided for cryogenic, high pressure applications. A highly doped silicon piezoresistive pressure sensor is bonded to a silicon substrate in an absolute pressure sensing configuration. The absolute pressure sensor is bonded to an aluminum nitride substrate. Aluminum nitride has appropriate coefficient of thermal expansion for use with highly doped silicon at cryogenic temperatures. A group of sensors, either two sensors on two substrates or four sensors on a single substrate are packaged in a pressure vessel.

  14. Three-phase power factor controller with induced EMF sensing

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (inventor)

    1984-01-01

    A power factor controller for an ac induction motor is provided which is of the type comprising thyristor switches connected in series with the motor, phase detectors for sensing the motor current and voltage and providing an output proportional to the phase difference between the motor voltage and current, and a control circuit, responsive to the output of the phase detector and to a power factor command signal, for controlling switching of the thyristor. The invention involves sensing the induced emf produced by the motor during the time interval when the thyristor is off and for producing a corresponding feedback signal for controlling switching of the thyristor. The sensed emf is also used to enhance soft starting of the motor.

  15. Electric shock and elevated EMF levels due to triplen harmonics

    SciTech Connect

    Tran, T.Q.; Conrad, L.E.; Stallman, B.K.

    1996-04-01

    The increasing use of single phase rectifiers for electric power conversion in residential applications increases harmonic load on utility systems. Many papers have analyzed the effect of these loads on power quality and equipment loadability. However, there are two more critical concerns for harmonic loads served phase to neutral on multi-grounded wye systems. Triplen harmonics, particularly the third, add in the neutral and have little diversity between loads. The higher neutral currents may cause significant problems. Neutral to earth voltages will increase near the substations which could increase stray voltage complaints. The additional neutral current on three phase lines will elevate EMF levels especially in the fringe areas. This paper provides fundamental understanding of triplen harmonic influence on stray voltage and EMF related to multi-grounded wye electric distribution systems.

  16. EPRI EMF Exposure Database: Electrical Workers data set

    SciTech Connect

    Rankin, R.F.; Senior, R.S.; Bracken, T.D.

    1996-10-01

    This document presents the Electric Workers Data Set used for the Assessment of Electromagnetic Fields (EMF) Exposure by Job Title study. Several epidemiologic studies have reported an association between cancer and exposure assessed by job title. This information prompted increased interest in measuring and understanding occupational EMF exposure. This research is part of a broader effort of exposure assessment studies investigating long-term occupational exposure and its temporal variability, the relationships between job title, worker task and worker environment with measured exposure, compliance of worker exposure to proposed or existing exposure limits and identification of sources of occupational exposure. This documentation contains a project synopsis, full descriptions of all data elements, and the format specification and size of each data product.

  17. Emf, maximum power and efficiency of fuel cells

    SciTech Connect

    Gaggioli, R.A.; Dunbar, W.R. )

    1993-06-01

    The ideal voltage of steady-flow fuel cells is usually expressed by Emf = [minus] [Delta]G[degree]/nF where [Delta]G[degree] is the Gibbs free energy of reaction'' for the oxidation of the fuel at the supposed temperature of operation of the cell. Furthermore, the ideal power of the cell is expressed as the product of the fuel flow rate with this emf. Such viewpoints are flawed in several respects. Even if the cell operates isothermally, the use of the conventional [Delta]G[degree] of reaction (a) assumes that the products of reaction leave separately from one another ( and from any unused fuel); and (b) when [Delta]S of reaction is positive, it assumes that a free heat source exists at the operating temperature, whereas if [Delta]S is negative, it neglects the potential power which theoretically could be obtained from the heat released during oxidation. Moreover, (c) the usual cell does not operate isothermally, but (virtually) adiabatically. Comment (a) is often accounted for by employing the Nernst equation to correct for the dilution of reactants and/or products. Nevertheless, comments (b) and (c) remain pertinent. Rather than with emf, the proper starting place is with power output. The ideal power is that which would be obtained if the fuel were oxidized without irreversible entropy generation. Among other factors, this ideal power output depends upon the ratio of oxidant to fuel flow rate (e.g., air-fuel ratio) and the percentage of fuel oxidation. The ideal voltage is deduced from the ideal power. Therefore, (d) ideal power is not equal to the product of emf with current (unless the amount of fuel utilized is infinitesimal). Examples are presented which illustrate such affects and their importance for the evaluation of ideal power and of efficiency.

  18. The process of consensus on EMF: SAB review of the EPA draft document on EMF and cancer

    SciTech Connect

    Wilson, B.W.

    1992-06-01

    The EPA Draft Document on EMF and Cancers grew out of an earlier effort by EPA to track biological effects literature relative to radio-frequency (RF) exposure. Scope of the document was broadened to include extremely low frequency electric and magnetic fields prior to an announcement in 1986 that EPA would formally review the whole area of non-ionizing radiation. An extensive survey of the relevant bioeffects and epidemiologic literature was carried out, and writing on the document began in earnest on the document sometime in 1989. In its draft form, the document reviewed the literature on mechanisms of Interaction between electromagnetic fields and biological tissue, EMF epidemiologic studies, supporting evidence for carcinogenicity and research needs. In the early summer of 1990, a draft of the document was reviewed by some 22 individuals within the EPA and other government agencies. It was also sent out for external review to an additional 9 qualified scientists who had worked in the area and were familiar with EMF-related literature in epidemiology, biology, and physics. Many of the comments sent to EPA from this first review, prior to release of the draft for public comment, were strikingly similar to those resulting from the second (public) review process. Thus, it appears that much of the controversy that was later associated with the document could have been avoided had the authors been diligent in following the recommendations of the initial set of reviewers.

  19. Rate of rotation measurement using back-EMFS associated with windings of a brushless DC motor

    NASA Technical Reports Server (NTRS)

    Howard, David E. (Inventor)

    2000-01-01

    A system and method are provided for measuring rate of rotation. A brushless DC motor is rotated and produces a back electromagnetic force (emf) on each winding thereof. Each winding's back-emf is integrated and multiplied by the back-emf associated with an adjacent winding. The multiplied outputs associated with each winding are combined to produce a directionally sensitive DC output proportional only to the rate of rotation of the motor's shaft.

  20. Overview of EMF 22 U.S. Transition Scenarios

    SciTech Connect

    Fawcett, Allen A.; Calvin, Katherine V.; De La Chesnaye, Francisco; Reilly, J. M.; Weyant, John

    2010-01-01

    The Energy Modeling Forum 22 study included a set of U.S. transition scenarios designed to bracket a range of potential U.S. climate policy goals. Models from the six teams that participated in this part of the study include models that have been prominently involved in analyzing proposed U.S. climate legislation, as well as models that have been involved in the Climate Change Science Program and other parts of this EMF 22 study. This paper presents an overview of the results from the U.S. transition scenarios, and provides insights into the comparison of results from the participating models.

  1. Environmental Field Surveys, EMF Rapid Program, Engineering Project No.3

    SciTech Connect

    Enertech Consultants

    1996-04-01

    The EMF Research and Public Information Dissemination Program (RAPID) includes several engineering research in the area of exposure assessment and source characterization. RAPID engineering project No. 3: ''Environmental Field Surveys'' was performed to obtain information on the levels and characteristics of different environments, for which only limited data were available, especially in comparison to magnetic field data for the residential environment and for electric utility facilities, such as power lines and substations. This project was also to provide information on the contribution of various field sources in the surveyed environments. Magnetic field surveys were performed at four sites for each of five environments: schools, hospitals, office buildings, machine shops, and grocery stores. Of the twenty sites surveyed, 11 were located in the San Francisco Bay Area and 9 in Massachusetts. The surveys used a protocol based on magnetic field measurements and observation of activity patterns, designed to provide estimates of magnetic field exposure by type of people and by type of sources. The magnetic field surveys conducted by this project produced a large amount of data which will form a part of the EMF measurement database Field and exposure data were obtained separately for ''area exposure'' and ''at exposure points''. An exposure point is a location where persons engage in fixed, site specific activities near a local source that creates a significant increase in the area field. The area field is produced by ''area sources'', whose location and field distribution is in general not related to the location of the people in the area.

  2. The EMF dilemma: Decision-making amid scientific uncertainty

    SciTech Connect

    Sage, C. )

    1991-04-01

    In 1989, residents of Monticito, CA about 90 mi NW of Los Angeles called to the attention of local school and county health officials a leukemia cluster observed in children in the area. In this cluster, the rate of cancer in children appeared to be five times the expected rate. Montecito Union School is bisected by 66-kV power lines, as they come out into the community from a substation directly adjacent to the school. The lines pass within 15 feet of the north side of Howard School. After the State Department of Health identified this as a legitimate cancer cluster, the state responded by taking EMF readings in September 1989 on and near Montecito Union School and produced a report in December of that year. In the weeks following the December 1989 report, concern built in the community over perceived weaknesses in the state's methodology. Doubt was cast over the state's willingness to perform a thorough investigation. The cognizant utility, Southern California Edison, was involved early in the information sharing. The author discusses the mediated negotiation, and recommends that utility planners be candid, provide honest answers, work openly and aggressively with communities, and make EMF information easily accessible.

  3. Discussion of an EMF (electric and magnetic field) protocol

    SciTech Connect

    Afifi, A.A.; Banks, R.S.; Kheifets, L.I.; Newman, B. Associates, Inc., Minneapolis, MN )

    1990-07-01

    In 1989, three collaborating cancer research agencies initiated large-scale case-control studies of the postulated association between residential exposure to 50/60-Hz electric and magnetic fields and the induction of childhood leukemia. To facilitate design of the exposure assessment component of these studies, the Electric Power Research Institute sponsored a two-day workshop on February 6--8, 1989. The workshop's objective was to develop a detailed state-of-the science'' protocol for direct and/or surrogate measurements of a subject's EMF exposure history. Emphasis was placed on the difficulties inherent in measuring the exposure of small children. Attendees were divided into three working groups, addressing the following questions, respectively: How can historical exposure best be assessed; what should be measured outdoors; and what should be measured indoors Consensus on a single protocol was not found to be possible, given the state of knowledge about EMF exposure and the pathophysiology of childhood leukemia. However, the discussion produced a comprehensive analysis of the issues involved in addressing the crucial questions of who and what should be measured, and when, where and how these measurements should take place. In particular, discussion focused on: personal monitoring versus area measurements; exposure metrics; relevant time periods over the subjects life for measurement; location and duration of measurements; and protocol development considerations. Attendees expressed strong interest in another, similar workshop sometime in the future. 1 tab.

  4. EMF RAPID Program research agenda and communication plan

    SciTech Connect

    Not Available

    1994-05-01

    The driving force behind the Electric and Magnetic Fields (EMF) Research and Public Information Dissemination (RAPID) Program, established by Section 2118 of the Energy Policy Act of 1992, is the ``sense of the Congress that remedial action taken by the Government on electric and magnetic fields, if and as necessary, should be based on, and consistent with, scientifically valid research...`` Specifically, the legislation requires the development of a comprehensive program to: determine whether or not exposure to electric and magnetic fields produced by the generation, transmission, and use of electric energy affects human health; carry out research, development, and demonstration with respect to technologies to mitigate any adverse human health effects; and provide for the collection, compilation, publication, and dissemination of scientifically valid information to the public on the following subjects: (a) possible human health effects of electric and magnetic fields; (b) the types and extent of human exposure to electric and magnetic fields in various occupational and residential settings; (c) technologies to measure and characterize electric and magnetic fields; and (d) methods to assess and manage exposure to electric and magnetic fields. The Department of Energy (DOE) is responsible for the overall administration of the 5-year, and $65 million EMF RAPID Program. The program will be jointly funded by both Federal non-Federal sources with non-Federal contributions accounting for at least 50% of the total funding.

  5. Teaching Absolute Value Meaningfully

    ERIC Educational Resources Information Center

    Wade, Angela

    2012-01-01

    What is the meaning of absolute value? And why do teachers teach students how to solve absolute value equations? Absolute value is a concept introduced in first-year algebra and then reinforced in later courses. Various authors have suggested instructional methods for teaching absolute value to high school students (Wei 2005; Stallings-Roberts…

  6. EMF1 and PRC2 Cooperate to Repress Key Regulators of Arabidopsis Development

    E-print Network

    G mechanism is unclear. To study the EMF1 functions and its mechanism of action, we performed genome that EMF1 represses gene activities via diverse mechanisms and plays a novel role in the PcG mechanism and docks on nucleosomes modified by PRC2, inhibits transcription and blocks remodeling of the target

  7. Rubber and alumina gaskets retain vacuum seal in high temperature EMF cell

    NASA Technical Reports Server (NTRS)

    Hesson, J. C.

    1966-01-01

    Silicone rubber gasket and an alumina gasket retain a vacuum inside a high temperature EMF cell in which higher and lower density liquid metal electrodes are separated by an intermediate density fused salt electrolyte. This innovation is in use on a sodium bismuth regenerable EMF cell in which the fused salts and metals are at about 500 deg to 600 deg C.

  8. Absolute negative mobility of interacting Brownian particles

    NASA Astrophysics Data System (ADS)

    Ou, Ya-li; Hu, Cai-tian; Wu, Jian-chun; Ai, Bao-quan

    2015-12-01

    Transport of interacting Brownian particles in a periodic potential is investigated in the presence of an ac force and a dc force. From Brownian dynamic simulations, we find that both the interaction between particles and the thermal fluctuations play key roles in the absolute negative mobility (the particle noisily moves backwards against a small constant bias). When no the interaction acts, there is only one region where the absolute negative mobility occurs. In the presence of the interaction, the absolute negative mobility may appear in multiple regions. The weak interaction can be helpful for the absolute negative mobility, while the strong interaction has a destructive impact on it.

  9. Experimental model for ELF-EMF exposure: Concern for human health

    PubMed Central

    D’Angelo, C.; Costantini, E.; Kamal, M.A.; Reale, M.

    2014-01-01

    Low frequency (LF) electromagnetic fields (EMFs) are abundantly present in modern society and in the last 20 years the interest about the possible effect of extremely low frequency (ELF) EMFs on human health has increased progressively. Epidemiological studies, designed to verify whether EMF exposure may be a potential risk factor for health, have led to controversial results. The possible association between EMFs and an increased incidence of childhood leukemia, brain tumors or neurodegenerative diseases was not fully elucidated. On the other hand, EMFs are widely used, in neurology, psychiatry, rheumatology, orthopedics and dermatology, both in diagnosis and in therapy. In vitro studies may help to evaluate the mechanism by which LF-EMFs affect biological systems. Invitro model of wound healing used keratinocytes (HaCaT), neuroblastoma cell line (SH-SY5Y) as a model for analysis of differentiation, metabolism and functions related to neurodegenerative processes, and monocytic cell line (THP-1) was used as a model for inflammation and cytokines production, while leukemic cell line (K562) was used as a model for hematopoietic differentiation. MCP-1, a chemokine that regulates the migration and infiltration of memory T cells, natural killer (NK), monocytes and epithelial cells, has been demonstrated to be induced and involved in various diseases. Since, varying the parameters of EMFs different effects may be observed, we have studied MCP-1 expression in HaCaT, SH-SY5Y, THP-1 and K562 exposed to a sinusoidal EMF at 50 Hz frequency with a flux density of 1 mT (rms). Our preliminary results showed that EMF-exposure differently modifies the expression of MCP-1 in different cell types. Thus, the MCP-1 expression needs to be better determined, with additional studies, with different parameters and times of exposure to ELF-EMF. PMID:25561888

  10. Sources of EMF in Near Earth and Planetary Environments

    NASA Astrophysics Data System (ADS)

    McCanney, J. M.

    2008-05-01

    The realization that extensive electrical activates occur in and above the troposphere, extending to the ionosphere and ultimately coupling to the magnetosphere have raised the theoretical and experimental questions regarding the sources of EMF which create the observed effects. The current work has identified 17 Local Electrical Batteries (LEBs), which provide the electrical EMF that can be linked to the observed effects of Sprites, Elves, etc. and which additionally are shown to directly power the troposphere storm systems and counter-rotating jet streams, rotating in the easterly direction in the northern and southern latitudes and westerly near the equator. The high latitude easterly flowing jet streams contain positively charged ions in the driving layers of the ionosphere, whereas the equatorial westerly flowing jet streams contain electrons. The flow of energy concentrates near the equatorial regions (low latitudes) for a number of theoretical reasons. Energy flows also occur in the vortex regions (corresponding to troposphere low pressure cells) as the easterly flowing ionosphere high latitude belts interact with the equatorial westerly moving streams. These flows couple to both the terrestrial and external ring current magnetic fields. The path of the sources of EMF can be followed from the passing solar wind through "tunnels" that end in electrical currents that pass into the atmosphere via the ionosphere to storm cloud systems in the lower atmosphere. These are the sources of electrical energy that power the severe lower atmospheric storm systems such as westerly moving hurricanes at low latitudes and associated tornadoes. The model for these storm systems is included. The connection is made theoretically with the solar wind that drives the 17 identified LEBs. The ultimate source of driving energy is the result of an excess current of protons in the solar wind, which creates an overall capacitor with inherent non-uniform electric field surrounding the Sun. On a local scale the voltage gradients are quite low, but all objects in this solar capacitor, including the planets and their moon systems, discharge this capacitor over extensive trans-planetary distances, thus creating excessive current flows, which also respond to CMEs and solar flares. The key to understanding reactions to non-uniform electric fields in the LEB environment is based on the fact that planetary Debye shielding takes on a new form, which is extended from that of the neutral environment typically considered in previous theoretical models. An attempt is made to solve the fundamental problem of the source of energy that drives these systems. Previous meteorological models considered that the energy sources for lightning and other energetic phenomenon came from within the storm systems. The current work shows that the original sources of EMF are actually in the passing solar wind and the non-uniform electric field created by an excess current of protons in the solar wind. The effects of moons and their positions relative to the planet and solar wind, as well as multiple planetary electrical alignments, are shown to contribute to the overall discharge phenomenon. A connection is made between these energy sources and cyclonic storms, earthquakes and volcanic "trigger" mechanisms. Additionally theoretical modeling shows that infrared signatures of military targets in the plasma layers surrounding earth vary during solar storm activity.

  11. Sharpening the focus in EMF research. [Electric and Magnetic Fields

    SciTech Connect

    Moore, T. )

    1992-03-01

    Research results have yet to settle whether or not exposure to magnetic fields can adversely affect human health, but recent studies have provided strong pointers to several fertile areas of inquiry. EPRI is planning new studies that will dig deeper into the mysteries of these key focus areas, including questions about what wire code classifications really represent as indicators of residential magnetic field exposure and whether they are appropriate surrogates for actual exposure measurements. Other questions surround the hypothesis that magnetic fields could suppress production of the hormone melatonin, representing a possible mechanism of biological interaction. In addition to health studies, EPRI is continuing work in other parts of its comprehensive EMF research program, which includes identification of significant field sources and investigation of potential field management methods.

  12. Differentiation of K562 cells under ELF-EMF applied at different time courses.

    PubMed

    Ay?e, Inhan-Garip; Zafer, Akan; Sule, Oncul; I?il, I?al-Turgut; Kalkan, Tunaya

    2010-08-01

    The time-course of ELF-EMF application to biological systems is thought to be an important parameter determining the physiological outcome. This study investigated the effect of ELF-EMF on the differentiation of K562 cells at different time courses. ELF-EMF (50 Hz, 5 mT, 1 h) was applied at two different time-courses; first at the onset of hemin induction for 1 h, and second, daily 1 h for four days. While single exposure to ELF-EMF resulted in a decrease in differentiation, ELF-EMF applied everyday for 1 h caused an increase in differentiation. The effect of co-stressors, magnesium, and heat-shock was also determined and similar results were obtained. ELF-EMF increased ROS levels in K562 cells not treated with hemin, however did not change ROS levels of hemin treated cells indicating that ROS was not the cause. Overall, these results imply that the time-course of application is an important parameter determining the physiological response of cells to ELF-EMF. PMID:20707646

  13. Idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF): A systematic review of identifying criteria

    PubMed Central

    2012-01-01

    Background Idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) remains a complex and unclear phenomenon, often characterized by the report of various, non-specific physical symptoms (NSPS) when an EMF source is present or perceived by the individual. The lack of validated criteria for defining and assessing IEI-EMF affects the quality of the relevant research, hindering not only the comparison or integration of study findings, but also the identification and management of patients by health care providers. The objective of this review was to evaluate and summarize the criteria that previous studies employed to identify IEI-EMF participants. Methods An extensive literature search was performed for studies published up to June 2011. We searched EMBASE, Medline, Psychinfo, Scopus and Web of Science. Additionally, citation analyses were performed for key papers, reference sections of relevant papers were searched, conference proceedings were examined and a literature database held by the Mobile Phones Research Unit of King’s College London was reviewed. Results Sixty-three studies were included. “Hypersensitivity to EMF” was the most frequently used descriptive term. Despite heterogeneity, the criteria predominantly used to identify IEI-EMF individuals were: 1. Self-report of being (hyper)sensitive to EMF. 2. Attribution of NSPS to at least one EMF source. 3. Absence of medical or psychiatric/psychological disorder capable of accounting for these symptoms 4. Symptoms should occur soon (up to 24?hours) after the individual perceives an exposure source or exposed area. (Hyper)sensitivity to EMF was either generalized (attribution to various EMF sources) or source-specific. Experimental studies used a larger number of criteria than those of observational design and performed more frequently a medical examination or interview as prerequisite for inclusion. Conclusions Considerable heterogeneity exists in the criteria used by the researchers to identify IEI-EMF, due to explicit differences in their conceptual frameworks. Further work is required to produce consensus criteria not only for research purposes but also for use in clinical practice. This could be achieved by the development of an international protocol enabling a clearly defined case definition for IEI-EMF and a validated screening tool, with active involvement of medical practitioners. PMID:22883305

  14. EMF and transmission line siting: The emerging state regulatory framework and implications for utilities

    SciTech Connect

    Gulliver, J.W.; Vito, C.C.

    1993-12-31

    One of the thorniest policy issues facing electric utilities and regulators in the potential public health risk of electromagnetic fields (EMF). EMF has been the focus of numerous biological, epidemiological, and toxicological studies, the results of which have been inconclusive and sometimes contraditory. Collectively the studies seem to indicate that EMF has demonstrable biological effects, but the extent to which these effects adversely impact human health remains unclear. This article summarizes the response of the 19 states which have, either through their public utility commissions, special task forces, legislatures, or other agencies, addressed the EMF issue. Responses covered include the following: prudent avoidance; construction moratoria; field strength standards; maintaining status quo; and the response of the utilities.

  15. Modelling indoor electromagnetic fields (EMF) from mobile phone base stations for epidemiological studies.

    PubMed

    Beekhuizen, J; Vermeulen, R; van Eijsden, M; van Strien, R; Bürgi, A; Loomans, E; Guxens, M; Kromhout, H; Huss, A

    2014-06-01

    Radio frequency electromagnetic fields (RF-EMF) from mobile phone base stations can be reliably modelled for outdoor locations, using 3D radio wave propagation models that consider antenna characteristics and building geometry. For exposure assessment in epidemiological studies, however, it is especially important to determine indoor exposure levels as people spend most of their time indoors. We assessed the accuracy of indoor RF-EMF model predictions, and whether information on building characteristics could increase model accuracy. We performed 15-minute spot measurements in 263 rooms in 101 primary schools and 30 private homes in Amsterdam, the Netherlands. At each measurement location, we collected information on building characteristics that can affect indoor exposure to RF-EMF, namely glazing and wall and window frame materials. Next, we modelled RF-EMF at the measurement locations with the 3D radio wave propagation model NISMap. We compared model predictions with measured values to evaluate model performance, and explored if building characteristics modified the association between modelled and measured RF-EMF using a mixed effect model. We found a Spearman correlation of 0.73 between modelled and measured total downlink RF-EMF from base stations. The average modelled and measured RF-EMF were 0.053 and 0.041mW/m(2), respectively, and the precision (standard deviation of the differences between predicted and measured values) was 0.184mW/m(2). Incorporating information on building characteristics did not improve model predictions. Although there is exposure misclassification, we conclude that it is feasible to reliably rank indoor RF-EMF from mobile phone base stations for epidemiological studies. PMID:24632329

  16. Nuclear Energy Response in the EMF27 Study

    SciTech Connect

    Kim, Son H.; Wada, Kenichi; Kurosawa, Atsushi; Roberts, Matthew

    2014-03-25

    The nuclear energy response for mitigating global climate change across eighteen participating models of the EMF27 study is investigated. Diverse perspectives on the future role of nuclear power in the global energy system are evident in the broad range of nuclear power contributions from participating models of the study. In the Baseline scenario without climate policy, nuclear electricity generation and shares span 0 – 66 EJ/ year and 0 - 25% in 2100 for all models, with a median nuclear electricity generation of 39 EJ/year (1,389 GWe at 90% capacity factor) and median share of 9%. The role of nuclear energy increased under the climate policy scenarios. The median of nuclear energy use across all models doubled in the 450 ppm CO2e scenario with a nuclear electricity generation of 67 EJ/year (2,352 GWe at 90% capacity factor) and share of 17% in 2100. The broad range of nuclear electricity generation (11 – 214 EJ/year) and shares (2 - 38%) in 2100 of the 450 ppm CO2e scenario reflect differences in the technology choice behavior, technology assumptions and competitiveness of low carbon technologies. Greater clarification of nuclear fuel cycle issues and risk factors associated with nuclear energy use are necessary for understanding the nuclear deployment constraints imposed in models and for improving the assessment of the nuclear energy potential in addressing climate change.

  17. EMF 7 model comparisons: key relationships and parameters

    SciTech Connect

    Hickman, B.G.

    1983-12-01

    A simplified textbook model of aggregate demand and supply interprets the similarities and differences in the price and income responses of the various EMF 7 models to oil and policy shocks. The simplified model is a marriage of Hicks' classic IS-LM formulation of the Keynesian theory of effective demand with a rudimentary model of aggregate supply, combining a structural Phillips curve for wage determination and a markup theory of price determination. The reduced-form income equation from the fix-price IS-LM model is used to define an aggregate demand (AD) locus in P-Y space, showing alternative pairs of the implicit GNP deflator and real GNP which would simultaneously satisfy the saving-investment identity and the condition for money market equilibrium. An aggregate supply (AS) schedule is derived by a similar reduction of relations between output and labor demand, unemployment and wage inflation, and the wage-price-productivity nexus governing markup pricing. Given a particular econometric model it is possible to derive IS and LM curves algebraically. The resulting locuses would show alternative combinations of interest rate and real income which equilibrate real income identity on the IS side and the demand and supply of money on the LM side. By further substitution the reduced form fix-price income relation could be obtained for direct quantification of the AD locus. The AS schedule is obtainable by algebraic reduction of the structural supply side equations.

  18. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K. (Pleasanton, CA); Snyderman, Neal J. (Berkeley, CA); Rowland, Mark S. (Alamo, CA)

    2010-07-13

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  19. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K. (Pleasanton, CA); Snyderman, Neal J. (Berkeley, CA); Rowland, Mark S. (Alamo, CA)

    2012-05-15

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  20. Investigation Of The EMF Versus State Of Charge Behavior Of Individual Electrodes In New And Cycled Sony 18650 HC Cells

    NASA Astrophysics Data System (ADS)

    Dudley, G.; Mattle, T.

    2011-10-01

    Individual electrode EMFs of new and cycled Sony 18650 HC cells have been measured with the help of a lithium reference electrode inserted into complete cells. Results have revealed the relative contribution of each electrode to voltage hysteresis (the difference in cell EMF between charge and discharge at the same state of charge).They have also shown changes to the shape of the positive electrode EMF versus state of charge in cycled compared to beginning of life cells.

  1. Recommendations for Guidelines for EMF Personal Exposure Measurements, Rapid Project #4

    SciTech Connect

    T. Dan Bracken, Inc.

    1997-08-01

    The purpose of developing guidelines for electric and magnetic field (EMF) personal exposure measurements (lF'EM) is to ensure reliable and comparable data across I?EM studies. Study techniques may vary due to different populations or objectives, but the resulting data should be consistently reported and comparable, to the extent possible. Any guideline must allow creativity by the research-oriented investigator and provide specific guidance to industrial hygienists or other results-oriented investigators, requiring a standard protocol. Recognizing measurement studies with different purposes is an important aspect of these recommendations. The guidelines presented here intend to produce comparable data across studies while remaining flexible. The recommendations for designing and implementing an EMF PEM program describe a three-stage process. The first step is to clearly state the purpose of the PEM program. The next stage addresses the fundamental elements of an EMF PEM study, including an assessment of the scientific and organizational resources that will be required. This process is codified in a written study plan. These stages are described in 1 Section 5 of this report. The third stage of a PEM study involves the design, implementation and documentation of specific procedures and protocols fo~ sampling strategies, selection of measurement parameters; instrumentation, measurement and data collection, data management, data analysis, quality assurance, uncertainty evaluation, and archiving the study methods and results. The methods for designing these elements of an EMF PEM study are described in Section 6: Specific Guidelines for EMF I?EM Study Design.

  2. Modulation of radical pairs dynamics immersed in an ELF-EMF: The effect on hepatocarcinogenesis

    NASA Astrophysics Data System (ADS)

    López-Riquelme, G. O.; López-Sandoval, E.; Vera-Aguilar, E.; Godina-Nava, J. J.

    2015-01-01

    The most suitable mechanism of action of electromagnetic fields (EMF) on biological systems is the effect on the radical pair (RP) recombination through the Zeeman effect and hyperfine interaction, which changes the rate of reactions or the product distribution. Enzyme reactions with RP intermediates can be altered by EMF, like those catalyzed by cytochrome P450 enzymes (CYP450), a heme-thiolate family protein that detoxifies xenobiotics and involved in chemical carcinogenesis. CYP450 activate chemical carcinogens producing an enormous amount of free radicals, which damage the DNA resulting in the malignant transformation of cells. During the activation, CYP450 produce spin-correlated RP intermediates that can either go to recombination or to continue the catalytic process. As CYP450 are electron carrier proteins, it is possible that RP intermediates may be affected by EMF. It was previously found that periodic treatment with extremely low frequency electromagnetic fields (ELF-EMF) inhibits more than 50% the number and area of preneoplastic lesions in rats with chemically induced hepatocarcinogenesis through reduction of cell proliferation. In this work, we developed a quantum mechanical model based on RP mechanism in order to explain the experimental effects of ELF-EMF on the free radicals produced in the early stages of chemical carcinogenesis.

  3. Effect of Extremely Low Frequency Electromagnetic Fields (EMF) on Phospholipase Activity in the Cultured Cells

    PubMed Central

    Song, Ho Sun; Kim, Hee Rae; Ko, Myoung Soo; Jeong, Jae Min; Kim, Yong Ho; Kim, Myung Cheul; Hwang, Yeon Hee; Sohn, Uy Dong; Gimm, Yoon-Myoung; Myung, Sung Ho

    2010-01-01

    This study was conducted to investigate the effects of extremely low frequency electromagnetic fields (EMF) on signal pathway in plasma membrane of cultured cells (RAW 264.7 cells and RBL 2H3 cells), by measuring the activity of phospholipase A2 (PLA2), phospholipase C (PLC) and phospholipase D (PLD). The cells were exposed to the EMF (60 Hz, 0.1 or 1 mT) for 4 or 16 h. The basal and 0.5 µM melittin-induced arachidonic acid release was not affected by EMF in both cells. In cell-free PLA2 assay, we failed to observe the change of cPLA2 and sPLA2 activity. Also both PLC and PLD activities did not show any change in the two cell lines exposed to EMF. This study suggests that the exposure condition of EMF (60 Hz, 0.1 or 1 mT) which is 2.4 fold higher than the limit of occupational exposure does not induce phospholipases-associated signal pathway in RAW 264.7 cells and RBL 2H3 cells. PMID:21311685

  4. Absolute magnitudes of trans-neptunian objects

    NASA Astrophysics Data System (ADS)

    Duffard, R.; Alvarez-candal, A.; Pinilla-Alonso, N.; Ortiz, J. L.; Morales, N.; Santos-Sanz, P.; Thirouin, A.

    2015-10-01

    Accurate measurements of diameters of trans- Neptunian objects are extremely complicated to obtain. Radiomatric techniques applied to thermal measurements can provide good results, but precise absolute magnitudes are needed to constrain diameters and albedos. Our objective is to measure accurate absolute magnitudes for a sample of trans- Neptunian objects, many of which have been observed, and modelled, by the "TNOs are cool" team, one of Herschel Space Observatory key projects grantes with ~ 400 hours of observing time. We observed 56 objects in filters V and R, if possible. These data, along with data available in the literature, was used to obtain phase curves and to measure absolute magnitudes by assuming a linear trend of the phase curves and considering magnitude variability due to rotational light-curve. In total we obtained 234 new magnitudes for the 56 objects, 6 of them with no reported previous measurements. Including the data from the literature we report a total of 109 absolute magnitudes.

  5. Electromagnetic fields and the public: EMF standards and estimation of risk

    NASA Astrophysics Data System (ADS)

    Grigoriev, Yury

    2010-04-01

    Mobile communications are a relatively new and additional source of electromagnetic exposure for the population. Standard daily mobile-phone use is known to increase RF-EMF (radiofrequency electromagnetic field) exposure to the brains of users of all ages, whilst mobile-phone base stations, and base station units for cordless phones, can regularly increase the exposures of large numbers of the population to RF-EMF radiation in everyday life. The need to determine appropriate standards stipulating the maximum acceptable short-term and long-term RF-EMF levels encountered by the public, and set such levels as general guidelines, is of great importance in order to help preserve the general public's health and that of the next generation of humanity.

  6. The Proof that the Standard Transformations of E and B are not the Lorentz Transformations. Application to Motional EMF

    E-print Network

    Tomislav Ivezic

    2004-11-18

    In this paper it is proved by using the Clifford algebra formalism that the standard transformations (ST) of the three-dimensional (3D) vectors of the electric and magnetic fields E and B are not the Lorentz transformations (LT) of well-defined quantities from the 4D spacetime. This difference between the ST and the LT is obtained regardless of the used algebraic objects (1-vectors or bivectors) for the representation of the electric and magnetic fields in the usual observer dependent decompositions of F. The LT correctly transform the whole 4D quantity, e.g., E_{f}=F\\cdot \\gamma_{0}, whereas the ST are the result of the application of the LT only to the part of E_{f}, i.e., to F, but leaving gamma_{0} unchanged. The new decompositions of F in terms of 4D quantities that are defined without reference frames, i.e., the absolute quantities, are introduced and discussed. It is shown that the LT of the 4D quantities representing electric and magnetic fields correctly describe the motional electromotive force (emf) for all relatively moving inertial observers, whereas it is not the case with the ST of the 3D E and B.

  7. The Proof that the Standard Transformations of E and B are not the Lorentz Transformations. Application to Motional EMF

    E-print Network

    Ivezic, T

    2004-01-01

    In this paper it is proved by using the Clifford algebra formalism that the standard transformations (ST) of the three-dimensional (3D) vectors of the electric and magnetic fields E and B are not the Lorentz transformations (LT) of well-defined quantities from the 4D spacetime. This difference between the ST and the LT is obtained regardless of the used algebraic objects (1-vectors or bivectors) for the representation of the electric and magnetic fields in the usual observer dependent decompositions of F. The LT correctly transform the whole 4D quantity, e.g., E_{f}=F\\cdot \\gamma_{0}, whereas the ST are the result of the application of the LT only to the part of E_{f}, i.e., to F, but leaving gamma_{0} unchanged. The new decompositions of F in terms of 4D quantities that are defined without reference frames, i.e., the absolute quantities, are introduced and discussed. It is shown that the LT of the 4D quantities representing electric and magnetic fields correctly describe the motional electromotive force (emf...

  8. Melatonin and puberty in female lambs exposed to EMF: A replicate study

    SciTech Connect

    Lee, J.M. Jr.; Stormshak, F.; Thompson, J.M.; Hess, D.L.; Foster, D.L.

    1995-06-01

    In an earlier study, the authors found no effects of 60 Hz electric and magnetic fields (EMF) from a 500 kV transmission line on serum melatonin patterns or on puberty in ten female Suffolk lambs (Ovis aries). The authors conducted a larger replicate study of 15 lambs exposed to a mean electric field of 6.3 kV/m and a mean magnetic field of 3.77 {mu}T and 15 controls exposed to EMF two orders of magnitude weaker than in the line area. The replicate produced essentially the same results as their previous study.

  9. Induced Electromotive Force (EMF) Profile in a Circular Loop Passing a Limited Rectangular Area with Perpendicular Uniform Constant Magnetic Field

    E-print Network

    Viridi, Sparisoma; Khairurrijal,

    2012-01-01

    Profile of induced eletromotive force (EMF) for a circular loop (CL) entering and leaving a limited rectangular area which has perpendicular uniform magnetic field is reported in this work. The influence of parameters of the sytem to the induced EMF profile is discussed.

  10. Comparison of a triaxial fluxgate magnetometer and Toftness sensometer for body surface EMF measurement

    PubMed Central

    Zhang, John; Toftness, Dave; Snyder, Brian; Nosco, Dennis; Balcavage, Walter; Nindl, Gabi

    2004-01-01

    Introduction The use of magnetic fields to treat disease has intrigued mankind since the time of the ancient Greeks. More recently it has been shown that electromagnetic field (EMF) treatment aids bone healing, and repetitive transcranial magnetic stimulation (rTMS) appears to be beneficial in treating schizophrenia and depression. Since external EMFs influence internal body processes, we hypothesized that measurement of body surface EMFs might be used to detect disease states and direct the course of subsequent therapy. However, measurement of minute body surface EMFs requires use of a sensitive and well documented magnetometer. In this study we evaluated the sensitivity and frequency response of a fluxgate magnetometer with a triaxial probe for use in detecting body surface EMF and we compared the magnetometer readings with a signal from a Toftness Sensometer, operated by an experienced clinician, in the laboratory and in a clinical setting. Methods A Peavy Audio Amplifier and variable power output Telulex signal generator were used to develop 50 ?T EMFs in a three coil Merritt coil system. A calibrated magnetometer was used to set a 60 Hz 50 ?T field in the coil and an ammeter was used to measure the current required to develop the 50 ?T field. At frequencies other than 60 Hz, the field strength was maintained at 50 ?T by adjusting the Telulex signal output to keep the current constant. The field generated was monitored using a 10 turn coil connected to an oscilloscope. The oscilloscope reading indicated that the field strength was the same at all frequencies tested. To determine if there was a correspondence between the signals detected by a fluxgate magnetometer (FGM1) and the Toftness Sensometer both devices were placed in the Merritt coil and readings were recorded from the FGM1 and compared with the ability of a highly experienced Toftness operator to detect the 50 ?T field. Subsequently, in a clinical setting, FGM1 readings made by an FGM1 technician and Sensometer readings were made by 4 Toftness Sensometer operators, having various degrees of experience with this device. Each examiner obtained instrument readings from 5 different volunteers in separate chiropractic adjusting rooms. Additionally, one of the Toftness Sensometers was equipped with an integrated fluxgate magnetometer (FGM2) and this magnetometer was used to obtain a second set of EMF readings in the clinical setting. Results The triaxial fluxgate magnetometer was determined to be moderately responsive to changes in magnetic field frequency below 10 Hz. At frequencies above 10 Hz the readings corresponded to that of the ambient static geofield. The practitioner operating the Toftness Sensometer was unable to detect magnetic fields at high frequencies (above 10 Hz) even at very high EMFs. The fluxgate magnetometer was shown to be essentially a DC/static magnetic field detector and like all such devices it has a limited frequency range with some low level of sensitivity at very low field frequencies. The interexaminer reliability of four Toftness practitioners using the Sensometer on 5 patients showed low to moderate correlation. Conclusions The fluxgate magnetometer although highly sensitive to static (DC) EMFs has only limited sensitivity to EMFs in the range of 1 to 10 Hz and is very insensitive to frequencies above 10 Hz. In laboratory comparisons of the Sensometer and the fluxgate magnetometer there was an occasional correspondence between the two instruments in detecting magnetic fields within the Merritt coil but these occasions were not reproducible. In the clinical studies there was low to moderate agreement between the clinicians using the Sensometer to diagnosing spinal conditions and there was little if any agreement between the Sensometer and the fluxgate magnetometer in detecting EMFs emanating from the volunteers body surface. PMID:17549105

  11. Relation between surface adsorption states and emf in a solid electrolyte concentration cell during carbon monoxide oxidation on platinum studied by local current measurement

    SciTech Connect

    Okamoto, H.; Kawamura, G.; Kudo, T.

    1984-04-01

    The importance of measuring adsorption during surface catalysis has been emphasized often. This is true for the oxidation of carbon monoxide on a platinum surface. Surface adsorption states during the reaction under steady states can be learned from electromotive force (emf) measurement with appropriate assumptions. Two mechanisms for emf generation have been proposed, one is that only oxygen activity generates emf, the other is that both oxygen and CO adsorption generates emf.

  12. Computing Solar Absolute Fluxes

    E-print Network

    Carlos Allende Prieto

    2007-09-14

    Computed color indices and spectral shapes for individual stars are routinely compared with observations for essentially all spectral types, but absolute fluxes are rarely tested. We can confront observed irradiances with the predictions from model atmospheres for a few stars with accurate angular diameter measurements, notably the Sun. Previous calculations have been hampered by inconsistencies and the use of outdated atomic data and abundances. I provide here a progress report on our current efforts to compute absolute fluxes for solar model photospheres. Uncertainties in the solar composition constitute a significant source of error in computing solar radiative fluxes.

  13. The absolute path command

    Energy Science and Technology Software Center (ESTSC)

    2012-05-11

    The ap command traveres all symlinks in a given file, directory, or executable name to identify the final absolute path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it canmore »provide the absolute path to a relative directory from the current working directory.« less

  14. SCHEME FOR INCORPORATING DC MAGNETIC FIELDS INTO EPIDEMIOLOGICAL STUDIES OF EMF EXPOSURE

    EPA Science Inventory

    Experimental data on calcium-ion release in chicken brain tissue suggest that biological effects of electric and magnetic fields (EMFs) are concentrated at certain combinations of DC magnetic field strength and "critical" AC magnetic field frequencies. e hypothesize that "active"...

  15. Universal "Imaginary Closed Circuit Method" and Formula for Determination of Direction of Induced EMF/Current

    ERIC Educational Resources Information Center

    Atram, Dattatraya Balaram

    2011-01-01

    Fleming's right-hand rule and the right-flat-hand rule are generally applied for determining the direction of flow of induced emf/current in straight conductors. The right-hand-fingers rule is applied for coils only. The right-hand-thumb rule can be applied for either straight conductors or coils. Different rules have to be applied for different…

  16. Direct torque control of permanent magnet synchronous motors with non-sinusoidal back-EMF 

    E-print Network

    Ozturk, Salih Baris

    2009-05-15

    torque control of permanent magnet synchronous motor (PMSM) with sinusoidal back-EMF is discussed in detail. Secondly, the proposed two-phase conduction mode for DTC of BLDC motors is introduced in the constant torque region. In this control scheme, only...

  17. A comparison of important international and national standards for limiting exposure to EMF including the scientific rationale.

    PubMed

    Roy, Colin R; Martin, Lindsay J

    2007-06-01

    A comparison of Eastern (from Russia, Hungary, Bulgaria, Poland, and the Czech Republic) and Western (represented by the International Commission on Non-Ionizing Radiation Protection guidelines and the Institute of Electrical and Electronic Engineers standards) radiofrequency standards reveals key differences. The Eastern approach is to protect against non-thermal effects caused by chronic exposure to low level exposure, and the occupational basic restriction is power load (the product of intensity and exposure duration). In contrast, the Western approach is to protect against established acute biological effects that could signal an adverse health effect, and the principal basic restriction is the specific absorption rate to protect against thermal effects. All of the standards are science-based, but a fundamental difference arises from a lack of agreement on the composition of the reference scientific database and of which adverse effect needs to be protected against. However, differences also exist between the ICNIRP and IEEE standards. An additional complication arises when standards are derived or modified using a precautionary approach. For ELF the differences between ICNIRP and IEEE are more fundamental; namely, differences in the basic restriction used (induced current; in-situ electric field) and the location of breakpoints in the strength-frequency curves result in large differences. In 2006, ICNIRP will initiate the review of their ELF and radiofrequency guidelines, and this will provide an opportunity to address differences in standards and the move towards harmonization of EMF standards and guidelines. PMID:17495666

  18. Comment on ``Designing EMF experiments: What is required to characterize exposure?``

    SciTech Connect

    Wilson, B.

    1995-12-31

    Dr. Valberg has taken an important step in describing what, at the present time, can be considered thorough documentation of exposure parameters in health effects studies related to EMFs. His paper provides important guidance for those entering the field and should serve as a reminder to more experienced investigators that good work can be rendered even more valuable by careful reporting. Evidence for the existence of biological effects from exposure to EMFs that may be encountered in residential and industrial environments is now sufficient to conclude that at least some of these effects are not artifacts. The EMF research community must now determine whether EMF biological effects can lead to adverse health effects in humans and, if so, show what field parameters are involved. This objective will be accomplished only through appropriately thought-out and well-documented observation and experimentation. An important implication of Valberg`s discussion is that engineering support in life science laboratories must be on a level sufficient to accurately determine the field parameters listed in the paper. Before the laboratory data can be fully utilized in achieving the overall objectives of EMF health effects research, personal dosimetry will have to be improved so that field parameters found to be important in laboratory studies can be either directly measured or accurately inferred. Such capability will require a new generation of lightweight portable smart dosimeters capable of continuously gathering magnetic field data over a wide range of frequencies. Over the next few years, Valberg`s long list of possible parameters should be narrowed to a short list of parameters that will merit intensive study in the laboratory and in human environments.

  19. Absolute configuration of neostenine

    NASA Astrophysics Data System (ADS)

    Jiang, Ren-Wang; Ye, Wencai; Shaw, Pang-Chui; But, Paul Pui-Hay; Mak, Thomas C. W.

    2010-03-01

    Heavy atoms bromine and iodine were incorporated into the neostenine ( 1) skeleton through reductive cleavage of the lactone ring, followed by acylation with 4-bromobenzoyl chloride, and salt formation with methyl iodide, respectively. The absolute configuration of the seven chiral centers C1, C9, C9a, C10, C11, C1 and C13 in 1 were assigned as S, S, R, R, R, R, and S, respectively, based on the Flack parameters in X-ray structure refinement, and results from the two heavy atom derivatives are consistent with each other. As many Stemona alkaloids share the same lactone and pyrrolo[1,2-?]azepine nucleus as those in 1, the facile method reported in this paper can be applied for the determination of absolute configurations of similar alkaloids.

  20. Survey and assessment of electric and magnetic field (EMF) public exposure in the transportation environment

    SciTech Connect

    Dietrich, F.M.; Jacobs, W.L.

    1999-03-01

    This research, conducted under the support of the Federal Electric and Magnetic Field Research and Public Information Dissemination (EMF RAPID) Engineering Program, characterized the extreme-low-frequency (ELF) electric and magnetic fields (EMF) which a traveler might encounter while using various forms of transportation. Extensive measurement of field level, frequency, temporal variability and spatial variability are reported for: conventional internal-combustion cars, trucks and buses; electric cars, trucks and buses; commuter trains; ferry boats; jetliners; airport shuttle trams; and escalators and moving sidewalks. Static magnetic field levels are also reported. Where possible, the source of the fields is identified. This effort extends extensive past work which investigated field in electrified trains, subways, light rail vehicles, and a magnetically levitated train by using similar protocols to characterize the complex ELF (3 Hz to 3000 Hz) electric and magnetic fields found in virtually all transportation systems.

  1. DIRECT OBSERVATION OF THE TURBULENT emf AND TRANSPORT OF MAGNETIC FIELD IN A LIQUID SODIUM EXPERIMENT

    SciTech Connect

    Rahbarnia, Kian; Brown, Benjamin P.; Clark, Mike M.; Kaplan, Elliot J.; Nornberg, Mark D.; Rasmus, Alex M.; Taylor, Nicholas Zane; Forest, Cary B.; Jenko, Frank; Limone, Angelo; Pinton, Jean-Francois; Plihon, Nicolas; Verhille, Gautier

    2012-11-10

    For the first time, we have directly measured the transport of a vector magnetic field by isotropic turbulence in a high Reynolds number liquid metal flow. In analogy with direct measurements of the turbulent Reynolds stress (turbulent viscosity) that governs momentum transport, we have measured the turbulent electromotive force (emf) by simultaneously measuring three components of velocity and magnetic fields, and computed the correlations that lead to mean-field current generation. Furthermore, we show that this turbulent emf tends to oppose and cancel out the local current, acting to increase the effective resistivity of the medium, i.e., it acts as an enhanced magnetic diffusivity. This has important implications for turbulent transport in astrophysical objects, particularly in dynamos and accretion disks.

  2. Testing EMF for potential carcinogenic activity: A critical review of animal models

    SciTech Connect

    McCann, J.; Kavet, R.; Rafferty, C.N.

    1995-12-01

    In order to assess the potential of electromagnetic fields (EMF) to influence the process of carcinogenesis, it will be necessary to supplement epidemiological studies with controlled laboratory studies in animals. There are now a number of suitable assays available, which focus on different histopathological forms of cancer and on different stages of carcinogenesis-induction, promotion, progression. In this review we discuss 8 major systems in the context of this generalized carcinogenesis paradigm. Our aim is to bring together what is currently known about the biology of carcinogenesis in these systems to provide a context for evaluating EMF results as they become available. To date, results do not clearly demonstrate the carcinogenic potential of magnetic fields. More definitive conclusions must await the completion of ongoing studies.

  3. Impact of a Small Cell on the RF-EMF Exposure in a Train

    PubMed Central

    Aerts, Sam; Plets, David; Thielens, Arno; Martens, Luc; Joseph, Wout

    2015-01-01

    The deployment of a miniature mobile-phone base station or small cell in a train car significantly improves the coverage and the capacity of a mobile network service on the train. However, the impact of the small cell on the passengers’ exposure to radio-frequency electromagnetic fields (RF-EMF) is unknown. In this study, we assessed experimentally the RF-EMF exposure of a mobile-phone user who is either connected to the outdoor macrocell network or to an in-train small cell, while traveling on the train, by means of the absorbed-dose concept, which combines the base station downlink exposure with the mobile-phone uplink exposure. For Global System for Mobile Communications (GSM) technology at 1800 MHz, we found that by connecting to a small cell, the brain exposure of the user could realistically be reduced by a factor 35 and the whole-body exposure by a factor 11. PMID:25734793

  4. Effects of W-CDMA 1950 MHz EMF emitted by mobile phones on regional cerebral blood flow in humans.

    PubMed

    Mizuno, Yoko; Moriguchi, Yoshiya; Hikage, Takashi; Terao, Yasuo; Ohnishi, Takashi; Nojima, Toshio; Ugawa, Yoshikazu

    2009-10-01

    Use of the third generation mobile phone system is increasing worldwide. This is the first study to investigate the effects of the third generation system on regional cerebral blood flow (rCBF) in humans. We compared effects of the electromagnetic field (EMF) emitted from the Wideband Code Division Multiple Access (W-CDMA) cellular system versus sham control exposure on rCBF in humans. Nine healthy male volunteers participated in this study. Positron emission tomography (PET) scans were obtained before, during, and after unilateral 30 min EMF exposure. The subtraction analysis revealed no significant rCBF changes caused by the EMF conditions compared with the sham exposure, suggesting that EMF emitted by a third generation mobile phone does not affect rCBF in humans. PMID:19475648

  5. Thermodynamic properties of calcium-bismuth alloys determined by emf measurements

    SciTech Connect

    Kim, H; Boysen, DA; Bradwell, DJ; Chung, BC; Jiang, K; Tomaszowska, AA; Wang, KL; Wei, WF; Sadoway, DR

    2012-01-15

    The thermodynamic properties of Ca-Bi alloys were determined by electromotive force (emf) measurements to assess the suitability of Ca-Bi electrodes for electrochemical energy storage applications. Emf was measured at ambient pressure as a function of temperature between 723 K and 1173 K using a Ca(s)vertical bar CaF2(s)vertical bar Ca(in Bi) cell for twenty different Ca-Bi alloys spanning the entire range of composition from chi(Ca) = 0 to 1. Reported are the temperature-independent partial molar entropy and enthalpy of calcium for each Ca-Bi alloy. Also given are the measured activities of calcium, the excess partial molar Gibbs energy of bismuth estimated from the Gibbs-Duhem equation, and the integral change in Gibbs energy for each Ca-Bi alloy at 873 K, 973 K, and 1073 K. Calcium activities at 973 K were found to be nearly constant at a value a(Ca) = 1 x 10(-8) over the composition range chi(Ca) = 0.32-0.56, yielding an emf of similar to 0.77 V. Above chi(Ca) = 0.62 and coincident with Ca5Bi3 formation, the calcium activity approached unity. The Ca-Bi system was also characterized by differential scanning calorimetry over the entire range of composition. Based upon these data along with the emf measurements, a revised Ca-Bi binary phase diagram is proposed. (C) 2011 Elsevier Ltd. All rights reserved.

  6. Drosophila oogenesis as a bio-marker responding to EMF sources.

    PubMed

    Margaritis, Lukas H; Manta, Areti K; Kokkaliaris, Konstantinos D; Schiza, Dimitra; Alimisis, Konstantinos; Barkas, Georgios; Georgiou, Eleana; Giannakopoulou, Olympia; Kollia, Ioanna; Kontogianni, Georgia; Kourouzidou, Angeliki; Myari, Angeliki; Roumelioti, Fani; Skouroliakou, Aikaterini; Sykioti, Vasia; Varda, Georgia; Xenos, Konstantinos; Ziomas, Konstantinos

    2014-09-01

    The model biological organisms Drosophila melanogaster and Drosophila virilis have been utilized to assess effects on apoptotic cell death of follicles during oogenesis and reproductive capacity (fecundity) decline. A total of 280 different experiments were performed using newly emerged flies exposed for short time daily for 3-7?d to various EMF sources including: GSM 900/1800?MHz mobile phone, 1880-1900?MHz DECT wireless base, DECT wireless handset, mobile phone-DECT handset combination, 2.44?GHz wireless network (Wi-Fi), 2.44?GHz blue tooth, 92.8?MHz FM generator, 27.15?MHz baby monitor, 900?MHz CW RF generator and microwave oven's 2.44?GHz RF and magnetic field components. Mobile phone was used as a reference exposure system for evaluating factors considered very important in dosimetry extending our published work with D. melanogaster to the insect D. virilis. Distance from the emitting source, the exposure duration and the repeatability were examined. All EMF sources used created statistically significant effects regarding fecundity and cell death-apoptosis induction, even at very low intensity levels (0.3?V/m blue tooth radiation), well below ICNIRP's guidelines, suggesting that Drosophila oogenesis system is suitable to be used as a biomarker for exploring potential EMF bioactivity. Also, there is no linear cumulative effect when increasing the duration of exposure or using one EMF source after the other (i.e. mobile phone and DECT handset) at the specific conditions used. The role of the average versus the peak E-field values as measured by spectrum analyzers on the final effects is discussed. PMID:23915130

  7. Preparation of EmfI cell stocks 1. Sacrifice the pregnant mouse when embryos are 14 dpc. Moisten the belly

    E-print Network

    . Use a hotplate placed into a 370 C incubator with a magnetic stir on. Place the tube in a rack once more if needed. 8. Collect the cell suspension into a new 50ml Falcon tube and add 3ml of FBS solution containing EmfIs to the rest of EmfI suspension. 9. Spin cells at 270g for 8 minutes. 10

  8. Effects of electromagnetic fields (EMF) on the chemiluminescence (CL) of murine peritoneal exudate cells

    SciTech Connect

    Caren, L.D. )

    1992-02-26

    Stimulated PEC generate microbicidal free oxygen radicals which are potentially mutagenic and possibly carcinogenic. The effects of combined alternating electric and magnetic fields on oxygen radical production were measured in this study. A Helmholtz coil and parallel plate electrodes were utilized to provide uniform field characteristics. Effects were studied at combined field frequencies of 60, 600, and 6,000 Hz. Thioglycollate-elicited PEC were exposed to EMF or placed in a far corner of the lab (controls). Following the addition of zymosan, luminol-enhanced CL was measured. No differences in CL were found for exposures to 60 Hz for 18 hr; 600 Hz for 10 hr; or 6,000 Hz for 0.75 hr. PEC exposed to 6,000 Hz for 11 hr showed a 25% increase in CL over control PEC. At 600 and 6,000 Hz, the temperature of the air and a dish of saline in the EMF apparatus was 26C, vs. 25C where the controls were kept. At 60 Hz, there was no temperature difference. These preliminary experiments indicate that under these conditions, EMF fields do not have a significant effect on this immune function.

  9. RF-EMF exposure of fetus and mother during magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Pediaditis, M.; Leitgeb, N.; Cech, R.

    2008-12-01

    Magnetic resonance imaging (MRI) avoids risks of genetic damage but may be associated with excess heating of body tissues. To investigate the exposure to MRI radio-frequency (RF) electromagnetic fields (EMF), low-pass and high-pass birdcage coils were simulated and the whole-body pregnant woman model SILVY used to determine local and whole-body specific absorption rates (SAR) in mother and fetus. Resonant RF-EMF of MRI devices were investigated at 0.3, 1, 1.5, 2, 3 and 4 T. Results allow extrapolation also to higher fields. They showed that local SAR in mother's trunk reaches exposure limits first. However, data show that during abdominal MRI meeting exposure limits of the mother is not sufficient to protect the fetus if limits of the general populations are applied to it. In that case fetal whole-body SAR exceeds limits by 7.4-fold. It is up to the physician and/or the ethics commission to decide upon justification for abdominal MRI of pregnant women if limits are exceeded. The results indicate the need for specifically addressing fetal exposure to EMF and elaborating general recommendations by radiation protection bodies.

  10. Effect of ELF-EMF Exposure on Human Neuroblastoma Cell Line: a Proteomics Analysis

    PubMed Central

    Hasanzadeh, Hadi; Rezaie-Tavirani, Mostafa; Seyyedi, Samaneh Sadat; Zali, Hakimeh; Heydari Keshel, Saeid; Jadidi, Majid; Abedelahi, Ali

    2014-01-01

    Background Extremely low frequency electromagnetic fields (ELF-EMF) have been common in daily life all over the world. They have produced by power lines and electrical appliances, but higher levels of them have raised a lot of concerns about their carcinogenesis. Both epidemiological and laboratory studies have suggested that EMFs might increase cancer incidence, including acute childhood leukemia, brain and breast cancer. Methods In the present study, SH-SY5Y human neuroblastoma cell line has exposed to 2mT, 50 Hz magnetic field for 3 h. Next, effect of this exposure on protein expression including over-expression or under-expression has assessed by proteomics. Results Bioinformatics and statistical analysis using progenesis same spot software on the obtained 2D electrophoresis has shown that expression of 189 proteins in exposed group has changed relative to control. Besides, PCA analysis has verified results of clustering, and has shown that protein data has clustered according to experimental conditions. Conclusion The results of this study have shown that ELF-EMF changes cell morphology via altering protein expression, but more profound studies have needed to determine the kind of proteins altered. PMID:25250144

  11. The information as Absolute

    E-print Network

    Sergey V. Shevchenko; Vladimir V. Tokarevsky

    2013-03-11

    This article presents and grounds (i.e. presents proof of the existence, the truth, the self-consistence and the completeness of)the informational conception ("the Information as Absolute" conception)in physics and philosophy. the conception defines the information as an ultimately common, real and fundamental concept/phenomenon - "Absolute", which exists as anabsolutely infinite set ("Information" Set) of elements (members) and informational (e.g., logical) linksbetween the elements; where any element itself is some informational structure also. Correspondingly, for example, Matter as the substence, radiation, etc., is some development or realization of informational patterns, constituting a specific - and practically infinitesimal comparing to the Set - subset of the "Information" Set. The conception allows for the resolution, or at least for a consideration on a higher level of comprehension, of the basic ontological and epistemological problems in philosophy and natural sciences; in physics it allows to suggest reasonable model, which makes more clear basic phisical notions,such as space, time, matter, etc.

  12. Measuring electromagnetic fields (EMF) around wind turbines in Canada: is there a human health concern?

    PubMed Central

    2014-01-01

    Background The past five years has seen considerable expansion of wind power generation in Ontario, Canada. Most recently worries about exposure to electromagnetic fields (EMF) from wind turbines, and associated electrical transmission, has been raised at public meetings and legal proceedings. These fears have not been based on any actual measurements of EMF exposure surrounding existing projects but appear to follow from worries from internet sources and misunderstanding of the science. Methods The study was carried out at the Kingsbridge 1 Wind Farm located near Goderich, Ontario, Canada. Magnetic field measurements were collected in the proximity of 15 Vestas 1.8 MW wind turbines, two substations, various buried and overhead collector and transmission lines, and nearby homes. Data were collected during three operational scenarios to characterize potential EMF exposure: ‘high wind’ (generating power), ‘low wind’ (drawing power from the grid, but not generating power) and ‘shut off’ (neither drawing, nor generating power). Results Background levels of EMF (0.2 to 0.3 mG) were established by measuring magnetic fields around the wind turbines under the ‘shut off’ scenario. Magnetic field levels detected at the base of the turbines under both the ‘high wind’ and ‘low wind’ conditions were low (mean = 0.9 mG; n = 11) and rapidly diminished with distance, becoming indistinguishable from background within 2 m of the base. Magnetic fields measured 1 m above buried collector lines were also within background (? 0.3 mG). Beneath overhead 27.5 kV and 500 kV transmission lines, magnetic field levels of up to 16.5 and 46 mG, respectively, were recorded. These levels also diminished rapidly with distance. None of these sources appeared to influence magnetic field levels at nearby homes located as close as just over 500 m from turbines, where measurements immediately outside of the homes were ? 0.4 mG. Conclusions The results suggest that there is nothing unique to wind farms with respect to EMF exposure; in fact, magnetic field levels in the vicinity of wind turbines were lower than those produced by many common household electrical devices and were well below any existing regulatory guidelines with respect to human health. PMID:24529028

  13. Biological monitoring of non-thermal effects of mobile phone radiation: recent approaches and challenges.

    PubMed

    Gaestel, Matthias

    2010-08-01

    This review describes recent developments in analysing the influence of radio-frequency electromagnetic fields (RF-EMFs ) on biological systems by monitoring the cellular stress response as well as overall gene expression. Recent data on the initiation and modulation of the classical cellular stress response by RF-EMFs, comprising expression of heat shock proteins and stimulation of stress-activated protein kinases, are summarised and evaluated. Since isothermic RF-EMF exposure is assumed rather than proven there are clear limitations in using the stress response to describe non-thermal effects of RF-EMFs. In particular, further experiments are needed to characterise better the threshold of the thermal heat shock response and the homogeneity of the cellular response in the whole sample for each biological system used. Before then, it is proposed that the absence of the classical stress response can define isothermal experimental conditions and qualifies other biological effects of RF-EMFs detected under these conditions to be of non-thermal origin. To minimise the probability that by making this assumption valuable insights into the nature of biological effects of RF-EMFs could be lost, proteotoxic non-thermal RF-EMF effects should also be monitored by measuring activities of labile intracellular enzymes and/or levels of their metabolites before the threshold for the heat shock response is reached. In addition, non-thermal induction of the stress response via promoter elements distinct from the heat shock element (HSE) should be analysed using HSE-mutated heat shock promoter reporter constructs. Screening for non-thermal RF-EMF effects in the absence of a classical stress response should be performed by transcriptomics and proteomics. Recent approaches demonstrate that due to their high-throughput characteristics, these methods inherently generate false positive results and require statistical evaluation based on quantitative expression analysis from a sufficient number of independent experiments with identical parameters. In future approaches, positive results must be confirmed by independent quantitative methods and should also be evaluated in vivo to prove possible non-thermal effects of RF-EMFs on living beings. If successful, this strategy should contribute to identification of new underlying molecular mechanisms of interaction between RF-EMFs and living beings distinct from absorption of thermal energy. PMID:20015314

  14. Absolute Equilibrium Entropy

    NASA Technical Reports Server (NTRS)

    Shebalin, John V.

    1997-01-01

    The entropy associated with absolute equilibrium ensemble theories of ideal, homogeneous, fluid and magneto-fluid turbulence is discussed and the three-dimensional fluid case is examined in detail. A sigma-function is defined, whose minimum value with respect to global parameters is the entropy. A comparison is made between the use of global functions sigma and phase functions H (associated with the development of various H-theorems of ideal turbulence). It is shown that the two approaches are complimentary though conceptually different: H-theorems show that an isolated system tends to equilibrium while sigma-functions allow the demonstration that entropy never decreases when two previously isolated systems are combined. This provides a more complete picture of entropy in the statistical mechanics of ideal fluids.

  15. Measurement of the absolute \

    SciTech Connect

    Aunion, Jose Luis Alcaraz; /Barcelona, IFAE

    2010-07-01

    This thesis presents the measurement of the charged current quasi-elastic (CCQE) neutrino-nucleon cross section at neutrino energies around 1 GeV. This measurement has two main physical motivations. On one hand, the neutrino-nucleon interactions at few GeV is a region where existing old data are sparse and with low statistics. The current measurement populates low energy regions with higher statistics and precision than previous experiments. On the other hand, the CCQE interaction is the most useful interaction in neutrino oscillation experiments. The CCQE channel is used to measure the initial and final neutrino fluxes in order to determine the neutrino fraction that disappeared. The neutrino oscillation experiments work at low neutrino energies, so precise measurement of CCQE interactions are essential for flux measurements. The main goal of this thesis is to measure the CCQE absolute neutrino cross section from the SciBooNE data. The SciBar Booster Neutrino Experiment (SciBooNE) is a neutrino and anti-neutrino scattering off experiment. The neutrino energy spectrum works at energies around 1 GeV. SciBooNE was running from June 8th 2007 to August 18th 2008. In that period, the experiment collected a total of 2.65 x 10{sup 20} protons on target (POT). This thesis has used full data collection in neutrino mode 0.99 x 10{sup 20} POT. A CCQE selection cut has been performed, achieving around 70% pure CCQE sample. A fit method has been exclusively developed to determine the absolute CCQE cross section, presenting results in a neutrino energy range from 0.2 to 2 GeV. The results are compatible with the NEUT predictions. The SciBooNE measurement has been compared with both Carbon (MiniBoonE) and deuterium (ANL and BNL) target experiments, showing a good agreement in both cases.

  16. DETERMINATION OF ACTIVITY COEFFICIENTS USING A FLOW EMF METHOD. 2. NaCl-K2SO4-H2O SYSTEM

    E-print Network

    Zhang, Luzheng

    #12;DETERMINATION OF ACTIVITY COEFFICIENTS USING A FLOW EMF METHOD. 2. NaCl-K2SO4-H2O SYSTEM AT 298 In this study, a flow electromotive force (EMF) method proposed by the authors was extended to mixed electrolyte electrolyte in mixed solvent rapidly. The EMF data for the ternary system NaCl(1)-K2SO4(2)-H2O(3) without

  17. Safety of high speed guided ground transportation systems. Broadband magnetic fields: Their possible role in EMF-associated bioeffects. Final report, January 1993-June 1993

    SciTech Connect

    Goellner, D.; Wilson, B.; Reiter, R.; Pilla, A.; Hankin, N.

    1993-08-01

    The report reviews electric and magnetic field (EMF) exposures from electrical transportation systems, including electrically powered rail and magnetic levitation (maglev). Material also covered includes research concerning biological effects of EMF exposure, with special emphasis on broad spectrum or broadband magnetic fields. A primary objective of the report was to consider, based on present knowledge, the potential for adverse health effects from maglev-associated EMF. Because maglev technology is known to generate magnetic fields at a variety of frequencies, the document addresses the broadband EMF frequency characteristics (including pulses, intermittent fields, and other transient phenomena).

  18. The electric and magnetic fields research and public information dissemination (EMF-RAPID) program.

    PubMed

    Moulder, J E

    2000-05-01

    In the United States, public concern that exposure to power-line fields was linked to cancer led to the establishment of a Congressionally mandated program, the Electric and Magnetic Fields Research and Public Information Dissemination (EMF-RAPID) Program. A major goal of the program was to "determine whether or not exposures to electric and magnetic fields produced by the generation, transmission, and use of electrical energy affect human health". Between 1994 and 1998, the EMF-RAPID program spent approximately $41 million on biological research. Much of the work funded by the EMF-RAPID program has not yet been published in the peer-reviewed literature. The U.S. National Institute of Environmental Health Sciences (NIEHS) asked that Radiation Research publish this special issue in an attempt to remedy this publication gap. The issue includes reviews of studies that were done to assess the biological plausibility of claims that power-frequency fields caused leukemia and breast cancer. The issue continues with two teratology studies and one immunology study. The section of the issue covering in vitro studies begins with an overview of the efforts NIEHS made to replicate a wide range of reported effects of power-frequency fields and continues with four papers reporting the absence of effects of power-frequency fields on the expression of stress-response genes and oncogenes. Other reports of in vitro studies and studies of mechanisms cover cytotoxicity, gap junction intracellular communication, calcium ion transport across the plasma membrane, and intracellular electric fields. PMID:10790283

  19. The role of renewable energy in climate stabilization: results from the EMF 27 scenarios

    SciTech Connect

    Luderer, Gunnar; Krey, Volker; Calvin, Katherine V.; Merrick, James; Mima, Silvana; Pietzcker, Robert; Van Vliet, Jasper; Wada, Kenichi

    2013-10-15

    This paper uses the EMF27 scenarios to explore the role of renewable energy (RE) in climate change mitigation. Currently RE supplies almost 20 % of global electricity demand. Almost all EMF27 mitigation scenarios show a strong increase in renewable power production, with a substantial ramp-up of wind and solar power deployment. In many scenarios, renewables are the most important long-term mitigation option for power supply. Wind energy is competitive even without climate policy, whereas the prospects of solar photovoltaics (PV) are highly contingent on the ambitiousness of climate policy. Bioenergy is an important and versatile energy carrier; however—with the exception of low temperature heat—there is less scope for renewables other than biomass for non-electric energy supply. Despite the important role of wind and solar power in climate change mitigation scenarios with full technology availability, limiting their deployment has a relatively small effect on mitigation costs, if nuclear and carbon capture and storage (CCS)—which can serve as substitutes in low-carbon power supply—are available. Limited bioenergy availability in combination with limited wind and solar power by contrast, results in a more substantial increase in mitigation costs. While a number of robust insights emerge, the results on renewable energy deployment levels vary considerably across the models. An in-depth analysis of a subset of EMF27 reveals substantial differences in modeling approaches and parameter assumptions. To a certain degree, differences in model results can be attributed to different assumptions about technology costs, resource potentials and systems integration.

  20. The Absolute Relativity Theory

    E-print Network

    Jean-Marc Oury; Bruno Heintz

    2009-08-18

    This paper is a first presentation of a new approach of physics that we propose to refer as the Absolute Relativity Theory (ART) since it refutes the idea of a pre-existing space-time. It includes an algebraic definition of particles, interactions and Lagrangians. It proposed also a purely algebraic explanation of the passing of time phenomenon that leads to see usual Euler-Lagrange equations as the continuous version of the Knizhnik-Zamolodchikov monodromy. The identification of this monodromy with the local ones of the Lorentzian manifolds gives the Einstein equation algebraically explained in a quantized context. A fact that could lead to the unification of physics. By giving an algebraic classification of particles and interactions, the ART also proposes a new branch of physics, namely the Mass Quantification Theory, that provides a general method to calculate the characteristics of particles and interactions. Some examples are provided. The MQT also predicts the existence of as of today not yet observed particles that could be part of the dark matter. By giving a new interpretation of the weak interaction, it also suggests an interpretation of the so-called dark energy.

  1. Higher order concentration moments collapse in the expected mass fraction (EMF) based risk assessment

    NASA Astrophysics Data System (ADS)

    Srzic, Veljko; Gotovac, Hrvoje; Cvetkovic, Vladimir; Andricevic, Roko

    2014-05-01

    In this work Langrangian framework is used for conservative tracer transport simulations through 2-D extremely heterogeneous porous media. Conducted numerical simulations enable large sets of concentration values in both spatial and temporal domains. In addition to the advection, which acts on all scales, an additional mechanism considered is local scale dispersion (LSD), accounting for both mechanical dispersion and molecular diffusion. The ratio between these two mechanisms is quantified by the Peclet (Pe) number. In its base, the work gives answers to concentration scalar features when influenced by: i) different log-conductivity variance; ii) log-conductivity structures defined by the same global variogram but with different log conductivity patterns correlated; and iii) for a wide range of Peclet values. Results conducted by Monte Carlo analysis show a complex interplay between the aforementioned parameters, indicating the influence of aquifer properties to temporal LSD evolution. A remarkable collapse of higher order to second-order concentration moments [Yee, 2009] leads to the conclusion that only two concentration moments are required for an accurate description of concentration fluctuations. This explicitly holds for the pure advection case, while in the case of LSD presence the moment deriving function(MDF) is involved to ensure the moment collapse validity. An inspection of the Beta distribution leads to the conclusion that the two-parametric distribution can be used for concentration fluctuation characterization even in cases of high aquifer heterogeneity and/or for different log-conductivity structures, independent of the sampling volume used. Furthermore, the expected mass fraction (EMF) [Heagy & Sullivan, 1996] concept is applied in groundwater transport. In its origin, EMF is function of the concentration but with lower number of realizations needed for its determination, compared to the one point PDF. From practical point of view, EMF excludes meandering effect and incorporates information about exposure time for each non-zero concentration value present. Also, it is shown that EMF is able to clearly reflect the effects of aquifer heterogeneity and structure as well as the Pe value. The latter is demonstrated through the non-carcinogenic risk assessment framework. To demonstrate the uniqueness of the moment collapse feature and ability of the Beta distribution to account for the concentration frequencies even in real cases, Macrodispersion Experiment (MADE1) [Boggs et al, 1992] data sets are used for validation.

  2. Photo-EMF sensitivity of porous silicon thin layer-crystalline silicon heterojunction to ammonia adsorption.

    PubMed

    Vashpanov, Yuriy; Jung, Jae Il; Kwack, Kae Dal

    2011-01-01

    A new method of using photo-electromotive force in detecting gas and controlling sensitivity is proposed. Photo-electromotive force on the heterojunction between porous silicon thin layer and crystalline silicon wafer depends on the concentration of ammonia in the measurement chamber. A porous silicon thin layer was formed by electrochemical etching on p-type silicon wafer. A gas and light transparent electrical contact was manufactured to this porous layer. Photo-EMF sensitivity corresponding to ammonia concentration in the range from 10 ppm to 1,000 ppm can be maximized by controlling the intensity of illumination light. PMID:22319353

  3. Absolute Identification by Relative Judgment

    ERIC Educational Resources Information Center

    Stewart, Neil; Brown, Gordon D. A.; Chater, Nick

    2005-01-01

    In unidimensional absolute identification tasks, participants identify stimuli that vary along a single dimension. Performance is surprisingly poor compared with discrimination of the same stimuli. Existing models assume that identification is achieved using long-term representations of absolute magnitudes. The authors propose an alternative…

  4. Safety of high speed guided ground transportation systems: EMF exposure environments. Summary report. Final report, January-June 1993

    SciTech Connect

    Goellner, D.; Inge, T.; Gillette, L.; Hankin, N.; Hostage, B.

    1993-08-01

    The paper presents an overview of American exposure assessments for electric and magnetic fields (EMF) in the frequency range from 0 to 3 kHz. The exposure information available is very limited for all but a few occupations and sources of EMF. Much of the exposure assessment done to date has been conducted in conjunction with epidemiological studies. Beyond the shortcomings of using some of the published epidemiology studies, there are some serious obstacles to conducting definitive extreme low frequency (ELF)-EMF exposure assessments. The lack of a clear definition of what constitutes effective dose hampers the measurement of exposure considerably. Generally, the average power frequency magnetic flux density has been assumed to be the exposure measure of significance, however other parameters of the magnetic field are likely to be relevant as well.

  5. Standard Gibbs energy of formation of Mo 3Te 4 by emf measurements

    NASA Astrophysics Data System (ADS)

    Mallika, C.; Sreedharan, O. M.

    1990-03-01

    The emf of the galvanic cells Pt, Mo, MoO 2¦8 YSZ¦'FeO', Fe, Pt (I) and Pt, Fe,'FeO' ¦8 YSZ¦MoO 2, Mo 3Te 4, MoTe 2(?), C, Pt (II) were measured over the temperature ranges 837 to 1151 K and 775 to 1196 K, respectively, using 8 mass% yttria-stabilized zirconia (8 YSZ) as the solid electrolyte. From the emf values, the partial molar Gibbs energy of solution of molybdenum in Mo 3Te 4/MoTe 2(?), ? ?Mo was found to be ? ?Mo ± 1.19 ( kJ/mol) = -025.08 + 0.00420T(K) . Using the literature data for the Gibbs energy of formation of MoTe 2(?). the expression ?G° f( Mo3Te4, s) ± 5.97 (kj/mol) = -253.58 + 0.09214 T( K) was derived for the range 775 to 1196 K. A third-law analysis yielded a value of -209 ± 10 kJ/mol for ?H° f.298o of Mo 3Te 4(s).

  6. Assessment and comparison of total RF-EMF exposure in femtocell and macrocell base station scenarios.

    PubMed

    Aerts, Sam; Plets, David; Verloock, Leen; Martens, Luc; Joseph, Wout

    2014-12-01

    The indoor coverage of a mobile service can be drastically improved by deployment of an indoor femtocell base station (FBS). However, the impact of its proximity on the total exposure of the human body to radio-frequency (RF) electromagnetic fields (EMFs) is unknown. Using a framework designed for the combination of near-field and far-field exposure, the authors assessed and compared the RF-EMF exposure of a mobile-phone (MP) user that is either connected to an FBS or a conventional macrocell base station while in an office environment. It is found that, in average macrocell coverage and MP use-time conditions and for Universal Mobile Telecommunications System technology, the total exposure can be reduced by a factor of 20-40 by using an FBS, mostly due to the significant decrease in the output power of the MP. In general, the framework presented in this study can be used for any exposure scenario, featuring any number of technologies, base stations and/or access points, users and duration. PMID:24185915

  7. Effects of 940 MHz EMF on bioluminescence and oxidative response of stable luciferase producing HEK cells.

    PubMed

    Sefidbakht, Yahya; Moosavi-Movahedi, Ali Akbar; Hosseinkhani, Saman; Khodagholi, Fariba; Torkzadeh-Mahani, Masoud; Foolad, Forough; Faraji-Dana, Reza

    2014-07-01

    The effects of mobile phone frequency electromagnetic field (RF-EMF, 940 MHz) on a stable cell line (HEK293T) harbouring the firefly luciferase gene were evaluated. A waveguide exposure system with 1 W input power provided the mean specific absorption rate of ?0.09 W kg(-1) in 35 mm Petri dishes. The effects of exposure duration (15, 30, 45, 60 and 90 min) on luciferase activity and oxidative response elements were investigated. Endogenous luciferase activity was reduced after 30 and 45 min of continuous exposure, while after 60 min, the exposed cell lysate showed higher luciferase activity compared with the non-exposed control. Reactive oxygen species (ROS) generation was highest in the 30 min exposed cells as studied by 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescence. The observed boost in ROS was then followed by a sharp rise in catalase (CAT) and superoxide dismutase (SOD) activity and elevation of glutathione (GSH) during the 45 min exposure. Decrease in lipid peroxidation (malondialdehyde, MDA) was meaningful for the 45 and 60 min exposed cells. Therefore, it appears that an increase in the activity of luciferase after 60 min of continuous exposure could be associated with a decrease in ROS level caused by activation of the oxidative response. This ability in cells to overcome oxidative stress and compensate the luciferase activity could also be responsible for the adaptive response mechanism detected in ionizing radiation studies with RF-EMF pre-treatments. PMID:24886806

  8. Absolute cavity pyrgeometer

    DOEpatents

    Reda, Ibrahim

    2013-10-29

    Implementations of the present disclosure involve an apparatus and method to measure the long-wave irradiance of the atmosphere or long-wave source. The apparatus may involve a thermopile, a concentrator and temperature controller. The incoming long-wave irradiance may be reflected from the concentrator to a thermopile receiver located at the bottom of the concentrator to receive the reflected long-wave irradiance. In addition, the thermopile may be thermally connected to a temperature controller to control the device temperature. Through use of the apparatus, the long-wave irradiance of the atmosphere may be calculated from several measurements provided by the apparatus. In addition, the apparatus may provide an international standard of pyrgeometers' calibration that is traceable back to the International System of Units (SI) rather than to a blackbody atmospheric simulator.

  9. mTOR Activation by PI3K/Akt and ERK Signaling in Short ELF-EMF Exposed Human Keratinocytes

    PubMed Central

    Patruno, Antonia; Pesce, Mirko; Grilli, Alfredo; Speranza, Lorenza; Franceschelli, Sara; De Lutiis, Maria Anna; Vianale, Giovina; Costantini, Erica; Amerio, Paolo; Muraro, Raffaella; Felaco, Mario; Reale, Marcella

    2015-01-01

    Several reports suggest that ELF-EMF exposures interact with biological processes including promotion of cell proliferation. However, the molecular mechanisms by which ELF-EMF controls cell growth are not completely understood. The present study aimed to investigate the effect of ELF-EMF on keratinocytes proliferation and molecular mechanisms involved. Effect of ELF-EMF (50 Hz, 1 mT) on HaCaT cell cycle and cells growth and viability was monitored by FACS analysis and BrdU assay. Gene expression profile by microarray and qRT-PCR validation was performed in HaCaT cells exposed or not to ELF-EMF. mTOR, Akt and MAPKs expressions were evaluated by Western blot analysis. In HaCaT cells, short ELF-EMF exposure modulates distinct patterns of gene expression involved in cell proliferation and in the cell cycle. mTOR activation resulted the main molecular target of ELF-EMF on HaCaT cells. Our data showed the increase of the canonical pathway of mTOR regulation (PI3K/Akt) and activation of ERK signaling pathways. Our results indicate that ELF-EMF selectively modulated the expression of multiple genes related to pivotal biological processes and functions that play a key role in physio-pathological mechanisms such as wound healing. PMID:26431550

  10. Absolute measurement of cerebral optical coefficients, hemoglobin

    E-print Network

    Fantini, Sergio

    Absolute measurement of cerebral optical coefficients, hemoglobin concentration and oxygen Aron M. Troen Sergio Fantini #12;Absolute measurement of cerebral optical coefficients, hemoglobin-infrared spectroscopy measurement of absolute cerebral hemoglobin concentration and saturation in a large sample of 36

  11. Body mass index as a risk prediction and prevention factor for professional mixed low-intensity EMF burden.

    PubMed

    Vesselinova, Lyubina

    2015-09-01

    The exposure conditions in the physiotherapy are characterized with various sources emitting electromagnetic fields (EMF) in different frequency ranges. Very little is known about the exposure modalities' influence on the operators. In this article, we present the effects of EMF on personnel morbidity profile dependent on the body mass index (BMI) increase. By cross-tabulation, the role of higher BMI on enhancing the EMF vulnerability potential is confirmed. The correlation of the higher BMI with some serious diseases and conditions' development has been evidenced statistically significant. ?y the whole-studied group, a general tendency for allergy, cardiovascular diseases, sleep disruption and age-shortened menopause, as well as allergy and leiomyoma in the expositional criteria subgroups (ESG), formed for the purposes of this study, is evidenced. The three ESGs are formed on work residence duration in the electrolight therapy section. The first - up to four working hour daily, the second - the entire working day (7?h) and the third group is not residenced in the electrolight therapy section. We hypothesize two signaling ways of interaction of the chronically low-intensity EMF and the higher BMI as the most likely: hormonal - by melatonin levels decrease due to estrogen levels increasing and endocrine - mast-cells auto replication and degranulation stimulation. Based on the results of the study, the BMI increase as an observed control factor in the prediction of the professional risk can be recommended. PMID:26444199

  12. Analysis of standard reference materials by absolute INAA

    SciTech Connect

    Heft, R.E.; Koszykowski, R.F.

    1981-07-01

    Three standard reference materials, flyash, soil, and ASI 4340 steel, were analyzed by a method of absolute instrumental neutron activation analysis (INAA). Two different light water pool-type reactors were used to produce equivalent analytical results even though the epithermal to thermal flux ratio in one reactor was higher than that in the other by a factor of two.

  13. Cadmium activities of silver-cadmium alloys determined from measurements on emf cells involving displacement reactions

    SciTech Connect

    Houseman, B.L.; Conant, D.R.

    1984-01-01

    Cadmium activities have been obtained for dilute solutions of silver in cadmium at 776 K from emf measurements using the cell: W-Cd/CdI' + Cd (A/sub Cd/ = 1) parallels CdI'' + AgI + Cd (a/sub Cd/) < 1)/Cd, Ag-W. When the displacement reaction 2Ag + CdI'' i Cd + 2AgI is taken into account, the calculated cadmium activities follow the equation a/sub Cd/ = 1 - N/sub Ab/ - 0.607 N''/sub Ag/ with a standard deviation of 0.00001 for those measurements (taken by the most precise method) used in the least squares fit. The largest deviation from the curve for all points measured was 0.0006 or 0.9 g/cal in G/sub Cd/.

  14. Rigorous EMF simulation of absorber shape variations and their impact on lithographic processes

    NASA Astrophysics Data System (ADS)

    Rahimi, Z.; Erdmann, A.; Evanschitzky, P.; Pflaum, C.

    2010-05-01

    We present a finite integration technique (FIT) simulator for modelling light diffraction from lithographic masks with complex shapes. This method has high flexibility in geometrical modelling and treating curved boundaries. The inherent feature of FIT allows more accurate rigorous electromagnetic field simulation in complex structures. This technique is also suited for fast EMF simulations and large 3D problems because of its parallelisation potential. We applied this method to investigate the effect of various mask shapes on lithographically printed images. The imaging results were obtained using Dr.LiTHO's imaging simulator. We demonstrate results for attenuated phase-shift mask (PSM) with different absorber deviations from ideal shapes such as footing and oblique sidewalls.

  15. Occupational EMF exposure from radar at X and Ku frequency band and plasma catecholamine levels.

    PubMed

    Singh, Sarika; Kapoor, Neeru

    2015-09-01

    Workers in certain occupations such as the military may be exposed to technical radiofrequency radiation exposure above current limits, which may pose a health risk. The present investigation intended to find the effect of chronic electromagnetic field (EMF) exposure from radar on plasma catecholamines in the military workforce. In the study, 166 male personnel selected randomly were categorized into three groups: control (n?=?68), exposure group-I (X-band, 8-12?GHz, n?=?40), and exposure group-II (Ku-band, 12.5-18?GHz, n?=?58). The three clusters were further divided into two groups according to their years of service (YOS) (up to 9 years and ?10 years) to study the effect of years of radar exposure. Enzyme immunoassay was employed to assess catecholamine concentrations. EMF levels were recorded at different occupational distances from radar. Significant adrenaline diminution was registered in exposure group-II with no significant difference in exposure group-I when both groups were weighed against control. Nor-adrenaline and dopamine levels did not vary significantly in both exposure groups when compared to controls. Exposure in terms of YOS also did not yield any significant alteration in any of the catecholamines and in any of the exposure groups when compared with their respective control groups. The shift from baseline catecholamine values due to stress has immense significance for health and well-being. Their continual alteration may prove harmful in due course. Suitable follow-up studies are needed to further strengthen these preliminary observations and for now, exposures should be limited as much as possible with essential safeguards. PMID:26058851

  16. Lack of an EMF-induced genotoxic effect in the Ames assay

    SciTech Connect

    Morandi, M.A.; Pak, C.M.; Caren, R.P.; Caren, L.D.

    1996-12-31

    A few epidemiological studies have linked exposure to electromagnetic fields (EMF) and the incidence of cancer. Since many carcinogens are mutagens in the Ames assay, the purpose of this study was to determine if exposure of four tester strains of Salmonella typhimurium (TA97a, TA98, TA100, and TA102) to EMF would increase their rate of mutation. Parallel plate electrodes and Helmholtz coils were used to create uniform field properties 300 coils were used to create uniform field properties (300 V/in., 0.3 mT). Separate and combined alternating electric and magnetic fields effects were studied at a combined field frequency of 60, 600, and 6000 Hz at room temperature. These fields did not elevate the temperature of the culture plates above room temperature. Petri dishes containing each tester strain in top agar were exposed to an electric field (E), magnetic field (M), combined electric and magnetic field (EM), or no additional field above ambient conditions in the lab (control). Four plates containing each strain were exposed in each condition: two plates had the appropriate positive-control mutagen for each strain included in the top agar and two plates did not. Plates were exposed to either E, M, EM, or control conditions at room temperature for 48 hr. and then incubated an additional 24 hr. at 37 deg. C. The plates containing mutagen in the top agar showed an increased number of colonies consistent with mutagenesis. However, the rate of mutation in the S. Typhimurium strains TA97a, TA98, TA100, and TA102 in either the presence or absence of mutagen was not affected by 48 hr. exposure at room temperature to E, M, or EM fields at 60, 600, 94 6000 Hz. 24 refs., 1 fig., 3 tabs.

  17. Insights from EMF Associated Agricultural and Forestry Greenhouse Gas Mitigation Studies

    SciTech Connect

    McCarl, Bruce A.; Murray, Brian; Kim, Man-Keun; Lee, Heng-Chi; Sands, Ronald D.; Schneider, Uwe

    2007-11-19

    Integrated assessment modeling (IAM) as employed by the Energy Modeling Forum (EMF) generally involves a multi-sector appraisal of greenhouse gas emission (GHGE) mitigation alternatives and climate change effects typically at the global level. Such a multi-sector evaluation encompasses potential climate change effects and mitigative actions within the agricultural and forestry (AF) sectors. In comparison with many of the other sectors covered by IAM, the AF sectors may require somewhat different treatment due to their critical dependence upon spatially and temporally varying resource and climatic conditions. In particular, in large countries like the United States, forest production conditions vary dramatically across the landscape. For example, some areas in the southern US present conditions favorable to production of fast growing, heat tolerant pine species, while more northern regions often favor slower-growing hardwood and softwood species. Moreover, some lands are currently not suitable for forest production (e.g., the arid western plains). Similarly, in agriculture, the US has areas where citrus and cotton can be grown and other areas where barley and wheat are more suitable. This diversity across the landscape causes differential GHGE mitigation potential in the face of climatic changes and/or responses to policy or price incentives. It is difficult for a reasonably sized global IAM system to reflect the full range of sub-national geographic AF production possibilities alluded to above. AF response in the face of climate change altered temperature precipitation regimes or mitigation incentives will likely involve region-specific shifts in land use and agricultural/forest production. This chapter addresses AF sectoral responses in climate change mitigation analysis. Specifically, we draw upon US-based studies of AF GHGE mitigation possibilities that incorporate sub-national detail drawing largely on a body of studies done by the authors in association with EMF activities. We discuss characteristics of AF sectoral responses that could be incorporated in future IAM efforts in climate change policy.

  18. Development of an RF-EMF Exposure Surrogate for Epidemiologic Research

    PubMed Central

    Roser, Katharina; Schoeni, Anna; Bürgi, Alfred; Röösli, Martin

    2015-01-01

    Exposure assessment is a crucial part in studying potential effects of RF-EMF. Using data from the HERMES study on adolescents, we developed an integrative exposure surrogate combining near-field and far-field RF-EMF exposure in a single brain and whole-body exposure measure. Contributions from far-field sources were modelled by propagation modelling and multivariable regression modelling using personal measurements. Contributions from near-field sources were assessed from both, questionnaires and mobile phone operator records. Mean cumulative brain and whole-body doses were 1559.7 mJ/kg and 339.9 mJ/kg per day, respectively. 98.4% of the brain dose originated from near-field sources, mainly from GSM mobile phone calls (93.1%) and from DECT phone calls (4.8%). Main contributors to the whole-body dose were GSM mobile phone calls (69.0%), use of computer, laptop and tablet connected to WLAN (12.2%) and data traffic on the mobile phone via WLAN (6.5%). The exposure from mobile phone base stations contributed 1.8% to the whole-body dose, while uplink exposure from other people’s mobile phones contributed 3.6%. In conclusion, the proposed approach is considered useful to combine near-field and far-field exposure to an integrative exposure surrogate for exposure assessment in epidemiologic studies. However, substantial uncertainties remain about exposure contributions from various near-field and far-field sources. PMID:26006132

  19. Absolute instability in a TWT

    NASA Astrophysics Data System (ADS)

    Lau, Y. Y.; Ang, L. K.

    1998-11-01

    There is renewed interest in the traveling wave tube (TWT) because of the recent advances in microwave power module (D. R. Whaley et al., IEEE Trans. Plasma Sci. 26, 912 (1998)) and of the significant growth in satellite communication. A serious threat to the operation of TWT is bandedge oscillation, occurring at the ?-mode of the slow wave circuit. A candidate for bandedge oscillation is the excitation of absolute instability. In this paper, we approximate the circuit mode by a parabola in the dispersion diagram (?-k plane). We use the Briggs-Bers criterion to determine the threshold value of C (C = Pierce parameter) for the onset of absolute instability. The stabilizing effect of a distributed resistive loss, and of velocity detune, is included. The differences in absolute instabilities between fast wave and slow wave devices are discussed.

  20. Achieving Climate Change Absolute Accuracy in Orbit

    NASA Technical Reports Server (NTRS)

    Wielicki, Bruce A.; Young, D. F.; Mlynczak, M. G.; Thome, K. J; Leroy, S.; Corliss, J.; Anderson, J. G.; Ao, C. O.; Bantges, R.; Best, F.; Bowman, K.; Brindley, H.; Butler, J. J.; Collins, W.; Dykema, J. A.; Doelling, D. R.; Feldman, D. R.; Fox, N.; Huang, X.; Holz, R.; Huang, Y.; Jennings, D.; Jin, Z.; Johnson, D. G.; Jucks, K.; Kato, S.; Kratz, D. P.; Liu, X.; Lukashin, C.; Mannucci, A. J.; Phojanamongkolkij, N.; Roithmayr, C. M.; Sandford, S.; Taylor, P. C.; Xiong, X.

    2013-01-01

    The Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission will provide a calibration laboratory in orbit for the purpose of accurately measuring and attributing climate change. CLARREO measurements establish new climate change benchmarks with high absolute radiometric accuracy and high statistical confidence across a wide range of essential climate variables. CLARREO's inherently high absolute accuracy will be verified and traceable on orbit to Système Internationale (SI) units. The benchmarks established by CLARREO will be critical for assessing changes in the Earth system and climate model predictive capabilities for decades into the future as society works to meet the challenge of optimizing strategies for mitigating and adapting to climate change. The CLARREO benchmarks are derived from measurements of the Earth's thermal infrared spectrum (5-50 micron), the spectrum of solar radiation reflected by the Earth and its atmosphere (320-2300 nm), and radio occultation refractivity from which accurate temperature profiles are derived. The mission has the ability to provide new spectral fingerprints of climate change, as well as to provide the first orbiting radiometer with accuracy sufficient to serve as the reference transfer standard for other space sensors, in essence serving as a "NIST [National Institute of Standards and Technology] in orbit." CLARREO will greatly improve the accuracy and relevance of a wide range of space-borne instruments for decadal climate change. Finally, CLARREO has developed new metrics and methods for determining the accuracy requirements of climate observations for a wide range of climate variables and uncertainty sources. These methods should be useful for improving our understanding of observing requirements for most climate change observations.

  1. Absolute transition probabilities of phosphorus.

    NASA Technical Reports Server (NTRS)

    Miller, M. H.; Roig, R. A.; Bengtson, R. D.

    1971-01-01

    Use of a gas-driven shock tube to measure the absolute strengths of 21 P I lines and 126 P II lines (from 3300 to 6900 A). Accuracy for prominent, isolated neutral and ionic lines is estimated to be 28 to 40% and 18 to 30%, respectively. The data and the corresponding theoretical predictions are examined for conformity with the sum rules.-

  2. Analysis of cell performance and thermal regeneration of a lithium-tin cell having an immobilized fused-salt electrolyte

    NASA Technical Reports Server (NTRS)

    Cairns, E. J.; Shimotake, H.

    1969-01-01

    Cell performance and thermal regeneration of a thermally regenerative cell uses lithium and tin and a fused-salt electrolyte. The emf of the Li-Sn cell, as a function of cathode-alloy composition, is shown to resemble that of the Na-Bi cell.

  3. Report on Toyota/Prius Motor Torque-Capability, Torque-Property, No-Load Back EMF, and Mechanical Losses

    SciTech Connect

    Hsu, J.S.

    2004-09-30

    In today's hybrid vehicle market, the Toyota Prius drive system is currently considered the leader in electrical, mechanical, and manufacturing innovations. It is significant that in today's marketplace, Toyota is able to manufacture and sell the vehicle for a profit. This project's objective is to test the torque capability of the 2004 Prius motor and to analyze the torque properties relating to the rotor structure. The tested values of no-load back electromotive force (emf) and mechanical losses are also presented.

  4. Thermodynamic properties of calcium-magnesium alloys determined by emf measurements

    SciTech Connect

    Newhouse, JM; Poizeau, S; Kim, H; Spatocco, BL; Sadoway, DR

    2013-02-28

    The thermodynamic properties of calcium-magnesium alloys were determined by electromotive force (emf) measurements using a Ca(in Bi)vertical bar CaF2 vertical bar Ca(in Mg) cell over the temperature range 713-1048 K. The activity and partial molar Gibbs free energy of calcium in magnesium were calculated for nine Ca-Mg alloys, calcium mole fractions varying from x(ca) = 0.01 to 0.80. Thermodynamic properties of magnesium in calcium and the molar Gibbs free energy of mixing were estimated using the Gibbs-Duhem relationship. In the all-liquid region at 1010 K, the activity of calcium in magnesium was found to range between 8.8 x 10(-4) and 0.94 versus pure calcium. The molecular interaction volume model (MIVM) was used to model the activity coefficient of Ca and Mg in Ca-Mg liquid alloys. Based on this work, Ca-Mg alloys show promise as the negative electrode of a liquid metal battery in which calcium is the itinerant species: alloying with Mg results in both a decrease in operating temperature and suppression of Ca metal solubility in the molten salt electrolyte. (C) 2012 Elsevier Ltd. All rights reserved.

  5. Absolute calibration of optical flats

    SciTech Connect

    Sommargren, Gary E.

    2005-04-05

    The invention uses the phase shifting diffraction interferometer (PSDI) to provide a true point-by-point measurement of absolute flatness over the surface of optical flats. Beams exiting the fiber optics in a PSDI have perfect spherical wavefronts. The measurement beam is reflected from the optical flat and passed through an auxiliary optic to then be combined with the reference beam on a CCD. The combined beams include phase errors due to both the optic under test and the auxiliary optic. Standard phase extraction algorithms are used to calculate this combined phase error. The optical flat is then removed from the system and the measurement fiber is moved to recombine the two beams. The newly combined beams include only the phase errors due to the auxiliary optic. When the second phase measurement is subtracted from the first phase measurement, the absolute phase error of the optical flat is obtained.

  6. Absolute pitch and planum temporale.

    PubMed

    Keenan, J P; Thangaraj, V; Halpern, A R; Schlaug, G

    2001-12-01

    An increased leftward asymmetry of the planum temporale (PT) in absolute-pitch (AP) musicians has been previously reported, with speculation that early exposure to music influences the degree of PT asymmetry. To test this hypothesis and to determine whether a larger left PT or a smaller right PT actually accounts for the increased overall PT asymmetry in AP musicians, anatomical magnetic resonance images were taken from a right-handed group of 27 AP musicians, 27 nonmusicians, and 22 non-AP musicians. A significantly greater leftward PT asymmetry and a significantly smaller right absolute PT size for the AP musicians compared to the two control groups was found, while the left PT was only marginally larger in the AP group. The absolute size of the right PT and not the left PT was a better predictor of music group membership, possibly indicating "pruning" of the right PT rather than expansion of the left underlying the increased PT asymmetry in AP musicians. Although early exposure to music may be a prerequisite for acquiring AP, the increased PT asymmetry in AP musicians may be determined in utero, implicating possible genetic influences on PT asymmetry. This may explain why the increased PT asymmetry of AP musicians was not seen in the group of early beginning non-AP musicians. PMID:11707095

  7. Specific features of the thermal electromotive force in Bi quantum wires in transverse magnetic and electric fields

    NASA Astrophysics Data System (ADS)

    Sinyavskii, E. P.; Solovenko, V. G.

    2014-11-01

    The thermal electromotive force (emf) in Bi quantum wires has been calculated in the model of potential in the form of a paraboloid of revolution in a uniform magnetic field H, which is normal to the axis of the studied nanostructure, and in a direct-current (dc) electric field E ? H. It has been shown that, with an increase in E, the thermal emf ?xx is described by a nonmonotonic function at different values of H. A physical interpretation of this behavior of ?xx as a function of E is proposed with account for the interaction between carriers and the rough surface of the nanowire.

  8. Absolute versus convective instability of spiral waves

    PubMed

    Sandstede; Scheel

    2000-12-01

    Absolute and convective instabilities of spirals are investigated using the continuous and the so-called absolute spectrum. It is shown that the nature of transport, induced by an absolute instability, is determined by spectral data of the asymptotic wave trains. The results are applied to core and far-field breakup of spiral waves in excitable and oscillatory media. PMID:11138042

  9. EPRI EMF exposure database: EMDEX occupational study data set. Final report

    SciTech Connect

    Senior, R.S.; Bracken, T.D.; Rankin, R.F.

    1996-10-01

    This document describes the EMDEX Occupational Study (EOS) Data Set containing the measurement data collected during the EPRI-sponsored study, Electric and Magnetic Field Measurement Study for Utilities - The EMDEX Project (RP2966-01). The data were supplied to the EPRI EMF Exposure Database by the original researchers at T. Dan Bracken, Inc. Electric and magnetic field exposure data were collected by volunteer employees at 55 utility sites. Volunteers were placed in one of sixteen job classifications depending on their job title and work environment. They maintained a simple logbook while wearing an EMDEX meter, allowing the measurement data to be identified with one of eight work environments or one of three non-work environments. The fourteen data products in the EMDEX Occupational Study Data Set contain the electric and magnetic field personal exposure measurements collected during the study and summaries of those measurements along with associated descriptive information. The exposure measurement data products consist of time-series and summary files. The former are the binary and ASCII time-series files of individual field measurements that contain both electric and magnetic field data. These time-series files represent over 28,800,000 individual field measurements. Separate summary files for electric and magnetic field measurements represent six levels of aggregation of the data. The documentation contains a project synopsis, full descriptions of all data elements, and the format and size of each data product. The final report for the project and other references are cited as sources of detailed information about study design, protocols, and results.

  10. Familial aggregation of absolute pitch.

    PubMed

    Baharloo, S; Service, S K; Risch, N; Gitschier, J; Freimer, N B

    2000-09-01

    Absolute pitch (AP) is a behavioral trait that is defined as the ability to identify the pitch of tones in the absence of a reference pitch. AP is an ideal phenotype for investigation of gene and environment interactions in the development of complex human behaviors. Individuals who score exceptionally well on formalized auditory tests of pitch perception are designated as "AP-1." As described in this report, auditory testing of siblings of AP-1 probands and of a control sample indicates that AP-1 aggregates in families. The implications of this finding for the mapping of loci for AP-1 predisposition are discussed. PMID:10924408

  11. Absolute calibration of optical tweezers

    SciTech Connect

    Viana, N.B.; Mazolli, A.; Maia Neto, P.A.; Nussenzveig, H.M.; Rocha, M.S.; Mesquita, O.N.

    2006-03-27

    As a step toward absolute calibration of optical tweezers, a first-principles theory of trapping forces with no adjustable parameters, corrected for spherical aberration, is experimentally tested. Employing two very different setups, we find generally very good agreement for the transverse trap stiffness as a function of microsphere radius for a broad range of radii, including the values employed in practice, and at different sample chamber depths. The domain of validity of the WKB ('geometrical optics') approximation to the theory is verified. Theoretical predictions for the trapping threshold, peak position, depth variation, multiple equilibria, and 'jump' effects are also confirmed.

  12. Absolute calibration of optical tweezers

    NASA Astrophysics Data System (ADS)

    Viana, N. B.; Mazolli, A.; Maia Neto, P. A.; Nussenzveig, H. M.; Rocha, M. S.; Mesquita, O. N.

    2006-03-01

    As a step toward absolute calibration of optical tweezers, a first-principles theory of trapping forces with no adjustable parameters, corrected for spherical aberration, is experimentally tested. Employing two very different setups, we find generally very good agreement for the transverse trap stiffness as a function of microsphere radius for a broad range of radii, including the values employed in practice, and at different sample chamber depths. The domain of validity of the WKB ("geometrical optics") approximation to the theory is verified. Theoretical predictions for the trapping threshold, peak position, depth variation, multiple equilibria, and "jump" effects are also confirmed.

  13. Geologic application of thermal-inertia mapping from satellite. [Arizona and Powder River, Wyoming

    NASA Technical Reports Server (NTRS)

    Offield, T. W. (principal investigator); Miller, S. H.; Watson, K.

    1978-01-01

    The author has identified the following significant results. A theoretical evaluation of the proportional and linear relationship between absolute and relative thermal inertia was performed, and a potentially more accurate expression for absolute thermal inertia mapping was proposed.

  14. The amelioration of phagocytic ability in microglial cells by curcumin through the inhibition of EMF-induced pro-inflammatory responses

    PubMed Central

    2014-01-01

    Background Insufficient clearance by microglial cells, prevalent in several neurological conditions and diseases, is intricately intertwined with MFG-E8 expression and inflammatory responses. Electromagnetic field (EMF) exposure can elicit the pro-inflammatory activation and may also trigger an alteration of the clearance function in microglial cells. Curcumin has important roles in the anti-inflammatory and phagocytic process. Here, we evaluated the ability of curcumin to ameliorate the phagocytic ability of EMF-exposed microglial cells (N9 cells) and documented relative pathways. Methods N9 cells were pretreated with or without recombinant murine MFG-E8 (rmMFG-E8), curcumin and an antibody of toll-like receptor 4 (anti-TLR4), and subsequently treated with EMF or a sham exposure. Their phagocytic ability was evaluated using phosphatidylserine-containing fluorescent bioparticles. The pro-inflammatory activation of microglia was assessed via CD11b immunoreactivity and the production of tumor necrosis factor-? (TNF-?), interleukin-6 (IL-6), interleukin-1? (IL-1?) and nitric oxide (NO) via the enzyme-linked immunosorbent assay or the Griess test. We evaluated the ability of curcumin to ameliorate the phagocytic ability of EMF-exposed N9 cells, including checking the expression of MFG-E8, ?v?3 integrin, TLR4, nuclear factor-?B (NF-?B) and signal transducer and activator of transcription 3 (STAT3) using Western blotting. Results EMF exposure dramatically enhanced the expression of CD11b and depressed the phagocytic ability of N9 cells. rmMFG-E8 could clearly ameliorate the phagocytic ability of N9 cells after EMF exposure. We also found that EMF exposure significantly increased the secretion of pro-inflammatory cytokines (TNF-?, IL-6 and IL-1?) and the production of NO; however, these increases were efficiently chilled by the addition of curcumin to the culture medium. This reduction led to the amelioration of the phagocytic ability of EMF-exposed N9 cells. Western blot analysis revealed that curcumin and naloxone restored the expression of MFG-E8 but had no effect on TLR4 and cytosolic STAT3. Moreover, curcumin significantly reduced the expression of NF-?B p65 in nuclei and phospho-STAT3 (p-STAT3) in cytosols and nuclei. Conclusions This study indicates that curcumin ameliorates the depressed MFG-E8 expression and the attenuated phagocytic ability of EMF-exposed N9 cells, which is attributable to the inhibition of the pro-inflammatory response through the NF-?B and STAT3 pathways. PMID:24645646

  15. An absolute Johnson noise thermometer

    E-print Network

    Luca Callegaro; Vincenzo D'Elia; Marco Pisani; Alessio Pollarolo

    2009-01-30

    We developed an absolute Johnson noise thermometer (JNT), an instrument to measure the thermodynamic temperature of a sensing resistor, with traceability to voltage, resistance and frequency quantities. The temperature is measured in energy units, and can be converted to SI units (kelvin) with the accepted value of the Boltzmann constant kb; or, conversely, it can be employed to perform measurements at the triple point of water, and obtain a determination of kb. The thermometer is composed of a correlation spectrum analyzer an a calibrated noise source, both constructed around commercial mixed-signal boards. The calibrator generates a pseudorandom noise, by digital synthesis and amplitude scaling with inductive voltage dividers; the signal spectrum is a frequency comb covering the measurement bandwidth. JNT measurements at room temperature are compatible with those of a standard platinum resistance thermometer within the combined uncertainty of 60 ppm. A path towards future improvements of JNT accuracy is also sketched.

  16. "Absolute" sterility and "absolute" freedom from particle contamination.

    PubMed

    Knapp, J Z

    1998-01-01

    Until the recent past, sterility of an injectable product was only discussed in absolute terms. Any description of sterility other than as an absolute could simply not be envisioned. While dealing in absolute yes/no statements is philosophically satisfying, these yes/no statements can't accommodate all real world scientific problems. Among these problems is the sterility problems faced in the mass production of injectable compounds. Many descriptions of procedures employed to achieve sterility in parenteral production batches were reported in the literature. The theoretical framework that could unite the widespread observations and practices into practical methodology was missing until recently. Production line control of the sterility of injectable products was essentially based on gut evaluations. The present achievement of rational, production line control of product sterility is based on the recognition that product sterility could not be simply regarded as a sharply edged yes/no affair. The present rational control is based on the fact that the sterility of a product is determined by the degree of contamination in the product prior to sterilization and to the parameters of the sterilization process. The end result of the sterilization process is now described as a probabalistic reduction of the initial contamination. The essential laboratory measurements on which this conclusion was based is due to Pflug (1-3). He assembled a theoretical framework, based on experimental data, that characterizes the sterility achieved in an injectable product with a single number. The end result of the sterilization process is now described as a probabalistic reduction of the initial contamination. As in many disciplines, the ability to achieve an objective evaluation of this important attribute provided the basis for scientific analysis, improved control and thus improved production and reduced cost. An equivalent framework is essential for the communication and standardization of the results of a visual inspection for contaminating particles. The control of particle contamination in injectable products is a two-fold problem for the pharmaceutical industry. The two parts of the problem are 1) achieving contamination free product and 2) achieving this contamination free quality at an economic cost acceptable to the user. Today, there is no commonly accepted framework for the definition or analysis of the results of a manual inspection for "visible" particles. Any progress toward global harmonization of the results of a visual particle inspection must commence with the development of a common scientific language with which inspection security and economic effectiveness of an inspection can be discussed and rationally evaluated. The tools with which to define and control the results of this inspection have been developed in biophysics, illumination engineering, optics, pharmaceutical manufacturing and statistics. With them, statistically replicable measures have been developed. The statistically replicable measures are then used to evaluate the results of semi- and fully automated particle inspection systems in terms of human inspection performance. The numerical evaluation of both the freedom from contamination achieved with an inspection for particle contamination and the economic effectiveness of the inspection are compared to Pflug's sterility index. In the case of particle contamination, the final product quality depends on product quality prior to inspection and to the parameters of the inspection process. PMID:9752713

  17. Safety of high speed guided ground transportation systems: Review of existing EMF guidelines, standards and regulations. Final report, January-June 1993

    SciTech Connect

    Goellner, D.; Wilson, B.; Reiter, R.; Pilla, A.; Hankin, N.

    1993-08-01

    Although there are no maglev or other advanced high-speed rail systems currently operating in the United States, EMF exposure is still of concern as it relates top 60 hertz (Hz) power transmission and distribution lines and electrical appliances. The report provides information on existing and proposed EMF guidelines, standards and regulations at the international, national, state, and local levels. It covers fields in the frequency range of 0-100 Ghz and includes EMF exposures for both the general public and workers. Whereas the above frequency range includes radio frequencies and microwave frequencies, the main focus for the United States is on extremely low frequencies (ELF), such as those associated with the use of electric power. However, there is some discussion of regulation of higher frequency ranges in other countries.

  18. qEMF3, a novel QTL for the early-morning flowering trait from wild rice, Oryza officinalis, to mitigate heat stress damage at flowering in rice, O. sativa.

    PubMed

    Hirabayashi, Hideyuki; Sasaki, Kazuhiro; Kambe, Takashi; Gannaban, Ritchel B; Miras, Monaliza A; Mendioro, Merlyn S; Simon, Eliza V; Lumanglas, Patrick D; Fujita, Daisuke; Takemoto-Kuno, Yoko; Takeuchi, Yoshinobu; Kaji, Ryota; Kondo, Motohiko; Kobayashi, Nobuya; Ogawa, Tsugufumi; Ando, Ikuo; Jagadish, Krishna S V; Ishimaru, Tsutomu

    2015-03-01

    A decline in rice (Oryza sativa L.) production caused by heat stress is one of the biggest concerns resulting from future climate change. Rice spikelets are most susceptible to heat stress at flowering. The early-morning flowering (EMF) trait mitigates heat-induced spikelet sterility at the flowering stage by escaping heat stress during the daytime. We attempted to develop near-isogenic lines (NILs) for EMF in the indica-type genetic background by exploiting the EMF locus from wild rice, O. officinalis (CC genome). A stable quantitative trait locus (QTL) for flower opening time (FOT) was detected on chromosome 3. A QTL was designated as qEMF3 and it shifted FOT by 1.5-2.0 h earlier for cv. Nanjing 11 in temperate Japan and cv. IR64 in the Philippine tropics. NILs for EMF mitigated heat-induced spikelet sterility under elevated temperature conditions completing flower opening before reaching 35°C, a general threshold value leading to spikelet sterility. Quantification of FOT of cultivars popular in the tropics and subtropics did not reveal the EMF trait in any of the cultivars tested, suggesting that qEMF3 has the potential to advance FOT of currently popular cultivars to escape heat stress at flowering under future hotter climates. This is the first report to examine rice with the EMF trait through marker-assisted breeding using wild rice as a genetic resource. PMID:25534925

  19. qEMF3, a novel QTL for the early-morning flowering trait from wild rice, Oryza officinalis, to mitigate heat stress damage at flowering in rice, O. sativa

    PubMed Central

    Hirabayashi, Hideyuki; Sasaki, Kazuhiro; Kambe, Takashi; Gannaban, Ritchel B.; Miras, Monaliza A.; Mendioro, Merlyn S.; Simon, Eliza V.; Lumanglas, Patrick D.; Fujita, Daisuke; Takemoto-Kuno, Yoko; Takeuchi, Yoshinobu; Kaji, Ryota; Kondo, Motohiko; Kobayashi, Nobuya; Ogawa, Tsugufumi; Ando, Ikuo; Jagadish, Krishna S. V.; Ishimaru, Tsutomu

    2015-01-01

    A decline in rice (Oryza sativa L.) production caused by heat stress is one of the biggest concerns resulting from future climate change. Rice spikelets are most susceptible to heat stress at flowering. The early-morning flowering (EMF) trait mitigates heat-induced spikelet sterility at the flowering stage by escaping heat stress during the daytime. We attempted to develop near-isogenic lines (NILs) for EMF in the indica-type genetic background by exploiting the EMF locus from wild rice, O. officinalis (CC genome). A stable quantitative trait locus (QTL) for flower opening time (FOT) was detected on chromosome 3. A QTL was designated as qEMF3 and it shifted FOT by 1.5–2.0h earlier for cv. Nanjing 11 in temperate Japan and cv. IR64 in the Philippine tropics. NILs for EMF mitigated heat-induced spikelet sterility under elevated temperature conditions completing flower opening before reaching 35°C, a general threshold value leading to spikelet sterility. Quantification of FOT of cultivars popular in the tropics and subtropics did not reveal the EMF trait in any of the cultivars tested, suggesting that qEMF3 has the potential to advance FOT of currently popular cultivars to escape heat stress at flowering under future hotter climates. This is the first report to examine rice with the EMF trait through marker-assisted breeding using wild rice as a genetic resource. PMID:25534925

  20. Divertissement 4: Absolute Temperature From Thermodynamics

    E-print Network

    Ronis, David M.

    Divertissement 4: Absolute Temperature From Thermodynamics (North Holland, 1976) Ryogo Kubo by a thermodynamic method so that it does not depend on the choice of thermometric substance, the zero of the scale being defined as the lowest temperature which is possible thermodynamically. Absolute temperature, which

  1. Absolute optical metrology : nanometers to kilometers

    NASA Technical Reports Server (NTRS)

    Dubovitsky, Serge; Lay, O. P.; Peters, R. D.; Liebe, C. C.

    2005-01-01

    We provide and overview of the developments in the field of high-accuracy absolute optical metrology with emphasis on space-based applications. Specific work on the Modulation Sideband Technology for Absolute Ranging (MSTAR) sensor is described along with novel applications of the sensor.

  2. Absolute instabilities of standing pulses Bjorn Sandstede

    E-print Network

    Scheel, Arnd

    Absolute instabilities of standing pulses Bj¨orn Sandstede Department of Mathematics The Ohio State-diffusion systems that are caused by an absolute instability of the homogeneous background state. Specifically, we renders the instability convective in nature [18, 19]: Even though perturbations grow in overall amplitude

  3. Inequalities, Absolute Value, and Logical Connectives.

    ERIC Educational Resources Information Center

    Parish, Charles R.

    1992-01-01

    Presents an approach to the concept of absolute value that alleviates students' problems with the traditional definition and the use of logical connectives in solving related problems. Uses a model that maps numbers from a horizontal number line to a vertical ray originating from the origin. Provides examples solving absolute value equations and…

  4. Introducing the Mean Absolute Deviation "Effect" Size

    ERIC Educational Resources Information Center

    Gorard, Stephen

    2015-01-01

    This paper revisits the use of effect sizes in the analysis of experimental and similar results, and reminds readers of the relative advantages of the mean absolute deviation as a measure of variation, as opposed to the more complex standard deviation. The mean absolute deviation is easier to use and understand, and more tolerant of extreme…

  5. Absolute Income, Relative Income, and Happiness

    ERIC Educational Resources Information Center

    Ball, Richard; Chernova, Kateryna

    2008-01-01

    This paper uses data from the World Values Survey to investigate how an individual's self-reported happiness is related to (i) the level of her income in absolute terms, and (ii) the level of her income relative to other people in her country. The main findings are that (i) both absolute and relative income are positively and significantly…

  6. Quantum nonequilibrium equalities with absolute irreversibility

    NASA Astrophysics Data System (ADS)

    Funo, Ken; Murashita, Yûto; Ueda, Masahito

    2015-07-01

    We derive quantum nonequilibrium equalities in absolutely irreversible processes. Here by absolute irreversibility we mean that in the backward process the density matrix does not return to the subspace spanned by those eigenvectors that have nonzero weight in the initial density matrix. Since the initial state of a memory and the postmeasurement state of the system are usually restricted to a subspace, absolute irreversibility occurs during the measurement and feedback processes. An additional entropy produced in absolutely irreversible processes needs to be taken into account to derive nonequilibrium equalities. We discuss a model of a feedback control on a qubit system to illustrate the obtained equalities. By introducing N heat baths each composed of a qubit and letting them interact with the system, we show how the entropy reduction via feedback control can be converted into work. An explicit form of extractable work in the presence of absolute irreversibility is given.

  7. Absolute efficiency measurements with the 10B based Jalousie detector

    NASA Astrophysics Data System (ADS)

    Modzel, G.; Henske, M.; Houben, A.; Klein, M.; Köhli, M.; Lennert, P.; Meven, M.; Schmidt, C. J.; Schmidt, U.; Schweika, W.

    2014-04-01

    The 10B based Jalousie detector is a replacement for 3He counter tubes, which are nowadays less affordable for large area detectors due to the 3He crisis. In this paper we investigate and verify the performance of the new 10B based detector concept and its adoption for the POWTEX diffractometer, which is designed for the detection of thermal neutrons with predicted detection efficiencies of 75-50% for neutron energies of 10-100 meV, respectively. The predicted detection efficiency has been verified by absolute measurements using neutrons with a wavelength of 1.17 Å (59 meV).

  8. Ge/Si(001) heterostructures with dense arrays of Ge quantum dots: morphology, defects, photo-emf spectra and terahertz conductivity

    E-print Network

    Yuryev, V A; Storozhevykh, M S; Chapnin, V A; Chizh, K V; Uvarov, O V; Kalinushkin, V P; Zhukova, E S; Prokhorov, A S; Spektor, I E; Gorshunov, B P

    2012-01-01

    Issues of Ge hut array formation and growth at low temperatures on the Ge/Si(001) wetting layer are discussed on the basis of explorations performed by high resolution STM and in-situ RHEED. Data of HRTEM studies of multilayer Ge/Si heterostructures are presented with the focus on low-temperature formation of perfect films. Heteroepitaxial Si p-i-n-diodes with multilayer stacks of Ge/Si(001) quantum dot dense arrays built in intrinsic domains have been investigated and found to exhibit the photo-emf in a wide spectral range from 0.8 to 5 mcm. An effect of wide-band irradiation by infrared light on the photo-emf spectra has been observed. Photo-emf in different spectral ranges has been found to be differently affected by the wide-band irradiation. A significant increase in photo-emf is observed in the fundamental absorption range under the wide-band irradiation. The observed phenomena are explained in terms of positive and neutral charge states of the quantum dot layers and the Coulomb potential of the quantum...

  9. Inter-individual and intra-individual variation of the effects of pulsed RF EMF exposure on the human sleep EEG.

    PubMed

    Lustenberger, Caroline; Murbach, Manuel; Tüshaus, Laura; Wehrle, Flavia; Kuster, Niels; Achermann, Peter; Huber, Reto

    2015-04-01

    Pulse-modulated radiofrequency electromagnetic fields (RF EMF) can alter brain activity during sleep; increases of electroencephalographic (EEG) power in the sleep spindle (13.75-15.25?Hz) and delta-theta (1.25-9?Hz) frequency range have been reported. These field effects show striking inter-individual differences. However, it is still unknown whether individual subjects react in a similar way when repeatedly exposed. Thus, our study aimed to investigate inter-individual variation and intra-individual stability of field effects. To do so, we exposed 20 young male subjects twice for 30?min prior to sleep to the same amplitude modulated 900?MHz (2?Hz pulse, 20?Hz Gaussian low-pass filter and a ratio of peak-to-average of 4) RF EMF (spatial peak absorption of 2?W/kg averaged over 10?g) 2 weeks apart. The topographical analysis of EEG power during all-night non-rapid eye movement sleep revealed: (1) exposure-related increases in delta-theta frequency range in several fronto-central electrodes; and (2) no differences in spindle frequency range. We did not observe reproducible within-subject RF EMF effects on sleep spindle and delta-theta activity in the sleep EEG and it remains unclear whether a biological trait of how the subjects' brains react to RF EMF exists. PMID:25690404

  10. Harmonics of the emf of superposed transducers in local magnetization of specimens by inhomogeneous constant magnetic field of rod-shaped electromagnet

    SciTech Connect

    Zatsepin, N.N.; Gusak, N.O.; Chernyshev, A.V.

    1988-10-01

    An experimental study was made of the higher harmonic components of the emf of a superposed transducer in quasistatic increase and decrease of the intensity of a local magnetic field induced by a rod-shaped electromagnet. The obtained dependences based on the phenomenon of the lead of remagnetization of the upper layers of a ferromagnet are explained.

  11. Absolute optical instruments without spherical symmetry

    NASA Astrophysics Data System (ADS)

    Tyc, Tomáš; Dao, H. L.; Danner, Aaron J.

    2015-11-01

    Until now, the known set of absolute optical instruments has been limited to those containing high levels of symmetry. Here, we demonstrate a method of mathematically constructing refractive index profiles that result in asymmetric absolute optical instruments. The method is based on the analogy between geometrical optics and classical mechanics and employs Lagrangians that separate in Cartesian coordinates. In addition, our method can be used to construct the index profiles of most previously known absolute optical instruments, as well as infinitely many different ones.

  12. On determining absolute entropy without quantum theory or the Third Law of thermodynamics

    E-print Network

    Steane, Andrew

    2015-01-01

    We employ classical thermodynamics to gain information about absolute entropy, without recourse to statistical methods, quantum mechanics or the Third Law of thermodynamics. The Gibbs-Duhem equation yields various simple methods to determine the absolute entropy of a fluid. We also study the entropy of an ideal gas and the ionization of a plasma in thermal equilibrium. A single measurement of the degree of ionization can be used to determine an unknown constant in the entropy equation, and thus determine the absolute entropy of a gas. It follows from all these examples that the value of entropy at absolute zero temperature does not need to be assigned by postulate, but can be deduced empirically.

  13. Absolute vs. intensity-based emission caps

    E-print Network

    Ellerman, A. Denny.

    Cap-and-trade systems limit emissions to some pre-specified absolute quantity. Intensity-based limits, that restrict emissions to some pre-specified rate relative to input or output, are much more widely used in environmental ...

  14. New absolute magnitude calibrations for detached binaries

    E-print Network

    S. Bilir; T. Ak; E. Soydugan; F. Soydugan; E. Yaz; N. Filiz Ak; Z. Eker; O. Demircan; M. Helvaci

    2008-06-07

    Lutz-Kelker bias corrected absolute magnitude calibrations for the detached binary systems with main-sequence components are presented. The absolute magnitudes of the calibrator stars were derived at intrinsic colours of Johnson-Cousins and 2MASS (Two Micron All Sky Survey) photometric systems. As for the calibrator stars, 44 detached binaries were selected from the Hipparcos catalogue, which have relative observed parallax errors smaller than 15% ($\\sigma_{\\pi}/\\pi\\leq0.15$). The calibration equations which provide the corrected absolute magnitude for optical and near-infrared pass bands are valid for wide ranges of colours and absolute magnitudes: $-0.18magnitude calibrations of this study can be used as a convenient statistical tool to estimate the true distances of detached binaries out of Hipparcos' distance limit.

  15. Magnifying absolute instruments for optically homogeneous regions

    SciTech Connect

    Tyc, Tomas

    2011-09-15

    We propose a class of magnifying absolute optical instruments with a positive isotropic refractive index. They create magnified stigmatic images, either virtual or real, of optically homogeneous three-dimensional spatial regions within geometrical optics.

  16. Absolutely uniform illumination of laser fusion pellets

    NASA Astrophysics Data System (ADS)

    Schmitt, A. J.

    1984-02-01

    Absolutely uniform illumination of spherical laser fusion pellets is possible when the energy deposition from a single laser beam is given by a simple cos 3 theta distribution. Conditions can be derived for which the laser beam targeting angles allow this absolute illumination uniformity. Configurations based upon the cube and higher order Platonic solids satisfy the constraints, as well as an infinite class of other less symmetric configurations.

  17. Image processing of thermal infrared images

    SciTech Connect

    Schott, J.R. )

    1989-09-01

    Techniques for digital processing of thermal infrared images are addressed. In particular, techniques that are uniquely required for thermal imagery are emphasized. This includes a treatment of how to implement absolute temperature calibration algorithms, methods for registering and combining multiple thermal infrared images, and methods for combining thermal infrared reflected visible and near-infrared data. In addition, the characteristics and methods for analysis of apparent thermal inertia images and thermal infrared multispectral images are treated. 25 refs.

  18. Universal Cosmic Absolute and Modern Science

    NASA Astrophysics Data System (ADS)

    Kostro, Ludwik

    The official Sciences, especially all natural sciences, respect in their researches the principle of methodic naturalism i.e. they consider all phenomena as entirely natural and therefore in their scientific explanations they do never adduce or cite supernatural entities and forces. The purpose of this paper is to show that Modern Science has its own self-existent, self-acting, and self-sufficient Natural All-in Being or Omni-Being i.e. the entire Nature as a Whole that justifies the scientific methodic naturalism. Since this Natural All-in Being is one and only It should be considered as the own scientifically justified Natural Absolute of Science and should be called, in my opinion, the Universal Cosmic Absolute of Modern Science. It will be also shown that the Universal Cosmic Absolute is ontologically enormously stratified and is in its ultimate i.e. in its most fundamental stratum trans-reistic and trans-personal. It means that in its basic stratum. It is neither a Thing or a Person although It contains in Itself all things and persons with all other sentient and conscious individuals as well, On the turn of the 20th century the Science has begun to look for a theory of everything, for a final theory, for a master theory. In my opinion the natural Universal Cosmic Absolute will constitute in such a theory the radical all penetrating Ultimate Basic Reality and will substitute step by step the traditional supernatural personal Absolute.

  19. Numerous Sinusoidal and Other EMF Phenomena, At Present and Former Native American Sites, May Be Superimposing Themselves onto Regional Power Grids.

    NASA Astrophysics Data System (ADS)

    Cadran, Lawrence R.; Mc Leod, Roger D.; Mc Leod, David M.

    2003-10-01

    Periodic electromagnetic field signals (EMF), sometimes noticeable as faint blue-light or other phenomena, frequently are also detected at sites associated with Native Americans. We first noticed this sort of information in the vicinity of Wendell, MA about fourteen years ago. Similar and other signals are apparent at Americas Stonehenge, AS, in North Salem, NH. Connecticut provided our first evidence of superposition of two such waves at the Gungywamp site north of Groton, CT. A Maine location first showed orthogonally oriented trajectories in neighborhoods formerly frequented by Molocket and Metallak and their relatives near Rumford and Rangeley, ME. Florida exhibits similar signals in the vicinity of Hollywood and at Miamis Tequesta instrument, as does a separate site in CT. Powerful thunderstorms in the vicinity of a stone serpent effigy in Ohio cause EMF pulsations. Such signals are possibly superimposing themselves onto power-grids, where frequency changes and system instabilities may occur, according to the elementary physics involved.

  20. Comments on absolute and convective instabilities

    SciTech Connect

    Ram, A.K.; Bers, A.

    1992-01-24

    >Absolute or convective evolutions of instabilities can produce very different signatures of observed radiation from unstable plasmas. This is particularly useful in space plasmas when correlating experimentally observed emissions with theoretical models describing the source regions. A letter has questioned the basis and usefulness of the theory of absolute and convective instabilities by using some singular examples. The arguments put forth by these authors, based upon their singular examples, are misleading. Furthermore, the notion of a time-asymptotic limit is treated in an imprecise manner by these authors. Here, the authors point out the misconceptions in the arguments put forth by Oscarsson and Roennmark (1986) that question the validity and usefulness of the well-known theory of absolute and convective instabilities. The solid basis of the well-known theory is clarified.

  1. Report on Toyota/Prius Motor Torque Capability, Torque Property, No-Load Back EMF, and Mechanical Losses, Revised May 2007

    SciTech Connect

    Hsu, J.S.; Ayers, C.W.; Coomer, C.L.; Wiles, R.H.; Burress, T.A.; Campbell, S.L.; Lowe, K.T.; Michelhaugh, R.T.

    2007-05-31

    In today's hybrid vehicle market, the Toyota/Prius drive system is currently considered the leader in electrical, mechanical, and manufacturing innovations. It is significant that in today's marketplace, Toyota is able to manufacture and sell the vehicle for a profit. This project's objective is to test the torque capability of the 2004 Prius motor and to analyze the torque properties relating to the rotor structure. The tested values of no-load back electromotive force (emf) and mechanical losses are also presented.

  2. Landsat-7 ETM+ radiometric stability and absolute calibration

    USGS Publications Warehouse

    Markham, B.L.; Barker, J.L.; Barsi, J.A.; Kaita, E.; Thome, K.J.; Helder, D.L.; Palluconi, Frank Don; Schott, J.R.; Scaramuzza, P.

    2002-01-01

    Launched in April 1999, the Landsat-7 ETM+ instrument is in its fourth year of operation. The quality of the acquired calibrated imagery continues to be high, especially with respect to its three most important radiometric performance parameters: reflective band instrument stability to better than ??1%, reflective band absolute calibration to better than ??5%, and thermal band absolute calibration to better than ??0.6 K. The ETM+ instrument has been the most stable of any of the Landsat instruments, in both the reflective and thermal channels. To date, the best on-board calibration source for the reflective bands has been the Full Aperture Solar Calibrator, which has indicated changes of at most -1.8% to -2.0% (95% C.I.) change per year in the ETM+ gain (band 4). However, this change is believed to be caused by changes in the solar diffuser panel, as opposed to a change in the instrument's gain. This belief is based partially on ground observations, which bound the changes in gain in band 4 at -0.7% to +1.5%. Also, ETM+ stability is indicated by the monitoring of desert targets. These image-based results for four Saharan and Arabian sites, for a collection of 35 scenes over the three years since launch, bound the gain change at -0.7% to +0.5% in band 4. Thermal calibration from ground observations revealed an offset error of +0.31 W/m 2 sr um soon after launch. This offset was corrected within the U. S. ground processing system at EROS Data Center on 21-Dec-00, and since then, the band 6 on-board calibration has indicated changes of at most +0.02% to +0.04% (95% C.I.) per year. The latest ground observations have detected no remaining offset error with an RMS error of ??0.6 K. The stability and absolute calibration of the Landsat-7 ETM+ sensor make it an ideal candidate to be used as a reference source for radiometric cross-calibrating to other land remote sensing satellite systems.

  3. Absolute Distance Measurement with the MSTAR Sensor

    NASA Technical Reports Server (NTRS)

    Lay, Oliver P.; Dubovitsky, Serge; Peters, Robert; Burger, Johan; Ahn, Seh-Won; Steier, William H.; Fetterman, Harrold R.; Chang, Yian

    2003-01-01

    The MSTAR sensor (Modulation Sideband Technology for Absolute Ranging) is a new system for measuring absolute distance, capable of resolving the integer cycle ambiguity of standard interferometers, and making it possible to measure distance with sub-nanometer accuracy. The sensor uses a single laser in conjunction with fast phase modulators and low frequency detectors. We describe the design of the system - the principle of operation, the metrology source, beamlaunching optics, and signal processing - and show results for target distances up to 1 meter. We then demonstrate how the system can be scaled to kilometer-scale distances.

  4. Does Exposure to a Radiofrequency Electromagnetic Field Modify Thermal Preference in Juvenile Rats?

    PubMed Central

    Pelletier, Amandine; Delanaud, Stéphane; de Seze, René; Bach, Véronique; Libert, Jean-Pierre; Loos, Nathalie

    2014-01-01

    Some studies have shown that people living near a mobile phone base station may report sleep disturbances and discomfort. Using a rat model, we have previously shown that chronic exposure to a low-intensity radiofrequency electromagnetic field (RF-EMF) was associated with paradoxical sleep (PS) fragmentation and greater vasomotor tone in the tail. Here, we sought to establish whether sleep disturbances might result from the disturbance of thermoregulatory processes by a RF-EMF. We recorded thermal preference and sleep stage distribution in 18 young male Wistar rats. Nine animals were exposed to a low-intensity RF-EMF (900 MHz, 1 V.m?1) for five weeks and nine served as non-exposed controls. Thermal preference was assessed in an experimental chamber comprising three interconnected compartments, in which the air temperatures (Ta) were set to 24°C, 28°C and 31°C. Sleep and tail skin temperature were also recorded. Our results indicated that relative to control group, exposure to RF-EMF at 31°C was associated with a significantly lower tail skin temperature (?1.6°C) which confirmed previous data. During the light period, the exposed group preferred to sleep at Ta?=?31°C and the controls preferred Ta?=?28°C. The mean sleep duration in exposed group was significantly greater (by 15.5%) than in control group (due in turn to a significantly greater amount of slow wave sleep (SWS, +14.6%). Similarly, frequency of SWS was greater in exposed group (by 4.9 episodes.h?1). The PS did not differ significantly between the two groups. During the dark period, there were no significant intergroup differences. We conclude that RF-EMF exposure induced a shift in thermal preference towards higher temperatures. The shift in preferred temperature might result from a cold thermal sensation. The change in sleep stage distribution may involve signals from thermoreceptors in the skin. Modulation of SWS may be a protective adaptation in response to RF-EMF exposure. PMID:24905635

  5. Direct observation of solidification microstructures around absolute stability

    SciTech Connect

    Ludwig, A.; Kurz, W.

    1996-09-01

    This paper presents, for the first time, experimental evidence for absolute stability in a transparent alloy. The succinonitrile-argon system was used to investigate the morphological transition from a cellular to a planar solid-liquid interface at high solidification velocities. Directional solidification of the organic contained in thin capillary tubes was observed in situ with an optical microscope. At the maximum interface velocity of 1.5 mm/s, a reduction of the solute content of the alloy resulted in a morphological transition from a cellular to a planar growth front. This transition developed in three stages: (1) transition from deep cylindrical cells to mixed patterns of cylindrical and elongated cells; (ii) transition from cylindrical and elongated cells to low amplitude cells; (iii) transition from low amplitude cells to plane front. Within the limits of uncertainties with respect to the material properties and the thermal gradient, correspondence between the experimental results on plane front transition and linear stability theory exists. It is shown that the transitions observed are located in the region near the limit point of the neutral stability curve on the branch for absolute morphological stability.

  6. Absolute Points for Multiple Assignment Problems

    ERIC Educational Resources Information Center

    Adlakha, V.; Kowalski, K.

    2006-01-01

    An algorithm is presented to solve multiple assignment problems in which a cost is incurred only when an assignment is made at a given cell. The proposed method recursively searches for single/group absolute points to identify cells that must be loaded in any optimal solution. Unlike other methods, the first solution is the optimal solution. The…

  7. The Absolute Normal Scores Test for Symmetry

    ERIC Educational Resources Information Center

    Penfield, Douglas A.; Sachdeva, Darshan

    1976-01-01

    The absolute normal scores test is described as a test for the symmetry of a distribution of scores about a location parameter. The test is compared to the sign test and the Wilcoxon test as an alternative to the "t"-test. (Editor/RK)

  8. On Relative and Absolute Conviction in Mathematics

    ERIC Educational Resources Information Center

    Weber, Keith; Mejia-Ramos, Juan Pablo

    2015-01-01

    Conviction is a central construct in mathematics education research on justification and proof. In this paper, we claim that it is important to distinguish between absolute conviction and relative conviction. We argue that researchers in mathematics education frequently have not done so and this has lead to researchers making unwarranted claims…

  9. Multiverse Set Theory and Absolutely Undecidable Propositions

    E-print Network

    Väänänen, Jouko

    Multiverse Set Theory and Absolutely Undecidable Propositions Jouko V¨a¨an¨anen University of Helsinki and University of Amsterdam Contents 1 Introduction 2 2 Background 4 3 The multiverse of sets 6 3.1 The one universe case . . . . . . . . . . . . . . . . . . . . . . . . 6 3.2 The multiverse

  10. Absolute partial photoionization cross sections of ozone.

    SciTech Connect

    Berkowitz, J.; Chemistry

    2008-04-01

    Despite the current concerns about ozone, absolute partial photoionization cross sections for this molecule in the vacuum ultraviolet (valence) region have been unavailable. By eclectic re-evaluation of old/new data and plausible assumptions, such cross sections have been assembled to fill this void.

  11. Absolute Time Radiometric Dating: the source

    E-print Network

    Kammer, Thomas

    Absolute Time Radiometric Dating: the source of the dates on the Geologic Time Scale #12;Radiometric Dating · Actually a simple technique. · Only two measurements are needed: · 1. The parent of parent and daughter elements. #12;Basis of the Technique · Radioactive elements "decay." Decay occurs

  12. General Relativity Requires Absolute Space and Time

    E-print Network

    Rainer W. Kuhne

    2002-09-30

    We examine two far-reaching and somewhat heretic consequences of General Relativity. (i) It requires a cosmology which includes a preferred rest frame, absolute space and time. (ii) A rotating universe and time travel are strict solutions of General Relativity.

  13. Teaching Absolute Value Inequalities to Mature Students

    ERIC Educational Resources Information Center

    Sierpinska, Anna; Bobos, Georgeana; Pruncut, Andreea

    2011-01-01

    This paper gives an account of a teaching experiment on absolute value inequalities, whose aim was to identify characteristics of an approach that would realize the potential of the topic to develop theoretical thinking in students enrolled in prerequisite mathematics courses at a large, urban North American university. The potential is…

  14. Absolute Differential Positronium-Formation Cross Sections

    NASA Astrophysics Data System (ADS)

    Shipman, M.; Armitage, S.; Beale, J.; Brawley, S. J.; Fayer, S. E.; Garner, A. J.; Leslie, D. E.; Van Reeth, P.; Laricchia, G.

    2015-07-01

    The first absolute experimental determinations of the differential cross sections for the formation of ground-state positronium are presented for He, Ar, H2 , and CO2 near 0°. Results are compared with available theories. The ratio of the differential and integrated cross sections for the targets exposes the higher propensity for forward emission of positronium formed from He and H2 .

  15. Negative absolute temperature for motional degrees of freedom.

    PubMed

    Braun, S; Ronzheimer, J P; Schreiber, M; Hodgman, S S; Rom, T; Bloch, I; Schneider, U

    2013-01-01

    Absolute temperature is usually bound to be positive. Under special conditions, however, negative temperatures-in which high-energy states are more occupied than low-energy states-are also possible. Such states have been demonstrated in localized systems with finite, discrete spectra. Here, we prepared a negative temperature state for motional degrees of freedom. By tailoring the Bose-Hubbard Hamiltonian, we created an attractively interacting ensemble of ultracold bosons at negative temperature that is stable against collapse for arbitrary atom numbers. The quasimomentum distribution develops sharp peaks at the upper band edge, revealing thermal equilibrium and bosonic coherence over several lattice sites. Negative temperatures imply negative pressures and open up new parameter regimes for cold atoms, enabling fundamentally new many-body states. PMID:23288533

  16. Absolutely calibrated atomic hydrogen cell for high energy atomic collisions

    NASA Astrophysics Data System (ADS)

    Sant'Anna, M. M.; Melo, W. S.; Santos, A. C. F.; Sigaud, G. M.; Montenegro, E. C.; Meyerhof, W. E.; Shah, M. B.

    1997-10-01

    A gaseous cell to study heavy-ion collisions with atomic hydrogen was made with the aim of investigating charge-exchange collisions in the intermediate-to-high velocity regime. The method of thermal-dissociation in a tungsten-tube furnace was used. The operating characteristics of the partially dissociated hydrogen target, which depend not only on the design of the furnace but also on the collision-chamber geometry and pumping system, are described. The absolute calibration of the target cell was performed using double capture of C 3+ at 1.1 MeV and elastic scattering of the He 0 at 1.0 MeV in the mixture of H and H 2. At temperatures of about 2600 K, a degree of dissociation of 80% was obtained with the tungsten filament lasting typically more than 300 h of operation.

  17. Growth from a hypercooled melt near absolute stability

    NASA Technical Reports Server (NTRS)

    Umantsev, A.; Davis, S. H.

    1992-01-01

    The stability of a solid-liquid interface in a hypercooled melt is studied, taking into account attachment kinetics, surface energy, and surface energy in the heat balance. There is a basic-state solution with the planar interface moving at constant speed. Linear-stability theory gives a long-wave absolute-stability limit. Near this point a string model is introduced in which a thermal-boundary-layer approximation is used and an evolution equation for the interface is obtained. In a limiting case this interface equation reduces to a Kuromoto-Sivashinsky equation. Comparison with experimental and numerical results are discussed, and a conceptual picture of unconstrained growth for all undercoolings is addressed.

  18. Absolute plate motions by boundary velocity minimizations

    NASA Technical Reports Server (NTRS)

    Kaula, W. M.

    1975-01-01

    The main interaction of the earth's interior with the lithosphere is as a material source and sink. An absolute reference frame defined by minimizing the translational motion of tectonic plate boundaries differs by 0.6 cm/year from a frame defined by hot spot traces and by 0.4 cm/year from the frame defined by the most plausible model of drag forces on the plates. The rms absolute translational velocities are about 2 cm/year for ocean-ocean plate boundaries and 1.5 cm/year for ocean-continent plate boundaries. The close agreement between the source and sink and the drag-dependent definitions suggests that the lithosphere, as a stress guide, to some extent controls the locations of its sources and sinks.

  19. Absolute-magnitude distributions of supernovae

    SciTech Connect

    Richardson, Dean; Wright, John; Jenkins III, Robert L.; Maddox, Larry

    2014-05-01

    The absolute-magnitude distributions of seven supernova (SN) types are presented. The data used here were primarily taken from the Asiago Supernova Catalogue, but were supplemented with additional data. We accounted for both foreground and host-galaxy extinction. A bootstrap method is used to correct the samples for Malmquist bias. Separately, we generate volume-limited samples, restricted to events within 100 Mpc. We find that the superluminous events (M{sub B} < –21) make up only about 0.1% of all SNe in the bias-corrected sample. The subluminous events (M{sub B} > –15) make up about 3%. The normal Ia distribution was the brightest with a mean absolute blue magnitude of –19.25. The IIP distribution was the dimmest at –16.75.

  20. Asteroid absolute magnitudes and slope parameters

    NASA Technical Reports Server (NTRS)

    Tedesco, Edward F.

    1991-01-01

    A new listing of absolute magnitudes (H) and slope parameters (G) has been created and published in the Minor Planet Circulars; this same listing will appear in the 1992 Ephemerides of Minor Planets. Unlike previous listings, the values of the current list were derived from fits of data at the V band. All observations were reduced in the same fashion using, where appropriate, a single basis default value of 0.15 for the slope parameter. Distances and phase angles were computed for each observation. The data for 113 asteroids was of sufficiently high quality to permit derivation of their H and G. These improved absolute magnitudes and slope parameters will be used to deduce the most reliable bias-corrected asteroid size-frequency distribution yet made.

  1. From Hubble's NGSL to Absolute Fluxes

    NASA Technical Reports Server (NTRS)

    Heap, Sara R.; Lindler, Don

    2012-01-01

    Hubble's Next Generation Spectral Library (NGSL) consists of R-l000 spectra of 374 stars of assorted temperature, gravity, and metallicity. Each spectrum covers the wavelength range, 0.18-1.00 microns. The library can be viewed and/or downloaded from the website, http://archive.stsci.edu/prepds/stisngsll. Stars in the NGSL are now being used as absolute flux standards at ground-based observatories. However, the uncertainty in the absolute flux is about 2%, which does not meet the requirements of dark-energy surveys. We are therefore developing an observing procedure that should yield fluxes with uncertainties less than 1 % and will take part in an HST proposal to observe up to 15 stars using this new procedure.

  2. Absolute quantification method for protein concentration.

    PubMed

    Li, Mingdong; Tan, Jiaojie; Tarlov, Michael J; Zachariah, Michael R

    2014-12-16

    A fast and accurate assay to determine the absolute concentration of proteins is described based on direct measurement of droplet entrapped oligomer formation in electrospray. Here we demonstrate the approach using electrospray differential mobility analysis (ES-DMA), which can distinguish monomers and dimers from higher order oligomers. A key feature of the method is that it allows determination of the absolute number concentration of proteins eliminating the need for protein-specific calibration. The method was demonstrated by measuring the concentration of a NIST Standard Reference Material 927e (bovine serum albumin), a high-purity immunoglobulin G 1?, and a formulated Rituximab. The method may be applied to any electrospray source, regardless of diagnostic tool (e.g., MS or ion-mobility, etc.), provided the electrospray is operated in a droplet-fission mode. PMID:25412350

  3. Probing absolute spin polarization at the nanoscale.

    PubMed

    Eltschka, Matthias; Jäck, Berthold; Assig, Maximilian; Kondrashov, Oleg V; Skvortsov, Mikhail A; Etzkorn, Markus; Ast, Christian R; Kern, Klaus

    2014-12-10

    Probing absolute values of spin polarization at the nanoscale offers insight into the fundamental mechanisms of spin-dependent transport. Employing the Zeeman splitting in superconducting tips (Meservey-Tedrow-Fulde effect), we introduce a novel spin-polarized scanning tunneling microscopy that combines the probing capability of the absolute values of spin polarization with precise control at the atomic scale. We utilize our novel approach to measure the locally resolved spin polarization of magnetic Co nanoislands on Cu(111). We find that the spin polarization is enhanced by 65% when increasing the width of the tunnel barrier by only 2.3 Å due to the different decay of the electron orbitals into vacuum. PMID:25423049

  4. An absolute measure for a key currency

    NASA Astrophysics Data System (ADS)

    Oya, Shunsuke; Aihara, Kazuyuki; Hirata, Yoshito

    It is generally considered that the US dollar and the euro are the key currencies in the world and in Europe, respectively. However, there is no absolute general measure for a key currency. Here, we investigate the 24-hour periodicity of foreign exchange markets using a recurrence plot, and define an absolute measure for a key currency based on the strength of the periodicity. Moreover, we analyze the time evolution of this measure. The results show that the credibility of the US dollar has not decreased significantly since the Lehman shock, when the Lehman Brothers bankrupted and influenced the economic markets, and has increased even relatively better than that of the euro and that of the Japanese yen.

  5. Absolute and relative dosimetry for ELIMED

    SciTech Connect

    Cirrone, G. A. P.; Schillaci, F.; Scuderi, V.; Cuttone, G.; Candiano, G.; Musumarra, A.; Pisciotta, P.; Romano, F.; Carpinelli, M.; Presti, D. Lo; Raffaele, L.; Tramontana, A.; Cirio, R.; Sacchi, R.; Monaco, V.; Marchetto, F.; Giordanengo, S.

    2013-07-26

    The definition of detectors, methods and procedures for the absolute and relative dosimetry of laser-driven proton beams is a crucial step toward the clinical use of this new kind of beams. Hence, one of the ELIMED task, will be the definition of procedures aiming to obtain an absolute dose measure at the end of the transport beamline with an accuracy as close as possible to the one required for clinical applications (i.e. of the order of 5% or less). Relative dosimetry procedures must be established, as well: they are necessary in order to determine and verify the beam dose distributions and to monitor the beam fluence and the energetic spectra during irradiations. Radiochromic films, CR39, Faraday Cup, Secondary Emission Monitor (SEM) and transmission ionization chamber will be considered, designed and studied in order to perform a fully dosimetric characterization of the ELIMED proton beam.

  6. Effect of a single 30?min UMTS mobile phone-like exposure on the thermal pain threshold of young healthy volunteers.

    PubMed

    Vecsei, Zsuzsanna; Csathó, Árpád; Thuróczy, György; Hernádi, István

    2013-10-01

    One of the most frequently investigated effects of radiofrequency electromagnetic fields (RF EMFs) on the behavior of complex biological systems is pain sensitivity. Despite the growing body of evidence of EMF-induced changes in pain sensation, there is no currently accepted experimental protocol for such provocation studies for the healthy human population. In the present study, therefore, we tested the effects of third generation Universal Mobile Telecommunications System (UMTS) RF EMF exposure on the thermal pain threshold (TPT) measured on the surface of the fingers of 20 young adult volunteers. The protocol was initially validated with a topical capsaicin treatment. The exposure time was 30?min and the genuine (or sham) signal was applied to the head through a patch antenna, where RF EMF specific absorption rate (SAR) values were controlled and kept constant at a level of 1.75?W/kg. Data were obtained using randomized, placebo-controlled trials in a double-blind manner. Subjective pain ratings were tested blockwise on a visual analogue rating scale (VAS). Compared to the control and sham conditions, the results provide evidence for intact TPT but a reduced desensitization effect between repeated stimulations within the individual blocks of trials, observable only on the contralateral side for the genuine UMTS exposure. Subjective pain perception (VAS) data indicated marginally decreased overall pain ratings in the genuine exposure condition only. The present results provide pioneering information about human pain sensation in relation to RF EMF exposure and thus may contribute to cover the existing gap between safety research and applied biomedical science targeting the potential biological effects of environmental RF EMFs. PMID:23787775

  7. Relative errors can cue absolute visuomotor mappings.

    PubMed

    van Dam, Loes C J; Ernst, Marc O

    2015-12-01

    When repeatedly switching between two visuomotor mappings, e.g. in a reaching or pointing task, adaptation tends to speed up over time. That is, when the error in the feedback corresponds to a mapping switch, fast adaptation occurs. Yet, what is learned, the relative error or the absolute mappings? When switching between mappings, errors with a size corresponding to the relative difference between the mappings will occur more often than other large errors. Thus, we could learn to correct more for errors with this familiar size (Error Learning). On the other hand, it has been shown that the human visuomotor system can store several absolute visuomotor mappings (Mapping Learning) and can use associated contextual cues to retrieve them. Thus, when contextual information is present, no error feedback is needed to switch between mappings. Using a rapid pointing task, we investigated how these two types of learning may each contribute when repeatedly switching between mappings in the absence of task-irrelevant contextual cues. After training, we examined how participants changed their behaviour when a single error probe indicated either the often-experienced error (Error Learning) or one of the previously experienced absolute mappings (Mapping Learning). Results were consistent with Mapping Learning despite the relative nature of the error information in the feedback. This shows that errors in the feedback can have a double role in visuomotor behaviour: they drive the general adaptation process by making corrections possible on subsequent movements, as well as serve as contextual cues that can signal a learned absolute mapping. PMID:26280315

  8. The absolute spectrophotometric catalog by Anita Cochran

    NASA Astrophysics Data System (ADS)

    Burnashev, V. I.; Burnasheva, B. A.; Ruban, E. V.; Hagen-Torn, E. I.

    2014-06-01

    The absolute spectrophotometric catalog by Anita Cochran is presented in a machine-readable form. The catalog systematizes observations acquired at the McDonald Observatory in 1977-1978. The data are compared with other sources, in particular, the calculated broadband stellar magnitudes are compared with photometric observations by other authors, to show that the observational data given in the catalog are reliable and suitable for a variety of applications. Observations of variable stars of different types make Cochran's catalog especially valuable.

  9. Absolute photoionization cross sections of atomic oxygen

    NASA Technical Reports Server (NTRS)

    Samson, J. A. R.; Pareek, P. N.

    1982-01-01

    The absolute values of photoionization cross sections of atomic oxygen were measured from the ionization threshold to 120 A. An auto-ionizing resonance belonging to the 2S2P4(4P)3P(3Do, 3So) transition was observed at 479.43 A and another line at 389.97 A. The experimental data is in excellent agreement with rigorous close-coupling calculations that include electron correlations in both the initial and final states.

  10. Absolute Differential Positronium-Formation Cross Sections.

    PubMed

    Shipman, M; Armitage, S; Beale, J; Brawley, S J; Fayer, S E; Garner, A J; Leslie, D E; Van Reeth, P; Laricchia, G

    2015-07-17

    The first absolute experimental determinations of the differential cross sections for the formation of ground-state positronium are presented for He, Ar, H2, and CO2 near 0°. Results are compared with available theories. The ratio of the differential and integrated cross sections for the targets exposes the higher propensity for forward emission of positronium formed from He and H2. PMID:26230792

  11. Absolute dosimetry for extreme-ultraviolet lithography

    NASA Astrophysics Data System (ADS)

    Berger, Kurt W.; Campiotti, Richard H.

    2000-06-01

    The accurate measurement of an exposure dose reaching the wafer on an extreme ultraviolet (EUV) lithographic system has been a technical challenge directly applicable to the evaluation of candidate EUV resist materials and calculating lithography system throughputs. We have developed a dose monitoring sensor system that can directly measure EUV intensities at the wafer plane of a prototype EUV lithographic system. This sensor system, located on the wafer stage adjacent to the electrostatic chuck used to grip wafers, operates by translating the sensor into the aerial image, typically illuminating an 'open' (unpatterned) area on the reticle. The absolute signal strength can be related to energy density at the wafer, and thus used to determine resist sensitivity, and the signal as a function of position can be used to determine illumination uniformity at the wafer plane. Spectral filtering to enhance the detection of 13.4 nm radiation was incorporated into the sensor. Other critical design parameters include the packaging and amplification technologies required to place this device into the space and vacuum constraints of a EUV lithography environment. We describe two approaches used to determine the absolute calibration of this sensor. The first conventional approach requires separate characterization of each element of the sensor. A second novel approach uses x-ray emission from a mildly radioactive iron source to calibrate the absolute response of the entire sensor system (detector and electronics) in a single measurement.

  12. Absoluteness of Velocity Produced by Accelerating Process and Absolute Space-time Theory with Variable Scales

    E-print Network

    Mei Xiaochun

    2006-03-03

    It is proved by means of the dynamical effects of special relativity that velocity caused by accelerating process is not a relative concept. The influence of accelerating process should be considered in space-time theory. Besides the Newtonian absolute space-time theory with invariable space-time scales and the Einstein relative space-time theory with variable space-time scales, there exists the third space-time theory, i.e., the absolute space-time theory with variable space-time scales. At present, special relativity is divided into two parts, kinematics and dynamics. In kinematics, force and acceleration are not considered so that space and time becomes relative concepts. This division is completely artificial and irrational. The rational space-time theory should be established on the foundation of dynamics consistently. The changing rules of space, time and mass with speed should be dependent of accelerating processes and with absolute significance. The real meaning of invariability principle of high speed should be that we can not make the speed of an object speed with rest mass reach and exceed the speed of light in vacuum by the method of accelerating object. It is proved that the absolutely resting reference frame exists. In order to eliminate multifarious space-time paradoxes in special relativity, and coincide with Big-bang cosmology, the absolutely resting frame is necessary. A method is put forward to look for the absolutely resting reference frame. The isotropy reference frame of cosmic microwave background radiation can be regarded as the absolutely resting reference frame actually at present.

  13. Balloon-borne infrared telescope for absolute surface photometry of the night sky.

    PubMed

    Hofmann, W; Lemke, D; Thum, C

    1977-12-01

    A dry ice cooled 15-cm ir telescope was used on board the balloon-borne gondola THISBE for absolute surface photometry of the Milky Way, the zodiacal light, and the airglow in the PbS wavelength region. The mechanical, optical, electronical, and thermal design of the instrument is described. The efficiency of the baffle system for suppression of stray light from earth and balloon is discussed in detail. Recent airglow measurements are presented. PMID:20174314

  14. Study of Belousov—Zhabotinsky oscillators in water—acetonitrile medium employing EMF and EPR techniques with o-vanillin, p-vanillin and adrenaline as substrates

    NASA Astrophysics Data System (ADS)

    Lalitha, P. V.; Ramaswamy, R.; Ramakrishnan, Geetha; Rao, P. Sambasiva

    1994-12-01

    The oscillatory behaviour of three substrates, ortho-vanillin, para-vanillin and adrenaline, in mixed media (water plus 20% acetonitrile) has been investigated using EPR and EMF techniques. All these substrates exhibit two types of oscillation involving Br 2/Br - and Mn(III)/Mn(II) redox couples. From the oscillatory characteristics (total time, number of oscillations and time per oscillation) obtained by employing these techniques, the reactivities of the vanillins have been correlated. The Field—Koros—Noyes mechanism, suggested for catalysed systems in pure aqueous medium, is established to be applicable even in mixed media.

  15. Ge/Si(001) heterostructures with dense arrays of Ge quantum dots: morphology, defects, photo-emf spectra and terahertz conductivity

    PubMed Central

    2012-01-01

    Issues of Ge hut cluster array formation and growth at low temperatures on the Ge/Si(001) wetting layer are discussed on the basis of explorations performed by high resolution STM and in-situ RHEED. Dynamics of the RHEED patterns in the process of Ge hut array formation is investigated at low and high temperatures of Ge deposition. Different dynamics of RHEED patterns during the deposition of Ge atoms in different growth modes is observed, which reflects the difference in adatom mobility and their ‘condensation’ fluxes from Ge 2D gas on the surface for different modes, which in turn control the nucleation rates and densities of Ge clusters. Data of HRTEM studies of multilayer Ge/Si heterostructures are presented with the focus on low-temperature formation of perfect films. Heteroepitaxial Si p–i–n-diodes with multilayer stacks of Ge/Si(001) quantum dot dense arrays built in intrinsic domains have been investigated and found to exhibit the photo-emf in a wide spectral range from 0.8 to 5 ?m. An effect of wide-band irradiation by infrared light on the photo-emf spectra has been observed. Photo-emf in different spectral ranges has been found to be differently affected by the wide-band irradiation. A significant increase in photo-emf is observed in the fundamental absorption range under the wide-band irradiation. The observed phenomena are explained in terms of positive and neutral charge states of the quantum dot layers and the Coulomb potential of the quantum dot ensemble. A new design of quantum dot infrared photodetectors is proposed. By using a coherent source spectrometer, first measurements of terahertz dynamical conductivity (absorptivity) spectra of Ge/Si(001) heterostructures were performed at frequencies ranged from 0.3 to 1.2 THz in the temperature interval from 300 to 5 K. The effective dynamical conductivity of the heterostructures with Ge quantum dots has been discovered to be significantly higher than that of the structure with the same amount of bulk germanium (not organized in an array of quantum dots). The excess conductivity is not observed in the structures with the Ge coverage less than 8 Å. When a Ge/Si(001) sample is cooled down the conductivity of the heterostructure decreases. PMID:22824144

  16. A wireless batch sealed absolute capacitive pressure sensor Orhan Akarb

    E-print Network

    Akin, Tayfun

    A wireless batch sealed absolute capacitive pressure sensor Orhan Akarb , Tayfun Akina,b,* , Khalil sensor; Sealed pressure sensor; Capacitive pressure sensor 1. Introduction Absolute pressure sensors- ricate absolute pressure sensors with sealed cavities that also allow easy lead transfer from inside

  17. Absolute versus convective instability of spiral waves Bjorn Sandstede

    E-print Network

    Scheel, Arnd

    Absolute versus convective instability of spiral waves Bjo¨rn Sandstede Department of Mathematics and convective instabilities of spirals are investigated using the continuous and the so-called absolute spectrum I, Freie Universita¨t Berlin, Arnimallee 2-6, 14195 Berlin, Germany Received 26 May 2000 Absolute

  18. Using, Seeing, Feeling, and Doing Absolute Value for Deeper Understanding

    ERIC Educational Resources Information Center

    Ponce, Gregorio A.

    2008-01-01

    Using sticky notes and number lines, a hands-on activity is shared that anchors initial student thinking about absolute value. The initial point of reference should help students successfully evaluate numeric problems involving absolute value. They should also be able to solve absolute value equations and inequalities that are typically found in…

  19. A Conceptual Approach to Absolute Value Equations and Inequalities

    ERIC Educational Resources Information Center

    Ellis, Mark W.; Bryson, Janet L.

    2011-01-01

    The absolute value learning objective in high school mathematics requires students to solve far more complex absolute value equations and inequalities. When absolute value problems become more complex, students often do not have sufficient conceptual understanding to make any sense of what is happening mathematically. The authors suggest that the…

  20. SYSTEM PERFORMANCE OF ABSOLUTE QUARTZ-CRYSTAL BAROMETERS WITH

    E-print Network

    Muschinski, Andreas

    SYSTEM PERFORMANCE OF ABSOLUTE QUARTZ-CRYSTAL BAROMETERS WITH SUB-MICROBAR PRECISION A Thesis 2009 All Rights Reserved #12;SYSTEM PERFORMANCE OF ABSOLUTE QUARTZ-CRYSTAL BAROMETERS WITH SUB OF ABSOLUTE QUARTZ-CRYSTAL BAROMETERS WITH SUB-MICROBAR PRECISION SEPTEMBER 2009 GANESH KUMAR SUBRAMANIAN

  1. Targeted CT Screening for Lung Cancer using Absolute Risk Prediction

    E-print Network

    Brent, Roger

    Targeted CT Screening for Lung Cancer using Absolute Risk Prediction Stephanie A. Kovalchik skovalch@rand.org FHCRC 2014 Risk Prediction Symposium June 11, 2014 1 #12;Outline · Lung Cancer Epidemiology and Screening · Screening Benefit and Absolute Risk · Absolute Risk Model for Lung Cancer

  2. Absolute Gravity and Crustal Deformation in Yellowstone Caldera

    NASA Astrophysics Data System (ADS)

    McAdoo, D. C.; Tikku, A. A.; Klopping, F.; Winester, D.; Stone, W.; Schenewerk, M.

    2001-12-01

    The Yellowstone Caldera is an active volcanic area at the end of the Snake River Plateau-Yellowstone hotspot chain and has been the focus of a number of geodetic surveys designed to measure crustal motion and mass flux. Major episodes of volcanic activity in the Yellowstone Caldera were 2.0, 1.2, and 0.6 Ma ago. The caldera is still active today as evidenced by seismicity, high heat flow and the presence of numerous thermal hot springs and geysers, in addition to measurable uplift and subsidence of the caldera on the order of 10-20 cm. In September 2000 we collected the first absolute gravity measurements in Yellowstone, with coincident GPS measurements. Our 12 baseline observations (8 with the portable A-10 and four with the FG-5) were distributed throughout the caldera. One of our objectives was to establish benchmarks on bedrock to minimize water table level fluctuations; six of our sites meet this criteria. Four of the sites coincide with relative gravity stations established by the University of Utah. These relative gravity stations can now be tied to absolute gravity stations. Assessing the relative contribution of magmatic and hydrothermal processes must await repeat surveying. FG-5 data collected close by Old Faithful in 2000 show a 15 microgal signal over the course of a day. This signal appears to be similar in amplitude, but differs in periodicity, to the signal obtained at other geysers \\{e.g., at Wakarewarewa Geyser flat in New Zealand\\}. We will present results of a repeat FG-5 (and GPS) survey at Old Faithful in 2001.

  3. Protect children from EMF.

    PubMed

    Markov, M; Grigoriev, Y

    2015-09-01

    The twenty-first century is marked with aggressive development of the wireless communications (satellite, mobile phones, Internet, Wi-Fi). In addition to thousand of satellites that deliver radio and TV signals, large satellite and base station networks secure intensive instant delivery of audio and video information. It is fair to say that that the entire civilization, both biosphere and mankind are exposed to continuous exposure of multitude of radiofrequency (RF) signals. It should be taken into account that the entire world population is exposed to exponentially increasing RF radiation from base stations and satellite antennas. While several years ago the potential hazard was connected with placement of mobile phones close to human head, today "smart phones" represent small, but powerful computers continuously receiving audio and video data. The largest group of users is the children and teenagers who "need" to communicate nearly 24?h a day. This is even more important because cell phones and tablets may be seen in the hands of children as little as two years in age. There is no way to assess and predict the potential damages of children brain, vision and hearing under exposure to RF radiation. The WHO precautionary principle and IARC classification must be applied in discussing the potential hazard of the use of today's and tomorrow's communication devices. PMID:26444201

  4. Clock time is absolute and universal

    NASA Astrophysics Data System (ADS)

    Shen, Xinhang

    2015-09-01

    A critical error is found in the Special Theory of Relativity (STR): mixing up the concepts of the STR abstract time of a reference frame and the displayed time of a physical clock, which leads to use the properties of the abstract time to predict time dilation on physical clocks and all other physical processes. Actually, a clock can never directly measure the abstract time, but can only record the result of a physical process during a period of the abstract time such as the number of cycles of oscillation which is the multiplication of the abstract time and the frequency of oscillation. After Lorentz Transformation, the abstract time of a reference frame expands by a factor gamma, but the frequency of a clock decreases by the same factor gamma, and the resulting multiplication i.e. the displayed time of a moving clock remains unchanged. That is, the displayed time of any physical clock is an invariant of Lorentz Transformation. The Lorentz invariance of the displayed times of clocks can further prove within the framework of STR our earth based standard physical time is absolute, universal and independent of inertial reference frames as confirmed by both the physical fact of the universal synchronization of clocks on the GPS satellites and clocks on the earth, and the theoretical existence of the absolute and universal Galilean time in STR which has proved that time dilation and space contraction are pure illusions of STR. The existence of the absolute and universal time in STR has directly denied that the reference frame dependent abstract time of STR is the physical time, and therefore, STR is wrong and all its predictions can never happen in the physical world.

  5. Absolute Radiometric Calibration of EUNIS-06

    NASA Technical Reports Server (NTRS)

    Thomas, R. J.; Rabin, D. M.; Kent, B. J.; Paustian, W.

    2007-01-01

    The Extreme-Ultraviolet Normal-Incidence Spectrometer (EUNIS) is a soundingrocket payload that obtains imaged high-resolution spectra of individual solar features, providing information about the Sun's corona and upper transition region. Shortly after its successful initial flight last year, a complete end-to-end calibration was carried out to determine the instrument's absolute radiometric response over its Longwave bandpass of 300 - 370A. The measurements were done at the Rutherford-Appleton Laboratory (RAL) in England, using the same vacuum facility and EUV radiation source used in the pre-flight calibrations of both SOHO/CDS and Hinode/EIS, as well as in three post-flight calibrations of our SERTS sounding rocket payload, the precursor to EUNIS. The unique radiation source provided by the Physikalisch-Technische Bundesanstalt (PTB) had been calibrated to an absolute accuracy of 7% (l-sigma) at 12 wavelengths covering our bandpass directly against the Berlin electron storage ring BESSY, which is itself a primary radiometric source standard. Scans of the EUNIS aperture were made to determine the instrument's absolute spectral sensitivity to +- 25%, considering all sources of error, and demonstrate that EUNIS-06 was the most sensitive solar E W spectrometer yet flown. The results will be matched against prior calibrations which relied on combining measurements of individual optical components, and on comparisons with theoretically predicted 'insensitive' line ratios. Coordinated observations were made during the EUNIS-06 flight by SOHO/CDS and EIT that will allow re-calibrations of those instruments as well. In addition, future EUNIS flights will provide similar calibration updates for TRACE, Hinode/EIS, and STEREO/SECCHI/EUVI.

  6. An absolute radius scale for Saturn's rings

    NASA Technical Reports Server (NTRS)

    Nicholson, Philip D.; Cooke, Maren L.; Pelton, Emily

    1990-01-01

    Radio and stellar occultation observations of Saturn's rings made by the Voyager spacecraft are discussed. The data reveal systematic discrepancies of almost 10 km in some parts of the rings, limiting some of the investigations. A revised solution for Saturn's rotation pole has been proposed which removes the discrepancies between the stellar and radio occultation profiles. Corrections to previously published radii vary from -2 to -10 km for the radio occultation, and +5 to -6 km for the stellar occultation. An examination of spiral density waves in the outer A Ring supports that the revised absolute radii are in error by no more than 2 km.

  7. Absolute method of measuring magnetic susceptibility

    USGS Publications Warehouse

    Thorpe, A.; Senftle, F.E.

    1959-01-01

    An absolute method of standardization and measurement of the magnetic susceptibility of small samples is presented which can be applied to most techniques based on the Faraday method. The fact that the susceptibility is a function of the area under the curve of sample displacement versus distance of the magnet from the sample, offers a simple method of measuring the susceptibility without recourse to a standard sample. Typical results on a few substances are compared with reported values, and an error of less than 2% can be achieved. ?? 1959 The American Institute of Physics.

  8. Residential Thermal Mass Construction 

    E-print Network

    Thieken, J. S.

    1988-01-01

    -hour period. The interior of a building with mass, on the other hand, would not rise as high or fall as low. Also, the high and low peak temperatures would be greatly delayed. The reason for this moderating effect is that the mass absorbs... the heat and delays its transfer. In more technical terms, the thermal mass effect (TME) is the reduction in a building's heating and cooling energy caused by absolute reductions and shifting of dynamic heat fluxes through a massive envelope...

  9. A versatile thermoelectric temperature controller with 10 mK reproducibility and 100 mK absolute accuracy

    E-print Network

    Libbrecht, Kenneth G.

    of Physics. doi:10.1063/1.3274204 Thermal management is an important aspect of many scientific experiments temperature stability in the system being controlled. In our own experi- ments investigating the molecular, absolute accuracy, and a well-behaved tran- sient response. To meet our requirements, we have developed

  10. Absolute Cavity Pyrgeometer to Measure the Absolute Outdoor Longwave Irradiance with Traceability to International System of Units, SI

    SciTech Connect

    Reda, I.; Zeng, J.; Scheuch, J.; Hanssen, L.; Wilthan, B.; Myers, D.; Stoffel, T.

    2012-03-01

    This article describes a method of measuring the absolute outdoor longwave irradiance using an absolute cavity pyrgeometer (ACP), U.S. Patent application no. 13/049, 275. The ACP consists of domeless thermopile pyrgeometer, gold-plated concentrator, temperature controller, and data acquisition. The dome was removed from the pyrgeometer to remove errors associated with dome transmittance and the dome correction factor. To avoid thermal convection and wind effect errors resulting from using a domeless thermopile, the gold-plated concentrator was placed above the thermopile. The concentrator is a dual compound parabolic concentrator (CPC) with 180{sup o} view angle to measure the outdoor incoming longwave irradiance from the atmosphere. The incoming irradiance is reflected from the specular gold surface of the CPC and concentrated on the 11 mm diameter of the pyrgeometer's blackened thermopile. The CPC's interior surface design and the resulting cavitation result in a throughput value that was characterized by the National Institute of Standards and Technology. The ACP was installed horizontally outdoor on an aluminum plate connected to the temperature controller to control the pyrgeometer's case temperature. The responsivity of the pyrgeometer's thermopile detector was determined by lowering the case temperature and calculating the rate of change of the thermopile output voltage versus the changing net irradiance. The responsivity is then used to calculate the absolute atmospheric longwave irradiance with an uncertainty estimate (U{sub 95}) of {+-}3.96 W m{sup 02} with traceability to the International System of Units, SI. The measured irradiance was compared with the irradiance measured by two pyrgeometers calibrated by the World Radiation Center with traceability to the Interim World Infrared Standard Group, WISG. A total of 408 readings were collected over three different nights. The calculated irradiance measured by the ACP was 1.5 W/m{sup 2} lower than that measured by the two pyrgeometers that are traceable to WISG, with a standard deviation of {+-}0.7 W m{sup -2}. These results suggest that the ACP design might be used for addressing the need to improve the international reference for broadband outdoor longwave irradiance measurements.

  11. Swarm's Absolute Scalar Magnetometers Burst Mode Results

    NASA Astrophysics Data System (ADS)

    Coisson, P.; Vigneron, P.; Hulot, G.; Crespo Grau, R.; Brocco, L.; Lalanne, X.; Sirol, O.; Leger, J. M.; Jager, T.; Bertrand, F.; Boness, A.; Fratter, I.

    2014-12-01

    Each of the three Swarm satellites embarks an Absolute Scalar Magnetometer (ASM) to provide absolute scalar measurements of the magnetic field with high accuracy and stability. Nominal data acquisition of these ASMs is 1 Hz. But they can also run in a so-called "burst mode" and provide data at 250 Hz. During the commissioning phase of the mission, seven burst mode acquisition campaigns have been run simultaneously for all satellites, obtaining a total of ten days of burs-mode data. These campaigns allowed the identification of issues related to the operations of the piezo-electric motor and the heaters connected to the ASM, that do not impact the nominal 1 Hz scalar data. We analyze the burst mode data to identify high frequency geomagnetic signals, focusing the analysis in two regions: the low latitudes, where we seek signatures of ionospheric irregularities, and the high latitudes, to identify high frequency signals related to polar region currents. Since these campaigns have been conducted during the initial months of the mission, the three satellites where still close to each other, allowing to analyze the spatial coherency of the signals. Wavelet analysis have revealed 31 Hz signals appearing in the night-side in the equatorial region.

  12. Experimental results for absolute cylindrical wavefront testing

    NASA Astrophysics Data System (ADS)

    Reardon, Patrick J.; Alatawi, Ayshah

    2014-09-01

    Applications for Cylindrical and near-cylindrical surfaces are ever-increasing. However, fabrication of high quality cylindrical surfaces is limited by the difficulty of accurate and affordable metrology. Absolute testing of such surfaces represents a challenge to the optical testing community as cylindrical reference wavefronts are difficult to produce. In this paper, preliminary results for a new method of absolute testing of cylindrical wavefronts are presented. The method is based on the merging of the random ball test method with the fiber optic reference test. The random ball test assumes a large number of interferograms of a good quality sphere with errors that are statistically distributed such that the average of the errors goes to zero. The fiber optic reference test utilizes a specially processed optical fiber to provide a clean high quality reference wave from an incident line focus from the cylindrical wave under test. By taking measurements at different rotation and translations of the fiber, an analogous procedure can be employed to determine the quality of the converging cylindrical wavefront with high accuracy. This paper presents and discusses the results of recent tests of this method using a null optic formed by a COTS cylindrical lens and a free-form polished corrector element.

  13. Absolute configuration of 7-epi-sesquithujene.

    PubMed

    Khrimian, Ashot; Cossé, Allard A; Crook, Damon J

    2011-06-24

    7-epi-sesquithujene (1) is a bicyclic sesquiterpene isolated from phoebe oil, an essential oil of the Brazilian walnut tree, Phoebe porosa. It is also produced by stressed ash trees and has been shown to elicit strong electrophysiological responses on emerald ash borer, Agrilus planipennis, antennae. In the course of the development of a synthetic 7-epi-sesquithujene lure for field testing against the emerald ash borer, we found that the absolute configuration of this compound had not been determined. We isolated >95% pure 7-epi-sesquithujene from phoebe oil via successive fractionation and conventional and argentation (HPLC) chromatographies. The specific optical rotation of this compound matched that of a synthetic product of known configuration. We also synthesized two other stereoisomers of sesquithujene and developed a chiral GC method to separate all four. Based on the specific rotation, stereoselective syntheses, and chiral GC analyses, 7-epi-sesquithujene present in phoebe oil and white ash was found to have the 2S,6S,7R absolute configuration. PMID:21574561

  14. Pressure And Thermal Modeling Of Rocket Launches

    NASA Technical Reports Server (NTRS)

    Smith, Sheldon D.; Myruski, Brian L.; Farmer, Richard C.; Freeman, Jon A.

    1995-01-01

    Report presents mathematical model for use in designing rocket-launching stand. Predicts pressure and thermal environment, as well as thermal responses of structures to impinging rocket-exhaust plumes. Enables relatively inexperienced analyst to determine time-varying distributions and absolute levels of pressure and heat loads on structures.

  15. Optical cryostat realizations at absolut System

    NASA Astrophysics Data System (ADS)

    Trollier, T.; Ravex, A.; Tanchon, J.

    2014-01-01

    This paper describes two kinds of optical cryostats designed and manufactured at Absolut System. The first one makes use of pressurized LN2 for temperature control of a sample holder in the 80 K - 470 K temperature range. An optical window is implemented above the sample holder to allow for rugosity and 3D distortion of heterogeneous semicon sample assemblies on a wafer. The second one makes use of CRYOMECH remote motor type pulse tube cryocoolers for temperature control of the sample holder in the 3 K - 300 K temperature range. In this type of cryostats, particular attention has been paid to reduce the vibrations exported by the cooler. These 4 K ultra low vibration cryostats are used for characterization of samples via optical windows. Both designs will be presented and the performance reported.

  16. Absolute image registration for geosynchronous satellites

    NASA Technical Reports Server (NTRS)

    Nankervis, R.; Koch, D.; Sielski, H.; Hall, D.

    1980-01-01

    A procedure for the absolute registration of earth images acquired by cameras on geosynchronous satellites is described. A conventional least squares process is used to estimate navigational parameters and camera pointing biases from observed minus computed landmark line and element numbers. These estimated parameters along with orbit and attitude dynamic models are used to register images, employing an automated grey-level correlation technique, inside the span represented by the landmark data. Experimental results obtained from processing the SMS-2 observation data base covering May 2, 1979 through May 20, 1979 show registration accuracies with a standard deviation of less than two pixels if the registration is within the landmark data span. It is also found that accurate registration can be expected for images obtained up to 48 hours outside of the landmark data span.

  17. Enhanced functional networks in absolute pitch

    PubMed Central

    Loui, Psyche; Zamm, Anna; Schlaug, Gottfried

    2013-01-01

    Functional networks in the human brain give rise to complex cognitive and perceptual abilities. While the decrease of functional connectivity is linked to neurological and psychiatric disorders, less is known about the consequences of increased functional connectivity. One population that has exceptionally enhanced perceptual abilities is people with absolute pitch (AP) — an ability to categorize tones into pitch classes without reference. AP has been linked to exceptional talent as well as to psychiatric and neurological conditions. Here we show that AP possessors have increased functional activation during music listening, as well as increased degrees, clustering, and local efficiency of functional correlations, with the difference being highest around the left superior temporal gyrus. Our results provide the first evidence that increased functional connectivity in a small-world brain network is related to exceptional perceptual abilities in a healthy population. PMID:22836173

  18. Towards absolute calibration of optical tweezers

    E-print Network

    Viana, N B; Mazolli, A; Mesquita, O N; Nussenzveig, H M; Rocha, M S

    2006-01-01

    Aiming at absolute force calibration of optical tweezers, following a critical review of proposed theoretical models, we present and test the results of MDSA (Mie-Debye-Spherical Aberration) theory, an extension of a previous (MD) model, taking account of spherical aberration at the glass/water interface. This first-principles theory is formulated entirely in terms of experimentally accessible parameters (none adjustable). Careful experimental tests of the MDSA theory, undertaken at two laboratories, with very different setups, are described. A detailed description is given of the procedures employed to measure laser beam waist, local beam power at the transparent microspheres trapped by the tweezers, microsphere radius and the trap transverse stiffness, as a function of radius and height in the (inverted microscope) sample chamber. We find generally very good agreement with MDSA theory predictions, for a wide size range, from the Rayleigh domain to large radii, including the values most often employed in pra...

  19. On the Traces of Absolute Enantioselective Synthesis

    NASA Astrophysics Data System (ADS)

    Barabás, Béla; Caglioti, Luciano; Faglioni, Francesco; Florini, Nicola; Lazzeretti, Paolo; Maioli, Marco; Micskei, Károly; Rábai, Gyula; Taddei, Ferdinando; Zucchi, Claudia; Pályi, Gyula

    2007-12-01

    The main goal of this communication is to show the utility of empirical approaches combined with mathematical methods in the research regarding the molecular basis of biological chirality. Preparative results (enantiomeric excesses, e.e.) obtained in asymmetric autocatalysis with (AAC) and without (AES) chiral additive were analyzed. Statistical calculations show, that AES (absolute enantioselective synthesis) experiments yield two independent groups of results with prevalence of the R- or S-enantiomer. These are distributed asymmetrically in a second-order beta distribution. Empirical calculations both on AAC and EAS enable to identify the very low (statistical) e.e.-s amplified by AES. These initial e.e.-s show normal distribution. Possible molecular-level reasons of these results were controlled by quantum chemical MO calculations and compatible mechanism(s) are discussed.

  20. Micron Accurate Absolute Ranging System: Range Extension

    NASA Technical Reports Server (NTRS)

    Smalley, Larry L.; Smith, Kely L.

    1999-01-01

    The purpose of this research is to investigate Fresnel diffraction as a means of obtaining absolute distance measurements with micron or greater accuracy. It is believed that such a system would prove useful to the Next Generation Space Telescope (NGST) as a non-intrusive, non-contact measuring system for use with secondary concentrator station-keeping systems. The present research attempts to validate past experiments and develop ways to apply the phenomena of Fresnel diffraction to micron accurate measurement. This report discusses past research on the phenomena, and the basis of the use Fresnel diffraction distance metrology. The apparatus used in the recent investigations, experimental procedures used, preliminary results are discussed in detail. Continued research and equipment requirements on the extension of the effective range of the Fresnel diffraction systems is also described.

  1. MAGSAT: Vector magnetometer absolute sensor alignment determination

    NASA Technical Reports Server (NTRS)

    Acuna, M. H.

    1981-01-01

    A procedure is described for accurately determining the absolute alignment of the magnetic axes of a triaxial magnetometer sensor with respect to an external, fixed, reference coordinate system. The method does not require that the magnetic field vector orientation, as generated by a triaxial calibration coil system, be known to better than a few degrees from its true position, and minimizes the number of positions through which a sensor assembly must be rotated to obtain a solution. Computer simulations show that accuracies of better than 0.4 seconds of arc can be achieved under typical test conditions associated with existing magnetic test facilities. The basic approach is similar in nature to that presented by McPherron and Snare (1978) except that only three sensor positions are required and the system of equations to be solved is considerably simplified. Applications of the method to the case of the MAGSAT Vector Magnetometer are presented and the problems encountered discussed.

  2. Absolute measurements of fast neutrons using yttrium

    SciTech Connect

    Roshan, M. V.; Springham, S. V.; Rawat, R. S.; Lee, P.; Krishnan, M.

    2010-08-15

    Yttrium is presented as an absolute neutron detector for pulsed neutron sources. It has high sensitivity for detecting fast neutrons. Yttrium has the property of generating a monoenergetic secondary radiation in the form of a 909 keV gamma-ray caused by inelastic neutron interaction. It was calibrated numerically using MCNPX and does not need periodic recalibration. The total yttrium efficiency for detecting 2.45 MeV neutrons was determined to be f{sub n}{approx}4.1x10{sup -4} with an uncertainty of about 0.27%. The yttrium detector was employed in the NX2 plasma focus experiments and showed the neutron yield of the order of 10{sup 8} neutrons per discharge.

  3. Absolute nonlocality via distributed computing without communication

    NASA Astrophysics Data System (ADS)

    Czekaj, ?.; Paw?owski, M.; Vértesi, T.; Grudka, A.; Horodecki, M.; Horodecki, R.

    2015-09-01

    Understanding the role that quantum entanglement plays as a resource in various information processing tasks is one of the crucial goals of quantum information theory. Here we propose an alternative perspective for studying quantum entanglement: distributed computation of functions without communication between nodes. To formalize this approach, we propose identity games. Surprisingly, despite no signaling, we obtain that nonlocal quantum strategies beat classical ones in terms of winning probability for identity games originating from certain bipartite and multipartite functions. Moreover we show that, for a majority of functions, access to general nonsignaling resources boosts success probability two times in comparison to classical ones for a number of large enough outputs. Because there are no constraints on the inputs and no processing of the outputs in the identity games, they detect very strong types of correlations: absolute nonlocality.

  4. Relativistic Spacetime Based on Absolute Background

    E-print Network

    ChiYi Chen

    2015-09-19

    Based on the consideration of naturalness and physical facts in Einstein's theories of relativity, a nontrivial spacetime physical picture, which has a slight difference from the standard one, is introduced by making a further distinction on the absolute background of spacetime and the relative length or duration of base units of spacetime. In this picture, the coordinate base units in gravity-induced spacetime metric are defined by the standard clock and ruler equipped by the observer, and duplicated onto the every position of the whole universe. In contrast, the proper base units of spacetime in gravitational field are defined by the length and duration of physical events intervals in the same-type standard clock and ruler really located at every position of the universe. In principle, the reading number of the standard clock is counted by the undergone times of unit intervals defined depending on a certain kind of proper events. But the size of the base units of spacetime is essentially depicted by the length of the line segment, which is cut from the absolute background of spacetime by the proper events of unit interval. The effect of gravitation is just to change the length of this segment for base spacetime units. On the basis of such a physical picture of spacetime, in a fairly natural way we re-derive a new classical dynamical equation which satisfies a more realistic and moderately general principle of relativity. To further examine this physical picture including of gravitation and spacetime, we also reinterpret the gravitational redshifts for solar gravity tests.

  5. Measured and modelled absolute gravity in Greenland

    NASA Astrophysics Data System (ADS)

    Nielsen, E.; Forsberg, R.; Strykowski, G.

    2012-12-01

    Present day changes in the ice volume in glaciated areas like Greenland will change the load on the Earth and to this change the lithosphere will respond elastically. The Earth also responds to changes in the ice volume over a millennial time scale. This response is due to the viscous properties of the mantle and is known as Glaical Isostatic Adjustment (GIA). Both signals are present in GPS and absolute gravity (AG) measurements and they will give an uncertainty in mass balance estimates calculated from these data types. It is possible to separate the two signals if both gravity and Global Positioning System (GPS) time series are available. DTU Space acquired an A10 absolute gravimeter in 2008. One purpose of this instrument is to establish AG time series in Greenland and the first measurements were conducted in 2009. Since then are 18 different Greenland GPS Network (GNET) stations visited and six of these are visited more then once. The gravity signal consists of three signals; the elastic signal, the viscous signal and the direct attraction from the ice masses. All of these signals can be modelled using various techniques. The viscous signal is modelled by solving the Sea Level Equation with an appropriate ice history and Earth model. The free code SELEN is used for this. The elastic signal is modelled as a convolution of the elastic Greens function for gravity and a model of present day ice mass changes. The direct attraction is the same as the Newtonian attraction and is calculated as this. Here we will present the preliminary results of the AG measurements in Greenland. We will also present modelled estimates of the direct attraction, the elastic and the viscous signals.

  6. Surface Characterization of pNIPAM Under Varying Absolute Humidity

    NASA Astrophysics Data System (ADS)

    Chhabra, Arnav; Kanapuram, Ravitej; Leva, Harrison; Trejo, Juan; Kim, Tae Jin; Hidrovo, Carlos

    2012-11-01

    Poly(N-isopropylacrylamide) has become ubiquitously known as a ``smart'' polymer, showing many promising applications in tissue engineering and drug delivery systems. These applications are particularly reliant on its trenchant, thermally induced hydrophilic-hydrophobic transition that occurs at the lower critical solution temperature (LCST). This feature imparts the pNIPAM programmable adsorption and release capabilities, thus eliminating the need for additional enzymes when removing cells from pNIPAM coated surfaces and leaving the extracellular matrix proteins of the cells largely untouched. The dependence of the LCST on molecular weight, solvent systems, and various salts has been studied extensively. However, what has not been explored is the effect of humidity on the characteristic properties of the polymer, specifically the LCST and the magnitude of the hydrophilic-hydrophobic transition. We studied the surface energy variation of pNIPAM as a function of humidity by altering the absolute humidity and keeping the ambient temperature constant. Our experiments were conducted inside a cuboidal environmental chamber with control over the temperature and humidity inside the chamber. A controlled needle was employed to dispense size-regulated droplets. Throughout this process, a CCD camera was used to image the droplet and the static contact angle was determined using image processing techniques. The behavior of pNIPAM as a function of humidity is presented and discussed.

  7. Absolute absorption on the potassium D lines: theory and experiment

    NASA Astrophysics Data System (ADS)

    Hanley, Ryan K.; Gregory, Philip D.; Hughes, Ifan G.; Cornish, Simon L.

    2015-10-01

    We present a detailed study of the absolute Doppler-broadened absorption of a probe beam scanned across the potassium D lines in a thermal vapour. Spectra using a weak probe were measured on the 4S \\to 4P transition and compared to the theoretical model of the electric susceptibility detailed by Zentile et al (2015 Comput. Phys. Commun. 189 162-74) in the code named ElecSus. Comparisons were also made on the 4S \\to 5P transition with an adapted version of ElecSus. This is the first experimental test of ElecSus on an atom with a ground state hyperfine splitting smaller than that of the Doppler width. An excellent agreement was found between ElecSus and experimental measurements at a variety of temperatures with rms errors ˜ {10}-3. We have also demonstrated the use of ElecSus as an atomic vapour thermometry tool, and present a possible new measurement technique of transition decay rates which we predict to have a precision of ˜3 {kHz}.

  8. Absolutely Calibrated 2-cm l Radiometry of Titan and Implications

    NASA Astrophysics Data System (ADS)

    Janssen, Michael A.; Lorenz, R. D.; Paganelli, F.; Kirk, R. L.; Lopes, R. M.; Cassini RADAR Team

    2007-10-01

    The Cassini Radar instrument includes a passive microwave radiometer that operates at 13.78 GHz ( 2.2 cm wavelength). The radiometer is used to observe the thermal emission from Titan's surface at resolutions ranging from 5 - 500 km and at a variety of emission angles and polarizations. Nearly the entire surface has been observed through May, 2007, enabling the construction of a mosaiced global map of the surface brightness temperature at normal incidence. The approach to producing this map will be presented. Our knowledge from Radar imaging of the nature of Titan's surface in key regions - specifically, the equatorial dune fields, the northern seas, and the Huygens probe landing site temperature - enables us to absolutely calibrate this map. Implications for surface composition and physical properties are discussed. Among other interpretations, an equator to pole temperature difference will be presented. This work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

  9. On-orbit absolute temperature calibration using multiple phase change materials: overview of recent technology advancements

    NASA Astrophysics Data System (ADS)

    Best, Fred A.; Adler, Douglas P.; Pettersen, Claire; Revercomb, Henry E.; Perepezko, John H.

    2010-11-01

    NASA's anticipated plan for a mission dedicated to Climate (CLARREO) will hinge upon the ability to fly SI traceable standards that provide irrefutable absolute measurement accuracy. As an example, instrumentation designed to measure spectrally resolved infrared radiances will require high-emissivity calibration blackbodies that have absolute temperature uncertainties of better than 0.045K (3 sigma). A novel scheme to provide absolute calibration of temperature sensors onorbit, that uses the transient melt signatures from multiple phase change materials, has been demonstrated in the laboratory at the University of Wisconsin and is now undergoing technology advancement under NASA Instrument Incubator Program funding. Using small quantities of phase change material (less than half of a percent of the mass of the cavity), melt temperature accuracies of better than 10 mK have been demonstrated for mercury, water, and gallium (providing calibration from 233K to 303K). Refinements currently underway focus on ensuring that the melt materials in their sealed confinement housings perform as expected in the thermal and microgravity environment of a multi-year spaceflight mission. Thermal soak and cycling tests are underway to demonstrate that there is no dissolution from the housings into the melt materials that could alter melt temperature, and that there is no liquid metal embrittlement of the housings from the metal melt materials. In addition, NASA funding has been recently secured to conduct a demonstration of this scheme in the microgravity environment of the International Space Station.

  10. Absolute nuclear material assay using count distribution (LAMBDA) space

    DOEpatents

    Prasad, Mano K.; Snyderman, Neal J.; Rowland, Mark S.

    2015-12-01

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  11. Absolute nuclear material assay using count distribution (LAMBDA) space

    DOEpatents

    Prasad, Manoj K. (Pleasanton, CA); Snyderman, Neal J. (Berkeley, CA); Rowland, Mark S. (Alamo, CA)

    2012-06-05

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  12. A Liquid-Helium-Cooled Absolute Reference Cold Load forLong-Wavelength Radiometric Calibration

    SciTech Connect

    Bensadoun, M.; Witebsky, C.; Smoot, George F.; De Amici,Giovanni; Kogut, A.; Levin, S.

    1990-05-01

    We describe a large (78-cm) diameter liquid-helium-cooled black-body absolute reference cold load for the calibration of microwave radiometers. The load provides an absolute calibration near the liquid helium (LHe) boiling point, accurate to better than 30 mK for wavelengths from 2.5 to 25 cm (12-1.2 GHz). The emission (from non-LHe temperature parts of the cold load) and reflection are small and well determined. Total corrections to the LHe boiling point temperature are {le} 50 mK over the operating range. This cold load has been used at several wavelengths at the South Pole and at the White Mountain Research Station. In operation, the average LHe loss rate was {le} 4.4 l/hr. Design considerations, radiometric and thermal performance and operational aspects are discussed. A comparison with other LHe-cooled reference loads including the predecessor of this cold load is given.

  13. Absolute and Convective Instability of a Liquid Jet

    NASA Technical Reports Server (NTRS)

    Lin, S. P.; Hudman, M.; Chen, J. N.

    1999-01-01

    The existence of absolute instability in a liquid jet has been predicted for some time. The disturbance grows in time and propagates both upstream and downstream in an absolutely unstable liquid jet. The image of absolute instability is captured in the NASA 2.2 sec drop tower and reported here. The transition from convective to absolute instability is observed experimentally. The experimental results are compared with the theoretical predictions on the transition Weber number as functions of the Reynolds number. The role of interfacial shear relative to all other relevant forces which cause the onset of jet breakup is explained.

  14. Measurement of the thermodynamic properties of saturated solid solutions of compounds in the Ag-Sn-Se system by the EMF method

    NASA Astrophysics Data System (ADS)

    Moroz, M. V.; Prokhorenko, M. V.

    2015-08-01

    The dependence of the EMF ( E) of galvanic cells Ag|AgI|Ag2GeS3 glass| D on temperature (where Ag, D denotes the electrodes of an electrochemical cell; D represents equilibrium two- and three-phase alloys of the Ag-Sn-Se system; and AgI|Ag2GeS3 glass is a bilayer membrane with purely ionic (Ag+) conductivity) is studied in the range of 480-580 K. Analytical equations of E( T) are used to calculate the values of the thermodynamic functions of saturated solid solutions of the SnSe, ?-Ag2Se, AgSnSe2, and Ag8SnSe6 phases of the Ag-Sn-Se system in the standard state.

  15. Determination of torque speed current characteristics of a brushless DC motor by utilizing back-EMF of non-energized phase

    NASA Astrophysics Data System (ADS)

    Jang, G. H.; Yeom, J. H.; Kim, M. G.

    2007-03-01

    This paper presents a method to determine the torque constant and the torque-speed-current characteristics of a brushless DC (BLDC) motor by utilizing back-EMF variation of nonenergized phase. It also develops a BLDC motor controller with a digital signal processor (DSP) to monitor its current, voltage and speed in real time. Torque-speed-current characteristics of a BLDC motor are determined by using the proposed method and the developed controller. They are compared with the torque-speed-current characteristics measured by dynamometer experimentally. This research shows that the proposed method is an effective method to determine the torque constant and the torque-speed-current characteristics of the BLDC motor without using dynamometer.

  16. Are Naturopathic Universities ``The Natural Places'' to investigate Attention-Deficit Type Disorders, with Possible Linkages to Cultural Patterns and the EMF?

    NASA Astrophysics Data System (ADS)

    de Souza, Beatriz; Balam Matagamon, Chan; Pawa Matagamon, Sagamo

    2006-03-01

    We desire serious investigations of behavioral impacts of certain localized or larger-scale environmental elements, such as the electromagnetic spectrum as detected by us at some sites. One author was impacted by the earth's EMF to such an extent in FL that it falsely convinced him that he was having a heart attack more severe than his nearly fatal one. Instead, it preceded an earthquake he then predicted six hours in advance. Chitto Tustenugee's `everglades' site, in Miramar FL, evokes tinnitus. Elsewhere, unease, terror, inappropriate behavior or sporadic loss of attention occurs where it can impact runway or roadway safety. Physics and Naturopathic Universities could be appropriate partners for understanding, preventing or curing these.

  17. Mt Pamola, the Electromagnetic Field, EMF, Thunderbird, Mothman and Environmental Monitoring Signals Via the Southern Constellation Phoenix As Detectable In Potato Cave, Acton, MA.

    NASA Astrophysics Data System (ADS)

    Pecora, Andrea S.; Pawa Matagamon, Sagamo

    2004-03-01

    Just below the peak of Mt Pamola in ME, at the juncture with the Knife Edge, downwardly arcing segments of Earths EMF, are manifested by a faint lotus-blossom-blue, neon-like glow at 3 pm some sunny afternoons. Similarly hued glows, and horizontal but variable-arced segmented trajectories, are somewhat periodically detectable under certain conditions in chambers at Acton, MA. These phenomena curiously have the filled-in profile that precisely matches the outline of the southern constellation Phoenix, which is never visible above the nighttime horizon locally. The stick-figure representation of the constellation Canis Major can also be detected in a chamber at Americas Stonehenge, two hours before it has arisen, at certain times. The sequence of phenomena visible at Acton correctly correlates with eclipses and other alignments of our solar system. Phoenix, a.k.a. Thunderbird and Mothman, is detectable elsewhere in MA.

  18. New Simple Torque-Sensorless Torque Control for Quasi-Perfect Compensation of 6th Harmonic Torque Ripple Due to Nonsinusoidal Distribution of Back EMF of PMSM

    NASA Astrophysics Data System (ADS)

    Shinnaka, Shinji; Kishida, Hideo

    This paper proposes a new torque-sensorless torque control method for permanent-magnet synchronous motors (PMSMs). The proposed method can almost perfectly compensate the 6th harmonic torque ripple that is caused by the nonsinusoidal distributions of the back EMF and rotor magnetic flux of PMSMs. The torque control system is, in principle, constructed on the basis of the vector control, but has two new dedicated speed-varying devices—a harmonic torque observer and current controller. The speed-varying harmonic torque observer can estimate the harmonic component over a wide speed range, even in the case where the produced torque is constant, and generate a suitable compensating signal. The speed-varying current controller shows stable control performance over a wide speed range, it can fully track the compensated current command containing the dc and 6th harmonic components. The effectiveness of the proposed method is examined and verified through extensive numerical experiments.

  19. Gyrokinetic Statistical Absolute Equilibrium and Turbulence

    SciTech Connect

    Jian-Zhou Zhu and Gregory W. Hammett

    2011-01-10

    A paradigm based on the absolute equilibrium of Galerkin-truncated inviscid systems to aid in understanding turbulence [T.-D. Lee, "On some statistical properties of hydrodynamical and magnetohydrodynamical fields," Q. Appl. Math. 10, 69 (1952)] is taken to study gyrokinetic plasma turbulence: A finite set of Fourier modes of the collisionless gyrokinetic equations are kept and the statistical equilibria are calculated; possible implications for plasma turbulence in various situations are discussed. For the case of two spatial and one velocity dimension, in the calculation with discretization also of velocity v with N grid points (where N + 1 quantities are conserved, corresponding to an energy invariant and N entropy-related invariants), the negative temperature states, corresponding to the condensation of the generalized energy into the lowest modes, are found. This indicates a generic feature of inverse energy cascade. Comparisons are made with some classical results, such as those of Charney-Hasegawa-Mima in the cold-ion limit. There is a universal shape for statistical equilibrium of gyrokinetics in three spatial and two velocity dimensions with just one conserved quantity. Possible physical relevance to turbulence, such as ITG zonal flows, and to a critical balance hypothesis are also discussed.

  20. Towards absolute calibration of optical tweezers.

    PubMed

    Viana, N B; Rocha, M S; Mesquita, O N; Mazolli, A; Maia Neto, P A; Nussenzveig, H M

    2007-02-01

    Aiming at absolute force calibration of optical tweezers, following a critical review of proposed theoretical models, we present and test the results of Mie-Debye-spherical aberration (MDSA) theory, an extension of a previous (MD) model, taking account of spherical aberration at the glass-water interface. This first-principles theory is formulated entirely in terms of experimentally accessible parameters (none adjustable). Careful experimental tests of the MDSA theory, undertaken at two laboratories, with very different setups, are described. A detailed description is given of the procedures employed to measure laser beam waist, local beam power at the transparent microspheres trapped by the tweezers, microsphere radius, and the trap transverse stiffness, as a function of radius and height in the (inverted microscope) sample chamber. We find generally very good agreement with MDSA theory predictions, for a wide size range, from the Rayleigh domain to large radii, including the values most often employed in practice, and at different chamber heights, both with objective overfilling and underfilling. The results asymptotically approach geometrical optics in the mean over size intervals, as they should, and this already happens for size parameters not much larger than unity. MDSA predictions for the trapping threshold, position of stiffness peak, stiffness variation with height, multiple equilibrium points, and "hopping" effects among them are verified. Remaining discrepancies are ascribed to focus degradation, possibly arising from objective aberrations in the infrared, not yet included in MDSA theory. PMID:17358374

  1. Towards absolute calibration of optical tweezers

    NASA Astrophysics Data System (ADS)

    Viana, N. B.; Rocha, M. S.; Mesquita, O. N.; Mazolli, A.; Maia Neto, P. A.; Nussenzveig, H. M.

    2007-02-01

    Aiming at absolute force calibration of optical tweezers, following a critical review of proposed theoretical models, we present and test the results of Mie-Debye-spherical aberration (MDSA) theory, an extension of a previous (MD) model, taking account of spherical aberration at the glass-water interface. This first-principles theory is formulated entirely in terms of experimentally accessible parameters (none adjustable). Careful experimental tests of the MDSA theory, undertaken at two laboratories, with very different setups, are described. A detailed description is given of the procedures employed to measure laser beam waist, local beam power at the transparent microspheres trapped by the tweezers, microsphere radius, and the trap transverse stiffness, as a function of radius and height in the (inverted microscope) sample chamber. We find generally very good agreement with MDSA theory predictions, for a wide size range, from the Rayleigh domain to large radii, including the values most often employed in practice, and at different chamber heights, both with objective overfilling and underfilling. The results asymptotically approach geometrical optics in the mean over size intervals, as they should, and this already happens for size parameters not much larger than unity. MDSA predictions for the trapping threshold, position of stiffness peak, stiffness variation with height, multiple equilibrium points, and “hopping” effects among them are verified. Remaining discrepancies are ascribed to focus degradation, possibly arising from objective aberrations in the infrared, not yet included in MDSA theory.

  2. Elevation correction factor for absolute pressure measurements

    NASA Technical Reports Server (NTRS)

    Panek, Joseph W.; Sorrells, Mark R.

    1996-01-01

    With the arrival of highly accurate multi-port pressure measurement systems, conditions that previously did not affect overall system accuracy must now be scrutinized closely. Errors caused by elevation differences between pressure sensing elements and model pressure taps can be quantified and corrected. With multi-port pressure measurement systems, the sensing elements are connected to pressure taps that may be many feet away. The measurement system may be at a different elevation than the pressure taps due to laboratory space or test article constraints. This difference produces a pressure gradient that is inversely proportional to height within the interface tube. The pressure at the bottom of the tube will be higher than the pressure at the top due to the weight of the tube's column of air. Tubes with higher pressures will exhibit larger absolute errors due to the higher air density. The above effect is well documented but has generally been taken into account with large elevations only. With error analysis techniques, the loss in accuracy from elevation can be easily quantified. Correction factors can be applied to maintain the high accuracies of new pressure measurement systems.

  3. Absolute quantum energy inequalities in curved spacetime

    E-print Network

    Christopher J. Fewster; Calvin J. Smith

    2007-12-20

    Quantum Energy Inequalities (QEIs) are results which limit the extent to which the smeared renormalised energy density of the quantum field can be negative, when averaged along a timelike curve or over a more general timelike submanifold in spacetime. On globally hyperbolic spacetimes the minimally-coupled massive quantum Klein--Gordon field is known to obey a `difference' QEI that depends on a reference state chosen arbitrarily from the class of Hadamard states. In many spacetimes of interest this bound cannot be evaluated explicitly. In this paper we obtain the first `absolute' QEI for the minimally-coupled massive quantum Klein--Gordon field on four dimensional globally hyperbolic spacetimes; that is, a bound which depends only on the local geometry. The argument is an adaptation of that used to prove the difference QEI and utilises the Sobolev wave-front set to give a complete characterisation of the singularities of the Hadamard series. Moreover, the bound is explicit and can be formulated covariantly under additional (general) conditions. We also generalise our results to incorporate adiabatic states.

  4. Proteomics of human primary osteoarthritic chondrocytes exposed to extremely low-frequency electromagnetic fields (ELF EMFs) and to therapeutic application of musically modulated electromagnetic fields (TAMMEF).

    PubMed

    Corallo, Claudio; Battisti, Emilio; Albanese, Antonietta; Vannoni, Daniela; Leoncini, Roberto; Landi, Giacomo; Gagliardi, Assunta; Landi, Claudia; Carta, Serafino; Nuti, Ranuccio; Giordano, Nicola

    2014-01-01

    Osteoarthritis (OA) is the most frequent joint disease, characterized by degradation of extracellular matrix and alterations in chondrocyte metabolism. Some authors reported that electromagnetic fields (EMFs) can positively interfere with patients affected by OA, even though the nature of the interaction is still debated. Human primary osteoarthritic chondrocytes isolated from the femoral heads of OA-patients undergoing to total hip replacement, were cultured in vitro and exposed 30?min/day for two weeks to extremely-low-frequency electromagnetic field (ELF) with fixed frequency (100?Hz) and to therapeutic application of musically modulated electromagnetic fields (TAMMEF) with variable frequencies, intensities and waveforms. Sham-exposed (S.E.) cells served as control group. Cell viability was measured at days 2, 7 and 14. After two weeks, cell lysates were processed using a proteomic approach. Chondrocyte exposed to ELF and TAMMEF system demonstrated different viability compared to untreated chondrocytes (S.E.). Proteome analysis of 2D-Electrophoresis and protein identification by mass spectrometry showed different expression of proteins derived from nucleus, cytoplasm and organelles. Function analysis of the identified proteins showed changes in related-proteins metabolism (glyceraldeyde-3-phosphate-dehydrogenase), stress response (Mn-superoxide-dismutase, heat-shock proteins), cytoskeletal regulation (actin), proteinase inhibition (cystatin-B) and inflammation regulatory functions (S100-A10, S100-A11) among the experimental groups (ELF, TAMMEF and S.E.). In conclusion, EMFs do not cause damage to chondrocytes, besides stimulate safely OA-chondrocytes and are responsible of different protein expression among the three groups. Furthermore, protein analysis of OA-chondrocytes treated with ELF and the new TAMMEF systems could be useful to clarify the pathogenetic mechanisms of OA by identifying biomarkers of the disease. PMID:23713417

  5. Absolute calorimetric calibration of low energy brachytherapy sources

    NASA Astrophysics Data System (ADS)

    Stump, Kurt E.

    In the past decade there has been a dramatic increase in the use of permanent radioactive source implants in the treatment of prostate cancer. A small radioactive source encapsulated in a titanium shell is used in this type of treatment. The radioisotopes used are generally 125I or 103Pd. Both of these isotopes have relatively short half-lives, 59.4 days and 16.99 days, respectively, and have low-energy emissions and a low dose rate. These factors make these sources well suited for this application, but the calibration of these sources poses significant metrological challenges. The current standard calibration technique involves the measurement of ionization in air to determine the source air-kerma strength. While this has proved to be an improvement over previous techniques, the method has been shown to be metrologically impure and may not be the ideal means of calbrating these sources. Calorimetric methods have long been viewed to be the most fundamental means of determining source strength for a radiation source. This is because calorimetry provides a direct measurement of source energy. However, due to the low energy and low power of the sources described above, current calorimetric methods are inadequate. This thesis presents work oriented toward developing novel methods to provide direct and absolute measurements of source power for low-energy low dose rate brachytherapy sources. The method is the first use of an actively temperature-controlled radiation absorber using the electrical substitution method to determine total contained source power of these sources. The instrument described operates at cryogenic temperatures. The method employed provides a direct measurement of source power. The work presented here is focused upon building a metrological foundation upon which to establish power-based calibrations of clinical-strength sources. To that end instrument performance has been assessed for these source strengths. The intent is to establish the limits of the current instrument to direct further work in this field. It has been found that for sources with powers above approximately 2 muW the instrument is able to determine the source power in agreement to within less than 7% of what is expected based upon the current source strength standard. For lower power sources, the agreement is still within the uncertainty of the power measurement, but the calorimeter noise dominates. Thus, to provide absolute calibration of lower power sources additional measures must be taken. The conclusion of this thesis describes these measures and how they will improve the factors that limit the current instrument. The results of the work presented in this thesis establish the methodology of active radiometric calorimetey for the absolute calibration of radioactive sources. The method is an improvement over previous techniques in that there is no reliance upon the thermal properties of the materials used or the heat flow pathways on the source measurements. The initial work presented here will help to shape future refinements of this technique to allow lower power sources to be calibrated with high precision and high accuracy.

  6. Quantifying Absolute Protein Synthesis Rates Reveals Principles Underlying

    E-print Network

    Zhang, Jianzhi

    Quantifying Absolute Protein Synthesis Rates Reveals Principles Underlying Allocation of Cellular present a genome-wide approach, based on ribosome profiling, for measuring absolute protein synthesis- lyses of protein synthesis. INTRODUCTION Protein biosynthesis is by far the largest consumer of energy

  7. Absolute detector quantum-efficiency measurements using correlated photons

    E-print Network

    Migdall, Alan

    metrologia Absolute detector quantum-efficiency measurements using correlated photons A. L. Migdall correlated photons for radiometric purposes has been set up at the National Institute of Standards and Technology (NIST). We use pairs of correlated photons to produce spatial maps of the absolute efficiency

  8. Absolute Humidity and the Seasonality of Influenza (Invited)

    NASA Astrophysics Data System (ADS)

    Shaman, J. L.; Pitzer, V.; Viboud, C.; Grenfell, B.; Goldstein, E.; Lipsitch, M.

    2010-12-01

    Much of the observed wintertime increase of mortality in temperate regions is attributed to seasonal influenza. A recent re-analysis of laboratory experiments indicates that absolute humidity strongly modulates the airborne survival and transmission of the influenza virus. Here we show that the onset of increased wintertime influenza-related mortality in the United States is associated with anomalously low absolute humidity levels during the prior weeks. We then use an epidemiological model, in which observed absolute humidity conditions temper influenza transmission rates, to successfully simulate the seasonal cycle of observed influenza-related mortality. The model results indicate that direct modulation of influenza transmissibility by absolute humidity alone is sufficient to produce this observed seasonality. These findings provide epidemiological support for the hypothesis that absolute humidity drives seasonal variations of influenza transmission in temperate regions. In addition, we show that variations of the basic and effective reproductive numbers for influenza, caused by seasonal changes in absolute humidity, are consistent with the general timing of pandemic influenza outbreaks observed for 2009 A/H1N1 in temperate regions. Indeed, absolute humidity conditions correctly identify the region of the United States vulnerable to a third, wintertime wave of pandemic influenza. These findings suggest that the timing of pandemic influenza outbreaks is controlled by a combination of absolute humidity conditions, levels of susceptibility and changes in population mixing and contact rates.

  9. Determination of Absolute Zero Using a Computer-Based Laboratory

    ERIC Educational Resources Information Center

    Amrani, D.

    2007-01-01

    We present a simple computer-based laboratory experiment for evaluating absolute zero in degrees Celsius, which can be performed in college and undergraduate physical sciences laboratory courses. With a computer, absolute zero apparatus can help demonstrators or students to observe the relationship between temperature and pressure and use…

  10. Absolute Plate Velocities from Seismic Anisotropy

    NASA Astrophysics Data System (ADS)

    Kreemer, Corné; Zheng, Lin; Gordon, Richard

    2015-04-01

    The orientation of seismic anisotropy inferred beneath plate interiors may provide a means to estimate the motions of the plate relative to the sub-asthenospheric mantle. Here we analyze two global sets of shear-wave splitting data, that of Kreemer [2009] and an updated and expanded data set, to estimate plate motions and to better understand the dispersion of the data, correlations in the errors, and their relation to plate speed. We also explore the effect of using geologically current plate velocities (i.e., the MORVEL set of angular velocities [DeMets et al. 2010]) compared with geodetically current plate velocities (i.e., the GSRM v1.2 angular velocities [Kreemer et al. 2014]). We demonstrate that the errors in plate motion azimuths inferred from shear-wave splitting beneath any one tectonic plate are correlated with the errors of other azimuths from the same plate. To account for these correlations, we adopt a two-tier analysis: First, find the pole of rotation and confidence limits for each plate individually. Second, solve for the best fit to these poles while constraining relative plate angular velocities to consistency with the MORVEL relative plate angular velocities. The SKS-MORVEL absolute plate angular velocities (based on the Kreemer [2009] data set) are determined from the poles from eight plates weighted proportionally to the root-mean-square velocity of each plate. SKS-MORVEL indicates that eight plates (Amur, Antarctica, Caribbean, Eurasia, Lwandle, Somalia, Sundaland, and Yangtze) have angular velocities that differ insignificantly from zero. The net rotation of the lithosphere is 0.25±0.11° Ma-1 (95% confidence limits) right-handed about 57.1°S, 68.6°E. The within-plate dispersion of seismic anisotropy for oceanic lithosphere (?=19.2° ) differs insignificantly from that for continental lithosphere (?=21.6° ). The between-plate dispersion, however, is significantly smaller for oceanic lithosphere (?=7.4° ) than for continental lithosphere (?=14.7° ). Two of the slowest-moving plates, Antarctica (vRMS=4 mm a-1, ?=29° ) and Eurasia (vRMS=3 mm a-1, ?=33° ), have two of the largest within-plate dispersions, which may indicate that a plate must move faster than ˜5 mm a-1 to result in seismic anisotropy useful for estimating plate motion. We will investigate if these relationships still hold with the new expanded data set and with the alternative set of relative plate angular velocities. We have found systematic differences between the SKS orientations and our predicted plate motion azimuths underneath the Arabia plate, which suggests to us either plate-scale mantle flow process not directly associated with that plate's absolute motion or intrinsic lithospheric anisotropy. We will discuss more of such discrepancies underneath other plates using the enlarged data set.

  11. Absolute determination of local tropospheric OH concentrations

    NASA Technical Reports Server (NTRS)

    Armerding, Wolfgang; Comes, Franz-Josef

    1994-01-01

    Long path absorption (LPA) according to Lambert Beer's law is a method to determine absolute concentrations of trace gases such as tropospheric OH. We have developed a LPA instrument which is based on a rapid tuning of the light source which is a frequency doubled dye laser. The laser is tuned across two or three OH absorption features around 308 nm with a scanning speed of 0.07 cm(exp -1)/microsecond and a repetition rate of 1.3 kHz. This high scanning speed greatly reduces the fluctuation of the light intensity caused by the atmosphere. To obtain the required high sensitivity the laser output power is additionally made constant and stabilized by an electro-optical modulator. The present sensitivity is of the order of a few times 10(exp 5) OH per cm(exp 3) for an acquisition time of a minute and an absorption path length of only 1200 meters so that a folding of the optical path in a multireflection cell was possible leading to a lateral dimension of the cell of a few meters. This allows local measurements to be made. Tropospheric measurements have been carried out in 1991 resulting in the determination of OH diurnal variation at specific days in late summer. Comparison with model calculations have been made. Interferences are mainly due to SO2 absorption. The problem of OH self generation in the multireflection cell is of minor extent. This could be shown by using different experimental methods. The minimum-maximum signal to noise ratio is about 8 x 10(exp -4) for a single scan. Due to the small size of the absorption cell the realization of an open air laboratory is possible in which by use of an additional UV light source or by additional fluxes of trace gases the chemistry can be changed under controlled conditions allowing kinetic studies of tropospheric photochemistry to be made in open air.

  12. Orion Absolute Navigation System Progress and Challenge

    NASA Technical Reports Server (NTRS)

    Holt, Greg N.; D'Souza, Christopher

    2012-01-01

    The absolute navigation design of NASA's Orion vehicle is described. It has undergone several iterations and modifications since its inception, and continues as a work-in-progress. This paper seeks to benchmark the current state of the design and some of the rationale and analysis behind it. There are specific challenges to address when preparing a timely and effective design for the Exploration Flight Test (EFT-1), while still looking ahead and providing software extensibility for future exploration missions. The primary onboard measurements in a Near-Earth or Mid-Earth environment consist of GPS pseudo-range and delta-range, but for future explorations missions the use of star-tracker and optical navigation sources need to be considered. Discussions are presented for state size and composition, processing techniques, and consider states. A presentation is given for the processing technique using the computationally stable and robust UDU formulation with an Agee-Turner Rank-One update. This allows for computational savings when dealing with many parameters which are modeled as slowly varying Gauss-Markov processes. Preliminary analysis shows up to a 50% reduction in computation versus a more traditional formulation. Several state elements are discussed and evaluated, including position, velocity, attitude, clock bias/drift, and GPS measurement biases in addition to bias, scale factor, misalignment, and non-orthogonalities of the accelerometers and gyroscopes. Another consideration is the initialization of the EKF in various scenarios. Scenarios such as single-event upset, ground command, and cold start are discussed as are strategies for whole and partial state updates as well as covariance considerations. Strategies are given for dealing with latent measurements and high-rate propagation using multi-rate architecture. The details of the rate groups and the data ow between the elements is discussed and evaluated.

  13. Evaluation of the Absolute Regional Temperature Potential

    NASA Technical Reports Server (NTRS)

    Shindell, D. T.

    2012-01-01

    The Absolute Regional Temperature Potential (ARTP) is one of the few climate metrics that provides estimates of impacts at a sub-global scale. The ARTP presented here gives the time-dependent temperature response in four latitude bands (90-28degS, 28degS-28degN, 28-60degN and 60-90degN) as a function of emissions based on the forcing in those bands caused by the emissions. It is based on a large set of simulations performed with a single atmosphere-ocean climate model to derive regional forcing/response relationships. Here I evaluate the robustness of those relationships using the forcing/response portion of the ARTP to estimate regional temperature responses to the historic aerosol forcing in three independent climate models. These ARTP results are in good accord with the actual responses in those models. Nearly all ARTP estimates fall within +/-20%of the actual responses, though there are some exceptions for 90-28degS and the Arctic, and in the latter the ARTP may vary with forcing agent. However, for the tropics and the Northern Hemisphere mid-latitudes in particular, the +/-20% range appears to be roughly consistent with the 95% confidence interval. Land areas within these two bands respond 39-45% and 9-39% more than the latitude band as a whole. The ARTP, presented here in a slightly revised form, thus appears to provide a relatively robust estimate for the responses of large-scale latitude bands and land areas within those bands to inhomogeneous radiative forcing and thus potentially to emissions as well. Hence this metric could allow rapid evaluation of the effects of emissions policies at a finer scale than global metrics without requiring use of a full climate model.

  14. Testing the quasi-absolute method in photon activation analysis

    NASA Astrophysics Data System (ADS)

    Sun, Z. J.; Wells, D.; Starovoitova, V.; Segebade, C.

    2013-04-01

    In photon activation analysis (PAA), relative methods are widely used because of their accuracy and precision. Absolute methods, which are conducted without any assistance from calibration materials, are seldom applied for the difficulty in obtaining photon flux in measurements. This research is an attempt to perform a new absolute approach in PAA - quasi-absolute method - by retrieving photon flux in the sample through Monte Carlo simulation. With simulated photon flux and database of experimental cross sections, it is possible to calculate the concentration of target elements in the sample directly. The QA/QC procedures to solidify the research are discussed in detail. Our results show that the accuracy of the method for certain elements is close to a useful level in practice. Furthermore, the future results from the quasi-absolute method can also serve as a validation technique for experimental data on cross sections. The quasi-absolute method looks promising.

  15. Absolute and convective instabilities of natural convection flow in boundary-layer regime.

    PubMed

    Tao, J; Le Quéré, P; Xin, S

    2004-12-01

    The spatiotemporal instability of the buoyancy-driven flow adjacent to a vertically heated wall, which is immersed in thermally stratified medium, is studied theoretically and numerically. The temperature gradients ratio between the wall and the ambient fluid is shown to lead to rich scenario of absolute-convective instability transitions. The direct numerical simulations consistent with the theoretical prediction are presented. The supercritical steady state, found in previous simulations of the natural convection in vertically heated square cavity, is explained in terms of the convective instability, and the nonlinear effect on the convectively unstable waves is discussed as well. PMID:15697506

  16. Development of a graphite probe calorimeter for absolute clinical dosimetry.

    PubMed

    Renaud, James; Marchington, David; Seuntjens, Jan; Sarfehnia, Arman

    2013-02-01

    The aim of this work is to present the numerical design optimization, construction, and experimental proof of concept of a graphite probe calorimeter (GPC) conceived for dose measurement in the clinical environment (U.S. provisional patent 61?652,540). A finite element method (FEM) based numerical heat transfer study was conducted using a commercial software package to explore the feasibility of the GPC and to optimize the shape, dimensions, and materials used in its design. A functioning prototype was constructed inhouse and used to perform dose to water measurements under a 6 MV photon beam at 400 and 1000 MU?min, in a thermally insulated water phantom. Heat loss correction factors were determined using FEM analysis while the radiation field perturbation and the graphite to water absorbed dose conversion factors were calculated using Monte Carlo simulations. The difference in the average measured dose to water for the 400 and 1000 MU?min runs using the TG-51 protocol and the GPC was 0.2% and 1.2%, respectively. Heat loss correction factors ranged from 1.001 to 1.002, while the product of the perturbation and dose conversion factors was calculated to be 1.130. The combined relative uncertainty was estimated to be 1.4%, with the largest contributors being the specific heat capacity of the graphite (type B, 0.8%) and the reproducibility, defined as the standard deviation of the mean measured dose (type A, 0.6%). By establishing the feasibility of using the GPC as a practical clinical absolute photon dosimeter, this work lays the foundation for further device enhancements, including the development of an isothermal mode of operation and an overall miniaturization, making it potentially suitable for use in small and composite radiation fields. It is anticipated that, through the incorporation of isothermal stabilization provided by temperature controllers, a subpercent overall uncertainty will be achieved. PMID:23387722

  17. Development of a graphite probe calorimeter for absolute clinical dosimetry

    SciTech Connect

    Renaud, James; Seuntjens, Jan; Sarfehnia, Arman; Marchington, David

    2013-02-15

    The aim of this work is to present the numerical design optimization, construction, and experimental proof of concept of a graphite probe calorimeter (GPC) conceived for dose measurement in the clinical environment (U.S. provisional patent 61/652,540). A finite element method (FEM) based numerical heat transfer study was conducted using a commercial software package to explore the feasibility of the GPC and to optimize the shape, dimensions, and materials used in its design. A functioning prototype was constructed inhouse and used to perform dose to water measurements under a 6 MV photon beam at 400 and 1000 MU/min, in a thermally insulated water phantom. Heat loss correction factors were determined using FEM analysis while the radiation field perturbation and the graphite to water absorbed dose conversion factors were calculated using Monte Carlo simulations. The difference in the average measured dose to water for the 400 and 1000 MU/min runs using the TG-51 protocol and the GPC was 0.2% and 1.2%, respectively. Heat loss correction factors ranged from 1.001 to 1.002, while the product of the perturbation and dose conversion factors was calculated to be 1.130. The combined relative uncertainty was estimated to be 1.4%, with the largest contributors being the specific heat capacity of the graphite (type B, 0.8%) and the reproducibility, defined as the standard deviation of the mean measured dose (type A, 0.6%). By establishing the feasibility of using the GPC as a practical clinical absolute photon dosimeter, this work lays the foundation for further device enhancements, including the development of an isothermal mode of operation and an overall miniaturization, making it potentially suitable for use in small and composite radiation fields. It is anticipated that, through the incorporation of isothermal stabilization provided by temperature controllers, a subpercent overall uncertainty will be achieved.

  18. MEASUREMENTS OF ABSOLUTE ABUNDANCES IN SOLAR FLARES

    SciTech Connect

    Warren, Harry P.

    2014-05-01

    We present measurements of elemental abundances in solar flares with the EUV Variability Experiment (EVE) on the Solar Dynamics Observatory. EVE observes both high temperature Fe emission lines (Fe XV-Fe XXIV) and continuum emission from thermal bremsstrahlung that is proportional to the abundance of H. By comparing the relative intensities of line and continuum emission it is possible to determine the enrichment of the flare plasma relative to the composition of the photosphere. This is the first ionization potential or FIP bias (f). Since thermal bremsstrahlung at EUV wavelengths is relatively insensitive to the electron temperature, it is important to account for the distribution of electron temperatures in the emitting plasma. We accomplish this by using the observed spectra to infer the differential emission measure distribution and FIP bias simultaneously. In each of the 21 flares that we analyze we find that the observed composition is close to photospheric. The mean FIP bias in our sample is f = 1.17 ± 0.22. This analysis suggests that the bulk of the plasma evaporated during a flare comes from deep in the chromosphere, below the region where elemental fractionation occurs.

  19. Measuring health disparities: a comparison of absolute and relative disparities

    PubMed Central

    Beckles, Gloria L.A.

    2015-01-01

    Monitoring national trends in disparities in different diseases could provide measures to evaluate the impact of intervention programs designed to reduce health disparities. In the US, most of the reports that track health disparities provided either relative or absolute disparities or both. However, these two measures of disparities are not only different in scale and magnitude but also the temporal changes in the magnitudes of these measures can occur in opposite directions. The trends for absolute disparity and relative disparity could move in opposite directions when the prevalence of disease in the two populations being compared either increase or decline simultaneously. If the absolute disparity increases but relative disparity declines for consecutive time periods, the absolute disparity increases but relative disparity declines for the combined time periods even with a larger increase in absolute disparity during the combined time periods. Based on random increases or decreases in prevalence of disease for two population groups, there is a higher chance the trends of these two measures could move in opposite directions when the prevalence of disease for the more advantaged group is very small relative to the prevalence of disease for the more disadvantaged group. When prevalence of disease increase or decrease simultaneously for two populations, the increase or decrease in absolute disparity has to be sufficiently large enough to warrant a corresponding increase or decrease in relative disparity. When absolute disparity declines but relative disparity increases, there is some progress in reducing disparities, but the reduction in absolute disparity is not large enough to also reduce relative disparity. When evaluating interventions to reduce health disparities using these two measures, it is important to consider both absolute and relative disparities and consider all the scenarios discussed in this paper to assess the progress towards reducing or eliminating health disparities. PMID:26623191

  20. Kinetic regularities of thermal transformations in nanosized lead films

    NASA Astrophysics Data System (ADS)

    Surovoi, E. P.; Bin, S. V.; Bugerko, L. N.; Surovaya, V. E.

    2015-01-01

    The transformations in nanosized lead films were studied by optical spectroscopy, microscopy, and gravimetry at different film thicknesses ( d = 2-115 nm) and thermal treatment temperatures ( T = 373-573 K). The kinetic curves of conversion were adequately described in terms of the linear, inverse logarithmic, parabolic, and logarithmic laws. The contact potential difference was measured for Pb and PbO films and photo-EMF was measured for Pb-PbO systems. The energy band diagram was constructed for Pb-PbO systems. A model of the thermal transformation of Pb films was suggested, which included the stages of oxygen adsorption, charge carrier distribution in the contact field of Pb-PbO, and formation of lead(II) oxide.

  1. ABSOLUTE PROPERTIES OF THE ECCENTRIC ECLIPSING BINARY STAR FT ORIONIS

    SciTech Connect

    Sabby, Jeffrey A.; Lacy, Claud H. Sandberg; Ibanoglu, Cafer; Claret, Antonio E-mail: clacy@uark.edu E-mail: claret@iaa.es

    2011-06-15

    Accurate absolute properties are determined for the first time for the 3.15 day period eccentric eclipsing binary star FT Ori based on new absolute photometry, five differential light curves, and a radial velocity curve. The stars appear to be normal for their spectral types, A0 + A2. The orbit is highly eccentric (e = 0.409) and shows apsidal motion with a period of 536 years. The absolute properties and the degree of central mass concentration of the stars are consistent with current theoretical models at an age of 190 Myr.

  2. An All Fiber White Light Interferometric Absolute Temperature Measurement System

    PubMed Central

    Kim, Jeonggon Harrison

    2008-01-01

    Recently the author of this article proposed a new signal processing algorithm for an all fiber white light interferometer. In this article, an all fiber white light interferometric absolute temperature measurement system is presented using the previously proposed signal processing algorithm. Stability and absolute temperature measurement were demonstrated. These two tests demonstrated the feasibility of absolute temperature measurement with an accuracy of 0.015 fringe and 0.0005 fringe, respectively. A hysteresis test from 373K to 873K was also presented. Finally, robustness of the sensor system towards laser diode temperature drift, AFMZI temperature drift and PZT non-linearity was demonstrated.

  3. Absolute instability of a liquid jet in a coflowing stream.

    PubMed

    Utada, Andrew S; Fernandez-Nieves, Alberto; Gordillo, Jose M; Weitz, David A

    2008-01-11

    Cylindrical liquid jets are inherently unstable and eventually break into drops due to the Rayleigh-Plateau instability, characterized by the growth of disturbances that are either convective or absolute in nature. Convective instabilities grow in amplitude as they are swept along by the flow, while absolute instabilities are disturbances that grow at a fixed spatial location. Liquid jets are nearly always convectively unstable. Here we show that two-phase jets can breakup due to an absolute instability that depends on the capillary number of the outer liquid, provided the Weber number of the inner liquid is >O(1). We verify our experimental observations with a linear stability analysis. PMID:18232775

  4. Temporal Dynamics of Microbial Rhodopsin Fluorescence Reports Absolute Membrane Voltage

    PubMed Central

    Hou, Jennifer H.; Venkatachalam, Veena; Cohen, Adam E.

    2014-01-01

    Plasma membrane voltage is a fundamentally important property of a living cell; its value is tightly coupled to membrane transport, the dynamics of transmembrane proteins, and to intercellular communication. Accurate measurement of the membrane voltage could elucidate subtle changes in cellular physiology, but existing genetically encoded fluorescent voltage reporters are better at reporting relative changes than absolute numbers. We developed an Archaerhodopsin-based fluorescent voltage sensor whose time-domain response to a stepwise change in illumination encodes the absolute membrane voltage. We validated this sensor in human embryonic kidney cells. Measurements were robust to variation in imaging parameters and in gene expression levels, and reported voltage with an absolute accuracy of 10 mV. With further improvements in membrane trafficking and signal amplitude, time-domain encoding of absolute voltage could be applied to investigate many important and previously intractable bioelectric phenomena. PMID:24507604

  5. Asteroid Absolute Magnitudes and Geometric Slbedos from Lowell Observatory Database

    NASA Astrophysics Data System (ADS)

    Bowell, E.; Oszkiewicz, D. A.; Wasserman, L. H.; Muinonen, K.; Penttilä, A.; Trilling, D.; Thomas, C.; Pieniluoma, T.

    2012-05-01

    We fit phase functions to photometric data for about half a million asteroids contained in the Lowell Observatory database. We obtain absolute magnitudes for large number of asteroids and geometric albedos for selected objects.

  6. Reliable absolute palaeointensities independent of magnetic domain state

    E-print Network

    Utrecht, Universiteit

    to 5% for artificial samples and natural rocks containing multidomain magnetic particles that wereReliable absolute palaeointensities independent of magnetic domain state Mark J. Dekkers a time. This provides essential constraints for numerical geodynamo models. To date, most palaeointensity

  7. Absolute Value Boundedness, Operator Decomposition, and Stochastic Media and Equations

    NASA Technical Reports Server (NTRS)

    Adomian, G.; Miao, C. C.

    1973-01-01

    The research accomplished during this period is reported. Published abstracts and technical reports are listed. Articles presented include: boundedness of absolute values of generalized Fourier coefficients, propagation in stochastic media, and stationary conditions for stochastic differential equations.

  8. ALMOST REDUCIBILITY AND ABSOLUTE CONTINUITY I ARTUR AVILA

    E-print Network

    Avila, Artur

    ALMOST REDUCIBILITY AND ABSOLUTE CONTINUITY I ARTUR AVILA 1. Introduction Here we consider one of a "global theory", and recent breakthroughs in parameter analysis led to a concrete such 1 #12;2 ARTUR AVILA

  9. On-Orbit Absolute Temperature Calibration Using Multiple Phase Change Materials

    NASA Astrophysics Data System (ADS)

    Best, F. A.; Adler, D. P.; Pettersen, C.; Revercomb, H. E.; Perepezko, J. H.

    2009-12-01

    NASA’s anticipated plan for a mission dedicated to Climate (CLARREO) will hinge upon the ability to fly SI traceable standards that provide irrefutable absolute measurement accuracy. As an example, instrumentation designed to measure spectrally resolved infrared radiances will require high-emissivity calibration blackbodies that have absolute temperature uncertainties of better than 0.045K (3 sigma). A novel scheme to provide absolute calibration of temperature sensors, suitable for CLARREO on-orbit operation, has been demonstrated in the laboratory at the University of Wisconsin, and is now undergoing refinement under NASA Instrument Incubator Program funding. In this scheme, small quantities of reference materials (mercury, water, and gallium) are imbedded into the blackbody cavity wall, in a manner similar to the temperature sensors to be calibrated. As the blackbody cavity is slowly heated through the melt point of each reference material, the transient temperature signature from the imbedded thermistor sensors provides a very accurate indication of the melt temperature. Using small quantities of phase change material (less than half of a percent of the mass of the cavity), melt temperature accuracies of better than 10 mK have been demonstrated for mercury, water, and gallium (providing calibration from 233K to 303K). Refinements currently underway focus on ensuring that the melt materials in their sealed confinement housings perform as expected in the thermal and microgravity environment of a multi-year spaceflight mission. Thermal soak and cycling tests are underway to demonstrate that there is no dissolution from the housings into the melt materials that could alter melt temperature, and that there is no liquid metal embrittlement of the housings from the metal melt materials. In addition, NASA funding has been recently secured to conduct a demonstration of this scheme in the microgravity environment of the International Space Station.

  10. Absolute and Convective Instability of a Liquid Jet in Microgravity

    NASA Technical Reports Server (NTRS)

    Lin, Sung P.; Vihinen, I.; Honohan, A.; Hudman, Michael D.

    1996-01-01

    The transition from convective to absolute instability is observed in the 2.2 second drop tower of the NASA Lewis Research Center. In convective instability the disturbance grows spatially as it is convected downstream. In absolute instability the disturbance propagates both downstream and upstream, and manifests itself as an expanding sphere. The transition Reynolds numbers are determined for two different Weber numbers by use of Glycerin and a Silicone oil. Preliminary comparisons with theory are made.

  11. Absolute/convective instability of planar viscoelastic jets

    NASA Astrophysics Data System (ADS)

    Ray, Prasun K.; Zaki, Tamer A.

    2015-01-01

    Spatiotemporal linear stability analysis is used to investigate the onset of local absolute instability in planar viscoelastic jets. The influence of viscoelasticity in dilute polymer solutions is modeled with the FENE-P constitutive equation which requires the specification of a non-dimensional polymer relaxation time (the Weissenberg number, We), the maximum polymer extensibility, L, and the ratio of solvent and solution viscosities, ?. A two-parameter family of velocity profiles is used as the base state with the parameter, S, controlling the amount of co- or counter-flow while N-1 sets the thickness of the jet shear layer. We examine how the variation of these fluid and flow parameters affects the minimum value of S at which the flow becomes locally absolutely unstable. Initially setting the Reynolds number to Re = 500, we find that the first varicose jet-column mode dictates the presence of absolute instability, and increasing the Weissenberg number produces important changes in the nature of the instability. The region of absolute instability shifts towards thin shear layers, and the amount of back-flow needed for absolute instability decreases (i.e., the influence of viscoelasticity is destabilizing). Additionally, when We is sufficiently large and N-1 is sufficiently small, single-stream jets become absolutely unstable. Numerical experiments with approximate equations show that both the polymer and solvent contributions to the stress become destabilizing when the scaled shear rate, ? = /W e dU¯1/dx 2L ( /d U ¯ 1 d x 2 is the base-state velocity gradient), is sufficiently large. These qualitative trends are largely unchanged when the Reynolds number is reduced; however, the relative importance of the destabilizing stresses increases tangibly. Consequently, absolute instability is substantially enhanced, and single-stream jets become absolutely unstable over a sizable portion of the parameter space.

  12. A simplified model for thermal-wave cavity self-consistent measurement of thermal diffusivity

    SciTech Connect

    Shen, Jun Zhou, Jianqin; Gu, Caikang; Neill, Stuart; Michaelian, Kirk H.; Fairbridge, Craig; Astrath, Nelson G. C.; Baesso, Mauro L.

    2013-12-15

    A simplified theoretical model was developed for the thermal-wave cavity (TWC) technique in this study. This model takes thermal radiation into account and can be employed for absolute measurements of the thermal diffusivity of gas and liquid samples without any knowledge of geometrical and thermal parameters of the components of the TWC. Using this model and cavity-length scans, thermal diffusivities of air and distilled water were accurately and precisely measured as (2.191 ± 0.004) × 10{sup ?5} and (1.427 ± 0.009) × 10{sup ?7} m{sup 2}?s{sup ?1}, respectively, in very good agreement with accepted literature values.

  13. Global absolut gravity reference system as replacement of IGSN 71

    NASA Astrophysics Data System (ADS)

    Wilmes, Herbert; Wziontek, Hartmut; Falk, Reinhard

    2015-04-01

    The determination of precise gravity field parameters is of great importance in a period in which earth sciences are achieving the necessary accuracy to monitor and document global change processes. This is the reason why experts from geodesy and metrology joined in a successful cooperation to make absolute gravity observations traceable to SI quantities, to improve the metrological kilogram definition and to monitor mass movements and smallest height changes for geodetic and geophysical applications. The international gravity datum is still defined by the International Gravity Standardization Net adopted in 1971 (IGSN 71). The network is based upon pendulum and spring gravimeter observations taken in the 1950s and 60s supported by the early free fall absolute gravimeters. Its gravity values agreed in every case to better than 0.1 mGal. Today, more than 100 absolute gravimeters are in use worldwide. The series of repeated international comparisons confirms the traceability of absolute gravity measurements to SI quantities and confirm the degree of equivalence of the gravimeters in the order of a few µGal. For applications in geosciences where e.g. gravity changes over time need to be analyzed, the temporal stability of an absolute gravimeter is most important. Therefore, the proposition is made to replace the IGSN 71 by an up-to-date gravity reference system which is based upon repeated absolute gravimeter comparisons and a global network of well controlled gravity reference stations.

  14. Absolute quantum cutting efficiency of Tb3+-Yb3+ co-doped glass Qianqian Duan, Feng Qin, Hua Zhao, Zhiguo Zhang, and Wenwu Cao

    E-print Network

    Cao, Wenwu

    -Si) solar cells to reduce thermal losses and obtain doubled current in the high energy region of the solar decreases rather than increases as theory predicted. In fact, the absolute quantum efficiency was far less spectrum. Therefore, it is a promising option to enhance the efficiency of c-Si solar cells.1­5 Due

  15. Non-Markovian qubit dynamics in a thermal field bath: Relaxation, decoherence, and entanglement

    SciTech Connect

    Shresta, S.; Anastopoulos, C.; Dragulescu, A.; Hu, B.L.

    2005-02-01

    We study the non-Markovian dynamics of a qubit made up of a two-level atom interacting with an electromagnetic field (EMF) initially at finite temperature. Unlike most earlier studies where the bath is assumed to be fixed, we study the complete evolution of the combined qubit-EMF system, thus allowing for the coherent backaction from the bath on the qubit and the qubit on the bath in a self-consistent manner. In this way we can see the development of quantum correlations and entanglement between the system and its environment, and how that affects the decoherence and relaxation of the system. We find nonexponential decay for both the diagonal and nondiagonal matrix elements of the qubit's reduced density matrix in the pointer basis. The former shows the qubit relaxing to thermal equilibrium with the bath, while the latter shows the decoherence rate beginning at the usually predicted thermal rate, but changing to the zero-temperature value as the qubit and bath become entangled. The decoherence and relaxation rates are comparable, as in the zero-temperature case. On the entanglement of a qubit with the EMF we calculated the fidelity and the von Neumann entropy, which is a measure of the purity of the density matrix. The present more accurate non-Markovian calculations predict lower loss of fidelity and purity as compared with the Markovian results. Generally speaking, with the inclusion of quantum correlations between the qubit and its environment, the non-Markovian processes tend to slow down the drive of the system to equilibrium, prolonging the decoherence and better preserving the fidelity and purity of the system.

  16. Absolute irradiance of the Moon for on-orbit calibration

    USGS Publications Warehouse

    Stone, T.C.; Kieffer, H.H.

    2002-01-01

    The recognized need for on-orbit calibration of remote sensing imaging instruments drives the ROLO project effort to characterize the Moon for use as an absolute radiance source. For over 5 years the ground-based ROLO telescopes have acquired spatially-resolved lunar images in 23 VNIR (Moon diameter ???500 pixels) and 9 SWIR (???250 pixels) passbands at phase angles within ??90 degrees. A numerical model for lunar irradiance has been developed which fits hundreds of ROLO images in each band, corrected for atmospheric extinction and calibrated to absolute radiance, then integrated to irradiance. The band-coupled extinction algorithm uses absorption spectra of several gases and aerosols derived from MODTRAN to fit time-dependent component abundances to nightly observations of standard stars. The absolute radiance scale is based upon independent telescopic measurements of the star Vega. The fitting process yields uncertainties in lunar relative irradiance over small ranges of phase angle and the full range of lunar libration well under 0.5%. A larger source of uncertainty enters in the absolute solar spectral irradiance, especially in the SWIR, where solar models disagree by up to 6%. Results of ROLO model direct comparisons to spacecraft observations demonstrate the ability of the technique to track sensor responsivity drifts to sub-percent precision. Intercomparisons among instruments provide key insights into both calibration issues and the absolute scale for lunar irradiance.

  17. Absolute Coefficients and the Graphical Representation of Airfoil Characteristics

    NASA Technical Reports Server (NTRS)

    Munk, Max

    1921-01-01

    It is argued that there should be an agreement as to what conventions to use in determining absolute coefficients used in aeronautics and in how to plot those coefficients. Of particular importance are the absolute coefficients of lift and drag. The author argues for the use of the German method over the kind in common use in the United States and England, and for the Continental over the usual American and British method of graphically representing the characteristics of an airfoil. The author notes that, on the whole, it appears that the use of natural absolute coefficients in a polar diagram is the logical method for presentation of airfoil characteristics, and that serious consideration should be given to the advisability of adopting this method in all countries, in order to advance uniformity and accuracy in the science of aeronautics.

  18. Absolute stimulated Raman scattering instability in a finite collisional plasma

    SciTech Connect

    McKinstrie, C.J.; Simon, A.

    1985-01-01

    The nonlinear saturation of the absolute stimulated Raman scattering (SRS) instability is considered in a finite homogeneous plasma. The amplitude of the incident wave exceeds the absolute instability threshold by the fractional amount (<<1). A single backscattered wave and a single plasma wave grow until time-asymptotic saturation occurs. The reflected light intensity is determined analytically and is proportional to . The spatial variation of the saturated wave amplitudes is also determined. The reflected intensity is compared to the values predicted for the convective instability, for the same incident intensity. In short plasmas, i.e., ones which extend over only a few convective gain lengths, the reflected intensity is much higher when the absolute instability threshold is exceeded. A reflection coefficient for the SRS instability is discussed for the case when both spatial and temporal effects are important. The paper consists of 15 viewgraphs. 2 refs.

  19. System and method for calibrating a rotary absolute position sensor

    NASA Technical Reports Server (NTRS)

    Davis, Donald R. (Inventor); Permenter, Frank Noble (Inventor); Radford, Nicolaus A (Inventor)

    2012-01-01

    A system includes a rotary device, a rotary absolute position (RAP) sensor generating encoded pairs of voltage signals describing positional data of the rotary device, a host machine, and an algorithm. The algorithm calculates calibration parameters usable to determine an absolute position of the rotary device using the encoded pairs, and is adapted for linearly-mapping an ellipse defined by the encoded pairs to thereby calculate the calibration parameters. A method of calibrating the RAP sensor includes measuring the rotary position as encoded pairs of voltage signals, linearly-mapping an ellipse defined by the encoded pairs to thereby calculate the calibration parameters, and calculating an absolute position of the rotary device using the calibration parameters. The calibration parameters include a positive definite matrix (A) and a center point (q) of the ellipse. The voltage signals may include an encoded sine and cosine of a rotary angle of the rotary device.

  20. Absolute electron scattering cross sections for the CF2 radical.

    PubMed

    Maddern, Todd M; Hargreaves, Leigh R; Francis-Staite, Jessica R; Brunger, Michael J; Buckman, Stephen J; Winstead, Carl; McKoy, Vincent

    2008-02-15

    Using a crossed electron-molecular beam experiment, featuring a skimmed nozzle beam with pyrolytic radical production, absolute elastic cross sections for electron scattering from the CF2 molecule have been measured. A new technique for placing measured cross sections on an absolute scale is used for molecular beams produced as skimmed supersonic jets. Absolute differential cross sections for CF2 are reported for incident electron energies of 30-50 eV and over an angular range of 20-135 deg. Integral cross sections are subsequently derived from those data. The present data are compared to new theoretical predictions for the differential and integral scattering cross sections, as calculated with the Schwinger multichannel variational method using the static-exchange and static-exchange plus polarization approximations. PMID:18352469

  1. Neural Sensitivity to Absolute and Relative Anticipated Reward in Adolescents

    PubMed Central

    Vaidya, Jatin G.; Knutson, Brian; O'Leary, Daniel S.; Block, Robert I.; Magnotta, Vincent

    2013-01-01

    Adolescence is associated with a dramatic increase in risky and impulsive behaviors that have been attributed to developmental differences in neural processing of rewards. In the present study, we sought to identify age differences in anticipation of absolute and relative rewards. To do so, we modified a commonly used monetary incentive delay (MID) task in order to examine brain activity to relative anticipated reward value (neural sensitivity to the value of a reward as a function of other available rewards). This design also made it possible to examine developmental differences in brain activation to absolute anticipated reward magnitude (the degree to which neural activity increases with increasing reward magnitude). While undergoing fMRI, 18 adolescents and 18 adult participants were presented with cues associated with different reward magnitudes. After the cue, participants responded to a target to win money on that trial. Presentation of cues was blocked such that two reward cues associated with $.20, $1.00, or $5.00 were in play on a given block. Thus, the relative value of the $1.00 reward varied depending on whether it was paired with a smaller or larger reward. Reflecting age differences in neural responses to relative anticipated reward (i.e., reference dependent processing), adults, but not adolescents, demonstrated greater activity to a $1 reward when it was the larger of the two available rewards. Adults also demonstrated a more linear increase in ventral striatal activity as a function of increasing absolute reward magnitude compared to adolescents. Additionally, reduced ventral striatal sensitivity to absolute anticipated reward (i.e., the difference in activity to medium versus small rewards) correlated with higher levels of trait Impulsivity. Thus, ventral striatal activity in anticipation of absolute and relative rewards develops with age. Absolute reward processing is also linked to individual differences in Impulsivity. PMID:23544046

  2. Absolute Stability Analysis of a Phase Plane Controlled Spacecraft

    NASA Technical Reports Server (NTRS)

    Jang, Jiann-Woei; Plummer, Michael; Bedrossian, Nazareth; Hall, Charles; Jackson, Mark; Spanos, Pol

    2010-01-01

    Many aerospace attitude control systems utilize phase plane control schemes that include nonlinear elements such as dead zone and ideal relay. To evaluate phase plane control robustness, stability margin prediction methods must be developed. Absolute stability is extended to predict stability margins and to define an abort condition. A constrained optimization approach is also used to design flex filters for roll control. The design goal is to optimize vehicle tracking performance while maintaining adequate stability margins. Absolute stability is shown to provide satisfactory stability constraints for the optimization.

  3. On local temperatures near absolute zero in nonequilibrium quantum systems

    NASA Astrophysics Data System (ADS)

    Shastry, Abhay; Bergfield, Justin; Stafford, Charles

    2014-03-01

    The local temperature of a quantum conductor with source at finite temperature and drain at or near absolute zero is investigated, a problem outside the scope of linear response theory. The local temperature is defined by the measurement of a floating thermoelectric probe. It is shown that cold spots with local temperatures near absolute zero exist within the system, and the applicability of the third law of thermodynamics is investigated. Work supported by U.S. Department of Energy under Award No. DE-SC0006699.

  4. Absolute integrated intensity for the nu-1 sulfur dioxide band

    NASA Technical Reports Server (NTRS)

    Pilon, P. J.; Young, C.

    1976-01-01

    The absolute integrated intensity of the IR vibration-rotation nu-1 SO2 band was measured using the linear portion of the curve of growth. Infrared spectroscopic-absorption cell measurements were performed on sulfur dioxide at partial pressures less than 0.15 torr with nitrogen added to give a total pressure of 705 torr, the path length being 4 mm. The absolute integrated intensity was determined to be 112.0 plus or minus 2.6/cm/sq (atm cm) at 296 K at the 95% confidence level.

  5. Non-Invasive Method of Determining Absolute Intracranial Pressure

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cantrell, John H., Jr. (Inventor); Hargens, Alan E. (Inventor)

    2004-01-01

    A method is presented for determining absolute intracranial pressure (ICP) in a patient. Skull expansion is monitored while changes in ICP are induced. The patient's blood pressure is measured when skull expansion is approximately zero. The measured blood pressure is indicative of a reference ICP value. Subsequently, the method causes a known change in ICP and measured the change in skull expansion associated therewith. The absolute ICP is a function of the reference ICP value, the known change in ICP and its associated change in skull expansion; and a measured change in skull expansion.

  6. Absolute and convective instabilities in an inviscid compressible mixing layer

    E-print Network

    P. Caillol; M. Ruderman

    2007-05-23

    We consider the stability of a compressible shear flow separating two streams of different speeds and temperatures. The velocity and temperature profiles in this mixing layer are hyperbolic tangents. The normal mode analysis of the flow stability reduces to an eigenvalue problem for the pressure perturbation. We briefly describe the numerical method that we used to solve this problem. Then, we introduce the notions of the absolute and convective instabilities and examine the effects of Mach number, and the velocity and temperature ratios of each stream on the transition between convective and absolute instabilities. Finally, we discuss the implication of the results presented in this paper for the heliopause stability.

  7. Absolute and convective instabilities in an inviscid compressible mixing layer

    E-print Network

    Caillol, P

    2007-01-01

    We consider the stability of a compressible shear flow separating two streams of different speeds and temperatures. The velocity and temperature profiles in this mixing layer are hyperbolic tangents. The normal mode analysis of the flow stability reduces to an eigenvalue problem for the pressure perturbation. We briefly describe the numerical method that we used to solve this problem. Then, we introduce the notions of the absolute and convective instabilities and examine the effects of Mach number, and the velocity and temperature ratios of each stream on the transition between convective and absolute instabilities. Finally, we discuss the implication of the results presented in this paper for the heliopause stability.

  8. Absolute and convective instability of a cylinder wake

    NASA Technical Reports Server (NTRS)

    Yang, X.; Zebib, A.

    1989-01-01

    The stability behavior of a circular cross-section cylinder's wake at Reynolds number values of up to 45 is presently investigated by means of local linear stability theory. The steady-wake profiles computed are Navier-Stokes solutions of a uniform, incompressible viscous flow around a cylinder obtained by a spectral method. An absolutely unstable region is found to begin to form at a Reynolds number of about 20, and grows with incresing Reynolds number. The onset of global instability response must be characterized by a critical length of an absolutely unstable region; a critical Reynolds number criterion and preferred frequency are proposed based on linear stability analysis.

  9. Stability comparison of two absolute gravimeters: optical versus atomic interferometers

    NASA Astrophysics Data System (ADS)

    Gillot, P.; Francis, O.; Landragin, A.; Pereira Dos Santos, F.; Merlet, S.

    2014-10-01

    We report the direct comparison between the stabilities of two mobile absolute gravimeters of different technology: the LNE-SYRTE Cold Atom Gravimeter (CAG) and FG5X#216 of the Université du Luxembourg. These instruments rely on two different principles of operation: atomic and optical interferometry. The comparison took place in the Walferdange Underground Laboratory for Geodynamics in Luxembourg, at the beginning of the last International Comparison of Absolute Gravimeters, ICAG-2013. We analyse a 2h10 duration common measurement, and find that the CAG shows better immunity with respect to changes in the level of vibration noise, as well as a slightly better short term stability.

  10. In-flight absolute radiometric calibration of the thematic mapper

    NASA Technical Reports Server (NTRS)

    Castle, K. R.; Holm, R. G.; Kastner, C. J.; Palmer, J. M.; Slater, P. N.; Dinguirard, M.; Ezra, C. E.; Jackson, R. D.; Savage, R. K.

    1983-01-01

    The TM multispectral scanner system was calibrated in an absolute manner before launch. To determine the temporal changes of the absolute radiometric calibration of the entire system, spectroradiometric measurements of the ground and the atmosphere were made simultaneously with TM collections over White Sands, New Mexico. By entering the measured values in an atmospheric radiative transfer program, the radiance levels of the in four of the spectral bands of the TM were determined. Tables show values for the reflectance of snow at White Sands measured by a modular 8 channel radiometer, and values for exoatmospheric irradiance within the TM passbands, calculated for the Earth-Sun distance using a solar radiometer.

  11. Nonexistence of equilibrium states at absolute negative temperatures

    NASA Astrophysics Data System (ADS)

    Romero-Rochín, Víctor

    2013-08-01

    We show that states of macroscopic systems with purported absolute negative temperatures are not stable under small, yet arbitrary, perturbations. We prove the previous statement using the fact that, in equilibrium, the entropy takes its maximum value. We discuss that, while Ramsey theoretical reformulation of the second law for systems with negative temperatures is logically correct, it must be a priori assumed that those states are in thermodynamic equilibrium. Since we argue that those states cannot occur, reversible processes are impossible, and, thus, Ramsey identification of absolute negative temperatures is untenable.

  12. Absolutely maximally entangled states, combinatorial designs, and multiunitary matrices

    NASA Astrophysics Data System (ADS)

    Goyeneche, Dardo; Alsina, Daniel; Latorre, José I.; Riera, Arnau; ?yczkowski, Karol

    2015-09-01

    Absolutely maximally entangled (AME) states are those multipartite quantum states that carry absolute maximum entanglement in all possible bipartitions. AME states are known to play a relevant role in multipartite teleportation, in quantum secret sharing, and they provide the basis novel tensor networks related to holography. We present alternative constructions of AME states and show their link with combinatorial designs. We also analyze a key property of AME states, namely, their relation to tensors, which can be understood as unitary transformations in all of their bipartitions. We call this property multiunitarity.

  13. The Centaur 10199 Chariklo: investigation into rotational period, absolute magnitude, and cometary activity

    NASA Astrophysics Data System (ADS)

    Fornasier, S.; Lazzaro, D.; Alvarez-Candal, A.; Snodgrass, C.; Tozzi, G. P.; Carvano, J. M.; Jiménez-Teja, Y.; Silva, J. S.; Bramich, D. M.

    2014-08-01

    Context. Rings have recently been discovered around the Centaur 10199 Chariklo. Aims: In this paper we present new photometric data, obtained at the 4.2 m SOAR Telescope, aiming to investigate Chariklo's absolute magnitude and rotational period, which is still unknown, and to look for potential cometary activity. Methods: The field background of the images was very crowded so several approaches were used for the extraction of Chariklo fluxes. The background sources were subtracted using difference image analysis and then aperture photometry was applied. A Fourier polynomial fit was used to determine the period. Results: We find a synodic rotation period of 7.004±0.036 h. The visual absolute magnitude derived from the SOAR data is Hv = 7.03 ± 0.10. We model the rings' contribution to the flux, and find that the derived Hv is consistent with the predicted ring system aspect angle. We also revised the Chariklo system albedo (4.2%) and effective radius (119 ± 5 km) from a re-analysis of Herschel and WISE thermal data obtained during 2010 with the correct Hv value. No coma is detected from the SOAR data, nor in previous VLT images acquired in 2007-2008, where the rings' aspect angle was close to zero. The upper limit to the dust production rate is 2.5 kg/s. Figure 3 is available in electronic form at http://www.aanda.org

  14. The Nature and Absolute Hydration Free Energy of the Solvated Electron in Water

    SciTech Connect

    Zhan, Chang-Guo; Dixon, David A.

    2003-05-08

    We report the first first-principles solvation-included electronic structure study to energetically compare a variety of candidate structures of the hydrated electron and to determine its absolute hydration free energy, DGhyd298(e-). The calculated results indicate that both the thermal motion and bulk solvent effects can qualitatively change the relative thermodynamic stability of different structures of the hydrated electron based on a cluster of a given size, and that the most stable structure in solution is not necessarily the most stable one in the gas phase. For a given number of explicitly included solvent water molecules, the most stable structure in solution reveals a unique feature of the chemical nature of the solvated electron in water, i.e. the electron forms two strong electron-hydrogen bonds of the eLHO type with the hydrogen-bonded water cluster and two of the hydrogen-bonds in the neutral water cluster are broken. Based on the most stable structures, the calculated electronic excitation energies are within the observed absorption range of the hydrated electron in water. The absolute hydration free energy of the solvated electron in water has been calculated to be -35.5 kcal/mol by using a reliable computational protocol of first-principles solvation-included electronic structure calculations. This value is in excellent agreement with a recently obtained value of -34.6 kcal/mol.

  15. Characterization of an absolute cryogenic radiometer as a standard detector for radiant-power measurements.

    PubMed

    Datla, R U; Stock, K; Parr, A C; Hoyt, C C; Miller, P J; Foukal, P V

    1992-12-01

    An active cavity radiometer of the electrical substitution type with a cone receiver that operates at 2-4 K has been developed for measuring radiant fluxes in the dynamic range of 20 nW to 100 microW within an uncertainty of +/-1% (2sigmalevel). It is a broadband absolute detector with a flat overall absorption efficiency that is >99% for radiation from the visible to long-wavelength IR. The system is designed based on thermal modeling and experimental measurements of concepts. It has been installed in the cryogenic chamber for low-background infrared radiation calibrations at the National Institute of Standards and Technology (NIST) for testing cryogenic blackbody sources, detectors, and optical components. Its time constant, responsivity, and nonequivalence error have been measured. They are in agreement with design predictions. Radiant power measurements of an amplitude-stabilized He-Ne laser beam with the radiometer and an industry standard photodiode detector, QED-200, have been intercompared and found to be in agreement. The intercomparison ratio of the measurements with the absolute cryogenic radiometer and QED-200 was 1.004 in the 75-100-microW range with an uncertainty of 0.5% (the 3sigma level). PMID:20802586

  16. Absolute measurements of the uranium concentration in thick samples using fission-track detectors

    NASA Astrophysics Data System (ADS)

    Enkelmann, Eva; Jonckheere, Raymond; Ratschbacher, Lothar

    2005-04-01

    We propose an improved equation for calculating the uranium concentration in thick samples based on induced fission-track counts in an external detector that takes into consideration (1) the fission-fragment ranges in the sample and external detector, (2) the etchable track length and (3) the track counting efficiency in the external detector. The values of these parameters have been determined by calculation and experiment and are shown to have a significant effect on the calculated uranium concentrations. The new equation was tested by calculating the uranium concentrations in standard uranium glasses (CN-5; IRMM-540R) and apatite samples (Durango; horse tooth) in which the uranium content was also determined with independent methods (INAA; ENAA; TIMS). The results show that: (1) accurate measurements with the fission-track method are feasible within a broad range of uranium concentrations and (2) uranium determinations based on standards are only accurate if the standard and sample are made of the same material. Because the absolute fission-tack dating method is also based on accurate thermal neutron fluence measurements and similar correction factors for the track registration and counting efficiencies, this study provides a strong endorsement for the fact that absolute fission-track ages are accurate.

  17. Absolutely Continuous Spectrum for the Anderson Model on Trees

    E-print Network

    Fournier, John J.F.

    on the Green Function at an Arbitrary Site . . . . . . . . . 49 3.5 On a recursion relation.2 The nodes in the recurrence relation for the forward Green function. . . . . 32 3.3 Rearrangement of a tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 3 Absolutely Continuous Spectrum for the Anderson Model on Some Tree-like Graphs

  18. Absence of absolutely continuous spectrum for random scattering zippers

    NASA Astrophysics Data System (ADS)

    Boumaza, Hakim; Marin, Laurent

    2015-02-01

    A scattering zipper is a system obtained by concatenation of scattering events with equal even number of incoming and outgoing channels. The associated scattering zipper operator is the unitary analog of Jacobi matrices with matrix entries. For infinite identical events and independent and identically distributed random phases, Lyapunov exponents positivity is proved and yields absence of absolutely continuous spectrum by Kotani's theory.

  19. Urey: to measure the absolute age of Mars

    NASA Technical Reports Server (NTRS)

    Randolph, J. E.; Plescia, J.; Bar-Cohen, Y.; Bartlett, P.; Bickler, D.; Carlson, R.; Carr, G.; Fong, M.; Gronroos, H.; Guske, P. J.; Herring, M.; Javadi, H.; Johnson, D. W.; Larson, T.; Malaviarachchi, K.; Sherrit, S.; Stride, S.; Trebi-Ollennu, A.; Warwick, R.

    2003-01-01

    UREY, a proposed NASA Mars Scout mission will, for the first time, measure the absolute age of an identified igneous rock formation on Mars. By extension to relatively older and younger rock formations dated by remote sensing, these results will enable a new and better understanding of Martian geologic history.

  20. Original Research Quantification of Absolute Fat Mass Using an

    E-print Network

    Southern California, University of

    containing varying mix- tures of fat (adipose) and lean tissues. The samples were imaged using 1.5-mm performed to determine fat mass, and served as the comparison standard. Results: Absolute fat mass values also contains water, carbohydrate, and proteins in addition to fat (triglycerides). An alternative

  1. Measuring absolute infrared spectral radiance with correlated photons: new arrangements

    E-print Network

    Migdall, Alan

    metrologia Measuring absolute infrared spectral radiance with correlated photons: new arrangements radiance using correlated photons are presented. The method has the remarkable feature that it allows be measured using correlated photons [1-4]. That work outlined some of the useful features of the method. One

  2. Absolute Value Inequalities: High School Students' Solutions and Misconceptions

    ERIC Educational Resources Information Center

    Almog, Nava; Ilany, Bat-Sheva

    2012-01-01

    Inequalities are one of the foundational subjects in high school math curricula, but there is a lack of academic research into how students learn certain types of inequalities. This article fills part of the research gap by presenting the findings of a study that examined high school students' methods of approaching absolute value inequalities,…

  3. Mathematical Model for Absolute Magnetic Measuring Systems in Industrial Applications

    NASA Astrophysics Data System (ADS)

    Fügenschuh, Armin; Fügenschuh, Marzena; Ludszuweit, Marina; Mojsic, Aleksandar; Sokó?, Joanna

    2015-09-01

    Scales for measuring systems are either based on incremental or absolute measuring methods. Incremental scales need to initialize a measurement cycle at a reference point. From there, the position is computed by counting increments of a periodic graduation. Absolute methods do not need reference points, since the position can be read directly from the scale. The positions on the complete scales are encoded using two incremental tracks with different graduation. We present a new method for absolute measuring using only one track for position encoding up to micrometre range. Instead of the common perpendicular magnetic areas, we use a pattern of trapezoidal magnetic areas, to store more complex information. For positioning, we use the magnetic field where every position is characterized by a set of values measured by a hall sensor array. We implement a method for reconstruction of absolute positions from the set of unique measured values. We compare two patterns with respect to uniqueness, accuracy, stability and robustness of positioning. We discuss how stability and robustness are influenced by different errors during the measurement in real applications and how those errors can be compensated.

  4. Is There a Rule of Absolute Neutralization in Nupe?

    ERIC Educational Resources Information Center

    Krohn, Robert

    1975-01-01

    A previously prosed rule of absolute neutralization (merging underlying low vowels) is eliminated in an alternative analysis including instead a rule that "breaks" the feature matrix of certain low vowels and redistributes the features of each vowel as a sequence of vowel-like transition plus (a). (Author/RM)

  5. A mathematical biologist's guide to absolute and convective instability.

    PubMed

    Sherratt, Jonathan A; Dagbovie, Ayawoa S; Hilker, Frank M

    2014-01-01

    Mathematical models have been highly successful at reproducing the complex spatiotemporal phenomena seen in many biological systems. However, the ability to numerically simulate such phenomena currently far outstrips detailed mathematical understanding. This paper reviews the theory of absolute and convective instability, which has the potential to redress this inbalance in some cases. In spatiotemporal systems, unstable steady states subdivide into two categories. Those that are absolutely unstable are not relevant in applications except as generators of spatial or spatiotemporal patterns, but convectively unstable steady states can occur as persistent features of solutions. The authors explain the concepts of absolute and convective instability, and also the related concepts of remnant and transient instability. They give examples of their use in explaining qualitative transitions in solution behaviour. They then describe how to distinguish different types of instability, focussing on the relatively new approach of the absolute spectrum. They also discuss the use of the theory for making quantitative predictions on how spatiotemporal solutions change with model parameters. The discussion is illustrated throughout by numerical simulations of a model for river-based predator-prey systems. PMID:24272387

  6. Absolute and convective instabilities of heated coaxial jet flow

    NASA Astrophysics Data System (ADS)

    Balestra, Gioele; Gloor, Michael; Kleiser, Leonhard

    2015-05-01

    This study investigates the inviscid, linear spatio-temporal stability of heated, compressible, and incompressible coaxial jet flows. The influence of the temperature ratio and the velocity ratio between the core jet and the bypass stream on the transition from convectively to absolutely unstable flows is studied numerically. The investigation shows that for coaxial jets, absolute instability can occur for considerably lower core-stream temperatures than for single jets. The reason for this modified stability character is the appearance of an additional unstable mode as a result of the outer velocity shear layer between the bypass stream and the ambient flow. The presence of two shear layers enables the interaction between otherwise free waves to give rise to new instabilities. When the bypass-stream velocity is increased, the classical absolute mode known from single jets (inner mode) is first stabilized and then destabilized for high bypass-stream velocities, whereas the outer mode reaches maximum spatio-temporal growth rates when the core-stream velocity is approximately equal to twice the bypass-stream velocity. Additionally, it is demonstrated that the spatio-temporal character of the modes is very sensitive to the shear-layer thickness and to the distance separating the two layers. Increasing the Mach number strongly dampens the onset of an absolute instability for both modes.

  7. ON THE PRESERVATION OF ABSOLUTELY CONTINUOUS SPECTRUM FOR SCHR

    E-print Network

    Denissov, Serguei

    ON THE PRESERVATION OF ABSOLUTELY CONTINUOUS SPECTRUM FOR SCHR  ODINGER OPERATORS SERGEY A;cation: 35P25, 47A40. 1 #12; 2 SERGEY A. DENISOV denote by J p the standard Schatten-von Neumann class remarks, to B. Si- mon and T. Spencer for useful discussions, and to K. Makarov and A. Laptev for giving

  8. Series that Converge Absolutely but Don't Converge

    ERIC Educational Resources Information Center

    Kantrowitz, Robert; Schramm, Michael

    2012-01-01

    If a series of real numbers converges absolutely, then it converges. The usual proof requires completeness in the form of the Cauchy criterion. Failing completeness, the result is false. We provide examples of rational series that illustrate this point. The Cantor set appears in connection with one of the examples.

  9. Absolute calibration of Landsat instruments using the moon.

    USGS Publications Warehouse

    Kieffer, H.H.; Wildey, R.L.

    1985-01-01

    A lunar observation by Landsat could provide improved radiometric and geometric calibration of both the Thematic Mapper and the Multispectral Scanner in terms of absolute radiometry, determination of the modulation transfer function, and sensitivity to scattered light. A pitch of the spacecraft would be required. -Authors

  10. Simple and inexpensive teaching apparatus for absolute measurement of voltage

    NASA Astrophysics Data System (ADS)

    Fulbright, H. W.

    1993-10-01

    Equipment designed for the absolute measurement of voltage is described, suitable for lecture demonstrations or for student laboratory experiments. Although simple and inexpensive it can give results accurate to 1% or 2%. A key element incorporated is a soft drink can.

  11. Relative versus Absolute Stimulus Control in the Temporal Bisection Task

    ERIC Educational Resources Information Center

    de Carvalho, Marilia Pinhiero; Machado, Armando

    2012-01-01

    When subjects learn to associate two sample durations with two comparison keys, do they learn to associate the keys with the short and long samples (relational hypothesis), or with the specific sample durations (absolute hypothesis)? We exposed 16 pigeons to an ABA design in which phases A and B corresponded to tasks using samples of 1 s and 4 s,…

  12. Absolute Calibration of the Small Black Spider Antenna

    E-print Network

    Erdmann, Martin

    Absolute Calibration of the Small Black Spider Antenna for the Pierre Auger Observatory von Oliver Spider LPDA 37 6.1 Logarithmic Periodic Dipole Antennas . . . . . . . . . . . . . . . . . 37 6.2 Properties of the Small Black Spider LPDA . . . . . . . . . . . . . . 39 6.3 Cross Talk between Antenna

  13. Measuring Absolute Gravity on Top of Terry Peak, SD

    USGS Multimedia Gallery

    USGS researchers made microgravity measurements to determine groundwater-storage changes in the karstic Madison aquifer in the Black Hills of South Dakota during 2009-12. The absolute-gravity measurement was made at a station located on top of Terry Peak in the northern Black Hills....

  14. Absolute calibration in the 1750 - 3350 A region

    NASA Technical Reports Server (NTRS)

    Strongylis, G. J.; Bohlin, R. C.

    1977-01-01

    The absolute flux measurements in the rocket ultraviolet made by Bohlin, Frimout, and Lillie (BFL) are revised using a more correct treatment of the air extinction that enters the air calibration of their instrument. The absorption by molecular oxygen and ozone, Rayleigh scattering, and extinction by aerosols is tabulated for general use in ultraviolet calibrations performed in air. The revised absolute flux of eta UMa and final fluxes for alpha Lyr and zeta Oph are presented in the 1750-3350 A region. The absolute flux of the star eta UMa is compared to four other independent determinations in the 1200-3400 A region and a maximum difference of 35% is found near 1500 A between the OAO-2 and Apollo 17 fluxes. The rocket measurements of BFL, the ANS and TD-1 satellite data, and the Apollo 17 data are compared to the ultraviolet fluxes from the OAO-2, demonstrating a photometric reproducibility of about + or - 3 percent. Therefore, all four sets of spectrophotometry can be reduced to a common absolute scale.

  15. Absolute radiometric calibration of detectors between 200-600 A

    NASA Technical Reports Server (NTRS)

    Saloman, E. B.; Ederer, D. L.

    1975-01-01

    A description is given of the experimental methods used in the calibration procedure, taking into account the source of radiant energy, the monochromator, the absolute standard detector, and the transfer standards. The experimental apparatus is discussed. A graph showing the effect of beam motion on the detected signal is presented and a block diagram of the calibration electronic system is provided.

  16. Individual Differences in Absolute and Relative Metacomprehension Accuracy

    ERIC Educational Resources Information Center

    Maki, Ruth H.; Shields, Micheal; Wheeler, Amanda Easton; Zacchilli, Tammy Lowery

    2005-01-01

    The authors investigated absolute and relative metacomprehension accuracy as a function of verbal ability in college students. Students read hard texts, revised texts, or a mixed set of texts. They then predicted their performance, took a multiple-choice test on the texts, and made posttest judgments about their performance. With hard texts,…

  17. Four Years of Absolute Gravity in the Taiwan Orogen (AGTO)

    NASA Astrophysics Data System (ADS)

    Mouyen, Maxime; Masson, Frédéric; Hwang, Cheinway; Cheng, Ching-Chung; Le Moigne, Nicolas; Lee, Chiung-Wu; Kao, Ricky; Hsieh, Nicky

    2010-05-01

    AGTO is a scientific project between Taiwanese and French institutes, which aim is to improve tectonic knowledge of Taiwan primarily using absolute gravity measurements and permanent GPS stations. Both tools are indeed useful to study vertical movements and mass transfers involved in mountain building, a major process in Taiwan located at the convergent margin between Philippine Sea plate and Eurasian plate. This convergence results in two subductions north and south of Taiwan (Ryukyu and Manilla trenches, respectively), while the center is experiencing collision. These processes make Taiwan very active tectonically, as illustrated by numerous large earthquakes and rapid uplift of the Central Range. High slopes of Taiwan mountains and heavy rains brought by typhoons together lead to high landslides and mudflows risks. Practically, absolute gravity measurements have been yearly repeated since 2006 along a transect across south Taiwan, from Penghu to Lutao islands, using FG5 absolute gravimeters. This transect contains ten sites for absolute measurements and has been densified in 2008 by incorporating 45 sites for relative gravity measurements with CG5 gravimeters. The last relative and absolute measurements have been performed in November 2009. Most of the absolute sites have been measured with a good accuracy, about 1 or 2 ?Gal. Only the site located in Tainan University has higher standard deviation, due to the city noise. We note that absolute gravity changes seem to follow a trend in every site. However, straightforward tectonic interpretation of these trends is not valuable as many non-tectonic effects are supposed to change g with time, like groundwater or erosion. Estimating and removing these effects leads to a tectonic gravity signal, which has theoretically two origins : deep mass transfers around the site and vertical movements of the station. The latter can be well constrained by permanent GPS stations located close to the measurement pillar. Deep mass transfers, on the contrary, must be evaluated by modelling. Relative gravity, despite lower accuracy, enable us to cover wider area (about 10 000 km2). Our interest is thus to merge both types of measurements to have a large overview of temporal g changes in the south of Taiwan.

  18. The Orbital and Absolute Magnitude Distributions of Main Belt Asteroids

    E-print Network

    R. Jedicke; T. S. Metcalfe

    1998-03-16

    We have developed a model-independent analytical method for debiasing the four-dimensional (a,e,i,H) distribution obtained in any asteroid observation program and have applied the technique to results obtained with the 0.9m Spacewatch Telescope. From 1992 to 1995 Spacewatch observed ~3740 deg^2 near the ecliptic and made observations of more than 60,000 asteroids to a limiting magnitude of V~21. The debiased semi-major axis and inclination distributions of Main Belt asteroids in this sample with 11.5<= H <16 match the distributions of the known asteroids with H <11.5. The absolute magnitude distribution was studied in the range 8< H <17.5. We have found that the set of known asteroids is complete to about absolute magnitudes 12.75, 12.25 and 11.25 in the inner, middle and outer regions of the belt respectively. The number distribution as a function of absolute magnitude cannot be represented by a single power-law (10^{alpha H}) in any region. We were able to define broad ranges in H in each part of the belt where alpha was nearly constant. Within these ranges of H the slope does not correspond to the value of 0.5 expected for an equilibrium cascade in self-similar collisions (Dohnanyi, 1971). The value of alpha varies with absolute magnitude and shows a `kink' in all regions of the belt for H~13. This absolute magnitude corresponds to a diameter ranging from about 8.5 to 12.5 km depending on the albedo or region of the belt.

  19. The Orbital and Absolute Magnitude Distributions of Main Belt Asteroids

    NASA Astrophysics Data System (ADS)

    Jedicke, R.; Metcalfe, T. S.

    1998-02-01

    We have developed a model-independent analytical method for debiasing the four-dimensional (a,e,i,H) distribution obtained in any asteroid observation program and have applied the technique to results obtained with the 0.9 m Spacewatch telescope. From 1992 to 1995 Spacewatch observed ?3740 deg2near the ecliptic and made observations of more than 60,000 asteroids to a limiting magnitude of V ? 21. The debiased semimajor axis and inclination distributions of main belt asteroids in this sample with 11.5 ?H< 16 match the distributions of the known asteroids withH< 11.5. The absolute magnitude distribution was studied in the range 8 absolute magnitudes 12.75, 12.25, and 11.25 in the inner, middle, and outer regions of the belt, respectively. The number distribution as a function of absolute magnitude cannot be represented by a single power law (10?H) in any region. We were able to define broad ranges inHin each part of the belt where ? was nearly constant. Within these ranges ofHthe slope does not correspond to the value of 0.5 expected for an equilibrium cascade in self-similar collisions (Dohnanyi 1971). The value of ? varies with absolute magnitude and shows a "kink" in all regions of the belt forH? 13. This absolute magnitude corresponds to a diameter ranging from about 8.5 to 12.5 km depending on the albedo or region of the belt.

  20. Absolute Gravity Datum in the Age of Cold Atom Gravimeters

    NASA Astrophysics Data System (ADS)

    Childers, V. A.; Eckl, M. C.

    2014-12-01

    The international gravity datum is defined today by the International Gravity Standardization Net of 1971 (IGSN-71). The data supporting this network was measured in the 1950s and 60s using pendulum and spring-based gravimeter ties (plus some new ballistic absolute meters) to replace the prior protocol of referencing all gravity values to the earlier Potsdam value. Since this time, gravimeter technology has advanced significantly with the development and refinement of the FG-5 (the current standard of the industry) and again with the soon-to-be-available cold atom interferometric absolute gravimeters. This latest development is anticipated to provide improvement in the range of two orders of magnitude as compared to the measurement accuracy of technology utilized to develop ISGN-71. In this presentation, we will explore how the IGSN-71 might best be "modernized" given today's requirements and available instruments and resources. The National Geodetic Survey (NGS), along with other relevant US Government agencies, is concerned about establishing gravity control to establish and maintain high order geodetic networks as part of the nation's essential infrastructure. The need to modernize the nation's geodetic infrastructure was highlighted in "Precise Geodetic Infrastructure, National Requirements for a Shared Resource" National Academy of Science, 2010. The NGS mission, as dictated by Congress, is to establish and maintain the National Spatial Reference System, which includes gravity measurements. Absolute gravimeters measure the total gravity field directly and do not involve ties to other measurements. Periodic "intercomparisons" of multiple absolute gravimeters at reference gravity sites are used to constrain the behavior of the instruments to ensure that each would yield reasonably similar measurements of the same location (i.e. yield a sufficiently consistent datum when measured in disparate locales). New atomic interferometric gravimeters promise a significant increase in accuracy. Our presentation will also explore the impact of such an instrument on our theory of how to constrain the gravity datum and on how to ensure stability, repeatability, and reproducibility across different absolute gravimeter systems.

  1. Absolute wind measurements in the lower thermosphere of Venus using infrared heterodyne spectroscopy

    NASA Technical Reports Server (NTRS)

    Goldstein, Jeffrey J.

    1990-01-01

    The first absolute wind velocities above the Venusian cloud-tops were obtained using NASA/Goddard infrared heterodyne spectrometers at the NASA Infrared Telescope Facility (IRTF) and the McMath Solar Telescope. Beam-integrated Doppler displacements in the non-thermal emission core of (12)C(16)O2 10.33 micron R(8) sampled the line of sight projection of the lower thermospheric wind field (100 to 120 km). A field-usable Lamb-dip laser stabilization system, developed for spectrometer absolute frequency calibration to less than + or - 0.1 MHz, allowed S/N-limited line of sight velocity resolution at the 1 m/s level. The spectrometer's diffraction-limited beam (1.7 arc-second HPBW at McMath, 0.9 arc-second HPBW at IRTF), and 1 to 2 arc-second seeing, provided the spatial resolution necessary for circulation model discrimination. Qualitative analysis of beam-integrated winds provided definitive evidence of a dominant subsolar-antisolar circulation in the lower thermosphere. Beam-integrated winds were modelled with a 100x100 grid over the beam, incorporating beam spatial rolloff and across-the-beam gradients in non-thermal emission intensity, line of sight projection geometry, and horizontal wind velocity. Horizontal wind velocity was derived from a 2-parameter model wind field comprised of subsolar-antisolar and zonal components. Best-fit models indicated a dominant subsolar-antisolar flow with 120 m/s cross-terminator winds and a retrograde zonal component with a 25 m/s equatorial velocity. A review of all dynamical indicators above the cloud-tops allowed development of an integrated and self-consistent picture of circulation in the 70 to 200 km range.

  2. Establishing Ion Ratio Thresholds Based on Absolute Peak Area for Absolute Protein Quantification using Protein Cleavage Isotope Dilution Mass Spectrometry

    PubMed Central

    Loziuk, Philip L.; Sederoff, Ronald R.; Chiang, Vincent L.; Muddiman, David C.

    2014-01-01

    Quantitative mass spectrometry has become central to the field of proteomics and metabolomics. Selected reaction monitoring is a widely used method for the absolute quantification of proteins and metabolites. This method renders high specificity using several product ions measured simultaneously. With growing interest in quantification of molecular species in complex biological samples, confident identification and quantitation has been of particular concern. A method to confirm purity or contamination of product ion spectra has become necessary for achieving accurate and precise quantification. Ion abundance ratio assessments were introduced to alleviate some of these issues. Ion abundance ratios are based on the consistent relative abundance (RA) of specific product ions with respect to the total abundance of all product ions. To date, no standardized method of implementing ion abundance ratios has been established. Thresholds by which product ion contamination is confirmed vary widely and are often arbitrary. This study sought to establish criteria by which the relative abundance of product ions can be evaluated in an absolute quantification experiment. These findings suggest that evaluation of the absolute ion abundance for any given transition is necessary in order to effectively implement RA thresholds. Overall, the variation of the RA value was observed to be relatively constant beyond an absolute threshold ion abundance. Finally, these RA values were observed to fluctuate significantly over a 3 year period, suggesting that these values should be assessed as close as possible to the time at which data is collected for quantification. PMID:25154770

  3. Nanoscale Thermoelectrics: A Study of the Absolute Seebeck Coefficient of Thin Films

    NASA Astrophysics Data System (ADS)

    Mason, Sarah J.

    The worlds demand for energy is ever increasing. Likewise, the environmental impact of climate change due generating that energy through combustion of fossil fuels is increasingly alarming. Due to these factors new sources of renewable energies are constantly being sought out. Thermoelectric devices have the ability to generate clean, renewable, energy out of waste heat. However promising that is, their inefficiency severely inhibits applicability and practical use. The usefulness of a thermoelectric material increases with the dimensionless quantity, ZT, which depends on the Seebeck coefficient and electrical and thermal conductivity. These characteristic material parameters have interdependent energy transport contributions that classically prohibit the optimization of one with out the detriment of another. Encouraging advancements of ZT have occurred in the past ten years due to the decoupling of the thermal and electrical conductivity. Further advancements are necessary in order to produce applicable devices. One auspicious way of decoupling or tuning energy transport properties, is through size reduction to the nanoscale. However, with reduced dimensions come complications in measuring material properties. Measurements of properties such as the Seebeck coefficient, S, are primarily contingent upon the measurement apparatus. The Seebeck coefficient is defined as the amount of voltage generated by a thermal gradient. Measuring a thermally generated voltage by traditional methods gives, the voltage measured as a linear function of the Seebeck coefficient of the leads and of the material being tested divided by the applied thermal gradient. If accurate values of the Seebeck coefficients of the leads are available, simple subtraction provides the answer. This is rarely the case in nanoscale measurement devices with leads exclusively made from thin film materials that do not have well known bulk-like thermopower values. We have developed a technique to directly measure, S, as a function of temperature using a micro-machined thermal isolation platform consisting of a suspended, patterned SiN membrane. By measuring a series of thicknesses of metallic films up to the infinitely thin film limit, in which the electrical resistivity is no longer decreasing with increasing film thickness, but still not at bulk values, along with the effective electron mean free path, we are able to show the contribution of the leads needed to measure this property. Having a comprehensive understanding of the background contribution we are able to determine the absolute Seebeck coefficient of a wide variety of thin films. The nature of the design of the SiN membrane also allows the ability to accurately and directly measure thermal and electrical transport of the thin films yielding a comprehensive measurement of the three quantities that characterize a material's efficiency. This can serve to further the development of thermoelectric materials through precise measurements of the material properties that dictate efficiency.

  4. Calculating effective absolute permeability in sandstone/shale sequences

    SciTech Connect

    Deutsch, C. )

    1989-09-01

    In this paper two averaging algorithms are proposed for determining block effective absolute permeability. The experimental relationship between the effective permeability, the volume fraction of shale, and the anisotropy of the shales is first observed through repeated flow simulations. A power-averaging model and a percolation model are proposed to fit the experimentally observed relationship. The power-averaging model provides a surprisingly easy and efficient way to calculate block effective absolute permeability. A simple graph is given to determine the averaging power from the geometric anisotropy (aspect ratio) of the shales for both vertical and horizontal steady-state flow. A correction for large shales relative to small gridblocks is also proposed.

  5. An S-band radiometer design with high absolute precision

    NASA Technical Reports Server (NTRS)

    Hardy, W. N.; Gray, K. W.; Love, A. W.

    1974-01-01

    A radiometer for the remote measurement of sea surface temperature is described. The development of an instrument capable not only of high relative accuracy (i.e., resolution) but also of high absolute precision is considered. The concepts underlying the design of an instrument capable of an absolute accuracy of a few tenths degrees Kelvin in the measurement of brightness temperature at S band are described. The role of the antenna is discussed, and the importance of high ohmic and beam efficiencies is stressed. The hardware itself is fully described, along with an outline concerning the design of a unique cryogenically cooled termination used to calibrate the whole radiometer, including antenna. Finally, some test results are presented that show that the design goals for the instrument have been closely approached.

  6. Absolute measurement of square flats with Legendre polynomial fitting method

    NASA Astrophysics Data System (ADS)

    Gao, Bo; Li, Qiang; He, Yuhang; Chai, Liqun; Wei, Xiaohong

    2014-12-01

    Zernike Polynomial fitting method is an effective way to reconstruct absolute surface for three-flat test. However, the Zernike circle polynomials are not orthogonal over the circular area, hence they are not suitable for square flat. We present an absolute testing of a square flat with Legendre polynomial fitting method, which relies on calculating the coefficients of the Legendre terms by least-square fitting method. To obtain the three-dimensional surface data, one additional measurement that rotate the test flat through 90° should be introduced. The formulas are derived theoretically in detail, and validity has been proved by simulated experiment. Vertical profiles of the three surfaces are compared with the measurement results obtained by three-flat test. Good agreement validates our method.

  7. Absolute magnitude calibration using trigonometric parallax - Incomplete, spectroscopic samples

    NASA Technical Reports Server (NTRS)

    Ratnatunga, Kavan U.; Casertano, Stefano

    1991-01-01

    A new numerical algorithm is used to calibrate the absolute magnitude of spectroscopically selected stars from their observed trigonometric parallax. This procedure, based on maximum-likelihood estimation, can retrieve unbiased estimates of the intrinsic absolute magnitude and its dispersion even from incomplete samples suffering from selection biases in apparent magnitude and color. It can also make full use of low accuracy and negative parallaxes and incorporate censorship on reported parallax values. Accurate error estimates are derived for each of the fitted parameters. The algorithm allows an a posteriori check of whether the fitted model gives a good representation of the observations. The procedure is described in general and applied to both real and simulated data.

  8. Self consistent, absolute calibration technique for photon number resolving detectors

    E-print Network

    Avella, A; Degiovanni, I P; Genovese, M; Gramegna, M; Lolli, L; Monticone, E; Portesi, C; Rajteri, M; Rastello, M L; Taralli, E; Traina, P; White, M; 10.1364/OE.19.023249

    2011-01-01

    Well characterized photon number resolving detectors are a requirement for many applications ranging from quantum information and quantum metrology to the foundations of quantum mechanics. This prompts the necessity for reliable calibration techniques at the single photon level. In this paper we propose an innovative absolute calibration technique for photon number resolving detectors, using a pulsed heralded photon source based on parametric down conversion. The technique, being absolute, does not require reference standards and is independent upon the performances of the heralding detector. The method provides the results of quantum efficiency for the heralded detector as a function of detected photon numbers. Furthermore, we prove its validity by performing the calibration of a Transition Edge Sensor based detector, a real photon number resolving detector that has recently demonstrated its effectiveness in various quantum information protocols.

  9. Self consistent, absolute calibration technique for photon number resolving detectors

    E-print Network

    A. Avella; G. Brida; I. P. Degiovanni; M. Genovese; M. Gramegna; L. Lolli; E. Monticone; C. Portesi; M. Rajteri; M. L. Rastello; E. Taralli; P. Traina; M. White

    2011-11-16

    Well characterized photon number resolving detectors are a requirement for many applications ranging from quantum information and quantum metrology to the foundations of quantum mechanics. This prompts the necessity for reliable calibration techniques at the single photon level. In this paper we propose an innovative absolute calibration technique for photon number resolving detectors, using a pulsed heralded photon source based on parametric down conversion. The technique, being absolute, does not require reference standards and is independent upon the performances of the heralding detector. The method provides the results of quantum efficiency for the heralded detector as a function of detected photon numbers. Furthermore, we prove its validity by performing the calibration of a Transition Edge Sensor based detector, a real photon number resolving detector that has recently demonstrated its effectiveness in various quantum information protocols.

  10. Convective and Absolute Instability of Liquid Jets under Gravity Effects

    NASA Astrophysics Data System (ADS)

    Amini, Ghobad; Ihme, Matthias; Dolatabadi, Ali

    2012-11-01

    The break-up of liquid jets is of practical importance for several applications, including liquid-fuel-injection and ink-jet printing. In this work, the effect of gravity on the onset and growth rate of absolute and convective instabilities in liquid jets is studied. The mathematical problem is formulated in terms of quasi-one-dimensional equations, and the linearized stability equations are solved using a first-order perturbation method. An analytic form of the dispersion equation is derived, and the variation of the growth rate is investigated for a range of positive and negative Bond numbers, corresponding to downward-pointing and rising liquid jet. The critical Weber number, demarcating the transition between convective and absolute instability is determined as function of Reynolds and Froude numbers. Model-results for the limiting case of zero gravity are compared with classical results of Chandrasekhar and Leib & Goldstein, confirming the validity of this approach.

  11. Precision goniometer equipped with a 22-bit absolute rotary encoder.

    PubMed

    Xiaowei, Z; Ando, M; Jidong, W

    1998-05-01

    The calibration of a compact precision goniometer equipped with a 22-bit absolute rotary encoder is presented. The goniometer is a modified Huber 410 goniometer: the diffraction angles can be coarsely generated by a stepping-motor-driven worm gear and precisely interpolated by a piezoactuator-driven tangent arm. The angular accuracy of the precision rotary stage was evaluated with an autocollimator. It was shown that the deviation from circularity of the rolling bearing utilized in the precision rotary stage restricts the angular positioning accuracy of the goniometer, and results in an angular accuracy ten times larger than the angular resolution of 0.01 arcsec. The 22-bit encoder was calibrated by an incremental rotary encoder. It became evident that the accuracy of the absolute encoder is approximately 18 bit due to systematic errors. PMID:15263709

  12. Henry More and the development of absolute time.

    PubMed

    Thomas, Emily

    2015-12-01

    This paper explores the nature, development and influence of the first English account of absolute time, put forward in the mid-seventeenth century by the 'Cambridge Platonist' Henry More. Against claims in the literature that More does not have an account of time, this paper sets out More's evolving account and shows that it reveals the lasting influence of Plotinus. Further, this paper argues that More developed his views on time in response to his adoption of Descartes' vortex cosmology and cosmogony, providing new evidence of More's wider project to absorb Cartesian natural philosophy into his Platonic metaphysics. Finally, this paper argues that More should be added to the list of sources that later English thinkers - including Newton and Samuel Clarke - drew on in constructing their absolute accounts of time. PMID:26568082

  13. Absolute Configurations of Zingiberenols Isolated from Ginger (Zingiber officinale) Rhizomes.

    PubMed

    Khrimian, Ashot; Shirali, Shyam; Guzman, Filadelfo

    2015-12-24

    Two stereoisomeric zingiberenols in ginger were identified as (3R,6R,7S)-1,10-bisaboladien-3-ol (2) and (3S,6R,7S)-1,10-bisaboladien-3-ol (5). Absolute configurations were assigned by utilizing 1,10-bisaboladien-3-ol stereoisomers and two gas-chromatography columns: a 25 m Hydrodex-?-6TBDM and 60 m DB-5MS. The C-6 and C-7 absolute configurations in both zingiberenols match those of zingiberene present abundantly in ginger rhizomes. Interestingly, zingiberenol 2 has recently been identified as a male-produced sex pheromone of the rice stink bug, Oebalus poecilus, thus indicating that ginger plants may be a potential source of the sex pheromone of this bug. PMID:26606508

  14. In Self-contradiction, Machian Geocentrism Entails Absolute Space

    E-print Network

    Hartman, Herbert I

    2014-01-01

    Luka Popov has attempted to advance Machian physics by maintaining that the heliocentric system must be replaced by Tycho Brahe's geocentric system. We show that while geocentrism relies on Mach's contention that accelerations are relative, this contention is untenable because, inter alia, the consequences of an acceleration of an object with respect to the fixed stars cannot be duplicated by acceleration of the stars with respect to this object and, if the universe and a co-rotating observer have the same angular velocity, this motion is detectable because they have different linear velocities. Also, geocentrism precludes the relativity of accelerations and leads to an absolute space while Mach argued against absolute space, Popov's result that the force exerted by the Earth on the Sun depends on the square of the Sun's mass but is independent of the Earth's mass is paradoxical, and the annual asymmetry of the Cosmic Microwave Background falsifies all geocentric or 'Tychonic/Brahean) systems.

  15. Absolute phase effects on CPMG-type pulse sequences

    NASA Astrophysics Data System (ADS)

    Mandal, Soumyajit; Oh, Sangwon; Hürlimann, Martin D.

    2015-12-01

    We describe and analyze the effects of transients within radio-frequency (RF) pulses on multiple-pulse NMR measurements such as the well-known Carr-Purcell-Meiboom-Gill (CPMG) sequence. These transients are functions of the absolute RF phases at the beginning and end of the pulse, and are thus affected by the timing of the pulse sequence with respect to the period of the RF waveform. Changes in transients between refocusing pulses in CPMG-type sequences can result in signal decay, persistent oscillations, changes in echo shape, and other effects. We have explored such effects by performing experiments in two different low-frequency NMR systems. The first uses a conventional tuned-and-matched probe circuit, while the second uses an ultra-broadband un-tuned or non-resonant probe circuit. We show that there are distinct differences between the absolute phase effects in these two systems, and present simple models that explain these differences.

  16. Absolute scale-based imaging position encoder with submicron accuracy

    NASA Astrophysics Data System (ADS)

    Anisimov, Andrey G.; Pantyushin, Anton V.; Lashmanov, Oleg U.; Vasilev, A. S.; Timofeev, Alexander N.; Korotaev, Valery V.; Gordeev, Sergey V.

    2013-04-01

    Study is devoted to experimental research and development of absolute imaging position encoder based on standard calibrated scale of invar alloy with 1 mm spacing. The encoder uses designed imaging system as a vernier and absolute magnetic encoder as a rough indication. The features of optical design, choice and use of imaging system as long as indexes images processing algorithm are described. A shadow method was implemented: indexes images on a CCD array are formed by the lens focused at the scale surface; the laser module lights up the scale through a beam-splitting prism by a parallel beam. Further dark indexes images on a light scale background are detected and analyzed to estimate the encoder position. Full range of experimental tests was set to calibrate the encoder and to estimate the accuracy. As a result, accuracy close to 1 ?m at 1 m was achieved.

  17. The importance and attainment of accurate absolute radiometric calibration

    NASA Technical Reports Server (NTRS)

    Slater, P. N.

    1984-01-01

    The importance of accurate absolute radiometric calibration is discussed by reference to the needs of those wishing to validate or use models describing the interaction of electromagnetic radiation with the atmosphere and earth surface features. The in-flight calibration methods used for the Landsat Thematic Mapper (TM) and the Systeme Probatoire d'Observation de la Terre, Haute Resolution visible (SPOT/HRV) systems are described and their limitations discussed. The questionable stability of in-flight absolute calibration methods suggests the use of a radiative transfer program to predict the apparent radiance, at the entrance pupil of the sensor, of a ground site of measured reflectance imaged through a well characterized atmosphere. The uncertainties of such a method are discussed.

  18. Absolute configuration of labdane diterpenoids from Physalis nicandroides.

    PubMed

    Maldonado, Emma; Pérez-Castorena, Ana L; Romero, Yunuen; Martínez, Mahinda

    2015-02-27

    A mixture of the new epimeric labdenetriols 1 and 2 was isolated from the aerial parts of Physalis nicandroides. The structures of 1 and 2, including their absolute configurations, were established by analyses of their spectroscopic data, together with the X-ray diffraction analysis of acetonide 3 and chemical correlation with (-)-(13E)-labd-13-ene-8?,15-diol (6), whose absolute configuration was also confirmed by X-ray analysis of its dibromo derivative 7. The epimeric labdenediols 8 and 9, the known labdanes 6 and 11, and the acylsucroses 12 and 13 were also isolated. Labdanes 6 and 11 showed moderate anti-inflammatory activities in the induced ear edema model. PMID:25634541

  19. In-flight absolute radiometric calibration of the thematic mapper

    NASA Technical Reports Server (NTRS)

    Castle, K. R.; Holm, R. G.; Kastner, C. J.; Palmer, J. M.; Slater, P. N.; Dinguirard, M.; Ezra, C. E.; Jackson, R. D.; Savage, R. K.

    1984-01-01

    In order to determine temporal changes of the absolute radiometric calibration of the entire TM system in flight spectroradiometric measurements of the ground and the atmosphere were made simultaneously with TM image collections over the White Sands, New Mexico area. By entering the measured values in an atmospheric radiative transfer program, the radiance levels in four of the spectral bands of the TM were determined, band 1:0.45 to 0.52 micrometers, band 2:0.53 to 0.61 micrometers band 3:0.62 to 0.70 micrometers and 4:0.78 to 0.91 micrometers. These levels were compared to the output digital counts from the detectors that sampled the radiometrically measured ground area, thus providing an absolute radiometric calibration of the entire TM system utilizing those detectors.

  20. Validation of GOCE by absolute and relative gravimetry

    NASA Astrophysics Data System (ADS)

    Pettersen, B. R.; Sprlak, M.; Lysaker, D. I.; Omang, O. C. D.; Sekowski, M.; Dykowski, P.

    2012-04-01

    Absolute gravimetry has been performed in 2011 by FG5 and A10 instruments in selected sites of the Norwegian first order gravity network. These observations are used as reference values to transform a large number of relative gravity values collected in 1968-1972. The outcome is a database at current epoch in a reference frame defined by the absolute gravity values. This constitutes our test field for validation of GOCE results. In the test fields, validation of GOCE-derived gravity anomalies was performed. The spectral enhancement method was applied to avoid the spectral inconsistency between the terrestrial and the satellite data. For this purpose, contributions of the EGM2008 model and a gravitational effect of a residual terrain model were calculated.

  1. Absolute Bunch Length Measurements by Incoherent Radiation Fluctuation Analysis

    SciTech Connect

    Sannibale, F.; Stupakov, G.V.; Zolotorev, M.S.; Filippetto, D.; Jagerhofer, L.; /Vienna, Tech. U.

    2009-12-09

    By analyzing the pulse to pulse intensity fluctuations of the radiation emitted by a charge particle in the incoherent part of the spectrum, it is possible to extract information about the spatial distribution of the beam. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory, we have developed and successfully tested a simple scheme based on this principle that allows for the absolute measurement of the rms bunch length. A description of the method and the experimental results are presented.

  2. Absolute bunch length measurements by incoherent radiation fluctuation analysis

    SciTech Connect

    Sannibale, Fernando; Stupakov, Gennady; Zolotorev, Max; Filippetto, Daniele; Jagerhofer, Lukas

    2008-09-29

    By analyzing the pulse to pulse intensity fluctuations of the radiation emitted by a charge particle in the incoherent part of the spectrum, it is possible to extract information about the spatial distribution of the beam. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory, we have developed and successfully tested a simple scheme based on this principle that allows for the absolute measurement of the rms bunch length. A description of the method and the experimental results are presented.

  3. Absolute-gravity stations in Western Dronning Maud Land, Antarctica

    NASA Astrophysics Data System (ADS)

    Mäkinen, Jaakko; Rasindra, Ravik; Chand, Uttam; Tiwari, Virendra; Lukin, Valery; Anisimov, Michail; Melvaer, Yngve; Melland, Gudmund; Koivula, Hannu; Näränen, Jyri; Poutanen, Markku

    2013-04-01

    Absolute-gravity stations are an important part of the geodetic infrastructure of the Antarctic. They provide accurate starting values for gravity surveys performed e.g. for the determination of the geoid, for geological studies and for geophysical investigations. The time variation in gravity determined from repeated absolute-gravity measurements provides insights into the Glacial Isostatic Adjustment (GIA) and into solid Earth deformation due to variation in contemporary ice load. Given sufficient joint coverage with International Terrestrial Reference Frame (ITRF) sites, gravity rates in high latitudes could in principle provide an independent check of the geocentricity of the z-dot (velocities in the direction of the rotation axis of the Earth) of the ITRF. We review the absolute gravity stations in Western and Central Dronning Maud Land. The oldest station is at the Finnish base Aboa, with 5 measurements by the Finnish Geodetic Institute (FGI) starting with the FINNARP 1993 expedition. Measurements at Maitri (India) and Novolazarevskaya (Russia) were first performed in 2004 by the National Geophysical Research Institute (NGRI) of India, and by the FGI, respectively. In the season 2010/11 a new station was constructed at Troll (Norway). In the season 2011/12 the aforementioned four sites were occupied by the FG5-221 absolute gravimeter of the FGI. At Sanae IV (South Africa) there are previous occupations by the FG5-221, in 2003/4 and 2005/6. All these bases have continuous GNSS stations. Numerous supporting measurements have been made at the sites: microgravity networks, levelling and GNSS ties to excentres etc., for controlling the stability of the stations. At some sites, nearby glacier elevations were surveyed to monitor the attraction of the variable close-field snow and ice masses. We give a description of the sites and the measurements performed at them. The work has benefited from the co-operation in the COST Action ES0701 "Improved Constraints on Models of GIA".

  4. On the Absolutely Continuous Spectrum of Stark Operators

    NASA Astrophysics Data System (ADS)

    Perelman, Galina

    The stability of the absolutely continuous spectrum of the one-dimensional Stark operator under perturbations of the potential is discussed. The focus is on proving this stability under minimal assumptions on smoothness of the perturbation. A general criterion is presented together with some applications. These include the case of periodic perturbations where we show that any perturbation vL1()?H-1/2() preserves the a.c. spectrum.

  5. Measuring absolute spectral radiance using an Erbium Doped Fibre Amplifier

    E-print Network

    Sanguinetti, Bruno; Monteiro, Fernando; Gisin, Nicolas; Zbinden, Hugo

    2012-01-01

    We describe a method to measure the spectral radiance of a source in an absolute way without the need of a reference. Here we give the necessary detail to allow for the device to be reproduced from standard fiber-optic components. The device is suited for fiber-optic applications at telecom wavelengths and calibration of powermeters and spectrometers at light levels from 1nW to 1uW.

  6. Measuring absolute spectral radiance using an Erbium Doped Fibre Amplifier

    E-print Network

    Bruno Sanguinetti; Thiago Guerreiro; Fernando Monteiro; Nicolas Gisin; Hugo Zbinden

    2012-10-22

    We describe a method to measure the spectral radiance of a source in an absolute way without the need of a reference. Here we give the necessary detail to allow for the device to be reproduced from standard fiber-optic components. The device is suited for fiber-optic applications at telecom wavelengths and calibration of powermeters and spectrometers at light levels from 1nW to 1uW.

  7. Absolute Source Activity Measurement with a Single Detector

    SciTech Connect

    Bikit, I.; Nemes, T.; Mrdja, D.; Forkapic, S.

    2009-08-26

    In the present paper the activity of {sup 60}Co source was measured using the full absorption, sum and random coincidences (pile up) peaks and the total spectrum area in the gamma spectra. By the exact treatment of the chance coincidence and pile-up events, surprisingly good results were obtained. With the source on the detector end-cap (when the angular correlation effects are negligible), this simple method yields absolute activity values deviating from the reference activity for about 1 percent.

  8. Absolute intensity of radiation emitted by uranium plasmas

    NASA Technical Reports Server (NTRS)

    Jalufka, N. W.; Lee, J. H.; Mcfarland, D. R.

    1975-01-01

    The absolute intensity of radiation emitted by fissioning and nonfissioning uranium plasmas in the spectral range from 350 nm to 1000 nm was measured. The plasma was produced in a plasma-focus apparatus and the plasma properties are simular to those anticipated for plasma-core nuclear reactors. The results are expected to contribute to the establishment of design criteria for the development of plasma-core reactors.

  9. Experimental evidence of absolute and convective instabilities in optics.

    PubMed

    Louvergneaux, Eric; Szwaj, Christophe; Agez, Gonzague; Glorieux, Pierre; Taki, Majid

    2004-01-30

    Experimental evidence of convective and absolute instabilities in a nonlinear optical system is given. In optics, the presence of spatial nonuniformities brings in additional complexity. Hence, signatures characterizing these two regimes are derived based on analytical and numerical investigations. The corresponding noise-sustained and dynamical patterns are observed experimentally in a liquid crystal layer subjected to a laser beam with tilted feedback. PMID:14995373

  10. Synthesis and absolute configuration of hormone alpha1.

    PubMed

    Yajima, Arata; Qin, Yong; Zhou, Xuan; Kawanishi, Naoki; Xiao, Xue; Wang, Jue; Zhang, Dan; Wu, Yi; Nukada, Tomoo; Yabuta, Goro; Qi, Jianhua; Asano, Tomoyo; Sakagami, Youji

    2008-04-01

    An important biological event in phytopathogens of the genus Phytophthora is sexual reproduction, which is conducted by two mating types, A1 and A2. A factor known as hormone alpha1 is secreted by the A1 mating type and induces the formation of sexual spores (oospores) in the A2 mating type. Here we describe the asymmetric synthesis and assignment of the absolute configuration of hormone alpha1 by oospore-inducing assays of the synthesized isomers. PMID:18297064

  11. Synthesis and Determination of Absolute Configuration of Lentztrehalose A.

    PubMed

    Zhang, Ming; Wada, Shun-Ichi; Amemiya, Fuyuki; Watanabe, Takumi; Shibasaki, Masakatsu

    2015-01-01

    The synthesis of lentztrehalose A, a naturally occurring trehalose derivative exhibiting various biological activities including autophagy-inducing activity, was achieved. The synthesis commenced with the selective protection of hydroxyl groups of commercially available trehalose, followed by the introduction of the side chain moiety by two methods: 1) prenylation and successive diastereoselective dihydroxylation; or 2) etherification by opening of the chiral epoxide. The present synthetic study clarified the unreported absolute configuration of the secondary alcohol part in the side chain portion. PMID:26521862

  12. On the Absolute Continuity of the Blackwell Measure

    NASA Astrophysics Data System (ADS)

    Bárány, Balázs; Kolossváry, István

    2015-04-01

    In 1957, Blackwell expressed the entropy of hidden Markov chains using a measure which can be characterised as an invariant measure for an iterated function system with place-dependent weights. This measure, called the Blackwell measure, plays a central role in understanding the entropy rate and other important characteristics of fundamental models in information theory. We show that for a suitable set of parameter values the Blackwell measure is absolutely continuous for almost every parameter in the case of binary symmetric channels.

  13. THE ABSOLUTE MAGNITUDES OF TYPE Ia SUPERNOVAE IN THE ULTRAVIOLET

    SciTech Connect

    Brown, Peter J.; Roming, Peter W. A.; Ciardullo, Robin; Gronwall, Caryl; Hoversten, Erik A.; Pritchard, Tyler; Milne, Peter; Bufano, Filomena; Mazzali, Paolo; Elias-Rosa, Nancy; Filippenko, Alexei V.; Li Weidong; Foley, Ryan J.; Hicken, Malcolm; Kirshner, Robert P.; Gehrels, Neil; Holland, Stephen T.; Immler, Stefan; Phillips, Mark M.; Still, Martin

    2010-10-01

    We examine the absolute magnitudes and light-curve shapes of 14 nearby (redshift z = 0.004-0.027) Type Ia supernovae (SNe Ia) observed in the ultraviolet (UV) with the Swift Ultraviolet/Optical Telescope. Colors and absolute magnitudes are calculated using both a standard Milky Way extinction law and one for the Large Magellanic Cloud that has been modified by circumstellar scattering. We find very different behavior in the near-UV filters (uvw1{sub rc} covering {approx}2600-3300 A after removing optical light, and u {approx} 3000-4000 A) compared to a mid-UV filter (uvm2 {approx}2000-2400 A). The uvw1{sub rc} - b colors show a scatter of {approx}0.3 mag while uvm2-b scatters by nearly 0.9 mag. Similarly, while the scatter in colors between neighboring filters is small in the optical and somewhat larger in the near-UV, the large scatter in the uvm2 - uvw1 colors implies significantly larger spectral variability below 2600 A. We find that in the near-UV the absolute magnitudes at peak brightness of normal SNe Ia in our sample are correlated with the optical decay rate with a scatter of 0.4 mag, comparable to that found for the optical in our sample. However, in the mid-UV the scatter is larger, {approx}1 mag, possibly indicating differences in metallicity. We find no strong correlation between either the UV light-curve shapes or the UV colors and the UV absolute magnitudes. With larger samples, the UV luminosity might be useful as an additional constraint to help determine distance, extinction, and metallicity in order to improve the utility of SNe Ia as standardized candles.

  14. New Ultra-High Sensitivity, Absolute, Linear, and Rotary Encoders

    NASA Technical Reports Server (NTRS)

    Leviton, Douglas B.

    1998-01-01

    Several new types of absolute optical encoders of both rotary and linear function are discussed. The means for encoding are complete departures from conventional optical encoders and offer advantages of compact form, immunity to damage-induced dropouts of position information, and about an order of magnitude higher sensitivity over what is commercially available. Rotary versions have sensitivity from 0.02 arcseconds down to 0.003 arcsecond while linear models have sensitivity of 10 nm.

  15. The Orbital and Absolute Magnitude Distributions of Main Belt Asteroids

    E-print Network

    Jedicke, R

    1998-01-01

    We have developed a model-independent analytical method for debiasing the four-dimensional (a,e,i,H) distribution obtained in any asteroid observation program and have applied the technique to results obtained with the 0.9m Spacewatch Telescope. From 1992 to 1995 Spacewatch observed ~3740 deg^2 near the ecliptic and made observations of more than 60,000 asteroids to a limiting magnitude of V~21. The debiased semi-major axis and inclination distributions of Main Belt asteroids in this sample with 11.5<= H <16 match the distributions of the known asteroids with H <11.5. The absolute magnitude distribution was studied in the range 8< H <17.5. We have found that the set of known asteroids is complete to about absolute magnitudes 12.75, 12.25 and 11.25 in the inner, middle and outer regions of the belt respectively. The number distribution as a function of absolute magnitude cannot be represented by a single power-law (10^{alpha H}) in any region. We were able to define broad ranges in H in each par...

  16. The Absolute Magnitudes of Type Ia Supernovae in the Ultraviolet

    E-print Network

    Brown, Peter J; Milne, Peter; Bufano, Filomena; Ciardullo, Robin; Elias-Rosa, Nancy; Filippenko, Alexei V; Foley, Ryan J; Gehrels, Neil; Gronwall, Caryl; Hicken, Malcolm; Holland, Stephen T; Hoversten, Erik A; Immler, Stefan; Kirshner, Robert P; Li, Weidong; Mazzali, Paolo; Phillips, Mark M; Pritchard, Tyler; Still, Martin; Turatto, Massimo; Berk, Daniel Vanden

    2010-01-01

    We examine the absolute magnitudes and light-curve shapes of 14 nearby(redshift z = 0.004--0.027) Type Ia supernovae (SNe~Ia) observed in the ultraviolet (UV) with the Swift Ultraviolet/Optical Telescope. Colors and absolute magnitudes are calculated using both a standard Milky Way (MW) extinction law and one for the Large Magellanic Cloud that has been modified by circumstellar scattering. We find very different behavior in the near-UV filters (uvw1_rc covering ~2600-3300 A after removing optical light, and u ~3000--4000 A) compared to a mid-UV filter (uvm2 ~2000-2400 A). The uvw1_rc-b colors show a scatter of ~0.3 mag while uvm2-b scatters by nearly 0.9 mag. Similarly, while the scatter in colors between neighboring filters is small in the optical and somewhat larger in the near-UV, the large scatter in the uvm2-uvw1 colors implies significantly larger spectral variability below 2600 A. We find that in the near-UV the absolute magnitudes at peak brightness of normal SNe Ia in our sample are correlated with ...

  17. The red clump absolute magnitude based on revised Hipparcos parallaxes

    E-print Network

    M. A. T. Groenewegen

    2008-07-17

    Over the past decade the use of the red clump (RC) as distance indicator has increased in importance as this evolutionary phase is well populated and a good local calibration exists. The absolute calibration of the RC in the $I$ and $K$ band is investigated again based on the recently published revised Hipparcos parallaxes. A numerical model is developed that takes the various selection criteria and the properties of the Hipparcos catalogue into account. The biases involved in applying certain selections are estimated with this model. The absolute magnitudes that are found are $M_{\\rm I} = -0.22 \\pm 0.03$ and $M_{\\rm K} = -1.54 \\pm 0.04$ (on the 2MASS system). The $I$-band value is in good agreement with previous determinations, the $K$-band value is fainter than previously quoted, and this seems to be related to a selection bias whereby accurate $K$-magnitudes are only available for relatively few bright stars. Applying population corrections to the absolute $K$ magnitude of RC stars in clusters supports the fainter magnitude scale.

  18. Overspecification of color, pattern, and size: salience, absoluteness, and consistency

    PubMed Central

    Tarenskeen, Sammie; Broersma, Mirjam; Geurts, Bart

    2015-01-01

    The rates of overspecification of color, pattern, and size are compared, to investigate how salience and absoluteness contribute to the production of overspecification. Color and pattern are absolute and salient attributes, whereas size is relative and less salient. Additionally, a tendency toward consistent responses is assessed. Using a within-participants design, we find similar rates of color and pattern overspecification, which are both higher than the rate of size overspecification. Using a between-participants design, however, we find similar rates of pattern and size overspecification, which are both lower than the rate of color overspecification. This indicates that although many speakers are more likely to include color than pattern (probably because color is more salient), they may also treat pattern like color due to a tendency toward consistency. We find no increase in size overspecification when the salience of size is increased, suggesting that speakers are more likely to include absolute than relative attributes. However, we do find an increase in size overspecification when mentioning the attributes is triggered, which again shows that speakers tend to refer in a consistent manner, and that there are circumstances in which even size overspecification is frequently produced. PMID:26594190

  19. Investigating the absolute phase information in acoustic wave resonance scattering

    PubMed Central

    Mitri, F.G.; Greenleaf, J.F.; Fellah, Z.E.A.; Fatemi, M.

    2014-01-01

    The aim if this work is to investigate the absolute phase information in resonance acoustic scattering by spheres and cylinders and place this work in the broader context of scattering in which the properties of the magnitude and (processed) phase have been examined in a more general way than in the classical Resonance Scattering Theory (RST). Here, comparisons are made between the classical and modified RST formalisms of acoustic resonance scattering. Experimental and theoretical backscattering form functions are obtained and discussed. It is shown that the magnitude and processed (unwrapped) phase can be correctly obtained through the classical RST, suggesting that the modified RST formalism offers little new practical advantage. Furthermore, the absolute phase is shown to be very sensitive to object's resonances, suggesting that the unwrapped phase may be considered as an efficient tool, along with the magnitude information, to carry out remote (active) classification of targets in underwater acoustics applications. The combination of absolute phase information with the magnitude data offers a complementary advantage in the identification of resonances from cylinders and spheres. PMID:18294670

  20. Absolute gravity acceleration measurement in atomic sensor laboratories

    NASA Astrophysics Data System (ADS)

    de Angelis, M.; Greco, F.; Pistorio, A.; Poli, N.; Prevedelli, M.; Saccorotti, G.; Sorrentino, F.; Tino, G. M.

    2012-03-01

    This paper reports the results from the accurate measurement of the acceleration of gravity g taken at two separate premises in the Polo Scientifico of the Florence University (Italy). In these laboratories, two separate experiments aiming at measuring the Newtonian constant and testing the measurement of forces with high spatial resolution are in progress. Both experiments require an independent knowledge on the local value of g. Gravity measurements were conducted using an FG5 absolute gravimeter, and accompanied by seismic recordings for evaluating the noise condition at the site. The absolute accelerations of gravity at the two laboratories are ( 980 492 160.6 ± 4.0) ?Gal and ( 980 492 048.3 ± 3.0) ?Gal for the European Laboratory for Non-Linear Spectroscopy (LENS) and Dipartimento di Fisica e Astronomia, respectively. Other than for the two referenced experiments, the data here presented will serve as a benchmark for any future study requiring an accurate knowledge of the absolute value of the acceleration of gravity in the study region.

  1. Bio-Inspired Stretchable Absolute Pressure Sensor Network.

    PubMed

    Guo, Yue; Li, Yu-Hung; Guo, Zhiqiang; Kim, Kyunglok; Chang, Fu-Kuo; Wang, Shan X

    2016-01-01

    A bio-inspired absolute pressure sensor network has been developed. Absolute pressure sensors, distributed on multiple silicon islands, are connected as a network by stretchable polyimide wires. This sensor network, made on a 4'' wafer, has 77 nodes and can be mounted on various curved surfaces to cover an area up to 0.64 m × 0.64 m, which is 100 times larger than its original size. Due to Micro Electro-Mechanical system (MEMS) surface micromachining technology, ultrathin sensing nodes can be realized with thicknesses of less than 100 µm. Additionally, good linearity and high sensitivity (~14 mV/V/bar) have been achieved. Since the MEMS sensor process has also been well integrated with a flexible polymer substrate process, the entire sensor network can be fabricated in a time-efficient and cost-effective manner. Moreover, an accurate pressure contour can be obtained from the sensor network. Therefore, this absolute pressure sensor network holds significant promise for smart vehicle applications, especially for unmanned aerial vehicles. PMID:26729134

  2. Son preference in Indian families: absolute versus relative wealth effects.

    PubMed

    Gaudin, Sylvestre

    2011-02-01

    The desire for male children is prevalent in India, where son preference has been shown to affect fertility behavior and intrahousehold allocation of resources. Economic theory predicts less gender discrimination in wealthier households, but demographers and sociologists have argued that wealth can exacerbate bias in the Indian context. I argue that these apparently conflicting theories can be reconciled and simultaneously tested if one considers that they are based on two different notions of wealth: one related to resource constraints (absolute wealth), and the other to notions of local status (relative wealth). Using cross-sectional data from the 1998-1999 and 2005-2006 National Family and Health Surveys, I construct measures of absolute and relative wealth by using principal components analysis. A series of statistical models of son preference is estimated by using multilevel methods. Results consistently show that higher absolute wealth is strongly associated with lower son preference, and the effect is 20%-40% stronger when the household's community-specific wealth score is included in the regression. Coefficients on relative wealth are positive and significant although lower in magnitude. Results are robust to using different samples, alternative groupings of households in local areas, different estimation methods, and alternative dependent variables. PMID:21302027

  3. Absolute cross sections for electron scattering from furan

    NASA Astrophysics Data System (ADS)

    Maljkovi?, J. B.; Blanco, F.; ?urík, R.; García, G.; Marinkovi?, B. P.; Milosavljevi?, A. R.

    2012-08-01

    We report results of measurements and calculations of absolute cross sections for electron scattering from furan molecules (C4H4O). The experimental absolute differential cross sections (DCSs) for elastic electron scattering were obtained for the incident energies from 50 eV to 300 eV and for scattering angles from 20° to 110°, by using a crossed electron-target beam setup and the relative flow technique for calibration to the absolute scale. The calculations of the electron interaction cross sections are based on a corrected form of the independent-atom method, known as the screening corrected additivity rule (SCAR) procedure and using an improved quasifree absorption model. The latter calculations also account for rotational excitations in the approximation of a free electric dipole and were used to obtain elastic DCSs as well as total and integral elastic cross sections which are tabulated in the energy range from 10 to 10 000 eV. All SCAR calculated cross sections agree very well with both the present and previously published experimental results. Additionally, calculations based on the first Born approximation were performed to calculate both elastic and vibrationally inelastic DCSs for all the modes of furane, in the energy range from 50 eV to 300 eV. The ratios of the summed vibrational to elastic DCSs are presented and discussed. Finally, the present results for furan are compared with previously published elastic DCSs for the tetrahydrofuran molecule and discussed.

  4. The University of Wisconsin Space Science and Engineering Center Absolute Radiance Interferometer (ARI): Predicted and Demonstrated Radiometric Performance

    NASA Astrophysics Data System (ADS)

    Taylor, J. K.; Revercomb, H. E.; Buijs, H.; Grandmont, F.; Gero, P. J.; Best, F. A.; Tobin, D. C.; Knuteson, R. O.

    2012-12-01

    Spectrally resolved thermal radiances measured from orbit with extremely high absolute accuracy (< 0.1 K, k = 3, brightness temperature at scene temperature) constitute a critical observation for future climate benchmark missions. The challenge in the infrared (IR) sensor development for a climate benchmark measurement mission is to achieve this ultra-high accuracy with a design that can be flight qualified, has long design life, and is reasonably small, simple, and affordable. In this area, our design approach for the Absolute Radiance Interferometer (ARI) made use of components with strong spaceflight heritage (direct analogs with high TRL) combined into a functional package for detailed performance testing. The required simplicity is achievable due to the large differences in the sampling and noise requirements for the benchmark climate measurement from those of the typical remote sensing infrared sounders for weather research or operations. Recent laboratory testing of the Absolute Radiance Interferometer (ARI) has demonstrated the capability to meet the 0.1 K (k = 3) uncertainty requirement on-orbit. A summary of the radiometric performance of the ARI at the University of Wisconsin Space Science and Engineering Center (UW-SSEC) will be presented.

  5. A Absolute Hodge Cohomology with Coefficients The aim of this appendix is to provide a natural interpretation of absolute

    E-print Network

    , the category MHMA(X) of algebraic mixed A­Hodge modules is defined, where A is a field contained in R, and X the comparison results A.1.3, A.1.6 and A.1.7 needed for the iden- tification of the absolute Hodge cohomology with the one given in [B1], § 7 for Tate coefficients (A.2.7). A.1 Algebraic Mixed Hodge Modules In [S2], § 4

  6. A Absolute Hodge Cohomology with Coefficients The aim of this appendix is to provide a natural interpretation of absolute

    E-print Network

    prove the comparison results A.1.3, A.1.6 and A.1.7 needed for the iden- tification of the absolute Algebraic Mixed Hodge Modules In [S2], x 4, the category MHM A(X) of algebraic mixed A-Hodge modules is defined, where A is a field contained in R, and X a separated reduced scheme of finite type over C

  7. A novel technique to monitor thermal discharges using thermal infrared imaging.

    PubMed

    Muthulakshmi, A L; Natesan, Usha; Ferrer, Vincent A; Deepthi, K; Venugopalan, V P; Narasimhan, S V

    2013-09-01

    Coastal temperature is an important indicator of water quality, particularly in regions where delicate ecosystems sensitive to water temperature are present. Remote sensing methods are highly reliable for assessing the thermal dispersion. The plume dispersion from the thermal outfall of the nuclear power plant at Kalpakkam, on the southeast coast of India, was investigated from March to December 2011 using thermal infrared images along with field measurements. The absolute temperature as provided by the thermal infrared (TIR) images is used in the Arc GIS environment for generating a spatial pattern of the plume movement. Good correlation of the temperature measured by the TIR camera with the field data (r(2) = 0.89) make it a reliable method for the thermal monitoring of the power plant effluents. The study portrays that the remote sensing technique provides an effective means of monitoring the thermal distribution pattern in coastal waters. PMID:23839171

  8. Absolute Quantification of Somatic DNA Alterations in Human Cancer - Scott Carter, TCGA Scientific Symposium 2011

    Cancer.gov

    Home News and Events Multimedia Library Videos Absolute Quantification of Somatic DNA Alterations in Human Cancer - Scott Carter Absolute Quantification of Somatic DNA Alterations in Human Cancer - Scott Carter, TCGA Scientific Symposium 2011 You

  9. Improved Strategies and Optimization of Calibration Models for Real-time PCR Absolute Quantification

    EPA Science Inventory

    Real-time PCR absolute quantification applications rely on the use of standard curves to make estimates of DNA target concentrations in unknown samples. Traditional absolute quantification approaches dictate that a standard curve must accompany each experimental run. However, t...

  10. A LEAST ABSOLUTE BOUND APPROACH TO ICA --APPLICATION TO THE MLSP 2006 COMPETITION

    E-print Network

    Verleysen, Michel

    A LEAST ABSOLUTE BOUND APPROACH TO ICA -- APPLICATION TO THE MLSP 2006 COMPETITION John A. Lee, Fr approach as a way to solve the ICA problems proposed in the 2006 MSLP competition. The least absolute bound to the sources involved in the competition. Practically, the minimization of the least absolute bound relies

  11. A Wireless Batch Sealed Absolute Capacitive Pressure Sensor Orhan Akar1

    E-print Network

    Akin, Tayfun

    A Wireless Batch Sealed Absolute Capacitive Pressure Sensor Orhan Akar1 , Tayfun Akin1 , Tim/mmHg, respectively. Keywords: wireless sensor, sealed sensor, and capacitive pressure sensor Introduction Absolute. However, to fabricate absolute pressure sensors with sealed cavities that also allow easy lead transfer

  12. Absolute Instability of a Liquid Jet in a Coflowing Stream Andrew S. Utada,1

    E-print Network

    of disturbances that are either convective or absolute in nature. Convective instabilities grow in amplitude on these jets above a critical value, the insta- bility transitions from absolute to convective. We confirmAbsolute Instability of a Liquid Jet in a Coflowing Stream Andrew S. Utada,1 Alberto Fernandez

  13. Physica D 145 (2000) 233277 Absolute and convective instabilities of waves

    E-print Network

    Scheel, Arnd

    2000-01-01

    Physica D 145 (2000) 233­277 Absolute and convective instabilities of waves on unbounded and large of the absolute spectrum implies convective instability of the wave, but that convectively unstable waves can waves; Essential spectrum; Absolute instability; Convective instability; Domain truncation 1

  14. A Special Application of Absolute Value Techniques in Authentic Problem Solving

    ERIC Educational Resources Information Center

    Stupel, Moshe

    2013-01-01

    There are at least five different equivalent definitions of the absolute value concept. In instances where the task is an equation or inequality with only one or two absolute value expressions, it is a worthy educational experience for learners to solve the task using each one of the definitions. On the other hand, if more than two absolute value…

  15. Absolute Earthquake Locations with Differential Data By William Menke and David Schaff

    E-print Network

    Menke, William

    Absolute Earthquake Locations with Differential Data By William Menke and David Schaff Lamont the commonly-held wisdom that "you can't determine the absolute location of earthquakes using the double differential arrival time data can, in principle, be used to determine the absolute locations of earthquakes

  16. Constraint on Absolute Accuracy of Metacomprehension Assessments: The Anchoring and Adjustment Model vs. the Standards Model

    ERIC Educational Resources Information Center

    Kwon, Heekyung

    2011-01-01

    The objective of this study is to provide a systematic account of three typical phenomena surrounding absolute accuracy of metacomprehension assessments: (1) the absolute accuracy of predictions is typically quite low; (2) there exist individual differences in absolute accuracy of predictions as a function of reading skill; and (3) postdictions…

  17. January 1996 NREUfP-463-20619 Calibration of a Solar Absolute

    E-print Network

    . A description of absolute cavity radiometers is also included, using a PMO-6 as an example of active cavityJanuary 1996 · NREUfP-463-20619 Calibration of a Solar Absolute Cavity Radiometer with Traceability Engineering) Calibration of a Solar Absolute Cavity Radiometer with Traceability to the World Radiometric

  18. Experiment analysis of freeform testing based on absolute testing method

    NASA Astrophysics Data System (ADS)

    Jia, Xin; Xu, Fuchao; Xing, Tingwen

    2014-07-01

    Requirements for the measurement resolution in the sub-nanometer range have become quite common which includes not only the repeatability or reproducibility but also the absolute measurement accuracy. The freeform lens for wavefront compensating contains some medium spatial frequency terms. The wavefront error of lithographic object lens is very small. One method to reduce the wavefront error of lithographic object lens is to use the freeform lens. The freeform lens for compensation needs more accuracy than the object lens. We can also use freeform lens of sphere or aspheric for compensation. The testing accuracy of sphere and aspheric lens are hard to achieve 1nm. The sphere and aspheric will contain the power term and are hard to find the cat-eye. The ion beam figure system (IBF) is the best polishing machine for nanometer manufacture which will polish the PV of 2um for several weeks even months. Usually we use the PV 200nm lens for compensation. So the freeform for compensation looks like a flat. In this paper we will show the testing experiment of the freeform and the testing problem. The freeform surface is created by 66 Zernike polynomials which are based on the flat lens. The freeform flat is polished by the ion figuring machine of NTG. The environment such as temperature, vibration, humidity is controlled well. The Zygo's interferometer Verifire Ashpere with absolute testing method is used to test the freeform. Position Accuracy is a problem in optical testing and manufacture. The high accuracy testing can't be determined by one method, we need the different method to compare the result especially these method will contain some defects. The defects of the recently absolute testing method are discussed.

  19. Absolute Paleointensity Study of Miocene Tiva Canyon Tuff, Yucca Mountain, Nevada

    NASA Astrophysics Data System (ADS)

    Patiman, A.; Bowles, J.

    2014-12-01

    Unoriented samples from the ~12.7 Ma Tiva Canyon (TC) tuff from Yucca Mountain, Nevada are studied in terms of magnetic properties and geomagnetic paleointensity. The magnetic mineralogy and magnetic properties of the TC tuff have previously been well documented, and the remanence-carrier in ~15-m thick zones at the top and bottom of the unit is dominantly is single domain (SD) to superparamagnetic (SP) magnetite, which may be considered ideal for absolute paleointensity studies. Among one of the several episodic volcanic eruptions of the Southwestern Nevada Volcanic Field (SWNVF), the welded TC tuff belongs to the Paintbrush Group. Here we present magnetic properties from two previously unreported sections of the TC tuff, as well as Thellier-type absolute paleointensity estimates. Samples were collected from the lower ~7 m at the base of the flow. Magnetic properties studied include hysteresis, bulk magnetic susceptibility, frequency-dependent susceptibility, and anhysteretic remanent magnetization acquisition. Magnetic property results are consistent with earlier work, showing that the main magnetic mineral is magnetite. SP samples are dominant from the lower ~1 m to ~3.6 m basal unit while the middle unit of ~3.7 m to 7.0 m mainly consists of SD samples. The paleointensity results are closely tied to the stratigraphic height and magnetic properties linked to domain state. The SD samples have consistent absolute paleointensity values 32.40±0.22 uT, VADM 5.74*1022 A.m2 and behaved ideally during paleointensity experiments. The SP samples have consistently higher paleointensity and less ideal behavior, but would likely pass many traditional quality-control tests. Since the magnetite has been interpreted to form by precipitation out of the glass post-emplacement, but at temperatures higher than the Curie temperature, we tentatively interpret the SD remanence to be a primary thermal remanent magnetization and the paleointensity result to be a valid estimate of geomagnetic paleointensity for the Miocene. Post-emplacement vapor-phase alteration might be expected to alter magnetic mineralogy and magnetization, and has been reported in the upper portions of the TC tuff, but not in the lower sections discussed here.

  20. Absolute coverage of the saturated cesium silicon interfaces

    NASA Astrophysics Data System (ADS)

    Sherman, William Benjamin

    Metal/semiconductor interfaces are of great interest for a variety of reasons. They shed light on surface metal/semiconductor transitions, and they form Schottky barriers, which are of scientific as well as significant technological importance (primarily for the production of high speed, low-power logic circuitry). The cesium/silicon interfaces are of particular interest since the oxide forms a Negative Electron Affinity state. Cesium does not mix with the bulk silicon, so the interface is very abrupt, and the electronic structure of cesium is easier to understand than that of the transition metals. Further, cesium (like other alkali metals at room temperature) forms a single atomic layer on the various silicon faces and then the coverage saturates (i.e. atoms stop sticking to the surface). This makes the cesium/silicon interfaces ideal model systems of the metal/semiconductor interface. In spite of their importance, the detailed structures of the cesium saturated silicon faces are still uncertain. Numerous structural models have been proposed and many of them have quite different absolute coverages. Thus absolute coverage measurements can effectively distinguish between the various models. Rutherford Backscattering Spectrometry (RBS) provides an ideal measurement of absolute coverage since its results can be directly interpreted without dependence upon any structural model. A new beam line has been set up on the Laboratory for Research on the Structure of Matter's tandem accelerator. The Ultrahigh Vacuum system is equipped with an Auger Electron Spectrometer, a Low Energy Electron Diffraction system, a retarding field method work function analyzer, a cesium doser, a Medium Energy Ion Scattering two dimensional toroidal analyzer and a Rutherford Backscattering: Spectrometry (RBS) solid state ion detector. It has been used to manufacture saturated Cs/Si(100)-2 x 1 and Cs/Si(111)-7 x 7 interfaces and measure their absolute coverage via RBS. The coverage for the Si(111)-7 x 7 surface was found to be 4.0 +/- 0.2 x 1015 atoms/cm2 , rejecting the structural model of Magnusson et al. and supporting the model of Eteldaniemi et al. The coverage for the Si(100)-2 x 1 surface was found to be 3.7 +/- 0.1 x 1015 atoms/cm2, rejecting the Abukawa and Kono model of the interface, and supporting the Levine (or a similar) model.

  1. Strategy for the absolute neutron emission measurement on ITER

    SciTech Connect

    Sasao, M.; Bertalot, L.; Ishikawa, M.; Popovichev, S.

    2010-10-15

    Accuracy of 10% is demanded to the absolute fusion measurement on ITER. To achieve this accuracy, a functional combination of several types of neutron measurement subsystem, cross calibration among them, and in situ calibration are needed. Neutron transport calculation shows the suitable calibration source is a DT/DD neutron generator of source strength higher than 10{sup 10} n/s (neutron/second) for DT and 10{sup 8} n/s for DD. It will take eight weeks at the minimum with this source to calibrate flux monitors, profile monitors, and the activation system.

  2. Absolute polarization measurement using a vector light shift.

    PubMed

    Zhu, Kunyan; Solmeyer, Neal; Tang, Cheng; Weiss, David S

    2013-12-13

    We have measured the vector light shift due to a cavity built-up optical lattice by using a variation of the Hanle effect with trapped Cs atoms, where the time-evolving population of all magnetic sublevels is measured in situ. The measurement is linearly sensitive to the electric field of the nonlinearly polarized light, which allows unprecedented sensitivity to absolute linear polarization quality, to the level of 10(-10) in fractional intensity. Our approach to measuring and improving linear polarization can be applied to electron electric dipole moment searches, optical lattice clocks, magnetometery, and quantum computing. PMID:24483655

  3. Observation of negative absolute resistance in a Josephson junction

    E-print Network

    J. Nagel; D. Speer; T. Gaber; A. Sterck; R. Eichhorn; P. Reimann; K. Ilin; M. Siegel; D. Koelle; R. Kleiner

    2008-01-28

    We experimentally demonstrate the occurrence of negative absolute resistance (NAR) up to about $-1\\Omega$ in response to an externally applied dc current for a shunted Nb-Al/AlO$_x$-Nb Josephson junction, exposed to a microwave current at frequencies in the GHz range. The realization (or not) of NAR depends crucially on the amplitude of the applied microwave current. Theoretically, the system is described by means of the resistively and capacitively shunted junction model in terms of a moderately damped, classical Brownian particle dynamics in a one-dimensional potential. We find excellent agreement of the experimental results with numerical simulations of the model.

  4. On the convective-absolute nature of river bedform instabilities

    NASA Astrophysics Data System (ADS)

    Vesipa, Riccardo; Camporeale, Carlo; Ridolfi, Luca; Chomaz, Jean Marc

    2014-12-01

    River dunes and antidunes are induced by the morphological instability of stream-sediment boundary. Such bedforms raise a number of subtle theoretical questions and are crucial for many engineering and environmental problems. Despite their importance, the absolute/convective nature of the instability has never been addressed. The present work fills this gap as we demonstrate, by the cusp map method, that dune instability is convective for all values of the physical control parameters, while the antidune instability exhibits both behaviors. These theoretical predictions explain some previous experimental and numerical observations and are important to correctly plan flume experiments, numerical simulations, paleo-hydraulic reconstructions, and river works.

  5. Quantum Bath Refrigeration towards Absolute Zero: Challenging the Unattainability Principle

    NASA Astrophysics Data System (ADS)

    Kolá?, M.; Gelbwaser-Klimovsky, D.; Alicki, R.; Kurizki, G.

    2012-08-01

    A minimal model of a quantum refrigerator, i.e., a periodically phase-flipped two-level system permanently coupled to a finite-capacity bath (cold bath) and an infinite heat dump (hot bath), is introduced and used to investigate the cooling of the cold bath towards absolute zero (T=0). Remarkably, the temperature scaling of the cold-bath cooling rate reveals that it does not vanish as T?0 for certain realistic quantized baths, e.g., phonons in strongly disordered media (fractons) or quantized spin waves in ferromagnets (magnons). This result challenges Nernst’s third-law formulation known as the unattainability principle.

  6. Lens transmission measurement for an absolute radiation thermometer

    SciTech Connect

    Hao, X.; Yuan, Z.; Lu, X.

    2013-09-11

    The lens transmission for the National Institute of Metrology of China absolute radiation thermometer is measured by a hybrid method. The results of the lens transmission measurements are 99.002% and 86.792% for filter radiometers with center wavelengths 633 nm and 900 nm, respectively. These results, after correcting for diffraction factors and the size-of-source effect when the lens is incorporated within the radiometer, can be used for measurement of thermodynamic temperature. The expanded uncertainty of the lens transmission measurement system has been evaluated. It is 1.3×10{sup ?3} at 633 nm and 900 nm, respectively.

  7. Method of differential-phase/absolute-amplitude QAM

    DOEpatents

    Dimsdle, Jeffrey William (Overland Park, KS)

    2009-09-01

    A method of quadrature amplitude modulation involving encoding phase differentially and amplitude absolutely, allowing for a high data rate and spectral efficiency in data transmission and other communication applications, and allowing for amplitude scaling to facilitate data recovery; amplitude scale tracking to track-out rapid and severe scale variations and facilitate successful demodulation and data retrieval; 2.sup.N power carrier recovery; incoherent demodulation where coherent carrier recovery is not possible or practical due to signal degradation; coherent demodulation; multipath equalization to equalize frequency dependent multipath; and demodulation filtering.

  8. Structure and absolute configuration of the fungal ansabenzoquinone rhizopogone.

    PubMed

    Lang, Martin; Jägers, Erhard; Polborn, Kurt; Steglich, Wolfgang

    2009-02-27

    The main pigment of the basidiomycete Rhizopogon pumilionus is the [13]paracyclophane derivative rhizopogone (1). The structures of 1 and the accompanying 2-acetoxyrhizopogone (5) were determined by spectroscopic studies, including 1D and 2D NMR measurements. The absolute configuration of 1 was assigned by comparison of its CD spectrum with that of secotridentoquinone (4). The structures of 1 and tridentoquinone (3) suggest a common biosynthesis originating from 2-geranylgeranyl-6-hydroxy-1,4-benzoquinone (9). This supports the close taxonomic relationship of the genera Rhizopogon and Suillus (Boletales). PMID:19175325

  9. Method of differential-phase/absolute-amplitude QAM

    DOEpatents

    Dimsdle, Jeffrey William (Overland Park, KS)

    2007-07-03

    A method of quadrature amplitude modulation involving encoding phase differentially and amplitude absolutely, allowing for a high data rate and spectral efficiency in data transmission and other communication applications, and allowing for amplitude scaling to facilitate data recovery; amplitude scale tracking to track-out rapid and severe scale variations and facilitate successful demodulation and data retrieval; 2.sup.N power carrier recovery; incoherent demodulation where coherent carrier recovery is not possible or practical due to signal degradation; coherent demodulation; multipath equalization to equalize frequency dependent multipath; and demodulation filtering.

  10. Method of differential-phase/absolute-amplitude QAM

    DOEpatents

    Dimsdle, Jeffrey William (Overland Park, KS)

    2008-10-21

    A method of quadrature amplitude modulation involving encoding phase differentially and amplitude absolutely, allowing for a high data rate and spectral efficiency in data transmission and other communication applications, and allowing for amplitude scaling to facilitate data recovery; amplitude scale tracking to track-out rapid and severe scale variations and facilitate successful demodulation and data retrieval; 2.sup.N power carrier recovery; incoherent demodulation where coherent carrier recovery is not possible or practical due to signal degradation; coherent demodulation; multipath equalization to equalize frequency dependent multipath; and demodulation filtering.

  11. Method of differential-phase/absolute-amplitude QAM

    DOEpatents

    Dimsdle, Jeffrey William (Overland Park, KS)

    2007-07-17

    A method of quadrature amplitude modulation involving encoding phase differentially and amplitude absolutely, allowing for a high data rate and spectral efficiency in data transmission and other communication applications, and allowing for amplitude scaling to facilitate data recovery; amplitude scale tracking to track-out rapid and severe scale variations and facilitate successful demodulation and data retrieval; 2.sup.N power carrier recovery; incoherent demodulation where coherent carrier recovery is not possible or practical due to signal degradation; coherent demodulation; multipath equalization to equalize frequency dependent multipath; and demodulation filtering.

  12. Method of differential-phase/absolute-amplitude QAM

    DOEpatents

    Dimsdle, Jeffrey William (Overland Park, KS)

    2007-10-02

    A method of quadrature amplitude modulation involving encoding phase differentially and amplitude absolutely, allowing for a high data rate and spectral efficiency in data transmission and other communication applications, and allowing for amplitude scaling to facilitate data recovery; amplitude scale tracking to track-out rapid and severe scale variations and facilitate successful demodulation and data retrieval; 2.sup.N power carrier recovery; incoherent demodulation where coherent carrier recovery is not possible or practical due to signal degradation; coherent demodulation; multipath equalization to equalize frequency dependent multipath; and demodulation filtering.

  13. Spatially resolved absolute spectrophotometry of Saturn - 3390 to 8080 A

    NASA Technical Reports Server (NTRS)

    Bergstralh, J. T.; Diner, D. J.; Baines, K. H.; Neff, J. S.; Allen, M. A.; Orton, G. S.

    1981-01-01

    A series of spatially resolved absolute spectrophotometric measurements of Saturn was conducted for the expressed purpose of calibrating the data obtained with the Imaging Photopolarimeter (IPP) on Pioneer 11 during its recent encounter with Saturn. All observations reported were made at the Mt. Wilson 1.5-m telescope, using a 1-m Ebert-Fastie scanning spectrometer. Spatial resolution was 1.92 arcsec. Photometric errors are considered, taking into account the fixed error, the variable error, and the composite error. The results are compared with earlier observations, as well as with synthetic spectra derived from preliminary physical models, giving attention to the equatorial region and the South Temperate Zone.

  14. Precision Absolute Beam Current Measurement of Low Power Electron Beam

    SciTech Connect

    Ali, M. M.; Bevins, M. E.; Degtiarenko, P.; Freyberger, A.; Krafft, G. A.

    2012-11-01

    Precise measurements of low power CW electron beam current for the Jefferson Lab Nuclear Physics program have been performed using a Tungsten calorimeter. This paper describes the rationale for the choice of the calorimeter technique, as well as the design and calibration of the device. The calorimeter is in use presently to provide a 1% absolute current measurement of CW electron beam with 50 to 500 nA of average beam current and 1-3 GeV beam energy. Results from these recent measurements will also be presented.

  15. Determination of partial specific volume and absolute concentration by densimetry.

    PubMed Central

    Stothart, P H

    1984-01-01

    The apparent partial specific volume, phi, of a protein (or other macromolecule) and the absolute concentration, c, can be determined from the densimetry of solutions and diffusates in 1H2O , 2H2O and 1H2O/2H2O mixtures if the ratios of concentrations (relative concentrations) are known. The densimetry method allows a non-destructive check on total macromolecule concentrations without prior knowledge of specific u.v.-absorption coefficient. The method may be especially useful in small-angle neutron-scattering studies. PMID:6743240

  16. Closed-loop step motor control using absolute encoders

    SciTech Connect

    Hicks, J.S.; Wright, M.C.

    1997-08-01

    A multi-axis, step motor control system was developed to accurately position and control the operation of a triple axis spectrometer at the High Flux Isotope Reactor (HFIR) located at Oak Ridge National Laboratory. Triple axis spectrometers are used in neutron scattering and diffraction experiments and require highly accurate positioning. This motion control system can handle up to 16 axes of motion. Four of these axes are outfitted with 17-bit absolute encoders. These four axes are controlled with a software feedback loop that terminates the move based on real-time position information from the absolute encoders. Because the final position of the actuator is used to stop the motion of the step motors, the moves can be made accurately in spite of the large amount of mechanical backlash from a chain drive between the motors and the spectrometer arms. A modified trapezoidal profile, custom C software, and an industrial PC, were used to achieve a positioning accuracy of 0.00275 degrees of rotation. A form of active position maintenance ensures that the angles are maintained with zero error or drift.

  17. Communication: The absolute shielding scales of oxygen and sulfur revisited

    SciTech Connect

    Komorovsky, Stanislav; Repisky, Michal; Malkin, Elena; Ruud, Kenneth; Gauss, Jürgen

    2015-03-07

    We present an updated semi-experimental absolute shielding scale for the {sup 17}O and {sup 33}S nuclei. These new shielding scales are based on accurate rotational microwave data for the spin–rotation constants of H{sub 2}{sup 17}O [Puzzarini et al., J. Chem. Phys. 131, 234304 (2009)], C{sup 17}O [Cazzoli et al., Phys. Chem. Chem. Phys. 4, 3575 (2002)], and H{sub 2}{sup 33}S [Helgaker et al., J. Chem. Phys. 139, 244308 (2013)] corrected both for vibrational and temperature effects estimated at the CCSD(T) level of theory as well as for the relativistic corrections to the relation between the spin–rotation constant and the absolute shielding constant. Our best estimate for the oxygen shielding constants of H{sub 2}{sup 17}O is 328.4(3) ppm and for C{sup 17}O ?59.05(59) ppm. The relativistic correction for the sulfur shielding of H{sub 2}{sup 33}S amounts to 3.3%, and the new sulfur shielding constant for this molecule is 742.9(4.6) ppm.

  18. Absolute cross sections for elastic electron scattering from 3-hydroxytetrahydrofuran

    NASA Astrophysics Data System (ADS)

    Milosavljevi?, A. R.; Blanco, F.; Maljkovi?, J. B.; Ševi?, D.; García, G.; Marinkovi?, B. P.

    2008-10-01

    The results of measurements and calculations of absolute cross sections for elastic electron scattering from the 3-hydroxytetrahydrofuran (3hTHF) (C4H8O2) molecule are reported. The measurements were performed using a crossed beam experimental setup, for an incident electron energy range of 40 300 eV and an overall scattering angle range of 10° 110°. Relative differential cross sections (DCSs) were measured both as a function of the angle and the incident energy and the absolute DCSs were determined using the relative flow technique. The calculations of molecular cross sections are based on a corrected form of the independent-atom method, known as the screen corrected additivity rule (SCAR) procedure and using an improved quasifree absorption model. Additional calculations are also done to investigate the influence of rotational excitations and low-angular behavior of SCAR DCSs. The calculated dataset includes differential, integral and total cross sections in the energy range from 5 eV to 10 000 eV. The present results are discussed regarding the most recent low-energy elastic DCSs for 3hTHF (Vizcaino et al 2008 New J. Phys. 10 053002), as well as the recent DCSs for molecules of similar structure (tetrahydrofuran and tetrahydrofurfuryl alcohol).

  19. Absolute phase effects on CPMG-type pulse sequences.

    PubMed

    Mandal, Soumyajit; Oh, Sangwon; Hürlimann, Martin D

    2015-12-01

    We describe and analyze the effects of transients within radio-frequency (RF) pulses on multiple-pulse NMR measurements such as the well-known Carr-Purcell-Meiboom-Gill (CPMG) sequence. These transients are functions of the absolute RF phases at the beginning and end of the pulse, and are thus affected by the timing of the pulse sequence with respect to the period of the RF waveform. Changes in transients between refocusing pulses in CPMG-type sequences can result in signal decay, persistent oscillations, changes in echo shape, and other effects. We have explored such effects by performing experiments in two different low-frequency NMR systems. The first uses a conventional tuned-and-matched probe circuit, while the second uses an ultra-broadband un-tuned or non-resonant probe circuit. We show that there are distinct differences between the absolute phase effects in these two systems, and present simple models that explain these differences. PMID:26575106

  20. Note: Absolute photoionization cross-section of the vinyl radical

    NASA Astrophysics Data System (ADS)

    Savee, John D.; Lockyear, Jessica F.; Borkar, Sampada; Eskola, Arkke J.; Welz, Oliver; Taatjes, Craig A.; Osborn, David L.

    2013-08-01

    This work measures the absolute photoionization cross-section of the vinyl radical (?vinyl(E)) between 8.1 and 11.0 eV. Two different methods were used to obtain absolute cross-section measurements: 193 nm photodissociation of methyl vinyl ketone (MVK) and 248 nm photodissociation of vinyl iodide (VI). The values of the photoionization cross-section for the vinyl radical using MVK, ?vinyl(10.224 eV) = (6.1 ± 1.4) Mb and ?vinyl(10.424 eV) = (8.3 ± 1.9) Mb, and using VI, ?vinyl(10.013 eV) = (4.7 ± 1.1) Mb, ?vinyl(10.513 eV) = (9.0 ± 2.1) Mb, and ?vinyl(10.813 eV) = (12.1 ± 2.9) Mb, define a photoionization cross-section that is ˜1.7 times smaller than a previous determination of this value.

  1. The Absolute Magnitude of RRc Variables From Statistical Parallax

    E-print Network

    Kollmeier, Juna A; Burns, Christopher R; Gould, Andrew; Thompson, Ian B; Preston, George W; Sneden, Christopher; Crane, Jeffrey D; Dong, Subo; Madore, Barry F; Morrell, Nidia; Prieto, Jose L; Shectman, Stephen; Simon, Joshua D; Villanueva, Edward

    2012-01-01

    We present the first definitive measurement of the absolute magnitude of RR Lyrae c-type variable stars (RRc) determined purely from statistical parallax. We use a sample of 247 RRc selected from the All Sky Automated Survey (ASAS) for which high-quality light curves, photometry and proper motions are available. We obtain high-resolution echelle spectra for these objects to determine radial velocities and abundances as part of the Carnegie RR Lyrae Survey (CARRS). We find that M_(V,RRc) = 0.52 +/- 0.11 at a mean metallicity of [Fe/H] = -1.59. This is to be compared with previous estimates for RRab stars (M_(V,RRab) = 0.75 +/- 0.13 and the only direct measurement of an RRc absolute magnitude (RZ Cephei, M_(V, RRc) = 0.27 +/- 0.17). We find the bulk velocity of the halo to be (W_pi, W_theta, W_z) = (10.9,34.9,7.2) km/s in the radial, rotational and vertical directions with dispersions (sigma_(W_pi), sigma_(W_theta), sigma_(W_z)) = (154.7, 103.6, 93.8) km/s. For the disk, we find (W_pi, W_theta, W_z) = (8.5, 213...

  2. Obtaining absolute acoustic spectra in an aerodynamic wind tunnel

    NASA Astrophysics Data System (ADS)

    Quayle, Alexander R.; Dowling, Ann P.; Graham, W. R.; Babinsky, H.

    2011-05-01

    Cost effective methods for identifying and reducing sources of noise have become essential in the design of many modern transport vehicles. Whilst closed-section wind tunnels can readily evaluate aerodynamic performance, obtaining accurate acoustic spectra is often a major challenge because of the poor signal to noise ratios available. In this paper, methods of obtaining absolute spectra from the non-acoustically treated Markham wind tunnel at the University of Cambridge are discussed. Initial measurements with a small monopole source compare well with simulations and show that it is possible to obtain similar spectra from two nested acoustic arrays. However, a series of further experiments with simplified landing gear models show very different spectra from each array. By comparing measurements with simulations, it is shown that negative side lobes affect beamforming source maps. Measurements of an 'empty tunnel' cross spectral matrix allow the removal of sidelobes, providing much greater consistency between spectra. Finally, a dipole beamforming vector is used to account for the directivity of the landing gear noise, leading to good agreement between absolute spectra from the differently sized arrays. This analysis demonstrates that data from a phased array in a hard-walled, aerodynamic wind tunnel can provide meaningful acoustic spectra from low-noise models.

  3. Absolute analytical prediction of photonic crystal guided mode resonance wavelengths

    SciTech Connect

    Hermannsson, Pétur Gordon; Vannahme, Christoph; Smith, Cameron L. C.; Kristensen, Anders

    2014-08-18

    A class of photonic crystal resonant reflectors known as guided mode resonant filters are optical structures that are widely used in the field of refractive index sensing, particularly in biosensing. For the purposes of understanding and design, their behavior has traditionally been modeled numerically with methods such as rigorous coupled wave analysis. Here it is demonstrated how the absolute resonance wavelengths of such structures can be predicted by analytically modeling them as slab waveguides in which the propagation constant is determined by a phase matching condition. The model is experimentally verified to be capable of predicting the absolute resonance wavelengths to an accuracy of within 0.75?nm, as well as resonance wavelength shifts due to changes in cladding index within an accuracy of 0.45?nm across the visible wavelength regime in the case where material dispersion is taken into account. Furthermore, it is demonstrated that the model is valid beyond the limit of low grating modulation, for periodically discontinuous waveguide layers, high refractive index contrasts, and highly dispersive media.

  4. Absolute and relative quantification of RNA modifications via biosynthetic isotopomers

    PubMed Central

    Kellner, Stefanie; Ochel, Antonia; Thüring, Kathrin; Spenkuch, Felix; Neumann, Jennifer; Sharma, Sunny; Entian, Karl-Dieter; Schneider, Dirk; Helm, Mark

    2014-01-01

    In the resurging field of RNA modifications, quantification is a bottleneck blocking many exciting avenues. With currently over 150 known nucleoside alterations, detection and quantification methods must encompass multiple modifications for a comprehensive profile. LC–MS/MS approaches offer a perspective for comprehensive parallel quantification of all the various modifications found in total RNA of a given organism. By feeding 13C-glucose as sole carbon source, we have generated a stable isotope-labeled internal standard (SIL-IS) for bacterial RNA, which facilitates relative comparison of all modifications. While conventional SIL-IS approaches require the chemical synthesis of single modifications in weighable quantities, this SIL-IS consists of a nucleoside mixture covering all detectable RNA modifications of Escherichia coli, yet in small and initially unknown quantities. For absolute in addition to relative quantification, those quantities were determined by a combination of external calibration and sample spiking of the biosynthetic SIL-IS. For each nucleoside, we thus obtained a very robust relative response factor, which permits direct conversion of the MS signal to absolute amounts of substance. The application of the validated SIL-IS allowed highly precise quantification with standard deviations <2% during a 12-week period, and a linear dynamic range that was extended by two orders of magnitude. PMID:25129236

  5. Dynamic modeling of predictive uncertainty by regression on absolute errors

    NASA Astrophysics Data System (ADS)

    Pianosi, F.; Raso, L.

    2012-03-01

    Uncertainty of hydrological forecasts represents valuable information for water managers and hydrologists. This explains the popularity of probabilistic models, which provide the entire distribution of the hydrological forecast. Nevertheless, many existing hydrological models are deterministic and provide point estimates of the variable of interest. Often, the model residual error is assumed to be homoscedastic; however, practical evidence shows that the hypothesis usually does not hold. In this paper we propose a simple and effective method to quantify predictive uncertainty of deterministic hydrological models affected by heteroscedastic residual errors. It considers the error variance as a hydrological process separate from that of the hydrological forecast and therefore predictable by an independent model. The variance model is built up using time series of model residuals, and under some conditions on the same residuals, it is applicable to any deterministic model. Tools for regression analysis applied to the time series of residual errors, or better their absolute values, combined with physical considerations of the hydrological features of the system can help to identify the most suitable input to the variance model and the most parsimonious model structure, including dynamic structure if needed. The approach has been called dynamic uncertainty modeling by regression on absolute errors and is demonstrated by application to two test cases, both affected by heteroscedasticity but with very different dynamics of uncertainty. Modeling results and comparison with other approaches, i.e., a constant, a cyclostationary, and a static model of the variance, confirm the validity of the proposed method.

  6. Simulation of absolute amplitudes of ultrasound signals using equivalent circuits.

    PubMed

    Johansson, Jonny; Martinsson, Pär-Erik; Delsing, Jerker

    2007-10-01

    Equivalent circuits for piezoelectric devices and ultrasonic transmission media can be used to cosimulate electronics and ultrasound parts in simulators originally intended for electronics. To achieve efficient system-level optimization, it is important to simulate correct, absolute amplitude of the ultrasound signal in the system, as this determines the requirements on the electronics regarding dynamic range, circuit noise, and power consumption. This paper presents methods to achieve correct, absolute amplitude of an ultrasound signal in a simulation of a pulse-echo system using equivalent circuits. This is achieved by taking into consideration loss due to diffraction and the effect of the cable that connects the electronics and the piezoelectric transducer. The conductive loss in the transmission line that models the propagation media of the ultrasound pulse is used to model the loss due to diffraction. Results show that the simulated amplitude of the echo follows measured values well in both near and far fields, with an offset of about 10%. The use of a coaxial cable introduces inductance and capacitance that affect the amplitude of a received echo. Amplitude variations of 60% were observed when the cable length was varied between 0.07 m and 2.3 m, with simulations predicting similar variations. The high precision in the achieved results show that electronic design and system optimization can rely on system simulations alone. This will simplify the development of integrated electronics aimed at ultrasound systems. PMID:18019234

  7. Absolute surface energies, fracture toughness, and cracking in nitrides

    NASA Astrophysics Data System (ADS)

    Dreyer, Cyrus E.; Janotti, Anderson; van de Walle, Chris G.

    2014-03-01

    Growth of high quality single crystals and epitaxial layers of GaN is critical for producing high-efficiency optoelectronic and power electronic devices. One of the fundamental material properties that govern growth of single crystals is the absolute surface energy of the crystallographic planes. Knowledge of these energies is required to understand and optimize growth rates of different facets in GaN, and provide fracture toughnesses for brittle fracture. By means of hybrid functional calculations, we have determined absolute surface energies for the non-polar {11-20} a and {10-10} m planes, and approximated values for polar (0001) + c and (000-1) - c planes in wurtzite GaN. For all surfaces, we consider low-energy bare and hydrogenated reconstructions under a variety of conditions relevant to experimental growth techniques. We find that the energies of the m and a planes are similar, and constant over the range of conditions studied. In contrast, the energies of the polar planes are strongly condition dependent. Even so, we find that the + c polar plane is systematically lower in energy than the - c plane. We have used our surface energies to determine brittle fracture toughnesses in AlN and GaN, as well as the critical thickness for cracking of AlGaN on GaN.

  8. Thermal entanglement of a coupled electronic spins system: interplay between an external magnetic field, nuclear field and spin-orbit interaction

    NASA Astrophysics Data System (ADS)

    Guerrero M., Roberto J.; Rojas, F.

    2015-06-01

    We have studied the thermal entanglement as a function of the temperature for a two-qubits Heisenberg spins system; we have included Dzyaloshinskii-Moriya interaction (DM), an external magnetic field (EMF) and hyperfine interaction due to the nuclear field of the surrounding nuclei. A critical value for the EMF was found, around mT, which characterizes two regimes of behavior of the thermal entanglement. Our results show that the DM term acts as a facilitator for the entanglement because it prolongs the nonzero thermal entanglement for larger temperatures. We found that the concurrence as a function of the temperature has a local maximum, for values of the magnetic field larger than the critical field. We also show that the critical temperature follows a polynomial growth as a function of the DM term, with characteristic behavior , and the hyperfine field implies a critical temperature as a function of the field variance, of the form . We show that in this system, the entanglement measure by the concurrence and the one-spin polarization observable exhibit opposite behavior, providing a method to obtain the entanglement from the measurement of an observable.

  9. Absolute and relative satellite-to-satellite navigation using GPS

    NASA Astrophysics Data System (ADS)

    Binning, Patrick William

    This dissertation describes the methods and implementation of extended Kalman filtering, backwards smoothing and carrier phase integer ambiguity resolution for the problem of absolute satellite orbit determination and satellite to satellite relative navigation while using measurements from the Global Positioning System (GPS). All data are considered to be taken from both frequencies of the GPS constellation. Also, the data is considered to be free from the effects of Selective Availability (SA) although this feature is briefly addressed. The absolute navigation techniques are applied to actual data obtained from the TOPEX/Poseidon satellite as well as simulated data. The algorithms are used to estimate the position, velocity, clock offset, and frequency offset. The simulated data are derived from two sources: a software simulator, and a Northern Telecom GPS signal simulator used in conjunction with an Allen Osborne Associates TurboRogue receiver. Four algorithms are presented in the area of relative satellite to satellite navigation. These can be separated into two categories: those that base the relative state update using only the GPS pseudorange, and those that base the relative state update on the GPS carrier phase only. There are three pseudorange techniques investigated. The first involves straight differencing of two absolute estimates when using the pseudoranges from all observable GPS satellites from each receiver. The second involves using a correlated process noise matrix while processing simultaneous pseudoranges from common view GPS satellites. The relative state for this process is then the difference of the two absolute states. The measurements for both user spacecraft must be taken at the same instant in time for this process to work. A measurement interpolation algorithm is presented in order to solve this problem. The third pseudorange method is the first to estimate the relative state explicitly by employing the single difference pseudorange measurement. The carrier phase technique shows the highest accuracy for relative state estimation. The algorithm in this dissertation utilizes the widelane carrier phase combination of GPS observables. The single difference is then taken between two simultaneous widelane carrier phase measurements. Inherent in this process is the need to determine the widelane integer. A robust algorithm is presented which allows this problem to be solved. The relative navigation algorithms are applied to software and hardware simulated data. A unique aspect of this research involves using a Northern Telecom GPS RF signal generator with an Allen Osborne Associates TurboRogue receiver to simulate measurements from 2 coorbiting receivers. In addition, a software simulator is developed which allows more control over the simulation errors. The absolute navigation 1sigma position errors are 50 cm for a smoothed solution using precise GPS information and 3 to 7 meters when using the broadcast navigation parameters. The most precise pseudorange relative technique demonstrates 1sigma position errors of between 10 cm and 25 cm. The carrier phase technique shows 1sigma position errors on the order of 1.5 cm to 3.0 cm. These statistics are derived from 24 software simulations as well as 20 hardware simulations. A discussion of the cumulative results as well as individual test cases is presented.

  10. Thermal Environments.

    ERIC Educational Resources Information Center

    Rutgers, Norman

    The role that a good thermal environment plays in the educational process is discussed. Design implications arise from an analysis of the heating and ventilating principles as apply to vocational-technical facilities. The importance of integrating thermal components in the total design is emphasized. (JS)

  11. AIAA 2003-4198 Thermal Contact Resistance of Non-

    E-print Network

    Bahrami, Majid

    radius, (mm) B = relative macrocontact radius, aL/bL CS = Carbon Steel c1 = Vickers microhardness = contact conductance, ¡ W/m2 K ¢ Hmic = microhardness, (GPa) H0 = c1 (1.620 /m) c2 , (GPa) k = thermal conductivity, (W/mK) m = mean absolute surface slope, (-) ns = number of microcontacts P = pressure, (Pa) P0 0

  12. Can Naturoptics fund Naturopathic Universities to Develop Interlocked Mentoring Relationships with Proposed Universities to Check Sensitivities of Individuals with Spina Bifida, to Environmentally Generated EMF Information about 'Quakes, Hurricanes, etc.?

    NASA Astrophysics Data System (ADS)

    McLeod, David M.; Ataide, Italani; McLeod, Roger D.

    2006-03-01

    Individuals harboring the herpes zoster virus following chicken pox, are susceptible to attacks of shingles. They may indicate peculiar awareness of pricking `pin and needle' sensations and co-symptoms of tinnitus and/or Meuniere's syndrome. RDM used similar symptoms in FL to predict the earthquake ninety miles north of Guantanamo bay in 1998. An astounding burial site in Florida from over six thousand years ago had a teenaged boy with severe spina bifida, with non-Asian genes, who could not have survived without very capable health support. Two youthful individuals likewise afflicted with spina bifida were unearthed from one site at Pompeii, entombed by the eruption of Vesuvius, August 24 and 25, CE 79. We know how to locate sites, active with EMF, which have tornado, hurricane and earthquake associations, and would like to foster joint research also involving Hawaiian and other volcanoes.

  13. Towards absolute gain calibration of the tactic focal plane cameras

    NASA Astrophysics Data System (ADS)

    Tickoo, A. K.; Dhar, V. K.; Venugopal, K.; Kaul, S. K.; Koul, R.; Bhatt, N.; Kothari, M.; Goyal, H. C.; Chandra, P.; Bhat, C. L.

    2001-08-01

    The TACTIC array of Cerenkov telescopes, set up at Mount Abu in Western India, comprises 4 x 9.5 m2 area light-collector elements configured in a triangular pattern of 20m side. The Imaging Element (IE), placed at the centre of the array, deploys a photomultiplier tube (PMT) based, 349-pixel imaging Cerenkov camera, covering a FoV of ˜ 6° ×6° with a uniform pixel granulation of 0.31° . Each of the 3 Vertex Elements (VE), disposed at the 3 corners of the TACTIC array, uses a PMT-based duplex detector array with 29 detectors of assorted types and sizes in each array element. (Total number of PMTdetectors used in the 3 VE thus adds up to 174 ). Absolute gain-calibration of the PMT used in all the 4 TACTIC elements is mandatory for quantifying the light flux received by each element in response to an atmospheric Cerenkov pulse and thereby estimating the progenitor-particle energy. In case of the TACTIC , we have arranged to perform the necessary calibration in the following two stages(steps): (i) 4 PMT pixels, placed symmetrically at the edges of the 349 pixel imaging camera in the IE and 29 pixel detector array in the 6 VE cameras, have been selected and their single photo-electron equivalent peaks measured at the operating EHT of 1250 V. An 241 Am isotope (alpha-emitter) based light pulser is permanently mounted on these fixed EHT calibration pixels to measure their absolute gains in situ and thus monitor possible variations in it due to changes in ambient temperature and light level during actual observations. The corresponding gains of the other 345 pixels in the IE camera and 123 pixels in the 6 VE cameras are determined by exposing these cameras to a uniform photon field produced by a high intensity LED lamp embedded inside a scintillating/diffusing medium and placed appropriately at a distance of 1m from the focal plane instrumentation. (For 27 solar blind PMT in the VE, the absolute calibration is done beforehand in the laboratory). Details of this in situ calibration facility alongwith first results obtained with the IE will be discussed in the paper.

  14. Accuracy of absolute gravity measurements when measuring crustal deformation

    NASA Astrophysics Data System (ADS)

    van Camp, M.; Williams, S. D.; Francis, O.; Camelbeeck, T.

    2004-12-01

    To observe secular land movements of the order of a few millimetres per year, a very precise instrument with long-term stability is required. This can be achieved using absolute gravimeters, which do not depend on a reference frame. Vertical land movements would modify the gravity at a rate of about -10 nms-2 (1 ? Gal) for 5 mm of uplift. Repeated absolute gravity (AG) measurements have now been performed at several sites for five or more years to constrain, for example, tectonic deformation and post-glacial rebound. It is often assumed that these time series contain only white noise. However, many geodetic data sets have now provided evidence for error sources that introduce large temporal correlations into the data. One common statistical model for many types of geophysical signal (which may contribute to the noise) maybe described as a power-law process. Accounting for the type of noise is very important when estimating gravity variations and their uncertainties. Moreover this can contribute to identify the noise source(s) affecting AG measurements We present an analysis of the error model using 10 years of AG data taken at the Proudman Oceanographic Laboratory (POL) and using 96 AG gravity measurements recorded over a period of 8 years at the Membach station (Belgium). A superconducting gravimeter (SG) is also continuously monitoring gravity variations at this site. The AG set-up white noise is estimated by comparison with the SG series. The coloured environmental noise is estimated using the Maximum Likelihood Estimation (MLE) technique to fit two types of stochastic model to the SG time series, power-law noise and first order Gauss Markov (FOGM) noise. The gravity rate of change and the associated uncertainties as a function of the noise structure are computed. Then we investigate the noise of AG values at frequencies higher than 1 cpd, where a white noise component usually dominates. Finally the POL and Membach experiments are applied to estimate the uncertainties of AG campaigns repeated once or twice a year to monitor crustal deformation. The results from repeated AG campaigns along a profile across the Ardenne and along the UK coastline are presented. Such repeated AG measurements should allow one to constrain gravity rate of change with an uncertainty of 1 nms-2 (or 0.5 mm) after 8 to 15 years. The conclusion is that long-term measurements using absolute gravimeters are appropriate for monitoring slow vertical tectonic deformation.

  15. Monitoring Groundwater Variations Using a Portable Absolute Gravimeter

    NASA Astrophysics Data System (ADS)

    Fukuda, Yoichi; Nishijima, Jun; Hasegawa, Takashi; Sofyan, Yayan; Taniguchi, Makoto; Abidin, Hasanuddin Z.; Delinom, Robert M.

    2010-05-01

    In urbanized areas, one of the urgent problems is to monitor the groundwater variations especially connected with land subsidence. Although the groundwater variations are usually measured by water level meters, gravity measurements can provide us additional information about the water mass movements which should be beneficial for the analyses of groundwater flow and the managements of water resources as well. Therefore, in order to establish a new technique to monitor the groundwater variations by means of the gravity measurements, we investigated the applicability of a portable type absolute gravimeter (Micro-G LaCoste Inc. A10-017). We will report the results of some test measurements in Japan, and the outline of the surveys in Jakarta, Indonesia. As for the absolute gravity measurements, FG-5 of MGL would be more popular. FG-5 is a high precision absolute gravimeter with a 2ugal-accuracy for laboratory use, while the nominal accuracy of A-10 is 10ugal (measurement precision: ±5ugal). In spite of the disadvantage, A-10 is well suited for the field surveys because it is much smaller than FG-5 and can be operated with 12VDC power. The repeated measurements using A10-017 in Kyushu University show good correlations between the measured gravity values and the groundwater levels in nearby observation wells. In a geothermal plant of Takigami, we also observed the gravity changes associated with the cycle of the geothermal fluid. All these test measurements have proved that the gravimeter can achieve a 10ugal (10nm/s2) or better accuracy in the field surveys. In Jakarta, Indonesia, excess groundwater pumping is going on and it causes land subsidence. To reveal the associated gravity changes, we conducted the first gravity survey in August 2008 and the second survey in July 2009. Mainly due to the instrumental troubles during the 2008 surveys, we have not obtained enough reliable data yet. Nevertheless the result obtained so far suggested the gravity increases in the coastal area where the large subsidence has been observed. We plan to conduct the same measurements in 2010 and then we expect to obtain more definite results.

  16. Holographic Thermalization

    E-print Network

    Vijay Balasubramanian; Alice Bernamonti; Jan de Boer; Neil B. Copland; Ben Craps; Esko Keski-Vakkuri; Berndt Müller; Andreas Schäfer; Masaki Shigemori; Wieland Staessens

    2011-03-14

    Using the AdS/CFT correspondence, we probe the scale-dependence of thermalization in strongly coupled field theories following a quench, via calculations of two-point functions, Wilson loops and entanglement entropy in d=2,3,4. In the saddlepoint approximation these probes are computed in AdS space in terms of invariant geometric objects - geodesics, minimal surfaces and minimal volumes. Our calculations for two-dimensional field theories are analytical. In our strongly coupled setting, all probes in all dimensions share certain universal features in their thermalization: (1) a slight delay in the onset of thermalization, (2) an apparent non-analyticity at the endpoint of thermalization, (3) top-down thermalization where the UV thermalizes first. For homogeneous initial conditions the entanglement entropy thermalizes slowest, and sets a timescale for equilibration that saturates a causality bound over the range of scales studied. The growth rate of entanglement entropy density is nearly volume-independent for small volumes, but slows for larger volumes.

  17. Absolute falling-ball viscometer: evaluation of measurement uncertainty

    NASA Astrophysics Data System (ADS)

    Brizard, M.; Megharfi, M.; Verdier, C.

    2005-08-01

    To reduce the uncertainties in measurements obtained by means of capillary viscometers, we developed an absolute falling-ball viscometer. The metrological characterization of this experimental bench is presented for a mineral oil with a viscosity of 30 Pa s by means of two distinct methods described in the GUM (Guide to the Expression of Uncertainty in Measurement). First, the calculation is performed using the law of propagation of uncertainties. Then, because of the increasing use of the techniques of propagation of distributions in metrology, we calculated the measurement uncertainties by a numerical Monte Carlo simulation. Both results were then compared for a confidence interval of 95%. Finally, the viscosity measurements and uncertainties obtained by the falling-ball viscometer were compared against those obtained by a capillary viscometer.

  18. Absolute Calibration of the OMEGA Streaked Optical Pyrometer

    NASA Astrophysics Data System (ADS)

    Gregor, M.; Boni, R.; Sorce, A.; McCoy, C.; Henchen, R. J.; Boehly, T. R.; Celliers, P. M.

    2013-10-01

    High-energy-density-physics (HEDP) experiments often rely on temperature measurements using optical pyrometry. Laser-driven experiments have time scales of picoseconds, requiring the use of a streak camera as a detector. This complicates the already formidable task of absolute calibration. We report on multiple calibration runs that used a NIST-traceable tungsten-filament lamp to calibrate the optical response of the streaked optical pyrometer on OMEGA. This entailed constructing a spectral-response function from measurements and estimates of the transmissions and responses of all components in the system as well as measurements using narrowband (30-nm) optical filters. The latter is used to normalize the estimated response. The resulting response function predicts the wideband (~300-nm) response of the system to high precision. The performance of a spectral calibration device is also presented. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  19. Absolute and geometric parameters of contact binary BO Arietis

    NASA Astrophysics Data System (ADS)

    Gürol, B.; Gürsoytrak, S. H.; Bradstreet, D. H.

    2015-08-01

    We present the results of our investigation on the geometrical and physical parameters of the W UMa type binary system BO Ari from analyzed CCD (BVRI) light curves and radial velocity data. The photometric data were obtained in 2009 and 2010 at Ankara University Observatory (AUO) and the spectroscopic observations were made in 2007 and 2010 at TUBITAK National Observatory (TUG). These light and radial velocity observations were analyzed simultaneously by using the Wilson-Devinney (2013 revision) code to obtain absolute and geometrical parameters. The system was determined to be an A-type W UMa system. Combining our photometric solution with the spectroscopic data we derived masses and radii of the eclipsing system to be M1 = 0.995M?,M2 = 0.189M?,R1 = 1.090R? and R2 = 0.515R? . Finally, we discuss the evolutionary status of the system.

  20. Absolute properties of the triple star HP Aurigae

    SciTech Connect

    Lacy, Claud H. Sandberg; Burks, Charles L.; Torres, Guillermo; Wolf, Marek E-mail: clburks@email.uark.edu E-mail: wolf@cesnet.cz

    2014-01-01

    New photometric, spectroscopic, and eclipse timing observations of the eclipsing binary star HP Aur allow for very accurate orbital determinations, even in the presence of a third body and transient starspot activity. The eclipsing binary masses are determined to an accuracy of ±0.4% and the radii to ±0.6%. The masses are 0.9543 ± 0.0041 and 0.8094 ± 0.0036 solar masses, and the radii are 1.0278 ± 0.0042 and 0.7758 ± 0.0034 solar radii, respectively. The orbital period in the outer orbit is accurately determined for the first time: 4.332 ± 0.011 yr. A comparison with current theories of stellar evolution shows that the components' absolute properties can be well-matched by the current models at an age of about 7 billion years.

  1. Recent advances in absolute distance measurements using femtosecond light pulses

    NASA Astrophysics Data System (ADS)

    Kim, Seung-Woo; Kim, Young-Jin; Hyun, Sangwon; Chun, Byung Jae; Jang, Yoon-Soo

    2015-02-01

    Absolute distance measurement (ADM) with high precision is required for various fields of precision engineering, which has long been implemented by means of time-of-flight measurement of a pulsed laser, intensity or frequency modulation of a continuous-wave laser, and cross-correlation of pseudo-random micro-wave signals. Recently, in response to increasing demands on the measurement precision and range beyond conventional limits, femtosecond pulse lasers began to draw attention as a new light source that permits realizing various advanced ADM principles such as synthetic radiofrequency wavelength generation, Fourier-transform-based dispersive analysis and multi-wavelength interferometry. In this talk, we present the state-of-the-art measurement principles and performance demonstrated by exploiting the unique temporal and spectral characteristics of femtosecond laser pulses for high-precision ADM applications.

  2. Upgrade of absolute extreme ultraviolet diagnostic on J-TEXT

    SciTech Connect

    Zhang, X. L.; Cheng, Z. F. Hou, S. Y.; Zhuang, G.; Luo, J.

    2014-11-15

    The absolute extreme ultraviolet (AXUV) diagnostic system is used for radiation observation on J-TEXT tokamak [J. Zhang, G. Zhuang, Z. J. Wang, Y. H. Ding, X. Q. Zhang, and Y. J. Tang, Rev. Sci. Instrum. 81, 073509 (2010)]. The upgrade of the AXUV system is aimed to improve the spatial resolution and provide a three-dimensional image on J-TEXT. The new system consists of 12 AXUV arrays (4 AXUV16ELG arrays, 8 AXUV20ELG arrays). The spatial resolution in the cross-section is 21 mm for the AXUV16ELG arrays and 17 mm for the AXUV20ELG arrays. The pre-amplifier is also upgraded for a higher signal to noise ratio. By upgrading the AXUV imaging system, a more accurate observation on the radiation information is obtained.

  3. Absolute properties of the eclipsing binary star IM Persei

    SciTech Connect

    Lacy, Claud H. Sandberg; Torres, Guillermo; Fekel, Francis C.; Muterspaugh, Matthew W.; Southworth, John E-mail: gtorres@cfa.harvard.edu E-mail: matthew1@coe.tsuniv.edu

    2015-01-01

    IM Per is a detached A7 eccentric eclipsing binary star. We have obtained extensive measurements of the light curve (28,225 differential magnitude observations) and radial velocity curve (81 spectroscopic observations) which allow us to fit orbits and determine the absolute properties of the components very accurately: masses of 1.7831 ± 0.0094 and 1.7741 ± 0.0097 solar masses, and radii of 2.409 ± 0.018 and 2.366 ± 0.017 solar radii. The orbital period is 2.25422694(15) days and the eccentricity is 0.0473(26). A faint third component was detected in the analysis of the light curves, and also directly observed in the spectra. The observed rate of apsidal motion is consistent with theory (U = 151.4 ± 8.4 year). We determine a distance to the system of 566 ± 46 pc.

  4. Orion Exploration Flight Test-1 (EFT-1) Absolute Navigation Performance

    NASA Technical Reports Server (NTRS)

    Zanetti, Renato

    2015-01-01

    The Orion vehicle, being design to take men back to the Moon and beyond, successfully completed its first flight test, EFT-1 (Exploration Flight Test-1), on December 5th, 2014. The main objective of the test was to demonstrate the capability of re-enter into the Earth's atmosphere and safely splash-down into the pacific ocean. This un-crewed mission completes two orbits around Earth, the second of which is highly elliptical with an apogee of approximately 5908 km, higher than any vehicle designed for humans has been since the Apollo program. The trajectory was designed in order to test a high-energy re-entry similar to those crews will undergo during lunar missions. The mission overview is shown in Figure 1. The objective of this paper is to document the performance of the absolute navigation system during EFT-1 and to present its design.

  5. Total synthesis and absolute configuration of malyngamide W.

    PubMed

    Qi, Xian-Liang; Zhang, Jun-Tao; Feng, Jian-Peng; Cao, Xiao-Ping

    2011-05-21

    A concise enantioselective synthesis of malyngamide W (1) and its 2'-epimer was described. The strategy was based on three key steps: (1) ozonolysis of compound 11 which was derived from (R)-(-)-carvone 8, followed by copper-iron-catalyzed rearrangement to give the key cyclohex-2-enone intermediate 5, (2) Nozaki-Hiyama-Kishi coupling reaction between aldehyde 4 and iodide 14 to afford alcohol 3, and (3) asymmetric (R)-CBS reduction of the ketone functionality in compound 21 to establish the C-2' chiral center in the target compound 1. The absolute configuration of malyngamide W (1) was thus confirmed via the synthesis of 1 and 2'-epi-1. PMID:21445440

  6. THE ABSOLUTE CALIBRATION OF THE EUV IMAGING SPECTROMETER ON HINODE

    SciTech Connect

    Warren, Harry P.; Ugarte-Urra, Ignacio; Landi, Enrico

    2014-07-01

    We investigate the absolute calibration of the EUV Imaging Spectrometer (EIS) on Hinode by comparing EIS full-disk mosaics with irradiance observations from the EUV Variability Experiment on the Solar Dynamics Observatory. We also use extended observations of the quiet corona above the limb combined with a simple differential emission measure model to establish new effective area curves that incorporate information from the most recent atomic physics calculations. We find that changes to the EIS instrument sensitivity are a complex function of both time and wavelength. We find that the sensitivity is decaying exponentially with time and that the decay constants vary with wavelength. The EIS short wavelength channel shows significantly longer decay times than the long wavelength channel.

  7. Absolute Measurement Of Laminar Shear Rate Using Photon Correlation Spectroscopy

    E-print Network

    Elliot Jenner; Brian D'Urso

    2015-05-11

    An absolute measurement of the components of the shear rate tensor $\\mathcal{S}$ in a fluid can be found by measuring the photon correlation function of light scattered from particles in the fluid. Previous methods of measuring $\\mathcal{S}$ involve reading the velocity at various points and extrapolating the shear, which can be time consuming and is limited in its ability to examine small spatial scale or short time events. Previous work in Photon Correlation Spectroscopy has involved only approximate solutions, requiring free parameters to be scaled by a known case, or different cases, such as 2-D flows, but here we present a treatment that provides quantitative results directly and without calibration for full 3-D flow. We demonstrate this treatment experimentally with a cone and plate rheometer.

  8. Method and apparatus for making absolute range measurements

    DOEpatents

    Earl, Dennis D. (Knoxville, TN); Allison, Stephen W. (Knoxville, TN); Cates, Michael R. (Oak Ridge, TN); Sanders, Alvin J. (Knoxville, TN)

    2002-09-24

    This invention relates to a method and apparatus for making absolute distance or ranging measurements using Fresnel diffraction. The invention employs a source of electromagnetic radiation having a known wavelength or wavelength distribution, which sends a beam of electromagnetic radiation through a screen at least partially opaque at the wavelength. The screen has an aperture sized so as to produce a Fresnel diffraction pattern. A portion of the beam travels through the aperture to a detector spaced some distance from the screen. The detector detects the central intensity of the beam as well as a set of intensities displaced from a center of the aperture. The distance from the source to the target can then be calculated based upon the known wavelength, aperture radius, and beam intensity.

  9. Early results from the Far Infrared Absolute Spectrophotometer (FIRAS)

    NASA Technical Reports Server (NTRS)

    Mather, J. C.; Cheng, E. S.; Shafer, R. A.; Eplee, R. E.; Isaacman, R. B.; Fixsen, D. J.; Read, S. M.; Meyer, S. S.; Weiss, R.; Wright, E. L.

    1991-01-01

    The Far Infrared Absolute Spectrophotometer (FIRAS) on the Cosmic Background Explorer (COBE) mapped 98 percent of the sky, 60 percent of it twice, before the liquid helium coolant was exhausted. The FIRAS covers the frequency region from 1 to 100/cm with a 7 deg angular resolution. The spectral resolution is 0.2/cm for frequencies less than 20/cm and 0.8/cm for higher frequencies. Preliminary results include: a limit on the deviations from a Planck curve of 1 percent of the peak brightness from 1 to 20/cm, a temperature of 2.735 +/- 0.06 K, a limit on the Comptonization parameter y of 0.001, on the chemical potential parameter mu of 0.01, a strong limit on the existence of a hot smooth intergalactic medium, and a confirmation that the dipole anisotropy spectrum is that of a Doppler shifted blackbody.

  10. Absolute stress measurements at the rangely anticline, Northwestern Colorado

    USGS Publications Warehouse

    de la Cruz, R. V.; Raleigh, C.B.

    1972-01-01

    Five different methods of measuring absolute state of stress in rocks in situ were used at sites near Rangely, Colorado, and the results compared. For near-surface measurements, overcoring of the borehole-deformation gage is the most convenient and rapid means of obtaining reliable values for the magnitude and direction of the state of stress in rocks in situ. The magnitudes and directions of the principal stresses are compared to the geologic features of the different areas of measurement. The in situ stresses are consistent in orientation with the stress direction inferred from the earthquake focal-plane solutions and existing joint patterns but inconsistent with stress directions likely to have produced the Rangely anticline. ?? 1972.

  11. Biochip Image Grid Normalization Absolute Signal Fluorescence Measurement Using

    Energy Science and Technology Software Center (ESTSC)

    2001-04-17

    This software was developed to measure absolute fluorescent intensities of gel pads on a microchip in units defined by a standard fluorescent slide. It can accomodate varying measurement conditions (e.g. exposure time, sensitivity of detector, resolution of detector, etc.) as well as fluorescent microscopes with non-uniform sensitivity across their field of view allowing the user to compare measurements done on different detectors with varying exposure times, sensitivities, and resolutions. The software is designed both tomore »operate Roper Scientific, Inc. cameras and to use image files produced by the program supplied with that equipment for its calculations. the intensity of the gel pad signal is computed so as to reduce background influence.« less

  12. State estimation and absolute image registration for geosynchronous satellites

    NASA Technical Reports Server (NTRS)

    Nankervis, R.; Koch, D. W.; Sielski, H.

    1980-01-01

    Spacecraft state estimation and the absolute registration of Earth images acquired by cameras onboard geosynchronous satellites are described. The basic data type of the procedure consists of line and element numbers of image points called landmarks whose geodetic coordinates, relative to United States Geodetic Survey topographic maps, are known. A conventional least squares process is used to estimate navigational parameters and camera pointing biases from observed minus computed landmark line and element numbers. These estimated parameters along with orbit and attitude dynamic models are used to register images, using an automated grey level correlation technique, inside the span represented by the landmark data. In addition, the dynamic models can be employed to register images outside of the data span in a near real time mode. An important application of this mode is in support of meteorological studies where rapid data reduction is required for the rapid tracking and predicting of dynamic phenomena.

  13. Absolute interferometric test of cylindrical wavefront with a fiber optic

    NASA Astrophysics Data System (ADS)

    Alatawi, Ayshah; Reardon, Patrick J.

    2014-11-01

    A method of absolute testing of a cylindrical wavefront is presented. The method is a merging of the random ball test method with the fiber optic reference test. The random ball test assumes a large number of interferograms of a good quality sphere with errors that are statistically distributed such that the average of the errors goes to zero. The fiber optic reference test utilizes a specially processed optical fiber to provide a high quality reference wave from an incident line focus from the cylindrical wave under test. A simulation and preliminary experiment results are presented which indicate that this method can significantly reduce the effects of fiber surface errors, yielding more accurate cylindrical wave measurements.

  14. Absolute Position Total Internal Reflection Microscopy with an Optical Tweezer

    E-print Network

    Liu, Lulu; Rodriguez, Alejandro W; Capasso, Federico

    2014-01-01

    A non-invasive, in-situ calibration method for Total Internal Reflection Microscopy (TIRM) based on optical tweezing is presented which greatly expands the capabilities of this technique. We show that by making only simple modifications to the basic TIRM sensing setup and procedure, a probe particle's absolute position relative to a dielectric interface may be known with better than 10 nm precision out to a distance greater than 1 $\\mu$m from the surface. This represents an approximate 10x improvement in error and 3x improvement in measurement range over conventional TIRM methods. The technique's advantage is in the direct measurement of the probe particle's scattering intensity vs. height profile in-situ, rather than relying on calculations or inexact system analogs for calibration. To demonstrate the improved versatility of the TIRM method in terms of tunability, precision, and range, we show our results for the hindered near-wall diffusion coefficient for a spherical dielectric particle.

  15. Absolute Measurement of Tilts via Fourier Analysis of Interferograms

    NASA Technical Reports Server (NTRS)

    Toland, Ronald W.

    2004-01-01

    The Fourier method of interferogram analysis requires the introduction of a constant tilt into the interferogram to serve as a carrier signal for information on the figure of the surface under test. This tilt is usually removed in the first steps of analysis and ignored thereafter. However, in the problem of aligning optical components and systems, knowledge of part orientation is crucial to proper instrument performance. This paper outlines an algorithm which uses the normally ignored carrier signal in Fourier analysis to compute an absolute tilt (orientation) of the test surface. We also provide a brief outline of how this technique, incorporated in a rotating Twyman-Green interferometer, can be used in alignment and metrology of optical systems.

  16. Absolute Measurement of Tilts via Fourier Analysis of Interferograms

    NASA Technical Reports Server (NTRS)

    Toland, Ronald W.

    2004-01-01

    The Fourier method of interferogram analysis requires the introduction of a constant tilt into the inteferogram to serve as a 'carrier signal' for information on the figure of the surface under test. This tilt is usually removed in the first steps of analysis and ignored thereafter. However, in the problem of aligning optical components and systems, knowledge of part orientation is crucial to proper instrument performance. This paper outlines an algorithm which uses the normally ignored carrier signal in Fourier analysis to compute an absolute tilt (orientation) of the test surface. We also provide a brief outline of how this technique, incorporated in a rotating Twyman-Green interferometer, can be used in alignment and metrology of optical systems.

  17. Development of a Monochromatic Neutron Beam for Absolute Neutron Measurements.

    NASA Astrophysics Data System (ADS)

    Chowdhuri, Z.; Jones, G. L.; Snow, W. M.; Adams, J. M.; Arif, M.; Dewey, M. S.; Jacobson, D. L.; Nico, J. S.; Thompson, A. K.; Wietfeldt, F. E.

    1998-10-01

    We describe the design and characteristics of a new monochromatic neutron beam recently established at the end of neutron guide NG-6 at the National Center for Neutron Research at NIST. Results from an accurate absolute measurement of the mean neutron wavelength of this beam will be presented. In addition, we will discuss our plans for accurate neutron flux measurements^1,2 which are required for a Penning trap-based neutron lifetime experiment in progress at NIST^3. ^1 D. M. Gilliam, G. L. Greene, and G. P. Lamaze, NIM A284, 220 (1989) ^2 J. M. Richardson, T. E. Chupp, R. G. H. Robertson, and J. F. Wilkerson, NIM A306, 291 (1991) ^3 W. M. Snow, M. S. Dewey, D. M. Gilliam, and G. L. Greene, Proceedings of WEIN-95, ed. H. Ejiri, World Scientific, 346-349 (1996)

  18. A three-axis SQUID-based absolute vector magnetometer.

    PubMed

    Schönau, T; Zakosarenko, V; Schmelz, M; Stolz, R; Anders, S; Linzen, S; Meyer, M; Meyer, H-G

    2015-10-01

    We report on the development of a three-axis absolute vector magnetometer suited for mobile operation in the Earth's magnetic field. It is based on low critical temperature dc superconducting quantum interference devices (LTS dc SQUIDs) with sub-micrometer sized cross-type Josephson junctions and exhibits a white noise level of about 10 fT/Hz(1/2). The width of superconducting strip lines is restricted to less than 6 ?m in order to avoid flux trapping during cool-down in magnetically unshielded environment. The long-term stability of the flux-to-voltage transfer coefficients of the SQUID electronics is investigated in detail and a method is presented to significantly increase their reproducibility. We further demonstrate the long-term operation of the setup in a magnetic field varying by about 200 ?T amplitude without the need for recalibration. PMID:26520976

  19. A three-axis SQUID-based absolute vector magnetometer

    NASA Astrophysics Data System (ADS)

    Schönau, T.; Zakosarenko, V.; Schmelz, M.; Stolz, R.; Anders, S.; Linzen, S.; Meyer, M.; Meyer, H.-G.

    2015-10-01

    We report on the development of a three-axis absolute vector magnetometer suited for mobile operation in the Earth's magnetic field. It is based on low critical temperature dc superconducting quantum interference devices (LTS dc SQUIDs) with sub-micrometer sized cross-type Josephson junctions and exhibits a white noise level of about 10 fT/Hz1/2. The width of superconducting strip lines is restricted to less than 6 ?m in order to avoid flux trapping during cool-down in magnetically unshielded environment. The long-term stability of the flux-to-voltage transfer coefficients of the SQUID electronics is investigated in detail and a method is presented to significantly increase their reproducibility. We further demonstrate the long-term operation of the setup in a magnetic field varying by about 200 ?T amplitude without the need for recalibration.

  20. Measurements of absolute hadronic branching fractions of $?_{c}^{+}$ baryon

    E-print Network

    BESIII Collaboration; M. Ablikim; M. N. Achasov; X. C. Ai; O. Albayrak; M. Albrecht; D. J. Ambrose; A. Amoroso; F. F. An; Q. An; J. Z. Bai; R. Baldini Ferroli; Y. Ban; D. W. Bennett; J. V. Bennett; M. Bertani; D. Bettoni; J. M. Bian; F. Bianchi; E. Boger; I. Boyko; R. A. Briere; H. Cai; X. Cai; O. Cakir; A. Calcaterra; G. F. Cao; S. A. Cetin; J. F. Chang; G. Chelkov; G. Chen; H. S. Chen; H. Y. Chen; J. C. Chen; M. L. Chen; S. J. Chen; X. Chen; X. R. Chen; Y. B. Chen; H. P. Cheng; X. K. Chu; G. Cibinetto; H. L. Dai; J. P. Dai; A. Dbeyssi; D. Dedovich; Z. Y. Deng; A. Denig; I. Denysenko; M. Destefanis; F. De Mori; Y. Ding; C. Dong; J. Dong; L. Y. Dong; M. Y. Dong; Z. L. Dou; S. X. Du; P. F. Duan; E. E. Eren; J. Z. Fan; J. Fang; S. S. Fang; X. Fang; Y. Fang; R. Farinelli; L. Fava; O. Fedorov; F. Feldbauer; G. Felici; C. Q. Feng; E. Fioravanti; M. Fritsch; C. D. Fu; Q. Gao; X. L. Gao; X. Y. Gao; Y. Gao; Z. Gao; I. Garzia; K. Goetzen; L. Gong; W. X. Gong; W. Gradl; M. Greco; M. H. Gu; Y. T. Gu; Y. H. Guan; A. Q. Guo; L. B. Guo; Y. Guo; Y. P. Guo; Z. Haddadi; A. Hafner; S. Han; X. Q. Hao; F. A. Harris; K. L. He; T. Held; Y. K. Heng; Z. L. Hou; C. Hu; H. M. Hu; J. F. Hu; T. Hu; Y. Hu; G. S. Huang; J. S. Huang; X. T. Huang; Y. Huang; T. Hussain; Q. Ji; Q. P. Ji; X. B. Ji; X. L. Ji; L. W. Jiang; X. S. Jiang; X. Y. Jiang; J. B. Jiao; Z. Jiao; D. P. Jin; S. Jin; T. Johansson; A. Julin; N. Kalantar-Nayestanaki; X. L. Kang; X. S. Kang; M. Kavatsyuk; B. C. Ke; P. Kiese; R. Kliemt; B. Kloss; O. B. Kolcu; B. Kopf; M. Kornicer; W. Kuehn; A. Kupsc; J. S. Lange; M. Lara; P. Larin; C. Leng; C. Li; Cheng Li; D. M. Li; F. Li; F. Y. Li; G. Li; H. B. Li; J. C. Li; Jin Li; K. Li; K. Li; Lei Li; P. R. Li; Q. Y. Li; T. Li; W. D. Li; W. G. Li; X. L. Li; X. M. Li; X. N. Li; X. Q. Li; Z. B. Li; H. Liang; Y. F. Liang; Y. T. Liang; G. R. Liao; D. X. Lin; B. J. Liu; C. X. Liu; D. Liu; F. H. Liu; Fang Liu; Feng Liu; H. B. Liu; H. H. Liu; H. H. Liu; H. M. Liu; J. Liu; J. B. Liu; J. P. Liu; J. Y. Liu; K. Liu; K. Y. Liu; L. D. Liu; P. L. Liu; Q. Liu; S. B. Liu; X. Liu; Y. B. Liu; Z. A. Liu; Zhiqing Liu; H. Loehner; X. C. Lou; H. J. Lu; J. G. Lu; Y. Lu; Y. P. Lu; C. L. Luo; M. X. Luo; T. Luo; X. L. Luo; X. R. Lyu; F. C. Ma; H. L. Ma; L. L. Ma; Q. M. Ma; T. Ma; X. N. Ma; X. Y. Ma; Y. M. Ma; F. E. Maas; M. Maggiora; Y. J. Mao; Z. P. Mao; S. Marcello; J. G. Messchendorp; J. Min; R. E. Mitchell; X. H. Mo; Y. J. Mo; C. Morales Morales; N. Yu. Muchnoi; H. Muramatsu; Y. Nefedov; F. Nerling; I. B. Nikolaev; Z. Ning; S. Nisar; S. L. Niu; X. Y. Niu; S. L. Olsen; Q. Ouyang; S. Pacetti; Y. Pan; P. Patteri; M. Pelizaeus; H. P. Peng; K. Peters; J. Pettersson; J. L. Ping; R. G. Ping; R. Poling; V. Prasad; H. R. Qi; M. Qi; S. Qian; C. F. Qiao; L. Q. Qin; N. Qin; X. S. Qin; Z. H. Qin; J. F. Qiu; K. H. Rashid; C. F. Redmer; M. Ripka; G. Rong; Ch. Rosner; X. D. Ruan; V. Santoro; A. Sarantsev; M. Savrié; K. Schoenning; S. Schumann; W. Shan; M. Shao; C. P. Shen; P. X. Shen; X. Y. Shen; H. Y. Sheng; W. M. Song; X. Y. Song; S. Sosio; S. Spataro; G. X. Sun; J. F. Sun; S. S. Sun; Y. J. Sun; Y. Z. Sun; Z. J. Sun; Z. T. Sun; C. J. Tang; X. Tang; I. Tapan; E. H. Thorndike; M. Tiemens; M. Ullrich; I. Uman; G. S. Varner; B. Wang; B. L. Wang; D. Wang; D. Y. Wang; K. Wang; L. L. Wang; L. S. Wang; M. Wang; P. Wang; P. L. Wang; S. G. Wang; W. Wang; W. P. Wang; X. F. Wang; Y. D. Wang; Y. F. Wang; Y. Q. Wang; Z. Wang; Z. G. Wang; Z. H. Wang; Z. Y. Wang; T. Weber; D. H. Wei; J. B. Wei; P. Weidenkaff; S. P. Wen; U. Wiedner; M. Wolke; L. H. Wu; Z. Wu; L. Xia; L. G. Xia; Y. Xia; D. Xiao; H. Xiao; Z. J. Xiao; Y. G. Xie; Q. L. Xiu; G. F. Xu; L. Xu; Q. J. Xu; Q. N. Xu; X. P. Xu; L. Yan; W. B. Yan; W. C. Yan; Y. H. Yan; H. J. Yang; H. X. Yang; L. Yang; Y. X. Yang; M. Ye; M. H. Ye; J. H. Yin; B. X. Yu; C. X. Yu; J. S. Yu; C. Z. Yuan; W. L. Yuan; Y. Yuan; A. Yuncu; A. A. Zafar; A. Zallo; Y. Zeng; Z. Zeng; B. X. Zhang; B. Y. Zhang; C. Zhang; C. C. Zhang; D. H. Zhang; H. H. Zhang; H. Y. Zhang; J. J. Zhang; J. L. Zhang; J. Q. Zhang; J. W. Zhang; J. Y. Zhang; J. Z. Zhang; K. Zhang; L. Zhang; X. Y. Zhang; Y. Zhang; Y. H. Zhang; Y. N. Zhang; Y. T. Zhang; Yu Zhang; Z. H. Zhang; Z. P. Zhang; Z. Y. Zhang; G. Zhao; J. W. Zhao; J. Y. Zhao; J. Z. Zhao; Lei Zhao; Ling Zhao; M. G. Zhao; Q. Zhao; Q. W. Zhao; S. J. Zhao; T. C. Zhao; Y. B. Zhao; Z. G. Zhao; A. Zhemchugov; B. Zheng; J. P. Zheng; W. J. Zheng; Y. H. Zheng; B. Zhong; L. Zhou; X. Zhou; X. K. Zhou; X. R. Zhou; X. Y. Zhou; K. Zhu; K. J. Zhu; S. Zhu; S. H. Zhu; X. L. Zhu; Y. C. Zhu; Y. S. Zhu; Z. A. Zhu; J. Zhuang; L. Zotti; B. S. Zou; J. H. Zou

    2015-11-26

    Using $567\\rm{pb}^{-1}$ of $e^+e^-$ collisions recorded at $\\sqrt{s}=4.599\\rm{GeV}$ with the BESIII detector, we report first measurements of absolute hadronic branching fractions of Cabibbo-favored decays of the $\\Lambda_{c}^{+}$ baryon with a double-tag technique. A global least-square fitter is utilized to improve the measured precision. Among the measurements for twelve $\\Lambda_{c}^{+}$ decay modes, the branching fraction for $\\Lambda_{c}^{+} \\rightarrow pK^-\\pi^+$ is determined to be $(5.84\\pm0.27\\pm0.23)\\%$, where the first uncertainty is statistical and the second is systematic. In addition, the measurements of the branching fractions of the other eleven Cabbibo-favored hadronic decay modes are significantly improved.

  1. Full field imaging based instantaneous hyperspectral absolute refractive index measurement

    SciTech Connect

    Baba, Justin S; Boudreaux, Philip R

    2012-01-01

    Multispectral refractometers typically measure refractive index (RI) at discrete monochromatic wavelengths via a serial process. We report on the demonstration of a white light full field imaging based refractometer capable of instantaneous multispectral measurement of absolute RI of clear liquid/gel samples across the entire visible light spectrum. The broad optical bandwidth refractometer is capable of hyperspectral measurement of RI in the range 1.30 1.70 between 400nm 700nm with a maximum error of 0.0036 units (0.24% of actual) at 414nm for a = 1.50 sample. We present system design and calibration method details as well as results from a system validation sample.

  2. Absolute Radiation Measurements in Earth and Mars Entry Conditions

    NASA Technical Reports Server (NTRS)

    Cruden, Brett A.

    2014-01-01

    This paper reports on the measurement of radiative heating for shock heated flows which simulate conditions for Mars and Earth entries. Radiation measurements are made in NASA Ames' Electric Arc Shock Tube at velocities from 3-15 km/s in mixtures of N2/O2 and CO2/N2/Ar. The technique and limitations of the measurement are summarized in some detail. The absolute measurements will be discussed in regards to spectral features, radiative magnitude and spatiotemporal trends. Via analysis of spectra it is possible to extract properties such as electron density, and rotational, vibrational and electronic temperatures. Relaxation behind the shock is analyzed to determine how these properties relax to equilibrium and are used to validate and refine kinetic models. It is found that, for some conditions, some of these values diverge from non-equilibrium indicating a lack of similarity between the shock tube and free flight conditions. Possible reasons for this are discussed.

  3. The Swarm Absolute Scalar Magnetometer Magnetic Cleanliness Program

    NASA Astrophysics Data System (ADS)

    Alcouffe, F.; Bertrand, F.; Jager, T.; Le Prado, M.; Léger, J.-M.; Fratter, I.

    2012-05-01

    The Swarm mission selected by the European Space Agency (ESA) as the 3rd Opportunity mission of the Earth Explorer Program will operate a constellation of three satellites dedicated to the most advanced survey of the Earth's magnetic field and its temporal evolution. The magnetic payload aboard each satellite will consist of a Vector Field Magnetometer (VFM) developed by the Danish National Space Center and an Absolute Scalar Magnetometer (ASM) [1] developed by CEA- LETI in partnership with CNES. This instrument shall provide scalar measurements of the magnetic field for the calibration of the fluxgate vector instrument. As a consequence, its accuracy is crucial for the mission's success, and all the parameters affecting it have been consequently thoroughly investigated. This paper focuses on the magnetic cleanliness program that has been implemented throughout the ASM development phases to guarantee its conformity with the performance requirements, from the instrument's design and manufacture to its final qualification tests.

  4. Absolute stellar photometry on moderate-resolution FPA images

    USGS Publications Warehouse

    Stone, T.C.

    2009-01-01

    An extensive database of star (and Moon) images has been collected by the ground-based RObotic Lunar Observatory (ROLO) as part of the US Geological Survey program for lunar calibration. The stellar data are used to derive nightly atmospheric corrections for the observations from extinction measurements, and absolute calibration of the ROLO sensors is based on observations of Vega and published reference flux and spectrum data. The ROLO telescopes were designed for imaging the Moon at moderate resolution, thus imposing some limitations for the stellar photometry. Attaining accurate stellar photometry with the ROLO image data has required development of specialized processing techniques. A key consideration is consistency in discriminating the star core signal from the off-axis point spread function. The analysis and processing methods applied to the ROLO stellar image database are described. ?? 2009 BIPM and IOP Publishing Ltd.

  5. Upgrade of absolute extreme ultraviolet diagnostic on J-TEXTa)

    NASA Astrophysics Data System (ADS)

    Zhang, X. L.; Cheng, Z. F.; Hou, S. Y.; Zhuang, G.; Luo, J.

    2014-11-01

    The absolute extreme ultraviolet (AXUV) diagnostic system is used for radiation observation on J-TEXT tokamak [J. Zhang, G. Zhuang, Z. J. Wang, Y. H. Ding, X. Q. Zhang, and Y. J. Tang, Rev. Sci. Instrum. 81, 073509 (2010)]. The upgrade of the AXUV system is aimed to improve the spatial resolution and provide a three-dimensional image on J-TEXT. The new system consists of 12 AXUV arrays (4 AXUV16ELG arrays, 8 AXUV20ELG arrays). The spatial resolution in the cross-section is 21 mm for the AXUV16ELG arrays and 17 mm for the AXUV20ELG arrays. The pre-amplifier is also upgraded for a higher signal to noise ratio. By upgrading the AXUV imaging system, a more accurate observation on the radiation information is obtained.

  6. SPRED spectrograph upgrade: high resolution grating and improved absolute calibrations

    SciTech Connect

    Stratton, B.C.; Fonck, R.J.; Ida, K.; Jaehnig, K.P.; Ramsey, A.T.

    1986-05-01

    Two improvements to the SPRED multichannel VUV spectrographs used on the TFTR and PBX tokamaks have been made: (1) A new 2100-g/mm grating covering the 100 to 320 A region with 0.4 A resolution (FWHM) has been added to the existing 450 g/mm grating (100 to 1100 A with 2 A resolution), and (2) the TFTR SPRED has been absolutely calibrated using synchrotron radiation from the NBS SURF II facility, while the PBX system has been calibrated using conventional branching ratios along with line ratios from charge-exchange-recombination-excited lines. The availability of high resolution spectra in the 100 to 320 A range provides improved measurements of metallic ion emissions and, when the instrument views across a neutral beam as in PBX, allows carbon and oxygen densities to be measured via charge exchange recombination spectroscopy.

  7. ABSOLUTE PROPERTIES OF THE ECLIPSING BINARY STAR V335 SERPENTIS

    SciTech Connect

    Lacy, Claud H. Sandberg; Fekel, Francis C.; Claret, Antonio E-mail: fekel@evans.tsuniv.edu

    2012-08-15

    V335 Ser is now known to be an eccentric double-lined A1+A3 binary star with fairly deep (0.5 mag) partial eclipses. Previous studies of the system are improved with 7456 differential photometric observations from the URSA WebScope and 5666 from the NFO WebScope, and 67 high-resolution spectroscopic observations from the Tennessee State University 2 m automatic spectroscopic telescope. From dates of minima, the apsidal period is about 880 years. Accurate (better than 2%) masses and radii are determined from analysis of the two new light curves and the radial velocity curve. Theoretical models match the absolute properties of the stars at an age of about 380 Myr, though the age agreement for the two components is poor. Tidal theory correctly confirms that the orbit should still be eccentric, but we find that standard tidal theory is unable to match the observed asynchronous rotation rates of the components' surface layers.

  8. ABSOLUTE PROPERTIES OF THE ECLIPSING BINARY STAR HY VIRGINIS

    SciTech Connect

    Sandberg Lacy, Claud H.; Fekel, Francis C. E-mail: fekel@evans.tsuniv.edu

    2011-12-15

    HY Vir is found to be a double-lined F0m+F5 binary star with relatively shallow (0.3 mag) partial eclipses. Previous studies of the system are improved with 7509 differential photometric observations from the URSA WebScope and 8862 from the NFO WebScope, and 68 high-resolution spectroscopic observations from the Tennessee State University 2 m automatic spectroscopic telescope, and the 1 m coude-feed spectrometer at Kitt Peak National Observatory. Very accurate (better than 0.5%) masses and radii are determined from analysis of the new light curves and radial velocity curves. Theoretical models match the absolute properties of the stars at an age of about 1.35 Gy.

  9. Lunar eclipse photometry: absolute luminance measurements and modeling.

    PubMed

    Hernitschek, Nina; Schmidt, Elmar; Vollmer, Michael

    2008-12-01

    The Moon's time-dependent luminance was determined during the 9 February 1990 and 3 March 2007 total lunar eclipses by using calibrated, industry standard photometers. After the results were corrected to unit air mass and to standard distances for both Moon and Sun, an absolute calibration was accomplished by using the Sun's known luminance and a pre-eclipse lunar albedo of approximately 13.5%. The measured minimum level of brightness in the total phase of both eclipses was relatively high, namely -3.32 m(vis) and -1.7 m(vis), which hints at the absence of pronounced stratospheric aerosol. The light curves were modeled in such a way as to let the Moon move through an artificial Earth shadow composed of a multitude of disk and ring zones, containing a relative luminance data set from an atmospheric radiative transfer calculation. PMID:19037352

  10. ABSOLUTE PROPERTIES OF THE TRIPLE STAR CF TAURI

    SciTech Connect

    Lacy, Claud H. Sandberg; Torres, Guillermo; Claret, Antonio E-mail: gtorres@cfa.harvard.edu

    2012-12-01

    CF Tau is now known to be an eclipsing triple star with relatively deep total and annular eclipses. New light and radial velocity curves as well as new times of minima were obtained and used for further modeling of the system. Very accurate (better than 0.9%) masses and radii of the eclipsing pair are determined from analysis of the two new light curves, the radial velocity curve, and the times of minimum light. The mass and luminosity of the distant third component is accurately determined as well. Theoretical models of the detached, evolved eclipsing pair match the observed absolute properties of the stars at an age of about 4.3 Gyr and [Fe/H] = -0.14.

  11. Ensuring long-term stability of infrared camera absolute calibration.

    PubMed

    Kattnig, Alain; Thetas, Sophie; Primot, Jérôme

    2015-07-13

    Absolute calibration of cryogenic 3-5 µm and 8-10 µm infrared cameras is notoriously instable and thus has to be repeated before actual measurements. Moreover, the signal to noise ratio of the imagery is lowered, decreasing its quality. These performances degradations strongly lessen the suitability of Infrared Imaging. These defaults are often blamed on detectors reaching a different "response state" after each return to cryogenic conditions, while accounting for the detrimental effects of imperfect stray light management. We show here that detectors are not to be blamed and that the culprit can also dwell in proximity electronics. We identify an unexpected source of instability in the initial voltage of the integrating capacity of detectors. Then we show that this parameter can be easily measured and taken into account. This way we demonstrate that a one month old calibration of a 3-5 µm camera has retained its validity. PMID:26191896

  12. Absolute measurements of chlorine Cl+ cation single photoionization cross section

    NASA Astrophysics Data System (ADS)

    Hernández, E. M.; Juárez, A. M.; Kilcoyne, A. L. D.; Aguilar, A.; Hernández, L.; Antillón, A.; Macaluso, D.; Morales-Mori, A.; González-Magaña, O.; Hanstorp, D.; Covington, A. M.; Davis, V.; Calabrese, D.; Hinojosa, G.

    2015-01-01

    The photoionization of Cl+ leading to Cl2+ was measured in the photon energy range of 19.5-28.0 eV. A spectrum with a photon energy resolution of 15 meV normalized to absolute cross-section measurements is presented. The measurements were carried out by merging a Cl+ ion beam with a photon beam of highly monochromatic synchrotron radiation at the Advanced Light Source at Lawrence Berkeley National Laboratory. The measured photoionization of Cl+ consists of several autoionization resonances surperimposed on the direct photoionization signal. Most of the prominent resonances are assigned to members of Rydberg series originating from the singlet ground state and from metastable triplet levels within the ground-state configuration of Cl+. The direct ionization cross section is no larger than 12 Mb.

  13. Absolute parameters of young stars: GG Lup and ?1 Sco

    NASA Astrophysics Data System (ADS)

    Budding, E.; Butland, R.; Blackford, M.

    2015-04-01

    New high-resolution spectroscopy and BVR photometry, together with literature data, on the Gould's Belt close binary systems GG Lup and ?1 Sco are presented and analysed. In the case of GG Lup, light and radial velocity curve fittings confirm a near-main-sequence picture of a pair of close stars. Absolute parameters are found, to within a few per cent, thus: M1 = 4.16 ± 0.12, M2 = 2.64 ± 0.12 (M?); R1 = 2.42 ± 0.05, R2 = 1.79 ± 0.04 (R?); T1 ˜ 13 000, T2 ˜ 10 600 (K); photometric distance ˜160 (pc). The high eccentricity and relatively short period (105 yr) of apsidal revolution may be related to an apparent `slow B-type pulsator' oscillation. Disturbances of the outer envelope of at least one of the components then compromise comparisons to standard evolutionary models, at least regarding the age of the system. A rate of apsidal advance is derived, which allows a check on the mean internal structure constant overline{k_2} = 0.0058 ± 0.0004. This is in agreement with values recently derived for young stars of solar composition and mass ˜3 M?. For ?1 Sco, we agree with previous authors that the secondary component is considerably oversized for its mass, implying binary (interactive) stellar evolution, probably of the `Case A' type. The primary appears relatively little affected by this evolution, however. Its parameters show consistency with a star of its derived mass at age about 13 Myr, consistent with the star's membership of the Sco-Cen OB2 Association. The absolute parameters are as follows: M1 = 8.3 ± 1.0, M2 = 4.6 ± 1.0 (M?); R1 = 3.9 ± 0.3, R2 = 4.6 ± 0.4 (R?); T1 ˜ 24 000, T2 ˜ 17 000 (K); photometric distance ˜135 (pc).

  14. Cylindrical Taylor states conserving total absolute magnetic helicity

    NASA Astrophysics Data System (ADS)

    Low, B. C.; Fang, F.

    2014-09-01

    The Taylor state of a three-dimensional (3D) magnetic field in an upright cylindrical domain V is derived from first principles as an extremum of the total magnetic energy subject to a conserved, total absolute helicity Habs. This new helicity [Low, Phys. Plasmas 18, 052901 (2011)] is distinct from the well known classical total helicity and relative total helicity in common use to describe wholly-contained and anchored fields, respectively. A given field B, tangential along the cylindrical side of V, may be represented as a unique linear superposition of two flux systems, an axially extended system along V and a strictly transverse system carrying information on field-circulation. This specialized Chandrasekhar-Kendall representation defines Habs and permits a neat formulation of the boundary-value problem (BVP) for the Taylor state as a constant-? force-free field, treating 3D wholly-contained and anchored fields on the same conceptual basis. In this formulation, the governing equation is a scalar integro-partial differential equation (PDE). A family of series solutions for an anchored field is presented as an illustration of this class of BVPs. Past treatments of the constant-? field in 3D cylindrical geometry are based on a scalar Helmholtz PDE as the governing equation, with issues of inconsistency in the published field solutions discussed over time in the journal literature. The constant-? force-free equation reduces to a scalar Helmholtz PDE only as special cases of the 3D integro-PDE derived here. In contrast, the constant-? force-free equation and the scalar Helmholtz PDE are absolutely equivalent in the spherical domain as discussed in Appendix. This theoretical study is motivated by the investigation of the Sun's corona but the results are also relevant to laboratory plasmas.

  15. Updated Absolute Flux Calibration of the COS FUV Modes

    NASA Astrophysics Data System (ADS)

    Massa, D.; Ely, J.; Osten, R.; Penton, S.; Aloisi, A.; Bostroem, A.; Roman-Duval, J.; Proffitt, C.

    2014-03-01

    We present newly derived point source absolute flux calibrations for the COS FUV modes at both the original and second lifetime positions. The analysis includes observa- tions through the Primary Science Aperture (PSA) of the standard stars WD0308-565, GD71, WD1057+729 and WD0947+857 obtained as part of two calibration programs. Data were were obtained for all of the gratings at all of the original CENWAVE settings at both the original and second lifetime positions and for the G130M CENWAVE = 1222 at the second lifetime position. Data were also obtained with the FUVB segment for the G130M CENWAVE = 1055 and 1096 setting at the second lifetime position. We also present the derivation of L-flats that were used in processing the data and show that the internal consistency of the primary standards is 1%. The accuracy of the absolute flux calibrations over the UV are estimated to be 1-2% for the medium resolution gratings, and 2-3% over most of the wavelength range of the G140L grating, although the uncertainty can be as large as 5% or more at some G140L wavelengths. We note that these errors are all relative to the optical flux near the V band and small additional errors may be present due to inaccuracies in the V band calibration. In addition, these error estimates are for the time at which the flux calibration data were obtained; the accuracy of the flux calibration at other times can be affected by errors in the time dependent sensitivity (TDS) correction.

  16. New Reference Models for Pacific Absolute Plate Motion

    NASA Astrophysics Data System (ADS)

    Wessel, P.

    2012-12-01

    Absolute plate motion (APM) models are commonly derived by assuming that age-progressive seamount chains represent the surface expressions of mantle plumes; the chain geometries thus record the relative motion between plumes and plates. Traditionally, plumes have been assigned zero motion (i.e., the fixed hotspot hypothesis), and with this assumption the trails directly reflect plate motion. However, since the early 1970s arguments from sedimentary facies and marine magnetics have been marshaled against the fixity of hotspots, perhaps culminating with more recent and direct inferences of anomalous paleolatitudes for several seamounts in both the Emperor and Louisville chains. These data can broadly be explained by drifting plumes, but paleomagnetic data remain scarce and may allow for some true polar wander; furthermore, several age progressions are incomplete or inconsistent and the present locations of some hotspots are uncertain. Finally, APM models with moving hotspots derive largely from mantle flow modeling whose predictions do not match observations directly. Here, I present new absolute plate motion models for the Pacific plate back to 150 Ma. The first model assumes fixed hotspots and is meant to serve as a reference model representing the classic fixed hotspot hypothesis. It is an updated version of the Wessel and Kroenke [2008] model but now including all available chains, recently published age data and processed using improved modeling techniques. The second model uses the same data but also attempts to honor available data on hotspot mobility. It is intended to be a "work in progress" model that will be updated as additional paleolatitude or age data become available. These models can serve as test beds for tectonic hypothesis and be used to identify seamount chain segments where additional paleomagnetic or age observations would have the most impact.

  17. THE ABSOLUTE MAGNITUDE OF RRc VARIABLES FROM STATISTICAL PARALLAX

    SciTech Connect

    Kollmeier, Juna A.; Burns, Christopher R.; Thompson, Ian B.; Preston, George W.; Crane, Jeffrey D.; Madore, Barry F.; Morrell, Nidia; Prieto, José L.; Shectman, Stephen; Simon, Joshua D.; Villanueva, Edward; Szczygie?, Dorota M.; Gould, Andrew; Sneden, Christopher; Dong, Subo

    2013-09-20

    We present the first definitive measurement of the absolute magnitude of RR Lyrae c-type variable stars (RRc) determined purely from statistical parallax. We use a sample of 242 RRc variables selected from the All Sky Automated Survey for which high-quality light curves, photometry, and proper motions are available. We obtain high-resolution echelle spectra for these objects to determine radial velocities and abundances as part of the Carnegie RR Lyrae Survey. We find that M{sub V,RRc} = 0.59 ± 0.10 at a mean metallicity of [Fe/H] = –1.59. This is to be compared with previous estimates for RRab stars (M{sub V,RRab} = 0.76 ± 0.12) and the only direct measurement of an RRc absolute magnitude (RZ Cephei, M{sub V,RRc} = 0.27 ± 0.17). We find the bulk velocity of the halo relative to the Sun to be (W{sub ?}, W{sub ?}, W{sub z} ) = (12.0, –209.9, 3.0) km s{sup –1} in the radial, rotational, and vertical directions with dispersions (?{sub W{sub ?}},?{sub W{sub ?}},?{sub W{sub z}}) = (150.4, 106.1, 96.0) km s{sup -1}. For the disk, we find (W{sub ?}, W{sub ?}, W{sub z} ) = (13.0, –42.0, –27.3) km s{sup –1} relative to the Sun with dispersions (?{sub W{sub ?}},?{sub W{sub ?}},?{sub W{sub z}}) = (67.7,59.2,54.9) km s{sup -1}. Finally, as a byproduct of our statistical framework, we are able to demonstrate that UCAC2 proper-motion errors are significantly overestimated as verified by UCAC4.

  18. Dark light, rod saturation, and the absolute and incremental sensitivity of mouse cone vision.

    PubMed

    Naarendorp, Frank; Esdaille, Tricia M; Banden, Serenity M; Andrews-Labenski, John; Gross, Owen P; Pugh, Edward N

    2010-09-15

    Visual thresholds of mice for the detection of small, brief targets were measured with a novel behavioral methodology in the dark and in the presence of adapting lights spanning ?8 log(10) units of intensity. To help dissect the contributions of rod and cone pathways, both wild-type mice and mice lacking rod (Gnat1(-/-)) or cone (Gnat2(cpfl3)) function were studied. Overall, the visual sensitivity of mice was found to be remarkably similar to that of the human peripheral retina. Rod absolute threshold corresponded to 12-15 isomerized pigment molecules (R*) in image fields of 800 to 3000 rods. Rod "dark light" (intrinsic retinal noise in darkness) corresponded to that estimated previously from single-cell recordings, 0.012 R* s(-1) rod(-1), indicating that spontaneous thermal isomerizations are responsible. Psychophysical rod saturation was measured for the first time in a nonhuman species and found to be very similar to that of the human rod monochromat. Cone threshold corresponded to ?5 R* cone(-1) in an image field of 280 cones. Cone dark light was equivalent to ?5000 R* s(-1) cone(-1), consistent with primate single-cell data but 100-fold higher than predicted by recent measurements of the rate of thermal isomerization of mouse cone opsins, indicating that nonopsin sources of noise determine cone threshold. The new, fully automated behavioral method is based on the ability of mice to learn to interrupt spontaneous wheel running on the presentation of a visual cue and provides an efficient and highly reliable means of examining visual function in naturally behaving normal and mutant mice. PMID:20844144

  19. Thermal Insulation

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Commercially known as Solimide, Temptronics, Inc.'s thermal insulation has application in such vehicles as aircraft, spacecraft and surface transportation systems (i.e. rapid transit cars, trains, buses, and ships) as acoustical treatment for door, wall, and ceiling panels, as a means of reducing vibrations, and as thermal insulation (also useful in industrial equipment). Product originated from research conducted by Johnson Space Center on advanced flame-resistant materials for minimizing fire hazard in the Shuttle and other flight vehicles.

  20. Absolute configuration of a chiral CHD group via neutron diffraction: confirmation of the absolute stereochemistry of the enzymatic formation of malic acid

    SciTech Connect

    Bau, R.; Brewer, I.; Chiang, M.Y.; Fujita, S.; Hoffman, J.; Watkins, M.I.; Koetzle, T.F.

    1983-09-30

    Neutron diffraction has been used to monitor the absolute stereochemistry of an enzymatic reaction. (-)(2S)malic-3-d acid was prepared by the action of fumarase on fumaric acid in D/sub 2/O. After a large number of cations were screened, it was found that (+)(R)..cap alpha..-phenylethylamine forms the large crystals necessary for a neutron diffraction analysis. The subsequent structure determination showed that (+)(R)..cap alpha..-phenylethylammonium (-)(2S)malate-3-d has an absolute configuration of R at the CHD site. This result confirms the absolute stereochemistry of fumarate-to-malate transformation as catalyzed by the enzyme fumarase.